单硝酸异山梨酯上调外泌体-microRNA378表达减轻机械牵张诱导的心力衰竭

Isosorbide mononitrate inhibits mechanical stress-induced heart failure through upregulating expression of exosomal-microRNA378

关键词:  单硝酸异山梨酯  外泌体-microRNA378  机械牵张  心力衰竭

Key words:  isosorbide mononitrate  exosomal-microRNA378  mechanical stress  heart failure

摘要:

目的 探讨单硝酸异山梨酯（isosorbide mononitrate, ISMN）对机械牵张诱导的心力衰竭的作用及与外泌体-microRNA378的关系。方法 对C57BL/6小鼠施行升主动脉缩窄术(transverse aortic constriction, TAC)4周后建立在体压力超负荷诱导心力衰竭模型，对培养的心肌细胞机械牵张48h后构成离体压力超负荷诱导心力衰竭模型。在体实验分为3组： 对照组、升主动脉缩窄组（TAC组）、升主动脉缩窄+单硝酸异山梨酯组（TAC+ISMN组）。离体实验分为5组： 对照组、牵张组、牵张+microRNA378类似物组、牵张+ISMN组、牵张+ISMN+microRNA378抑制剂组。4周后进行心超检查，测定心质量/体质量、心肌细胞形态、血浆NT-proBNP,外泌体-microRNA378表达。机械牵张48h后，收集细胞提取RNA，RT-qPCR检测ANP、SAA的表达。结果 TAC+ISMN组较TAC组左心室舒张末期内径、左心室舒张末期前壁厚度、心质量/体质量、NT-proBNP水平明显下降(P<0.01、P<0.05、P<0.01、P<0.01)，短轴缩短率明显升高（P<0.05）。RT-qPCR显示TAC+ISMN组较TAC组外泌体-microRNA378表达明显上调（P<0.05）。牵张+ISMN组、牵张+microRNA378类似物组较牵张组ANP、SAA表达下降（P<0.05），牵张+ISMN+microRNA378抑制剂组较牵张组ANP、SAA表达下降不明显（P>0.05）。 结论 ISMN通过上调外泌体-microRNA378的表达减轻机械牵张诱导的心力衰竭。

Abstract:

Objective To investigate the effects of isosorbide mononitrate (ISMN) on mechanical stress-induced heart failure and its relation to exosomal-microRNA378 (miRNA378). Methods The pressure overload heart failure model in vivo and in vitro were induced by transverse aortic constriction (TAC) in C57BL/6 mice for 4 weeks or by mechanical stretch on cultured cardiomyocytes for 48h, respectively. Fifteen C57BL/6 male mice were divided into control group, ascending aortic constriction group (TAC group) and ascending aortic constriction+ISMN group (TAC+ISMN group) in vivo experiment. The cultured cardiomyocytes were divided into 5 groups: control group, stretch group, stretch+miRNA378 mimic group, stretch+ISMN group and stretch+ISMN+miRNA378 inhibitor group. The echocardiography, heart weight/body weight ratio (HW/BW), the morphology of cardiomyocyte, plasma NT-proBNP and the expression of exosomal-microRNA378 were examined for in vivo model. The cardiomyocytes were collected and the mRNA expression of atrial natriuretic peptide (ANP) and skeletal-α-actin (SAA) was detected with RT-qPCR for in vitro model. Results In in vivo experiments, the LVIDd, LVAWd, HW/BW and plasma NT-proBNP levels in TAC+ISMN group were significantly lower than those in TAC group（P<0.05), FS in TAC+ISMN group was significantly higher than that in TAC group (P<0.05). RT-qPCR shows that the expression of exosomal-microRNA378 was significantly upregulated in TAC+ISMN group compared with TAC group（P<0.05). In in vitro experiments, the expressions of ANP and SAA in cardiomyocytes were significantly decreased in stretch+ISMN group and stretch+microRNA378 mimic group compared with stretch group（P<0.05), however, there were no significant differences between stretch+ISMN+microRNA378 inhibitor group and stretch group (P>0.05). Conclusion Isosorbide mononitrate inhibits mechanical stress-induced heart failure through upregulation of the exosomal-microRNA378 expression.