Increased expression of MUC5AC and MUC5B promoting bacterial biofilm formation in chronic rhinosinusitis patients

Objective: Binding of bacteria to mucin and then colonizing is the first step of bacterial biofilm (BBF) formation in chronic rhinosinusitis (CRS) patients. Yet, information is sparse on how mucins effects on BBF formation. In this study, we aimed to investigate the relationship between mucin expression and the formation of BBF in CRS patients. Methods: Sinus mucosa were harvested from 24 patients undergoing endoscopic surgery for CRS. The positive of BBF formation were detected by scanning electronic microscopy (SEM) and the expression of MUC1, MUC2, MUC5AC, and MUC5B were determined by immunohistochemistry (IHC). The difference expression of mucins were analyzed between the BBF positive and negative cohorts in CRS patients. Results: MUC5AC and MUC5B are two major mucins in CRS mucosa with the former mainly restricted to the goblet cells of epithelium and the latter mainly restricted to the submucosal glands. Expression of MUC5AC and MUC5B in the sinus mucosa of BBF(+) CRS group was significantly higher than those in BBF(-) CRS group (p < 0.05). For MUC1 and MUC2, no significant difference was found between the two groups (p > 0.05). Conclusion: Our study indicated that increased expression of MUC5AC and MUC5B may play an important role in the pathogenesis of BBF formation. (C) 2015 Elsevier Ireland Ltd. All rights reserved.