Pan Pan, Su Longxiang, Wang Xiaoting, Chai Wenzhao, Liu Dawei, Song Licheng, Xie Lixin
College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China.
Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Disease, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
Ann Transl Med. 2021 Feb;9(4):304. doi: 10.21037/atm-20-5129.
The activation and assembly of the NLRP3 inflammasome is dependent on the interaction between NLRP3 and the intermediate filament protein vimentin in an acute respiratory distress syndrome (ARDS) model. We investigated the role of vimentin in this process using human fetal lung (HFL-1) fibroblasts with vimentin transfer genes or gene knockdown and lipopolysaccharide (LPS) intervention.
HFL-1 cells [con-vector + LPS, vimentin-pCMV3 (VIM-pCMV3), con-siRNA, and vimentin siRNA (VIM-siRNA)] were treated with LPS. An oxidative stress damage assessment, apoptosis analysis, and quantification of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-10 by enzyme linked immunosorbent assay (ELISA) were performed. Immunoblotting was used to reveal the autophagy pathway.
We demonstrated that in response to LPS vimentin expression was lower in the HFL-1 cells with the vimentin gene knocked down. Specifically, an increase in oxidative stress, a decrease in mitochondrial membrane potential, or an increase in calcium ion permeability resulted in an increase in the fibroblast apoptosis rate. In addition, the inflammatory response after vimentin gene knockout was upregulated, as indicated by higher levels of TNF-a, IL-1β, IL-6, and IL-10. Importantly, the mechanism of suppression of vimentin in the lung fibroblasts was caused by a decrease in autophagy, an increase in mitochondrial membrane protein, and a decrease in mitochondrial function, which may contribute to the augmented cellular injury generated during the response to LPS.
This study provides insights into whether vimentin may interfere with the inflammatory cascade by activating the autophagy pathway of mitochondrial lung fibroblasts in the early stage of acute lung injury (ALI).
在急性呼吸窘迫综合征（ARDS）模型中，NLRP3炎性小体的激活和组装依赖于NLRP3与中间丝蛋白波形蛋白之间的相互作用。我们使用具有波形蛋白转移基因或基因敲低的人胎儿肺（HFL-1）成纤维细胞以及脂多糖（LPS）干预，研究了波形蛋白在此过程中的作用。
用LPS处理HFL-1细胞[对照载体+LPS、波形蛋白-pCMV3（VIM-pCMV3）、对照小干扰RNA、波形蛋白小干扰RNA（VIM-siRNA）]。进行氧化应激损伤评估、凋亡分析，并通过酶联免疫吸附测定（ELISA）对肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1β、IL-6和IL-10进行定量。采用免疫印迹法揭示自噬途径。
我们证明，在LPS刺激下，波形蛋白基因敲低的HFL-1细胞中波形蛋白表达较低。具体而言，氧化应激增加、线粒体膜电位降低或钙离子通透性增加导致成纤维细胞凋亡率升高。此外，波形蛋白基因敲除后的炎症反应上调，表现为TNF-α、IL-1β、IL-6和IL-10水平升高。重要的是，肺成纤维细胞中波形蛋白受抑制的机制是自噬减少、线粒体膜蛋白增加和线粒体功能降低，这可能导致在对LPS反应期间产生的细胞损伤加剧。
本研究探讨了波形蛋白是否可能在急性肺损伤（ALI）早期通过激活线粒体肺成纤维细胞的自噬途径来干扰炎症级联反应。
