Efficient mini dCas13X mediated base editing for personalized treatment of Duchenne muscular dystrophy

Topic:

Translational Research

Poster Number: 311

Author(s):

Guoling Li, PhD, HuiGene Therapeutics Co., Ltd., Ming Jin, MD, Department of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China, Zhifang Li, PhD, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, China, Qingquan Xiao, PhD, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai, China, Jiajia Lin, MD, Department of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China, Dong Yang, PhD, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai, China, Yuanhua Liu, PhD, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai, China, Xing Wang, PhD, HuiGene Therapeutics Co., Ltd., Shanghai, China, Long Xie, PhD, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, China, Wenqin Ying, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai, China, Haoqiang Wang, HuiGene Therapeutics Co., Ltd., Shanghai, China, Erwei Zuo, PhD, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, China, Linyu Shi, PhD, HuiGene Therapeutics Co., Ltd., Shanghai, China, Ning Wang, PhD, Department of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China, Wanjin Chen, PhD, Department of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China, Chunlong Xu, PhD, Lingang Laboratory, Shanghai, China, Hui Yang, PhD, HuiGene Therapeutics Co., Ltd., Shanghai, China

Approximately 10% of monogenic diseases are caused by nonsense point mutations that generate premature termination codons (PTCs) leading to truncated protein and nonsense-mediated decay of 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, single adeno-associated virus (AAV)-packaged mxABE reached A-to-G editing rates up to 84% in vivo, much higher (at least 20 folds) than that reported in previous studies using other RNA editing modalities. Furthermore, mxABE restored robust expression of dystrophin protein to over 50% of wildtype level by PTC read-through in multiple muscle tissues. Importantly, systemic delivery of mxABE by AAV can also rescue both dystrophin expression (37% in diaphragm, 6% in tibialis anterior and 54% in heart muscle on average, compared to wildtype level) and muscle function, suggesting the clinical potential for mxABE in treatments for other monogenic diseases.