title: Mitochondrial DNA hypomethylation in chrome plating workers.
abstract: A matched case-control study was conducted to examine the relationship between chromium (Cr) exposure and variation in mitochondrial (mt) DNA methylation. We enrolled 29 pairs of subjects in this study; Cr exposure was confirmed in the cases by detecting blood Cr and other metal ion concentrations. DNA damage caused by Cr exposure was determined in terms of binucleated micronucleus frequency (BNMN) and mtDNA copy number. Finally, a Sequenom MassARRAY platform was applied to inspect the DNA methylation levels of mitochondrially encoded tRNA phenylalanine (MT-TF), mitochondrially encoded 12S RNA (MT-RNR1), and long interspersed nucleotide element-1 (LINE-1) genes. The blood Cr ion concentration and micronucleus frequency of the Cr-exposed group were higher than those of the control group, whereas the mtDNA copy number remained unchanged. The methylation levels of MT-TF and MT-RNR1 but not LINE-1 were significantly lower in Cr-exposed workers. Pearson correlation analysis showed that workers with higher blood Cr ion concentrations exhibited lower MT-TF and MT-RNR1 gene methylation, and multiple linear regression analysis indicated that CpG sites 1 and 2 in MT-TF and CpG site 6 in MT-RNR1 were affected. These results suggested that methylation level of mtDNA has the possibility of acting as an alternative effect biomarker for Cr exposure.
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Linqing
authors.initials: L
authors.lastname: Yang
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Xia
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Disease, Shenzhen 518001, China.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Shenzhen Longgang District Center for Disease Control and Prevention, Shenzhen 518172, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Ding
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Desheng
authors.initials: D
authors.lastname: Wu
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan 430065, China.
authors.forename: Gaofeng
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China. Electronic address: zxzhuang2007@126.com.
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: Zhuang
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002857:Chromium / Q000097:blood / Q000633:toxicity*; D056915:DNA Copy Number Variations; D004249:DNA Damage / Q000187:drug effects; D019175:DNA Methylation; D004272:DNA, Mitochondrial; D005260:Female; D006801:Humans; D020084:Long Interspersed Nucleotide Elements; D008297:Male; D015162:Micronucleus Tests; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D004272:DNA, Mitochondrial; D002857:Chromium
keywords: Biomarker; Chromium; DNA methylation; Mass-ARRAY; Occupational exposure