Project description:Background: Epigenetic marks, like asthma, are heritable. They are influenced by the environment, direct the maturation of T cellslymphocytes, and have been shown to enhance the development of allergic airways disease in mice. Thus, we hypothesized that epigenetic marks are associated with allergic asthma in inner-city children. Methods: We compared methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy controls, using DNA and RNA from peripheral blood mononuclear cells (PBMCs) from inner city children aged 6-12 years with persistent atopic asthma children and healthy controls. Results were externally validated with the GABRIELA study population. Results: Comparing asthmatics (N=97) to controls (N=97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthmatics, including IL-13, RUNX3, and a number of specific genes relevant to natural killer cells (KIR2DL4, KIR2DL3, KIR3DL1, and KLRD1) and T cells lymphocytes (TIGIT). 14 differentially methylated regions (DMRs) were associated with the serum IgE concentration of IgE, including RUNX3. These results were internally and externally validated with a global methylation assessment using a different methodology in our inner-city cohort and an independent European cohort (GABRIELA). Hypo- and hypermethylated genes tended to be associated with increased and decreased gene expression, respectively (P<0.6x10-11 for asthma and ; P<0.01 for IgE). To further explore the relationship between methylation and gene expression, we created a matrix of genomic changes in methylation versus transcriptional changes (methyl eQTL) for asthma, and identified cis- and trans-regulated genes whose expression was related to asthma asthma-associated methylation marks.
Project description:Background: Epigenetic marks, like asthma, are heritable. They are influenced by the environment, direct the maturation of T cellslymphocytes, and have been shown to enhance the development of allergic airways disease in mice. Thus, we hypothesized that epigenetic marks are associated with allergic asthma in inner-city children. Methods: We compared methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy controls, using DNA and RNA from peripheral blood mononuclear cells (PBMCs) from inner city children aged 6-12 years with persistent atopic asthma children and healthy controls. Results were externally validated with the GABRIELA study population. Results: Comparing asthmatics (N=97) to controls (N=97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthmatics, including IL-13, RUNX3, and a number of specific genes relevant to natural killer cells (KIR2DL4, KIR2DL3, KIR3DL1, and KLRD1) and T cells lymphocytes (TIGIT). 14 differentially methylated regions (DMRs) were associated with the serum IgE concentration of IgE, including RUNX3. These results were internally and externally validated with a global methylation assessment using a different methodology in our inner-city cohort and an independent European cohort (GABRIELA). Hypo- and hypermethylated genes tended to be associated with increased and decreased gene expression, respectively (P<0.6x10-11 for asthma and ; P<0.01 for IgE). To further explore the relationship between methylation and gene expression, we created a matrix of genomic changes in methylation versus transcriptional changes (methyl eQTL) for asthma, and identified cis- and trans-regulated genes whose expression was related to asthma asthma-associated methylation marks. peripheral blood mononuclear cells (PBMCs) from 97 atopic asthmatic and 97 nonatopic nonasthmatic children
Project description:Background: Epigenetic marks, like asthma, are heritable. They are influenced by the environment, direct the maturation of T cellslymphocytes, and have been shown to enhance the development of allergic airways disease in mice. Thus, we hypothesized that epigenetic marks are associated with allergic asthma in inner-city children. Methods: We compared methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy controls, using DNA and RNA from peripheral blood mononuclear cells (PBMCs) from inner city children aged 6-12 years with persistent atopic asthma children and healthy controls. Results were externally validated with the GABRIELA study population. Results: Comparing asthmatics (N=97) to controls (N=97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthmatics, including IL-13, RUNX3, and a number of specific genes relevant to natural killer cells (KIR2DL4, KIR2DL3, KIR3DL1, and KLRD1) and T cells lymphocytes (TIGIT). 14 differentially methylated regions (DMRs) were associated with the serum IgE concentration of IgE, including RUNX3. These results were internally and externally validated with a global methylation assessment using a different methodology in our inner-city cohort and an independent European cohort (GABRIELA). Hypo- and hypermethylated genes tended to be associated with increased and decreased gene expression, respectively (P<0.6x10-11 for asthma and ; P<0.01 for IgE). To further explore the relationship between methylation and gene expression, we created a matrix of genomic changes in methylation versus transcriptional changes (methyl eQTL) for asthma, and identified cis- and trans-regulated genes whose expression was related to asthma asthma-associated methylation marks.
Project description:Background: Epigenetic marks, like asthma, are heritable. They are influenced by the environment, direct the maturation of T cellslymphocytes, and have been shown to enhance the development of allergic airways disease in mice. Thus, we hypothesized that epigenetic marks are associated with allergic asthma in inner-city children. Methods: We compared methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy controls, using DNA and RNA from peripheral blood mononuclear cells (PBMCs) from inner city children aged 6-12 years with persistent atopic asthma children and healthy controls. Results were externally validated with the GABRIELA study population. Results: Comparing asthmatics (N=97) to controls (N=97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthmatics, including IL-13, RUNX3, and a number of specific genes relevant to natural killer cells (KIR2DL4, KIR2DL3, KIR3DL1, and KLRD1) and T cells lymphocytes (TIGIT). 14 differentially methylated regions (DMRs) were associated with the serum IgE concentration of IgE, including RUNX3. These results were internally and externally validated with a global methylation assessment using a different methodology in our inner-city cohort and an independent European cohort (GABRIELA). Hypo- and hypermethylated genes tended to be associated with increased and decreased gene expression, respectively (P<0.6x10-11 for asthma and ; P<0.01 for IgE). To further explore the relationship between methylation and gene expression, we created a matrix of genomic changes in methylation versus transcriptional changes (methyl eQTL) for asthma, and identified cis- and trans-regulated genes whose expression was related to asthma asthma-associated methylation marks. peripheral blood mononuclear cells (PBMCs) from 97 atopic asthmatic and 97 nonatopic nonasthmatic children
Project description:Epigenetic marks are heritable, influenced by the environment, direct the maturation of T lymphocytes, and in mice enhance the development of allergic airway disease. Thus it is important to define epigenetic alterations in asthmatic populations.We hypothesize that epigenetic alterations in circulating PBMCs are associated with allergic asthma.We compared DNA methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy control subjects by using DNA and RNA from PBMCs. Results were validated in an independent population of asthmatic patients.Comparing asthmatic patients (n = 97) with control subjects (n = 97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthma, including IL13, RUNX3, and specific genes relevant to T lymphocytes (TIGIT). Among asthmatic patients, 11 differentially methylated regions were associated with higher serum IgE concentrations, and 16 were associated with percent predicted FEV1. Hypomethylated and hypermethylated regions were associated with increased and decreased gene expression, respectively (P < 6 × 10(-12) for asthma and P < .01 for IgE). We further explored the relationship between DNA methylation and gene expression using an integrative analysis and identified additional candidates relevant to asthma (IL4 and ST2). Methylation marks involved in T-cell maturation (RUNX3), TH2 immunity (IL4), and oxidative stress (catalase) were validated in an independent asthmatic cohort of children living in the inner city.Our results demonstrate that DNA methylation marks in specific gene loci are associated with asthma and suggest that epigenetic changes might play a role in establishing the immune phenotype associated with asthma.
Project description:Genomewide DNA methylation profiling of nasal DNA from control and asthmatic children. Methylation profiles were generated by the Illumina Infinium HumanMethylation450 beadchips.
Project description:BackgroundChildren with asthma in low-income urban areas have high morbidity. Phenotypic analysis in these children is lacking, but may identify characteristics to inform successful tailored management approaches.ObjectiveWe sought to identify distinct asthma phenotypes among inner-city children receiving guidelines-based management.MethodsNine inner-city asthma consortium centers enrolled 717 children aged 6 to 17 years. Data were collected at baseline and prospectively every 2 months for 1 year. Participants' asthma and rhinitis were optimally managed by study physicians on the basis of guidelines. Cluster analysis using 50 baseline and 12 longitudinal variables was performed in 616 participants completing 4 or more follow-up visits.ResultsFive clusters (designated A through E) were distinguished by indicators of asthma and rhinitis severity, pulmonary physiology, allergy (sensitization and total serum IgE), and allergic inflammation. In comparison to other clusters, cluster A was distinguished by lower allergy/inflammation, minimally symptomatic asthma and rhinitis, and normal pulmonary physiology. Cluster B had highly symptomatic asthma despite high step-level treatment, lower allergy and inflammation, and mildly altered pulmonary physiology. Cluster C had minimally symptomatic asthma and rhinitis, intermediate allergy and inflammation, and mildly impaired pulmonary physiology. Clusters D and E exhibited progressively higher asthma and rhinitis symptoms and allergy/inflammation. Cluster E had the most symptomatic asthma while receiving high step-level treatment and had the highest total serum IgE level (median, 733 kU/L), blood eosinophil count (median, 400 cells/mm3), and allergen sensitizations (15 of 22 tested).ConclusionsAllergy distinguishes asthma phenotypes in urban children. Severe asthma often coclusters with highly allergic children. However, a symptomatic phenotype with little allergy or allergic inflammation was identified.
Project description:AIM:We aim to study DNA methylation (DNAm) variations associated with childhood asthma. METHODS:Nasal DNAm was compared between sibling pairs discordant for asthma, 29 sib pairs for genome-wide association studies and 54 sib pairs for verification by pyrosequencing. Associations of methylation with asthma symptoms, allergy and environmental exposures were evaluated. In vitro experiments and functional genomic analyses were performed to explore biologic relevance. RESULTS:Three CpGs were associated with asthma. cg14830002 was associated with allergies in nonasthmatics. cg23602092 was associated with asthma symptoms. cg14830002 and cg23602092 were associated with traffic-related air pollution exposure. Nearby genes were transcriptionally regulated by diesel exhaust, house dust mite and 5-aza-2'-deoxycytidine. Active chromatin marks and transcription factor binding were found around these sites. CONCLUSION:We identified novel DNAm variations associated with childhood asthma and suggested new disease-contributing epigenetic mechanisms.
Project description:BACKGROUND:Genetic variation in the ?-2 adrenergic receptor gene (ADRB2) has been implicated in asthma severity and control with conflicting results. Epigenetic variation in the ADRB2 may play an important role in asthma phenotype. OBJECTIVE:We aimed to evaluate whether DNA methylation of ADRB2 is associated with asthma phenotypes in inner-city school-aged children. METHODS:Multiple CpG sites in the promoter region of ADRB2 gene were analysed in 177 children enrolled in the School Inner-City Asthma Study. Blood- or saliva-derived DNA was measured by bisulphite-polymerase chain reaction pyrosequencing assay. Average percentage DNA methylation across the sites was evaluated for association with asthma severity (report of dyspnoea, night-time symptoms, rescue medication use, and baseline spirometry) and morbidity (school absences and unscheduled healthcare visits). Three clades composed of highly correlated methylation sites within the methylated segment of ADRB2 were further analysed. RESULTS:Methylation of individual sites generally ranged from 0% to 6% with average percentage methylation across sites of 2.4%. Univariate analyses strongly favoured the association of higher percentage methylation with lower asthma severity measured by report of dyspnoea. Furthermore, there was a non-significant trend towards less rescue medication use, night-time symptoms, school absences, activity limitation due to asthma, and improved lung function measurements with increased methylation. Multivariate analysis demonstrated methylation of ADRB2 gene significantly associated with less dyspnoea (odds ratio (OR) 0.2, 95% confidence interval (CI), 0.1-0.6, P = 0.002). Each of the three clades of methylation sites showed a strong, but not statistically significant, effect on decreased dyspnoea. CONCLUSIONS AND CLINICAL RELEVANCE:DNA methylation in the ADRB2 gene is associated with decreased asthma symptom severity, suggesting a role for methylation in asthma phenotypes.