Comparison of stem-cell derived retinal pigment epithelia (RPE) with human fetal retina pigment epithelium

Retinal Pigment Epithelium (RPE) derived from two human embryonic stem cell lines, H1 and H9, were compared with human fetal RPE (hfRPE) using RNA-seq. Nominally, the transcriptome of H1-derived RPE showed greater overlap with hfRPE. For cells maintained in the medium used to differentiate RPE, 6.2% (H1-RPE) and 4.2% (H9-RPE) of the transcripts were expressed in amounts that were statistically different from hfRPE (false discovery rate: 5%). After adaptation to the serum-free medium, SFM-1, only 1.0 % (H1-RPE) and 1.9% (H9-RPE) were expressed in amounts that were statistically different. For RPE signature genes, statistical differences were observed for 1.0 % (H1-RPE) and 1.9% (H9-RPE) of the transcripts. For some barrier-function related mRNAs the statistical differences were greater than these small differences would predict. For adhesion proteins and plasma membrane transporters, the differences were as great as 6.9% and 4.3%, respectively. After adaptation to SFM-1, the statistical differences between H1- and H9-RPE were only 0.4% for all transcripts, 1.4% for signature genes, and 0.7% for membrane transporters. No statistical differences were observed for the transcripts related to tight junctions, adhesion junctions or ion channels. In summary, SFM-1 promoted the maturation of stem cell-derived RPE, and the statistical difference between two stem cell lines was minimal.