内质网应激及自噬相关蛋白在矽肺患者肺泡巨噬细胞中表达研究

Expression of endoplasmic reticulum stress and autophagy-related proteins of alveolar macrophage in patient of silicosis

目的研究矽肺患者肺泡巨噬细胞(AM)内质网应激(ERS)和自噬相关蛋白的表达规律。方法采用单纯随机抽样方法,选择矽肺壹期、贰期、叁期男性患者20、28、22例分别设为矽肺壹期、贰期和叁期组,以6例诊断为观察对象的男性矽尘作业工人为对照组。收集研究对象的支气管肺泡灌洗液,分离、纯化和培养AM,经裂解后提取蛋白,采用免疫印迹法检测AM中葡萄糖调节蛋白78(GRP78)、Beclin1和微管相关蛋白1轻链3(LC3)蛋白的相对表达水平。结果矽肺壹期、贰期和叁期患者AM中GRP78、Beclin1和LC3的蛋白相对表达水平均高于对照组(P<0.05),矽肺贰期和叁期组患者上述3个指标均高于矽肺壹期组(P<0.05),矽肺叁期组患者AM中GRP78蛋白相对表达水平低于矽肺贰期组(P<0.05);矽肺叁期组患者AM中Beclin1和LC3的蛋白相对表达水平均高于矽肺贰期组,但差异均无统计学意义(P>0.05)。多重逐步线性回归分析结果显示,矽肺患者AM中GRP78、Beclin1和LC3的蛋白相对表达水平均与矽肺期别呈正相关(P<0.01)。结论不同期别矽肺患者AM中ERS和自噬的相关蛋白表达程度不同,AM的ERS和自噬在矽肺纤维化发生发展中可能发挥重要作用。

Objective To study the expression of endoplasmic reticulum stress（ ERS） and autophagy-related proteins of alveolar macrophage（ AM） in silicosis patients. Methods With simple random sampling,the male patients of silicosis at stage Ⅰ,Ⅱand Ⅲ were respectively chosen as the silicosis groupⅠ,Ⅱ and Ⅲ with 20,28,22 cases in each group. Six male observed subjects exposed to silica dust were selected as the control group. Bronchoalveolar lavage fluids of wholelung lavage of all subjects were collected. After AM were separated,purified cultured and lysed,the relative protein expression levels of glucose regulated protein78（ GRP78）,Beclin1 and microtubule-associated protein 1 light chain 3（ LC3） were assayed by Western blot. Results Relative expression levels of GRP78,Beclin1 and LC3 proteins in AM of silicosis groupⅠ,Ⅱ and Ⅲ were significantly higher than those of the control group respectively（ P〈0. 05）,the above three indicators of silicosis groupⅡ and Ⅲ were significantly higher than those of the silicosis group Ⅰ respectively（ P〈0. 05）,and the relative expression level of GRP78 protein in AM of silicosis group Ⅲ was significantly lower than that of the silicosis groupⅡ（ P〈0. 05）. Relative expression levels of Beclin1 and LC3 proteins in AM of silicosis group Ⅲ were higher than those of the silicosis group Ⅱ respectively,but there was no statistical significant difference（ P〈0. 05）.Analysis results of multiple stepwise linear regression indicated that there was a positive correlation between relative expression levels of GRP78,Beclin1 and LC3 proteins respectively in AM of silicosis patients and the stage of silicosis（ P〈0. 01）. Conclusion The related protein expression levels of ERS and autophagy in AM are different among silicosis patients at different silicotic stages. ERS and autophagy of AM may play an important role in the formation and development of silicosis.