Figure 7.

Role of Src kinase and PP2A phosphorylation in Nox4-dependent Akt activation in cardiac cells. (A and B) Protein levels of phospho (Tyr³⁰⁷)-protein phosphatase 2A catalytic subunit (p-PP2Ac), total PP2Ac (A), phospho (Tyr⁴¹⁶)-Src (p-Src), and total Src (B) assessed by western blotting in lysates from H9C2 cells. Nox4 knockdown or overexpression was performed as in Figure 6 (n = 3 independent experiments); **P < 0.01 using unpaired Student’s t-test. (C) Cells were transduced with Nox4 (+Nox4) or β-Gal (-Nox4) containing adenoviruses for 48 h followed by incubation with the Src inhibitor SU6656 (+SU6656; 1 µM) or DMSO (-SU6656) for 3 h. Protein levels were quantified by densitometry (n = 3 independent experiments). ^‡P < 0.05, ^#P < 0.01 vs. respective control (-Nox4, -SU6656), **P < 0.01 as indicated using one-way ANOVA followed by Bonferroni post-hoc test for multiple comparisons.