交通污染暴露对DNA甲基化的影响  

Effects of Traffic-related Air Pollution Exposure on DNA Methylation

作　　者：汪婷[1] 丁锐[1] 黄丹妮[1] 祝子逸[2] 章军[3] 叶怀庄[4] 徐迎春[5] 金永堂[1] 

机构地区：[1]浙江大学公共卫生学院环境表观遗传实验室,杭州310058 [2]浙江大学医学院附属邵逸夫医院,杭州310058 [3]浙江大学公共卫生学院毒理学研究室,杭州310058 [4]浙江大学公共卫生实验教学中心,杭州310058 [5]浙江大学药学院生化药学研究室,杭州310058

出　　处：《环境科学》2017年第8期3529-3535,共7页Environmental Science

基　　金：国家自然科学基金项目(81372953;81673124)

摘　　要：探讨交通污染现场暴露对DNA甲基化的影响.30只8周龄Wistar大鼠按随机数字表法随机分5组,每组6只.其中3组分别在隧道(高暴露组)、路口(中暴露组)、校园(对照组)暴露7 d,另外2组分别在隧道暴露14 d/28 d.在暴露过程中检测3个暴露地点PM_(10)、NO_2的浓度.暴露实验分别在春季、秋季各进行一次.暴露结束后,焦磷酸测序法检测肺组织和血液中DNA(p53、MGMT、MAGE-A4)甲基化水平,并分析比较不同暴露组间DNA甲基化水平的差异.结果表明,PM_(10)、NO_2浓度均为隧道(高暴露组)>路口(中暴露组)>校园(对照组),差异具有统计学意义.秋季暴露7 d后,与对照组相比,肺组织中p53(P_(路口)=0.016;P_(隧道)=0.019)、MGMT(P_(路口)=0.002;P_(隧道)=0.003)启动子甲基化水平显著降低,随着暴露时间的增加,甲基化水平进一步降低;MAGE-A4启动子区处于高度甲基化状态,在肺组织和血液中,均未发现MAGE-A4启动子甲基化水平在三暴露组间存在显著的统计学差异.7d暴露对肺组织中DNA甲基化水平的影响更大,但随着暴露时间的增加,肺组织和血液中DNA甲基化水平改变模式趋于一致.Spearman相关分析结果显示,在肺组织中,PM_(10)和p53甲基化水平呈负相关关系(r=-0.347;P=0.038);NO_2和p53、MGMT、MAGE-A4甲基化水平均存在负相关(r值分别为-0.482、-0.444、-0.346,P值均<0.05).在血液中,MAGE-A4甲基化水平与PM_(10)、NO_2均呈正相关(r值分别为0.395、0.431,P值均<0.05).交通污染暴露会引起p53、MGMT启动子低甲基化.The goal of the present study was to explore the effects of traffic-related air pollution exposure on DNA methylation. Into five groups of 6,30 healthy Wistar rats were randomly divided. Three groups of rats were then exposed to traffic-related air pollution at high（ tunnel）,moderate（ crossroad）,and low（ control） pollution levels for 7 d,whereas the two other groups were exposed in the tunnel for 14 d/28 d. The levels of PM_（10） and NO_2 were measured during the exposure. The study was performed in spring and autumn,and lung tissue and blood were collected after the exposure. Promoter methylation levels of p53,MGMT,and MAGE-A4 were quantified via pyrosequencing. The levels of PM_（10） and NO_2 in the crossroad and tunnel groups were significantly higher than those in the control group. After 7 d exposure in autumn,promoter methylation levels of p53 and MGMT in lung tissue significantly decreased,and the methylation status continued to decrease with increasing exposure time; MAGE-A4 was highly methylated and showed no difference among the three groups. DNA methylation in lung tissue was more likely to be changed compared with that in blood during 7 d exposure. As the exposure time increased,DNA methylation changes between blood and lung tissue started to coincide. In lung tissue,PM_（10） exposure was significantly associated with decreased p53 promoter methylation（ r =-0. 347,P = 0. 038） and NO_2 exposure was significantly associated with decreased promoter methylation of p53,MGMT,and MAGE-A4（ r =-0. 482,-0. 444,and-0. 346,respectively; P〈0. 05）. In blood,PM_（10） and NO_2 were significantly and positively associated with MAGE-A4 promoter methylation（ r= 0. 395 and 0. 431,respectively; P〈0. 05）. Traffic-related air pollution exposure may induce promoter hypomethylation of p53 and MGMT.

关 键 词：交通污染 DNA甲基化 P53 MGMT 暴露 

分 类 号：X171.5[环境科学与工程—环境科学]