Intestinal epithelial mucin (MUC) (MUC)

Intestinal epithelial mucins are high-molecular-weight glycoproteins that serve as the primary structural components of the protective mucus barrier in the gastrointestinal tract (PMID: 23435115). They are divided into two main categories: secreted gel-forming mucins, predominantly Mucin 2 (MUC2), and membrane-bound mucins such as MUC1, MUC3, and MUC13 (UniProt Q02817, PMID: 21666637). These proteins provide a physical and chemical shield against mechanical stress, digestive enzymes, and enteric pathogens while facilitating the transport of nutrients and lubrication of the luminal surface (PMID: 22553002). In pathological states like inflammatory bowel disease (IBD), a reduction in mucin production or altered glycosylation leads to a compromised barrier, allowing bacteria to penetrate the epithelium and trigger inflammation (PMID: 24854413). Conversely, in colorectal cancer, mucins are often overexpressed or aberrantly glycosylated, contributing to tumor cell survival and immune evasion (PMID: 25231408). Therapeutic interventions targeting these mucins include mucolytic agents like N-acetylcysteine to clear obstructive mucus and secretagogues like rebamipide to enhance the protective layer (PMID: 12113585). Additionally, mucins are being explored as biomarkers for disease progression and as targets for mucoadhesive drug delivery systems (PMID: 28107462). The complex O-glycosylation of these proteins is critical for their function and is a major area of research for developing targeted therapies (PMID: 26915565).

Other names

MucinMucin 2MUC2Mucin 3MUC3Mucin 12MUC12Mucin 13MUC13Mucin 17MUC17Gastrointestinal mucin

Mucolytic activity through the reduction of disulfide bonds to decrease mucus viscosity, mucin secretagogue action to stimulate endogenous production, and barrier enhancement via the formation of protective physical complexes on the epithelial surface.