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Mosbach V, Puccio H. A multiple animal and cellular models approach to study frataxin deficiency in Friedreich Ataxia. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119809. [PMID: 39134123 DOI: 10.1016/j.bbamcr.2024.119809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 08/01/2024] [Accepted: 08/02/2024] [Indexed: 08/15/2024]
Abstract
Friedreich's ataxia (FA) is one of the most frequent inherited recessive ataxias characterized by a progressive sensory and spinocerebellar ataxia. The main causative mutation is a GAA repeat expansion in the first intron of the frataxin (FXN) gene which leads to a transcriptional silencing of the gene resulting in a deficit in FXN protein. The nature of the mutation (an unstable GAA expansion), as well as the multi-systemic nature of the disease (with neural and non-neural sites affected) make the generation of models for Friedreich's ataxia quite challenging. Over the years, several cellular and animal models for FA have been developed. These models are all complementary and possess their own strengths to investigate different aspects of the disease, such as the epigenetics of the locus or the pathophysiology of the disease, as well as being used to developed novel therapeutic approaches. This review will explore the recent advancements in the different mammalian models developed for FA.
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Affiliation(s)
- Valentine Mosbach
- Institut NeuroMyoGene-PGNM UCBL-CNRS UMR5261 INSERM U1315, Lyon, France
| | - Hélène Puccio
- Institut NeuroMyoGene-PGNM UCBL-CNRS UMR5261 INSERM U1315, Lyon, France.
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Nishiyama M, Kalambogias J, Imai F, Yang E, Lang S, de Nooij JC, Yoshida Y. Anatomical and functional analysis of the corticospinal tract in an FRDA mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601178. [PMID: 39005321 PMCID: PMC11244874 DOI: 10.1101/2024.06.28.601178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Friedreich's ataxia (FRDA) is one of the most common hereditary ataxias. It is caused by a GAA repeat in the first intron of the FXN gene, which encodes an essential mitochondrial protein. Patients suffer from progressive motor dysfunction due to the degeneration of mechanoreceptive and proprioceptive neurons in dorsal root ganglia (DRG) and cerebellar dentate nucleus neurons, especially at early disease stages. Postmortem analyses of FRDA patients also indicate pathological changes in motor cortex including in the projection neurons that give rise to the cortical spinal tract (CST). Yet, it remains poorly understood how early in the disease cortical spinal neurons (CSNs) show these alterations, or whether CSN/CST pathology resembles the abnormalities observed in other tissues affected by FXN loss. To address these questions, we examined CSN driven motor behaviors and pathology in the YG8JR FRDA mouse model. We find that FRDA mice show impaired motor skills, exhibit significant reductions in CSN functional output, and, among other pathological changes, show abnormal mitochondrial distributions in CSN neurons and CST axonal tracts. Moreover, some of these alterations were observed as early as two months of age, suggesting that CSN/CST pathology may be an earlier event in FRDA disease than previously appreciated. These studies warrant a detailed mechanistic understanding of how FXN loss impacts CSN health and functionality.
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Affiliation(s)
- Misa Nishiyama
- Burke Neurological Institute, White Plains, New York, United States
| | - John Kalambogias
- Burke Neurological Institute, White Plains, New York, United States
- Department of Neurology, Columbia University, New York, NY, USA
| | - Fumiyasu Imai
- Burke Neurological Institute, White Plains, New York, United States
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
| | - Emily Yang
- Burke Neurological Institute, White Plains, New York, United States
| | - Sonia Lang
- Burke Neurological Institute, White Plains, New York, United States
| | | | - Yutaka Yoshida
- Burke Neurological Institute, White Plains, New York, United States
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
- Neural Circuit Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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Perfitt TL, Huichalaf C, Gooch R, Kuperman A, Ahn Y, Chen X, Ullas S, Hirenallur-Shanthappa D, Zhan Y, Otis D, Whiteley LO, Bulawa C, Martelli A. A modified mouse model of Friedreich's ataxia with conditional Fxn allele homozygosity delays onset of cardiomyopathy. Am J Physiol Heart Circ Physiol 2024; 326:H357-H369. [PMID: 38038720 DOI: 10.1152/ajpheart.00496.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/02/2023]
Abstract
Friedreich's ataxia (FA) is an autosomal recessive disorder caused by a deficiency in frataxin (FXN), a mitochondrial protein that plays a critical role in the synthesis of iron-sulfur clusters (Fe-S), vital inorganic cofactors necessary for numerous cellular processes. FA is characterized by progressive ataxia and hypertrophic cardiomyopathy, with cardiac dysfunction as the most common cause of mortality in patients. Commonly used cardiac-specific mouse models of FA use the muscle creatine kinase (MCK) promoter to express Cre recombinase in cardiomyocytes and striated muscle cells in mice with one conditional Fxn allele and one floxed-out/null allele. These mice quickly develop cardiomyopathy that becomes fatal by 9-11 wk of age. Here, we generated a cardiac-specific model with floxed Fxn allele homozygosity (MCK-Fxnflox/flox). MCK-Fxnflox/flox mice were phenotypically normal at 9 wk of age, despite no detectable FXN protein expression. Between 13 and 15 wk of age, these mice began to display progressive cardiomyopathy, including decreased ejection fraction and fractional shortening and increased left ventricular mass. MCK-Fxnflox/flox mice began to lose weight around 16 wk of age, characteristically associated with heart failure in other cardiac-specific FA models. By 18 wk of age, MCK-Fxnflox/flox mice displayed elevated markers of Fe-S deficiency, cardiac stress and injury, and cardiac fibrosis. This modified model reproduced important pathophysiological and biochemical features of FA over a longer timescale than previous cardiac-specific mouse models, offering a larger window for studying potential therapeutics.NEW & NOTEWORTHY Previous cardiac-specific frataxin knockout models exhibit rapid and fatal cardiomyopathy by 9 wk of age. This severe phenotype poses challenges for the design and execution of intervention studies. We introduce an alternative cardiac-specific model, MCK-Fxnflox/flox, with increased longevity and delayed onset of all major phenotypes. These phenotypes develop to the same severity as previous models. Thus, this new model provides the same cardiomyopathy-associated mortality with a larger window for potential studies.
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Affiliation(s)
- Tyler L Perfitt
- Rare Disease Research Unit, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Claudia Huichalaf
- Rare Disease Research Unit, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Renea Gooch
- Rare Disease Research Unit, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Anna Kuperman
- Rare Disease Research Unit, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Youngwook Ahn
- Target Sciences, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Xian Chen
- Comparative Medicine, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Soumya Ullas
- Comparative Medicine, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Dinesh Hirenallur-Shanthappa
- Comparative Medicine, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Yutian Zhan
- Drug Safety Research and Development, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Diana Otis
- Drug Safety Research and Development, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Laurence O Whiteley
- Drug Safety Research and Development, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Christine Bulawa
- Rare Disease Research Unit, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
| | - Alain Martelli
- Rare Disease Research Unit, Worldwide Research, Development and Medical, Pfizer, Incorporated, Cambridge, Massachusetts, United States
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Sanz-Alcázar A, Britti E, Delaspre F, Medina-Carbonero M, Pazos-Gil M, Tamarit J, Ros J, Cabiscol E. Mitochondrial impairment, decreased sirtuin activity and protein acetylation in dorsal root ganglia in Friedreich Ataxia models. Cell Mol Life Sci 2023; 81:12. [PMID: 38129330 PMCID: PMC10739563 DOI: 10.1007/s00018-023-05064-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 11/16/2023] [Accepted: 11/25/2023] [Indexed: 12/23/2023]
Abstract
Friedreich ataxia (FA) is a rare, recessive neuro-cardiodegenerative disease caused by deficiency of the mitochondrial protein frataxin. Mitochondrial dysfunction, a reduction in the activity of iron-sulfur enzymes, iron accumulation, and increased oxidative stress have been described. Dorsal root ganglion (DRG) sensory neurons are among the cellular types most affected in the early stages of this disease. However, its effect on mitochondrial function remains to be elucidated. In the present study, we found that in primary cultures of DRG neurons as well as in DRGs from the FXNI151F mouse model, frataxin deficiency resulted in lower activity and levels of the electron transport complexes, mainly complexes I and II. In addition, altered mitochondrial morphology, indicative of degeneration was observed in DRGs from FXNI151F mice. Moreover, the NAD+/NADH ratio was reduced and sirtuin activity was impaired. We identified alpha tubulin as the major acetylated protein from DRG homogenates whose levels were increased in FXNI151F mice compared to WT mice. In the mitochondria, superoxide dismutase (SOD2), a SirT3 substrate, displayed increased acetylation in frataxin-deficient DRG neurons. Since SOD2 acetylation inactivates the enzyme, and higher levels of mitochondrial superoxide anion were detected, oxidative stress markers were analyzed. Elevated levels of hydroxynonenal bound to proteins and mitochondrial Fe2+ accumulation was detected when frataxin decreased. Honokiol, a SirT3 activator, restores mitochondrial respiration, decreases SOD2 acetylation and reduces mitochondrial superoxide levels. Altogether, these results provide data at the molecular level of the consequences of electron transport chain dysfunction, which starts negative feedback, contributing to neuron lethality. This is especially important in sensory neurons which have greater susceptibility to frataxin deficiency compared to other tissues.
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Affiliation(s)
- Arabela Sanz-Alcázar
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Elena Britti
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Fabien Delaspre
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Marta Medina-Carbonero
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Maria Pazos-Gil
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Jordi Tamarit
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Joaquim Ros
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Elisa Cabiscol
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain.
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Sayles NM, Napierala JS, Anrather J, Diedhiou N, Li J, Napierala M, Puccio H, Manfredi G. Comparative multi-omic analyses of cardiac mitochondrial stress in three mouse models of frataxin deficiency. Dis Model Mech 2023; 16:dmm050114. [PMID: 37691621 PMCID: PMC10581388 DOI: 10.1242/dmm.050114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
Cardiomyopathy is often fatal in Friedreich ataxia (FA). However, FA hearts maintain adequate function until advanced disease stages, suggesting initial adaptation to the loss of frataxin (FXN). Conditional cardiac knockout mouse models of FXN show transcriptional and metabolic profiles of the mitochondrial integrated stress response (ISRmt), which could play an adaptive role. However, the ISRmt has not been investigated in models with disease-relevant, partial decrease in FXN. We characterized the heart transcriptomes and metabolomes of three mouse models with varying degrees of FXN depletion: YG8-800, KIKO-700 and FXNG127V. Few metabolites were changed in YG8-800 mice, which did not provide a signature of cardiomyopathy or ISRmt; several metabolites were altered in FXNG127V and KIKO-700 hearts. Transcriptional changes were found in all models, but differentially expressed genes consistent with cardiomyopathy and ISRmt were only identified in FXNG127V hearts. However, these changes were surprisingly mild even at advanced age (18 months), despite a severe decrease in FXN levels to 1% of those of wild type. These findings indicate that the mouse heart has low reliance on FXN, highlighting the difficulty in modeling genetically relevant FA cardiomyopathy.
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Affiliation(s)
- Nicole M. Sayles
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY 10065, USA
- Neuroscience Graduate Program, Will Cornell Graduate School of Medical Sciences, 1300 York Ave, New York, NY 10065, USA
| | - Jill S. Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Josef Anrather
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY 10065, USA
| | - Nadège Diedhiou
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/Université de Strasbourg UMR7104, Inserm U1258, B. P. 163, 67404 Illkirch, France
| | - Jixue Li
- Department of Neurology, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hélène Puccio
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/Université de Strasbourg UMR7104, Inserm U1258, B. P. 163, 67404 Illkirch, France
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY 10065, USA
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Cotticelli MG, Xia S, Truitt R, Doliba NM, Rozo AV, Tobias JW, Lee T, Chen J, Napierala JS, Napierala M, Yang W, Wilson RB. Acute frataxin knockdown in induced pluripotent stem cell-derived cardiomyocytes activates a type I interferon response. Dis Model Mech 2023; 16:276639. [PMID: 36107856 PMCID: PMC9637271 DOI: 10.1242/dmm.049497] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 09/01/2022] [Indexed: 11/20/2022] Open
Abstract
Friedreich ataxia, the most common hereditary ataxia, is a neuro- and cardio-degenerative disorder caused, in most cases, by decreased expression of the mitochondrial protein frataxin. Cardiomyopathy is the leading cause of premature death. Frataxin functions in the biogenesis of iron-sulfur clusters, which are prosthetic groups that are found in proteins involved in many biological processes. To study the changes associated with decreased frataxin in human cardiomyocytes, we developed a novel isogenic model by acutely knocking down frataxin, post-differentiation, in cardiomyocytes derived from induced pluripotent stem cells (iPSCs). Transcriptome analysis of four biological replicates identified severe mitochondrial dysfunction and a type I interferon response as the pathways most affected by frataxin knockdown. We confirmed that, in iPSC-derived cardiomyocytes, loss of frataxin leads to mitochondrial dysfunction. The type I interferon response was activated in multiple cell types following acute frataxin knockdown and was caused, at least in part, by release of mitochondrial DNA into the cytosol, activating the cGAS-STING sensor pathway.
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Affiliation(s)
- M. Grazia Cotticelli
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Shujuan Xia
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Rachel Truitt
- Department of Medicine, Division of Translational Medicine and Human Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicolai M. Doliba
- Institute of Diabetes, Obesity, and Metabolism, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrea V. Rozo
- Institute of Diabetes, Obesity, and Metabolism, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John W. Tobias
- Department of Genetics, Penn Genomics Analysis Core, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Taehee Lee
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Justin Chen
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jill S. Napierala
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marek Napierala
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wenli Yang
- Department of Medicine, Division of Translational Medicine and Human Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert B. Wilson
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Author for correspondence ()
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Tiberi J, Segatto M, Fiorenza MT, La Rosa P. Apparent Opportunities and Hidden Pitfalls: The Conflicting Results of Restoring NRF2-Regulated Redox Metabolism in Friedreich's Ataxia Pre-Clinical Models and Clinical Trials. Biomedicines 2023; 11:biomedicines11051293. [PMID: 37238963 DOI: 10.3390/biomedicines11051293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/18/2023] [Accepted: 04/22/2023] [Indexed: 05/28/2023] Open
Abstract
Friedreich's ataxia (FRDA) is an autosomal, recessive, inherited neurodegenerative disease caused by the loss of activity of the mitochondrial protein frataxin (FXN), which primarily affects dorsal root ganglia, cerebellum, and spinal cord neurons. The genetic defect consists of the trinucleotide GAA expansion in the first intron of FXN gene, which impedes its transcription. The resulting FXN deficiency perturbs iron homeostasis and metabolism, determining mitochondrial dysfunctions and leading to reduced ATP production, increased reactive oxygen species (ROS) formation, and lipid peroxidation. These alterations are exacerbated by the defective functionality of the nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor acting as a key mediator of the cellular redox signalling and antioxidant response. Because oxidative stress represents a major pathophysiological contributor to FRDA onset and progression, a great effort has been dedicated to the attempt to restore the NRF2 signalling axis. Despite this, the beneficial effects of antioxidant therapies in clinical trials only partly reflect the promising results obtained in preclinical studies conducted in cell cultures and animal models. For these reasons, in this critical review, we overview the outcomes obtained with the administration of various antioxidant compounds and critically analyse the aspects that may have contributed to the conflicting results of preclinical and clinical studies.
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Affiliation(s)
- Jessica Tiberi
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Via dei Marsi 78, 00185 Rome, Italy
- PhD Program in Behavioral Neuroscience, Sapienza University of Rome, Via dei Marsi 78, 00185 Rome, Italy
| | - Marco Segatto
- Department of Bioscience and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy
| | - Maria Teresa Fiorenza
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Via dei Marsi 78, 00185 Rome, Italy
- European Center for Brain Research, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00179 Rome, Italy
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Via dei Marsi 78, 00185 Rome, Italy
- European Center for Brain Research, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00179 Rome, Italy
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Fil D, Conley RL, Zuberi AR, Lutz CM, Gemelli T, Napierala M, Napierala JS. Neurobehavioral deficits of mice expressing a low level of G127V mutant frataxin. Neurobiol Dis 2023; 177:105996. [PMID: 36638893 PMCID: PMC9901512 DOI: 10.1016/j.nbd.2023.105996] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/20/2022] [Accepted: 01/06/2023] [Indexed: 01/11/2023] Open
Abstract
Friedreich's ataxia (FRDA) is a neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin (FXN). Most FRDA patients are homozygous for large expansions of GAA repeats in intron 1 of FXN, while some are compound heterozygotes with an expanded GAA tract in one allele and a missense or nonsense mutation in the other. A missense mutation, changing a glycine to valine at position 130 (G130V), is prevalent among the clinical variants. We and others have demonstrated that levels of mature FXN protein in FRDA G130V samples are reduced below those detected in samples harboring homozygous repeat expansions. Little is known regarding expression and function of endogenous FXN-G130V protein due to lack of reagents and models that can distinguish the mutant FXN protein from the wild-type FXN produced from the GAA-expanded allele. We aimed to determine the effect of the G130V (murine G127V) mutation on Fxn expression and to define its multi-system impact in vivo. We used CRISPR/Cas9 to introduce the G127V missense mutation in the Fxn coding sequence and generated homozygous mice (FxnG127V/G127V). We also introduced the G127V mutation into a GAA repeat expansion FRDA mouse model (FxnGAA230/KO; KIKO) to generate a compound heterozygous strain (FxnG127V/GAA230). We performed neurobehavioral tests on cohorts of WT and Fxn mutant animals at three-month intervals for one year, and collected tissue samples to analyze molecular changes during that time. The endogenous Fxn G127V protein is detected at much lower levels in all tissues analyzed from FxnG127V/G127V mice compared to age and sex-matched WT mice without differences in Fxn transcript levels. FxnG127V/G127V mice are significantly smaller than WT counterparts, but perform similarly in most neurobehavioral tasks. RNA sequencing analysis revealed reduced expression of genes in oxidative phosphorylation and protein synthesis, underscoring the metabolic consequences in our mouse model expressing extremely low levels of Fxn. Results of these studies provide insight into the unique pathogenic mechanism of the FXN G130V mechanism and the tolerable limit of Fxn/FXN expression in vivo.
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Affiliation(s)
- Daniel Fil
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Robbie L Conley
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Aamir R Zuberi
- Technology Evaluation and Development, JAX Center for Precision Genetics, Rare Disease Translational Center, The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Cathleen M Lutz
- The Rare and Orphan Disease Center, JAX Center for Precision Genetics, Rare Disease Translational Center, The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Terry Gemelli
- Department of Neurology, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jill S Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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9
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Gérard C, Archambault AF, Bouchard C, Tremblay JP. A promising mouse model for Friedreich Ataxia progressing like human patients. Behav Brain Res 2023; 436:114107. [DOI: 10.1016/j.bbr.2022.114107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 11/27/2022]
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10
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Hackett PT, Jia X, Li L, Ward DM. Posttranslational regulation of mitochondrial frataxin and identification of compounds that increase frataxin levels in Friedreich's ataxia. J Biol Chem 2022; 298:101982. [PMID: 35472330 PMCID: PMC9127368 DOI: 10.1016/j.jbc.2022.101982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 11/18/2022] Open
Abstract
Friedreich's ataxia (FRDA) is a degenerative disease caused by a decrease in the mitochondrial protein frataxin (Fxn), which is involved in iron-sulfur cluster (ISC) synthesis. Diminutions in Fxn result in decreased ISC synthesis, increased mitochondrial iron accumulation, and impaired mitochondrial function. Here, we show that conditions that result in increased mitochondrial reactive oxygen species in yeast or mammalian cell culture give rise to increased turnover of Fxn but not of other ISC synthesis proteins. We demonstrate that the mitochondrial Lon protease is involved in Fxn degradation and that iron export through the mitochondrial metal transporter Mmt1 protects yeast Fxn from degradation. We also determined that when FRDA fibroblasts were grown in media containing elevated iron, mitochondrial reactive oxygen species increased and Fxn decreased compared to WT fibroblasts. Furthermore, we screened a library of FDA-approved compounds and identified 38 compounds that increased yeast Fxn levels, including the azole bifonazole, antiparasitic fipronil, antitumor compound dibenzoylmethane, antihypertensive 4-hydroxychalcone, and a nonspecific anion channel inhibitor 4,4-diisothiocyanostilbene-2,2-sulfonic acid. We show that top hits 4-hydroxychalcone and dibenzoylmethane increased mRNA levels of transcription factor nuclear factor erythroid 2-related factor 2 in FRDA patient-derived fibroblasts, as well as downstream antioxidant targets thioredoxin, glutathione reductase, and superoxide dismutase 2. Taken together, these findings reveal that FRDA progression may be in part due to oxidant-mediated decreases in Fxn and that some approved compounds may be effective in increasing mitochondrial Fxn in FRDA, delaying disease progression.
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Affiliation(s)
- Peter T Hackett
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Xuan Jia
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Liangtao Li
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Diane M Ward
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah, USA.
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11
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Monfort B, Want K, Gervason S, D’Autréaux B. Recent Advances in the Elucidation of Frataxin Biochemical Function Open Novel Perspectives for the Treatment of Friedreich’s Ataxia. Front Neurosci 2022; 16:838335. [PMID: 35310092 PMCID: PMC8924461 DOI: 10.3389/fnins.2022.838335] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/28/2022] [Indexed: 12/25/2022] Open
Abstract
Friedreich’s ataxia (FRDA) is the most prevalent autosomic recessive ataxia and is associated with a severe cardiac hypertrophy and less frequently diabetes. It is caused by mutations in the gene encoding frataxin (FXN), a small mitochondrial protein. The primary consequence is a defective expression of FXN, with basal protein levels decreased by 70–98%, which foremost affects the cerebellum, dorsal root ganglia, heart and liver. FXN is a mitochondrial protein involved in iron metabolism but its exact function has remained elusive and highly debated since its discovery. At the cellular level, FRDA is characterized by a general deficit in the biosynthesis of iron-sulfur (Fe-S) clusters and heme, iron accumulation and deposition in mitochondria, and sensitivity to oxidative stress. Based on these phenotypes and the proposed ability of FXN to bind iron, a role as an iron storage protein providing iron for Fe-S cluster and heme biosynthesis was initially proposed. However, this model was challenged by several other studies and it is now widely accepted that FXN functions primarily in Fe-S cluster biosynthesis, with iron accumulation, heme deficiency and oxidative stress sensitivity appearing later on as secondary defects. Nonetheless, the biochemical function of FXN in Fe-S cluster biosynthesis is still debated. Several roles have been proposed for FXN: iron chaperone, gate-keeper of detrimental Fe-S cluster biosynthesis, sulfide production stimulator and sulfur transfer accelerator. A picture is now emerging which points toward a unique function of FXN as an accelerator of a key step of sulfur transfer between two components of the Fe-S cluster biosynthetic complex. These findings should foster the development of new strategies for the treatment of FRDA. We will review here the latest discoveries on the biochemical function of frataxin and the implication for a potential therapeutic treatment of FRDA.
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12
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Kilikevicius A, Wang J, Shen X, Rigo F, Prakash TP, Napierala M, Corey DR. Difficulties translating antisense-mediated activation of Frataxin expression from cell culture to mice. RNA Biol 2021; 19:364-372. [PMID: 35289725 PMCID: PMC8928816 DOI: 10.1080/15476286.2022.2043650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/11/2022] [Indexed: 11/09/2022] Open
Abstract
Friedreich's ataxia (FA) is an inherited neurodegenerative disorder caused by decreased expression of frataxin (FXN) protein. Previous studies have shown that antisense oligonucleotides (ASOs) and single-stranded silencing RNAs can be used to increase expression of frataxin in cultured patient-derived cells. In this study, we investigate the potential for oligonucleotides to increase frataxin expression in a mouse model for FA. After confirming successful in vivo delivery of oligonucleotides using a benchmark gapmer targeting the nuclear noncoding RNA Malat1, we tested anti-FXN oligonucleotides designed to function by various mechanisms. None of these strategies yielded enhanced expression of FXN in the model mice. Our inability to translate activation of FXN expression from cell culture to mice may be due to inadequate potency of our compounds or differences in the molecular mechanisms governing FXN gene repression and activation in FA model mice.
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Affiliation(s)
- Audrius Kilikevicius
- Department of Pharmacology and Biochemistry, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Jun Wang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, Alabama, USA
| | - Xiulong Shen
- Department of Pharmacology and Biochemistry, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Frank Rigo
- Ionis Pharmaceuticals, Medicinal Chemistry and Antisense Research, Carlsbad, California, USA
| | - Thahza P. Prakash
- Ionis Pharmaceuticals, Medicinal Chemistry and Antisense Research, Carlsbad, California, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, Alabama, USA
- Department of Neurology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - David R. Corey
- Department of Pharmacology and Biochemistry, UT Southwestern Medical Center, Dallas, Texas, United States
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13
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Ocana-Santero G, Díaz-Nido J, Herranz-Martín S. Future Prospects of Gene Therapy for Friedreich's Ataxia. Int J Mol Sci 2021; 22:1815. [PMID: 33670433 PMCID: PMC7918362 DOI: 10.3390/ijms22041815] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 12/18/2022] Open
Abstract
Friedreich's ataxia is an autosomal recessive neurogenetic disease that is mainly associated with atrophy of the spinal cord and progressive neurodegeneration in the cerebellum. The disease is caused by a GAA-expansion in the first intron of the frataxin gene leading to a decreased level of frataxin protein, which results in mitochondrial dysfunction. Currently, there is no effective treatment to delay neurodegeneration in Friedreich's ataxia. A plausible therapeutic approach is gene therapy. Indeed, Friedreich's ataxia mouse models have been treated with viral vectors en-coding for either FXN or neurotrophins, such as brain-derived neurotrophic factor showing promising results. Thus, gene therapy is increasingly consolidating as one of the most promising therapies. However, several hurdles have to be overcome, including immunotoxicity and pheno-toxicity. We review the state of the art of gene therapy in Friedreich's ataxia, addressing the main challenges and the most feasible solutions for them.
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Affiliation(s)
- Gabriel Ocana-Santero
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain; (G.O.-S.); (J.D.-N.)
- Department of Physiology, Anatomy and Genetics, Sherrington Building, Parks Road, University of Oxford, Oxford OX1 3PT, UK
| | - Javier Díaz-Nido
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain; (G.O.-S.); (J.D.-N.)
| | - Saúl Herranz-Martín
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain; (G.O.-S.); (J.D.-N.)
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14
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Zhao X, Kumari D, Miller CJ, Kim GY, Hayward B, Vitalo AG, Pinto RM, Usdin K. Modifiers of Somatic Repeat Instability in Mouse Models of Friedreich Ataxia and the Fragile X-Related Disorders: Implications for the Mechanism of Somatic Expansion in Huntington's Disease. J Huntingtons Dis 2021; 10:149-163. [PMID: 33579860 PMCID: PMC7990428 DOI: 10.3233/jhd-200423] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Huntington's disease (HD) is one of a large group of human disorders that are caused by expanded DNA repeats. These repeat expansion disorders can have repeat units of different size and sequence that can be located in any part of the gene and, while the pathological consequences of the expansion can differ widely, there is evidence to suggest that the underlying mutational mechanism may be similar. In the case of HD, the expanded repeat unit is a CAG trinucleotide located in exon 1 of the huntingtin (HTT) gene, resulting in an expanded polyglutamine tract in the huntingtin protein. Expansion results in neuronal cell death, particularly in the striatum. Emerging evidence suggests that somatic CAG expansion, specifically expansion occurring in the brain during the lifetime of an individual, contributes to an earlier disease onset and increased severity. In this review we will discuss mouse models of two non-CAG repeat expansion diseases, specifically the Fragile X-related disorders (FXDs) and Friedreich ataxia (FRDA). We will compare and contrast these models with mouse and patient-derived cell models of various other repeat expansion disorders and the relevance of these findings for somatic expansion in HD. We will also describe additional genetic factors and pathways that modify somatic expansion in the FXD mouse model for which no comparable data yet exists in HD mice or humans. These additional factors expand the potential druggable space for diseases like HD where somatic expansion is a significant contributor to disease impact.
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Affiliation(s)
- Xiaonan Zhao
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Daman Kumari
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Carson J Miller
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Geum-Yi Kim
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bruce Hayward
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Antonia G Vitalo
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Ricardo Mouro Pinto
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Karen Usdin
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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15
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La Rosa P, Petrillo S, Fiorenza MT, Bertini ES, Piemonte F. Ferroptosis in Friedreich's Ataxia: A Metal-Induced Neurodegenerative Disease. Biomolecules 2020; 10:biom10111551. [PMID: 33202971 PMCID: PMC7696618 DOI: 10.3390/biom10111551] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 02/07/2023] Open
Abstract
Ferroptosis is an iron-dependent form of regulated cell death, arising from the accumulation of lipid-based reactive oxygen species when glutathione-dependent repair systems are compromised. Lipid peroxidation, mitochondrial impairment and iron dyshomeostasis are the hallmark of ferroptosis, which is emerging as a crucial player in neurodegeneration. This review provides an analysis of the most recent advances in ferroptosis, with a special focus on Friedreich's Ataxia (FA), the most common autosomal recessive neurodegenerative disease, caused by reduced levels of frataxin, a mitochondrial protein involved in iron-sulfur cluster synthesis and antioxidant defenses. The hypothesis is that the iron-induced oxidative damage accumulates over time in FA, lowering the ferroptosis threshold and leading to neuronal cell death and, at last, to cardiac failure. The use of anti-ferroptosis drugs combined with treatments able to activate the antioxidant response will be of paramount importance in FA therapy, such as in many other neurodegenerative diseases triggered by oxidative stress.
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Affiliation(s)
- Piergiorgio La Rosa
- Department of Psychology, Division of Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (P.L.R.); (M.T.F.)
| | - Sara Petrillo
- Unit of Muscular and Neurodegenerative Diseases, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy; (S.P.); (E.S.B.)
| | - Maria Teresa Fiorenza
- Department of Psychology, Division of Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (P.L.R.); (M.T.F.)
| | - Enrico Silvio Bertini
- Unit of Muscular and Neurodegenerative Diseases, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy; (S.P.); (E.S.B.)
| | - Fiorella Piemonte
- Unit of Muscular and Neurodegenerative Diseases, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy; (S.P.); (E.S.B.)
- Correspondence: ; Tel.: +39-06-6859-2102
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16
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The Nrf2 induction prevents ferroptosis in Friedreich's Ataxia. Redox Biol 2020; 38:101791. [PMID: 33197769 PMCID: PMC7677700 DOI: 10.1016/j.redox.2020.101791] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/14/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022] Open
Abstract
Ferroptosis is an iron-dependent cell death caused by impaired glutathione metabolism, lipid peroxidation and mitochondrial failure. Emerging evidences report a role for ferroptosis in Friedreich's Ataxia (FRDA), a neurodegenerative disease caused by the decreased expression of the mitochondrial protein frataxin. Nrf2 signalling is implicated in many molecular aspects of ferroptosis, by upstream regulating glutathione homeostasis, mitochondrial function and lipid metabolism. As Nrf2 is down-regulated in FRDA, targeting Nrf2-mediated ferroptosis in FRDA may be an attractive option to counteract neurodegeneration in such disease, thus paving the way to new therapeutic opportunities. In this study, we evaluated ferroptosis hallmarks in frataxin-silenced mouse myoblasts, in hearts of a frataxin Knockin/Knockout (KIKO) mouse model, in skin fibroblasts and blood of patients, particularly focusing on ferroptosis-driven gene expression, mitochondrial impairment and lipid peroxidation. The efficacy of Nrf2 inducers to neutralize ferroptosis has been also evaluated.
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17
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Fil D, Chacko BK, Conley R, Ouyang X, Zhang J, Darley-Usmar VM, Zuberi AR, Lutz CM, Napierala M, Napierala JS. Mitochondrial damage and senescence phenotype of cells derived from a novel frataxin G127V point mutation mouse model of Friedreich's ataxia. Dis Model Mech 2020; 13:dmm045229. [PMID: 32586831 PMCID: PMC7406325 DOI: 10.1242/dmm.045229] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/16/2020] [Indexed: 12/11/2022] Open
Abstract
Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin (FXN). Most FRDA patients are homozygous for large expansions of GAA repeat sequences in intron 1 of FXN, whereas a fraction of patients are compound heterozygotes, with a missense or nonsense mutation in one FXN allele and expanded GAAs in the other. A prevalent missense mutation among FRDA patients changes a glycine at position 130 to valine (G130V). Herein, we report generation of the first mouse model harboring an Fxn point mutation. Changing the evolutionarily conserved glycine 127 in mouse Fxn to valine results in a failure-to-thrive phenotype in homozygous animals and a substantially reduced number of offspring. Like G130V in FRDA, the G127V mutation results in a dramatic decrease of Fxn protein without affecting transcript synthesis or splicing. FxnG127V mouse embryonic fibroblasts exhibit significantly reduced proliferation and increased cell senescence. These defects are evident in early passage cells and are exacerbated at later passages. Furthermore, increased frequency of mitochondrial DNA lesions and fragmentation are accompanied by marked amplification of mitochondrial DNA in FxnG127V cells. Bioenergetics analyses demonstrate higher sensitivity and reduced cellular respiration of FxnG127V cells upon alteration of fatty acid availability. Importantly, substitution of FxnWT with FxnG127V is compatible with life, and cellular proliferation defects can be rescued by mitigation of oxidative stress via hypoxia or induction of the NRF2 pathway. We propose FxnG127V cells as a simple and robust model for testing therapeutic approaches for FRDA.
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Affiliation(s)
- Daniel Fil
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - Balu K Chacko
- Department of Pathology, University of Alabama at Birmingham, 901 19th Street South, Birmingham, AL 35294, USA
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Mitochondrial Medicine Laboratory, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Robbie Conley
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - Xiaosen Ouyang
- Department of Pathology, University of Alabama at Birmingham, 901 19th Street South, Birmingham, AL 35294, USA
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Mitochondrial Medicine Laboratory, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Veteran Affairs Medical Center, Birmingham, AL 35294, USA
| | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, 901 19th Street South, Birmingham, AL 35294, USA
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Mitochondrial Medicine Laboratory, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Veteran Affairs Medical Center, Birmingham, AL 35294, USA
| | - Victor M Darley-Usmar
- Department of Pathology, University of Alabama at Birmingham, 901 19th Street South, Birmingham, AL 35294, USA
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Mitochondrial Medicine Laboratory, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Aamir R Zuberi
- The Rare and Orphan Disease Center, JAX Center for Precision Genetics, 600 Main Street, Bar Harbor, ME 04609, USA
| | - Cathleen M Lutz
- The Rare and Orphan Disease Center, JAX Center for Precision Genetics, 600 Main Street, Bar Harbor, ME 04609, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - Jill S Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
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18
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Cerebellar Astrocytes: Much More Than Passive Bystanders In Ataxia Pathophysiology. J Clin Med 2020; 9:jcm9030757. [PMID: 32168822 PMCID: PMC7141261 DOI: 10.3390/jcm9030757] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/22/2022] Open
Abstract
Ataxia is a neurodegenerative syndrome, which can emerge as a major element of a disease or represent a symptom of more complex multisystemic disorders. It comprises several forms with a highly variegated etiology, mainly united by motor, balance, and speech impairments and, at the tissue level, by cerebellar atrophy and Purkinje cells degeneration. For this reason, the contribution of astrocytes to this disease has been largely overlooked in the past. Nevertheless, in the last few decades, growing evidences are pointing to cerebellar astrocytes as crucial players not only in the progression but also in the onset of distinct forms of ataxia. Although the current knowledge on this topic is very fragmentary and ataxia type-specific, the present review will attempt to provide a comprehensive view of astrocytes’ involvement across the distinct forms of this pathology. Here, it will be highlighted how, through consecutive stage-specific mechanisms, astrocytes can lead to non-cell autonomous neurodegeneration and, consequently, to the behavioral impairments typical of this disease. In light of that, treating astrocytes to heal neurons will be discussed as a potential complementary therapeutic approach for ataxic patients, a crucial point provided the absence of conclusive treatments for this disease.
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19
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Igoillo-Esteve M, Oliveira AF, Cosentino C, Fantuzzi F, Demarez C, Toivonen S, Hu A, Chintawar S, Lopes M, Pachera N, Cai Y, Abdulkarim B, Rai M, Marselli L, Marchetti P, Tariq M, Jonas JC, Boscolo M, Pandolfo M, Eizirik DL, Cnop M. Exenatide induces frataxin expression and improves mitochondrial function in Friedreich ataxia. JCI Insight 2020; 5:134221. [PMID: 31877117 PMCID: PMC7098728 DOI: 10.1172/jci.insight.134221] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/18/2019] [Indexed: 12/26/2022] Open
Abstract
Friedreich ataxia is an autosomal recessive neurodegenerative disease associated with a high diabetes prevalence. No treatment is available to prevent or delay disease progression. Friedreich ataxia is caused by intronic GAA trinucleotide repeat expansions in the frataxin-encoding FXN gene that reduce frataxin expression, impair iron-sulfur cluster biogenesis, cause oxidative stress, and result in mitochondrial dysfunction and apoptosis. Here we examined the metabolic, neuroprotective, and frataxin-inducing effects of glucagon-like peptide-1 (GLP-1) analogs in in vivo and in vitro models and in patients with Friedreich ataxia. The GLP-1 analog exenatide improved glucose homeostasis of frataxin-deficient mice through enhanced insulin content and secretion in pancreatic β cells. Exenatide induced frataxin and iron-sulfur cluster-containing proteins in β cells and brain and was protective to sensory neurons in dorsal root ganglia. GLP-1 analogs also induced frataxin expression, reduced oxidative stress, and improved mitochondrial function in Friedreich ataxia patients' induced pluripotent stem cell-derived β cells and sensory neurons. The frataxin-inducing effect of exenatide was confirmed in a pilot trial in Friedreich ataxia patients, showing modest frataxin induction in platelets over a 5-week treatment course. Taken together, GLP-1 analogs improve mitochondrial function in frataxin-deficient cells and induce frataxin expression. Our findings identify incretin receptors as a therapeutic target in Friedreich ataxia.
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Affiliation(s)
| | | | | | - Federica Fantuzzi
- ULB Center for Diabetes Research and
- Endocrinology and Metabolism, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | | | | | - Amélie Hu
- Laboratory of Experimental Neurology, Université Libre de Bruxelles, Brussels, Belgium
| | - Satyan Chintawar
- Laboratory of Experimental Neurology, Université Libre de Bruxelles, Brussels, Belgium
| | | | | | - Ying Cai
- ULB Center for Diabetes Research and
| | | | - Myriam Rai
- Laboratory of Experimental Neurology, Université Libre de Bruxelles, Brussels, Belgium
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Mohammad Tariq
- Pole of Endocrinology, Diabetes and Nutrition, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Jean-Christophe Jonas
- Pole of Endocrinology, Diabetes and Nutrition, Institute of Experimental and Clinical Research, Université Catholique de Louvain, Brussels, Belgium
| | - Marina Boscolo
- Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Massimo Pandolfo
- Laboratory of Experimental Neurology, Université Libre de Bruxelles, Brussels, Belgium
| | - Décio L. Eizirik
- ULB Center for Diabetes Research and
- Indiana Biosciences Research Institute, Indianapolis, Indiana, USA
| | - Miriam Cnop
- ULB Center for Diabetes Research and
- Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
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20
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Stepanova A, Magrané J. Mitochondrial dysfunction in neurons in Friedreich's ataxia. Mol Cell Neurosci 2020; 102:103419. [PMID: 31770591 DOI: 10.1016/j.mcn.2019.103419] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 11/05/2019] [Accepted: 11/08/2019] [Indexed: 12/20/2022] Open
Abstract
Friedreich's ataxia is a multisystemic genetic disorder within the family of mitochondrial diseases that is characterized by reduced levels of the essential mitochondrial protein frataxin. Based on clinical evidence, the peripheral nervous system is affected early, neuronal dysfunction progresses towards the central nervous system, and other organs (such as heart and pancreas) are affected later. However, little attention has been given to the specific aspects of mitochondria function altered by frataxin depletion in the nervous system. For years, commonly accepted views on mitochondria dysfunction in Friedreich's ataxia stemmed from studies using non-neuronal systems and may not apply to neurons, which have their own bioenergetic needs and present a unique, extensive neurite network. Moreover, the basis of the selective neuronal vulnerability, which primarily affects large sensory neurons in the dorsal root ganglia, large principal neurons in the dentate nuclei of the cerebellum, and pyramidal neurons in the cerebral cortex, remains elusive. In order to identify potential misbeliefs in the field and highlight controversies, we reviewed current knowledge on frataxin expression in different tissues, discussed the molecular function of frataxin, and the consequences of its deficiency for mitochondria structural and functional properties, with a focus on the nervous system.
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Affiliation(s)
- Anna Stepanova
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States of America.
| | - Jordi Magrané
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, United States of America.
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21
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Griso O, Puccio H. Primary Cultures of Pure Embryonic Dorsal Root Ganglia Sensory Neurons as a New Cellular Model for Friedreich's Ataxia. Methods Mol Biol 2020; 2056:241-253. [PMID: 31586352 DOI: 10.1007/978-1-4939-9784-8_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Peripheral neuropathies can have various origins, from genetic to acquired causes, and affect altogether a large group of people in the world. Current available therapies aim at helping the disease symptoms but not to correct or stop the development of the disease. Primary neuronal cultures represent an essential tool in the study of events related to peripheral neuropathies as they allow to isolate the affected cell types, often originating in complex tissues in which they account for only a few percentage of cells. They provide a powerful system to identifying or testing compounds with potential therapeutic effect in the treatment of those diseases. Friedreich's ataxia is an autosomal recessive neurodegenerative disorder, which is characterized by a progressive spinocerebellar and sensory ataxia. Proprioceptive neurons of the dorsal root ganglia (DRG) are the primary affected cells. The disease is triggered by a mutation in the gene FXN which leads to a reduction of the frataxin protein. In order to study the neurophysiopathology of the disease at the cellular and molecular levels, we have established a model of primary cultures of DRG sensory neurons in which we induce the loss of the frataxin protein. With such a model we can alleviate the issues related to the complexity of DRG tissues and low amount of sensory neuron material in adult mouse. Hereby, we provide a protocol of detailed and optimized methods to obtain high yield of healthy mouse DRG sensory neuron in culture.
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Affiliation(s)
- Olivier Griso
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
- INSERM, U1258, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Hélène Puccio
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.
- INSERM, U1258, Illkirch, France.
- CNRS, UMR7104, Illkirch, France.
- Université de Strasbourg, Strasbourg, France.
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22
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McMackin MZ, Durbin-Johnson B, Napierala M, Napierala JS, Ruiz L, Napoli E, Perlman S, Giulivi C, Cortopassi GA. Potential biomarker identification for Friedreich's ataxia using overlapping gene expression patterns in patient cells and mouse dorsal root ganglion. PLoS One 2019; 14:e0223209. [PMID: 31665133 PMCID: PMC6821053 DOI: 10.1371/journal.pone.0223209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/15/2019] [Indexed: 12/22/2022] Open
Abstract
Friedreich's ataxia (FA) is a neurodegenerative disease with no approved therapy that is the result of frataxin deficiency. The identification of human FA blood biomarkers related to disease severity and neuro-pathomechanism could support clinical trials of drug efficacy. To try to identify human biomarkers of neuro-pathomechanistic relevance, we compared the overlapping gene expression changes of primary blood and skin cells of FA patients with changes in the Dorsal Root Ganglion (DRG) of the KIKO FA mouse model. As DRG is the primary site of neurodegeneration in FA, our goal was to identify which changes in blood and skin of FA patients provide a 'window' into the FA neuropathomechanism inside the nervous system. In addition, gene expression in frataxin-deficient neuroglial cells and FA mouse hearts were compared for a total of 5 data sets. The overlap of these changes strongly supports mitochondrial changes, apoptosis and alterations of selenium metabolism. Consistent biomarkers were observed, including three genes of mitochondrial stress (MTIF2, ENO2), apoptosis (DDIT3/CHOP), oxidative stress (PREX1), and selenometabolism (SEPW1). These results prompted our investigation of the GPX1 activity as a marker of selenium and oxidative stress, in which we observed a significant change in FA patients. We believe these lead biomarkers that could be assayed in FA patient blood as indicators of disease severity and progression, and also support the involvement of mitochondria, apoptosis and selenium in the neurodegenerative process.
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Affiliation(s)
- Marissa Z. McMackin
- Department of Molecular Biosciences, University of California, Davis, Davis, California, United States of America
| | - Blythe Durbin-Johnson
- Bioinformatics, University of California, Davis, Davis, California, United States of America
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Jill S. Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Luis Ruiz
- Department of Molecular Biosciences, University of California, Davis, Davis, California, United States of America
| | - Eleonora Napoli
- Department of Molecular Biosciences, University of California, Davis, Davis, California, United States of America
| | - Susan Perlman
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Cecilia Giulivi
- Department of Molecular Biosciences, University of California, Davis, Davis, California, United States of America
| | - Gino A. Cortopassi
- Department of Molecular Biosciences, University of California, Davis, Davis, California, United States of America
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23
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La Rosa P, Russo M, D'Amico J, Petrillo S, Aquilano K, Lettieri-Barbato D, Turchi R, Bertini ES, Piemonte F. Nrf2 Induction Re-establishes a Proper Neuronal Differentiation Program in Friedreich's Ataxia Neural Stem Cells. Front Cell Neurosci 2019; 13:356. [PMID: 31417369 PMCID: PMC6685360 DOI: 10.3389/fncel.2019.00356] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022] Open
Abstract
Frataxin deficiency is the pathogenic cause of Friedreich’s Ataxia, an autosomal recessive disease characterized by the increase of oxidative stress and production of free radicals in the cell. Although the onset of the pathology occurs in the second decade of life, cognitive differences and defects in brain structure and functional activation are observed in patients, suggesting developmental defects to take place during fetal neurogenesis. Here, we describe impairments in proliferation, stemness potential and differentiation in neural stem cells (NSCs) isolated from the embryonic cortex of the Frataxin Knockin/Knockout mouse, a disease animal model whose slow-evolving phenotype makes it suitable to study pre-symptomatic defects that may manifest before the clinical onset. We demonstrate that enhancing the expression and activity of the antioxidant response master regulator Nrf2 ameliorates the phenotypic defects observed in NSCs, re-establishing a proper differentiation program.
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Affiliation(s)
- Piergiorgio La Rosa
- Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Marta Russo
- Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Jessica D'Amico
- Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Sara Petrillo
- Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Katia Aquilano
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Daniele Lettieri-Barbato
- Department of Biology, University of Rome Tor Vergata, Rome, Italy.,IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Riccardo Turchi
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Enrico S Bertini
- Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Fiorella Piemonte
- Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
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24
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Clay A, Hearle P, Schadt K, Lynch DR. New developments in pharmacotherapy for Friedreich ataxia. Expert Opin Pharmacother 2019; 20:1855-1867. [PMID: 31311349 DOI: 10.1080/14656566.2019.1639671] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Friedreich ataxia (FRDA), a rare disease caused by the deficiency of the mitochondrial matrix protein frataxin, affects roughly 1 in 50,000 individuals worldwide. Current and emerging therapies focus on reversing the deleterious effects of such deficiency including mitochondrial augmentation and increasing frataxin levels, providing the possibility of treatment options for this physiologically complex, multisystem disorder. Areas covered: In this review article, the authors discuss the current and prior in vivo and in vitro research studies related to the treatment of FRDA, with a particular interest in future implications of each therapy. Expert opinion: Since the discovery of FXN in 1996, multiple clinical trials have occurred or are currently occurring; at a rapid pace for a rare disease. These trials have been directed at the augmentation of mitochondrial function and/or alleviation of symptoms and are not regarded as potential cures in FRDA. Either a combination of therapies or a drug that replaces or increases the pathologically low levels of frataxin better represent potential cures in FRDA.
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Affiliation(s)
- Alexandra Clay
- Division of Neurology, Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Patrick Hearle
- Division of Neurology, Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Kim Schadt
- Division of Neurology, Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - David R Lynch
- Division of Neurology, Children's Hospital of Philadelphia , Philadelphia , PA , USA
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25
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Wong AOT, Wong G, Shen M, Chow MZY, Tse WW, Gurung B, Mak SY, Lieu DK, Costa KD, Chan CW, Martelli A, Nabhan JF, Li RA. Correlation between frataxin expression and contractility revealed by in vitro Friedreich's ataxia cardiac tissue models engineered from human pluripotent stem cells. Stem Cell Res Ther 2019; 10:203. [PMID: 31286988 PMCID: PMC6615274 DOI: 10.1186/s13287-019-1305-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/30/2019] [Accepted: 06/17/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Friedreich's ataxia (FRDA) is an autosomal recessive disease caused by a non-coding mutation in the first intron of the frataxin (FXN) gene that suppresses its expression. Compensatory hypertrophic cardiomyopathy, dilated cardiomyopathy, and conduction system abnormalities in FRDA lead to cardiomyocyte (CM) death and fibrosis, consequently resulting in heart failure and arrhythmias. Murine models have been developed to study disease pathology in the past two decades; however, differences between human and mouse physiology and metabolism have limited the relevance of animal studies in cardiac disease conditions. To bridge this gap, we aimed to generate species-specific, functional in vitro experimental models of FRDA using 2-dimensional (2D) and 3-dimensional (3D) engineered cardiac tissues from FXN-deficient human pluripotent stem cell-derived ventricular cardiomyocytes (hPSC-hvCMs) and to compare their contractile and electrophysiological properties with healthy tissue constructs. METHODS Healthy control and FRDA patient-specific hPSC-hvCMs were derived by directed differentiation using a small molecule-based protocol reported previously. We engineered the hvCMs into our established human ventricular cardiac tissue strip (hvCTS) and human ventricular cardiac anisotropic sheet (hvCAS) models, and functional assays were performed on days 7-17 post-tissue fabrication to assess the electrophysiology and contractility of FRDA patient-derived and FXN-knockdown engineered tissues, in comparison with healthy controls. To further validate the disease model, forced expression of FXN was induced in FXN-deficient tissues to test if disease phenotypes could be rescued. RESULTS Here, we report for the first time the generation of human engineered tissue models of FRDA cardiomyopathy from hPSCs: FXN-deficient hvCTS displayed attenuated developed forces (by 70-80%) compared to healthy controls. High-resolution optical mapping of hvCAS with reduced FXN expression also revealed electrophysiological defects consistent with clinical observations, including action potential duration prolongation and maximum capture frequency reduction. Interestingly, a clear positive correlation between FXN expression and contractility was observed (ρ > 0.9), and restoration of FXN protein levels by lentiviral transduction rescued contractility defects in FXN-deficient hvCTS. CONCLUSIONS We conclude that human-based in vitro cardiac tissue models of FRDA provide a translational, disease-relevant biomimetic platform for the evaluation of novel therapeutics and to provide insight into FRDA disease progression.
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Affiliation(s)
| | - Gabriel Wong
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
| | - Michael Shen
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
| | | | - Wan Wai Tse
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
| | - Bimal Gurung
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
| | - Suet Yee Mak
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
| | | | | | - Camie W. Chan
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
| | - Alain Martelli
- Current address: Astellas Innovation Management Astellas Pharma, 1030 Massachusetts Avenue, Cambridge, MA 02138 USA
| | - Joseph F. Nabhan
- Current address: Astellas Innovation Management Astellas Pharma, 1030 Massachusetts Avenue, Cambridge, MA 02138 USA
| | - Ronald A. Li
- Novoheart, Vancouver, British Columbia V6C 2V6 Canada
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26
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Ast T, Meisel JD, Patra S, Wang H, Grange RMH, Kim SH, Calvo SE, Orefice LL, Nagashima F, Ichinose F, Zapol WM, Ruvkun G, Barondeau DP, Mootha VK. Hypoxia Rescues Frataxin Loss by Restoring Iron Sulfur Cluster Biogenesis. Cell 2019; 177:1507-1521.e16. [PMID: 31031004 PMCID: PMC6911770 DOI: 10.1016/j.cell.2019.03.045] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 02/11/2019] [Accepted: 03/22/2019] [Indexed: 12/16/2022]
Abstract
Friedreich's ataxia (FRDA) is a devastating, multisystemic disorder caused by recessive mutations in the mitochondrial protein frataxin (FXN). FXN participates in the biosynthesis of Fe-S clusters and is considered to be essential for viability. Here we report that when grown in 1% ambient O2, FXN null yeast, human cells, and nematodes are fully viable. In human cells, hypoxia restores steady-state levels of Fe-S clusters and normalizes ATF4, NRF2, and IRP2 signaling events associated with FRDA. Cellular studies and in vitro reconstitution indicate that hypoxia acts through HIF-independent mechanisms that increase bioavailable iron as well as directly activate Fe-S synthesis. In a mouse model of FRDA, breathing 11% O2 attenuates the progression of ataxia, whereas breathing 55% O2 hastens it. Our work identifies oxygen as a key environmental variable in the pathogenesis associated with FXN depletion, with important mechanistic and therapeutic implications.
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Affiliation(s)
- Tslil Ast
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Joshua D Meisel
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Shachin Patra
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA
| | - Hong Wang
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Robert M H Grange
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Sharon H Kim
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Sarah E Calvo
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Lauren L Orefice
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Fumiaki Nagashima
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Fumito Ichinose
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Warren M Zapol
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - David P Barondeau
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA
| | - Vamsi K Mootha
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA.
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27
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Cotticelli MG, Xia S, Lin D, Lee T, Terrab L, Wipf P, Huryn DM, Wilson RB. Ferroptosis as a Novel Therapeutic Target for Friedreich's Ataxia. J Pharmacol Exp Ther 2019; 369:47-54. [PMID: 30635474 DOI: 10.1124/jpet.118.252759] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 01/04/2019] [Indexed: 12/17/2023] Open
Abstract
Friedreich ataxia (FRDA) is a progressive neuro- and cardio-degenerative disorder characterized by ataxia, sensory loss, and hypertrophic cardiomyopathy. In most cases, the disorder is caused by GAA repeat expansions in the first introns of both alleles of the FXN gene, resulting in decreased expression of the encoded protein, frataxin. Frataxin localizes to the mitochondrial matrix and is required for iron-sulfur-cluster biosynthesis. Decreased expression of frataxin is associated with mitochondrial dysfunction, mitochondrial iron accumulation, and increased oxidative stress. Ferropotosis is a recently identified pathway of regulated, iron-dependent cell death, which is biochemically distinct from apoptosis. We evaluated whether there is evidence for ferroptotic pathway activation in cellular models of FRDA. We found that primary patient-derived fibroblasts, murine fibroblasts with FRDA-associated mutations, and murine fibroblasts in which a repeat expansion had been introduced (knockin/knockout) were more sensitive than normal control cells to erastin, a known ferroptosis inducer. We also found that the ferroptosis inhibitors ethyl 3-(benzylamino)-4-(cyclohexylamino)benzoate (SRS11-92) and ethyl 3-amino-4-(cyclohexylamino)benzoate, used at 500 nM, were efficacious in protecting human and mouse cellular models of FRDA treated with ferric ammonium citrate (FAC) and an inhibitor of glutathione synthesis [L-buthionine (S,R)-sulfoximine (BSO)], whereas caspase-3 inhibitors failed to show significant biologic activity. Cells treated with FAC and BSO consistently showed decreased glutathione-dependent peroxidase activity and increased lipid peroxidation, both hallmarks of ferroptosis. Finally, the ferroptosis inhibitor SRS11-92 decreased the cell death associated with frataxin knockdown in healthy human fibroblasts. Taken together, these data suggest that ferroptosis inhibitors may have therapeutic potential in FRDA.
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Affiliation(s)
- M Grazia Cotticelli
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Shujuan Xia
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Daniel Lin
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Taehee Lee
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Leila Terrab
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Peter Wipf
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Donna M Huryn
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Robert B Wilson
- Department of Pathology and Laboratory Medicine, Children's Hospital Philadelphia, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); The Penn Medicine/CHOP Center of Excellence for Friedreich's Ataxia Research, Philadelphia, Pennsylvania (M.G.C., S.X., D.L., T.L., R.B.W.); Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (L.T., P.W.); Department of Chemistry (D.M.H.), and Perelman School of Medicine (R.B.W.), University of Pennsylvania, Philadelphia, Pennsylvania
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28
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Schreiber AM, Misiorek JO, Napierala JS, Napierala M. Progress in understanding Friedreich's ataxia using human induced pluripotent stem cells. Expert Opin Orphan Drugs 2019; 7:81-90. [PMID: 30828501 DOI: 10.1080/21678707.2019.1562334] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Introduction Friedreich's ataxia (FRDA) is an autosomal recessive multisystem disease mainly affecting the peripheral and central nervous systems, and heart. FRDA is caused by a GAA repeat expansion in the first intron of the frataxin (FXN) gene, that leads to reduced expression of FXN mRNA and frataxin protein. Neuronal and cardiac cells are primary targets of frataxin deficiency and generating models via differentiation of induced pluripotent stem cells (iPSCs) into these cell types is essential for progress towards developing therapies for FRDA. Areas covered This review is focused on modeling FRDA using human iPSCs and various iPSC-differentiated cell types. We emphasized the importance of patient and corrected isogenic cell line pairs to minimize effects caused by biological variability between individuals. Expert opinion The versatility of iPSC-derived cellular models of FRDA is advantageous for developing new therapeutic strategies, and rigorous testing in such models will be critical for approval of the first treatment for FRDA. Creating a well-characterized and diverse set of iPSC lines, including appropriate isogenic controls, will facilitate achieving this goal. Also, improvement of differentiation protocols, especially towards proprioceptive sensory neurons and organoid generation, is necessary to utilize the full potential of iPSC technology in the drug discovery process.
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Affiliation(s)
- Anna M Schreiber
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Julia O Misiorek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Jill S Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham AL, United States
| | - Marek Napierala
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.,Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham AL, United States
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29
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Abstract
Friedreich's ataxia (FRDA) is a degenerative disease that affects both the central and the peripheral nervous systems and non-neural tissues including, mainly, heart, and endocrine pancreas. It is an autosomal recessive disease caused by a GAA triplet-repeat localized within an Alu sequence element in intron 1 of frataxin (FXN) gene, which encodes a mitochondrial protein FXN. This protein is essential for mitochondrial function by the involvement of iron-sulfur cluster biogenesis. The effects of its deficiency also include disruption of cellular, particularly mitochondrial, iron homeostasis, i.e., relatively more iron accumulated in mitochondria and less iron presented in cytosol. Though iron toxicity is commonly thought to be mediated via Fenton reaction, oxidative stress seems not to be the main problem to result in detrimental effects on cell survival, particularly neuron survival. Therefore, the basic research on FXN function is urgently demanded to understand the disease. This chapter focuses on the outcome of FXN expression, regulation, and function in cellular or animal models of FRDA and on iron pathophysiology in the affected tissues. Finally, therapeutic strategies based on the control of iron toxicity and iron cellular redistribution are considered. The combination of multiple therapeutic targets including iron, oxidative stress, mitochondrial function, and FXN regulation is also proposed.
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Affiliation(s)
- Kuanyu Li
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, 210093, People's Republic of China.
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30
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Al-Mahdawi S, Ging H, Bayot A, Cavalcanti F, La Cognata V, Cavallaro S, Giunti P, Pook MA. Large Interruptions of GAA Repeat Expansion Mutations in Friedreich Ataxia Are Very Rare. Front Cell Neurosci 2018; 12:443. [PMID: 30519163 PMCID: PMC6258883 DOI: 10.3389/fncel.2018.00443] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/05/2018] [Indexed: 12/19/2022] Open
Abstract
Friedreich ataxia is a multi-system autosomal recessive inherited disorder primarily caused by homozygous GAA repeat expansion mutations within intron 1 of the frataxin gene. The resulting deficiency of frataxin protein leads to progressive mitochondrial dysfunction, oxidative stress, and cell death, with the main affected sites being the large sensory neurons of the dorsal root ganglia and the dentate nucleus of the cerebellum. The GAA repeat expansions may be pure (GAA)n in sequence or may be interrupted with regions of non-GAA sequence. To our knowledge, there has been no large-scale study of FRDA patient DNA samples to determine the frequency of large interruptions in GAA repeat expansions. Therefore, we have investigated a panel of 245 Friedreich ataxia patient and carrier DNA samples using GAA repeat PCR amplification and MboII restriction enzyme digestion. We demonstrate that the vast majority (97.8%) of Friedreich ataxia GAA repeat expansion samples do not contain significant sequence changes that would result in abnormal MboII digestion profiles, indicating that they are primarily pure GAA repeats. These results show for the first time that large interruptions in the GAA repeats are very rare.
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Affiliation(s)
- Sahar Al-Mahdawi
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom.,Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, United Kingdom
| | - Heather Ging
- Ataxia Centre, Department of Molecular Neuroscience, Institute of Neurology, University College London, London, United Kingdom
| | - Aurelien Bayot
- Ataxia Centre, Department of Molecular Neuroscience, Institute of Neurology, University College London, London, United Kingdom
| | | | | | | | - Paola Giunti
- Ataxia Centre, Department of Molecular Neuroscience, Institute of Neurology, University College London, London, United Kingdom
| | - Mark A Pook
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom.,Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, United Kingdom
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31
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Piguet F, de Montigny C, Vaucamps N, Reutenauer L, Eisenmann A, Puccio H. Rapid and Complete Reversal of Sensory Ataxia by Gene Therapy in a Novel Model of Friedreich Ataxia. Mol Ther 2018; 26:1940-1952. [PMID: 29853274 PMCID: PMC6094869 DOI: 10.1016/j.ymthe.2018.05.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/03/2018] [Accepted: 05/05/2018] [Indexed: 01/15/2023] Open
Abstract
Friedreich ataxia (FA) is a rare mitochondrial disease characterized by sensory and spinocerebellar ataxia, hypertrophic cardiomyopathy, and diabetes, for which there is no treatment. FA is caused by reduced levels of frataxin (FXN), an essential mitochondrial protein involved in the biosynthesis of iron-sulfur (Fe-S) clusters. Despite significant progress in recent years, to date, there are no good models to explore and test therapeutic approaches to stop or reverse the ganglionopathy and the sensory neuropathy associated to frataxin deficiency. Here, we report a new conditional mouse model with complete frataxin deletion in parvalbumin-positive cells that recapitulate the sensory ataxia and neuropathy associated to FA, albeit with a more rapid and severe course. Interestingly, although fully dysfunctional, proprioceptive neurons can survive for many weeks without frataxin. Furthermore, we demonstrate that post-symptomatic delivery of frataxin-expressing AAV allows for rapid and complete rescue of the sensory neuropathy associated with frataxin deficiency, thus establishing the pre-clinical proof of concept for the potential of gene therapy in treating FA neuropathy.
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Affiliation(s)
- Françoise Piguet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Charline de Montigny
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Nadège Vaucamps
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Laurence Reutenauer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Aurélie Eisenmann
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Hélène Puccio
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France.
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Kumari R, Kumar D, Brahmachari SK, Srivastava AK, Faruq M, Mukerji M. Paradigm for disease deconvolution in rare neurodegenerative disorders in Indian population: insights from studies in cerebellar ataxias. J Genet 2018. [DOI: 10.1007/s12041-018-0948-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Lin H, Magrane J, Clark EM, Halawani SM, Warren N, Rattelle A, Lynch DR. Early VGLUT1-specific parallel fiber synaptic deficits and dysregulated cerebellar circuit in the KIKO mouse model of Friedreich ataxia. Dis Model Mech 2017; 10:1529-1538. [PMID: 29259026 PMCID: PMC5769605 DOI: 10.1242/dmm.030049] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 10/30/2017] [Indexed: 01/01/2023] Open
Abstract
Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder with progressive ataxia that affects both the peripheral and central nervous system (CNS). While later CNS neuropathology involves loss of large principal neurons and glutamatergic and GABAergic synaptic terminals in the cerebellar dentate nucleus, early pathological changes in FRDA cerebellum remain largely uncharacterized. Here, we report early cerebellar VGLUT1 (SLC17A7)-specific parallel fiber (PF) synaptic deficits and dysregulated cerebellar circuit in the frataxin knock-in/knockout (KIKO) FRDA mouse model. At asymptomatic ages, VGLUT1 levels in cerebellar homogenates are significantly decreased, whereas VGLUT2 (SLC17A6) levels are significantly increased, in KIKO mice compared with age-matched controls. Additionally, GAD65 (GAD2) levels are significantly increased, while GAD67 (GAD1) levels remain unaltered. This suggests early VGLUT1-specific synaptic input deficits, and dysregulation of VGLUT2 and GAD65 synaptic inputs, in the cerebellum of asymptomatic KIKO mice. Immunohistochemistry and electron microscopy further show specific reductions of VGLUT1-containing PF presynaptic terminals in the cerebellar molecular layer, demonstrating PF synaptic input deficiency in asymptomatic and symptomatic KIKO mice. Moreover, the parvalbumin levels in cerebellar homogenates and Purkinje neurons are significantly reduced, but preserved in other interneurons of the cerebellar molecular layer, suggesting specific parvalbumin dysregulation in Purkinje neurons of these mice. Furthermore, a moderate loss of large principal neurons is observed in the dentate nucleus of asymptomatic KIKO mice, mimicking that of FRDA patients. Our findings thus identify early VGLUT1-specific PF synaptic input deficits and dysregulated cerebellar circuit as potential mediators of cerebellar dysfunction in KIKO mice, reflecting developmental features of FRDA in this mouse model.
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Affiliation(s)
- Hong Lin
- Departments of Pediatrics and Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jordi Magrane
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Elisia M Clark
- Departments of Pediatrics and Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah M Halawani
- Departments of Pediatrics and Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Nathan Warren
- Departments of Pediatrics and Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Amy Rattelle
- Departments of Pediatrics and Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - David R Lynch
- Departments of Pediatrics and Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Chandran V, Gao K, Swarup V, Versano R, Dong H, Jordan MC, Geschwind DH. Inducible and reversible phenotypes in a novel mouse model of Friedreich's Ataxia. eLife 2017; 6:e30054. [PMID: 29257745 PMCID: PMC5736353 DOI: 10.7554/elife.30054] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 11/20/2017] [Indexed: 12/13/2022] Open
Abstract
Friedreich's ataxia (FRDA), the most common inherited ataxia, is caused by recessive mutations that reduce the levels of frataxin (FXN), a mitochondrial iron binding protein. We developed an inducible mouse model of Fxn deficiency that enabled us to control the onset and progression of disease phenotypes by the modulation of Fxn levels. Systemic knockdown of Fxn in adult mice led to multiple phenotypes paralleling those observed in human patients across multiple organ systems. By reversing knockdown after clinical features appear, we were able to determine to what extent observed phenotypes represent reversible cellular dysfunction. Remarkably, upon restoration of near wild-type FXN levels, we observed significant recovery of function, associated pathology and transcriptomic dysregulation even after substantial motor dysfunction and pathology were observed. This model will be of broad utility in therapeutic development and in refining our understanding of the relative contribution of reversible cellular dysfunction at different stages in disease.
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Affiliation(s)
- Vijayendran Chandran
- Program in Neurogenetics, Department of Neurology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
| | - Kun Gao
- Program in Neurogenetics, Department of Neurology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
| | - Vivek Swarup
- Program in Neurogenetics, Department of Neurology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
| | - Revital Versano
- Program in Neurogenetics, Department of Neurology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
| | - Hongmei Dong
- Program in Neurogenetics, Department of Neurology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
| | - Maria C Jordan
- Department of Physiology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
| | - Daniel H Geschwind
- Program in Neurogenetics, Department of Neurology, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
- Department of Human Genetics, David Geffen School of MedicineUniversity of California, Los AngelesLos AngelesUnited States
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Lin H, Magrane J, Rattelle A, Stepanova A, Galkin A, Clark EM, Dong YN, Halawani SM, Lynch DR. Early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in the KIKO mouse model of Friedreich ataxia. Dis Model Mech 2017; 10:1343-1352. [PMID: 29125827 PMCID: PMC5719255 DOI: 10.1242/dmm.030502] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/11/2017] [Indexed: 12/14/2022] Open
Abstract
Friedreich ataxia (FRDA), the most common recessive inherited ataxia, results from deficiency of frataxin, a small mitochondrial protein crucial for iron-sulphur cluster formation and ATP production. Frataxin deficiency is associated with mitochondrial dysfunction in FRDA patients and animal models; however, early mitochondrial pathology in FRDA cerebellum remains elusive. Using frataxin knock-in/knockout (KIKO) mice and KIKO mice carrying the mitoDendra transgene, we show early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in this FRDA model. At asymptomatic stages, the levels of PGC-1α (PPARGC1A), the mitochondrial biogenesis master regulator, are significantly decreased in cerebellar homogenates of KIKO mice compared with age-matched controls. Similarly, the levels of the PGC-1α downstream effectors, NRF1 and Tfam, are significantly decreased, suggesting early impaired cerebellar mitochondrial biogenesis pathways. Early mitochondrial deficiency is further supported by significant reduction of the mitochondrial markers GRP75 (HSPA9) and mitofusin-1 in the cerebellar cortex. Moreover, the numbers of Dendra-labeled mitochondria are significantly decreased in cerebellar cortex, confirming asymptomatic cerebellar mitochondrial biogenesis deficits. Functionally, complex I and II enzyme activities are significantly reduced in isolated mitochondria and tissue homogenates from asymptomatic KIKO cerebella. Structurally, levels of the complex I core subunit NUDFB8 and complex II subunits SDHA and SDHB are significantly lower than those in age-matched controls. These results demonstrate complex I and II deficiency in KIKO cerebellum, consistent with defects identified in FRDA patient tissues. Thus, our findings identify early cerebellar mitochondrial biogenesis deficits as a potential mediator of cerebellar dysfunction and ataxia, thereby providing a potential therapeutic target for early intervention of FRDA.
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Affiliation(s)
- Hong Lin
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jordi Magrane
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Amy Rattelle
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Anna Stepanova
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Alexander Galkin
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Elisia M Clark
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi Na Dong
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Sarah M Halawani
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - David R Lynch
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Miller JL, Rai M, Frigon NL, Pandolfo M, Punnonen J, Spencer JR. Erythropoietin and small molecule agonists of the tissue-protective erythropoietin receptor increase FXN expression in neuronal cells in vitro and in Fxn-deficient KIKO mice in vivo. Neuropharmacology 2017; 123:34-45. [PMID: 28504123 DOI: 10.1016/j.neuropharm.2017.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 12/19/2022]
Abstract
Friedreich's ataxia (FA) is a progressive neurodegenerative disease caused by reduced levels of the mitochondrial protein frataxin (FXN). Recombinant human erythropoietin (rhEPO) increased FXN protein in vitro and in early clinical studies, while no published reports evaluate rhEPO in animal models of FA. STS-E412 and STS-E424 are novel small molecule agonists of the tissue-protective, but not the erythropoietic EPO receptor. We find that rhEPO, STS-E412 and STS-E424 increase FXN expression in vitro and in vivo. RhEPO, STS-E412 and STS-E424 increase FXN by up to 2-fold in primary human cortical cells and in retinoic-acid differentiated murine P19 cells. In primary human cortical cells, the increase in FXN protein was accompanied by an increase in FXN mRNA, detectable within 4 h. RhEPO and low nanomolar concentrations of STS-E412 and STS-E424 also increase FXN in normal and FA patient-derived PBMC by 20%-40% within 24 h, an effect that was comparable to that by HDAC inhibitor 4b. In vivo, STS-E412 increased Fxn mRNA and protein in wild-type C57BL6/j mice. RhEPO, STS-E412, and STS-E424 increase FXN expression in the heart of FXN-deficient KIKO mice. In contrast, FXN expression in the brains of KIKO mice increased following treatment with STS-E412 and STS-E424, but not following treatment with rhEPO. Unexpectedly, rhEPO-treated KIKO mice developed severe splenomegaly, while no splenomegaly was observed in STS-E412- or STS-E424-treated mice. RhEPO, STS-E412 and STS-E424 upregulate FXN expression in vitro at equal efficacy, however, the effects of the small molecules on FXN expression in the CNS are superior to rhEPO in vivo.
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Affiliation(s)
- James L Miller
- STATegics, Inc., 428 Oakmead Pkwy, Sunnyvale, CA 94085, USA.
| | - Myriam Rai
- Université Libre de Bruxelles, Campus Erasme, CP601, Route de Lennik 808, 1070 Bruxelles, Belgium
| | | | - Massimo Pandolfo
- Université Libre de Bruxelles, Campus Erasme, CP601, Route de Lennik 808, 1070 Bruxelles, Belgium
| | - Juha Punnonen
- STATegics, Inc., 428 Oakmead Pkwy, Sunnyvale, CA 94085, USA
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Ollagnier de Choudens S, Barras F. Genetic, Biochemical, and Biophysical Methods for Studying FeS Proteins and Their Assembly. Methods Enzymol 2017; 595:1-32. [PMID: 28882198 DOI: 10.1016/bs.mie.2017.07.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
FeS clusters containing proteins are structurally and functionally diverse and present in most organisms. Our understanding of FeS cluster production and insertion into polypeptides has benefited from collaborative efforts between in vitro and in vivo studies. The former allows a detailed description of FeS-containing protein and a deep understanding of the molecular mechanisms catalyzing FeS cluster assembly. The second allows to include metabolic and environmental constraints within the analysis of FeS homeostasis. The interplay and the cross talk between the two approaches have been a key strategy to reach a multileveled integrated understanding of FeS cluster homeostasis. In this chapter, we describe the genetic and biochemical/biophysical strategies that were used in the field of FeS cluster biogenesis, with the aim of providing the reader with a critical view of both approaches. In addition to the description of classic tricks and a series of recommendations, we will also discuss models as well as spectroscopic techniques useful to characterize FeS clusters such as UV-visible, Mössbauer, electronic paramagnetic resonance, resonance Raman, circular dichroism, and nuclear magnetic resonance.
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Affiliation(s)
- Sandrine Ollagnier de Choudens
- Université Grenoble Alpes, Laboratoire de Chimie et Biologie des Métaux, BioCat, Grenoble, France; CNRS, Laboratoire de Chimie et Biologie des Métaux, BioCat, UMR, Grenoble, France; CEA-Grenoble, DRF/BIG/CBM, Grenoble, France.
| | - Frédéric Barras
- Laboratoire Chimie Bactérienne, Université Aix-Marseille, CNRS, Marseille, France.
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Franco C, Genis L, Navarro JA, Perez-Domper P, Fernandez AM, Schneuwly S, Torres Alemán I. A role for astrocytes in cerebellar deficits in frataxin deficiency: Protection by insulin-like growth factor I. Mol Cell Neurosci 2017; 80:100-110. [PMID: 28286293 DOI: 10.1016/j.mcn.2017.02.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/16/2017] [Accepted: 02/25/2017] [Indexed: 12/29/2022] Open
Abstract
Inherited neurodegenerative diseases such as Friedreich's ataxia (FRDA), produced by deficiency of the mitochondrial chaperone frataxin (Fxn), shows specific neurological deficits involving different subset of neurons even though deficiency of Fxn is ubiquitous. Because astrocytes are involved in neurodegeneration, we analyzed whether they are also affected by frataxin deficiency and contribute to the disease. We also tested whether insulin-like growth factor I (IGF-I), that has proven effective in increasing frataxin levels both in neurons and in astrocytes, also exerts in vivo protective actions. Using the GFAP promoter expressed by multipotential stem cells during development and mostly by astrocytes in the adult, we ablated Fxn in a time-dependent manner in mice (FGKO mice) and found severe ataxia and early death when Fxn was eliminated during development, but not when deleted in the adult. Analysis of underlying mechanisms revealed that Fxn deficiency elicited growth and survival impairments in developing cerebellar astrocytes, whereas forebrain astrocytes grew normally. A similar time-dependent effect of frataxin deficiency in astrocytes was observed in a fly model. In addition, treatment of FGKO mice with IGF-I improved their motor performance, reduced cerebellar atrophy, and increased survival. These observations indicate that a greater vulnerability of developing cerebellar astrocytes to Fxn deficiency may contribute to cerebellar deficits in this inherited disease. Our data also confirm a therapeutic benefit of IGF-I in early FRDA deficiency.
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Affiliation(s)
- C Franco
- Cajal Institute, CSIC, Madrid, Spain; CIBERNED, Spain
| | - L Genis
- Cajal Institute, CSIC, Madrid, Spain; CIBERNED, Spain
| | | | | | - A M Fernandez
- Cajal Institute, CSIC, Madrid, Spain; CIBERNED, Spain
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McMackin MZ, Henderson CK, Cortopassi GA. Neurobehavioral deficits in the KIKO mouse model of Friedreich's ataxia. Behav Brain Res 2017; 316:183-188. [PMID: 27575947 PMCID: PMC5051948 DOI: 10.1016/j.bbr.2016.08.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 11/30/2022]
Abstract
Friedreich's Ataxia (FA) is a pediatric neurodegenerative disease whose clinical presentation includes ataxia, muscle weakness, and peripheral sensory neuropathy. The KIKO mouse is an animal model of FA with frataxin deficiency first described in 2002, but neurobehavioral deficits have never been described in this model. The identification of robust neurobehavioral deficits in KIKO mice could support the testing of drugs for FA, which currently has no approved therapy. We tested 13 neurobehavioral tasks to identify a robust KIKO phenotype: Open Field, Grip Strength Test(s), Cylinder, Skilled Forelimb Grasp Task(s), Treadmill Endurance, Locotronic Motor Coordination, Inverted Screen, Treadscan, and Von Frey. Of these, Inverted Screen, Treadscan and Von Frey produced significant neurobehavioral deficits at >8 months of age, and relate to the clinically relevant endpoints of muscle strength and endurance, gait ataxia, and peripheral insensitivity. Thus we identify robust phenotypic measures related to Friedreich's ataxia clinical endpoints which could be used to test effectiveness of potential drug therapy.
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Affiliation(s)
- Marissa Z McMackin
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA
| | - Chelsea K Henderson
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA
| | - Gino A Cortopassi
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA.
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Polak U, Li Y, Butler JS, Napierala M. Alleviating GAA Repeat Induced Transcriptional Silencing of the Friedreich's Ataxia Gene During Somatic Cell Reprogramming. Stem Cells Dev 2016; 25:1788-1800. [PMID: 27615158 PMCID: PMC5155629 DOI: 10.1089/scd.2016.0147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/09/2016] [Indexed: 12/13/2022] Open
Abstract
Friedreich's ataxia (FRDA) is the most common autosomal recessive ataxia. This severe neurodegenerative disease is caused by an expansion of guanine-adenine-adenine (GAA) repeats located in the first intron of the frataxin (FXN) gene, which represses its transcription. Although transcriptional silencing is associated with heterochromatin-like changes in the vicinity of the expanded GAAs, the exact mechanism and pathways involved in transcriptional inhibition are largely unknown. As major remodeling of the epigenome is associated with somatic cell reprogramming, modulating chromatin modification pathways during the cellular transition from a somatic to a pluripotent state is likely to generate permanent changes to the epigenetic landscape. We hypothesize that the epigenetic modifications in the vicinity of the GAA repeats can be reversed by pharmacological modulation during somatic cell reprogramming. We reprogrammed FRDA fibroblasts into induced pluripotent stem cells (iPSCs) in the presence of various small molecules that target DNA methylation and histone acetylation and methylation. Treatment of FRDA iPSCs with two compounds, sodium butyrate (NaB) and Parnate, led to an increase in FXN expression and correction of repressive marks at the FXN locus, which persisted for several passages. However, prolonged culture of the epigenetically modified FRDA iPSCs led to progressive expansions of the GAA repeats and a corresponding decrease in FXN expression. Furthermore, we uncovered that differentiation of these iPSCs into neurons also results in resilencing of the FXN gene. Taken together, these results demonstrate that transcriptional repression caused by long GAA repeat tracts can be partially or transiently reversed by altering particular epigenetic modifications, thus revealing possibilities for detailed analyses of silencing mechanism and development of new therapeutic approaches for FRDA.
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Affiliation(s)
- Urszula Polak
- Department of Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Smithville, Texas
| | - Yanjie Li
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jill Sergesketter Butler
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
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Abeti R, Parkinson MH, Hargreaves IP, Angelova PR, Sandi C, Pook MA, Giunti P, Abramov AY. 'Mitochondrial energy imbalance and lipid peroxidation cause cell death in Friedreich's ataxia'. Cell Death Dis 2016; 7:e2237. [PMID: 27228352 PMCID: PMC4917650 DOI: 10.1038/cddis.2016.111] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/04/2016] [Accepted: 03/16/2016] [Indexed: 12/27/2022]
Abstract
Friedreich's ataxia (FRDA) is an inherited neurodegenerative disease. The mutation consists of a GAA repeat expansion within the FXN gene, which downregulates frataxin, leading to abnormal mitochondrial iron accumulation, which may in turn cause changes in mitochondrial function. Although, many studies of FRDA patients and mouse models have been conducted in the past two decades, the role of frataxin in mitochondrial pathophysiology remains elusive. Are the mitochondrial abnormalities only a side effect of the increased accumulation of reactive iron, generating oxidative stress? Or does the progressive lack of iron-sulphur clusters (ISCs), induced by reduced frataxin, cause an inhibition of the electron transport chain complexes (CI, II and III) leading to reactive oxygen species escaping from oxidative phosphorylation reactions? To answer these crucial questions, we have characterised the mitochondrial pathophysiology of a group of disease-relevant and readily accessible neurons, cerebellar granule cells, from a validated FRDA mouse model. By using live cell imaging and biochemical techniques we were able to demonstrate that mitochondria are deregulated in neurons from the YG8R FRDA mouse model, causing a decrease in mitochondrial membrane potential (▵Ψm) due to an inhibition of Complex I, which is partially compensated by an overactivation of Complex II. This complex activity imbalance leads to ROS generation in both mitochondrial matrix and cytosol, which results in glutathione depletion and increased lipid peroxidation. Preventing this increase in lipid peroxidation, in neurons, protects against in cell death. This work describes the pathophysiological properties of the mitochondria in neurons from a FRDA mouse model and shows that lipid peroxidation could be an important target for novel therapeutic strategies in FRDA, which still lacks a cure.
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Affiliation(s)
- R Abeti
- Ataxia Centre, Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, London, UK
| | - M H Parkinson
- Ataxia Centre, Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, London, UK
| | | | - P R Angelova
- Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, London, UK
| | - C Sandi
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, and Synthetic Biology Theme, Institute of Environment, Health & Societies, Brunel University London, Uxbridge, UK
| | - M A Pook
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, and Synthetic Biology Theme, Institute of Environment, Health & Societies, Brunel University London, Uxbridge, UK
| | - P Giunti
- Ataxia Centre, Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, London, UK
| | - A Y Abramov
- Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, London, UK
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Watson LM, Wong MMK, Becker EBE. Induced pluripotent stem cell technology for modelling and therapy of cerebellar ataxia. Open Biol 2016; 5:150056. [PMID: 26136256 PMCID: PMC4632502 DOI: 10.1098/rsob.150056] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Induced pluripotent stem cell (iPSC) technology has emerged as an important tool in understanding, and potentially reversing, disease pathology. This is particularly true in the case of neurodegenerative diseases, in which the affected cell types are not readily accessible for study. Since the first descriptions of iPSC-based disease modelling, considerable advances have been made in understanding the aetiology and progression of a diverse array of neurodegenerative conditions, including Parkinson's disease and Alzheimer's disease. To date, however, relatively few studies have succeeded in using iPSCs to model the neurodegeneration observed in cerebellar ataxia. Given the distinct neurodevelopmental phenotypes associated with certain types of ataxia, iPSC-based models are likely to provide significant insights, not only into disease progression, but also to the development of early-intervention therapies. In this review, we describe the existing iPSC-based disease models of this heterogeneous group of conditions and explore the challenges associated with generating cerebellar neurons from iPSCs, which have thus far hindered the expansion of this research.
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Affiliation(s)
- Lauren M Watson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Maggie M K Wong
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Esther B E Becker
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Crombie DE, Pera MF, Delatycki MB, Pébay A. Using human pluripotent stem cells to study Friedreich ataxia cardiomyopathy. Int J Cardiol 2016; 212:37-43. [PMID: 27019046 DOI: 10.1016/j.ijcard.2016.03.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 03/02/2016] [Accepted: 03/13/2016] [Indexed: 12/16/2022]
Abstract
Friedreich ataxia (FRDA) is the most common of the inherited ataxias. It is an autosomal recessive disease characterised by degeneration of peripheral sensory neurons, regions of the central nervous system and cardiomyopathy. FRDA is usually due to homozygosity for trinucleotide GAA repeat expansions found within first intron of the FRATAXIN (FXN) gene, which results in reduced levels of the mitochondrial protein FXN. Reduced FXN protein results in mitochondrial dysfunction and iron accumulation leading to increased oxidative stress and cell death in the nervous system and heart. Yet the precise functions of FXN and the underlying mechanisms leading to disease pathology remain elusive. This is particularly true of the cardiac aspect of FRDA, which remains largely uncharacterized at the cellular level. Here, we summarise current knowledge on experimental models in which to study FRDA cardiomyopathy, with a particular focus on the use of human pluripotent stem cells as a disease model.
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Affiliation(s)
- Duncan E Crombie
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Australia
| | - Martin F Pera
- Department of Anatomy and Neurosciences, The University of Melbourne, Florey Neuroscience & Mental Health Institute, Walter and Eliza Hall Institute of Medical Research, Australia
| | - Martin B Delatycki
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Department of Paediatrics, The University of Melbourne, Australia; School of Psychology and Psychiatry, Monash University, Australia; Clinical Genetics, Austin Health, Australia
| | - Alice Pébay
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Australia.
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44
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Shen Y, McMackin MZ, Shan Y, Raetz A, David S, Cortopassi G. Frataxin Deficiency Promotes Excess Microglial DNA Damage and Inflammation that Is Rescued by PJ34. PLoS One 2016; 11:e0151026. [PMID: 26954031 PMCID: PMC4783034 DOI: 10.1371/journal.pone.0151026] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 02/23/2016] [Indexed: 12/13/2022] Open
Abstract
An inherited deficiency in the frataxin protein causes neurodegeneration of the dorsal root ganglia and Friedreich's ataxia (FA). Frataxin deficiency leads to oxidative stress and inflammatory changes in cell and animal models; however, the cause of the inflammatory changes, and especially what causes brain microglial activation is unclear. Here we investigated: 1) the mechanism by which frataxin deficiency activates microglia, 2) whether a brain-localized inflammatory stimulus provokes a greater microglial response in FA animal models, and 3) whether an anti-inflammatory treatment improves their condition. Intracerebroventricular administration of LPS induced higher amounts of microglial activation in the FA mouse model vs controls. We also observed an increase in oxidative damage in the form of 8-oxoguanine (8-oxo-G) and the DNA repair proteins MUTYH and PARP-1 in cerebellar microglia of FA mutant mice. We hypothesized that frataxin deficiency increases DNA damage and DNA repair genes specifically in microglia, activating them. siRNA-mediated frataxin knockdown in microglial BV2 cells clearly elevated DNA damage and the expression of DNA repair genes MUTYH and PARP-1. Frataxin knockdown also induced a higher level of PARP-1 in MEF cells, and this was suppressed in MUTYH-/- knockout cells. Administration of the PARP-1 inhibitor PJ34 attenuated the microglial activation induced by intracerebroventricular injection of LPS. The combined administration of LPS and angiotensin II provoke an even stronger activation of microglia and neurobehavioral impairment. PJ34 treatment attenuated the neurobehavioral impairments in FA mice. These results suggest that the DNA repair proteins MUTYH and PARP-1 may form a pathway regulating microglial activation initiated by DNA damage, and inhibition of microglial PARP-1 induction could be an important therapeutic target in Friedreich's ataxia.
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Affiliation(s)
- Yan Shen
- Department of Molecular Biosciences, University of California Davis, Davis, California, 95616, United States of America
| | - Marissa Z. McMackin
- Department of Molecular Biosciences, University of California Davis, Davis, California, 95616, United States of America
| | - Yuxi Shan
- Department of Molecular Biosciences, University of California Davis, Davis, California, 95616, United States of America
| | - Alan Raetz
- Department of Chemistry, University of California Davis, Davis, California, 95616, United States of America
| | - Sheila David
- Department of Chemistry, University of California Davis, Davis, California, 95616, United States of America
| | - Gino Cortopassi
- Department of Molecular Biosciences, University of California Davis, Davis, California, 95616, United States of America
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Li Y, Lu Y, Polak U, Lin K, Shen J, Farmer J, Seyer L, Bhalla AD, Rozwadowska N, Lynch DR, Butler JS, Napierala M. Expanded GAA repeats impede transcription elongation through the FXN gene and induce transcriptional silencing that is restricted to the FXN locus. Hum Mol Genet 2015; 24:6932-43. [PMID: 26401053 PMCID: PMC4654050 DOI: 10.1093/hmg/ddv397] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/21/2015] [Indexed: 11/13/2022] Open
Abstract
Friedreich's ataxia (FRDA) is a severe neurodegenerative disease caused by homozygous expansion of the guanine-adenine-adenine (GAA) repeats in intron 1 of the FXN gene leading to transcriptional repression of frataxin expression. Post-translational histone modifications that typify heterochromatin are enriched in the vicinity of the repeats, whereas active chromatin marks in this region are underrepresented in FRDA samples. Yet, the immediate effect of the expanded repeats on transcription progression through FXN and their long-range effect on the surrounding genomic context are two critical questions that remain unanswered in the molecular pathogenesis of FRDA. To address these questions, we conducted next-generation RNA sequencing of a large cohort of FRDA and control primary fibroblasts. This comprehensive analysis revealed that the GAA-induced silencing effect does not influence expression of neighboring genes upstream or downstream of FXN. Furthermore, no long-range silencing effects were detected across a large portion of chromosome 9. Additionally, results of chromatin immunoprecipitation studies confirmed that histone modifications associated with repressed transcription are confined to the FXN locus. Finally, deep sequencing of FXN pre-mRNA molecules revealed a pronounced defect in the transcription elongation rate in FRDA cells when compared with controls. These results indicate that approaches aimed to reactivate frataxin expression should simultaneously address deficits in transcription initiation and elongation at the FXN locus.
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Affiliation(s)
- Yanjie Li
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Yue Lu
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957, USA
| | - Urszula Polak
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957, USA, Department of Cell Biology, Poznan University of Medical Sciences, Rokietnicka 5D, Poznan 60-806, Poland
| | - Kevin Lin
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957, USA
| | - Jianjun Shen
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957, USA
| | - Jennifer Farmer
- Division of Neurology and Pediatrics, Children's Hospital of Philadelphia, Abramson Research Center Room 502, Philadelphia, PA 19104, USA
| | - Lauren Seyer
- Division of Neurology and Pediatrics, Children's Hospital of Philadelphia, Abramson Research Center Room 502, Philadelphia, PA 19104, USA
| | - Angela D Bhalla
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Natalia Rozwadowska
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA, Institute of Human Genetics, Polish Academy of Science, Strzeszynska 32, Poznan 60-479, Poland
| | - David R Lynch
- Division of Neurology and Pediatrics, Children's Hospital of Philadelphia, Abramson Research Center Room 502, Philadelphia, PA 19104, USA
| | - Jill Sergesketter Butler
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA,
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA, Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland and
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Hayashi G, Cortopassi G. Oxidative stress in inherited mitochondrial diseases. Free Radic Biol Med 2015; 88:10-7. [PMID: 26073122 PMCID: PMC4593728 DOI: 10.1016/j.freeradbiomed.2015.05.039] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/10/2015] [Accepted: 05/26/2015] [Indexed: 12/22/2022]
Abstract
Mitochondria are a source of reactive oxygen species (ROS). Mitochondrial diseases are the result of inherited defects in mitochondrially expressed genes. One potential pathomechanism for mitochondrial disease is oxidative stress. Oxidative stress can occur as the result of increased ROS production or decreased ROS protection. The role of oxidative stress in the five most common inherited mitochondrial diseases, Friedreich ataxia, LHON, MELAS, MERRF, and Leigh syndrome (LS), is discussed. Published reports of oxidative stress involvement in the pathomechanisms of these five mitochondrial diseases are reviewed. The strongest evidence for an oxidative stress pathomechanism among the five diseases was for Friedreich ataxia. In addition, a meta-analysis was carried out to provide an unbiased evaluation of the role of oxidative stress in the five diseases, by searching for "oxidative stress" citation count frequency for each disease. Of the five most common mitochondrial diseases, the strongest support for oxidative stress is for Friedreich ataxia (6.42%), followed by LHON (2.45%), MELAS (2.18%), MERRF (1.71%), and LS (1.03%). The increased frequency of oxidative stress citations was significant relative to the mean of the total pool of five diseases (p<0.01) and the mean of the four non-Friedreich diseases (p<0.0001). Thus there is support for oxidative stress in all five most common mitochondrial diseases, but the strongest, significant support is for Friedreich ataxia.
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Affiliation(s)
- Genki Hayashi
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA
| | - Gino Cortopassi
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA.
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47
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Abeti R, Uzun E, Renganathan I, Honda T, Pook MA, Giunti P. Targeting lipid peroxidation and mitochondrial imbalance in Friedreich's ataxia. Pharmacol Res 2015; 99:344-50. [PMID: 26141703 DOI: 10.1016/j.phrs.2015.05.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 05/04/2015] [Accepted: 05/15/2015] [Indexed: 11/24/2022]
Abstract
Friedreich's ataxia (FRDA) is an autosomal recessive disorder, caused by reduced levels of the protein frataxin. This protein is located in the mitochondria, where it functions in the biogenesis of iron-sulphur clusters (ISCs), which are important for the function of the mitochondrial respiratory chain complexes. Moreover, disruption in iron biogenesis may lead to oxidative stress. Oxidative stress can be the cause and/or the consequence of mitochondrial energy imbalance, leading to cell death. Fibroblasts from two FRDA mouse models, YG8R and KIKO, were used to analyse two different categories of protective compounds: deuterised poly-unsaturated fatty acids (dPUFAs) and Nrf2-inducers. The former have been shown to protect the cell from damage induced by lipid peroxidation and the latter trigger the well-known Nrf2 antioxidant pathway. Our results show that the sensitivity to oxidative stress of YG8R and KIKO mouse fibroblasts, resulting in cell death and lipid peroxidation, can be prevented by d4-PUFA and Nrf2-inducers (SFN and TBE-31). The mitochondrial membrane potential (ΔΨm) of YG8R and KIKO fibroblasts revealed a difference in their mitochondrial pathophysiology, which may be due to the different genetic basis of the two models. This suggests that variable levels of reduced frataxin may act differently on mitochondrial pathophysiology and that these two cell models could be useful in recapitulating the observed differences in the FRDA phenotype. This may reflect a different modulatory effect towards cell death that will need to be investigated further.
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Affiliation(s)
- Rosella Abeti
- Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, WC1N 3BG London, UK
| | - Ebru Uzun
- Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, WC1N 3BG London, UK
| | - Indhushri Renganathan
- Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, WC1N 3BG London, UK
| | - Tadashi Honda
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, United States
| | - Mark A Pook
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences Synthetic Biology Theme, Institute of Environment, Health & Societies, Brunel University London, Uxbridge UB8 3PH, UK
| | - Paola Giunti
- Department of Molecular Neuroscience, UCL, Institute of Neurology, Queen Square, WC1N 3BG London, UK.
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48
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Li Y, Polak U, Bhalla AD, Rozwadowska N, Butler JS, Lynch DR, Dent SYR, Napierala M. Excision of Expanded GAA Repeats Alleviates the Molecular Phenotype of Friedreich's Ataxia. Mol Ther 2015; 23:1055-1065. [PMID: 25758173 DOI: 10.1038/mt.2015.41] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 03/03/2015] [Indexed: 12/21/2022] Open
Abstract
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. The expression of FRDA biomarkers was normalized in corrected patient cells and disease-associated phenotypes, such as decreases in aconitase activity and intracellular ATP levels, were reversed in zinc finger nuclease corrected neuronal cells. Genetically and phenotypically corrected patient cells represent not only a preferred disease-relevant model system to study pathogenic mechanisms, but also a critical step towards development of cell replacement therapy.
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Affiliation(s)
- Yanjie Li
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Urszula Polak
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Science Park, Smithville, Texas, USA; Department of Cell Biology, Poznan University of Medical Sciences, Poznan, Poland
| | - Angela D Bhalla
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Natalia Rozwadowska
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA; Institute of Human Genetics, Polish Academy of Science, Poznan, Poland
| | - Jill Sergesketter Butler
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David R Lynch
- Division of Neurology and Pediatrics, Children's Hospital of Philadelphia, Abramson Research Center, Philadelphia, Pennsylvania, USA
| | - Sharon Y R Dent
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Science Park, Smithville, Texas, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA; Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.
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49
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Anjomani Virmouni S, Ezzatizadeh V, Sandi C, Sandi M, Al-Mahdawi S, Chutake Y, Pook MA. A novel GAA-repeat-expansion-based mouse model of Friedreich's ataxia. Dis Model Mech 2015; 8:225-35. [PMID: 25681319 PMCID: PMC4348561 DOI: 10.1242/dmm.018952] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 02/02/2015] [Indexed: 02/06/2023] Open
Abstract
Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by a GAA repeat expansion mutation within intron 1 of the FXN gene, resulting in reduced levels of frataxin protein. We have previously reported the generation of human FXN yeast artificial chromosome (YAC) transgenic FRDA mouse models containing 90-190 GAA repeats, but the presence of multiple GAA repeats within these mice is considered suboptimal. We now describe the cellular, molecular and behavioural characterisation of a newly developed YAC transgenic FRDA mouse model, designated YG8sR, which we have shown by DNA sequencing to contain a single pure GAA repeat expansion. The founder YG8sR mouse contained 120 GAA repeats but, due to intergenerational expansion, we have now established a colony of YG8sR mice that contain ~200 GAA repeats. We show that YG8sR mice have a single copy of the FXN transgene, which is integrated at a single site as confirmed by fluorescence in situ hybridisation (FISH) analysis of metaphase and interphase chromosomes. We have identified significant behavioural deficits, together with a degree of glucose intolerance and insulin hypersensitivity, in YG8sR FRDA mice compared with control Y47R and wild-type (WT) mice. We have also detected increased somatic GAA repeat instability in the brain and cerebellum of YG8sR mice, together with significantly reduced expression of FXN, FAST-1 and frataxin, and reduced aconitase activity, compared with Y47R mice. Furthermore, we have confirmed the presence of pathological vacuoles within neurons of the dorsal root ganglia (DRG) of YG8sR mice. These novel GAA-repeat-expansion-based YAC transgenic FRDA mice, which exhibit progressive FRDA-like pathology, represent an excellent model for the investigation of FRDA disease mechanisms and therapy.
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Affiliation(s)
- Sara Anjomani Virmouni
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Vahid Ezzatizadeh
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Chiranjeevi Sandi
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Madhavi Sandi
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Sahar Al-Mahdawi
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Yogesh Chutake
- Department of Pediatrics, Section of Genetics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Mark A Pook
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UB8 3PH, UK
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50
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Iommarini L, Peralta S, Torraco A, Diaz F. Mitochondrial Diseases Part II: Mouse models of OXPHOS deficiencies caused by defects in regulatory factors and other components required for mitochondrial function. Mitochondrion 2015; 22:96-118. [PMID: 25640959 DOI: 10.1016/j.mito.2015.01.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 01/22/2015] [Indexed: 01/21/2023]
Abstract
Mitochondrial disorders are defined as defects that affect the oxidative phosphorylation system (OXPHOS). They are characterized by a heterogeneous array of clinical presentations due in part to a wide variety of factors required for proper function of the components of the OXPHOS system. There is no cure for these disorders owing to our poor knowledge of the pathogenic mechanisms of disease. To understand the mechanisms of human disease numerous mouse models have been developed in recent years. Here we summarize the features of several mouse models of mitochondrial diseases directly related to those factors affecting mtDNA maintenance, replication, transcription, translation as well as other proteins that are involved in mitochondrial dynamics and quality control which affect mitochondrial OXPHOS function without being intrinsic components of the system. We discuss how these models have contributed to our understanding of mitochondrial diseases and their pathogenic mechanisms.
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Affiliation(s)
- Luisa Iommarini
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 42, 40128 Bologna, Italy.
| | - Susana Peralta
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
| | - Alessandra Torraco
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Viale di San Paolo, 15 - 00146, Rome, Italy.
| | - Francisca Diaz
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
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