Fig. 4

MiR-320-3p promotes ISO-induced cardiomyocyte hypertrophy. A, B No change in miR-320-3p levels in cardiac hypertrophy. A Cardiomyocytes were treated with 10 μΜ ISO. The expression level of miR-320-3p was analyzed by qPCR. n = 3. B The expression level of miR-320-3p in rat hypertrophic cardiac tissue was analyzed by qPCR. n = 3. C The expression level of miR-320-3p in cardiomyocytes transfected with miR-320-3p inhibitor or negative control inhibitor (inhibitor-NC) was analyzed by qPCR. **P < 0.01. n = 3. D-H Knockdown of miR-320-3p inhibits cardiomyocyte hypertrophy. Cardiomyocytes were transfected with miR-320-3p inhibitor or negative control inhibitor. Forty-eight hours after ISO treatment, cardiomyocyte hypertrophy was assessed by D sarcomere organization (bar = 20 μm), E cell surface area measurement and level of F ANP, G BNP and H β-MHC. The expression level of ANP, BNP and β-MHC was analyzed by qPCR. *P < 0.05, **P < 0.01. n = 3. I The expression level of miR-320-3p in cardiomyocytes transfected with miR-320-3p mimic or negative control mimic (mimic-NC) was analyzed by qPCR. **P < 0.01. n = 3. J–M MiR-320-3p aggravates ISO-induced cardiomyocyte hypertrophy. Cardiomyocytes were transfected with miR-320-3p mimic or control mimic. Forty-eight hours after ISO treatment, cardiomyocyte hypertrophy was assessed by J cell surface area measurement and level of K ANP, L BNP and M β-MHC. The expression level of ANP, BNP and β-MHC was analyzed by qPCR. *P < 0.05, **P < 0.01. n = 3