Abstract
Abstract Introduction: Necrotizing enterocolitis (NEC) is characterized by inadequate mucosal healing due to impaired enterocyte migration along the crypt villus axis (Surgical Forum 2003). Because adjacent enterocytes migrate together, inter-enterocyte communication may be required for mucosal healing. Many cells communicate via gap junctions (GJ) comprised of the protein connexin-43. We therefore hypothesize that enterocyte migration requires inter-enterocyte communication, and that impaired healing during NEC is associated with impaired connexin-43 expression. Methods: Connexin-43 expression was assessed by SDS-PAGE and immunofluorescence in IEC-6 enterocytes. GJ function was determined by the selective inter-enterocyte passage of lucifer yellow microinjected into IEC-6 cells with impermeant rhodamine-dextran ±GJ inhibitor oleamide (25μM).Migration was measured by time-lapse microscopy of IEC-6 cells moving into a scraped wound ±oleamide. NEC was induced in newborn rats by formula gavage + hypoxia and terminal ileal mucosal scrapings were harvested for SDS-PAGE. Results: The GJ protein connexin-43 was expressed between adjacent IEC-6 cells and in mucosal scrapings. Lucifer yellow but not Rd-dextran passed between adjoining cells, indicating functional gap junctions. Oleamide significantly impaired GJs in enterocytes (communicating cells: control 3 ± 1 vs. 0.5 ± .2, p Conclusions: Enterocyte migration requires intercellular communication via gap junctions, which are reduced in NEC. These findings provide insights into the mechanisms leading to impaired mucosal healing in this disease.