Copyright ©The Author(s) 2016.
World J Gastroenterol. Mar 21, 2016; 22(11): 3117-3126
Published online Mar 21, 2016. doi: 10.3748/wjg.v22.i11.3117
Table 1 Tight junctions of interest in inflammatory bowel diseases
TJ proteinFunctionExpression in CDExpression in UCExpressionin pouchitis
Claudin 1Tightens the epithelium[17,23] able to initiate formation of TJ strands[14]Active: ↑[46,65] ↔[50]Active: ↑[65],↓[40]
Inactive: ↔[65]↔[45]
Inactive: ↔[65]
Claudin 2Important pore-forming TJ protein[15,16,23], able to initiate formation of TJ strands[14], decreases barrier function of CLDN1 and CLDN4[13]↑[44,50,65,101]↑↑[44,50,65,101]↑[40]
Claudin 4Tightens the epithelium, decreases paracellular conductance through decrease in sodium permeability[19]↓[44]Active: ↓[44,45]↔[40]
Active inflammation: ↑[65]Active Inflammation: ↑[65]
Claudin 5Tightens the epithelium[20]↓[50]↔[40]
Claudin 8Tightens the epithelium[21]↓[50]
Claudin 12Tightens the epithelium↑[48]
Claudin 18Uncertain function↑[47]
OccludinBinds ZO-1, regulates paracellular permeability, function in cellular adhesion[102]↓[46,50,52]↓[52]↔[40]
ZO-1Mediates protein-protein interactions, link to actin cytoskeleton: “anchoring” protein[4,103]↓[68]↔[64] (Mees et al: “in patients with a history of UC”)↓[54] (chronic pouchitis)