Expression of mitofusin 2(R94Q) in a transgenic mouse leads to Charcot-Marie-Tooth neuropathy type 2A.

Published

Journal Article

Charcot-Marie-Tooth disease type 2A is an autosomal dominant axonal form of peripheral neuropathy caused by mutations in the mitofusin 2 gene. Mitofusin 2 encodes a mitochondrial outer membrane protein that participates in mitochondrial fusion in mammalian cells. How mutations in this protein lead to Charcot-Marie-Tooth disease type 2A pathophysiology remains unclear. We have generated a transgenic mouse expressing either a mutated (R94Q) or wild-type form of human mitofusin 2 in neurons to evaluate whether the R94Q mutation was sufficient for inducing a Charcot-Marie-Tooth disease type 2A phenotype. Only mice expressing mitofusin 2(R94Q) developed locomotor impairments and gait defects thus mimicking the Charcot-Marie-Tooth disease type 2A neuropathy. In these animals, the number of mitochondria per axon was significantly increased in the distal part of the sciatic nerve axons with a diameter smaller than 3.5 microm. Importantly, the analysis of R94Q transgenic animals also revealed an age-related shift in the size of myelinated axons leading to an over-representation of axons smaller than 3.5 microm. Together these data suggest a link between an increased number of mitochondria in axons and a shift in axonal size distribution in mitofusin 2(R94Q) transgenic animals that may contribute to their neurological phenotype.

Full Text

Duke Authors

Cited Authors

  • Cartoni, R; Arnaud, E; Médard, J-J; Poirot, O; Courvoisier, DS; Chrast, R; Martinou, J-C

Published Date

  • May 2010

Published In

Volume / Issue

  • 133 / Pt 5

Start / End Page

  • 1460 - 1469

PubMed ID

  • 20418531

Pubmed Central ID

  • 20418531

Electronic International Standard Serial Number (EISSN)

  • 1460-2156

International Standard Serial Number (ISSN)

  • 0006-8950

Digital Object Identifier (DOI)

  • 10.1093/brain/awq082

Language

  • eng