Objective: To evaluate the expression of epithelial sodium channel in nasal polyps and normal nasal mucosa and to characterize the ENaC-mediated Na(+) absorption and the mechanism of the liquid transport in human upper airway epithelia.
Methods: The tissue from 12 patients with nasal polyps (NP) and the normal ethmoid cornu mucosa (ECM) from 5 patients were obtained through endoscopic surgery. The expression of ENaC was detected by Immunofluorescence and the concentration of ENaC alpha, beta, gamma-mRNA were detected by RT real-time PCR.
Results: The ENaC in NP group (35.79 +/- 5.47) was higher than that in ECM group (22.17 +/- 5.43, t = 4.687, P < 0.01). The expression of ENaC-alpha, beta, gamma mRNA in NP group (respectively 2.06 +/- 0.42, 1.97 +/- 0.32, 1.96 +/- 0.54) was higher than that in ECM group (respectively 1.01 +/- 0.10, 0.98 +/- 0.08, 0.97 +/- 0.06; t = 5.482, 6.659, 4.036, all P < 0.01). The mRNA expression of three subunits of ENaC was as follows: alpha > beta > gamma in both groups. The mRNA expression of alpha, beta, gamma subunit of ENaC in NP group was higher than that in ECM group(P < 0.01). The expression of three subunits of ENaC was correlated respectively with that of mRNA in NP group.
Conclusions: The up-regulation of ENaC in human NP was associated with the expression of ENaC mRNA, that made hydrops and might be one of the most important cause of the develop of nasal polyp.