Glial cell line-derived neurotrophic factor enhances in vitro differentiation of mid-/hindbrain neural progenitor cells to dopaminergic-like neurons.

Parkinson's disease (PD) affects the motor system through the degeneration of the dopaminergic neurons of the substantia nigra. The use of human embryonic stem cell (hESC)-derived human neural progenitor (hNP) cells provides a potential cell source for cell therapies and drug screens for future treatments. Glial cell line-derived neurotrophic factor (GDNF) is a known dopaminergic neuroprotectant agent; however, its potential role in neural differentiation remains largely unknown. Addition of 25 ng/ml GDNF to hNP cell differentiation media, over a 21-day period, induced a significantly (P < 0.05) greater portion of hNP cells to differentiate into dopaminergic neurons than non-GDNF cultures, 50% compared with 2.9% of cells expressing tyrosine hydroxylase (TH), respectively. The hNP cells exposed to GDNF selectively expressed dopamine receptors 1, 4, and 5 and were evoked to release dopamine with KCl. This is the first report of GDNF and leukemia inhibitory factor enriching hESC-derived hNP cells toward dopaminergic-like neurons.