Lin Ling, Song Qing, Cheng Wei, Liu Cong, Zhou Aiyuan, Zhou Zijing, Chen Ping
Department of Respiratory and Critical Care Medicine, the Second Xiangya Hospital, Central South University, Changsha, China.
Research Unit of Respiratory Disease, Central South University, Changsha, China.
Tob Induc Dis. 2023 Oct 10;21:130. doi: 10.18332/tid/171357. eCollection 2023.
Abnormal apoptosis of pulmonary microvascular endothelial cells (PMVECs) participates in the pathogenesis of COPD. Studies have shown that microRNAs (miRNAs) contribute to the pathogenesis of pulmonary diseases by regulating cell apoptosis. The present study aimed to investigate the effects of miR-216a in cigarette smoke extract (CSE)-induced apoptosis of PMVECs in COPD and explore the potential mechanisms.
The emphysema model mice were treated with CSE and CS exposure. The expression of miR-216a and DNA methyltransferase 1 (DNMT1) was assessed in emphysema mice and COPD patients. The miR-216a mimic and Lenti-DNMT1 were transfected into PMVECs to identify the underlying mechanisms. The expression levels of miR-216a and DNMT1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR) or Western blot. Moreover, cell apoptosis was examined by flow cytometry assays.
The results show that the expression of miR-216a was decreased, whereas the expression of DNMT1 was increased in the lung tissue of emphysema mice and COPD patients. In addition, the expression of miR-216a was significantly reduced in CSE-treated PMVECs, and the overexpression of miR-216a attenuated CSE-induced PMVEC apoptosis. Furthermore, the expression of DNMT1 was increased in the CSE-induced PMVECs and then was reduced after the overexpression of miR-216a in the CSE-stimulated PMVECs. Luciferase reporter assays confirmed the target reaction between miR-216a and DNMT1. Also, the overexpression of DNMT1 was able to reverse the anti-apoptotic effect of miR-216a in CSE-induced PMVECs.
The results indicate that miR-216a may play a crucial role in CSE-induced apoptosis by directly regulating its target gene DNMT1 in COPD. It provides insights into the function of MiR-216a/DNMT1 as a potential molecule in COPD.
肺微血管内皮细胞（PMVECs）的异常凋亡参与慢性阻塞性肺疾病（COPD）的发病机制。研究表明，微小RNA（miRNAs）通过调节细胞凋亡参与肺部疾病的发病机制。本研究旨在探讨miR-216a在香烟烟雾提取物（CSE）诱导的COPD患者肺微血管内皮细胞凋亡中的作用，并探索其潜在机制。
用CSE和香烟烟雾暴露处理肺气肿模型小鼠。评估肺气肿小鼠和COPD患者中miR-216a和DNA甲基转移酶1（DNMT1）的表达。将miR-216a模拟物和慢病毒-DNMT1转染到肺微血管内皮细胞中以确定潜在机制。通过实时定量聚合酶链反应（RT-qPCR）或蛋白质免疫印迹法检测miR-216a和DNMT1的表达水平。此外，通过流式细胞术检测细胞凋亡。
结果显示，肺气肿小鼠和COPD患者肺组织中miR-216a表达降低，而DNMT1表达增加。此外，CSE处理的肺微血管内皮细胞中miR-216a表达显著降低，miR-216a过表达减弱了CSE诱导的肺微血管内皮细胞凋亡。此外，CSE诱导的肺微血管内皮细胞中DNMT1表达增加，而在CSE刺激的肺微血管内皮细胞中miR-216a过表达后DNMT1表达降低。荧光素酶报告基因检测证实了miR-216a与DNMT1之间的靶向反应。此外，DNMT1过表达能够逆转miR-216a在CSE诱导的肺微血管内皮细胞中的抗凋亡作用。
结果表明，miR-216a可能通过直接调节其靶基因DNMT1在COPD的CSE诱导凋亡中起关键作用。它为MiR-216a/DNMT1作为COPD中潜在分子的功能提供了见解。
