Neuroprotection Following Traumatic Brain Injury Using VEGF-165 Gene In Rat

Objective: Vascular endthelial growth factor (VEGF), produced by vascular endothelial cells, has been recognized as a one of the most important factor with angiogenesis, neuroprotection and nerve regeneration. Hypoxic in brain tissue due to traumatic brain injury (TBI) will induce the increased expression of VEGF. Researchers pointed out that the upgrade of VEGF expression on the experimental and clinical researches was evidenced the relationship between the VEGF and the neuroprotection. The present study was to investigate the expression level of VEGF in TBI on rat following a treatment of Ad-VEGF-165 gene applied to the injury sector using laser scanning confocal microscopy (LSCM), RT-PCR and Western blot, and the relationship between the expression level and the apoptosis, CT perfusion (CTP). This study provides both rationale and experiment evidences for neuroprotection after TBI using Ad-VEGF-165 gene.Materials and Methods:1. A recombinant adenoviral (rAd) vector carrying VEGF-165 which can be used for gene therapy in TBI was constructed, and its expression in vitro and in vivo was researched. There was an increased expression of VEGF in different time after a gene treatment by injected to the cortex of injury sector.The expression level of VEGF and apoptosis after TBI following a treatment of Ad-VEGF-165 gene was detected by immunofluorescence using LSCM.3. The dynamic CT perfusion imaging were obtained in different time on pre- and post-therapy of Ad-VEGF-165 gene to observe the changes of cerebral perfusion.Results:1. Ad-VEGF-165 gene was constructed successfully by recombinant techenic. RT-PCR and Western blot shows that the expression of VEGF mRNA and protein has been increased in injury sector after TBI with gene thearyp.2. A decreased apoptosis with increased VEGF expression observed by LSCM remarkably on 24h, 3d, 7d after TBI following an Ad-VEGF-165 gene therapy, and showed a close relationship between apoptosis and VEGF.3. The cerebral perfusion on CT perfusion imaging after TBI represents a lower CBF and CBV in early stage, and higher in 24h, 3d, 7d which indicates a hyperperfusion due to unsound hemodynamics after TBI. An improved cerebral perfusion was significant for TBI with gene therapy to build collateral circulation.Conclusions: VEGF expression in the TBI could be great associated with neuroprotection following brain harm due to hypoxia, and applying Ad-VEGF-165 to the cerebral cortex in injury sector would be an exercisable method to improve cerebral perfusion and come down apoptosis. This research provides both rationale and experiment evidences for designing high effectiveness way to the gene treatment of TBI. It lays foundation for the research on clinical application of angiogenic gene therapy of TBI.