Glucocorticoids ameliorate periostin-induced tissue remodeling in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Periostin plays an important role in the development of chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP). Glucocorticoids (GCs) are anti-inflammatory drugs used to treat CRS, but the mechanism for inhibiting periostin-induced tissue remodeling is still unclear. We sought to investigate the expression of periostin, α-SMA, and extracellular matrix (ECM) components in sinonasal tissues and to evaluate the inhibitory mechanism of GCs in nasal fibroblasts and mucosa.

METHODS: We measured the expression of periostin, α-SMA and ECM components in sinonasal tissues. Correlation of CRS severity and periostin was evaluated by the Lund-Mackey score. Fibroblasts and ex vivo culture of the inferior turbinate were used to investigate the effects of GCs on periostin-induced alterations using real-time PCR, western blot, and immunostaining. Wound healing, transwell invasion, and collagen gel contraction were performed to evaluate migration and collagen contraction.

RESULTS: Periostin was highly expressed in eosinophilic CRSwNP and correlated with the Lund-Mackay score. In nasal fibroblasts, periostin increased tissue remodeling involved protein. GCs suppressed the alterations of periostin. In addition, periostin induced activation of Src/AKT/mTOR, which was inhibited by GCs. GCs also inhibited periostin-induced migration, invasion, and collagen gel contraction.

CONCLUSION: We suggest that GCs are therapeutic agents for CRSwNP by inhibiting tissue remodeling through their inhibitory effect on Src/Akt/mTOR signaling pathway. This article is protected by copyright. All rights reserved.