[Expression of heme oxygenase-1 in nasal polyps and regulation by glucocorticoid]

To evaluate the expression and possible modulation of heme oxygenase-1 (HO-1) in nasal polyps of patients with chronic rhinosinusitis with nasal polyps (CRSwNP).

Nasal polyps and uncinate process tissues were collected from 25 CRSwNP patients and 19 healthy controls with nasal septal deviation. HO-1 expression was examined using qRT-PCR, immunohistochemistric staining and Western blot analysis. Moreover, additional uncinate process mucosal samples of 15 healthy controls with nasal septal deviation were harvested for nasal explant culture experiments. HO-1 expression was measured in cultured nasal explant in response to specific inflammatory and glucocorticoid stimulation. SPSS 20.0 software was used to analyze the data.

The mRNA and protein expression of HO-1 was significantly increased in polyp tissues, 1.220±0.397 in mRNA and 1.409±0.701 in protein, compared with healthy controls 0.464±0.318 in mRNA and 0.017±0.1147 in protein (U=22.00 in mRNA and U=1.00 in protein, both P< 0.05). The immunohistochemical results showed that HO-1 was mainly distributed in the epithelial layer, submucosal glands and inflammatory cells in nasal tissues. Nasal explant culture experiments demonstrated that HO-1 mRNA was upregulated by IL-17A. The HO-1 mRNA level before the stimulation was 1.000, and 17.264±4.275 after the stimulation of 1 ng/ml IL-17A (U=0, P<0.05), 19.128±4.605 after the stimulation of 10 ng/ml IL-17A (U=0, P<0.05), but was significantly suppressed after stimulation with glucocorticoids (dexamethasone, DEX). The mRNA level after the glucocorticoids stimulation was 0.370±0.101 (U=0, P<0.05) and 0.316±0.167 (U=0, P<0.05) respectively. Furthermore, the HO-1 mRNA was inhibited by TGF-β1, the mRNA level was 0.217±0.322 (U=0, P<0.05), 0.070±0.070 (U=0, P<0.05), respectively.

Increased HO-1 expression may play a role in the pathogenesis of CRSwNP, which may be considered as the therapeutic target.