TRIM38 Protect Cardiomyocytes From Hypoxia/Reoxygenation Injury Via Tak1 Suppression

Objective: To investigate whether TRIM38 can improve myocardial ischemia/reperfusion(I/R)injury by regulating the ubiquitination of TRAF6 and inhibiting the TAK1-NF-ΚB pathway.By detecting the key proteins,apoptosis-related protein,oxidative stress index,pro-inflammatory factor and Lactate dehydrogenase release in TRIM38,TAK1,TRAF6,NF-κb signaling pathway,to explore the specific regulatory mechanism of TRIM38 on myocardial I/R injury in order to provide theoretical and experimental basis for clinical coronary artery disease.Methods: H9C2 cells were divided into control group(Ad GFP;Adsh RNA),overexpression/knock-down TRIM38 control group(Adtrim38;Adshtrim38),hypoxia/reoxygenation group(H/R GFP;H/R Adsh RNA),overexpression/knock-down TRIM38 hypoxia/reoxygenation group(H/R Adtrim38;H/R Adshtrim38),western blot was used to detect the expression levels of apoptosis-related proteins,Proinflammatory cytokine,and related molecular mechanisms.LDH release amount and oxidative stress index were improvedResults: Compared with the control group,the expression of pro-apoptotic protein in H/R group increased,and the expression of TRIM38 decreased significantly.The overexpression of TRIM38 could decrease the expression level of H/R proapoptotic protein,decrease the release of LDH,decrease the content of MDA,and increase the activity of SOD and GSH-Px.Knocking down Trim38 appears to have the opposite effect.The overexpression of TRIM38 reverses the expression of pro inflammatory cytokines and significantly reduces the expression of p-IKKα,p-p65 and p-IκBαinduced by Proinflammatory cytokine stimulation.H/R could up-regulate the expression of p-TAK1,but overexpression of TRIM38 could reverse the expression of P-TAK1.Knock-down of Trim38 upregulates p-TAK1,p-IKKα、p-IκBα and p-p65 expression induced by H/R in cardiomyocytes.TAK1 inhibitor reverses the expression of these proteins and attenuates apoptosis.Under H/R stimulation,the level of ubiquitination of TRAF6 increased,but the level of multiubiquitination of TRAF6 decreased when Trim38 was knocked down.Conclusion:(1)TRIM38 attenuates H/R induced apoptosis and oxidative stress in H9C2 cardiomyocytes.(2)Trim38 improves the inflammatory response of H9C2 cells after H/R by NF-ΚB pathway.(3)Trim38 attenuates myocardial I/R injury by regulating TAK1 to inhibit NF-κb signaling pathway.(4)the interaction between TRIM38 and TRAF6 induces the ubiquitin degradation of TRAF6,which leads to the inactivation of TAK1-NFΚB pathway.