缺氧的血清剥夺诱导的PC12细胞DNA损伤与修复

探讨PC12细胞在缺氧(37℃,5%O2,95%N2)、血清剥夺条件下DNA损伤与修复、凋亡、坏死或生存的变化规律.应用单细胞凝胶电泳技术、流式细胞学技术检测在不同时间点,缺氧、无血清培养等诱导下对PC12细胞单链DNA损伤与修复、凋亡的影响.结果发现在PC12细胞DNA损伤值均在0.5h时达第一个峰值,随后下降.3h后DNA损伤数值再次逐渐增加并达到最高值.细胞凋亡峰值略滞后于DNA损伤峰值,并于DNA损伤程度基本相平行.提示PC12细胞在缺氧和血清剥夺条件下存在DNA损伤与修复的动态变化过程,DNA损伤后可能直接诱导细胞凋亡,DNA损伤程度在早期与细胞凋亡程度相一致.

The DNA Damage and Repair and Apoptosis in PC12 Cells Induced by Anoxia and Serum Deprivation

Under the condition of anoxia (37 ℃, 5 % 02 and 95 % N2)and serum deprivation, the changes in the DNA damage, DNA repair and apoptotic cell death or cells survival of PC12 cells were observed. Single cell gel electrophoresis and flow cytometry were used to detect the induction of DNA damage, DNA repair and apoptosis in PC12 cells in the different time intervals. It was found that the DNA damage was increased to a high level at 30 min and then decreased at 1 h (the cells with serum deprivation), but the damage scores increased gradually to the peak again after 3 h. There was a time delay in the peak of apoptotic cells after the peak of DNA damage. Dynamic changes of DNA damage and repair was induced and observed in the PC12 cells after the insults by anoxia or withdrawal of serum. There was a repair mechanism when the cells were damaged. The peak of apoptosis was paralleled and somewhat delayed with the degree of DNA damage after anoxia or serum deprivation in the PC12 cells in the early time. Cell apoptosis might be induced by the cell DNA damage.