For cell replacement therapies of retinal diseases, the most-needed cells are retinal pigment epithelial cells and photoreceptor cells; lens cells are needed for replacement of the cataract. Stromal cell-derived inducing activity induces the differentiation of mouse embryonic stem (ES) cells into neural cells, including midbrain tyrosine hydroxylase-positive dopaminergic neurons, and ocular cells; the method also works with primate ES cells. We describe the methods to induce retinal pigment epithelial and lens cells from monkey ES cells using stromal cell-derived inducing activity and show the characteristics of those cells in vitro and in vivo.
