Developing Autologous Cell Therapy for Macular Degeneration Using Functional RPE Tissue Derived from Patient-specific iPS Cells

FARE Award Winner

Authors

• F Ruchi
• J Davis
• BS Jha
• V Khristov
• J Hartford
• F Hua
• Q Wan
• K Bharti

Abstract

RPE is a monolayer of cells located in back of the eye and maintain photoreceptor health and function. Its degeneration causes photoreceptor cell death leading to blinding eye diseases like AMD. It is one of the leading causes of blindness and there is no cure for the “dry” form of AMD. Preliminary work suggests that replacing the damaged RPE with an autologous RPE monolayer can provide potential therapy for dry AMD. In this study we develop protocols to generate functionally mature RPE from patient-derived iPS cells. A reporter iPS cell line expressing GFP under RPE specific promoter was used to optimize the differentiation protocol. This tri-phasic developmentally guided protocol uses the dual SMAD inhibition combined with canonical WNT and FGF inhibition to generate RPE-primed neuroectoderm. Differentiation to committed RPE needs an activation of canonical WNT and TGF-signaling pathways. To generate mature RPE monolayers, we induced primary cilium in committed RPE cells using known cilia inducers like aphidicolin and PGE2. The differentiation efficiency was analyzed using GFP and RPE-specific gene expressions. Generation of RPE-primed neuroectoderm is marked by increased expression of eye-field transcription factors. Increase in expression of PAX6, MITF and OTX2 brings the RPE primed neuroectoderm to committed RPE fate. Maturation of RPE monolayers is marked by upregulation of RPE maturation makers like RPE65. This differentiation protocol reproducibly makes RPE from healthy and AMD patient lines. This protocol is being used to develop clinicial-grade RPE from AMD patient iPS cells for a phase I clinical trial.

Scientific Focus Area: Stem Cell Biology

This page was last updated on Friday, March 26, 2021