A rock inhibitor promotes graft survival during transplantation of ips‐cell‐derived retinal cells

Abstract

Currently, retinal pigment epithelium (RPE) transplantation includes sheet and single‐cell transplantation, the latter of which includes cell death and may be highly immunogenic, and there are some issues to be improved in single‐cell transplantation. Y‐27632 is an inhibitor of Rho-associated protein kinase (ROCK), the downstream kinase of Rho. We herein investigated the effect of Y‐27632 in vitro on retinal pigment epithelium derived from induced pluripotent stem cells (iPS‐ RPE cells), and also its effects in vivo on the transplantation of iPS‐RPE cell suspensions. As a result, the addition of Y‐27632 in vitro showed suppression of apoptosis, promotion of cell adhesion, and higher proliferation and pigmentation of iPS‐RPE cells. Y‐27632 also increased the viability of the transplant without showing obvious retinal toxicity in human iPS‐RPE transplantation into monkey subretinal space in vivo. Therefore, it is possible that ROCK inhibitors can improve the engraftment of iPS‐RPE cell suspensions after transplantation.