CAJ | 학술논문

目的通过比较γ射线照射诱导大鼠和人淋巴细胞DNA双链断裂(DSBs)修复动力学的变化,评价大鼠用于γ-H2AX焦点辐射生物剂量计动物模型的可行性.方法采用γ射线外照射Sprague-Dawley (SD)雄性大鼠和健康成人外周血淋巴细胞以及整体照射大鼠,分别于照射后不同时间采用免疫荧光技术检测DSBs分子标志物γ-H2AX焦点的变化,检测修复蛋白pATM(S1981)和pDNA-PKcs(T2609)焦点的形成,以及它们与γ-H2AX焦点的共定位情况.结果 0.5 Gyγ射线照射诱发大鼠和人淋巴细胞γ-H2AX焦点形成和消除动力学相一致,表现为受照后30 min,γ-H2AX焦点形成达到最大值(t大鼠=62.64,t人=28.52,P＜0.05),6h内快速下降(t大鼠=45.96,t人=14.80,P ＜0.05),至受照后24 h残留焦点数为最大值的3％～8％.γ射线照射后30 min,大鼠和人淋巴细胞pATM (S1981)和pDNA-PKcs(T2609)焦点形成数较未照射对照组显著增加(t大鼠=21.05、25.80,t人=11.07、29.52,P＜0.05),分别与γ-H2AX焦点共定位比例亦显著升高(t大鼠=5.34、9.14,t人=18.32、51.28,P＜0.05),占26％～ 32％.离体照射和整体照射诱导大鼠淋巴细胞γ-H2AX焦点形成数相一致,而且γ-H2AX焦点形成与照射剂量之间呈良好的线性关系.结论大鼠为γ-H2AX用于辐射生物剂量计研究提供了很好的动物模型,ATM与DNA-PKcs共激活在辐射诱导大鼠和人淋巴细胞DSBs的修复中发挥重要的作用.
목적 통과비교γ사선조사유도대서화인림파세포DNA쌍련단렬(DSBs)수복동역학적변화,평개대서용우γ-H2AX초점복사생물제량계동물모형적가행성.방법 채용γ사선외조사Sprague-Dawley (SD)웅성대서화건강성인외주혈림파세포이급정체조사대서,분별우조사후불동시간채용면역형광기술검측DSBs분자표지물γ-H2AX초점적변화,검측수복단백pATM(S1981)화pDNA-PKcs(T2609)초점적형성,이급타문여γ-H2AX초점적공정위정황.결과 0.5 Gyγ사선조사유발대서화인림파세포γ-H2AX초점형성화소제동역학상일치,표현위수조후30 min,γ-H2AX초점형성체도최대치(t대서=62.64,t인=28.52,P＜0.05),6h내쾌속하강(t대서=45.96,t인=14.80,P ＜0.05),지수조후24 h잔류초점수위최대치적3％～8％.γ사선조사후30 min,대서화인림파세포pATM (S1981)화pDNA-PKcs(T2609)초점형성수교미조사대조조현저증가(t대서=21.05、25.80,t인=11.07、29.52,P＜0.05),분별여γ-H2AX초점공정위비례역현저승고(t대서=5.34、9.14,t인=18.32、51.28,P＜0.05),점26％～ 32％.리체조사화정체조사유도대서림파세포γ-H2AX초점형성수상일치,이차γ-H2AX초점형성여조사제량지간정량호적선성관계.결론 대서위γ-H2AX용우복사생물제량계연구제공료흔호적동물모형,ATM여DNA-PKcs공격활재복사유도대서화인림파세포DSBs적수복중발휘중요적작용.
Objective To evaluate the potential feasibility of γ-H2AX foci as a biodosimetry after exposure to ionizing radiation by comparing DNA double-strand break repair kinetics in rat blood lymphocytes with that in human lymphocytes.Methods Peripheral blood lymphocytes separated from Sprague-Dawley(SD) male rats and healthy adults were exposed to γ-rays,and some rats were also subjected to total body irradiation.The inductions of DNA repair-related foci of γ-H2AX,pATM (S1981) and pDNA-PKcs (T2609) were detected with immunofluorescence staining technique at different time points post-irradiation,and the status of their co-localization was analyzed.Results The induction kinetics of γ-H2AX foci in rat lymphocytes was similar to that observed in human lymphocytes.The frequencies of γ-H2AX foci peaked at 30 min after γ-ray irradiation (trst =62.64,th =28.52,P ＜ 0.05),then decreased rapidly after 6 h post-irradiation (trat =45.96,th =14.80,P ＜0.05),and the residual foci number remained only about 3％-8％ of its maximal value at 24 h post-irradiation.At 30 min after γ-ray irradiation,the frequencies of pATM (S1981) and pDNA-PKcs (T2609) foci in rat and human lymphocytes significantly higher than those of nonirradiated control (trat =21.05,25.80,th =11.07,29.52,P ＜ 0.05),and the frequencies of co-localization of pATM (S1981) or pDNA-PKcs (T2609) foci with γ-H2AX foci also markedly increased by 26％-32％ in irradiated lymphocytes of rat and human (trat =5.34,9.14,thuman =18.32,51.28,P ＜0.05).Moreover,γ-H2AX foci incidence in rat lymphocytes in vitro was consistent with that induced by total body irradiation of rat.The number of γ-H2AX foci in irradiated rat lymphocytes increased with irradiation dose in a linear dose-dependent manner,its slope was similar to that of irradiated human lymphocytes reported by other laboratory.Conclusions Rat is a useful animal model to evaluate radiation biodosimetry with γ-H2AX foci in lymphocytes.The co-activation of ATM and DNA-PK plays an important role in DSB repair in the irradiated lymphocytes of rat and human.