ABSTRACT
PURPOSE: Periostin was originally identified as a secreted factor during screening of a mouse osteoblastic library. In a recent study, periostin was found to directly regulate eosinophil accumulation in allergic mucosal inflammation. Chronic eosinophilic inflammation is related to the development of remodeling. The present study examined the expression of periostin and evaluated its role in the inflammatory process and remodeling associated with allergic rhinitis. METHODS: A murine model of allergic rhinitis was established in periostin knockout mice. We analyzed the expression of periostin, manifestation of nasal symptoms, eosinophilic inflammation, and subepithelial fibrosis as well as the expression of MMP-2, TIMP-1, and type 1 collagen in nasal tissue. RESULTS: Periostin was mainly distributed in the subepithelial tissue of the nasal mucosa. The subepithelial tissue was thinner in the knockout group than in the control group. No differences in the expression of MMP-2 or TIMP-1 were found in the knockout group. However, after a month of allergen challenge, type I collagen in the nasal tissue was lower in the knockout group than in the control group. The number of eosinophils and the symptom score were also lower in the knockout group. CONCLUSIONS: Periostin is expressed in nasal tissues of murine models of allergic rhinitis. Periostin deficiency may affect the remodeling of nasal tissue with reduced subepithelial fibrosis, and lead to less eosinophilic inflammation.