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-1β and TNFα. 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.