Intestinal epithelial tight and adherens junction proteins (AJC)

The intestinal epithelial tight and adherens junction proteins constitute the apical junctional complex (AJC), which serves as the primary physical barrier between the intestinal lumen and the underlying mucosal immune system. Tight junctions, including claudins, occludin, and zonula occludens proteins, regulate paracellular permeability and maintain cell polarity, while adherens junctions, featuring E-cadherin and catenins, provide the adhesive strength necessary for tissue integrity (PMID: 23303615, 28461160). Disruption of these junctional complexes is a central feature in the pathogenesis of inflammatory bowel disease (IBD), celiac disease, and irritable bowel syndrome, where 'leaky gut' allows for the translocation of luminal antigens that trigger chronic inflammation (PMID: 22314561). Pharmacological modulation of these proteins, such as through zonulin antagonists like larazotide acetate or growth factors like glucagon-like peptide-2 (GLP-2) analogs, aims to seal the barrier and reduce systemic inflammatory triggers. Consequently, these proteins are high-priority targets for drug development in gastroenterology and autoimmune research.

Other names

Apical junctional complexIntestinal barrier proteinsTight junction proteinsAdherens junction proteinsParacellular junctional complex

Modulation of paracellular permeability through the regulation of tight junction assembly, antagonism of zonulin-mediated disassembly, and enhancement of junctional protein expression and localization.