The Regulation Of Cardiomyoctyes Mitoflash By Overexpression Of UCP2 Protects The Endotoxin-induced Myocardial Injury

Objective: The aim of this study is to explored whether UCP2 overexpression can regulate the frequency of myocardial mitochondrial hypophysis and whether it has a protective effect on the myocardium,on the model of myocardial injury induced by lipopolysaccharide.Methods: Primrary myocardial cells of neonatal rats were isolated and cultured.A cell model for sepsis-induced myocardial damage was established using lipopolysaccharide(LPS).We used UCP2 over expression adenovirus and empty adenovirus to transfect cardiac myocytes,respectively.Cultures were randomly grouped into 6 groups as follows: normal group,UCP2 overexpressed group,empty vector group,LPS group,LPS+UCP2 overexpressed group,and LPS+empty vector group.We use cp-YFP adenovirus to transfect cardiomyocytes to make the mitochondria of cardiac myocytes express cp-YFP.The expression profiles of cp YFP in myocardial cells were imaged using confocal laser scanning microscopy.Collected images were analyzed utilizing Flash Sniper to quantify mitoflash frequency.The levels of creatinine kinase(CK),lactate dehydrogenase(LDH),tumor necrosis factor ?(TNF-?),and interleukin 6(IL-6)was detected.Tetramethylrhodamine methyl ester(TMRM)staining was employed for the detection of mitochondrial membrane potential(MMP).UCP2 protein expression measured by western blotting in all groups.Results:(1)Compared to control group,the frequency of mitoflashes,the level of CK,LDH,TNF-?,and IL-6 signicantly increased in LPS group(P<0.05).(2)Compared with LPS group,the frequenc y of mitoflash,the level of CK,LDH,TNF-?,and IL-6 markedly decreased,but were higher than normal group(P<0.05).In addition,MMP in LPS+UCP2 overexpressed group was higher than that in LPS group,but lower than that in control group(P<0.05).(3)Compared to normal group,the UCP2 expression in LPS group was significantly upregulated,but was lower than that in UCP2 overexpressed group and LPS+UCP2 overexpressed groups(P<0.05).(4)The expression of UCP2 protein in UCP2 overexpression group and LPS+UCP2 overexpression group was significantly higher than that in normal group and LPS group(P<0.05).(5)Empty virus transfection has no significant effect on cardiac myocytes.Conclusion: UCP2 overexpression partially reverse the myocardial injury induced by LPS stimulation,and play a cardioprotective role by reduce the production of excessive ROS in septic cardiomyocytes.