1
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Jellinger KA. Mild cognitive impairment in Huntington's disease: challenges and outlooks. J Neural Transm (Vienna) 2024; 131:289-304. [PMID: 38265518 DOI: 10.1007/s00702-024-02744-8] [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: 11/30/2023] [Accepted: 01/14/2024] [Indexed: 01/25/2024]
Abstract
Although Huntington's disease (HD) has classically been viewed as an autosomal-dominant inherited neurodegenerative motor disorder, cognitive and/or behavioral changes are predominant and often an early manifestation of disease. About 40% of individuals in the presymptomatic period of HD meet the criteria for mild cognitive impairment, later progressing to dementia. The heterogenous spectrum of cognitive decline is characterized by deficits across multiple domains, particularly executive dysfunctions, but the underlying pathogenic mechanisms are still poorly understood. Investigating the pathophysiology of cognitive changes may give insight into important and early neurodegenerative events. Multimodal imaging revealed circuit-wide gray and white matter degenerative processes in several key brain regions, affecting prefronto-striatal/cortico-basal ganglia circuits and many other functional brain networks. Studies in transgenic animal models indicated early synaptic dysfunction, deficient neurotrophic transport and other molecular changes contributing to neuronal death. Synaptopathy within the cerebral cortex, striatum and hippocampus may be particularly important in mediating cognitive and neuropsychiatric manifestations of HD, although many other neuronal systems are involved. The interaction of mutant huntingtin protein (mHTT) with tau and its implication for cognitive impairment in HD is a matter of discussion. Further neuroimaging and neuropathological studies are warranted to better elucidate early pathophysiological mechanisms and to develop validated biomarkers to detect patients' cognitive status during the early stages of the condition significantly to implement effective preventing or management strategies.
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Affiliation(s)
- Kurt A Jellinger
- Institute of Clinical Neurobiology, Alberichgasse 5/13, 1150, Vienna, Austria.
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2
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Jiang A, Handley RR, Lehnert K, Snell RG. From Pathogenesis to Therapeutics: A Review of 150 Years of Huntington's Disease Research. Int J Mol Sci 2023; 24:13021. [PMID: 37629202 PMCID: PMC10455900 DOI: 10.3390/ijms241613021] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Huntington's disease (HD) is a debilitating neurodegenerative genetic disorder caused by an expanded polyglutamine-coding (CAG) trinucleotide repeat in the huntingtin (HTT) gene. HD behaves as a highly penetrant dominant disorder likely acting through a toxic gain of function by the mutant huntingtin protein. Widespread cellular degeneration of the medium spiny neurons of the caudate nucleus and putamen are responsible for the onset of symptomology that encompasses motor, cognitive, and behavioural abnormalities. Over the past 150 years of HD research since George Huntington published his description, a plethora of pathogenic mechanisms have been proposed with key themes including excitotoxicity, dopaminergic imbalance, mitochondrial dysfunction, metabolic defects, disruption of proteostasis, transcriptional dysregulation, and neuroinflammation. Despite the identification and characterisation of the causative gene and mutation and significant advances in our understanding of the cellular pathology in recent years, a disease-modifying intervention has not yet been clinically approved. This review includes an overview of Huntington's disease, from its genetic aetiology to clinical presentation and its pathogenic manifestation. An updated view of molecular mechanisms and the latest therapeutic developments will also be discussed.
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Affiliation(s)
- Andrew Jiang
- Applied Translational Genetics Group, Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand; (R.R.H.); (K.L.); (R.G.S.)
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3
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Plácido E, Gomes Welter P, Wink A, Karasiak GD, Outeiro TF, Dafre AL, Gil-Mohapel J, Brocardo PS. Beyond Motor Deficits: Environmental Enrichment Mitigates Huntington's Disease Effects in YAC128 Mice. Int J Mol Sci 2023; 24:12607. [PMID: 37628801 PMCID: PMC10454852 DOI: 10.3390/ijms241612607] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative genetic disorder characterized by motor, psychiatric, cognitive, and peripheral symptoms without effective therapy. Evidence suggests that lifestyle factors can modulate disease onset and progression, and environmental enrichment (EE) has emerged as a potential approach to mitigate the progression and severity of neurodegenerative processes. Wild-type (WT) and yeast artificial chromosome (YAC) 128 mice were exposed to different EE conditions. Animals from cohort 1 were exposed to EE between postnatal days 21 and 60, and animals from cohort 2 were exposed to EE between postnatal days 60 and 120. Motor and non-motor behavioral tests were employed to evaluate the effects of EE on HD progression. Monoamine levels, hippocampal cell proliferation, neuronal differentiation, and dendritic arborization were also assessed. Here we show that EE had an antidepressant-like effect and slowed the progression of motor deficits in HD mice. It also reduced monoamine levels, which correlated with better motor performance, particularly in the striatum. EE also modulated neuronal differentiation in the YAC128 hippocampus. These results confirm that EE can impact behavior, hippocampal neuroplasticity, and monoamine levels in YAC128 mice, suggesting this could be a therapeutic strategy to modulate neuroplasticity deficits in HD. However, further research is needed to fully understand EE's mechanisms and long-term effects as an adjuvant therapy for this debilitating condition.
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Affiliation(s)
- Evelini Plácido
- Neuroscience Graduate Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil (A.W.); (A.L.D.)
| | - Priscilla Gomes Welter
- Neuroscience Graduate Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil (A.W.); (A.L.D.)
| | - Ana Wink
- Neuroscience Graduate Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil (A.W.); (A.L.D.)
| | - Gabriela Duarte Karasiak
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil;
| | - Tiago Fleming Outeiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany;
- Max Planck Institute for Natural Sciences, 37075 Göttingen, Germany
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle Upon Tyne NE1 7RU, UK
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), 18147 Göttingen, Germany
| | - Alcir Luiz Dafre
- Neuroscience Graduate Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil (A.W.); (A.L.D.)
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil;
| | - Joana Gil-Mohapel
- Island Medical Program, Faculty of Medicine, University of British Columbia and Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Patricia S. Brocardo
- Neuroscience Graduate Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil (A.W.); (A.L.D.)
- Department of Morphological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil
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4
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Grosso Jasutkar H, Yamamoto A. Do Changes in Synaptic Autophagy Underlie the Cognitive Impairments in Huntington's Disease? J Huntingtons Dis 2021; 10:227-238. [PMID: 33780373 PMCID: PMC8293641 DOI: 10.3233/jhd-200466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although Huntington's disease (HD) is classically considered from the perspective of the motor syndrome, the cognitive changes in HD are prominent and often an early manifestation of disease. As such, investigating the underlying pathophysiology of cognitive changes may give insight into important and early neurodegenerative events. In this review, we first discuss evidence from both HD patients and animal models that cognitive changes correlate with early pathological changes at the synapse, an observation that is similarly made in other neurodegenerative conditions that primarily affect cognition. We then describe how autophagy plays a critical role supporting synaptic maintenance in the healthy brain, and how autophagy dysfunction in HD may thereby lead to impaired synaptic maintenance and thus early manifestations of disease.
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Affiliation(s)
| | - Ai Yamamoto
- Department of Neurology, Columbia University, New York, NY, USA.,Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
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5
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Etxeberria-Rekalde E, Alzola-Aldamizetxebarria S, Flunkert S, Hable I, Daurer M, Neddens J, Hutter-Paier B. Quantification of Huntington's Disease Related Markers in the R6/2 Mouse Model. Front Mol Neurosci 2021; 13:617229. [PMID: 33505246 PMCID: PMC7831778 DOI: 10.3389/fnmol.2020.617229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/10/2020] [Indexed: 12/12/2022] Open
Abstract
Huntington’s disease (HD) is caused by an expansion of CAG triplets in the huntingtin gene, leading to severe neuropathological changes that result in a devasting and lethal phenotype. Neurodegeneration in HD begins in the striatum and spreads to other brain regions such as cortex and hippocampus, causing motor and cognitive dysfunctions. To understand the signaling pathways involved in HD, animal models that mimic the human pathology are used. The R6/2 mouse as model of HD was already shown to present major neuropathological changes in the caudate putamen and other brain regions, but recently established biomarkers in HD patients were yet not analyzed in these mice. We therefore performed an in-depth analysis of R6/2 mice to establish new and highly translational readouts focusing on Ctip2 as biological marker for motor system-related neurons and translocator protein (TSPO) as a promising readout for early neuroinflammation. Our results validate already shown pathologies like mutant huntingtin aggregates, ubiquitination, and brain atrophy, but also provide evidence for decreased tyrosine hydroxylase and Ctip2 levels as indicators of a disturbed motor system, while vesicular acetyl choline transporter levels as marker for the cholinergic system barely change. Additionally, increased astrocytosis and activated microglia were observed by GFAP, Iba1 and TSPO labeling, illustrating, that TSPO is a more sensitive marker for early neuroinflammation compared to GFAP and Iba1. Our results thus demonstrate a high sensitivity and translational value of Ctip2 and TSPO as new marker for the preclinical evaluation of new compounds in the R6/2 mouse model of HD.
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Affiliation(s)
| | | | | | - Isabella Hable
- QPS Austria GmbH, Grambach, Austria.,Department of Health Studies, FH Joanneum University of Applied Sciences, Graz, Austria
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6
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Blumenstock S, Dudanova I. Cortical and Striatal Circuits in Huntington's Disease. Front Neurosci 2020; 14:82. [PMID: 32116525 PMCID: PMC7025546 DOI: 10.3389/fnins.2020.00082] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/21/2020] [Indexed: 12/28/2022] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder that typically manifests in midlife with motor, cognitive, and/or psychiatric symptoms. The disease is caused by a CAG triplet expansion in exon 1 of the huntingtin gene and leads to a severe neurodegeneration in the striatum and cortex. Classical electrophysiological studies in genetic HD mouse models provided important insights into the disbalance of excitatory, inhibitory and neuromodulatory inputs, as well as progressive disconnection between the cortex and striatum. However, the involvement of local cortical and striatal microcircuits still remains largely unexplored. Here we review the progress in understanding HD-related impairments in the cortical and basal ganglia circuits, and outline new opportunities that have opened with the development of modern circuit analysis methods. In particular, in vivo imaging studies in mouse HD models have demonstrated early structural and functional disturbances within the cortical network, and optogenetic manipulations of striatal cell types have started uncovering the causal roles of certain neuronal populations in disease pathogenesis. In addition, the important contribution of astrocytes to HD-related circuit defects has recently been recognized. In parallel, unbiased systems biology studies are providing insights into the possible molecular underpinnings of these functional defects at the level of synaptic signaling and neurotransmitter metabolism. With these approaches, we can now reach a deeper understanding of circuit-based HD mechanisms, which will be crucial for the development of effective and targeted therapeutic strategies.
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Affiliation(s)
- Sonja Blumenstock
- Department of Molecules – Signaling – Development, Max Planck Institute of Neurobiology, Martinsried, Germany
- Molecular Neurodegeneration Group, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Irina Dudanova
- Molecular Neurodegeneration Group, Max Planck Institute of Neurobiology, Martinsried, Germany
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7
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Koch ET, Raymond LA. Dysfunctional striatal dopamine signaling in Huntington's disease. J Neurosci Res 2019; 97:1636-1654. [PMID: 31304622 DOI: 10.1002/jnr.24495] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/06/2019] [Accepted: 06/26/2019] [Indexed: 12/17/2022]
Abstract
Dopamine signaling in the striatum is critical for a variety of behaviors including movement, behavioral flexibility, response to reward and many forms of learning. Alterations to dopamine transmission contribute to pathological features of many neurological diseases, including Huntington's disease (HD). HD is an autosomal dominant genetic disorder caused by a CAG repeat expansion in the Huntingtin gene. The striatum is preferentially degenerated in HD, and this region receives dopaminergic input from the substantia nigra. Studies of HD patients and genetic rodent models have shown changes to levels of dopamine and its receptors in the striatum, and alterations in dopamine receptor signaling and modulation of other neurotransmitters, notably glutamate. Throughout his career, Dr. Michael Levine's research has furthered our understanding of dopamine signaling in the striatum of healthy rodents and HD mouse models. This review will focus on the work of his group and others in elucidating alterations to striatal dopamine signaling that contribute to pathophysiology in HD mouse models, and how these findings relate to human HD studies. We will also discuss current and potential therapeutic interventions for HD that target the dopamine system, and future research directions for this field.
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Affiliation(s)
- Ellen T Koch
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada
| | - Lynn A Raymond
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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8
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Yu-Taeger L, Stricker-Shaver J, Arnold K, Bambynek-Dziuk P, Novati A, Singer E, Lourhmati A, Fabian C, Magg J, Riess O, Schwab M, Stolzing A, Danielyan L, Nguyen HHP. Intranasal Administration of Mesenchymal Stem Cells Ameliorates the Abnormal Dopamine Transmission System and Inflammatory Reaction in the R6/2 Mouse Model of Huntington Disease. Cells 2019; 8:E595. [PMID: 31208073 PMCID: PMC6628278 DOI: 10.3390/cells8060595] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/10/2019] [Accepted: 06/13/2019] [Indexed: 12/11/2022] Open
Abstract
Intrastriatal administration of mesenchymal stem cells (MSCs) has shown beneficial effects in rodent models of Huntington disease (HD). However, the invasive nature of surgical procedure and its potential to trigger the host immune response may limit its clinical use. Hence, we sought to evaluate the non-invasive intranasal administration (INA) of MSC delivery as an effective alternative route in HD. GFP-expressing MSCs derived from bone marrow were intranasally administered to 4-week-old R6/2 HD transgenic mice. MSCs were detected in the olfactory bulb, midbrain and striatum five days post-delivery. Compared to phosphate-buffered saline (PBS)-treated littermates, MSC-treated R6/2 mice showed an increased survival rate and attenuated circadian activity disruption assessed by locomotor activity. MSCs increased the protein expression of DARPP-32 and tyrosine hydroxylase (TH) and downregulated gene expression of inflammatory modulators in the brain 7.5 weeks after INA. While vehicle treated R6/2 mice displayed decreased Iba1 expression and altered microglial morphology in comparison to the wild type littermates, MSCs restored both, Iba1 level and the thickness of microglial processes in the striatum of R6/2 mice. Our results demonstrate significantly ameliorated phenotypes of R6/2 mice after MSCs administration via INA, suggesting this method as an effective delivering route of cells to the brain for HD therapy.
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Affiliation(s)
- Libo Yu-Taeger
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Janice Stricker-Shaver
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Katrin Arnold
- Interdisciplinary Centre for Bioinformatics (IZBI), University of Leipzig, D-04107 Leipzig, Germany.
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), D-04103 Leipzig, Germany.
| | - Patrycja Bambynek-Dziuk
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Arianna Novati
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Elisabeth Singer
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Ali Lourhmati
- Department of Clinical Pharmacology, University Hospital of Tuebingen, D-72076 Tuebingen, Germany.
| | - Claire Fabian
- Interdisciplinary Centre for Bioinformatics (IZBI), University of Leipzig, D-04107 Leipzig, Germany.
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), D-04103 Leipzig, Germany.
| | - Janine Magg
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
| | - Matthias Schwab
- Department of Clinical Pharmacology, University Hospital of Tuebingen, D-72076 Tuebingen, Germany.
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, D-70376 Stuttgart, Germany.
- Departments of Biochemistry and Clinical Pharmacology, Yerevan State Medical University, 0025 Yerevan, Armenia.
- Laboratory of Neuroscience, Yerevan State Medical University, 0025 Yerevan, Armenia.
| | - Alexandra Stolzing
- Interdisciplinary Centre for Bioinformatics (IZBI), University of Leipzig, D-04107 Leipzig, Germany.
- Centre for Biological Engineering, School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK.
| | - Lusine Danielyan
- Department of Clinical Pharmacology, University Hospital of Tuebingen, D-72076 Tuebingen, Germany.
- Departments of Biochemistry and Clinical Pharmacology, Yerevan State Medical University, 0025 Yerevan, Armenia.
- Laboratory of Neuroscience, Yerevan State Medical University, 0025 Yerevan, Armenia.
| | - Hoa Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, D-72076 Tuebingen, Germany.
- Centre for Rare Diseases (ZSE), University of Tuebingen, D-72076 Tuebingen, Germany.
- Departments of Biochemistry and Clinical Pharmacology, Yerevan State Medical University, 0025 Yerevan, Armenia.
- Department of Human Genetics, Ruhr University of Bochum, D-44801 Bochum, Germany.
- Departments of Medical Chemistry and Biochemistry, Yerevan State Medical University, 0025 Yerevan, Armenia.
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9
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Smith‐Dijak AI, Sepers MD, Raymond LA. Alterations in synaptic function and plasticity in Huntington disease. J Neurochem 2019; 150:346-365. [DOI: 10.1111/jnc.14723] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 03/28/2019] [Accepted: 05/08/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Amy I. Smith‐Dijak
- Graduate Program in Neuroscience the University of British Columbia Vancouver British Columbia Canada
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health the University of British Columbia Vancouver British Columbia Canada
| | - Marja D. Sepers
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health the University of British Columbia Vancouver British Columbia Canada
| | - Lynn A. Raymond
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health the University of British Columbia Vancouver British Columbia Canada
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10
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Early neurochemical modifications of monoaminergic systems in the R6/1 mouse model of Huntington's disease. Neurochem Int 2019; 128:186-195. [PMID: 31054882 DOI: 10.1016/j.neuint.2019.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/13/2019] [Accepted: 05/01/2019] [Indexed: 01/10/2023]
Abstract
Huntington's disease (HD) is a rare, autosomal neurodegenerative disease characterized by motor and cognitive impairments appearing in adults. The R6/1 mouse model of the disease recapitulates the adult onset of motor symptoms preceded by cognitive and affective deficits. The monoaminergic systems participate in the establishment of motor and cognitive loops and we postulated that their organization and interaction could be precociously altered. Using tissue measurement of dopamine (DA), serotonin (5-HT), noradrenaline, and some metabolites, we observed that DA and/or its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), but not 5-HT or noradrenaline tissue content was reduced in an age-dependent manner (from two to six months) in the striatum, substantia nigra and globus pallidus of R6/1 mice. The metabolite of 5-HT was also lower in R6/1 mice, mainly in the substantia nigra and hippocampus. We then addressed early disorganization of monoaminergic systems in 18 brain regions encompassing several neurobiological networks in 35 day-old animals. DA tissue content was not altered in the striatum or substantia nigra but was decreased in the nucleus accumbens and increased in the globus pallidus. The correlations of monoaminergic index in-between the 18 selected brain regions revealed distinct organizations of monoamines in R6/1 mice, notably marked by a loss of the number of correlations of the DOPAC/DA ratio. The neurochemical analyses show that each monoaminergic system is distinctly altered in the R6/1 mouse model. The early abnormal organization of these systems likely points out altered maturation of neurobiological networks at early stages of HD.
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11
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Jamwal S, Kumar P. Insight Into the Emerging Role of Striatal Neurotransmitters in the Pathophysiology of Parkinson's Disease and Huntington's Disease: A Review. Curr Neuropharmacol 2019; 17:165-175. [PMID: 29512464 PMCID: PMC6343208 DOI: 10.2174/1570159x16666180302115032] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/06/2017] [Accepted: 02/28/2018] [Indexed: 12/05/2022] Open
Abstract
Alteration in neurotransmitters signaling in basal ganglia has been consistently shown to significantly contribute to the pathophysiological basis of Parkinson's disease and Huntington's disease. Dopamine is an important neurotransmitter which plays a critical role in coordinated body movements. Alteration in the level of brain dopamine and receptor radically contributes to irregular movements, glutamate mediated excitotoxic neuronal death and further leads to imbalance in the levels of other neurotransmitters viz. GABA, adenosine, acetylcholine and endocannabinoids. This review is based upon the data from clinical and preclinical studies to characterize the role of various striatal neurotransmitters in the pathogenesis of Parkinson's disease and Huntington's disease. Further, we have collected data of altered level of various neurotransmitters and their metabolites and receptor density in basal ganglia region. Although the exact mechanisms underlying neuropathology of movement disorders are not fully understood, but several mechanisms related to neurotransmitters alteration, excitotoxic neuronal death, oxidative stress, mitochondrial dysfunction, neuroinflammation are being put forward. Restoring neurotransmitters level and downstream signaling has been considered to be beneficial in the treatment of Parkinson's disease and Huntington's disease. Therefore, there is an urgent need to identify more specific drugs and drug targets that can restore the altered neurotransmitters level in brain and prevent/delay neurodegeneration.
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Affiliation(s)
| | - Puneet Kumar
- Address correspondence to this author at the Department of Pharmaceutical Sciences and Technology, Maharaja Ranjit Singh Punjab Technical University, Bathinda, Panjab, India; E-mail:
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12
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Alpaugh M, Galleguillos D, Forero J, Morales LC, Lackey SW, Kar P, Di Pardo A, Holt A, Kerr BJ, Todd KG, Baker GB, Fouad K, Sipione S. Disease-modifying effects of ganglioside GM1 in Huntington's disease models. EMBO Mol Med 2018; 9:1537-1557. [PMID: 28993428 PMCID: PMC5666311 DOI: 10.15252/emmm.201707763] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by motor, cognitive and psychiatric problems. Previous studies indicated that levels of brain gangliosides are lower than normal in HD models and that administration of exogenous ganglioside GM1 corrects motor dysfunction in the YAC128 mouse model of HD In this study, we provide evidence that intraventricular administration of GM1 has profound disease-modifying effects across HD mouse models with different genetic background. GM1 administration results in decreased levels of mutant huntingtin, the protein that causes HD, and in a wide array of beneficial effects that include changes in levels of DARPP32, ferritin, Iba1 and GFAP, modulation of dopamine and serotonin metabolism, and restoration of normal levels of glutamate, GABA, L-Ser and D-Ser. Treatment with GM1 slows down neurodegeneration, white matter atrophy and body weight loss in R6/2 mice. Motor functions are significantly improved in R6/2 mice and restored to normal in Q140 mice, including gait abnormalities that are often resistant to treatments. Psychiatric-like and cognitive dysfunctions are also ameliorated by GM1 administration in Q140 and YAC128 mice. The widespread benefits of GM1 administration, at molecular, cellular and behavioural levels, indicate that this ganglioside has strong therapeutic and disease-modifying potential in HD.
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Affiliation(s)
- Melanie Alpaugh
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Danny Galleguillos
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Juan Forero
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | | | | | - Preeti Kar
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Alba Di Pardo
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Andrew Holt
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Kathryn G Todd
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Glen B Baker
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Karim Fouad
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Simonetta Sipione
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada .,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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13
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Kaplan SV, Limbocker RA, Levant B, Johnson MA. Regional differences in dopamine release in the R6/2 mouse caudate putamen. ELECTROANAL 2018; 30:1066-1072. [PMID: 29955208 PMCID: PMC6016844 DOI: 10.1002/elan.201700827] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/09/2018] [Indexed: 01/23/2023]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disorder that is characterized by degeneration of the striatum. Here, fast-scan cyclic voltammetry at carbon-fiber microelectrodes was used to uncover regional differences in dopamine (DA) release in the caudate putamen of R6/2 and wild-type control mice. We found a decreasing ventral-to-dorsal gradient in DA release, evoked by a single electrical stimulus pulse, in aged R6/2 mice. Moreover, under more intense stimulation conditions (120 pulses), DA release was significantly attenuated in the dorsal, but not in the ventral caudate. Autoradiography measurements using [3H]WIN 35,428 revealed that the overall density of DA transporter (DAT) protein molecules was significantly less in R6/2 mice compared to WT control mice; however, quadrants of the caudate putamen were not differentially altered in the R6/2 mice. These data collectively suggest that DA release in the dorsal caudate region is more vulnerable with age progression compared to the ventral region.
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Affiliation(s)
- Sam V. Kaplan
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045 USA
| | - Ryan A. Limbocker
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045 USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160 USA
| | - Michael A. Johnson
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045 USA
- Neuroscience Program, University of Kansas, Lawrence, Kansas 66045 USA
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Reiner A, Deng Y. Disrupted striatal neuron inputs and outputs in Huntington's disease. CNS Neurosci Ther 2018; 24:250-280. [PMID: 29582587 PMCID: PMC5875736 DOI: 10.1111/cns.12844] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/15/2018] [Accepted: 02/16/2018] [Indexed: 12/22/2022] Open
Abstract
Huntington's disease (HD) is a hereditary progressive neurodegenerative disorder caused by a CAG repeat expansion in the gene coding for the protein huntingtin, resulting in a pathogenic expansion of the polyglutamine tract in the N-terminus of this protein. The HD pathology resulting from the mutation is most prominent in the striatal part of the basal ganglia, and progressive differential dysfunction and loss of striatal projection neurons and interneurons account for the progression of motor deficits seen in this disease. The present review summarizes current understanding regarding the progression in striatal neuron dysfunction and loss, based on studies both in human HD victims and in genetic mouse models of HD. We review evidence on early loss of inputs to striatum from cortex and thalamus, which may be the basis of the mild premanifest bradykinesia in HD, as well as on the subsequent loss of indirect pathway striatal projection neurons and their outputs to the external pallidal segment, which appears to be the basis of the chorea seen in early symptomatic HD. Later loss of direct pathway striatal projection neurons and their output to the internal pallidal segment account for the severe akinesia seen late in HD. Loss of parvalbuminergic striatal interneurons may contribute to the late dystonia and rigidity.
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Affiliation(s)
- Anton Reiner
- Department of Anatomy & NeurobiologyThe University of Tennessee Health Science CenterMemphisTNUSA
- Department of OphthalmologyThe University of Tennessee Health Science CenterMemphisTNUSA
| | - Yun‐Ping Deng
- Department of Anatomy & NeurobiologyThe University of Tennessee Health Science CenterMemphisTNUSA
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15
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Luis-Ravelo D, Estévez-Silva H, Barroso-Chinea P, Afonso-Oramas D, Salas-Hernández J, Rodríguez-Núñez J, Acevedo-Arozena A, Marcellino D, González-Hernández T. Pramipexole reduces soluble mutant huntingtin and protects striatal neurons through dopamine D3 receptors in a genetic model of Huntington's disease. Exp Neurol 2018; 299:137-147. [DOI: 10.1016/j.expneurol.2017.10.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/29/2017] [Accepted: 10/19/2017] [Indexed: 12/26/2022]
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Rangel-Barajas C, Rebec GV. Dysregulation of Corticostriatal Connectivity in Huntington's Disease: A Role for Dopamine Modulation. J Huntingtons Dis 2017; 5:303-331. [PMID: 27983564 PMCID: PMC5181679 DOI: 10.3233/jhd-160221] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aberrant communication between striatum, the main information processing unit of the basal ganglia, and cerebral cortex plays a critical role in the emergence of Huntington’s disease (HD), a fatal monogenetic condition that typically strikes in the prime of life. Although both striatum and cortex undergo substantial cell loss over the course of HD, corticostriatal circuits become dysfunctional long before neurons die. Understanding the dysfunction is key to developing effective strategies for treating a progressively worsening triad of motor, cognitive, and psychiatric symptoms. Cortical output neurons drive striatal activity through the release of glutamate, an excitatory amino acid. Striatal outputs, in turn, release γ-amino butyric acid (GABA) and exert inhibitory control over downstream basal ganglia targets. Ample evidence from transgenic rodent models points to dysregulation of corticostriatal glutamate transmission along with corresponding changes in striatal GABA release as underlying factors in the HD behavioral phenotype. Another contributor is dysregulation of dopamine (DA), a modulator of both glutamate and GABA transmission. In fact, pharmacological manipulation of DA is the only currently available treatment for HD symptoms. Here, we review data from animal models and human patients to evaluate the role of DA in HD, including DA interactions with glutamate and GABA within the context of dysfunctional corticostriatal circuitry.
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Affiliation(s)
| | - George V. Rebec
- Correspondence to: George V. Rebec, PhD, Department of Psychological and Brain Sciences, Program in
Neuroscience, Indiana University, 1101 E. 10th Street, Bloomington, IN 47405-7007, USA. Tel.: +1 812 855 4832;
Fax: +1 812 855 4520; E-mail:
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Compromised Dopaminergic Encoding of Reward Accompanying Suppressed Willingness to Overcome High Effort Costs Is a Prominent Prodromal Characteristic of the Q175 Mouse Model of Huntington's Disease. J Neurosci 2017; 36:4993-5002. [PMID: 27147652 DOI: 10.1523/jneurosci.0135-16.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/15/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Huntington's disease (HD) is a heritable neurodegenerative disorder caused by expansion of CAG (glutamine) repeats in the HTT gene. A prodromal stage characterized by psychiatric disturbances normally precedes primary motor symptoms and suppressed motivation represents one of the earliest and most common psychiatric symptoms. Although dopamine in the nucleus accumbens (NAc) critically regulates motivation and altered dopamine signaling is implicated in HD, the nature of dopaminergic deficits and contribution to symptoms in HD is poorly understood. We therefore tested whether altered NAc dopamine release accompanies motivational deficits in the Q175 knock-in HD mouse model. Q175 mice express a CAG expansion of the human mutant huntingtin allele in the native mouse genome and gradually manifest symptoms late in life, closely mimicking the genotypic context and disease progression in human HD. Sub-second extracellular dopamine release dynamics were monitored using fast-scan cyclic voltammetry, whereas motivation was assessed using a progressive ratio reinforcement schedule. As the response ratio (lever presses per reward) escalated, Q175 mice exerted less effort to earn fewer rewards versus wild-type (WT). Moreover, dopamine released at reward delivery dynamically encoded increasing reward cost in WT but not Q175 mice. Deficits were specific to situations of high effortful demand as no difference was observed in locomotion, free feeding, hedonic processing, or reward seeking when the response requirement was low. This compromised dopaminergic encoding of reward delivery coincident with suppressed motivation to work for reward in Q175 mice provides novel, neurobiological insight into an established and clinically relevant endophenotype of prodromal HD. SIGNIFICANCE STATEMENT Psychiatric impairments in Huntington's disease (HD) typically manifest early in disease progression, before motor deficits. However, the neurobiological factors contributing to psychiatric symptoms are poorly understood. We used a mouse HD model and assessed whether impaired dopamine release in the nucleus accumbens (NAc), a brain region critical to goal-directed behaviors, accompanies motivational deficits, one of the most common early HD symptoms. HD mice exhibited blunted motivation to work for food reward coincident with diminished dopamine release to reward receipt. Motivational and NAc dopaminergic deficits were not associated with gross motor deficits or impaired food seeking when effortful demands were low. This work identifies a specific prodromal HD phenotype associated with a prominent and previously unidentified neurobiological impairment.
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Tyebji S, Hannan AJ. Synaptopathic mechanisms of neurodegeneration and dementia: Insights from Huntington's disease. Prog Neurobiol 2017; 153:18-45. [PMID: 28377290 DOI: 10.1016/j.pneurobio.2017.03.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 03/19/2017] [Accepted: 03/30/2017] [Indexed: 12/20/2022]
Abstract
Dementia encapsulates a set of symptoms that include loss of mental abilities such as memory, problem solving or language, and reduces a person's ability to perform daily activities. Alzheimer's disease is the most common form of dementia, however dementia can also occur in other neurological disorders such as Huntington's disease (HD). Many studies have demonstrated that loss of neuronal cell function manifests pre-symptomatically and thus is a relevant therapeutic target to alleviate symptoms. Synaptopathy, the physiological dysfunction of synapses, is now being approached as the target for many neurological and psychiatric disorders, including HD. HD is an autosomal dominant and progressive degenerative disorder, with clinical manifestations that encompass movement, cognition, mood and behaviour. HD is one of the most common tandem repeat disorders and is caused by a trinucleotide (CAG) repeat expansion, encoding an extended polyglutamine tract in the huntingtin protein. Animal models as well as human studies have provided detailed, although not exhaustive, evidence of synaptic dysfunction in HD. In this review, we discuss the neuropathology of HD and how the changes in synaptic signalling in the diseased brain lead to its symptoms, which include dementia. Here, we review and discuss the mechanisms by which the 'molecular orchestras' and their 'synaptic symphonies' are disrupted in neurodegeneration and dementia, focusing on HD as a model disease. We also explore the therapeutic strategies currently in pre-clinical and clinical testing that are targeted towards improving synaptic function in HD.
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Affiliation(s)
- Shiraz Tyebji
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia.
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Bunner KD, Rebec GV. Corticostriatal Dysfunction in Huntington's Disease: The Basics. Front Hum Neurosci 2016; 10:317. [PMID: 27445757 PMCID: PMC4924423 DOI: 10.3389/fnhum.2016.00317] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/13/2016] [Indexed: 11/23/2022] Open
Abstract
The main input to the basal ganglia, the corticostriatal pathway, shows some of the earliest signs of neuropathology in Huntington’s disease (HD), an inherited neurodegenerative condition that typically strikes in mid-life with progressively deteriorating cognitive, emotional, and motor symptoms. Although an effective treatment remains elusive, research on transgenic animal models has implicated dysregulation of glutamate (Glu), the excitatory amino acid released by corticostriatal neurons, in HD onset. Abnormalities in the control of Glu transmission at the level of postsynaptic receptors and Glu transport proteins play a critical role in the loss of information flow through downstream circuits that set the stage for the HD behavioral phenotype. Parallel but less-well characterized changes in dopamine (DA), a key modulator of Glu activation, ensure further deficits in neuronal communication throughout the basal ganglia. Continued analysis of corticostriatal Glu transmission and its modulation by DA, including analysis at the neurobehavioral level in transgenic models, is likely to be an effective strategy in the pursuit of HD therapeutics.
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Affiliation(s)
- Kendra D Bunner
- Department of Psychological and Brain Sciences, Program in Neuroscience, Indiana University Bloomington, IN, USA
| | - George V Rebec
- Department of Psychological and Brain Sciences, Program in Neuroscience, Indiana University Bloomington, IN, USA
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Garcia-Miralles M, Ooi J, Ferrari Bardile C, Tan LJ, George M, Drum CL, Lin RY, Hayden MR, Pouladi MA. Treatment with the MAO-A inhibitor clorgyline elevates monoamine neurotransmitter levels and improves affective phenotypes in a mouse model of Huntington disease. Exp Neurol 2016; 278:4-10. [DOI: 10.1016/j.expneurol.2016.01.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 01/08/2016] [Accepted: 01/24/2016] [Indexed: 01/03/2023]
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Rothe T, Deliano M, Wójtowicz AM, Dvorzhak A, Harnack D, Paul S, Vagner T, Melnick I, Stark H, Grantyn R. Pathological gamma oscillations, impaired dopamine release, synapse loss and reduced dynamic range of unitary glutamatergic synaptic transmission in the striatum of hypokinetic Q175 Huntington mice. Neuroscience 2015; 311:519-38. [PMID: 26546830 DOI: 10.1016/j.neuroscience.2015.10.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/20/2015] [Accepted: 10/21/2015] [Indexed: 11/28/2022]
Abstract
Huntington's disease (HD) is a severe genetically inherited neurodegenerative disorder. Patients present with three principal phenotypes of motor symptoms: choreatic, hypokinetic-rigid and mixed. The Q175 mouse model of disease offers an opportunity to investigate the cellular basis of the hypokinetic-rigid form of HD. At the age of 1 year homozygote Q175 mice exhibited the following signs of hypokinesia: Reduced frequency of spontaneous movements on a precision balance at daytime (-55%), increased total time spent without movement in an open field (+42%), failures in the execution of unconditioned avoidance reactions (+32%), reduced ability for conditioned avoidance (-96%) and increased reaction times (+65%) in a shuttle box. Local field potential recordings revealed low-frequency gamma oscillations in the striatum as a characteristic feature of HD mice at rest. There was no significant loss of DARPP-32 immunolabeled striatal projection neurons (SPNs) although the level of DARPP-32 immunoreactivity was lower in HD. As a potential cause of hypokinesia, HD mice revealed a strong reduction in striatal KCl-induced dopamine release, accompanied by a decrease in the number of tyrosine hydroxylase-(TH)- and VMAT2-positive synaptic varicosities. The presynaptic TH fluorescence level was also reduced. Patch-clamp experiments were performed in slices from 1-year-old mice to record unitary EPSCs (uEPSCs) of presumed cortical origin in the absence of G-protein-mediated modulation. In HD mice, the maximal amplitudes of uEPSCs amounted to 69% of the WT level which matches the loss of VGluT1+/SYP+ synaptic terminals in immunostained sections. These results identify impairment of cortico-striatal synaptic transmission and dopamine release as a potential basis of hypokinesia in HD.
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Affiliation(s)
- T Rothe
- Leibniz Institute for Neurobiology Magdeburg, Germany
| | - M Deliano
- Leibniz Institute for Neurobiology Magdeburg, Germany
| | | | - A Dvorzhak
- Cluster of Excellence NeuroCure, Berlin, Germany
| | - D Harnack
- Department of Experimental Neurology, University Medicine Charité, Berlin, Germany
| | - S Paul
- Cluster of Excellence NeuroCure, Berlin, Germany
| | - T Vagner
- Cluster of Excellence NeuroCure, Berlin, Germany
| | - I Melnick
- Cluster of Excellence NeuroCure, Berlin, Germany; Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - H Stark
- Leibniz Institute for Neurobiology Magdeburg, Germany
| | - R Grantyn
- Cluster of Excellence NeuroCure, Berlin, Germany; Department of Experimental Neurology, University Medicine Charité, Berlin, Germany.
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22
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Allosteric activation of M4 muscarinic receptors improve behavioral and physiological alterations in early symptomatic YAC128 mice. Proc Natl Acad Sci U S A 2015; 112:14078-83. [PMID: 26508634 DOI: 10.1073/pnas.1512812112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Mutations that lead to Huntington's disease (HD) result in increased transmission at glutamatergic corticostriatal synapses at early presymptomatic stages that have been postulated to set the stage for pathological changes and symptoms that are observed at later ages. Based on this, pharmacological interventions that reverse excessive corticostriatal transmission may provide a novel approach for reducing early physiological changes and motor symptoms observed in HD. We report that activation of the M4 subtype of muscarinic acetylcholine receptor reduces transmission at corticostriatal synapses and that this effect is dramatically enhanced in presymptomatic YAC128 HD and BACHD relative to wild-type mice. Furthermore, chronic administration of a novel highly selective M4 positive allosteric modulator (PAM) beginning at presymptomatic ages improves motor and synaptic deficits in 5-mo-old YAC128 mice. These data raise the exciting possibility that selective M4 PAMs could provide a therapeutic strategy for the treatment of HD.
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Callahan JW, Abercrombie ED. Relationship between subthalamic nucleus neuronal activity and electrocorticogram is altered in the R6/2 mouse model of Huntington's disease. J Physiol 2015; 593:3727-38. [PMID: 25952461 DOI: 10.1113/jp270268] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 05/05/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Neural synchrony between the subthalamic nucleus (STN) and cortex is critical for proper information processing in basal ganglia circuits. Using in vivo extracellular recordings in urethane-anaesthetized mice, we demonstrate that single units and local field potentials from the STN exhibit oscillatory entrainment to low-frequency (0.5-4 Hz) rhythms when the cortex is in a synchronized state. Here we report novel findings in the R6/2 transgenic mouse model of Huntington's disease (HD) by demonstrating that STN activity is reduced and less phase-locked to cortical low-frequency oscillations. The spectral power of low-frequency oscillations in ECoG recordings of R6/2 mice is diminished while the spectral power of higher frequencies is augmented and such altered cortical patterning could lead to decreased synchrony in corticosubthalamic circuits. Our data establish that cortical entrainment of STN neural activity is disrupted in R6/2 mice and may be one of the mechanisms contributing to disordered motor control in HD. ABSTRACT Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder in which impairments in the processing of information between the cortex and basal ganglia are fundamental to the onset and progression of the HD phenotype. The corticosubthalamic hyperdirect pathway plays a pivotal role in motor selection and blockade of neuronal activity in the subthalamic nucleus (STN) results in a hyperkinetic movement syndrome, similar to the HD phenotype. The aim of the present study was to examine the relationship between neuronal activity in the STN and cortex in an animal model of HD. We performed in vivo extracellular recordings in the STN to measure single-unit activity and local field potentials in the R6/2 transgenic mouse model of HD. These recordings were obtained during epochs of simultaneously acquired electrocorticogram (ECoG) in discrete brain states representative of global cortical network synchronization or desynchronization. Cortically patterned STN neuronal activity was less phase-locked in R6/2 mice, which is likely to result in less efficient coding of cortical inputs by the basal ganglia. In R6/2 mice, the power of the ECoG in lower frequencies (0.5-4 Hz) was diminished while the power expressed in higher frequencies (13-100 Hz) was increased. In addition, the spontaneous activity of STN neurons in R6/2 mice was reduced and neurons exhibited a more irregular firing pattern. Glutamatergic STN neurons provide the major excitatory drive to the output nuclei of the basal ganglia and altered discharge patterns could lead to aberrant basal ganglia output and disordered motor control in HD.
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Affiliation(s)
- Joshua W Callahan
- Center for Molecular and Behavioural Neuroscience, Rutgers University, Newark, NJ, 07102, USA
| | - Elizabeth D Abercrombie
- Center for Molecular and Behavioural Neuroscience, Rutgers University, Newark, NJ, 07102, USA
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24
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Deffains M, Bergman H. Striatal cholinergic interneurons and cortico-striatal synaptic plasticity in health and disease. Mov Disord 2015; 30:1014-25. [PMID: 26095280 DOI: 10.1002/mds.26300] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 12/11/2022] Open
Abstract
Basal ganglia disorders such as Parkinson's disease, dystonia, and Huntington's disease are characterized by a dysregulation of the basal ganglia neuromodulators (dopamine, acetylcholine, and others), which impacts cortico-striatal transmission. Basal ganglia disorders are often associated with an imbalance between the midbrain dopaminergic and striatal cholinergic systems. In contrast to the extensive research and literature on the consequences of a malfunction of midbrain dopaminergic signaling on the plasticity of the cortico-striatal synapse, very little is known about the role of striatal cholinergic interneurons in normal and pathological control of cortico-striatal transmission. In this review, we address the functional role of striatal cholinergic interneurons, also known as tonically active neurons and attempt to understand how the alteration of their functional properties in basal ganglia disorders leads to abnormal cortico-striatal synaptic plasticity. Specifically, we suggest that striatal cholinergic interneurons provide a permissive signal, which enables long-term changes in the efficacy of the cortico-striatal synapse. We further discuss how modifications in the striatal cholinergic activity pattern alter or prohibit plastic changes of the cortico-striatal synapse. Long-term cortico-striatal synaptic plasticity is the cellular substrate of procedural learning and adaptive control behavior. Hence, abnormal changes in this plasticity may underlie the inability of patients with basal ganglia disorders to adjust their behavior to situational demands. Normalization of the cholinergic modulation of cortico-striatal synaptic plasticity may be considered as a critical feature in future treatments of basal ganglia disorders.
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Affiliation(s)
- Marc Deffains
- Department of Medical Neurobiology (Physiology), Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel.,The Edmond and Lily Safra Center (ELSC) for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Hagai Bergman
- Department of Medical Neurobiology (Physiology), Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel.,The Edmond and Lily Safra Center (ELSC) for Brain Sciences, The Hebrew University, Jerusalem, Israel
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25
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Neuroanatomical Visualization of the Impaired Striatal Connectivity in Huntington's Disease Mouse Model. Mol Neurobiol 2015; 53:2276-86. [PMID: 25976370 DOI: 10.1007/s12035-015-9214-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
Abstract
Huntington's disease (HD) is a movement disorder characterized by the early selective degeneration of striatum. For motor control, the striatum receives excitatory inputs from multiple brain regions and projects the information to other basal ganglia nuclei. Despite the pathological importance of the striatal degeneration in HD, there are little anatomical data that show impaired striatal connectivity in HD. For the anatomical mapping of the striatum, we injected here a neurotracer DiD to the dorsal striatum of HD mouse model (YAC128). Compared with littermate controls, the number of the traced inputs to the striatum was reduced dramatically in YAC128 mice at 12 months of age suggesting massive destruction of the striatal connections. Basal ganglia inputs were significantly damaged in HD mice by showing 61 % decrease in substantia nigra pars compacta, 85% decrease in thalamic centromedian nucleus, and 55% decrease in thalamic parafascicular nucleus. Cortical inputs were also greatly decreased by 43% in motor cortex, 48% in somatosensory cortex, and 72% in visual cortex. Besides the known striatal connections, the neurotracer DiD also traced inputs from amygdala and the amygdala inputs were decreased by 68% in YAC128 mice. Considering the role of amygdala in emotion processing, the impairment in amygdalostriatal connectivity strongly suggests that emotional disturbances could occur in HD mice. Indeed, open-field tests further indicated that YAC128 mice exhibited changes in emotional behaviors related to symptoms of depression and anxiety. Although onset of HD is clinically determined on the basis of motor abnormality, emotional deficits are also common features of the disease. Therefore, our anatomical connectivity mapping of the striatum provides a new insight to interpret brain dysfunction in HD.
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26
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Dallérac GM, Levasseur G, Vatsavayai SC, Milnerwood AJ, Cummings DM, Kraev I, Huetz C, Evans KA, Walters SW, Rezaie P, Cho Y, Hirst MC, Murphy KP. Dysfunctional Dopaminergic Neurones in Mouse Models of Huntington's Disease: A Role for SK3 Channels. NEURODEGENER DIS 2015; 15:93-108. [DOI: 10.1159/000375126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/12/2015] [Indexed: 11/19/2022] Open
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27
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Schwab LC, Garas SN, Garas SN, Drouin-Ouellet J, Mason SL, Stott SR, Barker RA. Dopamine and Huntington's disease. Expert Rev Neurother 2015; 15:445-58. [PMID: 25773746 DOI: 10.1586/14737175.2015.1025383] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Huntington's disease (HD) is an incurable, inherited, progressive neurodegenerative disorder that is defined by a combination of motor, cognitive and psychiatric features. Pre-clinical and clinical studies have demonstrated an important role for the dopamine (DA) system in HD with dopaminergic dysfunction at the level of both DA release and DA receptors. It is, therefore, not surprising that the drug treatments most commonly used in HD are anti-dopaminergic agents. Their use is based primarily on the belief that the characteristic motor impairments are a result of overactivation of the central dopaminergic pathways. While this is a useful starting place, it is clear that the behavior of the central dopaminergic pathways is not fully understood in this condition and may change as a function of disease stage. In addition, how abnormalities in dopaminergic systems may underlie some of the non-motor features of HD has also been poorly investigated and this is especially important given the greater burden these place on the patients' and families' quality of life. In this review, we discuss what is known about central dopaminergic pathways in HD and how this informs us about the mechanisms of action of the dopaminergic therapies used to treat it. By doing so, we will highlight some of the paradoxes that exist and how solving them may reveal new insights for improved treatment of this currently incurable condition, including the possibility that such drugs may even have effects on disease progression and pathogenesis.
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Affiliation(s)
- Laetitia C Schwab
- John van Geest Centre for Brain Repair, University of Cambridge, E.D. Adrian Building, Forvie Site, Robinson Way, Cambridge, CB2 0PY, UK
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28
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Laprairie RB, Bagher AM, Precious SV, Denovan-Wright EM. Components of the endocannabinoid and dopamine systems are dysregulated in Huntington's disease: analysis of publicly available microarray datasets. Pharmacol Res Perspect 2015; 3:e00104. [PMID: 25692022 PMCID: PMC4317235 DOI: 10.1002/prp2.104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 08/20/2014] [Accepted: 09/28/2014] [Indexed: 01/20/2023] Open
Abstract
The endocannabinoid system (ECS) and the dopaminergic system (DAS) are two major regulators of basal ganglia function. During Huntington's disease (HD) pathogenesis, the expression of genes in both the ECS and DAS is dysregulated. The purpose of this study was to determine the changes that were consistently observed in the ECS and DAS during HD progression in the central nervous system (CNS) and in the periphery in different models of HD and human HD tissue. To do this, we conducted a meta-analysis of differential gene expression in the ECS and DAS using publicly available microarray data. The consolidated data were summarized as observed changes in gene expression (OCGE) using a weighted sum for each gene. In addition, consolidated data were compared to previously published studies that were not available in the gene expression omnibus (GEO) database. The resulting data confirm gene expression changes observed using different approaches and provide novel insights into the consistency between changes observed in human tissue and various models, as well as disease stage- and tissue-specific transcriptional dysregulation in HD. The major implication of the systems-wide data presented here is that therapeutic strategies targeting the ECS or DAS must consider the dynamic changes in gene expression over time and in different body areas, which occur during HD progression and the interconnectedness of the two systems.
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Affiliation(s)
- Robert B Laprairie
- Department of Pharmacology, Dalhousie UniversityHalifax, NS, Canada, B3H 4R2
| | - Amina M Bagher
- Department of Pharmacology, Dalhousie UniversityHalifax, NS, Canada, B3H 4R2
| | - Sophie V Precious
- Department of Pharmacology, Dalhousie UniversityHalifax, NS, Canada, B3H 4R2
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Abstract
In this review, we explore the similarities and differences in the behavioural neurobiology found in the mouse models of Huntington's disease (HD) and the human disease state. The review is organised with a comparative focus on the functional domains of motor control, cognition and behavioural disturbance (akin to psychiatric disturbance in people) and how our knowledge of the underlying physiological changes that are manifest in the HD mouse lines correspond to those seen in the HD clinical population. The review is framed in terms of functional circuitry and neurotransmitter systems and how abnormalities in these systems impact on the behavioural readouts across the mouse lines and how these may correspond to the deficits observed in people. In addition, interpretational issues associated with the data from animal studies are discussed.
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Affiliation(s)
- Simon P Brooks
- Brain Repair Group, Division of Neuroscience, Cardiff University School of Bioscience, Museum Avenue, Cardiff, Wales, UK,
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Inhibition of Excessive Monoamine Oxidase A/B Activity Protects Against Stress-induced Neuronal Death in Huntington Disease. Mol Neurobiol 2014; 52:1850-1861. [PMID: 25398695 PMCID: PMC4586002 DOI: 10.1007/s12035-014-8974-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/29/2014] [Indexed: 01/20/2023]
Abstract
Monoamine oxidases (MAO) are important components of the homeostatic machinery that maintains the levels of monoamine neurotransmitters, including dopamine, in balance. Given the imbalance in dopamine levels observed in Huntington disease (HD), the aim of this study was to examine MAO activity in a mouse striatal cell model of HD and in human neural cells differentiated from control and HD patient-derived induced pluripotent stem cell (hiPSC) lines. We show that mouse striatal neural cells expressing mutant huntingtin (HTT) exhibit increased MAO expression and activity. We demonstrate using luciferase promoter assays that the increased MAO expression reflects enhanced epigenetic activation in striatal neural cells expressing mutant HTT. Using cellular stress paradigms, we further demonstrate that the increase in MAO activity in mutant striatal neural cells is accompanied by enhanced susceptibility to oxidative stress and impaired viability. Treatment of mutant striatal neural cells with MAO inhibitors ameliorated oxidative stress and improved cellular viability. Finally, we demonstrate that human HD neural cells exhibit increased MAO-A and MAO-B expression and activity. Altogether, this study demonstrates abnormal MAO expression and activity and suggests a potential use for MAO inhibitors in HD.
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31
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Kaizaki A, Tanaka S, Numazawa S. New recreational drug 1-phenyl-2-(1-pyrrolidinyl)-1-pentanone (alpha-PVP) activates central nervous system via dopaminergic neuron. J Toxicol Sci 2014; 39:1-6. [PMID: 24418703 DOI: 10.2131/jts.39.1] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
1-phenyl-2-(1-pyrrolidinyl)-1-pentanone (α-PVP) is a new designer drug of the cathinone type. People who have taken drugs containing α-PVP or other synthetic cathinone reportedly lose consciousness, develop difficulty breathing, and at worst case, die. However, the mechanism underlying α-PVP-induced neurotoxicity is unknown. The objective of the present study was to investigate the effect of α-PVP on the central nervous system (CNS) and compare its neurotoxicity with that of methamphetamine (METH) in mice. Balb/c male mice (8 weeks old) were orally administered α-PVP (25 mg/kg) or METH (5 mg/kg). α-PVP induced a significant increase in locomotor activity, which occurred earlier than locomotor activity induced by METH. This increase was inhibited by the D1 receptor antagonist SCH23990 (50 µg/kg, i.p.) and the D2 receptor antagonist sulpiride (50 mg/kg, i.m.). The extracellular concentration of dopamine (DA) in the striatum, determined by in vivo microdialysis increased immediately after α-PVP administration. These results suggest that α-PVP stimulates DA release, causing an increase in locomotor activity, and that this stimulatory effect of α-PVP on CNS is mediated, at least in part, by the D1 and D2 receptors.
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Affiliation(s)
- Asuka Kaizaki
- Division of Toxicology, Department of Pharmacology, Toxicology and Therapeutics, Showa University School of Pharmacy
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32
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Smith GA, Rocha EM, McLean JR, Hayes MA, Izen SC, Isacson O, Hallett PJ. Progressive axonal transport and synaptic protein changes correlate with behavioral and neuropathological abnormalities in the heterozygous Q175 KI mouse model of Huntington's disease. Hum Mol Genet 2014; 23:4510-27. [PMID: 24728190 DOI: 10.1093/hmg/ddu166] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A long-term goal of modeling Huntington's disease (HD) is to recapitulate the cardinal features of the disease in mice that express both mutant and wild-type (WT) huntingtin (Htt), as HD commonly manifests as a heterozygous condition in humans, and loss of WT Htt is associated with loss-of-function. In a new heterozygous Q175 knock-in (KI) mouse model, we performed an extensive evaluation of motor and cognitive functional deficits, neuropathological and biochemical changes and levels of proteins involved in synaptic function, the cytoskeleton and axonal transport, at 1-16 months of age. Motor deficits were apparent at 6 months of age in Q175 KI mice and at that time, postmortem striatal gamma-aminobutyric acid (GABA) levels were elevated and mutant Htt inclusions were present throughout the brain. From 6 months of age, levels of proteins associated with synaptic function, including SNAP-25, Rab3A and PSD-95, and with axonal transport and microtubules, including KIF3A, dynein and dynactin, were altered in the striatum, motor cortex, prefrontal cortex and hippocampus of Q175 KI mice, compared with WT levels. At 12-16 months of age, Q175 KI mice displayed motor and cognitive deficits, which were paralleled at postmortem by striatal atrophy, cortical thinning, degeneration of medium spiny neurons, dense mutant Htt inclusion formation, decreased striatal dopamine levels and loss of striatal brain-derived neurotrophic factor (BDNF). Data from this study indicate that the heterozygous Q175 KI mouse represents a realistic model for HD and also provides new insights into the specific and progressive synaptic, cytoskeletal and axonal transport protein abnormalities that may accompany the disease.
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Affiliation(s)
- Gaynor A Smith
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
| | - Emily M Rocha
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
| | - Jesse R McLean
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
| | - Melissa A Hayes
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
| | - Sarah C Izen
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
| | - Ole Isacson
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
| | - Penelope J Hallett
- McLean Hospital/Harvard Medical School, Neuroregeneration Research Institute and Laboratories, Belmont, MA, USA
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33
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Cepeda C, Murphy KPS, Parent M, Levine MS. The role of dopamine in Huntington's disease. PROGRESS IN BRAIN RESEARCH 2014; 211:235-54. [PMID: 24968783 PMCID: PMC4409123 DOI: 10.1016/b978-0-444-63425-2.00010-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alterations in dopamine (DA) neurotransmission in Parkinson's disease are well known and widely studied. Much less is known about DA changes that accompany and underlie some of the symptoms of Huntington's disease (HD), a dominant inherited neurodegenerative disorder characterized by chorea, cognitive deficits, and psychiatric disturbances. The cause is an expansion in CAG (glutamine) repeats in the HTT gene. The principal histopathology of HD is the loss of medium-sized spiny neurons (MSNs) and, to a lesser degree, neuronal loss in cerebral cortex, thalamus, hippocampus, and hypothalamus. Neurochemical, electrophysiological, and behavioral studies in HD patients and genetic mouse models suggest biphasic changes in DA neurotransmission. In the early stages, DA neurotransmission is increased leading to hyperkinetic movements that can be alleviated by depleting DA stores. In contrast, in the late stages, DA deficits produce hypokinesia that can be treated by increasing DA function. Alterations in DA neurotransmission affect glutamate receptor modulation and could contribute to excitotoxicity. The mechanisms of DA dysfunction, in particular the increased DA tone in the early stages of the disease, are presently unknown but may include initial upregulation of DA neuron activity caused by the genetic mutation, reduced inhibition resulting from striatal MSN loss, increased excitation from cortical inputs, and DA autoreceptor dysfunction. Targeting both DA and glutamate receptor dysfunction could be the best strategy to treat HD symptoms.
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Affiliation(s)
- Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Kerry P S Murphy
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, Buckinghamshire, UK
| | - Martin Parent
- Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec City, QC, Canada
| | - Michael S Levine
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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Increased Body Weight of the BAC HD Transgenic Mouse Model of Huntington's Disease Accounts for Some but Not All of the Observed HD-like Motor Deficits. PLOS CURRENTS 2013; 5. [PMID: 24042107 PMCID: PMC3770835 DOI: 10.1371/currents.hd.0ab4f3645aff523c56ecc8ccbe41a198] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The genome of the Bacterial Artificial Chromosome (BAC) transgenic mouse model of Huntington’s Disease (BAC HD) contains the 170 kb human HTT locus modified by the addition of exon 1 with 97 mixed CAA-CAG repeats. BAC HD mice present robust behavioral deficits in both the open field and the accelerating rotarod tests, two standard behavioral assays of motor function. BAC HD mice, however, also typically present significantly increased body weights relative to wildtype littermate controls (WT) which potentially confounds the interpretation of any motor deficits associated directly with the effects of mutant huntingtin. In order to evaluate this possible confound of body weight, we directly compared the performance of BAC HD and WT female mice under food restricted versus free feeding conditions in both the open field and rotarod tasks to test the hypothesis that some of the motor deficits observed in this HTT-transgenic mouse line results solely from increased body weight. Our results suggest that the rotarod deficit exhibited by BAC HD mice is modulated by both body weight and non-body weight factors resulting from overexpression of full length mutant Htt. When body weights of WT and BAC HD transgenic mice were normalized using restricted feeding, the deficits exhibited by BAC HD mice on the rotarod task were less marked, but were still significant. Since the rotarod deficit between WT and BAC HD mice is attenuated when body weight is normalized by food restriction, utilization of this task in BAC HD mice during pre-clinical evaluation must be powered accordingly and results carefully considered as therapeutic benefit can result from decreased overall body weight and or motoric improvement that may not be related to body mass. Furthermore, after controlling for body weight differences, the hypoactive phenotype displayed by ad libitum fed BAC HD mice in the open field assay was not observed in the BAC HD mice undergoing food restriction. These findings suggest that assessment of spontaneous locomotor activity, as measured in the open field test, may not be the appropriate behavioral endpoint to evaluate the BAC HD mouse during preclinical evaluation since it appears that the apparent hypoactive phenotype in this model is driven primarily by body weight differences.
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35
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Chen JY, Wang EA, Cepeda C, Levine MS. Dopamine imbalance in Huntington's disease: a mechanism for the lack of behavioral flexibility. Front Neurosci 2013; 7:114. [PMID: 23847463 PMCID: PMC3701870 DOI: 10.3389/fnins.2013.00114] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/13/2013] [Indexed: 01/10/2023] Open
Abstract
Dopamine (DA) plays an essential role in the control of coordinated movements. Alterations in DA balance in the striatum lead to pathological conditions such as Parkinson's and Huntington's diseases (HD). HD is a progressive, invariably fatal neurodegenerative disease caused by a genetic mutation producing an expansion of glutamine repeats and is characterized by abnormal dance-like movements (chorea). The principal pathology is the loss of striatal and cortical projection neurons. Changes in brain DA content and receptor number contribute to abnormal movements and cognitive deficits in HD. In particular, during the early hyperkinetic stage of HD, DA levels are increased whereas expression of DA receptors is reduced. In contrast, in the late akinetic stage, DA levels are significantly decreased and resemble those of a Parkinsonian state. Time-dependent changes in DA transmission parallel biphasic changes in glutamate synaptic transmission and may enhance alterations in glutamate receptor-mediated synaptic activity. In this review, we focus on neuronal electrophysiological mechanisms that may lead to some of the motor and cognitive symptoms of HD and how they relate to dysfunction in DA neurotransmission. Based on clinical and experimental findings, we propose that some of the behavioral alterations in HD, including reduced behavioral flexibility, may be caused by altered DA modulatory function. Thus, restoring DA balance alone or in conjunction with glutamate receptor antagonists could be a viable therapeutic approach.
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Affiliation(s)
- Jane Y Chen
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior and the Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles Los Angeles, CA, USA
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36
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Horne EA, Coy J, Swinney K, Fung S, Cherry AET, Marrs WR, Naydenov AV, Lin YH, Sun X, Keene CD, Grouzmann E, Muchowski P, Bates GP, Mackie K, Stella N. Downregulation of cannabinoid receptor 1 from neuropeptide Y interneurons in the basal ganglia of patients with Huntington's disease and mouse models. Eur J Neurosci 2012; 37:429-40. [PMID: 23167744 DOI: 10.1111/ejn.12045] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 09/20/2012] [Accepted: 10/01/2012] [Indexed: 11/29/2022]
Abstract
Cannabinoid receptor 1 (CB(1) receptor) controls several neuronal functions, including neurotransmitter release, synaptic plasticity, gene expression and neuronal viability. Downregulation of CB(1) expression in the basal ganglia of patients with Huntington's disease (HD) and animal models represents one of the earliest molecular events induced by mutant huntingtin (mHtt). This early disruption of neuronal CB(1) signaling is thought to contribute to HD symptoms and neurodegeneration. Here we determined whether CB(1) downregulation measured in patients with HD and mouse models was ubiquitous or restricted to specific striatal neuronal subpopulations. Using unbiased semi-quantitative immunohistochemistry, we confirmed previous studies showing that CB(1) expression is downregulated in medium spiny neurons of the indirect pathway, and found that CB(1) is also downregulated in neuropeptide Y (NPY)/neuronal nitric oxide synthase (nNOS)-expressing interneurons while remaining unchanged in parvalbumin- and calretinin-expressing interneurons. CB(1) downregulation in striatal NPY/nNOS-expressing interneurons occurs in R6/2 mice, Hdh(Q150/Q150) mice and the caudate nucleus of patients with HD. In R6/2 mice, CB(1) downregulation in NPY/nNOS-expressing interneurons correlates with diffuse expression of mHtt in the soma. This downregulation also occludes the ability of cannabinoid agonists to activate the pro-survival signaling molecule cAMP response element-binding protein in NPY/nNOS-expressing interneurons. Loss of CB(1) signaling in NPY/nNOS-expressing interneurons could contribute to the impairment of basal ganglia functions linked to HD.
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Affiliation(s)
- Eric A Horne
- Department of Pharmacology, University of Washington, 1959 N.E. Pacific St., Seattle, WA 98195-7280, USA
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37
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Figiel M, Szlachcic WJ, Switonski PM, Gabka A, Krzyzosiak WJ. Mouse models of polyglutamine diseases: review and data table. Part I. Mol Neurobiol 2012; 46:393-429. [PMID: 22956270 PMCID: PMC3461215 DOI: 10.1007/s12035-012-8315-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Accepted: 07/29/2012] [Indexed: 12/23/2022]
Abstract
Polyglutamine (polyQ) disorders share many similarities, such as a common mutation type in unrelated human causative genes, neurological character, and certain aspects of pathogenesis, including morphological and physiological neuronal alterations. The similarities in pathogenesis have been confirmed by findings that some experimental in vivo therapy approaches are effective in multiple models of polyQ disorders. Additionally, mouse models of polyQ diseases are often highly similar between diseases with respect to behavior and the features of the disease. The common features shared by polyQ mouse models may facilitate the investigation of polyQ disorders and may help researchers explore the mechanisms of these diseases in a broader context. To provide this context and to promote the understanding of polyQ disorders, we have collected and analyzed research data about the characterization and treatment of mouse models of polyQ diseases and organized them into two complementary Excel data tables. The data table that is presented in this review (Part I) covers the behavioral, molecular, cellular, and anatomic characteristics of polyQ mice and contains the most current knowledge about polyQ mouse models. The structure of this data table is designed in such a way that it can be filtered to allow for the immediate retrieval of the data corresponding to a single mouse model or to compare the shared and unique aspects of many polyQ models. The second data table, which is presented in another publication (Part II), covers therapeutic research in mouse models by summarizing all of the therapeutic strategies employed in the treatment of polyQ disorders, phenotypes that are used to examine the effects of the therapy, and therapeutic outcomes.
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Affiliation(s)
- Maciej Figiel
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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38
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Kamanu FK, Medvedeva YA, Schaefer U, Jankovic BR, Archer JAC, Bajic VB. Mutations and binding sites of human transcription factors. Front Genet 2012; 3:100. [PMID: 22670148 PMCID: PMC3365286 DOI: 10.3389/fgene.2012.00100] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 05/16/2012] [Indexed: 11/13/2022] Open
Abstract
Mutations in any genome may lead to phenotype characteristics that determine ability of an individual to cope with adaptation to environmental challenges. In studies of human biology, among the most interesting ones are phenotype characteristics that determine responses to drug treatments, response to infections, or predisposition to specific inherited diseases. Most of the research in this field has been focused on the studies of mutation effects on the final gene products, peptides, and their alterations. Considerably less attention was given to the mutations that may affect regulatory mechanism(s) of gene expression, although these may also affect the phenotype characteristics. In this study we make a pilot analysis of mutations observed in the regulatory regions of 24,667 human RefSeq genes. Our study reveals that out of eight studied mutation types, "insertions" are the only one that in a statistically significant manner alters predicted transcription factor binding sites (TFBSs). We also find that 25 families of TFBSs have been altered by mutations in a statistically significant manner in the promoter regions we considered. Moreover, we find that the related transcription factors are, for example, prominent in processes related to intracellular signaling; cell fate; morphogenesis of organs and epithelium; development of urogenital system, epithelium, and tube; neuron fate commitment. Our study highlights the significance of studying mutations within the genes regulatory regions and opens way for further detailed investigations on this topic, particularly on the downstream affected pathways.
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Affiliation(s)
- Frederick Kinyua Kamanu
- Computational Bioscience Research Center, King Abdullah University of Science and Technology Thuwal, Kingdom of Saudi Arabia
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39
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Ortiz AN, Osterhaus GL, Lauderdale K, Mahoney L, Fowler SC, von Hörsten S, Riess O, Johnson MA. Motor function and dopamine release measurements in transgenic Huntington's disease model rats. Brain Res 2012; 1450:148-56. [PMID: 22418060 DOI: 10.1016/j.brainres.2012.02.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 02/01/2012] [Accepted: 02/16/2012] [Indexed: 11/30/2022]
Abstract
Huntington's disease (HD) is a fatal, genetic, neurodegenerative disorder characterized by deficits in motor and cognitive function. Here, we have quantitatively characterized motor deficiencies and dopamine release dynamics in transgenic HD model rats. Behavioral analyses were conducted using a newly-developed force-sensing runway and a previously-developed force-plate actometer. Gait disturbances were readily observed in transgenic HD rats at 12 to 15months of age. Additionally, dopamine system challenge by ip injection of amphetamine also revealed that these rats were resistant to the expression of focused stereotypy compared to wild-type controls. Moreover, dopamine release, evoked by the application of single and multiple electrical stimulus pulses applied at different frequencies, and measured using fast-scan cyclic voltammetry at carbon-fiber microelectrodes, was diminished in transgenic HD rats compared to age-matched wild-type control rats. Collectively, these results underscore the potential contribution of dopamine release alterations to the expression of motor impairments in transgenic HD rats.
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Affiliation(s)
- Andrea N Ortiz
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, The University of Kansas, Lawrence, KS 66045, USA
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40
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Farrar AM, Callahan JW, Abercrombie ED. Reduced striatal acetylcholine efflux in the R6/2 mouse model of Huntington's disease: an examination of the role of altered inhibitory and excitatory mechanisms. Exp Neurol 2011; 232:119-25. [PMID: 21864528 DOI: 10.1016/j.expneurol.2011.08.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 07/25/2011] [Accepted: 08/08/2011] [Indexed: 10/17/2022]
Abstract
Huntington's disease (HD) is a genetic neurodegenerative disorder that is characterized by the progressive onset of cognitive, psychiatric, and motor symptoms. In parallel, the neuropathology of HD is characterized by progressive loss of projection neurons in cortex and striatum; striatal cholinergic interneurons are relatively spared. Nonetheless, there is evidence that striatal acetylcholine (ACh) function is altered in HD. The present study is the first to examine striatal ACh function in awake, behaving animals, using the R6/2 mouse model of HD, which is transgenic for exon 1 of the mutant huntingtin gene. Physiological levels of extracellular striatal ACh were monitored in R6/2 mice and wild type controls using in vivo microdialysis. Results indicate that spontaneous ACh release is reduced in R6/2 mice relative to controls. Intrastriatal application of the GABA(A) antagonist bicuculline methiodide (10.0 μM) significantly elevated ACh levels in both R6/2 mice and wild type controls, while overall ACh levels were reduced in the R6/2 mice compared to the wild type group. In contrast, systemic administration of the D(1) dopamine receptor partial agonist, SKF-38393 (10.0mg/kg, IP), elevated ACh levels in control animals, but not R6/2 mice. Taken together, the present results suggest that GABA-mediated inhibition of striatal ACh release is intact in R6/2 mice, further demonstrating that cholinergic interneurons are capable of increased ACh release, whereas D(1) receptor-dependent activation of excitatory inputs to striatal cholinergic interneurons is dysfunctional in R6/2 mice. Reduced levels of extracellular striatal ACh in HD may reflect abnormalities in the excitatory innervation of cholinergic interneurons, which may have implications ACh-dependent processes that are altered in HD, including corticostriatal plasticity.
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Affiliation(s)
- Andrew M Farrar
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA.
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