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VanPortfliet JJ, Chute C, Lei Y, Shutt TE, West AP. Mitochondrial DNA release and sensing in innate immune responses. Hum Mol Genet 2024; 33:R80-R91. [PMID: 38779772 PMCID: PMC11112387 DOI: 10.1093/hmg/ddae031] [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: 01/27/2024] [Accepted: 02/09/2024] [Indexed: 05/25/2024] Open
Abstract
Mitochondria are pleiotropic organelles central to an array of cellular pathways including metabolism, signal transduction, and programmed cell death. Mitochondria are also key drivers of mammalian immune responses, functioning as scaffolds for innate immune signaling, governing metabolic switches required for immune cell activation, and releasing agonists that promote inflammation. Mitochondrial DNA (mtDNA) is a potent immunostimulatory agonist, triggering pro-inflammatory and type I interferon responses in a host of mammalian cell types. Here we review recent advances in how mtDNA is detected by nucleic acid sensors of the innate immune system upon release into the cytoplasm and extracellular space. We also discuss how the interplay between mtDNA release and sensing impacts cellular innate immune endpoints relevant to health and disease.
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Affiliation(s)
- Jordyn J VanPortfliet
- The Jackson Laboratory, Bar Harbor, ME 04609, United States
- Department of Microbial Pathogenesis and Immunology, School of Medicine, Texas A&M University, Bryan, TX 77807, United States
| | - Cole Chute
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Yuanjiu Lei
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, United States
| | - Timothy E Shutt
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - A Phillip West
- The Jackson Laboratory, Bar Harbor, ME 04609, United States
- Department of Microbial Pathogenesis and Immunology, School of Medicine, Texas A&M University, Bryan, TX 77807, United States
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2
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Ast T, Itoh Y, Sadre S, McCoy JG, Namkoong G, Wengrod JC, Chicherin I, Joshi PR, Kamenski P, Suess DLM, Amunts A, Mootha VK. METTL17 is an Fe-S cluster checkpoint for mitochondrial translation. Mol Cell 2024; 84:359-374.e8. [PMID: 38199006 PMCID: PMC11046306 DOI: 10.1016/j.molcel.2023.12.016] [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: 11/02/2022] [Revised: 08/13/2023] [Accepted: 12/12/2023] [Indexed: 01/12/2024]
Abstract
Friedreich's ataxia (FA) is a debilitating, multisystemic disease caused by the depletion of frataxin (FXN), a mitochondrial iron-sulfur (Fe-S) cluster biogenesis factor. To understand the cellular pathogenesis of FA, we performed quantitative proteomics in FXN-deficient human cells. Nearly every annotated Fe-S cluster-containing protein was depleted, indicating that as a rule, cluster binding confers stability to Fe-S proteins. We also observed depletion of a small mitoribosomal assembly factor METTL17 and evidence of impaired mitochondrial translation. Using comparative sequence analysis, mutagenesis, biochemistry, and cryoelectron microscopy, we show that METTL17 binds to the mitoribosomal small subunit during late assembly and harbors a previously unrecognized [Fe4S4]2+ cluster required for its stability. METTL17 overexpression rescued the mitochondrial translation and bioenergetic defects, but not the cellular growth, of FXN-depleted cells. These findings suggest that METTL17 acts as an Fe-S cluster checkpoint, promoting translation of Fe-S cluster-rich oxidative phosphorylation (OXPHOS) proteins only when Fe-S cofactors are replete.
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Affiliation(s)
- Tslil Ast
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Yuzuru Itoh
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Shayan Sadre
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Jason G McCoy
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Gil Namkoong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jordan C Wengrod
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Ivan Chicherin
- Department of Biology, M.V.Lomonosov Moscow State University, Moscow 119234, Russia
| | - Pallavi R Joshi
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Piotr Kamenski
- Department of Biology, M.V.Lomonosov Moscow State University, Moscow 119234, Russia
| | - Daniel L M Suess
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Vamsi K Mootha
- Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
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3
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Indelicato E, Faserl K, Amprosi M, Nachbauer W, Schneider R, Wanschitz J, Sarg B, Boesch S. Skeletal muscle proteome analysis underpins multifaceted mitochondrial dysfunction in Friedreich's ataxia. Front Neurosci 2023; 17:1289027. [PMID: 38027498 PMCID: PMC10644315 DOI: 10.3389/fnins.2023.1289027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
Friedreich's ataxia (FRDA) is a severe multisystemic disorder caused by a deficiency of the mitochondrial protein frataxin. While some aspects of FRDA pathology are developmental, the causes underlying the steady progression are unclear. The inaccessibility of key affected tissues to sampling is a main hurdle. Skeletal muscle displays a disease phenotype and may be sampled in vivo to address open questions on FRDA pathophysiology. Thus, we performed a quantitative mass spectrometry-based proteomics analysis in gastrocnemius skeletal muscle biopsies from genetically confirmed FRDA patients (n = 5) and controls. Obtained data files were processed using Proteome Discoverer and searched by Sequest HT engine against a UniProt human reference proteome database. Comparing skeletal muscle proteomics profiles between FRDA and controls, we identified 228 significant differentially expressed (DE) proteins, of which 227 were downregulated in FRDA. Principal component analysis showed a clear separation between FRDA and control samples. Interactome analysis revealed clustering of DE proteins in oxidative phosphorylation, ribosomal elements, mitochondrial architecture control, and fission/fusion pathways. DE findings in the muscle-specific proteomics suggested a shift toward fast-twitching glycolytic fibers. Notably, most DE proteins (169/228, 74%) are target of the transcription factor nuclear factor-erythroid 2. Our data corroborate a mitochondrial biosignature of FRDA, which extends beyond a mere oxidative phosphorylation failure. Skeletal muscle proteomics highlighted a derangement of mitochondrial architecture and maintenance pathways and a likely adaptive metabolic shift of contractile proteins. The present findings are relevant for the design of future therapeutic strategies and highlight the value of skeletal muscle-omics as disease state readout in FRDA.
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Affiliation(s)
- Elisabetta Indelicato
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Klaus Faserl
- Institute of Medical Biochemistry, Protein Core Facility, Medical University of Innsbruck, Innsbruck, Austria
| | - Matthias Amprosi
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wolfgang Nachbauer
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Rainer Schneider
- Institute of Biochemistry, Center of Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens University Innsbruck, Innsbruck, Austria
| | - Julia Wanschitz
- Laboratory of Tissue Diagnostics, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Bettina Sarg
- Institute of Medical Biochemistry, Protein Core Facility, Medical University of Innsbruck, Innsbruck, Austria
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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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: 4] [Impact Index Per Article: 4.0] [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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5
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Dionisi C, Chazalon M, Rai M, Keime C, Imbault V, Communi D, Puccio H, Schiffmann SN, Pandolfo M. Proprioceptors-enriched neuronal cultures from induced pluripotent stem cells from Friedreich ataxia patients show altered transcriptomic and proteomic profiles, abnormal neurite extension, and impaired electrophysiological properties. Brain Commun 2023; 5:fcad007. [PMID: 36865673 PMCID: PMC9972525 DOI: 10.1093/braincomms/fcad007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/28/2022] [Accepted: 01/14/2023] [Indexed: 01/19/2023] Open
Abstract
Friedreich ataxia is an autosomal recessive multisystem disorder with prominent neurological manifestations and cardiac involvement. The disease is caused by large GAA expansions in the first intron of the FXN gene, encoding the mitochondrial protein frataxin, resulting in downregulation of gene expression and reduced synthesis of frataxin. The selective loss of proprioceptive neurons is a hallmark of Friedreich ataxia, but the cause of the specific vulnerability of these cells is still unknown. We herein perform an in vitro characterization of human induced pluripotent stem cell-derived sensory neuronal cultures highly enriched for primary proprioceptive neurons. We employ neurons differentiated from healthy donors, Friedreich ataxia patients and Friedreich ataxia sibling isogenic control lines. The analysis of the transcriptomic and proteomic profile suggests an impairment of cytoskeleton organization at the growth cone, neurite extension and, at later stages of maturation, synaptic plasticity. Alterations in the spiking profile of tonic neurons are also observed at the electrophysiological analysis of mature neurons. Despite the reversal of the repressive epigenetic state at the FXN locus and the restoration of FXN expression, isogenic control neurons retain many features of Friedreich ataxia neurons. Our study suggests the existence of abnormalities affecting proprioceptors in Friedreich ataxia, particularly their ability to extend towards their targets and transmit proper synaptic signals. It also highlights the need for further investigations to better understand the mechanistic link between FXN silencing and proprioceptive degeneration in Friedreich ataxia.
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Affiliation(s)
| | | | - Myriam Rai
- Laboratory of Experimental Neurology, Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Céline Keime
- Institut de Génétique et de Biologie Moléculaire et Cellulaire UMR 7104 CNRS-UdS / INSERM U1258, Université de Strasbourg, 67404 Illkirch Cedex, Strasbourg, France
| | - Virginie Imbault
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - David Communi
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Hélène Puccio
- Institut de Génétique et de Biologie Moléculaire et Cellulaire UMR 7104 CNRS-UdS / INSERM U1258, Université de Strasbourg, 67404 Illkirch Cedex, Strasbourg, France,Institut NeuroMyoGene (INMG) UMR5310—INSERM U1217, Faculté de Médecine, Université Claude Bernard—Lyon I, 69008 Lyon, France
| | - Serge N Schiffmann
- Laboratory of Neurophysiology, ULB-Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Massimo Pandolfo
- Correspondence to: Massimo Pandolfo Department of Neurology and Neurosurgery McGill University, Montreal Neurological Institute 3801 University Street, Montreal, Quebec H3A 2B4, Canada E-mail:
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6
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Keita M, McIntyre K, Rodden LN, Schadt K, Lynch DR. Friedreich ataxia: clinical features and new developments. Neurodegener Dis Manag 2022; 12:267-283. [PMID: 35766110 PMCID: PMC9517959 DOI: 10.2217/nmt-2022-0011] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/15/2022] [Indexed: 11/21/2022] Open
Abstract
Friedreich's ataxia (FRDA), a neurodegenerative disease characterized by ataxia and other neurological features, affects 1 in 50,000-100,000 individuals in the USA. However, FRDA also includes cardiac, orthopedic and endocrine dysfunction, giving rise to many secondary disease characteristics. The multifaceted approach for clinical care has necessitated the development of disease-specific clinical care guidelines. New developments in FRDA include the advancement of clinical drug trials targeting the NRF2 pathway and frataxin restoration. Additionally, a novel understanding of gene silencing in FRDA, reflecting a variegated silencing pattern, will have applications to current and future therapeutic interventions. Finally, new perspectives on the neuroanatomy of FRDA and its developmental features will refine the time course and anatomical targeting of novel approaches.
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Affiliation(s)
- Medina Keita
- Departments of Pediatrics & Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kellie McIntyre
- Departments of Pediatrics & Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Layne N Rodden
- Departments of Pediatrics & Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kim Schadt
- Departments of Pediatrics & Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David R Lynch
- Departments of Pediatrics & Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Mercado-Ayón E, Warren N, Halawani S, Rodden LN, Ngaba L, Dong YN, Chang JC, Fonck C, Mavilio F, Lynch DR, Lin H. Cerebellar Pathology in an Inducible Mouse Model of Friedreich Ataxia. Front Neurosci 2022; 16:819569. [PMID: 35401081 PMCID: PMC8987918 DOI: 10.3389/fnins.2022.819569] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by deficiency of the mitochondrial protein frataxin. Lack of frataxin causes neuronal loss in various areas of the CNS and PNS. In particular, cerebellar neuropathology in FRDA patients includes loss of large principal neurons and synaptic terminals in the dentate nucleus (DN), and previous studies have demonstrated early synaptic deficits in the Knockin-Knockout mouse model of FRDA. However, the exact correlation of frataxin deficiency with cerebellar neuropathology remains unclear. Here we report that doxycycline-induced frataxin knockdown in a mouse model of FRDA (FRDAkd) leads to synaptic cerebellar degeneration that can be partially reversed by AAV8-mediated frataxin restoration. Loss of cerebellar Purkinje neurons and large DN principal neurons are observed in the FRDAkd mouse cerebellum. Levels of the climbing fiber-specific glutamatergic synaptic marker VGLUT2 decline starting at 4 weeks after dox induction, whereas levels of the parallel fiber-specific synaptic marker VGLUT1 are reduced by 18-weeks. These findings suggest initial selective degeneration of climbing fiber synapses followed by loss of parallel fiber synapses. The GABAergic synaptic marker GAD65 progressively declined during dox induction in FRDAkd mice, while GAD67 levels remained unaltered, suggesting specific roles for frataxin in maintaining cerebellar synaptic integrity and function during adulthood. Expression of frataxin following AAV8-mediated gene transfer partially restored VGLUT1/2 levels. Taken together, our findings show that frataxin knockdown leads to cerebellar degeneration in the FRDAkd mouse model, suggesting that frataxin helps maintain cerebellar structure and function.
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Affiliation(s)
- Elizabeth Mercado-Ayón
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Nathan Warren
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Sarah Halawani
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Layne N. Rodden
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Lucie Ngaba
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Yi Na Dong
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | | | - Carlos Fonck
- Audentes Therapeutics, San Francisco, CA, United States
| | - Fulvio Mavilio
- Audentes Therapeutics, San Francisco, CA, United States
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - David R. Lynch
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- *Correspondence: David R. Lynch, ;
| | - Hong Lin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Hong Lin,
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8
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Neuro-Ophthalmological Findings in Friedreich's Ataxia. J Pers Med 2021; 11:jpm11080708. [PMID: 34442352 PMCID: PMC8398238 DOI: 10.3390/jpm11080708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 07/08/2021] [Accepted: 07/21/2021] [Indexed: 12/17/2022] Open
Abstract
Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by a severe autosomal recessive genetic disorder of the central nervous (CNS) and peripheral nervous system (PNS), affecting children and young adults. Its onset is before 25 years of age, with mean ages of onset and death between 11 and 38 years, respectively. The incidence is 1 in 30,000–50,000 persons. It is caused, in 97% of cases, by a homozygous guanine-adenine-adenine (GAA) trinucleotide mutation in the first intron of the frataxin (FXN) gene on chromosome 9 (9q13–q1.1). The mutation of this gene causes a deficiency of frataxin, which induces an altered inflow of iron into the mitochondria, increasing the nervous system’s vulnerability to oxidative stress. The main clinical signs include spinocerebellar ataxia with sensory loss and disappearance of deep tendon reflexes, cerebellar dysarthria, cardiomyopathy, and scoliosis. Diabetes, hearing loss, and pes cavus may also occur, and although most patients with FRDA do not present with symptomatic visual impairment, 73% present with clinical neuro-ophthalmological alterations such as optic atrophy and altered eye movement, among others. This review provides a brief overview of the main aspects of FRDA and then focuses on the ocular involvement of this pathology and the possible use of retinal biomarkers.
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9
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Lynch DR, Schadt K, Kichula E, McCormack S, Lin KY. Friedreich Ataxia: Multidisciplinary Clinical Care. J Multidiscip Healthc 2021; 14:1645-1658. [PMID: 34234452 PMCID: PMC8253929 DOI: 10.2147/jmdh.s292945] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/04/2021] [Indexed: 12/17/2022] Open
Abstract
Friedreich ataxia (FRDA) is a multisystem disorder affecting 1 in 50,000-100,000 person in the United States. Traditionally viewed as a neurodegenerative disease, FRDA patients also develop cardiomyopathy, scoliosis, diabetes and other manifestation. Although it usually presents in childhood, it continues throughout life, thus requiring expertise from both pediatric and adult subspecialist in order to provide optimal management. The phenotype of FRDA is unique, giving rise to specific loss of neuronal pathways, a unique form of cardiomyopathy with early hypertrophy and later fibrosis, and diabetes incorporating components of both type I and type II disease. Vision loss, hearing loss, urinary dysfunction and depression also occur in FRDA. Many agents are reaching Phase III trials; if successful, these will provide a variety of new treatments for FRDA that will require many specialists who are not familiar with FRDA to provide clinical therapy. This review provides a summary of the diverse manifestation of FRDA, existing symptomatic therapies, and approaches for integrative care for future therapy in FRDA.
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Affiliation(s)
- David R Lynch
- Division of Neurology, Departments of Pediatrics and Neurology, Children’s Hospital of Philadelphia and the Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Kim Schadt
- Division of Neurology, Departments of Pediatrics and Neurology, Children’s Hospital of Philadelphia and the Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Elizabeth Kichula
- Division of Neurology, Departments of Pediatrics and Neurology, Children’s Hospital of Philadelphia and the Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Shana McCormack
- Division of Endocrinology, Department of Pediatrics, Children’s Hospital of Philadelphia and the Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Kimberly Y Lin
- Division of Cardiology, Department of Pediatrics, Children’s Hospital of Philadelphia and the Perelman School of Medicine, Philadelphia, PA, 19104, USA
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10
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Rummey C, Corben LA, Delatycki MB, Subramony SH, Bushara K, Gomez CM, Hoyle JC, Yoon G, Ravina B, Mathews KD, Wilmot G, Zesiewicz T, Perlman S, Farmer JM, Lynch DR. Psychometric properties of the Friedreich Ataxia Rating Scale. NEUROLOGY-GENETICS 2019; 5:371. [PMID: 32042904 PMCID: PMC6927357 DOI: 10.1212/nxg.0000000000000371] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/23/2019] [Indexed: 11/18/2022]
Abstract
Objective To investigate the psychometric properties of the Friedreich Ataxia Rating Scale neurologic examination (FARSn) and its subscores, as well as the influence of the modifications resulting in the now widely used modified FARS (mFARS) examination. Methods Based on cross-sectional FARS data from the FA–Clinical Outcome Measures cohort, we conducted correlation-based psychometric analyses to investigate the interplay of items and subscores within the FARSn/mFARS constructs. Results The results provide support for both the FARSn and the mFARS constructs, as well as individually for their upper limb and lower limb coordination components. The omission of the peripheral nervous system subscore (D) and 2 items of the bulbar subscore (A) in the mFARS strengthens the overall construct compared with the complete FARS. Conclusions A correlation-based psychometric analysis of the neurologic FARSn score justifies the overall validity of the scale. In addition, omission of items of limited functional significance as created in the mFARS improves the features of the measures. Such information is crucial to the ongoing application of the mFARS in natural history studies and clinical trials. Additional analyses of longitudinal changes will be necessary to fully ascertain its utility, especially in nonambulant patients.
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Affiliation(s)
- Christian Rummey
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Louise A Corben
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Martin B Delatycki
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - S H Subramony
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Khalaf Bushara
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Christopher M Gomez
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Joseph Chad Hoyle
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Grace Yoon
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Bernard Ravina
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Katherine D Mathews
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - George Wilmot
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Theresa Zesiewicz
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Susan Perlman
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - Jennifer M Farmer
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
| | - David R Lynch
- Clinical Data Science GmbH (C.R.), Basel, Switzerland; Bruce Lefroy Centre for Genetic Health Research (L.A.C., M.B.D.), Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics (L.A.C., M.B.D.), University of Melbourne, Parkville, Victoria, Australia; Department of Neurology (S.H.S.), McKnight Brain Institute, Room, Gainesville, FL; University of Minnesota (K.B.); University of Chicago (C.M.G.); Ohio State University (J.C.H.); Divisions of Neurology and Clinical and Metabolic Genetics (G.Y.), Department of Paediatrics, the Hospital for Sick Children, University of Toronto, Ontario, Canada Hospital; University of Rochester (B.R.); University of Iowa (K.D.M.); Emory University (G.W.); University of South Florida (T.Z.); Friedreich's Ataxia Research Alliance (S.P.), Downingtown, PA; and Division of Neurology (D.R.L.), Children's Hospital of Philadelphia
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11
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Indelicato E, Nachbauer W, Eigentler A, Rudzki D, Wanschitz J, Boesch S. Intraepidermal Nerve Fiber Density in Friedreich's Ataxia. J Neuropathol Exp Neurol 2019; 77:1137-1143. [PMID: 30358880 DOI: 10.1093/jnen/nly100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/27/2018] [Indexed: 01/11/2023] Open
Abstract
Friedreich's Ataxia (FRDA) is caused by a homozygous intronic GAA expansion in the FXN gene. FRDA affects primarily the peripheral nervous system (PNS) with cumulative evidence from postmortem studies and in vitro models suggesting a developmental component of its pathology. In the present study, we aimed at gaining further insight in the PNS involvement in FRDA by investigating small nerve fibers in vivo. For this purpose, we evaluated the intraepidermal nerve fiber (IENF) density in skin-biopsies of the lower leg and applied clinical assessments of small fiber function (painDETECT, quantitative sensory testing) in 17 FRDAs. Mean IENF density was significantly lower in FRDAs compared to controls (5.77 ± 4.68 vs 9.33 ± 1.41, p = 0.013). Clinically, cold detection threshold was decreased in FRDAs (FRDA = -3.47(-6.64; -3.14), controls = -1.71 (-3.43; -1.23), p = 0.001) while other measures of small fiber function such as warm and pain sensation thresholds did not differ from controls. Five patients had sensory complaints, but none was diagnosed with neuropathic pain at painDETECT. The degree of small fiber loss was markedly variable in our cohort and showed an inverse correlation with the GAA repeat length (R2 = 0.573, p = 0.001). Our findings support a genetically determined small fiber loss in FRDA.
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Affiliation(s)
| | | | - Andreas Eigentler
- Neurology Department, Innsbruck Medical University, Innsbruck, Austria
| | - Dagmar Rudzki
- Neurology Department, Innsbruck Medical University, Innsbruck, Austria
| | - Julia Wanschitz
- Neurology Department, Innsbruck Medical University, Innsbruck, Austria
| | - Sylvia Boesch
- Neurology Department, Innsbruck Medical University, Innsbruck, Austria
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12
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Boesch S, Indelicato E. Erythropoietin and Friedreich Ataxia: Time for a Reappraisal? Front Neurosci 2019; 13:386. [PMID: 31105516 PMCID: PMC6491891 DOI: 10.3389/fnins.2019.00386] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/04/2019] [Indexed: 12/24/2022] Open
Abstract
Friedreich ataxia (FRDA) is a rare neurological disorder due to deficiency of the mitochondrial protein frataxin. Frataxin deficiency results in impaired mitochondrial function and iron deposition in affected tissues. Erythropoietin (EPO) is a cytokine which was mostly known as a key regulator of erythropoiesis until cumulative evidence showed additional neurotrophic and neuroprotective properties. These features offered the rationale for advancement of EPO in clinical trials in different neurological disorders in the past years, including FRDA. Several mechanisms of action of EPO may be beneficial in FRDA. First of all, EPO exposure results in frataxin upregulation in vitro and in vivo. By promoting erythropoiesis, EPO influences iron metabolism and induces shifts in iron pool which may ameliorate conditions of free iron excess and iron accumulation. Furthermore, EPO signaling is crucial for mitochondrial gene activation and mitochondrial biogenesis. Up to date nine clinical trials investigated the effects of EPO and derivatives in FRDA. The majority of these studies had a proof-of-concept design. Considering the natural history of FRDA, all of them were too short in duration and not powered for clinical changes. However, these studies addressed significant issues in the treatment with EPO, such as (1) the challenge of the dose finding, (2) stability of frataxin up-regulation, (3) continuous versus intermittent stimulation with EPO/regimen, or (4) tissue changes after EPO exposure in humans in vivo (muscle biopsy, brain imaging). Despite several clinical trials in the past, no treatment is available for the treatment of FRDA. Current lines of research focus on gene therapy, frataxin replacement strategies and on regulation of key metabolic checkpoints such as NrF2. Due to potential crosstalk with all these mechanisms, interventions on the EPO pathway still represent a valuable research field. The recent development of small EPO mimetics which maintain cytoprotective properties without erythropoietic action may open a new era in EPO research for the treatment of FRDA.
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Affiliation(s)
- Sylvia Boesch
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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13
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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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14
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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; 97:589-609. [PMID: 30027898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cerebellar ataxias are a group of rare progressive neurodegenerative disorders with an average prevalence ranges from 4.8 to 13.8 in 100,000 individuals. The inherited disorders affect multiple members of the families, or a community that is endogamous or consanguineous. Presence of more than 3000 mutations in different genes with overlapping clinical symptoms, genetic anticipation and pleiotropy, as well as incomplete penetrance and variable expressivity due to modifiers pose challenges in genotype-phenotype correlation. Development of a diagnostic algorithm could reduce the time as well as cost in clinicogenetic diagnostics and also help in reducing the economic and social burden of the disease. In a unique research collaboration spanning over 20 years, we have been able to develop a paradigm for studying cerebellar ataxias in the Indian population which would also be relevant in other rare diseases. This has involved clinical and genetic analysis of thousands of families from diverse Indian populations. The extensive resource on ataxia has led to the development of a clinicogenetic algorithm for cost-effective screening of ataxia and a unique ataxia clinic in the tertiary referral centre in All India Institute of Medical Sciences. Utilizing a population polymorphism scanning approach, we have been able to dissect the mechanisms of repeat instability and expansion in many ataxias, and also identify founders, and trace the mutational histories in the Indian population. This provides information for genetic testing of at-risk as well as protected individuals and populations. To dissect uncharacterized cases which comprises more than 50% of the cases, we have explored the potential of next-generation sequencing technologies coupled with the extensive resource of baseline data generated in-house and other public domains. We have also developed a repository of patient-derived peripheral blood mononuclear cells, lymphoblastoid cell lines and neuronal lineages (derived from iPSCs) for ascribing functionality to novel genes/mutations. Through integrating these technologies, novel genes have been identified that has broadened the diagnostic panel, increased the diagnostic yield to over 75%, helped in ascribing pathogenicity to novel mutations and enabled understanding of disease mechanisms. It has also provided a platform for testing novel molecules for amelioration of pathophysiological phenotypes. This review through a perspective on CAs suggests a generic paradigm fromdiagnostics to therapeutic interventions for rare disorders in the context of heterogeneous Indian populations.
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Affiliation(s)
- Renu Kumari
- CSIR Institute of Genomics and Integrative Biology (CSIR-IGIB), Mathura Road, New Delhi 110 025, India. E-mail:
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15
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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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16
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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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17
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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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Benini M, Fortuni S, Condò I, Alfedi G, Malisan F, Toschi N, Serio D, Massaro DS, Arcuri G, Testi R, Rufini A. E3 Ligase RNF126 Directly Ubiquitinates Frataxin, Promoting Its Degradation: Identification of a Potential Therapeutic Target for Friedreich Ataxia. Cell Rep 2017; 18:2007-2017. [PMID: 28228265 PMCID: PMC5329121 DOI: 10.1016/j.celrep.2017.01.079] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 12/14/2016] [Accepted: 01/29/2017] [Indexed: 12/21/2022] Open
Abstract
Friedreich ataxia (FRDA) is a severe genetic neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin. To date, there is no therapy to treat this condition. The amount of residual frataxin critically affects the severity of the disease; thus, attempts to restore physiological frataxin levels are considered therapeutically relevant. Frataxin levels are controlled by the ubiquitin-proteasome system; therefore, inhibition of the frataxin E3 ligase may represent a strategy to achieve an increase in frataxin levels. Here, we report the identification of the RING E3 ligase RNF126 as the enzyme that specifically mediates frataxin ubiquitination and targets it for degradation. RNF126 interacts with frataxin and promotes its ubiquitination in a catalytic activity-dependent manner, both in vivo and in vitro. Most importantly, RNF126 depletion results in frataxin accumulation in cells derived from FRDA patients, highlighting the relevance of RNF126 as a new therapeutic target for Friedreich ataxia.
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Affiliation(s)
- Monica Benini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy; Fratagene Therapeutics Srl, Viale dei Campioni 8, 00144 Rome, Italy
| | - Silvia Fortuni
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy
| | - Ivano Condò
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy
| | - Giulia Alfedi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy
| | - Florence Malisan
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy
| | - Nicola Toschi
- Medical Physics Section, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA 02115, USA
| | - Dario Serio
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy; Fratagene Therapeutics Srl, Viale dei Campioni 8, 00144 Rome, Italy
| | - Damiano Sergio Massaro
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy
| | - Gaetano Arcuri
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy
| | - Roberto Testi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy; Fratagene Therapeutics Srl, Viale dei Campioni 8, 00144 Rome, Italy
| | - Alessandra Rufini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, 00133 Rome, Italy; Fratagene Therapeutics Srl, Viale dei Campioni 8, 00144 Rome, Italy.
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20
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Dantham S, Srivastava AK, Gulati S, Rajeswari MR. Plasma circulating cell-free mitochondrial DNA in the assessment of Friedreich's ataxia. J Neurol Sci 2016; 365:82-8. [PMID: 27206881 DOI: 10.1016/j.jns.2016.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/14/2016] [Accepted: 04/11/2016] [Indexed: 12/11/2022]
Abstract
Friedreich's ataxia (FRDA) is one of the most devastating childhood onset neurodegenerative disease affecting multiple organs in the course of progression. FRDA is associated with mitochondrial dysfunction due to deficit in a nuclear encoded mitochondrial protein, frataxin. Identification of disease-specific biomarker for monitoring the severity remains to be a challenging topic. This study was aimed to identify whether circulating cell-free nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) in blood plasma can be a potential biomarker for FRDA. Clinical information was assessed using International Cooperative Ataxia Rating Scale and the disease was confirmed using Long-range PCR for GAA repeat expansion within the gene encoding frataxin. The frataxin expression was measured using Western blot. Plasma nDNA and mtDNA levels were quantified by Multiplex real-time PCR. The major observation is that the levels of nDNA found to be increased, whereas mtDNA levels were reduced significantly in the plasma of FRDA patients (n=21) as compared to healthy controls (n=21). Further, plasma mtDNA levels showed high sensitivity (90%) and specificity (76%) in distinguishing from healthy controls with optimal cutoff indicated at 4.1×10(5)GE/mL. Interestingly, a small group of follow-up patients (n=9) on intervention with, a nutrient supplement, omega-3 fatty acid (a known enhancer of mitochondrial metabolism) displayed a significant improvement in the levels of plasma mtDNA, supporting our hypothesis that plasma mtDNA can be a potential monitoring or prognosis biomarker for FRDA.
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Affiliation(s)
- Subrahamanyam Dantham
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India.
| | - Achal K Srivastava
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
| | - Sheffali Gulati
- Paediatrics Neurology, All India Institute of Medical Sciences, New Delhi, India.
| | - Moganty R Rajeswari
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India.
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21
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Katsu-Jiménez Y, Loría F, Corona JC, Díaz-Nido J. Gene Transfer of Brain-derived Neurotrophic Factor (BDNF) Prevents Neurodegeneration Triggered by FXN Deficiency. Mol Ther 2016; 24:877-89. [PMID: 26849417 PMCID: PMC4881769 DOI: 10.1038/mt.2016.32] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 01/21/2016] [Indexed: 02/07/2023] Open
Abstract
Friedreich's ataxia is a predominantly neurodegenerative disease caused by recessive mutations that produce a deficiency of frataxin (FXN). Here, we have used a herpesviral amplicon vector carrying a gene encoding for brain-derived neurotrophic factor (BDNF) to drive its overexpression in neuronal cells and test for its effect on FXN-deficient neurons both in culture and in the mouse cerebellum in vivo. Gene transfer of BDNF to primary cultures of mouse neurons prevents the apoptosis which is triggered by the knockdown of FXN gene expression. This neuroprotective effect of BDNF is also observed in vivo in a viral vector-based knockdown mouse cerebellar model. The injection of a lentiviral vector carrying a minigene encoding for a FXN-specific short hairpin ribonucleic acid (shRNA) into the mouse cerebellar cortex triggers a FXN deficit which is accompanied by significant apoptosis of granule neurons as well as loss of calbindin in Purkinje cells. These pathological changes are accompanied by a loss of motor coordination of mice as assayed by the rota-rod test. Coinjection of a herpesviral vector encoding for BDNF efficiently prevents both the development of cerebellar neuropathology and the ataxic phenotype. These data demonstrate the potential therapeutic usefulness of neurotrophins like BDNF to protect FXN-deficient neurons from degeneration.
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Affiliation(s)
- Yurika Katsu-Jiménez
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Instituto de Investigaciones Sanitarias Hospital Puerta de Hierro-Majadahonda (IDIPHIM), Madrid, Spain
| | - Frida Loría
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Instituto de Investigaciones Sanitarias Hospital Puerta de Hierro-Majadahonda (IDIPHIM), Madrid, Spain
| | - Juan Carlos Corona
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Instituto de Investigaciones Sanitarias Hospital Puerta de Hierro-Majadahonda (IDIPHIM), Madrid, Spain
- Current address: Hospital Infantil de México “Federico Gómez”, México, D.F., México
| | - Javier Díaz-Nido
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Instituto de Investigaciones Sanitarias Hospital Puerta de Hierro-Majadahonda (IDIPHIM), Madrid, Spain
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22
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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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23
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Pérez-Luz S, Gimenez-Cassina A, Fernández-Frías I, Wade-Martins R, Díaz-Nido J. Delivery of the 135 kb human frataxin genomic DNA locus gives rise to different frataxin isoforms. Genomics 2015; 106:76-82. [PMID: 26027909 DOI: 10.1016/j.ygeno.2015.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 05/21/2015] [Accepted: 05/23/2015] [Indexed: 11/25/2022]
Abstract
Friedreich's ataxia (FRDA) is the most common form of hereditary ataxia caused by recessive mutations in the FXN gene. Recent results have indicated the presence of different frataxin isoforms due to alternative gene expression mechanisms. Our previous studies demonstrated the advantages of using high-capacity herpes simplex virus type 1 (HSV-1) amplicon vectors containing the entire FXN genomic locus (iBAC-FXN) as a gene-delivery vehicle capable of ensuring physiologically-regulated and long-term persistence. Here we describe how expression from the 135 kb human FXN genomic locus produces the three frataxin isoforms both in cultured neuronal cells and also in vivo. Moreover, we also observed the correct expression of these frataxin isoforms in patient-derived cells after delivery of the iBAC-FXN. These results lend further support to the potential use of HSV-1 vectors containing entire genomic loci whose expression is mediated by complex transcriptional and posttranscriptional mechanisms for gene therapy applications.
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Affiliation(s)
- S Pérez-Luz
- Departamento Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigación Sanitaria Puerta de Hierro-Majadahonda, Spain
| | | | - I Fernández-Frías
- Departamento Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigación Sanitaria Puerta de Hierro-Majadahonda, Spain
| | | | - J Díaz-Nido
- Departamento Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, 28049 Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Spain; Instituto de Investigación Sanitaria Puerta de Hierro-Majadahonda, Spain.
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24
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Kolnagou A, Kontoghiorghe CN, Kontoghiorghes GJ. Transition of Thalassaemia and Friedreich ataxia from fatal to chronic diseases. World J Methodol 2014; 4:197-218. [PMID: 25541601 PMCID: PMC4274580 DOI: 10.5662/wjm.v4.i4.197] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 07/22/2014] [Accepted: 10/16/2014] [Indexed: 02/06/2023] Open
Abstract
Thalassaemia major (TM) and Friedreich’s ataxia (FA) are autosomal recessive inherited diseases related to the proteins haemoglobin and frataxin respectively. In both diseases abnormalities in iron metabolism is the main cause of iron toxicity leading to increased morbidity and mortality. Major efforts are directed towards the prevention of these diseases and also in their treatment using iron chelation therapy. Both TM and FA are endemic in Cyprus, where the frequency per total population of asymptomatic heterozygote carriers and patients is the highest worldwide. Cyprus has been a pioneering nation in preventing and nearly eliminating the birth of TM and FA patients by introducing an organized health structure, including prenatal and antenatal diagnosis. Effective iron chelation therapy, improved diagnostic methods and transfusion techniques as well as supportive therapy from other clinical specializations have improved the survival and quality of life of TM patients. Despite the tiresome clinical management regimes many TM patients are successful in their professional lives, have families with children and some are now living well into their fifties. The introduction of deferiprone led to the elimination of cardiac failure induced by iron overload toxicity, which was the major cause of mortality in TM. Effective combinations of deferiprone with deferoxamine in TM patients caused the fall of body iron to normal physiological ranges. In FA different mechanisms of iron metabolism and toxicity apply to that of TM, which can be targeted with specific iron chelation protocols. Preliminary findings from the introduction of deferiprone in FA patients have increased the hopes for improved and effective therapy in this untreatable condition. New and personalised treatments are proposed in TM and FA. Overall, advances in treatments and in particular of chelation therapy using deferiprone are transforming TM and FA from fatal to chronic conditions. The paradigm of Cyprus in the prevention and treatment of TM can be used for application worldwide.
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25
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Strawser CJ, Schadt KA, Lynch DR. Therapeutic approaches for the treatment of Friedreich’s ataxia. Expert Rev Neurother 2014; 14:949-57. [DOI: 10.1586/14737175.2014.939173] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Human platelets as a platform to monitor metabolic biomarkers using stable isotopes and LC-MS. Bioanalysis 2014; 5:3009-21. [PMID: 24320127 DOI: 10.4155/bio.13.269] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Intracellular metabolites such as CoA thioesters are modulated in a number of clinical settings. Their accurate measurement from surrogate tissues such as platelets may provide additional information to current serum and urinary biomarkers. METHODS Freshly isolated platelets from healthy volunteers were treated with rotenone, propionate or isotopically labeled metabolic tracers. Using a recently developed LC-MS-based methodology, absolute changes in short-chain acyl-CoA thioesters were monitored, as well as relative metabolic labeling using isotopomer distribution analysis. RESULTS Consistent with in vitro experiments, isolated platelets treated with rotenone showed decreased intracellular succinyl-CoA and increased β-hydroxybutyryl-CoA, while propionate treatment resulted in increased propionyl-CoA. In addition, isotopomers of the CoAs were readily detected in platelets treated with the [(13)C]- or [(13)C(15)N]-labeled metabolic precursors. CONCLUSION Here, we show that human platelets can provide a powerful ex vivo challenge platform with potential clinical diagnostic and biomarker discovery applications.
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Eigentler A, Boesch S, Schneider R, Dechant G, Nat R. Induced pluripotent stem cells from friedreich ataxia patients fail to upregulate frataxin during in vitro differentiation to peripheral sensory neurons. Stem Cells Dev 2013; 22:3271-82. [PMID: 23879205 DOI: 10.1089/scd.2013.0126] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The value of human disease models, which are based on induced pluripotent stem cells (iPSCs), depends on the capacity to generate specifically those cell types affected by pathology. We describe a new iPSC-based model of Friedreich ataxia (FRDA), an autosomal recessive neurodegenerative disorder with an intronic GAA repeat expansion in the frataxin gene. As the peripheral sensory neurons are particularly susceptible to neurodegeneration in FRDA, we applied a development-based differentiation protocol to generate specifically these cells. FRDA and control iPSC lines were efficiently differentiated toward neural crest progenitors and peripheral sensory neurons. The progress of the cell lines through discrete steps of in vitro differentiation was closely monitored by expression levels of key markers for peripheral neural development. Since it had been suggested that FRDA pathology might start early during ontogenesis, we investigated frataxin expression in our development-related model. A pronounced frataxin deficit was found in FRDA iPSCs and neural crest cells compared to controls. Whereas we identified an upregulation of frataxin expression during sensory specification for control cells, this increase was not observed for FRDA peripheral sensory neurons. This early failure, aggravating frataxin deficiency in a specifically vulnerable human cell population, indicates a developmental component in FRDA.
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Affiliation(s)
- Andreas Eigentler
- 1 Department of Neurology, Innsbruck Medical University , Innsbruck, Austria
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28
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Bayot A, Reichman S, Lebon S, Csaba Z, Aubry L, Sterkers G, Husson I, Rak M, Rustin P. Cis-silencing of PIP5K1B evidenced in Friedreich's ataxia patient cells results in cytoskeleton anomalies. Hum Mol Genet 2013; 22:2894-904. [PMID: 23552101 DOI: 10.1093/hmg/ddt144] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Friedreich's ataxia (FRDA) is a progressive neurodegenerative disease characterized by ataxia, variously associating heart disease, diabetes mellitus and/or glucose intolerance. It results from intronic expansion of GAA triplet repeats at the FXN locus. Homozygous expansions cause silencing of the FXN gene and subsequent decreased expression of the encoded mitochondrial frataxin. Detailed analyses in fibroblasts and neuronal tissues from FRDA patients have revealed profound cytoskeleton anomalies. So far, however, the molecular mechanism underlying these cytoskeleton defects remains unknown. We show here that gene silencing spreads in cis over the PIP5K1B gene in cells from FRDA patients (circulating lymphocytes and primary fibroblasts), correlating with expanded GAA repeat size. PIP5K1B encodes phosphatidylinositol 4-phosphate 5-kinase β type I (pip5k1β), an enzyme functionally linked to actin cytoskeleton dynamics that phosphorylates phosphatidylinositol 4-phosphate [PI(4)P] to generate phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. Accordingly, loss of pip5k1β function in FRDA cells was accompanied by decreased PI(4,5)P2 levels and was shown instrumental for destabilization of the actin network and delayed cell spreading. Knockdown of PIP5K1B in control fibroblasts using shRNA reproduced abnormal actin cytoskeleton remodeling, whereas over-expression of PIP5K1B, but not FXN, suppressed this phenotype in FRDA cells. In addition to provide new insights into the consequences of the FXN gene expansion, these findings raise the question whether PIP5K1B silencing may contribute to the variable manifestation of this complex disease.
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Affiliation(s)
- Aurélien Bayot
- Hôpital Robert Debré, INSERM UMR 676 Faculté de Médecine Denis Diderot, Université Paris 7, 75019 Paris, France.
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