白介素17对急性肺损伤时肺水肿液清除的影响

目的 探讨白介素17(IL-17)对急性肺损伤(ALI)小鼠肺水清除的影响及可能机制.方法 IL-17基因敲除鼠和野生型C57BL/6鼠各16只,随机各等分为两组(一共4组,每组8只),分别经气道给与磷酸缓冲盐溶液和脂多糖(LPS)干预,给药48 h后处死.比较各组肺湿干质量比(W/D)、支气管肺泡灌洗液中白介素8(IL-8)水平和肺组织钠通道(ENaC)蛋白表达情况.并采用HE染色观察肺组织病理改变,免疫组化法了解肝激酶B1(LKB1)表达差异.结果 与接受LPS干预的野生型鼠比较,IL-17敲除型鼠在接受LPS处理后W/D由9.739±3.3降至5.351±0.56,IL-8由67.50±7.33 pg/mL降至41.00±3.16 pg/mL,差异有统计学意义.病检结果提示IL-17敲除型鼠肺泡腔内水肿液聚集减少,肺损伤评分显著降低.Western blotting和免疫组化结果示接受LPS刺激的IL-17敲除型鼠ENaC表达更多,LKB1丢失相对较少.结论 敲除IL-17不仅可以减轻ALI小鼠肺组织炎症程度,还可以减少ENaC蛋白丢失,促进肺水清除,其保护作用可能与LKB1有关.

Role of interleukin-17 in alveolar fluid clearance in mice with acute lung injury

Objective To investigate the role of interleukin-17 (IL-17) in alveolar fluid clearance in mice with acute lung injury (ALI) and explore the possible mechanism. Methods Sixteen IL-17-knockout mice and 16 wild-type mice were both randomized for intratracheal instillation of PBS (control) on lipopolysaccharide (LPS) to induce ALI. Forty-eight hours after the treatments, the wet-dry ratio (W/D) of the lungs, IL-8 in the bronchoalveolar lavage fluid (BALF) and histopathological changes of the lung tissues were examined. The expressions of epithelial sodium channel α subunit (α-ENaC) was detected with Western blotting and liver kinase B1 (LKB1) was detected with immunohistochemistry. Results Compared with wild-type mice treated with LPS, IL-17 knockout mice showed significantly decreased W/D of the lungs (9.739±3.3 vs 5.351±0.56) and IL-8 level in the BALF (67.50 ± 7.33 vs 41.00 ± 3.16 pg/mL) following LPS challenge. Pathological examination revealed reduced alveolar edema fluid aggregations and lower lung injury score in IL-17 knockout mice with also higher expression levels of ENaC and LKB1 compared with the wild-type mice. Conclusion Knocking out IL-17 in mice not only alleviates inflammation of the lung tissue following ALI but also reduces the loss of ENaC protein and promotes alveolar fluid clearance, mechanism of which is probably associated with LKB1.