Fig. 4. Effects of miR-1 and miR-133 on caspase 3 (Casp3) protein levels and activities in H9c2 cells. (A) Immunoblotting analysis of Casp3 protein levels with and without miR-1 or miR-133 treatment. The antibody against the total Casp3 recognized the 35 kDa band representing Casp3. AP+: antibody pretreated with its antigenic peptide; Ctl: cells treated with Lipofectamine 2000 only; miR-1 and miR-133: cells transfected with miR-1 and miR-133, respectively and with Lipofectamine 2000. n=8 experiments for each group. (B) Regulation of Casp3 activity by miR-1 and miR-133. Transfection was performed with Lipofectamine 2000 and measurements were made 24 hours after transfection. ^*P<0.05 vs Ctl; ⁺P<0.05 vs miR-1 alone or miR-133 alone or H₂O₂ alone; n=5 for each group.