Vision rescue via unconstrained in vivo prime editing in degenerating neural retinas
Huan Qin, Wenliang Zhang, Shiyao Zhang, Yuan Feng, Weihui Xu, Qi Jia, Qian Zhang, Chunxiu Xu, Shanshan Liu, Jia Zhang, Yushuang Lei, Wanqin Liu, Shuyu Feng, Jingjing Wang, Xuefei Fu, Zifen Xu, Ping Li, Kai Yao
Abstract
Retinitis pigmentosa (RP) is an inherited retinal dystrophy causing progressive and irreversible loss of retinal photoreceptors. Here, we developed a genome-editing tool characterized by the versatility of prime editors (PEs) and unconstrained PAM requirement of a SpCas9 variant (SpRY), referred to as PESpRY. The diseased retinas of Pde6b-associated RP mouse model were transduced via a dual AAV system packaging PESpRY for the in vivo genome editing through a non-NGG PAM (GTG). The progressing cell loss was reversed once the mutation was corrected, leading to substantial rescue of photoreceptors and production of functional PDE6β. The treated mice exhibited significant responses in electroretinogram and displayed good performance in both passive and active avoidance tests. Moreover, they presented an apparent improvement in visual stimuli-driven optomotor responses and efficiently completed visually guided water-maze tasks. Together, our study provides convincing evidence for the prevention of vision loss caused by RP-associated gene mutations via unconstrained in vivo prime editing in the degenerating retinas.