title: Remanent cell traction force in renal vascular smooth muscle cells induced by integrin-mediated mechanotransduction.
abstract: It was previously demonstrated in isolated renal vascular smooth muscle cells (VSMCs) that integrin-mediated mechanotransduction triggers intracellular Ca(2+) mobilization, which is the hallmark of myogenic response in VSMCs. To test directly whether integrin-mediated mechanotransduction results in the myogenic response-like behavior in renal VSMCs, cell traction force microscopy was used to monitor cell traction force when the cells were pulled with fibronectin-coated or low density lipoprotein (LDL)-coated paramagnetic beads. LDL-coated beads were used as a control for nonintegrin-mediated mechanotransduction. Pulling with LDL-coated beads increased the cell traction force by 61 ± 12% (9 cells), which returned to the prepull level after the pulling process was terminated. Pulling with noncoated beads had a minimal increase in the cell traction force (12 ± 9%, 8 cells). Pulling with fibronectin-coated beads increased the cell traction force by 56 ± 20% (7 cells). However, the cell traction force was still elevated by 23 ± 14% after the pulling process was terminated. This behavior is analogous to the changes of vascular resistance in pressure-induced myogenic response, in which vascular resistance remains elevated after myogenic constriction. Fibronectin is a native ligand for α(5)β(1)-integrins in VSMCs. Similar remanent cell traction force was found when cells were pulled with beads coated with β(1)-integrin antibody (Ha2/5). Activation of β(1)-integrin with soluble antibody also triggered variations of cell traction force and Ca(2+) mobilization, which were abolished by the Src inhibitor. In conclusion, mechanical force transduced by α(5)β(1)-integrins triggered a myogenic response-like behavior in isolated renal VSMCs.
authors: Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
authors: Lavanya
authors: L
authors: Balasubramanian
authors: Chun-Min
authors: CM
authors: Lo
authors: James S K
authors: JS
authors: Sham
authors: Kay-Pong
authors: KP
authors: Yip
mesh_terms: D000818:Animals; D020013:Calcium Signaling; D002448:Cell Adhesion; D002478:Cells, Cultured; D039482:Integrin alpha5 / Q000378:metabolism / Q000502:physiology*; D019012:Integrin beta1 / Q000378:metabolism / Q000502:physiology*; D008297:Male; D040542:Mechanotransduction, Cellular; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012077:Renal Artery / Q000166:cytology*; D033081:Shear Strength; D014661:Vasoconstriction
chemical_list: D039482:Integrin alpha5; D019012:Integrin beta1