title: Mitochondria in amyotrophic lateral sclerosis: a trigger and a target.
abstract: Strong evidence shows that mitochondrial dysfunction is involved in amyotrophic lateral sclerosis (ALS), but despite the fact that mitochondria play a central role in excitotoxicity, oxidative stress and apoptosis, the intimate underlying mechanism linking mitochondrial defects to motor neuron degeneration in ALS still remains elusive. Morphological and functional abnormalities occur in mitochondria in ALS patients and related animal models, although their exact nature and extent are controversial. Recent studies postulate that the mislocalization in mitochondria of mutant forms of copper-zinc superoxide dismutase (SOD1), the only well-documented cause of familial ALS, may account for the toxic gain of function of the enzyme, and hence induce motor neuron death. On the other hand, mitochondrial dysfunction in ALS does not seem to be restricted only to motor neurons as it is also present in other tissues, particularly the skeletal muscle. The presence of this 'systemic' defect in energy metabolism associated with the disease is supported in skeletal muscle tissue by impaired mitochondrial respiration and overexpression of uncoupling protein 3. In addition, the lifespan of transgenic mutant SOD1 mice is increased by a highly energetic diet compensating both the metabolic defect and the motorneuronal function. In this review, we will focus on the mitochondrial dysfunction linked to ALS and the cause-and-effect relationships between mitochondria and the pathological mechanisms thought to be involved in the disease.
authors.affiliation: Laboratoire de Signalisations Moléculaires et Neurodégénérescence, U692 INSERM, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Dupuis
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Gonzalez de Aguilar
authors.forename: Hugues
authors.initials: H
authors.lastname: Oudart
authors.forename: Marc
authors.initials: M
authors.lastname: de Tapia
authors.forename: Luis
authors.initials: L
authors.lastname: Barbeito
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Loeffler
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D000818:Animals; D016923:Cell Death / Q000235:genetics; D019069:Cell Respiration / Q000235:genetics; D006801:Humans; D008928:Mitochondria / Q000201:enzymology* / Q000473:pathology; D028361:Mitochondrial Diseases / Q000150:complications* / Q000378:metabolism* / Q000503:physiopathology; D009046:Motor Neurons / Q000201:enzymology* / Q000473:pathology; D018482:Muscle, Skeletal / Q000201:enzymology / Q000503:physiopathology; D018384:Oxidative Stress / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1
chemical_list: C000606290:SOD1 protein, human; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1