Role of non cholinergic system components in Chronic Rhinosinusitis and Nasal Polyps

The Choline acetyltransferase (ChAT) enzyme and its product Acetylcholine (ACh) are classically components of the cholinergic system, however recent data clearly demonstrated their potential role in the bronchial airway inflammation. The aim of this study was to identify whether ChAT, Muscarinic receptor M3 and ACh are involved in the nasal airway inflammation of subjects with Chronic Rhinosinusitis (CR) and Nasal polyps (common in many patients with CR). We collected nasal specimens from normal subjects, from allergic patients with CR (ACR) and from ACR and nasal polyps. Fragments from surgical biopsies were extracted for both total mRNA and total proteins to analyse the levels of ChAT and M3 receptor. Protein extracts were also used for the analysis of ACh by a fluorimetric method. ChAT, M3 and ACh immunohistochemistry was performed in nasal sections of surgical biopsies fixed in formalin and embedded in paraffin. We identified increased levels of both ChAT and M3 mRNA and proteins. Also ChAT and M3 expression was increased in airway epithelial cells from ACR and ACR with nasal polyps when compared with normal subjects. Additionally increased levels of ACh were observed in the protein extracts as well as in airway epithelial cells from biopsies of ACR and ACR with nasal polyps when compared with normal subjects. The results of this study provide evidences of a potential role of the component of cholinergic systems in the airway inflammation of ACR and nasal polyps that involved the nasal epithelial cells.