Expression and Role of Calcitonin Gene-Related Peptide in Patients With Chronic Rhinosinusitis With Nasal Polyposis

Abstract

Background and Objectives A recent study revealed that calcitonin gene-related protein (CGRP) plays an important role in inflammatory airway diseases. However, the influence of CGRP on chronic rhinosinusitis (CRS) has not been studied. This study investigated the expression, activity, and potential pathogenic role of CGRP in patients with CRS with nasal polyposis (CRSwNP).Subjects and Method Patients with CRSwNP and control subjects were enrolled. The CRSwNP group was divided according to the presence of eosinophilic polyps and non-eosinophilic polyps. Nasal polyps (NPs) and uncinate tissues (UTs) from patients with CRSwNP and UTs from control subjects were obtained to investigate the expression of α-/β-CGRP and chromogranin A. In addition, the expression patterns of cytokines following exposure to exogenous CGRP were analyzed in dispersed nasal polyp cells (DNPCs) from patients with eosinophilic or non-eosinophilic CRSwNP. The effects of CGRP on lipopolysaccharide (LPS)-induced nuclear factor-kappa light chain enhancer of activated B cells (NF-κB) signaling change were evaluated in THP-1 cells.Results The expression of α-/β-CGRP and number of CGRP-producing cells were significantly higher in NPs from patients with CRSwNP than in UTs from controls. Exogenous CGRP decreased the expression of inflammatory cytokines and increased that of the anti-inflammatory cytokines in DNPCs from patients with eosinophilic nasal polyps (EPs) and also increased the expression of tissue remodeling-related and anti-inflammatory cytokines in DNPCs from patients with non-eosinophilic nasal polyps (N-EPs). CGRP inhibited the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB) phosphorylation and NF-κB translocation in LPS-stimulated M1 macrophages.Conclusion CGRP expression in NPs may play a significant role in nasal polypogenesis through inflammatory modulation, and it could be a future target to modulate certain aspects of CRSwNP.