Fig 2: Effect of dobutamine treatment on protein expression of caspase-3 and caspase-9 in MG-63 cells. (A) Western blot analysis and (B) quantification of protein expression of caspase-3 and caspase-9. Cells were treated with various concentrations of dobutamine (0, 1, 10 and 50 µM) for 72 h. GAPDH was used as an internal control gene. The expression level was calculated as the ratio of caspase-3 or caspase-9:GAPDH. Data are presented as the mean ± standard deviation (n=6). *P<0.05 compared with the control group. GAPDH, glyceraldehyde-3-phosphate dehydrogenase.

Fig 3: Effect of EP on expression levels of apoptosis-related proteins. (A) Western blots of caspase-3, Bcl-2 and Bax from myocardial tissue and the quantified expression levels of (B) caspase-3, (C) Bcl-2 and (D) Bax. #P<0.05 vs. control and EP groups, *P<0.05 vs. ADR group. &P<0.01 vs. ADR group. EP, ethyl pyruvate; ADR, Adriamycin.

Fig 4: Expression of apoptotic proteins and autophagy-related proteins in H9c2 cells under H/R conditions, in H9c2 cells transfected with miR-103a-3p mimics and/or miR-103a-3p inhibitors. (A) Protein expression levels of Bax, Bcl-2, cleaved caspase-3 and cleaved caspase-9 were determined by western blotting. (B) Quantitative evaluation of the protein expression levels. NC, untreated H9c2 cells; H/R, H9c2 cells under H/R; mimic-Control, H9c2 cells transfected with miRNA mimic control; miR-103a-3p mimics + H/R, H9c2 cells transfected with miR-103a-3p mimic and then H/R; miR-103a-3p inhibitor, H9c2 cells transfected with miRNA inhibitor; inhibitor-Control, H9c2 cells transfected with miRNA inhibitor control. All data are expressed as the mean ± standard deviation. *P<0.05, **P<0.01 and ***P<0.001, vs. NC; ###P<0.001, vs. H/R. miR, microRNA; NC, negative control; H/R, hypoxia/reoxygenation; Bcl-2, B-cell lymphoma 2; Bax, Bcl-2-associated X protein.