@article{LoefflerLoefflerKobsaretal.2015, author = {Loeffler, Claudia and Loeffler, J{\"u}rgen and Kobsar, Anna and Speer, Christian P. and Eigenthaler, Martin}, title = {Septic Vs Colonizing Group B Streptococci Differentially Regulate Inflammation and Apoptosis in Human Coronary Artery Endothelial Cells - a Pilot Study}, series = {Journal of Pediatrics and Neonatal Care}, volume = {2}, journal = {Journal of Pediatrics and Neonatal Care}, number = {2}, doi = {10.15406/jpnc.2015.02.00064}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125596}, pages = {00064}, year = {2015}, abstract = {In this pilot study, we exemplify differences between a septic and a colonizing GBS strain during their interaction with Endothelial Cells by evaluating cytokine levels, surface and apoptosis-related molecules. These preliminary results indicate that in vitro infection using an exemplary septic GBS strain results in diminished activation of the innate immune response.}, language = {en} } @article{WunschCaspellKuertenetal.2015, author = {Wunsch, Marie and Caspell, Richard and Kuerten, Stefanie and Lehmann, Paul V. and Sundararaman, Srividya}, title = {Serial measurements of apoptotic cell numbers provide better acceptance criterion for PBMC quality than a single measurement prior to the T cell assay}, series = {Cells}, volume = {4}, journal = {Cells}, number = {1}, doi = {10.3390/cells4010040}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150213}, pages = {40-55}, year = {2015}, abstract = {As soon as Peripheral Blood Mononuclear Cells (PBMC) are isolated from whole blood, some cells begin dying. The rate of apoptotic cell death is increased when PBMC are shipped, cryopreserved, or stored under suboptimal conditions. Apoptotic cells secrete cytokines that suppress inflammation while promoting phagocytosis. Increased numbers of apoptotic cells in PBMC may modulate T cell functions in antigen-triggered T cell assays. We assessed the effect of apoptotic bystander cells on a T cell ELISPOT assay by selectively inducing B cell apoptosis using α-CD20 mAbs. The presence of large numbers of apoptotic B cells did not affect T cell functionality. In contrast, when PBMC were stored under unfavorable conditions, leading to damage and apoptosis in the T cells as well as bystander cells, T cell functionality was greatly impaired. We observed that measuring the number of apoptotic cells before plating the PBMC into an ELISPOT assay did not reflect the extent of PBMC injury, but measuring apoptotic cell frequencies at the end of the assay did. Our data suggest that measuring the numbers of apoptotic cells prior to and post T cell assays may provide more stringent PBMC quality acceptance criteria than measurements done only prior to the start of the assay.}, language = {en} } @article{GirschickWolfMorbachetal.2015, author = {Girschick, Hermann and Wolf, Christine and Morbach, Henner and Hertzberg, Christoph and Lee-Kirsch, Min Ae}, title = {Severe immune dysregulation with neurological impairment and minor bone changes in a child with spondyloenchondrodysplasia due to two novel mutations in the ACP5 gene}, series = {Pediatric Rheumatology}, volume = {13}, journal = {Pediatric Rheumatology}, number = {37}, doi = {10.1186/s12969-015-0035-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149990}, year = {2015}, abstract = {Spondyloenchondrodysplasia (SPENCD) is a rare skeletal dysplasia, characterized by metaphyseal lesions, neurological impairment and immune dysregulation associated with lupus-like features. SPENCD is caused by biallelic mutations in the ACP5 gene encoding tartrate-resistant phosphatase. We report on a child, who presented with spasticity, multisystem inflammation, autoimmunity and immunodeficiency with minimal metaphyseal changes due to compound heterozygosity for two novel ACP5 mutations. These findings extend the phenotypic spectrum of SPENCD and indicate that ACP5 mutations can cause severe immune dysregulation and neurological impairment even in the absence of metaphyseal dysplasia.}, language = {en} } @article{ShityakovPuskasPapaietal.2015, author = {Shityakov, Sergey and Pusk{\´a}s, Istv{\´a}n and P{\´a}pai, Katalin and Salvador, Ellaine and Roewer, Norbert and F{\"o}rster, Carola and Broscheit, Jens-Albert}, title = {Sevoflurane-sulfobutylether-\(\beta\)-cyclodextrin complex: preparation, characterization, cellular toxicity, molecular modeling and blood-brain barrier transport studies}, series = {Molecules}, volume = {20}, journal = {Molecules}, doi = {10.3390/molecules200610264}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148543}, pages = {10264-10279}, year = {2015}, abstract = {The objective of the present investigation was to study the ability of sulfobutylether-\(\beta\)-cyclodextrin (SBECD) to form an inclusion complex with sevoflurane (SEV), a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB) permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBE\(\beta\)CD complex was nontoxic to the primary brain microvascular endothelial (pEND) cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol) concerning calculated apparent permeability values (P\(_{app}\)). In addition, SEV binding affinity to SBE\(\beta\)CD was confirmed by a minimal Gibbs free energy of binding (ΔG\(_{bind}\)) value of -1.727 ± 0.042 kcal・mol\(^{-1}\) and an average binding constant (K\(_{b}\)) of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity.}, language = {en} } @article{TuchscherrBischoffLattaretal.2015, author = {Tuchscherr, Lorena and Bischoff, Markus and Lattar, Santiago M. and Noto Llana, Mariangeles and Pf{\"o}rtner, Henrike and Niemann, Silke and Geraci, Jennifer and Van de Vyver, H{\´e}l{\`e}ne and Fraunholz, Martin J. and Cheung, Ambrose L. and Herrmann, Mathias and V{\"o}lker, Uwe and Sordelli, Daniel O. and Peters, Georg and Loeffler, Bettina}, title = {Sigma factor SigB is crucial to mediate Staphylococcus aureus adaptation during chronic infections}, series = {PLoS Pathogens}, volume = {11}, journal = {PLoS Pathogens}, number = {4}, doi = {10.1371/journal.ppat.1004870}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143419}, pages = {e1004870}, year = {2015}, abstract = {Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs), which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, \(\Delta\)sigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy-refractory infections.}, language = {en} } @article{OkoroBarquistConnoretal.2015, author = {Okoro, Chinyere K. and Barquist, Lars and Connor, Thomas R. and Harris, Simon R. and Clare, Simon and Stevens, Mark P. and Arends, Mark J. and Hale, Christine and Kane, Leanne and Pickard, Derek J. and Hill, Jennifer and Harcourt, Katherine and Parkhill, Julian and Dougan, Gordon and Kingsley, Robert A.}, title = {Signatures of adaptation in human invasive Salmonella Typhimurium ST313 populations from sub-Saharan Africa}, series = {PLoS Neglected Tropical Diseases}, volume = {9}, journal = {PLoS Neglected Tropical Diseases}, number = {3}, doi = {10.1371/journal.pntd.0003611}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143779}, pages = {e0003611}, year = {2015}, abstract = {Two lineages of Salmonella enterica serovar Typhimurium (S. Typhimurium) of multi-locus sequence type ST313 have been linked with the emergence of invasive Salmonella disease across sub-Saharan Africa. The expansion of these lineages has a temporal association with the HIV pandemic and antibiotic usage. We analysed the whole genome sequence of 129 ST313 isolates representative of the two lineages and found evidence of lineage-specific genome degradation, with some similarities to that observed in S. Typhi. Individual ST313 S. Typhimurium isolates exhibit a distinct metabolic signature and modified enteropathogenesis in both a murine and cattle model of colitis, compared to S. Typhimurium outside of the ST313 lineages. These data define phenotypes that distinguish ST313 isolates from other S. Typhimurium and may represent adaptation to a distinct pathogenesis and lifestyle linked to an-immuno-compromised human population.}, language = {en} } @article{EdenZieglerGilbertetal.2015, author = {Eden, Lars and Ziegler, Dirk and Gilbert, Fabian and Fehske, Kai and Fenwick, Annabel and Meffert, Rainer H.}, title = {Significant pain reduction and improved functional outcome after surgery for displaced midshaft clavicular fractures}, series = {Journal of Orthopaedic Surgery and Research}, volume = {10}, journal = {Journal of Orthopaedic Surgery and Research}, number = {190}, doi = {10.1186/s13018-015-0336-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146357}, year = {2015}, abstract = {Purpose Displaced midshaft clavicular fractures can be treated conservatively as well as operatively by titan elastic nail (TEN) or plate fixation. This survey was performed to evaluate the clinical results of each treatment method and elaborate advantages or possible complications of each modality. Methods Between 2008 and 2013, 102 patients were prospectively included in our study—37 patients for conservative treatment with a rucksack bandage for 4 to 6 weeks, 41 patients for plate osteosynthesis, and 24 for intramedullary stabilization with TEN. Disabilities of the Arm, Shoulder and Hand (DASH), Constant Murley Score (CMS), and visual analog scale (VAS) for pain and function as well as time of invalidity were recorded over a 1-year period. Results The clinical data collected reveals that all three different therapies lead to good or excellent clinical results after 1 year. However, one can observe advantages of operative treatment in comparison to conservative therapy in some characteristics. Conclusion Our data shows that there are several indications where operative treatment has advantages compared to conservative treatment. In special fracture types (Robinson 2B1), TEN gives the best results. Plate fixation is extraordinarily sufficient in pain reduction within the first 5 weeks and indicated in more-part fractures (Robinson 2B2). Nevertheless, conservative treatment is always a good and promising way to treat clavicular fractures, so that individual indications and thorough patient informative talks are inevitable.}, language = {en} } @article{AlizadehradKruegerEngstleretal.2015, author = {Alizadehrad, Davod and Kr{\"u}ger, Timothy and Engstler, Markus and Stark, Holger}, title = {Simulating the complex cell design of Trypanosoma brucei and its motility}, series = {PLOS Computational Biology}, volume = {11}, journal = {PLOS Computational Biology}, number = {1}, doi = {10.1371/journal.pcbi.1003967}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144610}, pages = {e1003967}, year = {2015}, abstract = {The flagellate Trypanosoma brucei, which causes the sleeping sickness when infecting a mammalian host, goes through an intricate life cycle. It has a rather complex propulsion mechanism and swims in diverse microenvironments. These continuously exert selective pressure, to which the trypanosome adjusts with its architecture and behavior. As a result, the trypanosome assumes a diversity of complex morphotypes during its life cycle. However, although cell biology has detailed form and function of most of them, experimental data on the dynamic behavior and development of most morphotypes is lacking. Here we show that simulation science can predict intermediate cell designs by conducting specific and controlled modifications of an accurate, nature-inspired cell model, which we developed using information from live cell analyses. The cell models account for several important characteristics of the real trypanosomal morphotypes, such as the geometry and elastic properties of the cell body, and their swimming mechanism using an eukaryotic flagellum. We introduce an elastic network model for the cell body, including bending rigidity and simulate swimming in a fluid environment, using the mesoscale simulation technique called multi-particle collision dynamics. The in silico trypanosome of the bloodstream form displays the characteristic in vivo rotational and translational motility pattern that is crucial for survival and virulence in the vertebrate host. Moreover, our model accurately simulates the trypanosome's tumbling and backward motion. We show that the distinctive course of the attached flagellum around the cell body is one important aspect to produce the observed swimming behavior in a viscous fluid, and also required to reach the maximal swimming velocity. Changing details of the flagellar attachment generates less efficient swimmers. We also simulate different morphotypes that occur during the parasite's development in the tsetse fly, and predict a flagellar course we have not been able to measure in experiments so far.}, language = {en} } @article{KurrekMorganHowardetal.2015, author = {Kurrek, Matt M. and Morgan, Pamela and Howard, Steven and Kranke, Peter and Calhoun, Aaron and Hui, Joshua and Kiss, Alex}, title = {Simulation as a New Tool to Establish Benchmark Outcome Measures in Obstetrics}, series = {PLoS ONE}, volume = {10}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0131064}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151646}, pages = {e0131064}, year = {2015}, abstract = {Background There are not enough clinical data from rare critical events to calculate statistics to decide if the management of actual events might be below what could reasonably be expected (i.e. was an outlier). Objectives In this project we used simulation to describe the distribution of management times as an approach to decide if the management of a simulated obstetrical crisis scenario could be considered an outlier. Design Twelve obstetrical teams managed 4 scenarios that were previously developed. Relevant outcome variables were defined by expert consensus. The distribution of the response times from the teams who performed the respective intervention was graphically displayed and median and quartiles calculated using rank order statistics. Results Only 7 of the 12 teams performed chest compressions during the arrest following the 'cannot intubate/cannot ventilate' scenario. All other outcome measures were performed by at least 11 of the 12 teams. Calculation of medians and quartiles with 95\% CI was possible for all outcomes. Confidence intervals, given the small sample size, were large. Conclusion We demonstrated the use of simulation to calculate quantiles for management times of critical event. This approach could assist in deciding if a given performance could be considered normal and also point to aspects of care that seem to pose particular challenges as evidenced by a large number of teams not performing the expected maneuver. However sufficiently large sample sizes (i.e. from a national data base) will be required to calculate acceptable confidence intervals and to establish actual tolerance limits.}, language = {en} } @phdthesis{Kurrek2015, author = {Kurrek, Matthias M.}, title = {Simulation To Establish Benchmark Outcome Measures}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143882}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {Following the early experiences in aviation, medical simulation has rapidly evolved into one of the most novel educational tools of the last three decades. In addition to its use in training individuals or teams in crisis resource management, simulation has been studied as a tool to evaluate technical and non-technical skills of individuals as well as, more recently, entire medical teams. It is usually fairly difficult to obtain clinical reference data from critical events to refute claims that the management of actual events fell below what could reasonably be expected and we demonstrated the use of rank order statistics to calculate quantiles with confidence limits for management times of critical obstetrical events using data from realistic simulation. This approach could be used to describe the distribution of treatment times in order to assist in deciding what performance may constitute an outlier. It can also identify particular challenges of clinical practice and allow the development of educational curricula. While the information derived from simulation has to be interpreted with a high degree of caution for a clinical context, it may represent a further 'added value' or important step in establishing simulation as a training tool and to provide information that could be used in an appropriate clinical context for adverse events. Large amounts of data (such as from a simulation registry) would allow the calculation of acceptable confidence intervals for the required outcome parameters as well as actual tolerance limits.}, language = {en} } @article{KugerFlentjeDjuzenova2015, author = {Kuger, Sebastian and Flentje, Michael and Djuzenova, Cholpon S.}, title = {Simultaneous perturbation of the MAPK and the PI3K/mTOR pathways does not lead to increased radiosensitization}, series = {Radiation Oncology}, volume = {10}, journal = {Radiation Oncology}, number = {214}, doi = {10.1186/s13014-015-0514-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126104}, year = {2015}, abstract = {Background The mitogen-activated protein kinases (MAPK) and the phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathways are intertwined on various levels and simultaneous inhibition reduces tumorsize and prolonges survival synergistically. Furthermore, inhibiting these pathways radiosensitized cancer cells in various studies. To assess, if phenotypic changes after perturbations of this signaling network depend on the genetic background, we integrated a time series of the signaling data with phenotypic data after simultaneous MAPK/ERK kinase (MEK) and PI3K/mTOR inhibition and ionizing radiation (IR). Methods The MEK inhibitor AZD6244 and the dual PI3K/mTOR inhibitor NVP-BEZ235 were tested in glioblastoma and lung carcinoma cells, which differ in their mutational status in the MAPK and the PI3K/mTOR pathways. Effects of AZD6244 and NVP-BEZ235 on the proliferation were assessed using an ATP assay. Drug treatment and IR effects on the signaling network were analyzed in a time-dependent manner along with measurements of phenotypic changes in the colony forming ability, apoptosis, autophagy or cell cycle. Results Both inhibitors reduced the tumor cell proliferation in a dose-dependent manner, with NVP-BEZ235 revealing the higher anti-proliferative potential. Our Western blot data indicated that AZD6244 and NVP-BEZ235 perturbed the MAPK and PI3K/mTOR signaling cascades, respectively. Additionally, we confirmed crosstalks and feedback loops in the pathways. As shown by colony forming assay, the AZD6244 moderately radiosensitized cancer cells, whereas NVP-BEZ235 caused a stronger radiosensitization. Combining both drugs did not enhance the NVP-BEZ235-mediated radiosensitization. Both inhibitors caused a cell cycle arrest in the G1-phase, whereas concomitant IR and treatment with the inhibitors resulted in cell line- and drug-specific cell cycle alterations. Furthermore, combining both inhibitors synergistically enhanced a G1-phase arrest in sham-irradiated glioblastoma cells and induced apoptosis and autophagy in both cell lines. Conclusion Perturbations of the MEK and the PI3K pathway radiosensitized tumor cells of different origins and the combination of AZD6244 and NVP-BEZ235 yielded cytostatic effects in several tumor entities. However, this is the first study assessing, if the combination of both drugs also results in synergistic effects in terms of radiosensitivity. Our study demonstrates that simultaneous treatment with both pathway inhibitors does not lead to synergistic radiosensitization but causes cell line-specific effects.}, language = {en} } @article{HeStolteBurschkaetal.2015, author = {He, Tao and Stolte, Matthias and Burschka, Christian and Hansen, Nis Hauke and Musiol, Thomas and K{\"a}lblein, Daniel and Pflaum, Jens and Tao, Xutang and Brill, Jochen and W{\"u}rthner, Frank}, title = {Single-crystal field-effect transistors of new Cl\(_{2}\)-NDI polymorph processed by sublimation in air}, series = {Nature Communications}, volume = {6}, journal = {Nature Communications}, number = {5954}, doi = {10.1038/ncomms6954}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149255}, year = {2015}, abstract = {Physical properties of active materials built up from small molecules are dictated by their molecular packing in the solid state. Here we demonstrate for the first time the growth of n-channel single-crystal field-effect transistors and organic thin-film transistors by sublimation of 2,6-dichloro-naphthalene diimide in air. Under these conditions, a new polymorph with two-dimensional brick-wall packing mode (\(\beta\)-phase) is obtained that is distinguished from the previously reported herringbone packing motif obtained from solution (\(\alpha\)-phase). We are able to fabricate single-crystal field-effect transistors with electron mobilities in air of up to 8.6 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\) (\(\alpha\)-phase) and up to 3.5 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\) (\(\beta\)-phase) on n-octadecyltriethoxysilane-modified substrates. On silicon dioxide, thin-film devices based on \(\beta\)-phase can be manufactured in air giving rise to electron mobilities of 0.37 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\). The simple crystal and thin-film growth procedures by sublimation under ambient conditions avoid elaborate substrate modifications and costly vacuum equipment-based fabrication steps.}, language = {en} } @article{BoelchJansenMeffertetal.2015, author = {Boelch, S. P. and Jansen, H. and Meffert, R. H. and Frey, S. P.}, title = {Six Sesamoid Bones on Both Feet: Report of a Rare Case}, series = {Journal of Clinical and Diagnostic Research}, volume = {9}, journal = {Journal of Clinical and Diagnostic Research}, number = {8}, doi = {10.7860/JCDR/2015/12842.6394}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126073}, pages = {RD04-RD05}, year = {2015}, abstract = {There is a variation of the total number of distinct bones in the human in the literature. This difference is mainly caused by the variable existence of sesamoid bones. Sesamoid bones at the first MTP are seen regularly. In contrast additional sesamoid bones at the divond to fifth MTP are rare. We report a case of additional sesamoid bones at every metatarsophalangeal joint (MTP) of both feet. A 22-year-old female Caucasian presented with weight-dependent pain of the divond MTP of the left foot. In the radiographs of both feet additional sesamoid bones at every MTP could be seen. This case reports a very rare variation in human anatomy. A similar case has not been displayed to the academic society and therefore should be acknowledged.}, language = {en} } @article{MergetSotriffer2015, author = {Merget, Benjamin and Sotriffer, Christoph A.}, title = {Slow-Onset Inhibition of Mycobacterium tuberculosis InhA: Revealing Molecular Determinants of Residence Time by MD Simulations}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {5}, doi = {10.1371/journal.pone.0127009}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125607}, pages = {e0127009}, year = {2015}, abstract = {An important kinetic parameter for drug efficacy is the residence time of a compound at a drug target, which is related to the dissociation rate constant koff. For the essential antimycobacterial target InhA, this parameter is most likely governed by the ordering of the flexible substrate binding loop (SBL). Whereas the diphenyl ether inhibitors 6PP and triclosan (TCL) do not show loop ordering and thus, no slow-binding inhibition and high koff values, the slightly modified PT70 leads to an ordered loop and a residence time of 24 minutes. To assess the structural differences of the complexes from a dynamic point of view, molecular dynamics (MD) simulations with a total sampling time of 3.0 µs were performed for three ligand-bound and two ligand-free (perturbed) InhA systems. The individual simulations show comparable conformational features with respect to both the binding pocket and the SBL, allowing to define five recurring conformational families. Based on their different occurrence frequencies in the simulated systems, the conformational preferences could be linked to structural differences of the respective ligands to reveal important determinants of residence time. The most abundant conformation besides the stable EI* state is characterized by a shift of Ile202 and Val203 toward the hydrophobic pocket of InhA. The analyses revealed potential directions for avoiding this conformational change and, thus, hindering rapid dissociation: (1) an anchor group in 2'-position of the B-ring for scaffold stabilization, (2) proper occupation of the hydrophobic pocket, and (3) the introduction of a barricade substituent in 5'-position of the diphenyl ether B-ring.}, language = {en} } @article{HerterStauchGallantetal.2015, author = {Herter, Eva K. and Stauch, Maria and Gallant, Maria and Wolf, Elmar and Raabe, Thomas and Gallant, Peter}, title = {snoRNAs are a novel class of biologically relevant Myc targets}, series = {BMC Biology}, volume = {13}, journal = {BMC Biology}, number = {25}, doi = {10.1186/s12915-015-0132-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124956}, year = {2015}, abstract = {Background Myc proteins are essential regulators of animal growth during normal development, and their deregulation is one of the main driving factors of human malignancies. They function as transcription factors that (in vertebrates) control many growth- and proliferation-associated genes, and in some contexts contribute to global gene regulation. Results We combine chromatin immunoprecipitation-sequencing (ChIPseq) and RNAseq approaches in Drosophila tissue culture cells to identify a core set of less than 500 Myc target genes, whose salient function resides in the control of ribosome biogenesis. Among these genes we find the non-coding snoRNA genes as a large novel class of Myc targets. All assayed snoRNAs are affected by Myc, and many of them are subject to direct transcriptional activation by Myc, both in Drosophila and in vertebrates. The loss of snoRNAs impairs growth during normal development, whereas their overexpression increases tumor mass in a model for neuronal tumors. Conclusions This work shows that Myc acts as a master regulator of snoRNP biogenesis. In addition, in combination with recent observations of snoRNA involvement in human cancer, it raises the possibility that Myc's transforming effects are partially mediated by this class of non-coding transcripts.}, language = {en} } @phdthesis{Meyer2015, author = {Meyer, Frank}, title = {Soft X-ray Spectroscopic Study of Amino Acid and Salt Solutions}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124295}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {This thesis focuses on the investigation of the electronic structure of amino acids and salts in aqueous solution using X-ray spectroscopic methods. Both material groups are of fundamental importance with regards to many physiological reactions, especially for the Hofmeister effect which describes the solubility of proteins in salt solutions. Hence, the investigation of the electronic structure of amino acids and the influence of ions on the hydrogen bonding network of liquid water are important milestones to a deeper understanding of the Hofmeister series. Besides investigating the electronic structure of amino acids in aqueous solution, the spectra were used to develop a building block model of the spectral fingerprints of the functional groups and were compared to spectral signatures of suitable reference molecules. In the framework of this thesis, it is shown that the building block approach is a useful tool with allows the interpretation of spectral signatures of considerably more complex molecules In this work, the focus lies on the investigation of the occupied and unoccupied electronic states of molecules in solid state, as well as in aqueous solution. Hereby, different X-ray spectroscopic methods were applied. X-ray emission spectroscopy (XES) was used to probe the occupied electronic structure of the solution, while the unoccupied electronic structure was addressed by using X-ray absorption spectroscopy (XAS). Finally, resonant inelastic X-ray scattering (RIXS) as a combination of XAS and XES measurements provides the combined information about the unoccupied and occupied molecular levels. The element specific character of the three measurement methods is a feature which allows the investigation of the local electronic structure of a single functional group. With RIXS, also non-equivalent atoms of the same element can be addressed separately. Within this thesis firstly, a library of the XE spectra of all 20 proteinogenic amino acids in zwitterionic form is presented. From this sample-set XES fingerprints of the protonated alpha-amino group NH3+ and the deprotonated carboxylic group COO- were evaluated and used to identify the XES fingerprints of the nitrogen and oxygen containing functional groups of the side chains of the amino acids. The data is discussed based on a building block approach. Furthermore, the XE spectra of the functional groups of lysine and histidine, namely the NH2 group and the C3N2H4 ring structure, are both compared to XE spectra of suitable reference molecules (imidazole, ammonia and methylamine). It is found that the XE and RIXS spectra of the side chains of lysine and histidine show large similarities to the XE spectra of the reference molecules. This agreement in the XE and RIXS spectra allows a qualitative investigation of XE and RIXS spectra of more complex amino acids using the XE and RIXS spectra of suitable reference molecules. The chemical structure of histidine and proline is quite different from the structures of the other proteinogenic amino acids. Due to the unique chemical structure of the side chain which in both cases consists of a heterocyclic ring structure, these two amino acids were investigated in more detail. Zubavichus et al. [1] have shown that amino acids are decomposing while exposed to X-ray radiation of the experiment. The damage is irreversible and molecular fragments can adsorb on the membrane of the experimental setup. This contamination can also create a spectral signature which then overlaps with the signal of the solution and which complicates the interpretation of the data. To record spectra which are free from contributions of adsorbed molecular fragments on the membrane, the adsorption behavior was investigated. In contrast to the solid phase in which the amino acids are present as salts in one electronic conformation, the charge state of the amino acids can be manipulated in aqueous solution by tuning the pH-value. By doing this, all possible charge states are accessible (cation, anion, zwitterion). In this work it is shown that also the spectra of the different charge states can be modeled by the spectra of suitable reference molecules using the building block approach. The spectral changes occurring upon protonation and deprotonation of the functional groups are explored and verified by comparing them to theoretical calculations. The comparison with measurements of pyrrolidine show that the electronic structure which surrounds the nitrogen atom of proline is strongly influenced by the ring structure of the side chain. Furthermore, the proline, pyrrolidine, and histidine molecules are also degrading during the liquid sample measurements. This can be observed by the detection of a new spectral component which increases with the measurement time originating from the window membrane. In all cases, the speed of the agglomeration of molecular fragments at the membrane was observed to be highly sensitive to the pH value of the solution. To understand the Hofmeister series, also the impact of the salt ions have to be investigated. In this study the influence of potassium chloride (KCl) on the hydrogen bond network of water was studied by using non-resonantly excited XES as well as RIXS. A decreased dissociation of hydrogen molecules and changes in the molecular vibrations could be detected. These changes were interpreted with a molecular reorganization of the water molecules and a decreased number of hydrogen bonds.}, subject = {Aminos{\"a}uren}, language = {en} } @phdthesis{Bruttel2015, author = {Bruttel, Valentin Stefan}, title = {Soluble HLA-G binds to dendritic cells which likely suppresses anti-tumour immune responses in regional lymph nodes in ovarian carcinoma}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127252}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {Zusammenfassung Einleitung HLA-G, ein nicht-klassisches HLA bzw. MHC Klasse Ib Molek{\"u}l, kann sowohl als membrangebundenes als auch als l{\"o}sliches Molek{\"u}l verschiedenste Immunzellpopulationen effektiv inhibieren. Unter physiologischen Bedingungen wird HLA-G vor allem in der Plazenta exprimiert, wo es dazu beitr{\"a}gt den semiallogenen Embryo vor einer Abstoßung durch das m{\"u}tterliche Immunsystem zu besch{\"u}tzen. Außerdem wird HLA-G in einer Vielzahl von Tumoren wie zum Beispiel in Ovarialkarzinomen {\"u}berexprimiert. Ziel dieser Arbeit war es besonders die Rolle von l{\"o}slichem HLA-G im Ovarialkarzinom und die Expression von HLA-G in verschiedenen Subtypen des Ovarialkarzinoms genauer zu untersuchen. Ergebnisse Anhand eines Tissue Microarrays wurde best{\"a}tigt dass HLA-G unter physiologischen Bedingungen nur in sehr wenigen Geweben wie Plazenta oder Testes exprimiert wird. Außerdem wurden erstmals auch im Nebennierenmark hohe Expressionslevel detektiert. Im Gegensatz zur physiologischen Expression wurde HLA-G in ser{\"o}sen, muzin{\"o}sen, endometrioiden und Klarzellkarzinomen und somit in Tumoren aller untersuchten Subtypen des Ovarialkarzinoms detektiert. Am h{\"a}ufigsten war HLA-G in hochgradigen ser{\"o}sen Karzinomen {\"u}berexprimiert. Hier konnte gezeigt werden dass auf Genexpressionslevel in Ovarialkarzinomen die Expression des immunsuppressiven HLA-G mit der Expression von klassischen MHC Molek{\"u}len wie HLA-A, -B oder -C hochsignifikant korreliert. Außerdem konnte in Aszitesproben von Patientinnen mit Ovarialkarzinomen hohe Konzentrationen von l{\"o}slichem HLA-G nachgewiesen werden. Auch auf metastasierten Tumorzellen in regionalen Lymphknoten war HLA-G nachweisbar. {\"U}berraschenderweise wurde aber besonders viel HLA-G auf Dendritischen Zellen in Lymphknoten detektiert. Da in Monozyten und Dendritischen Zellen von gesunden Spendern durch IL-4 oder IL-10 im Gegensatz zu Literatur keine Expression von HLA-G induzierbar war, untersuchten wir ob Dendritische Zellen l{\"o}sliches HLA-G binden. Es konnte gezeigt werden, dass besonders Dendritische Zellen die in Gegenwart von IL-4, IL-10 und GM-CSF aus Monozyten generiert wurden (DC-10) effektiv l{\"o}sliches HLA-G {\"u}ber ILT Rezeptoren binden. In Abh{\"a}ngigkeit von ihrer Beladung mit HLA-G hemmen auch fixierte DC-10 Zellen noch die Proliferation von zytotoxischen CD8+ T Zellen. Zudem wurden regulatorische T Zellen induziert. Schlussfolgerungen Besonders in den am h{\"a}ufigsten diagnostizierten hochgradigen ser{\"o}sen Ovarialkarzinomen ist HLA-G in den meisten F{\"a}llen {\"u}berexprimiert. Durch die Expression immunsuppressiver MHC Klasse Ib Molek{\"u}le wie HLA-G k{\"o}nnen wahrscheinlich auch Tumore wachsen, die noch klassische MHC Molek{\"u}le exprimieren und aufgrund ihrer Mutationslast eigentlich vom Immunsystem erkannt und eliminiert werden m{\"u}ssten. L{\"o}sliches HLA-G k{\"o}nnte zudem lokal Immunantworten gegen Tumorantigene unterdr{\"u}cken indem es an Dendritische Zellen in regionalen Lymphknoten bindet. Diese Zellen pr{\"a}sentieren nomalerweise zytotoxischen T Zellen Tumorantigene und spielen daher eine entscheidende Rolle in der Entstehung von protektiven Immunantworten. Mit l{\"o}slichem HLA-G beladene Dendritische Zellen hemmen jedoch die Proliferation von CD8+ T Zellen und induzieren regulatorische T Zellen. Dadurch k{\"o}nnten Ovarialkarzinome "aus der Ferne" auch in metastasenfreien Lymphknoten die Entstehung von gegen den Tumor gerichteten Immunantworten unterdr{\"u}cken. Dieser erstmals beschriebene Mechanismus k{\"o}nnte auch in anderen malignen Erkrankungen eine Rolle spielen, da l{\"o}sliches HLA-G in einer Vielzahl von Tumorindikationen nachgewiesen wurde.}, subject = {HLA-G}, language = {en} } @article{SchneiderKleinMielichSuessetal.2015, author = {Schneider, Johannes and Klein, Teresa and Mielich-S{\"u}ss, Benjamin and Koch, Gudrun and Franke, Christian and Kuipers, Oskar P. and Kov{\´a}cs, {\´A}kos T. and Sauer, Markus and Lopez, Daniel}, title = {Spatio-temporal Remodeling of Functional Membrane Microdomains Organizes the Signaling Networks of a Bacterium}, series = {PLoS Genetics}, volume = {11}, journal = {PLoS Genetics}, number = {4}, doi = {10.1371/journal.pgen.1005140}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125577}, pages = {e1005140}, year = {2015}, abstract = {Lipid rafts are membrane microdomains specialized in the regulation of numerous cellular processes related to membrane organization, as diverse as signal transduction, protein sorting, membrane trafficking or pathogen invasion. It has been proposed that this functional diversity would require a heterogeneous population of raft domains with varying compositions. However, a mechanism for such diversification is not known. We recently discovered that bacterial membranes organize their signal transduction pathways in functional membrane microdomains (FMMs) that are structurally and functionally similar to the eukaryotic lipid rafts. In this report, we took advantage of the tractability of the prokaryotic model Bacillus subtilis to provide evidence for the coexistence of two distinct families of FMMs in bacterial membranes, displaying a distinctive distribution of proteins specialized in different biological processes. One family of microdomains harbors the scaffolding flotillin protein FloA that selectively tethers proteins specialized in regulating cell envelope turnover and primary metabolism. A second population of microdomains containing the two scaffolding flotillins, FloA and FloT, arises exclusively at later stages of cell growth and specializes in adaptation of cells to stationary phase. Importantly, the diversification of membrane microdomains does not occur arbitrarily. We discovered that bacterial cells control the spatio-temporal remodeling of microdomains by restricting the activation of FloT expression to stationary phase. This regulation ensures a sequential assembly of functionally specialized membrane microdomains to strategically organize signaling networks at the right time during the lifespan of a bacterium.}, language = {en} } @article{PalettaFichtnerStaricketal.2015, author = {Paletta, Daniel and Fichtner, Alina Suzann and Starick, Lisa and Porcelli, Steven A. and Savage, Paul B. and Herrmann, Thomas}, title = {Species Specific Differences of CD1d Oligomer Loading In Vitro}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {11}, doi = {10.1371/journal.pone.0143449}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124879}, pages = {e0143449}, year = {2015}, abstract = {CD1d molecules are MHC class I-like molecules that present glycolipids to iNKT cells. The highly conserved interaction between CD1d:α-Galactosylceramide (αGC) complexes and the iNKT TCR not only defines this population of αβ T cells but can also be used for its direct identification. Therefore, CD1d oligomers are a widely used tool for iNKT cell related investigations. To this end, the lipid chains of the antigen have to be inserted into the hydrophobic pockets of the CD1d binding cleft, often with help of surfactants. In this study, we investigated the influence of different surfactants (Triton X-100, Tween 20, Tyloxapol) on in vitro loading of CD1d molecules derived from four different species (human, mouse, rat and cotton rat) with αGC and derivatives carrying modifications of the acyl-chain (DB01-1, PBS44) and a 6-acetamido-6-deoxy-addition at the galactosyl head group (PBS57). We also compared rat CD1d dimers with tetramers and staining of an iNKT TCR transductant was used as readout for loading efficacy. The results underlined the importance of CD1d loading efficacy for proper analysis of iNKT TCR binding and demonstrated the necessity to adjust loading conditions for each oligomer/glycolipid combination. The efficient usage of surfactants as a tool for CD1d loading was revealed to be species-specific and depending on the origin of the CD1d producing cells. Additional variation of surfactant-dependent loading efficacy between tested glycolipids was influenced by the acyl-chain length and the modification of the galactosyl head group with PBS57 showing the least dependence on surfactants and the lowest degree of species-dependent differences.}, language = {en} } @phdthesis{Rehm2015, author = {Rehm, Stefanie}, title = {Spermine-functionalized Perylene Bisimide Dyes: Synthesis and Self-assembly in Water}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123201}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {The main objective of this thesis was the design and synthesis of perylene bisimide dyes with sufficient water-solubility for the construction of self-assembled architectures in aqueous solutions. Beside these tasks another goal of this project was the control over the self-assembly process in terms of aggregate size and helicity, respectively. Within this thesis an appropriate synthesis for spermine-functionalized perylene bisimide dyes was developed and conducted successfully. The characterization of these building blocks and their course of self-assembly were investigated by NMR, UV/Vis and fluorescence spectroscopy as well as by atomic force and transmission electron microscopy. For the better understanding of the experimental results theoretical calculations were performed.}, subject = {Perylenderivate}, language = {en} }