Dopaminergic differentiation of grafted GFP transgenic neuroepithelial stem cells in the brain of a rat model of Parkinson's disease.

Neuroepithelial stem cells (NEPs) possess multipotent potential for self-renewal and neuronal differentiation. Using green fluorescent protein (GFP) positive NEPs, we explored, firstly, the survival and differentiation of grafted NEPs in the host rat and, secondly, whether or not transplantation of NEPs is a feasible therapeutic option for treating Parkinson's disease. NEPs were harvested from the neural tube of enhanced GFP transgenic embryos. In culture, GFP(+) NEPs generated abundant neurospheres and differentiated into both neurons and glia. When stereotaxically transplanted into the 6-hydroxydopamine (6-OHDA)-lesioned striatum of rats, NEPs survived and tyrosine hydroxylase (TH)-positive cells were detected in the graft. Furthermore, these grafted GFP(+) NEPs significantly ameliorated Parkinsonian behavioral symptoms compared with controls which were treated only with normal saline. Our results suggest that transplanted NEPs accomplish dopaminergic differentiation may be used for treating Parkinson's disease.