Project description:The apical junctional complex (AJC), composed of tight junctions and adherens junctions, is essential for maintaining epithelial barrier function. Since cigarette smoking and chronic obstructive pulmonary disease (COPD), the major smoking-induced disease, are both associated with increased lung epithelial permeability, we hypothesized that smoking alters the transcriptional program regulating AJC integrity in the small airway epithelium (SAE), the primary site of pathological changes in COPD. Transcriptome analysis revealed a global down-regulation of physiological AJC gene expression in the SAE of healthy smokers (n=53) compared to healthy nonsmokers (n=59), an observation associated with changes in molecular pathways regulating epithelial differentiation such as PTEN signaling and accompanied by induction of cancer-related AJC genes. Genome-wide co-expression analysis identified a smoking-sensitive AJC transcriptional network. The overall expression of AJC-associated genes was further decreased in COPD smokers (n=23). Exposure of human airway epithelial cells to cigarette smoke extract in vitro resulted in down-regulation of several AJC-related genes, accompanied by decreased transepithelial resistance. Thus, cigarette smoking alters the AJC gene expression architecture in the human airway epithelium, providing a molecular basis for the dysregulation of airway epithelial barrier function during the development of smoking-induced lung disease. The apical junctional complex (AJC), composed of tight junctions and adherens junctions, is essential for maintaining epithelial barrier function. Since cigarette smoking and chronic obstructive pulmonary disease (COPD), the major smoking-induced disease, are both associated with increased lung epithelial permeability, we hypothesized that smoking alters the transcriptional program regulating AJC integrity in the small airway epithelium (SAE), the primary site of pathological changes in COPD. In this study, microarray analysis of the SAE obtained from 53 healthy nonsmokers, 59 healthy smokers, and 23 smokers with COPD was performed to determine physiological AJC gene expression architecture in the SAE and its modification by cigarette smoking and during the development of COPD.
Project description:Chronic obstructive pulmonary disease is a smoking-related disease that lacks effective therapies due partly to the poor understanding of disease pathogenesis. The aim of this study was to identify molecular pathways which could be responsible for the damaging consequences of smoking. To do this, we employed recently described bioinformatic methods to analyze differences in global gene expression, which we then related to the pathological changes induced by cigarette smoke (CS). Sprague-Dawley rats were exposed to whole-body CS for 1 day and for various periods up to 8 months. Experiment Overall Design: Timecourse with 12 timepoints with 8 replicates at each time point.
Project description:Chronic obstructive pulmonary disease is a smoking-related disease that lacks effective therapies due partly to the poor understanding of disease pathogenesis. The aim of this study was to identify molecular pathways which could be responsible for the damaging consequences of smoking. To do this, we employed recently described bioinformatic methods to analyze differences in global gene expression, which we then related to the pathological changes induced by cigarette smoke (CS). Sprague-Dawley rats were exposed to whole-body CS for 1 day and for various periods up to 8 months. Keywords: Timecourse
Project description:Rationale: Chronic Obstructive Pulmonary Disease (COPD) is associated with a complex pulmonary and systemic immune response. Objective: To characterize and relate the lung tissue and circulating blood network immune response in COPD. Methods: Lung tissue and circulating blood samples were simultaneously obtained from COPD patients (current smokers n=28 and former smokers n=16) and controls (current smokers n=9 and non-smokers n=12) undergoing thoracic surgery. We used flow cytometry to assess the immune cell composition, Affymetrix arrays to determine whole lung mRNA expression, and Weighted Gene Co-expression Network Analysis (WGCNA) to characterize and compare the pulmonary and systemic immune responses in patients and controls. Results: In lung tissue of current smokers with COPD (vs. non-smokers and former smokers with COPD) we observed a significant increase in the proportion of intermediated phenotype macrophages (Mphage) expressing both M1 and M2 markers, whereas that of M1 Mphage (pro-inflammatory) and CD4+ and CD8+ T-lymphocytes were decreased. These changes were not mirrored in circulating blood but WGCNA identified three modules of co-expressed genes that related, respectively to: (1) the total proportion of lung Mphage (extracellular matrix and angiogenesis genes) ; (2) active smoking (T cell and apoptosis related genes); and, (3) severity of airflow limitation (cilium organization genes). Conclusions: In mild/moderate COPD, the main pulmonary immune cell alterations relate to current smoking, involve changes in the proportion of Mphage and T cells and are associated with changes in whole lung tissue transcriptome. These cellular pulmonary changes are not mirrored in the systemic circulation.
Project description:Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease leading to irreversible airflow limitation and is characterized by chronic pulmonary inflammation,obstructive bronchiolitis and emphysema. Etiologically, COPD is mediated by toxic gases and particles, e.g. cigarette smoke, while the pathogenesis of the disease is largely unknown. Several lines of evidence indicate a link between COPD and autoimmunity but comprehensive studies are lacking. By using a protein microarray assaying more than 19,000 human proteins we determined in this study the autoantibody profiles of COPD and non-COPD smokers.
Project description:Lymphotoxin β-receptor-signalling orchestrates lymphoid neogenesis and subsequent tertiary lymphoid structures (TLS) associated with severe chronic inflammatory diseases spanning multiple organ systems. How LTβR-signalling drives chronic tissue damage particularly in the lung, which mechanism(s) regulate this process, and whether LTβR-blockade might be of therapeutic value has remained unclear. Here we demonstrate increased lymphotoxin expression of LTbR-ligands on myeloid and adaptive and innate immune-cells, enhanced non-canonical NF-κB signalling and enrichment of LTβR-target gene expression in epithelial cells of lungs from patients and mice with smoking-associated chronic obstructive pulmonary disease (COPD). Accordingly, Therapeutic inhibition of LTβR-signalling in young and aged mice with COPD disrupted TLS, reverted lung tissue destruction, airway-fibrosis and systemic muscle wasting. Mechanistically, we identified that LTβR-signalling blockade leads to diminished cell-death, concomitantly reactivated endogenous Wnt/β-catenin-signalling in alveolar epithelial cells and reduced TGFβ-signalling in airways. These findings highlight LTβR as a viable therapeutic target against TLS induced tissue damage that translates into novel anti-inflammatory, regenerative strategies to treat COPD.
Project description:Background: When exposed to specific stimuli, macrophages exhibit distinct activation programs, M1 and M2 polarization, that define macrophage function as inflammatory/immune effectors or anti-inflammatory/tissue remodeling cells, respectively. Due to their position on the lung epithelial surface, alveolar macrophages (AM) directly interact with environmental stimuli such as cigarette smoke, the major risk factor for the development of chronic obstructive pulmonary disease (COPD). Based on the current paradigm that, in response to smoking, AM contribute to both inflammatory and tissue remodeling processes in the lung relevant to the pathogenesis of COPD, we hypothesized that chronic exposure to cigarette smoking activates both the M1 and M2 polarization programs in AM. Methods and Findings: To assess this hypothesis, global transcriptional profiling with TaqMan confirmation and flow cytometry analysis was carried out on AM obtained by bronchoalveolar lavage of 24 healthy nonsmokers, 34 healthy smokers and 12 smokers with COPD to assess the expression of 41 M1 genes and 32 M2 genes in each group. Contrary to our expectations, while there was up-regulation of some genes typical for M2-related phenotypes, AM of healthy smokers exhibited substantial suppression of M1-related inflammatory/immune genes. These M1- and M2-related changes progressed with the development of smoking-induced lung disease, with AM of smokers with COPD exhibiting further down-regulation of M1-related genes accompanied with further up-regulation of some M2-related genes. Conclusion: The data demonstrates that the modifications of the AM transcriptome associated with smoking result in a unique phenotype characterized by reprogramming of AM towards M1-deactivated partially M2-polarized macrophages and suggests that, while AM likely contribute to smoking-induced tissue remodeling, the role of AM in the early pathogenesis of smoking-induced COPD in humans is not inflammatory. This concept is a departure from the conventional concept that AM-mediated inflammation participates in the early derangements of the lung induced by smoking, and suggests a novel paradigm for conceptualizing COPD and developing new approaches to prevent the development of smoking-induced lung disease. Comparison of gene expression in alveolar macrophages of normal non-smokers and normal smokers and smokers with COPD