UCP2 overexpression activates SIRT3 to regulate oxidative stress and mitochondrial dynamics induced by myocardial injury

Our previous study found that overexpression of uncoupling protein-2 (UCP2) had a protective effect on lipopolysaccharide (LPS)-induced sepsis cardiomyocytes. The aim of this study was to explore the effect and mechanism of uncoupling protein-2 (UCP2) on myocardial ischemia-reperfusion injury. In this study, we established hypoxia-reoxygenation (HR) injury model in rats and isolated cardiomyocytes of newborn rats. We also carried out following methods which include virus transfection technology, cell counting Kit-8 (CCK8), flow cytometry, enzyme linked immunosorbent assay (ELISA), Western blot (WB), quantitative reverse transcription PCR (RT qPCR), transmission electron microscopy, fluorescence colocalization and immunoprecipitation. The results of this study showed that hypoxia-reoxygenation treatment in cardiomyocytes increased UCP2, myocardial enzyme and myocardial apoptosis and weakened cardiomyocyte viability. We observed increased cardiomyocyte viability and mitochondrial membrane potential, decreased myocardial enzyme and myocardial apoptosis, Inhibition of oxidative stress when UCP2 was overexpressed in cardiomyocytes. It also can Increase ATP and stabilize mitochondrial dynamics. Further studies founded that Sirtuin-3(SIRT3) changed with the expression of UCP2, which was confirmed by fluorescence co-localization and immunoprecipitation. Our findings revealed that UCP2 and SIRT3 were important targets of anti-myocardial injury by inhibiting cellular oxidative stress and stabilizing mitochondrial dynamics.