癌变·畸变·突变 ›› 2017, Vol. 29 ›› Issue (3): 189-193.doi: 10.3969/j.issn.1004-616x.2017.03.006

• 论著 • 上一篇    下一篇

叶酸对1,3-丁二烯诱发的小鼠DNA低甲基化和染色体损伤的影响

王治1,2, 凌曦1, 张国伟1, 高建芳1, 邹鹏1, 井澈1, 林哲韬1, 刘晋祎1, 曹佳1, 敖琳1   

  1. 1. 第三军医大学军事预防医学院毒理学研究所, 重庆 400038;
    2. 济南军区联勤部疾病预防控制中心, 山东 济南 250014
  • 收稿日期:2016-09-09 修回日期:2017-01-17 出版日期:2017-05-31 发布日期:2017-05-31
  • 通讯作者: 敖琳,E-mail:aolin117@163.com E-mail:aolin117@163.com
  • 作者简介:王治,E-mail:15098908000@163.com。
  • 基金资助:
    国家自然科学基金(81273105);重庆市自然科学基金(cstc2012jj A10080)

Effect of folic acid on DNA demethylation and chromosomal damage in mice after their inhalation exposure to 1, 3-butadiene

WANG Zhi1,2, LING Xi1, ZHANG Guowei1, GAO Jianfang1, ZOU Peng1, JING Che1, LIN Zhetao1, LIU Jinyi1, CAO Jia1, AO Lin1   

  1. 1. Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038;
    2. Prevention and Control Center of Jinan Military Command Disease, Jinan 250014, Shandong, China
  • Received:2016-09-09 Revised:2017-01-17 Online:2017-05-31 Published:2017-05-31

摘要: 目的:探讨叶酸(FA)对1,3-丁二烯(BD)诱发的小鼠遗传损伤和DNA甲基化改变的保护作用。方法:雄性昆明小鼠喂养相应饲料3周建立叶酸正常组(FA-C)、叶酸缺乏组(FA-D)以及叶酸补充组(FA-S)动物模型,每组小鼠18只,再随机分为对照组、BD低剂量和高剂量染毒组(0、13.82、1 382.14 mg/m3),染毒组小鼠每天吸入染毒6 h,每周5 d,连续染毒2周。采用酶联免疫吸附测定法(ELISA)检测小鼠血清中FA浓度和肝组织基因组DNA总体甲基化水平,荧光定量PCR检测DNA甲基转移酶DNMT1和DNMT3a mRNA的表达,胞质分裂阻滞微核试验分析外周血淋巴细胞的染色体损伤。结果:动物喂养3周后,与FA-C组相比,FA-D组血清FA浓度显著降低,FA-S组显著升高。在相同FA处理条件下,随BD染毒剂量升高,小鼠肝组织基因组DNA甲基化水平及甲基转移酶表达出现降低趋势,微核、核质桥及核芽突比率显著升高。在相同BD染毒条件下,与FA-C组比较,FA-D组的DNA甲基化水平和DNMT1、DNMT3a的mRNA表达出现下降趋势,而微核率等染色体损伤出现升高趋势;相反,FA-S组的DNA甲基化水平及DNMT1、DNMT3a的mRNA表达出现升高趋势,染色体损伤出现降低趋势,尤其在高剂量BD染毒条件下,叶酸补充对上述指标的影响均存在显著性差异(P < 0.05或0.01)。结论:BD可诱导小鼠的DNA低甲基化改变及染色体损伤,叶酸缺乏可加重BD所致DNA低甲基化和遗传损伤,而补充叶酸则对BD诱导的甲基化改变和遗传损伤具有保护效应。

关键词: 叶酸, 1, 3-丁二烯, DNA甲基化, 胞质分裂阻滞微核试验

Abstract: OBJECTIVE:To explore the effect of folic acid (FA) on genetic damage and DNA methylation which were induced by 1,3-butadiene (BD) in mice. METHODS:Male Kunming mice were fed with corresponding diets for 3 weeks to establish FA-C (normal folic acid group),FA-D (folic acid deficiency group) and FA-S (folic acid supplementation group) animal models. Then,each group of FA-treated mice was randomly divided into control,and BD low-and high-dose groups (0,13.82,1 382.14 mg/m3) and treated with the corresponding dosages of BD by inhalation for 2 weeks (6 h/d,5 d/week). Enzyme-linked immunosorbent assay (ELISA) was applied to detect the concentrations of FA in serum and genomic DNA methylation levels in liver tissue. The expression of methyltransferase DNMT1 and DNMT3a was quantified by qPCR and chromosomal damage in peripheral blood lymphocytes was detected by cytokinesis-block micronucleus test (CBMNT). RESULTS:After 3 weeks of FA treatment,the concentrations of serum folic acid were significantly lower in FA-D group but higher in FA-S group compared with the FA-C group. With increase of the BD doses,methylation of global DNA and expression of methyltransferase were decreased while the frequencies of micronuclei,nucleoplasmic bridge and nuclear bud were increased within the same FA treated group. On the other hand,under the same BD exposure conditions,FA-D group showed a decreased level of DNA methylation and methyltransferase expression and increased chromosomal damage while FA-S group resulted in an increased level of DNA methylation and mRNA level of methyltransferase 1,3a expression and decreased micronucleus rate of chromosome compared with FA-C group,especially in the high dose BD exposure conditions (P < 0.05 or 0.01). CONCLUSION:BD can induce global DNA demethylation and chromosomal damage in mice. Folic acid deficiency can aggravate the BD-induced abnormalities. However,folic acid supplementation has a protective effect against the BD-induced abnormalities.

Key words: folic acid, 1, 3-butadiene, DNA methylation, cytokinesis-block micronucleus test

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