LAUSR

Airway remodeling happens in childhood asthma, in parallel with, but not necessarily subsequent to, airway inflammation. The differentiation of airway epithelial cells into myofibroblasts via epithelial-mesenchymal-transition (EMT) is one of the mechanisms underlying airway remodeling. This study aimed at identifying novel molecules involved in pediatric asthma-associated airway remodeling. Asthma model was established by challenging C57BL/6 mouse pups with ovalbumin (OVA). We found that the expression of Cadherin 11 (CDH11), a type II cadherin, was increased by OVA treatments in the airway epithelium. Our earlier microarray data suggested miRNA-451a-5p (miRNA-451a) as a potential regulator of CDH11. In contrast to CDH11, miRNA-451a expression decreased in the asthmatic lung. MiRNA-451a was then packaged into a lentivirus vector and systematically given to the asthmatic pups. Our data indicated that OVA-induced infiltration of inflammatory cells, including eosnophils, neutrophils, macrophages and lymphocytes, was reduced by miRNA-451a over-expression. EMT was initiated in asthmatic mice as demonstrated by increased alpha-smooth muscle actin (α-SMA) positive cells present in airway epithelium, which was inhibited by miRNA-451a. CDH11 elevation in vivo was also inhibited by miRNA-451a. Dual-Luciferase analysis further showed CDH11 as a novel valid target of miRNA-451a. Additionally, in vitro, EMT was triggered in human 16HBE airway epithelial cells by pro-fibrotic transforming growth factor β (TGF-β). Corresponding to the anti-EMT effects observed in vivo, miRNA-451a also inhibited TGF-β-induced collagen deposition in cultured airway epithelial cells by targeting in CDH11. In summary, our study demonstrates that the deregulated miRNA-451a-CDH11 axis contributes to airway remodeling in childhood asthma.