Efficient precise in vivo base editing in adult dystrophic mice

• DOI: 10.1038/s41467-021-23996-y
• Publication Date: 2021-06-17T10:03:09Z
• Authors: Li Xu; Chen Zhang; Haiwen Li; Peipei Wang; Yandi Gao; Nahush A. Mokadam; Jianjie Ma; W. David Arnold; Renzhi Han
• Keywords: Gene Editing; 0301 basic medicine; Science; Q; Genetic Vectors; Muscle Fibers, Skeletal; Genetic Therapy; Dependovirus; Article; Cell Line; 3. Good health; Dystrophin; Muscular Dystrophy, Duchenne; Disease Models, Animal; Mice; 03 medical and health sciences; Mutation; Mice, Inbred mdx; Animals; Humans; RNA-Seq; CRISPR-Cas Systems; Muscle, Skeletal; RNA, Guide, Kinetoplastida

AbstractRecent advances in base editing have created an exciting opportunity to precisely correct disease-causing mutations. However, the large size of base editors and their inherited off-target activities pose challenges for in vivo base editing. Moreover, the requirement of a protospacer adjacent motif (PAM) nearby the mutation site further limits the targeting feasibility. Here we modify the NG-targeting adenine base editor (iABE-NGA) to overcome these challenges and demonstrate the high efficiency to precisely edit a Duchenne muscular dystrophy (DMD) mutation in adult mice. Systemic delivery of AAV9-iABE-NGA results in dystrophin restoration and functional improvement. At 10 months after AAV9-iABE-NGA treatment, a near complete rescue of dystrophin is measured in mdx4cv mouse hearts with up to 15% rescue in skeletal muscle fibers. The off-target activities remains low and no obvious toxicity is detected. This study highlights the promise of permanent base editing using iABE-NGA for the treatment of monogenic diseases.