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1.
Braz J Biol ; 81(4): 1144-1165, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33111929

RESUMEN

Although currently there is already a set of studies regarding ecological aspects of some particular reptile and amphibian species living in Brazilian sandy coastal plains (including the so-called "restinga" and "campo nativo" habitats), there is comparatively few information on the species composition usually associated to these environments. During 31 years (1988-2019) of herpetological studies carried out in sandy coastal plains environments by our research team of the Laboratory of Vertebrate Ecology (Department of Ecology, Universidade do Estado do Rio de Janeiro, in Rio de Janeiro Brazil) we have surveyed reptile and amphibian communities and performed different studies with similar methods in 70 sites from 10 different states along the Brazilian coast. Our surveys resulted in records of 87 species of reptile (five turtles, two crocodylians, six amphisbaenians, 36 lizards and 39 snakes) from 24 families, and 77 species of anuran amphibians from nine families. We have studied multiple natural history topics for anurans and reptiles which resulted in the publication of some specific ecological studies, especially regarding some species, encompassing population and community ecology, foraging and feeding habits, species activity, thermoregulation, reproduction, use of microhabitats, and parasitism by ecto and endoparasites. Our results along these three decades have also contributed for the description of four new lizard species (Ameivula nativo, Glaucomastix littoralis, G. abaetensis and G. itabaianensis). Our studies constitute an important contribution to the knowledge of the ecology of anuran amphibians and reptiles in these ecosystems, as well as to the conservation of sandy coastal plains environment. The checklist presented in this study, based on our records of sandy coastal plains herpetofauna, provides for many localities along the Brazilian coast, the needed knowledge on species occurrence, including the presence of endemic and/or endangered species, which can be of value for many conservation actions.


Asunto(s)
Ecosistema , Lagartos , Animales , Anuros , Brasil , Arena
2.
J Cell Biol ; 125(4): 893-902, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-7514606

RESUMEN

The protracted absence of muscle activation initiates complex cellular and molecular reactions aimed at restoring functional neuromuscular transmission and preventing degenerative processes. A central aspect of these reactions is the sprouting of intramuscular nerves in the vicinity of inactivated muscle fibers. Sprouts emerging from terminal nerve branches and nodes of Ranvier can reestablish functional contacts with inactive muscle fibers, and this is an essential restorative process in pathological conditions of the neuromuscular system. Due to their rapid upregulation in inactive skeletal muscle fibers and their ability to induce nerve sprouting in adult muscle, insulin-like growth factors (IGFs) are candidate signaling molecules to promote restorative reactions in the neuromuscular system. In this study we have exploited the high affinity and specificity of IGF-binding protein 4 (IGF-BP4) and IGF-BP5 for IGF1 and IGF2 to determine whether these growth factors are involved in the nerve sprouting reaction in paralyzed skeletal muscle. In tissue culture experiments with sensory- and motoneurons we demonstrate that the neurite promoting activity of IGF1 is blocked by IGF-BP4, and that a similar IGF-BP-sensitive activity is detected in muscle extracts from paralyzed, but not from control muscle. In in vivo experiments, we show that local delivery of IGF-BP4 to Botulinum toxin A-paralyzed skeletal muscle effectively prevents nerve sprouting in that muscle. Our findings indicate that muscle IGFs play an essential role in intramuscular nerve sprouting. In addition, these findings suggest that IGFs are major signaling factors from inactivated muscle to promote local restorative reactions, including interstitial cell proliferation and nerve sprouting.


Asunto(s)
Músculos/inervación , Terminaciones Nerviosas/fisiología , Somatomedinas/fisiología , Animales , Proteínas Portadoras/metabolismo , Células Cultivadas , Embrión de Pollo , Humanos , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina , Ratones , Ratones Endogámicos BALB C , Neuronas Motoras/fisiología , Terminaciones Nerviosas/crecimiento & desarrollo , Neuritas , Neuronas Aferentes/fisiología , Parálisis/patología , Transducción de Señal , Solubilidad , Somatomedinas/antagonistas & inhibidores
3.
Science ; 263(5154): 1759-62, 1994 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-7510905

RESUMEN

Fas is an apoptosis-signaling receptor molecule on the surface of a number of cell types. Molecular cloning and nucleotide sequence analysis revealed a human Fas messenger RNA variant capable of encoding a soluble Fas molecule lacking the transmembrane domain because of the deletion of an exon encoding this region. The expression of soluble Fas was confirmed by flow cytometry and immunocytochemical analysis. Supernatants from cells transfected with the variant messenger RNA blocked apoptosis induced by the antibody to Fas. Levels of soluble Fas were elevated in patients with systemic lupus erythematosus, and mice injected with soluble Fas displayed autoimmune features.


Asunto(s)
Antígenos de Superficie/fisiología , Apoptosis , Secuencia de Aminoácidos , Animales , Anticuerpos/inmunología , Antígenos de Superficie/química , Antígenos de Superficie/genética , Antígenos de Superficie/inmunología , Artritis Reumatoide/sangre , Secuencia de Bases , Línea Celular , Membrana Celular/química , Humanos , Lupus Eritematoso Sistémico/sangre , Ratones , Datos de Secuencia Molecular , ARN Mensajero/genética , Solubilidad , Subgrupos de Linfocitos T/inmunología , Transfección , Receptor fas
4.
J Clin Invest ; 91(3): 1129-37, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7680662

RESUMEN

Insulin-like growth factor binding protein-4 (IGFBP-4) is a 24-26-kD protein expressed by a variety of cell types in vivo and in vitro. Treatment of normal adult human fibroblasts with 10 nM insulin-like growth factor II (IGF-II) for 24 h resulted in an 85% decrease in endogenous IGFBP-4, as assessed by Western ligand blot analysis of the conditioned medium. Incubation of human fibroblast-conditioned medium (HFCM) with IGF-II under cell-free conditions led to a similar loss of IGFBP-4. This posttranslationally regulated decrease in IGFBP-4 appeared to be due to a protease in HFCM: (a) It could be prevented with specific protease inhibitors or incubation at 4 degrees C; (b) proteolysis of recombinant human (rh) IGFBP-4 required HFCM; (c) immunoblotting and radiolabeling confirmed cleavage of IGFBP-4 into 18- and 14-kD IGFBP-4 fragments. The protease was specific for IGFBP-4, and was strictly dependent on IGFs for activation. IGF-II was the most effective of the natural and mutant IGFs tested, inducing complete hydrolysis of rhIGFBP-4 at a molar ratio of 0.25:1 (IGF/IGFBP-4). Simian virus 40-transformed adult human fibroblasts also expressed IGFBP-4 and IGFBP-4 protease, as well as an inhibitor of IGFBP-4 proteolysis. In biological studies, intact rhIGFBP-4 potently inhibited IGF-I-stimulated [3H]aminoisobutyric acid uptake, whereas proteolyzed rhIGFBP-4 had no inhibitory effect. In conclusion, these data provide evidence for a novel IGF-dependent IGFBP-4-specific protease that modifies IGFBP-4 structure and function, and indicate a preferential role for IGF-II in its activation. Posttranslational regulation of IGFBP-4 may provide a means for cooperative control of local cell growth by IGF-I and IGF-II.


Asunto(s)
Proteínas Portadoras/genética , Factor II del Crecimiento Similar a la Insulina/farmacología , Factor I del Crecimiento Similar a la Insulina/metabolismo , Procesamiento Proteico-Postraduccional , Virus 40 de los Simios/genética , Adulto , Unión Competitiva , Western Blotting , Proteínas Portadoras/aislamiento & purificación , Proteínas Portadoras/metabolismo , Línea Celular Transformada , Transformación Celular Neoplásica , Células Cultivadas , Medios de Cultivo Condicionados , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Proteína 4 de Unión a Factor de Crecimiento Similar a la Insulina , Factor I del Crecimiento Similar a la Insulina/farmacología , Cinética , Inhibidores de Proteasas/farmacología , Proteínas Recombinantes/farmacología , Piel/efectos de los fármacos , Piel/metabolismo
5.
Cancer Res ; 57(9): 1758-68, 1997 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9135020

RESUMEN

Of six prostatic carcinoma cell lines examined (ALVA31, DU145, JCA1, LNCaP, ND1, and PC3) by flow cytometric analysis, all were found to be positive for Fas antigen. Furthermore, of the prostate tissue specimens studied (six cases), all revealed Fas expression in benign and malignant epithelial cells. The agonistic anti-Fas monoclonal antibody (IPO-4) induced apoptosis in only two of six cell lines investigated, PC3 and ALVA31. PCR analysis indicated that all cell lines expressed normal transmembrane and death domains of Fas antigen. Using Western blot analysis, we found abundant expression of p53 in the cytoplasm of two Fas-resistant cell lines, DU145 and ND1, and did not find p53 in two Fas-sensitive cell lines, PC3 and ALVA31. Western blot and PCR analysis did not show consistent differences between cell lines examined in the expression of Bcl-2, Bcl-X(L), Bcl-X(S), and Bak. In contrast, Bax protein was not detected in two Fas-resistant cell lines, DU145 and ND1. We also showed that three Fas-resistant cell lines, DU145, ND1, and JCA1, expressed CD40, whereas the two Fas-sensitive cell lines, PC3 and ALVA31, were CD40 negative. Fas-sensitive cell lines were transfected with the cDNA encoding CD40, and the CD40-positive transfectant became more resistant to growth inhibition mediated by treatment with TNF-alpha and anti-Fas monoclonal antibody. Treatment with cycloheximide converted the phenotype of resistant cell lines from Fas resistant to Fas sensitive. Moreover, anti-Fas treatment of both resistant and sensitive cell lines induced rapid tyrosine phosphorylation or dephosphorylation of multiple proteins. These results suggest that the apoptotic machinery involved in DNA fragmentation is already in place in Fas-resistant cell lines, and thus, Fas-mediated apoptosis could be a target for therapeutic intervention.


Asunto(s)
Apoptosis , Neoplasias de la Próstata/patología , Receptor fas/fisiología , Reacciones Antígeno-Anticuerpo , Antígenos CD40/genética , Antígenos CD40/metabolismo , División Celular , Cicloheximida/farmacología , Fragmentación del ADN , Citometría de Flujo , Humanos , Masculino , Fosfotirosina/metabolismo , Neoplasias de la Próstata/metabolismo , Proteínas Tirosina Fosfatasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal , Transfección , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/metabolismo , Proteína X Asociada a bcl-2 , Proteína bcl-X
6.
Braz. j. biol ; 81(4): 1144-1165, Oct.-Dec. 2021. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1153445

RESUMEN

Abstract Although currently there is already a set of studies regarding ecological aspects of some particular reptile and amphibian species living in Brazilian sandy coastal plains (including the so-called "restinga" and "campo nativo" habitats), there is comparatively few information on the species composition usually associated to these environments. During 31 years (1988-2019) of herpetological studies carried out in sandy coastal plains environments by our research team of the Laboratory of Vertebrate Ecology (Department of Ecology, Universidade do Estado do Rio de Janeiro, in Rio de Janeiro Brazil) we have surveyed reptile and amphibian communities and performed different studies with similar methods in 70 sites from 10 different states along the Brazilian coast. Our surveys resulted in records of 87 species of reptile (five turtles, two crocodylians, six amphisbaenians, 36 lizards and 39 snakes) from 24 families, and 77 species of anuran amphibians from nine families. We have studied multiple natural history topics for anurans and reptiles which resulted in the publication of some specific ecological studies, especially regarding some species, encompassing population and community ecology, foraging and feeding habits, species activity, thermoregulation, reproduction, use of microhabitats, and parasitism by ecto and endoparasites. Our results along these three decades have also contributed for the description of four new lizard species (Ameivula nativo, Glaucomastix littoralis, G. abaetensis and G. itabaianensis). Our studies constitute an important contribution to the knowledge of the ecology of anuran amphibians and reptiles in these ecosystems, as well as to the conservation of sandy coastal plains environment. The checklist presented in this study, based on our records of sandy coastal plains herpetofauna, provides for many localities along the Brazilian coast, the needed knowledge on species occurrence, including the presence of endemic and/or endangered species, which can be of value for many conservation actions.


Resumo Embora atualmente exista um conjunto de estudos sobre aspectos ecológicos de algumas espécies de répteis e de anfíbios que ocorrem nas planícies costeiras arenosas brasileiras (incluindo os chamados habitats de "restinga" e de "campo nativo"), há relativamente poucas informações sobre a composição de espécies geralmente associada a esses ambientes. Durante 31 anos (1988-2019) de estudos herpetológicos realizados em restingas por nossa equipe de pesquisa do Laboratório de Ecologia de Vertebrados (Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil) nós estudamos comunidades de répteis e de anfíbios e realizamos diferentes estudos com métodos semelhantes em 70 localidades de dez diferentes Estados ao longo da costa brasileira. Nossas pesquisas resultaram em registros de 87 espécies de répteis (cinco tartarugas, dois crocodilianos, seis anfisbênios, 36 lagartos e 39 serpentes) de 24 famílias, e 77 espécies de anfíbios anuros de nove famílias. Estudamos vários tópicos de história natural sobre anuros e répteis, que resultaram na publicação de alguns estudos ecológicos específicos, especialmente em relação a algumas espécies, abrangendo ecologia populacional e de comunidades, forrageamento e dieta, horário de atividade de espécies, termorregulação, reprodução, uso do microhabitat e parasitismo por ecto e endoparasitas. Nossos resultados ao longo dessas três décadas também contribuíram para a descrição de quatro novas espécies de lagartos (Ameivula nativo, Glaucomastix littoralis, G. abaetensis e G. itabaianensis). Nossos estudos constituem uma importante contribuição para o conhecimento da ecologia de répteis e de anfíbios anuros nesses ecossistemas, bem como para a conservação dos ecossistemas de restinga. A lista de espécies apresentada neste estudo, com base em nossos registros de herpetofauna das planícies costeiras arenosas, fornece para muitas localidades ao longo da costa brasileira o conhecimento necessário sobre a ocorrência de espécies, incluindo a presença de espécies endêmicas e/ ou ameaçadas de extinção, que podem ser úteis para muitas ações de conservação.


Asunto(s)
Animales , Ecosistema , Lagartos , Anuros , Brasil , Arena
7.
Braz J Biol ; 75(2): 261-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26132005

RESUMEN

In general, anurans tend to be nocturnal, though diurnal activity is characteristic of some groups. Studies show that frog activity may be inferred based on the number of individuals collected at different periods of the day, during large-scale field surveys. We investigated the best period of the day to conduct amphibian sampling in nine Atlantic Rainforest areas in southeastern Brazil, based on intensive field surveys. At each locality we employed similar sampling effort during diurnal, crepuscular and nocturnal searches (totaling 704.5 sampling hours). We pooled data from all localities for each period and estimated the proportion of frogs of each species active at each period based on the total number of individuals and on the number of species found during all surveys for that period. We recorded a total of 817 individual frogs from 69 species. Species richness was highest at night (median = 12 species), intermediate at dusk (median = 8), and lowest during the day (median = 4). The percentage of the total number of individual frogs found (pooled species) was highest during the night (ca. 53%) and lowest during the day (ca. 14%). Analyzing each species separately, the number of individuals recorded was consistently higher at dusk and night for most species. Our study evidences a trend for nocturnal activity for most Atlantic Rainforest frogs, with few species having primarily diurnal habits. Those results may favor future studies and conservation efforts for amphibian species.


Asunto(s)
Anuros/fisiología , Conducta Animal/fisiología , Biodiversidad , Ritmo Circadiano/fisiología , Animales , Anuros/clasificación , Brasil , Bosques , Densidad de Población
8.
J Bone Miner Res ; 9(1): 111-7, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7512304

RESUMEN

Insulin-like growth factor binding protein 4 (IGFBP-4) is secreted by normal human osteoblast-like cells (hOB) and is a potent inhibitor of insulin-like growth factor (IGF) action in vitro. In previous studies, IGF treatment of hOB in culture led to markedly reduced medium levels of IGFBP-4 as detected by western ligand blotting. In the present study, incubation of hOB-conditioned medium (hOB-CM) with IGF under cell-free conditions resulted in a similar loss of IGFBP-4. Both IGF-I and IGF-II were capable of inducing a decrease in IGFBP-4; however, IGF-II was more effective. When the six characterized IGFBP were added to hOB-CM, only IGFBP-4 disappeared in response to IGF-II addition. This IGF-regulated loss of IGFBP-4 was inhibited by metalloproteinase inhibitors and appeared to be due to a proteinase that cleaved IGFBP-4 in 18 and 14 kD fragments identified by western immunoblotting. Conditioned media from eight of eight different donor hOB lines tested exhibited IGFBP-4 proteinase activity. To assess the biologic consequences of IGF-II-induced IGFBP-4 proteolysis, we treated hOB with IGF-II for 5 h, which decreased medium IGF-BP-4 by 70%, and then measured IGF-I and insulin stimulation of [3H]thymidine incorporation. IGF-II itself was not mitogenic and had no effect on insulin-stimulated [3H]thymidine incorporation. However, pretreatment of cultured hOB with IGF-II enhanced IGF-I-stimulated [3H]thymidine incorporation threefold.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Proteínas Portadoras/metabolismo , Metaloendopeptidasas/metabolismo , Osteoblastos/metabolismo , Adulto , Western Blotting , Células Cultivadas , Medios de Cultivo Condicionados , Electroforesis en Gel de Poliacrilamida , Femenino , Hormona del Crecimiento/farmacología , Humanos , Insulina/farmacología , Proteína 4 de Unión a Factor de Crecimiento Similar a la Insulina , Factor I del Crecimiento Similar a la Insulina/farmacología , Factor II del Crecimiento Similar a la Insulina/farmacología , Ligandos , Masculino , Osteoblastos/efectos de los fármacos , Proteína Plasmática A Asociada al Embarazo , Proteínas Recombinantes/farmacología , Somatomedinas/metabolismo
9.
Endocrinology ; 141(1): 454-7, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10614670

RESUMEN

Like insulin-like growth factor binding protein-3 (IGFBP-3), IGFBP-5 forms a ternary complex with insulin-like growth factor (IGF)-I or IGF-II, and the acid-labile subunit (ALS). The study of IGFBP-5/IGFBP-6 chimeric proteins with amino-terminal and middle domain swaps, has revealed the existence of a site in the middle domain of IGFBP-5, that binds to ALS in the absence of the IGFBP-5 carboxy-terminal domain. An IGFBP-6 chimeric protein containing the central domain of IGFBP-5 complexed efficiently with ALS, and a carboxy-terminally truncated IGFBP-5 mutant, IGFBP-5'(1-169), also bound to ALS in the presence of IGFs, although with much less potency than full length rhIGFBP-5. In contrast to the latter, IGFBP-5(1-169) preferentially formed ternary complexes with IGF-II rather than IGF-I. These results indicate that a site which binds ALS exists in IGFBP-5 mutants which lack the IGFBP-5 carboxy-terminal domain.


Asunto(s)
Proteínas Portadoras/química , Glicoproteínas/química , Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina/química , Somatomedinas/química , Sitios de Unión , Unión Competitiva , Proteínas Portadoras/genética , Reactivos de Enlaces Cruzados , Electroforesis en Gel de Poliacrilamida , Glicoproteínas/genética , Humanos , Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina/química , Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/química , Factor II del Crecimiento Similar a la Insulina/química , Pruebas de Precipitina , Proteínas Recombinantes/química , Tinción con Nitrato de Plata , Somatomedinas/genética
10.
Endocrinology ; 132(6): 2507-12, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7684977

RESUMEN

Most but not all of the established insulin-like growth factor-binding proteins (IGFBPs) are expressed in the rat ovary. To continue the process of characterizing these ovarian IGFBPs, a solution hybridization/RNase protection assay was used to study IGFBP-6 gene expression, cellular localization, and hormonal regulation in the immature rat ovary. Total RNA was hybridized with a 458-base long 32P-labeled rat IGFBP-6 cRNA. A single protected fragment (380 bases long) corresponding to IGFBP-6 transcripts was identified in RNA from ovary and lung, but not kidney or liver. The amount of IGFBP-6 transcripts was higher in ovaries from immature rats (25-28 days old) than in ovaries from adult rats and was higher in theca-interstitial than in granulosa cell preparations. Hypophysectomy resulted in a significant (P < 0.05) 2.3 +/- 0.7-fold (mean +/- SD) increase in whole ovarian IGFBP-6 transcripts. This suggests that ovarian IGFBP-6 gene expression is subject to inhibition by one or more pituitary hormones. Therefore, the effect of replacement of FSH, GH, diethylstilbestrol (DES), or combinations thereof was evaluated. Treatment with FSH resulted in a 2.4-fold decrease (P < 0.05) in the abundance of ovarian IGFBP-6 transcripts relative to that in hypophysectomized controls. Provision of DES yielded comparable results. Moreover, the combined provision of FSH and DES resulted in a synergistic decrease (6.0-fold) in ovarian IGFBP-6 transcripts. In contrast, treatment of hypophysectomized rats with GH proved without effect. However, treatment with FSH or DES in addition to GH resulted in a decrease in ovarian IGFBP-6 transcripts (3.9- and 2.7-fold, respectively). To assess the role of ovarian IGFBP-6, its influence on gonadotropin action in primary cultures of rat granulosa cells was also studied. Increasing concentrations (0.01-1 micrograms/ml) of recombinantly expressed human IGFBP-6 did not inhibit the FSH-supported accumulation of either progesterone or estradiol. These findings 1) establish the theca-interstitial compartment of the immature rat ovary as a prominent site of IGFBP-6 gene expression, 2) implicate FSH and DES as inhibitors of IGFBP-6 transcript levels in the whole ovary, 3) and disclose the limited antigonadotropic action of IGBP-6F on the rat granulosa cell.


Asunto(s)
Proteínas Portadoras/metabolismo , Gonadotropinas/antagonistas & inhibidores , Hormonas/fisiología , Ovario/metabolismo , Células Tecales/metabolismo , Animales , Secuencia de Bases , Proteínas Portadoras/genética , Femenino , Expresión Génica , Células de la Granulosa/metabolismo , Hormonas/farmacología , Hipofisectomía , Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina , Sondas Moleculares/genética , Datos de Secuencia Molecular , Ovario/citología , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Ratas , Somatomedinas/metabolismo
11.
J Clin Endocrinol Metab ; 76(5): 1153-9, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-7684391

RESUMEN

U-2 human osteosarcoma cells secrete a 29/32/34 kilodalton (kDa) insulin-like growth factor binding protein (IGFBP) identified as O-glycosylated IGFBP-5. Treatment of U-2 cells with IGF-I markedly increased medium levels of IGFBP-5 in a concentration- and time-dependent manner; other skeletal regulatory factors (GH, insulin, PTH, dexamethasone, beta-estradiol, 1,25-dihydroxyvitamin D3, transforming growth factor-beta) had no effect. IGF-I increased IGFBP-5 levels in the culture medium 10-fold without influencing IGFBP-5 messenger RNA abundance. IGF-I, IGF-II, and the IGF-I analog [1-27Gly(4)38-70] IGF-I bound IGFBP-5 with high affinity and, when added to U-2 cultures, effectively promoted IGFBP-5 accumulation in the medium. On the other hand, des(1-3)IGF-I and [QAYL]IGF-I, IGF-I analogs that did not bind IGFBP-5, failed to elicit an increase in medium IGFBP-5. Cell-free incubation of recombinant human (rh) IGFBP-5 in U-2 conditioned medium resulted in a marked reduction of detectable rhIGFBP-5; the presence of IGF-I or IGF-II peptide partially prevented this decrease. By immunoblot analysis, loss of intact rhIGFBP-5 (29-kDa unreduced, 34-kDa reduced) coincided with the appearance of a 16-kDa proteolytic fragment. U-2 conditioned medium contained immunoreactive IGFBP-5 at 29-34-kDa, 20-kDa, 17-kDa, and 16-kDa. Endogenous IGFBP-5 inhibited IGF-I but not des(1-3)IGF-I-stimulated U-2 cell proliferation. In conclusion, IGF peptides can regulate the availability of IGFBP-5 in osteoblast-like cells by impeding IGFBP-5 proteolysis. The biological consequence of increased medium IGFBP-5 appears to be decreased cell responsiveness to IGF-I stimulation.


Asunto(s)
Proteínas Portadoras/metabolismo , Osteoblastos/metabolismo , Northern Blotting , Western Blotting , Relación Dosis-Respuesta a Droga , Humanos , Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina , Factor I del Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/farmacología , Factor II del Crecimiento Similar a la Insulina/metabolismo , Factor II del Crecimiento Similar a la Insulina/farmacología , Pruebas de Precipitina , Somatomedinas/metabolismo , Células Tumorales Cultivadas
12.
Gene ; 211(1): 87-94, 1998 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-9573342

RESUMEN

The Bcl-2 homologue, Bak, is a potent inducer of apoptosis. FISH data presented here located the gene to 6p21.3. Mapping was consistent with its location centromeric of the HSET locus and approximately 400kb from the MHC. The construction of a contig of genomic clones across the locus facilitated the sequencing of a PAC containing the gene. Comparison of the gene structure to functional and physical domains revealed a good agreement between the physical structure and the intron-exon organisation. The position of a single intron was conserved in comparison to other members of the Bcl-2 family, namely Bax, CED-9, Bcl-X and Bcl-2, but all other introns were displaced, consistent with a divergent phylogeny.


Asunto(s)
Proteínas de la Membrana/química , Secuencia de Aminoácidos , Apoptosis/fisiología , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Humanos Par 6/genética , Clonación Molecular , Evolución Molecular , Genes bcl-2/genética , Humanos , Hibridación Fluorescente in Situ , Complejo Mayor de Histocompatibilidad/genética , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Proteína Destructora del Antagonista Homólogo bcl-2
13.
Mol Biochem Parasitol ; 50(2): 325-33, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1371329

RESUMEN

Molecular cloning and structure analysis of the gene encoding the Pv200 protein of the Sal-1 strain of Plasmodium vivax revealed an overall identity of 34-37% when the deduced amino acid sequence was compared with the sequences of various major merozoite surface antigens of Plasmodium falciparum, Plasmodium yoelii and Plasmodium chabaudi. When the Sal-1 Pv200 sequence was compared with the corresponding sequence from the Belèm strain of P. vivax, it was found that the two merozoite surface antigens were relatively well conserved with an overall amino acid sequence identity of 81%. A region of 23 repeated glutamine residues, found in the sequence of the Belèm isolate was not found, however, in the Sal-1 sequence. Amino- and carboxy-terminal domains of the Pv200 protein were expressed in the yeast Saccharomyces cerevisiae. Each recombinant protein was shown to react with antibodies in sera from splenectomized Bolivian Saimiri monkeys that had been infected previously with P. vivax, and in human sera from individuals with a history of exposure to vivax malaria. The availability of recombinant DNA-derived Pv200 proteins will now allow a full assessment of their utility in the diagnosis and immunoprophylaxis of the benign tertian malaria associated with P. vivax infection.


Asunto(s)
Antígenos de Protozoos/genética , Antígenos de Superficie/genética , Plasmodium vivax/genética , Secuencia de Aminoácidos , Animales , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/química , Antígenos de Protozoos/inmunología , Antígenos de Protozoos/aislamiento & purificación , Antígenos de Superficie/química , Antígenos de Superficie/inmunología , Antígenos de Superficie/aislamiento & purificación , Aotus trivirgatus , Secuencia de Bases , Clonación Molecular , ADN Protozoario/genética , Epítopos , Expresión Génica , Biblioteca Genómica , Humanos , Malaria Falciparum/inmunología , Datos de Secuencia Molecular , Plasmodium vivax/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa , Mapeo Restrictivo , Saccharomyces cerevisiae/genética , Homología de Secuencia de Ácido Nucleico
14.
Mol Biochem Parasitol ; 78(1-2): 55-65, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8813677

RESUMEN

Polymerase chain reaction (PCR) primers based on the cysteine proteinase-like active site regions of the Plasmodium falciparum serine repeat antigen (SERA) were used to identify related sequences within the genome of P. vivax. Molecular cloning and sequence analysis of approximately 25 kb of P. vivax genomic DNA revealed a cluster of five repeated SERA-like genes (V-SERA-1-5), each encoding a cysteine proteinase-related protein. In addition to DNA sequence homology, significant similarities in deduced intron/exon organizations were also observed. The characteristic polyserine sequence found in SERA was not present in any of the deduced V-SERA sequences. Instead, in this region of the five genes, considerable sequence differences were found, suggesting the potential for antigenic variation in the V-SERA molecules. In common with SERA, however, the codon at the position corresponding to the active site cysteine residue of active mammalian and plant cysteinyl proteinases was found to be that of a serine residue in each of the V-SERA genes. Furthermore, in four of the five genes, including the expressed V-SERA-5 gene, the codon for the active site histidine residue was changed to that of a leucine residue. These critical differences reinforce the concept that a biological activity other than proteolysis is likely to be the primary function of the proteins encoded by this family of genes.


Asunto(s)
Antígenos de Protozoos/genética , Genes Protozoarios , Plasmodium vivax/genética , Plasmodium vivax/inmunología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Cartilla de ADN/genética , ADN Complementario/genética , ADN Protozoario/genética , Datos de Secuencia Molecular , Familia de Multigenes , Plasmodium vivax/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo Restrictivo , Homología de Secuencia de Aminoácido
15.
J Histochem Cytochem ; 45(12): 1697-706, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9389773

RESUMEN

The tumor suppressor maspin (mammary serpin) was originally identified as a component of human mammary epithelial cells that is downregulated as mammary tumor cells progress from the benign to the invasive and metastatic states. Maspin inhibits cellular invasion, motility, and proliferation, but its mechanism of action is currently unknown. Because the cellular machinery responsible for these processes is cytoplasmic, we have reexamined the tissue distribution and subcellular localization of maspin. We find that maspin, or a maspin-like protein, is present in many human organs, in which it localizes to epithelia. In cultured human mammary myoepithelial cells, maspin is predominantly a soluble cytoplasmic protein that associates with secretory vesicles and is present at the cell surface. In vitro assays show that the vesicle association is due to the existence of an uncleaved facultative secretion signal that allows small amounts of maspin to partition into the endoplasmic reticulum. These results demonstrate that maspin is more widespread than previously believed. The subcellular localization studies indicate that soluble intracellular and vesicle-associated maspin probably play an important role in controlling the invasion, motility, and proliferation of cells expressing it, whereas extracellular maspin may also regulate these processes in adjacent cells.


Asunto(s)
Gránulos Citoplasmáticos/metabolismo , Genes Supresores de Tumor , Proteínas de la Membrana/metabolismo , Proteínas/metabolismo , Serpinas/metabolismo , Northern Blotting , Mama/metabolismo , Células Cultivadas , Citoplasma/metabolismo , Cartilla de ADN/química , Epitelio/metabolismo , Femenino , Humanos , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Masculino , Proteínas/genética , Proteínas/inmunología , ARN Mensajero/metabolismo , Serpinas/genética , Serpinas/inmunología , Fracciones Subcelulares/metabolismo , Distribución Tisular , Células Tumorales Cultivadas
16.
DNA Cell Biol ; 10(10): 757-69, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1741956

RESUMEN

A cDNA encoding a novel human subtilisin-like protease was identified by a polymerase chain reaction (PCR) methodology. PCR primers were designed to be specific for the subfamily of eukaryotic subtilisin-like proteases with specificity for paried basic amino acid residue processing motifs. The gene encoding this protease, designated PACE4, also encoded a smaller subtilisin-related polypeptide derived by alternate mRNA splicing. The deduced PACE4 protein sequence contained a number of interesting features not present in other family members, including an extended signal peptide region, and a relatively large carboxyl-terminal cysteine-rich region with no obvious membrane anchor sequence. As with the fur gene product, the tissue distribution of PACE4 was widespread, with comparatively higher levels in the liver. An additional relationship to the fur gene product was shown by chromosomal localization studies. The close proximity of the fur and PACE4 genes on chromosome 15 suggests that these genes probably evolved from a common ancestor by gene duplication.


Asunto(s)
Cromosomas Humanos Par 15/ultraestructura , Proteínas Tirosina Quinasas , Proteínas Proto-Oncogénicas/genética , ARN Mensajero/análisis , Subtilisinas/genética , Secuencia de Aminoácidos , Células Cultivadas , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas/análisis , Proteínas Proto-Oncogénicas c-fes
17.
DNA Cell Biol ; 10(5): 319-28, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1713771

RESUMEN

A cDNA encoding the human fur gene product was isolated from a human hepatoma cell line. The cDNA encodes a protein with significant amino acid sequence identity to the prokaryotic subtilisin family of serine proteases. More extensive sequence identity was found when the protein was compared with eukaryotic proteases such as PRB1 of Saccharomyces cerevisiae, and with PC2 and PC3, the only other known mammalian subtilisin-like proteases. In contrast to these proteins, however, the fur gene product shares a more extensive topographic and functional homology with the KEX2 endoprotease of S. cerevisiae. Each protease contains a signal peptide, a glycosylated extra cytoplasmic domain, a hydrophobic membrane-spanning region, and a short, hydrophilic "tail" sequence. As with KEX2, the expressed human protease was shown to cleave mammalian proproteins at their paired basic amino acid processing sites. We have, therefore, proposed the function-based acronym PACE (paired basic amino acid cleaving enzyme) for this prototypic mammalian proprotein processing enzyme.


Asunto(s)
Endopeptidasas/genética , Genes , Subtilisinas/genética , Secuencia de Aminoácidos , Aminoácidos Diaminos , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , Carcinoma Hepatocelular , Línea Celular , Clonación Molecular , ADN/genética , Exones , Humanos , Intrones , Neoplasias Hepáticas , Datos de Secuencia Molecular , Poli A/genética , Poli A/aislamiento & purificación , ARN/genética , ARN/aislamiento & purificación , Empalme del ARN , ARN Mensajero , Mapeo Restrictivo , Saccharomyces cerevisiae/genética , Homología de Secuencia de Ácido Nucleico
18.
Ann N Y Acad Sci ; 638: 167-76, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1664683

RESUMEN

Two distinct classes of cell surface FGF-binding proteins have been identified. These receptors differ in both mode of interaction and in affinity for the FGFs. cDNAs that encode the low-affinity receptor were isolated from a hamster kidney cell line cDNA library by expression cloning. Transfected cells that contained these heparan sulfate proteoglycan FGF receptor cDNAs were enriched for by panning on basic FGF-coated plates. The analogous human cDNA was isolated from a hepatoma cell line cDNA library. The homology of our hamster cDNAs to the previously described murine integral membrane proteoglycan syndecan, together with an exact amino acid sequence match of our human-cDNA-encoded product to human syndecan, clearly indicates the identity of these independently isolated proteoglycans. Further confirmation that the expressed molecule serves as a proteoglycan core protein was achieved by immunoprecipitation of 35SO4-labeled material from solubilized transfected cells. Nitrous acid treatment and chondroitinase digestion revealed that 77% of the label was associated with heparan sulfate chains and 22% with chondroitin sulfate chains. These heparan sulfate chains contributed to the fivefold increase in the total heparan sulfate found to be present on the surface of the transfected cells compared with cells transfected with a vector lacking the cDNA insert.


Asunto(s)
Heparitina Sulfato/genética , Proteoglicanos/genética , Receptores de Superficie Celular/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Cricetinae , ADN/genética , Proteoglicanos de Heparán Sulfato , Heparitina Sulfato/metabolismo , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Datos de Secuencia Molecular , Proteoglicanos/metabolismo , Receptores de Superficie Celular/química , Receptores de Factores de Crecimiento de Fibroblastos , Alineación de Secuencia , Sindecanos
19.
Braz J Biol ; 74(2): 349-54, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-25166319

RESUMEN

Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia) and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the "Nestedness Temperature Calculator" to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species) whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island). Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P <0.00001; 5000 randomisations; randomisation temperature = 51.45° ± 7.18° SD), indicating that lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.


Asunto(s)
Ecosistema , Lagartos/clasificación , Animales , Biodiversidad , Brasil , Densidad de Población , Temperatura
20.
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467521

RESUMEN

Abstract Although currently there is already a set of studies regarding ecological aspects of some particular reptile and amphibian species living in Brazilian sandy coastal plains (including the so-called restinga and campo nativo habitats), there is comparatively few information on the species composition usually associated to these environments. During 31 years (1988-2019) of herpetological studies carried out in sandy coastal plains environments by our research team of the Laboratory of Vertebrate Ecology (Department of Ecology, Universidade do Estado do Rio de Janeiro, in Rio de Janeiro Brazil) we have surveyed reptile and amphibian communities and performed different studies with similar methods in 70 sites from 10 different states along the Brazilian coast. Our surveys resulted in records of 87 species of reptile (five turtles, two crocodylians, six amphisbaenians, 36 lizards and 39 snakes) from 24 families, and 77 species of anuran amphibians from nine families. We have studied multiple natural history topics for anurans and reptiles which resulted in the publication of some specific ecological studies, especially regarding some species, encompassing population and community ecology, foraging and feeding habits, species activity, thermoregulation, reproduction, use of microhabitats, and parasitism by ecto and endoparasites. Our results along these three decades have also contributed for the description of four new lizard species (Ameivula nativo, Glaucomastix littoralis, G. abaetensis and G. itabaianensis). Our studies constitute an important contribution to the knowledge of the ecology of anuran amphibians and reptiles in these ecosystems, as well as to the conservation of sandy coastal plains environment. The checklist presented in this study, based on our records of sandy coastal plains herpetofauna, provides for many localities along the Brazilian coast, the needed knowledge on species occurrence, including the presence of endemic and/or endangered species, which can be of value for many conservation actions.


Resumo Embora atualmente exista um conjunto de estudos sobre aspectos ecológicos de algumas espécies de répteis e de anfíbios que ocorrem nas planícies costeiras arenosas brasileiras (incluindo os chamados habitats de restinga e de campo nativo), há relativamente poucas informações sobre a composição de espécies geralmente associada a esses ambientes. Durante 31 anos (1988-2019) de estudos herpetológicos realizados em restingas por nossa equipe de pesquisa do Laboratório de Ecologia de Vertebrados (Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil) nós estudamos comunidades de répteis e de anfíbios e realizamos diferentes estudos com métodos semelhantes em 70 localidades de dez diferentes Estados ao longo da costa brasileira. Nossas pesquisas resultaram em registros de 87 espécies de répteis (cinco tartarugas, dois crocodilianos, seis anfisbênios, 36 lagartos e 39 serpentes) de 24 famílias, e 77 espécies de anfíbios anuros de nove famílias. Estudamos vários tópicos de história natural sobre anuros e répteis, que resultaram na publicação de alguns estudos ecológicos específicos, especialmente em relação a algumas espécies, abrangendo ecologia populacional e de comunidades, forrageamento e dieta, horário de atividade de espécies, termorregulação, reprodução, uso do microhabitat e parasitismo por ecto e endoparasitas. Nossos resultados ao longo dessas três décadas também contribuíram para a descrição de quatro novas espécies de lagartos (Ameivula nativo, Glaucomastix littoralis, G. abaetensis e G. itabaianensis). Nossos estudos constituem uma importante contribuição para o conhecimento da ecologia de répteis e de anfíbios anuros nesses ecossistemas, bem como para a conservação dos ecossistemas de restinga. A lista de espécies apresentada neste estudo, com base em nossos registros de herpetofauna das planícies costeiras arenosas, fornece para muitas localidades ao longo da costa brasileira o conhecimento necessário sobre a ocorrência de espécies, incluindo a presença de espécies endêmicas e/ ou ameaçadas de extinção, que podem ser úteis para muitas ações de conservação.

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