Neural mitochondrial Ca2+ capacity impairment precedes the onset of motor symptoms in G93A Cu/Zn-superoxide dismutase mutant mice Academic Article uri icon

Overview

MeSH Major

  • Calcium
  • Mitochondria
  • Motor Neuron Disease
  • Motor Neurons
  • Superoxide Dismutase

abstract

  • Mitochondrial respiratory chain dysfunction, impaired intracellular Ca2+ homeostasis and activation of the mitochondrial apoptotic pathway are pathological hallmarks in animal and cellular models of familial amyotrophic lateral sclerosis associated with Cu/Zn-superoxide dismutase mutations. Although intracellular Ca2+ homeostasis is thought to be intimately associated with mitochondrial functions, the temporal and causal correlation between mitochondrial Ca2+ uptake dysfunction and motor neuron death in familial amyotrophic lateral sclerosis remains to be established. We investigated mitochondrial Ca2+ handling in isolated brain, spinal cord and liver of mutant Cu/Zn-superoxide dismutase transgenic mice at different disease stages. In G93A mutant transgenic mice, we found a significant decrease in mitochondrial Ca2+ loading capacity in brain and spinal cord, as compared with age-matched controls, very early on in the course of the disease, long before the onset of motor weakness and massive neuronal death. Ca2+ loading capacity was not significantly changed in liver G93A mitochondria. We also confirmed Ca2+ capacity impairment in spinal cord mitochondria from a different line of mice expressing G85R mutant Cu/Zn-superoxide dismutase. In excitable cells, such as motor neurons, mitochondria play an important role in handling rapid cytosolic Ca2+ transients. Thus, mitochondrial dysfunction and Ca2+-mediated excitotoxicity are likely to be interconnected mechanisms that contribute to neuronal degeneration in familial amyotrophic lateral sclerosis.

publication date

  • March 2006

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1111/j.1471-4159.2006.03619.x

PubMed ID

  • 16478527

Additional Document Info

start page

  • 1349

end page

  • 61

volume

  • 96

number

  • 5