Effects of silencing of NHE1 on cell-cycle progression of human PASMCs. After transfection with NHE1 siRNA, PASMCs were cultured in normoxia or hypoxia for 24 hours, and harvested for cell-cycle analysis by flow cytometry. (A) Quantitative data on cell-cycle progression. (B) Representative depictions of flow cytometry. *P < 0.05, compared with the control group (n = 3 for each group). NC, normoxia control; N + siRNA, normoxia + NHE1 siRNA; HC, hypoxia control; H + siRNA, hypoxia + NHE1 siRNA.