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1.
J Exp Med ; 194(7): 893-902, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11581312

RESUMO

Cytotoxic T lymphocyte antigen (CTLA)-4 plays an essential role in immunologic homeostasis. How this negative regulator of T cell activation executes its functions has remained controversial. We now provide evidence that CTLA-4 mediates a cell-intrinsic counterbalance to restrict the clonal expansion of proliferating CD4(+) T cells. The regulation of CTLA-4 expression and function ensures that, after approximately 3 cell divisions of expansion, most progeny will succumb to either proliferative arrest or death over the ensuing three cell divisions. The quantitative precision of the counterbalance hinges on the graded, time-independent induction of CTLA-4 expression during the first three cell divisions. In contrast to the limits imposed on unpolarized cells, T helper type 1 (Th1) and Th2 effector progeny may be rescued from proliferative arrest by interleukin (IL)-12 and IL-4 signaling, respectively, allowing appropriately stimulated progeny to proceed to the stage of tissue homing. These results suggest that the cell-autonomous regulation of CTLA-4 induction may be a central checkpoint of clonal expansion of CD4(+) T cells, allowing temporally and spatially restricted growth of progeny to be dictated by the nature of the threat posed to the host.


Assuntos
Antígenos de Diferenciação/metabolismo , Imunoconjugados , Imunossupressores/metabolismo , Ativação Linfocitária , Linfócitos T Auxiliares-Indutores/imunologia , Abatacepte , Animais , Antígenos CD , Antígeno CTLA-4 , Morte Celular , Divisão Celular , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
2.
Science ; 292(5523): 1907-10, 2001 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-11397944

RESUMO

How cytokines control differentiation of helper T (TH) cells is controversial. We show that T-bet, without apparent assistance from interleukin 12 (IL-12)/STAT4, specifies TH1 effector fate by targeting chromatin remodeling to individual interferon-gamma (IFN-gamma) alleles and by inducing IL-12 receptor beta2 expression. Subsequently, it appears that IL-12/STAT4 serves two essential functions in the development of TH1 cells: as growth signal, inducing survival and cell division; and as trans-activator, prolonging IFN-gamma synthesis through a genetic interaction with the coactivator, CREB-binding protein. These results suggest that a cytokine does not simply induce TH fate choice but instead may act as an essential secondary stimulus that mediates selective survival of a lineage.


Assuntos
Interferon gama/biossíntese , Interleucina-12/metabolismo , Células Th1/imunologia , Fatores de Transcrição/metabolismo , Alelos , Animais , Proteína de Ligação a CREB , Diferenciação Celular , Divisão Celular , Linhagem da Célula , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Histonas/metabolismo , Interferon gama/genética , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Nucleares/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Interleucina/metabolismo , Receptores de Interleucina-12 , Fator de Transcrição STAT4 , Transdução de Sinais , Proteínas com Domínio T , Células Th1/citologia , Células Th1/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/genética
3.
Curr Biol ; 11(21): 1695-9, 2001 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-11696328

RESUMO

Naïve CD4(+) helper T (T(H)) cells respond to stimulation by terminally differentiating into two mature classes, T(H)1 cells, which express interferon gamma (IFN-gamma), and T(H)2 cells, which express interleukin 4 (IL-4). The transcriptional activators T-bet and Gata-3 mediate commitment to the T(H)1 and T(H)2 fates, respectively, including chromatin remodeling of signature genes. The cytokine IL-12 fosters growth of committed T(H)1 cells, while IL-4 fosters growth of committed T(H)2 cells. IL-12 and IL-4 also play critical roles in commitment by promoting transcriptional silencing of Gata-3 and T-bet, respectively. We now show that both T-bet and Gata-3 are induced in a cell cycle-independent manner in bipotent progenitor cells. In contrast, both lineage-restricted gene induction by the activator proteins and heritable silencing of the transcription of each activator, the hallmarks of terminal differentiation, are cell cycle dependent. We found that cells that cannot cycle remain uncommitted and bipotent in response to the most polarizing signals for maturation. These results provide mechanistic insight into a mammalian model of terminal differentiation by illustrating that cell cycle-coupled epigenetic effects, as originally described in yeast, may represent an evolutionarily conserved strategy for organizing signaling and cell fate.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Linfócitos T Auxiliares-Indutores/citologia , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Ciclo Celular , Diferenciação Celular , Linhagem da Célula , Fator de Transcrição GATA3 , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/imunologia , Interferon gama/metabolismo , Interleucina-12/metabolismo , Interleucina-4/metabolismo , Modelos Imunológicos , Proteínas com Domínio T , Linfócitos T Auxiliares-Indutores/imunologia , Células Th1/citologia , Células Th1/imunologia , Células Th2/citologia , Células Th2/imunologia , Fator de Crescimento Transformador beta/metabolismo
4.
Cancer Res ; 59(8): 2011-7, 1999 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10213514

RESUMO

Breast cancers arising in women with and without a germline mutation in the BRCA1 or BRCA2 gene display different histological features, which suggests unique mechanisms of molecular pathogenesis: We used a molecular pathological analysis to define the genetic abnormalities relevant to these specific pathogeneses. Tumor material was studied from 40 women with breast cancer diagnosed before 40 years of age, sampled from a population-based study and stratified by BRCA1 and BRCA2 germline mutation status. Cases were not selected for family history or ethnic origin, and none were known to be genetically related. Thus, germline mutation itself is likely to impact on the molecular pathogenesis of these tumors, with no substantial influence due to modifying genetic or environmental factors. Breast cancers occurring in BRCA1 mutation carriers had significantly higher levels of p53 expression, including the preinvasive (carcinoma in situ) stage of disease, compared with cancers occurring in BRCA2 mutation carriers or women with no detectable germline mutation. These cancers also had a higher proliferation rate as measured by Ki-67 antibody. Expression of the prognostic factors c-erbB-2, cyclin D1, and estrogen receptor was significantly less common in BRCA1 mutation carriers. Lower levels of cyclin D1 were also found in cancers from BRCA2 mutation carriers compared with non-mutation carriers. Direct p53 mutation analysis revealed mutations in 18% of all of the early-onset breast cancers within the study and included rare insertion and deletional mutations in cancers from BRCA1 mutation carriers. Our data indicate that a BRCA1 breast cancer phenotype may be recognized by an exceptionally high proliferation rate and early and frequent p53 overexpression but infrequent selection for overexpression of several other prognostic factor proteins known to be involved in breast oncogenesis. In contrast, breast cancers arising in BRCA2 mutation carriers have a more heterogeneous phenotypic profile.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Proteínas de Neoplasias/genética , Fatores de Transcrição/genética , Idade de Início , Proteína BRCA2 , Neoplasias da Mama/patologia , Neoplasias da Mama/fisiopatologia , Feminino , Genética Populacional , Humanos , Imuno-Histoquímica , Perda de Heterozigosidade , Mutação , Invasividade Neoplásica/genética , Proteína Supressora de Tumor p53/genética
5.
Biochim Biophys Acta ; 1263(3): 266-70, 1995 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-7548217

RESUMO

The gene for the sheep arginine vasopressin type 1a (V1a) receptor subtype was cloned from a genomic library. The deduced amino acid sequence shows characteristics of a G-protein coupled receptor and high sequence identity to human and rat V1a receptor sequences (81% and 73%, respectively). Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed a tissue distribution consistent with a type V1a receptor. The genomic DNA (7.1 kb) contains a 1586 bp intron between the putative 6th and 7th transmembrane domains.


Assuntos
Receptores de Vasopressinas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA/química , Biblioteca Genômica , Dados de Sequência Molecular , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Ovinos
6.
Biochim Biophys Acta ; 951(1): 85-97, 1988 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-2847799

RESUMO

The cold-sensitive (proliferating at 39.5 degrees C, reversibly arrested in GI-phase at 33 degrees C) cell-cycle mutant 21-Fb of the murine mastocytoma cell line P815 was used to study the effect of amsacrine on non-cycling cells. The sensitivity of arrested 21-Fb cells decreased less than 2-fold in cell survival experiments when compared to proliferating cells. In contrast, DNA breakage and stimulation of protein-DNA complex formation in intact or lysed cells was reduced approx. 10-fold in arrested cells and DNA topoisomerase II activity in arrested cells was only 5% of the activity in proliferating cells. Thus, there was no correlation between cell survival and DNA damage or DNA topoisomerase II activity in drug-treated cells.


Assuntos
Amsacrina/farmacologia , Ciclo Celular , Dano ao DNA , DNA Topoisomerases Tipo II/metabolismo , Animais , Divisão Celular , Sobrevivência Celular/efeitos dos fármacos , Temperatura Baixa , DNA/efeitos dos fármacos , DNA/metabolismo , Sarcoma de Mastócitos , Camundongos , Mutação , Proteínas/metabolismo , Células Tumorais Cultivadas
7.
Biochim Biophys Acta ; 1309(1-2): 77-80, 1996 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-8950181

RESUMO

A novel human P2 nucleotide receptor has been cloned from a T-cell cDNA library. The predicted amino acid sequence shows characteristics of a G-protein-coupled receptor, and shares 88% homology with a recently characterised rat P2 nucleotide receptor sequence. Distinctive features include an extremely short cytoplasmic tail with only one putative protein kinase C phosphorylation site. Northern blot analysis revealed a 1.9 kb transcript expressed in the placenta.


Assuntos
DNA Complementar/genética , Receptores Purinérgicos P2/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Proteínas de Ligação ao GTP , Humanos , Dados de Sequência Molecular , Especificidade de Órgãos , RNA Mensageiro/análise , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Linfócitos T
8.
Hypertension ; 26(5): 828-34, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7591025

RESUMO

Abnormalities of the vasopressin system are found in genetic hypertension. This study compares the delayed effects of a brief period of vasopressin V1A receptor blockade and angiotensin-converting enzyme inhibition in young female and male spontaneously hypertensive rats (SHR) on the development of hypertension in adult life. In a separate study, the role of vasopressin in the maintenance of blood pressure in adult SHR was assessed. Young SHR received either the nonpeptide vasopressin V1A receptor antagonist OPC-21268, the angiotensin-converting enzyme inhibitor ramipril, or vehicle from 6 to 10 weeks of age. During the treatment period, OPC-21268 and ramipril reduced systolic blood pressure compared with control SHR (P < .001). Blood pressure in male SHR 7 weeks after treatment withdrawal was 178 +/- 1 mm Hg in ramipril-treated, 184 +/- 1 mm Hg in OPC-21268-treated, and 200 +/- 2 mm Hg in control SHR (P < .001). Similar results were seen in female SHR, although both OPC-21268 and ramipril were less effective antihypertensive agents in female compared with male SHR. The sustained attenuation in blood pressure was not associated with significant cardiovascular structural changes (left ventricular-to-body weight ratio, renal weight-to-body weight ratio, mesenteric resistance artery media-to-lumen ratio). Results of vasopressin V1A receptor binding kinetics and plasma renin or aldosterone concentrations did not suggest a lasting effect of OPC-21268 on the vasopressin system or of ramipril on the renin-angiotensin system following treatment withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Antagonistas dos Receptores de Hormônios Antidiuréticos , Hipertensão/prevenção & controle , Piperidinas/uso terapêutico , Quinolonas/uso terapêutico , Ramipril/uso terapêutico , Envelhecimento , Animais , Pressão Sanguínea , Peso Corporal , Feminino , Hipertensão/genética , Hipertensão/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos SHR
9.
Am J Clin Nutr ; 66(1): 46-51, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9209168

RESUMO

Soybeans contain isoflavones, which have been associated with many health benefits, including decreased cancer risk. The purpose of our study was to measure urinary isoflavonoid excretion in response to daily consumption of soy that contained 0-36 mg isoflavones--a lower range than used in previous studies--and to compare urinary isoflavonoid excretion between equol excreters and nonexcreters. Fourteen men and women aged 20-40 y participated in the study. Half of the subjects were identified previously as equol excreters and the other half as equol nonexcreters. This randomized, double-blind, crossover study consisted of four 9-d diet treatment periods. During each treatment period participants consumed a low-photoestrogen controlled diet and a beverage containing 0, 5, 10, or 20 g soy protein. Urine collected on the last 3 d of each treatment period was analyzed for isoflavonoid (equol, O-desmethylangolensin, genistein, and daidzein) and lignan (enterodiol and enterolactone) contents by using isotope-dilution gas chromatography-mass spectrometry. There was a highly linear dose response of urinary isoflavonoid excretion to soy consumption, which did not differ significantly between equol excreters and nonexcreters. There were no significant differences in lignan excretion between the two diet treatments. Our results indicate that urinary isoflavonoid excretion is dose dependent in humans at low to moderate levels of soy consumption.


Assuntos
Isoflavonas/urina , Proteínas de Soja/metabolismo , Adulto , Estudos Cross-Over , Método Duplo-Cego , Estrogênios não Esteroides/urina , Feminino , Humanos , Masculino , Fitoestrógenos , Preparações de Plantas , Proteínas de Soja/administração & dosagem
10.
Am J Clin Nutr ; 68(6 Suppl): 1492S-1495S, 1998 12.
Artigo em Inglês | MEDLINE | ID: mdl-9848522

RESUMO

In an attempt to explain the wide individual variation seen in urinary isoflavonoid phytoestrogen excretion, we conducted a series of 3 human feeding studies: a large cross-sectional study of equol production in humans with a soy challenge, a comparison of phytoestrogen metabolism when subjects consumed fermented and unfermented soy products, and a dose-response study of urinary isoflavonoid excretion at the low end of soy consumption. All studies were conducted in young, healthy humans. Urinary isoflavonoids were measured by isotope-dilution gas chromatography-mass spectrometry. Similar to results from other studies, 35% of screened subjects (30 men and 30 women) excreted equol (>2000 nmol/d). In women, equol excretion was associated with higher intake of dietary fiber and carbohydrate. Fermentation of soy decreased the isoflavone content of the product fed but increased the urinary isoflavonoid recovery, suggesting that fermentation increases availability of isoflavones in soy. When soy-protein powder was fed at 0, 5, 10, and 20 g/d (0-36 mg isoflavones), there was a linear dose response of urinary isoflavonoid excretion to soy consumption that did not differ between subjects with high and low equol excretion. These results suggest that equol excretion may be related to the fermentable carbohydrate content of the diet; additional study is needed. Processing of soy affects isoflavone metabolism and must be considered in recommending exposure to isoflavones from soyfoods. Although optimal isoflavone exposure for disease protection has not been determined, urinary isoflavonoid excretion appears linear at low-to-moderate soy consumption.


Assuntos
Dieta , Manipulação de Alimentos , Isoflavonas/urina , Proteínas de Soja/administração & dosagem , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Isoflavonas/administração & dosagem , Isoflavonas/metabolismo , Isoflavonas/farmacocinética , Masculino
11.
Cancer Epidemiol Biomarkers Prev ; 9(10): 1113-8, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11045796

RESUMO

Dietary estrogens, such as lignans, are similar in structure to endogenous sex steroid hormones and may act in vivo to alter hormone metabolism and subsequent cancer risk. The objective of this study was to examine the effect of dietary intake of a lignan-rich plant food (flaxseed) on urinary lignan excretion in postmenopausal women. This randomized, cross-over trial consisted of three 7-week feeding periods during which 31 healthy postmenopausal women, ages 52-82 years, consumed their habitual diets plus 0, 5, or 10 grams of ground flaxseed per day. Urine samples collected for 2 consecutive days during the last week of each feeding period were analyzed for lignan content (enterodiol, enterolactone, and matairesinol) by isotope dilution gas chromatography/mass spectrometry. Compared with the 0-gram flaxseed diet, consumption of 5 or 10 grams of flaxseed significantly increased excretion of enterodiol by 1,009 and 2,867 nmol/day, respectively; significantly increased excretion of enterolactone by 21,242 and 52,826 nmol/day, respectively; and significantly increased excretion of total lignans (enterodiol + enterolactone + matairesinol) by 24,333 and 60,640 nmol/day, respectively. Excretion of matairesinol was not significantly altered by flaxseed consumption. Consumption of flax, a significant source of dietary estrogens, in addition to their habitual diets increased excretion of enterodiol and enterolactone, but not matairesinol, in a dose-dependent manner in this group of postmenopausal women. Urinary excretion of lignan metabolites is a dose-dependent biomarker of flaxseed intake within the context of a habitual diet.


Assuntos
Linho , Lignanas/urina , Pós-Menopausa , Idoso , Biomarcadores/análise , Estudos Cross-Over , Dieta , Relação Dose-Resposta a Droga , Feminino , Humanos , Pessoa de Meia-Idade
12.
Cancer Epidemiol Biomarkers Prev ; 8(8): 699-707, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10744130

RESUMO

Dietary isoflavone and lignan phytoestrogens are potential chemopreventive agents. This has led to a need to monitor exposure to these compounds in human populations and to determine which components of a mixed diet contribute to the exposure. Typically, urinary isoflavonoid excretion is associated with soy consumption and that of lignans is associated with whole grains. However, other plant foods are known to contain phytoestrogen precursors. The purpose of this study was to examine the association between urinary isoflavonoid and lignan excretion and intakes of vegetables and fruits (V&F). Isoflavonoids (genistein, daidzein, O-desmethylangolensin, and equol) and lignans (enterolactone, enterodiol, and matairesinol) were measured in urine collected for 3 days from 49 male and 49 female volunteers (age, 18-37 years) reporting a wide range of habitual V&F intakes. Dietary intakes were assessed using 5-day diet records and a food frequency questionnaire. V&F groupings (total V&F, total V, total F, soyfoods, and V&F grouped by botanical families) were used to assess the relationship between V&F intake and urinary isoflavonoid and lignan excretion. Pearson correlations were performed. Intake of soyfoods was correlated significantly with urinary genistein (r = 0.40; P = 0.0001), O-desmethylangolensin (r = 0.37; P = 0.0002), daidzein (r = 034; P = 0.0007), and the sum of isoflavonoids (r = 0.39; P = 0.0001). There was no association between equol excretion and soy intake or between the isoflavonoids and any other V&F groupings. In addition, isoflavonoid excretion was correlated positively with intake of high-fat and processed meats, particularly among men who did not consume soy. This suggests that, even in the United States, on a Western diet, soyfoods are the primary contributors to isoflavone intake; however, additional "hidden sources" of soy may also contribute to exposure. In contrast, a variety of fiber-containing foods contributed to lignan excretion; the sum of the urinary lignans, enterodiol, enterolactone, and matairesinol, was associated with intake of total F (r = 0.27; P = 0.008), total V&F (r = 0.25; P = 0.01), soyfoods (r = 0.28; P = 0.006), and dietary fiber (r = 0.36; P = 0.0003). Overall, urinary phytoestrogens (isoflavonoids + lignans) were significantly higher in "high" compared with "low" V&F consumers. Compared with the "low" V&F group, the "high" group consumed diets that were, on average, higher in fiber and carbohydrate and soyfoods and lower in fat; thus, the urinary phytoestrogens may also be a useful marker of healthier dietary patterns.


Assuntos
Frutas , Isoflavonas/urina , Lignanas/urina , Proteínas de Soja , Verduras , Adolescente , Adulto , Estudos Transversais , Fibras na Dieta , Feminino , Humanos , Masculino
13.
J Mol Endocrinol ; 15(2): 105-15, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8800636

RESUMO

The insulin-like growth factors (IGF-I and IGF-II), their receptors and binding proteins (IGFBPs) are endogenously expressed in a number of tissues including the lung during fetal and neonatal development. This endogenous autocrine/paracrine IGF 'system', together with endocrine sources, contributes to the regulation of lung cell proliferation. We investigated the expression of the mRNAs encoding IGF-I, IGF-II, the type 1 IGF receptor (IGF-T1R) and two IGF-binding proteins (IGFBP-2 and IGFBP-4) in rat lung during the perinatum. These were compared in lung with surfactant apoprotein A (Sp-A) mRNA levels. mRNA in extracts of fetal tissues collected between day 17 of gestation (17f) and day 9 after birth (9d) was estimated by Northern blot or RNase protection analysis. At day 20 of gestation IGF-I, IGF-T1R and IGFBP-4 mRNA levels were higher in lung than liver (all P < 0.01), whereas IGF-II and IGFBP-2 mRNA levels were higher in liver than lung (each P < 0.02). The expression of IGF-1, IGFBP-2 and IGFBP-4 in lung was high before birth (days 17-20f) but decreased to low levels at days 21f, 22f or at birth (1d) but increased in the neonatal lung. IGF-II expression in lung was high at 17f but decreased before birth and remained low after birth. The IGF-T1R was expressed at moderate levels before birth, decrease before birth but peaked at days 2-5 after birth. The decrease in expression of these growth regulators before birth expression of these growth regulators before birth was matched by an increased in Sp-A expression which was clearly seen at day 20f, peaked at 1d and then was clearly seen at day 20f, peaked at 1d and then was maintained at high levels after birth. Primary cell cultures of 18f lung epithelia express IGFBP-2 while fibroblasts from the same animals express only IGFBP-4. Cells grown from 22f lung tissue express IGFBP-2 and IGFBP-4 at lower levels, behaving in vitro as they do in vivo. The contrasting levels of expression of different components of the IGF system in the fetal lung and liver indicate organ-specific regulation. IGFBP-2 and IGFBP-4 expression in different cell types within lung but with similar temporal changes suggests cell-specific regulation, perhaps by a common agent. The patterns by a common agent. The patterns of expression of IGF-I, IGF-T1R, IGFBP-2 and IGFBP-4, but not IGF-II, in developing lung correspond to previously described phasic changes in lung cell proliferation rates. The nadir in expression of these four major components of the lung IGF system occurs in the saccular phase when the lung begins to differentiate, probably under the influence of certain endocrine agents.


Assuntos
Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/biossíntese , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/biossíntese , Fator de Crescimento Insulin-Like II/biossíntese , Fator de Crescimento Insulin-Like I/biossíntese , Pulmão/metabolismo , Receptor IGF Tipo 1/biossíntese , Envelhecimento , Animais , Animais Recém-Nascidos , DNA Complementar , Desenvolvimento Embrionário e Fetal , Feminino , Feto , Expressão Gênica , Idade Gestacional , Fígado/embriologia , Fígado/metabolismo , Pulmão/embriologia , Pulmão/crescimento & desenvolvimento , Sondas de Oligonucleotídeos , Gravidez , Proteolipídeos/biossíntese , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares , Surfactantes Pulmonares/biossíntese , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Ratos
14.
J Endocrinol ; 138(2): 259-66, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8228734

RESUMO

A non-peptide, orally effective, vasopressin (AVP) V1 receptor antagonist 1-(1-[4-(3-acetylaminopropoxy) benzoyl]-4-piperidyl)-3,4-dihydro-2(1H)-quinolinone (OPC-21268) has recently been described. This paper reports the in-vitro and in-vivo characterization of OPC-21268 binding to vasopressin receptors in rat liver and kidney. OPC-21268 caused a concentration-dependent displacement of the selective V1 receptor antagonist radioligand, 125I-labelled [d(CH2)5,sarcosine7]AVP to V1 receptors in both rat liver and kidney medulla membranes. The concentration of OPC-21268 that displaced 50% of specific AVP binding (IC50) was 40 +/- 3 nmol/l for liver V1 and 15 +/- 2 nmol/l for kidney V1 receptors (mean +/- S.E.M.; n = 3). OPC-21268 had little effect on the selective V2 antagonist radioligand [3H]desGly-NH2(9)]d(CH2)5,D-Ile2,Ile4] AVP binding to V2 receptors in renal medulla membranes (IC50 > 0.1 mmol/l). After oral administration to rats, OPC-21268 was an effective V1 antagonist in a time- and dose-dependent manner. Binding kinetic studies showed that OPC-21268 acted as a competitive antagonist at the liver V1 receptor in vitro and in vivo, in addition to its in-vitro competitive effects at the renal V1 receptor. OPC-21268 shows promise as an orally active V1 antagonist.


Assuntos
Antagonistas dos Receptores de Hormônios Antidiuréticos , Piperidinas/farmacologia , Quinolonas/farmacologia , Animais , Arginina Vasopressina/metabolismo , Relação Dose-Resposta a Droga , Feminino , Técnicas In Vitro , Medula Renal/metabolismo , Fígado/metabolismo , Ligação Proteica , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
15.
J Steroid Biochem Mol Biol ; 75(1): 33-42, 2000 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11179906

RESUMO

We have characterized a series of nonsteroidal progesterone receptor ligands, the tetrahydropyridazines. Compounds in this series, exemplified by RWJ 26819, demonstrate high affinity and unprecedented specificity for the progesterone receptor relative to other steroid hormone receptors. Like steroidal progestins, RWJ 26819 induces binding of the receptor to a progesterone response element in vitro, and stimulates gene expression in and proliferation of T47D human breast cancer cells. When administered to rabbits orally or subcutaneously, the compound induces histological changes in the uterine lining comparable to those induced by levonorgestrel. It also inhibits ovulation in monkeys. Though less potent in cells and in animal models than would be predicted from binding affinity alone, their enhanced selectivity suggests that they could be effectively used in a clinical setting. Most of the tetrahydropyridazines synthesized are progestin agonists or mixed agonists and antagonists in vitro; however, one compound with antagonist activity in the rabbit uterine transformation assay has been identified.


Assuntos
Mifepristona , Piperazinas/metabolismo , Piperidinas/metabolismo , Receptores de Progesterona/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/metabolismo , Divisão Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Endométrio/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Levanogestrel/metabolismo , Macaca fascicularis , Mifepristona/metabolismo , Ovulação/efeitos dos fármacos , Piperazinas/química , Piperazinas/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Progesterona/metabolismo , Ligação Proteica/efeitos dos fármacos , Piridazinas/química , Piridazinas/metabolismo , Piridazinas/farmacologia , Coelhos , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Glucocorticoides/metabolismo , Especificidade por Substrato , Células Tumorais Cultivadas
16.
Eur J Pharmacol ; 259(3): 325-9, 1994 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-7982462

RESUMO

Arginine vasopressin binding site characterisation was performed on purified nuclei and plasma membranes from livers of Sprague-Dawley rats. [125I][d(CH2)5,Sarc7,Arg8]vasopressin, a selective V1 vasopressin receptor antagonist radioligand, bound to the nuclei in a protein concentration and time dependent manner. Scatchard analysis of nuclear binding sites revealed a single binding site with maximal binding site density (Bmax) of 115 +/- 13 fmol/mg protein and affinity (KD) of 5.2 +/- 0.7 nM. Plasma membrane binding demonstrated a Bmax of 529 +/- 25 fmol/mg protein and KD of 1.9 +/- 0.1 nM. The displacement profile for nuclear binding sites using vasopressin analogues was similar to that for plasma membrane binding sites and was typical of a V1 vasopressin receptor type. There was no evidence of V2-like vasopressin receptor binding using [3H]des-Gly-NH9(2)[d(CH2)5,D-Ile2,Ile4,Arg8]vasopressi n, a selective V2 vasopressin receptor radioligand, in the nuclear or membrane fractions. These results suggest the existence of nuclear V1-like vasopressin binding sites.


Assuntos
Núcleo Celular/metabolismo , Fígado/metabolismo , Receptores de Vasopressinas/metabolismo , Animais , Arginina Vasopressina/análogos & derivados , Arginina Vasopressina/farmacocinética , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Núcleo Celular/efeitos dos fármacos , DNA/biossíntese , Feminino , Técnicas In Vitro , Ligantes , Fígado/efeitos dos fármacos , Biossíntese de Proteínas , Ratos , Ratos Sprague-Dawley , Receptores de Vasopressinas/efeitos dos fármacos , Vasopressinas/farmacocinética
17.
Melanoma Res ; 10(3): 259-64, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10890380

RESUMO

MAGE proteins have been identified as potential specific targets for cancer vaccination. Although MAGE-6 and MAGE-12 were originally identified in malignant melanoma there are no studies reporting the frequency of expression of these antigens in this malignancy. These are of relevance particularly for MAGE-6 as recent studies have identified CTL activity against several epitopes. We have studied MAGE-1, -2, -3, -4, -6 and -12 gene expression using reverse transcription-polymerase chain reaction in 47 melanoma samples and 11 melanoma cell lines established from these tumours. The tumour samples expressed MAGE-12 (74%) and MAGE-6 (64%) mRNA at much higher frequencies than the other MAGE genes. MAGE-12 and MAGE-6 were expressed at the highest frequencies, relative to the other MAGE antigens, in early stage lesions. The frequency of expression of all the MAGE genes was found to be higher in samples from metastatic deposits compared to those from locoregional disease. The cell lines all expressed the same or more MAGE antigens than the tumours from which they were derived. In only one cell line was expression of a MAGE antigen lost. Certain recurring patterns of MAGE expression were observed in the tumour samples. MAGE-6 and/or -12 expression were detected in all of those 26 tumour samples that were positive for one or more of MAGE-1, -2, -3 and -4. Twenty of these 26 samples expressed both antigens. These findings suggest that protocols targeting MAGE-12 and -6 would permit many more patients to be included into clinical cancer vaccination trials.


Assuntos
Antígenos de Neoplasias/genética , Melanoma/metabolismo , Proteínas de Neoplasias/genética , RNA Mensageiro/biossíntese , Neoplasias Cutâneas/metabolismo , Adulto , Idoso , Antígenos de Neoplasias/biossíntese , Primers do DNA/química , Expressão Gênica , Humanos , Melanoma/genética , Melanoma/patologia , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Células Tumorais Cultivadas
18.
Steroids ; 66(9): 663-71, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11546554

RESUMO

Estrogens have multiple effects on the growth and development of cells in their target tissues, including the uterus, ovary, breast, bone marrow and brain. The hormone regulates the transcription of diverse genes in these tissues via the estrogen receptor, a nuclear transcription factor. Naturally occurring estrogens and estrogen analogs including selective estrogen receptor modulators (SERMs), constitute important therapies for breast cancer and osteoporosis, and are major components of oral contraceptives. The in vitro biologic activities of pharmaceutical estrogen agonists and antagonists have frequently been monitored by cotransfection assay, where exogenous estrogen receptor and reporter genes are transiently inserted into a heterologous, non receptor-containing cell line, such as those derived from kidney cells. Here we describe an alternative to this method, where induction of an endogenous estrogen-responsive gene, the progesterone receptor gene, is monitored by branched DNA signal amplification. Assays are performed with cultured cells derived from estrogen-responsive tissues; namely, breast, uterine endothelium and bone. Hormonal induction occurs via the endogenous estrogen receptor of these cells. Our data show that SERMs, which are estrogen agonists on bone in vivo, antagonize estrogen-dependent target gene induction in conditionally immortalized osteoblast-like cells.


Assuntos
Ensaio de Amplificação de Sinal de DNA Ramificado , Estrogênios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Receptores de Progesterona/genética , Fosfatase Alcalina/genética , Sequência de Bases , Osso e Ossos/citologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Mama/efeitos dos fármacos , Mama/metabolismo , Linhagem Celular , Endotélio/efeitos dos fármacos , Endotélio/metabolismo , Receptor alfa de Estrogênio , Estrogênios/metabolismo , Feminino , Glicoproteínas/genética , Humanos , Concentração Inibidora 50 , Oligodesoxirribonucleotídeos/genética , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoprotegerina , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cloridrato de Raloxifeno/farmacologia , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Estrogênio/metabolismo , Receptores do Fator de Necrose Tumoral , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Ativação Transcricional , Útero/efeitos dos fármacos , Útero/metabolismo
19.
J Am Diet Assoc ; 95(5): 545-51, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7722188

RESUMO

OBJECTIVE: To compare the effects of consumption of fermented and unfermented soy products on excretion of urinary isoflavonoid phytoestrogens and lignans in healthy men. DESIGN: A randomized, crossover trial consisting of two 9-day feeding periods following 5 days of baseline data collection. SUBJECTS: Healthy men, aged 20 to 40 years, were recruited from the University of Minnesota Twin Cities community. Of the 22 subjects who began the study, 17 completed all feeding periods. INTERVENTIONS: Fermented soy product (112 g tempeh) or unfermented soy (125 g soybean pieces) was consumed during each controlled feeding period. MAIN OUTCOME MEASURE: Urine samples collected while subjects consumed their habitual diets and on the last 3 days of each feeding period were analyzed for isoflavonoid and lignan content by isotope dilution gas chromatography-mass spectrometry. STATISTICAL ANALYSIS PERFORMED: Comparisons of isoflavonoid and lignan excretion were analyzed using the general linear model procedure. Orthogonal contrasts were used to determine treatment differences of interest. RESULTS: Urinary excretion of isoflavonoids (equol, O-desmethylangolensin [O-DMA], daidzein, genistein) was higher and excretion of lignans (enterodiol, enterolactone) was lower when subjects consumed soy-supplemented diets than when they consumed their habitual diets (P < .05). Urinary isoflavonoid excretion and lignan excretion were similar when subjects consumed tempeh and soybean pieces diets; however, recovery of daidzein and genistein was significantly higher when subjects consumed the tempeh diet than when they consumed the soybean pieces diet (P < .002). When fed soy, 5 of 17 subjects excreted high amounts of equol. These five subjects tended to excrete less O-DMA and daidzein than the 12 subjects who excreted low amounts of equol (P < .06). CONCLUSIONS: Fermentation of soy decreased the isoflavone content of the product fed but increased the urinary isoflavonoid recovery. This finding suggests that fermentation increases availability of isoflavones in soy.


Assuntos
Estrogênios não Esteroides/urina , Manipulação de Alimentos , Glycine max , Lignanas/urina , 4-Butirolactona/análogos & derivados , 4-Butirolactona/urina , Adulto , Cromanos/urina , Estudos Cross-Over , Defecação , Dieta , Equol , Estrogênios/urina , Fermentação , Genisteína , Humanos , Isoflavonas/análise , Isoflavonas/urina , Masculino , Fitoestrógenos , Preparações de Plantas , Glycine max/química , Paladar
20.
J Am Diet Assoc ; 95(7): 769-74, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7797807

RESUMO

OBJECTIVE: To compare the effect of vegetable, fruit, and legume consumption on urinary isoflavonoid phytoestrogen and lignan excretion. DESIGN: After 4 days of data collection, during which subjects consumed their habitual diets, subjects were randomly placed on four 9-day controlled experimental diets with each subject receiving each diet in a random order. SUBJECTS: Seven men and three women, aged 20 to 35 years, were recruited from the University of Minnesota Twin Cities community. INTERVENTIONS: All subjects consumed four experimental diets in an assigned random order: a controlled basal diet, a legume/allium diet (containing garbanzo beans, garlic, and onions), and diets low or high in vegetables and fruits (containing apples, pears, potatoes, and carrots). MAIN OUTCOME MEASURES: Urine samples that were collected while subjects consumed their habitual diets and during the last 3 days of each feeding period were analyzed for isoflavonoid and lignan content using isotope dilution gas chromatography-mass spectrometry. STATISTICAL ANALYSIS PERFORMED: The effect of vegetable and fruit intake on urinary isoflavonoid and lignan excretion was analyzed using the general linear model procedure. Post hoc comparisons were made using Duncan's multiple range test. RESULTS: Subjects excreted more of the lignan enterodiol on the high vegetable/fruit diet compared with the basal and legume/allium diets (P = .03); more of the isoflavonoids O-desmethylangolensin (O-DMA), genistein, and sum of isoflavonoids on the legume/allium diet compared with the other controlled diets (P < .05); and more of the isoflavan equol on the basal and legume/allium diets compared with the high vegetable/fruit diet (P < .01). Subjects who excreted higher levels of equol on the basal and legume/allium diets also consumed more of the milk-based pudding provided as part of the controlled diets. CONCLUSIONS: Urinary lignan and isoflavonoid excretion changed in response to alterations in vegetable, fruit, and legume intake under controlled dietary conditions.


Assuntos
Estrogênios não Esteroides/urina , Fabaceae , Frutas , Lignanas/urina , Plantas Medicinais , Verduras , Adulto , Cromanos/urina , Estudos Cross-Over , Dieta , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Fibras na Dieta/administração & dosagem , Ingestão de Energia , Equol , Feminino , Flavonoides/urina , Genisteína , Humanos , Isoflavonas/urina , Masculino , Fitoestrógenos , Preparações de Plantas
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