Project description:In the first decade of life, high-asthma risk urban children develop stable phenotypes of respiratory health versus disease that link early life environmental exposures to childhood allergic sensitization and asthma. Moreover, unique patterns of nasal gene expression demonstrate how specific molecular pathways underlie distinct respiratory phenotypes, including allergic and non-allergic asthma.
Project description:Obesity is associated with severe, difficult to control asthma, and increased airway oxidative stress. Mitochondrial reactive oxygen species (mROS) are an important source of oxidative stress leading us to hypothesize that targeting mROS in obese allergic asthma might be an effective treatment strategy. Using a mouse model of house dust mite (HDM) induced allergic airway disease in mice fed a low- (LFD) or high-fat diet (HFD), and the mitochondrial antioxidant MitoQuinone (MitoQ); we investigated the effects of obesity and mROS on airway inflammation, remodelling and airway hyperreactivity (AHR). HDM induces airway inflammation, remodelling and hyperreactivity in both lean and obese mice. Obese allergic mice showed increased lung tissue eotaxin levels, airway tissue eosinophilia and AHR when compared to lean allergic mice. MitoQ reduced markers of airway inflammation, remodelling and hyperreactivity in both lean and obese allergic mice, and tissue eosinophilia in obeseHDM mice. mROS regulates cell signalling by protein oxidation of multiple downstream targets: MitoQ reduced HDM-induced cysteine-sulfenylation of several proteins including those involved in the unfolded protein response (UPR). In summary, mROS mediates the development of allergic airway disease and hence MitoQ might be effective for the treatment for asthma, and specific features of obese asthma.
Project description:Chronic allergic asthma alters the lung m6A epitranscriptome, suggesting functional implications in the pathophysiology of refractory asthma. Methylated IL17RB mRNA possibly become a new therapeutic target for chronic allergic asthma.
Project description:Allergic asthma is a complex trait. Several approaches have been used to identify biomarkers involved in this disease. This study aimed at demonstrating the relevance and validity of microarrays in the definition of allergic asthma expression pattern. The authors compared the transcript expressions of bronchial biopsy of 2 different microarray experiments done 2 years apart, both including nonallergic healthy and allergic asthmatic subjects (n = 4 in each experiment). U95Av2 and U133A GeneChips detected respectively 89 and 40 differentially expressed genes. Fifty-five percent of the U133A genes were previously identified with the U95Av2 arrays. The immune signaling molecules and the proteolytic enzymes were the most preserved categories between the 2 experiments, because 3/4 of the genes identified by the U133A were also significant in the U95Av2 study for both categories. These results demonstrate the relevance of microarray experiments using bronchial tissues in allergic asthma. The comparison of these GeneChip studies suggests that earlier microarray results are as relevant as actual ones to target new genes of interest, particularly in function categories linked to the studied disease. Moreover, it demonstrates that microarrays are a valuable technology to target novel allergic asthma pathways as well as biomarkers. 4 healthy controls without history of allergy and asthma and 4 allergic asthmatic subjects according to the American Thoracic Society (ATS) criteria were selected
Project description:While the pathogenesis of asthma is mainly orchestrated by antigen-specific Th2 cells and their cytokines, recent findings indicate the involvement of other subsets of helper T cells including Th17 cells. Previous studies have shown that IL-22, one of Th17 cell-related cytokines, plays multiple roles in regulating allergic airway inflammation; however, the mechanism underlying the Il-22-mediated regulation remains unclear. Here, we show that allergic airway inflammation upon intratracheal administration of house dust mite extract (HDM), a representative allergen, were exacerbated in IL-22-deficient mice. To address the molecular mechanisms by which IL-22 inhibits the development of HDM-induced allergic airway inflammation, we next performed an unbiased comprehensive screening of genes induced by IL-22 administration in the lung by RNA-seq analysis.
Project description:Asthma is a complex syndrome associated with episodic decompensations provoked by aeroaller-gen exposures. The underlying pathophysiological states driving exacerbations are latent in the resting state and do not adequately inform biomarker-driven therapy. A better understanding of the pathophysiological pathways driving allergic exacerbations is needed. We hypothesized that disease-associated pathways could be identified in humans by unbiased metabolomics of bron-choalveolar fluid (BALF) during the peak inflammatory response provoked by a bronchial aller-gen challenge. We analyzed BALF metabolites in samples from 12 volunteers who underwent segmental bronchial antigen provocation (SBP-Ag). Metabolites were quantified using liquid chromatography-tandem mass spectrometry (LC–MS/MS) followed by pathway analysis and cor-relation with airway inflammation. SBP-Ag induced statistically significant changes in 549 fea-tures that mapped to 72 uniquely identified metabolites. From these features, two distinct induci-ble metabolic phenotypes were identified by the principal component analysis, partitioning around medoids (PAM) and k-means clustering. Ten index metabolites were identified that in-formed the presence of asthma-relevant pathways, including unsaturated fatty acid produc-tion/metabolism, mitochondrial beta oxidation of unsaturated fatty acid, and bile acid metabolism. Pathways were validated using proteomics in eosinophils. A segmental bronchial allergen chal-lenge induces distinct metabolic responses in humans, providing insight into pathogenic and pro-tective endotypes in allergic asthma.
Project description:Rationale: MicroRNAs have emerged as crucial post-transcriptional and network regulators in inflammatory diseases, including asthma. We hypothesized that peripheral blood miRNA would be associated with airflow obstruction in children with asthma, and that some of these effects would also be observable in adults with COPD. Methods: We analyzed small RNA-Seq data from 365 peripheral blood samples from the Genetics of Asthma in Costa Rica Study (GACRS). GACRS comprised children from the Central Valley of Costa Rica age 6-14 years with physician-diagnosed asthma and ≥2 respiratory symptoms or asthma attacks in the prior year. FEV1/FVC percent-predicted was dichotomized at 100%, splitting the cohort into those with and without evidence of airflow obstruction and used as our primary outcome. Differentially expressed (DE) miRs were identified using the DESeq2 package in R with a 10% FDR and adjustment for age, gender, and inhaled corticosteroid (ICS) use. We attempted to replicate the top airflow obstruction-associated microRNAs from the GACRS study in the COPDGene study, in which blood microRNA data were available in 439 current and former smoking adults with and without airflow obstruction (defined as raw FEV1/FVC < 0.7). Results: After QC, we had 361 samples and 649 miRs for DE analysis. Of the 361 samples, 220 and 141 were from subjects without and with airflow obstruction, respectively. We found 1 upregulated (let-7e-5p p=0.0004) and 2 downregulated (miR-342-3p p=0.0002; miR-671-5p p=0.0001) miRs in subjects with airflow obstruction compared to those without airflow obstruction. These three miRNAs were then tested for association with airflow obstruction in the COPDGene study, in which let-7e-5p was upregulated (p = 0.064) and miR-342-3p (p =0.085) was downregulated in participants with FEV1/FVC < 0.7 (n=196) compared to those with FEV1/FVC > 0.7 (n=243). Differentially expressed miR’s target genes were enriched for PI3K-Akt, Hippo, WNT, MAPK, and focal adhesion signaling pathways. We also separately considered the targets of only the two miRNAs that were also associated with FEV1/FVC in the adult current and former smokers, where PI3K-Akt, MAPK and Hippo signaling pathways were among the top five most enriched pathways. Conclusion: Three DE miRs were linked to airflow obstruction in children with asthma. Two miRs were associated with FEV1/FVC in current and former smoking adults. These miRs were involved in asthma and COPD-related pathways: PI3K-Akt, Hippo, MAPK, and focal adhesion signaling pathways. Together these findings provide important evidence that these two disorders may share genetic regulatory systems that contribute to airflow obstruction.
Project description:Background: A specific subset of regulatory IL-10 producing B cells has been extensively studied in autoimmune and inflammatory pathologies. These cells are able to constrain exacerbated inflammation by inhibiting T cell mediated responses and maturation of antigen presenting cells. In allergic diseases, observations that increase of regulatory B cells is necessary for allergen tolerance suggest that development of allergic asthma would be associated with a defect in the regulatory B cells compartment. Objective: We sought to (i) characterize regulatory IL-10+ regulatory B cell subset in Balb/c mice by microarray and flow cytometry and (ii) investigate their regulatory capacity in vivo in a house dust mite model of allergic asthma. Results: We identified an IL-10 producing B cells subset able to control T cell proliferation in vitro in both control and asthmatic mice. This subset is decreased in allergic mice. IL-10+ Breg cells express high levels of CD9 and upregulate CD70 and CD73 after activation. Expression of CD9 allows identifying more than 50% of Bregs. Interestingly CD9+ B cells inhibit TH2-TH17 allergic airway inflammation in vivo after adoptive transfer in an IL-10 dependent manner. Conclusions: Herein, we demonstrate that induction of allergic asthma dampens the generation of Bregs contributing to exacerbated airway inflammation. We identified a distinct CD9+ Breg-cell population decreased in lung of HDM mice and able to control asthma and allergic airway inflammation by producing IL-10 after adoptive transfer. This study points B cells as an interesting therapeutic target in allergic asthma. IL-10+ B cells (n=3) and 3 IL-10- B cells (n=3) in control mice + IL-10+ B cells (n=3) and 3 IL-10- B cells (n=3) from asthmatic allergic (HDM) mice
Project description:The link between upper and lower airways in patients with both asthma and allergic rhinitis is still poorly understood. As the biological complexity of these disorders can be captured by gene expression profiling we hypothesized that the clinical expression of rhinitis and/or asthma is related to differential gene expression between upper and lower airways epithelium. We used micro array to profile gene expression of primary nasal and bronchial epithelial cells from the same individuals and examining the impact of allergic rhinitis with and without concomitant allergic asthma on expression profiles. 17 subjects were included in a cross-sectional study (6 allergic asthma and allergic rhinitis; 5 allergic rhinitis; 6 healthy controls). RNA was extracted from isolated and cultured epithelial cells from bronchial brushes and nasal biopsies, and analyzed by microarray (Affymetrix U133+ PM Genechip Array).