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Lee J, Jeong Y, Park S, Kim S, Oh H, Jin JA, Sohn JW, Kim D, Shin HS, Do Heo W. Phospholipase C beta 1 in the dentate gyrus gates fear memory formation through regulation of neuronal excitability. SCIENCE ADVANCES 2024; 10:eadj4433. [PMID: 38959322 PMCID: PMC11221510 DOI: 10.1126/sciadv.adj4433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 05/28/2024] [Indexed: 07/05/2024]
Abstract
Memory processes rely on a molecular signaling system that balances the interplay between positive and negative modulators. Recent research has focused on identifying memory-regulating genes and their mechanisms. Phospholipase C beta 1 (PLCβ1), highly expressed in the hippocampus, reportedly serves as a convergence point for signal transduction through G protein-coupled receptors. However, the detailed role of PLCβ1 in memory function has not been elucidated. Here, we demonstrate that PLCβ1 in the dentate gyrus functions as a memory suppressor. We reveal that mice lacking PLCβ1 in the dentate gyrus exhibit a heightened fear response and impaired memory extinction, and this excessive fear response is repressed by upregulation of PLCβ1 through its overexpression or activation using a newly developed optogenetic system. Last, our results demonstrate that PLCβ1 overexpression partially inhibits exaggerated fear response caused by traumatic experience. Together, PLCβ1 is crucial in regulating contextual fear memory formation and potentially enhancing the resilience to trauma-related conditions.
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Affiliation(s)
- Jinsu Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Yeonji Jeong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Seahyung Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Sungsoo Kim
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Hyunsik Oh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Ju-Ae Jin
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Jong-Woo Sohn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Daesoo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Department of Brain and Cognitive Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Hee-Sup Shin
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Won Do Heo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Department of Brain and Cognitive Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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2
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Lee CT, Bell M, Bonilla-Quintana M, Rangamani P. Biophysical Modeling of Synaptic Plasticity. Annu Rev Biophys 2024; 53:397-426. [PMID: 38382115 DOI: 10.1146/annurev-biophys-072123-124954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Dendritic spines are small, bulbous compartments that function as postsynaptic sites and undergo intense biochemical and biophysical activity. The role of the myriad signaling pathways that are implicated in synaptic plasticity is well studied. A recent abundance of quantitative experimental data has made the events associated with synaptic plasticity amenable to quantitative biophysical modeling. Spines are also fascinating biophysical computational units because spine geometry, signal transduction, and mechanics work in a complex feedback loop to tune synaptic plasticity. In this sense, ideas from modeling cell motility can inspire us to develop multiscale approaches for predictive modeling of synaptic plasticity. In this article, we review the key steps in postsynaptic plasticity with a specific focus on the impact of spine geometry on signaling, cytoskeleton rearrangement, and membrane mechanics. We summarize the main experimental observations and highlight how theory and computation can aid our understanding of these complex processes.
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Affiliation(s)
- Christopher T Lee
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
| | - Miriam Bell
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
| | - Mayte Bonilla-Quintana
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
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3
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Calabrese B, Halpain S. MARCKS and PI(4,5)P 2 reciprocally regulate actin-based dendritic spine morphology. Mol Biol Cell 2024; 35:ar23. [PMID: 38088877 PMCID: PMC10881156 DOI: 10.1091/mbc.e23-09-0370] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/27/2023] [Accepted: 12/07/2023] [Indexed: 01/14/2024] Open
Abstract
Myristoylated, alanine-rich C-kinase substrate (MARCKS) is an F-actin and phospholipid binding protein implicated in numerous cellular activities, including the regulation of morphology in neuronal dendrites and dendritic spines. MARCKS contains a lysine-rich effector domain that mediates its binding to plasma membrane phosphatidylinositol-4,5-biphosphate (PI(4,5)P2) in a manner controlled by PKC and calcium/calmodulin. In neurons, manipulations of MARCKS concentration and membrane targeting strongly affect the numbers, shapes, and F-actin properties of dendritic spines, but the mechanisms remain unclear. Here, we tested the hypothesis that the effects of MARCKS on dendritic spine morphology are due to its capacity to regulate the availability of plasma membrane PI(4,5)P2. We observed that the concentration of free PI(4,5)P2 on the dendritic plasma membrane was inversely proportional to the concentration of MARCKS. Endogenous PI(4,5)P2 levels were increased or decreased, respectively, by acutely overexpressing either phosphatidylinositol-4-phosphate 5-kinase (PIP5K) or inositol polyphosphate 5-phosphatase (5ptase). PIP5K, like MARCKS depletion, induced severe spine shrinkage; 5ptase, like constitutively membrane-bound MARCKS, induced aberrant spine elongation. These phenotypes involved changes in actin properties driven by the F-actin severing protein cofilin. Collectively, these findings support a model in which neuronal activity regulates actin-dependent spine morphology through antagonistic interactions of MARCKS and PI(4,5)P2.
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Affiliation(s)
- Barbara Calabrese
- Department of Neurobiology, School of Biological Sciences, University of California San Diego and Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037
| | - Shelley Halpain
- Department of Neurobiology, School of Biological Sciences, University of California San Diego and Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037
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4
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Chen C, Khanthiyong B, Thaweetee-Sukjai B, Charoenlappanit S, Roytrakul S, Thanoi S, Reynolds GP, Nudmamud-Thanoi S. Proteomic association with age-dependent sex differences in Wisconsin Card Sorting Test performance in healthy Thai subjects. Sci Rep 2023; 13:20238. [PMID: 37981639 PMCID: PMC10658079 DOI: 10.1038/s41598-023-46750-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 11/04/2023] [Indexed: 11/21/2023] Open
Abstract
Sex differences in cognitive function exist, but they are not stable and undergo dynamic change during the lifespan. However, our understanding of how sex-related neural information transmission evolves with age is still in its infancy. This study utilized the Wisconsin Card Sorting Test (WCST) and the label-free proteomics method with bioinformatic analysis to investigate the molecular mechanisms underlying age-related sex differences in cognitive performance in 199 healthy Thai subjects (aged 20-70 years), as well as explore the sex-dependent protein complexes for predicting cognitive aging. The results showed that males outperformed females in two of the five WCST sub-scores: %Corrects and %Errors. Sex differences in these scores were related to aging, becoming noticeable in those over 60. At the molecular level, differently expressed individual proteins and protein complexes between both sexes are associated with the potential N-methyl-D-aspartate type glutamate receptor (NMDAR)-mediated excitotoxicity, with the NMDAR complex being enriched exclusively in elderly female samples. These findings provided a preliminary indication that healthy Thai females might be more susceptible to such neurotoxicity, as evidenced by their cognitive performance. NMDAR protein complex enrichment in serum could be proposed as a potential indication for predicting cognitive aging in healthy Thai females.
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Affiliation(s)
- Chen Chen
- Medical Science Graduate Program, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | | | | | - Sawanya Charoenlappanit
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Sittiruk Roytrakul
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Samur Thanoi
- School of Medical Sciences, University of Phayao, Phayao, Thailand.
| | - Gavin P Reynolds
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Sutisa Nudmamud-Thanoi
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand.
- Department of Anatomy, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand.
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5
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Hofbrucker-MacKenzie SA, Seemann E, Westermann M, Qualmann B, Kessels MM. Long-term depression in neurons involves temporal and ultra-structural dynamics of phosphatidylinositol-4,5-bisphosphate relying on PIP5K, PTEN and PLC. Commun Biol 2023; 6:366. [PMID: 37012315 PMCID: PMC10070498 DOI: 10.1038/s42003-023-04726-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
Synaptic plasticity involves proper establishment and rearrangement of structural and functional microdomains. Yet, visualization of the underlying lipid cues proved challenging. Applying a combination of rapid cryofixation, membrane freeze-fracturing, immunogold labeling and electron microscopy, we visualize and quantitatively determine the changes and the distribution of phosphatidylinositol-4,5-bisphosphate (PIP2) in the plasma membrane of dendritic spines and subareas thereof at ultra-high resolution. These efforts unravel distinct phases of PIP2 signals during induction of long-term depression (LTD). During the first minutes PIP2 rapidly increases in a PIP5K-dependent manner forming nanoclusters. PTEN contributes to a second phase of PIP2 accumulation. The transiently increased PIP2 signals are restricted to upper and middle spine heads. Finally, PLC-dependent PIP2 degradation provides timely termination of PIP2 cues during LTD induction. Together, this work unravels the spatial and temporal cues set by PIP2 during different phases after LTD induction and dissects the molecular mechanisms underlying the observed PIP2 dynamics.
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Affiliation(s)
- Sarah A Hofbrucker-MacKenzie
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Martin Westermann
- Center for Electron Microscopy, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
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6
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Droogers WJ, MacGillavry HD. Plasticity of postsynaptic nanostructure. Mol Cell Neurosci 2023; 124:103819. [PMID: 36720293 DOI: 10.1016/j.mcn.2023.103819] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
The postsynaptic density (PSD) of excitatory synapses is built from a wide variety of scaffolding proteins, receptors, and signaling molecules that collectively orchestrate synaptic transmission. Seminal work over the past decades has led to the identification and functional characterization of many PSD components. In contrast, we know far less about how these constituents are assembled within synapses, and how this organization contributes to synapse function. Notably, recent evidence from high-resolution microscopy studies and in silico models, highlights the importance of the precise subsynaptic structure of the PSD for controlling the strength of synaptic transmission. Even further, activity-driven changes in the distribution of glutamate receptors are acknowledged to contribute to long-term changes in synaptic efficacy. Thus, defining the mechanisms that drive structural changes within the PSD are important for a molecular understanding of synaptic transmission and plasticity. Here, we review the current literature on how the PSD is organized to mediate basal synaptic transmission and how synaptic activity alters the nanoscale organization of synapses to sustain changes in synaptic strength.
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Affiliation(s)
- W J Droogers
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands
| | - H D MacGillavry
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands.
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7
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Minadakis G, Tomazou M, Dietis N, Spyrou GM. Vir2Drug: a drug repurposing framework based on protein similarities between pathogens. Brief Bioinform 2022; 24:6895455. [PMID: 36513376 PMCID: PMC9851336 DOI: 10.1093/bib/bbac536] [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: 07/19/2022] [Revised: 10/25/2022] [Accepted: 11/08/2022] [Indexed: 12/15/2022] Open
Abstract
We draw from the assumption that similarities between pathogens at both pathogen protein and host protein level, may provide the appropriate framework to identify and rank candidate drugs to be used against a specific pathogen. Vir2Drug is a drug repurposing tool that uses network-based approaches to identify and rank candidate drugs for a specific pathogen, combining information obtained from: (a) ranked pathogen-to-pathogen networks based on protein similarities between pathogens, (b) taxonomy distance between pathogens and (c) drugs targeting specific pathogen's and host proteins. The underlying pathogen networks are used to screen drugs by means of specific methodologies that account for either the host or pathogen's protein targets. Vir2Drug is a useful and yet informative tool for drug repurposing against known or unknown pathogens especially in periods where the emergence for repurposed drugs plays significant role in handling viral outbreaks, until reaching a vaccine. The web tool is available at: https://bioinformatics.cing.ac.cy/vir2drug, https://vir2drug.cing-big.hpcf.cyi.ac.cy.
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Affiliation(s)
- George Minadakis
- Corresponding author: George Minadakis, Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371 Ayios Dometios, PO Box 23462, 1683 Nicosia, Cyprus. Tel.: +357-22-392852; Fax: +357-22-358238; E-mail:
| | - Marios Tomazou
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371 Ayios Dometios, Nicosia, Cyprus
- PO Box 23462, 1683 Nicosia, Cyprus,The Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371 Ayios Dometios, PO Box 23462, 1683 Nicosia, Cyprus
| | - Nikolas Dietis
- Medical School, University of Cyprus, Nicosia 1678, Cyprus
| | - George M Spyrou
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371 Ayios Dometios, Nicosia, Cyprus
- PO Box 23462, 1683 Nicosia, Cyprus,The Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371 Ayios Dometios, PO Box 23462, 1683 Nicosia, Cyprus
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8
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Chen X, Crosby KC, Feng A, Purkey AM, Aronova MA, Winters CA, Crocker VT, Leapman RD, Reese TS, Dell’Acqua ML. Palmitoylation of A-kinase anchoring protein 79/150 modulates its nanoscale organization, trafficking, and mobility in postsynaptic spines. Front Synaptic Neurosci 2022; 14:1004154. [PMID: 36186623 PMCID: PMC9521714 DOI: 10.3389/fnsyn.2022.1004154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/23/2022] [Indexed: 11/29/2022] Open
Abstract
A-kinase anchoring protein 79-human/150-rodent (AKAP79/150) organizes signaling proteins to control synaptic plasticity. AKAP79/150 associates with the plasma membrane and endosomes through its N-terminal domain that contains three polybasic regions and two Cys residues that are reversibly palmitoylated. Mutations abolishing palmitoylation (AKAP79/150 CS) reduce its endosomal localization and association with the postsynaptic density (PSD). Here we combined advanced light and electron microscopy (EM) to characterize the effects of AKAP79/150 palmitoylation on its postsynaptic nanoscale organization, trafficking, and mobility in hippocampal neurons. Immunogold EM revealed prominent extrasynaptic membrane AKAP150 labeling with less labeling at the PSD. The label was at greater distances from the spine membrane for AKAP150 CS than WT in the PSD but not in extra-synaptic locations. Immunogold EM of GFP-tagged AKAP79 WT showed that AKAP79 adopts a vertical, extended conformation at the PSD with its N-terminus at the membrane, in contrast to extrasynaptic locations where it adopts a compact or open configurations of its N- and C-termini with parallel orientation to the membrane. In contrast, GFP-tagged AKAP79 CS was displaced from the PSD coincident with disruption of its vertical orientation, while proximity and orientation with respect to the extra-synaptic membrane was less impacted. Single-molecule localization microscopy (SMLM) revealed a heterogeneous distribution of AKAP150 with distinct high-density, nano-scale regions (HDRs) overlapping the PSD but more prominently located in the extrasynaptic membrane for WT and the CS mutant. Thick section scanning transmission electron microscopy (STEM) tomography revealed AKAP150 immunogold clusters similar in size to HDRs seen by SMLM and more AKAP150 labeled endosomes in spines for WT than for CS, consistent with the requirement for AKAP palmitoylation in endosomal trafficking. Hidden Markov modeling of single molecule tracking data revealed a bound/immobile fraction and two mobile fractions for AKAP79 in spines, with the CS mutant having shorter dwell times and faster transition rates between states than WT, suggesting that palmitoylation stabilizes individual AKAP molecules in various spine subpopulations. These data demonstrate that palmitoylation fine tunes the nanoscale localization, mobility, and trafficking of AKAP79/150 in dendritic spines, which might have profound effects on its regulation of synaptic plasticity.
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Affiliation(s)
- Xiaobing Chen
- Laboratory of Neurobiology, National Institute of Neurological Diseases and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, United States
- *Correspondence: Xiaobing Chen,
| | - Kevin C. Crosby
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, United States
| | - Austin Feng
- Laboratory of Neurobiology, National Institute of Neurological Diseases and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Alicia M. Purkey
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, United States
| | - Maria A. Aronova
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Christine A. Winters
- Laboratory of Neurobiology, National Institute of Neurological Diseases and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Virginia T. Crocker
- Laboratory of Neurobiology, National Institute of Neurological Diseases and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Richard D. Leapman
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Thomas S. Reese
- Laboratory of Neurobiology, National Institute of Neurological Diseases and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, United States
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, United States
- Mark L. Dell’Acqua,
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9
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Saponaro A, Lolicato M. Editorial: The key role of lipids in the regulation of ion channels. Front Physiol 2022; 13:1000082. [PMID: 36160863 PMCID: PMC9490410 DOI: 10.3389/fphys.2022.1000082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- Andrea Saponaro
- Department of Biosciences, University of Milano, Milano, Italy
- *Correspondence: Andrea Saponaro,
| | - Marco Lolicato
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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10
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Zhang H, Sheng ZF, Wang J, Zheng PR, Kang XL, Chang HM, Yeh ETH, Li DP. Signaling pathways involved in NMDA-induced suppression of M-channels in corticotropin-releasing hormone neurons in central amygdala. J Neurochem 2022; 161:478-491. [PMID: 35583089 DOI: 10.1111/jnc.15647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 05/02/2022] [Accepted: 05/11/2022] [Indexed: 11/27/2022]
Abstract
Glutamate N-methyl-D-aspartate (NMDA) receptors (NMDARs) and Kv7/M channels are importantly involved in regulating neuronal activity involved in various physiological and pathological functions. Corticotropin-releasing hormone (CRH)-expressing neurons in the central nucleus of the amygdala (CeA) critically mediate autonomic response during stress. However, the interaction between NMDA receptors and Kv7/M channels in the CRHCeA neurons remains unclear. In this study, we identified rat CRHCeA neurons through the expression of an AAV viral vector-mediated enhanced green fluorescent protein (eGFP) driven by the rat CRH promoter. M-currents carried by Kv7/M channels were recorded using the whole-cell patch-clamp approach in eGFP-tagged CRHCeA neurons in brain slices. Acute exposure to NMDA significantly reduced M-currents recorded from the CRHCeA neurons. NMDA-induced suppression of M-currents was eliminated by chelating intracellular Ca2+ , supplying phosphatidylinositol 4,5-bisphosphate (PIP2) intracellularly, or blocking phosphoinositide3-kinase (PI3K). In contrast, inhibiting protein kinase C (PKC) or calmodulin did not alter NMDA-induced suppression of M-currents. Sustained exposure of NMDA decreased Kv7.3 membrane protein levels and suppressed M-currents, while the Kv7.2 expression levels remained unaltered. Pre-treatment of brain slices with PKC inhibitors alleviated the decreases in Kv7.3 and reduction of M-currents in CRHCeA neurons induced by NMDA. PKC inhibitors did not alter Kv7.2 and Kv7.3 membrane protein levels and M-currents in CRHCeA neurons. These data suggest that transient activation of NMDARs suppresses M-currents through the Ca2+ -dependent PI3K-PIP2 signaling pathway. In contrast, sustained activation of NMDARs reduces Kv7.3 protein expression and suppresses M-currents through a PKC-dependent pathway.
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Affiliation(s)
- Hua Zhang
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia MO 65212
| | - Zhao-Fu Sheng
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia MO 65212
| | - Jingxiong Wang
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia MO 65212
| | - Pei Ru Zheng
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia MO 65212
| | - Xun Lei Kang
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia MO 65212
| | - Hui-Ming Chang
- Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences
| | - Edward T H Yeh
- Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences
| | - De-Pei Li
- Center for Precision Medicine, Department of Medicine, School of Medicine University of Missouri, Columbia MO 65212
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11
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de la Cruz L, Kushmerick C, Sullivan JM, Kruse M, Vivas O. Hippocampal neurons maintain a large PtdIns(4)P pool that results in faster PtdIns(4,5)P2 synthesis. J Gen Physiol 2022; 154:213016. [PMID: 35179558 PMCID: PMC8906353 DOI: 10.1085/jgp.202113001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/01/2022] [Accepted: 01/24/2022] [Indexed: 12/24/2022] Open
Abstract
PtdIns(4,5)P2 is a signaling lipid central to the regulation of multiple cellular functions. It remains unknown how PtdIns(4,5)P2 fulfills various functions in different cell types, such as regulating neuronal excitability, synaptic release, and astrocytic function. Here, we compared the dynamics of PtdIns(4,5)P2 synthesis in hippocampal neurons and astrocytes with the kidney-derived tsA201 cell line. The experimental approach was to (1) measure the abundance and rate of PtdIns(4,5)P2 synthesis and precursors using specific biosensors, (2) measure the levels of PtdIns(4,5)P2 and its precursors using mass spectrometry, and (3) use a mathematical model to compare the metabolism of PtdIns(4,5)P2 in cell types with different proportions of phosphoinositides. The rate of PtdIns(4,5)P2 resynthesis in hippocampal neurons after depletion by cholinergic or glutamatergic stimulation was three times faster than for tsA201 cells. In tsA201 cells, resynthesis of PtdIns(4,5)P2 was dependent on the enzyme PI4K. In contrast, in hippocampal neurons, the resynthesis rate of PtdIns(4,5)P2 was insensitive to the inhibition of PI4K, indicating that it does not require de novo synthesis of the precursor PtdIns(4)P. Measurement of phosphoinositide abundance indicated a larger pool of PtdIns(4)P, suggesting that hippocampal neurons maintain sufficient precursor to restore PtdIns(4,5)P2 levels. Quantitative modeling indicates that the measured differences in PtdIns(4)P pool size and higher activity of PI4K can account for the experimental findings and indicates that high PI4K activity prevents depletion of PtdIns(4)P. We further show that the resynthesis of PtdIns(4,5)P2 is faster in neurons than astrocytes, providing context to the relevance of cell type–specific mechanisms to sustain PtdIns(4,5)P2 levels.
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Affiliation(s)
- Lizbeth de la Cruz
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Christopher Kushmerick
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jane M Sullivan
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Martin Kruse
- Department of Biology and Program in Neuroscience, Bates College, Lewiston, ME
| | - Oscar Vivas
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
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12
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Deletion of Grin1 in mouse megakaryocytes reveals NMDA receptor role in platelet function and proplatelet formation. Blood 2022; 139:2673-2690. [PMID: 35245376 DOI: 10.1182/blood.2021014000] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 02/18/2022] [Indexed: 11/20/2022] Open
Abstract
The process of proplatelet formation (PPF) requires coordinated interaction between megakaryocytes (MKs) and the extracellular matrix (ECM), followed by a dynamic reorganization of the actin and microtubule cytoskeleton. Localized fluxes of intracellular calcium ions (Ca2+) facilitate MK-ECM interaction and PPF. Glutamate-gated N-methyl-D--aspartate receptor (NMDAR) is highly permeable to Ca2+. NMDAR antagonists inhibit MK maturation ex vivo, however there is no in vivo data. Using the Cre-loxP system, we generated a platelet lineage-specific knockout mouse model of reduced NMDAR function in MKs and platelets (Pf4-Grin1-/- mice). Effects of NMDAR deletion were examined using well-established assays of platelet function and production in vivo and ex vivo. We found that Pf4-Grin1-/- mice had defects in megakaryopoiesis, thrombopoiesis and platelet function, which manifested as reduced platelet counts, lower rates of platelet production in the immune model of thrombocytopenia, and a prolonged tail bleeding time. Platelet activation was impaired to a range of agonists associated with reduced Ca2+ responses, including metabotropic-like, and defective platelet spreading. MKs showed reduced colony and proplatelet formation. Impaired reorganization of intracellular F-actin and α-tubulin was identified as the main cause of reduced platelet function and production. Pf4-Grin1-/- MKs also had lower levels of transcripts encoding crucial ECM elements and enzymes, suggesting NMDAR signaling is involved in ECM remodeling. In summary, we provide the first genetic evidence that NMDAR plays an active role in platelet function and production. NMDARs regulate PPF through the mechanism that involves MK-ECM interaction and cytoskeletal reorganization. Our results suggest that NMDAR helps guide PPF in vivo.
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Kawai T, Okamura Y. Spotlight on the Binding Affinity of Ion Channels for Phosphoinositides: From the Study of Sperm Flagellum. Front Physiol 2022; 13:834180. [PMID: 35197868 PMCID: PMC8859416 DOI: 10.3389/fphys.2022.834180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/07/2022] [Indexed: 11/21/2022] Open
Abstract
The previous studies revealed that many types of ion channels have sensitivity to PtdIns(4,5)P2, which has been mainly shown using heterologous expression system. On the other hand, there remains few evidence showing that PtdIns(4,5)P2 natively regulate the ion channel activities in physiological context. Our group recently discovered that a sperm specific K+ channel, Slo3, is natively regulated by PtdIns(4,5)P2 in sperm flagellum. Very interestingly, a principal piece, to which Slo3 specifically localized, had extremely low density of PtdIns(4,5)P2 compared to the regular cell plasma membrane. Furthermore, our studies and the previous ones also revealed that Slo3 had much stronger PtdIns(4,5)P2 affinity than KCNQ2/3 channels, which are widely regulated by endogenous PtdIns(4,5)P2 in neurons. Thus, the high-PtdIns(4,5)P2 affinity of Slo3 is well-adapted to the specialized PtdIns(4,5)P2 environment in the principal piece. This study sheds light on the relationship between PtdIns(4,5)P2-affinity of ion channels and their PtdIns(4,5)P2 environment in native cells. We discuss the current understanding about PtdIns(4,5)P2 affinity of diverse ion channels and their possible regulatory mechanism in native cellular environment.
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Affiliation(s)
- Takafumi Kawai
- Integrative Physiology Program, Graduate School of Medicine, Osaka University, Suita, Japan
- *Correspondence: Takafumi Kawai,
| | - Yasushi Okamura
- Integrative Physiology Program, Graduate School of Medicine, Osaka University, Suita, Japan
- Graduate School of Frontier Bioscience, Osaka University, Suita, Japan
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14
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Vallés AS, Barrantes FJ. Nanoscale Sub-Compartmentalization of the Dendritic Spine Compartment. Biomolecules 2021; 11:1697. [PMID: 34827695 PMCID: PMC8615865 DOI: 10.3390/biom11111697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 01/04/2023] Open
Abstract
Compartmentalization of the membrane is essential for cells to perform highly specific tasks and spatially constrained biochemical functions in topographically defined areas. These membrane lateral heterogeneities range from nanoscopic dimensions, often involving only a few molecular constituents, to micron-sized mesoscopic domains resulting from the coalescence of nanodomains. Short-lived domains lasting for a few milliseconds coexist with more stable platforms lasting from minutes to days. This panoply of lateral domains subserves the great variety of demands of cell physiology, particularly high for those implicated in signaling. The dendritic spine, a subcellular structure of neurons at the receiving (postsynaptic) end of central nervous system excitatory synapses, exploits this compartmentalization principle. In its most frequent adult morphology, the mushroom-shaped spine harbors neurotransmitter receptors, enzymes, and scaffolding proteins tightly packed in a volume of a few femtoliters. In addition to constituting a mesoscopic lateral heterogeneity of the dendritic arborization, the dendritic spine postsynaptic membrane is further compartmentalized into spatially delimited nanodomains that execute separate functions in the synapse. This review discusses the functional relevance of compartmentalization and nanodomain organization in synaptic transmission and plasticity and exemplifies the importance of this parcelization in various neurotransmitter signaling systems operating at dendritic spines, using two fast ligand-gated ionotropic receptors, the nicotinic acetylcholine receptor and the glutamatergic receptor, and a second-messenger G-protein coupled receptor, the cannabinoid receptor, as paradigmatic examples.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca 8000, Argentina;
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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15
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Schmalz JT, Kumar G. A computational model of dopaminergic modulation of hippocampal Schaffer collateral-CA1 long-term plasticity. J Comput Neurosci 2021; 50:51-90. [PMID: 34431067 DOI: 10.1007/s10827-021-00793-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/14/2021] [Accepted: 05/28/2021] [Indexed: 10/20/2022]
Abstract
Dopamine plays a critical role in modulating the long-term synaptic plasticity of the hippocampal Schaffer collateral-CA1 pyramidal neuron synapses (SC-CA1), a widely accepted cellular model of learning and memory. Limited results from hippocampal slice experiments over the last four decades have shown that the timing of the activation of dopamine D1/D5 receptors relative to a high/low-frequency stimulation (HFS/LFS) in SC-CA1 synapses regulates the modulation of HFS/LFS-induced long-term potentiation/depression (LTP/LTD) in these synapses. However, the existing literature lacks a complete picture of how various concentrations of D1/D5 agonists and the relative timing between the activation of D1/D5 receptors and LTP/LTD induction by HFS/LFS, affect the spatiotemporal modulation of SC-CA1 synaptic dynamics. In this paper, we have developed a computational model, a first of its kind, to make quantitative predictions of the temporal dose-dependent modulation of the HFS/LFS induced LTP/LTD in SC-CA1 synapses by various D1/D5 agonists. Our model combines the biochemical effects with the electrical effects at the electrophysiological level. We have estimated the model parameters from the published electrophysiological data, available from diverse hippocampal CA1 slice experiments, in a Bayesian framework. Our modeling results demonstrate the capability of our model in making quantitative predictions of the available experimental results under diverse HFS/LFS protocols. The predictions from our model show a strong nonlinear dependency of the modulated LTP/LTD by D1/D5 agonists on the relative timing between the activated D1/D5 receptors and the HFS/LFS protocol and the applied concentration of D1/D5 agonists.
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16
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Purkey AM, Dell’Acqua ML. Phosphorylation-Dependent Regulation of Ca 2+-Permeable AMPA Receptors During Hippocampal Synaptic Plasticity. Front Synaptic Neurosci 2020; 12:8. [PMID: 32292336 PMCID: PMC7119613 DOI: 10.3389/fnsyn.2020.00008] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/18/2020] [Indexed: 01/28/2023] Open
Abstract
Experience-dependent learning and memory require multiple forms of plasticity at hippocampal and cortical synapses that are regulated by N-methyl-D-aspartate receptors (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors (NMDAR, AMPAR). These plasticity mechanisms include long-term potentiation (LTP) and depression (LTD), which are Hebbian input-specific mechanisms that rapidly increase or decrease AMPAR synaptic strength at specific inputs, and homeostatic plasticity that globally scales-up or -down AMPAR synaptic strength across many or even all inputs. Frequently, these changes in synaptic strength are also accompanied by a change in the subunit composition of AMPARs at the synapse due to the trafficking to and from the synapse of receptors lacking GluA2 subunits. These GluA2-lacking receptors are most often GluA1 homomeric receptors that exhibit higher single-channel conductance and are Ca2+-permeable (CP-AMPAR). This review article will focus on the role of protein phosphorylation in regulation of GluA1 CP-AMPAR recruitment and removal from hippocampal synapses during synaptic plasticity with an emphasis on the crucial role of local signaling by the cAMP-dependent protein kinase (PKA) and the Ca2+calmodulin-dependent protein phosphatase 2B/calcineurin (CaN) that is coordinated by the postsynaptic scaffold protein A-kinase anchoring protein 79/150 (AKAP79/150).
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Affiliation(s)
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, United States
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17
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Lin L, Lyu Q, Kwan PY, Zhao J, Fan R, Chai A, Lai CSW, Chan YS, Shen X, Lai KO. The epilepsy and intellectual disability-associated protein TBC1D24 regulates the maintenance of excitatory synapses and animal behaviors. PLoS Genet 2020; 16:e1008587. [PMID: 32004315 PMCID: PMC7015432 DOI: 10.1371/journal.pgen.1008587] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 02/12/2020] [Accepted: 12/29/2019] [Indexed: 12/27/2022] Open
Abstract
Perturbation of synapse development underlies many inherited neurodevelopmental disorders including intellectual disability (ID). Diverse mutations on the human TBC1D24 gene are strongly associated with epilepsy and ID. However, the physiological function of TBC1D24 in the brain is not well understood, and there is a lack of genetic mouse model that mimics TBC1D24 loss-of-function for the study of animal behaviors. Here we report that TBC1D24 is present at the postsynaptic sites of excitatory synapses, where it is required for the maintenance of dendritic spines through inhibition of the small GTPase ARF6. Mice subjected to viral-mediated knockdown of TBC1D24 in the adult hippocampus display dendritic spine loss, deficits in contextual fear memory, as well as abnormal behaviors including hyperactivity and increased anxiety. Interestingly, we show that the protein stability of TBC1D24 is diminished by the disease-associated missense mutation that leads to F251L amino acid substitution. We further generate the F251L knock-in mice, and the homozygous mutants show increased neuronal excitability, spontaneous seizure and pre-mature death. Moreover, the heterozygous F251L knock-in mice survive into adulthood but display dendritic spine defects and impaired memory. Our findings therefore uncover a previously uncharacterized postsynaptic function of TBC1D24, and suggest that impaired dendritic spine maintenance contributes to the pathophysiology of individuals harboring TBC1D24 gene mutations. The F251L knock-in mice represent a useful animal model for investigation of the mechanistic link between TBC1D24 loss-of-function and neurodevelopmental disorders.
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Affiliation(s)
- Lianfeng Lin
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Quanwei Lyu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Pui-Yi Kwan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Junjun Zhao
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Ruolin Fan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Anping Chai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Cora Sau Wan Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Xuting Shen
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-On Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
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18
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Alteration of Phospholipase C Expression in Rat Visual Cortical Neurons by Chronic Blockade of Orexin Receptor 1. Int J Pept Res Ther 2019. [DOI: 10.1007/s10989-019-09943-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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19
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Reiner A, Levitz J. Glutamatergic Signaling in the Central Nervous System: Ionotropic and Metabotropic Receptors in Concert. Neuron 2019; 98:1080-1098. [PMID: 29953871 DOI: 10.1016/j.neuron.2018.05.018] [Citation(s) in RCA: 338] [Impact Index Per Article: 67.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/19/2018] [Accepted: 05/10/2018] [Indexed: 12/28/2022]
Abstract
Glutamate serves as both the mammalian brain's primary excitatory neurotransmitter and as a key neuromodulator to control synapse and circuit function over a wide range of spatial and temporal scales. This functional diversity is decoded by two receptor families: ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs). The challenges posed by the complexity and physiological importance of each of these subtypes has limited our appreciation and understanding of how these receptors work in concert. In this review, by comparing both receptor families with a focus on their crosstalk, we argue for a more holistic understanding of neural glutamate signaling.
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Affiliation(s)
- Andreas Reiner
- Department of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA.
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20
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Ren E, Roncacé V, Trazzi S, Fuchs C, Medici G, Gennaccaro L, Loi M, Galvani G, Ye K, Rimondini R, Aicardi G, Ciani E. Functional and Structural Impairments in the Perirhinal Cortex of a Mouse Model of CDKL5 Deficiency Disorder Are Rescued by a TrkB Agonist. Front Cell Neurosci 2019; 13:169. [PMID: 31114483 PMCID: PMC6503158 DOI: 10.3389/fncel.2019.00169] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/09/2019] [Indexed: 11/24/2022] Open
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a severe X-linked neurodevelopmental encephalopathy caused by mutations in the CDKL5 gene and characterized by early-onset epilepsy and intellectual and motor impairments. No cure is currently available for CDD patients, as limited knowledge of the pathology has hindered the development of therapeutics. Cdkl5 knockout (KO) mouse models, recently created to investigate the role of CDKL5 in the etiology of CDD, recapitulate various features of the disorder. Previous studies have shown alterations in synaptic plasticity and dendritic pattern in the cerebral cortex and in the hippocampus, but the knowledge of the molecular substrates underlying these alterations is still limited. Here, we have examined for the first time synaptic function and plasticity, dendritic morphology, and signal transduction pathways in the perirhinal cortex (PRC) of this mouse model. Being interconnected with a wide range of cortical and subcortical structures and involved in various cognitive processes, PRC provides a very interesting framework for examining how CDKL5 mutation leads to deficits at the synapse, circuit, and behavioral level. We found that long-term potentiation (LTP) was impaired, and that the TrkB/PLCγ1 pathway could be mechanistically involved in this alteration. PRC neurons in mutant mice showed a reduction in dendritic length, dendritic branches, PSD-95-positive puncta, GluA2-AMPA receptor levels, and spine density and maturation. These functional and structural deficits were associated with impairment in visual recognition memory. Interestingly, an in vivo treatment with a TrkB agonist (the 7,8-DHF prodrug R13) to trigger the TrkB/PLCγ1 pathway rescued defective LTP, dendritic pattern, PSD-95 and GluA2-AMPA receptor levels, and restored visual recognition memory in Cdkl5 KO mice. Present findings demonstrate a critical role of TrkB signaling in the synaptic development alterations due to CDKL5 mutation, and suggest the possibility of TrkB-targeted pharmacological interventions.
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Affiliation(s)
- Elisa Ren
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Vincenzo Roncacé
- Department for Life Quality Studies, University of Bologna, Bologna, Italy
| | - Stefania Trazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Claudia Fuchs
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giorgio Medici
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Laura Gennaccaro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Manuela Loi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giuseppe Galvani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Keqiang Ye
- School of Medicine, Emory University, Atlanta, GA, United States
| | - Roberto Rimondini
- Department of Biomedical and Clinical Sciences, University of Bologna, Bologna, Italy
| | - Giorgio Aicardi
- Department for Life Quality Studies, University of Bologna, Bologna, Italy.,Interdepartmental Center "Luigi Galvani" for Integrated Studies of Bioinformatics, Biophysics and Biocomplexity, University of Bologna, Bologna, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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21
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Suelves N, Miguez A, López-Benito S, Barriga GGD, Giralt A, Alvarez-Periel E, Arévalo JC, Alberch J, Ginés S, Brito V. Early Downregulation of p75 NTR by Genetic and Pharmacological Approaches Delays the Onset of Motor Deficits and Striatal Dysfunction in Huntington's Disease Mice. Mol Neurobiol 2019; 56:935-953. [PMID: 29804232 DOI: 10.1007/s12035-018-1126-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/11/2018] [Indexed: 11/26/2022]
Abstract
Deficits in striatal brain-derived neurotrophic factor (BDNF) delivery and/or BDNF/tropomyosin receptor kinase B (TrkB) signaling may contribute to neurotrophic support reduction and selective early degeneration of striatal medium spiny neurons in Huntington's disease (HD). Furthermore, we and others have demonstrated that TrkB/p75NTR imbalance in vitro increases the vulnerability of striatal neurons to excitotoxic insults and induces corticostriatal synaptic alterations. We have now expanded these studies by analyzing the consequences of BDNF/TrkB/p75NTR imbalance in the onset of motor behavior and striatal neuropathology in HD mice. Our findings demonstrate for the first time that the onset of motor coordination abnormalities, in a full-length knock-in HD mouse model (KI), correlates with the reduction of BDNF and TrkB levels, along with an increase in p75NTR expression. Genetic normalization of p75NTR expression in KI mutant mice delayed the onset of motor deficits and striatal neuropathology, as shown by restored levels of striatal-enriched proteins and dendritic spine density and reduced huntingtin aggregation. We found that the BDNF/TrkB/p75NTR imbalance led to abnormal BDNF signaling, manifested as a diminished activation of TrkB-phospholipase C-gamma pathway but upregulation of c-Jun kinase pathway. Moreover, we confirmed the contribution of the proper balance of BDNF/TrkB/p75NTR on HD pathology by a pharmacological approach using fingolimod. We observed that chronic infusion of fingolimod normalizes p75NTR levels, which is likely to improve motor coordination and striatal neuropathology in HD transgenic mice. We conclude that downregulation of p75NTR expression can delay disease progression suggesting that therapeutic approaches aimed to restore the balance between BDNF, TrkB, and p75NTR could be promising to prevent motor deficits in HD.
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Affiliation(s)
- Nuria Suelves
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Andrés Miguez
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Saray López-Benito
- Department of Cell Biology and Pathology, Instituto de Neurociencias de Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
| | - Gerardo García-Díaz Barriga
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Albert Giralt
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Elena Alvarez-Periel
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Juan Carlos Arévalo
- Department of Cell Biology and Pathology, Instituto de Neurociencias de Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
| | - Jordi Alberch
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Silvia Ginés
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Verónica Brito
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Barcelona, Spain.
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
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Hackelberg S, Oliver D. Metabotropic Acetylcholine and Glutamate Receptors Mediate PI(4,5)P 2 Depletion and Oscillations in Hippocampal CA1 Pyramidal Neurons in situ. Sci Rep 2018; 8:12987. [PMID: 30154490 PMCID: PMC6113233 DOI: 10.1038/s41598-018-31322-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/17/2018] [Indexed: 01/24/2023] Open
Abstract
The sensitivity of many ion channels to phosphatidylinositol-4,5-bisphosphate (PIP2) levels in the cell membrane suggests that PIP2 fluctuations are important and general signals modulating neuronal excitability. Yet the PIP2 dynamics of central neurons in their native environment remained largely unexplored. Here, we examined the behavior of PIP2 concentrations in response to activation of Gq-coupled neurotransmitter receptors in rat CA1 hippocampal neurons in situ in acute brain slices. Confocal microscopy of the PIP2-selective molecular sensors tubbyCT-GFP and PLCδ1-PH-GFP showed that pharmacological activation of muscarinic acetylcholine (mAChR) or group I metabotropic glutamate (mGluRI) receptors induces transient depletion of PIP2 in the soma as well as in the dendritic tree. The observed PIP2 dynamics were receptor-specific, with mAChR activation inducing stronger PIP2 depletion than mGluRI, whereas agonists of other Gαq-coupled receptors expressed in CA1 neurons did not induce measureable PIP2 depletion. Furthermore, the data show for the first time neuronal receptor-induced oscillations of membrane PIP2 concentrations. Oscillatory behavior indicated that neurons can rapidly restore PIP2 levels during persistent activation of Gq and PLC. Electrophysiological responses to receptor activation resembled PIP2 dynamics in terms of time course and receptor specificity. Our findings support a physiological function of PIP2 in regulating electrical activity.
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Affiliation(s)
- Sandra Hackelberg
- Institute of Physiology and Pathophysiology, Philipps University, 35037, Marburg, Germany
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Dominik Oliver
- Institute of Physiology and Pathophysiology, Philipps University, 35037, Marburg, Germany.
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps University, Marburg, Germany.
- Center for Mind, Brain and Behavior (CMBB), Marburg and Giessen, Germany.
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23
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De Franceschi N, Alqabandi M, Miguet N, Caillat C, Mangenot S, Weissenhorn W, Bassereau P. The ESCRT protein CHMP2B acts as a diffusion barrier on reconstituted membrane necks. J Cell Sci 2018; 132:jcs.217968. [PMID: 29967034 DOI: 10.1242/jcs.217968] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/25/2018] [Indexed: 01/23/2023] Open
Abstract
Endosomal sorting complexes required for transport (ESCRT)-III family proteins catalyze membrane remodeling processes that stabilize and constrict membrane structures. It has been proposed that stable ESCRT-III complexes containing CHMP2B could establish diffusion barriers at the post-synaptic spine neck. In order to better understand this process, we developed a novel method based on fusion of giant unilamellar vesicles to reconstitute ESCRT-III proteins inside GUVs, from which membrane nanotubes are pulled. The new assay ensures that ESCRT-III proteins polymerize only when they become exposed to physiologically relevant membrane topology mimicking the complex geometry of post-synaptic spines. We establish that CHMP2B, both full-length and with a C-terminal deletion (ΔC), preferentially binds to membranes containing phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. Moreover, we show that CHMP2B preferentially accumulates at the neck of membrane nanotubes, and provide evidence that CHMP2B-ΔC prevents the diffusion of PI(4,5)P2 lipids and membrane-bound proteins across the tube neck. This indicates that CHMP2B polymers formed at a membrane neck may function as a diffusion barrier, highlighting a potential important function of CHMP2B in maintaining synaptic spine structures.
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Affiliation(s)
- Nicola De Franceschi
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005, Paris, France
| | - Maryam Alqabandi
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005, Paris, France
| | - Nolwenn Miguet
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71, avenue des Martyrs, 38000 Grenoble, France
| | - Christophe Caillat
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71, avenue des Martyrs, 38000 Grenoble, France
| | - Stephanie Mangenot
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France.,Sorbonne Université, 75005, Paris, France
| | - Winfried Weissenhorn
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71, avenue des Martyrs, 38000 Grenoble, France
| | - Patricia Bassereau
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France .,Sorbonne Université, 75005, Paris, France
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Marballi KK, Gallitano AL. Immediate Early Genes Anchor a Biological Pathway of Proteins Required for Memory Formation, Long-Term Depression and Risk for Schizophrenia. Front Behav Neurosci 2018; 12:23. [PMID: 29520222 PMCID: PMC5827560 DOI: 10.3389/fnbeh.2018.00023] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/29/2018] [Indexed: 01/02/2023] Open
Abstract
While the causes of myriad medical and infectious illnesses have been identified, the etiologies of neuropsychiatric illnesses remain elusive. This is due to two major obstacles. First, the risk for neuropsychiatric disorders, such as schizophrenia, is determined by both genetic and environmental factors. Second, numerous genes influence susceptibility for these illnesses. Genome-wide association studies have identified at least 108 genomic loci for schizophrenia, and more are expected to be published shortly. In addition, numerous biological processes contribute to the neuropathology underlying schizophrenia. These include immune dysfunction, synaptic and myelination deficits, vascular abnormalities, growth factor disruption, and N-methyl-D-aspartate receptor (NMDAR) hypofunction. However, the field of psychiatric genetics lacks a unifying model to explain how environment may interact with numerous genes to influence these various biological processes and cause schizophrenia. Here we describe a biological cascade of proteins that are activated in response to environmental stimuli such as stress, a schizophrenia risk factor. The central proteins in this pathway are critical mediators of memory formation and a particular form of hippocampal synaptic plasticity, long-term depression (LTD). Each of these proteins is also implicated in schizophrenia risk. In fact, the pathway includes four genes that map to the 108 loci associated with schizophrenia: GRIN2A, nuclear factor of activated T-cells (NFATc3), early growth response 1 (EGR1) and NGFI-A Binding Protein 2 (NAB2); each of which contains the "Index single nucleotide polymorphism (SNP)" (most SNP) at its respective locus. Environmental stimuli activate this biological pathway in neurons, resulting in induction of EGR immediate early genes: EGR1, EGR3 and NAB2. We hypothesize that dysfunction in any of the genes in this pathway disrupts the normal activation of Egrs in response to stress. This may result in insufficient electrophysiologic, immunologic, and neuroprotective, processes that these genes normally mediate. Continued adverse environmental experiences, over time, may thereby result in neuropathology that gives rise to the symptoms of schizophrenia. By combining multiple genes associated with schizophrenia susceptibility, in a functional cascade triggered by neuronal activity, the proposed biological pathway provides an explanation for both the polygenic and environmental influences that determine the complex etiology of this mental illness.
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Affiliation(s)
- Ketan K. Marballi
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, United States
| | - Amelia L. Gallitano
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, United States
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Control of Homeostatic Synaptic Plasticity by AKAP-Anchored Kinase and Phosphatase Regulation of Ca 2+-Permeable AMPA Receptors. J Neurosci 2018; 38:2863-2876. [PMID: 29440558 DOI: 10.1523/jneurosci.2362-17.2018] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/17/2018] [Accepted: 02/06/2018] [Indexed: 12/31/2022] Open
Abstract
Neuronal information processing requires multiple forms of synaptic plasticity mediated by NMDARs and AMPA-type glutamate receptors (AMPARs). These plasticity mechanisms include long-term potentiation (LTP) and long-term depression (LTD), which are Hebbian, homosynaptic mechanisms locally regulating synaptic strength of specific inputs, and homeostatic synaptic scaling, which is a heterosynaptic mechanism globally regulating synaptic strength across all inputs. In many cases, LTP and homeostatic scaling regulate AMPAR subunit composition to increase synaptic strength via incorporation of Ca2+-permeable receptors (CP-AMPAR) containing GluA1, but lacking GluA2, subunits. Previous work by our group and others demonstrated that anchoring of the kinase PKA and the phosphatase calcineurin (CaN) to A-kinase anchoring protein (AKAP) 150 play opposing roles in regulation of GluA1 Ser845 phosphorylation and CP-AMPAR synaptic incorporation during hippocampal LTP and LTD. Here, using both male and female knock-in mice that are deficient in PKA or CaN anchoring, we show that AKAP150-anchored PKA and CaN also play novel roles in controlling CP-AMPAR synaptic incorporation during homeostatic plasticity in hippocampal neurons. We found that genetic disruption of AKAP-PKA anchoring prevented increases in Ser845 phosphorylation and CP-AMPAR synaptic recruitment during rapid homeostatic synaptic scaling-up induced by combined blockade of action potential firing and NMDAR activity. In contrast, genetic disruption of AKAP-CaN anchoring resulted in basal increases in Ser845 phosphorylation and CP-AMPAR synaptic activity that blocked subsequent scaling-up by preventing additional CP-AMPAR recruitment. Thus, the balanced, opposing phospho-regulation provided by AKAP-anchored PKA and CaN is essential for control of both Hebbian and homeostatic plasticity mechanisms that require CP-AMPARs.SIGNIFICANCE STATEMENT Neuronal circuit function is shaped by multiple forms of activity-dependent plasticity that control excitatory synaptic strength, including LTP/LTD that adjusts strength of individual synapses and homeostatic plasticity that adjusts overall strength of all synapses. Mechanisms controlling LTP/LTD and homeostatic plasticity were originally thought to be distinct; however, recent studies suggest that CP-AMPAR phosphorylation regulation is important during both LTP/LTD and homeostatic plasticity. Here we show that CP-AMPAR regulation by the kinase PKA and phosphatase CaN coanchored to the scaffold protein AKAP150, a mechanism previously implicated in LTP/LTD, is also crucial for controlling synaptic strength during homeostatic plasticity. These novel findings significantly expand our understanding of homeostatic plasticity mechanisms and further emphasize how intertwined they are with LTP and LTD.
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Wild AR, Dell'Acqua ML. Potential for therapeutic targeting of AKAP signaling complexes in nervous system disorders. Pharmacol Ther 2017; 185:99-121. [PMID: 29262295 DOI: 10.1016/j.pharmthera.2017.12.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A common feature of neurological and neuropsychiatric disorders is a breakdown in the integrity of intracellular signal transduction pathways. Dysregulation of ion channels and receptors in the cell membrane and the enzymatic mediators that link them to intracellular effectors can lead to synaptic dysfunction and neuronal death. However, therapeutic targeting of these ubiquitous signaling elements can lead to off-target side effects due to their widespread expression in multiple systems of the body. A-kinase anchoring proteins (AKAPs) are multivalent scaffolding proteins that compartmentalize a diverse range of receptor and effector proteins to streamline signaling within nanodomain signalosomes. A number of essential neurological processes are known to critically depend on AKAP-directed signaling and an understanding of the role AKAPs play in nervous system disorders has emerged in recent years. Selective targeting of AKAP protein-protein interactions may be a means to uncouple pathologically active signaling pathways in neurological disorders with a greater degree of specificity. In this review we will discuss the role of AKAPs in both regulating normal nervous system function and dysfunction associated with disease, and the potential for therapeutic targeting of AKAP signaling complexes.
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Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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27
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Woolfrey KM, O'Leary H, Goodell DJ, Robertson HR, Horne EA, Coultrap SJ, Dell'Acqua ML, Bayer KU. CaMKII regulates the depalmitoylation and synaptic removal of the scaffold protein AKAP79/150 to mediate structural long-term depression. J Biol Chem 2017; 293:1551-1567. [PMID: 29196604 DOI: 10.1074/jbc.m117.813808] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/21/2017] [Indexed: 11/06/2022] Open
Abstract
Both long-term potentiation (LTP) and depression (LTD) of excitatory synapse strength require the Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) and its autonomous activity generated by Thr-286 autophosphorylation. Additionally, LTP and LTD are correlated with dendritic spine enlargement and shrinkage that are accompanied by the synaptic accumulation or removal, respectively, of the AMPA-receptor regulatory scaffold protein A-kinase anchoring protein (AKAP) 79/150. We show here that the spine shrinkage associated with LTD indeed requires synaptic AKAP79/150 removal, which in turn requires CaMKII activity. In contrast to normal CaMKII substrates, the substrate sites within the AKAP79/150 N-terminal polybasic membrane-cytoskeletal targeting domain were phosphorylated more efficiently by autonomous compared with Ca2+/CaM-stimulated CaMKII activity. This unusual regulation was mediated by Ca2+/CaM binding to the substrate sites resulting in protection from phosphorylation in the presence of Ca2+/CaM, a mechanism that favors phosphorylation by prolonged, weak LTD stimuli versus brief, strong LTP stimuli. Phosphorylation by CaMKII inhibited AKAP79/150 association with F-actin; it also facilitated AKAP79/150 removal from spines but was not required for it. By contrast, LTD-induced spine removal of AKAP79/150 required its depalmitoylation on two Cys residues within the N-terminal targeting domain. Notably, such LTD-induced depalmitoylation was also blocked by CaMKII inhibition. These results provide a mechanism how CaMKII can indeed mediate not only LTP but also LTD through regulated substrate selection; however, in the case of AKAP79/150, indirect CaMKII effects on palmitoylation are more important than the effects of direct phosphorylation. Additionally, our results provide the first direct evidence for a function of the well-described AKAP79/150 trafficking in regulating LTD-induced spine shrinkage.
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Affiliation(s)
- Kevin M Woolfrey
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Heather O'Leary
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Dayton J Goodell
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Holly R Robertson
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Eric A Horne
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Steven J Coultrap
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Mark L Dell'Acqua
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - K Ulrich Bayer
- From the Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
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28
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Rich MT, Torregrossa MM. Molecular and synaptic mechanisms regulating drug-associated memories: Towards a bidirectional treatment strategy. Brain Res Bull 2017; 141:58-71. [PMID: 28916448 DOI: 10.1016/j.brainresbull.2017.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/21/2017] [Accepted: 09/05/2017] [Indexed: 12/11/2022]
Abstract
The successful treatment of substance use disorders is dependent on the establishment of a long-term abstinent state. Relapse can be suppressed by interfering with memories of drug use that are evoked by re-exposure to drug-associated contexts and cues. Two strategies for accomplishing this goal are either to prevent drug-memory reconsolidation or to induce the formation of a competing, extinction memory. However, clinical attempts to prolong abstinence by behavioral modification of drug-related memories have had limited success. One approach to improve behavioral treatment strategies is to identify the molecular mechanisms that regulate these memory processes and then use pharmacological tools as supplements to improve efficacy. Still, due to the involvement of several overlapping signaling cascades in both reconsolidation and extinction, it is difficult to specifically modify one of the two processes. For example, attempting to elicit extinction may instead initiate reconsolidation, resulting in the unintentional strengthening of drug-related memories. A better approach is to identify diverging components of the two processes, whereby a single medication would simultaneously weaken reconsolidation and enhance extinction. This review will provide an overview of the neural substrates that are involved in the regulation of drug-associated memories, and will discuss emerging approaches to pharmacologically weaken these memories, including recent efforts to precisely and bidirectionally target reconsolidation and extinction. Ultimately, pharmacologically-enhanced memory-based approaches have the potential to produce more informed relapse-prevention therapies.
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Affiliation(s)
- Matthew T Rich
- Department of Psychiatry, University of Pittsburgh, 3811 O'Hara St., Pittsburgh, PA 15213, United States; Center for Neuroscience, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15213, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, 4400 Fifth Ave, Pittsburgh, PA, 15213, United States.
| | - Mary M Torregrossa
- Center for Neuroscience, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15213, United States.
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29
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Identification of postsynaptic phosphatidylinositol-4,5-bisphosphate (PIP 2) roles for synaptic plasticity using chemically induced dimerization. Sci Rep 2017; 7:3351. [PMID: 28611378 PMCID: PMC5469801 DOI: 10.1038/s41598-017-03520-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 05/02/2017] [Indexed: 11/16/2022] Open
Abstract
Phosphatidylinositol-4,5-bisphosphate (PIP2), one of the key phospholipids, directly interacts with several membrane and cytosolic proteins at neuronal plasma membranes, leading to changes in neuronal properties including the feature and surface expression of ionotropic receptors. Although PIP2 is also concentrated at the dendritic spines, little is known about the direct physiological functions of PIP2 at postsynaptic as opposed to presynaptic sites. Most previous studies used genetic and pharmacological methods to modulate enzymes that alter PIP2 levels, making it difficult to delineate time- or region-specific roles of PIP2. We used chemically-induced dimerization to translocate inositol polyphosphate 5-phosphatase (Inp54p) to plasma membranes in the presence of rapamycin. Upon redistribution of Inp54p, long-term depression (LTD) induced by low-frequency stimulation was blocked in the mouse hippocampal CA3-CA1 pathway, but the catalytically-dead mutant did not affect LTD induction. Collectively, PIP2 is critically required for induction of LTD whereas translocation of Inp54p to plasma membranes has no effect on the intrinsic properties of the neurons, basal synaptic transmission, long-term potentiation or expression of LTD.
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Receptor-stimulated transamidation induces activation of Rac1 and Cdc42 and the regulation of dendritic spines. Neuropharmacology 2017; 117:93-105. [PMID: 28161375 DOI: 10.1016/j.neuropharm.2017.01.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/26/2017] [Accepted: 01/29/2017] [Indexed: 11/21/2022]
Abstract
Regulation of dendritic spines is an important component of synaptic function and plasticity whereas dendritic spine dysregulation is related to several psychiatric and neurological diseases. In the present study, we tested the hypothesis that serotonin (5-HT)2A/2C receptor-induced Rho family transamidation and activation regulates dendritic spine morphology and that activation of multiple types of receptors can induce transglutaminase (TGase)-catalyzed transamidation of small G proteins. We previously reported a novel 5-HT2A receptor downstream effector, TGase-catalyzed serotonylation of the small G protein Rac1 in A1A1v cells, a rat embryonic cortical cell line. We now extend these findings to rat primary cortical cultures which develop dendritic spines; stimulation of 5-HT2A/2C receptors increased transamidation of Rac1 and Cdc42, but not RhoA. Inhibition of TGases significantly decreased transamidation and activation of Rac1 and Cdc42, suggesting that transamidation led to their activation. In primary cortical cultures, stimulation of 5-HT2A/2C receptors by 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) caused a transient dendritic spine enlargement, which was blocked by TGase inhibition. Stimulation of both 5-HT2A and 5-HT2C receptors contributed to DOI-induced Rac1 transamidation in primary cortical cultures as demonstrated by selective antagonists. Furthermore, stimulation of muscarinic acetylcholine receptors and NMDA receptors also increased TGase-catalyzed Rac1 activation in SH-SY5Y cells and N2a cells, respectively. Receptor-stimulated TGase-catalyzed transamidation of Rac1 occurs at Q61, a site previously reported to be important in the inactivation of Rac1. These studies demonstrate that TGase-catalyzed transamidation and activation of small G proteins results from stimulation of multiple types of receptors and this novel signaling pathway can regulate dendritic spine morphology and plasticity.
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31
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Tabet R, Vitale N, Moine H. Fragile X syndrome: Are signaling lipids the missing culprits? Biochimie 2016; 130:188-194. [PMID: 27597551 DOI: 10.1016/j.biochi.2016.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/01/2016] [Indexed: 10/21/2022]
Abstract
Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and autism. FXS results from the absence of FMRP, an RNA binding protein associated to ribosomes that influences the translation of specific mRNAs in post-synaptic compartments of neurons. The main molecular consequence of the absence of FMRP is an excessive translation of neuronal protein in several areas of the brain. This local protein synthesis deregulation is proposed to underlie the defect in synaptic plasticity responsible for FXS. Recent findings in neurons of the fragile X mouse model (Fmr1-KO) uncovered another consequence of the lack of FMRP: a deregulation of the diacylglycerol (DAG)/phosphatidic acid (PA) homeostasis. DAG and PA are two interconvertible lipids that influence membrane architecture and that act as essential signaling molecules that activate various downstream effectors, including master regulators of local protein synthesis and actin polymerization. As a consequence, DAG and PA govern a variety of cellular processes, including cell proliferation, vesicle/membrane trafficking and cytoskeletal organization. At the synapse, the level of these lipids is proposed to influence the synaptic activation status. FMRP appears as a master regulator of this neuronal process by controlling the translation of a diacylglycerol kinase enzyme that converts DAG into PA. The deregulated levels of DAG and PA caused by the absence of FMRP could represent a novel therapeutic target for the treatment of FXS.
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Affiliation(s)
- Ricardos Tabet
- Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 CNRS, Université de Strasbourg, 67084 Strasbourg, France
| | - Hervé Moine
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Université de Strasbourg, 67084 Strasbourg, France.
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32
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Wong H, Levenga J, Cain P, Rothermel B, Klann E, Hoeffer C. RCAN1 overexpression promotes age-dependent mitochondrial dysregulation related to neurodegeneration in Alzheimer's disease. Acta Neuropathol 2015; 130:829-43. [PMID: 26497675 DOI: 10.1007/s00401-015-1499-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 10/22/2022]
Abstract
Aging is the largest risk factor for Alzheimer's disease (AD). Patients with Down syndrome (DS) develop symptoms consistent with early-onset AD, suggesting that overexpression of chromosome 21 genes such as Regulator of Calcineurin 1 (RCAN1) plays a role in AD pathogenesis. RCAN1 levels are increased in the brain of DS and AD patients but also in the human brain with normal aging. RCAN1 has been implicated in several neuronal functions, but whether its increased expression is correlative or causal in the aging-related progression of AD remains elusive. We show that brain-specific overexpression of the human RCAN1.1S isoform in mice promotes early age-dependent memory and synaptic plasticity deficits, tau pathology, and dysregulation of dynamin-related protein 1 (DRP1) activity associated with mitochondrial dysfunction and oxidative stress, reproducing key AD features. Based on these findings, we propose that chronic RCAN1 overexpression during aging alters DRP1-mediated mitochondrial fission and thus acts to promote AD-related progressive neurodegeneration.
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Affiliation(s)
- Helen Wong
- Center for Neural Science, New York University, New York, NY, USA
| | - Josien Levenga
- Department of Integrated of Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, CO, USA
| | - Peter Cain
- Department of Integrated of Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, CO, USA
| | - Beverly Rothermel
- Department of Cardiology, University of Texas-Southwestern, Dallas, TX, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY, USA
| | - Charles Hoeffer
- Department of Integrated of Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, CO, USA.
- New York University School of Medicine, New York, NY, USA.
- Linda Crnic Institute, Denver, CO, USA.
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33
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Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach. Eur J Cell Biol 2015; 94:401-14. [DOI: 10.1016/j.ejcb.2015.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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34
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MIM-Induced Membrane Bending Promotes Dendritic Spine Initiation. Dev Cell 2015; 33:644-59. [PMID: 26051541 DOI: 10.1016/j.devcel.2015.04.014] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/28/2015] [Accepted: 04/21/2015] [Indexed: 11/21/2022]
Abstract
Proper morphogenesis of neuronal dendritic spines is essential for the formation of functional synaptic networks. However, it is not known how spines are initiated. Here, we identify the inverse-BAR (I-BAR) protein MIM/MTSS1 as a nucleator of dendritic spines. MIM accumulated to future spine initiation sites in a PIP2-dependent manner and deformed the plasma membrane outward into a proto-protrusion via its I-BAR domain. Unexpectedly, the initial protrusion formation did not involve actin polymerization. However, PIP2-dependent activation of Arp2/3-mediated actin assembly was required for protrusion elongation. Overexpression of MIM increased the density of dendritic protrusions and suppressed spine maturation. In contrast, MIM deficiency led to decreased density of dendritic protrusions and larger spine heads. Moreover, MIM-deficient mice displayed altered glutamatergic synaptic transmission and compatible behavioral defects. Collectively, our data identify an important morphogenetic pathway, which initiates spine protrusions by coupling phosphoinositide signaling, direct membrane bending, and actin assembly to ensure proper synaptogenesis.
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35
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The palmitoyl acyltransferase DHHC2 regulates recycling endosome exocytosis and synaptic potentiation through palmitoylation of AKAP79/150. J Neurosci 2015; 35:442-56. [PMID: 25589740 DOI: 10.1523/jneurosci.2243-14.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Phosphorylation and dephosphorylation of AMPA-type ionotropic glutamate receptors (AMPARs) by kinases and phosphatases and interactions with scaffold proteins play essential roles in regulating channel biophysical properties and trafficking events that control synaptic strength during NMDA receptor-dependent synaptic plasticity, such as LTP and LTD. We previously demonstrated that palmitoylation of the AMPAR-linked scaffold protein A-kinase anchoring protein (AKAP) 79/150 is required for its targeting to recycling endosomes in dendrites, where it regulates exocytosis from these compartments that is required for LTP-stimulated enlargement of postsynaptic dendritic spines, delivery of AMPARs to the plasma membrane, and maintenance of synaptic potentiation. Here, we report that the recycling endosome-resident palmitoyl acyltransferase DHHC2 interacts with and palmitoylates AKAP79/150 to regulate these plasticity signaling mechanisms. In particular, RNAi-mediated knockdown of DHHC2 expression in rat hippocampal neurons disrupted stimulation of exocytosis from recycling endosomes, enlargement of dendritic spines, AKAP recruitment to spines, and potentiation of AMPAR-mediated synaptic currents that occur during LTP. Importantly, expression of a palmitoylation-independent lipidated AKAP mutant in DHHC2-deficient neurons largely restored normal plasticity regulation. Thus, we conclude that DHHC2-AKAP79/150 signaling is an essential regulator of dendritic recycling endosome exocytosis that controls both structural and functional plasticity at excitatory synapses.
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36
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Martin MG, Ahmed T, Korovaichuk A, Venero C, Menchón SA, Salas I, Munck S, Herreras O, Balschun D, Dotti CG. Constitutive hippocampal cholesterol loss underlies poor cognition in old rodents. EMBO Mol Med 2015; 6:902-17. [PMID: 24878762 PMCID: PMC4119354 DOI: 10.15252/emmm.201303711] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cognitive decline is one of the many characteristics of aging. Reduced long-term potentiation (LTP) and long-term depression (LTD) are thought to be responsible for this decline, although the precise mechanisms underlying LTP and LTD dampening in the old remain unclear. We previously showed that aging is accompanied by the loss of cholesterol from the hippocampus, which leads to PI3K/Akt phosphorylation. Given that Akt de-phosphorylation is required for glutamate receptor internalization and LTD, we hypothesized that the decrease in cholesterol in neuronal membranes may contribute to the deficits in LTD typical of aging. Here, we show that cholesterol loss triggers p-Akt accumulation, which in turn perturbs the normal cellular and molecular responses induced by LTD, such as impaired AMPA receptor internalization and its reduced lateral diffusion. Electrophysiology recordings in brain slices of old mice and in anesthetized elderly rats demonstrate that the reduced hippocampal LTD associated with age can be rescued by cholesterol perfusion. Accordingly, cholesterol replenishment in aging animals improves hippocampal-dependent learning and memory in the water maze test.
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Affiliation(s)
- Mauricio G Martin
- Centro Biología Molecular "Severo Ochoa" CSIC-UAM, Madrid, Spain VIB Center for the Biology of Disease, Center for Human Genetics, University of Leuven (KU Leuven), Leuven, Belgium
| | - Tariq Ahmed
- Laboratory of Biological Psychology, Faculty of Psychology and Educational Sciences, University of Leuven (KU Leuven), Leuven, Belgium
| | - Alejandra Korovaichuk
- Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal - CSIC, Madrid, Spain
| | - Cesar Venero
- Departamento de Psicobiología, Facultad de Psicología, UNED, Madrid, Spain
| | - Silvia A Menchón
- VIB Center for the Biology of Disease, Center for Human Genetics, University of Leuven (KU Leuven), Leuven, Belgium IFEG-CONICET and FaMAF, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Isabel Salas
- Centro Biología Molecular "Severo Ochoa" CSIC-UAM, Madrid, Spain
| | - Sebastian Munck
- VIB Center for the Biology of Disease, Center for Human Genetics, University of Leuven (KU Leuven), Leuven, Belgium
| | - Oscar Herreras
- Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal - CSIC, Madrid, Spain
| | - Detlef Balschun
- Laboratory of Biological Psychology, Faculty of Psychology and Educational Sciences, University of Leuven (KU Leuven), Leuven, Belgium
| | - Carlos G Dotti
- Centro Biología Molecular "Severo Ochoa" CSIC-UAM, Madrid, Spain VIB Center for the Biology of Disease, Center for Human Genetics, University of Leuven (KU Leuven), Leuven, Belgium
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A Septin-Dependent Diffusion Barrier at Dendritic Spine Necks. PLoS One 2014; 9:e113916. [PMID: 25494357 PMCID: PMC4262254 DOI: 10.1371/journal.pone.0113916] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 11/02/2014] [Indexed: 01/10/2023] Open
Abstract
Excitatory glutamatergic synapses at dendritic spines exchange and modulate their receptor content via lateral membrane diffusion. Several studies have shown that the thin spine neck impedes the access of membrane and solute molecules to the spine head. However, it is unclear whether the spine neck geometry alone restricts access to dendritic spines or if a physical barrier to the diffusion of molecules exists. Here, we investigated whether a complex of septin cytoskeletal GTPases localized at the base of the spine neck regulates diffusion across the spine neck. We found that, during development, a marker of the septin complex, Septin7 (Sept7), becomes localized to the spine neck where it forms a stable structure underneath the plasma membrane. We show that diffusion of receptors and bulk membrane, but not cytoplasmic proteins, is slower in spines bearing Sept7 at their neck. Finally, when Sept7 expression was suppressed by RNA interference, membrane molecules explored larger membrane areas. Our findings indicate that Sept7 regulates membrane protein access to spines.
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Activity-dependent PI(3,5)P2 synthesis controls AMPA receptor trafficking during synaptic depression. Proc Natl Acad Sci U S A 2014; 111:E4896-905. [PMID: 25355904 DOI: 10.1073/pnas.1411117111] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Dynamic regulation of phosphoinositide lipids (PIPs) is crucial for diverse cellular functions, and, in neurons, PIPs regulate membrane trafficking events that control synapse function. Neurons are particularly sensitive to the levels of the low abundant PIP, phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2], because mutations in PI(3,5)P2-related genes are implicated in multiple neurological disorders, including epilepsy, severe neuropathy, and neurodegeneration. Despite the importance of PI(3,5)P2 for neural function, surprisingly little is known about this signaling lipid in neurons, or any cell type. Notably, the mammalian homolog of yeast vacuole segregation mutant (Vac14), a scaffold for the PI(3,5)P2 synthesis complex, is concentrated at excitatory synapses, suggesting a potential role for PI(3,5)P2 in controlling synapse function and/or plasticity. PI(3,5)P2 is generated from phosphatidylinositol 3-phosphate (PI3P) by the lipid kinase PI3P 5-kinase (PIKfyve). Here, we present methods to measure and control PI(3,5)P2 synthesis in hippocampal neurons and show that changes in neural activity dynamically regulate the levels of multiple PIPs, with PI(3,5)P2 being among the most dynamic. The levels of PI(3,5)P2 in neurons increased during two distinct forms of synaptic depression, and inhibition of PIKfyve activity prevented or reversed induction of synaptic weakening. Moreover, altering neuronal PI(3,5)P2 levels was sufficient to regulate synaptic strength bidirectionally, with enhanced synaptic function accompanying loss of PI(3,5)P2 and reduced synaptic strength following increased PI(3,5)P2 levels. Finally, inhibiting PI(3,5)P2 synthesis alters endocytosis and recycling of AMPA-type glutamate receptors (AMPARs), implicating PI(3,5)P2 dynamics in AMPAR trafficking. Together, these data identify PI(3,5)P2-dependent signaling as a regulatory pathway that is critical for activity-dependent changes in synapse strength.
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39
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Dotti CG, Esteban JA, Ledesma MD. Lipid dynamics at dendritic spines. Front Neuroanat 2014; 8:76. [PMID: 25152717 PMCID: PMC4126552 DOI: 10.3389/fnana.2014.00076] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/21/2014] [Indexed: 11/13/2022] Open
Abstract
Dynamic changes in the structure and composition of the membrane protrusions forming dendritic spines underlie memory and learning processes. In recent years a great effort has been made to characterize in detail the protein machinery that controls spine plasticity. However, we know much less about the involvement of lipids, despite being major membrane components and structure determinants. Moreover, protein complexes that regulate spine plasticity depend on specific interactions with membrane lipids for proper function and accurate intracellular signaling. In this review we gather information available on the lipid composition at dendritic spine membranes and on its dynamics. We pay particular attention to the influence that spine lipid dynamism has on glutamate receptors, which are key regulators of synaptic plasticity.
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40
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Coiro P, Stoenica L, Strauss U, Bräuer AU. Plasticity-related gene 5 promotes spine formation in murine hippocampal neurons. J Biol Chem 2014; 289:24956-70. [PMID: 25074937 DOI: 10.1074/jbc.m114.597880] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transmembrane protein plasticity-related genes 3 and 5 (PRG3 and PRG5) increase filopodial formation in various cell lines, independently of Cdc42. However, information on the effects of PRG5 during neuronal development is sparse. Here, we present several lines of evidence for the involvement of PRG5 in the genesis and stabilization of dendritic spines. First, PRG5 was strongly expressed during mouse brain development from embryonic day 14 (E14), peaked around the time of birth, and remained stable at least until early adult stages (i.e. P30). Second, on a subcellular level, PRG5 expression shifted from an equal distribution along all neurites toward accumulation only along dendrites during hippocampal development in vitro. Third, overexpression of PRG5 in immature hippocampal neurons induced formation of spine-like structures ahead of time. Proper amino acid sequences in the extracellular domains (D1 to D3) of PRG5 were a prerequisite for trafficking and induction of spine-like structures, as shown by mutation analysis. Fourth, at stages when spines are present, knockdown of PRG5 reduced the number but not the length of protrusions. This was accompanied by a decrease in the number of excitatory synapses and, consequently, by a reduction of miniature excitatory postsynaptic current frequencies, although miniature excitatory postsynaptic current amplitudes remained similar. In turn, overexpressing PRG5 in mature neurons not only increased Homer-positive spine numbers but also augmented spine head diameters. Mechanistically, PRG5 interacts with phosphorylated phosphatidylinositols, phospholipids involved in dendritic spine formation by different lipid-protein assays. Taken together, our data propose that PRG5 promotes spine formation.
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Affiliation(s)
- Pierluca Coiro
- From the Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Luminita Stoenica
- From the Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Ulf Strauss
- From the Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Anja Ursula Bräuer
- From the Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
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41
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Ueda Y. The Role of Phosphoinositides in Synapse Function. Mol Neurobiol 2014; 50:821-38. [DOI: 10.1007/s12035-014-8768-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 06/01/2014] [Indexed: 11/30/2022]
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42
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He Y, Kulasiri D, Samarasinghe S. Systems biology of synaptic plasticity: a review on N-methyl-D-aspartate receptor mediated biochemical pathways and related mathematical models. Biosystems 2014; 122:7-18. [PMID: 24929130 DOI: 10.1016/j.biosystems.2014.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 10/25/2022]
Abstract
Synaptic plasticity, an emergent property of synaptic networks, has shown strong correlation to one of the essential functions of the brain, memory formation. Through understanding synaptic plasticity, we hope to discover the modulators and mechanisms that trigger memory formation. In this paper, we first review the well understood modulators and mechanisms underlying N-methyl-D-aspartate receptor dependent synaptic plasticity, a major form of synaptic plasticity in hippocampus, and then comment on the key mathematical modelling approaches available in the literature to understand synaptic plasticity as the integration of the established functionalities of synaptic components.
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Affiliation(s)
- Y He
- Centre for Advanced Computational Solutions (C-fACS), Molecular Biosciences Department, Lincoln University, Christchurch, New Zealand
| | - D Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Molecular Biosciences Department, Lincoln University, Christchurch, New Zealand.
| | - S Samarasinghe
- Centre for Advanced Computational Solutions (C-fACS), Molecular Biosciences Department, Lincoln University, Christchurch, New Zealand
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43
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M1-muscarinic receptors promote fear memory consolidation via phospholipase C and the M-current. J Neurosci 2014; 34:1570-8. [PMID: 24478341 DOI: 10.1523/jneurosci.1040-13.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Neuromodulators released during and after a fearful experience promote the consolidation of long-term memory for that experience. Because overconsolidation may contribute to the recurrent and intrusive memories of post-traumatic stress disorder, neuromodulatory receptors provide a potential pharmacological target for prevention. Stimulation of muscarinic receptors promotes memory consolidation in several conditioning paradigms, an effect primarily associated with the M1 receptor (M1R). However, neither inhibiting nor genetically disrupting M1R impairs the consolidation of cued fear memory. Using the M1R agonist cevimeline and antagonist telenzepine, as well as M1R knock-out mice, we show here that M1R, along with β2-adrenergic (β2AR) and D5-dopaminergic (D5R) receptors, regulates the consolidation of cued fear memory by redundantly activating phospholipase C (PLC) in the basolateral amygdala (BLA). We also demonstrate that fear memory consolidation in the BLA is mediated in part by neuromodulatory inhibition of the M-current, which is conducted by KCNQ channels and is known to be inhibited by muscarinic receptors. Manipulating the M-current by administering the KCNQ channel blocker XE991 or the KCNQ channel opener retigabine reverses the effects on consolidation caused by manipulating β2AR, D5R, M1R, and PLC. Finally, we show that cAMP and protein kinase A (cAMP/PKA) signaling relevant to this stage of consolidation is upstream of these neuromodulators and PLC, suggesting an important presynaptic role for cAMP/PKA in consolidation. These results support the idea that neuromodulatory regulation of ion channel activity and neuronal excitability is a critical mechanism for promoting consolidation well after acquisition has occurred.
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44
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Structural basis of PI(4,5)P2-dependent regulation of GluA1 by phosphatidylinositol-5-phosphate 4-kinase, type II, alpha (PIP5K2A). Pflugers Arch 2014; 466:1885-97. [PMID: 24389605 PMCID: PMC4159565 DOI: 10.1007/s00424-013-1424-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/21/2013] [Accepted: 12/08/2013] [Indexed: 12/19/2022]
Abstract
Ionotropic glutamate receptors are the most important excitatory receptors in the central nervous system, and their impairment can lead to multiple neuronal diseases. Here, we show that glutamate-induced currents in oocytes expressing GluA1 are increased by coexpression of the schizophrenia-associated phosphoinositide kinase PIP5K2A. This effect was due to enhanced membrane abundance and was blunted by a point mutation (N251S) in PIP5K2A. An increase in GluA1 currents was also observed upon acute injection of PI(4,5)P2, the main product of PIP5K2A. By expression of wild-type and mutant PIP5K2A in human embryonic kidney cells, we were able to provide evidence of impaired kinase activity of the mutant PIP5K2A. We defined the region K813–K823 of GluA1 as critical for the PI(4,5)P2 effect by performing an alanine scan that suggested PI(4,5)P2 binding to this area. A PIP strip assay revealed PI(4,5)P2 binding to the C-terminal GluA1 peptide. The present observations disclose a novel mechanism in the regulation of GluA1.
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45
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MAP1B-dependent Rac activation is required for AMPA receptor endocytosis during long-term depression. EMBO J 2013; 32:2287-99. [PMID: 23881099 DOI: 10.1038/emboj.2013.166] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 07/02/2013] [Indexed: 02/07/2023] Open
Abstract
The microtubule-associated protein 1B (MAP1B) plays critical roles in neurite growth and synapse maturation during brain development. This protein is well expressed in the adult brain. However, its function in mature neurons remains unknown. We have used a genetically modified mouse model and shRNA techniques to assess the role of MAP1B at established synapses, bypassing MAP1B functions during neuronal development. Under these conditions, we found that MAP1B deficiency alters synaptic plasticity by specifically impairing long-term depression (LTD) expression. Interestingly, this is due to a failure to trigger AMPA receptor endocytosis and spine shrinkage during LTD. These defects are accompanied by an impaired targeting of the Rac1 activator Tiam1 at synaptic compartments. Accordingly, LTD and AMPA receptor endocytosis are restored in MAP1B-deficient neurons by providing additional Rac1. Therefore, these results indicate that the MAP1B-Tiam1-Rac1 relay is essential for spine structural plasticity and removal of AMPA receptors from synapses during LTD. This work highlights the importance of MAPs as signalling hubs controlling the actin cytoskeleton and receptor trafficking during plasticity in mature neurons.
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46
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A-kinase anchoring protein-calcineurin signaling in long-term depression of GABAergic synapses. J Neurosci 2013; 33:2650-60. [PMID: 23392692 DOI: 10.1523/jneurosci.2037-12.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The postsynaptic scaffolding A-kinase anchoring protein 79/150 (AKAP79/150) signaling complex regulates excitatory synaptic transmission and strength through tethering protein kinase A (PKA), PKC, and calcineurin (CaN) to the postsynaptic densities of neurons (Sanderson and Dell'Acqua, 2011), but its role in inhibitory synaptic transmission and plasticity is unknown. Using immunofluorescence and whole-cell patch-clamp recording in rat midbrain slices, we show that activation of postsynaptic D(2)-like family of dopamine (DA) receptor in the ventral tegmental area (VTA) induces long-term depression (LTD) of GABAergic synapses on DA neurons through an inositol triphosphate receptor-mediated local rise in postsynaptic Ca(2+) and CaN activation accompanied by PKA inhibition, which requires AKAP150 as a bridging signaling molecule. Our data also illuminate a requirement for a clathrin-mediated internalization of GABA(A) receptors in expression of LTD(GABA). Moreover, disruption of AKAP-PKA anchoring does not affect glutamatergic synapses onto DA neurons, suggesting that the PKA-AKAP-CaN complex is uniquely situated at GABA(A) receptor synapses in VTA DA neurons to regulate plasticity associated with GABA(A) receptors. Drug-induced modulation of GABAergic plasticity in the VTA through such novel signaling mechanisms has the potential to persistently alter the output of individual DA neurons and of the VTA, which may contribute to the reinforcing or addictive properties of drugs of abuse.
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47
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Zhang J, Shapiro MS. Activity-dependent transcriptional regulation of M-Type (Kv7) K(+) channels by AKAP79/150-mediated NFAT actions. Neuron 2013; 76:1133-46. [PMID: 23259949 DOI: 10.1016/j.neuron.2012.10.019] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2012] [Indexed: 10/27/2022]
Abstract
M-type K(+) channels, encoded by KCNQ2-KCNQ5 genes, play key roles in regulation of neuronal excitability; however, less is known about the mechanisms controlling their transcriptional expression. Here, we discovered a mechanism regulating KCNQ2/3 transcriptional expression by neuronal activity in rodent neurons, involving activation of calcineurin and nuclear factor of activated T cell (NFAT) transcription factors, orchestrated by A kinase-anchoring protein (AKAP)79/150. The signal requires Ca(2+) influx through L-type Ca(2+) channels and both local and global Ca(2+) elevations. We postulate increased M-channel expression to act as a negative feedback to suppress neuronal hyperexcitability, demonstrated by profoundly upregulated KCNQ2/3 transcription in hippocampi from wild-type, but not AKAP150(-/-), mice after drug-induced seizures. Thus, we suggest a distinct role of AKAP79/150 and the complex it organizes in activity-dependent M-channel transcription, which may potentially serve throughout the nervous system to limit overexcitability associated with disease states such as epilepsy.
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Affiliation(s)
- Jie Zhang
- Department of Physiology, MS 7756, University of Texas Health Science Center, San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
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48
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Trovò L, Ahmed T, Callaerts-Vegh Z, Buzzi A, Bagni C, Chuah M, Vandendriessche T, D'Hooge R, Balschun D, Dotti CG. Low hippocampal PI(4,5)P₂ contributes to reduced cognition in old mice as a result of loss of MARCKS. Nat Neurosci 2013; 16:449-55. [PMID: 23434911 DOI: 10.1038/nn.3342] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 01/18/2013] [Indexed: 02/03/2023]
Abstract
Cognitive and motor performances decline during aging. Although it is clear that such signs reflect synaptic compromise, the underlying mechanisms have not been defined. We found that the levels and activity of the synaptic plasticity modulators phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P₂) and phospholipase Cγ (PLCγ) were substantially reduced in hippocampal synaptic membranes from old mice. In addition, these membranes contained reduced levels of the PI(4,5)P₂-clustering molecule myristoylated alanine-rich C kinase substrate (MARCKS). Consistent with a cause-effect relationship, raising MARCKS levels in the brain of old mice led to increased synaptic membrane clustering of PI(4,5)P₂ and to PLCγ activation. MARCKS overexpression in the hippocampus of old mice or intraventricular perfusion of MARCKS peptide resulted in enhanced long-term potentiation and improved memory. These results reveal one of the mechanisms involved in brain dysfunction during aging.
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Affiliation(s)
- Laura Trovò
- VIB Center for the Biology of Disease, Leuven and Center for Human Genetics, University of Leuven (Katholieke University of Leuven), Leuven, Belgium
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49
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AKAP150-anchored calcineurin regulates synaptic plasticity by limiting synaptic incorporation of Ca2+-permeable AMPA receptors. J Neurosci 2013; 32:15036-52. [PMID: 23100425 DOI: 10.1523/jneurosci.3326-12.2012] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AMPA receptors (AMPARs) are tetrameric ion channels assembled from GluA1-GluA4 subunits that mediate the majority of fast excitatory synaptic transmission in the brain. In the hippocampus, most synaptic AMPARs are composed of GluA1/2 or GluA2/3 with the GluA2 subunit preventing Ca(2+) influx. However, a small number of Ca(2+)-permeable GluA1 homomeric receptors reside in extrasynaptic locations where they can be rapidly recruited to synapses during synaptic plasticity. Phosphorylation of GluA1 S845 by the cAMP-dependent protein kinase (PKA) primes extrasynaptic receptors for synaptic insertion in response to NMDA receptor Ca(2+) signaling during long-term potentiation (LTP), while phosphatases dephosphorylate S845 and remove synaptic and extrasynaptic GluA1 during long-term depression (LTD). PKA and the Ca(2+)-activated phosphatase calcineurin (CaN) are targeted to GluA1 through binding to A-kinase anchoring protein 150 (AKAP150) in a complex with PSD-95, but we do not understand how the opposing activities of these enzymes are balanced to control plasticity. Here, we generated AKAP150ΔPIX knock-in mice to selectively disrupt CaN anchoring in vivo. We found that AKAP150ΔPIX mice lack LTD but express enhanced LTP at CA1 synapses. Accordingly, basal GluA1 S845 phosphorylation is elevated in AKAP150ΔPIX hippocampus, and LTD-induced dephosphorylation and removal of GluA1, AKAP150, and PSD-95 from synapses are impaired. In addition, basal synaptic activity of GluA2-lacking AMPARs is increased in AKAP150ΔPIX mice and pharmacologic antagonism of these receptors restores normal LTD and inhibits the enhanced LTP. Thus, AKAP150-anchored CaN opposes PKA phosphorylation of GluA1 to restrict synaptic incorporation of Ca(2+)-permeable AMPARs both basally and during LTP and LTD.
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50
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Sheng H, Xu Y, Chen Y, Zhang Y, Ni X. Corticotropin-releasing hormone stimulates mitotic kinesin-like protein 1 expression via a PLC/PKC-dependent signaling pathway in hippocampal neurons. Mol Cell Endocrinol 2012; 362:157-64. [PMID: 22698524 DOI: 10.1016/j.mce.2012.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 06/04/2012] [Accepted: 06/05/2012] [Indexed: 12/22/2022]
Abstract
Corticotropin-releasing hormone (CRH) has been shown to modulate dendritic development in hippocampus. Mitotic kinesin-like protein 1 (MKLP1) plays key roles in dendritic differentiation. In the present study, we examined the effects of CRH on MKLP1 expression in cultured hippocampal neurons and determine subsequent signaling pathways involved. CRH dose-dependently increased MKLP1 mRNA and protein expression. This effect can be reversed by CRHR1 antagonist but not by CRHR2 antagonist. CRHR1 knockdown impaired this effect of CRH. CRH stimulated GTP-bound Gαs protein and phosphorylated phospholipase C (PLC)-β3 expression, which were blocked by CRHR1 antagonist. Transfection of GP antagonist-2A, an inhibitory peptide of Gαq protein, blocked CRH-induced phosphorylated PLC-β3 expression. PLC and PKC inhibitors completely blocked whereas adenylyl cyclase (AC) and PKA inhibitors did not affect CRH-induced MKLP1 expression. Our results indicate that CRH act on CRHR1 to induce MKLP1 expression via PLC/PKC signaling pathway. CRH may regulate MKLP1 expression, thereby modulating dendritic development.
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Affiliation(s)
- Hui Sheng
- Department of Physiology and The Key Laboratory of Molecular Neurobiology of Ministry of Education, Second Military Medical University, Shanghai 200433, PR China
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