RIPK1 kinase-dependent inflammation and cell death contribute to the pathogenesis of COPD.

BACKGROUND: Receptor-interacting protein kinase 1 (RIPK1) is a key mediator of regulated cell death (including apoptosis and necroptosis) and inflammation, both drivers of COPD pathogenesis. We aimed to define the contribution of RIPK1 kinase-dependent cell death and inflammation in the pathogenesis of COPD. METHODS: We assessed RIPK1 expression in single-cell RNA sequencing (RNA-seq) data from human and mouse lungs, and validated RIPK1 levels in lung tissue of COPD patients via immunohistochemistry. Next, we assessed the consequences of genetic and pharmacological inhibition of RIPK1 kinase activity in experimental COPD, using Ripk1 S25D/S25D kinase-deficient mice and the RIPK1 kinase inhibitor GSK'547. RESULTS: RIPK1 expression increased in alveolar type 1 (AT1), AT2, ciliated and neuroendocrine cells in human COPD. RIPK1 protein levels were significantly increased in airway epithelium of COPD patients compared with never-smokers and smokers without airflow limitation. In mice, exposure to cigarette smoke (CS) increased Ripk1 expression similarly in AT2 cells, and further in alveolar macrophages and T-cells. Genetic and/or pharmacological inhibition of RIPK1 kinase activity significantly attenuated airway inflammation upon acute and subacute CS exposure, as well as airway remodelling, emphysema, and apoptotic and necroptotic cell death upon chronic CS exposure. Similarly, pharmacological RIPK1 kinase inhibition significantly attenuated elastase-induced emphysema and lung function decline. Finally, RNA-seq on lung tissue of CS-exposed mice revealed downregulation of cell death and inflammatory pathways upon pharmacological RIPK1 kinase inhibition. CONCLUSIONS: RIPK1 kinase inhibition is protective in experimental models of COPD and may represent a novel promising therapeutic approach.

MiR-223 is increased in lungs of patients with COPD and modulates cigarette smoke-induced pulmonary inflammation.

Since microRNA (miR)-223-3p modulates inflammatory responses and chronic obstructive pulmonary disease (COPD) is associated with amplified pulmonary inflammation, we hypothesized that miR-223-3p plays a role in COPD pathogenesis. Expression of miR-223-3p was measured in lung tissue of two independent cohorts with patients with GOLD stage II-IV COPD, never smokers, and smokers without COPD. The functional role of miR-223-3p was studied in deficient mice and on overexpression in airway epithelial cells from COPD and controls. We observed higher miR-223-3p levels in patients with COPD stage II-IV compared with (non)-smoking controls, and levels were associated with higher neutrophil numbers in bronchial biopsies of patients with COPD. MiR-223-3p expression was also increased in lungs and bronchoalveolar lavage of cigarette smoke (CS)-exposed mice. CS-induced neutrophil and monocyte lung infiltration was stronger in miR-223-deficient mice on acute (5 days) exposure, but attenuated on subchronic (4 wk) exposure. Additionally, miR-223 deficiency attenuated acute and subchronic CS-induced lung infiltration of dendritic cells and T lymphocytes. Finally, in vitro overexpression of miR-223-3p in non-COPD airway epithelial cells suppressed C-X-C motif chemokine ligand 8 (CXCL8) and granulocyte monocyte-colony stimulation factor (GM-CSF) secretion and gene expression of the proinflammatory transcription factor TRAF6. Importantly, this suppressive effect of miR-223-3p was compromised in COPD-derived cultures. In conclusion, we demonstrate that miR-223-3p is increased in lungs of patients with COPD and CS-exposed mice and is associated with neutrophilic inflammation. In vivo data indicate that miR-223 acts as negative regulator of acute CS-induced neutrophilic and monocytic inflammation. In vitro data suggest that miR-223-3p does so by suppressing proinflammatory airway epithelial responses, which is less effective in COPD epithelium.

Quantification and role of innate lymphoid cell subsets in Chronic Obstructive Pulmonary Disease.

OBJECTIVES: Innate lymphoid cells (ILCs) secrete cytokines, such as IFN-γ, IL-13 and IL-17, which are linked to chronic obstructive pulmonary disease (COPD). Here, we investigated the role of pulmonary ILCs in COPD pathogenesis. METHODS: Lung ILC subsets in COPD and control subjects were quantified using flow cytometry and associated with clinical parameters. Tissue localisation of ILC and T-cell subsets was determined by immunohistochemistry. Mice were exposed to air or cigarette smoke (CS) for 1, 4 or 24 weeks to investigate whether pulmonary ILC numbers and activation are altered and whether they contribute to CS-induced innate inflammatory responses. RESULTS: Quantification of lung ILC subsets demonstrated that ILC1 frequency in the total ILC population was elevated in COPD and was associated with smoking and severity of respiratory symptoms (COPD Assessment Test [CAT] score). All three ILC subsets localised near lymphoid aggregates in COPD. In the COPD mouse model, CS exposure in C57BL/6J mice increased ILC numbers at all time points, with relative increases in ILC1 in bronchoalveolar lavage (BAL) fluid. Importantly, CS exposure induced increases in neutrophils, monocytes and dendritic cells that remained elevated in Rag2/Il2rg-deficient mice that lack adaptive immune cells and ILCs. However, CS-induced CXCL1, IL-6, TNF-α and IFN-γ levels were reduced by ILC deficiency. CONCLUSION: The ILC1 subset is increased in COPD patients and correlates with smoking and severity of respiratory symptoms. ILCs also increase upon CS exposure in C57BL/6J mice. In the absence of adaptive immunity, ILCs contribute to CS-induced pro-inflammatory mediator release, but are redundant in CS-induced innate inflammation.

Expression of ACE2, the SARS-CoV-2 Receptor, in Lung Tissue of Patients With Type 2 Diabetes.

Increased expression of pulmonary ACE2, the SARS-CoV-2 receptor, could contribute to increased infectivity of COVID-19 in patients with diabetes, but ACE2 expression has not been studied in lung tissue of subjects with diabetes. We therefore studied ACE2 mRNA and protein expression in lung tissue samples of subjects with and without diabetes that were collected between 2002 and 2020 from patients undergoing lobectomy for lung tumors. For RT-PCR analyses, samples from 15 subjects with diabetes were compared with 91 randomly chosen control samples. For immunohistochemical staining, samples from 26 subjects with diabetes were compared with 66 randomly chosen control samples. mRNA expression of ACE2 was measured by quantitative RT-PCR. Protein levels of ACE2 were visualized by immunohistochemistry on paraffin-embedded lung tissue samples and quantified in alveolar and bronchial epithelium. Pulmonary ACE2 mRNA expression was not different between subjects with or without diabetes. In contrast, protein levels of ACE2 were significantly increased in both alveolar tissue and bronchial epithelium of patients with diabetes compared with control subjects, independent of smoking, chronic obstructive pulmonary disease, BMI, renin-angiotensin-aldosterone system inhibitor use, and other potential confounders. To conclude, we show increased bronchial and alveolar ACE2 protein expression in patients with diabetes. Further research is needed to elucidate whether upregulation of ACE2 expression in airways and lungs has consequences on infectivity and clinical outcomes of COVID-19.

Innate lymphoid cells in isocyanate-induced asthma: role of microRNA-155.

BACKGROUND: Occupational asthma, induced by workplace exposures to low molecular weight agents such as toluene 2,4-diisocyanate (TDI), causes a significant burden to patients and society. Little is known about innate lymphoid cells (ILCs) in TDI-induced asthma. A critical regulator of ILC function is microRNA-155, a microRNA associated with asthma. OBJECTIVE: To determine whether TDI exposure modifies the number of ILCs in the lung and whether microRNA-155 contributes to TDI-induced airway inflammation and hyperresponsiveness. METHODS: C57BL/6 wild-type and microRNA-155 knockout mice were sensitised and challenged with TDI or vehicle. Intracellular cytokine expression in ILCs and T-cells was evaluated in bronchoalveolar lavage (BAL) fluid using flow cytometry. Peribronchial eosinophilia and goblet cells were evaluated on lung tissue, and airway hyperresponsiveness was measured using the forced oscillation technique. Putative type 2 ILCs (ILC2) were identified in bronchial biopsies of subjects with TDI-induced occupational asthma using immunohistochemistry. Human bronchial epithelial cells were exposed to TDI or vehicle. RESULTS: TDI-exposed mice had higher numbers of airway goblet cells, BAL eosinophils, CD4+ T-cells and ILCs, with a predominant type 2 response, and tended to have airway hyperresponsiveness. In TDI-exposed microRNA-155 knockout mice, inflammation and airway hyperresponsiveness were attenuated. TDI exposure induced IL-33 expression in human bronchial epithelial cells and in murine lungs, which was microRNA-155 dependent in mice. GATA3+CD3- cells, presumably ILC2, were present in bronchial biopsies. CONCLUSION: TDI exposure is associated with increased numbers of ILCs. The proinflammatory microRNA-155 is crucial in a murine model of TDI asthma, suggesting its involvement in the pathogenesis of occupational asthma due to low molecular weight agents.

Phenotype and Risk Burden of Sleep Apnea: A Population-Based Cohort Study.

Sleep apnea (SA) prevalence had increased. The socioeconomic burden is significant because of healthcare-related costs and adverse outcome, especially in moderate-to-severe SA. However, the population impact is unclear, particularly for mild SA. We aimed to assess the current prevalence and the cardiovascular risk associates of SA in the general population. We performed home polygraphy and extensive clinical, sociodemographic, and cardiovascular assessment in 2205 eligible subjects from a population-based cohort. Successful polygraphy was obtained in 1809 subjects (mean age, 56.0; SD, 5.9 years; 52.3% women). The prevalence was 41.0%, 11.8%, and 6.5% for mild, moderate, and severe SA in men and 26.6%, 4.4%, and 1.2% in women. Male sex, age, increasing BMI, and snoring were independently associated with SA, whereas sleepiness or tiredness were not. Compared with those without SA, mild SA was associated with (age- and sex-adjusted OR; 95% CI): diabetes mellitus (2.40; 1.52-3.80), hypertension (1.76; 1.42-2.19), left ventricular hypertrophy (1.36; 1.03-1.79), arterial plaques (1.19; 0.94-1.52), and increased IL-6 (interleukin-6) levels (1.37; 1.10-1.72). These associations were more pronounced in moderate-to-severe SA. To conclude, SA is highly prevalent in the middle-aged general population. It is largely undetected and undetectable using a symptom-based strategy. Yet, even the large group with mild SA shows a manifestly higher metabolic, inflammatory, and cardiovascular risk factor burden, with potential public health implications.

The once-daily fixed-dose combination of olodaterol and tiotropium in the management of COPD: current evidence and future prospects.

Long-acting bronchodilators are the cornerstone of pharmacologic treatment of chronic obstructive pulmonary disease (COPD). Spiolto® or Stiolto® is a fixed-dose combination (FDC) containing two long-acting bronchodilators, the long-acting muscarinic receptor antagonist tiotropium (TIO) and the long-acting ß2-adrenoceptor agonist olodaterol (OLO), formulated in the Respimat® Soft Mist™ inhaler. A total of 13 large, multicentre studies of up to 52 weeks' duration have documented its efficacy in more than 15,000 patients with COPD. TIO/OLO 5/5 µg FDC significantly increases pulmonary function compared with placebo and its respective constituent mono-components TIO 5 µg and OLO 5 µg. TIO/OLO 5/5 µg also results in statistically and clinically significant improvements in patient-reported outcomes, such as dyspnoea, use of rescue medication, and health status. Addition of OLO 5 µg to TIO 5 µg reduces the rate of moderate-to-severe exacerbations by approximately 10%. Compared with placebo and TIO 5 µg, TIO/OLO 5/5 µg significantly improves exercise capacity (e.g. endurance time) and physical activity, the latter increase being reached by a unique combination behavioural modification intervention, dual bronchodilatation and exercise training. Overall, the likelihood for patients to experience a clinically significant benefit is higher with TIO/OLO 5/5 µg than with its constituent mono-components, which usually yield smaller improvements which do not always reach statistical significance, compared with baseline or placebo. This supports the early introduction of TIO/OLO 5/5 µg in the management of patients with symptomatic COPD.

IL-33 signalling contributes to pollutant-induced allergic airway inflammation.

BACKGROUND: Clinical and experimental studies have identified a crucial role for IL-33 and its receptor ST2 in allergic asthma. Inhalation of traffic-related pollutants, such as diesel exhaust particles (DEP), facilitates the development of asthma and can cause exacerbations of asthma. However, it is unknown whether IL-33/ST2 signalling contributes to the enhancing effects of air pollutants on allergic airway responses. OBJECTIVE: We aim to investigate the functional role of IL-33/ST2 signalling in DEP-enhanced allergic airway responses, using an established murine model. METHODS: C57BL/6J mice were exposed to saline, DEP alone, house dust mite (HDM) alone or combined DEP+HDM. To inhibit IL-33 signalling, recombinant soluble ST2 (r-sST2) was given prophylactically (ie, during the whole experimental protocol) or therapeutically (ie, at the end of the experimental protocol). Airway hyperresponsiveness and the airway inflammatory responses were assessed in bronchoalveolar lavage fluid (BALF) and lung. RESULTS: Combined exposure to DEP+HDM increased IL-33 and ST2 expression in lung, elevated inflammatory responses and bronchial hyperresponsiveness compared to saline, sole DEP or sole HDM exposure. Prophylactic interference with the IL-33/ST2 signalling pathway impaired the DEP-enhanced allergic airway inflammation in the BALF, whereas effects on lung inflammation and airway hyperresponsiveness were minimal. Treatment with r-sST2 at the end of the experimental protocol did not modulate the DEP-enhanced allergic airway responses. CONCLUSION: Our data suggest that the IL-33/ST2 pathway contributes to the onset of DEP-enhanced allergic airway inflammation.

DPP4, the Middle East Respiratory Syndrome Coronavirus Receptor, is Upregulated in Lungs of Smokers and Chronic Obstructive Pulmonary Disease Patients.

Background: Middle East respiratory syndrome coronavirus (MERS-CoV) causes pneumonia with a relatively high case fatality rate in humans. Smokers and chronic obstructive pulmonary disease (COPD) patients have been reported to be more susceptible to MERS-CoV infection. Here, we determined the expression of MERS-CoV receptor, dipeptidyl peptidase IV (DPP4), in lung tissues of smokers without airflow limitation and COPD patients in comparison to nonsmoking individuals (never-smokers). Methods: DPP4 expression was measured in lung tissue of lung resection specimens of never-smokers, smokers without airflow limitation, COPD GOLD stage II patients and in lung explants of end-stage COPD patients. Both control subjects and COPD patients were well phenotyped and age-matched. The mRNA expression was determined using qRT-PCR and protein expression was quantified using immunohistochemistry. Results: In smokers and subjects with COPD, both DPP4 mRNA and protein expression were significantly higher compared to never-smokers. Additionally, we found that both DPP4 mRNA and protein expression were inversely correlated with lung function and diffusing capacity parameters. Conclusions: We provide evidence that DPP4 is upregulated in the lungs of smokers and COPD patients, which could partially explain why these individuals are more susceptible to MERS-CoV infection. These data also highlight a possible role of DPP4 in COPD pathogenesis.

microRNA profiling in lung tissue and bronchoalveolar lavage of cigarette smoke-exposed mice and in COPD patients: a translational approach.

Chronic obstructive pulmonary disease (COPD) is characterized by a progressive airflow limitation and is associated with a chronic inflammatory response in both airways and lungs. microRNAs (miRNAs) are often highly conserved between species and have an intricate role within homeostatic conditions and immune responses. Also, miRNAs are dysregulated in smoking-associated diseases. We investigated the miRNA profile of 523 miRNAs by stem-loop RT-qPCR in lung tissue and cell-free bronchoalveolar lavage (BAL) supernatant of mice exposed to air or cigarette smoke (CS) for 4 or 24 weeks. After 24 weeks of CS exposure, 31 miRNAs were differentially expressed in lung tissue and 78 in BAL supernatant. Next, we correlated the miRNA profiling data to inflammation in BAL and lung, obtained by flow cytometry or ELISA. In addition, we surveyed for overlap with newly assessed miRNA profiles in bronchial biopsies and with previously assessed miRNA profiles in lung tissue and induced sputum supernatant of smokers with COPD. Several miRNAs showed concordant differential expression between both species including miR-31*, miR-155, miR-218 and let-7c. Thus, investigating miRNA profiling data in different compartments and both species provided accumulating insights in miRNAs that may be relevant in CS-induced inflammation and the pathogenesis of COPD.

Epidemiology and impact of chronic bronchitis in chronic obstructive pulmonary disease.

Research on the association between chronic bronchitis and chronic obstructive pulmonary disease (COPD) exacerbations has led to discordant results. Furthermore, the impact of chronic bronchitis on mortality in COPD subjects is unclear.Within the Rotterdam Study, a population-based cohort study of subjects aged ≥45 years, chronic bronchitis was defined as having a productive cough for ≥3 months per year for two consecutive years. Linear, logistic regression and Cox proportional hazard models were adjusted for age, sex and pack-years.Out of 972 included COPD subjects, 752 had no chronic phlegm production (CB-) and 220 had chronic phlegm production, of whom 172 met the definition of chronic bronchitis (CB+). CB+ subjects were older, more frequently current smokers and had more pack-years than CB- subjects. During a median 6.5 years of follow-up, CB+ subjects had greater decline in lung function (-38 mL·year-1, 95% CI -61.7--14.6; p=0.024). CB+ subjects had an increased risk of frequent exacerbations (OR 4.0, 95% CI 2.7-5.9; p<0.001). In females, survival was significantly worse in CB+ subjects compared to CB- subjects. Regarding cause-specific mortality, CB+ subjects had an increased risk of respiratory mortality (hazard ratio 2.16, 95% CI 1.12-4.17; p=0.002).COPD subjects with chronic bronchitis have an increased risk of exacerbations and respiratory mortality compared to COPD subjects without chronic phlegm production.

Inhaled treatment of COPD: a Delphi consensus statement.

BACKGROUND: Global Initiative for Chronic Obstructive Lung Disease (GOLD) global strategy (2015) provides guidance for the treatment of chronic obstructive pulmonary disease (COPD) with different first-choice options per GOLD category without specification. OBJECTIVES: To evaluate the level of medical experts' consensus on their preferred first-choice treatment within different COPD categories. METHODS: A two-round Delphi Panel consisting of 15 questions was completed by Belgian pulmonologists (n=31) and European (n=10) COPD experts. RESULTS: Good consensus was reached by both expert groups for long-acting bronchodilators instead of short-acting bronchodilators as first-choice treatment in GOLD A. Single bronchodilation with long-acting muscarinic antagonist (LAMA) was preferred over long-acting ß2-agonist (LABA) and LABA/LAMA as first-choice treatment in GOLD B and GOLD C. For GOLD D patients based on the forced expiratory volume in 1 second (FEV1)<50%, a very good consensus was reached for LAMA/LABA as first-choice treatment. For GOLD D patients based on frequent or severe exacerbations, there was a good consensus for LABA/LAMA/inhaled corticosteroids (ICS) as first choice in the Belgian group. According to the European experts, both LABA/LAMA and LABA/LAMA/ICS could be the first choice for these patients. CONCLUSION: Belgian and European experts recommend long-acting bronchodilators as first-choice treatment. Treatment containing ICS was found only appropriate in patients with FEV1<50% and ≥2 moderate exacerbations or 1 severe exacerbation/year.

Dysregulation of type 2 innate lymphoid cells and TH2 cells impairs pollutant-induced allergic airway responses.

BACKGROUND: Although the prominent role of TH2 cells in type 2 immune responses is well established, the newly identified type 2 innate lymphoid cells (ILC2s) can also contribute to orchestration of allergic responses. Several experimental and epidemiologic studies have provided evidence that allergen-induced airway responses can be further enhanced on exposure to environmental pollutants, such as diesel exhaust particles (DEPs). However, the components and pathways responsible remain incompletely known. OBJECTIVE: We sought to investigate the relative contribution of ILC2 and adaptive TH2 cell responses in a murine model of DEP-enhanced allergic airway inflammation. METHODS: Wild-type, Gata-3+/nlslacZ (Gata-3-haploinsufficient), RAR-related orphan receptor α (RORα)fl/flIL7RCre (ILC2-deficient), and recombination-activating gene (Rag) 2-/- mice were challenged with saline, DEPs, or house dust mite (HDM) or DEP+HDM. Airway hyperresponsiveness, as well as inflammation, and intracellular cytokine expression in ILC2s and TH2 cells in the bronchoalveolar lavage fluid and lung tissue were assessed. RESULTS: Concomitant DEP+HDM exposure significantly enhanced allergic airway inflammation, as characterized by increased airway eosinophilia, goblet cell metaplasia, accumulation of ILC2s and TH2 cells, type 2 cytokine production, and airway hyperresponsiveness compared with sole DEPs or HDM. Reduced Gata-3 expression decreased the number of functional ILC2s and TH2 cells in DEP+HDM-exposed mice, resulting in an impaired DEP-enhanced allergic airway inflammation. Interestingly, although the DEP-enhanced allergic inflammation was marginally reduced in ILC2-deficient mice that received combined DEP+HDM, it was abolished in DEP+HDM-exposed Rag2-/- mice. CONCLUSION: These data indicate that dysregulation of ILC2s and TH2 cells attenuates DEP-enhanced allergic airway inflammation. In addition, a crucial role for the adaptive immune system was shown on concomitant DEP+HDM exposure.

MicroRNA Profiling Reveals a Role for MicroRNA-218-5p in the Pathogenesis of Chronic Obstructive Pulmonary Disease.

RATIONALE: Aberrant expression of microRNAs (miRNAs) can have a detrimental role in disease pathogenesis. OBJECTIVES: To identify dysregulated miRNAs in lung tissue of patients with chronic obstructive pulmonary disease (COPD). METHODS: We performed miRNA and mRNA profiling using high throughput stem-loop reverse-transcriptase quantitative polymerase chain reaction and mRNA microarray, respectively, on lung tissue of 30 patients (screening cohort) encompassing 8 never-smokers, 10 smokers without airflow limitation, and 12 smokers with COPD. Differential expression of miRNA-218-5p (miR-218-5p) was validated by reverse-transcriptase quantitative polymerase chain reaction in an independent cohort of 71 patients, an in vivo murine model of COPD, and primary human bronchial epithelial cells. Localization of miR-218-5p was assessed by in situ hybridization. In vitro and in vivo perturbation of miR-218-5p combined with RNA sequencing and gene set enrichment analysis was used to elucidate its functional role in COPD pathogenesis. MEASUREMENTS AND MAIN RESULTS: Several miRNAs were differentially expressed among the different patient groups. Interestingly, miR-218-5p was significantly down-regulated in smokers without airflow limitation and in patients with COPD compared with never-smokers. Decreased pulmonary expression of miR-218-5p was validated in an independent validation cohort, in cigarette smoke-exposed mice, and in human bronchial epithelial cells. Importantly, expression of miR-218-5p strongly correlated with airway obstruction. Furthermore, cellular localization of miR-218-5p in human and murine lung revealed highest expression of miR-218-5p in the bronchial airway epithelium. Perturbation experiments with a miR-218-5p mimic or inhibitor demonstrated a protective role of miR-218-5p in cigarette smoke-induced inflammation and COPD. CONCLUSIONS: We highlight a role for miR-218-5p in the pathogenesis of COPD.

Alcohol hyper-responsiveness in chronic rhinosinusitis with nasal polyps.

BACKGROUND: An important percentage of subjects diagnosed with chronic upper airway disease report alcohol-induced worsening of their symptoms. The prevalence and characteristics of respiratory reactions provoked by alcohol-containing drinks have not been fully investigated yet. OBJECTIVE: The aim of this study was to estimate the prevalence and characteristics of alcohol hyper-responsiveness in patients with chronic airway disease and healthy controls. Furthermore, nasal inflammation was evaluated in nasal polyp patients with and without hyper-responsiveness. METHODS: We evaluated the prevalence and characteristics of alcohol-induced respiratory complaints in 1281 subjects. Chronic rhinosinusitis with nasal polyps (CRSwNP) patients with and without NSAID exacerbated respiratory disease (NERD), chronic rhinosinusitis patients without nasal polyps (CRSsNP), allergic rhinitis (AR) patients and healthy controls were approached by means of a questionnaire. Inflammatory markers (eosinophilic cationic protein (ECP), IL-5, IgE, SAE-specific IgE, IL-17, TNFα and IFNγ) in tissue were then compared between alcohol hyper-responsive and non-hyper-responsive CRSwNP patients. RESULTS: The highest prevalence of nasal and bronchial alcohol hyper-responsiveness was observed in patients with NERD, followed by CRSwNP, and less frequent in CRSsNP, AR and healthy controls. Alcohol hyper-responsiveness is significantly more prevalent in CRSwNP patients suffering from recurrent disease and in patients with severe symptomatology. In nasal tissue of the hyper-responsive CRSwNP group, we observed significantly higher nasal levels of the eosinophilic biomarker ECP. CONCLUSION AND CLINICAL RELEVANCE: Nasal hyper-responsiveness to alcohol is significantly more prevalent in severe eosinophilic upper airway disease.

Efficacy of tiotropium-olodaterol fixed-dose combination in COPD.

Tiotropium-olodaterol, formulated in the Respimat soft-mist inhaler, is an inhaled fixed-dose combination (FDC) of a long-acting muscarinic antagonist (LAMA) and a long-acting ß2-agonist (LABA), commercialized under the name of Spiolto or Stiolto. The efficacy of tiotropium-olodaterol 5-5 µg once daily in adult patients with COPD was documented in eleven large, multicenter trials of up to 52 weeks duration. Tiotropium-olodaterol 5-5 µg not only improved spirometric values to a significantly greater extent than placebo but also resulted in statistically significant beneficial effects on dyspnea, markers of hyperinflation, use of rescue medication, health-related quality of life, and exercise endurance. Improvements exceeded the minimal clinically important difference (MCID) for forced expiratory volume in 1 second (FEV1), dyspnea, and quality of life. Differences between tiotropium-olodaterol 5-5 µg and the respective monocomponents were statistically significant for FEV1, dyspnea, markers of hyperinflation, use of rescue medication, and health-related quality of life, but did not reach the MCID. However, dual bronchodilatation significantly increased the number of patients who exceeded the MCID for dyspnea and quality of life. Moreover, tiotropium-olodaterol 5-5 µg was significantly more effective than salmeterol-fluticasone (FDC) twice daily at improving pulmonary function. Differences between tiotropium-olodaterol and other LAMA/LABA FDCs were not observed for FEV1 or other efficacy markers. Therefore, tiotropium-olodaterol is a valuable option in the treatment of COPD patients who remain symptomatic under monotherapy.

Asthma inflammatory phenotypes show differential microRNA expression in sputum.

BACKGROUND: Asthma is classified according to severity and inflammatory phenotype and is likely to be distinguished by specific microRNA (miRNA) expression profiles. OBJECTIVE: We sought to associate miRNA expression in sputum supernatants with the inflammatory cell profile and disease severity in asthmatic patients. METHODS: We investigated miRNA expression in sputum supernatants of 10 healthy subjects, 17 patients with mild-to-moderate asthma, and 9 patients with severe asthma using high-throughput, stem-loop, reverse transcriptase quantitative real-time PCR miRNA expression profiling (screening cohort, n = 36). Differentially expressed miRNAs were validated in an independent cohort (n = 60; 10 healthy subjects and 50 asthmatic patients). Cellular miRNA origin was examined by using in situ hybridization and reverse transcriptase quantitative real-time PCR. The functional role of miRNAs was assessed by using in silico analysis and in vitro transfecting miRNA mimics in human bronchial epithelial cells. RESULTS: In 2 independent cohorts expression of miR-629-3p, miR-223-3p, and miR-142-3p was significantly upregulated in sputum of patients with severe asthma compared with that in healthy control subjects and was highest in patients with neutrophilic asthma. Expression of the 3 miRNAs was associated with sputum neutrophilia, and miR-223-3p and miR-142-3p expression was associated also with airway obstruction (FEV1/forced vital capacity). Expression of miR-629-3p was localized in the bronchial epithelium, whereas miR-223-3p and miR-142-3p were expressed in neutrophils, monocytes, and macrophages. Transfecting human bronchial epithelial cells with miR-629-3p mimic induced epithelial IL-8 mRNA and protein expression. IL-1ß and IL-8 protein levels were significantly increased in sputum of patients with severe asthma and were positively associated with sputum neutrophilia. CONCLUSIONS: Expression of miR-223-3p, miR-142-3p, and miR-629-3p is increased in sputum of patients with severe asthma and is linked to neutrophilic airway inflammation, suggesting that these miRNAs contribute to this asthma inflammatory phenotype.

Pro- and Anti-Inflammatory Role of ChemR23 Signaling in Pollutant-Induced Inflammatory Lung Responses.

Inhalation of traffic-related particulate matter (e.g., diesel exhaust particles [DEPs]) is associated with acute inflammatory responses in the lung, and it promotes the development and aggravation of allergic airway diseases. We previously demonstrated that exposure to DEP was associated with increased recruitment and maturation of monocytes and conventional dendritic cells (DCs), resulting in TH2 polarization. Monocytes and immature DCs express the G-protein coupled receptor chemR23, which binds the chemoattractant chemerin. Using chemR23 knockout (KO) and corresponding wild-type (WT) mice, we determined the role of chemR23 signaling in response to acute exposure to DEPs and in response to DEP-enhanced house dust mite (HDM)-induced allergic airway inflammation. Exposure to DEP alone, as well as combined exposure to DEP plus HDM, elevated the levels of chemerin in the bronchoalveolar lavage fluid of WT mice. In response to acute exposure to DEPs, monocytes and monocyte-derived DCs accumulated in the lungs of WT mice, but this response was significantly attenuated in chemR23 KO mice. Concomitant exposure to DEP plus HDM resulted in allergic airway inflammation with increased eosinophilia, goblet cell metaplasia, and TH2 cytokine production in WT mice, which was further enhanced in chemR23 KO mice. In conclusion, we demonstrated an opposing role for chemR23 signaling depending on the context of DEP-induced inflammation. The chemR23 axis showed proinflammatory properties in a model of DEP-induced acute lung inflammation, in contrast to anti-inflammatory effects in a model of DEP-enhanced allergic airway inflammation.

Characterization and Quantification of Innate Lymphoid Cell Subsets in Human Lung.

BACKGROUND: Innate lymphoid cells (ILC) are a new family of innate immune cells that have emerged as important regulators of tissue homeostasis and inflammation. However, limited data are available concerning the relative abundance and characteristics of ILC in the human lung. METHODS: The aim of this study was to characterize and enumerate the different ILC subsets in human lung by multi-color flow cytometry. RESULTS: Within the CD45+ Lin- CD127+ pulmonary ILC population, we identified group 1 (ILC1), group 2 (ILC2) and group 3 (ILC3) innate lymphoid cells using specific surface markers (i.e. IL12Rß2, CRTH2 and CD117 respectively) and key transcription factors (i.e. T-bet, GATA-3 and RORγT respectively). Based on the presence of NKp44, ILC3 were further subdivided in natural cytotoxicity receptor (NCR)+ and NCR- ILC3. In addition, we demonstrated the production of signature cytokines IFN-γ, IL-5, IL-17A, IL-22 and GM-CSF in the pulmonary ILC population. Interestingly, we observed a tendency to a higher frequency of NCR- ILC3 in lungs of patients with chronic obstructive pulmonary disease (COPD) compared with controls. CONCLUSIONS: We show that the three main ILC subsets are present in human lung. Importantly, the relative abundance of ILC subsets tended to change in COPD patients in comparison to control individuals.