Objective: To investigate the intervention effects and mechanism of interleukin-17A (IL-17A) on chronic obstructive pulmonary disease (COPD). Methods: C57BL/6 mice were randomly divided into wild type blank control group, wild type COPD group and IL-7A knockout COPD group. Mice in wild type blank control group received no treatment, and mice in the other two groups were exposed to cigarette smoke to induce COPD (Cigarette: 1 cigarette / time, 4 times/day, 45 minutes/time; interval time: 1 hour; total intervention time: 90 days). Lung function of mice was assessed using animal pulmonary function machine. Bronchoalveolar lavage fluid (BALF) of mice was collected and BALF cell count and classification were determined. The lung tissue of mice was collected, the expression level of IL-17A in airway epithelium was determined by flow cytometry, and the levels of inflammatory factors in lung tissue were determined by enzyme-linked immunosorbent assay. The expression level of JNK/AP1 signaling pathway protein in mouse lung tissue was determined by Western blot. Results: Compared with the wild type blank control group mice, the wild type COPD group mice had significantly higher expression level of IL-17A, significantly lower peak inspiratory flow rate (PIF) and peak expiratory flow rate (PEF), significantly higher number of BALF neutrophils, eosinophils, lymphocytes and macrophage, significantly higher expression levels of CXC chemokine 1(CXCL1), CXC chemokine 2 (CXCL2), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and significantly higher phosphorylation level of JNK, cJun and cFos and AP1 expression levels (P＜0.05). Compared with COPD mice, IL-17A expression level in airway epithelium of mice in IL-7A knockout COPD group was significantly lower, PIF and PEF were higher, the number of BALF neutrophils, eosinophils, lymphocytes and macrophage was significantly lower, the expression levels of CXCL1, CXCL2, IL-1β and IL-6 in lung tissue were lower, and the phosphorylation levels of JNK, cJun and cFos and AP1 expression levels were significantly lower (P＜0.05). Conclusion: Cigarette smoke can induce the production of IL-17A and reduce (or inhibit) the production (or expression or secretion) of IL-17A in mouse airway epithelium, thus inhibiting the JNK/AP1 signaling pathway to reduce the airway inflammation and improve the lung function of COPD mice.
目的:探讨白细胞介素-17A(IL-17A)对慢性阻塞性肺疾病(COPD)的干预作用及其机制。方法:C57BL/6小鼠随机分为野生型空白对照组、野生型COPD组和IL-7A敲除COPD组,每组20只。野生型空白对照组小鼠不做任何处理,其余两组小鼠暴露于香烟烟雾(1支/次,4次/日,每次45 min,每次间隔时间为1 h,总干预时间为90 d)制作COPD模型。干预结束24 h后,利用动物肺功能检测系统测定小鼠肺功能。收集小鼠支气管肺泡灌洗液(BALF),测定BALF细胞计数和分类。收集小鼠肺组织,采用流式细胞法测定气道上皮IL-17A表达水平,采用酶联免疫吸附法测定肺组织炎症因子水平。采用蛋白免疫印迹法测定小鼠肺组织JNK/AP1信号通路蛋白表达水平。结果:与野生型空白对照组小鼠比较,野生型COPD组小鼠气道上皮IL-17A表达水平明显升高,吸气峰流速(PIF)和呼气峰流速(PEF)明显降低,BALF中性粒细胞、嗜酸性粒细胞、淋巴细胞和巨噬细胞数明显升高,肺组织CXC类趋化因子1(CXCL1)、CXC类趋化因子2(CXCL2)、白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)表达水平明显升高,JNK、cJun和cFos磷酸化水平及AP1表达水平明显升高(P＜0.05);与野生型COPD组小鼠比较,IL-7A敲除COPD组小鼠气道上皮IL-17A表达水平明显降低,PIF和PEF明显升高,BALF中性粒细胞、嗜酸性粒细胞、淋巴细胞和巨噬细胞数明显降低,肺组织CXCL1、CXCL2、IL-1β和IL-6表达水平明显降低,JNK、cJun和cFos磷酸化水平及AP1表达水平明显降低(P＜0.05)。结论:香烟烟雾可诱导小鼠气道上皮产生IL-17A,降低(或抑制)IL-17A的产生(或表达或分泌),通过抑制JNK/AP1信号通路,减轻COPD气道炎症反应,改善COPD小鼠肺功能。.
Keywords: JNK/AP1 signal pathway; airway epithelium; airway inflammation; chronic obstructive pulmonary disease; cigarette smoke; interleukin-17A; mice.