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1.
Int J Mol Sci ; 22(7)2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33915887

RESUMEN

The methylation of adenosine in the N6 position (m6A) is a widely used modification of eukaryotic mRNAs. Its importance for the regulation of mRNA translation was put forward recently, essentially due to the ability of methylated mRNA to be translated in conditions of inhibited cap-dependent translation initiation, e.g., under stress. However, the peculiarities of translation initiation on m6A-modified mRNAs are not fully known. In this study, we used toeprinting and translation in a cell-free system to confirm that m6A-modified mRNAs can be translated in conditions of suppressed cap-dependent translation. We show for the first time that m6A-modified mRNAs display not only decreased elongation, but also a lower efficiency of translation initiation. Additionally, we report relative resistance of m6A-mRNA translation initiation in the absence of ATP and inhibited eIF4A activity. Our novel findings indicate that the scanning of m6A-modified leader sequences is performed by a noncanonical mechanism.


Asunto(s)
Biosíntesis de Proteínas , ARN Mensajero/metabolismo , Células HEK293 , Humanos , Metilación
2.
Endocr Res ; 45(1): 32-40, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31394950

RESUMEN

Purpose: Testotoxicosis is an autosomal dominant form of limited gonadotropin-independent precocious puberty in boys. It is caused by a heterozygous constitutively activating mutation of the LHCGR gene encoding the luteinizing/hormone receptor (LHR). Some twenty mutations of the LHCGR gene have been reported. Most of them are constitutive mutations isolated from blood leukocyte DNA, although others are somatic, found only in testicular tumoural tissue. In all the previously reported cases of these somatic mutations, the tumour, whether a nodular Leydig cell adenoma or hyperplasia, was easily visible on testicular ultrasonography. The aim of this study was to describe an unusual presentation of a patient with the clinical and hormonal characteristics of testotoxicosis but no well-circumscribed lesion at testicular ultrasonography.Materials and Methods: Molecular analysis of the LHCGR gene was performed by direct sequencing of DNA extracted from peripheral leucocytes and testicular biopsy.Results: Molecular analysis didn't find any LHR mutation in blood, whereas it revealed for the first time a somatic D578H mutation in testicular tissue despite no evidence of a nodular aspect at testis ultrasonography.Conclusions: This observation underlines the need to look for a somatic LHCGR gene mutation from the testicular biopsies of all boys with testotoxicosis with no constitutive LHCGR gene mutation identified from blood DNA, even in the absence of circumscribed testicular lesion at ultrasonography. In addition, based on the known link between LHR mutations and testicular tumourigenesis, yearly ultrasound monitoring of the testes should be considered for these patients.


Asunto(s)
Pubertad Precoz/diagnóstico por imagen , Pubertad Precoz/genética , Receptores de HL/genética , Niño , Humanos , Masculino , Ultrasonografía
3.
Clin Genet ; 92(1): 99-103, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28032338

RESUMEN

Steroidogenic factor 1 (encoded by SF1/NR5A1) is a transcription factor with multiple target genes involved in the development and function of multiple steroidogenic and non-steroidogenic tissues. NR5A1 mutations lead to several phenotypes, including sex reversal, spermatogenesis failure, premature ovarian failure and adrenocortical insufficiency. The implication of NR5A1 mutations in spleen development anomalies was recently highlighted. We provide new evidence of this involvement, describing a novel heterozygous non-sense NR5A1 mutation in a 46,XY-DSD with polysplenia female proband and her father, who had hypospadias and asplenia.


Asunto(s)
Insuficiencia Suprarrenal/genética , Hipospadias/genética , Insuficiencia Ovárica Primaria/genética , Factor Esteroidogénico 1/genética , Adolescente , Insuficiencia Suprarrenal/patología , Niño , Femenino , Heterocigoto , Humanos , Hipospadias/patología , Masculino , Mutación , Insuficiencia Ovárica Primaria/patología , Procesos de Determinación del Sexo/genética , Espermatogénesis/genética , Bazo/crecimiento & desarrollo , Bazo/patología
4.
Osteoporos Int ; 27(1): 135-46, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26245848

RESUMEN

UNLABELLED: Low bone mass is a consequence of anorexia nervosa (AN). This study assessed the effects of energy deficiency on various bone and hormonal parameters. The interrelationships between energy deficiency and bone remodelling, glucose homeostasis and adipokines underscore the importance of preventing energy deficiency to limit demineralisation and hormonal alterations in AN patients. INTRODUCTION: Low areal bone mineral density (aBMD) is a well-known consequence of AN. However, the impact of reduced energy expenditure on bone metabolism is unknown. This study assessed the effects of energy deficiency on bone remodelling and its potential interactions with glucose homeostasis and adipose tissue-derived hormones in AN, a clinical model for reduced energy expenditure. METHODS: Fifty women with AN and 50 age-matched controls (mean age 18.1 ± 2.7 and 18.0 ± 2.1 years, respectively) were enrolled. aBMD was determined with DXA. Resting energy expenditure (REEm), a marker of energy status, was indirectly assessed by calorimetry. Bone turnover markers, undercarboxylated osteocalcin (ucOC), parameters of glucose homeostasis, adipokines and growth factors were concomitantly evaluated. RESULTS: AN patients presented low aBMD at all bone sites. REEm, bone formation markers, ucOC, glucose, insulin, HOMA-IR, leptin and IGF-1 were significantly reduced, whereas the bone resorption marker, leptin receptor (sOB-R) and adiponectin were elevated in AN compared with CON. In AN patients, REEm was positively correlated with weight, BMI, whole body (WB) fat mass, WB fat-free soft tissue, markers of bone formation, glucose, insulin, HOMA-IR, leptin and IGF-1 and negatively correlated with the bone resorption marker and sOB-R. Biological parameters, aBMD excepted, appeared more affected by the weight variation in the last 6 months than by the disease duration. CONCLUSIONS: The strong interrelationships between REEm and bone remodelling, glucose homeostasis and adipokines underscore the importance of preventing energy deficiency to limit short- and long-term bone demineralisation and hormonal alterations in AN patients.


Asunto(s)
Adipoquinas/sangre , Anorexia Nerviosa/fisiopatología , Glucemia/metabolismo , Remodelación Ósea/fisiología , Metabolismo Energético/fisiología , Adolescente , Anorexia Nerviosa/sangre , Anorexia Nerviosa/complicaciones , Antropometría/métodos , Biomarcadores/sangre , Peso Corporal/fisiología , Densidad Ósea/fisiología , Enfermedades Óseas Metabólicas/sangre , Enfermedades Óseas Metabólicas/etiología , Enfermedades Óseas Metabólicas/fisiopatología , Estudios de Casos y Controles , Femenino , Homeostasis/fisiología , Humanos , Péptidos y Proteínas de Señalización Intercelular/sangre , Menstruación/fisiología , Factores de Tiempo , Adulto Joven
5.
Horm Metab Res ; 48(3): 174-7, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26418163

RESUMEN

Recent experimental data suggest that circulating serotonin interacts with bone metabolism, although this is less clear in humans. This study investigated whether serum serotonin interferes with bone metabolism in young women with anorexia nervosa (AN), a clinical model of energy deprivation. Serum serotonin, markers of bone turnover [osteocalcin (OC), procollagen type I N-terminal propeptide (PINP), type I-C telopeptide breakdown products (CTX)], leptin, soluble leptin receptor (sOB-R), and insulin-like growth factor-1 (IGF-1) and its binding protein (IGFBP-3) were assessed. Whole body, spine, hip, and radius areal bone mineral density BMD (aBMD) were assessed by dual-energy X-ray absorptiometry in 21 patients with AN and 19 age-matched controls. Serum serotonin, leptin, IGF-1, IGFBP-3, OC, PINP, and aBMD at all sites, radius excepted, were significantly reduced in AN whereas CTX and sOB-R were increased compared with controls. Serum serotonin levels were positively correlated with weight, body mass index, whole body fat mass, leptin, and IGF-1, and negatively with CTX for the entire population. Low serum serotonin levels are observed in patients with AN. Although no direct link between low serum serotonin levels and bone mass was identified in these patients, the negative relationship between serotonin and markers of bone resorption found in all population nevertheless suggests the implication of serotonin in bone metabolism. Impact of low serum serotonin on bone in AN warrants further studies.


Asunto(s)
Anorexia Nerviosa/sangre , Resorción Ósea/sangre , Serotonina/sangre , Adolescente , Anorexia Nerviosa/complicaciones , Anorexia Nerviosa/fisiopatología , Antropometría , Densidad Ósea , Resorción Ósea/complicaciones , Resorción Ósea/fisiopatología , Estudios de Casos y Controles , Femenino , Hormonas , Humanos
7.
Andrologia ; 46(6): 703-6, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23808476

RESUMEN

We report on a case of a man with familial, X-linked, partial androgen insensitivity, in whom a new point mutation in the androgen receptor (AR) ligand-binding domain (causing a valine-to-alanine substitution at codon 686) was identified. High-dose prolonged testosterone therapy resulted in marked progression in patient's appearance and great improvement in sperm count and characteristics. In combination with intracytoplasmic microinjection, treatment resulted in fertility. This is believed to be the first report of such a case. This case supports high-dose testosterone therapeutic trial in this condition. Furthermore, it underscores the possibility of achieving fertility with current endocrine and assisted reproduction modalities, making some of these X-linked AR mutations paternally transmissible.


Asunto(s)
Síndrome de Resistencia Androgénica/tratamiento farmacológico , Síndrome de Resistencia Androgénica/genética , Mutación Puntual , Receptores Androgénicos/genética , Testosterona/uso terapéutico , Adulto , Sustitución de Aminoácidos , Síndrome de Resistencia Androgénica/patología , Femenino , Humanos , Recién Nacido , Infertilidad Masculina/genética , Infertilidad Masculina/patología , Infertilidad Masculina/terapia , Masculino , Embarazo , Análisis de Semen , Recuento de Espermatozoides , Inyecciones de Esperma Intracitoplasmáticas , Testosterona/administración & dosificación
8.
Biochem Pharmacol ; 217: 115858, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37863325

RESUMEN

The CD40 receptor and its ligand CD154 are widely expressed in various immune-competent cells. Interaction of CD154 with CD40 is essential for B-cell growth, differentiation, and immunoglobulin class switching. Many other immune-competent cells involved in innate and adaptive immunity communicate through this co-stimulatory ligand-receptor dyad. CD40-CD154 interaction is involved in the pathogenesis of numerous inflammatory and autoimmune diseases. While CD40 and CD154 are membrane-bound proteins, their soluble counterparts are generated by proteolytic cleavage or alternative splicing. This review summarises current knowledge about the impact of single nucleotide polymorphisms in the human CD40 gene and compensatory changes in the plasma level of the soluble CD40 receptor (sCD40) isoform in related pro-inflammatory diseases. It discusses regulation patterns of the disintegrin metalloprotease ADAM17 function leading to ectodomain shedding of transmembrane proteins, such as pro-inflammatory adhesion molecules or CD40. The role of sCD40 as a potential biomarker for chronic inflammatory diseases will also be discussed.


Asunto(s)
Antígenos CD40 , Ligando de CD40 , Humanos , Ligandos , Antígenos CD40/genética , Antígenos CD40/metabolismo , Ligando de CD40/genética , Ligando de CD40/metabolismo , Enfermedad Crónica , Proteínas de la Membrana
9.
Endocr Connect ; 12(12)2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37855374

RESUMEN

Although hyperandrogenism is a frequent cause of consultation in adolescent girls, more severe forms with virilization must lead to suspicion of an adrenal or ovarian tumor. However, they may also reveal a 46,XY disorder of sexual development (DSD). Here, we describe four adolescent girls referred for pubertal virilization and in whom we diagnosed a 46,XY DSD. We performed gene mutation screening by Sanger sequencing (all patients) and by next-generation sequencing (NGS) in patient #4. We identified new heterozygous NR5A1 gene variants in patients #1 and #2 and a homozygous SRD5A2 gene deletion in patient #3. Patient #4 received a diagnosis of complete androgen insensitivity in childhood; however, due the unusual pubertal virilization, we completed the gene analysis by NGS that revealed two heterozygous HSD17B3 variants. This work underlines the importance of considering the hypothesis of 46,XY DSD in adolescent girls with unexplained virilization at puberty.

10.
Int J Androl ; 35(3): 253-64, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22372605

RESUMEN

Exposure to endocrine-disrupting chemicals (EDCs) has been suggested to contribute to the increasing trends of external genital malformation in male newborns. In Northeastern Brazil, the poor sanitary conditions found in the favelas encourage the widespread use of pesticides. This 2-year study of a total birth cohort of full-term male newborns in the regional hospitals of Campina Grande (Paraíba, Brazil) sought to (1) accurately establish for the first time the incidences of neonatal male genital malformations, (2) investigate the endocrine and genetic aetiologies of these malformations, and (3) evaluate their associations with possible prenatal exposure to EDCs. A total of 2710 male newborns were explored for cryptorchidism, hypospadias and micropenis. Cases were referred to the Pediatric Endocrine Clinic for endocrine and genetic investigations, and all parents were interviewed about their environmental/occupational exposure to EDCs before/during pregnancy by paediatric endocrinologists using a detailed questionnaire. We observed 56 cases of genital malformation (2.07%), including 23 cryptorchidism (0.85%), 15 hypospadias (0.55%), and 18 micropenis (0.66%). All cases exhibited normal/subnormal testosterone production and none presented androgen receptor or 5α-reductase gene mutation. More than 92% of these newborns presented foetal contamination by EDCs, as their mothers reported daily domestic use of pesticides (i.e., DDT) and other EDCs. Most of these undervirilized male newborns presented additional EDC contamination, as 80.36% of the mothers and 58.63% of the fathers reported paid or unpaid work that entailed the use of pesticides and other EDCs before/during pregnancy for the mothers and around the time of fertilization for the fathers. The high rate of micropenis in our population associated with an elevated percentage of parental environmental/occupational exposure to EDCs before/during pregnancy indicates that foetal contamination may be a risk factor for the development of male external genital malformation.


Asunto(s)
Disruptores Endocrinos/toxicidad , Exposición a Riesgos Ambientales/efectos adversos , Enfermedades de los Genitales Masculinos/epidemiología , Plaguicidas/toxicidad , Brasil/epidemiología , Criptorquidismo/epidemiología , Femenino , Humanos , Hipospadias/epidemiología , Lactante , Recién Nacido , Masculino , Exposición Materna/efectos adversos , Exposición Paterna/efectos adversos , Pene/anomalías , Embarazo , Prevalencia
11.
Gynecol Obstet Fertil Senol ; 50(5): 402-408, 2022 05.
Artículo en Francés | MEDLINE | ID: mdl-34560302

RESUMEN

Endocrine disruptor chemicals (EDCs) are ubiquitous contaminants in the environment, wildlife, and humans. During the last 20 years, several epidemiological, clinical and experimental studies have demonstrated the role of EDCs on the reduction of male and female fertility. The concept of foetal origins of adult disease is particularly topical in the field of reproduction. Moreover, exposure to EDCs during pregnancy has been shown to influence epigenetic programming of endocrine signalling and other important physiological pathways, and provided the basis for multi- and transgenerational transmission of adult diseases. However, the large panel of EDCs simultaneously present in the air, sol and water makes the quantification of human exposition still a challenge. Gas chromatography coupled with mass spectrometry, the measurement of total plasmatic hormonal bioactivity on stably transfected cell lines as well as the EDC analysis in hair samples are useful methods of evaluation. More recently, microRNAs analysis offers a new perspective in the comprehension of the mechanisms behind the modulation of cellular response to foetal or post-natal exposure to EDCs. They will help researchers and clinicians in identifying EDCs exposition markers and new therapeutic approaches in the future.


Asunto(s)
Disruptores Endocrinos , Adulto , Disruptores Endocrinos/efectos adversos , Disruptores Endocrinos/análisis , Femenino , Fertilidad , Humanos , Masculino , Embarazo , Reproducción
12.
Biochem Biophys Res Commun ; 404(1): 250-3, 2011 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-21114960

RESUMEN

The 5'-untranslated sequence of tobacco mosaic virus RNA--the so called omega leader--is a well-known translational enhancer. The structure of the omega RNA has unusual features. Despite the absence of extensive secondary structure of the Watson-Crick type, the omega RNA possesses a stable compact conformation. The central part of the omega sequence contains many CAA repeats and is flanked by U-rich regions. In this work we synthesized the polyribonucleotides containing modified omega sequences, and studied them using analytical ultracentrifugation and thermal melting techniques. It was demonstrated that changes made in both the central and the 3'-proximal part of the sequence led to a strong destabilization of the omega RNA structure. We conclude that the regular (CAA)(n) core region and the 3'-proximal AU-rich region of the omega RNA interact with each other and contribute together to the formation of a stable tertiary structure.


Asunto(s)
Regiones no Traducidas 5' , Conformación de Ácido Nucleico , ARN Viral/química , Virus del Mosaico del Tabaco/genética , Virus del Mosaico del Tabaco/metabolismo , Secuencia de Bases , Datos de Secuencia Molecular
13.
Osteoporos Int ; 22(12): 3055-66, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21359671

RESUMEN

UNLABELLED: Peripubertal artistic gymnasts display elevated areal bone mineral density at various bone sites, despite delayed menarche and a high frequency of menstrual disorders, factors that may compromise bone health. The concomitant improvement in femoral bone geometry and strength suggested that this type of physical activity might have favourable clinical impact. INTRODUCTION: The purpose of this study is to evaluate the effect of artistic gymnastics (GYM) on areal bone mineral density (aBMD), femoral bone geometry and bone markers and its relationship with the osteoprotegerin (OPG)/rank-ligand (RANKL) system in peripubertal girls. METHODS: Forty-six girls (age 10-17.2 years) were recruited for this study: 23 elite athletes in the GYM group (training 12-30 h/week, age at start of training 5.3 years) and 23 age-matched (± 6 months; leisure physical activity ≤ 3 h/week) controls (CON). The aBMD at whole body, total proximal femur, lumbar spine, mid-radius and skull was determined using dual-X-ray absorptiometry. Hip structural analysis (HSA software) was applied at the femur to evaluate cross-sectional area (CSA, cm(2)), cross-sectional moment of inertia (CSMI, cm(4)), and the section modulus (Z, cm(3)) and buckling ratio at neck, intertrochanteric region and shaft. Markers of bone turnover and OPG/RANKL levels were also analysed. RESULTS: GYM had higher (5.5-16.4%) non-adjusted aBMD and adjusted aBMD for age, fat-free soft tissue and fat mass at all bone sites, skull excepted and the difference increased with age. In the three femoral regions adjusted for body weight and height, CSA (12.5-18%), CSMI (14-18%), Z (15.5-18.6%) and mean cortical thickness (13.6-21%) were higher in GYM than CON, while the buckling ratio (21-27.1%) was lower. Bone markers decreased with age in both groups and GYM presented higher values than CON only in the postmenarchal period. A similar increase in RANKL with age without OPG variation was observed for both groups. CONCLUSION: GYM is associated not only with an increase in aBMD but also an improvement in bone geometry associated with an increase in bone remodelling. These adaptations seem to be independent of the OPG/RANKL system.


Asunto(s)
Densidad Ósea/fisiología , Fémur/anatomía & histología , Gimnasia/fisiología , Osteoprotegerina/metabolismo , Ligando RANK/metabolismo , Absorciometría de Fotón , Adolescente , Remodelación Ósea/fisiología , Niño , Estudios Transversales , Femenino , Fémur/diagnóstico por imagen , Humanos , Vértebras Lumbares/diagnóstico por imagen , Osteoprotegerina/sangre , Ligando RANK/sangre , Radio (Anatomía)/diagnóstico por imagen
14.
Int J Androl ; 34(6 Pt 2): e518-25, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21535007

RESUMEN

Micropenis is defined as a stretched penile length of less than 2-2.5SD for age. Aetiologies include hypogonadotropic hypogonadism, testicular dysgenesis, defects in testosterone synthesis, androgen resistance [5α-reductase (5αR) deficiency or partial androgen insensitivity] and other rare causes like growth hormone GH deficiency. Often, the cause remains unknown. The aim of this study was to determine whether isolated micropenis with normal plasma testosterone could hide a molecular defect in the androgen pathway. Twenty-six boys with isolated micropenis were included in this study. All of them had 46,XY karyotype, normal luteinizing hormone and follicle-stimulating hormone and a normal plasma testosterone response to human chorionic gonadotropin testing. Androgen receptor (AR), 5αR and steroidogenic factor 1 (SF1) genes were sequenced. A mutation in the AR gene was found in two patients, and a new mutation in the SF1 gene was found in one patient who was the only one to have a low level of inhibin B (InhB). This is the first report of isolated micropenis as a revealing symptom of AR and SF1 mutations. Anti-Mullerian hormone and InhB should thus be evaluated in patients with isolated micropenis, even when plasma testosterone is in the normal range. Detection of gene mutations is helpful for diagnosis, treatment and genetic counselling for probands.


Asunto(s)
Enfermedades de los Genitales Masculinos/genética , Secuencia de Aminoácidos , Niño , Preescolar , Hormona Folículo Estimulante/sangre , Humanos , Cariotipificación , Hormona Luteinizante/sangre , Masculino , Datos de Secuencia Molecular , Mutación , Pene/anomalías , Homología de Secuencia de Aminoácido , Factor Esteroidogénico 1/química , Factor Esteroidogénico 1/genética , Testosterona/sangre
15.
J Sports Med Phys Fitness ; 51(1): 160-8, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21297576

RESUMEN

AIM: Investigated the relationship between leptin levels or bone remodelling and physical fitness level in healthy elderly participants. METHODS: Twenty women and 18 men (mean age 72.7 years, range 59-90) performed a maximal incremental exercise test to evaluate their maximal oxygen uptake (VOmax). Basal blood concentrations of bone biochemical markers (BM) and leptin were analysed. RESULTS: Women presented higher values of leptin than men (+34.7%, P=0.024), but no difference related to gender was observed for the other biological parameters. Leptin levels were positively correlated with Body Mass Index (BMI) in both genders. Whether adjusted or not for BMI, leptin was negatively correlated with VOmax only in men (r=-0.55, P=0.02 and r=-0.57, P=0.01, respectively). No relationship between VOmax or leptin and BM was observed, except for leptin and osteocalcin in men (r=-0.66, P=0.015). CONCLUSION: Our data suggest that neither physical fitness nor leptin level seems to have a noticeable effect in the regulation of bone cell activity in healthy elderly participants. In this specific population, physical fitness plays a crucial role on leptin secretion, independently of BMI variation, and this action appears to be sex-dependent.


Asunto(s)
Remodelación Ósea/fisiología , Huesos/metabolismo , Leptina/sangre , Aptitud Física/fisiología , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteocalcina/sangre , Consumo de Oxígeno/fisiología , Factores Sexuales
16.
Int J Androl ; 33(6): 841-7, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20132346

RESUMEN

The observation of ambiguous genitalia in the newborn signals a medical, surgical and psychological emergency. The most crucial decision will be the choice of sex assignment. Rapid and precise diagnosis is thus essential. In XY newborns with normal/high plasma testosterone (T), partial androgen insensitivity syndrome (PAIS) is usually the first diagnosis evoked, which implies an androgen receptor (AR) defect. The diagnosis of steroid-5-alpha-reductase deficiency is rarely considered by the paediatrician. We report three new SRD5A2 gene mutations in four newborns from France, Morocco and Turkey. The newborns presented with ambiguous genitalia and normal plasma T values and the initial diagnosis\PAIS. In all four cases, normal sequences of the complete AR gene excluded this diagnosis and raised the hypothesis of 5α-reductase deficiency. The entire coding region (5 exons) of the SRD5A2 gene was assessed by PCR and direct sequencing analysis. For patient 1, we identified a new homozygous 2bp deletion in exon 1 (c.122_123delAG). Patient 2 had a known homozygous mutation, p.G115D, in exon 2. New compound heterozygous mutations in exon 4 (p.A215V) and exon 5 (p.X255Q) were found in patient 3. Patient 4 presented a new substitution in exon 1 (p.S14R) associated with a known polymorphism (p.V89L). Our data confirm our previous experience and clearly demonstrate that a 5-α reductase defect should be considered in all XY newborns with ambiguous genitalia and normal plasma T secretion, whatever their geographic area or ethnic group; moreover, this defect was not linked to specific phenotype. Early molecular diagnosis is indispensable for the crucial decision of the newborn's sex of rearing.


Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/deficiencia , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Trastornos del Desarrollo Sexual/diagnóstico , Secuencia de Aminoácidos , Síndrome de Resistencia Androgénica/diagnóstico , Diagnóstico Diferencial , Trastornos del Desarrollo Sexual/etnología , Trastornos del Desarrollo Sexual/genética , Humanos , Recién Nacido , Masculino , Datos de Secuencia Molecular , Mutación , Receptores Androgénicos/genética , Alineación de Secuencia
17.
J Endocrinol Invest ; 33(11): 810-4, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20511729

RESUMEN

BACKGROUND: 5α steroid reductase deficiency (5αSRD) is an autosomal recessive enzymatic deficiency and mutations in the 5α steroid reductase type 2 gene (SRD5A2) result in male pseudohermaphrodism caused by decreased dihydrotestosterone (DHT) synthesis. AIM: To identify the specific mutations of the SRD5A2 gene in Cypriot patients with 5αSRD. SUBJECTS AND METHODS: Five unrelated patients with 46,XY karyotype were examined. Four of them were born with ambiguous genitalia and 1 patient, who was raised as girl, presented with primary amenorrhea. The hCG test was informative (elevated testosterone/DHT) of 5αSRD in 3 out of 4 subjects. Sequencing of the SRD5A2 gene was completed for all patients. Genomic DNA was also isolated from a total of 204 healthy unrelated Cypriot subjects. Screening for the IVS1-2A>G mutation was performed by using direct sequencing and restriction enzyme analysis. RESULTS: The IVS1-2A>G was identified in homozygosity in 3 patients and in a compound heterozygote state in the other 2 patients, in combination with p.P181L and p.R171S in exon 3, respectively. The carrier frequency in the Cypriot population for the IVS1-2A>G mutation was estimated to be 0.98% or 2 in 204. CONCLUSIONS: The same IVS1-2A>G mutation in the SRD5A2 gene seems to characterize all Cypriot patients with 5αSRD diagnosed so far. Furthermore this relatively rare genetic defect, which has only been reported previously in a single case in the Eastern Mediterranean region, is very likely to be the result of a founder effect.


Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/deficiencia , Proteínas de la Membrana/genética , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Adolescente , Adulto , Secuencia de Bases , Preescolar , Gonadotropina Coriónica , Chipre , Trastornos del Desarrollo Sexual/genética , Femenino , Efecto Fundador , Humanos , Lactante , Recién Nacido , Masculino , Mutación
18.
J Med Genet ; 46(7): 455-7, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19429596

RESUMEN

BACKGROUND: FOXL2 encodes a forkhead transcription factor whose mutations are responsible for the blepharophimosis-ptosis-epicanthus inversus syndrome (BPES), involving craniofacial/palpebral abnormalities often associated with premature ovarian failure (POF). RESULTS: We describe a FOXL2 variant (p.Gly187Asp) in a case of POF without BPES. The subcellular localisation of FOXL2-G187D was normal but its transactivation capacity tested on two reporter promoters, one of which should be relevant to the ovary, was significantly lower than that of normal FOXL2. However, FOXL2-G187D was able to activate strongly a reporter construct driven by the promoter of Osr2 (odd-skipped related 2 transcription factor), which we have suggested to be a crucial target of FOXL2 in the craniofacial region. This is compatible with the absence of BPES in our patient. CONCLUSIONS: Our data provide evidence in favour of the implication of FOXL2 variants in non-syndromic POF and confirm the regulatory interaction between FOXL2 and OSR2 whose perturbation might contribute to the palpebral abnormalities observed in BPES patients.


Asunto(s)
Factores de Transcripción Forkhead/genética , Regulación de la Expresión Génica , Insuficiencia Ovárica Primaria/genética , Factores de Transcripción/genética , Adulto , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Femenino , Proteína Forkhead Box L2 , Humanos , Datos de Secuencia Molecular , Mutación , Regiones Promotoras Genéticas , Alineación de Secuencia
19.
J Cell Biol ; 129(3): 831-42, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7537275

RESUMEN

Thrombin-induced accumulation of phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) but not of PtdIns(3,4,5,)P3 is strongly correlated with the relocation to the cytoskeleton of 29% of the p85 alpha regulatory subunit of phosphoinositide 3-kinase (PtdIns 3-kinase) and is accompanied by a significant increase in PtdIns 3-kinase activity in this subcellular fraction. Actually, PtdIns(3,4)P2 accumulation and PtdIns 3-kinase, pp60c-src, and p125FAK translocations as well as aggregation were concomitant events occurring with a distinct lag after actin polymerization. The accumulation of PtdIns(3,4)P2 and the relocalization of PtdIns 3-kinase to the cytoskeleton were both dependent on tyrosine phosphorylation, integrin signaling, and aggregation. Furthermore, although p85 alpha was detected in anti-phosphotyrosine immunoprecipitates obtained from the cytoskeleton of thrombin-activated platelets, we failed to demonstrate tyrosine phosphorylation of cytoskeletal p85 alpha. Tyrphostin treatment clearly reduced its presence in this subcellular fraction, suggesting a physical interaction of p85 alpha with a phosphotyrosyl protein. These data led us to investigate the proteins that are able to interact with PtdIns 3-kinase in the cytoskeleton. We found an association of this enzyme with actin filaments: this interaction was spontaneously restored after one cycle of actin depolymerization-repolymerization in vitro. This association with F-actin appeared to be at least partly indirect, since we demonstrated a thrombin-dependent interaction of p85 alpha with a proline-rich sequence of the tyrosine-phosphorylated cytoskeletal focal adhesion kinase, p125FAK. In addition, we show that PtdIns 3-kinase is significantly activated by the p125FAK proline-rich sequence binding to the src homology 3 domain of p85 alpha subunit. This interaction may represent a new mechanism for PtdIns 3-kinase activation at very specific areas of the cell and indicates that the focal contact-like areas linked to the actin filaments play a critical role in signaling events that occur upon ligand engagement of alpha IIb/beta 3 integrin and platelet aggregation evoked by thrombin.


Asunto(s)
Proteínas Aviares , Compartimento Celular , Proteínas del Citoesqueleto/metabolismo , Citoesqueleto/fisiología , Activación Plaquetaria/fisiología , Transducción de Señal/fisiología , Citoesqueleto de Actina/fisiología , Actinas/metabolismo , Transporte Biológico , Plaquetas/efectos de los fármacos , Plaquetas/enzimología , Moléculas de Adhesión Celular/metabolismo , Activación Enzimática , Quinasa 1 de Adhesión Focal , Proteína-Tirosina Quinasas de Adhesión Focal , Humanos , Integrinas/metabolismo , Complejos Multienzimáticos/metabolismo , Fosfatidilinositol 3-Quinasas , Fosforilación , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas pp60(c-src)/metabolismo , Trombina/farmacología , Tirosina/metabolismo
20.
Gynecol Obstet Fertil ; 37(1): 33-44, 2009 Jan.
Artículo en Francés | MEDLINE | ID: mdl-19119048

RESUMEN

Ovarian sex cord-stromal tumors are rare tumors that originate from the nongerminal cells of ovary. Two decades ago, the identification of juvenile granulosa-cell tumors (GCT), as a specific entity inside this group, allowed a better treatment of these tumors in children. However, little data have been reported on the natural course of the disease and reliable prognostic factors have not been yet defined. We here review the clinical and genetics aspects of granulosa tumors, based on a series of 40 children. This national collaborative study involved the French Society of Children Cancer and eight clinical departments of pediatric endocrinology. We found that early diagnosis of a tumor, revealed by clinical signs of hyperoestrogeny, is an important prognostic factor. The pathophysiology of these tumors is still debatable and several cellular- and molecular-abnormal signals could be implicated in their development. The role of growth factors and oncogenes through the signaling pathway of MAP kinase is still discussed. According to our data, FSH signaling-transduction pathway, such as a constitutionally activated Galphas, could also be implicated in the induction of granulosa cell proliferation and seems to modulate the invasiveness of the tumor. Last, we have described a low-expression pattern or an extinction of an ovarian-determination gene, FOXL2, which is related to a worse prognosis of this tumor.


Asunto(s)
Factores de Transcripción Forkhead/análisis , Tumor de Células de la Granulosa/patología , Células de la Granulosa/patología , Neoplasias Ováricas/patología , Adolescente , Factores de Edad , Niño , Preescolar , Femenino , Proteína Forkhead Box L2 , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/fisiología , Tumor de Células de la Granulosa/fisiopatología , Tumor de Células de la Granulosa/cirugía , Tumor de Células de la Granulosa/terapia , Células de la Granulosa/metabolismo , Humanos , Neoplasias Ováricas/fisiopatología , Neoplasias Ováricas/cirugía , Neoplasias Ováricas/terapia , Pronóstico
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