Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.
J Cell Physiol. 2020 Sep;235(9):5985-5994. doi: 10.1002/jcp.29524. Epub 2020 Jan 24.
Myocardial ischemic preconditioning (IP) is defined as a brief period of myocardial ischemia/reperfusion (I/R) that significantly reduces injury during the subsequent exposure to long-term I/R. However, the underlying mechanisms of myocardial IP are yet to be elucidated. This study investigated the expression and roles of long noncoding RNA (lncRNA) H19 in myocardial IP in vitro and in vivo. LncRNA H19 expression levels were analyzed by quantitative reverse-transcription polymerase chain reaction, cell viability was determined by the Cell Counting Kit-8 assay, apoptosis was evaluated based on the caspase 3 activity, and RNA immunoprecipitation was performed to examine the interaction between lncRNA H19 and nucleolin. The results of this study showed that lncRNA H19 expression was significantly upregulated in mouse hearts subjected to myocardial IP, in rat H9C2 cells exposed to H O preconditioning (H O -PC), and in neonatal rat cardiomyocytes subjected to hypoxia preconditioning. H19 knockdown abrogated the H O -PC-mediated protection in cardiomyocytes evidenced by the decreased cell viability and increased caspase-3 activity. Conversely, H19 overexpression enhanced the protective role of H O -PC in cardiomyocytes. In addition, H19 overexpression increased the expression of nucleolin, whereas H19 ablation abrogated H O -PC-induced upregulation of nucleolin in cardiomyocytes. Furthermore, H19 overexpression increased the stabilization of nucleolin; an interaction between H19 and nucleolin was identified using the RNA-protein interaction studies. Furthermore, nucleolin small interfering RNA relieved the protective role of lncRNA H19. These findings demonstrated that the lncRNA H19 is involved in myocardial IP via increasing the stability of nucleolin protein and lncRNA H19 may represent a potential therapeutic target for the treatment of the myocardial injury.
心肌缺血预处理（IP）定义为短暂的心肌缺血/再灌注（I/R），可显著减少随后暴露于长期 I/R 中的损伤。然而，心肌 IP 的潜在机制尚未阐明。本研究在体外和体内研究了长链非编码 RNA（lncRNA）H19 在心肌 IP 中的表达和作用。通过定量逆转录聚合酶链反应分析 lncRNA H19 的表达水平，通过细胞计数试剂盒-8 测定细胞活力，根据 caspase 3 活性评估细胞凋亡，并进行 RNA 免疫沉淀以检测 lncRNA H19 和核仁蛋白之间的相互作用。本研究结果表明，在经历心肌 IP 的小鼠心脏、在接受 H 2 O 2 预处理（H 2 O 2 -PC）的大鼠 H9C2 细胞以及在经历低氧预处理的新生大鼠心肌细胞中，lncRNA H19 的表达显著上调。H19 敲低消除了 H 2 O 2 -PC 介导的心肌细胞保护作用，表现为细胞活力降低和 caspase-3 活性增加。相反，H19 过表达增强了 H 2 O 2 -PC 在心肌细胞中的保护作用。此外，H19 过表达增加了核仁蛋白的表达，而 H19 敲除消除了 H 2 O 2 -PC 诱导的心肌细胞中核仁蛋白的上调。此外，H19 过表达增加了核仁蛋白的稳定性；通过 RNA-蛋白质相互作用研究鉴定了 H19 与核仁蛋白之间的相互作用。此外，核仁蛋白小干扰 RNA 减轻了 lncRNA H19 的保护作用。这些发现表明，lncRNA H19 通过增加核仁蛋白的稳定性参与心肌 IP，并且 lncRNA H19 可能成为治疗心肌损伤的潜在治疗靶点。
