Neuroscience 2001 Abstract
| Presentation Number: | 368.7 |
|---|---|
| Abstract Title: | EPH RECEPTORS AND EPHRINS PARTICIPATE IN SPINAL CORD REORGANIZATION AFTER INJURY. |
| Authors: |
Bundesen, L. Q.*1
; Scheel, T. A.1
; Bregman, B. S.1
; Kromer, L. F.1
1Dept Neurosci, Georgetown Univ, Washington, DC |
| Primary Theme and Topics |
Development - Transplantation and Regeneration -- Regeneration |
| Secondary Theme and Topics | Development<br />- Axonal and Dendritic Development<br />-- Axon guidance: receptors and signaling mechanisms |
| Session: |
368. Transplantation and regeneration: regeneration VI Poster |
| Presentation Time: | Monday, November 12, 2001 3:00 PM-4:00 PM |
| Location: | Exhibit Hall C-63 |
| Keywords: | Regeneration, glial scar, astrocyte, fibroblast |
One cause of regenerative failure observed after spinal cord injury is the expression of repulsive factors at the injury site. Eph receptors and their ligands, the ephrins, are candidates that could mediate inhibitory effects on axonal regeneration, since these molecules mediate contact-dependent inhibitory signals that regulate axonal pathfinding and tissue patterning during development. However, little is known about the function of the ephrin/Eph system after CNS injury in the adult. Previously, we reported that after thoracic spinal cord transection in adult rats, EphB2 protein levels increased at the lesion 1-2 weeks after injury (Bundesen et al., SFN Abstr. 2000). Immunohistochemistry revealed that EphB2 was expressed by fibroblasts infiltrating the lesion site. In the present study, we observed that ephrinB2, a ligand for EphB2, was strongly expressed by astrocytes at the glial scar. No intermingling of EphB2-positive fibroblasts and ephrinB2-positive astrocytes was observed. Thus, we propose that receptor-ligand signaling between EphB2-bearing fibroblasts and ephrinB2-bearing astrocytes: 1) plays a crucial role in establishing the glial scar barrier at the CNS interface, and 2) initiates intracellular signaling cascades which result in the deposition of inhibitory ECM molecules. We have also observed that some supraspinal axons express ephrinB3 in their retraction bulbs, which may mediate a repellent signal at the glial scar. Thus, lesion-induced changes in Eph receptors and ephrins may help to determine the nature of the glial scar, as well as initiate intracellular signals that inhibit axonal regeneration after spinal cord injury.
Supported by NIH grants NS19259, NS38266, and ISRT.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2001 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2001. Online.
Copyright © 2001-2026 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
