Tight junction protein (TJP) (TJP)

Tight junction proteins are the fundamental components of the intestinal mucosal barrier, forming a regulated seal between adjacent epithelial cells to control paracellular permeability [StatPearls, 2023]. This complex consists of transmembrane proteins such as claudins, occludin, and junctional adhesion molecules (JAMs), which are linked to the intracellular actin cytoskeleton via scaffolding proteins like zonula occludens-1 (ZO-1) [Nature Reviews Gastroenterology & Hepatology, 2014]. Their primary biological function is to maintain a selective barrier that allows the absorption of nutrients and water while excluding pathogens, toxins, and environmental antigens from the systemic circulation. Dysfunction of these proteins leads to increased intestinal permeability, a condition often associated with inflammatory bowel disease (IBD), celiac disease, and various systemic autoimmune disorders [Frontiers in Immunology, 2021]. Pharmacological targeting of tight junctions involves either the use of stabilizers to restore barrier integrity, such as the zonulin antagonist larazotide acetate, or the use of modulators to facilitate the oral delivery of large therapeutic molecules [Pharmaceutics, 2021]. Given their ubiquitous presence in epithelial tissues, therapeutic strategies must carefully balance local efficacy in the gut with the risk of systemic barrier disruption.

Other names

Zonula occludensOccludinClaudinJunctional adhesion moleculeJAMIntestinal barrier proteinsApical junctional complex

Regulation of paracellular permeability through the modulation of tight junction assembly, disassembly, and protein expression levels [PubMed, 2022].