Induction of dopamine-releasing cells from primate embryonic stem cells enclosed in agarose microcapsules.

Dopamine-releasing cells derived from embryonic stem cells (ESCs) are potentially valuable in cell transplantation therapy for Parkinson's disease. There have been many recent investigations of the induction of dopamine-releasing cells from mouse and primate ESCs. However, there are major obstacles to application of dopamine-releasing ESC progeny to cell transplantation therapy, including host immune responses to transplanted cells and the difficulty of collecting dopamine-releasing cells from culture dishes undamaged. To overcome these obstacles, in the present study, cynomolgus monkey ES cell (cESC) aggregates enclosed in agarose microcapsules were cultured in 3 kinds of media: Glasgow minimum essential medium-based medium (GBM); GBM-containing conditioned medium of PA6 cells; and GBM supplemented with fibroblast growth factor (FGF)8, sonic hedgehog, and ascorbic acid (GBM(+)) under free-floating culture conditions. Of these 3 culture media, GBM(+) most efficiently induced dopamine-releasing cells. Addition of FGF8, sonic hedgehog, and ascorbic acid to the culture medium during culture days 10 to 15, days 12 to 15, and days 16 to 20, respectively, facilitated the generation of dopamine-releasing cells. Because various characteristics of cESCs are reported to be similar to those of human ESCs, we expect that the study using cESCs will provide useful information for cell transplantation therapy of Parkinson's disease.