香烟烟雾联合脂多糖对气道炎症及衰老的影响

Effect of cigarette smoke exposure combined with LPS oninflammation and aging of lung

目的:观察熏烟联合脂多糖(LPS)对气道炎症及肺组织、上皮衰老的影响.方法:将C57雄性小鼠随机分为假熏烟联合假手术组,熏烟联合假手术组,假熏烟联合LPS组,熏烟联合LPS组,每天熏烟2次,3支/次,第28、42天小鼠气管内滴注LPS,实验7周后取材.结果:与假熏烟小鼠比较,熏烟小鼠体重下降明显(P<0.05);与假熏烟联合假手术组小鼠对比,熏烟联合LPS组小鼠支气管灌洗液细胞总数和巨噬细胞计数明显增加(P<0.05),气道灌洗液细胞过氧化物产出率明显增加(P<0.05),肺组织中MMP12 mRNA和P21蛋白表达明显增加(P<0.05).与假熏烟联合LPS组小鼠比较,熏烟联合LPS组小鼠肺组织IL-6 mRNA表达降低(P<0.05),MMP12 mRNA表达升高(P<0.05).香烟提取物(CSE)联合LPS处理的A549细胞β-gal阳性染色细胞数量高于空白组,CSE组和LPS组(P<0.05).结论:香烟烟雾联合LPS气道滴注增加正常小鼠气道炎症和氧化应激,但增加水平低于单纯LPS滴注小鼠.香烟烟雾联合LPS增加气道细胞衰老和MMP12表达,且作用强于单纯LPS滴注.

Objective:To study the effects of 7-week cigarette smoke exposure combined with lipopolysaccharide(LPS)airway instillation on inflammation and senescence of lung in mice.Methods:C57/BL6 male mice were randomly divided into sham+vehicle group,CS+vehicle group,sham+LPS group,and CS+LPS drip group.Mice were exposed to cigarette smoke/sham in a manner of 3 cigarettes for 1h and twice a day.In day28 and day42,mice were instilled with 30μl LPS/PBS into trachea and without smoke exposure.Results:Compared with sham mice,the smoked mice had significant weight loss(P<0.05).Compared with sham+vehicle mice,the total number of BALF cells and macrophage counts,ROS production rate of BALF cells,MMP12 mRNA and P21 protein were increased significantly in the CS+LPS group(P<0.05).Compared with sham+LPS mice,the IL-6 mRNA expression in lung was decreased(P<0.05)and MMP12 mRNA expression was increased(P<0.05)in CS+LPS treated mice.In vitro,CSE+LPS treated A549 cells were with moreβ-Galactosidase Staining than blank,CSE and LPS treated cells(P<0.05).Conclusion:Cigarette smoke combined with LPS stimulation increased the inflammation and oxidative stress in lungs and the level is lower than LPS treated mice.However,cigarette smoke increase MMP12 expression and senescence in LPS treated lungs and epithelium.