@phdthesis{Kleineisel2024,
  author    = {Kleineisel, Jonas},
  title     = {Variational networks in magnetic resonance imaging - Application to spiral cardiac MRI and investigations on image quality},
  doi       = {10.25972/OPUS-34737},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347370},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Acceleration is a central aim of clinical and technical research in magnetic resonance imaging (MRI) today, with the potential to increase robustness, accessibility and patient comfort, reduce cost, and enable entirely new kinds of examinations. A key component in this endeavor is image reconstruction, as most modern approaches build on advanced signal and image processing. Here, deep learning (DL)-based methods have recently shown considerable potential, with numerous publications demonstrating benefits for MRI reconstruction. However, these methods often come at the cost of an increased risk for subtle yet critical errors. Therefore, the aim of this thesis is to advance DL-based MRI reconstruction, while ensuring high quality and fidelity with measured data. A network architecture specifically suited for this purpose is the variational network (VN). To investigate the benefits these can bring to non-Cartesian cardiac imaging, the first part presents an application of VNs, which were specifically adapted to the reconstruction of accelerated spiral acquisitions. The proposed method is compared to a segmented exam, a U-Net and a compressed sensing (CS) model using qualitative and quantitative measures. While the U-Net performed poorly, the VN as well as the CS reconstruction showed good output quality. In functional cardiac imaging, the proposed real-time method with VN reconstruction substantially accelerates examinations over the gold-standard, from over 10 to just 1 minute. Clinical parameters agreed on average. Generally in MRI reconstruction, the assessment of image quality is complex, in particular for modern non-linear methods. Therefore, advanced techniques for precise evaluation of quality were subsequently demonstrated. With two distinct methods, resolution and amplification or suppression of noise are quantified locally in each pixel of a reconstruction. Using these, local maps of resolution and noise in parallel imaging (GRAPPA), CS, U-Net and VN reconstructions were determined for MR images of the brain. In the tested images, GRAPPA delivers uniform and ideal resolution, but amplifies noise noticeably. The other methods adapt their behavior to image structure, where different levels of local blurring were observed at edges compared to homogeneous areas, and noise was suppressed except at edges. Overall, VNs were found to combine a number of advantageous properties, including a good trade-off between resolution and noise, fast reconstruction times, and high overall image quality and fidelity of the produced output. Therefore, this network architecture seems highly promising for MRI reconstruction.},
  subject      = {Kernspintomografie},
  language  = {en}
}
@phdthesis{Berberich2024,
  author    = {Berberich, Oliver},
  title     = {Lateral Cartilage Tissue Integration - Evaluation of Bonding Strength and Tissue Integration \(in\) \(vitro\) Utilizing Biomaterials and Adhesives},
  doi       = {10.25972/OPUS-34602},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346028},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Articular cartilage defects represent one of the most challenging clinical problem for orthopedic surgeons and cartilage damage after trauma can result in debilitating joint pain, functional impairment and in the long-term development of osteoarthritis. The lateral cartilage-cartilage integration is crucial for the long-term success and to prevent further tissue degeneration. Tissue adhesives and sealants are becoming increasingly more popular and can be a beneficial approach in fostering tissue integration, particularly in tissues like cartilage where alternative techniques, such as suturing, would instead introduce further damage. However, adhesive materials still require optimization regarding the maximization of adhesion strength on the one hand and long-term tissue integration on the other hand. In vitro models can be a valuable support in the investigation of potential candidates and their functional mechanisms. For the conducted experiments within this work, an in vitro disc/ring model obtained from porcine articular cartilage tissue was established. In addition to qualitative evaluation of regeneration, this model facilitates the implementation of biomechanical tests to quantify cartilage integration strength. Construct harvesting for histology and other evaluation methods could be standardized and is ethically less questionable compared to in vivo testing. The opportunity of cell culture technique application for the in vitro model allowed a better understanding of cartilage integration processes. Tissue bonding requires chemical or physical interaction of the adhesive material and the substrate. Adhesive hydrogels can bind to the defect interface and simultaneously fill the gap of irregularly shaped defect voids. Fibrin gels are derived from the physiological blood-clot formation and are clinically applied for wound closure. Within this work, comparisons of different fibrin glue formulations with the commercial BioGlue® were assessed, which highlighted the need for good biocompatibility when applied on cartilage tissue in order to achieve satisfying long-term integration. Fibrin gel formulations can be adapted with regard to their long-term stability and when applied on cartilage disc/ring constructs improved integrative repair is observable. The kinetic of repairing processes was investigated in fibrin-treated cartilage composites as part of this work. After three days in vitro cultivation, deposited extracellular matrix (ECM) was obvious at the glued interface that increased further over time. Interfacial cell invasion from the surrounding native cartilage was detected from day ten of tissue culture. The ECM formation relies on molecular factors, e.g., as was shown representatively for ascorbic acid, and contributes to increasing integration strengths over time. The experiments performed with fibrin revealed that the treatment with a biocompatible adhesive that allows cartilage neosynthesis favors lateral cartilage integration in the long term. However, fibrin has limited immediate bonding strength, which is disadvantageous for use on articular cartilage that is subject to high mechanical stress. The continuing aim of this thesis was to further develop adhesive mechanisms and new adhesive hydrogels that retain the positive properties of fibrin but have an increased immediate bonding strength. Two different photochemical approaches with the advantage of on-demand bonding were tested. Such treatment potentially eases the application for the professional user. First, an UV light induced crosslinking mechanism was transferred to fibrin glue to provide additional bonding strength. For this, the cartilage surface was functionalized with highly reactive light-sensitive diazirine groups, which allowed additional covalent bonds to the fibrin matrix and thus increased the adhesive strength. However, the disadvantages of this approach were the multi-step bonding reactions, the need for enzymatic pretreatment of the cartilage, expensive reagents, potential UV-light damage, and potential toxicity hazards. Due to the mentioned disadvantages, no further experiments, including long-term culture, were carried out. A second photosensitive approach focused on blue light induced crosslinking of fibrinogen (RuFib) via a photoinitiator molecule instead of using thrombin as a crosslinking mediator like in normal fibrin glue. The used ruthenium complex allowed inter- and intramolecular dityrosine binding of fibrinogen molecules. The advantage of this method is a one-step curing of fibrinogen via visible light that further achieved higher adhesive strengths than fibrin. In contrast to diazirine functionalization of cartilage, the ruthenium complex is of less toxicological concern. However, after in vitro cultivation of the disc/ring constructs, there was a decrease in integration strength. Compared to fibrin, a reduced cartilage synthesis was observed at the defect. It is also disadvantageous that a direct adjustment of the adhesive can only be made via protein concentration, since fibrinogen is a natural protein that has a fixed number of tyrosine binding sites without chemical modification. An additional cartilage adhesive was developed that is based on a mussel-inspired adhesive mechanism in which reactivity to a variety of substrates is enabled via free DOPA amino acids. DOPA-based adhesion is known to function in moist environments, a major advantage for application on water-rich cartilage tissue surrounded by synovial liquid. Reactive DOPA groups were synthetically attached to a polymer, here POx, to allow easy chemical modifiability, e.g. insertion of hydrolyzable ester motifs for tunable degradation. The possibility of preparing an adhesive hybrid hydrogel of POx in combination with fibrinogen led to good cell compatibility as was similarly observed with fibrin, but with increased immediate adhesive strength. Degradation could be adjusted by the amount of ester linkages on the POx and a direct influence of degradation rates on the development of integration in the in vitro model could be shown. Hydrogels are well suited to fill defect gaps and immediate integration can be achieved via adhesive properties. The results obtained show that for the success of long-term integration, a good ability of the adhesive to take up synthesized ECM components and cells to enable regeneration is required. The degradation kinetics of the adhesive must match the remodeling process to avoid intermediate loss of integration power and to allow long-term firm adhesion to the native tissue. Hydrogels are not only important as adhesives for smaller lesions, but also for filling large defect volumes and populating them with cells to produce tissue engineered cartilage. Many different hydrogel types suitable for cartilage synthesis are reported in the literature. A long-term stable fibrin formulation was tested in this work not only as an adhesive but also as a bulk hydrogel construct. Agarose is also a material widely used in cartilage tissue engineering that has shown good cartilage neosynthesis and was included in integration assessment. In addition, a synthetic hyaluronic acid-based hydrogel (HA SH/P(AGE/G)) was used. The disc/ring construct was adapted for such experiments and the inner lumen of the cartilage ring was filled with the respective hydrogel. In contrast to agarose, fibrin and HA-SH/P(AGE/G) gels have a crosslink mechanism that led to immediate bonding upon contact with cartilage during curing. The enhanced cartilage neosynthesis in agarose compared to the other hydrogel types resulted in improved integration during in vitro culture. This shows that for the long-term success of a treatment, remodeling of the hydrogel into functional cartilage tissue is a very high priority. In order to successfully treat larger cartilage defects with hydrogels, new materials with these properties in combination with chemical modifiability and a direct adhesion mechanism are one of the most promising approaches.},
  subject      = {Knorpel},
  language  = {en}
}
@phdthesis{Shaikh2024,
  author    = {Shaikh, Muhammad Haroon},
  title     = {Nicht-h{\"a}matopoetische lymphoide Stromazellen aktivieren alloreaktive CD4\(^+\) T-Zellen in der Initiierung der akuten Graft-versus-Host Disease},
  doi       = {10.25972/OPUS-25201},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252015},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {In der Initiationsphase der akuten Graft-versus-Host Erkrankung (GvHD) werden CD4+ T-Zellen in den lymphatischen Organen durch h{\"a}matopoietische Antigen-pr{\"a}sentierende Zellen aktiviert. Im Gegensatz dazu, werden in der Effektorphase CD4+ T-Zellen von nicht-h{\"a}matopoetischen Zellen im D{\"u}nndarm aktiviert. Wir stellten die Hypothese auf, dass alloreaktive CD4+ T-Zellen nach allogener h{\"a}matopoetischer Zelltransplantation, welche in der Initiationsphase der aGvHD vorwiegend in die sekund{\"a}ren lymphatischen Organe migrieren, dort durch nicht-h{\"a}matopoetische Lymphknoten-Stromazellen {\"u}ber die Erkennung von MHC-Klasse II aktiviert werden. Um diese Hypothese zu testen, setzten wir ein von allogenen CD4+ T-Zellen-abh{\"a}ngiges MHC Major Mismatch aGvHD Mausmodell ein, um diese Zusammenh{\"a}nge n{\"a}her zu erforschen. Mittels Biolumineszenz-Bildgebung und dreidimensionale Lichtblattmikroskopie und Durchflusszytometrie-Analysen von fr{\"u}heren Zeitpunkten nach einer alloHCT bzw. im Anfangsstadium der aGvHD konnten wir zeigen, dass allogene T-Zellen exklusiv in die Milz, Lymphknoten und die Peyerschen Plaques migrieren und nicht in die intestinale Lamina propria. Indem wir transgene Mauslinien verwendeten, die keine oder eine nur partielle komplette h{\"a}matopoietische Antigenpr{\"a}sentation aufwiesen, konnten wir eine sehr fr{\"u}h auf die alloHCT folgende allogene CD4+ T-Zellaktivierung in den lymphoiden Organen von MHCIIΔCD11c and MHCIIΔ Knochenmark-Chim{\"a}ren nachweisen. Aufgrund des, bei den MHCIIΔ Knochenmarks-Chim{\"a}ren auftretenden Versagens der negativen Thymusselektion und die daraus resultierende autoreaktive Immunreaktionen nach einer syngenen HCST stellte sich heraus, dass dies ein ungeeignetes Modell f{\"u}r die Untersuchung der Pr{\"a}sentation nicht-h{\"a}matopoetischer Antigene bei GvHD ist. Um diese Herausforderung zu bew{\"a}ltigen, generierten wir MHCIIΔVav1 M{\"a}use bei denen die MHC-Klasse-II-Expression auf allen h{\"a}matopoetischen Zellen fehlt. MHCIIΔVav1 M{\"a}use entwickelten eine aGvHD, wobei die Lymphknoten-Stromazellen dieser Tiere allogene CD4+ T-Zellen in gemischten Lymphozytenreaktionen aktivieren konnten. Ebenso konnten mesenteriale Lymphknoten von CD11c.DTR-M{\"a}usen, die zuvor in eine MHCIIΔ Maus transplantiert wurden, CD4+ T-Zellen in vivo aktivieren, wodurch die Lymphknoten-Stromazellen eindeutig als nicht-h{\"a}matopoetische Antigen-pr{\"a}sentierende Zellen der lymphoiden Organe nachgewiesen werden konnten. {\"U}ber das Cre/loxP-System konnten wir Knockout-M{\"a}use mit fehlender MHCII-Expression in Subpopulationen von Lymphknoten-Stromazellen generieren und verwendeten dann Einzelzell-RNA-Sequenzierung. Hier w{\"a}hlten wir Ccl19 und VE-Cadherin aus, um unsere Analyse spezifisch auf die fibroblastischen retikul{\"a}ren Zellen bzw. Endothelzellen der Lymphknoten zu konzentrieren. Bei MHCIIΔCcl19 M{\"a}usen war die Aktivierung alloreaktiver CD4+ T-Zellen in der Initiationsphase der aGvHD m{\"a}ßig reduziert, w{\"a}hrend das Fehlen von MHCII auf den fibroblastischen retikul{\"a}ren Zellen zu einer Hyperaktivierung allogener CD4+ T-Zellen f{\"u}hrte, was wiederum eine schlechtere {\"U}berlebensrate der M{\"a}use zur Folge hatte. Dieser Ph{\"a}notyp wurde durch regulatorische T-Zellen moduliert, die in der Lage waren, H2-Ab1fl M{\"a}use von den Folgen von GvHD zu retten, jedoch nicht die MHCIIΔCcl19. Ein Knock-out von MHCII auf Endothelzellen von MHCIIΔVE-Cadherin M{\"a}usen, f{\"u}hrte in der Initiationsphase der GvHD nur zu einer m{\"a}ßig reduzierten Aktivierung von CD4+ T-Zellen. Umgekehrt zeigten MHCIIΔVE-Cadherin M{\"a}use im Langzeit{\"u}berleben jedoch einen protektiven Ph{\"a}notyp verglichen mit wurfgeschwister H2-Ab1fl M{\"a}usen. Um die Bedeutung der MHCII-Antigenpr{\"a}sentation der Endothelzellen zu untersuchen, generierten wir außerdem MHCIIΔVE-CadherinΔVav1 M{\"a}use, bei welchen eine Antigenpr{\"a}sentation, weder im endothelialen noch im h{\"a}matopoetischen Kompartiment m{\"o}glich war. Lymphknoten-Stromazellen von MHCIIΔVE-CadherinΔVav1 M{\"a}usen waren nicht in der Lage, alloreaktive CD4+ T-Zellen in einer gemischten Lymphozytenreaktion zu aktivieren. Insgesamt konnten wir zum ersten Mal beweisen, dass die MHC-Klassse II auf den Lymphknoten-Stromazellen eine entscheidende Rolle bei der Modulation allogener CD4+ T-Zellen in der Initiations- und schließlich in der Effektorphase der Graft-versus-Host-Disease spielt.},
  subject      = {Transplantat-Wirt-Reaktion},
  language  = {en}
}
@phdthesis{SchukraftgebScheffler2024,
  author    = {Schukraft [geb. Scheffler], Nina},
  title     = {Integrated defensive states and their neuronal correlates in the Periaqueductal Gray},
  doi       = {10.25972/OPUS-34745},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347458},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {In the face of threat, animals react with a defensive reaction to avoid or reduce harm. This defensive reaction encompasses apart from behavioral changes also physiological, analgetic, and endocrine adaptations. Nonetheless, most animal studies on fear and anxiety are based on behavioral observations only, disregarding other aspects of the defensive reaction, or integrating their inter-related dynamics only insufficiently. The first part of this thesis aimed in characterizing patterned associations of behavioral and physiological responses, termed integrated defensive states. Analyzing cardiac and behavioral responses in mice undergoing multiple fear and anxiety paradigms revealed a complex and dynamic interaction of those readouts on both, short and long timescales. Microstates, stereotypical combinations of i.e. freezing and decelerating heart rates, are short-lasting and were, in turn, shown to be influenced by slow acting macrostate changes. One of those higher order macrostates, called `rigidity`, was defined as a latent process that constrains the range of momentary displayed heart rate values. Furthermore, integrated defensive states were found to be highly dependent on the cue and the context the animals are confronted with. Importantly, same behavioral observations, i.e. freezing, were associated with distinct cardiac responses, highlighting the importance of multivariate analysis of integrated defensive states. Defensive states are orchestrated by the brain, which has evolved evolutionary conserved survival circuits. A central brain area of these circuits is the periaqueductal gray (PAG) in the midbrain. It plays a pivotal role in mediating defensive states, as it receives signals about external and internal information from multiple brain regions and sends information to both, higher order brain areas as well as to the brainstem ultimately causing the execution of threat responses. In the second part of this thesis, different neuronal circuit elements in the PAG were optically manipulated in order to gain mechanistic insight into the defense network in the brain underlying the previously delineated cardio-behavioral defensive states. Optical activation of glutamatergic PAG neurons evoked heterogeneous, light-intensity dependent responses. However, a further molecular restriction of the glutamatergic neuronal population targeting only Chx10+ neurons, led to a cardio-behavioral state that resembled spontaneous freezing-bradycardia bouts. In summary, this thesis presents a multivariate description of defensive states, which includes the complex interaction of cardiac and behavioral responses on different timescales and, furthermore, functionally dissects different excitatory and inhibitory PAG circuit elements mediating these defensive states.},
  subject      = {Perianova, Irina},
  language  = {en}
}
@phdthesis{Janz2024,
  author    = {Janz, Anna},
  title     = {Human induced pluripotent stem cells (iPSCs) in inherited cardiomyopathies: Generation and characterization of an iPSC-derived cardiomyocyte model system of dilated cardiomyopathy with ataxia (DCMA)},
  doi       = {10.25972/OPUS-24096},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-240966},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The emergence of human induced pluripotent stem cells (iPSCs) and the rise of the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) gene editing technology innovated the research platform for scientists based on living human pluripotent cells. The revolutionary combination of both Nobel Prize-honored techniques enables direct disease modeling especially for research focused on genetic diseases. To allow the study on mutation-associated pathomechanisms, we established robust human in vitro systems of three inherited cardiomyopathies: arrhythmogenic cardiomyopathy (ACM), dilated cardiomyopathy with juvenile cataract (DCMJC) and dilated cardiomyopathy with ataxia (DCMA). Sendai virus vectors encoding OCT3/4, SOX2, KLF4, and c-MYC were used to reprogram human healthy control or mutation-bearing dermal fibroblasts from patients to an embryonic state thereby allowing the robust and efficient generation of in total five transgene-free iPSC lines. The nucleofection-mediated CRISPR/Cas9 plasmid delivery in healthy control iPSCs enabled precise and efficient genome editing by mutating the respective disease genes to create isogenic mutant control iPSCs. Here, a PKP2 knock-out and a DSG2 knock-out iPSC line were established to serve as a model of ACM. Moreover, a DNAJC19 C-terminal truncated variant (DNAJC19tv) was established to mimic a splice acceptor site mutation in DNAJC19 of two patients with the potential of recapitulating DCMA-associated phenotypes. In total eight self-generated iPSC lines were assessed matching internationally defined quality control criteria. The cells retained their ability to differentiate into cells of all three germ layers in vitro and maintained a stable karyotype. All iPSC lines exhibited a typical stem cell-like morphology as well as expression of characteristic pluripotency markers with high population purities, thus validating the further usage of all iPSC lines in in vitro systems of ACM, DCMA and DCMJC. Furthermore, cardiac-specific disease mechanisms underlying DCMA were investigated using in vitro generated iPSC-derived cardiomyocytes (iPSC-CMs). DCMA is an autosomal recessive disorder characterized by life threatening early onset cardiomyopathy associated with a metabolic syndrome. Causal mutations were identified in the DNAJC19 gene encoding an inner mitochondrial membrane (IMM) protein with a presumed function in mitochondrial biogenesis and cardiolipin (CL) remodeling. In total, two DCMA patient-derived iPSC lines (DCMAP1, DCMAP2) of siblings with discordant cardiac phenotypes, a third isogenic mutant control iPSC line (DNAJC19tv) as well as two control lines (NC6M and NC47F) were directed towards the cardiovascular lineage upon response to extracellular specification cues. The monolayer cardiac differentiation approach was successfully adapted for all five iPSC lines and optimized towards ventricular subtype identity, higher population purities and enhanced maturity states to fulfill all DCMA-specific requirements prior to phenotypic investigations. To provide a solid basis for the study of DCMA, the combination of lactate-based metabolic enrichment, magnetic-activated cell sorting, mattress-based cultivation and prolonged cultivation time was performed in an approach-dependent manner. The application of the designated strategies was sufficient to ensure adult-like characteristics, which included at least 60-day-old iPSC-CMs. Therefore, the novel human DCMA platform was established to enable the study of the pathogenesis underlying DCMA with respect to structural, morphological and functional changes. The disease-associated protein, DNAJC19, is constituent of the TIM23 import machinery and can directly interact with PHB2, a component of the membrane bound hetero-oligomeric prohibitin ring complexes that are crucial for phospholipid and protein clustering in the IMM. DNAJC19 mutations were predicted to cause a loss of the DnaJ interaction domain, which was confirmed by loss of full-length DNAJC19 protein in all mutant cell lines. The subcellular investigation of DNAJC19 demonstrated a nuclear restriction in mutant iPSC-CMs. The loss of DNAJC19 co-localization with mitochondrial structures was accompanied by enhanced fragmentation, an overall reduction of mitochondrial mass and smaller cardiomyocytes. Ultrastructural analysis yielded decreased mitochondria sizes and abnormal cristae providing a link to defects in mitochondrial biogenesis and CL remodeling. Preliminary data on CL profiles revealed longer acyl chains and a more unsaturated acyl chain composition highlighting abnormities in the phospholipid maturation in DCMA. However, the assessment of mitochondrial function in iPSCs and dermal fibroblasts revealed an overall higher oxygen consumption that was even more enhanced in iPSC-CMs when comparing all three mutants to healthy controls. Excess oxygen consumption rates indicated a higher electron transport chain (ETC) activity to meet cellular ATP demands that probably result from proton leakage or the decoupling of the ETC complexes provoked by abnormal CL embedding in the IMM. Moreover, in particular iPSC-CMs presented increased extracellular acidification rates that indicated a shift towards the utilization of other substrates than fatty acids, such as glucose, pyruvate or glutamine. The examination of metabolic features via double radioactive tracer uptakes (18F-FDG, 125I-BMIPP) displayed significantly decreased fatty acid uptake in all mutants that was accompanied by increased glucose uptake in one patient cell line only, underlining a highly dynamic preference of substrates between mutant iPSC-CMs. To connect molecular changes directly to physiological processes, insights on calcium kinetics, contractility and arrhythmic potential were assessed and unraveled significantly increased beating frequencies, elevated diastolic calcium concentrations and a shared trend towards reduced cell shortenings in all mutant cell lines basally and upon isoproterenol stimulation. Extended speed of recovery was seen in all mutant iPSC-CMs but most striking in one patient-derived iPSC-CM model, that additionally showed significantly prolonged relaxation times. The investigations of calcium transient shapes pointed towards enhanced arrhythmic features in mutant cells comprised by both the occurrence of DADs/EADs and fibrillation-like events with discordant preferences. Taken together, new insights into a novel in vitro model system of DCMA were gained to study a genetically determined cardiomyopathy in a patient-specific manner upon incorporation of an isogenic mutant control. Based on our results, we suggest that loss of full-length DNAJC19 impedes PHB2-complex stabilization within the IMM, thus hindering PHB-rings from building IMM-specific phospholipid clusters. These clusters are essential to enable normal CL remodeling during cristae morphogenesis. Disturbed cristae and mitochondrial fragmentation were observed and refer to an essential role of DNAJC19 in mitochondrial morphogenesis and biogenesis. Alterations in mitochondrial morphology are generally linked to reduced ATP yields and aberrant reactive oxygen species production thereby having fundamental downstream effects on the cardiomyocytes` functionality. DCMA-associated cellular dysfunctions were in particular manifested in excess oxygen consumption, altered substrate utilization and abnormal calcium kinetics. The summarized data highlight the usage of human iPSC-derived CMs as a powerful tool to recapitulate DCMA-associated phenotypes that offers an unique potential to identify therapeutic strategies in order to reverse the pathological process and to pave the way towards clinical applications for a personalized therapy of DCMA in the future.},
  subject      = {Induzierte pluripotente Stammzelle},
  language  = {en}
}
@phdthesis{Cellini2024,
  author    = {Cellini, Antonella},
  title     = {Die Rolle der Na\(^+\)/K\(^+\)-ATPase in der Herzinsuffizienz},
  doi       = {10.25972/OPUS-29789},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297894},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Die Na+ /K+ -ATPase (NKA) ist maßgeblich an der Regulation der kardialen Na+ -Hom{\"o}ostase beteilligt. Im Myokard werden haupts{\"a}chlich zwei Isoformen exprimiert: die α1 (NKA-α1) und die α2-Isoform (NKA-α2). Diese beiden Isoformen unterscheiden sich sowohl in ihrer Lokalisation als auch in ihrer zellul{\"a}ren Funktion. So ist die NKA-α1 recht homogen entlang des Sarkolemms zu finden und ist verantwortlich f{\"u}r die Regulation der globalen intrazellul{\"a}ren Na+ -Konzentration ([Na+ ]i). Die NKA-α2 hingegen konzentriert sich haupts{\"a}chlich in den T-Tubuli und beeinflusst {\"u}ber Ver{\"a}nderung der lokalen [Na+ ]i die Ca2+ -Transienten und die Kontraktilit{\"a}t. Im Rahmen einer Herzinsuffizienz wurde eine verminderte Expression und Aktivit{\"a}t der NKA beobachtet. Gleichzeitig werden Inhibitoren der NKA, sogenannte Digitalisglykoside, in fortgeschrittenen Herzinsuffizienz-Stadien eingesetzt. Die Studienlage {\"u}ber den Einsatz dieser Therapeutika ist recht uneinheitlich und reicht von einer verringerten Hospitalisierung bis hin zu einer erh{\"o}hten Mortalit{\"a}t. Ziel dieser Arbeit war es die Folgen einer NKA-α2 Aktivierung w{\"a}hrend einer Herzinsuffizienz mit Hilfe eines murinen {\"U}berexpressionsmodells zu analysieren. 11-Wochen alte M{\"a}use mit einer kardialen NKA-α2 {\"U}berexpression (NKA-α2) und Wildtyp (WT) Versuchstiere wurden einem 8-w{\"o}chigen Myokardinfarkt (MI) unterzogen. NKA-α2 Versuchstiere waren vor einem pathologischem Remodeling und einer kardialen Dysfunktion gesch{\"u}tzt. NKA-α2 Kardiomyozyten zeigten eine erh{\"o}hte Na+ /Ca2+ -Austauscher (NCX) Aktivit{\"a}t, die zu niedrigeren diastolischen und systolischen Ca2+ -Spiegeln f{\"u}hrte und einer Ca2+ -Desensitisierung der Myofibrillen entgegenwirkte. WT Versuchstiere zeigten nach chronischem MI eine sarkoplasmatische Ca2+ -Akkumulation, die in NKA-α2 Kardiomyozyten ausblieb. Gleichzeitig konnte in der NKA-α2 MI Kohorte im Vergleich zu den WT MI Versuchstieren eine erh{\"o}hte Expression von β1-adrenergen Rezeptoren (β1AR) beobachtet werden, die eine verbesserte Ansprechbarkeit gegen{\"u}ber β-adrenergen Stimuli bewirkte. Zudem konnte in unbehandelten Versuchstieren eine Interaktion zwischen NKA-α2 und dem β1AR nachgewiesen werden, welche in der WT Kohorte gr{\"o}ßer ausfiel als in der NKA-α2 Versuchsgruppe. Gleichzeitig zeigten unbehandelte NKA-α2 Kardiomyozyten eine erh{\"o}hte Sensitivit{\"a}t gegen{\"u}ber β-adrenerger Stimulation auf, welche nicht mit einer erh{\"o}hten Arrhythmie-Neigung oder vermehrten Bildung reaktiver Sauerstoffspezies einherging. Diese Untersuchungen zeigen, dass eine NKA-α2 {\"U}berexpression vor pathologischem Remodeling und einer kardialen Funktionbeeintr{\"a}chtigung sch{\"u}tzt, indem eine systolische, diastolische und sarkoplasmatische Ca2+ -Akkumulation verhindert wird. Gleichzeitig wird die β1AR Expression stabilisert, wodurch es zu einer verminderten neurohumoralen Aktivierung und einer Durchbrechung des Circulus vitiosus kommen k{\"o}nnte. Insgesamt scheint eine Aktivierung der NKA-α2 durchaus ein vielversprechendes Target in der Herzinsuffizienz Therapie darzustellen. Therapie darzustellen.},
  subject      = {Herzinsuffizienz},
  language  = {de}
}
@phdthesis{Massih2024,
  author    = {Massih, Bita},
  title     = {Human stem cell-based models to analyze the pathophysiology of motor neuron diseases},
  publisher = {Frontiers in Cell and Developmental Biology},
  doi       = {10.25972/OPUS-34637},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346374},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Motor neuron diseases (MNDs) encompass a variety of clinically and genetically heterogeneous disorders, which lead to the degeneration of motor neurons (MNs) and impaired motor functions. MNs coordinate and control movement by transmitting their signal to a target muscle cell. The synaptic endings of the MN axon and the contact site of the muscle cell thereby form the presynaptic and postsynaptic structures of the neuromuscular junction (NMJ). In MNDs, synaptic dysfunction and synapse elimination precede MN loss suggesting that the NMJ is an early target in the pathophysiological cascade leading to MN death. In this study, we established new experimental strategies to analyze human MNDs by patient derived induced pluripotent stem cells (iPSCs) and investigated pathophysiological mechanisms in two different MNDs. To study human MNDs, specialized cell culture systems that enable the connection of MNs to their target muscle cells are required to allow the formation of NMJs. In the first part of this study, we established and validated a human neuromuscular co-culture system consisting of iPSC derived MNs and 3D skeletal muscle tissue derived from myoblasts. We generated 3D muscle tissue by culturing primary myoblasts in a defined extracellular matrix in self-microfabricated silicone dishes that support the 3D tissue formation. Subsequently, iPSCs from healthy donors and iPSCs from patients with the progressive MND Amyotrophic Lateral Sclerosis (ALS) were differentiated into MNs and used for 3D neuromuscular co-cultures. Using a combination of immunohistochemistry, calcium imaging, and pharmacological stimulations, we characterized and confirmed the functionality of the 3D muscle tissue and the 3D neuromuscular co-cultures. Finally, we applied this system as an in vitro model to study the pathophysiology of ALS and found a decrease in neuromuscular coupling, muscle contraction, and axonal outgrowth in co-cultures with MNs harboring ALS-linked superoxide dismutase 1 (SOD1) mutation. In summary, this co-culture system presents a human model for MNDs that can recapitulate aspects of ALS pathophysiology. In the second part of this study, we identified an impaired unconventional protein secretion (UPS) of Sod1 as pathological mechanisms in Pleckstrin homology domain-containing family G member 5 (Plekhg5)-associated MND. Sod1 is a leaderless cytosolic protein which is secreted in an autophagy-dependent manner. We found that Plekhg5 depletion in primary MNs and NSC34 cells leads to an impaired secretion of wildtype Sod1, indicating that Plekhg5 drives the UPS of Sod1 in vitro. By interfering with different steps during the biogenesis of autophagosomes, we could show that Plekhg5-regulated Sod1 secretion is determined by autophagy. To analyze our findings in a clinically more relevant model we utilized human iPSC MNs from healthy donors and ALS patients with SOD1 mutations. We observed reduced SOD1 secretion in ALS MNs which coincides with reduced protein expression of PLEKHG5 compared to healthy and isogenic control MNs. To confirm this correlation, we depleted PLEKHG5 in control MNs and found reduced extracellular SOD1 levels, implying that SOD1 secretion depends on PLEKHG5. In summary, we found that Plekh5 regulates the UPS of Sod1 in mouse and human MNs and that Sod1 secretion occurs in an autophagy dependent manner. Our data shows an unreported mechanistic link between two MND-associated proteins.},
  subject      = {Tissue Engineering},
  language  = {en}
}
@phdthesis{Zimniak2024,
  author    = {Zimniak, Melissa Maria},
  title     = {Der Serotonin-Wiederaufnahmehemmer Fluoxetin inhibiert die SARS-CoV-2-Replikation},
  doi       = {10.25972/OPUS-34719},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347190},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Die COVID-19 Pandemie ist die bisher verheerendste Pandemie des 21. Jahrhunderts. Durch die Einf{\"u}hrung neuer mRNA-basierter Impfstoffe sowie der hohen Rate nat{\"u}rlicher Infektionen konnte die weltweite SARS-CoV-2-Immunit{\"a}t gesteigert werden. Trotz aller Erfolge zur Eind{\"a}mmung der Pandemie kann eine Infektion auch heute noch zu schweren Verl{\"a}ufen und Tod f{\"u}hren. Eine ad{\"a}quate COVID-19-Therapie ist folglich auf potente Virostatika angewiesen. Eine durch Umgehung zeitaufw{\"a}ndiger klinischer Studien schnell verf{\"u}gbare Alternative zu neu entwickelten Arzneimitteln ist die Anwendung etablierter Medikamente. Wir isolierten und charakterisierten ein von einem Patienten stammendes SARS-CoV-2-Virus. Dieses Virusisolat wurde bisher in elf Publikationen verwendet. Mittels quantitativer Echtzeit-Polymerasekettenreaktion untersuchten wir eine Substanzbibliothek mit mehr als 300 neuen und bereits zugelassenen Wirkstoffen auf ihre Wirksamkeit gegen SARS-CoV-2. Dabei konnten wir zeigen, dass der selektive Serotonin-Wiederaufnahmehemmer Fluoxetin die SARS-CoV-2-Replikation ab einer Dosis von 0,8 μg/ml signifikant inhibiert, einer bei der Behandlung von Depressionen h{\"a}ufig angewandten Dosierung. Der EC50-Wert lag bei 387 ng/ml. Die Behandlung mit Fluoxetin resultierte in einer reduzierten Zahl an Virusprotein-produzierenden Zellen, was darauf hindeutet, dass es die virale Reinfektion und/oder Proteinexpression inhibiert. Fluoxetin ist ein racemisches Gemisch, wobei das (S)-Enantiomer der potentere Serotonin-Wiederaufnahmehemmer ist. Wir konnten zeigen, dass beide Enantiomere einen vergleichbaren antiviralen Effekt gegen SARS-CoV-2 aufweisen, wodurch das (R)-Enantiomer bei virologischer Indikation gegebenenfalls pr{\"a}feriert werden sollte. Fluoxetin hat keinen Einfluss auf die Replikation des Tollwut-Virus und des Humanen Respiratorischen Synzytial-Virus, was auf eine Virusspezifit{\"a}t hindeutet. Weitere aus der Bibliothek stammende signifikante Inhibitoren der SARS-CoV-2-Replikation sind die am Institut f{\"u}r Organische Chemie W{\"u}rzburg entwickelten Substanzen AKS 232 und AKS 128. Neben der medikament{\"o}sen Therapie ist die akkurate Bestimmung neutralisierender Antik{\"o}rper gegen SARS-CoV-2 zur Quantifizierung des bestehenden (Re-) Infektionsschutzes sowie zur Planung zuk{\"u}nftiger Impfstrategien von großer Bedeutung. Im Rahmen dieser Arbeit entwickelten wir unter Verwendung der quantitativen Echtzeit-Polymerasekettenreaktion erfolgreich ein zuverl{\"a}ssiges Testverfahren zur Detektion neutralisierender anti-SARS-CoV-2 Antik{\"o}rper.},
  subject      = {Fluoxetin},
  language  = {de}
}
@phdthesis{Koch2024,
  author    = {Koch, Thorsten Manfred},
  title     = {Wirt - Pathogen Interaktion bei Hornhautinfektionen durch \(Fusarium\) spp.},
  doi       = {10.25972/OPUS-34777},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347774},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Fusarium (F.)-Infektionen des Auges zeigen oft einen schwerwiegenden Verlauf und sind am h{\"a}ufigsten mit Spezies des Fusarium solani species complex assoziiert. Dabei sind das Tragen von weichen Kontaktlinsen sowie Traumata die wichtigsten pr{\"a}disponierenden Faktoren. Vorangegangene Untersuchungen des Nationalen Referenzzentrums f{\"u}r invasive Pilzinfektionen hatten ergeben, dass Infektionen durch F. petroliphilum mit der Nutzung von Kontaktlinsen, Infektionen durch F. falciforme jedoch {\"u}berwiegend traumaassoziiert uns vor allem aus tropischen und subtropischen L{\"a}ndern bekannt sind. Das Ziel dieser Arbeit war es daher zu untersuchen, ob F. falcifomre und F. petroliphilum physiologische Merkmale aufweisen, die f{\"u}r die Unterschiede in den Risikofaktoren f{\"u}r Keratitiden durch die beiden Arten verantwortlich sein k{\"o}nnten.},
  subject      = {Fusarium},
  language  = {de}
}
@phdthesis{Pekarek2024,
  author    = {Pek{\´a}rek, Luk{\´a}š},
  title     = {Single-Molecule Approaches To Study Frameshifting Mechanisms},
  doi       = {10.25972/OPUS-34611},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346112},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The RNAs of many viruses contain a frameshift stimulatory element (FSE) that grants access to an alternate reading frame via -1 programmed ribosomal frameshifting (PRF). This -1PRF is essential for effective viral replication. The -1PRF efficiency relies on the presence of conserved RNA elements within the FSE, such as a slippery sequence, spacer, and a downstream secondary structure - often a hairpin or a pseudoknot. The PRF efficiency is also affected by trans-acting factors such as proteins, miRNAs and metabolites. The interactions of these factors with the RNA and the translation machinery have not yet been completely understood. Traditional ensemble methods used previously to study these events focus on the whole population of molecular species. This results in innate averaging of the molecular behavior and a loss of heterogeneity information. Here, we first established the experimental workflow to study the RNA structures and the effect of potential trans-acting factors using single-molecule force spectroscopy technique, optical tweezers. Additionally, to streamline the data analysis, we developed an algorithm for automatized data processing. Next, we harnessed this knowledge to study viral RNA elements responsible for stimulation of PRF and how the presence of trans-acting factors affects the RNA behavior. We further complemented these single-molecule structural data with ensemble functional assays to gain a complex view on the dynamics behind the programmed ribosomal frameshifting. Specifically, two different viral RNA elements have been studied in the presented work. First, the dynamics of SARS-CoV-2 FSE and the role of extended sequences have been explored. Then, the mode of action of the host-encoded trans-acting factor ZAP-S inhibition of SARS-CoV-2 PRF has been examined. Finally, the mechanism of the trans-acting viral factor induced PRF in Encephalomyocarditis virus (EMCV) has been uncovered.},
  language  = {en}
}
@phdthesis{ZimmermannneePapp2024,
  author    = {Zimmermann [n{\´e}e Papp], Lena},
  title     = {Platelets as modulators of blood-brain barrier disruption and inflammation in the pathophysiology of ischemic stroke},
  doi       = {10.25972/OPUS-30285},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302850},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Ischemia-reperfusion injury (I/R injury) is a common complication in ischemic stroke (IS) treatment, which is characterized by a paradoxical perpetuation of tissue damage despite the successful re-establishment of vascular perfusion. This phenomenon is known to be facilitated by the detrimental interplay of platelets and inflammatory cells at the vascular interface. However, the spatio-temporal and molecular mechanisms underlying these cellular interactions and their contribution to infarct progression are still incompletely understood. Therefore, this study intended to clarify the temporal mechanisms of infarct growth after cerebral vessel recanalization. The data presented here could show that infarct progression is driven by early blood-brain-barrier perturbation and is independent of secondary thrombus formation. Since previous studies unravelled the secretion of platelet granules as a molecular mechanism of how platelets contribute to I/R injury, special emphasis was placed on the role of platelet granule secretion in the process of barrier dysfunction. By combining an in vitro approach with a murine IS model, it could be shown that platelet α-granules exerted endothelial-damaging properties, whereas their absence (NBEAL2-deficiency) translated into improved microvascular integrity. Hence, targeting platelet α-granules might serve as a novel treatment option to reduce vascular integrity loss and diminish infarct growth despite recanalization. Recent evidence revealed that pathomechanisms underlying I/R injury are already instrumental during large vessel occlusion. This indicates that penumbral tissue loss under occlusion and I/R injury during reperfusion share an intertwined relationship. In accordance with this notion, human observational data disclosed the presence of a neutrophil dominated immune response and local platelet activation and secretion, by the detection of the main components of platelet α-granules, within the secluded vasculature of IS patients. These initial observations of immune cells and platelets could be further expanded within this thesis by flow cytometric analysis of local ischemic blood samples. Phenotyping of immune cells disclosed a yet unknown shift in the lymphocyte population towards CD4+ T cells and additionally corroborated the concept of an immediate intravascular immune response that is dominated by granulocytes. Furthermore, this thesis provides first-time evidence for the increased appearance of platelet-leukocyte-aggregates within the secluded human vasculature. Thus, interfering with immune cells and/or platelets already under occlusion might serve as a potential strategy to diminish infarct expansion and ameliorate clinical outcome after IS.},
  subject      = {Schlaganfall},
  language  = {en}
}
@phdthesis{Daeullary2024,
  author    = {D{\"a}ullary, Thomas},
  title     = {Establishment of an infection model of the human intestinal epithelium to study host and pathogen determinants during the \(Salmonella\) Typhimurium infection process},
  doi       = {10.25972/OPUS-31154},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311548},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {According to the WHO, foodborne derived enteric infections are a global disease burden and often manifest in diseases that can potentially reach life threatening levels, especially in developing countries. These diseases are caused by a variety of enteric pathogens and affect the gastrointestinal tract, from the gastric to the intestinal to the rectal tissue. Although the complex mucosal structure of these organs is usually well prepared to defend the body against harmful agents, specialised pathogens such as Salmonella enterica can overcome the intestinal defence mechanism. After ingestion, Salmonella are capable of colonising the gut and establishing their proliferative niche, thereby leading to inflammatory processes and tissue damage of the host epithelium. In order to understand these processes, the scientific community in the last decades mostly used cell line based in vitro approaches or in vivo animal studies. Although these approaches provide fundamental insights into the interactions between bacteria and host cells, they have limited applicability to human pathology. Therefore, tissue engineered primary based approaches are important for modern infection research. They exhibit the human complexity better than traditional cell lines and can mimic human-obligate processes in contrast to animal studies. Therefore, in this study a tissue engineered human primary model of the small intestinal epithelium was established for the application of enteric infection research with the exemplary pathogen Salmonella Typhimurium. To this purpose, adult stem cell derived intestinal organoids were used as a primary human cell source to generate monolayers on biological or synthetic scaffolds in a Transwell®-like setting. These tissue models of the intestinal epithelium were examined for their comparability to the native tissue in terms of morphology, morphometry and barrier function. Further, the gene expression profiles of organotypical mucins, tight junction-associated proteins and claudins were investigated. Overall, the biological scaffold-based tissue models showed higher similarity to the native tissue - among others in morphometry and polarisation. Therefore, these models were further characterised on cellular and structural level. Ultrastructural analysis demonstrated the establishment of characteristic microvilli and tight-junction connections between individual epithelial cells. Furthermore, the expression pattern of typical intestinal epithelial protein was addressed and showed in vivo-like localisation. Interested in the cell type composition, single cell transcriptomic profiling revealed distinct cell types including proliferative cells and stem cells, progenitors, cellular entities of the absorptive lineage, Enterocytes and Microfold-like cells. Cells of the secretory lineage were also annotated, but without distinct canonical gene expression patterns. With the organotypical polarisation, protein expression, structural features and the heterogeneous cell composition including the rare Microfold-like cells, the biological scaffold-based tissue model of the intestinal epithelium demonstrates key requisites needed for infection studies with Salmonella. In a second part of this study, a suitable infection protocol of the epithelial tissue model with Salmonella Typhimurium was established, followed by the examination of key features of the infection process. Salmonella adhered to the epithelial microvilli and induced typical membrane ruffling during invasion; interestingly the individual steps of invasion could be observed. After invasion, time course analysis showed that Salmonella resided and proliferated intracellularly, while simultaneously migrating from the apical to the basolateral side of the infected cell. Furthermore, the bacterial morphology changed to a filamentous phenotype; especially when the models have been analysed at late time points after infection. The epithelial cells on the other side released the cytokines Interleukin 8 and Tumour Necrosis Factor α upon bacterial infection in a time-dependent manner. Taken together, Salmonella infection of the intestinal epithelial tissue model recapitulates important steps of the infection process as described in the literature, and hence demonstrates a valid in vitro platform for the investigation of the Salmonella infection process in the human context. During the infection process, intracellular Salmonella populations varied in their bacterial number, which could be attributed to increased intracellular proliferation and demonstrated thereby a heterogeneous behaviour of Salmonella in individual cells. Furthermore, by the application of single cell transcriptomic profiling, the upregulation of Olfactomedin-4 (OLFM4) gene expression was detected; OLFM4 is a protein involved in various functions including cell immunity as well as proliferating signalling pathways and is often used as intestinal stem cell marker. This OLFM4 upregulation was time-dependent, restricted to Salmonella infected cells and seemed to increase with bacterial mass. Investigating the OLFM4 regulatory mechanism, nuclear factor κB induced upregulation could be excluded, whereas inhibition of the Notch signalling led to a decrease of OLFM4 gene and protein expression. Furthermore, Notch inhibition resulted in decreased filamentous Salmonella formation. Taken together, by the use of the introduced primary epithelial tissue model, a heterogeneous intracellular bacterial behaviour was observed and a so far overlooked host cell response - the expression of OLFM4 by individual infected cells - could be identified; although Salmonella Typhimurium is one of the best-studied enteric pathogenic bacteria. This proves the applicability of the introduced tissue model in enteric infection research as well as the importance of new approaches in order to decipher host-pathogen interactions with higher relevance to the host.},
  subject      = {Salmonella typhimurium},
  language  = {en}
}
@phdthesis{Isasa2024,
  author    = {Isasa, Emilie},
  title     = {Relationship between wood properties, drought-induced embolism and environmental preferences across temperate diffuse-porous broadleaved trees},
  doi       = {10.25972/OPUS-30356},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303562},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {In the scope of climate warming and the increase in frequency and intensity of severe heat waves in Central Europe, identification of temperate tree species that are suited to cope with these environmental changes is gaining increasing importance. A number of tree physiological characteristics are associated with drought-stress resistance and survival following severe heat, but recent studies have shown the importance of plant hydraulic and anatomical traits for predicting drought-induced tree mortality, such as vessel diameter, and their potential to predict species distribution in a changing climate. A compilation of large global datasets is required to determine traits related to drought-induced embolism and test whether embolism resistance can be determined solely by anatomical traits. However, most measurements of plant hydraulic traits are labour-intense and prone to measurement artefacts. A fast, accurate and widely applicable technique is necessary for estimating xylem embolism resistance (e.g., water potential at 50\% loss of conductivity, P50), in order to improve forecasts of future forest changes. These traits and their combination must have evolved following the selective pressure of the environmental conditions in which each species occurs. Describing these environmental-trait relationships can be useful to assess potential responses to environmental change and mitigation strategies for tree species, as future warmer temperatures may be compounded by drier conditions.},
  subject      = {Pflanzen{\"o}kologie},
  language  = {en}
}
@phdthesis{Kibe2024,
  author    = {Kibe, Anuja},
  title     = {Translational landscape and regulation of recoding in virus-infected cells},
  doi       = {10.25972/OPUS-31099},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310993},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {RNA viruses rely entirely on the host machinery for their protein synthesis and harbor non-canonical translation mechanisms, such as alternative initiation and programmed -1 ribosomal frameshifting (-1PRF), to suit their specific needs. On the other hand, host cells have developed a variety of defensive strategies to safeguard their translational apparatus and at times transiently shut down global translation. An infection can lead to substantial translational remodeling in cells and translational control is critical during antiviral response. Due to their sheer diversity, this control is likely unique to each RNA virus and the intricacies of post-transcriptional regulation are unclear in certain viral species. Here, we explored different aspects of translational regulation in virus-infected cells in detail. Using ribosome profiling, we extensively characterized the translational landscape in HIV-1 infected T cells, uncovering novel features of gene regulation in both host and virus. Additionally, we show that substantial pausing occurs prior to the frameshift site indicating complex regulatory mechanisms involving upstream viral RNA elements that can act as cis- regulators of frameshifting. We also characterized the mechanistic details of trans- modulation of frameshifting by host- and virus-encoded proteins. Host antiviral protein ZAP-S binds to the SARS-CoV-2 frameshift site and destabilizes the stimulatory structure, leading to frameshift inhibition. On the other hand, EMCV 2A protein stabilizes the viral frameshift site, thereby, activating EMCV frameshifting. While both proteins were shown to be antagonistic in their mechanism, they interact with the host translational machinery. Furthermore, we showed that frameshifting can be regulated not just by proteins, but also by small molecules. High-throughput screening of natural and synthetic compounds identified two potent frameshift inhibitors that also impeded viral replication, namely trichangion and compound 25. Together, this work largely enhances our understanding of gene regulation mechanisms in virus-infected cells and further validates the druggability of viral -1 PRF site.},
  subject      = {Zelle},
  language  = {en}
}
@phdthesis{BakariSoale2024,
  author    = {Bakari Soale, Majeed},
  title     = {Regulation of the Variant Surface Glycoprotein (VSG) Expression and Characterisation of the Nucleolar DExD/H box Protein Hel66 in \(Trypanosoma\) \(brucei\)},
  doi       = {10.25972/OPUS-25809},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258090},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The variant surface glycoprotein (VSG) of African trypanosomes plays an essential role in protecting the parasites from host immune factors. These trypanosomes undergo antigenic variation resulting in the expression of a single VSG isoform out of a repertoire of around 2000 genes. The molecular mechanism central to the expression and regulation of the VSG is however not fully understood. Gene expression in trypanosomes is unusual due to the absence of typical RNA polymerase II promoters and the polycistronic transcription of genes. The regulation of gene expression is therefore mainly post-transcriptional. Regulatory sequences, mostly present in the 3´ UTRs, often serve as key elements in the modulation of the levels of individual mRNAs. In T. brucei VSG genes, a 100 \% conserved 16mer motif within the 3´ UTR has been shown to modulate the stability of VSG transcripts and hence their expression. As a stability-associated sequence element, the absence of nucleotide substitutions in the motif is however unusual. It was therefore hypothesised that the motif is involved in other essential roles/processes besides stability of the VSG transcripts. In this study, it was demonstrated that the 100 \% conservation of the 16mer motif is not essential for cell viability or for the maintenance of functional VSG protein levels. It was further shown that the intact motif in the active VSG 3´ UTR is neither required to promote VSG silencing during switching nor is it needed during differentiation from bloodstream forms to procyclic forms. Crosstalk between the VSG and procyclin genes during differentiation to the insect vector stage is also unaffected in cells with a mutated 16mer motif. Ectopic overexpression of a second VSG however requires the intact motif to trigger silencing and exchange of the active VSG, suggesting a role for the motif in transcriptional VSG switching. The 16mer motif therefore plays a dual role in VSG in situ switching and stability of VSG transcripts. The additional role of the 16mer in the essential process of antigenic variation appears to be the driving force for the 100 \% conservation of this RNA motif. A screen aimed at identifying candidate RNA-binding proteins interacting with the 16mer motif, led to the identification of a DExD/H box protein, Hel66. Although the protein did not appear to have a direct link to the 16mer regulation of VSG expression, the DExD/H family of proteins are important players in the process of ribosome biogenesis. This process is relatively understudied in trypanosomes and so this candidate was singled out for detailed characterisation, given that the 16mer story had reached a natural end point. Ribosome biogenesis is a major cellular process in eukaryotes involving ribosomal RNA, ribosomal proteins and several non-ribosomal trans-acting protein factors. The DExD/H box proteins are the most important trans-acting protein factors involved in the biosynthesis of ribosomes. Several DExD/H box proteins have been directly implicated in this process in yeast. In trypanosomes, very few of this family of proteins have been characterised and therefore little is known about the specific roles they play in RNA metabolism. Here, it was shown that Hel66 is involved in rRNA processing during ribosome biogenesis. Hel66 localises to the nucleolus and depleting the protein led to a severe growth defect. Loss of the protein also resulted in a reduced rate of global translation and accumulation of rRNA processing intermediates of both the small and large ribosomal subunits. Hel66 is therefore an essential nucleolar DExD/H protein involved in rRNA processing during ribosome biogenesis. As very few protein factors involved in the processing of rRNAs have been described in trypanosomes, this finding represents an important platform for future investigation of this topic.},
  subject      = {Trypanosoma brucei},
  language  = {en}
}
@phdthesis{Hock2024,
  author    = {Hock, Michael},
  title     = {Methods for Homogenization of Spatio-Temporal B\(_0\) Magnetic Field Variations in Cardiac MRI at Ultra-High Field Strength},
  doi       = {10.25972/OPUS-34821},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348213},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Cardiovascular disease is one of the leading causes of death worldwide and, so far, echocardiography, nuclear cardiology, and catheterization are the gold standard techniques used for its detection. Cardiac magnetic resonance (CMR) can replace the invasive imaging modalities and provide a "one-stop shop" characterization of the cardiovascular system by measuring myocardial tissue structure, function and perfusion of the heart, as well as anatomy of and flow in the coronary arteries. In contrast to standard clinical magnetic resonance imaging (MRI) scanners, which are often operated at a field strength of 1.5 or 3 Tesla (T), a higher resolution and subsequent cardiac parameter quantification could potentially be achieved at ultra-high field, i.e., 7 T and above. Unique insights into the pathophysiology of the heart are expected from ultra-high field MRI, which offers enhanced image quality in combination with novel contrast mechanisms, but suffers from spatio-temporal B0 magnetic field variations. Due to the resulting spatial misregistration and intra-voxel dephasing, these B0-field inhomogeneities generate a variety of undesired image artifacts, e.g., artificial image deformation. The resulting macroscopic field gradients lead to signal loss, because the effective transverse relaxation time T2* is shortened. This affects the accuracy of T2* measurements, which are essential for myocardial tissue characterization. When steady state free precession-based pulse sequences are employed for image acquisition, certain off-resonance frequencies cause signal voids. These banding artifacts complicate the proper marking of the myocardium and, subsequently, systematic errors in cardiac function measurements are inevitable. Clinical MR scanners are equipped with basic shim systems to correct for occurring B0-field inhomogeneities and resulting image artifacts, however, these are not sufficient for the advanced measurement techniques employed for ultra-high field MRI of the heart. Therefore, this work focused on the development of advanced B0 shimming strategies for CMR imaging applications to correct the spatio-temporal B0 field variations present in the human heart at 7 T. A novel cardiac phase-specific shimming (CPSS) technique was set up, which featured a triggered B0 map acquisition, anatomy-matched selection of the shim-region-of-interest (SROI), and calibration-based B0 field modeling. The influence of technical limitations on the overall spherical harmonics (SH) shim was analyzed. Moreover, benefits as well as pitfalls of dynamic shimming were debated in this study. An advanced B0 shimming strategy was set up and applied in vivo, which was the first implementation of a heart-specific shimming approach in human UHF MRI at the time. The spatial B0-field patterns which were measured in the heart throughout this study contained localized spots of strong inhomogeneities. They fluctuated over the cardiac cycle in both size and strength, and were ideally addressed using anatomy-matched SROIs. Creating a correcting magnetic field with one shim coil, however, generated eddy currents in the surrounding conducting structures and a resulting additional, unintended magnetic field. Taking these shim-to-shim interactions into account via calibration, it was demonstrated for the first time that the non-standard 3rd-order SH terms enhanced B0-field homogeneity in the human heart. However, they were attended by challenges for the shim system hardware employed in the presented work, which was indicated by the currents required to generate the optimal 3rd-order SH terms exceeding the dynamic range of the corresponding shim coils. To facilitate dynamic shimming updated over the cardiac cycle for cine imaging, the benefit of adjusting the oscillating CPSS currents was found to be vital. The first in vivo application of the novel advanced B0 shimming strategy mostly matched the simulations. The presented technical developments are a basic requirement to quantitative and functional CMR imaging of the human heart at 7 T. They pave the way for numerous clinical studies about cardiac diseases, and continuative research on dedicated cardiac B0 shimming, e.g., adapted passive shimming and multi-coil technologies.},
  subject      = {Kernspintomografie},
  language  = {en}
}
@phdthesis{MaierverhHartmann2024,
  author    = {Maier [verh. Hartmann], Carina Ramona},
  title     = {Regulation of the Mevalonate Pathway by the Deubiquitinase USP28 in Squamous Cancer},
  doi       = {10.25972/OPUS-34874},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348740},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The reprogramming of metabolic pathways is a hallmark of cancer: Tumour cells are dependent on the supply with metabolites and building blocks to fulfil their increased need as highly proliferating cells. Especially de novo synthesis pathways are upregulated when the cells of the growing tumours are not able to satisfy the required metabolic levels by uptake from the environment. De novo synthesis pathways are often under the control of master transcription factors which regulate the gene expression of enzymes involved in the synthesis process. The master regulators for de novo fatty acid synthesis and cholesterogenesis are sterol regulatory element-binding proteins (SREBPs). While SREBP1 preferably controls the expression of enzymes involved in fatty acid synthesis, SREBP2 regulates the transcription of the enzymes of the mevalonate pathway and downstream processes namely cholesterol, isoprenoids and building blocks for ubiquinone synthesis. SREBP activity is tightly regulated at different levels: The post-translational modification by ubiquitination decreases the stability of active SREBPs. The attachment of K48-linked ubiquitin chains marks the transcription factors for the proteasomal degradation. In tumour cells, high levels of active SREBPs are essential for the upregulation of the respective metabolic pathways. The increased stability and activity of SREBPs were investigated in this thesis. SREBPs are ubiquitinated by the E3 ligase Fbw7 which leads to the subsequential proteolysis of the transcription factors. The work conducted in this thesis identified the counteracting deubiquitination enzyme USP28 which removes the ubiquitin chains from SREBPs and prevents their proteasomal degradation. It further revealed that the stabilization of SREBP2 by USP28 plays an important role in the context of squamous cancers. Increased USP28 levels are associated with a poor survival in patients with squamous tumour subtypes. It was shown that reduced USP28 levels in cell lines and in vivo result in a decrease of SREBP2 activity and downregulation of the mevalonate pathway. This manipulation led to reduced proliferation and tumour growth. A direct comparison of adenocarcinomas and squamous cell carcinomas in lung cancer patients revealed an upregulation of USP28 as well as SREBP2 and its target genes. Targeting the USP28-SREBP2 regulatory axis in squamous cell lines by inhibitors also reduced cell viability and proliferation. In conclusion, this study reports evidence for the importance of the mevalonate pathway regulated by the USP28-SREBP2 axis in tumour initiation and progression of squamous cancer. The combinatorial inhibitor treatment of USP28 and HMGCR, the rate limiting enzyme of the mevalonate pathway, by statins opens the possibility for a targeted therapeutic treatment of squamous cancer patients.},
  subject      = {Ubiquitin},
  language  = {en}
}
@phdthesis{Englert2024,
  author    = {Englert, Nils},
  title     = {Die Rolle der NO-sensitiven Guanylyl-Cyclase in der Lungenfibrose der Maus},
  doi       = {10.25972/OPUS-34805},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348054},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Die idiopathische Lungenfibrose (IPF) stellt eine chronische Krankheit mit einer schlechten Prognose dar. Die Erkrankung zeichnet sich durch ein dysfunktionales Alveolarepithel, die Formation von α-smooth muscle actin (α-SMA)-positiven Myofibroblasten, eine starke Kollagendeposition sowie eine fehlgeleitete Inflammation aus. In der Vermittlung dieser pro-fibrotischen Effekte spielt das Zytokin transforming growth factor β (TGF-β) eine Schl{\"u}sselrolle. Aufgrund des t{\"o}dlichen Verlaufs der IPF und der limitierten Therapieoptionen ist die Entdeckung neuer Behandlungsans{\"a}tze erforderlich. Der NO/cGMP-Signalweg ist in der Modulation grundlegender physiologischer Vorg{\"a}nge wie der Blutdruckregulation und der Peristaltik involviert. Hierbei spielt die NO-sensitive Guanylyl-Cyclase (NO-GC) als NO-Rezeptor eine fundamentale Rolle. In der Lunge wird die NO-GC in glatten Muskelzellen und Perizyten exprimiert. W{\"a}hrend das Enzym in glatten Muskelzellen die Relaxation der glatten Muskulatur vermittelt, reguliert die NO-GC in Perizyten die Angiogenese, die Kapillardurchl{\"a}ssigkeit und den Blutfluss. Neben den physiologischen Aufgaben wurden anti-fibrotische sowie anti-inflammatorische Effekte der NO-GC in Herz, Leber, Niere und Haut beschrieben. Daher wurde im Rahmen dieser Arbeit die NO-GC auf eine anti-fibrotische und anti-inflammatorische Bedeutung in der Lungenfibrose der Maus {\"u}berpr{\"u}ft. Hierzu wurden Wildtyp- (WT) und globale NO-GC-Knockout-M{\"a}use (GCKO) untersucht. Die Fibrose wurde durch einmalige, orotracheale Bleomycin-Gabe induziert und zu unterschiedlichen Zeitpunkten (Tag 7 und 21) untersucht. Unbehandelte (Tag 0) Tiere dienten als Kontrolle. Im ersten Teil dieser Arbeit wurde die NO-GC auf eine anti-fibrotische Wirkung untersucht. Mittels Immunfluoreszenz wurde das Verhalten der α-SMA-positiven Myofibroblasten in den platelet-derived growth factor receptor β (PDGFRβ)-positiven fibrotischen Regionen untersucht. Der Kollagengehalt wurde mithilfe eines Hydroxyprolin-Kollagenassays ermittelt. Die untersuchten Fibrose-Kriterien waren in beiden Genotypen an Tag 21 st{\"a}rker ausgepr{\"a}gt als an Tag 7. An Tag 21 konnten im GCKO mehr α-SMA-positive Myofibroblasten, ausgepr{\"a}gtere PDGFRβ-positive fibrotische Areale und ein h{\"o}herer Kollagengehalt als im WT festgestellt werden. Zudem zeigten die GCKO-Tiere ein schlechteres {\"U}berleben als WT-M{\"a}use. Diese Ergebnisse wiesen auf eine {\"u}berschießende fibrotische Antwort im GCKO und somit auf eine anti-fibrotische Wirkung der NO-GC in der Bleomycin-induzierten Lungenfibrose hin. Dass an Tag 21 die Fibrose im GCKO st{\"a}rker ausfiel als im WT, konnte mit dem signifikant h{\"o}heren TGF-β-Gehalt in der bronchoalveol{\"a}ren Lavagefl{\"u}ssigkeit (BALF) im GCKO erkl{\"a}rt werden. Das Fehlen der NO-GC im GCKO k{\"o}nnte zu einem Wegfall der Inhibierung der TGF-β-vermittelten, pro-fibrotischen Effekte durch die NO-GC f{\"u}hren. Weitere Studien sind erforderlich, um die Hypothese zu belegen und zugrundeliegende Mechanismen aufzukl{\"a}ren. Die de novo Entstehung von Myofibroblasten, die maßgeblich an der Kollagensynthese beteiligt sind, stellt ein entscheidendes Fibrose-Merkmal dar. Umso bedeutender ist die Identifikation zweier Myofibroblasten-Subtypen, die sich in Lokalisation, NO-GC-Expression und Herkunft unterscheiden: (1) interstitielle, NO-GC-positive Myofibroblasten, die von Perizyten abstammen und Kollagen Typ I produzieren, und (2) intra-alveol{\"a}re, NO-GC-negative Myofibroblasten, deren Ursprung noch nicht abschließend gekl{\"a}rt ist. Die Anwesenheit beider Myofibroblasten-Typen konnte zu beiden untersuchten Zeitpunkten nach Bleomycin-Gabe best{\"a}tigt werden. Die NO-GC-Expression der Alveolarwand-st{\"a}ndigen Myofibroblasten, deren Abstammung von NO-GC-positiven Perizyten sowie deren dauerhafte Pr{\"a}senz sprechen f{\"u}r eine relevante Rolle der NO-GC in der murinen Lungenfibrose. In weiteren Untersuchungen m{\"u}ssen die exakten Funktionen und spezifische Marker der Myofibroblasten-Subtypen identifiziert werden. Im zweiten Teil dieser Arbeit wurde die NO-GC auf anti-inflammatorische Effekte in der Bleomycin-induzierten Lungenfibrose untersucht. Mittels HE-F{\"a}rbung und Immunfluoreszenz wurden lymphozyt{\"a}re Infiltrate an Tag 21 im GCKO festgestellt, was auf einen modulatorischen Einfluss der NO-GC auf das Immunsystem hindeutete. An Tag 21 wurden in der BALF von GCKO-Tieren signifikant mehr Gesamtimmunzellen, Lymphozyten und neutrophile Granulozyten als im WT gez{\"a}hlt, was auf eine starke Einwanderung von Immunzellen und somit auf eine ausgepr{\"a}gte Entz{\"u}ndung in GCKO-Lungen hinwies. Folglich k{\"o}nnte die NO-GC eine anti-inflammatorische Rolle {\"u}ber die Regulation der Immigration von Immunzellen in der Bleomycin-induzierten Lungenfibrose spielen. In der Literatur werden pro- und anti-fibrotische Effekte der Immunzellen in der murinen Lungenfibrose diskutiert. Durch Korrelationsanalysen wurde ein positiver Zusammenhang zwischen der Gesamtimmunzellzahl und der TGF-β-Konzentration an Tag 21 festgestellt. In verschiedenen Studien wurde ein pro-fibrotischer Einfluss der Immunzellen {\"u}ber die Aktivierung/Sekretion von TGF-β beschrieben. Die Abwesenheit der NO-GC im GCKO k{\"o}nnte also {\"u}ber die verst{\"a}rkte Immigration von Immunzellen in einem erh{\"o}hten TGF-β-Gehalt resultieren und so zu einer {\"u}berschießenden fibrotischen Reaktion an Tag 21 f{\"u}hren. Auf welche Weise die NO-GC die Einwanderung der Immunzellen in der Bleomycin-induzierten Lungenfibrose beeinflusst, muss in weiteren Studien untersucht werden. Zusammenfassend deuten die Daten dieser Arbeit auf eine anti-inflammatorische und anti-fibrotische Rolle der NO-GC in der Lungenfibrose der Maus hin.},
  subject      = {Lunge},
  language  = {de}
}
@phdthesis{Andelovic2024,
  author    = {Andelovic, Kristina},
  title     = {Characterization of arterial hemodynamics using mouse models of atherosclerosis and tissue-engineered artery models},
  doi       = {10.25972/OPUS-30360},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303601},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Within this thesis, three main approaches for the assessment and investigation of altered hemodynamics like wall shear stress, oscillatory shear index and the arterial pulse wave velocity in atherosclerosis development and progression were conducted: 1. The establishment of a fast method for the simultaneous assessment of 3D WSS and PWV in the complete murine aortic arch via high-resolution 4D-flow MRI 2. The utilization of serial in vivo measurements in atherosclerotic mouse models using high-resolution 4D-flow MRI, which were divided into studies describing altered hemodynamics in late and early atherosclerosis 3. The development of tissue-engineered artery models for the controllable application and variation of hemodynamic and biologic parameters, divided in native artery models and biofabricated artery models, aiming for the investigation of the relationship between atherogenesis and hemodynamics Chapter 2 describes the establishment of a method for the simultaneous measurement of 3D WSS and PWV in the murine aortic arch at, using ultra high-field MRI at 17.6T [16], based on the previously published method for fast, self-navigated wall shear stress measurements in the murine aortic arch using radial 4D-phase contrast MRI at 17.6 T [4]. This work is based on the collective work of Dr. Patrick Winter, who developed the method and the author of this thesis, Kristina Andelovic, who performed the experiments and statistical analyses. As the method described in this chapter is basis for the following in vivo studies and undividable into the sub-parts of the contributors without losing important information, this chapter was not split into the single parts to provide fundamental information about the measurement and analysis methods and therefore better understandability for the following studies. The main challenge in this chapter was to overcome the issue of the need for a high spatial resolution to determine the velocity gradients at the vascular wall for the WSS quantification and a high temporal resolution for the assessment of the PWV without prolonging the acquisition time due to the need for two separate measurements. Moreover, for a full coverage of the hemodynamics in the murine aortic arch, a 3D measurement is needed, which was achieved by utilization of retrospective navigation and radial trajectories, enabling a highly flexible reconstruction framework to either reconstruct images at lower spatial resolution and higher frame rates for the acquisition of the PWV or higher spatial resolution and lower frame rates for the acquisition of the 3D WSS in a reasonable measurement time of only 35 minutes. This enabled the in vivo assessment of all relevant hemodynamic parameters related to atherosclerosis development and progression in one experimental session. This method was validated in healthy wild type and atherosclerotic Apoe-/- mice, indicating no differences in robustness between pathological and healthy mice. The heterogeneous distribution of plaque development and arterial stiffening in atherosclerosis [10, 12], however, points out the importance of local PWV measurements. Therefore, future studies should focus on the 3D acquisition of the local PWV in the murine aortic arch based on the presented method, in order to enable spatially resolved correlations of local arterial stiffness with other hemodynamic parameters and plaque composition. In Chapter 3, the previously established methods were used for the investigation of changing aortic hemodynamics during ageing and atherosclerosis in healthy wild type and atherosclerotic Apoe-/- mice using the previously established methods [4, 16] based on high-resolution 4D-flow MRI. In this work, serial measurements of healthy and atherosclerotic mice were conducted to track all changes in hemodynamics in the complete aortic arch over time. Moreover, spatially resolved 2D projection maps of WSS and OSI of the complete aortic arch were generated. This important feature allowed for the pixel-wise statistical analysis of inter- and intragroup hemodynamic changes over time and most importantly - at a glance. The study revealed converse differences of local hemodynamic profiles in healthy WT and atherosclerotic Apoe-/- mice, with decreasing longWSS and increasing OSI, while showing constant PWV in healthy mice and increasing longWSS and decreasing OSI, while showing increased PWV in diseased mice. Moreover, spatially resolved correlations between WSS, PWV, plaque and vessel wall characteristics were enabled, giving detailed insights into coherences between hemodynamics and plaque composition. Here, the circWSS was identified as a potential marker of plaque size and composition in advanced atherosclerosis. Moreover, correlations with PWV values identified the maximum radStrain could serve as a potential marker for vascular elasticity. This study demonstrated the feasibility and utility of high-resolution 4D flow MRI to spatially resolve, visualize and analyze statistical differences in all relevant hemodynamic parameters over time and between healthy and diseased mice, which could significantly improve our understanding of plaque progression towards vulnerability. In future studies the relation of vascular elasticity and radial strain should be further investigated and validated with local PWV measurements and CFD. Moreover, the 2D histological datasets were not reflecting the 3D properties and regional characteristics of the atherosclerotic plaques. Therefore, future studies will include 3D plaque volume and composition analysis like morphological measurements with MRI or light-sheet microscopy to further improve the analysis of the relationship between hemodynamics and atherosclerosis. Chapter 4 aimed at the description and investigation of hemodynamics in early stages of atherosclerosis. Moreover, this study included measurements of hemodynamics at baseline levels in healthy WT and atherosclerotic mouse models. Due to the lack of hemodynamic-related studies in Ldlr-/- mice, which are the most used mouse models in atherosclerosis research together with the Apoe-/- mouse model, this model was included in this study to describe changing hemodynamics in the aortic arch at baseline levels and during early atherosclerosis development and progression for the first time. In this study, distinct differences in aortic geometries of these mouse models at baseline levels were described for the first time, which result in significantly different flow- and WSS profiles in the Ldlr-/- mouse model. Further basal characterization of different parameters revealed only characteristic differences in lipid profiles, proving that the geometry is highly influencing the local WSS in these models. Most interestingly, calculation of the atherogenic index of plasma revealed a significantly higher risk in Ldlr-/- mice with ongoing atherosclerosis development, but significantly greater plaque areas in the aortic arch of Apoe-/- mice. Due to the given basal WSS and OSI profile in these two mouse models - two parameters highly influencing plaque development and progression - there is evidence that the regional plaque development differs between these mouse models during very early atherogenesis. Therefore, future studies should focus on the spatiotemporal evaluation of plaque development and composition in the three defined aortic regions using morphological measurements with MRI or 3D histological analyses like LSFM. Moreover, this study offers an excellent basis for future studies incorporating CFD simulations, analyzing the different measured parameter combinations (e.g., aortic geometry of the Ldlr-/- mouse with the lipid profile of the Apoe-/- mouse), simulating the resulting plaque development and composition. This could help to understand the complex interplay between altered hemodynamics, serum lipids and atherosclerosis and significantly improve our basic understanding of key factors initiating atherosclerosis development. Chapter 5 describes the establishment of a tissue-engineered artery model, which is based on native, decellularized porcine carotid artery scaffolds, cultured in a MRI-suitable bioreactor-system [23] for the investigation of hemodynamic-related atherosclerosis development in a controllable manner, using the previously established methods for WSS and PWV assessment [4, 16]. This in vitro artery model aimed for the reduction of animal experiments, while simultaneously offering a simplified, but completely controllable physical and biological environment. For this, a very fast and gentle decellularization protocol was established in a first step, which resulted in porcine carotid artery scaffolds showing complete acellularity while maintaining the extracellular matrix composition, overall ultrastructure and mechanical strength of native arteries. Moreover, a good cellular adhesion and proliferation was achieved, which was evaluated with isolated human blood outgrowth endothelial cells. Most importantly, an MRI-suitable artery chamber was designed for the simultaneous cultivation and assessment of high-resolution 4D hemodynamics in the described artery models. Using high-resolution 4D-flow MRI, the bioreactor system was proven to be suitable to quantify the volume flow, the two components of the WSS and the radStrain as well as the PWV in artery models, with obtained values being comparable to values found in literature for in vivo measurements. Moreover, the identification of first atherosclerotic processes like intimal thickening is achievable by three-dimensional assessment of the vessel wall morphology in the in vitro models. However, one limitation is the lack of a medial smooth muscle cell layer due to the dense ECM. Here, the utilization of the laser-cutting technology for the generation of holes and / or pits on a microscale, eventually enabling seeding of the media with SMCs showed promising results in a first try and should be further investigated in future studies. Therefore, the proposed artery model possesses all relevant components for the extension to an atherosclerosis model which may pave the way towards a significant improvement of our understanding of the key mechanisms in atherogenesis. Chapter 6 describes the development of an easy-to-prepare, low cost and fully customizable artery model based on biomaterials. Here, thermoresponsive sacrificial scaffolds, processed with the technique of MEW were used for the creation of variable, biomimetic shapes to mimic the geometric properties of the aortic arch, consisting of both, bifurcations and curvatures. After embedding the sacrificial scaffold into a gelatin-hydrogel containing SMCs, it was crosslinked with bacterial transglutaminase before dissolution and flushing of the sacrificial scaffold. The hereby generated channel was subsequently seeded with ECs, resulting in an easy-to-prepare, fast and low-cost artery model. In contrast to the native artery model, this model is therefore more variable in size and shape and offers the possibility to include smooth muscle cells from the beginning. Moreover, a custom-built and highly adaptable perfusion chamber was designed specifically for the scaffold structure, which enabled a one-step creation and simultaneously offering the possibility for dynamic cultivation of the artery models, making it an excellent basis for the development of in vitro disease test systems for e.g., flow-related atherosclerosis research. Due to time constraints, the extension to an atherosclerosis model could not be achieved within the scope of this thesis. Therefore, future studies will focus on the development and validation of an in vitro atherosclerosis model based on the proposed bi- and three-layered artery models. In conclusion, this thesis paved the way for a fast acquisition and detailed analyses of changing hemodynamics during atherosclerosis development and progression, including spatially resolved analyses of all relevant hemodynamic parameters over time and in between different groups. Moreover, to reduce animal experiments, while gaining control over various parameters influencing atherosclerosis development, promising artery models were established, which have the potential to serve as a new platform for basic atherosclerosis research.},
  subject      = {H{\"a}modynamik},
  language  = {en}
}
@phdthesis{He2024,
  author    = {He, Feng},
  title     = {Drug Discovery based on Oxidative Stress and HDAC6 for Treatment of Neurodegenerative Diseases},
  doi       = {10.25972/OPUS-25349},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-253497},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Most antioxidants reported so far only achieved limited success in AD clinical trials. Growing evidences suggest that merely targeting oxidative stress will not be sufficient to fight AD. While multi-target directed ligands could synergistically modulate different steps in the neurodegenerative process, offering a promising potential for treatment of this complex disease. Fifteen target compounds have been designed by merging melatonin and ferulic acid into the cap group of a tertiary amide HDAC6 inhibitor. Compound 10b was screened as the best hybrid molecule exhibit potent HDAC6 inhibition and potent antioxidant capacity. Compound 10b also alleviated LPS-induced microglia inflammation and led to a switch from neurotoxic M1 to the neuroprotective M2 microglial phenotype. Moreover, compound 10b show pronounced attenuation of spatial working memory and long-term memory damage in an in vivo AD mouse model. Compound 10b can be a potentially effective drug candidate for treatment of AD and its druggability worth to be further studied. We have designed ten novel neuroprotectants by hybridizing with several common antioxidants, including ferulic acid, melatonin, lipoic acid, and trolox. The trolox hybrid compound exhibited the most potent neuroprotective effects in multiple neuroprotection assays. Besides, we identified the synergistic effects between trolox and vitamin K derivative, and our trolox hybrid compound showed comparable neuroprotection with the mixture of trolox and vitamin K derivative. We have designed and synthesized 24 quinone derivatives based on five kinds of different quinones including ubiquinone, 2,3,5-trimethyl-1,4-benzoquinone, memoquin, thymoquinone, and anthraquinone. Trimethylbenzoquinone and thymoquinone derivatives showed more potent neuroprotection than other quinones in oxytosis assay. Therefore, trimethylbenzoquinone and thymoquinone derivatives can be used as lead compounds for further mechanism study and drug discovery for treatment of neurodegenerative disease. We designed a series of photoswitchable HDAC inhibitors, which could be effective molecular tools due to the high spatial and temporal resolution. In total 23 target compounds were synthesized and photophysicochemically characterized. Azoquinoline-based compounds possess more thermally stable cis-isomers in buffer solution, which were further tested in enzyme-based HDAC inhibition assay. However, none of those tested compounds show significant differences in activities between trans-isomers and corresponding cis-isomers.},
  subject      = {Alzheimerkrankheit},
  language  = {en}
}
@phdthesis{XavierdeSouza2024,
  author    = {Xavier de Souza, Aline},
  title     = {Ecophysiological adaptations of the cuticular water permeability within the Solanaceae family},
  doi       = {10.25972/OPUS-22539},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225395},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The cuticle, a complex lipidic layer synthesized by epidermal cells, covers and protects primary organs of all land plants. Its main function is to avoid plant desiccation by limiting non-stomatal water loss. The cuticular properties vary widely among plant species. So far, most of the cuticle-related studies have focused on a limited number of species, and studies addressing phylogenetically related plant species are rare. Moreover, comparative studies among organs from the same plant species are still scarce. Thus, this study focus on organ-specificities of the cuticle within and between plant species of the Solanaceae family. Twenty-seven plant species of ten genera, including cultivated and non- cultivated species, were investigated to identify potential cuticular similarities. Structural, chemical and functional traits of fully expanded leaves, inflated fruiting calyces, and ripe fruits were analyzed. The surface morphology was investigated by scanning electron microscopy. Leaves were mainly amphistomatic and covered by an epicuticular wax film. The diversity and distribution of trichomes varied among species. Only the leaves of S. grandiflora were glabrous. Plant species of the Leptostemonum subgenus had numerous prickles and non-glandular stellate trichomes. Fruits were stomata-free, except for S. muricatum, and a wax film covered their surface. Last, lenticel- like structures and remaining scars of broken trichomes were found on the surface of some Solanum fruits. Cuticular water permeability was used as indicators of the cuticular transpiration barrier efficiency. The water permeability differed among plant species, organs and fruit types with values ranging up to one hundred-fold. The minimum leaf conductance ranged from 0.35 × 10-5 m s-1 in S. grandiflora to 31.54 × 10-5 m s-1 in S. muricatum. Cuticular permeability of fruits ranged from 0.64 × 10-5 m s-1 in S. dulcamara (fleshy berry) to 34.98 × 10-5 m s-1 in N. tabacum (capsule). Generally, the cuticular water loss of dry fruits was about to 5-fold higher than that of fleshy fruits. Interestingly, comparisons between cultivated and non-cultivated species showed that wild species have the most efficient cuticular transpiration barrier in leaves and fruits. The average permeability of leaves and fruits of wild plant species was up to three-fold lower in comparison to the cultivated ones. Moreover, ripe fruits of P. ixocarpa and P. peruviana showed two-times lower cuticular transpiration when enclosed by the inflated fruiting calyx. The cuticular chemical composition was examined using gas chromatography. Very-long-chain aliphatic compounds primarily composed the cuticular waxes, being mostly dominated by n- alkanes (up to 80\% of the total wax load). Primary alkanols, alkanoic acids, alkyl esters and branched iso- and anteiso-alkanes were also frequently found. Although in minor amounts, sterols, pentacyclic triterpenoids, phenylmethyl esters, coumaric acid esters, and tocopherols were identified in the cuticular waxes. Cuticular wax coverages highly varied in solanaceous (62- fold variation). The cuticular wax load of fruits ranged from 0.55 μg cm-2 (Nicandra physalodes) to 33.99 μg cm-2 (S. pennellii), whereas the wax amount of leaves varied from 0.90 μg cm-2 (N. physalodes) to 28.42 μg cm-2 (S. burchellii). Finally, the wax load of inflated fruiting calyces ranged from 0.56 μg cm-2 in P. peruviana to 2.00 μg cm-2 in N. physalodes. For the first time, a comparative study on the efficiency of the cuticular transpiration barrier in different plant organs of closely related plant species was conducted. Altogether, the cuticular chemical variability found in solanaceous species highlight species-, and organ-specific wax biosynthesis. These chemical variabilities might relate to the waterproofing properties of the plant cuticle, thereby influencing leaf and fruit performances. Additionally, the high cuticular water permeabilities of cultivated plant species suggest a potential existence of a trade-off between fruit organoleptic properties and the efficiency of the cuticular transpiration barrier. Last, the high cuticular water loss of the solanaceous dry fruits might be a physiological adaptation favouring seed dispersion.},
  subject      = {Kutikula},
  language  = {en}
}
@phdthesis{Nadernezhad2024,
  author    = {Nadernezhad, Ali},
  title     = {Engineering approaches in biofabrication of vascularized structures},
  doi       = {10.25972/OPUS-34589},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-345892},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Biofabrication technologies must address numerous parameters and conditions to reconstruct tissue complexity in vitro. A critical challenge is vascularization, especially for large constructs exceeding diffusion limits. This requires the creation of artificial vascular structures, a task demanding the convergence and integration of multiple engineering approaches. This doctoral dissertation aims to achieve two primary objectives: firstly, to implement and refine engineering methods for creating artificial microvascular structures using Melt Electrowriting (MEW)-assisted sacrificial templating, and secondly, to deepen the understanding of the critical factors influencing the printability of bioink formulations in 3D extrusion bioprinting. In the first part of this dissertation, two innovative sacrificial templating techniques using MEW are explored. Utilizing a carbohydrate glass as a fugitive material, a pioneering advancement in the processing of sugars with MEW with a resolution under 100 microns was made. Furthermore, by introducing the "print-and-fuse" strategy as a groundbreaking method, biomimetic branching microchannels embedded in hydrogel matrices were fabricated, which can then be endothelialized to mirror in vivo vascular conditions. The second part of the dissertation explores extrusion bioprinting. By introducing a simple binary bioink formulation, the correlation between physical properties and printability was showcased. In the next step, employing state-of-the-art machine-learning approaches revealed a deeper understanding of the correlations between bioink properties and printability in an extended library of hydrogel formulations. This dissertation offers in-depth insights into two key biofabrication technologies. Future work could merge these into hybrid methods for the fabrication of vascularized constructs, combining MEW's precision with fine-tuned bioink properties in automated extrusion bioprinting.},
  subject      = {3D-Druck},
  language  = {en}
}
@phdthesis{Weber2024,
  author    = {Weber, Justus C.},
  title     = {Development and preclinical assessment of ROR2-specific CAR-T cells for the treatment of clear cell renal cell carcinoma and multiple myeloma},
  doi       = {10.25972/OPUS-31039},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310399},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Adoptive immunotherapy using chimeric antigen receptor (CAR)-modified T cells is an effective treatment for hematological malignancies that are refractory to conventional chemotherapy. To address a wider variety of cancer entities, there is a need to identify and characterize additional target antigens for CAR-T cell therapy. The two members of the receptor tyrosine kinase-like orphan receptor family, ROR1 and ROR2, have been found to be overexpressed on cancer cells and to correlate with aggressive cancer phenotypes. Recently, ROR1-specific CAR-T cells have entered testing in phase I clinical trials, encouraging us to assess the suitability of ROR2 as a novel target for CAR-T cell therapy. To study the therapeutic potential of targeting ROR2 in solid and hematological malignancies, we selected two representative cancer entities with high unmet medical need: renal cell carcinoma and multiple myeloma. Our data show that ROR2 is commonly expressed on primary samples and cell lines of clear cell renal cell carcinoma and multiple myeloma. To study the efficacy of ROR2-specific CAR T cell therapy, we designed two CAR constructs with 10-fold binding affinity differences for the same epitope of ROR2. We found both cell products to exhibit antigen-specific anti-tumor reactivity in vitro, including tumor cell lysis, secretion of the effector cytokines interleukin-2 (IL-2) and interferon-gamma (IFNγ), and T cell proliferation. In vivo studies revealed ROR2 specific CAR-T cells to confer durable responses, significant survival benefits and long-term persistence of CAR-expressing T cells. Overall, there was a trend towards more potent anti-tumor efficacy upon treatment with T cells that expressed the CAR with higher affinity for ROR2, both in vitro and in vivo. We performed a preclinical safety and toxicology assessment comprising analyses of ROR2 expression in healthy human and murine tissues, cross-reactivity, and adoptive T cell transfer in immunodeficient mice. We found ROR2 expression to be conserved in mice, and low-level expression was detectable in the male and female reproductive system as well as parts of the gastrointestinal tract. CAR-T cells targeting human ROR2 were found to elicit similarly potent reactivity upon recognition of murine ROR2. In vivo analyses showed transient tissue-specific enrichment and activation of ROR2-specific CAR-T cells in organs with high blood circulation, such as lung, liver, or spleen, without evidence for clinical toxicity or tissue damage as determined by histological analyses. Furthermore, we humanized the CAR binding domain of ROR2-specific CAR-T cells to mitigate the risk of adverse immune reactions and concomitant CAR-T cell rejection. Functional analyses confirmed that humanized CARs retained their specificity and functionality against ROR2-positive tumor cells in vitro. In summary, we show that ROR2 is a prevalent target in RCC and MM, which can be addressed effectively with ROR2-specific CAR-T cells in preclinical models. Our preliminary toxicity studies suggest a favorable safety profile for ROR2-specific CAR-T cells. These findings support the potential to develop ROR2-specific CAR-T cells clinically to obtain cell products with broad utility.},
  subject      = {CAR-T-Zell-Therapie},
  language  = {en}
}
@phdthesis{Albrecht2024,
  author    = {Albrecht, Christina},
  title     = {Kardiorestriktiver Knockout desmosomaler Proteine f{\"u}hrt zu einer Beeintr{\"a}chtigung der elektromechanischen Kopplung ohne mitochondriale Dysfunktion bei arrhythmogener Kardiomyopathie},
  doi       = {10.25972/OPUS-34847},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348472},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Arrhythmogene Kardiomyopathie (ACM) ist eine genetische Herzerkrankung, die durch Herzinsuffizienz, ventrikul{\"a}re Arrhythmien und pl{\"o}tzlichen Herztod gekennzeichnet ist. Mutationen in desmosomalen Proteinen der Zelladh{\"a}sion, wie Plakophilin 2 (PKP2) und Plakoglobin (PG), sind die h{\"a}ufigste Ursache der famili{\"a}ren ACM. Wie gest{\"o}rte Zelladh{\"a}sion zum ACM-Ph{\"a}notyp f{\"u}hrt, ist jedoch nur teilweise gekl{\"a}rt. Potentielle Mechanismen sind eine gest{\"o}rte Kalzium-(Ca2+)-Hom{\"o}ostase, mitochondrialer oxidativer Stress und metabolische St{\"o}rungen. Ziel dieser Studie ist es, die mitochondriale Energetik und die Ca2+ -Hom{\"o}ostase in kardio-restriktiven PKP2-Knockout-M{\"a}usen (KO) im Alter von 4, 8 und 12 Wochen sowie in PG-Knockout- M{\"a}usen im Alter von 6 Wochen zu untersuchen. Vier Wochen alte PKP2-KO-M{\"a}use zeigten fr{\"u}he Anzeichen von ACM, w{\"a}hrend alle anderen Altersgruppen typische Kennzeichen von ACM rekapitulierten. Kontraktilit{\"a}t, die damit verbundenen Ca2+ - Transienten, der Redoxstatus und das mitochondriale Membranpotenzial (ΔΨm) isolierter Kardiomyozyten wurden mit einem IonOptix-System bei elektrischer und β- adrenerger Stimulation untersucht. Alle desmosomalen KO-Kardiomyozyten zeigten eine verringerte diastolische Sarkomerl{\"a}nge, was auf eine diastolische Dysfunktion hinwies. In allen PKP2 KO Kardiomyozyten lag außerdem ein erh{\"o}hter intrazellul{\"a}rer Ca2+ -Spiegel vor, w{\"a}hrend in den PG KO-Kardiomyozyten das intrazellul{\"a}rer Ca2+ unver{\"a}ndert war. PKP2 KO- und PG KO-Kardiomyozyten wiesen keine Ca2+ - Sensibilisierung der Myofilamente auf. Zur weiteren Bewertung der mitochondrialen Funktion wurde eine hochaufl{\"o}sende Respirometrie in isolierten Herzmitochondrien bei gleichzeitiger {\"U}berwachung von ΔΨm in PKP2 KO und PG KO M{\"a}usen durchgef{\"u}hrt, welche in allen Versuchs- und Kontrollgruppen vergleichbar war. Im Verlauf der Versuche blieb der Redoxstatus stabil und es konnte kein Exzess reaktiver Sauerstoffspezies (ROS) festgestellt werden. Daraus konnte gefolgert werden, dass weder PKP2 KO noch PG KO-M{\"a}use eine beeintr{\"a}chtigte mitochondriale Atmung aufwiesen. Diese Studie zeigt, dass isolierte PKP2 KO- oder PG KO-Kardiomyozyten EC-Kopplungsdefekte ohne mitochondriale Dysfunktion aufwiesen. Eine mitochondriale Dysfunktion konnte als treibender Faktor f{\"u}r die Progression des ACM- Ph{\"a}notyps in den vorgestellten Mausmodellen ausgeschlossen werden. Weitere Studien sind erforderlich, um die mitochondriale Funktion im Zusammenhang mit ACM zu entschl{\"u}sseln.},
  subject      = {Herzmuskelkrankheit},
  language  = {de}
}
@phdthesis{Ibrahim2024,
  author    = {Ibrahim, Eslam Samir Ragab},
  title     = {Unraveling the function of the old yellow enzyme OfrA in \(Staphylococcus\) \(aureus\) stress response},
  doi       = {10.25972/OPUS-28960},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289600},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Biological systems are in dynamic interaction. Many responses reside in the core concepts of biological systems interplay (competition and cooperation). In infection situation, the competition between a bacterial system and a host is shaped by many stressors at spatial and temporal determinants. Reactive chemical species are universal stressors against all biological systems since they potentially damage the basic requirements of these systems (nucleic acids, proteins, carbohydrates, and lipids). Either produced endogenously or exogenously, reactive chemical species affect the survival of pathogens including the gram-positive Staphylococcus aureus (S. aureus). Therefore, bacteria developed strategies to overcome the toxicity of reactive species. S. aureus is a widely found opportunistic pathogen. In its niche, S. aureus is in permanent contact with surrounding microbes and host factors. Deciphering the deterministic factors in these interactions could facilitate pinpointing novel bacterial targets. Identifying the aforementioned targets is crucial to develop new strategies not only to kill the pathogenic organisms but also to enhance the normal flora to minimize the pathogenicity and virulence of potential pathogens. Moreover, targeting S. aureus stress response can be used to overcome bacterial resistance against host-derived factors. In this study, I identify a novel S. aureus stress response factor against reactive electrophilic, oxygen, and hypochlorite species to better understand its resilience as a pathogen. Although bacterial stress response is an active research field, gene function is a current bottleneck in characterizing the understudied bacterial strategies to mediate stress conditions. I aimed at understanding the function of a novel protein family integrated in many defense systems of several biological systems. In bacteria, fungi, and plants, old yellow enzymes (OYEs) are widely found. Since the first isolation of the yellow flavoprotein, OYEs are used as biocatalysts for decades to reduce activated C=C bonds in α,β-unsaturated carbonyl compounds. The promiscuity of the enzymatic catalysis is advantageous for industrial applications. However, the physiological function of OYEs, especially in bacteria, is still puzzling. Moreover, the relevance of the OYEs in infection conditions remained enigmatic.   Here, I show that there are two groups of OYEs (OYE flavin oxidoreductase, OfrA and OfrB) that are encoded in staphylococci and some firmicutes. OfrA (SAUSA300_0859) is more conserved than OfrB (SAUSA300_0322) in staphylococci and is a part of the staphylococcal core genome. A reporter system was established to report for ofrA in S. aureus background. The results showed that ofrA is induced under electrophilic, oxidative, and hypochlorite stress. OfrA protects S. aureus against quinone, methylglyoxal, hydrogen peroxide, and hypochlorite stress. Additionally, the results provide evidence that OfrA supports thiol-dependent redox homeostasis. At the host-pathogen interface, OfrA promotes S. aureus fitness in murine macrophage cell line. In whole human blood, OfrA is involved in S. aureus survival indicating a potential clinical relevance to bacteraemia. In addition, ofrA mutation affects the production of the virulence factor staphyloxanthin via the upper mevalonate pathway. In summary, decoding OfrA function and its proposed mechanism of action in S. aureus shed the light on a conserved stress response within multiple organisms.},
  subject      = {Staphylococcus aureus},
  language  = {en}
}
@phdthesis{Adhikari2024,
  author    = {Adhikari, Bikash},
  title     = {Targeted degradation of Myc-interacting oncoproteins},
  doi       = {10.25972/OPUS-31732},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317326},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The hallmark oncoprotein Myc is a major driver of tumorigenesis in various human cancer entities. However, Myc's structural features make it challenging to develop small molecules against it. A promising strategy to indirectly inhibit the function of Myc is by targeting its interactors. Many Myc-interacting proteins have reported scaffolding functions which are difficult to target using conventional occupancy- driven inhibitors. Thus, in this thesis, the proteolysis targeting chimera (PROTAC) approach was used to target two oncoproteins interacting with Myc which promote the oncogenicity of Myc, Aurora-A and WDR5. PROTACs are bifunctional small molecules that bind to the target protein with one ligand and recruit a cellular E3- ligase with the other ligand to induce target degradation via the ubiquitin- proteasome system. So far, the most widely used E3-ligases for PROTAC development are Cereblon (CRBN) and von Hippel-Lindau tumor suppressor (VHL). Furthermore, there are cases of incompatibility between some E3-ligases and proteins to bring about degradation. Hence there is a need to explore new E3- ligases and a demand for a tool to predict degradative E3-ligases for the target protein in the PROTAC field. In the first part, a highly specific mitotic kinase Aurora-A degrader, JB170, was developed. This compound utilized Aurora-A inhibitor alisertib as the target ligand and thalidomide as the E3-ligase CRBN harness. The specificity of JB170 and the ternary complex formation was supported by the interactions between Aurora-A and CRBN. The PROTAC-mediated degradation of Aurora-A induced a distinct S- phase defect rather than mitotic arrest, shown by its catalytic inhibition. The finding demonstrates that Aurora-A has a non-catalytic role in the S-phase. Furthermore, the degradation of Aurora-A led to apoptosis in various cancer cell lines. In the second part, two different series of WDR5 PROTACs based on two protein- protein inhibitors of WDR5 were evaluated. The most efficient degraders from both series recruited VHL as a E3-ligase and showed partial degradation of WDR5. In addition, the degradation efficiency of the PROTACs was significantly affected by the linker nature and length, highlighting the importance of linker length and composition in PROTAC design. The degraders showed modest proliferation defects at best in cancer cell lines. However, overexpression of VHL increased the degradation efficiency and the antiproliferative effect of the PROTACs. In the last part, a rapamycin-based assay was developed to predict the degradative E3-ligase for a target. The assay was validated using the WDR5/VHL and Aurora- A/CRBN pairs. The result that WDR5 is degraded by VHL but not CRBN and Aurora-A is degraded by CRBN, matches observations made with PROTACs. This technique will be used in the future to find effective tissue-specific and essential E3-ligases for targeted degradation of oncoproteins using PROTACs. Collectively, the work presented here provides a strategy to improve PROTAC development and a starting point for developing Aurora-A and WDR5 PROTACs for cancer therapy.},
  subject      = {Degradation},
  language  = {en}
}
@phdthesis{Kuehnemundt2024,
  author    = {K{\"u}hnemundt, Johanna},
  title     = {Defined microphysiologic 3D tumour models with aspects from the tumour microenvironment for the evaluation of cellular immunotherapies},
  doi       = {10.25972/OPUS-27667},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276674},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Adoptive cellular immunotherapy with chimeric antigen receptor (CAR) T cells is highly effective in haematological malignancies. This success, however, has not been achieved in solid tumours so far. In contrast to hematologic malignancies, solid tumours include a hostile tumour microenvironment (TME), that poses additional challenges for curative effects and consistent therapeutic outcome. These challenges manifest in physical and immunological barriers that dampen efficacy of the CAR T cells. Preclinical testing of novel cellular immunotherapies is performed mainly in 2D cell culture and animal experiments. While 2D cell culture is an easy technique for efficacy analysis, animal studies reveal information about toxicity in vivo. However, 2D cell culture cannot fully reflect the complexity observed in vivo, because cells are cultured without anchorage to a matrix and only short-term periods are feasible. Animal studies provide a more complex tissue environment, but xenografts often lack human stroma and tumour inoculation occurs mostly ectopically. This emphasises the need for standardisable and scalable tumour models with incorporated TME-aspects, which enable preclinical testing with enhanced predictive value for the clinical outcome of immunotherapies. Therefore, microphysiologic 3D tumour models based on the biological SISmuc (Small Intestinal mucosa and Submucosa) matrix with preserved basement membrane were engaged and improved in this work to serve as a modular and versatile tumour model for efficacy testing of CAR T cells. In order to reflect a variety of cancer entities, TME-aspects, long-term stability and to enhance the read-out options they were further adapted to achieve scalable and standardisable defined microphysiologic 3D tumour models. In this work, novel culture modalities (semi-static, sandwich-culture) were characterised and established that led to an increased and organised tissue generation and long-term stability. Application of the SISmuc matrix was extended to sarcoma and melanoma models and serial bioluminescence intensity (BLI)-based in vivo imaging analysis was established in the microphysiologic 3D tumour models, which represents a time-efficient read-out method for quality evaluation of the models and treatment efficacy analysis, that is independent of the cell phenotype. Isolation of cancer-associated-fibroblasts (CAFs) from lung (tumour) tissue was demonstrated and CAF-implementation further led to stromal-enriched microphysiologic 3D tumour models with in vivo-comparable tissue-like architecture. Presence of CAFs was confirmed by CAF-associated markers (FAP, α-SMA, MMP-2/-9) and cytokines correlated with CAF phenotype, angiogenesis, invasion and immunomodulation. Additionally, an endothelial cell barrier was implemented for static and dynamic culture in a novel bioreactor set-up, which is of particular interest for the analysis of immune cell diapedesis. Studies in microphysiologic 3D Ewing's sarcoma models indicated that sarcoma cells could be sensitised for GD2-targeting CAR T cells. After enhancing the scale of assessment of the microphysiologic 3D tumour models and improving them for CAR T cell testing, the tumour models were used to analyse their sensitivity towards differently designed receptor tyrosine kinase-like orphan receptor 1 (ROR1) CAR T cells and to study the effects of the incorporated TME-aspects on the CAR T cell treatment respectively. ROR1 has been described as a suitable target for several malignancies including triple negative breast cancer (TNBC), as well as lung cancer. Therefore, microphysiologic 3D TNBC and lung cancer models were established. Analysis of ROR1 CAR T cells that differed in costimulation, spacer length and targeting domain, revealed, that the microphysiologic 3D tumour models are highly sensitive and can distinguish optimal from sub-optimal CAR design. Here, higher affinity of the targeting domain induced stronger anti-tumour efficacy and anti-tumour function depended on spacer length, respectively. Long-term treatment for 14 days with ROR1 CAR T cells was demonstrated in dynamic microphysiologic 3D lung tumour models, which did not result in complete tumour cell removal, whereas direct injection of CAR T cells into TNBC and lung tumour models represented an alternative route of application in addition to administration via the medium flow, as it induced strong anti-tumour response. Influence of the incorporated TME-aspects on ROR1 CAR T cell therapy represented by CAF-incorporation and/or TGF-β supplementation was analysed. Presence of TGF-β revealed that the specific TGF-β receptor inhibitor SD-208 improves ROR1 CAR T cell function, because it effectively abrogated immunosuppressive effects of TGF-β in TNBC models. Implementation of CAFs should provide a physical and immunological barrier towards ROR1 CAR T cells, which, however, was not confirmed, as ROR1 CAR T cell function was retained in the presence of CAFs in stromal-enriched microphysiologic 3D lung tumour models. The absence of an effect of CAF enrichment on CAR T cell efficacy suggests a missing component for the development of an immunosuppressive TME, even though immunomodulatory cytokines were detected in co-culture models. Finally, improved gene-edited ROR1 CAR T cells lacking exhaustion-associated genes (PD-1, TGF-β-receptor or both) were challenged by the combination of CAF-enrichment and TGF-β in microphysiologic 3D TNBC models. Results indicated that the absence of PD-1 and TGF-β receptor leads to improved CAR T cells, that induce strong tumour cell lysis, and are protected against the hostile TME. Collectively, the microphysiologic 3D tumour models presented in this work reflect aspects of the hostile TME of solid tumours, engage BLI-based analysis and provide long-term tissue homeostasis. Therefore, they present a defined, scalable, reproducible, standardisable and exportable model for translational research with enhanced predictive value for efficacy testing and candidate selection of cellular immunotherapy, as exemplified by ROR1 CAR T cells.},
  subject      = {Immuntherapie},
  language  = {en}
}
@phdthesis{Chen2024,
  author    = {Chen, Xinyu},
  title     = {How natural walking changes occipital alpha oscillations and concurrently modulates cognitive processes},
  doi       = {10.25972/OPUS-35295},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352958},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Humans actively interact with the world through a wide range of body movements. To understand human cognition in its natural state, we need to incorporate ecologically relevant body movement into our account. One fundamental body movement during daily life is natural walking. Despite its ubiquity, the impact of natural walking on brain activity and cognition has remained a realm underexplored. In electrophysiology, previous studies have shown a robust reduction of ongoing alpha power in the parieto-occipital cortex during body movements. However, what causes the reduction of ongoing alpha, namely whether this is due to body movement or prevalent sensory input changes, was unknown. To clarify this, study 1 was performed to test if the alpha reduction is dependent on visual input. I compared the resting state alpha power during natural walking and standing, in both light and darkness. The results showed that natural walking led to decreased alpha activity over the occipital cortex compared to standing, regardless of the lighting condition. This suggests that the movement-induced modulation of occipital alpha activity is not driven by visual input changes during walking. I argue that the observed alpha power reduction reflects a change in the state of the subject based on disinhibition induced by walking. Accordingly, natural walking might enhance visual processing and other cognitive processes that involve occipital cortical activity. I first tested this hypothesis in vision. Study 2 was performed to examine the possible effects of natural walking across visual processing stages by assessing various neural markers during different movement states. The findings revealed an amplified early visual response, while a later visual response remain unaffected. A follow-up study 3 replicated the walking-induced enhancement of the early visual evoked potential and showed that the enhancement was dependent on specific stimulus-related parameters (eccentricity, laterality, distractor presence). Importantly, the results provided evidence that the enhanced early visual responses are indeed linked to the modulation of ongoing occipital alpha power. Walking also modulated the stimulus-induced alpha power. Specifically, it showed that when the target appeared in the fovea area without a distractor, walking exhibited a significantly reduced modulation of alpha power, and showed the largest difference to standing condition. This effect of eccentricity indicates that during later visual processing stages, the visual input in the fovea area is less processed than in peripheral areas while walking. The two visual studies showed that walking leads to an enhancement in temporally early visual processes which can be predicted by the walking-induced change in ongoing alpha oscillation likely marking disinhibition. However, while walking affects neural markers of early sensory processes, it does not necessarily lead to a change in the behavioural outcome of a sensory task. The two visual studies suggested that the behavioural outcome seems to be mainly based on later processing stages. To test the effects of walking outside the visual domain, I turned to audition in study 4. I investigated the influence of walking in a particular path vs. simply stepping on auditory processing. Specifically, the study tested whether enhanced processing due to natural walking can be found in primary auditory brain activity and whether the processing preferences are dependent on the walking path. In addition, I tested whether the changed spatial processing that was reported in previous visual studies can be seen in the auditory domain. The results showed enhanced sensory processing due to walking in the auditory domain, which was again linked to the modulation of occipital alpha oscillation. The auditory processing was further dependent on the walking path. Additionally, enhanced peripheral sensory processing, as found in vision, was also present in audition. The findings outside vision supported the idea of natural walking affecting cognition in a rather general way. Therefore in my study 5, I examined the effect of natural walking on higher cognitive processing, namely divergent thinking, and its correlation with the modulation of ongoing alpha oscillation. I analyzed alpha oscillations and behavioural performance during restricted and unrestricted movement conditions while subjects completed a Guilford's alternate uses test. The results showed that natural walking, as well as missing body restriction, reduces the occipital alpha ongoing power independent of the task phase which goes along with higher test scores. The occipital alpha power reduction can therefore be an indicator of a changed state that allows improved higher cognitive processes. In summary, the research presented in this thesis highlights that natural walking can change different processes in the visual and auditory domain as well as higher cognitive processes. The effect can be attributed to the movement of natural walking itself rather than to changes in sensory input during walking. The results further indicate that the walking-induced modulation of ongoing occipital alpha oscillations drives the cognitive effects. We therefore suggest that walking changes the inhibitory state which can influence awareness and attention. Such a mechanism could facilitate an adaptive enhancement in cognitive processes and thereby optimize movement-related behaviour such as navigation.},
  subject      = {Walking},
  language  = {en}
}
@phdthesis{Karwen2024,
  author    = {Karwen, Till},
  title     = {Platelets promote insulin secretion of pancreatic β-cells},
  doi       = {10.25972/OPUS-31393},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313933},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The pancreas is the key organ for the maintenance of euglycemia. This is regulated in particular by α-cell-derived glucagon and β-cell-derived insulin, which are released in response to nutrient deficiency and elevated glucose levels, respectively. Although glucose is the main regulator of insulin secretion, it is significantly enhanced by various potentiators. Platelets are anucleate cell fragments in the bloodstream that are essential for hemostasis to prevent and stop bleeding events. Besides their classical role, platelets were implemented to be crucial for other physiological and pathophysiological processes, such as cancer progression, immune defense, and angiogenesis. Platelets from diabetic patients often present increased reactivity and basal activation. Interestingly, platelets store and release several substances that have been reported to potentiate insulin secretion by β-cells. For these reasons, the impact of platelets on β-cell functioning was investigated in this thesis. Here it was shown that both glucose and a β-cell-derived substance/s promote platelet activation and binding to collagen. Additionally, platelet adhesion specifically to the microvasculature of pancreatic islets was revealed, supporting the hypothesis of their influence on glucose homeostasis. Genetic or pharmacological ablation of platelet functioning and platelet depletion consistently resulted in reduced insulin secretion and associated glucose intolerance. Further, the platelet-derived lipid fraction was found to enhance glucose-stimulated insulin secretion, with 20-hydroxyeicosatetraenoic acid (20-HETE) and possibly also lyso-precursor of platelet-activating factor (lysoPAF) being identified as crucial factors. However, the acute platelet-stimulated insulin secretion was found to decline with age, as did the levels of platelet-derived 20-HETE. In addition to their direct stimulatory effect on insulin secretion, specific defects in platelet activation have also been shown to affect glucose homeostasis by potentially influencing islet vascular development. Taking together, the results of this thesis suggest a direct and indirect mechanism of platelets in the regulation of insulin secretion that ensures glucose homeostasis, especially in young individuals.},
  subject      = {Thrombozyt},
  language  = {en}
}
@phdthesis{Allgaier2024,
  author    = {Allgaier, Johannes},
  title     = {Machine Learning Explainability on Multi-Modal Data using Ecological Momentary Assessments in the Medical Domain},
  doi       = {10.25972/OPUS-35118},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351189},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Introduction. Mobile health (mHealth) integrates mobile devices into healthcare, enabling remote monitoring, data collection, and personalized interventions. Machine Learning (ML), a subfield of Artificial Intelligence (AI), can use mHealth data to confirm or extend domain knowledge by finding associations within the data, i.e., with the goal of improving healthcare decisions. In this work, two data collection techniques were used for mHealth data fed into ML systems: Mobile Crowdsensing (MCS), which is a collaborative data gathering approach, and Ecological Momentary Assessments (EMA), which capture real-time individual experiences within the individual's common environments using questionnaires and sensors. We collected EMA and MCS data on tinnitus and COVID-19. About 15 \% of the world's population suffers from tinnitus. Materials \& Methods. This thesis investigates the challenges of ML systems when using MCS and EMA data. It asks: How can ML confirm or broad domain knowledge? Domain knowledge refers to expertise and understanding in a specific field, gained through experience and education. Are ML systems always superior to simple heuristics and if yes, how can one reach explainable AI (XAI) in the presence of mHealth data? An XAI method enables a human to understand why a model makes certain predictions. Finally, which guidelines can be beneficial for the use of ML within the mHealth domain? In tinnitus research, ML discerns gender, temperature, and season-related variations among patients. In the realm of COVID-19, we collaboratively designed a COVID-19 check app for public education, incorporating EMA data to offer informative feedback on COVID-19-related matters. This thesis uses seven EMA datasets with more than 250,000 assessments. Our analyses revealed a set of challenges: App user over-representation, time gaps, identity ambiguity, and operating system specific rounding errors, among others. Our systematic review of 450 medical studies assessed prior utilization of XAI methods. Results. ML models predict gender and tinnitus perception, validating gender-linked tinnitus disparities. Using season and temperature to predict tinnitus shows the association of these variables with tinnitus. Multiple assessments of one app user can constitute a group. Neglecting these groups in data sets leads to model overfitting. In select instances, heuristics outperform ML models, highlighting the need for domain expert consultation to unveil hidden groups or find simple heuristics. Conclusion. This thesis suggests guidelines for mHealth related data analyses and improves estimates for ML performance. Close communication with medical domain experts to identify latent user subsets and incremental benefits of ML is essential.},
  subject      = {Maschinelles Lernen},
  language  = {en}
}
@phdthesis{Endres2024,
  author    = {Endres, Leo Maximilian},
  title     = {Development of multicellular \(in\) \(vitro\) models of the meningeal blood-CSF barrier to study \(Neisseria\) \(meningitidis\) infection},
  doi       = {10.25972/OPUS-34621},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346216},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Neisseria meningitidis (the meningococcus) is one of the major causes of bacterial meningitis, a life-threatening inflammation of the meninges. Traversal of the meningeal blood-cerebrospinal fluid barrier (mBCSFB), which is composed of highly specialized brain endothelial cells (BECs), and subsequent interaction with leptomeningeal cells (LMCs) are critical for disease progression. Due to the human-exclusive tropism of N. meningitidis, research on this complex host-pathogen interaction is mostly limited to in vitro studies. Previous studies have primarily used peripheral or immortalized BECs alone, which do not retain relevant barrier phenotypes in culture. To study meningococcal interaction with the mBCSFB in a physiologically more accurate context, BEC-LMC co-culture models were developed in this project using BEC-like cells derived from induced pluripotent stem cells (iBECs) or hCMEC/D3 cells in combination with LMCs derived from tumor biopsies. Distinct BEC and LMC layers as well as characteristic expression of cellular markers were observed using transmission electron microscopy (TEM) and immunofluorescence staining. Clear junctional expression of brain endothelial tight and adherens junction proteins was detected in the iBEC layer. LMC co-culture increased iBEC barrier tightness and stability over a period of seven days, as determined by sodium fluorescein (NaF) permeability and transendothelial electrical resistance (TEER). Infection experiments demonstrated comparable meningococcal adhesion and invasion of the BEC layer in all models tested, consistent with previously published data. While only few bacteria crossed the iBEC-LMC barrier initially, transmigration rates increased substantially over 24 hours, despite constant high TEER. After 24 hours of infection, deterioration of the barrier properties was observed including loss of TEER and altered expression of tight and adherens junction components. Reduced mRNA levels of ZO-1, claudin-5, and VE-cadherin were detected in BECs from all models. qPCR and siRNA knockdown data suggested that transcriptional downregulation of these genes was potentially but not solely mediated by Snail1. Immunofluorescence staining showed reduced junctional coverage of occludin, indicating N. meningitidis-induced post-transcriptional modulation of this protein, as previous studies have suggested. Together, these results suggest a potential combination of transcellular and paracellular meningococcal traversal of the mBCSFB, with the more accessible paracellular route becoming available upon barrier disruption after prolonged N. meningitidis infection. Finally, N. meningitidis induced cellular expression of pro-inflammatory cytokines and chemokines such as IL-8 in all mBCSFB models. Overall, the work described in this thesis highlights the usefulness of advanced in vitro models of the mBCSFB that mimic native physiology and exhibit relevant barrier properties to study infection with meningeal pathogens such as N. meningitidis.},
  subject      = {Bakterielle Hirnhautentz{\"u}ndung},
  language  = {en}
}
@phdthesis{Trinks2024,
  author    = {Trinks, Nora Isabel},
  title     = {Super-resolution fluorescence microscopic visualization and analysis of interactions between human immune cells and \(Aspergillus\) \(fumigatus\)},
  doi       = {10.25972/OPUS-26640},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266407},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The mold Aspergillus fumigatus (A. fumigatus) is known as human pathogen and can cause life-threatening infections in humans with a weakened immune system. This is a known complication in patients receiving glucocorticoids, e.g. after hematopoietic stem cell transplantation or solid organ transplantation. Although research in the field of immune cell/fungus interaction has discovered key strategies how immune cells fight against infectious fungi, our knowledge is still incomplete. In order to develop effective treatment options against fungal infections, a detailed understanding of their interactions is crucial. Thus, visualization of immune cell and fungus is an excellent approach to gain further knowledge. For a detailed view of such interaction processes, a high optical resolution on nanometer scale is required. There is a variety of super resolution microscopy techniques, enabling fluorescence imaging beyond the diffraction limit. This work combines the use of three complementary super resolution microscopy techniques, in order to study immune cell/fungus interaction from different points of view. Aim of this work is the introduction of the recently invented imaging technique named expansion microscopy (ExM) for the study of immune cell/fungus interactions. The core aspect of this method is the physical magnification of the specimen, which increases the distance between protein structures that are close to each other and which can therefore be imaged separately. The simultaneous magnification of primary human natural killer (NK) cells and A. fumigatus hyphae was established in this work using ExM. Reorganization of cytoskeletal components of interacting NK cells was demonstrated here, by expansion of the immunological synapse (IS), formed between NK cells and A. fumigatus. In addition, reorganization of the microtubule-organizing center (MTOC) towards fungal hyphae and an accumulation of actin at the IS has been observed. Furthermore, ExM has been used to visualize lytic granules of NK cells after degranulation. After magnification of the specimen, lysosome associated protein 1 (LAMP1) was shown to surround perforin. In absence of the plasma membrane-exposed degranulation marker LAMP1, a "ring-shaped" structure was often observed for fluorescently labeled perforin. Volume calculation of lytic granules demonstrated the benefit of ExM. Compared to pre-expansion images, analyses of post-expansion images showed two volume distributions for degranulated and non-degranulated NK cells. In addition, this work emphasizes the importance of determining the expansion factor for a structure in each species, as variations of expansion factors have been observed. This factor, as well as possible sample distortions should be considered, when ExM is used in order to analyze the interaction between two species. A second focus of this work is the visualization of a chimeric antigen receptor (CAR), targeting an epitope on the cell wall of A. fumigatus. Structured illumination microscopy (SIM) revealed that the CAR is part of the immunological synapse of primary human CAR T cells and CAR-NK-92 cells. At the interaction site, an accumulation of the CAR was observed, as well as the presence of perforin. CAR accumulation at fungal hyphae was further demonstrated by automated live cell imaging of interacting CAR-NK-92 cells, expressing a fluorescent fusion protein. Additionally, the use of direct stochastic optical reconstruction microscopy (dSTORM) gave first insights in CAR expression levels on the basal membrane of CAR-NK-92 cells, with single molecule sensitivity. CAR cluster analyses displayed a heterogeneous CAR density on the basal membrane of transfected NK 92 cells. In summary, this work provides insights into the application of ExM for studying the interaction of primary human NK cells and A. fumigatus for the first time. Furthermore, this thesis presents first insights regarding the characterization of an A. fumigatus-targeting CAR, by applying super-resolution fluorescence microscopy, like SIM and dSTORM.},
  subject      = {Mikroskopie},
  language  = {en}
}
@phdthesis{Dehmer2024,
  author    = {Dehmer, Markus},
  title     = {A novel USP11-TCEAL1-mediated mechanism protects transcriptional elongation by RNA Polymerase II},
  doi       = {10.25972/OPUS-36054},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-360544},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Deregulated expression of MYC oncoproteins is a driving event in many human cancers. Therefore, understanding and targeting MYC protein-driven mechanisms in tumor biology remain a major challenge. Oncogenic transcription in MYCN-amplified neuroblastoma leads to the formation of the MYCN-BRCA1-USP11 complex that terminates transcription by evicting stalling RNAPII from chromatin. This reduces cellular stress and allows reinitiation of new rounds of transcription. Basically, tumors with amplified MYC genes have a high demand on well orchestration of transcriptional processes-dependent and independent from MYC proteins functions in gene regulation. To date, the cooperation between promoter-proximal termination and transcriptional elongation in cancer cells remains still incomplete in its understanding. In this study the putative role of the dubiquitinase Ubiquitin Specific Protease 11 (USP11) in transcription regulation was further investigated. First, several USP11 interaction partners involved in transcriptional regulation in neuroblastoma cancer cells were identified. In particular, the transcription elongation factor A like 1 (TCEAL1) protein, which assists USP11 to engage protein-protein interactions in a MYCN-dependent manner, was characterized. The data clearly show that TCEAL1 acts as a pro-transcriptional factor for RNA polymerase II (RNAPII)-medi- ated transcription. In detail, TCEAL1 controls the transcription factor S-II (TFIIS), a factor that assists RNAPII to escape from paused sites. The findings claim that TCEAL1 outcompetes the transcription elongation factor TFIIS in a non-catalytic manner on chromatin of highly expressed genes. This is reasoned by the need regulating TFIIS function in transcription. TCEAL1 equili- brates excessive backtracking and premature termination of transcription caused by TFIIS. Collectively, the work shed light on the stoichiometric control of TFIIS demand in transcriptional regulation via the USP11-TCEAL1-USP7 complex. This complex protects RNAPII from TFIIS-mediated termination helping to regulate productive transcription of highly active genes in neuroblastoma.},
  subject      = {Transkription},
  language  = {en}
}
@phdthesis{Zhang2024,
  author    = {Zhang, Tengyu},
  title     = {Development of Modified polylysine based antibody conjugated nanoparticles with tumor-restricted, FcγR-independent stimulatory activity by targeting Fn14},
  doi       = {10.25972/OPUS-35865},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358650},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {In this study, we developed an innovative nanoparticle formulation to facilitate the delivery of antitumor antibodies to tumor sites. The study commenced with the utilization of 13 bispecific antibody fusion proteins, which targeted the Fn14 receptor, thereby validating the pivotal role of crosslinking in Fn14 receptor activation. Subsequently, gold nanoparticles were activated using COOH-PEG-SH in combination with EDC/NHS, and subsequently conjugated with two Fn14-targeting antibodies, PDL192 and 5B6. Following this, a pH-sensitive shell was generated on the outer layer of the antibody-coupled gold nanoparticles through the application of chemically modified polylysine. The resultant complexes, termed MPL-antibody-AuNP, demonstrated a release profile reminiscent of the tumor microenvironment (TME). Notably, these complexes released antibody-AuNPs only in slightly acidic conditions while remaining intact in neutral or basic environments. Functionality analysis further affirmed the pH-sensitive property of MPL-antibody-AuNPs, demonstrating that the antibodies only initiated potent Fn14 activation in slightly acidic environments. This formulation holds potential for applicability to antibodies or ligands targeting the 80 TNFRSF family, given that gold nanoparticles successfully served as platforms for antibody crosslinking, thereby transforming these antibodies into potent agonists. Moreover, the TME disintegration profile of MPL mitigates the potential cytotoxic effects of antibodies, thereby circumventing associated adverse side effects. This study not only showcases the potential of nanoparticle formulations in targeted therapy, but also provides a solid foundation for further investigations on their clinical application in the context of targeting category II TNFRSF receptors with antibodies or ligands.},
  subject      = {Immuntherapie},
  language  = {en}
}
@phdthesis{Gronemeyer2024,
  author    = {Gronemeyer, Karen},
  title     = {Kardiovaskul{\"a}re und renale Komorbidit{\"a}ten in Zusammenhang mit chronischem Hypoparathyreoidismus},
  doi       = {10.25972/OPUS-36069},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-360693},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Der cHPT ist eine seltene Erkrankung, die durch zu niedriges Kalzium im Serum aufgrund einer zu geringen PTH-Sekretion {\"u}ber 6 Monate charakterisiert ist. Auch bei Patienten mit einem gut kontrollierten cHPT treten Komorbidit{\"a}ten und Langzeitkomplikationen auf, die jedoch bisher kaum in prospektiven Studien untersucht wurden. Ziel dieser Arbeit war es daher, im Rahmen einer systematischen und prospektiv erfassten Studie das Auftreten kardiovaskul{\"a}rer und renaler Komorbidit{\"a}ten bei Patienten mit cHPT zu untersuchen und m{\"o}gliche Pr{\"a}diktoren f{\"u}r diese zu ermitteln. Außerdem erfolgte ein Vergleich mit gematchten Kontrollgruppen der deutschen Normalbev{\"o}lkerung mithilfe der SHIP-TREND Studie. Patienten mit cHPT zeigten eine signifikant h{\"o}here QTc-Zeit, eine h{\"o}here Pr{\"a}valenz f{\"u}r QTc-Zeit-Verl{\"a}ngerung und signifikant h{\"o}here systolische und diastolische Blutdruckwerte trotz tendenziell, jedoch nicht signifikant, h{\"a}ufigerer Einnahme antihypertensiver Medikamente. In der Echokardiographie lagen eine geringere linksventrikul{\"a}re Masse, eine geringere Pr{\"a}valenz f{\"u}r linksventrikul{\"a}re Hypertrophie und signifikant h{\"a}ufiger Klappenstenosen vor. Eine renale Insuffizienz lag mit 21\% der Patienten mit cHPT signifikant h{\"a}ufiger als bei gesunden Kontrollpersonen vor. Die Pr{\"a}valenz renaler Kalzifikationen betrug 9,6\%. M{\"o}gliche Risikofaktoren f{\"u}r das Auftreten kardiovaskul{\"a}rer und renaler Komorbidit{\"a}ten bei cHPT sind weiterhin unklar. In dieser Studie zeigte sich eine m{\"o}gliche Assoziation zwischen den Elektrolytst{\"o}rungen wie Hyperphosphat{\"a}mie und Hypomagnesi{\"a}mie, der Hyperkalziurie und dem PTH-Mangel mit valvul{\"a}ren, vaskul{\"a}ren und renalen Kalzifikationen sowie den Blutdruckwerten und der Nierenfunktion. Demnach erscheint eine {\"U}berwachung der Serumelektrolyte sowie der Kalziumausscheidung im Urin notwendig und essenziell. Auch die Bedeutung der PTH-Ersatztherapie ist weiterhin im Hinblick auf die Pr{\"a}vention kardiovaskul{\"a}rer und renaler Erkrankungen unklar.},
  subject      = {Hypoparathyreoidismus},
  language  = {de}
}
@phdthesis{Schwebs2024,
  author    = {Schwebs, Marie},
  title     = {Structure and dynamics of the plasma membrane: a single-molecule study in \(Trypanosoma\) \(brucei\)},
  doi       = {10.25972/OPUS-27569},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275699},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The unicellular, flagellated parasite Trypanosoma brucei is the causative agent of human African sleeping sickness and nagana in livestock. In the last decades, it has become an established eukaryotic model organism in the field of biology, as well as in the interdisciplinary field of biophysics. For instance, the dense variant surface glycoprotein (VSG) coat offers the possibility to study the dynamics of GPI-anchored proteins in the plasma membrane of living cells. The fluidity of the VSG coat is not only an interesting object of study for its own sake, but is critically important for the survival of the parasite in the mammalian host. In order to maintain the integrity of the coat, the entire VSG coat is recycled within a few minutes. This is surprisingly fast for a purely diffusive process with the flagellar pocket (FP) as the sole site for endo- and exocytosis. Previous studies characterising VSG dynamics using FRAP reported diffusion coefficients that were not sufficient to to enable fast turnover based on passive VSG randomisation on the trypanosome surface. In this thesis, live-cell single-molecule fluorescence microscopy (SMFM) was employed to elucidate whether VSG diffusion coefficients were priorly underestimated or whether directed forces could be involved to bias VSGs towards the entrance of the FP. Embedding the highly motile trypanosomes in thermo-stable hydrogels facilitated the investigation of VSG dynamics on living trypanosomes at the mammalian host's temperature of 37°C. To allow for a spatial correlation of the VSG dynamics to the FP entrance, a cell line was employed harbouring a fluorescently labelled structure as a reference. Sequential two-colour SMFM was then established to allow for recording and registration of the dynamic and static single-molecule information. In order to characterise VSG dynamics, an algorithm to obtain reliable information from short trajectories was adapted (shortTrAn). It allowed for the quantification of the local dynamics in two distinct scenarios: diffusion and directed motion. The adaptation of the algorithm to the VSG data sets required the introduction of an additional projection filter. The algorithm was further extended to take into account the localisation errors inherent to single-particle tracking. The results of the quantification of diffusion and directed motion were presented in maps of the trypanosome surface, including an outline generated from a super-resolved static structure as a reference. Information on diffusion was displayed in one map, an ellipse plot. The colour code represented the local diffusion coefficient, while the shape of the ellipses provided an indication of the diffusion behaviour (aniso- or isotropic diffusion). The eccentricity of the ellipses was used to quantify deviations from isotropic diffusion. Information on directed motion was shown in three maps: A velocity map, representing the amplitude of the local velocities in a colour code. A quiver plot, illustrating the orientation of directed motion, and a third map which indicated the relative standard error of the local velocities colour-coded. Finally, a guideline based on random walk simulations was used to identify which of the two motion scenarios dominated locally. Application of the guideline to the VSG dynamics analysed by shortTrAn yielded supermaps that showed the locally dominant motion mode colour-coded. I found that VSG dynamics are dominated by diffusion, but several times faster than previously determined. The diffusion behaviour was additionally characterised by spatial heterogeneity. Moreover, isolated regions exhibiting the characteristics of round and elongated traps were observed on the cell surface. Additionally, VSG dynamics were studied with respect to the entrance of the FP. VSG dynamics in this region displayed similar characteristics compared to the remainder of the cell surface and forces biasing VSGs into the FP were not found. Furthermore, I investigated a potential interference of the attachment of the cytoskeleton to the plasma membrane with the dynamics of VSGs which are anchored to the outer leaflet of the membrane. Preliminary experiments were conducted on osmotically swollen trypanosomes and trypanosomes depleted for a microtubule-associated protein anchoring the subpellicular microtubule cytoskeleton to the plasma membrane. The measurements revealed a trend that detachment of the cytoskeleton could be associated with a reduction in the VSG diffusion coefficient and a loss of elongated traps. The latter could be an indication that these isolated regions were caused by underlying structures associated with the cytoskeleton. The measurements on cells with an intact cytoskeleton were complemented by random walk simulations of VSG dynamics with the newly determined diffusion coefficient on long time scales not accessible in experiments. Simulations showed that passive VSG randomisation is fast enough to allow for a turnover of the full VSG coat within a few minutes. According to an estimate based on the known rate of endocytosis and the newly determined VSG diffusion coefficient, the majority of exocytosed VSGs could escape from the FP to the cell surface without being immediately re-endocytosed.},
  subject      = {Trypanosoma brucei},
  language  = {en}
}
@phdthesis{Schlesinger2024,
  author    = {Schlesinger, Tobias},
  title     = {Autolog zellbesiedelte Matrix zum Verschluss gastraler Inzisionen: Eine Machbarkeitsstudie im Schweinemodell},
  doi       = {10.25972/OPUS-30583},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305832},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Einleitung: Strukturelle Defekte der gastrointestinalen Hohlorgane stellen ein allgegen-w{\"a}rtiges Problem im klinischen Alltag dar. Sie entstehen meist auf dem Boden einer ent-z{\"u}ndlichen oder tumor{\"o}sen Grunderkrankung und k{\"o}nnen außerdem traumatisch sowie durch medizinische Eingriffe hervorgerufen werden. In der Folge kommt es zur Kontami-nation des umliegenden Gewebes mit Magen- bzw. Darminhalt, wodurch delet{\"a}re Folgen wie eine systemische Infektion, also eine Sepsis mit Multiorganversagen drohen k{\"o}nnen. Vor diesem Hintergrund sind gastrointestinale Defekte immer als potenziell lebensbedroh-lich f{\"u}r den Patienten zu betrachten. Die ad{\"a}quate und kausale Behandlung erfolgt je nach {\"A}tiologie und Zustand des Patienten durch eine Operation oder eine endoskopische Inter-vention. Hierzu stehen zahlreiche etablierte, operative und interventionelle Therapieme-thoden zur Verf{\"u}gung. In manchen F{\"a}llen stoßen die etablierten Techniken jedoch an ihre Grenzen. Bei Patienten mit schwerwiegenden Komorbidit{\"a}ten oder im Rahmen neuer me-dizinischer Verfahren sind Innovationen gefragt. Die Grundidee der vorliegenden Arbeit ist die Entwicklung einer biotechnologischen Therapieoption zur Versorgung gastrointesti-naler Hohlorganperforationen. Methoden: Zur Durchf{\"u}hrung einer Machbarkeitsstudie wurden zehn G{\"o}ttinger Mi-nischweine in zwei Gruppen mit jeweils 5 Tieren aufgeteilt. Den Tieren der Experimental-gruppe wurden Hautbiopsien entnommen und daraus Fibroblasten isoliert, welche vo-r{\"u}bergehend konserviert wurden. Unter Verwendung von azellularisiertem Schweinedarm erfolgte die Herstellung von Implantaten nach den Prinzipien des Tissue Engineerings. Die Tiere beider Gruppen wurden einer Minilaparotomie und einer ca. 3cm-Inzision der Ma-genvorderwand unterzogen. Die anschließende Versorgung wurde in der Experimental-gruppe durch Implantation der neuartigen Konstrukte erzielt. In der Kontrollgruppe wur-de im Sinne des Goldstandards eine konventionelle Naht durchgef{\"u}hrt. Anschließend wurden die Tiere f{\"u}r vier Wochen beobachtet. Eine bzw. zwei Wochen nach dem pri-m{\"a}ren Eingriff wurde bei allen Tieren beider Gruppen eine Laparoskopie bzw. Gastrosko-pie durchgef{\"u}hrt. Am Ende der klinischen Observationsphase wurden die Versuchstiere get{\"o}tet und die entsprechenden Magenareale zur histologischen Untersuchung explantiert. Ergebnisse: Die Herstellung der Implantate konnte auf der Basis standardisierter zellbio-logischer Methoden problemlos etabliert werden. Alle Tiere beider Gruppen {\"u}berlebten den Prim{\"a}reingriff sowie das vierw{\"o}chige Nachbeobachtungsintervall und zeigten dabei keine klinischen Zeichen m{\"o}glicher Komplikationen. Die durchgef{\"u}hrten Laparoskopien und Gastroskopien ergaben bei keinem der Tiere Hinweise auf Leckagen oder lokale Infek-tionsprozesse. Die histologische Aufarbeitung zeigte im Bereich des urspr{\"u}nglichen De-fekts eine bindegewebige {\"U}berbr{\"u}ckung sowie ein beginnendes Remodeling der Magen-schleimhaut in beiden Gruppen. Schlussfolgerungen: Durch die Verkn{\"u}pfung von Einzelprozessen der Zellkultur und dem Großtier-OP konnte ein neues Verfahren zum Verschluss gastrointestinaler Defekt erfolgreich demonstriert und etabliert werden. Das Projekt konnte reibungslos durchge-f{\"u}hrt werden und lieferte Ergebnisse, die dem Goldstandard nicht unterlegen waren. Auf-grund der kleinen Fallzahl und weiterer methodischer Limitationen sind jedoch nur einge-schr{\"a}nkt Schlussfolgerungen m{\"o}glich, weshalb die Durchf{\"u}hrung gr{\"o}ßerer und gut geplan-ter Studien notwendig ist. Die Erkenntnisse dieser Pilotstudie liefern eine solide Basis f{\"u}r die Planung weiterf{\"u}hrender Untersuchungen.},
  subject      = {Magenkrankheit},
  language  = {de}
}
@phdthesis{Bieniussa2024,
  author    = {Bieniussa, Linda Ilse},
  title     = {Different effects of conditional Knock-Out of Stat3 on the sensory epithelium of the Organ of Corti},
  doi       = {10.25972/OPUS-35143},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351434},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Die Cochlea von S{\"a}ugetieren nimmt Schall als Reaktion auf Vibrationen an frequenzabh{\"a}ngigen Positionen entlang des Cochlea-Kanals wahr. Die sensorischen {\"a}ußeren Haarzellen, die von St{\"u}tzzellen umgeben sind, wirken als Signalverst{\"a}rker, indem sie ihre Zelll{\"a}nge ver{\"a}ndern k{\"o}nnen. Dies wird als Elektromotilit{\"a}t bezeichnet. Um eine korrekte elektrische {\"U}bertragung bei mechanischen Kr{\"a}ften zu gew{\"a}hrleisten, ist ein gewisser Widerstand des sensorischen Epithels eine Voraussetzung f{\"u}r die fehlerfreie Weiterleitung von H{\"o}rinformationen. Dieser Widerstand wird durch Mikrotubuli und deren posttranslationalen Modifikationen in den St{\"u}tzzellen des sensorischen Epithels der Cochlea gew{\"a}hrleistet. Stat3 ist ein Transkriptionsfaktor, der an verschiedenen Phosphorylierungsstellen, sowie je nach Zelltyp und aktiviertem Signalweg an vielen zellul{\"a}ren Prozessen wie Differenzierung, Entz{\"u}ndung, Zell{\"u}berleben und Mikrotubuli-Dynamik beteiligt ist. W{\"a}hrend Stat3 ein breites Spektrum an intrazellul{\"a}ren Funktionen hat, stellte sich die Frage, wie und ob Stat3 in den Zellen des Cortischen Organ einen Einfluss auf den H{\"o}rprozess hat. Um dies zu testen, wurde das Cre/loxp-System verwendet, um Stat3 in den {\"a}ußeren Haarzellen oder den St{\"u}tzzellen entweder vor oder nach H{\"o}rbeginn von M{\"a}usen konditional auszuschalten. Um das H{\"o}rverm{\"o}gen zu erfassen, wurden DPOAE- und ABR-Messungen durchgef{\"u}hrt, w{\"a}hrend molekulare und morphologische Untersuchungen mittels Sequenzierung und Immunhistochemie durchgef{\"u}hrt wurden. Eine konditioneller Knock-Out von Stat3 vor und nach dem Beginn des H{\"o}rens in {\"a}ußeren Haarzellen f{\"u}hrt zu leichten H{\"o}rsch{\"a}den, w{\"a}hrend Synapsen, Nervenfasern und Mitochondrien nicht betroffen waren. Die Analyse der Sequenzierung von {\"a}ußeren Haarzellen aus M{\"a}usen mit konditionellem Knock-Out vor dem Beginn des H{\"o}rens ergab eine St{\"o}rung der zellul{\"a}ren Hom{\"o}ostase und der extrazellul{\"a}ren Signale. Ein konditioneller Knock-Out von Stat3 in den {\"a}ußeren Haarzellen nach Beginn des H{\"o}rens f{\"u}hrte zu einem fr{\"u}h-entz{\"u}ndlichen Signalweg mit erh{\"o}hter Zytokinproduktion und der Hochregulierung des NF-κB-Wegs. In den St{\"u}tzzellen f{\"u}hrte ein kondioneller Knock-Out von Stat3 nur nach dem Beginn des H{\"o}rens zu einer H{\"o}rbeeintr{\"a}chtigung. Synapsen, Nervensoma und -fasern waren jedoch von einem konditionellen Knock-Out von Stat3 in St{\"u}tzzellen nicht betroffen. Dennoch war die detyronisierte Modifikation der Mikrotubuli ver{\"a}ndert, was zu einer Instabilit{\"a}t der St{\"u}tzzellen, insbesondere der Phalangealforts{\"a}tze, f{\"u}hrte, was wiederum zu einer Instabilit{\"a}t des Epithels w{\"a}hrend des H{\"o}rvorgangs f{\"u}hrte. Zusammenfassend l{\"a}sst sich sagen, dass ein konditioneller Knock-Out von Stat3 in Zellen des Cortischen Organs zu einer H{\"o}rst{\"o}rung f{\"u}hrte. W{\"a}hrend ein konditioneller Knock-Out in {\"a}ußeren Haarzellen eine erh{\"o}hte Zytokinproduktion zur Folge hatte, verloren die St{\"u}tzzellen ihre Zellstabilit{\"a}t aufgrund einer verminderten detyronisierten Modifikation der Mikrotubuli. Insgesamt deuten die Ergebnisse darauf hin, dass Stat3 ein wichtiges Protein f{\"u}r die H{\"o}rleistung ist. Es sind jedoch weitere Untersuchungen des molekularen Mechanismus erforderlich, um die Rolle von Stat3 in den Zellen des Corti-Organs zu verstehen.},
  subject      = {Audiologie},
  language  = {en}
}
@phdthesis{Prager2024,
  author    = {Prager, Lisa},
  title     = {Spatiotemporale Entwicklung der Immunantwort nach Pneumovirus-Infektion},
  doi       = {10.25972/OPUS-17988},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179885},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Das humane Respiratorische Synzytial-Virus (RSV) gilt als wichtiger Krankheitserreger f{\"u}r S{\"a}uglinge und Kleinkinder sowie f{\"u}r {\"a}ltere Personen und immunsupprimierte Patienten. Krankheitssymptome und teils schwerwiegende Verl{\"a}ufe werden dabei eher einer Immunpathogenese zugeschrieben als der Virusvermehrung selbst. Aus Ermangelung eines ad{\"a}quaten Tiermodells wird h{\"a}ufig das RSV-verwandte Pneumonievirus der Maus (PVM) als Ersatzmodell f{\"u}r schwere Pneumovirusinfektionen verwendet. In dieser Dissertation wurde zum einen die spatiotemporale Rekrutierung von zellul{\"a}ren Komponenten der angeborenen und adaptiven Immunantwort im Verh{\"a}ltnis zum Verlauf einer PVM-Infektion in immunkompetenten und immunsupprimierten Wirten untersucht. Zum anderen wurde die Pathogenese einer Pneumovirusinfektion anhand des PVM-Modells in Mauslinien mit definierten Immundefizienzen analysiert. Wie bereits in einer fr{\"u}heren Untersuchung ermittelt, korrelierte die Rekrutierung von CD8+ T-Lymphozyten mit der Viruseliminierung (Frey et al., 2008). B-Lymphozyten wurden aktiv in das Lungengewebe PVM infizierter C57BL/6-M{\"a}use rekrutiert, wobei sie perivaskul{\"a}re und peribronchiale Foki, die ebenfalls CD4+ T-Zellen enthielten, bildeten. Dies k{\"o}nnte auf die Bildung terti{\"a}rer lymphoider Gewebe hindeuten. Die Rekrutierung von Zellen der angeborenen Immunantwort (NK-Zellen, neutrophile Granulozyten) geschah parallel bzw. verz{\"o}gert zur Virusvermehrung und damit eher sp{\"a}t w{\"a}hrend der Infektion. Die Rekrutierung von eosinophilen Granulozyten erfolgte erst in der Eliminationsphase der PVM-Infektion zusammen mit CD4+-T-Zellen. Zus{\"a}tzlich wurde ermittelt, dass Alveolarmakrophagen (AMΦ) in vivo mit PVM infiziert und dabei transient depletiert wurden. Die Depletion der AMΦ schien dabei nicht durch Lymphozytenpopulationen zu erfolgen. Die Charakterisierung der PVM-Infektion bei M{\"a}usen mit definierten Immundefizienzen ergab, dass B-Lymphozyten zur partiellen Viruskontrolle in T-Zell-defizienten M{\"a}usen beitragen und dadurch zur Protektion vor letalen Verl{\"a}ufen bei diesen M{\"a}usen f{\"u}hren. Die Letalit{\"a}t bei diesen M{\"a}usen, insbesondere in Abwesenheit von funktionellen B-Zellen, war mit Kontrollverlust {\"u}ber die Virusvermehrung assoziiert. B-Lymphozyten 2 wurden effizient in das infizierte Lungengewebe von T-Zell-defizienten M{\"a}usen rekrutiert. Das Serum T-Zell-defizienter M{\"a}use wies eine PVM-neutralisierende Aktivit{\"a}t auf, die mit dem Erscheinen PVM-spezifischer IgM-Antik{\"o}rper, T-Zell-unabh{\"a}ngig synthetisiert, korrelierte. IgG-Antik{\"o}rper waren jedoch zu diesen Zeitpunkten (14 d.p.i.) nicht nachweisbar. Dies wurde m{\"o}glicherweise durch unvollst{\"a}ndigen oder verz{\"o}gerten Reifungsprozess von B-Lymphozyten in T-Zell-defizienten M{\"a}usen reflektiert, da verschiedene Antik{\"o}rperklassen, wie IgM- und IgG-Antik{\"o}rper zeitgleich exprimiert wurden. Eine hohe Heterogenit{\"a}t bzgl. der klinischen Symptome und dem Ausgang der Infektion schien außerdem ein Kennzeichen von PVM-Infektionen unter bestimmten Immundefizienzen zu sein. Der adoptive B-Zell-Transfer in B6.Rag1-/--M{\"a}use ver{\"a}ndert die Krankheitsverl{\"a}ufe nach PVM-Infektion, da einige B-Zell-transplantierte M{\"a}use ohne klinische Symptome zu zeigen {\"u}berlebten und andere zwar Gewicht verloren und die Versuchsabbruchkriterien erreichten, aber die Heterogenit{\"a}t der Krankheitsverl{\"a}ufe reduziert war. Adoptiv transferierte B-Lymphozyten wurden außerdem in lymphatische Organe und in infiziertes Lungengewebe rekrutiert und waren in der Lage zu Plasmazellen zu reifen. Es gibt somit erste Indizien, dass B-Zellen zu einem Schutz bei einer akuten PVM-Infektion beitragen.},
  subject      = {RS-Virus},
  language  = {de}
}
@phdthesis{Stuerzebecher2024,
  author    = {St{\"u}rzebecher, Paulina Elena},
  title     = {Die Rolle von LASP1 in der Pathogenese der Atherosklerose im murinen Modell},
  doi       = {10.25972/OPUS-23935},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239353},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Das regulatorische Ger{\"u}st-Protein LASP1, welches aus der Krebsforschung bekannt ist, wurde 2012 in humanen Makrophagen, den Protagonisten der Atherosklerose nachgewiesen. LASP1 ist durch seine Lokalisation an dynamischen Aktinskelettkonstruktionen (vgl. Invadopodien, Podosomen), nachweislich an Zellmigration, Proliferation und Invasionsf{\"a}higkeit bestimmter Tumorzellen beteiligt. Aufgrund einer großen Schnittmenge der Entstehungsmechanismen und zugrundeliegenden Signalwegen von Krebserkrankungen und Atherosklerose wurde LASP1 im Zusammenhang der Atherosklerose untersucht. In einem 16 Wochen Hochfettdi{\"a}tversuch zeigten LASP1.Ldlr-/--M{\"a}use mehr atherosklerotische L{\"a}sionen in der Gesamtaorta als Ldlr-/--Tiere, was eine athero-protektive Rolle von LASP1 nahelegt. Passend hierzu f{\"u}hrte Stimulation mit oxLDL in Makrophagen zu einer Hochregulation von LASP1. Zus{\"a}tzlich internalisierten LASP1-/--Makrophagen signifikant mehr oxLDL im Vergleich zu LASP1-exprimierenden Zellen. Analog zu den Daten aus der Krebsforschung konnte eine reduzierte endotheliale Adh{\"a}sion sowie chemotaktische Migration von Ldlr.LASP1-/--Monozyten im Vergleich zu Ldlr-/-- Monozyten festgestellt werden. Dies ließe isoliert betrachtet eine pro-atherogene Rolle von LASP1 vermuten. Ein Nachweis von LASP1 im Zellkern von BMDMs konnte, zus{\"a}tzlich zum fehlenden Shuttelproteinpartner ZO-2, nicht erbracht werden. Die Interaktion von LASP1 mit Transkriptionsfaktoren scheint daher unwahrscheinlich. Kongruent mit diesen Ergebnissen zeigte sich keine Ver{\"a}nderung der Transkription, der Proteinexpression sowie Sekretion von TNF! und ADAM17 durch den LASP1-KO. Insgesamt kommt LASP1 eine zweifellos komplexe Rolle in der Atherogenese zu. Die Ergebnisse der HFD-Versuche legen nahe, dass die prim{\"a}r anti-atherosklerotischen Einfl{\"u}sse von LASP1 in vivo gegen{\"u}ber den eher pro-atherosklerotischen Effekten des Proteins in vitro {\"u}berwiegen.},
  subject      = {Arteriosklerose},
  language  = {de}
}
@phdthesis{Pollerhoff2024,
  author    = {Pollerhoff, Lena Katharina},
  title     = {Age differences in prosociality across the adult lifespan: Insights from self-reports, experimental paradigms, and meta-analyses},
  doi       = {10.25972/OPUS-35944},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-359445},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Human prosociality, encompassing generosity, cooperation, and volunteering, holds a vital role in our daily lives. Over the last decades, the question of whether prosociality undergoes changes over the adult lifespan has gained increased research attention. Earlier studies suggested increased prosociality in older compared to younger individuals. However, recent meta-analyses revealed that this age effect might be heterogeneous and modest. Moreover, the contributing factors and mechanisms behind these age-related variations remain to be identified. To unravel age-related differences in prosociality, the first study of this dissertation employed a meta-analytical approach to summarize existing findings and provide insight into their heterogeneity by exploring linear and quadratic age effects on self-reported and behavioral prosociality. Additionally, two empirical research studies investigated whether these age-related differences in prosociality were observed in real life, assessed through ecological momentary assessment (Study 2), and in a controlled laboratory setting by applying a modified dictator game (Study 3). Throughout these three studies, potential underlying behavioral and computational mechanisms were explored. The outcome of the meta-analysis (Study 1) revealed small linear age effects on prosociality and significant age group differences between younger and older adults, with higher levels of prosociality in older adults. Explorative evidence emerged in favor of a quadratic age effect on behavioral prosociality, indicating the highest levels in midlife. Additionally, heightened prosocial behavior among middle-aged adults was observed compared to younger adults, whereas no significant differences in prosocial behavior were noted between middle-aged and older adults. Situational and contextual features, such as the setting of the study and specific paradigm characteristics, moderated the age-prosociality relationship, highlighting the importance of the (social) context when studying prosociality. For Study 2, no significant age effect on real-life prosocial behavior was observed. However, evidence for a significant linear and quadratic age effect on experiencing empathy in real life emerged, indicating a midlife peak. Additionally, across all age groups, the link between an opportunity to empathize and age significantly predicted real-life prosocial behavior. This effect, indicating higher levels of prosocial behavior when there was a situation possibly evoking empathy, was most pronounced in midlife. Study 3 presented age differences in how older and younger adults integrate values related to monetary gains for self and others to make a potential prosocial decision. Younger individuals effectively combined both values in a multiplicative fashion, enhancing decision-making efficiency. Older adults showed an additive effect of values for self and other and displayed increased decision-making efficiency when considering the values separately. However, among older adults, individuals with better inhibitory control were better able to integrate information about both values in their decisions. Taken together, the findings of this dissertation offer new insights into the multi-faceted nature of prosociality across adulthood and the mechanisms that help explain these age-related disparities. While this dissertation observed increasing prosociality across the adult lifespan, it also questions the assumption that older adults are inherently more prosocial. The studies highlight midlife as a potential peak period in social development but also emphasize the importance of the (social) context and that different operationalizations might capture distinct facets of prosociality. This underpins the need for a comprehensive framework to understand age effects of prosociality better and guide potential interventions.},
  subject      = {Altersunterschied},
  language  = {en}
}
@phdthesis{Zillig2024,
  author    = {Zillig, Anna-Lena Christina},
  title     = {Einfluss von Sicherheit auf die Schmerzverarbeitung},
  doi       = {10.25972/OPUS-35928},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-359282},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Im Rahmen des interdisziplin{\"a}ren Promotionsschwerpunkts Resilienzfaktoren der Schmerzverarbeitung des evangelischen Studienwerks in Zusammenarbeit mit der Julius-Maximilians-Universit{\"a}t W{\"u}rzburg und der Otto-Friedrich-Universit{\"a}t Bamberg untersuche ich in diesem Promotionsprojekt den Einfluss von Sicherheit auf die Schmerzverarbeitung. Es ist bekannt, dass die Schmerzverarbeitung durch Emotionen moduliert werden kann. Man geht davon aus, dass negative Emotionen den Schmerz in der Regel verst{\"a}rken, w{\"a}hrend positive Emotionen zu einer Schmerzreduktion f{\"u}hren. Fr{\"u}here Studien fanden heraus, dass die Erwartung eines aversiven Ereignisses zu Bedrohung und st{\"a}rkeren Schmerzen f{\"u}hrt. Es stellt sich die Frage, ob das Gegenteil von Bedrohung, n{\"a}mlich Sicherheit, zu einer Verringerung der Schmerzen f{\"u}hren kann. Um diese Hypothese zu untersuchen, habe ich drei Experimente an gesunden ProbandInnen durchgef{\"u}hrt.},
  subject      = {Sicherheit},
  language  = {de}
}
@phdthesis{Krampert2024,
  author    = {Krampert, Laura},
  title     = {Dynamics of cardiac neutrophil diversity in murine myocardial infarction},
  doi       = {10.25972/OPUS-34957},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349576},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {After myocardial infarction, an inflammatory response is induced characterized by a sterile inflammation, followed by a reparative phase in order to induce cardiac healing. Neutrophils are the first immune cells that enter the ischemic tissue. Neutrophils have various functions in the ischemic heart, such as phagocytosis, production of reactive oxygen species or release of granule components. These functions can not only directly damage cardiac tissue, but are also necessary for initiating reparative effects in post-ischemic healing, indicating a dual role of neutrophils in cardiac healing after infarction. In recent years, evidence has been growing that neutrophils show phenotypic and functional differences in distinct homeostatic and pathogenic settings. Preliminary data of my working group using single-cell RNA-sequencing revealed the time- dependent heterogeneity of neutrophils, with different populations showing distinct gene expression profiles in ischemic hearts of mice, including the time-dependent appearance of a SiglecFhigh neutrophil population. To better understand the dynamics of neutrophil heterogeneity in the ischemic heart, my work aimed to validate previous findings at the protein level, as well as to investigate whether the distinct neutrophil populations show functional differences. Furthermore, in vivo depletion experiments were performed in order to modulate circulating neutrophil levels. Hearts, blood, bone marrow and spleens were processed and analyzed from mice after 1 day and 3 days after the onset of cardiac ischemia and analyzed using flow cytometry. Results showed that the majority of cardiac neutrophils isolated at day 3 after myocardial infarction were SiglecFhigh, whereas nearly no SiglecFhigh neutrophils could be isolated from ischemic hearts at day 1 after myocardial infarction. No SiglecFhigh neutrophils could be found in the blood, spleen and bone marrow either after 1 day or 3 days after myocardial infarction, indicating that the SiglecFhigh state of neutrophils is unique to the ischemic cardiac tissue. When I compared SiglecFhigh and SiglecFlow neutrophils regarding their phagocytosis activity and ROS production, SiglecFhigh neutrophils showed a higher phagocytosis ability than their SiglecFlow counterparts, as well as higher ROS production capacity. In vivo depletion experiments could not achieve successful and efficient depletion of cardiac neutrophils either 1 day or 3 days after myocardial infarction, but led to a shift of a higher percentage of SiglecFhigh expressing neutrophils in the depletion group. Bone marrow neutrophil levels only showed partial depletion at day 3 after MI. Regarding blood neutrophils, depletion efficiently reduced circulating neutrophils at both time points, 1 and 3 days after MI. To summarize, this work showed the time-dependent presence of different neutrophil states in the ischemic heart. The main population of neutrophils isolated 3 days after MI showed a high expression of SiglecF, a unique state that could not be detected at different time points or other organs. These SiglecFhigh neutrophils showed functional differences regarding their phagocytosis ability and ROS production. Further investigation is needed to reveal what role these SiglecFhigh neutrophils could play within the ischemic heart. To better target neutrophil depletion in vivo, more efficient or different anti-neutrophil strategies are needed.},
  subject      = {Neutrophiler Granulozyt},
  language  = {en}
}
@phdthesis{Aido2024,
  author    = {Aido, Ahmed},
  title     = {Development of anti-TNF antibody-gold nanoparticles (anti-TNF-AuNPs)},
  doi       = {10.25972/OPUS-34921},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349212},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Gold nanoparticles of diameter ca. 60 nm have been synthesized based on Turkevich and Frens protocols. We have demonstrated that the carboxyl-modified gold nanoparticles can be coupled covalently with antibodies (Ab) of interest using the EDC/NHS coupling procedure. Binding studies with Ab-grafted AuNPs and GpL fusion proteins proved that conjugation of AuNPs with antibodies enables immobilization of antibodies with preservation of a significant antigen binding capacity. More importantly, our findings showed that the conjugation of types of anti-TNF receptors antibodies such as anti-Fn14 antibodies (PDL192 and 5B6) (Aido et al., 2021), anti-CD40, anti-4-1BB and anti-TNFR2 with gold nanoparticles confers them with potent agonism. Thus, our results suggest that AuNPs can be utilized as a platform to immobilize anti-TNFR antibodies which, on the one hand, helps to enhance their agonistic activity in comparison to "free" inactive antibodies by mimicking the effect of cell-anchored antibodies or membrane-bound TNF ligands and, on the other hand, allows to develop new generations of drug delivery systems. These constructs are characterized with their biocompatibility and their tunable synthesis process. In a further work part, we combined the benefits of the established system of Ab-AuNPs with materials used widely in the modern biofabrication approaches such as the photo-crosslinked hydrogels, methacrylate-modified gelatin (GelMA), combined with embedded variants of human cell lines. The acquired results demonstrated clearly that the attaching of proteins like antibodies to gold nanoparticles might reduce their release rate from the crosslinked hydrogels upon the very low diffusion of gold nanoparticles from the solid constructs to the surrounding medium yielding long-term local functioning proteins-attached particles. Moreover, our finding suggests that hydrogel-embedded AuNP-immobilized antibodies, e.g. anti-TNFα-AuNPs or anti-IL1-AuNPs enable local inhibitory functions, To sum up, our results demonstrate that AuNPs can act as a platform to attach anti-TNFR antibodies to enhance their agonistic activity by resembling the output of cell-anchoring or membrane bounding. Gold nanoparticles are considered, thus, as promising tool to develop the next generation of drug delivery systems, which may contribute to cancer therapy. On top of that, the embedding of anti-inflammatory-AuNPs in the biofabricated hydrogel presents new innovative strategy of the treatment of autoinflammatory diseases.},
  subject      = {Nanopartikel},
  language  = {en}
}
@phdthesis{Hoerner2024,
  author    = {H{\"o}rner, Michaela},
  title     = {The role of inflammation in hereditary spastic paraplegia type 11},
  doi       = {10.25972/OPUS-30336},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303368},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Hereditary spastic paraplegias (HSPs) are genetically-determined, neurodegenerative disorders characterized by progressive weakness and spasticity of the lower limbs. Spastic paraplegia type 11 (SPG11) is a complicated form of HSP, which is caused by mutations in the SPG11 gene encoding spatacsin, a protein possibly involved in lysosomal reformation. Based on our previous studies demonstrating that secondary neuroinflammation can be a robust amplifier of various genetically-mediated diseases of both the central and peripheral nervous system, we here test the possibility that neuroinflammation may modify the disease outcome also in a mouse model for SPG11. Spg11-knockout (Spg11-/-) mice develop early walking pattern and behavioral abnormalities, at least partially reflecting motor, and behavioral changes typical for patients. Furthermore, we detected a progressive increase in axonal damage and axonal spheroid formation in the white and grey matter compartments of the central nervous system of Spg11-/- mice. This was accompanied by a concomitant substantial increase of secondary inflammation by cytotoxic CD8+ and CD4+ T-lymphocytes. We here provide evidence that disease-related changes can be ameliorated/delayed by the genetic deletion of the adaptive immune system. Accordingly, we provide evidence that repurposing clinically approved immunomodulators (fingolimod/FTY720 or teriflunomide), that are in use for treatment of multiple sclerosis (MS), also improve disease symptoms in mice, when administered in an early (before neural damage) or late (after/during neural damage) treatment regime. This work provides strong evidence that immunomodulation can be a therapeutic option for the still untreatable SPG11, including its typical neuropsychological features. This poses the question if inflammation is not only a disease amplifier in SPG11 but can act as a unifying factor also for other genetically mediated disorders of the CNS. If true, this may pave the way to therapeutic options in a wide range of still untreatable, primarily genetic, neurological disorders by repurposing approved immunomodulators.},
  subject      = {Entz{\"u}ndung},
  language  = {en}
}
@phdthesis{Jihyoung2024,
  author    = {Jihyoung, Choi},
  title     = {Development of an Add-On Electrode for Non-Invasive Monitoring in Bioreactor Cultures and Medical Devices},
  doi       = {10.25972/OPUS-35823},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358232},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Electrochemical impedance spectroscopy (EIS) is a valuable technique analyzing electrochemical behavior of biological systems such as electrical characterization of cells and biomolecules, drug screening, and biomaterials in biomedical field. In EIS, an alternating current (AC) power signal is applied to the biological system, and the impedance of the system is measured over a range of frequencies. In vitro culture models of endothelial or epithelial barrier tissue can be achieved by culturing barrier tissue on scaffolds made with synthetic or biological materials that provide separate compartments (apical and basal sides), allowing for further studies on drug transport. EIS is a great candidate for non-invasive and real-time monitoring of the electrical properties that correlate with barrier integrity during the tissue modeling. Although commercially available transendothelial/transepithelial electrical resistance (TEER) measurement devices are widely used, their use is particularly common in static transwell culture. EIS is considered more suitable than TEER measurement devices in bioreactor cultures that involve dynamic fluid flow to obtain accurate and reliable measurements. Furthermore, while TEER measurement devices can only assess resistance at a single frequency, EIS measurements can capture both resistance and capacitance properties of cells, providing additional information about the cellular barrier's characteristics across various frequencies. Incorporating EIS into a bioreactor system requires the careful optimization of electrode integration within the bioreactor setup and measurement parameters to ensure accurate EIS measurements. Since bioreactors vary in size and design depending on the purpose of the study, most studies have reported using an electrode system specifically designed for a particular bioreactor. The aim of this work was to produce multi-applicable electrodes and established methods for automated non-invasive and real-time monitoring using the EIS technique in bioreactor cultures. Key to the electrode material, titanium nitride (TiN) coating was fabricated on different substrates (materials and shape) using physical vapor deposition (PVD) and housed in a polydimethylsiloxane (PDMS) structure to allow the electrodes to function as independent units. Various electrode designs were evaluated for double-layer capacitance and morphology using EIS and scanning electron microscopy (SEM), respectively. The TiN-coated tube electrode was identified as the optimal choice. Furthermore, EIS measurements were performed to examine the impact of influential parameters related to culture conditions on the TiN-coated electrode system. In order to demonstrate the versatility of the electrodes, these electrodes were then integrated into in different types of perfusion bioreactors for monitoring barrier cells. Blood-brain barrier (BBB) cells were cultured in the newly developed dynamic flow bioreactor, while human umblical vascular endothelial cells (HUVECs) and Caco-2 cells were cultured in the miniature hollow fiber bioreactor (HFBR). As a result, the TiN-coated tube electrode system enabled investigation of BBB barrier integrity in long-term bioreactor culture. While EIS measurement could not detect HUVECs electrical properties in miniature HFBR culture, there was the possibility of measuring the barrier integrity of Caco-2 cells, indicating potential usefulness for evaluating their barrier function. Following the bioreactor cultures, the application of the TiN-coated tube electrode was expanded to hemofiltration, based on the hypothesis that the EIS system may be used to monitor clotting or clogging phenomena in hemofiltration. The findings suggest that the EIS monitoring system can track changes in ion concentration of blood before and after hemofiltration in real-time, which may serve as an indicator of clogging of filter membranes. Overall, our research demonstrates the potential of TiN-coated tube electrodes for sensitive and versatile non-invasive monitoring in bioreactor cultures and medical devices.},
  subject      = {Monitoring},
  language  = {en}
}
@phdthesis{HuttererneeHerzog2024,
  author    = {Hutterer, n{\´e}e Herzog, Katharina},
  title     = {Treatment-like use of discrimination training to reduce generalization of conditioned fear},
  doi       = {10.25972/OPUS-31728},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317286},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Anxiety patients overgeneralize fear, also because of an inability to perceptually discriminate threat and safety signals. Therefore, some studies have developed discrimination training that successfully reduced the occurrence of fear generalization. The present work is the first to take a treatment-like approach by using discrimination training after generalization has occurred. Therefore, two studies were conducted with healthy participants using the same fear conditioning and generalization paradigm, with two faces as conditioned stimuli (CSs), and four facial morphs between CSs as generalization stimuli (GSs). Only one face (CS+) was followed by a loud scream (unconditioned stimulus, US). In Study 1, participants underwent either fear-relevant (discriminating faces) or fear-irrelevant discrimination training (discriminating width of lines) or a non-discriminative control training between the two generalization tests, each with or without feedback (n = 20 each). Generalization of US expectancy was reduced more effectively by fear-relevant compared to fear-irrelevant discrimination training. However, neither discrimination training was more effective than non-discriminative control training. Moreover, feedback reduced generalization of US expectancy only in discrimination training. Study 2 was designed to replicate the effects of the discrimination-training conditions in a large sample (N = 244) and examine their benefits in individuals at risk for anxiety disorders. Again, feedback reduced fear generalization particularly well for US expectancy. Fear relevance was not confirmed to be particularly fear-reducing in healthy participants, but may enhance training effects in individuals at risk of anxiety disorder. In summary, this work provides evidence that existing fear generalization can be reduced by discrimination training, likely involving several (higher-level) processes besides perceptual discrimination (e.g., motivational mechanisms in feedback conditions). Its use may be promising as part of individualized therapy for patients with difficulty discriminating similar stimuli.},
  subject      = {Furcht},
  language  = {en}
}
@phdthesis{Kutschka2024,
  author    = {Kutschka, Ilona},
  title     = {Activation of the integrated stress response induces remodeling of cardiac metabolism in Barth Syndrome},
  doi       = {10.25972/OPUS-35818},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358186},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Barth Syndrome (BTHS) is an inherited X-chromosomal linked disorder, characterized by early development of cardiomyopathy, immune system defects, skeletal muscle myopathy and growth retardation. The disease displays a wide variety of symptoms including heart failure, exercise intolerance and fatigue due to the muscle weakness. The cause of the disease are mutations in the gene encoding for the mitochondrial transacylase Tafazzin (TAZ), which is important for remodeling of the phospholipid cardiolipin (CL). All mutations result in a pronounced decrease of the functional enzyme leading to an increase of monolysocardiolipin (MLCL), the precursor of mature CL, and a decrease in mature CL itself. CL is a hallmark phospholipid of mitochondrial membranes, highly enriched in the inner mitochondrial membrane (IMM). It is not only important for the formation of the cristae structures, but also for the function of different protein complexes associated with the mitochondrial membrane. Reduced levels of mature CL cause remodeling of the respiratory chain supercomplexes, impaired respiration, defects in the Krebs cycle and a loss of mitochondrial calcium uniporter (MCU) protein. The defective Ca2+ handling causes impaired redox homeostasis and energy metabolism resulting in cellular arrhythmias and defective electrical conduction. In an uncompensated situation, blunting mitochondrial Ca2+ uptake provokes increased mitochondrial emission of H2O2 during workload transitions, related to oxidation of NADPH, which is required to regenerate anti-oxidative enzymes. However, in the hearts and cardiac myocytes of mice with a global knock-down of the Taz gene (Taz-KD), no increase in mitochondrial ROS was observed, suggesting that other metabolic pathways may have compensated for reduced Krebs cycle activation. The healthy heart produces most of its energy by consuming fatty acids. In this study, the fatty acid uptake into mitochondria and their further degradation was investigated, which showed a switch of the metabolism in general in the Taz-KD mouse model. In vivo studies revealed an increase of glucose uptake into the heart and decreased fatty acid uptake and oxidation. Disturbed energy conversion resulted in activation of retrograde signaling pathways, implicating overall changes in the cell metabolism. Upregulated integrated stress response (ISR) was confirmed by increased levels of the downstream target, i.e., the activating transcription factor 4 (ATF4). A Tafazzin knockout mouse embryonal fibroblast cell model (TazKO) was used to inhibit the ISR using siRNA transfection or pharmaceutical inhibition. This verified the central role of II the ISR in regulating the metabolism in BTHS. Moreover, an increased metabolic flux into glutathione biosynthesis was observed, which supports redox homeostasis. In vivo PET-CT scans depicted elevated activity of the xCT system in the BTHS mouse heart, which transports essential amino acids for the biosynthesis of glutathione precursors. Furthermore, the stress induced signaling pathway also affected the glutamate metabolism, which fuels into the Krebs cycle via -ketoglutarate and therefore supports energy converting pathways. In summary, this thesis provides novel insights into the energy metabolism and redox homeostasis in Barth syndrome cardiomyopathy and its regulation by the integrated stress response, which plays a central role in the metabolic alterations. The aim of the thesis was to improve the understanding of these metabolic changes and to identify novel targets, which can provide new possibilities for therapeutic intervention in Barth syndrome.},
  subject      = {Herzmuskelkrankheit},
  language  = {en}
}
@phdthesis{WeigelverhHoffmann2024,
  author    = {Weigel [verh. Hoffmann], Mathis Leonard},
  title     = {Thrombozytenfunktionsanalyse als potenzielles Instrument zur Fr{\"u}herkennung von Sepsis},
  doi       = {10.25972/OPUS-35819},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358193},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Sepsis ist ein h{\"a}ufiges und akut lebensbedrohliches Syndrom, das eine Organfunktionsst{\"o}rung in Folge einer dysregulierten Immunantwort auf eine Infektion beschreibt. Eine fr{\"u}hzeitige Diagnosestellung und Therapieeinleitung sind von zentraler Bedeutung f{\"u}r das {\"U}berleben der Patient:innen. In einer Pilotstudie konnte unsere Forschungsgruppe mittels Durchflusszytometrie eine ausgepr{\"a}gte Hyporeaktivit{\"a}t der Thrombozyten bei Sepsis nachweisen, die einen potenziell neuen Biomarker zur Sepsis-Fr{\"u}herkennung darstellt. Zur Evaluation des Ausmaßes und Entstehungszeitpunktes der detektierten Thrombozytenfunktionsst{\"o}rung wurden im Rahmen der vorliegenden Arbeit zus{\"a}tzlich zu Patient:innen mit Sepsis (SOFA-Score ≥ 2; n=13) auch hospitalisierte Patient:innen mit einer Infektion ohne Sepsis (SOFA-Score < 2; n=12) rekrutiert. Beide Kohorten wurden zu zwei Zeitpunkten (t1: <24h; t2: Tag 5-7) im Krankheitsverlauf mittels Durchflusszytometrie und PFA-200 untersucht und mit einer gesunden Kontrollgruppe (n=28) verglichen. Ph{\"a}notypische Auff{\"a}lligkeiten der Thrombozyten bei Sepsis umfassten: (i) eine ver{\"a}nderte Expression verschiedener Untereinheiten des GPIb-IX-V-Rezeptorkomplexes, die auf ein verst{\"a}rktes Rezeptor-Shedding hindeutet; (ii) ein ausgepr{\"a}gtes Mepacrin-Beladungsdefizit, das auf eine zunehmend reduzierte Anzahl von δ-Granula entlang des Infektion-Sepsis Kontinuums hinweist; (iii) eine Reduktion endst{\"a}ndig gebundener Sialins{\"a}ure im Sinne einer verst{\"a}rkten Desialylierung. Die funktionelle Analyse der Thrombozyten bei Sepsis ergab bei durchflusszytometrischer Messung der Integrin αIIbβ3-Aktivierung (PAC-1-Bindung) eine ausgepr{\"a}gte generalisierte Hyporeaktivit{\"a}t gegen{\"u}ber multiplen Agonisten, die abgeschw{\"a}cht bereits bei Infektion nachweisbar war und gem{\"a}ß ROC-Analysen gut zwischen Infektion und Sepsis diskriminierte (AUC >0.80 f{\"u}r alle Agonisten). Im Gegensatz dazu zeigten Thrombozyten bei Sepsis und Analyse mittels PFA-200 unter Einfluss physiologischer Scherkr{\"a}fte eine normale bis gar beschleunigte Aggregation. Die Reaktivit{\"a}tsmessung von Thrombozyten mittels Durchflusszytometrie stellt weiterhin einen vielversprechenden Biomarker f{\"u}r die Sepsis-Fr{\"u}herkennung dar. F{\"u}r weitere Schlussfolgerungen ist jedoch eine gr{\"o}ßere Kohorte erforderlich. In nachfolgenden Untersuchungen sollten zudem mechanistische Ursachen der beschriebenen ph{\"a}notypischen und funktionellen Auff{\"a}lligkeiten von Thrombozyten bei Infektion und Sepsis z.B. mittels Koinkubationsexperimenten untersucht werden.},
  subject      = {Sepsis},
  language  = {de}
}
@phdthesis{Blickle2024,
  author    = {Blickle, Marc Manuel},
  title     = {Das Zusammenspiel von Herz und Gehirn: Interozeptive Genauigkeit, Herzratenvariabilit{\"a}t und funktionelle Konnektivit{\"a}t kortikaler Netzwerke bei depressiven Patientinnen und Patienten},
  doi       = {10.25972/OPUS-31676},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-316762},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Hintergrund: Depressionen z{\"a}hlen zu den h{\"a}ufigsten psychischen Erkrankungen. Depressive Symptome umfassen beeintr{\"a}chtigte kognitive Funktionen, vegetative Beschwerden und ein ver{\"a}ndertes emotionales Erleben. Die defizit{\"a}re Wahrnehmung interner k{\"o}rperlicher Signale wird sowohl mit der Pathogenese der Depression als auch mit Angstst{\"o}rungen in Verbindung gebracht. Interozeptive Genauigkeit (IAc) beschreibt dabei die F{\"a}higkeit, k{\"o}rperliche Empfindungen wie den eigenen Herzschlag akkurat wahrzunehmen und wird mit einer Herzwahrnehmungsaufgabe erfasst. In bildgebenden Verfahren wie der funktionellen Magnetresonanztomografie (fMRT) war eine niedrigere IAc mit einer verringerten Inselaktivit{\"a}t assoziiert. W{\"a}hrend der Ruhezustandsmessung des Gehirns (resting-state fMRT) kann in Abwesenheit einer Aufgabe die intrinsische Aktivit{\"a}t des Gehirns gemessen werden. Dies erm{\"o}glicht die Identifizierung von kortikalen Netzwerken. Depressive Patienten weisen eine ver{\"a}nderte funktionelle Konnektivit{\"a}t innerhalb und zwischen einzelnen Netzwerken wie dem Salience Network (SN), welchem die Insel zugerechnet wird, und dem Default Mode Network (DMN) auf. Bisherige Studien, in denen {\"u}berwiegend j{\"u}ngere depressive Patienten untersucht wurden, kamen jedoch hinsichtlich der IAc und den kortikalen Netzwerken zu inkonsistenten Ergebnissen. Insbesondere ist unklar, inwieweit sich die IAc nach einem Therapieansprechen ver{\"a}ndert, von der Herzratenvariabilit{\"a}t (HRV) moduliert wird und welche Auswirkungen dies auf die funktionelle Konnektivit{\"a}t kortikaler Netzwerke hat. Ziele: Eine ver{\"a}nderte IAc und HRV wie auch funktionelle Konnektivit{\"a}tsunterschiede im DMN und SN k{\"o}nnten Biomarker der Depression darstellen. Im Rahmen einer L{\"a}ngsschnittuntersuchung wurde getestet, ob {\"a}ltere depressive Patienten {\"u}ber eine verringerte IAc, eine geringere HRV und {\"u}ber eine ver{\"a}nderte funktionelle Konnektivit{\"a}t im SN sowie DMN verf{\"u}gen. Dar{\"u}ber hinaus sollte erforscht werden, in welchem Ausmaß sich Patienten, die auf die Behandlung ansprachen (Responder), von sogenannten Non-Respondern in Bezug auf die IAc, die HRV, das SN und das DMN unterschieden. Methoden: In Studie 1 (Baseline) wurden 30 gr{\"o}ßtenteils medizierte, schwer depressive Patienten (> 50 Jahre) und 30 gesunde Kontrollprobanden untersucht. Die IAc wurde in einer Herzwahrnehmungsaufgabe ermittelt und die HRV bestimmt. Zus{\"a}tzlich wurde eine resting-state fMRT durchgef{\"u}hrt. Eine funktionelle Konnektivit{\"a}tsanalyse f{\"u}r Saatregionen im SN und DMN wurde mit einem saatbasierten Ansatz (seed-to-voxel) durchgef{\"u}hrt. F{\"u}r eine Subgruppenanalyse wurde die Patientengruppe in {\"a}ngstlich-depressive und nicht-{\"a}ngstlich depressive Patienten unterteilt. In Studie 2 (sechs Monate Follow-up) wurde die Studienkohorte nochmals untersucht. Es nahmen 21 Personen der Patientengruppe und 28 Probanden der Kontrollgruppe teil. Wiederum wurden die IAc und die HRV bestimmt. Außerdem fand eine resting-state fMRT-Messung statt. Die Patientengruppe wurde unterteilt in depressive Responder und Non-Responder. Ergebnisse: In Studie 1 zeigten depressive Patienten eine funktionelle Hypokonnektivit{\"a}t zwischen einzelnen Saatregionen der Insel (SN) und Teilen des superioren frontalen Gyrus, des supplement{\"a}rmotorischen Cortex, des lateralen okzipitalen Cortex sowie des Okzipitalpols. Zudem wiesen depressive Patienten zwischen der Saatregion im anterioren Teil des DMN und der Insel sowie dem Operculum eine erh{\"o}hte funktionelle Konnektivit{\"a}t auf. Die Gruppen unterschieden sich nicht in der IAc und der HRV. {\"A}ngstlich-depressive Patienten zeigten eine h{\"o}here funktionelle Konnektivit{\"a}t innerhalb der Insel als nicht-{\"a}ngstlich depressive Patienten, jedoch zeigten sich keine Unterschiede in der IAc und der HRV. In Studie 2 wiesen depressive Non-Responder im Vergleich zu Respondern eine Hyperkonnektivit{\"a}t zwischen dem posterioren DMN und dem Frontalpol sowie zwischen dem posterioren DMN und temporalen Arealen im SN auf. Keine funktionellen Konnektivit{\"a}tsunterschiede zeigten sich f{\"u}r die Saatregionen im SN. Depressive Responder, Non-Responder und die Kontrollprobanden unterschieden sich in ihrer IAc und HRV nicht. Schlussfolgerungen: Die Ergebnisse der Studien unterstreichen, dass bei depressiven Patienten, Respondern und Non-Respondern Unterschiede in der intrinsischen Gehirnaktivit{\"a}t funktioneller Netzwerke bestehen, jedoch nicht in der akkuraten Wahrnehmung des eigenen Herzschlages und der HRV. Therapeutische Interventionen, die auf eine Verbesserung der IAc abzielen, k{\"o}nnten insbesondere f{\"u}r Non-Responder dennoch eine zus{\"a}tzliche Behandlungsm{\"o}glichkeit darstellen. F{\"u}r eine personalisierte Medizin k{\"o}nnte die weitere Erforschung von kortikalen Netzwerken einen wesentlichen Beitrag leisten, um ein individuelles Therapieansprechen zu pr{\"a}dizieren.},
  subject      = {Depression},
  language  = {de}
}
@phdthesis{Dekant2024,
  author    = {Dekant, Raphael H.},
  title     = {Species-differences in the \(in\) \(vitro\) biotransformation of trifluoroethene (HFO-1123)},
  doi       = {10.25972/OPUS-31403},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-314035},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {1,1,2-trifluoroethene (HFO-1123) is intended for use as a refrigerant. Inhalation studies on HFO-1123 in rats suggested a low potential for toxicity, with no-observed-adverse-effect levels greater then 20,000 ppm. However, single inhalation exposure of Goettingen Minipigs and New Zealand White Rabbits resulted in mortality. It was assumed that conjugation of HFO-1123 with glutathione, via glutathione S-transferase, gives rise to S-(1,1,2-trifluoroethyl)-L-glutathione (1123-GSH), which is then transformed to the corresponding cysteine S-conjugate (S-(1,1,2-trifluoroethyl)-L-cysteine, 1123-CYS). Subsequent beta-lyase mediated cleavage of 1123-CYS may result in monofluoroacetic acid, a potent inhibitor of aconitase. Species-differences in 1123-GSH formation and 1123-CYS cleavage to MFA may explain species-differences in HFO-1123 toxicity. This study was designed to test the hypothesis, that GSH-dependent biotransformation and subsequent beta-lyase mediated formation of monofluoroacetic acid, a potent inhibitor of aconitase in the citric acid cycle, may play a key role in HFO-1123 toxicity and to evaluate if species-differences in the extent of MFA formation may account for the species-differences in HFO-1123 toxicity. The overall objective was to determine species-differences in HFO-1123 biotransformation in susceptible vs. less susceptible species and humans as a basis for human risk assessment. To this end, in vitro biotransformation of HFO-1123 and 1123-CYS was investigated in renal and hepatic subcellular fractions of mice, rats, humans, Goettingen Minipigs and NZW Rabbits. Furthermore, cytotoxicity and metabolism of 1123-CYS was assessed in cultured renal epithelial cells. Enzyme kinetic parameters for beta-lyase mediated cleavage of 1123-CYS in renal and hepatic cytosolic fractions were determined, and 19F-NMR was used to identify fluorine containing metabolites arising from 1123-CYS cleavage. Quantification of 1123-GSH formation in hepatic S9 fractions after incubation with HFO-1123 was performed by LC-MS/MS and hepatic metabolism of HFO-1123 was monitored by 19F-NMR. Rates of 1123-GSH formation were increased in rat, mouse and NZW Rabbit compared to human and Goettingen hepatic S9, indicating increased GSH dependent biotransformation in rats, mouse and NZW Rabbits. NZW Rabbit hepatic S9 exhibited increased 1123-GSH formation in the presence compared to the absence of acivicin, a specific gamma-GT inhibitor. This indicates increased gamma-GT mediated cleavage of 1123-GSH in NZW Rabbit hepatic S9 compared to the other species. 19F-NMR confirmed formation of 1123-GSH as the main metabolite of GSH mediated biotransformation of HFO-1123 in hepatic S9 fractions next to F-. Increased F- formation was detected in NZW Rabbit and Goettingen Minipig hepatic S9 in the presence of an NADPH regenerating system, indicating a higher rate of CYP-450 mediated metabolism in these species. Based on these findings, it is possible that CYP-450 mediated metabolism may contribute to HFO-1123 toxicity. In contrast to the increased formation of 1123-GSH in rat, mouse and NZW Rabbit hepatic S9 (compared to human and Goettingen Minipig), enzyme kinetic studies revealed a significantly higher beta-lyase activity towards 1123-CYS in renal cytosol of Goettingen Minipigs compared to cytosol from rats, mice, humans and NZW Rabbits. However, beta-lyase cleavage in renal NZW Rabbit cytosol was slightly increased compared to rat, mouse and human renal cytosols. 19F-NMR analysis confirmed increased time-dependent formation of MFA in renal Goettingen Minipig cytosol and NZW Rabbit (compared to human and rat cytosolic fractions). Three structurally not defined MFA-derivatives were detected exclusively in NZW Rabbit and Goettingen Minipig cytosols. Also, porcine kidney cells were more sensitive to cytotoxicity of 1123-CYS compared to rat and human kidney cells. Overall, increased beta-lyase mediate cleavage of 1123-CYS to MFA in Goettingen Minipig and NZW Rabbit kidney (compared to human and rat) may support the hypothesis that enzymatic cleavage by beta-lyases may account for the species-differences in HFO-1123 toxicity. However, the extent of GST mediated biotransformation in the liver as the initial step in HFO-1123 metabolism does not fully agree with this hypothesis, since 1123-GSH formation occurs at higher rates in rat, mouse and NZW Rabbit S9 as compared to the Goettingen Minipig. Based on the inconsistencies between the extent of GST and beta-lyase mediated biotransformation of HFO-1123 obtained by this study, a decisive statement about an increased biotransformation of HFO-1123 in susceptible species with a direct linkage to the species-specific toxicity cannot be drawn. Resulting from this, a clear and reliable conclusion regarding the risk for human health originating from HFO-1123 cannot be made. However, considering the death of Goettingen Minipigs and NZW Rabbits after inhalation exposure of HFO-1123 at concentrations great than 500 ppm and greater than 1250 ppm, respectively, this indicates a health concern for humans under peak exposure conditions. For a successful registration of HFO-1123 and its use as a refrigerant, further in vitro and in vivo investigations addressing uncertainties in the species-specific toxicity of HFO-1123 are urgently needed.},
  subject      = {Biotransformation},
  language  = {en}
}
@phdthesis{Bakirci2024,
  author    = {Bakirci, Ezgi},
  title     = {Development of \(In\) \(vitro\) Models for Tissue Engineering Applications Using a High-Resolution 3D Printing Technology},
  doi       = {10.25972/OPUS-25164},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251645},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {In vitro models mimic the tissue-specific anatomy and play essential roles in personalized medicine and disease treatments. As a sophisticated manufacturing technology, 3D printing overcomes the limitations of traditional technologies and provides an excellent potential for developing in vitro models to mimic native tissue. This thesis aims to investigate the potential of a high-resolution 3D printing technology, melt electrowriting (MEW), for fabricating in vitro models. MEW has a distinct capacity for depositing micron size fibers with a defined design. In this thesis, three approaches were used, including 1) extending the MEW polymer library for different biomedical applications, 2) developing in vitro models for evaluation of cell growth and migration toward the different matrices, and 3) studying the effect of scaffold designs and biochemical cues of microenvironments on cells. First, we introduce the MEW processability of (AB)n and (ABAC)n segmented copolymers, which have thermally reversible network formulation based on physical crosslinks. Bisurea segments are combined with hydrophobic poly(dimethylsiloxane) (PDMS) or hydrophilic poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide) (PPO-PEG-PPO) segments to form the (AB)n segmented copolymers. (ABAC)n segmented copolymers contain all three segments: in addition to bisurea, both hydrophobic and hydrophilic segments are available in the same polymer chain, resulting in tunable mechanical and biological behaviors. MEW copolymers either support cells attachment or dissolve without cytotoxic side effects when in contact with the polymers at lower concentrations, indicating that this copolymer class has potential in biological applications. The unique biological and surface properties, transparency, adjustable hydrophilicity of these copolymers could be beneficial in several in vitro models. The second manuscript addresses the design and development of a melt electrowritten competitive 3D radial migration device. The approach differs from most of the previous literature, as MEW is not used here to produce cell invasive scaffolds but to fabricate an in vitro device. The device is utilized to systematically determine the matrix which promotes cell migration and growth of glioblastoma cells. The glioblastoma cell migration is tested on four different Matrigel concentrations using a melt electrowritten radial device. The glioblastoma U87 cell growth and migration increase at Matrigel concentrations 6 and 8 mg mL-1 In the development of this radial device, the accuracy, and precision of melt electrowritten circular shapes were investigated. The results show that the printing speed and design diameter are essential parameters for the accuracy of printed constructs. It is the first instance where MEW is used for the production of in vitro devices. The influence of biochemical cues and scaffold designs on astrocytes and glioblastoma is investigated in the last manuscript. A fiber comprising the box and triangle-shaped pores within MEW scaffolds are modified with biochemical cues, including RGD and IKVAV peptides using a reactive NCO-sP(EO-stat-PO) macromer. The results show that astrocytes and glioblastoma cells exhibit different phenotypes on scaffold designs and peptide-coated scaffolds.},
  subject      = {3D-Druck},
  language  = {en}
}
@phdthesis{Blahetek2024,
  author    = {Blahetek, Gina},
  title     = {The role of alternative intronic polyadenylation on microRNA biogenesis in melanoma},
  doi       = {10.25972/OPUS-25474},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254743},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {mRNA is co- or post-transcriptionally processed from a precursor mRNA to a mature mRNA. In addition to 5'capping and splicing, these modifications also include polyadenylation, the addition of a polyA tail to the 3'end of the mRNA. In recent years, alternative polyadenylation in particular has increasingly been taken into account as a mechanism for regulating gene expression. It is assumed that approximately 70-75 \% of human protein coding genes contain alternative polyadenylation signals, which are often located within intronic sequences of protein-coding genes. The use of such polyadenylation signals leads to shortened mRNA transcripts and thus to the generation of C-terminal shortened protein isoforms. Interestingly, the majority of microRNAs, small non-coding RNAs that play an essential role in post-transcriptional gene regulation, are also encoded in intronic sequences of protein-coding genes and are co-transcriptionally expressed with their host genes. The biogenesis of microRNA has been well studied and is well known, but mechanisms that may influence the expression regulation of mature microRNAs are just poorly understood. In the presented work, I aimed to investigate the influence of alternative intronic polyadenylation on the biogenesis of microRNAs. The human ion channel TRPM1 could already be associated with melanoma pathogenesis and truncated isoforms of this protein have already been described in literature. In addition, TRPM1 harbors a microRNA, miR211, in its sixth intron, which is assumed to act as a tumor suppressor. Since both, TRPM1 and miR211 have already been associated with melanoma pathogenesis, the shift towards truncated transcripts during the development of various cancers is already known and it has been shown that certain microRNAs play a crucial role in the development and progression of melanoma, melanoma cell lines were used as an in vitro model for these investigations.},
  subject      = {Polyadenylierung},
  language  = {en}
}
@phdthesis{Behne2024,
  author    = {Behne, Robert Stefan Friedrich},
  title     = {Development Of A Human iPSC-Derived Cortical Neuron Model Of Adaptor- Protein-Complex-4-Deficiency},
  doi       = {10.25972/OPUS-35139},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351390},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Adaptor-protein-4-deficiency (AP-4-deficiency) is an autosomal-recessive childhood- onset form of complicated hereditary spastic paraplegia (HSP) caused by bi-allelic loss- of-function mutations in one of the four subunits of the AP-4-complex. These four conditions are named SPG47 (AP4B1, OMIM \#614066), SPG50 (AP4M1, OMIM \#612936), SPG51 (AP4E1, OMIM \#613744) and SPG52 (AP4S1, OMIM \#614067), respectively and all present with global developmental delay, progressive spasticity and seizures. Imaging features include a thinning of the corpus callosum, ventriculomegaly and white matter changes. AP-4 is a highly conserved heterotetrameric complex, which is responsible for polarized sorting of transmembrane cargo including the autophagy- related protein 9 A (ATG9A). Loss of any of the four subunits leads to an instable complex and defective sorting of AP-4-cargo. ATG9A is implicated in autophagosome formation and neurite outgrowth. It is missorted in AP-4-deficient cells and CNS-specific knockout of Atg9a in mice results in a phenotype reminiscent of AP-4-deficiency. However, the AP-4-related cellular phenotypes including ATG9A missorting have not been investigated in human neurons. Thus, the aim of this study is to provide the first human induced pluripotent stem cell- derived (iPSC) cortical neuron model of AP-4-deficiency to explore AP-4-related phenotypes in preparation for a high-content screening. Under the hypothesis that AP-4- deficiency leads to ATG9A missorting, elevated ATG9A levels, impaired autophagy and neurite outgrowth in human iPSC-derived cortical neurons, in vitro biochemical and imaging assays including automated high-content imaging and analysis were applied. First, these phenotypes were investigated in fibroblasts from three patients with compound heterozygous mutations in the AP4B1 gene and their sex-matched parental controls. The same cell lines were used to generate iPSCs and differentiate them into human excitatory cortical neurons. This work shows that ATG9A is accumulating in the trans-Golgi-network in AP-4- deficient human fibroblasts and that ATG9A levels are increased compared to parental controls and wild type cells suggesting a compensatory mechanism. Protein levels of the AP4E1-subunit were used as a surrogate marker for the AP-4-complex and were decreased in AP-4-deficient fibroblasts with co-immunoprecipitation confirming the instability of the complex. Lentiviral re-expression of the AP4B1-subunit rescues this corroborating the fact that a stable AP-4-complex is needed for ATG9A trafficking. Surprisingly, autophagic flux was present in AP-4-deficient fibroblasts under nutrient- rich and starvation conditions. These phenotypic markers were evaluated in iPSC-derived cortical neurons and here, a robust accumulation of ATG9A in the juxtanuclear area was seen together with elevated ATG9A protein levels. Strikingly, assessment of autophagy markers under nutrient-rich conditions showed alterations in AP-4-deficient iPSC- derived cortical neurons indicating dysfunctional autophagosome formation. These findings point towards a neuron-specific impairment of autophagy and need further investigation. Adding to the range of AP-4-related phenotypes, neurite outgrowth and branching are impaired in AP-4-deficient iPSC-derived cortical neurons as early as 24h after plating and together with recent studies point towards a distinct role of ATG9A in neurodevelopment independent of autophagy. Together, this work provides the first patient-derived neuron model of AP-4-deficiency and shows that ATG9A is sorted in an AP-4-dependent manner. It establishes ATG9A- related phenotypes and impaired neurite outgrowth as robust markers for a high-content screening. This disease model holds the promise of providing a platform to further study AP-4-deficiency and to search for novel therapeutic targets.},
  subject      = {Adaptorproteine},
  language  = {en}
}
@phdthesis{Stark2024,
  author    = {Stark, Irmgard Katharina},
  title     = {Einfluss von Interferon auf das Infektionsverhalten von Herpes simplex Virus 1 und seiner DUB - Mutante C65A in der Zellkultur},
  doi       = {10.25972/OPUS-35195},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351950},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Die Erforschung viraler Proteine ist wichtig, um virale Infektionen besser verstehen und damit therapieren zu k{\"o}nnen. Die Aufkl{\"a}rung der DUB-Funktion auf dem viralen Herpesprotein pUL36 erm{\"o}glicht ein besseres Verst{\"a}ndnis des Infektionshergangs und k{\"o}nnte zur Entwicklung eines Enzyminhibitors f{\"u}hren, der nur an diesem Enzym ansetzt, nachdem es sich von den zellul{\"a}ren DUBs unterscheidet (Kattenhorn et al., 2005). In dieser Arbeit konnten die vorherigen Daten, die eine st{\"a}rkere Hemmung der DUB- Mutante unter Interferoneinfluss zeigten, in unterschiedlichen Assay-Designs best{\"a}tigt werden. Auch Versuche mit einem anderen Herpes simplex Virus Strang, best{\"a}tigten die vorherigen Daten. Die Ergebnisse zeigen, dass die DUB-Funktion f{\"u}r HSV-1 wichtig ist f{\"u}r die virale Evasion der zellul{\"a}ren Immunantwort. Die genaue Funktion der DUB in der Infektion ist jedoch unklar. Aufgrund der vorbestehenden Datenlage erschien am wahrscheinlichsten, dass die DUB-Funktion vor Eindringen des Herpes Simplex Virus in den Zellkern zum Tragen kommt, womit es nach Abnahme des Interferons nicht zu einer viralen Reaktivierung k{\"a}me. Deshalb wurden Untersuchungen unternommen, um eine m{\"o}gliche Reaktivierung nach Abnahme des Interferons n{\"a}her zu untersuchen. Hierf{\"u}r wurden zwei verschiedene Experimente entwickelt. Einmal wurde das Interferon direkt nach Infektion und einmal 3 Tage nach Infektion (3dpi) abgenommen. Die Ergebnisse zeigten beide eine st{\"a}rkere Hemmung der DUB-HSV-1-Mutante unter Interferoneinfluss. Bei Abnahme des Interferons direkt nach Infektion lag bei Wildtyp und Mutante ein leichter Anstieg der Plaquezahlen vor, wobei dieser Effekt von der Dosis des Interferons abh{\"a}ngig war. Eine hohe Interferondosis beg{\"u}nstigte bei beiden eine st{\"a}rkere Hemmung, allerdings bei beiden auch eine leichte Erh{\"o}hung der Plaquezahl nach Abnahme. Bei einer niedrigen Dosis konnte nur eine st{\"a}rkere Hemmung der DUB-Mutante, jedoch keine Reaktivierung bei Wildtyp und Mutante nach Abnahme des Interferons gezeigt werden. Bei Abnahme drei Tage nach Infektion zeigte sich sowohl bei dem Wildtyp-Virus als auch der DUB- Mutante kein Anstieg in den Plaquezahlen. Es sind, nachdem Deubiquitinierung nicht nur eine Rolle in der Verhinderung des proteosomalen Abbaus von in die Zelle eingedrungenem Virus spielt, sondern auch der Zellregulation, mehrere Szenarien denkbar, die diesen Ph{\"a}notyp erkl{\"a}ren k{\"o}nnten. Die DUB-Funktion k{\"o}nnte zwar den proteosomalen Abbau durch Deubiqutinierung und damit Verhinderung der Markierung des Virus zum zellul{\"a}ren Abbau verhindern. Allerdings k{\"o}nnten sich durch einen langsameren Transport aus der Zelle oder in den Nucleus auch weniger Plaques bei der Mutante als wie beim Wildtyp unter Interferoneinfluss bilden, nachdem das Virus dann leichter Ziel antiviraler Proteine werden k{\"o}nnte. Oder die DUB-Funktion spielt eine Rolle beim Eintritt in den Kern durch Modifikationen anderer Proteine. Virengenome k{\"o}nnten auch durch eine fehlende DUB-Funktion reprimiert werden oder die Zelle durch Apoptose absterben. Interessanterweise konnte keine Hemmung der DUB-Mutante in Interferon behandelten U-2 OS Zellen gezeigt werden, von denen ein Defekt im STING- vermittelten Signalweg bekannt ist. Vielleicht zeigt dies, dass das STING-Protein an dem gezeigten DUB-Ph{\"a}notyp beteiligt ist. Nachgewiesen ist außerdem bereits eine Funktion des Enzyms bei der zweiten Umh{\"u}llung der Kapside bei Pseudorabiesvirus (M{\"o}hl, 2011). Weitere Untersuchungen unter Einsatz bspw. von Immunfluoreszenz, Proteasominhibitoren oder weiteren Zelllinien wie Saos-2, sind n{\"o}tig, um die genaue Funktion zu kl{\"a}ren.},
  subject      = {Interferon},
  language  = {de}
}
@phdthesis{Reissland2024,
  author    = {Reissland, Michaela},
  title     = {USP10 is a \(de\) \(novo\) tumour-specific regulator of β-Catenin and contributes to cancer stem cell maintenance and tumour progression},
  doi       = {10.25972/OPUS-31957},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319579},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Colorectal Cancer (CRC) is the third most common cancer in the US. The majority of CRC cases are due to deregulated WNT-signalling pathway. These alterations are mainly caused by mutations in the tumour suppressor gene APC or in CTNNB1, encoding the key effector protein of this pathway, β-Catenin. In canonical WNT-signalling, β-Catenin activates the transcription of several target genes, encoding for proteins involved in proliferation, such as MYC, JUN and NOTCH. Being such a critical regulator of these proto-oncogenes, the stability of β-Catenin is tightly regulated by the Ubiquitin-Proteasome System. Several E3 ligases that ubiquitylate and degrade β-Catenin have been described in the past, but the antagonists, the deubiquitylases, are still unknown. By performing an unbiased siRNA screen, the deubiquitylase USP10 was identified as a de novo positive regulator of β-Catenin stability in CRC derived cells. USP10 has previously been shown in the literature to regulate both mutant and wild type TP53 stability, to deubiquitylate NOTCH1 in endothelial cells and to be involved in the regulation of AMPKα signalling. Overall, however, its role in colorectal tumorigenesis remains controversial. By analysing publicly available protein and gene expression data from colorectal cancer patients, we have shown that USP10 is strongly upregulated or amplified upon transformation and that its expression correlates positively with CTNNB1 expression. In contrast, basal USP10 levels were found in non-transformed tissues, but surprisingly USP10 is upregulated in intestinal stem cells. Endogenous interaction studies in CRC-derived cell lines, with different extend of APCtruncation, revealed an APC-dependent mode of action for both proteins. Furthermore, by utilising CRISPR/Cas9, shRNA-mediated knock-down and overexpression of USP10, we could demonstrate a regulation of β-Catenin stability by USP10 in CRC cell lines. It is widely excepted that 2D cell culture systems do not reflect complexity, architecture and heterogeneity and are therefore not suitable to answer complex biological questions. To overcome this, we established the isolation, cultivation and genetically modification of murine intestinal organoids and utilised this system to study Usp10s role ex vivo. By performing RNA sequencing, dependent on different Usp10 levels, we were able to recapitulate the previous findings and demonstrated Usp10 as important regulator of β-dependent regulation of stem cell homeostasis. Since genetic depletion of USP10 resulted in down-regulation of β-Catenin-dependent transcription, therapeutic intervention of USP10 in colorectal cancer was also investigated. Commercial and newly developed inhibitors were tested for their efficacy against USP10, but failed to significantly inhibit USP10 activity in colorectal cancer cells. To validate the findings from this work also in vivo, development of a novel mouse model for colorectal cancer has begun. By combining CRISPR/Cas9 and classical genetic engineering with viral injection strategies, WT and genetically modified mice could be transformed and, at least in some animals, intestinal lesions were detectable at the microscopic level. The inhibition of USP10, which we could describe as a de novo tumour-specific regulator of β-Catenin, could become a new therapeutic strategy for colorectal cancer patients.},
  subject      = {Biomedizin},
  language  = {en}
}
@phdthesis{Gaballa2024,
  author    = {Gaballa, Abdallah Hatem Hassan Hosny Ahmed},
  title     = {PAF1c drives MYC-mediated immune evasion in pancreatic ductal adenocarcinoma},
  doi       = {10.25972/OPUS-36045},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-360459},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The expression of the MYC proto-oncogene is elevated in a large proportion of patients with pancreatic ductal adenocarcinoma (PDAC). Previous findings in PDAC have shown that this increased MYC expression mediates immune evasion and promotes S-phase progression. How these functions are mediated and whether a downstream factor of MYC mediates these functions has remained elusive. Recent studies identifying the MYC interactome revealed a complex network of interaction partners, highlighting the need to identify the oncogenic pathway of MYC in an unbiased manner. In this work, we have shown that MYC ensures genomic stability during S-phase and prevents transcription-replication conflicts. Depletion of MYC and inhibition of ATR kinase showed a synergistic effect to induce DNA damage. A targeted siRNA screen targeting downstream factors of MYC revealed that PAF1c is required for DNA repair and S-phase progression. Recruitment of PAF1c to RNAPII was shown to be MYC dependent. PAF1c was shown to be largely dispensable for cell proliferation and regulation of MYC target genes. Depletion of CTR9, a subunit of PAF1c, caused strong tumor regression in a pancreatic ductal adenocarcinoma model, with long-term survival in a subset of mice. This effect was not due to induction of DNA damage, but to restoration of tumor immune surveillance. Depletion of PAF1c resulted in the release of RNAPII with transcription elongation factors, including SPT6, from the bodies of long genes, promoting full-length transcription of short genes. This resulted in the downregulation of long DNA repair genes and the concomitant upregulation of short genes, including MHC class I genes. These data demonstrate that a balance between long and short gene transcription is essential for tumor progression and that interference with PAF1c levels shifts this balance toward a tumor-suppressive transcriptional program. It also directly links MYC-mediated S-phase progression to immune evasion. Unlike MYC, PAF1c has a stable, known folded structure; therefore, the development of a small molecule targeting PAF1c may disrupt the immune evasive function of MYC while sparing its physiological functions in cellular growth.},
  subject      = {Myc},
  language  = {en}
}
@phdthesis{CruzdeCasas2024,
  author    = {Cruz de Casas, Paulina},
  title     = {Sphingolipids as modulators of T cell function},
  doi       = {10.25972/OPUS-35969},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-359698},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The immune system is responsible for the preservation of homeostasis whenever a given organism is exposed to distinct kinds of perturbations. Given the complexity of certain organisms like mammals, and the diverse types of challenges that they encounter (e.g. infection or disease), the immune system evolved to harbor a great variety of distinct immune cell populations with specialized functions. For instance, the family of T cells is sub-divided into conventional (Tconv) and unconventional T cells (UTCs). Tconv form part of the adaptive arm of the immune system and are comprised of αβ CD4+ or CD8+ cells that differentiate from na{\"i}ve to effector and memory populations upon activation and are essential during infection and cancer. Furthermore, UTCs, which include γδ T cells, NKT and MAIT, are involved in innate and adaptive immune responses, due to their dual mode of activation, through cytokines (innate-like) or TCR (adaptive), and function. Despite our understanding of the basic functions of T cells in several contexts, a great number of open questions related to their basic biology remain. For instance, the mechanism behind the differentiation of na{\"i}ve CD4+ and CD8+ T cells into effector and memory populations is not fully understood. Moreover, the exact function and relevance of distinct UTC subpopulations in a physiological context have not been fully clarified. Here, we investigated the factors mediating na{\"i}ve CD8+ T cell differentiation into effector and memory cells. By using flow cytometry, mass spectrometry, enzymatic assays, and transgenic mouse models, we found that the membrane bound enzyme sphingomyelin-phosphodiesterase acid-like 3b (Smpdl3b) is crucial for the maintenance of memory CD8+ T cells. Our data show that the absence of Smpdl3b leads to diminished CD8+ T cell memory, and a loss of stem-like memory populations due to an aggravated contraction. Our scRNA-seq data suggest that Smpdl3b could be involved in clathrinmediated endocytosis through modulation of Huntingtin interacting protein 1 (Hip1) levels, likely regulating TCR-independent signaling events. Furthermore, in this study we explored the role of UTCs in lymph node-specific immune responses. By using transgenic mouse models for photolabeling, lymph node transplantation models, infection models and flow cytometry, we demonstrate that S1P regulates the migration of tissue-derived UTC from tissues to draining lymph nodes, resulting in heterogeneous immune responses mounted by lymph nodes draining different tissues. Moreover, our unbiased scRNAseq and single lineage-deficient mouse models analysis revealed that all UTC lineages (γδ T cells, NKT and MAIT) are organized in functional units, based on transcriptional homogeneity, shared microanatomical location and migratory behavior, and numerical and functional redundancy. Taken together, our studies describe additional cell intrinsic (Smpdl3b) and extrinsic (S1Pmediated migration) functions of sphingolipid metabolism modulating T cell biology. We propose the S1P/S1PR1/5 signaling axis as the potential survival pathway for Smpdl3b+ memory CD8+ T cells and UTCs, mainly in lymph nodes. Possibly, Smpdl3b regulates S1P/S1PR signaling by balancing ligandreceptor endocytosis, while UTCs migrate to lymph nodes during homeostasis to be exposed to specific levels of S1P that assure their maintenance. Our results are clinically relevant, since several drugs modulating the S1P/S1PR signaling axis or the levels of Smpdl3b are currently used to treat human diseases, such as multiple sclerosis and B cell-mediated diseases. We hope that our discoveries will inspire future studies focusing on sphingolipid metabolism in immune cell biology.},
  subject      = {T-Lymphozyt},
  language  = {en}
}
@phdthesis{Amini2024,
  author    = {Amini, Emad},
  title     = {How central and peripheral clocks and the neuroendocrine system interact to time eclosion behavior in \(Drosophila\) \(melanogaster\)},
  doi       = {10.25972/OPUS-36130},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-361309},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {To grow larger, insects must shed their old rigid exoskeleton and replace it with a new one. This process is called molting and the motor behavior that sheds the old cuticle is called ecdysis. Holometabolic insects have pupal stages in between their larval and adult forms, during which they perform metamorphosis. The pupal stage ends with eclosion, i.e., the emergence of the adult from the pupal shell. Insects typically eclose at a specific time during the day, likely when abiotic conditions are at their optimum. A newly eclosed insect is fragile and needs time to harden its exoskeleton. Hence, eclosion is regulated by sophisticated developmental and circadian timing mechanisms. In Drosophila melanogaster, eclosion is limited to a daily time window in the morning, regarded as the "eclosion gate". In a population of laboratory flies entrained by light/dark cycles, most of the flies eclose around lights on. This rhythmic eclosion pattern is controlled by the circadian clock and persists even under constant conditions. Developmental timing is under the control of complex hormonal signaling, including the steroid ecdysone, insulin-like peptides, and prothoracicotropic hormone (PTTH). The interactions of the central circadian clock in the brain and a peripheral clock in the prothoracic gland (PG) that produces ecdysone are important for the circadian timing of eclosion. These two clocks are connected by a bilateral pair of peptidergic PTTH neurons (PTTHn) that project to the PG. Before each molt, the ecdysone level rises and then falls shortly before ecdysis. The falling ecdysone level must fall below a certain threshold value for the eclosion gate to open. The activity of PTTHn is inhibited by short neuropeptide F (sNPF) from the small ventrolateral neurons (sLNvs) and inhibition is thought to lead to a decrease in ecdysone production. The general aim of this thesis is to further the understanding of how the circadian clock and neuroendocrinal pathways are coordinated to drive eclosion rhythmicity and to identify when these endocrinal signaling pathways are active. In Chapter I, a series of conditional PTTHn silencing-based behavioral assays, combined with neuronal activity imaging techniques such as non-invasive ARG-Luc show that PTTH signaling is active and required shortly before eclosion and may serve to phase-adjust the activity of the PG at the end of pupal development. Trans-synaptic anatomical stainings identified the sLNvs, dorsal neurons 1 (DN1), dorsal neurons 2 (DN2), and lateral posterior neurons (LPNs) clock neurons as directly upstream of the PTTHn. Eclosion motor behavior is initiated by Ecdysis triggering hormone (ETH) which activates a pair of ventromedial (Vm) neurons to release eclosion hormone (EH) which positively feeds back to the source of ETH, the endocrine Inka cells. In Chapter II trans-synaptic tracing showed that most clock neurons provide input to the Vm and non-canonical EH neurons. Hence, clock can potentially influence the ETH/EH feedback loop. The activity profile of the Inka cells and Vm neurons before eclosion is described. Vm and Inka cells are active around seven hours before eclosion. Interestingly, all EH neurons appear to be exclusively peptidergic. In Chapter III, using chemoconnectomics, PTTHns were found to express receptors for sNPF, allatostatin A (AstA), allatostatin C (AstC), and myosuppressin (Ms), while EH neurons expressed only Ms and AstA receptors. Eclosion assays of flies with impaired AstA, AstC, or Ms signaling do not show arrhythmicity under constant conditions. However, optogenetic activation of the AstA neurons strongly suppresses eclosion. Chapter IV focuses on peripheral ventral' Tracheal dendrite (v'Td) and class IV dendritic arborization (C4da) neurons. The C4da neurons mediate larval light avoidance through endocrine PTTH signaling. The v'Td neurons mainly receive O2/CO2 input from the trachea and are upstream of Vm neurons but are not required for eclosion rhythmicity. Conditional ablation of the C4da neurons or torso (receptor of PTTH) knock-out in the C4da neurons impaired eclosion rhythmicity. Six to seven hours before eclosion, PTTHn, C4da, and Vm neurons are active based on ARG-Luc imaging. Thus, C4da neurons may indirectly connect the PTTHn to the Vm neurons. In summary, this thesis advances our knowledge of the temporal activity and role of PTTH signaling during pupal development and rhythmic eclosion. It further provides a comprehensive characterization of the synaptic and peptidergic inputs from clock neurons to PTTHn and EH neurons. AstA, AstC, and Ms are identified as potential modulators of eclosion circuits and suggest an indirect effect of PTTH signaling on EH signaling via the peripheral sensory C4da neurons.},
  subject      = {Neuroendokrines System},
  language  = {en}
}
@phdthesis{Glueck2024,
  author    = {Gl{\"u}ck, Valentina},
  title     = {Habitual avoidance in trait anxiety and anxiety disorders},
  doi       = {10.25972/OPUS-36022},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-360227},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Maladaptive avoidance behaviors can contribute to the maintenance of fear, anxiety, and anxiety disorders. It has been proposed that, throughout anxiety disorder progression, extensively repeated avoidance may become a habit (i.e., habitual avoidance) instead of being controlled by internal threat-related goals (i.e., goal-directed avoidance). However, the process of the acquisition of habitual avoidance in anxiety disorders is not yet well understood. Accordingly, the current thesis aimed to investigate experimentally whether trait anxiety and anxiety disorders are associated with an increased shift from goal-directed to habitual avoidance. The aim of Study 1 was to develop an experimental operationalization of maladaptive habitual avoidance. To this end, we adapted a commonly used action control task, the outcome devaluation paradigm. In this task, habitual avoidance was operationalized as persistent responses after extensive training to avoid an unpleasant stimulus when the aversive outcome was devalued, i.e., when individuals knew the aversive outcome could not occur anymore. We included indicators for costly and low-cost habitual avoidance, whereby habitual avoidance was associated with a monetary cost, while low-cost habitual avoidance was not associated with monetary costs. In Experiment 1 of Study 1, a pronounced costly and non-costly outcome devaluation effect was observed. However, this result may have partly resulted from trial-and-error learning or a better-safe-than-sorry strategy since not instructions about the stimulus-response-outcome contingencies after the outcome devaluation procedure had been provided to the participants. In Experiment 2 of Study 1, instructions on these stimulus-response-outcome contingencies were included to prevent the potential confounders. As a result, we observed no indicators for costly habitual avoidance, but evidence for low-cost habitual avoidance, potentially because competing goal-directed responses could easily be implemented and inhibited costly habitual avoidance tendencies. In Study 2, the strength of habitual avoidance acquisition was compared between participants with and without anxiety disorders, using the experimental task of Experiment 1 in Study 1. The results indicated that costly and low-cost habitual avoidance was not more pronounced in participants with anxiety disorders than in the healthy control group. However, in an exploratory subgroup comparison, panic disorder predicted more substantial habitual avoidance acquisition than social anxiety disorder. In Study 3, we investigated whether trait anxiety as a risk factor for anxiety disorders is associated with a specific increased shift from goal-directed to habitual avoidance and approach. The task from the Experiment 1 of Study 1 was adapted to include parallel versions for operationalizing habitual avoidance and habitual approach responses. Using a within-subjects design, the individuals - pre-screened for high and low trait anxiety - took part in the approach and the avoidance outcome devaluation task version. The results suggested stronger non-costly habitual responses in more highly trait-anxious individuals independent of the task version, and suggested a tendency towards an impact of trait anxiety on costly habitual approach rather than on costly habitual avoidance. In summary, individuals with high trait anxiety or anxiety disorders did not develop habitual avoidance more readily than individuals with low trait anxiety or without anxiety disorders. Therefore, this thesis does not support the assumption that an increased tendency to acquire habitual avoidance contributes to persistent maladaptive avoidance in anxiety disorders. The thesis also contributes to the discourse on the validity of outcome devaluation studies in general by highlighting the impact of task features, such as the instructions after the outcome devaluation procedure or the task difficulty in the test phase, on the experimental results. Such validity issues may partly explain the heterogeneity of findings in research with the outcome devaluation paradigm. We suggest ways towards more valid operationalizations of habitual avoidance in future studies.},
  subject      = {Gewohnheit},
  language  = {en}
}
@phdthesis{Wussmann2024,
  author    = {Wußmann, Maximiliane},
  title     = {Humane organotypische 3D Modelle des Malignen Melanoms als in vitro Testsystem f{\"u}r die Bewertung der Wirksamkeit von anti-Tumor Therapeutika},
  doi       = {10.25972/OPUS-36100},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-361005},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Das maligne Melanom, eine der seltensten, aber gleichzeitig auch die t{\"o}dlichste dermatologische Malignit{\"a}t, gekennzeichnet durch die Neigung zu einer fr{\"u}hen Metastasierung sowie die rasche Entwicklung von Therapieresistenzen, z{\"a}hlt zu den Tumorentit{\"a}ten mit dem h{\"o}chsten Anstieg der Inzidenz weltweit. Mausmodelle werden h{\"a}ufig verwendet, um die Melanomagenese zu erforschen und neue effektive therapeutische Strategien zu entwickeln, spiegeln die menschliche Physiologie allerdings nur unzureichend wider. In zweidimensionalen (2D) Zellkulturen mangelt es dagegen an wichtigen Komponenten der Mikroumgebung des Tumors und dem dreidimensionalen Gewebekontext. Um dieses Manko zu beheben und die Entwicklung von auf den Menschen {\"u}bertragbaren Tumormodellen in der onkologischen Forschung voranzutreiben, wurde als Alternative zu Zellkulturen und Tierversuchen humane organotypische dreidimensionale (3D) Melanom-Modelle als in vitro Testsystem f{\"u}r die Bewertung der Wirksamkeit von anti-Tumor Therapeutika entwickelt. Im Zuge dieser Arbeit konnte das in vitro Melanom-Modell entscheidend weiterentwickelt werden. So konnten Modelle unterschiedlichster Komplexit{\"a}t etabliert werden, wobei abh{\"a}ngig von der Fragestellung einfachere epidermale bis hin zu unterschiedlich komplexen Vollhautmodellen Anwendung finden. Durch Simulation der Tumor-Mikroumgebung eignen sich diese zur pr{\"a}klinischen Validierung neuer Tumor-Therapeutika, sowie der Erforschung pathologischer Vorg{\"a}nge, von der Tumor-Formierung bis zur Metastasierung. Zudem konnten erfolgreich unterschiedlichste humane Melanomzelllinien ins Modell integriert werden; dadurch, dass sich diese durch ihre Treibermutationen, die zur Krankheitsentstehung beitragen, unterscheiden, stellen sie unterschiedliche Anspr{\"u}che an potentielle therapeutische Angriffspunkte und erm{\"o}glichen das Widerspiegeln vieler Melanom-Subtypen im Modell. Ferner ist es m{\"o}glich, verschiedene Stadien der Tumor-Entwicklung {\"u}ber die Zugabe von Melanomzellen in Einzelsuspension bzw. von Melanom-Sph{\"a}roiden widerzuspiegeln. Es konnte f{\"u}r bestimmte Therapie-Ans{\"a}tze, wie zielgerichtete Therapien, z.B. die Gabe von sich in der Klinik im Einsatz befindlicher BRAF-/MEK-Inhibitoren, gezeigt werden, dass sich die etablierten Modelle hervorragend als pr{\"a}klinische Testsysteme zur Wirksamkeitsbewertung eignen. Zudem bieten sich einzigartige M{\"o}glichkeiten, um die Interaktion humaner Tumorzellen und gesunder Zellen in einem Gewebeverband zu untersuchen. Ferner konnten drei neue technische Analyse-Verfahren zur nicht-invasiven Detektion der Tumor- Pro- und Regression, Beurteilung der Wirksamkeit von potenziellen Anti-Tumor-Therapien sowie der Evaluierung des Tumor-Metabolismusses implementiert werden. Perspektivisch erm{\"o}glichen immun-kompetente Melanom-Modelle die Austestung neuer Immun- und Zelltherapien in einem voll humanen System; gleichzeitig leisten die etablierten Modelle einen signifikanten Beitrag zur Reduktion von Tierexperimenten.},
  subject      = {Melanom},
  language  = {de}
}
@phdthesis{Ramirez2024,
  author    = {Ramirez, Yesid A.},
  title     = {Structural basis of ubiquitin recognition and rational design of novel covalent inhibitors targeting Cdu1 from \(Chlamydia\) \(Trachomatis\)},
  doi       = {10.25972/OPUS-19168},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191683},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The WHO-designated neglected-disease pathogen Chlamydia trachomatis (CT) is a gram-negative bacterium responsible for the most frequently diagnosed sexually transmitted infection worldwide. CT infections can lead to infertility, blindness and reactive arthritis, among others. CT acts as an infectious agent by its ability to evade the immune response of its host, which includes the impairment of the NF-κB mediated inflammatory response and the Mcl1 pro-apoptotic pathway through its deubiquitylating, deneddylating and transacetylating enzyme ChlaDUB1 (Cdu1). Expression of Cdu1 is also connected to host cell Golgi apparatus fragmentation, a key process in CT infections. Cdu1 may this be an attractive drug target for the treatment of CT infections. However, a lead molecule for the development of novel potent inhibitors has been unknown so far. Sequence alignments and phylogenetic searches allocate Cdu1 in the CE clan of cysteine proteases. The adenovirus protease (adenain) also belongs to this clan and shares a high degree of structural similarity with Cdu1. Taking advantage of topological similarities between the active sites of Cdu1 and adenain, a target-hopping approach on a focused set of adenain inhibitors, developed at Novartis, has been pursued. The thereby identified cyano-pyrimidines represent the first active-site directed covalent reversible inhibitors for Cdu1. High-resolution crystal structures of Cdu1 in complex with the covalently bound cyano-pyrimidines as well as with its substrate ubiquitin have been elucidated. The structural data of this thesis, combined with enzymatic assays and covalent docking studies, provide valuable insights into Cdu1s activity, substrate recognition, active site pocket flexibility and potential hotspots for ligand interaction. Structure-informed drug design permitted the optimization of this cyano-pyrimidine based scaffold towards HJR108, the first molecule of its kind specifically designed to disrupt the function of Cdu1. The structures of potentially more potent and selective Cdu1 inhibitors are herein proposed. This thesis provides important insights towards our understanding of the structural basis of ubiquitin recognition by Cdu1, and the basis to design highly specific Cdu1 covalent inhibitors.},
  subject      = {Ubiquitin},
  language  = {en}
}
@phdthesis{Nirchal2024,
  author    = {Nirchal, Naveen Kumar},
  title     = {Mechanistische Regulierung des gastro{\"o}sophagealen {\"U}bergangs und die Rolle der Retins{\"a}ure bei der Entwicklung des Barrett-{\"O}sophagus},
  doi       = {10.25972/OPUS-31155},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311556},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Der gastro{\"o}sophageale {\"U}bergang (GEJ), der die Region abgrenzt, in der der distale {\"O}sophagus auf die proximale Magenregion trifft, ist bekannt f{\"u}r die Entwicklung pathologischer Zust{\"a}nde, wie Metaplasie und Adenokarzinom des {\"O}sophagus (EAC). Es ist wichtig, die Mechanismen der Entwicklungsstadien zu verstehen, die zu EAC f{\"u}hren, da die Inzidenzrate von EAC in den letzten 4 Jahrzehnten um das 7-fache gestiegen ist und die Gesamt{\"u}berlebensrate von 5 Jahren 18,4 \% betr{\"a}gt. In den meisten F{\"a}llenwird die Diagnose im fortgeschrittenen Stadium ohne vorherige Symptome erstellt. Der Hauptvorl{\"a}ufer f{\"u}r die Entwicklung von EAC ist eine pr{\"a}maligne Vorstufe namens Barrett-{\"O}sophagus (BE). BE ist der metaplastische Zustand, bei dem das mehrschichtige Plattenepithel des nativen {\"O}sophagus durch ein spezialisiertes einschichtiges S{\"a}ulenepithel ersetzt wird, das die molekularen Eigenschaften des Magen- sowie des Darmepithels aufweist. Zu den wichtigsten Risikofaktoren f{\"u}r die Entwicklung von BE geh{\"o}ren die chronische gastro{\"o}sophageale Refluxkrankheit (GERD), eine ver{\"a}nderte Mikrobiota und ver{\"a}nderte Retins{\"a}ure-Signalwege (RA). Es ist unklar, welche Zelle der Ursprung f{\"u}r BE ist, da es keine eindeutigen Beweisen f{\"u}r den Prozess der BE-Initiation gibt. In dieser Arbeit habe ich untersucht, wie die GEJ-Hom{\"o}ostase in gesundem Gewebe durch stammzellregulatorische Morphogene aufrechterhalten wird, welche Rolle der Vitamin-A (RA-Signal{\"u}bertragung) spieltund wie ihre Ver{\"a}nderung zur BE-Entwicklung beitr{\"a}gt. Im ersten Teil meiner Dissertation habe ich anhand von Einzelmolek{\"u}l-RNA in situ-Hybridisierung und Immunhistochemie eindeutig das Vorhandensein von zwei Arten von Epithelzellen nachweisen k{\"o}nnen, dem Plattenepithel in der Speiser{\"o}hre und dem S{\"a}ulenepithel imMagenbereich des GEJ. Mittels Abstammungsanalysen im Mausmodell konnte ich zeigen, dass die Epithelzellen des {\"O}sophagus und des Magens von zwei verschiedenen epithelialen Stammzelllinien imGEJ abstammen. Die Grenze zwischen Plattenepithel und S{\"a}ulenepithelzellen im SCJ des GEJ wirddurch gegens{\"a}tzliche Wnt-Mikroumgebungen streng reguliert. Plattenepithelstammzellen des {\"O}sophagus werden durch das Wnt-hemmende Mikroumgebungssignal aufrechterhalten, w{\"a}hrend Magens{\"a}ulenepithelzellen durch das Wnt-aktivierende Signal aus dem Stromakompartiment erhalten werden. Ich habe die in vivo Erhaltung der Epithelstammzellen des GEJ mit Hilfe eines in vitro Epithel-3D-Organoidkulturmodells rekonstruiert. Das Wachstum und die Vermehrung von Magens{\"a}ulenepithel-Organoiden h{\"a}ngen von Wnt-Wachstumsfaktoren ab, w{\"a}hrend das Wachstum von Plattenepithel-Organoiden von Wnt-defizienten Kulturbedingungen abh{\"a}ngt. Dar{\"u}ber hinaus zeigte die Einzelzell-RNA-Sequenzanalyse (scRNA-seq) der aus Organoiden gewonnenenEpithelzellen, dass der nicht-kanonische Wnt/ planar cell polarity (PCP) Signalweg an der Regulierung der Plattenepithelzellen beteiligt ist. Im Gegensatz dazu werden s{\"a}ulenf{\"o}rmige Magenepithelzellen durch den kanonischen Wnt/beta-Catenin- und den nicht-kanonischen Wnt/Ca2+-Weg reguliert. Meine Daten zeigen, dass die SCJ-Epithelzellen, die am GEJ verschmelzen, durch entgegengesetzte stromale Wnt-Faktoren und unterschiedliche Wnt-Weg-Signalee in den Epithelzellen reguliert werden. Im zweiten Teil der Dissertation untersuchte ich die Rolle der bioaktiven Vitamin A Verbindung RA auf {\"O}sophagus- und Magenepithelstammzellen. Die In-vitro-Behandlung von epithelialen Organoiden der Speiser{\"o}hre und des Magens mitRA oder seinem pharmakologischen Inhibitors BMS 493 zeigte, dass jeder Zelltyp unterschiedlich reguliert wurde. Ich beobachtete, dass eine verst{\"a}rkte RA die Differenzierung von Stammzellen und den Verlust der Schichtung f{\"o}rderte, w{\"a}hrend die RA-Hemmung zu einer verst{\"a}rkten Stammzellbildung und Regeneration im mehrschichtigen Epithel der Speiser{\"o}hre f{\"u}hrte. Im Gegensatz zur Speiser{\"o}hre ist der RA-Signalweg in Magen-Organoiden aktiv, und die Hemmung von RA hat ein reduziertes Wachstum von Magen-Organoiden. Globale transkriptomische Daten und scRNA-seq-Daten zeigten, dass derRA-Signalweg einen Ruheph{\"a}notyp in den {\"O}sophaguszellen induziert. Dagegen f{\"u}hrt das Fehlen von RA in Magenepithelzellen zur Expression von Genen, die mit BE assoziiert sind. Daher isteine r{\"a}umlich definierte Regulation der Wnt- und Retins{\"a}ure-Signalgebung amGEJ entscheidend f{\"u}r eine gesunde Hom{\"o}ostase, und ihre St{\"o}rung f{\"u}hrt zur Entwicklung von Krankheiten.},
  subject      = {Retinoes{\"a}ure},
  language  = {en}
}
@phdthesis{Scheiner2024,
  author    = {Scheiner, Christin},
  title     = {Vulnerability in adolescence: prevalence, pandemic impact and prevention},
  doi       = {10.25972/OPUS-35164},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351644},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {This compilation focuses on adolescent mental disorders and their prevention. It comprises three distinct studies, each contributing to a deeper understanding of this critical topic. This work addresses a critical gap in the understanding of, and approach to, adolescent mental health, and as a result reveals a critically important and urgently needed policy implication for action. The thematic structure of these studies begins with an examination of the epidemiology of child and adolescent mental disorders. Baseline data were collected from N = 877 adolescents with a mean age of 12.43 years (SD = 0.65). Mental health problems, such as depressive symptoms, non-suicidal self-injury, suicidal ideation, symptoms of eating disorders, and gender differences, are thoroughly examined. Results revealed a significant portion of our sample displaying mental health problems as early as the 6th and 7th grades, with girls generally being more affected than boys. The findings underscore the importance of early adolescence in the emergence of mental health problems and thereby emphasize the need for preventive measures. Moving beyond prevalence estimates, the compilation delves into the etiology of these disorders, exploring their potential correlation with a COVID-19 infection. Understanding the early signs and risk factors is crucial for timely support. While numerous studies have investigated potential risk and protective factors during the pandemic, our focus shifts to adolescents' coping when an infection with the virus was involved (N = 2,154, M = 12.31, SD = 0.67). We hypothesized that students infected or with close family members infected, would exhibit an increased psychopathology and a decreased functioning of protective factors such as self-efficacy or self-esteem. We found no connection between infection and the mental health status within our sample, but protective factors and mental well-being were positively associated. Thus, universal primary prevention appears to be the preferred approach for promoting mental health. Lastly, the compilation introduces LessStress, a noteworthy contribution to more evidence-based prevention programs. This universal approach is designed to reduce stress in schools, accompanied by a cluster-randomized trial to evaluate its effectiveness (estimated sample size N = 1,894). Existing studies have demonstrated the effectiveness of stress prevention, leading us to introduce a short and easy-to-implement prevention program. There is positive evidence for one-lesson interventions in schools for promoting well-being and health behaviors among adolescents. LessStress is designed based on a life skills approach that not only imparts psychoeducational content but also teaches skills relevant to everyday life and directly applicable. Throughout these studies, a common thread emerges: the pressing need to address mental disorders during childhood and adolescence. These formative years play a pivotal role in the development of mental health problems. These formative years play a crucial role in the development of mental health problems. They highlight the importance of epidemiological data collection and analysis based on the latest models to develop prevention interventions that are not only effective but also reach young people on a global level.},
  subject      = {Jugend},
  language  = {en}
}
@phdthesis{Knorr2024,
  author    = {Knorr, Susanne},
  title     = {Pathophysiology of early-onset isolated dystonia in a DYT-TOR1A rat model with trauma-induced dystonia-like movements},
  doi       = {10.25972/OPUS-20609},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206096},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Early-onset torsion dystonia (DYT-TOR1A, DYT1) is an inherited hyperkinetic movement disorder caused by a mutation of the TOR1A gene encoding the torsinA protein. DYT-TOR1A is characterized as a network disorder of the central nervous system (CNS), including predominantly the cortico-basal ganglia-thalamo-cortical loop resulting in a severe generalized dystonic phenotype. The pathophysiology of DYTTOR1A is not fully understood. Molecular levels up to large-scale network levels of the CNS are suggested to be affected in the pathophysiology of DYT-TOR1A. The reduced penetrance of 30\% - 40\% indicates a gene-environmental interaction, hypothesized as "second hit". The lack of appropriate and phenotypic DYT-TOR1A animal models encouraged us to verify the "second hit" hypothesis through a unilateral peripheral nerve trauma of the sciatic nerve in a transgenic asymptomatic DYT-TOR1A rat model (∆ETorA), overexpressing the human mutated torsinA protein. In a multiscale approach, this animal model was characterized phenotypically and pathophysiologically. Nerve-injured ∆ETorA rats revealed dystonia-like movements (DLM) with a partially generalized phenotype. A physiomarker of human dystonia, describing increased theta oscillation in the globus pallidus internus (GPi), was found in the entopeduncular nucleus (EP), the rodent equivalent to the human GPi, of nerve-injured ∆ETorA rats. Altered oscillation patterns were also observed in the primary motor cortex. Highfrequency stimulation (HFS) of the EP reduced DLM and modulated altered oscillatory activity in the EP and primary motor cortex in nerve-injured ∆ETorA rats. Moreover, the dopaminergic system in ∆ETorA rats demonstrated a significant increased striatal dopamine release and dopamine turnover. Whole transcriptome analysis revealed differentially expressed genes of the circadian clock and the energy metabolism, thereby pointing towards novel, putative pathways in the pathophysiology of DYTTOR1A dystonia. In summary, peripheral nerve trauma can trigger DLM in genetically predisposed asymptomatic ΔETorA rats leading to neurobiological alteration in the central motor network on multiple levels and thereby supporting the "second hit" hypothesis. This novel symptomatic DYT-TOR1A rat model, based on a DYT-TOR1A genetic background, may prove as a valuable chance for DYT-TOR1A dystonia, to further investigate the pathomechanism in more detail and to establish new treatment strategies.},
  subject      = {Dystonie},
  language  = {en}
}
@phdthesis{PenaMosca2024,
  author    = {Pe{\~n}a Mosca, Mar{\´i}a Josefina},
  title     = {Local regulation of T-cell immunity in the intestinal mucosa},
  doi       = {10.25972/OPUS-35266},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352665},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {After priming in Peyer's patches (PPs) and mesenteric lymph nodes (mLN) T- cells infiltrate the intestine through lymphatic draining and homing through the bloodstream. However, we found that in mouse models of acute graft-versus-host disease (GvHD), a subset of alloreactive T-cells directly migrates from PPs to the adjacent intestinal lamina propria (LP), bypassing the normal lymphatic drainage and vascular trafficking routes. Notably, this direct migration occurred in irradiated and unirradiated GvHD models, indicating that irradiation is not a prerequisite for this observed behavior. Next, we established a method termed serial intravascular staining (SIVS) in mouse models to systematically investigate the trafficking and migration of donor T- cells in the early stages of acute GvHD initiation. We found that the direct migration of T-cells from PPs to LP resulted in faster recruitment of cells after allogeneic hematopoietic cell transplantation (allo-HCT). These directly migrating T-cells were found to be in an activated and proliferative state, exhibiting a TH1/TH17-like phenotype and producing cytokines such as IFN-γ and TNF-α. Furthermore, we observed that the directly migrating alloreactive T-cells expressed specific integrins (α4+, αE+) and chemokine receptors (CxCR3+, CCR5+, and CCR9+). Surprisingly, blocking these integrins and chemokine-coupled receptors did not hinder the direct migration of T- cells from PPs to LP, suggesting the involvement of alternative mechanisms. Previous experiments ruled out the involvement of S1PR1 and topographical features of macrophages, leading us to hypothesize that mediators of cytoskeleton reorganization, such as Coro1a, Dock2, or Cdc42, may play a role in this unique migration process. Additionally, we observed that directly migrating T-cells created a local inflammatory microenvironment, which attracts circulating T-cells. Histological analysis confirmed that alloreactive PPs-derived T-cells and bloodborne T-cells colocalized. We employed two experimental approaches, including either photoconversion of T-cells in PPs or direct transfer of activated T-cells into the vasculature, to demonstrate this colocalization. We hypothesize that cytokines released by migrating T-cells, such as IFN-γ and TNF-α, may play a role in recruiting T-cells from the vasculature, as inhibiting chemokine-coupled receptors did not impair recruitment.},
  subject      = {T-Lymphozyt},
  language  = {en}
}
@phdthesis{RombachgebGrosso2024,
  author    = {Rombach [geb. Grosso], Franziska},
  title     = {Der Interaktionsrezeptor des Masernvirus auf h{\"a}matopoetischen Zellen},
  doi       = {10.25972/OPUS-35339},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-353394},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Das Masernvirus (MV) kann in Erkrankten eine schwere, langanhaltende Immunsuppression verursachen, wodurch Infektionen mit opportunistischen Pathogenen beg{\"u}nstigt werden. Diese basiert auf einer Paralyse der h{\"a}matopoetischen Zellen, welche das Virus durch Kontakt eines viralen Glykoproteinkomplexes zu einem unbekannten RezeptorX auf der Zell- Oberfl{\"a}che induzieren kann. Kerncharakterisitika hiervon sind unter anderem die Herabregulation der Akt-Kinase-Phosphorylierung, die Inhibition der zellul{\"a}ren Proliferation und die Aktivierung der neutralen Sphingomyelinase 2 (NSM2). In einem kinetischen Phosphoproteom konnten zwei potentielle Interaktionsrezeptoren des MV identifiziert werden: CD43 und P2X3. Das hochglykosylierte Oberfl{\"a}chenmolek{\"u}l CD43 ist auf h{\"a}matopoetischen Zellen ubiquit{\"a}r exprimiert und reguliert in T-Zellen deren {\"U}berleben, Proliferation, Aktivierung, Migration und Adh{\"a}sion. P2X3 wird in h{\"a}matopoetischen Zellen nur in geringem Maße exprimiert. Seine funktionelle Bedeutung ist in diesem Kompartiment nicht bekannt. Beide Kandidaten wurden mittels CRISPR/Cas9 Verfahren einzeln oder kombiniert aus Jurkat-T-Zellen ablatiert, welche nachfolgend nach MV-Kontakt hinsichtlich der oben erw{\"a}hnten MV-modulierten Parameter getestet wurden. Zus{\"a}tzlich wurden iso- und allosterische P2X3-Inhibitoren an prim{\"a}ren und Jurkat-T-Zellen verwendet, um dessen Rolle in Ca2+-Mobilisierung und Proliferation nach T-Zell-Rezeptor Co-Stimulation zu analysieren. Die genetische Depletion beider Rezeptor-Kandidaten verringerte die Effekte des MV auf alle getesteten Parameter signifikant, was darauf hindeutet, dass beide Proteine entscheidend an der T-Zell-Suppression beteiligt sind. W{\"a}hrend die isosterische Inhibition von P2X3 keinen Effekt hatte, wurde die Proliferation prim{\"a}rer T-Zellen durch dessen allosterische Inhibition vor Co-Stimulation fast verdoppelt und die Effizienz der Ca2+-Mobilisierung in Jurkat- und prim{\"a}ren T-Zellen signifikant erh{\"o}ht. In P2X3-depletierten Jurkat-Zellen hingegen war die Ca2+-Mobilisierung nach Stimulation signifikant geringer als in WT-Zellen. In dieser Arbeit konnten zwei wichtige Mediatoren der MV induzierten T-Zell-Suppression identifiziert werden. Vor allem P2X3, dessen Expression, Regulation und funktionelle Bedeutung im h{\"a}matopoetischen Kompartiment noch nicht erforscht wurde, k{\"o}nnte ein vielversprechender Kandidat f{\"u}r eine antivirale Therapie darstellen, da ein klinisch getesteter P2X3-Inhibitor bereits verf{\"u}gbar ist.},
  subject      = {Masernvirus},
  language  = {de}
}
@phdthesis{Hartmann2024,
  author    = {Hartmann, Oliver},
  title     = {Development of somatic modified mouse models of Non-Small cell lung cancer},
  doi       = {10.25972/OPUS-36340},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363401},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {In 2020, cancer was the leading cause of death worldwide, accounting for nearly 10 million deaths. Lung cancer was the most common cancer, with 2.21 million cases per year in both sexes. This non-homogeneous disease is further subdivided into small cell lung cancer (SCLC, 15\%) and non-small cell lung cancer (NSCLC, 85\%). By 2023, the American Cancer Society estimates that NSCLC will account for 13\% of all new cancer cases and 21\% of all estimated cancer deaths. In recent years, the treatment of patients with NSCLC has improved with the development of new therapeutic interventions and the advent of targeted and personalised therapies. However, these advances have only marginally improved the five-year survival rate, which remains alarmingly low for patients with NSCLC. This observation highlights the importance of having more appropriate experimental and preclinical models to recapitulate, identify and test novel susceptibilities in NSCLC. In recent years, the Trp53fl/fl KRaslsl-G12D/wt mouse model developed by Tuveson, Jacks and Berns has been the main in vivo model used to study NSCLC. This model mimics ADC and SCC to a certain extent. However, it is limited in its ability to reflect the genetic complexity of NSCLC. In this work, we use CRISPR/Cas9 genome editing with targeted mutagenesis and gene deletions to recapitulate the conditional model. By comparing the Trp53fl/fl KRaslsl- G12D/wt with the CRISPR-mediated Trp53mut KRasG12D, we demonstrated that both showed no differences in histopathological features, morphology, and marker expression. Furthermore, next-generation sequencing revealed a very high similarity in their transcriptional profile. Adeno-associated virus-mediated tumour induction and the modular design of the viral vector allow us to introduce additional mutations in a timely manner. CRISPR-mediated mutation of commonly mutated tumour suppressors in NSCLC reliably recapitulated the phenotypes described in patients in the animal model. Lastly, the dual viral approach could induce the formation of lung tumours not only in constitutive Cas9 expressing animals, but also in wildtype animals. Thus, the implementation of CRISPR genome editing can rapidly advance the repertoire of in vivo models for NSCLC research. Furthermore, it can reduce the necessity of extensive breeding.},
  subject      = {CRISPR/Cas-Methode},
  language  = {en}
}
@phdthesis{Neagoe2024,
  author    = {Neagoe, Raluca Alexandra Iulia},
  title     = {Development of techniques for studying the platelet glycoprotein receptors GPVI and GPIb localisation and signalling},
  doi       = {10.25972/OPUS-31306},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313064},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Platelets play an important role in haemostasis by mediating blood clotting at sites of blood vessel damage. Platelets, also participate in pathological conditions including thrombosis and inflammation. Upon vessel damage, two glycoprotein receptors, the GPIb-IX-V complex and GPVI, play important roles in platelet capture and activation. GPIb-IX-V binds to von Willebrand factor and GPVI to collagen. This initiates a signalling cascade resulting in platelet shape change and spreading, which is dependent on the actin cytoskeleton. This thesis aimed to develop and implement different super-resolution microscopy techniques to gain a deeper understanding of the conformation and location of these receptors in the platelet plasma membrane, and to provide insights into their signalling pathways. We suggest direct stochastic optical reconstruction microscopy (dSTORM) and structured illumination microscopy (SIM) as the best candidates for imaging single platelets, whereas expansion microscopy (ExM) is ideal for imaging platelets aggregates. Furthermore, we highlighted the role of the actin cytoskeleton, through Rac in GPVI signalling pathway. Inhibition of Rac, with EHT1864 in human platelets induced GPVI and GPV, but not GPIbα shedding. Furthermore, EHT1864 treatment did not change GPVI dimerisation or clustering, however, it decreased phospholipase Cγ2 phosphorylation levels, in human, but not murine platelets, highlighting interspecies differences. In summary, this PhD thesis demonstrates that; 1) Rac alters GPVI signalling pathway in human but not mouse platelets; 2) our newly developed ExM protocol can be used to image platelet aggregates labelled with F(ab') fragments},
  subject      = {Platelet-Membranglykoprotein p62},
  language  = {en}
}
@phdthesis{Weisert2024,
  author    = {Weisert, Nadine},
  title     = {Characterization of telomere-associated proteins in \(Trypanosoma\) \(brucei\)},
  doi       = {10.25972/OPUS-35273},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352732},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {The unicellular pathogen Trypanosoma brucei is the causative agent of African trypanosomiasis, an endemic disease prevalent in sub-Saharan Africa. Trypanosoma brucei alternates between a mammalian host and the tsetse fly vector. The extracellular parasite survives in the mammalian bloodstream by periodically exchanging their ˈvariant surface glycoproteinˈ (VSG) coat to evade the host immune response. This antigenic variation is achieved through monoallelic expression of one VSG variant from subtelomeric ˈbloodstream form expression sitesˈ (BES) at a given timepoint. During the differentiation from the bloodstream form (BSF) to the procyclic form (PCF) in the tsetse fly midgut, the stage specific surface protein is transcriptionally silenced and replaced by procyclins. Due to their subtelomeric localization on the chromosomes, VSG transcription and silencing is partly regulated by homologues of the mammalian telomere complex such as TbTRF, TbTIF2 and TbRAP1 as well as by ˈtelomere-associated proteinsˈ (TelAPs) like TelAP1. To gain more insights into transcription regulation of VSG genes, the identification and characterization of other TelAPs is critical and has not yet been achieved. In a previous study, two biochemical approaches were used to identify other novel TelAPs. By using ˈco-immunoprecipitationˈ (co-IP) to enrich possible interaction partners of TbTRF and by affinity chromatography using telomeric repeat oligonucleotides, a listing of TelAP candidates has been conducted. With this approach TelAP1 was identified as a novel component of the telomere complex, involved in the kinetics of transcriptional BES silencing during BSF to PCF differentiation. To gain further insights into the telomere complex composition, other previously enriched proteins were characterized through a screening process using RNA interference to deplete potential candidates. VSG expression profile changes and overall proteomic changes after depletion were analyzed by mass spectrometry. With this method, one can gain insights into the functions of the proteins and their involvement in VSG expression site regulation. To validate the interaction of proteins enriched by co-IP with TbTRF and TelAP1 and to identify novel interaction proteins, I performed reciprocal affinity purifications of the four most promising candidates (TelAP2, TelAP3, PPL2 and PolIE) and additionally confirmed colocalization of two candidates with TbTRF via immunofluorescence (TelAP2, TelAP3). TelAP3 colocalizes with TbTRF and potentially interacts with TbTRF, TbTIF2, TelAP1 and TelAP2, as well as with two translesion polymerases PPL2 and PolIE in BSF. PPL2 and PolIE seem to be in close contact to each other at the telomeric ends and fulfill different roles as only PolIE is involved in VSG regulation while PPL2 is not. TelAP2 was previously characterized to be associated with telomeres by partially colocalizing with TbTRF and cells show a VSG derepression phenotype when the protein was depleted. Here I show that TelAP2 interacts with the telomere-binding proteins TbTRF and TbTIF2 as well as with the telomere-associated protein TelAP1 in BSF and that TelAP2 depletion results in a loss of TelAP1 colocalization with TbTRF in BSF. In conclusion, this study demonstrates that characterizing potential TelAPs is effective in gaining insights into the telomeric complex's composition and its role in VSG regulation in Trypanosoma brucei. Understanding these interactions could potentially lead to new therapeutic targets for combatting African trypanosomiasis.},
  subject      = {Telomer <Molekulargenetik>},
  language  = {en}
}
@phdthesis{Yuan2023,
  author    = {Yuan, Xidi},
  title     = {Aging and inflammation in the peripheral nervous system},
  doi       = {10.25972/OPUS-23737},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-237378},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Aging is known to be a risk factor for structural abnormalities and functional decline in the nervous system. Characterizing age-related changes is important to identify putative pathways to overcome deleterious effects and improve life quality for the elderly. In this study, the peripheral nervous system of 24-month-old aged C57BL/6 mice has been investigated and compared to 12-month-old adult mice. Aged mice showed pathological alterations in their peripheral nerves similar to nerve biopsies from elderly human individuals, with nerve fibers showing demyelination and axonal damage. Such changes were lacking in nerves of adult 12-month-old mice and adult, non-aged humans. Moreover, neuromuscular junctions of 24-month-old mice showed increased denervation compared to adult mice. These alterations were accompanied by elevated numbers of macrophages in the peripheral nerves of aged mice. The neuroinflammatory conditions were associated with impaired myelin integrity and with a decline of nerve conduction properties and muscle strength in aged mice. To determine the pathological impact of macrophages in the aging mice, macrophage depletion was performed in mice by oral administration of CSF-1R specific kinase (c-FMS) inhibitor PLX5622 (300 mg/kg body weight), which reduced the number of macrophages in the peripheral nerves by 70\%. The treated mice showed attenuated demyelination, less muscle denervation and preserved muscle strength. This indicates that macrophage-driven inflammation in the peripheral nerves is partially responsible for the age-related neuropathy in mice. Based on previous observations that systemic inflammation can accelerate disease progression in mouse models of neurodegenerative diseases, it was hypothesized that systemic inflammation can exacerbate the peripheral neuropathy found in aged mice. To investigate this hypothesis, aged C57BL/6 mice were intraperitoneally injected with a single dose of lipopolysaccharide (LPS; 500 μg/kg body weight) to induce systemic inflammation by mimicking bacterial infection, mostly via activation of Toll-like receptors (TLRs). Altered endoneurial macrophage activation, highlighted by Trem2 downregulation, was found in LPS injected aged mice one month after injection. This was accompanied by a so far rarely observed form of axonal perturbation, i.e., the occurrence of "dark axons" characterized by a damaged cytoskeleton and an increased overall electron density of the axoplasm. At the same time, however, LPS injection reduced demyelination and muscle denervation in aged mice. Interestingly, TREM2 deficiency in aged mice led to similar changes to LPS injection. This suggests that LPS injection likely mitigates aging-related demyelination and muscle denervation via Trem2 downregulation. Taken together, this study reveals the role of macrophage-driven inflammation as a pathogenic mediator in age-related peripheral neuropathy, and that targeting macrophages might be an option to mitigate peripheral neuropathies in aging individuals. Furthermore, this study shows that systemic inflammation may be an ambivalent modifier of age-related nerve damage, leading to a distinct type of axonal perturbation, but in addition to functionally counteracting, dampened demyelination and muscle denervation. Translationally, it is plausible to assume that tipping the balance of macrophage polarization to one direction or the other may determine the functional outcome in the aging peripheral nervous system of the elderly.},
  subject      = {Maus},
  language  = {en}
}
@phdthesis{Schwarzmeier2023,
  author    = {Schwarzmeier, Hanna},
  title     = {From fear extinction to exposure therapy: neural mechanisms and moderators of extinction},
  doi       = {10.25972/OPUS-22330},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223304},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Emotional-associative learning processes such as fear conditioning and extinction are highly relevant to not only the development and maintenance of anxiety disorders (ADs), but also to their treatment. Extinction, as the laboratory analogue to behavioral exposure, is assumed a core process underlying the treatment of ADs. Although exposure-based treatments are highly effective for the average patient suffering from an AD, there remains a gap in treatment efficacy with over one third of patients failing to achieve clinically significant symptom relief. There is ergo a pressing need for intensified research regarding the underlying neural mechanisms of aberrant emotional-associative learning processes and the neurobiological moderators of treatment (non-)response in ADs. The current thesis focuses on different applications of the fundamental principles of fear conditioning and extinction by using two example cases of ADs from two different multicenter trials. First, we targeted alterations in fear acquisition, extinction, and its recall as a function of psychopathology in panic disorder (PD) patients compared to healthy subjects using fMRI. Second, exposure-based therapy and pre-treatment patient characteristics exerting a moderating influence on this essential learning process later on (i.e. treatment outcome) were examined using multimodal functional and structural neuroimaging in spider phobia. We observed aberrations in emotional-associative learning processes in PD patients compared to healthy subjects indicated by an accelerated fear acquisition and an attenuated extinction recall. Furthermore, pre-treatment differences related to defensive, regulatory, attentional, and perceptual processes may exert a moderating influence on treatment outcome to behavioral exposure in spider phobia. Although the current results need further replication, on an integrative meta level, results point to a hyperactive defensive network system and deficient emotion regulation processes (including extinction processes) and top-down control in ADs. This speaks in favor of transdiagnostic deficits in important functional domains in ADs. Deficits in transdiagnostic domains such as emotion regulation processes could be targeted by enhancing extinction learning or by means of promising tools like neurofeedback. The detection of pre-treatment clinical response moderators, for instance via machine learning frameworks, may help in supporting clinical decision making on individually tailored treatment approaches or, respectively, to avoid ineffective treatment and its related financial costs. In the long run, the identification of neurobiological markers which are capable of detecting non-responders a priori represents an ultimate goal.},
  subject      = {Extinktion},
  language  = {en}
}
@phdthesis{Kade2023,
  author    = {Kade, Juliane Carolin},
  title     = {Expanding the Processability of Polymers for a High-Resolution 3D Printing Technology},
  doi       = {10.25972/OPUS-27005},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270057},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This thesis identifies how the printing conditions for a high-resolution additive manufacturing technique, melt electrowriting (MEW), needs to be adjusted to process electroactive polymers (EAPs) into microfibers. Using EAPs based on poly(vinylidene difluoride) (PVDF), their ability to be MEW-processed is studied and expands the list of processable materials for this technology.},
  subject      = {Polymere},
  language  = {en}
}
@phdthesis{Reinsberg2023,
  author    = {Reinsberg, Friederike Anna Christine},
  title     = {Die Bedeutung des gp130-Internalisierungmotivs f{\"u}r IL-6-vermittelte Signale und das Antigenpr{\"a}sentationspotential muriner Knochenmarksmakrophagen},
  doi       = {10.25972/OPUS-27705},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-277052},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Interleukin 6 (IL-6) bewirkt als Entz{\"u}ndungsmediator eine autokrine Makrophagen (MΦ) -Stimulation. Zur Verhinderung pathologischer Entz{\"u}ndungsaktivit{\"a}t sind IL-6-Signale stark reguliert, unter anderem durch die Dileucin-vermittelte Endozytose des Signaltransduktors gp130. Klassisches IL-6-Signaling ist abh{\"a}ngig von der Expression von IL-6Rα und gp130 auf der Zelloberfl{\"a}che, w{\"a}hrend IL-6-trans-Signaling durch l{\"o}slichen IL-6Rα nur von der gp130-Expression abh{\"a}ngt. Die Bedeutung des Dileucin-Internalisierungsmotivs f{\"u}r IL-6-vermittelte Signale in MΦ ist jedoch unklar. Ziel der vorliegenden Arbeit war eine Charakterisierung muriner GM-CSF- und M-CSF-ausgereifter Knochenmarks (KM) -MΦ hinsichtlich der Relevanz des gp130-Internalisierungsmotivs f{\"u}r IL-6-vermittelte-Signale. Hierzu wurde die gp130LLAA-Mauslinie als knock in-Modell zur Suppression der gp130-Endozytose verwendet. KM-MΦ entwickeln durch die Ausreifung mittels GM-CSF oder M-CSF einen distinkten Ph{\"a}notyp: M-CSF-ausgereifte KM-MΦ exprimieren mehr gp130 und IL-6Rα auf der Zelloberfl{\"a}che als GM-CSF-ausgereifte KM-MΦ. Dies limitiert sowohl klassisches als auch IL-6-trans-Signaling in GM-CSF-ausgereiften KM-MΦ: IL-6 induziert in diesen eine geringere STAT1-Aktivierung, das IL-6/IL-6Ra-Fusionsprotein hyper-IL-6 eine geringere STAT1- und STAT3-Aktivierung. KM-MΦ aus gp130LLAA-M{\"a}usen exprimieren mehr gp130 als KM-MΦ aus WT-M{\"a}usen bei {\"a}hnlichen Mengen IL-6Rα. Dabei ist die Rezeptorexpression auf gp130LLAA-KM-MΦ unabh{\"a}ngig vom Ausreifungsfaktor GM-CSF oder M-CSF. Durch die erh{\"o}hte gp130-Expression induziert IL-6-trans-Signaling in gp130LLAA-KM-MΦ eine st{\"a}rkere STAT1-Aktivierung als in WT-KM-MΦ, dies gilt insbesondere bei Ausreifung mit GM-CSF. Dagegen sind die STAT3-Aktivierung durch IL-6-trans-Signaling und die STAT1- und STAT3-Aktivierung durch klassisches IL-6-Signaling unabh{\"a}ngig von der Expression des Dileucin-Internalisierungsmotivs. Unklar bleibt, warum IL6-vermittelte Signale in GM-CSF-ausgereiften KM-MΦ st{\"a}rker durch Dileucin-abh{\"a}ngige gp130-Endozytose reguliert werden als in M-CSF-ausgereifte KM-MΦ. Weitere Untersuchungen sind n{\"o}tig.},
  subject      = {Makrophage},
  language  = {de}
}
@phdthesis{LopezCaperuchipi2023,
  author    = {Lopez Caperuchipi, Simon},
  title     = {Charakterisierung zellul{\"a}rer Ver{\"a}nderungen und kognitiver Verhaltensweisen in einem Model vom Sch{\"a}del-Hirn Trauma in m{\"a}nnlichen M{\"a}usen},
  doi       = {10.25972/OPUS-30268},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302686},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Sch{\"a}del-Hirn Trauma ist die f{\"u}hrende Ursache von Tod und Behinderung unter jungen Erwachsenen in den USA und Europa. Dar{\"u}ber hinaus steigert Sch{\"a}del-Hirn Trauma das Risiko eine Demenzerkrankung oder andere neurodegenerative Erkrankung zu erleiden. Aus diesem Grund stellt eine bessere Erkenntnis der subakuten und chronischen pathophysiologischen Prozesse eine wichtige Grundlage f{\"u}r eine m{\"o}gliche zuk{\"u}nftige neuroprotektive Therapie dar. Ziel dieser Arbeit war es daher eine {\"U}bersicht von funktionellen Einschr{\"a}nkungen und zellul{\"a}ren Ver{\"a}nderungen in der subakuten Phase innerhalb der ersten drei Monate darzustellen. Dazu wurden Verhaltensexperimente zu kognitiven Leistungen wie r{\"a}umliches Lernen, kognitive Plastizit{\"a}t, episodisches Ged{\"a}chtnis, Angstverhalten und allgemeine Lokomotion durchgef{\"u}hrt. Dabei konnten funktionale Einschr{\"a}nkungen der Tiere im Bereich der kognitiven Flexibilit{\"a}t, dem r{\"a}umlichen Lernen, dem belohnungsmotivierten Verhalten, sowie Hyperaktivit{\"a}t beobachtet werden. Weiterf{\"u}hrend erfolgten histologische und immunhistologische Untersuchungen an den M{\"a}usegehirnen. So konnten in unserem Tiermodell sowohl lokale neuroinflammatorische Ver{\"a}nderungen nachgewiesen werden, also auch generalisierte Ver{\"a}nderungen, welche sich auf Isocortex und Hippocampus erstreckten und beide Hemisph{\"a}ren gleichermaßen betrafen. Ebenso konnten demyelinisierende Prozesse im Bereich der L{\"a}sion beobachtet werden. Im Bereich des Cortex zeigte sich außerdem eine axonale Sch{\"a}digung mit begleitender Neuroinflammation, sowie eine Infiltration von B-Zellen. Anschließend wurde eruiert, ob eine Korrelation von funktionalem Outcome und histologischen Ver{\"a}nderungen besteht. Dabei zeigte sich eine signifikante Korrelation neuroinflammatorischer Prozesse mit Einschr{\"a}nkungen im r{\"a}umlichen Lernen und Umlernen, sowie Auff{\"a}lligkeiten im Bereich des belohnungsmotivierten Verhaltens. Damit ordnet sich diese Arbeit in die bestehenden Erkenntnisse zur Pathophysiologie des SHTs ein und erg{\"a}nzt diese weiter.},
  subject      = {Sch{\"a}del-Hirn-Trauma},
  language  = {de}
}
@phdthesis{Hapke2023,
  author    = {Hapke, Nils},
  title     = {Cardiac antigen derived T cell epitopes in the frame of myocardial infarction},
  doi       = {10.25972/OPUS-30196},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301963},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Cardiovascular disease and the acute consequence of myocardial infarc- tion remain one of the most important causes of morbidity and mortality in all western societies. While much progress has been made in mitigating the acute, life-threatening ischemia caused by infarction, heart failure of the damaged my- ocardium remains prevalent. There is mounting evidence for the role of T cells in the healing process after myocardial infarction, but relevant autoantigens, which might trigger and regulate adaptive immune involvement have not been discov- ered in patients. In this work, we discovered an autoantigenic epitope in the adrenergic receptor beta 1, which is highly expressed in the heart. This autoantigenic epitope causes a pro-inflammatory immune reaction in T cells isolated from pa- tients after myocardial infarction (MI) but not in control patients. This immune reaction was only observed in a subset of MI patients, which carry at least one allele of the HLA-DRB1*13 family. Interestingly, HLA-DRB1*13 was more com- monly expressed in patients in the MI group than in the control group. Taken together, our data suggests antigen-specific priming of T cells in MI patients, which leads to a pro-inflammatory phenotype. The primed T cells react to a cardiac derived autoantigen ex vivo and are likely to exhibit a similar phenotype in vivo. This immune phenotype was only observed in a certain sub- set of patients sharing a common HLA-allele, which was more commonly ex- pressed in MI patients, suggesting a possible role as a risk factor for cardiovas- cular disease. While our results are observational and do not have enough power to show strong clinical associations, our discoveries provide an essential tool to further our understanding of involvement of the immune system in cardiovascu- lar disease. We describe the first cardiac autoantigen in the clinical context of MI and provide an important basis for further translational and clinical research in cardiac autoimmunity.},
  subject      = {Immunologie},
  language  = {en}
}
@phdthesis{Weiss2023,
  author    = {Weiß, Lukas Johannes},
  title     = {Thrombozytenfunktionsanalyse bei Patienten mit Sepsis},
  doi       = {10.25972/OPUS-30203},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302030},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Sepsis ist eine dysregulierte Reaktion des Organismus auf eine Infektion. Bei Sepsis werden oft Blutungs- und Thromboseereignisse beobachtet, welche in einer Disseminierten Intravasalen Gerinnung (DIG) gipfeln k{\"o}nnen. Thrombozyten sind die Schl{\"u}sselzellen von Thrombose und H{\"a}mostase. Bei Sepsis und DIG kommt es h{\"a}ufig zu einem Abfall der Thrombozytenzahl, doch Blutungs- und Thromboseereignisse k{\"o}nnen unabh{\"a}ngig von der Thrombozytenzahl auftreten, was zus{\"a}tzlich eine Ver{\"a}nderung der Thrombozytenfunktion nahelegt. In dieser Arbeit wurde deshalb die Thrombozytenfunktion bei 15 Patienten mit Sepsis zu drei Zeitpunkten im Krankheitsverlauf untersucht. Es konnte bei unauff{\"a}lliger Rezeptorexpression keine Voraktivierung der Thrombozyten mittels Durchflusszytometrie festgestellt werden. Jedoch war die Aktivierung nach Stimulation mit multiplen Agonisten signifikant reduziert. Besonders ausgepr{\"a}gt war die Hyporeaktivit{\"a}t bei Stimulation des Kollagen-Rezeptors GPVI mit dem Agonisten CRP-XL. Es wurde gezeigt, dass nach GPVI-Stimulation eine reduzierte Phosphorylierung der nachgeschalteten Proteine Syk und LAT im Vergleich zum Gesundspender induziert wird. In Kreuzinkubationsexperimenten hatte die (Co )Inkubation von Thrombozyten in Plasma von Sepsispatienten oder mit Bakterienisolaten aus Sepsis-Blutkulturen keinen Effekt auf die Thrombozytenreaktivit{\"a}t. Allerdings konnte durch Sepsis-Vollblut eine signifikante GPVI-Hyporeaktivit{\"a}t in Thrombozyten von gesunden Probanden induziert werden, was einen zellul{\"a}ren Mediator als Ursache des Defekts nahelegt. In dieser Arbeit wurde gezeigt, dass insbesondere die GPVI-Signalkaskade bei Sepsis massiv beeintr{\"a}chtigt ist. Der Immunorezeptor GPVI ist ein vielversprechendes Zielmolek{\"u}l, um die Pathogenese der Sepsis, des Capillary Leak und die immunregulatorische Rolle von Thrombozyten besser zu verstehen. Die GPVI-Hyporeaktivit{\"a}t k{\"o}nnte als zuk{\"u}nftiger Biomarker f{\"u}r die Sepsis-Fr{\"u}hdiagnose genutzt werden.},
  subject      = {Sepsis},
  language  = {de}
}
@phdthesis{Maier2023,
  author    = {Maier, Sophia Edith},
  title     = {Mapping membrane receptor distribution on resting platelets combining Expansion Microscopy and fluorescence confocal microscopy},
  doi       = {10.25972/OPUS-30031},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300317},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Stroke and myocardial infarction are the most prominent and severe consequences of pathological thrombus formation. For prevention and/or treatment of thrombotic events there is a variety of anti-coagulation and antiplatelet medication that all have one side effect in common: the increased risk of bleeding. To design drugs that only intervene in the unwanted aggregation process but do not disturb general hemostasis, it is crucial to decipher the exact clotting pathway which has not been fully understood yet. Platelet membrane receptors play a vital role in the clotting pathway and, thus, the aim of this work is to establish a method to elucidate the interactions, clustering, and reorganization of involved membrane receptors such as GPIIb/IIIa and GPIX as part of the GPIb-IX-V complex. The special challenges regarding visualizing membrane receptor interactions on blood platelets are the high abundancy of the first and the small size of the latter (1—3µm of diameter). The resolution limit of conventional fluorescence microscopy and even super-resolution approaches prevents the successful differentiation of densely packed receptors from one another. Here, this issue is approached with the combination of a recently developed technique called Expansion Microscopy (ExM). The image resolution of a conventional fluorescence microscope is enhanced by simply enlarging the sample physically and thus pulling the receptors apart from each other. This method requires a complex sample preparation and holds lots of obstacles such as variable or anisotropic expansion and low images contrast. To increase ExM accuracy and sensitivity for interrogating blood platelets, it needs optimized sample preparation as well as image analysis pipelines which are the main part of this thesis. The colocalization results show that either fourfold or tenfold expanded, resting platelets allow a clear distinction between dependent, clustered, and independent receptor organizations compared to unexpanded platelets.Combining dual-color Expansion and confocal fluorescence microscopy enables to image in the nanometer range identifying GPIIb/IIIa clustering in resting platelets - a pattern that may play a key role in the clotting pathway},
  language  = {en}
}
@phdthesis{Fuhr2023,
  author    = {Fuhr, Viktoria},
  title     = {Target Identification and Validation in Ibrutinib-treated Mantle Cell Lymphoma},
  doi       = {10.25972/OPUS-31059},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310595},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Ibrutinib serves as an efficient second-line therapy in relapsed/refractory mantle cell lymphoma. However, resistance to the BTK inhibitor results in a poor prognosis for patients. Since the mechanisms leading to resistance in initially responding tumor cells are poorly understood, this work aimed to decipher acquired features in ibrutinib-surviving cells of a sensitive mantle cell lymphoma cell line and evaluate these potential therapeutic targets in ibrutinib-treated mantle cell lymphoma. Time-resolved single-cell RNA sequencing was performed to track the transcriptomic evolution of REC-1 cells across 6 and 48 hours of treatment. Single-cell analysis uncovered a subpopulation of REC-1 with potentially greater aggressiveness and survival advantage by benefiting from interaction with the tumor microenvironment. Upregulation of B-cell receptor genes, elevated surface antigen expression of CD52 and metabolic rewiring to higher dependence on oxidative phosphorylation were identified as further potential resistance features of ibrutinib-surviving cells. RNA sequencing after prolonged incubation corroborated the increase in CD52 and oxidative phosphorylation as dominant characteristics of the cells surviving the 4-day treatment, highlighting their potential as therapeutic targets in combination with ibrutinib treatment. Concomitant use of ibrutinib and the oxidative phosphorylation inhibitor IACS-010759 increased toxicity compared to ibrutinib monotherapy due to higher apoptosis and greater inhibition of proliferation. For anti-CD52 therapy, a consecutive approach with ibrutinib pretreatment followed by incubation of surviving cells with a CD52 monoclonal antibody and human serum yielded a synergistic effect, as ibrutinib-surviving mantle cell lymphoma cells were rapidly depleted by complement-dependent cytotoxicity. Regarding the effects on primary tumor cells from mantle cell lymphoma patients, ibrutinib induced upregulation of CD52 in some cases, and increased toxicity of anti-CD52 therapy was observed in ibrutinib-sensitive patient samples after pretreatment with the BTK inhibitor. The likely favorable in vivo efficacy of an anti-CD52 therapy might therefore be restricted to a subgroup of mantle cell lymphoma patients, also in view of the associated side effects. Given the need for new therapeutic options in mantle cell lymphoma to overcome resistance to ibrutinib, this work highlights the potentially beneficial use of an oxidative phosphorylation inhibitor as add-on therapy. In addition, the findings suggest to further assess the value of anti-CD52 therapy as consolidation to ibrutinib in ibrutinib-sensitive patients with elevated CD52 surface levels on tumor cells to target resistant clones and minimize risk of minimal residual disease and relapse.},
  subject      = {B-Zell-Lymphom},
  language  = {en}
}
@phdthesis{Nordblom2023,
  author    = {Nordblom, Noah Frieder},
  title     = {Synthese und Evaluation von Gephyrinsonden f{\"u}r hochaufl{\"o}sende Mikroskopieverfahren},
  doi       = {10.25972/OPUS-30230},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302300},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This decade saw the development of new high-end light microscopy approaches. These technologies are increasingly used to expand our understanding of cellular function and the molecular mechanisms of life and disease. The precision of state-of-the-art super resolution microscopy is limited by the properties of the applied fluorescent label. Here I describe the synthesis and evaluation of new functional fluorescent probes that specifically stain gephyrin, universal marker of the neuronal inhibitory post-synapse. Selected probe precursor peptides were synthesised using solid phase peptide synthesis and conjugated with selected super resolution capable fluorescent dyes. Identity and purity were defined using chromatography and mass spectrometric methods. To probe the target specificity of the resulting probe variants in cellular context, a high-throughput assay was established. The established semi-automated and parallel workflow was used for the evaluation of three selected probes by defining their co-localization with the expressed fluorescent target protein. My work provided NN1Dc and established the probe as a visualisation tool for essentially background-free visualisation of the synaptic marker protein gephyrin in a cellular context. Furthermore, NN1DA became part of a toolbox for studying the inhibitory synapse ultrastructure and brain connectivity and turned out useful for the development of a label-free, high-throughput protein interaction quantification assay.},
  subject      = {Fluoreszenzmikroskopie},
  language  = {en}
}
@phdthesis{Haspert2023,
  author    = {Haspert, Valentina},
  title     = {Improving acute pain management with emotion regulation strategies: A comparison of acceptance, distraction, and reappraisal},
  doi       = {10.25972/OPUS-29866},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-298666},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Pain conditions and chronic pain disorders are among the leading reasons for seeking medical help and immensely burden patients and the healthcare system. Therefore, research on the underlying mechanisms of pain processing and modulation is necessary and warranted. One crucial part of this pain research includes identifying resilience factors that protect from chronic pain development and enhance its treatment. The ability to use emotion regulation strategies has been suggested to serve as a resilience factor, facilitating pain regulation and management. Acceptance has been discussed as a promising pain regulation strategy, but results in this domain have been mixed so far. Moreover, the allocation of acceptance in Gross's (1998) process model of emotion regulation has been under debate. Thus, comparing acceptance with the already established strategies of distraction and reappraisal could provide insights into underlying mechanisms. This dissertation project consisted of three successive experimental studies which aimed to investigate these strategies by applying different modalities of individually adjusted pain stimuli of varying durations. In the first study (N = 29), we introduced a within-subjects design where participants were asked to either accept (acceptance condition) or react to the short heat pain stimuli (10 s) without using any pain regulation strategies (control condition). In the second study (N = 36), we extended the design of study 1 by additionally applying brief, electrical pain stimuli (20 ms) and including the new experimental condition distraction, where participants should distract themselves from the pain experience by imagining a neutral situation. In the third study (N = 121), all three strategies, acceptance, distraction, and reappraisal were compared with each other and additionally with a neutral control condition in a mixed design. Participants were randomly assigned to one of three strategy groups, including a control condition and a strategy condition. All participants received short heat pain stimuli of 10 s, alternating with tonic heat pain stimuli of 3 minutes. In the reappraisal condition, participants were instructed to imagine the pain having a positive outcome or valence. The self-reported pain intensity, unpleasantness, and regulation ratings were measured in all studies. We further recorded the autonomic measures heart rate and skin conductance continuously and assessed the habitual emotion regulation styles and pain-related trait factors via questionnaires. Results revealed that the strategies acceptance, distraction, and reappraisal significantly reduced the self-reported electrical and heat pain stimulation with both durations compared to a neutral control condition. Additionally, regulatory efforts with acceptance in study 2 and with all strategies in study 3 were reflected by a decreased skin conductance level compared to the control condition. However, there were no significant differences between the strategies for any of the assessed variables. These findings implicate similar mechanisms underlying all three strategies, which led to the proposition of an extended process model of emotion regulation. We identified another sequence in the emotion-generative process and suggest that acceptance can flexibly affect at least four sequences in the process. Correlation analyses further indicated that the emotion regulation style did not affect regulatory success, suggesting that pain regulation strategies can be learned effectively irrespective of habitual tendencies. Moreover, we found indications that trait factors such as optimism and resilience facilitated pain regulation, especially with acceptance. Conclusively, we propose that acceptance could be flexibly used by adapting to different circumstances. The habitual use of acceptance could therefore be considered a resilience factor. Thus, acceptance appears to be a promising and versatile strategy to prevent the development of and improve the treatment of various chronic pain disorders. Future studies should further examine factors and circumstances that support effective pain regulation with acceptance.},
  subject      = {Schmerzforschung},
  language  = {en}
}
@phdthesis{Portmann2023,
  author    = {Portmann, Johannes},
  title     = {Accelerated inversion recovery MRI of the myocardium using spiral acquisition},
  doi       = {10.25972/OPUS-30282},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302822},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This work deals with the acceleration of cardiovascular MRI for the assessment of functional information in steady-state contrast and for viability assessment during the inversion recovery of the magnetization. Two approaches are introduced and discussed in detail. MOCO-MAP uses an exponential model to recover dynamic image data, IR-CRISPI, with its low-rank plus sparse reconstruction, is related to compressed sensing. MOCO-MAP is a successor to model-based acceleration of parametermapping (MAP) for the application in the myocardial region. To this end, it was augmented with a motion correction (MOCO) step to allow exponential fitting the signal of a still object in temporal direction. Iteratively, this introduction of prior physical knowledge together with the enforcement of consistency with the measured data can be used to reconstruct an image series from distinctly shorter sampling time than the standard exam (< 3 s opposed to about 10 s). Results show feasibility of the method as well as detectability of delayed enhancement in the myocardium, but also significant discrepancies when imaging cardiac function and artifacts caused already by minor inaccuracy of the motion correction. IR-CRISPI was developed from CRISPI, which is a real-time protocol specifically designed for functional evaluation of image data in steady-state contrast. With a reconstruction based on the separate calculation of low-rank and sparse part, it employs a softer constraint than the strict exponential model, which was possible due to sufficient temporal sampling density via spiral acquisition. The low-rank plus sparse reconstruction is fit for the use on dynamic and on inversion recovery data. Thus, motion correction is rendered unnecessary with it. IR-CRISPI was equipped with noise suppression via spatial wavelet filtering. A study comprising 10 patients with cardiac disease show medical applicability. A comparison with performed traditional reference exams offer insight into diagnostic benefits. Especially regarding patients with difficulty to hold their breath, the real-time manner of the IR-CRISPI acquisition provides a valuable alternative and an increase in robustness. In conclusion, especially with IR-CRISPI in free breathing, a major acceleration of the cardiovascular MR exam could be realized. In an acquisition of less than 100 s, it not only includes the information of two traditional protocols (cine and LGE), which take up more than 9.6 min, but also allows adjustment of TI in retrospect and yields lower artifact level with similar image quality.},
  subject      = {Kernspintomografie},
  language  = {en}
}
@phdthesis{Lueffe2023,
  author    = {L{\"u}ffe, Teresa Magdalena},
  title     = {Behavioral and pharmacological validation of genetic zebrafish models for ADHD},
  doi       = {10.25972/OPUS-25716},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257168},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Attention-deficit/hyperactivity disorder (ADHD) is the most prevalent neurodevelopmental disorder described in psychiatry today. ADHD arises during early childhood and is characterized by an age-inappropriate level of inattention, hyperactivity, impulsivity, and partially emotional dysregulation. Besides, substantial psychiatric comorbidity further broadens the symptomatic spectrum. Despite advances in ADHD research by genetic- and imaging studies, the etiopathogenesis of ADHD remains largely unclear. Twin studies suggest a heritability of 70-80 \% that, based on genome-wide investigations, is assumed to be polygenic and a mixed composite of small and large, common and rare genetic variants. In recent years the number of genetic risk candidates is continuously increased. However, for most, a biological link to neuropathology and symptomatology of the patient is still missing. Uncovering this link is vital for a better understanding of the disorder, the identification of new treatment targets, and therefore the development of a more targeted and possibly personalized therapy. The present thesis addresses the issue for the ADHD risk candidates GRM8, FOXP2, and GAD1. By establishing loss of function zebrafish models, using CRISPR/Cas9 derived mutagenesis and antisense oligonucleotides, and studying them for morphological, functional, and behavioral alterations, it provides novel insights into the candidate's contribution to neuropathology and ADHD associated phenotypes. Using locomotor activity as behavioral read-out, the present work identified a genetic and functional implication of Grm8a, Grm8b, Foxp2, and Gad1b in ADHD associated hyperactivity. Further, it provides substantial evidence that the function of Grm8a, Grm8b, Foxp2, and Gad1b in activity regulation involves GABAergic signaling. Preliminary indications suggest that the three candidates interfere with GABAergic signaling in the ventral forebrain/striatum. However, according to present and previous data, via different biological mechanisms such as GABA synthesis, transmitter release regulation, synapse formation and/or transcriptional regulation of synaptic components. Intriguingly, this work further demonstrates that the activity regulating circuit, affected upon Foxp2 and Gad1b loss of function, is involved in the therapeutic effect mechanism of methylphenidate. Altogether, the present thesis identified altered GABAergic signaling in activity regulating circuits in, presumably, the ventral forebrain as neuropathological underpinning of ADHD associated hyperactivity. Further, it demonstrates altered GABAergic signaling as mechanistic link between the genetic disruption of Grm8a, Grm8b, Foxp2, and Gad1b and ADHD symptomatology like hyperactivity. Thus, this thesis highlights GABAergic signaling in activity regulating circuits and, in this context, Grm8a, Grm8b, Foxp2, and Gad1b as exciting targets for future investigations on ADHD etiopathogenesis and the development of novel therapeutic interventions for ADHD related hyperactivity. Additionally, thigmotaxis measurements suggest Grm8a, Grm8b, and Gad1b as interesting candidates for prospective studies on comorbid anxiety in ADHD. Furthermore, expression analysis in foxp2 mutants demonstrates Foxp2 as regulator of ADHD associated gene sets and neurodevelopmental disorder (NDD) overarching genetic and functional networks with possible implications for ADHD polygenicity and comorbidity. Finally, with the characterization of gene expression patterns and the generation and validation of genetic zebrafish models for Grm8a, Grm8b, Foxp2, and Gad1b, the present thesis laid the groundwork for future research efforts, for instance, the identification of the functional circuit(s) and biological mechanism(s) by which Grm8a, Grm8b, Foxp2, and Gad1b loss of function interfere with GABAergic signaling and ultimately induce hyperactivity.},
  language  = {en}
}
@phdthesis{Hanselmann2023,
  author    = {Hanselmann, Steffen},
  title     = {PRC1 serves as a microtubule-bundling protein and is a potential therapeutic target for lung cancer},
  doi       = {10.25972/OPUS-26631},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266314},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Protein regulator of cytokinesis 1 (PRC1) is a microtubule-associated protein with essential roles in mitosis and cytokinesis. Furthermore, the protein is highly expressed in several cancer types which is correlated with aneuploidy and worse patient outcome. In this study it was investigated, whether PRC1 is a potential target for lung cancer as well as its possible nuclear role. Elevated PRC1 expression was cell cycle-dependent with increasing levels from S-phase to G2/M-phase of the cell cycle. Thereby, PRC1 localized at the nucleus during interphase and at the central spindle and midbody during mitosis and cytokinesis. Genome-wide expression profiling by RNA sequencing of ectopically expressed PRC1 resulted in activation of the p53 pathway. A mutant version of PRC1, that is unable to enter the nucleus, induced the same gene sets as wildtype PRC1, suggesting that PRC1 has no nuclear-specific functions in lung cancer cells. Finally, PRC1 overexpression leads to proliferation defects, multi-nucleation, and enlargement of cells which was directly linked to microtubule-bundling within the cytoplasm. For analysis of the requirement of PRC1 in lung cancer, different inducible cell lines were generated to deplete the protein by RNA interference (RNAi) in vitro. PRC1 depletion caused proliferation defects and cytokinesis failures with increased numbers of bi- and multi-nucleated cells compared to non-induced lung cancer cells. Importantly, effects in control cells were less severe as in lung cancer cells. Finally, p53 wildtype lung cancer cells became senescent, whereas p53 mutant cells became apoptotic upon PRC1 depletion. PRC1 is also required for tumorigenesis in vivo, which was shown by using a mouse model for non-small cell lung cancer driven by oncogenic K-RAS and loss of p53. Here, lung tumor area, tumor number, and high-grade tumors were significantly reduced in PRC1 depleted conditions by RNAi. In this study, it is shown that PRC1 serves as a microtubule-bundling protein with essential roles in mitosis and cytokinesis. Expression of the protein needs to be tightly regulated to allow unperturbed proliferation of lung cancer cells. It is suggested that besides phosphorylation of PRC1, the nuclear localization might be a protective mechanism for the cells to prevent perinuclear microtubule-bundling. In conclusion, PRC1 could be a potential target of lung cancer as mono therapy or in combination with a chemotherapeutic agent, like cisplatin, which enhanced the negative effects on proliferation of lung cancer cells in vitro.},
  language  = {en}
}
@phdthesis{Weigl2023,
  author    = {Weigl, Franziska},
  title     = {Correlation of FluidFM® Technology and Fluorescence Microscopy for the Visualization of Cellular Detachment Steps},
  doi       = {10.25972/OPUS-29876},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-298763},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This thesis aimed the development of a correlated device which combines FluidFM® with Fluorescence Microscopy (FL) (FL-FluidFM®) and enables the simultaneous quantification of adhesion forces and fluorescent visualization of mature cells. The implementation of a PIFOC was crucial to achieve a high-resolution as well as a stable but dynamic focus level. The functionality of SCFS after hardware modification was verified by comparing two force-curves, both showing the typical force progression and measured with the optimized and conventional hardware, respectively. Then, the integration of FL was examined by detaching fluorescently labeled REF52 cells. The fluorescence illumination of the cytoskeleton showed the expected characteristic force profile and no evidence of interference effects. Afterwards a corresponding correlative data analysis was addressed including manual force step fitting, the identification of visualized cellular unbinding, and a time-dependent correlation. This procedure revealed a link between the area of cytoskeletal unbinding and force-jumps. This was followed by a comparison of the detachment characteristics of intercellular connected HUVECs and individual REF52 cells. HUVECs showed maximum detachment forces in the same order of magnitude as the ones of single REF52 cells. This contrasted with the expected strong cohesiveness of endothelial cells and indicated a lack of cell-cell contact formation. The latter was confirmed by a comparison of HUVECs, primary HBMVECs, and immortalized EA.hy926 cells fluorescently labeled for two marker proteins of intercellular junctions. This unveiled that both the previous cultivation duration and the cell type have a major impact on the development of intercellular junctions. In summary, the correlative FL FluidFM® represents a powerful novel approach, which enables a truly contemporaneous performance and, thus, has the potential to reveal new insights into the mechanobiological properties of cell adhesion.},
  language  = {en}
}
@phdthesis{Akhrif2023,
  author    = {Akhrif, Atae},
  title     = {The BOLD Signal is more than a Brain Activation Index},
  doi       = {10.25972/OPUS-32287},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322879},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {In the recent years, translational studies comparing imaging data of animals and humans have gained increasing scientific interests with crucial findings stemming from both, human and animal work. In order to harmonize statistical analyses of data from different species and to optimize the transfer of knowledge between them, shared data acquisition protocols and combined statistical approaches have to be identified. Following this idea, methods of data analysis, which have until now mainly been used to model neural responses of electrophysiological recordings from rodent data, were applied on human hemodynamic responses (i.e. Blood-Oxygen-Level- Dependent BOLD signal) as measured via functional magnetic resonance imaging (fMRI). At the example of two attention and impulsivity networks, timing dynamics and amplitude of the fMRI signal were determined (study 1). Study 2 described the same parameters frequency-specifically, and in study 3, the complexity of neural processing was quantified in terms of fractality. Determined parameters were compared with regard to the subjects' task performance / impulsivity to validate findings with regard to reports of the current scientific debate. In a general discussion, overlapping as well as additional information of methodological approaches were discussed with regard to its potential for biomarkers in the context of neuropsychiatric disorders.},
  subject      = {funktionelle Kernspintomographie},
  language  = {en}
}
@phdthesis{Aster2023,
  author    = {Aster, Hans-Christoph},
  title     = {Characterization of subgroups in fibromyalgia syndrome},
  doi       = {10.25972/OPUS-31304},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313049},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {The present cumulative dissertation summarizes three clinical studies, which examine subgroups of patients within the fibromyalgia syndrome (FMS). FMS entails chronic pain and associated symptoms, and its pathophysiology is incompletely understood (1). Previous studies show that there is a subgroup of patients with FMS with objective histological pathology of the small nerve fibers of the peripheral nervous system (PNS). Another subgroup of FMS patients does not show any signs of pathological changes of the small nerve fibers. The aim of this dissertation was to compare FMS patients with healthy controls, and these two FMS subgroups for differences in the central nervous system (CNS) in order to explore possible interactions between PNS and the CNS. Regarding the CNS, differences of FMS patients with healthy controls have already been found in studies with small sample sizes, but no subgroups have yet been identified. Another aim of this thesis was to test whether the subgroups show a different response to different classes of pain medication. The methods used in this thesis are structural and functional magnetic resonance imaging (MRI), magnetic resonance diffusion imaging and magnetic resonance spectroscopy. For the evaluation of clinical symptoms, we used standardized questionnaires. The subgroups with and without pathologies of the PNS were determined by skin biopsies of the right thigh and lower leg based on the intraepidermal nerve fiber density (IENFD) of the small nerve fibers. 1) In the first MRI study, 43 female patients with the diagnosis of FMS and 40 healthy control subjects, matched in age and body mass index, were examined with different MRI sequences. Cortical thickness was investigated by structural T1 imaging, white matter integrity by diffusion tensor imaging and functional connectivity within neuronal networks by functional resting state MRI. Compared to the controls, FMS patients had a lower cortical volume in bilateral frontotemporoparietal regions and the left insula, but a higher cortical volume in the left pericalcarine cortex. Compared to the subgroup without PNS pathology, the subgroup with PNS pathology had lower cortical volume in both pericalcarine cortices. Diffusion tensor imaging revealed an increased fractional anisotropy (FA) of FMS patients in corticospinal pathways such as the corona radiata, but also in regions of the limbic systems such as the fornix and cingulum. Subgroup comparison again revealed lower mean FA values of the posterior thalamic radiation and the posterior limb of the left internal capsule in the subgroup with PNS pathology. In the functional connectivity analysis FMS patients, compared to controls, showed a hypoconnectivity between the right median frontal gyrus and the posterior cerebellum and the right crus cerebellum, respectively. In the subgroup comparisons, the subgroup with PNS pathology showed a hyperconnectivity between both inferior frontal gyri, the right posterior parietal cortex and the right angular gyrus. In summary, these results show that differences in brain morphology and functional connectivity exist between FMS patients with and without PNS pathology. These differences were not associated with symptom duration or severity and, in some cases, have not yet been described in the context of FMS. The differences in brain morphology and connectivity between subgroups could also lead to a differential response to treatment with centrally acting drugs. Further imaging studies with FMS patients should take into account this heterogeneity of FMS patient cohorts. 2) Following the results from the first MRI study, drug therapies of FMS patients and their treatment response were compared between PNS subgroups. As there is no licensed drug for FMS in Europe, the German S3 guideline recommends amitriptyline, duloxetine and pregabalin for temporary use. In order to examine the current drug use in FMS patients in Germany on a cross-sectional basis, 156 patients with FMS were systematically interviewed. The drugs most frequently used to treat pain in FMS were non-steroidal anti-inflammatory drugs (NSAIDs) (28.9\%), metamizole (15.4\%) and amitriptyline (8.8\%). Pain relief assessed by patients on a numerical rating scale from 0-10 averaged 2.2 points for NSAIDs, 2.0 for metamizole and 1.5 for amitriptyline. Drugs that were discontinued for lack of efficacy and not for side effects were acetaminophen (100\%), flupirtine (91.7\%), selective serotonin reuptake inhibitors (81.8\%), NSAIDs (83.7\%) and weak opioids (74.1\%). Patients were divided into subgroups with and without PNS pathology as determined by skin biopsies. We found no differences in drug use and effect between the subgroups. Taken together, these results show that many FMS patients take medication that is not in accordance with the guidelines. The reduction of symptoms was best achieved with metamizole and NSAIDs. Further longitudinal studies on medication in FMS are necessary to obtain clearer treatment recommendations. 3) Derived from previous pharmacological and imaging studies (with smaller case numbers), there is a hypothesis in the FMS literature that hyperreactivity of the insular cortex may have an impact on FMS. The hyperreactivity seems to be due to an increased concentration of the excitatory neurotransmitter glutamate in the insular cortex of FMS patients. The hypothesis is supported by magnetic resonance spectroscopy studies with small number of cases, as well as results from pharmacological studies with glutamate-inhibiting medication. Studies from animal models have also shown that an artificially induced increase in glutamate in the insular cortex can lead to reduced skin innervation. Therefore, the aim of this study was to compare glutamate and GABA concentrations in the insular cortex of FMS patients with those of healthy controls using magnetic resonance imaging. There was no significant difference of both neurotransmitters between the groups. In addition, there was no correlation between the neurotransmitter concentrations and the severity of clinical symptoms. There were also no differences in neurotransmitter concentrations between the subgroups with and without PNS pathology. In conclusion, our study could not show any evidence of a correlation of glutamate and GABA concentrations with the symptoms of FMS or the pathogenesis of subgroups with PNS pathologies.},
  subject      = {Fibromyalgie},
  language  = {en}
}
@phdthesis{Nguyen2023,
  author    = {Nguyen, Tu Anh Thi},
  title     = {Neural coding of different visual cues in the monarch butterfly sun compass},
  doi       = {10.25972/OPUS-30380},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303807},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Monarch butterflies are famous for their annual long-distance migration. Decreasing temperatures and reduced daylight induce the migratory state in the autumn generation of monarch butterflies. Not only are they in a reproductive diapause, they also produce fat deposits to be prepared for the upcoming journey: Driven by their instinct to migrate, they depart from their eclosion grounds in the northern regions of the North American continent and start their southern journey to their hibernation spots in Central Mexico. The butterflies cover a distance of up to 4000 km across the United States. In the next spring, the same butterflies invert their preferred heading direction due to seasonal changes and start their northward spring migration. The spring migration is continued by three consecutive butterfly generations, until the animals repopulate the northern regions in North America as non-migratory monarch butterflies. The monarch butterflies' migratory state is genetically and epigenetically regulated, including the directed flight behavior. Therefore, the insect's internal compass system does not only have to encode the butterflies preferred, but also its current heading direction. However, the butterfly's internal heading representation has to be matched to external cues, to avoid departing from its initial flight path and increasing its risk of missing its desired destination. During the migratory flight, visual cues provide the butterflies with reliable orientation information. The butterflies refer to the sun as their main orientation cue. In addition to the sun, the butterflies likely use the polarization pattern of the sky for orientation. The sky compass signals are processed within a region in the brain, termed the central complex (CX). Previous research on the CX neural circuitry of the monarch butterflies demonstrated that tangential central complex neurons (TL) carry the visual input information into the CX and respond to a simulated sun and polarized light. However, whether these cells process additional visual cues like the panoramic skyline is still unknown. Furthermore, little is known about how the migratory state affects visual cue processing. In addition to this, most experiments studying the monarch butterfly CX focused on how neurons process single visual cues. However, how combined visual stimuli are processed in the CX is still unknown. This thesis is investigating the following questions: 1) How does the migratory state affect visual cue processing in the TL cells within the monarch butterfly brain? 2) How are multiple visual cues integrated in the TL cells? 3) How is compass information modulated in the CX? To study these questions, TL neurons from both animal groups (migratory and non-migratory) were electrophysiologically characterized using intracellular recordings while presenting different simulated celestial cues and visual sceneries. I showed that the TL neurons of migratory butterflies are more narrowly tuned to the sun, possibly helping them in keeping a directed flight course during migration. Furthermore, I found that TL cells encode a panoramic skyline, suggesting that the CX network combines celestial and terrestrial information. Experiments with combined celestial stimuli revealed that the TL cells combine both cue information linearly. However, if exposing the animals to a simulated visual scenery containing a panoramic skyline and a simulated sun, the single visual cues are weighted differently. These results indicate that the CX's input region can flexibly adapt to different visual cue conditions. Furthermore, I characterize a previously unknown neuron in the monarch butterfly CX which responds to celestial stimuli and connects the CX with other brain neuropiles. How this cell type affects heading direction encoding has yet to be determined.},
  subject      = {Monarchfalter},
  language  = {en}
}
@phdthesis{Fleischer2023,
  author    = {Fleischer, Anna},
  title     = {Durchf{\"u}hrbarkeit und diagnostische Genauigkeit der tragbaren Echokardiographie am Krankenbett von Patienten und Patientinnen mit isch{\"a}mischem Schlaganfall auf Stroke Unit - eine Pilotstudie},
  doi       = {10.25972/OPUS-29654},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-296547},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Beinahe jeder dritte isch{\"a}mische Schlaganfall ist urs{\"a}chlich auf Erkrankungen des Herzens zur{\"u}ckzuf{\"u}hren. Daher empfehlen Leitlinien allen Patienten und Patientinnen, bei denen eine kardioembolische {\"A}tiologie des Schlaganfalls vermutet wird und bei denen ein Vorhofflimmern nicht bereits bekannt ist, als Teil der Routinediagnostik eine echokardiographische Untersuchung, um Hinweise auf die {\"A}tiologie des isch{\"a}mischen Schlaganfalls zu gewinnen und um gegebenenfalls Maßnahmen zur Sekund{\"a}rpr{\"a}vention einleiten zu k{\"o}nnen. Jedoch ist der Zugang zu solchen echokardiographischen Untersuchungen oftmals limitiert, besonders f{\"u}r Patienten und Patientinnen auf Stroke Units, denn dort {\"u}berschreitet die Nachfrage h{\"a}ufig die verf{\"u}gbaren personellen und instrumentellen Kapazit{\"a}ten. Zudem stellt der Transport bettl{\"a}geriger Patienten und Patientinnen in andere Abteilungen eine Belastung dar. Daher stellt sich die Frage, ob zuk{\"u}nftig im Rahmen wissenschaftlicher Studien POC-Echokardiographie-Ger{\"a}te zur Diagnostik bestimmter Herzerkrankungen einschließlich einer systolischen Dysfunktion bei Patienten und Patientinnen mit isch{\"a}mischem Schlaganfall eingesetzt werden k{\"o}nnen, mit dem Ziel Patienten und Patientinnen zu identifizieren, die von einer erweiterten echokardiographischen Untersuchung profitieren k{\"o}nnten. Im Rahmen der vorliegenden prospektiven Validierungsstudie untersuchte eine Studentin 78 Patienten und Patientinnen mit akutem isch{\"a}mischem Schlaganfall mithilfe eines POC-Echokardiographie-Ger{\"a}ts auf der Stroke Unit der Neurologischen Abteilung des Universit{\"a}tsklinikums W{\"u}rzburg. Im Anschluss daran erhielten alle 78 Patienten und Patientinnen eine Kontrolluntersuchung durch eine erfahrene Echokardiographie-Raterin mithilfe eines SE-Ger{\"a}ts in einem externen Herzzentrum. Die diagnostischen Qualit{\"a}ten des POC-Echokardiographie-Ger{\"a}ts f{\"u}r Forschungszwecke zur fokussierten kardialen Diagnostik nach isch{\"a}mischem Schlaganfall im Vergleich zu einer SE-Untersuchung konnten mithilfe der Validierungsstudie best{\"a}tigt werden. Es zeigte sich insbesondere, dass die POC-Echokardiographie f{\"u}r die Detektion einer LVEF≤55\% mit einer Sensitivit{\"a}t von 100\% geeignet war. Um zu evaluieren, ob sich das POC-Echokardiographie-Ger{\"a}t in Zukunft auch in der klinischen Praxis als Screeninginstrument eignet, mit dem Ziel eine individuelle Behandlung von Schlaganfallpatienten und -patientinnen zu gew{\"a}hrleisten, m{\"u}ssen gr{\"o}ßere, prospektive Studien durchgef{\"u}hrt werden, in denen die Fallzahl f{\"u}r bestimmte kardiologische Erkrankungen ausreichend hoch ist.},
  subject      = {Schlaganfall},
  language  = {de}
}
@phdthesis{Rumpf2023,
  author    = {Rumpf, Florian},
  title     = {Optogenetic stimulation of AVP neurons in the anterior hypothalamus promotes wakefulness},
  doi       = {10.25972/OPUS-31549},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-315492},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {The mammalian central clock, located in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus, controls circadian rhythms in behaviour such as the sleep-wake cycle. It is made up of approximately 20,000 heterogeneous neurons that can be classified by their expression of neuropeptides. There are three major populations: AVP neurons (arginine vasopressin), VIP neurons (vasoactive intestinal peptide), and GRP neurons (gastrin releasing peptide). How these neuronal clusters form functional units to govern various aspects of rhythmic behavior is poorly understood. At a molecular level, biological clocks are represented by transcriptional-posttranslational feedback loops that induce circadian oscillations in the electrical activity of the SCN and hence correlate with behavioral circadian rhythms. In mammals, the sleep wake cycle can be accurately predicted by measuring electrical muscle and brain activity. To investigate the link between the electrical activity of heterogeneous neurons of the SCN and the sleep wake cycle, we optogenetically manipulated AVP neurons in vivo with SSFO (stabilized step function opsin) and simultaneously recorded an electroencephalogram (EEG) and electromyogram (EMG) in freely moving mice. SSFO-mediated stimulation of AVP positive neurons in the anterior hypothalamus increased the total amount of wakefulness during the hour of stimulation. Interestingly, this effect led to a rebound in sleep in the hour after stimulation. Markov chain sleep-stage transition analysis showed that the depolarization of AVP neurons through SSFO promotes the transition from all states to wakefulness. After the end of stimulation, a compensatory increase in transitions to NREM sleep was observed. Ex vivo, SSFO activation in AVP neurons causes depolarization and modifies the activity of AVP neurons. Therefore, the results of this thesis project suggest an essential role of AVP neurons as mediators between circadian rhythmicity and sleep-wake behaviour.},
  subject      = {Schlaf},
  language  = {en}
}
@phdthesis{Solvie2023,
  author    = {Solvie, Daniel Alexander},
  title     = {Molecular Mechanisms of MYC as Stress Resilience Factor},
  doi       = {10.25972/OPUS-30539},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305398},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Cancer is one of the leading causes of death worldwide. The underlying tumorigenesis is driven by the accumulation of alterations in the genome, eventually disabling tumor suppressors and activating proto-oncogenes. The MYC family of proto-oncogenes shows a strong deregulation in the majority of tumor entities. However, the exact mechanisms that contribute to MYC-driven oncogenesis remain largely unknown. Over the past decades, the influence of the MYC protein on transcription became increasingly apparent and was thoroughly investigated. Additionally, in recent years several publications provided evidence for so far unreported functions of MYC that are independent of a mere regulation of target genes. These findings suggest an additional role of MYC in the maintenance of genomic stability and this role is strengthened by key findings presented in this thesis. In the first part, I present data revealing a pathway that allows MYC to couple transcription elongation and DNA double-strand break repair, preventing genomic instability of MYC-driven tumor cells. This pathway is driven by a rapid transfer of the PAF1 complex from MYC onto RNAPII, a process that is mediated by HUWE1. The transfer controls MYC-dependent transcription elongation and, simultaneously, the remodeling of chromatin structure by ubiquitylation of histone H2B. These regions of open chromatin favor not only elongation but also DNA double-strand break repair. In the second part, I analyze the ability of MYC proteins to form multimeric structures in response to perturbation of transcription and replication. The process of multimerization is also referred to as phase transition. The observed multimeric structures are located proximal to stalled replication forks and recruit factors of the DNA-damage response and transcription termination machinery. Further, I identified the HUWE1-dependent ubiquitylation of MYC as an essential step in this phase transition. Cells lacking the ability to form multimers display genomic instability and ultimately undergo apoptosis in response to replication stress. Both mechanisms present MYC as a stress resilience factor under conditions that are characterized by a high level of transcriptional and replicational stress. This increased resilience ensures oncogenic proliferation. Therefore, targeting MYC's ability to limit genomic instability by uncoupling transcription elongation and DNA repair or disrupting its ability to multimerize presents a therapeutic window in MYC-dependent tumors.},
  subject      = {MYC},
  language  = {en}
}
@phdthesis{Sauerwein2023,
  author    = {Sauerwein, Till},
  title     = {Implementation and application of bioinformatical software for the analysis of dual RNA sequencing data of host and pathogen during infection},
  doi       = {10.25972/OPUS-30307},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303075},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Since the advent of high-throughput sequencing technologies in the mid-2010s, RNA se- quencing (RNA-seq) has been established as the method of choice for studying gene expression. In comparison to microarray-based methods, which have mainly been used to study gene expression before the rise of RNA-seq, RNA-seq is able to profile the entire transcriptome of an organism without the need to predefine genes of interest. Today, a wide variety of RNA-seq methods and protocols exist, including dual RNA sequenc- ing (dual RNA-seq) and multi RNA sequencing (multi RNA-seq). Dual RNA-seq and multi RNA-seq simultaneously investigate the transcriptomes of two or more species, re- spectively. Therefore, the total RNA of all interacting species is sequenced together and only separated in silico. Compared to conventional RNA-seq, which can only investi- gate one species at a time, dual RNA-seq and multi RNA-seq analyses can connect the transcriptome changes of the species being investigated and thus give a clearer picture of the interspecies interactions. Dual RNA-seq and multi RNA-seq have been applied to a variety of host-pathogen, mutualistic and commensal interaction systems. We applied dual RNA-seq to a host-pathogen system of human mast cells and Staphylo- coccus aureus (S. aureus). S. aureus, a commensal gram-positive bacterium, can become an opportunistic pathogen and infect skin lesions of atopic dermatitis (AD) patients. Among the first immune cells S. aureus encounters are mast cells, which have previously been shown to be able to kill the bacteria by discharging antimicrobial products and re- leasing extracellular traps made of protein and deoxyribonucleic acid (DNA). However, S. aureus is known to evade the host's immune response by internalizing within mast cells. Our dual RNA-seq analysis of different infection settings revealed that mast cells and S. aureus need physical contact to influence each other's gene expression. We could show that S. aureus cells internalizing within mast cells undergo profound transcriptome changes to adjust their metabolism to survive in the intracellular niche. On the host side, we found out that infected mast cells elicit a type-I interferon (IFN-I) response in an autocrine manner and in a paracrine manner to non-infected bystander-cells. Our study provides the first evidence that mast cells are capable to produce IFN-I upon infection with a bacterial pathogen.},
  subject      = {Biologie},
  language  = {en}
}
@phdthesis{Engelmann2023,
  author    = {Engelmann, Daria Marie},
  title     = {Regulation of Mammalian Phosphoglycolate Phosphatase},
  doi       = {10.25972/OPUS-19957},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199577},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Mammalian phoshoglycolate phosphatase (PGP, also known as AUM) belongs to the ubiquitous HAD superfamily of phosphatases. As several other members of HAD phosphatases, the Mg2+-dependent dephosphorylation is conducted via a nucleophilic attack from a conserved aspartate residue in the catalytic cleft. The protein structure of PGP could not yet be solved entirely. Only a hybrid consisting of the PGP cap and the PDXP core (pyridoxal phosphatase, closest enzyme paralog) was crystallizable so far. PGP is able to efficiently dephosphorylate 2-phosphoglycolate, 2-phospho-L-lactate, 4-phospho-D-erythronate, and glycerol-3-phosphate in vitro which makes them likely physiological substrates. The first three substrates can be derived from metabolic side reactions (during glycolysis) and inhibit key enzymes in glycolysis and pentose phosphate pathway, the latter is situated at the intersection between glycolysis and lipogenesis. 2-phosphoglycolate can also be released in the context of repair of oxidative DNA damage. The activity of purified PGP can be reversibly inhibited by oxidation - physiologically likely in association with epidermal growth factor (EGF) signal transduction. In fact, an association between persistently lacking PGP activity (via downregulation) and the presence of hyperphosphorylated proteins after EGF stimulation has been identified. Reversible oxidation and transient inactivation of PGP may be particularly important for short-term and feedback regulatory mechanisms (as part of the EGF signaling). Furthermore, cellular proliferation in PGP downregulated cells is constantly reduced. Whole-body PGP inactivation in mice is embryonically lethal. Despite the many well-known features and functions, the knowledge about PGP is still incomplete. In the present work the influence of reactive oxygen species (ROS) on PGP activity in cells und a possible connection between oxidative stress and the proliferation deficit of PGP downregulated cells was investigated. For the experiments, a spermatogonial cell line was used (due to the high PGP expression in testis). PGP activity can be reversibly inhibited in cellular lysates by H2O2 (as a ROS representative). Reversible oxidation could thus indeed be physiologically important. More oxidative DNA damage (by bleomycin) showed no PGP-dependent effects here. EGF stimulation (as an inducer of transient and well-controlled ROS production), low concentrations of menadione (as an oxidant) and N-acetylcysteine (as an antioxidant) were able to approximate the proliferation rate in PGP downregulated cells to that of control cells. The redox regulation of PGP could thus have an influence on cellular proliferation as a feedback mechanism - a mechanism that could not take place in PGP downregulated cells. However, the connections are probably even more complex and cannot be elucidated by a sole examination of the proliferation rate. The present results can thus only be regarded as preliminary experiments. For a better understanding of the features and functions of PGP, this work then focused on specific regulation of enzyme activity by pharmacologically applicable small molecules. Four potent inhibitors had previously been identified in a screening campaign. In this work, three of these four inhibiting compounds could be further characterized in experiments with highly purified, recombinant murine and human PGP. Compounds \#2 and \#9 showed competitive inhibition properties with a markedly rising KM value with little or no change in vmax. The results were consistent for all tested protein variants: the murine and the human PGP as well as a PGP/PDXP hybrid protein. Compound \#1 was the most potent and interesting PGP-inhibitory molecule: less change in KM and a constant decrease in vmax as well as a lower impact on the PGP/PDXP hybrid hint at a mixed mode of inhibition as a combination of competitive and non-competitive inhibition. The characterization of the potential inhibitors can serve as a basis for further structural analysis and studies on the complex physiological role of PGP.},
  subject      = {Phosphoglykolatphosphatase},
  language  = {en}
}
@phdthesis{Behnke2023,
  author    = {Behnke, Jennifer Kim},
  title     = {Charakterisierung der Krankheitsprogression im genetischen hm\(^2\)α-SYN-39 Mausmodell des Morbus Parkinson},
  doi       = {10.25972/OPUS-30204},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302040},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {In dieser Arbeit wurde die Krankheitsprogression im Parkinson-Mausmodell hm2α-SYN-39 mit zunehmendem Alter charakterisiert. Die M{\"a}use wurden in 4 Altersgruppen (2-3, 7-8, 11-12, 16-17 Monate) mit motorischen Verhaltenstests auf einen Parkinson-Ph{\"a}notyp untersucht. Zudem erfolgten Untersuchungen des dopaminergen Systems zur Detektion von neurochemischen Ver{\"a}nderungen und einer Neurodegeneration im nigrostriatalen Trakt. Weiterhin wurden neuroinflammatorische Prozesse des adaptiven und angeborenen IS in der SN und im Striatum mittels immunhistochemischer F{\"a}rbungen beurteilt. Ein Parkinson-Ph{\"a}notyp in diesem Mausmodell zeigte sich nur leicht ausgepr{\"a}gt, sodass der Rotarod- und Zylinder-Test lediglich den Hinweis auf eine nicht-signifikante Einschr{\"a}nkung der Motorik erbrachte. Dennoch ergab die stereologische Quantifizierung TH- und Nissl-positiver Zellen in der SNpc der hm2α-SYN-39 M{\"a}use eine altersabh{\"a}ngige, signifikant-progrediente Reduktion der dopaminergen Neurone mit zunehmendem Alter. Eine signifikant niedrigere TH-positive Zellzahl dieser tg M{\"a}use zeigte sich ab einem Alter von 16-17 Monaten verglichen zu gleichaltrigen wt Tieren. Dagegen war die Neurodegeneration im Striatum etwas weniger ausgepr{\"a}gt. Die tg M{\"a}use pr{\"a}sentierten im Alter von 16-17 Monaten eine nicht-signifikante Erniedrigung der dopaminergen Terminalen verglichen zu gleichaltrigen wt Tieren. Ein DA-Mangel im Striatum der tg M{\"a}use konnte mittels HPLC best{\"a}tigt werden. Bis zum Alter von 16-17 Monaten wurde eine signifikante Reduktion der DA-Level von 23,2 \% verglichen zu gleichaltrigen wt M{\"a}usen gezeigt. Außerdem erniedrigt waren die striatalen Level von NA und 5-HAT bei tg M{\"a}usen, passend zu den bisherigen Ergebnissen bei Parkinson-Patienten. Immunhistochemische Untersuchungen einer Neuroinflammation im nigrostriatalen Trakt ergaben eine tendenziell erh{\"o}hte Infiltration von CD4- und CD8-positiven T-Zellen bei hm2α-SYN-39 M{\"a}usen mit zunehmendem Alter, wobei die Infiltration CD8-positiver Zellen ausgepr{\"a}gter war als bei CD4-positiven Zellen. Eine noch deutlichere neuroinflammatorische Reaktion zeigte das angeborene IS. Hierbei ergab die immunhistologische Quantifizierung CD11b-positiver mikroglialer Zellen einen hochsignifikanten Anstieg im nigrostriatalen Trakt bei hm2α-SYN-39 M{\"a}usen schon im jungen Alter. Zusammenfassend pr{\"a}sentierte dieses Parkinson-Mausmodell eine langsam-progrediente Parkinson-Pathologie mit begleitender Neuroinflammation im nigrostriatalen Trakt w{\"a}hrend des Alterns, wobei die Immunantwort der mikroglialen Zellen zu einem fr{\"u}heren Zeitpunkt einsetzte als die T-Zellinfiltration und Neurodegeneration. Dieses Mausmodell bietet zahlreiche M{\"o}glichkeiten zur zuk{\"u}nftigen Erforschung der Pathophysiologie beim MP. Generell weist diese Arbeit auf eine bedeutende Rolle neuroinflammatorischer Prozesse in der Krankheitsprogression der Parkinsonerkrankung hin und soll dazu ermutigen Neuroinflammation durchaus intensiver in tg Tiermodellen zu untersuchen.},
  subject      = {Parkinson-Krankheit},
  language  = {de}
}
@phdthesis{Diebold2023,
  author    = {Diebold, Mathias},
  title     = {Virtuelles Screening und Entwicklung selektiver Liganden des Aurora-A - MYCN Komplexes und computergest{\"u}tzte Methoden zur Analyse und Design von PROTACs},
  doi       = {10.25972/OPUS-31759},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317594},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Die Interaktion des onkogenen Transkriptionsfaktors MYCN mit der Ser/Thr Kinase Aurora-A verhindert dessen Abbau {\"u}ber das Ubiquitin Proteasomsystem indem die Rekrutierung des SCF FbxW7 Komplexes verhindert wird. Die Kinase nimmt mit der Bindung an MYCN eine aktive Konformation ein und erh{\"a}lt somit die F{\"a}higkeit zur Kinaseaktivit{\"a}t ohne die sonst notwendige Phosphorylierung von Thr288 oder die Anwesenheit eines Aktivators wie TPX2. Da hohe MYCN Konzentrationen Tumore wie Neuroblastome antreiben, ist die St{\"o}rung der Komplexbildung mit Aurora-A eine valide Strategie zur Entwicklung von Chemotherapeutika. Einige Inhibitoren von Aurora-A wie Alisertib (MLN8237) sind in der Lage, eine Konformations{\"a}nderung in der Kinase zu verursachen, die mit der Bindung von MYCN inkompatibel ist und auf diese Weise den Abbau des Transkriptionsfaktors induziert. Da Aurora-A wichtige Funktionen in der Mitose {\"u}bernimmt, k{\"o}nnte eine direkte Adressierung des Komplexes anstelle einer systemischen Inhibition der Kinase vielversprechender sein. Ziel des Projektes war die Identifizierung von Molek{\"u}len, die selektiv an das Interface des Aurora-A - MYCN Komplexes binden und weiter optimiert werden k{\"o}nnen, um einen gezielten Abbau des Transkriptionsfaktors {\"u}ber einen PROTAC Ansatz zu erm{\"o}glichen. Virtuelle Screenings und molekulardynamische Simulationen wurden durchgef{\"u}hrt, um kommerziell erh{\"a}ltliche Verbindungen zu identifizieren, welche mit einer Bindetasche des Komplexes interagieren, die nur zustande kommt, wenn beide Proteine miteinander interagieren. Aus einem ersten Set von zehn potentiellen Liganden wurde f{\"u}r vier eine selektive Interaktion mit dem Protein - Protein Komplex gegen{\"u}ber Aurora-A oder MYCN alleine in STD-NMR Experimenten best{\"a}tigt. Zwei der Hits besaßen ein identisches Grundger{\"u}st und wurden als Ausganspunkt f{\"u}r die Optimierung zu potenteren Liganden genutzt. Das Ger{\"u}st wurde fragmentweise vergr{\"o}ßert und in Richtung besserer in-silico Ergebnisse und Funktionalisierung zur Anbringung von E3-Ligase-Liganden optimiert. Neun dieser Liganden der zweiten Generation wurden synthetisiert. Um quantitative Bindungsdaten zu erhalten, wurde ein kovalent verkn{\"u}pftes Aurora-A - MYCN Konstrukt entworfen. Die strukturelle und funktionale Integrit{\"a}t wurde in STD-NMR und BLI Experimenten mit bekannten Aurora-A Inhibitoren best{\"a}tigt, sowie in NMR-basierten ATPase Assays. Zus{\"a}tzlich konnte die Kristallstruktur des Konstrukts gel{\"o}st und damit die Validit{\"a}t des Designs best{\"a}tigt werden. Quantitative Messungen der synthetisierten Molek{\"u}le identifizierten HD19S als Hit mit einer zehnfach h{\"o}heren Affinit{\"a}t f{\"u}r das Aurora-A - MYCN Konstrukt im Vergleich zu der Kinase allein. Zus{\"a}tzlich wurden in-silico Untersuchungen zu PROTACs der Aurora-A Kinase durchgef{\"u}hrt. Interaktionen zwischen Aurora-A, der E3-Ligase Cereblon und den Liganden wurden modelliert und f{\"u}r die Erkl{\"a}rung unterschiedlicher Aktivit{\"a}ten der eingesetzten PROTACs verwendet. Zudem zeigte das aktivste PROTAC eine hohe Selektivit{\"a}t f{\"u}r Aurora-A gegen{\"u}ber Aurora-B, obwohl die verwendete Erkennungseinheit (Alisertib) an beide Aurora-Proteine bindet. Dieser Umstand konnte durch energetische Analysen von molekulardynamischen Simulationen der tern{\"a}ren Komplexe erkl{\"a}rt werden. Optimierungsm{\"o}glichkeiten f{\"u}r eine effizientere Degradation von Aurora-A durch die PROTACs wurden basierend auf modifizierten Erkennungseinheiten und verbesserten Linkern untersucht.},
  subject      = {Arzneimitteldesign},
  language  = {de}
}
@phdthesis{Wendlinger2023,
  author    = {Wendlinger, Simone Alice},
  title     = {Function of Peripheral Blood Eosinophils in Melanoma},
  publisher = {Cancers (Basel)},
  doi       = {10.25972/OPUS-30119},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301194},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Despite accounting for only a small proportion of all skin cancers, malignant melanoma displays a serious health risk with increasing incidence and high mortality rate. Fortunately, advances in the treatment of malignant melanoma now prolong survival and enhance response and treatment efficacy. Established biomarkers help evaluate disease progression and facilitate choosing appropriate and individual treatment options. However, the need for easily accessible and reliable biomarkers is rising to predict patient-specific clinical outcome. Eosinophil infiltration into the tumor and high peripheral eosinophil counts prior and during treatment have been associated with better response in patients for various cancer entities, including melanoma. An analysis of a heterogeneous study cohort reported high serum ECP levels in non-responders. Hence, eosinophil frequency and serum ECP as a soluble eosinophil-secreted mediator were suggested as prognostic biomarkers in melanoma. We examined whether melanoma patients treated with first-line targeted therapy could also benefit from the effects of eosinophils. In total, 243 blood and serum samples from patients with advanced melanoma were prospectively and retrospectively collected before and after drug initiation. To link eosinophil function to improved clinical outcome, soluble serum markers and peripheral blood counts were used for correlative studies using a homogeneous study cohort. In addition, functional and phenotypical characterizations provided insights into the expression profile and activity of freshly isolated eosinophils, including comparisons between patients and healthy donors. Our data showed a significant correlation between high pre-treatment blood eosinophil counts and improved response to targeted therapy and by trend to combinatorial immunotherapy in patients with metastatic melanoma. In accordance with previous studies our results links eosinophil blood counts to better response in melanoma patients. High pre-treatment ECP serum concentration correlated with response to immunotherapy but not to targeted therapy. Eosinophils from healthy donors and patients showed functional and phenotypical similarities. Functional assays revealed a strong cytotoxic potential of blood eosinophils towards melanoma cells in vitro, inducing apoptosis and necrosis. In addition, in vitro cytotoxicity was an active process of peripheral eosinophils and melanoma cells with bidirectional features and required close cell-cell interaction. The extent of cytotoxicity was dose-dependent and showed susceptibility to changes in physical factors like adherence. Importantly, we provide evidence of an additive tumoricidal function of eosinophils and combinatorial targeted therapy in vitro. In summary, we give valuable insights into the complex and treatment-dependent role of eosinophils in melanoma. As a result, our data support the suggestion of eosinophils and their secreted mediators as potential prognostic biomarkers. It will take additional studies to examine the molecular mechanisms that underlie our findings.},
  subject      = {Melanom},
  language  = {en}
}
@phdthesis{Imam2023,
  author    = {Imam, Nasir},
  title     = {Molecular basis of collybistin conformational activation},
  doi       = {10.25972/OPUS-31145},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311458},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {The nervous system relies on an orchestrated assembly of complex cellular entities called neurons, which are specifically committed to information management and transmission. Inter-neuronal communication takes place via synapses, membrane-membrane junctions which ensure efficient signal transfer. Synaptic neurotransmission involves release of presynaptic neurotransmitters and their reception by cognate receptors at postsynaptic terminals. Inhibitory neurotransmission is primarily mediated by the release of neurotransmitters GABA (γ-Aminobutyric acid) and glycine, which are precisely sensed by GABA type-A receptors (GABAARs) and glycine receptors (GlyRs), respectively. GABAAR assembly and maintenance is coordinated by various postsynaptic neuronal factors including the scaffolding protein gephyrin, the neuronal adaptor collybistin (CB) and cell adhesion proteins of the neuroligin (NL) family, specifically NL2 and NL4. At inhibitory postsynaptic specializations, gephyrin has been hypothesized to form extended structures underneath the plasma membrane, where its interaction with the receptors leads to their stabilization and impedes their lateral movement. Gephyrin mutations have been associated with various brain disorders, including autism, schizophrenia, Alzheimer's disease, and epilepsy. Furthermore, gephyrin loss is lethal and causes mice to die within the first post-natal day. Gephyrin recruitment from intracellular deposits to postsynaptic membranes primarily relies on the adaptor protein CB. As a moonlighting protein, CB, a guanine nucleotide exchange factor (GEF), also catalyzes a nucleotide exchange reaction, thereby regenerating the GTP-bound state of the small GTPase Cdc42 from its GDP-bound form. The CB gene undergoes alternative splicing with the majority of CB splice variants featuring an N-terminal SH3 domain followed by tandem Dbl-homology (DH) and pleckstrin-homology (PH) domains. Previous studies demonstrated that the most widely expressed, SH3-domain containing splice variant (CB2SH3+) preferentially adopts a closed conformation, in which the N-terminally located SH3 domain forms intra-molecular interaction with the DH-PH domain tandem. Previous cell-based studies indicated that SH3 domain-encoding CB variants remain untargeted and colocalize with intracellular gephyrin deposits and hence require additional factors which interact with the SH3 domain, thus inducing an open or active conformation. The SH3 domain-deficient CB isoform (CB2SH3-), on the contrary, adopts an open conformation, which possess enhanced postsynaptic gephyrin-clustering and also effectively replenishes the GTP-bound small GTPase-Cdc42 from its GDP-bound state. Despite the fundamental role of CB as a neuronal adaptor protein maintaining the proper function of inhibitory GABAergic synapses, its interactions with the neuronal scaffolding protein gephyrin and other post synaptic neuronal factors remain poorly understood. Moreover, CB interaction studies with the small GTPase Cdc42 and TC10, a closely related member of Cdc42 subfamily, remains poorly characterized. Most importantly, the roles of the neuronal factors and small GTPases in CB conformational activation have not been elucidated. This PhD dissertation primarily focuses on delineating the molecular basis of the interactions between CB and postsynaptic neuronal factors. During the course of my PhD dissertation, I engineered a series of CB FRET (F{\"o}rster Resonance Energy Transfer) sensors to characterize the CB interaction with its binding partners along with outlining their role in CB conformational activation. Through the aid of these CB FRET sensors, I analyzed the gephyrin-CB interaction, which, due to technical limitations remained unaddressed for more than two decades (refer Chapter 2 for more details). Subsequently, I also unraveled the molecular basis of the interactions between CB and the neuronal cell adhesion factor neuroligin 2 (refer chapter 2) and the small GTPases Cdc42 and TC10 (refer chapter 3) and describe how these binding partners induce a conformational activation of CB. In summary, this PhD dissertation provides strong evidence of a closely knit CB communication network with gephyrin, neuroligin and the small GTPase TC10, wherein CB activation from closed/inactive to open/active states is effectively triggered by these ligands.},
  language  = {en}
}
@phdthesis{Schulte2023,
  author    = {Schulte, Annemarie},
  title     = {\(In\) \(vitro\) reprogramming of glial cells from adult dorsal root ganglia into nociceptor-like neurons},
  doi       = {10.25972/OPUS-30311},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303110},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Plexus injury often occurs after motor vehicle accidents and results in lifelong disability with severe neuropathic pain. Surgical treatment can partially restore motor functions, but sensory loss and neuropathic pain persist. Regenerative medicine concepts, such as cell replacement therapies for restoring dorsal root ganglia (DRG) function, set high expectations. However, up to now, it is unclear which DRG cell types are affected by nerve injury and can be targeted in regenerative medicine approaches. This study followed the hypothesis that satellite glial cells (SGCs) might be a suitable endogenous cell source for regenerative medicine concepts in the DRG. SGCs originate from the same neural crest-derived cell lineage as sensory neurons, making them attractive for neural repair strategies in the peripheral nervous system. Our hypothesis was investigated on three levels of experimentation. First, we asked whether adult SGCs have the potential of sensory neuron precursors and can be reprogrammed into sensory neurons in vitro. We found that adult mouse DRG harbor SGC-like cells that can still dedifferentiate into progenitor-like cells. Surprisingly, expression of the early developmental transcription factors Neurog1 and Neurog2 was sufficient to induce neuronal and glial cell phenotypes. In the presence of nerve growth factor, induced neurons developed a nociceptor-like phenotype expressing functional nociceptor markers, such as the ion channels TrpA1, TrpV1 and NaV1.9. In a second set of experiments, we used a rat model for peripheral nerve injury to look for changes in the DRG cell composition. Using an unbiased deep learning-based approach for cell analysis, we found that cellular plasticity responses after nerve injury activate SGCs in the whole DRG. However, neither injury-induced neuronal death nor gliosis was observed. Finally, we asked whether a severe nerve injury changed the cell composition in the human DRG. For this, a cohort of 13 patients with brachial plexus injury was investigated. Surprisingly, in about half of all patients, the injury-affected DRG showed no characteristic DRG tissue. The complete entity of neurons, satellite cells, and axons was lost and fully replaced by mesodermal/connective tissue. In the other half of the patients, the basic cellular entity of the DRG was well preserved. Objective deep learning-based analysis of large-scale bioimages of the "intact" DRG showed no loss of neurons and no signs of gliosis. This study suggests that concepts for regenerative medicine for restoring DRG function need at least two translational research directions: reafferentation of existing DRG units or full replacement of the entire multicellular DRG structure. For DRG replacement, SGCs of the adult DRG are an attractive endogenous cell source, as the multicellular DRG units could possibly be rebuilt by transdifferentiating neural crest-derived sensory progenitor cells into peripheral sensory neurons and glial cells using Neurog1 and Neurog2.},
  subject      = {Spinalganglion},
  language  = {en}
}
@phdthesis{Saulin2023,
  author    = {Saulin, Anne Christin},
  title     = {Sustainability of empathy as driver for prosocial behavior and social closeness: insights from computational modelling and functional magnetic resonance imaging},
  doi       = {10.25972/OPUS-30555},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305550},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Empathy, the act of sharing another person's affective state, is a ubiquitous driver for helping others and feeling close to them. These experiences are integral parts of human behavior and society. The studies presented in this dissertation aimed to investigate the sustainability and stability of social closeness and prosocial decision-making driven by empathy and other social motives. In this vein, four studies were conducted in which behavioral and neural indicators of empathy sustainability were identified using model-based functional magnetic resonance imaging (fMRI). Applying reinforcement learning, drift-diffusion modelling (DDM), and fMRI, the first two studies were designed to investigate the formation and sustainability of empathy-related social closeness (study 1) and examined how sustainably empathy led to prosocial behavior (study 2). Using DDM and fMRI, the last two studies investigated how empathy combined with reciprocity, the social norm to return a favor, on the one hand and empathy combined with the motive of outcome maximization on the other hand altered the behavioral and neural social decision process. The results showed that empathy-related social closeness and prosocial decision tendencies persisted even if empathy was rarely reinforced. The sustainability of these empathy effects was related to recalibration of the empathy-related social closeness learning signal (study 1) and the maintenance of a prosocial decision bias (study 2). The findings of study 3 showed that empathy boosted the processing of reciprocity-based social decisions, but not vice versa. Study 4 revealed that empathy-related decisions were modulated by the motive of outcome maximization, depending on individual differences in state empathy. Together, the studies strongly support the concept of empathy as a sustainable driver of social closeness and prosocial behavior.},
  subject      = {Einf{\"u}hlung <Motiv>},
  language  = {en}
}
@phdthesis{Lichter2023,
  author    = {Lichter, Katharina},
  title     = {Die Ultrastruktur von Aktiven Zonen in hippocampalen Moosfaserboutons},
  doi       = {10.25972/OPUS-30312},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303126},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {In nervous systems, synapses precisely orchestrate information transfer and memory formation. Active zones (AZ) are specialized subcellular compartments at the presynaptic mesoscale which process synaptic transmission on an ultrastructural level. The AZ cytomatrix including the essential scaffold protein Rab3 interacting molecule (RIM) enables exocytosis of synaptic vesicles. A deficiency of the locally most abundant protein isoform RIM1α diminishes long-term potentiation in a complex central mammalian synapse - the connection of hippocampal mossy fiber boutons (MFB) to cornu ammonis (CA)3 pyramidal neurons. Behaviourally, these mice present with learning impairment. The present MD thesis addresses the so far unknown three-dimensional (3D) AZ ultrastructure of MFBs in acute hippocampal slices of wild-type and RIM1α-/- mice. In a first set of experiments, a standardized protocol for near-to-native synaptic tissue preparation at MFBs using high-pressure freezing and freeze substitution and 3D modelling using electron tomography was developed and established. Based on the excellent preservation of synaptic tissue using this protocol, the AZ ultrastructure in both genotypes was quantified in detail up to an individual docked synaptic vesicle using custom-written programming scripts. The experiments demonstrate that deficiency of RIM1α leads to multidimensional alter-ation of AZ 3D ultrastructure and synaptic vesicle pools in MFBs. (Tightly) docked synaptic vesicles - ultrastructural correlates of the readily releasable pool - are reduced, decentralized, and structurally modified, whereas the more distant vesicle pool clusters more densely above larger and more heterogenous AZ surfaces with higher synaptic clefts. The present thesis contributes to a more comprehensive understanding regarding the role of RIM1α for (tight) vesicle docking and organization at MFBs. Furthermore, the precise 3D ultrastructural analysis of MFB AZs in this thesis provides the necessary mor-phological basis for further studies to correlate synaptic ultrastructure with presynaptic plasticity and memory dysfunction in RIM1α-/- mice using advanced electrophysiological and behavioral techniques.},
  subject      = {Hippocampus},
  language  = {de}
}