摘要
目的探讨DNA聚合酶β(polβ)的表达水平在氢醌(HQ)遗传毒性中的作用。方法以polβ野生型(polβ+/+)、polβ缺陷型(polβ-/-)及polβ高表达型(polβoe)小鼠胚胎成纤维细胞为研究对象,采用四氮唑盐比色法检测HQ对3种细胞的毒性效应;2’,7’-二氯双氢荧光素双乙酸酯(DCFH-DA)法检测不同浓度HQ染毒后细胞内活性氧(ROS)的含量;彗星试验分析HQ诱导的3种细胞的DNA损伤及修复效应的差异;体外微核试验检测3种细胞微核率。结果随着HQ浓度的增加,3种细胞的存活率均下降,IC50以polβoe细胞最高,polβ+/+细胞次之,polβ-/-细胞最低,差异有统计学意义(P<0.05);3种细胞内ROS水平随HQ浓度的增加而上升,相同HQ浓度下polβ-/-细胞内ROS水平显著高于polβ+/+细胞(P<0.05);彗星试验显示HQ作用后3种细胞均有不同程度DNA损伤,在相同HQ染毒剂量下polβ-/-细胞损伤较polβ+/+细胞和polβoe细胞严重,而polβoe细胞损伤最为轻微;损伤修复效应显示polβoe细胞修复最快,polβ-/-细胞更不易修复;HQ可诱导3种细胞微核率增加,在相同HQ作用剂量下polβ-/-细胞的微核率最高,polβ+/+细胞次之,polβoe细胞最低,差异有统计学意义(P<0.05)。结论 HQ可诱导细胞内ROS的产生,从而导致DNA和染色体水平的氧化损伤,表现出其遗传毒效应,polβ可以提高细胞应对氧化损伤的能力,从而对HQ的遗传毒性效应起到一定的保护作用。
Objective To explore the effect of DNA polymerase β（pol β） expression level on genotoxicity in mouse fibroblast cell induced by hydroquinone（HQ）.Methods pol β wild-type cells（pol β ＋ ＋）,pol β null cells（pol β--） and pol β overexpressed cells（pol β oe） were applied as a model cell system.At various concentration of HQ,the cell cytotoxicities were detected by MTT assay.The DCFH-DA fluorescent probe was used to examine the cellular ROS levels.The effects of DNA damage /repair and chromosomal damage were observed by comet assay and micronuleus assay respectively.Results MTT assay showed that the doses of HQ increased,the cells viabilities were decreased.The concentrations of HQ that inhibited cell growth by 50%（IC50） in the pol β--cell were more lower than those of other cells（P 0.05）.The cellular ROS level in the three kinds of cells were increased in a concentration dependent way after treated with HQ and it was more stronger in pol β--cell than those in other two kinds of cells（P 0.05）.Comet assay and micronucleus assay showed that HQ induced DNA damage and increased micronucleus formation.DNA and chromosomal damage of pol β--cell were more serious than those of other cells.The DNA damage repair capacities of pol β oe cell were more stronger than pol β ＋ ＋ and pol β--cells.Conclusion Cellular ROS generation could be effectively induced by HQ,leading to DNA and chromosomal damage,pol β overexpression could help cells response to oxidative damage and protect cells from genotoxicity induced by HQ.
出处
《卫生研究》
CAS
CSCD
北大核心
2010年第6期669-673,共5页
Journal of Hygiene Research
基金
国家自然科学基金资助项目(No.30872079)
作者简介
陈晨，女，硕士研究生，研究方向：环境毒理学
通讯作者：张遵真，女，教授，研究方向：环境毒理学，E-mail：zhangzunzhen@163．com
