A new chapter in the bisphenol A story: bisphenol S and bisphenol F are not safe alternatives to this compound

Bisphenol A (BPA) is a widely studied typical endocrine-disrupting chemical, and one of the major new issues is the safe replacement of this commonly used compound. Bisphenol S (BPS) and bisphenol F (BPF) are already or are planned to be used as BPA alternatives. With the use of a culture system that we developed (fetal testis assay [FeTA]), we previously showed that 10 nmol/L BPA reduces basal testosterone secretion of human fetal testis explants and that the susceptibility to BPA is at least 100-fold lower in rat and mouse fetal testes. Here, we show that addition of LH in the FeTA system considerably enhances BPA minimum effective concentration in mouse and human but not in rat fetal testes. Then, using the FeTA system without LH (the experimental conditions in which mouse and human fetal testes are most sensitive to BPA), we found that, as for BPA, 10 nmol/L BPS or BPF is sufficient to decrease basal testosterone secretion by human fetal testes with often nonmonotonic dose-response curves. In fetal mouse testes, the dose-response curves were mostly monotonic and the minimum effective concentrations were 1,000 nmol/L for BPA and BPF and 100 nmol/L for BPS. Finally, 10,000 nmol/L BPA, BPS, or BPF reduced Insl3 expression in cultured mouse fetal testes. This is the first report describing BPS and BPF adverse effects on a physiologic function in humans and rodents

Effects of environmental Bisphenol A exposures on germ cell development and Leydig cell function in the human fetal testis

<div><p>Background</p><p>Using an organotypic culture system termed human Fetal Testis Assay (hFeTA) we previously showed that 0.01 μM BPA decreases basal, but not LH-stimulated, testosterone secreted by the first trimester human fetal testis. The present study was conducted to determine the potential for a long-term antiandrogenic effect of BPA using a xenograft model, and also to study the effect of BPA on germ cell development using both the hFETA and xenograft models.</p><p>Methods</p><p>Using the hFeTA system, first trimester testes were cultured for 3 days with 0.01 to 10 μM BPA. For xenografts, adult castrate male nude mice were injected with hCG and grafted with first trimester testes. Host mice received 10 μM BPA (~ 500 μg/kg/day) in their drinking water for 5 weeks. Plasma levels of total and unconjugated BPA were 0.10 μM and 0.038 μM respectively. Mice grafted with second trimester testes received 0.5 and 50 μg/kg/day BPA by oral gavage for 5 weeks.</p><p>Results</p><p>With first trimester human testes, using the hFeTA model, 10 μM BPA increased germ cell apoptosis. In xenografts, germ cell density was also reduced by BPA exposure. Importantly, BPA exposure significantly decreased the percentage of germ cells expressing the pluripotency marker AP-2γ, whilst the percentage of those expressing the pre-spermatogonial marker MAGE-A4 significantly increased. BPA exposure did not affect hCG-stimulated androgen production in first and second trimester xenografts as evaluated by both plasma testosterone level and seminal vesicle weight in host mice.</p><p>Conclusions</p><p>Exposure to BPA at environmentally relevant concentrations impairs germ cell development in first trimester human fetal testis, whilst gonadotrophin-stimulated testosterone production was unaffected in both first and second trimester testis. Studies using first trimester human fetal testis demonstrate the complementarity of the FeTA and xenograft models for determining the respective short-term and long term effects of environmental exposures.</p></div

[Contraception, therapeutic abortion, and pulmonary arterial hypertension].

International audienceDespite therapeutic advances, maternal mortality is high in pulmonary arterial hypertension (PAH). PAH treatment may interfere with the proposed method of contraception. Moreover, some treatments (endothelin receptor antagonists, anti-vitamin K) are teratogenic. If pregnancy is strictly not recommended in PAH, few specific contraceptive guidelines are available. The contraceptive method must be discussed on a case by case basis with the patient, the reference team for PAH, and the gynecology department.The advantages of the intrauterine device (IUD) with progesterone (reliability, simplicity, compliance, few contraindications and interactions, possibility of use in the nulliparous patient, reimbursement by the healthcare system) make it a good contraceptive choice in these circumstances. Therapeutic abortion is a situation of contraceptive failure, it must always be performed in hospitals. It must lead to effective contraceptive advice

Differential effects of bisphenol A and diethylstilbestrol on human, rat and mouse fetal leydig cell function.

Endocrine disruptors (ED) have been incriminated in the current increase of male reproductive alterations. Bisphenol A (BPA) is a widely used weak estrogenic environmental ED and it is debated whether BPA concentrations within the average internal exposure are toxic. In the present study we investigated the effects of 10(-12) to 10(-5) M BPA concentrations on fetal Leydig cell function, as fetal life is a critical period of sensitivity to ED effects on male reproductive function. To this aim, fetal testes from human at 6.5-10.5 gestational weeks (GW) or from rat and mouse at a comparable critical period of development (14.5 days post-coitum (dpc) for rat and 12.5 dpc for mouse) were explanted and cultured using our validated organotypic culture system in the presence or absence of BPA for 1-3 days. BPA concentrations as low as 10(-8) M reduced testosterone secretion by human testes from day 1 of culture onwards, but not by mouse and rat testes where concentrations equal to 10(-5) M BPA were required. Similarly, 10(-8) M BPA reduced INSL3 mRNA levels only in human cultured testes. On the contrary, 10(-5) and 10(-6) M diethylstilbestrol (DES), a classical estrogenic compound, affected testosterone secretion only in rat and mouse testis cultures, but not in human testis cultures. Lastly, contrarily to the DES effect, the negative effect of BPA on testosterone produced by the mouse fetal testis was maintained after invalidation of estrogen receptor α (ERα). In conclusion, these results evidenced i) a deleterious effect of BPA on fetal Leydig cells function in human for concentrations from 10(-8) M upwards, ii) species-specific differences raising concerns about extrapolation of data from rodent studies to human risk assessment, iii) a specific signaling pathway for BPA which differs from the DES one and which does not involve ERα

Differential Effects of Bisphenol A and Diethylstilbestrol on Human, Rat and Mouse Fetal Leydig Cell Function

International audienceEndocrine disruptors (ED) have been incriminated in the current increase of male reproductive alterations. Bisphenol A (BPA) is a widely used weak estrogenic environmental ED and it is debated whether BPA concentrations within the average internal exposure are toxic. In the present study we investigated the effects of 10(-12) to 10(-5) M BPA concentrations on fetal Leydig cell function, as fetal life is a critical period of sensitivity to ED effects on male reproductive function. To this aim, fetal testes from human at 6.5-10.5 gestational weeks (GW) or from rat and mouse at a comparable critical period of development (14.5 days post-coitum (dpc) for rat and 12.5 dpc for mouse) were explanted and cultured using our validated organotypic culture system in the presence or absence of BPA for 1-3 days. BPA concentrations as low as 10(-8) M reduced testosterone secretion by human testes from day 1 of culture onwards, but not by mouse and rat testes where concentrations equal to 10(-5) M BPA were required. Similarly, 10(-8) M BPA reduced INSL3 mRNA levels only in human cultured testes. On the contrary, 10(-5) and 10(-6) M diethylstilbestrol (DES), a classical estrogenic compound, affected testosterone secretion only in rat and mouse testis cultures, but not in human testis cultures. Lastly, contrarily to the DES effect, the negative effect of BPA on testosterone produced by the mouse fetal testis was maintained after invalidation of estrogen receptor alpha (ER alpha). In conclusion, these results evidenced i) a deleterious effect of BPA on fetal Leydig cells function in human for concentrations from 10(-8) M upwards, ii) species-specific differences raising concerns about extrapolation of data from rodent studies to human risk assessment, iii) a specific signaling pathway for BPA which differs from the DES one and which does not involve ER alpha

Differential Effects of Bisphenol A and Diethylstilbestrol on Human, Rat and Mouse Fetal Leydig Cell Function

International audienceEndocrine disruptors (ED) have been incriminated in the current increase of male reproductive alterations. Bisphenol A (BPA) is a widely used weak estrogenic environmental ED and it is debated whether BPA concentrations within the average internal exposure are toxic. In the present study we investigated the effects of 10(-12) to 10(-5) M BPA concentrations on fetal Leydig cell function, as fetal life is a critical period of sensitivity to ED effects on male reproductive function. To this aim, fetal testes from human at 6.5-10.5 gestational weeks (GW) or from rat and mouse at a comparable critical period of development (14.5 days post-coitum (dpc) for rat and 12.5 dpc for mouse) were explanted and cultured using our validated organotypic culture system in the presence or absence of BPA for 1-3 days. BPA concentrations as low as 10(-8) M reduced testosterone secretion by human testes from day 1 of culture onwards, but not by mouse and rat testes where concentrations equal to 10(-5) M BPA were required. Similarly, 10(-8) M BPA reduced INSL3 mRNA levels only in human cultured testes. On the contrary, 10(-5) and 10(-6) M diethylstilbestrol (DES), a classical estrogenic compound, affected testosterone secretion only in rat and mouse testis cultures, but not in human testis cultures. Lastly, contrarily to the DES effect, the negative effect of BPA on testosterone produced by the mouse fetal testis was maintained after invalidation of estrogen receptor alpha (ER alpha). In conclusion, these results evidenced i) a deleterious effect of BPA on fetal Leydig cells function in human for concentrations from 10(-8) M upwards, ii) species-specific differences raising concerns about extrapolation of data from rodent studies to human risk assessment, iii) a specific signaling pathway for BPA which differs from the DES one and which does not involve ER alpha

Effect of ERα gene inactivation on <i>in vitro</i> testicular response to BPA.

<p>Testes from homozygous 12.5 dpc (ERα−/−), heterozygous (ERα+/−) and wild-type (ERα+/+) ERα-deficient fetuses were cultured on floating filters for 48 h. One testis from each animal was cultured in control medium and the other one in medium containing 10⁻⁵ M BPA. Values are means ± SEM of testosterone secreted in the medium during the 2 days of culture by BPA-treated testes referred to testosterone secreted by the respective contralateral control testes; n = 6 (ERα+/+), 13 (ERα+/−) and 5 (ERα−/−), * p<0.05 in the statistical comparison between BPA-treated and control testes using the Wilcoxon’s parametric paired t test.</p

Effect of BPA treatment on testicular histology.

<p>Histological sections of human, rat and mouse fetal testes removed at 11 gestational week (GW), 14.5 day post conception (dpc) and 12.5 dpc respectively after one day of culture in control medium (D0) followed by 3 days of culture in the absence (control) or presence (BPA) of 10⁻⁵ M BPA. At the end of the culture, testes were fixed in Bouin’s fluid and hematoxylin/eosin staining of the histological sections was performed. The testicular architecture and morphology were not affected by BPA-treatment. Black arrows: Sertoli cells; white arrows: Leydig cells; arrowhead: gonocytes.</p

Effect of BPA on testosterone secretion by human fetal testes as a function of their developmental stage.

<p>Individual (normalized to D0 and expressed as the percentage of the control explants) values at D2 of culture for the samples of the experiment described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051579#pone-0051579-g002" target="_blank">Figure 2</a> are presented. GW: gestational week.</p

Effect of BPA on testosterone secretion by rat and mouse fetal testes.

<p>Testes were removed from 14.5 dpc rat and 12.5 dpc mouse fetuses and cultured for one day in control medium (D0). Then, for each fetus, one testis was kept in control medium and the other one in medium supplemented with various concentrations of BPA as indicated for 3 days (D1 to D3). Values were calculated and expressed as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051579#pone-0051579-g001" target="_blank">Figure 1</a>; Rat: n = 9 for 10⁻¹² M, n = 12 for 10⁻⁸ M, n = 9 for 10⁻⁷ M, and n = 7 for 10⁻⁵ M. Mouse: n = 9 for 10⁻¹² M, n = 15 for 10⁻⁸ M, n = 17 for 10⁻⁷ M and n = 10 for 10⁻⁵ M. *p<0.05, ** p<0.01, *** p<0.001 in the statistical comparison between BPA-treated and control testes using the Wilcoxon’s non-parametric paired test.</p