Effects of lentiviral-mediated p38 mitogen-activated protein kinase short hair-pin RNA on cardiac function after myocardial infarction in aldosterone overload rats / 中华老年医学杂志

ABSTRACT

Objective To investigate the effects of p38 mitogen-activated protein kinase (MAPK) short hair RNA (shRNA) delivered by lentiviral vectors (pGLV) on cardiac function after myocardial infarction (MI) in aldosterone overload rats and to explore the mechanism.Methods Aldosterone overload rat myocardial infarction model was obtained by ligating the left anterior descending coronary artery.The pGLV-shRNA was constructed,sequenced and injected into rats via tail vein.Rats were divided into 3 groupspGLV-shRNA group (n=6),pGLV-shRNA-NC group (n=6,contained a nonsense shRNA) and the sham-operation group (n=6).Cardiac function was measured by cardiac ultrasound.Apoptosis was assessed by transferase (TdT)-mediated biotin-16-dUTP nick-end labelling (TUNEL).The p38 MAPK mRNA expression was analyzed by RT-PCR.The protein expressions of p38 MAPK and caspase-3 were detected by Western blot.Results Compared with the sham-operation group,cardiac systolic function was reduced and myocardial apoptosis index was significantly increased [(31.26 ± 4.45) ％ vs.(15.20 ± 2.18) ％,P ＜ 0.01] in pGLV-shRNA-NC group.The mRNA and protien expressions of p38MAPK and caspase 3 protein expression were significantly increased in pGLV-shRNA-NC group (all P＜0.01).Compared with pGLV-shRNA-NC group,cardiac function was improved,myocardial cell apoptosis index was reduced [(22.35±3.59)％ vs.(31.26±4.45)％,P＜0.05],and the mRNA and protien expressions of p38MAPK and caspase 3 protein expression were decreased in pGLV-shRNA group (all P＜0.05).Conclusions Cardiac dysfunction is associated with p38MAPK-mediated myocardial apoptosis in aldosterone overload MI rats.pGLV-shRNA may inhibit cardiomyocyte apoptosis and improve postMI cardiac function.