Abstract
PURPOSE: We have demonstrated that administration of heparin-binding epidermal growth factor-like growth factor (HB-EGF) protects the intestines from injury. The aim of the current study was to evaluate the effect of HB-EGF gene disruption on intestinal restitution, angiogenesis, and long-term survival after intestinal ischemia/reperfusion (I/R) injury. METHODS: HB-EGF (-/-) and wild-type HB-EGF (+/+) littermate mice were subjected to 45 minutes of superior mesenteric artery occlusion followed by reperfusion. Functional recovery of the gut permeability barrier was evaluated with Ussing chamber studies, and microvessel density was evaluated immunohistochemically. Animal survival was evaluated using the Kaplan-Meier method. RESULTS: Histologic damage after ischemia was significantly higher in HB-EGF (-/-) mice compared with HB-EGF (+/+) mice, associated with a significantly higher number of incompetent (nonhealed, nonresurfaced) villi indicative of delayed structural healing by restitution. HB-EGF (-/-) mice had increased intestinal permeability after intestinal I/R. HB-EGF (-/-) mice had significantly lower microvessel density at 3 and 7 days after I/R, indicating that HB-EGF gene deletion resulted in delayed onset of angiogenesis. Two-week mortality rates were significantly higher in HB-EGF (-/-) mice. CONCLUSIONS: Endogenous HB-EGF significantly enhances healing by restitution, prolongs survival, and enhances angiogenesis in mice subjected to intestinal I/R injury. These findings support our hypothesis that HB-EGF administration may improve outcome in patients with intestinal I/R injury, including necrotizing enterocolitis.