Transplantation of adult neural progenitor cells transfected with Vascular Endothelial Growth Factor rescues grafted cells in the rat brain

Growth factors are currently evaluated as therapeutics in stroke and neurodegeneration. Besides direct neurotrophic effects, they promote proliferation, survival, and differentiation of both transplanted and endogenous neural precursor cells (NPCs). In the current study, we investigated whether NPCs expressing Vascular Endothelial Growth Factor VEGF-A165 are a useful vehicle for growth factor delivery after transplantation into the caudate putamen of the rat brain. We found an increased survival of adenovirally transfected NPCs after 11 days, but not after 24 hours or 4 days. Additional brain immunohistochemistry revealed increased expression of the endothelial cell marker PECAM-1 (CD31) after 24 hours, 4 day, and 11 days after transplantation. In conclusion, we show that the graft itself is a useful vehicle for growth factor delivery, promoting the survival of NPCs. Moreover, transplantation of VEGF-expressing NPCs supports angiogenesis in the brain, which may contribute to potential brain repair.