Fig. 3

Overview of the key genes and epigenetic regulatory mechanisms associated with asthma in airway epithelial cells. Environmental insults (e.g. allergens or viruses) may damage the integrity of airway epithelial cells. Some of the susceptibility genes expressed in the airway epithelial cells (e.g. ADAM33) may further deteriorate this structural damage through the process of epithelial–mesenchymal trophic unit (EMTU) and hence encouraging airway remodelling and hyper-responsiveness. Whereas other asthma susceptibility genes (e.g. IRAKM) may promote (Th2)-immunity result in activation of inflammatory responses. Some of the genes have more protective roles (e.g. SPINK5 and TSLP). Furthermore, epigenetic regulatory mechanisms may affect some of these genes (e.g. hyper-methylation of ADAM33, and HLA-G suppression by miRNAs)