Kang-Chieh Huang 1 , 2 , 3 , Mong-Lien Wang 1 , 2 , 4 , 5 , Shih-Jen Chen 4 , 6 , Jean-Cheng Kuo 7 , 8 , Won-Jing Wang 7 , Phan Nguyen Nhi Nguyen 1 , 2 , Karl J. Wahlin 9 , Jyh-Feng Lu 10 , Audrey A. Tran 11 , Michael Shi 11 , Yueh Chien 1 , Aliaksandr A. Yarmishyn 1 , Ping-Hsing Tsai 1 , 2 , Tien-Chun Yang 1 , 2 , Wann-Neng Jane 12 , Chia-Ching Chang 13 , Chi-Hsien Peng 14 , Thorsten M. Schlaeger 11 , ∗ , Shih-Hwa Chiou 1 , 2 , 4 , 6 , 15 , ∗∗
24 October 2019
X-linked juvenile retinoschisis (XLRS), linked to mutations in the RS1 gene, is a degenerative retinopathy with a retinal splitting phenotype. We generated human induced pluripotent stem cells (hiPSCs) from patients to study XLRS in a 3D retinal organoid in vitro differentiation system. This model recapitulates key features of XLRS including retinal splitting, defective retinoschisin production, outer-segment defects, abnormal paxillin turnover, and impaired ER-Golgi transportation. RS1 mutation also affects the development of photoreceptor sensory cilia and results in altered expression of other retinopathy-associated genes. CRISPR/Cas9 correction of the disease-associated C625T mutation normalizes the splitting phenotype, outer-segment defects, paxillin dynamics, ciliary marker expression, and transcriptome profiles. Likewise, mutating RS1 in control hiPSCs produces the disease-associated phenotypes. Finally, we show that the C625T mutation can be repaired precisely and efficiently using a base-editing approach. Taken together, our data establish 3D organoids as a valid disease model.
Chiou, Schlaeger, and colleagues use hiPSC-derived retinal organoids to model X-linked juvenile retinoschisis. They show that patient hiPSC-derived retinal organoids replicate key pathologies observed in patients, including retinal splitting and photoreceptor deficit. The observed abnormalities were normalized in organoids derived from isogenic CRISPR/Cas9 gene-corrected hiPSCs. This validated XLRS in vitro model could be used to test and optimize therapeutic approaches.