强心汤对慢性心力衰竭模型大鼠心肌组织OMA1、OPA1表达及线粒体形态的影响

Effect of Qiangxin Decoction(强心汤)on OMA1 and OPA1 Expression and Mitochondrial Morphology of Myocardial Tissue in Chronic Heart Failure Model Rats

目的探讨强心汤治疗慢性心力衰竭的可能作用机制。方法50只SD大鼠随机分为假手术组、模型组、金属蛋白酶相关蛋白1(OMA1)封闭组、强心汤组、OMA1封闭+强心汤组,每组10只。除假手术组外其余各组大鼠采用结扎左冠状动脉前降支建立慢性心力衰竭大鼠模型,OMA1封闭组和OMA1封闭+强心汤组在建立模型前第1和第7天各尾静脉注射2×10^(10)pfu OMA1干扰腺病毒对大鼠OMA1表达封闭。自建模成功后第2天开始,强心汤组、OMA1封闭+强心汤组给予强心汤混悬液每次1.62g/kg灌胃,每天2次;其余各组给予2ml生理盐水灌胃,每天2次。各组均灌胃14天后检测心功能,包括左室舒张末期内径(LVDD)、左室收缩末期内径(LVDS)、射血分数(EF);采用RT-PCR和免疫组化检测各组大鼠心肌组织OMA1、视神经萎缩蛋白1(OPA1)mRNA表达及OMA1、OPA1、长链形式视神经萎缩蛋白1(L-OPA1)、短链形式视神经萎缩蛋白1(S-OPA1)蛋白表达,同时通过透射电镜观察各组大鼠心肌组织线粒体形态。结果与假手术组比较,模型组大鼠LVDD、LVDS升高,EF降低,心肌组织OMA1 mRNA和OMA1、S-OPA1蛋白表达升高,OPA1 mRNA和OPA1、L-OPA1蛋白表达降低(P<0.05),线粒体呈重度肿胀,大多线粒体板呈不规则形、膜内基质变淡,嵴断裂、消失。与模型组比较,各干预组大鼠上述各指标均明显改善,且OMA1封闭+强心汤组改善程度优于OMA1封闭组和强心汤组,OMA1封闭组改善程度优于强心汤组(P<0.05)。结论强心汤可能通过抑制OMA1表达、降低OPA1的蛋白水解及减少L-OPA1向S-OPA1过度裂解,从而发挥保护线粒体形态和改善心功能的作用,并且能与OMA1基因封闭发挥协同作用。

Objective To explore the possible mechanism of Qiangxin Decoction(强心汤)in the treatment of chronic heart failure.Methods Fifty SD rats were randomly divided into sham operation group,model group,overlapping metalloproteinase associated protein 1(OMA1)blocking group,Qiangxin Decoction group,and the combination of OMA1 blocking and Qiangxin Decoction group,with 10 rats in each group.The left anterior descending coronary artery was ligated to establish a chronic heart failure model in rats of all groups except for sham operation group.Before establishing the model,the OMA1 group and the combination group injected 2×10^(10)pfu OMA1 interference adenovirus to the rats'tail veins to block the expression of OMA1.From the second day after the modelling,Qiangxin Decoction was administered by gavage in Qiangxin Decoction group and the combination group,with 1.62 g/kg per time,twice daily,while normal saline was administered in other groups by gavage,2 ml per time,twice daily.The heart function was measured 14 days after intragastric administration,including left ventricular end-diastolic diameter(LVDD),left ventricular end-systolic diameter(LVDS),and ejection fraction(EF);RT-PCR and immunohistochemistry were used to detect the mRNA expression of OMA1 and optic atrophin 1(OPA1)in myocardial tissue,as well as the protein expression of OMA1,OPA1,long form of optic atrophy 1(L-OPA1),and short form of optic atrophy 1(S-OPA1);transmission electron microscope was used to observe the mitochondrial morphology in myocardial tissue.Results Compared to sham operation group,the LVDD and LVDS levels in the model group increased;the EF level decreased;the mRNA expression of OMA1 and the protein expression of OMA1 and S-OPA1 increased;the mRNA expression of OPA1 and the protein expression of OPA1 and L-OPA1 decreased(P<0.005);severe edema could be seen in the mitochondria;most of the mitochondrial plates had irregular forms;paler intramembranous matrix,as well as crista fragmentation and disappearance were found.Compared to model group,the above measurements were all improved in three intervention groups,with most improvements in the combination group followed by OMA1 group and Qiangxin Decoction group(P<0.05).Conclusion Qiangxin Decoction can help protect mitochondrial morphology and improve heart function,through inhibiting the expression of OMA1,reducing the proteolysis of OPA1,and decreasing the excessive cleavage of L-OPA1 to S-OPA1.And Qiangxin Decoction together with OMA1 blocking play a synergistic effect.