RESUMO
The objective was to investigate effects of progesterone (P4) dose on abundance of luteinizing hormone receptor (LHCGR), aromatase (CYP19A1), 3ß-hydroxysteroid dehydrogenase (HSD3B1), and other steroidogenic mRNA transcripts in granulosa cells from dominant follicles. Nellore heifers were assigned to one of six groups: new, first-use controlled internal drug release device (CIDR1) inserted for 5 days (Large-P4-dose-D5; n = 7) or 6 days (Large-P4-dose-D6; n = 8), prostaglandin (PG)F2α administered on D0 and 1 previously-used CIDR (CIDR3) inserted for 5 days (Small- P4-dose-D5; n = 8) or 6 days (Small-P4-dose-D6; n = 8), CIDR1 inserted on D0 and removed plus PGF2α on D5 (Large-P4-dose-proestrus (PE); n = 7), and CIDR3 and PGF2α on D0 and 1, CIDR3 removed plus PGF2α on D5 (Small-P4-dose-PE; n = 7). Duration of P4 treatment (D5 compared to D6) affected abundances of CYP19A1 mRNA transcripts, with there being greater abundances on D6 than D5 (P ≤ 0.05). Heifers treated with the large dose of P4 had a smaller dominant follicle, less serum and intra-follicular estradiol (E2) concentrations (P ≤ 0.05) and lesser LHCGR, CYP19A1, and HSD3B1 transcript abundances (P ≤ 0.05). Heifers treated to induce PE had a larger follicle diameter (P = 0.09), greater intra-follicular E2 concentrations and larger abundances of CYP19A1 mRNA transcript (P ≤ 0.05) than heifers of the D6 group. Overall, treatment with larger doses of P4 resulted in lesser abundances of LHCGR, HSD3B1, and CYP19A1 mRNA transcripts; thus, potentially leading to development of smaller dominant follicles and lesser E2 concentrations.
Assuntos
Bovinos , Sincronização do Estro/efeitos dos fármacos , Progesterona/farmacologia , Receptores do LH/metabolismo , Animais , Aromatase/genética , Aromatase/metabolismo , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Dinoprosta/administração & dosagem , Dinoprosta/análogos & derivados , Dinoprosta/farmacologia , Estradiol/administração & dosagem , Estradiol/análogos & derivados , Estradiol/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Células da Granulosa/efeitos dos fármacos , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Progesterona/administração & dosagem , Progesterona Redutase/genética , Progesterona Redutase/metabolismo , Receptores do LH/genética , Esteroide Isomerases/genética , Esteroide Isomerases/metabolismoRESUMO
3ßHSD2 enzyme is crucial for adrenal and gonad steroid biosynthesis. In enzyme deficiency states, due to recessive loss-of-function HSD3B2 mutations, steroid flux is altered and clinical manifestations result. Deficiency of 3ßHSD2 activity in the adrenals precludes normal aldosterone and cortisol synthesis and the alternative backdoor and 11-oxygenated C19 steroid pathways and the flooding of cortisol precursors along the Δ5 pathway with a marked rise in DHEA and DHEAS production. In gonads, it precludes normal T and estrogen synthesis. Here, we review androgen-dependent male differentiation of the external genitalia in humans and link this to female development and steroidogenesis in the developing adrenal cortex. The molecular mechanisms governing postnatal adrenal cortex zonation and ZR development were also revised. This chapter will review relevant clinical, hormonal, and genetic aspects of 3ßHSD2 deficiency with emphasis on the significance of alternate fates encountered by steroid hormone precursors in the adrenal gland and gonads. Our current knowledge of the process of steroidogenesis and steroid action is derived from pathological conditions. In humans the 3ßHSD2 deficiency represents a model of nature that reinforces our knowledge about the role of the steroidogenic alternative pathway in sex differentiation in both sexes. However, the physiological role of the high serum DHEAS levels in fetal life as well as after adrenarche remains to be elucidated.
Assuntos
Desidroepiandrosterona/metabolismo , Progesterona Redutase/genética , Regulação da Expressão Gênica , Genótipo , Humanos , Progesterona Redutase/deficiência , Desenvolvimento Sexual/genética , Desenvolvimento Sexual/fisiologiaRESUMO
The participation of aberrant receptors and intra-adrenal ACTH in hyperplastic tissue are considered mechanisms that regulate hypercortisolism in PMAH. Additionally, germline ARMC5 mutations have been described as the most frequent genetic abnormality found in patients diagnosed with PMAH. Previous functional studies analyzed ARMC5 role using H295R cells. Therefore, we investigated the role of ARMC5 in cell cultures obtained from PMAH nodules containing steroidogenic cells, aberrant receptors and intra-adrenal ACTH. ARMC5 silencing in non-mutated PMAH cell cultures decreased steroidogenesis-related genes and increased CCNE1 mRNA expression and proliferative capacity without affecting cell viability. Additionally, ARMC5 overexpression induced cell death in PMAH mutated cell cultures, thereby decreasing cell viability. We confirmed the role of ARMC5 as an important pro-apoptotic protein involved in PMAH-related steroidogenesis. We also report for the first time the involvement of ARMC5 in controlling proliferation and regulating cell cycle in PMAH cell cultures; these effects need to be explored further.
Assuntos
Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Proteínas Supressoras de Tumor/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Idoso , Proteínas do Domínio Armadillo , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Hiperplasia , Gotículas Lipídicas/efeitos dos fármacos , Gotículas Lipídicas/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação/genética , Pró-Opiomelanocortina/metabolismo , Progesterona Redutase/genética , Progesterona Redutase/metabolismo , Receptor Tipo 2 de Melanocortina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Análise de Sequência de DNA , Coloração e Rotulagem , Esteroide 17-alfa-Hidroxilase/genética , Esteroide 17-alfa-Hidroxilase/metabolismo , Proteínas Supressoras de Tumor/genética , Vasopressinas/farmacologiaRESUMO
CONTEXT: 3ßHSD2 is a bifunctional microsomal NAD+-dependent enzyme crucial for adrenal and gonad steroid biosynthesis, converting Δ5-steroids to Δ4-steroids. 3ßHSD2 deficiency is a rare cause of congenital adrenal hyperplasia caused by recessive loss-of-function HSD3B2 mutations. OBJECTIVE: The aim was to define the pathogenic consequences of a novel missense mutation in the HSD3B2 gene. PATIENT: We report a 7-month-old 46,XX girl referred because of precocious pubarche and postnatal clitoromegaly. Hormonal profile showed inadequate glucocorticoid levels, increased 17OHP and renin levels, and very high DHEAS levels, suggestive of compensated nonsalt-losing 3ßHSD2 deficiency. DESIGN AND RESULTS: Direct sequencing revealed a novel, homozygous, pG250V HSD3B2 mutation. In vitro analysis in intact COS-7 cells showed impaired enzymatic activity for the conversion of pregnenolone to progesterone and dehydroepiandrosterone to androstenedione (20% and 27% of WT at 6 h, respectively). G250V-3ßHSD2 decreased the Vmax for progesterone synthesis without affecting the Km for pregnenolone. Western blot and immunofluorescence suggested that p.G250V mutation has no effect on the expression and intracellular localization of the mutant protein. Molecular homology modeling predicted that mutant V250 affected an L239-Q251 loop next to a ß-sheet structure in the NAD+-binding domain. CONCLUSIONS: We identified a novel p.G250V mutation of HSD3B2 which causes an incomplete loss of enzymatic activity, explaining the compensated nonsalt loss phenotype. In vitro and in silico experiments provided insight into the structure-function relationship of the 3ßHSD2 protein suggesting the importance of the L239-Q251 loop for the catalytic activity of the otherwise stable 3ßHSD2 enzyme.
Assuntos
Hiperplasia Suprarrenal Congênita/genética , Mutação de Sentido Incorreto , Progesterona Redutase/genética , Puberdade Precoce/genética , Hiperplasia Suprarrenal Congênita/metabolismo , Feminino , Humanos , Lactente , Progesterona Redutase/metabolismo , Puberdade Precoce/metabolismo , Relação Estrutura-AtividadeRESUMO
3ß-hydroxysteroid dehydrogenase II (3ß-HSD) deficiency represents a rare CAH variant. Newborns affected with its classic form have salt wasting in early infancy and genital ambiguity in both sexes. High levels of 17-hydroxypregnenolone (Δ517OHP) are characteristic, but extra-adrenal conversion to 17-hydroxyprogesterone (17OHP) may lead to positive results on newborn screening tests. Filter paper 17OHP on newborn screening test was performed by immunofluorometric assay, and serum determinations of 17OHP and Δ517OHP, by radioimmunoassay. A 46,XY infant with genital ambiguity and adrenal crisis at three months of age presented a positive result on newborn screening for CAH. Serum determinations of 17OHP and Δ517OHP were elevated, and a high Δ517OHP/cortisol relation was compatible with the diagnosis of 3ß-HSD deficiency. Molecular analysis of the HSD3B2 gene from the affected case revealed the presence of the homozygous p.P222Q mutation, whereas his parents were heterozygous for it. We present the first report of 3ß-HSD type II deficiency genotype-proven detected at the Newborn Screening Program in Brazil. The case described herein corroborates the strong genotype-phenotype correlation associated with the HSD3B2 p.P222Q mutation, which leads to a classic salt-wasting 3ß-HSD deficiency. Further evaluation of 17OHP assays used in newborn screening tests would aid in determining their reproducibility, as well as the potential significance of moderately elevated 17OHP levels as an early indicator to the diagnosis of other forms of classic CAH, beyond 21-hydroxylase deficiency.
Assuntos
17-alfa-Hidroxipregnenolona/sangue , Hiperplasia Suprarrenal Congênita/diagnóstico , Triagem Neonatal/métodos , Progesterona Redutase/deficiência , Transtornos do Desenvolvimento Sexual , Homozigoto , Humanos , Recém-Nascido , Masculino , Mutação , Progesterona Redutase/genética , Doenças RarasRESUMO
3b-hydroxysteroid dehydrogenase II (3β-HSD) deficiency represents a rare CAH variant. Newborns affected with its classic form have salt wasting in early infancy and genital ambiguity in both sexes. High levels of 17-hydroxypregnenolone (Δ517OHP) are characteristic, but extra-adrenal conversion to 17-hydroxyprogesterone (17OHP) may lead to positive results on newborn screening tests. Filter paper 17OHP on newborn screening test was performed by immunofluorometric assay, and serum determinations of 17OHP and Δ517OHP, by radioimmunoassay. A 46,XY infant with genital ambiguity and adrenal crisis at three months of age presented a positive result on newborn screening for CAH. Serum determinations of 17OHP and Δ517OHP were elevated, and a high Δ517OHP/cortisol relation was compatible with the diagnosis of 3β-HSD deficiency. Molecular analysis of the HSD3B2 gene from the affected case revealed the presence of the homozygous p.P222Q mutation, whereas his parents were heterozygous for it. We present the first report of 3β-HSD type II deficiency genotype-proven detected at the Newborn Screening Program in Brazil. The case described herein corroborates the strong genotype-phenotype correlation associated with the HSD3B2 p.P222Q mutation, which leads to a classic salt-wasting 3β-HSD deficiency. Further evaluation of 17OHP assays used in newborn screening tests would aid in determining their reproducibility, as well as the potential significance of moderately elevated 17OHP levels as an early indicator to the diagnosis of other forms of classic CAH, beyond 21-hydroxylase deficiency.
A deficiência da enzima 3β-hidroxiesteroide desidrogenase tipo 2 (3β-HSD) representa variante rara de hiperplasia adrenal congenital (HAC). Recém-nascidos afetados com a forma clássica apresentam perda de sal nas primeiras semanas de vida e ambiguidade genital em ambos os sexos. Concentrações elevadas de 17-hidroxipregnenolona (Δ517OHP) são características, porém sua conversão extra-adrenal a 17-hidroxiprogesterona (17OHP) pode resultar em resultados positivos no teste de triagem neonatal. A determinação da concentração de 17OHP obtida em amostra de sangue colhida em papel-filtro para triagem neonatal foi realizada por ensaio imunofluorimétrico, e as concentrações séricas de 17OHP and Δ517OHP, por radioimunoensaio. Um menino, 46,XY, com ambiguidade genital e crise adrenal aos 3 meses de vida, apresentou teste positivo na triagem neonatal para HAC. As concentrações séricas de 17OHP e Δ517OHP estavam aumentadas, bem como a relação Δ517OHP/cortisol, o que foi compatível com o diagnóstico de deficiência de 3β-HSD. A análise molecular do gene HSD3B2 revelou a mutação p.P222Q em homozigose na criança afetada e em heterozigose em seus pais, o que confirmou a deficiência de 3β-HSD com resultado moderadamente elevado na dosagem de 17OHP no “Teste do Pezinho” (Programa de Triagem Neonatal do Distrito Federal, Brasil). Esse caso corrobora a forte correlação genótipo-fenótipo associada à mutação p.P222Q no gene HSD3B2. Estudos futuros para avaliação dos ensaios utilizados na triagem neonatal para determinação de 17OHP poderão auxiliar na determinação do significado potencial de concentrações moderadamente elevadas de 17OHP como um indicador precoce para o diagnóstico de outras formas de HAC clássicas, além da deficiência de 21-hidroxilase.
Assuntos
Humanos , Recém-Nascido , Masculino , /sangue , Hiperplasia Suprarrenal Congênita/diagnóstico , Triagem Neonatal/métodos , Progesterona Redutase/deficiência , Transtornos do Desenvolvimento Sexual , Homozigoto , Mutação , Progesterona Redutase/genética , Doenças RarasRESUMO
Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17ß-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures.
Assuntos
Meios de Cultura/farmacologia , Estradiol/farmacologia , Folículo Ovariano/efeitos dos fármacos , Progesterona/farmacologia , Técnicas de Cultura de Tecidos , Análise de Variância , Animais , Aromatase/genética , Bovinos , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Meios de Cultura Livres de Soro , Feminino , Expressão Gênica , Folículo Ovariano/anatomia & histologia , Fosfoproteínas/genética , Progesterona Redutase/genética , Receptores do FSH/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Esteroide 17-alfa-Hidroxilase/genéticaRESUMO
Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17β-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures.
Assuntos
Animais , Bovinos , Feminino , Meios de Cultura/farmacologia , Estradiol/farmacologia , Folículo Ovariano/efeitos dos fármacos , Progesterona/farmacologia , Técnicas de Cultura de Tecidos , Análise de Variância , Aromatase/genética , Meios de Cultura Livres de Soro , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Expressão Gênica , Folículo Ovariano/anatomia & histologia , Fosfoproteínas/genética , Progesterona Redutase/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptores do FSH/genética , /genéticaRESUMO
Type II 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase (3β-HSD2), encoded by the HSD3B2 gene, is a key enzyme involved in the biosynthesis of all the classes of steroid hormones. Deleterious mutations in the HSD3B2 gene cause the classical deficiency of 3β-HSD2, which is a rare autosomal recessive disease that leads to congenital adrenal hyperplasia (CAH). CAH is the most frequent cause of ambiguous genitalia and adrenal insufficiency in newborn infants with variable degrees of salt losing. Here we report the molecular and structural analysis of the HSD3B2 gene in a 46,XY child, who was born from consanguineous parents, and presented with ambiguous genitalia and salt losing. The patient carries a homozygous nucleotide c.665C>A change in exon 4 that putatively substitutes the proline at codon 222 for glutamine. Molecular homology modeling of normal and mutant 3β-HSD2 enzymes emphasizes codon 222 as an important residue for the folding pattern of the enzyme and validates a suitable model for analysis of new mutations.
A enzima 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase do tipo 2 (3β-HSD2), codificada pelo gene HSD3B2, é importante na biossíntese de todas as classes de hormônios esteroides. As mutações no gene HSD3B2 podem causar deficiência da 3β-HSD2 da forma clássica. É de herança autossômica recessiva e uma das causas mais raras de hiperplasia congênita da adrenal (HCA). A deficiência dessa enzima leva frequentemente à ambiguidade genital e à insuficiência da adrenal em recém-nascidos com vários níveis de perda de sal. Neste trabalho, foi feito o estudo estrutural e molecular do gene HSD3B2 gene em um paciente 46,XY, filho de pais consanguíneos, com ambiguidade genital e perda de sal. O paciente é homozigoto para a troca nucleotídica c.665C>A no éxon 4, que putativamente leva à substituição de uma prolina do códon 222 por uma glutamina. A modelagem molecular por homologia das enzimas 3β-HSD2 normal e mutantes ressaltou que a prolina no códon 222 é um resíduo importante no enovelamento da enzima e validou um modelo adequado para avaliações de novas mutações.
Assuntos
Humanos , Recém-Nascido , Masculino , /deficiência , Hiperplasia Suprarrenal Congênita/genética , Progesterona Redutase/genética , /genética , Códon , Homozigoto , Mutação de Sentido IncorretoRESUMO
Type II 3ß-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase (3ß-HSD2), encoded by the HSD3B2 gene, is a key enzyme involved in the biosynthesis of all the classes of steroid hormones. Deleterious mutations in the HSD3B2 gene cause the classical deficiency of 3ß-HSD2, which is a rare autosomal recessive disease that leads to congenital adrenal hyperplasia (CAH). CAH is the most frequent cause of ambiguous genitalia and adrenal insufficiency in newborn infants with variable degrees of salt losing. Here we report the molecular and structural analysis of the HSD3B2 gene in a 46,XY child, who was born from consanguineous parents, and presented with ambiguous genitalia and salt losing. The patient carries a homozygous nucleotide c.665C>A change in exon 4 that putatively substitutes the proline at codon 222 for glutamine. Molecular homology modeling of normal and mutant 3ß-HSD2 enzymes emphasizes codon 222 as an important residue for the folding pattern of the enzyme and validates a suitable model for analysis of new mutations.