X线照射后体外培养星形胶质细胞VEGF和GFAP表达变化及意义  

Expression changes of VEGF and GFAP in cultured rat astrocytes after irradiation by X-ray and their significances

作　　者：周桂娟[1] 黄海威[1] 吴小红[1] 吴萌萌[1] 

机构地区：[1]中山大学附属第一医院神经科,广州510080

出　　处：《中华神经医学杂志》2013年第4期369-375,共7页Chinese Journal of Neuromedicine

基　　金：国家自然科学基金（81271386）;广东省科技计划基金（20108030700010）

摘　　要：目的研究x线照射体外培养的星形胶质细胞后血管内皮生长因子（VEGF）和胶质原纤维酸性蛋白fGFAP）表达随时问及剂量的变化，探讨星形胶质细胞与放射性脑损伤（RBI）的关系。方法以5、10、15、20Gy剂量的X线照射体外原代培养的星形胶质细胞后继续培养48h，或以20Gy剂量照射后分别培养4、12、24、48h，实验均设正常对照组即未照射组。免疫荧光染色检测GFAP观察各组细胞形态学的变化：DAPI染色观察星形胶质细胞的凋亡；Westernblotting检测细胞GFAP、VEGF蛋白的表达情况。结果与正常对照组比较，不同剂量照射组星形胶质细胞增生、增多，变形，胞体肥大肿胀，分支增多，突起增粗，GFAP染色加深，且这种变化随照射剂量和时间增加而表现更明显；与正常对照组相比，各剂量照射组星形胶质细胞凋亡率差异无统计学差异f尸〉0．05）：Westernblotting检测显示不同剂量组、20Gy剂量照射不同时间组星形胶质细胞GFAP、VEGF蛋白的表达均不同，差异有统计学意义畔0．05）。与正常对照组相比，5、10、15、20Gy照射组和20Gv剂量照射后各时间组GFAP、VEGF的蛋白表达均增高，且随着照射剂量的增加GFAP、VEGF的蛋白表达亦增高，差异有统计学意义（P〈0．05）。20Gy剂量照射后4～48h内GFAP的表达呈时间依赖性，20Gv剂量照射后4～24h内VEGF的表达呈时间依赖性。结论X线能诱导体外培养的星形胶质细胞活化，GFAP及VEGF的表达呈时间及剂量依赖性增高，VEGF异常高表达可能是造成RBI的重要原因。Objective To investigate the time- and dose-related expressions of vascular endothelial growth factor （VEGF） and glial fibrillary acid protein （GFAP） in cultured rat astrocytes after irradiation by X-ray, and discuss the possible relationship between astrocytes and radiation brain injury （RBI）. Methods Rat astrocytes primarily cultured in vitro were exposed to X-ray at various doses （5, 10, 15 and 20 Gy） and kept culturing for 48 h, and some other rat astrocytes primarily cultured ir~ vitro were exposed to 20 Gy and kept culturing for 4, 12, 24 and 48 h, respectively; normal control groups （without radiation） were used in all the above experiments. Immunofluorescence staining was employed to detect the level of GFAP and observe the cell morphology changes in each group; DAPI staining was used to observe the apoptosis of astrocytes; VEGF and GFAP expressions were detected by Western blotting. Results As compared with astrocytes in the normal control group, astrocytes in the radiation group showed increased number, hyperplasia, deformation, swelling of the cell body, thickening processus and deepened GFAP staining; and these changes became obvious following the increment of time and radiation doses. No significant differences on the astrocyte apoptosis rate were noted between the normal control groups and the radiation groups of different doses （P〉0.05）. Western blotting indicated that the irradiation groups of different doses and the 20 Gy radiation groups of different exposing times had significantly different GFAP and VEGF protein expressions （P〈0.05）. The expressions of GFAP and VEGF were up-regulated gradually with the increment of radiation doses in astrocytes and times of radiation （P〈0.05）; as compared with the control group, 20 Gy radiation groups of different exposing times showed time dependent VEGF expression from 4 to 24 h and time dependent GFAP expression from 4 to 48 h （P〈0.05）. Conclusion X-ray irradiation can induce the activation of cultured rat astrocy

关 键 词：X射线 放射性脑损伤 星形胶质细胞 胶质原纤维酸性蛋白 血管内皮生 长因子 

分 类 号：R7[医药卫生—临床医学]