Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Stroke ; 45(3): 835-41, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24457292

RESUMO

BACKGROUND AND PURPOSE: Experimental studies indicate that estrogen typically, but not universally, has a neuroprotective effect in stroke. Ischemic stroke increases membrane-bound G protein-coupled estrogen receptor (GPER) distribution and expression in the brain of male but not female mice. We hypothesized that GPER activation may have a greater neuroprotective effect in males than in females after stroke. METHODS: Vehicle (dimethyl sulfoxide), a GPER agonist (G-1, 30 µg/kg), or a GPER antagonist (G-15, 300 µg/kg) were administered alone or in combination to young or aged male mice, or young intact or ovariectomized female mice, 1 hour before or 3 hours after cerebral ischemia-reperfusion. Some mice were treated with a combination of G-1 and the pan-caspase inhibitor, quinoline-Val-Asp(Ome)-CH2-O-phenoxy (Q-VD-OPh), 1 hour before stroke. We evaluated functional and histological end points of stroke outcome up to 72 hours after ischemia-reperfusion. In addition, apoptosis was examined using cleaved caspase-3 immunohistochemistry. RESULTS: Surprisingly, G-1 worsened functional outcomes and increased infarct volume in males poststroke, in association with an increased expression of cleaved caspase-3 in peri-infarct neurons. These effects were blocked by G-15 or Q-VD-OPh. Conversely, G-15 improved functional outcomes and reduced infarct volume after stroke in males, whether given before or after stroke. In contrast to findings in males, G-1 reduced neurological deficit, apoptosis, and infarct volume in ovariectomized females, but had no significant effect in intact females. CONCLUSIONS: Future therapies for acute stroke could exploit the modulation of GPER activity in a sex-specific manner.


Assuntos
Isquemia Encefálica/patologia , Receptores de Estrogênio/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Acidente Vascular Cerebral/patologia , Envelhecimento/fisiologia , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Encéfalo/patologia , Isquemia Encefálica/tratamento farmacológico , Inibidores de Caspase/farmacologia , Infarto Cerebral/patologia , Feminino , Imuno-Histoquímica , Masculino , Camundongos , Doenças do Sistema Nervoso/patologia , Doenças do Sistema Nervoso/fisiopatologia , Ovariectomia , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Traumatismo por Reperfusão/patologia , Caracteres Sexuais , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento
2.
Naunyn Schmiedebergs Arch Pharmacol ; 386(12): 1081-93, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23989929

RESUMO

Vascular smooth muscle cells (VSMC) are present in arterial intima before atherosclerotic plaques develop and are likely to be exposed to unmodified serum lipids as they enter the vessel wall. We examined the effects of sera from mice on the morphology and function of mouse VSMC. Incubation of a mouse VSMC line (MOVAS) with sera from normocholesterolemic (C57BL/6J) or hypercholesterolemic (APOE(-/-)) mice caused concentration-dependent increases in lipid accumulation as measured by AdipoRed, with the extent of lipid uptake significantly greater with the latter sera type. Inhibition of c-Jun N-terminal kinases (SP600125), Src kinases (AG1879), and clathrin-dependent endocytosis (monodansylcadaverine) to disrupt scavenger receptor-mediated uptake of lipids had no effect on serum-induced lipid accumulation by VSMC. By contrast, inhibition of macropinocytosis with antagonists of PI-3 kinase (LY294002) and actin (cytochalasin D) markedly reduced lipid accumulation. Serum exposure reduced the expression of the ATP-binding cassette transporter A1, consistent with impaired cholesterol efflux, but had no effect on the expression of markers of VSMC differentiation. Moreover, the expression of several inflammation and foam cell markers was unchanged (CCL2, CCL5, and CD68) by mouse sera. The accumulation of unmodified serum lipids by VSMC involves a macropinocytosis-like uptake pathway and is associated with the downregulation of the ATP-binding cassette transporter. We speculate that VSMC may play an atheroprotective role in arterial intima by acting as a "sink" for unmodified lipids.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/metabolismo , Hipercolesterolemia/metabolismo , Lipídeos/sangue , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Pinocitose , Actinas/metabolismo , Animais , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Biomarcadores/sangue , Linhagem Celular , Modelos Animais de Doenças , Regulação para Baixo , Hipercolesterolemia/sangue , Hipercolesterolemia/genética , Mediadores da Inflamação/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Pinocitose/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Fatores de Tempo
3.
Neurosignals ; 21(3-4): 229-39, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22869326

RESUMO

The novel estrogen receptor, G protein-coupled estrogen receptor (GPER, previously named GPR30), is widely distributed throughout the male and female brain and, thus, could potentially play a role in estrogen-mediated neuroprotective effects in diseases such as stroke. We hypothesized that GPER distribution and expression in the brain of male, intact female, and ovariectomized (OVX) mice is increased after 0.5 h middle cerebral artery occlusion. Using immunohistochemistry, we found that ischemia reperfusion increased GPER distribution in the peri-infarct brain regions of male mice, but surprisingly not in intact females or OVX mice. Similar differences were observed in the male and female human brain after stroke. In contrast, GPER distribution was decreased in the infarct core of all mice examined. Furthermore, GPER immunofluorescence was co-localized with the endothelial cell marker, von Willebrand factor, and the neuronal marker, NeuN. Consistent with the immunohistochemical findings, Western blot analysis showed GPER expression is only elevated in the ischemic hemisphere of male mice. Moreover, GPER mRNA expression in males was elevated at 4 h but had returned to baseline by 24 h. In conclusion, these findings indicate that GPER may be a potential therapeutic target after stroke, especially in males, in whom estrogen therapy is not feasible.


Assuntos
Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Acidente Vascular Cerebral/metabolismo , Adulto , Animais , Isquemia Encefálica/genética , Feminino , Humanos , Lactente , Masculino , Camundongos , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Fatores Sexuais , Acidente Vascular Cerebral/genética
4.
PLoS One ; 7(10): e48326, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23118986

RESUMO

Nox2 oxidase is one isoform in a family of seven NADPH oxidases that generate reactive oxygen species (ROS) and thereby contribute to physiological and pathological processes including host defense, redox signaling and oxidative tissue damage. While alternative mRNA splicing has been shown to influence the activity of several Nox-family proteins, functionally relevant splice variants of Nox2 have not previously been identified. We immunoscreened several mouse tissues and cells for the presence of truncated Nox2 proteins and identified a 30 kDa protein in lung, spleen and macrophages. RT-PCR analysis of mRNA from primary and immortalised (RAW264.7) mouse macrophages, and from human alveolar macrophages, identified a truncated Nox2 transcript which, upon sequence analysis, was found to be a product of the 'exon skipping' mode of alternative splicing, lacking exons 4-10 of the Nox2 gene. The predicted protein is comparable in size to that identified by immunoscreening and contains two transmembrane helices and an extended cytosolic C-terminus with binding sites for NADPH and the Nox organiser protein p47phox. Importantly, selective siRNA-mediated knockdown of the transcript reduced expression of the 30 kDa protein in macrophages, and suppressed phorbol ester-stimulated ROS production by 50%. We thus provide the first evidence that Nox2 undergoes alternative mRNA splicing to yield a 30 kDa protein - herein termed Nox2ß - that regulates NADPH oxidase activity in macrophages from mice and humans. The discovery of Nox2ß paves the way for future examination of its role in physiological and pathological processes.


Assuntos
Macrófagos/enzimologia , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , NADPH Oxidases/química , NADPH Oxidases/metabolismo , Sequência de Aminoácidos , Animais , Aterosclerose/enzimologia , Aterosclerose/genética , Sequência de Bases , Vasos Sanguíneos/metabolismo , Regulação Enzimológica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Macrófagos/metabolismo , Masculino , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , NADPH Oxidase 2 , NADPH Oxidases/deficiência , NADPH Oxidases/genética , Isoformas de Proteínas/química , Isoformas de Proteínas/deficiência , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , RNA Interferente Pequeno/genética , Deleção de Sequência
5.
Hypertension ; 60(5): 1207-12, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23033370

RESUMO

Infiltration of macrophages into the artery wall plays detrimental roles during hypertension by promoting vascular inflammation and endothelial dysfunction, and it occurs via a chemo-attractant action of chemokines on macrophage cytokine receptors. We sought to identify the key chemokine receptors associated with macrophage infiltration into the vascular wall during deoxycorticosterone acetate (DOCA)/salt-induced hypertension in mice and to evaluate the impact of pharmacological inhibition of these receptors on blood pressure and leukocyte accumulation. Mice treated with DOCA/salt for 21 days displayed markedly elevated systolic blood pressure (158 ± 2 versus 114 ± 5 mm Hg in sham group; P<0.0001). Polymerase chain reaction screening via a gene array of 20 chemokine receptors indicated an increased expression of CCR2 in aortas of DOCA/salt-treated mice. Real-time polymerase chain reaction confirmed mRNA upregulation of CCR2 in aortas from DOCA/salt-treated animals and of the CCR2 ligands CCL2, CCL7, CCL8, and CCL12 (all >2-fold versus sham; P<0.05). Flow cytometry revealed 2.9-fold higher macrophage numbers (ie, CD45(+) CD11b(+) F4/80(+) cells) in the aortic wall of DOCA/salt versus sham-treated mice. Intervention with a CCR2 antagonist, INCB3344 (30 mg/kg per day, IP), 10 days after the induction of hypertension with DOCA/salt treatment, reduced the aortic expression of CCR2 mRNA and completely reversed the DOCA/salt-induced influx of macrophages. Importantly, INCB3344 substantially reduced the elevated blood pressure in DOCA/salt-treated mice. Hence, our findings highlight CCR2 as a promising therapeutic target to reduce both macrophage accumulation in the vascular wall and blood pressure in hypertension.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Hipertensão/prevenção & controle , Macrófagos/efeitos dos fármacos , Pirrolidinas/farmacologia , Receptores CCR2/antagonistas & inibidores , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/patologia , Pressão Sanguínea/genética , Quimiocina CCL2/genética , Quimiocina CCL7/genética , Quimiocina CCL8/genética , Desoxicorticosterona , Citometria de Fluxo , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Hipertensão/induzido quimicamente , Hipertensão/genética , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quimioatraentes de Monócitos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores CCR2/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Cloreto de Sódio , Regulação para Cima/efeitos dos fármacos
6.
Mol Pharmacol ; 78(1): 94-104, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20413650

RESUMO

Recent years have witnessed the discovery of novel selective agonists of the M(1) muscarinic acetylcholine (ACh) receptor (mAChR). One mechanism invoked to account for the selectivity of such agents is that they interact with allosteric sites. We investigated the molecular pharmacology of two such agonists, 1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone (77-LH-28-1) and 4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl] piperidine hydrogen chloride (AC-42), at the wild-type M(1) mAChR and three mutant M(1) mAChRs. Both agonists inhibited the binding of the orthosteric antagonist [(3)H]N-methyl scopolamine ([(3)H]NMS) in a manner consistent with orthosteric competition or high negative cooperativity. Functional interaction studies between 77-LH-28-1 and ACh also indicated a competitive mechanism. Dissociation kinetics assays revealed that the agonists could bind allosterically when the orthosteric site was prelabeled with [(3)H]NMS and that 77-LH-28-1 competed with the prototypical allosteric modulator heptane-1,7-bis-[dimethyl-3'-phthalimidopropyl]-ammonium bromide under these conditions. Mutation of the key orthosteric site residues Y(381)A (transmembrane helix 6) and W(101)A (transmembrane helix 3) reduced the affinity of prototypical orthosteric agonists but increased the affinity of the novel agonists. Divergent effects were also noted on agonist signaling efficacies at these mutants. We identified a novel mutation, F(77)I (transmembrane helix 2), which selectively reduced the efficacy of the novel agonists in mediating intracellular Ca(2+) elevation and phosphorylation of extracellular signal regulated kinase 1/2. Molecular modeling suggested a possible "bitopic" binding mode, whereby the agonists extend down into the orthosteric site as well as up toward extracellular receptor regions associated with an allosteric site. It is possible that this bitopic mode may explain the pharmacology of other selective mAChR agonists.


Assuntos
Agonistas Muscarínicos/farmacologia , Piperidinas/farmacologia , Quinolonas/farmacologia , Receptor Muscarínico M1/agonistas , Regulação Alostérica , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Mutagênese Sítio-Dirigida , Fosforilação , Ensaio Radioligante , Receptor Muscarínico M1/genética , Receptor Muscarínico M1/metabolismo
7.
J Cereb Blood Flow Metab ; 30(7): 1306-17, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20145655

RESUMO

Cerebral infarct volume is typically smaller in premenopausal females than in age-matched males after ischemic stroke, but the underlying mechanisms are poorly understood. In this study we provide evidence in mice that this gender difference only occurs when the ischemic brain is reperfused. The limited tissue salvage achieved by reperfusion in male mice is associated with increased expression of proinflammatory proteins, including cyclooxygenase-2 (Cox-2), Nox2, and vascular cell adhesion molecule-1 (VCAM-1), and infiltration of Nox2-containing T lymphocytes into the infarcted brain, whereas such changes are minimal in female mice after ischemia-reperfusion (I-R). Infarct volume after I-R was no greater at 72 h than at 24 h in either gender. Infarct development was Nox2 dependent in male but not in female mice, and Nox2 within the infarct was predominantly localized in T lymphocytes. Stroke resulted in an approximately 15-fold increase in Nox2-dependent superoxide production by circulating, but not spleen-derived, T lymphocytes in male mice, and this was approximately sevenfold greater than in female mice. These circulating immune cells may thus represent a major and previously unrecognized source of superoxide in the acutely ischemic and reperfused brain of males (and potentially in postmenopausal females). Our findings provide novel insights into mechanisms that could be therapeutically targeted in acute ischemic stroke patients who receive thrombolysis therapy to induce cerebral reperfusion.


Assuntos
Infarto Cerebral/patologia , Glicoproteínas de Membrana/metabolismo , NADPH Oxidases/metabolismo , Acidente Vascular Cerebral/patologia , Superóxidos/metabolismo , Linfócitos T/metabolismo , Animais , Infarto Cerebral/metabolismo , Circulação Cerebrovascular/fisiologia , Ciclo-Oxigenase 2/metabolismo , Feminino , Humanos , Infarto da Artéria Cerebral Média , Masculino , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , NADPH Oxidase 2 , NADPH Oxidases/genética , Distribuição Aleatória , Fluxo Sanguíneo Regional , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Fatores Sexuais , Acidente Vascular Cerebral/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
8.
J Biol Chem ; 281(49): 37353-60, 2006 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-17015441

RESUMO

We have investigated the glycosylation, disulfide bonding, and subunit structure of mouse TRPM8. To do this, amino-terminal c-myc or hemagglutinin epitope-tagged proteins were incorporated and expressed in Chinese hamster ovary cells. These modifications had no obvious effects on channel function in intracellular calcium imaging assays upon application of agonists, icilin or menthol, and cold temperatures. Unmodified TRPM8 migrates with an apparent mass of 129 kDa and can be glycosylated in Chinese hamster ovary cells to give glycoproteins with apparent masses of 136 and 147 kDa. We identified two potential N-linked glycosylation sites in TRPM8 (Asn-821 and Asn-934) and mutated them to show that only the site in the putative pore region at position 934 is modified and that glycosylation of this site is not absolutely necessary for cell surface expression or responsiveness to icilin, menthol, and cool temperatures. Enzymatic cleavage of the carbohydrate chains indicated that they are complex carbohydrate. The glycosylation site is flanked in the pore by two cysteine residues that we mutated, to prove that they are involved in a conserved double cysteine motif, which is essential for channel function. Mutation of either of these cysteines abolishes function and forces the formation of a non-functional complex of the size of a homodimer. The double cysteine mutant is also non-functional. Finally, we showed in Perfluoro-octanoic acid-polyacrylamide gels that TRPM8 can form a tetramer (in addition to dimer and trimer forms), consistent with current thinking that functional TRP ion channels are tetrameric.


Assuntos
Canais de Cátion TRPM/química , Canais de Cátion TRPM/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação/genética , Células CHO , Linhagem Celular , Temperatura Baixa , Cricetinae , Cisteína/química , Primers do DNA/genética , Dimerização , Glicosilação , Técnicas In Vitro , Mentol/metabolismo , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Peso Molecular , Mutagênese Sítio-Dirigida , Estrutura Quaternária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Canais de Cátion TRPM/genética
9.
Biochem Pharmacol ; 68(11): 2207-19, 2004 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-15498511

RESUMO

This study investigated the effects of the endocannabinoid, anandamide, on M(1) muscarinic acetylcholine receptors (mAChRs) expressed in Chinese hamster ovary (CHO) cells. In the presence of anandamide, [(3)H]N-methylscopolamine ([(3)H]NMS) inhibition binding was characterized by Hill coefficients greater than 1 while saturation binding isotherms were characterized by a reduction in radioligand B(max). Anandamide did not affect the potency of classic agonists, antagonists or allosteric modulators to inhibit [(3)H]NMS binding, indicating that the site of anandamide action did not involve receptor regions recognized by these compounds. Although the mode of binding of anandamide was reversible, the order of ligand addition was important; the inhibitory effect was greatest when anandamide was equilibrated with the receptor prior to radioligand addition, and weakest in the converse situation. Interestingly, the inhibitory potency of anandamide was reduced on pre-equilibration with non-transfected CHO cell membranes, prior to addition of M(1) mAChR-transfected membranes. In phosphoinositide (PI) hydrolysis assays, anandamide significantly reduced the maximal response to acetylcholine, but at higher concentrations than those needed to fully inhibit radioligand binding. Studies utilizing a range of agonists with varying intrinsic activities showed that the inhibitory effects of anandamide on agonist function were most pronounced with the lowest efficacy agonists. These findings suggest that the mechanism of action of anandamide at the M(1) mAChR involves perturbation of the receptor via the membrane in a manner that is sensitive to the conformation of the receptor (occupied versus vacant).


Assuntos
Ácidos Araquidônicos/farmacologia , Membrana Celular/efeitos dos fármacos , Receptor Muscarínico M1/metabolismo , Animais , Sítios de Ligação , Células CHO , Membrana Celular/metabolismo , Cricetinae , Endocanabinoides , Feminino , Cinética , Fosfatidilinositóis/metabolismo , Alcamidas Poli-Insaturadas , Ensaio Radioligante , Receptor Muscarínico M1/efeitos dos fármacos
10.
Am J Ophthalmol ; 138(4): 665-6, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15488805

RESUMO

PURPOSE: To investigate the reported association of the two single-nucleotide polymorphisms (SNPs) of the paraoxonase gene (PON1), Met-Leu 55 (M55L) and Gln-Arg 192 (Q192R), in individuals of Anglo-Celtic descent who have age-related macular degeneration (AMD). DESIGN: Case-control association study. METHODS: Sixty-two individuals with late (end-stage) AMD and 115 control subjects (without AMD) were included in this study. The M55L and Q192R SNPs were amplified by polymerase chain reaction and genotyped, and statistical analysis was undertaken. RESULTS: No association of either SNP was detected in persons of Anglo-Celtic descent who had AMD, although there was a significant difference in SNP allele frequency between Anglo-Celtic and Japanese individuals. CONCLUSION: The M55L and Q192R SNPs of the PON1 gene do not appear to be associated with late AMD in individuals of Anglo-Celtic descent.


Assuntos
Arildialquilfosfatase/genética , Degeneração Macular/enzimologia , Degeneração Macular/genética , Polimorfismo de Nucleotídeo Único/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Feminino , Frequência do Gene , Humanos , Degeneração Macular/etnologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Vitória/epidemiologia
11.
Eur J Pharmacol ; 498(1-3): 59-69, 2004 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-15363976

RESUMO

The effect of ligand pretreatment on human 5-hydroxytryptamine2C (5-HT2C) receptors was examined in CHO cells expressing high (CHO-1C7; 67+/-3 pmol/mg) or low (CHO-1C19; 72+/-10 fmol/mg) levels of the receptor. Seventy-two hours pretreatment of CHO-1C7 cells with various ligands did not affect receptor expression. Pretreatment with inverse agonists enhanced 5-HT-mediated inositol phosphate accumulation with no change in constitutive receptor activity. The enhanced agonist responsiveness was inversely correlated with the intrinsic activity of the pretreatment ligand. Seventy-two hours of pretreatment with the weak agonist, 5-methoxygramine, caused an elevation in constitutive activity but no alteration in 5-HT-mediated signaling. In CHO-1C19 cells, 24 but not 72 h of pretreatment with the inverse agonist mianserin enhanced 5-HT-mediated signaling, with no effect on basal signaling; pretreatment with 5-methoxygramine had no significant effect. These findings highlight differences in the pattern of chronic regulation of 5HT2C receptor signaling between high and low receptor expression levels in a common cellular background.


Assuntos
Ergolinas/metabolismo , Indofenol/análogos & derivados , Receptor 5-HT2C de Serotonina/metabolismo , Algoritmos , Análise de Variância , Animais , Ligação Competitiva/efeitos dos fármacos , Células CHO , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Clorpromazina/farmacologia , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Humanos , Indóis/farmacologia , Indofenol/farmacologia , Fosfatos de Inositol/metabolismo , Cinética , Ligantes , Lisurida/farmacologia , Mianserina/farmacologia , Ensaio Radioligante , Receptor 5-HT2C de Serotonina/genética , Ritanserina/farmacologia , Serotonina/farmacologia , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Trítio , Triptaminas/farmacologia
12.
Invest Ophthalmol Vis Sci ; 45(5): 1311-5, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15111582

RESUMO

PURPOSE: To date, of all the genes studied in relation to age-related macular degeneration (AMD), the alleles of the apolipoprotein (apoE) gene have been the most consistently associated with disease. However, not all apoE studies have found an association, and among these the associations differ. The current study was conducted to investigate further the association of this gene in AMD. METHODS: Three hundred twenty-two unrelated individuals with diagnosed AMD and 123 unrelated but ethnically matched control subjects were analyzed. All subjects completed a standard questionnaire and were given a fundus examination. A blood sample was collected for DNA extraction. The common allelic variants of apoE were screened through the use of polymerase chain reaction (PCR) and restriction enzyme digestion followed by statistical analysis. RESULTS: Individuals with the epsilon3 epsilon4 genotype of apoE had an approximate halving of disease risk for late (end-stage) AMD (odds ratio [OR] 0.58, 95% confidence interval [CI] 0.34-0.98) relative to the epsilon3 epsilon3 genotype at age of ascertainment. Stratification of late AMD into atrophic and neovascular disease revealed that the greatest protective effect for the epsilon3 epsilon4 genotype was in individuals with atrophic disease (OR 0.35, 95% CI 0.13-0.92). Men with the epsilon3 epsilon4 genotype also showed almost a threefold reduction in risk of disease in late AMD (OR 0.36, 95% CI 0.16-0.82). However, individuals with late AMD and the epsilon2 epsilon3 genotype had a significantly earlier mean age of diagnosis of disease (3.4 years, P = 0.015) compared with those with the epsilon3 epsilon3 genotype, and this was most evident in women (3.9 years, P = 0.011) and in individuals with neovascular disease (4.7 years, P = 0.003). CONCLUSIONS: The alleles of apoE appear to have a role in the etiology of AMD, with the epsilon4 allele being protective, or at the very least, delaying the age of diagnosis of disease, whereas the epsilon2 allele appears to have a modifier effect by bringing forward the mean age of disease diagnosis.


Assuntos
Apolipoproteínas E/genética , Degeneração Macular/genética , Idoso , Alelos , Apolipoproteína E2 , Apolipoproteína E4 , DNA/análise , Feminino , Genótipo , Humanos , Masculino , Reação em Cadeia da Polimerase , Fatores de Risco
13.
Pulm Pharmacol Ther ; 16(3): 171-80, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12749833

RESUMO

The present study compared the effects of glucocorticoids on thrombin- and EGF-stimulated proliferation in human cultured airway smooth muscle (ASM) to identify pathways that may be differentially regulated by glucocorticoids. Mitogenic responses to thrombin were inhibited by extracellular-regulated kinase (ERK 1/2) and phosphoinositide 3-kinase (PI3K) inhibitors, whereas mitogenic responses to EGF were inhibited by ERK 1/2 and PI3K inhibitors as well as by the p38 mitogen activated protein kinase inhibitor, SB203580 (10 microM). Mitogenic responses to thrombin were more sensitive to inhibition by dexamethasone (Dex) or fluticasone propionate (FP) than were those to EGF. Elevated cyclin D1 protein and mRNA levels induced by thrombin and EGF were attenuated equally by glucocorticoids. The protein or mRNA levels of the cyclin-dependent kinase inhibitors (cdki) p21(Cip1), p27(Kip1) were unaffected by Dex treatment of ASM cells treated with mitogens. The resistance of EGF-induced proliferation to inhibition by glucocorticoids is not associated with a failure to regulate cyclin D1 induction, nor does it appear to be explained by differential regulation of the levels of the cdki's, p21(Cip1) and p27(Kip1).


Assuntos
Brônquios/efeitos dos fármacos , Ciclina D1/metabolismo , Fator de Crescimento Epidérmico/antagonistas & inibidores , Glucocorticoides/farmacologia , Músculo Liso/efeitos dos fármacos , Trombina/antagonistas & inibidores , Brônquios/metabolismo , Células Cultivadas , DNA/biossíntese , Dexametasona/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Humanos , Músculo Liso/metabolismo , Trombina/farmacologia , Timidina/metabolismo
14.
Hum Mol Genet ; 11(23): 2829-36, 2002 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-12393794

RESUMO

TMPRSS3 encodes a transmembrane serine protease that contains both LDLRA and SRCR domains and is mutated in non-syndromic autosomal recessive deafness (DFNB8/10). To study its function, we cloned the mouse ortholog which maps to Mmu17, which is structurally similar to the human gene and encodes a polypeptide with 88% identity to the human protein. RT-PCR and RNA in situ hybridization on rat and mouse cochlea revealed that Tmprss3 is expressed in the spiral ganglion, the cells supporting the organ of Corti and the stria vascularis. RT-PCR on mouse tissues showed expression in the thymus, stomach, testis and E19 embryos. Transient expression of wild-type or tagged TMPRSS3 protein showed a primary localization in the endoplasmic reticulum. The epithelial amiloride-sensitive sodium channel (ENaC), which is expressed in many sodium-reabsorbing tissues including the inner ear and is regulated by membrane-bound channel activating serine proteases (CAPs), is a potential substrate of TMPRSS3. In the Xenopus oocyte expression system, proteolytic processing of TMPRSS3 was associated with increased ENaC mediated currents. In contrast, 6 TMPRSS3 mutants (D103G, R109W, C194F, W251C, P404L, C407R) causing deafness and a mutant in the catalytic triad of TMPRSS3 (S401A), failed to undergo proteolytic cleavage and activate ENaC. These data indicate that important signaling pathways in the inner ear are controlled by proteolytic cleavage and suggest: (i) the existence of an auto-catalytic processing by which TMPRSS3 would become active, and (ii) that ENaC could be a substrate of TMPRSS3 in the inner ear.


Assuntos
Surdez/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutação de Sentido Incorreto/genética , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Canais de Sódio/metabolismo , Animais , Sítios de Ligação , Western Blotting , Análise Mutacional de DNA , Primers do DNA/química , Surdez/metabolismo , Retículo Endoplasmático/metabolismo , Canais Epiteliais de Sódio , Feminino , Genes Recessivos/genética , Genótipo , Humanos , Hibridização In Situ , Técnicas In Vitro , Masculino , Camundongos , Oócitos/metabolismo , Órgão Espiral/metabolismo , Transporte Proteico , RNA Mensageiro/metabolismo , Coelhos , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Gânglio Espiral da Cóclea/metabolismo , Estria Vascular/metabolismo , Xenopus laevis
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA