Zhang Qiufeng, Wu Xiaotian, Yang Jie
Emergency Department, First People's Hospital of Shangqiu City, Shangqiu, China.
Department of Cardiovascular Medicine, Xiaoshan Hospital, Xiaoshan, China.
Ann Transl Med. 2021 Apr;9(8):654. doi: 10.21037/atm-21-807.
MicroRNA (miRNA), which participates in various physiological and pathological processes, is a highly conserved small RNA sequence. This study aimed to investigate the role of miR-194-5p in hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis and myocardial ischemia/reperfusion (I/R) injury.
We set up an H/R H9c2 cell model and an I/R mouse model . Then, cell vitality, apoptosis, and histopathological evaluation were conducted. Reactive oxygen species (ROS) generation and the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) were examined by 2',7'-Dichlorodihydrofluorescein diacetate (H2DCFDA), and enzyme-linked immunosorbent assay (ELISA), respectively. The level of creatine kinase isoenzyme (CK-MB), cardiac troponin I (cTnI), myoglobin (Mb) is examined by ELISA. The expression of Caspase-3, cleaved-Caspase-3, Bax, Bcl-2, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and protein kinase B (AKT) was analyzed by western blot.
Data showed the expression of miR-194-5p was decreased in H/R-induced H9c2 cells and I/R-induced mouse. Conversely, overexpression of miR-194-5p could improve cardiomyocyte damage in ischemic models and . Furthermore, mitogen-activated protein kinase 1 (MAPK1) was found as a direct target of miR-194-5p, which negatively regulated the expression of MAPK1. The up-regulation of MAPK1 inhibited the myocardial protection previously observed by miR-194-5p.
Our study shows overexpression of miR-194-5p protects against H/R injury and cardiac I/R injury , which involves the inhibition of cardiac apoptosis and oxidative stress by targeting MAPK1 expression via PTEN/AKT pathway. These findings supply novel insights into potential therapeutic targets for cardiovascular diseases.
微小RNA（miRNA）是一种高度保守的小RNA序列，参与多种生理和病理过程。本研究旨在探讨miR-194-5p在缺氧/复氧（H/R）诱导的心肌细胞凋亡及心肌缺血/再灌注（I/R）损伤中的作用。
我们建立了H/R H9c2细胞模型和I/R小鼠模型。然后，进行细胞活力、凋亡及组织病理学评估。分别采用2',7'-二氯二氢荧光素二乙酸酯（H2DCFDA）、酶联免疫吸附测定（ELISA）检测活性氧（ROS）生成、超氧化物歧化酶（SOD）和丙二醛（MDA）活性。通过ELISA检测肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白I（cTnI）、肌红蛋白（Mb）水平。采用蛋白质印迹法分析半胱天冬酶-3（Caspase-3）、裂解型半胱天冬酶-3（cleaved-Caspase-3）、Bax、Bcl-2、第10号染色体缺失的磷酸酶和张力蛋白同源物（PTEN）及蛋白激酶B（AKT）的表达。
数据显示，在H/R诱导的H9c2细胞和I/R诱导的小鼠中，miR-194-5p表达降低。相反，miR-194-5p过表达可改善缺血模型中的心肌细胞损伤。此外，发现丝裂原活化蛋白激酶1（MAPK1）是miR-194-5p的直接靶标，其负向调节MAPK1的表达。MAPK1的上调抑制了先前miR-194-5p观察到的心肌保护作用。
我们的研究表明，miR-194-5p过表达可保护心肌免受H/R损伤和心脏I/R损伤，这涉及通过PTEN/AKT途径靶向MAPK1表达来抑制心肌细胞凋亡和氧化应激。这些发现为心血管疾病潜在治疗靶点提供了新的见解。
