To laminar shear stress (12 dynes/cm2 ) for 24 h decreased the cell proliferation and migration activity [85] in comparison to the static cultures. A decreased proliferation was also observed in bovine aortic SMCs seeded on glass slides collagen Icoated and exposed to laminar shear anxiety (11 dynes/cm2 ) for 24 h [86]. Unfortunately, there was no details about the SMC marker genes before and following the shear strain in all these research. General, the physiological relevance in the in vitro responses of SMCs to laminar shear pressure is unclear. The patterns of shear pressure at sites of endothelial cell injury in vivo don’t necessarily mirror the continuous laminar shear stress addressed by a number of studies. Disturbed or turbulent shear tension patterns happen to be shown to induce atherosclerotic plaque formation in vivo and activate inflammatory signaling on endothelial cells in vitro [87]. Even so, the in vitro effects of disturbed or turbulent shear stress on the SMC phenotype have not been wellcharacterized. Pioneer studies have shown that bovine aortic SMC elevated their DNA synthesis and proliferation capacity when exposed to oscillatory shear strain (14 dynes/cm2 ) for 3 or five days when compared with the static controls [88], but the degree to which this was accompanied by modifications in the SMC phenotypic markers was not analyzed. A far more systematic characterization with the phenotype and function of SMCs exposed to a higher array of shear strain forces and patterns on relevant substrates are additional necessary, Table five.Cells 2021, 10,13 ofTable 5. Representative overview in the current in vitro 2D research that investigated the impact of shear pressure on human, rat, and bovine SMC phenotypes. Increased and decreased .Study Shear Anxiety Kind, Intensity, and Duration Material and Matrix Substrate SMC Source Approach Applied Effects on SM Phenotype Acta2 Tagln Myh11 Smtn Cnn[80]Laminar: 8 dynes/cm2 for 15 hPlastic/fibronectinSprague awley rat thoracic aortaRotating disk[81]Laminar: 12 dynes/cm2 for 24 h Laminar: 14 dynes/cm2 for 24 hGlass/fibronectinHuman aortaParallel plate flow chamber Parallel plate flow chamberproliferation inflammationMyh11 Smtn Acta[82]Not statedRat aortic[83]Laminar: 15 dynes/cm2 for six, 12 and 24 h Laminar: 14 dynes/cm2 for 24 h Laminar: 12 dynes/cm2 for 24 h Laminar: 11 dynes/cm2 for 24 h Oscillatory: 14 dynes/cm2 for three and 5 daysPlastic/ Pyridaben References coating not stated Plastic/ coating not stated Glass/ coating not stated Glass/ Collagen I Plastic/Collagen IRat Brain arteriesParallel plate flow chamber Parallel plate flow chamber Parallel plate flow chamber Parallel plate flow chamber Orbital shakerproliferation migration Acta2 Tagln proliferation proliferation migration proliferation proliferation[84] [85] [86] [88]Sprague awley Rat aortic Sprague awley rat thoracic aorta Bovine aortic Bovine aortic6. Smooth Muscle Cell Mechanotransduction The cellular procedure of converting mechanical cues into biochemical signals is called cellular mechanotransduction. This aspect has been reviewed extensively in other vascular cells [89]. Having said that, the precise mechanisms of cellular mechanotransduction on SMCs upon stretching are nonetheless not totally clear. Normally terms, external mechanical forces could be transmitted to a cell in various strategies, mainly by activating the integrin signaling pathway but in addition by G proteincoupled receptors (GPCRs), by nonselective cation channels, or by the coordinated and synergistic interactions of some or.
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