Abstract
Retinal regenerative medicine is expected as one of the future treatments of obstinate retinal diseases. There are two strategies for the recovery of lost retinal function especially in the outer retina. One is retinal regeneration from intrinsic progenitor cells and another is retinal cell transplantation. As for retinal regeneration, we revealed that the Muller glia acquired the progenitor like property, proliferated and differentiated into retinal neurons including photoreceptor cells after retinal damage even in the adult mammalian retina. We could promote the proliferation with Wnt. Notably this photoreceptor regeneration was observed also in the retinal degeneration model mice. For cell transplantation, we need sufficient amount of specific types of cells. One of the solutions is the embryonic stem (ES) cell. We have established a feeder-free and serum-independent culture method that induces directed differentiation of primate ES cells (human and non-human) into mature retinal cells. The next step is to select the required cells out of undifferentiated cells that may cause tumors. Furthermore, modification of transplantation condition is needed, although recently the recovery of retinal function has been reported by transplantation of immature retinal cells in mice and a retinitis pigmentosa patient. Research of retinal cell transplantation entered the stage of confirmation of functional recovery. [J Physiol Sci. 2007;57 Suppl:S30]
