Epithelial barrier integrity pathway

Epithelial barrier integrity pathways encompass the structural and regulatory mechanisms that maintain the selective permeability of epithelial layers across various organs, including the gut, lungs, and skin. These pathways are centered around the apical junctional complex, which consists of tight junctions, adherens junctions, and desmosomes that physically tether adjacent cells and seal the paracellular space (PubMed: 28407195). Key proteins involved include claudins, occludin, and zonula occludens-1 (ZO-1), which are regulated by signaling molecules such as myosin light chain kinase (MLCK) and various Rho GTPases (PubMed: 30126404). In disease states like inflammatory bowel disease (IBD) or asthma, these pathways are often compromised, leading to increased permeability or 'leakiness' that allows pathogens and allergens to penetrate deeper tissues and trigger chronic inflammation (PubMed: 31247338). Pharmacological intervention focuses on stabilizing these junctions or preventing their breakdown, with agents like larazotide acetate acting as zonulin antagonists to reduce paracellular leakage (PubMed: 24639186). Understanding these pathways is crucial for developing therapies that restore tissue homeostasis and prevent the systemic consequences of barrier dysfunction.

Other names

Intestinal barrier functionMucosal barrier integrityTight junction complexParacellular barrierApical junctional complex

Stabilization of tight junction proteins, inhibition of zonulin-induced cytoskeletal rearrangement, and reduction of cytokine-mediated junctional internalisation.