To evaluate the expression and location of epithelial sodium channels (ENaCs) in human nasal polyp and normal nasal mucosa, and to characterize the relevance of ENaCs to the development of NPs. Nasal polyp tissue from 17 patients and nasal mucosa from ten patients were obtained through endoscopic sinus surgery. The mRNA concentrations of ENaC-α, β, and γ were detected by real-time polymerase chain reaction. The expression of ENaC-α was detected using western blot and immunofluorescence techniques. The distribution of ENaC-α in mucosal tissue was observed using a laser scanning confocal microscope. The transcriptional expression of three subunits of ENaC was in the following order: α > β > γ, in both groups. The transcriptional expression of α, β, and γ subunits of ENaC was elevated in nasal polyp compared to nasal mucosa (p < 0.01). ENaC-α expression was higher in nasal polyp than in nasal mucosa (p < 0.05). Immunofluorescent staining indicated that ENaC-α protein was distributed in the epithelial cell apical membrane. The expression of ENaC is upregulated in human nasal polyp, which might in turn facilitate the formation and development of nasal polyp.
Keywords: ENaC-mediated absorption; Epithelial cells; Epithelial sodium channel; Nasal polyp.