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1.
J Clin Endocrinol Metab ; 107(7): e2938-e2951, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35312002

RESUMO

CONTEXT: Adrenocorticotropin (ACTH)-secreting pituitary tumors (ACTHomas) are associated with severe comorbidities and increased mortality. Current treatments mainly focus on remission and prevention of persistent disease and recurrence. However, there are still no useful biomarkers to accurately predict the clinical outcome after surgery, long-term remission, or disease relapse. OBJECTIVES: This work aimed to identify clinical, biochemical, and molecular markers for predicting long-term clinical outcome and remission in ACTHomas. METHODS: A retrospective multicenter study was performed with 60 ACTHomas patients diagnosed between 2004 and 2018 with at least 2 years' follow-up. Clinical/biochemical variables were evaluated yearly. Molecular expression profile of the somatostatin/ghrelin/dopamine regulatory systems components and of key pituitary factors and proliferation markers were evaluated in tumor samples after the first surgery. RESULTS: Clinical variables including tumor size, time until diagnosis/first surgery, serum prolactin, and postsurgery cortisol levels were associated with tumor remission and relapsed disease. The molecular markers analyzed were distinctly expressed in ACTHomas, with some components (ie, SSTR1, CRHR1, and MKI67) showing instructive associations with recurrence and/or remission. Notably, an integrative model including selected clinical variables (tumor size/postsurgery serum cortisol), and molecular markers (SSTR1/CRHR1) can accurately predict the clinical evolution and remission of patients with ACTHomas, generating a receiver operating characteristic curve with an area under the curve of 1 (P < .001). CONCLUSION: This study demonstrates that the combination of a set of clinical and molecular biomarkers in ACTHomas is able to accurately predict the clinical evolution and remission of patients. Consequently, the postsurgery molecular profile represents a valuable tool for clinical evaluation and follow-up of patients with ACTHomas.


Assuntos
Hipersecreção Hipofisária de ACTH , Doenças da Hipófise , Neoplasias Hipofisárias , Humanos , Hidrocortisona , Hipersecreção Hipofisária de ACTH/diagnóstico , Hipersecreção Hipofisária de ACTH/genética , Hipersecreção Hipofisária de ACTH/cirurgia , Hipófise/patologia , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/cirurgia , Recidiva , Indução de Remissão , Estudos Retrospectivos , Resultado do Tratamento
2.
J Clin Med ; 11(1)2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35012020

RESUMO

Craniopharyngiomas (CPs) are rare tumors of the sellar and suprasellar regions of embryonic origin. The primary treatment for CPs is surgery but it is often unsuccessful. Although CPs are considered benign tumors, they display a relatively high recurrence rate that might compromise quality of life. Previous studies have reported that CPs express sex hormone receptors, including estrogen and progesterone receptors. Here, we systematically analyzed estrogen receptor α (ERα) and progesterone receptor (PR) expression by immunohistochemistry in a well-characterized series of patients with CP (n = 41) and analyzed their potential association with tumor aggressiveness features. A substantial proportion of CPs displayed a marked expression of PR. However, most CPs expressed low levels of ERα. No major association between PR and ERα expression and clinical aggressiveness features was observed in CPs. Additionally, in our series, ß-catenin accumulation was not related to tumor recurrence.

3.
J Clin Med ; 9(9)2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32971845

RESUMO

The primary treatment for non-functioning pituitary tumors (NFPTs) is surgery, but it is often unsuccessful. Previous studies have reported that NFPTs express receptors for somatostatin (SST1-5) and dopamine (DRDs) providing a rationale for the use of dopamine agonists and somatostatin analogues. Here, we systematically assessed SST1-5 and DRDs expression by real-time quantitative PCR (RT-qPCR) in a large group of patients with NFPTs (n = 113) and analyzed their potential association with clinical and molecular aggressiveness features. SST1-5 expression was also evaluated by immunohistochemistry. SST3 was the predominant SST subtype detected, followed by SST2, SST5, and SST1. DRD2 was the dominant DRD subtype, followed by DRD4, DRD5, and DRD1. A substantial proportion of NFPTs displayed marked expression of SST2 and SST5. No major association between SSTs and DRDs expression and clinical and molecular aggressiveness features was observed in NFPTs.

4.
Acta Physiol (Oxf) ; 229(2): e13293, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31059193

RESUMO

AIM: Besides their metabolic and endocrine functions, the growth hormone (GH) and its mediated factor, the insulin-like growth factor I (IGF-I), have been implicated in different brain functions, including neurogenesis. Long-lasting elevated GH and IGF-I levels result in non-reversible somatic, endocrine and metabolic morbidities. However, the subcutaneous implantation of the GH-secreting (GH-S) GC cell line in rats leads to the controllable over-secretion of GH and elevated IGF-I levels, allowing the experimental study of their short-term effects on brain functions. METHODS: Adult rats were implanted with GC cells and checked 10 weeks later, when a GH/IGF-I-secreting tumour was already formed. RESULTS: Tumour-bearing rats acquired different operant conditioning tasks faster and better than controls and tumour-resected groups. They also presented better retentions of long-term memories in the passive avoidance test. Experimentally evoked long-term potentiation (LTP) in the hippocampus was also larger and longer lasting in the tumour bearing than in the other groups. Chronic adult-onset of GH/IGF-I hypersecretion caused an acceleration of early progenitors, facilitating a faster neural differentiation, maturation and integration in the dentate gyrus, and increased the complexity of dendritic arbours and spine density of granule neurons. CONCLUSION: Thus, adult-onset hypersecretion of GH/IGF-I improves neurocognitive functions, long-term memories, experimental LTP and neural differentiation, migration and maturation.


Assuntos
Diferenciação Celular , Cognição , Hormônio do Crescimento/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Potenciação de Longa Duração , Neurônios/citologia , Animais , Feminino , Ratos , Ratos Endogâmicos WF
5.
IUBMB Life ; 72(1): 80-88, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31580534

RESUMO

There is an urgent need for the development of novel therapeutics options for diabetic patients given the high prevalence of diabetes worldwide and that, currently, there is no cure for this disease. The transplantation of pancreatic islets that contain insulin-producing cells is a promising therapeutic alternative, particularly for type 1 diabetes. However, the shortage of organ donors constitutes a major limitation for this approach; thus, developing alternative sources of insulin-producing cells is of critical importance. In the last decade, our knowledge of the molecular mechanisms controlling embryonic pancreas development has significantly advanced. More importantly, this knowledge has provided the basis for the in vitro generation of insulin-producing cells from stem cells. Recent studies have revealed that GATA transcription factors are involved in various stages of pancreas formation and in the adult ß cell function. Here, we review the fundamental role of GATA transcription factors in pancreas morphogenesis and their association with congenital diseases associated with pancreas.


Assuntos
Fatores de Transcrição GATA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Pâncreas/embriologia , Pancreatopatias/patologia , Animais , Fatores de Transcrição GATA/genética , Humanos , Pâncreas/metabolismo , Pancreatopatias/genética , Pancreatopatias/metabolismo , Transdução de Sinais
6.
Clin Cancer Res ; 26(4): 957-969, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31624102

RESUMO

PURPOSE: Somatostatin analogues (SSA) are efficacious and safe treatments for a variety of neuroendocrine tumors, especially pituitary neuroendocrine tumors (PitNET). Their therapeutic effects are mainly mediated by somatostatin receptors SST2 and SST5. Most SSAs, such as octreotide/lanreotide/pasireotide, are either nonselective or activate mainly SST2. However, nonfunctioning pituitary tumors (NFPTs), the most common PitNET type, mainly express SST3 and finding peptides that activate this particular somatostatin receptor has been very challenging. Therefore, the main objective of this study was to identify SST3-agonists and characterize their effects on experimental NFPT models. EXPERIMENTAL DESIGN: Binding to SSTs and cAMP level determinations were used to screen a peptide library and identify SST3-agonists. Key functional parameters (cell viability/caspase activity/chromogranin-A secretion/mRNA expression/intracellular signaling pathways) were assessed on NFPT primary cell cultures in response to SST3-agonists. Tumor growth was assessed in a preclinical PitNET mouse model treated with a SST3-agonist. RESULTS: We successfully identified the first SST3-agonist peptides. SST3-agonists lowered cell viability and chromogranin-A secretion, increased apoptosis in vitro, and reduced tumor growth in a preclinical PitNET model. As expected, inhibition of cell viability in response to SST3-agonists defined two NFPT populations: responsive and unresponsive, wherein responsive NFPTs expressed more SST3 than unresponsive NFPTs and exhibited a profound reduction of MAPK, PI3K-AKT/mTOR, and JAK/STAT signaling pathways upon SST3-agonist treatments. Concurrently, SSTR3 silencing increased cell viability in a subset of NFPTs. CONCLUSIONS: This study demonstrates that SST3-agonists activate signaling mechanisms that reduce NFPT cell viability and inhibit pituitary tumor growth in experimental models that expresses SST3, suggesting that targeting this receptor could be an efficacious treatment for NFPTs.


Assuntos
Tumores Neuroendócrinos/tratamento farmacológico , Peptídeos/farmacologia , Neoplasias Hipofisárias/tratamento farmacológico , Receptores de Somatostatina/agonistas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Janus Quinases/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/patologia , Peptídeos/química , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Transdução de Sinais , Células Tumorais Cultivadas , Adulto Jovem
7.
J Pathol ; 250(4): 362-373, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31875961

RESUMO

Pancreatic heterotopia is defined as pancreatic tissue outside its normal location in the body and anatomically separated from the pancreas. In this work we have analyzed the stomach glandular epithelium of Gata4 flox/flox ; Pdx1-Cre mice (Gata4KO mice). We found that Gata4KO glandular epithelium displays an atypical morphology similar to the cornified squamous epithelium and exhibits upregulation of forestomach markers. The developing gastric units fail to form properly, and the glandular epithelial cells do not express markers of gastric gland in the absence of GATA4. Of interest, the developing glands of the Gata4KO stomach express pancreatic cell markers. Furthermore, a mass of pancreatic tissue located in the subserosa of the Gata4KO stomach is observed at adult stages. Heterotopic pancreas found in Gata4-deficient mice contains all three pancreatic cell lineages: ductal, acinar, and endocrine. Moreover, Gata4 expression is downregulated in ectopic pancreatic tissue of some human biopsy samples. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Células Epiteliais/patologia , Fator de Transcrição GATA4/genética , Pâncreas/patologia , Animais , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Mucosa Gástrica/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Camundongos Transgênicos , Organogênese/fisiologia
8.
World Neurosurg ; 130: e634-e639, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31276853

RESUMO

OBJECTIVE: Thyrotropin (TSH)-secreting pituitary tumors are rare and typically present with hyperthyroidism. Here we report the diagnosis, treatment, and surgical outcomes in a series of patients with TSH-secreting pituitary tumors in a tertiary referral center. METHODS: Descriptive retrospective study that included all patients with TSH-secreting pituitary tumors who underwent transsphenoidal surgery in the endocrinology and nutrition unit of the Virgen del Rocío University Hospital (Seville, Spain) between 2004 and 2016. RESULTS: The mean age at diagnosis was 42.8 ± 17 years. The mean time from onset of symptoms to diagnosis was 13 ± 10 months. Four patients displayed symptoms indicating hyperthyroidism (1 suffered from tachycardia); 3 patients showed symptoms because of mass effect (visual impairment and headache) and 3 patients were diagnosed based on incidental findings after routine blood tests (high free thyroxine levels). Eight patients had macroadenomas, and 2 patients had microadenomas. Five patients underwent conventional pituitary surgery, and 5 patients underwent expanded endoscopic transsphenoidal surgery. Six patients achieved cure after surgery. The other patients received radiotherapy and/or treatment with somatostatin analogs. Analysis of somatostatin receptor (SSTR) expression by immunohistochemistry could be performed in 6 tumors. CONCLUSIONS: Our results confirm the clinical and hormonal heterogeneity caused by TSH-secreting pituitary adenomas. Surgery is considered the first choice of treatment for these tumors. We observed surgical cure rates similar to those reported in recent published series. SSTR2 and SSTR3 are highly expressed in TSH-secreting pituitary adenomas. Our results suggest that somatostatin analog treatment may be also helpful in the treatment of TSH-secreting pituitary adenomas.


Assuntos
Adenoma/cirurgia , Hipertireoidismo/cirurgia , Procedimentos Neurocirúrgicos/métodos , Neoplasias Hipofisárias/cirurgia , Tireotrofos/patologia , Tireotropina/metabolismo , Adenoma/complicações , Adenoma/metabolismo , Adenoma/patologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Hipertireoidismo/etiologia , Hipertireoidismo/metabolismo , Hipertireoidismo/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Estudos Retrospectivos , Centros de Atenção Terciária , Resultado do Tratamento , Adulto Jovem
9.
World Neurosurg ; 122: e436-e442, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-31108069

RESUMO

OBJECTIVE: Cushing disease (CD) is a rare, poorly understood entity. Our aim was to add our clinical experience of >30 years in a multidisciplinary specialized unit to the global knowledge of CD. METHODS: This descriptive retrospective study included all patients admitted to the Endocrinology and Nutrition Department of the Virgen del Rocío University Hospital, Seville, Spain, from January 1980 to May 2016. All patients had a definitive diagnosis of CD. RESULTS: Total sample included 119 patients; 100 (84%) were female. Median age at diagnosis was 37.97 years (interquartile range [IQR]: 25.89-45.07 years). Median follow-up was 88 months (IQR: 45.50-157.00 months). Most tumors were microadenomas (62/95) (5.1 mm [IQR: 4.0-7.0 mm]) without sinus invasion. Surgical procedures were conventional transsphenoidal surgery (CTSS) (101/108; cured 70 after first attempt) and expanded endoscopic transsphenoidal surgery (EETSS) (7/108; cured 5 after first attempt); 11 patients did not receive surgical treatment. Fourteen patients received radiotherapy after a first surgery and 5 patients after a second surgical removal attempt. In 13 patients (12.04%), CD relapse was demonstrated after initial CTSS (median disease-free period 65 months [IQR: 45-120 months]). Ten patients developed panhypopituitarism owing to the surgical procedure (CTSS); 8 patients developed panhypopituitarism after adjuvant radiotherapy. CONCLUSIONS: We observed slightly inferior cure rate after first surgery compared with moderately better relapse rates and time to relapse. Radiotherapy after surgery failure seemed to be more effective than CTSS; however, EETSS may be a valid alternative. Postoperative panhypopituitarism rate after first surgery was lower than expected; after radiotherapy, our results were comparable to other series.


Assuntos
Endoscopia/métodos , Hipersecreção Hipofisária de ACTH/cirurgia , Adenoma Hipofisário Secretor de ACT/complicações , Adenoma Hipofisário Secretor de ACT/cirurgia , Adenoma/complicações , Adenoma/cirurgia , Adulto , Feminino , Humanos , Hipopituitarismo/etiologia , Masculino , Pessoa de Meia-Idade , Hipersecreção Hipofisária de ACTH/radioterapia , Complicações Pós-Operatórias/etiologia , Radioterapia Adjuvante/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento
10.
J Cell Mol Med ; 23(5): 3088-3096, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30843342

RESUMO

Acromegaly is a rare disease resulting from hypersecretion of growth hormone (GH) and insulin-like growth factor 1 (IGF1) typically caused by pituitary adenomas, which is associated with increased mortality and morbidity. Somatostatin analogues (SSAs) represent the primary medical therapy for acromegaly and are currently used as first-line treatment or as second-line therapy after unsuccessful pituitary surgery. However, a considerable proportion of patients do not adequately respond to SSAs treatment, and therefore, there is an urgent need to identify biomarkers predictors of response to SSAs. The aim of this study was to examine E-cadherin expression by immunohistochemistry in fifty-five GH-producing pituitary tumours and determine the potential association with response to SSAs as well as other clinical and histopathological features. Acromegaly patients with tumours expressing low E-cadherin levels exhibit a worse response to SSAs. E-cadherin levels are associated with GH-producing tumour histological subtypes. Our results indicate that the immunohistochemical detection of E-cadherin might be useful in categorizing acromegaly patients based on the response to SSAs.


Assuntos
Acromegalia/tratamento farmacológico , Caderinas/genética , Neoplasias Hipofisárias/tratamento farmacológico , Somatostatina/administração & dosagem , Acromegalia/genética , Acromegalia/patologia , Adulto , Biomarcadores/metabolismo , Biomarcadores Farmacológicos/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônio do Crescimento/genética , Humanos , Fator de Crescimento Insulin-Like I/genética , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/cirurgia , Receptores de Somatostatina/genética , Somatostatina/análogos & derivados
11.
Endocr Connect ; 8(4): 338-348, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30822274

RESUMO

BACKGROUND: Pituitary adenomas have a high disease burden due to tumor growth/invasion and disordered hormonal secretion. Germline mutations in genes such as MEN1 and AIP are associated with early onset of aggressive pituitary adenomas that can be resistant to medical therapy. AIMS: We performed a retrospective screening study using published risk criteria to assess the frequency of AIP and MEN1 mutations in pituitary adenoma patients in a tertiary referral center. METHODS: Pituitary adenoma patients with pediatric/adolescent onset, macroadenomas occurring ≤30 years of age, familial isolated pituitary adenoma (FIPA) kindreds and acromegaly or prolactinoma cases that were uncontrolled by medical therapy were studied genetically. We also assessed whether immunohistochemical staining for AIP (AIP-IHC) in somatotropinomas was associated with somatostatin analogs (SSA) response. RESULTS: Fifty-five patients met the study criteria and underwent genetic screening for AIP/MEN1 mutations. No mutations were identified and large deletions/duplications were ruled out using MLPA. In a cohort of sporadic somatotropinomas, low AIP-IHC tumors were significantly larger (P = 0.002) and were more frequently sparsely granulated (P = 0.046) than high AIP-IHC tumors. No significant relationship between AIP-IHC and SSA responses was seen. CONCLUSIONS: Germline mutations in AIP/MEN1 in pituitary adenoma patients are rare and the use of general risk criteria did not identify cases in a large tertiary-referral setting. In acromegaly, low AIP-IHC was related to larger tumor size and more frequent sparsely granulated subtype but no relationship with SSA responsiveness was seen. The genetics of pituitary adenomas remains largely unexplained and AIP screening criteria could be significantly refined to focus on large, aggressive tumors in young patients.

12.
Sci Rep ; 8(1): 13713, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30209343

RESUMO

Hypoxia inducible factors (HIFs) are critical regulators of the response to oxygen deficiency by activating target genes involved in a variety of biological functions. HIFs have been implicated in the pathophysiology of numerous pathologies including cancer. Patients with mutations in the von Hippel-Lindau (VHL) gene, an essential regulator of HIF activity, develop tumors in several organs including the pancreas. Previous functional studies of HIF activation in the pancreas have used Vhlh (the murine homolog of VHL) deficient mice. However, the role of each specific HIF transcription factors in the pancreas has not been thoroughly examined. We derived mice that constitutively express a normoxia-stable form of HIF2α in the pancreas. Activation of HIF2α in the pancreas severely impairs postnatal exocrine pancreas. Mice with pancreas-specific activation of HIF2α develop histological features reminiscent of pancreatitis including loss of acinar cells, ductal dilation and fibrosis. Moreover, we provide evidence that signaling pathways important for acinar cell homeostasis are altered in HIF2α-overexpressing pancreata.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proliferação de Células/genética , Pâncreas/patologia , Animais , Fibrose/genética , Fibrose/patologia , Regulação Neoplásica da Expressão Gênica/genética , Homeostase/genética , Camundongos , Transdução de Sinais/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética
13.
J Cell Mol Med ; 22(3): 1640-1649, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29266696

RESUMO

Acromegaly is a hormonal disorder resulting from excessive growth hormone (GH) secretion frequently produced by pituitary adenomas and consequent increase in insulin-like growth factor 1 (IGF-I). Elevated GH and IGF-I levels result in a wide range of somatic, cardiovascular, endocrine, metabolic and gastrointestinal morbidities. Somatostatin analogues (SSAs) form the basis of medical therapy for acromegaly and are currently used as first-line treatment or as second-line therapy in patients undergoing unsuccessful surgery. However, a considerable percentage of patients do not respond to SSAs treatment. Somatostatin receptors (SSTR1-5) and dopamine receptors (DRD1-5) subtypes play critical roles in the regulation of hormone secretion. These receptors are considered important pharmacological targets to inhibit hormone oversecretion. It has been proposed that decreased expression of SSTRs may be associated with poor response to SSAs. Here, we systematically examine SSTRs and DRDs expression in human somatotroph adenomas by quantitative PCR. We observed an association between the response to SSAs treatment and DRD4, DRD5, SSTR1 and SSTR2 expression. We also examined SSTR expression by immunohistochemistry and found that the immunohistochemical detection of SSTR2 in particular might be a good predictor of response to SSAs.


Assuntos
Adenoma/genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/genética , Receptores Dopaminérgicos/genética , Receptores de Somatostatina/genética , Somatostatina/farmacologia , Adenoma/tratamento farmacológico , Adenoma/metabolismo , Adulto , Feminino , Expressão Gênica/efeitos dos fármacos , Adenoma Hipofisário Secretor de Hormônio do Crescimento/tratamento farmacológico , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores de Somatostatina/metabolismo , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Obes Surg ; 26(8): 1757-67, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26678755

RESUMO

BACKGROUND: Adipose tissue (AT) dysfunction in obesity is commonly linked to insulin resistance and promotes the development of metabolic disease. Bariatric surgery (BS) represents an effective strategy to reduce weight and to improve metabolic health in morbidly obese subjects. However, the mechanisms and pathways that are modified in AT in response to BS are not fully understood, and few information is still available as to whether these may vary depending on the metabolic status of obese subjects. METHODS: Abdominal subcutaneous adipose tissue (SAT) samples were obtained from morbidly obese women (n = 18) before and 13.3 ± 0.37 months after BS. Obese women were stratified into two groups: normoglycemic (NG; Glu < 100 mg/dl, HbA1c <5.7 %) or insulin resistant (IR; Glu 100-126 mg/dl, HbA1c 5.7-6.4 %) (n = 9/group). A multi-comparative proteomic analysis was employed to identify differentially regulated SAT proteins by BS and/or the degree of insulin sensitivity. Serum levels of metabolic, inflammatory, and anti-oxidant markers were also analyzed. RESULTS: Before surgery, NG and IR subjects exhibited differences in AT proteins related to inflammation, metabolic processes, the cytoskeleton, and mitochondria. BS caused comparable weight reductions and improved glucose homeostasis in both groups. However, BS caused dissimilar changes in metabolic enzymes, inflammatory markers, cytoskeletal components, mitochondrial proteins, and angiogenesis regulators in NG and IR women. CONCLUSIONS: BS evokes significant molecular rearrangements indicative of improved AT function in morbidly obese women at either low or high metabolic risk, though selective adaptive changes in key cellular processes occur depending on the initial individual's metabolic status.


Assuntos
Biomarcadores/metabolismo , Resistência à Insulina , Síndrome Metabólica/metabolismo , Obesidade Mórbida/cirurgia , Gordura Subcutânea Abdominal/metabolismo , Redução de Peso , Adulto , Cirurgia Bariátrica , Feminino , Humanos , Obesidade Mórbida/metabolismo , Saúde da Mulher
16.
Sci Rep ; 5: 16298, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26549306

RESUMO

Acromegaly is a disorder resulting from excessive production of growth hormone (GH) and consequent increase of insulin-like growth factor 1 (IGF-I), most frequently caused by pituitary adenomas. Elevated GH and IGF-I levels results in wide range of somatic, cardiovascular, endocrine, metabolic, and gastrointestinal morbidities. Subcutaneous implantation of the GH-secreting GC cell line in rats leads to the formation of tumors. GC tumor-bearing rats develop characteristics that resemble human acromegaly including gigantism and visceromegaly. However, GC tumors remain poorly characterized at a molecular level. In the present work, we report a detailed histological and molecular characterization of GC tumors using immunohistochemistry, molecular biology and imaging techniques. GC tumors display histopathological and molecular features of human GH-producing tumors, including hormone production, cell architecture, senescence activation and alterations in cell cycle gene expression. Furthermore, GC tumors cells displayed sensitivity to somatostatin analogues, drugs that are currently used in the treatment of human GH-producing adenomas, thus supporting the GC tumor model as a translational tool to evaluate therapeutic agents. The information obtained would help to maximize the usefulness of the GC rat model for research and preclinical studies in GH-secreting tumors.


Assuntos
Acromegalia/etiologia , Acromegalia/metabolismo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/complicações , Adenoma Hipofisário Secretor de Hormônio do Crescimento/genética , Hormônio do Crescimento/metabolismo , Acromegalia/diagnóstico , Acromegalia/cirurgia , Animais , Ciclo Celular/genética , Senescência Celular/genética , Modelos Animais de Doenças , Feminino , Fluordesoxiglucose F18 , Perfilação da Expressão Gênica , Adenoma Hipofisário Secretor de Hormônio do Crescimento/diagnóstico , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/cirurgia , Fenótipo , Tomografia por Emissão de Pósitrons , Ratos , Tomografia Computadorizada por Raios X , Células Tumorais Cultivadas
17.
Front Oncol ; 4: 203, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25136513

RESUMO

Animal models constitute valuable tools for investigating the pathogenesis of cancer as well as for preclinical testing of novel therapeutics approaches. However, the pathogenic mechanisms of pituitary-tumor formation remain poorly understood, particularly in sporadic adenomas, thus, making it a challenge to model pituitary tumors in mice. Nevertheless, genetically engineered mouse models (GEMMs) of pituitary tumors have provided important insight into pituitary tumor biology. In this paper, we review various GEMMs of pituitary tumors, highlighting their contributions and limitations, and discuss opportunities for research in the field.

18.
Endocrinol Nutr ; 61(2): 69-76, 2014 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-24183946

RESUMO

OBJECTIVE: To assess the utility of the desmopressin (DDAVP) test in the diagnosis and follow-up of a cyclical Cushing's disease (CCS) case. MATERIAL AND METHODS: Laboratory tests included morning and midnight serum cortisol levels, 24h urine free cortisol excretion, midnight salivary cortisol levels, serum cortisol levels after low (1 mg) and high (8 mg) dexamethasone, plasma ACTH and serum cortisol levels after DDAVP. Magnetic resonance imaging (MRI) was used to assess the presence of a pituitary adenoma. The resected tumor specimen was studied by histological, immunohistochemical and cell biology techniques. RESULTS: A patient was referred to our unit with a diagnosis of Cushing's syndrome (CS) for further evaluation and treatment. However, no biochemical evidence of hypercortisolism was observed in the follow-up evaluations. Furthermore, the typical features of CS fluctuated throughout this period. A consistent positive response to the DDAVP stimulation test was observed during the diagnostic work-up, even when overt clinical features of CS were not apparent, raising suspicion for CCS. After two years of follow-up a definitive diagnosis of hypercortisolism was established. An MRI scan revealed a pituitary adenoma, as the source of ACTH production. After transphenoidal surgery, clinical signs of CS resolved and the response to DDAVP became negative. DDAVP induced a significant increase in ACTH levels in cultured pituitary adenoma cells, consistent with the in vivo DDAVP test results. CONCLUSIONS: Our case illustrates the utility of the DDAVP test in the evaluation of patients with suspected CCS. The DDAVP test could facilitate the management of CCS by shortening the time of diagnosis.


Assuntos
Adenoma Hipofisário Secretor de ACT/complicações , Desamino Arginina Vasopressina , Periodicidade , Hipersecreção Hipofisária de ACTH/diagnóstico , Neoplasias Hipofisárias/complicações , Adenoma Hipofisário Secretor de ACT/diagnóstico , Adenoma Hipofisário Secretor de ACT/genética , Adenoma Hipofisário Secretor de ACT/cirurgia , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Ritmo Circadiano , Desamino Arginina Vasopressina/farmacologia , Feminino , Humanos , Hidrocortisona/análise , Hidrocortisona/metabolismo , Hipofisectomia , Imageamento por Ressonância Magnética , Fenótipo , Hipersecreção Hipofisária de ACTH/sangue , Hipersecreção Hipofisária de ACTH/etiologia , Hipersecreção Hipofisária de ACTH/urina , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/cirurgia , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
19.
PLoS One ; 8(8): e72213, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23977255

RESUMO

Mutations in the human homolog of the Vhlh gene [encoding the von-Hippel Lindau (VHL) protein] lead to tumor development. In mice, depletion of Vhlh in pancreatic ß-cells causes perturbed glucose homeostasis, but the role of this gene in other pancreatic cells is poorly understood. To investigate the function of VHL/HIF pathway in pancreatic cells, we inactivated Vhlh in the pancreatic epithelium as well as in the endocrine and exocrine lineages. Our results show that embryonic depletion of Vhlh within the pancreatic epithelium causes postnatal lethality due to severe hypoglycemia. The hypoglycemia is recapitulated in mice with endocrine-specific removal of Vhlh, while animals with loss of Vhlh predominantly in the exocrine compartment survive to adulthood with no overt defects in glucose metabolism. Mice with hypoglycemia display diminished insulin release in response to elevated glucose. Significantly, the glucagon response is impaired both in vivo (circulating glucagon levels) as well as in an in vitro secretion assay in isolated islets. Hypoxia also impairs glucagon secretion in a glucagon-expressing cell line in culture. Our results reveal a novel role for the hypoxia/HIF pathway in islet hormone secretion and maintenance of the fine balance that allows for the establishment of normoglycemia.


Assuntos
Sistema Endócrino/metabolismo , Células Secretoras de Glucagon/metabolismo , Fator 1 Induzível por Hipóxia/genética , Hipóxia/genética , Células Secretoras de Somatostatina/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Animais , Células Cultivadas , Embrião de Mamíferos , Sistema Endócrino/patologia , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Glucagon/metabolismo , Células Secretoras de Glucagon/patologia , Glucose/metabolismo , Homeostase/genética , Hipóxia/metabolismo , Hipóxia/patologia , Fator 1 Induzível por Hipóxia/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Camundongos , Camundongos Knockout , Células Secretoras de Polipeptídeo Pancreático/metabolismo , Células Secretoras de Polipeptídeo Pancreático/patologia , Transdução de Sinais , Células Secretoras de Somatostatina/patologia , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo
20.
PLoS One ; 8(4): e60041, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23593161

RESUMO

Patients with active untreated acromegaly show mild to moderate neurocognitive disorders that are associated to chronic exposure to growth hormone (GH) and insulin-like growth factor (IGF-I) hypersecretion. However, it is unknown whether these disorders improve after controlling GH/IGF-I hypersecretion. The aim of this study was to compare neurocognitive functions of patients who successfully underwent GH-secreting adenoma transsphenoidal surgery (cured patients) with patients with naive acromegaly. In addition, we wanted to determine the impact of different clinical and biochemical variables on neurocognitive status in patients with active disease and after long-term cure. A battery of six standardized neuropsychological tests assessed attention, memory and executive functioning. In addition, a quantitative electroencephalography with Low-Resolution Electromagnetic Tomography (LORETA) solution was performed to obtain information about the neurophysiological state of the patients. Neurocognitive data was compared to that of a healthy control group. Multiple linear regression analysis was also conducted using clinical and hormonal parameters to obtain a set of independent predictors of neurocognitive state before and after cure. Both groups of patients scored significantly poorer than the healthy controls on memory tests, especially those assessing visual and verbal recall. Patients with cured acromegaly did not obtain better cognitive measures than naïve patients. Furthermore memory deficits were associated with decreased beta activity in left medial temporal cortex in both groups of patients. Regression analysis showed longer duration of untreated acromegaly was associated with more severe neurocognitive complications, regardless of the diagnostic group, whereas GH levels at the time of assessment was related to neurocognitive outcome only in naïve patients. Longer duration of post-operative biochemical remission of acromegaly was associated with better neurocognitive state. Overall, this data suggests that the effects of chronic exposure to GH/IGF-I hypersecretion could have long-term effects on brain functions.


Assuntos
Acromegalia/diagnóstico , Acromegalia/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Hormônio do Crescimento Humano/metabolismo , Neoplasias Hipofisárias/metabolismo , Acromegalia/etiologia , Acromegalia/cirurgia , Adulto , Transtornos Cognitivos/etiologia , Diagnóstico Diferencial , Eletroencefalografia , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/cirurgia , Qualidade de Vida
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