Hui Peng1, Yuxuan Luo2, Yongjun Ying3. 1. Department of Cardiology, Tongde Hospital of Zhejiang Province, 234 Gucui Road, Hangzhou, Zhejiang, China. 2. Department of Nephrology, Zhuji People's Hospital of Zhejiang province, Zhuji, Shaoxing, Zhejiang, China. 3. Department of Cardiology, Tongde Hospital of Zhejiang Province, 234 Gucui Road, Hangzhou, Zhejiang, China. Electronic address: yyyk9966@126.com.
Abstract
OBJECTIVE: To investigate the effect of lncRNA XIST on apoptosis induced by hypoxia. METHODS: We analyzed the expression levels of lncRNA XIST and miR-122-5p using RT-qPCR in hypoxia-induced cardiomyocytes. The mechanism by which lncRNA XIST affects myocardial ischemia was investigated using the cell transfection, CCK-8, and dual-luciferase reporter assays, as well as by flowcytometry, western blotting, and RNA immunoprecipitation. RESULTS: Hypoxic H9c2 cells demonstrated a decrease in their migration and invasion abilities and XIST expression and an increase in the extent of their apoptosis and expression of microRNA-122-5p. Overexpression of XIST significantly increased the H9c2 cell viability, enhanced cell migration and invasion, and decreased cell apoptosis in a hypoxic environment. The luciferase activity of XIST-WT in H9c2 cells co-transfected with XIST-WT and microRNA-122-5p mimics had decreased. The results of RNA immunoprecipitation showed that XIST interacted directly with miRNA-122-5p. Overexpression of XIST decreased the level of miRNA-122-5p significantly. mi-122-5p mimics increased H9c2 cell apoptosis and downregulated FOXP2 expression. Overexpression of FOXP2 upregulated the expression of the Bcl-2 protein in H9c2 cells transfected with microRNA-122-5p mimics and inhibited the expression of HIF-alpha, Bax, and the cleaved-caspase 9 protein. CONCLUSION: lncRNA XIST could regulate the miR-122-5p/FOXP2 axis to attenuate hypoxia-induced H9c2 cardiomyocyte injury.
OBJECTIVE: To investigate the effect of lncRNA XIST on apoptosis induced by hypoxia. METHODS: We analyzed the expression levels of lncRNA XIST and miR-122-5p using RT-qPCR in hypoxia-induced cardiomyocytes. The mechanism by which lncRNA XIST affects myocardial ischemia was investigated using the cell transfection, CCK-8, and dual-luciferase reporter assays, as well as by flowcytometry, western blotting, and RNA immunoprecipitation. RESULTS:HypoxicH9c2 cells demonstrated a decrease in their migration and invasion abilities and XIST expression and an increase in the extent of their apoptosis and expression of microRNA-122-5p. Overexpression of XIST significantly increased the H9c2 cell viability, enhanced cell migration and invasion, and decreased cell apoptosis in a hypoxic environment. The luciferase activity of XIST-WT in H9c2 cells co-transfected with XIST-WT and microRNA-122-5p mimics had decreased. The results of RNA immunoprecipitation showed that XIST interacted directly with miRNA-122-5p. Overexpression of XIST decreased the level of miRNA-122-5p significantly. mi-122-5p mimics increased H9c2 cell apoptosis and downregulated FOXP2 expression. Overexpression of FOXP2 upregulated the expression of the Bcl-2 protein in H9c2 cells transfected with microRNA-122-5p mimics and inhibited the expression of HIF-alpha, Bax, and the cleaved-caspase 9 protein. CONCLUSION: lncRNA XIST could regulate the miR-122-5p/FOXP2 axis to attenuate hypoxia-induced H9c2cardiomyocyte injury.