Objectives: Eosinophilic chronic rhinosinusitis (ECRS) is considered a refractory and intractable disease with thick mucus production, long-term nasal congestion, loss of sense of smell and intermittent acute exacerbations secondary to bacterial infections. In this study, we investigated which growth factor is deeply involved in the mucin overproduction in ECRS.
Method: We employed fluorescence immunohistochemical analysis to evaluate whether or not TGF-α expression was upregulated in the nasal tissue of ECRS patients. We also examined MUC5AC transcription using a luciferase reporter plasmid in HM3-MUC5AC cells and A549 cells in order to assess the role of TGF-α in human epithelial cells.
Results: TGF-α immunoreactivity was found markedly increased in the submucosal tissue in the ECRS patient compared with that of a normal patient and with noneosinophilic CRS. TGF-α synergized with TNF-α to upregulate MUC5AC expression in human epithelial cells through the ERK signaling pathway.
Conclusion: Our results demonstrated that TGF-α was highly expressed in the upper airway tract in ECRS patients and is deeply involved in mucus hypersecretion.
Copyright © 2011 S. Karger AG, Basel.