@article{RosenbaumSchickWollbornetal.2016, author = {Rosenbaum, Corinna and Schick, Martin Alexander and Wollborn, Jakob and Heider, Andreas and Scholz, Claus-J{\"u}rgen and Cecil, Alexander and Niesler, Beate and Hirrlinger, Johannes and Walles, Heike and Metzger, Marco}, title = {Activation of Myenteric Glia during Acute Inflammation In Vitro and In Vivo}, series = {PLoS One}, volume = {11}, journal = {PLoS One}, number = {3}, doi = {10.1371/journal.pone.0151335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146544}, pages = {e0151335}, year = {2016}, abstract = {Background Enteric glial cells (EGCs) are the main constituent of the enteric nervous system and share similarities with astrocytes from the central nervous system including their reactivity to an inflammatory microenvironment. Previous studies on EGC pathophysiology have specifically focused on mucosal glia activation and its contribution to mucosal inflammatory processes observed in the gut of inflammatory bowel disease (IBD) patients. In contrast knowledge is scarce on intestinal inflammation not locally restricted to the mucosa but systemically affecting the intestine and its effect on the overall EGC network. Methods and Results In this study, we analyzed the biological effects of a systemic LPS-induced hyperinflammatory insult on overall EGCs in a rat model in vivo, mimicking the clinical situation of systemic inflammation response syndrome (SIRS). Tissues from small and large intestine were removed 4 hours after systemic LPS-injection and analyzed on transcript and protein level. Laser capture microdissection was performed to study plexus-specific gene expression alterations. Upon systemic LPS-injection in vivo we observed a rapid and dramatic activation of Glial Fibrillary Acidic Protein (GFAP)-expressing glia on mRNA level, locally restricted to the myenteric plexus. To study the specific role of the GFAP subpopulation, we established flow cytometry-purified primary glial cell cultures from GFAP promotor-driven EGFP reporter mice. After LPS stimulation, we analyzed cytokine secretion and global gene expression profiles, which were finally implemented in a bioinformatic comparative transcriptome analysis. Enriched GFAP+ glial cells cultured as gliospheres secreted increased levels of prominent inflammatory cytokines upon LPS stimulation. Additionally, a shift in myenteric glial gene expression profile was induced that predominantly affected genes associated with immune response. Conclusion and Significance Our findings identify the myenteric GFAP-expressing glial subpopulation as particularly susceptible and responsive to acute systemic inflammation of the gut wall and complement knowledge on glial involvement in mucosal inflammation of the intestine.}, language = {en} } @article{SchulSchmittRegnerietal.2013, author = {Schul, Daniela and Schmitt, Alexandra and Regneri, Janine and Schartl, Manfred and Wagner, Toni Ulrich}, title = {Bursted BMP Triggered Receptor Kinase Activity Drives Smad1 Mediated Long-Term Target Gene Oscillation in c2c12 Cells}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0059442}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130131}, pages = {e59442}, year = {2013}, abstract = {Bone Morphogenetic Proteins (BMPs) are important growth factors that regulate many cellular processes. During embryogenesis they act as morphogens and play a critical role during organ development. They influence cell fates via concentration-gradients in the embryos where cells transduce this extracellular information into gene expression profiles and cell fate decisions. How receiving cells decode and quantify BMP2/4 signals is hardly understood. There is little data on the quantitative relationships between signal input, transducing molecules, their states and location, and ultimately their ability to integrate graded systemic inputs and generate qualitative responses. Understanding this signaling network on a quantitative level should be considered a prerequisite for efficient pathway modulation, as the BMP pathway is a prime target for therapeutic invention. Hence, we quantified the spatial distribution of the main signal transducer of the BMP2/4 pathway in response to different types and levels of stimuli in c2c12 cells. We found that the subcellular localization of Smad1 is independent of ligand concentration. In contrast, Smad1 phosphorylation levels relate proportionally to BMP2 ligand concentrations and they are entirely located in the nucleus. Interestingly, we found that BMP2 stimulates target gene expression in non-linear, wave-like forms. Amplitudes showed a clear concentration-dependency, for sustained and transient stimulation. We found that even burst-stimulation triggers gene-expression wave-like modulations that are detectable for at least 30 h. Finally, we show here that target gene expression oscillations depend on receptor kinase activity, as the kinase drives further expression pulses without receptor reactivation and the target gene expression breaks off after inhibitor treatment in c2c12 cells.}, language = {en} } @article{PascoalinoDindarVieiradaRochaetal.2014, author = {Pascoalino, Bruno and Dindar, G{\"u}lcin and Vieira-da-Rocha, Jo{\~a}o P. and Machado, Carlos Renato and Janzen, Christian J. and Schenkman, Sergio}, title = {Characterization of two different Asf1 histone chaperones with distinct cellular localizations and functions in Trypanosoma brucei}, series = {Nucleic Acids Research}, volume = {42}, journal = {Nucleic Acids Research}, number = {5}, issn = {1362-4962}, doi = {10.1093/nar/gkt1267}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117220}, pages = {2906-2918}, year = {2014}, abstract = {The anti-silencing function protein 1 (Asf1) is a chaperone that forms a complex with histones H3 and H4 facilitating dimer deposition and removal from chromatin. Most eukaryotes possess two different Asf1 chaperones but their specific functions are still unknown. Trypanosomes, a group of early-diverged eukaryotes, also have two, but more divergent Asf1 paralogs than Asf1 of higher eukaryotes. To unravel possible different functions, we characterized the two Asf1 proteins in Trypanosoma brucei. Asf1A is mainly localized in the cytosol but translocates to the nucleus in S phase. In contrast, Asf1B is predominantly localized in the nucleus, as described for other organisms. Cytosolic Asf1 knockdown results in accumulation of cells in early S phase of the cell cycle, whereas nuclear Asf1 knockdown arrests cells in S/G2 phase. Overexpression of cytosolic Asf1 increases the levels of histone H3 and H4 acetylation. In contrast to cytosolic Asf1, overexpression of nuclear Asf1 causes less pronounced growth defects in parasites exposed to genotoxic agents, prompting a function in chromatin remodeling in response to DNA damage. Only the cytosolic Asf1 interacts with recombinant H3/H4 dimers in vitro. These findings denote the early appearance in evolution of distinguishable functions for the two Asf1 chaperons in trypanosomes.}, language = {en} } @article{SchubertSpahnKneitzetal.2013, author = {Schubert, Maria and Spahn, Martin and Kneitz, Susanne and Scholz, Claus J{\"u}rgen and Joniau, Steven and Stroebel, Philipp and Riedmiller, Hubertus and Kneitz, Burkhard}, title = {Distinct microRNA Expression Profile in Prostate Cancer Patients with Early Clinical Failure and the Impact of let-7 as Prognostic Marker in High-Risk Prostate Cancer}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0065064}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96825}, year = {2013}, abstract = {Background The identification of additional prognostic markers to improve risk stratification and to avoid overtreatment is one of the most urgent clinical needs in prostate cancer (PCa). MicroRNAs, being important regulators of gene expression, are promising biomarkers in various cancer entities, though the impact as prognostic predictors in PCa is poorly understood. The aim of this study was to identify specific miRNAs as potential prognostic markers in high-risk PCa and to validate their clinical impact. Methodology and Principal Findings We performed miRNA-microarray analysis in a high-risk PCa study group selected by their clinical outcome (clinical progression free survival (CPFS) vs. clinical failure (CF)). We identified seven candidate miRNAs (let-7a/b/c, miR-515-3p/5p, -181b, -146b, and -361) that showed differential expression between both groups. Further qRT-PCR analysis revealed down-regulation of members of the let-7 family in the majority of a large, well-characterized high-risk PCa cohort (n = 98). Expression of let-7a/b/and -c was correlated to clinical outcome parameters of this group. While let-7a showed no association or correlation with clinical relevant data, let-7b and let-7c were associated with CF in PCa patients and functioned partially as independent prognostic marker. Validation of the data using an independent high-risk study cohort revealed that let-7b, but not let-7c, has impact as an independent prognostic marker for BCR and CF. Furthermore, we identified HMGA1, a non-histone protein, as a new target of let-7b and found correlation of let-7b down-regulation with HMGA1 over-expression in primary PCa samples. Conclusion Our findings define a distinct miRNA expression profile in PCa cases with early CF and identified let-7b as prognostic biomarker in high-risk PCa. This study highlights the importance of let-7b as tumor suppressor miRNA in high-risk PCa and presents a basis to improve individual therapy for high-risk PCa patients.}, language = {en} } @article{DeekenGohlkeScholzetal.2013, author = {Deeken, Rosalia and Gohlke, Jochen and Scholz, Claus-Juergen and Kneitz, Susanne and Weber, Dana and Fuchs, Joerg and Hedrich, Rainer}, title = {DNA Methylation Mediated Control of Gene Expression Is Critical for Development of Crown Gall Tumors}, series = {PLoS Genetics}, journal = {PLoS Genetics}, doi = {10.1371/journal.pgen.1003267}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96318}, year = {2013}, abstract = {Crown gall tumors develop after integration of the T-DNA of virulent Agrobacterium tumefaciens strains into the plant genome. Expression of the T-DNA-encoded oncogenes triggers proliferation and differentiation of transformed plant cells. Crown gall development is known to be accompanied by global changes in transcription, metabolite levels, and physiological processes. High levels of abscisic acid (ABA) in crown galls regulate expression of drought stress responsive genes and mediate drought stress acclimation, which is essential for wild-type-like tumor growth. An impact of epigenetic processes such as DNA methylation on crown gall development has been suggested; however, it has not yet been investigated comprehensively. In this study, the methylation pattern of Arabidopsis thaliana crown galls was analyzed on a genome-wide scale as well as at the single gene level. Bisulfite sequencing analysis revealed that the oncogenes Ipt, IaaH, and IaaM were unmethylated in crown galls. Nevertheless, the oncogenes were susceptible to siRNA-mediated methylation, which inhibited their expression and subsequently crown gall growth. Genome arrays, hybridized with methylated DNA obtained by immunoprecipitation, revealed a globally hypermethylated crown gall genome, while promoters were rather hypomethylated. Mutants with reduced non-CG methylation developed larger tumors than the wild-type controls, indicating that hypermethylation inhibits plant tumor growth. The differential methylation pattern of crown galls and the stem tissue from which they originate correlated with transcriptional changes. Genes known to be transcriptionally inhibited by ABA and methylated in crown galls became promoter methylated upon treatment of A. thaliana with ABA. This suggests that the high ABA levels in crown galls may mediate DNA methylation and regulate expression of genes involved in drought stress protection. In summary, our studies provide evidence that epigenetic processes regulate gene expression, physiological processes, and the development of crown gall tumors.}, language = {en} } @article{WolfAkrapMargetal.2013, author = {Wolf, Annette and Akrap, Nina and Marg, Berenice and Galliardt, Helena and Heiligentag, Martyna and Humpert, Fabian and Sauer, Markus and Kaltschmidt, Barbara and Kaltschmidt, Christian and Seidel, Thorsten}, title = {Elements of Transcriptional Machinery Are Compatible among Plants and Mammals}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0053737}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131203}, pages = {e53737}, year = {2013}, abstract = {In the present work, the objective has been to analyse the compatibility of plant and human transcriptional machinery. The experiments revealed that nuclear import and export are conserved among plants and mammals. Further it has been shown that transactivation of a human promoter occurs by human transcription factor NF-\(\kappa\) B in plant cells, demonstrating that the transcriptional machinery is highly conserved in both kingdoms. Functionality was also seen for regulatory elements of NF-\(\kappa\) B such as its inhibitor I\(\kappa\)B isoform \(\alpha\) that negatively regulated the transactivation activity of the p50/RelA heterodimer by interaction with NF-\(\kappa\)B in plant cells. Nuclear export of RelA could be demonstrated by FRAP-measurements so that RelA shows nucleo-cytoplasmic shuttling as reported for RelA in mammalian cells. The data reveals the high level of compatibility of human transcriptional elements with the plant transcriptional machinery. Thus, Arabidopsis thaliana mesophyll protoplasts might provide a new heterologous expression system for the investigation of the human NF-\(\kappa\)B signaling pathways. The system successfully enabled the controlled manipulation of NF-\(\kappa\)B activity. We suggest the plant protoplast system as a tool for reconstitution and analyses of mammalian pathways and for direct observation of responses to e. g. pharmaceuticals. The major advantage of the system is the absence of interference with endogenous factors that affect and crosstalk with the pathway.}, language = {en} } @article{MortonFliesserDittrichetal.2014, author = {Morton, Charles Oliver and Fliesser, Mirjam and Dittrich, Marcus and M{\"u}ller, Tobias and Bauer, Ruth and Kneitz, Susanne and Hope, William and Rogers, Thomas Richard and Einsele, Hermann and L{\"o}ffler, J{\"u}rgen}, title = {Gene Expression Profiles of Human Dendritic Cells Interacting with Aspergillus fumigatus in a Bilayer Model of the Alveolar Epithelium/Endothelium Interface}, doi = {10.1371/journal.pone.0098279}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112893}, year = {2014}, abstract = {The initial stages of the interaction between the host and Aspergillus fumigatus at the alveolar surface of the human lung are critical in the establishment of aspergillosis. Using an in vitro bilayer model of the alveolus, including both the epithelium (human lung adenocarcinoma epithelial cell line, A549) and endothelium (human pulmonary artery epithelial cells, HPAEC) on transwell membranes, it was possible to closely replicate the in vivo conditions. Two distinct sub-groups of dendritic cells (DC), monocyte-derived DC (moDC) and myeloid DC (mDC), were included in the model to examine immune responses to fungal infection at the alveolar surface. RNA in high quantity and quality was extracted from the cell layers on the transwell membrane to allow gene expression analysis using tailored custom-made microarrays, containing probes for 117 immune-relevant genes. This microarray data indicated minimal induction of immune gene expression in A549 alveolar epithelial cells in response to germ tubes of A. fumigatus. In contrast, the addition of DC to the system greatly increased the number of differentially expressed immune genes. moDC exhibited increased expression of genes including CLEC7A, CD209 and CCL18 in the absence of A. fumigatus compared to mDC. In the presence of A. fumigatus, both DC subgroups exhibited up-regulation of genes identified in previous studies as being associated with the exposure of DC to A. fumigatus and exhibiting chemotactic properties for neutrophils, including CXCL2, CXCL5, CCL20, and IL1B. This model closely approximated the human alveolus allowing for an analysis of the host pathogen interface that complements existing animal models of IA.}, language = {en} } @article{LealSchwebsBriggsetal.2020, author = {Leal, Andrea Zurita and Schwebs, Marie and Briggs, Emma and Weisert, Nadine and Reis, Helena and Lemgruber, Leondro and Luko, Katarina and Wilkes, Jonathan and Butter, Falk and McCulloch, Richard and Janzen, Christian J.}, title = {Genome maintenance functions of a putative Trypanosoma brucei translesion DNA polymerase include telomere association and a role in antigenic variation}, series = {Nucleic Acids Research}, volume = {48}, journal = {Nucleic Acids Research}, number = {17}, doi = {10.1093/nar/gkaa686}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230579}, pages = {9660-9680}, year = {2020}, abstract = {Maintenance of genome integrity is critical to guarantee transfer of an intact genome from parent to off-spring during cell division. DNA polymerases (Pols) provide roles in both replication of the genome and the repair of a wide range of lesions. Amongst replicative DNA Pols, translesion DNA Pols play a particular role: replication to bypass DNA damage. All cells express a range of translesion Pols, but little work has examined their function in parasites, including whether the enzymes might contribute to host-parasite interactions. Here, we describe a dual function of one putative translesion Pol in African trypanosomes, which we now name TbPolIE. Previously, we demonstrated that TbPolIE is associated with telomeric sequences and here we show that RNAi-mediated depletion of TbPolIE transcripts results in slowed growth, altered DNA content, changes in cell morphology, and increased sensitivity to DNA damaging agents. We also show that TbPolIE displays pronounced localization at the nuclear periphery, and that its depletion leads to chromosome segregation defects and increased levels of endogenous DNA damage. Finally, we demonstrate that TbPolIE depletion leads to deregulation of telomeric variant surface glycoprotein genes, linking the function of this putative translesion DNA polymerase to host immune evasion by antigenic variation.}, language = {en} } @article{PfeifferKruegerMaierhoferetal.2016, author = {Pfeiffer, Susanne and Kr{\"u}ger, Jacqueline and Maierhofer, Anna and B{\"o}ttcher, Yvonne and Kl{\"o}ting, Nora and El Hajj, Nady and Schleinitz, Dorit and Sch{\"o}n, Michael R. and Dietrich, Arne and Fasshauer, Mathias and Lohmann, Tobias and Dreßler, Miriam and Stumvoll, Michael and Haaf, Thomas and Bl{\"u}her, Matthias and Kovacs, Peter}, title = {Hypoxia-inducible factor 3A gene expression and methylation in adipose tissue is related to adipose tissue dysfunction}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {27969}, doi = {10.1038/srep27969}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167662}, year = {2016}, abstract = {Recently, a genome-wide analysis identified DNA methylation of the HIF3A (hypoxia-inducible factor 3A) as strongest correlate of BMI. Here we tested the hypothesis that HIF3A mRNA expression and CpG-sites methylation in adipose tissue (AT) and genetic variants in HIF3A are related to parameters of AT distribution and function. In paired samples of subcutaneous AT (SAT) and visceral AT (VAT) from 603 individuals, we measured HIF3A mRNA expression and analyzed its correlation with obesity and related traits. In subgroups of individuals, we investigated the effects on HIF3A genetic variants on its AT expression (N = 603) and methylation of CpG-sites (N = 87). HIF3A expression was significantly higher in SAT compared to VAT and correlated with obesity and parameters of AT dysfunction (including CRP and leucocytes count). HIF3A methylation at cg22891070 was significantly higher in VAT compared to SAT and correlated with BMI, abdominal SAT and VAT area. Rs8102595 showed a nominal significant association with AT HIF3A methylation levels as well as with obesity and fat distribution. HIF3A expression and methylation in AT are fat depot specific, related to obesity and AT dysfunction. Our data support the hypothesis that HIF pathways may play an important role in the development of AT dysfunction in obesity.}, language = {en} } @article{BuchnerBlancoRedondoBunzetal.2013, author = {Buchner, Erich and Blanco Redondo, Beatriz and Bunz, Melanie and Halder, Partho and Sadanandappa, Madhumala K. and M{\"u}hlbauer, Barbara and Erwin, Felix and Hofbauer, Alois and Rodrigues, Veronica and VijayRaghavan, K. and Ramaswami, Mani and Rieger, Dirk and Wegener, Christian and F{\"o}rster, Charlotte}, title = {Identification and Structural Characterization of Interneurons of the Drosophila Brain by Monoclonal Antibodies of the W{\"u}rzburg Hybridoma Library}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075420}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97109}, year = {2013}, abstract = {Several novel synaptic proteins have been identified by monoclonal antibodies (mAbs) of the W{\"u}rzburg hybridoma library generated against homogenized Drosophila brains, e.g. cysteine string protein, synapse-associated protein of 47 kDa, and Bruchpilot. However, at present no routine technique exists to identify the antigens of mAbs of our library that label only a small number of cells in the brain. Yet these antibodies can be used to reproducibly label and thereby identify these cells by immunohistochemical staining. Here we describe the staining patterns in the Drosophila brain for ten mAbs of the W{\"u}rzburg hybridoma library. Besides revealing the neuroanatomical structure and distribution of ten different sets of cells we compare the staining patterns with those of antibodies against known antigens and GFP expression patterns driven by selected Gal4 lines employing regulatory sequences of neuronal genes. We present examples where our antibodies apparently stain the same cells in different Gal4 lines suggesting that the corresponding regulatory sequences can be exploited by the split-Gal4 technique for transgene expression exclusively in these cells. The detection of Gal4 expression in cells labeled by mAbs may also help in the identification of the antigens recognized by the antibodies which then in addition to their value for neuroanatomy will represent important tools for the characterization of the antigens. Implications and future strategies for the identification of the antigens are discussed.}, language = {en} }