@article{ScholzGehringGuanetal.2015, author = {Scholz, Nicole and Gehring, Jennifer and Guan, Chonglin and Ljaschenko, Dmitrij and Fischer, Robin and Lakshmanan, Vetrivel and Kittel, Robert J. and Langenhan, Tobias}, title = {The adhesion GPCR Latrophilin/CIRL shapes mechanosensation}, series = {Cell Reports}, volume = {11}, journal = {Cell Reports}, doi = {10.1016/j.celrep.2015.04.008}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148626}, pages = {866-874}, year = {2015}, abstract = {G-protein-coupled receptors (GPCRs) are typically regarded as chemosensors that control cellular states in response to soluble extracellular cues. However, the modality of stimuli recognized through adhesion GPCR (aGPCR), the second largest class of the GPCR superfamily, is unresolved. Our study characterizes the Drosophila aGPCR Latrophilin/dCirl, a prototype member of this enigmatic receptor class. We show that dCirl shapes the perception of tactile, proprioceptive, and auditory stimuli through chordotonal neurons, the principal mechanosensors of Drosophila. dCirl sensitizes these neurons for the detection of mechanical stimulation by amplifying their input-output function. Our results indicate that aGPCR may generally process and modulate the perception of mechanical signals, linking these important stimuli to the sensory canon of the GPCR superfamily.}, language = {en} } @article{PereiraLipphausErginetal.2021, author = {Pereira, Ana Rita and Lipphaus, Andreas and Ergin, Mert and Salehi, Sahar and Gehweiler, Dominic and Rudert, Maximilian and Hansmann, Jan and Herrmann, Marietta}, title = {Modeling of the Human Bone Environment: Mechanical Stimuli Guide Mesenchymal Stem Cell-Extracellular Matrix Interactions}, series = {Materials}, volume = {14}, journal = {Materials}, number = {16}, issn = {1996-1944}, doi = {10.3390/ma14164431}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245012}, year = {2021}, abstract = {In bone tissue engineering, the design of in vitro models able to recreate both the chemical composition, the structural architecture, and the overall mechanical environment of the native tissue is still often neglected. In this study, we apply a bioreactor system where human bone-marrow hMSCs are seeded in human femoral head-derived decellularized bone scaffolds and subjected to dynamic culture, i.e., shear stress induced by continuous cell culture medium perfusion at 1.7 mL/min flow rate and compressive stress by 10\% uniaxial load at 1 Hz for 1 h per day. In silico modeling revealed that continuous medium flow generates a mean shear stress of 8.5 mPa sensed by hMSCs seeded on 3D bone scaffolds. Experimentally, both dynamic conditions improved cell repopulation within the scaffold and boosted ECM production compared with static controls. Early response of hMSCs to mechanical stimuli comprises evident cell shape changes and stronger integrin-mediated adhesion to the matrix. Stress-induced Col6 and SPP1 gene expression suggests an early hMSC commitment towards osteogenic lineage independent of Runx2 signaling. This study provides a foundation for exploring the early effects of external mechanical stimuli on hMSC behavior in a biologically meaningful in vitro environment, opening new opportunities to study bone development, remodeling, and pathologies.}, language = {en} } @article{KarakayaBiderFranketal.2022, author = {Karakaya, Emine and Bider, Faina and Frank, Andreas and Teßmar, J{\"o}rg and Sch{\"o}bel, Lisa and Forster, Leonard and Schr{\"u}fer, Stefan and Schmidt, Hans-Werner and Schubert, Dirk Wolfram and Blaeser, Andreas and Boccaccini, Aldo R. and Detsch, Rainer}, title = {Targeted printing of cells: evaluation of ADA-PEG bioinks for drop on demand approaches}, series = {Gels}, volume = {8}, journal = {Gels}, number = {4}, issn = {2310-2861}, doi = {10.3390/gels8040206}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267317}, year = {2022}, abstract = {A novel approach, in the context of bioprinting, is the targeted printing of a defined number of cells at desired positions in predefined locations, which thereby opens up new perspectives for life science engineering. One major challenge in this application is to realize the targeted printing of cells onto a gel substrate with high cell survival rates in advanced bioinks. For this purpose, different alginate-dialdehyde—polyethylene glycol (ADA-PEG) inks with different PEG modifications and chain lengths (1-8 kDa) were characterized to evaluate their application as bioinks for drop on demand (DoD) printing. The biochemical properties of the inks, printing process, NIH/3T3 fibroblast cell distribution within a droplet and shear forces during printing were analyzed. Finally, different hydrogels were evaluated as a printing substrate. By analysing different PEG chain lengths with covalently crosslinked and non-crosslinked ADA-PEG inks, it was shown that the influence of Schiff's bases on the viscosity of the corresponding materials is very low. Furthermore, it was shown that longer polymer chains resulted in less stable hydrogels, leading to fast degradation rates. Several bioinks highly exhibit biocompatibility, while the calculated nozzle shear stress increased from approx. 1.3 and 2.3 kPa. Moreover, we determined the number of cells for printed droplets depending on the initial cell concentration, which is crucially needed for targeted cell printing approaches.}, language = {en} } @article{JarauschNeuenrothAndagetal.2022, author = {Jarausch, Johannes and Neuenroth, Lisa and Andag, Reiner and Leha, Andreas and Fischer, Andreas and Asif, Abdul R. and Lenz, Christof and Eidizadeh, Abass}, title = {Influence of shear stress, inflammation and BRD4 inhibition on human endothelial cells: a holistic proteomic approach}, series = {Cells}, volume = {11}, journal = {Cells}, number = {19}, issn = {2073-4409}, doi = {10.3390/cells11193086}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289872}, year = {2022}, abstract = {Atherosclerosis is an important risk factor in the development of cardiovascular diseases. In addition to increased plasma lipid concentrations, irregular/oscillatory shear stress and inflammatory processes trigger atherosclerosis. Inhibitors of the transcription modulatory bromo- and extra-terminal domain (BET) protein family (BETi) could offer a possible therapeutic approach due to their epigenetic mechanism and anti-inflammatory properties. In this study, the influence of laminar shear stress, inflammation and BETi treatment on human endothelial cells was investigated using global protein expression profiling by ion mobility separation-enhanced data independent acquisition mass spectrometry (IMS-DIA-MS). For this purpose, primary human umbilical cord derived vascular endothelial cells were treated with TNFα to mimic inflammation and exposed to laminar shear stress in the presence or absence of the BRD4 inhibitor JQ1. IMS-DIA-MS detected over 4037 proteins expressed in endothelial cells. Inflammation, shear stress and BETi led to pronounced changes in protein expression patterns with JQ1 having the greatest effect. To our knowledge, this is the first proteomics study on primary endothelial cells, which provides an extensive database for the effects of shear stress, inflammation and BETi on the endothelial proteome.}, language = {en} }