Project description:Study Smoking and COPD are associated with decreased mucociliary clearance and healthy smokers have shorter cilia in the large airway than nonsmokers. Intraflagellar transport (IFT) is the process by which cilia are produced and maintained. We assessed expression of IFT-related genes in smokers and nonsmokers and evaluated cilia length in the large and small airway of nonsmokers, healthy smokers, and smokers with COPD. Methods Airway epithelium was obtained via bronchoscopic brushing. Affymetrix microarrays were used to evaluate IFT gene expression in 2 independent data sets from large and small airway. Cilia length was assessed by measuring 100 cilia (10 cilia on each of 10 cells) per subject. Results All 40 IFT genes were expressed in the human large and small airway epithelium. In the large airway, 10 IFT genes were down-regulated and 1 up-regulated in smokers. In the small airway, 11 genes were down-regulated and 3 up-regulated in smokers. A set of 8 IFT genes was down-regulated in both data sets. In the large and small airway epithelium, cilia were significantly shorter in healthy smokers than nonsmokers, and significantly shorter in COPD smokers than in both healthy smokers and nonsmokers. Answer to the Question These results support the concept that loss of cilia length contributes to defective mucociliary clearance in COPD, and that smoking-induced changes in expression of IFT genes may be one mechanism of abnormally short cilia in smokers. Strategies to normalize cilia length may be an important avenue for novel COPD therapies. Gene expression was assessed for 40 intraflagellar transport related genes in the LAE of nonsmokers (n=21) and healthy smokers (n=31) and the SAE of an independent group of nonsmokers (n=28) and healthy smokers (n=69). Cilia length was assessed in a total of 228 airway epithelium samples, including 120 LAE samples and 108 SAE samples; a subset of the 228 samples is represented among the 149 samples in this Series.

Project description:The toll-like receptors (TLRs) are important components of the respiratory epithelium host innate defense, enabling the airway surface to recognize and respond to a variety of insults in inhaled air. Based on the knowledge that smokers are more susceptible to pulmonary infection and the airway epithelium of smokers with chronic obstructive pulmonary disease (COPD) is characterized by bacterial colonization and acute exacerbation of airway infections, we assessed whether smoking alters the expression of TLRs in human small airway epithelium, the primary site of smoking-induced disease. Microarrays were used to survey the TLR family gene expression in small airway (10th-12th order) epithelium from healthy nonsmokers (n=60), healthy smokers (n=73) and smokers with COPD (n=36). Using the criteria of detection call of present in ≥50%, 6 of 10 TLRs (1, 2, 3, 4, 5 and 8) were expressed. Compared to nonsmokers, the most strikingly changed gene is TLR5, which down-regulated in healthy smokers (1.4-fold decrease, p<10-13) and in smokers with COPD (1.6-fold, p<10-14). TaqMan RT-PCR confirmed these observations. Bronchial biopsies immunofluorescence showed that TLR5 protein was expressed mainly on the apical side of the human airway epithelium and decreased in healthy smokers and smokers with COPD. In vitro studies showed that the level of TLR5 downstream genes, IL-6 and IL-8 were highly induced in TLR5 high-expressing cells compared to TLR5 low-expressing cells after flagellin exposure. In the context that TLR5 functions to recognize pathogens and activate innate immune responses, the smoking-induced down-regulation of TLR5 likely contributes to smoking-related susceptibility to airway infection. The toll-like receptors (TLRs) are important components of the respiratory epithelium host innate defense. Microarrays were used to survey the TLR family gene expression in small airway (10th-12th order) epithelium from healthy nonsmokers (n=60), healthy smokers (n=73) and smokers with COPD (n=36). Using the criteria of detection call of present in ≥50%, 6 of 10 TLRs (1, 2, 3, 4, 5 and 8) were expressed. Compared to nonsmokers, the most strikingly changed gene is TLR5, which down-regulated in healthy smokers (1.4-fold decrease, p<10-13) and in smokers with COPD (1.6-fold, p<10-14). In the context that TLR5 functions to recognize pathogens and activate innate immune responses, the smoking-induced down-regulation of TLR5 likely contributes to smoking-related susceptibility to airway infection. *** Processed data not provided for all gene expression records. ***

Project description:The aldokatoreductases (AKRs) represent a gene superfamily that code for monomeric, soluble NAD(P)H-dependent oxidoreductases that mediate elimination reactions. AKR1B10, an AKR that functions to eliminate retinals, has been observed to be upregulated in squamous metaplasma and non small cell lung cancer, and has been suggested as a diagnostic marker specific to tobacco-related carcinogenesis. In the context of the link of smoking and lung cancer and the enhanced expression of AKR1B10 expression in lung cancer, we hypothesize that enhanced expression of AKR1B10 may be initiated in healthy smokers, prior to the development of any evidence of lung cancer. For this purpose, expression of AKR1B10 was assessed at the mRNA level using microarrays in the large airway epithelium (21 healthy nonsmokers, 31 health smokers) and small airway epithelium (51 healthy nonsmokers, 58 healthy smokers) obtained by fiberoptic bronchoscopy and brushing, as well as assessment in a subset of this population by TaqMan PCR and in endobronchial biopsies by Western analysis and immunohistochemistry. Compared to healthy nonsmokers, ARK1B10 mRNA levels were markedly upregulated in both the large and small airway epithelium of healthy smokers (large airway microarray p<0.0001, small airway p<0.0001; TaqMan large airway, p<0.02, small airway p<0.01). Consistent with the mRNA data, AKR1B10 protein was significantly upregulated in the airway epithelium of healthy smokers as assessed by Western analysis and by immunohistochemistry, with AKR1B10 expressed in both differentiated and basal cells of the normal epithelium. Finally, cigarette smoke extract mediated up-regulation of AKR1B10 in airway epithelial cells in vitro. Thus, smoking per se mediates up-regulation of AKR1B10 expression in the airway epithelium of healthy smokers with no evidence of lung cancer. In the context of these observations, and the link of AKR1B10 to the metabolism of retinals and to lung cancer, the smoking-induced up-regulation of AKR1B10 may be an early process in the multiple events leading to the develop of lung cancer.

Project description:Lectins are proteins present on cell surfaces or as shed extracellular proteins that function in innate immune defense as phagocytic receptors to recognize specific bacterial cell wall components. Based on the knowledge that cigarette smoking is associated with increased risk of bacterial infection, we hypothesized that cigarette smoking may modulate the expression of lectin genes in the airway epithelium. Affymetrix HG U133 Plus 2.0 microarrays were used to survey expression of lectin genes in large (3rd to 4th order bronchi) airway epithelium from 9 normal nonsmokers and 20 phenotypic normal smokers and small (10th to 12th order bronchi) airway epithelium from 13 normal nonsmokers and 20 phenotypic normal smokers. From the 72 lectin genes that were surveyed, there were no changes (>2-fold change, p<0.05) in gene expression in either large or small airway epithelium among normal smokers compared to nonsmokers except for a striking down regulation in both large and small airway epithelium of normal smokers of intelectin 1, a recently described lectin that participates in the innate immune response by recognizing and binding to galactofuranosyl residues in the cell walls of bacteria (large airway epithelium, p<0.003; small airway epithelium, p<0.002). TaqMan RT-PCR confirmed the observation that intelectin 1 was down-regulated in both large (p<0.05) and small airway epithelium (p<0.02) of normal smokers compared to normal nonsmokers. Immunohistochemistry assessment of biopsies of the large airway epithelium of normal nonsmokers demonstrated intelectin 1 was expressed in secretory cells, with qualitatively decreased expression in biopsies from normal smokers. Western analysis confirmed the decreased expression of intelectin 1 in airway epithelium of normal smokers compared to normal nonsmokers (p<0.02). Finally, compared to normal nonsmokers, intelectin 1 expression was decreased in small airway epithelium of smokers with early COPD (n= 13, p<0.001) and smokers with established COPD (n= 14, p<0.001), in a fashion similar to that of normal smokers. In the context that intelectin 1 is an epithelial molecule that likely plays a role in defense against bacteria, the down regulation of expression of intelectin 1 in response to cigarette smoking may contribute to the increase in susceptibility to infections observed in smokers, including those with COPD. Keywords: COPD Comparison of gene expression in airway epithelial cells of normal non-smokers, phenotypic normal smokers, smokers with early COPD, and smokers with COPD.

Project description:Testican 3 (coded for by SPOCK3), is an extracellular matrix heparan/chondroitin sulphate proteoglycan that possesses serine and cysteine protease inhibitor-like domains Based on the knowledge that serine proteases contribute to the destruction of the lung in cigarette smokers, but that only a fraction of smokers develop smoking-induced lung disease, we hypothesized that smokers expressed SPOCK3 at lower levels in the small airway epithelium, the initial site of smoking-induced disease, and further, that genetic variability modulates the expression of SPOCK3 in the airway epithelium. Assessment of gene expression in the small airway epithelium (10th -12th order bronchi) of healthy non-smokers (n=38) and healthy smokers (n=42), demonstrated that the expression levels of SPOCK3 were significantly lower in healthy smokers compared to healthy nonsmokers (p<0.04). Affymetrix Human SNP array 5.0 was used to assess genome wide single nucleotide polymorphisms (SNPs) within 100 kbp of the SPOCK3 gene in the same nonsmokers and smokers, and these SNPs were correlated with small airway gene expression of SPOCK3, with correction for variation in genetic ancestry. There was a significant correlation of SPOCK3 small airway epithelial gene expression with 13 adjacent SNPs in the SPOCK3 gene (p<10-3, all comparisons, Wald test). For example, the TT allele of rs13124292, located in intron 3, was associated with a small airway epithelial expression levels of 0.56 ± 0.07, and the AA genotype with expression levels of 2.31 ± 0.26 (p<10-6, pairwise t test). Interestingly, smoking appeared to lessen the degree to which genotype associated with SPOCK3 expression level, i.e., smoking to some extent overrode the influence of genetic variation. The observation that SPOCK3 gene expression in the small airway epithelium is reduced in smokers, and that smoking interacts with cis-genomic variations to determine the levels of SPOCK3 small airway epithelial gene expression, is consistent with the concept that everyone is at risk for smoking-induced lung disease, but that inherited genetic variations contribute to the pathogenesis of susceptibility to smoking-induced disease.

Project description:Lectins are proteins present on cell surfaces or as shed extracellular proteins that function in innate immune defense as phagocytic receptors to recognize specific bacterial cell wall components. Based on the knowledge that cigarette smoking is associated with increased risk of bacterial infection, we hypothesized that cigarette smoking may modulate the expression of lectin genes in the airway epithelium. Affymetrix HG U133 Plus 2.0 microarrays were used to survey expression of lectin genes in large (3rd to 4th order bronchi) airway epithelium from 9 normal nonsmokers and 20 phenotypic normal smokers and small (10th to 12th order bronchi) airway epithelium from 13 normal nonsmokers and 20 phenotypic normal smokers. From the 72 lectin genes that were surveyed, there were no changes (>2-fold change, p<0.05) in gene expression in either large or small airway epithelium among normal smokers compared to nonsmokers except for a striking down regulation in both large and small airway epithelium of normal smokers of intelectin 1, a recently described lectin that participates in the innate immune response by recognizing and binding to galactofuranosyl residues in the cell walls of bacteria (large airway epithelium, p<0.003; small airway epithelium, p<0.002). TaqMan RT-PCR confirmed the observation that intelectin 1 was down-regulated in both large (p<0.05) and small airway epithelium (p<0.02) of normal smokers compared to normal nonsmokers. Immunohistochemistry assessment of biopsies of the large airway epithelium of normal nonsmokers demonstrated intelectin 1 was expressed in secretory cells, with qualitatively decreased expression in biopsies from normal smokers. Western analysis confirmed the decreased expression of intelectin 1 in airway epithelium of normal smokers compared to normal nonsmokers (p<0.02). Finally, compared to normal nonsmokers, intelectin 1 expression was decreased in small airway epithelium of smokers with early COPD (n= 13, p<0.001) and smokers with established COPD (n= 14, p<0.001), in a fashion similar to that of normal smokers. In the context that intelectin 1 is an epithelial molecule that likely plays a role in defense against bacteria, the down regulation of expression of intelectin 1 in response to cigarette smoking may contribute to the increase in susceptibility to infections observed in smokers, including those with COPD. Keywords: COPD

Project description:Nuclear factor erythroid 2-related factor 2 (NFE2L2, Nrf2) is an oxidant responsive transcription factor known to induce phase 2 detoxifying and antioxidant genes to protect cells from oxidative stress. Cigarette smoke, with its large oxidant content, is a major stressor to the small airway epithelium, the cells of which are vulnerable to oxidant damage and consequent malignant transformation. In this study, we assessed the role of cigarette smoke in activation of Nrf2 in the human small airway epithelium in vivo. Fiberoptic bronchoscopy was used to sample a pure population of small airway epithelium in 38 healthy nonsmokers and 45 healthy smokers, and gene expression was assessed using Affymetrix HG-U133 Plus 2.0 microarrays. Compared to that of healthy nonsmokers, Nrf2 protein was significantly activated in the small airway epithelium of healthy normal smokers and localized in the nucleus (p<0.05). Of the human homologs of 201 known murine Nrf2-mediated genes, 13 highly smoking-responsive genes were identified (p<10-4, all comparisons smokers to nonsmokers). Using a “Nrf2-index” to quantify the extent of expression in the small airway epithelium of these 13 known Nrf2 genes, variability in the level of expression was observed among the 45 healthy smokers, but the variability was coordinately modulated among the 13 genes, an observation confirmed by TaqMan quantitative PCR. This variability in the coordinate level of expression of the 13 Nrf2-mediated genes was independent of the smoking history. Based on these observations, the “Nrf2 index” was used to evaluate whether other genes modulated by smoking in the small airway epithelium were also coordinately up- or down- modulated among the 45 healthy smokers. Two genes, pirin (PIR) and UDP glucuronosyltransferase 1 family polypeptide A4 (UGT1A4), not previously known to be modulated by Nrf2 were identified as being coordinately modulated among the 45 smokers. Both genes contain several functional antioxidant response elements in the promoter region. Using an electrophoretic mobility shift assay, these antioxidant response elements in the promoters of PIR and UGT1A4 responded in vitro to activated Nrf2. These observations are consistent with the concept that Nrf2 plays an important role in regulating cellular defenses against smoking in the highly vulnerable small airway epithelium cell population, and that there is variability among the population in the relative Nrf2 responsiveness to a similar oxidant burden. Affymetrix arrays were used to assess gene expression data in small airway epithelium obtained by fiberoptic bronchoscopy of 38 healthy non-smokers and 45 healthy smokers

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Trachea Epithelium as a “ Canary” for Cigarette Smoking-induced Biologic Phenotype of Small Airway Epithelium

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