title: Polycyclic aromatic hydrocarbons exposure decreased sperm mitochondrial DNA copy number: A cross-sectional study (MARHCS) in Chongqing, China.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that have adverse effects on the male reproductive function. Many studies have confirmed that PAHs preferentially accumulate in mitochondria DNA relative to nuclear DNA and disrupt mitochondrial functions. However, it is rare whether exposure to PAHs is associated with mitochondrial damage and dysfunction in sperm. To evaluate the effects of PAHs on sperm mitochondria, we measured mitochondrial membrane potential (MMP), mitochondrial DNA copy number (mtDNAcn) and mtDNA integrity in 666 individuals from the Male Reproductive Health in Chongqing College Students (MARHCS) study. PAHs exposure was estimated by measuring eight urinary PAH metabolites (1-OHNap, 2-OHNap, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe, 2-OHFlu and 1-OHPyr). The subjects were divided into low, median and high exposure groups using the tertile levels of urinary PAH metabolites. In univariate analyses, the results showed that increased levels of 2-OHPhe, 3-OHPhe, ∑Phe metabolites and 2-OHFlu were found to be associated with decreased sperm mtDNAcn. After adjusting for potential confounders, significantly negative associations of these metabolites remained (p = 0.039, 0.012, 0.01, 0.035, respectively). Each 1 μg/g creatinine increase in 2-OHPhe, 3-OHPhe, ∑Phe metabolites and 2-OHFlu was associated with a decrease in sperm mtDNAcn of 9.427%, 11.488%, 9.635% and 11.692%, respectively. There were no significant associations between urinary PAH metabolites and sperm MMP or mtDNA integrity. The results indicated that the low exposure levels of PAHs can cause abnormities in sperm mitochondria.
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Ling
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zou
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Jianfang
authors.initials: J
authors.lastname: Gao
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Kaige
authors.initials: K
authors.lastname: Peng
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Yang
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Niya
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Department of Environmental Health, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Ziyuan
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Jinyi
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Cao
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China. Electronic address: aolin117@163.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Ao
mesh_terms: D000328:Adult; D002681:China; D003430:Cross-Sectional Studies; D056915:DNA Copy Number Variations / Q000187:drug effects*; D004272:DNA, Mitochondrial / Q000187:drug effects* / Q000235:genetics; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000633:toxicity*; D004787:Environmental Pollution / Q000032:analysis; D006801:Humans; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000235:genetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity* / Q000652:urine*; D013094:Spermatozoa / Q000187:drug effects*; D055815:Young Adult
chemical_list: D004272:DNA, Mitochondrial; D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons
keywords: Mitochondrial DNA copy number; Mitochondrial DNA integrity; Mitochondrial membrane potential; Polycyclic aromatic hydrocarbons; Sperm; Urinary metabolites