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Correa E, Mialon M, Cizeron M, Bessereau JL, Pinan-Lucarre B, Kratsios P. UNC-30/PITX coordinates neurotransmitter identity with postsynaptic GABA receptor clustering. Development 2024; 151:dev202733. [PMID: 39190555 PMCID: PMC11385328 DOI: 10.1242/dev.202733] [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: 01/26/2024] [Accepted: 07/10/2024] [Indexed: 08/29/2024]
Abstract
Terminal selectors are transcription factors that control neuronal identity by regulating expression of key effector molecules, such as neurotransmitter biosynthesis proteins and ion channels. Whether and how terminal selectors control neuronal connectivity is poorly understood. Here, we report that UNC-30 (PITX2/3), the terminal selector of GABA nerve cord motor neurons in Caenorhabditis elegans, is required for neurotransmitter receptor clustering, a hallmark of postsynaptic differentiation. Animals lacking unc-30 or madd-4B, the short isoform of the motor neuron-secreted synapse organizer madd-4 (punctin/ADAMTSL), display severe GABA receptor type A (GABAAR) clustering defects in postsynaptic muscle cells. Mechanistically, UNC-30 acts directly to induce and maintain transcription of madd-4B and GABA biosynthesis genes (e.g. unc-25/GAD, unc-47/VGAT). Hence, UNC-30 controls GABAA receptor clustering in postsynaptic muscle cells and GABA biosynthesis in presynaptic cells, transcriptionally coordinating two crucial processes for GABA neurotransmission. Further, we uncover multiple target genes and a dual role for UNC-30 as both an activator and a repressor of gene transcription. Our findings on UNC-30 function may contribute to our molecular understanding of human conditions, such as Axenfeld-Rieger syndrome, caused by PITX2 and PITX3 gene variants.
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Affiliation(s)
- Edgar Correa
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
- Committee on Cell and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Morgane Mialon
- Melis, Universite Claude Bernard Lyon 1, CNRS UMR5284, INSERM U1314, Institut NeuroMyoGene - Faculte de Medecine et de Pharmacie, 69008 Lyon, France
| | - Mélissa Cizeron
- Melis, Universite Claude Bernard Lyon 1, CNRS UMR5284, INSERM U1314, Institut NeuroMyoGene - Faculte de Medecine et de Pharmacie, 69008 Lyon, France
| | - Jean-Louis Bessereau
- Melis, Universite Claude Bernard Lyon 1, CNRS UMR5284, INSERM U1314, Institut NeuroMyoGene - Faculte de Medecine et de Pharmacie, 69008 Lyon, France
| | - Berangere Pinan-Lucarre
- Melis, Universite Claude Bernard Lyon 1, CNRS UMR5284, INSERM U1314, Institut NeuroMyoGene - Faculte de Medecine et de Pharmacie, 69008 Lyon, France
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
- Committee on Cell and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
- University of Chicago Neuroscience Institute, Chicago, IL 60637, USA
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2
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Correa E, Mialon M, Cizeron M, Bessereau JL, Pinan-Lucarre B, Kratsios P. UNC-30/PITX coordinates neurotransmitter identity with postsynaptic GABA receptor clustering. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580278. [PMID: 38405977 PMCID: PMC10888783 DOI: 10.1101/2024.02.14.580278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Terminal selectors are transcription factors that control neuronal identity by regulating the expression of key effector molecules, such as neurotransmitter (NT) biosynthesis proteins, ion channels and neuropeptides. Whether and how terminal selectors control neuronal connectivity is poorly understood. Here, we report that UNC-30 (PITX2/3), the terminal selector of GABA motor neuron identity in C. elegans , is required for NT receptor clustering, a hallmark of postsynaptic differentiation. Animals lacking unc-30 or madd-4B, the short isoform of the MN-secreted synapse organizer madd-4 ( Punctin/ADAMTSL ), display severe GABA receptor type A (GABA A R) clustering defects in postsynaptic muscle cells. Mechanistically, UNC-30 acts directly to induce and maintain transcription of madd-4B and GABA biosynthesis genes (e.g., unc-25/GAD , unc-47/VGAT ). Hence, UNC-30 controls GABA A R clustering on postsynaptic muscle cells and GABA biosynthesis in presynaptic cells, transcriptionally coordinating two critical processes for GABA neurotransmission. Further, we uncover multiple target genes and a dual role for UNC-30 both as an activator and repressor of gene transcription. Our findings on UNC-30 function may contribute to our molecular understanding of human conditions, such as Axenfeld-Rieger syndrome, caused by PITX2 and PITX3 gene mutations.
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3
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Eugenín J, Eugenín-von Bernhardi L, von Bernhardi R. Age-dependent changes on fractalkine forms and their contribution to neurodegenerative diseases. Front Mol Neurosci 2023; 16:1249320. [PMID: 37818457 PMCID: PMC10561274 DOI: 10.3389/fnmol.2023.1249320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/06/2023] [Indexed: 10/12/2023] Open
Abstract
The chemokine fractalkine (FKN, CX3CL1), a member of the CX3C subfamily, contributes to neuron-glia interaction and the regulation of microglial cell activation. Fractalkine is expressed by neurons as a membrane-bound protein (mCX3CL1) that can be cleaved by extracellular proteases generating several sCX3CL1 forms. sCX3CL1, containing the chemokine domain, and mCX3CL1 have high affinity by their unique receptor (CX3CR1) which, physiologically, is only found in microglia, a resident immune cell of the CNS. The activation of CX3CR1contributes to survival and maturation of the neural network during development, glutamatergic synaptic transmission, synaptic plasticity, cognition, neuropathic pain, and inflammatory regulation in the adult brain. Indeed, the various CX3CL1 forms appear in some cases to serve an anti-inflammatory role of microglia, whereas in others, they have a pro-inflammatory role, aggravating neurological disorders. In the last decade, evidence points to the fact that sCX3CL1 and mCX3CL1 exhibit selective and differential effects on their targets. Thus, the balance in their level and activity will impact on neuron-microglia interaction. This review is focused on the description of factors determining the emergence of distinct fractalkine forms, their age-dependent changes, and how they contribute to neuroinflammation and neurodegenerative diseases. Changes in the balance among various fractalkine forms may be one of the mechanisms on which converge aging, chronic CNS inflammation, and neurodegeneration.
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Affiliation(s)
- Jaime Eugenín
- Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, Santiago, Chile
| | | | - Rommy von Bernhardi
- Facultad de Ciencias para el Cuidado de la Salud, Universidad San Sebastián, Santiago, Chile
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4
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Extracellular matrix and synapse formation. Biosci Rep 2023; 43:232259. [PMID: 36503961 PMCID: PMC9829651 DOI: 10.1042/bsr20212411] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 11/08/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
The extracellular matrix (ECM) is a complex molecular network distributed throughout the extracellular space of different tissues as well as the neuronal system. Previous studies have identified various ECM components that play important roles in neuronal maturation and signal transduction. ECM components are reported to be involved in neurogenesis, neuronal migration, and axonal growth by interacting or binding to specific receptors. In addition, the ECM is found to regulate synapse formation, the stability of the synaptic structure, and synaptic plasticity. Here, we mainly reviewed the effects of various ECM components on synapse formation and briefly described the related diseases caused by the abnormality of several ECM components.
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DePew AT, Mosca TJ. Conservation and Innovation: Versatile Roles for LRP4 in Nervous System Development. J Dev Biol 2021; 9:9. [PMID: 33799485 PMCID: PMC8006230 DOI: 10.3390/jdb9010009] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 02/07/2023] Open
Abstract
As the nervous system develops, connections between neurons must form to enable efficient communication. This complex process of synaptic development requires the coordination of a series of intricate mechanisms between partner neurons to ensure pre- and postsynaptic differentiation. Many of these mechanisms employ transsynaptic signaling via essential secreted factors and cell surface receptors to promote each step of synaptic development. One such cell surface receptor, LRP4, has emerged as a synaptic organizer, playing a critical role in conveying extracellular signals to initiate diverse intracellular events during development. To date, LRP4 is largely known for its role in development of the mammalian neuromuscular junction, where it functions as a receptor for the synaptogenic signal Agrin to regulate synapse development. Recently however, LRP4 has emerged as a synapse organizer in the brain, where new functions for the protein continue to arise, adding further complexity to its already versatile roles. Additional findings indicate that LRP4 plays a role in disorders of the nervous system, including myasthenia gravis, amyotrophic lateral sclerosis, and Alzheimer's disease, demonstrating the need for further study to understand disease etiology. This review will highlight our current knowledge of how LRP4 functions in the nervous system, focusing on the diverse developmental roles and different modes this essential cell surface protein uses to ensure the formation of robust synaptic connections.
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Affiliation(s)
| | - Timothy J. Mosca
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA;
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6
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Suzuki K, Elegheert J, Song I, Sasakura H, Senkov O, Matsuda K, Kakegawa W, Clayton AJ, Chang VT, Ferrer-Ferrer M, Miura E, Kaushik R, Ikeno M, Morioka Y, Takeuchi Y, Shimada T, Otsuka S, Stoyanov S, Watanabe M, Takeuchi K, Dityatev A, Aricescu AR, Yuzaki M. A synthetic synaptic organizer protein restores glutamatergic neuronal circuits. Science 2020; 369:369/6507/eabb4853. [PMID: 32855309 PMCID: PMC7116145 DOI: 10.1126/science.abb4853] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/24/2020] [Indexed: 12/18/2022]
Abstract
Neuronal synapses undergo structural and functional changes throughout life, which are essential for nervous system physiology. However, these changes may also perturb the excitatory-inhibitory neurotransmission balance and trigger neuropsychiatric and neurological disorders. Molecular tools to restore this balance are highly desirable. Here, we designed and characterized CPTX, a synthetic synaptic organizer combining structural elements from cerebellin-1 and neuronal pentraxin-1. CPTX can interact with presynaptic neurexins and postsynaptic AMPA-type ionotropic glutamate receptors and induced the formation of excitatory synapses both in vitro and in vivo. CPTX restored synaptic functions, motor coordination, spatial and contextual memories, and locomotion in mouse models for cerebellar ataxia, Alzheimer's disease, and spinal cord injury, respectively. Thus, CPTX represents a prototype for structure-guided biologics that can efficiently repair or remodel neuronal circuits.
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Affiliation(s)
- Kunimichi Suzuki
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Jonathan Elegheert
- Division of Structural Biology, University of Oxford, Oxford OX3 7BN, UK
| | - Inseon Song
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Hiroyuki Sasakura
- Department of Medical Cell Biology, School of Medicine, Aichi Medical University, Aichi, Japan
| | - Oleg Senkov
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Keiko Matsuda
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Wataru Kakegawa
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Amber J Clayton
- Division of Structural Biology, University of Oxford, Oxford OX3 7BN, UK
| | - Veronica T Chang
- Division of Structural Biology, University of Oxford, Oxford OX3 7BN, UK
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Maura Ferrer-Ferrer
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Eriko Miura
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Rahul Kaushik
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
| | - Masashi Ikeno
- Department of Medical Cell Biology, School of Medicine, Aichi Medical University, Aichi, Japan
| | - Yuki Morioka
- Department of Medical Cell Biology, School of Medicine, Aichi Medical University, Aichi, Japan
| | - Yuka Takeuchi
- Department of Medical Cell Biology, School of Medicine, Aichi Medical University, Aichi, Japan
| | - Tatsuya Shimada
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Shintaro Otsuka
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Stoyan Stoyanov
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Kosei Takeuchi
- Department of Medical Cell Biology, School of Medicine, Aichi Medical University, Aichi, Japan
| | - Alexander Dityatev
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany.
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
- Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany
| | - A Radu Aricescu
- Division of Structural Biology, University of Oxford, Oxford OX3 7BN, UK.
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan.
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7
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Briatore F, Pregno G, Di Angelantonio S, Frola E, De Stefano ME, Vaillend C, Sassoè-Pognetto M, Patrizi A. Dystroglycan Mediates Clustering of Essential GABAergic Components in Cerebellar Purkinje Cells. Front Mol Neurosci 2020; 13:164. [PMID: 32982691 PMCID: PMC7485281 DOI: 10.3389/fnmol.2020.00164] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/11/2020] [Indexed: 01/02/2023] Open
Abstract
Muscle dystrophin–glycoprotein complex (DGC) links the intracellular cytoskeleton to the extracellular matrix. In neurons, dystroglycan and dystrophin, two major components of the DGC, localize in a subset of GABAergic synapses, where their function is unclear. Here we used mouse models to analyze the specific role of the DGC in the organization and function of inhibitory synapses. Loss of full-length dystrophin in mdx mice resulted in a selective depletion of the transmembrane β-dystroglycan isoform from inhibitory post-synaptic sites in cerebellar Purkinje cells. Remarkably, there were no differences in the synaptic distribution of the extracellular α-dystroglycan subunit, of GABAA receptors and neuroligin 2. In contrast, conditional deletion of the dystroglycan gene from Purkinje cells caused a disruption of the DGC and severely impaired post-synaptic clustering of neuroligin 2, GABAA receptors and scaffolding proteins. Accordingly, whole-cell patch-clamp analysis revealed a significant reduction in the frequency and amplitude of spontaneous IPSCs recorded from Purkinje cells. In the long-term, deletion of dystroglycan resulted in a significant decrease of GABAergic innervation of Purkinje cells and caused an impairment of motor learning functions. These results show that dystroglycan is an essential synaptic organizer at GABAergic synapses in Purkinje cells.
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Affiliation(s)
- Federica Briatore
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Giulia Pregno
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,Center for Life Nanoscience, Istituto Italiano di Tecnologia, Rome, Italy
| | - Elena Frola
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Maria Egle De Stefano
- Department of Biology and Biotechnology "Charles Darwin", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Cyrille Vaillend
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Marco Sassoè-Pognetto
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy
| | - Annarita Patrizi
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, Turin, Italy.,Schaller Research Group Leader at the German Cancer Research Center, Heidelberg, Germany
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8
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Hoover KM, Gratz SJ, Qi N, Herrmann KA, Liu Y, Perry-Richardson JJ, Vanderzalm PJ, O'Connor-Giles KM, Broihier HT. The calcium channel subunit α 2δ-3 organizes synapses via an activity-dependent and autocrine BMP signaling pathway. Nat Commun 2019; 10:5575. [PMID: 31811118 PMCID: PMC6898181 DOI: 10.1038/s41467-019-13165-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/23/2019] [Indexed: 12/17/2022] Open
Abstract
Synapses are highly specialized for neurotransmitter signaling, yet activity-dependent growth factor release also plays critical roles at synapses. While efficient neurotransmitter signaling relies on precise apposition of release sites and neurotransmitter receptors, molecular mechanisms enabling high-fidelity growth factor signaling within the synaptic microenvironment remain obscure. Here we show that the auxiliary calcium channel subunit α2δ-3 promotes the function of an activity-dependent autocrine Bone Morphogenetic Protein (BMP) signaling pathway at the Drosophila neuromuscular junction (NMJ). α2δ proteins have conserved synaptogenic activity, although how they execute this function has remained elusive. We find that α2δ-3 provides an extracellular scaffold for an autocrine BMP signal, suggesting a mechanistic framework for understanding α2δ's conserved role in synapse organization. We further establish a transcriptional requirement for activity-dependent, autocrine BMP signaling in determining synapse density, structure, and function. We propose that activity-dependent, autocrine signals provide neurons with continuous feedback on their activity state for modulating both synapse structure and function.
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Affiliation(s)
- Kendall M Hoover
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Scott J Gratz
- Department of Neuroscience, Brown University, Providence, RI, 02912, USA
| | - Nova Qi
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Kelsey A Herrmann
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Yizhou Liu
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Jahci J Perry-Richardson
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Pamela J Vanderzalm
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA
| | | | - Heather T Broihier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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9
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Kudryashova IV. The Molecular Basis of Destabilization of Synapses as a Factor of Structural Plasticity. NEUROCHEM J+ 2019. [DOI: 10.1134/s1819712419010136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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10
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Nagappan-Chettiar S, Johnson-Venkatesh EM, Umemori H. Tyrosine phosphorylation of the transmembrane protein SIRPα: Sensing synaptic activity and regulating ectodomain cleavage for synapse maturation. J Biol Chem 2018; 293:12026-12042. [PMID: 29914984 DOI: 10.1074/jbc.ra117.001488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 06/08/2018] [Indexed: 11/06/2022] Open
Abstract
Synapse maturation is a neural activity-dependent process during brain development, in which active synapses preferentially undergo maturation to establish efficient neural circuits in the brain. Defects in this process are implicated in various neuropsychiatric disorders. We have previously reported that a postsynaptic transmembrane protein, signal regulatory protein-α (SIRPα), plays an important role in activity-dependently directing synapse maturation. In the presence of synaptic activity, the ectodomain of SIRPα is cleaved and released and then acts as a retrograde signal to induce presynaptic maturation. However, how SIRPα detects synaptic activity to promote its ectodomain cleavage and synapse maturation is unknown. Here, we show that activity-dependent tyrosine phosphorylation of SIRPα is critical for SIRPα cleavage and synapse maturation. We found that during synapse maturation and in response to neural activity, SIRPα is highly phosphorylated on its tyrosine residues in the hippocampus, a structure critical for learning and memory. Tyrosine phosphorylation of SIRPα was necessary for SIRPα cleavage and presynaptic maturation, as indicated by the fact that a phosphorylation-deficient SIRPα variant underwent much less cleavage and could not drive presynaptic maturation. However, SIRPα phosphorylation did not affect its synaptic localization. Finally, we show that inhibitors of the Src and JAK kinase family suppress neural activity-dependent SIRPα phosphorylation and cleavage. Together, our results indicate that SIRPα phosphorylation serves as a mechanism for detecting synaptic activity and linking it to the ectodomain cleavage of SIRPα, which in turn drives synapse maturation in an activity-dependent manner.
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Affiliation(s)
- Sivapratha Nagappan-Chettiar
- Department of Neurology, F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115; Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115
| | - Erin M Johnson-Venkatesh
- Department of Neurology, F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115
| | - Hisashi Umemori
- Department of Neurology, F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115; Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115.
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11
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Hesse R, von Einem B, Wagner F, Bott P, Schwanzar D, Jackson RJ, Föhr KJ, Lausser L, Kroker KS, Proepper C, Walther P, Kestler HA, Spires-Jones TL, Boeckers T, Rosenbrock H, von Arnim CAF. sAPPβ and sAPPα increase structural complexity and E/I input ratio in primary hippocampal neurons and alter Ca 2+ homeostasis and CREB1-signaling. Exp Neurol 2018; 304:1-13. [PMID: 29466703 DOI: 10.1016/j.expneurol.2018.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/09/2018] [Accepted: 02/14/2018] [Indexed: 12/23/2022]
Abstract
One major pathophysiological hallmark of Alzheimer's disease (AD) is senile plaques composed of amyloid β (Aβ). In the amyloidogenic pathway, cleavage of the amyloid precursor protein (APP) is shifted towards Aβ production and soluble APPβ (sAPPβ) levels. Aβ is known to impair synaptic function; however, much less is known about the physiological functions of sAPPβ. The neurotrophic properties of sAPPα, derived from the non-amyloidogenic pathway of APP cleavage, are well-established, whereas only a few, conflicting studies on sAPPβ exist. The intracellular pathways of sAPPβ are largely unknown. Since sAPPβ is generated alongside Aβ by β-secretase (BACE1) cleavage, we tested the hypothesis that sAPPβ effects differ from sAPPα effects as a neurotrophic factor. We therefore performed a head-to-head comparison of both mammalian recombinant peptides in developing primary hippocampal neurons (PHN). We found that sAPPα significantly increases axon length (p = 0.0002) and that both sAPPα and sAPPβ increase neurite number (p < 0.0001) of PHN at 7 days in culture (DIV7) but not at DIV4. Moreover, both sAPPα- and sAPPβ-treated neurons showed a higher neuritic complexity in Sholl analysis. The number of glutamatergic synapses (p < 0.0001), as well as layer thickness of postsynaptic densities (PSDs), were significantly increased, and GABAergic synapses decreased upon sAPP overexpression in PHN. Furthermore, we showed that sAPPα enhances ERK and CREB1 phosphorylation upon glutamate stimulation at DIV7, but not DIV4 or DIV14. These neurotrophic effects are further associated with increased glutamate sensitivity and CREB1-signaling. Finally, we found that sAPPα levels are significantly reduced in brain homogenates of AD patients compared to control subjects. Taken together, our data indicate critical stage-dependent roles of sAPPs in the developing glutamatergic system in vitro, which might help to understand deleterious consequences of altered APP shedding in AD patients, beyond Aβ pathophysiology.
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Affiliation(s)
- Raphael Hesse
- Department of Neurology, Ulm University, Ulm, Germany
| | | | | | - Patricia Bott
- Department of Neurology, Ulm University, Ulm, Germany
| | | | - Rosemary J Jackson
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | | | - Ludwig Lausser
- Institute of Medical Systems Biology, Ulm University, Ulm, Germany
| | - Katja S Kroker
- Boehringer Ingelheim Pharma GmbH & Co KG, Dept. of Drug Discovery Sciences, Biberach, Germany
| | | | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Ulm, Germany
| | - Hans A Kestler
- Institute of Medical Systems Biology, Ulm University, Ulm, Germany
| | | | - Tobias Boeckers
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Holger Rosenbrock
- Boehringer Ingelheim Pharma GmbH & Co KG, Dept. of CNS Diseases Research, Biberach, Germany
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12
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Hillen AEJ, Burbach JPH, Hol EM. Cell adhesion and matricellular support by astrocytes of the tripartite synapse. Prog Neurobiol 2018; 165-167:66-86. [PMID: 29444459 DOI: 10.1016/j.pneurobio.2018.02.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/25/2017] [Accepted: 02/07/2018] [Indexed: 12/18/2022]
Abstract
Astrocytes contribute to the formation, function, and plasticity of synapses. Their processes enwrap the neuronal components of the tripartite synapse, and due to this close interaction they are perfectly positioned to modulate neuronal communication. The interaction between astrocytes and synapses is facilitated by cell adhesion molecules and matricellular proteins, which have been implicated in the formation and functioning of tripartite synapses. The importance of such neuron-astrocyte integration at the synapse is underscored by the emerging role of astrocyte dysfunction in synaptic pathologies such as autism and schizophrenia. Here we review astrocyte-expressed cell adhesion molecules and matricellular molecules that play a role in integration of neurons and astrocytes within the tripartite synapse.
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Affiliation(s)
- Anne E J Hillen
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Department of Pediatrics/Child Neurology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - J Peter H Burbach
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1098 XH Amsterdam, The Netherlands; Department of Neuroimmunology, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands.
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13
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Jamann N, Jordan M, Engelhardt M. Activity-dependent axonal plasticity in sensory systems. Neuroscience 2017; 368:268-282. [PMID: 28739523 DOI: 10.1016/j.neuroscience.2017.07.035] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 06/23/2017] [Accepted: 07/14/2017] [Indexed: 12/21/2022]
Abstract
The rodent whisker-to-barrel cortex pathway is a classic model to study the effects of sensory experience and deprivation on neuronal circuit formation, not only during development but also in the adult. Decades of research have produced a vast body of evidence highlighting the fundamental role of neuronal activity (spontaneous and/or sensory-evoked) for circuit formation and function. In this context, it has become clear that neuronal adaptation and plasticity is not just a function of the neonatal brain, but persists into adulthood, especially after experience-driven modulation of network status. Mechanisms for structural remodeling of the somatodendritic or axonal domain include microscale alterations of neurites or synapses. At the same time, functional alterations at the nanoscale such as expression or activation changes of channels and receptors contribute to the modulation of intrinsic excitability or input-output relationships. However, it remains elusive how these forms of structural and functional plasticity come together to shape neuronal network formation and function. While specifically somatodendritic plasticity has been studied in great detail, the role of axonal plasticity, (e.g. at presynaptic boutons, branches or axonal microdomains), is rather poorly understood. Therefore, this review will only briefly highlight somatodendritic plasticity and instead focus on axonal plasticity. We discuss (i) the role of spontaneous and sensory-evoked plasticity during critical periods, (ii) the assembly of axonal presynaptic sites, (iii) axonal plasticity in the mature brain under baseline and sensory manipulation conditions, and finally (iv) plasticity of electrogenic axonal microdomains, namely the axon initial segment, during development and in the mature CNS.
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Affiliation(s)
- Nora Jamann
- Institute of Neuroanatomy, Medical Faculty Mannheim, CBTM, Heidelberg University, Germany
| | - Merryn Jordan
- Institute of Neuroanatomy, Medical Faculty Mannheim, CBTM, Heidelberg University, Germany
| | - Maren Engelhardt
- Institute of Neuroanatomy, Medical Faculty Mannheim, CBTM, Heidelberg University, Germany.
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14
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Neurotrophin-3 Regulates Synapse Development by Modulating TrkC-PTPσ Synaptic Adhesion and Intracellular Signaling Pathways. J Neurosci 2017; 36:4816-31. [PMID: 27122038 DOI: 10.1523/jneurosci.4024-15.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/20/2016] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Neurotrophin-3 (NT-3) is a secreted neurotrophic factor that binds neurotrophin receptor tyrosine kinase C (TrkC), which in turn binds to presynaptic protein tyrosine phosphatase σ (PTPσ) to govern excitatory synapse development. However, whether and how NT-3 cooperates with the TrkC-PTPσ synaptic adhesion pathway and TrkC-mediated intracellular signaling pathways in rat cultured neurons has remained unclear. Here, we report that NT-3 enhances TrkC binding affinity for PTPσ. Strikingly, NT-3 treatment bidirectionally regulates the synaptogenic activity of TrkC: at concentrations of 10-25 ng/ml, NT-3 further enhanced the increase in synapse density induced by TrkC overexpression, whereas at higher concentrations, NT-3 abrogated TrkC-induced increases in synapse density. Semiquantitative immunoblotting and optogenetics-based imaging showed that 25 ng/ml NT-3 or light stimulation at a power that produced a comparable level of NT-3 (6.25 μW) activated only extracellular signal-regulated kinase (ERK) and Akt, whereas 100 ng/ml NT-3 (light intensity, 25 μW) further triggered the activation of phospholipase C-γ1 and CREB independently of PTPσ. Notably, disruption of TrkC intracellular signaling pathways, extracellular ligand binding, or kinase activity by point mutations compromised TrkC-induced increases in synapse density. Furthermore, only sparse, but not global, TrkC knock-down in cultured rat neurons significantly decreased synapse density, suggesting that intercellular differences in TrkC expression level are critical for its synapse-promoting action. Together, our data demonstrate that NT-3 is a key factor in excitatory synapse development that may direct higher-order assembly of the TrkC/PTPσ complex and activate distinct intracellular signaling cascades in a concentration-dependent manner to promote competition-based synapse development processes. SIGNIFICANCE STATEMENT In this study, we present several lines of experimental evidences to support the conclusion that neurotrophin-3 (NT-3) modulates the synaptic adhesion pathway involving neurotrophin receptor tyrosine kinase C (TrkC) and presynaptic protein tyrosine phosphatase σ (PTPσ) in a bidirectional manner at excitatory synapses. NT-3 acts in concentration-independent manner to facilitate TrkC-mediated presynaptic differentiation, whereas it acts in a concentration-dependent manner to exert differential effects on TrkC-mediated organization of postsynaptic development. We further investigated TrkC extracellular ligand binding, intracellular signaling pathways, and kinase activity in NT-3-induced synapse development. Last, we found that interneuronal differences in TrkC levels regulate the synapse number. Overall, these results suggest that NT-3 functions as a positive modulator of synaptogenesis involving TrkC and PTPσ.
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15
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Rigoni M, Montecucco C. Animal models for studying motor axon terminal paralysis and recovery. J Neurochem 2017; 142 Suppl 2:122-129. [PMID: 28326543 DOI: 10.1111/jnc.13956] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 12/16/2022]
Abstract
An extraordinary property of the peripheral nervous system is that nerve terminals can regenerate after damage caused by different physical, chemical, or biological pathogens. Regeneration is the result of a complex and ill-known interplay among the nerve, the glia, the muscle, the basal lamina and, in some cases, the immune system. This phenomenon has been studied using different injury models mainly in rodents, particularly in mice, where a lesion can be produced in a chosen anatomical area. These approaches differ significantly among them for the nature of the lesion and the final outcomes. We have reviewed here the most common experimental models employed to induce motor axon injury, the relative advantages and drawbacks, and the principal read-outs used to monitor the regenerative process. Recently introduced tools for inducing reversible damage to the motor axon terminal that overcome some of the drawbacks of the more classical approaches are also discussed. Animal models have provided precious information about the cellular components involved in the regenerative process and on its electrophysiological features. Methods and tools made available recently allow one to identify and study molecules that are involved in the crosstalk among the components of the endplate. The time-course of the intercellular signaling and of the intracellular pathways activated will draw a picture of the entire process of regeneration as seen from a privileged anatomical site of observation. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Michela Rigoni
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,CNR Institute of Neuroscience, Padua, Italy
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16
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Matsuda K. Synapse organization and modulation via C1q family proteins and their receptors in the central nervous system. Neurosci Res 2017; 116:46-53. [DOI: 10.1016/j.neures.2016.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 09/29/2016] [Accepted: 09/30/2016] [Indexed: 10/20/2022]
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17
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Nagappan-Chettiar S, Johnson-Venkatesh EM, Umemori H. Activity-dependent proteolytic cleavage of cell adhesion molecules regulates excitatory synaptic development and function. Neurosci Res 2017; 116:60-69. [PMID: 27965136 PMCID: PMC5376514 DOI: 10.1016/j.neures.2016.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 01/21/2023]
Abstract
Activity-dependent remodeling of neuronal connections is critical to nervous system development and function. These processes rely on the ability of synapses to detect neuronal activity and translate it into the appropriate molecular signals. One way to convert neuronal activity into downstream signaling is the proteolytic cleavage of cell adhesion molecules (CAMs). Here we review studies demonstrating the mechanisms by which proteolytic processing of CAMs direct the structural and functional remodeling of excitatory glutamatergic synapses during development and plasticity. Specifically, we examine how extracellular proteolytic cleavage of CAMs switches on or off molecular signals to 1) permit, drive, or restrict synaptic maturation during development and 2) strengthen or weaken synapses during adult plasticity. We will also examine emerging studies linking improper activity-dependent proteolytic processing of CAMs to neurological disorders such as schizophrenia, brain tumors, and Alzheimer's disease. Together these findings suggest that the regulation of activity-dependent proteolytic cleavage of CAMs is vital to proper brain development and lifelong function.
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Affiliation(s)
- Sivapratha Nagappan-Chettiar
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Erin M Johnson-Venkatesh
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA.
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18
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Kitahara Y, Nishi A. Antidepressant-induced changes in synaptic morphology in the mouse dentate gyrus. Nihon Yakurigaku Zasshi 2016; 148:180-184. [PMID: 27725565 DOI: 10.1254/fpj.148.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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19
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The Purkinje cell as a model of synaptogenesis and synaptic specificity. Brain Res Bull 2016; 129:12-17. [PMID: 27721030 DOI: 10.1016/j.brainresbull.2016.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/28/2016] [Accepted: 10/05/2016] [Indexed: 01/03/2023]
Abstract
Since the groundbreaking work of Ramon y Cajal, the cerebellar Purkinje cell has always represented an ideal model for studying the organization, development and function of synaptic circuits. Purkinje cells receive distinct types of glutamatergic and GABAergic synapses, each characterized by exquisite sub-cellular and molecular specificity. The formation and refinement of these connections results from a temporally-regulated sequence of events that involves molecular interactions between distinct sets of secreted and surface proteins, as well as activity-dependent competition between converging inputs. Insights into the mechanisms controlling synaptic specificity in Purkinje cells may help understand synapse development also in other brain regions and disclose circuit abnormalities that underlie neurodevelopmental disorders.
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20
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Cheng C, Lau SKM, Doering LC. Astrocyte-secreted thrombospondin-1 modulates synapse and spine defects in the fragile X mouse model. Mol Brain 2016; 9:74. [PMID: 27485117 PMCID: PMC4971702 DOI: 10.1186/s13041-016-0256-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/15/2016] [Indexed: 01/24/2023] Open
Abstract
Astrocytes are key participants in various aspects of brain development and function, many of which are executed via secreted proteins. Defects in astrocyte signaling are implicated in neurodevelopmental disorders characterized by abnormal neural circuitry such as Fragile X syndrome (FXS). In animal models of FXS, the loss in expression of the Fragile X mental retardation 1 protein (FMRP) from astrocytes is associated with delayed dendrite maturation and improper synapse formation; however, the effect of astrocyte-derived factors on the development of neurons is not known. Thrombospondin-1 (TSP-1) is an important astrocyte-secreted protein that is involved in the regulation of spine development and synaptogenesis. In this study, we found that cultured astrocytes isolated from an Fmr1 knockout (Fmr1 KO) mouse model of FXS displayed a significant decrease in TSP-1 protein expression compared to the wildtype (WT) astrocytes. Correspondingly, Fmr1 KO hippocampal neurons exhibited morphological deficits in dendritic spines and alterations in excitatory synapse formation following long-term culture. All spine and synaptic abnormalities were prevented in the presence of either astrocyte-conditioned media or a feeder layer derived from FMRP-expressing astrocytes, or following the application of exogenous TSP-1. Importantly, this work demonstrates the integral role of astrocyte-secreted signals in the establishment of neuronal communication and identifies soluble TSP-1 as a potential therapeutic target for Fragile X syndrome.
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Affiliation(s)
- Connie Cheng
- McMaster Integrative Neuroscience Discovery and Study Program (MINDS), McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L8, Canada.,Department of Pathology and Molecular Medicine, McMaster University, 1200 Main Street West, HSC 1R15A, Hamilton, Ontario, L8N 3Z5, Canada
| | - Sally K M Lau
- Department of Pathology and Molecular Medicine, McMaster University, 1200 Main Street West, HSC 1R15A, Hamilton, Ontario, L8N 3Z5, Canada
| | - Laurie C Doering
- McMaster Integrative Neuroscience Discovery and Study Program (MINDS), McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L8, Canada. .,Department of Pathology and Molecular Medicine, McMaster University, 1200 Main Street West, HSC 1R15A, Hamilton, Ontario, L8N 3Z5, Canada.
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21
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Pinto MJ, Almeida RD. Puzzling out presynaptic differentiation. J Neurochem 2016; 139:921-942. [PMID: 27315450 DOI: 10.1111/jnc.13702] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/27/2016] [Accepted: 06/10/2016] [Indexed: 12/24/2022]
Abstract
Proper brain function in the nervous system relies on the accurate establishment of synaptic contacts during development. Countless synapses populate the adult brain in an orderly fashion. In each synapse, a presynaptic terminal loaded with neurotransmitters-containing synaptic vesicles is perfectly aligned to an array of receptors in the postsynaptic membrane. Presynaptic differentiation, which encompasses the events underlying assembly of new presynaptic units, has seen notable advances in recent years. It is now consensual that as a growing axon encounters the receptive dendrites of its partner, presynaptic assembly will be triggered and specified by multiple postsynaptically-derived factors including soluble molecules and cell adhesion complexes. Presynaptic material that reaches these distant sites by axonal transport in the form of pre-assembled packets will be retained and clustered, ultimately giving rise to a presynaptic bouton. This review focuses on the cellular and molecular aspects of presynaptic differentiation in the central nervous system, with a particular emphasis on the identity of the instructive factors and the intracellular processes used by neuronal cells to assemble functional presynaptic terminals. We provide a detailed description of the mechanisms leading to the formation of new presynaptic terminals. In brief, soma-derived packets of pre-assembled material are trafficked to distant axonal sites. Synaptogenic factors from dendritic or glial provenance activate downstream intra-axonal mediators to trigger clustering of passing material and their correct organization into a new presynaptic bouton. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
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Affiliation(s)
- Maria J Pinto
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ramiro D Almeida
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,School of Allied Health Technologies, Polytechnic Institute of Oporto, Vila Nova de Gaia, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
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22
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Pinto MJ, Pedro JR, Costa RO, Almeida RD. Visualizing K48 Ubiquitination during Presynaptic Formation By Ubiquitination-Induced Fluorescence Complementation (UiFC). Front Mol Neurosci 2016; 9:43. [PMID: 27375430 PMCID: PMC4901079 DOI: 10.3389/fnmol.2016.00043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/24/2016] [Indexed: 11/18/2022] Open
Abstract
In recent years, signaling through ubiquitin has been shown to be of great importance for normal brain development. Indeed, fluctuations in ubiquitin levels and spontaneous mutations in (de)ubiquitination enzymes greatly perturb synapse formation and neuronal transmission. In the brain, expression of lysine (K) 48-linked ubiquitin chains is higher at a developmental stage coincident with synaptogenesis. Nevertheless, no studies have so far delved into the involvement of this type of polyubiquitin chains in synapse formation. We have recently proposed a role for polyubiquitinated conjugates as triggering signals for presynaptic assembly. Herein, we aimed at characterizing the axonal distribution of K48 polyubiquitin and its dynamics throughout the course of presynaptic formation. To accomplish so, we used an ubiquitination-induced fluorescence complementation (UiFC) strategy for the visualization of K48 polyubiquitin in live hippocampal neurons. We first validated its use in neurons by analyzing changing levels of polyubiquitin. UiFC signal is diffusely distributed with distinct aggregates in somas, dendrites and axons, which perfectly colocalize with staining for a K48-specific antibody. Axonal UiFC aggregates are relatively stable and new aggregates are formed as an axon grows. Approximately 65% of UiFC aggregates colocalize with synaptic vesicle clusters and they preferentially appear in the axonal domains of axo-somatodendritic synapses when compared to isolated axons. We then evaluated axonal accumulation of K48 ubiquitinated signals in bead-induced synapses. We observed rapid accumulation of UiFC signal and endogenous K48 ubiquitin at the sites of newly formed presynapses. Lastly, we show by means of a microfluidic platform, for the isolation of axons, that presynaptic clustering on beads is dependent on E1-mediated ubiquitination at the axonal level. Altogether, these results indicate that enrichment of K48 polyubiquitin at the site of nascent presynaptic terminals is an important axon-intrinsic event for presynaptic differentiation.
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Affiliation(s)
- Maria J Pinto
- Center for Neuroscience and Cell Biology (CNC), University of CoimbraCoimbra, Portugal; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of CoimbraCoimbra, Portugal
| | - Joana R Pedro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra Coimbra, Portugal
| | - Rui O Costa
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra Coimbra, Portugal
| | - Ramiro D Almeida
- Center for Neuroscience and Cell Biology (CNC), University of CoimbraCoimbra, Portugal; School of Allied Health Technologies, Polytechnic Institute of Porto (ESTSP-IPP)Vila Nova de Gaia, Portugal; Institute for Interdisciplinary Research, University of CoimbraCoimbra, Portugal
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23
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Terauchi A, Johnson-Venkatesh EM, Bullock B, Lehtinen MK, Umemori H. Retrograde fibroblast growth factor 22 (FGF22) signaling regulates insulin-like growth factor 2 (IGF2) expression for activity-dependent synapse stabilization in the mammalian brain. eLife 2016; 5. [PMID: 27083047 PMCID: PMC4868541 DOI: 10.7554/elife.12151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/14/2016] [Indexed: 02/06/2023] Open
Abstract
Communication between pre- and postsynaptic cells promotes the initial organization of synaptic specializations, but subsequent synaptic stabilization requires transcriptional regulation. Here we show that fibroblast growth factor 22 (FGF22), a target-derived presynaptic organizer in the mouse hippocampus, induces the expression of insulin-like growth factor 2 (IGF2) for the stabilization of presynaptic terminals. FGF22 is released from CA3 pyramidal neurons and organizes the differentiation of excitatory nerve terminals formed onto them. Local application of FGF22 on the axons of dentate granule cells (DGCs), which are presynaptic to CA3 pyramidal neurons, induces IGF2 in the DGCs. IGF2, in turn, localizes to DGC presynaptic terminals and stabilizes them in an activity-dependent manner. IGF2 application rescues presynaptic defects of Fgf22(-/-) cultures. IGF2 is dispensable for the initial presynaptic differentiation, but is required for the following presynaptic stabilization both in vitro and in vivo. These results reveal a novel feedback signal that is critical for the activity-dependent stabilization of presynaptic terminals in the mammalian hippocampus.
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Affiliation(s)
- Akiko Terauchi
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Erin M Johnson-Venkatesh
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Brenna Bullock
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Maria K Lehtinen
- Department of Pathology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
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24
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Kitahara Y, Ohta K, Hasuo H, Shuto T, Kuroiwa M, Sotogaku N, Togo A, Nakamura KI, Nishi A. Chronic Fluoxetine Induces the Enlargement of Perforant Path-Granule Cell Synapses in the Mouse Dentate Gyrus. PLoS One 2016; 11:e0147307. [PMID: 26788851 PMCID: PMC4720354 DOI: 10.1371/journal.pone.0147307] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/01/2016] [Indexed: 12/27/2022] Open
Abstract
A selective serotonin reuptake inhibitor is the most commonly prescribed antidepressant for the treatment of major depression. However, the mechanisms underlying the actions of selective serotonin reuptake inhibitors are not fully understood. In the dentate gyrus, chronic fluoxetine treatment induces increased excitability of mature granule cells (GCs) as well as neurogenesis. The major input to the dentate gyrus is the perforant path axons (boutons) from the entorhinal cortex (layer II). Through voltage-sensitive dye imaging, we found that the excitatory neurotransmission of the perforant path synapse onto the GCs in the middle molecular layer of the mouse dentate gyrus (perforant path-GC synapse) is enhanced after chronic fluoxetine treatment (15 mg/kg/day, 14 days). Therefore, we further examined whether chronic fluoxetine treatment affects the morphology of the perforant path-GC synapse, using FIB/SEM (focused ion beam/scanning electron microscopy). A three-dimensional reconstruction of dendritic spines revealed the appearance of extremely large-sized spines after chronic fluoxetine treatment. The large-sized spines had a postsynaptic density with a large volume. However, chronic fluoxetine treatment did not affect spine density. The presynaptic boutons that were in contact with the large-sized spines were large in volume, and the volumes of the mitochondria and synaptic vesicles inside the boutons were correlated with the size of the boutons. Thus, the large-sized perforant path-GC synapse induced by chronic fluoxetine treatment contains synaptic components that correlate with the synapse size and that may be involved in enhanced glutamatergic neurotransmission.
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Affiliation(s)
- Yosuke Kitahara
- Department of Pharmacology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Keisuke Ohta
- Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Hiroshi Hasuo
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Takahide Shuto
- Department of Pharmacology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Mahomi Kuroiwa
- Department of Pharmacology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Naoki Sotogaku
- Department of Pharmacology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Akinobu Togo
- Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Kei-ichiro Nakamura
- Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
| | - Akinori Nishi
- Department of Pharmacology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830–0011, Japan
- * E-mail:
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25
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Pasaoglu T, Schikorski T. Presynaptic size of associational/commissural CA3 synapses is controlled by fibroblast growth factor 22 in adult mice. Hippocampus 2015. [PMID: 26222899 DOI: 10.1002/hipo.22499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Associational/commissural CA3-CA3 synapses define the recurrent CA3 network that generates the input to CA1 pyramidal neurons. We quantified the fine structure of excitatory synapses in the stratum radiatum of the CA3d area in adult wild type (WT) and fibroblast growth factor 22 knock-out (FGF22KO) mice by using serial 3D electron microscopy. WT excitatory CA3 synapses are rather small yet range 10 fold in size. Spine size, however, was small and uniform and did not correlate with the size of the synaptic junction. To reveal mechanisms that regulate presynaptic structure, we investigated the role of FGF22, a target-derived signal specific for the distal part of area CA3 (CA3d). In adult FGF22KO mice, postsynaptic properties of associational CA3 synapses were unaltered. Presynaptically, the number of synaptic vesicles (SVs), the bouton volume, and the number of vesicles in axonal regions (the super pool) were reduced. This concurrent decrease suggests concerted control by FGF22 of presynaptic size. This hypothesis is supported by the finding that WT presynapses in the proximal part of area CA3 (CA3p) that do not receive FGF22 signaling in WT mice were smaller than presynapses in CA3d in WT but of comparable size in CA3d of FGF22KO mice. Docked SV density was decreased in CA1, CA3d, and CA3p in FGF22KO mice. Because CA1 and CA3p are not directly affected by the loss of FGF22, the smaller docked SV density may be an adaptation to activity changes in the CA3 network. Thus, docked SV density potentially is a long-term regulator for the synaptic release probability and/or the strength of short-term depression in vivo.
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Affiliation(s)
- Taliha Pasaoglu
- Department of Anatomy, Universidad Central Del Caribe, Bayamon, Puerto Rico
| | - Thomas Schikorski
- Department of Anatomy, Universidad Central Del Caribe, Bayamon, Puerto Rico
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26
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Choi SY, Han K, Cutforth T, Chung W, Park H, Lee D, Kim R, Kim MH, Choi Y, Shen K, Kim E. Mice lacking the synaptic adhesion molecule Neph2/Kirrel3 display moderate hyperactivity and defective novel object preference. Front Cell Neurosci 2015; 9:283. [PMID: 26283919 PMCID: PMC4517382 DOI: 10.3389/fncel.2015.00283] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/10/2015] [Indexed: 11/13/2022] Open
Abstract
Synaptic adhesion molecules regulate diverse aspects of neuronal synapse development, including synapse specificity, formation, and maturation. Neph2, also known as Kirrel3, is an immunoglobulin superfamily adhesion molecule implicated in intellectual disability, neurocognitive delay associated with Jacobsen syndrome, and autism spectrum disorders. We here report mice lacking Neph2 (Neph2(-/-) mice) display moderate hyperactivity in a familiar, but not novel, environment and defective novel object recognition with normal performances in Morris water maze spatial learning and memory, contextual fear conditioning and extinction, and pattern separation tests. These mice also show normal levels of anxiety-like behaviors, social interaction, and repetitive behaviors. At the synapse level, Neph2(-/-) dentate gyrus granule cells exhibit unaltered dendritic spine density and spontaneous excitatory synaptic transmission. These results suggest that Neph2 is important for normal locomotor activity and object recognition memory.
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Affiliation(s)
- Su-Yeon Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Kihoon Han
- Department of Neuroscience and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University Seoul, South Korea
| | - Tyler Cutforth
- Department of Neurology, Columbia University Medical Center New York, NY, USA
| | - Woosuk Chung
- Department of Biomedical Sciences, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Haram Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Dongsoo Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science Daejeon, South Korea
| | - Ryunhee Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Myeong-Heui Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Yeeun Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Kang Shen
- Department of Biology, Stanford University Stanford, CA, USA ; Howard Hughes Medical Institute Chevy Chase, MD, USA
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea ; Center for Synaptic Brain Dysfunctions, Institute for Basic Science Daejeon, South Korea
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27
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The ROR2 tyrosine kinase receptor regulates dendritic spine morphogenesis in hippocampal neurons. Mol Cell Neurosci 2015; 67:22-30. [DOI: 10.1016/j.mcn.2015.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 05/03/2015] [Accepted: 05/19/2015] [Indexed: 11/19/2022] Open
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Mosca TJ. On the Teneurin track: a new synaptic organization molecule emerges. Front Cell Neurosci 2015; 9:204. [PMID: 26074772 PMCID: PMC4444827 DOI: 10.3389/fncel.2015.00204] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/11/2015] [Indexed: 11/16/2022] Open
Abstract
To achieve proper synaptic development and function, coordinated signals must pass between the pre- and postsynaptic membranes. Such transsynaptic signals can be comprised of receptors and secreted ligands, membrane associated receptors, and also pairs of synaptic cell adhesion molecules. A critical open question bridging neuroscience, developmental biology, and cell biology involves identifying those signals and elucidating how they function. Recent work in Drosophila and vertebrate systems has implicated a family of proteins, the Teneurins, as a new transsynaptic signal in both the peripheral and central nervous systems. The Teneurins have established roles in neuronal wiring, but studies now show their involvement in regulating synaptic connections between neurons and bridging the synaptic membrane and the cytoskeleton. This review will examine the Teneurins as synaptic cell adhesion molecules, explore how they regulate synaptic organization, and consider how some consequences of human Teneurin mutations may have synaptopathic origins.
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Affiliation(s)
- Timothy J Mosca
- Department of Biology, Stanford University Stanford, CA, USA
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29
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Dabrowski A, Terauchi A, Strong C, Umemori H. Distinct sets of FGF receptors sculpt excitatory and inhibitory synaptogenesis. Development 2015; 142:1818-30. [PMID: 25926357 PMCID: PMC4440923 DOI: 10.1242/dev.115568] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 03/25/2015] [Indexed: 12/13/2022]
Abstract
Neurons in the brain must establish a balanced network of excitatory and inhibitory synapses during development for the brain to function properly. An imbalance between these synapses underlies various neurological and psychiatric disorders. The formation of excitatory and inhibitory synapses requires precise molecular control. In the hippocampus, the structure crucial for learning and memory, fibroblast growth factor 22 (FGF22) and FGF7 specifically promote excitatory or inhibitory synapse formation, respectively. Knockout of either Fgf gene leads to excitatory-inhibitory imbalance in the mouse hippocampus and manifests in an altered susceptibility to epileptic seizures, underscoring the importance of FGF-dependent synapse formation. However, the receptors and signaling mechanisms by which FGF22 and FGF7 induce excitatory and inhibitory synapse differentiation are unknown. Here, we show that distinct sets of overlapping FGF receptors (FGFRs), FGFR2b and FGFR1b, mediate excitatory or inhibitory presynaptic differentiation in response to FGF22 and FGF7. Excitatory presynaptic differentiation is impaired in Fgfr2b and Fgfr1b mutant mice; however, inhibitory presynaptic defects are only found in Fgfr2b mutants. FGFR2b and FGFR1b are required for an excitatory presynaptic response to FGF22, whereas only FGFR2b is required for an inhibitory presynaptic response to FGF7. We further find that FGFRs are required in the presynaptic neuron to respond to FGF22, and that FRS2 and PI3K, but not PLCγ, mediate FGF22-dependent presynaptic differentiation. Our results reveal the specific receptors and signaling pathways that mediate FGF-dependent presynaptic differentiation, and thereby provide a mechanistic understanding of precise excitatory and inhibitory synapse formation in the mammalian brain.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/physiology
- Cells, Cultured
- Fibroblast Growth Factors/genetics
- Fibroblast Growth Factors/metabolism
- Mice
- Mice, Knockout
- Neurogenesis/genetics
- Neurogenesis/physiology
- Neurons/cytology
- Neurons/metabolism
- Receptor, Fibroblast Growth Factor, Type 1/genetics
- Receptor, Fibroblast Growth Factor, Type 1/metabolism
- Receptor, Fibroblast Growth Factor, Type 2/genetics
- Receptor, Fibroblast Growth Factor, Type 2/metabolism
- Receptors, Fibroblast Growth Factor/genetics
- Receptors, Fibroblast Growth Factor/metabolism
- Synapses/metabolism
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Affiliation(s)
- Ania Dabrowski
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Akiko Terauchi
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Cameron Strong
- Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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30
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Cerpa W, Ramos-Fernández E, Inestrosa NC. Modulation of the NMDA Receptor Through Secreted Soluble Factors. Mol Neurobiol 2014; 53:299-309. [PMID: 25429903 DOI: 10.1007/s12035-014-9009-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 11/14/2014] [Indexed: 12/11/2022]
Abstract
Synaptic activity is a critical determinant in the formation and development of excitatory synapses in the central nervous system (CNS). The excitatory current is produced and regulated by several ionotropic receptors, including those that respond to glutamate. These channels are in turn regulated through several secreted factors that function as synaptic organizers. Specifically, Wnt, brain-derived neurotrophic factor (BDNF), fibroblast growth factor (FGF), and transforming growth factor (TGF) particularly regulate the N-methyl-D-aspartate receptor (NMDAR) glutamatergic channel. These factors likely regulate early embryonic development and directly control key proteins in the function of important glutamatergic channels. Here, we review the secreted molecules that participate in synaptic organization and discuss the cell signaling behind of this fine regulation. Additionally, we discuss how these factors are dysregulated in some neuropathologies associated with glutamatergic synaptic transmission in the CNS.
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Affiliation(s)
- Waldo Cerpa
- Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Eva Ramos-Fernández
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centre for Healthy Brain Ageing, School of Psychiatry, UNSW, Faculty of Medicine, University of New South Wales, Sydney, Australia.,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
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31
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Terauchi A, Timmons KM, Kikuma K, Pechmann Y, Kneussel M, Umemori H. Selective synaptic targeting of the excitatory and inhibitory presynaptic organizers FGF22 and FGF7. J Cell Sci 2014; 128:281-92. [PMID: 25431136 DOI: 10.1242/jcs.158337] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Specific formation of excitatory and inhibitory synapses is crucial for proper functioning of the brain. Fibroblast growth factor 22 (FGF22) and FGF7 are postsynaptic-cell-derived presynaptic organizers necessary for excitatory and inhibitory presynaptic differentiation, respectively, in the hippocampus. For the establishment of specific synaptic networks, these FGFs must localize to appropriate synaptic locations - FGF22 to excitatory and FGF7 to inhibitory postsynaptic sites. Here, we show that distinct motor and adaptor proteins contribute to intracellular microtubule transport of FGF22 and FGF7. Excitatory synaptic targeting of FGF22 requires the motor proteins KIF3A and KIF17 and the adaptor protein SAP102 (also known as DLG3). By contrast, inhibitory synaptic targeting of FGF7 requires the motor KIF5 and the adaptor gephyrin. Time-lapse imaging shows that FGF22 moves with SAP102, whereas FGF7 moves with gephyrin. These results reveal the basis of selective targeting of the excitatory and inhibitory presynaptic organizers that supports their different synaptogenic functions. Finally, we found that knockdown of SAP102 or PSD95 (also known as DLG4), which impairs the differentiation of excitatory synapses, alters FGF7 localization, suggesting that signals from excitatory synapses might regulate inhibitory synapse formation by controlling the distribution of the inhibitory presynaptic organizer.
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Affiliation(s)
- Akiko Terauchi
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Kendall M Timmons
- Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Koto Kikuma
- Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Yvonne Pechmann
- Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Falkenried 94, D-20251 Hamburg, Germany
| | - Matthias Kneussel
- Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Falkenried 94, D-20251 Hamburg, Germany
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Molecular & Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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32
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Williams AJ, Umemori H. The best-laid plans go oft awry: synaptogenic growth factor signaling in neuropsychiatric disease. Front Synaptic Neurosci 2014; 6:4. [PMID: 24672476 PMCID: PMC3957327 DOI: 10.3389/fnsyn.2014.00004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 02/21/2014] [Indexed: 12/27/2022] Open
Abstract
Growth factors play important roles in synapse formation. Mouse models of neuropsychiatric diseases suggest that defects in synaptogenic growth factors, their receptors, and signaling pathways can lead to disordered neural development and various behavioral phenotypes, including anxiety, memory problems, and social deficits. Genetic association studies in humans have found evidence for similar relationships between growth factor signaling pathways and neuropsychiatric phenotypes. Accumulating data suggest that dysfunction in neuronal circuitry, caused by defects in growth factor-mediated synapse formation, contributes to the susceptibility to multiple neuropsychiatric diseases, including epilepsy, autism, and disorders of thought and mood (e.g., schizophrenia and bipolar disorder, respectively). In this review, we will focus on how specific synaptogenic growth factors and their downstream signaling pathways might be involved in the development of neuropsychiatric diseases.
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Affiliation(s)
- Aislinn J Williams
- Department of Psychiatry, University of Michigan Ann Arbor, MI, USA ; Molecular and Behavioral Neuroscience Institute, University of Michigan Ann Arbor, MI, USA
| | - Hisashi Umemori
- Molecular and Behavioral Neuroscience Institute, University of Michigan Ann Arbor, MI, USA ; Department of Neurology, F.M. Kirby Neurobiology Center, Harvard Medical School, Boston Children's Hospital Boston, MA, USA
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33
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Lee H, Lee EJ, Song YS, Kim E. Long-term depression-inducing stimuli promote cleavage of the synaptic adhesion molecule NGL-3 through NMDA receptors, matrix metalloproteinases and presenilin/γ-secretase. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130158. [PMID: 24298159 PMCID: PMC3843889 DOI: 10.1098/rstb.2013.0158] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Long-term depression (LTD) reduces the functional strength of excitatory synapses through mechanisms that include the removal of AMPA glutamate receptors from the postsynaptic membrane. LTD induction is also known to result in structural changes at excitatory synapses, including the shrinkage of dendritic spines. Synaptic adhesion molecules are thought to contribute to the development, function and plasticity of neuronal synapses largely through their trans-synaptic adhesions. However, little is known about how synaptic adhesion molecules are altered during LTD. We report here that NGL-3 (netrin-G ligand-3), a postsynaptic adhesion molecule that trans-synaptically interacts with the LAR family of receptor tyrosine phosphatases and intracellularly with the postsynaptic scaffolding protein PSD-95, undergoes a proteolytic cleavage process. NGL-3 cleavage is induced by NMDA treatment in cultured neurons and low-frequency stimulation in brain slices and requires the activities of NMDA glutamate receptors, matrix metalloproteinases (MMPs) and presenilin/γ-secretase. These results suggest that NGL-3 is a novel substrate of MMPs and γ-secretase and that NGL-3 cleavage may regulate synaptic adhesion during LTD.
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Affiliation(s)
- Hyejin Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), , Daejeon 305-701, Korea
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34
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Kudryashova IV. Analysis of conditions that are important for the beginning of consolidation in a model of long-term synaptic potentiation. NEUROCHEM J+ 2013. [DOI: 10.1134/s1819712413030070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Woo J, Kwon SK, Nam J, Choi S, Takahashi H, Krueger D, Park J, Lee Y, Bae JY, Lee D, Ko J, Kim H, Kim MH, Bae YC, Chang S, Craig AM, Kim E. The adhesion protein IgSF9b is coupled to neuroligin 2 via S-SCAM to promote inhibitory synapse development. ACTA ACUST UNITED AC 2013; 201:929-44. [PMID: 23751499 PMCID: PMC3678166 DOI: 10.1083/jcb.201209132] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Synaptic adhesion molecules regulate diverse aspects of synapse formation and maintenance. Many known synaptic adhesion molecules localize at excitatory synapses, whereas relatively little is known about inhibitory synaptic adhesion molecules. Here we report that IgSF9b is a novel, brain-specific, homophilic adhesion molecule that is strongly expressed in GABAergic interneurons. IgSF9b was preferentially localized at inhibitory synapses in cultured rat hippocampal and cortical interneurons and was required for the development of inhibitory synapses onto interneurons. IgSF9b formed a subsynaptic domain distinct from the GABAA receptor- and gephyrin-containing domain, as indicated by super-resolution imaging. IgSF9b was linked to neuroligin 2, an inhibitory synaptic adhesion molecule coupled to gephyrin, via the multi-PDZ protein S-SCAM. IgSF9b and neuroligin 2 could reciprocally cluster each other. These results suggest a novel mode of inhibitory synaptic organization in which two subsynaptic domains, one containing IgSF9b for synaptic adhesion and the other containing gephyrin and GABAA receptors for synaptic transmission, are interconnected through S-SCAM and neuroligin 2.
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Affiliation(s)
- Jooyeon Woo
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon 305-701, South Korea
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36
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Abstract
Semaphorins are key players in the control of neural circuit development. Recent studies have uncovered several exciting and novel aspects of neuronal semaphorin signalling in various cellular processes--including neuronal polarization, topographical mapping and axon sorting--that are crucial for the assembly of functional neuronal connections. This progress is important for further understanding the many neuronal and non-neuronal functions of semaphorins and for gaining insight into their emerging roles in the perturbed neural connectivity that is observed in some diseases. This Review discusses recent advances in semaphorin research, focusing on novel aspects of neuronal semaphorin receptor regulation and previously unexplored cellular functions of semaphorins in the nervous system.
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37
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Terauchi A, Umemori H. Specific sets of intrinsic and extrinsic factors drive excitatory and inhibitory circuit formation. Neuroscientist 2012; 18:271-86. [PMID: 21652588 PMCID: PMC4140556 DOI: 10.1177/1073858411404228] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
How are excitatory (glutamatergic) and inhibitory (GABAergic) synapses established? Do distinct molecular mechanisms direct differentiation of glutamatergic and GABAergic synapses? In the brain, glutamatergic and GABAergic synaptic connections are formed with specific patterns. To establish such precise synaptic patterns, neurons pass through multiple checkpoints during development, such as cell fate determination, cell migration and localization, axonal guidance and target recognition, and synapse formation. Each stage offers key molecules for neurons/synapses to obtain glutamatergic or GABAergic specificity. Some mechanisms are based on intrinsic systems to induce gene expression, whereas others are based on extrinsic systems mediated by cell-cell or axon-target interactions. Recent studies indicate that specific formation of glutamatergic and GABAergic synapses is controlled by the expression or activation of different sets of molecules during development. In this review, the authors outline stages critical to the determination of glutamatergic or GABAergic specificity and describe molecules that act as determinants of specificities in each stage, with a particular focus on the synapse formation stage. They also discuss possible mechanisms underlying glutamatergic and GABAergic synapse formation via synapse-type specific synaptic organizers.
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Affiliation(s)
- Akiko Terauchi
- Molecular & Behavioral Neuroscience Institute, University
of Michigan Medical School, Ann Arbor, MI 48109-2200
| | - Hisashi Umemori
- Molecular & Behavioral Neuroscience Institute, University
of Michigan Medical School, Ann Arbor, MI 48109-2200
- Departments of Biological Chemistry, University of Michigan
Medical School, Ann Arbor, MI 48109-2200
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Chen C, Li PP, Madhavan R, Peng HB. The function of p120 catenin in filopodial growth and synaptic vesicle clustering in neurons. Mol Biol Cell 2012; 23:2680-91. [PMID: 22648172 PMCID: PMC3395657 DOI: 10.1091/mbc.e12-01-0004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The signaling by p120 catenin via its downstream effector RhoA is essential for filopodial growth and synaptic vesicle clustering along spinal axons and contributes to the formation of the neuromuscular junction. At the developing neuromuscular junction (NMJ), physical contact between motor axons and muscle cells initiates presynaptic and postsynaptic differentiation. Using Xenopus nerve–muscle cocultures, we previously showed that innervating axons induced muscle filopodia (myopodia), which facilitated interactions between the synaptic partners and promoted NMJ formation. The myopodia were generated by nerve-released signals through muscle p120 catenin (p120ctn), a protein of the cadherin complex that modulates the activity of Rho GTPases. Because axons also extend filopodia that mediate early nerve–muscle interactions, here we test p120ctn's function in the assembly of these presynaptic processes. Overexpression of wild-type p120ctn in Xenopus spinal neurons leads to an increase in filopodial growth and synaptic vesicle (SV) clustering along axons, whereas the development of these specializations is inhibited following the expression of a p120ctn mutant lacking sequences important for regulating Rho GTPases. The p120ctn mutant also inhibits the induction of axonal filopodia and SV clusters by basic fibroblast growth factor, a muscle-derived molecule that triggers presynaptic differentiation. Of importance, introduction of the p120ctn mutant into neurons hinders NMJ formation, which is observed as a reduction in the accumulation of acetylcholine receptors at innervation sites in muscle. Our results suggest that p120ctn signaling in motor neurons promotes nerve–muscle interaction and NMJ assembly.
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Affiliation(s)
- Cheng Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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39
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Singh R, Su J, Brooks J, Terauchi A, Umemori H, Fox MA. Fibroblast growth factor 22 contributes to the development of retinal nerve terminals in the dorsal lateral geniculate nucleus. Front Mol Neurosci 2012; 4:61. [PMID: 22363257 PMCID: PMC3306139 DOI: 10.3389/fnmol.2011.00061] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 12/23/2011] [Indexed: 11/28/2022] Open
Abstract
At least three forms of signaling between pre- and postsynaptic partners are necessary during synapse formation. First, “targeting” signals instruct presynaptic axons to recognize and adhere to the correct portion of a postsynaptic target cell. Second, trans-synaptic “organizing” signals induce differentiation in their synaptic partner so that each side of the synapse is specialized for synaptic transmission. Finally, in many regions of the nervous system an excess of synapses are initially formed, therefore “refinement” signals must either stabilize or destabilize the synapse to reinforce or eliminate connections, respectively. Because of both their importance in processing visual information and their accessibility, retinogeniculate synapses have served as a model for studying synaptic development. Molecular signals that drive retinogeniculate “targeting” and “refinement” have been identified, however, little is known about what “organizing” cues are necessary for the differentiation of retinal axons into presynaptic terminals. To identify such “organizing” cues, we used microarray analysis to assess whether any target-derived “synaptic organizers” were enriched in the mouse dorsal lateral geniculate nucleus (dLGN) during retinogeniculate synapse formation. One candidate “organizing” molecule enriched in perinatal dLGN was FGF22, a secreted cue that induces the formation of excitatory nerve terminals in muscle, hippocampus, and cerebellum. In FGF22 knockout mice, the development of retinal terminals in dLGN was impaired. Thus, FGF22 is an important “organizing” cue for the timely development of retinogeniculate synapses.
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Affiliation(s)
- Rishabh Singh
- Department of Anatomy and Neurobiology, Virginia Commonwealth University Medical Center Richmond, VA, USA
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Ding JB, Oh WJ, Sabatini BL, Gu C. Semaphorin 3E-Plexin-D1 signaling controls pathway-specific synapse formation in the striatum. Nat Neurosci 2011; 15:215-23. [PMID: 22179111 PMCID: PMC3267860 DOI: 10.1038/nn.3003] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 11/08/2011] [Indexed: 02/08/2023]
Abstract
The proper formation of synaptic connectivity in the mammalian brain is critical for complex behavior. In the striatum, balanced excitatory synaptic transmission from multiple sources onto two classes of principal neurons is required for coordinated and voluntary motor control. Here we show that the interaction between the secreted semaphorin 3E (Sema3E) and its receptor Plexin-D1 is a critical determinant of synaptic specificity in cortico-thalamo-striatal circuits in mice. We find that sema3E is highly expressed in thalamostriatal projection neurons whereas, in the striatum, plexin-D1 is selectively expressed in direct pathway medium spiny neurons (MSNs). Despite physical intermingling of the MSNs, genetic ablation of plexin-D1 or sema3E results in functional and anatomical rearrangement of thalamostriatal synapses specifically in direct pathway MSNs without effects on corticostriatal synapses. Thus, our results demonstrate that Sema3E and Plexin-D1 specify the degree of glutamatergic connectivity between a specific source and target within the complex circuitry of the basal ganglia.
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Affiliation(s)
- Jun B Ding
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
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41
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Kudryashova IV. Structural and functional modifications of presynaptic afferents: Do they correlate with learning mechanisms? NEUROCHEM J+ 2011. [DOI: 10.1134/s181971241104009x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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42
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Dabrowski A, Umemori H. Orchestrating the synaptic network by tyrosine phosphorylation signalling. J Biochem 2011; 149:641-53. [PMID: 21508038 PMCID: PMC3143439 DOI: 10.1093/jb/mvr047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Accepted: 04/08/2011] [Indexed: 01/07/2023] Open
Abstract
The establishment of a functional brain requires coordinated and stereotyped formation of synapses between neurons. For this, trans-synaptic molecular cues (synaptic organizers) are exchanged between a neuron and its target to organize appropriate synapses. The understanding of signalling mechanisms by which such synaptic organizers lead to synapse formation is just being elucidated. However, recent studies revealed that some of these cues act through receptor protein tyrosine kinases (RPTKs) or phosphatases (RPTPs). Synaptogenic RPTKs and RPTPs pattern synaptic network through affecting local protein-protein binding dynamics, changing the phosphorylation state of signalling cascades, or promoting gene expression. Each RPTK or RPTP has distinct roles in synapse formation, serving at different synapses or showing differential synaptogenic effects. Thus, tyrosine phosphorylation signalling plays critical roles in building the orchestrated synaptic circuitry in the brain.
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Affiliation(s)
- Ania Dabrowski
- Molecular & Behavioral Neuroscience Institute, Medical Scientist Training Program, Neuroscience Graduate Program and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
| | - Hisashi Umemori
- Molecular & Behavioral Neuroscience Institute, Medical Scientist Training Program, Neuroscience Graduate Program and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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43
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Yuzaki M. Cbln1 and its family proteins in synapse formation and maintenance. Curr Opin Neurobiol 2011; 21:215-20. [DOI: 10.1016/j.conb.2011.01.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 01/29/2011] [Accepted: 01/31/2011] [Indexed: 01/27/2023]
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44
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Matsuda K, Yuzaki M. Cbln family proteins promote synapse formation by regulating distinct neurexin signaling pathways in various brain regions. Eur J Neurosci 2011; 33:1447-61. [PMID: 21410790 DOI: 10.1111/j.1460-9568.2011.07638.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cbln1 (a.k.a. precerebellin) is a unique bidirectional synaptic organizer that plays an essential role in the formation and maintenance of excitatory synapses between granule cells and Purkinje cells in the mouse cerebellum. Cbln1 secreted from cerebellar granule cells directly induces presynaptic differentiation and indirectly serves as a postsynaptic organizer by binding to its receptor, the δ2 glutamate receptor. However, it remains unclear how Cbln1 binds to the presynaptic sites and interacts with other synaptic organizers. Furthermore, although Cbln1 and its family members Cbln2 and Cbln4 are expressed in brain regions other than the cerebellum, it is unknown whether they regulate synapse formation in these brain regions. In this study, we showed that Cbln1 and Cbln2, but not Cbln4, specifically bound to its presynaptic receptor -α and β isoforms of neurexin carrying the splice site 4 insert [NRXs(S4+)] - and induced synaptogenesis in cerebellar, hippocampal and cortical neurons in vitro. Cbln1 competed with synaptogenesis mediated by neuroligin 1, which lacks the splice sites A and B, but not leucine-rich repeat transmembrane protein 2, possibly by sharing the presynaptic receptor NRXs(S4+). However, unlike neurexins/neuroligins or neurexins/leucine-rich repeat transmembrane proteins, the interaction between NRX1β(S4+) and Cbln1 was insensitive to extracellular Ca(2+) concentrations. These findings revealed the unique and general roles of Cbln family proteins in mediating the formation and maintenance of synapses not only in the cerebellum but also in various other brain regions.
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Affiliation(s)
- Keiko Matsuda
- Department of Physiology, Keio University, Shinanomachi, Shinjuku-ku, Tokyo, Japan
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Wingless-type family member 5A (Wnt-5a) stimulates synaptic differentiation and function of glutamatergic synapses. Proc Natl Acad Sci U S A 2010; 107:21164-9. [PMID: 21084636 DOI: 10.1073/pnas.1010011107] [Citation(s) in RCA: 163] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Growing evidence indicates that Wingless-type (Wnt) signaling plays an important role in the maturation of the central nervous system. We report here that Wingless-type family member 5A (Wnt-5a) is expressed early in development and stimulates dendrite spine morphogenesis, inducing de novo formation of spines and increasing the size of the preexisting ones in hippocampal neurons. Wnt-5a increased intracellular calcium concentration in dendritic processes and the amplitude of NMDA spontaneous miniature currents. Acute application of Wnt-5a increased the amplitude of field excitatory postsynaptic potentials (fEPSP) in hippocampal slices, an effect that was prevented by calcium-channel blockers. The physiological relevance of our findings is supported by studies showing that Wnt scavengers decreased spine density, miniature excitatory postsynaptic currents, and fEPSP amplitude. We conclude that Wnt-5a stimulates different aspects of synaptic differentiation and plasticity in the mammalian central nervous system.
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Yuzaki M. Synapse formation and maintenance by C1q family proteins: a new class of secreted synapse organizers. Eur J Neurosci 2010; 32:191-7. [PMID: 20646056 DOI: 10.1111/j.1460-9568.2010.07346.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Several C1q family members, especially the Cbln and C1q-like subfamilies, are highly and predominantly expressed in the central nervous system. Cbln1, a member of the Cbln subfamily, plays two unique roles at parallel fiber (PF)-Purkinje cell synapses in the cerebellum: the formation and stabilization of synaptic contact, and the control of functional synaptic plasticity by regulating the postsynaptic endocytotic pathway. The delta2 glutamate receptor (GluD2), which is predominantly expressed in Purkinje cells, plays similar critical roles in the cerebellum. In addition, viral expression of GluD2 or the application of recombinant Cbln1 induces PF-Purkinje cell synaptogenesis in vitro and in vivo. Antigen-unmasking methods were necessary to reveal the immunoreactivities for endogenous Cbln1 and GluD2 at the synaptic junction of PF synapses. We propose that Cbln1 and GluD2 are located at the synaptic cleft, where various proteins undergo intricate molecular interactions with each other, and serve as a bidirectional synaptic organizer.
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Affiliation(s)
- Michisuke Yuzaki
- Department of Physiology, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
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