Efficacy of exon-skipping therapy for DMD cardiomyopathy with mutations in actin binding domain 1

Naoko Shiba; Xiao Yang; Mitsuto Sato; Shin Kadota; Yota Suzuki; Masahiro Agata; Kohei Nagamine; Masaki Izumi; Yusuke Honda; Tomoya Koganehira; Hideki Kobayashi; Hajime Ichimura; Shinichiro Chuma; Junichi Nakai; Shugo Tohyama; Keiichi Fukuda; Daigo Miyazaki; Akinori Nakamura; Yuji Shiba

doi:10.1016/j.omtn.2023.102060

Efficacy of exon-skipping therapy for DMD cardiomyopathy with mutations in actin binding domain 1

Mol Ther Nucleic Acids. 2023 Oct 19:34:102060. doi: 10.1016/j.omtn.2023.102060. eCollection 2023 Dec 12.

Authors

Naoko Shiba^{1

2}, Xiao Yang¹, Mitsuto Sato³, Shin Kadota^{1

4}, Yota Suzuki¹, Masahiro Agata¹, Kohei Nagamine¹, Masaki Izumi¹, Yusuke Honda¹, Tomoya Koganehira¹, Hideki Kobayashi¹, Hajime Ichimura¹, Shinichiro Chuma⁵, Junichi Nakai⁶, Shugo Tohyama⁷, Keiichi Fukuda⁷, Daigo Miyazaki³, Akinori Nakamura⁸, Yuji Shiba^{1

4}

Affiliations

¹ Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan.
² Department of Pediatrics, Shinshu University, Matsumoto 390-8621, Japan.
³ Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto 390-8621, Japan.
⁴ Institute for Biomedical Sciences, Shinshu University, Matsumoto 390-8621, Japan.
⁵ Department of Regeneration Science and Engineering, Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
⁶ Graduate Schools of Dentistry, Tohoku University, Sendai 980-8575, Japan.
⁷ Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan.
⁸ Department of Clinical Research, National Hospital Organization Matsumoto Medical Center, Matsumoto 399-8701, Japan.

Abstract

Exon-skipping therapy is a promising treatment strategy for Duchenne muscular dystrophy (DMD), which is caused by loss-of-function mutations in the DMD gene encoding dystrophin, leading to progressive cardiomyopathy. In-frame deletion of exons 3-9 (Δ3-9), manifesting a very mild clinical phenotype, is a potential targeted reading frame for exon-skipping by targeting actin-binding domain 1 (ABD1); however, the efficacy of this approach for DMD cardiomyopathy remains uncertain. In this study, we compared three isogenic human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) expressing Δ3-9, frameshifting Δ3-7, or intact DMD. RNA sequencing revealed a resemblance in the expression patterns of mechano-transduction-related genes between Δ3-9 and wild-type samples. Furthermore, we observed similar electrophysiological properties between Δ3-9 and wild-type hiPSC-CMs; Δ3-7 hiPSC-CMs showed electrophysiological alterations with accelerated CaMKII activation. Consistently, Δ3-9 hiPSC-CMs expressed substantial internally truncated dystrophin protein, resulting in maintaining F-actin binding and desmin retention. Antisense oligonucleotides targeting exon 8 efficiently induced skipping exons 8-9 to restore functional dystrophin and electrophysiological parameters in Δ3-7 hiPSC-CMs, bringing the cell characteristics closer to those of Δ3-9 hiPSC-CMs. Collectively, exon-skipping targeting ABD1 to convert the reading frame to Δ3-9 may become a promising therapy for DMD cardiomyopathy.

Keywords: CaMKII; Duchenne muscular dystrophy; MT: oligonucleotides: therapies and applications; actin-binding domain; antisense oligonucleotide-mediated exon skipping; cardiomyopathy; desmin; dystrophin; hiPSC-CMs.