KCNK3 antagonist inhibits BMP-induced switching of HPASMC phenotypes. (A, B) Treatment with a KCNK3 antagonist, A293, blocked the anti-proliferative effect of BMPs on HPASMCs. Cells were cultured in growth medium containing BMPs (100 ng/ml) or A293 (200 nM) for 72 h and then stained with anti-Ki67 IgG. (A) Representative images of Ki67 (red) staining and (B) Quantitative analysis of the percentage of Ki67+ cells in HPASMCs (n = 6). (C, D) Treatment with a KCNK3 antagonist, A293, blocked the BMP-induced the expression of SMC differentiation marker genes in HPASMCs. SiRNA-transfected and non-transfected cells were cultured in growth media with or without BMPs (30 ng/ml) for 48 h and then stained with anti-α-SMA IgG (red). The percentages of α-SMA+ cells were assessed (n = 4). Nuclei in (A) and (C) are shown in blue (DAPI). Scale bars = 50 μm. Data are presented as mean ± SEM (*P < 0.05, **P < 0.01, ***P < 0.001).