Analysis of eosinophil granule proteins in ECRS

Eosinophilic chronic rhinosinusitis (ECRS) is a subtype of chronic rhinosinusitis (CRS) that is characterized by eosinophilic nasal polyposis. Because several types of cells play a role in pathogenesis, ECRS is a heterogenous disease. To identify each cell function is important for the individualization of therapy. The eosinophil is a granulocyte that contain eosinophil granule proteins (EGPs). EGPs have antiparasitic activity, on the other hand, closely related allergic inflammation due to its cytotoxicity. Eosinophil-derived neurotoxin (EDN) is one of the eosinophil granule proteins. In this study, we evaluated the function of EDN in ECRS pathogenesis. Serum EDN levels were significantly higher in patients with ECRS than in those with other nasal and paranasal diseases and were positively correlated with clinical disease activity. EDN expressed in the eosinophils of ECRS nasal polyps. Human nasal epithelial cells (HNEpCs) were stimulated with EDN, and the resultant changes in gene expression were detected by RNA sequencing. Pathway analysis revealed that the major canonical pathway affected by EDN stimulation was “regulation of the epithelial–mesenchymal transition (EMT) pathway”; the only gene in this pathway to be up-regulated was matrix metalloproteinase 9 (MMP-9). EDN may be involved in the pathogenesis of ECRS and also be an important therapeutic target.