Effects Of Electroacupuncture And Moxibustion Pretreatment On Expression Of Autophagy Protein LC 3? And Beclin 1 In Rats With Myocardial Ischemia-reperfusion Injury

Objective: To observe the effect of electuroacupuncture(EA)and moxibustion(Moxi)pretreatment on expression of autophagy related protein LC 3 II and Beclin 1 in rats with myocardial ischemia-reperfusion injury(MIRI),and to explore the mechanism of EA and Moxi pretreatment on autophagy in MIRI and to compare the effect difference of EA and Moxi with IP pretreatment.Methods: 40 SD rats were randomly divided into sham operation group,model group,ischemic pretreatment(IP)group,EA group and Moxi group(n=8 in each).EA and Moxi pretreatment were respectively applied to bilateral “Neiguan”(PC 6)for 20 min,once daily for 7 days.The classic coronary artery ligation was conducted in each group respectively to replicate the model of myocardial ischemia and reperfusion injury after pretreatment at 7 days.The pathological and ultrastructural changes of left ventricular ischemia tissue were observed under light and transmission electronic miroscope(TEM),respectively.Tunel was used to detect the apoptosis and apoptosis index of myocardial cell,and the expression of LC 3and Beclin 1 in myocardial cells were detected by Western blot.Results:1.Results of HE staining and ultrastructure in rats:Outcomes of H.E staining and ultrastructure showed that model group myocardial injury was serious,myocyte disarray,fuzzy boundaries,the infiltration of inflammatory cells,striated part necrosis,dissolution,disorder,mitochondrial structure fuzzy,severe vacuolization,and the emergence of large autophagosome double membrane structure.And IP group,EA group and Moxi group was minor myocardial injury,muscle fiber mostly normal,myofilament focal edema,mitochondria rich with vacuole and occasionally autophagosome.2.Tunel results:Compared with sham operation group,apoptosis index of model group was significantly higher than that of sham operation group(P<0.01);And apoptosis index of IP group,EA group,Moxi group were significantly lower than the model group(P<0.01);EA group apoptosis index was lower than IP group and Moxi group(P<0.05).3.Expression of LC 3 and Beclin 1 protein:The ratio of LC 3 II/LC3 I and expression of LC 3 II and Beclin 1 of model group was obviously ascended compared with sham operation group(P<0.01).And the ratio of LC 3 II/LC 3I and expression of LC 3 II Beclin 1 of IP group,EA group and Moxi group was significantly decreased compared with model group(P<0.01);The ratio of LC 3 II/LC 3 I and expression of LC 3 II and Beclin 1 of EA group were significantly lower than IP group and Moxib group(P<0.05).No significant differences were found between IP group and Moxi group expressions of LC3 II and Beclin 1 and apoptosis index(P>0.05).Conclusion:IP,EA or Moxi pretreatment Neiguan(PC6)had a protective effect on MIRI rats,regulated the process of autophagy on MIRI rats,could down regulate the expression of LC 3II,Beclin 1 protein and reduce the ratio of LC 3II/LC3 I namely,and EA Neiguan(PC6)effect was optimum on regulated myocardial autophagy in MIRI rats especially.And the mechanismof moderate-regulation autophagy,anti-apoptosis and promoting myocardial cell survival in MIRI which may be associated with the Beclin 1 mediated autophagy/apoptosis.