Figure 6.

NOX4 mediates proliferative activity by HIF-1α and hypoxia. Pulmonary artery smooth-muscle cells (PASMCs) were transfected with vectors encoding different shRNAs against NOX4 (siN4I, siN4II) or control shRNA (siCtr) and were either cotransfected with a plasmid coding for HIF-1α or were exposed to hypoxia for 4 h. Proliferative activity was determined by (A) BrdU incorporation or (B) determination of cell numbers using a hemocytometer. Data are shown as relative change to normoxic control (100%; n = 3, *p < 0.05 vs. control; ^#p < 0.05 vs. HIF-1α–transfected or hypoxia-stimulated control). (C) Western blot analysis was performed with antibodies against HIF-1α, NOX4, or ARNT. Actin served as loading control.