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Activation of non-classical NMDA receptors by glycine impairs barrier function of brain endothelial cells. Cell Mol Life Sci 2022; 79:479. [PMID: 35951110 PMCID: PMC9372018 DOI: 10.1007/s00018-022-04502-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/04/2022] [Accepted: 07/16/2022] [Indexed: 12/24/2022]
Abstract
Blood–brain barrier (BBB) integrity is necessary to maintain homeostasis of the central nervous system (CNS). NMDA receptor (NMDAR) function and expression have been implicated in BBB integrity. However, as evidenced in neuroinflammatory conditions, BBB disruption contributes to immune cell infiltration and propagation of inflammatory pathways. Currently, our understanding of the pathophysiological role of NMDAR signaling on endothelial cells remains incomplete. Thus, we investigated NMDAR function on primary mouse brain microvascular endothelial cells (MBMECs). We detected glycine-responsive NMDAR channels, composed of functional GluN1, GluN2A and GluN3A subunits. Importantly, application of glycine alone, but not glutamate, was sufficient to induce NMDAR-mediated currents and an increase in intracellular Ca2+ concentrations. Functionally, glycine-mediated NMDAR activation leads to loss of BBB integrity and changes in actin distribution. Treatment of oocytes that express NMDARs composed of different subunits, with GluN1 and GluN3A binding site inhibitors, resulted in abrogation of NMDAR signaling as measured by two-electrode voltage clamp (TEVC). This effect was only detected in the presence of the GluN2A subunits, suggesting the latter as prerequisite for pharmacological modulation of NMDARs on brain endothelial cells. Taken together, our findings argue for a novel role of glycine as NMDAR ligand on endothelial cells shaping BBB integrity.
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Singh S, Winkelstein BA. Inhibiting the β1integrin subunit increases the strain threshold for neuronal dysfunction under tensile loading in collagen gels mimicking innervated ligaments. Biomech Model Mechanobiol 2022; 21:885-898. [DOI: 10.1007/s10237-022-01565-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 02/13/2022] [Indexed: 11/28/2022]
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NMDA mediates disruption of blood-brain barrier permeability via Rho/ROCK signaling pathway. Neurochem Int 2022; 154:105278. [PMID: 35017026 DOI: 10.1016/j.neuint.2022.105278] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 12/21/2021] [Accepted: 01/05/2022] [Indexed: 01/14/2023]
Abstract
Glutamate can activate the N-methyl-D-aspartatic acid (NMDA) receptor (NMDAR), damage brain microvascular endothelial cells, and disturb the intercellular tight junctions (TJs). These result in changes in the permeability of the blood brain barrier (BBB). In neurons, the activation of Rho/ROCK signaling pathway is related to the activation of NMDAR,however, whether human brain vascular endothelial cells NMDAR mediates the Rho/ROCK pathway is not fully understood. The present study evaluates the effects of excessive NMDAR activation induced by NMDA (a glutamate analog) on the Rho/ROCK signaling pathway and the permeability of BBB by using a primary human brain microvascular endothelial cell (HBMEC) model. NMDAR subunit GluN1 was expressed in HBMECs and promoted by NMDA detected by Western blot and qRT-PCR. Furthermore, NMDA exposure decreased HBMEC viability, promoted HBMEC apoptosis, increased intracellular reactive oxygen species (ROS) levels, and destroyed the endothelial cytoskeleton. Additionally, NMDA exposure suppressed transendothelial electrical resistance (TEER) values and the expression of TJ proteins occludin and claudin5; it also promoted ROCK activated substrate myosin phosphatase target subunit-1 (MYPT)-1 phosphorylation and the transmittance of sodium fluorescein. In contrast, these effects were attenuated by ROCK inhibitor hydroxyfasudil (HF) and NMDAR antagonist MK801, respectively. Therefore, these results indicate that excessive endothelial NMDAR activation induced by NMDA may induce TJs and cytoskeleton damage, while HF attenuated NMDA-induced cytotoxicity in HBMECs by inhibiting the Rho/ROCK signaling pathway.
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Dutta P, Bharti P, Kumar J, Maiti S. Role of actin cytoskeleton in the organization and function of ionotropic glutamate receptors. Curr Res Struct Biol 2021; 3:277-289. [PMID: 34766008 PMCID: PMC8569634 DOI: 10.1016/j.crstbi.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/04/2021] [Accepted: 10/09/2021] [Indexed: 12/22/2022] Open
Abstract
Neural networks with precise connection are compulsory for learning and memory. Various cellular events occur during the genesis of dendritic spines to their maturation, synapse formation, stabilization of the synapse, and proper signal transmission. The cortical actin cytoskeleton and its multiple regulatory proteins are crucial for the above cellular events. The different types of ionotropic glutamate receptors (iGluRs) present on the postsynaptic density (PSD) are also essential for learning and memory. Interaction of the iGluRs in association of their auxiliary proteins with actin cytoskeleton regulated by actin-binding proteins (ABPs) are required for precise long-term potentiation (LTP) and long-term depression (LTD). There has been a quest to understand the mechanistic detail of synapse function involving these receptors with dynamic actin cytoskeleton. A major, emerging area of investigation is the relationship between ABPs and iGluRs in synapse development. In this review we have summarized the current understanding of iGluRs functioning with respect to the actin cytoskeleton, scaffolding proteins, and their regulators. The AMPA, NMDA, Delta and Kainate receptors need the stable underlying actin cytoskeleton to anchor through synaptic proteins for precise synapse formation. The different types of ABPs present in neurons play a critical role in dynamizing/stabilizing the actin cytoskeleton needed for iGluRs function.
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Affiliation(s)
- Priyanka Dutta
- National Centre for Cell Science, Pune, Maharashtra, 411007, India
| | - Pratibha Bharti
- National Centre for Cell Science, Pune, Maharashtra, 411007, India
| | - Janesh Kumar
- National Centre for Cell Science, Pune, Maharashtra, 411007, India
| | - Sankar Maiti
- Indian Institute of Science Education and Research, Kolkata, 741246, India
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Xu Y, Liu S, Zhu L, Dai L, Qian W, Zhang J, Li X, Pan W. Green tea protects against hippocampal neuronal apoptosis in diabetic encephalopathy by inhibiting JNK/MLCK signaling. Mol Med Rep 2021; 24:575. [PMID: 34132368 PMCID: PMC8223107 DOI: 10.3892/mmr.2021.12214] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 04/15/2021] [Indexed: 12/23/2022] Open
Abstract
Although diabetic encephalopathy (DE) is a major late complication of diabetes, the pathophysiology of postural instability in DE remains poorly understood. Prior studies have suggested that neuronal apoptosis is closely associated with cognitive function, but the mechanism remains to be elucidated. Green tea, which is a non-fermented tea, contains a number of tea polyphenols, alkaloids, amino acids, polysaccharides and other components. Some studies have found that drinking green tea can reduce the incidence of neurodegenerative diseases and improve cognitive dysfunction. We previously found that myosin light chain kinase (MLCK) regulates apoptosis in high glucose-induced hippocampal neurons. In neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, activation of the JNK signaling pathway promotes neuronal apoptosis. However, the relationship between JNK and MLCK remains to be elucidated. Green tea serum was obtained using seropharmacological methods and applied to hippocampal neurons. In addition, a type 1 diabetes rat model was established and green tea extract was administered, and the Morris water maze test, Cell Counting Kit-8 assays, flow cytometry, western blotting and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling assays were used to examine the effects of green tea on hippocampal neuronal apoptosis in diabetic rats. The results demonstrated that green tea can protect against hippocampal neuronal apoptosis by inhibiting the JNK/MLCK pathway and ultimately improves cognitive function in diabetic rats. The present study provided novel insights into the neuroprotective effects of green tea.
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Affiliation(s)
- Yongjie Xu
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
| | - Shengju Liu
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
| | - Liying Zhu
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
| | - Longguang Dai
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
| | - Wen Qian
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
| | - Jingzhi Zhang
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
| | - Xing Li
- Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550004, P.R. China
| | - Wei Pan
- Department of Medical Laboratory, Affiliated Hospital of Guizhou Medical University, Guiyang Medical College, Guiyang, Guizhou 550004, P.R. China
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Changes in synaptic proteins of the complex PSD-95/NMDA receptor/nNOS and mitochondrial dysfunction after levocabastine treatment. Neurochem Int 2021; 148:105100. [PMID: 34139299 DOI: 10.1016/j.neuint.2021.105100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/26/2021] [Accepted: 06/10/2021] [Indexed: 11/22/2022]
Abstract
Nitric oxide generation is related to the activity of certain proteins located at synaptic sites. Previous findings show that NOS activity, nNOS protein expression, respiratory parameters and mitochondrial complex activities are altered in rat cerebral cortex by administration of levocabastine, an antagonist of histamine H1 and neurotensin NTS2 receptors. ATP provision by mitochondria may play an important role in the functional interaction between synaptic proteins NMDA receptor and PSD-95 with NO synthesis. In this context, our purpose was to evaluate the effect of levocabastine administration on protein expression of PSD-95, GluN2B and iNOS, as well as on mitochondrial ATP production. Male Wistar rats received a single (i.p.) dose of levocabastine (50 μg/kg) or saline solution (controls) and were decapitated 18 h later. Mitochondrial and synaptosomal membrane fractions were isolated from cerebral cortex by differential and sucrose gradient centrifugation. Expression of synaptic proteins was evaluated by Western blot assays in synaptosomal membrane fractions. Oxygen consumption, mitochondrial membrane potential and ATP production rate were determined in fresh crude mitochondrial fractions. After levocabastine treatment, protein expression of PSD-95, GluN2B and β-actin decreased 97, 45 and 55%, respectively, whereas that of iNOS enhanced 3.5-fold versus controls. In crude mitochondrial fractions levocabastine administration reduced roughly 15% respiratory control rate as assayed with malate-glutamate or succinate as substrates, decreased mitochondrial membrane potential (21%), and ATP production rates (57%). Results suggested that levocabastine administration induces alterations in synaptic proteins of the protein complex PSD-95/NMDA receptor/nNOS and in neuron cytoskeleton. Mitochondrial bioenergetics impairment may play a role in the functional link between synaptic proteins and NO synthesis.
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Bozic M, Caus M, Rodrigues-Diez RR, Pedraza N, Ruiz-Ortega M, Garí E, Gallel P, Panadés MJ, Martinez A, Fernández E, Valdivielso JM. Protective role of renal proximal tubular alpha-synuclein in the pathogenesis of kidney fibrosis. Nat Commun 2020; 11:1943. [PMID: 32327648 PMCID: PMC7181766 DOI: 10.1038/s41467-020-15732-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/24/2020] [Indexed: 12/26/2022] Open
Abstract
Kidney fibrosis is a highly deleterious process and a final manifestation of chronic kidney disease. Alpha-(α)-synuclein (SNCA) is an actin-binding neuronal protein with various functions within the brain; however, its role in other tissues is unknown. Here, we describe the expression of SNCA in renal epithelial cells and demonstrate its decrease in renal tubules of murine and human fibrotic kidneys, as well as its downregulation in renal proximal tubular epithelial cells (RPTECs) after TGF-β1 treatment. shRNA-mediated knockdown of SNCA in RPTECs results in de novo expression of vimentin and α-SMA, while SNCA overexpression represses TGF-β1-induced mesenchymal markers. Conditional gene silencing of SNCA in RPTECs leads to an exacerbated tubulointerstitial fibrosis (TIF) in two unrelated in vivo fibrotic models, which is associated with an increased activation of MAPK-p38 and PI3K-Akt pathways. Our study provides an evidence that disruption of SNCA signaling in RPTECs contributes to the pathogenesis of renal TIF by facilitating partial epithelial-to-mesenchymal transition and extracellular matrix accumulation.
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Affiliation(s)
- Milica Bozic
- Vascular and Renal Translational Research Group, Institute for Biomedical Research in Lleida (IRBLleida) and RedInRen Retic, ISCIII, Spain.
| | - Maite Caus
- Vascular and Renal Translational Research Group, Institute for Biomedical Research in Lleida (IRBLleida) and RedInRen Retic, ISCIII, Spain
| | - Raul R Rodrigues-Diez
- Cellular and Molecular Biology in Renal and Vascular Pathology, IIS-Fundación Jiménez Díaz-Universidad Autónoma Madrid, Madrid, Spain
| | - Neus Pedraza
- Cell Cycle, Department of Basic Medical Science, IRBLleida, University of Lleida, Lleida, Spain
| | - Marta Ruiz-Ortega
- Cellular and Molecular Biology in Renal and Vascular Pathology, IIS-Fundación Jiménez Díaz-Universidad Autónoma Madrid, Madrid, Spain
| | - Eloi Garí
- Cell Cycle, Department of Basic Medical Science, IRBLleida, University of Lleida, Lleida, Spain
| | - Pilar Gallel
- Department of Pathology and Molecular Genetics, University Hospital Arnau de Vilanova and University of Lleida, IRBLleida, Spain
| | - Maria José Panadés
- Department of Pathology and Molecular Genetics, University Hospital Arnau de Vilanova and University of Lleida, IRBLleida, Spain
| | - Ana Martinez
- Vascular and Renal Translational Research Group, Institute for Biomedical Research in Lleida (IRBLleida) and RedInRen Retic, ISCIII, Spain
| | - Elvira Fernández
- Vascular and Renal Translational Research Group, Institute for Biomedical Research in Lleida (IRBLleida) and RedInRen Retic, ISCIII, Spain
| | - José Manuel Valdivielso
- Vascular and Renal Translational Research Group, Institute for Biomedical Research in Lleida (IRBLleida) and RedInRen Retic, ISCIII, Spain.
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Gruszczynska-Biegala J, Strucinska K, Maciag F, Majewski L, Sladowska M, Kuznicki J. STIM Protein-NMDA2 Receptor Interaction Decreases NMDA-Dependent Calcium Levels in Cortical Neurons. Cells 2020; 9:E160. [PMID: 31936514 PMCID: PMC7017226 DOI: 10.3390/cells9010160] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/05/2020] [Accepted: 01/07/2020] [Indexed: 01/08/2023] Open
Abstract
Neuronal Store-Operated Ca2+ Entry (nSOCE) plays an essential role in refilling endoplasmic reticulum Ca2+ stores and is critical for Ca2+-dependent neuronal processes. SOCE sensors, STIM1 and STIM2, can activate Orai, TRP channels and AMPA receptors, and inhibit voltage-gated channels in the plasma membrane. However, the link between STIM, SOCE, and NMDA receptors, another key cellular entry point for Ca2+ contributing to synaptic plasticity and excitotoxicity, remains unclear. Using Ca2+ imaging, we demonstrated that thapsigargin-induced nSOCE was inhibited in rat cortical neurons following NMDAR inhibitors. Blocking nSOCE by its inhibitor SKF96365 enhanced NMDA-driven [Ca2+]i. Modulating STIM protein level through overexpression or shRNA inhibited or activated NMDA-evoked [Ca2+]i, respectively. Using proximity ligation assays, immunofluorescence, and co-immunoprecipitation methods, we discovered that thapsigargin-dependent effects required interactions between STIMs and the NMDAR2 subunits. Since STIMs modulate NMDAR-mediated Ca2+ levels, we propose targeting this mechanism as a novel therapeutic strategy against neuropathological conditions that feature NMDA-induced Ca2+ overload as a diagnostic criterion.
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Affiliation(s)
- Joanna Gruszczynska-Biegala
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland; (K.S.); (F.M.); (L.M.); (M.S.); (J.K.)
- Molecular Biology Unit, Mossakowski Medical Research Centre Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Klaudia Strucinska
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland; (K.S.); (F.M.); (L.M.); (M.S.); (J.K.)
| | - Filip Maciag
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland; (K.S.); (F.M.); (L.M.); (M.S.); (J.K.)
| | - Lukasz Majewski
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland; (K.S.); (F.M.); (L.M.); (M.S.); (J.K.)
| | - Maria Sladowska
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland; (K.S.); (F.M.); (L.M.); (M.S.); (J.K.)
| | - Jacek Kuznicki
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland; (K.S.); (F.M.); (L.M.); (M.S.); (J.K.)
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Brown CA, Del Corsso C, Zoidl C, Donaldson LW, Spray DC, Zoidl G. Tubulin-Dependent Transport of Connexin-36 Potentiates the Size and Strength of Electrical Synapses. Cells 2019; 8:E1146. [PMID: 31557934 PMCID: PMC6829524 DOI: 10.3390/cells8101146] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/12/2022] Open
Abstract
Connexin-36 (Cx36) electrical synapses strengthen transmission in a calcium/calmodulin (CaM)/calmodulin-dependent kinase II (CaMKII)-dependent manner similar to a mechanism whereby the N-methyl-D-aspartate (NMDA) receptor subunit NR2B facilitates chemical transmission. Since NR2B-microtubule interactions recruit receptors to the cell membrane during plasticity, we hypothesized an analogous modality for Cx36. We determined that Cx36 binding to tubulin at the carboxy-terminal domain was distinct from Cx43 and NR2B by binding a motif overlapping with the CaM and CaMKII binding motifs. Dual patch-clamp recordings demonstrated that pharmacological interference of the cytoskeleton and deleting the binding motif at the Cx36 carboxyl-terminal (CT) reversibly abolished Cx36 plasticity. Mechanistic details of trafficking to the gap-junction plaque (GJP) were probed pharmacologically and through mutational analysis, all of which affected GJP size and formation between cell pairs. Lys279, Ile280, and Lys281 positions were particularly critical. This study demonstrates that tubulin-dependent transport of Cx36 potentiates synaptic strength by delivering channels to GJPs, reinforcing the role of protein transport at chemical and electrical synapses to fine-tune communication between neurons.
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Affiliation(s)
- Cherie A Brown
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Cristiane Del Corsso
- Department of Biophysics and Physiology, Federal University of Rio de Janeiro-RJ, Rio de Janeiro 21941-901, Brazil.
| | - Christiane Zoidl
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Logan W Donaldson
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - David C Spray
- Department of Neuroscience, Albert Einstein College, Bronx, NY 10461, USA.
- Department of Medicine, Albert Einstein College, Bronx, NY 10461, USA.
| | - Georg Zoidl
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
- Department of Psychology, York University, Toronto, ON M3J 1P3, Canada.
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Smirnova L, Seregin A, Boksha I, Dmitrieva E, Simutkin G, Kornetova E, Savushkina O, Letova A, Bokhan N, Ivanova S, Zgoda V. The difference in serum proteomes in schizophrenia and bipolar disorder. BMC Genomics 2019; 20:535. [PMID: 31291891 PMCID: PMC6620192 DOI: 10.1186/s12864-019-5848-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Purpose of study is revealing significant differences in serum proteomes in schizophrenia and bipolar disorder (BD). RESULTS Quantitative mass-spectrometry based proteomic analysis was used to quantify proteins in the blood serum samples after the depletion of six major blood proteins. Comparison of proteome profiles of different groups revealed 27 proteins being specific for schizophrenia, and 18 - for BD. Protein set in schizophrenia was mostly associated with immune response, cell communication, cell growth and maintenance, protein metabolism and regulation of nucleic acid metabolism. Protein set in BD was mostly associated with immune response, regulating transport processes across cell membrane and cell communication, development of neurons and oligodendrocytes and cell growth. Concentrations of ankyrin repeat domain-containing protein 12 (ANKRD12) and cadherin 5 in serum samples were determined by ELISA. Significant difference between three groups was revealed in ANKRD12 concentration (p = 0.02), with maximum elevation of ANKRD12 concentration (median level) in schizophrenia followed by BD. Cadherin 5 concentration differed significantly (p = 0.035) between schizophrenic patients with prevailing positive symptoms (4.78 [2.71, 7.12] ng/ml) and those with prevailing negative symptoms (1.86 [0.001, 4.11] ng/ml). CONCLUSIONS Our results are presumably useful for discovering the new pathways involved in endogenous psychotic disorders.
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Affiliation(s)
- Liudmila Smirnova
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Alexander Seregin
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | | | - Elena Dmitrieva
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
- Siberian State Medical University, Tomsk, Russia
| | - German Simutkin
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Elena Kornetova
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
- Siberian State Medical University, Tomsk, Russia
| | | | | | - Nikolay Bokhan
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Svetlana Ivanova
- Mental Health Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
- Siberian State Medical University, Tomsk, Russia
| | - Victor Zgoda
- Institute of Biomedical Chemistry, Moscow, Russia
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11
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Kula B, Chen T, Kukley M. Glutamatergic signaling between neurons and oligodendrocyte lineage cells: Is it synaptic or non‐synaptic? Glia 2019; 67:2071-2091. [DOI: 10.1002/glia.23617] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/12/2019] [Accepted: 03/18/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Bartosz Kula
- Group of Neuron Glia InteractionUniversity of Tübingen Tübingen Germany
- Graduate Training Centre for NeuroscienceUniversity of Tübingen Tübingen Germany
| | - Ting‐Jiun Chen
- Center for Neuroscience ResearchChildren's Research Institute, Children's National Medical Center Washington District of Columbia
| | - Maria Kukley
- Group of Neuron Glia InteractionUniversity of Tübingen Tübingen Germany
- Research Institute for OphthalmologyUniversity Hospital Tübingen Tübingen Germany
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12
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Pharris MC, Patel NM, Kinzer-Ursem TL. Competitive Tuning Among Ca 2+/Calmodulin-Dependent Proteins: Analysis of in silico Model Robustness and Parameter Variability. Cell Mol Bioeng 2018; 11:353-365. [PMID: 31105797 DOI: 10.1007/s12195-018-0549-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Introduction Calcium/Calmodulin-dependent (Ca2+/CaM-dependent) regulation of protein signaling has long been recognized for its importance in a number of physiological contexts. Found in almost all eukaryotic cells, Ca2+/CaM-dependent signaling participates in muscle development, immune responses, cardiac myocyte function and regulation of neuronal connectivity. In excitatory neurons, dynamic changes in the strength of synaptic connections, known as synaptic plasticity, occur when calcium ions (Ca2+) flux through NMDA receptors and bind the Ca2+-sensor calmodulin (CaM). Ca2+/CaM, in turn, regulates downstream protein signaling in actin polymerization, receptor trafficking, and transcription factor activation.The activation of downstream Ca2+/CaM-dependent binding proteins (CBPs) is a function of the frequency of Ca2+ flux, such that each CBP is preferentially "tuned" to different Ca2+ input signals. We have recently reported that competition among CBPs for CaM binding is alone sufficient to recreate in silico the observed in vivo frequency-dependence of several CBPs. However, CBP activation may strongly depend on the identity and concentration of proteins that constitute the competitive pool; with important implications in the regulation of CBPs in both normal and disease states. Methods Here, we extend our previous deterministic model of competition among CBPs to include phosphodiesterases, AMPAR receptors that are important in synaptic plasticity, and enzymatic function of CBPs: cAMP regulation, kinase activity, and phosphatase activity. After rigorous parameterization and validation by global sensitivity analysis using Latin Hypercube Sampling (LHS) and Partial Rank Correlation Coefficients (PRCC), we explore how perturbing the competitive pool of CBPs influences downstream signaling events. In particular, we hypothesize that although perturbations may decrease activation of one CBP, increased activation of a separate, but enzymatically-related CBP could compensate for this loss, providing a homeostatic effect. Results and Conclusions First we compare dynamic model output of two models: a two-state model of Ca2+/CaM binding and a four-state model of Ca2+/CaM binding. We find that a four-state model of Ca2+/CaM binding best captures the dynamic nature of the rapid response of CaM and CBPs to Ca2+ flux in the system. Using global sensitivity analysis, we find that model output is robust to parameter variability. Indeed, although variations in the expression of the CaM buffer neurogranin (Ng) may cause a decrease in Ca2+/CaM-dependent kinase II (CaMKII) activation, overall AMPA receptor phosphorylation is preserved; ostensibly by a concomitant increase in adenylyl cyclase 8 (AC8)-mediated activation of protein kinase A (PKA). Indeed phosphorylation of AMPAR receptors by CaMKII and PKA is robust across a wide range of Ng concentrations, though increases in AMPAR phosphorylation is seen at low Ng levels approaching zero. Our results may explain recent counter-intuitive results in neurogranin knockout mice and provide further evidence that competitive tuning is an important mechanism in synaptic plasticity. These results may be readily translated to other Ca2+/CaM-dependent signaling systems in other cell types and can be used to suggest targeted experimental investigation to explain counter-intuitive or unexpected downstream signaling outcomes.Tamara Kinzer-Ursem is an Assistant Professor in the Weldon School of Biomedical Engineering. She received her B.S. in Bioengineering from the University of Toledo and her M.S. and Ph.D. degrees in Chemical Engineering from the University of Michigan, and her post-doctoral training in Molecular Neuroscience at the California Institute of Technology. Prior to joining Purdue she was the Head of R&D in Biochemistry at Maven Biotechnologies and Visiting Associate in Chemical Engineering at the California Institute of Technology.Research in the Kinzer-Ursem lab focuses on developing tools to advance quantitative descriptions of cellular processes and disease within three areas of expertise: 1) Using particle diffusivity measurements to quantify biomolecular processes. Particle diffusometry is being used as a sensitive biosensor to detect the presence of pathogens in environmental and patient samples. 2) Development of novel protein tagging technologies that are used to label proteins in vivo to enable quantitative description of protein function and elucidate disease mechanisms. 3) Computational modeling of signal transduction mechanisms to understand cellular processes. Using computational techniques, we have recently described "competitive tuning" as a mechanism that might be used to regulate information transfer through protein networks, with implications in cell behavior and drug target analysis.
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Affiliation(s)
- Matthew C Pharris
- Weldon School of Biomedical Engineering, Purdue University, 260 South Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Neal M Patel
- Weldon School of Biomedical Engineering, Purdue University, 260 South Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Tamara L Kinzer-Ursem
- Weldon School of Biomedical Engineering, Purdue University, 260 South Martin Jischke Drive, West Lafayette, IN 47907 USA
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Zhang S, Zhao E, Winkelstein BA. A Nociceptive Role for Integrin Signaling in Pain After Mechanical Injury to the Spinal Facet Capsular Ligament. Ann Biomed Eng 2017; 45:2813-2825. [PMID: 28924864 PMCID: PMC5693676 DOI: 10.1007/s10439-017-1917-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 09/01/2017] [Indexed: 12/17/2022]
Abstract
Integrins modulate chemically-induced nociception in a variety of inflammatory and neuropathic pain models. Yet, the role of integrins in mechanically-induced pain remains undefined, despite its well-known involvement in cell adhesion and mechanotransduction. Excessive spinal facet capsular ligament stretch is a common injury that induces morphological and functional changes in its innervating afferent neurons and can lead to pain. However, the local mechanisms underlying the translation from tissue deformation to pain signaling are unclear, impeding effective treatment. Therefore, the involvement of the integrin subunit β1 in pain signaling from facet injury was investigated in complementary in vivo and in vitro studies. An anatomical study in the rat identified expression of the integrin subunit β1 in dorsal root ganglion (DRG) neurons innervating the facet, with greater expression in peptidergic than non-peptidergic DRG neurons. Painful facet capsule stretch in the rat upregulated the integrin subunit β1 in small- and medium-diameter DRG neurons at day 7. Inhibiting the α2β1 integrin in a DRG-collagen culture prior to its stretch injury prevented strain-induced increases in axonal substance P (SP) in a dose-dependent manner. Together, these findings suggest that integrin subunit β1-dependent pathways may contribute to SP-mediated pain from mechanical injury of the facet capsular ligament.
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Affiliation(s)
- Sijia Zhang
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St, Philadelphia, PA, 19104-6321, USA
| | - Ethan Zhao
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St, Philadelphia, PA, 19104-6321, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St, Philadelphia, PA, 19104-6321, USA.
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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14
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Romano DR, Pharris MC, Patel NM, Kinzer-Ursem TL. Competitive tuning: Competition's role in setting the frequency-dependence of Ca2+-dependent proteins. PLoS Comput Biol 2017; 13:e1005820. [PMID: 29107982 PMCID: PMC5690689 DOI: 10.1371/journal.pcbi.1005820] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 11/16/2017] [Accepted: 10/13/2017] [Indexed: 01/20/2023] Open
Abstract
A number of neurological disorders arise from perturbations in biochemical signaling and protein complex formation within neurons. Normally, proteins form networks that when activated produce persistent changes in a synapse’s molecular composition. In hippocampal neurons, calcium ion (Ca2+) flux through N-methyl-D-aspartate (NMDA) receptors activates Ca2+/calmodulin signal transduction networks that either increase or decrease the strength of the neuronal synapse, phenomena known as long-term potentiation (LTP) or long-term depression (LTD), respectively. The calcium-sensor calmodulin (CaM) acts as a common activator of the networks responsible for both LTP and LTD. This is possible, in part, because CaM binding proteins are “tuned” to different Ca2+ flux signals by their unique binding and activation dynamics. Computational modeling is used to describe the binding and activation dynamics of Ca2+/CaM signal transduction and can be used to guide focused experimental studies. Although CaM binds over 100 proteins, practical limitations cause many models to include only one or two CaM-activated proteins. In this work, we view Ca2+/CaM as a limiting resource in the signal transduction pathway owing to its low abundance relative to its binding partners. With this view, we investigate the effect of competitive binding on the dynamics of CaM binding partner activation. Using an explicit model of Ca2+, CaM, and seven highly-expressed hippocampal CaM binding proteins, we find that competition for CaM binding serves as a tuning mechanism: the presence of competitors shifts and sharpens the Ca2+ frequency-dependence of CaM binding proteins. Notably, we find that simulated competition may be sufficient to recreate the in vivo frequency dependence of the CaM-dependent phosphatase calcineurin. Additionally, competition alone (without feedback mechanisms or spatial parameters) could replicate counter-intuitive experimental observations of decreased activation of Ca2+/CaM-dependent protein kinase II in knockout models of neurogranin. We conclude that competitive tuning could be an important dynamic process underlying synaptic plasticity. Learning and memory formation are likely associated with dynamic fluctuations in the connective strength of neuronal synapses. These fluctuations, called synaptic plasticity, are regulated by calcium ion (Ca2+) influx through ion channels localized to the post-synaptic membrane. Within the post-synapse, the dominant Ca2+ sensor protein, calmodulin (CaM), may activate a variety of downstream binding partners, each contributing to synaptic plasticity outcomes. The conditions at which certain binding partners most strongly activate are increasingly studied using computational models. Nearly all computational studies describe these binding partners in combinations of only one or two CaM binding proteins. In contrast, we combine seven well-studied CaM binding partners into a single model wherein they simultaneously compete for access to CaM. Our dynamic model suggests that competition narrows the window of conditions for optimal activation of some binding partners, mimicking the Ca2+-frequency dependence of some proteins in vivo. Further characterization of CaM-dependent signaling dynamics in neuronal synapses may benefit our understanding of learning and memory formation. Furthermore, we propose that competitive binding may be another framework, alongside feedback and feed-forward loops, signaling motifs, and spatial localization, that can be applied to other signal transduction networks, particularly second messenger cascades, to explain the dynamical behavior of protein activation.
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Affiliation(s)
- Daniel R. Romano
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States of America
| | - Matthew C. Pharris
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States of America
| | - Neal M. Patel
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States of America
| | - Tamara L. Kinzer-Ursem
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States of America
- * E-mail:
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15
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Mittal N, Minasyan A, Romaneschi N, Hakimian JK, Gonzalez-Fernandez G, Albert R, Desai N, Mendez IA, Schallert T, Ostlund SB, Walwyn W. Beta-arrestin 1 regulation of reward-motivated behaviors and glutamatergic function. PLoS One 2017; 12:e0185796. [PMID: 28973019 PMCID: PMC5626489 DOI: 10.1371/journal.pone.0185796] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/19/2017] [Indexed: 01/10/2023] Open
Abstract
The two highly homologous non-visual arrestins, beta-arrestin 1 and 2, are ubiquitously expressed in the central nervous system, yet knowledge of their disparate roles is limited. While beta-arrestin 2 (βarr2) has been implicated in several aspects of reward-related learning and behavior, very little is known about the behavioral function of beta-arrestin 1 (βarr1). Using mice lacking βarr1, we focused on the role of this scaffolding and signal transduction protein in reward-motivated behaviors and in striatal glutamatergic function. We found that βarr1 KO mice were both slower in acquiring cocaine self-administration and in extinguishing this behavior. They also showed deficits in learning tasks supported by a natural food reward, suggesting a general alteration in reward processing. We then examined glutamatergic synaptic strength in WT and KO medium spiny neurons (MSNs) of the Nucleus Accumbens (NAc) shell in naïve animals, and from those that underwent cocaine self-administration. An increase in the AMPA/NMDA (A/N) ratio and a relative lack of GluN2B-enriched NMDARs was found in naïve KO vs WT MSNs. Applying Lim Domain Kinase (LIMK1), the kinase that phosphorylates and inactivates cofilin, to these cells, showed that both βarr1 and LIMK regulate the A/N ratio and GluN2B-NMDARs. Cocaine self-administration increased the A/N ratio and GluN2B-NMDARs in WT MSNs and, although the A/N ratio also increased in KO MSNs, this was accompanied by fewer GluN2B-NMDARs and an appearance of calcium-permeable AMPARs. Finally, to examine the consequences of reduced basal GluN2B-NMDARs in reward-processing seen in KO mice, we chronically infused ifenprodil, a GluN2B antagonist, into the NAc shell of WT mice. This intervention substantially reduced food-motivated behavior. Together these findings identify a previously unknown role of βarr1 in regulating specific reward-motivated behaviors and glutamatergic function.
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Affiliation(s)
- Nitish Mittal
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, United States of America
| | - Ani Minasyan
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Nicole Romaneschi
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Joshua K. Hakimian
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Gabriel Gonzalez-Fernandez
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Ralph Albert
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Nina Desai
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Ian A. Mendez
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Timothy Schallert
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, United States of America
| | - Sean B. Ostlund
- Department of Anesthesiology and Perioperative Care, School of Medicine, University of California, Irvine, UCI Center for Addiction Neuroscience, School of Biological Sciences, University of California Irvine, Irvine, United States of America
| | - Wendy Walwyn
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States of America
- * E-mail:
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16
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Baucum AJ. Proteomic Analysis of Postsynaptic Protein Complexes Underlying Neuronal Plasticity. ACS Chem Neurosci 2017; 8:689-701. [PMID: 28211672 DOI: 10.1021/acschemneuro.7b00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Normal neuronal communication and synaptic plasticity at glutamatergic synapses requires dynamic regulation of postsynaptic molecules. Protein expression and protein post-translational modifications regulate protein interactions that underlie this organization. In this Review, we highlight data obtained over the last 20 years that have used qualitative and quantitative proteomics-based approaches to identify postsynaptic protein complexes. Herein, we describe how these proteomics studies have helped lay the foundation for understanding synaptic physiology and perturbations in synaptic signaling observed in different pathologies. We also describe emerging technologies that can be useful in these analyses. We focus on protein complexes associated with the highly abundant and functionally critical proteins: calcium/calmodulin-dependent protein kinase II, the N-methyl-d-aspartate, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors, and postsynaptic density protein of 95 kDa.
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Affiliation(s)
- Anthony J. Baucum
- Department of Biology, Stark Neurosciences
Research Institute, Indiana University-Purdue University Indianapolis, 723 W. Michigan St., Indianapolis, Indiana 46202, United States
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17
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Gruszczynska-Biegala J, Sladowska M, Kuznicki J. AMPA Receptors Are Involved in Store-Operated Calcium Entry and Interact with STIM Proteins in Rat Primary Cortical Neurons. Front Cell Neurosci 2016; 10:251. [PMID: 27826230 PMCID: PMC5078690 DOI: 10.3389/fncel.2016.00251] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/13/2016] [Indexed: 11/13/2022] Open
Abstract
The process of store-operated calcium entry (SOCE) leads to refilling the endoplasmic reticulum (ER) with calcium ions (Ca2+) after their release into the cytoplasm. Interactions between (ER)-located Ca2+ sensors (stromal interaction molecule 1 [STIM1] and STIM2) and plasma membrane-located Ca2+ channel-forming protein (Orai1) underlie SOCE and are well described in non-excitable cells. In neurons, however, SOCE appears to be more complex because of the importance of Ca2+ influx via voltage-gated or ionotropic receptor-operated Ca2+ channels. We found that the SOCE inhibitors ML-9 and SKF96365 reduced α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-induced [Ca2+]i amplitude by 80% and 53%, respectively. To assess the possible involvement of AMPA receptors (AMPARs) in SOCE, we used their specific inhibitors. As estimated by Fura-2 acetoxymethyl (AM) single-cell Ca2+ measurements in the presence of CNQX or NBQX, thapsigargin (TG)-induced Ca2+ influx decreased 2.2 or 3.7 times, respectively. These results suggest that under experimental conditions of SOCE when Ca2+ stores are depleted, Ca2+ can enter neurons also through AMPARs. Using specific antibodies against STIM proteins or GluA1/GluA2 AMPAR subunits, co-immunoprecipitation assays indicated that when Ca2+ levels are low in the neuronal ER, a physical association occurs between endogenous STIM proteins and endogenous AMPAR receptors. Altogether, our data suggest that STIM proteins in neurons can control AMPA-induced Ca2+ entry as a part of the mechanism of SOCE.
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Affiliation(s)
- Joanna Gruszczynska-Biegala
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw Warsaw, Poland
| | - Maria Sladowska
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw Warsaw, Poland
| | - Jacek Kuznicki
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw Warsaw, Poland
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18
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Newell-Litwa KA, Horwitz R, Lamers ML. Non-muscle myosin II in disease: mechanisms and therapeutic opportunities. Dis Model Mech 2015; 8:1495-515. [PMID: 26542704 PMCID: PMC4728321 DOI: 10.1242/dmm.022103] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The actin motor protein non-muscle myosin II (NMII) acts as a master regulator of cell morphology, with a role in several essential cellular processes, including cell migration and post-synaptic dendritic spine plasticity in neurons. NMII also generates forces that alter biochemical signaling, by driving changes in interactions between actin-associated proteins that can ultimately regulate gene transcription. In addition to its roles in normal cellular physiology, NMII has recently emerged as a critical regulator of diverse, genetically complex diseases, including neuronal disorders, cancers and vascular disease. In the context of these disorders, NMII regulatory pathways can be directly mutated or indirectly altered by disease-causing mutations. NMII regulatory pathway genes are also increasingly found in disease-associated copy-number variants, particularly in neuronal disorders such as autism and schizophrenia. Furthermore, manipulation of NMII-mediated contractility regulates stem cell pluripotency and differentiation, thus highlighting the key role of NMII-based pharmaceuticals in the clinical success of stem cell therapies. In this Review, we discuss the emerging role of NMII activity and its regulation by kinases and microRNAs in the pathogenesis and prognosis of a diverse range of diseases, including neuronal disorders, cancer and vascular disease. We also address promising clinical applications and limitations of NMII-based inhibitors in the treatment of these diseases and the development of stem-cell-based therapies.
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Affiliation(s)
- Karen A Newell-Litwa
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Rick Horwitz
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Marcelo L Lamers
- Department of Morphological Sciences, Institute of Basic Health Science, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 90610-010, Brazil
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19
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Bu Y, Wang N, Wang S, Sheng T, Tian T, Chen L, Pan W, Zhu M, Luo J, Lu W. Myosin IIb-dependent Regulation of Actin Dynamics Is Required for N-Methyl-D-aspartate Receptor Trafficking during Synaptic Plasticity. J Biol Chem 2015; 290:25395-410. [PMID: 26330558 DOI: 10.1074/jbc.m115.644229] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Indexed: 12/21/2022] Open
Abstract
N-Methyl-d-aspartate receptor (NMDAR) synaptic incorporation changes the number of NMDARs at synapses and is thus critical to various NMDAR-dependent brain functions. To date, the molecules involved in NMDAR trafficking and the underlying mechanisms are poorly understood. Here, we report that myosin IIb is an essential molecule in NMDAR synaptic incorporation during PKC- or θ burst stimulation-induced synaptic plasticity. Moreover, we demonstrate that myosin light chain kinase (MLCK)-dependent actin reorganization contributes to NMDAR trafficking. The findings from additional mutual occlusion experiments demonstrate that PKC and MLCK share a common signaling pathway in NMDAR-mediated synaptic regulation. Because myosin IIb is the primary substrate of MLCK and can regulate actin dynamics during synaptic plasticity, we propose that the MLCK- and myosin IIb-dependent regulation of actin dynamics is required for NMDAR trafficking during synaptic plasticity. This study provides important insights into a mechanical framework for understanding NMDAR trafficking associated with synaptic plasticity.
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Affiliation(s)
- Yunfei Bu
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Ning Wang
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China, the Key Laboratory of Developmental Genes and Human Disease of the Ministry of Education of China, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Shaoli Wang
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China, the Key Laboratory of Developmental Genes and Human Disease of the Ministry of Education of China, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Tao Sheng
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China, the Key Laboratory of Developmental Genes and Human Disease of the Ministry of Education of China, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Tian Tian
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Linlin Chen
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Weiwei Pan
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Minsheng Zhu
- the Key Laboratory of Model Animal for Disease Study of the Ministry of Education of China, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu Province 210063, China, and
| | - Jianhong Luo
- the Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province 310058, China
| | - Wei Lu
- From the Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China, the Key Laboratory of Developmental Genes and Human Disease of the Ministry of Education of China, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China, the Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, China,
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20
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He Y, Wang F, Chen S, Liu M, Pan W, Li X. The Protective Effect of Radix Polygoni Multiflori on Diabetic Encephalopathy via Regulating Myosin Light Chain Kinase Expression. J Diabetes Res 2015; 2015:484721. [PMID: 26199947 PMCID: PMC4496489 DOI: 10.1155/2015/484721] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Currently there has been no effective treatment of diabetic encephalopathy. Radix Polygoni Multiflori, a famous traditional Chinese medicine, is widely used in antiaging treatment, especially in prevention and treatment of Alzheimer's diseases. In this study we tried to explore the effect of Radix Polygoni Multiflori on cognitive function among diabetic rats with demonstrated cognitive impairment. SD rats were divided into group A (control group), group B (diabetes), group C (treated with Radix Polygoni Multiflori at the dose of 2 g/kg/d), and group D (treated with same drug at the dose of 1 g/kg/d). The results showed that 8 weeks of Radix Polygoni Multiflori treatment could improve the cognitive dysfunction of diabetic rats (P < 0.01), recover the ultrastructure of hippocampal neurons, and increase the number of synapses in a dose-dependent manner. Further experiment also suggested that the neuroprotective effect of Radix Polygoni Multiflori was partly achieved by downregulating MLCK expression in hippocampus via ERK signaling.
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MESH Headings
- Animals
- Brain Diseases, Metabolic/complications
- Brain Diseases, Metabolic/prevention & control
- Cognition/drug effects
- Cognition Disorders/complications
- Cognition Disorders/prevention & control
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Diabetic Neuropathies/prevention & control
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Drugs, Chinese Herbal/administration & dosage
- Drugs, Chinese Herbal/therapeutic use
- Hypothalamus/drug effects
- Hypothalamus/metabolism
- Hypothalamus/ultrastructure
- MAP Kinase Signaling System/drug effects
- Male
- Maze Learning/drug effects
- Microscopy, Electron, Transmission
- Myosin-Light-Chain Kinase/antagonists & inhibitors
- Myosin-Light-Chain Kinase/chemistry
- Myosin-Light-Chain Kinase/metabolism
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neurons/drug effects
- Neurons/metabolism
- Neurons/ultrastructure
- Neuroprotective Agents/administration & dosage
- Neuroprotective Agents/therapeutic use
- Nootropic Agents/therapeutic use
- Rats, Sprague-Dawley
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Affiliation(s)
- Yu He
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Feng Wang
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Shiqiang Chen
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Mi Liu
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Wei Pan
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Xing Li
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
- *Xing Li:
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21
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Horak M, Petralia RS, Kaniakova M, Sans N. ER to synapse trafficking of NMDA receptors. Front Cell Neurosci 2014; 8:394. [PMID: 25505872 PMCID: PMC4245912 DOI: 10.3389/fncel.2014.00394] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/04/2014] [Indexed: 11/26/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. There are three distinct subtypes of ionotropic glutamate receptors (GluRs) that have been identified including 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid receptors (AMPARs), N-methyl-D-aspartate receptors (NMDARs) and kainate receptors. The most common GluRs in mature synapses are AMPARs that mediate the fast excitatory neurotransmission and NMDARs that mediate the slow excitatory neurotransmission. There have been large numbers of recent reports studying how a single neuron regulates synaptic numbers and types of AMPARs and NMDARs. Our current research is centered primarily on NMDARs and, therefore, we will focus in this review on recent knowledge of molecular mechanisms occurring (1) early in the biosynthetic pathway of NMDARs, (2) in the transport of NMDARs after their release from the endoplasmic reticulum (ER); and (3) at the plasma membrane including excitatory synapses. Because a growing body of evidence also indicates that abnormalities in NMDAR functioning are associated with a number of human psychiatric and neurological diseases, this review together with other chapters in this issue may help to enhance research and to gain further knowledge of normal synaptic physiology as well as of the etiology of many human brain diseases.
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Affiliation(s)
- Martin Horak
- Institute of Physiology, Academy of Sciences of the Czech Republic v.v.i. Prague, Czech Republic
| | - Ronald S Petralia
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health Bethesda, MD, USA
| | - Martina Kaniakova
- Institute of Physiology, Academy of Sciences of the Czech Republic v.v.i. Prague, Czech Republic
| | - Nathalie Sans
- Neurocentre Magendie, Institut National de la Santé et de la Recherche Médicale, U862 Bordeaux, France ; Neurocentre Magendie, University of Bordeaux, U862 Bordeaux, France
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22
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Krogh KA, Lyddon E, Thayer SA. HIV-1 Tat activates a RhoA signaling pathway to reduce NMDA-evoked calcium responses in hippocampal neurons via an actin-dependent mechanism. J Neurochem 2014; 132:354-66. [PMID: 25156524 DOI: 10.1111/jnc.12936] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/06/2014] [Accepted: 08/20/2014] [Indexed: 01/27/2023]
Abstract
HIV-associated neurocognitive disorders afflict approximately half of HIV-infected patients. HIV-infected cells within the CNS release neurotoxic viral proteins such as the transactivator of transcription (Tat). Tat caused a biphasic change in NMDAR function; NMDA-evoked increases in intracellular Ca(2+) were initially potentiated following 16 h exposure to Tat and then adapted by gradually returning to baseline by 24 h. Following Tat-induced NMDAR potentiation, a RhoA/Rho-associated protein kinase (ROCK) signaling pathway was activated; a subsequent remodeling of the actin cytoskeleton reduced NMDA-evoked increases in intracellular Ca(2+) . Pharmacologic or genetic inhibition of RhoA or ROCK failed to affect potentiation, but prevented adaptation of NMDAR function. Activation of RhoA/ROCK signaling increases the formation of filamentous actin. Drugs that prevent changes to filamentous actin blocked adaptation of NMDAR function following Tat-induced potentiation, whereas stimulating either depolymerization or polymerization of actin attenuated NMDAR function. These findings indicate that Tat activates a RhoA/ROCK signaling pathway resulting in actin remodeling and subsequent reduction of NMDAR function. Adaptation of NMDAR function may be a mechanism to protect neurons from excessive Ca(2+) influx and could reveal targets for the treatment of HIV-associated neurocognitive disorders.
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Affiliation(s)
- Kelly A Krogh
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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Mota SI, Ferreira IL, Valero J, Ferreiro E, Carvalho AL, Oliveira CR, Rego AC. Impaired Src signaling and post-synaptic actin polymerization in Alzheimer's disease mice hippocampus--linking NMDA receptors and the reelin pathway. Exp Neurol 2014; 261:698-709. [PMID: 25128699 DOI: 10.1016/j.expneurol.2014.07.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 07/12/2014] [Accepted: 07/27/2014] [Indexed: 11/16/2022]
Abstract
Early cognitive deficits in Alzheimer's disease (AD) have been related to deregulation of N-methyl-d-aspartate receptors (NMDARs) and synaptic dysfunction in response to amyloid-beta peptide. NMDAR anchorage to post-synaptic membrane depends in part on Src kinase, which is also implicated in NMDAR activation and actin cytoskeleton stabilization, two processes relevant for normal synaptic function. In this study we analyzed the changes in GluN2B subunit phosphorylation and the levels of proteins involved in Src related signaling pathways linking the Tyr kinase to actin cytoskeleton polymerization, namely reelin, disabled-1 (Dab1) and cortactin, in hippocampal and cortical homogenates obtained from the triple transgenic mouse model of AD (3xTg-AD) that shows progression of pathology as a function of age versus age-matched wild-type mice. Moreover, we evaluated regional post-synaptic actin polymerization using phalloidin labeling in hippocampal slices. Young (3month-old) 3xTg-AD male mice hippocampus exhibited decreased GluN2B Tyr1472 phosphorylation and reduced Src activity. In the cortex, decreased Src activity correlated with reduced levels of reelin and Dab1, implicating changes in the reelin pathway. We also observed diminished phosphorylated Dab1 and cortactin protein levels in the hippocampus and cortex of young 3xTg-AD male mice. Concordantly with the recognized role of these proteins in actin stabilization, we detected a significant decrease in post-synaptic F-actin in 3month-old 3xTg-AD male CA1 and CA3 hippocampal regions. These data suggest deregulated Src-dependent signaling pathways involving GluN2B-composed NMDARs and post-synaptic actin cytoskeleton depolymerization in the hippocampus in early stages of AD.
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Affiliation(s)
- Sandra I Mota
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal.
| | - Ildete L Ferreira
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal.
| | - Jorge Valero
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal.
| | - Elisabete Ferreiro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal.
| | - Ana L Carvalho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal; Life Science Department, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal.
| | - Catarina R Oliveira
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
| | - A Cristina Rego
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
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24
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Lamprecht R. The actin cytoskeleton in memory formation. Prog Neurobiol 2014; 117:1-19. [DOI: 10.1016/j.pneurobio.2014.02.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 01/21/2023]
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Krogh KA, Wydeven N, Wickman K, Thayer SA. HIV-1 protein Tat produces biphasic changes in NMDA-evoked increases in intracellular Ca2+ concentration via activation of Src kinase and nitric oxide signaling pathways. J Neurochem 2014; 130:642-56. [PMID: 24666322 DOI: 10.1111/jnc.12724] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 03/05/2014] [Accepted: 03/11/2014] [Indexed: 11/30/2022]
Abstract
HIV-associated neurocognitive disorders afflict about half of HIV-infected patients. HIV-infected cells shed viral proteins, such as the transactivator of transcription (Tat), which can cause neurotoxicity by over activation of NMDA receptors. Here, we show that Tat causes a time-dependent, biphasic change in NMDA-evoked increases in intracellular Ca(2+) concentration ([Ca(2+)]i). NMDA-evoked responses were potentiated following 2-h exposure to Tat (50 ng/mL). Tat-induced potentiation of NMDA-evoked increases in [Ca(2+)]i peaked by 8 h and then adapted by gradually reversing to baseline by 24 h and eventually dropping below control by 48 h. Tat-induced potentiation of NMDA-evoked responses was blocked by inhibition of lipoprotein receptor-related protein (LRP) or Src tyrosine kinase. Potentiation was unaffected by inhibition of nitric oxide synthase (NOS). However, NOS activity was required for adaptation. Adaptation was also prevented by inhibition of soluble guanylate cyclase (sGC) and cyclic guanosine monophosphate-dependent protein kinase G (PKG). Together, these findings indicate that Tat potentiates NMDA-evoked increases in [Ca(2+)]i via LRP-dependent activation of Src and that this potentiation adapts via activation of the NOS/sGC/PKG pathway. Adaptation may protect neurons from excessive Ca(2+) influx and could reveal targets for the treatment of HIV-associated neurocognitive disorders. HIV-associated neurocognitive disorders (HAND) afflict about half of HIV-infected patients. HIV-infected cells shed viral proteins, such as the transactivator of transcription (Tat), which can cause neurotoxicity by over activation of NMDA receptors (NMDARs). We show that HIV-1 Tat evoked biphasic changes in NMDA-evoked [Ca(2+) ]i responses. Initially, Tat potentiated NMDA-evoked responses following LRP-mediated activation of Src kinase. Subsequently, Tat-induced NMDAR potentiation adapted by activation of a NOS/sGC/PKG pathway that attenuated NMDA-evoked increases in [Ca(2+)]i . Adaptation may be a novel neuroprotective mechanism to prevent excessive Ca(2+) influx. Solid and dashed arrows represent direct and potentially indirect connections, respectively.
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Affiliation(s)
- Kelly A Krogh
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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26
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Recent progress in understanding subtype specific regulation of NMDA receptors by G Protein Coupled Receptors (GPCRs). Int J Mol Sci 2014; 15:3003-24. [PMID: 24562329 PMCID: PMC3958896 DOI: 10.3390/ijms15023003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 12/30/2013] [Accepted: 02/12/2014] [Indexed: 12/24/2022] Open
Abstract
G Protein Coupled Receptors (GPCRs) are the largest family of receptors whose ligands constitute nearly a third of prescription drugs in the market. They are widely involved in diverse physiological functions including learning and memory. NMDA receptors (NMDARs), which belong to the ionotropic glutamate receptor family, are likewise ubiquitously expressed in the central nervous system (CNS) and play a pivotal role in learning and memory. Despite its critical contribution to physiological and pathophysiological processes, few pharmacological interventions aimed directly at regulating NMDAR function have been developed to date. However, it is well established that NMDAR function is precisely regulated by cellular signalling cascades recruited downstream of G protein coupled receptor (GPCR) stimulation. Accordingly, the downstream regulation of NMDARs likely represents an important determinant of outcome following treatment with neuropsychiatric agents that target selected GPCRs. Importantly, the functional consequence of such regulation on NMDAR function varies, based not only on the identity of the GPCR, but also on the cell type in which relevant receptors are expressed. Indeed, the mechanisms responsible for regulating NMDARs by GPCRs involve numerous intracellular signalling molecules and regulatory proteins that vary from one cell type to another. In the present article, we highlight recent findings from studies that have uncovered novel mechanisms by which selected GPCRs regulate NMDAR function and consequently NMDAR-dependent plasticity.
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Mota SI, Ferreira IL, Rego AC. Dysfunctional synapse in Alzheimer's disease - A focus on NMDA receptors. Neuropharmacology 2013; 76 Pt A:16-26. [PMID: 23973316 DOI: 10.1016/j.neuropharm.2013.08.013] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/03/2013] [Accepted: 08/08/2013] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly. Alterations capable of causing brain circuitry dysfunctions in AD may take several years to develop. Oligomeric amyloid-beta peptide (Aβ) plays a complex role in the molecular events that lead to progressive loss of function and eventually to neurodegeneration in this devastating disease. Moreover, N-methyl-D-aspartate (NMDA) receptors (NMDARs) activation has been recently implicated in AD-related synaptic dysfunction. Thus, in this review we focus on glutamatergic neurotransmission impairment and the changes in NMDAR regulation in AD, following the description on the role and location of NMDARs at pre- and post-synaptic sites under physiological conditions. In addition, considering that there is currently no effective ways to cure AD or stop its progression, we further discuss the relevance of NMDARs antagonists to prevent AD symptomatology. This review posits additional information on the role played by Aβ in AD and the importance of targeting the tripartite glutamatergic synapse in early asymptomatic and possible reversible stages of the disease through preventive and/or disease-modifying therapeutic strategies. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
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Affiliation(s)
- Sandra I Mota
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal.
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28
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Collingridge GL, Volianskis A, Bannister N, France G, Hanna L, Mercier M, Tidball P, Fang G, Irvine MW, Costa BM, Monaghan DT, Bortolotto ZA, Molnár E, Lodge D, Jane DE. The NMDA receptor as a target for cognitive enhancement. Neuropharmacology 2012; 64:13-26. [PMID: 22796429 DOI: 10.1016/j.neuropharm.2012.06.051] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/22/2012] [Accepted: 06/24/2012] [Indexed: 12/31/2022]
Abstract
NMDA receptors (NMDARs) play an important role in neural plasticity including long-term potentiation and long-term depression, which are likely to explain their importance for learning and memory. Cognitive decline is a major problem facing an ageing human population, so much so that its reversal has become an important goal for scientific research and pharmaceutical development. Enhancement of NMDAR function is a core strategy toward this goal. In this review we indicate some of the major ways of potentiating NMDAR function by both direct and indirect modulation. There is good evidence that both positive and negative modulation can enhance function suggesting that a subtle approach correcting imbalances in particular clinical situations will be required. Excessive activation and the resultant deleterious effects will need to be carefully avoided. Finally we describe some novel positive allosteric modulators of NMDARs, with some subunit selectivity, and show initial evidence of their ability to affect NMDAR mediated events. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Graham L Collingridge
- MRC Centre for Synaptic Plasticity, School of Physiology and Pharmacology, University of Bristol, Bristol BS1 3NY, UK.
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29
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Xiao Z, Jaiswal MK, Deng PY, Matsui T, Shin HS, Porter JE, Lei S. Requirement of phospholipase C and protein kinase C in cholecystokinin-mediated facilitation of NMDA channel function and anxiety-like behavior. Hippocampus 2011; 22:1438-50. [PMID: 22072552 DOI: 10.1002/hipo.20984] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2011] [Indexed: 01/07/2023]
Abstract
Although cholecystokinin (CCK) has long been known to exert anxiogenic effects in both animal anxiety models and humans, the underlying cellular and molecular mechanisms are ill-defined. CCK interacts with CCK-1 and CCK-2 receptors resulting in up-regulation of phospholipase C (PLC) and protein kinase C (PKC). However, the roles of PLC and PKC in CCK-mediated anxiogenic effects have not been determined. We have shown previously that CCK facilitates glutamate release in the hippocampus especially at the synapses formed by the perforant path and dentate gyrus granule cells via activations of PLC and PKC. Here we further demonstrated that CCK enhanced NMDA receptor function in dentate gyrus granule cells via activation of PLC and PKC pathway. At the single-channel level, CCK increased NMDA single-channel open probability and mean open time, reduced the mean close time, and had no effects on the conductance of NMDA channels. Because elevation of glutamatergic functions results in anxiety, we explored the roles of PLC and PKC in CCK-induced anxiogenic actions using the Vogel Conflict Test (VCT). Our results from both pharmacological approach and knockout mice demonstrated that microinjection of CCK into the dentate gyrus concentration-dependently increased anxiety-like behavior via activation of PLC and PKC. Our results provide a novel unidentified signaling mechanism whereby CCK increases anxiety.
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Affiliation(s)
- Zhaoyang Xiao
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
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30
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Calábria LK, Peixoto PMV, Passos Lima AB, Peixoto LG, de Moraes VRA, Teixeira RR, Dos Santos CT, E Silva LO, da Silva MDFR, dos Santos AAD, Garcia-Cairasco N, Martins AR, Espreafico EM, Espindola FS. Myosins and DYNLL1/LC8 in the honey bee (Apis mellifera L.) brain. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:1300-1311. [PMID: 21718700 DOI: 10.1016/j.jinsphys.2011.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/09/2011] [Accepted: 06/10/2011] [Indexed: 05/31/2023]
Abstract
Honey bees have brain structures with specialized and developed systems of communication that account for memory, learning capacity and behavioral organization with a set of genes homologous to vertebrate genes. Many microtubule- and actin-based molecular motors are involved in axonal/dendritic transport. Myosin-Va is present in the honey bee Apis mellifera nervous system of the larvae and adult castes and subcastes. DYNLL1/LC8 and myosin-IIb, -VI and -IXb have also been detected in the adult brain. SNARE proteins, such as CaMKII, clathrin, syntaxin, SNAP25, munc18, synaptophysin and synaptotagmin, are also expressed in the honey bee brain. Honey bee myosin-Va displayed ATP-dependent solubility and was associated with DYNLL1/LC8 and SNARE proteins in the membrane vesicle-enriched fraction. Myosin-Va expression was also decreased after the intracerebral injection of melittin and NMDA. The immunolocalization of myosin-Va and -IV, DYNLL1/LC8, and synaptophysin in mushroom bodies, and optical and antennal lobes was compared with the brain morphology based on Neo-Timm histochemistry and revealed a distinct and punctate distribution. This result suggested that the pattern of localization is associated with neuron function. Therefore, our data indicated that the roles of myosins, DYNLL1/LC8, and SNARE proteins in the nervous and visual systems of honey bees should be further studied under different developmental, caste and behavioral conditions.
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Affiliation(s)
- Luciana Karen Calábria
- Institute of Genetics and Biochemistry, Federal University of Uberlandia, Uberlandia, MG, Brazil.
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31
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Bozic M, de Rooij J, Parisi E, Ortega MR, Fernandez E, Valdivielso JM. Glutamatergic signaling maintains the epithelial phenotype of proximal tubular cells. J Am Soc Nephrol 2011; 22:1099-111. [PMID: 21597037 DOI: 10.1681/asn.2010070701] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) contributes to the progression of renal tubulointerstitial fibrosis. The N-methyl-d-aspartate receptor (NMDAR), which is present in proximal tubular epithelium, is a glutamate receptor that acts as a calcium channel. Activation of NMDAR induces actin rearrangement in cells of the central nervous system, but whether it helps maintain the epithelial phenotype of the proximal tubule is unknown. Here, knockdown of NMDAR1 in a proximal tubule cell line (HK-2) induced changes in cell morphology, reduced E-cadherin expression, and increased α-SMA expression. Induction of EMT with TGF-β1 led to downregulation of both E-cadherin and membrane-associated β-catenin, reorganization of F-actin, expression of mesenchymal markers de novo, upregulation of Snail1, and increased cell migration; co-treatment with NMDA attenuated all of these changes. Furthermore, NMDA reduced TGF-β1-induced phosphorylation of Erk1/2 and Akt and the activation of Ras, suggesting that NMDA antagonizes TGF-β1-induced EMT by inhibiting the Ras-MEK pathway. In the unilateral ureteral obstruction model, treatment with NMDA blunted obstruction-induced upregulation of α-SMA, FSP1, and collagen I and downregulation of E-cadherin. Taken together, these results suggest that NMDAR plays a critical role in preserving the normal epithelial phenotype and modulating tubular EMT.
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Affiliation(s)
- Milica Bozic
- Nephrology Research Laboratory, IRB LLEIDA, University Hospital Arnau de Vilanova, Lleida, Spain
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32
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Lin YC, Koleske AJ. Mechanisms of synapse and dendrite maintenance and their disruption in psychiatric and neurodegenerative disorders. Annu Rev Neurosci 2011; 33:349-78. [PMID: 20367247 DOI: 10.1146/annurev-neuro-060909-153204] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Emerging evidence indicates that once established, synapses and dendrites can be maintained for long periods, if not for the organism's entire lifetime. In contrast to the wealth of knowledge regarding axon, dendrite, and synapse development, we understand comparatively little about the cellular and molecular mechanisms that enable long-term synapse and dendrite maintenance. Here, we review how the actin cytoskeleton and its regulators, adhesion receptors, and scaffolding proteins mediate synapse and dendrite maintenance. We examine how these mechanisms are reinforced by trophic signals passed between the pre- and postsynaptic compartments. We also discuss how synapse and dendrite maintenance mechanisms are compromised in psychiatric and neurodegenerative disorders.
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Affiliation(s)
- Yu-Chih Lin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8024, USA.
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33
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Peng Y, Zhao J, Gu QH, Chen RQ, Xu Z, Yan JZ, Wang SH, Liu SY, Chen Z, Lu W. Distinct trafficking and expression mechanisms underlie LTP and LTD of NMDA receptor-mediated synaptic responses. Hippocampus 2010; 20:646-58. [PMID: 19489005 DOI: 10.1002/hipo.20654] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Although an increasing number of studies have demonstrated the plasticity of NMDA receptor-mediated synaptic transmission, little is known about the molecular mechanisms that underlie this neurologically important process. In a study of NMDAR-mediated synaptic responses in hippocampal Schaffer-CA1 synapses whose AMPA receptor (AMPAR) activity is totally blocked, we uncovered differences between the trafficking mechanisms that underlie the long-term potentiation (LTP) and long-term depression (LTD) that can be induced in these cells under these conditions. The LTP-producing protocol failed to induce a change in the amplitude of NMDAR-mediated postsynaptic currents (NMDAR EPSCs) in the first 5-10 min, but induced gradual enhancement of NMDAR EPSCs thereafter that soon reached a stable magnitude. This "slow" LTP of NMDAR EPSCs (LTP(NMDA)) was blocked by inhibiting exocytosis or actin polymerization in postsynaptic cells. By contrast, LTD of NMDAR EPSCs (LTD(NMDA)) was immediately inducible, and, although it was blocked by the actin stabilizer, it was unaffected by exocytosis or endocytosis inhibitors. Furthermore, concomitant changes in the decay time of NMDAR EPSCs suggested that differential switches in NR2 subunit composition accompanied LTP(NMDA) and LTD(NMDA), and these changes were blocked by the calcium buffer BAPTA or an mGluR antagonist. Our results suggest that LTP(NMDA) and LTD(NMDA) utilize different NMDAR trafficking pathways and express different ratios of NMDAR subunits on the postsynaptic surface.
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Affiliation(s)
- Yi Peng
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
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Control of intracellular calcium signaling as a neuroprotective strategy. Molecules 2010; 15:1168-95. [PMID: 20335972 PMCID: PMC2847496 DOI: 10.3390/molecules15031168] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 02/05/2010] [Accepted: 03/02/2010] [Indexed: 12/13/2022] Open
Abstract
Both acute and chronic degenerative diseases of the nervous system reduce the viability and function of neurons through changes in intracellular calcium signaling. In particular, pathological increases in the intracellular calcium concentration promote such pathogenesis. Disease involvement of numerous regulators of intracellular calcium signaling located on the plasma membrane and intracellular organelles has been documented. Diverse groups of chemical compounds targeting ion channels, G-protein coupled receptors, pumps and enzymes have been identified as potential neuroprotectants. The present review summarizes the discovery, mechanisms and biological activity of neuroprotective molecules targeting proteins that control intracellular calcium signaling to preserve or restore structure and function of the nervous system. Disease relevance, clinical applications and new technologies for the identification of such molecules are being discussed.
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35
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Vazhappilly R, Wee KSL, Sucher NJ, Low CM. A non-muscle myosin II motor links NR1 to retrograde trafficking and proteasomal degradation in PC12 cells. Neurochem Int 2010; 56:569-76. [PMID: 20064569 DOI: 10.1016/j.neuint.2009.12.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 12/24/2009] [Accepted: 12/31/2009] [Indexed: 10/20/2022]
Abstract
Rat pheochromocytoma (PC12) cells have been shown to lack functional NMDA receptors; yet, these cells express NR1 subunits of the NMDA receptor. The reason for the lack of functional receptors has been attributed to the absence of significant levels of NR2 subunits to co-assemble with NR1. It is known that PC12 expresses very low levels of NR2C, with complete absence of other types of NR2 subunits. The purpose of the present study is to describe the molecular mechanism of trafficking and degradation of unassembled NR1 subunits in PC12 cells. The localization of NR1 subunits in PC12 cells were evaluated by immunofluorescence and co-immunoprecipitation, which showed that NR1 was present in the endoplasmic reticulum and cis-middle compartments of the Golgi apparatus. Upon treatment with a proteasome inhibitor, MG132, the ubiquitinylated species of NR1 subunit were detected, suggesting that NR1 is being targeted for endoplasmic reticulum-associated proteasomal degradation. Our previous studies suggest that NR1 subunits from the Golgi do not proceed to trans-Golgi, hence they will require re-routing to the endoplasmic reticulum for degradation. Further investigations on the factors involved in the trafficking of NR1 from Golgi to endoplasmic reticulum were performed using co-immunoprecipitation and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. These revealed the co-association of NR1 with non-muscle myosin heavy chain II isoforms A and B. We also demonstrate the functional significance of this interaction through the use of a myosin inhibitor, blebbistatin, to disrupt brefeldin A-induced Golgi-to-endoplasmic reticulum trafficking of NR1. In conclusion, our results suggest that non-muscle myosin II is involved in the retrograde trafficking of NR1 subunits from the cis/middle-Golgi to the endoplasmic reticulum for proteasomal degradation in PC12.
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Affiliation(s)
- Rema Vazhappilly
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Republic of Singapore
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36
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Gisselsson L, Toresson H, Ruscher K, Wieloch T. Rho kinase inhibition protects CA1 cells in organotypic hippocampal slices during in vitro ischemia. Brain Res 2009; 1316:92-100. [PMID: 20026316 DOI: 10.1016/j.brainres.2009.11.087] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 11/23/2009] [Indexed: 01/24/2023]
Abstract
The actin cytoskeleton is a dynamic superstructure that regulates multiple cellular functions and that has been implicated in cell death regulation. We investigated whether modulating the neuronal actin cytoskeleton polymerization by Rho-GTPase kinase (ROCK) inhibition influences cell death in hippocampal neuronal cultures and in murine organotypic hippocampal slice cultures subjected to in vitro ischemia (IVI). During IVI, spines on vehicle treated hippocampal neurons collapsed and large dendritic actin aggregates were formed. Following ROCK inhibition by Y27632, the actin aggregates were markedly smaller while large filopodia extended from the dendritic trunk. Y27632 also provided strong neuroprotection of hippocampal pyramidal CA1 neurons, which was of similar magnitude as protection by NMDA receptor blockade. Likewise, treatment with the F-actin depolymerizing agent latrunculin during IVI diminished actin aggregation and mitigated cell death following IVI. We propose that ROCK inhibition protects neurons against ischemic damage by disrupting actin polymerization thereby mitigating NMDA receptor induced toxicity and releasing ATP bound to actin for cellular energy use. We conclude that ROCK inhibitors abrogate multiple detrimental processes and could therefore be useful in stroke therapy.
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Affiliation(s)
- Lennart Gisselsson
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184 Lund, Sweden
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37
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Bajaj G, Zhang Y, Schimerlik MI, Hau AM, Yang J, Filtz TM, Kioussi C, Ishmael JE. N-methyl-D-aspartate receptor subunits are non-myosin targets of myosin regulatory light chain. J Biol Chem 2009; 284:1252-66. [PMID: 18945678 PMCID: PMC2613636 DOI: 10.1074/jbc.m801861200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 10/07/2008] [Indexed: 12/29/2022] Open
Abstract
Excitatory synapses contain multiple members of the myosin superfamily of molecular motors for which functions have not been assigned. In this study we characterized the molecular determinants of myosin regulatory light chain (RLC) binding to two major subunits of the N-methyl-d-aspartate receptor (NR). Myosin RLC bound to NR subunits in a manner that could be distinguished from the interaction of RLC with the neck region of non-muscle myosin II-B (NMII-B) heavy chain; NR-RLC interactions did not require the addition of magnesium, were maintained in the absence of the fourth EF-hand domain of the light chain, and were sensitive to RLC phosphorylation. Equilibrium fluorescence spectroscopy experiments indicate that the affinity of myosin RLC for NR1 is high (30 nm) in the context of the isolated light chain. Binding was not favored in the context of a recombinant NMII-B subfragment one, indicating that if the RLC is already bound to NMII-B it is unlikely to form a bridge between two binding partners. We report that sequence similarity in the "GXXXR" portion of the incomplete IQ2 motif found in NMII heavy chain isoforms likely contributes to recognition of NR2A as a non-myosin target of the RLC. Using site-directed mutagenesis to disrupt NR2A-RLC binding in intact cells, we find that RLC interactions facilitate trafficking of NR1/NR2A receptors to the cell membrane. We suggest that myosin RLC can adopt target-dependent conformations and that a role for this light chain in protein trafficking may be independent of the myosin II complex.
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Affiliation(s)
- Gaurav Bajaj
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97331, USA
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Beazely MA, Weerapura M, MacDonald JF. Abelson tyrosine kinase links PDGFbeta receptor activation to cytoskeletal regulation of NMDA receptors in CA1 hippocampal neurons. Mol Brain 2008; 1:20. [PMID: 19077273 PMCID: PMC2651131 DOI: 10.1186/1756-6606-1-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 12/12/2008] [Indexed: 01/12/2023] Open
Abstract
Background We have previously demonstrated that PDGF receptor activation indirectly inhibits N-methyl-D-aspartate (NMDA) currents by modifying the cytoskeleton. PDGF receptor ligand is also neuroprotective in hippocampal slices and cultured neurons. PDGF receptors are tyrosine kinases that control a variety of signal transduction pathways including those mediated by PLCγ. In fibroblasts Src and another non-receptor tyrosine kinase, Abelson kinase (Abl), control PDGF receptor regulation of cytoskeletal dynamics. The mechanism whereby PDGF receptor regulates cytoskeletal dynamics in central neurons remains poorly understood. Results Intracellular applications of active Abl, but not heat-inactivated Abl, decreased NMDA-evoked currents in isolated hippocampal neurons. This mimics the effects of PDGF receptor activation in these neurons. The Abl kinase inhibitor, STI571, blocked the inhibition of NMDA currents by Abl. We demonstrate that PDGF receptors can activate Abl kinase in hippocampal neurons via mechanisms similar to those observed previously in fibroblasts. Furthermore, PDGFβ receptor activation alters the subcellular localization of Abl. Abl kinase is linked to actin cytoskeletal dynamics in many systems. We show that the inhibition of NMDA receptor currents by Abl kinase is blocked by the inclusion of the Rho kinase inhibitor, Y-27632, and that activation of Abl correlates with an increase in ROCK tyrosine phosphorylation. Conclusion This study demonstrates that PDGFβ receptors act via an interaction with Abl kinase and Rho kinase to regulated cytoskeletal regulation of NMDA receptor channels in CA1 pyramidal neurons.
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Actin depolymerization contributes to ethanol inhibition of NMDA receptors in primary cultured cerebellar granule cells. Alcohol 2008; 42:525-39. [PMID: 18789629 DOI: 10.1016/j.alcohol.2008.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 06/18/2008] [Accepted: 06/19/2008] [Indexed: 11/22/2022]
Abstract
We have previously reported that a 30s ethanol (10 and 100mM) pre-exposure significantly enhanced EtOH inhibition of N-methyl-d-aspartate (NMDA-induced currents)-induced peak currents in primary cultured cerebellar granule cells (CGCs). The purpose of this study was to determine if intracellular factors play a role in ethanol pre-exposure-enhanced inhibition of NMDA-induced currents and if so, to identify the intracellular target(s) mediating this effect. Ethanol pre-exposure-enhanced inhibition was reduced when ethanol was present intracellularly prior to the initiation of the pretreatment protocol. Similar to results acquired with the whole-cell configuration, ethanol pre-exposure-enhanced inhibition of NMDA-induced currents was also observed in the perforated patch-clamp mode. Collectively, these results suggest an intracellular target not easily dialyzed from the cell. Perturbation of the actin cytoskeleton was responsible for the ethanol pre-exposure-enhanced inhibition of NMDA-induced currents was supported by the observation that the intracellular presence of the actin stabilizer phalloidin prevented ethanol pre-exposure-enhanced inhibition. Similar to the effects of ethanol, the depolymerizing agent latrunculin A inhibited NMDA-induced currents after a 30s pretreatment exposure with full recovery of receptor function after washout of the drug. Furthermore, latrunculin A occluded the enhanced inhibition of NMDA-induced currents by ethanol pre-exposure for both 10 and 100mM ethanol. The microtubule depolymerizing agent taxol had no affect on ethanol pretreatment-enhanced inhibition of NMDA-induced currents. Confocal microscopy with phalloidin-FITC indicated that F-actin filaments in neurites were depolymerized after a 30s treatment of either latrunculin A or 100mM ethanol. Our observations indicate that ethanol inhibition of NMDAR function may involve perturbation of the actin cytoskeleton.
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Srinivasan G, Kim JH, von Gersdorff H. The pool of fast releasing vesicles is augmented by myosin light chain kinase inhibition at the calyx of Held synapse. J Neurophysiol 2008; 99:1810-24. [PMID: 18256166 DOI: 10.1152/jn.00949.2007] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Synaptic strength is determined by release probability and the size of the readily releasable pool of docked vesicles. Here we describe the effects of blocking myosin light chain kinase (MLCK), a cytoskeletal regulatory protein thought to be involved in myosin-mediated vesicle transport, on synaptic transmission at the mouse calyx of Held synapse. Application of three different MLCK inhibitors increased the amplitude of the early excitatory postsynaptic currents (EPSCs) in a stimulus train, without affecting the late steady-state EPSCs. A presynaptic locus of action for MLCK inhibitors was confirmed by an increase in the frequency of miniature EPSCs that left their average amplitude unchanged. MLCK inhibition did not affect presynaptic Ca(2+) currents or action potential waveform. Moreover, Ca(2+) imaging experiments showed that [Ca(2+)](i) transients elicited by 100-Hz stimulus trains were not altered by MLCK inhibition. Studies using high-frequency stimulus trains indicated that MLCK inhibitors increase vesicle pool size, but do not significantly alter release probability. Accordingly, when AMPA-receptor desensitization was minimized, EPSC paired-pulse ratios were unaltered by MLCK inhibition, suggesting that release probability remains unaltered. MLCK inhibition potentiated EPSCs even when presynaptic Ca(2+) buffering was greatly enhanced by treating slices with EGTA-AM. In addition, MLCK inhibition did not affect the rate of recovery from short-term depression. Finally, developmental studies revealed that EPSC potentiation by MLCK inhibition starts at postnatal day 5 (P5) and remains strong during synaptic maturation up to P18. Overall, our data suggest that MLCK plays a crucial role in determining the size of the pool of synaptic vesicles that undergo fast release at a CNS synapse.
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Affiliation(s)
- Geetha Srinivasan
- The Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
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41
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Kioussi C, Appu M, Löhr CV, Fischer KA, Bajaj G, Leid M, Ishmael JE. Co-expression of myosin II regulatory light chain and the NMDAR1 subunit in neonatal and adult mouse brain. Brain Res Bull 2007; 74:439-51. [DOI: 10.1016/j.brainresbull.2007.07.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 07/12/2007] [Indexed: 01/26/2023]
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Cantiello HF, Montalbetti N, Li Q, Chen XZ. The Cytoskeletal Connection to Ion Channels as a Potential Mechanosensory Mechanism: Lessons from Polycystin-2 (TRPP2). CURRENT TOPICS IN MEMBRANES 2007; 59:233-96. [PMID: 25168140 DOI: 10.1016/s1063-5823(06)59010-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mechanosensitivity of ion channels, or the ability to transfer mechanical forces into a gating mechanism of channel regulation, is split into two main working (not mutually exclusive) hypotheses. One is that elastic and/or structural changes in membrane properties act as a transducing mechanism of channel regulation. The other hypothesis involves tertiary elements, such as the cytoskeleton which, itself by dynamic interactions with the ion channel, may convey conformational changes, including those ascribed to mechanical forces. This hypothesis is supported by numerous instances of regulatory changes in channel behavior by alterations in cytoskeletal structures/interactions. However, only recently, the molecular nature of these interactions has slowly emerged. Recently, a surge of evidence has emerged to indicate that transient receptor potential (TRP) channels are key elements in the transduction of a variety of environmental signals. This chapter describes the molecular linkage and regulatory elements of polycystin-2 (PC2), a TRP-type (TRPP2) nonselective cation channel whose mutations cause autosomal dominant polycystic kidney disease (ADPKD). The chapter focuses on the involvement of cytoskeletal structures in the regulation of PC2 and discusses how these connections are the transducing mechanism of environmental signals to its channel function.
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Affiliation(s)
- Horacio F Cantiello
- Renal Unit, Massachusetts General Hospital East, Charlestown, Massachusetts 02129; Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115; Laboratorio de Canales Iónicos, Departamento de Fisicoquímica y Química Analítica, Facultad de Farmacia y Bioquímica, Buenos Aires 1113, Argentina
| | - Nicolás Montalbetti
- Laboratorio de Canales Iónicos, Departamento de Fisicoquímica y Química Analítica, Facultad de Farmacia y Bioquímica, Buenos Aires 1113, Argentina
| | - Qiang Li
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
| | - Xing-Zhen Chen
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
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43
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MacDonald JF, Jackson MF, Beazely MA. G protein-coupled receptors control NMDARs and metaplasticity in the hippocampus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:941-51. [PMID: 17261268 DOI: 10.1016/j.bbamem.2006.12.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Revised: 12/06/2006] [Accepted: 12/09/2006] [Indexed: 11/20/2022]
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are the major forms of functional synaptic plasticity observed at CA1 synapses of the hippocampus. The balance between LTP and LTD or "metaplasticity" is controlled by G-protein coupled receptors (GPCRs) whose signal pathways target the N-methyl-D-asparate (NMDA) subtype of excitatory glutamate receptor. We discuss the protein kinase signal cascades stimulated by Galphaq and Galphas coupled GPCRs and describe how control of NMDAR activity shifts the threshold for the induction of LTP.
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Affiliation(s)
- John F MacDonald
- Department of Physiology, University of Toronto, Toronto, ON, Canada.
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Ishmael JE, Safic M, Amparan D, Vogel WK, Pham T, Marley K, Filtz TM, Maier CS. Nonmuscle myosins II-B and Va are components of detergent-resistant membrane skeletons derived from mouse forebrain. Brain Res 2007; 1143:46-59. [PMID: 17321505 DOI: 10.1016/j.brainres.2007.01.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 01/14/2007] [Accepted: 01/16/2007] [Indexed: 10/23/2022]
Abstract
Myosins are actin-based molecular motors that may have specialized trafficking and contractile functions in cytoskeletal compartments that lack microtubules. The postsynaptic excitatory synapse is one such specialization, yet little is known about the spatial organization of myosin motor proteins in the mature brain. We used a proteomics approach to determine if class II and class V myosin isoforms are associated with Triton X-100-resistant membranes isolated from mouse forebrain. Two nonmuscle myosin isoforms (II-B and Va), were identified as components of lipid raft fractions that also contained typical membrane skeletal proteins such as non-erythrocyte spectrins, actin, alpha-actinin-2 and tubulin subunits. Other raft-associated proteins included lipid raft markers, proteins involved in cell adhesion and membrane dynamics, receptors and channels including glutamate receptor subunits, scaffolding and regulatory proteins. Myosin II-B and Va were also present in standard postsynaptic density (PSD) fractions, however retention of myosin II-B was strongly influenced by ATP status. If homogenates were supplemented with ATP, myosin II-B could be extracted from PSD I whereas myosin Va and other postsynaptic proteins were resistant to extraction. In summary, both myosin isoforms are components of a raft-associated membrane skeleton and are likely detected in standard PSD fractions as a result of their intrinsic ability to form actomyosin. Myosin II-B, however, is more loosely associated with PSD fractions than myosin Va, which appears to be a core PSD protein.
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Affiliation(s)
- Jane E Ishmael
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97331, USA.
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45
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Lamprecht R, Margulies DS, Farb CR, Hou M, Johnson LR, LeDoux JE. Myosin light chain kinase regulates synaptic plasticity and fear learning in the lateral amygdala. Neuroscience 2006; 139:821-9. [PMID: 16515842 DOI: 10.1016/j.neuroscience.2005.12.055] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 12/18/2005] [Accepted: 12/22/2005] [Indexed: 01/29/2023]
Abstract
Learning and memory depend on signaling molecules that affect synaptic efficacy. The cytoskeleton has been implicated in regulating synaptic transmission but its role in learning and memory is poorly understood. Fear learning depends on plasticity in the lateral nucleus of the amygdala. We therefore examined whether the cytoskeletal-regulatory protein, myosin light chain kinase, might contribute to fear learning in the rat lateral amygdala. Microinjection of ML-7, a specific inhibitor of myosin light chain kinase, into the lateral nucleus of the amygdala before fear conditioning, but not immediately afterward, enhanced both short-term memory and long-term memory, suggesting that myosin light chain kinase is involved specifically in memory acquisition rather than in posttraining consolidation of memory. Myosin light chain kinase inhibitor had no effect on memory retrieval. Furthermore, ML-7 had no effect on behavior when the training stimuli were presented in a non-associative manner. Anatomical studies showed that myosin light chain kinase is present in cells throughout lateral nucleus of the amygdala and is localized to dendritic shafts and spines that are postsynaptic to the projections from the auditory thalamus to lateral nucleus of the amygdala, a pathway specifically implicated in fear learning. Inhibition of myosin light chain kinase enhanced long-term potentiation, a physiological model of learning, in the auditory thalamic pathway to the lateral nucleus of the amygdala. When ML-7 was applied without associative tetanic stimulation it had no effect on synaptic responses in lateral nucleus of the amygdala. Thus, myosin light chain kinase activity in lateral nucleus of the amygdala appears to normally suppress synaptic plasticity in the circuits underlying fear learning, suggesting that myosin light chain kinase may help prevent the acquisition of irrelevant fears. Impairment of this mechanism could contribute to pathological fear learning.
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Affiliation(s)
- R Lamprecht
- W. M. Keck Foundation Laboratory for Neurobiology, Center for Neural Science, New York University, 4 Washington Place, Room 809, New York, NY 10003, USA.
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Akopian A, Szikra T, Cristofanilli M, Krizaj D. Glutamate-induced Ca2+ influx in third-order neurons of salamander retina is regulated by the actin cytoskeleton. Neuroscience 2005; 138:17-24. [PMID: 16359816 PMCID: PMC2927977 DOI: 10.1016/j.neuroscience.2005.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Revised: 09/22/2005] [Accepted: 11/01/2005] [Indexed: 11/20/2022]
Abstract
Ligand-gated ion channels (ionotropic receptors) link to the cortical cytoskeleton via specialized scaffold proteins and thereby to appropriate signal transduction pathways in the cell. We studied the role of filamentous actin in the regulation of Ca influx through glutamate receptor-activated channels in third-order neurons of salamander retina. Staining by Alexa-Fluor 488-phalloidin, to visualize polymerized actin, we show localization of filamentous actin in neurites, and the membrane surrounding the cell soma. With Ca(2+) imaging we found that in dissociated neurons, depolymerization of filamentous actin by latrunculin A, or cytochalasin D significantly reduced glutamate-induced intracellular Ca(2+) accumulation to 53+/-7% of control value. Jasplakinolide, a stabilizer of filamentous actin, by itself slightly increased the glutamate-induced Ca(2+) signal and completely attenuated the inhibitory effect when applied in combination with actin depolymerizing agents. These results indicate that in salamander retinal neurons the actin cytoskeleton regulates Ca(2+) influx through ionotropic glutamate receptor-activated channels, suggesting regulatory roles for filamentous actin in a number of Ca(2+)-dependent physiological and pathological processes.
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Affiliation(s)
- A Akopian
- Department of Ophthalmology, NYU School of Medicine, New York, NY 10016, USA.
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47
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YOKOMAKU D, JOURDI H, KAKITA A, NAGANO T, TAKAHASHI H, TAKEI N, NAWA H. ErbB1 receptor ligands attenuate the expression of synaptic scaffolding proteins, GRIP1 and SAP97, in developing neocortex. Neuroscience 2005; 136:1037-47. [PMID: 16226841 PMCID: PMC3659789 DOI: 10.1016/j.neuroscience.2005.08.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 07/23/2005] [Accepted: 08/04/2005] [Indexed: 01/01/2023]
Abstract
Scaffolding proteins containing postsynaptic density-95/discs large/zone occludens-1 (PDZ) domains interact with synaptic receptors and cytoskeletal components and are therefore implicated in synaptic development and plasticity. Little is known, however, about what regulates the expression of PDZ proteins and how the levels of these proteins influence synaptic development. Here, we show that ligands for epidermal growth factor receptors (ErbB1) decrease a particular set of PDZ proteins and negatively influence synaptic formation or maturation. In short-term neocortical cultures, concentrations of epidermal growth factor and amphiregulin (2-9 pM) decreased the expression of glutamate receptor interacting protein 1 (GRIP1) and synapse-associated protein 97 kDa (SAP97) without affecting postsynaptic density-95 (PSD-95) levels and glial proliferation. In long-term cultures, epidermal growth factor treatment resulted in a decrease in the frequency of pan-PDZ-immunoreactive aggregates on dendritic processes. A similar activity on the same PDZ proteins was observed in the developing neocortex following epidermal growth factor administration to rat neonates. Immunoblotting revealed that administered epidermal growth factor from the periphery activated brain ErbB1 receptors and decreased GRIP1 and SAP97 protein levels in the neocortex. Laser-confocal imaging indicated that epidermal growth factor administration suppressed the formation of pan-PDZ-immunoreactive puncta and dispersed those structures in vivo as well. These findings revealed a novel negative activity of ErbB1 receptor ligands that attenuates the expression of the PDZ proteins and inhibits postsynaptic maturation in developing neocortex.
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Affiliation(s)
- D. YOKOMAKU
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - H. JOURDI
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - A. KAKITA
- Brain Resource Center, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - T. NAGANO
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - H. TAKAHASHI
- Department of Pathology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - N. TAKEI
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - H. NAWA
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
- Corresponding author. Fax: +81-25-227-0815. (H. Nawa)
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48
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Morishita W, Marie H, Malenka RC. Distinct triggering and expression mechanisms underlie LTD of AMPA and NMDA synaptic responses. Nat Neurosci 2005; 8:1043-50. [PMID: 16025109 DOI: 10.1038/nn1506] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Accepted: 06/24/2005] [Indexed: 02/07/2023]
Abstract
Although long-term depression (LTD) of AMPA receptor-mediated postsynaptic currents (AMPAR EPSCs) has been extensively examined, little is known about the mechanisms responsible for LTD of NMDA receptor (NMDAR)-mediated EPSCs. Here we show differences in the intracellular signaling cascades that mediate LTD of AMPAR EPSCs versus NMDAR EPSCs in rat hippocampus. Both forms of LTD were blocked by inhibitors of protein phosphatase 1, but only LTD of AMPAR EPSCs was affected by inhibition of calcineurin. Notably, in contrast to LTD of AMPAR EPSCs, LTD of NMDAR EPSCs was unaffected by endocytosis inhibitors. A role for calcium-dependent actin depolymerization in LTD of NMDAR EPSCs was supported by the findings that the actin stabilizer phalloidin and a cofilin inhibitory peptide each blocked LTD of NMDAR EPSCs but not AMPAR EPSCs. These results suggest that the same pattern of afferent activity elicits depression of AMPAR- and NMDAR-mediated synaptic responses by means of distinct triggering and expression mechanisms.
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Affiliation(s)
- Wade Morishita
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 1201 Welch Rd., Palo Alto, California 94304, USA
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49
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Amparan D, Avram D, Thomas CG, Lindahl MG, Yang J, Bajaj G, Ishmael JE. Direct interaction of myosin regulatory light chain with the NMDA receptor. J Neurochem 2005; 92:349-61. [PMID: 15663482 DOI: 10.1111/j.1471-4159.2004.02869.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
NMDA receptors interact with a variety of intracellular proteins at excitatory synapses. In this paper we show that myosin regulatory light chain (RLC) isolated from mouse brain is a NMDA receptor-interacting protein. Myosin RLC bound directly to the C-termini of both NMDA receptor 1 (NR1) and NMDA receptor 2 (NR2) subunits, rendering the interaction of myosin RLC with NMDA receptors distinct from that of calmodulin which is considered a NR1-interacting protein. Myosin RLC co-localized with NR1 in the dendritic spines of isolated hippocampal neurons, and was co-immunoprecipitated from brain extracts in a complex with NR1, NR2A, NR2B, PSD-95, Adaptor protein-2 and myosin II heavy chain. The C0 region of NR1 was necessary and sufficient for binding myosin RLC. Ca2+/calmodulin, but not calmodulin alone, displaced recombinant myosin RLC from the carboxy tail of NR1 indicating that myosin RLC and Ca2+/calmodulin can compete for a common binding site on NR1 in vitro. Myosin RLC is the only known substrate for myosin regulatory light chain kinase, which has recently been shown to modulate NMDA receptor function in isolated hippocampal neurons. Our results suggest that an additional level of NMDA receptor regulation may be mediated via a direct interaction with a light chain of myosin II. Thus, myosin RLC-NMDA receptor interactions may contribute to the contractile and motile forces that are placed upon NMDA receptor subunits during changes associated with synaptic plasticity and neural morphogenesis.
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Affiliation(s)
- David Amparan
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, USA
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50
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Conway AM, James AB, O'Kane EM, Rakhit S, Morris BJ. Regulation of myosin light chain phosphorylation by RhoB in neuronal cells. Exp Cell Res 2004; 300:35-42. [PMID: 15383312 DOI: 10.1016/j.yexcr.2004.06.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Revised: 06/16/2004] [Indexed: 11/26/2022]
Abstract
The phosphorylation of myosin light chain (MLC) is a key regulatory point in the control of cellular morphology. Evidence suggests that RhoA-a member of the Rho GTPase family-regulates MLC phosphorylation via Rho kinase (ROK). Neurones display subtle alterations in their cytoarchitecture during the synaptic plasticity following high-frequency stimulation. We have recently demonstrated that RhoB, and not RhoA, is activated in neurones by high-frequency stimulation. However, the downstream consequences of RhoB activation in cells are unclear. In this study, we tested the hypothesis that RhoB might stimulate neuronal MLC phosphorylation. Transfection of PC12 cells with constitutively active RhoB increased MLC phosphorylation. Conversely, dominant-negative RhoB vectors reduced MLC phosphorylation. The effect of RhoB was attenuated by pretreatment with a selective ROK inhibitor. This confirms that Rho GTPases are important regulators of MLC phosphorylation, but suggests that, in neuronal cells, the control is exerted via RhoB rather than RhoA.
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Affiliation(s)
- A-M Conway
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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