Abstract
Purpose :
The pathogenesis of X-linked retinoschisis (XLRS) remains unresolved, with no effective treatment approach and specific therapy time. Here, we aim to investigate the molecular defects of RS1-KI (R102W) mouse retinas at different time points and evaluate the suitable time to treat the disease.
Methods :
The Rs1-KI（R102W) mice were created by co-injection of zygotes with Cas9 mRNA and sgRNAs in CRISPR/Cas9 system targeting Rs1. Retinal OCT, H&E stain, Immunofluorescence (IF) staining, TEM ultrastructure, and ScRNA-seq were performed at P14 and P28.
Results :
OCT and H&E stain showed the R102W mouse retinas had schisis in inner nuclear layer(INL) with edema at P14, whereas schisis cavities showed as atrophic cystoid schisis at P28. IF stain showed that compared with the WT group, the thickness of rhodopsin was not significantly changed in outer segment (OS) layer of R102W group at P14. While at P28, the rhodopsin showed a remarkable reduction of thickness with an irregular arrangement in R102W group. The cone arrestin was mainly localized in cone OS in WT group at P14 and P28. while in R102W group, it was reduced in OS at P14 and mislocalized into cone somas at P28. The TEM images confirmed that the mitochondria of IS were adjacent to the plasma membrane dispersedly in R102W group at P14 which was similar to WT group at P14 and P28. whereas in R102W group at P28, the mitochondria filled the IS irregularly with an increase in amount. ScRNA-seq showed that the intercellular communications of retinal cells was quite different between R102W and WT retinas at P14 and P28, especially in signaling pathways of NT(retinal development related) and VISFATIN (photoreceptor survival related). The NT signaling was mainly concentrated in BC(bipolar cell) to AC(amacrine cell)/RPE at P14, and AC to BC/RPE was added at P28 in WT group, while in R102W group, there was no significant signals at P14 and concentrated only in AC to BC /RPE without BC outcoming signal at P28. The VISFATIN signaling also vanished between BC and AC in R102W group at P14 and P28, compared with WT group.
Conclusions :
The R102W mouse retinas showed a progressive pathological process in photoreceptors from P14 to P28, and the abnormal intercellular communication in NT and VISFATIN pathway may play an important role in the progress of XLRS. This work supports that treatment may be more effective at the early stage of XLRS, such as edema systoid schisis stage at P14.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.