Present address: Brigham and Women's Hospital, Center for Experimental Therapeutics, Harvard Medical School, Boston, 02115 MA, USA.
Spinal cord injury-induced lesional expression of the repulsive guidance molecule (RGM)
Article first published online: 12 APR 2005
European Journal of Neuroscience
Volume 21, Issue 6, pages 1569–1576, March 2005
How to Cite
Schwab, J. M., Conrad, S., Monnier, P. P., Julien, S., Mueller, B. K. and Schluesener, H. J. (2005), Spinal cord injury-induced lesional expression of the repulsive guidance molecule (RGM). European Journal of Neuroscience, 21: 1569–1576. doi: 10.1111/j.1460-9568.2005.03962.x
- Issue published online: 12 APR 2005
- Article first published online: 12 APR 2005
- Received 19 January 2004, revised 23 November 2004, accepted 6 December 2004
- axon growth inhibition;
- spinal cord
The repulsive guidance molecule (RGM) is involved in the formation of the central nervous system (CNS) during development by modulating guidance of growing axons. However, a role of RGM in CNS injury remains to be established. We studied the expression of RGM in the spinal cord of rats with spinal cord injury (SCI). After SCI, RGM+ cells accumulated in lesions and peri-lesional areas. During the first days after SCI, RGM expression was confined to neurons, ballooned neurite fibers/retraction bulbs, smooth muscle/endothelial cells, and to leucocytes infiltrating the lesion. Lesional RGM expression was frequently confined to hypertrophic β-APP+ and RhoA+ neurites/retraction bulbs. With maturation of the lesion, we observed RGM expression by components of the developing scar tissue (cicatrix), such as fibroblastoid cells, reactive astrocytes and in addition a pronounced extracellular RGM deposition resembling neo-laminae. Frequent RGM+, RhoA+ coexpression by lesional retraction bulbs represent first preliminary evidence of RGM to exert growth inhibitory effects by the second messenger system RhoA. To date, RGM is one of the most potent axonal growth inhibitors identified and present in axonal growth impediments (i) oligodendrocytes; (ii) the plexus choroideus and (iii) components of the developing scar.