Table 2.

Barrier defects associated with inflammatory diseases of the intestine [41]

Disease	Cause of barrier defect	Timing of barrier defect	Effects on Tight Junction proteins and cytoskeleton	Citations
Crohn’s disease	Unknown; Association with frameshift insertion at nucleotide 3020 of NOD2	Before clinical onset or clinical relapse	Claudin-2 upregulation; MLCK activation;	[61, 119, 120]
Ulcerative colitis	Unknown	Unknown	Occludin downregulation	[61, 119, 120]
C. difficile colitis	Actomyosin disruption; glycosylation of Rho proteins	Toxin release; disease onset	Loss of ZO-1 and ZO-2	[121]
GVHD	Associated t TNF production	After clinical onset	Unknown	[122]

Modified from Turner JR. Intestinal mucosal barrier function in health and disease. Nat Rev Immunol. 2009;9(11):799–809.

GVHD graft-versus host disease, MLCK myosin light chain kinase, ZO zonula occludens