Objective: To investigate the expression of P-selectin and its mechanism in nasal polyps.
Methods: The expression of P-selectin was detected with immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR) in nasal polyps from 24 patients and nasal epithelium from 9 normals. The production of P-selectin in supernatans of isolated cultured vascular endothelial cells induced by interleukin-5 (IL-5) was detected with enzyme-linked immunosorbent assay (ELISA).
Results: The positive rate of P-selectin in nasal polyps was 79.1% (19/24) while it was 22.2%(2/9) in normals. The relative density ratio of P-selectin and beta-actin were 0.68 +/- 0.11 in nasal polyps and 0.29 +/- 0.08 in normals indicated by RT-PCR and agrose electrophoresis. The concentration of P-selectin was (53.4 +/- 2.9) ng/L and (21.3 +/- 3.5) ng/L in the two groups respectively.
Conclusions: P-selectin upregulated in nasal polyps correlated with the infiltrated eosinophils and IL-5 could induce the expression of P-selectin protein in the isolated cultured endothelial cells. It suggested that upregulation of P-selectin may play a role in the pathogenesis of nasal polyps and can be enhanced by cytokine IL-5.