Abstract
Purpose :
Inherited retinal degenerations (IRDs) are a clinically and genetically heterogeneous group of blinding diseases characterized by progressive degeneration of photoreceptors. Most disease-causing mutations are rare, but many converge on common pathogenic pathways, raising hopes for mutation-agnostic neuroprotective strategies. In this study, we identify gene targets for neuroprotection in RHO-P23H disease, the most common cause of autosomal dominant retinitis pigmentosa in the USA, which triggers photoreceptor degeneration through endoplasmic reticulum (ER) stress.
Methods :
We conducted an in vivo genome-wide lentiviral CRISPR screen to analyze gene contributions to degeneration and their potential to protect photoreceptors in RHO-P23H knock-in mice. We overexpressed neuroprotective candidate genes (i.e., genes whose removal accelerated photoreceptor death in our CRISPR screen) via adeno-associated viruses in RHO-P23H knock-in mice. We analyzed electroretinograms (ERGs), visual cliff tests, and pupillary light responses to examine their ability to protect photoreceptors and rescue visual functions. Finally, we established RHO-P23H models in human retinal explant cultures to test the translational potential of neuroprotective candidate genes.
Results :
Ubiquitin fusion degradation 1 (Ufd1) and ubiquitously expressed prefoldin-like chaperone (Uxt) were among the top neuroprotective candidate genes in our in vivo CRISPR screen. We found that overexpression of Ufd1 or Uxt protects photoreceptors, rescues impairments in ERGs and visual behaviors in RHO-P23H knock-in mice, and supports photoreceptor survival in the P23H human retinal explant culture model by counteracting ER stress.
Conclusions :
Our study provides a comprehensive list of candidate genes for neuroprotection (and disease modifiers) in retinal degeneration and reveals the remarkable therapeutic potential of Ufd1 and Uxt gene augmentation.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.