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Heinze A, Schuldt C, Khudayberdiev S, van Bommel B, Hacker D, Schulz TG, Stringhi R, Marcello E, Mikhaylova M, Rust MB. Functional interdependence of the actin regulators CAP1 and cofilin1 in control of dendritic spine morphology. Cell Mol Life Sci 2022; 79:558. [PMID: 36264429 PMCID: PMC9585016 DOI: 10.1007/s00018-022-04593-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/06/2022] [Accepted: 10/07/2022] [Indexed: 12/01/2022]
Abstract
The vast majority of excitatory synapses are formed on small dendritic protrusions termed dendritic spines. Dendritic spines vary in size and density that are crucial determinants of excitatory synaptic transmission. Aberrations in spine morphogenesis can compromise brain function and have been associated with neuropsychiatric disorders. Actin filaments (F-actin) are the major structural component of dendritic spines, and therefore, actin-binding proteins (ABP) that control F-actin dis-/assembly moved into the focus as critical regulators of brain function. Studies of the past decade identified the ABP cofilin1 as a key regulator of spine morphology, synaptic transmission, and behavior, and they emphasized the necessity for a tight control of cofilin1 to ensure proper brain function. Here, we report spine enrichment of cyclase-associated protein 1 (CAP1), a conserved multidomain protein with largely unknown physiological functions. Super-resolution microscopy and live cell imaging of CAP1-deficient hippocampal neurons revealed impaired synaptic F-actin organization and dynamics associated with alterations in spine morphology. Mechanistically, we found that CAP1 cooperates with cofilin1 in spines and that its helical folded domain is relevant for this interaction. Moreover, our data proved functional interdependence of CAP1 and cofilin1 in control of spine morphology. In summary, we identified CAP1 as a novel regulator of the postsynaptic actin cytoskeleton that is essential for synaptic cofilin1 activity.
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Affiliation(s)
- Anika Heinze
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany
| | - Cara Schuldt
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany
| | - Sharof Khudayberdiev
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany
| | - Bas van Bommel
- AG Optobiology, Institute of Biology, Humboldt-University, 10115, Berlin, Germany
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
| | - Daniela Hacker
- AG Optobiology, Institute of Biology, Humboldt-University, 10115, Berlin, Germany
- Guest Group 'Neuronal Protein Transport', Institute for Molecular Neurogenetics, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20251, Hamburg, Germany
| | - Toni G Schulz
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Ramona Stringhi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133, Milan, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133, Milan, Italy
| | - Marina Mikhaylova
- AG Optobiology, Institute of Biology, Humboldt-University, 10115, Berlin, Germany
- Guest Group 'Neuronal Protein Transport', Institute for Molecular Neurogenetics, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20251, Hamburg, Germany
| | - Marco B Rust
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany.
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany.
- DFG Research Training Group 'Membrane Plasticity in Tissue Development and Remodeling', GRK 2213, Philipps-University of Marburg, 35032, Marburg, Germany.
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2
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Lee HN, Hyeon SJ, Kim H, Sim KM, Kim Y, Ju J, Lee J, Wang Y, Ryu H, Seong J. Decreased FAK activity and focal adhesion dynamics impair proper neurite formation of medium spiny neurons in Huntington's disease. Acta Neuropathol 2022; 144:521-536. [PMID: 35857122 DOI: 10.1007/s00401-022-02462-z] [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: 03/25/2022] [Revised: 06/11/2022] [Accepted: 06/25/2022] [Indexed: 11/29/2022]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a polyglutamine expansion in the protein huntingtin (HTT) [55]. While the final pathological consequence of HD is the neuronal cell death in the striatum region of the brain, it is still unclear how mutant HTT (mHTT) causes synaptic dysfunctions at the early stage and during the progression of HD. Here, we discovered that the basal activity of focal adhesion kinase (FAK) is severely reduced in a striatal HD cell line, a mouse model of HD, and the human post-mortem brains of HD patients. In addition, we observed with a FRET-based FAK biosensor [59] that neurotransmitter-induced FAK activation is decreased in HD striatal neurons. Total internal reflection fluorescence (TIRF) imaging revealed that the reduced FAK activity causes the impairment of focal adhesion (FA) dynamics, which further leads to the defect in filopodial dynamics causing the abnormally increased number of immature neurites in HD striatal neurons. Therefore, our results suggest that the decreased FAK and FA dynamics in HD impair the proper formation of neurites, which is crucial for normal synaptic functions [52]. We further investigated the molecular mechanism of FAK inhibition in HD and surprisingly discovered that mHTT strongly associates with phosphatidylinositol 4,5-biphosphate, altering its normal distribution at the plasma membrane, which is crucial for FAK activation [14, 60]. Therefore, our results provide a novel molecular mechanism of FAK inhibition in HD along with its pathological mechanism for synaptic dysfunctions during the progression of HD.
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Affiliation(s)
- Hae Nim Lee
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, 02453, Republic of Korea
| | - Seung Jae Hyeon
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Heejung Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, 02453, Republic of Korea
| | - Kyoung Mi Sim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Yunha Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jeongmin Ju
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Junghee Lee
- Department of Neurology, Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Yingxiao Wang
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Hoon Ryu
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
| | - Jihye Seong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
- Department of Converging Science and Technology, Kyung Hee University, Seoul, 02453, Republic of Korea.
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea.
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3
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Banerjee SL, Lessard F, Chartier FJM, Jacquet K, Osornio-Hernandez AI, Teyssier V, Ghani K, Lavoie N, Lavoie JN, Caruso M, Laprise P, Elowe S, Lambert JP, Bisson N. EPH receptor tyrosine kinases phosphorylate the PAR-3 scaffold protein to modulate downstream signaling networks. Cell Rep 2022; 40:111031. [PMID: 35793621 DOI: 10.1016/j.celrep.2022.111031] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 04/26/2022] [Accepted: 06/13/2022] [Indexed: 11/03/2022] Open
Abstract
EPH receptors (EPHRs) constitute the largest family among receptor tyrosine kinases in humans. They are mainly involved in short-range cell-cell communication events that regulate cell adhesion, migration, and boundary formation. However, the molecular mechanisms by which EPHRs control these processes are less understood. To address this, we unravel EPHR-associated complexes under native conditions using mass-spectrometry-based BioID proximity labeling. We obtain a composite proximity network from EPHA4, -B2, -B3, and -B4 that comprises 395 proteins, most of which were not previously linked to EPHRs. We examine the contribution of several BioID-identified candidates via loss-of-function in an EPHR-dependent cell-segregation assay. We find that the signaling scaffold PAR-3 is required for cell sorting and that EPHRs directly phosphorylate PAR-3. We also delineate a signaling complex involving the C-terminal SRC kinase (CSK), whose recruitment to PAR-3 is dependent on EPHR signals. Our work describes signaling networks by which EPHRs regulate cellular phenotypes.
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Affiliation(s)
- Sara L Banerjee
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Frédéric Lessard
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - François J M Chartier
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Kévin Jacquet
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada
| | - Ana I Osornio-Hernandez
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Valentine Teyssier
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Karim Ghani
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada
| | - Noémie Lavoie
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada
| | - Josée N Lavoie
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Québec, QC, Canada
| | - Manuel Caruso
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Québec, QC, Canada
| | - Patrick Laprise
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Québec, QC, Canada
| | - Sabine Elowe
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Department of Pediatrics, Université Laval, Québec, QC, Canada
| | - Jean-Philippe Lambert
- Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; Department of Molecular Medicine, Université Laval, Québec, QC, Canada; Centre de recherche en données massives de l'Université Laval, Québec, QC, Canada; Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Endocrinologie-néphrologie, Québec, QC, Canada
| | - Nicolas Bisson
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Quebec-Université Laval, Division Oncologie, Québec, QC, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, QC, Canada; PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Québec, QC, Canada.
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Prospéri MT, Pernier J, Lachuer H, Coudrier E. Plekhh1, a partner of myosin 1 and an effector of EphB2 controls the cortical actin network for cell repulsion. J Cell Sci 2021; 134:272686. [PMID: 34723325 DOI: 10.1242/jcs.258802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 10/26/2021] [Indexed: 11/20/2022] Open
Abstract
EphB2/ephrinB signalling that plays a major role in cell segregation during embryonic development and tissue homeostasis, induces an important reorganization of the cortical actin network. We have previously reported that myosin 1b contributes to the reorganisation of the cortical actin network upon EphB2 signalling. In this report we have identified Plekhh1, as a new partner of members of the myosin 1 family and EphB2 receptors. Plekhh1 interacts with myosin 1b via its N-terminus domain and with EphB2 via its C-terminus domain. Furthermore, Plekhh1 is tyrosine-phosphorylated, and this depends on EphB2 kinase activity. Such as the manipulation of the expression level of myosin 1b and myosin 1c, manipulation of Plekhh1 expression levels reveals that Plekhh1 controls the formation of filopodia, the length of focal adhesions and the formation of blebs. Furthermore, binding of Plekhh1 interacting domain to myosin 1b increases the motor activity of myosin 1b in vitro. Together our data show that Plekhh1 is an effector of EphB2 and suggest that Plekhh1 regulates the cortical actin network via the interaction of its N-terminus domain with myosin 1 upon EphB2/ephrinB signalling.
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Affiliation(s)
- Marie-Thérèse Prospéri
- Institut Curie, PSL Research University and C.N.R.S. UMR 144, 26 rue d'Ulm, Paris, France.,Sorbonne Université, 75005 Paris, France
| | - Julien Pernier
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005 Paris, France
| | - Hugo Lachuer
- Institut Curie, PSL Research University and C.N.R.S. UMR 144, 26 rue d'Ulm, Paris, France.,Sorbonne Université, 75005 Paris, France
| | - Evelyne Coudrier
- Institut Curie, PSL Research University and C.N.R.S. UMR 144, 26 rue d'Ulm, Paris, France.,Sorbonne Université, 75005 Paris, France
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5
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Bodin R, Paillé V, Oullier T, Durand T, Aubert P, Le Berre-Scoul C, Hulin P, Neunlist M, Cissé M. The ephrin receptor EphB2 regulates the connectivity and activity of enteric neurons. J Biol Chem 2021; 297:101300. [PMID: 34648765 PMCID: PMC8569587 DOI: 10.1016/j.jbc.2021.101300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 10/01/2021] [Accepted: 10/08/2021] [Indexed: 11/29/2022] Open
Abstract
Highly organized circuits of enteric neurons are required for the regulation of gastrointestinal functions, such as peristaltism or migrating motor complex. However, the factors and molecular mechanisms that regulate the connectivity of enteric neurons and their assembly into functional neuronal networks are largely unknown. A better understanding of the mechanisms by which neurotrophic factors regulate this enteric neuron circuitry is paramount to understanding enteric nervous system (ENS) physiology. EphB2, a receptor tyrosine kinase, is essential for neuronal connectivity and plasticity in the brain, but so far its presence and function in the ENS remain largely unexplored. Here we report that EphB2 is expressed preferentially by enteric neurons relative to glial cells throughout the gut in rats. We show that in primary enteric neurons, activation of EphB2 by its natural ligand ephrinB2 engages ERK signaling pathways. Long-term activation with ephrinB2 decreases EphB2 expression and reduces molecular and functional connectivity in enteric neurons without affecting neuronal density, ganglionic fiber bundles, or overall neuronal morphology. This is highlighted by a loss of neuronal plasticity markers such as synapsin I, PSD95, and synaptophysin, and a decrease of spontaneous miniature synaptic currents. Together, these data identify a critical role for EphB2 in the ENS and reveal a unique EphB2-mediated molecular program of synapse regulation in enteric neurons.
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Affiliation(s)
- Raphael Bodin
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Vincent Paillé
- UMR 1280 Physiologie des Adaptations Nutritionnelles, INRA, Institut des Maladies de l'Appareil Digestif, Université de Nantes, Nantes, France
| | - Thibauld Oullier
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Tony Durand
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Philippe Aubert
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Catherine Le Berre-Scoul
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | | | - Michel Neunlist
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France
| | - Moustapha Cissé
- Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Université de Nantes, Nantes, France.
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LIM-Kinases in Synaptic Plasticity, Memory, and Brain Diseases. Cells 2021; 10:cells10082079. [PMID: 34440848 PMCID: PMC8391678 DOI: 10.3390/cells10082079] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/12/2022] Open
Abstract
Learning and memory require structural and functional modifications of synaptic connections, and synaptic deficits are believed to underlie many brain disorders. The LIM-domain-containing protein kinases (LIMK1 and LIMK2) are key regulators of the actin cytoskeleton by affecting the actin-binding protein, cofilin. In addition, LIMK1 is implicated in the regulation of gene expression by interacting with the cAMP-response element-binding protein. Accumulating evidence indicates that LIMKs are critically involved in brain function and dysfunction. In this paper, we will review studies on the roles and underlying mechanisms of LIMKs in the regulation of long-term potentiation (LTP) and depression (LTD), the most extensively studied forms of long-lasting synaptic plasticity widely regarded as cellular mechanisms underlying learning and memory. We will also discuss the involvement of LIMKs in the regulation of the dendritic spine, the structural basis of synaptic plasticity, and memory formation. Finally, we will discuss recent progress on investigations of LIMKs in neurological and mental disorders, including Alzheimer’s, Parkinson’s, Williams–Beuren syndrome, schizophrenia, and autism spectrum disorders.
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Paxillin Is Required for Proper Spinal Motor Axon Growth into the Limb. J Neurosci 2021; 41:3808-3821. [PMID: 33727334 DOI: 10.1523/jneurosci.2863-20.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 03/04/2021] [Accepted: 03/07/2021] [Indexed: 11/21/2022] Open
Abstract
To assemble the functional circuits of the nervous system, the neuronal axonal growth cones must be precisely guided to their proper targets, which can be achieved through cell-surface guidance receptor activation by ligand binding in the periphery. We investigated the function of paxillin, a focal adhesion protein, as an essential growth cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show paxillin expression in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb. Paxillin loss-of-function and gain-of-function using in ovo electroporation in chick LMC neurons, of either sex, perturbed LMC axon trajectory selection, demonstrating an essential role of paxillin in motor axon guidance. In addition, a neuron-specific paxillin deletion in mice led to LMC axon trajectory selection errors. We also show that knocking down paxillin attenuates the growth preference of LMC neurites against ephrins in vitro, and erythropoietin-producing human hepatocellular (Eph)-mediated retargeting of LMC axons in vivo, suggesting paxillin involvement in Eph-mediated LMC motor axon guidance. Finally, both paxillin knockdown and ectopic expression of a nonphosphorylable paxillin mutant attenuated the retargeting of LMC axons caused by Src overexpression, implicating paxillin as a Src target in Eph signal relay in this context. In summary, our findings demonstrate that paxillin is required for motor axon guidance and suggest its essential role in the ephrin-Eph signaling pathway resulting in motor axon trajectory selection.SIGNIFICANCE STATEMENT During the development of neural circuits, precise connections need to be established among neurons or between neurons and their muscle targets. A protein family found in neurons, Eph, is essential at different stages of neural circuit formation, including nerve outgrowth and pathfinding, and is proposed to mediate the onset and progression of several neurodegenerative diseases, such as Alzheimer's disease. To investigate how Ephs relay their signals to mediate nerve growth, we investigated the function of a molecule called paxillin and found it important for the development of spinal nerve growth toward their muscle targets, suggesting its role as an effector of Eph signals. Our work could thus provide new information on how neuromuscular connectivity is properly established during embryonic development.
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MMP-9 Signaling Pathways That Engage Rho GTPases in Brain Plasticity. Cells 2021; 10:cells10010166. [PMID: 33467671 PMCID: PMC7830260 DOI: 10.3390/cells10010166] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 02/08/2023] Open
Abstract
The extracellular matrix (ECM) has been identified as a critical factor affecting synaptic function. It forms a functional scaffold that provides both the structural support and the reservoir of signaling molecules necessary for communication between cellular constituents of the central nervous system (CNS). Among numerous ECM components and modifiers that play a role in the physiological and pathological synaptic plasticity, matrix metalloproteinase 9 (MMP-9) has recently emerged as a key molecule. MMP-9 may contribute to the dynamic remodeling of structural and functional plasticity by cleaving ECM components and cell adhesion molecules. Notably, MMP-9 signaling was shown to be indispensable for long-term memory formation that requires synaptic remodeling. The core regulators of the dynamic reorganization of the actin cytoskeleton and cell adhesion are the Rho family of GTPases. These proteins have been implicated in the control of a wide range of cellular processes occurring in brain physiology and pathology. Here, we discuss the contribution of Rho GTPases to MMP-9-dependent signaling pathways in the brain. We also describe how the regulation of Rho GTPases by post-translational modifications (PTMs) can influence these processes.
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9
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Astrocytic Ephrin-B1 Controls Excitatory-Inhibitory Balance in Developing Hippocampus. J Neurosci 2020; 40:6854-6871. [PMID: 32801156 DOI: 10.1523/jneurosci.0413-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/08/2020] [Accepted: 07/20/2020] [Indexed: 12/12/2022] Open
Abstract
Astrocytes are implicated in synapse formation and elimination, which are associated with developmental refinements of neuronal circuits. Astrocyte dysfunctions are also linked to synapse pathologies associated with neurodevelopmental disorders and neurodegenerative diseases. Although several astrocyte-derived secreted factors are implicated in synaptogenesis, the role of contact-mediated glial-neuronal interactions in synapse formation and elimination during development is still unknown. In this study, we examined whether the loss or overexpression of the membrane-bound ephrin-B1 in astrocytes during postnatal day (P) 14-28 period would affect synapse formation and maturation in the developing hippocampus. We found enhanced excitation of CA1 pyramidal neurons in astrocyte-specific ephrin-B1 KO male mice, which coincided with a greater vGlut1/PSD95 colocalization, higher dendritic spine density, and enhanced evoked AMPAR and NMDAR EPSCs. In contrast, EPSCs were reduced in CA1 neurons neighboring ephrin-B1-overexpressing astrocytes. Overexpression of ephrin-B1 in astrocytes during P14-28 developmental period also facilitated evoked IPSCs in CA1 neurons, while evoked IPSCs and miniature IPSC amplitude were reduced following astrocytic ephrin-B1 loss. Lower numbers of parvalbumin-expressing cells and a reduction in the inhibitory VGAT/gephyrin-positive synaptic sites on CA1 neurons in the stratum pyramidale and stratum oriens layers of KO hippocampus may contribute to reduced inhibition and higher excitation. Finally, dysregulation of excitatory/inhibitory balance in KO male mice is most likely responsible for impaired sociability observed in these mice. The ability of astrocytic ephrin-B1 to influence both excitatory and inhibitory synapses during development can potentially contribute to developmental refinement of neuronal circuits.SIGNIFICANCE STATEMENT This report establishes a link between astrocytes and the development of excitatory and inhibitory balance in the mouse hippocampus during early postnatal development. We provide new evidence that astrocytic ephrin-B1 differentially regulates development of excitatory and inhibitory circuits in the hippocampus during early postnatal development using a multidisciplinary approach. The ability of astrocytic ephrin-B1 to influence both excitatory and inhibitory synapses during development can potentially contribute to developmental refinement of neuronal circuits and associated behaviors. Given widespread and growing interest in the astrocyte-mediated mechanisms that regulate synapse development, and the role of EphB receptors in neurodevelopmental disorders, these findings establish a foundation for future studies of astrocytes in clinically relevant conditions.
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Activation of EphB receptors contributes to primary sensory neuron excitability by facilitating Ca2+ influx directly or through Src kinase-mediated N-methyl-D-aspartate receptor phosphorylation. Pain 2020; 161:1584-1596. [DOI: 10.1097/j.pain.0000000000001855] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Uzair ID, Flamini MI, Sanchez AM. Rapid Estrogen and Progesterone Signaling to Dendritic Spine Formation via Cortactin/Wave1-Arp2/3 Complex. Neuroendocrinology 2020; 110:535-551. [PMID: 31509830 DOI: 10.1159/000503310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/11/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Synaptic plasticity is the neuronal capacity to modify the function and structure of dendritic spines (DS) in response to neuromodulators. Sex steroids, particularly 17β-estradiol (E2) and progesterone (P4), are key regulators in the control of DS formation through multiprotein complexes including WAVE1 protein, and are thus fundamental for the development of learning and memory. OBJECTIVES The aim of this work was to evaluate the molecular switch Cdk5 kinase/protein phosphatase 2A (PP2A) in the control of WAVE1 protein (phosphorylation/dephosphorylation) and the regulation of WAVE1 and cortactin to the Arp2/3 complex, in response to rapid treatments with E2 and P4 in cortical neuronal cells. RESULTS Rapid treatment with E2 and P4 modified neuronal morphology and significantly increased the number of DS. This effect was reduced by the use of a Cdk5 inhibitor (Roscovitine). In contrast, inhibition of PP2A with PP2A dominant negative construct significantly increased DS formation, evidencing the participation of kinase/phosphatase in the regulation of WAVE1 in DS formation induced by E2 and P4. Cortactin regulates DS formation via Src and PAK1 kinase induced by E2 and P4. Both cortactin and WAVE1 signal to Arp2/3 complex to synergistically promote actin nucleation. CONCLUSION These results suggest that E2 and P4 dynamically regulate neuron morphology through nongenomic signaling via cortactin/WAVE1-Arp2/3 complex. The control of these proteins is tightly orchestrated by phosphorylation, where kinases and phosphatases are essential for actin nucleation and, finally, DS formation. This work provides a deeper understanding of the biological actions of sex steroids in the regulation of DS turnover and neuronal plasticity processes.
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Affiliation(s)
- Ivonne Denise Uzair
- Laboratory of Signal Transduction and Cell Movement, Institute of Medicine and Experimental Biology of Cuyo (IMBECU), National Scientific and Technical Research Council (CONICET), Mendoza, Argentina
| | - Marina Ines Flamini
- Laboratory of Signal Transduction and Cell Movement, Institute of Medicine and Experimental Biology of Cuyo (IMBECU), National Scientific and Technical Research Council (CONICET), Mendoza, Argentina
| | - Angel Matias Sanchez
- Laboratory of Signal Transduction and Cell Movement, Institute of Medicine and Experimental Biology of Cuyo (IMBECU), National Scientific and Technical Research Council (CONICET), Mendoza, Argentina,
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12
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Zhou F, Xie J, Zhang S, Yin G, Gao Y, Zhang Y, Bo D, Li Z, Liu S, Feng C, Fan G. Lead, cadmium, arsenic, and mercury combined exposure disrupted synaptic homeostasis through activating the Snk-SPAR pathway. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 163:674-684. [PMID: 30099283 DOI: 10.1016/j.ecoenv.2018.07.116] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/19/2018] [Accepted: 07/28/2018] [Indexed: 06/08/2023]
Abstract
Lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) are among the leading toxic agents detected in the environment, and they have also been detected simultaneously in blood, serum, and urine samples of the general population. Meanwhile early neurologic effects and multiple interactions of Pb, Cd, As, and Hg had been found in children from environmentally polluted area. However, the current studies of these four metals were mostly limited to the interactions between any two metals, whereas the interaction characteristics between any three and four metals were rarely studied. In our study, we firstly explored the characteristics of the neurotoxic interactions among these four elements in nerve cells with factorial designs. The results showed that Pb+Cd+As+Hg co-exposure had a synergistic neurotoxic effect that was more severe than that induced by any two or three metals, when their individual metals were at human environmental exposure (in the blood of U.S. population) relevant levels and below no observed adverse effect levels (NOAELs). Therefore, Pb+Cd+As+Hg co-exposure at human environmental exposure relevant levels were further selected to examine synaptic homeostasis as the cellular and molecular foundation of learning and memory. We reported for the first time that Pb+Cd+As+Hg co-exposure induced dose-dependent decreases of the dendritic lengths and branching, as well as spine density and mature phenotype in primary hippocampal neurons, and the stimulated neurite outgrowths in NGF-differentiated PC12 cells. And the above synaptic homeostasis disruption was associated with serum induced kinase (Snk)-spine associated Rap GTPase activating protein (SPAR) pathway. Our study suggests that human environmental Pb, Cd, As, and Hg co-exposure has the potential to evoke synergistic neurotoxicity even if their individual metals are below NOAELs, which reinforces the need to control and regulate potential sources of metal contamination.
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Affiliation(s)
- Fankun Zhou
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Jie Xie
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Shuyun Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Guangming Yin
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Yanyan Gao
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Yuanyuan Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Dandan Bo
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Zongguang Li
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Sisi Liu
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Chang Feng
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Guangqin Fan
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China.
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13
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Zygmunt M, Hoinkis D, Hajto J, Piechota M, Skupień-Rabian B, Jankowska U, Kędracka-Krok S, Rodriguez Parkitna J, Korostyński M. Expression of alternatively spliced variants of the Dclk1 gene is regulated by psychotropic drugs. BMC Neurosci 2018; 19:55. [PMID: 30208879 PMCID: PMC6134793 DOI: 10.1186/s12868-018-0458-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 09/06/2018] [Indexed: 01/05/2023] Open
Abstract
Background The long-term effects of psychotropic drugs are associated with the reversal of disease-related alterations through the reorganization and normalization of neuronal connections. Molecular factors that trigger drug-induced brain plasticity remain only partly understood. Doublecortin-like kinase 1 (Dclk1) possesses microtubule-polymerizing activity during synaptic plasticity and neurogenesis. However, the Dclk1 gene shows a complex profile of transcriptional regulation, with two alternative promoters and exon splicing patterns that suggest the expression of multiple isoforms with different kinase activities. Results Here, we applied next-generation sequencing to analyze changes in the expression of Dclk1 gene isoforms in the brain in response to several psychoactive drugs with diverse pharmacological mechanisms of action. We used bioinformatics tools to define the range and levels of Dclk1 transcriptional regulation in the mouse nucleus accumbens and prefrontal cortex. We also sought to investigate the presence of DCLK1-derived peptides using mass spectrometry. We detected 15 transcripts expressed from the Dclk1 locus (FPKM > 1), including 2 drug-regulated variants (fold change > 2). Drugs that act on serotonin receptors (5-HT2A/C) regulate a subset of Dclk1 isoforms in a brain-region-specific manner. The strongest influence was observed for the mianserin-induced expression of an isoform with intron retention. The drug-activated expression of novel alternative Dclk1 isoforms was validated using qPCR. The drug-regulated isoform contains genetic variants of DCLK1 that have been previously associated with schizophrenia and hyperactivity disorder in humans. We identified a short peptide that might originate from the novel DCLK1 protein product. Moreover, protein domains encoded by the regulated variant indicate their potential involvement in the negative regulation of the canonical DCLK1 protein. Conclusions In summary, we identified novel isoforms of the neuroplasticity-related gene Dclk1 that are expressed in the brain in response to psychotropic drug treatments. Electronic supplementary material The online version of this article (10.1186/s12868-018-0458-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Magdalena Zygmunt
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland
| | - Dżesika Hoinkis
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland
| | - Jacek Hajto
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland
| | - Marcin Piechota
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland
| | - Bożena Skupień-Rabian
- Laboratory of Proteomics and Mass Spectrometry, Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Urszula Jankowska
- Laboratory of Proteomics and Mass Spectrometry, Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Sylwia Kędracka-Krok
- Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Rodriguez Parkitna
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland
| | - Michał Korostyński
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland.
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Henderson NT, Dalva MB. EphBs and ephrin-Bs: Trans-synaptic organizers of synapse development and function. Mol Cell Neurosci 2018; 91:108-121. [PMID: 30031105 PMCID: PMC6159941 DOI: 10.1016/j.mcn.2018.07.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 12/31/2022] Open
Abstract
Synapses are specialized cell-cell junctions that underlie the function of neural circuits by mediating communication between neurons. Both the formation and function of synapses require tight coordination of signaling between pre- and post-synaptic neurons. Trans-synaptic organizing molecules are important mediators of such signaling. Here we discuss how the EphB and ephrin-B families of trans-synaptic organizing proteins direct synapse formation during early development and regulate synaptic function and plasticity at mature synapses. Finally, we highlight recent evidence linking the synaptic organizing role of EphBs and ephrin-Bs to diseases of maladaptive synaptic function and plasticity.
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Affiliation(s)
- Nathan T Henderson
- The Jefferson Synaptic Biology Center, Department of Neuroscience, The Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Jefferson Hospital for Neuroscience, Suite 463, 900 Walnut St., Philadelphia, PA 19107, United States
| | - Matthew B Dalva
- The Jefferson Synaptic Biology Center, Department of Neuroscience, The Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Jefferson Hospital for Neuroscience, Suite 463, 900 Walnut St., Philadelphia, PA 19107, United States.
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15
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Ephexin1 Is Required for Eph-Mediated Limb Trajectory of Spinal Motor Axons. J Neurosci 2018; 38:2043-2056. [PMID: 29363583 DOI: 10.1523/jneurosci.2257-17.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 01/10/2018] [Accepted: 01/15/2018] [Indexed: 11/21/2022] Open
Abstract
The precise assembly of a functional nervous system relies on the guided migration of axonal growth cones, which is made possible by signals transmitted to the cytoskeleton by cell surface-expressed guidance receptors. We investigated the function of ephexin1, a Rho guanine nucleotide exchange factor, as an essential growth-cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show that ephexin1 is expressed in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb. Ephexin1 loss of function and gain of function using in ovo electroporation in chick LMC neurons, of either sex, perturbed LMC axon trajectory selection, demonstrating an essential role of ephexin1 in motor axon guidance. In addition, ephexin1 loss in mice of either sex led to LMC axon trajectory selection errors. We also show that ephexin1 knockdown attenuates the growth preference of LMC neurites against ephrins in vitro and Eph receptor-mediated retargeting of LMC axons in vivo, suggesting that ephexin1 is required in Eph-mediated LMC motor axon guidance. Finally, both ephexin1 knockdown and ectopic expression of nonphosphorylatable ephexin1 mutant attenuated the retargeting of LMC axons caused by Src overexpression, implicating ephexin1 as an Src target in Eph signal relay in this context. In summary, our findings demonstrate that ephexin1 is essential for motor axon guidance and suggest an important role in relaying ephrin:Eph signals that mediate motor axon trajectory selection.SIGNIFICANCE STATEMENT The proper development of functioning neural circuits requires precise nerve connections among neurons or between neurons and their muscle targets. The Eph tyrosine kinase receptors expressed in neurons are important in many contexts during neural-circuit formation, such as axon outgrowth, axon guidance, and synaptic formation, and have been suggested to be involved in neurodegenerative disorders, including amyotrophic lateral sclerosis and Alzheimer's disease. To dissect the mechanism of Eph signal relay, we studied ephexin1 gain of function and loss of function and found ephexin1 essential for the development of limb nerves toward their muscle targets, concluding that it functions as an intermediary to relay Eph signaling in this context. Our work could thus shed new light on the molecular mechanisms controlling neuromuscular connectivity during embryonic development.
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16
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Locke C, Machida K, Tucker CL, Wu Y, Yu J. Optogenetic activation of EphB2 receptor in dendrites induced actin polymerization by activating Arg kinase. Biol Open 2017; 6:1820-1830. [PMID: 29158322 PMCID: PMC5769660 DOI: 10.1242/bio.029900] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Erythropoietin-producing hepatocellular (Eph) receptors regulate a wide array of developmental processes by responding to cell-cell contacts. EphB2 is well-expressed in the brain and known to be important for dendritic spine development, as well as for the maintenance of the synapses, although the mechanisms of these functions have not been fully understood. Here we studied EphB2's functions in hippocampal neurons with an optogenetic approach, which allowed us to specify spatial regions of signal activation and monitor in real-time the consequences of signal activation. We designed and constructed OptoEphB2, a genetically encoded photoactivatable EphB2. Photoactivation of OptoEphB2 in fibroblast cells induced receptor phosphorylation and resulted in cell rounding ------- a well-known cellular response to EphB2 activation. In contrast, local activation of OptoEphb2 in dendrites of hippocampal neurons induces rapid actin polymerization, resulting dynamic dendritic filopodial growth. Inhibition of Rac1 and CDC42 did not abolish OptoEphB2-induced actin polymerization. Instead, we identified Abelson tyrosine-protein kinase 2 (Abl2/Arg) as a necessary effector in OptoEphB2-induced filopodia growth in dendrites. These findings provided new mechanistic insight into EphB2's role in neural development and demonstrated the advantage of OptoEphB as a new tool for studying EphB signaling.
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Affiliation(s)
- Clifford Locke
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Kazuya Machida
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | | | - Yi Wu
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Ji Yu
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
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17
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Matsuda S, Kawamoto K, Miyamoto K, Tsuji A, Yuasa K. PCTK3/CDK18 regulates cell migration and adhesion by negatively modulating FAK activity. Sci Rep 2017; 7:45545. [PMID: 28361970 PMCID: PMC5374530 DOI: 10.1038/srep45545] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/01/2017] [Indexed: 12/19/2022] Open
Abstract
PCTAIRE kinase 3 (PCTK3) is a member of the cyclin dependent kinase family, but its physiological function remains unknown. We previously reported that PCTK3-knockdown HEK293T cells showed actin accumulation at the leading edge, suggesting that PCTK3 is involved in the regulation of actin reorganization. In this study, we investigated the physiological function and downstream signal transduction molecules of PCTK3. PCTK3 knockdown in HEK293T cells increased cell motility and RhoA/Rho-associated kinase activity as compared with control cells. We also found that phosphorylation at residue Tyr-397 in focal adhesion kinase (FAK) was increased in PCTK3-knockdown cells. FAK phosphorylation at Tyr-397 was increased in response to fibronectin stimulation, whereas its phosphorylation was suppressed by PCTK3. In addition, excessive expression of PCTK3 led to the formation of filopodia during the early stages of cell adhesion in HeLa cells. These results indicate that PCTK3 controls actin cytoskeleton dynamics by negatively regulating the FAK/Rho signaling pathway.
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Affiliation(s)
- Shinya Matsuda
- Department of Biological Science and Technology, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8506, Japan
| | - Kohei Kawamoto
- Department of Biological Science and Technology, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8506, Japan
| | - Kenji Miyamoto
- Department of Biological Science and Technology, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8506, Japan
| | - Akihiko Tsuji
- Department of Biological Science and Technology, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8506, Japan.,Department of Bioscience and Bioindustry, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8513, Japan
| | - Keizo Yuasa
- Department of Biological Science and Technology, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8506, Japan.,Department of Bioscience and Bioindustry, Tokushima University Graduate School, Minamijosanjima, Tokushima 770-8513, Japan
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18
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Wang X, Sun J, Li C, Mao B. EphA7 modulates apical constriction of hindbrain neuroepithelium during neurulation in Xenopus. Biochem Biophys Res Commun 2016; 479:759-765. [DOI: 10.1016/j.bbrc.2016.09.138] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 09/26/2016] [Indexed: 11/29/2022]
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19
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Regional Regulation of Purkinje Cell Dendritic Spines by Integrins and Eph/Ephrins. PLoS One 2016; 11:e0158558. [PMID: 27518800 PMCID: PMC4982633 DOI: 10.1371/journal.pone.0158558] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/19/2016] [Indexed: 02/02/2023] Open
Abstract
Climbing fibres and parallel fibres compete for dendritic space on Purkinje cells in the cerebellum. Normally, climbing fibres populate the proximal dendrites, where they suppress the multiple small spines typical of parallel fibres, leading to their replacement by the few large spines that contact climbing fibres. Previous work has shown that ephrins acting via EphA4 are a signal for this change in spine type and density. We have used an in vitro culture model in which to investigate the ephrin effect on Purkinje cell dendritic spines and the role of integrins in these changes. We found that integrins α3, α5 and β4 are present in many of the dendritic spines of cultured Purkinje cells. pFAK, the main downstream signalling molecule from integrins, has a similar distribution, although the intenstity of pFAK staining and the percentage of pFAK+ spines was consistently higher in the proximal dendrites. Activating integrins with Mg2+ led to an increase in the intensity of pFAK staining and an increase in the proportion of pFAK+ spines in both the proximal and distal dendrites, but no change in spine length, density or morphology. Blocking integrin binding with an RGD-containing peptide led to a reduction in spine length, with more stubby spines on both proximal and distal dendrites. Treatment of the cultures with ephrinA3-Fc chimera suppressed dendritic spines specifically on the proximal dendrites and there was also a decrease of pFAK in spines on this domain. This effect was blocked by simultaneous activation of integrins with Mn2+. We conclude that Eph/ephrin signaling regulates proximal dendritic spines in Purkinje cells by inactivating integrin downstream signalling.
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20
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Prospéri MT, Lépine P, Dingli F, Paul-Gilloteaux P, Martin R, Loew D, Knölker HJ, Coudrier E. Myosin 1b functions as an effector of EphB signaling to control cell repulsion. J Cell Biol 2016. [PMID: 26195670 PMCID: PMC4508888 DOI: 10.1083/jcb.201501018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Myosin 1b functions as an effector of EphB2/ephrinB signaling and controls cell morphology and cell repulsion. Eph receptors and their membrane-tethered ligands, the ephrins, have important functions in embryo morphogenesis and in adult tissue homeostasis. Eph/ephrin signaling is essential for cell segregation and cell repulsion. This process is accompanied by morphological changes and actin remodeling that drives cell segregation and tissue patterning. The actin cortex must be mechanically coupled to the plasma membrane to orchestrate the cell morphology changes. Here, we demonstrate that myosin 1b that can mechanically link the membrane to the actin cytoskeleton interacts with EphB2 receptors via its tail and is tyrosine phosphorylated on its tail in an EphB2-dependent manner. Myosin 1b regulates the redistribution of myosin II in actomyosin fibers and the formation of filopodia at the interface of ephrinB1 and EphB2 cells, which are two processes mediated by EphB2 signaling that contribute to cell repulsion. Together, our results provide the first evidence that a myosin 1 functions as an effector of EphB2/ephrinB signaling, controls cell morphology, and thereby cell repulsion.
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Affiliation(s)
| | - Priscilla Lépine
- Institut Curie, Centre de Recherche, F-75248 Paris, France Université Pierre et Marie Curie, F-75252 Paris, France
| | - Florent Dingli
- Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie, Centre de Recherche, F-75248 Paris, France
| | - Perrine Paul-Gilloteaux
- Institut Curie, Centre de Recherche, F-75248 Paris, France Cell and Tissue Imaging Facility (PICT-IBiSA), Centre National de la Recherche Scientifique, UMR 144, Paris F-75248, France
| | - René Martin
- Department of Chemistry, Technische Univesität, 01069 Dresden, Germany
| | - Damarys Loew
- Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie, Centre de Recherche, F-75248 Paris, France
| | | | - Evelyne Coudrier
- Institut Curie, Centre de Recherche, F-75248 Paris, France Cell and Tissue Imaging Facility (PICT-IBiSA), Centre National de la Recherche Scientifique, UMR 144, Paris F-75248, France
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21
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Nikolakopoulou AM, Koeppen J, Garcia M, Leish J, Obenaus A, Ethell IM. Astrocytic Ephrin-B1 Regulates Synapse Remodeling Following Traumatic Brain Injury. ASN Neuro 2016; 8:1-18. [PMID: 26928051 PMCID: PMC4774052 DOI: 10.1177/1759091416630220] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 12/31/2015] [Indexed: 01/06/2023] Open
Abstract
Traumatic brain injury (TBI) can result in tissue alterations distant from the site of the initial injury, which can trigger pathological changes within hippocampal circuits and are thought to contribute to long-term cognitive and neuropsychological impairments. However, our understanding of secondary injury mechanisms is limited. Astrocytes play an important role in brain repair after injury and astrocyte-mediated mechanisms that are implicated in synapse development are likely important in injury-induced synapse remodeling. Our studies suggest a new role of ephrin-B1, which is known to regulate synapse development in neurons, in astrocyte-mediated synapse remodeling following TBI. Indeed, we observed a transient upregulation of ephrin-B1 immunoreactivity in hippocampal astrocytes following moderate controlled cortical impact model of TBI. The upregulation of ephrin-B1 levels in hippocampal astrocytes coincided with a decline in the number of vGlut1-positive glutamatergic input to CA1 neurons at 3 days post injury even in the absence of hippocampal neuron loss. In contrast, tamoxifen-induced ablation of ephrin-B1 from adult astrocytes in ephrin-B1loxP/yERT2-CreGFAP mice accelerated the recovery of vGlut1-positive glutamatergic input to CA1 neurons after TBI. Finally, our studies suggest that astrocytic ephrin-B1 may play an active role in injury-induced synapse remodeling through the activation of STAT3-mediated signaling in astrocytes. TBI-induced upregulation of STAT3 phosphorylation within the hippocampus was suppressed by astrocyte-specific ablation of ephrin-B1 in vivo, whereas the activation of ephrin-B1 in astrocytes triggered an increase in STAT3 phosphorylation in vitro. Thus, regulation of ephrin-B1 signaling in astrocytes may provide new therapeutic opportunities to aid functional recovery after TBI.
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Affiliation(s)
| | - Jordan Koeppen
- Biomedical Sciences Division, School of Medicine, University of California Riverside, CA, USA Cell, Molecular, and Developmental Biology graduate program, University of California Riverside, CA, USA
| | - Michael Garcia
- Biomedical Sciences Division, School of Medicine, University of California Riverside, CA, USA
| | - Joshua Leish
- Biomedical Sciences Division, School of Medicine, University of California Riverside, CA, USA
| | - Andre Obenaus
- Department of Pediatrics, School of Medicine, Loma Linda University, CA, USA
| | - Iryna M Ethell
- Biomedical Sciences Division, School of Medicine, University of California Riverside, CA, USA Cell, Molecular, and Developmental Biology graduate program, University of California Riverside, CA, USA
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22
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Cuberos H, Vallée B, Vourc'h P, Tastet J, Andres CR, Bénédetti H. Roles of LIM kinases in central nervous system function and dysfunction. FEBS Lett 2015; 589:3795-806. [PMID: 26545494 DOI: 10.1016/j.febslet.2015.10.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 10/21/2015] [Accepted: 10/28/2015] [Indexed: 12/30/2022]
Abstract
LIM kinase 1 (LIMK1) and LIM kinase 2 (LIMK2) regulate actin dynamics by phosphorylating cofilin. In this review, we outline studies that have shown an involvement of LIMKs in neuronal function and we detail some of the pathways and molecular mechanisms involving LIMKs in neurodevelopment and synaptic plasticity. We also review the involvement of LIMKs in neuronal diseases and emphasize the differences in the regulation of LIMKs expression and mode of action. We finally present the existence of a cofilin-independent pathway also involved in neuronal function. A better understanding of the differences between both LIMKs and of the precise molecular mechanisms involved in their mode of action and regulation is now required to improve our understanding of the physiopathology of the neuronal diseases associated with LIMKs.
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Affiliation(s)
- H Cuberos
- CNRS UPR 4301, CBM, Orléans, France; UMR INSERM U930, Université François-Rabelais, Tours, France
| | - B Vallée
- CNRS UPR 4301, CBM, Orléans, France
| | - P Vourc'h
- UMR INSERM U930, Université François-Rabelais, Tours, France; CHRU de Tours, Service de Biochimie et de Biologie Moléculaire, Tours, France
| | - J Tastet
- University Medical Center Utrecht, Brain Center Rudolf Magnus, Utrecht, Netherlands
| | - C R Andres
- UMR INSERM U930, Université François-Rabelais, Tours, France; CHRU de Tours, Service de Biochimie et de Biologie Moléculaire, Tours, France
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23
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Terriente J, Pujades C. Cell segregation in the vertebrate hindbrain: a matter of boundaries. Cell Mol Life Sci 2015; 72:3721-30. [PMID: 26089248 PMCID: PMC11113478 DOI: 10.1007/s00018-015-1953-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 05/06/2015] [Accepted: 06/08/2015] [Indexed: 02/07/2023]
Abstract
Segregating cells into compartments during embryonic development is essential for growth and pattern formation. In the developing hindbrain, boundaries separate molecularly, physically and neuroanatomically distinct segments called rhombomeres. After rhombomeric cells have acquired their identity, interhombomeric boundaries restrict cell intermingling between adjacent rhombomeres and act as signaling centers to pattern the surrounding tissue. Several works have stressed the relevance of Eph/ephrin signaling in rhombomeric cell sorting. Recent data have unveiled the role of this pathway in the assembly of actomyosin cables as an important mechanism for keeping cells from different rhombomeres segregated. In this Review, we will provide a short summary of recent evidences gathered in different systems suggesting that physical actomyosin barriers can be a general mechanism for tissue separation. We will discuss current evidences supporting a model where cell-cell signaling pathways, such as Eph/ephrin, govern compartmental cell sorting through modulation of the actomyosin cytoskeleton and cell adhesive properties to prevent cell intermingling.
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Affiliation(s)
- Javier Terriente
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Dr Aiguader 88, 08003, Barcelona, Spain.
| | - Cristina Pujades
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Dr Aiguader 88, 08003, Barcelona, Spain.
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24
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Abstract
Proteases regulate a myriad of cell functions, both in normal and disease states. In addition to protein turnover, they regulate a range of signaling processes, including those mediated by Eph receptors and their ephrin ligands. A variety of proteases is reported to directly cleave Ephs and/or ephrins under different conditions, to promote receptor and/or ligand shedding, and regulate receptor/ligand internalisation and signaling. They also cleave other adhesion proteins in response to Eph-ephrin interactions, to indirectly facilitate Eph-mediated functions. Proteases thus contribute to Eph/ephrin mediated changes in cell-cell and cell-matrix interactions, in cell morphology and in cell migration and invasion, in a manner which appears to be tightly regulated by, and co-ordinated with, Eph signaling. This review summarizes the current literature describing the function and regulation of protease activities during Eph/ephrin-mediated cell signaling.
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Affiliation(s)
- Lakmali Atapattu
- a Department of Biochemistry and Molecular Biology ; Monash University , Victoria ; Australia
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25
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Buricchi F, Giannoni E, Grimaldi G, Parri M, Raugei G, Ramponi G, Chiarugi P. Redox Regulation of Ephrin/Integrin Cross-Talk. Cell Adh Migr 2014. [DOI: 10.4161/cam.3911] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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26
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Armendáriz BG, Masdeu MDM, Soriano E, Ureña JM, Burgaya F. The diverse roles and multiple forms of focal adhesion kinase in brain. Eur J Neurosci 2014; 40:3573-90. [DOI: 10.1111/ejn.12737] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 08/25/2014] [Indexed: 02/04/2023]
Affiliation(s)
- Beatriz G. Armendáriz
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Maria del Mar Masdeu
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Eduardo Soriano
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Jesús M. Ureña
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
| | - Ferran Burgaya
- Department of Biologia Cellular; Fac Biologia; Universitat de Barcelona; Diagonal, 643 08028 Barcelona Spain
- Parc Científic de Barcelona; Barcelona Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Ciberned (ISC III); Madrid Spain
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27
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Genetic removal of matrix metalloproteinase 9 rescues the symptoms of fragile X syndrome in a mouse model. J Neurosci 2014; 34:9867-79. [PMID: 25057190 DOI: 10.1523/jneurosci.1162-14.2014] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fmr1 knock-out (ko) mice display key features of fragile X syndrome (FXS), including delayed dendritic spine maturation and FXS-associated behaviors, such as poor socialization, obsessive-compulsive behavior, and hyperactivity. Here we provide conclusive evidence that matrix metalloproteinase-9 (MMP-9) is necessary to the development of FXS-associated defects in Fmr1 ko mice. Genetic disruption of Mmp-9 rescued key aspects of Fmr1 deficiency, including dendritic spine abnormalities, abnormal mGluR5-dependent LTD, as well as aberrant behaviors in open field and social novelty tests. Remarkably, MMP-9 deficiency also corrected non-neural features of Fmr1 deficiency-specifically macroorchidism-indicating that MMP-9 dysregulation contributes to FXS-associated abnormalities outside the CNS. Further, MMP-9 deficiency suppressed elevations of Akt, mammalian target of rapamycin, and eukaryotic translation initiation factor 4E phosphorylation seen in Fmr1 ko mice, which are also associated with other autistic spectrum disorders. These findings establish that MMP-9 is critical to the mechanisms responsible for neural and non-neural aspects of the FXS phenotype.
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28
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Focal adhesion kinase function in neuronal development. Curr Opin Neurobiol 2014; 27:89-95. [DOI: 10.1016/j.conb.2014.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/17/2014] [Accepted: 03/09/2014] [Indexed: 11/21/2022]
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29
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Cho HJ, Hwang YS, Mood K, Ji YJ, Lim J, Morrison DK, Daar IO. EphrinB1 interacts with CNK1 and promotes cell migration through c-Jun N-terminal kinase (JNK) activation. J Biol Chem 2014; 289:18556-68. [PMID: 24825906 DOI: 10.1074/jbc.m114.558809] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The Eph receptors and their membrane-bound ligands, ephrins, play important roles in various biological processes such as cell adhesion and movement. The transmembrane ephrinBs transduce reverse signaling in a tyrosine phosphorylation-dependent or -independent, as well as PDZ-dependent manner. Here, we show that ephrinB1 interacts with Connector Enhancer of KSR1 (CNK1) in an EphB receptor-independent manner. In cultured cells, cotransfection of ephrinB1 with CNK1 increases JNK phosphorylation. EphrinB1/CNK1-mediated JNK activation is reduced by overexpression of dominant-negative RhoA. Overexpression of CNK1 alone is sufficient for activation of RhoA; however, both ephrinB1 and CNK1 are required for JNK phosphorylation. Co-immunoprecipitation data showed that ephrinB1 and CNK1 act as scaffold proteins that connect RhoA and JNK signaling components, such as p115RhoGEF and MKK4. Furthermore, adhesion to fibronectin or active Src overexpression increases ephrinB1/CNK1 binding, whereas blocking Src activity by a pharmacological inhibitor decreases not only ephrinB1/CNK1 binding, but also JNK activation. EphrinB1 overexpression increases cell motility, however, CNK1 depletion by siRNA abrogates ephrinB1-mediated cell migration and JNK activation. Moreover, Rho kinase inhibitor or JNK inhibitor treatment suppresses ephrinB1-mediated cell migration. Taken together, our findings suggest that CNK1 is required for ephrinB1-induced JNK activation and cell migration.
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Affiliation(s)
- Hee Jun Cho
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Yoo-Seok Hwang
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Kathleen Mood
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Yon Ju Ji
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Junghwa Lim
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Deborah K Morrison
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
| | - Ira O Daar
- From the Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, National Institutes of Health, Frederick, Maryland 21702
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30
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Krupke OA, Burke RD. Eph-Ephrin signaling and focal adhesion kinase regulate actomyosin-dependent apical constriction of ciliary band cells. Development 2014; 141:1075-84. [DOI: 10.1242/dev.100123] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Apical constriction typically accompanies inward folding of an epithelial sheet. In recent years there has been progress in understanding mechanisms of apical constriction and their contribution to morphogenetic processes. Sea urchin embryos form a specialized region of ectoderm, the ciliary band, which is a strip of epithelium, three to five cells wide, encircling the oral ectoderm and functioning in larval swimming and feeding. Ciliary band cells exhibit distinctive apical-basal elongation, have narrow apices bearing a cilium, and are planar polarized, so that cilia beat away from the mouth. Here, we show that filamentous actin and phosphorylated myosin light chain are uniquely distributed in ciliary band cells. Inhibition of myosin phosphorylation or actin polymerization perturbs this distribution and blocks apical constriction. During ciliary band formation, Sp-Ephrin and Sp-Eph expression overlap in the presumptive ciliary band. Knockdown of Sp-Eph or Sp-Ephrin, or treatment with an Eph kinase inhibitor interferes with actomyosin networks, accumulation of phosphorylated FAK (pY397FAK), and apical constriction. The cytoplasmic domain of Sp-Eph, fused to GST and containing a single amino acid substitution reported as kinase dead, will pull down pY397FAK from embryo lysates. As well, pY397FAK colocalizes with Sp-Eph in a JNK-dependent, planar polarized manner on latitudinal apical junctions of the ciliary band and this polarization is dissociable from apical constriction. We propose that Sp-Eph and pY397FAK function together in an apical complex that is necessary for remodeling actomyosin to produce centripetal forces causing apical constriction. Morphogenesis of ciliary band cells is a unique example of apical constriction in which receptor-mediated cell shape change produces a strip of specialized tissue without an accompanying folding of epithelium.
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Affiliation(s)
- Oliver A. Krupke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Robert D. Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
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31
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Sala C, Segal M. Dendritic spines: the locus of structural and functional plasticity. Physiol Rev 2014; 94:141-88. [PMID: 24382885 DOI: 10.1152/physrev.00012.2013] [Citation(s) in RCA: 338] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The introduction of high-resolution time lapse imaging and molecular biological tools has changed dramatically the rate of progress towards the understanding of the complex structure-function relations in synapses of central spiny neurons. Standing issues, including the sequence of molecular and structural processes leading to formation, morphological change, and longevity of dendritic spines, as well as the functions of dendritic spines in neurological/psychiatric diseases are being addressed in a growing number of recent studies. There are still unsettled issues with respect to spine formation and plasticity: Are spines formed first, followed by synapse formation, or are synapses formed first, followed by emergence of a spine? What are the immediate and long-lasting changes in spine properties following exposure to plasticity-producing stimulation? Is spine volume/shape indicative of its function? These and other issues are addressed in this review, which highlights the complexity of molecular pathways involved in regulation of spine structure and function, and which contributes to the understanding of central synaptic interactions in health and disease.
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32
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Wehrle-Haller B, Bastmeyer M. Intracellular signaling and perception of neuronal scaffold through integrins and their adapter proteins. PROGRESS IN BRAIN RESEARCH 2014; 214:443-60. [DOI: 10.1016/b978-0-444-63486-3.00018-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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33
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Sato K, Suzuki T, Yamaguchi Y, Kitade Y, Nagase T, Ueda H. PLEKHG2/FLJ00018, a Rho family-specific guanine nucleotide exchange factor, is tyrosine phosphorylated via the EphB2/cSrc signaling pathway. Cell Signal 2014; 26:691-6. [PMID: 24378532 DOI: 10.1016/j.cellsig.2013.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 12/18/2013] [Indexed: 10/25/2022]
Abstract
PLEKHG2/FLJ00018, a Rho family-specific guanine nucleotide exchange factor (RhoGEF), is activated by heterotrimeric GTP-binding protein (G protein) Gβγ subunits, and in turn activates the small G protein Rac and Cdc42, which have been shown to mediate signaling pathways leading to actin cytoskeletal reorganization. In the present study, we show that co-expression of the constitutively active mutant of cSrc, a non-receptor tyrosine kinase, and PLEKHG2 induced the tyrosine phosphorylation of PLEKHG2 in HEK293 cells. Through deletion and base substitution mutagenesis we have identified Tyr489 of PLEKHG2 as the site phosphorylated by cSrc. Furthermore, using a high-throughput src homology 2 (SH2) domain binding assay, the SH2 domain of ABL1 and the PI 3-kinse regulator subunit (PIK3R3) were identified as candidates for the binding partner of tyrosine-phosphorylated PLEKHG2. The interaction between PLEKHG2 and the full-length of PIK3R3, but not ABL1, occurs in a tyrosine-phosphorylation-dependent manner. Furthermore, PLEKHG2 is tyrosine phosphorylated at Tyr489 by ephrinB2 receptor signaling via cSrc. Investigation of the physiological function of tyrosine phosphorylation at Tyr489 in PLEKHG2 remains a subject for future studies.
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Affiliation(s)
- Katsuya Sato
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Takahiro Suzuki
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | | | - Yukio Kitade
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan; Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Takahiro Nagase
- Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan
| | - Hiroshi Ueda
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan; Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan.
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34
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Lisabeth EM, Falivelli G, Pasquale EB. Eph receptor signaling and ephrins. Cold Spring Harb Perspect Biol 2013; 5:5/9/a009159. [PMID: 24003208 DOI: 10.1101/cshperspect.a009159] [Citation(s) in RCA: 292] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Eph receptors are the largest of the RTK families. Like other RTKs, they transduce signals from the cell exterior to the interior through ligand-induced activation of their kinase domain. However, the Eph receptors also have distinctive features. Instead of binding soluble ligands, they generally mediate contact-dependent cell-cell communication by interacting with surface-associated ligands-the ephrins-on neighboring cells. Eph receptor-ephrin complexes emanate bidirectional signals that affect both receptor- and ephrin-expressing cells. Intriguingly, ephrins can also attenuate signaling by Eph receptors coexpressed in the same cell. Additionally, Eph receptors can modulate cell behavior independently of ephrin binding and kinase activity. The Eph/ephrin system regulates many developmental processes and adult tissue homeostasis. Its abnormal function has been implicated in various diseases, including cancer. Thus, Eph receptors represent promising therapeutic targets. However, more research is needed to better understand the many aspects of their complex biology that remain mysterious.
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Affiliation(s)
- Erika M Lisabeth
- Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA
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35
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Xia Y, Luo C, Dai S, Yao D. Increased EphA/ephrinA expression in hippocampus of pilocarpine treated mouse. Epilepsy Res 2013; 105:20-9. [PMID: 23352741 DOI: 10.1016/j.eplepsyres.2013.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 12/17/2012] [Accepted: 01/03/2013] [Indexed: 01/21/2023]
Abstract
PURPOSE EphA family receptor tyrosine kinases and their ephrinA ligands are involved in patterning axonal connections during brain development. Although it has been evidenced that these molecules continue to play a key role in synaptic reorganization and plasticity in normal and injured adult brains, their effect still remains unclear during epileptogenesis. Temporal lobe epilepsy (TLE) is the most common form of adult focal epilepsy and often associates with sclerosis of the hippocampus and mossy fiber sprouting (MFS). The purpose of this study is to evaluate the relationship between EphA/ephrinA molecules and epileptogenesis after status epilepticus (SE). METHOD A mouse model of chronic temporal lobe epilepsy was prepared by intraperitoneal administration of pilocarpine. EphAs/ephrinAs expression levels of the mouse hippocampus areas were detected at different time points after SE by PCR, in situ hybridization and immunohistochemistry. Mossy fiber sprouting was estimated by Neo-Timm staining. RESULT EphAs/ephrinAs were widely distributed in the hippocampus area. EphA10 and ephrinA4 were increased significantly following epileptogenesis, and mossy fiber sprouting appeared after SE. CONCLUSION The up-regulation of EphA/ephrinA expression after SE suggests that they are involved in the pilocarpine-induced epileptogenesis.
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Affiliation(s)
- Yang Xia
- Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China.
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36
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Cheadle L, Biederer T. The novel synaptogenic protein Farp1 links postsynaptic cytoskeletal dynamics and transsynaptic organization. ACTA ACUST UNITED AC 2012; 199:985-1001. [PMID: 23209303 PMCID: PMC3518221 DOI: 10.1083/jcb.201205041] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Synaptic adhesion organizes synapses, yet the signaling pathways that drive and integrate synapse development remain incompletely understood. We screened for regulators of these processes by proteomically analyzing synaptic membranes lacking the synaptogenic adhesion molecule SynCAM 1. This identified FERM, Rho/ArhGEF, and Pleckstrin domain protein 1 (Farp1) as strongly reduced in SynCAM 1 knockout mice. Farp1 regulates dendritic filopodial dynamics in immature neurons, indicating roles in synapse formation. Later in development, Farp1 is postsynaptic and its 4.1 protein/ezrin/radixin/moesin (FERM) domain binds SynCAM 1, assembling a synaptic complex. Farp1 increases synapse number and modulates spine morphology, and SynCAM 1 requires Farp1 for promoting spines. In turn, SynCAM 1 loss reduces the ability of Farp1 to elevate spine density. Mechanistically, Farp1 activates the GTPase Rac1 in spines downstream of SynCAM 1 clustering, and promotes F-actin assembly. Farp1 furthermore triggers a retrograde signal regulating active zone composition via SynCAM 1. These results reveal a postsynaptic signaling pathway that engages transsynaptic interactions to coordinate synapse development.
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Affiliation(s)
- Lucas Cheadle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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37
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A chemical genetic approach reveals distinct EphB signaling mechanisms during brain development. Nat Neurosci 2012; 15:1645-54. [PMID: 23143520 PMCID: PMC3509236 DOI: 10.1038/nn.3249] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/01/2012] [Indexed: 12/15/2022]
Abstract
EphB receptor tyrosine kinases control multiple steps in nervous system development. However, it remains unclear whether EphBs regulate these different developmental processes directly or indirectly. In addition, as EphBs signal through multiple mechanisms, it has been challenging to define which signaling functions of EphBs regulate particular developmental events. To address these issues, we engineered triple knockin mice in which the kinase activity of three neuronally expressed EphBs can be rapidly, reversibly, and specifically blocked. Using these mice we demonstrate that the tyrosine kinase activity of EphBs is required for axon guidance in vivo. By contrast, EphB-mediated synaptogenesis occurs normally when the kinase activity of EphBs is inhibited suggesting that EphBs mediate synapse development by an EphB tyrosine kinase-independent mechanism. Taken together, these experiments reveal that EphBs control axon guidance and synaptogenesis by distinct mechanisms, and provide a new mouse model for dissecting EphB function in development and disease.
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38
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Santiago-Medina M, Myers JP, Gomez TM. Imaging adhesion and signaling dynamics in Xenopus laevis growth cones. Dev Neurobiol 2012; 72:585-99. [PMID: 21465668 DOI: 10.1002/dneu.20886] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Xenopus laevis provides a robust model system to study cellular signaling and downstream processes during development both in vitro and in vivo. Intracellular signals must function within highly restricted spatial and temporal domains to activate specific downstream targets and cellular processes. Combining the versatility of developing Xenopus neurons with advances in fluorescent protein biosensors and imaging technologies has allowed many dynamic cellular processes to be visualized. This review will focus on the techniques we use to visualize and measure cell signaling, motility and adhesion by quantitative fluorescence microscopy in vitro and in vivo.
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Affiliation(s)
- Miguel Santiago-Medina
- Department of Neuroscience, Neuroscience Training Program, University of Wisconsin-Madison, WI 53706, USA
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39
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Suo L, Lu H, Ying G, Capecchi MR, Wu Q. Protocadherin clusters and cell adhesion kinase regulate dendrite complexity through Rho GTPase. J Mol Cell Biol 2012; 4:362-76. [PMID: 22730554 DOI: 10.1093/jmcb/mjs034] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dendritic patterning and spine morphogenesis are crucial for the assembly of neuronal circuitry to ensure normal brain development and synaptic connectivity as well as for understanding underlying mechanisms of neuropsychiatric diseases and cognitive impairments. The Rho GTPase family is essential for neuronal morphogenesis and synaptic plasticity by modulating and reorganizing the cytoskeleton. Here, we report that protocadherin (Pcdh) clusters and cell adhesion kinases (CAKs) play important roles in dendritic development and spine elaboration. The knockout of the entire Pcdhα cluster results in the dendritic simplification and spine loss in CA1 pyramidal neurons in vivo and in cultured primary hippocampal neurons in vitro. The knockdown of the whole Pcdhγ cluster or in combination with the Pcdhα knockout results in similar dendritic and spine defects in vitro. The overexpression of proline-rich tyrosine kinase 2 (Pyk2, also known as CAKβ, RAFTK, FAK2, and CADTK) recapitulates these defects and its knockdown rescues the phenotype. Moreover, the genetic deletion of the Pcdhα cluster results in phosphorylation and activation of Pyk2 and focal adhesion kinase (Fak) and the inhibition of Rho GTPases in vivo. Finally, the overexpression of Pyk2 leads to inactivation of Rac1 and, conversely, the constitutive active Rac1 rescues the dendritic and spine morphogenesis defects caused by the knockout of the Pcdhα cluster and the knockdown of the Pcdhγ cluster. Thus, the involvement of the Pcdh-CAK-Rho GTPase pathway in the dendritic development and spine morphogenesis has interesting implications for proper assembly of neuronal connections in the brain.
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Affiliation(s)
- Lun Suo
- Key Laboratory of Systems Biomedicine (Ministry of Education), Center for Comparative Medicine, Institute of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
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Nievergall E, Lackmann M, Janes PW. Eph-dependent cell-cell adhesion and segregation in development and cancer. Cell Mol Life Sci 2012; 69:1813-42. [PMID: 22204021 PMCID: PMC11114713 DOI: 10.1007/s00018-011-0900-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/06/2011] [Accepted: 11/28/2011] [Indexed: 01/23/2023]
Abstract
Numerous studies attest to essential roles for Eph receptors and their ephrin ligands in controlling cell positioning and tissue patterning during normal and oncogenic development. These studies suggest multiple, sometimes contradictory, functions of Eph-ephrin signalling, which under different conditions can promote either spreading and cell-cell adhesion or cytoskeletal collapse, cell rounding, de-adhesion and cell-cell segregation. A principle determinant of the balance between these two opposing responses is the degree of receptor/ligand clustering and activation. This equilibrium is likely altered in cancers and modulated by somatic mutations of key Eph family members that have emerged as candidate cancer markers in recent profiling studies. In addition, cross-talk amongst Ephs and with other signalling pathways significantly modulates cell-cell adhesion, both between and within Eph- and ephrin-expressing cell populations. This review summarises our current understanding of how Eph receptors control cell adhesion and morphology, and presents examples demonstrating the importance of these events in normal development and cancer.
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Affiliation(s)
- Eva Nievergall
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800 Australia
- Present Address: Haematology Department, SA Pathology, Frome Road, Adelaide, SA 5000 Australia
| | - Martin Lackmann
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800 Australia
| | - Peter W. Janes
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800 Australia
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Sheffler-Collins SI, Dalva MB. EphBs: an integral link between synaptic function and synaptopathies. Trends Neurosci 2012; 35:293-304. [PMID: 22516618 DOI: 10.1016/j.tins.2012.03.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/08/2012] [Accepted: 03/08/2012] [Indexed: 11/19/2022]
Abstract
The assembly and function of neuronal circuits rely on selective cell-cell interactions to control axon targeting, generate pre- and postsynaptic specialization and recruit neurotransmitter receptors. In neurons, EphB receptor tyrosine kinases mediate excitatory synaptogenesis early during development, and then later coordinate synaptic function by controlling synaptic glutamate receptor localization and function. EphBs direct synapse formation and function to regulate cellular morphology through downstream signaling mechanisms and by interacting with glutamate receptors. In humans, defective EphB-dependent regulation of NMDA receptor (NMDAR) localization and function is associated with neurological disorders, including neuropathic pain, anxiety disorders and Alzheimer's disease (AD). Here, we propose that EphBs act as a central organizer of excitatory synapse formation and function, and as a key regulator of diseases linked to NMDAR dysfunction.
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Affiliation(s)
- Sean I Sheffler-Collins
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, 900 Walnut Street, Suite 462, Philadelphia, PA 19107, USA
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Zhou L, Jones EV, Murai KK. EphA signaling promotes actin-based dendritic spine remodeling through slingshot phosphatase. J Biol Chem 2012; 287:9346-59. [PMID: 22282498 DOI: 10.1074/jbc.m111.302802] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Actin cytoskeletal remodeling plays a critical role in transforming the morphology of subcellular structures across various cell types. In the brain, restructuring of dendritic spines through actin cytoskeleletal reorganization is implicated in the regulation of synaptic efficacy and the storage of information in neural circuits. However, the upstream pathways that provoke actin-based spine changes remain only partly understood. Here we show that EphA receptor signaling remodels spines by triggering a sequence of events involving actin filament rearrangement and synapse/spine reorganization. Rapid EphA signaling over minutes activates the actin filament depolymerizing/severing factor cofilin, alters F-actin distribution in spines, and causes transient spine elongation through the phosphatases slingshot 1 (SSH1) and calcineurin/protein phosphatase 2B (PP2B). This early phase of spine extension is followed by synaptic reorganization events that take place over minutes to hours and involve the relocation of pre/postsynaptic components and ultimately spine retraction. Thus, EphA receptors utilize discrete cellular and molecular pathways to promote actin-based structural plasticity of excitatory synapses.
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Affiliation(s)
- Lei Zhou
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
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43
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Singh A, Winterbottom E, Daar IO. Eph/ephrin signaling in cell-cell and cell-substrate adhesion. Front Biosci (Landmark Ed) 2012; 17:473-97. [PMID: 22201756 DOI: 10.2741/3939] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cell-cell and cell-matrix adhesion are critical processes for the formation and maintenance of tissue patterns during development, as well as control of invasion and metastasis of cancer cells. Although great strides have been made regarding our understanding of the processes that play a role in cell adhesion and cell movement, the precise mechanisms by which diverse signaling events regulate cell and tissue architecture are poorly understood. One group of cell surface molecules, Eph receptor tyrosine kinases, and their membrane-bound ligands, ephrins, are key regulators in these processes. It is the ability of Eph/ephrin signaling pathways to regulate cell-cell adhesion and motility that establishes this family as a formidable system for regulating tissue separation and morphogenesis. Moreover, the de-regulation of this signaling system is linked to the promotion of more aggressive and metastatic tumors in humans.
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Affiliation(s)
- Arvinder Singh
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
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Chen Y, Fu AKY, Ip NY. Eph receptors at synapses: implications in neurodegenerative diseases. Cell Signal 2011; 24:606-11. [PMID: 22120527 DOI: 10.1016/j.cellsig.2011.11.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 11/05/2011] [Indexed: 12/16/2022]
Abstract
Precise regulation of synapse formation, maintenance and plasticity is crucial for normal cognitive function, and synaptic failure has been suggested as one of the hallmarks of neurodegenerative diseases. In this review, we describe the recent progress in our understanding of how the receptor tyrosine kinase Ephs and their ligands ephrins regulate dendritic spine morphogenesis, synapse formation and maturation, as well as synaptic plasticity. In particular, we discuss the emerging evidence implicating that deregulation of Eph/ephrin signaling contributes to the aberrant synaptic functions associated with cognitive impairment in Alzheimer's disease. Understanding how Eph/ephrin regulates synaptic function may therefore provide new insights into the development of therapeutic agents against neurodegenerative diseases.
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Affiliation(s)
- Yu Chen
- Divison of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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Sloniowski S, Ethell IM. Looking forward to EphB signaling in synapses. Semin Cell Dev Biol 2011; 23:75-82. [PMID: 22040917 DOI: 10.1016/j.semcdb.2011.10.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 10/17/2011] [Indexed: 11/24/2022]
Abstract
Eph receptors and their ligands ephrins comprise a complex signaling system with diverse functions that span a wide range of tissues and developmental stages. The variety of Eph receptor functions stems from their ability to mediate bidirectional signaling through trans-cellular Eph/ephrin interactions. Initially thought to act by directing repulsion between cells, Ephs have also been demonstrated to induce and maintain cell adhesive responses at excitatory synapses in the central nervous system. EphB receptors are essential to the development and maintenance of dendritic spines, which accommodate the postsynaptic sites of most glutamatergic excitatory synapses in the brain. Functions of EphB receptors are not limited to control of the actin cytoskeleton in dendritic spines, as EphB receptors are also involved in the formation of functional synaptic specializations through the regulation of glutamate receptor trafficking and functions. In addition, EphB receptors have recently been linked to the pathophysiology of Alzheimer's disease and neuropathic pain, thus becoming promising targets for therapeutic interventions. In this review, we discuss recent findings on EphB receptor functions in synapses, as well as the mechanisms of bidirectional trans-synaptic ephrin-B/EphB receptor signaling that shape dendritic spines and influence post-synaptic differentiation.
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Affiliation(s)
- Slawomir Sloniowski
- Division of Biomedical Sciences and Graduate Program in Neuroscience, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA
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Monje FJ, Kim EJ, Pollak DD, Cabatic M, Li L, Baston A, Lubec G. Focal adhesion kinase regulates neuronal growth, synaptic plasticity and hippocampus-dependent spatial learning and memory. Neurosignals 2011; 20:1-14. [PMID: 21952616 DOI: 10.1159/000330193] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 06/20/2011] [Indexed: 01/07/2023] Open
Abstract
The focal adhesion kinase (FAK) is a non-receptor tyrosine kinase abundantly expressed in the mammalian brain and highly enriched in neuronal growth cones. Inhibitory and facilitatory activities of FAK on neuronal growth have been reported and its role in neuritic outgrowth remains controversial. Unlike other tyrosine kinases, such as the neurotrophin receptors regulating neuronal growth and plasticity, the relevance of FAK for learning and memory in vivo has not been clearly defined yet. A comprehensive study aimed at determining the role of FAK in neuronal growth, neurotransmitter release and synaptic plasticity in hippocampal neurons and in hippocampus-dependent learning and memory was therefore undertaken using the mouse model. Gain- and loss-of-function experiments indicated that FAK is a critical regulator of hippocampal cell morphology. FAK mediated neurotrophin-induced neuritic outgrowth and FAK inhibition affected both miniature excitatory postsynaptic potentials and activity-dependent hippocampal long-term potentiation prompting us to explore the possible role of FAK in spatial learning and memory in vivo. Our data indicate that FAK has a growth-promoting effect, is importantly involved in the regulation of the synaptic function and mediates in vivo hippocampus-dependent spatial learning and memory.
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Affiliation(s)
- Francisco J Monje
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Vienna, Austria
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Michaluk P, Wawrzyniak M, Alot P, Szczot M, Wyrembek P, Mercik K, Medvedev N, Wilczek E, De Roo M, Zuschratter W, Muller D, Wilczynski GM, Mozrzymas JW, Stewart MG, Kaczmarek L, Wlodarczyk J. Influence of matrix metalloproteinase MMP-9 on dendritic spine morphology. J Cell Sci 2011; 124:3369-80. [PMID: 21896646 DOI: 10.1242/jcs.090852] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
An increasing body of data has shown that matrix metalloproteinase-9 (MMP-9), an extracellularly acting, Zn(2+)-dependent endopeptidase, is important not only for pathologies of the central nervous system but also for neuronal plasticity. Here, we use three independent experimental models to show that enzymatic activity of MMP-9 causes elongation and thinning of dendritic spines in the hippocampal neurons. These models are: a recently developed transgenic rat overexpressing autoactivating MMP-9, dissociated neuronal cultures, and organotypic neuronal cultures treated with recombinant autoactivating MMP-9. This dendritic effect is mediated by integrin β1 signalling. MMP-9 treatment also produces a change in the decay time of miniature synaptic currents; however, it does not change the abundance and localization of synaptic markers in dendritic protrusions. Our results, considered together with several recent studies, strongly imply that MMP-9 is functionally involved in synaptic remodelling.
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Affiliation(s)
- Piotr Michaluk
- Department of Molecular and Cellular Neurobiology, The Nencki Institute, Pasteura 3, 02-093 Warsaw, Poland.
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Transsynaptic EphB/Ephrin-B signaling regulates growth of presynaptic boutons required for classical conditioning. J Neurosci 2011; 31:8441-9. [PMID: 21653848 DOI: 10.1523/jneurosci.6343-10.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Learning-related presynaptic remodeling has been documented in only a few systems, and its molecular mechanisms are largely unknown. Here we describe a role for the bidirectional EphB/ephrin-B signaling system in structural plasticity of presynaptic nerve terminals using an in vitro model of classical conditioning. Conditioning or BDNF application induced significant growth of auditory nerve presynaptic boutons that convey the conditioned stimulus to abducens motor neurons. Interestingly, bouton enlargement occurred only for those synapses apposed to motor neuron dendrites rather than to somata. Phosphorylation of ephrin-B1, but not EphB2, was induced by both conditioning and BDNF application and was inhibited by postsynaptic injections of ephrin-B antibody. Finally, suppression of postsynaptic ephrin-B function inhibited presynaptic bouton enlargement that was rescued by activation of EphB2 by ephrin-B1-Fc. These data provide evidence for ephrin-B-induced EphB2 forward signaling in presynaptic structural plasticity during classical conditioning. They also reveal a functional interaction between BDNF/TrkB and the Eph/ephrin signaling systems in the coordination of presynaptic and postsynaptic modifications during conditioning.
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Cesa R, Premoselli F, Renna A, Ethell IM, Pasquale EB, Strata P. Eph receptors are involved in the activity-dependent synaptic wiring in the mouse cerebellar cortex. PLoS One 2011; 6:e19160. [PMID: 21559471 PMCID: PMC3084771 DOI: 10.1371/journal.pone.0019160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 03/25/2011] [Indexed: 11/19/2022] Open
Abstract
Eph receptor tyrosine kinases are involved in many cellular processes. In the developing brain, they act as migratory and cell adhesive cues while in the adult brain they regulate dendritic spine plasticity. Here we show a new role for Eph receptor signalling in the cerebellar cortex. Cerebellar Purkinje cells are innervated by two different excitatory inputs. The climbing fibres contact the proximal dendritic domain of Purkinje cells, where synapse and spine density is low; the parallel fibres contact the distal dendritic domain, where synapse and spine density is high. Interestingly, Purkinje cells have the intrinsic ability to generate a high number of spines over their entire dendritic arborisations, which can be innervated by the parallel fibres. However, the climbing fibre input continuously exerts an activity-dependent repression on parallel fibre synapses, thus confining them to the distal Purkinje cell dendritic domain. Such repression persists after Eph receptor activation, but is overridden by Eph receptor inhibition with EphA4/Fc in neonatal cultured cerebellar slices as well as mature acute cerebellar slices, following in vivo infusion of the EphA4/Fc inhibitor and in EphB receptor-deficient mice. When electrical activity is blocked in vivo by tetrodotoxin leading to a high spine density in Purkinje cell proximal dendrites, stimulation of Eph receptor activation recapitulates the spine repressive effects of climbing fibres. These results suggest that Eph receptor signalling mediates the repression of spine proliferation induced by climbing fibre activity in Purkinje cell proximal dendrites. Such repression is necessary to maintain the correct architecture of the cerebellar cortex.
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Affiliation(s)
- Roberta Cesa
- Department of Neuroscience, University of Turin, Turin, Italy
- National Neuroscience Institute-Italy at Turin University, Turin, Italy
| | | | - Annamaria Renna
- Department of Neuroscience, University of Turin, Turin, Italy
- National Neuroscience Institute-Italy at Turin University, Turin, Italy
| | - Iryna M. Ethell
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, United States of America
| | - Elena B. Pasquale
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Piergiorgio Strata
- National Neuroscience Institute-Italy at Turin University, Turin, Italy
- * E-mail:
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Schenk GJ, Vreugdenhil E, Hubens CJY, Veldhuisen B, de Kloet ER, Oitzl MS. Hippocampal CARP over-expression solidifies consolidation of contextual fear memories. Physiol Behav 2010; 102:323-31. [PMID: 21130104 DOI: 10.1016/j.physbeh.2010.11.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/15/2010] [Accepted: 11/18/2010] [Indexed: 01/13/2023]
Abstract
The Doublecortin-Like Kinase (DCLK) gene is involved in neuronal migration during development. Through alternative splicing the DCLK gene also produces a transcript called Ca(2+)/calmodulin dependent protein kinase (CaMK)-related peptide (CARP) that is expressed exclusively during adulthood in response to neuronal activity. The function of CARP, however, is poorly understood. To study CARP function, we have generated transgenic mice with over-expression of the CARP transcript in, amongst other brain areas, the hippocampus. We aimed to characterize possible behavioral adaptations of these mice by using a Pavlovian fear conditioning approach. This type of fear conditioning, in which both the hippocampus and amygdala are critically involved, allows studying the formation and extinction of fear related memories. We here report on the behavioral adaptations of two distinct transgenic lines: one with high levels of CARP in the hippocampus and amygdala, whilst the other has high levels of CARP in the hippocampal formation, but not in the amygdala. We tested both mouse lines separately by comparing them to their wild-type littermate controls. We provide evidence suggesting consolidation of contextual fear memories is strengthened in mice of both transgenic lines.
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Affiliation(s)
- Geert J Schenk
- Division of Medical Pharmacology, Leiden/Amsterdam Centre for Drug Research, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
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