WHO Collaborating Center for Research in Human Reproduction, Shanghai, China; Key Laboratory of Contraceptive Drugs and Devices of NPFPC, Shanghai Institute of Planned Parenthood Research, Shanghai, China.
Andrology. 2014 Jan;2(1):138-44. doi: 10.1111/j.2047-2927.2013.00166.x. Epub 2013 Dec 1.
Bisphenol A (BPA) is an endocrine disruptor with potentially harmful effects on humans. However, epigenetic mechanisms that modulate the effects of BPA remain unclear. Methylation of long interspersed nucleotide elements (LINE-1) is a marker of genome-wide methylation status. This study aims to examine whether BPA exposure was associated with LINE-1 methylation changes in men. Male factory workers in Hunan, China (N = 149) were studied, 77 with BPA exposure in workplace (BPA-exposed group) and 72 without BPA exposure in workplace (control group). Pre-shift and post-shift urine samples were collected from the BPA-exposed group and spot urine samples were collected from the control group. Urine samples were assessed for BPA. In addition, blood and semen samples were collected from both groups for LINE-1 methylation analysis. In multivariate analysis adjusted for age, education, smoking habits and alcohol consumption, sperm LINE-1 methylation level was significantly lower in BPA exposed workers (p < 0.001) compared to that in the unexposed workers. Linear regression analysis also showed that log-transformed urine BPA levels were inversely associated with sperm LINE-1 methylation (p < 0.0001), but not peripheral blood cell LINE-1 methylation. Moreover, the association between urine BPA level and semen quality was not attenuated after adjustments for LINE-1 level. In summary, the observed independent relationship between BPA exposure and LINE-1 methylation may have public health implications on reproductive health in men because of ubiquitous exposure to BPA.
双酚 A (BPA) 是一种内分泌干扰物，对人类可能有潜在的危害。然而，调节 BPA 作用的表观遗传机制尚不清楚。长散布核苷酸元件 (LINE-1) 的甲基化是全基因组甲基化状态的标志。本研究旨在探讨 BPA 暴露是否与男性的 LINE-1 甲基化变化有关。研究对象为中国湖南的男性工厂工人（N=149），其中 77 人在工作场所接触 BPA（BPA 暴露组），72 人在工作场所未接触 BPA（对照组）。采集 BPA 暴露组工人的班前和班后尿液样本，采集对照组工人的随机尿液样本。检测尿样中的 BPA。此外，采集两组工人的血液和精液样本进行 LINE-1 甲基化分析。在调整年龄、教育程度、吸烟习惯和饮酒量等因素的多变量分析中，与未暴露组相比，BPA 暴露组工人的精子 LINE-1 甲基化水平显著降低（p<0.001）。线性回归分析还表明，尿 BPA 水平的对数与精子 LINE-1 甲基化呈负相关（p<0.0001），但与外周血细胞 LINE-1 甲基化无关。此外，调整 LINE-1 水平后，尿 BPA 水平与精液质量之间的关联并未减弱。总之，观察到的 BPA 暴露与 LINE-1 甲基化之间的独立关系可能对男性生殖健康具有公共卫生意义，因为 BPA 普遍存在于环境中。
