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1.
Mult Scler Relat Disord ; 25: 276-281, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30170267

RESUMO

BACKGROUND: Despite a recent interest in Real World Data, such studies are scarce in multiple sclerosis (MS) disease. The objective was to describe the patients, disease progression and use of DMDs in France and compare clinical effectiveness of first-line injectable DMDs. METHODS: We conducted a retrospective multicenter study in France, using data collected by 11 expert centers with the EDMUS software. RESULTS: Overall, 15,039 French MS patients were followed for a mean of 11.5 years. Mean age at start of disease was 32 years and 74% were women. After the disease onset, median time to reach EDSS 3 was 11 years and 51.8% of patients were relapse-free 2 years after the disease's onset. The mean delay between onset of disease and initiation of treatment was 5.7 ±â€¯6.9 years. Over time, it decreased from 8.8 ±â€¯7.8 to 0.7 ±â€¯0.7 years for initiation of treatment before 2000 vs. after 2010, respectively. Two years after the initiation of treatment, the persistence rate of injectable disease modifying drugs (DMDs) was 60.7%. The effectiveness of these drugs were quite similar. CONCLUSION: This study brings new insight on the natural history of MS and the use and effectiveness of injectable DMDs in this condition.


Assuntos
Gerenciamento Clínico , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/terapia , Resultado do Tratamento , Adolescente , Adulto , Distribuição por Idade , Estudos de Coortes , Avaliação da Deficiência , Progressão da Doença , Feminino , França/epidemiologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Adulto Jovem
2.
JIMD Rep ; 20: 45-55, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25626710

RESUMO

Intellectual disability (ID), which affects around 2-3% of the general population, is classically divided into syndromic and nonsyndromic forms, with several modes of inheritance. Nonsyndromic autosomal recessive ID (NS-ARID) appears extremely heterogeneous with numerous genes identified to date, including inborn errors of metabolism. The TUSC3 gene encodes a subunit of the endoplasmic reticulum (ER)-bound oligosaccharyltransferase complex, which mediates a key step of N-glycosylation. To date, only five families with NS-ARID and TUSC3 mutations or rearrangements have been reported in the literature. All patients had speech delay, moderate-to-severe ID, and moderate facial dysmorphism. Microcephaly was noted in one third of patients, as was short stature. No patients had congenital malformation except one patient with unilateral cryptorchidism. Glycosylation analyses of patients' fibroblasts showed normal N-glycan synthesis and transfer. We present a review of the 19 patients previously described in the literature and report on a sixth consanguineous family including two affected sibs, with intellectual disability, unspecific dysmorphic features, and no additional malformations identified by high-resolution array-CGH. A homozygous truncating intragenic duplication of the TUSC3 gene leading to an aberrant transcript was detected in two siblings. This observation, which is the first reported case of TUSC3 homozygous duplication, confirms the implication of TUSC3 in NS-ARID and the power of the high-resolution array-CGH in identifying intragenic rearrangements of genes implicated in nonsyndromic ID and rare diseases.

3.
Clin Genet ; 85(3): 233-44, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23489061

RESUMO

Small supernumerary marker chromosomes (sSMCs) are structurally abnormal chromosomes that cannot be characterized by karyotype. In many prenatal cases of de novo sSMC, the outcome of pregnancy is difficult to predict because the euchromatin content is unclear. This study aimed to determine the presence or absence of euchromatin material of 39 de novo prenatally ascertained sSMC by array-comparative genomic hybridization (array-CGH) or single nucleotide polymorphism (SNP) array. Cases were prospectively ascertained from the study of 65,000 prenatal samples [0.060%; 95% confidence interval (CI), 0.042-0.082]. Array-CGH showed that 22 markers were derived from non-acrocentric markers (56.4%) and 7 from acrocentic markers (18%). The 10 additional cases remained unidentified (25.6%), but 7 of 10 could be further identified using fluorescence in situ hybridization; 69% of de novo sSMC contained euchromatin material, 95.4% of which for non-acrocentric markers. Some sSMC containing euchromatin had a normal phenotype (31% for non-acrocentric and 75% for acrocentric markers). Statistical differences between normal and abnormal phenotypes were shown for the size of the euchromatin material (more or less than 1 Mb, p = 0.0006) and number of genes (more or less than 10, p = 0.0009). This study is the largest to date and shows the utility of array-CGH or SNP array in the detection and characterization of de novo sSMC in a prenatal context.


Assuntos
Aberrações Cromossômicas , Aconselhamento Genético , Predisposição Genética para Doença , Prognóstico , Adulto , Hibridização Genômica Comparativa , Feminino , França , Estudos de Associação Genética , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Humanos , Hibridização in Situ Fluorescente , Cariótipo , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Gravidez , Diagnóstico Pré-Natal , Estudos Prospectivos , Risco , Suíça , Adulto Jovem
4.
Clin Genet ; 84(6): 507-21, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23506379

RESUMO

The association of marfanoid habitus (MH) and intellectual disability (ID) has been reported in the literature, with overlapping presentations and genetic heterogeneity. A hundred patients (71 males and 29 females) with a MH and ID were recruited. Custom-designed 244K array-CGH (Agilent®; Agilent Technologies Inc., Santa Clara, CA) and MED12, ZDHHC9, UPF3B, FBN1, TGFBR1 and TGFBR2 sequencing analyses were performed. Eighty patients could be classified as isolated MH and ID: 12 chromosomal imbalances, 1 FBN1 mutation and 1 possibly pathogenic MED12 mutation were found (17%). Twenty patients could be classified as ID with other extra-skeletal features of the Marfan syndrome (MFS) spectrum: 4 pathogenic FBN1 mutations and 4 chromosomal imbalances were found (2 patients with both FBN1 mutation and chromosomal rearrangement) (29%). These results suggest either that there are more loci with genes yet to be discovered or that MH can also be a relatively non-specific feature of patients with ID. The search for aortic complications is mandatory even if MH is associated with ID since FBN1 mutations or rearrangements were found in some patients. The excess of males is in favour of the involvement of other X-linked genes. Although it was impossible to make a diagnosis in 80% of patients, these results will improve genetic counselling in families.


Assuntos
Testes Genéticos/métodos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Síndrome de Marfan/diagnóstico , Síndrome de Marfan/genética , Adolescente , Adulto , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Análise Citogenética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estudos Prospectivos , Análise de Sequência de DNA , Inativação do Cromossomo X , Adulto Jovem
5.
Clin Genet ; 82(1): 41-7, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21722100

RESUMO

Most microdeletion syndromes identified before the implementation of array-comparative genomic hybridization (array-CGH) were presumed to be well-defined clinical entities. However, the introduction of whole-genome screening led not only to the description of new syndromes but also to the recognition of a broader spectrum of features for well-known syndromes. Here, we report on 10 patients presenting with mental retardation associated with atypical features not suggestive of a known microdeletion and a normal standard karyotype. Array-CGH analyses revealed five microdeletions in the DiGeorge region, three microdeletions in the Williams-Beuren region and two microdeletions in the Smith-Magenis region. Reevaluation in these patients confirmed that the diagnosis remained difficult on clinical grounds and emphasized that well-known genomic disorders can have a phenotype that is heterogeneous and more variable than originally thought. The widespread use of array-CGH shows that such patients may be more readily achieved on the basis of genotype rather than phenotype.


Assuntos
Anormalidades Múltiplas/diagnóstico , Deleção Cromossômica , Cromossomos Humanos Par 22/genética , Cromossomos Humanos Par 7/genética , Deficiência Intelectual/diagnóstico , Anormalidades Múltiplas/genética , Adolescente , Adulto , Pré-Escolar , Hibridização Genômica Comparativa , Genótipo , Humanos , Deficiência Intelectual/genética , Cariótipo , Fenótipo
9.
Rev. gastroenterol. Perú ; 26(4): 377-385, oct.-dic. 2006. ilus, tab, graf
Artigo em Espanhol | LILACS, LIPECS | ID: lil-533798

RESUMO

El cáncer gástrico continúa siendo una de las neoplasias malignas más comunes en el mundo. A pesar de la disminución en la incidencia de esta enfermedad en países desarrollados; Europa del Este, Asia y América Latina muestran la incidencia más alta representaron el 8,6 por ciento de nuevos cánceres en el año 2002. En Lima ha aumentado desde el año 1990 hasta 1997, llegando a tener 24,3/100000 en hombres, y en mujeres 17,6/100000, en el último periodo estudiado, considerándose área de alto riesgo. La mortalidad continúa siendo la primera causa de muerte para ambos sexos, en hombres 19,3/100000 y en mujeres 14,2/100000. La incidencia guarda una relación directamente proporcional con el lugar de origen dentro de Lima Metropolitana, una ciudad de cerca de 8 millones de habitantes, indicando que los distritos que muestran una mayor incidencia son Puente Piedra y Lince seguidos de Villa El Salvador, El Agustino, Breña Rimac, entre otros, que son distritos de un nivel socioeconómico medio bajo; y los que muestran menor incidencia son aquellos que tienen un nivel socioeconómico alto como San Isidro y Miraflores entre otros.


Gastric cancer continues to be one of the most common malignant neoplasias inthe world. Despite the decreasing incidence of this disease in developed countries, Eastern Europe and Latin America show the highest incidences. It accounted for 8.6 per cent of all new cases of cancer in 2002. In Peru it has increased between 1990 and 1997 amounting to 24.3/100000 in men and 17.6/100000 in women, during the last period studied, thus it is considered a high risk area. Mortality: it is still the leading cause of death for both sexes, in men it is 19.3/100000 and in women 14.2/100000. Incidence is directly proportional to the place of origin in Metropolitan Lima, a city of almost 8 million inhabitants, and the districts with the highest incidences are Puente Piedra and Lince followed by Villa El Salvador, El Augustino, Breña and Rimac among others. These are districts with medium-low socioeconomic levels, whereas the lowest incidences are found in districts with high socioeconomic levels, such as San Isidro and Miraflores, among others.


Assuntos
Humanos , Masculino , Adolescente , Adulto , Pessoa de Meia-Idade , Feminino , Incidência , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/etnologia , Neoplasias Gástricas/mortalidade , Mortalidade/estatística & dados numéricos
11.
Cell Mol Biol (Noisy-le-grand) ; 50(7): 861-7, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15672471

RESUMO

Animal and humans studies have shown that supplementation with triacylglycerides containing omega3 fatty acids, mainly docosahexaenoic acid (DHA) and eicosapentaenoic acid, can induce a decrease in arachidonic acid (AA) in blood lipids. Interestingly, we observed in a previous work that a supplementation with DHA enriched eggs in a healthy elderly population induced an accretion of AA in their blood lipids. The present study investigates whether purified DHA enriched egg phospholipids could be responsible for this effect. Four groups of rats were supplemented daily, for eight weeks, with DHA phospholipids (10, 30 or 60 mg/kg) or with soybean phospholipids. Red blood cell membranes and plasma fatty acid levels were compared with that of rats without supplementation. Soybean phospholipids supplementation increased the level of AA in blood lipids but decreased that of DHA. The doses of DHA phospholipids, 30 and 60 mg/kg, induced greater amounts of AA without affecting significantly DHA levels. In contrast, DHA phospholipids supplementation, 10 mg/kg, in which there was the greatest amount of AA, induced only a slight increase in AA levels. Moreover, DHA levels were decreased by this supplementation. These results demonstrate that specific increases in AA levels are preferentially associated with DHA phospholipids levels in supplementation.


Assuntos
Ácido Araquidônico/sangue , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Gema de Ovo , Lipídeos/sangue , Fosfolipídeos/administração & dosagem , Animais , Ácidos Docosa-Hexaenoicos/sangue , Masculino , Ratos , Ratos Sprague-Dawley , Glycine max/química
12.
J Mol Endocrinol ; 31(3): 359-72, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14664700

RESUMO

The angiotensin II (Ang II) type 2 receptor (AT(2)) is a member of the seven-transmembrane domain, G-protein coupled receptor family. This receptor is ubiquitously distributed in the fetus but, in most tIssues, its expression dramatically falls in the first few hours after birth. Based on this observation, the hypothesis that this receptor could be involved in fetal development was raised and, over the past ten Years, many studies have tried to identify a role for the AT(2) receptor using many different tIssues and cell lines. To date, one of the major roles associated with the Ang II AT(2) receptor concerns its ability to induce neuronal differentiation. Indeed, in cells of neuronal origin, activation of the AT(2) receptor was shown to induce neurite outgrowth and elongation, modulate neuronal excitability, promote cellular migration and, in particular conditions, induce neuronal cell death. Regarding its signaling mechanisms, the AT(2) receptor still represents one of the most controversial G-protein coupled receptors since it does not stimulate the production of any of the classical second messengers. This review summarizes knowledge of the functions and the signaling mechanisms involved in the actions of the AT(2) receptor in neurons and cells of neuronal origin. Based on its altered expression in neurological disorders, a role for the AT(2) receptor in control of neuronal plasticity is proposed.


Assuntos
Angiotensina II/metabolismo , Diferenciação Celular/fisiologia , Neurônios/citologia , Receptores de Angiotensina/metabolismo , Animais , Apoptose , Células Cultivadas , Feminino , Feto/citologia , Feto/metabolismo , Humanos , Neurônios/metabolismo , Gravidez , Coelhos , Ratos , Renina/metabolismo , Transdução de Sinais
13.
J Immunol Methods ; 257(1-2): 41-9, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11687237

RESUMO

Endothelial cells derived from the human umbilical vein (HUVEC) are used to study the mechanisms involved in EC response to various stimuli as well as to investigate the basis of pathological conditions of the vascular system such as altered endothelium permeability, tumor-induced angiogenesis, atherosclerosis and leukocyte extravasation in chronic inflammatory responses. However, investigations of gene involvement related to these conditions have progressed slowly because of the difficulty of transfecting HUVEC with high efficiency. Whereas several technical approaches have been described, they usually result in low levels of transfected cells or they require several steps or sophisticated instrumentation. We describe here a straightforward protocol of transfection of freshly isolated HUVEC that is based on the simple technique of electroporation. Efficiencies of gene transfection greater than 40% were routinely obtained by using a combination of optimized conditions of HUVEC isolation, composition of the electroporation medium and homogeneity of the plasmids. The protocol has been applied to the functional transient transfection of functional genes in HUVEC as illustrated in the case of the cDNA encoding GFP, protein kinase C (alpha and epsilon isotypes) and beta-galactosidase.


Assuntos
Eletroporação , Endotélio Vascular/metabolismo , Transfecção , Células Cultivadas , DNA Complementar/administração & dosagem , DNA Complementar/genética , Endotélio Vascular/citologia , Expressão Gênica , Proteínas de Fluorescência Verde , Humanos , Isoenzimas/genética , Proteínas Luminescentes/genética , Proteína Quinase C/genética , beta-Galactosidase/genética
14.
J Clin Endocrinol Metab ; 86(9): 4495-503, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11549699

RESUMO

The aim of the present study was to identify which adenylyl cyclase isoforms were expressed in the human adrenal gland and to determine which isoform(s) may be coupled to ACTH action. Our results indicate that, in both glomerulosa and fasciculata zones, adenylyl cyclase 1 was detected in cells at the membrane level, adenylyl cyclases 3 and 2 in both the cytoplasm and the plasma membrane, whereas adenylyl cyclase 5/6 and adenylyl cyclase 4 were found mainly in cytoplasm. The levels of expression of each isoform were similar between the two adrenocortical zones, except for adenylyl cyclase 5/6, which had a lower level of expression in the zona fasciculata. We next evaluated the role of the various adenylyl cyclase isoforms during ACTH-stimulated cAMP production in both glomerulosa and fasciculata cell preparations. Corroborating with previous observations, we found that calcium had a biphasic effect on cAMP production. Interestingly, pertussis toxin treatment increased cAMP production, indicating that, in addition to Gs, ACTH is coupled to a Gi protein. Incubation with the betagamma-subunit sequestrant peptide QEHA decreased cAMP production, as did incubation with inhibitory antibodies against either adenylyl cyclase 2 or adenylyl cyclase 5/6. Inhibitory adenylyl cyclase 3 antibodies interfered with ACTH action only in the zona fasciculata. Altogether these data indicate that adrenocortical cells express one or two isoforms of each class of adenylyl cyclases and, thus, have the ability to produce cAMP in response to various regulatory, intracellular mediators. Importantly, our results indicate that in the human adrenal gland, ACTH acts mainly through adenylyl cyclase 5/6 and adenylyl cyclase 2/4, whereas the effect of ACTH on adenylyl cyclase 3 activity may be a consequence of calcium influx.


Assuntos
Adenilil Ciclases/biossíntese , Adenilil Ciclases/genética , Glândulas Suprarrenais/enzimologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Toxina Adenilato Ciclase , Córtex Suprarrenal/citologia , Córtex Suprarrenal/enzimologia , Corticosteroides/metabolismo , Glândulas Suprarrenais/citologia , Western Blotting , AMP Cíclico/biossíntese , Humanos , Imuno-Histoquímica , Isoenzimas/biossíntese , Isoenzimas/genética , Membranas/enzimologia , Toxina Pertussis , Fatores de Virulência de Bordetella/farmacologia , Zona Fasciculada/citologia , Zona Fasciculada/enzimologia , Zona Glomerulosa/citologia , Zona Glomerulosa/enzimologia
15.
Biochemistry ; 40(21): 6486-92, 2001 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-11371212

RESUMO

The inositol 1,4,5-trisphosphate (InsP(3)) receptor is a ligand-gated Ca(2+) channel playing an important role in the control of intracellular Ca(2+). In the study presented here, we demonstrate that angiotensin (AngII), phorbol ester (PMA), and FK506 significantly increase the level of InsP(3) receptor phosphorylation in intact bovine adrenal glomerulosa cells. With a back-phosphorylation approach, we showed that the InsP(3) receptor is a good substrate for protein kinase C (PKC) and that FK506 increases the level of PKC-mediated InsP(3) receptor phosphorylation. With a microsomal preparation from bovine adrenal cortex, we showed that PKC enhances the release of Ca(2+) induced by a submaximal dose of InsP(3). We also showed that FK506 blocks intracellular Ca(2+) oscillations in isolated adrenal glomerulosa cells by progressively increasing the intracellular Ca(2+) concentration to a high plateau level. This effect is consistent with an inhibitory role of FK506 on calcineurin dephosphorylation of the InsP(3) receptor, thus keeping the receptor in a phosphorylated, high-conductance state. Our results provide further evidence for the crucial role of the InsP(3) receptor in the regulation of intracellular Ca(2+) oscillations and show that FK506, by maintaining the phosphorylated state of the InsP(3) receptor, causes important changes in the Ca(2+) oscillatory process.


Assuntos
Cálcio/antagonistas & inibidores , Cálcio/metabolismo , Líquido Intracelular/metabolismo , Tacrolimo/farmacologia , Zona Glomerulosa/efeitos dos fármacos , Zona Glomerulosa/metabolismo , Córtex Suprarrenal/citologia , Córtex Suprarrenal/enzimologia , Córtex Suprarrenal/metabolismo , Animais , Inibidores de Calcineurina , Canais de Cálcio/metabolismo , Bovinos , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Citosol/efeitos dos fármacos , Citosol/enzimologia , Citosol/metabolismo , Inibidores Enzimáticos/farmacologia , Inositol 1,4,5-Trifosfato/metabolismo , Receptores de Inositol 1,4,5-Trifosfato , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/enzimologia , Microssomos/enzimologia , Microssomos/metabolismo , Fosforilação/efeitos dos fármacos , Testes de Precipitina , Proteína Quinase C/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Zona Glomerulosa/citologia , Zona Glomerulosa/enzimologia
16.
J Leukoc Biol ; 68(2): 293-300, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10947075

RESUMO

We have treated Jurkat T lymphocytes with a concentration (160 nM) of phorbol myristyl acetate (PMA) that down-regulates conventional and novel protein kinase C (PKC) isozymes and we have investigated the effects on Ca2+ signaling and protein tyrosine phosphorylation using mAb (C305) directed against the beta-subunit of the Ti heterodimer or the epsilon/delta-component of the CD3 complex (mAb Leu 4 or OKT 3). The levels of expression of PKC alpha, betaI, betaII, and delta were reduced by 90% or more in PMA-treated cells, whereas the expression of PKCtheta decreased by approximately 30%. In contrast, the chronic treatment with PMA increased the expression of PKCepsilon and PKCzeta. There was a lack of Ca2+ response and myo-inositol trisphosphate (IP3) production in PMA-treated cells when they were exposed to mAb Leu 4 but the cells responded to mAb C305. The treatment with PMA did not affect the surface expression of Ti or CD3. The overall levels of tyrosine-phosphorylated proteins were markedly reduced in PMA-treated cells. We investigated whether these observations were related to defects in signal transduction related to protein tyrosine kinase (PTK) of the src and syk families. The electrophoretic mobilities of p59(fyn) or ZAP-70 were not changed in PMA-treated cells but p56(Ick) migrated as a large band of M(r) 60-62 kDa. The decreased mobility of p56(Ick) was related to a state of hyperphosphorylation. The activity of modified p56(Ick) was not up-regulated in activated Jurkat cells. Our data suggest that clonotypic Ti can trigger Ca2+ mobilization independently of conventional PKC isoforms. Our observations further suggest that conventional PKC isoforms are involved early in the cascade of events associated with Jurkat T lymphocyte activation.


Assuntos
Complexo CD3/fisiologia , Cálcio/fisiologia , Carcinógenos/farmacologia , Receptores de Antígenos de Linfócitos T/fisiologia , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/fisiologia , Acetato de Tetradecanoilforbol/farmacologia , Humanos , Células Jurkat , Fosforilação , Linfócitos T/efeitos dos fármacos , Tirosina
17.
FEBS Lett ; 476(3): 234-9, 2000 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-10913620

RESUMO

Nuclear ionic channels (NICs) represent ubiquitous structures of living cells, although little is known about their functional properties and encoding genes. To characterize NICs, liver nuclear membrane vesicles were reconstituted into either planar lipid bilayers or proteoliposomes. Reconstitution of nuclear envelope (NE) vesicles into planar lipid bilayer proceeded with low efficiency. NE vesicle reconstitution into proteoliposomes led to NIC observations by the patch-clamp technique. Large conductance, voltage-gated, K(+)-permeant and Cl(-)-permeant NICs were characterized. An 80-105-pS K(+)-permeant NIC with conducting sub-state was also recorded. Our data establish that NICs can be characterized upon reconstitution into giant proteoliposomes and retain biophysical properties consistent with those described for native NICs.


Assuntos
Núcleo Celular/metabolismo , Canais Iônicos/metabolismo , Fígado/metabolismo , Animais , Núcleo Celular/ultraestrutura , Cloretos/metabolismo , Cães , Técnicas In Vitro , Fígado/ultraestrutura , Microscopia Eletrônica , Membrana Nuclear/metabolismo , Membrana Nuclear/ultraestrutura , Potássio/metabolismo , Proteolipídeos , Ratos
18.
Endocrinology ; 141(2): 684-92, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10650950

RESUMO

In the present study, we report that ACTH induces a transient chloride current. The lack of correlation between ACTH-induced cAMP production and amplitude of the Cl- current, as well as the absence of stimulation by forskolin or 8Br-cAMP indicated that the ACTH-induced current was not cAMP-dependent. We explored the possibility that one or several elements of the Ras/Raf MAPK cascade were involved. Indeed, we found that ACTH at 10(-10) M induced activation of Ras. Inhibition of the current by QEHA peptide, a Gbetagamma sequestrant, demonstrated that Gbetagamma subunits transduced the message. Blockage of the Ras activation using an inhibitor of farnesyl transferase (BZA-5B) or the monoclonal antibody H-Ras(259) abrogated the current. Moreover, the addition of Ras-GTPyS in the pipette medium gave rise to the Cl- current. Treatment of the cells with BZA decreased the aldosterone secretion induced by 10(-10) M ACTH but not that induced by 10(-8) M ACTH, confirming the involvement of Ras in steroid secretion. We conclude that ACTH triggers a Cl- current through the activation of the Ras protein by Gbetagamma subunits. This current, activated at physiological ACTH concentrations (1 to 100 pM) where cAMP production is very low, could play a significant role in aldosterone production.


Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Canais de Cloreto/fisiologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Zona Glomerulosa/fisiologia , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Aldosterona/metabolismo , Animais , Células Cultivadas , Canais de Cloreto/efeitos dos fármacos , Colforsina/farmacologia , AMP Cíclico/metabolismo , Feminino , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Cinética , Oligopeptídeos/farmacologia , Técnicas de Patch-Clamp , Ratos , Ratos Long-Evans , Zona Glomerulosa/citologia
20.
Mol Endocrinol ; 13(9): 1615-26, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10478850

RESUMO

In a previous study, we had shown that activation of the AT2 (angiotensin type 2) receptor of angiotensin II (Ang II) induced morphological differentiation of the neuronal cell line NG108-15. In the present study, we investigated the nature of the possible intracellular mediators involved in the AT2 effect. We found that stimulation of AT2 receptors in NG108-15 cells resulted in time-dependent modulation of tyrosine phosphorylation of a number of cytoplasmic proteins. Stimulation of NG108-15 cells with Ang II induced a decrease in GTP-bound p21ras but a sustained increase in the activity of p42mapk and p44mapk as well as neurite outgrowth. Similarly, neurite elongation, increased polymerized tubulin levels, and increased mitogen-activated protein kinase (MAPK) activity were also observed in a stably transfected NG108-15 cell line expressing the dominant-negative mutant of p21ras, RasN17. These results support the observation that inhibition of p21ras did not impair the effect of Ang II on its ability to stimulate MAPK activity. While 10 microM of the MEK inhibitor, PD98059, only moderately affected elongation, 50 microM PD98059 completely blocked the Ang II- and the RasN17-mediated induction of neurite outgrowth. These results demonstrate that some of the events associated with the AT2 receptor-induced neuronal morphological differentiation of NG108-15 cells not only include inhibition of p21ras but an increase in MAPK activity as well, which is essential for neurite outgrowth.


Assuntos
Angiotensina II/farmacologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Neurônios/efeitos dos fármacos , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Receptores de Angiotensina/efeitos dos fármacos , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Diferenciação Celular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Expressão Gênica , Mutação , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Neurônios/citologia , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Fosfotirosina/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/fisiologia , Transdução de Sinais , Transfecção , Células Tumorais Cultivadas
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