Bisphenol S Impaired In Vitro Ovine Early Developmental Oocyte Competence

Abstract

Introduction: Bisphenol A (BPA) is a widespread compound in the plastic industry that is especially used to produce baby bottles, food packaging and metal cans. BPA, an endocrine disruptor, leads to alterations in reproductive function and therefore has been banned from the food industry. Unregulated BPA analogues, particularly Bisphenol S (BPS), have emerged and are now used in the plastic industry. Thus, this study aimed to examine the acute effects of low and environmental doses of BPS on ewe oocyte quality and developmental competence, and its mechanism of action, during in vitro maturation. Methods: Ewe cumulus-oocyte complexes underwent in vitro maturation in the presence or absence of BPS (1 nM, 10 nM, 100 nM, 1 µM or 10 µM). Oocytes were then subjected to in vitro fertilisation and development. Results: 1 µM BPS induced a 12.7% decrease in the cleavage rate (p = 0.004) and a 42.6% decrease in the blastocyst rate (p = 0.017) compared to control. The blastocyst rate reduction was also observed with 10 nM BPS. Furthermore, 10 µM BPS reduced the oocyte maturation rate, and 1 µM BPS decreased cumulus cell progesterone secretion. PR and AMH gene expression were reduced in cumulus cells. BPS induced a 5-fold increase in MAPK 3/1 activation (p = 0.04). Conclusions: BPS impaired ewe oocyte developmental competence. The data suggest that BPS might not be a safe BPA analogue. Further studies are required to elucidate its detailed mechanism of action.

Bisphenol S Impaired Human Granulosa Cell Steroidogenesis in Vitro

“…Indeed, a sample can be contaminated by BPS but not BPSG. Previous data on ewe oocyte quality reported a detrimental effect of BPS at a concentration as low as 10 nM [45], which corresponds to the level of BPSG reported in female follicular fluids in the present study. Therefore, these data raise the issue of human oocyte sensitivity to BPS treatment, which may be similar to the sensitivity observed in the ovine model.…”

“…Moreover, as mentioned above, the BPS effects appeared to differ depending on the species. Indeed, HGC appear to be more sensitive to BPS treatment compared to other animal models, including swine [45] and cow GC [42]. On the contrary, HGC are similar in terms of sensitivity to progesterone secretion with ewe GC.…”

“…This effect is consistent with previous data from animal models. Indeed, BPS exposure (5 mg/kg body weight) decreases plasma progesterone in rats [43] and progesterone secretion in ewe GC and cumulus cells [44,45]. However, discrepancies among species or tested doses can occur.…”

Endocrine Disrupting Chemicals: Current Understanding, New Testing Strategies and Future Research Needs

“…Some studies indicate that Bisphenol A (BPA) analogues such as Bisphenol S (BPS) which are currently unregulated, and used in the plastic industry, are not safe alternatives for BPA. In ovines, BPS exposure impairs oocyte development competence with blastocyte rate reduction being observed [ 5 ]. In human granulosa cells, the administration of BPS leads to reduced secretion of oestradiol and progesterone which are observed after 48 h of exposure suggesting that the effects of chronic exposure might be similar [ 6 ].…”

Plastics derived endocrine‐disrupting compounds and their effects on early development

“…Studies have shown that BPS exposure significantly reduced testosterone secretion in mouse fetal testes (Eladak et al, 2015). BPS exposure of female mice caused a significant reduction in egg number and impaired oocyte quality and developmental competence (Desmarchais et al, 2020). BPS exposure induced oxidative stress and adipocyte differentiation leading to obesity (Ahmed & Atlas, 2016; Boucher, Ahmed, & Atlas, 2016).…”