Han Ying, Cai Xiaoqi, Pan Min, Gong Jin, Cai Wenqin, Lu Dan, Xu Changsheng
Department of Geriatrics, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China.
Fujian Institute of Hypertension, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China.
Exp Ther Med. 2022 Mar;23(3):230. doi: 10.3892/etm.2022.11154. Epub 2022 Jan 18.
MicroRNAs (miRNAs or miRs) play important roles in cardiovascular disease. miR-21-5p is known to be involved in the regulation of cardiomyocyte injury under high glucose and high fat (HG-HF) conditions, but its mechanism of action remains unclear. In the present study, a cardiomyocyte cell line, H9c2, was treated with 33 mM glucose and 250 µM sodium palmitate for 24, 48, and 72 h to produce HG-HF injury. After treatment, miR-21-5p expression was detected by reverse transcription-quantitative PCR. A miR-21-5p mimic was then constructed and transfected into the cells and the potential molecular mechanism was investigated using Cell Counting Kit-8, TUNEL, flow cytometry and western blot assays. Expression of miR-21-5p was significantly downregulated by HG-HF treatment of H9c2 cells for 24, 48, and 72 h. In subsequent experiments, cells were treated for an intermediate period (48 h). Compared with the control group, HG-HF treatment significantly inhibited H9c2 proliferation and promoted apoptosis, while these effects were significantly reduced in the miR-21-5p mimic. Compared with the control group, HG-HF treatment significantly increased reactive oxygen species, while miR-21-5p mimic significantly reduced this effect. Compared with the control group, HG-HF treatment significantly increased the expression of the pro-apoptotic proteins Bax and phosphorylated (p)-Akt and decreased the expression of the anti-apoptotic proteins Bcl-2, p-PTEN, and p-FOXO3a, while overexpression of miR-21-5p significantly reduced these effects. The results revealed that miR-21-5p inhibited apoptosis and oxidative stress in H9c2 cells induced by HG-HF, likely through the PTEN/Akt/FOXO3a signaling pathway.
微小RNA（miRNA或miR）在心血管疾病中发挥着重要作用。已知miR-21-5p参与高糖高脂（HG-HF）条件下心肌细胞损伤的调节，但其作用机制仍不清楚。在本研究中，用33 mM葡萄糖和250 µM棕榈酸钠处理心肌细胞系H9c2 24、48和72小时，以产生HG-HF损伤。处理后，通过逆转录定量PCR检测miR-21-5p的表达。然后构建miR-21-5p模拟物并转染到细胞中，并使用细胞计数试剂盒-8、TUNEL、流式细胞术和蛋白质印迹分析研究潜在的分子机制。HG-HF处理H9c2细胞24、48和72小时后，miR-21-5p的表达显著下调。在随后的实验中，细胞处理中间期（48小时）。与对照组相比，HG-HF处理显著抑制H9c2增殖并促进凋亡，而这些作用在miR-21-5p模拟物中显著降低。与对照组相比，HG-HF处理显著增加活性氧水平，而miR-21-5p模拟物显著降低这种作用。与对照组相比，HG-HF处理显著增加促凋亡蛋白Bax和磷酸化（p）-Akt的表达，并降低抗凋亡蛋白Bcl-2、p-PTEN和p-FOXO3a的表达，而miR-21-5p的过表达显著降低这些作用。结果表明，miR-21-5p可能通过PTEN/Akt/FOXO3a信号通路抑制HG-HF诱导的H9c2细胞凋亡和氧化应激。
