Epigenetic control of the master regulator fumarate nitrate reductase (FNR) contributes to survival of Haemophilus influenzae during lung infection
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ABSTRACT:
ORGANISM(S): Haemophilus influenzae
PROVIDER: GSE276728 | GEO | 2025/08/20
REPOSITORIES: GEO
Similar Datasets
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:Background: Loss of secretory immunoglobulin A (SIgA) is common in COPD small airways and likely contributes to disease progression. We hypothesized loss of SIgA results from reduced expression of pIgR, a chaperone protein needed for SIgA transcytosis, in the COPD small airway epithelium. Methods: pIgR-expressing cells were defined and quantified at single-cell resolution in human airways using RNA in-situ hybridization, immunostaining, and single-cell RNA sequencing. Complementary studies in mice utilized immunostaining, primary murine tracheal epithelial cell (MTEC) culture, and transgenic mice with secretory or ciliated cell-specific knockout of pIgR. SIgA degradation by human neutrophil elastase or secreted bacterial proteases from non-typeable Haemophilus influenzae (NTHi) was evaluated in vitro. Results: We found that secretory cells are the predominant cell type responsible for pIgR expression in human and murine airways. Loss of SIgA in small airways was not associated with a reduction in secretory cells but rather a reduction in pIgR protein expression despite intact PIGR mRNA expression. Neutrophil elastase and NTHi-secreted proteases are both capable of degrading SIgA in vitro and may also contribute to a deficient SIgA immunobarrier in COPD. Interpretation: Loss of the SIgA immunobarrier in small airways of patients severe COPD is complex and likely results from both pIgR-dependent defects in IgA transcytosis and SIgA degradation.
2022-02-11 | GSE196341 | 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:The activity of DNA adenine methyltransferase (Dam) and DNA cytosine methyltransferase (Dcm) together account for nearly all methylated nucleotides in the Escherichia coli K-12 MG1655 genome. Previous studies have shown that perturbation of DNA methylation alters E. coli global gene expression, but it is unclear whether the methylation state of Dam or Dcm target sites regulates local transcription. We observed an underrepresentation of Dam sites in transcriptionally silent extended protein occupancy domains (EPODs), and we thus hypothesized that a methylation-deficient version of MG1655 would show large-scale aberrations in chromatin structure. To test our hypothesis, we cloned methyltransferase deletion strains and performed global protein occupancy profiling using high resolution in vivo protein occupancy display (IPOD-HR), chromatin immunoprecipitation for RNA polymerase (RNAP-ChIP), and transcriptome abundance profiling using RNA-Seq. Our results indicate that loss of DNA methylation does not result in large-scale changes in genomic protein occupancy such as the formation of EPODs. However, loci with dense clustering of Dam methylation sites show methylation-dependent changes in local RNA polymerase and total protein occupancy, but local transcription is unaffected. Our transcriptome profiling data indicates that deletion of dam and/or dcm results in significant expression changes within some functional gene categories including SOS response, flagellar synthesis, and translation, but these expression changes appear to result from indirect regulatory consequences of methyltransferase deletion. In agreement with the downregulation of genes involved in flagellar synthesis, dam deletion is characterized by a swimming motility-deficient phenotype. We thus conclude that DNA methylation does not control the overall protein occupancy landscape of the E. coli genome, and that observable changes in gene regulation are generally not resulting from regulatory consequences of local methylation state.
2025-06-01 | GSE279866 | GEO
Project description:Gene expression profiles in this submission were part of an integrative DNA methylation and gene expression integrative study. The goal of this study was to determine whether DNA methylation patterns were disrupted in small airway epithelia of patients with Chronic Obstructive Pulmonary Disease (COPD) compared to airways from subjects with normal lung function. No subject has cancer or asthma at time of collection. Corresponding DNA methylation profiles for these subjects can be found at GSE55454. We concluded that methylation alterations in COPD airways may underlie disease-specific gene-expression changes (such as the Nrf2 oxidative response pathway). RNA isolated from bronchial brushings was processed and hybridized to Affymetrix Human Gene 1.0 ST Arrays. DNA isolated from these same samples can be found at GSE55454
2014-03-28 | E-GEOD-56341 | biostudies-arrayexpress
Project description:Gene expression profiles in this submission were part of an integrative DNA methylation and gene expression integrative study. The goal of this study was to determine whether DNA methylation patterns were disrupted in small airway epithelia of patients with Chronic Obstructive Pulmonary Disease (COPD) compared to airways from subjects with normal lung function. No subject has cancer or asthma at time of collection. Corresponding DNA methylation profiles for these subjects can be found at GSE55454. We concluded that methylation alterations in COPD airways may underlie disease-specific gene-expression changes (such as the Nrf2 oxidative response pathway).
2014-03-28 | GSE56341 | GEO
Project description:Purpose:To identify whether accelerated aging can be observed in the airways of PLWH with COPD, manifest by a unique DNA methylation signature. Methods: Bronchial epithelial brushings from PLWH with and without COPD and HIV-uninfected adults with and without COPD (n=76) were profiled for DNA methylation and gene expression. We evaluated global Alu and LINE-1 methylation and calculated the epigenetic age using the Horvath clock and the methylation telomere length estimator. To identify genome-wide differential DNA methylation and gene expression associated with HIV and COPD, robust linear models were used followed by an expression quantitative trait methylation (eQTM) analysis. Results:Epigenetic age acceleration and shorter methylation estimates of telomere length were found in PLWH with COPD compared to PLWH without COPD and uninfected patients with and without COPD. We identified CpG sites, genes, and eQTM-gene pairs associated with the interaction between HIV and COPD. Conclusions: Methylation age acceleration is observed in the airway epithelium of PLWH with COPD, a process that may be responsible for the heightened risk of COPD in this population. Their distinct methylation profile, differing from that observed in patients with COPD alone, suggests a unique pathogenesis to HIV-associated COPD that warrants investigation into the candidate genes identified.
2022-03-18 | GSE178808 | GEO
Project description:Purpose:To identify whether accelerated aging can be observed in the airways of PLWH with COPD, manifest by a unique DNA methylation signature. Methods: Bronchial epithelial brushings from PLWH with and without COPD and HIV-uninfected adults with and without COPD (n=76) were profiled for DNA methylation and gene expression. We evaluated global Alu and LINE-1 methylation and calculated the epigenetic age using the Horvath clock and the methylation telomere length estimator. To identify genome-wide differential DNA methylation and gene expression associated with HIV and COPD, robust linear models were used followed by an expression quantitative trait methylation (eQTM) analysis. Results:Epigenetic age acceleration and shorter methylation estimates of telomere length were found in PLWH with COPD compared to PLWH without COPD and uninfected patients with and without COPD. We identified CpG sites, genes, and eQTM-gene pairs associated with the interaction between HIV and COPD. Conclusions: Methylation age acceleration is observed in the airway epithelium of PLWH with COPD, a process that may be responsible for the heightened risk of COPD in this population. Their distinct methylation profile, differing from that observed in patients with COPD alone, suggests a unique pathogenesis to HIV-associated COPD that warrants investigation into the candidate genes identified.
2022-03-18 | GSE178807 | GEO
Project description:Alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD) orchestrate persistent inflammation in the airway, however, sub-populations of alveolar macrophages predominantly participating in chronic inflammation have been poorly characterised. We recently reported that Siglec-1 was involved in recognition and engulfment of non-typeable Haemophilus influenzae and that the expression of Siglec-1 on AMs was decreased in COPD lung tissues. Here, based on the expression of Siglec-1 and the intensity of forward scattergram (FSC) using flow cytometry, we identified three subsets present in alveolar macrophages: Siglec-1+/FSChi, Siglec-1−/FSChi, Siglec-1−/FSClow subsets. The Siglec-1−/FSClow subset increased in number in the lungs of COPD subjects. RNA-sequencing revealed that the Siglec-1−/FSClow subset exhibited pro-inflammatory and protease-producing phenotypes compared to other two subsets. Clinically, a decrease in the intensity of Siglec-1 expression in macrophages of induced sputum from COPD subjects was correlated with exacerbation rates in prospective four years. Collectively Siglec-1− AMs showed the pro-inflammatory properties and that their emergence in COPD airways was a risk factor in exacerbation. The Siglec-1−/FSClow subset might serve as “pathogenic macrophages” which could lead to poor clinical outcomes for patients with COPD
2025-03-24 | GSE199345 | GEO