Induced pluripotent stem cell-derived neural stem cells: new hope for stroke?

Human induced pluripotent stem cells (iPSCs) have attracted increasing interest in the field of ischemic stroke therapy, due to the lack of ethical concerns and reduced risk of immune rejection. However, the safety and efficiency of the donor iPSC derivates in the ischemic brain challenged the therapeutic efficacy of iPSC transplantation. Studies have focused on improving the methods to induce neural derivates from iPSCs and on trying to determine how these cells and the host ischemic environment influence each other. A recent study by Yuan and colleagues reported that neural stem cells induced from human iPSCs using retinoic acid and serum-free medium showed stable neural phenotype. After acute transplantation into the ischemic stroke model, these cells survived, migrated into the ischemic penumbra, differentiated into mature neural cells and showed beneficial effects on functional recovery. Their findings take a clear step towards the clinical application of human iPSCs for ischemic stroke. A wide range of careful studies may be raised from their work, from basic research to preclinic, to develop the best therapy for ischemic stroke.