RESUMO
We investigated the dynamics of seroconversion in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. During March 29-May 22, 2020, we collected serum samples and associated clinical data from 177 persons in London, UK, who had SARS-CoV-2 infection. We measured IgG against SARS-CoV-2 and compared antibody levels with patient outcomes, demographic information, and laboratory characteristics. We found that 2.0%-8.5% of persons did not seroconvert 3-6 weeks after infection. Persons who seroconverted were older, were more likely to have concurrent conditions, and had higher levels of inflammatory markers. Non-White persons had higher antibody concentrations than those who identified as White; these concentrations did not decline during follow-up. Serologic assay results correlated with disease outcome, race, and other risk factors for severe SARS-CoV-2 infection. Serologic assays can be used in surveillance to clarify the duration and protective nature of humoral responses to SARS-CoV-2 infection.
Assuntos
COVID-19/sangue , COVID-19/imunologia , Imunoglobulina G/sangue , SARS-CoV-2 , Soroconversão , Adulto , Idoso , Anticorpos Antivirais/sangue , COVID-19/fisiopatologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
RATIONALE: Emphysema in chronic obstructive pulmonary disease (COPD) can be characterized by high-resolution chest computed tomography (HRCT); however, the repeated use of HRCT is limited because of concerns regarding radiation exposure and cost. OBJECTIVES: To evaluate biomarkers associated with emphysema and COPD-related clinical characteristics, and to assess the relationships of soluble receptor for advanced glycation endproducts (sRAGE), a candidate systemic biomarker identified in this study, with single-nucleotide polymorphisms (SNPs) in the gene coding for RAGE (AGER locus) and with clinical characteristics. METHODS: Circulating levels of 111 biomarkers were analyzed for association with clinical characteristics in 410 patients with COPD enrolled in the TESRA study. sRAGE was also measured in the ECLIPSE cohort in 1,847 patients with COPD, 298 smokers and 204 nonsmokers. The association between 21 SNPs in the AGER locus with sRAGE levels and clinical characteristics was also investigated. MEASUREMENTS AND MAIN RESULTS: sRAGE was identified as a biomarker of diffusing capacity of carbon monoxide and lung density in the TESRA cohort. In the ECLIPSE cohort, lower sRAGE levels were associated with increased emphysema, increased Global Initiative for Chronic Obstructive Lung Disease stage, and COPD disease status. The associations with emphysema in both cohorts remained significant after covariate adjustment (P < 0.0001). One SNP in the AGER locus, rs2070600, was associated with circulating sRAGE levels both in TESRA (P = 0.0014) and ECLIPSE (7.07 × 10(-16)), which exceeded genome-wide significance threshold. Another SNP (rs2071288) was also associated with sRAGE levels (P = 0.01) and diffusing capacity of carbon monoxide (P = 0.01) in the TESRA study. CONCLUSIONS: Lower circulating sRAGE levels are associated with emphysema severity and genetic polymorphisms in the AGER locus are associated with systemic sRAGE levels. Clinical trial registered with www.clinicaltrials.gov (NCT 00413205 and NCT 00292552).
Assuntos
Enfisema/sangue , Doença Pulmonar Obstrutiva Crônica/genética , Receptores Imunológicos/genética , Idoso , Biomarcadores/sangue , Enfisema/diagnóstico por imagem , Enfisema/genética , Feminino , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Doença Pulmonar Obstrutiva Crônica/sangue , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/sangue , Índice de Gravidade de Doença , Tomografia Computadorizada EspiralRESUMO
BACKGROUND: Pulmonary exacerbations in alpha-1 antitrypsin deficiency (AATD) related lung disease are a significant contributor to disease burden, as with usual COPD. Separating the early stages of an exacerbation from the day-to-day variation in stable COPD is central to the concerns of both clinicians and patients and has been identified as a research priority by NIHR. Clinical tools that distinguish baseline symptoms from those of an exacerbation could allow early and appropriate treatment of AECOPD to reduce the impact and potentially may slow disease progression thereby improving survival and quality of life. Candidate tools include symptom diaries and biomarkers of infection and acute inflammation. Urinary biomarkers of AECOPD have yet to be explored in AATD related COPD. METHODS: 55 patients with AATD related lung disease with a history of 2 or more AECOPD in the preceding year were prospectively followed for 18 months. Each patient recorded symptom scores daily via an electronic symptom diary (eDiary) based on Bronkotest. Urinary biomarkers for AAT, NE, CRP, TIMP1 and desmosine were measured weekly using a home urinary lateral flow device. During self-reported AECOPD patients were asked to perform urine analysis on the first 7 consecutive days. RESULTS: Type I Anthonisen exacerbations and episodes occurring in autumn/winter lasted longer than Type II/III exacerbations and spring/summer episodes respectively. Median urinary CRP concentration across all study participants increased during Type I AECOPD. eDiary adherence was 68% over a median of 17.8 months (IQR 15.7 to 18.5). CONCLUSIONS: Use of an eDiary and urinary biomarkers to detect and characterise AECOPD remotely in AATD related lung disease is feasible over a prolonged period and paves the way for precision detection of exacerbations.
Assuntos
Doença Pulmonar Obstrutiva Crônica , Deficiência de alfa 1-Antitripsina , Humanos , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Qualidade de Vida , Pulmão , Deficiência de alfa 1-Antitripsina/complicações , Deficiência de alfa 1-Antitripsina/diagnóstico , Deficiência de alfa 1-Antitripsina/tratamento farmacológico , Progressão da Doença , Biomarcadores , alfa 1-AntitripsinaRESUMO
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is characterised by airflow obstruction that is not fully reversible and is a major global cause of morbidity and mortality. The most widely used marker of disease severity and progression is FEV1. However, FEV1 correlates poorly with both symptoms and other measures of disease progression and thus there is an urgent need for other biological markers to better characterise individuals with COPD. Fibrinogen is an acute phase plasma protein that has emerged as a promising biomarker in COPD. Here we review the current clinical evidence linking fibrinogen with COPD and its associated co-morbidities and discuss its potential utility as a biomarker. METHODS: Searches for appropriate studies were undertaken on PubMed using search terms fibrinogen, COPD, emphysema, chronic bronchitis, FEV1, cardiovascular disease, exacerbation and mortality. RESULTS: There is strong evidence of an association between fibrinogen and the presence of COPD, the presence and frequency of exacerbations and with mortality. Fibrinogen is associated with disease severity but does not predict lung function decline, a measure used as a surrogate for disease activity. The role of fibrinogen in identifying inflammatory co morbidities, particularly cardiovascular disease, remains unclear. Fibrinogen is reduced by p38 mitogen-activated protein kinase inhibitors in individuals with stable disease and by oral corticosteroids during exacerbations. CONCLUSIONS: Fibrinogen is likely to be a useful biomarker to stratify individuals with COPD into those with a high or low risk of future exacerbations and may identify those with a higher risk of mortality.
Assuntos
Biomarcadores/sangue , Fibrinogênio/análise , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Progressão da Doença , Humanos , Índice de Gravidade de DoençaRESUMO
RATIONALE: Accurate prediction of mortality helps select patients for interventions aimed at improving outcome. OBJECTIVES: Because chronic obstructive pulmonary disease is characterized by low-grade systemic inflammation, we hypothesized that addition of inflammatory biomarkers to established predictive factors will improve accuracy. METHODS: A total of 1,843 patients enrolled in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints study were followed for 3 years. Kaplan-Meier curves, log-rank analysis, and Cox proportional hazards analyses determined the predictive value for mortality of clinical variables, while C statistics assessed the added discriminative power offered by addition of biomarkers. MEASUREMENTS AND MAIN RESULTS: At recruitment we measured anthropometrics, spirometry, 6-minute walk distance, dyspnea, BODE index, history of hospitalization, comorbidities, and computed tomography scan emphysema. White blood cell and neutrophil counts, serum or plasma levels of fibrinogen, chemokine ligand 18, surfactant protein D, C-reactive protein, Clara cell secretory protein-16, IL-6 and -8, and tumor necrosis factor-α were determined at recruitment and subsequent visits. A total of 168 of the 1,843 patients (9.1%) died. Nonsurvivors were older and had more severe airflow limitation, increased dyspnea, higher BODE score, more emphysema, and higher rates of comorbidities and history of hospitalizations. The best predictive model for mortality using clinical variables included age, BODE, and hospitalization history (C statistic of 0.686; P < 0.001). One single biomarker (IL-6) significantly improved the C statistic to 0.708, but this was further improved to 0.726 (P = 0.003) by the addition of all biomarkers. CONCLUSIONS: The addition of a panel of selected biomarkers improves the ability of established clinical variables to predict mortality in chronic obstructive pulmonary disease. Clinical trial registered with www.clinicaltrials.gov (NCT00292552).
Assuntos
Biomarcadores/sangue , Técnicas de Apoio para a Decisão , Doença Pulmonar Obstrutiva Crônica/mortalidade , Adulto , Idoso , Feminino , Hospitalização , Humanos , Inflamação/sangue , Inflamação/complicações , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicaçõesRESUMO
AIMS: Lipopolysaccharide (LPS) is a TLR4 agonist which activates NFκB dependent cytokine production. We investigated LPS inhalation in healthy smokers as a model of COPD bacterial exacerbations. We studied safety, reproducibility, the translocation of the NFκB subunit p65 in sputum cells and changes in systemic biomarkers of inflammation. METHODS: Twelve smokers inhaled 5 and 30 µg LPS and safety was monitored over 24 h. IL-6, CRP, CCl-18, SP-D, CC-16 and ß-defensin 2 were measured in serum samples collected at baseline, 4, 8 and 24 h. Sputum was induced at baseline, 6 and 24 h for cell counts and p65 expression. Repeated challenges were performed after a 2 week interval in 10 smokers. RESULTS: LPS inhalation was well tolerated. Significant increases occurred in sputum neutrophil counts with both doses, with a maximum increase of 21.5% at 6 h after 30 µg which was reproducible, r(i ) (intraclass correlation coefficient) = 0.88. LPS increased sputum cell nuclear p65 translocation and phospho-p65 expression. All of the serum biomarkers increased following challenge but with different temporal patterns. DISCUSSION: Inhaled LPS challenge in smokers causes pulmonary and systemic inflammation that involves NFκB activation. This appears to be a suitable model for studying bacterial exacerbations of COPD.
Assuntos
Lipopolissacarídeos/administração & dosagem , Pulmão/efeitos dos fármacos , Doença Pulmonar Obstrutiva Crônica/induzido quimicamente , Fumar , Escarro/imunologia , Administração por Inalação , Biomarcadores/metabolismo , Quimiocinas CC/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Exposição por Inalação , Pulmão/imunologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Doença Pulmonar Obstrutiva Crônica/sangue , Proteína D Associada a Surfactante Pulmonar/sangue , Fator de Transcrição RelA/sangue , Uteroglobina/sangue , beta-Defensinas/sangueRESUMO
RATIONALE: There are no accepted blood-based biomarkers in chronic obstructive pulmonary disease (COPD). Pulmonary and activation-regulated chemokine (PARC/CCL-18) is a lung-predominant inflammatory protein that is found in serum. OBJECTIVES: To determine whether PARC/CCL-18 levels are elevated and modifiable in COPD and to determine their relationship to clinical end points of hospitalization and mortality. METHODS: PARC/CCL-18 was measured in serum samples from individuals who participated in the ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) and LHS (Lung Health Study) studies and a prednisolone intervention study. MEASUREMENTS AND MAIN RESULTS: Serum PARC/CCL-18 levels were higher in subjects with COPD than in smokers or lifetime nonsmokers without COPD (105 vs. 81 vs. 80 ng/ml, respectively; P < 0.0001). Elevated PARC/CCL-18 levels were associated with increased risk of cardiovascular hospitalization or mortality in the LHS cohort and with total mortality in the ECLIPSE cohort. CONCLUSIONS: Serum PARC/CCL-18 levels are elevated in COPD and track clinical outcomes. PARC/CCL-18, a lung-predominant chemokine, could be a useful blood biomarker in COPD.
Assuntos
Quimiocinas CC/sangue , Doença Pulmonar Obstrutiva Crônica/sangue , Anti-Inflamatórios/uso terapêutico , Biomarcadores/sangue , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prednisolona/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Fatores de Risco , Fumar/sangueRESUMO
RATIONALE: Exacerbations of chronic obstructive pulmonary disease (COPD) are heterogeneous with respect to inflammation and etiology. OBJECTIVES: Investigate biomarker expression in COPD exacerbations to identify biologic clusters and determine biomarkers that recognize clinical COPD exacerbation phenotypes, namely those associated with bacteria, viruses, or eosinophilic airway inflammation. METHODS: Patients with COPD were observed for 1 year at stable and exacerbation visits. Biomarkers were measured in sputum and serum. Viruses and selected bacteria were assessed in sputum by polymerase chain reaction and routine diagnostic bacterial culture. Biologic phenotypes were explored using unbiased cluster analysis and biomarkers that differentiated clinical exacerbation phenotypes were investigated. MEASUREMENTS AND MAIN RESULTS: A total of 145 patients (101 men and 44 women) entered the study. A total of 182 exacerbations were captured from 86 patients. Four distinct biologic exacerbation clusters were identified. These were bacterial-, viral-, or eosinophilic-predominant, and a fourth associated with limited changes in the inflammatory profile termed "pauciinflammatory." Of all exacerbations, 55%, 29%, and 28% were associated with bacteria, virus, or a sputum eosinophilia. The biomarkers that best identified these clinical phenotypes were sputum IL-1ß, 0.89 (area under receiver operating characteristic curve) (95% confidence interval [CI], 0.830.95); serum CXCL10, 0.83 (95% CI, 0.700.96); and percentage peripheral eosinophils, 0.85 (95% CI, 0.780.93), respectively. CONCLUSIONS: The heterogeneity of the biologic response of COPD exacerbations can be defined. Sputum IL-1ß, serum CXCL10, and peripheral eosinophils are biomarkers of bacteria-, virus-, or eosinophil-associated exacerbations of COPD. Whether phenotype-specific biomarkers can be applied to direct therapy warrants further investigation.
Assuntos
Doença Pulmonar Obstrutiva Crônica/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Bacterianas/metabolismo , Infecções Bacterianas/microbiologia , Biomarcadores/sangue , Biomarcadores/metabolismo , Quimiocina CXCL10/sangue , Análise por Conglomerados , Eosinófilos/metabolismo , Eosinófilos/microbiologia , Feminino , Humanos , Inflamação/metabolismo , Inflamação/microbiologia , Interleucina-1beta/metabolismo , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/metabolismo , Curva ROC , Índice de Gravidade de Doença , Escarro/metabolismo , Escarro/microbiologiaRESUMO
Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is characterized by partially reversible airflow obstruction. Serum surfactant protein D (SP-D) is synthesized by type II pneumocytes and Clara cells and participates in surfactant homeostasis and pulmonary host defense. Serum levels of SP-D are raised in individuals with COPD but there is no correlation between the serum level of SP-D and the severity of airflow obstruction. Serum SP-D is present in different forms that may have more utility as a biomarker for COPD. We report here the development of new monoclonal antibodies to full length and cleaved SP-D. We have assessed these and existing antibodies in 98 individuals with COPD recruited to the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) cohort. Our data show that neither monoclonal antibodies to full length nor cleaved SP-D provide additional information over that obtained with a polyclonal antibody. Moreover, levels of serum nitrosylated-SP-D did not correlate with serum level of SP-D or any clinical phenotype of COPD. The measurement of modified SP-D is of limited value in characterising individuals with COPD.
Assuntos
Anticorpos Monoclonais/imunologia , Doença Pulmonar Obstrutiva Crônica/sangue , Proteína D Associada a Surfactante Pulmonar/sangue , Proteína D Associada a Surfactante Pulmonar/imunologia , Adulto , Idoso , Animais , Biomarcadores/sangue , Progressão da Doença , Volume Expiratório Forçado , Humanos , Camundongos , Pessoa de Meia-Idade , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Estatísticas não Paramétricas , Capacidade VitalRESUMO
Chemoprevention is a promising anti-cancer approach with reduced secondary effects in comparison to classical chemotherapy. Curcumin, one of the most studied chemopreventive agents, is a natural compound extracted from Curcuma longa L. that allows suppression, retardation or inversion of carcinogenesis. Curcumin is also described as an anti-tumoral, anti-oxidant and anti-inflammatory agent capable of inducing apoptosis in numerous cellular systems. In this review, we describe both properties and mode of action of curcumin on carcinogenesis, gene expression mechanisms and drug metabolism.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Quimioprevenção , Curcumina/farmacologia , Neoplasias/prevenção & controle , Transformação Celular Neoplásica/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Ativação Enzimática , Humanos , NF-kappa B/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidoresRESUMO
Glutathione S-transferases (GST) are involved in cellular protection against xenobiotics, oxidative stress as well as in resistance against chemotherapeutic compounds such as doxorubicin. Levels of human placental type GSTP1-1 are known to be increased in many tumors and hematopoietic diseases. In this work, we compare transcriptional mechanisms in cells that express or not GSTP1-1. Transient transfection assays are used to show that different GST-promoter reporter constructs generate cell-type specific levels of luciferase activity. In expressing cells, transcriptional activity is strongly dependent on AP-1 binding elements within the -65 to -75 bp region of the GSTP1 gene as shown by site-directed mutagenesis. Electrophoretic mobility shift assays show that DNA binding activity is exclusively observed in GSTP1-1-expressing cells and is increased after stimulation with hydrogen peroxide, TPA, tert-butylhydroquinone and doxorubicin. Non-expressing cells present neither constitutive nor inducible AP-1 binding. Taken together, our results provide evidence for the induction of the GSTP1 gene via AP-1 binding activity in leukemia cells and contribute to a better understanding of the molecular events regulating genes involved in drug resistance mechanisms.
Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glutationa Transferase/biossíntese , Isoenzimas/biossíntese , Fator de Transcrição AP-1/metabolismo , Sítios de Ligação , Doxorrubicina/farmacologia , Ensaio de Desvio de Mobilidade Eletroforética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glutationa S-Transferase pi , Glutationa Transferase/genética , Humanos , Peróxido de Hidrogênio/farmacologia , Hidroquinonas/farmacologia , Isoenzimas/genética , Células Jurkat , Células K562 , Leucemia , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição AP-1/biossíntese , Fator de Transcrição AP-1/genética , Transcrição Gênica , Transfecção , Células U937RESUMO
Glutathione S-transferases (GSTs) play an important role in the protection of cells against xenobiotics and lipid hydroperoxides generated by oxidative stress. In human, the GSTP1-1 expression is commonly increased in many tumors and involved in the development of antineoplastic drug resistance. Reactive oxygen species are released at inflammation sites and oxidative stress conditions enhance the expression of genes encoding antioxidant enzymes such as GSTs. Here we investigated the regulation of the GSTP1-1 gene expression in the K562 cell line by nuclear factor kappaB (NF-kappaB) and the pro-inflammatory cytokine tumor necrosis factor alpha (TNFalpha). By studying GSTP1-1 mRNA expression and NF-kappaB/GSTP1-1 promoter interactions, we showed the implication of NF-kappaB in the GSTP1-1 gene expression and we described a new specific TNFalpha-inducible NF-kappaB binding site upstream of the minimal promoter. Moreover, TNFalpha treatment as well as cotransfection of NF-kappaB signaling pathway intermediates induced an activation of the GSTP1-1 gene promoter in K562 cells. Site-directed mutagenesis of the NF-kappaB site strongly inhibited TNFalpha- and NF-kappaBp65-induced promoter activation. Altogether, we showed that a sequence located at -323/-314 within the GSTP1-1 promoter bound NF-kappaB p50/65 and p65/p65 dimers and that this kappaB site was involved in the regulation of the gene by TNFalpha.
Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glutationa Transferase/metabolismo , Isoenzimas/metabolismo , NF-kappa B/fisiologia , Nitrilas , Sulfonas , Fator de Necrose Tumoral alfa/farmacologia , Sítios de Ligação , Glutationa S-Transferase pi , Glutationa Transferase/genética , Humanos , Isoenzimas/genética , Leucemia , Compostos Orgânicos/farmacologia , Regiões Promotoras Genéticas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Células Tumorais CultivadasRESUMO
GSTP1-1 gene expression mechanisms were investigated in hemin-induced erythroid differentiation of K562 cells. Hemoglobin production during differentiation was followed by a significant increase in GSTP1-1 mRNA (1.7-fold, P < 0.01) and protein (1.2-fold, P < 0.01) after 4 days of induction. This increase in mRNA production was not due to transcriptional up-regulation by GATA-1 previously shown to regulate GSTP1-1 during erythroid and megakaryocytic differentiation. Moreover, a drastic decrease in differentiation-specific GATA-1 mRNA expression was correlated to a reduction in GATA-1 promoter binding activity. Neither AP-1 nor NF-kappaB transcription factor binding activities could provide an explanation to the GSTP1-1 mRNA overexpression in hemin-treated cells. GSTP1-1 mRNA stability analysis using actinomycin D as an inhibitor of mRNA neosynthesis showed that mRNA half-life was doubled in hemin-induced erythroid differentiation of K562 cells. These results allow us to add stabilization of GSTP1-1 mRNA as a novel regulatory mechanism during hemin-mediated differentiation of K562 cells.
Assuntos
Aciltransferases/metabolismo , Diferenciação Celular/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Hemina/farmacologia , Aciltransferases/genética , DNA/efeitos dos fármacos , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Eritrócitos/efeitos dos fármacos , Fatores de Ligação de DNA Eritroide Específicos , Fator de Transcrição GATA1 , Meia-Vida , Humanos , Células K562 , NF-kappa B/metabolismo , Estabilidade de RNA , RNA Mensageiro/metabolismo , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/metabolismo , Células Tumorais CultivadasRESUMO
Expression of glutathione S-transferase P1-1 (GSTP1-1) is correlated to carcinogenesis and resistance of cancer cells against chemotherapeutic agents. Curcumin, a natural compound extracted from Curcuma longa, has shown strong antioxidant and anticancer properties and also the ability to regulate a wide variety of genes that require activating protein 1 and nuclear factor kappaB (NF-kappaB) activation. In the present study, we examined the inhibitory effect of curcumin on the expression of GSTP1-1 mRNA as well as protein, and we correlated this inhibition with the apoptotic effect of curcumin on K562 leukemia cells. Curcumin efficiently inhibited the tumour necrosis factor alpha- and phorbol ester-induced binding of AP-1 and NF-kappaB transcription factors to sites located on the GSTP1-1 gene promoter. TNFalpha-induced GSTP1-1 promoter activity was also inhibited by curcumin as shown by reporter gene assay. In parallel, curcumin induced pro-caspases 8 and 9 as well as poly ADP ribose polymerase cleavage and thus leading to apoptosis in K562 cells. Our results overall add a novel role for curcumin as this chemoprotective compound could contribute to induce apoptosis by its ability to inhibit the GSTP1-1 expression at the level of transcription.
Assuntos
Apoptose , Curcumina/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/antagonistas & inibidores , Isoenzimas/antagonistas & inibidores , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Interações Medicamentosas , Glutationa S-Transferase pi , Humanos , Células K562 , NF-kappa B/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição AP-1/metabolismo , Transcrição Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Glutathione S-transferase P1-1 (GSTP1-1) is a phase II drug metabolism enzyme implicated in carcinogenesis and development of resistance to anti-cancer drugs. It was previously shown that both activating protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB) are involved in its regulation. In the present study we examined the inhibitory effect of several chemopreventive agents on the tumor necrosis factor (TNF) alpha- or 12-O-tetradecanoylphorbol 13 acetate (TPA)-induced promoter activity of GSTP1-1, as demonstrated by transient transfection experiments in K562 and U937 leukemia cells. Our results provide evidence for a differential effect of chemopreventive agents such as beta-lapachone, emodin, sanguinarine and capsaicin, which significantly inhibit reporter gene expression as well as TNFalpha- and TPA-induced binding of AP-1 and NF-kappaB, whereas trans-anethole and silymarin do not produce any inhibitory effect. Our results demonstrate the ability of selected chemopreventive agents to decrease GSTP1-1 gene expression mechanisms and could thus contribute to reduce the incidence of glutathione related drug resistance in human leukemia.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Expressão Gênica/efeitos dos fármacos , Glutationa Transferase/metabolismo , Isoenzimas/metabolismo , NF-kappa B/antagonistas & inibidores , Fator de Transcrição AP-1/antagonistas & inibidores , Quimioprevenção , Interações Medicamentosas , Glutationa S-Transferase pi , Glutationa Transferase/genética , Humanos , Isoenzimas/genética , Células K562 , NF-kappa B/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição AP-1/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Células U937RESUMO
To investigate the stability of curcumin in physiological media, the absorption variation of a curcumin solution was measured in 0.1% and 10% FCS. Under daylight conditions, curcumin degraded very rapidly in 0.1% FCS and was found to be more stable in higher serum concentrations. Under dark conditions, almost no decomposition could be observed after 2 h, whether the measurements were performed in 0.1% or 10% FCS. Furthermore, depending on the medium concentration, differential glutathione S-transferase P1-1 mRNA expression could be observed in K562 cells after incubation with curcumin. Indeed, incubation in 0.1% FCS led to a decrease of mRNA expression, whereas incubation in 10% FCS induced an increase of mRNA production.
Assuntos
Curcumina/farmacologia , Glutationa Transferase/genética , RNA Mensageiro/genética , Sangue , Northern Blotting , Meios de Cultura , Humanos , Células K562 , RNA Mensageiro/metabolismoRESUMO
Apoptosis is a type of cell death that has been observed and studied for more than a century. The process of apoptosis was described as "programmed cell death" in 1964, and the term apoptosis, from a Greek word meaning "to fall away from" and describing the fall of dead leaves from trees in autumn, was only coined in 1972. During the last 30 years, this type of cell death has been extensively investigated and the molecular mechanisms underlying this cell suicide well characterized. Apoptosis is a physiological phenomenon necessary to tissue and body genesis and homeostasis, but defects in its regulation may cause numerous diseases, including cancer. Investigating the mechanisms of apoptosis is thus important to discover new cellular regulators that could be potential targets for new death-inducing drugs.
Assuntos
Apoptose/fisiologia , Animais , Homeostase , Humanos , Modelos Biológicos , Neoplasias/fisiopatologia , Receptores do Fator de Necrose Tumoral/fisiologiaRESUMO
BACKGROUND: Emphysema is a key contributor to airflow limitation in chronic obstructive pulmonary disease (COPD) and can be quantified using CT scanning. We investigated the change in CT lung density in a longitudinal, international cohort of patients with COPD. We also explored the potential relation between emphysema and patient characteristics, and investigated if certain circulating biomarkers were associated with decline in CT lung density. METHODS: We used a random coefficient model to assess predictors of both CT lung density and its longitudinal change over 3 years in 1928 patients with COPD enrolled in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study. Lung density was measured for every voxel in the CT scan and after correcting for lung volume was expressed as the density at lowest 15th percentile point of the distribution. This study is registered with ClinicalTrials.gov, number NCT00292552. FINDINGS: Lung density at baseline was influenced by age, sex, body-mass index, current smoking status and smoking history, and severity of airflow limitation. The observed decline in lung density was variable (mean decline -1·13 g/L [SE 0·06] per year). The annual decline in lung density was more rapid in women (additional -0·41 [SE 0·14] g/L per year, p=0·003) than men and in current smokers (additional -0·29 [SE 0·14] g/L per year, p=0·047) than in former smokers. Circulating levels of the biomarkers surfactant protein D (SP-D) and soluble receptor for advanced glycation endproduct (sRAGE) were significantly associated with both baseline lung density and its decline over time. INTERPRETATION: This study shows that decline in lung density in COPD can be measured, that it is variable, and related to smoking and gender. We identified potential biochemical predictors of the presence and progression of emphysema. FUNDING: GlaxoSmithKline.
Assuntos
Biomarcadores/sangue , Enfisema , Pulmão , Doença Pulmonar Obstrutiva Crônica , Fumar/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Progressão da Doença , Enfisema/diagnóstico por imagem , Enfisema/etiologia , Feminino , Humanos , Inflamação/sangue , Inflamação/etiologia , Modelos Logísticos , Estudos Longitudinais , Pulmão/patologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/psicologia , Proteína D Associada a Surfactante Pulmonar/sangue , Ventilação Pulmonar , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/sangue , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Abandono do Hábito de FumarRESUMO
Surfactant protein D (SP-D) plays an important role in lung host defence. SP-D levels have been shown to be depleted in cystic fibrosis (CF) patients. A recombinant fragment of the human SP-D (rfhSP-D) which consist of a hydrophobic neck and a CRD has been shown to be active in vivo and partially reverses the symptoms of the SP-D deficiency in the lungs when administered to SP-D knock-out mice. In this paper we studied the in vitro effect of different proteolytic enzymes commonly found in CF patients lungs, such as neutrophil elastase, cathepsin G and protease 3 as well as Pseudomonas elastase, on rfhSP-D. It was also shown that cleavage was inhibited by physiological concentration of calcium. When Western blot was compared with ELISA, we show that an anti-SP-D ELISA is a not a reliable assay of functional SP-D levels since non-functional fragments of SP-D are also detected. Thus, ELISA cannot be used as a reliable "diagnostic" tool for SP-D deficiency. Finally, we observe that SP-D is not cleaved in control patients but is degraded in about half the samples from cystic fibrosis patients, indicating that degradation of endogenous SP-D, by enzymes present in CF bronchioalveolar lavage fluid (BALF), may lead to deficiency of the protein as seen in CF and therefore rfhSP-D may be a useful future therapy.
Assuntos
Cálcio/metabolismo , Fibrose Cística/metabolismo , Fragmentos de Peptídeos/metabolismo , Pseudomonas/enzimologia , Proteína D Associada a Surfactante Pulmonar/metabolismo , Adolescente , Proteínas de Bactérias/metabolismo , Western Blotting , Líquido da Lavagem Broncoalveolar/química , Criança , Pré-Escolar , Fibrose Cística/diagnóstico , Fibrose Cística/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Elastase Pancreática/metabolismo , Fragmentos de Peptídeos/genética , Peptídeo Hidrolases/metabolismo , Proteína D Associada a Surfactante Pulmonar/genética , Transgenes/genéticaRESUMO
Members of the serine protease inhibitor (serpin) superfamily are found in all branches of life and play an important role in the regulation of enzymes involved in proteolytic cascades. Mutants of the serpins result in a delay in folding, with unstable intermediates being cleared by endoplasmic reticulum-associated degradation. The remaining protein is either fully folded and secreted or retained as ordered polymers within the endoplasmic reticulum of the cell of synthesis. This results in a group of diseases termed the serpinopathies, which are typified by mutations of α(1)-antitrypsin and neuroserpin in association with cirrhosis and the dementia familial encephalopathy with neuroserpin inclusion bodies, respectively. Current evidence strongly suggests that polymers of mutants of α(1)-antitrypsin and neuroserpin are linked by the sequential insertion of the reactive loop of one molecule into ß-sheet A of another. The ordered structure of the polymers within the endoplasmic reticulum stimulates nuclear factor-kappa B by a pathway that is independent of the unfolded protein response. This chronic activation of nuclear factor-kappa B may contribute to the cell toxicity associated with mutations of the serpins. We review the pathobiology of the serpinopathies and the development of novel therapeutic strategies for treating the inclusions that cause disease. These include the use of small molecules to block polymerization, stimulation of autophagy to clear inclusions and stem cell technology to correct the underlying molecular defect.