Bcl-2 overexpression protects against neuron loss within the ischemic margin following experimental stroke and inhibits cytochrome c translocation and caspase-3 activity

J Neurochem. 2003 May;85(4):1026-36. doi: 10.1046/j.1471-4159.2003.01756.x.

Abstract

Bcl-2 protects against both apoptotic and necrotic death induced by several cerebral insults. We and others have previously demonstrated that defective herpes simplex virus vectors expressing Bcl-2 protect against various insults in vitro and in vivo, including cerebral ischemia. Because the infarct margin may be a region that is most amenable to treatment, we first determined whether gene transfer to the infarct margin is possible using a focal ischemia model. Since ischemic injury with and without reperfusion may occur by different mechanisms, we also determined whether Bcl-2 protects against focal cerebral ischemic injury either with or without reperfusion in rats. Bax expression, cytochrome c translocation and activated caspase-3 expression were also assessed. Viral vectors overexpressing Bcl-2 were delivered to the infarct margin. Reperfusion resulted in larger infarcts than permanent occlusion. Bcl-2 overexpression significantly improved neuron survival in both ischemia models. Bcl-2 overexpression did not alter overall Bax expression, but inhibited cytosolic accumulation of cytochrome c and caspase-3 activation. Thus, we provide the first evidence that gene transfer to the infarct margin is feasible, that overexpression of Bcl-2 protects against damage to the infarct margin induced by ischemia with and without reperfusion, and that Bcl-2 overexpression using gene therapy attenuates apoptosis-related proteins. This suggests a potential therapeutic strategy for stroke.

Publication types

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

MeSH terms

  • Animals
  • Brain Ischemia / etiology
  • Brain Ischemia / pathology
  • Brain Ischemia / therapy*
  • Caspase 3
  • Caspase Inhibitors
  • Caspases / metabolism*
  • Cell Count
  • Cytochrome c Group / metabolism*
  • Disease Models, Animal
  • Drug Administration Routes
  • Fluorescent Antibody Technique
  • Genetic Therapy / methods
  • Genetic Vectors / administration & dosage
  • Genetic Vectors / genetics
  • Infarction, Middle Cerebral Artery / complications
  • Infarction, Middle Cerebral Artery / therapy
  • Neurons / drug effects
  • Neurons / metabolism*
  • Neurons / pathology
  • Protein Transport / drug effects
  • Protein Transport / physiology
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis*
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / pharmacology
  • Rats
  • Reperfusion
  • Stroke / etiology
  • Stroke / pathology
  • Stroke / therapy*
  • bcl-2-Associated X Protein

Substances

  • Bax protein, rat
  • Caspase Inhibitors
  • Cytochrome c Group
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • bcl-2-Associated X Protein
  • Casp3 protein, rat
  • Caspase 3
  • Caspases