Fig. 5

MiR-320-3p acts by targeting HSP20. A-B HSP20 is downregulated in cardiac hypertrophy. A The expression of HSP20 in cardiomyocytes treated with 10 μM ISO was analyzed by immunoblotting. n = 3. B The expression of HSP20 in the myocardial tissue of the ISO-induced mouse cardiac hypertrophy model was analyzed by immunoblotting. n = 6. C Silencing of HSP20 aggravates ISO-induced cardiomyocyte hypertrophy. Cardiomyocytes were transfected with HSP20 siRNA or its scramble control (si-NC) and then exposed to 10 μM ISO for 48 h. Cardiomyocyte hypertrophy was assessed by cell surface area measurement, *P < 0.05, **P < 0.01. n = 3. D–E The expression of HSP20 in cardiomyocytes was decreased by miR-320-3p. D Cardiomyocytes were transfected with miR-320-3p inhibitor or negative control inhibitor (Inhibitor-NC) and then treated with 10 μM ISO for 24 h. E Cardiomyocytes were transfected with miR-320-3p mimic or control mimic. The expression of HSP20 was analyzed by immunoblotting. F The antihypertrophic effect of the miR-320-3p inhibitor is abolished by HSP20-siRNA. Cardiomyocytes were co-transfected with miR-320-3p inhibitor and HSP20-siRNA and then exposed to 10 μM ISO for 48 h. Cardiomyocyte hypertrophy was assessed by cell surface area measurement. **P < 0.01. n = 3