RESUMO
In animal models, exposure to excess testosterone during gestation induces polycystic ovary syndrome (PCOS)-like reproductive and metabolic traits in female offspring, suggesting that the hyperandrogenemic intrauterine environment may have a role in the etiology of PCOS. Additionally, few studies have also addressed metabolic and reproductive outcomes in male offspring. In the present study, the intravenous glucose tolerance test (IGTT) was used to assess the insulin-glucose homeostasis at various ages during sexual development in male sheep born to testosterone-treated ewes. To further analyze the programming effect of testosterone on insulin-glucose homeostasis, indexes of insulin sensitivity were assessed in orchidectomized post-pubertal males born to testosterone-treated ewes (Torq-males) and orchidectomized post-puberal controls (Corq-males) before and 48 h after a testosterone injection. There was no difference in insulin sensitivity indexes between males born to testosterone-treated ewes (T-males) and control males born to control ewes (C-males) at 5, 10, 20 and 30 weeks of age, representing the infantile, early and late pre-pubertal, and early post-pubertal stage of sexual development, respectively. In orchidectomized males, basal levels of insulin and glucose were not different between both groups before and after the testosterone injection; however, Torq-males released more insulin before and after T challenge during the first 20 min of the test. Despite this, plasma glucose concentrations were not different in both groups during IVGTT, resulting in an insulin sensitivity index composite similar between groups. We concluded that the effect of prenatal exposure to excess testosterone may reprogram the pancreatic ß-cells insulin release in ovine males, with effects more evident in castrated males versus intact males.
Assuntos
Desenvolvimento Fetal , Resistência à Insulina , Exposição Materna , Efeitos Tardios da Exposição Pré-Natal , Testosterona , Animais , Feminino , Masculino , Orquiectomia , Gravidez , Maturidade Sexual , OvinosRESUMO
Clinical and experimental evidences indicate that epigenetic modifications induced by the prenatal environment are related to metabolic and reproductive derangements in polycystic ovary syndrome (PCOS). Alterations in the leptin and adiponectin systems, androgen signalling and antimüllerian hormone (AMH) levels have been observed in PCOS women and in their offspring. Using a targeted Next-Generation Sequencing (NGS), we studied DNA methylation in promoter regions of the leptin (LEP), leptin receptor (LEPR), adiponectin (ADIPOQ), adiponectin receptor 1 and 2 (ADIPOR1 and ADIPOR2), AMH and androgen receptor (AR) genes in 24 sons and daughters of women with PCOS (12 treated with metformin during pregnancy) and 24 children born to non-PCOS women during early infancy (2-3 months of age). Genomic DNA was extracted from whole blood, bisulphite converted and sequenced by NGS. Girls showed differences between groups in 1 CpG site of LEPR, 2 of LEP, 1 of ADIPOR2 and 2 of AR. Boys showed differences in 5 CpG sites of LEP, 3 of AMH and 9 of AR. Maternal metformin treatment prevented some of these changes in LEP, ADIPOR2 and partially in AR in girls, and in LEP and AMH in boys. Maternal BMI at early pregnancy was inversely correlated with the methylation levels of the ChrX-67544981 site in the whole group of girls (r = -0.530, p = 0.008) and with the global Z-score in all boys (r = -0.539, p = 0.007). These data indicate that the intrauterine PCOS environment predisposes the offspring to acquire certain sex-dependent DNA methylation patterns in the promoter regions of metabolic and reproductive genes.
Assuntos
Metilação de DNA , Epigênese Genética , Síndrome do Ovário Policístico/genética , Efeitos Tardios da Exposição Pré-Natal/genética , Adiponectina/genética , Adiponectina/metabolismo , Adulto , Feminino , Humanos , Lactente , Leptina/genética , Leptina/metabolismo , Masculino , Gravidez , Regiões Promotoras Genéticas , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Receptores para Leptina/genética , Receptores para Leptina/metabolismoRESUMO
Hyperandrogenemia and metabolic disturbances during postnatal life are strongly linked both to polycystic ovary syndrome and other conditions that arise from prenatal exposure to androgen excess. In an animal model of this condition, we reported that insulin sensitivity (IS) was lower in young female sheep born to testosterone-treated mothers versus sheep born to non-exposed mothers (control). This lower insulin sensitivity remains throughout reproductive life. However, it is unknown whether abnormal postnatal levels of testosterone (T) further decrease IS derived from prenatal exposure to testosterone. Therefore, we assessed the effects of an acute testosterone administration (40 mg) on IS and insulin secretion during an intravenous glucose tolerance test performed at 40 weeks of age (adulthood) in previously ovariectomized sheep at 26 weeks of age (prepuberty), that were either prenatally exposed to testosterone (T-females, n = 6) or not (C-females, n = 6). The incremental area under the curve of insulin was greater in C-females both with or without the acute testosterone treatment (P < 0.05). The ISI-Composite was lower after an acute testosterone treatment, only in T-females. We conclude that prenatal exposure to testosterone disrupts pancreatic insulin secretion in response to glucose and that in this setting further hyperandrogenemia may predispose to lower insulin sensitivity.
Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Resistência à Insulina , Secreção de Insulina/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/patologia , Testosterona/efeitos adversos , Animais , Feminino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/metabolismo , OvinosRESUMO
The administration of testosterone to pregnant sheep to resemble fetal programming of the polycystic ovary syndrome could alter other hormones/factors of maternal origin with known effects on fetal growth. Hence, we studied the weekly profile of insulin, progesterone and glucose during a treatment with testosterone propionate given biweekly from weeks 5 to 17 of pregnancy (term at 21 weeks) and checked the outcome of their fetuses at 17 weeks of gestation after C-section. Control dams were only exposed to the vehicle of the hormone. The testosterone administration did not cause any significant change in the maternal weekly profile of insulin, progesterone or glucose concentration, although the plasma levels of testosterone in the treated dams were inversely correlated to the levels of progesterone. Testosterone treatment also induced an inverse correlation between mean maternal insulin levels and fetal insulin levels; however, the fetal zoometric parameters, body weight, or insulin levels did not differ between exposed and not exposed fetuses. Therefore, treatment with testosterone during pregnancy does not cause significant impact on insulin levels in the mother, leading to less effect on the programming of fetal growth.
Assuntos
Glicemia/metabolismo , Insulina/sangue , Síndrome do Ovário Policístico/patologia , Efeitos Tardios da Exposição Pré-Natal/sangue , Testosterona/farmacologia , Animais , Animais Recém-Nascidos , Glicemia/análise , Glicemia/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Feto/efeitos dos fármacos , Feto/metabolismo , Síndrome do Ovário Policístico/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/veterinária , Ovinos , Fatores de TempoRESUMO
Polycystic ovarian syndrome (PCOS) is an endocrine and metabolic dysfunction, highly prevalent in women in their reproductive years. Hyperandrogenism, oligo-ovulation, polycystic ovarian morphology are the main features of this syndrome. PCOS is a genetic disorder with a multifactorial etiology and has a strong link with environmental components. It is frequently associated with obesity and insulin resistance. Recently, epigenetic mechanisms have been involved in the pathogenesis of PCOS. Several studies showed that methylation in DNA and miRNAs is altered in women with PCOS in blood, serum, adipose tissue, granulose cells and theca. This evidence indicates that women with PCOS have a different epigenetic regulation, which might be triggered by an adverse intrauterine environment or by postnatal environmental elements such as diet and or obesity.
Assuntos
Metilação de DNA/genética , Epigênese Genética/genética , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Síndrome do Ovário Policístico/genética , Feminino , HumanosRESUMO
Polycystic ovarian syndrome (PCOS) is an endocrine and metabolic dysfunction, highly prevalent in women in their reproductive years. Hyperandrogenism, oligo-ovulation, polycystic ovarian morphology are the main features of this syndrome. PCOS is a genetic disorder with a multifactorial etiology and has a strong link with environmental components. It is frequently associated with obesity and insulin resistance. Recently, epigenetic mechanisms have been involved in the pathogenesis of PCOS. Several studies showed that methylation in DNA and miRNAs is altered in women with PCOS in blood, serum, adipose tissue, granulose cells and theca. This evidence indicates that women with PCOS have a different epigenetic regulation, which might be triggered by an adverse intrauterine environment or by postnatal environmental elements such as diet and or obesity.
Assuntos
Humanos , Feminino , Síndrome do Ovário Policístico/genética , Regulação Neoplásica da Expressão Gênica/genética , Metilação de DNA/genética , MicroRNAs/genética , Epigênese Genética/genéticaRESUMO
Prenatal exposure to excess testosterone induces reproductive disturbances in both female and male sheep. In females, it alters the hypothalamus-pituitary-ovarian axis. In males, prenatal testosterone excess reduces sperm count and motility. Focusing on males, this study tested whether pituitary LH responsiveness to GNRH is increased in prenatal testosterone-exposed males and whether testicular function is compromised in the testosterone-exposed males. Control males (n=6) and males born to ewes exposed to twice weekly injections of 30â mg testosterone propionate from days 30 to 90 and of 40 âmg testosterone propionate from days 90 to 120 of gestation (n=6) were studied at 20 and 30 weeks of age. Pituitary and testicular responsiveness was tested by administering a GNRH analog (leuprolide acetate). To complement the analyses, the mRNA expression of LH receptor (LHR) and that of steroidogenic enzymes were determined in testicular tissue. Basal LH and testosterone concentrations were higher in the testosterone-exposed-males. While LH response to the GNRH analog was higher in the testosterone-exposed males than in the control males, testosterone responses did not differ between the treatment groups. The testosterone:LH ratio was higher in the control males than in the testosterone-exposed males of 30 weeks of age, suggestive of reduced Leydig cell sensitivity to LH in the testosterone-exposed males. The expression of LHR mRNA was lower in the testosterone-exposed males, but the mRNA expression of steroidogenic enzymes did not differ between the groups. These findings indicate that prenatal testosterone excess has opposing effects at the pituitary and testicular levels, namely increased pituitary sensitivity to GNRH at the level of pituitary and decreased sensitivity of the testes to LH.
Assuntos
Hiperplasia Suprarrenal Congênita/metabolismo , Modelos Animais de Doenças , Hormônio Liberador de Gonadotropina/metabolismo , Hormônio Luteinizante/metabolismo , Hipófise/metabolismo , Testículo/metabolismo , Testosterona/metabolismo , Hiperplasia Suprarrenal Congênita/sangue , Hiperplasia Suprarrenal Congênita/etiologia , Animais , Animais Endogâmicos , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/agonistas , Hormônio Liberador de Gonadotropina/análogos & derivados , Leuprolida/farmacologia , Hormônio Luteinizante/sangue , Masculino , Hipófise/efeitos dos fármacos , Síndrome do Ovário Policístico/fisiopatologia , Gravidez , Complicações na Gravidez/fisiopatologia , Distribuição Aleatória , Receptores do LH/genética , Receptores do LH/metabolismo , Maturidade Sexual , Carneiro Doméstico , Esteroides/biossíntese , Testículo/efeitos dos fármacos , Testosterona/sangue , Propionato de TestosteronaRESUMO
The reprograming effects of prenatal testosterone (T) treatment on postnatal reproductive parameters have been studied extensively in females of several species but similar studies in males are limited. We recently found that prenatal T treatment increases Sertoli cell number and reduced spermatogenesis in adult rams. If such disruptions are manifested early in life and involve changes in testicular paracrine environment remain to be explored. This study addresses the impact of prenatal T excess on testicular parameters in infant males, including Sertoli cell number and expression of critical genes [FSH receptor (FSHR), androgen receptor (AR), transforming growth factor beta 1 (TGFB1), 3 (TGFB3), transforming growth factor beta type 1 receptor, (TGFBR1), and anti-Müllerian hormone (AMH)] modulating testicular function. At 4 week of age, male lambs born to dams treated with 30 mg of T propionate twice weekly from day 30 to 90, followed by 40 mg of T propionate from day 90 to 120 of pregnancy (T-males), had a higher number of Sertoli cells/testis (P = 0.035) than control males (C-males) born to dams treated with the vehicle. While no differences were observed in the expression of FSHR and TGFB3, testicular TGFBR1 expression was found to be lower in T-males (P = 0.03) compared to C-males. Expression level of AMH, TGFB1, and AR also tended to be lower in T-males. These findings provide evidence that impact of fetal exposure to T excess is evident early in postnatal life, mainly characterized by an increase in Sertoli cell number. This could explain the testicular dysfunction observed in adult rams.
Assuntos
Efeitos Tardios da Exposição Pré-Natal , Células de Sertoli/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testosterona/farmacologia , Animais , Contagem de Células , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Masculino , Gravidez , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Receptores do FSH/genética , Receptores do FSH/metabolismo , Células de Sertoli/citologia , Células de Sertoli/metabolismo , Ovinos , Espermatogênese/efeitos dos fármacos , Testículo/citologia , Testículo/crescimento & desenvolvimento , Testosterona/sangue , Fator de Crescimento Transformador beta3/genética , Fator de Crescimento Transformador beta3/metabolismoRESUMO
Exposure to excess testosterone (T) during fetal life has a profound impact on the metabolic and reproductive functions in the female's postnatal life. However, less is known about the effects of excess testosterone in males. The aim of the present study was to evaluate the impact (consequences) of an excess of T during fetal development on mature male testis. The testicular evaluation was by histological analysis and by determination of mRNA expression of the FSH receptor (FSH-R), transforming growth factor-ß type I receptor (TßR-I), and two members of the TGF-ß superfamily, transforming growth factor-ß3 (TGFß3) and anti-Müllerian hormone (AMH) in males born to mothers receiving an excess of T during pregnancy. At 42 wk of age, postpubertal males born to mothers treated with 30 mg of T propionate twice weekly from day 30 to 90, followed by 40 mg of T propionate from day 90 to 120 of pregnancy (T males), showed higher concentrations of FSH in response to a GnRH analog, a higher number of Sertoli cells/seminiferous tubule cross-section, and a lower number of germ cells/tubules (P < 0.05) than control males (C males) born to mothers treated with the vehicle. The mRNA expression of FSH-R and of TßR-I was higher in T males compared with C males (P < 0.05). Moreover, in T males, AMH expression level correlated negatively with the expression level of TGFß3. In C males, this latter correlation was not observed. These results suggest that prenatal exposure to an excess of T can negatively modify some histological and molecular characteristics of the mature testis.
Assuntos
Células Germinativas/metabolismo , Efeitos Tardios da Exposição Pré-Natal , Receptores do FSH/metabolismo , Células de Sertoli/metabolismo , Testículo/metabolismo , Testosterona/metabolismo , Análise de Variância , Animais , Contagem de Células , Feminino , Hormônio Foliculoestimulante/sangue , Células Germinativas/citologia , Células Germinativas/efeitos dos fármacos , Leuprolida/farmacologia , Masculino , Troca Materno-Fetal , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Radioimunoensaio , Receptores do FSH/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células de Sertoli/citologia , Células de Sertoli/efeitos dos fármacos , Ovinos , Testículo/efeitos dos fármacos , Testosterona/farmacologiaRESUMO
The reproductive system is extremely susceptible to insults from exposure to exogenous steroids during development. Excess prenatal testosterone exposure programs neuroendocrine, ovarian, and metabolic deficits in the female, features seen in women with polycystic ovary disease. The objective of this study was to determine whether prenatal testosterone excess also disrupts the male reproductive system, using sheep as a model system. The extent of reproductive disruption was tested by assessing sperm quantity and quality as well as Leydig cell responsiveness to human chorionic gonadotropin. Males born to mothers treated with 30 mg testosterone propionate twice weekly from d 30 to 90 and with 40 mg testosterone propionate from d 90 to 120 of pregnancy (T-males) showed a significant reduction (P < 0.05) in body weight, scrotal circumference, and sperm count compared with control males. Mean straight line velocity of sperms was also lower in T-males (P < 0.05). Circulating testosterone levels in response to the human chorionic gonadotropin did not differ between groups. These findings demonstrate that exposure to excess testosterone during fetal development has a negative impact on reproductive health of the male offspring, raising concerns relative to unintended human exposure to steroidal mimics in the environment.