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Moldovean-Cioroianu NS. Reviewing the Structure-Function Paradigm in Polyglutamine Disorders: A Synergistic Perspective on Theoretical and Experimental Approaches. Int J Mol Sci 2024; 25:6789. [PMID: 38928495 PMCID: PMC11204371 DOI: 10.3390/ijms25126789] [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: 05/16/2024] [Revised: 06/13/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024] Open
Abstract
Polyglutamine (polyQ) disorders are a group of neurodegenerative diseases characterized by the excessive expansion of CAG (cytosine, adenine, guanine) repeats within host proteins. The quest to unravel the complex diseases mechanism has led researchers to adopt both theoretical and experimental methods, each offering unique insights into the underlying pathogenesis. This review emphasizes the significance of combining multiple approaches in the study of polyQ disorders, focusing on the structure-function correlations and the relevance of polyQ-related protein dynamics in neurodegeneration. By integrating computational/theoretical predictions with experimental observations, one can establish robust structure-function correlations, aiding in the identification of key molecular targets for therapeutic interventions. PolyQ proteins' dynamics, influenced by their length and interactions with other molecular partners, play a pivotal role in the polyQ-related pathogenic cascade. Moreover, conformational dynamics of polyQ proteins can trigger aggregation, leading to toxic assembles that hinder proper cellular homeostasis. Understanding these intricacies offers new avenues for therapeutic strategies by fine-tuning polyQ kinetics, in order to prevent and control disease progression. Last but not least, this review highlights the importance of integrating multidisciplinary efforts to advancing research in this field, bringing us closer to the ultimate goal of finding effective treatments against polyQ disorders.
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Affiliation(s)
- Nastasia Sanda Moldovean-Cioroianu
- Institute of Materials Science, Bioinspired Materials and Biosensor Technologies, Kiel University, Kaiserstraße 2, 24143 Kiel, Germany;
- Faculty of Physics, Babeș-Bolyai University, Kogălniceanu 1, RO-400084 Cluj-Napoca, Romania
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2
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Almeida F, Ferreira IL, Naia L, Marinho D, Vilaça-Ferreira AC, Costa MD, Duarte-Silva S, Maciel P, Rego AC. Mitochondrial Dysfunction and Decreased Cytochrome c in Cell and Animal Models of Machado-Joseph Disease. Cells 2023; 12:2397. [PMID: 37830611 PMCID: PMC10571982 DOI: 10.3390/cells12192397] [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: 05/29/2023] [Revised: 09/29/2023] [Accepted: 09/29/2023] [Indexed: 10/14/2023] Open
Abstract
Mitochondrial dysfunction has been described in many neurodegenerative disorders; however, there is less information regarding mitochondrial deficits in Machado-Joseph disease (MJD), a polyglutamine (polyQ) disorder caused by CAG repeat expansion in the ATXN3 gene. In the present study, we characterized the changes in mitochondrial function and biogenesis markers in two MJD models, CMVMJD135 (MJD135) transgenic mice at a fully established phenotype stage and tetracycline-regulated PC6-3 Q108 cell line expressing mutant ataxin-3 (mATXN3). We detected mATXN3 in the mitochondrial fractions of PC6-3 Q108 cells, suggesting the interaction of expanded ATXN3 with the organelle. Interestingly, in both the cerebella of the MJD135 mouse model and in PC6-3 Q108 cells, we found decreased mitochondrial respiration, ATP production and mitochondrial membrane potential, strongly suggesting mitochondrial dysfunction in MJD. Also, in PC6-3 Q108 cells, an additional enhanced glycolytic flux was observed. Supporting the functional deficits observed in MJD mitochondria, MJD135 mouse cerebellum and PC6-3 Q108 cells showed reduced cytochrome c mRNA and protein levels. Overall, our findings show compromised mitochondrial function associated with decreased cytochrome c levels in both cell and animal models of MJD.
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Affiliation(s)
- Filipa Almeida
- CNC-UC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (F.A.); (I.L.F.); (L.N.); (D.M.)
| | - Ildete L. Ferreira
- CNC-UC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (F.A.); (I.L.F.); (L.N.); (D.M.)
- IIIUC-Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
| | - Luana Naia
- CNC-UC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (F.A.); (I.L.F.); (L.N.); (D.M.)
- IIIUC-Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
| | - Daniela Marinho
- CNC-UC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (F.A.); (I.L.F.); (L.N.); (D.M.)
- IIIUC-Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
| | - Ana Catarina Vilaça-Ferreira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (A.C.V.-F.); (M.D.C.); (S.D.-S.)
- ICVS/3B’s-PT Government Associate Laboratory, 4805-017 Guimarães, Portugal
| | - Marta D. Costa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (A.C.V.-F.); (M.D.C.); (S.D.-S.)
- ICVS/3B’s-PT Government Associate Laboratory, 4805-017 Guimarães, Portugal
| | - Sara Duarte-Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (A.C.V.-F.); (M.D.C.); (S.D.-S.)
- ICVS/3B’s-PT Government Associate Laboratory, 4805-017 Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (A.C.V.-F.); (M.D.C.); (S.D.-S.)
- ICVS/3B’s-PT Government Associate Laboratory, 4805-017 Guimarães, Portugal
| | - A. Cristina Rego
- CNC-UC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (F.A.); (I.L.F.); (L.N.); (D.M.)
- FMUC-Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
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3
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Transcription factor EB-mediated mesenchymal stem cell therapy induces autophagy and alleviates spinocerebellar ataxia type 3 defects in neuronal cells model. Cell Death Dis 2022; 13:622. [PMID: 35851059 PMCID: PMC9293975 DOI: 10.1038/s41419-022-05085-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/04/2022] [Accepted: 07/07/2022] [Indexed: 01/21/2023]
Abstract
Defects in ataxin-3 proteins and CAG repeat expansions in its coding gene ATXN3 cause Spinocerebellar Ataxia Type 3 (SCA3) or Machado-Joseph disease (MJD) polyglutamine neurodegenerative disease. The mutant proteins aggregate as inclusion bodies in cells and compete with wild-type ataxin-3, which leads to neuronal dysfunction or death and impairs Beclin1-mediated autophagy. It has been reported that Mesenchymal stem cells (MSCs) can reliably treat several neurodegenerative diseases. Herein, we used a Transcription Factor EB (TFEB) nuclear translocation-mediated MSCs co-culture approach to reconstitute autophagy and lysosomal biogenesis, and reduce SCA3-like behaviors in induced pluripotent stem cells (iPSCs)-derived neuron cells models. Our iPSCs model showed enhanced expression of autophagy proteins, attenuated the expression and toxic effects of mutant ataxin-3 on neurons, and alleviated the effects of ataxin-3 on autophagy. Therefore, MSCs are associated with autophagy-inducing therapy and compared to animal models, our MSCs co-culture could be used as a novel and potential therapeutic approach to study SCA3 disease and other neurodegenerative diseases.
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Coelho P, Fão L, Mota S, Rego AC. Mitochondrial function and dynamics in neural stem cells and neurogenesis: Implications for neurodegenerative diseases. Ageing Res Rev 2022; 80:101667. [PMID: 35714855 DOI: 10.1016/j.arr.2022.101667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 05/21/2022] [Accepted: 06/09/2022] [Indexed: 11/28/2022]
Abstract
Mitochondria have been largely described as the powerhouse of the cell and recent findings demonstrate that this organelle is fundamental for neurogenesis. The mechanisms underlying neural stem cells (NSCs) maintenance and differentiation are highly regulated by both intrinsic and extrinsic factors. Mitochondrial-mediated switch from glycolysis to oxidative phosphorylation, accompanied by mitochondrial remodeling and dynamics are vital to NSCs fate. Deregulation of mitochondrial proteins, mitochondrial DNA, function, fission/fusion and metabolism underly several neurodegenerative diseases; data show that these impairments are already present in early developmental stages and NSC fate decisions. However, little is known about mitochondrial role in neurogenesis. In this Review, we describe the recent evidence covering mitochondrial role in neurogenesis, its impact in selected neurodegenerative diseases, for which aging is the major risk factor, and the recent advances in stem cell-based therapies that may alleviate neurodegenerative disorders-related neuronal deregulation through improvement of mitochondrial function and dynamics.
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Affiliation(s)
- Patrícia Coelho
- CNC, Center for Neuroscience and Cell Biology, University of Coimbra Polo 1, Coimbra, Portugal.
| | - Lígia Fão
- CNC, Center for Neuroscience and Cell Biology, University of Coimbra Polo 1, Coimbra, Portugal; FMUC- Faculty of Medicine, University of Coimbra Polo 3, Coimbra, Portugal.
| | - Sandra Mota
- CNC, Center for Neuroscience and Cell Biology, University of Coimbra Polo 1, Coimbra, Portugal; III, Institute of Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.
| | - A Cristina Rego
- CNC, Center for Neuroscience and Cell Biology, University of Coimbra Polo 1, Coimbra, Portugal; FMUC- Faculty of Medicine, University of Coimbra Polo 3, Coimbra, Portugal.
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Mitochondrial Dysfunction in Spinocerebellar Ataxia Type 3 Is Linked to VDAC1 Deubiquitination. Int J Mol Sci 2022; 23:ijms23115933. [PMID: 35682609 PMCID: PMC9180688 DOI: 10.3390/ijms23115933] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/06/2022] [Accepted: 05/23/2022] [Indexed: 01/01/2023] Open
Abstract
Dysfunctional mitochondria are linked to several neurodegenerative diseases. Metabolic defects, a symptom which can result from dysfunctional mitochondria, are also present in spinocerebellar ataxia type 3 (SCA3), also known as Machado–Joseph disease, the most frequent, dominantly inherited neurodegenerative ataxia worldwide. Mitochondrial dysfunction has been reported for several neurodegenerative disorders and ataxin-3 is known to deubiquitinylate parkin, a key protein required for canonical mitophagy. In this study, we analyzed mitochondrial function and mitophagy in a patient-derived SCA3 cell model. Human fibroblast lines isolated from SCA3 patients were immortalized and characterized. SCA3 patient fibroblasts revealed circular, ring-shaped mitochondria and featured reduced OXPHOS complexes, ATP production and cell viability. We show that wildtype ataxin-3 deubiquitinates VDAC1 (voltage-dependent anion channel 1), a member of the mitochondrial permeability transition pore and a parkin substrate. In SCA3 patients, VDAC1 deubiquitination and parkin recruitment to the depolarized mitochondria is inhibited. Increased p62-linked mitophagy, autophagosome formation and autophagy is observed under disease conditions, which is in line with mitochondrial fission. SCA3 fibroblast lines demonstrated a mitochondrial phenotype and dysregulation of parkin-VDAC1-mediated mitophagy, thereby promoting mitochondrial quality control via alternative pathways.
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Anti-Excitotoxic Effects of N-Butylidenephthalide Revealed by Chemically Insulted Purkinje Progenitor Cells Derived from SCA3 iPSCs. Int J Mol Sci 2022; 23:ijms23031391. [PMID: 35163312 PMCID: PMC8836169 DOI: 10.3390/ijms23031391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/15/2022] [Accepted: 01/17/2022] [Indexed: 12/04/2022] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is characterized by the over-repetitive CAG codon in the ataxin-3 gene (ATXN3), which encodes the mutant ATXN3 protein. The pathological defects of SCA3 such as the impaired aggresomes, autophagy, and the proteasome have been reported previously. To date, no effective treatment is available for SCA3 disease. This study aimed to study anti-excitotoxic effects of n-butylidenephthalide by chemically insulted Purkinje progenitor cells derived from SCA3 iPSCs. We successfully generated Purkinje progenitor cells (PPs) from SCA3 patient-derived iPSCs. The PPs, expressing both neural and Purkinje progenitor's markers, were acquired after 35 days of differentiation. In comparison with the PPs derived from control iPSCs, SCA3 iPSCs-derived PPs were more sensitive to the excitotoxicity induced by quinolinic acid (QA). The observations of QA-treated SCA3 PPs showing neural degeneration including neurite shrinkage and cell number decrease could be used to quickly and efficiently identify drug candidates. Given that the QA-induced neural cell death of SCA3 PPs was established, the activity of calpain in SCA3 PPs was revealed. Furthermore, the expression of cleaved poly (ADP-ribose) polymerase 1 (PARP1), a marker of apoptotic pathway, and the accumulation of ATXN3 proteolytic fragments were observed. When SCA3 PPs were treated with n-butylidenephthalide (n-BP), upregulated expression of calpain 2 and concurrent decreased level of calpastatin could be reversed, and the overall calpain activity was accordingly suppressed. Such findings reveal that n-BP could not only inhibit the cleavage of ATXN3 but also protect the QA-induced excitotoxicity from the Purkinje progenitor loss.
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Chung JK, Ahn YM, Kim SA, Joo EJ. Differences in mitochondrial DNA copy number between patients with bipolar I and II disorders. J Psychiatr Res 2022; 145:325-333. [PMID: 33190840 DOI: 10.1016/j.jpsychires.2020.11.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/08/2020] [Accepted: 11/05/2020] [Indexed: 02/01/2023]
Abstract
Mitochondria play a critical role in energy metabolism. Genetic, postmortem brain, and brain imaging studies of bipolar disorder (BD) patients indicated that mitochondrial dysfunction might explain BD pathophysiology. Mitochondrial function can be indirectly evaluated by measuring mitochondrial DNA (mtDNA) copy numbers. We recruited 186 bipolar I disorder (BD1) and 95 bipolar II disorder (BD2) patients, and age- and sex-matched controls. MtDNA copy numbers in peripheral blood cells were measured via quantitative polymerase chain reaction. We explored parameters (including age and clinical features) that might affect mtDNA copy numbers. We found that BD1 patients had a lower mtDNA copy number than controls and that mtDNA copy number was negatively associated with the number of mood episodes. BD2 patients had a higher mtDNA copy number than controls. Thus, changes in mitochondrial function may influence BD pathophysiology. The opposite directions of the association with mtDNA copy number in BD1 and BD2 patients suggests that the difference in pathophysiology may be associated with mitochondrial function.
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Affiliation(s)
- Jae Kyung Chung
- Department of Psychiatry, Eumsung-somang Hospital, Eumsung, Republic of Korea
| | - Yong Min Ahn
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea; Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea; Institute of Human Behavioral Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Soon Ae Kim
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, Republic of Korea.
| | - Eun-Jeong Joo
- Department of Neuropsychiatry, School of Medicine, Eulji University, Daejeon, Republic of Korea; Department of Psychiatry, Nowon Eulji Medical Center, Eulji University, Seoul, Republic of Korea.
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Traa A, Machiela E, Rudich PD, Soo SK, Senchuk MM, Van Raamsdonk JM. Identification of Novel Therapeutic Targets for Polyglutamine Diseases That Target Mitochondrial Fragmentation. Int J Mol Sci 2021; 22:ijms222413447. [PMID: 34948242 PMCID: PMC8703635 DOI: 10.3390/ijms222413447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/06/2021] [Accepted: 12/09/2021] [Indexed: 12/15/2022] Open
Abstract
Huntington’s disease (HD) is one of at least nine polyglutamine diseases caused by a trinucleotide CAG repeat expansion, all of which lead to age-onset neurodegeneration. Mitochondrial dynamics and function are disrupted in HD and other polyglutamine diseases. While multiple studies have found beneficial effects from decreasing mitochondrial fragmentation in HD models by disrupting the mitochondrial fission protein DRP1, disrupting DRP1 can also have detrimental consequences in wild-type animals and HD models. In this work, we examine the effect of decreasing mitochondrial fragmentation in a neuronal C. elegans model of polyglutamine toxicity called Neur-67Q. We find that Neur-67Q worms exhibit mitochondrial fragmentation in GABAergic neurons and decreased mitochondrial function. Disruption of drp-1 eliminates differences in mitochondrial morphology and rescues deficits in both movement and longevity in Neur-67Q worms. In testing twenty-four RNA interference (RNAi) clones that decrease mitochondrial fragmentation, we identified eleven clones—each targeting a different gene—that increase movement and extend lifespan in Neur-67Q worms. Overall, we show that decreasing mitochondrial fragmentation may be an effective approach to treating polyglutamine diseases and we identify multiple novel genetic targets that circumvent the potential negative side effects of disrupting the primary mitochondrial fission gene drp-1.
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Affiliation(s)
- Annika Traa
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada; (A.T.); (P.D.R.); (S.K.S.)
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Emily Machiela
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA; (E.M.); (M.M.S.)
| | - Paige D. Rudich
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada; (A.T.); (P.D.R.); (S.K.S.)
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Sonja K. Soo
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada; (A.T.); (P.D.R.); (S.K.S.)
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Megan M. Senchuk
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA; (E.M.); (M.M.S.)
| | - Jeremy M. Van Raamsdonk
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada; (A.T.); (P.D.R.); (S.K.S.)
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA; (E.M.); (M.M.S.)
- Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Correspondence:
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McIntosh CS, Li D, Wilton SD, Aung-Htut MT. Polyglutamine Ataxias: Our Current Molecular Understanding and What the Future Holds for Antisense Therapies. Biomedicines 2021; 9:1499. [PMID: 34829728 PMCID: PMC8615177 DOI: 10.3390/biomedicines9111499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 02/07/2023] Open
Abstract
Polyglutamine (polyQ) ataxias are a heterogenous group of neurological disorders all caused by an expanded CAG trinucleotide repeat located in the coding region of each unique causative gene. To date, polyQ ataxias encompass six disorders: spinocerebellar ataxia types 1, 2, 3, 6, 7, and 17 and account for a larger group of disorders simply known as polyglutamine disorders, which also includes Huntington's disease. These diseases are typically characterised by progressive ataxia, speech and swallowing difficulties, lack of coordination and gait, and are unfortunately fatal in nature, with the exception of SCA6. All the polyQ spinocerebellar ataxias have a hallmark feature of neuronal aggregations and share many common pathogenic mechanisms, such as mitochondrial dysfunction, impaired proteasomal function, and autophagy impairment. Currently, therapeutic options are limited, with no available treatments that slow or halt disease progression. Here, we discuss the common molecular and clinical presentations of polyQ spinocerebellar ataxias. We will also discuss the promising antisense oligonucleotide therapeutics being developed as treatments for these devastating diseases. With recent advancements and therapeutic approvals of various antisense therapies, it is envisioned that some of the studies reviewed may progress into clinical trials and beyond.
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Affiliation(s)
- Craig S. McIntosh
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Dunhui Li
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Steve D. Wilton
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - May T. Aung-Htut
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
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Elstner M, Olszewski K, Prokisch H, Klopstock T, Murgia M. Multi-Omics Approach to Mitochondrial DNA Damage in Human Muscle Fibers. Int J Mol Sci 2021; 22:ijms222011080. [PMID: 34681740 PMCID: PMC8537949 DOI: 10.3390/ijms222011080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial DNA deletions affect energy metabolism at tissue-specific and cell-specific threshold levels, but the pathophysiological mechanisms determining cell fate remain poorly understood. Chronic progressive external ophthalmoplegia (CPEO) is caused by mtDNA deletions and characterized by a mosaic distribution of muscle fibers with defective cytochrome oxidase (COX) activity, interspersed among fibers with retained functional respiratory chain. We used diagnostic histochemistry to distinguish COX-negative from COX-positive fibers in nine muscle biopsies from CPEO patients and performed laser capture microdissection (LCM) coupled to genome-wide gene expression analysis. To gain molecular insight into the pathogenesis, we applied network and pathway analysis to highlight molecular differences of the COX-positive and COX-negative fiber transcriptome. We then integrated our results with proteomics data that we previously obtained comparing COX-positive and COX-negative fiber sections from three other patients. By virtue of the combination of LCM and a multi-omics approach, we here provide a comprehensive resource to tackle the pathogenic changes leading to progressive respiratory chain deficiency and disease in mitochondrial deletion syndromes. Our data show that COX-negative fibers upregulate transcripts involved in translational elongation and protein synthesis. Furthermore, based on functional annotation analysis, we find that mitochondrial transcripts are the most enriched among those with significantly different expression between COX-positive and COX-negative fibers, indicating that our unbiased large-scale approach resolves the core of the pathogenic changes. Further enrichments include transcripts encoding LIM domain proteins, ubiquitin ligases, proteins involved in RNA turnover, and, interestingly, cell cycle arrest and cell death. These pathways may thus have a functional association to the molecular pathogenesis of the disease. Overall, the transcriptome and proteome show a low degree of correlation in CPEO patients, suggesting a relevant contribution of post-transcriptional mechanisms in shaping this disease phenotype.
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Affiliation(s)
- Matthias Elstner
- Department of Neurology, Technical University Munich, 81675 Munich, Germany;
| | - Konrad Olszewski
- Center for Addictive Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, 8001 Zurich, Switzerland;
| | - Holger Prokisch
- Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany;
- Institute of Neurogenomics, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University of Munich, 80336 Munich, Germany;
- German Center for Neurodegenerative Diseases (DZNE), 81675 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81675 Munich, Germany
| | - Marta Murgia
- Department of Proteomics a Signal Transduction, Max Planck Institute of Biochemistry, 82352 Martinsried, Germany
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Correspondence:
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11
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Raj K, Akundi RS. Mutant Ataxin-3-Containing Aggregates (MATAGGs) in Spinocerebellar Ataxia Type 3: Dynamics of the Disorder. Mol Neurobiol 2021; 58:3095-3118. [PMID: 33629274 DOI: 10.1007/s12035-021-02314-z] [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: 10/11/2020] [Accepted: 01/25/2021] [Indexed: 11/25/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is the most common type of SCA worldwide caused by abnormal polyglutamine expansion in the coding region of the ataxin-3 gene. Ataxin-3 is a multi-faceted protein involved in various cellular processes such as deubiquitination, cytoskeletal organisation, and transcriptional regulation. The presence of an expanded poly(Q) stretch leads to altered processing and misfolding of the protein culminating in the production of insoluble protein aggregates in the cell. Various post-translational modifications affect ataxin-3 fibrillation and aggregation. This review provides an exhaustive assessment of the various pathogenic mechanisms undertaken by the mutant ataxin-3-containing aggregates (MATAGGs) for disease induction and neurodegeneration. This includes in-depth discussion on MATAGG dynamics including their formation, role in neuronal pathogenesis, and the debate over the toxic v/s protective nature of the MATAGGs in disease progression. Additionally, the currently available therapeutic strategies against SCA3 have been reviewed. The shift in the focus of such strategies, from targeting the steps that lead to or reduce aggregate formation to targeting the expression of mutant ataxin-3 itself via RNA-based therapeutics, has also been presented. We also discuss the intriguing promise that various growth and neurotrophic factors, especially the insulin pathway, hold in the modulation of SCA3 progression. These emerging areas show the newer directions through which SCA3 can be targeted including various preclinical and clinical trials. All these advances made in the last three decades since the discovery of the ataxin-3 gene have been critically reviewed here.
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Affiliation(s)
- Kritika Raj
- Neuroinflammation Research Lab, Faculty of Life Sciences and Biotechnology, South Asian University, Chanakyapuri, New Delhi, 110021, India
| | - Ravi Shankar Akundi
- Neuroinflammation Research Lab, Faculty of Life Sciences and Biotechnology, South Asian University, Chanakyapuri, New Delhi, 110021, India.
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12
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Ding D, Wang C, Chen Z, Xia K, Tang B, Qiu R, Jiang H. Polyglutamine-expanded ataxin3 alter specific gene expressions through changing DNA methylation status in SCA3/MJD. Aging (Albany NY) 2020; 13:3680-3698. [PMID: 33411688 PMCID: PMC7906150 DOI: 10.18632/aging.202331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/27/2020] [Indexed: 11/25/2022]
Abstract
DNA methylation has recently been linked to transcriptional dysregulation and neuronal dysfunction in polyglutamine (polyQ) disease. This study aims to determine whether (CAG)n expansion in ATXN3 perturbs DNA methylation status and affects gene expression. We analyzed DNA methylation throughout the genome using reduced representation bisulfite sequencing (RRBS) and confirmed the results using MethylTarget sequencing. Dynamic changes in DNA methylation, transcriptional and translational levels of specific genes were detected using BSP, qRT-PCR and western blot. In total, 135 differentially methylated regions (DMRs) were identified between SCA3/MJD and WT mouse cerebellum. KEGG analysis revealed differentially methylated genes involved in amino acid metabolism, Hedgehog signaling pathway, thyroid cancer, tumorigenesis and other pathways. We focused on DMRs that were directly associated with gene expression. On this basis, we further assessed 7 genes, including 13 DMRs, for DNA methylation validation and gene expression. We found that the methylation status of the DMRs of En1 and Nkx2-1 was negatively associated with their transcriptional and translational levels and that alteration of the DNA methylation status of DMRs and the corresponding transcription occurred before dyskinesia in SCA3/MJD mice. These results revealed novel DNA methylation-regulated genes, En1 and Nkx2-1, which may be useful for understanding the pathogenesis of SCA3/MJD.
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Affiliation(s)
- Dongxue Ding
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China
| | - Chunrong Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China
| | - Zhao Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China
| | - Kun Xia
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.,State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, P.R. China.,National Clinical Research Center for Geriatric Diseases, Changsha, Hunan, P. R. China
| | - Rong Qiu
- School of Information Science and Engineering, Central South University, Changsha, China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.,State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, P.R. China.,National Clinical Research Center for Geriatric Diseases, Changsha, Hunan, P. R. China
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13
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Visioli F, Rodríguez-Pérez M, Gómez-Torres Ó, Pintado-Losa C, Burgos-Ramos E. Hydroxytyrosol improves mitochondrial energetics of a cellular model of Alzheimer's disease. Nutr Neurosci 2020; 25:990-1000. [PMID: 33023416 DOI: 10.1080/1028415x.2020.1829344] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mitochondrial energetic deficit is one of the hallmarks of neurodegenerative disorders, e.g. Alzheimer´s disease (AD). Adherence to a Mediterranean diet is associated with lower incidence of cognitive decline and AD and extra virgin olive oil's (poly)phenols such as oleuropein and hydroxytyrosol (HT) are being actively studied in this respect. In this study, we assessed the effects of HT on mitochondrial energetic dysfunction in the 7PA2 cells cellular model, i.e. one of the best cellular models of Aβ toxicity with a well-characterized mitochondrial dysfunction typically observed in AD. We report an increase of new mitochondria at 8 h post HT-treatment, which was followed by higher mitochondrial fusion. Further, ATP concentrations were significantly increased after 24 h of treatment with HT as compared with controls. Our data suggest that HT may revert the energetic deficit of a cellular model of AD by potentiating mitochondrial activity. Because HT is being proposed as dietary supplement or component of functional foods, future studies in appropriate animal models and - eventually - humans are warranted to further investigate its potential neuroprotective actions in AD.
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Affiliation(s)
- Francesco Visioli
- Department of Molecular Medicine, University of Padova, Padua, Italy.,IMDEA-Food, CEI UAM+CSIC, Madrid, Spain
| | - María Rodríguez-Pérez
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Óscar Gómez-Torres
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Cristina Pintado-Losa
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Emma Burgos-Ramos
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Toledo, Spain
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14
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Duarte Lobo D, Nobre RJ, Oliveira Miranda C, Pereira D, Castelhano J, Sereno J, Koeppen A, Castelo-Branco M, Pereira de Almeida L. The blood-brain barrier is disrupted in Machado-Joseph disease/spinocerebellar ataxia type 3: evidence from transgenic mice and human post-mortem samples. Acta Neuropathol Commun 2020; 8:152. [PMID: 32867861 PMCID: PMC7457506 DOI: 10.1186/s40478-020-00955-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 05/25/2020] [Indexed: 12/20/2022] Open
Abstract
Blood-brain barrier (BBB) disruption is a common feature in neurodegenerative diseases. However, BBB integrity has not been assessed in spinocerebellar ataxias (SCAs) such as Machado-Joseph disease/SCA type 3 (MJD/SCA3), a genetic disorder, triggered by polyglutamine-expanded ataxin-3. To investigate that, BBB integrity was evaluated in a transgenic mouse model of MJD and in human post-mortem brain tissues. Firstly, we investigated the BBB permeability in MJD mice by: i) assessing the extravasation of the Evans blue (EB) dye and blood-borne proteins (e.g fibrinogen) in the cerebellum by immunofluorescence, and ii) in vivo Dynamic Contrast Enhanced-Magnetic Resonance Imaging (DCE-MRI). The presence of ataxin-3 aggregates in brain blood vessels and the levels of tight junction (TJ)-associated proteins were also explored by immunofluorescence and western blotting. Human brain samples were used to confirm BBB permeability by evaluating fibrinogen extravasation, co-localization of ataxin-3 aggregates with brain blood vessels and neuroinflammation. In the cerebellum of the mouse model of MJD, there was a 5-fold increase in EB accumulation when compared to age-matched controls. Moreover, vascular permeability displayed a 13-fold increase demonstrated by DCE-MRI. These results were validated by the 2-fold increase in fibrinogen extravasation in transgenic animals comparing to controls. Interestingly, mutant ataxin-3 aggregates were detected in cerebellar blood vessels of transgenic mice, accompanied by alterations of TJ-associated proteins in cerebellar endothelial cells, namely a 29% decrease in claudin-5 oligomers and a 10-fold increase in an occludin cleavage fragment. These results were validated in post-mortem brain samples from MJD patients as we detected fibrinogen extravasation across BBB, the presence of ataxin-3 aggregates in blood vessels and associated microgliosis. Altogether, our results prove BBB impairment in MJD/SCA3. These findings contribute for a better understanding of the disease mechanisms and opens the opportunity to treat MJD with medicinal products that in normal conditions would not cross the BBB.
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15
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Yuan H, Yang H, Peng L, Peng Y, Chen Z, Wan L, Wang C, Shi Y, Zhang VW, Tang B, Qiu R, Jiang H. Profiling of mitochondrial genomes in SCA3/MJD patients from mainland China. Gene 2020; 738:144487. [PMID: 32087274 DOI: 10.1016/j.gene.2020.144487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/15/2020] [Accepted: 02/19/2020] [Indexed: 02/08/2023]
Abstract
Spinocerebellar ataxia type 3, also known as Machado-Joseph disease (SCA3/MJD), is the most common type of autosomal dominant cerebellar ataxias. Few studies focused on the changes of the whole mitochondrial genomes of SCA3/MJD patients and its relationship with the pathogenesis of SCA3/MJD. We adapted one-step long-range PCR to amplify the entire mitochondrial DNA (mtDNA) followed by next-generation sequencing technology to investigate the information of whole mitochondrial genomes in 38 SCA3/MJD patients and 31 healthy controls from mainland China. Compared to the healthy control group, the mitochondrial variations in SCA3/MJD patients were more concentrated in the tRNA-transcribed genes which were further found to be potentially associated with the pathogenesis of SCA3/MJD by SKAT-O analysis. However, owning variations in tRNA-transcribed genes could not affect the age of onset (AO) of SCA3/MJD patients. We also noticed that the variant loads greater than 90% took up more in SCA3/MJD patients than in controls. Moreover, from our preliminary study, compared to the patients whose ages of onset were elder than 20, the mitochondrial genomes showed no difference in those AO less than 20. This is the first study to demonstrate the feasibility of using the next-generation sequencing technology for mtDNA variant analysis of SCA3/MJD patients from mainland China. And this research enriches the genetic information of SCA3/MJD and provides a direction for further investigations about the mitochondrial genomes in SCA3/MJD.
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Affiliation(s)
- Hongyu Yuan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Huihua Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Linliu Peng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yun Peng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhao Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Linlin Wan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Chunrong Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yuting Shi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Victor Wei Zhang
- AmCare Genomics Laboratory, Guangzhou, China; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China; National Clinical Research Center for Geriatric Diseases, Central South University, Changsha, Hunan, China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, China; Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China
| | - Rong Qiu
- School of Computer Science and Engineering, Central South University, Changsha, China.
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China; National Clinical Research Center for Geriatric Diseases, Central South University, Changsha, Hunan, China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan, China; Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China; Xinjiang Medical University, Urumchi, Xinjiang, China.
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16
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McLoughlin HS, Moore LR, Paulson HL. Pathogenesis of SCA3 and implications for other polyglutamine diseases. Neurobiol Dis 2020; 134:104635. [PMID: 31669734 PMCID: PMC6980715 DOI: 10.1016/j.nbd.2019.104635] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/30/2019] [Accepted: 10/03/2019] [Indexed: 12/14/2022] Open
Abstract
Tandem repeat diseases include the neurodegenerative disorders known as polyglutamine (polyQ) diseases, caused by CAG repeat expansions in the coding regions of the respective disease genes. The nine known polyQ disease include Huntington's disease (HD), dentatorubral-pallidoluysian atrophy (DRPLA), spinal bulbar muscular atrophy (SBMA), and six spinocerebellar ataxias (SCA1, SCA2, SCA3, SCA6, SCA7, and SCA17). The underlying disease mechanism in the polyQ diseases is thought principally to reflect dominant toxic properties of the disease proteins which, when harboring a polyQ expansion, differentially interact with protein partners and are prone to aggregate. Among the polyQ diseases, SCA3 is the most common SCA, and second to HD in prevalence worldwide. Here we summarize current understanding of SCA3 disease mechanisms within the broader context of the broader polyQ disease field. We emphasize properties of the disease protein, ATXN3, and new discoveries regarding three potential pathogenic mechanisms: 1) altered protein homeostasis; 2) DNA damage and dysfunctional DNA repair; and 3) nonneuronal contributions to disease. We conclude with an overview of the therapeutic implications of recent mechanistic insights.
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Affiliation(s)
| | - Lauren R Moore
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
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17
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Chung JK, Lee SY, Park M, Joo EJ, Kim SA. Investigation of mitochondrial DNA copy number in patients with major depressive disorder. Psychiatry Res 2019; 282:112616. [PMID: 31639552 DOI: 10.1016/j.psychres.2019.112616] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/25/2019] [Accepted: 10/13/2019] [Indexed: 12/24/2022]
Abstract
Mitochondrial dysfunction is implicated in the pathophysiology of major depressive disorder (MDD). This dysfunction can be indirectly assessed using the mitochondrial DNA (mtDNA) copy number. A total of 118 patients with MDD and 116 age- and sex-matched control subjects were recruited for this study, and mtDNA copy numbers were measured in peripheral blood cells. This study also examined the potential variables that might impact mtDNA copy number in MDD, including age and clinical features. Additionally, epigenetic control of mtDNA copy number was examined by assessing DNA methylation ratios in the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) promoter in nuclear DNA and the displacement loop (D-loop) region of mtDNA. The present results showed that patients with MDD had a higher mtDNA copy number and a decreased DNA methylation status in the PGC1α promoter. mtDNA copy numbers were negatively associated with an age, psychomotor agitation, and somatic symptoms in MDD. These results suggest that the alterations in mitochondrial function and epigenetic change of PGC1α may be relevant to the pathophysiology of MDD.
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Affiliation(s)
- Jae Kyung Chung
- Department of Psychiatry, Eumsung-somang Hospital, Eumsung, Republic of Korea
| | - Soo Young Lee
- Department of Pharmacology, School of Medicine, Eulji University, 77, Gyeryong-ro 771 beon-gil, Jung-gu, Daejeon 34824, Republic of Korea
| | - Mira Park
- Department of Preventive Medicine, School of Medicine, Eulji University, Daejeon, Republic of Korea
| | - Eun-Jeong Joo
- Department of Neuropsychiatry, School of Medicine, Eulji University, Daejeon, Republic of Korea; Department of Neuropsychiatry, Department of Psychiatry, Nowon Eulji Medical Center, Eulji University, 68 Hangeulbiseokro, Nowon-Gu, 01830 Seoul, Republic of Korea.
| | - Soon Ae Kim
- Department of Pharmacology, School of Medicine, Eulji University, 77, Gyeryong-ro 771 beon-gil, Jung-gu, Daejeon 34824, Republic of Korea.
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18
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Da Silva JD, Teixeira-Castro A, Maciel P. From Pathogenesis to Novel Therapeutics for Spinocerebellar Ataxia Type 3: Evading Potholes on the Way to Translation. Neurotherapeutics 2019; 16:1009-1031. [PMID: 31691128 PMCID: PMC6985322 DOI: 10.1007/s13311-019-00798-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD), is a neurodegenerative disorder caused by a polyglutamine expansion in the ATXN3 gene. In spite of the identification of a clear monogenic cause 25 years ago, the pathological process still puzzles researchers, impairing prospects for an effective therapy. Here, we propose the disruption of protein homeostasis as the hub of SCA3 pathogenesis, being the molecular mechanisms and cellular pathways that are deregulated in SCA3 downstream consequences of the misfolding and aggregation of ATXN3. Moreover, we attempt to provide a realistic perspective on how the translational/clinical research in SCA3 should evolve. This was based on molecular findings, clinical and epidemiological characteristics, studies of proposed treatments in other conditions, and how that information is essential for their (re-)application in SCA3. This review thus aims i) to critically evaluate the current state of research on SCA3, from fundamental to translational and clinical perspectives; ii) to bring up the current key questions that remain unanswered in this disorder; and iii) to provide a frame on how those answers should be pursued.
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Affiliation(s)
- Jorge Diogo Da Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
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19
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Kim JI, Lee SY, Park M, Kim SY, Kim JW, Kim SA, Kim BN. Peripheral Mitochondrial DNA Copy Number is Increased in Korean Attention-Deficit Hyperactivity Disorder Patients. Front Psychiatry 2019; 10:506. [PMID: 31379624 PMCID: PMC6656858 DOI: 10.3389/fpsyt.2019.00506] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 06/27/2019] [Indexed: 01/10/2023] Open
Abstract
The involvement of mitochondrial dysfunction in the pathophysiology of attention-deficit hyperactivity disorder (ADHD) has been suggested in several reports. Mitochondrial DNA (mtDNA) copy number as well as methylation of the D-loop region and peroxisome-proliferator-activated receptor γ co-activator-1α (PPARGC1A) are considered biomarkers for mitochondrial dysfunction. We compared the mtDNA copy number and methylation ratio of the D-loop region and PPARGC1A between ADHD patients and controls and also among ADHD subtypes. The present study included 70 subjects with ADHD and 70 age- and gender-matched healthy controls (HCs). We measured the relative mtDNA copy number in peripheral blood cells using quantitative polymerase chain reaction (qPCR), and the methylation ratio was measured using methylation-specific PCR (MSP) after bisulfite conversion. The relative mtDNA copy number was significantly higher in ADHD patients than in HCs (p = 0.028). The mtDNA methylation ratio of PPARGC1A was decreased in ADHD patients compared with HCs (p = 0.008). After adjusting for IQ level, only the mtDNA copy number differed between the ADHD and HCs (p = 0.01). There was a significant difference in the methylation ratio of PPARGC1A among ADHD subtypes. These results suggest the possible involvement of mitochondrial dysfunction in the pathophysiology of ADHD. Further large cohort studies investigating the correlation between clinical markers and biomarkers of mitochondrial dysfunction are warranted.
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Affiliation(s)
- Johanna Inhyang Kim
- Department of Psychiatry, Hanyang University Medical Center, Seoul, South Korea
| | - Soo-Young Lee
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, South Korea
| | - Mira Park
- Department of Preventive Medicine, School of Medicine, Eulji University, Daejeon, South Korea
| | - Si Yeon Kim
- Department of Preventive Medicine, School of Medicine, Eulji University, Daejeon, South Korea
| | - Jae-Won Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea
| | - Soon Ae Kim
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, South Korea
| | - Bung-Nyun Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea
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20
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Tsujii N, Otsuka I, Okazaki S, Yanagi M, Numata S, Yamaki N, Kawakubo Y, Shirakawa O, Hishimoto A. Mitochondrial DNA Copy Number Raises the Potential of Left Frontopolar Hemodynamic Response as a Diagnostic Marker for Distinguishing Bipolar Disorder From Major Depressive Disorder. Front Psychiatry 2019; 10:312. [PMID: 31139101 PMCID: PMC6518968 DOI: 10.3389/fpsyt.2019.00312] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 04/23/2019] [Indexed: 01/10/2023] Open
Abstract
Background: Given a lack of markers, diagnoses of bipolar disorder (BD) and major depressive disorder (MDD) rely on clinical assessment of symptoms. However, the depressive mood states of BD and depressive symptoms of MDD are often difficult to distinguish, which leads to misdiagnoses, which in turn leads to inadequate treatment. Previous studies have shown that the hemodynamic responses of the left frontopolar cortex measured by near-infrared spectroscopy (NIRS) differ between BD and MDD; these hemodynamic responses are associated with altered mitochondrial metabolism; and mitochondrial DNA copy number (mtDNAcn), an index of mitochondrial dysfunction, tends to decrease in BD and increase in MDD patients. In this study, we confirmed that mtDNAcn trends in opposite directions in BD and MDD. We then determined whether mtDNAcn could enhance the utility of NIRS as a diagnostic marker to distinguish between BD and MDD. Methods: We determined mtDNAcn in peripheral blood samples from 58 healthy controls, 79 patients with BD, and 44 patients with MDD. Regional hemodynamic responses during a verbal fluency task (VFT) in 24 BD patients and 44 MDD patients, matched by age and depression severity, were monitored using NIRS. Results: Measurements of mtDNAcn were lower in BD patients and higher in MDD patients than in controls. The left frontopolar region exhibited the most significant differences in mean VFT-related oxy-Hb changes between the BD and MDD groups. Multivariate logistic regression analysis with variables including age, sex, hemodynamic response of the left frontopolar region, and mtDNAcn showed high accuracy for distinguishing BD from MDD (area under the curve = 0.917; 95% confidence interval = 0.849-0.985). For the BD group, we observed a positive correlation between hemodynamic responses in the left frontopolar region and mtDNAcn, while for the MDD group, we observed a negative correlation. Conclusions: Our findings suggest that the association between hemodynamic response and mitochondrial dysfunction in BD or MDD plays an important role in differentiating the pathophysiological mechanisms of BD from those of MDD.
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Affiliation(s)
- Noa Tsujii
- Department of Neuropsychiatry, Kindai University Faculty of Medicine, Osaka-sayama, Japan
| | - Ikuo Otsuka
- Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Satoshi Okazaki
- Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masaya Yanagi
- Department of Neuropsychiatry, Kindai University Faculty of Medicine, Osaka-sayama, Japan
| | - Shusuke Numata
- Department of Psychiatry, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, Japan
| | - Naruhisa Yamaki
- Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yoshihiro Kawakubo
- Department of Neuropsychiatry, Kindai University Faculty of Medicine, Osaka-sayama, Japan
| | - Osamu Shirakawa
- Department of Neuropsychiatry, Kindai University Faculty of Medicine, Osaka-sayama, Japan
| | - Akitoyo Hishimoto
- Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan
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21
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Ramos A, Planchat M, Vieira Melo AR, Raposo M, Shamim U, Suroliya V, Srivastava AK, Faruq M, Morino H, Ohsawa R, Kawakami H, Bannach Jardim L, Saraiva-Pereira ML, Vasconcelos J, Santos C, Lima M. Mitochondrial DNA haplogroups and age at onset of Machado-Joseph disease/spinocerebellar ataxia type 3: a study in patients from multiple populations. Eur J Neurol 2018; 26:506-512. [PMID: 30414314 DOI: 10.1111/ene.13860] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/06/2018] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND PURPOSE Mitochondrial dysfunction has been implicated in the pathogenesis of several neurodegenerative disorders, including Machado-Joseph disease (MJD), an autosomal dominant late-onset polyglutamine ataxia that results from an unstable expansion of a CAG tract in the ATXN3 gene. The size of the CAG tract only partially explains age at onset (AO), highlighting the existence of disease modifiers. Mitochondrial DNA (mtDNA) haplogroups have been associated with clinical presentation in other polyglutamine disorders, constituting potential modifiers of MJD phenotype. METHODS A cross-sectional study, using 235 unrelated patients from Portugal, Brazil, India and Japan, was performed to investigate if mtDNA haplogroups contribute to AO of MJD. mtDNA haplogroups were obtained after sequencing the mtDNA hypervariable region I. Patients were classified in 15 phylogenetically related haplogroup clusters. RESULTS The AO was significantly different among populations, implying the existence of other non-CAG factors, which seem to be population specific. In the Portuguese population, patients classified as belonging to haplogroup JT presented the earliest onset (estimated onset 34.6 years of age). Haplogroups W and X seem to have a protective effect, causing a delay in onset (estimated onset 47 years of age). No significant association between haplogroup clusters and AO was detected in the other populations or when all patients were pooled. Although haplogroup JT has already been implicated in other neurodegenerative disorders, no previous reports of an association between haplogroups W and X and disease were found. CONCLUSIONS These findings suggest that haplogroups JT, W and X modify AO in MJD. Replication studies should be performed in European populations, where the frequency of the candidate modifiers is similar.
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Affiliation(s)
- A Ramos
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Departamento Biologia Animal, Biologia Vegetal i Ecologia, Unitat d'Antropologia Biològica, Universitat Autònoma de Barcelona, Cerdanyola del Valles, Spain
| | - M Planchat
- Departamento Biologia Animal, Biologia Vegetal i Ecologia, Unitat d'Antropologia Biològica, Universitat Autònoma de Barcelona, Cerdanyola del Valles, Spain
| | - A R Vieira Melo
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - M Raposo
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - U Shamim
- CSIR - Institute of Genomics and Integrative Biology (IGIB), New Delhi, India
| | - V Suroliya
- CSIR - Institute of Genomics and Integrative Biology (IGIB), New Delhi, India.,Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences, New Delhi, India
| | - A K Srivastava
- Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences, New Delhi, India
| | - M Faruq
- CSIR - Institute of Genomics and Integrative Biology (IGIB), New Delhi, India
| | - H Morino
- Department of Epidemiology, Research Institute for Radiology and Medicine, Hiroshima University, Hiroshima, Japan
| | - R Ohsawa
- Department of Epidemiology, Research Institute for Radiology and Medicine, Hiroshima University, Hiroshima, Japan
| | - H Kawakami
- Department of Epidemiology, Research Institute for Radiology and Medicine, Hiroshima University, Hiroshima, Japan
| | - L Bannach Jardim
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - M L Saraiva-Pereira
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - J Vasconcelos
- Serviço de Neurologia, Hospital do Divino Espírito Santo, Ponta Delgada, Açores, Portugal
| | - C Santos
- Departamento Biologia Animal, Biologia Vegetal i Ecologia, Unitat d'Antropologia Biològica, Universitat Autònoma de Barcelona, Cerdanyola del Valles, Spain
| | - M Lima
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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22
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Harmuth T, Prell-Schicker C, Weber JJ, Gellerich F, Funke C, Drießen S, Magg JCD, Krebiehl G, Wolburg H, Hayer SN, Hauser S, Krüger R, Schöls L, Riess O, Hübener-Schmid J. Mitochondrial Morphology, Function and Homeostasis Are Impaired by Expression of an N-terminal Calpain Cleavage Fragment of Ataxin-3. Front Mol Neurosci 2018; 11:368. [PMID: 30364204 PMCID: PMC6192284 DOI: 10.3389/fnmol.2018.00368] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/18/2018] [Indexed: 12/14/2022] Open
Abstract
Alterations in mitochondrial morphology and function have been linked to neurodegenerative diseases, including Parkinson disease, Alzheimer disease and Huntington disease. Metabolic defects, resulting from dysfunctional mitochondria, have been reported in patients and respective animal models of all those diseases. Spinocerebellar Ataxia Type 3 (SCA3), another neurodegenerative disorder, also presents with metabolic defects and loss of body weight in early disease stages although the possible role of mitochondrial dysfunction in SCA3 pathology is still to be determined. Interestingly, the SCA3 disease protein ataxin-3, which is predominantly localized in cytoplasm and nucleus, has also been associated with mitochondria in both its mutant and wildtype form. This observation provides an interesting link to a potential mitochondrial involvement of mutant ataxin-3 in SCA3 pathogenesis. Furthermore, proteolytic cleavage of ataxin-3 has been shown to produce toxic fragments and even overexpression of artificially truncated forms of ataxin-3 resulted in mitochondria deficits. Therefore, we analyzed the repercussions of expressing a naturally occurring N-terminal cleavage fragment of ataxin-3 and the influence of an endogenous expression of the S256 cleavage fragment in vitro and in vivo. In our study, expression of a fragment derived from calpain cleavage induced mitochondrial fragmentation and cristae alterations leading to a significantly decreased capacity of mitochondrial respiration and contributing to an increased susceptibility to apoptosis. Furthermore, analyzing mitophagy revealed activation of autophagy in the early pathogenesis with reduced lysosomal activity. In conclusion, our findings indicate that cleavage of ataxin-3 by calpains results in fragments which interfere with mitochondrial function and mitochondrial degradation processes.
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Affiliation(s)
- Tina Harmuth
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany.,Graduate School of Cellular Neuroscience, University of Tübingen, Tübingen, Germany
| | - Caroline Prell-Schicker
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Jonasz J Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
| | - Frank Gellerich
- Department of Neurology, University Hospital Magdeburg, Magdeburg, Germany
| | - Claudia Funke
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Stefan Drießen
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Janine C D Magg
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
| | - Guido Krebiehl
- Center of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology, University of Tübingen, Tübingen, Germany
| | - Stefanie N Hayer
- German Center for Neurodegenerative Diseases, Tübingen, Germany.,Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Stefan Hauser
- German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Rejko Krüger
- Center of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Ludger Schöls
- German Center for Neurodegenerative Diseases, Tübingen, Germany.,Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
| | - Jeannette Hübener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
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23
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Matos CA, de Almeida LP, Nóbrega C. Machado-Joseph disease/spinocerebellar ataxia type 3: lessons from disease pathogenesis and clues into therapy. J Neurochem 2018; 148:8-28. [PMID: 29959858 DOI: 10.1111/jnc.14541] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/05/2018] [Accepted: 06/27/2018] [Indexed: 12/25/2022]
Abstract
Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), is an incurable disorder, widely regarded as the most common form of spinocerebellar ataxia in the world. MJD/SCA3 arises from mutation of the ATXN3 gene, but this simple monogenic cause contrasts with the complexity of the pathogenic mechanisms that are currently admitted to underlie neuronal dysfunction and death. The aberrantly expanded protein product - ataxin-3 - is known to aggregate and generate toxic species that disrupt several cell systems, including autophagy, proteostasis, transcription, mitochondrial function and signalling. Over the years, research into putative therapeutic approaches has often been devoted to the development of strategies that counteract disease at different stages of cellular pathogenesis. Silencing the pathogenic protein, blocking aggregation, inhibiting toxic proteolytic processing and counteracting dysfunctions of the cellular systems affected have yielded promising ameliorating results in studies with cellular and animal models. The current review analyses the available studies dedicated to the investigation of MJD/SCA3 pathogenesis and the exploration of possible therapeutic strategies, focusing primarily on gene therapy and pharmacological approaches rooted on the molecular and cellular mechanisms of disease.
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Affiliation(s)
- Carlos A Matos
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Clévio Nóbrega
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Department of Biomedical Sciences and Medicine, University of Algarve, Coimbra, Portugal.,Centre for Biomedical Research (CBMR), University of Algarve, Coimbra, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Faro, Portugal
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24
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Lieberman AP, Shakkottai VG, Albin RL. Polyglutamine Repeats in Neurodegenerative Diseases. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2018; 14:1-27. [PMID: 30089230 DOI: 10.1146/annurev-pathmechdis-012418-012857] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Among the age-dependent protein aggregation disorders, nine neurodegenerative diseases are caused by expansions of CAG repeats encoding polyglutamine (polyQ) tracts. We review the clinical, pathological, and biological features of these inherited disorders. We discuss insights into pathogenesis gleaned from studies of model systems and patients, highlighting work that informs efforts to develop effective therapies. An important conclusion from these analyses is that expanded CAG/polyQ domains are the primary drivers of neurodegeneration, with the biology of carrier proteins influencing disease-specific manifestations. Additionally, it has become apparent that CAG/polyQ repeat expansions produce neurodegeneration via multiple downstream mechanisms, involving both gain- and loss-of-function effects. This conclusion indicates that the likelihood of developing effective therapies targeting single nodes is reduced. The evaluation of treatments for premanifest disease will likely require new investigational approaches. We highlight the opportunities and challenges underlying ongoing work and provide recommendations related to the development of symptomatic and disease-modifying therapies and biomarkers that could inform future research.
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Affiliation(s)
- Andrew P Lieberman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA;
| | - Vikram G Shakkottai
- Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA; , .,Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Roger L Albin
- Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA; , .,Neurology Service and the Geriatric Research, Education, and Clinical Center (GRECC), VA Ann Arbor Healthcare System, Ann Arbor, Michigan 48105, USA
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25
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Toonen LJA, Overzier M, Evers MM, Leon LG, van der Zeeuw SAJ, Mei H, Kielbasa SM, Goeman JJ, Hettne KM, Magnusson OT, Poirel M, Seyer A, 't Hoen PAC, van Roon-Mom WMC. Transcriptional profiling and biomarker identification reveal tissue specific effects of expanded ataxin-3 in a spinocerebellar ataxia type 3 mouse model. Mol Neurodegener 2018; 13:31. [PMID: 29929540 PMCID: PMC6013885 DOI: 10.1186/s13024-018-0261-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 05/23/2018] [Indexed: 12/12/2022] Open
Abstract
Background Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by expansion of the polyglutamine repeat in the ataxin-3 protein. Expression of mutant ataxin-3 is known to result in transcriptional dysregulation, which can contribute to the cellular toxicity and neurodegeneration. Since the exact causative mechanisms underlying this process have not been fully elucidated, gene expression analyses in brains of transgenic SCA3 mouse models may provide useful insights. Methods Here we characterised the MJD84.2 SCA3 mouse model expressing the mutant human ataxin-3 gene using a multi-omics approach on brain and blood. Gene expression changes in brainstem, cerebellum, striatum and cortex were used to study pathological changes in brain, while blood gene expression and metabolites/lipids levels were examined as potential biomarkers for disease. Results Despite normal motor performance at 17.5 months of age, transcriptional changes in brain tissue of the SCA3 mice were observed. Most transcriptional changes occurred in brainstem and striatum, whilst cerebellum and cortex were only modestly affected. The most significantly altered genes in SCA3 mouse brain were Tmc3, Zfp488, Car2, and Chdh. Based on the transcriptional changes, α-adrenergic and CREB pathways were most consistently altered for combined analysis of the four brain regions. When examining individual brain regions, axon guidance and synaptic transmission pathways were most strongly altered in striatum, whilst brainstem presented with strongest alterations in the pi-3 k cascade and cholesterol biosynthesis pathways. Similar to other neurodegenerative diseases, reduced levels of tryptophan and increased levels of ceramides, di- and triglycerides were observed in SCA3 mouse blood. Conclusions The observed transcriptional changes in SCA3 mouse brain reveal parallels with previous reported neuropathology in patients, but also shows brain region specific effects as well as involvement of adrenergic signalling and CREB pathway changes in SCA3. Importantly, the transcriptional changes occur prior to onset of motor- and coordination deficits. Electronic supplementary material The online version of this article (10.1186/s13024-018-0261-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lodewijk J A Toonen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Maurice Overzier
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Melvin M Evers
- Department of Research & Development, uniQure, Amsterdam, The Netherlands
| | - Leticia G Leon
- Cancer Pharmacology Lab, University of Pisa, Ospedale di Cisanello, Edificio 6 via Paradisa, 2, 56124, Pisa, Italy
| | - Sander A J van der Zeeuw
- Sequencing Analysis Support Core, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Szymon M Kielbasa
- Department of Biomedical Data Sciences, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Jelle J Goeman
- Department of Biomedical Data Sciences, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Kristina M Hettne
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | | | | | | | - Peter A C 't Hoen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands.,Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Willeke M C van Roon-Mom
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands.
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26
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Accumulation of Mitochondrial DNA Common Deletion Since The Preataxic Stage of Machado-Joseph Disease. Mol Neurobiol 2018; 56:119-124. [PMID: 29679261 DOI: 10.1007/s12035-018-1069-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/09/2018] [Indexed: 12/27/2022]
Abstract
Molecular alterations reflecting pathophysiologic changes thought to occur many years before the clinical onset of Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3), a late-onset polyglutamine disorder, remain unidentified. The absence of molecular biomarkers hampers clinical trials, which lack sensitive measures of disease progression, preventing the identification of events occurring prior to clinical onset. Our aim was to analyse the mtDNA content and the amount of the common deletion (m.8482_13460del4977) in a cohort of 16 preataxic MJD mutation carriers, 85 MJD patients and 101 apparently healthy age-matched controls. Relative expression levels of RPPH1, MT-ND1 and MT-ND4 genes were assessed by quantitative real-time PCR. The mtDNA content was calculated as the difference between the expression levels of a mitochondrial gene (MT-ND1) and a nuclear gene (RPPH1); the amount of mtDNA common deletion was calculated as the difference between expression levels of a deleted (MT-ND4) and an undeleted (MT-ND1) mitochondrial genes. mtDNA content in MJD carriers was similar to that of healthy age-matched controls, whereas the percentage of the common deletion was significantly increased in MJD subjects, and more pronounced in the preclinical stage (p < 0.05). The BCL2/BAX ratio was decreased in preataxic carriers compared to controls, suggesting that the mitochondrial-mediated apoptotic pathway is altered in MJD. Our findings demonstrate for the first time that accumulation of common deletion starts in the preclinical stage. Such early alterations provide support to the current understanding that any therapeutic intervention in MJD should start before the overt clinical phenotype.
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27
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Duarte-Silva S, Neves-Carvalho A, Soares-Cunha C, Silva JM, Teixeira-Castro A, Vieira R, Silva-Fernandes A, Maciel P. Neuroprotective Effects of Creatine in the CMVMJD135 Mouse Model of Spinocerebellar Ataxia Type 3. Mov Disord 2018; 33:815-826. [PMID: 29570846 DOI: 10.1002/mds.27292] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/27/2017] [Accepted: 12/18/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND AND OBJECTIVE Mitochondrial dysfunction has been implicated in several neurodegenerative diseases. Creatine administration increases concentration of the energy buffer phosphocreatine, exerting protective effects in the brain. We evaluate whether a creatine-enriched diet would be beneficial for a mouse model of spinocerebellar ataxia type 3, a genetically defined neurodegenerative disease for which no treatment is available. METHODS We performed 2 independent preclinical trials using the CMVMJD135 mouse model (treating 2 groups of animals with different disease severity) and wild-type mice, to which 2% creatine was provided for 19 (preclinical trial 1) or 29 (preclinical trial 2) weeks, starting at a presymptomatic age. Motor behavior was evaluated at several time points from 5 to 34 weeks of age, and neuropathological studies were performed at the end of each trial. RESULTS Creatine supplementation led to an overall improvement in the motor phenotype of CMVMJD135 mice in both trials, rescuing motor balance and coordination and also restored brain weight, mitigated astrogliosis, and preserved Calbindin-positive cells in the cerebellum. Moreover, a reduction of mutant ataxin-3 aggregates occurred despite maintained steady-state levels of the protein and the absence of autophagy activation. Creatine treatment also restored the expression of the mitochondrial mass marker Porin and reduced the expression of antioxidant enzymes Heme oxygenase 1 (HO1) and NAD(P)H Quinone Dehydrogenase 1 (NQO1), suggesting a beneficial effect at the level of mitochondria and oxidative stress. CONCLUSIONS Creatine slows disease progression and improves motor dysfunction as well as ameliorates neuropathology of the CMVMJD135 animals, supporting this as a useful strategy to slow the progression of spinocerebellar ataxia type 3. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Sara Duarte-Silva
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Andreia Neves-Carvalho
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Carina Soares-Cunha
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Joana M Silva
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Andreia Teixeira-Castro
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rita Vieira
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Anabela Silva-Fernandes
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
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28
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Lima M, Raposo M. Towards the Identification of Molecular Biomarkers of Spinocerebellar Ataxia Type 3 (SCA3)/Machado-Joseph Disease (MJD). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:309-319. [PMID: 29427111 DOI: 10.1007/978-3-319-71779-1_16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Whereas spinocerebellar ataxia type 3 (SCA3)/Machado-Joseph disease (MJD) remains an untreatable disorder, disease-modifying compounds have begun being tested in the context of clinical trials; their success is dependent on the sensitivity of the methods used to measure subtle therapeutic benefits. Thus, efforts are being made to propose a battery of potential outcome measures, including molecular biomarkers (MBs), which remain to be identified; MBs are particularly pertinent if SCA3 trials are expected to enroll preataxic subjects. Recently, promising candidate MBs of SCA3 have emerged from gene expression studies. In this chapter we provide a synthesis of the cross-sectional and pilot longitudinal studies of blood-based transcriptional biomarkers conducted so far. Other alterations with potential to track the progression of SCA3, such as those involving mitochondrial DNA (mtDNA) are also referred. It is expected that a set of molecular biomarkers can be identified; these will be used in complementarity with clinical and imaging markers to fully track SCA3, from its preataxic phase to the disease stage.
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Affiliation(s)
- Manuela Lima
- Departamento de Biologia, Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal. .,Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal. .,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.
| | - Mafalda Raposo
- Departamento de Biologia, Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal.,Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
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29
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Kristensen LV, Oppermann FS, Rauen MJ, Fog K, Schmidt T, Schmidt J, Harmuth T, Hartmann-Petersen R, Thirstrup K. Mass spectrometry analyses of normal and polyglutamine expanded ataxin-3 reveal novel interaction partners involved in mitochondrial function. Neurochem Int 2018; 112:5-17. [DOI: 10.1016/j.neuint.2017.10.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 09/01/2017] [Accepted: 10/09/2017] [Indexed: 12/13/2022]
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30
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Molecular Mechanisms and Cellular Pathways Implicated in Machado-Joseph Disease Pathogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:349-367. [PMID: 29427113 DOI: 10.1007/978-3-319-71779-1_18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Machado-Joseph disease (MJD) is a dominantly inherited disorder originally described in people of Portuguese descent, and associated with the expansion of a CAG tract in the coding region of the causative gene MJD1/ATX3. The CAG repeats range from 10 to 51 in the normal population and from 55 to 87 in SCA3/MJD patients. MJD1 encodes ataxin-3, a protein whose physiological function has been linked to ubiquitin-mediated proteolysis. Despite the identification of the causative mutation, the pathogenic process leading to the neurodegeneration observed in the disease is not yet completely understood. In the past years, several studies identified different molecular mechanisms and cellular pathways as being impaired or deregulated in MJD. Autophagy, proteolysis or post-translational modifications, among other processes, were implicated in MJD pathogenesis. From these studies it was possible to identify new targets for therapeutic intervention, which in some cases proved successful in models of disease.
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31
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Hsu JY, Jhang YL, Cheng PH, Chang YF, Mao SH, Yang HI, Lin CW, Chen CM, Yang SH. The Truncated C-terminal Fragment of Mutant ATXN3 Disrupts Mitochondria Dynamics in Spinocerebellar Ataxia Type 3 Models. Front Mol Neurosci 2017; 10:196. [PMID: 28676741 PMCID: PMC5476786 DOI: 10.3389/fnmol.2017.00196] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/02/2017] [Indexed: 01/24/2023] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3), known as Machado-Joseph disease, is an autosomal dominant disease caused by an abnormal expansion of polyglutamine in ATXN3 gene, leading to neurodegeneration in SCA3 patients. Similar to other neurodegenerative diseases, the dysfunction of mitochondria is observed to cause neuronal death in SCA3 patients. Based on previous studies, proteolytic cleavage of mutant ATXN3 is found to produce truncated C-terminal fragments in SCA3 models. However, whether these truncated mutant fragments disturb mitochondrial functions and result in pathological death is still unclear. Here, we used neuroblastoma cell and transgenic mouse models to examine the effects of truncated mutant ATXN3 on mitochondria functions. In different models, we observed truncated mutant ATXN3 accelerated the formation of aggregates, which translocated into the nucleus to form intranuclear aggregates. In addition, truncated mutant ATXN3 caused more mitochondrial fission, and decreased the expression of mitochondrial fusion markers, including Mfn-1 and Mfn-2. Furthermore, truncated mutant ATXN3 decreased the mitochondrial membrane potential, increased reactive oxygen species and finally increased cell death rate. In transgenic mouse models, truncated mutant ATXN3 also led to more mitochondrial dysfunction, neurodegeneration and cell death in the cerebellums. This study supports the toxic fragment hypothesis in SCA3, and also provides evidence that truncated mutant ATXN3 is severer than full-length mutant one in vitro and in vivo.
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Affiliation(s)
- Jung-Yu Hsu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan.,Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Yu-Ling Jhang
- Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Pei-Hsun Cheng
- Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Yu-Fan Chang
- Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Su-Han Mao
- Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Han-In Yang
- Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Chia-Wei Lin
- Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Chuan-Mu Chen
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing UniversityTaichung, Taiwan
| | - Shang-Hsun Yang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan.,Department of Physiology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
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32
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Abstract
Mitochondrial DNA (mtDNA) lacks the protection provided by the nucleosomes in the nuclear DNA and does not have a DNA repair mechanism, making it highly susceptible to damage, which can lead to mtDNA depletion. mtDNA depletion compromises the efficient function of cells and tissues and thus impacts negatively on health. Here, we describe a brief and easy protocol to quantify mtDNA copy number by determining the mtDNA/nDNA ratio. The procedure has been validated using a cohort of young and aged mice. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Pedro M Quiros
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Aashima Goyal
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Pooja Jha
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
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Perez SD, Du K, Rendeiro C, Wang L, Wu Q, Rubakhin SS, Vazhappilly R, Baxter JH, Sweedler JV, Rhodes JS. A unique combination of micronutrients rejuvenates cognitive performance in aged mice. Behav Brain Res 2017; 320:97-112. [DOI: 10.1016/j.bbr.2016.11.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 10/30/2016] [Accepted: 11/03/2016] [Indexed: 12/16/2022]
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Yoo HJ, Park M, Kim SA. Difference in mitochondrial DNA copy number in peripheral blood cells between probands with autism spectrum disorders and their unaffected siblings. World J Biol Psychiatry 2017; 18:151-156. [PMID: 27739340 DOI: 10.1080/15622975.2016.1234069] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Several reports suggest that mitochondrial dysfunction is involved in the pathophysiology of autism spectrum disorders (ASD). Therefore, mitochondrial DNA (mtDNA) copy number, a common biomarker for mitochondrial dysfunction, might be associated with ASD phenotypes. METHODS Relative mtDNA copy number in the peripheral blood cells of 100 Korean ASD patients and their unaffected sib-pairs was measured by quantitative polymerase chain reaction (qPCR). RESULTS ASD patients had significantly higher relative mtDNA copy numbers than their unaffected sibs (P = .042). In addition, there were statistically significant correlations between mtDNA copy number and clinical phenotypes for language and communication in ASD. CONCLUSIONS Our findings suggest that mitochondrial dysfunction and elevated mtDNA copy number may be a biological subtype of ASD that is related to the phenotype for communication.
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Affiliation(s)
- Hee Jeong Yoo
- a Department of Neuropsychiatry , Seoul National University Bungdang Hospital , Seongnam , Korea
| | - Mira Park
- b Department of Preventive Medicine , School of Medicine, Eulji University , Daejeon , Korea
| | - Soon Ae Kim
- c Department of Pharmacology , School of Medicine, Eulji University , Daejeon , Korea
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Snijder PM, Baratashvili M, Grzeschik NA, Leuvenink HGD, Kuijpers L, Huitema S, Schaap O, Giepmans BNG, Kuipers J, Miljkovic JL, Mitrovic A, Bos EM, Szabó C, Kampinga HH, Dijkers PF, Bos EM, Szabó C, Kampinga HH, Dijkers PF, Dunnen WFAD, Filipovic MR, Goor HV, Sibon OCM. Overexpression of Cystathionine γ-Lyase Suppresses Detrimental Effects of Spinocerebellar Ataxia Type 3. Mol Med 2015; 21:758-768. [PMID: 26467707 DOI: 10.2119/molmed.2015.00221] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 10/09/2015] [Indexed: 01/20/2023] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a polyglutamine (polyQ) disorder caused by a CAG repeat expansion in the ataxin-3 (ATXN3) gene resulting in toxic protein aggregation. Inflammation and oxidative stress are considered secondary factors contributing to the progression of this neurodegenerative disease. There is no cure that halts or reverses the progressive neurodegeneration of SCA3. Here we show that overexpression of cystathionine γ-lyase, a central enzyme in cysteine metabolism, is protective in a Drosophila model for SCA3. SCA3 flies show eye degeneration, increased oxidative stress, insoluble protein aggregates, reduced levels of protein persulfidation and increased activation of the innate immune response. Overexpression of Drosophila cystathionine γ-lyase restores protein persulfidation, decreases oxidative stress, dampens the immune response and improves SCA3-associated tissue degeneration. Levels of insoluble protein aggregates are not altered; therefore, the data implicate a modifying role of cystathionine γ-lyase in ameliorating the downstream consequence of protein aggregation leading to protection against SCA3-induced tissue degeneration. The cystathionine γ-lyase expression is decreased in affected brain tissue of SCA3 patients, suggesting that enhancers of cystathionine γ-lyase expression or activity are attractive candidates for future therapies.
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Affiliation(s)
- Pauline M Snijder
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Madina Baratashvili
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Nicola A Grzeschik
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Henri G D Leuvenink
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Lucas Kuijpers
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Sippie Huitema
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Onno Schaap
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ben N G Giepmans
- UMCG Microscopy and Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jeroen Kuipers
- UMCG Microscopy and Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jan Lj Miljkovic
- Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - Eelke M Bos
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Csaba Szabó
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Harm H Kampinga
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Pascale F Dijkers
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Eelke M Bos
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Csaba Szabó
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Harm H Kampinga
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Pascale F Dijkers
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Wilfred F A den Dunnen
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Milos R Filipovic
- Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
| | - Harry van Goor
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ody C M Sibon
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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The exonuclease activity of DNA polymerase γ is required for ligation during mitochondrial DNA replication. Nat Commun 2015; 6:7303. [PMID: 26095671 PMCID: PMC4557304 DOI: 10.1038/ncomms8303] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 04/27/2015] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial DNA (mtDNA) polymerase γ (POLγ) harbours a 3′–5′ exonuclease proofreading activity. Here we demonstrate that this activity is required for the creation of ligatable ends during mtDNA replication. Exonuclease-deficient POLγ fails to pause on reaching a downstream 5′-end. Instead, the enzyme continues to polymerize into double-stranded DNA, creating an unligatable 5′-flap. Disease-associated mutations can both increase and decrease exonuclease activity and consequently impair DNA ligation. In mice, inactivation of the exonuclease activity causes an increase in mtDNA mutations and premature ageing phenotypes. These mutator mice also contain high levels of truncated, linear fragments of mtDNA. We demonstrate that the formation of these fragments is due to impaired ligation, causing nicks near the origin of heavy-strand DNA replication. In the subsequent round of replication, the nicks lead to double-strand breaks and linear fragment formation. Mitochondrial DNA (mtDNA) polymerase γ has a 3′–5′ exonuclease proofreading activity. Here, the authors show it is required for creating ligatable ends during mtDNA replication, and inactivation of the activity in mice causes strand-specific nicks in DNA and the formation of linear mtDNA fragments.
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Tyrka AR, Carpenter LL, Kao HT, Porton B, Philip NS, Ridout SJ, Ridout KK, Price LH. Association of telomere length and mitochondrial DNA copy number in a community sample of healthy adults. Exp Gerontol 2015; 66:17-20. [PMID: 25845980 DOI: 10.1016/j.exger.2015.04.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 10/23/2022]
Abstract
Cellular aging plays a role in longevity and senescence, and has been implicated in medical and psychiatric conditions, including heart disease, cancer, major depression and posttraumatic stress disorder. Telomere shortening and mitochondrial dysfunction are thought to be central to the cellular aging process. The present study examined the association between mitochondrial DNA (mtDNA) copy number and telomere length in a sample of medically healthy adults. Participants (total n=392) were divided into 4 groups based on the presence or absence of early life adversity and lifetime psychopathology: No Adversity/No Disorder, n=136; Adversity/No Disorder, n=91; No Adversity/Disorder, n=46; Adversity/Disorder, n=119. Telomere length and mtDNA copy number were measured using quantitative polymerase chain reaction. There was a positive correlation between mtDNA and telomere length in the entire sample (r=0.120, p<0.001) and in each of the four groups of participants (No Adversity/No Disorder, r=0.291, p=0.001; Adversity/No Disorder r=0.279, p=0.007; No Adversity/Disorder r=0.449, p=0.002; Adversity/Disorder, r=0.558, p<0.001). These correlations remained significant when controlling for age, smoking, and body mass index and establish an association between mtDNA and telomere length in a large group of women and men both with and without early adversity and psychopathology, suggesting co-regulation of telomeres and mitochondrial function. The mechanisms underlying this association may be important in the pathophysiology of age-related medical conditions, such as heart disease and cancer, as well as for stress-associated psychiatric disorders.
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Affiliation(s)
- Audrey R Tyrka
- Mood Disorders Research Program and Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Providence, RI, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA.
| | - Linda L Carpenter
- Mood Disorders Research Program and Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Providence, RI, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA
| | - Hung-Teh Kao
- Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA; Laboratory of Molecular Psychiatry, Butler Hospital, Providence, RI, USA
| | - Barbara Porton
- Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA; Laboratory of Molecular Psychiatry, Butler Hospital, Providence, RI, USA
| | - Noah S Philip
- Mood Disorders Research Program and Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Providence, RI, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA
| | - Samuel J Ridout
- Mood Disorders Research Program and Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Providence, RI, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA
| | - Kathryn K Ridout
- Mood Disorders Research Program and Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Providence, RI, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA
| | - Lawrence H Price
- Mood Disorders Research Program and Laboratory for Clinical and Translational Neuroscience, Butler Hospital, Providence, RI, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, USA
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Chen S, Li Z, He Y, Zhang F, Li H, Liao Y, Wei Z, Wan G, Xiang X, Hu M, Xia K, Chen X, Tang J. Elevated mitochondrial DNA copy number in peripheral blood cells is associated with childhood autism. BMC Psychiatry 2015; 15:50. [PMID: 25884388 PMCID: PMC4367837 DOI: 10.1186/s12888-015-0432-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 02/27/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Several lines of evidence indicate mitochondrial impairment in the pathophysiology of autism. As one of the most common biomarkers for mitochondrial dysfunction, mitochondrial DNA (mtDNA) copy number has also been linked to autism, but the relationship between mtDNA copy number and autism was still obscured. In this study, we performed a case-control study to investigate whether mtDNA copy number in peripheral blood cells is related to patients with autism. METHODS Relative mtDNA copy number in peripheral blood cells was measured by using real-time polymerase chain reaction method. The participants in this study included 78 patients with childhood autism and 83 typically developing children. RESULTS We observed children with autism had significantly elevated relative mtDNA copy number than healthy controls (Beta = -0.173, P = 0.0003). However, there were no significant correlations between mtDNA copy number and clinical features (paternal age, maternal age, age of onset, illness of duration, CARS score and ABC score) in childhood autism. CONCLUSION We show that elevated mtDNA copy number in peripheral blood is associated with autism, indicating that there may be mitochondrial dysfunction in children with autism.
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Affiliation(s)
- Shan Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, China.
| | - Zongchang Li
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China.
| | - Ying He
- Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China.
| | - Fengyu Zhang
- Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China. .,The National Clinical Research Center for Psychiatric and Psychological Diseases, Changsha, China. .,Division of Clinical Sciences, Lieber Institute for Brain Development, John Hopkins University Medical Campus, 855 N. Wolfe Street, Suite 300, Baltimore, 21205, MD, USA.
| | - Hong Li
- Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China.
| | - Yanhui Liao
- Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China.
| | - Zhen Wei
- Department of Women's Health Care, The Affiliated Shenzhen Maternal and Child Health Care Hospital, Nanfang University of Medical Science, Shenzhen, China.
| | - Guobin Wan
- Department of Women's Health Care, The Affiliated Shenzhen Maternal and Child Health Care Hospital, Nanfang University of Medical Science, Shenzhen, China.
| | - Xi Xiang
- BGI Ark Biotechnology Co., Ltd., Shenzhen, Guangdong, China.
| | - Maolin Hu
- Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China.
| | - Kun Xia
- The State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China.
| | - Xiaogang Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, China. .,Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China. .,The National Clinical Research Center for Psychiatric and Psychological Diseases, Changsha, China.
| | - Jinsong Tang
- Institute of Mental Health of the Second Xiangya Hospital, National Laboratory for Psychiatric Disease Diagnosis and Treatment, Key Laboratory of Psychiatry and Mental Health of Hunan Province, The Central South University, Changsha, China. .,The National Clinical Research Center for Psychiatric and Psychological Diseases, Changsha, China. .,Division of Clinical Sciences, Lieber Institute for Brain Development, John Hopkins University Medical Campus, 855 N. Wolfe Street, Suite 300, Baltimore, 21205, MD, USA.
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Ramos A, Kazachkova N, Silva F, Maciel P, Silva-Fernandes A, Duarte-Silva S, Santos C, Lima M. Differential mtDNA damage patterns in a transgenic mouse model of Machado-Joseph disease (MJD/SCA3). J Mol Neurosci 2014; 55:449-53. [PMID: 25001003 DOI: 10.1007/s12031-014-0360-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/19/2014] [Indexed: 12/17/2022]
Abstract
Mitochondrial dysfunction has been associated with late onset neurodegenerative disorders, among which is Machado-Joseph disease (MJD/SCA3). In a previous study, using a transgenic mouse model of MJD, we reported a decrease in mitochondrial DNA (mtDNA) copy number and an accumulation of the 3876-bp deletion with age and with phenotype development. We extended this study by analyzing the pattern of mtDNA depletion and the accumulation of the 3876-bp deletion in 12 older transgenic (TG) and 4 wild-type (wt) animals, and by investigating the accumulation of somatic mutations in the D-loop region in 76 mice (42 TG and 34 wt). mtDNA damage was studied in TG and wt mice at different ages and tissues (blood, pontine nuclei, and hippocampus). Results for older mice demonstrate an accumulation of the mtDNA 3867-bp deletion with age, which was more pronounced in TG animals. Furthermore, the tendency for mtDNA copy number decrease with age, in all analyzed tissues of TG and wt animals, was also confirmed. No point mutations were detected in the D-loop, neither in TG nor wt animals, in any of the tissues analyzed. Due to the absence of mtDNA somatic mutations, we can suggest that mtDNA point mutation accumulation cannot be used to monitor the development and progression of the phenotype in this mouse model and likely in any MJD mice model. The present results further confirm not only the association between mtDNA alterations (copy number and deletions) and age, but also between such alterations and the expression of the mutant ataxin-3 in TG mice.
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Affiliation(s)
- Amanda Ramos
- Centre of Research in Natural Resources (CIRN), Department of Biology, University of the Azores, Ponta Delgada, Portugal,
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Evers MM, Toonen LJA, van Roon-Mom WMC. Ataxin-3 protein and RNA toxicity in spinocerebellar ataxia type 3: current insights and emerging therapeutic strategies. Mol Neurobiol 2014; 49:1513-31. [PMID: 24293103 PMCID: PMC4012159 DOI: 10.1007/s12035-013-8596-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 11/14/2013] [Indexed: 01/10/2023]
Abstract
Ataxin-3 is a ubiquitously expressed deubiqutinating enzyme with important functions in the proteasomal protein degradation pathway and regulation of transcription. The C-terminus of the ataxin-3 protein contains a polyglutamine (PolyQ) region that, when mutationally expanded to over 52 glutamines, causes the neurodegenerative disease spinocerebellar ataxia 3 (SCA3). In spite of extensive research, the molecular mechanisms underlying the cellular toxicity resulting from mutant ataxin-3 remain elusive and no preventive treatment is currently available. It has become clear over the last decade that the hallmark intracellular ataxin-3 aggregates are likely not the main toxic entity in SCA3. Instead, the soluble PolyQ containing fragments arising from proteolytic cleavage of ataxin-3 by caspases and calpains are now regarded to be of greater influence in pathogenesis. In addition, recent evidence suggests potential involvement of a RNA toxicity component in SCA3 and other PolyQ expansion disorders, increasing the pathogenic complexity. Herein, we review the functioning of ataxin-3 and the involvement of known protein and RNA toxicity mechanisms of mutant ataxin-3 that have been discovered, as well as future opportunities for therapeutic intervention.
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Affiliation(s)
- Melvin M. Evers
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, The Netherlands
| | - Lodewijk J. A. Toonen
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, The Netherlands
| | - Willeke M. C. van Roon-Mom
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, The Netherlands
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Kazachkova N, Ramos A, Santos C, Lima M. Mitochondrial DNA damage patterns and aging: revising the evidences for humans and mice. Aging Dis 2013; 4:337-50. [PMID: 24307967 DOI: 10.14336/ad.2013.0400337] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 01/07/2023] Open
Abstract
A significant body of work, accumulated over the years, strongly suggests that damage in mitochondrial DNA (mtDNA) contributes to aging in humans. Contradictory results, however, are reported in the literature, with some studies failing to provide support to this hypothesis. With the purpose of further understanding the aging process, several models, among which mouse models, have been frequently used. Although important affinities are recognized between humans and mice, differences on what concerns physiological properties, disease pathogenesis as well as life-history exist between the two; the extent to which such differences limit the translation, from mice to humans, of insights on the association between mtDNA damage and aging remains to be established. In this paper we revise the studies that analyze the association between patterns of mtDNA damage and aging, investigating putative alterations in mtDNA copy number as well as accumulation of deletions and of point mutations. Reports from the literature do not allow the establishment of a clear association between mtDNA copy number and age, either in humans or in mice. Further analysis, using a wide spectrum of tissues and a high number of individuals would be necessary to elucidate this pattern. Likewise humans, mice demonstrated a clear pattern of age-dependent and tissue-specific accumulation of mtDNA deletions. Deletions increase with age, and the highest amount of deletions has been observed in brain tissues both in humans and mice. On the other hand, mtDNA point mutations accumulation has been clearly associated with age in humans, but not in mice. Although further studies, using the same methodologies and targeting a larger number of samples would be mandatory to draw definitive conclusions, the revision of the available data raises concerns on the ability of mouse models to mimic the mtDNA damage patterns of humans, a fact with implications not only for the study of the aging process, but also for investigations of other processes in which mtDNA dysfunction is a hallmark, such as neurodegeneration.
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Affiliation(s)
- Nadiya Kazachkova
- Centre of Research in Natural Resources (CIRN), Department of Biology, University of the Azores, Ponta Delgada, Portugal ; Institute for Molecular and Cell Biology (IBMC), University of Porto, Porto, Portugal
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Durcan TM, Fon EA. Ataxin-3 and its e3 partners: implications for machado-joseph disease. Front Neurol 2013; 4:46. [PMID: 23653622 PMCID: PMC3644722 DOI: 10.3389/fneur.2013.00046] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 04/22/2013] [Indexed: 11/13/2022] Open
Abstract
Machado-Joseph disease (MJD) is the most common dominant inherited ataxia worldwide, caused by an unstable CAG trinucleotide expansion mutation within the SCA3 gene resulting in an expanded polyglutamine tract within the ataxin-3 protein. Ataxin-3 functions as a deubiquitinating enzyme (DUB), within the Ub system and whilst many DUBs are known to partner with and deubiquitinate specific E3-Ub ligases, ataxin-3 had no identified E3 partner until recent studies implicated parkin and CHIP, two neuroprotective E3 ligases. MJD often presents with symptoms of Parkinson disease (PD), which led to identification of parkin as a novel E3-Ub ligase whose activity was regulated by ataxin-3-mediated deubiquitination. Findings from these studies also revealed an unexpected convergence upon the E2-Ub-conjugating enzyme in the regulation of an E3/DUBenzyme pair. Moreover, mutant but not wild-type ataxin-3 promotes the clearance of parkin via the autophagy pathway, raising the intriguing possibility that increased turnover of parkin may contribute to the pathogenesis of MJD and help explain some of the Parkinsonian features in MJD. In addition to parkin, the U-box E3 ligase CHIP, a neuroprotective E3 implicated in protein quality control, was identified as a second E3 partner of ataxin-3, with ataxin-3 regulating the ability of CHIP to ubiquitinate itself. Indeed, ataxin-3 not only deubiquitinated CHIP, but also trimmed Ub conjugates on CHIP substrates, thereby regulating the length of Ub chains. Interestingly, when expanded ataxin-3 was present, CHIP levels were also reduced in the brains of MJD transgenic mice, raising the possibility that loss of one or both E3 partners may be a contributing factor in the pathogenesis of SCA3. In this review we discuss the implications from these studies and describe the importance of these findings in helping us understand the molecular processes involved in SCA3 and other neurodegenerative disorders.
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Affiliation(s)
- Thomas M Durcan
- Department of Neurology and Neurosurgery, Centre for Neuronal Survival and McGill Parkinson Program, Montreal Neurological Institute, McGill University Montreal, QC, Canada
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