Neuron-specific enolase expression in a rat model of radiation-induced brain injury following vascular endothelial growth factor-modified neural stem cell transplantation

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-modified 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,10μL(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 10μL 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.