Effects Of IL-33 In The Anoxia/Reoxygenation-Induced Cardiomyocyte Programmed Necrosis

Background and Object:Acute myocardial infarction(AMI)is the most common cardiovascular disease and the leading cause of death worldwide.The most effective treatment of AMI is to promptly restore blood flowwhich includethrombotic therapy,coronary artery bypass graft,or percutaneous coronary intervention.However,reperfusion itself induced additional myocardial cell death,which is named myocardial ischemia/reperfusion injury.Necrosis is the major cell death involved in reperfusion-induced myocardial cell death.Necrosis includes ordinary necrosis and programmed necrosis-necroptosis.Necroptosis is triggered by tumor necrosis factor Receptor(TNFR),followed by the activation of necroptotic pathway including Receptor-Interacting Protein Kinase-3(RIP3),Receptor-Interacting Protein Kinases 1(RIP1)and Mixed Lineage Kinasedomai-Like(MLKL).Which is called necrosome.The activation of necrosome further caused necroptotic cell death.Studies have shown that receptor-protein kinases3(RIPK3)plays a key role in necroptosis.Recent studies found that Interleukin-33(IL-33)is a cytokine with significant protective effects on the cardiovascular system.In a latest study,IL-33 exhibits an anti-myocardial fibrosis function and alleviates high-fat diet-induced atherosclerosis.Furthermore,we have previously demonstrated that recombinant IL-33 protects myocardial cell from apoptosis after ischemia/reperfusion.Methods:Cardiomyocytes were isolated from neonatal rats and cultured with M199 containing10% fetal calf serum.The anoxia/reoxygenation(A/R)challenge to cardiomyocytes was established to simulate myocardial ischemia/reperfusion injury in vivo.The cardiomyocytes were challenged with either A/R,or precondition with different concentration(0,0.2,1,5ng/ml)of recombinant IL-33 followed by A/R.The control cardiomyocytes were challenged with normoxia/reoxygenation(N/R).RIP3 protein expression was measured by Western blot.Cell survival rate was detected with CCK8 kit.Cardiomyocyte necrosis was detected with LDH kit.Cardiomyocyte death was observed by PI staining.Results:A/R increased the RIP3 protein expression in cardiomyocytes which was associated with increased cardiomyocyte necrosis as indicated by increased cardiomyocyte LDH release and decreased cardiomyocyte survival rate and increased cardiomyocyte positive PI staining.Pretreatment of cardiomyocytes with the recombinant IL-33(5ng/ml)prevented the A/R-induced increase in RIP3 expression and attenuated A/R-induced cardiomyocyte necroptosis.Conclusions:The results of this study suggest that IL-33 prevents the A/R-induced cardiomyocyte necroptosis by inhibition of A/R-induced increase in RIP3 expression.