缺血缺氧对体外培养星形胶质细胞细胞活化和细胞周期的影响

目的观察缺血缺氧损伤对星形胶质细胞细胞活化和细胞周期的影响。方法用流式细胞仪及BrdU掺入法检测缺血缺氧后不同时间点星形胶质细胞细胞周期变化和细胞的增殖活力;用荧光免疫细胞化学技术测定胶质细胞纤维酸性蛋白(GFAP)及细胞周期蛋白cyclinD1的表达水平。结果体外缺血缺氧损伤后星形胶质细胞S期较正常组明显增高,6h达高峰,BrdU掺入法显示损伤后6h星形胶质细胞的增殖活力最高,而随后S期细胞数目及细胞增殖活力都呈下降趋势。在缺血缺氧早期,GFAP阳性染色增强,6h最高;缺血缺氧12h后GFAP阳性染色变弱,而cyclinD1的表达在损伤后逐渐增加,在24h时达高峰。结论缺血缺氧损伤激活星形胶质细胞,使其进入新的细胞周期,出现细胞的增殖反应;cyclinD1参与了损伤后星形胶质细胞的修复和增殖;细胞周期事件与星形胶质细胞的增殖活化密切相关。

EFFECTS OF ISCHEMIA AND ANOXIA ON CELL ACTIVATION AND CELL CYCLE OF CULTURED ASTROCYTES IN VITRO

Objective To study the effects of ischemia and anoxia on cell activation and cell cycle of astrocytes in vitro. Methods We measured the cell cycle and the proliferation of astrocytes at different times after ischemiaand anoxia by flow cytometry and BrdU incorporation; and detected the expression of GFAP and cyclin D1 with fluorescence immunocytochemistry. Results After ischemiaand anoxia in vitro, astrocytes in the S phase significantly increased when compared with the normal, and the peak appeared at 6h. The proliferation ability of the astrocytes was highest at 6h by BrdU incorporated labeling. After 6h, the number of astrocytes in the S phase and the proliferation ability began to decreased. At the early stage of ischemiaand anoxia, the positive staining of GFAP increased; but after 12 hours, the positive staining of GFAP was weak. The expression of cyclin D1 was gradually increased after damage, and the peak appeared at 24h. Conclusion Astrocytes are activated to proliferate and enter into new cell cycle by ischemiaand anoxia. Cyclin D1 is involvad in astrocyte's proliferation and repairing. The cell cycle events are closely related with proliferation and activation of astrocytes.