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Sun L, Zheng X, Che Y, Zhang Y, Huang Z, Jia L, Zhu Y, Lei W, Guo G, Shao C. Morphological changes in perisynaptic astrocytes induced by dopamine neuronal degeneration in the striatum of rats. Heliyon 2024; 10:e27637. [PMID: 38510046 PMCID: PMC10950654 DOI: 10.1016/j.heliyon.2024.e27637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024] Open
Abstract
Introduction The typical functionality of astrocytes was previously shown to be disrupted by Parkinson's disease (PD), which actively regulates synaptic neurotransmission. However, the morphological changes in astrocytes wrapping glutamatergic synapses in the striatum after dopamine (DA) neuronal degeneration is unclear. Methods We utilized a range of methodologies, encompassing the 6-hydroxydopamine (6OHDA)-induced PD model, as well as techniques such as immunohistochemistry, Western blotting, immunofluorescence and immunoelectron microscopy (IEM) to delve into the consequences of DA neuronal degeneration on the morphological attributes of perisynaptic astrocytes. Results Our findings demonstrated a notable rise in glial fibrillary acidic protein (GFAP) + astrocyte density and an upregulation in GFAP protein expression within the striatum due to DA neuronal degeneration, coincided with the enlargement, elongation, and thickening of astrocyte protuberances. However, the expression levels of glutamate transporter 1 (GLT1) and glutamine synthetase (GS), which are related to glutamate-glutamine cycle, were significantly reduced. Double immunofluorescence and IEM results indicated that different proportions of vesicular glutamate transporter 1 (VGlut1)+ and vesicular glutamate transporter 2 (VGlut2) + terminals were wrapped by astrocytes. Additionally, DA neuronal degeneration increased the percentage and area of VGlut1+ and VGlut2+ terminals wrapped by GFAP + astrocytes in the striatum. Furthermore, we noted that DA neuronal degeneration increased the percentage of VGlut1+ and VGlut2+ axo-spinous synapses wrapped by astrocytes but had no effect on axo-dendritic synapses. Conclusion Hence, perisynaptic astrocytes wrapping striatal glutamatergic synapses exhibit substantial morphological and functional alterations following DA neuronal degeneration making them a potential target for therapeutic interventions in PD.
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Affiliation(s)
- Liping Sun
- Department of Pathology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xuefeng Zheng
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, China
| | - Yichen Che
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, China
| | - Ye Zhang
- School of Nursing, Sun Yat-Sen University, Guangzhou, China
| | - Ziyun Huang
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Linju Jia
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yaofeng Zhu
- Institute of Medicine, College of Medicine, Jishou University, Jishou, China
| | - Wanlong Lei
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Guoqing Guo
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, China
| | - Chunkui Shao
- Department of Pathology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Zhao C, Wang C, Zhang H, Yan W. A mini-review of the role of vesicular glutamate transporters in Parkinson's disease. Front Mol Neurosci 2023; 16:1118078. [PMID: 37251642 PMCID: PMC10211467 DOI: 10.3389/fnmol.2023.1118078] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/06/2023] [Indexed: 05/31/2023] Open
Abstract
Parkinson's disease (PD) is a common neurodegenerative disease implicated in multiple interacting neurotransmitter pathways. Glutamate is the central excitatory neurotransmitter in the brain and plays critical influence in the control of neuronal activity. Impaired Glutamate homeostasis has been shown to be closely associated with PD. Glutamate is synthesized in the cytoplasm and stored in synaptic vesicles by vesicular glutamate transporters (VGLUTs). Following its exocytotic release, Glutamate activates Glutamate receptors (GluRs) and mediates excitatory neurotransmission. While Glutamate is quickly removed by excitatory amino acid transporters (EAATs) to maintain its relatively low extracellular concentration and prevent excitotoxicity. The involvement of GluRs and EAATs in the pathophysiology of PD has been widely studied, but little is known about the role of VGLUTs in the PD. In this review, we highlight the role of VGLUTs in neurotransmitter and synaptic communication, as well as the massive alterations in Glutamate transmission and VGLUTs levels in PD. Among them, adaptive changes in the expression level and function of VGLUTs may exert a crucial role in excitatory damage in PD, and VGLUTs are considered as novel potential therapeutic targets for PD.
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Affiliation(s)
- Cheng Zhao
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Department of Urology, Xiangya Hospital, Central South University, Changsha, China
| | - Chunyu Wang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hainan Zhang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Weiqian Yan
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
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Inhibition of Vesicular Glutamate Transporters (VGLUTs) with Chicago Sky Blue 6B Before Focal Cerebral Ischemia Offers Neuroprotection. Mol Neurobiol 2023; 60:3130-3146. [PMID: 36802054 PMCID: PMC10122628 DOI: 10.1007/s12035-023-03259-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 02/07/2023] [Indexed: 02/21/2023]
Abstract
Brain ischemia is one of the leading causes of death and long-term disability in the world. Interruption of the blood supply to the brain is a direct stimulus for many pathological events. The massive vesicular release of glutamate (Glu) after ischemia onset induces excitotoxicity, which is a potent stress on neurons. Loading of presynaptic vesicles with Glu is the first step of glutamatergic neurotransmission. Vesicular glutamate transporters 1, 2, and 3 (VGLUT1, 2, and 3) are the main players involved in filling presynaptic vesicles with Glu. VGLUT1 and VGLUT2 are expressed mainly in glutamatergic neurons. Therefore, the possibility of pharmacological modulation to prevent ischemia-related brain damage is attractive. In this study, we aimed to determine the effect of focal cerebral ischemia on the spatiotemporal expression of VGLUT1 and VGLUT2 in rats. Next, we investigated the influence of VGLUT inhibition with Chicago Sky Blue 6B (CSB6B) on Glu release and stroke outcome. The effect of CSB6B pretreatment on infarct volume and neurological deficit was compared with a reference model of ischemic preconditioning. The results of this study indicate that ischemia upregulated the expression of VGLUT1 in the cerebral cortex and in the dorsal striatum 3 days after ischemia onset. The expression of VGLUT2 was elevated in the dorsal striatum and in the cerebral cortex 24 h and 3 days after ischemia, respectively. Microdialysis revealed that pretreatment with CSB6B significantly reduced the extracellular Glu concentration. Altogether, this study shows that inhibition of VGLUTs might be a promising therapeutic strategy for the future.
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Mackmull MT, Nagel L, Sesterhenn F, Muntel J, Grossbach J, Stalder P, Bruderer R, Reiter L, van de Berg WDJ, de Souza N, Beyer A, Picotti P. Global, in situ analysis of the structural proteome in individuals with Parkinson's disease to identify a new class of biomarker. Nat Struct Mol Biol 2022; 29:978-989. [PMID: 36224378 DOI: 10.1038/s41594-022-00837-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/18/2022] [Indexed: 12/23/2022]
Abstract
Parkinson's disease (PD) is a prevalent neurodegenerative disease for which robust biomarkers are needed. Because protein structure reflects function, we tested whether global, in situ analysis of protein structural changes provides insight into PD pathophysiology and could inform a new concept of structural disease biomarkers. Using limited proteolysis-mass spectrometry (LiP-MS), we identified 76 structurally altered proteins in cerebrospinal fluid (CSF) of individuals with PD relative to healthy donors. These proteins were enriched in processes misregulated in PD, and some proteins also showed structural changes in PD brain samples. CSF protein structural information outperformed abundance information in discriminating between healthy participants and those with PD and improved the discriminatory performance of CSF measures of the hallmark PD protein α-synuclein. We also present the first analysis of inter-individual variability of a structural proteome in healthy individuals, identifying biophysical features of variable protein regions. Although independent validation is needed, our data suggest that global analyses of the human structural proteome will guide the development of novel structural biomarkers of disease and enable hypothesis generation about underlying disease processes.
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Affiliation(s)
- Marie-Therese Mackmull
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Luise Nagel
- Cluster of Excellence Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Fabian Sesterhenn
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | - Jan Grossbach
- Cluster of Excellence Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Patrick Stalder
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | | | - Wilma D J van de Berg
- Amsterdam UMC location Vrije Universiteit Amsterdam, Section Clinical Neuroanatomy and Biobanking, Department Anatomy and Neurosciences, Amsterdam, the Netherlands.,Amsterdam Neuroscience, Neurodegeneration, Amsterdam, the Netherlands
| | - Natalie de Souza
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland.,Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland
| | - Andreas Beyer
- Cluster of Excellence Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany. .,Faculty of Medicine and University Hospital of Cologne, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany. .,Institute for Genetics, Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germany.
| | - Paola Picotti
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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Social defeat drives hyperexcitation of the piriform cortex to induce learning and memory impairment but not mood-related disorders in mice. Transl Psychiatry 2022; 12:380. [PMID: 36088395 PMCID: PMC9464232 DOI: 10.1038/s41398-022-02151-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/27/2022] [Accepted: 09/02/2022] [Indexed: 12/05/2022] Open
Abstract
Clinical studies have shown that social defeat is an important cause of mood-related disorders, accompanied by learning and memory impairment in humans. The mechanism of mood-related disorders has been widely studied. However, the specific neural network involved in learning and memory impairment caused by social defeat remains unclear. In this study, behavioral test results showed that the mice induced both learning and memory impairments and mood-related disorders after exposure to chronic social defeat stress (CSDS). c-Fos immunofluorescence and fiber photometry recording confirmed that CaMKIIα expressing neurons of the piriform cortex (PC) were selectively activated by exposure to CSDS. Next, chemogenetics and optogenetics were performed to activate PC CaMKIIα expressing neurons, which showed learning and memory impairment but not mood-related disorders. Furthermore, chemogenetic inhibition of PC CaMKIIα expressing neurons significantly alleviated learning and memory impairment induced by exposure to CSDS but did not relieve mood-related disorders. Therefore, our data suggest that the overactivation of PC CaMKIIα expressing neurons mediates CSDS-induced learning and memory impairment, but not mood-related disorders, and provides a potential therapeutic target for learning and memory impairment induced by social defeat.
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Villalba RM, Behnke JA, Pare JF, Smith Y. Comparative Ultrastructural Analysis of Thalamocortical Innervation of the Primary Motor Cortex and Supplementary Motor Area in Control and MPTP-Treated Parkinsonian Monkeys. Cereb Cortex 2021; 31:3408-3425. [PMID: 33676368 PMCID: PMC8599722 DOI: 10.1093/cercor/bhab020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/29/2020] [Accepted: 01/19/2021] [Indexed: 12/15/2022] Open
Abstract
The synaptic organization of thalamic inputs to motor cortices remains poorly understood in primates. Thus, we compared the regional and synaptic connections of vGluT2-positive thalamocortical glutamatergic terminals in the supplementary motor area (SMA) and the primary motor cortex (M1) between control and MPTP-treated parkinsonian monkeys. In controls, vGluT2-containing fibers and terminal-like profiles invaded layer II-III and Vb of M1 and SMA. A significant reduction of vGluT2 labeling was found in layer Vb, but not in layer II-III, of parkinsonian animals, suggesting a potential thalamic denervation of deep cortical layers in parkinsonism. There was a significant difference in the pattern of synaptic connectivity in layers II-III, but not in layer Vb, between M1 and SMA of control monkeys. However, this difference was abolished in parkinsonian animals. No major difference was found in the proportion of perforated versus macular post-synaptic densities at thalamocortical synapses between control and parkinsonian monkeys in both cortical regions, except for a slight increase in the prevalence of perforated axo-dendritic synapses in the SMA of parkinsonian monkeys. Our findings suggest that disruption of the thalamic innervation of M1 and SMA may underlie pathophysiological changes of the motor thalamocortical loop in the state of parkinsonism.
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Affiliation(s)
- Rosa M Villalba
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
| | - Joseph A Behnke
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
| | - Jean-Francois Pare
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
| | - Yoland Smith
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
- Department of Neurology, School of Medicine, Emory University, Atlanta, GA 30329, USA
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Buck SA, De Miranda BR, Logan RW, Fish KN, Greenamyre JT, Freyberg Z. VGLUT2 Is a Determinant of Dopamine Neuron Resilience in a Rotenone Model of Dopamine Neurodegeneration. J Neurosci 2021; 41:4937-4947. [PMID: 33893220 PMCID: PMC8260163 DOI: 10.1523/jneurosci.2770-20.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease (PD) is characterized by progressive dopamine (DA) neuron loss in the SNc. In contrast, DA neurons in the VTA are relatively protected from neurodegeneration, but the underlying mechanisms for this resilience remain poorly understood. Recent work suggests that expression of the vesicular glutamate transporter 2 (VGLUT2) selectively impacts midbrain DA neuron vulnerability. We investigated whether altered DA neuron VGLUT2 expression determines neuronal resilience in rats exposed to rotenone, a mitochondrial complex I inhibitor and toxicant model of PD. We discovered that VTA/SNc DA neurons that expressed VGLUT2 are more resilient to rotenone-induced DA neurodegeneration. Surprisingly, the density of neurons with detectable VGLUT2 expression in the VTA and SNc increases in response to rotenone. Furthermore, dopaminergic terminals within the NAc, where the majority of VGLUT2-expressing DA neurons project, exhibit greater resilience compared with DA terminals in the caudate/putamen. More broadly, VGLUT2-expressing terminals are protected throughout the striatum from rotenone-induced degeneration. Together, our data demonstrate that a distinct subpopulation of VGLUT2-expressing DA neurons are relatively protected from rotenone neurotoxicity. Rotenone-induced upregulation of the glutamatergic machinery in VTA and SNc neurons and their projections may be part of a broader neuroprotective mechanism. These findings offer a putative new target for neuronal resilience that can be manipulated to prevent toxicant-induced DA neurodegeneration in PD.SIGNIFICANCE STATEMENT Environmental exposures to pesticides contribute significantly to pathologic processes that culminate in Parkinson's disease (PD). The pesticide rotenone has been used to generate a PD model that replicates key features of the illness, including dopamine neurodegeneration. To date, longstanding questions remain: are there dopamine neuron subpopulations resilient to rotenone; and if so, what are the molecular determinants of this resilience? Here we show that the subpopulation of midbrain dopaminergic neurons that express the vesicular glutamate transporter 2 (VGLUT2) are more resilient to rotenone-induced neurodegeneration. Rotenone also upregulates VGLUT2 more broadly in the midbrain, suggesting that VGLUT2 expression generally confers increased resilience to rotenone. VGLUT2 may therefore be a new target for boosting neuronal resilience to prevent toxicant-induced DA neurodegeneration in PD.
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Affiliation(s)
- Silas A Buck
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Briana R De Miranda
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Ryan W Logan
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, 02118
- Center for Systems Neurogenetics of Addiction, The Jackson Laboratory, Bar Harbor, Maine, 04609
| | - Kenneth N Fish
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - J Timothy Greenamyre
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
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Zhang Z, Zhou Y, Zhao H, Xu J, Yang X. Association Between Pathophysiological Mechanisms of Diabetic Retinopathy and Parkinson's Disease. Cell Mol Neurobiol 2020; 42:665-675. [PMID: 32880791 DOI: 10.1007/s10571-020-00953-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/22/2020] [Indexed: 11/27/2022]
Abstract
Diabetic retinopathy, the most common complication of diabetes, is a neurodegenerative disease in the eye. And Parkinson's disease, affecting the health of 1-2% of people over 60 years old throughout the world, is the second largest neurodegenerative disease in the brain. As the understanding of diabetic retinopathy and Parkinson's disease deepens, the two diseases are found to show correlation in incidence, similarity in clinical presentation, and close association in pathophysiological mechanisms. To reveal the association between pathophysiological mechanisms of the two disease, in this review, the shared pathophysiological factors of diabetic retinopathy and Parkinson's disease are summarized and classified into dopaminergic system, circadian rhythm, neurotrophic factors, α-synuclein, and Wnt signaling pathways. Furthermore, similar and different mechanisms so far as the shared pathophysiological factors of the two disorders are discussed systematically. Finally, a brief summary and new perspectives are presented to provide new directions for further efforts on the association, exploration, and clinical prevention and treatment of diabetic retinopathy and Parkinson's disease.
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Affiliation(s)
- Zhuoqing Zhang
- Department of Ophthalmology, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, China
- Department of Ophthalmology, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Yikun Zhou
- Department of Endocrinology, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Haiyan Zhao
- Department of Ophthalmology, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, China
- Department of Ophthalmology, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Jinghui Xu
- Department of Ophthalmology, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, China
- Department of Ophthalmology, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Xiaochun Yang
- Department of Ophthalmology, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, China.
- Department of Ophthalmology, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China.
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Dopamine receptor cooperativity synergistically drives dyskinesia, motor behavior, and striatal GABA neurotransmission in hemiparkinsonian rats. Neuropharmacology 2020; 174:108138. [DOI: 10.1016/j.neuropharm.2020.108138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/21/2020] [Accepted: 05/13/2020] [Indexed: 12/29/2022]
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Abstract
Background:Tics, defined as quick, rapid, sudden, recurrent, non-rhythmic motor movements or vocalizations are required components of Tourette Syndrome (TS) - a complex disorder characterized by the presence of fluctuating, chronic motor and vocal tics, and the presence of co-existing neuropsychological problems. Despite many advances, the underlying pathophysiology of tics/TS remains unknown.Objective:To address a variety of controversies surrounding the pathophysiology of TS. More specifically: 1) the configuration of circuits likely involved; 2) the role of inhibitory influences on motor control; 3) the classification of tics as either goal-directed or habitual behaviors; 4) the potential anatomical site of origin, e.g. cortex, striatum, thalamus, cerebellum, or other(s); and 5) the role of specific neurotransmitters (dopamine, glutamate, GABA, and others) as possible mechanisms (Abstract figure).Methods:Existing evidence from current clinical, basic science, and animal model studies are reviewed to provide: 1) an expanded understanding of individual components and the complex integration of the Cortico-Basal Ganglia-Thalamo-Cortical (CBGTC) circuit - the pathway involved with motor control; and 2) scientific data directly addressing each of the aforementioned controversies regarding pathways, inhibition, classification, anatomy, and neurotransmitters.Conclusion:Until a definitive pathophysiological mechanism is identified, one functional approach is to consider that a disruption anywhere within CBGTC circuitry, or a brain region inputting to the motor circuit, can lead to an aberrant message arriving at the primary motor cortex and enabling a tic. Pharmacologic modulation may be therapeutically beneficial, even though it might not be directed toward the primary abnormality.
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Affiliation(s)
- Harvey S. Singer
- Department of Neurology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Farhan Augustine
- Department of Neurology, Johns Hopkins Hospital, Baltimore, MD, United States
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Du X, Li J, Li M, Yang X, Qi Z, Xu B, Liu W, Xu Z, Deng Y. Research progress on the role of type I vesicular glutamate transporter (VGLUT1) in nervous system diseases. Cell Biosci 2020; 10:26. [PMID: 32158532 PMCID: PMC7057577 DOI: 10.1186/s13578-020-00393-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/24/2020] [Indexed: 12/14/2022] Open
Abstract
Glutamate (Glu) is the predominant excitatory neurotransmitter in the central nervous system (CNS). Glutamatergic transmission is critical for controlling neuronal activity. In presynaptic neurons, Glu is stored in synaptic vesicles and released by stimulation. The homeostasis of glutamatergic system is maintained by a set of transporters in the membrane of synaptic vesicles. The family of vesicular Glu transporters in mammals is comprised of three highly homologous proteins: VGLUT1-3. Among them, VGLUT1 accounts for the largest proportion. However, most of the Glu is transported into the synaptic vesicles via the type 1 vesicle Glu transporter (VGLUT1). So, the expression of particular VGLUT1 is largely complementary with limited overlap and so far it is most specific markers for neurons that use Glu as neurotransmitter. Controlling the activity of VGLUT1 could potentially modulate the efficiency of excitatory neuro-transmission and change the filling level of synaptic vesicles. This review summarizes the recent knowledge concerning molecular and functional characteristic of VGLUT1, their development, contribution to a series of central nervous system and peripheral nervous system diseases such as learning and memory disorders, Alzheimer's disease, Parkinson's disease and sensitized nociception or pain pathology et al.
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Affiliation(s)
- Xianchao Du
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Jiashuo Li
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Minghui Li
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Xinxin Yang
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Zhipeng Qi
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Zhaofa Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
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Tan Y, Xu Y, Cheng C, Zheng C, Zeng W, Wang J, Zhang X, Yang X, Wang J, Yang X, Nie S, Cao X. LY354740 Reduces Extracellular Glutamate Concentration, Inhibits Phosphorylation of Fyn/NMDARs, and Expression of PLK2/pS129 α-Synuclein in Mice Treated With Acute or Sub-Acute MPTP. Front Pharmacol 2020; 11:183. [PMID: 32180729 PMCID: PMC7059821 DOI: 10.3389/fphar.2020.00183] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/10/2020] [Indexed: 12/13/2022] Open
Abstract
Glutamate overactivity in basal ganglia critically contributes to the exacerbation of dopaminergic neuron degeneration in Parkinson's disease (PD). Activation of group II metabotropic glutamate receptors (mGlu2/3 receptors), which can decrease excitatory glutamate neurotransmission, provides an opportunity to slow down the degeneration of the dopaminergic system. However, the roles of mGlu2/3 receptors in relation to PD pathology were partially recognized. By using mGlu2/3 receptors agonist (LY354740) and mGlu2/3 receptors antagonist (LY341495) in mice challenged with different cumulative doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), we demonstrated that systemic injection of LY354740 reduced the level of extracellular glutamate and the extent of nigro-striatal degeneration in both acute and sub-acute MPTP mice, while LY341495 amplified the lesions in sub-acute MPTP mice only. LY354740 treatment improved behavioral dysfunctions mainly in acute MPTP mice and LY341495 treatment seemed to aggravate motor deficits in sub-acute MPTP mice. In addition, ligands of mGlu2/3 receptors also influenced the total amount of glutamate and dopamine in brain tissue. Interestingly, compared with normal mice, MPTP-treated mice abnormally up-regulated the expression of polo-like kinase 2 (PLK2)/pS129 α-synuclein and phosphorylation of Fyn/N-methyl-D-aspartate receptor subunit 2A/2B (GluN2A/2B). Both acute and sub-acute MPTP mice treated with LY354740 dose-dependently reduced all the above abnormal expression. Compared with MPTP mice treated with vehicle, mice pretreated with LY341495 exhibited much higher expression of p-Fyn Tyr416/p-GluN2B Tyr1472 and PLK2/pS129 α-synuclein in sub-acute MPTP mice models. Thus, our current data indicated that mGlu2/3 receptors ligands could influence MPTP-induced toxicity, which supported a role for mGlu2/3 receptors in PD pathogenesis.
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Affiliation(s)
- Yang Tan
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chi Cheng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cong Zheng
- Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China
| | - Weiqi Zeng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ji Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoqian Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoman Yang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jialing Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaomei Yang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shuke Nie
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xuebing Cao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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13
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Villalba RM, Pare JF, Lee S, Lee S, Smith Y. Thalamic degeneration in MPTP-treated Parkinsonian monkeys: impact upon glutamatergic innervation of striatal cholinergic interneurons. Brain Struct Funct 2019; 224:3321-3338. [PMID: 31679085 PMCID: PMC6878768 DOI: 10.1007/s00429-019-01967-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/04/2019] [Indexed: 12/13/2022]
Abstract
In both Parkinson's disease (PD) patients and MPTP-treated non-human primates, there is a profound neuronal degeneration of the intralaminar centromedian/parafascicular (CM/Pf) thalamic complex. Although this thalamic pathology has long been established in PD (and other neurodegenerative disorders), the impact of CM/Pf cell loss on the integrity of the thalamo-striatal glutamatergic system and its regulatory functions upon striatal neurons remain unknown. In the striatum, cholinergic interneurons (ChIs) are important constituents of the striatal microcircuitry and represent one of the main targets of CM/Pf-striatal projections. Using light and electron microscopy approaches, we have analyzed the potential impact of CM/Pf neuronal loss on the anatomy of the synaptic connections between thalamic terminals (vGluT2-positive) and ChIs neurons in the striatum of parkinsonian monkeys treated chronically with MPTP. The following conclusions can be drawn from our observations: (1) as reported in PD patients, and in our previous monkey study, CM/Pf neurons undergo profound degeneration in monkeys chronically treated with low doses of MPTP. (2) In the caudate (head and body) nucleus of parkinsonian monkeys, there is an increased density of ChIs. (3) Despite the robust loss of CM/Pf neurons, no significant change was found in the density of thalamostriatal (vGluT2-positive) terminals, and in the prevalence of vGluT2-positive terminals in contact with ChIs in parkinsonian monkeys. These findings provide new information about the state of thalamic innervation of the striatum in parkinsonian monkeys with CM/Pf degeneration, and bring up an additional level of intricacy to the consequences of thalamic pathology upon the functional microcircuitry of the thalamostriatal system in parkinsonism. Future studies are needed to assess the importance of CM/Pf neuronal loss, and its potential consequences on the neuroplastic changes induced in the synaptic organization of the thalamostriatal system, in the development of early cognitive impairments in PD.
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Affiliation(s)
- Rosa M Villalba
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 303, USA.
- UDALL Center for Excellence for Parkinson's Disease, Emory University, Atlanta, GA, USA.
| | - Jean-Francois Pare
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 303, USA
- UDALL Center for Excellence for Parkinson's Disease, Emory University, Atlanta, GA, USA
| | - Solah Lee
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 303, USA
- UDALL Center for Excellence for Parkinson's Disease, Emory University, Atlanta, GA, USA
| | - Sol Lee
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 303, USA
- UDALL Center for Excellence for Parkinson's Disease, Emory University, Atlanta, GA, USA
| | - Yoland Smith
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA, 303, USA
- Department of Neurology, School of Medicine, Emory University, Atlanta, GA, USA
- UDALL Center for Excellence for Parkinson's Disease, Emory University, Atlanta, GA, USA
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14
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Abstract
Tics are sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations (phonic productions) that are commonly present in children and are required symptoms for the diagnosis of Tourette syndrome. Despite their frequency, the underlying pathophysiology of tics/Tourette syndrome remains unknown. In this review, we discuss a variety of controversies surrounding the pathophysiology of tics, including the following: Are tics voluntary or involuntary? What is the role of the premonitory urge? Are tics due to excess excitatory or deficient inhibition? Is it time to adopt the contemporary version of the cortico-basal ganglia-thalamocortical (CBGTC) circuit? and Do we know the primary abnormal neurotransmitter in Tourette syndrome? Data from convergent clinical and animal model studies support complex interactions among the various CBGTC sites and neurotransmitters. Advances are being made; however, numerous pathophysiologic questions persist.
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Affiliation(s)
- Harvey S Singer
- Department of Neurology, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Farhan Augustine
- Department of Neurology, Johns Hopkins Hospital, Baltimore, MD, USA
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