Recombinant AAV1 mediated vascular endothelial growth factor gene expression promotes angiogenesis and improves neural function: experiment with rats

To investigate the therapeutic effect of vascular endothelial growth factor (VEGF) gene expression mediated by recombinant AAV1 (rAAV1) vector in brain ischemia and the mechanism thereof. Sixty-four SD rats were randomly divided into 2 equal groups and received intra-ventricular injection with rAAV1-VEGF or rAAV1-lacZ as controls. 21 days later the rats underwent transient middle cerebral artery occlusion (MCAO). Neurological severity score (NSS) was recorded 1, 2, 3, 7, 14, and 21 days after MCAO. 48 rats were sacrificed 21 days after MCAO and brains were taken out from 48 rats. Immune quantitative analysis was used to identify the quantity of VEGF expression. Immunohistochemistry was used to identify the site of VEGF expression. Immunofluorescence double labeling of von Willebrand factor (vWF) and 5-bromodeoxy-uridine (BrdU) was performed to detect the proliferation of endothelial cells. Fluorescein isothiocyanate (FITC)-dextran was infused into the caudal vein of 8 rats from each group and then the rats we