Background: Heparanase (HPA) is known to be involved in tissue remodeling of various organs with inflammatory diseases. The aim of this study was to investigate the level of expression and the pattern of distribution of HPA in normal human sinus mucosa, inflammatory sinus mucosa, and nasal polyps to evaluate the possible effect of HPA on the tissue remodeling of chronic inflammatory sinus mucosa and nasal polyps.
Methods: Normal sinus mucosa was obtained from the ethmoid sinus during endoscopic reduction in 25 patients with blowout fractures. Inflammatory sinus mucosa and nasal polyps were obtained from 25 patients undergoing endoscopic sinus surgery for chronic sinusitis with nasal polyps. The levels of expression and the pattern of distribution of HPA were evaluated in normal human sinus mucosa, inflammatory sinus mucosa, and nasal polyps, using reverse transcriptase-polymerase chain reaction, immunohistochemical analysis, and Western blot analysis.
Results: HPA mRNA and protein were detected in inflammatory sinus mucosa and nasal polyps but not in normal sinus mucosa. HPA was mainly localized in the vascular endothelium, epithelium, submucosal glands, and inflammatory cells of inflammatory sinus mucosa. In nasal polyps, inflammatory cells and vascular endothelium showed immunopositivity in the entire portion, whereas glands and epithelial cells did not show positivity.
Conclusion: Our results indicate that HPA is not constitutively expressed in normal sinus mucosa and is upregulated in chronic inflammatory sinus mucosa and nasal polyps, suggesting that HPA may play an important role in the tissue remodeling in chronic sinusitis.