51
|
Kim T, Tanaka-Yamamoto K. Postsynaptic Stability and Variability Described by a Stochastic Model of Endosomal Trafficking. Front Cell Neurosci 2019; 13:72. [PMID: 30863286 PMCID: PMC6399135 DOI: 10.3389/fncel.2019.00072] [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: 10/12/2018] [Accepted: 02/13/2019] [Indexed: 12/04/2022] Open
Abstract
Neurons undergo dynamic processes of constitutive AMPA-type glutamate receptor (AMPAR) trafficking, such as the insertion and internalization of AMPARs by exocytosis and endocytosis, while stably maintaining synaptic efficacy. Studies using advanced imaging techniques have suggested that the frequency of these constitutive trafficking processes, as well as the number of AMPARs that are involved in a particular event highly fluctuate. In addition, mechanisms that trigger some forms of synaptic plasticity have been shown to include not only these processes but also additional fluctuating processes, such as the sorting of AMPARs to late endosomes (LEs). Thus, the regulation of postsynaptic AMPARs by the endosomal trafficking system appears to have superficially conflicting properties between the stability or organized control of plasticity and highly fluctuating or stochastic processes. However, it is not clear how the endosomal trafficking system reconciles and utilizes such conflicting properties. Although deterministic models have been effective to describe the stable maintenance of synaptic AMPAR numbers by constitutive recycling, as well as the involvement of endosomal trafficking in synaptic plasticity, they do not take stochasticity into account. In this study, we introduced the stochasticity into the model of each crucial machinery of the endosomal trafficking system. The specific questions we solved by our improved model are whether stability is accomplished even with a combination of fluctuating processes, and how overall variability occurs while controlling long-term synaptic depression (LTD). Our new stochastic model indeed demonstrated the stable regulation of postsynaptic AMPAR numbers at the basal state and during LTD maintenance, despite fast fluctuations in AMPAR numbers as well as high variability in the time course and amounts of LTD. In addition, our analysis suggested that the high variability arising from this stochasticity is beneficial for reproducing the relatively constant timing of LE sorting for LTD. We therefore propose that the coexistence of stability and stochasticity in the endosomal trafficking system is suitable for stable synaptic transmission and the reliable induction of synaptic plasticity, with variable properties that have been observed experimentally.
Collapse
Affiliation(s)
- Taegon Kim
- Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul, South Korea
| | - Keiko Tanaka-Yamamoto
- Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul, South Korea
| |
Collapse
|
52
|
Sohn H, Park M. Palmitoylation-mediated synaptic regulation of AMPA receptor trafficking and function. Arch Pharm Res 2019; 42:426-435. [PMID: 30838509 PMCID: PMC6505502 DOI: 10.1007/s12272-019-01134-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/19/2019] [Indexed: 12/23/2022]
Abstract
The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is a major glutamate-gated ion channel in the brain and is important for synaptic transmission, synaptic plasticity, and learning. Palmitoylation, a post-translational modification, is a critical process regulating AMPAR trafficking, synaptic function and plasticity, and learning and memory in health and diseases. In this review, we discuss current knowledge on the palmitoylation-dependent regulation of AMPAR trafficking and functions. We focus on the palmitoylation of AMPARs and other synaptic proteins that directly or indirectly interact with AMPARs, including postsynaptic density 95, glutamate receptor-interacting protein/AMPAR-binding protein, A-kinase anchoring protein 79/150, and protein interacting with C kinase 1. Finally, we discuss what future studies should address in the field of palmitoylation-dependent AMPAR trafficking and function with regard to physiology and neurodegenerative diseases.
Collapse
Affiliation(s)
- Heesung Sohn
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, 02792, South Korea.,Department of Life Sciences, School of Natural Science, Hanyang University, Seoul, 04763, South Korea
| | - Mikyoung Park
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, 02792, South Korea. .,Department of Neuroscience, Korea University of Science and Technology, Daejeon, 34113, South Korea.
| |
Collapse
|
53
|
The Disease-Associated Chaperone FKBP51 Impairs Cognitive Function by Accelerating AMPA Receptor Recycling. eNeuro 2019; 6:eN-NWR-0242-18. [PMID: 30963102 PMCID: PMC6450497 DOI: 10.1523/eneuro.0242-18.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 01/18/2019] [Accepted: 02/01/2019] [Indexed: 12/22/2022] Open
Abstract
Increased expression of the FK506-binding protein 5 (FKBP5) gene has been associated with a number of diseases, but most prominently in connection to psychiatric illnesses. Many of these psychiatric disorders present with dementia and other cognitive deficits, but a direct connection between these issues and alterations in FKBP5 remains unclear. We generated a novel transgenic mouse to selectively overexpress FKBP5, which encodes the FKBP51 protein, in the corticolimbic system, which had no overt effects on gross body weight, motor ability, or general anxiety. Instead, we found that overexpression of FKBP51 impaired long-term depression (LTD) as well as spatial reversal learning and memory, suggesting a role in glutamate receptor regulation. Indeed, FKBP51 altered the association of heat-shock protein 90 (Hsp90) with AMPA receptors, which was accompanied by an accelerated rate of AMPA recycling. In this way, the chaperone system is critical in triage decisions for AMPA receptor trafficking. Imbalance in the chaperone system may manifest in impairments in both inhibitory learning and cognitive function. These findings uncover an unexpected and essential mechanism for learning and memory that is controlled by the psychiatric risk factor FKBP5.
Collapse
|
54
|
Mueller TM, Kim P, Meador-Woodruff JH. Fractionation of Subcellular Compartments from Human Brain Tissue. Methods Mol Biol 2019; 1941:201-223. [PMID: 30707436 DOI: 10.1007/978-1-4939-9077-1_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Subcellular fractionation methods permit the isolation, purification, and/or enrichment of specific cellular compartments from complex tissue samples. Enrichment of multiple subcellular compartments from the same tissue sample permits comparisons of the spatial distribution of target proteins between specific intracellular compartments and, in some cases, can provide information about spatiotemporal processing of key cellular components. Here we describe a method to generate subcellular fractions enriched for heavy membranes and nuclei, rough and smooth endoplasmic reticulum membranes, light membranes and cytosol, synapses, and other intermediate cellular membranes from postmortem human brain tissue. These subcellular fractions can be used in a variety of downstream applications to assess the localization, relative abundance, and stoichiometry of glutamate receptor subunits along the forward trafficking pathway.
Collapse
Affiliation(s)
- Toni M Mueller
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Pitna Kim
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
55
|
Wang H, Li X, Xie X, Zhao H, Gao Y, Li Y, Xu X, Zhang X, Ke C, Liu J. Promotion of bone cancer pain development by decorin is accompanied by modification of excitatory synaptic molecules in the spinal cord. Mol Pain 2019; 15:1744806919864253. [PMID: 31258052 PMCID: PMC6659184 DOI: 10.1177/1744806919864253] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 06/16/2019] [Accepted: 06/18/2019] [Indexed: 01/25/2023] Open
Abstract
Bone cancer pain is refractory to currently available clinical treatment owing to its complicated underlying mechanisms. Studies found that extracellular matrix molecules can participate in the regulation of chronic pain. Decorin is one of the most abundant extracellular matrix molecules, and the present study evaluated the effect of decorin on the development of bone cancer pain. We found that decorin was upregulated in the L4–L6 spinal dorsal horn of the bone cancer pain rats. Spinal microinjection of a decorin-targeting RNAi lentivirus alleviated bone cancer pain-induced mechanical allodynia and reduced the expression of pGluR1-Ser831 in the bone cancer pain rats. Meanwhile, decorin knockdown impaired the excitatory synaptogenesis in cultured neurons and prevented the clustering and insertion of pGluR1-Ser831 into postsynaptic membranes. Taken together, the results of our study suggested that decorin contributes to the development of bone cancer pain possibly by regulating the activity of excitatory synaptic molecules in the spinal cord. Our findings provide a better understanding of the function of decorin as a possible therapeutic target for alleviating bone cancer pain.
Collapse
Affiliation(s)
- Huan Wang
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xiaohui Li
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xianqiao Xie
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Haiwen Zhao
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Yan Gao
- Department of PET Center, Taihe Hospital, Hubei University of
Medicine, Shiyan, Hubei, China
| | - Yang Li
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xueqin Xu
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xiaofei Zhang
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Changbin Ke
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Juying Liu
- Department of Anesthesiology, Institute of Anesthesiology &
Pain, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| |
Collapse
|
56
|
Itoh M, Okuno H, Yamada D, Yamashita M, Abe M, Natsume R, Kaizuka T, Sakimura K, Hoshino M, Mishina M, Wada K, Sekiguchi M, Hayashi T. Perturbed expression pattern of the immediate early gene Arc in the dentate gyrus of GluA1 C-terminal palmitoylation-deficient mice. Neuropsychopharmacol Rep 2018; 39:61-66. [PMID: 30536651 PMCID: PMC7292270 DOI: 10.1002/npr2.12044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/14/2018] [Accepted: 11/16/2018] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AMPA receptors predominantly mediate fast excitatory synaptic transmission in the mammalian brain. Post-translational protein S-palmitoylation of AMPA receptor GluA subunits at their C-termini reversibly controls the receptors trafficking to and from excitatory glutamatergic synapses. Excitatory inputs to neurons induce the expression of immediate early genes (IEGs), including Arc, with particular spatial patterns. In the hippocampal dentate gyrus, Arc is mainly expressed in the upper (dorsal) blade at the basal state. GluA1 C-terminal palmitoylation-deficient (GluA1C811S) mice showed enhanced seizure susceptibility and disturbed synaptic plasticity without impaired gross anatomy or basal synaptic transmission. These mutant mice also exhibited an increased expression of IEG products, c-Fos and Arc proteins, in the hippocampus and cerebral cortex. In this report, we further analyzed excitability and Arc expression pattern in the dentate gyrus of GluA1C811S mice. METHODS AND RESULTS Electrophysiological analysis of granule neurons to measure the evoked excitatory postsynaptic current/evoked inhibitory postsynaptic current ratio revealed that excitatory/inhibitory (E/I) balance was normal in GluA1C811S mice. In contrast, immunohistochemical staining showed an abnormal distribution of Arc-positive cells between upper and lower (ventral) blades of the dentate gyrus in these mutant mice. These data suggest that deficiency of GluA1 palmitoylation causes perturbed neuronal inputs from the entorhinal cortex to the dentate gyrus, which potentially underlies the excessive excitability in response to seizure-inducing stimulation. CONCLUSION Our findings conclude that an appropriate regulation of Arc expression in the dentate gyrus, ensured by AMPA receptor palmitoylation, may be critical for stabilizing hippocampal neural circuits and may suppress excess excitation.
Collapse
Affiliation(s)
- Masayuki Itoh
- Section of Cellular Biochemistry, Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan.,Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Hiroyuki Okuno
- Medical Innovation Center/SK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Biochemistry and Molecular Biology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Daisuke Yamada
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Mariko Yamashita
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Rie Natsume
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Toshie Kaizuka
- Section of Cellular Biochemistry, Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan.,Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Masayoshi Mishina
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.,Brain Science Laboratory, The Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Japan
| | - Keiji Wada
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Masayuki Sekiguchi
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan
| | - Takashi Hayashi
- Section of Cellular Biochemistry, Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan.,Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan.,Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| |
Collapse
|
57
|
Parkinson GT, Hanley JG. Mechanisms of AMPA Receptor Endosomal Sorting. Front Mol Neurosci 2018; 11:440. [PMID: 30568574 PMCID: PMC6289981 DOI: 10.3389/fnmol.2018.00440] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/13/2018] [Indexed: 12/21/2022] Open
Abstract
The regulation of synaptic AMPA receptors (AMPARs) is critical for excitatory synaptic transmission, synaptic plasticity and the consequent formation of neural circuits during brain development and their modification during learning and memory processes. The number of synaptic AMPARs is regulated through endocytosis, exocytosis and endosomal sorting that results in recycling back to the plasma membrane or degradation in the lysosome. Hence, endo-lysosomal sorting is vitally important in maintaining AMPAR expression at the synapse, and the dynamic regulation of these trafficking events is a key component of synaptic plasticity. A reduction in synaptic strength such as in long-term depression (LTD) involves AMPAR sorting to lysosomes to reduce synaptic AMPAR number, whereas long-term potentiation (LTP) involves an increase in AMPAR recycling to increase the number of AMPARs at synapses. Here, we review our current understanding of the endosomal trafficking routes taken by AMPARs, and the mechanisms involved in AMPAR endosomal sorting, focussing on the numerous AMPAR associated proteins that have been implicated in this complex process. We also discuss how these events are dysregulated in brain disorders.
Collapse
Affiliation(s)
- Gabrielle T Parkinson
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Jonathan G Hanley
- Centre for Synaptic Plasticity and School of Biochemistry, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
58
|
Jin DZ, Mao LM, Wang JQ. The Role of Extracellular Signal-Regulated Kinases (ERK) in the Regulation of mGlu5 Receptors in Neurons. J Mol Neurosci 2018; 66:629-638. [PMID: 30430306 PMCID: PMC6312115 DOI: 10.1007/s12031-018-1193-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 10/01/2018] [Indexed: 12/21/2022]
Abstract
The metabotropic glutamate (mGlu) receptor 5 is a G protein-coupled receptor and is densely expressed in the mammalian brain. Like other glutamate receptors, mGlu5 receptors are tightly regulated by posttranslational modifications such as phosphorylation, although underlying mechanisms are incompletely investigated. In this study, we investigated the role of a prime kinase, extracellular signal-regulated kinase 1 (ERK1), in the phosphorylation and regulation of mGlu5 receptors in vitro and in striatal neurons. We found that recombinant ERK1 proteins directly bound to the C-terminal tail (CT) of mGlu5 receptors in vitro. Endogenous ERK1 also interacted with mGlu5 receptor proteins in adult rat striatal neurons in vivo. The kinase showed the ability to phosphorylate mGlu5 receptors. A serine residue in the distal region of mGlu5 CT was found to be a primary phosphorylation site sensitive to ERK1. In functional studies, we found that pharmacological inhibition of ERK with an inhibitor U0126 reduced the efficacy of mGlu5 receptors in stimulating production of cytoplasmic inositol-1,4,5-triphosphate, a major downstream conventional signaling event, in striatal neurons under normal conditions. These results identify mGlu5 as a new biochemical substrate of ERK1. The kinase can interact with and phosphorylate an intracellular domain of mGlu5 receptors in striatal neurons and thereby control its signaling efficacy.
Collapse
Affiliation(s)
- Dao-Zhong Jin
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA.
| | - Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA
| | - John Q Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA.
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA.
| |
Collapse
|
59
|
Park M. AMPA Receptor Trafficking for Postsynaptic Potentiation. Front Cell Neurosci 2018; 12:361. [PMID: 30364291 PMCID: PMC6193507 DOI: 10.3389/fncel.2018.00361] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 09/25/2018] [Indexed: 01/25/2023] Open
Abstract
Long-term potentiation (LTP) of excitatory synaptic strength, which has long been considered a synaptic correlate for learning and memory, requires a fast recruitment of additional α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors (AMPARs) to the postsynaptic sites. As cell biological concepts have been applied to the field and genetic manipulation and microscopic imaging technologies have been advanced, visualization of the trafficking of AMPARs to synapses for LTP has been investigated intensively over the last decade. Recycling endosomes have been reported as intracellular storage organelles to supply AMPARs for LTP through the endocytic recycling pathway. In addition, exocytic domains in the spine plasma membrane, where AMPARs are inserted from the intracellular compartment, and nanodomains, where diffusing AMPARs are trapped and immobilized inside synapses for LTP, have been described. Furthermore, cell surface lateral diffusion of AMPARs from extrasynaptic to synaptic sites has been reported as a key step for AMPAR location to the synaptic sites for LTP. This review article will discuss recent findings and views on the reservoir(s) of AMPARs and their trafficking for LTP expression by focusing on the exocytosis and lateral diffusion of AMPARs, and provide some future directions that need to be addressed in the field of LTP.
Collapse
Affiliation(s)
- Mikyoung Park
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Department of Neuroscience, Korea University of Science and Technology, Daejeon, South Korea
| |
Collapse
|
60
|
Joshi S, Kapur J. Mechanisms of status epilepticus: α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor hypothesis. Epilepsia 2018; 59 Suppl 2:78-81. [PMID: 30159880 DOI: 10.1111/epi.14482] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2017] [Indexed: 02/03/2023]
Abstract
Prolonged seizures of status epilepticus (SE) result from failure of mechanisms of seizure termination or activation of mechanisms that sustain seizures. Reduced γ-aminobutyric acid type A receptor-mediated synaptic transmission contributes to impairment of seizure termination. However, mechanisms that sustain prolonged seizures are not known. We propose that insertion of GluA1 subunits at the glutamatergic synapses causes potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic receptor (AMPAR)-mediated neurotransmission, which helps to spread and sustain seizures. The AMPAR-mediated neurotransmission of CA1 pyramidal neurons was increased in animals in SE induced by pilocarpine. The surface membrane expression of GluA1 subunit-containing AMPARs on CA1 pyramidal neurons was also increased. Blockade of N-methyl-d-aspartate receptors 10 minutes after the onset of continuous electrographic seizure activity prevented the increase in the surface expression of GluA1 subunits. N-methyl-d-aspartate receptor antagonist MK-801 in conjunction with diazepam also terminated seizures that were refractory to MK-801 or diazepam alone. Future studies using mice lacking the GluA1 subunit expression will provide further insights into the role of GluA1 subunit-containing AMPAR plasticity in sustaining seizures of SE.
Collapse
Affiliation(s)
- Suchitra Joshi
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Charlottesville, VA, USA.,Department of Neuroscience, University of Virginia, Charlottesville, VA, USA.,UVA Brain Institute, University of Virginia, Charlottesville, VA, USA
| |
Collapse
|
61
|
Wang Q, Han TH, Nguyen P, Jarnik M, Serpe M. Tenectin recruits integrin to stabilize bouton architecture and regulate vesicle release at the Drosophila neuromuscular junction. eLife 2018; 7:35518. [PMID: 29901439 PMCID: PMC6040883 DOI: 10.7554/elife.35518] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 06/13/2018] [Indexed: 11/15/2022] Open
Abstract
Assembly, maintenance and function of synaptic junctions depend on extracellular matrix (ECM) proteins and their receptors. Here we report that Tenectin (Tnc), a Mucin-type protein with RGD motifs, is an ECM component required for the structural and functional integrity of synaptic specializations at the neuromuscular junction (NMJ) in Drosophila. Using genetics, biochemistry, electrophysiology, histology and electron microscopy, we show that Tnc is secreted from motor neurons and striated muscles and accumulates in the synaptic cleft. Tnc selectively recruits αPS2/βPS integrin at synaptic terminals, but only the cis Tnc/integrin complexes appear to be biologically active. These complexes have distinct pre- and postsynaptic functions, mediated at least in part through the local engagement of the spectrin-based membrane skeleton: the presynaptic complexes control neurotransmitter release, while postsynaptic complexes ensure the size and architectural integrity of synaptic boutons. Our study reveals an unprecedented role for integrin in the synaptic recruitment of spectrin-based membrane skeleton. Nerve cells or neurons can communicate with each other by releasing chemical messengers into the gap between them, the synapse. Both neurons and synapses are surrounded by a network of proteins called the extracellular matrix, which anchors, protects and supports the synapse. The matrix also helps to regulate the dynamic communication across the synapses and consequently neurons. Little is known about the proteins of the extracellular matrix, in particular about the ones involved in structural support. This is especially important for the so-called neuromuscular junctions, where neurons stimulate muscle contraction and trigger vigorous movement. Receptor proteins on cell surfaces, such as integrins, can bind to the extracellular matrix proteins to anchor the cells and are important for all cell junctions, including synaptic junctions. But because of their many essential roles during development, it was unclear how integrins modulate the activity of the synapse. To investigate this further, Wang et al. studied the neuromuscular junctions of fruit flies. The experiments revealed that both muscle and neurons secrete a large protein called Tenectin, which accumulates into the small space between the neuron and the muscle, the synaptic cleft. This protein can bind to integrin and is necessary to support the neuromuscular junction structurally and functionally. Wang et al. discovered that Tenectin works by gathering integrins on the surface of the neuron and the muscle. In the neuron, Tenectin forms complexes with integrin to regulate the release of neurotransmitters. In the muscle, the complexes provide support to the synaptic structures. However, when Tenectin was experimentally removed, it only disrupted the integrins at the neuromuscular junction, without affecting integrins in other regions of the cells, such as the site where the muscle uses integrins to attach to the tendon. Moreover, without Tenectin an important intracellular scaffolding meshwork that lines up and reinforces cell membranes was no longer organized properly at the synapse. A next step will be to identify the missing components between Tenectin/integrin complexes on the surface of neurons and the neurotransmitter release machinery inside the cells. The extracellular matrix and its receptors play fundamental roles in the development and function of the nervous system. A better knowledge of the underlying mechanisms will help us to better understand the complex interplay between the synapse and the extracellular matrix.
Collapse
Affiliation(s)
- Qi Wang
- Section on Cellular Communication, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Tae Hee Han
- Section on Cellular Communication, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Peter Nguyen
- Section on Cellular Communication, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Michal Jarnik
- Section on Intracellular Protein Trafficking, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Mihaela Serpe
- Section on Cellular Communication, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| |
Collapse
|
62
|
Persistent Stress-Induced Neuroplastic Changes in the Locus Coeruleus/Norepinephrine System. Neural Plast 2018; 2018:1892570. [PMID: 30008741 PMCID: PMC6020552 DOI: 10.1155/2018/1892570] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/09/2018] [Accepted: 05/27/2018] [Indexed: 11/25/2022] Open
Abstract
Neural plasticity plays a critical role in mediating short- and long-term brain responses to environmental stimuli. A major effector of plasticity throughout many regions of the brain is stress. Activation of the locus coeruleus (LC) is a critical step in mediating the neuroendocrine and behavioral limbs of the stress response. During stressor exposure, activation of the hypothalamic-pituitary-adrenal axis promotes release of corticotropin-releasing factor in LC, where its signaling promotes a number of physiological and cellular changes. While the acute effects of stress on LC physiology have been described, its long-term effects are less clear. This review will describe how stress changes LC neuronal physiology, function, and morphology from a genetic, cellular, and neuronal circuitry/transmission perspective. Specifically, we describe morphological changes of LC neurons in response to stressful stimuli and signal transduction pathways underlying them. Also, we will review changes in excitatory glutamatergic synaptic transmission in LC neurons and possible stress-induced modifications of AMPA receptors. This review will also address stress-related behavioral adaptations and specific noradrenergic receptors responsible for them. Finally, we summarize the results of several human studies which suggest a link between stress, altered LC function, and pathogenesis of posttraumatic stress disorder.
Collapse
|
63
|
Wang G, Li S, Gilbert J, Gritton HJ, Wang Z, Li Z, Han X, Selkoe DJ, Man HY. Crucial Roles for SIRT2 and AMPA Receptor Acetylation in Synaptic Plasticity and Memory. Cell Rep 2018; 20:1335-1347. [PMID: 28793258 DOI: 10.1016/j.celrep.2017.07.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 04/14/2017] [Accepted: 07/13/2017] [Indexed: 01/06/2023] Open
Abstract
AMPA receptors (AMPARs) mediate fast excitatory synaptic transmission and are crucial for synaptic plasticity, learning, and memory. However, the molecular control of AMPAR stability and its neurophysiological significance remain unclear. Here, we report that AMPARs are subject to lysine acetylation at their C termini. Acetylation reduces AMPAR internalization and degradation, leading to increased cell-surface localization and prolonged receptor half-life. Through competition for the same lysine residues, acetylation intensity is inversely related to the levels of AMPAR ubiquitination. We find that sirtuin 2 (SIRT2) acts as an AMPAR deacetylase regulating AMPAR trafficking and proteostasis. SIRT2 knockout mice (Sirt2-/-) show marked upregulation in AMPAR acetylation and protein accumulation. Both Sirt2-/- mice and mice expressing acetylation mimetic GluA1 show aberrant synaptic plasticity, accompanied by impaired learning and memory. These findings establish SIRT2-regulated lysine acetylation as a form of AMPAR post-translational modification that regulates its turnover, as well as synaptic plasticity and cognitive function.
Collapse
Affiliation(s)
- Guan Wang
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Shaomin Li
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - James Gilbert
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Howard J Gritton
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Zemin Wang
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Zhangyuan Li
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Xue Han
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Dennis J Selkoe
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Heng-Ye Man
- Department of Biology, Boston University, Boston, MA 02215, USA; Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA.
| |
Collapse
|
64
|
Sossin WS. Memory Synapses Are Defined by Distinct Molecular Complexes: A Proposal. Front Synaptic Neurosci 2018; 10:5. [PMID: 29695960 PMCID: PMC5904272 DOI: 10.3389/fnsyn.2018.00005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/26/2018] [Indexed: 12/17/2022] Open
Abstract
Synapses are diverse in form and function. While there are strong evidential and theoretical reasons for believing that memories are stored at synapses, the concept of a specialized “memory synapse” is rarely discussed. Here, we review the evidence that memories are stored at the synapse and consider the opposing possibilities. We argue that if memories are stored in an active fashion at synapses, then these memory synapses must have distinct molecular complexes that distinguish them from other synapses. In particular, examples from Aplysia sensory-motor neuron synapses and synapses on defined engram neurons in rodent models are discussed. Specific hypotheses for molecular complexes that define memory synapses are presented, including persistently active kinases, transmitter receptor complexes and trans-synaptic adhesion proteins.
Collapse
Affiliation(s)
- Wayne S Sossin
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| |
Collapse
|
65
|
Leptin in the nucleus accumbens blocks the increase of GluA1 phosphorylation induced by acute cocaine administration. Neuroreport 2018. [DOI: 10.1097/wnr.0000000000001001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
66
|
Mao LM, He N, Jin DZ, Wang JQ. Regulation of Phosphorylation of AMPA Glutamate Receptors by Muscarinic M4 Receptors in the Striatum In vivo. Neuroscience 2018; 375:84-93. [PMID: 29432883 DOI: 10.1016/j.neuroscience.2018.01.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 10/18/2022]
Abstract
The acetylcholine muscarinic 4 (M4) receptor is a principal muscarinic receptor subtype present in the striatum. Notably, Gαi/o-coupled M4 receptors and Gαs/Golf-coupled dopamine D1 receptors are coexpressed in striatonigral projection neurons and are thought to interact with each other to regulate neuronal excitability, although underlying molecular mechanisms are poorly understood. In this study, we investigated the role of M4 receptors in the regulation of phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the rat normal and dopamine-stimulated striatum in vivo. We found that a systemic injection of a M4 antagonist tropicamide increased AMPA receptor GluA1 subunit phosphorylation at a protein kinase A-dependent site (S845) in the striatum. The tropicamide-induced S845 phosphorylation was rapid, reversible, and dose-dependent and occurred in the two subdivisions of the striatum, i.e., the caudate putamen and nucleus accumbens. Coadministration of subthreshold doses of tropicamide and a D1 agonist SKF81297 induced a significant increase in S845 phosphorylation. Coadministered tropicamide and a dopamine psychostimulant amphetamine at their subthreshold doses also elevated S845 phosphorylation. Tropicamide alone or coinjected with SKF81297 or amphetamine had no effect on GluA1 phosphorylation at S831. Tropicamide did not affect GluA2 phosphorylation at S880. These results reveal a selective inhibitory linkage from M4 receptors to GluA1 in S845 phosphorylation in striatal neurons. Blockade of the M4-mediated inhibition significantly augments constitutive and dopamine-stimulated GluA1 S845 phosphorylation.
Collapse
Affiliation(s)
- Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Nan He
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Dao-Zhong Jin
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - John Q Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA; Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
| |
Collapse
|
67
|
Pharmacological modulation of AMPA receptor phosphorylation by dopamine and muscarinic receptor agents in the rat medial prefrontal cortex. Eur J Pharmacol 2018; 820:45-52. [DOI: 10.1016/j.ejphar.2017.12.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/06/2017] [Accepted: 12/08/2017] [Indexed: 11/24/2022]
|
68
|
Jurado S. AMPA Receptor Trafficking in Natural and Pathological Aging. Front Mol Neurosci 2018; 10:446. [PMID: 29375307 PMCID: PMC5767248 DOI: 10.3389/fnmol.2017.00446] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/21/2017] [Indexed: 01/09/2023] Open
Abstract
α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) enable most excitatory transmission in the brain and are crucial for mediating basal synaptic strength and plasticity. Because of the importance of their function, AMPAR dynamics, activity and subunit composition undergo a tight regulation which begins as early as prenatal development and continues through adulthood. Accumulating evidence suggests that the precise regulatory mechanisms involved in orchestrating AMPAR trafficking are challenged in the aging brain. In turn dysregulation of AMPARs can be linked to most neurological and neurodegenerative disorders. Understanding the mechanisms that govern AMPAR signaling during natural and pathological cognitive decline will guide the efforts to develop most effective ways to tackle neurodegenerative diseases which are one of the primary burdens afflicting an increasingly aging population. In this review, I provide a brief overview of the molecular mechanisms involved in AMPAR trafficking highlighting what is currently known about how these processes change with age and disease. As a particularly well-studied example of AMPAR dysfunction in pathological aging I focus in Alzheimer’s disease (AD) with special emphasis in how the production of neurofibrillary tangles (NFTs) and amyloid-β plaques may contribute to disruption in AMPAR function.
Collapse
Affiliation(s)
- Sandra Jurado
- Instituto de Neurociencias CSIC-UMH, San Juan de Alicante, Spain
| |
Collapse
|
69
|
The C-terminal tails of endogenous GluA1 and GluA2 differentially contribute to hippocampal synaptic plasticity and learning. Nat Neurosci 2017; 21:50-62. [PMID: 29230056 DOI: 10.1038/s41593-017-0030-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/24/2017] [Indexed: 11/09/2022]
Abstract
Long-term potentiation (LTP) and depression (LTD) at glutamatergic synapses are intensively investigated processes for understanding the synaptic basis for learning and memory, but the underlying molecular mechanisms remain poorly understood. We have made three mouse lines where the C-terminal domains (CTDs) of endogenous AMPA receptors (AMPARs), the principal mediators of fast excitatory synaptic transmission, are specifically exchanged. These mice display profound deficits in synaptic plasticity without any effects on basal synaptic transmission. Our study reveals that the CTDs of GluA1 and GluA2, the key subunits of AMPARs, are necessary and sufficient to drive NMDA receptor-dependent LTP and LTD, respectively. In addition, these domains exert differential effects on spatial and contextual learning and memory. These results establish dominant roles of AMPARs in governing bidirectional synaptic and behavioral plasticity in the CNS.
Collapse
|
70
|
Carta G, Murru E, Banni S, Manca C. Palmitic Acid: Physiological Role, Metabolism and Nutritional Implications. Front Physiol 2017; 8:902. [PMID: 29167646 PMCID: PMC5682332 DOI: 10.3389/fphys.2017.00902] [Citation(s) in RCA: 376] [Impact Index Per Article: 53.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 10/24/2017] [Indexed: 12/19/2022] Open
Abstract
Palmitic acid (PA) has been for long time negatively depicted for its putative detrimental health effects, shadowing its multiple crucial physiological activities. PA is the most common saturated fatty acid accounting for 20–30% of total fatty acids in the human body and can be provided in the diet or synthesized endogenously via de novo lipogenesis (DNL). PA tissue content seems to be controlled around a well-defined concentration, and changes in its intake do not influence significantly its tissue concentration because the exogenous source is counterbalanced by PA endogenous biosynthesis. Particular physiopathological conditions and nutritional factors may strongly induce DNL, resulting in increased tissue content of PA and disrupted homeostatic control of its tissue concentration. The tight homeostatic control of PA tissue concentration is likely related to its fundamental physiological role to guarantee membrane physical properties but also to consent protein palmitoylation, palmitoylethanolamide (PEA) biosynthesis, and in the lung an efficient surfactant activity. In order to maintain membrane phospholipids (PL) balance may be crucial an optimal intake of PA in a certain ratio with unsaturated fatty acids, especially PUFAs of both n-6 and n-3 families. However, in presence of other factors such as positive energy balance, excessive intake of carbohydrates (in particular mono and disaccharides), and a sedentary lifestyle, the mechanisms to maintain a steady state of PA concentration may be disrupted leading to an over accumulation of tissue PA resulting in dyslipidemia, hyperglycemia, increased ectopic fat accumulation and increased inflammatory tone via toll-like receptor 4. It is therefore likely that the controversial data on the association of dietary PA with detrimental health effects, may be related to an excessive imbalance of dietary PA/PUFA ratio which, in certain physiopathological conditions, and in presence of an enhanced DNL, may further accelerate these deleterious effects.
Collapse
Affiliation(s)
- Gianfranca Carta
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Elisabetta Murru
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Sebastiano Banni
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Claudia Manca
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| |
Collapse
|
71
|
Widagdo J, Guntupalli S, Jang SE, Anggono V. Regulation of AMPA Receptor Trafficking by Protein Ubiquitination. Front Mol Neurosci 2017; 10:347. [PMID: 29123470 PMCID: PMC5662755 DOI: 10.3389/fnmol.2017.00347] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/12/2017] [Indexed: 11/27/2022] Open
Abstract
The molecular mechanisms underlying plastic changes in the strength and connectivity of excitatory synapses have been studied extensively for the past few decades and remain the most attractive cellular models of learning and memory. One of the major mechanisms that regulate synaptic plasticity is the dynamic adjustment of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor content on the neuronal plasma membrane. The expression of surface AMPA receptors (AMPARs) is controlled by the delicate balance between the biosynthesis, dendritic transport, exocytosis, endocytosis, recycling and degradation of the receptors. These processes are dynamically regulated by AMPAR interacting proteins as well as by various post-translational modifications that occur on their cytoplasmic domains. In the last few years, protein ubiquitination has emerged as a major regulator of AMPAR intracellular trafficking. Dysregulation of AMPAR ubiquitination has also been implicated in the pathophysiology of Alzheimer’s disease. Here we review recent advances in the field and provide insights into the role of protein ubiquitination in regulating AMPAR membrane trafficking and function. We also discuss how aberrant ubiquitination of AMPARs contributes to the pathogenesis of various neurological disorders, including Alzheimer’s disease, chronic stress and epilepsy.
Collapse
Affiliation(s)
- Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Sumasri Guntupalli
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Se E Jang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| |
Collapse
|
72
|
Machado I, Schiöth HB, Lasaga M, Scimonelli T. IL-1β reduces GluA1 phosphorylation and its surface expression during memory reconsolidation and α-melanocyte-stimulating hormone can modulate these effects. Neuropharmacology 2017; 128:314-323. [PMID: 29042315 DOI: 10.1016/j.neuropharm.2017.09.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 09/21/2017] [Accepted: 09/26/2017] [Indexed: 10/18/2022]
Abstract
Pro-inflammatory cytokines can affect cognitive processes such as learning and memory. Particularly, interleukin-1β (IL-1β) influences hippocampus-dependent memories. We previously reported that administration of IL-1β in dorsal hippocampus impaired contextual fear memory reconsolidation. This effect was reversed by the melanocortin alpha-melanocyte-stimulating hormone (α-MSH). Our results also demonstrated that IL-1β produced a significant decrease in glutamate release from dorsal hippocampus synaptosomes after reactivation of the fear memory. Therefore, we investigated whether IL-1β administration can affect GluA1 AMPA subunit phosphorylation, surface expression, and total expression during reconsolidation of a contextual fear memory. Also, we studied the modulatory effect of α-MSH. We found that IL-1β reduced phosphorylation of this subunit at Serine 831 and Serine 845 60 min after contextual fear memory reactivation. The intrahippocampal administration of IL-1β after memory reactivation also induced a decrease in surface expression and total expression of GluA1. α-MSH prevented the effect of IL-1β on GluA1 phosphorylation in Serine 845, but not in Serine 831. Moreover, treatment with α-MSH also prevented the effect of the cytokine on GluA1 surface and total expression after memory reactivation. Our results demonstrated that IL-1β regulates phosphorylation of GluA1 and may thus play an important role in modulation of AMPAR function and synaptic plasticity in the brain. These findings further illustrate the importance of IL-1β in cognition processes dependent on the hippocampus, and also reinforced the fact that α-MSH can reverse IL-1β effects on memory reconsolidation.
Collapse
Affiliation(s)
- Ivana Machado
- IFEC-CONICET, Depto. de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
| | - Helgi B Schiöth
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden.
| | - Mercedes Lasaga
- Instituto de Investigaciones Biomédicas INBIOMED UBA-CONICET, Facultad de Medicina, Buenos Aires, Argentina.
| | - Teresa Scimonelli
- IFEC-CONICET, Depto. de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
| |
Collapse
|
73
|
Hippocampal LTP and contextual learning require surface diffusion of AMPA receptors. Nature 2017; 549:384-388. [PMID: 28902836 PMCID: PMC5683353 DOI: 10.1038/nature23658] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 07/21/2017] [Indexed: 12/21/2022]
Abstract
Long-term potentiation (LTP) of excitatory synaptic transmission has long been considered a cellular correlate for learning and memory1,2. Early LTP (eLTP, <1 hour) had initially been explained either by presynaptic increases in glutamate release3–5 or by direct modification of post-synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) function6,7. Compelling models have more recently proposed that synaptic potentiation can occur by the recruitment of additional post-synaptic AMPARs8, sourced either from an intracellular reserve pool by exocytosis or from nearby extra synaptic receptors pre-existing on the neuronal surface9–12. However, the exact mechanism through which synapses can rapidly recruit new AMPARs during eLTP is still unknown. In particular, direct evidence for a pivotal role of AMPAR surface diffusion as a trafficking mechanism in synaptic plasticity is still lacking. Using AMPAR immobilization approaches, we show that interfering with AMPAR surface diffusion dramatically impaired synaptic potentiation of Schaffer collateral/commissural inputs to cornu ammonis area 1 (CA1) in cultured slices, acute slices and in vivo. Our data also identifies distinct contributions of various AMPAR trafficking routes to the temporal profile of synaptic potentiation. In addition, AMPAR immobilization in vivo in the dorsal hippocampus (DH) before fear conditioning, indicated that AMPAR diffusion is important for the early phase of contextual learning. Therefore, our results provide a direct demonstration that the recruitment of new receptors to synapses by surface diffusion is a critical mechanism for the expression of LTP and hippocampal learning. Since AMPAR surface diffusion is dictated by weak Brownian forces that are readily perturbed by protein-protein interactions, we anticipate that this fundamental trafficking mechanism will be a key target for modulating synaptic potentiation and learning.
Collapse
|
74
|
De Mario A, Peggion C, Massimino ML, Viviani F, Castellani A, Giacomello M, Lim D, Bertoli A, Sorgato MC. The prion protein regulates glutamate-mediated Ca 2+ entry and mitochondrial Ca 2+ accumulation in neurons. J Cell Sci 2017; 130:2736-2746. [PMID: 28701513 DOI: 10.1242/jcs.196972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 07/05/2017] [Indexed: 01/01/2023] Open
Abstract
The cellular prion protein (PrPC) whose conformational misfolding leads to the production of deadly prions, has a still-unclarified cellular function despite decades of intensive research. Following our recent finding that PrPC limits Ca2+ entry via store-operated Ca2+ channels in neurons, we investigated whether the protein could also control the activity of ionotropic glutamate receptors (iGluRs). To this end, we compared local Ca2+ movements in primary cerebellar granule neurons and cortical neurons transduced with genetically encoded Ca2+ probes and expressing, or not expressing, PrPC Our investigation demonstrated that PrPC downregulates Ca2+ entry through each specific agonist-stimulated iGluR and after stimulation by glutamate. We found that, although PrP-knockout (KO) mitochondria were displaced from the plasma membrane, glutamate addition resulted in a higher mitochondrial Ca2+ uptake in PrP-KO neurons than in their PrPC-expressing counterpart. This was because the increased Ca2+ entry through iGluRs in PrP-KO neurons led to a parallel increase in Ca2+-induced Ca2+ release via ryanodine receptor channels. These data thus suggest that PrPC takes part in the cell apparatus controlling Ca2+ homeostasis, and that PrPC is involved in protecting neurons from toxic Ca2+ overloads.
Collapse
Affiliation(s)
- Agnese De Mario
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Caterina Peggion
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Maria Lina Massimino
- CNR Neuroscience Institute, Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Francesca Viviani
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Angela Castellani
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Marta Giacomello
- Department of Biology, University of Padova, 35131 Padova, Italy
| | - Dmitry Lim
- Department of Pharmaceutical Science, University of Piemonte Orientale, 28100 Novara, Italy
| | - Alessandro Bertoli
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Maria Catia Sorgato
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy .,CNR Neuroscience Institute, Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| |
Collapse
|
75
|
Lameth J, Gervais A, Colin C, Lévêque P, Jay TM, Edeline JM, Mallat M. Acute Neuroinflammation Promotes Cell Responses to 1800 MHz GSM Electromagnetic Fields in the Rat Cerebral Cortex. Neurotox Res 2017; 32:444-459. [PMID: 28578480 DOI: 10.1007/s12640-017-9756-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/16/2017] [Accepted: 05/19/2017] [Indexed: 01/08/2023]
Abstract
Mobile phone communications are conveyed by radiofrequency (RF) electromagnetic fields, including pulse-modulated global system for mobile communications (GSM)-1800 MHz, whose effects on the CNS affected by pathological states remain to be specified. Here, we investigated whether a 2-h head-only exposure to GSM-1800 MHz could impact on a neuroinflammatory reaction triggered by lipopolysaccharide (LPS) in 2-week-old or adult rats. We focused on the cerebral cortex in which the specific absorption rate (SAR) of RF averaged 2.9 W/kg. In developing rats, 24 h after GSM exposure, the levels of cortical interleukin-1ß (IL1ß) or NOX2 NADPH oxidase transcripts were reduced by 50 to 60%, in comparison with sham-exposed animals (SAR = 0), as assessed by RT-qPCR. Adult rats exposed to GSM also showed a 50% reduction in the level of IL1ß mRNA, but they differed from developing rats by the lack of NOX2 gene suppression and by displaying a significant growth response of microglial cell processes imaged in anti-Iba1-stained cortical sections. As neuroinflammation is often associated with changes in excitatory neurotransmission, we evaluated changes in expression and phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the adult cerebral cortex by Western blot analyses. We found that GSM exposure decreased phosphorylation at two residues on the GluA1 AMPAR subunit (serine 831 and 845). The GSM-induced changes in gene expressions, microglia, and GluA1 phosphorylation did not persist 72 h after RF exposure and were not observed in the absence of LPS pretreatment. Together, our data provide evidence that GSM-1800 MHz can modulate CNS cell responses triggered by an acute neuroinflammatory state.
Collapse
Affiliation(s)
- Julie Lameth
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Annie Gervais
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Catherine Colin
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Philippe Lévêque
- Université de Limoges, CNRS, XLIM, UMR 7252, 123 avenue Albert Thomas, F-87000, Limoges, France
| | - Thérèse M Jay
- Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR_S894 INSERM, Université Paris Descartes, 102-108 rue de la Santé, 75014, Paris, France
| | - Jean-Marc Edeline
- Paris Saclay Institute of Neuroscience, Neuro-PSI, UMR 9197 CNRS, Université Paris-Sud, 91405, Orsay cedex, France
| | - Michel Mallat
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France.
| |
Collapse
|
76
|
Guntupalli S, Jang SE, Zhu T, Huganir RL, Widagdo J, Anggono V. GluA1 subunit ubiquitination mediates amyloid-β-induced loss of surface α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. J Biol Chem 2017; 292:8186-8194. [PMID: 28377502 PMCID: PMC5437227 DOI: 10.1074/jbc.m116.774554] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/20/2017] [Indexed: 12/24/2022] Open
Abstract
The accumulation of soluble amyloid-β (Aβ) peptides produces profound neuronal changes in the brain during the pathogenesis of Alzheimer's disease. Excessive levels of Aβ disrupt excitatory synaptic transmission by promoting the removal of synaptic AMPA receptors (AMPARs), dendritic spine loss, and synaptic depression. Recently, activity-dependent ubiquitination of the GluA1 subunit has been shown to regulate the intracellular sorting of AMPARs toward late endosomes for degradation. However, whether this ubiquitin signaling pathway mediates Aβ-induced loss of surface AMPARs is unknown. In this study, we demonstrate that acute exposure of cultured neurons to soluble Aβ oligomers induces AMPAR ubiquitination concomitant with the removal of AMPARs from the plasma membrane. Importantly, expression of the GluA1 ubiquitin-deficient mutants inhibited the adverse effects of Aβ on the surface expression of AMPARs in neurons. Furthermore, we revealed the cross-talk between GluA1 ubiquitination and phosphorylation, in particular phosphorylation at Ser-845, which is crucial for AMPAR recycling and is known to be dephosphorylated in the presence of Aβ. Our data showed that the GluA1 ubiquitin-deficient mutant enhances GluA1 phosphorylation on Ser-845. Conversely, the GluA1 S845D phosphomimetic mutant reduced binding with Nedd4-1 and hence the ubiquitination of AMPARs. Importantly, the GluA1 S845D mutant also prevented Aβ-induced removal of surface AMPARs. Taken together, these findings provide the first demonstration of the dynamic cross-modulation of GluA1 ubiquitination and phosphorylation, a process that is perturbed by Aβ, in regulating the membrane sorting decision that ultimately determines the number of AMPARs on the cell surface.
Collapse
Affiliation(s)
- Sumasri Guntupalli
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Se Eun Jang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tianyi Zhu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Richard L Huganir
- Department of Neuroscience and Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.
| |
Collapse
|
77
|
Amin JB, Salussolia CL, Chan K, Regan MC, Dai J, Zhou HX, Furukawa H, Bowen ME, Wollmuth LP. Divergent roles of a peripheral transmembrane segment in AMPA and NMDA receptors. J Gen Physiol 2017; 149:661-680. [PMID: 28507080 PMCID: PMC5460951 DOI: 10.1085/jgp.201711762] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 05/01/2017] [Indexed: 11/20/2022] Open
Abstract
AMPA and NMDA receptors are ionotropic glutamate receptors that make fundamental contributions to synaptic activity in the brain in different ways. Amin et al. show that their respective M4 segments, located on the periphery of their pore domains, contribute to their functional diversity. Ionotropic glutamate receptors (iGluRs), including AMPA receptor (AMPAR) and NMDA receptor (NMDAR) subtypes, are ligand-gated ion channels that mediate signaling at the majority of excitatory synapses in the nervous system. The iGluR pore domain is structurally and evolutionarily related to an inverted two-transmembrane K+ channel. Peripheral to the pore domain in eukaryotic iGluRs is an additional transmembrane helix, the M4 segment, which interacts with the pore domain of a neighboring subunit. In AMPARs, the integrity of the alignment of a specific face of M4 with the adjacent pore domain is essential for receptor oligomerization. In contrast to AMPARs, NMDARs are obligate heterotetramers composed of two GluN1 and typically two GluN2 subunits. Here, to address the function of the M4 segments in NMDARs, we carry out a tryptophan scan of M4 in GluN1 and GluN2A subunits. Unlike AMPARs, the M4 segments in NMDAR subunits makes only a limited contribution to their biogenesis. However, the M4 segments in both NMDAR subunits are critical for receptor activation, with mutations at some positions, most notably at the extreme extracellular end, completely halting the gating process. Furthermore, although the AMPAR M4 makes a minimal contribution to receptor desensitization, the NMDAR M4 segments have robust and subunit-specific effects on desensitization. These findings reveal that the functional roles of the M4 segments in AMPARs and NMDARs have diverged in the course of their evolution and that the M4 segments in NMDARs may act as a transduction pathway for receptor modulation at synapses.
Collapse
Affiliation(s)
- Johansen B Amin
- Graduate Program in Cellular and Molecular Pharmacology, Stony Brook University, Stony Brook, NY 11794.,Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794.,Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794
| | - Catherine L Salussolia
- Department of Pediatrics, Pediatrics Residency Program, Stony Brook University, Stony Brook, NY 11794.,Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794
| | - Kelvin Chan
- Graduate Program in Neuroscience, Stony Brook University, Stony Brook, NY 11794.,Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794.,Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794
| | | | - Jian Dai
- Department of Physics, Florida State University, Tallahassee, FL 32306.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Huan-Xiang Zhou
- Department of Physics, Florida State University, Tallahassee, FL 32306.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Hiro Furukawa
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Mark E Bowen
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794
| | - Lonnie P Wollmuth
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794 .,Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794.,Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794
| |
Collapse
|
78
|
Caioli S, Severini C, Ciotti T, Florenzano F, Pimpinella D, Petrocchi Passeri P, Balboni G, Polisca P, Lattanzi R, Nisticò R, Negri L, Zona C. Prokineticin system modulation as a new target to counteract the amyloid beta toxicity induced by glutamatergic alterations in an in vitro model of Alzheimer's disease. Neuropharmacology 2017; 116:82-97. [DOI: 10.1016/j.neuropharm.2016.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 11/29/2016] [Accepted: 12/14/2016] [Indexed: 12/28/2022]
|
79
|
Sun Z, Zhang Y, Xue X, Niu R, Wang J. Maternal fluoride exposure during gestation and lactation decreased learning and memory ability, and glutamate receptor mRNA expressions of mouse pups. Hum Exp Toxicol 2017; 37:87-93. [PMID: 29187078 DOI: 10.1177/0960327117693067] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous investigations demonstrated that high fluoride (F) exposure may adversely affect the neurodevelopment and learning and memory ability. However, whether maternal F exposure during gestation and lactation can influence the learning, memory ability, and glutamate receptor expressions of offspring has not yet been elucidated. Hence, in the present study, maternal mice were exposed to F (25, 50, or 100 mg/L sodium fluoride (NaF) in drinking water) during gestation and lactation. Results showed that exposure to 100 mg/L NaF significantly enhanced the number of total arm entries and working memory errors of offspring in the radial arm maze test compared to the control group. However, no difference was observed in open-field behaviors. For the subtypes of glutamate receptors in hippocampus, expression of GluR2 mRNA was significantly reduced by 25, 50, and 100 mg/L NaF. Besides, F exposure also suppressed the expression of NR2A, NR2B, and mGluR2 mRNA levels in a dose-dependent manner, where NR2A was significantly suppressed by 50 mg/L NaF and NR2B and mGluR2 by 100 mg/L NaF. However, no significant changes were observed in GluR1 and mGluR5 mRNA expression levels. Collectively, these findings suggested that F can pass through the cord blood and breast milk and may have deleterious impact on learning and memory of the mouse pups, which was mediated by reduced mRNA expression of glutamate receptor subunits.
Collapse
Affiliation(s)
- Z Sun
- 1 College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, China.,2 Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, Taigu, Shanxi, China
| | - Y Zhang
- 1 College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, China
| | - X Xue
- 1 College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, China
| | - R Niu
- 1 College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, China.,2 Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, Taigu, Shanxi, China
| | - J Wang
- 1 College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, China.,2 Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, Taigu, Shanxi, China
| |
Collapse
|
80
|
Prouty EW, Waterhouse BD, Chandler DJ. Corticotropin releasing factor dose-dependently modulates excitatory synaptic transmission in the noradrenergic nucleus locus coeruleus. Eur J Neurosci 2017; 45:712-722. [PMID: 27973694 DOI: 10.1111/ejn.13501] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 01/19/2023]
Abstract
The noradrenergic nucleus locus coeruleus (LC) is critically involved in the stress response and receives afferent input from a number of corticotropin releasing factor (CRF) containing structures. Several in vivo and in vitro studies in rat have shown that CRF robustly increases the firing rate of LC neurons in a dose-dependent manner. While it is known that these increases are dependent on CRF receptor subtype 1 and mediated by effects of cAMP intracellular signaling cascades on potassium conductance, the impact of CRF on synaptic transmission within LC has not been clarified. In the present study, we used whole-cell patch clamp electrophysiology to assess how varying concentrations of bath-applied CRF affect AMPA-receptor dependent spontaneous excitatory post-synaptic currents (sEPSCs). Compared to vehicle, 10, 25, and 100 nm CRF had no significant effects on any sEPSC parameters. Fifty nanomolar CRF, however, significantly increased sEPSC amplitude, half-width, and charge transfer, while these measures were significantly decreased by 200 nm CRF. These observations suggest that stress may differentially affect ongoing excitatory synaptic transmission in LC depending on how much CRF is released from presynaptic terminals. Combined with the well-documented effects of CRF on membrane properties and spontaneous LC discharge, these observations may help explain how stress and CRF release are able to modulate the signal to noise ratio of LC neurons. These findings have implications for how stress affects the fidelity of signal transmission and information flow through LC and how it might impact norepinephrine release in the CNS.
Collapse
Affiliation(s)
- Eric W Prouty
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Barry D Waterhouse
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Daniel J Chandler
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ, 08084, USA
| |
Collapse
|
81
|
Mao LM, Wang JQ. Tyrosine phosphorylation of glutamate receptors by non-receptor tyrosine kinases: roles in depression-like behavior. NEUROTRANSMITTER (HOUSTON, TEX.) 2016; 3:e1118. [PMID: 26942227 PMCID: PMC4771189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Several key members of the non-receptor tyrosine kinase (nRTK) family are abundantly present within excitatory synapses in the mammalian brain. These neuron-enriched nRTKs interact with glutamate receptors and phosphorylate the receptors at tyrosine sites. The N-methyl-D-aspartate receptor is a direct substrate of nRTKs and has been extensively investigated in its phosphorylation responses to nRTKs. The α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor is the other glutamate receptor subtype that is subject to nRTK-mediated tyrosine phosphorylation. Recently, group I metabotropic glutamate receptors (mGluR1/5) were found to be sensitive to nRTKs. Robust tyrosine phosphorylation may occur in C-terminal tails of mGluR5. Tyrosine phosphorylation of glutamate receptors is either constitutive or induced activity-dependently by changing cellular and/or synaptic input. Through inducing tyrosine phosphorylation, nRTKs regulate trafficking, subcellular distribution, and function of modified receptors. Available data show that nRTK-glutamate receptor interactions and tyrosine phosphorylation of the receptors undergo drastic adaptations in mood disorders such as major depressive disorder. The remodeling of the nRTK-glutamate receptor interplay contributes to the long-lasting pathophysiology and symptomology of depression. This review summarizes the recent progress in tyrosine phosphorylation of glutamate receptors and analyzes the role of nRTKs in regulating glutamate receptors and depression-like behavior.
Collapse
Affiliation(s)
| | - John Q. Wang
- Correspondence to: John Q. Wang, Department of Basic Medical Science, University of Missouri-Kansas City, School of Medicine, 2411 Holmes Street, Kansas City, Missouri 64108, USA, Tel: (816) 235-1786; Fax: (816) 235-5574,
| |
Collapse
|
82
|
Li LJ, Hu R, Lujan B, Chen J, Zhang JJ, Nakano Y, Cui TY, Liao MX, Chen JC, Man HY, Feng H, Wan Q. Glycine Potentiates AMPA Receptor Function through Metabotropic Activation of GluN2A-Containing NMDA Receptors. Front Mol Neurosci 2016; 9:102. [PMID: 27807405 PMCID: PMC5069295 DOI: 10.3389/fnmol.2016.00102] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/29/2016] [Indexed: 11/13/2022] Open
Abstract
NMDA receptors are Ca2+-permeable ion channels. The activation of NMDA receptors requires agonist glutamate and co-agonist glycine. Recent evidence indicates that NMDA receptor also has metabotropic function. Here we report that in cultured mouse hippocampal neurons, glycine increases AMPA receptor-mediated currents independent of the channel activity of NMDA receptors and the activation of glycine receptors. The potentiation of AMPA receptor function by glycine is antagonized by the inhibition of ERK1/2. In the hippocampal neurons and in the HEK293 cells transfected with different combinations of NMDA receptors, glycine preferentially acts on GluN2A-containing NMDA receptors (GluN2ARs), but not GluN2B-containing NMDA receptors (GluN2BRs), to enhance ERK1/2 phosphorylation independent of the channel activity of GluN2ARs. Without requiring the channel activity of GluN2ARs, glycine increases AMPA receptor-mediated currents through GluN2ARs. Thus, these results reveal a metabotropic function of GluN2ARs in mediating glycine-induced potentiation of AMPA receptor function via ERK1/2 activation.
Collapse
Affiliation(s)
- Li-Jun Li
- Department of Physiology, Toronto Western Research Institute, School of Medicine, University of Toronto Toronto, Canada
| | - Rong Hu
- Department of Physiology and Cell Biology, University of Nevada School of MedicineReno, NV, USA; Department of Neurosurgery, Southwest HospitalChongqing, China
| | - Brendan Lujan
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Juan Chen
- Department of Neurology, Central Hospital of Wuhan Wuhan, China
| | - Jian-Jian Zhang
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of Medicine Wuhan, China
| | - Yasuko Nakano
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Tian-Yuan Cui
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Ming-Xia Liao
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Jin-Cao Chen
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of Medicine Wuhan, China
| | - Heng-Ye Man
- Department of Biology, Boston University Boston, MA, USA
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital Chongqing, China
| | - Qi Wan
- Department of Physiology, Toronto Western Research Institute, School of Medicine, University of TorontoToronto, Canada; Department of Physiology and Cell Biology, University of Nevada School of MedicineReno, NV, USA; Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of MedicineWuhan, China; Department of Physiology, School of Basic Medical Sciences, Wuhan University School of MedicineWuhan, China
| |
Collapse
|
83
|
Vogt J, Yang JW, Mobascher A, Cheng J, Li Y, Liu X, Baumgart J, Thalman C, Kirischuk S, Unichenko P, Horta G, Radyushkin K, Stroh A, Richers S, Sahragard N, Distler U, Tenzer S, Qiao L, Lieb K, Tüscher O, Binder H, Ferreiros N, Tegeder I, Morris AJ, Gropa S, Nürnberg P, Toliat MR, Winterer G, Luhmann HJ, Huai J, Nitsch R. Molecular cause and functional impact of altered synaptic lipid signaling due to a prg-1 gene SNP. EMBO Mol Med 2016; 8:25-38. [PMID: 26671989 PMCID: PMC4718157 DOI: 10.15252/emmm.201505677] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Loss of plasticity‐related gene 1 (PRG‐1), which regulates synaptic phospholipid signaling, leads to hyperexcitability via increased glutamate release altering excitation/inhibition (E/I) balance in cortical networks. A recently reported SNP in prg‐1 (R345T/mutPRG‐1) affects ~5 million European and US citizens in a monoallelic variant. Our studies show that this mutation leads to a loss‐of‐PRG‐1 function at the synapse due to its inability to control lysophosphatidic acid (LPA) levels via a cellular uptake mechanism which appears to depend on proper glycosylation altered by this SNP. PRG‐1+/− mice, which are animal correlates of human PRG‐1+/mut carriers, showed an altered cortical network function and stress‐related behavioral changes indicating altered resilience against psychiatric disorders. These could be reversed by modulation of phospholipid signaling via pharmacological inhibition of the LPA‐synthesizing molecule autotaxin. In line, EEG recordings in a human population‐based cohort revealed an E/I balance shift in monoallelic mutPRG‐1 carriers and an impaired sensory gating, which is regarded as an endophenotype of stress‐related mental disorders. Intervention into bioactive lipid signaling is thus a promising strategy to interfere with glutamate‐dependent symptoms in psychiatric diseases.
Collapse
Affiliation(s)
- Johannes Vogt
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Jenq-Wei Yang
- Institute for Physiology and Pathophysiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Arian Mobascher
- Department of Psychiatry and Psychotherapy, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Jin Cheng
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Yunbo Li
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Xingfeng Liu
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Jan Baumgart
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Carine Thalman
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Sergei Kirischuk
- Institute for Physiology and Pathophysiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Petr Unichenko
- Institute for Physiology and Pathophysiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Guilherme Horta
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Konstantin Radyushkin
- Focus Program Translational Neuroscience (FTN), University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Albrecht Stroh
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Sebastian Richers
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Nassim Sahragard
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Ute Distler
- Focus Program Translational Neuroscience (FTN), University Medical Center, Johannes Gutenberg-University, Mainz, Germany Institute for Immunology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute for Immunology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Lianyong Qiao
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Klaus Lieb
- Department of Psychiatry and Psychotherapy, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Oliver Tüscher
- Department of Psychiatry and Psychotherapy, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Harald Binder
- Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Nerea Ferreiros
- Institute of Clinical Pharmacology Goethe-University Hospital, Frankfurt am Main, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology Goethe-University Hospital, Frankfurt am Main, Germany
| | - Andrew J Morris
- Division of Cardiovascular Medicine, Gill Heart Institute, University of Kentucky, Lexington, KY, USA
| | - Sergiu Gropa
- Department of Neurology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Mohammad R Toliat
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Georg Winterer
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Heiko J Luhmann
- Institute for Physiology and Pathophysiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Jisen Huai
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Robert Nitsch
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| |
Collapse
|
84
|
Cho E, Park M. Palmitoylation in Alzheimers disease and other neurodegenerative diseases. Pharmacol Res 2016; 111:133-151. [DOI: 10.1016/j.phrs.2016.06.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/07/2016] [Accepted: 06/08/2016] [Indexed: 12/13/2022]
|
85
|
Zhuo M. Contribution of synaptic plasticity in the insular cortex to chronic pain. Neuroscience 2016; 338:220-229. [PMID: 27530697 DOI: 10.1016/j.neuroscience.2016.08.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 12/20/2022]
Abstract
Animal and human studies have consistently demonstrated that cortical regions are important for pain perception and pain-related emotional changes. Studies of the anterior cingulate cortex (ACC) have shown that adult cortical synapses can be modified after peripheral injuries, and long-term changes at synaptic level may contribute to long-lasting suffering in patients. It also explains why chronic pain is resistant to conventional analgesics that act by inhibiting synaptic transmission. Insular cortex (IC), another critical cortical area, is found to be highly plastic and can undergo long-term potentiation (LTP) after injury. Inhibiting IC LTP reduces behavioral sensitization caused by injury. LTP of glutamatergic transmission in pain related cortical areas serves as a key mechanism for chronic pain.
Collapse
Affiliation(s)
- Min Zhuo
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Center for Neuron and Disease, Frontier Institutes of Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China; Centre for the Study of Pain, University of Toronto, Ontario M5S 1A8, Canada.
| |
Collapse
|
86
|
Structural rearrangement of the intracellular domains during AMPA receptor activation. Proc Natl Acad Sci U S A 2016; 113:E3950-9. [PMID: 27313205 DOI: 10.1073/pnas.1601747113] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are ligand-gated ion channels that mediate the majority of fast excitatory neurotransmission in the central nervous system. Despite recent advances in structural studies of AMPARs, information about the specific conformational changes that underlie receptor function is lacking. Here, we used single and dual insertion of GFP variants at various positions in AMPAR subunits to enable measurements of conformational changes using fluorescence resonance energy transfer (FRET) in live cells. We produced dual CFP/YFP-tagged GluA2 subunit constructs that had normal activity and displayed intrareceptor FRET. We used fluorescence lifetime imaging microscopy (FLIM) in live HEK293 cells to determine distinct steady-state FRET efficiencies in the presence of different ligands, suggesting a dynamic picture of the resting state. Patch-clamp fluorometry of the double- and single-insert constructs showed that both the intracellular C-terminal domain (CTD) and the loop region between the M1 and M2 helices move during activation and the CTD is detached from the membrane. Our time-resolved measurements revealed unexpectedly complex fluorescence changes within these intracellular domains, providing clues as to how posttranslational modifications and receptor function interact.
Collapse
|
87
|
Abstract
AMPA receptors (AMPARs) are assemblies of four core subunits, GluA1-4, that mediate most fast excitatory neurotransmission. The component subunits determine the functional properties of AMPARs, and the prevailing view is that the subunit composition also determines AMPAR trafficking, which is dynamically regulated during development, synaptic plasticity and in response to neuronal stress in disease. Recently, the subunit dependence of AMPAR trafficking has been questioned, leading to a reappraisal of this field. In this Review, we discuss what is known, uncertain, conjectured and unknown about the roles of the individual subunits, and how they affect AMPAR assembly, trafficking and function under both normal and pathological conditions.
Collapse
|
88
|
Xue B, Chen EC, He N, Jin DZ, Mao LM, Wang JQ. Integrated regulation of AMPA glutamate receptor phosphorylation in the striatum by dopamine and acetylcholine. Neuropharmacology 2016; 112:57-65. [PMID: 27060412 DOI: 10.1016/j.neuropharm.2016.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 04/01/2016] [Accepted: 04/05/2016] [Indexed: 12/16/2022]
Abstract
Dopamine (DA) and acetylcholine (ACh) signals converge onto protein kinase A (PKA) in medium spiny neurons of the striatum to control cellular and synaptic activities of these neurons, although underlying molecular mechanisms are less clear. Here we measured phosphorylation of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) at a PKA site (S845) as an indicator of AMPAR responses in adult rat brains in vivo to explore how DA and ACh interact to modulate AMPARs. We found that subtype-selective activation of DA D1 receptors (D1Rs), D2 receptors (D2Rs), or muscarinic M4 receptors (M4Rs) induced specific patterns of GluA1 S845 responses in the striatum. These defined patterns support a local multitransmitter interaction model in which D2Rs inhibited an intrinsic inhibitory element mediated by M4Rs to enhance the D1R efficacy in modulating AMPARs. Consistent with this, selective enhancement of M4R activity by a positive allosteric modulator resumed the cholinergic inhibition of D1Rs. In addition, D1R and D2R coactivation recruited GluA1 and PKA preferentially to extrasynaptic sites. In sum, our in vivo data support an existence of a dynamic DA-ACh balance in the striatum which actively modulates GluA1 AMPAR phosphorylation and trafficking. This article is part of the Special Issue entitled 'Ionotropic glutamate receptors'.
Collapse
Affiliation(s)
- Bing Xue
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Elton C Chen
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Nan He
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Dao-Zhong Jin
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Li-Min Mao
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - John Q Wang
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA; Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA; Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China.
| |
Collapse
|
89
|
Guntupalli S, Widagdo J, Anggono V. Amyloid-β-Induced Dysregulation of AMPA Receptor Trafficking. Neural Plast 2016; 2016:3204519. [PMID: 27073700 PMCID: PMC4814684 DOI: 10.1155/2016/3204519] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 02/28/2016] [Indexed: 01/22/2023] Open
Abstract
Evidence from neuropathological, genetic, animal model, and biochemical studies has indicated that the accumulation of amyloid-beta (Aβ) is associated with, and probably induces, profound neuronal changes in brain regions critical for memory and cognition in the development of Alzheimer's disease (AD). There is considerable evidence that synapses are particularly vulnerable to AD, establishing synaptic dysfunction as one of the earliest events in pathogenesis, prior to neuronal loss. It is clear that excessive Aβ levels can disrupt excitatory synaptic transmission and plasticity, mainly due to dysregulation of the AMPA and NMDA glutamate receptors in the brain. Importantly, AMPA receptors are the principal glutamate receptors that mediate fast excitatory neurotransmission. This is essential for synaptic plasticity, a cellular correlate of learning and memory, which are the cognitive functions that are most disrupted in AD. Here we review recent advances in the field and provide insights into the molecular mechanisms that underlie Aβ-induced dysfunction of AMPA receptor trafficking. This review focuses primarily on NMDA receptor- and metabotropic glutamate receptor-mediated signaling. In particular, we highlight several mechanisms that underlie synaptic long-term depression as common signaling pathways that are hijacked by the neurotoxic effects of Aβ.
Collapse
Affiliation(s)
- Sumasri Guntupalli
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| |
Collapse
|
90
|
Babiec WE, Guglietta R, O'Dell TJ. Basal levels of AMPA receptor GluA1 subunit phosphorylation at threonine 840 and serine 845 in hippocampal neurons. ACTA ACUST UNITED AC 2016; 23:127-33. [PMID: 26980779 PMCID: PMC4793196 DOI: 10.1101/lm.040675.115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/12/2016] [Indexed: 01/19/2023]
Abstract
Dephosphorylation of AMPA receptor (AMPAR) GluA1 subunits at two sites, serine 845 (S845) and threonine 840 (T840), is thought to be involved in NMDA receptor-dependent forms of long-term depression (LTD). Importantly, the notion that dephosphorylation of these sites contributes to LTD assumes that a significant fraction of GluA1 subunits are basally phosphorylated at these sites. To examine this question, we used immunoprecipitation/depletion assays to estimate the proportion of GluA1 subunits basally phosphorylated at S845 and T840. Although dephosphorylation of S845 is thought to have a key role in LTD, our results indicate that few GluA1 subunits in hippocampal neurons are phosphorylated at this site. In contrast, ∼50% of GluA1 subunits are basally phosphorylated at T840, suggesting that dephosphorylation of this site can contribute to the down-regulation of AMPAR-mediated synaptic transmission in LTD.
Collapse
Affiliation(s)
- Walter E Babiec
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
| | - Ryan Guglietta
- Interdepartmental Ph.D. Program for Neuroscience at UCLA, Los Angeles, California 90095, USA
| | - Thomas J O'Dell
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA UCLA Integrative Center for Learning and Memory, Brain Research Institute, Los Angeles, California 90095, USA
| |
Collapse
|
91
|
Excitatory synapses are stronger in the hippocampus of Rett syndrome mice due to altered synaptic trafficking of AMPA-type glutamate receptors. Proc Natl Acad Sci U S A 2016; 113:E1575-84. [PMID: 26929363 DOI: 10.1073/pnas.1517244113] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Deficits in long-term potentiation (LTP) at central excitatory synapses are thought to contribute to cognitive impairments in neurodevelopmental disorders associated with intellectual disability and autism. Using the methyl-CpG-binding protein 2 (Mecp2) knockout (KO) mouse model of Rett syndrome, we show that naïve excitatory synapses onto hippocampal pyramidal neurons of symptomatic mice have all of the hallmarks of potentiated synapses. Stronger Mecp2 KO synapses failed to undergo LTP after either theta-burst afferent stimulation or pairing afferent stimulation with postsynaptic depolarization. On the other hand, basal synaptic strength and LTP were not affected in slices from younger presymptomatic Mecp2 KO mice. Furthermore, spine synapses in pyramidal neurons from symptomatic Mecp2 KO are larger and do not grow in size or incorporate GluA1 subunits after electrical or chemical LTP. Our data suggest that LTP is occluded in Mecp2 KO mice by already potentiated synapses. The higher surface levels of GluA1-containing receptors are consistent with altered expression levels of proteins involved in AMPA receptor trafficking, suggesting previously unidentified targets for therapeutic intervention for Rett syndrome and other MECP2-related disorders.
Collapse
|
92
|
Activation of α7 nicotinic acetylcholine receptors protects potentiated synapses from depotentiation during theta pattern stimulation in the hippocampal CA1 region of rats. Neuropharmacology 2016; 105:378-387. [PMID: 26867505 DOI: 10.1016/j.neuropharm.2016.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/24/2016] [Accepted: 02/05/2016] [Indexed: 11/21/2022]
Abstract
Long-term potentiation (LTP) shows memory-like consolidation and thus becomes increasingly resistant to disruption by low-frequency stimulation (LFS). However, it is known that nicotine application during LFS uniquely depotentiates consolidated LTP. Here, we investigated how nicotine contributes to the disruption of stabilized LTP in the hippocampal CA1 region. We found that nicotine-induced depotentiation is not due to masking LTP by inducing long-term depression and requires the activation of GluN2A-containing NMDARs. We further examined whether nicotine-induced depotentiation involves the reversal of LTP mechanisms. LTP causes phosphorylation of Ser-831 on GluA1 subunits of AMPARs that increases the single-channel conductance of AMPARs. This phosphorylation remained unchanged after depotentiation. LTP involves the insertion of new AMPARs into the synapse and the internalization of AMPARs is associated with dephosphorylation of Ser-845 on GluA1 and caspase-3 activity. Nicotine-induced depotentiation occurred without dephosphorylation of the Ser-845 and in the presence of a caspase-3 inhibitor. LTP is also accompanied by increased filamentous actin (F-actin), which controls spine size. Nicotine-induced depotentiation was prevented by jasplakinolide, which stabilizes F-actin, suggesting that nicotine depotentiates consolidated LTP by destabilizing F-actin. α7 nicotinic acetylcholine receptor (nAChR) antagonists mimicked the effect of nicotine and selective removal of hippocampal cholinergic input caused depotentiation in the absence of nicotine, suggesting that nicotine depotentiates consolidated LTP by inducing α7 nAChR desensitization. Our results demonstrate a new role for nicotinic cholinergic systems in protecting potentiated synapses from depotentiation by preventing GluN2A-NMDAR-mediated signaling for actin destabilization.
Collapse
|
93
|
Acute Footshock Stress Induces Time-Dependent Modifications of AMPA/NMDA Protein Expression and AMPA Phosphorylation. Neural Plast 2016; 2016:7267865. [PMID: 26966584 PMCID: PMC4757710 DOI: 10.1155/2016/7267865] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/21/2015] [Accepted: 01/10/2016] [Indexed: 12/04/2022] Open
Abstract
Clinical studies on patients with stress-related neuropsychiatric disorders reported functional and morphological changes in brain areas where glutamatergic transmission is predominant, including frontal and prefrontal areas. In line with this evidence, several preclinical works suggest that glutamate receptors are targets of both rapid and long-lasting effects of stress. Here we found that acute footshock- (FS-) stress, although inducing no transcriptional and RNA editing alterations of ionotropic AMPA and NMDA glutamate receptor subunits, rapidly and transiently modulates their protein expression, phosphorylation, and localization at postsynaptic spines in prefrontal and frontal cortex. In total extract, FS-stress increased the phosphorylation levels of GluA1 AMPA subunit at Ser845 immediately after stress and of GluA2 Ser880 2 h after start of stress. At postsynaptic spines, stress induced a rapid decrease of GluA2 expression, together with an increase of its phosphorylation at Ser880, suggesting internalization of GluA2 AMPA containing receptors. GluN1 and GluN2A NMDA receptor subunits were found markedly upregulated in postsynaptic spines, 2 h after start of stress. These results suggest selected time-dependent changes in glutamatergic receptor subunits induced by acute stress, which may suggest early and transient enhancement of AMPA-mediated currents, followed by a transient activation of NMDA receptors.
Collapse
|
94
|
PSD-Zip70 Deficiency Causes Prefrontal Hypofunction Associated with Glutamatergic Synapse Maturation Defects by Dysregulation of Rap2 Activity. J Neurosci 2016; 35:14327-40. [PMID: 26490870 DOI: 10.1523/jneurosci.2349-15.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Dysregulation of synapse formation and plasticity is closely related to the pathophysiology of psychiatric and neurodevelopmental disorders. The prefrontal cortex (PFC) is particularly important for executive functions such as working memory, cognition, and emotional control, which are impaired in the disorders. PSD-Zip70 (Lzts1/FEZ1) is a postsynaptic density (PSD) protein predominantly expressed in the frontal cortex, olfactory bulb, striatum, and hippocampus. Here we found that PSD-Zip70 knock-out (PSD-Zip70KO) mice exhibit working memory and cognitive defects, and enhanced anxiety-like behaviors. These abnormal behaviors are caused by impaired glutamatergic synapse transmission accompanied by tiny-headed immature dendritic spines in the PFC, due to aberrant Rap2 activation, which has roles in synapse formation and plasticity. PSD-Zip70 modulates the Rap2 activity by interacting with SPAR (spine-associated RapGAP) and PDZ-GEF1 (RapGEF) in the postsynapse. Furthermore, suppression of the aberrant Rap2 activation in the PFC rescued the behavioral defects in PSD-Zip70KO mice. Our data demonstrate a critical role for PSD-Zip70 in Rap2-dependent spine synapse development in the PFC and underscore the importance of this regulation in PFC-dependent behaviors. SIGNIFICANCE STATEMENT PSD-Zip70 deficiency causes behavioral defects in working memory and cognition, and enhanced anxiety due to prefrontal hypofunction. This study revealed that PSD-Zip70 plays essential roles in glutamatergic synapse maturation via modulation of the Rap2 activity in the PFC. PSD-Zip70 interacts with both SPAR (spine-associated RapGAP) and PDZ-GEF1 (RapGEF) and modulates the Rap2 activity in postsynaptic sites. Our results provide a novel Rap2-specific regulatory mechanism in synaptic maturation involving PSD-Zip70.
Collapse
|
95
|
Ghosh S, Reuveni I, Barkai E, Lamprecht R. Calcium/calmodulin-dependent kinase II activity is required for maintaining learning-induced enhancement of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated synaptic excitation. J Neurochem 2016; 136:1168-1176. [DOI: 10.1111/jnc.13505] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/20/2015] [Accepted: 12/15/2015] [Indexed: 01/31/2023]
Affiliation(s)
- Sourav Ghosh
- Sagol Department of Neurobiology; Faculty of Natural Sciences; University of Haifa; Haifa Israel
| | - Iris Reuveni
- Sagol Department of Neurobiology; Faculty of Natural Sciences; University of Haifa; Haifa Israel
| | - Edi Barkai
- Sagol Department of Neurobiology; Faculty of Natural Sciences; University of Haifa; Haifa Israel
| | - Raphael Lamprecht
- Sagol Department of Neurobiology; Faculty of Natural Sciences; University of Haifa; Haifa Israel
| |
Collapse
|
96
|
Wang Y, Zhou Z, Leylek T, Tan H, Sun Y, Parkinson F, Wang JF. Protein cysteine S-nitrosylation inhibits vesicular uptake of neurotransmitters. Neuroscience 2015; 311:374-81. [DOI: 10.1016/j.neuroscience.2015.10.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/25/2015] [Accepted: 10/28/2015] [Indexed: 12/31/2022]
|
97
|
Park H, Yang J, Kim R, Li Y, Lee Y, Lee C, Park J, Lee D, Kim H, Kim E. Mice lacking the PSD-95-interacting E3 ligase, Dorfin/Rnf19a, display reduced adult neurogenesis, enhanced long-term potentiation, and impaired contextual fear conditioning. Sci Rep 2015; 5:16410. [PMID: 26553645 PMCID: PMC4639748 DOI: 10.1038/srep16410] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/14/2015] [Indexed: 11/09/2022] Open
Abstract
Protein ubiquitination has a significant influence on diverse aspects of neuronal development and function. Dorfin, also known as Rnf19a, is a RING finger E3 ubiquitin ligase implicated in amyotrophic lateral sclerosis and Parkinson's disease, but its in vivo functions have not been explored. We report here that Dorfin is a novel binding partner of the excitatory postsynaptic scaffolding protein PSD-95. Dorfin-mutant (Dorfin(-/-)) mice show reduced adult neurogenesis and enhanced long-term potentiation in the hippocampal dentate gyrus, but normal long-term potentiation in the CA1 region. Behaviorally, Dorfin(-/-) mice show impaired contextual fear conditioning, but normal levels of cued fear conditioning, fear extinction, spatial learning and memory, object recognition memory, spatial working memory, and pattern separation. Using a proteomic approach, we also identify a number of proteins whose ubiquitination levels are decreased in the Dorfin(-/-) brain. These results suggest that Dorfin may regulate adult neurogenesis, synaptic plasticity, and contextual fear memory.
Collapse
Affiliation(s)
- Hanwool Park
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Jinhee Yang
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Ryunhee Kim
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Yan Li
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Yeunkum Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Chungwoo Lee
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Jongil Park
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea
| | - Dongmin Lee
- Department of Anatomy and Division of Brain Korea 21. Biomedical Science, College of Medicine, Korea University, Seoul 136-704, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21. Biomedical Science, College of Medicine, Korea University, Seoul 136-704, Korea
| | - Eunjoon Kim
- Department of Biological Sciences, KAIST, Daejeon 305-701, Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| |
Collapse
|
98
|
Goo MS, Scudder SL, Patrick GN. Ubiquitin-dependent trafficking and turnover of ionotropic glutamate receptors. Front Mol Neurosci 2015; 8:60. [PMID: 26528125 PMCID: PMC4607782 DOI: 10.3389/fnmol.2015.00060] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/22/2015] [Indexed: 12/19/2022] Open
Abstract
Changes in synaptic strength underlie the basis of learning and memory and are controlled, in part, by the insertion or removal of AMPA-type glutamate receptors at the postsynaptic membrane of excitatory synapses. Once internalized, these receptors may be recycled back to the plasma membrane by subunit-specific interactions with other proteins or by post-translational modifications such as phosphorylation. Alternatively, these receptors may be targeted for destruction by multiple degradation pathways in the cell. Ubiquitination, another post-translational modification, has recently emerged as a key signal that regulates the recycling and trafficking of glutamate receptors. In this review, we will discuss recent findings on the role of ubiquitination in the trafficking and turnover of ionotropic glutamate receptors and plasticity of excitatory synapses.
Collapse
Affiliation(s)
- Marisa S Goo
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Samantha L Scudder
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Gentry N Patrick
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
99
|
Regulation of AMPA receptor subunit GluA1 surface expression by PAK3 phosphorylation. Proc Natl Acad Sci U S A 2015; 112:E5883-90. [PMID: 26460013 DOI: 10.1073/pnas.1518382112] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
AMPA receptors (AMPARs) are the major excitatory receptors of the brain and are fundamental to synaptic plasticity, memory, and cognition. Dynamic recycling of AMPARs in neurons is regulated through several types of posttranslational modification, including phosphorylation. Here, we identify a previously unidentified signal transduction cascade that modulates phosphorylation of serine residue 863 (S863) in the GluA1 AMPAR subunit and controls surface trafficking of GluA1 in neurons. Activation of the EphR-Ephrin signal transduction pathway enhances S863 phosphorylation. Further, EphB2 can interact with Zizimin1, a guanine-nucleotide exchange factor that activates Cdc42 and stimulates S863 phosphorylation in neurons. Among the numerous targets downstream of Cdc42, we determined that the p21-activated kinase-3 (PAK3) phosphorylates S863 in vitro. Moreover, specific loss of PAK3 expression and pharmacological inhibition of PAK both disrupt activity-dependent phosphorylation of S863 in cortical neurons. EphB2, Cdc42, and PAKs are broadly capable of controlling dendritic spine formation and synaptic plasticity and are implicated in multiple cognitive disorders. Collectively, these data delineate a novel signal cascade regulating AMPAR trafficking that may contribute to the molecular mechanisms that govern learning and cognition.
Collapse
|
100
|
Woolfrey KM, Dell'Acqua ML. Coordination of Protein Phosphorylation and Dephosphorylation in Synaptic Plasticity. J Biol Chem 2015; 290:28604-12. [PMID: 26453308 DOI: 10.1074/jbc.r115.657262] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A central theme in nervous system function is equilibrium: synaptic strengths wax and wane, neuronal firing rates adjust up and down, and neural circuits balance excitation with inhibition. This push/pull regulatory theme carries through to the molecular level at excitatory synapses, where protein function is controlled through phosphorylation and dephosphorylation by kinases and phosphatases. However, these opposing enzymatic activities are only part of the equation as scaffolding interactions and assembly of multi-protein complexes are further required for efficient, localized synaptic signaling. This review will focus on coordination of postsynaptic serine/threonine kinase and phosphatase signaling by scaffold proteins during synaptic plasticity.
Collapse
Affiliation(s)
- Kevin M Woolfrey
- From the Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado 80045
| | - Mark L Dell'Acqua
- From the Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado 80045
| |
Collapse
|