Figure 3.

Nox4 contributes to stretch- and hypoxia-induced expression of VEGF

A, Nox4 and Hif1α protein expression analysed by western blotting. B and C, quantitative PCR analysis for VEGF mRNA expression. After 3 days of differentiation from myoblasts to myotubes, C2C12 cells were treated with or without DPI (1 μm), catalase (500 U ml^–1) or H₂O₂ (400 μm) for 8 h in 2% O₂ hypoxia (B) or subjected to cyclic stretch with the Flexcell system for 1 h (C). Mean ± SEM (n > 3) *P < 0.05. VEGF expression in satellite cells isolated from skeletal muscle of wild-type (WT) or Nox4^−/− mice with or without 2% O₂ hypoxia (D) or 1 h cyclic stretch with the Flexcell system (E). Mean ± SEM (n > 5 with each n = cells from one mouse) *P < 0.05 (ctl vs. Ex.); &P < 0.05 (WT vs. Nox4^−/−). Ctl, control; Ex., exercised.