Limits...
An investigation of the endocrine-disruptive effects of bisphenol a in human and rat fetal testes.

Ben Maamar M, Lesné L, Desdoits-Lethimonier C, Coiffec I, Lassurguère J, Lavoué V, Deceuninck Y, Antignac JP, Le Bizec B, Perdu E, Zalko D, Pineau C, Chevrier C, Dejucq-Rainsford N, Mazaud-Guittot S, Jégou B - PLoS ONE (2015)

Bottom Line: BPA concentrations of 10(-8)M and 10(-5)M for 72 h reduced testosterone production by the Sprague-Dawley fetal rat testes, while only 10-5M suppressed it in the Wistar strain.The suppressive effects at 10-5M were seen as early as 24h and 48 h in both strains.We concluded that (i) BPA can display anti-androgenic effects both in rat and human fetal testes; (ii) it is essential to ascertain that the divergent effects of endocrine disruptors between species in vitro do not result from the culture conditions used, and/or the rodent strain selected; (iii) the optimization of each in vitro assay for a given species should be a major objective rather than the search of an hypothetical trans-species consensual model-system, as the organization of the testis is intrinsically different between mammalian species; (iv) due to the uncertainty existing on the internal exposure of the human fetal testis to BPA, and the insufficient number of epidemiological studies on the endocrine disruptive effects of BPA, caution should be taken in the extrapolation of our present results to the human reproductive health after fetal exposure to BPA.

View Article: PubMed Central - PubMed

Affiliation: Inserm (Institut national de la santé et de la recherche médicale), IRSET, U1085, SFR Biosit, Campus de Beaulieu, Rennes, CEDEX, France; Université de Rennes I, Campus de Beaulieu, Rennes, CEDEX, France.

ABSTRACT
Few studies have been undertaken to assess the possible effects of bisphenol A (BPA) on the reproductive hormone balance in animals or humans with often contradictory results. We investigated possible direct endocrine disruption by BPA of the fetal testes of 2 rat strains (14.5-17.5 days post-coitum) and humans (8-12 gestational weeks) and under different culture conditions. BPA concentrations of 10(-8)M and 10(-5)M for 72 h reduced testosterone production by the Sprague-Dawley fetal rat testes, while only 10-5M suppressed it in the Wistar strain. The suppressive effects at 10-5M were seen as early as 24h and 48 h in both strains. BPA at 10(-7)-10(-5)M for 72 h suppressed the levels of fetal rat Leydig cell insulin-like factor 3 (INSL3). BPA exposure at 10(-8)M, 10(-7)M, and 10(-5)M for 72 h inhibited testosterone production in fetal human testes. For the lowest doses, the effects observed occurred only when no gonadotrophin was added to the culture media and were associated with a poorly preserved testicular morphology. We concluded that (i) BPA can display anti-androgenic effects both in rat and human fetal testes; (ii) it is essential to ascertain that the divergent effects of endocrine disruptors between species in vitro do not result from the culture conditions used, and/or the rodent strain selected; (iii) the optimization of each in vitro assay for a given species should be a major objective rather than the search of an hypothetical trans-species consensual model-system, as the organization of the testis is intrinsically different between mammalian species; (iv) due to the uncertainty existing on the internal exposure of the human fetal testis to BPA, and the insufficient number of epidemiological studies on the endocrine disruptive effects of BPA, caution should be taken in the extrapolation of our present results to the human reproductive health after fetal exposure to BPA.

Show MeSH

Related in: MedlinePlus

BPA effects at 10-5M on the testicular histology and testicular cells.A) A treatment with 10-5M of BPA did not affect the morphology and the testis organization of the fetal rat. B) Effect of 10-5M of BPA on the total number of gonocytes, Sertoli cells and Leydig cells. Values are mean ± SEM of 4–7 fetuses. Responses to BPA were measured by comparing one control testis (DMSO-treated) with the contralateral testis cultured in medium containing the tested factor. C) Quantitative analysis of BrdU incorporation into gonocytes and Sertoli cells after 72 h of culture measured as the percentage of BrdU-positive gonocytes or Sertoli cells in at least 1000 cells (n = 4 fetuses). D) Apoptosis was detected using a cleaved-caspase 3 staining, caspase-3 being cleaved in the cells undergoing apoptosis. Caspase 3-positive cells were counted on the whole testis with regard to their tubular or interstitial localization (n = 5 fetuses). *p < 0.05 by Wilcoxon signed rank tests on paired data.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4338204&req=5

pone.0117226.g002: BPA effects at 10-5M on the testicular histology and testicular cells.A) A treatment with 10-5M of BPA did not affect the morphology and the testis organization of the fetal rat. B) Effect of 10-5M of BPA on the total number of gonocytes, Sertoli cells and Leydig cells. Values are mean ± SEM of 4–7 fetuses. Responses to BPA were measured by comparing one control testis (DMSO-treated) with the contralateral testis cultured in medium containing the tested factor. C) Quantitative analysis of BrdU incorporation into gonocytes and Sertoli cells after 72 h of culture measured as the percentage of BrdU-positive gonocytes or Sertoli cells in at least 1000 cells (n = 4 fetuses). D) Apoptosis was detected using a cleaved-caspase 3 staining, caspase-3 being cleaved in the cells undergoing apoptosis. Caspase 3-positive cells were counted on the whole testis with regard to their tubular or interstitial localization (n = 5 fetuses). *p < 0.05 by Wilcoxon signed rank tests on paired data.

Mentions: After fetal testes from Sprague-Dawley rats were cultured for 72 h with BPA in DMSO, INSL3 production by fetal Leydig cells was lower than in control cultures from the dose of 10-8M (-42%); this inhibition was significant from 10-7M (-55%, p = 0.05) onwards: 10-6M: -67%, p<0.05; 10-5M: -76%, p<0.01 (Fig. 1B). None of the BPA treatments at any time point had any apparent effect on the gross morphology of the rat fetal testis (Fig. 2A). After Sprague-Dawley fetal testes were cultured for 72 h with 10-5M BPA diluted in DMSO, the number of gonocytes decreased (Fig. 2B: -23%, p<0.05). The number of BrdU-labeled gonocytes was not affected by this BPA concentration (Fig. 2C). Under the same culture conditions, neither the number of Sertoli cells (Fig. 2B) nor the number of BrdU-labeled Sertoli cells was significantly affected by the treatment (Fig. 2C). In the presence of 10-5M BPA, the number of Leydig cells was not affected (Fig. 2B). Both intratubular and interstitial compartments were checked for apoptosis, and neither was significantly affected by the BPA treatment at 10-5M, the highest concentration to which the rat fetal testes were exposed (Fig. 2D).


An investigation of the endocrine-disruptive effects of bisphenol a in human and rat fetal testes.

Ben Maamar M, Lesné L, Desdoits-Lethimonier C, Coiffec I, Lassurguère J, Lavoué V, Deceuninck Y, Antignac JP, Le Bizec B, Perdu E, Zalko D, Pineau C, Chevrier C, Dejucq-Rainsford N, Mazaud-Guittot S, Jégou B - PLoS ONE (2015)

BPA effects at 10-5M on the testicular histology and testicular cells.A) A treatment with 10-5M of BPA did not affect the morphology and the testis organization of the fetal rat. B) Effect of 10-5M of BPA on the total number of gonocytes, Sertoli cells and Leydig cells. Values are mean ± SEM of 4–7 fetuses. Responses to BPA were measured by comparing one control testis (DMSO-treated) with the contralateral testis cultured in medium containing the tested factor. C) Quantitative analysis of BrdU incorporation into gonocytes and Sertoli cells after 72 h of culture measured as the percentage of BrdU-positive gonocytes or Sertoli cells in at least 1000 cells (n = 4 fetuses). D) Apoptosis was detected using a cleaved-caspase 3 staining, caspase-3 being cleaved in the cells undergoing apoptosis. Caspase 3-positive cells were counted on the whole testis with regard to their tubular or interstitial localization (n = 5 fetuses). *p < 0.05 by Wilcoxon signed rank tests on paired data.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4338204&req=5

pone.0117226.g002: BPA effects at 10-5M on the testicular histology and testicular cells.A) A treatment with 10-5M of BPA did not affect the morphology and the testis organization of the fetal rat. B) Effect of 10-5M of BPA on the total number of gonocytes, Sertoli cells and Leydig cells. Values are mean ± SEM of 4–7 fetuses. Responses to BPA were measured by comparing one control testis (DMSO-treated) with the contralateral testis cultured in medium containing the tested factor. C) Quantitative analysis of BrdU incorporation into gonocytes and Sertoli cells after 72 h of culture measured as the percentage of BrdU-positive gonocytes or Sertoli cells in at least 1000 cells (n = 4 fetuses). D) Apoptosis was detected using a cleaved-caspase 3 staining, caspase-3 being cleaved in the cells undergoing apoptosis. Caspase 3-positive cells were counted on the whole testis with regard to their tubular or interstitial localization (n = 5 fetuses). *p < 0.05 by Wilcoxon signed rank tests on paired data.
Mentions: After fetal testes from Sprague-Dawley rats were cultured for 72 h with BPA in DMSO, INSL3 production by fetal Leydig cells was lower than in control cultures from the dose of 10-8M (-42%); this inhibition was significant from 10-7M (-55%, p = 0.05) onwards: 10-6M: -67%, p<0.05; 10-5M: -76%, p<0.01 (Fig. 1B). None of the BPA treatments at any time point had any apparent effect on the gross morphology of the rat fetal testis (Fig. 2A). After Sprague-Dawley fetal testes were cultured for 72 h with 10-5M BPA diluted in DMSO, the number of gonocytes decreased (Fig. 2B: -23%, p<0.05). The number of BrdU-labeled gonocytes was not affected by this BPA concentration (Fig. 2C). Under the same culture conditions, neither the number of Sertoli cells (Fig. 2B) nor the number of BrdU-labeled Sertoli cells was significantly affected by the treatment (Fig. 2C). In the presence of 10-5M BPA, the number of Leydig cells was not affected (Fig. 2B). Both intratubular and interstitial compartments were checked for apoptosis, and neither was significantly affected by the BPA treatment at 10-5M, the highest concentration to which the rat fetal testes were exposed (Fig. 2D).

Bottom Line: BPA concentrations of 10(-8)M and 10(-5)M for 72 h reduced testosterone production by the Sprague-Dawley fetal rat testes, while only 10-5M suppressed it in the Wistar strain.The suppressive effects at 10-5M were seen as early as 24h and 48 h in both strains.We concluded that (i) BPA can display anti-androgenic effects both in rat and human fetal testes; (ii) it is essential to ascertain that the divergent effects of endocrine disruptors between species in vitro do not result from the culture conditions used, and/or the rodent strain selected; (iii) the optimization of each in vitro assay for a given species should be a major objective rather than the search of an hypothetical trans-species consensual model-system, as the organization of the testis is intrinsically different between mammalian species; (iv) due to the uncertainty existing on the internal exposure of the human fetal testis to BPA, and the insufficient number of epidemiological studies on the endocrine disruptive effects of BPA, caution should be taken in the extrapolation of our present results to the human reproductive health after fetal exposure to BPA.

View Article: PubMed Central - PubMed

Affiliation: Inserm (Institut national de la santé et de la recherche médicale), IRSET, U1085, SFR Biosit, Campus de Beaulieu, Rennes, CEDEX, France; Université de Rennes I, Campus de Beaulieu, Rennes, CEDEX, France.

ABSTRACT
Few studies have been undertaken to assess the possible effects of bisphenol A (BPA) on the reproductive hormone balance in animals or humans with often contradictory results. We investigated possible direct endocrine disruption by BPA of the fetal testes of 2 rat strains (14.5-17.5 days post-coitum) and humans (8-12 gestational weeks) and under different culture conditions. BPA concentrations of 10(-8)M and 10(-5)M for 72 h reduced testosterone production by the Sprague-Dawley fetal rat testes, while only 10-5M suppressed it in the Wistar strain. The suppressive effects at 10-5M were seen as early as 24h and 48 h in both strains. BPA at 10(-7)-10(-5)M for 72 h suppressed the levels of fetal rat Leydig cell insulin-like factor 3 (INSL3). BPA exposure at 10(-8)M, 10(-7)M, and 10(-5)M for 72 h inhibited testosterone production in fetal human testes. For the lowest doses, the effects observed occurred only when no gonadotrophin was added to the culture media and were associated with a poorly preserved testicular morphology. We concluded that (i) BPA can display anti-androgenic effects both in rat and human fetal testes; (ii) it is essential to ascertain that the divergent effects of endocrine disruptors between species in vitro do not result from the culture conditions used, and/or the rodent strain selected; (iii) the optimization of each in vitro assay for a given species should be a major objective rather than the search of an hypothetical trans-species consensual model-system, as the organization of the testis is intrinsically different between mammalian species; (iv) due to the uncertainty existing on the internal exposure of the human fetal testis to BPA, and the insufficient number of epidemiological studies on the endocrine disruptive effects of BPA, caution should be taken in the extrapolation of our present results to the human reproductive health after fetal exposure to BPA.

Show MeSH
Related in: MedlinePlus