41 research outputs found
Time- and Dose-Related Effects of Di-(2-ethylhexyl) Phthalate and Its Main Metabolites on the Function of the Rat Fetal Testis in Vitro
International audienceBACKGROUND: Endocrine-disrupting effects of phthalates are understood primarily from in utero exposures within the fetal rat testis. Nevertheless, their path of action, dose-response character, and cellular target(s) within the fetal testis are not known. OBJECTIVES: In this study we investigated the effects of di-(2-ethylhexyl) phthalate (DEHP), mono-(2-ethylhexyl) phthalate (MEHP), and several of their metabolites on the development of organo-cultured testes from rat fetus. METHODS: We removed testes from 14.5-day-old rat fetuses and cultured them for 1-3 days with or without DEHP, MEHP, and the metabolites. RESULTS: DEHP (10(-5) M) produced a proandrogenic effect after 3 days of culture, whereas MEHP disrupted testis morphology and function. Leydig cells were the first affected by MEHP, with a number of them being inappropriately located within some seminiferous tubules. Additionally, we found a time- and dose-dependent reduction of testosterone. By 48 hr, gonocyte proliferation had decreased, whereas apoptosis increased. Sertoli cell number was unaffected, although some cells appeared vacuolated, and production of anti-Müllerian hormone decreased in a time- and dose-dependent manner. The derived metabolite mono-(2-ethyl-5-hydroxyhexyl) phthalate was the only one to cause deleterious effects to the rat fetal testis in vitro. CONCLUSION: We hope that this in vitro method will facilitate the study of different phthalate esters and other endocrine disruptors for direct testicular effects
Many Putative Endocrine Disruptors Inhibit Prostaglandin Synthesis
International audienceBACKGROUND: Prostaglandins (PGs) play key roles in development and maintenance of homeostasis of the adult body. Despite these important roles, it remains unclear whether the PG pathway is a target for endocrine disruption. However, several known endocrine-disrupting compounds (EDCs) share a high degree of structural similarity with mild analgesics. OBJECTIVES AND METHODS: Using cell-based transfection and transduction experiments, mass spectrometry, and organotypic assays together with molecular modeling, we investigated whether inhibition of the PG pathway by known EDCs could be a novel point of endocrine disruption. RESULTS: We found that many known EDCs inhibit the PG pathway in a mouse Sertoli cell line and in human primary mast cells. The EDCs also reduced PG synthesis in ex vivo rat testis, and this reduction was correlated with a reduced testosterone production. The inhibition of PG synthesis occurred without involvement of canonical PG receptors or the peroxisome proliferator-activated receptors (PPARs), which have previously been described as targets of EDCs. Instead, our results suggest that the compounds may bind directly into the active site of the cyclooxygenase (COX) enzymes, thereby obstructing the conversion of arachidonic acid to PG precursors without interfering with the expression of the COX enzymes. A common feature of the PG inhibitory EDCs is the presence of aromatic groups that may stabilize binding in the hydrophobic active site of the COX enzymes. CONCLUSION: Our findings suggest a hitherto unknown mode of action by EDCs through inhibition of the PG pathway and suggest new avenues to investigate effects of EDCs on reproductive and immunological disorders that have become increasingly common in recent decades
Ibuprofen alters human testicular physiology to produce a state of compensated hypogonadism
correction de l'article correspondant à la notice https://prodinra.inra.fr/record/425677International audienceConcern has been raised over increased male reproductive disorders in the Western world, and the disruption of male endocrinology has been suggested to play a central role. Several studies have shown that mild analgesics exposure during fetal life is associated with antiandrogenic effects and congenital malformations, but the effects on the adult man remain largely unknown. Through a clinical trial with young men exposed to ibuprofen, we show that the analgesic resulted in the clinical condition named "compensated hypogonadism," a condition prevalent among elderly men and associated with reproductive and physical disorders. In the men, luteinizing hormone (LH) and ibuprofen plasma levels were positively correlated, and the testosterone/LH ratio decreased. Using adult testis explants exposed or not exposed to ibuprofen, we demonstrate that the endocrine capabilities from testicular Leydig and Sertoli cells, including testosterone production, were suppressed through transcriptional repression. This effect was also observed in a human steroidogenic cell line. Our data demonstrate that ibuprofen alters the endocrine system via selective transcriptional repression in the human testes, thereby inducing compensated hypogonadism
Intrauterine exposure to mild analgesics is a risk factor for development of male reproductive disorders in human and rat
International audienceBACKGROUND: More than half of pregnant women in the Western world report intake of mild analgesics, and some of these drugs have been associated with anti-androgenic effects in animal experiments. Intrauterine exposure to anti-androgens is suspected to contribute to the recent increase in male reproductive problems, and many of the anti-androgenic compounds are like the mild analgesics potent inhibitors of prostaglandin synthesis. Therefore, it appears imperative to further investigate the potential endocrine disrupting properties of mild analgesics. METHODS: In a prospective birth cohort study, 2297 Danish and Finnish pregnant women completed a questionnaire and 491 of the Danish mothers participated in a telephone interview, reporting on their use of mild analgesics during pregnancy. The testicular position of newborns was assessed by trained paediatricians. In rats, the impact of mild analgesics on anogenital distance (AGD) after intrauterine exposure was examined together with the effect on ex vivo gestational day 14.5 testes. RESULTS: In the Danish birth cohort, the use of mild analgesics was dose-dependently associated with congenital cryptorchidism. In particular, use during the second trimester increased the risk. This risk was further increased after the simultaneous use of different analgesics. The association was not found in the Finnish birth cohort. Intrauterine exposure of rats to paracetamol led to a reduction in the AGD and mild analgesics accordingly reduced testosterone production in ex vivo fetal rat testes. CONCLUSION: There was an association between the timing and the duration of mild analgesic use during pregnancy and the risk of cryptorchidism. These findings were supported by anti-androgenic effects in rat models leading to impaired masculinization. Our results suggest that intrauterine exposure to mild analgesics is a risk factor for development of male reproductive disorders
Antiépileptiques et antalgiques pendant la grossesse et homéostasie du testicule foetal humain
Fetal development is a period that is particularly vulnerable to imbalances in the environment in which it takes place. The fetal testis plays a crucial role in the masculinization of the reproductive organs via its endocrine function, and any alteration can give rise to a range of malformations that can have an impact on a man's future fertility. During development, the embryo and then the fetus are exposed to a complex chemical environment known as the maternal exposome. Among the families of substances that make up the exposome are the medicines that pregnant women take to treat a chronic pathology or acutely to treat a pregnancy-related symptom. We are interested in two classes of drugs: anti-epileptics (AEs) on the one hand, and analgesics on the other, because epidemiological studies have reported an increased risk of hypospadias in newborns exposed in utero to valproic acid, an AE, and of malformations of the reproductive system in those exposed to paracetamol and ibuprofen in particular. The occurrence of these alterations could be linked to disturbances in hormonal balance. We used an organotypic culture model of human fetal testicular explants to compare the disruption profiles generated by a short exposure - 3 days - to analgesics and a short and long exposure - 28 days - to AEs. To do this, we adapted and optimized our model to approximate the chronicity of treatment in vivo. These studies, using organotypic cultures of human fetal testes, showed that three AEs could, over a more or less long period, induce an alteration in the endocrine function of this organ, leaving open the possibility that with chronic treatment, the androgenic impregnation of the fetus could be affected, and that this could have consequences for the target organs. Although the NSAID analgesics studied appear to have less spectacular effects on the endocrine function of the developing human fetal testis, their use during pregnancy continues to present a risk for other organs whose development is sensitive to or dependent on prostaglandins.Le développement fœtal est une période particulièrement vulnérable aux déséquilibres du milieu dans lequel il se déroule. Le testicule fœtal joue un rôle capital dans la masculinisation des organes reproducteurs via sa fonction endocrine, et toute altération peut engendrer un spectre de malformations pouvant impacter la fertilité future de l’homme. Au cours du développement, l’embryon puis le fœtus va être exposé à un l’environnement chimique complexe qu’est l’exposome maternel. Parmi les familles de substances constituant l’exposome se trouvent les médicaments que la femme enceinte consomme pour soigner une pathologie chronique ou de façon aigue pour traiter un symptôme lié à la grossesse. Nous nous sommes intéressés à deux classes de médicament : les antiépileptiques (AEs) d’une part, et les antalgiques d’autre part car des études épidémiologiques ont rapporté un risque accru d’hypospadias chez les nouveau-nés exposés in utero à l’acide valproïque, un AE, et de malformations de l’appareil reproducteur chez ceux exposés au paracétamol et à l’ibuprofène notamment. Or la survenue de ces altérations pourrait être liée à des perturbations de l’équilibre hormonal. Nous avons utilisé un modèle de culture organotypique d’explants testiculaires fœtaux humains afin de comparer les profils de perturbation générés par une exposition courte, de 3 jours, aux antalgiques et une exposition courte et longue - 28 jours - pour les AEs. Pour cela, nous avons adapté et optimisé notre modèle pour nous rapprocher de la chronicité du traitement in vivo. Ces études utilisant des cultures organotypiques de testicules fœtaux humains ont permis de démontrer que trois AEs pouvaient à plus ou moins longue échéance induire une altération de la fonction endocrine de cet organe, ce qui laisse ouverte la possibilité qu’avec un traitement chronique, l’imprégnation androgénique du fœtus puisse être affectée, et que cela puisse avoir des conséquences sur les organes cibles. Pour les antalgiques de la famille des AINS étudiés, s’ils semblent avoir des effets moins spectaculaires sur la fonction endocrine du testicule fœtal humain en développement, leur utilisation pendant la grossesse continue de présenter un risque sur d’autres organes dont le développement est sensible ou dépend des prostaglandines
Antiépileptiques et antalgiques pendant la grossesse et homéostasie du testicule foetal humain
Fetal development is a period that is particularly vulnerable to imbalances in the environment in which it takes place. The fetal testis plays a crucial role in the masculinization of the reproductive organs via its endocrine function, and any alteration can give rise to a range of malformations that can have an impact on a man's future fertility. During development, the embryo and then the fetus are exposed to a complex chemical environment known as the maternal exposome. Among the families of substances that make up the exposome are the medicines that pregnant women take to treat a chronic pathology or acutely to treat a pregnancy-related symptom. We are interested in two classes of drugs: anti-epileptics (AEs) on the one hand, and analgesics on the other, because epidemiological studies have reported an increased risk of hypospadias in newborns exposed in utero to valproic acid, an AE, and of malformations of the reproductive system in those exposed to paracetamol and ibuprofen in particular. The occurrence of these alterations could be linked to disturbances in hormonal balance. We used an organotypic culture model of human fetal testicular explants to compare the disruption profiles generated by a short exposure - 3 days - to analgesics and a short and long exposure - 28 days - to AEs. To do this, we adapted and optimized our model to approximate the chronicity of treatment in vivo. These studies, using organotypic cultures of human fetal testes, showed that three AEs could, over a more or less long period, induce an alteration in the endocrine function of this organ, leaving open the possibility that with chronic treatment, the androgenic impregnation of the fetus could be affected, and that this could have consequences for the target organs. Although the NSAID analgesics studied appear to have less spectacular effects on the endocrine function of the developing human fetal testis, their use during pregnancy continues to present a risk for other organs whose development is sensitive to or dependent on prostaglandins.Le développement fœtal est une période particulièrement vulnérable aux déséquilibres du milieu dans lequel il se déroule. Le testicule fœtal joue un rôle capital dans la masculinisation des organes reproducteurs via sa fonction endocrine, et toute altération peut engendrer un spectre de malformations pouvant impacter la fertilité future de l’homme. Au cours du développement, l’embryon puis le fœtus va être exposé à un l’environnement chimique complexe qu’est l’exposome maternel. Parmi les familles de substances constituant l’exposome se trouvent les médicaments que la femme enceinte consomme pour soigner une pathologie chronique ou de façon aigue pour traiter un symptôme lié à la grossesse. Nous nous sommes intéressés à deux classes de médicament : les antiépileptiques (AEs) d’une part, et les antalgiques d’autre part car des études épidémiologiques ont rapporté un risque accru d’hypospadias chez les nouveau-nés exposés in utero à l’acide valproïque, un AE, et de malformations de l’appareil reproducteur chez ceux exposés au paracétamol et à l’ibuprofène notamment. Or la survenue de ces altérations pourrait être liée à des perturbations de l’équilibre hormonal. Nous avons utilisé un modèle de culture organotypique d’explants testiculaires fœtaux humains afin de comparer les profils de perturbation générés par une exposition courte, de 3 jours, aux antalgiques et une exposition courte et longue - 28 jours - pour les AEs. Pour cela, nous avons adapté et optimisé notre modèle pour nous rapprocher de la chronicité du traitement in vivo. Ces études utilisant des cultures organotypiques de testicules fœtaux humains ont permis de démontrer que trois AEs pouvaient à plus ou moins longue échéance induire une altération de la fonction endocrine de cet organe, ce qui laisse ouverte la possibilité qu’avec un traitement chronique, l’imprégnation androgénique du fœtus puisse être affectée, et que cela puisse avoir des conséquences sur les organes cibles. Pour les antalgiques de la famille des AINS étudiés, s’ils semblent avoir des effets moins spectaculaires sur la fonction endocrine du testicule fœtal humain en développement, leur utilisation pendant la grossesse continue de présenter un risque sur d’autres organes dont le développement est sensible ou dépend des prostaglandines
Mono-(2-ethylhexyl) phthalate directly alters the expression of Leydig cell genes and CYP17 lyase activity in cultured rat fetal testis.
International audienceExposure to phthalates in utero alters fetal rat testis gene expression and testosterone production, but much remains to be done to understand the mechanisms underlying the direct action of phthalate within the fetal testis. We aimed to investigate the direct mechanisms of action of mono-(2-ethylhexyl) phthalate (MEHP) on the rat fetal testis, focusing on Leydig cell steroidogenesis in particular. We used an in vitro system based on the culture for three days, with or without MEHP, of rat fetal testes obtained at 14.5 days post-coitum.Exposure to MEHP led to a dose-dependent decrease in testosterone production. Moreover, the production of 5 alpha-dihydrotestosterone (5α-DHT) (-68%) and androstenedione (-54%) was also inhibited by 10 µM MEHP, whereas 17 alpha-hydroxyprogesterone (17α-OHP) production was found to increase (+41%). Testosterone synthesis was rescued by the addition of androstenedione but not by any of the other precursors used. Thus, the hormone data suggested that steroidogenesis was blocked at the level of the 17,20 lyase activity of the P450c17 enzyme (CYP17), converting 17α-OHP to androstenedione. The subsequent gene expression and protein levels supported this hypothesis. In addition to Cyp17a1, microarray analysis showed that several other genes important for testes development were affected by MEHP. These genes included those encoding insulin-like factor 3 (INSL3), which is involved in controlling testicular descent, and Inha, which encodes the alpha subunit of inhibin B.These findings indicate that under in vitro conditions known to support normal differentiation of the fetal rat testis, the exposure to MEHP directly inhibits several important Leydig cell factors involved in testis function and that the Cyp17a1 gene is a specific target to MEHP explaining the MEHP-induced suppression of steroidogenesis observed
Parallel assessment of BPA and BPA-substitutes on the human Leydig cell function
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