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1.
Chemosphere ; 239: 124667, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499299

RESUMO

Exposure to air pollution can have both short-term and long-term effects on health. However, the relationships between specific pollutants and their effects can be obscured by characteristics of both the pollution and the exposed population. One way of elucidating the relationships is to link exposures and internal changes at the level of the individual. To this end, we combined personal exposure monitoring (59 individuals, Oxford Street II crossover study) with mass-spectrometry-based analyses of putative serum albumin adducts (fixed-step selected reaction monitoring). We attempted to infer adducts' identities using data from another, higher-resolution mass spectrometry method, and were able to detect a semi-synthetic standard with both methods. A generalised least squares regression method was used to test for associations between amounts of adducts and pollution measures (ambient concentrations of nitrogen dioxide and particulate matter), and between amounts of adducts and short-term health outcomes (measures of lung health and arterial stiffness). Amounts of some putative adducts (e.g., one with a positive mass shift of ∼143 Da) were associated with exposure to pollution (11 associations), and amounts of other adducts were associated with health outcomes (eight associations). Adducts did not appear to provide a link between exposures and short-term health outcomes.

2.
J Innate Immun ; 12(1): 1-16, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31786568

RESUMO

Lung innate immunity is the first line of defence against inhaled allergens, pathogens and environmental pollutants. Cellular metabolism plays a key role in innate immunity. Catabolic pathways, including glycolysis and fatty acid oxidation (FAO), are interconnected with biosynthetic and redox pathways. Innate immune cell activation and differentiation trigger extensive metabolic changes that are required to support their function. Pro-inflammatory polarisation of macrophages and activation of dendritic cells, mast cells and neutrophils are associated with increased glycolysis and a shift towards the pentose phosphate pathway and fatty acid synthesis. These changes provide the macromolecules required for proliferation and inflammatory mediator production and reactive oxygen species for anti-microbial effects. Conversely, anti-inflammatory macrophages use primarily FAO and oxidative phosphorylation to ensure efficient energy production and redox balance required for prolonged survival. Deregulation of metabolic reprogramming in lung diseases, such as asthma and chronic obstructive pulmonary disease, may contribute to impaired innate immune cell function. Understanding how innate immune cell metabolism is altered in lung disease may lead to identification of new therapeutic targets. This is important as drugs targeting a number of metabolic pathways are already in clinical development for the treatment of other diseases such as cancer.

3.
Respir Med ; 161: 105817, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31790928

RESUMO

BACKGROUND: Asthma prevalence is 339 million globally. 'Severe asthma' (SA) comprises subjects with uncontrolled asthma despite proper management. OBJECTIVES: To compare asthma from diverse ethnicities and environments. METHODS: A cross-sectional analysis of two adult cohorts, a Brazilian (ProAR) and a European (U-BIOPRED). U-BIOPRED comprised of 311 non-smoking with Severe Asthma (SAn), 110 smokers or ex-smokers with SA (SAs) and 88 mild to moderate asthmatics (MMA) while ProAR included 544 SA and 452 MMA. Although these projects were independent, there were similarities in objectives and methodology, with ProAR adopting operating procedures of U-BIOPRED. RESULTS: Among SA subjects, age, weight, proportion of former smokers and FEV1 pre-bronchodilator were similar. The proportion of SA with a positive skin prick tests (SPT) to aeroallergens, the scores of sino-nasal symptoms and quality of life were comparable. In addition, blood eosinophil counts (EOS) and the % of subjects with EOS > 300 cells/µl were not different. The Europeans with SA however, were more severe with a greater proportion of continuous oral corticosteroids (OCS), worse symptoms and more frequent exacerbations. FEV1/FVC pre- and post-bronchodilator were lower among the Europeans. The MMA cohorts were less comparable in control and treatment, but similar in the proportion of allergic rhinitis, gastroesophageal reflux disease and EOS >3%. CONCLUSIONS: ProAR and U-BIOPRED cohorts, with varying severity, ethnicity and environment have similarities, which provide the basis for global external validation of asthma phenotypes. This should stimulate collaboration between asthma consortia with the aim of understanding SA, which will lead to better management.

4.
Front Immunol ; 10: 2169, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31608051

RESUMO

Ozone exposure causes irritation, airway hyperreactivity (AHR), inflammation of the airways, and destruction of alveoli (emphysema), the gas exchange area of the lung in human and mice. This review focuses on the acute disruption of the respiratory epithelial barrier in mice. A single high dose ozone exposure (1 ppm for 1 h) causes first a break of the bronchiolar epithelium within 2 h with leak of serum proteins in the broncho-alveolar space, disruption of epithelial tight junctions and cell death, which is followed at 6 h by ROS activation, AHR, myeloid cell recruitment, and remodeling. High ROS levels activate a novel PGAM5 phosphatase dependent cell-death pathway, called oxeiptosis. Bronchiolar cell wall damage and inflammation upon a single ozone exposure are reversible. However, chronic ozone exposure leads to progressive and irreversible loss of alveolar epithelial cells and alveoli with reduced gas exchange space known as emphysema. It is further associated with chronic inflammation and fibrosis of the lung, resembling other environmental pollutants and cigarette smoke in pathogenesis of asthma, and chronic obstructive pulmonary disease (COPD). Here, we review recent data on the mechanisms of ozone induced injury on the different cell types and pathways with a focus on the role of the IL-1 family cytokines and the related IL-33. The relation of chronic ozone exposure induced lung disease with asthma and COPD and the fact that ozone exacerbates asthma and COPD is emphasized.

5.
Eur Respir J ; 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601713

RESUMO

Little is known about the characteristics and treatments of patients with severe asthma across Europe but both are likely to vary. This is the first study in the ERS Severe Heterogeneous Asthma Research collaboration, Patient-centred (SHARP) and it is designed to explore these variations. Therefore, we aimed to compare characteristics of patients in European severe asthma registries and treatments before starting biologicals. This was a cross-sectional retrospective analysis of aggregated data from 11 national severe asthma registries that joined SHARP with established patient databases. Analysis of data from 3233 patients showed many differences in characteristics and life style factors. Current smokers ranged from 0% (Poland, PL, Sweden, SE) to 9.5% (Belgium, BE), mean BMI ranged from 26.2 (Italy) to 30.6 kg·m-2 (UK) and the largest difference in mean pre-bronchodilator FEV1% pred. was 20.9% (Netherlands versus Hungary). Before starting biologicals patients were treated differently between countries: mean ICS dose ranged from 700 to 1335 µg·day-1 between those from Slovenia (SL) versus PL when starting anti-IL-5 antibody and from 772 to 1344 µg·day-1 in those starting anti-IgE (SL versus Spain). Maintenance OCS use ranged from 21.0% (BE) to 63.0% (SE) and from 9.1% (Denmark) to 56.1% (UK) in patients starting anti-IL-5 and anti-IgE, respectively. The severe asthmatic population in Europe is heterogeneous and differs in both clinical characteristics and treatment, often appearing not to comply with the current ERS/ATS guidelines definition of severe asthma. Treatment regimens before starting biologicals were different from inclusion criteria in clinical trials and varied between countries.

6.
Eur. respir. j ; 54(3): 1900588, Sept. 2019.
Artigo em Inglês | BIGG | ID: biblio-1026251

RESUMO

This document provides clinical recommendations for the management of severe asthma. Comprehensive evidence syntheses, including meta-analyses, were performed to summarise all available evidence relevant to the Task Force's questions. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach and the results were summarised in evidence profiles. The evidence syntheses were discussed and recommendations formulated by a multidisciplinary Task Force of asthma experts, who made specific recommendations on 6 specific questions. After considering the balance of desirable and undesirable consequences, quality of evidence, feasibility, and acceptability of various interventions, the Task Force made the following recommendations: 1) Suggest using anti-IL5 and anti IL-5Rα for severe uncontrolled adult eosinophilic asthma phenotypes; 2) suggest using blood eosinophil cut-point of ≥150/µL to guide anti-IL5 initiation in adult patients with severe asthma; and 3) Suggest considering specific eosinophil (≥260/µL) and FeNO (≥19.5 ppb) cutoffs to identify adolescents or adults with the greatest likelihood or response to anti-IgE therapy; 4) Suggest using inhaled tiotropium for adolescents and adults with severe uncontrolled asthma despite GINA step 4-5 or NAEPP step 5 therapies; 5) Suggest a trial of chronic macrolide therapy to reduce asthma exacerbations in persistently symptomatic or uncontrolled patients on GINA step 5 or NAEPP step 5 therapies, irrespective of asthma phenotype; 6) Suggest using anti-IL4/13 for adult patients with severe eosinophilic asthma, and for those with severe corticosteroid-dependent asthma regardless of blood eosinophil levels. These recommendations should be reconsidered as new evidence becomes available.


Assuntos
Humanos , Asma/complicações , Asma/diagnóstico , Asma/prevenção & controle , Estado Asmático/prevenção & controle
8.
Respir Med ; 157: 42-48, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31499296

RESUMO

BACKGROUND: Identification of asthma phenotypes facilitates our understanding of asthma pathobiologies. Phenotypes observed in homogenous Asian cohorts have distinct differences from those described in Caucasian cohorts, suggesting that ethnicity may influence phenotypic expression. Phenotypic clusters in a multi-ethnic Southeast Asian cohort have not been described before, and direct comparisons of these clusters within a single study may reveal how ethnicity affects phenotypic expression. METHODS: Six hundred and thirty adult asthma patients from two healthcare institutions in Singapore were randomly assigned in a 2:1 fashion to a test and validation cohort. Latent class analysis was performed on both cohorts using age of asthma onset, sex, ethnicity, smoking status, body mass index, lung function, blood eosinophil count, asthma control test score, and exacerbation frequency as input variables. Phenotypic clusters between the test and validation cohorts were compared RESULTS: Three clusters were identified in both the test and validation cohorts, with corresponding clusters of each cohort sharing similar characteristics. Ethnic representation and asthma control were significantly different between clusters. Cluster one comprised Chinese females with late-onset asthma and the best asthma control. Cluster two comprised non-Chinese females with obesity and the worst asthma control. Cluster three was multi-ethnic with the greatest proportion of atopic patients. CONCLUSION: We identified three phenotypic clusters in our multi-ethnic Southeast Asian population, with distinct differences in ethnicity which may be attributable to inherent differences in baseline characteristics among ethnic groups.

9.
Eur Respir J ; 2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31558662

RESUMO

This document provides clinical recommendations for the management of severe asthma. Comprehensive evidence syntheses, including meta-analyses, were performed to summarise all available evidence relevant to the Task Force's questions. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach and the results were summarised in evidence profiles. The evidence syntheses were discussed and recommendations formulated by a multidisciplinary Task Force of asthma experts, who made specific recommendations on 6 specific questions. After considering the balance of desirable and undesirable consequences, quality of evidence, feasibility, and acceptability of various interventions, the Task Force made the following recommendations: 1) Suggest using anti-IL5 and anti IL-5Rα for severe uncontrolled adult eosinophilic asthma phenotypes; 2) suggest using blood eosinophil cut-point of ≥150/µL to guide anti-IL5 initiation in adult patients with severe asthma; and 3) Suggest considering specific eosinophil (≥260/µL) and FeNO (≥19.5 ppb) cutoffs to identify adolescents or adults with the greatest likelihood or response to anti-IgE therapy; 4) Suggest using inhaled tiotropium for adolescents and adults with severe uncontrolled asthma despite GINA step 4-5 or NAEPP step 5 therapies; 5) Suggest a trial of chronic macrolide therapy to reduce asthma exacerbations in persistently symptomatic or uncontrolled patients on GINA step 5 or NAEPP step 5 therapies, irrespective of asthma phenotype; 6) Suggest using anti-IL4/13 for adult patients with severe eosinophilic asthma, and for those with severe corticosteroid-dependent asthma regardless of blood eosinophil levels. These recommendations should be reconsidered as new evidence becomes available.

10.
Allergy ; 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506971

RESUMO

BACKGROUND: Whether the clinical or pathophysiologic significance of the "treatable trait" high blood eosinophil count in COPD is the same as for asthma remains controversial. We sought to determine the relationship between the blood eosinophil count, clinical characteristics and gene expression from bronchial brushings in COPD and asthma. METHODS: Subjects were recruited into a COPD (emphysema versus airway disease [EvA]) or asthma cohort (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes, U-BIOPRED). We determined gene expression using RNAseq in EvA (n = 283) and Affymetrix microarrays in U-BIOPRED (n = 85). We ran linear regression analysis of the bronchial brushings transcriptional signal versus blood eosinophil counts as well as differential expression using a blood eosinophil > 200 cells/µL as a cut-off. The false discovery rate was controlled at 1% (with continuous values) and 5% (with dichotomized values). RESULTS: There were no differences in age, gender, lung function, exercise capacity and quantitative computed tomography between eosinophilic versus noneosinophilic COPD cases. Total serum IgE was increased in eosinophilic asthma and COPD. In EvA, there were 12 genes with a statistically significant positive association with the linear blood eosinophil count, whereas in U-BIOPRED, 1197 genes showed significant associations (266 positive and 931 negative). The transcriptome showed little overlap between genes and pathways associated with blood eosinophil counts in asthma versus COPD. Only CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts. CONCLUSION: Despite shared "treatable traits" between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different.

11.
Eur Respir J ; 54(3)2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31467120

RESUMO

Despite the use of effective medications to control asthma, severe exacerbations in asthma are still a major health risk and require urgent action on the part of the patient and physician to prevent serious outcomes such as hospitalisation or death. Moreover, severe exacerbations are associated with substantial healthcare costs and psychological burden, including anxiety and fear for patients and their families. The European Academy of Allergy and Clinical Immunology (EAACI) and the European Respiratory Society (ERS) set up a task force to search for a clear definition of severe exacerbations, and to also define research questions and priorities. The statement includes comments from patients who were members of the task force.

12.
Oxid Med Cell Longev ; 2019: 7450151, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31281589

RESUMO

Exposure to fine particulate matter (PM2.5) has been associated with lung inflammation and airway hyperresponsiveness (AHR). Transient receptor potential (TRP) vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1) both may play important roles in lung inflammation and AHR. We investigated whether PM2.5-induced lung inflammation and AHR could be prevented by blocking TRPV1 and TRPA1 channels. Mice were injected intraperitoneally with AMG9810 (30 mg/kg, a TRPV1 antagonist) or A967079 (30 mg/kg, a TRPA1 antagonist) or their combination or vehicle (PBS) one hour before intranasal instillation of PM2.5 (7.8 mg/kg) or vehicle (PBS) for two consecutive days, and then the mice were studied 24 h later. All pretreatments inhibited PM2.5-induced AHR and inflammatory infiltration in the lung tissue and decreased inflammatory cytokine levels in the bronchoalveolar lavage fluid, together with oxidant levels in the lung. AMG9810 inhibited MFF expression and increased MFN2 expression while A967079 inhibited DRP1 expression and increased OPA1 expression; combined pretreatment reduced MFF and DPR1 expression and increased MFN2 and OPA1 expression. All pretreatments inhibited the activation of the TLR4/NF-κB pathway, while A967079 alone, and combined with AMG9810 also reduced the activation of the NLRP3/caspase-1 pathway. Both TRPV1 and TRPA1 channels play an important role in PM2.5-induced lung inflammation and AHR. However, inhibition of the TRPA1 channel or combined inhibition of TRPA1 and TRPV1 channels resulted in greater inhibitory effect on PM2.5-induced lung injury through regulating the mitochondrial fission/fusion proteins and inhibiting the TLR4/NF-κB and NLRP3/caspase-1 pathways.

13.
Front Immunol ; 10: 1610, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354743

RESUMO

Epidemiological and challenge studies in healthy subjects and in individuals with asthma highlight the health impact of environmental ozone even at levels considered safe. Acute ozone exposure in man results in sputum neutrophilia in 30% of subjects particularly young children, females, and those with ongoing cardiopulmonary disease. This may be associated with systemic inflammation although not in all cases. Chronic exposure amplifies these effects and can result in the formation of asthma-like symptoms and immunopathology. Asthmatic patients who respond to ozone (responders) induce a greater number of genes in bronchoalveolar (BAL) macrophages than healthy responders with up-regulation of inflammatory and immune pathways under the control of cytokines and chemokines and the enhanced expression of remodeling and repair programmes including those associated with protease imbalances and cell-cell adhesion. These pathways are under the control of several key transcription regulatory factors including nuclear factor (NF)-κB, anti-oxidant factors such as nuclear factor (erythroid-derived 2)-like 2 NRF2, the p38 mitogen activated protein kinase (MAPK), and priming of the immune system by up-regulating toll-like receptor (TLR) expression. Murine and cellular models of acute and chronic ozone exposure recapitulate the inflammatory effects seen in humans and enable the elucidation of key transcriptional pathways. These studies emphasize the importance of distinct transcriptional networks in driving the detrimental effects of ozone. Studies indicate the critical role of mediators including IL-1, IL-17, and IL-33 in driving ozone effects on airway inflammation, remodeling and hyperresponsiveness. Transcription analysis and proof of mechanisms studies will enable the development of drugs to ameliorate the effects of ozone exposure in susceptible individuals.

14.
Clin Exp Allergy ; 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31310686

RESUMO

BACKGROUND: An elevated blood eosinophil count when asthma is stable predicts exacerbations and therapeutic response to corticosteroids or biologics targeting eosinophils. Few studies have examined the prognostic value of blood eosinophils measured at exacerbation. AIM: To elucidate the relationship between a spot blood eosinophil count-measured at the onset of a life-threatening asthma exacerbation-with indices of exacerbation severity and risk of subsequent exacerbations. METHODS: Real-world, retrospective review of all life-threatening asthma cases admitted at 4 public hospitals in Singapore between 2011-2015. We assessed the trends and correlations between blood eosinophil count on admission with arterial blood gas values, duration of mechanical ventilation, and risk of death, hypoxic ischemic encephalopathy or respiratory arrest. Risk of future exacerbations among survivors was modelled using Cox regression and survival curves. RESULTS: There were 376 index life-threatening exacerbations with median blood eosinophil count (5-95th percentiles) of 0.270 × 109 /L (0-1.410 × 109 /L). Arterial pH decreased and PCO2 increased with increasing eosinophil count. Duration of mechanical ventilation and risk of death, hypoxic ischaemic encephalopathy or respiratory arrest did not vary with eosinophils. Among 329 survivors who were followed-up over a median of 52 months, blood eosinophils ≥1.200 × 109 /L was associated with an increased hazard of emergency visits and/or admissions for asthma (hazard ratio 1.8, 95% confidence interval 1.1-2.9, P = .02). CONCLUSION: In this study of life-threatening asthma, we found that a spot blood eosinophil count correlates with severity of respiratory failure and predicts risk of subsequent exacerbations.

15.
Respir Res ; 20(1): 112, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170994

RESUMO

BACKGROUND: The differential sensitivity of cough to antitussive therapies implies the existence of heterogeneity in cough hypersensitivity, but how such heterogeneity is expressed across individual patients is poorly understood. We investigated the phenotypes of cough hypersensitivity by examining transient receptor potential ankyrin 1 (TRPA1)- and transient receptor potential vanilloid 1 (TRPV1)-mediated cough sensitivity in patients with chronic refractory cough. METHODS: Using a selective TRPA1 agonist, allyl isothiocyanate (AITC), we established an AITC cough challenge as a measure of TRPA1-mediated cough sensitivity. The AITC cough challenge and the widely used capsaicin (a selective TRPV1 agonist) cough challenge were performed with 250 patients with chronic refractory cough and 56 healthy subjects. The concentration of AITC or capsaicin solution causing at least two (C2) and five coughs (C5) was recorded. Cough sensitivity was expressed as the mean (95% confidence interval) of log C5, and cough hypersensitivity was defined as a log C5 value lower than that of healthy subjects. RESULTS: A distinct concentration-response effect of inhaled AITC was identified both in patients with chronic refractory cough and in healthy subjects. Cough sensitivity to AITC and capsaicin was significantly higher in patients than in healthy subjects (AITC: 2.42 [2.37-2.48] vs 2.72 [2.66-2.78] mM, p = 0.001; capsaicin: 1.87 [1.75-1.98] vs 2.53 [2.36-2.70] µM, p = 0.001) and was higher in females than in males for both healthy subjects and patients (all p < 0.05). Among the 234 patients who completed both challenges, 25 (10.7%) exhibited hypersensitivity to both AITC and capsaicin, 44 (18.8%) showed hypersensitivity to AITC only, 28 (11.9%) showed hypersensitivity to capsaicin only, and 137 (58.6%) exhibited hypersensitivity to neither. Those with TRPA1- and/or TRPV1-mediated hypersensitivity were predominantly female, while those without TRPA1- and TRPV1-mediated hypersensitivity were mainly male. CONCLUSIONS: Four phenotypes of cough hypersensitivity were identified by the activation of TRPV1 and TRPA1 channels, which supports the existence of heterogeneity in cough pathways and provides a new direction for personalized management of chronic refractory cough. TRIAL REGISTRATION: ClinicalTrials.gov NCT02591550 .

17.
Free Radic Res ; 53(7): 780-790, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31185753

RESUMO

Oxidative stress is a key mechanism underlying ozone-induced lung injury. Mitochondria can release mitochondrial reactive oxidative species (mtROS), which may lead to the activation of NLRP3 inflammasome. The goal of this study was to examine the roles of mtROS and NLRP3 inflammasome in acute ozone-induced airway inflammation and bronchial hyperresponsiveness (BHR). C57/BL6 mice (n = 8/group) were intraperitoneally treated with vehicle (phosphate buffered saline, PBS) or mitoTEMPO (mtROS inhibitor, 20 mg/kg), or orally treated with VX-765 (caspse-1 inhibitor, 100 mg/kg) 1 h before the ozone exposure (2.5 ppm, 3 h). Compared to the PBS-treated ozone-exposed mice, mitoTEMPO reduced the level of total malondialdehyde in bronchoalveolar lavage (BAL) fluid and increased the expression of mitochondrial complexes II and IV in the lung 24 h after single ozone exposure. VX-765 inhibited ozone-induced BHR, BAL total cells including neutrophils and eosinophils, and BAL inflammatory cytokines including IL-1α, IL-1ß, KC, and IL-6. Both mitoTEMPO and VX-765 reduced ozone-induced mtROS and inhibited capase-1 activity in lung tissue whilst VX-765 further inhibited DRP1 and MFF expression, increased MFN2 expression, and down-regulated caspase-1 expression in the lung tissue. These results indicate that acute ozone exposure induces mitochondrial dysfunction and NLRP3 inflammasome activation, while the latter has a critical role in the pathogenesis of ozone-induced airway inflammation and BHR.

18.
Biomed Res Int ; 2019: 1484736, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31119153

RESUMO

Background and Objective: Progressive pulmonary fibrosis is the main cause of death in patients with systemic sclerosis (SSc) with interstitial lung disease (ILD) and in those with idiopathic pulmonary fibrosis (IPF). Transforming growth factor-ß (TGF-ß) and NADPH oxidase- (NOX-) derived reactive oxygen species (ROS) are drivers of lung fibrosis. We aimed to determine the role of the epigenetic readers, bromodomain and extraterminal (BET) proteins in the regulation of redox balance in activated myofibroblasts. Methods: In TGF-ß-stimulated fibroblasts, we investigated the effect of the BET inhibitor JQ1 on the mRNA expression of the prooxidant gene NOX4 and the antioxidant gene superoxide dismutase (SOD2) by quantitative RT-PCR, the antioxidant transcription factor NF-E2-related factor 2 (Nrf2) activity by a reporter assay, and intracellular ROS levels by dichlorofluorescein staining. Myofibroblast activation was determined by α-smooth muscle actin immunocytochemistry. The role of specific BET protein isoforms in NOX4 gene regulation was studied by siRNA silencing and chromatin-immunoprecipitation. Results and Conclusions: Affymetrix gene array analysis revealed increased NOX4 and reduced SOD2 expression in SSc and IPF fibroblasts. SOD2 silencing in non-ILD control fibroblasts induced a profibrotic phenotype. TGF-ß increased NOX4 and inhibited SOD2 expression, while increasing ROS production and myofibroblast differentiation. JQ1 reversed the TGF-ß-mediated NOX4/SOD2 imbalance and Nrf2 inactivation and attenuated ROS production and myofibroblast differentiation. The BET proteins Brd3 and Brd4 were shown to bind to the NOX4 promoter and drive TGF-ß-induced NOX4 expression. Our data indicate a critical role of BET proteins in promoting redox imbalance and pulmonary myofibroblast activation and support BET bromodomain inhibitors as a potential therapy for fibrotic lung disease.


Assuntos
Fibrose Pulmonar Idiopática/genética , NADPH Oxidase 4/genética , Proteínas Nucleares/genética , Proteínas de Ligação a RNA/genética , Escleroderma Sistêmico/genética , Fatores de Transcrição/genética , Azepinas/farmacologia , Desdiferenciação Celular/genética , Proliferação de Células/genética , Epigênese Genética , Regulação da Expressão Gênica/genética , Humanos , Fibrose Pulmonar Idiopática/complicações , Fibrose Pulmonar Idiopática/patologia , Pulmão/metabolismo , Pulmão/patologia , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Fator 2 Relacionado a NF-E2/genética , Oxirredução , RNA Interferente Pequeno/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/patologia , Superóxido Dismutase/genética , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/farmacologia , Triazóis/farmacologia
19.
J Allergy Clin Immunol ; 144(1): 70-82, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30928653

RESUMO

BACKGROUND: Stratification by eosinophil and neutrophil counts increases our understanding of asthma and helps target therapy, but there is room for improvement in our accuracy in prediction of treatment responses and a need for better understanding of the underlying mechanisms. OBJECTIVE: We sought to identify molecular subphenotypes of asthma defined by proteomic signatures for improved stratification. METHODS: Unbiased label-free quantitative mass spectrometry and topological data analysis were used to analyze the proteomes of sputum supernatants from 246 participants (206 asthmatic patients) as a novel means of asthma stratification. Microarray analysis of sputum cells provided transcriptomics data additionally to inform on underlying mechanisms. RESULTS: Analysis of the sputum proteome resulted in 10 clusters (ie, proteotypes) based on similarity in proteomic features, representing discrete molecular subphenotypes of asthma. Overlaying granulocyte counts onto the 10 clusters as metadata further defined 3 of these as highly eosinophilic, 3 as highly neutrophilic, and 2 as highly atopic with relatively low granulocytic inflammation. For each of these 3 phenotypes, logistic regression analysis identified candidate protein biomarkers, and matched transcriptomic data pointed to differentially activated underlying mechanisms. CONCLUSION: This study provides further stratification of asthma currently classified based on quantification of granulocytic inflammation and provided additional insight into their underlying mechanisms, which could become targets for novel therapies.

20.
J Allergy Clin Immunol ; 144(5): 1198-1213, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30998987

RESUMO

BACKGROUND: The role of IL-17 immunity is well established in patients with inflammatory diseases, such as psoriasis and inflammatory bowel disease, but not in asthmatic patients, in whom further study is required. OBJECTIVE: We sought to undertake a deep phenotyping study of asthmatic patients with upregulated IL-17 immunity. METHODS: Whole-genome transcriptomic analysis was performed by using epithelial brushings, bronchial biopsy specimens (91 asthmatic patients and 46 healthy control subjects), and whole blood samples (n = 498) from the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) cohort. Gene signatures induced in vitro by IL-17 and IL-13 in bronchial epithelial cells were used to identify patients with IL-17-high and IL-13-high asthma phenotypes. RESULTS: Twenty-two of 91 patients were identified with IL-17, and 9 patients were identified with IL-13 gene signatures. The patients with IL-17-high asthma were characterized by risk of frequent exacerbations, airway (sputum and mucosal) neutrophilia, decreased lung microbiota diversity, and urinary biomarker evidence of activation of the thromboxane B2 pathway. In pathway analysis the differentially expressed genes in patients with IL-17-high asthma were shared with those reported as altered in psoriasis lesions and included genes regulating epithelial barrier function and defense mechanisms, such as IL1B, IL6, IL8, and ß-defensin. CONCLUSION: The IL-17-high asthma phenotype, characterized by bronchial epithelial dysfunction and upregulated antimicrobial and inflammatory response, resembles the immunophenotype of psoriasis, including activation of the thromboxane B2 pathway, which should be considered a biomarker for this phenotype in further studies, including clinical trials targeting IL-17.

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