Study Suggests Intestinal Barrier Dysfunction in Crohn's
Changes in claudin 2, 5 and 8 protein expression may lead to intestinal barrier dysfunction
WEDNESDAY, Jan. 24 (HealthDay News) -- Patients with mild to moderately active Crohn's disease have increased epithelial apoptosis and expression of the pore-forming claudin-2 protein in the colon, as well as downregulation of sealing claudins 5 and 8, which results in intestinal barrier dysfunction, according to the results of a study published in the January issue of Gut.
Joerg-Dieter Schulzke, M.D., of Charite, Campus Benjamin Franklin in Berlin, Germany, and colleagues assessed sigmoid colon biopsy specimens from patients with mild to moderately active Crohn's disease and compared them to specimens from inactive Crohn's disease.
Freeze fracture electron microscopy revealed reduced and discontinuous tight junction structure compared to controls. Occludin and sealing tight junction proteins claudin 5 and claudin 8 were downregulated and claudin 2 was upregulated in active disease. Increased epithelial apoptosis was seen in active Crohn's disease (5.2 percent) compared to controls (1.9 percent).
The researchers "provide strong evidence that the tight junction barrier function is altered in inflammatory bowel disease, and also suggest some specific mechanisms that may underlie these changes," the authors of an editorial conclude.