Regenerative medicine for spinal cord injury utilizing iPS cells

Reports of functional recovery from spinal cord injury (SCI) after the transplantation of rat-fetus-derived neural stem/precursor cells (NS/PCs) and murine embryonic stem cells (ES cells) have raised great expectations for the successful clinical trial of stem cell transplantation therapy. However, the ethical issues concerning about destroying human embryos or fertilized oocytes to obtain such stem cells have been a major impediment to developing clinically useful stem cell sources and to use them in clinical applications. Recently, induced pluripotent stem cells (iPS cells), which can serve as a source of autologous cell transplantation, have been attracting a lot of attention as a clinically practical alternative to stem cells obtained directly from tissues. In this chapter, we outline the neural induction of murine and human iPS cells, their therapeutic efficacy in mouse and primate SCI models, and their safety in vivo.