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  1. Article ; Online: Mechanisms underlying NMDA receptor synaptic/extrasynaptic distribution and function.

    Gladding, Clare M / Raymond, Lynn A

    Molecular and cellular neurosciences

    2011  Volume 48, Issue 4, Page(s) 308–320

    Abstract: Research over the last few decades has shaped our understanding of the crucial involvement of the N-methyl-D-aspartate receptor (NMDAR) in mediating excitatory synaptic neurotransmission, neuronal development and learning and memory. The complexity of ... ...

    Abstract Research over the last few decades has shaped our understanding of the crucial involvement of the N-methyl-D-aspartate receptor (NMDAR) in mediating excitatory synaptic neurotransmission, neuronal development and learning and memory. The complexity of NMDAR modulation has escalated with the knowledge that receptors can traffic between synaptic and extrasynaptic sites, and that location on the plasma membrane profoundly affects the physiological function of NMDARs. Moreover, mechanisms that regulate NMDAR subcellular localization and function, such as protein-protein interactions, phosphorylation, palmitoylation, ubiquitination and receptor proteolytic cleavage, may differ for synaptic and extrasynaptic NMDARs. Recent studies suggest that NMDAR mislocalization is a dominant contributing factor to glutamatergic dysfunction and pathogenesis in neurological disorders such as Huntington's disease, Alzheimer's disease and ischemia. Therapeutic approaches that specifically rectify receptor mislocalization or target resulting downstream apoptotic signaling could be beneficial for preventing disease onset or progression across many disorders that are commonly caused by NMDAR dysfunction. This review will summarize the molecular mechanisms that regulate synaptic and extrasynaptic NMDAR localization in both physiologic and pathogenic states.
    MeSH term(s) Animals ; Models, Biological ; Receptors, N-Methyl-D-Aspartate/physiology ; Signal Transduction/physiology ; Synapses/physiology ; Synaptic Transmission/physiology
    Chemical Substances Receptors, N-Methyl-D-Aspartate
    Language English
    Publishing date 2011-12
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 1046640-x
    ISSN 1095-9327 ; 1044-7431
    ISSN (online) 1095-9327
    ISSN 1044-7431
    DOI 10.1016/j.mcn.2011.05.001
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Chronic blockade of extrasynaptic NMDA receptors ameliorates synaptic dysfunction and pro-death signaling in Huntington disease transgenic mice.

    Dau, Alejandro / Gladding, Clare M / Sepers, Marja D / Raymond, Lynn A

    Neurobiology of disease

    2014  Volume 62, Page(s) 533–542

    Abstract: In the YAC128 mouse model of Huntington disease (HD), elevated extrasynaptic NMDA receptor (Ex-NMDAR) expression contributes to the onset of striatal dysfunction and atrophy. A shift in the balance of synaptic-extrasynaptic NMDAR signaling and ... ...

    Abstract In the YAC128 mouse model of Huntington disease (HD), elevated extrasynaptic NMDA receptor (Ex-NMDAR) expression contributes to the onset of striatal dysfunction and atrophy. A shift in the balance of synaptic-extrasynaptic NMDAR signaling and localization is paralleled by early stage dysregulation of intracellular calcium signaling pathways, including calpain and p38 MAPK activation, that couple to pro-death cascades. However, whether aberrant calcium signaling is a consequence of elevated Ex-NMDAR expression in HD is unknown. Here, we aimed to identify calcium-dependent pathways downstream of Ex-NMDARs in HD. Chronic (2-month) treatment of YAC128 and WT mice with memantine (1 and 10mg/kg/day), which at a low dose selectively blocks Ex-NMDARs, reduced striatal Ex-NMDAR expression and current in 4-month old YAC128 mice without altering synaptic NMDAR levels. In contrast, calpain activity was not affected by memantine treatment, and was elevated in untreated YAC128 mice at 1.5months but not 4months of age. In YAC128 mice, memantine at 1mg/kg/day rescued CREB shut-off, while both doses suppressed p38 MAPK activation to WT levels. Taken together, our results indicate that Ex-NMDAR activity perpetuates increased extrasynaptic NMDAR expression and drives dysregulated p38 MAPK and CREB signaling in YAC128 mice. Elucidation of the pathways downstream of Ex-NMDARs in HD could help provide novel therapeutic targets for this disease.
    MeSH term(s) Animals ; CREB-Binding Protein/metabolism ; Calcium Signaling ; Calpain/metabolism ; Corpus Striatum/drug effects ; Corpus Striatum/enzymology ; Corpus Striatum/metabolism ; Excitatory Amino Acid Antagonists/pharmacology ; Huntington Disease/genetics ; Huntington Disease/metabolism ; Memantine/pharmacology ; Mice ; Mice, Transgenic ; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors ; Receptors, N-Methyl-D-Aspartate/metabolism ; Synapses/drug effects ; Synapses/metabolism ; p38 Mitogen-Activated Protein Kinases/metabolism
    Chemical Substances Excitatory Amino Acid Antagonists ; Receptors, N-Methyl-D-Aspartate ; CREB-Binding Protein (EC 2.3.1.48) ; Crebbp protein, mouse (EC 2.3.1.48) ; p38 Mitogen-Activated Protein Kinases (EC 2.7.11.24) ; Calpain (EC 3.4.22.-) ; Memantine (W8O17SJF3T)
    Language English
    Publishing date 2014-02
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1211786-9
    ISSN 1095-953X ; 0969-9961
    ISSN (online) 1095-953X
    ISSN 0969-9961
    DOI 10.1016/j.nbd.2013.11.013
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Metabotropic glutamate receptor-mediated long-term depression: molecular mechanisms.

    Gladding, Clare M / Fitzjohn, Stephen M / Molnár, Elek

    Pharmacological reviews

    2009  Volume 61, Issue 4, Page(s) 395–412

    Abstract: The ability to modify synaptic transmission between neurons is a fundamental process of the nervous system that is involved in development, learning, and disease. Thus, synaptic plasticity is the ability to bidirectionally modify transmission, where long- ...

    Abstract The ability to modify synaptic transmission between neurons is a fundamental process of the nervous system that is involved in development, learning, and disease. Thus, synaptic plasticity is the ability to bidirectionally modify transmission, where long-term potentiation and long-term depression (LTD) represent the best characterized forms of plasticity. In the hippocampus, two main forms of LTD coexist that are mediated by activation of either N-methyl-d-aspartic acid receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). Compared with NMDAR-LTD, mGluR-LTD is less well understood, but recent advances have started to delineate the underlying mechanisms. mGluR-LTD at CA3:CA1 synapses in the hippocampus can be induced either by synaptic stimulation or by bath application of the group I selective agonist (R,S)-3,5-dihydroxyphenylglycine. Multiple signaling mechanisms have been implicated in mGluR-LTD, illustrating the complexity of this form of plasticity. This review provides an overview of recent studies investigating the molecular mechanisms underlying hippocampal mGluR-LTD. It highlights the role of key molecular components and signaling pathways that are involved in the induction and expression of mGluR-LTD and considers how the different signaling pathways may work together to elicit a persistent reduction in synaptic transmission.
    MeSH term(s) Animals ; Excitatory Amino Acid Agonists/pharmacology ; Humans ; Long-Term Synaptic Depression/drug effects ; Long-Term Synaptic Depression/physiology ; Neurons/drug effects ; Neurons/metabolism ; Receptors, Metabotropic Glutamate/genetics ; Receptors, Metabotropic Glutamate/metabolism ; Receptors, Metabotropic Glutamate/physiology
    Chemical Substances Excitatory Amino Acid Agonists ; Receptors, Metabotropic Glutamate
    Language English
    Publishing date 2009-11-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 209898-2
    ISSN 1521-0081 ; 0031-6997
    ISSN (online) 1521-0081
    ISSN 0031-6997
    DOI 10.1124/pr.109.001735
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Small organic molecule disruptors of Cav3.2 - USP5 interactions reverse inflammatory and neuropathic pain.

    Gadotti, Vinicius M / Caballero, Agustin Garcia / Berger, N Daniel / Gladding, Clare M / Chen, Lina / Pfeifer, Tom A / Zamponi, Gerald W

    Molecular pain

    2015  Volume 11, Page(s) 12

    Abstract: Background: Cav3.2 channels facilitate nociceptive transmission and are upregulated in DRG neurons in response to nerve injury or peripheral inflammation. We reported that this enhancement of Cav3.2 currents in afferent neurons is mediated by ... ...

    Abstract Background: Cav3.2 channels facilitate nociceptive transmission and are upregulated in DRG neurons in response to nerve injury or peripheral inflammation. We reported that this enhancement of Cav3.2 currents in afferent neurons is mediated by deubiquitination of the channels by the deubiquitinase USP5, and that disrupting USP5/Cav3.2 channel interactions protected from inflammatory and neuropathic pain.
    Results: Here we describe the development of a small molecule screening assay for USP5-Cav3.2 disruptors, and report on two hits of a ~5000 compound screen - suramin and the flavonoid gossypetin. In mouse models of inflammatory pain and neuropathic pain, both suramin and gossypetin produced dose-dependent and long-lasting mechanical anti-hyperalgesia that was abolished or greatly attenuated in Cav3.2 null mice. Suramin and Cav3.2/USP5 Tat-disruptor peptides were also tested in models of diabetic neuropathy and visceral pain, and provided remarkable protection.
    Conclusions: Overall, our findings provide proof of concept for a new class of analgesics that target T-type channel deubiquitination.
    MeSH term(s) Analgesics/pharmacology ; Animals ; Calcium Channels, T-Type/metabolism ; Ganglia, Spinal/physiopathology ; Humans ; Hyperalgesia/metabolism ; Hyperalgesia/physiopathology ; Inflammation/metabolism ; Mice ; Mice, Knockout ; Neuralgia/metabolism ; Neuralgia/physiopathology ; Neurons, Afferent/metabolism ; Suramin/pharmacology ; Ubiquitin-Specific Proteases/metabolism
    Chemical Substances Analgesics ; Cacna1h protein, mouse ; Calcium Channels, T-Type ; Suramin (6032D45BEM) ; Ubiquitin-Specific Proteases (EC 3.4.19.12) ; Usp5 protein, mouse (EC 3.4.19.12)
    Language English
    Publishing date 2015-03-14
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2174252-2
    ISSN 1744-8069 ; 1744-8069
    ISSN (online) 1744-8069
    ISSN 1744-8069
    DOI 10.1186/s12990-015-0011-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Alterations in STriatal-Enriched protein tyrosine Phosphatase expression, activation, and downstream signaling in early and late stages of the YAC128 Huntington's disease mouse model.

    Gladding, Clare M / Fan, Jing / Zhang, Lily Y J / Wang, Liang / Xu, Jian / Li, Edward H Y / Lombroso, Paul J / Raymond, Lynn A

    Journal of neurochemistry

    2014  Volume 130, Issue 1, Page(s) 145–159

    Abstract: Striatal neurodegeneration and synaptic dysfunction in Huntington's disease are mediated by the mutant huntingtin (mHtt) protein. MHtt disrupts calcium homeostasis and facilitates excitotoxicity, in part by altering NMDA receptor (NMDAR) trafficking and ... ...

    Abstract Striatal neurodegeneration and synaptic dysfunction in Huntington's disease are mediated by the mutant huntingtin (mHtt) protein. MHtt disrupts calcium homeostasis and facilitates excitotoxicity, in part by altering NMDA receptor (NMDAR) trafficking and function. Pre-symptomatic (excitotoxin-sensitive) transgenic mice expressing full-length human mHtt with 128 polyglutamine repeats (YAC128 Huntington's disease mice) show increased calpain activity and extrasynaptic NMDAR (Ex-NMDAR) localization and signaling. Furthermore, Ex-NMDAR stimulation facilitates excitotoxicity in wild-type cortical neurons via calpain-mediated cleavage of STriatal-Enriched protein tyrosine Phosphatase 61 (STEP61). The cleavage product, STEP33, cannot dephosphorylate p38 mitogen-activated protein kinase (MAPK), thereby augmenting apoptotic signaling. Here, we show elevated extrasynaptic calpain-mediated cleavage of STEP61 and p38 phosphorylation, as well as STEP61 inactivation and reduced extracellular signal-regulated protein kinase 1/2 phosphorylation (ERK1/2) in the striatum of 6-week-old, excitotoxin-sensitive YAC128 mice. Calpain inhibition reduced basal and NMDA-induced STEP61 cleavage. However, basal p38 phosphorylation was normalized by a peptide disrupting NMDAR-post-synaptic density protein-95 (PSD-95) binding but not by calpain inhibition. In 1-year-old excitotoxin-resistant YAC128 mice, STEP33 levels were not elevated, but STEP61 inactivation and p38 and ERK 1/2 phosphorylation levels were increased. These results show that in YAC128 striatal tissue, enhanced NMDAR-PSD-95 interactions contributes to elevated p38 signaling in early, excitotoxin-sensitive stages, and suggest that STEP61 inactivation enhances MAPK signaling at late, excitotoxin-resistant stages. The YAC128 Huntington's disease mouse model shows early, enhanced susceptibility to NMDA receptor-mediated striatal apoptosis, progressing to late-stage excitotoxicity resistance. This study shows that elevated NMDA receptor-PSD-95 interactions as well as decreased extrasynaptic STriatal-Enriched protein tyrosine Phosphatase 61 (STEP61) activation may contribute to early enhanced apoptotic signaling. In late-stage YAC128 mice, reduced STEP61 levels and activity correlate with elevated MAPK signaling, consistent with excitotoxicity resistance. Solid and dotted arrows indicate conclusions drawn from the current study and other literature, respectively.
    MeSH term(s) Animals ; Apoptosis/physiology ; Chromosomes, Artificial, Yeast/genetics ; Corpus Striatum/enzymology ; Corpus Striatum/pathology ; Disease Models, Animal ; Enzyme Activation/physiology ; Gene Expression Regulation, Enzymologic ; Humans ; Huntington Disease/enzymology ; Huntington Disease/genetics ; Huntington Disease/pathology ; Male ; Mice ; Mice, Transgenic ; Organ Culture Techniques ; Protein Tyrosine Phosphatases, Non-Receptor/biosynthesis ; Signal Transduction/physiology
    Chemical Substances Protein Tyrosine Phosphatases, Non-Receptor (EC 3.1.3.48) ; Ptpn5 protein, mouse (EC 3.1.3.48)
    Language English
    Publishing date 2014-04-02
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 80158-6
    ISSN 1471-4159 ; 0022-3042 ; 1474-1644
    ISSN (online) 1471-4159
    ISSN 0022-3042 ; 1474-1644
    DOI 10.1111/jnc.12700
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Characterization of the delta2 glutamate receptor-binding protein delphilin: Splicing variants with differential palmitoylation and an additional PDZ domain.

    Matsuda, Keiko / Matsuda, Shinji / Gladding, Clare M / Yuzaki, Michisuke

    The Journal of biological chemistry

    2006  Volume 281, Issue 35, Page(s) 25577–25587

    Abstract: The glutamate receptor delta2 (GluRdelta2) is predominantly expressed at parallel fiber-Purkinje cell postsynapses and plays crucial roles in synaptogenesis and synaptic plasticity. Although the mechanism by which GluRdelta2 functions remains unclear, ... ...

    Abstract The glutamate receptor delta2 (GluRdelta2) is predominantly expressed at parallel fiber-Purkinje cell postsynapses and plays crucial roles in synaptogenesis and synaptic plasticity. Although the mechanism by which GluRdelta2 functions remains unclear, its lack of channel activity and its role in controlling the endocytosis of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors have suggested that GluRdelta2 may convey signals by interacting with intracellular signaling molecules. Among several proteins that interact with GluRdelta2, delphilin is unique in that it is selectively expressed at parallel fiber-Purkinje cell synapses and that, in addition to a single PDZ domain, it contains a formin homology domain that is thought to regulate actin dynamics. Here, we report a new isoform of delphilin, designated as L-delphilin, that has alternatively spliced N-terminal exons encoding an additional PDZ domain. Although original delphilin, designated S-delphilin, was palmitoylated at the N terminus, this region was spliced out in L-delphilin. As a result, S-delphilin was associated with plasma membranes in COS cells and dendritic spines in hippocampal neurons, whereas L-delphilin formed clusters in soma and dendritic shafts. In addition, S-delphilin, but not L-delphilin, facilitated the expression of GluRdelta2 on the cell surface. These results indicate that, like PSD-95 and GRIP/ABP, delphilin isoforms with differential palmitoylation and clustering capabilities may provide two separate intracellular and surface GluRdelta2 pools and may control GluRdelta2 signaling in Purkinje cells.
    MeSH term(s) Alternative Splicing ; Amino Acid Sequence ; Animals ; COS Cells ; Chlorocebus aethiops ; Dendritic Spines/metabolism ; Humans ; Molecular Sequence Data ; Nerve Tissue Proteins/chemistry ; Nerve Tissue Proteins/metabolism ; Palmitic Acid/chemistry ; Protein Binding ; Purkinje Cells/metabolism ; Rats ; Receptors, AMPA/chemistry ; Receptors, Glutamate/chemistry ; Sequence Homology, Amino Acid
    Chemical Substances Nerve Tissue Proteins ; Receptors, AMPA ; Receptors, Glutamate ; delphilin ; glutamate receptor delta 2 ; Palmitic Acid (2V16EO95H1)
    Language English
    Publishing date 2006-07-11
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.M602044200
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  7. Article ; Online: Calpain and STriatal-Enriched protein tyrosine phosphatase (STEP) activation contribute to extrasynaptic NMDA receptor localization in a Huntington's disease mouse model.

    Gladding, Clare M / Sepers, Marja D / Xu, Jian / Zhang, Lily Y J / Milnerwood, Austen J / Lombroso, Paul J / Raymond, Lynn A

    Human molecular genetics

    2012  Volume 21, Issue 17, Page(s) 3739–3752

    Abstract: In Huntington's disease (HD), the mutant huntingtin (mhtt) protein is associated with striatal dysfunction and degeneration. Excitotoxicity and early synaptic defects are attributed, in part, to altered NMDA receptor (NMDAR) trafficking and function. ... ...

    Abstract In Huntington's disease (HD), the mutant huntingtin (mhtt) protein is associated with striatal dysfunction and degeneration. Excitotoxicity and early synaptic defects are attributed, in part, to altered NMDA receptor (NMDAR) trafficking and function. Deleterious extrasynaptic NMDAR localization and signalling are increased early in yeast artificial chromosome mice expressing full-length mhtt with 128 polyglutamine repeats (YAC128 mice). NMDAR trafficking at the plasma membrane is regulated by dephosphorylation of the NMDAR subunit GluN2B tyrosine 1472 (Y1472) residue by STriatal-Enriched protein tyrosine Phosphatase (STEP). NMDAR function is also regulated by calpain cleavage of the GluN2B C-terminus. Activation of both STEP and calpain is calcium-dependent, and disruption of calcium homeostasis occurs early in the HD striatum. Here, we show increased calpain cleavage of GluN2B at both synaptic and extrasynaptic sites, and elevated extrasynaptic total GluN2B expression in the YAC128 striatum. Calpain inhibition significantly reduced extrasynaptic GluN2B expression in the YAC128 but not wild-type striatum. Furthermore, calpain inhibition reduced whole-cell NMDAR current and the surface/internal GluN2B ratio in co-cultured striatal neurons, without affecting synaptic GluN2B localization. Synaptic STEP activity was also significantly higher in the YAC128 striatum, correlating with decreased GluN2B Y1472 phosphorylation. A substrate-trapping STEP protein (TAT-STEP C-S) significantly increased VGLUT1-GluN2B colocalization, as well as increasing synaptic GluN2B expression and Y1472 phosphorylation. Moreover, combined calpain inhibition and STEP inactivation reduced extrasynaptic, while increasing synaptic GluN2B expression in the YAC128 striatum. These results indicate that increased STEP and calpain activation contribute to altered NMDAR localization in an HD mouse model, suggesting new therapeutic targets for HD.
    MeSH term(s) Animals ; Calpain/antagonists & inhibitors ; Calpain/genetics ; Calpain/metabolism ; Coculture Techniques ; Disease Models, Animal ; Enzyme Activation/drug effects ; Enzyme Inhibitors/pharmacology ; Huntington Disease/enzymology ; Huntington Disease/pathology ; Ion Channel Gating/drug effects ; Mice ; Models, Biological ; Neostriatum/drug effects ; Neostriatum/enzymology ; Neostriatum/pathology ; Neurons/drug effects ; Neurons/enzymology ; Phosphorylation/drug effects ; Phosphotyrosine/metabolism ; Protein Transport/drug effects ; Protein Tyrosine Phosphatases, Non-Receptor/metabolism ; Receptors, N-Methyl-D-Aspartate/metabolism ; Synapses/drug effects ; Synapses/enzymology
    Chemical Substances Enzyme Inhibitors ; NR2B NMDA receptor ; Receptors, N-Methyl-D-Aspartate ; Phosphotyrosine (21820-51-9) ; Protein Tyrosine Phosphatases, Non-Receptor (EC 3.1.3.48) ; Ptpn5 protein, mouse (EC 3.1.3.48) ; Calpain (EC 3.4.22.-)
    Language English
    Publishing date 2012-04-20
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1108742-0
    ISSN 1460-2083 ; 0964-6906
    ISSN (online) 1460-2083
    ISSN 0964-6906
    DOI 10.1093/hmg/dds154
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  8. Article ; Online: Tyrosine dephosphorylation regulates AMPAR internalisation in mGluR-LTD.

    Gladding, Clare M / Collett, Valerie J / Jia, Zhengping / Bashir, Zafar I / Collingridge, Graham L / Molnár, Elek

    Molecular and cellular neurosciences

    2008  Volume 40, Issue 2, Page(s) 267–279

    Abstract: Long-term depression (LTD) can be induced at hippocampal CA1 synapses by activation of either NMDA receptors (NMDARs) or group I metabotropic glutamate receptors (mGluRs), using their selective agonists NMDA and (RS)-3,5-dihydroxyphenylglycine (DHPG), ... ...

    Abstract Long-term depression (LTD) can be induced at hippocampal CA1 synapses by activation of either NMDA receptors (NMDARs) or group I metabotropic glutamate receptors (mGluRs), using their selective agonists NMDA and (RS)-3,5-dihydroxyphenylglycine (DHPG), respectively. Recent studies revealed that DHPG-LTD is dependent on activation of postsynaptic protein tyrosine phosphatases (PTPs), which transiently dephosphorylate tyrosine residues in AMPA receptors (AMPARs). Here we show that while both endogenous GluR2 and GluR3 AMPAR subunits are tyrosine phosphorylated at basal activity, only GluR2 is dephosphorylated in DHPG-LTD. The tyrosine dephosphorylation of GluR2 does not occur in NMDA-LTD. Conversely, while NMDA-LTD is associated with the dephosphorylation of GluR1-serine-845, DHPG-LTD does not alter the phosphorylation of this site. The increased AMPAR endocytosis in DHPG-LTD is PTP-dependent and involves tyrosine dephosphorylation of cell surface AMPARs. Together, these results indicate that the subunit selective tyrosine dephosphorylation of surface GluR2 regulates AMPAR internalisation in DHPG-LTD but not in NMDA-LTD in the hippocampus.
    MeSH term(s) Amino Acid Sequence ; Animals ; Endocytosis/physiology ; Excitatory Amino Acid Agonists/metabolism ; Female ; Glycine/analogs & derivatives ; Glycine/metabolism ; Hippocampus/cytology ; Hippocampus/physiology ; Long-Term Synaptic Depression/physiology ; Molecular Sequence Data ; N-Methylaspartate/metabolism ; Phosphorylation ; Protein Subunits/genetics ; Protein Subunits/metabolism ; Rats ; Rats, Wistar ; Receptors, AMPA/metabolism ; Receptors, Metabotropic Glutamate/metabolism ; Resorcinols/metabolism ; Sequence Alignment ; Synapses/metabolism ; Tyrosine/metabolism
    Chemical Substances Excitatory Amino Acid Agonists ; Protein Subunits ; Receptors, AMPA ; Receptors, Metabotropic Glutamate ; Resorcinols ; Tyrosine (42HK56048U) ; 3,5-dihydroxyphenylglycine (5YR2N37E6D) ; N-Methylaspartate (6384-92-5) ; Glycine (TE7660XO1C)
    Language English
    Publishing date 2008-11-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1046640-x
    ISSN 1095-9327 ; 1044-7431
    ISSN (online) 1095-9327
    ISSN 1044-7431
    DOI 10.1016/j.mcn.2008.10.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: P38 MAPK is involved in enhanced NMDA receptor-dependent excitotoxicity in YAC transgenic mouse model of Huntington disease.

    Fan, Jing / Gladding, Clare M / Wang, Liang / Zhang, Lily Y J / Kaufman, Alexandra M / Milnerwood, Austen J / Raymond, Lynn A

    Neurobiology of disease

    2011  Volume 45, Issue 3, Page(s) 999–1009

    Abstract: Huntington disease (HD) is a dominantly inherited neurodegenerative disease caused by a polyglutamine (polyQ) expansion in the protein huntingtin (htt). Previous studies have shown enhanced N-methyl-d-aspartate (NMDA)-induced excitotoxicity in neuronal ... ...

    Abstract Huntington disease (HD) is a dominantly inherited neurodegenerative disease caused by a polyglutamine (polyQ) expansion in the protein huntingtin (htt). Previous studies have shown enhanced N-methyl-d-aspartate (NMDA)-induced excitotoxicity in neuronal models of HD, mediated in part by increased NMDA receptor (NMDAR) GluN2B subunit binding with the postsynaptic density protein-95 (PSD-95). In cultured hippocampal neurons, the NMDAR-activated p38 Mitogen-activated Protein Kinase (MAPK) death pathway is disrupted by a peptide (Tat-NR2B9c) that uncouples GluN2B from PSD-95, whereas NMDAR-mediated activation of c-Jun N-terminal Kinase (JNK) MAPK is PSD-95-independent. To investigate the mechanism by which Tat-NR2B9c protects striatal medium spiny neurons (MSNs) from mutant htt (mhtt)-enhanced NMDAR toxicity, we compared striatal tissue and cultured MSNs from presymptomatic yeast artificial chromosome (YAC) mice expressing htt with 128 polyQ (YAC128) to those from YAC18 and/or WT mice as controls. Similar to the previously published shift of GluN2B-containing NMDARs to extrasynaptic sites, we found increased PSD-95 localization as well as elevated PSD-95-GluN2B interactions in the striatal non-PSD (extrasynaptic) fraction from YAC128 mice. Notably, basal levels of both activated p38 and JNK MAPKs were elevated in the YAC128 striatum. NMDA stimulation of acute slices increased activation of p38 and JNK in WT and YAC128 striatum, but Tat-NR2B9c pretreatment reduced only the p38 activation in YAC128. In cultured MSNs, p38 MAPK inhibition reduced YAC128 NMDAR-mediated cell death to WT levels, and occluded the Tat-NR2B9c peptide protective effect; in contrast, inhibition of JNK had a similar protective effect in cultured MSNs from both WT and YAC128 mice. Our results suggest that altered activation of p38 MAPK contributes to mhtt enhancement of GluN2B/PSD-95 toxic signaling.
    MeSH term(s) Analysis of Variance ; Animals ; Animals, Newborn ; Apoptosis/drug effects ; Apoptosis/genetics ; Bacterial Proteins/genetics ; Cerebral Cortex/cytology ; Chromosomes, Artificial, Yeast/genetics ; Coculture Techniques ; Corpus Striatum/pathology ; Disease Models, Animal ; Disks Large Homolog 4 Protein ; Embryo, Mammalian ; Enzyme Inhibitors/pharmacology ; Gene Expression Regulation/drug effects ; Gene Expression Regulation/genetics ; Guanylate Kinases/metabolism ; Humans ; Huntingtin Protein ; Huntington Disease/genetics ; Huntington Disease/pathology ; Immunoprecipitation/methods ; In Situ Nick-End Labeling ; Luminescent Proteins/genetics ; Membrane Proteins/metabolism ; Mice ; Mice, Transgenic ; N-Methylaspartate/pharmacology ; Nerve Tissue Proteins/genetics ; Neurons/drug effects ; Neurons/metabolism ; Nuclear Proteins/genetics ; Peptides/genetics ; Peptides/pharmacology ; Receptors, N-Methyl-D-Aspartate/chemistry ; Receptors, N-Methyl-D-Aspartate/metabolism ; Subcellular Fractions/drug effects ; Subcellular Fractions/metabolism ; p38 Mitogen-Activated Protein Kinases/metabolism
    Chemical Substances Bacterial Proteins ; Disks Large Homolog 4 Protein ; Dlg4 protein, mouse ; Enzyme Inhibitors ; HTT protein, human ; Huntingtin Protein ; Luminescent Proteins ; Membrane Proteins ; NR2A NMDA receptor ; Nerve Tissue Proteins ; Nuclear Proteins ; Peptides ; Receptors, N-Methyl-D-Aspartate ; yellow fluorescent protein, Bacteria ; polyglutamine (26700-71-0) ; N-Methylaspartate (6384-92-5) ; Tat-NR2B9c (D45TI2TWMA) ; p38 Mitogen-Activated Protein Kinases (EC 2.7.11.24) ; Guanylate Kinases (EC 2.7.4.8)
    Language English
    Publishing date 2011-12-14
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1211786-9
    ISSN 1095-953X ; 0969-9961
    ISSN (online) 1095-953X
    ISSN 0969-9961
    DOI 10.1016/j.nbd.2011.12.019
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Mitigation of augmented extrasynaptic NMDAR signaling and apoptosis in cortico-striatal co-cultures from Huntington's disease mice.

    Milnerwood, Austen J / Kaufman, Alexandra M / Sepers, Marja D / Gladding, Clare M / Zhang, Lily / Wang, Liang / Fan, Jing / Coquinco, Ainsley / Qiao, Joy Yi / Lee, Hwan / Wang, Yu Tian / Cynader, Max / Raymond, Lynn A

    Neurobiology of disease

    2012  Volume 48, Issue 1, Page(s) 40–51

    Abstract: We recently reported evidence for disturbed synaptic versus extrasynaptic NMDAR transmission in the early pathogenesis of Huntington's disease (HD), a late-onset neurodegenerative disorder caused by CAG repeat expansion in the gene encoding huntingtin. ... ...

    Abstract We recently reported evidence for disturbed synaptic versus extrasynaptic NMDAR transmission in the early pathogenesis of Huntington's disease (HD), a late-onset neurodegenerative disorder caused by CAG repeat expansion in the gene encoding huntingtin. Studies in glutamatergic cells indicate that synaptic NMDAR transmission increases phosphorylated cyclic-AMP response element binding protein (pCREB) levels and drives neuroprotective gene transcription, whereas extrasynaptic NMDAR activation reduces pCREB and promotes cell death. By generating striatal and cortical neuronal co-cultures to investigate the glutamatergic innervation of striatal neurons, we demonstrate that dichotomous synaptic and extrasynaptic NMDAR signaling also occurs in GABAergic striatal medium-sized spiny neurons (MSNs), which are acutely vulnerable in HD. Further, we show that wild-type (WT) and HD transgenic YAC128 MSNs co-cultured with cortical cells have similar levels of glutamatergic synapses, synaptic NMDAR currents and synaptic GluN2B and GluN2A subunit-containing NMDARs. However, NMDAR whole-cell, and especially extrasynaptic, current is elevated in YAC128 MSNs. Moreover, GluN2B subunit-containing NMDAR surface expression is markedly increased, irrespective of whether or not the co-cultured cortical cells express mutant huntingtin. The data suggest that MSN cell-autonomous increases in extrasynaptic NMDARs are driven by the HD mutation. Consistent with these results, we find that extrasynaptic NMDAR-induced pCREB reductions and apoptosis are also augmented in YAC128 MSNs. Moreover, both NMDAR-mediated apoptosis and CREB-off signaling are blocked by co-application of either memantine or the GluN2B subunit-selective antagonist ifenprodil in YAC128 MSNs. GluN2A-subunit-selective concentrations of the antagonist NVP-AAM077 did not reduce cell death in either genotype. Cortico-striatal co-cultures provide an in vitro model system in which to better investigate striatal neuronal dysfunction in disease than mono-cultured striatal cells. Results from the use of this system, which partially recapitulates the cortico-striatal circuit and is amenable to acute genetic and pharmacological manipulations, suggest that pathophysiological NMDAR signaling is an intrinsic frailty in HD MSNs that can be successfully targeted by pharmacological interventions.
    MeSH term(s) Animals ; Apoptosis/drug effects ; Apoptosis/physiology ; Cerebral Cortex/drug effects ; Cerebral Cortex/metabolism ; Cerebral Cortex/pathology ; Coculture Techniques ; Corpus Striatum/drug effects ; Corpus Striatum/metabolism ; Corpus Striatum/pathology ; Disease Models, Animal ; Excitatory Amino Acid Antagonists/pharmacology ; Huntington Disease/genetics ; Huntington Disease/metabolism ; Huntington Disease/pathology ; Memantine/pharmacology ; Mice ; Mice, Transgenic ; Neurons/drug effects ; Neurons/metabolism ; Neurons/pathology ; Piperidines/pharmacology ; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors ; Receptors, N-Methyl-D-Aspartate/metabolism ; Signal Transduction/drug effects ; Signal Transduction/physiology
    Chemical Substances Excitatory Amino Acid Antagonists ; Piperidines ; Receptors, N-Methyl-D-Aspartate ; ifenprodil (R8OE3P6O5S) ; Memantine (W8O17SJF3T)
    Language English
    Publishing date 2012-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1211786-9
    ISSN 1095-953X ; 0969-9961
    ISSN (online) 1095-953X
    ISSN 0969-9961
    DOI 10.1016/j.nbd.2012.05.013
    Database MEDical Literature Analysis and Retrieval System OnLINE

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