Conclusions: This study indicates that MUC8 protein is expressed in ciliated cells from human nasal epithelial cells and is upregulated by IL-1beta treatment. These results suggest that MUC8 gene and protein expression levels could be used as a ciliated cell marker in human nasal epithelium.
Objectives: To examine MUC8 mRNA expression patterns according to the mucociliary differentiation of normal human nasal epithelial (NHNE) cells, and to investigate the localization of MUC8 proteins in nasal polyps.
Material and methods: Passage-2 NHNE cells were cultured using an air-liquid interface technique. On Days 2, 7, 14 and 28 after confluence, ciliated cells were counted by means of cytospin slide immunostaining using H6C5 and beta-tubulin, and MUC8 mRNA levels were determined using real-time quantitative polymerase chain reaction (PCR). After synthesizing polyclonal anti-MUC8 peptide antibodies, MUC8 immunostaining was performed using nasal polyps. MUC8 mRNA and protein levels were determined in NHNE cells treated with IL-1beta (10 ng/ml for 24 h) using reverse transcriptase-PCR and Western blot analysis.
Results: The increases in the number of ciliated cells and the MUC8 gene expression level with increasing culture time in the NHNE cells were quite similar. MUC8 was expressed in the ciliated cells of human nasal polyps. The MUC8 protein level and the mRNA level were upregulated as a result of IL-1beta treatment.