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Vancheri C, Quatrana A, Morini E, Mariotti C, Mongelli A, Fichera M, Rufini A, Condò I, Testi R, Novelli G, Malisan F, Amati F. An RNA-seq study in Friedreich ataxia patients identified hsa-miR-148a-3p as a putative prognostic biomarker of the disease. Hum Genomics 2024; 18:50. [PMID: 38778374 PMCID: PMC11110315 DOI: 10.1186/s40246-024-00602-y] [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: 10/11/2023] [Accepted: 03/26/2024] [Indexed: 05/25/2024] Open
Abstract
Friedreich ataxia (FRDA) is a life-threatening hereditary ataxia; its incidence is 1:50,000 individuals in the Caucasian population. A unique therapeutic drug for FRDA, the antioxidant Omaveloxolone, has been recently approved by the US Food and Drug Administration (FDA). FRDA is a multi-systemic neurodegenerative disease; in addition to a progressive neurodegeneration, FRDA is characterized by hypertrophic cardiomyopathy, diabetes mellitus and musculoskeletal deformities. Cardiomyopathy is the predominant cause of premature death. The onset of FRDA typically occurs between the ages of 5 and 15. Given the complexity and heterogeneity of clinical features and the variability of their onset, the identification of biomarkers capable of assessing disease progression and monitoring the efficacy of treatments is essential to facilitate decision making in clinical practice. We conducted an RNA-seq analysis in peripheral blood mononuclear cells from FRDA patients and healthy donors, identifying a signature of small non-coding RNAs (sncRNAs) capable of distinguishing healthy individuals from the majority of FRDA patients. Among the differentially expressed sncRNAs, microRNAs are a class of small non-coding endogenous RNAs that regulate posttranscriptional silencing of target genes. In FRDA plasma samples, hsa-miR-148a-3p resulted significantly upregulated. The analysis of the Receiver Operating Characteristic (ROC) curve, combining the circulating expression levels of hsa-miR-148a-3p and hsa-miR-223-3p (previously identified by our group), revealed an Area Under the Curve (AUC) of 0.86 (95%, Confidence Interval 0.77-0.95; p-value < 0.0001). An in silico prediction analysis indicated that the IL6ST gene, an interesting marker of neuroinflammation in FRDA, is a common target gene of both miRNAs. Our findings support the evaluation of combined expression levels of different circulating miRNAs as potent epi-biomarkers in FRDA. Moreover, we found hsa-miR-148a-3p significantly over-expressed in Intermediate and Late-Onset Friedreich Ataxia patients' group (IOG and LOG, respectively) compared to healthy individuals, indicating it as a putative prognostic biomarker in this pathology.
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Affiliation(s)
- Chiara Vancheri
- Department of Biomedicine and Prevention, Genetics Unit, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
| | - Andrea Quatrana
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
- Muscular and Neurodegenerative Diseases Laboratory, Bambino Gesù, Children's Hospital, IRCCS, Rome, Italy
| | - Elena Morini
- Department of Biomedicine and Prevention, Genetics Unit, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
| | - Caterina Mariotti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, 20133, Italy
| | - Alessia Mongelli
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, 20133, Italy
| | - Mario Fichera
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, 20133, Italy
| | - Alessandra Rufini
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
- Saint Camillus International University of Health and Medical Sciences, Rome, 00131, Italy
| | - Ivano Condò
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
| | - Roberto Testi
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
| | - Giuseppe Novelli
- Department of Biomedicine and Prevention, Genetics Unit, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy
- Neuromed Institute, IRCCS, Pozzilli, 86077, Italy
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Florence Malisan
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy.
| | - Francesca Amati
- Department of Biomedicine and Prevention, Genetics Unit, Tor Vergata University of Rome, Via Montpellier 1, Rome, 00133, Italy.
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Cheng Z, Xue K, Xiong C, Zheng Z, Li J, Qiao X. MRPS16 promotes lung adenocarcinoma growth via the PI3K/AKT/Frataxin signalling axis. J Cell Mol Med 2024; 28:e18166. [PMID: 38506080 PMCID: PMC10951875 DOI: 10.1111/jcmm.18166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 12/26/2023] [Accepted: 01/24/2024] [Indexed: 03/21/2024] Open
Abstract
Although MRPS16 is involved in cancer development, its mechanisms in developing LAUD remain unclear. Herein, qRT-PCR, WB and IHC were utilized for evaluating MRPS16 expression levels, while functional assays besides animal experiments were performed to measure MRPS16 effect on LAUD progression. Using WB, the MRPS16 effect on PI3K/AKT/Frataxin signalling pathway was tested. According to our study, MRPS16 was upregulated in LAUD and was correlated to the advanced TNM stage as well as poor clinical outcomes, which represent an independent prognostic factor. Based on functional assays, MRPS16 is involved in promoting LAUD growth, migration and invasion, which was validated further in subsequent analyses through PI3K/AKT/Frataxin pathway activation. Moreover, MRPS16-knockdown-mediated Frataxin overexpression was shown to restore the reduction in tumour cells proliferation, migration and invasion. Our results revealed that MRPS16 caused an aggressive phenotype to LAUD and was a poor prognosticator; thus, targeting MRPS16 may be effectual in LAUD treatment.
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Affiliation(s)
- Zaixing Cheng
- Department of Thoracic SurgeryUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanHubeiChina
| | - Kaming Xue
- Department of Traditional Chinese MedicineUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanHubeiChina
| | - Cui Xiong
- Department of EndocrinologyUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanHubeiChina
| | - Zhikun Zheng
- Department of Thoracic SurgeryUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanHubeiChina
| | - Jinsong Li
- Department of Thoracic SurgeryUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanHubeiChina
| | - Xinwei Qiao
- Department of Thoracic SurgeryUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanHubeiChina
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3
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Luffarelli R, Panarello L, Quatrana A, Tiano F, Fortuni S, Rufini A, Malisan F, Testi R, Condò I. Interferon Gamma Enhances Cytoprotective Pathways via Nrf2 and MnSOD Induction in Friedreich's Ataxia Cells. Int J Mol Sci 2023; 24:12687. [PMID: 37628866 PMCID: PMC10454386 DOI: 10.3390/ijms241612687] [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: 06/08/2023] [Revised: 07/27/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Friedreich's ataxia (FRDA) is a rare monogenic disease characterized by multisystem, slowly progressive degeneration. Because of the genetic defect in a non-coding region of FXN gene, FRDA cells exhibit severe deficit of frataxin protein levels. Hence, FRDA pathophysiology is characterized by a plethora of metabolic disruptions related to iron metabolism, mitochondrial homeostasis and oxidative stress. Importantly, an impairment of the antioxidant defences exacerbates the oxidative damage. This appears closely associated with the disablement of key antioxidant proteins, such as the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and the mitochondrial superoxide dismutase (MnSOD). The cytokine interferon gamma (IFN-γ) has been shown to increase frataxin expression in FRDA cells and to improve functional deficits in FRDA mice. Currently, IFN-γ represents a potential therapy under clinical evaluation in FRDA patients. Here, we show that IFN-γ induces a rapid expression of Nrf2 and MnSOD in different cell types, including FRDA patient-derived fibroblasts. Our data indicate that IFN-γ signals two separate pathways to enhance Nrf2 and MnSOD levels in FRDA fibroblasts. MnSOD expression increased through an early transcriptional regulation, whereas the levels of Nrf2 are induced by a post-transcriptional mechanism. We demonstrate that the treatment of FRDA fibroblasts with IFN-γ stimulates a non-canonical Nrf2 activation pathway through p21 and potentiates antioxidant responses under exposure to hydrogen peroxide. Moreover, IFN-γ significantly reduced the sensitivity to hydrogen peroxide-induced cell death in FRDA fibroblasts. Collectively, these results indicate the presence of multiple pathways triggered by IFN-γ with therapeutic relevance to FRDA.
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Affiliation(s)
- Riccardo Luffarelli
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Luca Panarello
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Andrea Quatrana
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Francesca Tiano
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Silvia Fortuni
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Alessandra Rufini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
- Departmental Faculty of Medicine and Surgery, Saint Camillus International University of Health and Medical Sciences, 00131 Rome, Italy
| | - Florence Malisan
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Roberto Testi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
| | - Ivano Condò
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (R.L.); (L.P.); (A.Q.); (F.T.); (S.F.); (A.R.); (F.M.); (R.T.)
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Rodden LN, Gilliam KM, Lam C, Rojsajjakul T, Mesaros C, Dionisi C, Pook M, Pandolfo M, Lynch DR, Blair IA, Bidichandani SI. DNA methylation in Friedreich ataxia silences expression of frataxin isoform E. Sci Rep 2022; 12:5031. [PMID: 35322126 PMCID: PMC8943190 DOI: 10.1038/s41598-022-09002-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 03/14/2022] [Indexed: 11/15/2022] Open
Abstract
Epigenetic silencing in Friedreich ataxia (FRDA), induced by an expanded GAA triplet-repeat in intron 1 of the FXN gene, results in deficiency of the mitochondrial protein, frataxin. A lesser known extramitochondrial isoform of frataxin detected in erythrocytes, frataxin-E, is encoded via an alternate transcript (FXN-E) originating in intron 1 that lacks a mitochondrial targeting sequence. We show that FXN-E is deficient in FRDA, including in patient-derived cell lines, iPS-derived proprioceptive neurons, and tissues from a humanized mouse model. In a series of FRDA patients, deficiency of frataxin-E protein correlated with the length of the expanded GAA triplet-repeat, and with repeat-induced DNA hypermethylation that occurs in close proximity to the intronic origin of FXN-E. CRISPR-induced epimodification to mimic DNA hypermethylation seen in FRDA reproduced FXN-E transcriptional deficiency. Deficiency of frataxin E is a consequence of FRDA-specific epigenetic silencing, and therapeutic strategies may need to address this deficiency.
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Affiliation(s)
- Layne N Rodden
- Department of Pediatrics, University of Oklahoma Health Sciences Center, OU Children's Physician Building, Suite 12100, 1200 Children's Avenue, Oklahoma City, OK, 73104, USA
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kaitlyn M Gilliam
- Department of Pediatrics, University of Oklahoma Health Sciences Center, OU Children's Physician Building, Suite 12100, 1200 Children's Avenue, Oklahoma City, OK, 73104, USA
| | - Christina Lam
- Department of Pediatrics, University of Oklahoma Health Sciences Center, OU Children's Physician Building, Suite 12100, 1200 Children's Avenue, Oklahoma City, OK, 73104, USA
| | - Teerapat Rojsajjakul
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Clementina Mesaros
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Mark Pook
- Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - Massimo Pandolfo
- Université Libre de Bruxelles (ULB), Brussels, Belgium
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - David R Lynch
- Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ian A Blair
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sanjay I Bidichandani
- Department of Pediatrics, University of Oklahoma Health Sciences Center, OU Children's Physician Building, Suite 12100, 1200 Children's Avenue, Oklahoma City, OK, 73104, USA.
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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5
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Monfort B, Want K, Gervason S, D’Autréaux B. Recent Advances in the Elucidation of Frataxin Biochemical Function Open Novel Perspectives for the Treatment of Friedreich’s Ataxia. Front Neurosci 2022; 16:838335. [PMID: 35310092 PMCID: PMC8924461 DOI: 10.3389/fnins.2022.838335] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/28/2022] [Indexed: 12/25/2022] Open
Abstract
Friedreich’s ataxia (FRDA) is the most prevalent autosomic recessive ataxia and is associated with a severe cardiac hypertrophy and less frequently diabetes. It is caused by mutations in the gene encoding frataxin (FXN), a small mitochondrial protein. The primary consequence is a defective expression of FXN, with basal protein levels decreased by 70–98%, which foremost affects the cerebellum, dorsal root ganglia, heart and liver. FXN is a mitochondrial protein involved in iron metabolism but its exact function has remained elusive and highly debated since its discovery. At the cellular level, FRDA is characterized by a general deficit in the biosynthesis of iron-sulfur (Fe-S) clusters and heme, iron accumulation and deposition in mitochondria, and sensitivity to oxidative stress. Based on these phenotypes and the proposed ability of FXN to bind iron, a role as an iron storage protein providing iron for Fe-S cluster and heme biosynthesis was initially proposed. However, this model was challenged by several other studies and it is now widely accepted that FXN functions primarily in Fe-S cluster biosynthesis, with iron accumulation, heme deficiency and oxidative stress sensitivity appearing later on as secondary defects. Nonetheless, the biochemical function of FXN in Fe-S cluster biosynthesis is still debated. Several roles have been proposed for FXN: iron chaperone, gate-keeper of detrimental Fe-S cluster biosynthesis, sulfide production stimulator and sulfur transfer accelerator. A picture is now emerging which points toward a unique function of FXN as an accelerator of a key step of sulfur transfer between two components of the Fe-S cluster biosynthetic complex. These findings should foster the development of new strategies for the treatment of FRDA. We will review here the latest discoveries on the biochemical function of frataxin and the implication for a potential therapeutic treatment of FRDA.
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Rufini A, Malisan F, Condò I, Testi R. Drug Repositioning in Friedreich Ataxia. Front Neurosci 2022; 16:814445. [PMID: 35221903 PMCID: PMC8863941 DOI: 10.3389/fnins.2022.814445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/07/2022] [Indexed: 12/14/2022] Open
Abstract
Friedreich ataxia is a rare neurodegenerative disorder caused by insufficient levels of the essential mitochondrial protein frataxin. It is a severely debilitating disease that significantly impacts the quality of life of affected patients and reduces their life expectancy, however, an adequate cure is not yet available for patients. Frataxin function, although not thoroughly elucidated, is associated with assembly of iron-sulfur cluster and iron metabolism, therefore insufficient frataxin levels lead to reduced activity of many mitochondrial enzymes involved in the electron transport chain, impaired mitochondrial metabolism, reduced ATP production and inefficient anti-oxidant response. As a consequence, neurons progressively die and patients progressively lose their ability to coordinate movement and perform daily activities. Therapeutic strategies aim at restoring sufficient frataxin levels or at correcting some of the downstream consequences of frataxin deficiency. However, the classical pathways of drug discovery are challenging, require a significant amount of resources and time to reach the final approval, and present a high failure rate. Drug repositioning represents a viable alternative to boost the identification of a therapy, particularly for rare diseases where resources are often limited. In this review we will describe recent efforts aimed at the identification of a therapy for Friedreich ataxia through drug repositioning, and discuss the limitation of such strategies.
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Affiliation(s)
- Alessandra Rufini
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
- Fratagene Therapeutics, Rome, Italy
- Saint Camillus International University of Health and Medical Sciences, Rome, Italy
- *Correspondence: Alessandra Rufini,
| | - Florence Malisan
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
| | - Ivano Condò
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
| | - Roberto Testi
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
- Fratagene Therapeutics, Rome, Italy
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SINEUPs: a novel toolbox for RNA therapeutics. Essays Biochem 2021; 65:775-789. [PMID: 34623427 PMCID: PMC8564737 DOI: 10.1042/ebc20200114] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/22/2021] [Accepted: 08/23/2021] [Indexed: 12/17/2022]
Abstract
RNA molecules have emerged as a new class of promising therapeutics to expand the range of druggable targets in the genome. In addition to ‘canonical’ protein-coding mRNAs, the emerging richness of sense and antisense long non-coding RNAs (lncRNAs) provides a new reservoir of molecular tools for RNA-based drugs. LncRNAs are composed of modular structural domains with specific activities involving the recruitment of protein cofactors or directly interacting with nucleic acids. A single therapeutic RNA transcript can then be assembled combining domains with defined secondary structures and functions, and antisense sequences specific for the RNA/DNA target of interest. As the first representative molecules of this new pharmacology, we have identified SINEUPs, a new functional class of natural antisense lncRNAs that increase the translation of partially overlapping mRNAs. Their activity is based on the combination of two domains: an embedded mouse inverted SINEB2 element that enhances mRNA translation (effector domain) and an overlapping antisense region that provides specificity for the target sense transcript (binding domain). By genetic engineering, synthetic SINEUPs can potentially target any mRNA of interest increasing translation and therefore the endogenous level of the encoded protein. In this review, we describe the state-of-the-art knowledge of SINEUPs and discuss recent publications showing their potential application in diseases where a physiological increase of endogenous protein expression can be therapeutic.
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Frataxins Emerge as New Players of the Intracellular Antioxidant Machinery. Antioxidants (Basel) 2021; 10:antiox10020315. [PMID: 33672495 PMCID: PMC7923443 DOI: 10.3390/antiox10020315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/30/2022] Open
Abstract
Frataxin is a mitochondrial protein which deficiency causes Friedreich's ataxia, a cardio-neurodegenerative disease. The lack of frataxin induces the dysregulation of mitochondrial iron homeostasis and oxidative stress, which finally causes the neuronal death. The mechanism through which frataxin regulates the oxidative stress balance is rather complex and poorly understood. While the absence of human (Hfra) and yeast (Yfh1) frataxins turn out cells sensitive to oxidative stress, this does not occur when the frataxin gene is knocked-out in E. coli. To better understand the biological roles of Hfra and Yfh1 as endogenous antioxidants, we have studied their ability to inhibit the formation of reactive oxygen species (ROS) from Cu2+- and Fe3+-catalyzed degradation of ascorbic acid. Both proteins drastically reduce the formation of ROS, and during this process they are not oxidized. In addition, we have also demonstrated that merely the presence of Yfh1 or Hfra is enough to protect a highly oxidation-prone protein such as α-synuclein. This unspecific intervention (without a direct binding) suggests that frataxins could act as a shield to prevent the oxidation of a broad set of intracellular proteins, and reinforces that idea that frataxin can be used to prevent neurological pathologies linked to an enhanced oxidative stress.
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Agrò M, Díaz-Nido J. Effect of Mitochondrial and Cytosolic FXN Isoform Expression on Mitochondrial Dynamics and Metabolism. Int J Mol Sci 2020; 21:E8251. [PMID: 33158039 PMCID: PMC7662637 DOI: 10.3390/ijms21218251] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 10/27/2020] [Accepted: 11/02/2020] [Indexed: 02/07/2023] Open
Abstract
Friedreich's ataxia (FRDA) is a neurodegenerative disease caused by recessive mutations in the frataxin gene that lead to a deficiency of the mitochondrial frataxin (FXN) protein. Alternative forms of frataxin have been described, with different cellular localization and tissue distribution, including a cerebellum-specific cytosolic isoform called FXN II. Here, we explored the functional roles of FXN II in comparison to the mitochondrial FXN I isoform, highlighting the existence of potential cross-talk between cellular compartments. To achieve this, we transduced two human cell lines of patient and healthy subjects with lentiviral vectors overexpressing the mitochondrial or the cytosolic FXN isoforms and studied their effect on the mitochondrial network and metabolism. We confirmed the cytosolic localization of FXN isoform II in our in vitro models. Interestingly, both cytosolic and mitochondrial isoforms have an effect on mitochondrial dynamics, affecting different parameters. Accordingly, increases of mitochondrial respiration were detected after transduction with FXN I or FXN II in both cellular models. Together, these results point to the existence of a potential cross-talk mechanism between the cytosol and mitochondria, mediated by FXN isoforms. A more thorough knowledge of the mechanisms of action behind the extra-mitochondrial FXN II isoform could prove useful in unraveling FRDA physiopathology.
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Affiliation(s)
| | - Javier Díaz-Nido
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM) and Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera, 1, 28049 Madrid, Spain;
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Weng L, Laboureur L, Wang Q, Guo L, Xu P, Gottlieb L, Lynch DR, Mesaros C, Blair IA. Extra-mitochondrial mouse frataxin and its implications for mouse models of Friedreich's ataxia. Sci Rep 2020; 10:15788. [PMID: 32978498 PMCID: PMC7519113 DOI: 10.1038/s41598-020-72884-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 08/28/2020] [Indexed: 01/04/2023] Open
Abstract
Mature frataxin is essential for the assembly of iron-sulfur cluster proteins including a number of mitochondrial enzymes. Reduced levels of mature frataxin (81-20) in human subjects caused by the genetic disease Friedreich's ataxia results in decreased mitochondrial function, neurodegeneration, and cardiomyopathy. Numerous studies of mitochondrial dysfunction have been conducted using mouse models of frataxin deficiency. However, mouse frataxin that is reduced in these models, is assumed to be mature frataxin (78-207) by analogy with human mature frataxin (81-210). Using immunoaffinity purification coupled with liquid chromatography-high resolution tandem mass spectrometry, we have discovered that mature frataxin in mouse heart (77%), brain (86%), and liver (47%) is predominantly a 129-amino acid truncated mature frataxin (79-207) in which the N-terminal lysine residue has been lost. Mature mouse frataxin (78-207) only contributes 7-15% to the total frataxin protein present in mouse tissues. We have also found that truncated mature frataxin (79-207) is present primarily in the cytosol of mouse liver; whereas, frataxin (78-207) is primarily present in the mitochondria. These findings, which provide support for the role of extra-mitochondrial frataxin in the etiology of Friedreich's ataxia, also have important implications for studies of mitochondrial dysfunction conducted in mouse models of frataxin deficiency.
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Affiliation(s)
- Liwei Weng
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Laurent Laboureur
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Qingqing Wang
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Lili Guo
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Peining Xu
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Leah Gottlieb
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - David R Lynch
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Departments of Pediatrics and Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Clementina Mesaros
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ian A Blair
- Penn Medicine/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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11
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Tiano F, Amati F, Cherubini F, Morini E, Vancheri C, Maletta S, Fortuni S, Serio D, Quatrana A, Luffarelli R, Benini M, Alfedi G, Panarello L, Rufini A, Toschi N, Frontali M, Romano S, Marcotulli C, Casali C, Gioiosa S, Mariotti C, Mongelli A, Fichera M, Condò I, Novelli G, Testi R, Malisan F. Frataxin deficiency in Friedreich's ataxia is associated with reduced levels of HAX-1, a regulator of cardiomyocyte death and survival. Hum Mol Genet 2020; 29:471-482. [PMID: 31943004 DOI: 10.1093/hmg/ddz306] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/29/2019] [Accepted: 12/10/2019] [Indexed: 12/31/2022] Open
Abstract
Frataxin deficiency, responsible for Friedreich's ataxia (FRDA), is crucial for cell survival since it critically affects viability of neurons, pancreatic beta cells and cardiomyocytes. In FRDA, the heart is frequently affected with typical manifestation of hypertrophic cardiomyopathy, which can progress to heart failure and cause premature death. A microarray analysis performed on FRDA patient's lymphoblastoid cells stably reconstituted with frataxin, indicated HS-1-associated protein X-1 (HAX-1) as the most significantly upregulated transcript (FC = +2, P < 0.0006). quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and western blot analysis performed on (I) HEK293 stably transfected with empty vector compared to wild-type frataxin and (II) lymphoblasts from FRDA patients show that low frataxin mRNA and protein expression correspond to reduced levels of HAX-1. Frataxin overexpression and silencing were also performed in the AC16 human cardiomyocyte cell line. HAX-1 protein levels are indeed regulated through frataxin modulation. Moreover, correlation between frataxin and HAX-1 was further evaluated in peripheral blood mononuclear cells (PBMCs) from FRDA patients and from non-related healthy controls. A regression model for frataxin which included HAX-1, group membership and group* HAX-1 interaction revealed that frataxin and HAX-1 are associated both at mRNA and protein levels. Additionally, a linked expression of FXN, HAX-1 and antioxidant defence proteins MnSOD and Nrf2 was observed both in PBMCs and AC16 cardiomyocytes. Our results suggest that HAX-1 could be considered as a potential biomarker of cardiac disease in FRDA and the evaluation of its expression might provide insights into its pathogenesis as well as improving risk stratification strategies.
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Affiliation(s)
- Francesca Tiano
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Francesca Amati
- Section of Medical Genetics, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Department of Human Sciences and Quality of Life Promotion, University San Raffaele, 00166 Rome, Italy
| | - Fabio Cherubini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Elena Morini
- Section of Medical Genetics, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Chiara Vancheri
- Section of Medical Genetics, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Sara Maletta
- Section of Medical Genetics, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Silvia Fortuni
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Dario Serio
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Andrea Quatrana
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Riccardo Luffarelli
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Fratagene Therapeutics Srl, 00133 Rome, Italy
| | - Monica Benini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Fratagene Therapeutics Srl, 00133 Rome, Italy
| | - Giulia Alfedi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Fratagene Therapeutics Srl, 00133 Rome, Italy
| | - Luca Panarello
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Alessandra Rufini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Fratagene Therapeutics Srl, 00133 Rome, Italy
| | - Nicola Toschi
- Medical Physics Section, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- A.A. Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA 02129, USA
| | - Marina Frontali
- CNR Institute of Translational Pharmacology, 00133 Rome, Italy
| | - Silvia Romano
- Neurosciences, Mental Health and Sensory Organs (NESMOS) Department, Faculty of Medicine and Psychology, Sapienza University, 00189 Rome, Italy
| | - Christian Marcotulli
- Department of Medical Surgical Sciences and Biotechnologies, Polo Pontino-Sapienza University of Rome, 04100 Latina, Italy
| | - Carlo Casali
- Department of Medical Surgical Sciences and Biotechnologies, Polo Pontino-Sapienza University of Rome, 04100 Latina, Italy
| | - Silvia Gioiosa
- SCAI (Super Computing Applications and Innovations) CINECA, 00185 Rome, Italy
| | - Caterina Mariotti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Alessia Mongelli
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Mario Fichera
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Ivano Condò
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Giuseppe Novelli
- Section of Medical Genetics, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Neuromed Institute, IRCCS, 86077 Pozzilli, Italy
| | - Roberto Testi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
- Fratagene Therapeutics Srl, 00133 Rome, Italy
| | - Florence Malisan
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy
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12
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Stepanova A, Magrané J. Mitochondrial dysfunction in neurons in Friedreich's ataxia. Mol Cell Neurosci 2020; 102:103419. [PMID: 31770591 DOI: 10.1016/j.mcn.2019.103419] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 11/05/2019] [Accepted: 11/08/2019] [Indexed: 12/20/2022] Open
Abstract
Friedreich's ataxia is a multisystemic genetic disorder within the family of mitochondrial diseases that is characterized by reduced levels of the essential mitochondrial protein frataxin. Based on clinical evidence, the peripheral nervous system is affected early, neuronal dysfunction progresses towards the central nervous system, and other organs (such as heart and pancreas) are affected later. However, little attention has been given to the specific aspects of mitochondria function altered by frataxin depletion in the nervous system. For years, commonly accepted views on mitochondria dysfunction in Friedreich's ataxia stemmed from studies using non-neuronal systems and may not apply to neurons, which have their own bioenergetic needs and present a unique, extensive neurite network. Moreover, the basis of the selective neuronal vulnerability, which primarily affects large sensory neurons in the dorsal root ganglia, large principal neurons in the dentate nuclei of the cerebellum, and pyramidal neurons in the cerebral cortex, remains elusive. In order to identify potential misbeliefs in the field and highlight controversies, we reviewed current knowledge on frataxin expression in different tissues, discussed the molecular function of frataxin, and the consequences of its deficiency for mitochondria structural and functional properties, with a focus on the nervous system.
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Affiliation(s)
- Anna Stepanova
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States of America.
| | - Jordi Magrané
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, United States of America.
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13
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Bon C, Luffarelli R, Russo R, Fortuni S, Pierattini B, Santulli C, Fimiani C, Persichetti F, Cotella D, Mallamaci A, Santoro C, Carninci P, Espinoza S, Testi R, Zucchelli S, Condò I, Gustincich S. SINEUP non-coding RNAs rescue defective frataxin expression and activity in a cellular model of Friedreich's Ataxia. Nucleic Acids Res 2019; 47:10728-10743. [PMID: 31584077 PMCID: PMC6847766 DOI: 10.1093/nar/gkz798] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/08/2019] [Accepted: 09/28/2019] [Indexed: 12/16/2022] Open
Abstract
Friedreich's ataxia (FRDA) is an untreatable disorder with neuro- and cardio-degenerative progression. This monogenic disease is caused by the hyper-expansion of naturally occurring GAA repeats in the first intron of the FXN gene, encoding for frataxin, a protein implicated in the biogenesis of iron-sulfur clusters. As the genetic defect interferes with FXN transcription, FRDA patients express a normal frataxin protein but at insufficient levels. Thus, current therapeutic strategies are mostly aimed to restore physiological FXN expression. We have previously described SINEUPs, natural and synthetic antisense long non-coding RNAs, which promote translation of partially overlapping mRNAs through the activity of an embedded SINEB2 domain. Here, by in vitro screening, we have identified a number of SINEUPs targeting human FXN mRNA and capable to up-regulate frataxin protein to physiological amounts acting at the post-transcriptional level. Furthermore, FXN-specific SINEUPs promote the recovery of disease-associated mitochondrial aconitase defects in FRDA-derived cells. In summary, we provide evidence that SINEUPs may be the first gene-specific therapeutic approach to activate FXN translation in FRDA and, more broadly, a novel scalable platform to develop new RNA-based therapies for haploinsufficient diseases.
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Affiliation(s)
- Carlotta Bon
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
| | - Riccardo Luffarelli
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, University of Rome Tor Vergata, Rome, Italy
| | - Roberta Russo
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
| | - Silvia Fortuni
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, University of Rome Tor Vergata, Rome, Italy
| | - Bianca Pierattini
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
| | - Chiara Santulli
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
| | - Cristina Fimiani
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
| | - Francesca Persichetti
- Department of Health Sciences and Interdisciplinary Research Center of Autoimmune Diseases (IRCAD), University of Piemonte Orientale (UPO), Novara, Italy
| | - Diego Cotella
- Department of Health Sciences and Interdisciplinary Research Center of Autoimmune Diseases (IRCAD), University of Piemonte Orientale (UPO), Novara, Italy
| | - Antonello Mallamaci
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
| | - Claudio Santoro
- Department of Health Sciences and Interdisciplinary Research Center of Autoimmune Diseases (IRCAD), University of Piemonte Orientale (UPO), Novara, Italy
| | - Piero Carninci
- RIKEN Center for Life Science Technologies, Division of Genomic Technologies, Yokohama, Kanagawa, Japan
| | - Stefano Espinoza
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Roberto Testi
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, University of Rome Tor Vergata, Rome, Italy
| | - Silvia Zucchelli
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
- Department of Health Sciences and Interdisciplinary Research Center of Autoimmune Diseases (IRCAD), University of Piemonte Orientale (UPO), Novara, Italy
| | - Ivano Condò
- Department of Biomedicine and Prevention, Laboratory of Signal Transduction, University of Rome Tor Vergata, Rome, Italy
| | - Stefano Gustincich
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
- Area of Neuroscience, International School for Advanced Studies (SISSA), Italy
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14
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Jasoliya M, Sacca F, Sahdeo S, Chedin F, Pane C, Brescia Morra V, Filla A, Pook M, Cortopassi G. Dimethyl fumarate dosing in humans increases frataxin expression: A potential therapy for Friedreich's Ataxia. PLoS One 2019; 14:e0217776. [PMID: 31158268 PMCID: PMC6546270 DOI: 10.1371/journal.pone.0217776] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/18/2019] [Indexed: 11/19/2022] Open
Abstract
Friedreich's Ataxia (FA) is an inherited neurodegenerative disorder resulting from decreased expression of the mitochondrial protein frataxin, for which there is no approved therapy. High throughput screening of clinically used drugs identified Dimethyl fumarate (DMF) as protective in FA patient cells. Here we demonstrate that DMF significantly increases frataxin gene (FXN) expression in FA cell model, FA mouse model and in DMF treated humans. DMF also rescues mitochondrial biogenesis deficiency in FA-patient derived cell model. We further examined the mechanism of DMF's frataxin induction in FA patient cells. It has been shown that transcription-inhibitory R-loops form at GAA expansion mutations, thus decreasing FXN expression. In FA patient cells, we demonstrate that DMF significantly increases transcription initiation. As a potential consequence, we observe significant reduction in both R-loop formation and transcriptional pausing thereby significantly increasing FXN expression. Lastly, DMF dosed Multiple Sclerosis (MS) patients showed significant increase in FXN expression by ~85%. Since inherited deficiency in FXN is the primary cause of FA, and DMF is demonstrated to increase FXN expression in humans, DMF could be considered for Friedreich's therapy.
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Affiliation(s)
- Mittal Jasoliya
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Francesco Sacca
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Sunil Sahdeo
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Frederic Chedin
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Chiara Pane
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Vincenzo Brescia Morra
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Alessandro Filla
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Mark Pook
- Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Gino Cortopassi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, United States of America
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15
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Han THL, Camadro JM, Barbault F, Santos R, El Hage Chahine JM, Ha-Duong NT. In Vitro interaction between yeast frataxin and superoxide dismutases: Influence of mitochondrial metals. Biochim Biophys Acta Gen Subj 2019; 1863:883-892. [PMID: 30797804 DOI: 10.1016/j.bbagen.2019.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 02/15/2019] [Accepted: 02/19/2019] [Indexed: 10/27/2022]
Abstract
BACKGROUND Friedreich's ataxia results from a decreased expression of the nuclear gene encoding the mitochondrial protein, frataxin. Frataxin participates in the biosynthesis of iron-sulfur clusters and heme cofactors, as well as in iron storage and protection against oxidative stress. How frataxin interacts with the antioxidant defence components is poorly understood. METHODS Therefore, we have investigated by kinetic, thermodynamic and modelling approaches the molecular interactions between yeast frataxin (Yfh1) and superoxide dismutases, Sod1 and Sod2, and the influence of Yfh1 on their enzymatic activities. RESULTS Yfh1 interacts with cytosolic Sod1 with a dissociation constant, Kd = 1.3 ± 0.3 μM, in two kinetic steps. The first step occurs in the 200 ms range and corresponds to the Yfh1-Sod1 interaction, whereas the second is slow and is assumed to be a change in the conformation of the protein-protein adduct. Furthermore, computational investigations confirm the stability of the Yfh1-Sod1 complex. Yfh1 forms two protein complexes with mitochondrial Sod2 with 1:1 and 2:1 Yfh1/Sod2 stoichiometry (Kd1 = 1.05 ± 0.05 and Kd2 = 6.6 ± 0.1 μM). Furthermore, Yfh1 increases the enzymatic activity of Sod1 while slightly affecting that of Sod2. Finally, the stabilities of the protein-protein adducts and the effect of Yfh1 on superoxide dismutase activities depend on the nature of the mitochondrial metal. CONCLUSIONS This work confirms the participation of Yfh1 in cellular defence against oxidative stress.
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Affiliation(s)
- Thi Hong Lien Han
- Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), CNRS UMR 7086, Univ Paris Diderot, Sorbonne Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Jean-Michel Camadro
- Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, F-75205 Paris Cedex 13, France
| | - Florent Barbault
- Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), CNRS UMR 7086, Univ Paris Diderot, Sorbonne Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Renata Santos
- Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, F-75205 Paris Cedex 13, France
| | - Jean-Michel El Hage Chahine
- Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), CNRS UMR 7086, Univ Paris Diderot, Sorbonne Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Nguyet-Thanh Ha-Duong
- Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), CNRS UMR 7086, Univ Paris Diderot, Sorbonne Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France.
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16
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Llorens JV, Soriano S, Calap-Quintana P, Gonzalez-Cabo P, Moltó MD. The Role of Iron in Friedreich's Ataxia: Insights From Studies in Human Tissues and Cellular and Animal Models. Front Neurosci 2019; 13:75. [PMID: 30833885 PMCID: PMC6387962 DOI: 10.3389/fnins.2019.00075] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 01/23/2019] [Indexed: 12/12/2022] Open
Abstract
Friedreich's ataxia (FRDA) is a rare early-onset degenerative disease that affects both the central and peripheral nervous systems, and other extraneural tissues, mainly the heart and endocrine pancreas. This disorder progresses as a mixed sensory and cerebellar ataxia, primarily disturbing the proprioceptive pathways in the spinal cord, peripheral nerves and nuclei of the cerebellum. FRDA is an inherited disease with an autosomal recessive pattern caused by an insufficient amount of the nuclear-encoded mitochondrial protein frataxin, which is an essential and highly evolutionary conserved protein whose deficit results in iron metabolism dysregulation and mitochondrial dysfunction. The first experimental evidence connecting frataxin with iron homeostasis came from Saccharomyces cerevisiae; iron accumulates in the mitochondria of yeast with deletion of the frataxin ortholog gene. This finding was soon linked to previous observations of iron deposits in the hearts of FRDA patients and was later reported in animal models of the disease. Despite advances made in the understanding of FRDA pathophysiology, the role of iron in this disease has not yet been completely clarified. Some of the questions still unresolved include the molecular mechanisms responsible for the iron accumulation and iron-mediated toxicity. Here, we review the contribution of the cellular and animal models of FRDA and relevance of the studies using FRDA patient samples to gain knowledge about these issues. Mechanisms of mitochondrial iron overload are discussed considering the potential roles of frataxin in the major mitochondrial metabolic pathways that use iron. We also analyzed the effect of iron toxicity on neuronal degeneration in FRDA by reactive oxygen species (ROS)-dependent and ROS-independent mechanisms. Finally, therapeutic strategies based on the control of iron toxicity are considered.
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Affiliation(s)
- José Vicente Llorens
- Department of Genetics, Faculty of Biological Sciences, University of Valencia, Valencia, Spain
- Unit for Psychiatry and Neurodegenerative Diseases, Biomedical Research Institute INCLIVA, Valencia, Spain
| | - Sirena Soriano
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
| | - Pablo Calap-Quintana
- Department of Genetics, Faculty of Biological Sciences, University of Valencia, Valencia, Spain
- Unit for Psychiatry and Neurodegenerative Diseases, Biomedical Research Institute INCLIVA, Valencia, Spain
| | - Pilar Gonzalez-Cabo
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain
- Center of Biomedical Network Research on Rare Diseases CIBERER, Valencia, Spain
- Associated Unit for Rare Diseases INCLIVA-CIPF, Biomedical Research Institute INCLIVA, Valencia, Spain
| | - María Dolores Moltó
- Department of Genetics, Faculty of Biological Sciences, University of Valencia, Valencia, Spain
- Unit for Psychiatry and Neurodegenerative Diseases, Biomedical Research Institute INCLIVA, Valencia, Spain
- Center of Biomedical Network Research on Mental Health CIBERSAM, Valencia, Spain
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17
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Torgovnick A, Schiavi A, Shaik A, Kassahun H, Maglioni S, Rea SL, Johnson TE, Reinhardt HC, Honnen S, Schumacher B, Nilsen H, Ventura N. BRCA1 and BARD1 mediate apoptotic resistance but not longevity upon mitochondrial stress in Caenorhabditis elegans. EMBO Rep 2018; 19:embr.201845856. [PMID: 30366941 DOI: 10.15252/embr.201845856] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 09/14/2018] [Accepted: 09/26/2018] [Indexed: 02/05/2023] Open
Abstract
Interventions that promote healthy aging are typically associated with increased stress resistance. Paradoxically, reducing the activity of core biological processes such as mitochondrial or insulin metabolism promotes the expression of adaptive responses, which in turn increase animal longevity and resistance to stress. In this study, we investigated the relation between the extended Caenorhabditis elegans lifespan elicited by reduction in mitochondrial functionality and resistance to genotoxic stress. We find that reducing mitochondrial activity during development confers germline resistance to DNA damage-induced cell cycle arrest and apoptosis in a cell-non-autonomous manner. We identified the C. elegans homologs of the BRCA1/BARD1 tumor suppressor genes, brc-1/brd-1, as mediators of the anti-apoptotic effect but dispensable for lifespan extension upon mitochondrial stress. Unexpectedly, while reduced mitochondrial activity only in the soma was not sufficient to promote longevity, its reduction only in the germline or in germline-less strains still prolonged lifespan. Thus, in animals with partial reduction in mitochondrial functionality, the mechanisms activated during development to safeguard the germline against genotoxic stress are uncoupled from those required for somatic robustness and animal longevity.
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Affiliation(s)
- Alessandro Torgovnick
- Leibniz Research Institute for Environmental Medicine (IUF), Düsseldorf, Germany.,Clinic I of Internal Medicine, Center for Integrated Oncology, Center for Molecular Medicine and the CECAD Research Center, University of Cologne, Cologne, Germany.,Medical Faculty, Institute for Genome Stability in Aging and Disease, CECAD Research Center, University of Cologne, Cologne, Germany
| | - Alfonso Schiavi
- Leibniz Research Institute for Environmental Medicine (IUF), Düsseldorf, Germany.,Institute for Clinical Chemistry and Laboratory Diagnostic, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Anjumara Shaik
- Leibniz Research Institute for Environmental Medicine (IUF), Düsseldorf, Germany
| | - Henok Kassahun
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway.,Akershus University, Akershus, Norway
| | - Silvia Maglioni
- Leibniz Research Institute for Environmental Medicine (IUF), Düsseldorf, Germany
| | - Shane L Rea
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Thomas E Johnson
- Institute for Behavioral Genetics & Department of Integrative Physiology, University of Colorado at Boulder, Boulder, CO, USA
| | - Hans C Reinhardt
- Clinic I of Internal Medicine, Center for Integrated Oncology, Center for Molecular Medicine and the CECAD Research Center, University of Cologne, Cologne, Germany
| | - Sebastian Honnen
- Medical Faculty, Institute of Toxicology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Björn Schumacher
- Medical Faculty, Institute for Genome Stability in Aging and Disease, CECAD Research Center, University of Cologne, Cologne, Germany
| | - Hilde Nilsen
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway.,Akershus University, Akershus, Norway
| | - Natascia Ventura
- Leibniz Research Institute for Environmental Medicine (IUF), Düsseldorf, Germany .,Institute for Clinical Chemistry and Laboratory Diagnostic, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
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18
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Monnier V, Llorens JV, Navarro JA. Impact of Drosophila Models in the Study and Treatment of Friedreich's Ataxia. Int J Mol Sci 2018; 19:E1989. [PMID: 29986523 PMCID: PMC6073496 DOI: 10.3390/ijms19071989] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/26/2018] [Accepted: 07/03/2018] [Indexed: 02/07/2023] Open
Abstract
Drosophila melanogaster has been for over a century the model of choice of several neurobiologists to decipher the formation and development of the nervous system as well as to mirror the pathophysiological conditions of many human neurodegenerative diseases. The rare disease Friedreich’s ataxia (FRDA) is not an exception. Since the isolation of the responsible gene more than two decades ago, the analysis of the fly orthologue has proven to be an excellent avenue to understand the development and progression of the disease, to unravel pivotal mechanisms underpinning the pathology and to identify genes and molecules that might well be either disease biomarkers or promising targets for therapeutic interventions. In this review, we aim to summarize the collection of findings provided by the Drosophila models but also to go one step beyond and propose the implications of these discoveries for the study and cure of this disorder. We will present the physiological, cellular and molecular phenotypes described in the fly, highlighting those that have given insight into the pathology and we will show how the ability of Drosophila to perform genetic and pharmacological screens has provided valuable information that is not easily within reach of other cellular or mammalian models.
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Affiliation(s)
- Véronique Monnier
- Unité de Biologie Fonctionnelle et Adaptative (BFA), Sorbonne Paris Cité, Université Paris Diderot, UMR8251 CNRS, 75013 Paris, France.
| | - Jose Vicente Llorens
- Department of Genetics, University of Valencia, Campus of Burjassot, 96100 Valencia, Spain.
| | - Juan Antonio Navarro
- Lehrstuhl für Entwicklungsbiologie, Universität Regensburg, 93040 Regensburg, Germany.
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Calap-Quintana P, Navarro JA, González-Fernández J, Martínez-Sebastián MJ, Moltó MD, Llorens JV. Drosophila melanogaster Models of Friedreich's Ataxia. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5065190. [PMID: 29850527 PMCID: PMC5907503 DOI: 10.1155/2018/5065190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 01/29/2018] [Accepted: 02/28/2018] [Indexed: 11/17/2022]
Abstract
Friedreich's ataxia (FRDA) is a rare inherited recessive disorder affecting the central and peripheral nervous systems and other extraneural organs such as the heart and pancreas. This incapacitating condition usually manifests in childhood or adolescence, exhibits an irreversible progression that confines the patient to a wheelchair, and leads to early death. FRDA is caused by a reduced level of the nuclear-encoded mitochondrial protein frataxin due to an abnormal GAA triplet repeat expansion in the first intron of the human FXN gene. FXN is evolutionarily conserved, with orthologs in essentially all eukaryotes and some prokaryotes, leading to the development of experimental models of this disease in different organisms. These FRDA models have contributed substantially to our current knowledge of frataxin function and the pathogenesis of the disease, as well as to explorations of suitable treatments. Drosophila melanogaster, an organism that is easy to manipulate genetically, has also become important in FRDA research. This review describes the substantial contribution of Drosophila to FRDA research since the characterization of the fly frataxin ortholog more than 15 years ago. Fly models have provided a comprehensive characterization of the defects associated with frataxin deficiency and have revealed genetic modifiers of disease phenotypes. In addition, these models are now being used in the search for potential therapeutic compounds for the treatment of this severe and still incurable disease.
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Affiliation(s)
- P. Calap-Quintana
- Department of Genetics, University of Valencia, Campus of Burjassot, Valencia, Spain
| | - J. A. Navarro
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - J. González-Fernández
- Department of Genetics, University of Valencia, Campus of Burjassot, Valencia, Spain
- Biomedical Research Institute INCLIVA, Valencia, Spain
| | | | - M. D. Moltó
- Department of Genetics, University of Valencia, Campus of Burjassot, Valencia, Spain
- Biomedical Research Institute INCLIVA, Valencia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
| | - J. V. Llorens
- Department of Genetics, University of Valencia, Campus of Burjassot, Valencia, Spain
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Koeppen AH, Becker AB, Qian J, Gelman BB, Mazurkiewicz JE. Friedreich Ataxia: Developmental Failure of the Dorsal Root Entry Zone. J Neuropathol Exp Neurol 2017; 76:969-977. [PMID: 29044418 DOI: 10.1093/jnen/nlx087] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Dorsal root ganglia, dorsal roots (DR), and dorsal root entry zones (DREZ) are vulnerable to frataxin deficiency in Friedreich ataxia (FA). A previously unrecognized abnormality is the intrusion of astroglial tissue into DR. Segments of formalin-fixed upper lumbar spinal cord of 13 homozygous and 2 compound heterozygous FA patients were sectioned longitudinally to represent DREZ and stained for glial fibrillary acidic protein (GFAP), S100, vimentin, the central nervous system (CNS)-specific myelin protein proteolipid protein, the peripheral nervous system (PNS) myelin proteins PMP-22 and P0, and the Schwann cell proteins laminin, alpha-dystroglycan, and periaxin. Normal DREZ showed short, sharply demarcated, dome-like extensions of CNS tissue into DR. The Schwann cell-related proteins formed tight caps around these domes. In FA, GFAP-, S100-, and vimentin-reactive CNS tissue extended across DREZ and into DR over much longer distances by breaching the CNS-PNS barrier. The transition between PNS and CNS myelin proteins was disorganized. During development, neural-crest derived boundary cap cells provide guidance to dorsal root ganglia axons growing into the dorsal spinal cord and at the same time block the inappropriate intrusion of CNS glia into DR. It is likely that frataxin is required during a critical period of permissive (axons) and nonpermissive (astroglia) border-control.
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Affiliation(s)
- Arnulf H Koeppen
- Research Service, Veterans Affairs Medical Center, Albany, New York; Department of Pathology, Albany Medical College, Albany, New York; Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, Texas; Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York
| | - Alyssa B Becker
- Research Service, Veterans Affairs Medical Center, Albany, New York; Department of Pathology, Albany Medical College, Albany, New York; Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, Texas; Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York
| | - Jiang Qian
- Research Service, Veterans Affairs Medical Center, Albany, New York; Department of Pathology, Albany Medical College, Albany, New York; Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, Texas; Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York
| | - Benjamin B Gelman
- Research Service, Veterans Affairs Medical Center, Albany, New York; Department of Pathology, Albany Medical College, Albany, New York; Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, Texas; Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York
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22
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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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23
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Koeppen AH, Becker AB, Feustel PJ, Gelman BB, Mazurkiewicz JE. The significance of intercalated discs in the pathogenesis of Friedreich cardiomyopathy. J Neurol Sci 2016; 367:171-6. [PMID: 27423584 DOI: 10.1016/j.jns.2016.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/18/2016] [Accepted: 06/02/2016] [Indexed: 11/25/2022]
Abstract
Friedreich ataxia (FRDA) is an autosomal recessive disorder with a complex clinical and neuropathological phenotype, but the most frequent cause of death is cardiomyopathy. The principal autopsy findings in FRDA hearts are concentric hypertrophy, enlargement of cardiomyocytes, myofiber necrosis, inflammatory infiltration, scarring, and random accumulation of iron. In addition, the myocardium shows generalized disorganization of intercalated discs (ICD), the Velcro-like end-to-end connections of heart fibers that provide mechanical cohesion and ionic coupling. The principal components of ICD are fascia adherens junctions (FAJ), desmosomes, and gap junctions. Frataxin deficiency in FRDA may cause improper assembly of ICD early in life, making hearts vulnerable to mechanical stress in childhood and adolescence. We studied the ICD in the myocardium of left ventricular wall (LVW), right ventricular wall, and ventricular septum in 18 genetically confirmed FRDA patients (age of death, 10 to 87years) and 12 normal controls (age of death, 13 to 69years). In cases with juvenile onset, electron microscopy and immunohistochemistry of N-cadherin and vinculin, two abundant FAJ proteins, showed enlargement of ICD, discontinuity, and hyperconvolution. Reaction product of the desmosomal protein desmoglein 2 was similar. The distribution of the gap junction protein connexin 43 at ICD was also irregular and displayed abnormal lateralization to the plasma membranes of cardiomyocytes. Confocal immunofluorescence microscopy of α-actinin, affinity fluorescence microscopy of actin with rhodamine-labeled phalloidin, and electron microscopy, revealed the principal integrity of sarcomeres of the myocardium in FRDA. In two late-onset long-surviving FRDA patients (ages 79 and 87), clinical cardiomyopathy was absent, and ICD were normal. The described observations in patients with a broad range of disease onset and duration allow us to conclude that faulty assembly of ICD interferes with proper end-to-end adhesion of cardiomyocytes of the growing heart and contributes to the pathogenesis of FRDA cardiomyopathy.
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Affiliation(s)
- Arnulf H Koeppen
- Research Service, Veterans Affairs Medical Center, Albany, NY, USA; Department of Neurology, Albany Medical College, Albany, NY, USA; Department of Pathology, Albany Medical College, Albany, NY, USA.
| | - Alyssa B Becker
- Research Service, Veterans Affairs Medical Center, Albany, NY, USA
| | - Paul J Feustel
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, USA
| | | | - Joseph E Mazurkiewicz
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, USA
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Koeppen AH, Ramirez RL, Becker AB, Mazurkiewicz JE. Dorsal root ganglia in Friedreich ataxia: satellite cell proliferation and inflammation. Acta Neuropathol Commun 2016; 4:46. [PMID: 27142428 PMCID: PMC4855486 DOI: 10.1186/s40478-016-0288-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 02/13/2016] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION Dorsal root ganglia (DRG) are highly vulnerable to frataxin deficiency in Friedreich ataxia (FA), an autosomal recessive disease due to pathogenic homozygous guanine-adenine-adenine trinucleotide repeat expansions in intron 1 of the FXN gene (chromosome 9q21.11). An immunohistochemical and immunofluorescence study of DRG in 15 FA cases and 12 controls revealed that FA causes major primary changes in satellite cells and inflammatory destruction of neurons. A panel of antibodies was used to reveal the cytoplasm of satellite cells (glutamine synthetase, S100, metabotropic glutamate receptors 2/3, excitatory amino acid transporter 1, ATP-sensitive inward rectifier potassium channel 10, and cytosolic ferritin), gap junctions (connexin 43), basement membranes (laminin), mitochondria (ATP synthase subunit beta and frataxin), and monocytes (CD68 and IBA1). RESULTS Reaction product of the cytoplasmic markers and laminin confirmed proliferation of satellite cells and processes into multiple perineuronal layers and residual nodules. The formation of connexin 43-reactive gap junctions between satellite cells was strongly upregulated. Proliferating satellite cells in FA displayed many more frataxin- and ATP5B-reactive mitochondria than normal. Monocytes entered into the satellite cell layer, appeared to penetrate neuronal plasma membranes, and infiltrated residual nodules. Satellite cells and IBA1-reactive monocytes displayed upregulated ferritin biosynthesis, which was most likely due to leakage of iron from dying neurons. CONCLUSIONS We conclude that FA differentially affects the key cellular elements of DRG, and postulate that the disease causes loss of bidirectional trophic support between satellite cells and neurons.
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Affiliation(s)
- Arnulf H Koeppen
- Research Service, Veterans Affairs Medical Center, Albany, NY, USA.
- Departments of Neurology and Pathology, Albany Medical College, Albany, NY, USA.
| | - R Liane Ramirez
- Research Service, Veterans Affairs Medical Center, Albany, NY, USA
| | - Alyssa B Becker
- Research Service, Veterans Affairs Medical Center, Albany, NY, USA
| | - Joseph E Mazurkiewicz
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY, USA
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Turowski VR, Aknin C, Maliandi MV, Buchensky C, Leaden L, Peralta DA, Busi MV, Araya A, Gomez-Casati DF. Frataxin Is Localized to Both the Chloroplast and Mitochondrion and Is Involved in Chloroplast Fe-S Protein Function in Arabidopsis. PLoS One 2015; 10:e0141443. [PMID: 26517126 PMCID: PMC4636843 DOI: 10.1371/journal.pone.0141443] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/07/2015] [Indexed: 11/19/2022] Open
Abstract
Frataxin plays a key role in eukaryotic cellular iron metabolism, particularly in mitochondrial heme and iron-sulfur (Fe-S) cluster biosynthesis. However, its precise role has yet to be elucidated. In this work, we studied the subcellular localization of Arabidopsis frataxin, AtFH, using confocal microscopy, and found a novel dual localization for this protein. We demonstrate that plant frataxin is targeted to both the mitochondria and the chloroplast, where it may play a role in Fe-S cluster metabolism as suggested by functional studies on nitrite reductase (NIR) and ferredoxin (Fd), two Fe-S containing chloroplast proteins, in AtFH deficient plants. Our results indicate that frataxin deficiency alters the normal functioning of chloroplasts by affecting the levels of Fe, chlorophyll, and the photosynthetic electron transport chain in this organelle.
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Affiliation(s)
- Valeria R. Turowski
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Cindy Aknin
- UMR5234 Microbiologie Fondamentale et Pathogénicité, Centre National de la Recherche Scientifique and Université Bordeaux-Segalen, 146 rue Léo Saignat, 33076, Bordeaux cedex, France
| | - Maria V. Maliandi
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH) CONICET/UNSAM, Camino de Circunvaación Km 6, 7130, Chascomús, Argentina
| | - Celeste Buchensky
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Laura Leaden
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Diego A. Peralta
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Maria V. Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Alejandro Araya
- Centre National de la Recherche Scientifique & UMR 1332 –Biologie du Fruit et Pathologie, Institute National de la Recherche Agronomique (INRA) Bordeaux Aquitaine, 71 avenue Edouard Bourlaux, 33882, Villenave D’Ornon, France
| | - Diego F. Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
- * E-mail:
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Cherubini F, Serio D, Guccini I, Fortuni S, Arcuri G, Condò I, Rufini A, Moiz S, Camerini S, Crescenzi M, Testi R, Malisan F. Src inhibitors modulate frataxin protein levels. Hum Mol Genet 2015; 24:4296-305. [PMID: 25948553 DOI: 10.1093/hmg/ddv162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/30/2015] [Indexed: 12/19/2022] Open
Abstract
Defective expression of frataxin is responsible for the inherited, progressive degenerative disease Friedreich's Ataxia (FRDA). There is currently no effective approved treatment for FRDA and patients die prematurely. Defective frataxin expression causes critical metabolic changes, including redox imbalance and ATP deficiency. As these alterations are known to regulate the tyrosine kinase Src, we investigated whether Src might in turn affect frataxin expression. We found that frataxin can be phosphorylated by Src. Phosphorylation occurs primarily on Y118 and promotes frataxin ubiquitination, a signal for degradation. Accordingly, Src inhibitors induce accumulation of frataxin but are ineffective on a non-phosphorylatable frataxin-Y118F mutant. Importantly, all the Src inhibitors tested, some of them already in the clinic, increase frataxin expression and rescue the aconitase defect in frataxin-deficient cells derived from FRDA patients. Thus, Src inhibitors emerge as a new class of drugs able to promote frataxin accumulation, suggesting their possible use as therapeutics in FRDA.
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Affiliation(s)
- Fabio Cherubini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy
| | - Dario Serio
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy
| | - Ilaria Guccini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy
| | - Silvia Fortuni
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy, Fratagene Therapeutics Ltd, 22 Northumberland Rd, Dublin, Ireland and
| | - Gaetano Arcuri
- 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
| | - Alessandra Rufini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy, Fratagene Therapeutics Ltd, 22 Northumberland Rd, Dublin, Ireland and
| | - Shadman Moiz
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy
| | - Serena Camerini
- Department of Cell Biology and Neurosciences, Italian National Institute of Health, Viale Regina Elena, 299, 00161 Rome, Italy
| | - Marco Crescenzi
- Department of Cell Biology and Neurosciences, Italian National Institute of Health, Viale Regina Elena, 299, 00161 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 Ltd, 22 Northumberland Rd, Dublin, Ireland and
| | - Florence Malisan
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy,
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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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Koeppen AH, Ramirez RL, Becker AB, Bjork ST, Levi S, Santambrogio P, Parsons PJ, Kruger PC, Yang KX, Feustel PJ, Mazurkiewicz JE. The pathogenesis of cardiomyopathy in Friedreich ataxia. PLoS One 2015; 10:e0116396. [PMID: 25738292 PMCID: PMC4349588 DOI: 10.1371/journal.pone.0116396] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/09/2014] [Indexed: 12/21/2022] Open
Abstract
Friedreich ataxia (FA) is an autosomal recessive disease with a complex neurological phenotype, but the most common cause of death is heart failure. This study presents a systematic analysis of 15 fixed and 13 frozen archival autopsy tissues of FA hearts and 10 normal controls (8 frozen) by measurement of cardiomyocyte hypertrophy; tissue frataxin assay; X-ray fluorescence (XRF) of iron (Fe) and zinc (Zn) in polyethylene glycol-embedded samples of left and right ventricular walls (LVW, RVW) and ventricular septum (VS); metal quantification in bulk digests by inductively-coupled plasma optical emission spectrometry (ICP-OES); Fe histochemistry; and immunohistochemistry and immunofluorescence of cytosolic and mitochondrial ferritins and of the inflammatory markers CD68 and hepcidin. FA cardiomyocytes were significantly larger than normal and surrounded by fibrotic endomysium. Frataxin in LVW was reduced to less than 15 ng/g wet weight (normal 235.4±75.1 ng/g). All sections displayed characteristic Fe-reactive inclusions in cardiomyocytes, and XRF confirmed significant regional Fe accumulation in LVW and VS. In contrast, ICP-OES analysis of bulk extracts revealed normal total Fe levels in LVW, RVW, and VS. Cardiac Zn remained normal by XRF and assay of bulk digests. Cytosolic and mitochondrial ferritins exhibited extensive co-localization in cardiomyocytes, representing translational and transcriptional responses to Fe, respectively. Fe accumulation progressed from a few small granules to coarse aggregates in phagocytized cardiomyocytes. All cases met the “Dallas criteria” of myocarditis. Inflammatory cells contained CD68 and cytosolic ferritin, and most also expressed the Fe-regulatory hormone hepcidin. Inflammation is an important factor in the pathogenesis of FA cardiomyopathy but may be more evident in advanced stages of the disease. Hepcidin-induced failure of Fe export from macrophages is a likely contributory cause of damage to the heart in FA. Frataxin replacement and anti-inflammatory agents are potential therapies in FA cardiomyopathy.
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Affiliation(s)
- Arnulf H. Koeppen
- Research, Neurology, and Pathology Services, Veterans Affairs Medical Center, Albany, New York, United States of America
- Departments of Neurology and Pathology, Albany Medical College, Albany, New York, United States of America
- * E-mail:
| | - R. Liane Ramirez
- Research Service, Veterans Affairs Medical Center, Albany, New York, United States of America
| | - Alyssa B. Becker
- Research Service, Veterans Affairs Medical Center, Albany, New York, United States of America
| | - Sarah T. Bjork
- Research Service, Veterans Affairs Medical Center, Albany, New York, United States of America
| | - Sonia Levi
- San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | | | - Patrick J. Parsons
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
- Department of Environmental Health Sciences, University at Albany, Albany, New York, United States of America
| | - Pamela C. Kruger
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Karl X. Yang
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
- Department of Environmental Health Sciences, University at Albany, Albany, New York, United States of America
| | - Paul J. Feustel
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Joseph E. Mazurkiewicz
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
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Rufini A, Cavallo F, Condò I, Fortuni S, De Martino G, Incani O, Di Venere A, Benini M, Massaro DS, Arcuri G, Serio D, Malisan F, Testi R. Highly specific ubiquitin-competing molecules effectively promote frataxin accumulation and partially rescue the aconitase defect in Friedreich ataxia cells. Neurobiol Dis 2015; 75:91-9. [PMID: 25549872 PMCID: PMC4358773 DOI: 10.1016/j.nbd.2014.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 11/30/2022] Open
Abstract
Friedreich ataxia is an inherited neurodegenerative disease that leads to progressive disability. There is currently no effective treatment and patients die prematurely. The underlying genetic defect leads to reduced expression of the mitochondrial protein frataxin. Frataxin insufficiency causes mitochondrial dysfunction and ultimately cell death, particularly in peripheral sensory ganglia. There is an inverse correlation between the amount of residual frataxin and the severity of disease progression; therefore, therapeutic approaches aiming at increasing frataxin levels are expected to improve patients' conditions. We previously discovered that a significant amount of frataxin precursor is degraded by the ubiquitin/proteasome system before its functional mitochondrial maturation. We also provided evidence for the therapeutic potential of small molecules that increase frataxin levels by docking on the frataxin ubiquitination site, thus preventing frataxin ubiquitination and degradation. We called these compounds ubiquitin-competing molecules (UCM). By extending our search for effective UCM, we identified a set of new and more potent compounds that more efficiently promote frataxin accumulation. Here we show that these compounds directly interact with frataxin and prevent its ubiquitination. Interestingly, these UCM are not effective on the ubiquitin-resistant frataxin mutant, indicating their specific action on preventing frataxin ubiquitination. Most importantly, these compounds are able to promote frataxin accumulation and aconitase rescue in cells derived from patients, strongly supporting their therapeutic potential.
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Affiliation(s)
- Alessandra Rufini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy; Fratagene Therapeutics Ltd., 22 Northumberland Rd., Dublin, Ireland
| | - Francesca Cavallo
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Ivano Condò
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Silvia Fortuni
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy; Fratagene Therapeutics Ltd., 22 Northumberland Rd., Dublin, Ireland
| | - Gabriella De Martino
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Ottaviano Incani
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Almerinda Di Venere
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Monica Benini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Damiano Sergio Massaro
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Gaetano Arcuri
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Dario Serio
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Florence Malisan
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy
| | - Roberto Testi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Via Montpellier 1, Rome 00133, Italy; Fratagene Therapeutics Ltd., 22 Northumberland Rd., Dublin, Ireland.
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Koeppen AH, Ramirez L, Becker AB, Feustel PJ, Mazurkiewicz JE. Friedreich ataxia: failure of GABA-ergic and glycinergic synaptic transmission in the dentate nucleus. J Neuropathol Exp Neurol 2015; 74:166-76. [PMID: 25575136 PMCID: PMC4294979 DOI: 10.1097/nen.0000000000000160] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Atrophy of large neurons in the dentate nucleus (DN) is an important pathologic correlate of neurologic disability in patients with Friedreich ataxia (FA). Thinning of the DN was quantified in 29 autopsy cases of FA and 2 carriers by measuring the thickness of the gray matter ribbon on stains with anti-glutamic acid decarboxylase, the rate-limiting enzyme in the biosynthesis of γ-amino-butyric acid (GABA). The DN was thinner than normal in all cases of FA, and atrophy correlated inversely with disease duration but not with age at onset or length of the homozygous guanine-adenine-adenine trinucleotide expansions. In 13 of the FA cases, frozen DN tissue was available for assay of frataxin. Dentate nucleus atrophy was more severe when frataxin was very low. Immunohistochemical staining for glutamic acid decarboxylase revealed grumose reaction and preservation of small GABA-ergic neurons in the DN of FA patients. Residual small DN neurons and varicose axons also contained the glycine transporter 2, identifying them as glycinergic. Immunohistochemistry also confirmed severe loss of GABA-A and glycine receptors in the DN with comparable depletion of the receptor-anchoring protein gephyrin. Thus, loss of gephyrin and failure to position GABA-A and glycine receptors correctly may reduce trophic support of large DN neurons and contribute to their atrophy. By contrast, Purkinje cells may escape retrograde atrophy in FA by issuing new axonal sprouts to small surviving DN neurons where they form reparative grumose clusters.
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Affiliation(s)
- Arnulf H. Koeppen
- Research Service, VA Medical Center, Albany, New York
- Department of Neurology, Albany Medical College, Albany, New York
- Department of Pathology, Albany Medical College, Albany, New York
| | - Liane Ramirez
- Research Service, VA Medical Center, Albany, New York
| | | | - Paul J. Feustel
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York
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Sahdeo S, Scott BD, McMackin MZ, Jasoliya M, Brown B, Wulff H, Perlman SL, Pook MA, Cortopassi GA. Dyclonine rescues frataxin deficiency in animal models and buccal cells of patients with Friedreich's ataxia. Hum Mol Genet 2014; 23:6848-62. [PMID: 25113747 PMCID: PMC4245046 DOI: 10.1093/hmg/ddu408] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/02/2014] [Accepted: 08/04/2014] [Indexed: 12/18/2022] Open
Abstract
Inherited deficiency in the mitochondrial protein frataxin (FXN) causes the rare disease Friedreich's ataxia (FA), for which there is no successful treatment. We identified a redox deficiency in FA cells and used this to model the disease. We screened a 1600-compound library to identify existing drugs, which could be of therapeutic benefit. We identified the topical anesthetic dyclonine as protective. Dyclonine increased FXN transcript and FXN protein dose-dependently in FA cells and brains of animal models. Dyclonine also rescued FXN-dependent enzyme deficiencies in the iron-sulfur enzymes, aconitase and succinate dehydrogenase. Dyclonine induces the Nrf2 [nuclear factor (erythroid-derived 2)-like 2] transcription factor, which we show binds an upstream response element in the FXN locus. Additionally, dyclonine also inhibited the activity of histone methyltransferase G9a, known to methylate histone H3K9 to silence FA chromatin. Chronic dosing in a FA mouse model prevented a performance decline in balance beam studies. A human clinical proof-of-concept study was completed in eight FA patients dosed twice daily using a 1% dyclonine rinse for 1 week. Six of the eight patients showed an increase in buccal cell FXN levels, and fold induction was significantly correlated with disease severity. Dyclonine represents a novel therapeutic strategy that can potentially be repurposed for the treatment of FA.
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Affiliation(s)
- Sunil Sahdeo
- Department of Molecular Biosciences, School of Veterinary Medicine
| | - Brian D Scott
- Department of Molecular Biosciences, School of Veterinary Medicine
| | | | - Mittal Jasoliya
- Department of Molecular Biosciences, School of Veterinary Medicine
| | - Brandon Brown
- Department of Pharmacology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Heike Wulff
- Department of Pharmacology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Susan L Perlman
- Department of Neurology, University of California School of Medicine, Los Angeles, CA 90095, USA and
| | - Mark A Pook
- School of Health Sciences and Social Care, Brunel University, Uxbridge UB8 3PH, UK
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Abstract
Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.
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Affiliation(s)
- Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| | - Lorenzo Galluzzi
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, F-75006 Paris, France. Université Paris Descartes/Paris V; Sorbonne Paris Cité; F-75005 Paris, France. INSERM, U1138, F-94805 Villejuif, France
| | - Guido Kroemer
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, F-75006 Paris, France. Université Paris Descartes/Paris V; Sorbonne Paris Cité; F-75005 Paris, France. INSERM, U1138, F-94805 Villejuif, France. Metabolomics and Cell Biology Platforms, Gustave Roussy, F-94805 Villejuif, France. Pôle de Biologie, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, F-75015 Paris, France.
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Friedreich's Ataxia: A Neuronal Point of View on the Oxidative Stress Hypothesis. Antioxidants (Basel) 2014; 3:592-603. [PMID: 26785073 PMCID: PMC4665420 DOI: 10.3390/antiox3030592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 05/06/2014] [Accepted: 05/16/2014] [Indexed: 12/02/2022] Open
Abstract
A prominent feature of Friedreich’s ataxia (FRDA) is the neurodegeneration of the central and peripheral nervous systems, but little information is available about the mechanisms leading to neuronal damage in this pathology. Currently, no treatments delay, prevent, or reverse the inexorable decline that occurs in this condition. Evidence of oxidative damage has been demonstrated in Friedreich’s ataxia, and this damage has been proposed as the origin of the disease. Nevertheless, the role of oxidative stress in FRDA remains debatable. The lack of direct evidence of reactive oxygen species overproduction in FRDA cells and tissues and the failure of exogenous antioxidants to rescue FRDA phenotypes questions the role of oxidative stress in this pathology. For example, the antioxidant “idebenone” ameliorates cardiomyopathy in FRDA patients, but this therapy does not improve neurodegeneration. To date, no known pharmacological treatment with antioxidant properties cures or delays FRDA neuropathology. This review reports and discusses the evidence of oxidative stress in FRDA and focuses on the existing knowledge of the apparent ineffectiveness of antioxidants for the treatment of neuronal damage.
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Lim SC, Friemel M, Marum JE, Tucker EJ, Bruno DL, Riley LG, Christodoulou J, Kirk EP, Boneh A, DeGennaro CM, Springer M, Mootha VK, Rouault TA, Leimkühler S, Thorburn DR, Compton AG. Mutations in LYRM4, encoding iron-sulfur cluster biogenesis factor ISD11, cause deficiency of multiple respiratory chain complexes. Hum Mol Genet 2013; 22:4460-73. [PMID: 23814038 DOI: 10.1093/hmg/ddt295] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Iron-sulfur clusters (ISCs) are important prosthetic groups that define the functions of many proteins. Proteins with ISCs (called iron-sulfur or Fe-S proteins) are present in mitochondria, the cytosol, the endoplasmic reticulum and the nucleus. They participate in various biological pathways including oxidative phosphorylation (OXPHOS), the citric acid cycle, iron homeostasis, heme biosynthesis and DNA repair. Here, we report a homozygous mutation in LYRM4 in two patients with combined OXPHOS deficiency. LYRM4 encodes the ISD11 protein, which forms a complex with, and stabilizes, the sulfur donor NFS1. The homozygous mutation (c.203G>T, p.R68L) was identified via massively parallel sequencing of >1000 mitochondrial genes (MitoExome sequencing) in a patient with deficiency of complexes I, II and III in muscle and liver. These three complexes contain ISCs. Sanger sequencing identified the same mutation in his similarly affected cousin, who had a more severe phenotype and died while a neonate. Complex IV was also deficient in her skeletal muscle. Several other Fe-S proteins were also affected in both patients, including the aconitases and ferrochelatase. Mutant ISD11 only partially complemented for an ISD11 deletion in yeast. Our in vitro studies showed that the l-cysteine desulfurase activity of NFS1 was barely present when co-expressed with mutant ISD11. Our findings are consistent with a defect in the early step of ISC assembly affecting a broad variety of Fe-S proteins. The differences in biochemical and clinical features between the two patients may relate to limited availability of cysteine in the newborn period and suggest a potential approach to therapy.
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Affiliation(s)
- Sze Chern Lim
- Murdoch Childrens Research Institute, Royal Children's Hospital, Flemington Road, Parkville, VIC 3052, Australia
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Lavecchia A, Di Giovanni C, Cerchia C, Russo A, Russo G, Novellino E. Discovery of a novel small molecule inhibitor targeting the frataxin/ubiquitin interaction via structure-based virtual screening and bioassays. J Med Chem 2013; 56:2861-73. [PMID: 23506486 DOI: 10.1021/jm3017199] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Friedreich's ataxia (FRDA) is an autosomal recessive neuro- and cardiodegenerative disorder for which there are no proven effective treatments. FRDA is caused by decreased expression and/or function of the mitochondrial protein frataxin. Here, we report findings that frataxin is degraded via the ubiquitin-proteasomal pathway and that it is ubiquitinated at residue K(147) in Calu-6 cells. A theoretical model of the frataxin-K(147)/Ub complex, constructed by combining bioinformatics interface predictions with information-driven docking, revealed a hitherto unnoticed, potential ubiquitin-binding domain in frataxin. Through structure-based virtual screening and cell-based assays, we discovered a novel small molecule (compound (+)-11) able to prevent frataxin ubiquitination and degradation. (+)-11 was synthesized and tested for specific binding to frataxin by an UF-LC/MS based ligand-binding assay. Follow-up scaffold-based searches resulted in the identification of a lead series with micromolar activity in disrupting the frataxin/Ub interaction. This study also suggests that frataxin could be a potential target for FRDA drug development.
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Affiliation(s)
- Antonio Lavecchia
- Dipartimento di Chimica Farmaceutica e Tossicologica, Drug Discovery Laboratory, Università di Napoli Federico II, Via Domenico Montesano 49, 80131 Napoli, Italy.
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Schiavi A, Torgovnick A, Kell A, Megalou E, Castelein N, Guccini I, Marzocchella L, Gelino S, Hansen M, Malisan F, Condò I, Bei R, Rea SL, Braeckman BP, Tavernarakis N, Testi R, Ventura N. Autophagy induction extends lifespan and reduces lipid content in response to frataxin silencing in C. elegans. Exp Gerontol 2013; 48:191-201. [PMID: 23247094 PMCID: PMC3572394 DOI: 10.1016/j.exger.2012.12.002] [Citation(s) in RCA: 52] [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: 11/13/2012] [Accepted: 12/04/2012] [Indexed: 02/02/2023]
Abstract
Severe mitochondria deficiency leads to a number of devastating degenerative disorders, yet, mild mitochondrial dysfunction in different species, including the nematode Caenorhabditis elegans, can have pro-longevity effects. This apparent paradox indicates that cellular adaptation to partial mitochondrial stress can induce beneficial responses, but how this is achieved is largely unknown. Complete absence of frataxin, the mitochondrial protein defective in patients with Friedreich's ataxia, is lethal in C. elegans, while its partial deficiency extends animal lifespan in a p53 dependent manner. In this paper we provide further insight into frataxin control of C. elegans longevity by showing that a substantial reduction of frataxin protein expression is required to extend lifespan, affect sensory neurons functionality, remodel lipid metabolism and trigger autophagy. We find that Beclin and p53 genes are required to induce autophagy and concurrently reduce lipid storages and extend animal lifespan in response to frataxin suppression. Reciprocally, frataxin expression modulates autophagy in the absence of p53. Human Friedreich ataxia-derived lymphoblasts also display increased autophagy, indicating an evolutionarily conserved response to reduced frataxin expression. In sum, we demonstrate a causal connection between induction of autophagy and lifespan extension following reduced frataxin expression, thus providing the rationale for investigating autophagy in the pathogenesis and treatment of Friedreich's ataxia and possibly other human mitochondria-associated disorders.
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Affiliation(s)
- Alfonso Schiavi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
- Institute of Clinical Chemistry and Laboratory Medicine of the Heinrich Heine University, and the IUF-Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Alessandro Torgovnick
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
- Institute of Clinical Chemistry and Laboratory Medicine of the Heinrich Heine University, and the IUF-Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Alison Kell
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Evgenia Megalou
- IMBB, Foundation for Research and Technology, Heraklion 71110, Crete, Greece
| | | | - Ilaria Guccini
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Laura Marzocchella
- Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Sara Gelino
- Sanford-Burnham Medical Research Institute, Graduate School of Biomedical Sciences, Del E. Webb Neuroscience, Aging and Stem Cell Research Center, Program of Development and Aging, La Jolla, CA, USA
| | - Malene Hansen
- Sanford-Burnham Medical Research Institute, Graduate School of Biomedical Sciences, Del E. Webb Neuroscience, Aging and Stem Cell Research Center, Program of Development and Aging, La Jolla, CA, USA
| | - Florence Malisan
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Ivano Condò
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Roberto Bei
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Shane L. Rea
- Sam and Ann Barshop Institute for Longevity and Aging Studies and the Department of Physiology, UTHSCSA, San Antonio, TX, USA
| | | | | | - Roberto Testi
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Natascia Ventura
- Laboratory of Signal Transduction, Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, 00133 Rome, Italy
- Institute of Clinical Chemistry and Laboratory Medicine of the Heinrich Heine University, and the IUF-Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
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Xia H, Cao Y, Dai X, Marelja Z, Zhou D, Mo R, Al-Mahdawi S, Pook MA, Leimkühler S, Rouault TA, Li K. Novel frataxin isoforms may contribute to the pathological mechanism of Friedreich ataxia. PLoS One 2012; 7:e47847. [PMID: 23082224 PMCID: PMC3474739 DOI: 10.1371/journal.pone.0047847] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 09/21/2012] [Indexed: 12/12/2022] Open
Abstract
Friedreich ataxia (FRDA) is an inherited neurodegenerative disease caused by frataxin (FXN) deficiency. The nervous system and heart are the most severely affected tissues. However, highly mitochondria-dependent tissues, such as kidney and liver, are not obviously affected, although the abundance of FXN is normally high in these tissues. In this study we have revealed two novel FXN isoforms (II and III), which are specifically expressed in affected cerebellum and heart tissues, respectively, and are functional in vitro and in vivo. Increasing the abundance of the heart-specific isoform III significantly increased the mitochondrial aconitase activity, while over-expression of the cerebellum-specific isoform II protected against oxidative damage of Fe-S cluster-containing aconitase. Further, we observed that the protein level of isoform III decreased in FRDA patient heart, while the mRNA level of isoform II decreased more in FRDA patient cerebellum compared to total FXN mRNA. Our novel findings are highly relevant to understanding the mechanism of tissue-specific pathology in FRDA.
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Affiliation(s)
- Haiyan Xia
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
| | - Yun Cao
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
| | - Xiaoman Dai
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
| | - Zvonimir Marelja
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Di Zhou
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
| | - Ran Mo
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
| | - Sahar Al-Mahdawi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University, Uxbridge, United Kingdom
| | - Mark A. Pook
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University, Uxbridge, United Kingdom
| | - Silke Leimkühler
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Tracey A. Rouault
- Molecular Medicine Program, National Institute of Child Health and Human Development, Bethesda, Maryland, United States of America
| | - Kuanyu Li
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
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38
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Abstract
Friedreich ataxia is a rare disorder characterized by an autosomal recessive pattern of inheritance. The disease is noted for a constellation of clinical symptoms, notably loss of coordination and a variety of neurologic and cardiac complications. More recently, scientists have focused their research on an array of general investigations of the underlying cellular basis for the disease, including mitochondrial biogenesis, iron-sulfur cluster synthesis, iron metabolism, antioxidant responses, and mitophagy. Combined with investigations that have explored the pathogenesis of the disease and the function of the protein frataxin, these studies have led to insights that will be key to identifying new therapeutic strategies for treating the disease.
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Affiliation(s)
- Massimo Pandolfo
- Université Libre de Bruxelles, Hôpital Erasme, Brussels, Belgium.
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Lefevre S, Sliwa D, Auchère F, Brossas C, Ruckenstuhl C, Boggetto N, Lesuisse E, Madeo F, Camadro JM, Santos R. The yeast metacaspase is implicated in oxidative stress response in frataxin-deficient cells. FEBS Lett 2012; 586:143-8. [PMID: 22155640 DOI: 10.1016/j.febslet.2011.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 11/18/2011] [Accepted: 12/01/2011] [Indexed: 12/01/2022]
Abstract
Friedreich ataxia is the most common recessive neurodegenerative disease and is caused by reduced expression of mitochondrial frataxin. Frataxin depletion causes impairment in iron-sulfur cluster and heme biosynthesis, disruption of iron homeostasis and hypersensitivity to oxidants. Currently no pharmacological treatment blocks disease progression, although antioxidant therapies proved to benefit patients. We show that sensitivity of yeast frataxin-deficient cells to hydrogen peroxide is partially mediated by the metacaspase. Metacaspase deletion in frataxin-deficient cells results in recovery of antioxidant capacity and heme synthesis. In addition, our results suggest that metacaspase is associated with mitochondrial respiration, intracellular redox control and genomic stability.
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Affiliation(s)
- Sophie Lefevre
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod, CNRS-Université Paris-Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
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40
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Palomo GM, Cerrato T, Gargini R, Diaz-Nido J. Silencing of frataxin gene expression triggers p53-dependent apoptosis in human neuron-like cells. Hum Mol Genet 2011; 20:2807-22. [PMID: 21531789 DOI: 10.1093/hmg/ddr187] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Friedreich's ataxia (FRDA) is an autosomal recessive disease caused by mutations that produce a deficiency in frataxin. Despite the importance of neurodegeneration in FRDA, little is known about the consequences of frataxin deficiency in neuronal cells. Here we describe a neuronal cell model for FRDA based on the use of lentiviral vectors that carry minigenes encoding frataxin-specific shRNAs that silence the expression of this gene. These lentivectors can knockdown frataxin expression in human neuroblastoma SH-SY5Y cells, which results in large-scale cell death in differentiated neuron-like cells but not in undifferentiated neuroblastoma cells. Frataxin-deficient neuron-like cells appear to die through apoptosis that is accompanied by up-regulation of p53, PUMA and Bax and activation of caspase-3. No significant autophagy is observed in frataxin-deficient neuron-like cells and the pharmacological activation of autophagy does not significantly increase neuronal cell death in response to the frataxin deficiency. Cell death triggered by frataxin knockdown can be impaired by interference with p53, caspase inhibitors and gene transfer of FXN. These results suggest that frataxin gene silencing in human neuron-like cells may constitute a useful cell model to characterize the molecular changes triggered by frataxin deficiency in neurons, as well as to search for therapies that may protect against neurodegeneration.
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Affiliation(s)
- Gloria M Palomo
- Departamento de Biología Molecular and Centro de Biología Molecular Severo Ochoa (UAM-CSIC), C/NicolásCabrera 1, Campus de Cantoblanco, Universidad Autónoma de Madrid, Madrid, Spain
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Xu XM, Møller SG. Iron-sulfur clusters: biogenesis, molecular mechanisms, and their functional significance. Antioxid Redox Signal 2011; 15:271-307. [PMID: 20812788 DOI: 10.1089/ars.2010.3259] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Iron-sulfur clusters [Fe-S] are small, ubiquitous inorganic cofactors representing one of the earliest catalysts during biomolecule evolution and are involved in fundamental biological reactions, including regulation of enzyme activity, mitochondrial respiration, ribosome biogenesis, cofactor biogenesis, gene expression regulation, and nucleotide metabolism. Although simple in structure, [Fe-S] biogenesis requires complex protein machineries and pathways for assembly. [Fe-S] are assembled from cysteine-derived sulfur and iron onto scaffold proteins followed by transfer to recipient apoproteins. Several predominant iron-sulfur biogenesis systems have been identified, including nitrogen fixation (NIF), sulfur utilization factor (SUF), iron-sulfur cluster (ISC), and cytosolic iron-sulfur protein assembly (CIA), and many protein components have been identified and characterized. In eukaryotes ISC is mainly localized to mitochondria, cytosolic iron-sulfur protein assembly to the cytosol, whereas plant sulfur utilization factor is localized mainly to plastids. Because of this spatial separation, evidence suggests cross-talk mediated by organelle export machineries and dual targeting mechanisms. Although research efforts in understanding iron-sulfur biogenesis has been centered on bacteria, yeast, and plants, recent efforts have implicated inappropriate [Fe-S] biogenesis to underlie many human diseases. In this review we detail our current understanding of [Fe-S] biogenesis across species boundaries highlighting evolutionary conservation and divergence and assembling our knowledge into a cellular context.
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Affiliation(s)
- Xiang Ming Xu
- Centre for Organelle Research CORE, University of Stavanger, Norway
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Rufini A, Fortuni S, Arcuri G, Condò I, Serio D, Incani O, Malisan F, Ventura N, Testi R. Preventing the ubiquitin-proteasome-dependent degradation of frataxin, the protein defective in Friedreich's ataxia. Hum Mol Genet 2011; 20:1253-61. [PMID: 21216878 DOI: 10.1093/hmg/ddq566] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Friedreich's ataxia (FRDA) is a devastating orphan disease, with no specific treatment. The disease is caused by reduced expression of the protein frataxin, which results in mitochondrial defects and oxidative damage. Levels of residual frataxin critically affect onset and progression of the disease. Understanding the molecular mechanisms that regulate frataxin stability and degradation may, therefore, be exploited for the design of effective therapeutics. Here we show that frataxin is degraded by the ubiquitin-proteasome system and that K(147) is the critical residue responsible for frataxin ubiquitination and degradation. Accordingly, a K(147)R substitution generates a more stable frataxin. We then disclose a set of lead compounds, computationally selected to target the molecular cleft harboring K(147), that can prevent frataxin ubiquitination and degradation, and increase frataxin levels in cells derived from FRDA patients. Moreover, treatment with these compounds induces substantial recovery of aconitase activity and adenosine-5'-triphosphate levels in FRDA cells. Thus, we provide evidence for the therapeutic potential of directly interfering with the frataxin degradation pathway.
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Affiliation(s)
- Alessandra Rufini
- Laboratory of Signal Transduction, Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
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43
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Koeppen AH, Morral JA, McComb RD, Feustel PJ. The neuropathology of late-onset Friedreich's ataxia. CEREBELLUM (LONDON, ENGLAND) 2011; 10:96-103. [PMID: 21128039 PMCID: PMC4894659 DOI: 10.1007/s12311-010-0235-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Friedreich's ataxia (FRDA) affects very young persons. In a large series, the mean ages of onset and death were 11 and 38 years, respectively. The clinical spectrum of FRDA has expanded after genetic confirmation of the mutation became a routine laboratory test. The main cause of death in juvenile-onset FRDA is cardiomyopathy whereas patients with late-onset are more likely to succumb to neurological disability or an intercurrent illness. Many patients with early onset now survive for 20 years or longer. This study made a systematic comparison of the neuropathology in 14 patients with juvenile onset and long survival, and five patients with late onset and long survival. Mean ages of onset (± standard deviation) were 10 ± 5 and 28 ± 13 years, respectively. Disease durations were 33 ± 11 and 47 ± 11 years, respectively. Cross-sectional areas of the thoracic spinal cord were greatly reduced from the normal state but did not differ between the two groups. Similarly, the neurons of dorsal root ganglia were significantly reduced in size in both juvenile- and late-onset cases of FRDA. The dentate nucleus showed severe loss of neurons as well as modification and destruction of corticonuclear terminals in all FRDA patients. Delayed atrophy of the dentate nucleus is the likely cause of the ataxic phenotype of FRDA in late-onset cases, but the reason for the delay is unknown. Frataxin levels in the dentate nucleus of two patients with late onset were similar to those of seven patients with juvenile onset.
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44
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Guccini I, Serio D, Condò I, Rufini A, Tomassini B, Mangiola A, Maira G, Anile C, Fina D, Pallone F, Mongiardi MP, Levi A, Ventura N, Testi R, Malisan F. Frataxin participates to the hypoxia-induced response in tumors. Cell Death Dis 2011; 2:e123. [PMID: 21368894 PMCID: PMC3101705 DOI: 10.1038/cddis.2011.5] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 01/13/2011] [Accepted: 01/19/2011] [Indexed: 01/30/2023]
Abstract
Defective expression of frataxin is responsible for the degenerative disease Friedreich's ataxia. Frataxin is a protein required for cell survival since complete knockout is lethal. Frataxin protects tumor cells against oxidative stress and apoptosis but also acts as a tumor suppressor. The molecular bases of this apparent paradox are missing. We therefore sought to investigate the pathways through which frataxin enhances stress resistance in tumor cells. We found that frataxin expression is upregulated in several tumor cell lines in response to hypoxic stress, a condition often associated with tumor progression. Moreover, frataxin upregulation in response to hypoxia is dependent on hypoxia-inducible factors expression and modulates the activation of the tumor-suppressor p53. Importantly, we show for the first time that frataxin is in fact increased in human tumors in vivo. These results show that frataxin participates to the hypoxia-induced stress response in tumors, thus implying that modulation of its expression could have a critical role in tumor cell survival and/or progression.
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Affiliation(s)
- I Guccini
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - D Serio
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - I Condò
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - A Rufini
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - B Tomassini
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - A Mangiola
- Department of Neurosurgery, Catholic University School of Medicine, Rome, Italy
| | - G Maira
- Department of Neurosurgery, Catholic University School of Medicine, Rome, Italy
| | - C Anile
- Department of Neurosurgery, Catholic University School of Medicine, Rome, Italy
| | - D Fina
- Department of Internal Medicine, University ‘Tor Vergata', Rome, Italy
| | - F Pallone
- Department of Internal Medicine, University ‘Tor Vergata', Rome, Italy
| | - M P Mongiardi
- National Research Council of Italy, Cell Biology and Neurobiology Institute and IRCCS Fondazione Santa Lucia, Rome, Italy
| | - A Levi
- National Research Council of Italy, Cell Biology and Neurobiology Institute and IRCCS Fondazione Santa Lucia, Rome, Italy
| | - N Ventura
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - R Testi
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
| | - F Malisan
- Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata', Rome, Italy
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45
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Gille G, Reichmann H. Iron-dependent functions of mitochondria--relation to neurodegeneration. J Neural Transm (Vienna) 2010; 118:349-59. [PMID: 21161302 DOI: 10.1007/s00702-010-0503-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 10/05/2010] [Indexed: 11/25/2022]
Abstract
A number of neurodegenerative diseases are associated with iron dyshomeostasis and mitochondrial dysfunction. However, the pathomechanistic interplay between iron and mitochondria varies. This review summarises the physiological role of iron in mitochondria and subsequently exemplifies two neurodegenerative diseases with disturbed iron function in mitochondria: inherited Friedreich ataxia (FRDA) and idiopathic Parkinson disease (PD). In eukaryotes, mitochondria are main consumers of iron. The respiratory chain relies on iron-containing redox systems in the form of complexes I-III with iron-sulphur clusters and cytochromes with haem as prosthetic groups. The bifunctional enzyme aconitase is not only important in the citric acid cycle, but also functions as a key regulator of cell iron metabolism. Haem biosynthesis occurs partially in mitochondria as well as the biogenesis of iron-sulphur clusters that are co-factors in numerous iron-sulphur proteins. FRDA is characterised by a mutation of the frataxin gene, the protein of which serves as an iron chaperone in iron-sulphur cluster assembly. The lack of frataxin expression leads to defective iron-sulphur cluster biogenesis with decreased respiratory and aconitase activity. The resulting mitochondrial iron overload might fuel reactive oxygen species formation and contribute to clinical signs of oxidative stress. PD is typically associated with an increased iron content of the substantia nigra, the causes of which are largely unknown. Recent research demonstrated raised iron levels in individual dopaminergic neurons of the substantia nigra. Moreover, transferrin/transferrin receptor 2 mediated transport of iron into the mitochondria of these neurons was identified together with increased transferrin immunoreactivity. Resulting accumulation of iron into mitochondria might lead to oxidative stress damaging iron-sulphur cluster-containing proteins.
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Affiliation(s)
- Gabriele Gille
- Klinik und Poliklinik für Neurologie, TU Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
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46
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Efimova MG, Trottier Y. Distribution of frataxin in eye retina of normal mice and of transgenic R7E mice with retinal degeneration. J EVOL BIOCHEM PHYS+ 2010. [DOI: 10.1134/s0022093010040113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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47
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Santos R, Lefevre S, Sliwa D, Seguin A, Camadro JM, Lesuisse E. Friedreich ataxia: molecular mechanisms, redox considerations, and therapeutic opportunities. Antioxid Redox Signal 2010; 13:651-90. [PMID: 20156111 PMCID: PMC2924788 DOI: 10.1089/ars.2009.3015] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 02/08/2010] [Accepted: 02/14/2010] [Indexed: 12/14/2022]
Abstract
Mitochondrial dysfunction and oxidative damage are at the origin of numerous neurodegenerative diseases like Friedreich ataxia and Alzheimer and Parkinson diseases. Friedreich ataxia (FRDA) is the most common hereditary ataxia, with one individual affected in 50,000. This disease is characterized by progressive degeneration of the central and peripheral nervous systems, cardiomyopathy, and increased incidence of diabetes mellitus. FRDA is caused by a dynamic mutation, a GAA trinucleotide repeat expansion, in the first intron of the FXN gene. Fewer than 5% of the patients are heterozygous and carry point mutations in the other allele. The molecular consequences of the GAA triplet expansion is transcription silencing and reduced expression of the encoded mitochondrial protein, frataxin. The precise cellular role of frataxin is not known; however, it is clear now that several mitochondrial functions are not performed correctly in patient cells. The affected functions include respiration, iron-sulfur cluster assembly, iron homeostasis, and maintenance of the redox status. This review highlights the molecular mechanisms that underlie the disease phenotypes and the different hypothesis about the function of frataxin. In addition, we present an overview of the most recent therapeutic approaches for this severe disease that actually has no efficient treatment.
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Affiliation(s)
- Renata Santos
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Sophie Lefevre
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
- University Pierre et Marie Curie, Paris, France
| | - Dominika Sliwa
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Alexandra Seguin
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Jean-Michel Camadro
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Emmanuel Lesuisse
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
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48
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Erythropoiesis and iron sulfur cluster biogenesis. Adv Hematol 2010; 2010. [PMID: 20862391 PMCID: PMC2939393 DOI: 10.1155/2010/329394] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 06/04/2010] [Accepted: 08/02/2010] [Indexed: 11/22/2022] Open
Abstract
Erythropoiesis in animals is a synchronized process of erythroid cell differentiation that depends on successful acquisition of iron. Heme synthesis depends on iron through its dependence on iron sulfur (Fe-S) cluster biogenesis. Here, we review the relationship between Fe-S biogenesis and heme synthesis in erythropoiesis, with emphasis on the proteins, GLRX5, ABCB7, ISCA, and C1orf69. These Fe-S biosynthesis proteins are highly expressed in erythroid tissues, and deficiency of each of these proteins has been shown to cause anemia in zebrafish model. GLRX5 is involved in the production and ABCB7 in the export of an unknown factor that may function as a gauge of mitochondrial iron status, which may indirectly modulate activity of iron regulatory proteins (IRPs). ALAS2, the enzyme catalyzing the first step in heme synthesis, is translationally controlled by IRPs. GLRX5 may also provide Fe-S cofactor for ferrochelatase, the last enzyme in heme synthesis. ISCA and C1orf69 are thought to assemble Fe-S clusters for mitochondrial aconitase and for lipoate synthase, the enzyme producing lipoate for pyruvate dehydrogenase complex (PDC). PDC and aconitase are involved in the production of succinyl-CoA, a substrate for heme biosynthesis. Thus, many steps of heme synthesis depend on Fe-S cluster assembly.
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49
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Kirstein-Miles J, Morimoto RI. Caenorhabditis elegans as a model system to study intercompartmental proteostasis: Interrelation of mitochondrial function, longevity, and neurodegenerative diseases. Dev Dyn 2010; 239:1529-38. [PMID: 20419784 DOI: 10.1002/dvdy.22292] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The protein quality control system, composed of molecular chaperones and proteases, is of vital importance for the maintenance and function of the proteome and the health of the cell. To achieve this, the cellular proteostasis network integrates the protein folding machinery across all compartments of the eukaryotic cell to enable efficient communication and coordinate a rapid response of folding capacity. Quality control in the mitochondria, however, differs from its cytosolic counterpart due to its prokaryotic origin, and is entirely encoded by the nuclear genome. The control and regulatory cross-talk of mitochondrial function in cellular proteostasis is essential for cellular metabolism, organismal development, and lifespan. Consequently, mitochondrial dysfunction has dramatic effects on the development and progression of a number of neurodegenerative diseases, such as Friedreich's ataxia and Parkinson's disease. Studies using Caenorhabditis elegans as a model system have greatly contributed to our current knowledge of inter-compartmental proteostasis on the cellular and organismal levels.
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Affiliation(s)
- Janine Kirstein-Miles
- Department of Biochemistry, Molecular Biology and Cell Biology, Rice Institute for Biomedical Research, Northwestern University, Evanston, Illinois 60208, USA
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50
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Uhrigshardt H, Singh A, Kovtunovych G, Ghosh M, Rouault TA. Characterization of the human HSC20, an unusual DnaJ type III protein, involved in iron-sulfur cluster biogenesis. Hum Mol Genet 2010; 19:3816-34. [PMID: 20668094 DOI: 10.1093/hmg/ddq301] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The importance of mitochondrial iron-sulfur cluster (ISC) biogenesis for human health has been well established, but the roles of some components of this critical pathway still remain uncharacterized in mammals. Among them is human heat shock cognate protein 20 (hHSC20), the putative human homolog of the specialized DnaJ type co-chaperones, which are crucial for bacterial and fungal ISC assembly. Here, we show that the human HSC20 protein can complement for its counterpart in yeast, Jac1p, and interacts with its proposed human partners, hISCU and hHSPA9. hHSC20 is expressed in various human tissues and localizes mainly to the mitochondria in HeLa cells. However, small amounts were also detected extra-mitochondrially. RNA interference-mediated depletion of hHSC20 specifically reduced the activities of both mitochondrial and cytosolic ISC-containing enzymes. The recovery of inactivated ISC enzymes was markedly delayed after an oxidative insult of hHSC20-deficient cells. Conversely, overexpression of hHSC20 substantially protected cells from oxidative insults. These results imply that hHSC20 is an integral component of the human ISC biosynthetic machinery that is particularly important in the assembly of ISCs under conditions of oxidative stress. A cysteine-rich N-terminal domain, which clearly distinguishes hHSC20 from the specialized DnaJ type III proteins of fungi and most bacteria, was found to be important for the integrity and function of the human co-chaperone.
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Affiliation(s)
- Helge Uhrigshardt
- Molecular Medicine Program, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
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