1
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Yakout DW, Shroff A, Wei W, Thaker V, Allen ZD, Sajish M, Nazarko TY, Mabb AM. Tau regulates Arc stability in neuronal dendrites via a proteasome-sensitive but ubiquitin-independent pathway. J Biol Chem 2024; 300:107237. [PMID: 38552740 PMCID: PMC11061231 DOI: 10.1016/j.jbc.2024.107237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 02/23/2024] [Accepted: 03/19/2024] [Indexed: 04/26/2024] Open
Abstract
Tauopathies are neurodegenerative disorders characterized by the deposition of aggregates of the microtubule-associated protein tau, a main component of neurofibrillary tangles. Alzheimer's disease (AD) is the most common type of tauopathy and dementia, with amyloid-beta pathology as an additional hallmark feature of the disease. Besides its role in stabilizing microtubules, tau is localized at postsynaptic sites and can regulate synaptic plasticity. The activity-regulated cytoskeleton-associated protein (Arc) is an immediate early gene that plays a key role in synaptic plasticity, learning, and memory. Arc has been implicated in AD pathogenesis and regulates the release of amyloid-beta. We found that decreased Arc levels correlate with AD status and disease severity. Importantly, Arc protein was upregulated in the hippocampus of Tau KO mice and dendrites of Tau KO primary hippocampal neurons. Overexpression of tau decreased Arc stability in an activity-dependent manner, exclusively in neuronal dendrites, which was coupled to an increase in the expression of dendritic and somatic surface GluA1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. The tau-dependent decrease in Arc was found to be proteasome-sensitive, yet independent of Arc ubiquitination and required the endophilin-binding domain of Arc. Importantly, these effects on Arc stability and GluA1 localization were not observed in the commonly studied tau mutant, P301L. These observations provide a potential molecular basis for synaptic dysfunction mediated through the accumulation of tau in dendrites. Our findings confirm that Arc is misregulated in AD and further show a physiological role for tau in regulating Arc stability and AMPA receptor targeting.
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Affiliation(s)
- Dina W Yakout
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Ankit Shroff
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Wei Wei
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Vishrut Thaker
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Zachary D Allen
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Mathew Sajish
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina, USA
| | - Taras Y Nazarko
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Angela M Mabb
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA; Center for Behavioral Neuroscience, Georgia State University, Atlanta, Georgia, USA.
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2
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Ung DC, Pietrancosta N, Badillo EB, Raux B, Tapken D, Zlatanovic A, Doridant A, Pode-Shakked B, Raas-Rothschild A, Elpeleg O, Abu-Libdeh B, Hamed N, Papon MA, Marouillat S, Thépault RA, Stevanin G, Elegheert J, Letellier M, Hollmann M, Lambolez B, Tricoire L, Toutain A, Hepp R, Laumonnier F. GRID1/GluD1 homozygous variants linked to intellectual disability and spastic paraplegia impair mGlu1/5 receptor signaling and excitatory synapses. Mol Psychiatry 2024; 29:1205-1215. [PMID: 38418578 PMCID: PMC11176079 DOI: 10.1038/s41380-024-02469-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 03/01/2024]
Abstract
The ionotropic glutamate delta receptor GluD1, encoded by the GRID1 gene, is involved in synapse formation, function, and plasticity. GluD1 does not bind glutamate, but instead cerebellin and D-serine, which allow the formation of trans-synaptic bridges, and trigger transmembrane signaling. Despite wide expression in the nervous system, pathogenic GRID1 variants have not been characterized in humans so far. We report homozygous missense GRID1 variants in five individuals from two unrelated consanguineous families presenting with intellectual disability and spastic paraplegia, without (p.Thr752Met) or with (p.Arg161His) diagnosis of glaucoma, a threefold phenotypic association whose genetic bases had not been elucidated previously. Molecular modeling and electrophysiological recordings indicated that Arg161His and Thr752Met mutations alter the hinge between GluD1 cerebellin and D-serine binding domains and the function of this latter domain, respectively. Expression, trafficking, physical interaction with metabotropic glutamate receptor mGlu1, and cerebellin binding of GluD1 mutants were not conspicuously altered. Conversely, upon expression in neurons of dissociated or organotypic slice cultures, we found that both GluD1 mutants hampered metabotropic glutamate receptor mGlu1/5 signaling via Ca2+ and the ERK pathway and impaired dendrite morphology and excitatory synapse density. These results show that the clinical phenotypes are distinct entities segregating in the families as an autosomal recessive trait, and caused by pathophysiological effects of GluD1 mutants involving metabotropic glutamate receptor signaling and neuronal connectivity. Our findings unravel the importance of GluD1 receptor signaling in sensory, cognitive and motor functions of the human nervous system.
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Affiliation(s)
- Dévina C Ung
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France
| | - Nicolas Pietrancosta
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
- Laboratoire des biomolécules, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | | | - Brigitt Raux
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Daniel Tapken
- Department of Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Andjela Zlatanovic
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Adrien Doridant
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Ben Pode-Shakked
- The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
- Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, 5262000, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Annick Raas-Rothschild
- The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bassam Abu-Libdeh
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Jerusalem, Palestine
| | - Nasrin Hamed
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
| | | | | | | | - Giovanni Stevanin
- Univ. Bordeaux, INCIA, UMR 5287 CNRS EPHE, F-33000, Bordeaux, France
| | | | | | - Michael Hollmann
- Department of Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Bertrand Lambolez
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Ludovic Tricoire
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Annick Toutain
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France.
- Unité fonctionnelle de Génétique Médicale, Centre Hospitalier Universitaire, 37044, Tours, France.
| | - Régine Hepp
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France.
| | - Frédéric Laumonnier
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France.
- Service de Génétique, Centre Hospitalier Universitaire, 37044, Tours, France.
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3
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Filannino FM, Panaro MA, Benameur T, Pizzolorusso I, Porro C. Extracellular Vesicles in the Central Nervous System: A Novel Mechanism of Neuronal Cell Communication. Int J Mol Sci 2024; 25:1629. [PMID: 38338906 PMCID: PMC10855168 DOI: 10.3390/ijms25031629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/21/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
Cell-to-cell communication is essential for the appropriate development and maintenance of homeostatic conditions in the central nervous system. Extracellular vesicles have recently come to the forefront of neuroscience as novel vehicles for the transfer of complex signals between neuronal cells. Extracellular vesicles are membrane-bound carriers packed with proteins, metabolites, and nucleic acids (including DNA, mRNA, and microRNAs) that contain the elements present in the cell they originate from. Since their discovery, extracellular vesicles have been studied extensively and have opened up new understanding of cell-cell communication; they may cross the blood-brain barrier in a bidirectional way from the bloodstream to the brain parenchyma and vice versa, and play a key role in brain-periphery communication in physiology as well as pathology. Neurons and glial cells in the central nervous system release extracellular vesicles to the interstitial fluid of the brain and spinal cord parenchyma. Extracellular vesicles contain proteins, nucleic acids, lipids, carbohydrates, and primary and secondary metabolites. that can be taken up by and modulate the behaviour of neighbouring recipient cells. The functions of extracellular vesicles have been extensively studied in the context of neurodegenerative diseases. The purpose of this review is to analyse the role extracellular vesicles extracellular vesicles in central nervous system cell communication, with particular emphasis on the contribution of extracellular vesicles from different central nervous system cell types in maintaining or altering central nervous system homeostasis.
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Affiliation(s)
| | - Maria Antonietta Panaro
- Department of Biosciences, Biotechnologies and Environment, University of Bari, 70125 Bari, Italy;
| | - Tarek Benameur
- Department of Biomedical Sciences, College of Medicine, King Faisal University, Al-Ahsa 31982, Saudi Arabia;
| | - Ilaria Pizzolorusso
- Child and Adolescent Neuropsychiatry Unit, Department of Mental Health, ASL Foggia, 71121 Foggia, Italy;
| | - Chiara Porro
- Department of Clinical and Experimental Medicine, University of Foggia, 71121 Foggia, Italy;
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4
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Haley M, Bertrand J, Anderson VT, Fuad M, Frenguelli BG, Corrêa SAL, Wall MJ. Arc expression regulates long-term potentiation magnitude and metaplasticity in area CA1 of the hippocampus in ArcKR mice. Eur J Neurosci 2023; 58:4166-4180. [PMID: 37821126 DOI: 10.1111/ejn.16172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/18/2023] [Accepted: 09/26/2023] [Indexed: 10/13/2023]
Abstract
Expression of the immediate early gene Arc/Arg3.1 (Arc), a key mediator of synaptic plasticity, is enhanced by neural activity and then reduced by proteasome-dependent degradation. We have previously shown that the disruption of Arc degradation, in an Arc knock-in mouse (ArcKR), where the predominant Arc ubiquitination sites were mutated, reduced the threshold to induce, and also enhanced, the strength of Group I metabotropic glutamate receptor-mediated long-term depression (DHPG-LTD). Here, we have investigated if ArcKR expression changes long-term potentiation (LTP) in CA1 area of the hippocampus. As previously reported, there was no change in basal synaptic transmission at Schaffer collateral/commissural-CA1 (SC-CA1) synapses in ArcKR versus wild-type (WT) mice. There was, however, a significant increase in the amplitude of synaptically induced (with low frequency paired-pulse stimulation) LTD in ArcKR mice. Theta burst stimulation (TBS)-evoked LTP at SC-CA1 synapses was significantly reduced in ArcKR versus WT mice (after 2 h). Group 1 mGluR priming of LTP was abolished in ArcKR mice, which could also potentially contribute to a depression of LTP. Although high frequency stimulation (HFS)-induced LTP was not significantly different in ArcKR compared with WT mice (after 1 h), there was a phenotype in environmentally enriched mice, with the ratio of LTP to short-term potentiation (STP) significantly reduced in ArcKR mice. These findings support the hypothesis that Arc ubiquitination supports the induction and expression of LTP, likely via limiting Arc-dependent removal of AMPA receptors at synapses.
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Affiliation(s)
- Maisy Haley
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Jeanri Bertrand
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | - Mukattar Fuad
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | - Sonia A L Corrêa
- Faculty of Science and Engineering, Department of Life Sciences, John Dalton Building, Room E210, Manchester Metropolitan University, Manchester, UK
| | - Mark J Wall
- School of Life Sciences, University of Warwick, Coventry, UK
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5
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Jong YJI, Izumi Y, Harmon SK, Zorumski CF, ÓMalley KL. Striatal mGlu 5-mediated synaptic plasticity is independently regulated by location-specific receptor pools and divergent signaling pathways. J Biol Chem 2023; 299:104949. [PMID: 37354970 PMCID: PMC10388212 DOI: 10.1016/j.jbc.2023.104949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/26/2023] Open
Abstract
Metabotropic glutamate receptor 5 (mGlu5) is widely expressed throughout the central nervous system and is involved in neuronal function, synaptic transmission, and a number of neuropsychiatric disorders such as depression, anxiety, and autism. Recent work from this lab showed that mGlu5 is one of a growing number of G protein-coupled receptors that can signal from intracellular membranes where it drives unique signaling pathways, including upregulation of extracellular signal-regulated kinase (ERK1/2), ETS transcription factor Elk-1, and activity-regulated cytoskeleton-associated protein (Arc). To determine the roles of cell surface mGlu5 as well as the intracellular receptor in a well-known mGlu5 synaptic plasticity model such as long-term depression, we used pharmacological isolation and genetic and physiological approaches to analyze spatially restricted pools of mGlu5 in striatal cultures and slice preparations. Here we show that both intracellular and cell surface receptors activate the phosphatidylinositol-3-kinase-protein kinase B-mammalian target of rapamycin (PI3K/AKT/mTOR) pathway, whereas only intracellular mGlu5 activates protein phosphatase 2 and leads to fragile X mental retardation protein degradation and de novo protein synthesis followed by a protein synthesis-dependent increase in Arc and post-synaptic density protein 95. However, both cell surface and intracellular mGlu5 activation lead to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor GluA2 internalization and chemically induced long-term depression albeit via different signaling mechanisms. These data underscore the importance of intracellular mGlu5 in the cascade of events associated with sustained synaptic transmission in the striatum.
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Affiliation(s)
- Yuh-Jiin I Jong
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA
| | - Yukitoshi Izumi
- Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St Louis, Missouri, USA
| | - Steven K Harmon
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA
| | - Charles F Zorumski
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA; Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St Louis, Missouri, USA
| | - Karen L ÓMalley
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA.
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6
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Sibarov DA, Tsytsarev V, Volnova A, Vaganova AN, Alves J, Rojas L, Sanabria P, Ignashchenkova A, Savage ED, Inyushin M. Arc protein, a remnant of ancient retrovirus, forms virus-like particles, which are abundantly generated by neurons during epileptic seizures, and affects epileptic susceptibility in rodent models. Front Neurol 2023; 14:1201104. [PMID: 37483450 PMCID: PMC10361770 DOI: 10.3389/fneur.2023.1201104] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/02/2023] [Indexed: 07/25/2023] Open
Abstract
A product of the immediate early gene Arc (Activity-regulated cytoskeleton-associated protein or Arc protein) of retroviral ancestry resides in the genome of all tetrapods for millions of years and is expressed endogenously in neurons. It is a well-known protein, very important for synaptic plasticity and memory consolidation. Activity-dependent Arc expression concentrated in glutamatergic synapses affects the long-time synaptic strength of those excitatory synapses. Because it modulates excitatory-inhibitory balance in a neuronal network, the Arc gene itself was found to be related to the pathogenesis of epilepsy. General Arc knockout rodent models develop a susceptibility to epileptic seizures. Because of activity dependence, synaptic Arc protein synthesis also is affected by seizures. Interestingly, it was found that Arc protein in synapses of active neurons self-assemble in capsids of retrovirus-like particles, which can transfer genetic information between neurons, at least across neuronal synaptic boutons. Released Arc particles can be accumulated in astrocytes after seizures. It is still not known how capsid assembling and transmission timescale is affected by seizures. This scientific field is relatively novel and is experiencing swift transformation as it grapples with difficult concepts in light of evolving experimental findings. We summarize the emergent literature on the subject and also discuss the specific rodent models for studying Arc effects in epilepsy. We summarized both to clarify the possible role of Arc-related pseudo-viral particles in epileptic disorders, which may be helpful to researchers interested in this growing area of investigation.
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Affiliation(s)
- Dmitry A. Sibarov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anna Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Anastasia N. Vaganova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Janaina Alves
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Legier Rojas
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Priscila Sanabria
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | | | | | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
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7
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Ghane MA, Wei W, Yakout DW, Allen ZD, Miller CL, Dong B, Yang JJ, Fang N, Mabb AM. Arc ubiquitination regulates endoplasmic reticulum-mediated Ca 2+ release and CaMKII signaling. Front Cell Neurosci 2023; 17:1091324. [PMID: 36998269 PMCID: PMC10043188 DOI: 10.3389/fncel.2023.1091324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 02/22/2023] [Indexed: 03/17/2023] Open
Abstract
Synaptic plasticity relies on rapid, yet spatially precise signaling to alter synaptic strength. Arc is a brain enriched protein that is rapidly expressed during learning-related behaviors and is essential for regulating metabotropic glutamate receptor-mediated long-term depression (mGluR-LTD). We previously showed that disrupting the ubiquitination capacity of Arc enhances mGluR-LTD; however, the consequences of Arc ubiquitination on other mGluR-mediated signaling events is poorly characterized. Here we find that pharmacological activation of Group I mGluRs with S-3,5-dihydroxyphenylglycine (DHPG) increases Ca2+ release from the endoplasmic reticulum (ER). Disrupting Arc ubiquitination on key amino acid residues enhances DHPG-induced ER-mediated Ca2+ release. These alterations were observed in all neuronal subregions except secondary branchpoints. Deficits in Arc ubiquitination altered Arc self-assembly and enhanced its interaction with calcium/calmodulin-dependent protein kinase IIb (CaMKIIb) and constitutively active forms of CaMKII in HEK293 cells. Colocalization of Arc and CaMKII was altered in cultured hippocampal neurons, with the notable exception of secondary branchpoints. Finally, disruptions in Arc ubiquitination were found to increase Arc interaction with the integral ER protein Calnexin. These results suggest a previously unknown role for Arc ubiquitination in the fine tuning of ER-mediated Ca2+ signaling that may support mGluR-LTD, which in turn, may regulate CaMKII and its interactions with Arc.
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Affiliation(s)
- Mohammad A. Ghane
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, United States
| | - Wei Wei
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, United States
| | - Dina W. Yakout
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, United States
| | - Zachary D. Allen
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, United States
| | - Cassandra L. Miller
- Department of Chemistry, Georgia State University, Atlanta, GA, United States
| | - Bin Dong
- Department of Chemistry, Georgia State University, Atlanta, GA, United States
| | - Jenny J. Yang
- Department of Chemistry, Georgia State University, Atlanta, GA, United States
- Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, United States
| | - Ning Fang
- Department of Chemistry, Georgia State University, Atlanta, GA, United States
| | - Angela M. Mabb
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, United States
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8
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Valdivia G, Ardiles AO, Idowu A, Salazar C, Lee HK, Gallagher M, Palacios AG, Kirkwood A. mGluR-dependent plasticity in rodent models of Alzheimer's disease. Front Synaptic Neurosci 2023; 15:1123294. [PMID: 36937569 PMCID: PMC10017879 DOI: 10.3389/fnsyn.2023.1123294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Long-term potentiation (LTP) and depression (LTD) are currently the most comprehensive models of synaptic plasticity models to subserve learning and memory. In the CA1 region of the hippocampus LTP and LTD can be induced by the activation of either NMDA receptors or mGluR5 metabotropic glutamate receptors. Alterations in either form of synaptic plasticity, NMDAR-dependent or mGluR-dependent, are attractive candidates to contribute to learning deficits in conditions like Alzheimer's disease (AD) and aging. Research, however, has focused predominantly on NMDAR-dependent forms of LTP and LTD. Here we studied age-associated changes in mGluR-dependent LTP and LTD in the APP/PS1 mouse model of AD and in Octodon degu, a rodent model of aging that exhibits features of AD. At 2 months of age, APP/PS1 mouse exhibited robust mGluR-dependent LTP and LTD that was completely lost by the 8th month of age. The expression of mGluR protein in the hippocampus of APP/PS1 mice was not affected, consistent with previous findings indicating the uncoupling of the plasticity cascade from mGluR5 activation. In O. degu, the average mGluR-LTD magnitude is reduced by half by the 3 rd year of age. In aged O. degu individuals, the reduced mGluR-LTD correlated with reduced performance in a radial arm maze task. Altogether these findings support the idea that the preservation of mGluR-dependent synaptic plasticity is essential for the preservation of learning capacity during aging.
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Affiliation(s)
- Gonzalo Valdivia
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, Baltimore, MD, United States
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Alvaro O. Ardiles
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Abimbola Idowu
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, Baltimore, MD, United States
| | - Claudia Salazar
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Hey-Kyoung Lee
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, Baltimore, MD, United States
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, United States
| | - Adrian G. Palacios
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Alfredo Kirkwood
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, Baltimore, MD, United States
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9
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Zha C, Sossin WS. The molecular diversity of plasticity mechanisms underlying memory: An evolutionary perspective. J Neurochem 2022; 163:444-460. [PMID: 36326567 DOI: 10.1111/jnc.15717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/29/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022]
Abstract
Experience triggers molecular cascades in organisms (learning) that lead to alterations (memory) to allow the organism to change its behavior based on experience. Understanding the molecular mechanisms underlying memory, particularly in the nervous system of animals, has been an exciting scientific challenge for neuroscience. We review what is known about forms of neuronal plasticity that underlie memory highlighting important issues in the field: (1) the importance of being able to measure how neurons are activated during learning to identify the form of plasticity that underlies memory, (2) the many distinct forms of plasticity important for memories that naturally decay both within and between organisms, and (3) unifying principles underlying the formation and maintenance of long-term memories. Overall, the diversity of molecular mechanisms underlying memories that naturally decay contrasts with more unified molecular mechanisms implicated in long-lasting changes. Despite many advances, important questions remain as to which mechanisms of neuronal plasticity underlie memory.
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Affiliation(s)
- Congyao Zha
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Wayne S Sossin
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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10
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Matrisciano F, Locci V, Dong E, Nicoletti F, Guidotti A, Grayson DR. Altered Expression and In Vivo Activity of mGlu5 Variant a Receptors in the Striatum of BTBR Mice: Novel Insights Into the Pathophysiology of Adult Idiopathic Forms of Autism Spectrum Disorders. Curr Neuropharmacol 2022; 20:2354-2368. [PMID: 35139800 PMCID: PMC9890299 DOI: 10.2174/1567202619999220209112609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/27/2022] [Accepted: 01/31/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND mGlu5 metabotropic glutamate receptors are considered as candidate drug targets in the treatment of "monogenic" forms of autism spectrum disorders (ASD), such as Fragile- X syndrome (FXS). However, despite promising preclinical data, clinical trials using mGlu5 receptor antagonists to treat FXS showed no beneficial effects. OBJECTIVE Here, we studied the expression and function of mGlu5 receptors in the striatum of adult BTBR mice, which model idiopathic forms of ASD, and behavioral phenotype. METHODS Behavioral tests were associated with biochemistry analysis including qPCR and western blot for mRNA and protein expression. In vivo analysis of polyphosphoinositides hydrolysis was performed to study the mGlu5-mediated intracellular signaling in the striatum of adult BTBR mice under basal conditions and after MTEP exposure. RESULTS Expression of mGlu5 receptors and mGlu5 receptor-mediated polyphosphoinositides hydrolysis were considerably high in the striatum of BTBR mice, sensitive to MTEP treatment. Changes in the expression of genes encoding for proteins involved in excitatory and inhibitory neurotransmission and synaptic plasticity, including Fmr1, Dlg4, Shank3, Brd4, bdnf-exon IX, Mef2c, and Arc, GriA2, Glun1, Nr2A, and Grm1, Grm2, GriA1, and Gad1 were also found. Behaviorally, BTBR mice showed high repetitive stereotypical behaviors, including self-grooming and deficits in social interactions. Acute or repeated injections with MTEP reversed the stereotyped behavior and the social interaction deficit. Similar effects were observed with the NMDA receptor blockers MK-801 or ketamine. CONCLUSION These findings support a pivotal role of mGlu5 receptor abnormal expression and function in idiopathic ASD adult forms and unveil novel potential targets for therapy.
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Affiliation(s)
- Francesco Matrisciano
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Valentina Locci
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Erbo Dong
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA
- Center for Alcohol Research in Epigenetics Department of Psychiatry College of Medicine University of Illinois Chicago, Chicago, IL 60612, USA
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| | - Alessandro Guidotti
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA
- Center for Alcohol Research in Epigenetics Department of Psychiatry College of Medicine University of Illinois Chicago, Chicago, IL 60612, USA
| | - Dennis R. Grayson
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA
- Center for Alcohol Research in Epigenetics Department of Psychiatry College of Medicine University of Illinois Chicago, Chicago, IL 60612, USA
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11
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Ojeda-Juárez D, Lawrence JA, Soldau K, Pizzo DP, Wheeler E, Aguilar-Calvo P, Khuu H, Chen J, Malik A, Funk G, Nam P, Sanchez H, Geschwind MD, Wu C, Yeo GW, Chen X, Patrick GN, Sigurdson CJ. Prions induce an early Arc response and a subsequent reduction in mGluR5 in the hippocampus. Neurobiol Dis 2022; 172:105834. [PMID: 35905927 PMCID: PMC10080886 DOI: 10.1016/j.nbd.2022.105834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 12/01/2022] Open
Abstract
Synapse dysfunction and loss are central features of neurodegenerative diseases, caused in part by the accumulation of protein oligomers. Amyloid-β, tau, prion, and α-synuclein oligomers bind to the cellular prion protein (PrPC), resulting in the activation of macromolecular complexes and signaling at the post-synapse, yet the early signaling events are unclear. Here we sought to determine the early transcript and protein alterations in the hippocampus during the pre-clinical stages of prion disease. We used a transcriptomic approach focused on the early-stage, prion-infected hippocampus of male wild-type mice, and identify immediate early genes, including the synaptic activity response gene, Arc/Arg3.1, as significantly upregulated. In a longitudinal study of male, prion-infected mice, Arc/Arg-3.1 protein was increased early (40% of the incubation period), and by mid-disease (pre-clinical), phosphorylated AMPA receptors (pGluA1-S845) were increased and metabotropic glutamate receptors (mGluR5 dimers) were markedly reduced in the hippocampus. Notably, sporadic Creutzfeldt-Jakob disease (sCJD) post-mortem cortical samples also showed low levels of mGluR5 dimers. Together, these findings suggest that prions trigger an early Arc response, followed by an increase in phosphorylated GluA1 and a reduction in mGluR5 receptors.
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Affiliation(s)
- Daniel Ojeda-Juárez
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Jessica A Lawrence
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Katrin Soldau
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Donald P Pizzo
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Emily Wheeler
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | | | - Helen Khuu
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Joy Chen
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Adela Malik
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Gail Funk
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Percival Nam
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Henry Sanchez
- Department of Pathology, Division of Neuropathology, University of California San Francisco, San Francisco, CA, USA
| | - Michael D Geschwind
- Department of Neurology, Weill Institute for Neurosciences, Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Chengbiao Wu
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Xu Chen
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Gentry N Patrick
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, CA, USA
| | - Christina J Sigurdson
- Department of Pathology, University of California San Diego, La Jolla, CA, USA; Department of Medicine, University of California San Diego, La Jolla, CA, USA; Department of Pathology, Microbiology and Immunology, University of California Davis, Davis, CA, USA.
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12
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Hsieh MY, Tuan LH, Chang HC, Wang YC, Chen CH, Shy HT, Lee LJ, Gau SSF. Altered synaptic protein expression, aberrant spine morphology, and impaired spatial memory in Dlgap2 mutant mice, a genetic model of autism spectrum disorder. Cereb Cortex 2022; 33:4779-4793. [PMID: 36169576 DOI: 10.1093/cercor/bhac379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 11/14/2022] Open
Abstract
A microdeletion of approximately 2.4 Mb at the 8p23 terminal region has been identified in a Taiwanese autistic boy. Among the products transcribed/translated from genes mapped in this region, the reduction of DLGAP2, a postsynaptic scaffold protein, might be involved in the pathogenesis of autism spectrum disorder (ASD). DLGAP2 protein was detected in the hippocampus yet abolished in homozygous Dlgap2 knockout (Dlgap2 KO) mice. In this study, we characterized the hippocampal phenotypes in Dlgap2 mutant mice. Dlgap2 KO mice exhibited impaired spatial memory, indicating poor hippocampal function in the absence of DLGAP2. Aberrant expressions of postsynaptic proteins, including PSD95, SHANK3, HOMER1, GluN2A, GluR2, mGluR1, mGluR5, βCAMKII, ERK1/2, ARC, BDNF, were noticed in Dlgap2 mutant mice. Further, the spine density was increased in Dlgap2 KO mice, while the ratio of mushroom-type spines was decreased. We also observed a thinner postsynaptic density thickness in Dlgap2 KO mice at the ultrastructural level. These structural changes found in the hippocampus of Dlgap2 KO mice might be linked to impaired hippocampus-related cognitive functions such as spatial memory. Mice with Dlgap2 deficiency, showing signs of intellectual disability, a common co-occurring condition in patients with ASD, could be a promising animal model which may advance our understanding of ASD.
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Affiliation(s)
- Ming-Yen Hsieh
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Li-Heng Tuan
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan.,School of Medicine, National Tsing Hua University, Hsinchu, Taiwan.,Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, Taiwan.,Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Ho-Ching Chang
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yu-Chun Wang
- Department of Otolaryngology, Head and Neck Surgery, Chi-Mei Medical Center, Tainan, Taiwan
| | - Chia-Hsiang Chen
- Department of Psychiatry, Chang Gung Memorial Hospital-Linkou, Taoyuan, Taiwan
| | - Horng-Tzer Shy
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Li-Jen Lee
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan.,Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Susan Shur-Fen Gau
- Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.,Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan
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13
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Estévez-Silva HM, Cuesto G, Romero N, Brito-Armas JM, Acevedo-Arozena A, Acebes Á, Marcellino DJ. Pridopidine Promotes Synaptogenesis and Reduces Spatial Memory Deficits in the Alzheimer's Disease APP/PS1 Mouse Model. Neurotherapeutics 2022; 19:1566-1587. [PMID: 35917088 PMCID: PMC9606189 DOI: 10.1007/s13311-022-01280-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2022] [Indexed: 10/16/2022] Open
Abstract
Sigma-1 receptor agonists have recently gained a great deal of interest due to their anti-amnesic, neuroprotective, and neurorestorative properties. Compounds such as PRE-084 or pridopidine (ACR16) are being studied as a potential treatment against cognitive decline associated with neurodegenerative disease, also to include Alzheimer's disease. Here, we performed in vitro experiments using primary neuronal cell cultures from rats to evaluate the abilities of ACR16 and PRE-084 to induce new synapses and spines formation, analyzing the expression of the possible genes and proteins involved. We additionally examined their neuroprotective properties against neuronal death mediated by oxidative stress and excitotoxicity. Both ACR16 and PRE-084 exhibited a concentration-dependent neuroprotective effect against NMDA- and H2O2-related toxicity, in addition to promoting the formation of new synapses and dendritic spines. However, only ACR16 generated dendritic spines involved in new synapse establishment, maintaining a more expanded activation of MAPK/ERK and PI3K/Akt signaling cascades. Consequently, ACR16 was also evaluated in vivo, and a dose of 1.5 mg/kg/day was administered intraperitoneally in APP/PS1 mice before performing the Morris water maze. ACR16 diminished the spatial learning and memory deficits observed in APP/PS1 transgenic mice via PI3K/Akt pathway activation. These data point to ACR16 as a pharmacological tool to prevent synapse loss and memory deficits associated with Alzheimer's disease, due to its neuroprotective properties against oxidative stress and excitotoxicity, as well as the promotion of new synapses and spines through a mechanism that involves AKT and ERK signaling pathways.
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Affiliation(s)
- Héctor M Estévez-Silva
- Departamento de Ciencias Médicas Básicas, Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Germán Cuesto
- Departamento de Ciencias Médicas Básicas, Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Ninovska Romero
- Departamento de Ciencias Médicas Básicas, Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - José Miguel Brito-Armas
- Unidad de Investigación, Hospital Universitario de Canarias, ITB-ULL/CIBERNED, Tenerife, Spain
| | - Abraham Acevedo-Arozena
- Unidad de Investigación, Hospital Universitario de Canarias, ITB-ULL/CIBERNED, Tenerife, Spain
| | - Ángel Acebes
- Departamento de Ciencias Médicas Básicas, Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain.
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14
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Early postnatal serotonin modulation prevents adult-stage deficits in Arid1b-deficient mice through synaptic transcriptional reprogramming. Nat Commun 2022; 13:5051. [PMID: 36030255 PMCID: PMC9420115 DOI: 10.1038/s41467-022-32748-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 08/12/2022] [Indexed: 11/19/2022] Open
Abstract
Autism spectrum disorder is characterized by early postnatal symptoms, although little is known about the mechanistic deviations that produce them and whether correcting them has long-lasting preventive effects on adult-stage deficits. ARID1B, a chromatin remodeler implicated in neurodevelopmental disorders, including autism spectrum disorder, exhibits strong embryonic- and early postnatal-stage expression. We report here that Arid1b-happloinsufficient (Arid1b+/–) mice display autistic-like behaviors at juvenile and adult stages accompanied by persistent decreases in excitatory synaptic density and transmission. Chronic treatment of Arid1b+/– mice with fluoxetine, a selective serotonin-reuptake inhibitor, during the first three postnatal weeks prevents synaptic and behavioral deficits in adults. Mechanistically, these rescues accompany transcriptomic changes, including upregulation of FMRP targets and normalization of HDAC4/MEF2A-related transcriptional regulation of the synaptic proteins, SynGAP1 and Arc. These results suggest that chronic modulation of serotonergic receptors during critical early postnatal periods prevents synaptic and behavioral deficits in adult Arid1b+/– mice through transcriptional reprogramming. ARID1B is a chromatin remodeler associated with autism spectrum disorders. Here the authors demonstrate that early postnatal serotonin modulation prevents adult stage deficits in Arid1b-deficient mice through synaptic transcriptional reprogramming.
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15
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Leung HW, Foo G, VanDongen A. Arc Regulates Transcription of Genes for Plasticity, Excitability and Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10081946. [PMID: 36009494 PMCID: PMC9405677 DOI: 10.3390/biomedicines10081946] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 02/06/2023] Open
Abstract
The immediate early gene Arc is a master regulator of synaptic function and a critical determinant of memory consolidation. Here, we show that Arc interacts with dynamic chromatin and closely associates with histone markers for active enhancers and transcription in cultured rat hippocampal neurons. Both these histone modifications, H3K27Ac and H3K9Ac, have recently been shown to be upregulated in late-onset Alzheimer’s disease (AD). When Arc induction by pharmacological network activation was prevented using a short hairpin RNA, the expression profile was altered for over 1900 genes, which included genes associated with synaptic function, neuronal plasticity, intrinsic excitability, and signalling pathways. Interestingly, about 100 Arc-dependent genes are associated with the pathophysiology of AD. When endogenous Arc expression was induced in HEK293T cells, the transcription of many neuronal genes was increased, suggesting that Arc can control expression in the absence of activated signalling pathways. Taken together, these data establish Arc as a master regulator of neuronal activity-dependent gene expression and suggest that it plays a significant role in the pathophysiology of AD.
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Affiliation(s)
| | - Gabriel Foo
- Duke-NUS Medical School, Singapore 169857, Singapore
| | - Antonius VanDongen
- Duke-NUS Medical School, Singapore 169857, Singapore
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA
- Correspondence:
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16
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Khan S. Endoplasmic Reticulum in Metaplasticity: From Information Processing to Synaptic Proteostasis. Mol Neurobiol 2022; 59:5630-5655. [PMID: 35739409 DOI: 10.1007/s12035-022-02916-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 06/05/2022] [Indexed: 11/29/2022]
Abstract
The ER (endoplasmic reticulum) is a Ca2+ reservoir and the unique protein-synthesizing machinery which is distributed throughout the neuron and composed of multiple different structural domains. One such domain is called EMC (endoplasmic reticulum membrane protein complex), pleiotropic nature in cellular functions. The ER/EMC position inside the neurons unmasks its contribution to synaptic plasticity via regulating various cellular processes from protein synthesis to Ca2+ signaling. Since presynaptic Ca2+ channels and postsynaptic ionotropic receptors are organized into the nanodomains, thus ER can be a crucial player in establishing TMNCs (transsynaptic molecular nanocolumns) to shape efficient neural communications. This review hypothesized that ER is not only involved in stress-mediated neurodegeneration but also axon regrowth, remyelination, neurotransmitter switching, information processing, and regulation of pre- and post-synaptic functions. Thus ER might not only be a protein-synthesizing and quality control machinery but also orchestrates plasticity of plasticity (metaplasticity) within the neuron to execute higher-order brain functions and neural repair.
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Affiliation(s)
- Shumsuzzaman Khan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA.
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17
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Chen Z, Ding Y, Zeng Y, Zhang XP, Chen JY. Dexmedetomidine reduces propofol-induced hippocampal neuron injury by modulating the miR-377-5p/Arc pathway. BMC Pharmacol Toxicol 2022; 23:18. [PMID: 35337381 PMCID: PMC8957152 DOI: 10.1186/s40360-022-00555-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/08/2022] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Propofol and dexmedetomidine (DEX) are widely used in general anesthesia, and exert toxic and protective effects on hippocampal neurons, respectively. The study sought to investigate the molecular mechanisms of DEX-mediated neuroprotection against propofol-induced hippocampal neuron injury in mouse brains. METHODS Hippocampal neurons of mice and HT22 cells were treated with propofol, DEX, and propofol+DEX. In addition, transfection of miR-377-5p mimics or inhibitors was performed in HT22 cells. Neuronal apoptosis was evaluated by a means of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) or Hochest 33,258 staining; Arc positive expression in hippocampus tissues was detected using a microscope in immunohistochemistry assays; miRNA-377-5p expression was quantified by RT-qPCR; the protein levels of Arc, DNMT3A, and DNMT3B were determined using western blot; Cell Counting Kit-8 (CCK-8) assay was used to detect the viability and apoptotic rate of the neurons; methylation analysis in the miR-377-5p promoter was performed through methylated DNA immunoprecipitation (MeDIP) assay; dual luciferase reporter assay was performed to confirm whether Arc was under targeted regulation of miR-377-5p. RESULTS In the current study, both in vitro and in vivo, propofol treatment induced hippocampal neuron apoptosis and suppressed cell viability. DNMT3A and DNMT3B expression levels were decreased following propofol treatment, resulting in lowered methylation in the miR-377-5p promoter region and then enhanced expression of miR-377-5p, leading to a decrease in the expression of downstream Arc. Conversely, the expression levels of DNMT3A and DNMT3B were increased following DEX treatment, thus methylation in miR-377-5p promoter region was improved, and miR-377-5p expression was decreased, leading to an increase in the expression of downstream Arc. Eventually, DEX pretreatment protected hippocampal neurons against propofol-induced neurotoxicity by recovering the expression levels of DNMT3A, miR-377-5p, and Arc to the normal levels. Additionally, DNMT3A knockdown improved miR-377-5p expression but reduced Arc expression, and DNMT3A overexpression exerted the opposite effects. Dual luciferase reporter assay revealed a binding target between miR-377-5p and Arc 3'UTR. The neuroprotective effect of DEX against propofol-induced neuronal apoptosis was diminished after Arc knockdown. Silencing Arc independently triggered the apoptosis of HT22 cells, which was alleviated through transfection of miR-377-5p inhibitors. CONCLUSIONS DEX reduced propofol-induced hippocampal neuron injury via the miR-377-5p/Arc signaling pathway.
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Affiliation(s)
- Zong Chen
- Department of Anesthesiology, The First Affiliated Hospital of Guangdong Pharmaceutical University, NO.19 Nonglin Road, Yuexiu District, Guangzhou, Guangdong Province, China
| | - Yong Ding
- Department of Anesthesiology, The First Affiliated Hospital of Guangdong Pharmaceutical University, NO.19 Nonglin Road, Yuexiu District, Guangzhou, Guangdong Province, China
| | - Ying Zeng
- Department of Anesthesiology, Shenzhen Shajin Hospital Affiliated to Guangzhou Medical University, Shenzhen, China
| | - Xue-Ping Zhang
- Department of Anesthesiology, Shenzhen People's Hospital, Shenzhen Anesthesiology Engineering Center, The Second Clinical Medical College of Jinan University, NO. 1017 Dongmen North Road, Luohu District, Shenzhen, Guangdong Province, China.
| | - Jian-Yan Chen
- Department of Anesthesiology, The First Affiliated Hospital of Guangdong Pharmaceutical University, NO.19 Nonglin Road, Yuexiu District, Guangzhou, Guangdong Province, China.
- Department of Anesthesiology, Shenzhen Shajin Hospital Affiliated to Guangzhou Medical University, Shenzhen, China.
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18
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Edonerpic maleate regulates glutamate receptors through CRMP2- and Arc-mediated mechanisms in response to brain trauma. Cell Death Dis 2022; 8:95. [PMID: 35246523 PMCID: PMC8897457 DOI: 10.1038/s41420-022-00901-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 11/09/2022]
Abstract
Dysfunction of ionotropic glutamate receptors (iGluRs) is a key molecular mechanism of excitotoxic neuronal injury following traumatic brain injury (TBI). Edonerpic maleate is a low molecular-weight compound that was screened as a candidate neuroprotective agent. In this study, we investigated its effects on TBI and GluRs signaling. Traumatic neuronal injury (TNI) induced by scratch followed by glutamate treatment was performed to mimic TBI in vitro. Edonerpic maleate at 1 and 10 μM exerted protective activity when it was added within 2 h following injury. The protective activities were also confirmed by the reduction of lipid peroxidation and oxidative stress. In addition, edonerpic maleate inhibited the expression of surface NR2B, total GluR1, and surface GluR1, and mitigated the intracellular Ca2+ responses following injury in vitro. Western blot analysis showed that edonerpic maleate reduced the cleavage of collapsing response mediator protein 2 (CRMP2), but increased the expression of postsynaptic protein Arc. By using gene overexpression and silencing technologies, CRMP2 was overexpressed and Arc was knockdown in cortical neurons. The results showed that the effect of edonerpic maleate on NMDA receptor expression was mediated by CRMP2, whereas the edonerpic maleate-induced AMPA receptor regulation was dependent on Arc activation. In in vivo TBI model, 30 mg/kg edonerpic maleate alleviated the TBI-induced brain edema, neuronal loss, and microglial activation, with no effect on locomotor function at 24 h. However, edonerpic maleate improves long-term neurological function after TBI. Furthermore, edonerpic maleate inhibited CRMP2 cleavage but increased Arc activation in vivo. In summary, our results identify edonerpic maleate as a clinically potent small compound with which to attenuate TBI-related brain damage through regulating GluRs signaling.
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19
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Brökling J, Brunne B, Rune GM. Sex-dependent responsiveness of hippocampal neurons to sex neurosteroids: A role of Arc/Arg3.1. J Neuroendocrinol 2022; 34:e13090. [PMID: 35081672 DOI: 10.1111/jne.13090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 12/23/2021] [Accepted: 01/07/2022] [Indexed: 11/28/2022]
Abstract
Sex steroids, such as estradiol (E2 ) and dihydrotestosterone (DHT), regulate hippocampal plasticity and memory in a sex-dependent manner. Because the activity-regulated cytoskeleton protein Arc/Arg3.1 is essential for long-term memory formation and synaptic plasticity, we investigated the expression of Arc/Arg3.1 with respect to its responsiveness to E2 and DHT in male and female hippocampal neurons. For the first time, we show that, in hippocampal neurons, Arc/Arg3.1 expression is sex-dependently regulated by sex steroids. No difference in the expression between sexes was observed under control conditions. Using a quantitative real-time polymerase chain reaction, western blot analysis and quantitative immunoreactivity, upregulation of Arc/Arg3.1 protein expression was observed in specifically female hippocampal neurons after application of E2 to the cultures. Conversely, upregulation of Arc/Arg3.1 was seen in specifically male neurons after application of DHT. A quantitative real-time PCR revealed that the sex-dependency was most pronounced on the mRNA level. Most importantly, the effects of E2 in cultures of female animals were abolished when neuron-derived E2 synthesis was inhibited. Our results point to a potentially important role of Arc/Arg3.1 regarding sex-dependency in sex steroid-induced synaptic plasticity in the hippocampus.
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Affiliation(s)
- Janina Brökling
- Institute of Neuroanatomy, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Bianka Brunne
- Institute of Neuroanatomy, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Gabriele M Rune
- Institute of Cell Biology and Neurobiology, Universitätsmedizin Charité Berlin, Berlin, Germany
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20
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Vitamin B 12-folic acid supplementation regulates neuronal immediate early gene expression and improves hippocampal dendritic arborization and memory in old male mice. Neurochem Int 2021; 150:105181. [PMID: 34509560 DOI: 10.1016/j.neuint.2021.105181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 01/19/2023]
Abstract
As the relationship among diet, brain aging and memory is complex, it provides ample opportunity for research in multiple directions including behaviour, epigenetics and neuroplasticity. Nutritional deficiencies together with genetic and environmental factors are the major cause of many age-associated pathologies including memory loss. A compromised vitamin B12-folate status in older people is highly prevalent worldwide. Researchers have established a close association between the adequate level of B12-folate and the maintenance of cognitive brain functions. One of the main reasons for age-associated memory loss is downregulation of neuronal immediate early genes (nIEGs). Therefore, we hypothesize here that vitamin B12-folic acid supplementation in old mice can improve memory by altering the expression status of nIEGs. To check this, 72-week-old male Swiss albino mice were orally administered with 2 μg of vitamin B12 and 22 μg of folic acid/mouse/day for eight weeks. Such supplementation improved recognition memory in old and altered the expression of nIEGs. The expression of nIEGs was further found to be regulated by changes in DNA methylation at their promoter regions and CREB phosphorylation (pCREB). In addition, Golgi-Cox staining showed significant improvement in dendritic length, number of branching points and spine density of hippocampal CA1 pyramidal neurons by B12-folic acid supplementation. Taken together, these findings suggest that vitamin B12-folic acid supplementation regulates nIEGs expression and improves dendritic arborization of hippocampal neurons and memory in old male mice.
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21
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Parent MB, Ferreira-Neto HC, Kruemmel AR, Althammer F, Patel AA, Keo S, Whitley KE, Cox DN, Stern JE. Heart failure impairs mood and memory in male rats and down-regulates the expression of numerous genes important for synaptic plasticity in related brain regions. Behav Brain Res 2021; 414:113452. [PMID: 34274373 DOI: 10.1016/j.bbr.2021.113452] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 05/21/2021] [Accepted: 07/08/2021] [Indexed: 12/01/2022]
Abstract
Chronic heart failure (HF) is a serious disorder that afflicts more than 26 million patients worldwide. HF is comorbid with depression, anxiety and memory deficits that have serious implications for quality of life and self-care in patients who have HF. Still, there are few studies that have assessed the effects of severely reduced ejection fraction (≤40 %) on cognition in non-human animal models. Moreover, limited information is available regarding the effects of HF on genetic markers of synaptic plasticity in brain areas critical for memory and mood regulation. We induced HF in male rats and tested mood and anxiety (sucrose preference and elevated plus maze) and memory (spontaneous alternation and inhibitory avoidance) and measured the simultaneous expression of 84 synaptic plasticity-associated genes in dorsal (DH) and ventral hippocampus (VH), basolateral (BLA) and central amygdala (CeA) and prefrontal cortex (PFC). We also included the hypothalamic paraventricular nucleus (PVN), which is implicated in neurohumoral activation in HF. Our results show that rats with severely reduced ejection fraction recapitulate behavioral symptoms seen in patients with chronic HF including, increased anxiety and impaired memory in both tasks. HF also downregulated several synaptic-plasticity genes in PFC and PVN, moderate decreases in DH and CeA and minimal effects in BLA and VH. Collectively, these findings identify candidate brain areas and molecular mechanisms underlying HF-induced disturbances in mood and memory.
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Affiliation(s)
- Marise B Parent
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | | | | | | | - Atit A Patel
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Sreinick Keo
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | | | - Daniel N Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Javier E Stern
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA.
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22
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Upreti C, Woodruff CM, Zhang XL, Yim MJ, Zhou ZY, Pagano AM, Rehanian DS, Yin D, Kandel ER, Stanton PK, Nicholls RE. Loss of retinoid X receptor gamma subunit impairs group 1 mGluR mediated electrophysiological responses and group 1 mGluR dependent behaviors. Sci Rep 2021; 11:5552. [PMID: 33692389 PMCID: PMC7946894 DOI: 10.1038/s41598-021-84943-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/17/2021] [Indexed: 11/09/2022] Open
Abstract
Retinoid X receptors are members of the nuclear receptor family that regulate gene expression in response to retinoic acid and related ligands. Group 1 metabotropic glutamate receptors are G-protein coupled transmembrane receptors that activate intracellular signaling cascades in response to the neurotransmitter, glutamate. These two classes of molecules have been studied independently and found to play important roles in regulating neuronal physiology with potential clinical implications for disorders such as depression, schizophrenia, Parkinson's and Alzheimer's disease. Here we show that mice lacking the retinoid X receptor subunit, RXRγ, exhibit impairments in group 1 mGluR-mediated electrophysiological responses at hippocampal Schaffer collateral-CA1 pyramidal cell synapses, including impaired group 1 mGluR-dependent long-term synaptic depression (LTD), reduced group 1 mGluR-induced calcium release, and loss of group 1 mGluR-activated voltage-sensitive currents. These animals also exhibit impairments in a subset of group 1 mGluR-dependent behaviors, including motor performance, spatial object recognition, and prepulse inhibition. Together, these observations demonstrate convergence between the RXRγ and group 1 mGluR signaling pathways that may function to coordinate their regulation of neuronal activity. They also identify RXRγ as a potential target for the treatment of disorders in which group 1 mGluR signaling has been implicated.
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Affiliation(s)
- Chirag Upreti
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
| | - Caitlin M Woodruff
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Xiao-Lei Zhang
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
| | - Michael J Yim
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Zhen-Yu Zhou
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA.,Department of Neurology, New York Medical College, Valhalla, NY, 10595, USA
| | - Andrew M Pagano
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Dina S Rehanian
- Department of Pathology and Cell Biology, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA.,Taub Institute for Research on Alzheimer's Disease and Aging Brain, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA
| | - Deqi Yin
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Howard Hughes Medical Institute, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Eric R Kandel
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Howard Hughes Medical Institute, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Kavli Institute for Brain Science, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Patric K Stanton
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA.,Department of Neurology, New York Medical College, Valhalla, NY, 10595, USA
| | - Russell E Nicholls
- Department of Pathology and Cell Biology, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA. .,Taub Institute for Research on Alzheimer's Disease and Aging Brain, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA.
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23
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Developmental impaired Akt signaling in the Shank1 and Shank3 double knock-out mice. Mol Psychiatry 2021; 26:1928-1944. [PMID: 33402706 PMCID: PMC8440179 DOI: 10.1038/s41380-020-00979-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/23/2020] [Accepted: 12/01/2020] [Indexed: 01/30/2023]
Abstract
Human mutations and haploinsufficiency of the SHANK family genes are associated with autism spectrum disorders (ASD) and intellectual disability (ID). Complex phenotypes have been also described in all mouse models of Shank mutations and deletions, consistent with the heterogeneity of the human phenotypes. However, the specific role of Shank proteins in synapse and neuronal functions remain to be elucidated. Here, we generated a new mouse model to investigate how simultaneously deletion of Shank1 and Shank3 affects brain development and behavior in mice. Shank1-Shank3 DKO mice showed a low survival rate, a developmental strong reduction in the activation of intracellular signaling pathways involving Akt, S6, ERK1/2, and eEF2 during development and a severe behavioral impairments. Our study suggests that Shank1 and Shank3 proteins are essential to developmentally regulate the activation of Akt and correlated intracellular pathways crucial for mammalian postnatal brain development and synaptic plasticity. Therefore, Akt function might represent a new therapeutic target for enhancing cognitive abilities of syndromic ASD patients.
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24
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Yakout DW, Shree N, Mabb AM. Effect of pharmacological manipulations on Arc function. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2020; 2:100013. [PMID: 34909648 PMCID: PMC8663979 DOI: 10.1016/j.crphar.2020.100013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022] Open
Abstract
Activity-regulated cytoskeleton-associated protein (Arc) is a brain-enriched immediate early gene that regulates important mechanisms implicated in learning and memory. Arc levels are controlled through a balance of induction and degradation in an activity-dependent manner. Arc further undergoes multiple post-translational modifications that regulate its stability, localization and function. Recent studies demonstrate that these features of Arc can be pharmacologically manipulated. In this review, we discuss some of these compounds, with an emphasis on drugs of abuse and psychotropic drugs. We also discuss inflammatory states that regulate Arc.
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Affiliation(s)
- Dina W. Yakout
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Nitheyaa Shree
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Angela M. Mabb
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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25
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Zhang H, Bramham CR. Arc/Arg3.1 function in long-term synaptic plasticity: Emerging mechanisms and unresolved issues. Eur J Neurosci 2020; 54:6696-6712. [PMID: 32888346 DOI: 10.1111/ejn.14958] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/18/2020] [Accepted: 08/14/2020] [Indexed: 02/06/2023]
Abstract
Arc (activity-regulated cytoskeleton-associated protein) is posited as a critical regulator of long-term synaptic plasticity at excitatory synapses, including long-term potentiation, long-term depression, inverse synaptic tagging and homoeostatic scaling, with pivotal roles in memory and postnatal cortical development. However, the mechanisms underlying the bidirectional regulation of synaptic strength are poorly understood. Here we review evidence from different plasticity paradigms, highlight outstanding issues and discuss stimulus-specific mechanisms that dictate Arc function. We propose a model in which Arc bidirectionally controls synaptic strength by coordinate regulation of AMPA-type glutamate receptor (AMPAR) trafficking and actin cytoskeletal dynamics in dendritic spines. Key to this model, Arc is proposed to function as an activity-dependent regulator of AMPAR lateral membrane diffusion and trapping at synapses.
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Affiliation(s)
- Hongyu Zhang
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Clive R Bramham
- Department of Biomedicine, University of Bergen, Bergen, Norway
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26
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Blanchette CR, Rodal AA. Mechanisms for biogenesis and release of neuronal extracellular vesicles. Curr Opin Neurobiol 2020; 63:104-110. [PMID: 32387925 PMCID: PMC7483335 DOI: 10.1016/j.conb.2020.03.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/24/2020] [Accepted: 03/24/2020] [Indexed: 02/01/2023]
Abstract
Neurons release membrane-bound extracellular vesicles (EVs) carrying proteins, nucleic acids, and other cargoes to mediate neuronal development, plasticity, inflammation, regeneration, and degeneration. Functional studies and therapeutic interventions into EV-dependent processes will require a deep understanding of how neuronal EVs are formed and released. However, unraveling EV biogenesis and trafficking mechanisms is challenging, since there are multiple pathways governing generation of different types of EVs, which overlap mechanistically with each other, as well as with intracellular endolysosomal trafficking pathways. Further, neurons present special considerations for EVs due to their extreme morphologies and specialization for membrane traffic. Here, we review recent work elucidating neuronal pathways that regulate EV biogenesis and release, with the goal of identifying directed strategies for experimental and therapeutic targeting of specific types of EVs.
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27
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Albanesi JP, Barylko B, DeMartino GN, Jameson DM. Palmitoylated Proteins in Dendritic Spine Remodeling. Front Synaptic Neurosci 2020; 12:22. [PMID: 32655390 PMCID: PMC7325885 DOI: 10.3389/fnsyn.2020.00022] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Activity-responsive changes in the actin cytoskeleton are required for the biogenesis, motility, and remodeling of dendritic spines. These changes are governed by proteins that regulate the polymerization, depolymerization, bundling, and branching of actin filaments. Thus, processes that have been extensively characterized in the context of non-neuronal cell shape change and migration are also critical for learning and memory. In this review article, we highlight actin regulatory proteins that associate, at least transiently, with the dendritic plasma membrane. All of these proteins have been shown, either in directed studies or in high-throughput screens, to undergo palmitoylation, a potentially reversible, and stimulus-dependent cysteine modification. Palmitoylation increases the affinity of peripheral proteins for the membrane bilayer and contributes to their subcellular localization and recruitment to cholesterol-rich membrane microdomains.
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Affiliation(s)
- Joseph P. Albanesi
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Barbara Barylko
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - George N. DeMartino
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - David M. Jameson
- Department of Cell and Molecular Biology, University of Hawaii, Honolulu, HI, United States
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28
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Molecular Mechanisms of Non-ionotropic NMDA Receptor Signaling in Dendritic Spine Shrinkage. J Neurosci 2020; 40:3741-3750. [PMID: 32321746 DOI: 10.1523/jneurosci.0046-20.2020] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/20/2020] [Accepted: 04/05/2020] [Indexed: 12/18/2022] Open
Abstract
Structural plasticity of dendritic spines is a key component of the refinement of synaptic connections during learning. Recent studies highlight a novel role for the NMDA receptor (NMDAR), independent of ion flow, in driving spine shrinkage and LTD. Yet little is known about the molecular mechanisms that link conformational changes in the NMDAR to changes in spine size and synaptic strength. Here, using two-photon glutamate uncaging to induce plasticity at individual dendritic spines on hippocampal CA1 neurons from mice and rats of both sexes, we demonstrate that p38 MAPK is generally required downstream of non-ionotropic NMDAR signaling to drive both spine shrinkage and LTD. In a series of pharmacological and molecular genetic experiments, we identify key components of the non-ionotropic NMDAR signaling pathway driving dendritic spine shrinkage, including the interaction between NOS1AP (nitric oxide synthase 1 adaptor protein) and neuronal nitric oxide synthase (nNOS), nNOS enzymatic activity, activation of MK2 (MAPK-activated protein kinase 2) and cofilin, and signaling through CaMKII. Our results represent a large step forward in delineating the molecular mechanisms of non-ionotropic NMDAR signaling that can drive shrinkage and elimination of dendritic spines during synaptic plasticity.SIGNIFICANCE STATEMENT Signaling through the NMDA receptor (NMDAR) is vitally important for the synaptic plasticity that underlies learning. Recent studies highlight a novel role for the NMDAR, independent of ion flow, in driving synaptic weakening and dendritic spine shrinkage during synaptic plasticity. Here, we delineate several key components of the molecular pathway that links conformational signaling through the NMDAR to dendritic spine shrinkage during synaptic plasticity.
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29
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A Late Phase of Long-Term Synaptic Depression in Cerebellar Purkinje Cells Requires Activation of MEF2. Cell Rep 2020; 26:1089-1097.e3. [PMID: 30699340 PMCID: PMC6433166 DOI: 10.1016/j.celrep.2019.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 09/06/2018] [Accepted: 12/28/2018] [Indexed: 12/18/2022] Open
Abstract
The MEF2 family of transcription factors restricts excitatory synapse number in an activity-dependent fashion during development, yet MEF2 has not been implicated in long-term synaptic depression (LTD), which is thought to initiate synapse elimination. Mutations in MEF2 pathways are implicated in autism spectrum disorders, which include cerebellar dysfunction. Here, we test the hypothesis that cerebellar LTD requires postsynaptic activation of MEF2. Knockdown of MEF2D produces suppression of the transcription-dependent late phase of LTD in cultured Purkinje cells. The late phase of LTD is also completely blocked in Purkinje cells derived from MEF2A+MEF2D null mice and rescued with plasmids that drive expression of MEF2D but not phosphatase-resistant mutant MEF2D S444D. Wild-type Purkinje cells transfected with a constitutively active form of MEF2 show no alterations of synaptic strength. Thus, postsynaptic activation of MEF2 by S444 dephosphorylation is necessary, but not sufficient, for the late phase of cerebellar LTD. Neurodevelopmental disorders can reflect defects in synaptic pruning, which is thought to require activity-dependent weakening of synapses, a process called long-term depression. Andzelm et al. show that MEF2, which is important for neuronal development, is required for the late phase of long-term depression in the cerebellum.
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30
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Role of the TRPC1 Channel in Hippocampal Long-Term Depression and in Spatial Memory Extinction. Int J Mol Sci 2020; 21:ijms21051712. [PMID: 32138218 PMCID: PMC7084652 DOI: 10.3390/ijms21051712] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/21/2020] [Accepted: 02/27/2020] [Indexed: 12/19/2022] Open
Abstract
Group I metabotropic glutamate receptors (mGluR) are involved in various forms of synaptic plasticity that are believed to underlie declarative memory. We previously showed that mGluR5 specifically activates channels containing TRPC1, an isoform of the canonical family of Transient Receptor Potential channels highly expressed in the CA1-3 regions of the hippocampus. Using a tamoxifen-inducible conditional knockout model, we show here that the acute deletion of the Trpc1 gene alters the extinction of spatial reference memory. mGluR-induced long-term depression, which is partially responsible for memory extinction, was impaired in these mice. Similar results were obtained in vitro and in vivo by inhibiting the channel by its most specific inhibitor, Pico145. Among the numerous known postsynaptic pathways activated by type I mGluR, we observed that the deletion of Trpc1 impaired the activation of ERK1/2 and the subsequent expression of Arc, an immediate early gene that plays a key role in AMPA receptors endocytosis and subsequent long-term depression.
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31
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Arc silence aggravates traumatic neuronal injury via mGluR1-mediated ER stress and necroptosis. Cell Death Dis 2020; 11:4. [PMID: 31919348 PMCID: PMC6952410 DOI: 10.1038/s41419-019-2198-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 12/15/2022]
Abstract
Delayed neuronal death is associated with neurological deficits and mortality after traumatic brain injury (TBI), where post-synaptic density (PSD) proteins are thought to play key roles. The immediate-early gene (IEG) coded protein Arc is a brain-specific PSD protein that controls synaptic plasticity and learning behaviors. In this study, we investigated the expression and biological function of Arc in neuronal death after TBI in an in vitro model mimicked by traumatic neuronal injury (TNI) in cortical neurons. TNI caused a temporal increase of Arc expression at 3 and 6 h. Knockdown of Arc expression using small interfering RNA (Si-Arc-3) promoted TNI-induced cytotoxicity and apoptosis. The results of western blot showed that Si-Arc-3 transfection further enhanced the activation of endoplasmic reticulum (ER) stress-associated factors, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and caspase-12 after TNI. In addition, knockdown of Arc significantly increased expression of (receptor-interacting protein kinase 1) RIP1 and the number of necroptotic cells, which were apparently prevented by necrostatin-1 (Nec-1). The results of immunostaining and western blot showed that knockdown of Arc activated the metabotropic glutamate receptor 1 (mGluR1) and intracellular Ca2+ release in neurons. Mechanistically, the Si-Arc-3-induced activation of ER stress-associated factors, RIP1 expression, apoptosis, and necroptosis were partially reversed by the mGluR1 antagonist AIDA. In summary, our data suggest that silence of Arc expression aggravates neuronal death after TNI by promoting apoptosis and necroptosis. These data support for the first time that Arc may represent a novel candidate for therapies against TBI.
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32
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Chastain-Potts SE, Tesic V, Tat QL, Cabrera OH, Quillinan N, Jevtovic-Todorovic V. Sevoflurane Exposure Results in Sex-Specific Transgenerational Upregulation of Target IEGs in the Subiculum. Mol Neurobiol 2020; 57:11-22. [PMID: 31512116 PMCID: PMC6980510 DOI: 10.1007/s12035-019-01752-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 12/22/2022]
Abstract
Large body of animal work and emerging clinical findings have suggested that early exposure to anesthetics may result in increased risk of learning disabilities and behavioral impairments. Recent studies have begun to investigate anesthesia-induced epigenetic modifications to elucidate their role in behavioral and neurodevelopmental abnormalities. Here we examine sevoflurane-induced transgenerational modifications of subicular neuronal DNA methylation and expression of immediate early genes (IEGs), arc and junB, crucial to synaptic plasticity and normal neuronal development. We show that 6 h sevoflurane exposure in postnatal day 7 rat pups resulted in decreased neuronal 5-methycytosine, indicating reduced DNA methylation. This effect is transgenerationally expressed in offspring born to exposed mothers which is of importance considering that decreased DNA methylation in the brain has been linked with functional decline in learning and memory. We further show that sevoflurane exposure induces upregulation of Arc and JunB mRNA expression, 42.7% and 35.2%, respectively. Transgenerational changes in Arc and JunB mRNA were sexually dimorphic only occurring in males born to exposed females, expressed as upregulation of Arc and JunB mRNA, 71.6% and 74.0%, respectively. We further investigated correlation between altered arc promoter methylation and observed upregulation of Arc mRNA and observed that sevoflurane reduced methylation in the 5-upstream promoter region of females exposed to sevoflurane. Transgenerational hypomethylation and modifications to IEGs crucial to synaptic plasticity, observed following neonatal sevoflurane exposure could contribute to morphological and cognitive deficits known to occur with neonatal sevoflurane exposure.
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Affiliation(s)
- Shelby E Chastain-Potts
- Department of Anesthesiology, University of Colorado School of Medicine, 13001 E. 17th Pl., Aurora, CO, 80045, USA
| | - Vesna Tesic
- Department of Anesthesiology, University of Colorado School of Medicine, 13001 E. 17th Pl., Aurora, CO, 80045, USA
| | - Quy L Tat
- Department of Anesthesiology, University of Colorado School of Medicine, 13001 E. 17th Pl., Aurora, CO, 80045, USA
| | - Omar H Cabrera
- Department of Anesthesiology, University of Colorado School of Medicine, 13001 E. 17th Pl., Aurora, CO, 80045, USA
| | - Nidia Quillinan
- Department of Anesthesiology, University of Colorado School of Medicine, 13001 E. 17th Pl., Aurora, CO, 80045, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado School of Medicine, 13001 E. 17th Pl., Aurora, CO, 80045, USA.
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33
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Mejias R, Chiu SL, Han M, Rose R, Gil-Infante A, Zhao Y, Huganir RL, Wang T. Purkinje cell-specific Grip1/2 knockout mice show increased repetitive self-grooming and enhanced mGluR5 signaling in cerebellum. Neurobiol Dis 2019; 132:104602. [PMID: 31476380 DOI: 10.1016/j.nbd.2019.104602] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/30/2019] [Accepted: 08/30/2019] [Indexed: 01/16/2023] Open
Abstract
Cerebellar Purkinje cell (PC) loss is a consistent pathological finding in autism. However, neural mechanisms of PC-dysfunction in autism remain poorly characterized. Glutamate receptor interacting proteins 1/2 (Grip1/2) regulate AMPA receptor (AMPAR) trafficking and synaptic strength. To evaluate role of PC-AMPAR signaling in autism, we produced PC-specific Grip1/2 knockout mice by crossing Grip2 conventional and Grip1 conditional KO with L7-Cre driver mice. PCs in the mutant mice showed normal morphology and number, and a lack of Grip1/2 expression. Rodent behavioral testing identified normal ambulation, anxiety, social interaction, and an increase in repetitive self-grooming. Electrophysiology studies revealed normal mEPSCs but an impaired mGluR-LTD at the Parallel Fiber-PC synapses. Immunoblots showed increased expression of mGluR5 and Arc, and enhanced phosphorylation of P38 and AKT in cerebellum of PC-specific Grip1/2 knockout mice. Results indicate that loss of Grip1/2 in PCs contributes to increased repetitive self-grooming, a core autism behavior in mice. Results support a role of AMPAR trafficking defects in PCs and disturbances of mGluR5 signaling in cerebellum in the pathogenesis of repetitive behaviors.
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Affiliation(s)
- Rebeca Mejias
- McKusick-Nathans Department of Genetic Medicine and Department of Pediatrics, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Physiology, University of Seville, 41012 Seville, Spain.
| | - Shu-Ling Chiu
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Mei Han
- McKusick-Nathans Department of Genetic Medicine and Department of Pediatrics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Rebecca Rose
- McKusick-Nathans Department of Genetic Medicine and Department of Pediatrics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Ana Gil-Infante
- Department of Physiology, University of Seville, 41012 Seville, Spain
| | - Yifan Zhao
- McKusick-Nathans Department of Genetic Medicine and Department of Pediatrics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Richard L Huganir
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Tao Wang
- McKusick-Nathans Department of Genetic Medicine and Department of Pediatrics, Johns Hopkins University, Baltimore, MD 21205, USA.
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34
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Nielsen LD, Pedersen CP, Erlendsson S, Teilum K. The Capsid Domain of Arc Changes Its Oligomerization Propensity through Direct Interaction with the NMDA Receptor. Structure 2019; 27:1071-1081.e5. [DOI: 10.1016/j.str.2019.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/28/2019] [Accepted: 03/31/2019] [Indexed: 12/20/2022]
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35
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Penrod RD, Kumar J, Smith LN, McCalley D, Nentwig TB, Hughes BW, Barry GM, Glover K, Taniguchi M, Cowan CW. Activity-regulated cytoskeleton-associated protein (Arc/Arg3.1) regulates anxiety- and novelty-related behaviors. GENES BRAIN AND BEHAVIOR 2019; 18:e12561. [PMID: 30761730 DOI: 10.1111/gbb.12561] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 01/19/2019] [Accepted: 02/12/2019] [Indexed: 02/06/2023]
Abstract
The activity-regulated cytoskeleton-associated protein (Arc, also known as Arg3.1) regulates glutamatergic synapse plasticity and has been linked to neuropsychiatric illness; however, its role in behaviors associated with mood and anxiety disorders remains unclear. We find that stress upregulates Arc expression in the adult mouse nucleus accumbens (NAc)-a brain region implicated in mood and anxiety behaviors. Global Arc knockout mice have altered AMPAR-subunit surface levels in the adult NAc, and the Arc-deficient mice show reductions in anxiety-like behavior, deficits in social novelty preference, and antidepressive-like behavior. Viral-mediated expression of Arc in the adult NAc of male, global Arc KO mice restores normal levels of anxiety-like behavior in the elevated plus maze (EPM). Consistent with this finding, viral-mediated reduction of Arc in the adult NAc reduces anxiety-like behavior in male, but not female, mice in the EPM. NAc-specific reduction of Arc also produced significant deficits in both object and social novelty preference tasks. Together our findings indicate that Arc is essential for regulating normal mood- and anxiety-related behaviors and novelty discrimination, and that Arc's function within the adult NAc contributes to these behavioral effects.
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Affiliation(s)
- Rachel D Penrod
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts
| | - Jaswinder Kumar
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts.,Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Laura N Smith
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts.,Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Daniel McCalley
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Todd B Nentwig
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Brandon W Hughes
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Gabriella M Barry
- Department of Science and Mathematics, Honors College, College of Charleston, Charleston, South Carolina
| | - Kelsey Glover
- Department of Science and Mathematics, Honors College, College of Charleston, Charleston, South Carolina
| | - Makoto Taniguchi
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts.,Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Christopher W Cowan
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina.,Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts.,Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas
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36
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Seibt J, Frank MG. Primed to Sleep: The Dynamics of Synaptic Plasticity Across Brain States. Front Syst Neurosci 2019; 13:2. [PMID: 30774586 PMCID: PMC6367653 DOI: 10.3389/fnsys.2019.00002] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/09/2019] [Indexed: 11/13/2022] Open
Abstract
It is commonly accepted that brain plasticity occurs in wakefulness and sleep. However, how these different brain states work in concert to create long-lasting changes in brain circuitry is unclear. Considering that wakefulness and sleep are profoundly different brain states on multiple levels (e.g., cellular, molecular and network activation), it is unlikely that they operate exactly the same way. Rather it is probable that they engage different, but coordinated, mechanisms. In this article we discuss how plasticity may be divided across the sleep-wake cycle, and how synaptic changes in each brain state are linked. Our working model proposes that waking experience triggers short-lived synaptic events that are necessary for transient plastic changes and mark (i.e., 'prime') circuits and synapses for further processing in sleep. During sleep, synaptic protein synthesis at primed synapses leads to structural changes necessary for long-term information storage.
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Affiliation(s)
- Julie Seibt
- Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom
| | - Marcos G. Frank
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University Spokane, Spokane, WA, United States
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37
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Manohar S, Ramchander PV, Salvi R, Seigel GM. Synaptic Reorganization Response in the Cochlear Nucleus Following Intense Noise Exposure. Neuroscience 2018; 399:184-198. [PMID: 30593923 DOI: 10.1016/j.neuroscience.2018.12.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 12/13/2022]
Abstract
The cochlear nucleus, located in the brainstem, receives its afferent auditory input exclusively from the auditory nerve fibers of the ipsilateral cochlea. Noise-induced neurodegenerative changes occurring in the auditory nerve stimulate a cascade of neuroplastic changes in the cochlear nucleus resulting in major changes in synaptic structure and function. To identify some of the key molecular mechanisms mediating this synaptic reorganization, we unilaterally exposed rats to a high-intensity noise that caused significant hearing loss and then measured the resulting changes in a synaptic plasticity gene array targeting neurogenesis and synaptic reorganization. We compared the gene expression patterns in the dorsal cochlear nucleus (DCN) and ventral cochlear nucleus (VCN) on the noise-exposed side versus the unexposed side using a PCR gene array at 2 d (early) and 28 d (late) post-exposure. We discovered a number of differentially expressed genes, particularly those related to synaptogenesis and regeneration. Significant gene expression changes occurred more frequently in the VCN than the DCN and more changes were seen at 28 d versus 2 d post-exposure. We confirmed the PCR findings by in situ hybridization for Brain-derived neurotrophic factor (Bdnf), Homer-1, as well as the glutamate NMDA receptor Grin1, all involved in neurogenesis and plasticity. These results suggest that Bdnf, Homer-1 and Grin1 play important roles in synaptic remodeling and homeostasis in the cochlear nucleus following severe noise-induced afferent degeneration.
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Affiliation(s)
- S Manohar
- University at Buffalo, Center for Hearing and Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States
| | - P V Ramchander
- University at Buffalo, Center for Hearing and Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States
| | - R Salvi
- University at Buffalo, Center for Hearing and Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States.
| | - G M Seigel
- University at Buffalo, Center for Hearing and Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States
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38
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Meloni EG, Kaye KT, Venkataraman A, Carlezon WA. PACAP increases Arc/Arg 3.1 expression within the extended amygdala after fear conditioning in rats. Neurobiol Learn Mem 2018; 157:24-34. [PMID: 30458282 DOI: 10.1016/j.nlm.2018.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 11/09/2018] [Accepted: 11/16/2018] [Indexed: 11/24/2022]
Abstract
The stress-related neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is implicated in neuromodulation of learning and memory. PACAP can alter synaptic plasticity and has direct actions on neurons in the amygdala and hippocampus that could contribute to its acute and persistent effects on the consolidation and expression of conditioned fear. We recently demonstrated that intracerebroventricular (ICV) infusion of PACAP prior to fear conditioning (FC) results in initial amnestic-like effects followed by hyper-expression of conditioned freezing with repeated testing, and analyses of immediate-early gene c-Fos expression suggested that the central nucleus of the amygdala (CeA), but not the lateral/basolateral amygdala (LA/BLA) or hippocampus, are involved in these PACAP effects. Here, we extend that work by examining the expression of the synaptic plasticity marker activity-regulated cytoskeleton-associated protein (Arc/Arg 3.1) after PACAP administration and FC. Male Sprague-Dawley rats were implanted with cannula for ICV infusion of PACAP-38 (1.5 µg) or vehicle followed by FC and tests for conditioned freezing. One hour after FC, Arc protein expression was significantly elevated in the CeA and bed nucleus of the stria terminalis (BNST), interconnected structures that are key elements of the extended amygdala, in rats that received the combination of PACAP + FC. In contrast, Arc expression within the subdivisions of the hippocampus, or the LA/BLA, were unchanged. A subpopulation of Arc-positive cells in both the CeA and BNST also express PKCdelta, an intracellular marker that has been used to identify microcircuits that gate conditioned fear in the CeA. Consistent with our previous findings, on the following day conditioned freezing behavior was reduced in rats that had been given the combination of PACAP + FC-an amnestic-like effect-and Arc expression levels had returned to baseline. Given the established role of Arc in modifying synaptic plasticity and memory formation, our findings suggest that PACAP-induced overexpression of Arc following fear conditioning may disrupt neuroplastic changes within populations of CeA and BNST neurons normally responsible for encoding fear-related cues that, in this case, results in altered fear memory consolidation. Hence, PACAP systems may represent an axis on which stress and experience-driven neurotransmission converge to alter emotional memory, and mediate pathologies that are characteristic of psychiatric illnesses such as post-traumatic stress disorder.
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Affiliation(s)
- Edward G Meloni
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA 02478, United States.
| | - Karen T Kaye
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA 02478, United States
| | - Archana Venkataraman
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA 02478, United States
| | - William A Carlezon
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA 02478, United States
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39
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Regulation of AMPA receptor trafficking and exit from the endoplasmic reticulum. Mol Cell Neurosci 2018; 91:3-9. [PMID: 29545119 DOI: 10.1016/j.mcn.2018.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 02/06/2023] Open
Abstract
A fundamental property of the brain is its ability to modify its function in response to its own activity. This ability for self-modification depends to a large extent on synaptic plasticity. It is now appreciated that for excitatory synapses, a significant part of synaptic plasticity depends upon changes in the post synaptic response to glutamate released from nerve terminals. Modification of the post synaptic response depends, in turn, on changes in the abundances of AMPA receptors in the post synaptic membrane. In this review, we consider mechanisms of trafficking of AMPA receptors to and from synapses that take place in the early trafficking stages, starting in the endoplasmic reticulum (ER) and continuing into the secretory pathway. We consider mechanisms of AMPA receptor assembly in the ER, highlighting the role of protein synthesis and the selective properties of specific AMPA receptor subunits, as well as regulation of ER exit, including the roles of chaperones and accessory proteins and the incorporation of AMPA receptors into COPII vesicles. We consider these processes in the context of the mechanism of mGluR LTD and discuss a compelling role for the dendritic ER membrane that is found proximal to synapses. The review illustrates the important, yet little studied, contribution of the early stages of AMPA receptor trafficking to synaptic plasticity.
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