Recombinant human trefoil factor 3 ameliorates bowel injury: its anti-inflammatory effect on experimental necrotizing enterocolitis

Abstract

Aim. Recombinant human trefoil factor 3 (intestinal trefoil factor) has been suggested to be partially protective against necrotizing enterocolitis (NEC), but the mechanisms of this protection have not been defined. We investigated whether the protective effects of rhTFF3 are the result of an anti-inflammatory response. Methods. The rats were killed on day 4, the distal ileum was harvested for morphological studies and immunohistochemistry for NF- κ B (p65), and the amounts of IL-1 β , IL-6, and IL-10 in the intestinal tissue were measured using commercial ELISA assay kits. Results. In the neonatal NEC, IL-1 β , IL-6, and IL-10 were significantly higher than in normal group. In normal group, IL-1 β and IL-6 were significantly decreased, and the amount of IL-10 was markedly increased compared with NEC group. In the NEC model, immunohistochemical staining for NF- κ B (p65) was demonstrated to be of a strong brown color and was distributed in the intestinal epithelium. Treatment with rhTFF3 significantly decreased the immunoreactivity of NF- κ B (p65) in the NEC model. Conclusions. Intestinal inflammation was ameliorated after rhTFF3 was injected. rhTFF3 may protect against the intestinal injury of the neonatal rat NEC model by suppression of the inflammatory response.

Figure 1

Small intestinal histology in the neonatal rats treated as described in Section 2 (HE staining). (a) Control animal showing the normal intestinal villus architecture (score 0). (b) NEC animal treated with rhTFF3 by subcutaneous injection showing a slight histological injury (score 2): moderate separation of submucosa (arrow). (c) NEC animal with complete villous necrosis (score 4): severe separation of submucosa and loss of villi with necrosis (arrow). (HE, magnification ×200.)

Figure 2

The effect of rhTFF3 on the small intestinal amounts of IL-1β, IL-6, and IL-10. (A) Control animal. (B) Control animal treated with rhTFF3. (C) NEC animal. (D) NEC animal treated with 0.9% sodium chloride. (E) NEC animal treated with rhTFF3. *P < 0.05, **P < 0.01 versus the E group.

Figure 3

Immunohistochemistry analysis using a polyclonal antibody for NF-κB (Santa Cruz Biotech) in a small intestinal sample from (a) control animal: NF-κB is barely detectable in the epithelium. (b) NEC animal: NF-κB staining is pronounced in the nuclei of inflammatory cells (arrow). (c) NEC animal treated with rhTFF3 by subcutaneous injection for 3 days: NF-κB staining is reduced in the epithelium. All the animals were decapitated and sampled at day 4. (SP, magnification ×400.)