Rapid calpain I activation and cytoskeletal protein degradation following traumatic spinal cord injury: attenuation with riluzole pretreatment.

TitleRapid calpain I activation and cytoskeletal protein degradation following traumatic spinal cord injury: attenuation with riluzole pretreatment.
Publication TypeJournal Article
Year of Publication1997
JournalJournal of neurochemistry
Volume69
Issue4
Pagination1592-600
ISSN0022-3042
Abstract

Immunocytochemical and immunoblotting techniques were used to investigate calpain I activation and the stability of the calpain-sensitive cytoskeletal proteins microtubule-associated protein 2 (MAP2) and spectrin at 1, 4, and 24 h after contusion injury to the spinal cord. Spinal cord injury resulted in the activation of calpain I at all time points examined, with the highest level of activation occurring at 1 h. At the same early time point, there was a loss of dendritic MAP2 staining in spinal cord sections, accompanied by pronounced perikaryal accumulation. The loss in MAP2 staining in the injured spinal cord progressed over the 24-h survival period to affect regions 3 mm distant to the site of injury. The presence of calpain I-specific spectrin degradation was apparent in neuronal cell bodies and fibers as early as 1 h after injury, with the most intense staining occurring within and juxtaposed to the injury site. Spectrin breakdown products in neuronal cell bodies declined rapidly at 4 h and were nearly undetectable at 24 h after injury. Immunoblot studies confirmed the immunocytochemical results by demonstrating a significant increase in calpain I activation, a significant decrease in MAP2 levels, and a significant increase in spectrin breakdown. Finally, treatment of animals with riluzole, an inhibitor of glutamate release, before surgery reduced significantly the loss of MAP2 levels observed at 24 h after injury. These results demonstrate that Ca2+-dependent protease activation and degradation of critical cytoskeletal proteins are early events after spinal cord injury and that treatments that minimize the actions of glutamate may limit their breakdown.

URLhttps://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0022-3042&date=1997&volume=69&issue=4&spage=1592
Short TitleJ Neurochem
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