1
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Fischer DF, Dijkstra S, Lo K, Suijker J, Correia ACP, Naud P, Poirier M, Tessari MA, Boogaard I, Flynn G, Visser M, Lamers MBAC, McAllister G, Munoz-Sanjuan I, Macdonald D. Development of mAb-based polyglutamine-dependent and polyglutamine length-independent huntingtin quantification assays with cross-site validation. PLoS One 2022; 17:e0266812. [PMID: 35395060 PMCID: PMC8992994 DOI: 10.1371/journal.pone.0266812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/28/2022] [Indexed: 11/30/2022] Open
Abstract
Huntington's disease (HD) is caused by an expansion of the CAG trinucleotide repeat domain in the huntingtin gene that results in expression of a mutant huntingtin protein (mHTT) containing an expanded polyglutamine tract in the amino terminus. A number of therapeutic approaches that aim to reduce mHTT expression either locally in the CNS or systemically are in clinical development. We have previously described sensitive and selective assays that measure human HTT proteins either in a polyglutamine-independent (detecting both mutant expanded and non-expanded proteins) or in a polyglutamine length-dependent manner (detecting the disease-causing polyglutamine repeats) on the electrochemiluminescence Meso Scale Discovery detection platform. These original assays relied upon polyclonal antibodies. To ensure an accessible and sustainable resource for the HD field, we developed similar assays employing monoclonal antibodies. We demonstrate that these assays have equivalent sensitivity compared to our previous assays through the evaluation of cellular and animal model systems, as well as HD patient biosamples. We also demonstrate cross-site validation of these assays, allowing direct comparison of studies performed in geographically distinct laboratories.
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Affiliation(s)
- David F. Fischer
- Charles River, Chesterford Research Park, Saffron Walden, United Kingdom
| | | | | | | | | | - Patricia Naud
- Charles River, Shrewsbury, MA, United States of America
| | | | | | | | | | | | | | - George McAllister
- Charles River, Chesterford Research Park, Saffron Walden, United Kingdom
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
| | | | - Douglas Macdonald
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
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2
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Groover SE, Adegbuyiro A, Fan CK, Hodges BL, Beasley M, Taylor K, Stonebraker AR, Siriwardhana C, Legleiter J. Macromolecular crowding in solution alters huntingtin interaction and aggregation at interfaces. Colloids Surf B Biointerfaces 2021; 206:111969. [PMID: 34246856 DOI: 10.1016/j.colsurfb.2021.111969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/16/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disease caused by an extended polyglutamine (polyQ) domain within the first exon of the huntingtin protein (htt). PolyQ expansion directly invokes the formation of a heterogenous mixture of toxic htt aggregates, including fibrils and oligomers. While htt is a cytosolic protein, it also associates with numerous membranous surfaces within the cell, leading to altered organelle morphology and dysfunction. Here, the impact of macromolecular crowding on htt aggregation in bulk solution and at solid/liquid or membrane/liquid interfaces was investigated. Dextran, Ficoll, and polyethylene glycol (PEG) were used as crowding agents. In bulk solution, crowding enhanced the heterogeneity of non-fibrillar aggregate species formed in a crowder dependent manner. However, crowding agents interfered with the deposition of htt fibrils on mica, suggesting that a crowded aqueous phase influences the interaction of htt with interfaces. By use of in situ atomic force microcopy (AFM), the aggregation of htt directly at mica and bilayer interfaces was tracked. The predominate aggregates type observed to form at the mica interface was fibrillar, but oligomeric aggregates of various stabilities were also observed. Crowding in the aqueous phase suppressed deposition and formation of htt aggregates on mica. In contrast, the addition of crowders enhanced deposition of htt aggregates onto supported total brain lipid extract (TBLE) bilayers. Different crowding agents led to distinct htt aggregates on supported bilayers with unique morphological impact on bilayer integrity. Collectively, these observations point to the complexity of htt aggregation at interfaces and that crowding in the aqueous phase profoundly influences this process.
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Affiliation(s)
- Sharon E Groover
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Caleb K Fan
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Breanna L Hodges
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Katelyn Taylor
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Chathuranga Siriwardhana
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States.
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3
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Schindler F, Praedel N, Neuendorf N, Kunz S, Schnoegl S, Mason MA, Taxy BA, Bates GP, Khoshnan A, Priller J, Grimm J, Maier M, Boeddrich A, Wanker EE. Small, Seeding-Competent Huntingtin Fibrils Are Prominent Aggregate Species in Brains of zQ175 Huntington's Disease Knock-in Mice. Front Neurosci 2021; 15:682172. [PMID: 34239412 PMCID: PMC8257939 DOI: 10.3389/fnins.2021.682172] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/31/2021] [Indexed: 12/21/2022] Open
Abstract
The deposition of mutant huntingtin (mHTT) protein aggregates in neurons of patients is a pathological hallmark of Huntington’s disease (HD). Previous investigations in cell-free and cell-based disease models showed mHTT exon-1 (mHTTex1) fragments with pathogenic polyglutamine (polyQ) tracts (>40 glutamines) to self-assemble into highly stable, β-sheet-rich protein aggregates with a fibrillar morphology. HD knock-in mouse models have not been extensively studied with regard to mHTT aggregation. They endogenously produce full-length mHTT with a pathogenic polyQ tract as well as mHTTex1 fragments. Here, we demonstrate that seeding-competent, fibrillar mHTT aggregates can be readily detected in brains of zQ175 knock-in HD mice. To do this, we applied a highly sensitive FRET-based protein amplification assay that is capable of detecting seeding-competent mHTT aggregate species down to the femtomolar range. Furthermore, we show that fibrillar structures with an average length of ∼200 nm can be enriched with aggregate-specific mouse and human antibodies from zQ175 mouse brain extracts through immunoprecipitations, confirming that such structures are formed in vivo. Together these studies indicate that small, fibrillar, seeding-competent mHTT structures are prominent aggregate species in brains of zQ175 mice.
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Affiliation(s)
- Franziska Schindler
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Nicole Praedel
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Nancy Neuendorf
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Severine Kunz
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sigrid Schnoegl
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Michael A Mason
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UK Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Bridget A Taxy
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UK Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Gillian P Bates
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UK Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Ali Khoshnan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Josef Priller
- Department of Psychiatry and Psychotherapy, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Charité-Universitätsmedizin Berlin and DZNE, Berlin, Germany.,The University of Edinburgh, UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Jan Grimm
- Neurimmune AG, Schlieren, Switzerland
| | | | - Annett Boeddrich
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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4
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Yang J, Yang X. Phase Transition of Huntingtin: Factors and Pathological Relevance. Front Genet 2020; 11:754. [PMID: 32849783 PMCID: PMC7396480 DOI: 10.3389/fgene.2020.00754] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 06/24/2020] [Indexed: 12/28/2022] Open
Abstract
Formation of intracellular mutant Huntingtin (mHtt) aggregates is a hallmark of Huntington’s disease (HD). The mechanisms underlying mHtt aggregation, however, are still not fully understood. A few recent studies indicated mHtt undergoes phase transition, bringing new clues to understand how mHtt aggregates assemble. Here in this mini review, we will summarize these findings with a focus on the factors that affect mHtt phase transition. We will also discuss the possible pathological roles of mHtt phase separation in HD.
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Affiliation(s)
- Junsheng Yang
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Xiaotong Yang
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
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5
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Yang H, Yang S, Jing L, Huang L, Chen L, Zhao X, Yang W, Pan Y, Yin P, Qin ZS, Tang B, Li S, Li XJ. Truncation of mutant huntingtin in knock-in mice demonstrates exon1 huntingtin is a key pathogenic form. Nat Commun 2020; 11:2582. [PMID: 32444599 PMCID: PMC7244548 DOI: 10.1038/s41467-020-16318-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 04/21/2020] [Indexed: 12/22/2022] Open
Abstract
Polyglutamine expansion in proteins can cause selective neurodegeneration, although the mechanisms are not fully understood. In Huntington’s disease (HD), proteolytic processing generates toxic N-terminal huntingtin (HTT) fragments that preferentially kill striatal neurons. Here, using CRISPR/Cas9 to truncate full-length mutant HTT in HD140Q knock-in (KI) mice, we show that exon 1 HTT is stably present in the brain, regardless of truncation sites in full-length HTT. This N-terminal HTT leads to similar HD-like phenotypes and age-dependent HTT accumulation in the striatum in different KI mice. We find that exon 1 HTT is constantly generated but its selective accumulation in the striatum is associated with the age-dependent expression of striatum-enriched HspBP1, a chaperone inhibitory protein. Our findings suggest that tissue-specific chaperone function contributes to the selective neuropathology in HD, and highlight the therapeutic potential in blocking generation of exon 1 HTT. The mechanisms by which mutant Huntington protein Htt leads to selective neurodegeneration are not fully understood. Here, using gene editing in HD140Q knock-in mice, the authors show that exon1 Htt is a critical pathological form of the protein.
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Affiliation(s)
- Huiming Yang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, 510080, Guangzhou, China.,Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China.,Department of Neurology, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Su Yang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China
| | - Liang Jing
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Department of Emergency, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430030, Wuhan, China
| | - Luoxiu Huang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Luxiao Chen
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Xianxian Zhao
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China
| | - Weili Yang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China
| | - Yongcheng Pan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Department of Neurology & Key Laboratory of Hunan Province in Neurodegenerative Disorders, Xiangya Hospital, Central South University, Hunan, China
| | - Peng Yin
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China
| | - Zhaohui S Qin
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Beisha Tang
- Department of Neurology & Key Laboratory of Hunan Province in Neurodegenerative Disorders, Xiangya Hospital, Central South University, Hunan, China
| | - Shihua Li
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China.
| | - Xiao-Jiang Li
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, 510632, Guangzhou, China.
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6
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Morozko EL, Ochaba J, Hernandez SJ, Lau A, Sanchez I, Orellana I, Kopan L, Crapser J, Duong JH, Overman J, Yeung S, Steffan JS, Reidling J, Thompson LM. Longitudinal Biochemical Assay Analysis of Mutant Huntingtin Exon 1 Protein in R6/2 Mice. J Huntingtons Dis 2019; 7:321-335. [PMID: 30452420 DOI: 10.3233/jhd-180329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Biochemical analysis of mutant huntingtin (mHTT) aggregation species in HD mice is a common measure to track disease. A longitudinal and systematic study of how tissue processing affects detection of conformers has not yet been reported. Understanding the homeostatic flux of mHTT over time and under different processing conditions would aid in interpretation of pre-clinical assessments of disease interventions. OBJECTIVE Provide a systematic evaluation of tissue lysis methods and molecular and biochemical assays in parallel with behavioral readouts in R6/2 mice to establish a baseline for HTT exon1 protein accumulation. METHODS Established biochemical methods were used to process tissue from R6/2 mice of specific ages following behavior tasks. Aggregation states and accumulation of mHTT exon 1 protein were evaluated using multiple break and assay methods to determine potential conformational flux assay specificity in detection of mHTT species, and tissue specificity of conformers. RESULTS Detection of mHTT exon 1 protein species varied based on biochemical processing and analysis providing a baseline for subsequent studies in R6/2 mice. Insoluble, high molecular weight species of mHTT exon 1 protein increased and tracked with onset of behavioral impairments in R6/2 mice using multiple assay methods. CONCLUSIONS Conformational flux from soluble monomer to high molecular weight, insoluble species of mHTT exon 1 protein was generally consistent for multiple assay methods throughout R6/2 disease progression; however, the results support the use of multiple biochemical techniques to detect mHTT exon 1 protein species for preclinical assessments in HD mouse models expressing mHTT exon 1 protein.
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Affiliation(s)
- Eva L Morozko
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Joseph Ochaba
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA.,University of California, Irvine, Psychiatry & Human Behavior, Irvine, CA, USA
| | - Sarah J Hernandez
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Alice Lau
- University of California, Irvine, Psychiatry & Human Behavior, Irvine, CA, USA
| | - Isabella Sanchez
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Iliana Orellana
- Institute for Memory Impairment and Neurological Disorders, University of California, Irvine, CA, USA
| | - Lexi Kopan
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Joshua Crapser
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Janet H Duong
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Julia Overman
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA
| | - Silvia Yeung
- Institute for Memory Impairment and Neurological Disorders, University of California, Irvine, CA, USA
| | - Joan S Steffan
- University of California, Irvine, Psychiatry & Human Behavior, Irvine, CA, USA.,Institute for Memory Impairment and Neurological Disorders, University of California, Irvine, CA, USA
| | - Jack Reidling
- Institute for Memory Impairment and Neurological Disorders, University of California, Irvine, CA, USA
| | - Leslie M Thompson
- University of California, Irvine, Neurobiology and Behavior, Irvine, CA, USA.,University of California, Irvine, Psychiatry & Human Behavior, Irvine, CA, USA.,Institute for Memory Impairment and Neurological Disorders, University of California, Irvine, CA, USA
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7
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Soares TR, Reis SD, Pinho BR, Duchen MR, Oliveira JMA. Targeting the proteostasis network in Huntington's disease. Ageing Res Rev 2019; 49:92-103. [PMID: 30502498 PMCID: PMC6320389 DOI: 10.1016/j.arr.2018.11.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/19/2018] [Accepted: 11/26/2018] [Indexed: 12/31/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion mutation in the huntingtin protein. Expansions above 40 polyglutamine repeats are invariably fatal, following a symptomatic period characterised by choreiform movements, behavioural abnormalities, and cognitive decline. While mutant huntingtin (mHtt) is widely expressed from early life, most patients with HD present in mid-adulthood, highlighting the role of ageing in disease pathogenesis. mHtt undergoes proteolytic cleavage, misfolding, accumulation, and aggregation into inclusion bodies. The emerging model of HD pathogenesis proposes that the chronic production of misfolded mHtt overwhelms the chaperone machinery, diverting other misfolded clients to the proteasome and the autophagy pathways, ultimately leading to a global collapse of the proteostasis network. Multiple converging hypotheses also implicate ageing and its impact in the dysfunction of organelles as additional contributing factors to the collapse of proteostasis in HD. In particular, mitochondrial function is required to sustain the activity of ATP-dependent chaperones and proteolytic machinery. Recent studies elucidating mitochondria-endoplasmic reticulum interactions and uncovering a dedicated proteostasis machinery in mitochondria, suggest that mitochondria play a more active role in the maintenance of cellular proteostasis than previously thought. The enhancement of cytosolic proteostasis pathways shows promise for HD treatment, protecting cells from the detrimental effects of mHtt accumulation. In this review, we consider how mHtt and its post translational modifications interfere with protein quality control pathways, and how the pharmacological and genetic modulation of components of the proteostasis network impact disease phenotypes in cellular and in vivo HD models.
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Affiliation(s)
- Tânia R Soares
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Sara D Reis
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Brígida R Pinho
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Michael R Duchen
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK
| | - Jorge M A Oliveira
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK.
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8
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CNS repurposing - Potential new uses for old drugs: Examples of screens for Alzheimer's disease, Parkinson's disease and spasticity. Neuropharmacology 2018; 147:4-10. [PMID: 30165077 DOI: 10.1016/j.neuropharm.2018.08.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/10/2018] [Accepted: 08/23/2018] [Indexed: 12/18/2022]
Abstract
Drug repurposing is recently gaining increasing attention, not just from pharmaceutical companies but also from government agencies in an attempt to generate new medications to address increasing unmet medical needs in a cost effective and expedite manner. There are several approaches to identify novel indications for known drugs. Many are based on rational selection e.g. the known or a new mechanism of action of a drug. This review will focus rather on phenotypic or high content screening of compounds in models that are believed to be predictive of effectiveness of compounds irrespective of their mechanism of action. Three short cases studies of screens for Alzheimer's disease, Parkinson's disease and spasticity will be given as examples. This article is part of the Special Issue entitled 'Drug Repurposing: old molecules, new ways to fast track drug discovery and development for CNS disorders'.
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9
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Genetic Rodent Models of Huntington Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:29-57. [DOI: 10.1007/978-3-319-71779-1_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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10
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Adegbuyiro A, Sedighi F, Pilkington AW, Groover S, Legleiter J. Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease. Biochemistry 2017; 56:1199-1217. [PMID: 28170216 DOI: 10.1021/acs.biochem.6b00936] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several hereditary neurological and neuromuscular diseases are caused by an abnormal expansion of trinucleotide repeats. To date, there have been 10 of these trinucleotide repeat disorders associated with an expansion of the codon CAG encoding glutamine (Q). For these polyglutamine (polyQ) diseases, there is a critical threshold length of the CAG repeat required for disease, and further expansion beyond this threshold is correlated with age of onset and symptom severity. PolyQ expansion in the translated proteins promotes their self-assembly into a variety of oligomeric and fibrillar aggregate species that accumulate into the hallmark proteinaceous inclusion bodies associated with each disease. Here, we review aggregation mechanisms of proteins with expanded polyQ-tracts, structural consequences of expanded polyQ ranging from monomers to fibrillar aggregates, the impact of protein context and post-translational modifications on aggregation, and a potential role for lipid membranes in aggregation. As the pathogenic mechanisms that underlie these disorders are often classified as either a gain of toxic function or loss of normal protein function, some toxic mechanisms associated with mutant polyQ tracts will also be discussed.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University , Morgantown, West Virginia 26506, United States.,NanoSAFE, P.O. Box 6223, West Virginia University , Morgantown, West Virginia 26506, United States
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11
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Sahoo B, Arduini I, Drombosky KW, Kodali R, Sanders LH, Greenamyre JT, Wetzel R. Folding Landscape of Mutant Huntingtin Exon1: Diffusible Multimers, Oligomers and Fibrils, and No Detectable Monomer. PLoS One 2016; 11:e0155747. [PMID: 27271685 PMCID: PMC4894636 DOI: 10.1371/journal.pone.0155747] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 05/03/2016] [Indexed: 12/19/2022] Open
Abstract
Expansion of the polyglutamine (polyQ) track of the Huntingtin (HTT) protein above 36 is associated with a sharply enhanced risk of Huntington’s disease (HD). Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS) to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6–9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the reaction profile in the context of emerging cellular distress. The data provide some new candidates for the toxic species and some new reservations about more well-established candidates. Compared to other known markers of HTT toxicity, nuclear DNA damage appears to be a relatively early pathological event.
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Affiliation(s)
- Bankanidhi Sahoo
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Irene Arduini
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Kenneth W. Drombosky
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Ravindra Kodali
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Laurie H. Sanders
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - J. Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Ronald Wetzel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- * E-mail:
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12
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O'Brien R, DeGiacomo F, Holcomb J, Bonner A, Ring KL, Zhang N, Zafar K, Weiss A, Lager B, Schilling B, Gibson BW, Chen S, Kwak S, Ellerby LM. Integration-independent Transgenic Huntington Disease Fragment Mouse Models Reveal Distinct Phenotypes and Life Span in Vivo. J Biol Chem 2015; 290:19287-306. [PMID: 26025364 DOI: 10.1074/jbc.m114.623561] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Indexed: 11/06/2022] Open
Abstract
The cascade of events that lead to cognitive decline, motor deficits, and psychiatric symptoms in patients with Huntington disease (HD) is triggered by a polyglutamine expansion in the N-terminal region of the huntingtin (HTT) protein. A significant mechanism in HD is the generation of mutant HTT fragments, which are generally more toxic than the full-length HTT. The protein fragments observed in human HD tissue and mouse models of HD are formed by proteolysis or aberrant splicing of HTT. To systematically investigate the relative contribution of the various HTT protein proteolysis events observed in vivo, we generated transgenic mouse models of HD representing five distinct proteolysis fragments ending at amino acids 171, 463, 536, 552, and 586 with a polyglutamine length of 148. All lines contain a single integration at the ROSA26 locus, with expression of the fragments driven by the chicken β-actin promoter at nearly identical levels. The transgenic mice N171-Q148 and N552-Q148 display significantly accelerated phenotypes and a shortened life span when compared with N463-Q148, N536-Q148, and N586-Q148 transgenic mice. We hypothesized that the accelerated phenotype was due to altered HTT protein interactions/complexes that accumulate with age. We found evidence for altered HTT complexes in caspase-2 fragment transgenic mice (N552-Q148) and a stronger interaction with the endogenous HTT protein. These findings correlate with an altered HTT molecular complex and distinct proteins in the HTT interactome set identified by mass spectrometry. In particular, we identified HSP90AA1 (HSP86) as a potential modulator of the distinct neurotoxicity of the caspase-2 fragment mice (N552-Q148) when compared with the caspase-6 transgenic mice (N586-Q148).
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Affiliation(s)
- Robert O'Brien
- From the Buck Institute for Research on Aging, Novato, California 94945
| | | | - Jennifer Holcomb
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Akilah Bonner
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Karen L Ring
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Ningzhe Zhang
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Khan Zafar
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Andreas Weiss
- Evotec AG, Manfred Eigen Campus, Essener Bogen 7, 22419 Hamburg, Germany, and
| | - Brenda Lager
- CHDI Management/CHDI Foundation, Inc., Princeton, New Jersey 08540
| | - Birgit Schilling
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Bradford W Gibson
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Sylvia Chen
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Seung Kwak
- CHDI Management/CHDI Foundation, Inc., Princeton, New Jersey 08540
| | - Lisa M Ellerby
- From the Buck Institute for Research on Aging, Novato, California 94945,
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13
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Bates GP, Dorsey R, Gusella JF, Hayden MR, Kay C, Leavitt BR, Nance M, Ross CA, Scahill RI, Wetzel R, Wild EJ, Tabrizi SJ. Huntington disease. Nat Rev Dis Primers 2015; 1:15005. [PMID: 27188817 DOI: 10.1038/nrdp.2015.5] [Citation(s) in RCA: 924] [Impact Index Per Article: 102.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Huntington disease is devastating to patients and their families - with autosomal dominant inheritance, onset typically in the prime of adult life, progressive course, and a combination of motor, cognitive and behavioural features. The disease is caused by an expanded CAG trinucleotide repeat (of variable length) in HTT, the gene that encodes the protein huntingtin. In mutation carriers, huntingtin is produced with abnormally long polyglutamine sequences that confer toxic gains of function and predispose the protein to fragmentation, resulting in neuronal dysfunction and death. In this Primer, we review the epidemiology of Huntington disease, noting that prevalence is higher than previously thought, geographically variable and increasing. We describe the relationship between CAG repeat length and clinical phenotype, as well as the concept of genetic modifiers of the disease. We discuss normal huntingtin protein function, evidence for differential toxicity of mutant huntingtin variants, theories of huntingtin aggregation and the many different mechanisms of Huntington disease pathogenesis. We describe the genetic and clinical diagnosis of the condition, its clinical assessment and the multidisciplinary management of symptoms, given the absence of effective disease-modifying therapies. We review past and present clinical trials and therapeutic strategies under investigation, including impending trials of targeted huntingtin-lowering drugs and the progress in development of biomarkers that will support the next generation of trials. For an illustrated summary of this Primer, visit: http://go.nature.com/hPMENh.
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Affiliation(s)
- Gillian P Bates
- Department of Medical and Molecular Genetics, King's College London, London, UK
| | - Ray Dorsey
- Department of Neurology, University of Rochester Medical Center, Rochester, New York, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Martha Nance
- Struthers Parkinson's Center, Golden Valley, Minneapolis, Minnesota, USA; and Hennepin County Medical Center, Minneapolis, Minnesota, USA
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry and Departments of Neurology, Pharmacology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rachael I Scahill
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ronald Wetzel
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Edward J Wild
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Sarah J Tabrizi
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
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14
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Hoffner G, Djian P. Polyglutamine Aggregation in Huntington Disease: Does Structure Determine Toxicity? Mol Neurobiol 2014; 52:1297-1314. [PMID: 25336039 DOI: 10.1007/s12035-014-8932-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/09/2014] [Indexed: 01/14/2023]
Abstract
Huntington disease is a dominantly inherited disease of the central nervous system. The mutational expansion of polyglutamine beyond a critical length produces a toxic gain of function in huntingtin and results in neuronal death. In the course of the disease, expanded huntingtin is proteolyzed, becomes abnormally folded, and accumulates in oligomers, fibrils, and microscopic inclusions. The aggregated forms of the expanded protein are structurally diverse. Structural heterogeneity may explain why polyglutamine-containing aggregates could paradoxically be either toxic or neuroprotective. When defined, the toxic structures could then specifically be targeted by prophylactic or therapeutic drugs aimed at inhibiting polyglutamine aggregation.
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Affiliation(s)
- Guylaine Hoffner
- Laboratoire de Physiologie Cérébrale, Centre National de la Recherche Scientifique, Université Paris Descartes, 45 rue des Saints Pères, 75006, Paris, France
| | - Philippe Djian
- Laboratoire de Physiologie Cérébrale, Centre National de la Recherche Scientifique, Université Paris Descartes, 45 rue des Saints Pères, 75006, Paris, France.
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15
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Ubiquitin-activating enzyme activity contributes to differential accumulation of mutant huntingtin in brain and peripheral tissues. J Neurosci 2014; 34:8411-22. [PMID: 24948797 DOI: 10.1523/jneurosci.0775-14.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Huntington's disease (HD) belongs to a family of neurodegenerative diseases caused by misfolded proteins and shares the pathological hallmark of selective accumulation of misfolded proteins in neuronal cells. Polyglutamine expansion in the HD protein, huntingtin (Htt), causes selective neurodegeneration that is more severe in the striatum and cortex than in other brain regions, but the mechanism behind this selectivity is unknown. Here we report that in HD knock-in mice, the expression levels of mutant Htt (mHtt) are higher in brain tissues than in peripheral tissues. However, the expression of N-terminal mHtt via stereotaxic injection of viral vectors in mice also results in greater accumulation of mHtt in the striatum than in muscle. We developed an in vitro assay that revealed that extracts from the striatum and cortex promote the formation of high-molecular weight (HMW) mHtt compared with the relatively unaffected cerebellar and peripheral tissue extracts. Inhibition of ubiquitin-activating enzyme E1 (Ube1) increased the levels of HMW mHtt in the relatively unaffected tissues. Importantly, the expression levels of Ube1 are lower in brain tissues than peripheral tissues and decline in the nuclear fraction with age, which is correlated with the increased accumulation of mHtt in the brain and neuronal nuclei during aging. Our findings suggest that decreased targeting of misfolded Htt to the proteasome for degradation via Ube1 may underlie the preferential accumulation of toxic forms of mHtt in the brain and its selective neurodegeneration.
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16
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Sahoo B, Singer D, Kodali R, Zuchner T, Wetzel R. Aggregation behavior of chemically synthesized, full-length huntingtin exon1. Biochemistry 2014; 53:3897-907. [PMID: 24921664 PMCID: PMC4075985 DOI: 10.1021/bi500300c] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Repeat
length disease thresholds vary among the 10 expanded polyglutamine
(polyQ) repeat diseases, from about 20 to about 50 glutamine residues.
The unique amino acid sequences flanking the polyQ segment are thought
to contribute to these repeat length thresholds. The specific portions
of the flanking sequences that modulate polyQ properties are not always
clear, however. This ambiguity may be important in Huntington’s
disease (HD), for example, where in vitro studies
of aggregation mechanisms have led to distinctly different mechanistic
models. Most in vitro studies of the aggregation
of the huntingtin (HTT) exon1 fragment implicated in the HD mechanism
have been conducted on inexact molecules that are imprecise either
on the N-terminus (recombinantly produced peptides) or on the C-terminus
(chemically synthesized peptides). In this paper, we investigate the
aggregation properties of chemically synthesized HTT exon1 peptides
that are full-length and complete, containing both normal and expanded
polyQ repeat lengths, and compare the results directly to previously
investigated molecules containing truncated C-termini. The results
on the full-length peptides are consistent with a two-step aggregation
mechanism originally developed based on studies of the C-terminally
truncated analogues. Thus, we observe relatively rapid formation of
spherical oligomers containing from 100 to 600 HTT exon1 molecules
and intermediate formation of short protofibril-like structures containing
from 500 to 2600 molecules. In contrast to this relatively rapid assembly,
mature HTT exon1 amyloid requires about one month to dissociate in vitro, which is similar to the time required for neuronal
HTT exon1 aggregates to disappear in vivo after HTT
production is discontinued.
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Affiliation(s)
- Bankanidhi Sahoo
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15260, United States
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17
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Hoffner G, Djian P. Monomeric, oligomeric and polymeric proteins in huntington disease and other diseases of polyglutamine expansion. Brain Sci 2014; 4:91-122. [PMID: 24961702 PMCID: PMC4066239 DOI: 10.3390/brainsci4010091] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 02/06/2014] [Accepted: 02/18/2014] [Indexed: 01/03/2023] Open
Abstract
Huntington disease and other diseases of polyglutamine expansion are each caused by a different protein bearing an excessively long polyglutamine sequence and are associated with neuronal death. Although these diseases affect largely different brain regions, they all share a number of characteristics, and, therefore, are likely to possess a common mechanism. In all of the diseases, the causative protein is proteolyzed, becomes abnormally folded and accumulates in oligomers and larger aggregates. The aggregated and possibly the monomeric expanded polyglutamine are likely to play a critical role in the pathogenesis and there is increasing evidence that the secondary structure of the protein influences its toxicity. We describe here, with special attention to huntingtin, the mechanisms of polyglutamine aggregation and the modulation of aggregation by the sequences flanking the polyglutamine. We give a comprehensive picture of the characteristics of monomeric and aggregated polyglutamine, including morphology, composition, seeding ability, secondary structure, and toxicity. The structural heterogeneity of aggregated polyglutamine may explain why polyglutamine-containing aggregates could paradoxically be either toxic or neuroprotective.
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Affiliation(s)
- Guylaine Hoffner
- Génétique moléculaire et défense antivirale, Centre National de la Recherche Scientifique, Université Paris Descartes, 45 rue des Saints Pères, 75006 Paris, France.
| | - Philippe Djian
- Génétique moléculaire et défense antivirale, Centre National de la Recherche Scientifique, Université Paris Descartes, 45 rue des Saints Pères, 75006 Paris, France.
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18
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Mutant huntingtin gene-dose impacts on aggregate deposition, DARPP32 expression and neuroinflammation in HdhQ150 mice. PLoS One 2013; 8:e75108. [PMID: 24086450 PMCID: PMC3781050 DOI: 10.1371/journal.pone.0075108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 08/12/2013] [Indexed: 12/05/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant, progressive and fatal neurological disorder caused by an expansion of CAG repeats in exon-1 of the huntingtin gene. The encoded poly-glutamine stretch renders mutant huntingtin prone to aggregation. HdhQ150 mice genocopy a pathogenic repeat (∼150 CAGs) in the endogenous mouse huntingtin gene and model predominantly pre-manifest HD. Treating early is likely important to prevent or delay HD, and HdhQ150 mice may be useful to assess therapeutic strategies targeting pre-manifest HD. This requires appropriate markers and here we demonstrate, that pre-symptomatic HdhQ150 mice show several dramatic mutant huntingtin gene-dose dependent pathological changes including: (i) an increase of neuronal intra-nuclear inclusions (NIIs) in brain, (ii) an increase of extra-nuclear aggregates in dentate gyrus, (iii) a decrease of DARPP32 protein and (iv) an increase in glial markers of neuroinflammation, which curiously did not correlate with local neuronal mutant huntingtin inclusion-burden. HdhQ150 mice developed NIIs also in all retinal neuron cell-types, demonstrating that retinal NIIs are not specific to human exon-1 R6 HD mouse models. Taken together, the striking and robust mutant huntingtin gene-dose related changes in aggregate-load, DARPP32 levels and glial activation markers should greatly facilitate future testing of therapeutic strategies in the HdhQ150 HD mouse model.
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19
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The role of amyloidogenic protein oligomerization in neurodegenerative disease. J Mol Med (Berl) 2013; 91:653-64. [PMID: 23529761 DOI: 10.1007/s00109-013-1025-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 02/20/2013] [Accepted: 03/12/2013] [Indexed: 02/07/2023]
Abstract
A common pathological hallmark in many neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, is the formation of fibrillar protein aggregates referred to as amyloids. The amyloidogenic aggregates were long thought to be toxic, but mounting evidence supports the notion that a variety of amyloid aggregate intermediates to fibril formation, termed oligomers, may in fact be the primary culprit leading to neuronal dysfunction and cell death. While amyloid formation is a complex, heterogeneous process, aggregates formed by diverse, diseases-related proteins share many conformational similarities, suggesting common toxic mechanisms among these diseases. Ideally, similar therapeutic strategies may be applicable. This review focuses on the potential role of amyloidogenic oligomers in neurodegenerative disease, highlighting some promising therapeutic strategies.
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20
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Lotz GP, Weiss A. Immuno-based detection assays to quantify distinct mutant huntingtin conformations in biological samples. Methods Mol Biol 2013; 1017:163-71. [PMID: 23719915 DOI: 10.1007/978-1-62703-438-8_12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A pathological hallmark of many protein-misfolding diseases is the formation of insoluble aggregates. Quantitative methods are needed to better resolve and define the formation, aggregation, and temporal dynamics of soluble misfolded proteins in native settings. In this book chapter we describe simple and sensitive detection methods to characterize high ordered aggregates (AGERA) and subsets of distinct soluble aggregates (SEC-FRET) of mutant huntingtin protein in biological samples.
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Affiliation(s)
- Gregor P Lotz
- Novartis Institutes for BioMedical Research (NIBR), Basel, Switzerland
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