Basic Research
Copyright ©The Author(s) 2005. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 14, 2005; 11(26): 4024-4031
Published online Jul 14, 2005. doi: 10.3748/wjg.v11.i26.4024
Ephrin-B2 is differentially expressed in the intestinal epithelium in Crohn’s disease and contributes to accelerated epithelial wound healing in vitro
Christian Hafner, Stefanie Meyer, Thomas Langmann, Gerd Schmitz, Frauke Bataille, Ilja Hagen, Bernd Becker, Alexander Roesch, Gerhard Rogler, Michael Landthaler, Thomas Vogt
Christian Hafner, Stefanie Meyer, Ilja Hagen, Bernd Becker, Alexander Roesch, Michael Landthaler, Thomas Vogt, Department of Dermatology, University Hospital of Regensburg, D-93042 Regensburg, Germany
Thomas Langmann, Gerd Schmitz, Department of Clinical Chemistry, University Hospital of Regensburg, D-93042 Regensburg, Germany
Frauke Bataille, Institute of Pathology, University Hospital of Regensburg, D-93042 Regensburg, Germany
Gerhard Rogler, Department of Internal Medicine, University Hospital of Regensburg, D-93042 Regensburg, Germany Supported by the German Research Society (DFG-SFB 585/A8) and the Dr. Heinz Maurer Grant KFB 1.7
Author contributions: All authors contributed equally to the work.
Correspondence to: Professor Dr. Thomas Vogt, Department of Dermatology, University of Regensburg, D-93042 Regensburg, Germany. thomas.vogt@klinik.uniregensburg.de
Telephone: +49-941-944-9606 Fax: +49-941-944-9608
Received: August 26, 2004
Revised: October 3, 2004
Accepted: October 7, 2004
Published online: July 14, 2005
Abstract

AIM: Eph receptor tyrosine kinases and their membrane bound receptor-like ligands, the ephrins, represent a bi-directional cell-cell contact signaling system that directs epithelial movements in development. The meaning of this system in the adult human gut is unknown. We investigated the Eph/ephrin mRNA expression in the intestinal epithelium of healthy controls and patients with inflammatory bowel disease (IBD).

METHODS: mRNA expression profiles of all Eph/ephrin family members in normal small intestine and colon were established by real-time RT-PCR. In addition, differential expression in IBD was investigated by cDNA array technology, and validated by both real-time RT-PCR and immunohistochemistry. Potential effects of enhanced EphB/ephrin-B signaling were analyzed in an in vitro IEC-6 cell scratch wound model.

RESULTS: Human adult intestinal mucosa exhibits a complex pattern of Eph receptors and ephrins. Beside the known prominent co-expression of EphA2 and ephrinA1, we found abundantly co-expressed EphB2 and ephrin-B1/2. Interestingly, cDNA array data, validated by real-time PCR and immunohistochemistry, showed upregulation of ephrin-B2 in both perilesional and lesional intestinal epithelial cells of IBD patients, suggesting a role in epithelial homeostasis. Stimulation of ephrin-B signaling in ephrin-B1/2 expressing rat IEC-6-cells with recombinant EphB1-Fc resulted in a significant dose-dependent acceleration of wound closure. Furthermore, fluorescence microscopy showed that EphB1-Fc induced coordinated migration of wound edge cells is associated with enhanced formation of lamellipodial protrusions into the wound, increased actin stress fiber assembly and production of laminin at the wound edge.

CONCLUSION: EphB/ephrin-B signaling might represent a novel protective mechanism that promotes intestinal epithelial wound healing, with potential impact on epithelial restitution in IBD.

Keywords: Ephrin-B2, Crohn’s disease, IBD, IEC-6, Wound healing, Epithelial restitution