双氢青蒿素对放射性肺损伤小鼠肺部炎症和氧化应激的作用

Effects of dihydroartemisinin on pulmonary inflammation and oxidative stress in mice with radiation-induced lung injury

目的:探讨双氢青蒿素(DHA)对放射性肺损伤(RILI)小鼠肺部炎症及氧化应激的作用。方法:将54只C57BL/6小鼠随机分为空白组、DHA组、单纯照射模型组(IR组)3组,每组18只。DHA组用DHA灌胃7 d,其余组给予生理盐水,对DHA组和IR组小鼠进行双肺单次20 Gy剂量的照射,分别于照射后7 d、14 d处死,取肺组织,分别采用苏木精—伊红(HE)染色和免疫组化染色观察组织学改变及肺部转化生长因子-β(TGF-β)、肿瘤坏死因子-α(TNF-α)的表达情况;在透射电镜下观察肺组织线粒体超微结构改变;肺组织冰冻切片染色观察活性氧(ROS)水平。采用酶联免疫吸附试验(ELISA)测定肺组织中TGF-β、TNF-α含量;采用BCA蛋白检测试剂盒及SOD检测试剂盒检测小鼠肺组织中总蛋白含量及SOD活性。结果:HE染色及免疫组化结果显示,空白组在照射后各时间点肺组织均无炎症反应且仅出现部分TGF-β、TNF-α弱阳性表达;DHA组在照射后各时间点仅出现轻度肺部炎症改变及部分TGF-β、TNF-α阳性表达,IR组则多为中度以上肺部炎症及较高水平TGF-β、TNF-α阳性表达。照射后各时间点ELISA结果显示,空白组和DHA组肺组织TGF-β、TNF-α含量均低于IR组(P<0.05);照射后14 d,空白组和DHA组肺组织总蛋白含量及SOD活性高于IR组(P<0.05);透射电镜下显示,空白组线粒体结构基本正常,IR组线粒体超微结构严重受损,DHA组线粒体超微结构损伤程度明显减轻;肺组织切片ROS荧光显示,IR组肺组织的ROS阳性表达细胞多于空白组小鼠,DHA组较IR组减少。结论:DHA能有效抑制RILI小鼠肺部炎症反应和氧化应激。

Objective:To investigate the effects of dihydroartemisinin(DHA)on pulmonary inflammation and oxidative stress in mice with radiation-induced lung injury(RILI).Methods:Fifty-four C57BL/6 mice were randomly divided into blank group,DHA group,and irradiation model group(IR group),with 18 mice in each group.Mice in DHA group were treated with DHA by gavage for 7 days,while mice in other groups were given normal saline solution.Mice in DHA group and IR group were irradiated with a single dose of 20 Gy in both lungs.The mice in both groups were sacrificed at 7 and 14 days after irradiation.The histological changes and the expression of TGF-βand TNF-αin lungs were observed by HE staining and immunohistochemical staning.The ultrastructural changes of mitochondria in lung tissue were observed by transmission electron microscope.The level of reactive oxygen species(ROS)was observed by staining in frozen sections of lung tissue.Enzyme-linked immunosorbent assay(ELISA)was used to determine the contents of TGF-βand TNF-αin lung tissue.BCA protein detection kit and SOD detection kit were used to detect the content of total protein and SOD activity in lung tissue of mice.Results:The results of HE and immunohistochemical staning showed that in the blank group,there was no inflammatory reaction and only some weak positive expressions of TGF-βand TNF-αin the lung tissues at each time point after irradiation.In the DHA group,only mild pulmonary inflammatory changes and some positive expressions of TGF-βand TNF-αappeared at each time points after irradiation.In the IR group,more than moderate pulmonary inflammation and higher levels of TGF-βand TNF-αpositive expression were found.The results of ELISA showed that the contents of TGF-βand TNF-αin lung tissue of blank group and DHA group were significantly lower than those in IR group at each time point after irradiation(P<0.05),and the contents of total protein and SOD in lung tissue in blank group and DHA group were significantly higher than those in IR group after 14 days irradiation(P<0.05).Transmission electron microscope showed that the structure of mitochondria in blank group was basically normal,the ultrastructure of mitochondria in IR group was seriously damaged,and the degree of mitochondrial ultrastructure damage in DHA group was significantly alleviated.ROS fluorescence showed that the number of ROS positive cells in lung tissue of IR group was more than that of blank group,and the DHA group was less than that of IR group.Conclusion:Dihydroartemisinin can effectively inhibit pulmonary inflammation and oxidative stress disorder in mice with radiation-induced lung injury,which is worthy of further study.