Expression of pro-angiogenic cytokines and their inhibition by dexamethasone in an ex vivo model of nasal polyps

We used an organ culture of nasal polyps (NP) to provide ex vivo model to study the expression of pro-angiogenic cytokines and the effect of glucocorticoids in the pathogenesis of NP. Glucocorticoids are the drugs of choice for clinical treatment of NP; however, their mechanism of action is not fully understood. The cell-cell and cell-matrix integrity is well maintained in cultured NP. Expression of IL-6, IL-8, bFGF, GRO, and MCP-1 was increased in cultured NP compared to pre-cultured NP. Expression levels of IL-6, bFGF, and GRO in cultured NP were downregulated by dexamethasone (DEX) treatment, while MCP-1 expression was not suppressed. Further, RT-PCR and immunohistochemical analysis showed that HIF-1α and VEGF were suppressed in DEX-treated NP compared to untreated NP. Taken together, these results suggest that ex vivo organ culture can be considered a useful model to study the pathogenesis and regulation of pro-angiogenic cytokines in nasal polypogenesis.