Effect of ROCK signalling inhibition on
γ-actin knockdown-induced vascular regression. (A) Graph showing the percentage of wound recovery as a function of time for control (black) and γ-actin knockdown (red) HMEC-1 cells, either untreated (left) or treated with ROCK inhibitors, H-1152 (middle) or Y-27632 (right) at 1 and 10 μM, respectively. Points, means of at least four individual experiments; bars, SE. (B) Representative photographs of HMEC-1 cells incubated for 8 h on MatrigelTM. Cells were transfected with either control (top) or γ-actin siRNA (bottom) for 72 h and either untreated (left) or treated with ROCK inhibitors, H-1152 (middle) or Y-27632 (right) at 1 and 10 μM, respectively. Inset, % of angiogenesis inhibition as compared to untreated control cells. Scale bar, 250 μm. (C-D) Histograms showing the surface occupied by and the number of vascular networks formed by control and γ-actin siRNA-transfected HMEC-1 cells following treatment with ROCK inhibitors. Columns, means of at least four individual experiments; bars, SE. Statistics were calculated by comparing the mean surface occupied by vascular networks and the mean number of vascular networks per view field (at least 10 view fields per condition) for control siRNA- versus γ-actin siRNA-transfected cells unless indicated otherwise. *, p < 0.05; **, p < 0.01; ***, p < 0.001.