15-Lipoxygenase-1 Mediates Mucociliary Differentiation in Normal Human Nasal Epithelial Cells

ABSTRACT

BACKGROUND AND OBJECTIVES: 15-lipoxygenase-1 (15-LO-1) is involved in the differentiation of human tracheobronchial epithelial cells. Here we investigated the relation between 15-LO-1 expression and the differentiation of normal human nasal epithelial (NHNE) cells. MATERIALS AND METHODS: NHNE cells, RT-PCR, Western blot analysis, and scanning electron microscopy (SEM) were used. RESULTS: In retinoic acid (RA)-sufficient culture media, 15-LO-1 expression in NHNE cells increased time-dependently, but its expression was undetectable in RA-deficient culture media. Moreover, in RA-deficient culture media, IL-4 time-dependently induced 15-LO-1 expression at a concentration of 1 ng/mL. In addition, MUC8 gene expression, a marker of mucociliary differentiation, was up-regulated by 15-LO-1, which was itself induced by IL-4. In SEM, the ciliated epithelium was observed with the treatment of IL-4. CONCLUSION: Our findings suggest that 15-LO-1 may be related to the differentiation of human nasal epithelium, and that it may mediate the mucociliary differentiation of NHNE cells.