Host intestinal epithelial cell-surface glycoproteins and mucins

Host intestinal epithelial cell-surface glycoproteins and mucins represent a diverse class of glycoconjugates that form the essential protective interface between the mammalian host and the external environment of the gut lumen (McGuckin et al., 2011). This system includes large, gel-forming secreted mucins, primarily MUC2, and a dense glycocalyx composed of membrane-tethered mucins such as MUC1, MUC4, and MUC17 (Corfield, 2015). These molecules function as a physical and chemical barrier, preventing the direct contact of digestive enzymes and toxins with the epithelial monolayer while also serving as a scaffold for antimicrobial peptides and immunoglobulin A (Johansson et al., 2011). Beyond their structural role, the specific glycan motifs on these proteins act as receptors for microbial adhesins, determining the composition of the commensal microbiota and the susceptibility to enteric pathogens (Juge, 2012). Dysregulation of mucin expression or altered glycosylation is a hallmark of inflammatory bowel diseases and is implicated in the progression of colorectal malignancies (Boltin et al., 2013). Pharmacological intervention typically involves the use of mucosal protectants like rebamipide, which enhances mucin secretion, or mucolytic agents like N-acetylcysteine, which modulate mucus viscosity for therapeutic purposes (Naito et al., 2010).

Other names

Intestinal mucus barrierGastrointestinal glycocalyxCell-surface glycoconjugatesEnterocyte surface mucinsIntestinal mucosal barrierMucin-glycan barrier

Stimulation of mucin synthesis and secretion, physical binding to surface glycoproteins to create a protective barrier, or chemical reduction of disulfide bonds to alter mucus rheology.