炎症相关趋化因子/细胞因子在香烟暴露和戒烟小鼠肺组织中的表达

目的 观察香烟暴露及戒烟后小鼠肺组织炎症以及炎症相关趋化因子及细胞因子表达的情况。方法 将18只雄性C57BL/6小鼠随机分为正常对照组、香烟暴露组及戒烟组3组,每组6只。测量小鼠气道阻力,HE和Masson染色观察肺部形态及炎症情况,计数支气管肺泡灌洗液(BALF)中炎症细胞总数及细胞分类数,采用实时PCR方法及免疫组织化学法检测各组小鼠肺组织中CXCL9、CXCL10、CXCL11、基质金属蛋白酶(MMP)2、MMP9、MMP12及转化生长因子-β1(TGF-β1)的mRNA及蛋白表达水平,采用酶联免疫吸附法测量BALF上清中CXCL9、CXCL10、CXCL11、白细胞介素(IL)-6、IL-8、肿瘤坏死因子-α(TNF-α)、TGF-β1水平。结果 香烟暴露组小鼠气道阻力(Rn)显著高于正常对照组(P＜0.01),戒烟组Rn亦显著高于正常组(P＜0.05)。与正常对照组比较,香烟暴露组与戒烟组肺组织病理总评分均显著增高(P＜0.001)。香烟暴露组和戒烟组的炎症细胞总数显著高于正常对照组(P＜0.001)。香烟暴露组和戒烟组CXCL9、CXCL10、MMP9和MMP12的 mRNA水平均显著高于正常对照组(P均＜0.05)。香烟暴露组和戒烟组CXCL9、CXCL10、CXCL11、MMP2、MMP9、MMP12及TGF-β1的蛋白表达水平均显著高于正常对照组(P均＜0.05)。与正常对照组比较,香烟暴露组和戒烟组BALF上清中的CXCL9、CXCL10、CXCL11、IL-8及TGF-β1浓度显著增加(P均＜0.05),香烟暴露组IL-6和TNF-α浓度亦显著升高(P均＜0.05)。结论 香烟暴露引起炎症细胞在肺组织中聚集及炎症细胞因子升高,戒烟后炎症细胞及炎症细胞因子尽管有所下降,但仍高于正常对照。戒烟后肺部炎症持续存在,趋化因子受体CXCR3的配体可能在其中发挥关键作用。

Differential Expression of the Inflammation-associated Chemokines/cytokines in Mouse Lung after Exposure to Cigarette Smoke and Smoking Cessation

Objective To determine the changes in the airway inflammation-related cytokine/chemokine profiles after exposure to cigarette smoke(CS)and smoking cessation(SC). Methods A total of 18 male C57BL/6 mice were equally divided into three groups:CS group,SC group,and normal control group. The airway resistance,lung morphology,and collagen deposition around airways were determined. HE staining and Masson trichrome staining were used for histopathological analysis. The inflammatory cells in bronchoalveolar lavage fluid(BALF)were assessed. The inflammation-associated cytokines were determined using real-time PCR and immunohistochemistry. Expressions of CXCR3 ligands including the CXCL9,CXCL10,CXCL11 and other cytokines in lung tissue and BALF were also analyzed. Results The airway resistance significantly increased in both CS group and SC group when compared with the normal control group. Lung pathological scores in both CS group and SC group were also higher than that in the normal control group,while there was no significant difference between the CS group and SC group. Inflammatory cells including the neutrophils,macrophages,and lymphocytes also increased in both the CS group and SC group at both mRNA and protein levels. The mRNA levels of CXCL9,CXCL10,MMP9,and MMP12 were significantly higher in CS group and SC group than those in the normal control group(all P＜0.05). The protein expression levels of CXCL9,CXCL10,CXCL11,MMP2,MMP9,MMP12,and TGF-β1 were significantly higher in CS group and SC group than those in the normal control group(all P＜0.05). Compared with the normal control group,the concentrations of CXCL9,CXCL10,CXCL11,IL-8,and TGF-β1 in the BALF supernatants of the CS group and SC group significantly increased(P＜0.05);in addition,the IL-6 and TNF-α concentrations also increased in the CS group(both P＜0.05). Conclusions CS exposure triggers inflammatory cell flux and accumulation in the lung parenchyma and BALF. As a consequence,the inflammatory cytokines increase dramatically. After CS,the cytokines/chemokines can decrease,but is still higher than in non-smokers.