TY - JOUR A1 - Seefried, Lothar A1 - Mueller-Deubert, Sigrid A1 - Schwarz, Thomas A1 - Lind, Thomas A1 - Mentrup, Birgit A1 - Kober, Melanie A1 - Docheva, Denitsa A1 - Liedert, Astrid A1 - Kassem, Moustapha A1 - Ignatius, Anita A1 - Schieker, Matthias A1 - Claes, Lutz A1 - Wilke, Winfried A1 - Jakob, Franz A1 - Ebert, Regina T1 - A small scale cell culture system to analyze mechanobiology using reporter gene constructs and polyurethane dishes N2 - Mechanical forces are translated into biochemical signals and contribute to cell differentiation and phenotype maintenance. Mesenchymal stem cells and their tissuespecific offspring, as osteoblasts and chondrocytes, cells of cardiovascular tissues and lung cells are sensitive to mechanical loading but molecules and mechanisms involved have to be unraveled. It is well established that cellular mechanotransduction is mediated e.g. by activation of the transcription factor SP1 and by kinase signaling cascades resulting in the activation of the AP1 complex. To investigate cellular mechanisms involved in mechanotransduction and to analyze substances, which modulate cellular mechanosensitivity reporter gene constructs, which can be transfected into cells of interest might be helpful. Suitable small-scale bioreactor systems and mechanosensitive reporter gene constructs are lacking. To analyze the molecular mechanisms of mechanotransduction and its crosstalk with biochemically induced signal transduction, AP1 and SP1 luciferase reporter gene constructs were cloned and transfected into various cell lines and primary cells. A newly developed bioreactor and small-scale 24-well polyurethane dishes were used to apply cyclic stretching to the transfected cells. 1 Hz cyclic stretching for 30 min in this system resulted in a significant stimulation of AP1 and SP1 mediated luciferase activity compared to unstimulated cells. In summary we describe a small-scale cell culture/bioreactor system capable of analyzing subcellular crosstalk mechanisms in mechanotransduction, mechanosensitivity of primary cells and of screening the activity of putative mechanosensitizers as new targets, e.g. for the treatment of bone loss caused by both disuse and signal transduction related alterations of mechanotransduction. KW - Bioreaktor KW - Mechanical strain KW - mechanosensitive reporter KW - gene constructs KW - bioreactor Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68099 ER - TY - JOUR A1 - Kaltdorf, Martin A1 - Breitenbach, Tim A1 - Karl, Stefan A1 - Fuchs, Maximilian A1 - Kessie, David Komla A1 - Psota, Eric A1 - Prelog, Martina A1 - Sarukhanyan, Edita A1 - Ebert, Regina A1 - Jakob, Franz A1 - Dandekar, Gudrun A1 - Naseem, Muhammad A1 - Liang, Chunguang A1 - Dandekar, Thomas T1 - Software JimenaE allows efficient dynamic simulations of Boolean networks, centrality and system state analysis JF - Scientific Reports N2 - The signal modelling framework JimenaE simulates dynamically Boolean networks. In contrast to SQUAD, there is systematic and not just heuristic calculation of all system states. These specific features are not present in CellNetAnalyzer and BoolNet. JimenaE is an expert extension of Jimena, with new optimized code, network conversion into different formats, rapid convergence both for system state calculation as well as for all three network centralities. It allows higher accuracy in determining network states and allows to dissect networks and identification of network control type and amount for each protein with high accuracy. Biological examples demonstrate this: (i) High plasticity of mesenchymal stromal cells for differentiation into chondrocytes, osteoblasts and adipocytes and differentiation-specific network control focusses on wnt-, TGF-beta and PPAR-gamma signaling. JimenaE allows to study individual proteins, removal or adding interactions (or autocrine loops) and accurately quantifies effects as well as number of system states. (ii) Dynamical modelling of cell–cell interactions of plant Arapidopsis thaliana against Pseudomonas syringae DC3000: We analyze for the first time the pathogen perspective and its interaction with the host. We next provide a detailed analysis on how plant hormonal regulation stimulates specific proteins and who and which protein has which type and amount of network control including a detailed heatmap of the A.thaliana response distinguishing between two states of the immune response. (iii) In an immune response network of dendritic cells confronted with Aspergillus fumigatus, JimenaE calculates now accurately the specific values for centralities and protein-specific network control including chemokine and pattern recognition receptors. KW - cellular signalling networks KW - computer modelling Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313303 VL - 13 ER - TY - JOUR A1 - Hoffmann, Annett A1 - Ebert, Thomas A1 - Hankir, Mohammed K. A1 - Flehmig, Gesine A1 - Klöting, Nora A1 - Jessnitzer, Beate A1 - Lössner, Ulrike A1 - Stumvoll, Michael A1 - Blüher, Matthias A1 - Fasshauer, Mathias A1 - Tönjes, Anke A1 - Miehle, Konstanze A1 - Kralisch, Susan T1 - Leptin improves parameters of brown adipose tissue thermogenesis in lipodystrophic mice JF - Nutrients N2 - Lipodystrophy syndromes (LD) are a heterogeneous group of very rare congenital or acquired disorders characterized by a generalized or partial lack of adipose tissue. They are strongly associated with severe metabolic dysfunction due to ectopic fat accumulation in the liver and other organs and the dysregulation of several key adipokines, including leptin. Treatment with leptin or its analogues is therefore sufficient to reverse some of the metabolic symptoms of LD in patients and in mouse models through distinct mechanisms. Brown adipose tissue (BAT) thermogenesis has emerged as an important regulator of systemic metabolism in rodents and in humans, but it is poorly understood how leptin impacts BAT in LD. Here, we show in transgenic C57Bl/6 mice overexpressing sterol regulatory element-binding protein 1c in adipose tissue (Tg (aP2-nSREBP1c)), an established model of congenital LD, that daily subcutaneous administration of 3 mg/kg leptin for 6 to 8 weeks increases body temperature without affecting food intake or body weight. This is associated with increased protein expression of the thermogenic molecule uncoupling protein 1 (UCP1) and the sympathetic nerve marker tyrosine hydroxylase (TH) in BAT. These findings suggest that leptin treatment in LD stimulates BAT thermogenesis through sympathetic nerves, which might contribute to some of its metabolic benefits by providing a healthy reservoir for excess circulating nutrients. KW - lipodystrophy KW - leptin KW - brown adipose tissue KW - thermogenesis KW - uncoupling protein 1 KW - sympathetic nervous system Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242787 SN - 2072-6643 VL - 13 IS - 8 ER -