Bisphenol A and S impaired ovine granulosa cell steroidogenesis

Bisphenols, plasticisers used in food containers, can transfer to food. Bisphenol A (BPA) has been described as an endocrine disruptor and consequently banned from the food industry in several countries. It was replaced by a structural analogue, Bisphenol S (BPS). BPA action on the steroidogenesis is one of the mechanisms underlying its adverse effects on the efficiency of female reproduction. This study aimed to determine whether BPS is a safe alternative to BPA regarding GC functions. Antral follicles (2–6 mm), of approximatively 1000 adult ewe ovaries, were aspired and GC purified. For 48 h, ovine GC were treated with BPA or BPS (from 1 nM to 200 µM) and the effects on cell viability, proliferation, steroid production, steroidogenic enzyme expression and signalling pathways were investigated. Dosages at and greater than 100 μM BPA and 10 µM BPS decreased progesterone secretion by 39% (P < 0.001) and 22% (P = 0.040), respectively. BPA and BPS 10 μM and previously mentioned concentrations increased oestradiol secretion two-fold (P < 0.001 and P = 0.082, respectively). Only 100 µM BPA induced a decrease (P < 0.001) in gene expression of the enzymes of steroidogenesis involved in the production of progesterone. BPA reduced MAPK3/1 phosphorylation and ESR1 and ESR2 gene expression, effects that were not observed with BPS. BPA and BPS altered steroidogenesis of ovine GC. Thus, BPS does not appear to be a safe alternative for BPA. Further investigations are required to elucidate BPA and BPS mechanisms of action.

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Bisphenol A, Bisphenol F, and Bisphenol S: The Bad and the Ugly. Where Is the Good?

Life ◽

10.3390/life11040314 ◽

2021 ◽

Vol 11 (4) ◽

pp. 314

Author(s):

Sophie Fouyet ◽

Elodie Olivier ◽

Pascale Leproux ◽

Mélody Dutot ◽

Patrice Rat

Keyword(s):

Bisphenol A ◽

P2x7 Receptor ◽

Chromatin Condensation ◽

Receptor Activation ◽

Bisphenol S ◽

Safe Alternative ◽

Bisphenol F ◽

Placental Cells ◽

Human Placental Cells

Background: Bisphenol A (BPA), a reprotoxic and endocrine-disrupting chemical, has been substituted by alternative bisphenols such as bisphenol F (BPF) and bisphenol S (BPS) in the plastic industry. Despite their detection in placenta and amniotic fluids, the effects of bisphenols on human placental cells have not been characterized. Our objective was to explore in vitro and to compare the toxicity of BPA to its substitutes BPF and BPS to highlight their potential risks for placenta and then pregnancy. Methods: Human placenta cells (JEG-Tox cells) were incubated with BPA, BPF, and BPS for 72 h. Cell viability, cell death, and degenerative P2X7 receptor and caspases activation, and chromatin condensation were assessed using microplate cytometry and fluorescence microscopy. Results: Incubation with BPA, BPF, or BPS was associated with P2X7 receptor activation and chromatin condensation. BPA and BPF induced more caspase-1, caspase-9, and caspase-3 activation than BPS. Only BPF enhanced caspase-8 activity. Conclusions: BPA, BPF, and BPS are all toxic to human placental cells, with the P2X7 receptor being a common key element. BPA substitution by BPF and BPS does not appear to be a safe alternative for human health, particularly for pregnant women and their fetuses.

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182 Bisphenol A, but not bisphenol S, affects key microRNAs during bovine oocyte maturation

Reproduction Fertility and Development ◽

10.1071/rdv32n2ab182 ◽

2020 ◽

Vol 32 (2) ◽

pp. 219

Author(s):

R. Sabry ◽

M. Nguyen ◽

L. Stalker ◽

J. LaMarre ◽

L. Favetta

Keyword(s):

Bisphenol A ◽

Oocyte Maturation ◽

Messenger Rna ◽

Cumulus Cells ◽

Mature Mirnas ◽

Protein Quantification ◽

Female Reproduction ◽

Bisphenol S ◽

Total Rna ◽

Protein Levels

Oocyte maturation involves crucial hormone-dependent events that are uniquely susceptible to toxic insults by endocrine disrupting chemicals (EDCs). Emerging evidence suggests that small RNAs, including microRNAs (miRNAs), may be key participants in the response to EDCs. Bisphenol A (BPA) and bisphenol S (BPS) are chemicals with detrimental health effects, with BPA negatively affecting oocyte quality. The mode of action of bisphenols at the epigenetic level is not clear. Several miRNAs have been identified as crucial regulators of gene expression during development. This study aimed to examine key miRNAs in response to BPA or BPS treatment during oocyte maturation. Primary forms (pri-miRNA) and mature forms of miR-21, miR-155, miR-34c, and miR-146a were quantified by quantitative (q)PCR in IVM bovine cumulus-oocyte complexes (COCs) and invitro cultured (IVC) cumulus cells treated with BPA and BPS at physiologically significant doses (0.05mgmL−1). Total RNA, containing both forms of microRNAs, was isolated from pools of 40 COCs on a minimum of three biological replicates. Primary miRNAs and mature miRNAs were reverse transcribed (RT) using qScript cDNA and microRNA/cDNA kits, respectively, and quantified by qPCR, with three technical replicates for each biological one. In addition, mRNA and protein quantification of the downstream target DNMT3A in IVC cumulus cells further enhanced our understanding of EDC interference in epigenetic regulations in female reproduction. Total RNA was isolated from cumulus cells, mRNA (1μg) and mature miRNAs (0.5μg) were RT separately and cDNA was quantified by qPCR, as described above. Expression values were normalized against two housekeeping genes selected by GeNorm analysis. Twenty micrograms of proteins extracted by sonication were loaded on a 8% acrylamide gel and analysed by western blotting. Densitometry analysis was performed on 3 separate blots with protein levels normalized to the loading control, β-actin. One-way ANOVA was used to determine statistical differences among treatment groups with P<0.05 considered statistically significant. Results showed that BPA significantly increased miR-21 in COCs (P=0.02) and cumulus cells (P=0.01), increased pri-miR-21 in oocytes (P=0.03), suppressed miR-34c in cumulus cells (P=0.02), increased miR-155 in denuded oocytes (P=0.04), and had no effect on miR-146a. No changes were observed in response to BPS. Experiments in IVC cumulus cells showed similar miRNA profiles: miR-21 and miR-155 were significantly overexpressed in BPA-treated cells (P=0.04); however, miR-34c and miR-146a were not affected. Messenger RNA levels of DNMT3A increased (P=0.02) and protein levels of DNMT3A decreased in response to BPA (P=0.005). Overall, this study presents novel findings of BPA-induced miRNA dysregulation in IVM bovine oocytes and in IVC bovine cumulus cells. We can speculate that miR-21 participates in the BPA-induced dysregulation of DNMT3A, contributing to decreased fertility. This study did not show any effect of BPS on microRNA expression, suggesting an alternative mechanistic pathway for this analogue.

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