Project description:To better understand the molecular determinants of lung disease variability among patients with cystic fibrosis (CF), we carried out an epigenome-wide association study (EWAS) in sputum samples from patients with CF. Sputum samples were collected from 50 patients with CF at four time points (visit 1, 2, 3 and 4) over an 18-month follow-up period. We profiled 64 sputum samples collected at visit 1 and 2, using human methylation BeadChips (EPIC). Selected CpG sites were reassessed in independent sputum samples collected at visit 3 and 4, by pyrosequencing. Overall, we provide the first longitudinal assessment of genome-wide DNA methylation in a cohort of patients with CF and identify CpG sites that predict clinical traits of key importance for lung disease. Specifically, we identified (i) differentially methylated CpG sites that correlate with lung function (FEV1pp), (ii) a DNA methylation signature that predicts patients with a pulmonary exacerbation and (iii) CpG sites that split patients with declining lung function from those whose lung function either improved or remained stable.
Project description:Little is known about the lung microbiome dynamics and host-microbiome interactions in relation to chronic obstructive pulmonary disease (COPD) exacerbations and in patient subgroups based on smoking status and disease severity. Here we performed a 16S ribosomal RNA survey on sputum microbiome from 16 healthy and 43 COPD subjects. For COPD subjects, a longitudinal sampling was performed from stable state to exacerbations, at two and six weeks post-exacerbations and at six months from first stable visit. Host sputum transcriptome were characterized for a subset of COPD patient samples.
Project description:One of the hallmarks of Pseudomonas aeruginosa cystic fibrosis (CF) infection is very high-cell-density (HCD) replication in the lung, allowing this bacterium to induce virulence controlled by HCD quorum-sensing systems. However, the nutrient sources sustaining HCD replication in this chronic infection is largely unknown. Hence, understanding the nutrient factors contributing to HCD in the CF lung will yield new insights into the 'metabolic pathogenicity' and potential treatment of CF infections caused by P. aeruginosa. Herein, we performed microarray studies of P. aeruginosa directly isolated from the CF lung to demonstrate its metabolic capability and virulence in vivo. Our in vivo microarray data, confirmed by real-time reverse-transcription-PCR, indicated P. aeruginosa expressed several genes for virulence, drug-resistance, and utilization of multiple nutrient sources (lung surfactant lipids and amino acids) contributing to HCD replication. The data also indicates deregulation of several pathways, suggesting in vivo evolution by deregulation of a large portion of the transcriptome during chronic CF infection. To our knowledge, this is the first in vivo transcriptome of P. aeruginosa in a natural CF infection, and it indicates several important aspects of pathogenesis, drug-resistance, and nutrient-utilization never before observed in vivo. Experiment Overall Design: The purpose of the experiment was to observe which genes are upregulated in P. aeruginosa during chronic CF lung infection as compared to PAO1. All in vitro studies were grown in 1x M9 minimal media supplemented with 20 mM citrate and grown to mid-log phase prior to RNA isolation. The in vivo RNA was isolated directly from CF sputum samples after TRIzol treatment. Each in vitro sample (both for PAO1 and the CF sputum pool isolate) were processed individually and in triplicate. Two in vivo isolations from sputum were conducted from the same patient but two different sputum samples. After isolation of total RNA, samples were processed for microarrays (i.e. cDNA synthesis, fragmentation, labeling, etc) as recommended by Affymetrix, and processed on the GeneChip as recommended by Affymetrix.
Project description:A collection of cross sectional sputum samples and some longitudinal from adult patients at the UCSD adult CF center. These samples were extracted in both ethyl actetate/methanol and in 80% ethanol.
Project description:The PANarray design (GPL13324) contains the genes of eight P. aeruginosa genomes in non-redundant format, thus allowing identification of expression of non-PAO1 and other P. aeruginosa genes. For the series GSE28152, isogenic isolates were sequentially collected from two cystic fibrosis (CF) patients several years apart. The isolates had not been eradicated in the meantime and represent persister strains. One was an Australian Epidemic Strain-1 isolate and the other a non-epidemic strain. Strains were cultured in an artificial sputum medium (ASMDM) closely resembling CF sputum.
Project description:Chronic airway infection with P. aeruginosa (PA) is a hallmark of cystic fibrosis (CF) disease. The mechanisms producing PA persistence in CF therapies remain poorly understood. To gain insight on PA physiology in patient airways and better understand how in vivo bacterial functioning differs from in vitro conditions, we investigated the in vivo proteomes of PA in 35 sputum samples from 11 CF patients. We developed a novel bacterial-enrichment method enabling improved identification of PA proteome with CF sputum samples. The in vivo PA proteomes were compared with the proteomes of ex vivo-grown PA populations from the same patient sample. We detected 1528 PA proteins (encoded by 1458 core genes and 70 accessory genes) that were expressed in CF airways, of which 1178 proteins were commonly identified with the ex vivo-grown PA populations. Label-free quantitation and proteome comparison revealed the in vivo up-regulation of siderophore TonB-dependent receptors, remodeling in central carbon metabolism including glyoxylate cycle and lactate utilization, and alginate overproduction. Knowledge of these in vivo proteome differences or others derived using the presented methodology could lead to future treatment strategies aimed at altering PA physiology in vivo to compromise infectivity or improve antibiotic efficacy.
Project description:[1] Transcription profiling of one Burkholderia cenocepacia clinical isolate, J2315, versus a soil isolate, HI2424, in conditions mimicking CF sputum [2] Transcription profiling of Burkholderia cenocepacia isolates J2315 and HI2424 in media mimicking CF sputum or the soil environment