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1.
J Prev Alzheimers Dis ; 11(3): 549-557, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38706271

RESUMO

BACKGROUND: In an exploratory 91-participant phase 2a clinical trial (AscenD-LB, NCT04001517) in dementia with Lewy bodies (DLB), neflamapimod showed improvement over placebo on multiple clinical endpoints. To confirm those results, a phase 2b clinical study (RewinD-LB, NCT05869669 ) that is similar to AscenD-LB has been initiated. OBJECTIVES: To optimize the choice of patient population, primary endpoint, and biomarker evaluations in RewinD-LB. DESIGN: Evaluation of the efficacy results from AscenD-LB, the main results of which, and a re-analysis after stratification for absence or presence of AD co-pathology (assessed by plasma ptau181), have been published. In addition, the MRI data from a prior phase 2a clinical trial in Early Alzheimer's disease (AD), were reviewed. SETTING: 22 clinical sites in the US and 2 in the Netherlands. PARTICIPANTS: Probable DLB by consensus criteria and abnormal dopamine uptake by DaTscan™ (Ioflupane I123 SPECT). INTERVENTION: Neflamapimod 40mg capsules or matching placebo capsules, twice-a-day (BID) or three-times-a-day (TID), for 16 weeks. MEASUREMENTS: 6-test Neuropsychological Test Battery (NTB) assessing attention and executive function, Clinical Dementia Rating Sum-of-Boxes (CDR-SB), Timed Up and Go (TUG), International Shopping List Test (ISLT). RESULTS: Within AscenD-LB, patients without evidence of AD co-pathology exhibited a neflamapimod treatment effect that was greater than that in the overall population and substantial (cohen's d effect size vs. placebo ≥ for CDR-SB, TUG, Attention and ISLT-recognition). In addition, the CDR-SB and TUG performed better than the cognitive tests to demonstrate neflamapimod treatment effect in comparison to placebo. Further, clinical trial simulations indicate with 160-patients (randomized 1:1), RewinD-LB conducted in patients without AD co-pathology has >95% (approaching 100%) statistical power to detect significant improvement over placebo on the CDR-SB. Preliminary evidence of positive treatment effects on beta functional connectivity by EEG and basal forebrain atrophy by MRI were obtained in AscenD-LB and the Early AD study, respectively. CONCLUSION: In addition to use of a single dose regimen of neflamapimod (40mg TID), key distinctions between phase 2b and phase 2a include RewinD-LB (1) excluding patients with AD co-pathology, (2) having CDR-SB as the primary endpoint, and (3) having MRI studies to evaluate effects on basal forebrain atrophy.


Assuntos
Benzilaminas , Fluorocarbonos , Indóis , Doença por Corpos de Lewy , Humanos , Doença por Corpos de Lewy/tratamento farmacológico , Doença por Corpos de Lewy/diagnóstico por imagem , Idoso , Feminino , Masculino , Método Duplo-Cego , Imageamento por Ressonância Magnética , Biomarcadores/sangue , Idoso de 80 Anos ou mais , Testes Neuropsicológicos
2.
Zhonghua Xin Xue Guan Bing Za Zhi ; 51(9): 951-957, 2023 Sep 24.
Artigo em Chinês | MEDLINE | ID: mdl-37709711

RESUMO

Objective: To compare the 5-year follow-up outcomes of radiofrequency catheter ablation (RFCA) combined with left atrial appendage closure (LAAC) and long-term oral anticoagulant (OAC) after RFCA in patients with atrial fibrillation. Methods: This retrospective cross-sectional study included patients with atrial fibrillation who underwent"one-stop"procedure in the First Affiliated Hospital of Ningbo University from September 2015 to December 2017 (RFCA+LAAC group). Baseline data of patients were collected. Propensity score matching at the ratio of 1∶1 was used to select patients with atrial fibrillation who took long-term OAC after RFCA (RFCA+OAC group). The maintenance rate of sinus rhythm and the incidence of adverse events during follow-up were compared between the two groups. Results: A total of 110 patients were enrolled in the RFCA+LAAC group and RFCA+OAC group, respectively. Age of patients was (67.4±8.8) years in RFCA+LAAC group, and there were 42 (38.2%) female patients. Age of patients was (67.3±7.9) years in RFCA+OAC group, and there were 47 (42.7%) female patients. The patients were followed up for mean of (5.3±1.1) years. There was no significant difference in the maintenance rate of sinus rhythm (log-rank: χ2=0.277, P=0.602) and incidence of ischemic stroke events (2.7% (3/110) vs. 4.5% (5/110), P=0.719) during follow-up between the two groups. The incidence of bleeding events (6.4% (7/110) vs. 18.2% (20/110), P=0.008) and major bleeding events (1.8% (2/110) vs. 8.2% (9/110), P=0.030) was significantly higher in the RFCA+OAC group than in the RFCA+LAAC group. Conclusion: There is no significant difference between RFCA+LAAC group and RFCA+OAC group in maintenance rate of sinus rhythm and incidence of ischemic stroke events. Patients in the RFCA+LAAC group have a lower risk of bleeding events compared to the RFCA+OAC group.


Assuntos
Fibrilação Atrial , Ablação por Cateter , AVC Isquêmico , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Fibrilação Atrial/cirurgia , Estudos Transversais , Seguimentos , Estudos Retrospectivos , Anticoagulantes/uso terapêutico
3.
Zhonghua Xin Xue Guan Bing Za Zhi ; 50(8): 780-784, 2022 Aug 24.
Artigo em Chinês | MEDLINE | ID: mdl-35982010

RESUMO

Objective: To evaluate the feasibility and safety of the LAmbre occluder for large-diameter left atrial appendage occlusion. Methods: This study was a retrospective cohort study. Patients with large orifice of the left atrial appendage (≥31 mm) and occlusion with the LAmbre device in the Arrhythmia Center of Ningbo First Hospital were included from June 2018 to March 2020. Baseline data were collected and major perioperative complications of left atrial appendage occlusion (including death, stroke, instrumental embolism, cardiac tamponade, and major bleeding events) were recorded. Patients were followed up 45 days, 6 months and 12 months after surgery. The shunt and device-related thrombosis were recorded by esophageal cardiac ultrasound or pulmonary vein CT, and the occurrence of postoperative thromboembolism, bleeding events, death and other serious adverse events were recorded. Results: The average age and left atrial appendage ostial dimension of 32 patients (37.5% women) included in this research were (70.4±8.4) years old and (34.4±2.9) mm. The LAmbre device was successfully implanted in 31(96.9%) patients. No major complications occurred during the perioperative period. During the 12-month follow-up, pericardial tamponade occurred in 1(3.2%) patient and was recovered after treatment. There was no occluder edge shunt>5 mm in patients followed up by esophageal echocardiography. No significant peri-device leak, device-related thrombus, thromboembolism or death event has occurred. Conclusion: The LAmbre occluder may be feasible and safe for large-diameter left atrial appendage occlusion.


Assuntos
Apêndice Atrial , Dispositivo para Oclusão Septal , Idoso , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Dispositivo para Oclusão Septal/efeitos adversos , Acidente Vascular Cerebral/epidemiologia , Tromboembolia/etiologia , Trombose , Resultado do Tratamento
4.
Zhonghua Yi Xue Za Zhi ; 101(13): 950-955, 2021 Apr 06.
Artigo em Chinês | MEDLINE | ID: mdl-33789377

RESUMO

Objective: To investigate the safety and efficacy of percutaneous left atrial appendage closure (LAAC) in nonvalvular atrial fibrillation patients (NVAF) with left atrial spontaneous echocardiographic contrast (LA SEC). Methods: A total of 95 NVAF patients treated in the Department of Cardiology of Ningbo First Hospital from July 2018 to June 2019 were enrolled in this study. The study population was divided into two group according to the presence or absence of LA SEC detected by transesophageal echocardiography (TEE). TEE was scheduled 45 days post-procedure to detect device-related thrombus (DRT). Stroke and bleeding events were recorded during follow-up. Periprocedural complications and follow-up results were compared between the two groups. Results: LA diameters were smaller in non-LA SEC group than LA SEC group ((44.0±7.4)mm vs (47.3±6.6)mm, P=0.033). Watchman device was successfully implanted into all the enrolled patients. No death, transient ischemic attack (TIA)/stroke, device embolization and major bleeding events occurred. Fifty patients (90.2%) in LA SEC group and 31 patients (91.2%) in non-LA SEC group finished TEE follow-up 45 days post-procedure. No device-related thrombus was detected in non-LA SEC group, while 2 cases (6.5%) were detected in LA SEC group, but there was no significant differences in the incidence between the two groups (P=0.127). The LA SEC group and non-LA SEC group were followed-up for (12.3±3.8) months and (12.9±3.3) months, respectively; and there was no significant differences in the incidence of death, TIA/stroke, major and minor bleeding events between two groups during the follow-up (all P>0.05). Conclusion: LAAC in NVAF patients with LA SEC was safe and effective. However, the incidence of DRT was slightly higher.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Procedimentos Cirúrgicos Cardíacos , Acidente Vascular Cerebral , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Ecocardiografia Transesofagiana , Átrios do Coração , Humanos , Resultado do Tratamento
8.
Anaesth Rep ; 7(2): 83-87, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32051958

RESUMO

A 29-year-old previously healthy patient presented with a hyperparathyroid-induced hypercalcaemic crisis refractory to conventional therapy. The patient developed ventricular fibrillation and subsequently required emergency parathyroidectomy and extracorporeal membrane oxygenation support. Extensive intracardiac and pulmonary trunk thrombi were identified soon after the commencement of extracorporeal membrane oxygenation, despite full anticoagulation. In this report we highlight the non-specific presentations of hypercalcaemia which may lead to delayed diagnosis, and discuss the incidence, risk factors and treatment of a hyperparathyroid-induced hypercalcaemic crisis. We emphasise the role of emergency parathyroidectomy as a salvage therapy in medically refractory We consider the likely factors leading to intracardiac thrombi formation in this case, including how hypercalcaemia may have been a contributing factor.

9.
HIV Med ; 5(5): 364-70, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15369512

RESUMO

OBJECTIVES: To determine the safety and effectiveness of a once-daily highly active antiretroviral therapy (HAART) regimen in patients at risk for poor adherence using directly observed therapy (DOT) for 24 weeks followed by weekly phone contact for another 24 weeks. METHODS: A prospective, open-label pilot study was carried out. Antiretroviral-naïve patients with advanced HIV disease were treated with once-daily amprenavir 1200 mg, ritonavir 200 mg, didanosine 400 mg and lamivudine 300 mg. After 24 weeks, DOT was substituted by weekly phone contact. Measurements of viral load and CD4 cell count, and safety laboratory measurements, were taken regularly for 48 weeks. RESULTS: Twenty-two patients were enrolled in the study, of whom 19 completed at least 4 weeks of treatment. Seventeen patients completed 24 weeks and 13 completed 48 weeks. None discontinued treatment as a result of adverse events. The median baseline HIV viral load was 5.29 log(10) HIV-1 RNA copies/mL and the median CD4 cell count was 20 cells/microL. At weeks 24 and 48, 74% of the patients had viral loads <400 copies/mL. At 48 weeks, the median decrease in viral load from baseline was 3.06 log(10) copies/mL, and the median increase in CD4 cell count was 118 cells/microL. The median trough plasma amprenavir concentrations at weeks 1 and 24 were 1.87 and 1.42 microg/mL, respectively. CONCLUSIONS: This study suggests that DOT followed by weekly patient contact results in good treatment outcome in this challenging population. The median trough plasma amprenavir concentrations were above the effective concentration of drug that resulted in 90% inhibition of viral load in vivo (EC(90)) for wild-type HIV.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Terapia Diretamente Observada , Infecções por HIV/tratamento farmacológico , Ritonavir/uso terapêutico , Sulfonamidas/uso terapêutico , Adulto , Fármacos Anti-HIV/sangue , Terapia Antirretroviral de Alta Atividade , Carbamatos , Esquema de Medicação , Feminino , Furanos , Infecções por HIV/sangue , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Ritonavir/sangue , Estatísticas não Paramétricas , Sulfonamidas/sangue , Resultado do Tratamento , Carga Viral
10.
Synapse ; 35(3): 173-81, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10657024

RESUMO

Atypical antipsychotic drugs (APDs) such as clozapine and olanzapine antagonize both D(1) and D(2) receptors; however, little is known regarding their pharmacologic effect on specific neuronal elements within the local circuitry of corticolimbic regions, such as medial prefrontal cortex (mPFC). To characterize the effect of short-term antagonism of the D(1) receptor a high-resolution autoradiographic technique was used to assess the density (B(max)) and affinity (K(d)) of this receptor on pyramidal cells (i.e., large neurons (LNs, >/=100 microm(2))), nonpyramidal cells (i.e., small neurons (SNs, <100 microm(2))) and in the surrounding neuropil (NPL) of layer VI in rat mPFC. Either normal saline or the selective D(1) antagonist SCH23390 (1.0 mg/kg/day) were administered for 48 h via Alzet osmotic pumps. Frozen sections were incubated in [(3)H]SCH23390 (1-8 nM) in the presence or absence of the competitive inhibitor SKF38393 (10 microM). A microscopic adaptation to Scatchard analysis revealed a significant increase (82%) in B(max) for neuronal cell bodies (P < 0.05), but not for neuropil of drug-treated animals. Further analysis indicated that the increase in B(max) was present on SNs (94%, P < 0.05), but not LNs in SCH23390-treated rats. In contrast, K(d) values for LNs, SNs, and NPL were not significantly altered by drug treatment. Since the vast majority of SNs are nonpyramidal in nature, short-term administration of a selective D(1) antagonist seems to be associated with a preferential upregulation of this receptor on interneurons. Overall, these results are consistent with the hypothesis that the mechanism of action of atypical antipsychotic medications involves changes in D(1) receptor activity associated with local circuit neurons in rat mPFC.


Assuntos
Benzazepinas/farmacologia , Antagonistas de Dopamina/farmacologia , Neurônios/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Receptores de Dopamina D1/efeitos dos fármacos , Animais , Masculino , Neurônios/metabolismo , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D1/antagonistas & inibidores , Receptores de Dopamina D1/metabolismo
11.
Psychopharmacology (Berl) ; 141(1): 6-10, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9952058

RESUMO

The dopamine D4 receptor may be a site through which the clinical effects of antipsychotic drugs are mediated. Polymorphisms of a 48 base pair repeat in the third exon of the DRD4 gene code for different length segments in the third intracytoplasmic loop of the D4 receptor. The most common long (seven repeat) form of the D4 receptor has been shown in both physiologic and pharmacologic experiments to respond differently to dopamine agonists and antagonists than do shorter forms of D4. Thus, variants of D4 may partly determine patient response to antipsychotic drugs and, in particular, response to typical neuroleptics, which have a relatively low affinity for the D4 receptor, as compared to clozapine, which has a relatively high affinity for D4. DRD4 polymorphisms in the third intron were characterized in 28 patients with chronic psychosis who responded well to typical neuroleptics, 32 patients who responded well to clozapine, and 57 healthy comparison subjects. Patients responding to typical neuroleptics carried the allele for the long (seven repeat) form of the D4 receptor (allele frequency 8.9%) less frequently than patients responding to clozapine (allele frequency 23.4%, P = 0.046) or healthy comparison subjects (allele frequency 26.3%, P = 0.004). The results of this study suggest that inherited variants of D4 may explain some of the interindividual variation seen in patient response to different classes of antipsychotic medication.


Assuntos
Antipsicóticos/farmacologia , Polimorfismo Genético , Transtornos Psicóticos/genética , Receptores de Dopamina D2/genética , Adulto , Antipsicóticos/efeitos adversos , Antipsicóticos/uso terapêutico , Clozapina/efeitos adversos , Clozapina/farmacologia , Clozapina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/tratamento farmacológico , Receptores de Dopamina D2/efeitos dos fármacos , Receptores de Dopamina D4 , Resultado do Tratamento
12.
Proc Natl Acad Sci U S A ; 95(25): 15049-54, 1998 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-9844013

RESUMO

The brain serotonin (5-hydroxytryptamine; 5-HT) system is a powerful modulator of emotional processes and a target of medications used in the treatment of psychiatric disorders. To evaluate the contribution of serotonin 5-HT1A receptors to the regulation of these processes, we have used gene-targeting technology to generate 5-HT1A receptor-mutant mice. These animals lack functional 5-HT1A receptors as indicated by receptor autoradiography and by resistance to the hypothermic effects of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Homozygous mutants display a consistent pattern of responses indicative of elevated anxiety levels in open-field, elevated-zero maze, and novel-object assays. Moreover, they exhibit antidepressant-like responses in a tail-suspension assay. These results indicate that the targeted disruption of the 5-HT1A receptor gene leads to heritable perturbations in the serotonergic regulation of emotional state. 5-HT1A receptor-null mutant mice have potential as a model for investigating mechanisms through which serotonergic systems modulate affective state and mediate the actions of psychiatric drugs.


Assuntos
Ansiedade/genética , Encéfalo/fisiologia , Depressão/genética , Mutação , Receptores de Serotonina/genética , Animais , Marcação de Genes , Masculino , Camundongos , Camundongos Endogâmicos C57BL
13.
Ann N Y Acad Sci ; 861: 74-8, 1998 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9928241

RESUMO

Serotonin 5-HT2C receptor null mutant mice were generated to assess the contribution of this receptor to the actions of serotonin. Mutant mice displayed both an epilepsy and obesity phenotype. The epilepsy syndrome was characterized by spontaneous seizures, lowered seizure threshold, enhanced seizure propagation and sound-induced seizure susceptibility. These findings implicate 5-HT2C receptors in the regulation of neuronal network excitability. It was also observed that body weight and adipose tissue deposition were elevated in adult mutant mice relative to their wild type littermates. Paired-feeding studies suggest that the obesity syndrome is a result of increased food intake. In addition, mutants displayed reduced sensitivity to the appetite suppressant actions of non-specific serotonergic agonists. These studies establish a role for 5-HT2C receptors in the serotonergic regulation of body weight and food intake.


Assuntos
Epilepsia/genética , Obesidade/genética , Receptores de Serotonina/fisiologia , Convulsões/genética , Animais , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Comportamento Alimentar , Camundongos , Camundongos Mutantes , Camundongos Mutantes Neurológicos , Rede Nervosa/fisiologia , Fenótipo , Receptor 5-HT2C de Serotonina
14.
Mol Cell Biol ; 14(7): 4958-74, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8007991

RESUMO

Human proenkephalin gene transcription is transactivated by human T-cell leukemia virus type I (HTLV-I) Tax in human Jurkat T lymphocytes. This transactivation was further enhanced in Jurkat cells treated with concanavalin A, cyclic AMP, or 12-O-tetradecanoylphorbol-13-acetate. Deletion and cis-element transfer analyses of the human proenkephalin promoter identified a cyclic AMP-responsive AP-1 element (-92 to -86) as both necessary and sufficient to confer Tax-dependent transactivation. Different AP-1 or cyclic AMP-responsive element-binding protein (CREB)/activating transcription factor (ATF) proteins which bind this element were expressed in murine teratocarcinoma F9 cells to identify those capable of mediating Tax-dependent transactivation of human proenkephalin gene transcription. Although CREB, c-Fos, c-Jun, and JunD did not have significant effects, JunB inhibited the Tax-dependent transactivation. In contrast, ATF3 dramatically induced Tax-dependent transactivation, which was further enhanced by protein kinase A. Electrophoretic mobility shift assays with recombinant fusion proteins expressed and purified from bacteria indicate that the DNA-binding activity of ATF3 is also dramatically enhanced by Tax. Chimeric fusion proteins consisting of the DNA-binding domain of the yeast transcription factor Gal4 and the amino-terminal domain (residues 1 to 66) of ATF3 were able to mediate Tax-dependent transactivation of a Gal4-responsive promoter, which suggests a direct involvement of this region of ATF3. Recombinant fusion proteins of glutathione S-transferase with either the amino- or carboxy-terminal (residues 139 to 181) domain of ATF3 were able to specifically interact with Tax. Furthermore, specific antisera directed against Tax coimmunoprecipitated ATF3 only in the presence of Tax.


Assuntos
AMP Cíclico/farmacologia , Encefalinas/biossíntese , Expressão Gênica , Produtos do Gene tax/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/genética , Regiões Promotoras Genéticas , Precursores de Proteínas/biossíntese , Fatores de Transcrição/metabolismo , Transcrição Gênica , Ativação Transcricional , Fator 3 Ativador da Transcrição , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Concanavalina A/farmacologia , Primers do DNA , Elementos Facilitadores Genéticos , Encefalinas/genética , Escherichia coli , Humanos , Dados de Sequência Molecular , Plasmídeos , Reação em Cadeia da Polimerase , Biossíntese de Proteínas , Precursores de Proteínas/genética , Proteínas Recombinantes de Fusão/biossíntese , Deleção de Sequência , Acetato de Tetradecanoilforbol , Fatores de Transcrição/biossíntese , Células Tumorais Cultivadas
15.
Mol Endocrinol ; 8(1): 59-68, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8152431

RESUMO

Activating transcription factor-3 (ATF-3) is one member of a large family of leucine zipper transcription factors which bind to promoters responsive to cAMP and phorbol ester at the related cAMP (CRE) and phorbol ester response elements. We report here that ATF-3 is coexpressed with the neuropeptide precursor proenkephalin in human neuroblastoma SK-N-MC cells. Cotransfection experiments indicate that activation of proenkephalin gene expression by ATF-3 is dependent upon both the catalytic subunit of the cAMP-dependent protein kinase and the CRE-2 element. The CRE-2 element is essential for second messenger-inducible expression and is known to bind AP-1-like transcription factors. ATF-3 expressed in bacteria or from rabbit reticulocyte lysates binds to the proenkephalin CRE-2 element as a homodimer and as a heterodimer with Jun-D, another activator of proenkephalin transcription. ATF-3 stimulates binding of Jun-D to the proenkephalin CRE-2 element and acts synergistically with Jun-D to induce proenkephalin gene expression. Sequential immunoprecipitations of ATF-3 from SK-N-MC cells expressing proenkephalin indicate that ATF-3 is complexed with Jun-D in vivo and that both proteins are highly phosphorylated. Together, our results suggest that ATF-3 may play an important role in the regulation of gene expression by cAMP-dependent intracellular signaling pathways.


Assuntos
AMP Cíclico/farmacologia , Expressão Gênica/efeitos dos fármacos , Fatores de Transcrição/farmacologia , Fator 3 Ativador da Transcrição , Sequência de Bases , Sítios de Ligação , DNA/metabolismo , Sinergismo Farmacológico , Encefalinas/genética , Humanos , Zíper de Leucina , Substâncias Macromoleculares , Dados de Sequência Molecular , Neuroblastoma/metabolismo , Fosforilação , Precursores de Proteínas/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Proto-Oncogênicas c-jun/farmacologia , Proteínas Recombinantes de Fusão , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Células Tumorais Cultivadas , beta-Galactosidase/genética
16.
Mol Gen Genet ; 232(3): 367-76, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1588907

RESUMO

The mutant allele rad9-192 renders Schizosaccharomyces pombe cells sensitive to ionizing radiation and UV light. We have isolated from a S. pombe genomic DNA library a unique recombinant plasmid that is capable of restoring wild-type levels of radioresistance to a rad9-192-containing cell population. Plasmid integration studies using the cloned DNA, coupled with mating and tetrad analyses, indicate that this isolated DNA contains the wild-type rad9 gene. We inactivated the repair function of the cloned fragment by a single insertion of the S. pombe ura4 gene. This nonfunctional fragment was used to create a viable disruption mutant, thus demonstrating that the rad9 gene does not encode an essential cellular function. In addition, the rad9-192 mutant population is as radiosensitive as the disruption mutant, indicating that rad9 gene function is severely if not totally inhibited by the molecular defect responsible for the rad9-192 phenotype. DNA sequence analysis of rad9 reveals an open reading frame of 1,278 bp, interrupted by three introns 53 bp, 57 bp, and 56 bp long, respectively, and ending in the termination codon TAG. This gene is capable of encoding a protein of 426 amino acids, with a corresponding calculated molecular weight of 47,464 daltons. No significant homology was detected between the rad9 gene or its deduced protein sequence and sequences previously entered into DNA and protein sequence data banks.


Assuntos
Reparo do DNA , Genes Fúngicos , Mutagênese , Schizosaccharomyces/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular/métodos , Cruzamentos Genéticos , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Genes Reguladores , Biblioteca Genômica , Dados de Sequência Molecular , Peso Molecular , Plasmídeos , Reação em Cadeia da Polimerase , Radiação Ionizante , Schizosaccharomyces/crescimento & desenvolvimento , Schizosaccharomyces/efeitos da radiação , Raios Ultravioleta
17.
NIDA Res Monogr ; 126: 98-112, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1491720

RESUMO

The recent finding that neurotransmitters and drugs that affect neurotransmission have important influences on gene expression suggests that drug-induced alterations in gene expression may underlie many long-term effects of addictive drugs, for example, dependence and drug-seeking behaviors. These long-term adaptive responses to opiate drugs have been particularly difficult to understand at a mechanistic level. Data presented here indicate that the gene encoding the opioid precursor proenkephalin is highly regulated by neural activity, second-messenger pathways, and PKA. These observations raise the possibility that drugs of abuse (e.g., opiates acting through opiate receptors) may act at the genetic level to modulate the expression of endogenous opiates and that these effects may underlie one component of the brain's long-term adaptive response to exogenous opiates. The transgenic animals described above can be used to investigate opiate drug-induced changes in proenkephalin gene expression, allowing rapid analysis of changes in proenkephalin gene expression in highly restricted populations of neurons in a fashion previously impossible. In addition, by analyzing the effects of specific enhancer mutations on tissue-specific and transsynaptic regulation of proenkephalin expression, transgenic models will permit mechanistic investigations within the intact nervous system that cannot otherwise be undertaken. Investigation of mechanisms underlying this process requires the analysis of intracellular signaling pathways, responsive DNA regulatory elements, and the transcription factors transducing synaptic signals into gene regulation. In the studies described herein, we demonstrate that AP-1 complexes consisting of different Jun proteins differentially regulate proenkephalin transcription at the CRE-2 element. c-Jun constitutively activates proenkephalin transcription, whereas JunD activates in a fashion completely dependent on the activation of second-messenger pathways and the cAMP-dependent PKA. JunB alone has no effect on proenkephalin gene expression, yet this molecule effectively blocks activation mediated by JunD and, hence, may act as a repressor. These data are consistent with a model (figure 4) in which preexisting JunD mediates the rapid cAMP-dependent activation of the proenkephalin enhancer, whereas IEGs such as JunB or c-Fos mediate the protein synthesis-dependent inactivation. Because c-Jun activates proenkephalin transcription constitutively, induction of c-Jun may lead to a further and prolonged activation of proenkephalin gene expression. Hence, the ratio of c-Jun to JunB induction may determine whether proenkephalin is repressed or further activated.


Assuntos
Regulação da Expressão Gênica/fisiologia , Genes jun/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Sequência de Bases , Encefalinas/genética , Humanos , Dados de Sequência Molecular , Precursores de Proteínas/genética
18.
Proc Natl Acad Sci U S A ; 88(22): 10222-6, 1991 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-1719551

RESUMO

We demonstrate that JunD, a component of the AP-1 transcription factor complex, activates transcription of the human proenkephalin gene in a fashion that is completely dependent upon the cAMP-dependent protein kinase, protein kinase A. Activation of proenkephalin transcription by JunD is dependent upon a previously characterized cAMP-, phorbol ester-, and Ca(2+)-inducible enhancer, and JunD is shown to bind the enhancer as a homodimer. Another component of the AP-1 transcription complex, JunB, is shown to inhibit activation mediated by JunD. As a homodimer JunB is unable to bind the enhancer; however in the presence of c-Fos, high-affinity binding is observed. Furthermore, JunD is shown to activate transcription of genes linked to both cAMP and phorbol ester response elements in a protein kinase A-dependent fashion, further blurring the distinction between these response elements. These results demonstrate that the transcriptional activity of an AP-1-related protein is regulated by the cAMP-dependent second-messenger pathway and suggest that JunD and other AP-1-related proteins may play an important role in the regulation of gene expression by cAMP-dependent intracellular signaling pathways.


Assuntos
AMP Cíclico/fisiologia , Encefalinas/genética , Proteínas Quinases/metabolismo , Precursores de Proteínas/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , Animais , Sequência de Bases , Linhagem Celular , Colforsina/farmacologia , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica/efeitos dos fármacos , Genes fos , Glioma , Humanos , Camundongos , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Reticulócitos/metabolismo , Sistemas do Segundo Mensageiro , Ativação Transcricional , Transfecção
19.
Nucleic Acids Res ; 19(10): 2721-8, 1991 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-1828294

RESUMO

A short region of the human proenkephalin promoter has been shown previously to mediate transcriptional regulation in response to activation of the cAMP, TPA, and Ca+ + dependent intracellular signalling pathways. Two adjacent DNA elements, CRE-1 and CRE-2, are essential for this regulation although neither element alone is sufficient for inducible expression. The CRE-2 element consists of overlapping binding sites for the transcription factors AP-1 and AP-4. The CRE-1 element has been shown to interact with a DNA binding factor called ENKTF-1. Here we characterize proteins from bovine brain which bind the CRE-1 element of the human proenkephalin gene. Interactions between proteins binding the CRE-1 and CRE-2 elements are characterized in vitro using affinity purified DNA binding proteins. We demonstrate that CRE-1 binding proteins from bovine brain consist of three different polypeptides each belonging to the NF-I family of transcription factors. Point mutation analysis of the contacts of these proteins with the CRE-1 element indicate that NF-I proteins contact the inducible enhancer at the sequence CTGGCxxxxxxCCT which overlaps the CRE-1 element (underlined) defined by in vivo point mutation analysis. Cotransfection of one of the three NF-I proteins purified from bovine brain, NF-I/Red1, together with a proenkephalin/bacterial chloramphenicol acetyl transferase (CAT) fusion gene repressed protein kinase A or forskolin stimulated CAT expression.


Assuntos
Encéfalo/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Encefalinas/genética , Precursores de Proteínas/genética , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , DNA/metabolismo , Análise Mutacional de DNA , Proteínas de Ligação a DNA/isolamento & purificação , Desoxirribonuclease I/metabolismo , Células HeLa , Humanos , Dados de Sequência Molecular , Fatores de Transcrição NFI , Proteínas Nucleares , Proteínas Repressoras/metabolismo , Transfecção , Proteína 1 de Ligação a Y-Box
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