Striated muscle-specific base editing enables correction of mutations causing dilated cardiomyopathy

• Published in: Nature communications Vol. 14; no. 1; p. 3714
• Main Authors: Grosch, Markus, Schraft, Laura, Chan, Adrian, Küchenhoff, Leonie, Rapti, Kleopatra, Ferreira, Anne-Maud, Kornienko, Julia, Li, Shengdi, Radke, Michael H., Krämer, Chiara, Clauder-Münster, Sandra, Perlas, Emerald, Backs, Johannes, Gotthardt, Michael, Dieterich, Christoph, van den Hoogenhof, Maarten M. G., Grimm, Dirk, Steinmetz, Lars M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22-06-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 13/106; 13/51; 38/23; 42/44; 45/100; 45/41; 45/91; 631/208/1516; 631/208/4041; 631/443/592/75/74; 64/60; Animal models; Animals; Cardiac muscle; Cardiomyocytes; Cardiomyopathy; Cardiomyopathy, Dilated - genetics; Cardiomyopathy, Dilated - metabolism; Cardiomyopathy, Dilated - therapy; Congestive heart failure; Coronary artery disease; CRISPR; Dilated cardiomyopathy; Editing; Gene Editing; Gene sequencing; Gene therapy; Genomes; Heart diseases; Heart failure; Heart transplantation; Humanities and Social Sciences; Localization; Mice; multidisciplinary; Muscles; Mutation; Myocardium - metabolism; Myocytes, Cardiac - metabolism; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Science; Science (multidisciplinary); Skeletal muscle; Transplantation; Vectors (Biology); Whole genome sequencing
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-39352-1

Dilated cardiomyopathy is the second most common cause for heart failure with no cure except a high-risk heart transplantation. Approximately 30% of patients harbor heritable mutations which are amenable to CRISPR-based gene therapy. However, challenges related to delivery of the editing complex and off-target concerns hamper the broad applicability of CRISPR agents in the heart. We employ a combination of the viral vector AAVMYO with superior targeting specificity of heart muscle tissue and CRISPR base editors to repair patient mutations in the cardiac splice factor
Rbm20
, which cause aggressive dilated cardiomyopathy. Using optimized conditions, we repair >70% of cardiomyocytes in two
Rbm20
knock-in mouse models that we have generated to serve as an in vivo platform of our editing strategy. Treatment of juvenile mice restores the localization defect of RBM20 in 75% of cells and splicing of RBM20 targets including TTN. Three months after injection, cardiac dilation and ejection fraction reach wild-type levels. Single-nuclei RNA sequencing uncovers restoration of the transcriptional profile across all major cardiac cell types and whole-genome sequencing reveals no evidence for aberrant off-target editing. Our study highlights the potential of base editors combined with AAVMYO to achieve gene repair for treatment of hereditary cardiac diseases.
Dilated cardiomyopathy is the second most common cause for heart failure. Here the authors combine CRISPR base editors with the muscle-targeting viral vector AAVMYO to repair patient mutations in the cardiac splice factor
Rbm20
 in two mouse models.