Activation of nuclear factor κB in colonic mucosa from patients with collagenous and ulcerative colitis

Abstract

In collagenous and ulcerative colitis, colonic mucosal NFkappaB is activated and recruited to the iNOS promoter in vivo via an IKKbeta mediated pathway. As collagenous colitis is not associated with tissue injury, these data challenge the prevailing view that activation of NFkappaB per se mediates tissue injury. Our results suggest that downstream inflammatory reactions leading to tissue damage originate in lamina propria immune cells, as increased NFkappaB activity in collagenous colitis was localised solely in epithelial cells, but present also in macrophages in ulcerative colitis.