Mitochondria and Iron: current questions

Bibbin T. Paul, David H. Manz, Frank M. Torti, and Suzy V. Torti; Expert Review of Hematology Vol. 0 , Iss. 0,0 doi:10.1080/17474086.2016.1268047

Several genetic diseases can result in disrupted iron-sulfur cluster biogenesis and severe mitochondrial iron overload. For example, point mutations or homozygous unstable GAA trinucleotide expansion in the FXN gene can result in Friedreich's ataxia (FRDA), an autosomal recessive disease characterized by severe neurodegeneration and cardiomyopathy. These manifestations of FRDA are caused by an accumulation of intra-mitochondrial iron, which decreases mitochondrial function and increases sensitivity to oxidative stress.
Mitochondria serve a key role in the synthesis and assembly of heme and Fe-S clusters, and are therefore essential for the delivery of iron to client proteins. Appropriate levels of iron, however, are also important for the proper function of the mitochondria. Conditions of iron deficiency or excess disrupt a myriad of mitochondrial functions. This interdependence between iron and mitochondria is best demonstrated by diseases that simultaneously disrupt mitochondrial iron and mitochondrial function, such as Frederich’s Ataxia, infantile mitochondrial complex II/III deficiency, neonatal oxidative phosphorylation deficiency, and sideroblastic anemia.
To develop effective treatment for pathologies leading to localized mitochondrial iron overload or deficiency, we will first need to develop a more detailed understanding of mitochondrial iron regulation. We anticipate substantial progress towards this goal in the next five years.

Amélioration des paramètres spatiotemporels de la marche par des chaussures orthopédiques dans l’ataxie de Friedreich

Bastien Roche, Isabelle Husson, Neurophysiologie Clinique/Clinical Neurophysiology, Volume 46, Issues 4–5, November 2016, Pages 276-277, ISSN 0987-7053, doi:10.1016/j.neucli.2016.09.098

Alors que l’évolution de l’ataxie s’oriente vers une instabilité plus importante, puis une perte de la marche, l’utilisation des chaussures orthopédiques permet d’améliorer, comparativement à la marche pieds nus, la stabilité et la fonctionnalité de la marche.