Pigmentation level of human iPSC-derived RPE does not indicate a specific gene expression profile

Abstract

Retinal pigment epithelium (RPE) cells show heterogeneous level of pigmentation when cultured in vitro. To know whether their color in appearance indicates functional qualities of the RPE, especially in terms of clinical use for cell transplantation, we analyzed the correlation between the color intensities and the gene expression profile of human-induced pluripotent stem cell-derived RPE cells (iPSC-RPE) at single cell level. For this purpose, we utilized our recent invention, Automated Live imaging and cell Picking System (ALPS), which enabled photographing each cell before RNA-sequencing analysis to profile the gene expression of each cell. While our iPSC-RPE were categorized in 4 clusters by gene expression, the color intensity of iPSC-RPE did not project any specific gene expression profiles, suggesting the degree of pigmentation of iPSC-RPE in vitro does not specifically correlate with quality metrics for clinical use.