Pioglitazone induced apoptosis of VSMCs. A. Pioglitazone-treated VSMCs are inclined to apoptosis. Cultured VSMCs were transfected with vector, wt-PPARγ, or siRNA-PPARγ, respectively. Cells (non-transdued or transduced) were then treated with different drugs as indicated. VSMCs from distinct groups were then harvested and subjected to Annexin V staining. The representative staining plots (A) and the frequency of apoptotic cells from three independent experiments (B) was shown. The numbers indicate the frequency of the Annexin V+/PI- cell population. Values are presented as the mean ± SEM, n = 3. **P < 0.001, *P < 0.01.