Mini-dCas13X-mediated RNA editing restores dystrophin expression in a humanized mouse model of Duchenne muscular dystrophy

作者：Li, Guoling; Jin, Ming; Li, Zhifang; Xiao, Qingquan; Lin, Jiajia; Yang, Dong; Liu, Yuanhua; Wang, Xing; Xie, Long; Ying, Wenqin; Wang, Haoqiang; Zuo, Erwei; Shi, Linyu; Wang, Ning^*; Chen, Wanjin^*; Xu, Chunlong^*; Yang, Hui^*

来源：Journal of Clinical Investigation, 2023, 133(3): e162809.

DOI：10.1172/JCI162809

• MUSCLE
• MECHANISMS

Approximately 10% of monogenic diseases are caused by nonsense point mutations that generate premature termination codons (PTCs), resulting in a truncated protein and nonsense-mediated decay of the mutant mRNAs. Here, we demonstrate a mini-dCas13X-mediated RNA adenine base editing (mxABE) strategy to treat nonsense mutation-related monogenic diseases via A-to-G editing in a genetically humanized mouse model of Duchenne muscular dystrophy (DMD). Initially, we identified a nonsense point mutation (c.4174C>T, p.Gln1392*) in the DMD gene of a patient and validated its pathogenicity in humanized mice. In this model, mxABE packaged in a single adeno-associated virus (AAV) reached A-to-G editing rates up to 84% in vivo, at least 20-fold greater than rates reported in previous studies using other RNA editing modalities. Furthermore, mxABE restored robust expression of dystrophin protein to over 50% of WT levels by enabling PTC read-through in multiple muscle tissues. Importantly, systemic delivery of mxABE by AAV also rescued dystrophin expression to averages of 37%, 6%, and 54% of WT levels in the diaphragm, tibialis anterior, and heart muscle, respectively, as well as rescued muscle function. Our data strongly suggest that mxABE-based strategies may be a viable new treatment modality for DMD and other monogenic diseases.

• 单位
  1; 中国科学院