敲低阿霉素心肌病大鼠心肌细胞ADAM10后大鼠心功能的改善及机制

Improvement and the mechanism of cardiac function by knockdown of ADAM10 in adriamycin-induced cardiomyopathy rats

目的建立阿霉素心肌病动物模型,观察解整合素金属蛋白酶10(ADAM10)小干涉RNA(siRNA)重组慢病毒对神经钙黏素(N-cadherin)加工水解途径的调控。方法 SD大鼠腹腔注射阿霉素,建立阿霉素心肌病大鼠模型。将ADAM10 siRNA重组慢病毒进行心内注射,分为模型组、重组慢病毒治疗组、空白载体组及正常对照组。分离原代心肌细胞,观察绿色荧光蛋白(GFP)的表达,确定感染效率。超声检测各组大鼠心功能,HE染色观察心肌组织病变情况,Western blot法检测心肌细胞N-cadherin在ADAM10水解后产生的C末端片段1(CTF1)的蛋白水平,免疫组织化学染色检测心肌组织N-cadherin的表达和分布。结果原代培养的感染后心肌细胞可见大量GFP表达,说明慢病毒成功感染心肌细胞;与阿霉素心肌病组相比,ADAM10 siRNA重组慢病毒治疗组死亡率下降,心功能及心肌组织形态明显改善,心肌细胞N-cadherin蛋白水平增加并主要定位于细胞表面、CTF1蛋白水平降低。结论敲低ADAM10水平,增加阿霉素心肌病大鼠心肌细胞N-cadherin的表达、降低CTF1的表达,改善心功能。

Objective To study the role of a disintegdn and metalloproteinase10 （ADAM10） in shedding neural oadherin （N-cadherin） and develop an approach to interfere the process of ventricular remodeling in edriamycin-induced cardiomyopathy （ACM） rats. Methods In a rat model of ACM, the effects of intraperitoneal injection of the lentiviral RNAi vector of ADAM10 on the morphology of cardiornyocytes and contractile function were observed by HE staining and color Doppler echocardiography. The expressions of N-cadherin and C-terminal fragment 1 （CTF1） were detected by Western blotting and immunohistcohemistry. Results In the in vivo experiment, a large amount of fluorescence was seen in the isolated primary cardiomyocytes, which indicated that the transfection in the rat model was successful. In the treatment group, the morphology of cardiornyocytes and function of the heart were evidently improved, N-cadherin protein expression was remarkably up-regulated and CTF1 protein was obviously down-regulated compared with the model group. Conclusion Knock-down of ADAM10 increases N-cadherin expression and decreases CTF1 expression, thus improves cardiac function in the rat model of ACM.