【摘要】 目的研究热休克蛋白70(Hsp70)在苯并(a)芘(BaP)所致DNA损伤修复中的保护作用。方法转染人支气管上皮细胞(16HBE)含有Hsp70基因(hsp70)的质粒,以增高Hsp70的表达,以正常培养和转染载体质粒细胞作为对照,分别为Hsp70过表达组(16HBE/hsp70)、对照组(16HBE)和转染对照组(16HBE/pcDNA)。用16μmol BaP染毒上述3组细胞2 h,恢复不同的时间(0,2,4,8,24 h),碱性单细胞电泳(SCGE)检测DNA修复。转染被不同浓度(0,10,20,30,40μmol)BaP二氢二醇环氧化物(BPDE)损伤的荧光素酶报告基因质粒,检测不同组细胞对质粒的修复程度。以Olive尾距(OTMs)和相对荧光素酶活力评价DNA修复能力的差异。结果转染增高了Hsp70表达量约80%。3组细胞OTMs值均随恢复时间延长而降低。相对于对照组和转染对照组,Hsp70过表达组的OTMs值在恢复前2 h降低更迅速,且在恢复的各个时间点均小于对照组,差异均有统计学意义(P<0.01)。Hsp70过表达组的荧光素酶活力在恢复的各个时间点始终大于对照组和转染对照组,且在10μmol时,P<0.01,在20μmol时,P<0.05。结论Hsp70能促进细胞对BaP造成DNA损伤的修复更多还原

【Abstract】 Objective To explore the effects of Hsp70 on the repair of BaP-induced DNA damages.Methods 16HBE cells were transfected with plasmids harboring hsp70 gene to increase the expression of Hsp70.Cells cultured at normal condition and transfected with vectors were used as control.Then,3 groups of cells were exposed to 16 μmol BaP for 2 h and recovered for different time(0,2,4,8,24 h).Single cell gel electrophoresis(SCGE)was used to assess the DNA repair.In order to measure the difference in repair capacity in 3 group cells,the cells were also transfected with plasmids damaged by different concentrations of BaP(t)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide(BPDE)(0,10,20,30,40 μmol).Olive tail moments(OTMs)and relative activity of luciferase were applied to assess the difference in DNA repair capacity.Results Transfection increased the content of Hsp70 to 80%.The OTMs in 3 groups all decreased in the recovery period.Compared with other two groups,the OTMs in Hsp70 over-expression group decreased more rapidly in the first 2 h and remained lower throughout the whole recovery period(P<0.01).The luciferase activity in Hsp70 over-expression group was higher than that in two control groups,(P<0.01)for 10 μmol and(P<0.05) for 20 μmol.Conclusions Hsp70 could promote the repair of BaP-induced DNA damages.更多还原