Therapeutic application of stem cell technology toward the treatment of Parkinson's disease

Parkinson's disease (PD) is one of the candidate diseases for cell transplantation therapy, since successful clinical experiments have accumulated using human fetal tissue grafting for PD patients. Although some grafted PD patients have shown drastic improvements, several issues still remain with regard to using human fetal tissue. This review highlights the recent advances in stem cell technology toward clinical applications using human pluripotent stem cells. In particular, pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells (iPSCs), are the focus as a source of cell transplantation therapy that can be used instead of human fetal tissues. Additionally, efficient methods for stem cell maintenance and differentiation have been developed and improved toward the clinical transition. These advances in the basic technologies have helped accelerate the realization of regenerative medicine. We also review the current topics regarding disease modeling and drug screening using iPSC technology. Finally, we also describe the future prospects of these stem cell research fields toward clinical application.