Zhou An-Qiang, Cao Ying, Song Ying-Nan, Zhang Ben-Fa, Chen Kai-Yuan, Yang Si-Yuan, Chen Hong-Jin
Division of Cardiac Surgery, Guizhou Institute of Precision Medicine, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, 550009, China; Translational Medicine Research Center, Guizhou Province Key Laboratory of Regenerative Medicine, Tissue Engineering and Stem Cell Experiment Center, Guizhou Medical University, GuiAn, 561113, Guizhou, China.
Department of Anesthesiology, The Affiliated JinYang Hospital of Guizhou Medical University, The Second People's Hospital of Guiyang, Guiyang, 550023, Guizhou, China.
Biochem Biophys Res Commun. 2025 Jul 1;768:151938. doi: 10.1016/j.bbrc.2025.151938. Epub 2025 May 2.
Improving myocardial energy metabolism is an important way to alleviate myocardial ischemia/reperfusion injury (MIRI). Myocardial insulin resistance (IR) can occur after MIRI and cause the inhibition of glucose absorption and metabolism. This study aimed to detect the mechanism of miR-92a-1-5p in MIRI-induced myocardial IR.
First, MIRI rat models were established using the Langendorff technique. H9c2 cells were treated with oxygen-glucose deprivation/reperfusion (OGD/R) to establish in vitro cell models. The expression levels of miR-92a-1-5p and myocyte enhancer factor 2A (MEF2A) were detected using RT-qPCR, and the expression of glucose transporter 4 (GLUT4) in the cell membrane and MEF2A was detected using Western blot. Immunofluorescence was used to detect GLUT4 expression in the cell membrane of H9c2 cells. Glucose absorption was detected in H9c2 cells using flow cytometry. H&E staining was used to determine pathological changes in heart tissue. H9c2 cell viability was detected using CCK-8 assay, and the binding affinity between miR-92a-1-5p and MEF2A was verified using dual luciferase reporter assay.
miR-92a-1-5p expression increased, and MEF2A expression decreased after OGD/R in H9c2 cells or MIRI in rats. Overexpression of miR-92a-1-5p aggravated myocardial tissue and H9c2 cell damage, inhibited the translocation of GLUT4 to the cell membrane, and reduced glucose absorption. Inhibiting the miR-92a-1-5p yielded the opposite results. MEF2A overexpression reversed the injury, which was exacerbated by miR-92a-1-5p, and promoted the translocation of GLUT4 to the cell membrane and glucose absorption. The double luciferase reporter assay results showed that miR-92a-1-5p could negatively regulate the expression of MEF2A.
miR-92a-1-5p expression increased after IR in myocardial tissue and H9c2 cells. Inhibition of miR-92a-1-5p increased MEF2A expression, promoted GLUT4 translocation, and increased glucose absorption, thereby reducing MIRI.
改善心肌能量代谢是减轻心肌缺血/再灌注损伤（MIRI）的重要途径。MIRI后可发生心肌胰岛素抵抗（IR），导致葡萄糖摄取和代谢受到抑制。本研究旨在探究miR-92a-1-5p在MIRI诱导的心肌IR中的作用机制。
首先，采用Langendorff技术建立MIRI大鼠模型。用氧糖剥夺/再灌注（OGD/R）处理H9c2细胞以建立体外细胞模型。采用RT-qPCR检测miR-92a-1-5p和肌细胞增强因子2A（MEF2A）的表达水平，采用蛋白质免疫印迹法检测细胞膜上葡萄糖转运蛋白4（GLUT4）和MEF2A的表达。利用免疫荧光检测H9c2细胞膜上GLUT4的表达。采用流式细胞术检测H9c2细胞的葡萄糖摄取。用苏木精-伊红（H&E）染色确定心脏组织的病理变化。采用CCK-8法检测H9c2细胞活力，利用双荧光素酶报告基因检测法验证miR-92a-1-5p与MEF2A之间的结合亲和力。
在H9c2细胞中进行OGD/R处理或在大鼠中造成MIRI后，miR-92a-1-5p表达增加，MEF2A表达降低。miR-92a-1-5p过表达加重心肌组织和H9c2细胞损伤，抑制GLUT4向细胞膜的转位，并降低葡萄糖摄取。抑制miR-92a-1-5p则产生相反的结果。MEF2A过表达可逆转由miR-92a-1-5p加剧的损伤，并促进GLUT4向细胞膜的转位及葡萄糖摄取。双荧光素酶报告基因检测结果表明，miR-92a-1-5p可负向调节MEF2A的表达。
心肌组织和H9c2细胞在IR后miR-92a-1-5p表达增加。抑制miR-92a-1-5p可增加MEF2A表达，促进GLUT4转位，增加葡萄糖摄取，从而减轻MIRI。
