HDAC6 is a therapeutic target in mutant GARS-induced Charcot-Marie-Tooth disease

Brain. 2018 Mar 1;141(3):673-687. doi: 10.1093/brain/awx375.

Abstract

Peripheral nerve axons require a well-organized axonal microtubule network for efficient transport to ensure the constant crosstalk between soma and synapse. Mutations in more than 80 different genes cause Charcot-Marie-Tooth disease, which is the most common inherited disorder affecting peripheral nerves. This genetic heterogeneity has hampered the development of therapeutics for Charcot-Marie-Tooth disease. The aim of this study was to explore whether histone deacetylase 6 (HDAC6) can serve as a therapeutic target focusing on the mutant glycyl-tRNA synthetase (GlyRS/GARS)-induced peripheral neuropathy. Peripheral nerves and dorsal root ganglia from the C201R mutant Gars mouse model showed reduced acetylated α-tubulin levels. In primary dorsal root ganglion neurons, mutant GlyRS affected neurite length and disrupted normal mitochondrial transport. We demonstrated that GlyRS co-immunoprecipitated with HDAC6 and that this interaction was blocked by tubastatin A, a selective inhibitor of the deacetylating function of HDAC6. Moreover, HDAC6 inhibition restored mitochondrial axonal transport in mutant GlyRS-expressing neurons. Systemic delivery of a specific HDAC6 inhibitor increased α-tubulin acetylation in peripheral nerves and partially restored nerve conduction and motor behaviour in mutant Gars mice. Our study demonstrates that α-tubulin deacetylation and disrupted axonal transport may represent a common pathogenic mechanism underlying Charcot-Marie-Tooth disease and it broadens the therapeutic potential of selective HDAC6 inhibition to other genetic forms of axonal Charcot-Marie-Tooth disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axonal Transport / genetics
  • Cells, Cultured
  • Charcot-Marie-Tooth Disease / genetics*
  • Charcot-Marie-Tooth Disease / physiopathology
  • Charcot-Marie-Tooth Disease / therapy*
  • Disease Models, Animal
  • Enzyme Inhibitors / therapeutic use
  • Ganglia, Spinal / cytology
  • Glycine-tRNA Ligase / genetics*
  • Histone Deacetylase 6 / genetics
  • Histone Deacetylase 6 / metabolism*
  • Hydroxamic Acids / therapeutic use
  • Indoles / therapeutic use
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Motor Neurons / drug effects
  • Motor Neurons / metabolism
  • Mutation / genetics*
  • Neural Conduction / genetics
  • Neuromuscular Junction / pathology
  • Neuromuscular Junction / physiopathology
  • Psychomotor Performance / physiology
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Tubulin / metabolism

Substances

  • Enzyme Inhibitors
  • Hydroxamic Acids
  • Indoles
  • RNA, Small Interfering
  • Tubulin
  • tubastatin A
  • HDAC6 protein, human
  • Histone Deacetylase 6
  • Glycine-tRNA Ligase