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1.
Surg Today ; 47(12): 1469-1475, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28474203

RESUMO

PURPOSE: To establish the most effective methods of postoperative surveillance to detect early recurrence of lung adenocarcinoma. METHODS: The subjects of this retrospective study were 485 patients with p-stage I-III lung adenocarcinoma, who underwent postoperative surveillance. We examined the sites and detection modes of recurrence and calculated the recurrence-free probabilities. Patients with stage I disease were divided into low- and high-risk recurrence groups using a risk score calculated by assigning points proportional to risk factor regression coefficients. RESULTS: Of the 112 patients with recurrence, 86 had intrathoracic recurrence. Routine computed tomography (CT) revealed recurrence in 60 patients. The recurrence-free probability curves showed that 95% of recurrences were identified within the first 4 years after resection in patients with stage II/III disease. In patients with stage I disease, the predictors of recurrence included male sex, positive pleural lavage cytology, moderate-to-poor differentiation, and visceral pleural invasion. Postoperative recurrences were detected throughout the follow-up period in the high-risk group. CONCLUSIONS: Routine chest CT plays an important role in the postoperative surveillance of lung adenocarcinoma. We recommend intensive follow-up during the early post-resection period for patients with advanced stage disease and long-term follow-up for high-risk patients with stage I disease.


Assuntos
Adenocarcinoma/cirurgia , Neoplasias Pulmonares/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido da Lavagem Broncoalveolar/citologia , Monitoramento Epidemiológico , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/prevenção & controle , Estadiamento de Neoplasias , Pleura/patologia , Período Pós-Operatório , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fatores de Tempo , Tomografia Computadorizada por Raios X
3.
J Gene Med ; 10(3): 290-7, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18074399

RESUMO

BACKGROUND: Although gene therapy using plasmid vectors is thought to be safer compared with viral vectors, poor efficacy of gene transfer is the obstacle preventing wide application of plasmid vectors. However, high levels of foreign gene expression have been achieved by rapid tail vein injection of a large volume of a plasmid DNA solution into rats. Using this technique, we examined the effect of rat CTLA4-Ig gene transfer on prevention of cardiac allograft rejection in this animal model. METHODS: Recipient Lewis rats were injected with either plasmid pCAGGS-CTLA4-Ig-Glu-tag as a treatment vector or plasmid pCAGGS-signal peptide (SP)-Ig as a control vector by hydrodynamics-based delivery technique on the day before heart transplantation. Hearts from Brown Norway donors were transplanted into the neck of Lewis recipients and graft survival was assessed. RESULTS: The plasma level of CTLA4-Ig reached a peak of nearly 5 microg/mL 1 day after injection, and then slowly decreased but still remained above 0.9 microg/mL until 100 days after injection. The recipient rats treated with the control vector and untreated rats rejected cardiac allografts within 7 days. On the other hand, the median survival time of the grafts treated with pCAGGS-CTLA4Ig-Glu-tag was more than 100 days. Histological examination revealed that long-term survival allografts contained fewer infiltrating lymphocytes. The serum from recipients with long-term survival allograft suppressed allogenic mixed lymphocyte reaction. CONCLUSIONS: CTLA4-Ig gene transfer by means of tail vein injection of plasmid DNA into a recipient rat resulted in remarkable prolongation of cardiac allograft survival with persistent plasma level of CTLA4-Ig protein.


Assuntos
Vetores Genéticos/administração & dosagem , Sobrevivência de Enxerto , Transplante de Coração/fisiologia , Imunoconjugados/genética , Plasmídeos/administração & dosagem , Abatacepte , Animais , DNA/administração & dosagem , DNA/metabolismo , Sobrevivência de Enxerto/genética , Masculino , Plasmídeos/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos Lew , Transplante Homólogo
4.
Ann Thorac Cardiovasc Surg ; 13(6): 423-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18292730

RESUMO

A 45-year-old male, who had been indicated by brain magnetic resonance imaging to have cerebral infarctions, was found by echocardiography to have a tumor in the left atrium. He had experienced several of the constitutional disturbances associated with myxoma. At the ages of 19 and 35 he had had two episodes associated with embolisms, and at the later one he was diagnosed as having multiple cerebral aneurysms. He received an urgent operation in which three left atrial tumors and one right atrial tumor were resected. Histologically, the tumors were myxomas, and the left atrial main tumor had glandular structure. In view of his clinical history, this patient seems to have had cardiac myxomas for a long period. The multiple growths that occurred in this case may be a good argument for allowing this condition to last for so long. To our knowledge, the present case was the first report of cardiac myxoma with glandular structure in Japan.


Assuntos
Átrios do Coração , Neoplasias Cardíacas/patologia , Mixoma/patologia , Infarto Cerebral/epidemiologia , Comorbidade , Neoplasias Cardíacas/diagnóstico por imagem , Neoplasias Cardíacas/epidemiologia , Neoplasias Cardíacas/cirurgia , Humanos , Aneurisma Intracraniano/epidemiologia , Embolia Intracraniana/epidemiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mixoma/diagnóstico por imagem , Mixoma/epidemiologia , Mixoma/cirurgia , Doença de Raynaud/epidemiologia , Ultrassonografia
5.
J Thorac Cardiovasc Surg ; 132(6): 1447-54, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17140974

RESUMO

OBJECTIVE: The purpose of this study was to investigate the effects of cardiopulmonary bypass and ultrafiltration on graft function in a canine single-lung transplantation model. METHODS: Fifteen left single-lung transplantations were done in weight-mismatched canine pairs. The animals were divided into 3 groups: group 1, in which transplantation was done without cardiopulmonary bypass; group 2, in which transplantation was done with cardiopulmonary bypass and in which the cardiopulmonary bypass flow was decreased slowly with controlled pulmonary artery pressure; and group 3, in which transplantation was done with cardiopulmonary bypass and ultrafiltration. Hemodynamic parameters and lung function were monitored for 6 hours after reperfusion. The grafts were harvested for histologic studies, myeloperoxidase assay, and real-time quantitative reverse transcription-polymerase chain reaction of mRNA encoding interleukin 6. RESULTS: The hemodynamic parameters were similar among the 3 groups. In group 1 PaO2 and alveolar to arterial gradient for O2 levels were excellent throughout the 6-hour observation period, but in group 2 they progressively deteriorated. However, ultrafiltration significantly (P = .02) improved the PaO2 level in group 3. On histology, interstitial edema and polynuclear cell infiltration were most marked in group 2 and significantly worse than in groups 1 and 3. Myeloperoxidase assay and real-time quantitative reverse transcription-polymerase chain reaction showed increased myeloperoxidase activity and interleukin 6 gene expression in group 2 grafts compared with group 1 grafts. Myeloperoxidase activity and interleukin 6 gene expression were suppressed with ultrafiltration. CONCLUSIONS: Cardiopulmonary bypass had negative effects on the graft, but ultrafiltration attenuated acute lung dysfunction by reducing the inflammatory response.


Assuntos
Ponte Cardiopulmonar/efeitos adversos , Modelos Animais de Doenças , Hemofiltração , Transplante de Pulmão/fisiologia , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/prevenção & controle , Animais , Cães
6.
Chin Med J (Engl) ; 117(7): 1017-22, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15265375

RESUMO

BACKGROUND: The aim of this study was to identify the subnuclear distribution pattern of human orphan nuclear receptor steroidogenic factor 1 (SF-1) in living cells with and without the activation of protein kinase A (PKA) signal pathway, and thus try to explain the unknown mechanism by which PKA potentiates SF-1 transactivation. METHODS: Full-length cDNAs of wild type and a naturally occurring mutant (G35E) human SF-1 were cloned and fused with green fluorescent protein (GFP). Subcellular distribution pattern of human SF-1 in living cells, whose PKA signaling was either activated or not, was studied by laser confocal microscopy after the validity of the gene sequence was confirmed. RESULTS: The transactivation ability of the GFP-SF-1 chimeric protein was highly conserved. Wild type human SF-1 diffused homogeneously within the nuclei of cells when PKA was not active, and converged to clear foci when PKA was activated. Mutant SF-1 diffused within the nuclei even in the presence of PKA activation, surprisingly aggregating as fluorescent dots inside the nucleoli, a phenomenon not altered by PKA. CONCLUSIONS: Activation of PKA causes wild type, but not mutant SF-1 to alter its subnuclear distribution pattern to a transactivationally active form (foci formation). This finding may throw new light on the mechanism by which PKA activates the orphan nuclear receptor.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Proteínas de Ligação a DNA/análise , Fatores de Transcrição/análise , Compartimento Celular , Núcleo Celular/química , Células Cultivadas , Colforsina/farmacologia , Ativação Enzimática , Feminino , Fatores de Transcrição Fushi Tarazu , Proteínas de Homeodomínio , Humanos , Microscopia Confocal , Receptores Citoplasmáticos e Nucleares , Fator Esteroidogênico 1 , Ativação Transcricional
7.
Mol Endocrinol ; 18(1): 127-41, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14555713

RESUMO

The mechanism through which protein kinase A (PKA) potentiates the transactivation ability of adrenal 4 binding protein/steroidogenic factor 1 (Ad4BP/SF-1) is currently unclear. In the present study, we investigated the mechanism by applying laser confocal microscopy and fluorescence recovery after photobleaching technique. In KGN cells, forskolin (a PKA stimulator) could reorganize wild-type Ad4BP/SF-1, but not mutant Ad4BP/SF-1 (G35E), from a diffuse distribution pattern to foci formation in the nucleus. The subcellular distributions of GCN5 (general control nonderepressed) and TRRAP (transformation/transcription domain-associated protein), both of which were recently proved to be working in the same complex as the third class of nuclear receptor coactivators, were unexpectedly diffuse inside and outside the nucleus, respectively, when they were separately transfected. However TRRAP was translocated into the nucleus in the presence of GCN5, and together with GCN5 colocalized with Ad4BP/SF-1 in the same foci when PKA was activated. A luciferase assay also indicated that these two cofactors enhanced Ad4BP/SF-1 transactivation.Dosage-sensitive sex reversal (DAX-1) interacts with and thus inhibits Ad4BP/SF-1 transactivation. The coexistence of the two proteins dramatically altered their respective subnuclear distributions. They colocalized extensively, suggestive of binding, and Ad4BP/SF-1 was sharply immobilized when DAX-1 was coexpressed, whereas PKA could maintain mobility, as evidenced by Fluorescence Recovery After Photobleaching showing that Ad4BP/SF-1 mobility recovered after forskolin treatment.Therefore, the PKA signal pathway may modify the interaction between Ad4BP/SF-1 and its activators and repressor (GCN5 and TRRAP are integrated, whereas DAX-1 is disassociated), and thus stimulate the Ad4BP/SF-1 transactivation.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Ativação Transcricional/genética , Proteínas Adaptadoras de Transdução de Sinal , Substituição de Aminoácidos , Proteínas de Ciclo Celular , Linhagem Celular , Linhagem Celular Tumoral , Clonagem Molecular , Receptor Nuclear Órfão DAX-1 , Feminino , Fatores de Transcrição Fushi Tarazu , Regulação Neoplásica da Expressão Gênica/genética , Biblioteca Gênica , Genes Reporter , Histona Acetiltransferases , Humanos , Luciferases/análise , Luciferases/genética , Mutagênese Sítio-Dirigida , Proteínas Nucleares/genética , Neoplasias Ovarianas , Plasmídeos , Receptores Citoplasmáticos e Nucleares/fisiologia , Receptores do Ácido Retinoico/genética , Proteínas Repressoras/genética , Baço , Transativadores/genética , Transfecção , Fatores de Transcrição de p300-CBP
8.
Eur Heart J ; 24(24): 2180-5, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14659769

RESUMO

AIMS: Oxidative stress is implicated in the progression of heart failure, and matrix metalloproteinase (MMP) activity is increased in patients with congestive heart failure. We examined the role of oxidative stress on MMP activity in humans. METHODS AND RESULTS: We measured the MMP activity and the level of 8-iso-prostagandin F2alpha (8-iso-PGF2alpha), a specific and quantitative maker of oxidant stress, in the pericardial fluid (PF) in 47 consecutive patients with coronary artery disease who underwent coronary artery bypass surgery. Zymography of PF showed bands at 92-85kDa (MMP-9) and 72-65kDa (MMP-2). The MMP activity was expressed as the ratio to MMP-2 standard. MMP-2, MMP-9 and total gelatinolysis activities were positively correlated with left ventricular end-diastolic volume index (LVEDVI), and MMP-2 and total gelatinolysis activities were also positively correlated with LV end-systolic volume index. Moreover, MMP-2, MMP-9 and total gelatinolysis activities were all positively correlated with pericardial level of 8-iso-PGF2alpha. Also, LVDEVI was positively correlated with pericardial level of 8-iso-PGF2alpha. CONCLUSIONS: Oxidative stress may play an important role in the regulation of MMP activity. Augmented MMP activity may be involved in the development of ventricular remodelling in patients with coronary artery disease.


Assuntos
Doença da Artéria Coronariana/etiologia , Metaloproteinases da Matriz/metabolismo , Estresse Oxidativo/fisiologia , Remodelação Ventricular/fisiologia , Idoso , Doença da Artéria Coronariana/enzimologia , Feminino , Humanos , Masculino , Pericárdio/química , Prostaglandinas A/análise
9.
Kidney Int ; 64(6): 2291-7, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14633154

RESUMO

BACKGROUND: Plasma asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), is an independent predictor of overall mortality and cardiovascular outcome in hemodialysis patients. However, not only ADMA but also traditional risk factors account for only part of the high cardiovascular morbidity and mortality in these patients. We investigated cross-sectionally the association between coupling factor 6 (CF6), an endogenous inhibitor of prostacyclin synthesis, and cardiovascular events in 95 hemodialysis patients. METHODS: Plasma CF6 level was measured by radioimmunoassay, whereas plasma ADMA level by high-performance liquid chromatography (HPLC). RESULTS: Plasma levels of CF6 and ADMA were threefold higher in hemodialysis patients than in control individuals, and there was a positive correlation between these two compounds (r=0.25, P < 0.05). Plasma CF6 level was positively correlated with serum creatinine level (r=0.36, P < 0.01) and was reduced after dialysis (P < 0.05). Plasma CF6 and ADMA levels were both higher in hemodialysis patients complicating ischemic heart disease (myocardial infarction and/or angina) than in those free of cardiovascular events. In a multiple regression model, plasma CF6 level (r=0.24, P=0.023) and ADMA level (r=0.26, P=0.023) were independently related to the occurrence of ischemic heart disease in hemodialysis patients. CONCLUSION: CF6 is a novel risk factor for ischemic heart disease in end-stage renal disease (ESRD). Synergism of this peptide and ADMA might contribute to its occurrence presumably by inhibition of prostacyclin and nitric oxide production. A prospective study is needed to evaluate this issue more precisely.


Assuntos
Arginina/análogos & derivados , Doenças Cardiovasculares/etiologia , Falência Renal Crônica/sangue , Falência Renal Crônica/complicações , ATPases Mitocondriais Próton-Translocadoras/sangue , Fatores Acopladores da Fosforilação Oxidativa/sangue , Idoso , Arginina/sangue , Cromatografia Líquida de Alta Pressão , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioimunoensaio , Fatores de Risco
10.
Hypertension ; 42(5): 985-90, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14557285

RESUMO

We demonstrated recently that plasma concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthase, are increased by high salt intake concomitantly with a decrease in plasma levels of NO in human hypertension. We investigated the effect of shear stress on ADMA release in 2 types of cells: transformed human umbilical vein endothelial cells (HUVECs; cell line ECV-304) and HUVECs. Exposure of ECV-304 cells and HUVECs to shear stress with the use of a cone-plate viscometer enhanced gene expression of protein arginine methyltransferase (PRMT-1), ADMA synthase. In HUVECs, the ratio of PRMT-1 to glyceraldehyde 3-phosphate dehydrogenase mRNA was increased by 2-fold by a shear stress of > or =15 dyne/cm2. A dominant-negative mutant of IkappaB kinase alpha and troglitazone at 8 micromol/L, an activator of peroxisome proliferator-activated receptor gamma, abolished the shear stress-induced increase in PRMT-1 gene expression in parallel with the blockade of nuclear factor (NF)-kappaB translocation into the nucleus. The activity of dimethylarginine dimethylaminohydrolase, the degradation enzyme of ADMA, was unchanged after shear stress < or =15 dyne/cm2 and was enhanced by 1.48+/-0.06-fold (P<0.05) by shear stress at 25 dyne/cm2. The release of ADMA was increased by 1.64+/-0.10-fold (P<0.05) by shear stress at 15 dyne/cm2 but was not affected by shear stress at 25 dyne/cm2. These results indicate that shear stress enhances gene expression of PRMT-1 and ADMA release via activation of the NF-kappaB pathway. Shear stress at higher magnitudes facilitates the degradation of ADMA, thus returning ADMA release levels to baseline.


Assuntos
Arginina/análogos & derivados , Arginina/metabolismo , Endotélio Vascular/metabolismo , Amidoidrolases/metabolismo , Linhagem Celular Transformada , Endotélio Vascular/enzimologia , Regulação da Expressão Gênica , Humanos , Microscopia de Fluorescência , NF-kappa B/análise , NF-kappa B/imunologia , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Estresse Mecânico , Fator de Transcrição RelA
11.
Heart Vessels ; 18(4): 177-82, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14520484

RESUMO

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is elevated in congestive heart failure (CHF) concomitantly with the higher levels of nitric oxide (NO) and cytokines. We investigated the association among ADMA, NO, and cytokines in human CHF. Blood was collected from 25 patients with acutely exacerbated chronic CHF (acute CHF, mean age 61 +/- 3 years), 23 patients with chronic compensated CHF (chronic CHF, mean age 62 +/- 2 years), and 26 control subjects (mean age 51 +/- 1 years). ADMA was measured by high-performance liquid chromatography. Tumor necrosis factor-alpha (TNF-alpha) was measured by enzyme-linked immunosorbent assay. Nitrate plus nitrite (NOx) was measured by the Griess method. The plasma levels of ADMA and TNF-Alpha were higher in patients with acute CHF than in those with chronic CHF and control subjects (both P < 0.05). The plasma level of NOx was higher in patients with chronic CHF than in those with acute CHF and control subjects (both P < 0.01). The plasma level of TNF-Alpha was positively correlated with that of ADMA in combination with patients with acute and chronic CHF (r = 0.31, P < 0.01). The plasma level of ADMA was, furthermore, negatively correlated with that of NOx (r = -0.29, P < 0.05). These findings indicate that ADMA is related to exacerbation of chronic CHF by suppression of the compensatory higher level of plasma NO.


Assuntos
Arginina/análogos & derivados , Arginina/sangue , Citocinas/sangue , Insuficiência Cardíaca/sangue , Óxido Nítrico/sangue , Fator de Necrose Tumoral alfa/metabolismo , Doença Aguda , Cromatografia Líquida de Alta Pressão , Doença Crônica , Inibidores Enzimáticos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico Sintase/antagonistas & inibidores
12.
Blood Purif ; 20(5): 466-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12207094

RESUMO

Patients with essential hypertension (n = 24) were administered a low-salt diet (2 g NaCl/day), a high-salt diet (20-23 g) and then a low-salt diet for 7 days, and plasma levels of nitrate and nitrite (NOx) and asymmetric dimethylarginine (ADMA) were examined. There was a negative correlation between the percent changes in mean blood pressure and the plasma NOx concentration after salt loading and restriction. The percent change in plasma ADMA concentration was negatively correlated with that in the plasma NOx concentration after salt loading and restriction. In patients with end-stage renal disease (n = 51), the plasma ADMA concentration was positively correlated with the duration of dialysis treatment. The frequency of cardiovascular events was greater in patients with a plasma ADMA level of >/=3 microM than in those with a plasma AMDA level of <3 microM. The results indicate that ADMA is not only a modulator of salt sensitivity in hypertension but also a cardiovascular risk factor in end-stage renal disease.


Assuntos
Arginina/análogos & derivados , Arginina/sangue , Falência Renal Crônica/dietoterapia , Óxido Nítrico/sangue , Cloreto de Sódio/farmacologia , Arginina/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Doenças Cardiovasculares/etiologia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/dietoterapia , Hipertensão/metabolismo , Falência Renal Crônica/sangue , Falência Renal Crônica/metabolismo , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Nitritos/sangue , Diálise Renal , Fatores de Risco , Cloreto de Sódio/administração & dosagem
13.
J Biol Chem ; 277(33): 30031-9, 2002 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-12039962

RESUMO

In the androgen receptor (AR), most of its transactivation activity is mediated via the activation function-1 (AF-1). By employing yeast two-hybrid assay, we isolated a cDNA sequence encoding a protein binding to AR-AF-1. This protein, named ANT-1 (AR N-terminal domain transactivating protein-1), enhanced the ligand-independent autonomous AF-1 transactivation function of AR or glucocorticoid receptor but did not enhance that of estrogen receptor alpha. In contrast, the ANT-1 did not enhance any ligand-dependent AF-2 activities. Furthermore, the ligand-independent interaction between AR-AF-1 and ANT-1 was confirmed in vivo and in vitro. The ANT-1 sequence was identical to that of a protein that binds to U5 small nuclear ribonucleoprotein particle, a human homologue of yeast splicing factor Prp6p, involved in spliceosome. ANT-1 was compartmentalized into 20-40 coarse splicing factor compartment speckles against the background of the diffuse reticular distribution. AR colocalized with ANT-1 only in the diffusely distributed area, whereas the ANT-1 speckles were spatially distinct from but surrounded by the AR compartments. The active gene transcription has been shown to couple simultaneously with pre-mRNA processing at the periphery of the splicing factor compartment. The molecular interaction between two spatially distinct subnuclear compartments mediated by ANT-1 may therefore recruit AR into the transcription-splicing-coupling machinery.


Assuntos
Splicing de RNA , Receptores Androgênicos/metabolismo , Ribonucleoproteína Nuclear Pequena U5/metabolismo , Animais , Compartimento Celular , Linhagem Celular , Clonagem Molecular , DNA Complementar , Humanos , Testes de Precipitina , Receptores Androgênicos/química , Ribonucleoproteína Nuclear Pequena U5/genética , Técnicas do Sistema de Duplo-Híbrido
14.
Mol Endocrinol ; 16(4): 694-706, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11923466

RESUMO

To clarify the physiological significance of the intranuclear speckled distribution, or foci formation, of liganded steroid receptors, the subnuclear distribution of green (GFP), yellow (YFP), and cyan (CFP) fluorescent protein-tagged receptors and coactivators was investigated. The foci formation of 5 alpha-dihydrotestosterone (DHT)-bound AR-GFP in COS7 cells was abolished by the cotransfection of a CBP Delta (118-2393) fragment eliciting a dominant negative effect on the transactivation capacity of the AR. The N-terminal AR fragment (AR-AF-1-YFP), which has a strong constitutive transactivation function, formed foci without DHT, whereas the C-terminal AR fragment (AR-AF-2-CFP), which has a quite low transactivation function, was distributed homogeneously even in the presence of DHT. The reporter gene assay showed a synergism between the transactivation functions of AR-AF-1 and AR-AF-2. This synergism was not reflected by the above two-dimensional imaging. In contrast, a three-dimensional imaging method clearly showed a difference in the intranuclear spatial distribution. The DHT-bound wild-type AR-GFP alone or AR-AF-1-YFP plus DHT-bound AR-AF-2-CFP was distributed as approximately 300 discrete spots in one nucleus, whereas AR-AF-1-YFP alone was distributed as one volume in a reticular pattern. Furthermore, not only AR but also the glucocorticoid receptor-YFP, ER alpha -GFP, and YFP-tagged SRC-1, TIF2, and CBP were found to be accumulated in identical spots in the presence of ligand. All of the above results indicate that CBP is one of the factors essential for foci formation of the AR, and may propose the hypothesis that transcriptionally activated steroid receptors, regardless of the type of receptor, are transferred to common compartments (foci) and form a complex with coactivators, and this process is essential to full transactivation.


Assuntos
Receptores Androgênicos/fisiologia , Ativação Transcricional , Animais , Células COS , Compartimento Celular , Di-Hidrotestosterona/metabolismo , Corantes Fluorescentes/metabolismo , Genes Reporter , Proteínas de Fluorescência Verde , Histona Acetiltransferases , Humanos , Imageamento Tridimensional , Luciferases/genética , Proteínas Luminescentes/metabolismo , Masculino , Microscopia de Fluorescência , Coativador 1 de Receptor Nuclear , Coativador 2 de Receptor Nuclear , Receptores Androgênicos/química , Receptores Androgênicos/genética , Relação Estrutura-Atividade , Fatores de Transcrição/metabolismo , Transfecção , Células Tumorais Cultivadas
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