Ye Chunlin, Qi Wanghong, Dai Shaohua, Zou Guowen, Liu Weicheng, Yu Bentong, Tang Jian
Department of Thoracic Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, People's Republic of China.
Department of Anesthesiology, The First Affiliated Hospital of Nanchang University, Nanchang, People's Republic of China.
Am J Physiol Lung Cell Mol Physiol. 2020 Jul 1;319(1):L1-L10. doi: 10.1152/ajplung.00009.2020. Epub 2020 Apr 8.
Lung ischemia-reperfusion (I/R) injury severely endangers human health, and recent studies have suggested that certain microRNAs (miRNAs) play important roles in this pathological phenomenon. The current study aimed to ascertain the ability of miR-223 to influence lung I/R injury by targeting hypoxia-inducible factor-2α (HIF2α). First, mouse models of lung I/R injury were established: during surgical procedures, pulmonary arteries and veins and unilateral pulmonary portal vessels were blocked and resuming bilateral pulmonary ventilation, followed by restoration of bipulmonary ventilation. In addition, a lung I/R injury cell model was constructed by exposure to hypoxic reoxygenation (H/R) in mouse pulmonary microvascular endothelial cells (PMVECs). Expression of miR-223, HIF2α, and β-catenin in tissues or cells was determined by RT-qPCR and Western blot analysis. Correlation between miR-223 and HIF2α was analyzed by dual luciferase reporter gene assay. Furthermore, lung tissue injury and mouse PMVEC apoptosis was evaluated by hematoxylin and eosin (H&E), TUNEL staining, and flow cytometry. Autophagosomes in cells were detected by light chain 3 immunofluorescence assay. miR-223 was expressed at a high level while HIF2α/β-catenin was downregulated in tissues and cells with lung I/R injury. Furthermore, miR-223 targeted and repressed HIF2α expression to downregulate β-catenin expression. The miR-223/HIF2α/β-catenin axis aggravated H/R injury in mouse PMVECs and lung I/R injury in mice by enhancing autophagy. Taken together, miR-223 inhibits HIF2α to repress β-catenin, thus contributing to autophagy to complicate lung I/R injury. These findings provide a promising therapeutic target for treating lung I/R injury.
肺缺血再灌注（I/R）损伤严重危害人类健康，近期研究表明某些微小RNA（miRNA）在这一病理现象中发挥重要作用。本研究旨在确定miR-223通过靶向缺氧诱导因子-2α（HIF2α）影响肺I/R损伤的能力。首先，建立肺I/R损伤小鼠模型：在手术过程中，阻断肺动脉、肺静脉和单侧肺门血管，恢复双侧肺通气，随后恢复双肺通气。此外，通过在小鼠肺微血管内皮细胞（PMVECs）中进行缺氧复氧（H/R）构建肺I/R损伤细胞模型。通过RT-qPCR和蛋白质免疫印迹分析测定组织或细胞中miR-223、HIF2α和β-连环蛋白的表达。通过双荧光素酶报告基因测定分析miR-223与HIF2α之间的相关性。此外，通过苏木精-伊红（H&E）染色、TUNEL染色和流式细胞术评估肺组织损伤和小鼠PMVEC凋亡。通过轻链3免疫荧光测定检测细胞中的自噬体。在肺I/R损伤的组织和细胞中，miR-223高水平表达，而HIF2α/β-连环蛋白下调。此外，miR-223靶向并抑制HIF2α表达以下调β-连环蛋白表达。miR-223/HIF2α/β-连环蛋白轴通过增强自噬加重小鼠PMVECs中的H/R损伤和小鼠肺I/R损伤。综上所述，miR-223抑制HIF2α以抑制β-连环蛋白，从而促进自噬使肺I/R损伤复杂化。这些发现为治疗肺I/R损伤提供了一个有前景的治疗靶点。
