X射线对人外周血淋巴细胞DNA损伤修复和凋亡的影响

目的 研究不同时间诱导X射线照射的淋巴细胞进入细胞周期DNA损伤修复与凋亡的影响.方法 X射线（0.5 Gy）作用于正常人外周血淋巴细胞,以照射后不同时间点（0、4 h）分别加入PHA并分成两组,即照射后0 h加PHA组（A组）和照射后4 h加PHA组（B组）,再分别培养0、0.5、2 h,用流式细胞术和免疫印迹法检测A组和B组γ-H2AX蛋白的表达,Annexin-V/PI法分析A、B两组的细胞凋亡率.结果 流式细胞术及免疫印迹结果均显示A组的γ-H2AX蛋白表达高于B组（P＜0.05）,且均先升高后降低.A组细胞凋亡率亦大于B组.结论 不同时间诱导被打击的淋巴细胞进入周期其可能发生DNA修复并同时伴随细胞凋亡的发生.

Influence of X-ray irradiation on DNA Damage Repair and Apoptosis in Peripheral Blood Lymphocytes

Objective To investigate the effect of X-ray irradiation on DNA damage repair and apoptotic ratio in normal peripheral blood lymphocytes at difterent time points of addition of Phytohemagglatinin. Methods Phytohemagglutinin was added to lymphocytes at 0 h and 4 h after exposure to 0.5 Gy X- irradiation. Peripheral blood lymphocytes （PBLs） were divided into two groups, group A treated with PHA 0 h after irradiation and group B treated with PHA group 4 h after irradiation, and then incubated liar 0 h, 0.5 h and 2 h, respectively. Flow cytometry analysis and Western blotting were used to analyze the expression of γ-H2AX in the two groups. Apoptosis between the two groups was detected with annexinV-FITC/propidium iodide （PI） staining assay. Results Results of flow cytometry analysis and Western blot showed that 7-H2AX expression level in group A was generally higher than that in group B at either 0. 5 h or2 h time point （P〈0. 05）, with a decrease at 2 h after irradiation. The apoptosis rate of group A was higher than that of group B. Conclusion Induction with phytohemagglutinin at different time points after X- irradiation of peripheral blood lymphocytes can repair the damaged lymphocytes, accompanied with oecurrence of apoptosis.