Disabled early recruitment of antioxidant defenses in Friedreich's ataxia

Karine Chantrel-Groussard (1, 2) , Vanna Geromel (1, 2) , Hélène Puccio (3) , Michel Koenig (3) , Arnold Munnich (1, 2) , Agnès Rötig (1, 2) , Pierre Rustin (1, 2)

1 Inserm U393 - Handicaps génétiques de l'enfant
2 Hôpital Necker - Enfants Malades [AP-HP]
3 IGBMC - Institut de génétique et biologie moléculaire et cellulaire

Friedreich's ataxia (FRDA) results from a generalized deficiency of mitochondrial iron-sulfur protein activity ascribed to mitochondrial iron overload. However, iron overload appears to be a late event in the disease. Here we show that neither superoxide dismutases nor the import iron machinery was induced by an endogenous oxidative stress in FRDA patients' fibroblasts in contrast to control cells. Superoxide dismutase activity was not induced in the heart of conditional frataxin-KO mice either. This suggests that continuous oxidative damage to iron-sulfur clusters, resulting from hampered superoxide dismutase signaling, is causative of the mitochondrial deficiency and long term mitochondrial iron overload occurring in FRDA.

Domaines: Biochimie, Biologie Moléculaire

Karine Chantrel-Groussard, Vanna Geromel, Hélène Puccio, Michel Koenig, Arnold Munnich, et al.. Disabled early recruitment of antioxidant defenses in Friedreich's ataxia. Human Molecular Genetics, 2001, 10 (19), pp.2061-2067. ⟨10.1093/hmg/10.19.2061⟩. ⟨hal-04093208⟩