Cyclosporin A limits calcium-induced axonal damage following traumatic brain injury

Neuroreport. 1999 Feb 5;10(2):353-8. doi: 10.1097/00001756-199902050-00026.

Abstract

In traumatic axonal injury, Ca2+ influx across a focally damaged axolemma precipitates local mitochondrial failure, degradation of the subaxolemmal spectrin network and compaction of neurofilaments, which collectively contribute to axonal failure. In previous studies, cyclosporin A pretreatment preserved mitochondrial integrity and attenuated axonal failure following trauma. Here we investigate whether this CsA-linked protection was related to the concomitant blunting of intra-axonal, Ca2+-induced cytoskeletal changes in traumatic axonal injury, assessed with antibodies targeting spectrin proteolysis and neurofilament compaction. CsA pretreatment dramatically reduced Ca2+-induced cytoskeletal damage following injury; CsA-treated rats, compared with vehicle-treated rats, displayed a 70% decrease in immunoreactive/damaged profiles. We suggest that CsA-mediated preservation of mitochondrial integrity enables the restoration of ionic and metabolic homeostasis thereby short-circuiting Ca2+-induced proteolysis in injured axons.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Axons / drug effects*
  • Axons / pathology
  • Biomarkers
  • Brain / pathology
  • Brain Injuries / pathology*
  • Calcium / physiology*
  • Calpain / physiology
  • Cyclosporine / pharmacology*
  • Image Processing, Computer-Assisted
  • Immunohistochemistry
  • Male
  • Peptide Hydrolases / metabolism
  • Pyramidal Tracts / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Spectrin / metabolism

Substances

  • Biomarkers
  • Spectrin
  • Cyclosporine
  • Peptide Hydrolases
  • Calpain
  • Calcium