Ultrastructural Changes of Cultured Human Nasal Epithelial Cells by Tumor Necrosis Factor-a

BACKGROUND: Tumor necrosis factor(TNF)-alpha plays a critical role in normal host resistance to infections and to the growth of malignant tumor. Among its actions, the induction of the cytokines and the involved factors in the inflammatory reaction is the most important action of TNF-alpha. Until now, the functional role of TNF-alpha has been intensively studied, but the morphological effects on epithelial cells by it was not. OBJECTIVES: The aim of this study was to observe the ultrastructural changes of cultured human nasal epithelial cell(HNEC) by TNF-alpha. MATERIALS AND METHODS: The HNEC culture was done as floating method and the epithelial cells on the floating 14th day were cultured in the culture media containing TNF-alpha(0.1, 1, 10, 100ng/ml) for 48 hours. The observation was done with scanning electron microscopy(SEM) and transmission electron microscopy. For the quantitation of area of ciliated and secretory epithelial cells, SEM photo(1000 magnification) was taken and each area per 60nm 2 was calculated. RESULTS: The ultrastructural changes were observed from 1 ng/ml through 100 ng/ml TNF-alpha and the changes(damage of cilia, increase of mitochondria, intracellular vacuole, increase of intercellular space and the increase of secretory epithelial cell area) were similar to the inflammatory changes in vivo. CONCLUSION: These results suggest that the ultrastructural changes of culture HNECs are induced by TNF-alpha. The study on the reversibility of the changes and the estimation of size and numbers of cells with be required.ope