transforming-growth-factor-beta and Bronchitis

The requirement for precise geometric organization of endothelial cells and epithelial cells makes the gas-exchange region of the lung especially vulnerable to the adverse consequences of toxic products released from inflammatory cells. However, as a filter for large volumes of atmospheric gas, the lung is continually exposed to microorganisms and other toxic insults that require robust inflammatory defense. Enhanced production of extracellular matrix proteins is one important mechanism for restricting tissue damage, but excessive matrix production also has serious adverse effects on gas exchange. The amazing ability of the lung to recover from a barrage of environmental insults depends on precisely regulating both inflammation and extracellular matrix production in space and time. Below I review some of the evidence implicating members of the transforming growth factor beta family as critical mediators of this delicate dance and describe examples of how disruption of this balance by alterations in the magnitude of spatially restricted transforming growth factor beta activation can contribute to pathologic consequences of alveolar and airway injury and inflammation.

Topics: Animals; Bronchitis; Humans; Lung Diseases, Interstitial; Pulmonary Fibrosis; Transforming Growth Factor beta

COPD is characterized by chronic inflammation and injury of both the airways and the parenchymal structures of the lung. These processes are associated with ongoing repair. Whether repair leads to restoration of normal tissue architecture or to altered tissue structure with loss of function depends on complex interrelationships of a variety of interacting mediators. The possibility that repair processes can be modulated by exogenous agents raises the possibility that therapeutic strategies aimed at repair can be effective. Such strategies offer tremendous promise both for slowing the relentlessly progressive natural history which most often characterizes COPD and, possibly, for restoring lung function. Rennard SI. Inflammation and repair processes in chronic obstructive pulmonary disease.

Topics: Animals; Bronchitis; Cell Division; Cell Movement; Fibronectins; Humans; Lung Diseases, Obstructive; Pneumonia; Respiratory Mucosa; Transforming Growth Factor beta; Wound Healing

High-altitude climate therapy is a well-established therapeutic option, which improves clinical symptoms in asthma. However, little is known about the underlying immunological mechanisms. The study investigates the influence of high-altitude climate therapy on airway inflammation and cellular components of specific and unspecific immune response. Exhaled NO significantly decreased within 3 weeks of therapy in patients with allergic and intrinsic, moderate and severe asthma. Interleukin-10 (IL-10)-secreting peripheral blood mononuclear cells (PBMC) increased within 3 weeks of therapy in six of 11 patients, whereas transforming growth factor-beta(1)-secreting PBMC remained stable. Furthermore, monocyte activation, assessed by CD80 expression significantly decreased during therapy. The frequency of CRTH2-expressing T cells decreased, while regulatory T cells (T(reg)) remained stable. FOXP3 and GATA-3 mRNA expression in CD4(+) T cells did not change, while interferon-gamma and IL-13 mRNA expression decreased in eight of 10 patients. The current data demonstrate that high-altitude climate therapy reduces local airway inflammation. Furthermore, monocytes switch towards a tolerogenic phenotype under high-altitude climate therapy. The T(reg)/Th2 ratio increases; however, because of the absence of antigens/allergens, no de novo differentiation of Th2 nor T(reg) cells is observed. The high-altitude climate therapy therefore may form the immunological basis for the endogenous control of allergen-driven diseases.

Topics: Adult; Altitude; Antigen-Presenting Cells; Asthma; Bronchitis; Climate; GATA3 Transcription Factor; Humans; Interferon-gamma; Interleukin-10; Interleukin-13; L-Selectin; Lymphocyte Activation; Middle Aged; Nitric Oxide; Receptors, Immunologic; Receptors, Prostaglandin; T-Lymphocytes, Regulatory; Transcription Factors; Transforming Growth Factor beta

Chronic non-asthmatic cough (CC) is a clinical challenge and underlying pathophysiological mechanisms remain still not completely understood. One of the most common comorbidities in CC is gastro-oesophageal reflux disease (GORD). Airway epithelium damage can contribute to airway inflammation in CC.. We studied airway inflammation in patients with CC compared to healthy controls. Patients with GORD were treated with proton pump inhibitors (PPI) and cough response to PPI was evaluated.. Sputum was induced in 41 adults with CC and 20 healthy non-smokers who were age and sex matched. We compared sputum differential cell count by cytospin and cytokine and chemokine production at the mRNA and/or protein levels by real-time (RT)-PCR and cytokine bead array (CBA), between patients with CC and healthy subjects. Furthermore we studied airway inflammation in patients with different comorbidities.. No differences in sputum differential cell counts were observed between patients with CC and healthy subjects. Sputum monocyte chemoattractant protein-1 (MCP-1) protein levels were significantly higher in patients when compared to controls. Thymic stromal lymphopoietin (TSLP) mRNA was significantly more often expressed in sputum of patients with CC than from healthy controls. Sputum transforming growth factor (TGF)-β levels did not differ between patients and controls, but were significantly lower in the PPI responders compared to the non-responders; p=0.047. There is no evidence for impaired T helper cell (Th)1/Th2/Th17 balance in CC. Patients with reflux oesophagitis (RO) have significantly more sputum eosinophils than patients without RO.. CC is a condition presenting with different disease phenotypes. High sputum MCP-1 levels are present in a large group of patients with CC and a majority of these patients with CC have increased sputum TSLP levels, most likely produced by damaged airway epithelial cells.

Topics: Adult; Bronchi; Bronchitis; Cell Count; Chemokine CCL2; Comorbidity; Cough; Cytokines; Female; Gastroesophageal Reflux; Humans; Inflammation; Male; Middle Aged; Phenotype; Proton Pump Inhibitors; Sputum; Thymic Stromal Lymphopoietin; Transforming Growth Factor beta

Obliterative bronchiolitis (OB), a fibrotic airway lesion, is the leading cause of death after lung transplantation. Type V collagen [col(V)] overexpression and IL-17-mediated anti-col(V) immunity are key contributors to OB pathogenesis. Here, we report a previously undefined role of IL-17 in inducing col(V) overexpression, leading to epithelial mesenchymal transition (EMT) and subsequent OB. We observed IL-17-mediated induction of col(V) α1 chains [α1 (V)] in normal airway epithelial cells in vitro and detected α1 (V)-specific antibodies in bronchoalveolar lavage fluid of lung transplant patients. Overexpression of IL-17 and col(V) was detected in OB lesions in patient lung biopsies and in a murine OB model. IL-17 is shown to induce EMT, TGF-β mRNA expression, and SMAD3 activation, whereas downregulating SMAD7 expression in vitro. Pharmacological inhibition of TGF-βRI tyrosine kinase, p38 MAPK, or focal adhesion kinase prevented col(V) overexpression and EMT. In murine orthotopic lung transplants, neutralizing IL-17 significantly decreased TGF-β mRNA and protein expression and prevented epithelial repair/OB. Our findings highlight a feed-forward loop between IL-17 and TGF-β, leading to induction of col(V) and associated epithelial repair, thus providing one possible link between autoimmunity and OB after lung transplantation.

Topics: Animals; Autoantibodies; Bronchitis; Cell Movement; Cells, Cultured; Collagen Type V; Epithelial-Mesenchymal Transition; Female; Gene Expression; Gene Expression Regulation; Humans; Interleukin-17; Lung Transplantation; Male; Mice; Middle Aged; Primary Cell Culture; Rats; Respiratory Mucosa; Signal Transduction; Transforming Growth Factor beta

Exposure to allergens or air pollutants often leads to asthma exacerbations associated with aggravation of airway inflammation. Although, repeated allergen challenge often induces chronic allergic airway inflammation (CAAI) and airway remodelling, yet, the effects of brief exposure to air pollutants such as SO(2) on development of CAAI and airway remodelling remain to be clarified.. The aim of the experiment was to investigate the effects of acute neutrophilic airway inflammation induced by brief exposure to SO(2) on development of CAAI and subepithelial fibrosis (SEF) in a murine model of asthma.. Acute airway inflammation was induced by brief exposure to 50 p.p.m. SO(2) (1 h/d, 3 days). CAAI and SEF in BALB/c mice were induced by repeated challenge with ovalbumin (OVA) for 5 or 9 weeks with or without prior exposure to SO(2). Bronchoalveolar lavage fluid (BALF) eosinophilia as index of CAAI, BALF endothelin-1 (ET-1) and TGF-beta1 levels, morphometric evaluation of fibrotic area beneath subbasement membrane and lung hydroxyproline content (Hyp) as indexes of SEF were monitored.. Exposure to SO(2) led to acute neutrophilic inflammation and epithelial sloughing with profound elevation of BALF ET-1. Repeated OVA challenge resulted in CAAI and SEF along with elevation of Hyp, increase of fibrotic area beneath subbasement membrane and elevation of BALF TGF-beta1. Preceding SO(2) exposure exaggerated BALF eosinophilia, facilitated and enhanced SEF with more significant elevation of BALF ET-1 and TGF-beta1 levels compared with OVA-challenged mice without prior exposure to SO(2). The increase of Hyp was positively correlated with elevation of BALF TGF-beta1 during CAAI (r=0.842, P<0.01).. This data demonstrated that SEF developed in parallel with severity and time course of CAAI following repeated OVA challenge. SO(2)-induced acute epithelial injury and neutrophilic inflammation could enhance CAAI and promote SEF, probably through overexpression of ET-1 and TGF-beta1.

Topics: Air Pollutants; Allergens; Animals; Bronchitis; Bronchoalveolar Lavage Fluid; Chronic Disease; Endothelin-1; Female; Lung; Mice; Mice, Inbred BALB C; Neutrophils; Ovalbumin; Pulmonary Fibrosis; Respiratory Mucosa; Sulfur Dioxide; Transforming Growth Factor beta

Airway wall remodelling and inflammation are features of chronic asthma. Transforming growth factor beta (TGF-beta) has been implicated in these processes.. To determine the effect of allergen challenge on airway inflammation and remodelling and whether TGF-beta isoforms and the Smad signalling pathways are involved.. Thirteen patients with atopic asthma underwent inhalational challenge with 0.9% saline, followed by allergen 3-4 weeks later. After both challenges, fibreoptic bronchoscopy was undertaken to obtain bronchial biopsies and tissue samples were processed for immunohistochemistry and examined by microscopy.. Forced expiratory volume in 1 s (FEV(1)) fell after allergen challenge (mean (SE) -28.1 (0.9)% at 30 min with a late response at 7 hours (-23.0 (1.2)%). Allergen challenge caused an increase in neutrophils and eosinophils in the bronchial mucosa compared with saline. Sub-basement membrane (SBM) thickness did not change after allergen, but tenascin deposition in SBM was increased. Intranuclear (activated) Smad 2/3 and Smad 4 detected by immunohistochemistry were increased after allergen challenge in epithelial and subepithelial cells of bronchial biopsies. No inhibitory Smad (Smad 7) protein was detected. TGF-beta isoforms 1, 2 and 3 were expressed predominantly in bronchial epithelium after saline and allergen challenges, but only TGF-beta(2) expression was increased after allergen. Double immunostaining showed an increase in TGF-beta(2) positive eosinophils and neutrophils but not in TGF-beta(1) positive eosinophils and neutrophils after allergen challenge.. TGF-beta(2) may contribute to the remodelling changes in allergic asthma following single allergen exposure.

Topics: Adult; Allergens; Asthma; Biopsy; Bronchi; Bronchitis; Bronchoscopy; Chronic Disease; Eosinophils; Fiber Optic Technology; Forced Expiratory Volume; Humans; Neutrophils; Respiratory Mucosa; Transforming Growth Factor beta

At present there are conflicting results from studies investigating the role of corticosteroids in inhibiting airway remodeling in asthma. We have used a mouse model to determine whether administration of corticosteroids prevents the development of allergen-induced structural features of airway remodeling. Mice treated with corticosteroids were subjected to repetitive ovalbumin (OVA) challenge for 3 mo, at which time levels of peribronchial fibrosis and the thickness of the peribronchial smooth muscle layer were assessed by immunohistology, levels of transforming growth factor (TGF)-beta1 by ELISA, and the number of alpha-smooth muscle actin+/Col-1+ peribronchial myofibroblasts by immunohistochemistry. Corticosteroids significantly reduced allergen-induced increases in peribronchial collagen deposition and levels of total lung collagen but did not reduce allergen-induced increases in the thickness of the peribronchial smooth muscle layer. Levels of lung TGF-beta1 were significantly reduced in mice treated with systemic corticosteroids, and this was associated with a significant decrease in the number of peribronchial inflammatory cells that expressed TGF-beta1, including eosinophils and mononuclear cells. Corticosteroids also significantly reduced the number of peribronchial myofibroblasts. Overall, these studies demonstrate that administration of corticosteroids significantly reduces levels of allergen-induced peribronchial fibrosis. The reduction in peribronchial fibrosis mediated by corticosteroids is likely to be due to several mechanisms including inhibition of expression of TGF-beta1, a reduction in the number of peribronchial inflammatory cells expressing TGF-beta1 (eosinophils, macrophages), as well as by corticosteroids reducing the accumulation of peribronchial myofibroblasts that contribute to collagen expression.

Topics: Actins; Adrenal Cortex Hormones; Animals; Bronchi; Bronchitis; Collagen; Fibroblasts; Fibronectins; Hypersensitivity; Immunologic Techniques; Lung; Mice; Mice, Inbred BALB C; Mucus; Muscle, Smooth; Myocytes, Smooth Muscle; Ovalbumin; Staining and Labeling; Transforming Growth Factor beta; Transforming Growth Factor beta1

To study the relationship between the expression of transforming growth factor-beta(1) (TGF-beta(1)) and platelet derived growth factor (PDGF) and airway remodeling in eosinophilic bronchitis (EB).. Bronchial biopsy specimens were obtained from 12 patients with EB (A group), 10 asthmatic patients (B group) and 10 patients (C group) with peripheral lung cancer in early stage. The subepithelial basement membrane (SBM) thickness was measured by light microscopy using HE staining. The expressions of TGF-beta(1) and PDGF in the bronchial mucosa were examined by immunostaining.. The SBM of A group [(6.3 +/- 1.4) micro m] was significantly thicker than that of C group [(4.1 +/- 1.2) micro m, P < 0.05], but significantly thinner than that of B group [(8.2 +/- 1.5) micro m]. The numbers of positive cells for TGF-beta(1) and PDGF in A group (59 +/- 9, 47 +/- 7 respectively) and B group (85 +/- 12, 76 +/- 11, respectively) were significantly higher than those in C group (31 +/- 4, 20 +/- 3, respectively), and were positively correlated with SBM thickness (r = 0.76, 0.52, P < 0.05).. These results suggest that TGF-beta(1) and PDGF expressions in bronchial mucosa may play a role in bronchial subepithelial fibrosis in EB patients.

Topics: Adult; Bronchitis; Humans; Immunohistochemistry; Lung; Male; Middle Aged; Platelet-Derived Growth Factor; Pulmonary Eosinophilia; Respiratory Mucosa; Transforming Growth Factor beta

Changes in the levels of transforming growth factor (TGF)-beta cytokines or receptors observed during the progression of several inflammatory and fibrotic disorders have been used to implicate these cytokines in the pathophysiology of these diseases. Although correlative, these studies were inconclusive because they were unable to demonstrate actual continuous TGF-beta-mediated signaling in the involved tissues. We reasoned that the phosphorylation state and subcellular localization of Smad2, the intracellular effector of TGF-beta/activin-mediated signaling, could be used as a marker of active signaling mediated by these cytokines in situ. We therefore used an experimental model of ovalbumin-induced allergic airway inflammation and were able to demonstrate a dramatic increase in the numbers of bronchial epithelial, alveolar, and infiltrating inflammatory cells expressing nuclear phosphorylated Smad2 within the allergen-challenged lungs. This was accompanied by strong upregulation of the activin receptor ALK-4/ActR-IB and redistribution of the TGF-beta responsive ALK-5/TbetaR-I. Although levels of TGF-beta1, TGF-beta2, and TGF-beta3 messenger RNA (mRNA) were marginally altered, the level of activin mRNA was strongly upregulated during the inflammatory response. Our data illustrate the usefulness of antiphosphorylated Smad antibodies in demonstrating active TGF- beta/activin-mediated signaling in vivo and strongly suggest that activin/Smad-mediated signaling could be a critical contributor in the pathophysiology of allergic pulmonary diseases.

Topics: Activins; Animals; Base Sequence; Blotting, Western; Bronchitis; DNA Primers; DNA-Binding Proteins; Female; Hypersensitivity; Immunohistochemistry; Inhibins; Mice; Mice, Inbred BALB C; Phosphorylation; Protein Transport; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Smad2 Protein; Trans-Activators; Transforming Growth Factor beta

Obliterative bronchiolitis (OB), the most important long-term complication after lung transplantation, is thought to be a manifestation of chronic rejection within the airways, with the hallmarks inflammation and fibroproliferation.. To characterize the inflammatory process in the context of OB we quantified tumor necrosis factor-alpha, interleukin (IL)-8, IL-10, and transforming growth factor (TGF)-beta on the protein and mRNA level in bronchoalveolar lavage fluid samples obtained from patients with bronchiolitis obliterans syndrome (BOS) and without BOS. In addition, bronchial cells sampled by bronchial brushing were analyzed for mRNA expression.. In respiratory epithelial lining fluid (ELF) from BOS patients the protein levels of IL-8 (52.4+/-22.2 vs. 4.4+/-0.9 pg/ml ELF, P<0.005) and TGF-beta (5.6+/-1.9 vs. 0.9+/-0.2 ng/ml ELF, P<0.005) were significantly elevated. In addition, bronchoalveolar lavage fluid cells of BOS patients showed increased expression of TGF-beta (1.13+/-0.44 vs. 0.45+/-0.16, optical density [O.D.]/O.D. glyceraldehyde-3-phosphate dehydrogenase [GAPDH], P=0.11) and IL-8 (0.25+/-0.13 vs. 0.09+/-0.03 O.D/O.D. GAPDH, P=0.53) without the differences reaching statistical significance. In contrast, IL-8 mRNA expression of bronchial cells was significantly higher in the BOS group (0.85+/-0.40 vs. 0.22+/-0.10 O.D./O.D. GAPDH, P<0.05).. We assume that IL-8 and TGF-beta may act as key mediators for airway inflammation and fibroproliferation in the pathogenesis of OB, with bronchial epithelial cells serving as a relevant source of IL-8.

Topics: Adult; Bronchiolitis Obliterans; Bronchitis; Bronchoalveolar Lavage Fluid; Cell Count; Cell Survival; Cytokines; Eosinophils; Heart-Lung Transplantation; Humans; Inflammation Mediators; Interleukin-8; Lymphocytes; Macrophages; Male; Middle Aged; Neutrophils; RNA, Messenger; Transforming Growth Factor beta

Chronic airway inflammation and remodeling, including fibrosis, have been proposed as important contributors to asthma pathophysiology. Previous studies of airway fibrosis have been performed mainly in mild and moderate asthmatics at the subepithelial "basement membrane" (SBM) level. The current study was designed to evaluate the large airway SBM thickness and submucosal collagen deposition, as measured by three different collagen staining methods, in endobronchial biopsies from 17 severe, nine moderate, and seven mild asthmatics, as well as eight normal control subjects. Tissue eosinophils and transforming growth factor-beta (TGF-beta) immunoreactivity were also examined. There were no statistically significant differences in the SBM thickness, submucosal collagen deposition, eosinophil numbers, or TGF-beta positive cells among the three groups of asthmatics and the normal control subjects. It was only when examining all asthmatics (n = 33) together, that a modestly thickened SBM (p = 0.04), as evaluated by collagen type III immunostaining, was observed as compared with normal control subjects. Despite this difference, no significant differences were found in the amount of submucosal collagen deposition and the number of eosinophils or TGF-beta expressing cells when comparing total asthmatics and normal control subjects. Additionally, no significant correlations were found between collagen deposition and eosinophil count, TGF-beta expression level, FEV1, or duration of asthma. These results suggest that although increased collagen deposition in the SBM at the large airway level is a characteristic of asthma, it may not explain the differences in severity of asthma.

Topics: Adult; Asthma; Azo Compounds; Basement Membrane; Biopsy; Bronchi; Bronchitis; Bronchoscopy; Collagen; Coloring Agents; Eosinophils; Female; Fibrosis; Forced Expiratory Volume; Humans; Leukocyte Count; Lissamine Green Dyes; Male; Middle Aged; Mucous Membrane; Time Factors; Transforming Growth Factor beta

We assessed whether transforming growth factor-beta (TGF-beta), a fibrogenic growth factor, may be involved in remodeling of asthma and chronic bronchitis; its expression was compared with that of epidermal growth factor (EGF) and granulocyte macrophage colony-stimulating factor (GM-CSF) in bronchial mucosal biopsies from 13 normal subjects, 24 asthmatics, and 19 patients with chronic bronchitis. TGF-beta immunoreactivity was highly increased in epithelium and submucosa of those with bronchitis and to a lesser extent in asthmatics. By comparison, with normal subjects, EGF immunoreactivity was significantly increased in the epithelium of bronchitic subjects and submucosa of asthmatics, and, GM-CSF immunoreactivity was increased in both epithelial and submucosal cells of asthmatics and to a lesser extent in submucosa of bronchitics. A significant correlation was found between the number of epithelial or submucosal cells expressing TGF-beta in both asthma and chronic bronchitis and basement membrane thickness and fibroblast number. No such correlation was found for EGF or GM-CSF. in situ hybridization for TGF-beta 1 mRNA confirmed the results obtained by immunohistochemistry. By combining in situ hybridization and immunohistochemistry, it was found that eosinophils and fibroblasts were synthetizing TGF-beta in asthma and bronchitis. These data suggest that TGF-beta, but not EGF or GM-CSF, is involved in airways remodeling in asthma and chronic bronchitis.

Topics: Adolescent; Adult; Aged; Asthma; Biopsy; Bronchi; Bronchitis; Chronic Disease; Epidermal Growth Factor; Epithelium; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Immunohistochemistry; In Situ Hybridization; Middle Aged; Mucous Membrane; Transforming Growth Factor beta

Asthma and chronic bronchitis are associated with airway remodelling, and airway macrophages are present in bronchial inflammation. TGF-beta and fibronectin released by alveolar macrophages possess a fibrogenic potency. The potential role of alveolar macrophages in airway remodelling was studied in asthma and chronic bronchitis by the release of TGF-beta and fibronectin. Alveolar macrophages were isolated by bronchoalveolar lavage in 14 control subjects, 14 asthmatics and 14 chronic bronchitics. The spontaneous and lipopolysaccharide (LPS)- or concanavalin A (Con A)-induced release of TGF-beta and fibronectin was measured by ELISA. Alveolar macrophages from chronic bronchitics spontaneously release greater amounts of TGF-beta and fibronectin than those from asthmatic and control subjects. Alveolar macrophages from asthmatics release greater amounts of TGF-beta and fibronectin than those from control subjects. The spontaneous release of TGF-beta is significantly correlated with that of fibronectin. Fibronectin release was significantly reduced after LPS stimulation, and TGF-beta release was significantly increased after LPS stimulation, except in chronic bronchitis patients. Con A increased the release of TGF-beta in cells from normal subjects. This study suggests that activated macrophages play a role in airway remodelling in chronic bronchitis and to a lesser extent in asthma.

Topics: Adult; Asthma; Bronchitis; Chronic Disease; Concanavalin A; Female; Fibronectins; Humans; Lipopolysaccharides; Macrophages, Alveolar; Male; Middle Aged; Transforming Growth Factor beta