Intestinal epithelial cells (IECs) and mucins (IECs and mucins)

Intestinal epithelial cells (IECs) and mucins represent the fundamental components of the gastrointestinal mucosal barrier, serving as the interface between the host and the external environment (Johansson & Hansson, 2016, Nature Reviews Immunology). IECs form a polarized monolayer that facilitates selective nutrient absorption while maintaining tight junctions to prevent the translocation of luminal pathogens and antigens (Okumura & Takeda, 2017, Nature Reviews Immunology). Overlying these cells is a complex mucus layer composed primarily of the gel-forming glycoprotein MUC2, which provides physical lubrication and a scaffold for antimicrobial peptides and secretory IgA (Johansson & Hansson, 2016). In diseases such as ulcerative colitis and Crohn's disease, the integrity of this barrier is compromised, leading to increased intestinal permeability and chronic immune activation (Turner, 2009, Nature Reviews Immunology). Pharmacological interventions target this system through various mechanisms, including the activation of guanylate cyclase-C to promote fluid secretion (e.g., linaclotide) or the use of aminosalicylates to reduce epithelial inflammation (Wald et al., 2012, American Journal of Gastroenterology; Naito et al., 2010, Journal of Clinical Biochemistry and Nutrition). Strengthening the mucin layer and promoting epithelial repair remain key therapeutic goals for maintaining gut homeostasis and preventing systemic infection (Okumura & Takeda, 2017).

Other names

Intestinal mucosal barrierGut epithelium and mucus layerGastrointestinal barrierIntestinal epithelial-mucus interface

Drugs targeting this system work by activating epithelial receptors such as guanylate cyclase-C to promote fluid secretion, modulating ion channels to alter electrolyte transport, reducing inflammatory cytokine production within the epithelium, or stimulating the secretion of protective mucins to restore barrier integrity (Wald et al., 2012; Naito et al., 2010).