Figure 3.

Role of miR-133 in the protective effect of tanshinone IIA against H₂O₂-induced H9c2 cell death. Cells with or without transfection with miR-133 mimic or inhibitor were incubated with 400 µM H₂O₂ in the presence or absence of tanshinone IIA (TIIA) for 24 h. Cell viability was determined using a Cell Counting Kit-8 assay. miR-133 mimic transfection protected against H₂O₂-induced cell death and miR-133 inhibitor transfection suppressed the protective effect of TIIA against H₂O₂-stimulated cell death. Data are presented as the mean ± standard deviation of three experiments. *P<0.05 vs. control; **P<0.05 vs. H₂O₂ only; ***P>0.05; ****P<0.05.