TY - JOUR A1 - Moll, Corinna A1 - Reboredo, Jenny A1 - Schwarz, Thomas A1 - Appelt, Antje A1 - Schürlein, Sebastian A1 - Walles, Heike A1 - Nietzer, Sarah T1 - Tissue Engineering of a Human 3D in vitro Tumor Test System JF - Journal of Visualized Experiments N2 - Cancer is one of the leading causes of death worldwide. Current therapeutic strategies are predominantly developed in 2D culture systems, which inadequately reflect physiological conditions in vivo. Biological 3D matrices provide cells an environment in which cells can self-organize, allowing the study of tissue organization and cell differentiation. Such scaffolds can be seeded with a mixture of different cell types to study direct 3D cell-cell-interactions. To mimic the 3D complexity of cancer tumors, our group has developed a 3D in vitro tumor test system. Our 3D tissue test system models the in vivo situation of malignant peripheral nerve sheath tumors (MPNSTs), which we established with our decellularized porcine jejunal segment derived biological vascularized scaffold (BioVaSc). In our model, we reseeded a modified BioVaSc matrix with primary fibroblasts, microvascular endothelial cells (mvECs) and the S462 tumor cell line For static culture, the vascular structure of the BioVaSc is removed and the remaining scaffold is cut open on one side (Small Intestinal Submucosa SIS-Muc). The resulting matrix is then fixed between two metal rings (cell crowns). Another option is to culture the cell-seeded SIS-Muc in a flow bioreactor system that exposes the cells to shear stress. Here, the bioreactor is connected to a peristaltic pump in a self-constructed incubator. A computer regulates the arterial oxygen and nutrient supply via parameters such as blood pressure, temperature, and flow rate. This setup allows for a dynamic culture with either pressure-regulated pulsatile or constant flow. In this study, we could successfully establish both a static and dynamic 3D culture system for MPNSTs. The ability to model cancer tumors in a more natural 3D environment will enable the discovery, testing, and validation of future pharmaceuticals in a human-like model. KW - bioengineering KW - biomedical engineering KW - tissue engineering KW - biotechnology KW - cultured KW - tumor cells KW - cell culture KW - 3D in vitro models KW - bioreactor KW - dynamic culture conditions KW - tumor test system KW - primary cell isolation KW - BioVaSc KW - decellularization KW - equipment and supplies KW - cellular microenvironment KW - culture techniques KW - cell engineering KW - anatomy KW - physiology KW - molecular biology KW - cellular biology Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132277 UR - http://www.jove.com/video/50460 VL - 78 IS - e50460 ER - TY - JOUR A1 - Stefanovic, Sonia A1 - Barnett, Phil A1 - van Duijvenboden, Karel A1 - Weber, David A1 - Gessler, Manfred A1 - Christoffels, Vincent M. T1 - GATA-dependent regulatory switches establish atrioventricular canal specificity during heart development JF - Nature Communications N2 - 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. KW - biological sciences KW - developmental biology KW - molecular biology Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-121437 SN - 2041-1723 VL - 5 IS - 3680 ER - TY - JOUR A1 - Adolfi, Mateus C. A1 - Herpin, Amaury A1 - Regensburger, Martina A1 - Sacquegno, Jacopo A1 - Waxman, Joshua S. A1 - Schartl, Manfred T1 - Retinoic acid and meiosis induction in adult versus embryonic gonads of medaka JF - Scientific Reports N2 - In vertebrates, one of the first recognizable sex differences in embryos is the onset of meiosis, known to be regulated by retinoic acid (RA) in mammals. We investigated in medaka a possible meiotic function of RA during the embryonic sex determination (SD) period and in mature gonads. We found RA mediated transcriptional activation in germ cells of both sexes much earlier than the SD stage, however, no such activity during the critical stages of SD. In adults, expression of the RA metabolizing enzymes indicates sexually dimorphic RA levels. In testis, RA acts directly in Sertoli, Leydig and pre-meiotic germ cells. In ovaries, RA transcriptional activity is highest in meiotic oocytes. Our results show that RA plays an important role in meiosis induction and gametogenesis in adult medaka but contrary to common expectations, not for initiating the first meiosis in female germ cells at the SD stage. KW - developmental biology KW - molecular biology Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147843 VL - 6 ER - TY - JOUR A1 - Ullrich, M A1 - Weber, M A1 - Post, A M A1 - Popp, S A1 - Grein, J A1 - Zechner, M A1 - González, H Guerrero A1 - Kreis, A A1 - Schmitt, A G A1 - Üҫeyler, N A1 - Lesch, K-P A1 - Schuh, K T1 - OCD-like behavior is caused by dysfunction of thalamo-amygdala circuits and upregulated TrkB/ERK-MAPK signaling as a result of SPRED2 deficiency JF - Molecular Psychiatry N2 - Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disease affecting about 2% of the general population. It is characterized by persistent intrusive thoughts and repetitive ritualized behaviors. While gene variations, malfunction of cortico-striato-thalamo-cortical (CSTC) circuits, and dysregulated synaptic transmission have been implicated in the pathogenesis of OCD, the underlying mechanisms remain largely unknown. Here we show that OCD-like behavior in mice is caused by deficiency of SPRED2, a protein expressed in various brain regions and a potent inhibitor of Ras/ERK-MAPK signaling. Excessive self-grooming, reflecting OCD-like behavior in rodents, resulted in facial skin lesions in SPRED2 knockout (KO) mice. This was alleviated by treatment with the selective serotonin reuptake inhibitor fluoxetine. In addition to the previously suggested involvement of cortico-striatal circuits, electrophysiological measurements revealed altered transmission at thalamo-amygdala synapses and morphological differences in lateral amygdala neurons of SPRED2 KO mice. Changes in synaptic function were accompanied by dysregulated expression of various pre- and postsynaptic proteins in the amygdala. This was a result of altered gene transcription and triggered upstream by upregulated tropomyosin receptor kinase B (TrkB)/ERK-MAPK signaling in the amygdala of SPRED2 KO mice. Pathway overactivation was mediated by increased activity of TrkB, Ras, and ERK as a specific result of SPRED2 deficiency and not elicited by elevated brain-derived neurotrophic factor levels. Using the MEK inhibitor selumetinib, we suppressed TrkB/ERK-MAPK pathway activity in vivo and reduced OCD-like grooming in SPRED2 KO mice. Altogether, this study identifies SPRED2 as a promising new regulator, TrkB/ERK-MAPK signaling as a novel mediating mechanism, and thalamo-amygdala synapses as critical circuitry involved in the pathogenesis of OCD. KW - molecular biology KW - neuroscience KW - physiology KW - psychiatric disorders Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232096 VL - 23 ER - TY - JOUR A1 - Vujanić, Gordan M. A1 - Gessler, Manfred A1 - Ooms, Ariadne H. A. G. A1 - Collini, Paola A1 - Coulomb-l'Hermine, Aurore A1 - D'Hooghe, Ellen A1 - de Krijger, Ronald R. A1 - Perotti, Daniela A1 - Pritchard-Jones, Kathy A1 - Vokuhl, Christian A1 - van den Heuvel-Eibrink, Marry M. A1 - Graf, Norbert T1 - The UMBRELLA SIOP–RTSG 2016 Wilms tumour pathology and molecular biology protocol JF - Nature Reviews Urology N2 - On the basis of the results of previous national and international trials and studies, the Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP–RTSG) has developed a new study protocol for paediatric renal tumours: the UMBRELLA SIOP–RTSG 2016 protocol (the UMBRELLA protocol). Currently, the overall outcomes of patients with Wilms tumour are excellent, but subgroups with poor prognosis and increased relapse rates still exist. The identification of these subgroups is of utmost importance to improve treatment stratification, which might lead to reduction of the direct and late effects of chemotherapy. The UMBRELLA protocol aims to validate new prognostic factors, such as blastemal tumour volume and molecular markers, to further improve outcome. To achieve this aim, large, international, high-quality databases are needed, which dictate optimization and international harmonization of specimen handling and comprehensive sampling of biological material, refine definitions and improve logistics for expert review. To promote broad implementation of the UMBRELLA protocol, the updated SIOP–RTSG pathology and molecular biology protocol for Wilms tumours has been outlined, which is a consensus from the SIOP–RTSG pathology panel. KW - molecular biology KW - paediatric cancer KW - pathology KW - renal cancer Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233265 VL - 15 ER - TY - JOUR A1 - Goos, Carina A1 - Dejung, Mario A1 - Wehman, Ann M. A1 - M-Natus, Elisabeth A1 - Schmidt, Johannes A1 - Sunter, Jack A1 - Engstler, Markus A1 - Butter, Falk A1 - Kramer, Susanne T1 - Trypanosomes can initiate nuclear export co-transcriptionally JF - Nucleic Acids Research N2 - The nuclear envelope serves as important messenger RNA (mRNA) surveillance system. In yeast and human, several control systems act in parallel to prevent nuclear export of unprocessed mRNAs. Trypanosomes lack homologues to most of the involved proteins and their nuclear mRNA metabolism is non-conventional exemplified by polycistronic transcription and mRNA processing by trans-splicing. We here visualized nuclear export in trypanosomes by intra- and intermolecular multi-colour single molecule FISH. We found that, in striking contrast to other eukaryotes, the initiation of nuclear export requires neither the completion of transcription nor splicing. Nevertheless, we show that unspliced mRNAs are mostly prevented from reaching the nucleus-distant cytoplasm and instead accumulate at the nuclear periphery in cytoplasmic nuclear periphery granules (NPGs). Further characterization of NPGs by electron microscopy and proteomics revealed that the granules are located at the cytoplasmic site of the nuclear pores and contain most cytoplasmic RNA-binding proteins but none of the major translation initiation factors, consistent with a function in preventing faulty mRNAs from reaching translation. Our data indicate that trypanosomes regulate the completion of nuclear export, rather than the initiation. Nuclear export control remains poorly understood, in any organism, and the described way of control may not be restricted to trypanosomes. KW - molecular biology KW - nuclear export KW - trypanosomes KW - mRNA KW - nuclear envelope Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177709 VL - 47 IS - 1 ER - TY - JOUR A1 - Lee, Hong-Jen A1 - Li, Chien-Feng A1 - Ruan, Diane A1 - He, Jiabei A1 - Montal, Emily D. A1 - Lorenz, Sonja A1 - Girnun, Geoffrey D. A1 - Chan, Chia-Hsin T1 - Non-proteolytic ubiquitination of Hexokinase 2 by HectH9 controls tumor metabolism and cancer stem cell expansion JF - Nature Communications N2 - Enormous efforts have been made to target metabolic dependencies of cancer cells for developing new therapies. However, the therapeutic efficacy of glycolysis inhibitors is limited due to their inability to elicit cell death. Hexokinase 2 (HK2), via its mitochondrial localization, functions as a central nexus integrating glycolysis activation and apoptosis resilience. Here we identify that K63-linked ubiquitination by HectH9 regulates the mitochondrial localization and function of HK2. Through stable isotope tracer approach and functional metabolic analyses, we show that HectH9 deficiency impedes tumor glucose metabolism and growth by HK2 inhibition. The HectH9/HK2 pathway regulates cancer stem cell (CSC) expansion and CSC-associated chemoresistance. Histological analyses show that HectH9 expression is upregulated and correlated with disease progression in prostate cancer. This work uncovers that HectH9 is a novel regulator of HK2 and cancer metabolism. Targeting HectH9 represents an effective strategy to achieve long-term tumor remission by concomitantly disrupting glycolysis and inducing apoptosis. KW - cancer KW - cancer metabolism KW - molecular biology Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236445 VL - 10 ER - TY - JOUR A1 - Chen, Chunguang A1 - Rawat, Divya A1 - Samikannu, Balaji A1 - Bender, Markus A1 - Preissner, Klaus T. A1 - Linn, Thomas T1 - Platelet glycoprotein VI‐dependent thrombus stabilization is essential for the intraportal engraftment of pancreatic islets JF - American Journal of Transplantation N2 - Platelet activation and thrombus formation have been implicated to be detrimental for intraportal pancreatic islet transplants. The platelet‐specific collagen receptor glycoprotein VI (GPVI) plays a key role in thrombosis through cellular activation and the subsequent release of secondary mediators. In aggregometry and in a microfluidic dynamic assay system modeling flow in the portal vein, pancreatic islets promoted platelet aggregation and triggered thrombus formation, respectively. While platelet GPVI deficiency did not affect the initiation of these events, it was found to destabilize platelet aggregates and thrombi in this process. Interestingly, while no major difference was detected in early thrombus formation after intraportal islet transplantation, genetic GPVI deficiency or acute anti‐GPVI treatment led to an inferior graft survival and function in both syngeneic mouse islet transplantation and xenogeneic human islet transplantation models. These results demonstrate that platelet GPVI signaling is indispensable in stable thrombus formation induced by pancreatic islets. GPVI deficiency resulted in thrombus destabilization and inferior islet engraftment indicating that thrombus formation is necessary for a successful intraportal islet transplantation in which platelets are active modulators. KW - basic (laboratory) research / science KW - coagulation and hemostasis KW - graft survival KW - islet transplantation KW - molecular biology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224471 VL - 21 SP - 2079 EP - 2089 ER - TY - JOUR A1 - Hurd, Paul J. A1 - Grübel, Kornelia A1 - Wojciechowski, Marek A1 - Maleszka, Ryszard A1 - Rössler, Wolfgang T1 - Novel structure in the nuclei of honey bee brain neurons revealed by immunostaining JF - Scientific Reports N2 - In the course of a screen designed to produce antibodies (ABs) with affinity to proteins in the honey bee brain we found an interesting AB that detects a highly specific epitope predominantly in the nuclei of Kenyon cells (KCs). The observed staining pattern is unique, and its unfamiliarity indicates a novel previously unseen nuclear structure that does not colocalize with the cytoskeletal protein f-actin. A single rod-like assembly, 3.7-4.1 mu m long, is present in each nucleus of KCs in adult brains of worker bees and drones with the strongest immuno-labelling found in foraging bees. In brains of young queens, the labelling is more sporadic, and the rod-like structure appears to be shorter (similar to 2.1 mu m). No immunostaining is detectable in worker larvae. In pupal stage 5 during a peak of brain development only some occasional staining was identified. Although the cellular function of this unexpected structure has not been determined, the unusual distinctiveness of the revealed pattern suggests an unknown and potentially important protein assembly. One possibility is that this nuclear assembly is part of the KCs plasticity underlying the brain maturation in adult honey bees. Because no labelling with this AB is detectable in brains of the fly Drosophila melanogaster and the ant Camponotus floridanus, we tentatively named this antibody AmBNSab (Apis mellifera Brain Neurons Specific antibody). Here we report our results to make them accessible to a broader community and invite further research to unravel the biological role of this curious nuclear structure in the honey bee central brain. KW - mushroom body calyx KW - synaptic complexes KW - bodies KW - insect KW - plasticity KW - insights KW - genome KW - model KW - proteins KW - methylation KW - biological techniques KW - cell biology KW - developmental biology KW - molecular biology KW - neuroscience Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260059 VL - 11 ER - TY - JOUR A1 - Lodha, Manivel A1 - Muchsin, Ihsan A1 - Jürges, Christopher A1 - Juranic Lisnic, Vanda A1 - L’Hernault, Anne A1 - Rutkowski, Andrzej J. A1 - Prusty, Bhupesh K. A1 - Grothey, Arnhild A1 - Milic, Andrea A1 - Hennig, Thomas A1 - Jonjic, Stipan A1 - Friedel, Caroline C. A1 - Erhard, Florian A1 - Dölken, Lars T1 - Decoding murine cytomegalovirus JF - PLOS Pathogens N2 - The genomes of both human cytomegalovirus (HCMV) and murine cytomegalovirus (MCMV) were first sequenced over 20 years ago. Similar to HCMV, the MCMV genome had initially been proposed to harbor ≈170 open reading frames (ORFs). More recently, omics approaches revealed HCMV gene expression to be substantially more complex comprising several hundred viral ORFs. Here, we provide a state-of-the art reannotation of lytic MCMV gene expression based on integrative analysis of a large set of omics data. Our data reveal 365 viral transcription start sites (TiSS) that give rise to 380 and 454 viral transcripts and ORFs, respectively. The latter include 200 small ORFs, some of which represented the most highly expressed viral gene products. By combining TiSS profiling with metabolic RNA labelling and chemical nucleotide conversion sequencing (dSLAM-seq), we provide a detailed picture of the expression kinetics of viral transcription. This not only resulted in the identification of a novel MCMV immediate early transcript encoding the m166.5 ORF, which we termed ie4, but also revealed a group of well-expressed viral transcripts that are induced later than canonical true late genes and contain an initiator element (Inr) but no TATA- or TATT-box in their core promoters. We show that viral upstream ORFs (uORFs) tune gene expression of longer viral ORFs expressed in cis at translational level. Finally, we identify a truncated isoform of the viral NK-cell immune evasin m145 arising from a viral TiSS downstream of the canonical m145 mRNA. Despite being ≈5-fold more abundantly expressed than the canonical m145 protein it was not required for downregulating the NK cell ligand, MULT-I. In summary, our work will pave the way for future mechanistic studies on previously unknown cytomegalovirus gene products in an important virus animal model. KW - virology KW - genetics KW - molecular biology KW - immunology KW - microbiology KW - parasitology KW - murine cytomegalovirus (MCMV) Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350480 SN - 1553-7374 VL - 19 IS - 5 ER - TY - JOUR A1 - Janz, Anna A1 - Walz, Katharina A1 - Cirnu, Alexandra A1 - Surjanto, Jessica A1 - Urlaub, Daniela A1 - Leskien, Miriam A1 - Kohlhaas, Michael A1 - Nickel, Alexander A1 - Brand, Theresa A1 - Nose, Naoko A1 - Wörsdörfer, Philipp A1 - Wagner, Nicole A1 - Higuchi, Takahiro A1 - Maack, Christoph A1 - Dudek, Jan A1 - Lorenz, Kristina A1 - Klopocki, Eva A1 - Ergün, Süleyman A1 - Duff, Henry J. A1 - Gerull, Brenda T1 - Mutations in DNAJC19 cause altered mitochondrial structure and increased mitochondrial respiration in human iPSC-derived cardiomyocytes JF - Molecular Metabolism N2 - Highlights • Loss of DNAJC19's DnaJ domain disrupts cardiac mitochondrial structure, leading to abnormal cristae formation in iPSC-CMs. • Impaired mitochondrial structures lead to an increased mitochondrial respiration, ROS and an elevated membrane potential. • Mutant iPSC-CMs show sarcomere dysfunction and a trend to more arrhythmias, resembling DCMA-associated cardiomyopathy. Background Dilated cardiomyopathy with ataxia (DCMA) is an autosomal recessive disorder arising from truncating mutations in DNAJC19, which encodes an inner mitochondrial membrane protein. Clinical features include an early onset, often life-threatening, cardiomyopathy associated with other metabolic features. Here, we aim to understand the metabolic and pathophysiological mechanisms of mutant DNAJC19 for the development of cardiomyopathy. Methods We generated induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) of two affected siblings with DCMA and a gene-edited truncation variant (tv) of DNAJC19 which all lack the conserved DnaJ interaction domain. The mutant iPSC-CMs and their respective control cells were subjected to various analyses, including assessments of morphology, metabolic function, and physiological consequences such as Ca\(^{2+}\) kinetics, contractility, and arrhythmic potential. Validation of respiration analysis was done in a gene-edited HeLa cell line (DNAJC19tv\(_{HeLa}\)). Results Structural analyses revealed mitochondrial fragmentation and abnormal cristae formation associated with an overall reduced mitochondrial protein expression in mutant iPSC-CMs. Morphological alterations were associated with higher oxygen consumption rates (OCRs) in all three mutant iPSC-CMs, indicating higher electron transport chain activity to meet cellular ATP demands. Additionally, increased extracellular acidification rates suggested an increase in overall metabolic flux, while radioactive tracer uptake studies revealed decreased fatty acid uptake and utilization of glucose. Mutant iPSC-CMs also showed increased reactive oxygen species (ROS) and an elevated mitochondrial membrane potential. Increased mitochondrial respiration with pyruvate and malate as substrates was observed in mutant DNAJC19tv HeLa cells in addition to an upregulation of respiratory chain complexes, while cellular ATP-levels remain the same. Moreover, mitochondrial alterations were associated with increased beating frequencies, elevated diastolic Ca\(^{2+}\) concentrations, reduced sarcomere shortening and an increased beat-to-beat rate variability in mutant cell lines in response to β-adrenergic stimulation. Conclusions Loss of the DnaJ domain disturbs cardiac mitochondrial structure with abnormal cristae formation and leads to mitochondrial dysfunction, suggesting that DNAJC19 plays an essential role in mitochondrial morphogenesis and biogenesis. Moreover, increased mitochondrial respiration, altered substrate utilization, increased ROS production and abnormal Ca\(^{2+}\) kinetics provide insights into the pathogenesis of DCMA-related cardiomyopathy. KW - cell biology KW - molecular biology KW - dilated cardiomyopathy with ataxia KW - genetics KW - metabolism KW - mitochondria KW - OXPHOS KW - ROS KW - contractility Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350393 SN - 2212-8778 VL - 79 ER -