PDTC对百草枯致肺纤维化大鼠细胞外基质成分的影响  

Effects of pyrrolidine dithiocarbamate on expressions of or-smooth musck actin, integrina5 and fibronectin in acute paraquat poisoned rats

作　　者：黄敏[1] 杨惠芳[1] 张平[2] 常秀丽[2] 周志俊[2] 

机构地区：[1]宁夏医科大学公共卫生学院劳动卫生与职业病教研室,宁夏银川750004 [2]复旦大学公共卫生学院/教育部公共卫生安全重点实验室

出　　处：《中华劳动卫生职业病杂志》2013年第5期341-346,共6页Chinese Journal of Industrial Hygiene and Occupational Diseases

基　　金：宁夏高等学校科学研究项目（[2011]63）;宁夏回族自治区卫生厅重点科研计划课题（2102005）;宁夏医科大学特殊人才启动项目（XT2011001）

摘　　要：目的观察急性百草枯（PQ）中毒大鼠a平滑肌动蛋白（a—SMA）、整合素仅5、纤维连接蛋白（Fn）的动态变化及四氢吡咯二硫代氨基甲酸酯（PDTC）的干预效果，探讨PQ致肺纤维化机制。方法SD大鼠随机分为对照组（6只）、PQ染毒组（36只）、PDTC干预组（36只）。染毒组和干预组给予生理盐水稀释PQ（80mg／kg）一次性灌胃后2h，染毒组给予等量生理盐水腹腔注射，PDTC干预组给予PDTC（100mg／kg）一次性腹腔注射；对照组给予生理盐水1ml／kg灌胃后2h，给予等量生理盐水腹腔注射。于不同处理后1、3、7、14、25、56d观察大鼠中毒表现；蛋白免疫印迹法（Westernblot）测定大鼠肺组织a-SMA蛋白表达；实时荧光定量多聚酶链式反应（realtimePCR）测定整合素a5、FnmRNA表达水平；同时观察中毒大鼠的肺组织病理变化。结果染毒组肺组织d—SMA蛋白表达随时间延长而逐渐升高，3、7、14d升高幅度缓慢，28～56d增幅较大，各时段均明湿高于对照组，差异有统计学意义（P〈0．01）。与对照组比较，染毒组染毒后1、3d时整合素a5mRNA表达无明显变化，7～56d时基因水平明显升高，差异有统计学意义（P〈0．05或P〈0．01）。Fn基因表达的变化规律与整合素cdmRNA类似，染毒组各时段的FnmRNA水平明显高于对照组，差异有统计学意义（P〈0．05或P〈0．01）。经PDTC干预后，a-SMA蛋白表达、整合素55mRNA、FnmRNA表达水平明显低于染毒组，相应时点的差异有统计学意义（R0．05或R0．01）。Masson染色可见14～28d染毒组肺组织成纤维细胞大量增殖，胶原纤维数量逐渐增多；PDTC干预组上述病理改变明显减轻，各时段的病理评分明显低于染毒组，差异有统计学意义（P〈0．05或P〈0．01）。结论成纤维细胞的表型转化（仅-SMA）、细胞外基质成分整合素a5、Fn基因表达增强是PQ致肺纤维化的重要机制；PDTCObjective To observe the expressions of a-SMA, integrina5 and fibronectin（Fn） in acute paraquat poisoned rats and the effect of PDTC. To investigate the mechanism of paraquat-induced puhnonary fibrosis. Methods Sprague-Dawley rats were randomly divided into three experimental groups： Control group （6 rats）, PQ group （36 rats） and PQ＋PDTC group （36 rats）. On the 1 st, 3rd, the 7th, the 14 th, the 28 th and the 56 th day after exposure, the protein expression of a smooth muscle actin （a-SMA） was evaluated by western blot. The mRNA levels of integrin a5 and fibronectin （Fn） were analyzed with real-time quantitative PCR （RT- PCR）. Meanwhile, the lung pathological changes were observed and semiquantified. Results TWith the time passing, the expression of a-SMA in PQ group increased gradually compared with control group （P〈0.05 or P〈 0.01 ）. The increasing extent was gently on the 3 rd, the 7 th day. While increasing extent was rapidly from the 28 th to the 56 th day. RT-PCR showed PQ significantly increased Fn mRNA level on all time points and increased intrgrin a5 mRNA level from the 7 rd to 56 th day compared with control group （P〈0.05 or P〈0.01 ）. PDTC treatment siganificantly deceased a-SMA, Fn, and integrina5 levels compared with PQ group in corresponding time points （P〈0.05 or P〈0.01 ）. Noteworthy, in PQ＋PDTC group, the occurrence of pathological changes were drastically attenuated and pathologic score significantly decreased （P〈0.05 or P〈0.01 ）. Conclusions a-SMA, integrin a5 and fibronectin could play an important role in the development of pulmonary fibrosis caused by paraquat poisoning. PDTC, as a strong NF-KB inhibitor, may inhibit NF-KB activity and futher significantly decreased expressions of a-SMA, integrin a5 and fibronectin which were important part of ECM, leading to drastically attenuated pulmonary fibrosis. However, the mechanisms of PDTC intervention still remains to be explored.

关 键 词：百草枯 急性肺损伤 肺纤维化 细胞外基质蛋白质类 

分 类 号：R595.4[医药卫生—内科学]