lncRNA ANRIL protects H9c2 cells against hypoxia-induced injury through targeting the miR-7-5p/SIRT1 axis

Background: Acute myocardial infarction (AMI) occurred in the heart, which underwent long-term ischemia, and was mainly caused by hypoxia. Recently, studies have uncovered the participation of long noncoding RNAs (lncRNAs) in the pathogenesis of heart disease. Here, we planned to probe the role and molecular basis of ANRIL in hypoxia-induced H9c2 cell injury. Methods: Trypan blue exclusion assay and Transwell and flow cytometry assays were conducted to assess hypoxia-induced injury by determining the viability, migration, invasion, and apoptosis of H9c2 cells in different conditions, respectively. Gene expressions were evaluated by quantitative real-time polymerase chain reaction or western blot analysis as needed. RNA immunoprecipitation and luciferase reporter assays were applied to confirm the associations among genes. Results: ANRIL expression was dramatically enhanced in hypoxia-injured H9c2 cells, and silencing ANRIL aggravated hypoxia-induced H9c2 cell injury. ANRIL positively regulated sirtuin 1 (SIRT1) expression via competitively binding with miR-7-5p. Moreover, inhibition of miR-7-5p counteracted ANRIL depletion-exacerbated injury in hypoxic H9c2 cells, meanwhile, forced SIRT1 expression attenuated the injury-promoting effect of miR-7-5p upregulation on hypoxic H9c2 cells. Conclusion: Our findings disclosed that ANRIL plays a protective part in hypoxia-induced H9c2 cell injury via modulating the miR-7-5p/SIRT1 axis, suggesting the great potential of ANRIL as a protective target for AMI.