Bisphenol A Exposure and Sperm ACHE Hydroxymethylation in Men.

Xiuxia Song,Maohua Miao,Dekun Li,Youping Tian,Wei Yuan,Xiaoyu Zhou,Hong Liang,Runsheng Li

doi:10.3390/ijerph16010152

Abstract

Exposure to bisphenol A (BPA) has been shown to impact human sperm quality. The epigenetic mechanisms underlying the effect remain unknown. The acetylcholinesterase (ACHE) gene is a sperm-expressed gene encoding the acetylcholine hydrolyzing enzyme acetylcholinesterase and participates in the apoptosis of cells, including sperm. This study aimed to examine whether BPA exposure is associated with the hydroxymethylation level of the sperm ACHE gene. A total of 157 male factory workers were studied, among whom 74 had BPA exposure in the workplace (BPA exposure group) and 83 had no BPA exposure in the workplace (control group). Urine samples were collected for BPA measurement and semen samples were collected to assay for ACHE hydroxymethylation. Sperm ACHE hydroxymethylation level was higher in the BPA exposure group (p = 0.041) compared to the control group. When subjects were categorized according to tertiles of detected BPA level, higher ACHE hydroxymethylation levels were observed for the lowest, middle, and top tertiles compared to those with BPA below the limit of detection (LOD). In a linear regression analysis adjusted for confounders, a positive linear association between urine BPA concentration and 5-hydroxymethylcytosine (5hmC) rate of the sperm ACHE gene was observed, although the association did not reach statistical significance in all categories after being stratified by the BPA tertile. In conclusion, 5hmC of the sperm ACHE gene was positively associated with BPA exposure, which may provide supportive evidence for BPA’s effects on male fertility or other health endpoints.

Highlights

Bisphenol A (BPA) is a synthetic industrial chemical that has been widely used in the manufacturing of polycarbonate plastic and epoxy resins, such as water and baby bottles, reusable food and drink containers and some dental sealants
The mean BPA concentrations in the pre-shift and post-shift samples were used in the exposure group
We provide the first epidemiological evidence that BPA exposure is associated with increased 5hmC of the sperm ACHE gene in men

Summary

Introduction

Bisphenol A (BPA) is a synthetic industrial chemical that has been widely used in the manufacturing of polycarbonate plastic and epoxy resins, such as water and baby bottles, reusable food and drink containers and some dental sealants. BPA can enter the body through diet, the dermis, and the respiratory tract [1,2,3]. Exposure to BPA has gained wide attention over the past decades due to its ubiquitous exposure and potential endocrine disrupting effects, including weak estrogenic and strong anti-androgenic and anti-thyroid activities [4,5,6,7]. An increasing body of evidence has shown that exposure to BPA is associated with higher risks of adverse health effects in humans, including cardiovascular disease, insulin resistant diabetes, obesity, and cancers [8,9,10,11]. Public Health 2019, 16, 152; doi:10.3390/ijerph16010152 www.mdpi.com/journal/ijerph

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