1
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Paryani F, Kwon JS, Ng CW, Jakubiak K, Madden N, Ofori K, Tang A, Lu H, Xia S, Li J, Mahajan A, Davidson SM, Basile AO, McHugh C, Vonsattel JP, Hickman R, Zody MC, Housman DE, Goldman JE, Yoo AS, Menon V, Al-Dalahmah O. Multi-omic analysis of Huntington's disease reveals a compensatory astrocyte state. Nat Commun 2024; 15:6742. [PMID: 39112488 PMCID: PMC11306246 DOI: 10.1038/s41467-024-50626-0] [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: 09/17/2023] [Accepted: 07/09/2024] [Indexed: 08/10/2024] Open
Abstract
The mechanisms underlying the selective regional vulnerability to neurodegeneration in Huntington's disease (HD) have not been fully defined. To explore the role of astrocytes in this phenomenon, we used single-nucleus and bulk RNAseq, lipidomics, HTT gene CAG repeat-length measurements, and multiplexed immunofluorescence on HD and control post-mortem brains. We identified genes that correlated with CAG repeat length, which were enriched in astrocyte genes, and lipidomic signatures that implicated poly-unsaturated fatty acids in sensitizing neurons to cell death. Because astrocytes play essential roles in lipid metabolism, we explored the heterogeneity of astrocytic states in both protoplasmic and fibrous-like (CD44+) astrocytes. Significantly, one protoplasmic astrocyte state showed high levels of metallothioneins and was correlated with the selective vulnerability of distinct striatal neuronal populations. When modeled in vitro, this state improved the viability of HD-patient-derived spiny projection neurons. Our findings uncover key roles of astrocytic states in protecting against neurodegeneration in HD.
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Affiliation(s)
- Fahad Paryani
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Ji-Sun Kwon
- Department of Developmental Biology Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Christopher W Ng
- Massachusetts Institute of Technology, Department of Biological Engineering, Cambridge, MA, USA
| | - Kelly Jakubiak
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Nacoya Madden
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Kenneth Ofori
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Alice Tang
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Hong Lu
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Shengnan Xia
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Juncheng Li
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Aayushi Mahajan
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Shawn M Davidson
- Northwestern Feinberg School of Medicine, Northwestern University, Evanston, IL, USA
| | | | | | - Jean Paul Vonsattel
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Richard Hickman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | | | - David E Housman
- Massachusetts Institute of Technology, Department of Biological Engineering, Cambridge, MA, USA
| | - James E Goldman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, New York, NY, USA
| | - Andrew S Yoo
- Department of Developmental Biology Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Vilas Menon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA.
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, New York, NY, USA.
| | - Osama Al-Dalahmah
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA.
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, New York, NY, USA.
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2
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Estevez-Fraga C, Altmann A, Parker CS, Scahill RI, Costa B, Chen Z, Manzoni C, Zarkali A, Durr A, Roos RAC, Landwehrmeyer B, Leavitt BR, Rees G, Tabrizi SJ, McColgan P. Genetic topography and cortical cell loss in Huntington's disease link development and neurodegeneration. Brain 2023; 146:4532-4546. [PMID: 37587097 PMCID: PMC10629790 DOI: 10.1093/brain/awad275] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/12/2023] [Accepted: 07/28/2023] [Indexed: 08/18/2023] Open
Abstract
Cortical cell loss is a core feature of Huntington's disease (HD), beginning many years before clinical motor diagnosis, during the premanifest stage. However, it is unclear how genetic topography relates to cortical cell loss. Here, we explore the biological processes and cell types underlying this relationship and validate these using cell-specific post-mortem data. Eighty premanifest participants on average 15 years from disease onset and 71 controls were included. Using volumetric and diffusion MRI we extracted HD-specific whole brain maps where lower grey matter volume and higher grey matter mean diffusivity, relative to controls, were used as proxies of cortical cell loss. These maps were combined with gene expression data from the Allen Human Brain Atlas (AHBA) to investigate the biological processes relating genetic topography and cortical cell loss. Cortical cell loss was positively correlated with the expression of developmental genes (i.e. higher expression correlated with greater atrophy and increased diffusivity) and negatively correlated with the expression of synaptic and metabolic genes that have been implicated in neurodegeneration. These findings were consistent for diffusion MRI and volumetric HD-specific brain maps. As wild-type huntingtin is known to play a role in neurodevelopment, we explored the association between wild-type huntingtin (HTT) expression and developmental gene expression across the AHBA. Co-expression network analyses in 134 human brains free of neurodegenerative disorders were also performed. HTT expression was correlated with the expression of genes involved in neurodevelopment while co-expression network analyses also revealed that HTT expression was associated with developmental biological processes. Expression weighted cell-type enrichment (EWCE) analyses were used to explore which specific cell types were associated with HD cortical cell loss and these associations were validated using cell specific single nucleus RNAseq (snRNAseq) data from post-mortem HD brains. The developmental transcriptomic profile of cortical cell loss in preHD was enriched in astrocytes and endothelial cells, while the neurodegenerative transcriptomic profile was enriched for neuronal and microglial cells. Astrocyte-specific genes differentially expressed in HD post-mortem brains relative to controls using snRNAseq were enriched in the developmental transcriptomic profile, while neuronal and microglial-specific genes were enriched in the neurodegenerative transcriptomic profile. Our findings suggest that cortical cell loss in preHD may arise from dual pathological processes, emerging as a consequence of neurodevelopmental changes, at the beginning of life, followed by neurodegeneration in adulthood, targeting areas with reduced expression of synaptic and metabolic genes. These events result in age-related cell death across multiple brain cell types.
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Affiliation(s)
- Carlos Estevez-Fraga
- Department of Neurodegenerative Disease, University College London, London WC1B 5EH, UK
| | - Andre Altmann
- Centre for Medical Image Computing, University College London, London WC1V 6LJ, UK
| | - Christopher S Parker
- Centre for Medical Image Computing, University College London, London WC1V 6LJ, UK
| | - Rachael I Scahill
- Department of Neurodegenerative Disease, University College London, London WC1B 5EH, UK
| | - Beatrice Costa
- Department of Neurodegenerative Disease, University College London, London WC1B 5EH, UK
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Zhongbo Chen
- Department of Neurodegenerative Disease, University College London, London WC1B 5EH, UK
| | - Claudia Manzoni
- School of Pharmacy, University College London, London WC1N 1AX, UK
| | - Angeliki Zarkali
- Dementia Research Centre, University College London, London WC1N 3AR, UK
| | - Alexandra Durr
- Sorbonne Université, Paris Brain Institute (ICM), AP-HP, Inserm, CNRS, Paris 75013, France
| | - Raymund A C Roos
- Department of Neurology, Leiden University Medical Centre, Leiden 2333, The Netherlands
| | | | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver BC V5Z 4H4Canada
- Division of Neurology, Department of Medicine, University of British Columbia Hospital, Vancouver BC V6T 2B5, Canada
| | - Geraint Rees
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
| | - Sarah J Tabrizi
- Department of Neurodegenerative Disease, University College London, London WC1B 5EH, UK
| | - Peter McColgan
- Department of Neurodegenerative Disease, University College London, London WC1B 5EH, UK
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3
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Paryani F, Kwon JS, Ng CW, Madden N, Ofori K, Tang A, Lu H, Li J, Mahajan A, Davidson SM, Basile A, McHugh C, Vonsattel JP, Hickman R, Zody M, Houseman DE, Goldman JE, Yoo AS, Menon V, Al-Dalahmah O. Multi-OMIC analysis of Huntington disease reveals a neuroprotective astrocyte state. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.08.556867. [PMID: 37745577 PMCID: PMC10515780 DOI: 10.1101/2023.09.08.556867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Huntington disease (HD) is an incurable neurodegenerative disease characterized by neuronal loss and astrogliosis. One hallmark of HD is the selective neuronal vulnerability of striatal medium spiny neurons. To date, the underlying mechanisms of this selective vulnerability have not been fully defined. Here, we employed a multi-omic approach including single nucleus RNAseq (snRNAseq), bulk RNAseq, lipidomics, HTT gene CAG repeat length measurements, and multiplexed immunofluorescence on post-mortem brain tissue from multiple brain regions of HD and control donors. We defined a signature of genes that is driven by CAG repeat length and found it enriched in astrocytic and microglial genes. Moreover, weighted gene correlation network analysis showed loss of connectivity of astrocytic and microglial modules in HD and identified modules that correlated with CAG-repeat length which further implicated inflammatory pathways and metabolism. We performed lipidomic analysis of HD and control brains and identified several lipid species that correlate with HD grade, including ceramides and very long chain fatty acids. Integration of lipidomics and bulk transcriptomics identified a consensus gene signature that correlates with HD grade and HD lipidomic abnormalities and implicated the unfolded protein response pathway. Because astrocytes are critical for brain lipid metabolism and play important roles in regulating inflammation, we analyzed our snRNAseq dataset with an emphasis on astrocyte pathology. We found two main astrocyte types that spanned multiple brain regions; these types correspond to protoplasmic astrocytes, and fibrous-like - CD44-positive, astrocytes. HD pathology was differentially associated with these cell types in a region-specific manner. One protoplasmic astrocyte cluster showed high expression of metallothionein genes, the depletion of this cluster positively correlated with the depletion of vulnerable medium spiny neurons in the caudate nucleus. We confirmed that metallothioneins were increased in cingulate HD astrocytes but were unchanged or even decreased in caudate astrocytes. We combined existing genome-wide association studies (GWAS) with a GWA study conducted on HD patients from the original Venezuelan cohort and identified a single-nucleotide polymorphism in the metallothionein gene locus associated with delayed age of onset. Functional studies found that metallothionein overexpressing astrocytes are better able to buffer glutamate and were neuroprotective of patient-derived directly reprogrammed HD MSNs as well as against rotenone-induced neuronal death in vitro. Finally, we found that metallothionein-overexpressing astrocytes increased the phagocytic activity of microglia in vitro and increased the expression of genes involved in fatty acid binding. Together, we identified an astrocytic phenotype that is regionally-enriched in less vulnerable brain regions that can be leveraged to protect neurons in HD.
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Affiliation(s)
- Fahad Paryani
- Department of Neurology, Columbia University Irving Medical Center
| | - Ji-Sun Kwon
- Washington University School of Medicine in St. Louis
| | - Chris W Ng
- Massachusetts Institute of Technology, Department of Biological Engineering
| | - Nacoya Madden
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Kenneth Ofori
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Alice Tang
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Hong Lu
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Juncheng Li
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Aayushi Mahajan
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Shawn M. Davidson
- Princeton University, Lewis-Sigler Institute for Integrative Genomics
| | | | | | - Jean Paul Vonsattel
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Richard Hickman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | | | - David E. Houseman
- Massachusetts Institute of Technology, Department of Biological Engineering
| | - James E. Goldman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
| | - Andrew S. Yoo
- Washington University School of Medicine in St. Louis
| | - Vilas Menon
- Department of Neurology, Columbia University Irving Medical Center
| | - Osama Al-Dalahmah
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center
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4
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Lee HG, Wheeler MA, Quintana FJ. Function and therapeutic value of astrocytes in neurological diseases. Nat Rev Drug Discov 2022; 21:339-358. [PMID: 35173313 PMCID: PMC9081171 DOI: 10.1038/s41573-022-00390-x] [Citation(s) in RCA: 177] [Impact Index Per Article: 88.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2022] [Indexed: 12/20/2022]
Abstract
Astrocytes are abundant glial cells in the central nervous system (CNS) that perform diverse functions in health and disease. Astrocyte dysfunction is found in numerous diseases, including multiple sclerosis, Alzheimer disease, Parkinson disease, Huntington disease and neuropsychiatric disorders. Astrocytes regulate glutamate and ion homeostasis, cholesterol and sphingolipid metabolism and respond to environmental factors, all of which have been implicated in neurological diseases. Astrocytes also exhibit significant heterogeneity, driven by developmental programmes and stimulus-specific cellular responses controlled by CNS location, cell-cell interactions and other mechanisms. In this Review, we highlight general mechanisms of astrocyte regulation and their potential as therapeutic targets, including drugs that alter astrocyte metabolism, and therapies that target transporters and receptors on astrocytes. Emerging ideas, such as engineered probiotics and glia-to-neuron conversion therapies, are also discussed. We further propose a concise nomenclature for astrocyte subsets that we use to highlight the roles of astrocytes and specific subsets in neurological diseases.
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Affiliation(s)
- Hong-Gyun Lee
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michael A Wheeler
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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5
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Kim T, Song B, Lee IS. Drosophila Glia: Models for Human Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2020; 21:E4859. [PMID: 32660023 PMCID: PMC7402321 DOI: 10.3390/ijms21144859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are key players in the proper formation and maintenance of the nervous system, thus contributing to neuronal health and disease in humans. However, little is known about the molecular pathways that govern glia-neuron communications in the diseased brain. Drosophila provides a useful in vivo model to explore the conserved molecular details of glial cell biology and their contributions to brain function and disease susceptibility. Herein, we review recent studies that explore glial functions in normal neuronal development, along with Drosophila models that seek to identify the pathological implications of glial defects in the context of various central nervous system disorders.
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Affiliation(s)
| | | | - Im-Soon Lee
- Department of Biological Sciences, Center for CHANS, Konkuk University, Seoul 05029, Korea; (T.K.); (B.S.)
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6
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Stanek LM, Bu J, Shihabuddin LS. Astrocyte transduction is required for rescue of behavioral phenotypes in the YAC128 mouse model with AAV-RNAi mediated HTT lowering therapeutics. Neurobiol Dis 2019; 129:29-37. [DOI: 10.1016/j.nbd.2019.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/14/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022] Open
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7
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Zwarts L, Van Eijs F, Callaerts P. Glia in Drosophila behavior. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 201:879-93. [PMID: 25336160 DOI: 10.1007/s00359-014-0952-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 10/02/2014] [Accepted: 10/07/2014] [Indexed: 02/06/2023]
Abstract
Glial cells constitute about 10 % of the Drosophila nervous system. The development of genetic and molecular tools has helped greatly in defining different types of glia. Furthermore, considerable progress has been made in unraveling the mechanisms that control the development and differentiation of Drosophila glia. By contrast, the role of glia in adult Drosophila behavior is not well understood. We here summarize recent work describing the role of glia in normal behavior and in Drosophila models for neurological and behavioral disorders.
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Affiliation(s)
- L Zwarts
- Laboratory of Behavioral and Developmental Genetics VIB Center for the Biology of Disease, Center for Human Genetics, KULeuven, O&N IV Herestraat 49, Box 602, 3000, Louvain, Belgium
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8
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Valenza M, Marullo M, Di Paolo E, Cesana E, Zuccato C, Biella G, Cattaneo E. Disruption of astrocyte-neuron cholesterol cross talk affects neuronal function in Huntington's disease. Cell Death Differ 2014; 22:690-702. [PMID: 25301063 DOI: 10.1038/cdd.2014.162] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/13/2014] [Accepted: 09/03/2014] [Indexed: 01/22/2023] Open
Abstract
In the adult brain, neurons require local cholesterol production, which is supplied by astrocytes through apoE-containing lipoproteins. In Huntington's disease (HD), such cholesterol biosynthesis in the brain is severely reduced. Here we show that this defect, occurring in astrocytes, is detrimental for HD neurons. Astrocytes bearing the huntingtin protein containing increasing CAG repeats secreted less apoE-lipoprotein-bound cholesterol in the medium. Conditioned media from HD astrocytes and lipoprotein-depleted conditioned media from wild-type (wt) astrocytes were equally detrimental in a neurite outgrowth assay and did not support synaptic activity in HD neurons, compared with conditions of cholesterol supplementation or conditioned media from wt astrocytes. Molecular perturbation of cholesterol biosynthesis and efflux in astrocytes caused similarly altered astrocyte-neuron cross talk, whereas enhancement of glial SREBP2 and ABCA1 function reversed the aspects of neuronal dysfunction in HD. These findings indicate that astrocyte-mediated cholesterol homeostasis could be a potential therapeutic target to ameliorate neuronal dysfunction in HD.
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Affiliation(s)
- M Valenza
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - M Marullo
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - E Di Paolo
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - E Cesana
- Department of Biology and Biotechnology, Università degli Studi di Pavia, Pavia, Italy
| | - C Zuccato
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - G Biella
- Department of Biology and Biotechnology, Università degli Studi di Pavia, Pavia, Italy
| | - E Cattaneo
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
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9
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Cicchetti F, Soulet D, Freeman TB. Neuronal degeneration in striatal transplants and Huntington's disease: potential mechanisms and clinical implications. Brain 2011; 134:641-52. [DOI: 10.1093/brain/awq328] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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10
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Changes in key hypothalamic neuropeptide populations in Huntington disease revealed by neuropathological analyses. Acta Neuropathol 2010; 120:777-88. [PMID: 20821223 DOI: 10.1007/s00401-010-0742-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 08/19/2010] [Accepted: 08/21/2010] [Indexed: 10/19/2022]
Abstract
Huntington disease (HD) is a fatal neurodegenerative disorder caused by expansion of a CAG repeat in the HD gene. Degeneration concentrating in the basal ganglia has been thought to account for the characteristic psychiatric symptoms, cognitive decline and motor dysfunction. However, the homeostatic control of emotions and metabolism are disturbed early in HD, and focused studies have identified a loss of orexin (hypocretin) neurons in the lateral hypothalamus in HD patients. There has been limited assessment of other hypothalamic cell populations that may be involved. In this study, we quantified the neuropeptide-expressing hypothalamic neurons known to regulate metabolism and emotion in patients with HD compared to healthy controls using unbiased stereological methods. We confirmed the loss of orexin-expressing neurons in HD and revealed substantial differences in the peptide expression of other neuronal populations in the same patients. Both oxytocin- and vasopressin-expressing neurons were decreased by 45 and 24%, respectively, while the number of cocaine- and amphetamine-regulated transcript (CART)-expressing neurons was increased by 30%. The increased expression of CART in the hypothalamus is consistent with a previous study showing increased CART levels in cerebrospinal fluid from HD patients. There was no difference in the numbers of neuropeptide Y-expressing neurons. These results show significant and specific alterations in the peptide expression of hypothalamic neurons known to regulate metabolism and emotion. They may be important in the development of psychiatric symptoms and metabolic disturbances in HD, and may provide potential targets for therapeutic interventions.
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11
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Besson MT, Dupont P, Fridell YWC, Liévens JC. Increased energy metabolism rescues glia-induced pathology in a Drosophila model of Huntington's disease. Hum Mol Genet 2010; 19:3372-82. [DOI: 10.1093/hmg/ddq249] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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12
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Pandey M, Mohanakumar KP, Usha R. Mitochondrial functional alterations in relation to pathophysiology of Huntington’s disease. J Bioenerg Biomembr 2010; 42:217-26. [DOI: 10.1007/s10863-010-9288-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Bradford J, Shin JY, Roberts M, Wang CE, Sheng G, Li S, Li XJ. Mutant huntingtin in glial cells exacerbates neurological symptoms of Huntington disease mice. J Biol Chem 2010; 285:10653-61. [PMID: 20145253 PMCID: PMC2856273 DOI: 10.1074/jbc.m109.083287] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 02/01/2010] [Indexed: 01/17/2023] Open
Abstract
Huntington disease (HD) is caused by an expansion of the polyglutamine (polyQ) repeat (>37Q) in huntingtin (htt), and age of onset is inversely correlated with the length of the polyQ repeat. Mutant htt with expanded polyQ is ubiquitously expressed in various types of cells, including glia, but causes selective neurodegeneration. Our recent study demonstrated that expression of the N-terminal mutant htt with a large polyQ repeat (160Q) in astrocytes is sufficient to induce neurological symptoms in mice (Bradford, J., Shin, J. Y., Roberts, M., Wang, C. E., Li, X.-J., and Li, S. H. (2009) Proc. Natl. Acad. Sci. U.S.A. 106, 22480-22485). Because glia-neuron interactions are critical for maintaining the normal function and survival of neurons in the brain and because mutant htt is more abundant in neurons than in glial cells, it is important to investigate whether glial htt can still contribute to HD pathology when mutant htt is abundantly expressed in neuronal cells. We generated transgenic mice that express mutant htt with 98Q in astrocytes. Unlike our recently generated htt-160Q transgenic mice, htt-98Q mice do not show obvious neurological phenotypes, suggesting that the length of the polyQ repeat determines the severity of glial dysfunction. However, htt-98Q mice show increased susceptibility to glutamate-induced seizure. Mice expressing mutant htt in astrocytes were mated with N171-82Q mice that express mutant htt primarily in neuronal cells. Double transgenic mice expressing mutant htt in both neuronal and glial cells display more severe neurological symptoms and earlier death than N171-82Q mice. These findings indicate a role of glial mutant htt in exacerbating HD neuropathology and underscore the importance of improving glial function in treating HD.
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Affiliation(s)
- Jennifer Bradford
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Ji-Yeon Shin
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Meredith Roberts
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Chuan-En Wang
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Guoqing Sheng
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Shihua Li
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Xiao-Jiang Li
- From the Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
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14
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Bradford J, Shin JY, Roberts M, Wang CE, Li XJ, Li S. Expression of mutant huntingtin in mouse brain astrocytes causes age-dependent neurological symptoms. Proc Natl Acad Sci U S A 2009; 106:22480-5. [PMID: 20018729 PMCID: PMC2799722 DOI: 10.1073/pnas.0911503106] [Citation(s) in RCA: 255] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Indexed: 11/18/2022] Open
Abstract
Huntington disease (HD) is an inherited neurological disorder caused by a polyglutamine expansion in the protein huntingtin and is characterized by selective neurodegeneration that preferentially occurs in striatal medium spiny neurons. Because the medium spiny neurons are innervated abundantly by glutamatergic axons from cortical neurons, the preferential degeneration in the striatal neurons supports the glutamate excitotoxicity theory for HD pathogenesis. Thus, glutamate uptake by glia may be particularly important for preventing glutamate excitotoxicity in HD. Although mutant huntingtin is expressed ubiquitously in various types of cells, it accumulates and forms aggregates in fewer glial cells than in neuronal cells. It remains largely unknown whether and how mutant huntingtin in glia can contribute to the neurological symptoms of HD. We generated transgenic mice that express N-terminal mutant huntingtin in astrocytes, a major type of glial cell that remove extracellular glutamate in the brain. Although transgenic mutant huntingtin in astrocytes is expressed below the endogenous level, it can cause age-dependent neurological phenotypes in transgenic mice. Mice expressing mutant huntingtin show body weight loss, have motor function deficits, and die earlier than wild-type or control transgenic mice. We also found that mutant huntingtin in astrocytes decreases the expression of glutamate transporter by increasing its binding to Sp1 and reducing the association of Sp1 with the promoter of glutamate transporter. These results imply an important role for glial mutant huntingtin in HD pathology and suggest possibilities for treatment.
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Affiliation(s)
- Jennifer Bradford
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322
| | - Ji-Yeon Shin
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322
| | - Meredith Roberts
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322
| | - Chuan-En Wang
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322
| | - Xiao-Jiang Li
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322
| | - Shihua Li
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322
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15
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Wang L, Lin F, Wu J, Qin Z. High efficiency adenovirus-mediated expression of truncated N-terminal huntingtin fragment (htt552) in primary rat astrocytes. Acta Biochim Biophys Sin (Shanghai) 2009; 41:325-34. [PMID: 19352548 DOI: 10.1093/abbs/gmp021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Huntington's disease (HD) is caused by an expansion of polyglutamine tract in N-terminus of huntingtin (htt). The mutation of htt leads to dysfunction and premature death of striatal and cortical neurons. However, the effects of htt mutation on glia remain largely unknown. This study aimed to establish a glia HD model using an adenoviral vector to express wild-type and mutant N-terminal huntingtin fragment 1-552 amino acids (htt552) in rat primary cortical astrocytes. We have evaluated optimal conditions for the infection of astrocytes with adenoviral vectors, and the kinetics of the expression of htt552 in astrocytes. The majority of astrocytes expressed the transgene after infection. At 24 h postinfection, the highest rate of infection was 89+/-3% for the wild-type (htt552-18Q) with a multiplicity of infection (m.o.i.) of 80, and the highest rate of infection was 91+/-4% for the mutant type (htt552-100Q) with the same viral dose. The duration of expression of htt552 lasted for about 7 days with a relatively high level from 1 to 4 days post-infection. Mutant huntingtin (htt552-100Q) produced the characteristic HD pathology after 3 days by the appearance of cytoplasmic aggregates and intranuclear inclusions. The result of MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] assay showed that the inhibition of viability by virus on astrocytes was also dose-dependent. To obtain high infection rate and low toxicity, the viral dose with an m.o.i. of 40 was optimal to our cell model. The present study demonstrates that adenoviral-mediated expression of mutant htt provides an advantageous system for histological and biochemical analysis of HD pathogenesis in primary cortical astrocyte cultures.
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Affiliation(s)
- Linhui Wang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Medicine, Suzhou 215123, China
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16
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Expanded-polyglutamine huntingtin protein suppresses the secretion and production of a chemokine (CCL5/RANTES) by astrocytes. J Neurosci 2008; 28:3277-90. [PMID: 18367595 DOI: 10.1523/jneurosci.0116-08.2008] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Huntington's disease (HD) is a hereditary neurological disease caused by expended CAG repeats in the HD gene, which codes for a protein called Huntingtin (Htt). The resultant mutant Huntingtin (mHtt) forms aggregates in neurons and causes neuronal dysfunction. In astrocytes, the largest population of brain cells, mHtt also exists. We report herein that astrocyte-conditioned medium (ACM) collected from astrocytes of R6/2 mice (a mouse model of HD) caused primary cortical neurons to grow less-mature neurites, migrate more slowly, and exhibit lower calcium influx after depolarization than those maintained in wild-type (WT) ACM. Using a cytokine antibody array and ELISA assays, we demonstrated that the amount of a chemokine [chemokine (C-C motif) ligand 5 (CCL5)/regulated on activation normal T cell expressed and secreted (RANTES)] released by R6/2 astrocytes was much less than that by WT astrocytes. When cortical neurons were treated with the indicated ACM, supplementation with recombinant CCL5/RANTES ameliorated the neuronal deficiency caused by HD-ACM, whereas removing CCL5/RANTES from WT-ACM using an anti-CCL5/RANTES antibody mimicked the effects evoked by HD-ACM. Quantitative PCR and promoter analyses demonstrated that mHtt hindered the activation of the CCL5/RANTES promoter by reducing the availability of nuclear factor kappaB-p65 and, hence, reduced the transcript level of CCL5/RANTES. Moreover, ELISA assays and immunocytochemical staining revealed that mHtt retained the residual CCL5/RANTES inside R6/2 astrocytes. In line with the above findings, elevated cytosolic CCL5/RANTES levels were also observed in the brains of two mouse models of HD [R6/2 and Hdh((CAG)150)] and human HD patients. These findings suggest that mHtt hinders one major trophic function of astrocytes which might contribute to the neuronal dysfunction of HD.
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Aziz NA, Swaab DF, Pijl H, Roos RAC. Hypothalamic dysfunction and neuroendocrine and metabolic alterations in Huntington's disease: clinical consequences and therapeutic implications. Rev Neurosci 2007; 18:223-51. [PMID: 18019608 DOI: 10.1515/revneuro.2007.18.3-4.223] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by cognitive, psychiatric, behavioural and motor disturbances. Although the course of HD is also frequently complicated by unintended weight loss, sleep disturbances and autonomic nervous system dysfunction, the aetiology of these signs and symptoms remains largely unknown. In recent years, many novel findings from both animal and human studies have emerged that indicate considerable hypothalamic, endocrine and metabolic alterations in HD. However, a comprehensive overview of these findings is lacking and their precise clinical significance is far from clear. Therefore, in this review we attempt to put these recent developments in the field into perspective by integrating them with previous findings in a comprehensible manner, and by discussing their clinical relevance, with a special focus on body weight, sleep and autonomic functions in HD, which will also allow for the identification of future lines of research in this area.
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Affiliation(s)
- N A Aziz
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.
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18
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19
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Hassel B, Tessler S, Faull RLM, Emson PC. Glutamate uptake is reduced in prefrontal cortex in Huntington's disease. Neurochem Res 2007; 33:232-7. [PMID: 17726644 DOI: 10.1007/s11064-007-9463-1] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2006] [Accepted: 07/26/2007] [Indexed: 11/29/2022]
Abstract
Huntington's disease (HD) is caused by a CAG repeat expansion in the HD gene, but how this mutation causes neuronal dysfunction and degeneration is unclear. Inhibition of glutamate uptake, which could cause excessive stimulation of glutamate receptors, has been found in animals carrying very long CAG repeats in the HD gene. In seven HD patients with moderate CAG expansions (40-52), repeat expansion and HD grade at autopsy were strongly correlated (r=0.88, p=0.0002). Uptake of [(3)H]glutamate was reduced by 43% in prefrontal cortex, but the level of synaptic (synaptophysin, AMPA receptors) and astrocytic markers (GFAP, glutamate transporter EAAT1) were unchanged. Glutamate uptake correlated inversely with CAG repeat expansion (r= -0.82, p=0.015). The reducing agent dithiothreitol improved glutamate uptake in controls, but not in HD brains, suggesting irreversible oxidation of glutamate transporters in HD. We conclude that impairment of glutamate uptake may contribute to neuronal dysfunction and degeneration in HD.
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Affiliation(s)
- Bjørnar Hassel
- Norwegian Defense Research Establishment, P.O. Box 25, 2027 Kjeller, Norway.
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20
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Crocker SF, Costain WJ, Robertson HA. DNA microarray analysis of striatal gene expression in symptomatic transgenic Huntington's mice (R6/2) reveals neuroinflammation and insulin associations. Brain Res 2006; 1088:176-86. [PMID: 16626669 DOI: 10.1016/j.brainres.2006.02.102] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 02/03/2006] [Accepted: 02/26/2006] [Indexed: 11/21/2022]
Abstract
Huntington's disease (HD) is an inherited, progressive neurodegenerative disorder caused by CAG repeat expansion in the gene that codes for the protein huntingtin. The underlying neuropathological events leading to the selectivity of striatal neuronal loss are unknown. However, the huntingtin mutation interferes at several levels of normal cell function. The complexity of this disease makes microarray analysis an appealing technique to begin the identification of common pathways that may contribute to the pathology. In this study, striatal tissue was extracted for gene expression profiling from wild-type and symptomatic transgenic Huntington mice (R6/2) expressing part of the human Huntington's disease gene. We interrogated a 15 K high-density mouse EST array not previously used for HD and identified 170 significantly differentially expressed ESTs in symptomatic R6/2 mice. Of the 80 genes with known function, 9 genes had previously been identified as altered in HD. 71 known genes were associated with HD for the first time. The data obtained from this study confirm and extend previous observations using DNA microarray techniques on genetic models for HD, revealing novel changes in expression in a number of genes not previously associated with HD. Further bioinformatic analysis, using software to construct biological association maps, focused attention on proteins such as insulin and TH1-mediated cytokines, suggesting that they may be important regulators of affected genes. These results may provide insight into the regulation and interaction of genes that contribute to adaptive and pathological processes involved in HD.
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Affiliation(s)
- Susan F Crocker
- Brain Repair Centre, Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
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21
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Shin JY, Fang ZH, Yu ZX, Wang CE, Li SH, Li XJ. Expression of mutant huntingtin in glial cells contributes to neuronal excitotoxicity. ACTA ACUST UNITED AC 2006; 171:1001-12. [PMID: 16365166 PMCID: PMC2171327 DOI: 10.1083/jcb.200508072] [Citation(s) in RCA: 332] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Huntington disease (HD) is characterized by the preferential loss of striatal medium-sized spiny neurons (MSNs) in the brain. Because MSNs receive abundant glutamatergic input, their vulnerability to excitotoxicity may be largely influenced by the capacity of glial cells to remove extracellular glutamate. However, little is known about the role of glia in HD neuropathology. Here, we report that mutant huntingtin accumulates in glial nuclei in HD brains and decreases the expression of glutamate transporters. As a result, mutant huntingtin (htt) reduces glutamate uptake in cultured astrocytes and HD mouse brains. In a neuron-glia coculture system, wild-type glial cells protected neurons against mutant htt-mediated neurotoxicity, whereas glial cells expressing mutant htt increased neuronal vulnerability. Mutant htt in cultured astrocytes decreased their protection of neurons against glutamate excitotoxicity. These findings suggest that decreased glutamate uptake caused by glial mutant htt may critically contribute to neuronal excitotoxicity in HD.
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Affiliation(s)
- Ji-Yeon Shin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
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22
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Kretzschmar D, Tschäpe J, Bettencourt Da Cruz A, Asan E, Poeck B, Strauss R, Pflugfelder GO. Glial and neuronal expression of polyglutamine proteins induce behavioral changes and aggregate formation in Drosophila. Glia 2005; 49:59-72. [PMID: 15390099 DOI: 10.1002/glia.20098] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Patients with polyglutamine expansion diseases, like Huntington's disease or several spinocerebellar ataxias, first present with neurological symptoms that can occur in the absence of neurodegeneration. Behavioral symptoms thus appear to be caused by neuronal dysfunction, rather than cell death. Pathogenesis in polyglutamine expansion diseases is largely viewed as a cell-autonomous process in neurons. It is likely, however, that this process is influenced by changes in glial physiology and, at least in the case of DRPLA glial inclusions and glial cell death, seems to be an important part in the pathogenesis. To investigate these aspects in a Drosophila model system, we expressed polyglutamine proteins in the adult nervous system. Glial-specific expression of a polyglutamine (Q)-expanded (n=78) and also a nonexpanded (n=27) truncated version of human ataxin-3 led to the formation of protein aggregates and glial cell death. Behavioral changes were observed prior to cell death. This reveals that glia is susceptible to the toxic action of polyglutamine proteins. Neuronal expression of the same constructs resulted in behavioral changes similar to those resulting from glial expression but did not cause neurodegeneration. Behavioral deficits were selective and affected two analyzed fly behaviors differently. Both glial and neuronal aggregates of Q78 and Q27 appeared early in pathogenesis and, at the electron microscopic resolution, had a fibrillary substructure. This shows that a nonexpanded stretch can cause similar histological and behavioral symptoms as the expanded stretch, however, with a significant delay.
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Affiliation(s)
- Doris Kretzschmar
- Lehrstuhl für Genetik und Neurobiologie, Biozentrum, Universität Würzburg, Würzburg, Germany.
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23
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Liévens JC, Rival T, Iché M, Chneiweiss H, Birman S. Expanded polyglutamine peptides disrupt EGF receptor signaling and glutamate transporter expression in Drosophila. Hum Mol Genet 2005; 14:713-24. [PMID: 15677486 DOI: 10.1093/hmg/ddi067] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Huntington's disease (HD) is a late onset heritable neurodegenerative disorder caused by expansion of a polyglutamine (polyQ) sequence in the protein huntingtin (Htt). Transgenic models in mice have suggested that the motor and cognitive deficits associated to this disease are triggered by extended neuronal and possibly glial dysfunction, whereas neuronal death occurs late and selectively. Here, we provide in vivo evidence that expanded polyQ peptides antagonize epidermal growth factor receptor (EGFR) signaling in Drosophila glia. We targeted the expression of the polyQ-containing domain of Htt or an extended polyQ peptide alone in a subset of Drosophila glial cells, where the only fly glutamate transporter, dEAAT1, is detected. This resulted in formation of nuclear inclusions, progressive decrease in dEAAT1 transcription and shortened adult lifespan, but no significant glial cell death. We observed that brain expression of dEAAT1 is normally sustained by the EGFR-Ras-extracellular signal-regulated kinase (ERK) signaling pathway, suggesting that polyQ could act by antagonizing this pathway. We found that the presence of polyQ peptides indeed abolished dEAAT1 upregulation by constitutively active EGFR and potently inhibited EGFR-mediated ERK activation in fly glial cells. Long polyQ also limited the effect of activated EGFR on Drosophila eye development. Our results further indicate that the polyQ acts at an upstream step in the pathway, situated between EGFR and ERK activation. This suggests that disruption of EGFR signaling and ensuing glial cell dysfunction could play a direct role in the pathogenesis of HD and other polyQ diseases in humans.
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Reiner A, Dragatsis I, Zeitlin S, Goldowitz D. Wild-type huntingtin plays a role in brain development and neuronal survival. Mol Neurobiol 2004; 28:259-76. [PMID: 14709789 DOI: 10.1385/mn:28:3:259] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2003] [Accepted: 05/23/2003] [Indexed: 11/11/2022]
Abstract
While the role of the mutated Huntington's disease (HD) protein in the pathogenesis of HD has been the focus of intensive investigation, the normal protein has received less attention. Nonetheless, the wild-type HD protein appears to be essential for embryogenesis, since deletion of the HD gene in mice results in early embryonic lethality. This early lethality is due to a critical role the HD protein, called huntingtin (Htt), plays in extraembryonic membrane function, presumably in vesicular transport of nutrients. Studies of mutant mice expressing low levels of Htt and of chimeric mice generated by blastocyst injection of Hdh-/- embryonic stem cells show that wildtype Htt plays an important role later in development as well, specifically in forebrain formation. Moreover, various lines of study suggest that normal Htt is also critical for survival of neurons in the adult forebrain. The observation that Htt plays its key developmental and survival roles in those brain areas most affected in HD raises the possibility that a subtle loss of function on the part of the mutant protein or a sequestering of wild-type Htt by mutant Htt may contribute to HD pathogenesis. Regardless of whether this is so, the prosurvival role of Htt suggests that HD therapies that block production of both wild-type and mutant Htt may themselves be harmful.
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Affiliation(s)
- Anton Reiner
- Department of Anatomy and Neurobiology, College of Medicine, The University of Tennessee, The Health Science Center, Memphis, TN 38163.
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25
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Dixon KT, Cearley JA, Hunter JM, Detloff PJ. Mouse Huntington's disease homolog mRNA levels: variation and allele effects. Gene Expr 2004; 11:221-31. [PMID: 15200234 PMCID: PMC5991148 DOI: 10.3727/000000003783992234] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Huntington's disease homolog (Hdh) mRNA levels in mice with different Hdh alleles were measured. Brain Hdh mRNA levels varied up to threefold in genetically identical wild-type mice, indicating nongenetic factors influence Hdh expression. Striatal Hdh mRNA levels from an allele with a repeat expanded to 150 CAGs were diminished compared with wild-type and showed variation that might contribute to phenotypic variability in the Hdh(CAG)150 knock-in mouse model. To determine whether Hdh mRNA levels are tightly regulated, we assessed these levels in mice heterozygous for a deletion of the Hdh promoter. The loss of one allele reduced Hdh mRNA levels in most tissues, suggesting mechanisms to maintain Hdh mRNA levels are not in effect and should not impede therapies designed to destroy mutant huntingtin mRNA. Finally, we found a correlation between tissue mRNA levels and the susceptibility of the Hdh locus to Cre-mediated deletion. The two tissues with the highest levels of Hdh mRNA, testes and brain, were the only tissues susceptible to Cre-mediated recombination between loxP sites at Hdh locus. In contrast, the same Cre-expressing line caused recombination in every tissue for loxP sites at another genomic location. The pattern of Cre susceptibility at Hdh suggests a correlation between chromatin accessibility and high levels of Hdh expression in testes and brain.
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Affiliation(s)
- Karen T. Dixon
- *Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jamie A. Cearley
- *Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jesse M. Hunter
- *Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Peter J. Detloff
- *Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
- †Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294
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26
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Fujinaga R, Kawano J, Matsuzaki Y, Kamei K, Yanai A, Sheng Z, Tanaka M, Nakahama KI, Nagano M, Shinoda K. Neuroanatomical distribution of huntingtin-associated protein 1-mRNA in the male mouse brain. J Comp Neurol 2004; 478:88-109. [PMID: 15334651 DOI: 10.1002/cne.20277] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Huntingtin-associated protein 1 (HAP1) was identified as an interactor of the gene product (Huntingtin) responsible for Huntington's disease and found to be a core component of the stigmoid body. Even though HAP1 is highly expressed in the brain, detailed information on HAP1 distribution has not been fully described. Focusing on the neuroanatomical analysis of HAP1-mRNA expression using in situ hybridization histochemistry, the present study clarified its detailed regional distribution in the entire mouse brain. Mouse HAP1 (Hap1)-mRNAs were abundantly expressed in the limbic-related forebrain regions and midline/periventricular brainstem regions including the olfactory bulb, limbic-associated cortices, hippocampus, septum, amygdala, bed nucleus of the stria terminalis, preoptico-hypothalamic regions, central gray, raphe nuclei, locus coeruleus, parabrachial nuclei, nucleus of the solitary tract, and area postrema. In contrast, little expression was detected in the striatum and thalamus, implying that Hap1 is associated with neurodegeneration-sparing regions rather than target lesions in Huntington's disease. The distribution pattern, resembling that of the stigmoid body, suggests that HAP1 and the stigmoid body are implicated in protection from neuronal death rather than induction of neurodegeneration in Huntington's disease, and that they play an important role in integrating instinct behaviors and underlying autonomic, visceral, arousal, drive, memory, and neuroendocrinergic functions, particularly during extensive homeostatic or emotional processes. These data will provide an important morphological base for a future understanding of functions of HAP1 and the stigmoid body in the brain.
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Affiliation(s)
- Ryutaro Fujinaga
- Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University School of Medicine, Yamaguchi 755-8505, Japan
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Abstract
A milestone in Huntington's disease (HD) research is represented by the identification of the causative gene. With the genetics at hand, a series of transgenic cellular and animal models has been developed, which has greatly contributed to understanding of HD. All these models are described in this review, and are compared to each other, along with the information they have generated. Although the mechanism by which progressive loss of striatal neurons occurs in HD remains uncertain, hypotheses on mutant huntingtin toxicity involve impaired vescicular trafficking, transcriptional dysregulation, and/or activation of apoptotic pathways. The development of inducible HD mice has shown that neurodegeneration in HD may be at least partially blocked. Although traditionally considered a "gain-of-function" disease, the recent finding that normal huntingtin has an important role in neuronal survival suggests that loss of function of the normal protein might contribute to HD as well, also discloseing new perspectives on the therapeutical approach to the pathology.
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Affiliation(s)
- S Sipione
- Department of Pharmacological Sciences, University of Milano, Center of Excellence on Neurodegenerative Diseases, Italy
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Soucy F, Grenier L, Behnke ML, Destree AT, McCormack TA, Adams J, Plamondon L. A Novel and Efficient Synthesis of a Highly Active Analogue of clasto-Lactacystin β-Lactone. J Am Chem Soc 1999. [DOI: 10.1021/ja991175f] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- François Soucy
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
| | - Louis Grenier
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
| | - Mark L. Behnke
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
| | - Antonia T. Destree
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
| | - Teresa A. McCormack
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
| | - Julian Adams
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
| | - Louis Plamondon
- Contribution from the Department of Chemistry, LeukoSite, Inc., 38 Sidney Street, Cambridge, Massachusetts 02139
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