RESUMEN
STUDY QUESTION: Can mutations of genes other than AMH or AMHR2, namely PPP1R12A coding myosin phosphatase, lead to persistent Müllerian duct syndrome (PMDS)? SUMMARY ANSWER: The detection of PPP1R12A truncation mutations in five cases of PMDS suggests that myosin phosphatase is involved in Müllerian regression, independently of the anti-Müllerian hormone (AMH) signaling cascade. WHAT IS KNOWN ALREADY: Mutations of AMH and AMHR2 are detectable in an overwhelming majority of PMDS patients but in 10% of cases, both genes are apparently normal, suggesting that other genes may be involved. STUDY DESIGN, SIZE, DURATION: DNA samples from 39 PMDS patients collected from 1990 to present, in which Sanger sequencing had failed to detect biallelic AMH or AMHR2 mutations, were screened by massive parallel sequencing. PARTICIPANTS/MATERIALS, SETTING, METHODS: To rule out the possibility that AMH or AMHR2 mutations could have been missed, all DNA samples of good quality were analyzed by targeted next-generation sequencing. Twenty-four samples in which the absence of AMH or AMHR2 biallelic mutations was confirmed were subjected to whole-exome sequencing with the aim of detecting variants of other genes potentially involved in PMDS. MAIN RESULTS AND THE ROLE OF CHANCE: Five patients out of 24 (21%) harbored deleterious truncation mutations of PP1R12A, the gene coding for the regulatory subunit of myosin phosphatase, were detected. In addition to PMDS, three of these patients presented with ileal and one with esophageal atresia. The congenital abnormalities associated with PMDS in our patients are consistent with those described in the literature for PPP1R12A variants and have never been described in cases of AMH or AMHR2 mutations. The role of chance is therefore extremely unlikely. LIMITATIONS, REASONS FOR CAUTION: The main limitation of the study is the lack of experimental validation of the role of PPP1R12A in Müllerian regression. Only circumstantial evidence is available, myosin phosphatase is required for cell mobility, which plays a major role in Müllerian regression. Alternatively, PPP1R12A mutations could affect the AMH transduction pathway. WIDER IMPLICATIONS OF THE FINDINGS: The study supports the conclusion that failure of Müllerian regression in males is not necessarily associated with a defect in AMH signaling. Extending the scope of molecular analysis should shed light upon the mechanism of the initial steps of male sex differentiation. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by la Fondation Maladies Rares, GenOmics 2021_0404 and la Fondation pour la Recherche Médicale, grant EQU201903007868. The authors report no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.
Asunto(s)
Trastorno del Desarrollo Sexual 46,XY , Humanos , Masculino , Fosfatasa de Miosina de Cadena Ligera/genética , Trastorno del Desarrollo Sexual 46,XY/genética , Hormona Antimülleriana/genética , Hormona Antimülleriana/metabolismo , ADNRESUMEN
Anti-Müllerian hormone (AMH) is a member of the TGF-ß family produced essentially by the supporting somatic cells of the testis. Initially known for its inhibiting role upon the development of female internal organs, AMH has been shown to exert many other effects namely upon germ cells. Circulating AMH reflects the ovarian reserve of young developing follicles and is used to evaluate the fertility potential in assisted reproduction. The signaling pathway of AMH is both similar and different from that of other members of the TGF-ß family. Like these, it signals through two distinct serine/threonine receptors, type 1 and type 2, that phosphorylate cytoplasmic effectors, the Smads. It also shares type 1 receptors and Smads with other members of the family. However, AMH is the only family member with its own, dedicated, ligand-specific type 2 receptor, AMHR2. The monogamic relationship between AMH and AMHR2 is supported by molecular studies of the Persistent Müllerian Duct Syndrome, characterized by the presence of Müllerian derivatives in otherwise normally virilized males: mutations of AMH or AMHR2 are clinically indistinguishable.
Asunto(s)
Trastorno del Desarrollo Sexual 46,XY , Hormonas Peptídicas , Hormona Antimülleriana/genética , Hormona Antimülleriana/metabolismo , Trastorno del Desarrollo Sexual 46,XY/genética , Trastorno del Desarrollo Sexual 46,XY/metabolismo , Femenino , Humanos , Masculino , Transducción de Señal/genética , Testículo/metabolismo , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Disorders of sex development (DSD) are conditions where genetic, gonadal, and/or internal/external genital sexes are discordant. In many cases, serum testosterone determination is insufficient for the differential diagnosis. Anti-Müllerian hormone (AMH), a glycoprotein hormone produced in large amounts by immature testicular Sertoli cells, may be an extremely helpful parameter. In undervirilized 46,XY DSD, AMH is low in gonadal dysgenesis while it is normal or high in androgen insensitivity and androgen synthesis defects. Virilization of a 46,XX newborn indicates androgen action during fetal development, either from testicular tissue or from the adrenals or placenta. Recognizing congenital adrenal hyperplasia is usually quite easy, but other conditions may be more difficult to identify. In 46,XX newborns, serum AMH measurement can easily detect the existence of testicular tissue, leading to the diagnosis of ovotesticular DSD. In sex chromosomal DSD, where the gonads are more or less dysgenetic, AMH levels are indicative of the amount of functioning testicular tissue. Finally, in boys with a persistent Müllerian duct syndrome, undetectable or very low serum AMH suggests a mutation of the AMH gene, whereas normal AMH levels orient toward a mutation of the AMH receptor.
Asunto(s)
Hormona Antimülleriana/sangre , Trastornos del Desarrollo Sexual/sangre , Femenino , Humanos , MasculinoRESUMEN
The persistent Müllerian duct syndrome (PMDS) is a 46,XY disorder of sexual development characterized by the persistence of Müllerian duct derivatives, uterus and tubes, in otherwise normally masculinized males. The condition, transmitted as a recessive autosomal trait, is usually due to mutations in either the anti-Müllerian hormone (AMH) gene or its main receptor. Many variants of these genes have been described, all targeting the coding sequences. We report the first case of PMDS due to a regulatory mutation. The AMH promoter contains two binding sites for steroidogenic factor 1 (SF1), one at -102 and the other at -228. Our patient carries a single base deletion at -225, significantly decreasing its capacity for binding SF1, as measured by the electrophoresis mobility shift assay. Furthermore, by linking the AMH promoter to the luciferase gene, we show that the transactivation capacity of the promoter is significantly decreased by the mutation, in contrast to the disruption of the -102 binding site. To explain the difference in impact we hypothesize that SF1 could partially overcome the lack of binding to the -102 binding site by interacting with a GATA4 molecule linked to a nearby response element. We show that disruption of both the -102 SF1 and the -84 GATA response elements significantly decreases the transactivation capacity of the promoter. In conclusion, we suggest that the distance between mutated SF1 sites and potentially rescuing GATA binding motifs might play a role in the development of PMDS.
Asunto(s)
Hormona Antimülleriana/química , Hormona Antimülleriana/metabolismo , Trastorno del Desarrollo Sexual 46,XY/genética , Mutación , Factores de Empalme de ARN/metabolismo , Receptores de Péptidos/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Hormona Antimülleriana/genética , Sitios de Unión/genética , Línea Celular , Niño , Preescolar , Femenino , Humanos , Recién Nacido , Masculino , Linaje , Regiones Promotoras Genéticas , Unión ProteicaRESUMEN
Anti-Müllerian hormone (AMH) is a member of the TGF-ß family secreted by immature Sertoli cells and by granulosa cells of growing ovarian follicles. In males, it induces the regression of fetal Müllerian ducts and represses androgen synthesis through receptors located on the Leydig cell membrane. In female mice, AMH inhibits primary follicle recruitment and sensitivity to FSH. Measurement of circulating AMH is of value to pediatric endocrinologists allowing them to detect the presence and functional activity of testicular tissue without resorting to stimulation by human chorionic gonadotropin. In women, AMH levels are correlated with the size of the ovarian follicle pool and provide information on the likelihood of spontaneous or induced pregnancy.
Asunto(s)
Hormona Antimülleriana/historia , Investigación Biomédica/historia , Modelos Animales de Enfermedad , Glicoproteínas/metabolismo , Ovario/fisiología , Reproducción , Células de Sertoli/fisiología , Animales , Femenino , Francia , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Masculino , Ratones , Ovario/citología , Embarazo , Células de Sertoli/citologíaRESUMEN
Male sex differentiation is driven by two hormones, testosterone and anti-Müllerian hormone (AMH), responsible for regression of Müllerian ducts in male fetuses. Mutations inactivating AMH or AMH receptor type 2 (AMHR2) are responsible for persistent Müllerian duct syndrome (PMDS) in otherwise normally virilised 46,XY males. This review is based on published cases, including 157 personal ones. PMDS can present in one of three ways: bilateral cryptorchidism, unilateral cryptorchidism with contralateral hernia and transverse testicular ectopia. Abnormalities of male excretory ducts are frequent. Testicular malignant degeneration occurs in 33% of adults with PMDS. Cancer of Müllerian derivatives is less frequent. Fertility is rare but possible if at least one testis is scrotal and its excretory ducts are intact. Up to January 2019, 81 families with 65 different mutations of the AMH gene, mostly in exons 1, 2 and 5, have been identified. AMHR2 gene mutations comprising 64 different alleles have been discovered in 79 families. The most common mutation, a 27-bp deletion in the kinase domain, was found in 30 patients of mostly Northern European origin. In 12% of cases, no mutation of AMH or AMHR2 has been detected, suggesting a disruption of other pathways involved in Müllerian regression.
Asunto(s)
Hormona Antimülleriana/genética , Trastorno del Desarrollo Sexual 46,XY/genética , Mutación , Receptores de Péptidos/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Exones , HumanosRESUMEN
Male sex differentiation is driven by 2 hormones, testosterone and anti-müllerian hormone (AMH), responsible for the regression of müllerian ducts in male fetuses. Mutations inactivating AMH or its receptor AMHRII lead to the persistent müllerian duct syndrome (PMDS) in otherwise normally virilized 46,XY males. Our objective was to review the clinical, anatomical, and molecular features of PMDS based upon a review of the literature and upon 157 personal cases. Three clinical presentations exist: bilateral cryptorchidism, unilateral cryptorchidism with contralateral hernia, and transverse testicular ectopia. Abnormalities of male excretory ducts are frequent. Testicular malignant degeneration occurs in 33% of adults with the disorder, while cancer of müllerian derivatives is less frequent. Fertility is rare but possible if at least one testis is scrotal and its excretory ducts are intact. Eighty families with 64 different mutations of the AMH gene have been identified, mostly in exons 1, 2, and 5. AMHRII gene mutations representing 58 different alleles have been discovered in 75 families. The most common mutation, a 27-bp deletion in the kinase domain, was found in 30 patients of mostly Northern European origin. In 12% of cases, no mutation of AMH or AMHRII has been detected, suggesting a disruption of other pathways involved in müllerian regression.
Asunto(s)
Trastorno del Desarrollo Sexual 46,XY/patología , Hormona Antimülleriana/química , Hormona Antimülleriana/genética , Trastorno del Desarrollo Sexual 46,XY/genética , Hormonas/metabolismo , Humanos , Patrón de Herencia/genética , Modelos Moleculares , Mutación/genéticaRESUMEN
Plasma anti-Müllerian hormone (AMH) concentrations have been recently found to be predictive of the number of embryos recovered after FSH superovulatory treatment in the cow. However, the sensitivity of the Active Müllerian-inhibiting substance/AMH ELISA (ref. 10-14400; DSL-Beckman-Coulter) used to make these measurements in bovine plasma samples is low because it was developed to measure human AMH levels. To overcome this limitation, we developed an immunoassay specific for the bovine (B), ovine (O), and caprine (C) species, the bovine-ovine-caprine (BOC) ELISA. For this purpose, we produced recombinant bovine AMH for standardization, and we used monoclonal antibodies raised against bovine AMH, previously prepared by our laboratory. We evaluated the precision, accuracy, specificity, limit of detection, and functional sensitivity of the assay. The intra-assay coefficient of variation ranged between 3.4% and 11.3% for AMH concentrations between 23.68 and 1.74 ng/mL, and the interassay coefficient of variation ranged between 4.8% and 20.5% for concentrations between 25.53 and 1.42 ng/mL, respectively. The assay displayed a good linearity, had a detection limit of 0.4 ng/mL and a functional sensitivity of 1.4 ng/mL. It also cross-reacted with ovine and caprine AMHs. Both the mean and median AMH levels measured in 40 cow plasma samples using the BOC ELISA were approximately 44 fold higher than the mean and median AMH levels measured with the Active Müllerian-inhibiting substance/AMH ELISA. Moreover, a higher correlation was observed between the average number of embryos recovered from each cow after superovulatory treatment and AMH concentrations measured with the BOC ELISA. This BOC ELISA provides a very efficient tool for evaluating the ovarian follicular reserve of cows and predicting their embryo production capacity.
Asunto(s)
Hormona Antimülleriana/sangre , Desarrollo Embrionario , Ensayo de Inmunoadsorción Enzimática/veterinaria , Animales , Bovinos , Femenino , Pruebas de Función Ovárica/métodos , Pruebas de Función Ovárica/veterinaria , Sensibilidad y EspecificidadRESUMEN
Anti-Müllerian hormone (AMH), secreted by immature Sertoli cells, provokes the regression of male fetal Müllerian ducts. FSH stimulates AMH production; during puberty, AMH is downregulated by intratesticular testosterone and meiotic germ cells. In boys, AMH determination is useful in the clinical setting. Serum AMH, which is low in infants with congenital central hypogonadism, increases with FSH treatment. AMH is also low in patients with primary hypogonadism, for instance in Down syndrome, from early postnatal life and in Klinefelter syndrome from midpuberty. In boys with nonpalpable gonads, AMH determination, without the need for a stimulation test, is useful to distinguish between bilaterally abdominal gonads and anorchism. In patients with disorders of sex development (DSD), serum AMH determination helps as a first line test to orientate the etiologic diagnosis: low AMH is indicative of dysgenetic DSD whereas normal AMH is suggestive of androgen synthesis or action defects. Finally, in patients with persistent Müllerian duct syndrome (PMDS), undetectable serum AMH drives the genetic search to mutations in the AMH gene, whereas normal or high AMH is indicative of an end organ defect due to AMH receptor gene defects.
RESUMEN
The birth of a child with ambiguous genitalia is a challenging and distressing event for the family and physician and one with life-long consequences. Most disorders of sexual differentiation (DSD) associated with ambiguous genitalia are the result either of inappropriate virilization of girls or incomplete virilization of boys. It is important to establish a diagnosis as soon as possible, for psychological, social, and medical reasons, particularly for recognizing accompanying life-threatening disorders such as the salt-losing form of congenital adrenal hyperplasia. In most instances, there is sufficient follow-up data so that making the diagnosis also establishes the appropriate gender assignment (infants with congenital adrenal hyperplasia, those with androgen resistance syndromes), but some causes of DSD such as steroid 5α-reductase 2 deficiency and 17ß-hydroxysteroid dehydrogenase deficiency are associated with frequent change in social sex later in life. In these instances, guidelines for sex assignment are less well established.
Asunto(s)
Trastornos del Desarrollo Sexual/psicología , Trastornos del Desarrollo Sexual/terapia , Adolescente , Desarrollo del Adolescente , Niño , Desarrollo Infantil , Preescolar , Diagnóstico Diferencial , Trastornos del Desarrollo Sexual/diagnóstico , Trastornos del Desarrollo Sexual/fisiopatología , Familia/psicología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Médicos/psicología , Pronóstico , Procedimientos de Reasignación de Sexo/psicologíaRESUMEN
Male fetal sexual differentiation of the genitalia is driven by Leydig cell-secreted androgens and Sertoli cell-secreted anti-Müllerian hormone (AMH). Disorders of sex development (DSD) may be due to abnormal morphogenesis of genital primordia or to defective testicular hormone secretion or action. In dysgenetic DSD, due to an early fetal-onset primary hypogonadism affecting Leydig and Sertoli cells, the fetal gonads are incapable of producing normal levels of androgens and AMH. In non-dysgenetic DSD, either Leydig cells or Sertoli cells are affected but not both. Persistent Müllerian duct syndrome (PMDS) may result from Sertoli cell-specific dysfunction due to mutations in the AMH gene; these patients have Fallopian tubes and uterus, but male external genitalia. In DSD due to insensitivity to testicular hormones, fetal Leydig and Sertoli cell function is normal. Defective androgen action is associated with female or ambiguous genitalia whereas insensitivity to AMH results in PMDS with normal serum AMH. Clinical and biological features of PMDS due to mutations in the genes coding for AMH or the AMH receptor, as well as genetic aspects and clinical management are discussed.
Asunto(s)
Hormona Antimülleriana/metabolismo , Trastornos del Desarrollo Sexual/metabolismo , Trastornos del Desarrollo Sexual/terapia , Desarrollo Fetal , Testículo/metabolismo , Animales , Hormona Antimülleriana/genética , Biomarcadores/sangre , Biomarcadores/metabolismo , Diagnóstico Diferencial , Trastornos del Desarrollo Sexual/diagnóstico , Trastornos del Desarrollo Sexual/genética , Humanos , Células Intersticiales del Testículo/metabolismo , Masculino , Mutación , Receptores de Péptidos/genética , Receptores de Péptidos/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Células de Sertoli/metabolismo , Testosterona/sangre , Testosterona/metabolismoRESUMEN
Our goal was to compare phenotype and genotype in two extended Middle-Eastern families affected by persistent Müllerian duct syndrome due to mutations of the type II anti-Müllerian hormone receptor (AMHR-II). The first, consanguineous, family consisted of 6 boys and 2 girls, the second consisted of 4 girls and 2 boys. In family I, 4 boys and 1 girl were homozygous for a stop mutation in the 9th exon of AMHR-II, removing part of the intracellular domain of the protein. In family II, 1 girl and 1 boy were homozygous for a transversion changing conserved histidine 254 into a glutamine. Both homozygous girls were normal. In the homozygous males, the degree of development of Müllerian derivatives was variable. The uterus was well developed in 2 boys of family I and in the patient from family II; however, in 1 subject from family I, Müllerian derivatives were undetectable. Taken together, the diversity of clinical symptoms within the same sibship and the lack of correlation between the development of the Müllerian derivatives and the severity of the molecular defects suggest highly variable penetrance of the abnormal alleles and/or the existence of other genetic or epigenetic modifiers of gene expression.
Asunto(s)
Hormona Antimülleriana/sangre , Trastorno del Desarrollo Sexual 46,XY/genética , Receptores de Péptidos/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Niño , Preescolar , Codón de Terminación , Consanguinidad , Criptorquidismo/patología , Femenino , Estudios de Asociación Genética , Homocigoto , Humanos , Lactante , Recién Nacido , Masculino , Modelos Moleculares , Datos de Secuencia Molecular , Alineación de Secuencia , Útero/anomalíasAsunto(s)
Hormona Antimülleriana/genética , Hormona Antimülleriana/fisiología , Femenino , Humanos , MasculinoRESUMEN
In Sertoli cells, anti-Müllerian hormone (AMH) expression is upregulated by FSH via cyclic AMP (cAMP), although no classical cAMP response elements exist in the AMH promoter. The response to cAMP involves NF-κB and AP2; however, targeted mutagenesis of their binding sites in the AMH promoter do not completely abolish the response. In this work we assessed whether SOX9, SF1, GATA4, and AP1 might represent alternative pathways involved in cAMP-mediated AMH upregulation, using real-time RT-PCR (qPCR), targeted mutagenesis, luciferase assays, and immunocytochemistry in the Sertoli cell line SMAT1. We also explored the signaling cascades potentially involved. In qPCR experiments, Amh, Sox9, Sf1, and Gata4 mRNA levels increased after SMAT1 cells were incubated with cAMP. Blocking PKA abolished the effect of cAMP on Sox9, Sf1, and Gata4 expression, inhibiting PI3K/PKB impaired the effect on Sf1 and Gata4, and reducing MEK1/2 and p38 MAPK activities curtailed Gata4 increase. SOX9 and SF1 translocated to the nucleus after incubation with cAMP. Mutations of the SOX9 or SF1 sites, but not of GAT4 or AP1 sites, precluded the response of a 3,063-bp AMH promoter to cAMP. In conclusion, in the Sertoli cell line SMAT1 cAMP upregulates SOX9, SF1, and GATA4 expression and induces SOX9 and SF1 nuclear translocation mainly through PKA, although other kinases may also participate. SOX9 and SF1 binding to the AMH promoter is essential to increase the activity of the AMH promoter in response to cAMP.
Asunto(s)
Hormona Antimülleriana/metabolismo , AMP Cíclico/metabolismo , Factor de Transcripción SOX9/metabolismo , Células de Sertoli/metabolismo , Factor Esteroidogénico 1/metabolismo , Hormona Antimülleriana/genética , Línea Celular , AMP Cíclico/genética , Proteínas de Unión al ADN , Factor de Transcripción GATA4/genética , Factor de Transcripción GATA4/metabolismo , Expresión Génica , Humanos , Masculino , Regiones Promotoras Genéticas , Factores de Empalme de ARN , Factor de Transcripción SOX9/genética , Transducción de Señal/fisiología , Factor Esteroidogénico 1/genética , Factores de Transcripción , Regulación hacia ArribaRESUMEN
Anti-Müllerian hormone (AMH), also called Müllerian-inhibiting substance, a member of the TGF-ß family, is responsible for the regression of Müllerian ducts in the male fetus. In females, AMH is synthesized by granulosa cells of preantral and small antral follicles, and production wanes at later stages of follicle maturation. Using RT-PCR in luteal granulosa cells in primary culture and reporter gene techniques in the KK1 granulosa cell line, we show that FSH and cAMP enhance AMH transcription, and LH has an additive effect. Gonadotropins and cAMP act through protein kinase A and p38 MAPK signaling pathways and involve the GATA binding factor-4 and steroidogenic factor-1 transcription factors, among others. The expression profile of AMH and the dynamics of serum AMH after gonadotropin stimulation have been interpreted as a down-regulating effect of FSH upon AMH production by granulosa cells. The specific effect of gonadotropins upon granulosa cells may be obscured in vivo by the effect of FSH upon follicular maturation and by the presence of other hormones and growth factors, acting individually or in concert.
Asunto(s)
Hormona Antimülleriana/genética , AMP Cíclico/metabolismo , Hormona Folículo Estimulante/metabolismo , Células de la Granulosa/metabolismo , Transcripción Genética , Animales , Células Cultivadas , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Femenino , Factor de Transcripción GATA4/metabolismo , Genes Reporteros , Gonadotropinas/metabolismo , Humanos , Hormona Luteinizante/metabolismo , Ratones , Folículo Ovárico/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor Esteroidogénico 1/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
TGF-ß family ligands are translated as prepropeptide precursors and are processed into mature C-terminal dimers that signal by assembling a serine/threonine kinase receptor complex containing type I and II components. Many TGF-ß ligands are secreted in a latent form that cannot bind their receptor, due to the pro-region remaining associated with the mature ligand in a noncovalent complex after proteolytic cleavage. Here we show that anti-Müllerian hormone (AMH), a TGF-ß family ligand involved in reproductive development, must be cleaved to bind its type II receptor (AMHRII), but dissociation of the pro-region from the mature C-terminal dimer is not required for this initial interaction. We provide direct evidence for this interaction by showing that the noncovalent complex binds to a soluble form of AMHRII in an ELISA format and to AMHRII immobilized on Sepharose. Binding of the noncovalent complex to Sepharose-coupled AMHRII induces dissociation of the pro-region from the mature C-terminal dimer, whereas no dissociation occurs after binding to immobilized AMH antibodies. The pro-region cannot be detected after binding of the AMH noncovalent complex to AMHRII expressed on COS cells, indicating that pro-region dissociation may occur as a natural consequence of receptor engagement on cells. Moreover, the mature C-terminal dimer is more active than the noncovalent complex in stimulating Sma- and Mad-related protein activation, suggesting that pro-region dissociation contributes to the assembly of the active receptor complex. AMH thus exemplifies a new mechanism for receptor engagement in which interaction with the type II receptor promotes pro-region dissociation to generate mature ligand.
Asunto(s)
Hormona Antimülleriana/metabolismo , Procesamiento Proteico-Postraduccional , Receptores de Péptidos/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Proteínas Smad/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Animales , Hormona Antimülleriana/química , Células COS , Chlorocebus aethiops , Humanos , Modelos Biológicos , Fosforilación , Multimerización de Proteína , Receptores Fc/metabolismo , SolubilidadRESUMEN
The anti-Müllerian hormone type II (AMHRII) receptor is the primary receptor for anti-Müllerian hormone (AMH), a protein produced by Sertoli cells and responsible for the regression of the Müllerian duct in males. AMHRII is a membrane protein containing an N-terminal extracellular domain (ECD) that binds AMH, a transmembrane domain, and an intracellular domain with serine/threonine kinase activity. Mutations in the AMHRII gene lead to persistent Müllerian duct syndrome in human males. In this paper, we have investigated the effects of 10 AMHRII mutations, namely 4 mutations in the ECD and 6 in the intracellular domain. Molecular models of the extra- and intracellular domains are presented and provide insight into how the structure and function of eight of the mutant receptors, which are still expressed at the cell surface, are affected by their mutations. Interestingly, two soluble receptors truncated upstream of the transmembrane domain are not secreted, unless the transforming growth factor beta type II receptor signal sequence is substituted for the endogenous one. This shows that the AMHRII signal sequence is defective and suggests that AMHRII uses its transmembrane domain instead of its signal sequence to translocate to the endoplasmic reticulum, a characteristic of type III membrane proteins.
Asunto(s)
Hormona Antimülleriana/metabolismo , Trastornos del Desarrollo Sexual/genética , Mutación , Receptores de Péptidos/genética , Receptores de Péptidos/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Transducción de Señal , Secuencia de Aminoácidos , Animales , Células COS , Línea Celular , Chlorocebus aethiops , Trastornos del Desarrollo Sexual/metabolismo , Humanos , Ligandos , Ratones , Datos de Secuencia Molecular , Unión Proteica , Estructura Terciaria de Proteína , Transporte de Proteínas , Receptores de Péptidos/química , Receptores de Factores de Crecimiento Transformadores beta/química , Alineación de SecuenciaRESUMEN
Anti-Müllerian hormone (AMH), also called MUllerian inhibiting substance (MIS) is a product of supporting gonadal Sertoli and granulosa cells. Its main physiological role is the induction of regression of Müllerian ducts in male fetuses but it also plays a role in Leydig cell steroidogenesis and in follicular development. It is a member of the transforming growth factor B family and signals through two serine/threonine kinase receptors, only one of whom, type II, is specific. Type I receptors and the intracytoplasmic signaling molecules are shared with the bone morphogenetic family. AMH is positively regulated by SF1, SOX9 and FSH. Testosterone is a powerful downregulator. Males lacking functional AMH or AMH receptor genes do not undergo regression of MUllerian derivatives during fetal life. AMH is an excellent marker of prepubertal testicular function and has gained recognition as a valuable marker of follicular reserve in adult women.
Asunto(s)
Glicoproteínas/genética , Glicoproteínas/fisiología , Trastornos Gonadales/diagnóstico , Hormonas Testiculares/genética , Hormonas Testiculares/fisiología , Testículo/embriología , Testículo/fisiología , Animales , Hormona Antimülleriana , Biomarcadores , Niño , Femenino , Trastornos Gonadales/genética , Trastornos Gonadales/fisiopatología , Humanos , Masculino , Diferenciación Sexual/genéticaRESUMEN
PURPOSE: To improve treatment policy, we retrospectively evaluated the results of early corrective genital surgery in 63 sexually ambiguous patients 14 to 38 years old. MATERIALS AND METHODS: We analyzed all records classified under male pseudohermaphroditism and true hermaphroditism. Anatomical and functional results and data on self-reported satisfaction were recorded by the managing physician at the last routine followup visit. RESULTS: A total of 38 patients were raised female and 25 were raised male. Basal procedures for external genital reconstruction were initiated shortly after birth, when gender was assigned. Complementary surgical procedures were usually required later. In both sexes there was a significant negative correlation between the number of basal, but not complementary, procedures required and year of birth, due to the adoption of 1-stage procedures in the early 1980s. Most patients with gonadal dysgenesis were raised as females and menstruated under treatment but breast development was abnormal in 30%. Spontaneous puberty was observed in true hermaphrodites raised as either sex. In females with partial androgen insensitivity the main problem was shortness of the vagina. Amenorrhea and infertility often led to transient distress. In males results were poor due to intractable micropenis and minimal virilization. Results were good in 5alpha-reductase deficiency. CONCLUSIONS: Results of intersex surgery have clearly improved with time, and apart from a patient with 5alpha-reductase deficiency who underwent a successful sex change, no patient expressed dissatisfaction with sex of rearing. However, in the absence of an in-depth psychological survey, these optimistic conclusions are valid only in the settings of our study.