Lv Zhou, Wang Yan, Liu Yu-Jian, Mao Yan-Fei, Dong Wen-Wen, Ding Zhong-Nuo, Meng Guang-Xun, Jiang Lai, Zhu Xiao-Yan
Department of Anesthesiology and Surgical Intensive Care Unit, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
The Key Laboratory of Exercise and Health Sciences of Ministry of Education, School of Kinesiology, Shanghai University of Sport, Shanghai, China.
Crit Care Med. 2018 Jan;46(1):e49-e58. doi: 10.1097/CCM.0000000000002799.
Mechanical ventilation can induce lung fibrosis. This study aimed to investigate whether ventilator-induced lung fibrosis was associated with endothelial-mesenchymal transition and to uncover the underlying mechanisms.
Randomized, controlled animal study and cell culture study.
University research laboratory.
Adult male Institute of Cancer Research, NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) knockout and wild-type mice. Primary cultured mouse lung vascular endothelial cells.
Institute of Cancer Research, NLRP3 knockout and wild-type mice were subjected to mechanical ventilation (20 mL/kg) for 2 hours. Mouse lung vascular endothelial cells were subjected to cyclic stretch for 24 hours.
Mice subjected to mechanical ventilation exhibited increases in collagen deposition, hydroxyproline and type I collagen contents, and transforming growth factor-β1 in lung tissues. Ventilation-induced lung fibrosis was associated with increased expression of mesenchymal markers (α smooth muscle actin and vimentin), as well as decreased expression of endothelial markers (vascular endothelial-cadherin and CD31). Double immunofluorescence staining showed the colocalization of CD31/α smooth muscle actin, CD31/vimentin, and CD31/fibroblast-specific protein-1 in lung tissues, indicating endothelial-mesenchymal transition formation. Mechanical ventilation also induced NLRP3 inflammasome activation in lung tissues. In vitro direct mechanical stretch of primary mouse lung vascular endothelial cells resulted in similar NLRP3 activation and endothelial-mesenchymal transition formation, which were prevented by NLRP3 knockdown. Furthermore, mechanical stretch-induced endothelial-mesenchymal transition and pulmonary fibrosis were ameliorated in NLRP3-deficient mice as compared to wild-type littermates.
Mechanical stretch may promote endothelial-mesenchymal transition and pulmonary fibrosis through a NLRP3-dependent pathway. The inhibition of endothelial-mesenchymal transition by NLRP3 inactivation may be a viable therapeutic strategy against pulmonary fibrosis associated with mechanical ventilation.
机械通气可诱发肺纤维化。本研究旨在探讨机械通气诱导的肺纤维化是否与内皮-间充质转化相关，并揭示其潜在机制。
随机对照动物研究和细胞培养研究。
大学研究实验室。
成年雄性癌症研究所含NACHT、LRR和PYD结构域蛋白3（NLRP3）基因敲除小鼠和野生型小鼠。原代培养的小鼠肺血管内皮细胞。
癌症研究所NLRP3基因敲除小鼠和野生型小鼠接受2小时的机械通气（20毫升/千克）。小鼠肺血管内皮细胞接受24小时的周期性拉伸。
接受机械通气的小鼠肺组织中胶原沉积、羟脯氨酸和I型胶原含量以及转化生长因子-β1增加。通气诱导的肺纤维化与间充质标志物（α平滑肌肌动蛋白和波形蛋白）表达增加以及内皮标志物（血管内皮钙黏蛋白和CD31）表达降低相关。双重免疫荧光染色显示肺组织中CD31/α平滑肌肌动蛋白、CD31/波形蛋白和CD31/成纤维细胞特异性蛋白-1共定位，表明形成了内皮-间充质转化。机械通气还诱导肺组织中NLRP3炎性小体活化。体外对原代小鼠肺血管内皮细胞进行直接机械拉伸导致类似的NLRP3活化和内皮-间充质转化形成，而NLRP3基因敲低可阻止这种情况。此外，与野生型同窝小鼠相比，NLRP3缺陷小鼠中机械拉伸诱导的内皮-间充质转化和肺纤维化得到改善。
机械拉伸可能通过NLRP3依赖途径促进内皮-间充质转化和肺纤维化。通过NLRP3失活抑制内皮-间充质转化可能是对抗与机械通气相关的肺纤维化的一种可行治疗策略。
