Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-19668 Wissenschaftlicher Artikel Ono, Mitsuaki; Sonoyama, Wataru; Nema, Kazuki; Hara, Emilio Satoshi; Oida, Yasutaka; Pham, Hai Thanh; Yamamoto, Katushi; Hirota, Kazuo; Sugama, Kazushige; Sebald, Walter; Kuboki, Takuo Regeneration of calvarial defects with Escherichia coli-derived rhBMP-2 adsorbed in PLGA membrane Objective: Escherichia coli-derived recombinant human bone morphogenetic protein-2 (E-BMP-2) has been shown to be as effective as mammalian cell-derived BMP-2. However, several in vitro and in vivo experiments are still necessary to validate the effectiveness of E-BMP-2 due to the difference in synthesis process, mainly related to protein nonglycosylation. The objective of this study was to investigate whether biodegradable polylactide-co-glycolide (PLGA) membrane is a suitable carrier for E-BMP-2 delivery for bone regeneration of critical-sized defects in rat calvaria. Materials and Methods: First, the osteoinductive effect of E-BMP-2 was confirmed in vitro in mouse bone marrow stromal cells by analysis of osteocalcin mRNA levels, and calcium deposition was detected by alizarin red staining. Before in vivo experiments, the release profile of E-BMP-2 from PLGA membranes was determined by ELISA. E-BMP-2 (0, 1, 5 and 10 μg/μl) was applied for ectopic and orthotopic bone formation and was analyzed by X-ray, micro-CT and histology. Results: Release-profile testing showed that PLGA membrane could retain 94% of the initially applied E-BMP-2. Ectopic bone formation assay revealed that combination of E-BMP-2/PLGA membrane strongly induced bone formation. Stronger osteoinductivity with complete repair of critical-sized defects was observed only with PLGA membranes adsorbed with 5 and 10 μg/μl of E-BMP-2, whereas no bone formation was observed in the groups that received no membrane or 0-μg/μl dose of E-BMP-2. Conclusion: PLGA membrane was shown to be a suitable carrier for sustained release of E-BMP-2, and the E-BMP-2/PLGA membrane combination was demonstrated to be efficient in bone regeneration in a model of critical-sized defects. 2014 9 Cells Tissues Organs 198 5 367 376 urn:nbn:de:bvb:20-opus-196680 10.1159/000356947 Theodor-Boveri-Institut für Biowissenschaften OPUS4-12162 Wissenschaftlicher Artikel Chen, Yi-chun; Gerber, Bertram Generalization and discrimination tasks yield concordant measures of perceived distance between odours and their binary mixtures in larval Drosophila Similarity between odours is notoriously difficult to measure. Widely used behavioural approaches in insect olfaction research are cross-adaptation, masking, as well as associative tasks based on olfactory learning and the subsequent testing for how specific the established memory is. A concern with such memory-based approaches is that the learning process required to establish an odour memory may alter the way the odour is processed, such that measures of perception taken at the test are distorted. The present study was therefore designed to see whether behavioural judgements of perceptual distance are different for two different memory-based tasks, namely generalization and discrimination. We used odour-reward learning in larval Drosophila as a study case. In order to challenge the larvae's olfactory system, we chose to work with binary mixtures and their elements (1-octanol, n-amyl acetate, 3-octanol, benzaldehyde and hexyl acetate). We determined the perceptual distance between each mixture and its elements, first in a generalization task, and then in a discrimination task. It turns out that scores of perceptual distance are correlated between both tasks. A re-analysis of published studies looking at element-to-element perceptual distances in larval reward learning and in adult punishment learning confirms this result. We therefore suggest that across a given set of olfactory stimuli, associative training does not grossly alter the pattern of perceptual distances. 2014 2071-7 The Journal of Experimental Biology 217 12 urn:nbn:de:bvb:20-opus-121625 10.1242/jeb.100966 Theodor-Boveri-Institut für Biowissenschaften OPUS4-11116 Wissenschaftlicher Artikel Wiegering, Armin; Korb, Doreen; Thalheimer, Andreas; Kämmerer, Ulrike; Allmanritter, Jan; Matthes, Niels; Linnebacher, Michael; Schlegel, Nicolas; Klein, Ingo; Ergün, Süleyman; Germer, Christoph-Thomas; Otto, Christoph E7080 (Lenvatinib), a Multi-Targeted Tyrosine Kinase Inhibitor, Demonstrates Antitumor Activities Against Colorectal Cancer Xenografts Clinical prognosis of metastasized colorectal carcinoma (CRC) is still not at desired levels and novel drugs are needed. Here, we focused on the multi-tyrosine kinase inhibitor E7080 (Lenvatinib) and assessed its therapeutic efficacy against human CRC cell lines in vitro and human CRC xenografts in vivo. The effect of E7080 on cell viability was examined on 10 humanCRCcell lines and humanendothelial cells (HUVEC). The inhibitory effect of E7080 on VEGF-induced angiogenesis was studied in an ex vivo mouse aortic ring angiogenesis assay. In addition, the efficacy of E7080 against xenografts derived fromCRC cell lines and CRC patient resection specimenswithmutated KRASwas investigated in vivo. Arelatively low cytotoxic effect of E7080 on CRC cell viabilitywas observed in vitro. Endothelial cells (HUVEC)weremore susceptible to the incubation with E7080. This is in line with the observation that E7080 demonstrated an anti-angiogenic effect in a three-dimensional ex vivo mouse aortic ring angiogenesis assay. E7080 effectively disrupted CRC cell-mediated VEGF-stimulated growth of HUVEC in vitro. Daily in vivo treatment with E7080 (5 mg/kg) significantly delayed the growth of KRAS mutated CRC xenografts with decreased density of tumor-associated vessel formations and without tumor regression. This observation is in line with results that E7080 did not significantly reduce the number of Ki67-positive cells in CRC xenografts. The results suggest antiangiogenic activity of E7080 at a dosage thatwas well tolerated by nudemice. E7080 may provide therapeutic benefits in the treatment of CRC with mutated KRAS. 2014 urn:nbn:de:bvb:20-opus-111165 10.1016/j.neo.2014.09.008 Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) OPUS4-11141 Wissenschaftlicher Artikel Floren, Andreas; Mupepele, Anne-Christine; Müller, Tobias; Dittrich, Marcus Are Temperate Canopy Spiders Tree-Species Specific? Arboreal spiders in deciduous and coniferous trees were investigated on their distribution and diversity. Insecticidal knock-down was used to comprehensively sample spiders from 175 trees from 2001 to 2003 in the Białowieża forest and three remote forests in Poland. We identified 140 species from 9273 adult spiders. Spider communities were distinguished between deciduous and coniferous trees. The richest fauna was collected from Quercus where beta diversity was also highest. A tree-species-specific pattern was clearly observed for Alnus, Carpinus, Picea and Pinus trees and also for those tree species that were fogged in only four or three replicates, namely Betula and Populus. This hitherto unrecognised association was mainly due to the community composition of common species identified in a Dufrene-Legendre indicator species analysis. It was not caused by spatial or temporal autocorrelation. Explaining tree-species specificity for generalist predators like spiders is difficult and has to involve physical and ecological tree parameters like linkage with the abundance of prey species. However, neither did we find a consistent correlation of prey group abundances with spiders nor could differences in spider guild composition explain the observed pattern. Our results hint towards the importance of deterministic mechanisms structuring communities of generalist canopy spiders although the casual relationship is not yet understood. 2014 urn:nbn:de:bvb:20-opus-111413 10.1371/journal.pone.0086571 Theodor-Boveri-Institut für Biowissenschaften OPUS4-12064 Wissenschaftlicher Artikel Haydn, Johannes M.; Hufnagel, Anita; Grimm, Johannes; Maurus, Katja; Schartl, Manfred; Meierjohann, Svenja The MAPK pathway as an apoptosis enhancer in melanoma Inhibition of RAF/MEK/ERK signaling is beneficial for many patients with BRAFV600E-mutated melanoma. However, primary and secondary resistances restrict long-lasting therapy success. Combination therapies are therefore urgently needed. Here, we evaluate the cellular effect of combining a MEK inhibitor with a genotoxic apoptosis inducer. Strikingly, we observed that an activated MAPK pathway promotes in several melanoma cell lines the pro-apoptotic response to genotoxic stress, and MEK inhibition reduces intrinsic apoptosis. This goes along with MEK inhibitor induced increased RAS and P-AKT levels. The protective effect of the MEK inhibitor depends on PI3K signaling, which prevents the induction of pro-apoptotic PUMA that mediates apoptosis after DNA damage. We could show that the MEK inhibitor dependent feedback loop is enabled by several factors, including EGF receptor and members of the SPRED family. The simultaneous knockdown of SPRED1 and SPRED2 mimicked the effects of MEK inhibitor such as PUMA repression and protection from apoptosis. Our data demonstrate that MEK inhibition of BRAFV600E-positive melanoma cells can protect from genotoxic stress, thereby achieving the opposite of the intended anti-tumorigenic effect of the combination of MEK inhibitor with inducers of intrinsic apoptosis. 2014 5040-53 Oncotarget 5 13 urn:nbn:de:bvb:20-opus-120649 Theodor-Boveri-Institut für Biowissenschaften OPUS4-12068 Wissenschaftlicher Artikel Dandekar, Thomas; Fieselmann, Astrid; Fischer, Eva; Popp, Jasmin; Hensel, Michael; Noster, Janina Salmonella—how a metabolic generalist adopts an intracellular lifestyle during infection The human-pathogenic bacterium Salmonella enterica adjusts and adapts to different environments while attempting colonization. In the course of infection nutrient availabilities change drastically. New techniques, "-omics" data and subsequent integration by systems biology improve our understanding of these changes. We review changes in metabolism focusing on amino acid and carbohydrate metabolism. Furthermore, the adaptation process is associated with the activation of genes of the Salmonella pathogenicity islands (SPIs). Anti-infective strategies have to take these insights into account and include metabolic and other strategies. Salmonella infections will remain a challenge for infection biology. 2014 Frontiers in Cellular and Infection Microbiology 4 191 urn:nbn:de:bvb:20-opus-120686 10.3389/fcimb.2014.00191 Theodor-Boveri-Institut für Biowissenschaften OPUS4-12079 Wissenschaftlicher Artikel Klatt, Björn K.; Holzschuh, Andrea; Westphal, Catrin; Clough, Yann; Smit, Inga; Pawelzik, Elke; Tscharntke, Teja Bee pollination improves crop quality, shelf life and commercial value Pollination improves the yield of most crop species and contributes to one-third of global crop production, but comprehensive benefits including crop quality are still unknown. Hence, pollination is underestimated by international policies, which is particularly alarming in times of agricultural intensification and diminishing pollination services. In this study, exclusion experiments with strawberries showed bee pollination to improve fruit quality, quantity and market value compared with wind and self-pollination. Bee-pollinated fruits were heavier, had less malformations and reached higher commercial grades. They had increased redness and reduced sugar-acid-ratios and were firmer, thus improving the commercially important shelf life. Longer shelf life reduced fruit loss by at least 11%. This is accounting for 0.32 billion US$ of the 1.44 billion US$ provided by bee pollination to the total value of 2.90 billion US$ made with strawberry selling in the European Union 2009. The fruit quality and yield effects are driven by the pollination-mediated production of hormonal growth regulators, which occur in several pollination-dependent crops. Thus, our comprehensive findings should be transferable to a wide range of crops and demonstrate bee pollination to be a hitherto underestimated but vital and economically important determinant of fruit quality. 2014 Proceedings of the Royal Society B: Biological Sciences 281 1775 urn:nbn:de:bvb:20-opus-120797 10.1098/rspb.2013.2440 Theodor-Boveri-Institut für Biowissenschaften OPUS4-12143 Wissenschaftlicher Artikel Stefanovic, Sonia; Barnett, Phil; van Duijvenboden, Karel; Weber, David; Gessler, Manfred; Christoffels, Vincent M. GATA-dependent regulatory switches establish atrioventricular canal specificity during heart development The embryonic vertebrate heart tube develops an atrioventricular canal that divides the atrial and ventricular chambers, forms atrioventricular conduction tissue and organizes valve development. Here we assess the transcriptional mechanism underlying this localized differentiation process. We show that atrioventricular canal-specific enhancers are GATA-binding site-dependent and act as switches that repress gene activity in the chambers. We find that atrioventricular canal-specific gene loci are enriched in H3K27ac, a marker of active enhancers, in atrioventricular canal tissue and depleted in H3K27ac in chamber tissue. In the atrioventricular canal, Gata4 activates the enhancers in synergy with Bmp2/Smad signalling, leading to H3K27 acetylation. In contrast, in chambers, Gata4 cooperates with pan-cardiac Hdac1 and Hdac2 and chamber-specific Hey1 and Hey2, leading to H3K27 deacetylation and repression. We conclude that atrioventricular canal-specific enhancers are platforms integrating cardiac transcription factors, broadly active histone modification enzymes and localized co-factors to drive atrioventricular canal-specific gene activity. 2014 Nature Communications 5 3680 urn:nbn:de:bvb:20-opus-121437 10.1038/ncomms4680 Theodor-Boveri-Institut für Biowissenschaften OPUS4-12112 Wissenschaftlicher Artikel Zhan, Hong; Stanciauskas, Ramunas; Stigloher, Christian; Dizon, Kevin K.; Jospin, Maelle; Bessereau, Jean-Luis; Pinaud, Fabien In vivo single-molecule imaging identifies altered dynamics of calcium channels in dystrophin-mutant C. elegans Single-molecule (SM) fluorescence microscopy allows the imaging of biomolecules in cultured cells with a precision of a few nanometres but has yet to be implemented in living adult animals. Here we used split-GFP (green fluorescent protein) fusions and complementation-activated light microscopy (CALM) for subresolution imaging of individual membrane proteins in live Caenorhabditis elegans (C. elegans). In vivo tissue-specific SM tracking of transmembrane CD4 and voltage-dependent Ca(2+) channels (VDCC) was achieved with a precision of 30 nm within neuromuscular synapses and at the surface of muscle cells in normal and dystrophin-mutant worms. Through diffusion analyses, we reveal that dystrophin is involved in modulating the confinement of VDCC within sarcolemmal membrane nanodomains in response to varying tonus of C. elegans body-wall muscles. CALM expands the applications of SM imaging techniques beyond the petri dish and opens the possibility to explore the molecular basis of homeostatic and pathological cellular processes with subresolution precision, directly in live animals. 2014 Nature Communications 5 4974 urn:nbn:de:bvb:20-opus-121125 10.1038/ncomms5974 Theodor-Boveri-Institut für Biowissenschaften OPUS4-11943 Wissenschaftlicher Artikel Dusik, Verena; Senthilan, Pingkalai R.; Mentzel, Benjamin; Hartlieb, Heiko; Wülbeck, Corina; Yoshii, Taishi; Raabe, Thomas; Helfrich-Förster, Charlotte The MAP Kinase p38 Is Part of Drosophila melanogaster's Circadian Clock All organisms have to adapt to acute as well as to regularly occurring changes in the environment. To deal with these major challenges organisms evolved two fundamental mechanisms: the p38 mitogen-activated protein kinase (MAPK) pathway, a major stress pathway for signaling stressful events, and circadian clocks to prepare for the daily environmental changes. Both systems respond sensitively to light. Recent studies in vertebrates and fungi indicate that p38 is involved in light-signaling to the circadian clock providing an interesting link between stress-induced and regularly rhythmic adaptations of animals to the environment, but the molecular and cellular mechanisms remained largely unknown. Here, we demonstrate by immunocytochemical means that p38 is expressed in Drosophila melanogaster's clock neurons and that it is activated in a clock-dependent manner. Surprisingly, we found that p38 is most active under darkness and, besides its circadian activation, additionally gets inactivated by light. Moreover, locomotor activity recordings revealed that p38 is essential for a wild-type timing of evening activity and for maintaining ∼ 24 h behavioral rhythms under constant darkness: flies with reduced p38 activity in clock neurons, delayed evening activity and lengthened the period of their free-running rhythms. Furthermore, nuclear translocation of the clock protein Period was significantly delayed on the expression of a dominant-negative form of p38b in Drosophila's most important clock neurons. Western Blots revealed that p38 affects the phosphorylation degree of Period, what is likely the reason for its effects on nuclear entry of Period. In vitro kinase assays confirmed our Western Blot results and point to p38 as a potential "clock kinase" phosphorylating Period. Taken together, our findings indicate that the p38 MAP Kinase is an integral component of the core circadian clock of Drosophila in addition to playing a role in stress-input pathways. 2014 e1004565 PLoS Genetics 10 8 urn:nbn:de:bvb:20-opus-119433 10.1371/journal.pgen.1004565 Institut für Medizinische Strahlenkunde und Zellforschung