染矽尘大鼠肺组织不同时间点FasL表达与细胞凋亡

Expression of FasL and apoptosis in pulmonary tissue of rats exposed to silica at different time

目的探讨染矽尘大鼠肺组织FasL表达及细胞凋亡在矽肺病理变化中的意义。方法将96只Wistar大鼠随机分为对照组和染矽尘组。对染矽尘组以暴露式气管内一次注入二氧化硅粉尘悬液(1 ml,0．2 g/kg)建立大鼠矽肺模型,对照组气管内注入1 ml灭菌生理盐水。分别于处理后1、3、7、14、21和28 d,每组分别取8只大鼠处死取肺组织,用组织芯片技术结合免疫组化SP法检测大鼠肺组织不同时间点FasL的表达;末端脱氨核苷酸转移酶末端标记技术(TUNEL)法检测大鼠肺组织细胞凋亡,并采用Image-Pro Plus Version 4．5 for windowsTM图像分析计算积分光密度。结果染矽尘组大鼠肺组织FasL在染矽尘后的7、14、21和28 d时,表达明显高于对照组,差异有统计学意义(P<0．05),14 d时表达最高为157．50±23．12;染矽尘组大鼠肺组织凋亡阳性细胞在染矽尘后的1、3、7、14、21和28 d时,明显高于对照组,差异有统计学意义(P<0．05),7和14d,分别最高为32．95±20．40和31．07±7．15。结论矽尘能导致肺组织细胞凋亡;FasL在染矽尘大鼠肺组织多种细胞中表达并介导细胞的凋亡,凋亡细胞主要以炎性细胞为主。

Objective To investigate the change of the expression of the FasL Ligand and apoptosis in the pathology of silicosis of the rats exposed to silica and their roles. Methods Ninety-six wistar rats were randomizdly divided into the control group and the experimental group. The sificotic animal model was established by the direct tracheal instillation of silica into rat lungs surgically. The control rats underwent directly tracheal instillation of saline into lungs surgically. Eight rats from each group were sacrificed at different days. The expression of Fas Ligand in the tissue of the model rats was detected by tissuechip microarray and immunohistochemistry and the cell apoptosis induced by silica was determined by TdT-mediated dUTP nick end-labeling method. The integral optical density of positive cells were quantitatively analyzed using Image-Pro Plus Version 4.5 for windows. Results The expression of FasL in the lung tissue of the model rats on the 7th,the 14th,the 21st,and the 28th day was significantly higher than that in the control group （P〈0.05）,and peaked at the 14th day after exposure to silica. Apoptotic cells in the lung tissue of the model rats on the lst, the 3rd,the 7th,the 14th,the 21st,and the 28th day were significantly more than those in the control group, and peaked at the 7th and the 14th day after exposure to silica. Conclusion Silica can lead to apoptosis in lung tissues. FasL is expressed in all kinds of cells in the pulmonary tissues of the rats exposed to silica and leads to apoptosis. From the 7th day to 14th day, inflammatory cells dominate in apoptotic cells.