Abstract
Purpose :
We have reported previously that retinal pigment epithelium (RPE) differentiated from induced pluripotent stem cells (iPSC) generated from fibroblasts of patients with age-related macular degeneration (AMD) exhibit a retinal degenerative phenotype and a distinct transcriptome compared to age-matched controls. Since the genetic composition of the iPSC and RPE are inherited from fibroblasts we investigated whether differential behavior was present in the parental fibroblasts and iPSC prior to differentiation of the cell lines into RPE.
Methods :
Induced pluripotent stem cells (iPSCs) were generated from fibroblasts isolated from AMD patients or age-matched (normal) controls. Fibroblast, iPSC and iPSC-derived RPE cells from normal and AMD patient donors were studied with DNA microarrays and Seahorse analysis for mitochondrial functions.
Results :
Principal component analyses revealed no significant differences in the transcriptome of fibroblasts harvested from skin biopsies of AMD patients versus controls. After reprogramming, there was no significant difference in the transcriptome of iPSC generated from AMD versus normal donors. In contrast, hierarchical clustering analysis reveals that the transcriptome of iPSC-derived RPE segregated into two distinct clusters of AMD-derived cells versus controls. Interestingly, mitochondrial dysfunction in AMD-derived RPE was evident after approximately two months in culture. Moreover, these differences in mitochondrial dysfunction were not evident in the parental fibroblasts and iPSC. This study demonstrates an altered transcriptome and impaired mitochondrial function in RPE derived from AMD patients versus controls, and demonstrates these differences are not present in the original fibroblasts or iPSC.
Conclusions :
These results suggest that the initial pathological changes in RPE seen in AMD may develop only after fibroblasts and the subsequent iPSC are differentiated into RPE, and that mitochondrial function is significantly affected in these cells. Additional study is required to advance the current understandings of the etiology of AMD and the development of novel therapeutic targets.
This is a 2021 ARVO Annual Meeting abstract.