Background and Objectives:In chronic bronchitis, rhinitis or cystic fibrosis, the number of goblet cells increases along
with hypertrophy of mucous cells in submucosal gland, resulting ineffective mucociliary clearance. But, it is still not fully
understood what role each gene plays in producing airway secretions. This study aimed to figure out which mucin gene is
expressed in the epithelium of normal human nasal mucosa and nasal polyps, and to verify whether the epithelium of nasal
polyp itself contributes to the increased nasal secretion as in chronic sinusitis with nasal polyp. Materials and Methods:
Normal nasal epithelial cells were obtained from the inferior turbinates of ten normal healthy volunteers, and nasal polyps
from six patients who underwent sinus surgery. The epithelial cells were enzymatically isolated, and intracellular levels of
mucin and lysozyme were measured from cell lysates using immunoblot assay. And, RT-PCR was used for the detection of
mucin mRNA and lysozyme mRNA. Results:The level of intracellular mucin was 2.9 times higher in the epithelium of
nasal polyp, and this was statistically significant. Among seven mucin genes (MUC1, 2, 4, 5AC, 5B, 7, 8) expressed in the
epithelium of normal inferior turbinate and polyps, MUC2 and MUC8 were more strongly expressed in the epithelium of
nasal polyp than those of normal inferior turbinate. Conclusion:This results suggest that the polyp epithelium itself is
contributing to increased secretion in chronic sinusitis, and MUC2 and MUC8 are thought to be responsible for this change.
However, further study is required to uncover the full sequence of MUC8 mRNA and its exact function. (Korean J Otolaryngol 2000;43:377-82)