Long-term proliferation and dopaminergic differentiation of human mesencephalic neural precursor cells

We report on generation of dopamine neurons from long-term cultures of huma n fetal mesencephalic precursor cells. These CNS precursor cells were succe ssfully expanded in vitro using the mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Incubation of these cultures in 3% atmospheric oxygen resulted in higher cellular yields than room air. Follow ing incubation in differentiation media containing interleukin (IL)-1b (IL- 1b), IL-11, leukemia inhibitory factor (LIF), and glial cell line-derived n eurotrophic factor (GDNF), up to 1% of the precursor cells converted into c ells immunoreactive for tyrosine hydroxylase (TH), a marker for dopamine ne urons. The TH immunoreactive cells exhibited morphological and functional p roperties characteristic of dopamine neurons in culture. These precursor ce lls might serve as a useful source of human dopamine neurons for studying t he development and degeneration of human dopamine neurons and may further s erve as a continuous, on-demand source of cells for therapeutic transplanta tion in patients with Parkinson's disease. (C) 2001 Academic Press.