亚精胺对心肌梗死大鼠心肌线粒体功能及细胞凋亡的影响

Effects of spermidine on cardiomyocyte and mitochondrial function apoptosis in rats with myocardial infarction

目的:探讨亚精胺对心肌梗死大鼠心肌线粒体功能及细胞凋亡的影响。方法:选取健康SD大鼠32只,随机分为假手术组、模型组、模型+阿司匹林组、模型+亚精胺组,每组8只,利用在体结扎冠状动脉前降支法建立急性心肌梗死模型。造模成功后假手术组和模型组给予无菌生理盐水(2 mL)灌胃,模型+阿司匹林组以等体积阿司匹林(20 mg/kg)灌胃,模型+亚精胺组以等体积亚精胺(5 mmol/L)灌胃,连续4周。TTC染色、HE染色观察心肌组织梗死面积和病理学改变;透射电镜观察心肌线粒体形态;原位缺口末端标记(TUNEL)法检测心肌组织细胞凋亡水平;实时荧光定量PCR(qRT-PCR)检测Bax、Bcl-2、胱天蛋白酶-3(caspase-3)的mRNA表达水平;Western blot检测Bcl-2、Bax、caspase-3、细胞色素C(cytochrome C)的蛋白表达水平。结果:与假手术组比较,模型组大鼠心肌组织梗死区面积增加,心肌组织细胞凋亡明显增加,心肌组织Bax、caspase-3、cytochrome C表达水平明显升高,Bcl-2表达水平明显降低(P均<0.01);与模型组比较,模型+亚精胺组大鼠心肌组织梗死区面积减少,心肌组织细胞凋亡及Bax、caspase-3、cytochrome C表达水平均明显减少(P<均0.05);与模型+阿司匹林组比较,模型+亚精胺组心肌组织细胞凋亡明显降低(P<0.01),两组心肌组织Bax、caspase-3、Bcl-2、cytochrome C表达水平的差异无统计学意义。结论:亚精胺可改善心肌线粒体功能,抑制细胞凋亡,改善心肌梗死。

Objective:To investigate the effect of spermidine on cardiomyocyte apoptosis and mitochondrial function in rats with myocardial infarction.Methods:A total of 32 healthy SD rats were randomly divided into sham operation group,model group,model+aspirin group and model+spermidine group,with 8 rats in each group.The acute myocardial infarction model was established by ligating the anterior descending coronary artery in vivo.After successful establishment of the model,the rats in the sham operation group and the model group were given sterile normal saline(2 mL),while the rats in the model+aspirin group were given intragastric administration of 20 mg aspirin/kg body weight,and the rats in the model+spermidine group were intragastrically administered with spermidine(5 mmol/L)for 4 weeks.TTC staining and HE staining were used to observe the myocardial infarct size and pathological changes of myocardial tissue,the morphology of mitochondria was observed by transmission electron microscope,the apoptosis of myocardial tissue was detected by the TdT-mediated dUTP-biotin nick end labeling(TUNEL)assay,and the expression of Bax,Bcl-2 and Caspase-3 mRNA was detected by quantitation real-time reverse transcription-PCR(qRT-PCR);the expression of Bcl-2,Bax,caspase-3 and cytochrome C protein was detected by western blot.Results:Compared with the sham group,the infarct size was larger and the cardiomyocyte apoptosis was aggravated,the expression level of Bax,caspase-3 and cytochrome C in the myocardial tissue was significantly higher,and the expression level of Bcl-2 was significantly lower in the model group(all P<0.01).Compared with the model group,the infarct size was smaller,and the cardiomyocyte apoptosis was alleviated,and the expression level of Bax,caspase-3 and cytochrome C were significantly lower in the model+spermidine group(all P<0.05).Compared with the model+aspirin group,myocardial apoptosis was alleviated significantly in the model+spermidine group(P<0.01),but there was no significant statistical difference in the expression of Bax,caspase-3,Bcl-2 and cytochrome C between the two groups(all P>0.05).Conclusions:Spermidine could significantly improve mitochondrial function and inhibit cardiomyocyte apoptosis.