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BACKGROUND: Patients with severe asthma show an increase in both exacerbation frequency and bronchial smooth muscle (BSM) mass. Rhinovirus (RV) infection of the bronchial epithelium (BE) is the main trigger of asthma exacerbations. Histological analysis of biopsies shows that a close connection between BE and hypertrophic BSM is a criterion for severity of asthma. OBJECTIVE: We hypothesized that RV infection of BE specifically increases BSM-cell migration from patients with asthma. METHODS: Serum samples, biopsies, or BSM cells were obtained from 86 patients with severe asthma and 31 subjects without asthma. BE cells from subjects without asthma were cultured in an air-liquid interface and exposed to RV-16. Migration of BSM cells was assessed in response to BE supernatant using chemotaxis assays. Chemokine concentrations were analyzed by transcriptomics and ELISAs. Immunocytochemistry, western blotting, and flow cytometry were used to quantify CXCR3 isoform distribution. CXCR3 downstream signaling pathways were assessed by calcium imaging and western blots. RESULTS: BSM cells from patients with severe asthma specifically migrated toward RV-infected BE, whereas those from subjects without asthma did not. This specific migration is driven by BE C-X-C motif chemokine ligand 10, which was increased in vitro in response to RV infection as well as in vivo in serum from exacerbating patients with severe asthma. The mechanism is related to both decreased expression and activation of the CXCR3-B-specific isoform in BSM cells from those with severe asthma. CONCLUSIONS: We have demonstrated a novel mechanism of BSM remodeling in patients with severe asthma following RV exacerbation. This study highlights the C-X-C motif chemokine ligand 10/CXCR3-A axis as a potential therapeutic target in severe asthma.
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Asma , Infecciones por Enterovirus , Asma/tratamiento farmacológico , Movimiento Celular , Infecciones por Enterovirus/metabolismo , Epitelio/patología , Humanos , Ligandos , Miocitos del Músculo Liso/metabolismo , RhinovirusRESUMEN
BACKGROUND: The links between microbial environmental exposures and asthma are well documented, but no study has combined deep sequencing results from pulmonary and indoor microbiomes of patients with asthma with spirometry, clinical, and endotype parameters. OBJECTIVE: The goal of this study was to investigate the links between indoor microbial exposures and pulmonary microbial communities and to document the role of microbial exposures on inflammatory and clinical outcomes of patients with severe asthma (SA). METHODS: A total of 55 patients with SA from the national Cohort of Bronchial Obstruction and Asthma cohort were enrolled for analyzing their indoor microbial flora through the use of electrostatic dust collectors (EDCs). Among these patients, 22 were able to produce sputum during "stable" or pulmonary "exacerbation" periods and had complete pairs of EDC and sputum samples, both collected and analyzed. We used amplicon targeted metagenomics to compare microbial communities from EDC and sputum samples of patients according to type 2 (T2)-asthma endotypes. RESULTS: Compared with patients with T2-low SA, patients with T2-high SA exhibited an increase in bacterial α-diversity and a decrease in fungal α-diversity of their indoor microbial florae, the latter being significantly correlated with fraction of exhaled nitric oxide levels. The ß-diversity of the EDC mycobiome clustered significantly according to T2 endotypes. Moreover, the proportion of fungal taxa in common between the sputum and EDC samples was significantly higher when patients exhibited acute exacerbation. CONCLUSION: These results illustrated, for the first time, a potential association between the indoor mycobiome and clinical features of patients with SA, which should renew interest in deciphering the interactions between indoor environment, fungi, and host in asthma.
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Contaminación del Aire Interior/análisis , Asma/microbiología , Polvo/análisis , Microbiota , Adulto , Anciano , ADN Bacteriano/análisis , ADN de Hongos/análisis , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Microbiota/genética , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Esputo/microbiologíaRESUMEN
BACKGROUND: Bronchial smooth muscle (BSM) remodelling in asthma is related to an increased mitochondrial biogenesis and enhanced BSM cell proliferation in asthma. Since mitochondria produce the highest levels of cellular energy and fatty acid ß-oxidation is the most powerful way to produce ATP, we hypothesised that, in asthmatic BSM cells, energetic metabolism is shifted towards the ß-oxidation of fatty acids. OBJECTIVES: We aimed to characterise BSM cell metabolism in asthma both in vitro and ex vivo to identify a novel target for reducing BSM cell proliferation. METHODS: 21 asthmatic and 31 non-asthmatic patients were enrolled. We used metabolomic and proteomic approaches to study BSM cells. Oxidative stress, ATP synthesis, fatty acid endocytosis, metabolite production, metabolic capabilities, mitochondrial networks, cell proliferation and apoptosis were assessed on BSM cells. Fatty acid content was assessed in vivo using matrix-assisted laser desorption/ionisation spectrometry imaging. RESULTS: Asthmatic BSM cells were characterised by an increased rate of mitochondrial respiration with a stimulated ATP production and mitochondrial ß-oxidation. Fatty acid consumption was increased in asthmatic BSM both in vitro and ex vivo. Proteome remodelling of asthmatic BSM occurred via two canonical mitochondrial pathways. The levels of carnitine palmitoyl transferase (CPT)2 and low-density lipoprotein (LDL) receptor, which internalise fatty acids through mitochondrial and cell membranes, respectively, were both increased in asthmatic BSM cells. Blocking CPT2 or LDL receptor drastically and specifically reduced asthmatic BSM cell proliferation. CONCLUSION: This study demonstrates a metabolic switch towards mitochondrial ß-oxidation in asthmatic BSM and identifies fatty acid metabolism as a new key target to reduce BSM remodelling in asthma.
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Asma , Proteómica , Asma/metabolismo , Bronquios , Ácidos Grasos/metabolismo , Humanos , Músculo Liso , Oxidación-ReducciónRESUMEN
AIMS: Pictograms on medicine boxes warn of potential drug-related driving hazard; we studied their association with serious accidents. METHODS: Prospective study in emergency departments of the hospitals in Bordeaux and Périgueux (France), of drivers with serious (admitted at least 24 hours) or nonserious vehicular accidents. Minors, passengers, pedestrians or subjects incapable of answering an interview were excluded. Interviews ascertained driver and accident characteristics, use of drugs with or without pictograms, use of alcohol and abuse substances, sleepiness, distractions, and mind wandering at the time of the accident, RESULTS: Between 18 October 2016 and 26 December 2018, 1200 of the 6212 drivers admitted to the hospital emergency rooms, 741 nonserious, 459 serious, were interviewed. Serious accidents were associated with male sex (odds ratio 1.89, 95% confidence interval [1.36-2.64]), age above 60 years (3.64 [2.21-6.00]), driving on local roads (3.34 [2.34-4.76]), driving a motorcycle (3.39 [2.29-5.00]), having drunk alcohol within 6 hours (2.89 [1.85-4.51]) and using a drug with a pictogram during the 24 hours previous to the accident (1.57 [1.06-2.32]). From 207 police reports, 101 drivers were not responsible, and 106 were responsible, associated with age below 40 years, driving in overcast or rainy weather (2.62 [1.29-5.33]), on local roads (3.89 [1.90-7.95]), and use of at least 1 pictogram drug in the previous week (3.12 [1.31-7.41]). CONCLUSION: The known risks of alcohol and pictogram drugs, of riding motorcycles and using local roads were confirmed. As measured, behavioural sleepiness did not predict accidents.
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Accidentes de Tránsito , Conducción de Automóvil , Adulto , Estudios Transversales , Servicio de Urgencia en Hospital , Francia/epidemiología , Hospitales , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Dupilumab is a monoclonal anti-IL-4Rα antibody developed for the treatment of severe asthma (SA). An early access programme for dupilumab was opened in France in SA patients experiencing unacceptable steroids side-effects and/or life-threatening exacerbations. OBJECTIVE: To assess changes in asthma control between baseline and 12 months of treatment. METHODS: Multi-centre (n = 13) retrospective real-life cohort study. This study is registered on ClinicalTrials.gov (NCT04022447). RESULTS: Overall, 64 patients with SA (median age 51, interquartile range [44-61]; 53% females) received dupilumab as add-on therapy to maximal standard of care; and 76% were on oral daily steroids at baseline. After 12 months, median asthma control test score improved from 14 [7-16] to 22 [17-24] (P < .001); median forced expiratory volume in 1 seconds increased from 58% [47-75] to 68% [58-88] (P = .001); and daily prednisone dose was reduced from 20 [10-30] to 5 [0-7] mg/d (P < .001). Annual exacerbations decreased from 4 [2-7] to 1 [0-2] (P < .001). Hypereosinophilia ≥1500/mm3 was observed at least once during follow-up in 16 patients (25%), persisting after 6 months in 8 (14%) of them. Increase in blood eosinophil count did not modify the clinical response during the study period. Injection-site reaction was the most common side effect (14%). Three deaths were observed, none related to treatment by investigators. CONCLUSION & CLINICAL RELEVANCE: In this first real-life cohort study of predominantly steroid-dependent SA, dupilumab significantly improved asthma control and lung function and reduced oral steroids use and exacerbations rate. Despite limitations due to the retrospective study, these results are consistent with controlled trials efficacy data. Further studies are required to assess the clinical significance and long-term prognosis of sustained dupilumab-induced hypereosinophilia.
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Anticuerpos Monoclonales Humanizados/administración & dosificación , Asma/tratamiento farmacológico , Índice de Severidad de la Enfermedad , Adulto , Anticuerpos Monoclonales Humanizados/efectos adversos , Asma/sangre , Asma/fisiopatología , Femenino , Estudios de Seguimiento , Francia , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosAsunto(s)
Asma , Biomarcadores , Índice de Severidad de la Enfermedad , Humanos , Asma/diagnóstico , Biomarcadores/sangreRESUMEN
Background The validity of three-dimensional (3D) ultrashort echo time (UTE) MRI for the assessment of emphysema in patients with chronic obstructive pulmonary disease (COPD) at high spatial resolution is, to the knowledge of the authors, unknown. Purpose To assess whether noncontrast agent-enhanced 3D UTE MRI at submillimeter spatial resolution can be used to determine the extent of emphysema by using both qualitative visual scoring and fully automated volumetric quantification. Materials and Methods Twenty-eight participants with COPD and 10 control participants (mean age, 70 years ± 7 [standard deviation] and 64 years ± 4, respectively) were prospectively enrolled between 2015 and 2017. Participants underwent pulmonary function testing, CT, and MRI. CT was used as the reference standard. Qualitative scoring of emphysema extent was performed by two readers. Fully automated quantification of percentage of low-attenuation volume by using a threshold of -950 HU (%LAV-950HU) at CT and percentage of low-signal-intensity volume by using an adaptive threshold of 0.20 (%LSV0.20) at MRI were the respective emphysema indexes. Comparison of means was performed by using Student t test, correlation was determined by using Pearson test, agreement was found by using weighted κ index, and reproducibility was determined by using intraclass correlation coefficient. Diagnostic performance was assessed by calculating the area under the receiver operating characteristics curve (AUC). Results With qualitative scoring, agreement between UTE MRI and CT was good (weighted κ, 0.79; 95% confidence interval: 0.71, 0.83). With automated volumetric quantification, %LSV0.20 was significantly correlated with %LAV-950HU in participants with COPD (r, -0.80; P < .001) and correlated with forced expiratory volume in 1 second percentage predicted (r, -0.55; P = .002). %LSV0.20 was significantly higher in participants with COPD than in control participants (P < .001). The diagnostic performance and reproducibility of %LSV0.20 were good (AUC, 1.00 [95% confidence interval: 0.88, 1.00], and intraclass correlation coefficient, > 0.99, respectively). Conclusion A fully automated method with three-dimensional ultrashort echo time MRI reproducibly quantified the volumetric extent of emphysema in participants with chronic obstructive pulmonary disease. © RSNA, 2019 Online supplemental material is available for this article.
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Imagen por Resonancia Magnética/métodos , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfisema Pulmonar/complicaciones , Enfisema Pulmonar/diagnóstico por imagen , Anciano , Femenino , Humanos , Imagenología Tridimensional/métodos , Pulmón/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los Resultados , Índice de Severidad de la EnfermedadRESUMEN
The remodelling mechanism and cellular players causing persistent airflow limitation in COPD remain largely elusive. We have recently demonstrated that circulating fibrocytes, a rare population of fibroblast-like cells produced by the bone marrow stroma, are increased in COPD patients during an exacerbation. We aimed to quantify fibrocyte density in situ in bronchial specimens from both control subjects and COPD patients, to define associations with relevant clinical, functional and computed tomography (CT) parameters, and to investigate the effect of the epithelial microenvironment on fibrocyte survival in vitro ("Fibrochir" study).A total of 17 COPD patients and 25 control subjects, all requiring thoracic surgery, were recruited. Using co-immunostaining and image analysis, we identified CD45+ FSP1+ cells as tissue fibrocytes, and quantified their density in distal and proximal bronchial specimens. Fibrocytes, cultured from the blood samples of six COPD patients, were exposed to primary bronchial epithelial cell secretions from control subjects or COPD patients.We demonstrate that fibrocytes are increased in both distal and proximal tissue specimens of COPD patients. The density of fibrocytes is negatively correlated with lung function parameters and positively correlated with bronchial wall thickness as assessed by CT scan. A high density of distal bronchial fibrocytes predicts the presence of COPD with a sensitivity of 83% and a specificity of 70%. Exposure of fibrocytes to COPD epithelial cell supernatant favours cell survival.Our results thus demonstrate an increased density of fibrocytes within the bronchi of COPD patients, which may be promoted by epithelial-derived survival-mediating factors.
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Biomarcadores/sangre , Bronquios/patología , Fibroblastos/citología , Enfermedad Pulmonar Obstructiva Crónica/patología , Anciano , Bronquios/diagnóstico por imagen , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/sangre , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: The Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study profiled patients with mild, moderate, and severe asthma and nonatopic healthy control subjects. OBJECTIVE: We explored this data set to define type 2 inflammation based on airway mucosal IL-13-driven gene expression and how this related to clinically accessible biomarkers. METHODS: IL-13-driven gene expression was evaluated in several human cell lines. We then defined type 2 status in 25 healthy subjects, 28 patients with mild asthma, 29 patients with moderate asthma, and 26 patients with severe asthma based on airway mucosal expression of (1) CCL26 (the most differentially expressed gene), (2) periostin, or (3) a multigene IL-13 in vitro signature (IVS). Clinically accessible biomarkers included fraction of exhaled nitric oxide (Feno) values, blood eosinophil (bEOS) counts, serum CCL26 expression, and serum CCL17 expression. RESULTS: Expression of airway mucosal CCL26, periostin, and IL-13-IVS all facilitated segregation of subjects into type 2-high and type 2-low asthmatic groups, but in the ADEPT study population CCL26 expression was optimal. All subjects with high airway mucosal CCL26 expression and moderate-to-severe asthma had Feno values (≥35 ppb) and/or high bEOS counts (≥300 cells/mm3) compared with a minority (36%) of subjects with low airway mucosal CCL26 expression. A combination of Feno values, bEOS counts, and serum CCL17 and CCL26 expression had 100% positive predictive value and 87% negative predictive value for airway mucosal CCL26-high status. Clinical variables did not differ between subjects with type 2-high and type 2-low status. Eosinophilic inflammation was associated with but not limited to airway mucosal type 2 gene expression. CONCLUSION: A panel of clinical biomarkers accurately classified type 2 status based on airway mucosal CCL26, periostin, or IL-13-IVS gene expression. Use of Feno values, bEOS counts, and serum marker levels (eg, CCL26 and CCL17) in combination might allow patient selection for novel type 2 therapeutics.
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Asma/sangre , Quimiocina CCL17/sangre , Quimiocinas CC/sangre , Adolescente , Adulto , Asma/inmunología , Asma/metabolismo , Asma/fisiopatología , Biomarcadores/sangre , Biomarcadores/metabolismo , Moléculas de Adhesión Celular/inmunología , Línea Celular , Quimiocina CCL17/inmunología , Quimiocina CCL26 , Quimiocinas CC/inmunología , Eosinófilos/inmunología , Femenino , Expresión Génica , Humanos , Interleucina-13/genética , Interleucina-13/inmunología , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Óxido Nítrico/metabolismo , Pruebas de Función Respiratoria , Mucosa Respiratoria/inmunología , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
Acute exacerbations of chronic obstructive pulmonary disease (COPD) can be prevented by inhaled treatment. Errors in inhaler handling, not taken into account in clinical trials, could impact drug delivery and minimise treatment benefit. We aimed to assess real-life inhaler device handling in COPD patients and its association with COPD exacerbations.To this end, 212 general practitioners and 50 pulmonologists assessed the handling of 3393 devices used for continuous treatment of COPD in 2935 patients. Handling errors were observed in over 50% of handlings, regardless of the device used. Critical errors compromising drug delivery were respectively made in 15.4%, 21.2%, 29.3%, 43.8%, 46.9% and 32.1% of inhalation assessment tests with Breezhaler® (n=876), Diskus® (n=452), Handihaler® (n=598), pressurised metered-dose inhaler (pMDI) (n=422), Respimat® (n=625) and Turbuhaler® (n=420).The proportion of patients requiring hospitalisation or emergency room visits in the past 3â months for severe COPD exacerbation was 3.3% (95% CI 2.0-4.5) in the absence of error and 6.9% (95% CI 5.3-8.5) in the presence of critical error (OR 1.86, 95% CI 1.14-3.04, p<0.05).Handling errors of inhaler devices are underestimated in real life and are associated with an increased rate of severe COPD exacerbation. Training in inhaler use is an integral part of COPD management.
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Broncodilatadores/administración & dosificación , Inhaladores de Dosis Medida , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Bromuro de Tiotropio/administración & dosificación , Administración por Inhalación , Adulto , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Diseño de Equipo , Femenino , Francia , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Encuestas y CuestionariosRESUMEN
RATIONALE: Increased bronchial smooth muscle (BSM) mass is a key feature of airway remodeling that classically distinguishes severe from nonsevere asthma. Proliferation of BSM cells involves a specific mitochondria-dependent pathway in individuals with severe asthma. However, BSM remodeling and mitochondrial biogenesis have not been examined in nonsevere asthma. OBJECTIVES: We aimed to assess whether an increase in BSM mass was also implicated in nonsevere asthma and its relationship with mitochondria and clinical outcomes. METHODS: We enrolled 34 never-smoker subjects with nonsevere asthma. In addition, we recruited 56 subjects with nonsevere asthma and 19 subjects with severe asthma as comparative groups (COBRA cohort [Cohorte Obstruction Bronchique et Asthme; Bronchial Obstruction and Asthma Cohort; sponsored by the French National Institute of Health and Medical Research, INSERM]). A phenotypic characterization was performed using questionnaires, atopy and pulmonary function testing, exhaled nitric oxide measurement, and blood collection. Bronchial biopsy specimens were processed for immunohistochemistry and electron microscopy analysis. After BSM remodeling assessment, subjects were monitored over a 12-month period. MEASUREMENTS AND MAIN RESULTS: We identified characteristic features of remodeling (BSM area >26.6%) and increased mitochondrial number within BSM in a subgroup of subjects with nonsevere asthma. The number of BSM mitochondria was positively correlated with BSM area (r = 0.78; P < 0.001). Follow-up analysis showed that subjects with asthma with high BSM had worse asthma control and a higher rate of exacerbations per year compared with subjects with low BSM. CONCLUSIONS: This study reveals that BSM remodeling and mitochondrial biogenesis may play a critical role in the natural history of nonsevere asthma (Mitasthme study). Clinical trial registered with www.clinicaltrials.gov (NCT00808730).
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Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Asma/fisiopatología , Bronquios/fisiopatología , Músculo Liso/fisiopatología , Adulto , Broncoscopía , Femenino , Humanos , Masculino , Microscopía Electrónica , Miocitos del Músculo Liso/fisiologíaRESUMEN
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by peribronchial fibrosis. The chronic course of COPD is worsened by recurrent acute exacerbations. OBJECTIVE: The aim of the study was to evaluate the recruitment of blood fibrocytes in patients with COPD during exacerbations and, subsequently, to identify potential mechanisms implicated in such recruitment. METHODS: Using flow cytometry, we quantified circulating fibrocytes and characterized their chemokine receptor expression in 54 patients with COPD examined during an acute exacerbation (V1) and 2 months afterward (V2) and in 40 control subjects. The role of the chemokines CXCL12 and CCL11 in fibrocyte migration was investigated by using a chemotaxis assay. Patients were followed for up to 3 years after V1. RESULTS: We demonstrated a significantly increased number of circulating fibrocytes at V1 compared with control subjects. The number of circulating fibrocytes decreased at V2. A high percentage of circulating fibrocytes during exacerbation was associated with increased risk of death. The percentage of fibrocytes at V2 was negatively correlated with FEV1, forced vital capacity, FEV1/forced vital capacity ratio, transfer lung capacity of carbon monoxide, and Pao2. Fibrocytes highly expressed CXCR4 and CCR3, the chemokine receptors for CXCL12 and CCL11, respectively. Fibrocytes collected from patients with COPD at V1 had increased chemotactic migration in response to CXCL12 but not to CCL11 compared with those from control subjects. Plerixafor, a CXCR4 antagonist, decreased fibrocyte migration to plasma from patients with exacerbating COPD. CONCLUSION: Blood fibrocytes are recruited during COPD exacerbations and related to mortality and low lung function. The CXCL12/CXCR4 axis is involved in such fibrocyte recruitment (Firebrob study; ClinicalTrials NCT01196832).
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Quimiocina CXCL12/sangre , Fibroblastos/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Receptores CXCR4/sangre , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Casos y Controles , Quimiocina CCL11/sangre , Quimiotaxis , Progresión de la Enfermedad , Femenino , Fibroblastos/fisiología , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/sangre , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Receptores CCR3/sangreRESUMEN
BACKGROUND: Increase of bronchial smooth muscle (BSM) mass is a crucial feature of asthma remodeling. The mechanisms of such an increased BSM mass are complex but involve enhanced mitochondrial biogenesis, leading to increased proliferation of BSM cells in asthmatic patients. The major tumor suppressor protein p53 is a key cell regulator involved in cell proliferation and has also been implicated in mitochondrial biogenesis. However, the role of p53 in BSM cell proliferation and mitochondrial biogenesis has not been investigated thus far. OBJECTIVE: We sought to evaluate the role of p53 in proliferation of BSM cells in asthmatic patients and mitochondrial biogenesis. METHODS: The expression of p53 was assessed both in vitro by using flow cytometry and Western blotting and ex vivo by using RT-PCR after laser microdissection. The role of p53 was assessed with small hairpin RNA lentivirus in both asthmatic patients and control subjects with BSM cell proliferation by using 5-bromo-2'-deoxyuridine and cell counting and in the expression of p21, BCL2-associated X protein, mitochondrial transcription factor A (TFAM), and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α). RESULTS: Twenty-nine patients with moderate-to-severe asthma and 26 control subjects were enrolled in the study. p53 expression was increased in BSM from asthmatic patients both ex vivo and in vitro, with a decreased interaction with mouse double minute 2 homolog (Mdm2) and an increased phosphorylation of serine 20. p53 did not inhibit the transcription of both TFAM and PGC-1α in BSM cells from asthmatic patients. As a consequence, p53 is unable to slow the increased mitochondrial biogenesis and hence the subsequent increased proliferation of BSM cells in asthmatic patients. CONCLUSION: This study suggests that p53 might act as a new potential therapeutic target against BSM remodeling in asthmatic patients.
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Asma/metabolismo , Bronquios/metabolismo , Músculo Liso/metabolismo , Biogénesis de Organelos , Proteína p53 Supresora de Tumor/metabolismo , Adulto , Anciano , Antiasmáticos/uso terapéutico , Asma/diagnóstico , Asma/tratamiento farmacológico , Estudios de Casos y Controles , Proliferación Celular , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Factores de Riesgo , Proteína p53 Supresora de Tumor/genéticaRESUMEN
The immune responses of type 2 T helper cells (Th2) play an important role in asthma and promote the differentiation of alternatively activated (M2) macrophages. M2 macrophages have been increasingly understood to contribute to Th2 immunity. We hypothesized that M2 macrophages are altered in asthma and modulate Th2 responses. The aim of this study was to characterize the phenotype and function of human monocyte-derived M2 and bronchoalveolar lavage fluid (BALF) macrophages from healthy control subjects and subjects with asthma. Phenotypic characteristics and effector function of M2 macrophages were examined using monocyte-derived and BALF macrophages obtained from subjects with asthma (n = 28) and healthy volunteers (n = 9) by flow cytometry and quantitative PCR. Resting monocyte-derived (M0) and M2 macrophages were generated by the addition of macrophage colony-stimulating factor or macrophage colony-stimulating factor plus IL-4, respectively. M2 macrophage cytokine expression and their impact on dendritic and CD4+ T cell activation were examined in vitro. High levels of CD206 and major histocompatibility complex class II expression identify macrophages with an M2 phenotype that are increased 2.9-fold in the BALF of subjects with asthma compared with control subjects. M2 macrophages have elevated IL-6, IL-10, and IL-12p40 production compared with conventional macrophages and modulate dendritic and CD4+ T cell interactions. Histamine receptor 1 and E-cadherin expression identify M2 macrophage subsets associated with increased airflow obstruction. M2 macrophages have a distinct cell surface and effector phenotype and are found in increased numbers in subjects with asthma. These findings suggest that M2 macrophages may play an important role in allergic asthma through their bidirectional interactions with immune and structural cells, and inflammatory mediators.
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RATIONALE: Severe pulmonary hypertension (PH) is very uncommon in COPD, and a distinct phenotype has been hypothesised. We aimed to evaluate whether CT can help to recognise this condition non-invasively by measuring small pulmonary vessels. MATERIAL AND METHODS: Patients with COPD who underwent pulmonary function tests, unenhanced CT of the chest and right heart catheterisation (RHC) during a period of stability were included in the study. From 105 included patients, 20 patients with COPD with severe PH (mean pulmonary arterial pressure, mPAP>35â mmâ Hg) were compared with 20 FEV1-matched and age-matched patients with COPD with mild or without PH (mPAP<35â mmâ Hg). The percentage of total cross-sectional area of vessels less than 5â mm(2) normalised by lung area (%CSA<5) and 5-10â mm(2) (%CSA5-10), the mean number of cross-sectioned vessels (CSNs) and bronchial wall thickness (WT) were measured on CT examination and compared between groups. Paw scores combining PaO2 measurement and CT parameters best correlated with mPAP were compared by receiver operating characteristic analysis to predict severe PH in COPD. RESULTS: Patients with severe PH COPD had higher %CSA and CSN values than those of patients with COPD without severe PH. Using multiple regression analysis, %CSA<5 and WT were the best predictors of mPAP in patients with and without severe PH, respectively. A score combining %CSA<5, PaO2 and WT best predicted severe PH in patients with COPD. CONCLUSIONS: CT measurements of small vessels support a distinct vessel-related phenotype in patients with COPD with severe PH, and combined with WT and PaO2 parameters in the paw score, which may offer a non-invasive tool to select patients for RHC.
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Presión Arterial/fisiología , Hipertensión Pulmonar/etiología , Arteria Pulmonar/diagnóstico por imagen , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Venas Pulmonares/diagnóstico por imagen , Anciano , Cateterismo Cardíaco , Femenino , Humanos , Hipertensión Pulmonar/diagnóstico por imagen , Hipertensión Pulmonar/fisiopatología , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Presión Parcial , Fenotipo , Arteria Pulmonar/patología , Arteria Pulmonar/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico por imagen , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Venas Pulmonares/patología , Curva ROC , Pruebas de Función Respiratoria , Factores de Riesgo , Tomografía Computarizada por Rayos X/métodosRESUMEN
RATIONALE: Asthma is a frequent airway disease, and asthma control determinants have been associated with indoor allergen sensitization. The most frequent allergens are house dust mites (HDM), which act in vivo on the bronchial epithelial layer. Severe asthma has also been associated with bronchial remodeling and more specifically with increased mass of bronchial smooth muscle (BSM). However, the relationship between HDM stimulation of the bronchial epithelial layer and BSM remodeling is unknown. OBJECTIVES: To evaluate whether epithelial stimulation with HDM induces BSM cell proliferation in subjects with severe asthma. METHODS: A total of 22 subjects with severe asthma and 27 subjects with no asthma were recruited. We have developed an in vitro culture model combining an epithelium layer in air-liquid interface (ALI) interacting with BSM. We assessed BSM proliferation using BrdU incorporation. We explored the role of epithelium-derived mediators using reverse-transcriptase polymerase chain reaction (RT-PCR) and ELISA in vitro and in vivo. Finally, leukotrienes receptor expression was assessed in vitro by flow cytometry and RT-PCR and ex vivo by laser microdissection and RT-PCR. MEASUREMENTS AND MAIN RESULTS: We found that epithelial stimulation by HDM selectively increased the proliferation of asthmatic BSM cells and not that of nonasthmatic cells. The mechanism involved epithelial protease-activated receptor-2-dependent production of leukotrienes C4 associated with an overexpression of leukotrienes receptor CysLTR1 by asthmatic BSM cells in vitro and ex vivo. CONCLUSIONS: This work demonstrates the selective role of HDM on BSM remodeling in patients with severe asthma and points out different therapeutic targets at epithelial and smooth muscle levels.
Asunto(s)
Asma/fisiopatología , Pyroglyphidae/inmunología , Adulto , Anciano , Animales , Asma/inmunología , Técnicas de Cultivo de Célula , Proliferación Celular/fisiología , Epitelio/fisiología , Femenino , Humanos , Leucotrieno C4/metabolismo , Masculino , Ratones Endogámicos BALB C , Persona de Mediana Edad , Receptores de Leucotrienos/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto JovenRESUMEN
RATIONALE: Severe asthma is a major public health issue throughout the world. Increased bronchial smooth muscle (BSM) mass, a characteristic feature of airway remodeling in severe asthma, is associated with resistance to high-intensity treatment and poor prognosis. In vitro, the Ca(2+)-channel blocker gallopamil decreased the proliferation of BSM cells from patients with severe asthma. OBJECTIVES: We conducted a double-blind, randomized, placebo-controlled study to evaluate the effect of gallopamil on airway remodeling in patients with severe asthma. METHODS: Subjects received either gallopamil (n = 16) or placebo (n = 15) for 1 year and were monitored for an additional 3-month period. Airway remodeling was analyzed at baseline and after treatment phase using both fiberoptic bronchoscopy and computed tomography scan. The primary end point was the BSM area. Secondary end points included normalized BSM thickness and frequency of asthma exacerbations. MEASUREMENTS AND MAIN RESULTS: BSM area was reduced in the gallopamil group (baseline vs. end of treatment) but was unchanged in the placebo group. Between-group differences in BSM area were not significantly different in gallopamil versus placebo groups. By contrast, between-group differences in normalized BSM thickness were significantly different between the two groups. The mean number of exacerbations per month was not different during the treatment phase in gallopamil versus placebo group but was significantly lower in patients previously treated with gallopamil during the follow-up period. There were no differences between the groups with respect to overall side effects. CONCLUSIONS: Gallopamil treatment for 12 months reduces BSM remodeling and prevents the occurrence of asthma exacerbations. Clinical trial registered with www.clinicaltrials.gov (NCT 00896428).