Zinc Homeostasis, Reactive Oxygen Species Imbalance and Bisphenol-A Exposure in the Preimplantation Mouse Embryo: a possible adverse outcome pathway

• Published in: Advances in redox research : an official journal of the Society for Redox Biology and Medicine and the Society for Free Radical Research-Europe 2022-04, Vol.4, p.100032, Article 100032
• Main Authors: Chatzicharalampous, Charalampos, Bai, David, Camp, Olivia G, Joshi, Narendra, Abu-Soud, Husam M.
• Format: Article
• Language: English
• Subjects: Bisphenol-A; plastic products; reactive oxygen species; zinc deficiency
• ISSN: 2667-1379; 2667-1379
• DOI: 10.1016/j.arres.2022.100032

•BPA found in plastic products can impair embryo implantation•BPA toxicity enhances inflammation and reactive oxygen species overproduction•Reactive oxygen species mediate zinc depletion and apoptosis of embryos•AZGP1 gene in mouse oocytes is downregulated after BPA exposure•Soft plastics, potent detergents, and other products with BPA should be avoided Bisphenol-A (BPA) is a ubiquitous xenoestrogen found in plastic products used for food containers, paper products, water pipes, etc. Individuals exposed to BPA are susceptible to detrimental effects; with poor oocyte quality, sperm motility, and impaired embryo implantation observed in mouse models at levels as low as 100 µg/kg/day. To investigate the mechanism through which BPA affects embryo development, oocytes were retrieved from 8-10-week-old mice and fertilized using IVF. The embryos were divided into 4 groups and exposed to increasing BPA concentrations (10 - 200 µM) for 18 hours, then were graded daily based on morphological appearance and development. A subgroup of the treated embryos (n = 10/group) were further evaluated for induction of apoptosis, overproduction of ROS, and zinc depletion. Mouse oocytes were treated with BPA (up to 300 µΜ), then, using RT-PCR, we preformed gene expression studies for AZGP1, an important gene in zinc homeostasis. Cultured day 5 mouse embryos that were exposed to BPA concentrations > 50 µM had fewer progressions to blastocysts, lower blastocyst grades, and more were arrested as compared to controls (p