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Yang XM, Yu H, Li JX, Li N, Li C, Xu DH, Zhang H, Fang TH, Wang SJ, Yan PY, Han BB. Excitotoxic Storms of Ischemic Stroke: A Non-neuronal Perspective. Mol Neurobiol 2024:10.1007/s12035-024-04184-7. [PMID: 38662299 DOI: 10.1007/s12035-024-04184-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
Numerous neurological disorders share a fatal pathologic process known as glutamate excitotoxicity. Among which, ischemic stroke is the major cause of mortality and disability worldwide. For a long time, the main idea of developing anti-excitotoxic neuroprotective agents was to block glutamate receptors. Despite this, there has been little successful clinical translation to date. After decades of "neuron-centered" views, a growing number of studies have recently revealed the importance of non-neuronal cells. Glial cells, cerebral microvascular endothelial cells, blood cells, and so forth are extensively engaged in glutamate synthesis, release, reuptake, and metabolism. They also express functional glutamate receptors and can listen and respond for fast synaptic transmission. This broadens the thoughts of developing excitotoxicity antagonists. In this review, the critical contribution of non-neuronal cells in glutamate excitotoxicity during ischemic stroke will be emphasized in detail, and the latest research progress as well as corresponding therapeutic strategies will be updated at length, aiming to reconceptualize glutamate excitotoxicity in a non-neuronal perspective.
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Affiliation(s)
- Xiao-Man Yang
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, People's Republic of China
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China
| | - Hao Yu
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China
| | - Jia-Xin Li
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, People's Republic of China
| | - Na Li
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China
| | - Chong Li
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China
| | - Dong-Han Xu
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, People's Republic of China
| | - Hao Zhang
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, People's Republic of China
| | - Tian-He Fang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China
| | - Shi-Jun Wang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China.
| | - Pei-Yu Yan
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, People's Republic of China.
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, People's Republic of China.
- Zhuhai MUST Science and Technology Research Institute, Macau University of Science and Technology, Macau, People's Republic of China.
| | - Bing-Bing Han
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People's Republic of China.
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2
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Skoug C, Holm C, Duarte JMN. Hormone-sensitive lipase is localized at synapses and is necessary for normal memory functioning in mice. J Lipid Res 2022; 63:100195. [PMID: 35300984 PMCID: PMC9026619 DOI: 10.1016/j.jlr.2022.100195] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 02/21/2022] [Accepted: 03/03/2022] [Indexed: 10/31/2022] Open
Abstract
Hormone-sensitive lipase (HSL) is mainly present in adipose tissue where it hydrolyses diacylglycerol. Although expression of HSL has also been reported in the brain, its presence in different cellular compartments is uncertain, and its role in regulating brain lipid metabolism remains hitherto unexplored. We hypothesized HSL might play a role in regulating the availability of bioactive lipids necessary for neuronal function, and therefore investigated whether dampening HSL activity could lead to brain dysfunction. In mice, we found HSL protein and enzymatic activity throughout the brain, both localized within neurons and enriched in synapses. HSL-null mice were then analyzed using a battery of behavioral tests. Relative to wild-type littermates, HSL-null mice showed impaired short- and long-term memory, yet preserved exploratory behaviurs. Molecular analysis of the cortex and hippocampus showed increased expression of genes involved in glucose utilization in the hippocampus, but not cortex, of HSL-null mice compared to controls. Furthermore, lipidomics analyses indicated an impact of HSL deletion on the profile of bioactive lipids, including a decrease in endocannabinoids and eicosanoids that are known to modulate neuronal activity, cerebral blood flow, and inflammation processes. Accordingly, mild increases in the expression of pro-inflammatory cytokines in HSL mice compared to littermates were suggestive of low-grade inflammation. We conclude that HSL has a homeostatic role in maintaining pools of lipids required for normal brain function. It remains to be tested, however, whether the recruitment of HSL for the synthesis of these lipids occurs during increased neuronal activity, or whether HSL participates in neuroinflammatory responses.
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Affiliation(s)
- Cecilia Skoug
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Sweden; Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Sweden
| | - Cecilia Holm
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Sweden
| | - João M N Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Sweden; Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Sweden.
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3
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Mielnicka A, Michaluk P. Exocytosis in Astrocytes. Biomolecules 2021; 11:1367. [PMID: 34572580 PMCID: PMC8471187 DOI: 10.3390/biom11091367] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/10/2021] [Accepted: 09/14/2021] [Indexed: 12/17/2022] Open
Abstract
Until recently, astrocytes were thought to be a part of a simple "brain glue" providing only a supporting role for neurons. However, the discoveries of the last two decades have proven astrocytes to be dynamic partners participating in brain metabolism and actively influencing communication between neurons. The means of astrocyte-neuron communication are diverse, although regulated exocytosis has received the most attention but also caused the most debate. Similar to most of eukaryotic cells, astrocytes have a complex range of vesicular organelles which can undergo exocytosis as well as intricate molecular mechanisms that regulate this process. In this review, we focus on the components needed for regulated exocytosis to occur and summarise the knowledge about experimental evidence showing its presence in astrocytes.
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Affiliation(s)
| | - Piotr Michaluk
- BRAINCITY, Laboratory of Neurobiology, The Nencki Institute of Experimental Biology, PAS, 02-093 Warsaw, Poland;
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4
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Takata-Tsuji F, Chounlamountri N, Do LD, Philippot C, Novion Ducassou J, Couté Y, Ben Achour S, Honnorat J, Place C, Pascual O. Microglia modulate gliotransmission through the regulation of VAMP2 proteins in astrocytes. Glia 2020; 69:61-72. [PMID: 32633839 DOI: 10.1002/glia.23884] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
Vesicular release is one of the release mechanisms of various signaling molecules. In neurons, the molecular machinery involved in vesicular release has been designed through evolution to trigger fast and synchronous release of neurotransmitters. Similar machinery with a slower kinetic and a slightly different molecular assembly allows astrocytes to release various transmitters such as adenosine triphosphate (ATP), glutamate, and D-serine. Astrocytes are important modulators of neurotransmission through gliotransmitter release. We recently demonstrated that microglia, another type of glia, release ATP to modulate synaptic transmission using astrocytes as intermediate. We now report that microglia regulate astrocytic gliotransmission through the regulation of SNARE proteins in astrocytes. Indeed, we found that gliotransmission triggered by P2Y1 agonist is impaired in slices from transgenic mice devoid of microglia. Using total internal reflection fluorescence imaging, we found that the vesicular release of gliotransmitter by astrocytes was different in cultures lacking microglia compared to vesicular release in astrocytes cocultured with microglia. Quantification of the kinetic of vesicular release indicates that the overall release appears to be faster in pure astrocyte cultures with more vesicles close to the membrane when compared to astrocytes cocultured with microglia. Finally, biochemical investigation of SNARE protein expression indicates an upregulation of VAMP2 in absence of microglia. Altogether, these results indicate that microglia seems to be involved in the regulation of an astrocytic phenotype compatible with proper gliotransmission. The mechanisms described in this study could be of importance for central nervous system diseases where microglia are activated.
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Affiliation(s)
- Fuyuko Takata-Tsuji
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France.,Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Naura Chounlamountri
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
| | - Le-Duy Do
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
| | - Camille Philippot
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
| | | | - Yohann Couté
- Université Grenoble Alpes, CEA, INSERM, IRIG, BGE, Grenoble, France
| | - Sarrah Ben Achour
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, Paris, France
| | - Jérôme Honnorat
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France.,Centre maladies rares sur les syndromes neurologiques paranéoplasiques, hospices Civils de Lyon, Lyon, France
| | - Christophe Place
- ENS de Lyon, CNRS, Laboratoire de Physique, Université de Lyon, Lyon, France
| | - Olivier Pascual
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
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Adnan M, Islam W, Zhang J, Zheng W, Lu GD. Diverse Role of SNARE Protein Sec22 in Vesicle Trafficking, Membrane Fusion, and Autophagy. Cells 2019; 8:E337. [PMID: 30974782 PMCID: PMC6523435 DOI: 10.3390/cells8040337] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 04/02/2019] [Accepted: 04/05/2019] [Indexed: 01/09/2023] Open
Abstract
Protein synthesis begins at free ribosomes or ribosomes attached with the endoplasmic reticulum (ER). Newly synthesized proteins are transported to the plasma membrane for secretion through conventional or unconventional pathways. In conventional protein secretion, proteins are transported from the ER lumen to Golgi lumen and through various other compartments to be secreted at the plasma membrane, while unconventional protein secretion bypasses the Golgi apparatus. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) proteins are involved in cargo vesicle trafficking and membrane fusion. The ER localized vesicle associated SNARE (v-SNARE) protein Sec22 plays a major role during anterograde and retrograde transport by promoting efficient membrane fusion and assisting in the assembly of higher order complexes by homodimer formation. Sec22 is not only confined to ER-Golgi intermediate compartments (ERGIC) but also facilitates formation of contact sites between ER and plasma membranes. Sec22 mutation is responsible for the development of atherosclerosis and symptoms in the brain in Alzheimer's disease and aging in humans. In the fruit fly Drosophila melanogaster, Sec22 is essential for photoreceptor morphogenesis, the wingless signaling pathway, and normal ER, Golgi, and endosome morphology. In the plant Arabidopsis thaliana, it is involved in development, and in the nematode Caenorhabditis elegans, it is in involved in the RNA interference (RNAi) pathway. In filamentous fungi, it affects cell wall integrity, growth, reproduction, pathogenicity, regulation of reactive oxygen species (ROS), expression of extracellular enzymes, and transcriptional regulation of many development related genes. This review provides a detailed account of Sec22 function, summarizes its domain structure, discusses its genetic redundancy with Ykt6, discusses what is known about its localization to discrete membranes, its contributions in conventional and unconventional autophagy, and a variety of other roles across different cellular systems ranging from higher to lower eukaryotes, and highlights some of the surprises that have originated from research on Sec22.
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Affiliation(s)
- Muhammad Adnan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and Key Laboratory of Bio-pesticides and Chemical Biology Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Waqar Islam
- College of Geographical Sciences, Fujian Normal University, Fuzhou 350007, Fujian, China.
| | - Jing Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and Key Laboratory of Bio-pesticides and Chemical Biology Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and Key Laboratory of Bio-pesticides and Chemical Biology Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Guo-Dong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and Key Laboratory of Bio-pesticides and Chemical Biology Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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6
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Lizarbe B, Soares AF, Larsson S, Duarte JMN. Neurochemical Modifications in the Hippocampus, Cortex and Hypothalamus of Mice Exposed to Long-Term High-Fat Diet. Front Neurosci 2019; 12:985. [PMID: 30670942 PMCID: PMC6331468 DOI: 10.3389/fnins.2018.00985] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/10/2018] [Indexed: 11/13/2022] Open
Abstract
Metabolic syndrome and diabetes impact brain function and metabolism. While it is well established that rodents exposed to diets rich in saturated fat develop brain dysfunction, contrasting results abound in the literature, likely as result of exposure to different high-fat diet (HFD) compositions and for varied periods of time. In the present study, we investigated alterations of hippocampal-dependent spatial memory by measuring Y-maze spontaneous alternation, metabolic profiles of the hippocampus, cortex and hypothalamus by 1H magnetic resonance spectroscopy (MRS), and levels of proteins specific to synaptic and glial compartments in mice exposed for 6 months to different amounts of fat (10, 45, or 60% of total energy intake). Increasing the dietary amount of fat from 10 to 45% or 60% resulted in obesity accompanied by increased leptin, fasting blood glucose and insulin, and reduced glucose tolerance. In comparison to controls (10%-fat), only mice fed the 60%-fat diet showed increased fed glycemia, as well as plasma corticosterone that has a major impact on brain function. HFD-induced metabolic profile modifications measured by 1H MRS were observed across the three brain areas in mice exposed to 60%- but not 45%-fat diet, while both HFD groups displayed impaired hippocampal-dependent memory. HFD also affected systems involved in neuro- or gliotransmission in the hippocampus. Namely, relative to controls, 60%-fat-fed mice showed reduced SNAP-25, PSD-95 and syntaxin-4 immunoreactivity, while 45%-fat-fed mice showed reduced gephyrin and syntaxin-4 immunoreactivity. For both HFD levels, reductions of the vesicular glutamate transporter vGlut1 and levels of the vesicular GABA transporter were observed in the hippocampus and hypothalamus, relative to controls. Immunoreactivity against GFAP and/or Iba-1 in the hypothalamus was higher in mice exposed to HFD than controls, suggesting occurrence of gliosis. We conclude that different levels of dietary fat result in distinct neurochemical alterations in the brain.
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Affiliation(s)
- Blanca Lizarbe
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Instituto de Investigaciones Biomédicas "Alberto Sols", Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, Madrid, Spain
| | - Ana Francisca Soares
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sara Larsson
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - João M N Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Lund, Sweden
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7
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Madrigal MP, Portalés A, SanJuan MP, Jurado S. Postsynaptic SNARE Proteins: Role in Synaptic Transmission and Plasticity. Neuroscience 2018; 420:12-21. [PMID: 30458218 DOI: 10.1016/j.neuroscience.2018.11.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 10/03/2018] [Accepted: 11/10/2018] [Indexed: 12/30/2022]
Abstract
Soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins mediate membrane fusion events in eukaryotic cells. Traditionally recognized as major players in regulating presynaptic neurotransmitter release, accumulative evidence over recent years has identified several SNARE proteins implicated in important postsynaptic processes such as neurotransmitter receptor trafficking and synaptic plasticity. Here we analyze the emerging data revealing this novel functional dimension for SNAREs with a focus on the molecular specialization of vesicular recycling and fusion in dendrites compared to those at axon terminals and its impact in synaptic transmission and plasticity.
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Affiliation(s)
| | - Adrián Portalés
- Instituto de Neurociencias CSIC-UMH, 03550 San Juan de Alicante, Spain
| | | | - Sandra Jurado
- Instituto de Neurociencias CSIC-UMH, 03550 San Juan de Alicante, Spain.
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8
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Gan G, Zhang C. The precise subcellular localization of Dlg in the Drosophila larva body wall using improved pre-embedding immuno-EM. J Neurosci Res 2017; 96:467-480. [PMID: 29231975 DOI: 10.1002/jnr.24139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 12/21/2022]
Abstract
Discs-large (Dlg) plays important roles in nerve tissue and epithelial tissue in Drosophila. However, the precise positioning of Dlg in the neuromuscular junction remains to be confirmed using an optimized labeling method. In this study, we improved the method of pre-embedding immunogold electron microscopy without the osmic tetroxide procedure, and we found that Lowicryl K4 M resin and low temperature helped to preserve the authenticity of the labeling signal with relatively good contrast. Dlg was strongly expressed in the entire subsynaptic reticulum (SSR) membrane of type Ib boutons, expressed in parts of the SSR membrane of type Is boutons, weakly expressed in axon terminals and axons, and not expressed in pre- or postsynaptic membranes of type Is boutons. In muscle cells and stratum corneum cells, Dlg was expressed both in the cytoplasm and in organelles with biomembranes. The precise location of Dlg in SSR membranes, rather than in postsynaptic membranes, shows that Dlg, with its multiple domains, acts as a remote or indirect regulator in postsynaptic signal transduction.
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Affiliation(s)
- Guangming Gan
- Medical School Southeast University, Nanjing, China.,Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Southeast University, Nanjing, China
| | - Chenchen Zhang
- Medical School Southeast University, Nanjing, China.,Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Southeast University, Nanjing, China
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9
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Bohmbach K, Schwarz MK, Schoch S, Henneberger C. The structural and functional evidence for vesicular release from astrocytes in situ. Brain Res Bull 2017; 136:65-75. [PMID: 28122264 DOI: 10.1016/j.brainresbull.2017.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 12/31/2022]
Abstract
The concept of the tripartite synapse states that bi-directional signalling between perisynaptic astrocyte processes, presynaptic axonal boutons and postsynaptic neuronal structures defines the properties of synaptic information processing. Ca2+-dependent vesicular release from astrocytes, as one of the mechanisms of astrocyte-neuron communication, has attracted particular attention but has also been the subject of intense debate. In neurons, regulated vesicular release is a strongly coordinated process. It requires a complex release machinery comprised of many individual components ranging from vesicular neurotransmitter transporters and soluble NSF attachment protein receptors (SNARE) proteins to Ca2+-sensors and the proteins that spatially and temporally control exocytosis of synaptic vesicles. If astrocytes employ similar mechanisms to release neurotransmitters is less well understood. The aim of this review is therefore to discuss recent experimental evidence that sheds light on the central structural components responsible for vesicular release from astrocytes in situ.
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Affiliation(s)
- Kirsten Bohmbach
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.
| | - Martin K Schwarz
- Department of Epileptology, University of Bonn Medical School, Bonn, Germany
| | - Susanne Schoch
- Institute of Neuropathology, University of Bonn Medical School, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; Institute of Neurology, University College London, London, United Kingdom.
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10
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Soo Hoo L, Banna CD, Radeke CM, Sharma N, Albertolle ME, Low SH, Weimbs T, Vandenberg CA. The SNARE Protein Syntaxin 3 Confers Specificity for Polarized Axonal Trafficking in Neurons. PLoS One 2016; 11:e0163671. [PMID: 27662481 PMCID: PMC5035089 DOI: 10.1371/journal.pone.0163671] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/12/2016] [Indexed: 11/19/2022] Open
Abstract
Cell polarity and precise subcellular protein localization are pivotal to neuronal function. The SNARE machinery underlies intracellular membrane fusion events, but its role in neuronal polarity and selective protein targeting remain unclear. Here we report that syntaxin 3 is involved in orchestrating polarized trafficking in cultured rat hippocampal neurons. We show that syntaxin 3 localizes to the axonal plasma membrane, particularly to axonal tips, whereas syntaxin 4 localizes to the somatodendritic plasma membrane. Disruption of a conserved N-terminal targeting motif, which causes mislocalization of syntaxin 3, results in coincident mistargeting of the axonal cargos neuron-glia cell adhesion molecule (NgCAM) and neurexin, but not transferrin receptor, a somatodendritic cargo. Similarly, RNAi-mediated knockdown of endogenous syntaxin 3 leads to partial mistargeting of NgCAM, demonstrating that syntaxin 3 plays an important role in its targeting. Additionally, overexpression of syntaxin 3 results in increased axonal growth. Our findings suggest an important role for syntaxin 3 in maintaining neuronal polarity and in the critical task of selective trafficking of membrane protein to axons.
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Affiliation(s)
- Linda Soo Hoo
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Chris D. Banna
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Carolyn M. Radeke
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Nikunj Sharma
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Mary E. Albertolle
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Seng Hui Low
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Thomas Weimbs
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Carol A. Vandenberg
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
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11
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Ng FS, Jackson FR. The ROP vesicle release factor is required in adult Drosophila glia for normal circadian behavior. Front Cell Neurosci 2015; 9:256. [PMID: 26190976 PMCID: PMC4490253 DOI: 10.3389/fncel.2015.00256] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/22/2015] [Indexed: 11/22/2022] Open
Abstract
We previously showed that endocytosis and/or vesicle recycling mechanisms are essential in adult Drosophila glial cells for the neuronal control of circadian locomotor activity. In this study, our goal was to identify specific glial vesicle trafficking, recycling, or release factors that are required for rhythmic behavior. From a glia-specific, RNAi-based genetic screen, we identified eight glial factors that are required for normally robust circadian rhythms in either a light-dark cycle or in constant dark conditions. In particular, we show that conditional knockdown of the ROP vesicle release factor in adult glial cells results in arrhythmic behavior. Immunostaining for ROP reveals reduced protein in glial cell processes and an accumulation of the Par Domain Protein 1ε (PDP1ε) clock output protein in the small lateral clock neurons. These results suggest that glia modulate rhythmic circadian behavior by secretion of factors that act on clock neurons to regulate a clock output factor.
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Affiliation(s)
- Fanny S Ng
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - F Rob Jackson
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
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