Genome-Wide Methylation Study Identifies an IL-13-induced Epigenetic Signature in Asthmatic Airways.

Rationale: Epigenetic changes to airway cells have been proposed as important modulators of the effects of environmental exposures on airway diseases, yet no study to date has shown epigenetic responses to exposures in the airway that correlate with disease state. The type 2 cytokine IL-13 is a key mediator of allergic airway diseases, such as asthma, and is up-regulated in response to many asthma-promoting exposures.Objectives: To directly study the epigenetic response of airway epithelial cells (AECs) to IL-13 and test whether IL-13–induced epigenetic changes differ between individuals with and without asthma.Methods: Genome-wide DNA methylation and gene expression patterns were studied in 58 IL-13–treated and untreated primary AEC cultures and validated in freshly isolated cells of subjects with and without asthma using the Illumina Human Methylation 450K and HumanHT-12 BeadChips. IL-13–mediated comethylation modules were identified and correlated with clinical phenotypes using weighted gene coexpressi...