Molecular Mapping of Keratinocyte Differentiation by Functional Gene Expression Profiling
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Yoga Balagurunathan
PROVIDER: E-GEOD-26688 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Microarray technology provides a powerful tool for defining gene expression profiles of airway epithelium that lend insight into the pathogenesis of human airway disorders. The focus of this study was to establish rigorous quality control parameters to ensure that microarray assessment of the airway epithelium is not confounded by experimental artifact. Samples (total n=223) of trachea, large and small airway epithelium were collected by fiberoptic bronchoscopy of 144 individuals (42 healthy non-smokers, 49 healthy smokers, 11 symptomatic smokers, 22 smokers with lone emphysema with normal spirometry, and 20 smokers with COPD) were processed and hybridized to Affymetrix HG-U133 2.0 Plus microarrays. The pre- and post-chip quality control (QC) criteria established, included: (1) RNA quality, assessed by RNA Integrity Number (RIN) ≥7.0 using Agilent 2100 Bioanalyzer software; (2) cRNA transcript integrity, assessed by signal intensity ratio of GAPDH 3' to 5' probe sets ≤3.0; and (3) the multi-chip normalization scaling factor ≤10.0 Of the 223 samples, 213 (95.5%) passed the QC criteria. In a data set of 34 arrays (10 samples failing QC criteria, 24 randomly chosen samples passing QC criteria), correlation coefficients for pairwise comparisons of expression levels for 100 housekeeping genes in which at least one array failed the QC criteria were significantly lower (average Pearson r = 0.90 ± 0.04) and more broadly dispersed than correlation coefficients for pairwise comparisons between any two arrays that passed the QC criteria (average Pearson r = 0.97 ± 0.01). By using the QC cutoff criteria, the inter-array variability, as assessed by the coefficient of variation in the expression levels for 100 housekeeping genes, was reduced from 35.7% to 21.7%. Based on the aberrant housekeeping gene data generated from samples failing the established QC criteria, we propose that the QC criteria outlined in this study can accurately distinguish high quality from low quality data and can be used to delete poor quality microarray samples before proceeding to higher-order biological analyses and interpretation. Affymetrix arrays were used to assess the quality of gene expression data in trachea, large airway and small airway epithelium obtained by fiberoptic bronchoscopy of 42 healthy non-smokers, 49 healthy smokers, 11 symptomatic smokers, 22 smokers with lone emphysema with normal spirometry, and 20 smokers with COPD.
2010-09-19 | E-GEOD-11906 | biostudies-arrayexpress
Project description:Smokers weigh less and have less body fat than non-smokers, and increased body fat and weight gain are observed following smoking cessation. To assess a possible molecular mechanism underlying the inverse association between smoking and body weight, we hypothesized that smoking may induce the expression of a fat depleting gene in the airway epithelium, the cell population that takes the brunt of the stress of cigarette smoke. As a candidate gene we evaluated the expression of alpha2-zinc-glycoprotein1 (AZGP1), a soluble protein that stimulates lipolysis, induces a reduction in body fat in mice and is associated with the cachexia related to cancer, and is known to be expressed in secretory cells of lung epithelium. To assess if smoking upregulates AZGP1 expression, microarray analysis with TaqMan confirmation was used to evaluate large airway epithelial samples obtained by fiberoptic bronchoscopy from 37 normal smokers and 55 normal nonsmokers. Both microarray and TaqMan analysis demonstrated that AZGP1 mRNA levels were higher in the large airway epithelium of normal smokers compared to normal nonsmokers (p<0.05, all comparisons). Western analysis of airway biopsies of smokers compared with nonsmokers demonstrated upregulation of AZGP1 at the protein level, and immunohistochemical analysis demonstrated upregulation of AZGP1 in secretory as well as neuroendocrine cells of smokers. In the context that AZGP1 is involved in lipolysis and fat loss, its overexpression in the airway epithelium of chronic smokers may represent one mechanism for the weight difference in smokers vs nonsmokers. Keywords: Comparison of gene expression in large airway epithleium of normal non-smokers and normal smokers Airway epithelial cells obtained by bronchoscopy with brushing from healthy smokers and healthy non-smokers
2009-01-06 | E-GEOD-10135 | biostudies-arrayexpress
Project description:Activation of the human embryonic stem cell (hESC)-signature genes has been observed in various epithelial cancers. In this study, we found that the hESC signature is selectively induced in the airway basal stem/progenitor cell population of healthy smokers (BC-S), with a pat-tern similar to that activated in all major types of human lung cancer. We further identified a subset of 6 BC-S hESC genes, whose coherent overexpression in lung AdCa was associated with reduced lung function, poorer differentiation grade, more advanced tumor stage, remarkably shorter survival and higher frequency of TP53 mutations. BC-S shared with hESC and a consid-erable subset of lung carcinomas a common TP53 inactivation molecular pattern which strongly correlated with the BC-S hESC gene expression. These data provide transcriptome-based evi-dence that smoking-induced reprogramming of airway BC towards the hESC-like phenotype might represent a common early molecular event in the development of aggressive lung carci-nomas in humans. Affymetrix arrays were used to assess gene expression data of genes realted to human embryonic stem cells in large airway epithelium obtained by fiberoptic bronchoscopy of 21 healthy non-smokers and 31 healthy smokers, basal cell culture of large airway epithelium obtained by fiberoptic bronchoscopy of 4 healthy nonsmokers and 4 healthy smokers and cells obtained from tumor tissues of 4 individuals.
2014-09-09 | E-GEOD-19722 | biostudies-arrayexpress
Project description:Our goal was to establish a robust and reliable platform for the mapping of gene expression changes occurring during the process of keratinocyte differentiation. We hypothesized that a functional gene expression profiling approach capable of identifying the program of gene expression over time would facilitate more focused identification of relevant genes. To achieve this, we used the confluenceinduced differentiation (CID) model, a widely used and reliable method that in many aspects recapitulates in vivo differentiation of human epidermal keratinocytes (Paragh et al, 2010; Poumay and Pittelkow, 1995).
2013-12-15 | GSE26688 | GEO
Project description:The Wnt pathway plays a central role in controlling differentiation of epithelial tissues; when Wnt is on, differentiation is suppressed, but when Wnt is off, differentiation is allowed to proceed. Based on this concept, we hypothesized that expression of key genes in the Wnt pathway are suppressed in the human airway epithelium under the stress of cigarette smoking, a stress associated with dysregulation of the differentiated state of the airway epithelium. For this purpose, HG-U133 Plus 2.0 microarrays were used to assess the expression of Wnt-related genes in the small airway (10th-12th generation) epithelium (SAE) obtained via bronchoscopy and brushing of healthy nonsmokers (n=47), healthy smokers (n=58), and smokers with established COPD (n=22). With expression defined as present in >20% of samples, microarray analysis demonstrated that 35 of 57 known Wnt-related genes are expressed in the adult SAE. Wnt pathway downstream targets β-catenin (p<0.05) and the transcription factor 7-like 1 were down-regulated in healthy smokers, and smokers with COPD, as were a number of Wnt target genes, including VEGFA, CCND1, MMP7, CLDN1, SOX9, RHOU (all p<0.05 compared to healthy nonsmokers). As a mechanism to explain this broad, smoking-induced suppression of the Wnt pathway, we assessed expression of the DKK and SFRP families, extracellular regulators that suppress the Wnt pathway. Among these, secreted frizzled-related protein 2 (SFRP2), was up-regulated 4.3-fold (p<0.0001) in healthy smokers and 4.9-fold (p<0.0001) in COPD smokers, an observation confirmed by TaqMan Real-time PCR. AT the protein levels, Western analysis demonstrated SFRP2 up-regulation, and immunohistochemistry demonstrated that the smoking-induced SFRP2 upregulation occurred in differentiated ciliated cells. Finally, cigarette smoke extract mediated up-regulation of SFRP2 and downregulation of Wnt target genes in airway epithelial cells in vitro. These observations are consistent with the hypothesis that the Wnt pathway plays a role in airway epithelial cell differentiation in the adult human airway epithelium, with smoking associated with down-regulation of Wnt pathway, contributing to the dysregulation of airway epithelial differentiation observed in the smoking-related airway disorders. Affymetrix arrays were used to assess gene expression data of genes in the Wnt pathway in small airway epithelium obtained by fiberoptic bronchoscopy of 47 healthy non-smokers and 58 healthy smokers and 22 smokers with COPD.
2011-04-20 | E-GEOD-19407 | biostudies-arrayexpress
Project description:Background: Whereas cilia damage and reduced cilia beat frequency have been implicated as causative of reduced mucociliary clearance in smokers, theoretically mucociliary clearance could also be affected by cilia length. Based on models of mucociliary clearance predicting cilia length must exceed the 6 -7 μm airway surface fluid depth to generate force in the mucus layer, we hypothesized cilia height may be decreased in airway epithelium of normal smokers compared to nonsmokers. Methodology/Principal Findings: Cilia length in normal nonsmokers and smokers was evaluated in aldehyde-fixed, paraffin-embedded endobronchial biopsies, and air-dried and hydrated samples brushed from human airway epithelium via fiberoptic bronchoscopy. In 28 endobronchial biopsies, healthy smoker cilia length was reduced 15% compared to nonsmokers (p<0.05). In 47 air-dried samples of airway epithelial cells, smoker cilia length was reduced 13% compared to nonsmokers (p<0.0001). Analysis of the length of individual, detached cilia in 17 samples, smoker cilia length was reduced 9% compared to nonsmokers (p<0.05). Finally, in 16 fully hydrated, unfixed samples, smoker cilia length was reduced 7% compared to nonsmokers (p<0.05). Conclusions/significance: Models predict that a reduction in cilia length would reduce mucociliary clearance, suggesting that smoking-associated shorter airway epithelial cilia plays a significant role in the pathogenesis of smoking-induced lung disease.
2012-12-13 | E-GEOD-16696 | biostudies-arrayexpress
Project description:Human airway epithelial cells cultured in vitro at air-liquid interface (ALI) form a pseudostratified epithelium that forms tight junctions and cilia, and produces mucin, and are widely used as a model of differentiation, injury, and repair. To assess how closely the transcriptome of ALI epithelium matches that of in vivo airway epithelial cells, we used microarrays to compare the transcriptome of human large airway epithelial cells cultured at ALI with the transcriptome of large airway epithelium obtained via bronchoscopy and brushing. Gene expression profiling showed global gene expression correlated well between ALI cells and brushed cells, but there were some differences. Gene expression patterns mirrored differences in proportions of cell types (ALI have higher percentages of basal cells, brushed cells have higher percentages of ciliated cells), with ALI cells expressing higher levels of basal cell-related genes and brushed cells expressing higher levels of cilia-related genes. Pathway analysis showed ALI cells had increased expression of cell cycle and proliferation genes, while brushed cells had increased expression of cytoskeletal organization and humoral immune response genes. Overall, ALI cells are a good representation of the in vivo airway epithelial transcriptome, but for some biologic questions, the differences in the in vitro vs in vivo environments need to be considered. Affymetrix arrays were used to assess the gene expression of large airway cells cultured in vitro at air-liquid interface (12 samples) and large airway epithelial cells obtained by fiberoptic bronchoscopy of 20 healthy nonsmokers. *** Air-liquid interface Samples not provided in this Series. ***
2010-07-07 | E-GEOD-18637 | biostudies-arrayexpress
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
2009-07-13 | E-GEOD-11952 | biostudies-arrayexpress
Project description:The first changes associated with smoking are in the small airway epithelium (SAE). Given that smoking alters SAE gene expression, but only a fraction of smokers develop chronic obstructive pulmonary disease (COPD), we hypothesized that assessment of SAE genome-wide gene expression would permit biologic phenotyping of the smoking response, and that a subset of healthy smokers would have a “COPD-like” SAE transcriptome. SAE (10th-12th generation) was obtained via bronchoscopy of healthy nonsmokers, healthy smokers and COPD smokers and microarray analysis was used to identify differentially expressed genes. Individual responsiveness to smoking was quantified with an index representing the % of smoking-responsive genes abnormally expressed (ISAE), with healthy smokers grouped into “high” and “low” responders based on the proportion of smoking-responsive genes up- or down-regulated in each smoker. Smokers demonstrated significant variability in SAE transcriptome with ISAE ranging from 2.9 to 51.5%. While the SAE transcriptome of “low” responder healthy smokers differed from both “high” responders and smokers with COPD, the transcriptome of the “high” responder healthy smokers was indistinguishable from COPD smokers. The SAE transcriptome can be used to classify clinically healthy smokers into subgroups with lesser and greater responses to cigarette smoking, even though these subgroups are indistinguishable by clinical criteria. This identifies a group of smokers with a “COPD-like” SAE transcriptome. Comparison of the transcriptome of small airway epithelium in healthy non-smokers, healthy smokers and smokers with COPD. One hundred and fifty-seven samples from several Series were compared.
2011-10-26 | E-GEOD-11784 | biostudies-arrayexpress
Project description:Background: Healthy individuals exposed to low levels of cigarette smoke have a decrement in lung function and higher risk for lung disease compared to unexposed individuals. We hypothesized that healthy individuals exposed to low levels of tobacco smoke must have biologic changes in the small airway epithelium compared to healthy unexposed individuals. Methods: Small airway epithelium was obtained by bronchoscopy from 121 individuals; microarrays assessed genome wide gene expression, and urine nicotine and cotinine were used to categorized subjects as “nonsmokers,” “active smokers,” and “low exposure.” The gene expression data was used to determine the threshold and ID50 of urine nicotine and cotinine at which the small airway epithelium showed abnormal responses. Results: There was no threshold of urine nicotine without an abnormal small airway epithelial response, and only a slightly above detectable threshold abnormal response for cotinine. The nicotine ID50 for nicotine was 25 ng/ml and cotinine 104 ng/ml. Conclusions: The small airway epithelium detects and responds to low levels of tobacco smoke with transcriptome modifications. This provides biologic correlates of epidemiologic studies linking low level tobacco smoke exposure to lung health risk, health, identifies genes in the lung cells most sensitive to tobacco smoke and defines thresholds at the lung epithelium responds to inhaled tobacco smoke. Affymetrix arrays were used to assess the gene expression data of smoking-responsive genes in the in small airway epithelium obtained by fiberoptic bronchoscopy of 48 healthy non-smokers (non-smoker or Nsaets), 65 healthy smokers (smoker), 7 symptomatic smokers (SYMs) and a healthy occasional smoker (OcSs). YSB and LO contributed equally to the study.
2011-02-02 | E-GEOD-19667 | biostudies-arrayexpress