Dopamine Cells Replaced by Stem Cells to Treat Parkinson's

Journal of Clinical Investigation, December 5, 2007

The progressive degeneration of brain cells known as dopamine (DA) cells eventually leads to the condition called Parkinson's disease (PD).

A promising therapeutic strategy may be the replacement of these cells. Despite the promising results observed in clinical trials, limited availability of human fetal mesencephalic tissue means that other sources of these cells are needed for routine DA cell--replacement therapy to be a possible.

Now, a new source for DA cells that provided marked benefit when transplanted into mice with a PD-like disease has been identified by Ernest Arenas and colleagues at the Karolinska Institue, Sweden.

By culturing them in the presence of a number of factors -- FGF2, sonic hedgehog, and FGF8 -- and engineering them to express Wnt5a, DA cells were derived from ventral midbrain (VM) neural stem cells/progenitors.

In contrast to the conventional FGF2 treatment, the new protocol produced 10-fold more DA cells. Further examination revealed that when transplanted into mice with PD-like disease, the cells initiated substantial cellular and functional recovery.

Embryonic stem cells have been eliminated as a potential source of DA cells due to their tendency to become cancerous. Using non-embryonic cells, the mice in the study did not develop tumors. The study results suggest that individuals with PD may be safely and efficiently treated with Wnt5a-treated neural stem cells.

The December 3rd issue of the Journal of Clinical Investigation has published the results of the study in an article titled, "Wnt5a-Treated Midbrain Neural Stem Cells Improve Dopamine Cell Replacement Therapy in Parkinsonian Mice".