GAP-43 (B-50) and C-Jun are up-regulated in axotomized neurons of Clarke's nucleus after spinal cord injury in the adult rat.
The growth-associated protein GAP-43 (B-50) and the transcription factor C-Jun are involved in regeneration of the injured nervous system. In this study, we investigated the possibility of the induction of GAP-43 and C-Jun in axotomized neurons of Clarke's nucleus (CN) in adult rats, of which a large population undergoes degeneration several weeks after a low thoracic lateral funiculotomy of the spinal cord. In situ hybridization and immunohistochemistry revealed a transient up-regulation of GAP-43 mRNA, C-Jun protein, and its activated, phosphorylated form, peaking around 7 days after injury in preferentially large diameter CN-neurons ipsilateral and caudal to the lesion. Our results document that some populations of axotomized central nervous system neurons, similar to axotomized regenerating neurons of the peripheral nervous system, can up-regulate GAP-43 and C-Jun, even if they are destined to degenerate. This might reflect a transient regenerative capacity, which fails over time.
Schmitt
A B
AB
Department of Neurology, Aachen University Medical School, Germany. Andreas.Schmitt@rwthaachen.de
Breuer
S
S
Voell
M
M
Schwaiger
F W
FW
Spitzer
C
C
Pech
K
K
Brook
G A
GA
Noth
J
J
Kreutzberg
G W
GW
Nacimiento
W
W
D000818:Animals; D019771:Axotomy; D005260:Female; D019922:GAP-43 Protein / Q000096:biosynthesis*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D009474:Neurons / Q000378:metabolism*; D010766:Phosphorylation; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis*; D015347:RNA Probes; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000378:metabolism*; D015854:Up-Regulation
D019922:GAP-43 Protein; D016755:Proto-Oncogene Proteins c-jun; D015347:RNA Probes; D012333:RNA, Messenger