Intestinal mucin and surface glycans (MUC)

Intestinal mucus glycoproteins, predominantly Mucin-2 (MUC2), and their associated surface carbohydrates (glycans) constitute the primary physicochemical barrier of the gastrointestinal tract (Hansson, 2012, Nature Reviews Gastroenterology & Hepatology). These large, heavily O-glycosylated proteins form a viscoelastic gel that protects the intestinal epithelium from mechanical damage, digestive enzymes, and pathogenic invasion while facilitating the transport of nutrients (Johansson et al., 2011, Proceedings of the National Academy of Sciences). The carbohydrate moieties, or glycans, serve as a critical energy source and attachment site for the gut microbiota, maintaining a symbiotic relationship between the host and commensal bacteria (Juge, 2012, Trends in Microbiology). In pathological states such as ulcerative colitis or Crohn's disease, the mucus layer is often depleted or biochemically altered, leading to increased epithelial permeability and chronic inflammation (Boltin et al., 2013, Journal of Clinical Gastroenterology). Pharmacologically, this system is targeted through mucoadhesive drug delivery systems that utilize polymers like chitosan to prolong drug contact time with the mucosa (Khutoryanskiy, 2011, Macromolecular Bioscience). Additionally, cytoprotective agents like rebamipide and sucralfate work by enhancing mucus secretion or binding to the glycoprotein matrix to shield underlying ulcers from acid and pepsin (Ishijima et al., 2010, Journal of Gastroenterology).

Other names

Intestinal mucus glycoproteinsGastrointestinal glycocalyxMUC2Mucin-2Surface carbohydratesO-glycansIntestinal mucus barrier

Mucoadhesion to glycoprotein matrix, mucolysis of disulfide bonds, stimulation of mucus secretion, competitive inhibition of microbial adhesion, and physical shielding of the epithelium.