Roles of vascular endothelial growth factor, Angiopoietin 1, and Angiopoietin 2 in nasal polyp.

OBJECTIVES/HYPOTHESIS: To determine the roles of vascular endothelial growth factor (VEGF), Angiopoietin (Ang)-1, and Ang-2 in nasal polyps (NPs) by assaying expression patterns and evaluating the effects of dexamethasone (DEX) on these factors in organ cultured NPs.

STUDY

DESIGN

Prospective.

METHODS

Expression patterns of VEGF, Ang-1, and Ang-2 in NPs were compared with those in inferior turbinate mucosa samples. Tissue samples were analyzed using the enzyme-linked immunosorbent assay (ELISA) and immunofluorescent staining methods. To determine the effects of DEX, NP tissues were cultured using an air-liquid interface method. Cultures were maintained in the absence or presence of DEX (10 microM or 100 microM) for 24 hours, and tissue samples analyzed with ELISA.

RESULTS

VEGF and Ang-1 levels were significantly higher, whereas the Ang-2 level was significantly lower in NPs, compared to inferior turbinate mucosa (P < .05). In NPs, VEGF and Ang-1 were detected in glandular epithelial, vascular endothelial, as well as stromal inflammatory cells, whereas Ang-2 was detected only in stromal inflammatory cells. VEGF and Ang-1 levels were significantly lower, while Ang-2 levels were significantly higher in 100 microM DEX-treated group than nontreated group (P < .01).

CONCLUSIONS

Imbalance among VEGF, Ang 1, and Ang 2 may be important in the angiogenesis of NPs. Moreover, DEX can control the expression of these factors in NPs. We suggest that VEGF and Ang-1 act as positive regulatory factors, and Ang-2 functions as a negative regulatory factor of angiogenesis in NPs.