Intestinal mucins and glycocalyx

Intestinal mucus glycoproteins, primarily the secreted mucin MUC2, and epithelial cell surface glycoconjugates (the glycocalyx) constitute a complex physicochemical barrier essential for gastrointestinal health. This barrier provides lubrication to facilitate the passage of luminal contents and serves as a primary defense mechanism against mechanical stress, digestive enzymes, and enteric pathogens (Johansson et al., 2011, Science). The glycocalyx, composed of membrane-bound mucins like MUC1 and MUC17, also plays a significant role in cell signaling and maintaining the integrity of the epithelial surface. In pathological states such as ulcerative colitis, the mucus layer is often thinned or biochemically altered, leading to increased intestinal permeability and chronic inflammation (Boltin et al., 2013, Journal of Clinical Gastroenterology). Conversely, the over-expression or aberrant glycosylation of cell-surface mucins is a hallmark of colorectal and pancreatic cancers, where they contribute to tumor progression and immune evasion. Therapeutic interventions include mucoprotective agents that enhance barrier function and mucoadhesive delivery systems designed to prolong the local effect of drugs within the gut lumen.

Other names

Intestinal mucus glycoproteinsEpithelial cell surface glycoconjugatesMucinsGlycocalyxIntestinal mucus barrierMUC2MUC1MUC4

Drugs targeting this system work by stimulating the synthesis and secretion of mucins (e.g., Rebamipide), physically binding to the mucosal surface to form a protective shield (e.g., Sucralfate), or utilizing mucoadhesive properties to increase the residence time of locally delivered therapeutics (Hansson, 2012, Nature Reviews Gastroenterology & Hepatology).