Project description:We performed a pooled GWAS and individual genotyping in 269 children with allergic respiratory diseases comparing allergic children with and without asthma. We used a modular approach to identify the most significant loci associated with asthma by combining silhouette statistics and physical distance method with cluster-adapted thresholding. We found 97% concordance between pooled GWAS and individual genotyping, with 36 out of 37 top-scoring SNPs significant at individual genotyping level. The most significant SNP is located inside the coding sequence of C5, an already identified asthma susceptibility gene, while the other loci regulate functions that are relevant to bronchial physiopathology, as immune- or inflammation-mediated mechanisms and airway smooth muscle contraction. Integration with gene expression data (from mouse experimental asthma model taken from GSE6858 and GSE1301) showed that almost half of the putative susceptibility genes are differentially expressed in experimental asthma mouse models.
Project description:We performed a pooled GWAS and individual genotyping in 269 children with allergic respiratory diseases comparing allergic children with and without asthma. We used a modular approach to identify the most significant loci associated with asthma by combining silhouette statistics and physical distance method with cluster-adapted thresholding. We found 97% concordance between pooled GWAS and individual genotyping, with 36 out of 37 top-scoring SNPs significant at individual genotyping level. The most significant SNP is located inside the coding sequence of C5, an already identified asthma susceptibility gene, while the other loci regulate functions that are relevant to bronchial physiopathology, as immune- or inflammation-mediated mechanisms and airway smooth muscle contraction. Integration with gene expression data (from mouse experimental asthma model taken from GSE6858 and GSE1301) showed that almost half of the putative susceptibility genes are differentially expressed in experimental asthma mouse models. Affymetrix SNP arrays (Mapping 250K NspI and StyI) were performed according to the manufacturer's directions on pooled DNA extracted from peripheral blood samples.The design is a pooled-GWAS. DNA samples were assigned to the Asthma group if displaying symptoms of asthma, alone or associated to other allergic phenotypes, including rhinoconjunctivitis (RC), and assigned to the RC group if displaying rhinitis or rhinoconjunctivits alone or associated to other allergic phenotypes, excluding asthma. Each of the two groups was subdiveded into 4 independent groups of samples, each containing 31-36 individuals. Individual DNA samples were then added to their respective pools in equivalent molar amounts. Each pool was labeled and hybridized independently on three different arrays (3 technical replicates for each pool).
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:There are marked socioeconomic disparities in pediatric asthma control. To identify the molecular origins of these disparities, we performed genome-wide expression profiling of monocytes and T-helper cells isolated from pediatric asthma patients of lower- and higher socioeconomic status (SES).
Project description:Background: Microbial interventions against allergic asthma have robust epidemiologic underpinnings and the potential to recalibrate disease-inducing immune responses. Oral administration of OM-85, a standardized lysate of human airways bacteria, is widely used empirically to prevent respiratory infections, and a clinical trial is testing its ability to prevent asthma in at-risk children. On the other hand, we previously showed that intra-nasal administration of products from microbe-rich farm environments abrogate experimental allergic asthma. Objectives: To investigate whether direct administration of OM-85 to the airway compartment protects against experimental allergic asthma, and to identify protective cellular and molecular mechanisms activated through this natural route. Methods: BALB/cJ mice (7-8 weeks old) sensitized and challenged with Ovalbumin received OM-85 intra-nasally, and cardinal cellular and molecular asthma phenotypes were measured. Murine lung gene expression was profiled by RNA-sequencing. Results: Airway administration of OM-85 suppressed allergic asthma and altered the transcriptome profile in unfractionated lung tissue. Conclusion We provide the first demonstration that administration of a standardized bacterial lysate to the airway compartment protects from experimental allergic asthma by engaging multiple immune pathways.
Project description:To gain insight into the promoting effect of ultrafine particle inhalation on development and progression of allergic asthma, we selected an experimental approach involving exposure to ultrafine carbon particles (UCP) and gene expression profiling of lungs from mice with experimental, ovalbumin induced allergy. Comparative gene expression analysis was performed by hybridizing pooled cDNA samples from lavaged lungs of different groups. The results suggest that allergic sensitization may represent an susceptibility factor for effects of UCP on gene expression in the lung. In sensitized individuals UCP exposure, such as found in polluted air, thus may contribute to the development and/or aggrevation of allergic asthma. Keywords: Particle Inhalation, lung, ovalbumin sensitized and challanged, expression profling
Project description:To gain insight into the promoting effect of ultrafine particle inhalation on development and progression of allergic asthma, we selected an experimental approach involving exposure to ultrafine carbon particles (UCP) and gene expression profiling of lungs from mice with experimental, ovalbumin induced allergy. Comparative gene expression analysis was performed by hybridizing pooled cDNA samples from lavaged lungs of different groups. These results suggest that allergic sensitization may represent a susceptibility factor for effects of UCP on gene expression in the lung. In sensitized individuals UCP exposure, such as found in polluted air, thus may contribute to the development and /or aggravation of allergic asthma. Keywords: Particle Inhalation, lung, ovalbumin sensitzed and challanged, experssion profiling
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:Background: Nasal epithelia are emerging as a proxy measure of gene expression of the airway epithelium in asthma. We hypothesized that epigenetic marks regulate gene expression of the nasal epithelia and consequently may provide a novel target for allergic asthma. Methods: We compared genomic DNA methylation patterns and gene expression in African American children with persistent atopic asthma [N=36] versus healthy controls [N=36]. Results were validated in an independent population of asthmatics [N=30]. Results: We identified 186 genes with significant methylation changes, either as regions (differentially methylated regions [DMRs]) or single CpGs (differentially methylated probes [DMPs]) after adjustment for age, gender, race/ethnicity, batch effects, inflation, and multiple comparisons (false discovery rate-adjusted q<0.05). Genes differentially methylated include those with established roles in asthma and atopy, components of the extracellular matrix, genes related to immunity, cell adhesion, epigenetic regulation, and airway obstruction. The methylation changes are large (median 9.5%, range: 2.6-29.5% methylation change) and similar in magnitude to those observed in malignancies. Hypo- and hyper-methylated genes were associated with increased and decreased gene expression respectively (P<2.8x10-6 for DMRs and P<7.8x10-10 for DMPs). Quantitative analysis of methylation-expression relationships in 53 differentially expressed genes demonstrated that 32 (60%) have significant (q<0.05) methylation-expression relationships within 5kb of the gene. 10 loci selected based on the relevance to asthma, magnitude of methylation change, and asthma specific methylation-expression relationships were validated in an independent cohort of children with asthma. Conclusions: Our findings that epigenetic marks in respiratory epithelia are associated with allergic asthma in inner-city children provide new targets for biomarker development, and novel approaches to understanding disease pathogenesis. case control design with nasal epithelial cells from 36 atopic asthmatic and 36 nonatopic nonasthmatic children from the inner city
Project description:This study aims to demonstrate the link between epigenome-wide methylation aberrations at birth and genomic transcriptional changes upon allergen sensitization that occur in the neonatal dendritic cells (DC) due to maternal asthma. In an in vivo model reproducing human epidemiology findings, maternal but not paternal asthma predisposes the neonate to increased asthma risk, the effect is allergen-independent and is not genetic or environmental. Earlier we demonstrated that neonates of asthmatic mothers are born with a functional skew in splenic DCs that mediates the early-life asthma origin. These allergen-naive cells convey allergy responses to normal recipients, however minimal to no transcriptional or phenotypic changes were found to explain the functional pro-allergic alterations. In this study we profiled both allergen-naïve dendritic cells, and cells after allergen sensitization in vivo. We found that while allergen-naive DCs from asthma-at-risk neonates have minimal transcriptional change compared to controls, upon allergen sensitization, multiple genes with pre-existing epigenetic alterations show significant transcriptional change. . 24 samples from 2 batches, 3-4 replicates in each of 4 groups