Abstract
Purpose :
Induced pluripotent stem cell-derived retinal pigment epithelial cells (iPSC-derived RPE) have been investigated for use as a source for cell replacement in geographic atrophy. Here, we conducted a characterization study on iPSC-derived RPE cells from age-related macular degeneration (AMD) patients as well as from age-matched individuals with no history of AMD.
Methods :
Human iPSCs were generated from fibroblasts of 6 donors with atrophic AMD (4 donors) or 2 age-matched controls with no history of AMD by treating with reprogramming factors, Oct3/4, Sox-2, Klf4, and c-Myc method. Derived RPE cells were generated by culturing with RPE differentiation medium using established protocols. Immunocytochemistry, transepithelial electrical resistance (TEER) of monolayers, and phagocytosis were used to characterize iPSC-derived RPE cells. DNA microarray was used to observe the gene expression profile of all six lines of iPSC-derived RPE cells.
Results :
Morphology, immunocytochemistry, phagocytosis and TEER assays revealed characteristics of native RPE cells. The gene expression levels of a majority of the 22000 annotated genes were similar when comparing AMD vs. non-diseased donor derived iPSC-RPE cells. However, principal components analysis (PCA) and hierarchical clustering analysis in DNA Microarray study clearly differentiate RPE cells from AMD patients apart from those of non-diseased individuals. Moreover, gene expression profile analysis reveals changes in expression levels for 700 genes of 22,000 probes tested (3.1%) when comparing AMD iPSC-RPE cells to non-diseased donors. These altered genes are involved in many different metabolic and signal transduction pathways. Among the altered genes in RPE cells from AMD patients, the focal adhesion-PI3K-Akt-mTOR-signaling pathway ranked first in the number of genes involved and their statistical significance.
Conclusions :
Although iPSC-derived RPE cell characteristics are similar between AMD and non-diseased donors, there are distinct differences in gene expression profile between these 2 populations. The significance of these changes for the utilization of patient-specific RPE to treat geographic atrophy remains to be elucidated.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.