Human induced pluripotent stem cell-derived neurons improve motor asymmetry in a 6-hydroxydopamine-induced rat model of Parkinson's disease.

Objective: Since human embryonic stem cells and human fetal neural stem cells have immune rejection and ethical issues, recent advancements in induced pluripotent stem cells (iPS cells) provide new possibilities to study autologous cell therapy for Parkinson's disease (PD).

Methods: We isolated human skin fibroblasts from normal individuals and patients with PD; we generated iPS cells by transfecting these human skin fibroblasts with retroviral reprogramming factors of OCT4, SOX2, KLF4 and c-MYC and induced iPS cells to differentiate neural stem cells (NSCs) and then into neurons and dopamine neurons in vitro.

Results: We found that iPS cell-derived NSC transplant into the striatum of the 6-hydroxydopamine (OHDA)-induced PD rats improved their functional defects of rotational asymmetry at 4, 8, 12 and 16 weeks after transplantation. iPS cell-derived NSCs were found to survive and integrate into the brain of transplanted PD rats and differentiated into neurons, including dopamine neurons in vivo.

Conclusions: Transplantation of iPS cell-derived NSCs has therapeutic potential for PD. Our study provided experimental proof for future clinical application of iPS cells in cell-based treatment of PD.