Mavacamten for 4 weeks does not improve the condition of mice models of nebulin-related nemalin myopathy

In muscle fibers from individuals with nebulin-related nemaline myopathy (NEB-NM) and in NEB-NM mouse models, the proportion of myosin in the disordered relaxed state and ATP consumption are abnormally increased, accompanied by a reshuffling of the energy proteome of these cells.

  • Mavacamten, which reduces the amount of myosin in the disordered relaxed state in hypertrophic cardiomyopathy, normalizes ATP consumption in skeletal muscle fibers from patients with NEB-NM.
  • Administered for four weeks to NebKO mice, it did not improve the clinical and histological phenotype of the mice (in contrast to what was observed in Laing myopathy).
  • While it caused changes in the proteome, it did not alter the energy proteome of the mice.

 

Myosin ATPase inhibition fails to rescue the metabolically dysregulated proteome of nebulin-deficient muscle. Laitila J, Seaborne RAE, Ranu N et al. J Physiol. 2024 Aug 31.