Project description:Despite overwhelming data that cigarette smoking causes chronic obstructive pulmonary disease (COPD), only a minority of chronic smokers are affected, strongly suggesting that genetic factors modify susceptibility to this disease. We hypothesized that there are individual variations in the response to cigarette smoking, with variability among smokers in expression levels of protective / susceptibility genes. Affymetrix arrays and TaqMan PCR were used to assess the variability of gene expression in the small airway epithelium obtained by fiberoptic bronchoscopy of 18 normal non-smokers, 18 normal smokers and 18 smokers with COPD. We identified 201 probesets representing 150 smoking-responsive genes that were significantly up- or down-regulated, and assessed the coefficient of variation in expression levels among the study population. Variation was a reproducible property of each gene as assessed by different microarray probesets and realtime PCR and was observed in both normal smokers and smokers with COPD. There was greater individual variability in smokers with COPD than in normal smokers. The majority of these highly variable smoking responsive genes were in the functional categories of signal transduction, xenobiotic degradation, metabolism, transport, oxidant-related and transcription. A similar pattern of the same highly variable genes was observed in an independent data set.We propose that there is likely genetic diversity within this subset of genes with highly variable individual to individual responses of the small airway epithelium to smoking, and this subset of genes represent putative candidates for assessment of susceptibility/protection from disease for future gene-based epidemiological studies for the risk of smokers for COPD. Experiment Overall Design: Affymetrix arrays and TaqMan PCR were used to assess the variability of gene expression in the small airway epithelium obtained by fiberoptic bronchoscopy of 18 normal non-smokers, 18 normal smokers and 18 smokers with COPD.
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:Down-regulation of the Notch Differentiation Pathway in the Human Airway Epithelium in Normal Smokers and Smokers with Chronic Obstructive Lung Disease In cigarette smokers, the toxic components of smoke place the epithelium under the constant stress of a variety of mechanisms of injury, with consequent modulation of airway epithelial regeneration and disordered differentiation. Based on the underlying hypothesis that these airway epithelial changes must involve quantitative changes in genes involved with the regulation of differentiation, we assessed the expression of the Notch pathway, a signaling pathway known to play a fundamental role in the embryonic lung as a gatekeeper for differentiation, in the small airway epithelium of non-smokers, normal smokers, and smokers with COPD. Microarray analysis demonstrated that 45 of the 55 Notch pathway-related genes are expressed in the human adult small airway epithelium and TaqMan quantitative PCR confirmed the expression of key genes in the pathway. TaqMan quantitative PCR analysis of the normal small airway epithelium demonstrated that Delta-like ligand 1 is the most highly expressed Notch ligand, Notch2 and 3 the most highly expressed receptor genes, and Hes1 the predominant downstream effector gene. TaqMan PCR was used to compare gene expression in nonsmokers vs healthy smokers vs smokers with COPD. The data show that some key genes in the ligands, receptors and downstream effectors in the Notch pathway are differentially expressed in smokers, with significant downregulation of a greater number of Notch-related genes in smokers with COPD compared to healthy smokers. These observations are consistent with the hypothesis that the Notch pathway, known to play an important role in lung morphogenesis, also likely plays a role in the adult human airway epithelium, with at least some of the Notch pathway gene expression dysregulated in association with smoking and its related disorder, COPD. Keywords: non-smokers, airway epithelial cells
Project description:Upregulation of Expression of the Ubiquitin Carboxyl Terminal Hydrolase L1 Gene in Human Airway Epithelium of Cigarette Smokers; The microarray data deposited here is from 11 HG-U133A GeneChips, from 5 normal non-smokers and 6 phenotypic normal smokers, large airways. Samples from the small airways of these individuals have been obtained and analyzed using the HG-U133A GeneChip; the small airway samples are in GEO Accession Number GSE 3320, and the data analysis is described in Harvey, B-G; Heguy, A.; Leopold, P.L.; Carolan, B.; Ferris, B. and Crystal R.G. Modification of Gene Expression of the Small Airway Epithelium in Response to Cigarette Smoking. J. Mol. Med (in press). These data are part of a study aimed at understanding how cigarette smoking modifies neuroendocrine cells, in which microarray analysis with TaqMan confirmation was used to assess airway epithelial samples obtained by fiberoptic bronchoscopy from 81 individuals (normal nonsmokers, normal smokers, smokers with early COPD and smokers with established COPD). Of 11 genes considered to be neuroendocrine cell-specific, only ubiquitin C-terminal hydrolase L1(UCHL1), a member of the ubiquitin proteasome pathway, was consistently upregulated in smokers compared to nonsmokers. Up-regulation of UCHL1 at the protein level was observed with immunohistochemistry of bronchial biopsies of smokers compared to nonsmokers. Interestingly, however, while UCHL1 expression was present only in neuroendocrine cells of the airway epithelium in nonsmokers, UCHL1 expression was also expressed in ciliated epithelial cells in smokers, an intriguing observation in light of recent observations that ciliated cells can are capable of transdifferentiating to other airway epithelium. In the context that UCHL1 is involved in the degradation of unwanted, misfolded or damaged proteins within the cell and is overexpressed in >50% of lung cancers, its overexpression in chronic smokers may represent an early event in the complex transformation from normal epithelium to overt malignancy. Experiment Overall Design: comparison of gene expression in airway epithelial cells of the large airways of phenotypic normal smokers vs normal non-smokers
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:Upregulation of Expression of the Ubiquitin Carboxyl Terminal Hydrolase L1 Gene in Human Airway Epithelium of Cigarette Smokers; The microarray data deposited here is from 44 HuGeneFL GeneChips, from 9 normal non-smokers and 13 phenotypic normal smokers, large airways, 2 samples per individual, one from the right lung and one from the left lung. These samples were previously described in Hackett NR, Heguy A, Harvey BG, O'Connor TP, Luettich K, Flieder DB, Kaplan R, Crystal RG. Variability of antioxidant-related gene expression in the airway epithelium of cigarette smokers. Am J Respir Cell Mol Biol. 2003 29:331-43 and in Heguy A, Harvey BG, O'Connor TP, Hackett NR, Crystal RG. Sampling-dependent up-regulation of gene expression in sequential samples of human airway epithelial cells. Mol Med. 2003 9:200-8. These data are part of a study aimed at understanding how cigarette smoking modifies neuroendocrine cells, in which microarray analysis with TaqMan confirmation was used to assess airway epithelial samples obtained by fiberoptic bronchoscopy from 81 individuals (normal nonsmokers, normal smokers, smokers with early COPD and smokers with established COPD). Of 11 genes considered to be neuroendocrine cell-specific, only ubiquitin C-terminal hydrolase L1(UCHL1), a member of the ubiquitin proteasome pathway, was consistently upregulated in smokers compared to nonsmokers. Up-regulation of UCHL1 at the protein level was observed with immunohistochemistry of bronchial biopsies of smokers compared to nonsmokers. Interestingly, however, while UCHL1 expression was present only in neuroendocrine cells of the airway epithelium in nonsmokers, UCHL1 expression was also expressed in ciliated epithelial cells in smokers, an intriguing observation in light of recent observations that ciliated cells can are capable of transdifferentiating to other airway epithelium. In the context that UCHL1 is involved in the degradation of unwanted, misfolded or damaged proteins within the cell and is overexpressed in >50% of lung cancers, its overexpression in chronic smokers may represent an early event in the complex transformation from normal epithelium to overt malignancy. Experiment Overall Design: comparison of gene expression in airway epithelial cells of the large airways of phenotypic normal smokers vs normal non-smokers
Project description:Down-regulation of the Notch Differentiation Pathway in the Human Airway Epithelium in Normal Smokers and Smokers with Chronic Obstructive Lung Disease; In cigarette smokers, the toxic components of smoke place the epithelium under the constant stress of a variety of mechanisms of injury, with consequent modulation of airway epithelial regeneration and disordered differentiation. Based on the underlying hypothesis that these airway epithelial changes must involve quantitative changes in genes involved with the regulation of differentiation, we assessed the expression of the Notch pathway, a signaling pathway known to play a fundamental role in the embryonic lung as a gatekeeper for differentiation, in the small airway epithelium of non-smokers, normal smokers, and smokers with COPD. Microarray analysis demonstrated that 45 of the 55 Notch pathway-related genes are expressed in the human adult small airway epithelium and TaqMan quantitative PCR confirmed the expression of key genes in the pathway. TaqMan quantitative PCR analysis of the normal small airway epithelium demonstrated that Delta-like ligand 1 is the most highly expressed Notch ligand, Notch2 and 3 the most highly expressed receptor genes, and Hes1 the predominant downstream effector gene. TaqMan PCR was used to compare gene expression in nonsmokers vs healthy smokers vs smokers with COPD. The data show that some key genes in the ligands, receptors and downstream effectors in the Notch pathway are differentially expressed in smokers, with significant downregulation of a greater number of Notch-related genes in smokers with COPD compared to healthy smokers. These observations are consistent with the hypothesis that the Notch pathway, known to play an important role in lung morphogenesis, also likely plays a role in the adult human airway epithelium, with at least some of the Notch pathway gene expression dysregulated in association with smoking and its related disorder, COPD. Experiment Overall Design: Gene expression in airway epithelial cells of normal non-smokers.