Airway Inflammation In Smokers Research Articles

Persistence of airway inflammation in smokers who switch to electronic cigarettes.

As opposed to smoking cessation with nicotine-replacement therapy and/or varenicline, nicotine-containing e-cigarette use does not improve some airway inflammatory markers. https://bit.ly/3FyqIt9

S-maltoheptaose targets syndecan-bound effectors to reduce smoking-related neutrophilic inflammation.

Cigarette smoke induces injury and neutrophilic inflammation in the airways of smokers. The stability and activity of inflammatory effectors, IL8 and neutrophil elastase (NE), can be prolonged by binding to airway heparan sulfate (HS)/syndecan-1, posing risk for developing chronic obstructive pulmonary disease(COPD). We hypothesize that antagonizing HS/syndecan-1 binding of the inflammatory effectors could reduce smoking-related neutrophil-mediated airway inflammation. Analysis of bronchoalveolar lavage fluid(BALF) of COPD patients found both total and unopposed NE levels to be significantly higher among smokers with COPD than non-COPD subjects. Similar NE burden was observed in smoke-exposed rats compared to sham air controls. We chose sulfated-maltoheptaose(SM), a heparin-mimetic, to antagonize HS/sydecan-1 binding of the inflammatory mediators in airway fluids and lung tissues of the smoke-exposed rat model. Airway treatment with SM resulted in displacement of CINC-1 and NE from complexation with bronchio-epithelial HS/syndecan-1, dissipating the chemokine gradient for neutrophil flux across to the bronchial lumen. Following SM displacement of NE from shed HS/syndecan-1 in bronchial fluids, NE became accessible to inhibition by α1-antitrypsin endogenous in test samples. The antagonistic actions of SM against syndecan-1 binding of NE and CINC-1 in smoke-exposed airways suggest new therapeutic opportunities for modulating airway inflammation in smokers with SM delivery.

Association of Lung Inflammatory Cells with Small Airways Function and Exhaled Breath Markers in Smokers - Is There a Specific Role for Mast Cells?

BackgroundSmoking is associated with a mixed inflammatory infiltrate in the airways. We evaluated whether airway inflammation in smokers is related to lung function parameters and inflammatory markers in exhaled breath.MethodsThirty-seven smokers undergoing lung resection for primary lung cancer were assessed pre-operatively by lung function testing including single-breath-nitrogen washout test (sb-N2-test), measurement of fractional exhaled nitric oxide (FeNO) and pH/8-isoprostane in exhaled breath condensate (EBC). Lung tissue sections containing cancer-free large (LA) and small airways (SA) were stained for inflammatory cells. Mucosal (MCT) respectively connective tissue mast cells (MCTC) and interleukin-17A (IL-17A) expression by mast cells was analysed using a double-staining protocol.ResultsThe median number of neutrophils, macrophages and mast cells infiltrating the lamina propria and adventitia of SA was higher than in LA. Both MCTC and MCT were higher in the lamina propria of SA compared to LA (MCTC: 49 vs. 27.4 cells/mm2; MCT: 162.5 vs. 35.4 cells/mm2; P<0.005 for both instances). IL-17A expression was predominantly detected in MCTC of LA. Significant correlations were found for the slope of phase III % pred. of the sb-N2-test (rs= -0.39), for the FEV1% pred. (rs= 0.37) and for FEV1/FVC ratio (rs=0.38) with MCT in SA (P<0.05 for all instances). 8-isoprostane concentration correlated with the mast cells in the SA (rs=0.44), there was no correlation for pH or FeNO with cellular distribution in SA.ConclusionsNeutrophils, macrophages and mast cells are more prominent in the SA indicating that these cells are involved in the development of small airway dysfunction in smokers. Among these cell types, the best correlation was found for mast cells with lung function parameters and inflammatory markers in exhaled breath. Furthermore, the observed predominant expression of IL-17A in mast cells warrants further investigation to elucidate their role in smoking-induced lung injury, despite the lack of correlation with lung function and exhaled breath parameters.

The relationship between pulmonary arterial and small airway inflammation in smokers with and without chronic obstructive pulmonary disease

To investigate the relationship between pulmonary arterial and small airway inflammation in smokers with normal lung function and smokers with chronic obstructive pulmonary disease (COPD). Patients requiring lung resection for peripheral lung cancer were divided into group A (nonsmokers with normal lung function, n = 10), group B (smokers with normal lung function, n = 13) and group C (smokers with stable COPD, n = 10). Normal pulmonary tissue was obtained more than 5 cm away from cancer lesion. The pathomorphological changes of the pulmonary muscularized arteries (MA) and small airways were observed by HE and Victoria blue-Van Gieson's stains.Lymphocytes infiltrated in the MA and small airways were observed by immunohistochemical methods. The characteristics and the correlations between pulmonary arterial inflammation and small airway inflammation were analyzed. The thickness of MA wall in the three groups was (119 ± 11), (139 ± 25) and (172 ± 28) µm respectively. The total small airway pathology score was (49 ± 10), (101 ± 34) and (163 ± 36) respectively. The score in group B and C was significantly higher than that in group A (P < 0.05), and the thickness of MA wall and total small airway pathology score in group C was significantly higher than that in group B (P < 0.05). The degree of CD(+)(3) T-lymphocytes and CD(+)(8) T-lymphocytes infiltration in the intima, media and adventitia of MA and epithelial layer, lamina propria and adventitia of small airway in group B and C was more significant than that in group A, especially CD(+)(8) T-lymphocytes infiltration in adventitia of MA and small airway (P < 0.05). Expression of CD(+)(4) T-lymphocytes on epithelial layer, lamina propria and adventitia of small airway in group C was higher than that in group A (P < 0.05), but the CD(+)(4)/CD(+)(8) ratio in the whole layer of airway wall declined (P < 0.01). Among three groups, the infiltration of B-lymphocytes in three layers compared each other had no statistical differences (P > 0.05). The infiltration of CD(+)(3)T-lymphocytes and CD(+)(8)T-lymphocytes in the whole layer of MA was positively correlated with the total small airway pathology score respectively (r = 0.431,0.633, P < 0.05), and the degree of CD(+)(3)T-lymphocytes and CD(+)(8)T-lymphocytes infiltration in MA showed positive correlation with that in small airway (r = 0.655,0.725, P < 0.01). The degree of CD(+)(8)T-lymphocytes infiltration in MA and small airway was positively correlated with thickness of MA (r = 0.589,0.556, P < 0.01). Both in smokers with normal lung function and smokers with stable COPD, CD(+)(8)T-lymphocytes infiltration in the whole layer of pulmonary arteries and small airways is the same kind of inflammation, mainly in the adventitia of pulmonary arteries and small airways. They are a part of pulmonary inflammation in COPD and promote the development of COPD.

Crotonaldehyde-exposed macrophages induce IL-8 release from airway epithelial cells through NF-κB and AP-1 pathways

Crotonaldehyde, a highly toxic α, β-unsaturated aldehyde, is a major component of cigarette smoke and a ubiquitous environmental pollutant. Crotonaldehyde exposure is known to have adverse effects on respiratory health, but the underlying mechanisms remain obscure. To examine the interaction between macrophages and airway epithelial cells after exposure to crotonaldehyde, BEAS-2B and A549 cells were treated with conditioned media from a human monocytic leukemia cell line (THP-1) cells stimulated with crotonaldehyde. We demonstrate that conditioned media from THP-1 cells stimulated with crotonaldehyde increased interleukin (IL)-8 production, enhanced nuclear factor (NF)-κB and AP-1 DNA-binding activity in BEAS-2B and A549 cells. Analysis of these conditioned media revealed marked increases in tumor necrosis factor (TNF)-α, IL-1β and IL-8 levels. Preincubation of conditioned media with either TNF-α- or IL-1β-neutralizing antibodies reduced IL-8 production. Furthermore, BEAS-2B and A549 cells directly treated with crotonaldehyde induced increase in IL-8 production. These data suggest that crotonaldehyde is capable of directly stimulating the production of IL-8 in both macrophages and airway epithelial cells. Crotonaldehyde-stimulated macrophages also amplify the inflammatory response by enhancing IL-8 release from airway epithelial cells mediated by NF-κB and AP-1 pathways through a mechanism involving TNF-α and IL-1β. These findings indicate that crotonaldehyde can cause lung inflammatory response via multiple mechanisms, and may contribute to chronic airway inflammation in smokers.

Year in review 2011: Asthma, chronic obstructive pulmonary disease and airway biology

1UBC James Hogg Research Centre, Institute for Heart + Lung Health, Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada, 2The Prince Charles Hospital and The University of Queensland, Brisbane, Queensland, Australia, 3Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, and 4Department of Medicine, National University Hospital, Singapore, Singapore

Effects of Smoking Cessation on Lung Function and Airway Inflammation in Smokers with Asthma

Effects of Smoking Cessation on Lung Function and Airway Inflammation in Smokers with Asthma

Effects of Smoking Cessation on Lung Function and Airway Inflammation in Smokers with Asthma

Active smoking in asthma is associated with worsening of symptoms, accelerated decline in lung function, and impaired response to corticosteroids. To examine the short-term effects of smoking cessation on lung function, airway inflammation, and corticosteroid responsiveness in smokers with asthma. Smokers with asthma were given the option to quit or continue smoking. Both groups underwent spirometry and induced sputum at baseline and at 1, 3, and 6 wk. Cutaneous vasoconstrictor response to topical beclometasone, airway response to oral prednisolone, and sensitivity of peripheral blood lymphocytes to corticosteroids were measured before smoking cessation and at 6 wk. Of 32 subjects recruited, 11 opted to continue smoking (smoking control group). Of 21 subjects who opted for smoking cessation, 10 quit smoking for 6 wk (quit group). In the comparison of quitters with smokers at 6 wk, the mean (confidence interval [CI]) difference in FEV(1) was 407 ml (21, 793), p = 0.040, and the proportion of sputum neutrophils was reduced by 29 (51, 8), p = 0.039. Total cutaneous vasoconstrictor response score to topical beclometasone improved after smoking cessation with a mean (CI) difference of 3.56 (0.84, 6.28), p = 0.042, between quitters and smokers. There was no change in airway corticosteroid responses after smoking cessation. By 6 wk after smoking cessation, subjects who quit smoking had achieved considerable improvement in lung function and a fall in sputum neutrophil count compared with subjects who continued to smoke. These findings highlight the importance of smoking cessation in asthma.

Airway inflammation and bronchial microbial patterns in patients with stable chronic obstructive pulmonary disease.

The effect of bacterial colonization of the bronchi on the progress of airflow limitation is not well known. Therefore, the pattern of airway inflammation in smokers and patients with stable chronic obstructive pulmonary disease (COPD) and its relation to bronchial microbial colonization was assessed. Eight nonsmoking and 18 smoking controls as well as 52 patients with COPD (28 mild, 11 moderate and 13 severe) were studied. All subjects were investigated by means of flexible bronchoscopy including protected specimen brush and bronchoalveolar lavage (BAL) sampling. Differential cell counts, cytokine (interleukin (IL)-1beta, IL-6, IL-8, IL-10 and tumour necrosis factor-alpha(TNF-alpha) concentrations and microbial patterns were determined in BAL fluid. Forced expiratory volume in one second (FEV1) % of the predicted value was inversely correlated with pack-yrs of cigarette smoking (r=-0.47, p<0.0001), the percentage of neutrophil (p=-0.56, p<0.0001) and IL-6 (p=-0.37, p=0.01) and IL-8 concentration (p=-0.43, p=0.004) in BAL fluid. Accordingly, pk-yrs of cigarette smoking (p=0.39, p=0.01) and IL-8 (p=0.69, p<0.0001) and TNFalpha (p=0.4, p<0.005) were positively correlated with the percentage of neutrophils in BAL fluid. Smoking controls and COPD patients were mainly colonized in the bronchial tree (33%) by community endogenous potentially pathogenic micro-organisms (PPMs). Colonization rates and patterns of PPMs were not affected by severity of airflow obstruction. The presence of PPMs was significantly associated with higher percentages of neutrophils (33.2+/-10.4% versus 10.1+/-3.5%, p=0.02) and TNF-alpha concentration (29.9+/-10.8 versus 6.3+/-2.1 pg x mL(-1), p=0.01) in BAL fluid. In conclusion, bronchial neutrophilia is a key inflammatory pattern in chronic obstructive pulmonary disease patients. Bronchial colonization with potentially pathogenic micro-organisms may represent an independent stimulus for additional airway inflammation.

Severity of Airflow Limitation Is Associated with Severity of Airway Inflammation in Smokers

To investigate the relationship between airflow limitation and airway inflammation in smokers, we examined paraffin-embedded bronchial biopsies obtained from 30 smokers: 10 with severe airflow limitation, eight with mild/moderate airflow limitation, and 12 control smokers with normal lung function. Histochemical and immunohistochemical methods were performed to assess the number of inflammatory cells in the subepithelium and the expression of CC chemokines macrophage inflammatory protein (MIP)-1alpha and -1beta in the bronchial mucosa. Compared with control smokers, smokers with severe airflow limitation had an increased number of neutrophils (p < 0.02), macrophages (p < 0.03), and NK lymphocytes (p < 0.03) in the subepithelium, and an increased number of MIP-1alpha+ epithelial cells (p < 0.02). When all smokers were considered together, the value of FEV1 was inversely correlated with the number of neutrophils (r = -0.59, p < 0.002), macrophages (r = -047, p < 0. 012), NK-lymphocytes (r = -0.51, p < 0.006) in the subepithelium, and with the number of MIP-1alpha+ epithelial cells (r = -0.61, p < 0.003). We conclude that in smokers the severity of airflow limitation is correlated with the severity of airway inflammation and that severe airflow limitation is associated with an increased number of neutrophils, macrophages, NK lymphocytes, and MIP-1alpha+ cells in the bronchial mucosa.

Cigarette smoke induces interleukin-8 release from human bronchial epithelial cells.

Cigarette smoking causes the development of chronic bronchitis and chronic obstructive pulmonary disease. We hypothesized that exposure to cigarette smoke might initiate release of inflammatory mediators by bronchial epithelial cells. To evaluate this, the effect of cigarette smoke extract (CSE) on IL-8 release from cultured human bronchial epithelial cells was examined. CSE augmented IL-8 release from bronchial epithelial cells in a concentration- and time-dependent manner. Most of the augmenting activity of CSE on IL-8 release from bronchial epithelial cells was lost after volatilization or lyophilization treatment. Two major volatile factors in cigarette smoke, acrolein and acetaldehyde, augmented IL-8 release. Four cell strains were tested and showed increased IL-8 release in response to CSE. In addition, bronchoalveolar lavage was performed on 11 nonsmokers and 12 smokers. IL-8 concentration was greater in the proximal, bronchial samples than in distal, alveolar samples, and IL-8 in BAL from smokers was higher than in BAL from nonsmokers. There was a significant correlation between IL-8 concentration and neutrophil count in bronchial samples of BAL fluid. These data support the hypothesis that exposure to cigarette smoke may induce bronchial epithelial cells to release IL-8 and that this may contribute to airway inflammation in smokers.

Airway inflammation in smokers with nonobstructive and obstructive chronic bronchitis.

To assess the manifestation and location of airway inflammation in smokers with chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD), we lavaged the airways of 12 smokers with CB and 11 smokers with COPD and coexisting CB (OCB). For comparison, the airways of 5 asymptomatic smokers (AS) and 10 healthy nonsmokers (HNS) were lavaged. In all cases, the first lavage aliquot, labeled "bronchial lavage" (BL), was processed separately from the four subsequent aliquots, which were combined and labeled "bronchoalveolar lavage" (BAL). The composition of BL and BAL fluids indicate an ongoing inflammatory process in the airways of all three groups of smokers. CB patients with obstruction had significantly lower concentrations of inflammatory cells in the BL and BAL fluids compared with subjects with nonobstructed CB. Furthermore, airway obstruction, indicated by a reduced FEV1, was significantly correlated with the concentrations of glutathione (p < 0.001), myeloperoxidase (MPO; p < 0.01), and eosinophil cationic protein (ECP; p < 0.01) in BAL fluids. Taken together, these findings suggest that the manifestations of inflammation present in the airways of smokers with CB are different in those who have developed obstruction compared with those who have not.