Expression profiles of MMP-9 and EMMPRIN in chronic rhinosinusitis with nasal polyps

Objective. Metalloproteinases (MMPs) are implicated in tissue remodeling in chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to evaluate the expression profiles of MMP-9 and the extracellular matrix metalloproteinase inducer (EMMPRIN) in nasal polyps compared to healthy mucosa. Methods. Tissue samples from 37 CRSwNP patients undergoing functional endoscopic sinus surgery and mucosal specimens from 12 healthy controls were obtained intra-operatively. MMP-9 and EMMPRIN mRNA levels were assessed by reverse transcriptionpolymerase chain reaction and their protein expression by Western blot analysis. Results. MMP-9 mRNA expression levels were significantly elevated in CRSwNP compared to controls (p < 0.05). MMP-9 protein levels presented an increasing trend but with no statistical significance (p > 0.05). No statistically significant difference in EMMPRIN mRNA and protein levels was identified. Conclusions. Upregulation of MMP-9 in nasal polyps is evident and highlights its role in the pathogenesis of CRSwNP. The lack of concordance between MMP-9 mRNA and protein levels may be attributed to post-translational gene expression regulation. Although EMMPRIN expression was not significantly different between the two groups, its role remains to be elucidated. MMP-9 may be a valuable biomarker and treatment target in CRSwNP.