中文摘要：

目的探讨苯并芘（Benzo[a]pyrene,BaP）作用下的人支气管上皮细胞（16HBE）热休克蛋白70（Heatshock protein 70,Hsp70）和着色性干皮病G蛋白（Xeroderma pigmentosum group G,XPG）表达的时间效应特征,并分析二者之间可能存在的关联性。方法用8μmol/L BaP处理16HBE细胞0、1、2、4、8、12、24和48 h,以彗星实验检测细胞DNA损伤并以Olive尾矩值（Olive Tail Moments,OTM）评价DNA损伤程度,以Western-blot检测Hsp70和XPG的表达水平,并以激光共聚焦法检测二者的共定位。结果染毒1～2h时OTM值变化率最大,与正常细胞相比,除染毒1h组外其余各组OTM值均显著性增高（P﹤0.01）;Hsp70和XPG的表达随染毒时间逐渐增高,12 h时达到峰值,激光共聚焦结果显示BaP染毒细胞后Hsp70和XPG的结合在细胞核内增强。结论在该试验条件下,XPG在执行核苷酸切除修复作用时可能有Hsp70的参与,其具体机制还有待其他实验进一步加以证实。

英文摘要：

Objective To investigate the dynamic changes and interactions of Hsp70 and XPG in human bronchial cells treated with BaP.Methods The human bronchial epithelial cells were treated with 8μmol /L BaP for 0,1,1,2,4,8,12,24 and 48 h.The levels of DNA damage were evaluated by the Olive Tail Moments（OTM）.The levels of protein expressions were detected by Western-blot and the co-localization was evaluated by cofocal.Results The OTM dramatically increased from 1 to 2 h.Compared to the control,the extent of DNA damage significantly increased in cells except for treated with BaP for 1 h（P ﹤ 0.01）.The levels of Hsp70 and XPG significantly increased and peaked at 12th hours in cells treated with 8 μmol /L BaP.Confocal microscopy demonstrated increased co-localization of Hsp70 with XPG in nuclei of cells treated with BaP.Conclusion These results suggested that Hsp70 might play a role in nucleotide excision repair.However,the mechanisms underlying this observation need further investigation.