Figure 5. Overexpression of HSF1 participates in mitochondrial apoptosis by regulating Omi/HtrA2 expression in H9C2 cells. HSF1 expression increased after transfection of plasmid pcDNA3.1, which was not affected by RNAi Omi/HtrA2 (A, B). Omi/HtrA2 protein expression increased after transfection of plasmid pcDNA3.1, which decreased after RNAi Omi/HtrA2 (A, C). Caspase -9 activity was induced by HSF1 overexpression, which was reversed after transient transfection of si-Omi/HtrA2 (D). Caspase-3 activity was suppressed by HSF1 overexpression, but similar change was detected after RNAi using Omi/HtrA2 (E). Data are represented as mean +/- SEM. *P<0.05, **P<0.01 vs. pcDNA3.1, #P<0.05, ##P<0.01 vs. HSF1+scramble, n = 4.