Fig. 5

Shape signals control maturation of vascular smooth muscle cells. a Representative images of SMCs plated on ellipsoid micropatterns and stained either for (left) α-SMA (green) and F-actin (red), or (right) calponin (green) and F-actin (red). In untreated SMCs, both α-SMA and calponin showed increased expression with increasing aspect ratio that was colocalized with actin stress fibers, which is a hallmark of contractile SMC maturation. When integrin β₃ activation was blocked, this phenotypic feature was abolished. Treated cells with β₁ blocking antibodies had no effect on the shape-driven phenotype even though the cells failed to comply with the ellipsoid micropatterns. b Quantitative analysis of α-SMA and calponin in SMCs plated on ellipsoid patterns with or without integrin β₁ or β₃ blocking antibodies. Values are given as mean ± SEM; n = 80, chosen randomly from eight different slides cultured independently (^p < 0.05, *p < 0.01 vs. previous ratio; one-way ANOVA comparisons independent for each condition). c SMCs were treated with varying concentrations of blebbistatin from 0.1 to 100 μM for 12 h before fixation and stained for F-actin (red) and α-SMA (green). Both stress fiber integrity and compliance of the cells with the micropatterns decrease with increasing blebbistatin concentration; however, α-SMA expression shows little change with the increasing blebbistatin concentration