Project description:Hallmarks of cystic fibrosis (CF) are increased viscosity of mucus and impaired mucociliary clearance within the airways due to mutations of the cystic fibrosis conductance regulator gene. This paves the way for the colonization by microbial pathogens and the concomitant establishment of chronic infections leading to lung tissue damage, reduced lung function, and to decreased life expectancy. Although microbial infections play a key role during disease progression, only a few studies investigated the pathophysiology of the microbial community in vivo so far. Moreover, no CF study so far applied metaproteomics, a powerful approach to unravel molecular mechanisms of microbial infection, mainly reasoned due to (I) the challenging processability of inhomogeneous, viscous, slimy sputum, and (II) the high number of human proteins masking comparably low abundant microbial proteins. Consequently, we developed a reliable, reproducible and widely applicable protocol for sputum processing, microbial enrichment, and subsequent metaproteomics analyses with a focus on microbial pathogens overcoming the aforementioned challenges. Metaproteomics data were complemented and validated by 16S sequencing, metabolomic as well as microscopic analyses. In total, we processed 21 CF sputum samples and selected three for detailed metaproteome analysis. The number of bacterial proteins/protein groups increased from 199-425 to 392-868. Moreover, our data suggest that the arginine deiminase pathway and multiple proteases and peptidases identified from various bacterial genera are so far underappreciated in their contribution to the CF pathophysiology. By providing a standardized and effective protocol for sputum processing and microbial enrichment, our study represents an important basis for future studies investigating the physiology of microbial pathogens in CF in vivo – an important prerequisite for the development of novel antimicrobial therapies against mucoviscidosis.
2021-11-03 | PXD025134 | Pride
Project description:microbial composition of human sputum
Project description:Sputum cells collected before (visit 2) and after (visit 4) allergen challenge in asthma patients were isolated and RNA purified for analysis on gene expression arrays. Human subject recruitment part of NIH sponsored protocol as part of the Eosinophil Program Project Grant (PI: Dr. Nizar Jarjour) Sputum cell RNA collected from induced sputum cells before and 48 hours after whole-lung allergen challenge.
Project description:In addition to analyzing whole-genome methylation, we concomitantly evaluated sputum cell gene expression in the context of chronic inflammatory lung disease. Nucleic acids were purified from sputum samples of subjects with Asthma, COPD as well as healthy controls. Gene expression was analyzed on the Agilent Human GE 4x44k v2 platform.
Project description:Several microRNAs (miRs) have been described as potential biomarkers in liquid biopsies and in the context of allergic asthma, while therapeutic effects on the airway expression of miRs remain elusive. In this study, we investigated epigenetic miR-associated mechanisms in the sputum of grass pollen allergic patients with and without allergen specific immunotherapy (AIT). Induced sputum samples of healthy controls (HC), AIT treated and untreated grass pollen allergic rhinitis patients with (AA) and without asthma (AR) were profiled using miR microarray and transcriptome microarray analysis of the same samples. miR targets were predicted in silico and used to identify inverse regulation. Local PGE2 levels were measured using ELISA. Two Hundred and fifty nine miRs were upregulated in the sputum of AA patients compared with HC, while only one was downregulated. The inverse picture was observed in induced sputum of AIT-treated patients: while 21 miRs were downregulated, only 4 miRs were upregulated in asthmatics upon AIT. Of these 4 miRs, miR3935 stood out, as its predicted target PTGER3, the prostaglandin EP3 receptor, was downregulated in treated AA patients compared with untreated. The levels of its ligand PGE2 in the sputum supernatants of these samples were increased in allergic patients, especially asthmatics, and downregulated after AIT. Finally, local PGE2 levels correlated with ILC2 frequencies, secreted sputum IL13 levels, inflammatory cell load, sputum eosinophils and symptom burden.While profiling the sputum of allergic patients for novel miR expression patterns, we uncovered an association between miR3935 and its predicted target gene, the prostaglandin E3 receptor, which might mediate AIT effects through suppression of the PGE2-PTGER3 axis.
Project description:Our findings have clinical implications. Identification of sputum exosomal miRNA helps explore the important biological pathways underlying the pathogenesis of bronchiectasis, thus unraveling candidate targets for future interventions of PA colonization. Apart from canonical inflammatory pathways, we have unraveled the modulation of longevity regulation pathway which opens a new avenue for exploring how PA colonization interacts with the airway epithelium. The significant correlation between sputum inflammatory biomarkers and miR-92b-5p and miR-223-3p provided further evidence on the unresolved inflammation in the PA-colonized microenvironment. However, causality cannot be inferred based on the current study design.
Project description:Comparison of the gene expression profile of Moraxella catarrhalis grown in the presence of 20% pooled human sputum in chemically-defined medium relative to Moraxella catarrhalis grown in chemically-defined medium alone. Moraxella catarrhalis ATCC43617 was grown to mid-logarithmic phase either in the presence of 20% pooled human sputum in chemically-defined medium or in chemically-defined medium alone. Total RNA was extracted from bacterial cells exposed to each of these conditions and cDNA was generated for CyDye labelling. 3 biologic replicates were generated and each replicate underwent a dye swap (total of 6 experimental data collections). The gene expression profile reported is that of Moraxella catarrhalis grown in the presence of pooled human sputum in a chemically-defined medium relative to Moraxella catarrhalis grown only in the presence of the chemically-defined medium.
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.