Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Am J Manag Care ; 30(1): e4-e10, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38271568

RESUMO

OBJECTIVES: Few studies have evaluated racial and ethnic differences in several immune-mediated inflammatory diseases (IMIDs) or overlap syndrome (the co-occurrence of ≥ 2 IMIDs). We assessed associations between race and ethnicity and prevalence of IMIDs and overlap syndrome using US claims and electronic health records from 2021. STUDY DESIGN: Retrospective cohort study of 10.8 million adults. METHODS: We identified the 10 most prevalent IMIDs among frequently discussed IMIDs. We estimated associations between the 5 most prevalent IMIDs and overlap syndrome in Hispanic and non-Hispanic Asian and Black adults using non-Hispanic White adults as the referent and stratifying by sex and age (20-39, 40-59, and ≥ 60 years). RESULTS: Inflammatory bowel disease (IBD), systemic lupus erythematosus (SLE), multiple sclerosis (MS), and rheumatoid arthritis (RA) were the most prevalent IMIDs in all races and ethnicities. We observed positive associations (P < .0001) between Hispanic and non-Hispanic Black adults and SLE, Asian women of all ages and Asian men younger than 60 years and SLE, Black women younger than 60 years and MS, and Hispanic and non-White women 60 years or older and RA. Hispanic and non-White adults of all age groups had inverse associations (P < .0001) with IBD. Non-Hispanic Black adults of all ages and Hispanic and non-Hispanic Asian women 40 years or older had inverse associations (P < .0001) with psoriasis/psoriatic arthritis. Overlap syndrome was rare among all groups, with some variation in which IMIDs co-occurred. CONCLUSIONS: We found racial and ethnic differences in the prevalence and co-occurrence of IMIDs in this sample of US adults. Because misdiagnoses are relatively frequent for patients with IMIDs, awareness of racial and ethnic variations in IMIDs could aid early diagnosis and improve disease management.


Assuntos
Artrite Reumatoide , Doenças Autoimunes , Doenças Inflamatórias Intestinais , Lúpus Eritematoso Sistêmico , Adulto , Masculino , Humanos , Feminino , Pessoa de Meia-Idade , Grupos Raciais , Estudos Retrospectivos , Prevalência , Doenças Autoimunes/epidemiologia , Lúpus Eritematoso Sistêmico/epidemiologia , Artrite Reumatoide/epidemiologia , Doenças Inflamatórias Intestinais/epidemiologia , Agentes de Imunomodulação
2.
Future Cardiol ; 17(4): 637-646, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33095033

RESUMO

Background: We depict the burden of heart failure (HF) in North America (NA) and Western Europe (WE), using a cyclical flow diagram of patients from diagnosis/hospitalization until treatment, stabilization and decompensation/death. Materials & methods: We obtained data on HF hospitalizations, prevalence, severity and treatment from national databases and primary/secondary research. Results: In 2020, we estimate 3.6 and 5.2 million HF hospitalizations, and 7.6 and 8.7 million diagnosed prevalent chronic HF (CHF) cases in NA and WE, respectively. All hospitalized HF and 86-88% of prevalent cases are drug-treated. The most widely prescribed drugs for CHF in NA and WE are ß-blockers and loop diuretics, respectively. Conclusion: The high burden of HF in NA and WE calls for greater efforts to prevent ischemic heart disease.


Assuntos
Insuficiência Cardíaca , Antagonistas Adrenérgicos beta , Europa (Continente)/epidemiologia , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Hospitalização , Humanos , América do Norte/epidemiologia
3.
Pharmacoepidemiol Drug Saf ; 25(4): 453-61, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26875591

RESUMO

PURPOSE: The objective of this study was to evaluate regression, matching, and stratification on propensity score (PS) or disease risk score (DRS) in a setting of sequential analyses where statistical hypotheses are tested multiple times. METHODS: In a setting of sequential analyses, we simulated incident users and binary outcomes with different confounding strength, outcome incidence, and the adoption rate of treatment. We compared Type I error rate, empirical power, and time to signal using the following confounder adjustments: (i) regression; (ii) treatment matching (1:1 or 1:4) on PS or DRS; and (iii) stratification on PS or DRS. We estimated PS and DRS using lookwise and cumulative methods (all data up to the current look). We applied these confounder adjustments in examining the association between non-steroidal anti-inflammatory drugs and bleeding. RESULTS: Propensity score and DRS methods had similar empirical power and time to signal. However, DRS methods yielded Type I error rates up to 17% for 1:4 matching and 15.3% for stratification methods when treatment and outcome were common and confounding strength with treatment was stronger. When treatment and outcome were not common, stratification on PS and DRS and regression yielded 8-10% Type I error rates and inflated empirical power. However, when outcome and treatment were common, both regression and stratification on PS outperformed other matching methods with Type I error rates close to 5%. CONCLUSIONS: We suggest regression and stratification on PS when the outcomes and/or treatment is common and use of matching on PS with higher ratios when outcome or treatment is rare or moderately rare.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Simulação por Computador , Fatores de Confusão Epidemiológicos , Hemorragia/etiologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Difusão de Inovações , Feminino , Hemorragia/epidemiologia , Humanos , Masculino , Pontuação de Propensão , Análise de Regressão
4.
BMJ Open ; 5(5): e007375, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25967997

RESUMO

OBJECTIVES: Numerous studies continue to report poorer glycaemic control, and a higher incidence of diabetes-related complications among African-Americans and Hispanic-Americans as compared with non-Hispanic Caucasians with type 2 diabetes. We examined racial/ethnic differences in receipt of hypoglycaemic medications and glycaemic control in a highly insured Massachusetts community sample of individuals with type 2 diabetes. SETTING: Community-based sample from Boston, Massachusetts, USA. PARTICIPANTS: 682 patients with physician-diagnosed diabetes from the third wave of the Boston Area Community Health Survey (2010-2012). The study included approximately equal proportions of African-Americans, Hispanics and Caucasians. METHODS: We examined racial/ethnic disparities in diabetes treatment by comparing proportions of individuals on mutually exclusive diabetes treatment regimens across racial/ethnic subgroups. Using multivariable linear and logistic regression, we also examined associations between race/ethnicity and glycaemic control in the overall population, and within treatment regimens, adjusting for age, gender, income, education, health insurance, health literacy, disease duration, diet and physical activity. RESULTS: Among those treated (82%), the most commonly prescribed antidiabetic regimens were biguanides only (31%), insulin only (23%), and biguanides and insulin (16%). No overall racial/ethnic differences in treatment or glycaemic control (per cent difference for African-Americans: 6.18, 95% CI -1.00 to 13.88; for Hispanic-Americans: 1.01, 95% CI -10.42 to 12.75) were observed. Within regimens, we did not observe poorer glycaemic control for African-Americans prescribed biguanides only, insulin only or biguanides combined with insulin/sulfonylureas. However, African-Americans prescribed miscellaneous regimens had higher risk of poorer glycaemic control (per cent difference=23.37, 95% CI 7.25 to 43.33). There were no associations between glycaemic levels and Hispanic ethnicity overall, or within treatment regimens. CONCLUSIONS: Findings suggest a lack of racial/ethnic disparities in diabetes treatment patterns and glycaemic control in this highly insured Massachusetts study population. Future studies are needed to understand impacts of increasing insurance coverage on racial/ethnic disparities in treatment patterns and related outcomes.


Assuntos
Negro ou Afro-Americano , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Disparidades em Assistência à Saúde , Hispânico ou Latino , Hipoglicemiantes/uso terapêutico , População Branca , Adulto , Idoso , Biguanidas/uso terapêutico , Boston , Diabetes Mellitus Tipo 2/etnologia , Feminino , Disparidades nos Níveis de Saúde , Inquéritos Epidemiológicos , Humanos , Renda , Insulina/uso terapêutico , Seguro Saúde , Masculino , Pessoa de Meia-Idade , Características de Residência , Inquéritos e Questionários
5.
PLoS One ; 10(4): e0122808, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25875902

RESUMO

OBJECTIVES: The prevalence of obesity is disproportionately higher among African-Americans and Hispanics as compared to whites. We investigated the role of biogeographic ancestry (BGA) on adiposity and changes in adiposity in the Boston Area Community Health Survey. METHODS: We evaluated associations between BGA, assessed via Ancestry Informative Markers, and adiposity (body mass index (BMI), percent body fat (PBF), and waist-to-hip ratio (WHR)) and changes in adiposity over 7 years for BMI and WHR and 2.5 years for PBF, per 10% greater proportion of BGA using multivariable linear regression. We also examined effect-modification by demographic and socio-behavioral variables. RESULTS: We observed positive associations between West-African ancestry and cross-sectional BMI (percent difference=0.62%; 95% CI: 0.04%, 1.20%), and PBF (ß=0.35; 95% CI: 0.11, 0.58). We also observed significant effect-modification of the association between West-African ancestry and BMI by gender (p-interaction: <0.002) with a substantially greater association in women. We observed no main associations between Native-American ancestry and adiposity but observed significant effect-modification of the association with BMI by diet (p-interaction: <0.003) with inverse associations among participants with higher Healthy Eating Scores. No associations were observed between BGA and changes in adiposity over time. CONCLUSION: Findings support that West-African ancestry may contribute to high prevalence of total body adiposity among African-Americans, particularly African-American women.


Assuntos
Adiposidade/etnologia , Adiposidade/genética , Negro ou Afro-Americano , Adulto , Idoso , Alelos , Índice de Massa Corporal , Boston , Estudos Transversais , Feminino , Marcadores Genéticos/genética , Geografia , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/etnologia , Obesidade/genética , Fatores Sexuais , Relação Cintura-Quadril
6.
J Infect Dis ; 205(7): 1043-7, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22357659

RESUMO

BACKGROUND: We studied the association between iron intake and polymorphisms in the iron transporter gene SLC40A1 and the risk of tuberculosis. METHODS: We compared iron intake, the frequency of SLC40A1 mutations, and interactions among these variables among 98 tuberculosis patients and 125 controls in Kwazulu-Natal, South Africa. RESULTS: Four SLC40A1 single-nucleotide polymorphisms (SNPs) were associated with an increased risk of tuberculosis and 1 SNP with reduced risk. We also found a gene-environment interaction for 4 nonexonic SNPs and iron intake. CONCLUSIONS: This pilot study demonstrated an association between polymorphisms in SLC40A1 and tuberculosis and provided evidence of an interaction between dietary iron and SLC40A1.


Assuntos
Proteínas de Transporte de Cátions/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Tuberculose/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , África do Sul
7.
BMC Med ; 9: 81, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21722362

RESUMO

BACKGROUND: Multiple studies of tuberculosis treatment have indicated that patients with diabetes mellitus may experience poor outcomes.We performed a systematic review and meta-analysis to quantitatively summarize evidence for the impact of diabetes on tuberculosis outcomes. METHODS: We searched PubMed, EMBASE and the World Health Organization Regional Indexes from 1 January 1980 to 31 December 2010 and references of relevant articles for reports of observational studies that included people with diabetes treated for tuberculosis. We reviewed the full text of 742 papers and included 33 studies of which 9 reported culture conversion at two to three months, 12 reported the combined outcome of failure and death, 23 reported death, 4 reported death adjusted for age and other potential confounding factors, 5 reported relapse, and 4 reported drug resistant recurrent tuberculosis. RESULTS: Diabetes is associated with an increased risk of failure and death during tuberculosis treatment. Patients with diabetes have a risk ratio (RR) for the combined outcome of failure and death of 1.69 (95% CI, 1.36 to 2.12). The RR of death during tuberculosis treatment among the 23 unadjusted studies is 1.89 (95% CI, 1.52 to 2.36), and this increased to an effect estimate of 4.95 (95% CI, 2.69 to 9.10) among the 4 studies that adjusted for age and other potential confounding factors. Diabetes is also associated with an increased risk of relapse (RR, 3.89; 95% CI, 2.43 to 6.23). We did not find evidence for an increased risk of tuberculosis recurrence with drug resistant strains among people with diabetes. The studies assessing sputum culture conversion after two to three months of tuberculosis therapy were heterogeneous with relative risks that ranged from 0.79 to 3.25. CONCLUSIONS: Diabetes increases the risk of failure and death combined, death, and relapse among patients with tuberculosis. This study highlights a need for increased attention to treatment of tuberculosis in people with diabetes, which may include testing for suspected diabetes, improved glucose control, and increased clinical and therapeutic monitoring.


Assuntos
Antituberculosos/administração & dosagem , Complicações do Diabetes , Tuberculose/complicações , Tuberculose/tratamento farmacológico , Humanos , Análise de Sobrevida , Falha de Tratamento , Resultado do Tratamento , Tuberculose/mortalidade
8.
Trop Med Int Health ; 15(11): 1300-14, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20958887

RESUMO

OBJECTIVE: To assess the yield of finding additional TB or diabetes mellitus (DM) cases through systematic screening and to determine the effectiveness of preventive TB therapy in people with DM. METHODS: We systematically reviewed studies that had screened for active TB or implemented preventive therapy for TB among people with DM, and those that screened for DM among patients with TB. We searched published literature through PubMed and EMBASE and included studies that reported the number of TB cases identified among people with DM; the number of DM cases identified among patients with TB, or the relative incidence of TB between people with DM who received a TB prophylaxis and those who did not. We assessed the yield of screening by estimating the prevalence of TB or DM in each study, the prevalence ratio and difference where comparison populations were available, and the number of persons to screen to detect an additional case of TB or DM. RESULTS: Twelve studies on screening for TB in people with DM and 18 studies on screening for DM in patients with TB met our inclusion criteria. Screening for TB in persons with DM demonstrated that TB prevalence in this population is high, ranging from 1.7% to 36%, and increasing with rising TB prevalence in the underlying population as well as with DM severity. Screening patients with TB for DM also yielded high prevalences of DM ranging from 1.9% to 35%. Two studies examining the role of TB preventive therapy in people with DM did not provide sufficient details for clear evidence of the effectiveness. CONCLUSION: Active screening leads to the detection of more TB and DM with varying yield. This review highlights the need for further research in screening and preventive therapy.


Assuntos
Diabetes Mellitus/diagnóstico , Infecções Oportunistas/diagnóstico , Tuberculose/diagnóstico , Adolescente , Adulto , Idoso , Antituberculosos/uso terapêutico , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/epidemiologia , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Infecções Oportunistas/epidemiologia , Infecções Oportunistas/prevenção & controle , Tuberculose/epidemiologia , Tuberculose/prevenção & controle , Adulto Jovem
9.
Infect Immun ; 77(10): 4654-67, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19651861

RESUMO

The pe and ppe genes are unique to mycobacteria and are widely speculated to play a role in tuberculosis pathogenesis. However, little is known about how expression of these genes is controlled. Elucidating the regulatory control of genes found exclusively in mycobacteria, such as the pe and ppe gene families, may be key to understanding the success of this pathogen. In this study, we used a transposon mutagenesis approach to elucidate pe and ppe regulation. This resulted in the identification of Rv0485, a previously uncharacterized transcriptional regulator. Microarray and quantitative real-time PCR analysis confirmed that disruption of Rv0485 reduced the expression of the pe13 and ppe18 gene pair (Rv1195 and Rv1196), defined the Rv0485 regulon, and emphasized the lack of global regulation of pe and ppe genes. The in vivo phenotype of the Rv0485 transposon mutant strain (Rv0485::Tn) was investigated in the mouse model, where it was demonstrated that the mutation has minimal effect on bacterial organ burden. Despite this, disruption of Rv0485 allowed mice to survive for significantly longer, with substantially reduced lung pathology in comparison with mice infected with wild-type Mycobacterium tuberculosis. Infection of immune-deficient SCID mice with the Rv0485::Tn strain also resulted in extended survival times, suggesting that Rv0485 plays a role in modulation of innate immune responses. This is further supported by the finding that disruption of Rv0485 resulted in reduced secretion of proinflammatory cytokines by infected murine macrophages. In summary, we have demonstrated that disruption of a previously uncharacterized transcriptional regulator, Rv0485, results in reduced expression of pe13 and ppe18 and attenuation of M. tuberculosis virulence.


Assuntos
Antígenos de Bactérias/biossíntese , Proteínas de Bactérias/fisiologia , Regulação Bacteriana da Expressão Gênica , Mycobacterium tuberculosis/fisiologia , Mycobacterium tuberculosis/patogenicidade , Transativadores/fisiologia , Fatores de Transcrição/fisiologia , Fatores de Virulência/fisiologia , Sequência de Aminoácidos , Estruturas Animais/microbiologia , Animais , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Contagem de Colônia Microbiana , Elementos de DNA Transponíveis , Feminino , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Dados de Sequência Molecular , Mutagênese Insercional , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sobrevida , Transativadores/genética , Fatores de Transcrição/genética , Tuberculose/microbiologia , Tuberculose/patologia , Fatores de Virulência/genética
10.
Proc Natl Acad Sci U S A ; 105(12): 4656-60, 2008 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-18344320

RESUMO

By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried "nanomicroparticle" vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette-Guérin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG.


Assuntos
Aerossóis/administração & dosagem , Aerossóis/farmacologia , Vacinas Bacterianas/imunologia , Imunização/métodos , Animais , Vacina BCG/imunologia , Vias de Administração de Medicamentos , Cobaias , Umidade , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/microbiologia , Leucina/administração & dosagem , Leucina/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Pulmão/patologia , Masculino , Viabilidade Microbiana/efeitos dos fármacos , Mycobacterium smegmatis/imunologia , Mycobacterium smegmatis/ultraestrutura , Baço/efeitos dos fármacos , Baço/microbiologia , Baço/patologia , Tuberculina
11.
Proc Natl Acad Sci U S A ; 104(8): 2591-5, 2007 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-17299039

RESUMO

With the increasing incidence of tuberculosis and drug resistant disease in developing countries due to HIV/AIDS, there is a need for vaccines that are more effective than the present bacillus Calmette-Guérin (BCG) vaccine. We demonstrate that BCG vaccine can be dried without traditional freezing and maintained with remarkable refrigerated and room-temperature stability for months through spray drying. Studies with a model Mycobacterium (Mycobacterium smegmatis) revealed that by removing salts and cryoprotectant (e.g., glycerol) from bacterial suspensions, the significant osmotic pressures that are normally produced on bacterial membranes through droplet drying can be reduced sufficiently to minimize loss of viability on drying by up to 2 orders of magnitude. By placing the bacteria in a matrix of leucine, high-yield, free-flowing, "vial-fillable" powders of bacteria (including M. smegmatis and M. bovis BCG) can be produced. These powders show relatively minor losses of activity after maintenance at 4 degrees C and 25 degrees C up to and beyond 4 months. Comparisons with lyophilized material prepared both with the same formulation and with a commercial formulation reveal that the spray-dried BCG has better overall viability on drying.


Assuntos
Dessecação , Armazenamento de Medicamentos/métodos , Vacinas contra a Tuberculose , Aerossóis , Contagem de Colônia Microbiana , Congelamento , Proteínas de Fluorescência Verde/metabolismo , Leucina/farmacologia , Mycobacterium smegmatis/efeitos dos fármacos , Mycobacterium smegmatis/isolamento & purificação , Mycobacterium smegmatis/ultraestrutura
12.
Mutat Res ; 548(1-2): 107-16, 2004 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-15063141

RESUMO

Min mice have a germ-line nonsense mutation at codon 850 of the adenomatous polyposis coli (Apc) gene. These mice spontaneously develop multiple polyps in the small and large intestine at the age of 10-12 weeks. The aim of this study was to assess the role of reactive nitrogen species and poly(ADP-ribose) synthetase in tumorogenesis. Oxidative stress was found to be increased in the mucosa of the small intestine of Apc(min/+) mice with a concomitant increase in intestinal polyposis over control mice. Pharmacological inhibition of inducible nitric oxide synthase (NOS) with guanidinoethyldisulfide (GED) or stimulation of the breakdown of the nitrogen reactive species peroxynitrite using a potent decomposition catalyst, FP 15, reduced both the intestinal tumor load and the oxidative stress associated with intestinal polyposis in Apc(min/+) mice. Surprisingly, pharmacological inhibition of poly(ADP-ribose) synthetase by the phenanthridinone derivative PJ 34 also reduced the intestinal polyposis and oxidative stress in these mice, possibly through the inhibition of induction of nitric oxide synthase. These results suggest that reactive nitrogen species particularly peroxynitrite play a pivotal role in development of intestinal polyposis and that strategies to reduce both the oxidative stress and the formation of these radical species may be potential chemopreventive approaches for colorectal cancers.


Assuntos
Genes APC/fisiologia , Pólipos Intestinais/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo , Poli Adenosina Difosfato Ribose/metabolismo , Transdução de Sinais , Animais , Colo/enzimologia , Inibidores Enzimáticos/farmacologia , Guanidinas/farmacologia , Mucosa Intestinal/enzimologia , Pólipos Intestinais/genética , Pólipos Intestinais/terapia , Masculino , Malondialdeído/metabolismo , Metaloproteases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II , Ácido Peroxinitroso/metabolismo , Fenantrenos/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/metabolismo
13.
J Biol Chem ; 279(7): 5667-75, 2004 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-14634022

RESUMO

The bacterial surface protein flagellin is widely distributed and well conserved among distant bacterial species. We and other investigators have reported recently that purified flagellin from Salmonella dublin or recombinant flagellin of Salmonella muenchen origin binds to the eukaryotic toll receptor TLR5 and activates the nuclear translocation of NF-kappaB and mitogen-activated protein kinase, resulting in the release of a host of pro-inflammatory mediators in vitro and in vivo. The amino acid sequence alignment of flagellins from various Gram-negative bacteria shows that the C and N termini are well conserved. It is possible that sequences within the N and C termini or both may regulate the pro-inflammatory activity of flagellin. Here we set out to map more precisely the regions in both termini that are required for TLR5 activation and pro-inflammatory signaling. Systematic deletion of amino acids from either terminus progressively reduced eukaryotic pro-inflammatory activation. However, deletion of amino acids 95-108 (motif N) in the N terminus and 441-449 (motif C) in the C terminus abolished pro-inflammatory activity completely. Site-directed mutagenesis analysis provided further evidence for the importance of motifs N and C. We also present evidence for the functional role of motifs N and C with the TLR5 receptor using a reporter assay system. Taken together, our results demonstrate that the pro-inflammatory activity of flagellin results from the interaction of motif N with the TLR5 receptor on the cell surface.


Assuntos
Flagelina/química , Glicoproteínas de Membrana/metabolismo , Receptores de Superfície Celular/metabolismo , Salmonella/metabolismo , Transporte Ativo do Núcleo Celular , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Sequência de Bases , Células CHO , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Cricetinae , Análise Mutacional de DNA , DNA Complementar/metabolismo , Relação Dose-Resposta a Droga , Flagelina/metabolismo , Deleção de Genes , Proteínas de Fluorescência Verde , Humanos , Técnicas In Vitro , Inflamação , Interleucina-8/metabolismo , Proteínas Luminescentes/metabolismo , Sistema de Sinalização das MAP Quinases , Modelos Biológicos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , NF-kappa B/química , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Plasmídeos/metabolismo , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Fatores de Tempo , Receptor 5 Toll-Like , Receptores Toll-Like , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...