Adeno-associated viral-vector-mediated hypoxia-inducible vascular endothelial growth factor gene expression attenuates ischemic brain injury after focal cerebral ischemia in mice.
OBJECTIVE
Exogenous delivery of vascular endothelial growth factor gene (VEGF) may provide a useful approach to the treatment of brain ischemia. We investigated the use of a hypoxia-responsive element to control VEGF expression given for neuroprotection.


METHODS
Three groups (n=36) of mice received AAVH9-VEGF, AAVH9-lacZ, or saline injection. Five days after gene transfer, the mice underwent 45 minutes of transient middle cerebral artery occlusion (tMCAO) followed by 1 to 7 days of reperfusion. Infarct volume was determined using cresyl violet staining; neuronal injury was examined using TUNEL, cleaved caspase-3, and fluoro-Jade B staining.


RESULTS
Hypoxia-inducible factor-1 (HIF-1) was overexpressed after tMCAO in the ischemic hemisphere in the brain. Expression of lacZ, mediated by AAV-lacZ, was seen before and after tMCAO; however, AAVH9-lacZ-mediated lacZ expression was detected only after tMCAO. Infarct volume was smaller in the AAVH9-VEGF-transduced group compared with AAVH9-lacZ and saline groups (55% reduction, P<0.05) with reduced TUNEL (29+/-5% and 30+/-7% versus 12+/-3%, P<0.05), cleaved caspase-3 (20+/-3% and 21+/-5% versus 13+/-4%, P<0.05) and fluoro-Jade B (23+/-3% and 24+/-5% versus 12+/-5%, P<0.05) -positive neurons, respectively.


CONCLUSIONS
Exogenous expression of VEGF through AAVH9-VEGF gene transfer 5 days before the onset of ischemia provides neuroprotection. Hypoxia-responsive element is a viable strategy of restricting VEGF expression to areas of ischemia to minimize adverse effects of therapy on adjacent normal parenchyma.
Shen
Fanxia
F
University of California, San Francisco, Department of Anesthesia and Perioperative Care, 1001 Potrero Ave., San Francisco, CA 94110, USA.
Su
Hua
H
Fan
Yongfeng
Y
Chen
Yongmei
Y
Zhu
Yiqian
Y
Liu
Weizhong
W
Young
William L
WL
Yang
Guo-Yuan
GY
D000818:Animals; D017209:Apoptosis; D015687:Cell Hypoxia; D000229:Dependovirus / Q000235:genetics*; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000627:therapeutic use*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D020244:Infarction, Middle Cerebral Artery / Q000628:therapy*; D002546:Ischemic Attack, Transient / Q000628:therapy*; D007763:Lac Operon; D008297:Male; D051379:Mice; D009474:Neurons / Q000473:pathology; D011993:Recombinant Fusion Proteins / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D011993:Recombinant Fusion Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A