In vitro model development of macular-like human RPE

Abstract

Purpose :
Age-related macular degeneration (AMD) is a leading cause of central vision loss and it remains an unmet medical need. The morphology and function of the retinal pigment epithelium (RPE) in the macula are compromised in AMD. Here we present a comprehensive characterization of a prolonged human RPE (iRPE) culture with a focus on macular features, to set the stage for probing mechanisms underlying dry AMD.

Methods : To generate a functional human RPE monolayer, we cultured RPE lineage-committed cells derived from human IPSCs in transwells or regular well plates for up to four months. Morphology, polarity, and marker expression were assessed using immunohistochemistry and confocal microscopy. The secretome and transcriptomic profiles of iRPE were assessed using Luminex platform technology and bulk RNA-Seq, respectively.

Results : RPE-specific marker expression and apical-basal polarity in prolonged RPE cultures were confirmed by immunofluorescence and confocal microscopy. We observed continued maturation of iRPE in morphology, pigmentation, and molecular signatures beyond two months. Notably, some features of macular RPE, such as hexagonal shape, were more prominent in transwells compared to well plates. Secretome analysis revealed apical vs basolateral differences, as well as differences between transwell- and well plate-cultured iRPE.

Conclusions :
Our prolonged human RPE culture in transwells exhibited macular-like features and may be a stepping stone to reproducing the tissue environment in vitro for elucidating AMD molecular mechanisms.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.