抄録
It has been reported that vascular smooth muscle cells (VSMCs) change their phenotype from contractile to synthetic type when they are cultured in low concentration of elastin solution or on stiff substrate. Since these environmental and phenotypic changes are found in aneurysm walls, low traction force generated by synthetic type cells may decrease contraction of the walls, thus causes their dilation. We examined the effects of both elastin concentration and substrate stiffness on cell traction force. VSMCs were cultured in DMEM supplemented with (Ela(+)) or without 100 μg/ml soluble elastin (Ela(-)) and seeded on polyacrylamide gels with Young's modulus of 2 to 265 kPa. After 72 h, VSMCs on stiffer gels proliferated faster like synthetic type. Intensities of labeled contractile marker proteins such as α-smooth muscle actin and calponin were significantly higher in Ela(+) than Ela(-). Interestingly, traction force increased and decreased in Ela(-) and Ela(+), respectively, with the increase in gel stiffness. These results indicate that both elastin concentration and substrate stiffness affect phenotype and cell traction force in a complex way.
