Retinal Pigment Epithelial Cell Conditioned Medium Enhances the Yield of RPE Cells Differentiated from Human Embryonic Stem Cells

Abstract

Geographic atrophy (GA) in patients with age-related macular degeneration (AMD) is characterized by the loss of retinal pigment epithelial (RPE) cells in the macular region. Human embryonic stem cells (hESC)-derived RPE have shown promise in cellular therapy for these diseases. However, the differentiation from hESC is a very lengthy process with an initially low RPE yield. The purpose of this study was to determine whether polarized hESC-RPE conditioned medium (CM) could improve the yield of RPE differentiated from hESC and to identify the mechanism of this effect. Two hESC lines, hES3 and H9, were differentiated into RPE by culturing in CM or regular medium for up to 8 weeks. We found substantially more pigmented cells in CM based on surface area quantification, and Q-RT PCR showed significantly higher expression of RPE-specific genes in the H9 and hES3 cells cultured in CM. The results indicated that CM increased the yield of RPE cells differentiated from H9 and hES3 lines via increased RPE colony formation and proliferation. These findings may be beneficial to the manufacturing process for future clinical studies.