The expression of VEGF-A protein and PPARγ dependent pathway. A. PC-14 cells were treated with 0, 10, 50, or 100 μM troglitazone or ciglitazone and 48 h after treatment the expression of VEGF-A protein was measured by western blot analysis. B. PC-14 cells were treated with or without GW9662 (20 μM), a PPARγ inhibitor, for 1 h before they were exposed to troglitazone or ciglitazone (50 μM each). After 24 h of thiazolidinedione treatment, the relative expression of VEGF-A mRNA was evaluated using real-time PCR. Data are expressed as mean (SD) (n = 3). ***P < 0.001 vs. vehicle control.