Improvement of muscle strength in a mouse model for congenital myopathy treated with HDAC and DNA methyltransferase inhibitors

Elife. 2022 Mar 3;11:e73718. doi: 10.7554/eLife.73718.

Abstract

To date there are no therapies for patients with congenital myopathies, muscle disorders causing poor quality of life of affected individuals. In approximately 30% of the cases, patients with congenital myopathies carry either dominant or recessive mutations in the ryanodine receptor 1 (RYR1) gene; recessive RYR1 mutations are accompanied by reduction of RyR1 expression and content in skeletal muscles and are associated with fiber hypotrophy and muscle weakness. Importantly, muscles of patients with recessive RYR1 mutations exhibit increased content of class II histone deacetylases and of DNA genomic methylation. We recently created a mouse model knocked-in for the p.Q1970fsX16+ p.A4329D RyR1 mutations, which are isogenic to those carried by a severely affected child suffering from a recessive form of RyR1-related multi-mini core disease. The phenotype of the RyR1 mutant mice recapitulates many aspects of the clinical picture of patients carrying recessive RYR1 mutations. We treated the compound heterozygous mice with a combination of two drugs targeting DNA methylases and class II histone deacetylases. Here, we show that treatment of the mutant mice with drugs targeting epigenetic enzymes improves muscle strength, RyR1 protein content, and muscle ultrastructure. This study provides proof of concept for the pharmacological treatment of patients with congenital myopathies linked to recessive RYR1 mutations.

Keywords: congenital myopathy; epigenetic enzymes; medicine; mouse; muscle function; ryanodine receptor mutations; treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA / metabolism
  • Disease Models, Animal
  • Histone Deacetylases / genetics
  • Histone Deacetylases / metabolism
  • Humans
  • Methyltransferases / metabolism
  • Mice
  • Muscle Strength / genetics
  • Muscle, Skeletal / metabolism
  • Muscular Diseases*
  • Mutation
  • Myotonia Congenita* / drug therapy
  • Myotonia Congenita* / genetics
  • Quality of Life
  • Ryanodine Receptor Calcium Release Channel / genetics
  • Ryanodine Receptor Calcium Release Channel / metabolism

Substances

  • Ryanodine Receptor Calcium Release Channel
  • DNA
  • Methyltransferases
  • Histone Deacetylases

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.