The effect of Bach1 on the regulation of HO-1 expression in Hcy-treated HepG2 cells. Cells were treated with 100 pmol Bach1siRNA or control siRNA for 72 h before Hcy treatment (0, 100, 500, 1000 μM for 24 h). (A) Protein level of Bach1 was analyzed using Western blotting. β-actin was used as a internal control. Representative image of three independent experiments was shown. (B) HO-1 mRNA levels were detected by qRT-PCR. Each data point represents means ± SEM from three independent experiments. Values for cells treated with control siRNA-only were set equal to 1. The two curves are significantly different from one another using nonlinear regression analysis (P < 0.001) and the data points are significantly different from one another. *P < 0.05 vs. cells treated with control siRNA-only.