Liu Xiling, Su Shanshan, Xia Lijing, Lei Xiong, Zou Shangpu, Zhou Liwen, Yang Ruobing, Li Kai, Lin Pengcheng, Li Yuping
The Key Laboratory of Interventional Pulmonology of Zhejiang Province, Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325015, People's Republic of China.
Emergency Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325015, People's Republic of China.
J Inflamm Res. 2024 Dec 6;17:10533-10546. doi: 10.2147/JIR.S495227. eCollection 2024.
Acute lung injury (ALI) is characterized by diffuse alveolar injury and acute non-cardiac pulmonary edema, with high morbidity and mortality. Lysophosphatidylcholine 14:0 (LPC14:0) has anti-inflammatory and anti-oxidative effects in sepsis and bacteremia. We hypothesized that LPC14:0 could be a potential treatment for ALI. Therefore, the effects of LPC14:0 on lung epithelial cells and the underlying mechanism on ALI were investigated.
Lipopolysaccharide (LPS) was instilled intratracheally in vivo while the Murine Lung Epithelial-12 was stimulated by tert-butyl hydroperoxide (t-BHP) in vitro to induce the ALI model. In vivo, lung injury was evaluated by histopathological changes and pulmonary edema was assessed by wet/dry ratio. Evans blue infiltration in lung tissue, total protein content, total cell counts and inflammatory factors in bronchoalveolar lavage fluid were evaluated for alveolar permeability. In vitro, cell viability and cell death rate were assessed by cell counting kit-8 and Calcein-AM/PI stain respectively. The expression of ZO-1, Occludin, Nrf2, and HO-1 was evaluated by Western blot.
LPC14:0 attenuated the LPS-stimulated lung injury and oxidative stress in vivo, and alleviated the t-BHP-induced cell damage in vitro. Moreover, LPC14:0 significantly inhibited the degradation of the tight junction proteins and activated the Nrf2/HO-1 signaling pathway both in vivo and in vitro. Mechanistically, ML385, the Nrf2 inhibitor, inhibited the protective effects of LPC14:0 on barrier function in vitro.
This study first demonstrated that LPC14:0 mitigated LPS-induced ALI and the destruction of tight junctions, at least in part through up-regulation of the Nrf2/HO-1 pathway.
急性肺损伤（ALI）的特征为弥漫性肺泡损伤和急性非心源性肺水肿，发病率和死亡率较高。溶血磷脂酰胆碱14:0（LPC14:0）在脓毒症和菌血症中具有抗炎和抗氧化作用。我们推测LPC14:0可能是ALI的一种潜在治疗方法。因此，研究了LPC14:0对肺上皮细胞的影响及其对ALI的潜在作用机制。
在体内通过气管内滴注脂多糖（LPS），同时在体外使用叔丁基过氧化氢（t-BHP）刺激小鼠肺上皮细胞-12（MLE-12）以诱导ALI模型。在体内，通过组织病理学变化评估肺损伤，通过湿/干比评估肺水肿。评估肺组织中伊文思蓝浸润、支气管肺泡灌洗液中的总蛋白含量、总细胞计数和炎性因子以评估肺泡通透性。在体外，分别通过细胞计数试剂盒-8（CCK-8）和钙黄绿素-AM/碘化丙啶（Calcein-AM/PI）染色评估细胞活力和细胞死亡率。通过蛋白质免疫印迹法评估紧密连接蛋白1（ZO-1）、闭合蛋白（Occludin）、核因子E2相关因子2（Nrf2）和血红素加氧酶-1（HO-1）的表达。
LPC14:0减轻了体内LPS刺激的肺损伤和氧化应激，并减轻了体外t-BHP诱导的细胞损伤。此外，LPC14:0在体内和体外均显著抑制紧密连接蛋白的降解并激活Nrf2/HO-1信号通路。机制上，Nrf2抑制剂ML385抑制了LPC14:0对体外屏障功能的保护作用。
本研究首次证明LPC14:0减轻了LPS诱导的ALI以及紧密连接的破坏，至少部分是通过上调Nrf2/HO-1途径实现的。
