Increased leptin/leptin receptor pathway affects systemic and airway inflammation in COPD former smokers

Background: Leptin, a hormone produced mainly by adipose tissue, regulates food intake and energy expenditure. It is involved in inflammatory diseases such as chronic obstructive pulmonary disease (COPD) and its deficiency is associated with increased susceptibility to the infection. The leptin receptor is expressed in the lung and in the neutrophils. Methods: We measured the levels of leptin, tumor necrosis factor alpha (TNF-a) and soluble form of intercellular adhesion molecule-1 (sICAM-1) in sputum and plasma from 27 smoker and former smoker patients with stable COPD using ELISA methods. Further we analyzed leptin and its receptor expression in sputum cells from 16 COPD patients using immunocytochemistry. Results: In plasma of COPD patients, leptin was inversely correlated with TNF-a and positively correlated with the patient weight, whereas the levels of sICAM-1 were positively correlated with TNF-a. In sputum of COPD patients leptin levels were correlated with forced expiratory volume in 1 second/forced vitality capacity. Additionally, increased levels of sputum leptin and TNF-a were observed in COPD former smokers rather than smokers. Further the expression of leptin receptor in sputum neutrophils was significantly higher in COPD former smokers than in smokers, and the expression of leptin and its receptor was positively correlated in neutrophils of COPD former smokers. Conclusion: Our findings suggest a role of leptin in the local and systemic inflammation of COPD and, taking into account the involvement of neutrophils in this inflammatory disease, describe a novel aspect of the leptin/leptin receptor pathway in the regulation of host defense after smoking cessation

Effect of age and asthma duration upon elastase and alpha1-antitrypsin levels in adult asthmatics

In asthmatic subjects an imbalance between elastase and alpha1-antitrypsin (alpha1-PI) exists. This study aims to evaluate whether ageing per se affects the levels of elastase. Both young and elderly asthmatics with comparable severity and duration of disease, as well as young and elderly healthy subjects, underwent an induced sputum procedure to measure levels of elastase and alpha1-PI. The percentage of sputum neutrophils and eosinophils was higher in young and elderly asthmatics than in young and elderly controls. The levels of both total and active elastase were significantly higher in young and elderly asthmatics than in young and elderly controls, and directly correlated with the percentage of neutrophils. In addition, in both young and elderly asthmatics the levels of total and active elastase were negatively correlated with forced expiratory volume in one second values, but positively correlated with the duration of the disease. This study indicates that ageing per se does not necessarily lead to a progressive elastase/alpha1-antitrypsin imbalance in asthma, and suggests that an important variable in the development of airway remodelling in both young and elderly asthmatics is represented by the duration of the disease

Chronic obstructive pulmonary disease and neutrophil infiltration: role of cigarette smoke and cyclooxygenase products

Cigarette smoke is the main cause of chronic obstructive pulmonary disease (COPD), where it can contribute to the observed airway inflammation. PGE(2) is produced within human airways, and both pro- and anti-inflammatory activities have been reported. We quantitated PGE(2) concentrations in induced sputum supernatants from different groups of subjects and correlated the obtained values to neutrophil infiltration as well as to the expression of cyclooxygenase-2 (COX-2). Cigarette smoke extract (CSE) was used to evaluate the effect of smoking on COX-2 and PGE(2) receptor expression as well as on PGE(2) release in neutrophils and alveolar macrophages (AM) obtained from normal donors. The effects of PGE(2) and of PGE receptor agonists and antagonists were evaluated on the adhesion of neutrophil to a human bronchial epithelial cell line (16HBE). PGE(2) levels, COX-2 expression, and neutrophil infiltration were significantly higher in normal smokers and COPD smokers (P < 0.0001) compared with controls and COPD former smokers. Induced sputum supernatant caused neutrophil adhesion to 16HBE that was significantly reduced, in COPD smokers only, by PGE(2) immunoprecipitation. In vitro experiments confirmed that CSE increased PGE(2) release and COX-2 and PGE(2) receptor expression in neutrophils and AM; PGE(2) enhanced the adhesion of neutrophils to 16HBE, and a specific E-prostanoid 4 (EP(4)) receptor antagonist blunted its effect. These results suggest that CSE promote the induction of COX-2 and contributes to the proinflammatory effects of PGE(2) in the airways of COPD subjects.Cigarette smoke is the main cause of chronic obstructive pulmonary disease (COPD), where it can contribute to the observed airway inflammation. PGE(2) is produced within human airways, and both pro- and anti-inflammatory activities have been reported. We quantitated PGE(2) concentrations in induced sputum supernatants from different groups of subjects and correlated the obtained values to neutrophil infiltration as well as to the expression of cyclooxygenase-2 (COX-2). Cigarette smoke extract (CSE) was used to evaluate the effect of smoking on COX-2 and PGE(2) receptor expression as well as on PGE(2) release in neutrophils and alveolar macrophages (AM) obtained from normal donors. The effects of PGE(2) and of PGE receptor agonists and antagonists were evaluated on the adhesion of neutrophil to a human bronchial epithelial cell line (16HBE). PGE(2) levels, COX-2 expression, and neutrophil infiltration were significantly higher in normal smokers and COPD smokers (P < 0.0001) compared with controls and COPD former smokers. Induced sputum supernatant caused neutrophil adhesion to 16HBE that was significantly reduced, in COPD smokers only, by PGE(2) immunoprecipitation. In vitro experiments confirmed that CSE increased PGE(2) release and COX-2 and PGE(2) receptor expression in neutrophils and AM; PGE(2) enhanced the adhesion of neutrophils to 16HBE, and a specific E-prostanoid 4 (EP(4)) receptor antagonist blunted its effect. These results suggest that CSE promote the induction of COX-2 and contributes to the proinflammatory effects of PGE(2) in the airways of COPD subjects

“Leptin and leptin receptor expression in asthma”

Background: The adipokine leptin is a potential new mediator for bronchial epithelial homeostasis. Asthma is a chronic inflammatory disease characterized by airway remodeling that might affect disease chronicity and severity. TGF-b is a tissue growth factor the dysregulation of which is associated with airway remodeling. Objective: We sought to determine whether a bronchial epithelial dysfunction of the leptin/leptin receptor pathway contributes to asthma pathogenesis and severity. Methods: We investigated in vitro the presence of leptin/leptin receptor on human bronchial epithelial cells. Then we studied the effect of TGF-b and fluticasone propionate on leptin receptor expression. Finally, the role of leptin on TGF-b release and cell proliferation was analyzed. Ex vivo we investigated the presence of leptin/leptin receptor in the epithelium of bronchial biopsy specimens from subjects with asthma of various severities and from healthy volunteers, and some features of airway remodeling, such as reticular basement membrane (RBM) thickness and TGF-b expression in the epithelium, were assessed. Results: In vitro bronchial epithelial cells express leptin/leptin receptor. TGF-b decreased and fluticasone propionate increased leptin receptor expression, and leptin decreased the spontaneous release of TGF-b and increased cell proliferation. Ex vivo the bronchial epithelium of subjects with mild, uncontrolled, untreated asthma showed a decrease expression of leptin and its receptor and an increased RBM thickness and TGF-b expression when compared with values seen in healthy volunteers. Furthermore, severe asthma was associated with a reduced expression of leptin and its receptor and an increased RBM thickness with unaltered TGF-b expression. Conclusions: Decreased expression of leptin/leptin receptor characterizes severe asthma and is associated with airway remodeling features

Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners

Am J Physiol Lung Cell Mol Physiol. 2010 Jun;298(6):L857-62. Epub 2010 Apr 2. Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners. Chimenti L, Morici G, Paternò A, Santagata R, Bonanno A, Profita M, Riccobono L, Bellia V, Bonsignore MR. SourceDept. Biomedico Di Medicina Interna & Specialistica, Section of Pneumology, Univ. of Palermo, Via Trabucco 180, 90146 Palermo, Italy. [email protected] Abstract High neutrophil counts in induced sputum have been found in nonasthmatic amateur runners at rest and after a marathon, but the pathogenesis of airway neutrophilia in athletes is still poorly understood. Bronchial epithelial damage may occur during intense exercise, as suggested by investigations conducted in endurance-trained mice and competitive human athletes studied under resting conditions. To gain further information on airway changes acutely induced by exercise, airway cell composition, apoptosis, IL-8 concentration in induced sputum, and serum CC-16 level were measured in 15 male amateur runners at rest (baseline) and shortly after a half-marathon. Different from results obtained after a marathon, neutrophil absolute counts were unchanged, whereas bronchial epithelial cell absolute counts and their apoptosis increased significantly (P < 0.01). IL-8 in induced sputum supernatants almost doubled postrace compared with baseline (P < 0.01) and correlated positively with bronchial epithelial cell absolute counts (R(2) = 0.373, P < 0.01). Serum CC-16 significantly increased after all races (P < 0.01). These data show mild bronchial epithelial cell injury acutely induced by intense endurance exercise in humans, extending to large airways the data obtained in peripheral airways of endurance-trained mice. Therefore, neutrophil influx into the airways of athletes may be secondary to bronchial epithelial damage associated with intense exercise. PMID:20363849[PubMed - indexed for MEDLINE

15 (S)-HETE modulates LTB4 production and neutrophil chemotaxis in chronic bronchitis

We evaluated the levels of 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE] and the expression of 15-lipoxygenase (15-LO) mRNA in induced sputum obtained from 10 control and 15 chronic bronchitis subjects. 15(S)-HETE was evaluated by reverse phase high-performance liquid chromatography separation followed by specific RIA. 15-LO mRNA expression was determined by primed in situ labeling. The levels of both soluble and cell-associated 15(S)-HETE resulted significantly higher in chronic bronchitis than in control subjects. The percentage of cells expressing 15-LO mRNA was significantly higher in chronic bronchitis than in control subjects (P &lt; 0.01). Double staining for specific cell type markers and 15-LO mRNA showed macrophages and neutrophils positive for 15-LO, whereas similar staining of peripheral blood neutrophils did not show evidence for 15-LO expression, suggesting that expression of 15-LO in neutrophils takes place on migration into the airways. Because 15(S)-HETE inversely correlated with the percentage of neutrophils in sputum of chronic bronchitis subjects, we studied the effect of 15(S)-HETE on leukotriene B4 (LTB4) production in vitro and evaluated the concentration of LTB4 in induced sputum and the contribution of LTB4 to the chemotactic activity of induced sputum samples ex vivo. The results obtained indicate that macrophages and neutrophils present within the airways of chronic bronchitis subjects express 15-LO mRNA; increased basal levels of 15(S)-HETE may contribute to modulate, through the inhibition of 5-lipoxygenase metabolites production, neutrophil infiltration and airway inflammation associated with chronic bronchitis

The role of transforming growth factor-\u3b21 in airway inflammation of childhood asthma

TGF-beta-targeting structural and inflammatory cells has been implicated in the mechanisms leading to the inflammatory and restructuring processes in asthma, suggesting an impact of TGF-beta1 signaling on the development and persistency of this disease. We investigated the potential early involvement of TGF-beta1 activity in the immunological and molecular mechanisms underlying progression of inflammation in childhood asthma. We evaluated the levels of TGF-beta1 in induced sputum supernatants (ISSs) and the expression of small mother cell against decapentaplegic (Smad) 2 and Smad7 proteins in induced sputum cells (ISCs) from children with intermittent asthma (IA), moderate asthma (MA) and control subjects (C). Furthermore, we investigated the regulatory role of TGF-beta1 activity on eosinophil and neutrophil adhesion to epithelial cells using adhesion assay, and on the granulocyte expression of adhesion molecule CD11b/CD18 Macrophage-1 antigen (MAC-1), by flow cytometry. We found that the levels of TGF-beta1 are increased in ISSs of IA and MA in comparison to C, concomitantly to the activation of intracellular signaling TGFbeta/Smads pathway in ISCs. In MA, TGF-beta1 levels correlated with the number of sputum eosinophils and neutrophils. Furthermore, we showed the ability of sputum TGF-beta1 to promote eosinophil and neutrophil adhesion to epithelial cells, and to increase the expression of MAC-1 on the granulocyte surface. This study shows the activation of TGFbeta/Smad signaling pathway in the airways of children with IA and, despite the regular ICS treatment, in children with MA, and provides evidence for the contribution of TGF-beta1 in the regulation of granulocyte activation and trafficking

Role of chronic exsposure to cigarette smoke on endoglin/CD105 expression in airway epithelium.

Dysregulation of airway epithelial cell function related to cigarette smoke exposure plays an important role in the pathophysiology of COPD and is associated to tissue damage and disease severity. CD105 is a component of the receptor complex of TGF-β, a pleiotropic cytokine involved in cellular proliferation, differentiation and migration. CD105 regulates the expression of different components of the extracellular matrix suggesting a role of CD105 in cellular transmigration and remodeling processes. The aim of the present study was to investigate the expression of endoglin/CD105 in airway epithelium of COPD patients and its involvement in tissue remodeling and progression of COPD. We evaluated the immunoreactivity for CD105 expression in bronchial biopsies isolated from COPD patients and healthy controls (HC). The analysis of metaplastic epithelium was performed in bronchial biopsies by Image Analysis software (Leica Quantimet system). Finally, we investigated the expression of CD105 protein receptor in human bronchial epithelial cells (16HBE cells) exposed to 5% Cigarette Smoke Extract (CSE) for 12 days by western blot. We found that the CD105 immunoreactivity was significantly higher in bronchial epithelium of COPD than HC. Morphometric analysis of bioptic samples of COPD showed an increase of the immunoreactivity for CD105 in the area of metaplastic than in not metaplastic epithelium. Long term exposure to CSE significantly up-regulated CD105 expression in 16HBE. Chronic inflammation due to cigarette smoke might play a critic role on the alteration of CD105 protein expression in COPD, promoting tissue remodeling, angiogenesis and dysregulation of physiological reparative mechanisms, leading to squamous metaplasia

Reticulocytes in untreated Obstructive Sleep Apnoea

Background and Aim. The short, repetitive hypoxaemic episodes observed in obstructive sleep apnoea (OSA) may determine small augmentations in mature red blood cells. It is unknown whether they affect reticulocyte release. This study explored whether the number and degree of maturation of circulating reticulocytes may be altered in OSA, possibly through the effect of erythropoietin. Methods. Fifty male adult patients with suspected OSA, normoxic during wakefulness, were studied. After nocturnal polysomnography, a blood sample was withdrawn for blood cells count, erythropoietin, iron and transferrin determination. Reticulocyte concentration and degree of immaturity [high (H), medium (M), or low (L)] were also determined. Immature reticulocyte fraction (IRF) was calculated as (M+H) percentage of reticulocytes. Results. A wide range of OSA severity was found [apnoea/ hypopnoea index (AHI): 44.3±30.4, range 0.3-105; sleep time spent at oxyhaemoglobin saturation 2% had higher EPO levels (p<0.05), but not worse nocturnal desaturations, than those with values <2%. By contrast, subjects with IRF <15% showed worse desaturations (p<0.05), but similar EPO concentrations, when compared to subjects whose IRF was <10%. At univariate analysis, reticulocyte count correlated to erythropoietin, while IRF to transferrin saturation, BMI and OSA severity. At multiple regression, only lowest nocturnal oxygen saturation remained a significant contributor to IRF (r2 0.223, p<0.05). Conclusions. This data suggests that hypoxaemia due to OSA could influence the release of immature reticulocytes, but this effect is not mediated by erythropoietin

Airway cell composition at rest and after an all-out test in competitive rowers

Med Sci Sports Exerc. 2004 Oct;36(10):1723-9. Airway cell composition at rest and after an all-out test in competitive rowers. Morici G, Bonsignore MR, Zangla D, Riccobono L, Profita M, Bonanno A, Paternò A, Di Giorgi R, Mirabella F, Chimenti L, Benigno A, Vignola AM, Bellia V, Amato G, Bonsignore G. SourceDepartment of Experimental Medicine Italian National Research Council (CNR), Palermo, Italy. Abstract PURPOSES: This study was designed to assess: a) whether rowing affects airway cell composition, and b) the possible relationship between the degree of ventilation during exercise and airway cells. SUBJECTS AND METHODS: In nine young, nonasthmatic competitive rowers (mean age +/- SD: 16.2 +/- 1.0 yr), induced sputum samples were obtained at rest and shortly after an all-out rowing test over 1000 m (mean duration: 200 +/- 14 s), during which ventilatory and metabolic variables were recorded breath-by-breath (Cosmed K4b, Italy). RESULTS: At rest, induced sputum showed prevalence of neutrophils (60%) over macrophages (40%); after exercise, total cell and bronchial epithelial cell (BEC) counts tended to increase. In the last minute of exercise, mean VE was 158.0 +/- 41.5 L x min(-1), and VO2 x kg(-1) 62 +/- 11 mL x min(-1). Exercise VE correlated directly with postexercise total cell (Spearman rho: 0.75, P < 0.05) an dmacrophage (rho: 0.82, P < 0.05) counts. A similar trend was observed for exercise VE and changes in BEC counts from baseline to postexercise (rho: 0.64, P = 0.11). Exercise VE did not correlate with airway neutrophil counts at rest or after exercise. Expression of adhesion molecules by airway neutrophils, macrophages, and eosinophils decreased after the all-out test. CONCLUSION: Similar to endurance athletes, nonasthmatic competitive rowers showed increased neutrophils in induced sputum compared with values found in sedentary subjects. The trend toward increased BEC postexercise possibly reflected the effects of high airflows on airway epithelium. Airway macrophages postexercise were highest in rowers showing tile most intense exercise hyperpnea, suggesting early involvement of these cells during exercise. However, the low expression of adhesion molecules by all airway cell types suggests that intense short-lived exercise may be associated with a blunted response of airway cells in nonasthmatic well-trained rowers. PMID:15595293[PubMed - indexed for MEDLINE