Safeguarding genome integrity during gene-editing therapy in a mouse model of age-related macular degeneration

• Published in: Nature communications 2022-12, Vol.13 (1), p.7867-7867, Article 7867
• Main Authors: Yin, Jianhang, Fang, Kailun, Gao, Yanxia, Ou, Liqiong, Yuan, Shaopeng, Xin, Changchang, Wu, Weiwei, Wu, Wei-wei, Hong, Jiaxu, Yang, Hui, Hu, Jiazhi
• Format: Article
• Language: English
• Subjects: 45/22; 45/23; 631/337/1427/2122; 631/61/201/2110; 64/60; 692/308/2778; 82/80; Age; Age related diseases; Animals; Chromosome translocations; CRISPR; CRISPR-Cas Systems - genetics; Editing; Eye diseases; Gene disruption; Gene Editing; Genetic modification; Genetic Therapy; Genome editing; Genomes; Health services; Humanities and Social Sciences; Macular degeneration; Macular Degeneration - genetics; Macular Degeneration - therapy; Mice; multidisciplinary; Retinal cells; Science; Science (multidisciplinary); Translocation, Genetic; Vascularization
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-35640-4

Ensuring genome safety during gene editing is crucial for clinical translation of the high-efficient CRISPR-Cas9 toolbox. Therefore, the undesired events including chromosomal translocations, vector integrations, and large deletions arising during therapeutic gene editing remain to be adequately addressed or tackled in vivo. Here, we apply CRISPR-Cas9TX in comparison to CRISPR-Cas9 to target Vegfa for the treatment of age-related macular degeneration (AMD) disease in a mouse model. AAV delivery of both CRISPR-Cas9 and CRISPR-Cas9TX can efficiently inhibit laser-induced neovascularization. Importantly, Cas9TX almost eliminates chromosomal translocations that occur at a frequency of approximately 1% in Cas9-edited mouse retinal cells. Strikingly, the widely observed AAV integration at the target Vegfa site is also greatly reduced from nearly 50% of edited events to the background level during Cas9TX editing. Our findings reveal that chromosomal structural variations routinely occur during in vivo genome editing and highlight Cas9TX as a superior form of Cas9 for in vivo gene disruption. Undesired chromosomal translocations, vector integrations, and large deletions remain a problem for therapeutic gene editing in vivo. Here, the authors compare the CRISPR-Cas9TX variant with CRISPR-Cas9 and show elimination of chromosomal translocations and reduction of AVV integration when targeting Vegfa for the treatment of age-related macular degeneration in a mouse model.