Fig. 4

FOXO1 was a direct target of miR-142-3p. a Predicted binding sites between miR-142-3p and the FOXO1 3′-UTR. b Dual-luciferase assay was performed in cardiomyocytes after co-transfection with FOXO1 3′-UTR WT or mutant (MUT) plasmids, and miR-142-3p mimics. *P < 0.05 vs. control in the WT group. c, d Western blot analysis of FOXO1 and β-actin protein levels in cardiomyocytes transfected with mimic control or miR-142-3p mimic treated with the exosome^MIF, and subjected to H₂O₂. Cardiomyocytes with or without exosome^MIF were subjected to H₂O₂. Untreated cardiomyocytes were used as a control. *P < 0.05 vs. control; ^▲P < 0.05 vs. H₂O₂; ^○P < 0.05 vs. H₂O₂+exosome^MIF miR-142-3p mimic. e–g Cardiomyocytes were transfected with siRNA-FOXO1 or siRNA-NT. Untreated cardiomyocytes were used as a control. siRNA-mediated transfection efficiency was determined by qRT-PCR (e) and western blotting (f, g). Each column represents mean ± SD from three independent experiments. *P < 0.05 vs. siRNA-FOXO1