Project description:Gene expression profiles were generated from induced sputum samples in COPD and healthy controls. The study identified transcriptional phenotypes of COPD.
Project description:Background: Assessments of airways inflammation in patients with chronic obstructive pulmonary diseases (COPD) require semi-invasive procedures and specialized sample processing know-how. In this study we aimed to set up and validate a novel non-invasive processing-free method for RNA sequencing (RNAseq) of spontaneous sputum samples collected from COPD patients. Methods: Spontaneous sputum samples were collected and stabilized, with or without selection of plugs and with or without the use of a stabilizer specifically formulated for downstream diagnostic testing (PrimeStore® Molecular Transport Medium). After 8-day storage at ambient temperature RNA was isolated according to an optimized RNAzol® method. An average percentage of fragments longer than 200 nucleotides (DV200) >30% and an individual yield >50ng were required for progression of samples to sequencing. Finally, to assess if the transcriptome generated would reflect a true endotype of COPD inflammation, the outcome of single-sample gene-set enrichment analysis (ssGSEA) was validated using an independent set of processed induced sputum samples Results: RNA extracted from spontaneous sputum using a stabilizer showed an average DV200 higher than 30%. 70% of the samples had a yield >50ng and were submitted to downstream analysis. There was a straightforward correlation in terms of gene expression between samples handled with or without separation of plugs. This was also confirmed by principal component analysis and ssGSEA. The top ten enriched pathways resulting from spontaneous sputum ssGSEA were associated to features of COPD, namely, inflammation, immune responses and oxidative stress; up to 70% of these were in common within the top ten enriched pathways resulting from induced sputum ssGSEA. Conclusion: This analysis confirmed that the typical COPD endotype was represented within spontaneous sputum and supported the current method as a non-invasive processing-free procedure to assess the level of sputum cell inflammation in COPD patients by RNAseq analysis.
Project description:Long-term, low dose azithromycin reduces exacerbation frequency in COPD yet the mechanism remains unclear. This study characterises changes to gene expression in patients with neutrophilic COPD in response to long term low dose azithromycin therapy. Patients with neutrophilic COPD (>61% or >162x10^4/mL sputum neutrophils) were randomised to 12 weeks of either azithromycin or placebo treatment. RNA was extracted from sputum and blood collected before (pre) and after (post) treatment.
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.
