BAX activation and cytochrome c release in NRK-52E cells are reduced by overexpression of HSPB1 after H₂O₂ treatment.

<p>(A, B) Determination of active BAX content assessed with a conformation-specific antibody directed against the 6A7 epitope, total BAX content, and cytochrome c of cytosol fractions in control NRK-52E cells and NRK-52E cells transfected with pcDNA or the HSPB1 overexpression vector and treated with 400 and 600 μM H₂O₂ for 4 h. (C, D) Quantitative analysis with a densitometer showed a marked reduction in BAX activation when cells were transfected with the HSPB1 expression vector. Data are presented as means ± SEM, n = 6; *P < 0.05. (E, F) NRK-52E cells were transfected with control scrambled siRNA or HSPB1 siRNA, and the active BAX, total BAX, and cytochrome c of cytosol fractions were examined in control cells and cells exposed to 400 and 600 μM H₂O₂ for 4 h. (G, H) Quantitative analysis with a densitometer demonstrated that HSPB1 regulated BAX activation in NRK-52E cells. Data are presented as means ± SEM, n = 6; *P < 0.05 vs. control.