汽油机尾气致大鼠慢性肺损伤时Caveolin-1与TGF-β1表达

Expressions of Caveolin-1 and TGF-β1 in Rat Lung Injured by Inhaling Gasoline Engine Exhaust

目的探讨Caveolin-1与TGF-β1在汽油机尾气致慢性肺损伤中的表达规律。方法雄性健康SD大鼠54只,随机分为为正常对照组6只,实验组48只(实验组又分1 d、3 d、5 d、7 d、2 w、4 w、8 w和12 w亚组,每亚组6只);将实验各组动物置于自制的染毒箱后启动汽油机,将汽油机尾气通入染毒箱进行染毒,每天染毒2h;各实验组分别染毒1 d、3 d、5 d、7 d、2周、4周、8周、12周,实验各组的动物在最后一次染毒24 h后被处死,用免疫组织化学技术检测肺部Caveolin-1与TGF-β1表达变化;用图像分析技术对免疫组化结果进行分析。结果 Caveolin-1在正常对照组支气管上皮、肺泡上皮、成纤维细胞呈较强的阳性表达,主要位于细胞膜上;汽油机尾气染毒后,Caveolin-1表达先增强后减弱,在7 d后达高峰,此后逐渐降低,2周后显著降低,此后一直维持在很低的水平表达。TGF-β1主要表达于支气管上皮、肺泡上皮、成纤维细胞胞浆;在正常对照组表达微弱,1 d、3 d组的表达强度较对照组略高,5 d后表达逐渐增强,至2周时达高峰,此后稍有降低,但仍然较正常对照组高。结论 Caveolin-1与TGF-β1均参与了汽油机尾气造成的肺慢性损伤的病理生理过程,且其表达时相大致相反,提示Caveolin-1对TGF-β1有抑制作用。

Abstract Objective To explore the expression pattern of caveolin - 1 and TGF - 1 in lungs of rat after inhaled gasoline engine exhaust and suffered chronic lung injuries. Methods Fifty four male SD rats were randomly divided into 9 groups, with 6 in control group and the other 48 in 8 experimental groups （ ld, 3d, 5d, 7d, 2w, 4w, 8w, 12w）. Each experimental group were put into a self - made exposure cabinet where gasoline engine gasoline engine exhaust was discharge into, two hours a day. Experimental subgroups were respectively exposed to the engine exhaust for one day, 3 days, 5 days, 7 days, 2 weeks, 4 weeks, 8 weeks and 12 weeks. All animals in experimental groups were sacrificed 24 hours after the last exposure. The expressions of caveolin - 1 and TGF - β1 in the lung were detected by immunohistochemistry technique and the results were analyzed by image analysis system. Results The expression of Caveolin - 1 showed strong positive in the bronchial epithelium, alveolar epithelium and fibroblasts of the control group, mainly on the cell membrane. While the animals exposed to the gasoline engine ex- haust, the expression increased within 7 days, and then decreased gradually and reduced significantly after 2 weeks. Thereafter, the expression stayed at a very low level. The expressions of TGF - [31 showed a very weak positive exp lar epithelium and fibroblasts of the control group, as well as 1 d and er, the expression increased, and reached the peak in two weeks. still higher than that of the control group. Conclusion Caveolin - ression in the bronchial epithelium, alveo- 3d experimental subgroups. Five days lat- Thereafter it decreased a little slight yet 1 and TGF - β1 are both involved in the pathophysiological process of chronic lung injury caused by the gasoline engine exhaust, and the expressions phase of both are roughly opposite, suggesting that caveolin - 1 may be a inhibitor of TGF