Ling Xi, Zhang Guowei, Sun Lei, Wang Zhi, Zou Peng, Gao Jianfang, Peng Kaige, Chen Qing, Yang Huan, Zhou Niya, Cui Zhihong, Zhou Ziyuan, Liu Jinyi, Cao Jia, Ao Lin
Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
Department of Environmental Health, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
Environ Pollut. 2017 Jan;220(Pt A):680-687. doi: 10.1016/j.envpol.2016.10.026. Epub 2016 Oct 15.
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.
多环芳烃（PAHs）是广泛存在的环境污染物，对男性生殖功能有不良影响。许多研究证实，相对于核DNA，PAHs更倾向于在线粒体DNA中积累，并破坏线粒体功能。然而，接触PAHs是否与精子中的线粒体损伤和功能障碍相关尚不清楚。为了评估PAHs对精子线粒体的影响，我们在重庆大学生男性生殖健康（MARHCS）研究中测量了666名个体的线粒体膜电位（MMP）、线粒体DNA拷贝数（mtDNAcn）和mtDNA完整性。通过测量八种尿PAH代谢物（1-OHNap、2-OHNap、1-OHPhe、2-OHPhe、3-OHPhe、4-OHPhe、2-OHFlu和1-OHPyr）来估计PAHs暴露情况。根据尿PAH代谢物的三分位数水平将受试者分为低、中、高暴露组。在单变量分析中，结果显示2-OHPhe、3-OHPhe、∑Phe代谢物和2-OHFlu水平升高与精子mtDNAcn降低有关。在调整潜在混杂因素后，这些代谢物仍存在显著的负相关（分别为p = 0.039、0.012、0.01、0.035）。2-OHPhe、3-OHPhe、∑Phe代谢物和2-OHFlu每增加1μg/g肌酐，精子mtDNAcn分别下降9.427%、11.488%、9.635%和11.692%。尿PAH代谢物与精子MMP或mtDNA完整性之间无显著关联。结果表明，低水平的PAHs暴露可导致精子线粒体异常。
