miR-346缓解心肌缺血再灌注大鼠心肌氧化应激损伤

miR-346 relieving myocardial oxidative stress injury in rats undergoing myocardial ischemia/reperfusion

目的分析miR-346缓解心肌缺血再灌注(I/R)损伤大鼠心脏功能受损和氧化应激的作用。方法将48只大鼠随机分为对照组、I/R组、I/R+agomiR-NC组和I/R+agomiR-346组,采用结扎左冠状动脉前降支法复制I/R模型,尾静脉注射重组腺相关病毒miR-346进行过表达干预。再灌注120 min后,检测心率(HR)、左心室射血分数(LVEF)、短轴缩短率(FS)和左心室壁厚度(LVWT),检测血清肌酸激酶同工酶(CK-MB)、肌红蛋白(Mb)、乳酸脱氢酶(LDH)、心肌肌钙蛋白I(cTnI)水平,检测心肌组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和丙二醛(MDA)水平,TUNEL染色检测心肌组织细胞凋亡,Western blot检测心肌组织B细胞淋巴瘤/白血病(Bcl)-2基因、Bcl相关蛋白(Bax)、半胱氨酸蛋白酶(Cas)-3、Cas-9表达。结果I/R组大鼠HR、LVEF、FS和LVWT低于对照组,血清CK-MB、LDH、Mb和cTnI水平高于对照组,心肌组织MDA、Bax/Bcl-2、cleaved Cas-3/Cas-3和cleaved Cas-9/Cas-9蛋白表达高于对照组,SOD和GSH-px水平低于对照组,心肌组织细胞凋亡率高于对照组(P<0.05);I/R+agomiR-346组大鼠HR、LVEF、FS和LVWT高于I/R+agomiR-NC组,血清CK-MB、LDH、Mb和cTnI低于I/R+agomiR-NC组,心肌组织MDA、Bax/Bcl-2、cleaved Cas-3/Cas-3和cleaved Cas-9/Cas-9蛋白表达低于I/R+agomiR-NC组,SOD和GSH-px水平高于I/R+agomiR-NC组,心肌组织细胞凋亡率低于I/R+agomiR-NC组(P<0.05)。结论miR-346过表达可以降低I/R大鼠的氧化应激水平,减轻心肌组织损伤,改善心功能。

Objective To analyze the effects of miR-346 on alleviating cardiac function damage and oxidative stress in rats undergoing myocardial ischemia/reperfusion(I/R).Methods A total of 48 rats were randomly divided into control group,I/R group,I/R+agomiR-NC group and I/R+agomiR-346 group.I/R model was replicated by the ligation of left anterior descending coronary artery.The recombinant adeno-associated virus miR-346 was injected through the tail vein for overexpression intervention.After 120 minutes of reperfusion,heart rate(HR),left ventricular ejection fraction(LVEF),fractional shortening(FS)and left ventricular wall thickness(LVWT),levels of serum creatine kinase MB(CK-MB),myoglobin(Mb),lactate dehydrogenase(LDH)and cardiac troponin I(cTnI),and levels of superoxide dismutase(SOD),glutathion peroxidase(GSH-Px)and malondialdehyde(MDA)in myocardial tissues were detected.The apoptosis of myocardial tissue cells was detected by TUNEL staining.The expression of B-cell lymphoma/leukemia-2(Bcl-2)gene,Bcl-associated x protein(Bax),cysteine protease 3(Cas-3)and Cas-9 in myocardial tissues was detected by Western blot.Results HR,LVEF,FS and LVWT in I/R group were lower than those in control group,the levels of serum CK-MB,LDH,Mb and cTnI were higher than those in control group,the expression of MDA,Bax/Bcl-2,cleaved Cas-3/Cas-3 and cleaved Cas-9/Cas-9 proteins in myocardial tissues was higher than that in control group,the levels of SOD and GSH-px were lower than those in control group,and the apoptosis rate of myocardial tissue cells was higher than that in control group(P<0.05).HR,LVEF,FS and LVWT in I/R+agomiR-346 group were higher than those in I/R+agomiR-NC group,the levels of serum CK-MB,LDH,Mb and cTnI were lower than those in I/R+agomiR-NC group,the expression of MDA,Bax/Bcl-2,cleaved Cas-3/Cas-3 and cleaved Cas-9/Cas-9 proteins in myocardial tissues was lower than that in I/R+agomiR-NC group,the levels of SOD and GSH-px were higher than those in I/R+agomiR-NC group,and the apoptosis rate of myocardial tissue cells was lower than that in I/R+agomiR-NC group(P<0.05).Conclusion The miR-346 overexpression can reduce oxidative stress level in I/R rats,alleviate myocardial tissue damage,and improve cardiac function.