EGF/bFGF promotes survival, migration and differentiation into neurons of GFP-labeled rhesus monkey neural stem cells xenografted into the rat brain

Stem cell replacement therapy is considered a promising treatment for diseases of the central nervous system. Improving the ratio of surviving transplanted cells and the efficiency of differentiation into functional neuronal cells are the most important issues related to research on neuroregenerative medicine. Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) have been reported to promote the proliferation and differentiation of neural stem cells (NSCs) in vitro, but whether they have the same effect in vivo is unclear. In this study, NSCs derived from rhesus monkey embryonic stem cells (ESCs) were resuspended in medium with or without EGF/bFGF and xenotransplanted into the rat striatum. No behavioral abnormalities or teratoma formation were observed in the recipient engrafted rats. GFP-labeled cells exhibited a higher survival rate and longer migration in the EGF/bFGF group than control group at 2 months after transplantation. Moreover, the percentages of Tuj1+ neurons and Map2+ neurons in the EGF/bFGF group were significantly higher than those in the control group, while the percentages of astrocytes and oligodendrocytes were significantly lower in the EGF/bGFG group than control group. These findings indicated that EGF/bFGF can promote protrusion of nerve fibers and the survival and neuronal differentiation of transplanted NSCs in the recipient brain, suggesting that EGF/bFGF has a potential application for stem cell therapy.