FIGURE 4.
Rapamycin treatment inhibits RhoA activation by VEGF in a p27Kip1-dependent manner. A, HCAECs were starved for 72 h and then serum-stimulated in the presence of the indicated dose of rapamycin for 24 h. HCAECs were then stimulated with 10 ng/ml of VEGF for 5 min, and RhoA activation was measured. Error bars represent mean ± S.E. (n = 3) normalized to the unstimulated control (CON). B, HCAECs were serum-stimulated for 24 h in the presence of nontargeting siRNA or siRNA targeting p27Kip1. The medium was then supplemented with either rapamycin (VEGF + RPM; 100 nmol/liter) or vehicle (CON and VEGF), and the cells were incubated for an additional 24 h. RhoA activity was then stimulated for 5 min with VEGF (VEGF and VEGF + RPM; 10 ng/ml). Error bars represent mean ± S.E. (n = 3). Brackets indicate p < 0.05.