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.