Corticosteroid therapy and airflow obstruction influence the bronchial microbiome, which is distinct from that of bronchoalveolar lavage in asthmatic airways.
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PROVIDER: PRJEB20525 | ENA |
REPOSITORIES: ENA
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Project description:Corticosteroid therapy and airflow obstruction influence the bronchial microbiome, which is distinct from that of bronchoalveolar lavage in asthmatic airways.
| PRJEB20527 | ENA
Project description:BackgroundThe lung has a diverse microbiome that is modest in biomass. This microbiome differs in asthmatic patients compared with control subjects, but the effects of clinical characteristics on the microbial community composition and structure are not clear.ObjectivesWe examined whether the composition and structure of the lower airway microbiome correlated with clinical characteristics of chronic persistent asthma, including airflow obstruction, use of corticosteroid medications, and presence of airway eosinophilia.MethodsDNA was extracted from endobronchial brushings and bronchoalveolar lavage fluid collected from 39 asthmatic patients and 19 control subjects, along with negative control samples. 16S rRNA V4 amplicon sequencing was used to compare the relative abundance of bacterial genera with clinical characteristics.ResultsDifferential feature selection analysis revealed significant differences in microbial diversity between brush and lavage samples from asthmatic patients and control subjects. Lactobacillus, Pseudomonas, and Rickettsia species were significantly enriched in samples from asthmatic patients, whereas Prevotella, Streptococcus, and Veillonella species were enriched in brush samples from control subjects. Generalized linear models on brush samples demonstrated oral corticosteroid use as an important factor affecting the relative abundance of the taxa that were significantly enriched in asthmatic patients. In addition, bacterial α-diversity in brush samples from asthmatic patients was correlated with FEV1 and the proportion of lavage eosinophils.ConclusionThe diversity and composition of the bronchial airway microbiome of asthmatic patients is distinct from that of nonasthmatic control subjects and influenced by worsening airflow obstruction and corticosteroid use.
| S-EPMC4860110 | biostudies-literature
Project description:Background: A subset of asthmatics does not respond to steroid therapy and therefore is at risk for escalation of disease severity. The cause of corticosteroid resistant (CR) asthma is unknown. Gene microarray technologies have the potential to substantiate new hypotheses regarding the etiology of corticosteroid resistance. Methods: Gene microarray analysis was performed with bronchoalveolar lavage (BAL) cells of CR and corticosteroid sensitive (CS) asthmatics. Increased gene expression was verified with real time PCR and at the protein level by ELISA. Findings: Microarray analyses demonstrated significantly higher levels (over two-fold increase, p<0.05) of TNF-alpha, IL-1alpha, IL-1beta, IL-6, CXCL1, CXCL2, CXCL3, CXCL8 (IL-8), CCL3, CCL4, CCL20 gene expression in BAL cells of CR than CS asthmatics. These findings, confirmed by RT-PCR in additional BAL samples, were consistent with classical macrophage activation by bacterial products. In contrast, markers of alternatively-activated macrophages, Arginase I and CCL24, were decreased in CR asthmatics. Genes associated with activation of the LPS signaling pathway (EGR1, DUSP2, MAIL, TNFAIP3) were significantly elevated in CR BAL samples (p<0.05). CR asthmatics had significantly higher amounts (1444.0±457.3 pg per mg of total protein) of LPS in BAL fluid than CS asthmatics (270.5±216.0 pg; p<0.05). Prolonged exposure to LPS induced functional steroid resistance to dexamethasone (DEX) in normal monocytes, demonstrated by persistently elevated IL-6 levels in the presence of DEX. Interpretation: Classical macrophage activation and induction of LPS signaling pathways along with high endotoxin levels detected in BAL fluid from CR asthmatics suggest that LPS exposure may contribute to CR asthma. Experiment Overall Design: Patients with a diagnosis of asthma according to American Thoracic Society criteria were selected for evaluation. Asthmatics had a baseline FEV1% predicted of 55% to 85% of predicted, a beta2-adrenergic response of â¥12% of baseline FEV1% predicted and/or a methacholine PC20 value of â¤8 mg/ml. Asthma patients were further subdivided in CR and CS groups, based on their response to steroids. The definition was based on change in FEV1 % predicted over a one-week course of 40 mg/day of oral prednisone. Asthmatic patients were defined as CS if they had an increase in FEV1% predicted of greater than 15% after a one-week course of prednisone, and as CR if less than 12% change in FEV1% predicted was observed. None of the asthmatic subjects recruited for this study had evidence for other types of lung diseases. None of the subjects had received systemic corticosteroid therapy for at least one month prior to bronchoscopy. All subjects provided written informed consent to participate in the study. The study was approved by the Institutional Review Board at National Jewish Medical and Research Center, Denver, CO. Gene array studies of BAL macrophages were performed in 3 CR and 3 CS asthmatics.
2009-07-01 | E-GEOD-7368 | biostudies-arrayexpress
Project description:Rationale: DNA methylation is an epigenetic modification that is highly disrupted in response to cigarette smoke and involved in a wide spectrum of malignant and non-malignant diseases, but surprisingly not previously assessed in small airways of patients with chronic obstructive pulmonary disease (COPD). Small airways are the primary sites of airflow obstruction in COPD. We sought to determine whether DNA methylation patterns are disrupted in small airway epithelia of COPD patients, and evaluate whether changes in gene expression are associated with these disruptions. Methods: Genome-wide methylation and gene expression analysis were performed on small airway epithelial DNA and RNA obtained from the same patient during bronchoscopy, using Illumina's Infinium HM27 and Affymetrix's Genechip Human Gene 1.0 ST arrays. To control for known effects of cigarette smoking on DNA methylation, methylation and gene expression profiles were compared between former smokers (FS) with and without COPD matched for age, pack years and years of smoking cessation. Results: Our results indicate that aberrant DNA methylation is i) a genome-wide phenomenon in small airways of patients with COPD and ii) associated with altered expression of genes and pathways important to COPD, such as the Nrf2 oxidative response pathway. Conclusions: DNA methylation is likely an important mechanism contributing to modulation of genes important to COPD pathology. Since these methylation events may underlie disease-specific gene-expression changes, their characterization is a critical first step towards the development of epigenetic markers and an opportunity for developing novel epigenetic therapeutic interventions for COPD. Bisulphite converted DNA from small airway (airways less than <2 mm in diameter) from 38 former smokers: 15 subjects with COPD (post bronchodilator FEV1/FVC ratio <70% and FEV1 predicted M-bM-^IM-$ 80%) and 21 with normal lung function, were hybridized to the Illumina Infinium 27k Human Methylation Beadchip.
2014-02-28 | E-GEOD-55454 | biostudies-arrayexpress
Project description:High numbers of goblet cells in airways contribute to the mucus obstruction characteristic of asthmatic airways. Allergen challenged mice exhibit robust expression of goblet cells within airway surface epithelium. This study looks at the temporal analysis of IL-13 exposed murine airways to elucidate pathways that result in differentiation of airway epithelial cells to goblet cells.
2008-06-13 | E-GEOD-481 | biostudies-arrayexpress
Project description:High numbers of goblet cells in airways contribute to the mucus obstruction characteristic of asthmatic airways. Allergen challenged mice exhibit robust expression of goblet cells within airway surface epithelium. This study looks at the temporal analysis of IL-13 exposed murine airways to elucidate pathways that result in differentiation of airway epithelial cells to goblet cells. Keywords: other
2003-07-16 | GSE481 | GEO
Project description:Rationale: DNA methylation is an epigenetic modification that is highly disrupted in response to cigarette smoke and involved in a wide spectrum of malignant and non-malignant diseases, but surprisingly not previously assessed in small airways of patients with chronic obstructive pulmonary disease (COPD). Small airways are the primary sites of airflow obstruction in COPD. We sought to determine whether DNA methylation patterns are disrupted in small airway epithelia of COPD patients, and evaluate whether changes in gene expression are associated with these disruptions. Methods: Genome-wide methylation and gene expression analysis were performed on small airway epithelial DNA and RNA obtained from the same patient during bronchoscopy, using Illumina's Infinium HM27 and Affymetrix's Genechip Human Gene 1.0 ST arrays. To control for known effects of cigarette smoking on DNA methylation, methylation and gene expression profiles were compared between former smokers (FS) with and without COPD matched for age, pack years and years of smoking cessation. Results: Our results indicate that aberrant DNA methylation is i) a genome-wide phenomenon in small airways of patients with COPD and ii) associated with altered expression of genes and pathways important to COPD, such as the Nrf2 oxidative response pathway. Conclusions: DNA methylation is likely an important mechanism contributing to modulation of genes important to COPD pathology. Since these methylation events may underlie disease-specific gene-expression changes, their characterization is a critical first step towards the development of epigenetic markers and an opportunity for developing novel epigenetic therapeutic interventions for COPD.
2014-02-28 | GSE55454 | GEO
Project description:Rationale: MicroRNAs have emerged as crucial post-transcriptional and network regulators in inflammatory diseases, including asthma. We hypothesized that peripheral blood miRNA would be associated with airflow obstruction in children with asthma, and that some of these effects would also be observable in adults with COPD. Methods: We analyzed small RNA-Seq data from 365 peripheral blood samples from the Genetics of Asthma in Costa Rica Study (GACRS). GACRS comprised children from the Central Valley of Costa Rica age 6-14 years with physician-diagnosed asthma and ≥2 respiratory symptoms or asthma attacks in the prior year. FEV1/FVC percent-predicted was dichotomized at 100%, splitting the cohort into those with and without evidence of airflow obstruction and used as our primary outcome. Differentially expressed (DE) miRs were identified using the DESeq2 package in R with a 10% FDR and adjustment for age, gender, and inhaled corticosteroid (ICS) use. We attempted to replicate the top airflow obstruction-associated microRNAs from the GACRS study in the COPDGene study, in which blood microRNA data were available in 439 current and former smoking adults with and without airflow obstruction (defined as raw FEV1/FVC < 0.7). Results: After QC, we had 361 samples and 649 miRs for DE analysis. Of the 361 samples, 220 and 141 were from subjects without and with airflow obstruction, respectively. We found 1 upregulated (let-7e-5p p=0.0004) and 2 downregulated (miR-342-3p p=0.0002; miR-671-5p p=0.0001) miRs in subjects with airflow obstruction compared to those without airflow obstruction. These three miRNAs were then tested for association with airflow obstruction in the COPDGene study, in which let-7e-5p was upregulated (p = 0.064) and miR-342-3p (p =0.085) was downregulated in participants with FEV1/FVC < 0.7 (n=196) compared to those with FEV1/FVC > 0.7 (n=243). Differentially expressed miR’s target genes were enriched for PI3K-Akt, Hippo, WNT, MAPK, and focal adhesion signaling pathways. We also separately considered the targets of only the two miRNAs that were also associated with FEV1/FVC in the adult current and former smokers, where PI3K-Akt, MAPK and Hippo signaling pathways were among the top five most enriched pathways. Conclusion: Three DE miRs were linked to airflow obstruction in children with asthma. Two miRs were associated with FEV1/FVC in current and former smoking adults. These miRs were involved in asthma and COPD-related pathways: PI3K-Akt, Hippo, MAPK, and focal adhesion signaling pathways. Together these findings provide important evidence that these two disorders may share genetic regulatory systems that contribute to airflow obstruction.
2023-10-01 | GSE244036 | GEO
Project description:Induced sputum is used to sample inflammatory cells, predominantly neutrophils and macrophages, from the airways of COPD patients. Our aim was to identify candidate genes associated with the degree of airflow obstruction and the extent of emphysema by expression profiling, and then to confirm these findings for selected candidates using specific PCR and protein analysis.
2010-06-08 | GSE22148 | GEO
Project description:Inhaled corticosteroids (ICS) control airway inflammation in mild to moderate asthma by reducing inflammatory gene expression. However, incomplete understanding of the molecular mechanisms underpinning corticosteroid action hinders development of improved therapies for more severe disease. Microarray analysis was performed on RNA from biopsies taken from healthy individuals after receiving single dose of ICS to characterize corticosteroid-induced modulation of gene expression in the human airways.
2016-06-11 | GSE83233 | GEO