Project description:Hyaluronan (HA) is the major glycosaminoglycan in the extracellular matrix involved in the pathogenesis of asthma and other chronic inflammatory diseases. During inflammation there is an increased breakdown of HA, resulting in the local and systemic accumulation of low molecular weight (LMW) HA. Eicosanoids, derived from cytosolic phospholipase A2 group IVA activation, are potent lipid mediators also attributed to acute and chronic inflammation. We investigated the effect of LMW HA on lipidomic profile and global gene expression in PBMCs of patients with mild-to-moderate and severe asthma. We found that LMW HA increased production of 68 unique lipid species, among which PGE2, PGA2, PGD2, PGF2a, 15-HETE, TxB2, 11,12-EET, 14,15 EET, 13-HOTrE(y) and 16 (17) EpDPE were significantly upregulated in severe asthmatics. We also performed a systematic genome-wide expression analysis of LMW HA signaling, confirming its highly immunostimulatory potential. However, in severe asthmatics the LMW HA-induced global gene expression profile showed a comprehensive impairment in interferon signaling, cell apoptosis and cell movement, leading to diminished antiviral responses. Likewise, LMW HA-induced production of IL12 p40, CXCL10, CXCL11 and CCL8was markedly reduced in severe asthmatics. Our findings suggest a previously unforeseen link between extracellular matrix, global lipid production and antiviral responses in the pathogenesis of severe asthma. We used microarray to perform a systematic genome-wide expression analysis of LMW HA effect in peripheral blood mononuclear cells in control subjects, mild-to moderate asthma and severe asthma patients
Project description:Asthma is an inflammatory disease of the airways characterised by episodic airway obstruction resulting in cough, episodic shortness of breath. It is, and is clinically and physiologically heterogeneous. It is estimated that around 300 million people worldwide have the diseaseare diagnosed with asthma, including up to 20% of children (Asher et al, 2006), with 5–10% of these children believed to have severe or difficult-to-treat asthma. Asthma has often been classified in terms of severity and based on clinical diagnostic criteria, but it is now apparent that the heterogeneity that exists at the physiological level is also a feature of the underlying pathological mechanisms (Lotvall et al, 2011). The aim of this study was to identify blood transcriptomics profiles for children diagnosed with asthma or wheeze, and establish whether these profiles suggested endotypes or mechanisms that could underlie disease, or be related to disease severity, in these children. Importantly, given that children are currently treated with the same medicines as adults, we also aimed to compare profiles of children to those of adults with asthma to help determine whether efforts should be directed to the development of medicines targeting pathways and mechanisms that may be unique to children. To this end, we used gene transcriptome data generated from blood samples from adults and children from the U-BIOPRED consortium to ask how similar or different the differential gene expression profiles were between groups of adults and pre-school or school-aged children with severe or mild-moderate asthma (or wheeze for the pre-school aged children) using current definitions. The Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project was set up as a public-private partnership within the framework of the Innovative Medicines Initiative (IMI), engaging academia, the pharmaceutical industry and patient groups. The goal of this investigation was to identify transcript fingerprints in whole blood that characterize patients with severe asthma and to determine whether subgroups of severe asthmatics can be identified.
Project description:Severe asthma is a collection of disease entities with varying pathophysiological characteristics (7) that result in symptoms of cough, wheeze and breathlessness, with frequent exacerbations. To address the problem of phenotypic difference and heterogeneity, the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project was set up as a public-private partnership within the framework of the Innovative Medicines Initiative (IMI), engaging academia, the pharmaceutical industry and patient groups. The goal of this investigation was to identify transcript fingerprints in whole blood that characterize patients with severe asthma and to determine whether subgroups of severe asthmatics can be identified. Furthermore, we were interested in elucidating the biological pathways that showed differences between subgroups.
Project description:Severe asthma is a collection of disease entities with varying pathophysiological characteristics that result in symptoms of cough, wheeze and breathlessness, with frequent exacerbations. To address the problem of phenotypic difference and heterogeneity, the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project was set up as a public-private partnership within the framework of the Innovative Medicines Initiative (IMI), engaging academia, the pharmaceutical industry and patient groups. The goal of this investigation was to identify proteomic fingerprints in induced sputum that characterize patients with severe asthma and to determine whether subgroups of severe asthmatics can be identified. Furthermore, we were interested in elucidating the biological pathways that showed differences between subgroups. This dataset is a description of the normal sputum proteome.
Project description:In order to better understand the systemic immunological responses in a clinical cohort of obese and non-obese asthmatics and healthy subjects, we sought to analyze gene expression from whole blood. We collected whole blood samples from 156 donors and performed gene expression analysis of these samples and identified differentially expressed genes (DEGs) in each obese and/or asthma group relative to healthy volunteers.
Project description:Airway epithelial brushings were obtained for microarray analysis by research bronchoscopy in 62 subjects with mild-to-moderate asthma not on inhaled steroids and 43 healthy controls. Asthma subjects were stratified into 2 subgroups, Th2 high and Th2 low asthma, based on their expression of a three-gene signature of Type 2 inflammation: POSTN, SERPINB2, and CLCA1. Gene expression comparisons were made between: 1. asthmatics and healthy controls, and 2. Th2 high asthma and Th2 Low asthma/Healthy controls. The gene expression alterations most associated with asthma were then used in gene set enrichment analyses and gene signature development to compare this asthma dataset to COPD gene expression datasets.
Project description:Background: Around 5% of children with asthma suffer from chronic symptoms and/or severe exacerbations despite extensive treatment. The causes of severe therapy-resistant childhood asthma are poorly understood. Objectives: To define global patterns of gene expression in severe therapy-resistant vs. controlled asthma and healthy controls. Methods: Children with severe, therapy-resistant (SA, n=20) and controlled asthma (CA, n=20) were identified from a Swedish nation-wide study including extensive clinical and immunological characterisation. In addition, healthy controls were recruited (Ctrl, n=19). White blood cells were isolated and the global transcriptome profile was characterised using the Affymetrix Human Gene ST 1.0 chip. Results: 1378 genes were differentially expressed in one or several of the CA vs. Ctrl, SA vs. CA or SA vs. Ctrl contrasts. A large number could uniquely differentiate the SA group from the CA (n=351 genes) and Ctrl (n=315) groups, whereas fewer genes differentiated the CA from the Ctrl group (n=149). Several non-coding RNAs were found up-regulated in SA compared to CA or Ctrl. Three significantly enriched KEGG pathways were represented; bitter taste transduction, TAS2Rs (up-regulated mostly in SA), natural killer cell mediated cytotoxicity (up-regulated in CA) and N-Glycan biosynthesis (down-regulated in SA). An unsupervised hierarchical clustering of the 1378 genes could crudely separate the SA, CA and Ctrl individuals. Conclusion: Our data indicate a separation in gene expression patterns between children with severe, therapy-resistant asthma and controlled persistent asthma, and suggest novel pathways characterizing the severe therapy-resistant asthma phenotype. The transcriptomes of 59 subjects were assayed on the Affymetrix Human Gene ST 1.0 expression array. All samples passed pre-hybridisation quality control. After pre-processing and quality control of the post-hybridised arrays, five samples were regarded as outliers and removed (ctrl 510, MA 248, SA 141, SA 261, SA 41). The remaining sample set of 17 severe asthmatics (SA), 19 mild asthmatics (MA) and 18 controls (ctrl) were used for down-stream analysis.
Project description:Comparison of mRNA expression showed widespread changes in the circulating CD8+ but not CD4+ T-cells from patients with severe asthma. No changes were observed in the CD4+ and CD8+ T-cells in non-severe asthmatics versus healthy controls. Bioinformatics analysis showed that the changes in CD8+ T-cell mRNA expression were associated with multiple pathways involved in T-cell activation. As with mRNAs, we also observed widespread changes in expression of non-coding RNA species including natural antisense, pseudogenes, intronic long ncRNAs and long intergenic long ncRNAs in CD8+ T-cells from severe asthmatics. Measurement of the miRNA expression profile showed selective down-regulation of miR-28-5p in CD8+ T-cells and reduction of miR-146a and miR-146b in both CD4+ and CD8+ T-cells. mRNA samples were collected from circulating CD4+ and CD8+ T-cells from healthy donors as well as donors with severe and non-severe asthma.
Project description:Rationale: DNA methylation plays a critical role in asthma development, but differences in DNA methylation associated with asthma severity, especially among adults, are less well-defined. Changes in DNA methylation are influenced by exposure to air pollution, which is a risk factor for asthma exacerbation and severity. Here, we examined how DNA methylomic patterns in adult asthmatics differ by asthma severity and exposure to different components of air pollution. Methods: Peripheral blood CD3+ T cells from adult asthmatics in Beijing, China were serially collected from 37 patients (130 samples total) and analyzed for global DNA methylation using the Illumina MethylationEPIC Array. Measurements and Main Results: Significant differences in DNA methylation were noted among subjects with different degrees of asthma severity, as measured by fraction of exhaled nitric oxide, forced expiratory volume, and asthma control test scores. Differences in DNA methylation were annotated to genes that were enriched in pathways related to asthma or T cell function, and included gene ontology categories related to cellular adhesion, developmental pathways, and calcium signaling. Notable genes that were differentially methylated based on asthma severity included RUNX3, several members of the HLA family, PDGFRA, CDH1, CAV1, and NOTCH4. Differences in DNA methylation also varied by exposure to ambient air pollution, with different components of pollution effecting methylation of different groups of genes. Conclusion: These findings demonstrate how adult asthmatics possess widespread differences in the DNA methylation that associated with varying asthma severity and how air pollution might contribute to more severe asthma via changes in DNA methylation.
Project description:Molecular profiling studies in asthma cohorts have identified a Th2-driven asthma subtype, characterized by elevated lower airway expression of POSTN, CLCA1 and SERPINB2. To assess upper airway gene expression as a potential biomarker for lower airway Th2 inflammation, we assayed upper airway (nasal) and lower airway (bronchial) epithelial gene expression, serum total IgE, blood eosinophils and serum periostin in a cohort of 54 allergic asthmatics and 30 matched healthy controls. 23 of 51 asthmatics in our cohort were classified as âTh2 highâ based on lower airway Th2 gene signature expression. Consistent with this classification, âTh2 highâ subjects displayed elevated total IgE and blood eosinophil levels relative to âTh2 lowâ subjects. Upper airway Th2 signature expression was significantly correlated with lower airway Th2 signature expression (r=0.44), with similar strength of association as serum total IgE and blood eosinophils, known biomarkers of Th2 inflammation. In an unbiased genome-wide scan, we identified 8 upper airway genes more strongly correlated with lower airway Th2 gene signature expression (r=0.58), including Eotaxin-3 (CCL26), Galectin-10 (CLC) and Cathepsin-C (CTSC). Asthmatics classified as âTh2 highâ using this 8-gene signature show similar serum total IgE and blood eosinophil levels as âTh2 highâ asthmatics classified using lower airway Th2 gene signature expression. We have identified an 8-gene upper airway signature correlated with lower airway Th2 inflammation, which may be used as a diagnostic biomarker for Th2-driven asthma. Upper airway (nasal) and lower airway (bronchial) epithelial brushings obtained from a cohort of 54 allergic asthmatics and 30 matched healthy controls were profiled by gene expression by microarray. Subjects were assayed for gene expression, serum total IgE, blood eosinophils and serum periostin.