Li Xiaoli, Zhong Jiuchang, Zeng Zhen, Wang Hongjiang, Li Jing, Liu Xiaoyan, Yang Xinchun
Department of Cardiology, Chaoyang Hospital affiliated to Capital Medical University, Heart Center & Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital Affiliated to Capital Medical University, Beijing, China.
Geriatric Department, Chui Yang Liu Hospital Affiliated to Tsinghua University, Beijing, China.
Cardiovasc Diagn Ther. 2020 Aug;10(4):849-858. doi: 10.21037/cdt-20-490.
Cardiomyocyte apoptosis plays an important role in the development of heart failure, which leads to high mortality in patients with cardiovascular diseases. In this study, we are focused to identify the role of miRNA-181c in the regulating of myocardial tissue apoptosis in the doxorubicin (DOX) or hypoxia/reoxygenation (H/R) induced H9C2 cardiomyocyte injury.
DOX-induced heart failure animal model was established using mice. Total RNA was extracted from tissue and cell using Trizol. RT-PCR was conducted for real-time RNA quantification. H9c2 cells were collected and labeled using an Annexin V-PI apoptosis kit. Flow cytometry was conducted to identify the cell apoptosis. Rat cardiomyocyte H9c2 cell was treated by 16 hours' hypoxia and 2 hours' reoxygenation to induce cell apoptosis. TUNEL assay was employed for myocardial tissue apoptosis analysis.
It was revealed that miR-181c was suppressed on the heart tissue of DOX-induced heart failure animal model. We observed miR-181c overexpression reduced apoptosis through TUNEL assay, which suggested the inhibitory effect of miR-181c on myocardial tissue apoptosis. Transfection of miR-181c mimic could decrease cell apoptosis in H/R treated H9C2 cells . Under the stimulation of H/R or DOX, miR-181c could downregulate protein expression of Fas, IL-6 and TNF-α, and upregulated Bcl2 and the phosphorylation of Akt.
Our study revealed that miR-181c protected heart failure by impeding cardiomyocyte apoptosis through PI3K/Akt pathway, implying the therapeutic role of miR-181c during the exacerbation of the cardiovascular disease.
心肌细胞凋亡在心力衰竭的发展过程中起着重要作用，这导致心血管疾病患者的高死亡率。在本研究中，我们致力于确定miRNA-181c在阿霉素（DOX）或缺氧/复氧（H/R）诱导的H9C2心肌细胞损伤中调节心肌组织凋亡的作用。
使用小鼠建立DOX诱导的心力衰竭动物模型。用Trizol从组织和细胞中提取总RNA。进行RT-PCR以进行实时RNA定量。收集H9c2细胞并用Annexin V-PI凋亡试剂盒进行标记。进行流式细胞术以鉴定细胞凋亡。用16小时缺氧和2小时复氧处理大鼠心肌细胞H9c2以诱导细胞凋亡。采用TUNEL法进行心肌组织凋亡分析。
结果显示，miR-181c在DOX诱导的心力衰竭动物模型的心脏组织中受到抑制。通过TUNEL分析，我们观察到miR-181c过表达减少了凋亡，这表明miR-181c对心肌组织凋亡具有抑制作用。转染miR-181c模拟物可减少H/R处理的H9C2细胞中的细胞凋亡。在H/R或DOX刺激下，miR-181c可下调Fas、IL-6和TNF-α的蛋白表达，并上调Bcl2和Akt的磷酸化。
我们的研究表明，miR-181c通过PI3K/Akt途径阻止心肌细胞凋亡来保护心力衰竭，这意味着miR-181c在心血管疾病加重期间具有治疗作用。
