Inhibition of IKKβ in Enterocytes Exacerbates Sepsis-Induced Intestinal Injury and Worsens Mortality

Objectives: Nuclear factor-B is a critical regulator of cell-survival genes and the host inflammatory response. The purpose of this study was to investigate the role of enterocyte-specific NF-kB in sepsis through selective ablation of IkB kinase. Design: Prospective, randomized controlled study. Setting: Animal laboratories in university medical centers. Subjects and Interventions: Mice lacking functional NF-kB in their intestinal epithelium (Vil-Cre/Ikk(f/)) and wild-type mice were subjected to sham laparotomy or cecal ligation and puncture. Animals were killed at 24 hours or followed 7 days for survival. Measurements and Main Results: Septic wild-type mice had decreased villus length compared with sham mice, whereas villus atrophy was further exacerbated in septic Vil-Cre/Ikk(f/) mice. Sepsis induced an increase in intestinal epithelial apoptosis compared with sham mice, which was further exacerbated in Vil-Cre/Ikk(f/) mice. Sepsis induced intestinal hyperpermeability in wild-type mice compared with sham mice, which was further exacerbated in septic Vil-Cre/Ikk(f/) mice. This was associated with increased intestinal expression of claudin-2 in septic wild-type mice, which was further increased in septic Vil-Cre/Ikk(f/) mice. Both, pro-inflammatory and anti-inflammatory cytokines were increased in serum following cecal ligation and puncture, and interleukin 10 and monocyte chemoattractant protein-1 levels were higher in septic Vil-Cre/Ikk(f/) mice than in septic wild-type mice. All septic mice were bacteremic, but no differences in bacterial load were identified between wild-type and Vil-Cre/Ikk(f/) mice. To determine the functional significance of these results, animals were followed for survival. Septic wild-type mice had lower mortality than septic Vil-Cre/Ikk(f/) mice (47% vs 80%, p < 0.05). Antitumor necrosis factor administration decreased intestinal apoptosis, permeability, and mortality in wild-type septic mice, and a similar improvement in intestinal integrity and survival were seen when antitumor necrosis factor was given to Vil-Cre/Ikk(f/) mice. Conclusions: Enterocyte-specific NF-kB has a beneficial role in sepsis by partially preventing sepsis-induced increases in apoptosis and permeability, which are associated with worsening mortality.