Modeling PRPF31 retinitis pigmentosa using retinal pigment epithelium and organoids combined with gene augmentation rescue

Abstract

AbstractMutations in the ubiquitously expressedpre-mRNA processing factor(PRPF)31gene, one of the most common causes of dominant form of Retinitis Pigmentosa (RP), lead to a retina-specific phenotype. It is uncertain which retinal cell types are affected and animal models do not clearly present the RP phenotype observed inPRPF31patients. Retinal organoids and retinal pigment epithelial (RPE) cells derived from human-induced pluripotent stem cells (iPSCs) provide potential opportunities for studying humanPRPF31-related RP. We demonstrate here that RPE cells carryingPRPF31mutations present important morphological and functional changes and thatPRPF31-mutated retinal organoids recapitulate the human RP phenotype, with a rod photoreceptor cell death followed by a loss of cones. The low level ofPRPF31expression may explain the defective phenotypes ofPRPF31-mutated RPE and photoreceptor cells, which were not observed in cells derived from asymptomatic patients or after correction of the pathogenic mutation by CRISPR/Cas9. Transcriptome profiles revealed differentially expressed and mis-spliced genes belonging to pathways in line with the observed defective phenotypes. The rescue of RPE and photoreceptor defective phenotypes byPRPF31gene augmentation provide the proof of concept for future therapeutic strategies.