PC12细胞缺氧后细胞凋亡与DNA损伤相关基因表达关系的研究

目的 探讨PC12细胞缺氧后细胞凋亡与DNA损伤的关系。方法 采用TUNEL法，结合应用流式细胞术观察PC12细胞缺氧培养不同时间点细胞凋亡现象，以及DNA损伤相关基因表达的改变。结果 在缺氧0.5h开始出现凋亡细胞，引时P53、P21^waf1/cip1蛋白表达开始增高。至缺氧1h凋亡细胞达高峰，此时P53、P21蛋白表达最高（P＜0.05）。至缺氧6－12h，则以坏死为主，此时以上基因表达均减弱。结论 PC12细胞在缺氧早期（0.5-2h）主要出现以凋亡为主的细胞死亡，伴有DNA损伤相关基因表达的动脉改变，提示缺氧后PC12细胞凋亡部分是由于DNA损伤严重、损伤不能及时修复所致。

The study of the relationship between PC12 cell apoptosis and the expression of DNA damage related genes after hypoxia

Objective To investigate the relationship between apoptosis andDNA damage after hypoxia in PC12 cell. Methods The apoptosis of PC12 cell at different time points after hypoxia was determined by TUNEL techniques, and the expression of DNA damage related genes was observed by flow cytometry techniques. Results Apoptotic cells appear at 30th ain after hypoxia and the expression of protein P53,P21waf1/civ1 begin to increase. Apoptosis cell come to a peak and the expression of protein P53,P21 arrive to the top at 1th hour following hypoxia (P＜0.05). At 6th hour and t2th hour after hypoxia,PC12 cells are mainly necrostic and expression of the genes also decreased. Conclusion In the early period after hypoxia of PC12 cell(0.5～2h) ,cell death mostly are apoptosis companied with the increased expressions of DNA damage related genes. Therefore apoptosis of PCl2 cell after hypoxia partly is caused by serious DNA damage which cannot be repaired.