1
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Shing K, Sapp E, Boudi A, Liu S, Seeley C, Marchionini D, DiFiglia M, Kegel-Gleason KB. Early whole-body mutant huntingtin lowering averts changes in proteins and lipids important for synapse function and white matter maintenance in the LacQ140 mouse model. Neurobiol Dis 2023; 187:106313. [PMID: 37777020 PMCID: PMC10731584 DOI: 10.1016/j.nbd.2023.106313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/02/2023] Open
Abstract
Expansion of a triplet repeat tract in exon 1 of the HTT gene causes Huntington's disease (HD). The mutant HTT protein (mHTT) has numerous aberrant interactions with diverse, pleiomorphic effects. Lowering mHTT is a promising approach to treat HD, but it is unclear when lowering should be initiated, how much is necessary, and what duration should occur to achieve benefits. Furthermore, the effects of mHTT lowering on brain lipids have not been assessed. Using a mHtt-inducible mouse model, we analyzed mHtt lowering initiated at different ages and sustained for different time-periods. mHTT protein in cytoplasmic and synaptic compartments of the striatum was reduced 38-52%; however, there was minimal lowering of mHTT in nuclear and perinuclear regions where aggregates formed at 12 months of age. Total striatal lipids were reduced in 9-month-old LacQ140 mice and preserved by mHtt lowering. Subclasses important for white matter structure and function including ceramide (Cer), sphingomyelin (SM), and monogalactosyldiacylglycerol (MGDG), contributed to the reduction in total lipids. Phosphatidylinositol (PI), phosphatidylserine (PS), and bismethyl phosphatidic acid (BisMePA) were also changed in LacQ140 mice. Levels of all subclasses except ceramide were preserved by mHtt lowering. mRNA expression profiling indicated that a transcriptional mechanism contributes to changes in myelin lipids, and some but not all changes can be prevented by mHtt lowering. Our findings suggest that early and sustained reduction in mHtt can prevent changes in levels of select striatal proteins and most lipids, but a misfolded, degradation-resistant form of mHTT hampers some benefits in the long term.
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Affiliation(s)
- Kai Shing
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Ellen Sapp
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Adel Boudi
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Sophia Liu
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Connor Seeley
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | | | - Marian DiFiglia
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
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2
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Shing K, Sapp E, Boudi A, Liu S, Seeley C, Marchionini D, DiFiglia M, Kegel-Gleason KB. Early whole-body mutant huntingtin lowering averts changes in proteins and lipids important for synapse function and white matter maintenance in the LacQ140 mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525697. [PMID: 36747614 PMCID: PMC9900921 DOI: 10.1101/2023.01.26.525697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Expansion of a triplet repeat tract in exon1 of the HTT gene causes Huntington's disease (HD). The mutant HTT protein (mHTT) has numerous aberrant interactions with diverse, pleiomorphic effects. No disease modifying treatments exist but lowering mutant huntingtin (mHTT) by gene therapy is a promising approach to treat Huntington's disease (HD). It is not clear when lowering should be initiated, how much lowering is necessary and for what duration lowering should occur to achieve benefits. Furthermore, the effects of mHTT lowering on brain lipids have not been assessed. Using a mHtt-inducible mouse model we analyzed whole body mHtt lowering initiated at different ages and sustained for different time-periods. Subcellular fractionation (density gradient ultracentrifugation), protein chemistry (gel filtration, western blot, and capillary electrophoresis immunoassay), liquid chromatography and mass spectrometry of lipids, and bioinformatic approaches were used to test effects of mHTT transcriptional lowering. mHTT protein in cytoplasmic and synaptic compartments of the caudate putamen, which is most affected in HD, was reduced 38-52%. Little or no lowering of mHTT occurred in nuclear and perinuclear regions where aggregates formed at 12 months of age. mHtt transcript repression partially or fully preserved select striatal proteins (SCN4B, PDE10A). Total lipids in striatum were reduced in LacQ140 mice at 9 months and preserved by early partial mHtt lowering. The reduction in total lipids was due in part to reductions in subclasses of ceramide (Cer), sphingomyelin (SM), and monogalactosyldiacylglycerol (MGDG), which are known to be important for white matter structure and function. Lipid subclasses phosphatidylinositol (PI), phosphatidylserine (PS), and bismethyl phosphatidic acid (BisMePA) were also changed in LacQ140 mice. Levels of all subclasses other than ceramide were preserved by early mHtt lowering. Pathway enrichment analysis of RNAseq data imply a transcriptional mechanism is responsible in part for changes in myelin lipids, and some but not all changes can be rescued by mHTT lowering. Our findings suggest that early and sustained reduction in mHtt can prevent changes in levels of select striatal proteins and most lipids but a misfolded, degradation-resistant form of mHTT hampers some benefits in the long term.
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Affiliation(s)
- Kai Shing
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129
| | - Ellen Sapp
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129
| | - Adel Boudi
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129
| | - Sophia Liu
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129
| | - Connor Seeley
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129
| | | | - Marian DiFiglia
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129
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3
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Swaih AM, Breda C, Sathyasaikumar KV, Allcock N, Collier MEW, Mason RP, Feasby A, Herrera F, Outeiro TF, Schwarcz R, Repici M, Giorgini F. Kynurenine 3-Monooxygenase Interacts with Huntingtin at the Outer Mitochondrial Membrane. Biomedicines 2022; 10:2294. [PMID: 36140394 PMCID: PMC9496550 DOI: 10.3390/biomedicines10092294] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
The flavoprotein kynurenine 3-monooxygenase (KMO) is localised to the outer mitochondrial membrane and catalyses the synthesis of 3-hydroxykynurenine from L-kynurenine, a key step in the kynurenine pathway (KP) of tryptophan degradation. Perturbation of KP metabolism due to inflammation has long been associated with the pathogenesis of several neurodegenerative disorders, including Huntington's disease (HD)-which is caused by the expansion of a polyglutamine stretch in the huntingtin (HTT) protein. While HTT is primarily localised to the cytoplasm, it also associates with mitochondria, where it may physically interact with KMO. In order to test this hypothesis, we employed bimolecular fluorescence complementation (BiFC) and found that KMO physically interacts with soluble HTT exon 1 protein fragment in living cells. Notably, expansion of the disease-causing polyglutamine tract in HTT leads to the formation of proteinaceous intracellular inclusions that disrupt this interaction with KMO, markedly decreasing BiFC efficiency. Using confocal microscopy and ultrastructural analysis, we determined KMO and HTT localisation within the cell and found that the KMO-HTT interaction is localized to the outer mitochondrial membrane. These data suggest that KMO may interact with a pool of HTT at the mitochondrial membrane, highlighting a possible physiological role for mitochondrial HTT. The KMO-HTT interaction is abrogated upon polyglutamine expansion, which may indicate a heretofore unrecognized relevance in the pathogenesis of this disorder.
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Affiliation(s)
- Aisha M. Swaih
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Carlo Breda
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
- Leicester School of Allied Health Sciences, Faculty of Health and Life Sciences, De Montfort University, Leicester LE1 9BH, UK
| | - Korrapati V. Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Natalie Allcock
- Core Biotechnology Services, Adrian Building, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Mary E. W. Collier
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Robert P. Mason
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Adam Feasby
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Federico Herrera
- Cell Structure and Dynamics Laboratory, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Tiago F. Outeiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37073 Göttingen, Germany
- Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle NE2 4HH, UK
- Scientific Employee with an Honorary Contract at German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mariaelena Repici
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
- College of Health and Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Flaviano Giorgini
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
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4
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Hashimoto M, Watanabe K, Miyoshi K, Koyanagi Y, Tadano J, Miyawaki I. Multiplatform metabolomic analysis of the R6/2 mouse model of Huntington's disease. FEBS Open Bio 2021; 11:2807-2818. [PMID: 34469070 PMCID: PMC8487039 DOI: 10.1002/2211-5463.13285] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/03/2021] [Accepted: 08/31/2021] [Indexed: 11/30/2022] Open
Abstract
Huntington's disease (HD) is a progressive, neurodegenerative disease characterized by motor, cognitive, and psychiatric symptoms. To investigate the metabolic alterations that occur in HD, here we examined plasma and whole-brain metabolomic profiles of the R6/2 mouse model of HD. Plasma and brain metabolomic analyses were conducted using capillary electrophoresis-mass spectrometry (CE-MS). In addition, liquid chromatography-mass spectrometry (LC-MS) was also applied to plasma metabolomic analyses, to cover the broad range of metabolites with various physical and chemical properties. Various metabolic alterations were identified in R6/2 mice. We report for the first time the perturbation of histidine metabolism in the brain of R6/2 mice, which was signaled by decreases in neuroprotective dipeptides and histamine metabolites, indicative of neurodegeneration and an altered histaminergic system. Other differential metabolites were related to arginine metabolism and cysteine and methionine metabolism, suggesting upregulation of the urea cycle, perturbation of energy homeostasis, and an increase in oxidative stress. In addition, remarkable changes in specific lipid classes are indicative of dysregulation of lipid metabolism. These findings provide a deeper insight into the metabolic alterations that occur in HD and provide a foundation for the future development of HD therapeutics.
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Affiliation(s)
- Masayo Hashimoto
- Preclinical Research UnitSumitomo Dainippon Pharma Co., LtdOsakaJapan
| | - Kenichi Watanabe
- Preclinical Research UnitSumitomo Dainippon Pharma Co., LtdOsakaJapan
| | - Kan Miyoshi
- Pharmacology Research UnitSumitomo Dainippon Pharma Co., LtdOsakaJapan
| | - Yukako Koyanagi
- Pharmacology Research UnitSumitomo Dainippon Pharma Co., LtdOsakaJapan
| | - Jun Tadano
- Preclinical Research UnitSumitomo Dainippon Pharma Co., LtdOsakaJapan
| | - Izuru Miyawaki
- Preclinical Research UnitSumitomo Dainippon Pharma Co., LtdOsakaJapan
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5
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Hunter M, Demarais NJ, Faull RLM, Grey AC, Curtis MA. An imaging mass spectrometry atlas of lipids in the human neurologically normal and Huntington's disease caudate nucleus. J Neurochem 2021; 157:2158-2172. [PMID: 33606279 DOI: 10.1111/jnc.15325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 01/25/2021] [Accepted: 02/17/2021] [Indexed: 12/24/2022]
Abstract
Huntington's disease (HD) is a fatal disorder associated with germline trinucleotide repeat expansions in the HTT gene and characterised by striatal neurodegeneration. No efficacious interventions are available for HD, highlighting a major unmet medical need. The molecular mechanisms underlying HD are incompletely understood despite its monogenic aetiology. However, direct interactions between HTT and membrane lipids suggest that lipidomic perturbations may be implicated in the neuropathology of HD. In this study, we employed matrix-assisted laser desorption/ionisation imaging mass spectrometry (MALDI-IMS) to generate a comprehensive, unbiased and spatially resolved lipidomic atlas of the caudate nucleus (CN) in human post-mortem tissue from neurologically normal (n = 10) and HD (n = 13) subjects. Fourier transform-ion cyclotron resonance mass spectrometry and liquid chromatography-tandem mass spectrometry were used for lipid assignment. Lipidomic specialisation was observed in the grey and white matter constituents of the CN and these features were highly conserved between subjects. While the majority of lipid species were highly conserved in HD, compared to age-matched controls, CN specimens from HD cases in our cohort spanning a range of neuropathological grades showed a lower focal abundance of the neuroprotective docosahexaenoic and adrenic acids, several cardiolipins, the ganglioside GM1 and glycerophospholipids with long polyunsaturated fatty acyls. HD cases showed a higher focal abundance of several sphingomyelins and glycerophospholipids with shorter monosaturated fatty acyls. Moreover, we demonstrate that MALDI-IMS is tractable as a primary discovery modality comparing heterogeneous human brain tissue, provided that appropriate statistical approaches are adopted. Our findings support further investigation into the potential role of lipidomic aberrations in HD.
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Affiliation(s)
- Mandana Hunter
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Nicholas J Demarais
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Angus C Grey
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
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6
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Breza M, Emmanouilidou E, Leandrou E, Kartanou C, Bougea A, Panas M, Stefanis L, Karadima G, Vekrellis K, Koutsis G. Elevated Serum α-Synuclein Levels in Huntington’s Disease Patients. Neuroscience 2020; 431:34-39. [DOI: 10.1016/j.neuroscience.2020.01.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 12/19/2022]
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7
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Chaibva M, Gao X, Jain P, Campbell WA, Frey SL, Legleiter J. Sphingomyelin and GM1 Influence Huntingtin Binding to, Disruption of, and Aggregation on Lipid Membranes. ACS OMEGA 2018; 3:273-285. [PMID: 29399649 PMCID: PMC5793032 DOI: 10.1021/acsomega.7b01472] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/25/2017] [Indexed: 05/09/2023]
Abstract
Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N-terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteinaceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions between htt and lipid membranes. SM composition is altered in HD, and GM1 has been shown to have protective effects in animal models of HD. A combination of Langmuir trough monolayer techniques, vesicle permeability and binding assays, and in situ atomic force microscopy (AFM) were used to directly monitor the interaction of a model, synthetic htt peptide and a full-length htt-exon1 recombinant protein with model membranes comprised of total brain lipid extract (TBLE) and varying amounts of exogenously added SM or GM1. The addition of either SM or GM1 decreased htt insertion into the lipid monolayers. However, TBLE vesicles with an increased SM content were more susceptible to htt-induced permeabilization, whereas GM1 had no effect on permeablization. Pure TBLE bilayers and TBLE bilayers enriched with GM1 developed regions of roughened, granular morphologies upon exposure to htt-exon1, but plateau-like domains with a smoother appearance formed in bilayers enriched with SM. Oligomeric aggregates were observed on all bilayer systems regardless of induced morphology. Collectively, these observations suggest that the lipid composition and its subsequent effects on membrane material properties strongly influence htt binding and aggregation on lipid membranes.
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Affiliation(s)
- Maxmore Chaibva
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
| | - Xiang Gao
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
| | - Pranav Jain
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
| | - Warren A. Campbell
- Department
of Chemistry, Gettysburg College, 300 N. Washington Avenue, Campus Box 0393, Gettysburg, Pennsylvania 17325, United States
| | - Shelli L. Frey
- Department
of Chemistry, Gettysburg College, 300 N. Washington Avenue, Campus Box 0393, Gettysburg, Pennsylvania 17325, United States
- E-mail: . Phone: 717-337-6259 (S.L.F.)
| | - Justin Legleiter
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
- Blanchette
Rockefeller Neurosciences Institutes, West
Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States
- E-mail: . Phone: 304-293-0175 (J.L.)
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8
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Al-Ramahi I, Giridharan SSP, Chen YC, Patnaik S, Safren N, Hasegawa J, de Haro M, Wagner Gee AK, Titus SA, Jeong H, Clarke J, Krainc D, Zheng W, Irvine RF, Barmada S, Ferrer M, Southall N, Weisman LS, Botas J, Marugan JJ. Inhibition of PIP4Kγ ameliorates the pathological effects of mutant huntingtin protein. eLife 2017; 6:29123. [PMID: 29256861 PMCID: PMC5743427 DOI: 10.7554/elife.29123] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/13/2017] [Indexed: 12/15/2022] Open
Abstract
The discovery of the causative gene for Huntington’s disease (HD) has promoted numerous efforts to uncover cellular pathways that lower levels of mutant huntingtin protein (mHtt) and potentially forestall the appearance of HD-related neurological defects. Using a cell-based model of pathogenic huntingtin expression, we identified a class of compounds that protect cells through selective inhibition of a lipid kinase, PIP4Kγ. Pharmacological inhibition or knock-down of PIP4Kγ modulates the equilibrium between phosphatidylinositide (PI) species within the cell and increases basal autophagy, reducing the total amount of mHtt protein in human patient fibroblasts and aggregates in neurons. In two Drosophila models of Huntington’s disease, genetic knockdown of PIP4K ameliorated neuronal dysfunction and degeneration as assessed using motor performance and retinal degeneration assays respectively. Together, these results suggest that PIP4Kγ is a druggable target whose inhibition enhances productive autophagy and mHtt proteolysis, revealing a useful pharmacological point of intervention for the treatment of Huntington’s disease, and potentially for other neurodegenerative disorders.
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Affiliation(s)
- Ismael Al-Ramahi
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Baylor College of Medicine, Texas Medical Center, Houston, United States
| | | | - Yu-Chi Chen
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Samarjit Patnaik
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Nathaniel Safren
- Department of Neurology, University of Michigan, Ann Arbor, United States
| | - Junya Hasegawa
- Department of Cell and Developmental Biology, Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Maria de Haro
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Baylor College of Medicine, Texas Medical Center, Houston, United States
| | - Amanda K Wagner Gee
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Steven A Titus
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Hyunkyung Jeong
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Jonathan Clarke
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Dimitri Krainc
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Wei Zheng
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Robin F Irvine
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Sami Barmada
- Department of Neurology, University of Michigan, Ann Arbor, United States
| | - Marc Ferrer
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Noel Southall
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
| | - Lois S Weisman
- Department of Cell and Developmental Biology, Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Juan Botas
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Baylor College of Medicine, Texas Medical Center, Houston, United States
| | - Juan Jose Marugan
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, Rockville, United States
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9
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Masnata M, Cicchetti F. The Evidence for the Spread and Seeding Capacities of the Mutant Huntingtin Protein in in Vitro Systems and Their Therapeutic Implications. Front Neurosci 2017; 11:647. [PMID: 29234268 PMCID: PMC5712341 DOI: 10.3389/fnins.2017.00647] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/07/2017] [Indexed: 12/22/2022] Open
Abstract
Neurodegenerative disorders are not only characterized by specific patterns of cell loss but the presence and accumulation of various pathological proteins—both of which correlate with disease evolution. There is now mounting evidence to suggest that these pathological proteins present with toxic, at times prion-like, properties and can therefore seed pathology in neighboring as well remotely connected healthy neurons as they spread across the brain. What is less clear, at this stage, is how much this actually contributes to, and drives, the core pathogenic events. In this review, we present a comprehensive, up-to-date summary of the reported in vitro studies that support the spreading and seeding capacities of pathological proteins, with an emphasis on mutant huntingtin protein in the context of Huntington's disease, although in vivo work remains to be performed to validate this theory in this particular disease. We have further reviewed these findings in light of their potential implications for the development of novel therapeutic approaches.
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Affiliation(s)
- Maria Masnata
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Francesca Cicchetti
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Quebec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Quebec, QC, Canada
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10
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How SC, Hsu WT, Tseng CP, Lo CH, Chou WL, Wang SSS. Brilliant blue R dye is capable of suppressing amyloid fibril formation of lysozyme. J Biomol Struct Dyn 2017; 36:3420-3433. [DOI: 10.1080/07391102.2017.1388848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Su-Chun How
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan
| | - Wei-Tse Hsu
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan
| | - Chia-Ping Tseng
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan
| | - Chun-Hsien Lo
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan
| | - Wei-Lung Chou
- Department of Safety, Health and Environmental Engineering, Hungkuang University, Sha Lu, Taichung City 433, Taiwan
| | - Steven S.-S. Wang
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan
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11
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Mutant Huntingtin Is Secreted via a Late Endosomal/Lysosomal Unconventional Secretory Pathway. J Neurosci 2017; 37:9000-9012. [PMID: 28821645 DOI: 10.1523/jneurosci.0118-17.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 06/26/2017] [Accepted: 08/09/2017] [Indexed: 12/22/2022] Open
Abstract
Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by the expansion of a CAG triplet in the gene encoding for huntingtin (Htt). The resulting mutant protein (mHtt) with extended polyglutamine (polyQ) sequence at the N terminus leads to neuronal degeneration both in a cell-autonomous and a non-cell-autonomous manner. Recent studies identified mHtt in the extracellular environment and suggested that its spreading contributes to toxicity, but the mechanism of mHtt release from the cell of origin remains unknown. In this study, we performed a comprehensive, unbiased analysis of secretory pathways and identified an unconventional lysosomal pathway as an important mechanism for mHtt secretion in mouse neuroblastoma and striatal cell lines, as well as in primary neurons. mHtt secretion was dependent on synaptotagmin 7, a regulator of lysosomal secretion, and inhibited by chemical ablation of late endosomes/lysosomes, suggesting a lysosomal secretory pattern. mHtt was targeted preferentially to the late endosomes/lysosomes compared with wild-type Htt. Importantly, we found that late endosomal/lysosomal targeting and secretion of mHtt could be inhibited efficiently by the phosphatidylinositol 3-kinase and neutral sphingomyelinase chemical inhibitors, Ly294002 and GW4869, respectively. Together, our data suggest a lysosomal mechanism of mHtt secretion and offer potential strategies for pharmacological modulation of its neuronal secretion.SIGNIFICANCE STATEMENT This is the first study examining the mechanism of mutant huntingtin (mHTT) secretion in an unbiased manner. We found that the protein is secreted via a late endosomal/lysosomal unconventional secretory pathway. Moreover, mHtt secretion can be reduced significantly by phosphatidylinositol 3-kinase and neutral sphingomyelinase inhibitors. Understanding and manipulating the secretion of mHtt is important because of its potentially harmful propagation in the brain.
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12
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Vodicka P, Mo S, Tousley A, Green KM, Sapp E, Iuliano M, Sadri-Vakili G, Shaffer SA, Aronin N, DiFiglia M, Kegel-Gleason KB. Mass Spectrometry Analysis of Wild-Type and Knock-in Q140/Q140 Huntington's Disease Mouse Brains Reveals Changes in Glycerophospholipids Including Alterations in Phosphatidic Acid and Lyso-Phosphatidic Acid. J Huntingtons Dis 2016; 4:187-201. [PMID: 26397899 DOI: 10.3233/jhd-150149] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Huntington's disease (HD) is a neurodegenerative disease caused by a CAG expansion in the HD gene, which encodes the protein Huntingtin. Huntingtin associates with membranes and can interact directly with glycerophospholipids in membranes. OBJECTIVE We analyzed glycerophospholipid profiles from brains of 11 month old wild-type (WT) and Q140/Q140 HD knock-in mice to assess potential changes in glycerophospholipid metabolism. METHODS Polar lipids from cerebellum, cortex, and striatum were extracted and analyzed by liquid chromatography and negative ion electrospray tandem mass spectrometry analysis (LC-MS/MS). Gene products involved in polar lipid metabolism were studied using western blotting, immuno-electron microscopy and qPCR. RESULTS Significant changes in numerous species of glycerophosphate (phosphatidic acid, PA) were found in striatum, cerebellum and cortex from Q140/Q140 HD mice compared to WT mice at 11 months. Changes in specific species could also be detected for other glycerophospholipids. Increases in species of lyso-PA (LPA) were measured in striatum of Q140/Q140 HD mice compared to WT. Protein levels for c-terminal binding protein 1 (CtBP1), a regulator of PA biosynthesis, were reduced in striatal synaptosomes from HD mice compared to wild-type at 6 and 12 months. Immunoreactivity for CtBP1 was detected on membranes of synaptic vesicles in striatal axon terminals in the globus pallidus. CONCLUSIONS These novel results identify a potential site of molecular pathology caused by mutant Huntingtin that may impart early changes in HD.
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Affiliation(s)
- Petr Vodicka
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Shunyan Mo
- Proteomics and Mass Spectrometry Facility and Department of Biochemistry and Molecular Pharmacology, UMASS Medical School, Worcester, MA, USA
| | - Adelaide Tousley
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Karin M Green
- Proteomics and Mass Spectrometry Facility and Department of Biochemistry and Molecular Pharmacology, UMASS Medical School, Worcester, MA, USA
| | - Ellen Sapp
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Maria Iuliano
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | | | - Scott A Shaffer
- Proteomics and Mass Spectrometry Facility and Department of Biochemistry and Molecular Pharmacology, UMASS Medical School, Worcester, MA, USA
| | - Neil Aronin
- Departments of Medicine and Cell and Developmental Biology, UMASS Medical School, Worcester, MA, USA
| | - Marian DiFiglia
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
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13
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Gao X, Campbell WA, Chaibva M, Jain P, Leslie AE, Frey SL, Legleiter J. Cholesterol Modifies Huntingtin Binding to, Disruption of, and Aggregation on Lipid Membranes. Biochemistry 2015; 55:92-102. [PMID: 26652744 DOI: 10.1021/acs.biochem.5b00900] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disease caused by abnormally long CAG-repeats in the huntingtin gene that encode an expanded polyglutamine (polyQ) domain near the N-terminus of the huntingtin (htt) protein. Expanded polyQ domains are directly correlated to disease-related htt aggregation. Htt is found highly associated with a variety of cellular and subcellular membranes that are predominantly comprised of lipids. Since cholesterol homeostasis is altered in HD, we investigated how varying cholesterol content modifies the interactions between htt and lipid membranes. A combination of Langmuir trough monolayer techniques, vesicle permeability and binding assays, and in situ atomic force microscopy were used to directly monitor the interaction of a model, synthetic htt peptide and a full-length htt-exon1 recombinant protein with model membranes comprised of total brain lipid extract (TBLE) and varying amounts of exogenously added cholesterol. As the cholesterol content of the membrane increased, the extent of htt insertion decreased. Vesicles containing extra cholesterol were resistant to htt-induced permeabilization. Morphological and mechanical changes in the bilayer associated with exposure to htt were also drastically altered by the presence of cholesterol. Disrupted regions of pure TBLE bilayers were grainy in appearance and associated with a large number of globular aggregates. In contrast, morphological changes induced by htt in bilayers enriched in cholesterol were plateau-like with a smooth appearance. Collectively, these observations suggest that the presence and amount of cholesterol in lipid membranes play a critical role in htt binding and aggregation on lipid membranes.
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Affiliation(s)
- Xiang Gao
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26505, United States
| | - Warren A Campbell
- Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania 17325, United States
| | - Maxmore Chaibva
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26505, United States
| | - Pranav Jain
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26505, United States
| | - Ashley E Leslie
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26505, United States
| | - Shelli L Frey
- Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania 17325, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26505, United States.,NanoSAFE, P.O. Box 6223, West Virginia University, Morgantown, West Virginia 26506, United States.,The Center for Neurosciences, West Virginia University, Morgantown, West Virginia 26505, United States
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14
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Aguzzi A, Lakkaraju AKK. Cell Biology of Prions and Prionoids: A Status Report. Trends Cell Biol 2015; 26:40-51. [PMID: 26455408 DOI: 10.1016/j.tcb.2015.08.007] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/08/2015] [Accepted: 08/24/2015] [Indexed: 11/18/2022]
Abstract
The coalescence of proteins into highly ordered aggregates is a hallmark of protein misfolding disorders (PMDs), which, when affecting the central nervous system, lead to progressive neurodegeneration. Although the chemical identity and the topology of each culprit protein are unique, the principles governing aggregation and propagation are strikingly stereotypical. It is now clear that such protein aggregates can spread from cell to cell and eventually affect entire organ systems - similarly to prion diseases. However, because most aggregates are not found to transmit between individuals, they are not infectious sensu strictiori. Therefore, they are not identical to prions and we prefer to define them as 'prionoids'. Here we review recent advances in understanding the toxicity of protein aggregation affecting the brain.
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Affiliation(s)
- Adriano Aguzzi
- Institute of Neuropathology, University of Zürich, CH-8091 Zürich, Switzerland.
| | - Asvin K K Lakkaraju
- Institute of Neuropathology, University of Zürich, CH-8091 Zürich, Switzerland.
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15
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Sisakhtnezhad S, Khosravi L. Emerging physiological and pathological implications of tunneling nanotubes formation between cells. Eur J Cell Biol 2015; 94:429-43. [PMID: 26164368 DOI: 10.1016/j.ejcb.2015.06.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 06/20/2015] [Accepted: 06/23/2015] [Indexed: 12/21/2022] Open
Abstract
Cell-to-cell communication is a critical requirement to coordinate behaviors of the cells in a community and thereby achieve tissue homeostasis and conservation of the multicellular organisms. Tunneling nanotubes (TNTs), as a cell-to-cell communication over long distance, allow for bi- or uni-directional transfer of cellular components between cells. Identification of inducing agents and the cell and molecular mechanism underling the formation of TNTs and their structural and functional features may lead to finding new important roles for these intercellular bridges in vivo and in vitro. During the last decade, research has shown TNTs have different structural and functional properties, varying between and within cell systems. In this review, we will focus on TNTs and their cell and molecular mechanism of formation. Moreover, the latest findings into their functional roles in physiological and pathological processes, such as signal transduction, micro and nano-particles delivery, immune responses, embryogenesis, cellular reprogramming, apoptosis, cancer, and neurodegenerative diseases initiation and progression and pathogens transfer, will be discussed.
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Affiliation(s)
| | - Leila Khosravi
- Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran
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16
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Rescue of homeostatic regulation of striatal excitability and locomotor activity in a mouse model of Huntington's disease. Proc Natl Acad Sci U S A 2015; 112:2239-44. [PMID: 25646456 DOI: 10.1073/pnas.1405748112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We describe a fast activity-dependent homeostatic regulation of intrinsic excitability of identified neurons in mouse dorsal striatum, the striatal output neurons. It can be induced by brief bursts of activity, is expressed on a time scale of seconds, limits repetitive firing, and can convert regular firing patterns to irregular ones. We show it is due to progressive recruitment of the KCNQ2/3 channels that generate the M current. This homeostatic mechanism is significantly reduced in striatal output neurons of the R6/2 transgenic mouse model of Huntington's disease, at an age when the neurons are hyperactive in vivo and the mice begin to exhibit locomotor impairment. Furthermore, it can be rescued by bath perfusion with retigabine, a KCNQ channel activator, and chronic treatment improves locomotor performance. Thus, M-current dysfunction may contribute to the hyperactivity and network dysregulation characteristic of this neurodegenerative disease, and KCNQ2/3 channel regulation may be a target for therapeutic intervention.
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17
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Chaibva M, Burke KA, Legleiter J. Curvature enhances binding and aggregation of huntingtin at lipid membranes. Biochemistry 2014; 53:2355-65. [PMID: 24670006 DOI: 10.1021/bi401619q] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Huntington disease (HD) is a genetic neurodegenerative disease caused by an expanded polyglutamine (polyQ) domain in the first exon of the huntingtin (Htt) protein, facilitating its aggregation. Htt interacts with a variety of membraneous structures within the cell, and the first 17 amino acids (Nt17) of Htt directly flanking the polyQ domain comprise an amphiphathic α-helix (AH) lipid-binding domain. AHs are also known to detect membrane curvature. To determine if Htt exon 1 preferentially binds curved membranes, in situ atomic force microscopy (AFM) studies were performed. Supported lipid bilayers are commonly used as model membranes for AFM studies of protein aggregation. However, these supported bilayers usually lack curvature. By forming a bilayer on top of silica nanobeads (50 ± 10 nm) deposited on a silicon substrate, model supported lipid bilayers with flat and curved regions were developed for AFM studies. The presence of the bilayer over the beads was validated by continual imaging of the formation of the bilayer, height measurements, and spatially resolved mechanical measurements of the resulting bilayer using scanning probe acceleration microscopy. Interpretation of this data was facilitated by numerical simulations of the entire imaging process. The curved supported bilayers associated with the beads were found to be more compliant than flat supported bilayers, consistent with the altered packing density of lipids caused by the induced curvature. This model bilayer system was exposed to a synthetic truncated Htt exon 1 peptide (Nt17Q35P10KK), and this peptide preferentially accumulated on curved membranes, consistent with the ability of AHs to sense membrane curvature.
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Affiliation(s)
- Maxmore Chaibva
- The C. Eugene Bennett Department of Chemistry, West Virginia University , Morgantown, West Virginia 26505, United States
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18
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Côté S, Wei G, Mousseau N. Atomistic mechanisms of huntingtin N-terminal fragment insertion on a phospholipid bilayer revealed by molecular dynamics simulations. Proteins 2014; 82:1409-27. [PMID: 24415136 DOI: 10.1002/prot.24509] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/27/2013] [Accepted: 01/06/2014] [Indexed: 01/14/2023]
Abstract
The huntingtin protein is characterized by a segment of consecutive glutamines (Q(N)) that is responsible for its fibrillation. As with other amyloid proteins, misfolding of huntingtin is related to Huntington's disease through pathways that can involve interactions with phospholipid membranes. Experimental results suggest that the N-terminal 17-amino-acid sequence (htt(NT)) positioned just before the Q(N) region is important for the binding of huntingtin to membranes. Through all-atom explicit solvent molecular dynamics simulations, we unveil the structure and dynamics of the htt(NT)Q(N) fragment on a phospholipid membrane at the atomic level. We observe that the insertion dynamics of this peptide can be described by four main steps-approach, reorganization, anchoring, and insertion-that are very diverse at the atomic level. On the membrane, the htt(NT) peptide forms a stable α-helix essentially parallel to the membrane with its nonpolar side-chains-mainly Leu-4, Leu-7, Phe-11 and Leu-14-positioned in the hydrophobic core of the membrane. Salt-bridges involving Glu-5, Glu-12, Lys-6, and Lys-15, as well as hydrogen bonds involving Thr-3 and Ser-13 with the phospholipids also stabilize the structure and orientation of the htt(NT) peptide. These observations do not significantly change upon adding the Q(N) region whose role is rather to provide, through its hydrogen bonds with the phospholipids' head group, a stable scaffold facilitating the partitioning of the htt(NT) region in the membrane. Moreover, by staying accessible to the solvent, the amyloidogenic Q(N) region could also play a key role for the oligomerization of htt(NT)Q(N) on phospholipid membranes.
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Affiliation(s)
- Sébastien Côté
- Département de Physique and Groupe de recherche sur les protéines membranaires (GEPROM), Université de Montréal, Montréal (Québec), Canada
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19
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Ansaloni A, Wang ZM, Jeong JS, Ruggeri FS, Dietler G, Lashuel HA. One-Pot Semisynthesis of Exon 1 of the Huntingtin Protein: New Tools for Elucidating the Role of Posttranslational Modifications in the Pathogenesis of Huntington’s Disease. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201307510] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Ansaloni A, Wang ZM, Jeong JS, Ruggeri FS, Dietler G, Lashuel HA. One-Pot Semisynthesis of Exon 1 of the Huntingtin Protein: New Tools for Elucidating the Role of Posttranslational Modifications in the Pathogenesis of Huntington’s Disease. Angew Chem Int Ed Engl 2014; 53:1928-33. [DOI: 10.1002/anie.201307510] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/27/2013] [Indexed: 11/09/2022]
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21
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Nagarajan A, Jawahery S, Matysiak S. The effects of flanking sequences in the interaction of polyglutamine peptides with a membrane bilayer. J Phys Chem B 2014; 118:6368-79. [PMID: 24354677 DOI: 10.1021/jp407900c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Huntington's disease (HD) is caused by the presence of an extended polyglutamine (polyQ) region at the N-terminus of the huntingtin (htt) protein. The presence of flanking sequences adjacent to the polyQ region has been reported to modulate the effects of potentially toxic protein-membrane interactions. In this study, we consider four peptide systems with various combinations of flanking sequences (KKQ35KK, KKQ35P11KK, N17Q35KK, N17Q35P11KK) and use atomistic molecular dynamics simulations to study the interactions with a DOPC lipid bilayer. We observe significant membrane thinning, disorderliness of lipid molecules, and compensation effects between the top and the bottom leaflets of the bilayer depending on the presence of particular flanking sequences. Overall, we find that the presence of the N-17 flanking sequence is crucial for membrane interactions. Polyproline decreases the interaction with the membrane in the absence of N-17, but enhances it when present along N-17.
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Affiliation(s)
- Anu Nagarajan
- Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States
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22
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Muratore M. Raman spectroscopy and partial least squares analysis in discrimination of peripheral cells affected by Huntington's disease. Anal Chim Acta 2013; 793:1-10. [DOI: 10.1016/j.aca.2013.06.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/07/2013] [Accepted: 06/13/2013] [Indexed: 10/26/2022]
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23
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Costanzo M, Abounit S, Marzo L, Danckaert A, Chamoun Z, Roux P, Zurzolo C. Transfer of polyglutamine aggregates in neuronal cells occurs in tunneling nanotubes. J Cell Sci 2013; 126:3678-85. [PMID: 23781027 DOI: 10.1242/jcs.126086] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disease caused by CAG expansion in the huntingtin gene, which adds a homopolymeric tract of polyglutamine (polyQ) to the encoded protein leading to the formation of toxic aggregates. Despite rapidly accumulating evidences supporting a role for intercellular transmission of protein aggregates, little is known about whether and how huntingtin (Htt) misfolding progresses through the brain. It has been recently reported that synthetic polyQ peptides and recombinant fragments of mutant Htt are readily internalized in cell cultures and able to seed polymerization of a reporter wild-type Htt. However, there is no direct evidence of aggregate transfer between cells and the mechanism has not been explored. By expressing recombinant fragments of mutant Htt in neuronal cells and in primary neurons, we found that aggregated fragments formed within one cell spontaneously transfer to neighbors in cell culture. We demonstrate that the intercellular spreading of the aggregates requires cell-cell contact and does not occur upon aggregate secretion. Interestingly, we found that the expression of mutant, but not wild-type Htt fragments, increases the number of tunneling nanotubes, which in turn provide an efficient mechanism of transfer.
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Affiliation(s)
- Maddalena Costanzo
- Institut Pasteur, Unité de traffic membranaire et pathogenèse, 28 rue du Docteur Roux 75724 Paris, Cedex 15, France
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24
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Burke KA, Hensal KM, Umbaugh CS, Chaibva M, Legleiter J. Huntingtin disrupts lipid bilayers in a polyQ-length dependent manner. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1953-61. [PMID: 23643759 DOI: 10.1016/j.bbamem.2013.04.025] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 01/08/2023]
Abstract
Huntington's Disease (HD) is a neurodegenerative disorder that is defined by the accumulation of nanoscale aggregates comprised of the huntingtin (htt) protein. Aggregation is directly caused by an expanded polyglutamine (polyQ) domain in htt, leading to a diverse population of aggregate species, such as oligomers, fibrils, and annular aggregates. Furthermore, the length of this polyQ domain is directly related to onset and severity of disease. The first 17 N-terminal amino acids of htt have been shown to further modulate aggregation. Additionally, these 17 amino acids appear to have lipid binding properties as htt interacts with a variety of membrane-containing structures present in cells, such as organelles, and interactions with these membrane surfaces may further modulate htt aggregation. To investigate the interaction between htt exon1 and lipid bilayers, in situ atomic force microscopy (AFM) was used to directly monitor the aggregation of htt exon1 constructs with varying Q-lengths (35Q, 46Q, 51Q, and myc-53Q) on supported lipid membranes comprised of total brain lipid extract. The exon1 fragments accumulated on the lipid membranes, causing disruption of the membrane, in a polyQ dependent manner. Furthermore, the addition of an N-terminal myc-tag to the htt exon1 fragments impeded the interaction of htt with the bilayer.
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Affiliation(s)
- Kathleen A Burke
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26505, USA
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25
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The cell biology of prion-like spread of protein aggregates: mechanisms and implication in neurodegeneration. Biochem J 2013; 452:1-17. [DOI: 10.1042/bj20121898] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The misfolding and aggregation of specific proteins is a common hallmark of many neurodegenerative disorders, including highly prevalent illnesses such as Alzheimer's and Parkinson's diseases, as well as rarer disorders such as Huntington's and prion diseases. Among these, only prion diseases are ‘infectious’. By seeding misfolding of the PrPC (normal conformer prion protein) into PrPSc (abnormal disease-specific conformation of prion protein), prions spread from the periphery of the body to the central nervous system and can also be transmitted between individuals of the same or different species. However, recent exciting data suggest that the transmissibility of misfolded proteins within the brain is a property that goes way beyond the rare prion diseases. Evidence indicates that non-prion aggregates [tau, α-syn (α-synuclein), Aβ (amyloid-β) and Htt (huntingtin) aggregates] can also move between cells and seed the misfolding of their normal conformers. These findings have enormous implications. On the one hand they question the therapeutical use of transplants, and on the other they indicate that it may be possible to bring these diseases to an early arrest by preventing cell-to-cell transmission. To better understand the prion-like spread of these protein aggregates it is essential to identify the underlying cellular and molecular factors. In the present review we analyse and discuss the evidence supporting prion-like spreading of amyloidogenic proteins, especially focusing on the cellular and molecular mechanisms and their significance.
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26
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Vachharajani SN, Chaudhary RK, Prasad S, Roy I. Length of polyglutamine tract affects secondary and tertiary structures of huntingtin protein. Int J Biol Macromol 2012; 51:920-5. [PMID: 22835760 DOI: 10.1016/j.ijbiomac.2012.07.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 11/19/2022]
Abstract
The role of polyglutamine (polyQ) tract on protein stability and disease pathology remains ambiguous. We monitored the unfolding/refolding patterns of huntingtin proteins with varying polyQ lengths. In the presence of urea, minor differences in unfolding and refolding efficiencies were observed. However, in the presence of guanidinium hydrochloride, the protein with a longer polyQ stretch was able to regain its secondary but not tertiary structure on step-wise removal of denaturant. Thus, in case of Huntington's disease, the higher aggregation propensity of the mutant protein is likely to be due to the lower stability of the protein due to elongated polyQ tract.
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Affiliation(s)
- Shivang N Vachharajani
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
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27
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Marzo L, Gousset K, Zurzolo C. Multifaceted roles of tunneling nanotubes in intercellular communication. Front Physiol 2012; 3:72. [PMID: 22514537 PMCID: PMC3322526 DOI: 10.3389/fphys.2012.00072] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/13/2012] [Indexed: 01/10/2023] Open
Abstract
Cell-to-cell communication and exchange of materials are vital processes in multicellular organisms during cell development, cell repair, and cell survival. In neuronal and immunological cells, intercellular transmission between neighboring cells occurs via different complex junctions or synapses. Recently, long distance intercellular connections in mammalian cells called tunneling nanotubes (TNTs) have been described. These structures have been found in numerous cell types and shown to transfer signals and cytosolic materials between distant cells, suggesting that they might play a prominent role in intercellular trafficking. However, these cellular connections are very heterogeneous in both structure and function, giving rise to more questions than answers as to their nature and role as intercellular conduits. To better understand and characterize the functions of TNTs, we have highlighted here the latest discoveries regarding the formation, structure, and role of TNTs in cell-to-cell spreading of various signals and materials. We first gathered information regarding their formation with an emphasis on the triggering mechanisms observed, such as stress and potentially important proteins and/or signaling pathways. We then describe the various types of transfer mechanisms, in relation to signals and cargoes that have been shown recently to take advantage of these structures for intercellular transfer. Because a number of pathogens were shown to use these membrane bridges to spread between cells we also draw attention to specific studies that point toward a role for TNTs in pathogen spreading. In particular we discuss the possible role that TNTs might play in prion spreading, and speculate on their role in neurological diseases in general.
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Affiliation(s)
- Ludovica Marzo
- Unité de traffic membranaire et pathogenèse, Institut PasteurParis, France
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università Federico IINapoli, Italy
| | - Karine Gousset
- Unité de traffic membranaire et pathogenèse, Institut PasteurParis, France
| | - Chiara Zurzolo
- Unité de traffic membranaire et pathogenèse, Institut PasteurParis, France
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università Federico IINapoli, Italy
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28
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Toxic effects of expanded ataxin-1 involve mechanical instability of the nuclear membrane. Biochim Biophys Acta Mol Basis Dis 2012; 1822:906-17. [PMID: 22330095 DOI: 10.1016/j.bbadis.2012.01.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 01/26/2012] [Accepted: 01/30/2012] [Indexed: 01/01/2023]
Abstract
Ataxin 1 (ATXN1) is the protein involved in spinocerebellar ataxia type 1, one of nine dominantly inherited neurodegenerative diseases triggered by polyglutamine expansion. One of the isolated polyglutamine tracts properties is to interact with lipid bilayers. Here we used a multidisciplinary approach to test whether one of the mechanisms responsible for neuronal degeneration involves the destabilization of the nuclear membrane. We thus analyzed the interaction between ATXN1 and lipid membranes, both on cellular models and on artificial lipid bilayers, comparing pathological expanded polyglutamine and histidine interrupted non-harmful polyglutamine tracts of the same length. The toxicity of the different constructs was tested in transiently transfected COS1 cells. Cells expressing pathological ATXN1 presented a significantly higher frequency of anomalous nuclei with respect to those expressing non-harmful ATXN1. Immunofluorescence and electron microscopy showed severe damage in the nuclear membrane of cells expressing the pathological protein. Atomic force microscopy on artificial membranes containing interrupted and non-interrupted partial ATXN1 peptides revealed a different arrangement of the peptides within the lipid bilayer. Force-distance measurements indicated that membrane fragility increases with the lengthening of the uninterrupted glutamine. Transmembrane electrical measurements were performed on artificial bilayers and on the inner nuclear membrane of ATXN1 full length transfected cells. Both artificial lipid bilayers and cellular models demonstrated the dynamic appearance of ionic pathways. Uninterrupted polyglutamines showed not only a larger ionic flow, but also an increase in the single event conductance. Collectively, our results suggest that expanded ATXN1 may induce unregulated ionic pathways in the nuclear membrane, causing severe damage to the cell.
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29
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Polling S, Hill AF, Hatters DM. Polyglutamine aggregation in Huntington and related diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 769:125-40. [PMID: 23560308 DOI: 10.1007/978-1-4614-5434-2_8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Polyglutamine (polyQ)-expansions in different proteins cause nine neurodegenerative diseases. While polyQ aggregation is a key pathological hallmark of these diseases, how aggregation relates to pathogenesis remains contentious. In this chapter, we review what is known about the aggregation process and how cells respond and interact with the polyQ-expanded proteins. We cover detailed biophysical and structural studies to uncover the intrinsic features of polyQ aggregates and concomitant effects in the cellular environment. We also examine the functional consequences ofpolyQ aggregation and how cells may attempt to intervene and guide the aggregation process.
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Affiliation(s)
- Saskia Polling
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Victoria, Australia
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Assessing mutant huntingtin fragment and polyglutamine aggregation by atomic force microscopy. Methods 2010; 53:275-84. [PMID: 21187152 DOI: 10.1016/j.ymeth.2010.12.028] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 12/18/2010] [Accepted: 12/18/2010] [Indexed: 01/01/2023] Open
Abstract
Huntington disease (HD), a neurodegenerative disorder, is caused by an expansion of more than 35-40 polyglutamine (polyQ) repeats located near the N-terminus of the huntingtin (htt) protein. The expansion of the polyQ domain results in the ordered assembly of htt fragments into fibrillar aggregates that are the main constituents of inclusion bodies, which are a hallmark of the disease. This paper describes protocols for studying the aggregation of mutant htt fragments and synthetic polyQ peptides with atomic force microscopy (AFM). Ex situ AFM is used to characterize aggregate formation in protein incubation as a function of time. Methods to quickly and unambiguously distinguish specific aggregate species from complex, heterogeneous aggregation reactions based on simple morphological features are presented. Finally, the application of time lapse atomic force microscopy in solution is presented for studying synthetic model polyQ peptides, which allows for tracking the formation and fate of individual aggregates on surfaces over time. This ability allows for dynamic studies of the aggregation process and direct observation of the interplay between different types of aggregates.
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Kegel KB, Sapp E, Alexander J, Reeves P, Bleckmann D, Sobin L, Masso N, Valencia A, Jeong H, Krainc D, Palacino J, Curtis D, Kuhn R, Betschart C, Sena-Esteves M, Aronin N, Paganetti P, Difiglia M. Huntingtin cleavage product A forms in neurons and is reduced by gamma-secretase inhibitors. Mol Neurodegener 2010; 5:58. [PMID: 21156064 PMCID: PMC3018386 DOI: 10.1186/1750-1326-5-58] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 12/14/2010] [Indexed: 12/19/2022] Open
Abstract
Background The mutation in Huntington's disease is a polyglutamine expansion near the N-terminus of huntingtin. Huntingtin expressed in immortalized neurons is cleaved near the N-terminus to form N-terminal polypeptides known as cleavage products A and B (cpA and cpB). CpA and cpB with polyglutamine expansion form inclusions in the nucleus and cytoplasm, respectively. The formation of cpA and cpB in primary neurons has not been established and the proteases involved in the formation of these fragments are unknown. Results Delivery of htt cDNA into the mouse striatum using adeno-associated virus or into primary cortical neurons using lentivirus generated cpA and cpB, indicating that neurons in brain and in vitro can form these fragments. A screen of small molecule protease inhibitors introduced to clonal striatal X57 cells and HeLa cells identified compounds that reduced levels of cpA and are inhibitors of the aspartyl proteases cathepsin D and cathepsin E. The most effective compound, P1-N031, is a transition state mimetic for aspartyl proteases. By western blot analysis, cathepsin D was easily detected in clonal striatal X57 cells, mouse brain and primary neurons, whereas cathepsin E was only detectible in clonal striatal X57 cells. In primary neurons, levels of cleavage product A were not changed by the same compounds that were effective in clonal striatal cells or by mRNA silencing to partially reduce levels of cathepsin D. Instead, treating primary neurons with compounds that are known to inhibit gamma secretase activity either indirectly (Imatinib mesylate, Gleevec) or selectively (LY-411,575 or DAPT) reduced levels of cpA. LY-411,575 or DAPT also increased survival of primary neurons expressing endogenous full-length mutant huntingtin. Conclusion We show that cpA and cpB are produced from a larger huntingtin fragment in vivo in mouse brain and in primary neuron cultures. The aspartyl protease involved in forming cpA has cathepsin-D like properties in immortalized neurons and gamma secretase-like properties in primary neurons, suggesting that cell type may be a critical factor that specifies the aspartyl protease responsible for cpA. Since gamma secretase inhibitors were also protective in primary neurons, further study of the role of gamma-secretase activity in HD neurons is justified.
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Affiliation(s)
- Kimberly B Kegel
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
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Hands SL, Wyttenbach A. Neurotoxic protein oligomerisation associated with polyglutamine diseases. Acta Neuropathol 2010; 120:419-37. [PMID: 20514488 DOI: 10.1007/s00401-010-0703-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 05/20/2010] [Accepted: 05/23/2010] [Indexed: 02/07/2023]
Abstract
Polyglutamine (polyQ) diseases are associated with a CAG/polyQ expansion mutation in unrelated proteins. Upon elongation of the glutamine tract, disease proteins aggregate within cells, mainly in the central nervous system (CNS) and this aggregation process is associated with neurotoxicity. However, it remains unclear to what extent and how this aggregation causes neuronal dysfunction in the CNS. Aiming at preventing neuronal dysfunction, it will be crucial to determine the links between aggregation and cellular dysfunction, understand the folding pathway of polyQ proteins and discover the relative neurotoxicity of polyQ protein species formed along the aggregation pathway. Here, we review what is known about conformations of polyQ peptides and proteins in their monomeric state from experimental and modelling data, how conformational changes of polyQ proteins relate to their oligomerisation and morphology of aggregates and which cellular function are impaired by oligomers, in vitro and in vivo. We also summarise the key modulatory cellular mechanisms and co-factors, which could affect the folding pathway and kinetics of polyQ aggregation. Although many studies have investigated the relationship between polyQ aggregation and toxicity, these have mainly focussed on investigating changes in the formation of the classical hallmark of polyQ diseases, i.e. microscopically visible inclusion bodies. However, recent studies in which oligomeric species have been considered start to shed light on the identity of neurotoxic oligomeric species. Initial evidence suggests that conformational changes induced by polyQ expansions and their surrounding sequence lead to the formation of particular oligomeric intermediates that may differentially affect neurotoxicity.
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Affiliation(s)
- Sarah L Hands
- Southampton Neuroscience Group, School of Biological Sciences, University of Southampton, Southampton SO16 7PX, UK
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Miller JP, Holcomb J, Al-Ramahi I, de Haro M, Gafni J, Zhang N, Kim E, Sanhueza M, Torcassi C, Kwak S, Botas J, Hughes RE, Ellerby LM. Matrix metalloproteinases are modifiers of huntingtin proteolysis and toxicity in Huntington's disease. Neuron 2010; 67:199-212. [PMID: 20670829 DOI: 10.1016/j.neuron.2010.06.021] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2010] [Indexed: 01/27/2023]
Abstract
Proteolytic cleavage of huntingtin (Htt) is known to be a key event in the pathogenesis of Huntington's disease (HD). Our understanding of proteolytic processing of Htt has thus far focused on the protease families-caspases and calpains. Identifying critical proteases involved in Htt proteolysis and toxicity using an unbiased approach has not been reported. To accomplish this, we designed a high-throughput western blot-based screen to examine the generation of the smallest N-terminal polyglutamine-containing Htt fragment. We screened 514 siRNAs targeting the repertoire of human protease genes. This screen identified 11 proteases that, when inhibited, reduced Htt fragment accumulation. Three of these belonged to the matrix metalloproteinase (MMP) family. One family member, MMP-10, directly cleaves Htt and prevents cell death when knocked down in striatal Hdh(111Q/111Q) cells. Correspondingly, MMPs are activated in HD mouse models, and loss of function of Drosophila homologs of MMPs suppresses Htt-induced neuronal dysfunction in vivo.
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Affiliation(s)
- John P Miller
- Buck Institute for Age Research, Novato, CA 94945, USA
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Abstract
Recent reports indicate that a growing number of intracellular proteins are not only prone to pathological aggregation but can also be released and "infect" neighboring cells. Therefore, many complex diseases may obey a simple model of propagation where the penetration of seeds into hosts determines spatial spread and disease progression. We term these proteins prionoids, as they appear to infect their neighbors just like prions--but how can bulky protein aggregates be released from cells and how do they access other cells? The widespread existence of such prionoids raises unexpected issues that question our understanding of basic cell biology.
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Affiliation(s)
- Adriano Aguzzi
- Institute of Neuropathology, University Hospital of Zürich, Schmelzbergstrasse 12, CH-8091 Zürich, Switzerland.
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