细胞凋亡技术应用于电离辐射遗传损伤的研究

Study on cells apoptosis in the bone marrow induced by low dose rate irradiation

目的 了解不同剂量的辐射及不同时间段对小鼠骨髓细胞凋亡率的影响,比较PI/FITC-Annexin Ⅴ双染和PI单染2种荧光剂检测细胞凋亡方法的差异.方法 以60Co射线照射ICR小鼠,制备不同时间段的骨髓单个核细胞的单细胞悬液,用PI/FITC-Annexin v双染和PI单染法,通过流式细胞仪检测样品的凋亡率.结果 PI/FITC-Annexin Ⅴ方法检测出的骨髓单个核细胞早期凋亡率于6～24 h达到最高且与辐射剂量之间无正相关性;较低剂量辐射组凋亡率的下降速度明显高于大剂量辐射.PI单染法只能检测样本的总凋亡率.在各时间点,骨髓细胞的总凋亡率随辐射剂量增大而增高.结论 小剂量辐射相对于大剂量辐射单位剂量下的细胞凋亡率更高,因此能更加有效地清除受损细胞,保护机体.只有PI/FITC-Annexin Ⅴ双染法才能检测出早期细胞凋亡率,有效鉴别细胞凋亡与死亡.

Objective To find out the dose-effect relationship between y-rays whole body irradiation （WBI） and the apoptotic rate of mice bone marrow cells, especially when mice suffered from a low level of irradiation. Methods Mice were killed at different time after Co^60 rays WBI, the bone marrow cells were isolated, the mononuclear was collected and resuspend in PBS, then stained with propidium iodide （PI） or PI/FIFC-Annexin Ⅴ, then analyzed with BD FACSAria flow cytometer,subsequently. Results The results of the experiment indicated that there were some differences between the change of apoptosis rate in the early phase and that of apoptosis in the late phase and cell death. According to the relationship between the irradiation dose rate and the apoptosis rate, we concluded that the biological effect induced by low dose rate irradiation was much less harmful than that after higher dose rate irradiation. However, all our inference should be further proved by more statistics and experimental results. Still we expected that the present findings would provide useful information in the health care of people who were sustaining exposed to low dose irradiation. Conclusion Compared to the high dose irradiation, unit dose irradiation at low dose caused higher apoptosis, so it was even useful for cleaning the injured cells and decreasing the harm to health. Only the PI/FITC-Annexin Ⅴ could detect the early apoptosis rate and identify the apoptosis and cell death.