Tight junction proteins in intestinal cells

Tight junction proteins in intestinal cells are multi-component complexes at the apical-lateral border which seal the paracellular space between neighboring epithelial cells. The major integral membrane proteins involved are Occludin, the Claudin family, Junctional adhesion molecules (JAMs), and Tricellulin, with Zonula occludens (ZO) proteins acting as cytoskeletal adaptors. These proteins are essential for maintaining the intestinal barrier, regulating the paracellular passage of ions, water, solutes, and excluding pathogens and antigens. Disruption leads to barrier dysfunction, observed in inflammatory, infectious, and metabolic diseases. Tight junction proteins are dynamically regulated by intracellular signaling pathways and undergo post-translational modifications (especially phosphorylation), which alter their interactions with the cytoskeleton, their localization, and barrier function. Pharmaceutical strategies aim to stabilize or restore their function in disease states.

Other names

TJ proteinsIntestinal tight junction proteinsCell junction proteinsParacellular barrier proteins

Stabilization of TJ proteins to reduce pathological permeability. Inhibition of kinase-mediated phosphorylation disrupting TJ assembly (e.g., MLCK inhibitors block MLC phosphorylation, preserve barrier function). Modulation of inflammatory cytokine signaling (inhibition of TNF-α, IFN-γ reduces TJ protein internalization and redistribution). Enhancement of protein expression (e.g., promotion of Occludin/Claudins increases TJ integrity).