Time course of colonic nuclear factor-kappa B expression during bacterial peptidoglycan-polysaccharide-induced...

Nuclear factor-kappa B has been proposed to play a role in the pathogenesis of bacterial peptidoglycan-polysaccharide-induced colitis. However, its colonic expression has not been defined in detail. The primary aim of this study was to profile this expression in the rat colon. Peptigoglycan-polysaccharide was administered to the rat colon by direct intramural injections. Gross colonic injury was determined at various time points. Concomitantly, colonic nuclear factor-kappa B was measured by an electrophoretic mobility shift assay and by immunohistochemistry. Gross colonic injury and colonic nuclear factor-kappa B expression showed similar time courses following peptigoglycan-polysaccharide administration. Peak colonic injury and nuclear factor-kappa B expression were found on day 21. Nuclear factor-kappa B was mainly expressed in submucosal inflammatory cells. In conclusion, the administration of bacterial peptidoglycan-polysaccharide to the rat colon caused a chronic colitis, which was characterized by up-regulated colonic nuclear factor-kappa B.