Figure 9.

YAP1 regulates S1P-mediated proliferation in hPASMCs. (A) Representative images and (B) quantitative data from TUNEL assays. hPASMCs were cultured on a coverslip in a six-well cell culture plate. H₂O₂ (100 µM) was used as an apoptosis stimulus for hPASMCs. When cell confluence reached ~95%, cells were starved for 3 h, pre-treated with verteporfin (200 nM, 1 h)) and challenged with H₂O₂ or S1P (1 µM) for 24 h. Cell apoptosis was examined using an in situ BrdU–Red DNA fragmentation (TUNEL) kit. Representative images from each group are demonstrated. Scalebar: 20 µm. ** p < 0.01; *** p < 0.001. hPASMC cell proliferation was examined with BrdU assays; FBS (10%) was used as a positive control. (C) Silencing YAP1 with YAP1 siRNA (50 nM, 72 h) attenuated S1P-mediated hPASMC proliferation. (D) YAP1 inhibition with verteporfin (200 nM) attenuated S1P-mediated hPASMC proliferation in a dose-dependent manner. * p < 0.05; ** p < 0.01; *** p < 0.001. n = 3. Scale bar: 50 μm.