Local tissue hypoxia and formation of nasal polyps

OBJECTIVE: To explore the response of nasal mucosa epithelial cells to hypoxia in terms of formation of nasal polyps (NP). METHODS: Epithelial cells of NP and inferior turbinate (IT) were cultured serum-free under normal oxygen and hypoxic circumstances with stimulation of IL-1 beta and TNF alpha. The vascular endothelial growth factor (VEGF) mRNA and VEGF protein levels of the cultured cells were detected using in situ hybridization and ELISA, respectively. RESULTS: The expression of VEGF mRNA was significantly higher in epithelial cells of NP than in IT exposed to pro-inflammatory cytokines or hypoxia (P < 0.01). VEGF levels were higher in NP epithelial cells than those of IT (P < 0.01) under hypoxia. CONCLUSION: VEGF-induced by hypoxia is very important for the early stages of forming polyps.