Mild postischemic hypothermia prolongs the time window for gene therapy by inhibiting cytochrome C release.
OBJECTIVE
We showed previously that Bcl-2 overexpression with the use of herpes simplex viral (HSV) vectors improved striatal neuron survival when delivered 1.5 hours after stroke but not when delivered 5 hours after stroke onset. Here we determine whether hypothermia prolongs the therapeutic window for gene therapy.


METHODS
Rats were subjected to focal ischemia for 1 hour. Hypothermia (33 degrees C) was induced 2 hours after insult and maintained for 3 hours. Five hours after ischemia onset, HSV vectors expressing Bcl-2 plus beta-gal or beta-gal alone were injected into each striatum. Rats were killed 2 days later.


RESULTS
Striatal neuron survival of Bcl-2-treated, hypothermic animals was improved 2- to 3-fold over control-treated, hypothermic animals and Bcl-2-treated, normothermic animals. Neuron survival among normothermic, Bcl-2-treated animals was not different from control normothermics or control hypothermics. Double immunostaining of cytochrome c and beta-gal demonstrated that Bcl-2 plus hypothermia significantly reduced cytochrome c release.


CONCLUSIONS
Postischemic mild hypothermia extended the time window for gene therapy neuroprotection using Bcl-2 and reduced cytochrome c release.
Zhao
Heng
H
Department of Neurosurgery, Stanford University, Stanford, CA 94305-5327, USA.
Yenari
Midori A
MA
Sapolsky
Robert M
RM
Steinberg
Gary K
GK
D000818:Animals; D002545:Brain Ischemia / Q000150:complications / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D002470:Cell Survival / Q000187:drug effects; D003342:Corpus Striatum / Q000473:pathology; D045304:Cytochromes c / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004195:Disease Models, Animal; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D007036:Hypothermia, Induced / Q000379:methods*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018139:Simplexvirus / Q000235:genetics; D020521:Stroke / Q000150:complications / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D019253:Proto-Oncogene Proteins c-bcl-2; D045304:Cytochromes c; D001616:beta-Galactosidase