DUX4 Transcript Knockdown with Antisense 2'-O-Methoxyethyl Gapmers for the Treatment of Facioscapulohumeral Muscular Dystrophy.

Affiliation

Lim KRQ(1), Bittel A(2), Maruyama R(1), Echigoya Y(3), Nguyen Q(1), Huang Y(1), Dzierlega K(1), Zhang A(2), Chen YW(4), Yokota T(5).
Author information:
(1)Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada.
(2)Center for Genetic Medicine Research, Children's National Health System, Washington, DC 20010, USA.
(3)Laboratory of Biomedical Science, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
(4)Center for Genetic Medicine Research, Children's National Health System, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, School of Medicine and Health Science, George Washington University, Washington, DC 20052, USA. Electronic address: [Email]
(5)Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; Muscular Dystrophy Canada Research Chair, Edmonton, AB T6G2H7, Canada. Electronic address: [Email]

Abstract

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder characterized by a progressive, asymmetric weakening of muscles, starting with those in the upper body. It is caused by aberrant expression of the double homeobox protein 4 gene (DUX4) in skeletal muscle. FSHD is currently incurable. We propose to develop a therapy for FSHD using antisense 2'-O-methoxyethyl (2'-MOE) gapmers, to knock down DUX4 mRNA expression. Using immortalized patient-derived muscle cells and local intramuscular injections in the FLExDUX4 FSHD mouse model, we showed that our designed 2'-MOE gapmers significantly reduced DUX4 transcript levels in vitro and in vivo, respectively. Furthermore, in vitro, we observed significantly reduced expression of DUX4-activated downstream targets, restoration of FSHD signature genes by RNA sequencing, significant improvements in myotube morphology, and minimal off-target activity. This work facilitates the development of a promising candidate therapy for FSHD and lays down the foundation for in vivo systemic treatment studies.