PM_(2.5)暴露对原代皮层神经元COX-2启动子区甲基化水平的影响  

Effect of PM_(2.5)exposure on methylation level in COX-2 promoter region of primary cortical neurons

作　　者：沈永梅 常晓菡 张倩文 李奔 仇玉兰[1] SHEN Yong-mei;CHANG Xiao-han;ZHANG Qian-wen;LI Ben;QIU Yu-lan(School of Public Health,Shanxi Medical University^Taiyuan Shanxi 030001,China)

机构地区：[1]山西医科大学公共卫生学院,山西太原030001

出　　处：《毒理学杂志》2022年第2期152-156,162,共6页Journal of Toxicology

基　　金：国家自然科学基金(21906100);山西省应用基础研究青年科技研究基金(201901D211333)。

摘　　要：目的探讨环氧化酶-2(COX-2)启动子区甲基化是否参与PM_(2.5)暴露诱导神经元COX-2表达升高的调控。方法培养小鼠原代皮层神经元细胞,进行PM_(2.5)(0、3、10和30μg/ml)染毒,采用蛋白免疫印记(Western blot)检测COX-2、DNA甲基转移酶(DNMT1、DNMT3a、DNMT3b)的蛋白表达,通过DNA甲基化定量检测试剂盒检测总甲基化改变,利用亚硫酸氢盐测序分析原代神经细胞COX-2启动子区的甲基化状态。结果原代皮层神经元于PM_(2.5)暴露24 h后,随着PM_(2.5)处理浓度的增加,COX-2蛋白表达水平呈剂量依赖性升高(P<0.05)。与对照组相比,PM_(2.5)暴露组的DNMT1蛋白表达升高,而DNMT3b蛋白表达降低(P<0.05),且中高剂量PM_(2.5)暴露组的神经元总甲基化水平升高(P<0.05),PM_(2.5)暴露组的DNMT3a蛋白表达以及COX-2启动子区的甲基化水平未见明显改变,差异无统计学意义(P>0.05)。结论COX-2启动子区甲基化未参与PM_(2.5)暴露诱导神经元COX-2表达升高的调控。Objective To investigate whether the methylation of Cyclooxygenase-2(COX-2)promoter region is involved in the regulation of increased expression of COX-2 in neurons induced by PM_(2.5)exposure.Methods The primary cortical neurons of mice were cultured and treated with PM_(2.5)(0,3,10,30μg/ml).We used Western blot to detect the expressions of COX-2 protein and DNA methyltransferases(DNMT1,DNMT3 a and DNMT3 b),and used DNA methylation quantitative detection kits to detect the changes of total methylation.Furthermore,the methylation status of COX-2 promoter in primary nerve cells was also analyzed by bisulfite sequencing.Results When primary cortical neurons were exposed to PM_(2.5)for 24 h,the expression of COX-2 protein increased with the increased exposure concentrations of PM_(2.5)in a dose-dependent manner(P<0.05).Compared with the control group,PM_(2.5)exposure increased the expression of DNMT1 protein,but interestingly,the expression of DNMT3 b protein decreased(P<0.05).And the total methylation level of neurons increased in the medium and high dose PM_(2.5)exposure group(P<0.05).However,compared with the control group,there were no significant changes about the expression of DNMT3 a protein and methylation level of COX-2 promoter in PM_(2.5)exposed groups(P>0.05).Conclusion The methylation of COX-2 promoter region did not participate in the regulation of increased expression of COX-2 induced by PM_(2.5)exposure in neurons.

关 键 词：细颗粒物 环氧化酶-2 DNA甲基化 DNA甲基转移酶 

分 类 号：R99[医药卫生—毒理学] R122.7[医药卫生—药学]