In vitro Bisphenol S affects in vitro early developmental oocyte competence in ewe

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Bisphenol S Impairs In Vitro Ovine Early Developmental Oocyte Competence

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Le Bisphenol S altère la compétence ovocytaire in vitro chez la brebis

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Bisphenol S affects In Vitro Ovine Early Developmental Oocyte Competence

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Effects of docosahexaenoic acid on bovine granulosa cell proliferation and steroidogenesis

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Bisphenol S affects in vitro early developmental oocyte competence in ewes

International audienceIn the plastics industry, bisphenol S (BPS) replaces sisphenol A reported to be an oestrogen mimetic endocrine disruptor damaging oocyte meiosis and maturation (Machtinger 2014 Reprod. Biomed. Online 29, 404). Studies on fish and rodents reported that BPS affects reproduction similarly to BPA (Uzumcu 2007 Reprod. Toxicol. 23, 337; Giulivo 2016 Environ. Res. 151, 251; Ullah 2016 Chemosphere 152, 353). Bisphenol S is detected in human urine at nanomolar concentrations (Liao 2012 Environ. Sci. Technol 46, 6860) and in some laboratory supplies (tips and tubes; unpublished data). Therefore, in this study, we assessed effects of BPS at low doses during in vitro maturation (IVM) on oocyte developmental competence in ewes. Cumulus-oocyte complexes (COC) collected from ovine follicles >2 mm underwent 24-h IVM, in the absence or presence of BPS at 1, 10, and 100 nM and 1 and 10 µM (Sigma Chemical Co.). Nuclear oocyte maturation rate was evaluated by MII oocyte count after chromatin Hoechst staining [n = 3 replicates (R), 1159 oocytes]. At 6 h of IVM, BPS effects on mRNA expression of oestrogen (E2) and progesterone (P4) receptors in cumulus cells (CC) were assessed by real-time quantitative PCR. After 24 h of IVM, The effect of BPS on P4 level was assessed in spent medium by enzyme-linked immunosorbent assay (n = 6 R, 40 COC/condition). Transcript expression level and P4 concentration were analysed using nonparametric one-way ANOVA, with Tukey post hoc test (Rcmdr, R version 3.5.3). After 24 h of IVM, matured COC underwent IVF and in vitro culture (IVC) for 7 days. Cleavage and blastocyst rates were assessed on Days 2 and 7, respectively, after IVF (8 experiments, 300 COC/condition). Data were analysed using logistic regression and linear model (R version 3.5.3). Our results showed a decreased oocyte maturation rate with 10 µM BPS (76.6%, n = 171; P = 0.0008) compared with control (88%, n = 152), with no effect on cell viability. The concentration of P4 decreased with 1 µM BPS (0.02 ng mL−1 per COC) compared with control (0.034 ng mL−1 per COC; P < 0.001). At 6 h IVM, BPS had no significant effect on oestrogen receptors (ESR1, ESR2, GPER) transcripts in CC but 10 nM BPS decreased mRNA expression of P4 receptor (PR) (0.00647 ± 0.00145; P = 0,005) compared with control (0.01165 ± 0.00196). Within fertilized COC, 1 µM BPS decreased cleavage rate (47.6%, n = 152) compared with control (54.6%; P = 0.004). Among cleaved embryos, blastocyst rate decreased to 14.2% and 12.5% with 10 nM and 1 µM BPS respectively (n = 26, P = 0.046; and n = 19, P = 0.017), compared with control (21.8%, n = 44). Bisphenol S at a low dose during ovine IVM reduced COC P4 secretion, PR transcript in CC, and cleavage and blastocyst rates. Our data suggest that BPS at an environmental dose (10 nM) negatively affects early developmental oocyte competence. Studies are ongoing to investigate the effect of BPS on Day 6 embryo cell number and on the ERK1/2 signalling pathway in oocyte

Bisphenol S versus Bisphénol A et la fonction de reproduction femelle : effets sur les cellules de granulosa ovines primaires in vitro

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Effects of bisphenol S on ovine primary granulosa cells in vitro

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Docosahexaenoic acid (DHA) effects on proliferation and steroidogenesis of bovine granulosa cells

International audienceBackground Docosahexaenoic acid (DHA) is a n-3 polyunsaturated fatty acid (PUFA) belonging to a family of biologically active fatty acids (FA), which are known to have numerous health benefits. N-3 PUFAs affect reproduction in cattle, and notably directly affect follicular cells. In terms of reproduction in cattle, n-3 PUFA-enriched diets lead to increased follicle size or numbers. Methods The objective of the present study was to analyze the effects of DHA (1, 10, 20 and 50 μM) on proliferation and steroidogenesis (parametric and/or non parametric (permutational) ANOVA) of bovine granulosa cells in vitro and mechanisms of action through protein expression (Kruskal-Wallis) and signaling pathways (non parametric ANOVA) and to investigate whether DHA could exert part of its action through the free fatty acid receptor 4 (FFAR4). Results DHA (10 and 50 μM) increased granulosa cell proliferation and DHA 10 μM led to a corresponding increase in proliferating cell nuclear antigen (PCNA) expression level. DHA also increased progesterone secretion at 1, 20 and 50 μM, and estradiol secretion at 1, 10 and 20 μM. Consistent increases in protein levels were also reported for the steroidogenic enzymes, cytochrome P450 family 11 subfamily A member 1 (CYP11A1) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (HSD3B1), and of the cholesterol transporter steroidogenic acute regulatory protein (StAR), which are necessary for production of progesterone or androstenedione. FFAR4 was expressed in all cellular types of bovine ovarian follicles, and in granulosa cells it was localized close to the cellular membrane. TUG-891 treatment (1 and 50 μM), a FFAR4 agonist, increased granulosa cell proliferation and MAPK14 phosphorylation in a similar way to that observed with DHA treatment. However, TUG-891 treatment (1, 10 and 50 μM) showed no effect on progesterone or estradiol secretion. Conclusions These data show that DHA stimulated proliferation and steroidogenesis of bovine granulosa cells and led to MAPK14 phosphorylation. FFAR4 involvement in DHA effects requires further investigation, even if our data might suggest FFAR4 role in DHA effects on granulosa cell proliferation. Other mechanisms of DHA action should be investigated as the steroidogenic effects seemed to be independent of FFAR4 activation

Effects of docosahexaenoic acid on bovine granulosa cells in vitro: involvement of FFAR4 receptor

Effects of docosahexaenoic acid on bovine granulosa cells in vitro: involvement of FFAR4 receptor. 2. Journées du GdR 3606 Repr