151
|
Blanco‐Suárez E, Caldwell ALM, Allen NJ. Role of astrocyte-synapse interactions in CNS disorders. J Physiol 2017; 595:1903-1916. [PMID: 27381164 PMCID: PMC5350444 DOI: 10.1113/jp270988] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/08/2016] [Indexed: 12/18/2022] Open
Abstract
Astrocytes comprise half of the cells in the brain. Although astrocytes have traditionally been described as playing a supportive role for neurons, they have recently been recognized as active participants in the development and plasticity of dendritic spines and synapses. Astrocytes can eliminate dendritic spines, induce synapse formation, and regulate neurotransmission and plasticity. Dendritic spine and synapse impairments are features of many neurological disorders, including autism spectrum disorder, schizophrenia, and Alzheimer's disease. In this review we will present evidence from multiple neurological disorders demonstrating that changes in astrocyte-synapse interaction contribute to the pathologies. Genomic analysis has connected altered astrocytic gene expression with synaptic deficits in a number of neurological disorders. Alterations in astrocyte-secreted factors have been implicated in the neuronal morphology and synaptic changes seen in neurodevelopmental disorders, while alteration in astrocytic glutamate uptake is a core feature of multiple neurodegenerative disorders. This evidence clearly demonstrates that maintaining astrocyte-synapse interaction is crucial for normal central nervous system functioning. Obtaining a better understanding of the role of astrocytes at synapses in health and disease will provide a new avenue for future therapeutic targeting.
Collapse
Affiliation(s)
- Elena Blanco‐Suárez
- Salk Institute for Biological StudiesMolecular Neuroscience Laboratory10010 North Torrey Pines RdLa JollaCA92037USA
| | - Alison L. M. Caldwell
- Salk Institute for Biological StudiesMolecular Neuroscience Laboratory10010 North Torrey Pines RdLa JollaCA92037USA
| | - Nicola J. Allen
- Salk Institute for Biological StudiesMolecular Neuroscience Laboratory10010 North Torrey Pines RdLa JollaCA92037USA
| |
Collapse
|
152
|
Rattray I, Smith EJ, Crum WR, Walker TA, Gale R, Bates GP, Modo M. Correlations of Behavioral Deficits with Brain Pathology Assessed through Longitudinal MRI and Histopathology in the HdhQ150/Q150 Mouse Model of Huntington's Disease. PLoS One 2017; 12:e0168556. [PMID: 28099507 PMCID: PMC5242535 DOI: 10.1371/journal.pone.0168556] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/03/2016] [Indexed: 12/14/2022] Open
Abstract
A variety of mouse models have been developed that express mutant huntingtin (mHTT) leading to aggregates and inclusions that model the molecular pathology observed in Huntington's disease. Here we show that although homozygous HdhQ150 knock-in mice developed motor impairments (rotarod, locomotor activity, grip strength) by 36 weeks of age, cognitive dysfunction (swimming T maze, fear conditioning, odor discrimination, social interaction) was not evident by 94 weeks. Concomitant to behavioral assessments, T2-weighted MRI volume measurements indicated a slower striatal growth with a significant difference between wild type (WT) and HdhQ150 mice being present even at 15 weeks. Indeed, MRI indicated significant volumetric changes prior to the emergence of the "clinical horizon" of motor impairments at 36 weeks of age. A striatal decrease of 27% was observed over 94 weeks with cortex (12%) and hippocampus (21%) also indicating significant atrophy. A hypothesis-free analysis using tensor-based morphometry highlighted further regions undergoing atrophy by contrasting brain growth and regional neurodegeneration. Histology revealed the widespread presence of mHTT aggregates and cellular inclusions. However, there was little evidence of correlations between these outcome measures, potentially indicating that other factors are important in the causal cascade linking the molecular pathology to the emergence of behavioral impairments. In conclusion, the HdhQ150 mouse model replicates many aspects of the human condition, including an extended pre-manifest period prior to the emergence of motor impairments.
Collapse
Affiliation(s)
- Ivan Rattray
- King’s College London, Institute of Psychiatry, Department of Neuroscience, London, United Kingdom
- King’s College London School of Medicine, Department of Medical and Molecular Genetics, Guy’s Hospital, London, United Kingdom
| | - Edward J. Smith
- King’s College London, Institute of Psychiatry, Department of Neuroscience, London, United Kingdom
- King’s College London School of Medicine, Department of Medical and Molecular Genetics, Guy’s Hospital, London, United Kingdom
| | - William R. Crum
- King’s College London, Department of Neuroimaging, Institute of Psychiatry London, United Kingdom
| | - Thomas A. Walker
- King’s College London School of Medicine, Department of Medical and Molecular Genetics, Guy’s Hospital, London, United Kingdom
| | - Richard Gale
- King’s College London School of Medicine, Department of Medical and Molecular Genetics, Guy’s Hospital, London, United Kingdom
| | - Gillian P. Bates
- King’s College London School of Medicine, Department of Medical and Molecular Genetics, Guy’s Hospital, London, United Kingdom
| | - Michel Modo
- King’s College London, Institute of Psychiatry, Department of Neuroscience, London, United Kingdom
- University of Pittsburgh, Department of Radiology, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States of America
| |
Collapse
|
153
|
Shigetomi E, Koizumi S. Visualization of diversity of calcium signals in astrocytes. Nihon Yakurigaku Zasshi 2017; 148:75-80. [PMID: 27478045 DOI: 10.1254/fpj.148.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
154
|
Atherton JF, McIver EL, Mullen MR, Wokosin DL, Surmeier DJ, Bevan MD. Early dysfunction and progressive degeneration of the subthalamic nucleus in mouse models of Huntington's disease. eLife 2016; 5. [PMID: 27995895 PMCID: PMC5199195 DOI: 10.7554/elife.21616] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 12/08/2016] [Indexed: 01/05/2023] Open
Abstract
The subthalamic nucleus (STN) is an element of cortico-basal ganglia-thalamo-cortical circuitry critical for action suppression. In Huntington's disease (HD) action suppression is impaired, resembling the effects of STN lesioning or inactivation. To explore this potential linkage, the STN was studied in BAC transgenic and Q175 knock-in mouse models of HD. At <2 and 6 months of age autonomous STN activity was impaired due to activation of KATP channels. STN neurons exhibited prolonged NMDA receptor-mediated synaptic currents, caused by a deficit in glutamate uptake, and elevated mitochondrial oxidant stress, which was ameliorated by NMDA receptor antagonism. STN activity was rescued by NMDA receptor antagonism or the break down of hydrogen peroxide. At 12 months of age approximately 30% of STN neurons had been lost, as in HD. Together, these data argue that dysfunction within the STN is an early feature of HD that may contribute to its expression and course. DOI:http://dx.doi.org/10.7554/eLife.21616.001
Collapse
Affiliation(s)
- Jeremy F Atherton
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Eileen L McIver
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Matthew Rm Mullen
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - David L Wokosin
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Mark D Bevan
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| |
Collapse
|
155
|
Seifert G, Henneberger C, Steinhäuser C. Diversity of astrocyte potassium channels: An update. Brain Res Bull 2016; 136:26-36. [PMID: 27965079 DOI: 10.1016/j.brainresbull.2016.12.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 01/08/2023]
Abstract
Astrocyte K+ channels and the K+ currents they mediate dwarf all other transmembrane conductances in these cells. This defining feature of astrocytes and its functional implications have been investigated intensely over the past decades. Nonetheless, many aspects of astrocyte K+ handling and signaling remain incompletely understood. In this review, we provide an update on the diversity of K+ channels expressed by astrocytes and new functional implications. We focus on inwardly-rectifying K+ channels (particularly Kir4.1), two-pore K+ channels and voltage and Ca2+-dependent K+ channels. We further discuss new insights into the involvement of these K+ channels in K+ buffering, control of synaptic transmission, regulation of the vasculature and in diseases of the central nervous system.
Collapse
Affiliation(s)
- Gerald Seifert
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany; German Center of Neurodegenerative Diseases (DZNE), Bonn, Germany; Institute of Neurology, University College London, London, United Kingdom
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.
| |
Collapse
|
156
|
Systemic application of AAV vectors targeting GFAP-expressing astrocytes in Z -Q175-KI Huntington's disease mice. Mol Cell Neurosci 2016; 77:76-86. [DOI: 10.1016/j.mcn.2016.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/12/2016] [Accepted: 10/24/2016] [Indexed: 01/03/2023] Open
|
157
|
Lloyd-Evans E, Haslett LJ. The lysosomal storage disease continuum with ageing-related neurodegenerative disease. Ageing Res Rev 2016; 32:104-121. [PMID: 27516378 DOI: 10.1016/j.arr.2016.07.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 07/19/2016] [Accepted: 07/29/2016] [Indexed: 12/11/2022]
Abstract
Lysosomal storage diseases and diseases of ageing share many features both at the physiological level and with respect to the mechanisms that underlie disease pathogenesis. Although the exact pathophysiology is not exactly the same, it is astounding how many similar pathways are altered in all of these diseases. The aim of this review is to provide a summary of the shared disease mechanisms, outlining the similarities and differences and how genetics, insight into rare diseases and functional research has changed our perspective on the causes underlying common diseases of ageing. The lysosome should no longer be considered as just the stomach of the cell or as a suicide bag, it has an emerging role in cellular signalling, nutrient sensing and recycling. The lysosome is of fundamental importance in the pathophysiology of diseases of ageing and by comparing against the LSDs we not only identify common pathways but also therapeutic targets so that ultimately more effective treatments can be developed for all neurodegenerative diseases.
Collapse
|
158
|
Zhang C, Wang C, Ren J, Guo X, Yun K. Morphine Protects Spinal Cord Astrocytes from Glutamate-Induced Apoptosis via Reducing Endoplasmic Reticulum Stress. Int J Mol Sci 2016; 17:ijms17101523. [PMID: 27783050 PMCID: PMC5085616 DOI: 10.3390/ijms17101523] [Citation(s) in RCA: 18] [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: 07/25/2016] [Revised: 08/30/2016] [Accepted: 09/04/2016] [Indexed: 12/24/2022] Open
Abstract
Glutamate is not only a neurotransmitter but also an important neurotoxin in central nervous system (CNS). Chronic elevation of glutamate induces both neuronal and glial cell apoptosis. However, its effect on astrocytes is complex and still remains unclear. In this study, we investigated whether morphine, a common opioid ligand, could affect glutamate-induced apoptosis in astrocytes. Primary cultured astrocytes were incubated with glutamate in the presence/absence of morphine. It was found that morphine could reduce glutamate-induced apoptosis of astrocytes. Furthermore, glutamate activated Ca2+ release, thereby inducing endoplasmic reticulum (ER) stress in astrocytes, while morphine attenuated this deleterious effect. Using siRNA to reduce the expression of κ-opioid receptor, morphine could not effectively inhibit glutamate-stimulated Ca2+ release in astrocytes, the protective effect of morphine on glutamate-injured astrocytes was also suppressed. These results suggested that morphine could protect astrocytes from glutamate-induced apoptosis via reducing Ca2+ overload and ER stress pathways. In conclusion, this study indicated that excitotoxicity participated in the glutamate mediated apoptosis in astrocytes, while morphine attenuated this deleterious effect via regulating Ca2+ release and ER stress.
Collapse
Affiliation(s)
- Chao Zhang
- Department of Forensic Medicine, Shanxi Medical University, 56 South Xinjian Road, Taiyuan 030001, China.
| | - Chendan Wang
- Department of Nephrology, People's Hospital of Shanxi Province, 29 Shuang-ta Street, Taiyuan 030012, China.
| | - Jianbo Ren
- Department of Forensic Medicine, Shanxi Medical University, 56 South Xinjian Road, Taiyuan 030001, China.
| | - Xiangjie Guo
- Department of Forensic Medicine, Shanxi Medical University, 56 South Xinjian Road, Taiyuan 030001, China.
| | - Keming Yun
- Department of Forensic Medicine, Shanxi Medical University, 56 South Xinjian Road, Taiyuan 030001, China.
| |
Collapse
|
159
|
Raymond LA. Striatal synaptic dysfunction and altered calcium regulation in Huntington disease. Biochem Biophys Res Commun 2016; 483:1051-1062. [PMID: 27423394 DOI: 10.1016/j.bbrc.2016.07.058] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/11/2016] [Indexed: 11/30/2022]
Abstract
Synaptic dysfunction and altered calcium homeostasis in the brain is common to many neurodegenerative disorders. Among these, Huntington disease (HD), which is inherited in an autosomal dominant fashion, can serve as a model for investigating these mechanisms. HD generally manifests in middle age as a disorder of movement, mood and cognition. An expanded polymorphic CAG repeat in the HTT gene results in progressive neurodegeneration that impacts striatal spiny projection neurons (SPNs) earliest and most severely. Striatal SPNs receive massive glutamatergic input from cortex and thalamus, and these excitatory synapses are a focus for early changes that can trigger aberrant downstream signaling to disrupt synaptic plasticity and lead to later degeneration. Mitochondrial dysfunction and altered intracellular calcium-induced calcium release and sequestration mechanisms add to the impairments in circuit function that may underlie prodromal cognitive and subtle motor deficits. These mechanisms and implications for developing disease-modifying therapy will be reviewed here.
Collapse
Affiliation(s)
- Lynn A Raymond
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 4834-2255 Wesbrook Mall, Vancouver, BC, Canada, V6T 1Z3.
| |
Collapse
|
160
|
Shigetomi E, Patel S, Khakh BS. Probing the Complexities of Astrocyte Calcium Signaling. Trends Cell Biol 2016; 26:300-312. [PMID: 26896246 PMCID: PMC4946798 DOI: 10.1016/j.tcb.2016.01.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 01/08/2023]
Abstract
Astrocytes are abundant glial cells that tile the entire central nervous system and mediate well-established functions for neurons, blood vessels, and other glia. These ubiquitous cells display intracellular Ca(2+) signals, which have been intensely studied for 25 years. Recently, the use of improved methods has unearthed the panoply of astrocyte Ca(2+) signals and a variable landscape of basal Ca(2+) levels. In vivo studies have started to reveal the settings under which astrocytes display behaviorally relevant Ca(2+) signaling. Studies in mice have emphasized how astrocyte Ca(2+) signaling is altered in distinct neurodegenerative diseases. Progress in the past few years, fueled by methodological advances, has thus reignited interest in astrocyte Ca(2+) signaling for brain function and dysfunction.
Collapse
Affiliation(s)
- Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|