TGF-β_1、TNF-α及羟脯胺酸在大鼠放射性肺损伤中的变化及意义

CHANGES AND SIGNIFICANES OF TGF-β_1,TNF-α AND HYDROXYPROLINE IN RADIATION-INDUCED PULMONARY INJURY

目的:探讨大鼠放射性肺损伤与炎症反应、纤维化改变的相关机制。方法:SD大鼠分为3组:对照组、7.0Gy放射损伤组、14.4Gy放射损伤组。其中放射损伤组大鼠麻醉后用60 Co治疗机单次照射右全肺;在照射后的1,7,30,90d,取大鼠右肺组织进行HE、Masson染色检查;免疫组化检测肺组织转化生长因子β1(TGF-β1)、肿瘤坏死因子(TNF-α)的表达,并检测羟脯胺酸的含量变化。结果:14.4Gy组观察到明显的纤维化改变;免疫组化染色显示在各观察时点TGF-β1、TNF-α均为阳性表达;羟脯胺酸含量30d后明显增加,至90d时达最大值,与对照组比较差异有统计学意义(P<0.05)。结论:放射性肺损伤的炎症反应激发了放射性肺损伤的纤维化进程。

Objective：To investigate the possible mechanisms of radiation-induced lung fibrosis.Methods：The right hemithorax of SD rats were irradiated with a single dose of 7.0 Gy and 14.4 Gy.All animals were sacrificed and the lungs were removed at 1,7,30 and 90 days after radiation.The histopathological changes,hydroxyproline content and expression of transforming growth factor-β1（TGF-β1）,tumor necrosis factor-α（TNF-α） between the radiation and control groups were analyzed by HE staining,Masson staining and immunohistochemistry.Results：In control group and 7.0 Gy groups,there were no notable histopathological changes,just including little tissue exudates,congestion,edema and infiltration of inflammatory cells,red blood cell leakage.However,the formation of collagen and fibrosis could be observed in 14.4 Gy group.The expression of TGF-β1,TNF-α was negative or weak positive in the control group and radiation groups.But,both them were increased in 14.4 Gy group.The content of hydroxyproline was little changes in the control and 7.0 Gy groups at every time point,it increased at 30 days significantly,and up to maximum at 90 days in 14.4 Gy group after radiation.Conclusion：Radiation-induced lung injury in the inflammatory response stimulated radiation lung injury and fibrosis process.