低剂量电离辐射对人淋巴细胞氧化应激及DNA损伤的影响  

Effect of low-dose ionizing radiation on oxidative stress and DNA damage repair in human lymphocytoid cells

作　　者：孙鑫 李爽[1] 陆雪[1] 蔡恬静[1] 刘雅[1] 刘青杰[1] 张伟[1] SUN Xin;LI Shuang;LU Xue;CAI Tianjing;LIU Ya;LIU Qingjie;ZHANG Wei(China CDC Key Laboratory of Radiological Protection and Nuclear Emergency,National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention,Beijing 100088,China)

机构地区：[1]中国疾病预防控制中心辐射防护与核安全医学所,辐射防护与核应急中国疾病预防控制中心重点实验室,北京100088

出　　处：《癌变．畸变．突变》2024年第2期94-99,共6页Carcinogenesis,Teratogenesis & Mutagenesis

基　　金：国家自然科学基金(82173464)。

摘　　要：目的:探讨低剂量^(137)Cs γ射线照射后正常人淋巴细胞(AHH-1)是否产生氧化应激及DNA损伤,并引发DNA修复。方法:以剂量率为8.32 mGy/min的^(137)Cs γ射线照射AHH-1细胞,剂量分别为0(未照射)、0.01、0.02、0.05、0.075、0.1和0.2 Gy,照射后分别培养1、24、48和72 h。采用CCK-8试剂盒检测细胞存活率变化;丙二醛(MDA)、超氧化物歧化酶(SOD)和活性氧(ROS)试剂盒检测细胞氧化损伤水平;免疫荧光方法分析γH2AX和53BP1焦点形成情况;实时荧光定量PCR方法检测DNA损伤修复相关基因CDKN1A、DDB2和POLH的mRNA表达水平变化。结果:与未照射组相比,照射后24和48 h,各剂量组细胞存活率显著增强(P<0.05);照射后48 h,MDA水平和SOD活性在0.2 Gy剂量组发生显著变化(P<0.05);0.02~0.075 Gy和0.2 Gy剂量组ROS相对荧光强度显著升高(P<0.05);0~0.2 Gy γ射线照后1 h,γH2AX和53BP1焦点数量随剂量增加而增加,且具有明显的剂量-效应关系(P<0.01);与未照射组相比,照射后48 h,DDB2和POLH mRNA相对表达水平显著升高,差异具有统计学意义(P<0.05)。结论:低剂量电离辐射引起人淋巴细胞产生氧化应激和DNA损伤,并促进DNA损伤修复相关基因在转录水平发生改变。OBJECTIVE:To investigate effect of low-dose ^(137)Csγ-irradiation on oxidative stress,DNA damage repair and indued DNA damage in normal human lymphocytoid cells(AHH-1).METHODS:AHH-1 cells were irradiated with ^(137)Csγ-rays at a dose rate of 8.32 mGy/min,with doses of 0(unirradiated),0.01,0.02,0.05,0.075,0.1,and 0.2 Gy,and cultured for 1,24,48 and 72 h after irradiation,respectively.Cell viability was examined by a CCK-8 kits.The level of oxidative damage was detected by malondialdehyde(MDA),superoxide dismutase(SOD)and reactive oxygen species(ROS)kits.γH2AX and 53BP1 foci were performed by immunofluorescence.Changes in the expression levels of DNA damage repair-related genes CDKN1A,DDB2 and POLH mRNA were detected by real-time fluorescence quantitative PCR.RESULTS:Compared with the unirradiated group,cell viability were significantly increased at 24 and 48 h after irradiation(P<0.05).The differences in MDA levels and SOD activities were changed significantly in the 0.2 Gy(P<0.05);the relative fluorescence intensity of ROS was significantly increased in the doses of 0.02,0.05,0.075 Gy and 0.2 Gy at 48 h after irradiation.The number ofγH2AX and 53BP1 focus increased with the doses,and there were good dose-response relationships at 1 h following radiation exposure(P<0.01).Compared with the unirradiated group,the relative mRNA expression level of DDB2 and POLH genes were significantly up-regulated at 48 h after irradiation(P<0.05).CONCLUSION:Exposure to low-doses of ionizing radiation induced changes in oxidative stress,DNA damage and expression of DNA damage repair-related genes in AHH-1 cells.

关 键 词：电离辐射 Γ射线 人淋巴细胞 氧化应激 DNA损伤 细胞增殖 

分 类 号：Q691.5[生物学—生物物理学]