@phdthesis{Aboagye2019, author = {Aboagye, Benjamin}, title = {Behavioral and physiologic consequences of inducible inactivation of the \(Tryptophan\) \(hydroxylase\) 2 gene in interaction with early-life adversity}, doi = {10.25972/OPUS-17358}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173581}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Disruptions in brain serotonin (5-hydroxytryptamine, 5-HT) signaling pathways have been associated with etiology and pathogenesis of various neuropsychiatric disorders, but specific neural mechanisms of 5-HT function are yet to be fully elucidated. Tryptophan hydroxylase 2 (TPH2) is the rate-limiting enzyme for brain 5-HT synthesis. Therefore, in this study a tamoxifen (Tam)-inducible cre-mediated conditional gene (Tph2) knockout in adult mouse brain (Tph2icKO) has been established to decipher the specific role of brain 5-HT in the regulation of behavior in adulthood. Immunohistochemistry and high-performance liquid chromatography (HPLC) were used first to test the efficacy of Tam-inducible inactivation of Tph2 and consequential reduction of 5-HT in adult mouse brain. Tam treatment resulted in ≥90\% reduction in the number of 5-HT immuno-reactive cells in the anterior raphe nuclei. HPLC revealed a significant reduction in concentration of 5-HT and its metabolite 5-hydroxyindole acetic acid (5-HIAA) in selected brain regions of Tph2icKO, indicating the effectiveness of the protocol used. Second, standard behavioral tests were used to assess whether reduced brain 5-HT concentrations could alter anxiety-, fear- and depressive-like behavior in mice. No altered anxiety- and depressive-like behaviors were observed in Tph2icKO compared to control mice (Tph2CON) in all indices measured, but Tph2icKO mice exhibited intense and sustained freezing during context-dependent fear memory retrieval. Tph2icKO mice also exhibited locomotor hyperactivity in the aversive environments, such as the open field, and consumed more food and fluid than Tph2CON mice. Lastly, the combined effect of maternal separation (MS) stress and adult brain 5-HT depletion on behavior was assessed in male and female mice. Here, MS stress, 5-HT depletion and their interaction elicited anxiety-like behavior in a sex-dependent manner. MS reduced exploratory behavior in both male and female mice. Reduced 5-HT enhanced anxiety in female, but not in male mice. Furthermore, expression of genes related to the 5-HT system and emotionality (Tph2, Htr1a, Htr2a, Maoa and Avpr1a) was assessed by performing a quantitative real-time PCR. In Tph2icKO mice there was a reduction in expression of Tph2 in the raphe nuclei of both male and female mice. Interaction between MS stress and 5-HT deficiency was detected showing increased Htr2a and Maoa expression in raphe and hippocampus respectively of female mice. In male mice, MS stress and 5-HT depletion interaction effects reduced Avpr1a expression in raphe, while the expression of Htr1a, Htr2a and Maoa was differentially altered by 5-HT depletion and MS in various brain regions.}, subject = {Anxiety}, language = {en} } @phdthesis{Abt2019, author = {Abt, Raimond}, title = {Implementing Aspects of Quantum Information into the AdS/CFT Correspondence}, doi = {10.25972/OPUS-18801}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188012}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {In recent years many discoveries have been made that reveal a close relation between quantum information and geometry in the context of the AdS/CFT correspondence. In this duality between a conformal quantum field theory (CFT) and a theory of gravity on Anti-de Sitter spaces (AdS) quantum information quantities in CFT are associated with geometric objects in AdS. Subject of this thesis is the examination of this intriguing property of AdS/CFT. We study two central elements of quantum information: subregion complexity -- which is a measure for the effort required to construct a given reduced state -- and the modular Hamiltonian -- which is given by the logarithm of a considered reduced state. While a clear definition for subregion complexity in terms of unitary gates exists for discrete systems, a rigorous formulation for quantum field theories is not known. In AdS/CFT, subregion complexity is proposed to be related to certain codimension one regions on the AdS side. The main focus of this thesis lies on the examination of such candidates for gravitational duals of subregion complexity. We introduce the concept of \textit{topological complexity}, which considers subregion complexity to be given by the integral over the Ricci scalar of codimension one regions in AdS. The Gauss-Bonnet theorem provides very general expressions for the topological complexity of CFT\(_2\) states dual to global AdS\(_3\), BTZ black holes and conical defects. In particular, our calculations show that the topology of the considered codimension one bulk region plays an essential role for topological complexity. Moreover, we study holographic subregion complexity (HSRC), which associates the volume of a particular codimension one bulk region with subregion complexity. We derive an explicit field theory expression for the HSRC of vacuum states. The formulation of HSRC in terms of field theory quantities may allow to investigate whether this bulk object indeed provides a concept of subregion complexity on the CFT side. In particular, if this turns out to be the case, our expression for HSRC may be seen as a field theory definition of subregion complexity. We extend our expression to states dual to BTZ black holes and conical defects. A further focus of this thesis is the modular Hamiltonian of a family of states \(\rho_\lambda\) depending on a continuous parameter \(\lambda\). Here \(\lambda\) may be associated with the energy density or the temperature, for instance. The importance of the modular Hamiltonian for quantum information is due to its contribution to relative entropy -- one of the very few objects in quantum information with a rigorous definition for quantum field theories. The first order contribution in \(\tilde{\lambda}=\lambda-\lambda_0\) of the modular Hamiltonian to the relative entropy between \(\rho_\lambda\) and a reference state \(\rho_{\lambda_0}\) is provided by the first law of entanglement. We study under which circumstances higher order contributions in \(\tilde{\lambda}\) are to be expected. We show that for states reduced to two entangling regions \(A\), \(B\) the modular Hamiltonian of at least one of these regions is expected to provide higher order contributions in \(\tilde{\lambda}\) to the relative entropy if \(A\) and \(B\) saturate the Araki-Lieb inequality. The statement of the Araki-Lieb inequality is that the difference between the entanglement entropies of \(A\) and \(B\) is always smaller or equal to the entanglement entropy of the union of \(A\) and \(B\). Regions for which this inequality is saturated are referred to as entanglement plateaux. In AdS/CFT the relation between geometry and quantum information provides many examples for entanglement plateaux. We apply our result to several of them, including large intervals for states dual to BTZ black holes and annuli for states dual to black brane geometries.}, subject = {AdS-CFT-Korrespondenz}, language = {en} } @phdthesis{AdelAbdelrehimMohamedSoliman2019, author = {Adel Abdelrehim Mohamed Soliman, Hadya}, title = {Structural Equation Modeling of Factors Influencing EFL Reading comprehension: Comparative study between Egypt and Germany}, doi = {10.25972/OPUS-18695}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186957}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {In most foreign language learning contexts, there are only rare chance for contact with native speakers of the target language. In such a situation, reading plays an important role in language acquisition as well as in gaining cultural information about the target language and its speakers. Previous research indicated that reading in foreign language is a complex process, which is influenced by various linguistic, cognitive and affective factors. The aim of the present study was to test two structural models of the relationship between reading comprehension in native language (L1), English language (L2) reading motivation, metacognitive awareness of L2 reading strategies, and reading comprehension of English as a foreign language among the two samples. Furthermore, the current study aimed to examine the differences between Egyptian and German students in their perceived usage of reading strategies during reading English texts, as well as to explore the pattern of their motivation toward reading English texts. For this purpose, 401 students were recruited from Germany (n=200) and Egypt (n=201) to participate in the current study. In order to have information about metacognitive awareness of reading strategies, a self-report questionnaire (SORS) developed by Moktari and Sheory (2002) was used. While the L2 reading motivation variable, was measured by a reading motivation survey (L2RMQ) which was based on reviewed reading motivation research. In addition, two reading tests were administrated one to measure reading comprehension for native language (German/Arabic) and the other to measure English reading comprehension. To analyze the collected data, descriptive statistics and independent t-tests were performed. In addition, further analysis using structural equation modeling was applied to test the strength of relationships between the variables under study. The results from the current research revealed that L1 reading comprehension, whether in a German or Arabic language, had the strongest relationship with L2 reading comprehension. However, the relationship between L2 intrinsic reading motivation was not proven to be significant in either the German or Egyptian models. On the other hand, the relationship between L2 extrinsic reading motivation, metacognitive awareness of reading strategies, and L2 reading comprehension was only proven significant in the German sample. The discussion of these results along with their pedagogical implications for education and practice will be illustrated in the following study.}, subject = {Leseverstehen}, language = {en} } @phdthesis{Agnetta2019, author = {Agnetta, Luca}, title = {Novel Photoswitchable and Dualsteric Ligands Acting on Muscarinic Acetylcholine Receptors for Receptor Function Investigation}, doi = {10.25972/OPUS-18717}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187170}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {G protein-coupled receptor research looks out for new technologies to elucidate the complex processes of receptor activation, function and downstream signaling with spatiotemporal resolution, preferably in living cells and organisms. A thriving approach consists in making use of the unsurpassed properties of light, including its high precision in space and time, noninvasiveness and high degree of orthogonality regarding biological processes. This is realized by the incorporation of molecular photoswitches, which are able to effectively respond to light, such as azobenzene, into the structure of a ligand of a given receptor. The muscarinic acetylcholine receptors belong to class A GPCRs and have received special attention in this regard due to their role as a prototypic pharmacological system and their therapeutic potential. They mediate the excitatory and inhibitory effects of the neurotransmitter acetylcholine and thus regulate diverse important biological processes, especially many neurological functions in our brain. In this work, the application of photopharmacological tool compounds to muscarinic receptors is presented, consisting of pharmacophores extended with azobenzene as light-responsive motif. Making use of the dualsteric concept, such photochromic ligands can be designed to bind concomitantly to the orthosteric and allosteric binding site of the receptor, which is demonstrated for BQCAAI (M1) and PAI (M2) and may lead to subtype- and functionalselective photoswitchable ligands, suitable for further ex vivo and in vivo studies. Moreover, photoswitchable ligands based on the synthetic agonist iperoxo were investigated extensively with regard to their photochemical behavior and pharmacological profile, outlining the advantages and challenges of using red-shifted molecular photoswitches, such as tetraortho- fluoro azobenzene. For the first time on a GPCR it was examined, which impact the different substitution pattern has on both the binding and the activity on the M1 receptor. Results show that substituted azobenzenes in photopharmacological compounds (F4-photoiperoxo and F4-iper-azo-iper) not just represent analogs with other photophysical properties but can exhibit a considerably different biological profile that has to be investigated carefully. The achievements gained in this study can give important new insights into the binding mode and time course of activation processes, enabling precise spatial and temporal resolution of the complex signaling pathway of muscarinic receptors. Due to their role as exemplary model system, these findings may be useful for the investigation into other therapeutically relevant GPCRs.}, subject = {Muscarinrezeptor}, language = {en} } @phdthesis{Akakpo2019, author = {Akakpo, Martin Gameli}, title = {The influence of learner characteristics on interactions to seek and share information in e-learning: A media psychology perspective}, doi = {10.25972/OPUS-18593}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-185934}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Research on the deployment and use of technology to assist learning has seen a significant rise over the last decades (Aparicio et al., 2017). The focus on course quality, technology, learning outcome and learner satisfaction in e-learning has led to insufficient attention by researchers to individual characteristics of learners (Cidral et al., 2017 ; Hsu et al., 2013). The current work aims to bridge this gap by investigating characteristics identified by previous works and backed by theory as influential individual differences in e-learning. These learner characteristics have been suggested as motivational factors (Edmunds et al., 2012) in decisions by learners to interact and exchange information (Luo et al., 2017). In this work e-learning is defined as interaction dependent information seeking and sharing enabled by technology. This is primarily approached from a media psychology perspective. The role of learner characteristics namely, beliefs about the source of knowledge (Schommer, 1990), learning styles (Felder \& Silverman, 1988), need for affect (Maio \& Esses, 2001), need for cognition (Cacioppo \& Petty, 1982) and power distance (Hofstede, 1980) on interactions to seek and share information in e-learning are investigated. These investigations were shaped by theory and empirical lessons as briefly mentioned in the next paragraphs. Theoretical support for investigations is derived from the technology acceptance model(TAM) by psychologist Davis (1989) and the hyper-personal model by communication scientist Walther (1996). The TAM was used to describe the influence of learner characteristics on decisions to use e-learning systems (Stantchev et al., 2014). The hyper-personal model described why computer-mediated communication thrives in e-learning (Kaye et al., 2016) and how learners interpret messages exchanged online (Hansen et al., 2015). This theoretical framework was followed by empirical reviews which justified the use of interaction and information seeking-sharing as key components of e-learning as well as the selection of learner characteristics. The reviews provided suggestions for the measurement of variables (K{\"u}hl et al., 2014) and the investigation design (Dascalau et al., 2015). Investigations were designed and implemented through surveys and quasi experiments which were used for three preliminary studies and two main studies. Samples were selected from Germany and Ghana with same variables tested in both countries. Hypotheses were tested with interaction and information seeking-sharing as dependent variables while beliefs about the source of knowledge, learning styles, need for affect, need for cognition and power distance were independent variables. Firstly, using analyses of variance, the influence of beliefs about the source of knowledge on interaction choices of learners was supported. Secondly, the role of need for cognition on interaction choices of learners was supported by results from a logistic regression. Thirdly, results from multiple linear regressions backed the influence of need for cognition and power distance on information seeking-sharing behaviour of learners. Fourthly, the relationship between need for affect and need for cognition was supported. The findings may have implications for media psychology research, theories used in this work, research on e-learning, measurement of learner characteristics and the design of e-learning platforms. The findings suggest that, the beliefs learners have about the source of knowledge, their need for cognition and their power distance can influence decisions to interact and seek or share information. The outlook from reviews and findings in this work predicts more research on learner characteristics and a corresponding intensity in the use of e-learning by individuals. It is suggested that future studies investigate the relationship between learner autonomy and power distance. Studies on inter-cultural similarities amongst e-learners in different populations are also suggested.}, subject = {e-learning}, language = {en} } @phdthesis{ALHijailan2019, author = {AL-Hijailan, Reem Saud}, title = {Establishment of endothelialized cardiac tissue using human induced pluripotent stem cells generated cardiomyocytes}, doi = {10.25972/OPUS-17397}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173979}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Cardiovascular diseases are considered the leading cause of death worldwide according to the World Health Organization. Heart failure is the last stage of most of these diseases, where loss of myocardium leads to architectural and functional decline. The definitive treatment option for patients with CVDs is organ or tissue transplantation, which relies on donor availability. Therefore, generating an autologous bioengineered myocardium or heart could overcome this limitation. In addition, generating cardiac patches will provide ventricular wall support and enable reparative stem cells delivery to damaged areas. Although many hurdles still exist, a good number of researches have attempted to create an engineered cardiac tissue which can induce endogenous cardiac repair by replacing damaged myocardium. The present study provided cardiac patches in two models, one by a detergent coronary perfusion decellularization protocol that was optimized, and the other that resulted in a 3D cell-free extracellular matrix with intact architecture and preserved s-glycosaminoglycan and vasculature conduits. Perfusion with 1\% Sodium dodecyle sulfate (SDS) under constant pressure resulted in cell-free porcine scaffold within two and cell-free rat scaffold in 7 days, whereas scaffold perfused with 4\% sodium deoxycholate (SDO) was not able to remove cells completely. Re-reendothelialization of tissue vasculature was obtained by injecting human microvascular endothelial cell and human fibroblast in 2:1 ratio in a dynamic culture. One-week later, CD31 positive cells and endothelium markers were observed, indicating new blood lining. Moreover, functionality test of re-endothelialized tissue revealed improvement in clotting seen in decellularized tissues. When the tissue was ready to be repopulated, porcine induced pluripotent stem cells (PiPSc) were generated by transfected reprogramming of porcine skin fibroblast and then differentiated to cardiac cells following a robust protocol, for an autologous cardiac tissue model. However, due to the limitation in the PiPSc cell number, alternatively, human induced pluripotent stem cells generated cardiac cells were used. For reseeding a coculture of human iPSc generated cardiac cells, human mesenchymal stem cells and human fibroblast in 2:1:1 ratio respectively were used in a dynamic culture for 6-8 weeks. Contractions at different areas of the tissue were recorded at an average beating rate of 67 beats/min. In addition, positive cardiac markers (Troponin T), Fibroblast (vemintin), and mesenchymal stem cells (CD90) were detected. Not only that, but by week 3, MSC started differentiating to cardiac cells progressively until few CD90 positive cells were very few by week 6 with increasing troponin t positive cells in parallel. Electrophysiological and drug studies were difficult to obtain due to tissue thickness and limited assessment sources. However, the same construct was established using small intestine submucosa (SISer) scaffold, which recorded a spontaneous beating rate between 0.88 and 1.2 Hz, a conduction velocity of 23.9 ± 0.74 cm s-1, and a maximal contraction force of 0.453 ± 0.015 mN. Moreover, electrophysiological studies demonstrated a drug-dependent response on beating rate; a higher adrenalin frequency was revealed in comparison to the untreated tissue and isoproterenol administration, whereas a decrease in beating rate was observed with propranolol and untreated tissue. The present study demonstrated the establishment of vascularized cardiac tissue, which can be used for human clinical application.}, language = {en} } @phdthesis{Albert2019, author = {Albert, Michael}, title = {Intelligent analysis of medical data in a generic telemedicine infrastructure}, isbn = {978-3-945459-26-3 (Online)}, doi = {10.25972/OPUS-17421}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-174213}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Telemedicine uses telecommunication and information technology to provide health care services over spatial distances. In the upcoming demographic changes towards an older average population age, especially rural areas suffer from a decreasing doctor to patient ratio as well as a limited amount of available medical specialists in acceptable distance. These areas could benefit the most from telemedicine applications as they are known to improve access to medical services, medical expertise and can also help to mitigate critical or emergency situations. Although the possibilities of telemedicine applications exist in the entire range of healthcare, current systems focus on one specific disease while using dedicated hardware to connect the patient with the supervising telemedicine center. This thesis describes the development of a telemedical system which follows a new generic design approach. This bridges the gap of existing approaches that only tackle one specific application. The proposed system on the contrary aims at supporting as many diseases and use cases as possible by taking all the stakeholders into account at the same time. To address the usability and acceptance of the system it is designed to use standardized hardware like commercial medical sensors and smartphones for collecting medical data of the patients and transmitting them to the telemedical center. The smartphone can also act as interface to the patient for health questionnaires or feedback. The system can handle the collection and transport of medical data, analysis and visualization of the data as well as providing a real time communication with video and audio between the users. On top of the generic telemedical framework the issue of scalability is addressed by integrating a rule-based analysis tool for the medical data. Rules can be easily created by medical personnel via a visual editor and can be personalized for each patient. The rule-based analysis tool is extended by multiple options for visualization of the data, mechanisms to handle complex rules and options for performing actions like raising alarms or sending automated messages. It is sometimes hard for the medical experts to formulate their knowledge into rules and there may be information in the medical data that is not yet known. This is why a machine learning module was integrated into the system. It uses the incoming medical data of the patients to learn new rules that are then presented to the medical personnel for inspection. This is in line with European legislation where the human still needs to be in charge of such decisions. Overall, we were able to show the benefit of the generic approach by evaluating it in three completely different medical use cases derived from specific application needs: monitoring of COPD (chronic obstructive pulmonary disease) patients, support of patients performing dialysis at home and councils of intensive-care experts. In addition the system was used for a non-medical use case: monitoring and optimization of industrial machines and robots. In all of the mentioned cases, we were able to prove the robustness of the generic approach with real users of the corresponding domain. This is why we can propose this approach for future development of telemedical systems.}, subject = {Telemedizin}, language = {en} } @phdthesis{Alexander2019, author = {Alexander, Stephanie}, title = {Collective cancer cell invasion \(in\) \(vivo\): function of β1 and β3 integrins in perivascular invasion and resistance to therapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85435}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Pro-migratory signals mediated by the tumor microenvironment contribute to the cancer progression cascade, including invasion, metastasis and resistance to therapy. Derived from in vitro studies, isolated molecular steps of cancer invasion programs have been identified but their integration into the tumor microenvironment and suitability as molecular targets remain elusive. The purpose of the study was to visualize central aspects of tumor progression, including proliferation, survival and invasion by real-time intravital microscopy. The specific aims were to monitor the kinetics, mode, adhesion and chemoattraction mechanisms of tumor cell invasion, the involved guidance structures, and the response of invasion zones to anti-cancer therapy. To reach deeper tumor regions by optical imaging with subcellular resolution, near-infrared and infrared excited multiphoton microscopy was combined with a modified dorsal skinfold chamber model. Implanted HT-1080 fibrosarcoma and B16/F10 and MV3 melanoma tumors developed zones of invasive growth consisting of collective invasion strands that retained cell-cell contacts and high mitotic activity while invading at velocities of up to 200 μm per day. Collective invasion occurred predominantly along preexisting tissue structures, including blood and lymph vessels, collagen fibers and muscle strands of the deep dermis, and was thereby insensitive to RNAi based knockdown and/or antibody-based treatment against β1 and β3 integrins, chemokine (SDF-1/CXCL12) and growth factor (EGF) signaling. Therapeutic hypofractionated irradiation induced partial to complete regression of the tumor main mass, yet failed to eradicate the collective invasion strands, suggesting a microenvironmentally privileged niche. Whereas no radiosensitization was achieved by interference with EGFR or doxorubicin, the simultaneous inhibition of β1 and β3 integrins impaired cell proliferation and survival in spontaneously growing tumors and strongly enhanced the radiation response up to complete eradication of both main tumor and invasion strands. In conclusion, collective invasion in vivo is a robust process which follows preexisting tissue structures and is mainly independent of established adhesion and chemoattractant signaling. Due to its altered biological response to irradiation, collective invasion strands represent a microenvironmentally controlled and clinically relevant resistance niche to therapy. Therefore supportive regimens, such as anoikisinduction by anti-integrin therapy, may serve to enhance radio- and chemoefficacy and complement classical treatment regimens.}, subject = {Tumorzelle}, language = {en} } @phdthesis{Anany2019, author = {Anany, Mohamed Ahmed Mohamed Mohamed}, title = {Enhancement of Toll-like receptor3 (TLR3)-induced death signaling by TNF-like weak inducer of apoptosis (TWEAK)}, doi = {10.25972/OPUS-18975}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189757}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a member of the TNF superfamily (TNFSF) and is as such initially expressed as type II class transmembrane glycoprotein from which a soluble ligand form can be released by proteolytic processing. While the expression of TWEAK has been detected at the mRNA level in various cell lines and cell types, its cell surface expression has so far only been documented for dendritic cells, monocytes and interferon-γ stimulated NK cells. The fibroblast growth factor-inducible-14 (Fn14) is a TRAF2-interacting receptor of the TNF receptor superfamily (TNFRSF) and is the only receptor for TWEAK. The expression of Fn14 is strongly induced in a variety of non-hematopoietic cell types after tissue injury. The TWEAK/Fn14 system induces pleiotropic cellular activities such as induction of proinflammatory genes, stimulation of cellular angiogenesis, proliferation, differentiation, migration and in rare cases induction of apoptosis. On the other side, Toll-like receptor3 (TLR3) is one of DNA- and RNA-sensing pattern recognition receptors (PRRs), plays a crucial role in the first line of defense against virus and invading foreign pathogens and cancer cells. Polyinosinic-polycytidylic acid poly(I:C) is a synthetic analog of dsRNA, binds to TLR3 which acts through the adapter TRIF/TICAM1, leading to cytokine secretion, NF-B activation, IRF3 nuclear translocation, inflammatory response and may also elicit the cell death. TWEAK sensitizes cells for TNFR1-induced apoptosis and necroptosis by limiting the availability of protective TRAF2-cIAP1 and TRAF2-cIAP2 complexes, which interact with the TNFR1-binding proteins TRADD and RIPK1. In accordance with the fact that poly(I:C)-induced signaling also involves these proteins, we found enhanced necroptosis-induction in HaCaT and HeLa-RIPK3 by poly(I:C) in the presence of TWEAK (Figure 24). Analysis of a panel of TRADD, FADD, RIPK1 and caspase-8 knockout cells revealed furthermore similarities and differences in the way how these molecules act in cell death signaling by poly(I:C)/TWEAK and TNF and TRAIL. RIPK1 turned out to be essential for poly(I:C)/TWEAK-induced caspase-8-mediated apoptosis but was dispensable for these responses in TNF and TRAIL signaling. Lack of FADD protein abrogated TRAIL- but not TNF- and poly(I:C)-induced necroptosis. Moreover, we observed that both long and short FLIP rescued HaCaT and HeLa-RIPK3 cells from poly(I:C)-induced apoptosis or necroptosis. To sum up, our results demonstrate that TWEAK, which is produced by interferon stimulated myeloid cells, controls the induction of apoptosis and necroptosis by the TLR3 ligand poly(I:C) and may thus contribute to cancer or anti-viral immunity treatment.}, subject = {Immunologe}, language = {en} } @phdthesis{Awad2019, author = {Awad, Eman Da'as}, title = {Modulation of insulin-induced genotoxicity in vitro and genomic damage in gestational diabetes}, doi = {10.25972/OPUS-16186}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161866}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Diabetes mellitus is a global health problem, where the risk of diabetes increases rapidly due to the lifestyle changes. Patients with type II diabetes have many complications with increased risk of morbidity and mortality. High levels of insulin may lead to DNA oxidation and damage. Several studies proposed that hyperinsulinemia may be an important risk factor for various types of cancer. To investigate insulin signaling pathway inducing oxidative stress and genomic damage, pharmaceutical and natural compounds which can interfere with the insulin pathway including PI3K inhibitors, resveratrol, lovastatin, and RAD-001 were selected due to their beneficial effects against metabolic disorder. Thus, the anti-genotoxic potential of these compounds regarding insulin-mediated oxidative stress were investigated in normal rat kidney cells in vitro. Our compounds showed protective effect against genotoxic damage and significantly decreased reactive oxygen specious after treatment of cells with insulin with different mechanisms of protection between the compounds. Thus, these compounds may be attractive candidates for future support of diabetes mellitus therapy. Next, we explored the link between gestational diabetes mellitus and genomic damage in cells derived from human blood. Moreover, we investigated the influence of estradiol, progesterone, adrenaline and triiodothyronine on insulin-induced genomic damage in vitro. First, we studied the effect of these hormones in human promyelocytic leukemia cells and next ex vivo with non-stimulated and stimulated peripheral blood mononuclear cells. In parallel, we also measured the basal genomic damage using three conditions (whole blood, non-stimulated and stimulated peripheral blood mononuclear cells) in a small patient study including non-pregnant controls with/without hormonal contraceptives, with a subgroup of obese women, pregnant women, and gestational diabetes affected women. A second-time point after delivery was also applied for analysis of the blood samples. Our results showed that GDM subjects and obese individuals exhibited higher basal DNA damage compared to lower weight nonpregnant or healthy pregnant women in stimulated peripheral blood mononuclear cells in both comet and micronucleus assays. On the other hand, the DNA damage in GDM women had decreased at two months after birth. Moreover, the applied hormones also showed an influence in vitro in the enhancement of the genomic damage in cells of the control and pregnant groups but this damage did not exceed the damage which existed in obese and gestational diabetes mellitus patients with high level of genomic damage. In conclusion, insulin can induce genomic damage in cultured cells, which can be modulated by pharmaceutical and naturals substances. This may be for future use in the protection of diabetic patients, who suffer from hyperinsulinemia during certain disease stages. A particular form of diabetes, GDM, was shown to lead to elevated DNA damage in affected women, which is reduced again after delivery. Cells of affected women do not show an enhanced, but rather a reduced sensitivity for further DNA damage induction by hormonal treatment in vitro. A potential reason may be an existence of a maximally inducible damage by hormonal influences.}, subject = {Gestationsdiabetes}, language = {en} }