Role of microRNA-195 in cardiomyocyte apoptosis induced by myocardial ischaemia–reperfusion injury

Journal of genetics

Zhao-Guang Liang³  Chang-Kui Gao1²  Ye Tian4³  Hui Liu¹  Cheng-Ji Cui⁴  Hong Yao³ 

[1] Department of Clinical Laboratory, Women and Children Hospital of Qingdao, Qingdao 266000, People’s Republic of China$$;Department of Emergency, Longnan Hospital of Daqing, Daqing 163001, People’s Republic of China$$;Department of Laboratory, The First Hospital of YanTai, YanTai 261400, People’s Republic of China$$;Department of Nephrology, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun 130000, People’s Republic of China$$

关键词: microRNA-195;    ischaemia–reperfusion;    hypoxia/reoxygenation;    cardiomyocyte apoptosis;    Bcl-2;    Bax;    Cyt-c;    caspase-3;    caspase-9;    mitochondrial membrane potentia.;   

DOI  :  

学科分类：生物科学（综合）

来源: Indian Academy of Sciences

【 摘 要 】

This study aims to investigate microRNA-195 (miR-195) expression in myocardial ischaemia–reperfusion (I/R) injury and the roles of miR-195 in cardiomyocyte apoptosis though targeting Bcl-2. A mouse model of I/R injury was established. MiR-195 expression levels were detected by real-time quantitative PCR (qPCR), and the cardiomyocyte apoptosis was detected by TUNEL assay. After cardiomyocytes isolated from neonatal rats and transfected with miR-195 mimic or inhibitor, the hypoxia/reoxygenation (H/R) injury model was established. Cardiomyocyte apoptosis and mitochondrial membrane potential were evaluated using flow cytometry. Bcl-2 and Bax mRNA expressions were detected by RT-PCR. Bcl-2, Bax and cytochrome c (Cyt-c) protein levels were determined by Western blot. Caspase-3 and caspase-9 activities were assessed by luciferase assay. Compared with the sham group, miR-195 expression levels and rate of cardiomyocyte apoptosis increased significantly in I/R group (both 𝑃 < 0.05). Compared to H/R + negative control (NC) group, rate of cardiomyocyte apoptosis increased in H/R + miR-195 mimic group while decreased in H/R + miR-195 inhibitor group (both 𝑃 < 0.05). MiR-195 knockdown alleviated the loss of mitochondrial membrane potential (𝑃 < 0.05). MiR-195 overexpression decreased Bcl-2 mRNA and protein expression, increased BaxmRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all 𝑃 < 0.05). While, downregulated MiR-195 increased Bcl-2 mRNA and protein expression, decreased Bax mRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all 𝑃 < 0.05). Our study identified that miR-195 expression was upregulated in myocardial I/R injury, and miR-195 overexpression may promote cardiomyocyte apoptosis by targeting Bcl-2 and inducing mitochondrial apoptotic pathway.

【 授权许可】

Unknown