Interleukin-13 Suppresses MUC5AC Gene Expression and Mucin Secretion in Cultured Normal Human Nasal Epithelial Cells

Lee, Jeung Gweon; Kim, Chang Hoon; Kim, Hyun Ung; Choi, Jae Young; Bae, Jungho; Yoon, Joo Heon

Abstract

BACKGROUND AND OBJECTIVES: It is not clear which mucins are responsible for the mucus hypersecretion in allergic rhinitis and allergic asthma. Recently, it was found that IL-13 is closely related to allergic inflammation and mucus hypersecretion in in vivo animal models. However, the role of IL-13 in in vitro cellular models has yet to be determined. This study aimed to investigate the direct effect of IL-13 on mucin gene expression and mucin secretion in cultured normal human nasal epithelial cells. MATERIALS AND METHOD: Cells were cultured with passage-2 normal human nasal epithelial cells using the air-liquid interface culture method. After treatment with IL-13, the total mucin and MUC5AC mucin levels were measured using the immuno-blotting assay. The MUC2, MUC5AC, and MUC8 mRNA expressions were measured using RT-PCR. Immunostaining was also performed using a MUC5AC antibody on histologic and cytospin slides.
RESULTS
After treatment with 5 ng/ml or more of IL-13, the level of total mucin and MUC5AC mucin secretion decreased substantially. The expression of MUC2 and MUC8 mRNA increased with higher concentrations of IL-13, but the expression of MUC5AC mRNA decreased. On the 7th day after IL-13 treatment, a significant decrease in the number of MUC5AC-positive cells was confirmed with immunostaining.
CONCLUSION
These findings indicate that IL-13 suppresses MUC5AC mucin gene expression and mucin secretion in cultured normal human nasal epithelial cells in vitro.