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1.
Diabetologia ; 62(3): 408-417, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30483858

RESUMEN

AIMS/HYPOTHESIS: Against a background of a near-universally increasing incidence of childhood type 1 diabetes, recent reports from some countries suggest a slowing in this increase. Occasional reports also describe cyclical variations in incidence, with periodicities of between 4 and 6 years. METHODS: Age/sex-standardised incidence rates for the 0- to 14-year-old age group are reported for 26 European centres (representing 22 countries) that have registered newly diagnosed individuals in geographically defined regions for up to 25 years during the period 1989-2013. Poisson regression was used to estimate rates of increase and test for cyclical patterns. Joinpoint regression software was used to fit segmented log-linear relationships to incidence trends. RESULTS: Significant increases in incidence were noted in all but two small centres, with a maximum rate of increase of 6.6% per annum in a Polish centre. Several centres in high-incidence countries showed reducing rates of increase in more recent years. Despite this, a pooled analysis across all centres revealed a 3.4% (95% CI 2.8%, 3.9%) per annum increase in incidence rate, although there was some suggestion of a reduced rate of increase in the 2004-2008 period. Rates of increase were similar in boys and girls in the 0- to 4-year-old age group (3.7% and 3.7% per annum, respectively) and in the 5- to 9-year-old age group (3.4% and 3.7% per annum, respectively), but were higher in boys than girls in the 10- to 14-year-old age group (3.3% and 2.6% per annum, respectively). Significant 4 year periodicity was detected in four centres, with three centres showing that the most recent peak in fitted rates occurred in 2012. CONCLUSIONS/INTERPRETATION: Despite reductions in the rate of increase in some high-risk countries, the pooled estimate across centres continues to show a 3.4% increase per annum in incidence rate, suggesting a doubling in incidence rate within approximately 20 years in Europe. Although four centres showed support for a cyclical pattern of incidence with a 4 year periodicity, no plausible explanation for this can be given.


Asunto(s)
Diabetes Mellitus Tipo 1/epidemiología , Adolescente , Niño , Preescolar , Europa (Continente)/epidemiología , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Estudios Prospectivos , Sistema de Registros
2.
Am J Hum Genet ; 89(2): 201-18, 2011 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-21802064

RESUMEN

Human sexual determination is initiated by a cascade of genes that lead to the development of the fetal gonad. Whereas development of the female external genitalia does not require fetal ovarian hormones, male genital development requires the action of testicular testosterone and its more potent derivative dihydrotestosterone (DHT). The "classic" biosynthetic pathway from cholesterol to testosterone in the testis and the subsequent conversion of testosterone to DHT in genital skin is well established. Recently, an alternative pathway leading to DHT has been described in marsupials, but its potential importance to human development is unclear. AKR1C2 is an enzyme that participates in the alternative but not the classic pathway. Using a candidate gene approach, we identified AKR1C2 mutations with sex-limited recessive inheritance in four 46,XY individuals with disordered sexual development (DSD). Analysis of the inheritance of microsatellite markers excluded other candidate loci. Affected individuals had moderate to severe undervirilization at birth; when recreated by site-directed mutagenesis and expressed in bacteria, the mutant AKR1C2 had diminished but not absent catalytic activities. The 46,XY DSD individuals also carry a mutation causing aberrant splicing in AKR1C4, which encodes an enzyme with similar activity. This suggests a mode of inheritance where the severity of the developmental defect depends on the number of mutations in the two genes. An unrelated 46,XY DSD patient carried AKR1C2 mutations on both alleles, confirming the essential role of AKR1C2 and corroborating the hypothesis that both the classic and alternative pathways of testicular androgen biosynthesis are needed for normal human male sexual differentiation.


Asunto(s)
Andrógenos/biosíntesis , Vías Biosintéticas , Feto/metabolismo , Diferenciación Sexual , Testículo/embriología , Testículo/metabolismo , Empalme Alternativo/genética , Secuencia de Aminoácidos , Secuencia de Bases , Dihidrotestosterona/metabolismo , Familia , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Hidroxiesteroide Deshidrogenasas/química , Hidroxiesteroide Deshidrogenasas/genética , Hidroxiesteroide Deshidrogenasas/metabolismo , Masculino , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas Mutantes/metabolismo , Mutación/genética , Oxidorreductasas/química , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Linaje
3.
Am J Physiol Regul Integr Comp Physiol ; 306(11): R861-7, 2014 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-24694381

RESUMEN

Contracting muscle releases interleukin-6 (IL-6) enabling the metabolic switch from carbohydrate to fat utilization. Similarly, metabolism is switched during transition from fed to fasting state. Herein, we examined a putative role for IL-6 in the metabolic adaptation to normal fasting. In lean C57BL/6J mice, 6 h of food withdrawal increased gene transcription levels of IL-6 in skeletal muscle but not in white adipose tissue. Concomitantly, circulating IL-6 and free fatty acid (FFA) levels were significantly increased, whereas respiratory quotient (RQ) was reduced in 6-h fasted mice. In white adipose tissue, phosphorylation of hormone-sensitive lipase (HSL) was increased on fasting, indicating increased lipolysis. Intriguingly, fasting-induced increase in circulating IL-6 levels and parallel rise in FFA concentration were absent in obese and glucose-intolerant mice. A causative role for IL-6 in the physiological adaptation to fasting was further supported by the fact that fasting-induced increase in circulating FFA levels was significantly blunted in lean IL-6 knockout (KO) and lean C57BL/6J mice treated with neutralizing IL-6 antibody. Consistently, phosphorylation of HSL was significantly reduced in adipose tissue of IL-6-depleted mice. Hence, our findings suggest a novel role for IL-6 in energy supply during early fasting.


Asunto(s)
Ayuno/psicología , Ácidos Grasos no Esterificados/metabolismo , Interleucina-6/fisiología , Adaptación Fisiológica/fisiología , Animales , Metabolismo Energético/fisiología , Interleucina-6/deficiencia , Interleucina-6/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Animales
4.
J Lipid Res ; 54(1): 63-70, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23089915

RESUMEN

Fas (CD95) is a member of the tumor necrosis factor (TNF) receptor superfamily and plays a crucial role in the induction of apoptosis. However, like TNF, Fas can induce nonapoptotic signaling pathways. We previously demonstrated that mice lacking Fas specifically in adipocytes are partly protected from diet-induced insulin resistance, potentially via decreased delivery of FAs to the liver, as manifested by lower total liver ceramide content. In the present study, we aimed to delineate the signaling pathway involved in Fas-mediated adipocyte lipid mobilization. Treatment of differentiated 3T3-L1 adipocytes with membrane-bound Fas ligand (FasL) significantly increased lipolysis after 12 h without inducing apoptosis. In parallel, Fas activation increased phosphorylation of ERK1/2, and FasL-induced lipolysis was blunted in the presence of the ERK-inhibitor U0126 or in ERK1/2-depleted adipocytes. Furthermore, Fas activation increased phosphorylation of the Ca(2+)/calmodulin-dependent protein kinases II (CaMKII), and blocking of the CaMKII-pathway (either by the Ca(2+) chelator BAPTA or by the CaMKII inhibitor KN62) blunted FasL-induced ERK1/2 phosphorylation and glycerol release. In conclusion, we propose a novel role for CaMKII in promoting lipolysis in adipocytes.


Asunto(s)
Adipocitos/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Lipólisis , Receptor fas/metabolismo , Células 3T3-L1 , Adipocitos/citología , Animales , Apoptosis , Hidrólisis , Espacio Intracelular/metabolismo , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Fosforilación , Transducción de Señal , Esterol Esterasa/metabolismo , Triglicéridos/metabolismo
5.
Am J Physiol Endocrinol Metab ; 305(3): E388-95, 2013 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-23736545

RESUMEN

High-fat feeding for 3-4 days impairs glucose tolerance and hepatic insulin sensitivity. However, it remains unclear whether the evolving hepatic insulin resistance is due to acute lipid overload or the result of induced adipose tissue inflammation and consequent dysfunctional adipose tissue-liver cross-talk. In the present study, feeding C57Bl6/J mice a fat-enriched diet [high-fat diet (HFD)] for 4 days induced glucose intolerance, hepatic insulin resistance (as assessed by hyperinsulinemic euglycemic clamp studies), and hepatic steatosis as well as adipose tissue inflammation (i.e., TNFα expression) compared with standard chow-fed mice. Adipocyte-specific depletion of the antiapoptotic/anti-inflammatory factor Fas (CD95) attenuated adipose tissue inflammation and improved glucose tolerance as well as hepatic insulin sensitivity without altering the level of hepatic steatosis induced by HFD. In summary, our results identify adipose tissue inflammation and resulting dysfunctional adipose tissue-liver cross-talk as an early event in the development of HFD-induced hepatic insulin resistance.


Asunto(s)
Tejido Adiposo/fisiopatología , Dieta Alta en Grasa/efectos adversos , Grasas de la Dieta/toxicidad , Inflamación/fisiopatología , Resistencia a la Insulina/fisiología , Hígado/efectos de los fármacos , Adipocitos/fisiología , Animales , Área Bajo la Curva , Western Blotting , Citocinas/metabolismo , Exones/genética , Ácidos Grasos no Esterificados/sangre , Hígado Graso/metabolismo , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Insulina/sangre , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , ARN/biosíntesis , ARN/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa , Triglicéridos/sangre , Receptor fas/metabolismo
6.
Am J Physiol Endocrinol Metab ; 302(1): E153-60, 2012 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21989031

RESUMEN

Given the strong link between visceral adiposity and (hepatic) insulin resistance as well as liver steatosis, it is crucial to characterize obesity-associated alterations in adipocyte function, particularly in fat depots drained to the liver. Yet these adipose tissues are not easily accessible in humans, and the most frequently studied depot in rodents is the perigonadal, which is drained systemically. In the present study, we aimed to study alterations in lipolysis between mesenteric and perigonadal adipocytes in mice. Basal free fatty acid and glycerol release was significantly lower in perigonadal compared with mesenteric adipocytes isolated from chow-fed C57BL/6J mice. However, this difference completely vanished in high-fat diet-fed mice. Consistently, protein levels of the G(0)/G(1) switch gene 2 (G0S2), which were previously found to be inversely related to basal lipolysis, were significantly lower in mesenteric compared with perigonadal fat of chow-fed mice. Similarly, perilipin was differently expressed between the two depots. In addition, adipocyte-specific overexpression of G0S2 led to significantly decreased basal lipolysis in mesenteric adipose tissue of chow-fed mice. In conclusion, lipolysis is differently regulated between perigonadal and mesenteric adipocytes, and these depot-specific differences might be explained by altered regulation of G0S2 and/or perilipin.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular/metabolismo , Regulación de la Expresión Génica , Grasa Intraabdominal/metabolismo , Lipólisis , Fosfoproteínas/metabolismo , Adipocitos/metabolismo , Adipocitos/patología , Adiposidad , Animales , Proteínas Portadoras/genética , Proteínas de Ciclo Celular/genética , Separación Celular , Tamaño de la Célula , Citocinas/metabolismo , Grasas de la Dieta/efectos adversos , Ácidos Grasos/sangre , Grasa Intraabdominal/irrigación sanguínea , Grasa Intraabdominal/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Especificidad de Órganos , Sobrepeso/metabolismo , Sobrepeso/patología , Sobrepeso/fisiopatología , Perilipina-1 , Fosfoproteínas/genética , Sistema Porta/metabolismo , ARN Mensajero/metabolismo
7.
Am J Hum Genet ; 84(5): 658-63, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19361780

RESUMEN

A girl with a prenatal 46,XY karyotype was born with a completely normal female phenotype, including uterus and histologically normal ovaries. In mice with a similar phenotype, the ablation of M33, an ortholog of Drosophila Polycomb, causes male-to-female sex reversal. The analysis of the human homolog of M33, Chromobox homolog 2 (CBX2), in this girl revealed loss-of-function mutations that allowed us, by placing CBX2 upstream of SRY, to add an additional component to the still incomplete cascade of human sex development.


Asunto(s)
Disgenesia Gonadal 46 XY/diagnóstico , Ovario/anatomía & histología , Proteínas Represoras/genética , Animales , Niño , Preescolar , Trastornos del Desarrollo Sexual , Femenino , Humanos , Cariotipificación , Masculino , Ratones , Mutación , Ovario/metabolismo , Fenotipo , Complejo Represivo Polycomb 1 , Proteínas del Grupo Polycomb , Diagnóstico Prenatal , Proteínas Represoras/metabolismo , Procesos de Determinación del Sexo
8.
Clin Endocrinol (Oxf) ; 75(1): 39-43, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21521281

RESUMEN

CONTEXT: Aromatase deficiency in women is a rare 46, XX disorder of sex differentiation characterized by a defect in catalysing oestrogens from androgens. OBJECTIVE: To better understand this rare disorder, we searched for mutations in the CYP19A1 gene of an affected girl and analysed their functional consequences. DESIGN AND PATIENT: We examined a girl presenting with clitoral hypertrophy at birth and mild maternal virilization (acne) during pregnancy. MAIN OUTCOME MEASUREMENT: A genotype-phenotype correlation was found. RESULTS: By direct sequencing of the CYP19A1 gene, we identified a heterozygous A>G mutation (c. A1374G) mutation in exon IX, leading to the missense p.N411S in the P450Aro protein and a heterozygous placenta promoter variant -41 base pairs upstream of exon I.1. Aromatase enzyme activity was completely lost when the mutant p.N411S protein was expressed in COS-1 cells. The placenta promoter variant had a significantly reduced (-50%) transactivation ability compared to wild-type. CONCLUSION: Our data describe a novel loss-of-function missense mutation in CYP19A1 combined with the first-described variant of the placenta promoter with a significant reduction in function, likely to be the molecular basis of this rare 46, XX disorder of sex development. This seems to represent a unique case of aromatase deficiency occurring in utero only.


Asunto(s)
Trastornos del Desarrollo Sexual 46, XX/genética , Aromatasa/deficiencia , Ginecomastia/genética , Infertilidad Masculina/genética , Errores Innatos del Metabolismo/genética , Trastornos del Desarrollo Sexual 46, XX/patología , Adulto , Aromatasa/genética , Niño , Femenino , Genotipo , Ginecomastia/patología , Humanos , Infertilidad Masculina/patología , Errores Innatos del Metabolismo/patología , Mutación Missense , Fenotipo , Placenta/metabolismo , Embarazo , Regiones Promotoras Genéticas
9.
N Engl J Med ; 351(8): 792-8, 2004 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-15317892

RESUMEN

WNT4, a secreted protein that suppresses male sexual differentiation, is thought to repress the biosynthesis of gonadal androgen in female mammals. An 18-year-old woman presented with primary amenorrhea and an absence of müllerian-derived structures, unilateral renal agenesis, and clinical signs of androgen excess--a phenotype resembling the Mayer-Rokitansky-Küster-Hauser syndrome and remarkably similar to that of female Wnt4-knockout mice. A genetic evaluation revealed a loss-of-function mutation in the WNT4 gene. WNT4 appears to be important in the development and maintenance of the female phenotype in women, by means of the regulation of müllerian-duct formation and control of ovarian steroidogenesis.


Asunto(s)
Conductos Paramesonéfricos/anomalías , Proteínas Proto-Oncogénicas/genética , Anomalías Urogenitales/genética , Virilismo/genética , Adolescente , Amenorrea , Análisis Mutacional de ADN , Femenino , Humanos , Cariotipificación , Mutación , Síndrome , Proteínas Wnt , Proteína Wnt4
10.
Ann Endocrinol (Paris) ; 78(3): 156-161, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28624161

RESUMEN

OBJECTIVE: Steroidogenic factor 1 (SF-1/NR5A1) plays a crucial role in regulating adrenal development, gonad determination and differentiation, and in the hypothalamic-pituitary control of reproduction and metabolism. In men (46, XY), it is known that mutations in SF-1/NR5A1 gene cause a wide phenotypic spectrum with variable degrees of undervirilization. In recent years, the role of SF-1 in the ovarian function was increasingly discussed and alterations in the gene were related to primary ovarian insufficiency. We describe the follow-up of a 46, XX affected woman with a SF-1 mutation and by comparing our case with the known manifestations reported in the literature, we try to further elucidate the function of SF-1 in the ovary. RESULTS: During infancy, adrenal insufficiency was the only clinical sign of the loss-of-function as ovarian development and function seemed normal. To date, this young woman aged 16.5 years shows normal growth, normal BMI and psychomotor development, has a normal puberty and regular menstruation. CONCLUSION: This report shows one, to date uniquely described, phenotypic variant of SF-1 mutation in a 46, XX affected person with adrenocortical insufficiency but no ovarian dysfunction nor disturbance of pubertal development. To follow the natural history of SF-1 mutation in a 46, XX individual will further shed light on its role in the ovarian function and thus will help to counsel affected patients in future.


Asunto(s)
Trastornos del Desarrollo Sexual 46, XX/genética , Enfermedad de Addison/genética , Factor Esteroidogénico 1/genética , Trastornos del Desarrollo Sexual 46, XX/complicaciones , Enfermedad de Addison/complicaciones , Adolescente , Femenino , Estudios de Seguimiento , Gráficos de Crecimiento , Humanos , Ovario/fisiopatología , Fenotipo , Insuficiencia Ovárica Primaria/genética , Factor Esteroidogénico 1/deficiencia
11.
Diabetes ; 51(7): 2301-5, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12086964

RESUMEN

Wolcott-Rallison syndrome (WRS) is an autosomal recessive disorder characterized by neonatal or early infancy type 1 diabetes, epiphyseal dysplasia, and growth retardation. Mutations in the EIF2AK3 gene, encoding the eukaryotic initiation factor 2alpha-kinase 3 (EIF2AK3), have been found in WRS patients. Here we describe a girl who came to our attention at 2 months of age with severe hypertonic dehydration and diabetic ketoacidosis. A diagnosis of type 1 diabetes was made and insulin treatment initiated. Growth retardation and microcephaly were also present. Anti-islet cell autoantibodies were negative, and mitochondrial diabetes was excluded. Imaging revealed a hypoplastic pancreas and typical signs of spondylo-epiphyseal dysplasia. The diagnosis of WRS was therefore made at age 5 years. Sequencing analysis of her EIF2AK3 gene revealed the presence of a homozygous T to C exchange in exon 13 leading to the missense serine 877 proline mutation. The mutated kinase, although it partly retains the ability of autophosphorylation, is unable to phosphorylate its natural substrate, eukaryotic initiation factor 2alpha (eIF2alpha). This is the first case in which the pathophysiological role of EIF2AK3 deficiency in WRS is confirmed at the molecular level. Our data demonstrate that EIF2AK3 kinase activity is essential for pancreas islet function and bone development in humans, and we suggest EIF2AK3 as a possible target for therapeutic intervention in diabetes.


Asunto(s)
Anomalías Múltiples/genética , Mutación , eIF-2 Quinasa/genética , Secuencia de Bases , Femenino , Humanos , Lactante , Masculino , Páncreas/patología , Linaje , Reacción en Cadena de la Polimerasa
12.
Horm Res Paediatr ; 84(1): 43-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25968592

RESUMEN

BACKGROUND/AIMS: Primary hypoaldosteronism is a rare inborn disorder with life-threatening symptoms in newborns and infants due to an aldosterone synthase defect. Diagnosis is often difficult as the plasma aldosterone concentration (PAC) can remain within the normal range and thus lead to misinterpretation and delayed initiation of life-saving therapy. We aimed to test the eligibility of the PAC/plasma renin concentration (PRC) ratio as a tool for the diagnosis of primary hypoaldosteronism in newborns and infants. Meth ods: Data of 9 patients aged 15 days to 12 months at the time of diagnosis were collected. The diagnosis of primary hypoaldosteronism was based on clinical and laboratory findings over a period of 12 years in 3 different centers in Switzerland. To enable a valid comparison, the values of PAC and PRC were correlated to reference methods. RESULTS: In 6 patients, the PAC/PRC ratio could be determined and showed constantly decreased values <1 (pmol/l)/(mU/l). In 2 patients, renin was noted as plasma renin activity (PRA). PAC/PRA ratios were also clearly decreased. The diagnosis was subsequently genetically confirmed in 8 patients. CONCLUSION: A PAC/PRC ratio <1 pmol/mU and a PAC/PRA ratio <28 (pmol/l)/(ng/ml × h) are reliable tools to identify primary hypoaldosteronism in newborns and infants and help to diagnose this life-threatening disease faster.


Asunto(s)
Aldosterona/sangre , Hipoaldosteronismo/sangre , Hipoaldosteronismo/diagnóstico , Renina/sangre , Femenino , Humanos , Lactante , Recién Nacido , Masculino
13.
Diabetes ; 64(4): 1131-41, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25325737

RESUMEN

Reduced kidney mass and/or function may result in multiple metabolic derangements, including insulin resistance. However, underlying mechanisms are poorly understood. Herein, we aimed to determine the impact of reduced kidney mass on glucose metabolism in lean and obese mice. To that end, 7-week-old C57BL/6J mice underwent uninephrectomy (UniNx) or sham operation. After surgery, animals were fed either a chow (standard) diet or a high-fat diet (HFD), and glucose homeostasis was assessed 20 weeks after surgery. Intraperitoneal glucose tolerance was similar in sham-operated and UniNx mice. However, insulin-stimulated glucose disposal in vivo was significantly diminished in UniNx mice, whereas insulin-stimulated glucose uptake into isolated skeletal muscle was similar in sham-operated and UniNx mice. Of note, capillary density was significantly reduced in skeletal muscle of HFD-fed UniNx mice. In contrast, hepatic insulin sensitivity was improved in UniNx mice. Furthermore, adipose tissue hypoxia-inducible factor 1α expression and inflammation were reduced in HFD-fed UniNx mice. Treatment with the angiotensin II receptor blocker telmisartan improved glucose tolerance and hepatic insulin sensitivity in HFD-fed sham-operated but not UniNx mice. In conclusion, UniNx protects from obesity-induced adipose tissue inflammation and hepatic insulin resistance, but it reduces muscle capillary density and, thus, deteriorates HFD-induced skeletal muscle glucose disposal.


Asunto(s)
Tejido Adiposo/metabolismo , Resistencia a la Insulina/fisiología , Riñón/metabolismo , Hígado/metabolismo , Músculo Esquelético/metabolismo , Obesidad/metabolismo , Animales , Dieta Alta en Grasa , Hígado Graso/metabolismo , Glucosa/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Inflamación/metabolismo , Insulina/metabolismo , Riñón/cirugía , Masculino , Ratones , Ratones Obesos , Triglicéridos/metabolismo
14.
J Clin Endocrinol Metab ; 87(9): 4106-10, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12213856

RESUMEN

Newborn screening for congenital adrenal hyperplasia (CAH) is justified by the sometimes difficult clinical diagnosis and the risks associated with missed diagnosis, particularly the life-threatening salt-wasting crisis. In Switzerland, nationwide screening for CAH by measuring 17-hydroxyprogesterone levels in dried blood spots was introduced in 1992. At the Zurich University Children's Hospital, 50% of the population of Switzerland is screened. The aim of the study was to evaluate the efficiency of the Zurich screening program. Between January 1, 1993, and May 31, 2001, 333,221 newborns were screened for CAH. Thirty-one newborns had CAH (incidence, 1 in 10,749); 30 were detected through screening (sensitivity, 97%). A recall for suspected CAH was performed in only 60 cases, corresponding to a very low recall rate (0.0018%). In 30 recalls CAH was confirmed (positive predictive value, 50%; specificity, 99.99%). Fifteen of 31 patients profited from screening, as CAH had not been recognized clinically. The timely availability of screening results made therapy possible within the first week of life in most cases and helped in preventing salt-wasting crisis in all patients. With a sensitivity of 97%, a specificity of 99.99%, and a positive predictive value of 50%, the Zurich neonatal screening program for CAH can be considered highly reliable.


Asunto(s)
Hiperplasia Suprarrenal Congénita/diagnóstico , 17-alfa-Hidroxiprogesterona/sangre , Hiperplasia Suprarrenal Congénita/epidemiología , Reacciones Falso Positivas , Femenino , Edad Gestacional , Humanos , Incidencia , Recién Nacido , Masculino , Tamizaje Neonatal , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Suiza/epidemiología
15.
J Clin Endocrinol Metab ; 87(9): 4378-82, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12213902

RESUMEN

Mutations in the X-linked androgen receptor (AR) gene cause the androgen insensitivity syndrome by impairing androgen-dependent male sexual differentiation to varying degrees. Complete androgen insensitivity (CAIS) yields an external female phenotype, whereas affected cases of partial androgen insensitivity have various ambiguities of the genitalia. Here we describe a 46,XY phenotypically female patient with all of the characteristics of CAIS, i.e. primary amenorrhea, no axillary or pubic hair, female external genitalia, no uterus, and undescended testes. Defects in testosterone and dihydrotestosterone synthesis were excluded. The molecular basis of the disease was clarified by means of direct sequencing of PCR-amplified exonic fragments of the AR gene. An A to C transition in exon 4 of the AR gene led to a novel missense His(689)Pro mutation in the ligand-binding domain of the AR protein. Functional studies demonstrated that the mutated AR is unable to efficiently bind its natural ligand dihydrotestosterone and to trans-activate known androgen response elements. Analysis of the structural consequences of the His(689)Pro substitution suggests that this mutation is likely to perturb the conformation of the second helix of the AR ligand-binding domain, which contains residues critical for androgen binding.


Asunto(s)
Síndrome de Resistencia Androgénica/genética , Mutación Missense , Receptores Androgénicos/química , Receptores Androgénicos/genética , Cromosoma X , Adolescente , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Cristalografía por Rayos X , Cartilla de ADN , Exones , Femenino , Amplificación de Genes , Humanos , Cinética , Masculino , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Estructura Secundaria de Proteína , Ratas , Receptores Androgénicos/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Xenopus
16.
Adipocyte ; 3(2): 115-20, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24719784

RESUMEN

A short bout of high fat diet (HFD) impairs glucose tolerance and hepatic insulin sensitivity. We recently identified adipose tissue inflammation and resulting dysfunctional adipose tissue-liver cross-talk as an early event in the development of HFD-induced hepatic insulin resistance. In particular, reducing white adipose tissue (WAT) inflammation by adipocyte-specific depletion of Fas/CD95 protected mice from developing hepatic insulin resistance but not hepatic steatosis. Herein, we expanded our previous work and determined the impact of four days of HFD on lipolytic activity of isolated adipocytes. Compared with chow-fed mice, the degree of basal and isoproterenol-stimulated free fatty acid (FFA) and glycerol release was similar in HFD-fed animals. Moreover, insulin's ability to suppress lipolysis remained intact, suggesting retained insulin sensitivity. Despite unaltered lipolysis, circulating FFA concentrations were greatly increased in non-fasted HFD-fed mice. In conclusion, a short-term HFD challenge does not affect lipolytic function of adipocytes. The observed increase of circulating FFA levels in randomly fed animals may rather be the result of increased dietary fat supply.

17.
J Clin Endocrinol Metab ; 99(1): E36-44, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24178789

RESUMEN

CONTEXT: Deletion of the death receptor Fas (CD95) in adipocytes of mice is associated with improved insulin sensitivity and reduced adipose tissue (AT) inflammation. OBJECTIVE: Here we investigate the relationship of AT Fas with human obesity. DESIGN AND METHODS: In paired samples of omental and sc AT from 256 lean and obese (including insulin-sensitive and insulin-resistant subgroups; n=60) participants, we investigated whether Fas and Fas-ligand (FasL) mRNA expression is fat depot-specific, altered in obesity, and related to measures of AT inflammation and insulin sensitivity. In addition, AT Fas mRNA expression was measured in 16 obese patients after significant weight loss of 45±6.3 kg in the context of a two-step bariatric surgery strategy. RESULTS: Fas and FasL are significantly higher expressed in omental (OM) compared to sc AT. Fas expression correlates with body mass index (OM, r2=0.44; sc, r2=0.14), AT macrophage infiltration (OM, r2=0.36; sc, r2=0.16), and glucose infusion rate in euglycemic-hyperinsulinemic clamps (OM, r2=0.17; sc, r2=0.13) (P<.05 for all). FasL expression most strongly correlates with adipocyte size (OM, r2=0.32; sc, r2=0.17) and AT macrophage infiltration (OM, r2=0.46; sc, r2=0.02). Insulin-sensitive obese individuals had significantly lower Fas and FasL expression than insulin-resistant obese individuals. Significant weight loss 12 months after gastric sleeve resection is associated with a significantly reduced Fas expression in OM and sc fat depots. CONCLUSIONS: Independently of body weight, increased Fas expression may contribute to impaired insulin sensitivity and AT dysfunction in obesity. Moreover, significant weight loss reduces Fas expression in OM and sc fat depots.


Asunto(s)
Tejido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/genética , Proteína Ligando Fas/genética , Resistencia a la Insulina/genética , Obesidad/genética , Receptor fas/genética , Adulto , Cirugía Bariátrica , Índice de Masa Corporal , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/metabolismo , Proteína Ligando Fas/metabolismo , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Obesidad/metabolismo , Obesidad/cirugía , Delgadez/genética , Delgadez/metabolismo , Pérdida de Peso/genética , Receptor fas/metabolismo
18.
EMBO Mol Med ; 6(1): 43-56, 2014 01.
Artículo en Inglés | MEDLINE | ID: mdl-24203314

RESUMEN

Low-grade inflammation in adipose tissue and liver has been implicated in obesity-associated insulin resistance and type 2 diabetes. Yet, the contribution of inflammatory cells to the pathogenesis of skeletal muscle insulin resistance remains elusive. In a large cohort of obese human individuals, blood monocyte Fas (CD95) expression correlated with systemic and skeletal muscle insulin resistance. To test a causal role for myeloid cell Fas expression in the development of skeletal muscle insulin resistance, we generated myeloid/haematopoietic cell-specific Fas-depleted mice. Myeloid/haematopoietic Fas deficiency prevented the development of glucose intolerance in high fat-fed mice, in ob/ob mice, and in mice acutely challenged by LPS. In vivo, ex vivo and in vitro studies demonstrated preservation of muscle insulin responsiveness with no effect on adipose tissue or liver. Studies using neutralizing antibodies demonstrated a role for TNFα as mediator between myeloid Fas and skeletal muscle insulin resistance, supported by significant correlations between monocyte Fas expression and circulating TNFα in humans. In conclusion, our results demonstrate an unanticipated crosstalk between myeloid cells and skeletal muscle in the development of obesity-associated insulin resistance.


Asunto(s)
Regulación de la Expresión Génica , Resistencia a la Insulina , Monocitos/metabolismo , Músculo Esquelético/metabolismo , Obesidad/metabolismo , Receptor fas/metabolismo , Adulto , Anciano , Animales , Anticuerpos Neutralizantes/inmunología , Estudios de Cohortes , Estudios Transversales , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Persona de Mediana Edad , Obesidad/complicaciones , Receptor fas/deficiencia , Receptor fas/genética
19.
Adipocyte ; 1(3): 153-156, 2012 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-23700524

RESUMEN

Fat depots of different localization vary in their biological/metabolic function. We recently provided evidence for different regulation of lipolysis between perigonadal and mesenteric adipocytes; in particular insulin-induced suppression of lipolysis was significantly higher in perigonadal compared with mesenteric adipocytes in chow-fed mice. Moreover, insulin's anti-lipolytic effect was maintained in mesenteric but lost in perigonadal adipocytes under high fat diet (HFD). Herein, we expanded our previous study and included inguinal (subcutaneous) adipocytes in our analysis. When compared with perigonadal adipocytes, inguinal adipocytes are equally sensitive to insulin's anti-lipolytic effect under chow diet. However, they remain insulin-sensitive under HFD. Moreover, insulin-stimulated glucose incorporation was equally blunted in adipocytes of all three depots in HFD-fed mice. In conclusion, regulation of insulin sensitivity in murine adipocytes is diet-, depot- and function-dependent.

20.
Diabetes ; 60(1): 56-63, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20956499

RESUMEN

OBJECTIVE: The "portal hypothesis" proposes that the liver is directly exposed to free fatty acids and cytokines increasingly released from visceral fat tissue into the portal vein of obese subjects, thus rendering visceral fat accumulation particularly hazardous for the development of hepatic insulin resistance and type 2 diabetes. In the present study, we used a fat transplantation paradigm to (artificially) increase intra-abdominal fat mass to test the hypothesis that venous drainage of fat tissue determines its impact on glucose homeostasis. RESEARCH DESIGN AND METHODS: Epididymal fat pads of C57Bl6/J donor mice were transplanted into littermates, either to the parietal peritoneum (caval/systemic venous drainage) or, by using a novel approach, to the mesenterium, which confers portal venous drainage. RESULTS: Only mice receiving the portal drained fat transplant developed impaired glucose tolerance and hepatic insulin resistance. mRNA expression of proinflammatory cytokines was increased in both portally and systemically transplanted fat pads. However, portal vein (but not systemic) plasma levels of interleukin (IL)-6 were elevated only in mice receiving a portal fat transplant. Intriguingly, mice receiving portal drained transplants from IL-6 knockout mice showed normal glucose tolerance. CONCLUSIONS: These results demonstrate that the metabolic fate of intra-abdominal fat tissue transplantation is determined by the delivery of inflammatory cytokines to the liver specifically via the portal system, providing direct evidence in support of the portal hypothesis.


Asunto(s)
Tejido Adiposo/trasplante , Grasa Intraabdominal/trasplante , Adiponectina/sangre , Animales , Glucemia/metabolismo , Citocinas/genética , Cartilla de ADN , Epidídimo , Ácidos Grasos no Esterificados/sangre , Técnica de Clampeo de la Glucosa , Intolerancia a la Glucosa/metabolismo , Hiperinsulinismo/sangre , Inflamación/genética , Insulina/sangre , Resistencia a la Insulina , Interleucina-6/deficiencia , Leptina/sangre , Masculino , Mesenterio/cirugía , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Peritoneo/cirugía , ARN/genética , ARN/aislamiento & purificación , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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