吸烟者Clara细胞形态和功能的改变

目的 :观察吸烟者小气道中Clara细胞形态和功能的改变 ,了解Clara细胞在吸烟所致肺部损伤中的作用。方法 :收集手术肺组织标本 5 4例 ,免疫组织化学法观察小气道中Clara细胞分布及所占比例 ,RNA酶保护实验测定肺组织中Clara细胞 16kD特异性分泌蛋白 (CC16 )mRNA表达并用Western法测定CC16蛋白水平。结果 :终末及呼吸性细支气管中 ,Clara细胞占上皮细胞的比例在吸烟组较非吸烟组减低 (终末细支气管 11 7%、18 8% ;呼吸性细支气管 15 2 7%、2 5 32 % ,P <0 0 1)。戒烟组较吸烟组回升 (分别为 19 4 1%、13 2 % ,P <0 0 5 )。吸烟组杯状细胞增生明显 ,P <0 0 1。呼吸性细支气管中 ,戒烟组杯状细胞增生明显减轻 ,P <0 0 1。吸烟组肺组织中CC16mRNA表达 (0 2 9± 0 0 2、0 5 1± 0 0 6 ,P <0 0 1)及蛋白水平 (0 87± 0 12、1 78± 0 31,P <0 0 1)均下降 ,戒烟组有所恢复 ,但无显著性差异。结论 :吸烟破坏Clara细胞 ,使其分泌蛋白CC16表达减少 ,戒烟可使Clara细胞的破坏部分恢复。Clara细胞数目减少与功能的变化削弱人体保护机制 ,导致肺损伤。其改变可能是吸烟所致肺部疾病形成的机制之一。

The change of Clara cell in smokers

Objective:To observe the morphological and functional changes of Clara cell in the distal conducting airways of smokers and discuss the roles of Clara cell in the smoking induced lung injury.Method:54 lung samples were collected and divided into three groups:non|smoker,smoker and ex|smoker groups.Detected the distribution and number of Clara cell by immunohistochemistry.Measured the expression of Clara cell 16 kD protein(CC16)mRNA and the proteins level by ribonuclease protection assay and Western blot separately.Result:The numbers of Clara cell in respiratory and terminal bronchioli decreased in smokers(15.27% vs.25.32%,11.7%vs.18^8%, P <0.01)and there are some restorawtions in ex|smokers(19^41% vs.13^2%, P <0.05).Hyperplasia of Goblet cell can be seen in the small conducting airways of smokers, P <0.01,and alleviated in respiratory bronchioli of ex|smokes.The level of CC16 mRNA and protein are lower in smokers than non|smokers (mRNA:0^29±0^02 vs.0^51±0^06, P <0.01;protein:0.87±0.12 vs.1.78±0.31, P <0.01).The ex|smokers have no significant recovery.Conclusion:Smoking destroy Clara cell and induce the decrease of CC16.The changes have some reversibility after stoping smoking.The decreases of the Clara cell may weaken the self|protection mechanism and incuced the lung injury.The changes of the number and function of Clara cell may be one of the factors in the development of pulmonary diseases in smokers.