双酚A对纳米二氧化钛理化特性及其DNA损伤效应的影响  

Impacts of Bisphenol A on Physicochemical Properties and DNA Damage Effects of Titanium Dioxide Nanoparticles on Human Embryo Liver Cell

作　　者：刘燕婕[1,2] 张艳红[2] 吕斌[2] 

机构地区：[1]长江航运总医院/武汉脑科医院检验科,武汉430015 [2]华中科技大学公共卫生学院,武汉430030

出　　处：《生态毒理学报》2015年第2期224-229,共6页Asian Journal of Ecotoxicology

基　　金：国家863项目(No.2012AA06A304);国家自然科学基金项目(No.21277054);交通运输部长江航务管理局科技项目(No.201410015)

摘　　要：纳米二氧化钛(nano-Ti O2)应用领域广泛,由于其对有机物或生物分子有吸附作用,二者相互反应,对各种细胞可能产生与nano-Ti O2单独作用时不同的毒性作用。为探讨双酚A(BPA)对nano-Ti O2理化性质的影响,以及BPA和nano-Ti O2联合暴露对人胚肝L-02细胞的DNA损伤效应。用不同缓冲液,测定不同浓度的BPA(0、0.1、1、10 mol·L-1)对不同浓度nano-Ti O2(0、0.1、1、10 mg·L-1)的粒径、表面电位和吸附能力的影响;然后测定不同浓度BPA和nano-Ti O2联合暴露对人胚肝L-02细胞DNA双链断裂、DNA损伤关键修复酶h Msh2基因(h Msh2)、O6-甲基鸟嘌呤甲基转移酶(MGMT)和DNA依赖蛋白激酶复合物催化亚基(DNA-PKcs)的m RNA表达水平表达的影响。结果表明在不同缓冲液中,随着BPA浓度的增加,nano-Ti O2粒径增加,表面电位上升,在细胞培养液DMEM中这一变化趋势最为明显;但在不同缓冲液中nano-Ti O2对BPA的吸附能力无明显差异。单独nano-Ti O2暴露不引起DNA双链断裂,对DNA损伤修复关键酶的表达也无明显影响,但nano-Ti O2可加重BPA的DNA双链断裂效应。与相应剂量的BPA单独染毒组比较,nano-Ti O2与BPA混合染毒组的细胞DNA双链断裂损伤加重(P<0.05),h Msh2、MGMT和DNA-PKcs的基因表达水平明显上升(P<0.05)。上述研究结果显示BPA可促进nano-Ti O2团聚,但团聚的nano-Ti O2仍可吸附BPA。单独nano-Ti O2暴露无DNA损伤作用,但nano-Ti O2可加重BPA的DNA双链断裂效应。其中h MSH2、MGMT和DNA-PKcs都参与2种污染物联合暴露所致的DNA损伤修复。Titanium dioxide nanoparticles （nano-TiO2） have been used widely and may react with a wide range of organic and biological molecules and then exhibit toxic effects in various cell lines, with or without photo activation. The effects of the interaction of TiO2 nanoparticles （nano-TiO2） with bisphenol A （BPA） on their physicochemical properties and DNA damage effects in human embryo L-02 hepatocytes were evaluated. Different concentrations of BPA （0, 0.1, 1, 10 μmol.L-1） and nano-TiO2 （0, 0.1, 1, 10 mg.L-1） were mixed to analyze the size distribution, zeta potential and adsorption capacity of nano-TiO2 in different media. Then L-02 cells were exposed to different concentration of BPA （0, 0.1, 1, 10 μmol.L-1） and nano-TiO2 （0, 0.1, 1, 10 mg.L-1） for 24 hours, respectively. DNA damage and the expression of DNA repair enzymes O6-methylguanine-DNA methyltransferase （MGMT）, DNA-dependent protein kinase catalytic subunit （DNA-PKcs） and hMSH2 in L-02 cells were analyzed. Results indicated that addition of BPA to nano-TiO2 dispersions increased the aggregation level and zeta potential of nano-TiO2 in all media. Nano-TiO2 had a similar adsorption capacity in different media, although a higher aggregation level was observed in cell culture medium. Obviously, Interactions of nano-TiO2 with BPA increased agglomeration and zeta potential, but did not influence the adsorption capacity of nano-TiO2. The aggregated nano-TiO2 can enrich BPA effectively. Toxicity analysis showed that nano-TiO2 did not induce significant DNA damage, but the mixture ofnano-TiO2 and BPA increased DNA double strand breaks and the expression of three DNA repair enzymes. It is clear that BPA and nano-TiO2 mixture induce synergistic DNA damage effects. And hMSH2, MGMT and DNA-PKcs all participated in the DNA damage repair pathway induced by the mixture of BPA and nano-TiO2.

关 键 词：纳米二氧化钛 双酚A 理化性质 联合暴露 DNA损伤 

分 类 号：X171.5[环境科学与工程—环境科学]