Department of Geriatric Medicine, Maanshan People's Hospital, China.
Department of Clinical Laboratory, The Second Affiliated Hospital of Wannan Medical College, Wuhu, China.
Adv Clin Exp Med. 2024 Mar;33(3):261-272. doi: 10.17219/acem/168242.
Acute myocardial infarction (AMI) is a common cardiovascular disease worldwide. Circular RNAs (circRNAs) have been shown to exert essential roles in the progression of AMI. However, it remains unclear whether circANKIB1 protects cardiomyocytes from hypoxia-induced injury.
The aim of the study was to elucidate the function and mechanisms of circANKIB1 in AMI.
The expression of RNA was estimated using a quantitative real-time polymerase chain reaction (qPCR) assay, and the level of protein was determined with the use of western blot analysis. Methyl thiazolyl tetrazolium (MTT) assay was introduced to test cell viability, and a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used to detect apoptosis. The relative levels of ferrous ion (Fe2+), reactive oxygen species (ROS) and malondialdehyde (MDA) were measured with their corresponding detection kits. The potential target of circANKIB1 and miR-452-5p was predicted using the StarBase database and verified by employing a dual luciferase reporter assay.
This study showed a significant decrease in circANKIB1 in hypoxia-treated H9c2 cells. Hypoxic exposure significantly reduced the viability of H9c2 cells and the expression of GPX4, and increased the content of Fe2+, ROS and MDA. These effects were reversed by the overexpression of circANKIB1. Additionally, miR-452-5p was found to be a direct target of circANKIB1, and the miR-452-5p mimic significantly eliminated the protective effect of circANKIB1 overexpression in hypoxia-induced cells. In addition, miR-452-5p could bind to SLC7A11 and negatively regulate its expression. The knockdown of SLC7A11 abolished the effect of circANKIB1 overexpression on hypoxia-induced cardiomyocyte injury.
This investigation revealed for the first time that circANKIB1 regulated signaling of the miR-452-5p/SLC7A11 axis, thereby ameliorating hypoxia-induced cardiomyocyte injury. These findings suggest that circANKIB1 might be a useful adjunct in the treatment of AMI.
急性心肌梗死（AMI）是一种常见的心血管疾病，在全球范围内普遍存在。环状 RNA（circRNAs）已被证明在 AMI 的进展中发挥着重要作用。然而，circANKIB1 是否能保护心肌细胞免受缺氧诱导的损伤尚不清楚。
本研究旨在阐明 circANKIB1 在 AMI 中的作用和机制。
采用实时定量聚合酶链反应（qPCR）检测 RNA 的表达，采用 Western blot 分析检测蛋白水平。采用噻唑蓝（MTT）比色法检测细胞活力，采用末端脱氧核苷酸转移酶 dUTP 缺口末端标记（TUNEL）法检测细胞凋亡。采用相应的检测试剂盒测定二价铁离子（Fe2+）、活性氧（ROS）和丙二醛（MDA）的相对水平。利用 StarBase 数据库预测 circANKIB1 和 miR-452-5p 的潜在靶点，并通过双荧光素酶报告基因实验进行验证。
本研究显示，缺氧处理的 H9c2 细胞中 circANKIB1 的表达显著降低。缺氧暴露显著降低了 H9c2 细胞的活力和 GPX4 的表达，增加了 Fe2+、ROS 和 MDA 的含量。这些作用可被 circANKIB1 的过表达逆转。此外，miR-452-5p 被发现是 circANKIB1 的直接靶点，miR-452-5p 模拟物显著消除了 circANKIB1 过表达在缺氧诱导细胞中的保护作用。此外，miR-452-5p 可以与 SLC7A11 结合并负调控其表达。SLC7A11 的敲低消除了 circANKIB1 过表达对缺氧诱导的心肌细胞损伤的影响。
本研究首次揭示，circANKIB1 调节 miR-452-5p/SLC7A11 轴的信号，从而改善缺氧诱导的心肌细胞损伤。这些发现表明，circANKIB1 可能是 AMI 治疗的有用辅助手段。
