Generation of Induced Pluripotent Stem Cell Lines from Friedreich Ataxia Patients

Abstract

Friedreich ataxia (FRDA) is an autosomal recessive disorder characterised by neurodegeneration and cardiomyopathy. It is caused by a trinucleotide (GAA) repeat expansion in the first intron of the FXN gene that results in reduced synthesis of FXN mRNA and its protein product, frataxin. We report the generation of induced pluripotent stem (iPS) cell lines derived from skin fibroblasts from two FRDA patients. Each of the patient-derived iPS (FA-iPS) cell lines maintain the GAA repeat expansion and the reduced FXN mRNA expression that are characteristic of the patient. The FA-iPS cells are pluripotent and form teratomas when injected into nude mice. We demonstrate that following in vitro differentiation the FA-iPS cells give rise to the two cell types primarily affected in FRDA, peripheral neurons and cardiomyocytes. The FA-iPS cell lines have the potential to provide valuable models to study the cellular pathology of FRDA and to develop high-throughput drug screening assays. We have previously demonstrated that stable insertion of a functional human BAC containing the intact FXN gene into stem cells results in the expression of frataxin protein in differentiated neurons. As such, iPS cell lines derived from FRDA patients, following correction of the mutated gene, could provide a useful source of immunocompatible cells for transplantation therapy.

Rho/ROCK pathway is essential to the expansion, differentiation, and morphological rearrangements of human neural stem/progenitor cells induced by lysophosphatidic acid

“…The iPS (Foreskin) 4 clone 1 and clone 2, abbreviated iPS1 and iPS2 ( 42 ), and the hESC line ENVY (ES Cell International) were cultured as described ( 43,44 ). Neuronal induction by noggin (R and D, 500 ng/ml) was performed as described in ( 11 ).…”

Recent advances in modelling of cerebellar ataxia using induced pluripotent stem cells

“…None of these studies have yet successfully recapitulated the specific cerebellar neuronal dysfunction and degeneration known to characterize these conditions. In human iPSC-based studies of FRDA, which is caused by an intronic repeat expansion in the FXN gene encoding Frataxin, disease-relevant phenotypes such as reduced Frataxin mRNA and protein levels as well as mitochondrial defects were observed in cardiomyocytes and peripheral sensory neurons, two of the affected cell types in FRDA [33][34][35][36] . In the case of A-T, chromosomal instability and cell cycle checkpoint defects, resulting from mutations in the ATM gene encoding ataxia-telangiectasia mutated (ATM) protein, have been found to reduce the efficiency of the reprogramming of A-T iPSCs 37 .…”

Improvements in Quality of Life in Individuals with Friedreich’s Ataxia after Participation in a 5-Year Program of Physical Activity: An observational Study Pre-Post Test Design, and Two Years Follow-Up

“…Apart from one previous study that found disability has an influence on work and social activities for people with FA [28], a comprehensive literature search identified no quality of life studies in FA using standardized measures. In relation to this, Wilson et al [29] analyzed the impact of FA on quality of life, noting that late onset was one of the factors negatively associated with quality of life, but also that there were limitations associated with the use of SF-36 V2 in the FA population [12]. Indeed, Delatycki [30] commented that there is a critical need for accurate measurement tools to detect such subtle benefits but that generic questionnaires, such as the SF-36, may not provide appropriate primary outcome measures in FA clinical trials.…”

“…For example, the generation of induced pluripotent stem cell lines derived from FA patients, following correction of the mutated gene, could provide a useful source of immune-compatible cells for transplantation therapy [12]. However, rehabilitation and physical therapy still play a dominant role in the clinical management of FA patients [13].…”