MicroRNA-7a/b protects against cardiac myocyte injury in ischemia/reperfusion by targeting poly(ADP-ribose) polymerase.

• Main Authors: Bin Li, Rui Li, Chun Zhang, Hong-jun Bian, Fu Wang, Jie Xiao, Shan-wen Liu, Wei Yi, Ming-xiang Zhang, Shuang-xi Wang, Yun Zhang, Guo-hai Su, Xiao-ping Ji
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2014-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC3940823?pdf=render
• ISSN: 1932-6203

OBJECTIVES: MicroRNA-7 (miR-7) is highly connected to cancerous cell proliferation and metastasis. It is also involved in myocardial ischemia-reperfusion (I/R) injury and is upregulated in cardiomyocyte under simulated I/R (SI/R). We aimed to investigate the role of miR-7 during myocardial I/R injury in vitro and in vivo and a possible gene target. METHODS AND RESULTS: Real-time PCR revealed that miR-7a/b expression was upregulated in H9c2 cells after SI/R. Flow cytometry showed SI/R-induced cell apoptosis was decreased with miR-7a/b mimic transfection but increased with miR-7a/b inhibitor in H9c2 cells. In a rat cardiac I/R injury model, infarct size determination and TUNEL assay revealed that miR-7a/b mimic decreased but miR-7a/b inhibitor increased cardiac infarct size and cardiomyocyte apoptosis as compared with controls. We previously identified an important gene connected with cell apoptosis--poly(ADP-ribose) polymerase (PARP)--as a candidate target for miR-7a/b and verified the target by luciferase reporter activity assay and western blot analysis. CONCLUSIONS: miR-7a/b is sensitive to I/R injury and protects myocardial cells against I/R-induced apoptosis by negatively regulating PARP expression in vivo and in vitro. miR-7a/b may provide a new therapeutic approach for treatment of myocardial I/R injury. Poly(ADP-ribose) polymerase.