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FARA Funded Research

Your generous support has funded all the research listed below.


For more information on FARA-funded research & scientists, please visit FARA Supported Research, Active Clinical Trials and the Featured Scientist.

Excision of expanded GAA repeats alleviates the molecular phenotype of Friedreich's ataxia

Friedreich's ataxia (FRDA) is an autosomal recessive neurological disease caused by expansions of guanine-adenine-adenine (GAA) repeats in intron 1 of the frataxin (FXN) gene. The expansion results in significantly decreased frataxin expression. We report that human FRDA cells can be corrected by zinc finger nuclease-mediated excision of the expanded GAA repeats. Editing of a single expanded GAA allele created heterozygous, FRDA carrier-like cells and significantly increased frataxin expression. This correction persisted during reprogramming of zinc finger nuclease-edited fibroblasts to induced pluripotent stem cells and subsequent differentiation into neurons. 

Read More: Excision of expanded GAA repeats alleviates the molecular phenotype of Friedreich's ataxia

A longitudinal study of the Friedreich Ataxia Impact Scale

Quality of life in Friedreich ataxia (FRDA) has been explored using various generic health status measurement tools, most commonly the Short Form Health Survey Version 2 (SF-36v2). The tool did not address many specific issues related to disease impact in people with FRDA. The Friedreich Ataxia Impact Scale (FAIS) was developed to examine clinically relevant areas in FRDA. The aims of the current study were to assess the relationship between the FAIS and clinical characteristics of FRDA, as well as to determine the responsiveness of the FAIS to change over one and two years.

Read More: A longitudinal study of the Friedreich Ataxia Impact Scale

Mechanism of Action of 2-Aminobenzamide HDAC Inhibitors in Reversing Gene Silencing in Friedreich's Ataxia

The genetic defect in Friedreich's ataxia (FRDA) is the hyperexpansion of a GAA•TTC triplet in the first intron of the FXN gene, encoding the essential mitochondrial protein frataxin. Histone post-translational modifications near the expanded repeats are consistent with heterochromatin formation and consequent FXN gene silencing. Using a newly developed human neuronal cell model, derived from patient-induced pluripotent stem cells, we find that 2-aminobenzamide histone deacetylase (HDAC) inhibitors increase FXN mRNA levels and frataxin protein in FRDA neuronal cells. However, only compounds targeting the class I HDACs 1 and 3 are active in increasing FXN mRNA in these cells. Structural analogs of the active HDAC inhibitors that selectively target either HDAC1 or HDAC3 do not show similar increases in FXN mRNA levels. To understand the mechanism of action of these compounds, we probed the kinetic properties of the active and inactive inhibitors, and found that only compounds that target HDACs 1 and 3 exhibited a slow-on/slow-off mechanism of action for the HDAC enzymes.

Read More: Mechanism of Action of 2-Aminobenzamide HDAC Inhibitors in Reversing Gene Silencing in Friedreich's Ataxia

Publication for open-label trial of Resveratrol in FA

Friedreich ataxia (FRDA) is due to a triplet repeat expansion in FXN, resulting in deficiency of the mitochondrial protein frataxin. Resveratrol is a naturally occurring polyphenol, identified to increase frataxin expression in cellular and mouse models of FRDA and has anti-oxidant properties. This open-label, non-randomized trial evaluated the effect of two different doses of resveratrol on peripheral blood mononuclear cell (PBMC) frataxin levels over a 12-week period in individuals with FRDA. Secondary outcome measures included PMBC FXN mRNA, oxidative stress markers, and clinical measures of disease severity.

Read more: An open-label trial in Friedreich ataxia suggests clinical benefit with high-dose resveratrol, without effect on frataxin levels

Iron loading site on the Fe-S cluster assembly scaffold protein is distinct from the active site

Iron-sulfur (Fe-S) cluster containing proteins are utilized in almost every biochemical pathway. The unique redox and coordination chemistry associated with the cofactor allows these proteins to participate in a diverse set of reactions, including electron transfer, enzyme catalysis, DNA synthesis and signaling within several pathways. Due to the high reactivity of the metal, it is not surprising that biological Fe-S cluster assembly is tightly regulated within cells. In yeast, the major assembly pathway for Fe-S clusters is the mitochondrial ISC pathway. Yeast Fe-S cluster assembly is accomplished using the scaffold protein (Isu1) as the molecular foundation, with assistance from the cysteine desulfurase (Nfs1) to provide sulfur, the accessory protein (Isd11) to regulate Nfs1 activity, the yeast frataxin homologue (Yfh1) to regulate Nfs1 activity and participate in Isu1 Fe loading possibly as a chaperone, and the ferredoxin (Yah1) to provide reducing equivalents for assembly.

Read More: Iron loading site on the Fe-S cluster assembly scaffold protein is distinct from the active site

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