Retinal Pigment Epithelial Cells Differentiated from Primate Embryonic Stem Cells

Abstract

Abstract: : Purpose: Embryonic stem (ES) cells have the pluripotency to differentiate into various cell types. We previously described a stromal cell-derived inducing activity (SDIA), which induces the differentiation of the neural cells from the mouse ES cells. We conducted this study to determine whether the retinal pigment epithelial (RPE) cells can be differentiated and expanded from the cynomolgus monkey ES cells. Methods: To induce the differentiation of the RPE cells from the primate ES cells, we applied the SDIA differentiation method to the primate ES cells with a few modifications. The primate ES cells were maintained and expanded in an undifferentiated state. Collected ES cells were co-cultured with the stromal cells in the differentiating medium. To selectively expand the pigment epithelial cells derived from the primate ES cells (ES-PEs), the patches of the ES-PEs were isolated under the dissecting microscope and re-plated onto the collagen-coated dishes. The characteristics of these ES-PEs were examined by RT-PCR and immunocytochemical analysis. Results: The pigment epithelial cells can be efficiently differentiated from the primate ES cells. We can selectively expand the patches of the ES-PEs as a single layer of the cells on the collagen-coated dishes. The ES-PEs exhibit a hexagonal morphology with heavy pigmentation, which is consistent with the appearance of the RPE cells. Moreover, the ES-PEs show several specific markers for the RPE cells by RT-PCR and immunocytochemical analysis. Conclusions: The morphological and molecular features of the ES-PEs strongly support the view that these cells are identical with the RPE cells. This differentiating method would provide an unlimited source of the RPE cells for the study of pathogenesis, drug development, and transplantation in the degenerative diseases such as age-related macular degeneration and retinitis pigmentosa.  

Keywords: retinal pigment epithelium • retinal culture • retinal development