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Lung inflammation, caused by acute exposure to ozone (O3), one of the six criteria air pollutants, is a significant source of morbidity in susceptible individuals. Alveolar macrophages (AMØs) are the most abundant immune cells in the normal lung, and their number increases after O3 exposure. However, the role of AMØs in promoting or limiting O3-induced lung inflammation has not been clearly defined. In this study, we used a mouse model of acute O3 exposure, lineage tracing, genetic knockouts, and data from O3-exposed human volunteers to define the role and ontogeny of AMØs during acute O3 exposure. Lineage-tracing experiments showed that 12, 24, and 72 hours after exposure to O3 (2 ppm) for 3 hours, all AMØs were of tissue-resident origin. Similarly, in humans exposed to filtered air and O3 (200 ppb) for 135 minutes, we did not observe at â¼21 hours postexposure an increase in monocyte-derived AMØs by flow cytometry. Highlighting a role for tissue-resident AMØs, we demonstrate that depletion of tissue-resident AMØs with clodronate-loaded liposomes led to persistence of neutrophils in the alveolar space after O3 exposure, suggesting that impaired neutrophil clearance (i.e., efferocytosis) leads to prolonged lung inflammation. Moreover, depletion of tissue-resident AMØs demonstrated reduced clearance of intratracheally instilled apoptotic Jurkat cells, consistent with reduced efferocytosis. Genetic ablation of MerTK (MER proto-oncogene, tyrosine kinase), a key receptor involved in efferocytosis, also resulted in impaired clearance of apoptotic neutrophils after O3 exposure. Overall, these findings underscore the pivotal role of tissue-resident AMØs in resolving O3-induced inflammation via MerTK-mediated efferocytosis.
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Macrófagos Alveolares , Ozono , Fagocitosis , Proto-Oncogenes Mas , Tirosina Quinasa c-Mer , Ozono/farmacología , Tirosina Quinasa c-Mer/metabolismo , Tirosina Quinasa c-Mer/genética , Animales , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/efectos de los fármacos , Humanos , Fagocitosis/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Neumonía/metabolismo , Neumonía/inducido químicamente , Neumonía/patología , Ratones Noqueados , Masculino , Inflamación/metabolismo , Inflamación/patología , Inflamación/inducido químicamente , Apoptosis/efectos de los fármacos , Pulmón/patología , Pulmón/metabolismo , Pulmón/efectos de los fármacos , EferocitosisRESUMEN
BACKGROUND: Long COVID impacts â¼10% of people diagnosed with COVID-19, yet the pathophysiology driving ongoing symptoms is poorly understood. We hypothesised that 129Xe magnetic resonance imaging (MRI) could identify unique pulmonary phenotypic subgroups of long COVID, therefore we evaluated ventilation and gas exchange measurements with cluster analysis to generate imaging-based phenotypes. METHODS: COVID-negative controls and participants who previously tested positive for COVID-19 underwent 129XeMRI â¼14-months post-acute infection across three centres. Long COVID was defined as persistent dyspnea, chest tightness, cough, fatigue, nausea and/or loss of taste/smell at MRI; participants reporting no symptoms were considered fully-recovered. 129XeMRI ventilation defect percent (VDP) and membrane (Mem)/Gas, red blood cell (RBC)/Mem and RBC/Gas ratios were used in k-means clustering for long COVID, and measurements were compared using ANOVA with post-hoc Bonferroni correction. RESULTS: We evaluated 135 participants across three centres: 28 COVID-negative (40±16yrs), 34 fully-recovered (42±14yrs) and 73 long COVID (49±13yrs). RBC/Mem (p=0.03) and FEV1 (p=0.04) were different between long- and COVID-negative; FEV1 and all other pulmonary function tests (PFTs) were within normal ranges. Four unique long COVID clusters were identified compared with recovered and COVID-negative. Cluster1 was the youngest with normal MRI and mild gas-trapping; Cluster2 was the oldest, characterised by reduced RBC/Mem but normal PFTs; Cluster3 had mildly increased Mem/Gas with normal PFTs; and Cluster4 had markedly increased Mem/Gas with concomitant reduction in RBC/Mem and restrictive PFT pattern. CONCLUSION: We identified four 129XeMRI long COVID phenotypes with distinct characteristics. 129XeMRI can dissect pathophysiologic heterogeneity of long COVID to enable personalised patient care.
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BACKGROUND: Severe COVID-19 carries a high morbidity and mortality. Previous studies have shown an association between COVID-19 severity and SARS-CoV-2 viral load (VL). We sought to measure VL in multiple compartments (urine, plasma, lower respiratory tract) in patients admitted to the intensive care unit (ICU) with severe COVID-19 pneumonia and correlate with clinical outcomes. METHODS: Plasma, urine, and endotracheal aspirate (ETA) samples were obtained on days 1, 3, 7, 14, and 21 from subjects admitted to the ICU with severe COVID-19. VL was measured via reverse transcriptase polymerase chain reaction. Clinical data was collected from the electronic health record. Grouped comparisons were performed using Student's t-test or 1-way ANOVA. Linear regression was used to correlate VL from different compartments collected at the same time. Logistic regression was performed to model ventilator-freedom at 28 days as a function of peak plasma VL. RESULTS: We enrolled 57 subjects with severe COVID-19 and measured VL in plasma (n = 57), urine (n = 25), and ETA (n = 34). Ventilator-associated pneumonia developed in 63% of subjects. 49% of subjects were viremic on study day 1. VL in plasma and ETA both significantly decreased by day 14 (P < 0.05), and the two were weakly correlated on study day 1 (P = 0.0037, r2 = 0.2343) and on all study days (P < 0.001, r2 = 0.2211). VL were not detected in urine. While no associations were observed with peak ETA VL, subjects with higher peak plasma VL experienced a greater number of respiratory complications, including ventilator-associated pneumonia and fewer ventilator-free and hospital-free days. There was no association between VL in either plasma or ETA and mortality. In viremic patients, plasma VL was significantly lower in subjects that were ICU-free and ventilator-free (P < 0.05), with trends noted for hospital-freedom, ventilator-associated pneumonia, and survival to discharge (P < 0.1). By logistic regression, plasma VL was inversely associated with ventilator-freedom at 28 days (odds ratio 0.14, 95% confidence interval 0.02-0.50). CONCLUSIONS: Elevated SARS-CoV-2 VL in the plasma but not in the lower respiratory tract is a novel biomarker in severe COVID-19 for respiratory complications.
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COVID-19 , Unidades de Cuidados Intensivos , SARS-CoV-2 , Carga Viral , Viremia , Humanos , COVID-19/complicaciones , Masculino , Femenino , Persona de Mediana Edad , Anciano , Índice de Severidad de la Enfermedad , Neumonía Asociada al Ventilador/epidemiología , Neumonía Asociada al Ventilador/virología , AdultoRESUMEN
Rationale: There are no pharmacologic agents that modify emphysema progression in patients with chronic obstructive pulmonary disease (COPD). Objectives: To evaluate the efficacy of losartan, an angiotensin receptor blocker, to reduce emphysema progression. Methods: The trial was a multicenter, randomized, placebo-controlled trial conducted between May 2017 and January 2021. Eligible participants were aged ⩾40 years, had moderate to severe airflow obstruction, ⩾10 pack-years of smoking, mild-moderate emphysema on high-resolution computed tomography, and no medical indication for or intolerance of angiotensin receptor blockers. Treatment with losartan 100 mg daily or matching placebo (1:1) was randomly assigned. The primary outcome was emphysema progression on high-resolution computed tomography over 48 weeks. Secondary outcomes included the St George's Respiratory Questionnaire, the modified Medical Research Council dyspnea scale, the COPD Assessment Test, and the Physical Function-Short Form 20a. Measurements and Main Results: A total of 220 participants were enrolled; 58% were men, 19% were African American, and 24% were current smokers. The medians (interquartile ranges) for age were 65 (61-73) years and 48 (36-59) for percent predicted FEV1 after bronchodilator use. The mean (95% confidence interval) percentage emphysema progression was 1.35% (0.67-2.03) in the losartan group versus 0.66% (0.09-1.23) in the placebo group (P = NS). Conclusions: Losartan did not prevent emphysema progression in people with COPD with mild-moderate emphysema. Clinical trial registered with www.clinicaltrials.gov (NCT02696564).
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Enfisema , Enfermedad Pulmonar Obstructiva Crónica , Enfisema Pulmonar , Anciano , Antagonistas de Receptores de Angiotensina/uso terapéutico , Broncodilatadores/uso terapéutico , Progresión de la Enfermedad , Femenino , Volumen Espiratorio Forzado , Humanos , Losartán/uso terapéutico , Masculino , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfisema Pulmonar/complicaciones , Enfisema Pulmonar/tratamiento farmacológicoRESUMEN
BACKGROUND: In many patients with mild, persistent asthma, the percentage of eosinophils in sputum is less than 2% (low eosinophil level). The appropriate treatment for these patients is unknown. METHODS: In this 42-week, double-blind, crossover trial, we assigned 295 patients who were at least 12 years of age and who had mild, persistent asthma to receive mometasone (an inhaled glucocorticoid), tiotropium (a long-acting muscarinic antagonist), or placebo. The patients were categorized according to the sputum eosinophil level (<2% or ≥2%). The primary outcome was the response to mometasone as compared with placebo and to tiotropium as compared with placebo among patients with a low sputum eosinophil level who had a prespecified differential response to one of the trial agents. The response was determined according to a hierarchical composite outcome that incorporated treatment failure, asthma control days, and the forced expiratory volume in 1 second; a two-sided P value of less than 0.025 denoted statistical significance. A secondary outcome was a comparison of results in patients with a high sputum eosinophil level and those with a low level. RESULTS: A total of 73% of the patients had a low eosinophil level; of these patients, 59% had a differential response to a trial agent. However, there was no significant difference in the response to mometasone or tiotropium, as compared with placebo. Among the patients with a low eosinophil level who had a differential treatment response, 57% (95% confidence interval [CI], 48 to 66) had a better response to mometasone, and 43% (95% CI, 34 to 52) had a better response to placebo (P = 0.14). In contrast 60% (95% CI, 51 to 68) had a better response to tiotropium, whereas 40% (95% CI, 32 to 49) had a better response to placebo (P = 0.029). Among patients with a high eosinophil level, the response to mometasone was significantly better than the response to placebo (74% vs. 26%) but the response to tiotropium was not (57% vs. 43%). CONCLUSIONS: The majority of patients with mild, persistent asthma had a low sputum eosinophil level and had no significant difference in their response to either mometasone or tiotropium as compared with placebo. These data provide equipoise for a clinically directive trial to compare an inhaled glucocorticoid with other treatments in patients with a low eosinophil level. (Funded by the National Heart, Lung, and Blood Institute; SIENA ClinicalTrials.gov number, NCT02066298.).
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Asma/tratamiento farmacológico , Broncodilatadores/uso terapéutico , Eosinófilos , Glucocorticoides/uso terapéutico , Furoato de Mometasona/uso terapéutico , Esputo/inmunología , Bromuro de Tiotropio/uso terapéutico , Administración por Inhalación , Adolescente , Adulto , Asma/inmunología , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Recuento de Leucocitos , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Morbidity from asthma is disproportionately higher among black patients than among white patients, and black patients constitute the minority of participants in trials informing treatment. Data indicate that patients with inadequately controlled asthma benefit more from addition of a long-acting beta-agonist (LABA) than from increased glucocorticoids; however, these data may not be informative for treatment in black patients. METHODS: We conducted two prospective, randomized, double-blind trials: one involving children and the other involving adolescents and adults. In both trials, the patients had at least one grandparent who identified as black and had asthma that was inadequately controlled with low-dose inhaled glucocorticoids. We compared combinations of therapy, which included the addition of a LABA (salmeterol) to an inhaled glucocorticoid (fluticasone propionate), a step-up to double to quintuple the dose of fluticasone, or both. The treatments were compared with the use of a composite measure that evaluated asthma exacerbations, asthma-control days, and lung function; data were stratified according to genotypic African ancestry. RESULTS: When quintupling the dose of fluticasone (to 250 µg twice a day) was compared with adding salmeterol (50 µg twice a day) and doubling the fluticasone (to 100 µg twice a day), a superior response occurred in 46% of the children with quintupling the fluticasone and in 46% of the children with doubling the fluticasone and adding salmeterol (P = 0.99). In contrast, more adolescents and adults had a superior response to added salmeterol than to an increase in fluticasone (salmeterol-low-dose fluticasone vs. medium-dose fluticasone, 49% vs. 28% [P = 0.003]; salmeterol-medium-dose fluticasone vs. high-dose fluticasone, 49% vs. 31% [P = 0.02]). Neither the degree of African ancestry nor baseline biomarkers predicted a superior response to specific treatments. The increased dose of inhaled glucocorticoids was associated with a decrease in the ratio of urinary cortisol to creatinine in children younger than 8 years of age. CONCLUSIONS: In contrast to black adolescents and adults, almost half the black children with poorly controlled asthma had a superior response to an increase in the dose of an inhaled glucocorticoid and almost half had a superior response to the addition of a LABA. (Funded by the National Heart, Lung, and Blood Institute; BARD ClinicalTrials.gov number, NCT01967173.).
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Agonistas de Receptores Adrenérgicos beta 2/administración & dosificación , Asma/tratamiento farmacológico , Negro o Afroamericano , Broncodilatadores/administración & dosificación , Fluticasona/administración & dosificación , Glucocorticoides/administración & dosificación , Xinafoato de Salmeterol/administración & dosificación , Administración por Inhalación , Adolescente , Adulto , Niño , Preescolar , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Combinación de Medicamentos , Femenino , Humanos , Masculino , Estudios ProspectivosRESUMEN
BACKGROUND: Asthma patients with comorbid obesity exhibit increased disease severity, in part, due to airway remodeling, which is also observed in mouse models of asthma and obesity. A mediator of remodeling that is increased in obesity is leptin. We hypothesized that in a mouse model of allergic airways disease, mice receiving exogenous leptin would display increased airway inflammation and fibrosis. METHODS: Five-week-old male and female C57BL/6J mice were challenged with intranasal house dust mite (HDM) allergen or saline 5 days per week for 6 weeks (n = 6-9 per sex, per group). Following each HDM exposure, mice received subcutaneous recombinant human leptin or saline. At 48 h after the final HDM challenge, lung mechanics were evaluated and the mice were sacrificed. Bronchoalveolar lavage was performed and differential cell counts were determined. Lung tissue was stained with Masson's trichrome, periodic acid-Schiff, and hematoxylin and eosin stains. Mouse lung fibroblasts were cultured, and whole lung mRNA was isolated. RESULTS: Leptin did not affect mouse body weight, but HDM+leptin increased baseline blood glucose. In mixed-sex groups, leptin increased mouse lung fibroblast invasiveness and increased lung Col1a1 mRNA expression. Total lung resistance and tissue damping were increased with HDM+leptin treatment, but not leptin or HDM alone. Female mice exhibited enhanced airway responsiveness to methacholine with HDM+leptin treatment, while leptin alone decreased total respiratory system resistance in male mice. CONCLUSIONS: In HDM-induced allergic airways disease, administration of exogenous leptin to mice enhanced lung resistance and increased markers of fibrosis, with differing effects between males and females.
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Asma , Hipersensibilidad , Enfermedad Pulmonar Obstructiva Crónica , Fibrosis Pulmonar , Alérgenos , Animales , Asma/metabolismo , Biomarcadores/metabolismo , Líquido del Lavado Bronquioalveolar , Modelos Animales de Enfermedad , Femenino , Fibrosis , Humanos , Hipersensibilidad/metabolismo , Leptina , Pulmón/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Obesidad/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Fibrosis Pulmonar/metabolismo , Pyroglyphidae , ARN Mensajero/metabolismoRESUMEN
BACKGROUND: COVID-19 causes hypercoagulability, but the association between coagulopathy and hypoxemia in critically ill patients has not been thoroughly explored. This study hypothesized that severity of coagulopathy would be associated with acute respiratory distress syndrome severity, major thrombotic events, and mortality in patients requiring intensive care unit-level care. METHODS: Viscoelastic testing by rotational thromboelastometry and coagulation factor biomarker analyses were performed in this prospective observational cohort study of critically ill COVID-19 patients from April 2020 to October 2020. Statistical analyses were performed to identify significant coagulopathic biomarkers such as fibrinolysis-inhibiting plasminogen activator inhibitor 1 and their associations with clinical outcomes such as mortality, extracorporeal membrane oxygenation requirement, occurrence of major thrombotic events, and severity of hypoxemia (arterial partial pressure of oxygen/fraction of inspired oxygen categorized into mild, moderate, and severe per the Berlin criteria). RESULTS: In total, 53 of 55 (96%) of the cohort required mechanical ventilation and 9 of 55 (16%) required extracorporeal membrane oxygenation. Extracorporeal membrane oxygenation-naïve patients demonstrated lysis indices at 30 min indicative of fibrinolytic suppression on rotational thromboelastometry. Survivors demonstrated fewer procoagulate acute phase reactants, such as microparticle-bound tissue factor levels (odds ratio, 0.14 [0.02, 0.99]; P = 0.049). Those who did not experience significant bleeding events had smaller changes in ADAMTS13 levels compared to those who did (odds ratio, 0.05 [0, 0.7]; P = 0.026). Elevations in plasminogen activator inhibitor 1 (odds ratio, 1.95 [1.21, 3.14]; P = 0.006), d-dimer (odds ratio, 3.52 [0.99, 12.48]; P = 0.05), and factor VIII (no clot, 1.15 ± 0.28 vs. clot, 1.42 ± 0.31; P = 0.003) were also demonstrated in extracorporeal membrane oxygenation-naïve patients who experienced major thrombotic events. Plasminogen activator inhibitor 1 levels were significantly elevated during periods of severe compared to mild and moderate acute respiratory distress syndrome (severe, 44.2 ± 14.9 ng/ml vs. mild, 31.8 ± 14.7 ng/ml and moderate, 33.1 ± 15.9 ng/ml; P = 0.029 and 0.039, respectively). CONCLUSIONS: Increased inflammatory and procoagulant markers such as plasminogen activator inhibitor 1, microparticle-bound tissue factor, and von Willebrand factor levels are associated with severe hypoxemia and major thrombotic events, implicating fibrinolytic suppression in the microcirculatory system and subsequent micro- and macrovascular thrombosis in severe COVID-19.
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Trastornos de la Coagulación Sanguínea , COVID-19 , Síndrome de Dificultad Respiratoria , Trombofilia , Trombosis , Trastornos de la Coagulación Sanguínea/complicaciones , COVID-19/complicaciones , Enfermedad Crítica , Fibrinólisis , Humanos , Hipoxia/complicaciones , Microcirculación , Oxígeno , Inhibidor 1 de Activador Plasminogénico , Estudios Prospectivos , Estudios Retrospectivos , Trombofilia/complicaciones , TromboplastinaRESUMEN
Obesity is a major risk factor for the development of asthma, and the prevalence of obesity is higher in people with asthma than in the general population. Obese people often have severe asthma-recent studies in the United States suggest that 60% of adults with severe asthma are obese. Multiple mechanisms link obesity and asthma, which are discussed in this article, and these pathways contribute to different phenotypes of asthma among people with obesity. From a practical aspect, changes in physiology and immune markers affect diagnosis and monitoring of disease activity in people with asthma and obesity. Obesity also affects response to asthma medications and is associated with an increased risk of co-morbidities such as gastroesophageal reflux disease, depression, and obstructive sleep apnea, all of which may affect asthma control. Obese people may be at elevated risk of exacerbations related to increased risk of severe disease in response to viral infections. Interventions that target improved dietary quality, exercise, and weight loss are likely to be particularly helpful for this patient population.
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Asma , Apnea Obstructiva del Sueño , Asma/tratamiento farmacológico , Asma/epidemiología , Asma/etiología , Humanos , Obesidad/complicaciones , Obesidad/epidemiología , Prevalencia , Factores de Riesgo , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/epidemiología , Apnea Obstructiva del Sueño/terapiaRESUMEN
Background: The fractional exhaled nitric oxide (FENO) test is a point-of-care test that is used in the assessment of asthma. Objective: To provide evidence-based clinical guidance on whether FENO testing is indicated to optimize asthma treatment in patients with asthma in whom treatment is being considered. Methods: An international, multidisciplinary panel of experts was convened to form a consensus document regarding a single question relevant to the use of FENO. The question was selected from three potential questions based on the greatest perceived impact on clinical practice and the unmet need for evidence-based answers related to this question. The panel performed systematic reviews of published randomized controlled trials between 2004 and 2019 and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) evidence-to-decision framework to develop recommendations. All panel members evaluated and approved the recommendations. Main Results: After considering the overall low quality of the evidence, the panel made a conditional recommendation for FENO-based care. In patients with asthma in whom treatment is being considered, we suggest that FENO is beneficial and should be used in addition to usual care. This judgment is based on a balance of effects that probably favors the intervention; the moderate costs and availability of resources, which probably favors the intervention; and the perceived acceptability and feasibility of the intervention in daily practice. Conclusions: Clinicians should consider this recommendation to measure FENO in patients with asthma in whom treatment is being considered based on current best available evidence.
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Corticoesteroides/normas , Corticoesteroides/uso terapéutico , Antiasmáticos/normas , Antiasmáticos/uso terapéutico , Asma/diagnóstico , Asma/tratamiento farmacológico , Óxido Nítrico/análisis , Guías de Práctica Clínica como Asunto , Humanos , Estados UnidosRESUMEN
Elevated ambient temperatures and extreme weather events have increased the incidence of wildfires world-wide resulting in increased wood smoke particle (WSP). Epidemiologic data suggests that WSP exposure associates with exacerbations of respiratory diseases, and with increased respiratory viral infections. To assess the impact of WSP exposure on host response to viral pneumonia, we performed WSP exposures in rodents followed by infection with mouse adapted influenza (HINI-PR8). C57BL/6 male mice aged 6-8 weeks were challenged with WSP or PBS by oropharyngeal aspiration in acute (single dose) or sub-acute exposures (day 1, 3, 5, 7 and 10). Additional groups underwent sub-acute exposure followed by infection by influenza or heat-inactivated (HI) virus. Following exposures/infection, bronchoalveolar lavage (BAL) was performed to assess for total cell counts/differentials, total protein, protein carbonyls and hyaluronan. Lung tissue was assessed for viral counts by real time PCR. When compared to PBS, acute WSP exposure associated with an increase in airspace macrophages. Alternatively, sub-acute exposure resulted in a dose dependent increase in airspace neutrophils. Sub-acute WSP exposure followed by influenza infection was associated with improved respiratory viral outcomes including reduced weight loss and increased blood oxygen saturation, and decreased protein carbonyls and viral titers. Flow cytometry demonstrated dynamic changes in pulmonary macrophage and T cell subsets based on challenge with WSP and influenza. This data suggests that sub-acute WSP exposure can improve host response to acute influenza infection.
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Subtipo H1N1 del Virus de la Influenza A , Infecciones por Orthomyxoviridae , Neumonía Viral , Humo , Incendios Forestales , Administración por Inhalación , Animales , Subtipo H1N1 del Virus de la Influenza A/fisiología , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/virología , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Neumonía Viral/inmunología , Neumonía Viral/metabolismo , Neumonía Viral/virología , Índice de Severidad de la Enfermedad , Transcriptoma , Replicación Viral , MaderaRESUMEN
Surfactant protein-A (SP-A) is an important mediator of pulmonary immunity. A specific genetic variation in SP-A2, corresponding to a glutamine (Q) to lysine (K) amino acid substitution at position 223 of the lectin domain, was shown to alter the ability of SP-A to inhibit eosinophil degranulation. Because a large subgroup of asthmatics have associated eosinophilia, often accompanied by inflammation associated with delayed clearance, our goal was to define how SP-A mediates eosinophil resolution in allergic airways and whether genetic variation affects this activity. Wild-type, SP-A knockout (SP-A KO) and humanized (SP-A2 223Q/Q, SP-A2 223K/K) C57BL/6 mice were challenged in an allergic OVA model, and parameters of inflammation were examined. Peripheral blood eosinophils were isolated to assess the effect of SP-A genetic variation on apoptosis and chemotaxis. Five days postchallenge, SP-A KO and humanized SP-A2 223K/K mice had persistent eosinophilia in bronchoalveolar lavage fluid compared with wild-type and SP-A2 223Q/Q mice, suggesting an impairment in eosinophil resolution. In vitro, human SP-A containing either the 223Q or the 223K allele was chemoattractant for eosinophils whereas only 223Q resulted in decreased eosinophil viability. Our results suggest that SP-A aids in the resolution of allergic airway inflammation by promoting eosinophil clearance from lung tissue through chemotaxis, independent of SP-A2 Q223K, and by inducing apoptosis of eosinophils, which is altered by the polymorphism.
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Asma/complicaciones , Eosinofilia/fisiopatología , Proteína A Asociada a Surfactante Pulmonar/fisiología , Animales , Apoptosis/efectos de los fármacos , Quimiocina CCL11/análisis , Variación Genética , Humanos , Ratones , Ratones Endogámicos C57BL , Proteína A Asociada a Surfactante Pulmonar/genética , Proteína A Asociada a Surfactante Pulmonar/farmacologíaRESUMEN
The CD4Cre transgenic model has been widely used for T cell-specific gene manipulation. We report unexpected highly efficient Cre-mediated recombination in alveolar macrophages (AMFs), bronchial epithelial cells (BECs), and alveolar epithelial cells (AECs) in this strain of mice. Different from CD4 T cells, AMFs, AECs, and BECs do not express detectable Cre protein, suggesting that Cre protein is either very transiently expressed in these cells or only expressed in their precursors. Mice carrying a conditional constitutively active KRas (caKRas) allele and the CD4Cre transgene contain not only hyperactivated T cells but also develop severe AMF accumulation, AEC and BEC hyperplasia, and adenomas in the lung, leading to early lethality correlated with caKRas expression in these cells. We propose that caKRas-CD4Cre mice represent, to our knowledge, a novel model of proliferative pneumonitis involving macrophages and epithelial cells and that the CD4Cre model may offer unique usefulness for studying gene functions simultaneously in multilineages in the lung. Our observations, additionally, suggest that caution in data interpretation is warranted when using the CD4Cre transgenic model for T cell-specific gene manipulation, particularly when lung pathophysiological status is being examined.
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Células Epiteliales Alveolares/metabolismo , Antígenos CD4/genética , Integrasas/genética , Macrófagos Alveolares/metabolismo , Neumonía/etiología , Proteínas Proto-Oncogénicas p21(ras)/genética , Animales , Hiperplasia , Ratones , Ratones Endogámicos C57BL , Recombinación Genética , TransgenesRESUMEN
Human rhinovirus (RV), the major cause of the common cold, triggers the majority of acute airway exacerbations in patients with asthma and chronic obstructive pulmonary disease. Nitric oxide, and the related metabolite S-nitrosoglutathione, are produced in the airway epithelium via nitric oxide synthase (NOS) 2 and have been shown to function in host defense against RV infection. We hypothesized that inhibitors of the S-nitrosoglutathione-metabolizing enzyme, S-nitrosoglutathione reductase (GSNOR), might potentiate the antiviral properties of airway-derived NOS2. Using in vitro models of RV-A serotype 16 (RV-A16) and mNeonGreen-H1N1pr8 infection of human airway epithelial cells, we found that treatment with a previously characterized GSNOR inhibitor (4-[[2-[[(3-cyanophenyl)methyl]thio]-4-oxothieno-[3,2-d]pyrimidin-3(4H)-yl]methyl]-benzoic acid; referred to as C3m) decreased RV-A16 replication and expression of downstream proinflammatory and antiviral mediators (e.g., RANTES [regulated upon activation, normal T cell expressed and secreted], CXCL10, and Mx1), and increased Nrf2 (nuclear factor erythroid 2-related factor 2)-dependent genes (e.g., SQSTM1 and TrxR1). In contrast, C3m had no effect on influenza virus H1N1pr8 replication. Moreover, a structurally dissimilar GSNOR inhibitor (N6022) did not alter RV replication, suggesting that the properties of C3m may be specific to rhinovirus owing to an off-target effect. Consistent with this, C3m antiviral effects were not blocked by either NOS inhibition or GSNOR knockdown but appeared to be mediated by reduced intercellular adhesion molecule 1 transcription and increased shedding of soluble intercellular adhesion molecule 1 protein. Collectively these data show that C3m has novel antirhinoviral properties that may synergize with, but are unrelated to, its GSNOR inhibitor activity.
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Aldehído Oxidorreductasas/antagonistas & inhibidores , Bronquios/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Células Epiteliales/efectos de los fármacos , Inflamación/tratamiento farmacológico , Infecciones por Picornaviridae/tratamiento farmacológico , Rhinovirus/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Benzamidas/farmacología , Bronquios/metabolismo , Bronquios/virología , Células Cultivadas , Células Epiteliales/metabolismo , Células Epiteliales/virología , Humanos , Inflamación/metabolismo , Inflamación/virología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Infecciones por Picornaviridae/metabolismo , Infecciones por Picornaviridae/virología , Pirroles/farmacologíaRESUMEN
The innate immune components that modulate allergic contact hypersensitivity (CHS) responses are poorly defined. Using human skin from contact dermatitis patients and a mouse model of CHS, we find that hapten allergens disrupt the Arginase1 (Arg1) and inducible NO synthase (iNOS) dynamic in monocytes/macrophages (mono/MΦ), which renders those cells ineffectual in suppressing skin inflammation. Mice lacking Arg1 in MΦ develop increased CHS characterized by elevated ear thickening, mono/MΦ-dominated dermal inflammation, and increased iNOS and IL-6 expression compared with control mice. Treatment of Arg1flox/flox; LysMCre+/- mice with a selective NOS inhibitor or knockout of Nos2, encoding iNOS, significantly ameliorates CHS. Our findings suggest a critical role for Arg1 in mono/MΦ in suppressing CHS through dampening Nos2 expression. These results support that increasing Arg1 may be a potential therapeutic avenue in treating allergic contact dermatitis.
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Arginasa/metabolismo , Dermatitis Alérgica por Contacto/inmunología , Macrófagos/inmunología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Piel/inmunología , Alérgenos/inmunología , Animales , Arginasa/genética , Células Cultivadas , Dermatitis Alérgica por Contacto/genética , Modelos Animales de Enfermedad , Femenino , Haptenos/inmunología , Humanos , Inmunidad Innata , Interleucina-6/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico Sintasa de Tipo II/genéticaAsunto(s)
Asma , Obesidad Infantil , Niño , Humanos , Linfocitos T , Asma/inmunología , Músculo Liso , Miocitos del Músculo Liso , Linfocitos T CD4-PositivosRESUMEN
Background/aims The Food and Drug Administration Amendments Act mandates that applicable clinical trials report basic summary results to the ClinicalTrials.gov database within 1 year of trial completion or termination. We aimed to determine the proportion of pulmonary trials reporting basic summary results to ClinicalTrials.gov and assess factors associated with reporting. Methods We identified pulmonary clinical trials subject to the Food and Drug Administration Amendments Act (called highly likely applicable clinical trials) that were completed or terminated between 2008 and 2012 and reported results by September 2013. We estimated the cumulative percentage of applicable clinical trials reporting results by pulmonary disease category. Multivariable Cox regression modeling identified characteristics independently associated with results reporting. Results Of 1450 pulmonary highly likely applicable clinical trials, 380 (26%) examined respiratory neoplasms, 238 (16%) asthma, 175 (12%) chronic obstructive pulmonary disease, and 657 (45%) other respiratory diseases. Most (75%) were pharmaceutical highly likely applicable clinical trials and 71% were industry-funded. Approximately 15% of highly likely applicable clinical trials reported results within 1 year of trial completion, while 55% reported results over the 5-year study period. Earlier phase highly likely applicable clinical trials were less likely to report results compared to phase 4 highly likely applicable clinical trials (phases 1/2 and 2 (adjusted hazard ratio 0.41 (95% confidence interval: 0.31-0.54)), phases 2/3 and 3 (adjusted hazard ratio 0.55 (95% confidence interval: 0.42-0.72)) and phase not applicable (adjusted hazard ratio 0.43 (95% confidence interval: 0.29-0.63)). Pulmonary highly likely applicable clinical trials without Food and Drug Administration oversight were less likely to report results compared with those with oversight (adjusted hazard ratio 0.65 (95% confidence interval: 0.51-0.83)). Conclusion A total of 15% of pulmonary clinical highly likely applicable clinical trials report basic summary results to ClinicalTrials.gov within 1 year of trial completion. Strategies to improve reporting are needed within the pulmonary community.
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Ensayos Clínicos como Asunto/estadística & datos numéricos , Bases de Datos Factuales/estadística & datos numéricos , Documentación/estadística & datos numéricos , Enfermedades Respiratorias/terapia , Algoritmos , Ensayos Clínicos como Asunto/métodos , Ensayos Clínicos como Asunto/organización & administración , Organización de la Financiación/métodos , Humanos , Análisis de Regresión , Estados Unidos , United States Food and Drug Administration/normasRESUMEN
BACKGROUND: Compositional differences in the bronchial bacterial microbiota have been associated with asthma, but it remains unclear whether the findings are attributable to asthma, to aeroallergen sensitization, or to inhaled corticosteroid treatment. OBJECTIVES: We sought to compare the bronchial bacterial microbiota in adults with steroid-naive atopic asthma, subjects with atopy but no asthma, and nonatopic healthy control subjects and to determine relationships of the bronchial microbiota to phenotypic features of asthma. METHODS: Bacterial communities in protected bronchial brushings from 42 atopic asthmatic subjects, 21 subjects with atopy but no asthma, and 21 healthy control subjects were profiled by using 16S rRNA gene sequencing. Bacterial composition and community-level functions inferred from sequence profiles were analyzed for between-group differences. Associations with clinical and inflammatory variables were examined, including markers of type 2-related inflammation and change in airway hyperresponsiveness after 6 weeks of fluticasone treatment. RESULTS: The bronchial microbiome differed significantly among the 3 groups. Asthmatic subjects were uniquely enriched in members of the Haemophilus, Neisseria, Fusobacterium, and Porphyromonas species and the Sphingomonodaceae family and depleted in members of the Mogibacteriaceae family and Lactobacillales order. Asthma-associated differences in predicted bacterial functions included involvement of amino acid and short-chain fatty acid metabolism pathways. Subjects with type 2-high asthma harbored significantly lower bronchial bacterial burden. Distinct changes in specific microbiota members were seen after fluticasone treatment. Steroid responsiveness was linked to differences in baseline compositional and functional features of the bacterial microbiome. CONCLUSION: Even in subjects with mild steroid-naive asthma, differences in the bronchial microbiome are associated with immunologic and clinical features of the disease. The specific differences identified suggest possible microbiome targets for future approaches to asthma treatment or prevention.
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Asma/microbiología , Bronquios/microbiología , Hipersensibilidad Inmediata/microbiología , Microbiota , Administración por Inhalación , Corticoesteroides/uso terapéutico , Adulto , Asma/tratamiento farmacológico , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bronquios/efectos de los fármacos , Femenino , Fluticasona/uso terapéutico , Humanos , Hipersensibilidad Inmediata/tratamiento farmacológico , Masculino , Persona de Mediana Edad , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Adulto JovenRESUMEN
PURPOSE: Electronic cigarette (e-cigarette) use continues to rise among adolescents, but little is known regarding their risk perceptions of e-cigarette use. We aimed to describe the lifetime use and perceived risk of e-cigarette use in the context of other risk-taking behaviors among adolescents in North Carolina. METHODS: Data were derived from the 2015 North Carolina Youth Risk Behavior Survey, which was administered to 503 middle school and 444 high school students in the Chapel Hill-Carrboro public school district. Survey participants self-reported their sex; ethnicity; school grade; ever-use of cigarettes, e-cigarettes, alcohol, and other illicit substances; perceived risk of harm of these products; and perceived view of their parents' and friends' perceptions of these products. Logistic regression analyses were used to assess associations between student-reported characteristics, risk behaviors, perceived product risk, and ever-use of e-cigarettes. RESULTS: This study found that 4.6% of middle school students and 37.2% of high school students reported ever-use of e-cigarettes. E-cigarette use increased and perception of e-cigarette risk decreased with advancing grade. Ever-use of e-cigarettes surpassed ever-use of combustible cigarettes at all grades; 49.4% of e-cigarette users had never smoked cigarettes. The perception that friends view e-cigarette use as "wrong" correlated negatively with e-cigarette use (adjusted odds ratio = 0.43; 95% confidence interval, 0.19-0.97). LIMITATIONS: Self-reported results from students in one school district have limited generalizability to larger groups. CONCLUSION: E-cigarette use among adolescents in North Carolina correlates positively with perceived friends' views of e-cigarettes, and use correlates negatively with personal perception of the risk of e-cigarettes. Based on our survey results, education and public health intervention regarding e-cigarette use may be best targeted at youth prior to their transition to high school.