职业性砷暴露对尿砷及外周血miRNA的影响

Effects of occupational exposure to arsenic on urinary arsenic and miRNA in peripheral blood

目的探讨职业性砷暴露工人尿中不同化学形态砷含量及甲基化能力与外周血miRNA的关系。方法采用自身对照,选取某矿山55名工人,问卷收集基本信息;采集研究对象正在接触时与脱离接触3个月后的尿液和外周血,高效液相色谱-电感耦合等离子质谱联用(HPLC-ICP-MS)法检测尿中三价及五价无机砷(inorganic arsenic,iAs^(3+)、iAs^(5+))、一甲基砷酸(monomethylarsonic acid,MMA)、二甲基砷酸(dimethylarsinic acid,DMA)的含量;以尿中四种形态砷含量总和为总砷(total arsenic,tAs),并以一甲基化率(primary methylated index,PMI)、二甲基化率(secondary methylated index,SMI)为指标,计算甲基化能力;同时,采用实时荧光定量PCR检测外周血miR-155、miR-191、miR-200b相对表达量。结果正在接触时工人尿中iAs^(3+)、MMA、DMA、iAs^(5+)、tAs浓度均与脱离接触后有差异,无机砷百分比(iAs%)、一甲基砷百分比(MMA%)、二甲基砷百分比(DMA%)、PMI和外周血miR-200b相对表达量(2^(-△△Ct))均与脱离接触后差异具有统计学意义(t=-2.476,P<0.05);此外,尿中MMA、DMA和tAs与外周血miR-155和miR-200b的相对表达量相关,PMI与miR-155相关,差异具有统计学意义(P<0.05)。结论外周血miR-155、miR-200b与尿砷代谢产物有关,miR-200b水平可以反映尿砷代谢物含量高低,在砷体内代谢转化过程的miRNA表达中具有重要意义。

Objective To explore the relationship between urinary arsenic content of its different chemical forms,and the ability of methylation metabolism and the peripheral blood miRNA in occupational arsenic exposed workers.Methods Using self-control,a total of 55 mining workers were selected and the basic information was collected by questionnaire,the urine and peripheral blood of the subjects were collected when they were in contact and three months later after they were out of contact.High performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP-MS)was used to detect the trivalent and pentavalent inorganic arsenic(iAs^(3+),iAs^(5+)),the monomethylarsonic acid(MMA)and the dimethylarsinic acid(DMA);the total arsenic(tAs)was calculated by taking the sum of the four forms of arsenic in urine,and the methylation ability was assessed using the primary methylated index(PMI)and secondary methylated index(SMI);at the same time,the relative expression content of miR-155,miR-191 and miR-200b in peripheral blood of the subjects were detected by real-time PCR.Results The results showed that the urinary concentrations of iAs^(3+),MMA,DMA,iAs^(5+)and tAs in the exposing workers were significantly different from that of disengaged exposure,the percentages of the inorganic arsenic(iAs%),the monomethylarsenic(MMA%),the dimethylarsenic(DMA%),PMI and the relative expression of miR-200b in peripheral blood(2^(-△△Ct))of exposing workers were all significantly different from that of disengaged exposure(t=-2.476,P<0.05).In addition,urinary MMA,DMA and tAs were correlated with the relative expression of miR-155 and miR-200b,and PMI was correlated with miR-155,the difference was statistically significant(P<0.05).Conclusion The results suggested that miR-155 and miR-200b were related to urinary arsenic metabolites,the level of miR-200b could reflect the level of urinary arsenic metabolites,and the processes of metabolism and transformation of arsenic in vivo plays an important role in miRNA expression.