Figure 3

The effect of STIM1 silencing on rat PASMC proliferation and cell cycle progression under hypoxia. (A). Western blot showing STIM1 and β-actin protein expression from untreated control PASMCs (Control) and PASMCs treated with transfection-nontargeted siRNA (siNT) or siRNA targeted to STIM1 (siSTIM1). (B). Mean ratios of STIM1 protein expression relative to that of β-actin, as measured by Western blotting in Control, siNT, and siSTIM1 PASMCs. *: P < 0.05 compared to the Control group and the siNT group. The results are expressed as the mean ± SEM of four experiments. (C)After transfection with STIM1 siRNA, PASMCs were cultured in hypoxic conditions for 24 hours. [3H]-thymidine (3H-TdR) incorporation was measured to detect PASMC proliferation. (D) PASMCs were harvested for flow cytometry-based cell cycle analysis. PASMCs were either left untreated under normoxic conditions (N), left untreated under hypoxic conditions (HCON), treated with nontargeted siRNA under hypoxic conditions (HsiNT), or treated with siRNA targeted to STIM1 under hypoxic conditions (HsiSTIM1). *:P < 0.05 compared with the Control group and #:P < 0.05 compared with the HCON and HsiNT group. The results are expressed as the mean ± SEM of three experiments.