351
|
Hegeman DJ, Hong ES, Hernández VM, Chan CS. The external globus pallidus: progress and perspectives. Eur J Neurosci 2016; 43:1239-65. [PMID: 26841063 PMCID: PMC4874844 DOI: 10.1111/ejn.13196] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/20/2016] [Accepted: 01/27/2016] [Indexed: 12/12/2022]
Abstract
The external globus pallidus (GPe) of the basal ganglia is in a unique and powerful position to influence processing of motor information by virtue of its widespread projections to all basal ganglia nuclei. Despite the clinical importance of the GPe in common motor disorders such as Parkinson's disease, there is only limited information about its cellular composition and organizational principles. In this review, recent advances in the understanding of the diversity in the molecular profile, anatomy, physiology and corresponding behaviour during movement of GPe neurons are described. Importantly, this study attempts to build consensus and highlight commonalities of the cellular classification based on existing but contentious literature. Additionally, an analysis of the literature concerning the intricate reciprocal loops formed between the GPe and major synaptic partners, including both the striatum and the subthalamic nucleus, is provided. In conclusion, the GPe has emerged as a crucial node in the basal ganglia macrocircuit. While subtleties in the cellular makeup and synaptic connection of the GPe create new challenges, modern research tools have shown promise in untangling such complexity, and will provide better understanding of the roles of the GPe in encoding movements and their associated pathologies.
Collapse
Affiliation(s)
- Daniel J Hegeman
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Ellie S Hong
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Vivian M Hernández
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - C Savio Chan
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| |
Collapse
|
352
|
Oliveira AO, Osmand A, Outeiro TF, Muchowski PJ, Finkbeiner S. αB-Crystallin overexpression in astrocytes modulates the phenotype of the BACHD mouse model of Huntington's disease. Hum Mol Genet 2016; 25:1677-89. [PMID: 26920069 PMCID: PMC4986324 DOI: 10.1093/hmg/ddw028] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 02/01/2016] [Indexed: 11/14/2022] Open
Abstract
Huntington's disease (HD) is caused by an expanded polyglutamine (polyQ) tract in the huntingtin (htt) protein. The polyQ expansion increases the propensity of htt to aggregate and accumulate, and manipulations that mitigate protein misfolding or facilitate the clearance of misfolded proteins are predicted to slow disease progression in HD models. αB-crystallin (αBc) or HspB5 is a well-characterized member of the small heat shock protein (sHsp) family that reduces mutant htt (mhtt) aggregation and toxicity in vitro and in Drosophila models of HD. Here, we determined if overexpressing αBc in vivo modulates aggregation and delays the onset and progression of disease in a full-length model of HD, BACHD mice. Expression of sHsps in neurodegenerative disease predominantly occurs in non-neuronal cells, and in the brain, αBc is mainly found in astrocytes and oligodendrocytes. Here, we show that directed αBc overexpression in astrocytes improves motor performance in rotarod and balance beam tests and improves cognitive function in the BACHD mice. Improvement in behavioral deficits correlated with mitigation of neuropathological features commonly observed in HD. Interestingly, astrocytic αBc overexpression was neuroprotective against neuronal cell loss in BACHD brains, suggesting αBc might be acting in a non-cell-autonomous manner. At the protein level, αBc decreased the level of soluble mhtt and decreased the size of mhtt inclusions in BACHD brain. Our results support a model in which elevating astrocytic αBc confers neuroprotection through a potential non-cell-autonomous pathway that modulates mhtt aggregation and protein levels.
Collapse
Affiliation(s)
- Ana Osório Oliveira
- Lisbon Academic Medical Center PhD Program, Cell and Molecular Neuroscience Unit, Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal, Gladstone Institute for Neurological Disease, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Alexander Osmand
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Tiago Fleming Outeiro
- Cell and Molecular Neuroscience Unit, Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal, CEDOC-Chronic Diseases Research Center, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal, Department of Neurodegeneration and Restorative Research, University Medical Center Goettingen, Goettingen, Germany
| | | | - Steven Finkbeiner
- Gladstone Institute for Neurological Disease, J. David Gladstone Institutes, San Francisco, CA, USA, Department of Neurology, Department of Physiology, University of California at San Francisco, San Francisco, CA, USA and Taube/Koret Center for Neurodegenerative Disease Research, San Francisco, CA, USA
| |
Collapse
|
353
|
Real-time imaging of glutamate clearance reveals normal striatal uptake in Huntington disease mouse models. Nat Commun 2016; 7:11251. [PMID: 27052848 PMCID: PMC4829692 DOI: 10.1038/ncomms11251] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 03/07/2016] [Indexed: 12/17/2022] Open
Abstract
It has become well accepted that Huntington disease (HD) is associated with impaired glutamate uptake, resulting in a prolonged time-course of extracellular glutamate that contributes to excitotoxicity. However, the data supporting this view come largely from work in synaptosomes, which may overrepresent nerve-terminal uptake over astrocytic uptake. Here, we quantify real-time glutamate dynamics in HD mouse models by high-speed imaging of an intensity-based glutamate-sensing fluorescent reporter (iGluSnFR) and electrophysiological recordings of synaptically activated transporter currents in astrocytes. These techniques reveal a disconnect between the results obtained in synaptosomes and those in situ. Exogenous glutamate uptake is impaired in synaptosomes, whereas real-time measures of glutamate clearance in the HD striatum are normal or even accelerated, particularly in the aggressive R6/2 model. Our results highlight the importance of quantifying glutamate dynamics under endogenous release conditions, and suggest that the widely cited uptake impairment in HD does not contribute to pathogenesis. Huntington disease (HD) has been linked via biochemical uptake assays to impaired glutamate clearance and resultant excitotoxicity. Here, utilizing a fluorescent reporter, the authors measure real-time glutamate dynamics in mouse model HD brain slices and find normal or even accelerated glutamate clearance.
Collapse
|
354
|
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
|
355
|
Astrocyte scar formation aids central nervous system axon regeneration. Nature 2016; 532:195-200. [PMID: 27027288 DOI: 10.1038/nature17623] [Citation(s) in RCA: 1211] [Impact Index Per Article: 151.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/26/2016] [Indexed: 12/20/2022]
Abstract
Transected axons fail to regrow in the mature central nervous system. Astrocytic scars are widely regarded as causal in this failure. Here, using three genetically targeted loss-of-function manipulations in adult mice, we show that preventing astrocyte scar formation, attenuating scar-forming astrocytes, or ablating chronic astrocytic scars all failed to result in spontaneous regrowth of transected corticospinal, sensory or serotonergic axons through severe spinal cord injury (SCI) lesions. By contrast, sustained local delivery via hydrogel depots of required axon-specific growth factors not present in SCI lesions, plus growth-activating priming injuries, stimulated robust, laminin-dependent sensory axon regrowth past scar-forming astrocytes and inhibitory molecules in SCI lesions. Preventing astrocytic scar formation significantly reduced this stimulated axon regrowth. RNA sequencing revealed that astrocytes and non-astrocyte cells in SCI lesions express multiple axon-growth-supporting molecules. Our findings show that contrary to the prevailing dogma, astrocyte scar formation aids rather than prevents central nervous system axon regeneration.
Collapse
|
356
|
Zhao B, Zhu J, Dai D, Xing J, He J, Fu Z, Zhang L, Li Z, Wang W. Differential dopaminergic regulation of inwardly rectifying potassium channel mediated subthreshold dynamics in striatal medium spiny neurons. Neuropharmacology 2016; 107:396-410. [PMID: 27018450 DOI: 10.1016/j.neuropharm.2016.03.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 03/09/2016] [Accepted: 03/22/2016] [Indexed: 11/29/2022]
Abstract
The dorsal striatum plays a key role in motor control and cognitive processes. Proper functioning of the striatum relies on the fine dynamic balance between the direct pathway projection medium spiny neurons (MSNs) that express D1 dopamine receptor (D1 MSNs) and indirect pathway projection MSNs that express D2 dopamine receptor (D2 MSNs). The inwardly rectifying K(+) channels (Kir), which express on both D1 and D2 MSNs, participate in the subthreshold dynamics including the membrane resonance and dendritic integration. However, it remains unclear whether dopamine differentially regulates Kir mediated subthreshold dynamics in two subtypes MSNs. Using transgenic mice that express either tdTomato in D1 MSNs or eGFP in D2 MSNs, we explored the Kir mediated subthreshold dynamics in D1 or D2 MSNs with whole cell patch clamp recording in acute brain slices. We found that D1 receptor agonist increased the Kir current while D2 receptor activation decreased the Kir conductance. The dopamine regulation of the Kir enhanced the resonant frequency and reduced the resonant impedance of D1 MSNs. The converse is ture for D2 MSNs. It also caused an opposing effect on dendritic integration between D1 and D2 MSNs, which can promote stability of the two pathways. The D1 receptor activation modulated Kir through cAMP-PKA signaling, whereas the D2 receptor modulated Kir through PLC-PKC signaling. Our findings demonstrated the differential dopaminergic regulation role of Kir, which mediates distinct subthreshold dynamics, and thus, contributes to the role of dopamine in fine tuning the balance of the striatal direct and indirect pathway activities.
Collapse
Affiliation(s)
- Bo Zhao
- Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China; Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an 710032, PR China; Department of Neurology, Anning Branch of Lanzhou General Hospital of Lanzhou Military Region, Lanzhou 730070, PR China
| | - Junling Zhu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China
| | - Dongqing Dai
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an 710032, PR China; Cadet Brigade, Fourth Military Medical University, Xi'an 710032, PR China
| | - Junling Xing
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an 710032, PR China
| | - Jiahou He
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an 710032, PR China; Cadet Brigade, Fourth Military Medical University, Xi'an 710032, PR China
| | - Zhanyan Fu
- Model System and Neurobiology Department, Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Lei Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Zhuyi Li
- Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China.
| | - Wenting Wang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an 710032, PR China.
| |
Collapse
|
357
|
Nuriya M, Hirase H. Involvement of astrocytes in neurovascular communication. PROGRESS IN BRAIN RESEARCH 2016; 225:41-62. [PMID: 27130410 DOI: 10.1016/bs.pbr.2016.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The vascular interface of the brain is distinct from that of the peripheral tissue in that astrocytes, the most numerous glial cell type in the gray matter, cover the vasculature with their endfeet. This morphological feature of the gliovascular junction has prompted neuroscientists to suggest possible functional roles of astrocytes including astrocytic modulation of the vasculature. Additionally, astrocytes develop an intricate morphology that intimately apposes neuronal synapses, making them an ideal cellular mediator of neurovascular coupling. In this article, we first introduce the classical anatomical and physiological findings that led to the proposal of various gliovascular interaction models. Next, we touch on the technological advances in the past few decades that enabled investigations and evaluations of neuro-glio-vascular interactions in situ. We then review recent experimental findings on the roles of astrocytes in neurovascular coupling from the viewpoints of intra- and intercellular signalings in astrocytes.
Collapse
Affiliation(s)
- M Nuriya
- Keio University, Shinjuku, Tokyo, Japan
| | - H Hirase
- RIKEN Brain Science Institute, Wako, Saitama, Japan.
| |
Collapse
|
358
|
Dallérac G, Rouach N. Astrocytes as new targets to improve cognitive functions. Prog Neurobiol 2016; 144:48-67. [PMID: 26969413 DOI: 10.1016/j.pneurobio.2016.01.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 01/07/2016] [Accepted: 01/24/2016] [Indexed: 01/09/2023]
Abstract
Astrocytes are now viewed as key elements of brain wiring as well as neuronal communication. Indeed, they not only bridge the gap between metabolic supplies by blood vessels and neurons, but also allow fine control of neurotransmission by providing appropriate signaling molecules and insulation through a tight enwrapping of synapses. Recognition that astroglia is essential to neuronal communication is nevertheless fairly recent and the large body of evidence dissecting such role has focused on the synaptic level by identifying neuro- and gliotransmitters uptaken and released at synaptic or extrasynaptic sites. Yet, more integrated research deciphering the impact of astroglial functions on neuronal network activity have led to the reasonable assumption that the role of astrocytes in supervising synaptic activity translates in influencing neuronal processing and cognitive functions. Several investigations using recent genetic tools now support this notion by showing that inactivating or boosting astroglial function directly affects cognitive abilities. Accordingly, brain diseases resulting in impaired cognitive functions have seen their physiopathological mechanisms revisited in light of this primary protagonist of brain processing. We here provide a review of the current knowledge on the role of astrocytes in cognition and in several brain diseases including neurodegenerative disorders, psychiatric illnesses, as well as other conditions such as epilepsy. Potential astroglial therapeutic targets are also discussed.
Collapse
Affiliation(s)
- Glenn Dallérac
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, Paris, France.
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, Paris, France.
| |
Collapse
|
359
|
Farmer WT, Abrahamsson T, Chierzi S, Lui C, Zaelzer C, Jones EV, Bally BP, Chen GG, Théroux JF, Peng J, Bourque CW, Charron F, Ernst C, Sjöström PJ, Murai KK. Neurons diversify astrocytes in the adult brain through sonic hedgehog signaling. Science 2016; 351:849-54. [PMID: 26912893 DOI: 10.1126/science.aab3103] [Citation(s) in RCA: 189] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Astrocytes are specialized and heterogeneous cells that contribute to central nervous system function and homeostasis. However, the mechanisms that create and maintain differences among astrocytes and allow them to fulfill particular physiological roles remain poorly defined. We reveal that neurons actively determine the features of astrocytes in the healthy adult brain and define a role for neuron-derived sonic hedgehog (Shh) in regulating the molecular and functional profile of astrocytes. Thus, the molecular and physiological program of astrocytes is not hardwired during development but, rather, depends on cues from neurons that drive and sustain their specialized properties.
Collapse
Affiliation(s)
- W Todd Farmer
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Therése Abrahamsson
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Sabrina Chierzi
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Christopher Lui
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Cristian Zaelzer
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Emma V Jones
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Blandine Ponroy Bally
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Gary G Chen
- Department of Psychiatry, McGill University, Montreal, Quebec, Canada. McGill Group for Suicide Studies, Douglas Hospital, Montreal, Quebec, Canada
| | - Jean-Francois Théroux
- Department of Psychiatry, McGill University, Montreal, Quebec, Canada. McGill Group for Suicide Studies, Douglas Hospital, Montreal, Quebec, Canada
| | - Jimmy Peng
- Molecular Biology of Neural Development, Institut de Recherches Cliniques de Montréal, Department of Medicine, University of Montreal, Montreal, Quebec, Canada. Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Charles W Bourque
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Frédéric Charron
- Molecular Biology of Neural Development, Institut de Recherches Cliniques de Montréal, Department of Medicine, University of Montreal, Montreal, Quebec, Canada. Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Carl Ernst
- Department of Psychiatry, McGill University, Montreal, Quebec, Canada. McGill Group for Suicide Studies, Douglas Hospital, Montreal, Quebec, Canada. Department of Human Genetics, McGill University, Montreal, Quebec, Canada. Douglas Hospital Research Institute, Verdun, Quebec, Canada
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada.
| |
Collapse
|
360
|
Glial cell response after aneurysmal subarachnoid hemorrhage — Functional consequences and clinical implications. Biochim Biophys Acta Mol Basis Dis 2016; 1862:492-505. [DOI: 10.1016/j.bbadis.2015.10.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 12/17/2022]
|
361
|
Astrocytes: a central element in neurological diseases. Acta Neuropathol 2016; 131:323-45. [PMID: 26671410 DOI: 10.1007/s00401-015-1513-1] [Citation(s) in RCA: 536] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/28/2015] [Accepted: 11/21/2015] [Indexed: 12/18/2022]
Abstract
The neurone-centred view of the past disregarded or downplayed the role of astroglia as a primary component in the pathogenesis of neurological diseases. As this concept is changing, so is also the perceived role of astrocytes in the healthy and diseased brain and spinal cord. We have started to unravel the different signalling mechanisms that trigger specific molecular, morphological and functional changes in reactive astrocytes that are critical for repairing tissue and maintaining function in CNS pathologies, such as neurotrauma, stroke, or neurodegenerative diseases. An increasing body of evidence shows that the effects of astrogliosis on the neural tissue and its functions are not uniform or stereotypic, but vary in a context-specific manner from astrogliosis being an adaptive beneficial response under some circumstances to a maladaptive and deleterious process in another context. There is a growing support for the concept of astrocytopathies in which the disruption of normal astrocyte functions, astrodegeneration or dysfunctional/maladaptive astrogliosis are the primary cause or the main factor in neurological dysfunction and disease. This review describes the multiple roles of astrocytes in the healthy CNS, discusses the diversity of astroglial responses in neurological disorders and argues that targeting astrocytes may represent an effective therapeutic strategy for Alexander disease, neurotrauma, stroke, epilepsy and Alzheimer's disease as well as other neurodegenerative diseases.
Collapse
|
362
|
Akassoglou K, Agalliu D, Chang CJ, Davalos D, Grutzendler J, Hillman EMC, Khakh BS, Kleinfeld D, McGavern DB, Nelson SJ, Zlokovic BV. Neurovascular and Immuno-Imaging: From Mechanisms to Therapies. Proceedings of the Inaugural Symposium. Front Neurosci 2016; 10:46. [PMID: 26941593 PMCID: PMC4761864 DOI: 10.3389/fnins.2016.00046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 02/01/2016] [Indexed: 12/20/2022] Open
Abstract
Breakthrough advances in intravital imaging have launched a new era for the study of dynamic interactions at the neurovascular interface in health and disease. The first Neurovascular and Immuno-Imaging Symposium was held at the Gladstone Institutes, University of California, San Francisco in March, 2015. This highly interactive symposium brought together a group of leading researchers who discussed how recent studies have unraveled fundamental biological mechanisms in diverse scientific fields such as neuroscience, immunology, and vascular biology, both under physiological and pathological conditions. These Proceedings highlight how advances in imaging technologies and their applications revolutionized our understanding of the communication between brain, immune, and vascular systems and identified novel targets for therapeutic intervention in neurological diseases.
Collapse
Affiliation(s)
- Katerina Akassoglou
- Gladstone Institute of Neurological Disease, University of California, San FranciscoSan Francisco, CA, USA; Department of Neurology, University of California, San FranciscoSan Francisco, CA, USA
| | - Dritan Agalliu
- Departments of Neurology, Pathology and Cell Biology and Pharmacology, Columbia University Medical Center New York, NY, USA
| | - Christopher J Chang
- Departments of Chemistry and Molecular and Cell Biology, Howard Hughes Medical Institute, Helen Wills Neuroscience Institute, University of California, Berkeley Berkeley, CA, USA
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation Cleveland, OH, USA
| | | | - Elizabeth M C Hillman
- Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Kavli Institute for Brain Science, Columbia University New York, NY, USA
| | - Baljit S Khakh
- Departments of Neurobiology and Physiology, David Geffen School of Medicine, University of California, Los Angeles Los Angeles, CA, USA
| | - David Kleinfeld
- Department of Physics and Section of Neurobiology, University of California, San Diego La Jolla, CA, USA
| | - Dorian B McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
| | - Sarah J Nelson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco San Francisco, CA, USA
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California Los Angeles, CA, USA
| |
Collapse
|
363
|
Pardo L, Schlüter A, Valor LM, Barco A, Giralt M, Golbano A, Hidalgo J, Jia P, Zhao Z, Jové M, Portero-Otin M, Ruiz M, Giménez-Llort L, Masgrau R, Pujol A, Galea E. Targeted activation of CREB in reactive astrocytes is neuroprotective in focal acute cortical injury. Glia 2016; 64:853-74. [PMID: 26880229 DOI: 10.1002/glia.22969] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 01/07/2023]
Abstract
The clinical challenge in acute injury as in traumatic brain injury (TBI) is to halt the delayed neuronal loss that occurs hours and days after the insult. Here we report that the activation of CREB-dependent transcription in reactive astrocytes prevents secondary injury in cerebral cortex after experimental TBI. The study was performed in a novel bitransgenic mouse in which a constitutively active CREB, VP16-CREB, was targeted to astrocytes with the Tet-Off system. Using histochemistry, qPCR, and gene profiling we found less neuronal death and damage, reduced macrophage infiltration, preserved mitochondria, and rescued expression of genes related to mitochondrial metabolism in bitransgenic mice as compared to wild type littermates. Finally, with meta-analyses using publicly available databases we identified a core set of VP16-CREB candidate target genes that may account for the neuroprotective effect. Enhancing CREB activity in astrocytes thus emerges as a novel avenue in acute brain post-injury therapeutics.
Collapse
Affiliation(s)
- Luis Pardo
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, L'hospitalet De Llobregat, Barcelona, 08907, Spain
| | - Luis M Valor
- Instituto De Neurociencias De Alicante, Universidad Miguel Hernández/Consejo Superior De Investigaciones Científicas, Sant Joan D'alacant, Alicante, 03550, Spain
| | - Angel Barco
- Instituto De Neurociencias De Alicante, Universidad Miguel Hernández/Consejo Superior De Investigaciones Científicas, Sant Joan D'alacant, Alicante, 03550, Spain
| | - Mercedes Giralt
- Institut De Neurociències and Department of Cellular Biology, Physiology and Immunology, Faculty of Biosciences, Universitat Autònoma, Barcelona, 08193, Spain
| | - Arantxa Golbano
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Juan Hidalgo
- Institut De Neurociències and Department of Cellular Biology, Physiology and Immunology, Faculty of Biosciences, Universitat Autònoma, Barcelona, 08193, Spain
| | - Peilin Jia
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee.,Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Zhongming Zhao
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee.,Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mariona Jové
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, 25198, Spain
| | - Manuel Portero-Otin
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, 25198, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, L'hospitalet De Llobregat, Barcelona, 08907, Spain
| | - Lydia Giménez-Llort
- Institut De Neurociènces and Department of Psychiatry and Forensic Medicine, School of Medicine, Universitat Autònoma De Barcelona, Bellaterra, 08193, Spain
| | - Roser Masgrau
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, L'hospitalet De Llobregat, Barcelona, 08907, Spain.,Institució Catalana De Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| | - Elena Galea
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain.,Institució Catalana De Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| |
Collapse
|
364
|
Du Y, Kiyoshi CM, Wang Q, Wang W, Ma B, Alford CC, Zhong S, Wan Q, Chen H, Lloyd EE, Bryan RM, Zhou M. Genetic Deletion of TREK-1 or TWIK-1/TREK-1 Potassium Channels does not Alter the Basic Electrophysiological Properties of Mature Hippocampal Astrocytes In Situ. Front Cell Neurosci 2016; 10:13. [PMID: 26869883 PMCID: PMC4738265 DOI: 10.3389/fncel.2016.00013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/14/2016] [Indexed: 01/03/2023] Open
Abstract
We have recently shown that a linear current-to-voltage (I-V) relationship of membrane conductance (passive conductance) reflects the intrinsic property of K+ channels in mature astrocytes. While passive conductance is known to underpin a highly negative and stable membrane potential (VM) essential for the basic homeostatic function of astrocytes, a complete repertoire of the involved K+ channels remains elusive. TREK-1 two-pore domain K+ channel (K2P) is highly expressed in astrocytes, and covalent association of TREK-1 with TWIK-1, another highly expressed astrocytic K2P, has been reported as a mechanism underlying the trafficking of heterodimer TWIK-1/TREK-1 channel to the membrane and contributing to astrocyte passive conductance. To decipher the individual contribution of TREK-1 and address whether the appearance of passive conductance is conditional to the co-expression of TWIK-1/TREK-1 in astrocytes, TREK-1 single and TWIK-1/TREK-1 double gene knockout mice were used in the present study. The relative quantity of mRNA encoding other astrocyte K+ channels, such as Kir4.1, Kir5.1, and TREK-2, was not altered in these gene knockout mice. Whole-cell recording from hippocampal astrocytes in situ revealed no detectable changes in astrocyte passive conductance, VM, or membrane input resistance (Rin) in either kind of gene knockout mouse. Additionally, TREK-1 proteins were mainly located in the intracellular compartments of the hippocampus. Altogether, genetic deletion of TREK-1 alone or together with TWIK-1 produced no obvious alteration in the basic electrophysiological properties of hippocampal astrocytes. Thus, future research focusing on other K+ channels may shed light on this long-standing and important question in astrocyte physiology.
Collapse
Affiliation(s)
- Yixing Du
- Department of Neuroscience, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Department of Neurology, The First Affiliated Hospital of Nanjing Medical UniversityNanjing, China
| | - Conrad M Kiyoshi
- Department of Neuroscience, The Ohio State University Wexner Medical Center Columbus, OH, USA
| | - Qi Wang
- Department of Neuroscience, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Department of Neurology, Meitan General HospitalXibahe Nanli, Beijing, China
| | - Wei Wang
- Department of Physiology, Institute of Brain Research, School of Basic Medicine, Huazhong University of Science and Technology Wuhan, China
| | - Baofeng Ma
- Department of Neuroscience, The Ohio State University Wexner Medical Center Columbus, OH, USA
| | - Catherine C Alford
- Department of Neuroscience, The Ohio State University Wexner Medical Center Columbus, OH, USA
| | - Shiying Zhong
- Department of Neuroscience, The Ohio State University Wexner Medical Center Columbus, OH, USA
| | - Qi Wan
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University Nanjing, China
| | - Haijun Chen
- Department of Biological Science, University at Albany, State University of New York Albany, NY, USA
| | - Eric E Lloyd
- Department of Anesthesiology, Baylor College of Medicine Houston, TX, USA
| | - Robert M Bryan
- Department of Anesthesiology, Baylor College of Medicine Houston, TX, USA
| | - Min Zhou
- Department of Neuroscience, The Ohio State University Wexner Medical Center Columbus, OH, USA
| |
Collapse
|
365
|
Glial-endothelial crosstalk regulates blood–brain barrier function. Curr Opin Pharmacol 2016; 26:39-46. [DOI: 10.1016/j.coph.2015.09.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/23/2015] [Accepted: 09/27/2015] [Indexed: 12/21/2022]
|
366
|
Yao L, Gu X, Song Q, Wang X, Huang M, Hu M, Hou L, Kang T, Chen J, Chen H, Gao X. Nanoformulated alpha-mangostin ameliorates Alzheimer's disease neuropathology by elevating LDLR expression and accelerating amyloid-beta clearance. J Control Release 2016; 226:1-14. [PMID: 26836197 DOI: 10.1016/j.jconrel.2016.01.055] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD), the most common form of dementia, is now representing one of the largest global healthcare challenges. However, an effective therapy is still lacking. Accumulation of amyloid-beta (Aβ) in the brain is supposed to trigger pathogenic cascades that eventually lead to AD. Therefore, Aβ clearance strategy is being actively pursued as a promising disease modifying therapy. Here, we found that α-mangostin (α-M), a polyphenolic xanthone derivative from mangosteen, up-regulated low density lipoprotein receptor (LDLR) expression in microglia and liver cells, and efficiently facilitated Aβ clearance. However, the in vivo application of α-M is limited due to its hydrophobic nature, poor aqueous solubility and stability, and thus low bioavailability and accumulation in the target organs. To overcome this limitation, α-M was encapsulated into the core of poly(ethylene glycol)-poly(l-lactide) (PEG-PLA) nanoparticles [NP(α-M)]. Such nanoencapsulation improved the biodistribution of α-M in both the brain and liver, enhanced the brain clearance of (125)I-radiolabeled Aβ1-42 in an LDLR-dependent manner, reduced Aβ deposition, attenuated neuroinflammatory responses, ameliorated neurologic changes and reversed behavioral deficits in AD model mice. These findings justified the concept that polyphenol-mediated modulation of LDLR expression might serve as a safe and efficient disease-modifying therapy for AD by accelerating Aβ clearance. It also demonstrated the powerful capacity of nanotechnology in modulating the biodistribution behavior of drug to improve its therapeutic efficacy in AD.
Collapse
Affiliation(s)
- Lei Yao
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Xiao Gu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Qingxiang Song
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Xiaolin Wang
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Meng Huang
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Meng Hu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Lina Hou
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China
| | - Ting Kang
- Department of Pharmaceutics, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, PR China
| | - Jun Chen
- Department of Pharmaceutics, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, PR China
| | - Hongzhuan Chen
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China.
| | - Xiaoling Gao
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China.
| |
Collapse
|
367
|
Fisher SP, Schwartz MD, Wurts-Black S, Thomas AM, Chen TM, Miller MA, Palmerston JB, Kilduff TS, Morairty SR. Quantitative Electroencephalographic Analysis Provides an Early-Stage Indicator of Disease Onset and Progression in the zQ175 Knock-In Mouse Model of Huntington's Disease. Sleep 2016; 39:379-91. [PMID: 26446107 DOI: 10.5665/sleep.5448] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 09/05/2015] [Indexed: 01/09/2023] Open
Abstract
STUDY OBJECTIVES Patients with Huntington's disease (HD) show a high prevalence of sleep disorders that typically occur prior to the onset of motoric symptoms and neurodegeneration. Our understanding of the pathophysiological alterations in premanifest HD is limited, hindering the ability to measure disease modification in response to treatment. We used a full-length knock-in HD model to determine early changes in the electroencephalogram (EEG) and sleep that may predict the onset and progression of the disease. METHODS A 10-month longitudinal study was designed to determine the effect of the HD mutation on the EEG and sleep/wake changes in heterozygous (HET) and homozygous (HOM) zQ175 mice and wild-type (WT) littermates from 8 to 48 w of age. Mice were instrumented with tethered headmounts to record EEG/electromyography signals. Telemeters were implanted to continuously measure locomotor activity (LMA) and body temperature (Tb). Sleep deprivation (SDep) was performed at 8, 12, 16, 24, 32, and 48 w of age. RESULTS The HD mutation disrupted the EEG field potential from 8-12 w in an age- and mutant huntington dose-dependent manner, prior to changes in sleep/wake states, LMA, and Tb. Prominent effects of the HD mutation on the EEG included a progressive reduction in low frequency power, a slowing of rapid eye movement peak theta frequency, and the emergence of state-dependent beta/gamma oscillations. There was no effect of genotype on the relative increase in nonrapid eye movement delta power or sleep time in response to SDep. CONCLUSIONS The expression of the Huntington's disease (HD) mutation results in complex EEG alterations that occur prior to deficits in behavioral measures and are one of the earliest phenotypes uncovered in this mouse model. Despite these EEG changes, homeostatic responses to sleep loss were preserved in HET and HOM zQ175 mice. Greater insight into the localization and response of these EEG alterations to novel therapies may enable early intervention and improve outcomes for patients with HD.
Collapse
Affiliation(s)
- Simon P Fisher
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Michael D Schwartz
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Sarah Wurts-Black
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Alexia M Thomas
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Tsui-Ming Chen
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Michael A Miller
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Jeremiah B Palmerston
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| | - Stephen R Morairty
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California
| |
Collapse
|
368
|
New Insights on Astrocyte Ion Channels: Critical for Homeostasis and Neuron-Glia Signaling. J Neurosci 2016; 35:13827-35. [PMID: 26468182 DOI: 10.1523/jneurosci.2603-15.2015] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Initial biophysical studies on glial cells nearly 50 years ago identified these cells as being electrically silent. These first studies also demonstrated a large K(+) conductance, which led to the notion that glia may regulate extracellular K(+) levels homeostatically. This view has now gained critical support from the study of multiple disease models discussed herein. Dysfunction of a major astrocyte K(+) channel, Kir4.1, appears as an early pathological event underlying neuronal phenotypes in several neurodevelopmental and neurodegenerative diseases. An expanding list of other astrocyte ion channels, including the calcium-activated ion channel BEST-1, hemichannels, and two-pore domain K(+) channels, all contribute to astrocyte biology and CNS function and underpin new forms of crosstalk between neurons and glia. Once considered merely the glue that holds the brain together, it is now increasingly recognized that astrocytes contribute in several fundamental ways to neuronal function. Emerging new insights and future perspectives of this active research area are highlighted within. SIGNIFICANCE STATEMENT The critical role of astrocyte potassium channels in CNS homeostasis has been reemphasized by recent studies conducted in animal disease models. Emerging evidence also supports the signaling role mediated by astrocyte ion channels such as BEST1, hemichannels, and two-pore channels, which enable astrocytes to interact with neurons and regulate synaptic transmission and plasticity. This minisymposium highlights recent developments and future perspectives of these research areas.
Collapse
|
369
|
Dallérac GM, Cummings DM, Hirst MC, Milnerwood AJ, Murphy KPSJ. Changes in Dopamine Signalling Do Not Underlie Aberrant Hippocampal Plasticity in a Mouse Model of Huntington's Disease. Neuromolecular Med 2016; 18:146-53. [PMID: 26782175 DOI: 10.1007/s12017-016-8384-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/06/2016] [Indexed: 12/13/2022]
Abstract
Altered dopamine receptor labelling has been demonstrated in presymptomatic and symptomatic Huntington's disease (HD) gene carriers, indicating that alterations in dopaminergic signalling are an early event in HD. We have previously described early alterations in synaptic transmission and plasticity in both the cortex and hippocampus of the R6/1 mouse model of Huntington's disease. Deficits in cortical synaptic plasticity were associated with altered dopaminergic signalling and could be reversed by D1- or D2-like dopamine receptor activation. In light of these findings we here investigated whether defects in dopamine signalling could also contribute to the marked alteration in hippocampal synaptic function. To this end we performed dopamine receptor labelling and pharmacology in the R6/1 hippocampus and report a marked, age-dependent elevation of hippocampal D1 and D2 receptor labelling in R6/1 hippocampal subfields. Yet, pharmacological inhibition or activation of D1- or D2-like receptors did not modify the aberrant synaptic plasticity observed in R6/1 mice. These findings demonstrate that global perturbations to dopamine receptor expression do occur in HD transgenic mice, similarly in HD gene carriers and patients. However, the direction of change and the lack of effect of dopaminergic pharmacological agents on synaptic function demonstrate that the perturbations are heterogeneous and region-specific, a finding that may explain the mixed results of dopamine therapy in HD.
Collapse
Affiliation(s)
- Glenn M Dallérac
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK.
- CIRB, CNRS UMR 7241, INSERM U1050, Collège de France, 75005, Paris, France.
| | - Damian M Cummings
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK
- University College London, Neuroscience, Physiology and Pharmacology, Gower Street, London, WC1E 6BT, UK
| | - Mark C Hirst
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK
| | - Austen J Milnerwood
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK
- Department of Neurology & Centre for Applied Neurogenetics, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2255, Wesbrook Mall, Vancouver, V6T 1Z3, Canada
| | - Kerry P S J Murphy
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK.
| |
Collapse
|
370
|
Harada K, Kamiya T, Tsuboi T. Gliotransmitter Release from Astrocytes: Functional, Developmental, and Pathological Implications in the Brain. Front Neurosci 2016; 9:499. [PMID: 26793048 PMCID: PMC4709856 DOI: 10.3389/fnins.2015.00499] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 12/15/2015] [Indexed: 12/20/2022] Open
Abstract
Astrocytes comprise a large population of cells in the brain and are important partners to neighboring neurons, vascular cells, and other glial cells. Astrocytes not only form a scaffold for other cells, but also extend foot processes around the capillaries to maintain the blood–brain barrier. Thus, environmental chemicals that exist in the blood stream could have potentially harmful effects on the physiological function of astrocytes. Although astrocytes are not electrically excitable, they have been shown to function as active participants in the development of neural circuits and synaptic activity. Astrocytes respond to neurotransmitters and contribute to synaptic information processing by releasing chemical transmitters called “gliotransmitters.” State-of-the-art optical imaging techniques enable us to clarify how neurotransmitters elicit the release of various gliotransmitters, including glutamate, D-serine, and ATP. Moreover, recent studies have demonstrated that the disruption of gliotransmission results in neuronal dysfunction and abnormal behaviors in animal models. In this review, we focus on the latest technical approaches to clarify the molecular mechanisms of gliotransmitter exocytosis, and discuss the possibility that exposure to environmental chemicals could alter gliotransmission and cause neurodevelopmental disorders.
Collapse
Affiliation(s)
- Kazuki Harada
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo Tokyo, Japan
| | - Taichi Kamiya
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo Tokyo, Japan
| | - Takashi Tsuboi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo Tokyo, Japan
| |
Collapse
|
371
|
Verkhratsky A, Steardo L, Peng L, Parpura V. Astroglia, Glutamatergic Transmission and Psychiatric Diseases. ADVANCES IN NEUROBIOLOGY 2016; 13:307-326. [PMID: 27885635 DOI: 10.1007/978-3-319-45096-4_12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Astrocytes are primary homeostatic cells of the central nervous system. They regulate glutamatergic transmission through the removal of glutamate from the extracellular space and by supplying neurons with glutamine. Glutamatergic transmission is generally believed to be significantly impaired in the contexts of all major neuropsychiatric diseases. In most of these neuropsychiatric diseases, astrocytes show signs of degeneration and atrophy, which is likely to be translated into reduced homeostatic capabilities. Astroglial glutamate uptake/release and glutamate homeostasis are affected in all forms of major psychiatric disorders and represent a common mechanism underlying neurotransmission disbalance, aberrant connectome and overall failure on information processing by neuronal networks, which underlie pathogenesis of neuropsychiatric diseases.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, 48011, Spain.
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, 48940, Spain.
| | - Luca Steardo
- Department of Psychiatry, University of Naples SUN, Largo Madonna delle Grazie, Naples, Italy
| | - Liang Peng
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy & Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, 35294, USA
| |
Collapse
|
372
|
Weller J, Steinhäuser C, Seifert G. pH-Sensitive K+ Currents and Properties of K2P Channels in Murine Hippocampal Astrocytes. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:263-94. [DOI: 10.1016/bs.apcsb.2015.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
373
|
Kumar P, Kumar D, Jha SK, Jha NK, Ambasta RK. Ion Channels in Neurological Disorders. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:97-136. [DOI: 10.1016/bs.apcsb.2015.10.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
374
|
Verkhratsky A, Parpura V. Astrogliopathology in neurological, neurodevelopmental and psychiatric disorders. Neurobiol Dis 2016; 85:254-261. [PMID: 25843667 PMCID: PMC4592688 DOI: 10.1016/j.nbd.2015.03.025] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/20/2015] [Accepted: 03/26/2015] [Indexed: 12/17/2022] Open
Abstract
Astroglial cells represent a main element in the maintenance of homeostasis and providing defense to the brain. Consequently, their dysfunction underlies many, if not all, neurological, neurodevelopmental and neuropsychiatric disorders. General astrogliopathy is evident in diametrically opposing morpho-functional changes in astrocytes, i.e. their hypertrophy along with reactivity or atrophy with asthenia. Neurological disorders with astroglial participation can be genetic, of which Alexander disease is a primary sporadic astrogliopathy, environmentally caused, such as heavy metal encephalopathies, or neurodevelopmental in origin. Astroglia contribute to neurodegenerative processes seen in amyotrophic lateral sclerosis, Alzheimer's and Huntington's diseases. Furthermore, astroglia also play a role in major neuropsychiatric disorders, ranging from schizophrenia to depression, as well as in addictive disorders.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 429, Birmingham, AL 35294-0021, USA; Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia.
| |
Collapse
|
375
|
Verkhratsky A, Zorec R, Rodriguez JJ, Parpura V. PATHOBIOLOGY OF NEURODEGENERATION: THE ROLE FOR ASTROGLIA. OPERA MEDICA ET PHYSIOLOGICA 2016; 1:13-22. [PMID: 27308639 PMCID: PMC4905715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The common denominator of neurodegenerative diseases, which mainly affect humans, is the progressive death of neural cells resulting in neurological and cognitive deficits. Astroglial cells are the central elements of the homoeostasis, defence and regeneration of the central nervous system, and their malfunction or reactivity contribute to the pathophysiology of neurodegenerative diseases. Pathological remodelling of astroglia in neurodegenerative context is multifaceted. Both astroglial atrophy with a loss of function and astroglial reactivity have been identified in virtually all the forms of neurodegenerative disorders. Astroglia may represent a novel target for therapeutic strategies aimed at preventing and possibly curing neurodegenerative diseases.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK
- University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain & Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Robert Zorec
- University of Ljubljana, Institute of Pathophysiology, Laboratory of Neuroendocrinology and Molecular Cell Physiology, Zaloska cesta 4; SI-1000, Ljubljana, Slovenia
- Celica, BIOMEDICAL, Technology Park 24, 1000 Ljubljana, Slovenia
| | - Jose J. Rodriguez
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain & Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, 1719 6th Avenue South, CIRC 429, University of Alabama, Birmingham, AL 35294-0021, USA
| |
Collapse
|
376
|
Minkel HR, Anwer TZ, Arps KM, Brenner M, Olsen ML. Elevated GFAP induces astrocyte dysfunction in caudal brain regions: A potential mechanism for hindbrain involved symptoms in type II Alexander disease. Glia 2015; 63:2285-97. [PMID: 26190408 PMCID: PMC4555878 DOI: 10.1002/glia.22893] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 07/01/2015] [Indexed: 12/14/2022]
Abstract
Alexander Disease (AxD) is a "gliopathy" caused by toxic, dominant gain-of-function mutations in the glial fibrillary acidic protein (GFAP) gene. Two distinct types of AxD exist. Type I AxD affected individuals develop cerebral symptoms by 4 years of age and suffer from macrocephaly, seizures, and physical and mental delays. As detection and diagnosis have improved, approximately half of all AxD patients diagnosed have onset >4 years and brainstem/spinal cord involvement. Type II AxD patients experience ataxia, palatal myoclonus, dysphagia, and dysphonia. No study has examined a mechanistic link between the GFAP mutations and caudal symptoms present in type II AxD patients. We demonstrate that two key astrocytic functions, the ability to regulate extracellular glutamate and to take up K(+) via K+ channels, are compromised in hindbrain regions and spinal cord in AxD mice. Spinal cord astrocytes in AxD transgenic mice are depolarized relative to WT littermates, and have a three-fold reduction in Ba(2+) -sensitive Kir4.1 mediated currents and six-fold reduction in glutamate uptake currents. The loss of these two functions is due to significant decreases in Kir4.1 (>70%) and GLT-1 (>60%) protein expression. mRNA expression for KCNJ10 and SLC1A2, the genes that code for Kir4.1 and GLT-1, are significantly reduced by postnatal Day 7. Protein and mRNA reductions for Kir4.1 and GLT-1 are exacerbated in AxD models that demonstrate earlier accumulation of GFAP and increased Rosenthal fiber formation. These findings provide a mechanistic link between the GFAP mutations/overexpression and the symptoms in those affected with Type II AxD.
Collapse
Affiliation(s)
- Heather R Minkel
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Tooba Z Anwer
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kara M Arps
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael Brenner
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michelle L Olsen
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
377
|
In Vivo NMR Studies of the Brain with Hereditary or Acquired Metabolic Disorders. Neurochem Res 2015; 40:2647-85. [PMID: 26610379 DOI: 10.1007/s11064-015-1772-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 11/10/2015] [Accepted: 11/12/2015] [Indexed: 01/09/2023]
Abstract
Metabolic disorders, whether hereditary or acquired, affect the brain, and abnormalities of the brain are related to cellular integrity; particularly in regard to neurons and astrocytes as well as interactions between them. Metabolic disturbances lead to alterations in cellular function as well as microscopic and macroscopic structural changes in the brain with diabetes, the most typical example of metabolic disorders, and a number of hereditary metabolic disorders. Alternatively, cellular dysfunction and degeneration of the brain lead to metabolic disturbances in hereditary neurological disorders with neurodegeneration. Nuclear magnetic resonance (NMR) techniques allow us to assess a range of pathophysiological changes of the brain in vivo. For example, magnetic resonance spectroscopy detects alterations in brain metabolism and energetics. Physiological magnetic resonance imaging (MRI) detects accompanying changes in cerebral blood flow related to neurovascular coupling. Diffusion and T1/T2-weighted MRI detect microscopic and macroscopic changes of the brain structure. This review summarizes current NMR findings of functional, physiological and biochemical alterations within a number of hereditary and acquired metabolic disorders in both animal models and humans. The global view of the impact of these metabolic disorders on the brain may be useful in identifying the unique and/or general patterns of abnormalities in the living brain related to the pathophysiology of the diseases, and identifying future fields of inquiry.
Collapse
|
378
|
Ranjbar M, Amiri M. On the role of astrocyte analog circuit in neural frequency adaptation. Neural Comput Appl 2015. [DOI: 10.1007/s00521-015-2112-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
379
|
Zhu W, Mao Z, Zhu C, Li M, Cao C, Guan Y, Yuan J, Xie G, Guan X. Adolescent exposure to cocaine increases anxiety-like behavior and induces morphologic and neurochemical changes in the hippocampus of adult rats. Neuroscience 2015; 313:174-83. [PMID: 26621120 DOI: 10.1016/j.neuroscience.2015.11.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 10/24/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
Abstract
Repeated exposure to cocaine during adolescence may affect both physical and psychological conditions in the brain, and increase the risk of psychiatric disorders and addiction behaviors in adulthood. Adolescence represents a critical development period for the hippocampus. Moreover, different regions of the hippocampus are involved in different functions. Dorsal hippocampus (dHP) has been implicated in learning and memory, whereas ventral hippocampus (vHP) plays an important role in emotional processing. In this study, the rats that were exposed to cocaine during adolescence (postnatal days, P28-P42) showed higher anxiety-like behavior in the elevated plus maze test in adulthood (P80), but displayed normal spatial learning and memory in the Morris water maze test. Furthermore, repeated exposure to cocaine during adolescence lead to alterations in morphology of pyramidal neurons, activities of astrocytes, and levels of proteins that involved in synaptic transmission, apoptosis, inflammation and addiction in both dHP and vHP of adult rats. These findings suggest that repeated exposure to cocaine during adolescence in rats may elicit morphologic and neurochemical changes in the hippocampus when the animals reach adulthood. These changes may contribute to the increased susceptibility for psychiatric disorders and addiction seen in adults.
Collapse
Affiliation(s)
- W Zhu
- Department of Human Anatomy, Nanjing Medical University, Nanjing, China
| | - Z Mao
- Department of Human Anatomy, Nanjing Medical University, Nanjing, China
| | - C Zhu
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - M Li
- Department of Human Anatomy, Nanjing Medical University, Nanjing, China
| | - C Cao
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Y Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - J Yuan
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - G Xie
- Department of Human Anatomy, Nanjing Medical University, Nanjing, China
| | - X Guan
- Department of Human Anatomy, Nanjing Medical University, Nanjing, China.
| |
Collapse
|
380
|
Cell and Context-Dependent Effects of the Heat Shock Protein DNAJB6 on Neuronal Survival. Mol Neurobiol 2015; 53:5628-39. [PMID: 26476842 DOI: 10.1007/s12035-015-9452-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/21/2015] [Indexed: 10/22/2022]
Abstract
Previous studies performed in cell lines have shown that the heat shock protein, DNAJB6, protects against the proteotoxic effects of mutant huntingtin (mut-Htt) via direct interaction with mut-Htt. However, these studies were performed primarily using in vitro models and cell lines. We report that when expressed in primary neurons, DNAJB6 induces cell death. Neurotoxicity is observed with both the DNAJB6a isoform, which is strictly nuclear, and the DNAJB6b isoform, which is predominantly cytoplasmic, suggesting that neurotoxicity is mediated in the nucleus. However, when co-expressed in primary neurons with mut-Htt, DNAJB6 protects against mut-Htt neurotoxicity. This suggests that the contrasting effect of DNAJB6 on neuronal viability depends on the presence or absence of proteotoxic stress. Neurotoxicity of DNAJB6 cannot be prevented by inhibition of glycogen synthase kinase 3 beta (GSK3β) or c-Jun N-terminal kinase (JNK) but is prevented by pharmacological inhibition of cyclin-dependent kinases (CDKs). Expression of dominant-negative forms of CDK2 or CDK4, or of p21(CIP1), the physiological inhibitor of CDKs, also inhibits DNAJB6 neurotoxicity. DNAJB6 neurotoxicity can also be inhibited by histone deacetylase-4 (HDAC4), which interacts with DNAJB6 and which has previously been described to inhibit cell cycle progression. These results conclude that neurotoxicity resulting from elevated DNAJB6 is cell cycle dependent.
Collapse
|
381
|
Ma Q, Yang J, Li T, Milner TA, Hempstead BL. Selective reduction of striatal mature BDNF without induction of proBDNF in the zQ175 mouse model of Huntington's disease. Neurobiol Dis 2015; 82:466-477. [PMID: 26282324 PMCID: PMC4819334 DOI: 10.1016/j.nbd.2015.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 08/02/2015] [Accepted: 08/12/2015] [Indexed: 02/02/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder characterized by massive loss of medium spiny neurons in the striatum. However, the mechanisms by which mutant huntingtin leads to this selective neuronal death remain incompletely understood. Brain-derived neurotrophic factor (BDNF) has been shown to be neuroprotective on HD striatal neurons both in vitro and in vivo. ProBDNF, the precursor of mature BDNF (mBDNF), also can be secreted but promotes apoptosis of neurons expressing p75(NTR) and sortilin receptors. Although a reduction of total striatal BDNF protein has been reported in HD patients and mouse models, it remains unclear whether conversion of proBDNF to mBDNF is altered in HD, and whether the proBDNF receptors, p75(NTR) and sortilin are dysregulated, leading to impaired striatal neuron survival. To test these hypotheses, we generated bdnf-HA knock-in (KI) mice on the zQ175 HD background to accurately quantitate the levels of both proBDNF and mBDNF in the HD striatum. In aged zQ175 HD mice, we observed a significant loss of mBDNF and decreased TrkB activation, but no increase of proBDNF or p75(NTR) levels either in the sensorimotor cortex or the striatum. However, immunoreactivities of p75(NTR) and sortilin receptor are both increased in immature striatal oligodendrocytes, which associate with significant myelin defects in the HD striatum. Taken together, the present study indicates that diminished mature BDNF trophic signaling through the TrkB receptor, rather than an induction in proBDNF, is a main contributing factor to the vulnerability of striatal neurons in the zQ175 HD mouse model.
Collapse
Affiliation(s)
- Qian Ma
- Graduate Program of Neuroscience, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Jianmin Yang
- Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Thomas Li
- Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA; Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Barbara L Hempstead
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA; Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.
| |
Collapse
|
382
|
Developmental expression of Kir4.1 in astrocytes and oligodendrocytes of rat somatosensory cortex and hippocampus. Int J Dev Neurosci 2015; 47:198-205. [DOI: 10.1016/j.ijdevneu.2015.09.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 12/31/2022] Open
|
383
|
Zhang N, Bailus BJ, Ring KL, Ellerby LM. iPSC-based drug screening for Huntington's disease. Brain Res 2015; 1638:42-56. [PMID: 26428226 DOI: 10.1016/j.brainres.2015.09.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/16/2015] [Accepted: 09/18/2015] [Indexed: 01/29/2023]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, caused by an expansion of the CAG repeat in exon 1 of the huntingtin gene. The disease generally manifests in middle age with both physical and mental symptoms. There are no effective treatments or cures and death usually occurs 10-20 years after initial symptoms. Since the original identification of the Huntington disease associated gene, in 1993, a variety of models have been created and used to advance our understanding of HD. The most recent advances have utilized stem cell models derived from HD-patient induced pluripotent stem cells (iPSCs) offering a variety of screening and model options that were not previously available. The discovery and advancement of technology to make human iPSCs has allowed for a more thorough characterization of human HD on a cellular and developmental level. The interaction between the genome editing and the stem cell fields promises to further expand the variety of HD cellular models available for researchers. In this review, we will discuss the history of Huntington's disease models, common screening assays, currently available models and future directions for modeling HD using iPSCs-derived from HD patients. This article is part of a Special Issue entitled SI: PSC and the brain.
Collapse
Affiliation(s)
- Ningzhe Zhang
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States
| | - Barbara J Bailus
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States
| | - Karen L Ring
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States
| | - Lisa M Ellerby
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States.
| |
Collapse
|
384
|
Rivera-Aponte DE, Méndez-González MP, Rivera-Pagán AF, Kucheryavykh YV, Kucheryavykh LY, Skatchkov SN, Eaton MJ. Hyperglycemia reduces functional expression of astrocytic Kir4.1 channels and glial glutamate uptake. Neuroscience 2015; 310:216-23. [PMID: 26404875 DOI: 10.1016/j.neuroscience.2015.09.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/11/2015] [Accepted: 09/18/2015] [Indexed: 11/24/2022]
Abstract
Diabetics are at risk for a number of serious health complications including an increased incidence of epilepsy and poorer recovery after ischemic stroke. Astrocytes play a critical role in protecting neurons by maintaining extracellular homeostasis and preventing neurotoxicity through glutamate uptake and potassium buffering. These functions are aided by the presence of potassium channels, such as Kir4.1 inwardly rectifying potassium channels, in the membranes of astrocytic glial cells. The purpose of the present study was to determine if hyperglycemia alters Kir4.1 potassium channel expression and homeostatic functions of astrocytes. We used q-PCR, Western blot, patch-clamp electrophysiology studying voltage and potassium step responses and a colorimetric glutamate clearance assay to assess Kir4.1 channel levels and homeostatic functions of rat astrocytes grown in normal and high glucose conditions. We found that astrocytes grown in high glucose (25 mM) had an approximately 50% reduction in Kir4.1 mRNA and protein expression as compared with those grown in normal glucose (5mM). These reductions occurred within 4-7 days of exposure to hyperglycemia, whereas reversal occurred between 7 and 14 days after return to normal glucose. The decrease in functional Kir channels in the astrocytic membrane was confirmed using barium to block Kir channels. In the presence of 100-μM barium, the currents recorded from astrocytes in response to voltage steps were reduced by 45%. Furthermore, inward currents induced by stepping extracellular [K(+)]o from 3 to 10mM (reflecting potassium uptake) were 50% reduced in astrocytes grown in high glucose. In addition, glutamate clearance by astrocytes grown in high glucose was significantly impaired. Taken together, our results suggest that down-regulation of astrocytic Kir4.1 channels by elevated glucose may contribute to the underlying pathophysiology of diabetes-induced CNS disorders and contribute to the poor prognosis after stroke.
Collapse
Affiliation(s)
- D E Rivera-Aponte
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA.
| | - M P Méndez-González
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA.
| | - A F Rivera-Pagán
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA.
| | - Y V Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA.
| | - L Y Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA.
| | - S N Skatchkov
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA; Department of Physiology, Universidad Central del Caribe, Bayamón, PR, USA.
| | - M J Eaton
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR, USA.
| |
Collapse
|
385
|
A new minimally-invasive method for microinjection into the mouse spinal dorsal horn. Sci Rep 2015; 5:14306. [PMID: 26387932 PMCID: PMC4585681 DOI: 10.1038/srep14306] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/24/2015] [Indexed: 12/30/2022] Open
Abstract
Noninvasive gene delivery to the spinal dorsal horn (SDH) remains challenging because existing methods to directly microinject vectors require laminectomy, which leads to tissue damage and inflammation. Such responses might hamper accurate readouts of cellular and behavioural effects of an introduced gene. Here we develop a new minimally-invasive SDH microinjection technique without the need of laminectomy in which a microcapillary is inserted into the SDH parenchyma through an intervertebral space. Using this method, we microinjected adeno-associated virus with an astrocytic promoter into the SDH and achieved efficient gene expression in an astrocyte-specific manner without gliosis, neuronal loss or inflammation. Furthermore, astrocytic loss- and gain-of-function of the transcription factor STAT3 by expressing a dominant-negative form and a constitutive-active form of STAT3, respectively, demonstrated the necessity and sufficiency of astrocytic STAT3 in the maintenance of neuropathic pain following peripheral nerve injury, a debilitating chronic pain state in which currently available treatments are frequently ineffective. Thus, our technique enables manipulation of gene expression in cell type- and spatial-specific manners without adverse effects, and may be useful for research in SDH physiology and pathology.
Collapse
|
386
|
Diversity of astrocyte functions and phenotypes in neural circuits. Nat Neurosci 2015; 18:942-52. [PMID: 26108722 DOI: 10.1038/nn.4043] [Citation(s) in RCA: 752] [Impact Index Per Article: 83.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/04/2015] [Indexed: 12/11/2022]
Abstract
Astrocytes tile the entire CNS. They are vital for neural circuit function, but have traditionally been viewed as simple, homogenous cells that serve the same essential supportive roles everywhere. Here, we summarize breakthroughs that instead indicate that astrocytes represent a population of complex and functionally diverse cells. Physiological diversity of astrocytes is apparent between different brain circuits and microcircuits, and individual astrocytes display diverse signaling in subcellular compartments. With respect to injury and disease, astrocytes undergo diverse phenotypic changes that may be protective or causative with regard to pathology in a context-dependent manner. These new insights herald the concept that astrocytes represent a diverse population of genetically tractable cells that mediate neural circuit-specific roles in health and disease.
Collapse
|
387
|
Stout RF, Snapp EL, Spray DC. Connexin Type and Fluorescent Protein Fusion Tag Determine Structural Stability of Gap Junction Plaques. J Biol Chem 2015; 290:23497-514. [PMID: 26265468 DOI: 10.1074/jbc.m115.659979] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Indexed: 12/22/2022] Open
Abstract
Gap junctions (GJs) are made up of plaques of laterally clustered intercellular channels and the membranes in which the channels are embedded. Arrangement of channels within a plaque determines subcellular distribution of connexin binding partners and sites of intercellular signaling. Here, we report the discovery that some connexin types form plaque structures with strikingly different degrees of fluidity in the arrangement of the GJ channel subcomponents of the GJ plaque. We uncovered this property of GJs by applying fluorescence recovery after photobleaching to GJs formed from connexins fused with fluorescent protein tags. We found that connexin 26 (Cx26) and Cx30 GJs readily diffuse within the plaque structures, whereas Cx43 GJs remain persistently immobile for more than 2 min after bleaching. The cytoplasmic C terminus of Cx43 was required for stability of Cx43 plaque arrangement. We provide evidence that these qualitative differences in GJ arrangement stability reflect endogenous characteristics, with the caveat that the sizes of the GJs examined were necessarily large for these measurements. We also uncovered an unrecognized effect of non-monomerized fluorescent protein on the dynamically arranged GJs and the organization of plaques composed of multiple connexin types. Together, these findings redefine our understanding of the GJ plaque structure and should be considered in future studies using fluorescent protein tags to probe dynamics of highly ordered protein complexes.
Collapse
Affiliation(s)
- Randy F Stout
- From the Dominick P. Purpura Department of Neuroscience and
| | - Erik Lee Snapp
- the Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - David C Spray
- From the Dominick P. Purpura Department of Neuroscience and
| |
Collapse
|
388
|
Wunderlich KA, Tanimoto N, Grosche A, Zrenner E, Pekny M, Reichenbach A, Seeliger MW, Pannicke T, Perez MT. Retinal functional alterations in mice lacking intermediate filament proteins glial fibrillary acidic protein and vimentin. FASEB J 2015; 29:4815-28. [PMID: 26251181 DOI: 10.1096/fj.15-272963] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/27/2015] [Indexed: 01/02/2023]
Abstract
Vimentin (Vim) and glial fibrillary acidic protein (GFAP) are important components of the intermediate filament (IF) (or nanofilament) system of astroglial cells. We conducted full-field electroretinogram (ERG) recordings and found that whereas photoreceptor responses (a-wave) were normal in uninjured GFAP(-/-)Vim(-/-) mice, b-wave amplitudes were increased. Moreover, we found that Kir (inward rectifier K(+)) channel protein expression was reduced in the retinas of GFAP(-/-)Vim(-/-) mice and that Kir-mediated current amplitudes were lower in Müller glial cells isolated from these mice. Studies have shown that the IF system, in addition, is involved in the retinal response to injury and that attenuated Müller cell reactivity and reduced photoreceptor cell loss are observed in IF-deficient mice after experimental retinal detachment. We investigated whether the lack of IF proteins would affect cell survival in a retinal ischemia-reperfusion model. We found that although cell loss was induced in both genotypes, the number of surviving cells in the inner retina was lower in IF-deficient mice. Our findings thus show that the inability to produce GFAP and Vim affects normal retinal physiology and that the effect of IF deficiency on retinal cell survival differs, depending on the underlying pathologic condition.
Collapse
Affiliation(s)
- Kirsten A Wunderlich
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Naoyuki Tanimoto
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Antje Grosche
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Eberhart Zrenner
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Milos Pekny
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Andreas Reichenbach
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Mathias W Seeliger
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Pannicke
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Maria-Thereza Perez
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| |
Collapse
|
389
|
Illes P, Verkhratsky A. Purinergic neurone-glia signalling in cognitive-related pathologies. Neuropharmacology 2015; 104:62-75. [PMID: 26256423 DOI: 10.1016/j.neuropharm.2015.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/19/2015] [Accepted: 08/03/2015] [Indexed: 12/31/2022]
Abstract
Neuroglia, represented by astrocytes, oligodendrocytes, NG glia and microglia are homeostatic, myelinating and defensive cells of the brain. Neuroglial cells express various combinations of purinoceptors, which contribute to multiple intercellular signalling pathways in the healthy and diseased nervous system. Neurological diseases are invariably associated with profound neuroglial remodelling, which is manifest by reactive gliosis, pathological remodelling and functional atrophy of various types of glial cells. Gliopathology is disease and region specific and produces multiple glial phenotypes that may be neuroprotective or neurotoxic. In this review we summarise recent knowledge on the role of glial purinergic signalling in cognitive-related neurological diseases. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
Collapse
Affiliation(s)
- Peter Illes
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany.
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain; University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia.
| |
Collapse
|
390
|
Ben Haim L, Carrillo-de Sauvage MA, Ceyzériat K, Escartin C. Elusive roles for reactive astrocytes in neurodegenerative diseases. Front Cell Neurosci 2015; 9:278. [PMID: 26283915 PMCID: PMC4522610 DOI: 10.3389/fncel.2015.00278] [Citation(s) in RCA: 292] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/06/2015] [Indexed: 12/21/2022] Open
Abstract
Astrocytes play crucial roles in the brain and are involved in the neuroinflammatory response. They become reactive in response to virtually all pathological situations in the brain such as axotomy, ischemia, infection, and neurodegenerative diseases (ND). Astrocyte reactivity was originally characterized by morphological changes (hypertrophy, remodeling of processes) and the overexpression of the intermediate filament glial fibrillary acidic protein (GFAP). However, it is unclear how the normal supportive functions of astrocytes are altered by their reactive state. In ND, in which neuronal dysfunction and astrocyte reactivity take place over several years or decades, the issue is even more complex and highly debated, with several conflicting reports published recently. In this review, we discuss studies addressing the contribution of reactive astrocytes to ND. We describe the molecular triggers leading to astrocyte reactivity during ND, examine how some key astrocyte functions may be enhanced or altered during the disease process, and discuss how astrocyte reactivity may globally affect ND progression. Finally we will consider the anticipated developments in this important field. With this review, we aim to show that the detailed study of reactive astrocytes may open new perspectives for ND.
Collapse
Affiliation(s)
- Lucile Ben Haim
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| | - Maria-Angeles Carrillo-de Sauvage
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| | - Kelly Ceyzériat
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| | - Carole Escartin
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| |
Collapse
|
391
|
Abstract
Astrocytes form borders (glia limitans) that separate neural from non-neural tissue along perivascular spaces, meninges and tissue lesions in the CNS. Transgenic loss-of-function studies reveal that astrocyte borders and scars serve as functional barriers that restrict the entry of inflammatory cells into CNS parenchyma in health and disease. Astrocytes also have powerful pro-inflammatory potential. Thus, astrocytes are emerging as pivotal regulators of CNS inflammatory responses. This Review discusses evidence that astrocytes have crucial roles in attracting and restricting CNS inflammation, with important implications for diverse CNS disorders.
Collapse
Affiliation(s)
- Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
392
|
Crotti A, Glass CK. The choreography of neuroinflammation in Huntington's disease. Trends Immunol 2015; 36:364-73. [PMID: 26001312 PMCID: PMC4786070 DOI: 10.1016/j.it.2015.04.007] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/19/2015] [Accepted: 04/19/2015] [Indexed: 01/01/2023]
Abstract
Currently, the concept of 'neuroinflammation' includes inflammation associated with neurodegenerative diseases, in which there is little or no infiltration of blood-derived immune cells into the brain. The roles of brain-resident and peripheral immune cells in these inflammatory settings are poorly understood, and it is unclear whether neuroinflammation results from immune reaction to neuronal dysfunction/degeneration, and/or represents cell-autonomous phenotypes of dysfunctional immune cells. Here, we review recent studies examining these questions in the context of Huntington's disease (HD), where mutant Huntingtin (HTT) is expressed in both neurons and glia. Insights into the cellular and molecular mechanisms underlying neuroinflammation in HD may provide a better understanding of inflammation in more complex neurodegenerative disorders, and of the contribution of the neuroinflammatory component to neurodegenerative disease pathogenesis.
Collapse
Affiliation(s)
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California San Diego, CA, USA; Department of Medicine, University of California San Diego, CA, USA.
| |
Collapse
|
393
|
Mutant huntingtin downregulates myelin regulatory factor-mediated myelin gene expression and affects mature oligodendrocytes. Neuron 2015; 85:1212-26. [PMID: 25789755 DOI: 10.1016/j.neuron.2015.02.026] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 11/27/2014] [Accepted: 02/05/2015] [Indexed: 11/21/2022]
Abstract
Growing evidence indicates that non-neuronal mutant huntingtin toxicity plays an important role in Huntington's disease (HD); however, whether and how mutant huntingtin affects oligodendrocytes, which are vitally important for neural function and axonal integrity, remains unclear. We first verified the presence of mutant huntingtin in oligodendrocytes in HD140Q knockin mice. We then established transgenic mice (PLP-150Q) that selectively express mutant huntingtin in oligodendrocytes. PLP-150Q mice show progressive neurological symptoms and early death, as well as age-dependent demyelination and reduced expression of myelin genes that are downstream of myelin regulatory factor (MYRF or MRF), a transcriptional regulator that specifically activates and maintains the expression of myelin genes in mature oligodendrocytes. Consistently, mutant huntingtin binds abnormally to MYRF and affects its transcription activity. Our findings suggest that dysfunction of mature oligodendrocytes is involved in HD pathogenesis and may also make a good therapeutic target.
Collapse
|
394
|
Philips T, Rothstein JD, Pouladi MA. Preclinical models: needed in translation? A Pro/Con debate. Mov Disord 2015; 29:1391-6. [PMID: 25216370 DOI: 10.1002/mds.26010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 08/11/2014] [Indexed: 12/11/2022] Open
Abstract
The discovery of the causative mutations and many of the predisposing risk factors for neurodegenerative disorders such as Amyotrophic Lateral Sclerosis, Alzheimer's, Parkinson's, and Huntington's disease (HD), has led to the development of a large number of genetic animal models of disease. In the case of HD, for example, over 20 different transgenic rodent models have been generated. These models have been of immense value in providing novel insights into mechanisms of disease, with the promise of accelerating the development of therapies that can delay the onset or slow the progression of the disease. Yet, despite extensive use of such models, no effective treatment for HD has been developed. Here, we discuss the value of animal models, highlighting their strengths and shortcomings in the context of translational research for HD.
Collapse
Affiliation(s)
- Thomas Philips
- Johns Hopkins University, Brain Science Institute, Baltimore, Maryland, USA
| | | | | |
Collapse
|
395
|
Molofsky AV, Deneen B. Astrocyte development: A Guide for the Perplexed. Glia 2015; 63:1320-9. [PMID: 25963996 DOI: 10.1002/glia.22836] [Citation(s) in RCA: 205] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 03/26/2015] [Indexed: 01/09/2023]
Abstract
Astrocytes are the predominant cell type in the brain and perform key functions vital to CNS physiology, including blood brain barrier formation and maintenance, synaptogenesis, neurotransmission, and metabolic regulation. To fully understand the contributions of astrocytes to brain function, it will be important to bridge the existing gap between development and physiology. In this review, we provide an overview of Astrocyte development, including recent insights into molecular mechanisms of astrocyte specification, regional patterning and proliferation. This developmental perspective is complemented with recent findings that describe the functional maturation of astrocytes and their prospective diversity. Future progress in understanding Astrocyte development will depend on the development of astrocyte- stage specific markers and tools for manipulating astrocytes without affecting neuron production. Ultimately, a mechanistic approach to Astrocyte development will be crucial to developing new treatments for the many neurodevelopmental, neurodegenerative, neuroimmune, and neoplastic diseases involving astrocyte dysfunction.
Collapse
Affiliation(s)
- Anna Victoria Molofsky
- Department of Psychiatry, University of California-San Francisco, San Francisco, California
| | - Benjamin Deneen
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas
| |
Collapse
|
396
|
Cortical efferents lacking mutant huntingtin improve striatal neuronal activity and behavior in a conditional mouse model of Huntington's disease. J Neurosci 2015; 35:4440-51. [PMID: 25762686 DOI: 10.1523/jneurosci.2812-14.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Abnormal electrophysiological activity in the striatum, which receives dense innervation from the cerebral cortex, is believed to set the stage for the behavioral phenotype observed in Huntington's disease (HD), a neurodegenerative condition caused by mutation of the huntingtin (mhtt) protein. However, cortical involvement is far from clear. To determine whether abnormal striatal processing can be explained by mhtt alone (cell-autonomous model) or by mhtt in the corticostriatal projection cell-cell interaction model, we used BACHD/Emx1-Cre (BE) mice, a conditional HD model in which full-length mhtt is genetically reduced in cortical output neurons, including those that project to the striatum. Animals were assessed beginning at 20 weeks of age for at least the next 40 weeks, a range over which presymptomatic BACHD mice become symptomatic. Both open-field and nest-building behavior deteriorated progressively in BACHD mice relative to both BE and wild-type (WT) mice. Neuronal activity patterns in the dorsal striatum, which receives input from the primary motor cortex (M1), followed a similar age progression because BACHD activity changed more rapidly than either BE or WT mice. However, in the M1, BE neuronal activity differed significantly from both WT and BACHD. Although abnormal cortical activity in BE mice likely reflects input from mhtt-expressing afferents, including cortical interneurons, improvements in BE striatal activity and behavior suggest a critical role for mhtt in cortical output neurons in shaping the onset and progression of striatal dysfunction.
Collapse
|
397
|
Astrocyte physiopathology: At the crossroads of intercellular networking, inflammation and cell death. Prog Neurobiol 2015; 130:86-120. [PMID: 25930681 DOI: 10.1016/j.pneurobio.2015.04.003] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/15/2015] [Accepted: 04/20/2015] [Indexed: 12/11/2022]
Abstract
Recent breakthroughs in neuroscience have led to the awareness that we should revise our traditional mode of thinking and studying the CNS, i.e. by isolating the privileged network of "intelligent" synaptic contacts. We may instead need to contemplate all the variegate communications occurring between the different neural cell types, and centrally involving the astrocytes. Basically, it appears that a single astrocyte should be considered as a core that receives and integrates information from thousands of synapses, other glial cells and the blood vessels. In turn, it generates complex outputs that control the neural circuitry and coordinate it with the local microcirculation. Astrocytes thus emerge as the possible fulcrum of the functional homeostasis of the healthy CNS. Yet, evidence indicates that the bridging properties of the astrocytes can change in parallel with, or as a result of, the morphological, biochemical and functional alterations these cells undergo upon injury or disease. As a consequence, they have the potential to transform from supportive friends and interactive partners for neurons into noxious foes. In this review, we summarize the currently available knowledge on the contribution of astrocytes to the functioning of the CNS and what goes wrong in various pathological conditions, with a particular focus on Amyotrophic Lateral Sclerosis, Alzheimer's Disease and ischemia. The observations described convincingly demonstrate that the development and progression of several neurological disorders involve the de-regulation of a finely tuned interplay between multiple cell populations. Thus, it seems that a better understanding of the mechanisms governing the integrated communication and detrimental responses of the astrocytes as well as their impact towards the homeostasis and performance of the CNS is fundamental to open novel therapeutic perspectives.
Collapse
|
398
|
Phatnani H, Maniatis T. Astrocytes in neurodegenerative disease. Cold Spring Harb Perspect Biol 2015; 7:cshperspect.a020628. [PMID: 25877220 DOI: 10.1101/cshperspect.a020628] [Citation(s) in RCA: 269] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Astrocytes contribute to the maintenance of the health and function of the central nervous system (CNS). Thus, it is not surprising that these multifunctional cells have been implicated in the onset and progression of several neurodegenerative diseases. The involvement of astrocytes in the neuropathology of these diseases is likely a consequence of both the loss of normal homeostatic functions and gain of toxic functions. Intracellular aggregates in astrocytes are a common feature of various neurodegenerative diseases, and these aggregates perturb normal astrocytic functions in ways that can be harmful to neuronal viability. Here, we review the role of astrocytes in neurodegenerative diseases, focusing on their dysfunction in Huntington's disease (HD), Parkinson's disease (PD), Alzheimer's disease (AD), and amyotrophic lateral sclerosis (ALS).
Collapse
Affiliation(s)
- Hemali Phatnani
- Columbia University Medical Center, Department of Biochemistry and Molecular Biophysics, New York, New York 10032
| | - Tom Maniatis
- Columbia University Medical Center, Department of Biochemistry and Molecular Biophysics, New York, New York 10032
| |
Collapse
|
399
|
The JAK/STAT3 pathway is a common inducer of astrocyte reactivity in Alzheimer's and Huntington's diseases. J Neurosci 2015; 35:2817-29. [PMID: 25673868 DOI: 10.1523/jneurosci.3516-14.2015] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Astrocyte reactivity is a hallmark of neurodegenerative diseases (ND), but its effects on disease outcomes remain highly debated. Elucidation of the signaling cascades inducing reactivity in astrocytes during ND would help characterize the function of these cells and identify novel molecular targets to modulate disease progression. The Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway is associated with reactive astrocytes in models of acute injury, but it is unknown whether this pathway is directly responsible for astrocyte reactivity in progressive pathological conditions such as ND. In this study, we examined whether the JAK/STAT3 pathway promotes astrocyte reactivity in several animal models of ND. The JAK/STAT3 pathway was activated in reactive astrocytes in two transgenic mouse models of Alzheimer's disease and in a mouse and a nonhuman primate lentiviral vector-based model of Huntington's disease (HD). To determine whether this cascade was instrumental for astrocyte reactivity, we used a lentiviral vector that specifically targets astrocytes in vivo to overexpress the endogenous inhibitor of the JAK/STAT3 pathway [suppressor of cytokine signaling 3 (SOCS3)]. SOCS3 significantly inhibited this pathway in astrocytes, prevented astrocyte reactivity, and decreased microglial activation in models of both diseases. Inhibition of the JAK/STAT3 pathway within reactive astrocytes also increased the number of huntingtin aggregates, a neuropathological hallmark of HD, but did not influence neuronal death. Our data demonstrate that the JAK/STAT3 pathway is a common mediator of astrocyte reactivity that is highly conserved between disease states, species, and brain regions. This universal signaling cascade represents a potent target to study the role of reactive astrocytes in ND.
Collapse
|
400
|
Pearce MM, Spartz EJ, Hong W, Luo L, Kopito RR. Prion-like transmission of neuronal huntingtin aggregates to phagocytic glia in the Drosophila brain. Nat Commun 2015; 6:6768. [PMID: 25866135 PMCID: PMC4515032 DOI: 10.1038/ncomms7768] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 02/24/2015] [Indexed: 12/12/2022] Open
Abstract
The brain has a limited capacity to self-protect against protein aggregate-associated pathology, and mounting evidence supports a role for phagocytic glia in this process. We have established a Drosophila model to investigate the role of phagocytic glia in clearance of neuronal mutant huntingtin (Htt) aggregates associated with Huntington disease. We find that glia regulate steady-state numbers of Htt aggregates expressed in neurons through a clearance mechanism that requires the glial scavenger receptor Draper and downstream phagocytic engulfment machinery. Remarkably, some of these engulfed neuronal Htt aggregates effect prion-like conversion of soluble, wild-type Htt in the glial cytoplasm. We provide genetic evidence that this conversion depends strictly on the Draper signalling pathway, unveiling a previously unanticipated role for phagocytosis in transfer of pathogenic protein aggregates in an intact brain. These results suggest a potential mechanism by which phagocytic glia contribute to both protein aggregate-related neuroprotection and pathogenesis in neurodegenerative disease.
Collapse
Affiliation(s)
| | - Ellen J. Spartz
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Weizhe Hong
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Liqun Luo
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Ron R. Kopito
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|