Inductionn Of Dopamine Neurons From Human ES Cells And Engraftment In Cynomolgus Monkeys

Parkinson’s disease is a degenerative disorder of the central nervous system caused by degradation and death of dopamine-generating cells in the substantia nigra. The symptoms of this disease include muscle rigidity and shaking, slowness of movement, difficulty with talking and moving, and other problems. The insufficient activity of dopamine in striatum due to the degeneration of dopamingenic neurons leads to the movement-related problems when the quantity of dopamine is under the threshold. There is no way out to cure this disease useing conventional drug and surgery therapies because dopamine-generating cells are terminally differentiated neurons without any proliferation and self-repair abilities. Lindvall et al. has first reported that it alleviated the disease by transplanting the midbrain tissue from a8to9-week aborted fetus to the putamen nucleus in a Parkinson patient, which opened a new window of cell therapy.It has been considered as a promising treatment strategy that dopaminergic neurons derived from embryonic stem (ES) cells in vitro which were engrafted into patients would substitute the dead cells. In this thesis, a phased-induced method was applied to direct dopaminergic precursor differentiation of embryonic stem cells, in which, we first induced ES cells to high-purity specific neural stem cells, then added inducing factors such as FGF8, SHH and Purmorphane at different time points to activate signaling pathways and direct cells into A9dopaminergic fate. After spontaneous maturation, the induced dopaminergic precursors were transplanted into striatum in cynomolgus monkeys, and some engrafted cells were observed to differentiate into more mature stage of dopaminergic neurons one-month after transplantation. The method not only improves the purity of dopaminergic neuron precursor cells from embryonic stem cell, but also achieves a large amplification of neural precursor cells using suspension culture, which would provide sufficient seed cells. This strategy therein contributes to the development of cell-based therapies for Parkinson’s disease.