Abstract
Purpose :
To develop induced pluripotent stem cell (iPSC) derived retinal pigment epithelium (RPE) models of age-related macular degeneration (AMD) from patients with varying clinical phenotypes.
Methods :
We obtained the National Eye Institute (NEI) Integrative Biology Initiative (IBI) dataset of an AREDS2 clinical trial (NCT00345176) sub-population that consented and donated for iPSC generation. Reading Center grading data was utilized to assess clinical phenotype and AMD stage in both eyes throughout the AREDS2 trial period. Demographic (age, sex, and ethnicity) data was stratified across the varying groups.
Patient iPSCs were obtained from the New York Stem Cell Foundation (NYSCF). iPSCs from patients with no progression from intermediate AMD (intermediate) or those progressing to geography atrophy only (GA) were identified and were differentiated to RPE. Differentiated iPSC-RPE were characterized by morphology, Western blot, immunofluorescence, ELISA, and trans-epithelial electrical resistance (TEER).
Results :
Of the patients with iPSC lines and data availability, 31 patients showed no progression from baseline intermediate AMD, 8 advanced to GA only, 22 advanced to neovascular AMD (NV) only, and 8 advanced to bilateral GA and NV. Within this cohort, the average age of GA presentation was 75.8 ± 2.2 years, with an average age of final follow-up of 86.9 ± 1.5 years. The age at final follow-up within the intermediate AMD group was 80.0 ± 1.1 years, indicating that this population was younger than the GA population (p=0.0048).
iPSC differentiation towards RPE was successful across multiple cell lines (4 intermediate AMD, 1 GA only). Independent of clinical phenotype, iPSC-RPE exhibited characteristic RPE morphology: pigmented and cobblestoned morphology, and protein expression of BEST1, RPE65, MERTK, and CRALBP. Transwell culture of iPSC-RPE demonstrated formation of a strong barrier (TEER values >600 Ω-cm2), and polarized secretion of PEDF (apical: 35.96 ± 2.98 ng/mL, basal: 0.38 ± 0.10 ng/mL, n=3, p<0.001) and VEGF (apical 1.71 ± 0.07 ng/mL, basal 7.73 ± 0.70 ng/mL, n=3, p<0.001).
Conclusions :
The NEI AREDS2 IBI cohort represents varying stages of AMD that can be leveraged to generate iPSC-RPE models for AMD disease biology. These models will be utilized to develop gene and compound screening assays, including functional and phenotypic assays.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.