Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
Department of Emergency ICU, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, People's Republic of China.
J Cell Physiol. 2019 Dec;234(12):22034-22043. doi: 10.1002/jcp.28766. Epub 2019 May 9.
MicroRNA (miR) plays an integral role in cardiovascular diseases. M-iR-423-5p is aberrantly expressed in patients with myocardial infarction and heart failure. The aim of the present study was to study the roles and mechanisms of miR-423-5p in hypoxia/reoxygenation (H/R) mediated cardiomyocytes injury. H9C2 cells were transfected with negative control, miR-423-5p mimic, and inhibitor for 48 hr, followed by exposed to H/R condition. Cell apoptosis rate, caspase 3/7 activities, Bax and cleaved-caspase 3 (c-caspase 3) protein levels were assayed by flow cytometry, Caspase-Glo 3/7 Assay kit, western blot analysis, respectively. Furthermore, the mitochondrial membrane potential, adenosine triphosphate (ATP) content, reactive oxygen species (ROS) production, and Drp1 expression were also investigated. Furthermore, the dual-luciferase reporter assay was used to evaluate the relationship between miR-423-5p and Myb-related protein B (MYBL2). The roles of miR-423-5p in wnt/β-catenin were assessed by western blot analysis. The results revealed that H/R triggered miR-423-5p expression. Overexpression of miR-423-5p promoted cardiomyocyte apoptosis, enhanced the activities of caspase 3/7, upregulated the expression of Bax and c-caspase 3. miR-423-5p upregulation caused the loss of mitochondrial membrane potential and the reduction of ATP content, the augment of ROS production and Drp1 expression. However, the opposite trends were observed upon suppression of miR-423-5p. In addition, miR-423-5p could target the 3' untranslated region of MYBL2. miR-423-5p depletion led to the activation of the wnt/β-catenin signaling pathway via targeting MYBL2. Knockdown of MYBL2 was obviously reversed the roles of miR-423-5p in apoptosis and mitochondrial dysfunction. Taken together, miR-423-5p suppression reduced H/R-induced cardiomyocytes injury through activation of the wnt/β-catenin signaling pathway via targeting MYBL2 in cardiomyocytes.
微小 RNA（miR）在心血管疾病中起着重要作用。M-iR-423-5p 在心肌梗死和心力衰竭患者中表达异常。本研究旨在研究 miR-423-5p 在缺氧/复氧（H/R）介导的心肌细胞损伤中的作用和机制。将阴性对照、miR-423-5p 模拟物和抑制剂转染 H9C2 细胞 48 小时，然后暴露于 H/R 条件下。通过流式细胞术、Caspase-Glo 3/7 测定试剂盒和 Western blot 分析分别测定细胞凋亡率、半胱天冬酶 3/7 活性、Bax 和 cleaved-caspase 3（c-caspase 3）蛋白水平。此外，还研究了线粒体膜电位、三磷酸腺苷（ATP）含量、活性氧（ROS）产生和 Drp1 表达。此外，还使用双荧光素酶报告基因检测评估了 miR-423-5p 与 Myb 相关蛋白 B（MYBL2）之间的关系。通过 Western blot 分析评估了 miR-423-5p 在 wnt/β-catenin 中的作用。结果表明，H/R 触发了 miR-423-5p 的表达。miR-423-5p 的过表达促进心肌细胞凋亡，增强半胱天冬酶 3/7 的活性，上调 Bax 和 c-caspase 3 的表达。miR-423-5p 的上调导致线粒体膜电位丧失和 ATP 含量减少，ROS 产生和 Drp1 表达增加。然而，抑制 miR-423-5p 时则观察到相反的趋势。此外，miR-423-5p 可以靶向 MYBL2 的 3'非翻译区。miR-423-5p 耗竭通过靶向 MYBL2 激活 wnt/β-catenin 信号通路。MYBL2 的敲低明显逆转了 miR-423-5p 在凋亡和线粒体功能障碍中的作用。总之，miR-423-5p 的抑制通过靶向 MYBL2 减少 H/R 诱导的心肌细胞损伤，从而激活 wnt/β-catenin 信号通路。
