摘要BACKGROUND:Previous studies have shown that transplantation of vascular endothelial growth factor (VEGF)-modified neural stem cells (NSC) provides better outcomes,compared with neural stem cells,in the treatment of brain damage.OBJECTIVE:To compare the effects of VEGF-modified NSC transplantation and NSC transplantation on radiation-induced brain injury,and to determine neuron-specific enolase (NSE) expression in the brain.DESIGN,TIME,AND SETTING:The randomized,controlled study was performed at the Linbaixin Experimental Center,Second Affiliated Hospital,Sun Yat-sen University,China from November 2007 to October 2008.MATERIALS:VEGF-medified C17.2 NSCs were supplied by Harvard Medical School,USA.Streptavidin-biotin-peroxidase-complex kit (Boster,China) and 5,6-carboxyfluorescein diacetate succinimidyl ester (Fluka,USA) were used in this study.METHODS:A total of 84 Sprague Dawley rats were randomly assigned to a blank control group (n=20),model group (n=20),NSC group (n=20),and a VEGF-modified NSC group (n=24).Rat models of radiation-induced brain injury were established in the model,NSC,and VEGF-modified NSC groups.At 1 week following model induction,10 μL (5×10~4 cells/μL) VEGF-modified NSCs or NSCs were respectively infused into the striatum and cerebral cortex of rats from the VEGF-modified NSC and NSC groups.A total of 10 μL saline was injected into rats from the blank control and model groups.MAIN OUTCOME MEASURES:NSE expression in the brain was detected by immunohistochemistry following VEGF-modified NSC transplantation.RESULTS:NSE expression was significantly decreased in the brains of radiation-induced brain injury rats (P＜0.05).The number of NSE-positive neurons significantly increased in the NSC and VEGF-modified NSC groups,compared with the model group (P＜0.05).NSE expression significantly increased in the VEGF-modified NSC group,compared with the NSC group,at 6 weeks following transplantation (P＜0.05).CONCLUSION:VEGF-modified NSC transplantation increased NSE expression in rats with radiation-induced brain injury,and the outcomes were superior to NSC transplantation.