Li Qingman, Zhu Lijie, Niu Fangqing, Li Qingmin, Wang Che, Yang Honghui, Gao Chuanyu
Department of Cardiology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, 450003, P. R. China.
Department of Cardiology, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, 451464, P. R. China.
Cell Death Discov. 2021 Sep 15;7(1):240. doi: 10.1038/s41420-021-00601-1.
Histone deacetylases (HDACs) and microRNAs (miRs) have been reported to exert pivotal roles on the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). Therefore, the present study was performed to define the underlying role of HDAC4 and miR-206 in the pathological process of MIRI. An IRI rat model was established. The interaction between HDAC4 and the promoter region of miR-206 was determined using ChIP, and that between miR-206 and mitogen-activated protein kinase kinase kinase 1 (MEKK1) was determined using dual luciferase reporter gene assay. After the loss- or gain-of-function assay in cardiomyocytes, western blot analysis, RT-qPCR, TUNEL, and ELISA assay were performed to define the roles of HDAC4, miR-206, and MEKK1. Up-regulation of HDAC4 and down-regulation of miR-206 occurred in rat myocardial tissues and cardiomyocytes in MIRI. HDAC4 down-regulation or miR-206 up-regulation contributed to reduced cell apoptosis and the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and malondialdehyde (MDA), while elevating the superoxide dismutase (SOD) and glutathione (GSH) contents. Meanwhile, HDAC4 silencing promoted the expression of miR-206, which targeted and negatively regulated MEKK1. Then inhibition of JNK phosphorylation reduced the cardiomyocyte apoptosis to alleviate MIRI. Coherently, HDAC4 silencing could up-regulate the expression of miR-206 to reduce cardiomyocyte apoptosis and inhibit oxidative stress, and exerting a protective effect on MIRI via the MEKK1/JNK pathway.
据报道，组蛋白去乙酰化酶（HDACs）和微小RNA（miRs）在心肌缺血再灌注损伤（MIRI）的发病机制中发挥关键作用。因此，本研究旨在确定HDAC4和miR-206在MIRI病理过程中的潜在作用。建立了IRI大鼠模型。采用染色质免疫沉淀法（ChIP）确定HDAC4与miR-206启动子区域之间的相互作用，采用双荧光素酶报告基因测定法确定miR-206与丝裂原活化蛋白激酶激酶激酶1（MEKK1）之间的相互作用。在心肌细胞进行功能缺失或功能获得实验后，进行蛋白质免疫印迹分析、逆转录定量聚合酶链反应（RT-qPCR）、末端脱氧核苷酸转移酶介导的缺口末端标记法（TUNEL）和酶联免疫吸附测定（ELISA），以确定HDAC4、miR-206和MEKK1的作用。在MIRI的大鼠心肌组织和心肌细胞中，HDAC4上调而miR-206下调。HDAC4下调或miR-206上调有助于减少细胞凋亡以及肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）和丙二醛（MDA）水平，同时提高超氧化物歧化酶（SOD）和谷胱甘肽（GSH）含量。同时，HDAC4沉默促进了miR-206的表达，miR-206靶向并负向调节MEKK1。然后抑制JNK磷酸化可减少心肌细胞凋亡，减轻MIRI。连贯地，HDAC4沉默可上调miR-206的表达，减少心肌细胞凋亡并抑制氧化应激，并通过MEKK1/JNK途径对MIRI发挥保护作用。
