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Context: Paragangliomas (PGLs) are rare tumors in adrenal and extra-adrenal locations. Metastasis are found in approximately 5% to 35% of PGLs, and there are no reliable predictors of metastatic disease. Objective: This work aimed to develop a prognostic score of metastatic potential in PGLs. Methods: A retrospective analysis was conducted of clinical data from a cohort with PGLs and tumor histological assessment. Patients were divided into metastatic PGL (presence of metastasis) and nonmetastatic PGL (absence of metastasis ≥96 months of follow-up) groups. Univariate and multivariable analysis were performed to identify predictors of metastatic potential. A prognostic score was developed based on coefficients of multivariable analysis. Kaplan-Meier curves were generated to estimate disease-specific survival (DSS). Results: Out of 263 patients, 35 patients had metastatic PGL and 110 patients had nonmetastatic PGL. In multivariable analysis, 4 features were independently related to metastatic disease and composed the Prognostic Score of Paragangliomas (PSPGL): presence of central or confluent necrosis (33 points), more than 3â mitosis/10 high-power field (HPF) (28 points), extension into adipose tissue (20 points), and extra-adrenal location (19 points). A PSPGL of 24 or greater showed similar sensitivity with higher specificity than the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP). PSPGL less than or equal to 20 was associated with a risk of metastasis of approximately 10%, whereas a PSPGL of 40 or greater was associated with approximately 80%. The presence of metastasis and Ki-67 of 3% or greater were related to lower DSS. Conclusion: The PSPGL, composed of 4 easy-to-assess parameters, demonstrated good performance in predicting metastatic potential and good ability in estimating metastasis risk.
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BACKGROUND: In kidney transplant patients, parathyroidectomy is associated with an acute decrease in renal function. Acute and chronic effects of parathyroidectomy on renal function have not been extensively studied in primary hyperparathyroidism (PHPT). METHODS: This retrospective cohort study included 494 patients undergoing parathyroidectomy for PHPT. Acute renal changes were evaluated daily until day 4 post-parathyroidectomy and were stratified according to acute kidney injury (AKI) criteria. Biochemical assessment included serum creatinine, total and ionized calcium, parathyroid hormone (PTH), and 25-hydroxyvitamin D (25OHD). The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. We compared preoperative and postoperative renal function up to 5 years of follow-up. RESULTS: A total of 391 (79.1%) patients were female, and 422 (85.4%) were non-African American. The median age was 58 years old. The median (first and third quartiles) preoperative serum creatinine, PTH and total calcium levels were 0.81 mg/dL (0.68-1.01), 154.5 pg/mL (106-238.5), and 10.9 mg/dL (10.3-11.5), respectively. The median (first and third quartiles) preoperative eGFR was 86 mL/min/1.73 m2 (65-101.3). After surgery, the median acute decrease in the eGFR was 21 mL/min/1.73 m2 (p<0.0001). Acutely, 41.1% of patients developed stage 1 AKI, 5.9% developed stage 2 AKI, and 1.8% developed stage 3 AKI. The acute eGFR decrease (%) was correlated with age and PTH, calcium and preoperative creatinine levels in univariate analysis. Multivariate analysis showed that the acute change was related to age and preoperative values of ionized calcium, phosphorus and creatinine. The change at 12 months was related to sex, preoperative creatinine and 25OHD. Permanent reduction in the eGFR occurred in 60.7% of patients after an acute episode. CONCLUSION: There was significant acute impairment in renal function after parathyroidectomy for PHPT, and almost half of the patients met the criteria for AKI. Significant eGFR recovery was observed during the first month after surgery, but a small permanent reduction may occur. Patients treated for PHPT seemed to present with prominent renal dysfunction compared to patients who underwent thyroidectomy.
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Injúria Renal Aguda/epidemiologia , Hiperparatireoidismo Primário/cirurgia , Paratireoidectomia/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Injúria Renal Aguda/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Creatinina/sangue , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Vitamina D/análogos & derivados , Vitamina D/sangueRESUMO
ABSTRACT Objective To present an update on the diagnosis and treatment of hypoparathyroidism based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM; Brazilian Society of Endocrinology and Metabolism) was invited to prepare a document following the rules set by the Guidelines Program of the Associação Médica Brasileira (AMB; Brazilian Medical Association). Relevant papers were retrieved from the databases MEDLINE/PubMed, LILACS, and SciELO, and the evidence derived from each article was classified into recommendation levels according to scientific strength and study type. Conclusion An update on the recent scientific literature addressing hypoparathyroidism is presented to serve as a basis for the diagnosis and treatment of this condition in Brazil.
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Humanos , Medicina Baseada em Evidências , Hipoparatireoidismo/diagnóstico , Hipoparatireoidismo/tratamento farmacológico , Sociedades Médicas , Brasil , Hipoparatireoidismo/etiologiaRESUMO
OBJECTIVE: The increasing incidence of thyroid nodules demands identification of risk factors for malignant disease. Several studies suggested the association of higher TSH levels with cancer, but influence of 25-hydroxyvitamin D (25OHD) is controversial. This study aimed to identify the relationship of thyroid cancer with higher TSH levels and hypovitaminosis D and to evaluate their influence on prognostic characteristics of papillary thyroid carcinomas (PTC). METHODS: We retrospectively evaluated 433 patients submitted to thyroidectomy for thyroid nodules. Patients were categorized according to quartiles of TSH and 25OHD levels. Clinicopathological features were analyzed. RESULTS: Subjects with thyroid carcinomas were more frequently male and younger compared to those with benign disease. Their median TSH levels were higher and adjusted odds-ratio (OR) for cancer in the highest-quartile of TSH (> 2.4 mUI/mL) was 2.36 (1.36-4.09). Although vitamin D deficiency/insufficiency was prevalent in our cohort (84%), no significant differences in 25OHD levels or quartile distribution were observed between benign and malignant cases. Among 187 patients with PTC, analyses of prognostic features revealed increased risk of lymph nodes metastases for subjects with highest-quartile TSH levels (OR = 3.7, p = 0.029). Decreased 25OHD levels were not overtly associated with poor prognosis in PTC. CONCLUSIONS: In this cross-sectional cohort, higher TSH levels increased the risk of cancer in thyroid nodules and influenced its prognosis, particularly favoring lymph nodes metastases. On the other hand, no association was found between 25OHD levels and thyroid carcinoma risk or prognosis, suggesting that serum 25OHD determination may not contribute to risk assessment workup of thyroid nodules.
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Carcinoma/patologia , Neoplasias da Glândula Tireoide/patologia , Tireotropina/metabolismo , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Adulto , Idoso , Carcinoma/metabolismo , Carcinoma Papilar , Estudos Transversais , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/metabolismo , Vitamina D/metabolismoRESUMO
ABSTRACT The pathogenesis of osteoporosis, a common disease with great morbidity and mortality, comprises environmental and genetic factors. As with other complex disorders, the genetic basis of osteoporosis has been difficult to identify. Nevertheless, several approaches have been undertaken in the past decades in order to identify candidate genes for bone fragility, including the study of rare monogenic syndromes with striking bone phenotypes (e.g. osteogenesis imperfecta and osteopetroses), the analysis of individuals or families with extreme osteoporotic phenotypes (e.g. idiopathic juvenile and pregnancy-related osteoporosis), and, chiefly, genome-wide association studies (GWAS) in large populations. Altogether, these efforts have greatly increased the understanding of molecular mechanisms behind bone remodelling, which has rapidly translated into the development of novel therapeutic strategies, exemplified by the tales of cathepsin K (CTSK) and sclerostin (SOST). Additional biological evidence of involvement in bone physiology still lacks for several candidate genes arisen from GWAS, opening an opportunity for the discovery of new mechanisms regulating bone strength, particularly with the advent of high-throughput genomic technologies. In this review, candidate genes for bone fragility will be presented in comprehensive tables and discussed with regard to how their association with osteoporosis emerged, highlighting key players such as LRP5, WNT1 and PLS3. Current limitations in our understanding of the genetic contribution to osteoporosis, such as yet unidentified genetic modifiers, may be overcome in the near future with better genotypic and phenotypic characterisation of large populations and the detailed study of candidate genes in informative individuals with marked phenotype.
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Humanos , Masculino , Feminino , Osteoporose/genética , Estudo de Associação Genômica Ampla/métodos , Mutação , Densidade Óssea/genética , Fatores de Risco , Via de Sinalização WntRESUMO
POD-1/TCF21 may play a crucial role in adrenal and gonadal homeostasis and represses Sf-1/SF-1 expression in adrenocortical tumor cells. SF-1 and LRH-1 are members of the Fzt-F1 subfamily of nuclear receptors. LRH-1 is involved in several biological processes, and both LRH-1 and its repressor SHP are involved in many types of cancer. In order to assess whether POD-1 can regulate LRH-1 via the same mechanism that regulates SF-1, we analyzed the endogenous mRNA levels of POD-1, SHP, and LRH-1 in hepatocarcinoma and adrenocortical tumor cells using qRT-PCR. Hereafter, these tumor cells were transiently transfected with pCMVMycPod-1, and the effect of POD-1 overexpression on E-box elements in the LRH-1 and SHP promoter region were analyzed by ChIP assay. Also, Cyclin E1 protein expression was analyzed to detect cell cycle progression. We found that POD-1 overexpression significantly decreased SHP/SHP mRNA and protein levels through POD-1 binding to the E-box sequence in the SHP promoter. Decreased SHP expression affected LRH-1 regulation and increased Cyclin E1. These findings show that POD-1/TCF21 regulates SF-1 and LRH-1 by distinct mechanisms, contributing to the understanding of POD-1 involvement and its mechanisms of action in adrenal and liver tumorigenesis, which could lead to the discovery of relevant biomarkers.
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Neoplasias do Córtex Suprarrenal/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Carcinoma Hepatocelular/patologia , Ciclo Celular , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/patologia , Receptores Citoplasmáticos e Nucleares/genética , Neoplasias do Córtex Suprarrenal/genética , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinoma Hepatocelular/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Cromatina/metabolismo , Ciclina E/metabolismo , Regulação para Baixo/genética , Elementos E-Box/genética , Humanos , Neoplasias Hepáticas/genética , Camundongos , Dados de Sequência Molecular , Ligação Proteica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Reprodutibilidade dos TestesRESUMO
Paget's disease of bone (PDB) is a chronic progressive disorder of bone metabolism that may go undetected for many years, and endocrinologists should be alert to its clinical signs and promptly diagnose and treat PDB before it results in irreversible complications, such as deformity, fracture or neurological sequelae. Most commonly, PDB is suspected upon the incidental finding of elevated serum alkaline phosphatase levels or a radiographic abnormality in an otherwise healthy individual above 55 years of age. Some of these individuals may have symptoms such as bone pain or enlargement with increased warmth. In general, a basic laboratory evaluation of bone metabolism, plain radiographies of affected bones and bone scintigraphy are sufficient to corroborate the diagnosis. Antiresorptive therapy with bisphosphonates is the mainstay of treatment of symptomatic PDB, and intravenous zoledronic acid has emerged as an effective and safe treatment option, leading to sustained remission and improved quality of life. It is extremely important, though, to ensure calcium and vitamin D sufficiency before and during treatment in order to prevent hypocalcemia. The benefit of treating all asymptomatic patients is not clear, but treatment is warranted if the pagetic lesion is located in a site where progression to fracture, deformity, or compression would significantly impair the patient quality of life. This mini-review focuses on important aspects of the diagnosis and treatment of PDB.
A doença de Paget dos ossos (PDB) é uma doença progressiva e crônica do metabolismo ósseo que pode passar despercebida por muitos anos. Os endocrinologistas devem ficar alertas aos seus sinais clínicos e diagnosticar e tratar a PDB imediatamente, antes que ela gere complicações irreversíveis, como deformidade, fratura ou sequelas neurológicas. Mais comumente, suspeita-se da PBD após o achado incidental de níveis elevados de fosfatase alcalina no soro, ou anormalidades radiográficas em indivíduos aparentemente saudáveis com mais de 55 anos de idade. Alguns desses indivíduos podem apresentar sintomas, como a dor ou aumento ósseo com temperatura aumentada. Em geral, a avaliação laboratorial básica de metabolismo ósseo, radiografias simples dos ossos afetados e cintilografia óssea são suficientes para corroborar o diagnóstico. O tratamento antirreabsortivo com bifosfonatos é o principal tratamento da PDB sintomática, e o ácido zoledrônico intravenoso passou a ser uma opção de tratamento segura e eficiente, levando à manutenção da remissão e à melhora da qualidade de vida. É extremamente importante, entretanto, garantir níveis adequados de cálcio e vitamina D antes e durante o tratamento para se evitar a hipocalcemia. O benefício de se tratar todos os pacientes assintomáticos não está claro, mas o tratamento é recomendado se a localização da lesão pagética sugerir progressão para fratura, deformidade ou compressão que comprometam a qualidade de vida. Esta minirrevisão concentra-se em importantes aspectos do diagnóstico e tratamento da PDB.
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Humanos , Conservadores da Densidade Óssea/uso terapêutico , Difosfonatos/uso terapêutico , Osteíte Deformante/tratamento farmacológico , Osteíte Deformante , Fosfatase Alcalina/sangue , Doenças Assintomáticas/terapia , Cálcio/sangue , Diagnóstico Diferencial , Imidazóis/uso terapêutico , Vitamina D/sangueRESUMO
Pod-1/Tcf21 is expressed at epithelial-mesenchymal interaction sites during development of many organs. Different approaches have demonstrated that Pod-1 transcriptionally inhibits Sf-1/NR5A1 during gonadal development. Disruption of Sf-1 can lead to disorders of adrenal development, while increased dosage of SF-1 has been related to increased adrenal cell proliferation and tumorigenesis. In this study, we analyzed whether POD-1 overexpression inhibits the endogenous Sf-1 expression in human and mouse adrenocortical tumor cells. Cells were transiently transfected with luciferase reporter gene under the control of Sf-1 promoter and with an expression vector encoding Pod-1. Pod-1 construct inhibited the transcription of the Sf1/Luc reporter gene in a dose-dependent manner in mouse Y-1 adrenocortical carcinoma (ACC) cells, and inhibited endogenous SF-1 expression in the human H295R and ACC-T36 adrenocortical carcinoma cells. These results were validated by chromatin immunoprecipitation assay with POD-1-transfected H295R cells using primers specific to E-box sequence in SF-1 promoter region, indicating that POD-1 binds to the SF-1 E-box promoter. Moreover, POD-1 over-expression resulted in a decrease in expression of the SF-1 target gene, StAR (Steroidogenic Acute Regulatory Protein). Lastly, while the induced expression of POD-1 did not affect the cell viability of H295R/POD-1 or ACC-T36/POD-1 cells, the most significantly enriched KEGG pathways for genes negatively correlated to POD-1/TCF21 in 33 human ACCs were those associated with cell cycle genes.
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Neoplasias do Córtex Suprarrenal/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Elementos E-Box , Fosfoproteínas/biossíntese , Fator Esteroidogênico 1/biossíntese , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Humanos , Camundongos , Regiões Promotoras Genéticas , Transcrição GênicaRESUMO
IMAGe syndrome (intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita and genital anomalies) is an undergrowth developmental disorder with life-threatening consequences. An identity-by-descent analysis in a family with IMAGe syndrome identified a 17.2-Mb locus on chromosome 11p15 that segregated in the affected family members. Targeted exon array capture of the disease locus, followed by high-throughput genomic sequencing and validation by dideoxy sequencing, identified missense mutations in the imprinted gene CDKN1C (also known as P57KIP2) in two familial and four unrelated patients. A familial analysis showed an imprinted mode of inheritance in which only maternal transmission of the mutation resulted in IMAGe syndrome. CDKN1C inhibits cell-cycle progression, and we found that targeted expression of IMAGe-associated CDKN1C mutations in Drosophila caused severe eye growth defects compared to wild-type CDKN1C, suggesting a gain-of-function mechanism. All IMAGe-associated mutations clustered in the PCNA-binding domain of CDKN1C and resulted in loss of PCNA binding, distinguishing them from the mutations of CDKN1C that cause Beckwith-Wiedemann syndrome, an overgrowth syndrome.
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Hiperplasia Suprarrenal Congênita/genética , Inibidor de Quinase Dependente de Ciclina p57/genética , Retardo do Crescimento Fetal/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Mutação , Osteocondrodisplasias/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Hiperplasia Suprarrenal Congênita/metabolismo , Insuficiência Adrenal , Animais , Síndrome de Beckwith-Wiedemann/genética , Síndrome de Beckwith-Wiedemann/metabolismo , Linhagem Celular Transformada , Cromossomos Humanos Par 11 , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Drosophila , Éxons , Feminino , Retardo do Crescimento Fetal/metabolismo , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Loci Gênicos , Predisposição Genética para Doença , Células HEK293 , Humanos , Hipoadrenocorticismo Familiar , Masculino , Osteocondrodisplasias/metabolismo , Antígeno Nuclear de Célula em Proliferação/genética , Ligação Proteica/genética , Estrutura Terciária de Proteína/genéticaRESUMO
CONTEXT: Jansen's metaphyseal chondrodysplasia (JMC) is a rare autosomal dominant disorder caused by activating mutations in the PTH 1 receptor (PTH1R; PTH/PTHrP receptor), leading to chronic hypercalcemia and hypercalciuria. Hypophosphatemia is also a hallmark of JMC, and recently, increased fibroblast growth factor 23 (FGF23) levels have been reported in this syndrome. Hypercalcemia has been associated with increased cardiovascular risk; however, cardiovascular disease has not been extensively investigated in JMC patients. OBJECTIVE: The aim of the study was to describe the long-term follow-up of a JMC patient with regard to the management of hypercalciuria, the evaluation of FGF23 levels under bisphosphonate treatment, and the investigation of cardiovascular repercussion of chronic hypercalcemia. RESULTS: The diagnosis of JCM was confirmed by molecular analysis (p.H223R mutation in PTH1R). The patient was followed from 5 to 27 yr of age. Asymptomatic nephrolithiasis was diagnosed at 18 yr of age, prompting pharmacological management of hypercalciuria. Treatment with alendronate reduced hypercalciuria; however, normocalciuria was only obtained with the association of thiazide diuretic. Serum FGF23 levels, measured under alendronate treatment, were repeatedly within the normal range. Subclinical cardiovascular disease was investigated when the patient was 26 yr old, after 19 yr of sustained mild hypercalcemia; carotid and vertebral artery ultrasonography was normal, as well as coronary computed tomography angiography (calcium score = 0). CONCLUSION: The long-term follow-up of our JMC patient has provided insight on therapeutic strategies to control hypercalciuria, on the potential effects of alendronate on FGF23 levels, and on the lack of detectable cardiovascular disease at young adulthood after prolonged exposure to hypercalcemia.
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Alendronato/uso terapêutico , Conservadores da Densidade Óssea/uso terapêutico , Fatores de Crescimento de Fibroblastos/sangue , Hipercalciúria/sangue , Hipercalciúria/tratamento farmacológico , Osteocondrodisplasias/fisiopatologia , Adulto , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Quimioterapia Combinada , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Hipercalcemia/etiologia , Hipercalcemia/fisiopatologia , Hipercalcemia/prevenção & controle , Hipercalciúria/etiologia , Índice de Gravidade de Doença , Inibidores de Simportadores de Cloreto de Sódio/uso terapêutico , Resultado do TratamentoRESUMO
CONTEXT: Steroidogenic factor-1 (SF-1, NR5A1, Ad4BP) is a master regulator of adrenal development and steroidogenesis. Defects in several known targets of SF-1 can cause adrenal disorders in humans. OBJECTIVE: We aimed to identify novel targets of SF-1 in the human adrenal. These factors could be important regulators of adrenal development and steroidogenesis and potential candidates for adrenal dysfunction. DESIGN: A gene discovery strategy was developed based on bidirectional manipulation of SF-1. Overexpression or knockdown of SF-1 in NCI-H295R human adrenocortical cells was used to identify a subset of positively-regulated SF-1 targets. RESULTS: This approach identified well-established SF-1 target genes (STAR, CYP11A) and several novel genes (VSNL1, ZIM2, PEG3, SOAT1, and MTSS1). Given its role in cholesterol metabolism, sterol O-acyltransferase 1 (SOAT1, previously referred to as acyl-Coenzyme A:cholesterol acyltransferase 1, ACAT) was studied further and found to be expressed in the developing human fetal adrenal cortex. We hypothesized that impaired SOAT1 activity could result in adrenal insufficiency through reduced cholesteryl ester reserves or through toxic destruction of the adrenal cells during development. Therefore, mutational analysis of SOAT1 in a cohort of 43 patients with unexplained adrenal insufficiency was performed but failed to reveal significant coding sequence changes. CONCLUSIONS: Our reverse discovery approach led to the identification of novel SF-1 targets and defined SOAT1 as an important factor in human adrenal steroidogenesis. SF-1-dependent up-regulation of SOAT1 may be important for maintaining readily-releasable cholesterol reserves needed for active steroidogenesis and during episodes of recurrent stress.
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Glândulas Suprarrenais/metabolismo , Regulação Enzimológica da Expressão Gênica , Fator Esteroidogênico 1/fisiologia , Esterol O-Aciltransferase/genética , Glândulas Suprarrenais/embriologia , Células Cultivadas , Colesterol/metabolismo , Análise por Conglomerados , Embrião de Mamíferos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Análise em Microsséries , Modelos Biológicos , RNA Interferente Pequeno/farmacologia , Fator Esteroidogênico 1/antagonistas & inibidores , Fator Esteroidogênico 1/metabolismo , Esteroides/biossíntese , Esterol O-Aciltransferase/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologiaRESUMO
Steroidogenic factor-1 (SF-1, Ad4BP, encoded by NR5A1) is a key regulator of adrenal and reproductive development and function. Based upon the features found in Nr5a1 null mice, initial attempts to identify SF-1 changes in humans focused on those rare individuals with primary adrenal failure, a 46,XY karyotype, complete gonadal dysgenesis and Müllerian structures. Although alterations affecting DNA-binding of SF-1 were found in two such cases, disruption of SF-1 is not commonly found in patients with adrenal failure. In contrast, it is emerging that variations in SF-1 can be found in association with a range of human reproductive phenotypes such as 46,XY disorders of sex development (DSD), hypospadias, anorchia, male factor infertility, or primary ovarian insufficiency in women. Overexpression or overactivity of SF-1 is also reported in some adrenal tumors or endometriosis. Therefore, the clinical spectrum of phenotypes associated with variations in SF-1 is expanding and the importance of this nuclear receptor in human endocrine disease is now firmly established.
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Doença/genética , Fator Esteroidogênico 1/genética , Animais , Humanos , Fenótipo , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
The nuclear receptor steroidogenic factor-1 (SF-1, NR5A1) is a key regulator of adrenal and gonadal biology. Disruption of SF-1 can lead to disorders of adrenal development, while increased SF-1 dosage has been associated with adrenocortical tumorigenesis. We aimed to identify a novel subset of SF-1 target genes in the adrenal by using chromatin immunoprecipitation (ChIP) microarrays (ChIP-on-chip) combined with systems analysis. SF-1 ChIP-on-chip was performed in NCI-H295R human adrenocortical cells using promoter tiling arrays, leading to the identification of 445 gene loci where SF-1-binding regions were located from 10 kb upstream to 3 kb downstream of a transcriptional start. Network analysis of genes identified as putative SF-1 targets revealed enrichment for angiogenic process networks. A 1.1-kb SF-1-binding region was identified in the angiopoietin 2 (Ang2, ANGPT2) promoter in a highly repetitive region, and SF-1-dependent activation was confirmed in luciferase assays. Angiogenesis is paramount in adrenal development and tumorigenesis, but until now a direct link between SF-1 and vascular remodeling has not been established. We have identified Ang2 as a potentially important novel target of SF-1 in the adrenal gland, indicating that regulation of angiogenesis might be an important additional mechanism by which SF-1 exerts its actions in the adrenal gland.
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Glândulas Suprarrenais/metabolismo , Angiopoietina-2/genética , Fator Esteroidogênico 1/fisiologia , Adenocarcinoma , Neoplasias das Glândulas Suprarrenais , Glândulas Suprarrenais/embriologia , Sítios de Ligação/fisiologia , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Repressoras/metabolismo , Transativadores/metabolismoRESUMO
CONTEXT: Disorders of adrenal development result in significant morbidity and mortality. However, the molecular basis of human adrenal development, and many forms of disease, is still poorly understood. OBJECTIVES: We evaluated the role of two new candidate genes, CBP/p300-interacting transactivator, with Glu/Asp-rich C-terminal domain, 2 (CITED2), and pre-B-cell leukemia transcription factor 1 (PBX1), in human adrenal development and disease. DESIGN: CITED2 and PBX1 expression in early human fetal adrenal development was assessed using RT-PCR and in situ hybridization. The regulation of CITED2 and PBX1 by steroidogenic factor-1 (SF-1) and dosage-sensitive sex reversal, adrenal hypoplasia congenital, critical region on the X chromosome, gene-1 (DAX1) was evaluated in NCI-H295R human adrenocortical tumor cells by studying promoter regulation. Finally, mutational analysis of CITED2 and PBX1 was performed in patients with primary adrenal disorders. RESULTS: CITED2 and PBX1 are expressed in the human fetal adrenal gland during early development. Both genes are activated by SF-1 in a dose-dependent manner in NCI-H295R cells, and, surprisingly, PBX1 is synergistically activated by SF-1 and DAX1. Mutational analysis failed to reveal significant coding sequence changes in individuals with primary adrenal disorders. CONCLUSIONS: CITED2 and PBX1 are likely to be important mediators of adrenal development and function in humans, but mutations in these genes are not common causes of adrenal failure in patients in whom a molecular diagnosis remains unknown. The positive interaction between DAX1 and SF-1 in regulating PBX1 may be an important mechanism in this process.
Assuntos
Doenças das Glândulas Suprarrenais/genética , Glândulas Suprarrenais/embriologia , Proteínas de Ligação a DNA/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Proteínas Repressoras/fisiologia , Transativadores/fisiologia , Doenças das Glândulas Suprarrenais/patologia , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Células Cultivadas , Receptor Nuclear Órfão DAX-1 , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Mutação/fisiologia , Fator de Transcrição 1 de Leucemia de Células Pré-B , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Receptores do Ácido Retinoico/metabolismo , Receptores do Ácido Retinoico/fisiologia , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fator Esteroidogênico 1/metabolismo , Fator Esteroidogênico 1/fisiologia , Transativadores/genética , Transativadores/metabolismo , TransfecçãoRESUMO
The past decade has seen significant advances in our understanding of the genetic aetiology of several forms of adrenal failure that present in infancy or childhood. Several of these disorders affect adrenal development and are termed 'adrenal hypoplasia'. These conditions can be broadly divided into: (1) secondary forms of adrenal hypoplasia due to panhypopituitarism (e.g. HESX1, LHX4, SOX3) or abnormalities in ACTH synthesis (TPIT) or processing (e.g. POMC or PC1); (2) adrenal hypoplasia as part of an ACTH resistance syndrome [MC2R/ACTH receptor, MRAP, AAAS (triple A syndrome)], and (3) primary defects in the development of the adrenal gland itself (primary adrenal hypoplasia). Primary adrenal hypoplasia most commonly occurs in an X-linked form due to mutations in the nuclear receptor DAX1 (NR0B1) but can occur in a poorly understood recessive form or as part of the IMAGe (intrauterine growth retardation, metaphyseal dysplasia, adrenal hypoplasia, genitourinary anomalies) syndrome. Defining the molecular basis of these conditions can have significant clinical implications for management, counselling and presymptomatic diagnosis, as well as providing fascinating insight into normal and abnormal mechanisms of adrenal development in humans.