The expression of 11 beta-hydroxysteroid dehydrogenase type 1 and 2 in nasal polyp-derived epithelial cells and its possible contribution to glucocorticoid activation in nasal polyp

Abstract

Background: The actions of glucocorticoids in target tissues depend on the local metabolism of glucocorticoids catalyzed by 11 beta hydroxysteroid dehydrogenase (HSD) 1 and 2. Glucocorticoids are the most effective anti-inflammatory drugs in the treatment of nasal polyps. However, the mechanisms that underlie the anti-inflammatory effects are unclear. Objective: The present study analyzed the expression of 11 beta-HSD1, 11 beta-HSD2, and steroidogenic enzymes (cytochrome P450, family 11, subfamily B, polypeptide 1 [CYP11B1]; cytochrome P450, family 11, subfamily A, polypeptide 1 [CYP11A1]) in nasal polyp tissues, and endogenous cortisol levels in nasal polyp-derived epithelial cells. Methods: The expression levels and distribution pattern of 11 beta-HSD1, 11 beta-HSD2, CYP11B1, and CYP11A1 were determined in nasal polyp tissues or nasal polyp-derived epithelial cells by using real-time polymerase chain reaction, Western blot, and immunohistochemistry testing. The expression levels of cortisol by using enzyme-linked immunosorbent assay were determined in cultured polyp-derived epithelial cells treated with adrenocorticotrophic hormone (ACTH), 11 beta-HSD1 inhibitor, or small interfering ribonucleic acid technique. The effect of glucocorticoids on the expression levels of these enzymes was investigated in cultured cells. Results: Expressed in nasal polyp tissues and nasal polyp-derived epithelial cells were 11 beta-HSD1, 11 beta-HSD2, CYP11B1, and CYP11A1. Cortisol production in cultured epithelial cells was decreased in cells treated with 11 beta-HSD1 small interfering ribonucleic acid or inhibitor, compared with nontreated cells. Cultured cells treated with adrenocorticotropic hormone induced increased cortisol production. 11 beta-HSD1 expression levels were upregulated in cells treated with glucocorticoid. Conclusions: Analysis of these results indicated that 11 beta-HSD1 expressed in polyp-derived epithelial cells may be involved in the anti-inflammatory function of glucocorticoid in the treatment of nasal polyps, which contributes to increased levels of endogenous cortisol.