Effects Of Trimetazidine On Pyroptosis Of Hypoxia/Reoxygenation Cardiomyocytes

BackgroundRecurrent perfusion therapy when acute myocardial infarction(AMI)occurs is the most effective way to reduce infarct size,but when the ischemic myocardium restores blood supply,it may cause local myocardial tissue damage or other cardiac dysfunction,leading to myocardial Ischemia-reperfusion injury(MIRI)has been shown to be involved pyroptosis in MIRI.Cellular caliber mainly depends on the activation of NLRP3 inflammatory bodies.Activation of NLRP3 activates caspase through ASC recruitment,caspase-1 forms active IL-18 and IL-1? by cleavage of precursor IL-18 and IL-1 ?(pro-IL-18 pro-IL-1?)and releases it to produce an inflammatory response.Trimetazidine can protect the ischemic myocardium by inhibiting apoptosis,inflammation,autophagy and other mechanisms,but there are few studies on the effect of trimetazidine on pyroptosis.ObjectivesIt is clear whether H9C2 cells treated with hypoxia/reoxygenation have pyroptosis formation;whether trimetazidine can protect against hypoxia/reoxygenation myocardial cell injury by inhibiting pyroptosis.It provides new ideas and therapeutic targets for the treatment of myocardial ischemia-reperfusion injury.MethodsRat myocardial ischemia-reperfusion injury was simulated by H9C2 cells treated with hypoxia for 12h/reoxygenation for 4h.Cardiomyocytes were randomly divided into 5groups: normal control group and hypoxia/reoxygenation group H/R group),hypoxia/reoxygenation + trimetazidine 50?mol/L group(hypoxia/Reoxygenation+trimetazidine50?mol/L group,H/R+TMZ 50?mol/L group),hypoxia/reoxygenation +trimetazidine 100?mol /L group(hypoxia/Reoxygenation+ trimetazidine 100?mol/L group,H/R+TM-Z100?mol/L group),hypoxia/reoxygenation + trimetazidine 500?mol/L group(hypoxia/Reoxyg-enation+ trimetazidine 500?mol/L group,H/R+TMZ 500 ?mol/L group).The activity of cardiomyocytes in each group was detected by CKK8 method;the activity of LDH in each group was detected by lactate dehydrogenase(LDH)kit;the expression levels of caspase-1,ASC and NLRP3 in cardiomyocytes of each group were detected by western blot.The changes of caspase-1,ASC and NLRP3 mRNA expression in cardiomyocytes of each group were detected by real-time PCR.Results1.Comparison of cardiomyocyte viability in each group Compared with the normal control group(144.3 ± 5.6),the activity of cardiomyocytes in the H/R group was decreased(50.1 ± 4.9#)(P<0.05);compared with the H/R group,H /R+TMZ 50?mol/L group(77.2 ±3.7),H/R+TMZ 100?mol/L group(103.4 ± 15.4),H/R+TMZ 500?mol/L group(77.6 ± 1.3)increased cell viability(P< 0.05),wherein the increase in H/R+TMZ 100 ?mol/L group was most pronounced.2.Compared with the normal control group The LDH leakage of myocardial cells in the H/R group was significantly increased compared with the normal control group(P<0.05).Compared with the H/R group,the different concentrations were observed.After pretreatment with methotazol,the leakage of LDH in H9C2 cells treated with H/R was decreased(P<0.05).3.The cytotoxicity test showed a significant increase in LDH activity(21.3 ± 0.3)in the H/R group compared with the normal control group(21.3 ± 0.3)(P<0.05);compared with the H/R group,H/R +TMZ 50?mol/L group(80.6 ± 1.7),H/R+TMZ 100?mol/L group(43.1 ± 1.3),H/R+TMZ 500?mol/L group(59.21 ± 1.3)LDH activity decreased(P<0.05)Among them,H/R+TMZ 100?mol/L group was the most obvious decrease.4.The effect of trimetazidine on the expression ofpyroptosisrelated protein in H/R cardiomyocytes compared with the normal control group,the expression of Caspase-1,NLRP3 and ASC protein in H/R group increased,and H/R group The expression of Caspase-1,NLRP3 and ASC protein in the three groups pretreated with different concentrations of trimetazidine was statistically different,and the decrease was most significant in the 100 ?mol/L trimetazidine pretreatment group.Conclusions1.Cardiomyocyte injury caused by hypoxia/reoxygenation has the involvement of pyroptosis;2.Trimetazidine protects cardiomyocytes by inhibiting pyroptosis;3.The optimum concentration of trimetazidine for cardiomyocytes was 100?mol/L.