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Spinal cord injury‐induced lesional expression of the repulsive guidance molecule (RGM)
Author(s) -
Schwab Jan M.,
Conrad Sabine,
Monnier Philippe P.,
Julien Sylvie,
Mueller Bernhard K.,
Schluesener Hermann J.
Publication year - 2005
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2005.03962.x
Subject(s) - neurite , central nervous system , spinal cord , rhoa , spinal cord injury , microbiology and biotechnology , lesion , glial scar , pathology , extracellular , biology , neuroscience , anatomy , medicine , signal transduction , in vitro , biochemistry
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.