Protective Effect Of Isoflurane Preconditioning On Myocardial Ischemia Reperfusion Injury In Rats By Regulating The Function Of Beclin1-vps34 Complex

ObjectiveTo investigate whether isoflurane preconditioning can protect rat myocardial ischemia reperfusion injury by regulating the function of Beclin1-Vps34 complex.MethodsEffects of isoflurane preconditioning on autophagy flux after myocardial ischemia reperfusion injury in rats:48 Male Sprague-Dawley rats,aged from 3 to 4 months,weighing from 200 to 250 g,were randomly divided into the following eight groups?n=12?:sham operation group?group Sham?,isoflurane preconditioning group?group ISO?,ischemia reperfusion group?group I/R?,isoflurane preconditioning+ischemia reperfusion group?group ISO+I/R?.In the ISO group,isoflurane 1.5 minimum alveolar concentration was administrated 30 min following a 15 min rest period to allow the end-tidal isoflurane concentration to reach zero.In the I/R group,animals underwent 30 min of LAD occlusion followed by 4h of reperfusion.In the ISO+I/R group,the rats received isoflurane precondition,then made myocardial ischemia reperfusion injury model.The TTC staining method to detect myocardial infarction;Elisa method was used to detect the level of cardiac troponin I?cTn I?;Western blot method for detection of Beclin1,Vps34,LC3,P62,Lamp-2 II/I and GAPDH expression levels.The effect of isoflurane preconditioning on the function of Beclin1-Vps34 complex:96 Male Sprague-Dawley rats,aged from 3 to 4 months,weighing from 200 to 250 g,were randomly divided into the following eight groups?n=12?:sham operation group?group Sham?,isoflurane preconditioning group?group ISO?,ischemia reperfusion group?group I/R?,isoflurane preconditioning+ischemia reperfusion group?group ISO+I/R?and Vps34inhibitor 3-MA group?group 3-MA?,3-MA+isoflurane preconditioning group?group3-MA+ISO?,3-MA+ischemia reperfusion group?group 3-MA+I/R?,3-MA+isoflurane preconditioning+ischemia reperfusion group?group 3-MA+ISO+I/R?.In 3-MA group,the rats were injected intraperitoneally with 3-MA 40mg/kg^-1 before experiment.In3-MA+ISO group,the rats received isoflurane precondition after 3-MA treatment.In3-MA+I/R group,the rats received 3-MA treatment and the rest were treated with I/R group.In 3-MA+ISO+I/R group,the rats received 3-MA treatment and the rest were treated with ISO+I/R group.The TTC staining method to detect myocardial infarction;Elisa method was used to detect the level of cardiac troponin I?cTn I?;Tunnel staining was used to detect the myocardial cell apoptosis;Western blot method for detection of Beclin1,Vps34,LC3,P62,Lamp-2 I/II,caspase-3 and GAPDH expression levels;CO-IP method was used to detect the binding level of Beclin1 and Vps34.ResultsCompared with I/R group,the myocardial infarction area of ISO+I/R group decreased?P<0.05?,the serum level of cTnI decreased?P<0.05?,Tunnel staining showed the apoptosis of myocardial cells decreased;compared with ISO+I/R group,3-MA+ISO+I/R group of myocardial infarction area increased significantly?P<0.05?,myocardial apoptosis level increased.Compared with Sham group,the expression level of Beclin1,Vps34,LC3 II/I,P62,Caspase-3 increased?P<0.05?and the level of Lamp-2 decreased?P<0.05?in I/R group;compared with I/R group,the expression level of Beclin1 Vps34,LC3 II/I,P62,Caspase-3 decreased?P<0.05?and the levels of Lamp-2 increased?P<0.05?in ISO+I/R group.Compared with Sham group,the expression level of Beclin1and Vps34 had no significant difference?P>0.05?,but the binding ability of Beclin1 and Vps34 enhanced in ISO group?P<0.05?;compared with ISO group,there was no significant difference between the expression level of Beclin1?P>0.05?,but the level of Vps34 and the binding ability of Beclin1 and Vps34 decreased in 3-MA+ISO group?P<0.05?;compared with I/R group,the expression level and binding ability of Beclin1 and Vps34 decreased in ISO+I/R group?P<0.05?;compared with ISO+I/R group,the expression level of Beclin1 and Vps34increased?P<0.05?,and the binding ability decreased in 3-MA+ISO+I/R group.ConclusionProtective effect of isoflurane preconditioning on myocardial ischemia reperfusion injury by enhancing Beclin1 and Vps34 binding capacity,promoting autophagy flux,and reducing myocardial apoptosis.