Silencing IL36R alleviates myocardial ischemia-reperfusion injury via SIRT1/FOXO1/DRP1 mediated mitochondrial fission of cardiomyocytes
Chen Jihong
Wei Yongjun
Meng Zilong
Zheng Baoshi
Abstract：Objective By establishing a deep hypothermic circulatory arrest(DHCA)model,this study explores the effects of inhibiting interleukin-36 receptor(IL36R)on the mitochondria of cardiomyocytes in rats undergoing DHCA and the related mechanisms.Methods Forty-two male adult SPF SD rats were randomly divided into 7 groups(6 rats per group):SHAM group(control group),DHCA group(cryopreservation group),Si-IL36R+DHCA group(transfection of silenced virus+cryopreservation group),Si-NC+DHCA group(transfection of silenced no-load virus+cryopreservation group),OE-IL36R+DHCA group(transfection of overexpressed virus+cryopreservation group),OE-NC+DHCA group(overexpression of no-load virus+cryopreservation),NAM+DHCA group(inhibitor+cryopreservation).In the viral transfection group,IL36R overexpressed or silenced virus was injected through the rat tail vein one month before surgery,and the corresponding no-load virus was injected simultaneously.In the NAM+DHCA group,the silencing information regulatory factor 1(SIRT1)inhibitor Nicotinamide(NAM)was injected 1 h before surgery.In addition to SHAM group,the other 6 were used to construct stereoscopic external circulation(CPB)model,and underwent cooling,stopping circulation,and rewarming for 2 hours.The morphological changes of cardiac tissue were observed by hematoxylin-eosin(HE)staining,mitochondrial morphology of cardiomyocytes was observed by transmission electron microscopy,the levels of creatine kinase isoenzyme MB(CKMB)and lactate dehydrogenase(LDH)in serum,and the levels of superoxide dismutase(SOD),malondialdehyde(MDA)and glutathione(GSH)in myocardial tissue homogenate were detected.Western Blot analysis was performed to detect the expression levels of pathway proteins SIRT1,FOXO1,mitochondrial dynamin DRP1 and its phosphorylated proteins p-DRP1(Ser616)and p-DRP1(Ser637).Results Silenced IL36R alleviated myocardial tissue damage and mitochondrial damage after cardiopulmonary bypass in rats,decreased myocardial oxidative stress level,increased SOD and GSH activities,decreased MDA content(P＜0.05),and increased protein expressions of SIRT1,FOXO1 and P-DRP1(Ser637),(P＜0.05).The protein expression of P-DRP1(Ser616)was inhibited(P＜0.05);on the contrary,after overexpression of IL36R or inhibition of SIRT1,myocardial tissue injury and mitochondrial injury were aggravated,oxidative stress level was increased,and protein expressions of SIRT1,FOXO1 and P-DRP1(Ser637)were decreased(P＜0.05).It promoted the expression of P-DRP1(Ser616)protein(P＜0.05).Conclusion Silencing IL36R plays a protective role in myocardial ischemia-reperfusion injury after cardiopulmonary bypass,and the protective mechanism may be achieved through the inhibition of DRP1-mediated mitochondrial hyperdivision of cardiomyocytes by upregulation of SIRT1/FOXO1.
Keywords：Extracorporeal circulationIschemia reperfusion injuryIL36RMitochondrial damage
Publication Date：2025-01-27
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 22-27 )