Actin Glutathionylation Increases in Fibroblasts of Patients with Friedreich's Ataxia: A potential role in the pathogenesis of the disease

Anna Pastore, Giulia Tozzi, Laura Maria Gaeta, Enrico Bertini, Valentina Serafini, Silvia Di Cesare, Valentina Bonetto, Filippo Casoni, Rosalba Carrozzo, Giorgio Federici, Fiorella Piemonte

Research output: Contribution to journalArticle

Abstract

Increasing evidence suggests that iron-mediated oxidative stress might underlie the development of neurodegeneration in Friedreich's ataxia (FRDA), an autosomal recessive ataxia caused by decreased expression of frataxin, a protein implicated in iron metabolism. In this study, we demonstrate that, in fibroblasts of patients with FRDA, the cellular redox equilibrium is shifted toward more protein-bound glutathione. Furthermore, we found that actin is glutathionylated, probably as a result of the accumulation of reactive oxygen species, generated by iron overload in the disease. Indeed, high-pressure liquid chromatography analysis of control fibroblasts in vivo treated with FeSO4 showed a significant increase in the protein-bound/free GSH ratio, and Western blot analysis indicated a relevant rise in glutathionylation. Actin glutathionylation contributes to impaired microfilament organization in FRDA fibroblasts. Rhodamine phalloidin staining revealed a disarray of actin filaments and a reduced signal of F-actin fluorescence. The same hematoxylin/eosin-stained cells showed abnormalities in size and shape. When we treated FRDA fibroblasts with reduced glutathione, we obtained a complete rescue of cytoskeletal abnormalities and cell viability. Thus, we conclude that oxidative stress may induce actin glutathionylation and impairment of cytoskeletal functions in FRDA fibroblasts.

Original languageEnglish
Pages (from-to)42588-42595
Number of pages8
JournalJournal of Biological Chemistry
Volume278
Issue number43
DOIs
Publication statusPublished - Oct 24 2003

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry

Cite this