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Inoue K, O'Bryant Z, Xiong ZG. Zinc-permeable ion channels: effects on intracellular zinc dynamics and potential physiological/pathophysiological significance. Curr Med Chem 2015; 22:1248-57. [PMID: 25666796 PMCID: PMC4363167 DOI: 10.2174/0929867322666150209153750] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/14/2014] [Accepted: 02/02/2015] [Indexed: 02/08/2023]
Abstract
Zinc (Zn(2+)) is one of the most important trace metals in the body. It is necessary for the normal function of a large number of protein s including enzymes and transcription factors. While extracellular fluid may contain up to micromolar Zn(2+), intracellular Zn(2+) concentration is generally maintained at a subnanomolar level; this steep gradient across the cell membrane is primarily attributable to Zn(2+) extrusion by Zn(2+) transporting systems. Interestingly, systematic investigation has revealed that activities, previously believed to be dependent on calcium (Ca(2+)), may be partially mediated by Zn(2+). This is also supported by new findings that some Ca(2+)-permeable channels such as voltage-dependent calcium channels (VDCCs), N-methyl-D-aspartate receptors (NMDA), and amino-3- hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPA-Rs) are also permeable to Zn(2+). Thus, the importance of Zn(2+) in physiological and pathophysiological processes is now more widely appreciated. In this review, we describe Zn(2+)- permeable membrane molecules, especially Zn(2+)-permeable ion channels, in intracellular Zn(2+)dynamics and Zn(2+) mediated physiology/pathophysiology.
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Affiliation(s)
- Koichi Inoue
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, USA.
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Matias CM, Dionísio JC, Saggau P, Quinta-Ferreira ME. Activation of group II metabotropic glutamate receptors blocks zinc release from hippocampal mossy fibers. Biol Res 2014; 47:73. [PMID: 25723955 PMCID: PMC4289587 DOI: 10.1186/0717-6287-47-73] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 11/25/2014] [Indexed: 11/17/2022] Open
Abstract
Background The hippocampal CA3 area contains large amounts of vesicular zinc in the mossy fiber terminals which is released during synaptic activity, depending on presynaptic calcium. Another characteristic of these synapses is the presynaptic localization of high concentrations of group II metabotropic glutamate receptors, specifically activated by DCG-IV. Previous work has shown that DCG-IV affects only mossy fiber-evoked responses but not the signals from associational-commissural afferents, blocking mossy fiber synaptic transmission. Since zinc is released from mossy fibers even for single stimuli and it is generally assumed to be co-released with glutamate, the aim of the work was to investigate the effect of DCG-IV on mossy fiber zinc signals. Results Studies were performed using the membrane-permeant fluorescent zinc probe TSQ, and indicate that DCG-IV almost completely abolishes mossy fiber zinc changes as it does with synaptic transmission. Conclusions Zinc signaling is regulated by the activation of type II metabotropic receptors, as it has been previously shown for glutamate, further supporting the corelease of glutamate and zinc from mossy fibers.
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Affiliation(s)
- Carlos M Matias
- Center for Neurosciences of Coimbra, University of Coimbra, 3004-516, Coimbra, Portugal. .,Department of Physics, School of Science and Technology, University of Trás-os-montes and Alto Douro (UTAD), Quinta dos Prados, 5000-911, Vila Real, Portugal.
| | - Jose C Dionísio
- Department Animal Biology, FCUL, University Lisbon, Campo Grande, Lisbon, Portugal.
| | - Peter Saggau
- Allen Institute for Brain Science, 551, N 34th Street, Seattle, USA.
| | - Maria Emilia Quinta-Ferreira
- Center for Neurosciences of Coimbra, University of Coimbra, 3004-516, Coimbra, Portugal. .,Department of Physics, University of Coimbra, 3004-516 Coimbra, Portugal, University of Coimbra, 3004-516, Coimbra, Portugal.
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Jurowski K, Szewczyk B, Nowak G, Piekoszewski W. Biological consequences of zinc deficiency in the pathomechanisms of selected diseases. J Biol Inorg Chem 2014; 19:1069-79. [PMID: 24748223 PMCID: PMC4175048 DOI: 10.1007/s00775-014-1139-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 04/09/2014] [Indexed: 01/01/2023]
Abstract
From many points of view, zinc is one of the most important trace elements in biological systems. Many articles describe the well-known role of this metal in human physiology and pathophysiology, but in the related literature, there is a lack of current and reliable reviews of the role of zinc deficiency in many diseases. In this article, we describe the role of zinc deficiency in the oxidative stress control, immune response, proliferation, and pathogenesis and pathophysiology of selected diseases such as depression, cardiovascular diseases, diabetes mellitus, Alzheimer's disease, and Wilson's disease.
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Affiliation(s)
- Kamil Jurowski
- Department of Analytical Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Kraków, Poland
- Malopolska Centre for Translational Medicine, Faculty of Medicine, Jagiellonian University Collegium Medicum, Kraków, Poland
| | | | - Gabriel Nowak
- Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
- Faculty of Pharmacy, Jagiellonian University Collegium Medicum, Kraków, Poland
| | - Wojciech Piekoszewski
- Department of Analytical Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Kraków, Poland
- Laboratory of High Resolution Mass Spectrometry, Regional Laboratory of Physicochemical Analysis and Structural Research, Faculty of Chemistry, Jagiellonian University, Kraków, Poland
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Marchetti C. Interaction of metal ions with neurotransmitter receptors and potential role in neurodiseases. Biometals 2014; 27:1097-113. [PMID: 25224737 DOI: 10.1007/s10534-014-9791-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/05/2014] [Indexed: 12/25/2022]
Abstract
There is increasing evidence that toxic metals play a role in diseases of unknown etiology. Their action is often mediated by membrane proteins, and in particular neurotransmitter receptors. This brief review will describe recent findings on the direct interaction of metal ions with ionotropic γ-aminobutyric acid (GABAA) and glutamate receptors, the main inhibitory and excitatory neurotransmitter receptors in the mammalian central nervous system, respectively. Both hyper and hypo function of these receptors are involved in neurological and psychotic syndromes and modulation by metal ions is an important pharmacological issue. The focus will be on three xenobiotic metals, lead (Pb), cadmium (Cd) and nickel (Ni) that have no biological function and whose presence in living organisms is only detrimental, and two trace metals, zinc (Zn) and copper (Cu), which are essential for several enzymatic functions, but can mediate toxic actions if deregulated. Despite limited access to the brain and tight control by metalloproteins, exogenous metals interfere with receptor performances by mimicking physiological ions and occupying one or more modulatory sites on the protein. These interactions will be discussed as a potential cause of neuronal dysfunction.
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Affiliation(s)
- Carla Marchetti
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via De Marini, 6, 16149, Genoa, Italy,
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55
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Ballestín R, Blasco-Ibáñez JM, Crespo C, Nacher J, López-Hidalgo R, Gilabert-Juan J, Moltó D, Varea E. Astrocytes of the murine model for Down Syndrome Ts65Dn display reduced intracellular ionic zinc. Neurochem Int 2014; 75:48-53. [PMID: 24911951 DOI: 10.1016/j.neuint.2014.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 05/23/2014] [Accepted: 05/29/2014] [Indexed: 11/30/2022]
Abstract
Zinc is an essential trace element that is critical for a large number of structural proteins, enzymatic processes and transcription factors. In the brain, zinc ions are involved in synaptic transmission. The homeostasis of zinc is crucial for cell survival and function, and cells have developed a wide variety of systems to control zinc concentration. Alterations in free zinc concentration have been related with brain dysfunction. Down Syndrome individuals present alterations in free zinc concentration and in some of the proteins related with zinc homeostasis. We have analyzed the amount of free zinc and the zinc chelating protein metallothionein 3 in the astrocytes using primary cultures of the murine model Ts65Dn. We have observed a higher number of zinc positive spots in the cytoplasm of trisomic astrocytes but a decrease in the total concentration of total intracellular free zinc concentration (including the spots) respect to control astrocytes. Using FM1-43 staining, we found that the endocytic function remains unaltered. Therefore, a possible explanation for this lower concentration of free zinc could be the higher concentration of metallothionein 3 present in the cytoplasm of trisomic astrocytes. The blockade of metallothionein 3 expression using an specific siRNA induced an increase in the concentration of free zinc in basal conditions but failed to increase the uptake of zinc after incubation with zinc ions.
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Affiliation(s)
- Raúl Ballestín
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - José Miguel Blasco-Ibáñez
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Carlos Crespo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Juan Nacher
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Rosa López-Hidalgo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Javier Gilabert-Juan
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain; Genetics Department, Universitat de València, INCLIVA, CIBERSAM, Spain
| | - Dolores Moltó
- Genetics Department, Universitat de València, INCLIVA, CIBERSAM, Spain
| | - Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain.
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Malhotra A, Dhawan DK. Current view of zinc as a hepatoprotective agent in conditions of chlorpyrifos induced toxicity. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2014; 112:1-6. [PMID: 24974110 DOI: 10.1016/j.pestbp.2014.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 04/15/2014] [Accepted: 04/21/2014] [Indexed: 11/18/2022]
Affiliation(s)
- Anshoo Malhotra
- Department of Biophysics, Post Graduate Institute of Medical Education & Research, Chandigarh, India
| | - D K Dhawan
- Department of Biophysics, Panjab University, Chandigarh, India.
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McCord MC, Aizenman E. The role of intracellular zinc release in aging, oxidative stress, and Alzheimer's disease. Front Aging Neurosci 2014; 6:77. [PMID: 24860495 PMCID: PMC4028997 DOI: 10.3389/fnagi.2014.00077] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 04/02/2014] [Indexed: 01/26/2023] Open
Abstract
Brain aging is marked by structural, chemical, and genetic changes leading to cognitive decline and impaired neural functioning. Further, aging itself is also a risk factor for a number of neurodegenerative disorders, most notably Alzheimer’s disease (AD). Many of the pathological changes associated with aging and aging-related disorders have been attributed in part to increased and unregulated production of reactive oxygen species (ROS) in the brain. ROS are produced as a physiological byproduct of various cellular processes, and are normally detoxified by enzymes and antioxidants to help maintain neuronal homeostasis. However, cellular injury can cause excessive ROS production, triggering a state of oxidative stress that can lead to neuronal cell death. ROS and intracellular zinc are intimately related, as ROS production can lead to oxidation of proteins that normally bind the metal, thereby causing the liberation of zinc in cytoplasmic compartments. Similarly, not only can zinc impair mitochondrial function, leading to excess ROS production, but it can also activate a variety of extra-mitochondrial ROS-generating signaling cascades. As such, numerous accounts of oxidative neuronal injury by ROS-producing sources appear to also require zinc. We suggest that zinc deregulation is a common, perhaps ubiquitous component of injurious oxidative processes in neurons. This review summarizes current findings on zinc dyshomeostasis-driven signaling cascades in oxidative stress and age-related neurodegeneration, with a focus on AD, in order to highlight the critical role of the intracellular liberation of the metal during oxidative neuronal injury.
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Affiliation(s)
- Meghan C McCord
- Department of Neurobiology, University of Pittsburgh School of Medicine Pittsburgh, PA, USA
| | - Elias Aizenman
- Department of Neurobiology, University of Pittsburgh School of Medicine Pittsburgh, PA, USA
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Ceccom J, Halley H, Daumas S, Lassalle JM. A specific role for hippocampal mossy fiber's zinc in rapid storage of emotional memories. Learn Mem 2014; 21:287-97. [PMID: 24741109 PMCID: PMC3994499 DOI: 10.1101/lm.033472.113] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We investigated the specific role of zinc present in large amounts in the synaptic vesicles of mossy fibers and coreleased with glutamate in the CA3 region. In previous studies, we have shown that blockade of zinc after release has no effect on the consolidation of spatial learning, while zinc is required for the consolidation of contextual fear conditioning. Although both are hippocampo-dependent processes, fear conditioning to the context implies a strong emotional burden. To verify the hypothesis that zinc could play a specific role in enabling sustainable memorization of a single event with a strong emotional component, we used a neuropharmacological approach combining a glutamate receptor antagonist with different zinc chelators. Results show that zinc is mandatory to allow the consolidation of one-shot memory, thus being the key element allowing the hippocampus submitted to a strong emotional charge to switch from the cognitive mode to a flashbulb memory mode. Individual differences in learning abilities have been known for a long time to be totally or partially compensated by distributed learning practice. Here we show that contextual fear conditioning impairments due to zinc blockade can be efficiently reduced by distributed learning practice.
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Affiliation(s)
- Johnatan Ceccom
- Université de Toulouse, UPS, Centre de Recherches sur la Cognition Animale, F-31062 Toulouse Cedex 9, France
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Adlard PA, Sedjahtera A, Gunawan L, Bray L, Hare D, Lear J, Doble P, Bush AI, Finkelstein DI, Cherny RA. A novel approach to rapidly prevent age-related cognitive decline. Aging Cell 2014; 13:351-9. [PMID: 24305557 PMCID: PMC4331782 DOI: 10.1111/acel.12178] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2013] [Indexed: 12/22/2022] Open
Abstract
The loss of cognitive function is a pervasive and often debilitating feature of the aging process for which there are no effective therapeutics. We hypothesized that a novel metal chaperone (PBT2; Prana Biotechnology, Parkville, Victoria, Australia) would enhance cognition in aged rodents. We show here that PBT2 rapidly improves the performance of aged C57Bl/6 mice in the Morris water maze, concomitant with increases in dendritic spine density, hippocampal neuron number and markers of neurogenesis. There were also increased levels of specific glutamate receptors (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and N-methyl-d-aspartate), the glutamate transporter (VGLUT1) and glutamate itself. Markers of synaptic plasticity [calmodulin-dependent protein kinase II (CaMKII) and phosphorylated CaMKII, CREB, synaptophysin] were also increased following PBT2 treatment. We also demonstrate that PBT2 treatment results in a subregion-specific increase in hippocampal zinc, which is increasingly recognized as a potent neuromodulator. These data demonstrate that metal chaperones are a novel approach to the treatment of age-related cognitive decline.
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Affiliation(s)
- Paul A. Adlard
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
| | - Amelia Sedjahtera
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
| | - Lydia Gunawan
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
| | - Lisa Bray
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
| | - Dominic Hare
- Elemental Bio‐imaging Facility University of Technology Sydney NSW 2007 Australia
| | - Jessica Lear
- Elemental Bio‐imaging Facility University of Technology Sydney NSW 2007 Australia
| | - Philip Doble
- Elemental Bio‐imaging Facility University of Technology Sydney NSW 2007 Australia
| | - Ashley I. Bush
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
| | - David I. Finkelstein
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
| | - Robert A. Cherny
- The Florey Institute of Neuroscience and Mental Health Kenneth Myer Building At Genetics Lane on Royal Parade The University of Melbourne Melbourne Vic. 3010 Australia
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Stepanyuk AR, Borisyuk AL, Tsugorka TM, Belan PV. Different pools of postsynaptic GABAA receptors mediate inhibition evoked by low- and high-frequency presynaptic stimulation at hippocampal synapses. Synapse 2014; 68:344-54. [PMID: 24677449 DOI: 10.1002/syn.21742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 03/16/2014] [Accepted: 03/21/2014] [Indexed: 11/12/2022]
Abstract
Patterns of short-term synaptic plasticity could considerably differ between synapses of the same axon. This may lead to separation of synaptic receptors transmitting either low- or high-frequency signals and, therefore, may have functional consequences for the information transfer in the brain. Here, we estimated a degree of such separation at hippocampal GABAergic synapses using a use-dependent GABAA receptor antagonist, picrotoxin, to selectively suppress a pool of GABAA receptors monosynaptically activated during the low-frequency stimulation. The relative changes in postsynaptic responses evoked by the high-frequency stimulation before and after such block were used to estimate the contribution of this GABAA receptor pool to synaptic transmission at high frequencies. Using this approach, we have shown that IPSCs evoked by low-frequency (0.2 Hz) stimulation and asynchronous currents evoked by high-frequency (20-40 Hz) stimulation are mediated by different pools of postsynaptic GABAA receptors. Thus, our findings suggest that inhibition produced by a single hippocampal interneuron may be selectively routed to different postsynaptic targets depending on the presynaptic discharge frequency.
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Affiliation(s)
- Andrey R Stepanyuk
- Department of General Physiology of the Nervous System, Bogomoletz Institute of Physiology, 4 Bogomoletz street, Kiev, 01024, Ukraine; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology, 4 Bogomoletz street, Kiev, 01024, Ukraine
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Ippolito JE, Piwnica-Worms D. A fluorescence-coupled assay for gamma aminobutyric acid (GABA) reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer. PLoS One 2014; 9:e88667. [PMID: 24551133 PMCID: PMC3923810 DOI: 10.1371/journal.pone.0088667] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/15/2014] [Indexed: 11/18/2022] Open
Abstract
Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA) have been implicated in the pathogenesis of high grade neuroendocrine (NE) neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1), was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC) cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL) activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.
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Affiliation(s)
- Joseph E. Ippolito
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail: (JEI); (DP-W)
| | - David Piwnica-Worms
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Cancer Systems Imaging, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- * E-mail: (JEI); (DP-W)
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Liu J, Wang YT. Allosteric modulation of GABAA receptors by extracellular ATP. Mol Brain 2014; 7:6. [PMID: 24456563 PMCID: PMC3904413 DOI: 10.1186/1756-6606-7-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 12/19/2013] [Indexed: 11/16/2022] Open
Abstract
Background The γ-aminobutyric acid type A receptor (GABAAR) is the primary receptor mediating fast synaptic inhibition in the brain and plays a critical role in modulation of neuronal excitability and neural networks. Previous studies have demonstrated that ATP and its nucleotide analogs may regulate the function of GABAARs via Ca2+-dependent intracellular mechanisms, which require activation of purinergic 2 (P2) receptors or cross-talk between two receptors. Results Here, we report a potentiation of GABAARs by extracellular ATP via a previously un-recognized allosteric mechanism. Using cultured hippocampal neurons as well as HEK293 cells transiently expressing GABAARs, we demonstrate that extracellular ATP potentiates GABAAR mediated currents in a dose-dependent manner with an EC50 of 2.1 ± 0.2 mM. The potentiation was mediated by a postsynaptic mechanism that was not dependent on activation of either ecto-protein kinase or P2 receptors. Single channel recordings from cell-free excised membrane patches under outside-out mode or isolated membrane patches under cell-attached mode suggest that the ATP modulation of GABA currents is achieved through a direct action of ATP on the channels themselves and manifested by increasing the single channel open probability without alteration of its conductance. Moreover, this ATP potentiation of GABAAR could be reconstituted in HEK293 cells that transiently expressed recombinant rat GABAARs. Conclusions Our data strongly suggest that extracellular ATP allosterically potentiates GABAAR-gated chloride channels. This novel mode of ATP-mediated modulation of GABAARs may play an important role in regulating neuronal excitability and thereby in fine-tuning the excitation-inhibition balance under conditions where a high level of extracellular ATP is ensured.
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Affiliation(s)
| | - Yu Tian Wang
- Brain Research Centre and Department of Medicine, Vancouver Coastal Health Research Institute, University of British Columbia, Vancouver, BC V6T 2B5, Canada.
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Mot AI, Wedd AG, Sinclair L, Brown DR, Collins SJ, Brazier MW. Metal attenuating therapies in neurodegenerative disease. Expert Rev Neurother 2014; 11:1717-45. [DOI: 10.1586/ern.11.170] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Grønli O, Kvamme JM, Friborg O, Wynn R. Zinc deficiency is common in several psychiatric disorders. PLoS One 2013; 8:e82793. [PMID: 24367556 PMCID: PMC3868572 DOI: 10.1371/journal.pone.0082793] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/28/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Mounting evidence suggests a link between low zinc levels and depression. There is, however, little knowledge about zinc levels in older persons with other psychiatric diagnoses. Therefore, we explore the zinc status of elderly patients suffering from a wide range of psychiatric disorders. METHODS Clinical data and blood samples for zinc analyzes were collected from 100 psychogeriatric patients over 64 of age. Psychiatric and cognitive symptoms were assessed using the Montgomery and Aasberg Depression Rating Scale, the Cornell Scale for Depression in Dementia, the Mini-Mental State Examination, the Clockdrawing Test, clinical interviews and a review of medical records. In addition, a diagnostic interview was conducted using the Mini International Neuropsychiatric Interview instrument. The prevalence of zinc deficiency in patients with depression was compared with the prevalence in patients without depression, and the prevalence in a control group of 882 older persons sampled from a population study. RESULTS There was a significant difference in zinc deficiency prevalence between the control group (14.4%) and the patient group (41.0%) (χ(2) = 44.81, df = 1, p<0.001). In a logistic model with relevant predictors, zinc deficiency was positively associated with gender and with serum albumin level. The prevalence of zinc deficiency in the patient group was significantly higher in patients without depression (i.e. with other diagnoses) than in patients with depression as a main diagnosis or comorbid depression (χ(2) = 4.36, df = 1, p = 0.037). CONCLUSIONS Zinc deficiency is quite common among psychogeriatric patients and appears to be even more prominent in patients suffering from other psychiatric disorders than depression. LIMITATIONS This study does not provide a clear answer as to whether the observed differences represent a causal relationship between zinc deficiency and psychiatric symptoms. The blood sample collection time points varied in both the control group and the patient group. No data regarding zinc supplementation were collected.
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Affiliation(s)
- Ole Grønli
- Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
- Division of Addictions and Specialized Psychiatric Services, University Hospital of North Norway, Tromsø, Norway
- * E-mail:
| | - Jan Magnus Kvamme
- Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
| | - Oddgeir Friborg
- Division of Addictions and Specialized Psychiatric Services, University Hospital of North Norway, Tromsø, Norway
- Department of Psychology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
| | - Rolf Wynn
- Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
- Division of Addictions and Specialized Psychiatric Services, University Hospital of North Norway, Tromsø, Norway
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Grauert A, Engel D, Ruiz AJ. Endogenous zinc depresses GABAergic transmission via T-type Ca(2+) channels and broadens the time window for integration of glutamatergic inputs in dentate granule cells. J Physiol 2013; 592:67-86. [PMID: 24081159 PMCID: PMC3903352 DOI: 10.1113/jphysiol.2013.261420] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Abstract Zinc actions on synaptic transmission span the modulation of neurotransmitter receptors, transporters, activation of intracellular cascades and alterations in gene expression. Whether and how zinc affects inhibitory synaptic signalling in the dentate gyrus remains largely unexplored. We found that mono- and di-synaptic GABAergic inputs onto dentate granule cells were reversibly depressed by exogenous zinc application and enhanced by zinc chelation. Blocking T-type Ca2+ channels prevented the effect of zinc chelation. When recording from dentate fast-spiking interneurones, zinc chelation facilitated T-type Ca2+ currents, increased action potential half-width and decreased spike threshold. It also increased the offset of the input–output relation in a manner consistent with enhanced excitability. In granule cells, chelation of zinc reduced the time window for the integration of glutamatergic inputs originating from perforant path synapses, resulting in reduced spike transfer. Thus, zinc-mediated modulation of dentate interneurone excitability and GABA release regulates information flow to local targets and hippocampal networks.
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Affiliation(s)
- Antonia Grauert
- A. J. Ruiz: Department of Pharmacology, School of Pharmacy, University College London, Brunswick Square, London WC1A 1AX, UK.
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Oxidative stress and the pathogenesis of Alzheimer's disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:316523. [PMID: 23983897 PMCID: PMC3745981 DOI: 10.1155/2013/316523] [Citation(s) in RCA: 498] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 07/03/2013] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease that causes dementia in the elderly. Patients with AD suffer a gradual deterioration of memory and other cognitive functions, which eventually leads to a complete incapacity and death. A complicated array of molecular events has been implicated in the pathogenesis of AD. The major pathological characteristics of AD brains are the presence of senile plaques, neurofibrillary tangles, and neuronal loss. Growing evidence has demonstrated that oxidative stress is an important factor contributing to the initiation and progression of AD. However, the mechanisms that lead to the disruption of redox balance and the sources of free radicals remain elusive. The excessive reactive oxygen species may be generated from mechanisms such as mitochondria dysfunction and/or aberrant accumulation of transition metals, while the abnormal accumulation of Abeta and tau proteins appears to promote the redox imbalance. The resulted oxidative stress has been implicated in Abeta- or tau-induced neurotoxicity. In addition, evidence has suggested that oxidative stress may augment the production and aggregation of Abeta and facilitate the phosphorylation and polymerization of tau, thus forming a vicious cycle that promotes the initiation and progression of AD.
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Szewczyk B. Zinc homeostasis and neurodegenerative disorders. Front Aging Neurosci 2013; 5:33. [PMID: 23882214 PMCID: PMC3715721 DOI: 10.3389/fnagi.2013.00033] [Citation(s) in RCA: 192] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 06/24/2013] [Indexed: 12/19/2022] Open
Abstract
Zinc is an essential trace element, whose importance to the function of the central nervous system (CNS) is increasingly being appreciated. Alterations in zinc dyshomeostasis has been suggested as a key factor in the development of several neuropsychiatric disorders. In the CNS, zinc occurs in two forms: the first being tightly bound to proteins and, secondly, the free, cytoplasmic, or extracellular form found in presynaptic vesicles. Under normal conditions, zinc released from the synaptic vesicles modulates both ionotropic and metabotropic post-synaptic receptors. While under clinical conditions such as traumatic brain injury, stroke or epilepsy, the excess influx of zinc into neurons has been found to result in neurotoxicity and damage to postsynaptic neurons. On the other hand, a growing body of evidence suggests that a deficiency, rather than an excess, of zinc leads to an increased risk for the development of neurological disorders. Indeed, zinc deficiency has been shown to affect neurogenesis and increase neuronal apoptosis, which can lead to learning and memory deficits. Altered zinc homeostasis is also suggested as a risk factor for depression, Alzheimer's disease (AD), aging, and other neurodegenerative disorders. Under normal CNS physiology, homeostatic controls are put in place to avoid the accumulation of excess zinc or its deficiency. This cellular zinc homeostasis results from the actions of a coordinated regulation effected by different proteins involved in the uptake, excretion and intracellular storage/trafficking of zinc. These proteins include membranous transporters (ZnT and Zip) and metallothioneins (MT) which control intracellular zinc levels. Interestingly, alterations in ZnT and MT have been recently reported in both aging and AD. This paper provides an overview of both clinical and experimental evidence that implicates a dysfunction in zinc homeostasis in the pathophysiology of depression, AD, and aging.
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Affiliation(s)
- Bernadeta Szewczyk
- Department of Neurobiology, Institute of Pharmacology Polish Academy of SciencesKrakow, Poland
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Using C. elegans to Decipher the Cellular and Molecular Mechanisms Underlying Neurodevelopmental Disorders. Mol Neurobiol 2013; 48:465-89. [DOI: 10.1007/s12035-013-8434-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 02/26/2013] [Indexed: 10/27/2022]
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Gu Y, Barry J, Gu C. Kv3 channel assembly, trafficking and activity are regulated by zinc through different binding sites. J Physiol 2013; 591:2491-507. [PMID: 23420657 DOI: 10.1113/jphysiol.2013.251983] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Zinc, a divalent heavy metal ion and an essential mineral for life, regulates synaptic transmission and neuronal excitability via ion channels. However, its binding sites and regulatory mechanisms are poorly understood. Here, we report that Kv3 channel assembly, localization and activity are regulated by zinc through different binding sites. Local perfusion of zinc reversibly reduced spiking frequency of cultured neurons most likely by suppressing Kv3 channels. Indeed, zinc inhibited Kv3.1 channel activity and slowed activation kinetics, independent of its site in the N-terminal T1 domain. Biochemical assays surprisingly identified a novel zinc-binding site in the Kv3.1 C-terminus, critical for channel activity and axonal targeting, but not for the zinc inhibition. Finally, mutagenesis revealed an important role of the junction between the first transmembrane (TM) segment and the first extracellular loop in sensing zinc. Its mutant enabled fast spiking with relative resistance to the zinc inhibition. Therefore, our studies provide novel mechanistic insights into the multifaceted regulation of Kv3 channel activity and localization by divalent heavy metal ions.
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Affiliation(s)
- Yuanzheng Gu
- 182 Rightmire Hall, 1060 Carmack Road, The Ohio State University, Columbus, OH 43210, USA.
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71
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Tamba BI, Leon MM, Petreus T. Common trace elements alleviate pain in an experimental mouse model. J Neurosci Res 2013; 91:554-61. [PMID: 23362003 DOI: 10.1002/jnr.23191] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 11/25/2012] [Indexed: 11/10/2022]
Abstract
Trace elements represent a group of essential metals or metaloids necessary for life, present in minute amounts. Analgesic adjuvants can enhance the effect of other pain drugs or be used for pain control themselves. Previous studies on the effects of trace elements on nociception and their potential use as analgesic adjuvants have yielded conflicting results. In this study, we tested the hypothesis that three vital trace elements (Zn²⁺, Mg²⁺, Cu²⁺) have direct antinociceptive effects. Groups of eight Swiss mice were intraperitoneally (i.p) injected with incremental concentrations of Zn²⁺ sulfate (0.5, 2.0 mg/kg), Zn²⁺ citrate (0.125, 0.5 mg/kg), Mg²⁺ chloride (37.5, 75, 150 mg/kg), Cu²⁺ chloride (0.5, 1.0, 2.0 mg/kg), and Cu²⁺ sulfate (0.5, 1.0 mg/kg) or saline (control). Evaluations were made by hot plate (HP) and tail flick (TF) tests for central antinociceptive effect, writhing test (WT) for visceral antinociceptive effect, and activity cage (AC) test for spontaneous behavior. Zn²⁺ induced pain inhibition in HP/TF tests (up to 17%) and WT (up to 25%), with no significant differences among the salts used. Mg²⁺ salts induced pain inhibition for all performed tests (up to 85% in WT). Cu²⁺ salts showed antinociceptive effects for HP/TF (up to 28.6%) and WT (57.28%). Only Mg²⁺ and Cu²⁺ salts have displayed significant effects in AC (Mg²⁺ anxiolytic/depressant effect; Cu²⁺ anxiolytic effect). We interpret these data to mean that all tested trace elements induced antinociceptive effects in central and visceral pain tests. Our data indicate the potential use of these cheap adjuvants in pain therapy.
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Affiliation(s)
- Bogdan I Tamba
- Centre for the Study and Therapy of Pain, Gr. T. Popa University of Medicine and Pharmacy, Iasi, Romania.
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72
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Schaefer N, Vogel N, Villmann C. Glycine receptor mutants of the mouse: what are possible routes of inhibitory compensation? Front Mol Neurosci 2012; 5:98. [PMID: 23118727 PMCID: PMC3484359 DOI: 10.3389/fnmol.2012.00098] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 10/11/2012] [Indexed: 12/02/2022] Open
Abstract
Defects in glycinergic inhibition result in a complex neuromotor disorder in humans known as hyperekplexia (OMIM 149400) with similar phenotypes in rodents characterized by an exaggerated startle reflex and hypertonia. Analogous to genetic defects in humans single point mutations, microdeletions, or insertions in the Glra1 gene but also in the Glrb gene underlie the pathology in mice. The mutations either localized in the α (spasmodic, oscillator, cincinnati, Nmf11) or the β (spastic) subunit of the glycine receptor (GlyR) are much less tolerated in mice than in humans, leaving the question for the existence of different regulatory elements of the pathomechanisms in humans and rodents. In addition to the spontaneous mutations, new insights into understanding of the regulatory pathways in hyperekplexia or glycine encephalopathy arose from the constantly increasing number of knock-out as well as knock-in mutants of GlyRs. Over the last five years, various efforts using in vivo whole cell recordings provided a detailed analysis of the kinetic parameters underlying glycinergic dysfunction. Presynaptic compensation as well as postsynaptic compensatory mechanisms in these mice by other GlyR subunits or GABAA receptors, and the role of extra-synaptic GlyRs is still a matter of debate. A recent study on the mouse mutant oscillator displayed a novel aspect for compensation of functionality by complementation of receptor domains that fold independently. This review focuses on defects in glycinergic neurotransmission in mice discussed with the background of human hyperekplexia en route to strategies of compensation.
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Affiliation(s)
- Natascha Schaefer
- Emil Fischer Center, Institute of Biochemistry, University Erlangen-Nuernberg Erlangen, Germany ; Institute for Clinical Neurobiology, University of Wuerzburg Wuerzburg, Germany
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73
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Yakimovskii AF. Effects of Zinc Chloride Administered into the Striatum on Motor Behavior in Rats. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11055-012-9624-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
In 1906, Alois Alzheimer first characterized the disease that bears his name. Despite intensive research, which has led to a better understanding of the pathology, there is no effective treatment for this disease. Of the drugs approved by the US FDA, none are disease modifying, only symptomatic. Unfortunately, there have been a number of failed clinical trials in the past 10 years where studies show either no cognitive improvement or, worse, serious side effects associated with treatment. Hence, there is a need for the field to look at alternative approaches to therapy. In this review, we will discuss how metal dyshomeostasis occurs in aging and Alzheimer's disease. Concomitantly, we will discuss how targeting this dyshomeostasis offers an effective and novel therapeutic approach. Thus far, compounds that mediate these effects have shown great potential in both preclinical animal studies as well as in early-stage clinical trials.
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Wojtkiewicz J, Równiak M, Crayton R, Majewski M, Gonkowski S. Chemical coding of zinc-enriched neurons in the intramural ganglia of the porcine jejunum. Cell Tissue Res 2012; 350:215-23. [PMID: 22918698 PMCID: PMC3480586 DOI: 10.1007/s00441-012-1486-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 08/02/2012] [Indexed: 11/30/2022]
Abstract
Zinc ions in the synaptic vesicles of zinc-enriched neurons (ZEN) seem to have an important role in normal physiological and pathophysiological processes in target organ innervation. The factor directly responsible for the transport of zinc ions into synaptic vesicles is zinc transporter 3 (ZnT3), a member of the divalent cation zinc transporters and an excellent marker of ZEN neurons. As data concerning the existence of ZEN neurons in the small intestine is lacking, this study was designed to disclose the presence and neurochemical coding of such neurons in the porcine jejunum. Cryostat sections (10 mμ thick) of porcine jejunum were processed for routine double- and triple-immunofluorescence labeling for ZnT3 in various combinations with immunolabeling for other neurochemicals including pan-neuronal marker (PGP9.5), substance P (SP), somatostatin (SOM), vasoactive intestinal peptide (VIP), nitric oxide synthase (NOS), leu-enkephalin (LENK), vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), galanin (GAL), and calcitonin-gene related peptide (CGRP). Immunohistochemistry revealed that approximately 39%, 49%, and 45% of all PGP9.5- positive neurons in the jejunal myenteric (MP), outer submucous (OSP), and inner submucous (ISP) plexuses, respectively, were simultaneously ZnT3+. The majority of ZnT3+ neurons in all plexuses were also VAChT-positive. Both VAChT-positive and VAChT-negative ZnT3+ neurons co-expressed a variety of active substances with diverse patterns of co-localization depending on the plexus studied. In the MP, the largest populations among both VAChT-positive and VAChT-negative ZnT3+ neurons were NOS-positive cells. In the OSP and ISP, substantial subpopulations of ZnT3+ neurons were VAChT-positive cells co-expressing SOM and GAL, respectively. The broad-spectrum of active substances that co-localize with the ZnT3+ neurons in the porcine jejunum suggests that ZnT3 takes part in the regulation of various processes in the gut, both in normal physiological and during pathophysiological processes.
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Affiliation(s)
- Joanna Wojtkiewicz
- Faculty Medical Sciences, Department of Neurology and Neurosurgery, Stem Cell Research Laboratory, University of Warmia and Mazury, ul. Warszawska 30, 10-082, Olsztyn, Poland.
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Giménez C, Pérez-Siles G, Martínez-Villarreal J, Arribas-González E, Jiménez E, Núñez E, de Juan-Sanz J, Fernández-Sánchez E, García-Tardón N, Ibáñez I, Romanelli V, Nevado J, James VM, Topf M, Chung SK, Thomas RH, Desviat LR, Aragón C, Zafra F, Rees MI, Lapunzina P, Harvey RJ, López-Corcuera B. A novel dominant hyperekplexia mutation Y705C alters trafficking and biochemical properties of the presynaptic glycine transporter GlyT2. J Biol Chem 2012; 287:28986-9002. [PMID: 22753417 PMCID: PMC3436537 DOI: 10.1074/jbc.m111.319244] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 06/18/2012] [Indexed: 11/06/2022] Open
Abstract
Hyperekplexia or startle disease is characterized by an exaggerated startle response, evoked by tactile or auditory stimuli, producing hypertonia and apnea episodes. Although rare, this orphan disorder can have serious consequences, including sudden infant death. Dominant and recessive mutations in the human glycine receptor (GlyR) α1 gene (GLRA1) are the major cause of this disorder. However, recessive mutations in the presynaptic Na(+)/Cl(-)-dependent glycine transporter GlyT2 gene (SLC6A5) are rapidly emerging as a second major cause of startle disease. In this study, systematic DNA sequencing of SLC6A5 revealed a new dominant GlyT2 mutation: pY705C (c.2114A→G) in transmembrane domain 11, in eight individuals from Spain and the United Kingdom. Curiously, individuals harboring this mutation show significant variation in clinical presentation. In addition to classical hyperekplexia symptoms, some individuals had abnormal respiration, facial dysmorphism, delayed motor development, or intellectual disability. We functionally characterized this mutation using molecular modeling, electrophysiology, [(3)H]glycine transport, cell surface expression, and cysteine labeling assays. We found that the introduced cysteine interacts with the cysteine pair Cys-311-Cys-320 in the second external loop of GlyT2. This interaction impairs transporter maturation through the secretory pathway, reduces surface expression, and inhibits transport function. Additionally, Y705C presents altered H(+) and Zn(2+) dependence of glycine transport that may affect the function of glycinergic neurotransmission in vivo.
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Affiliation(s)
- Cecilio Giménez
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Gonzalo Pérez-Siles
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Jaime Martínez-Villarreal
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Esther Arribas-González
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Esperanza Jiménez
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Enrique Núñez
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Jaime de Juan-Sanz
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Enrique Fernández-Sánchez
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
| | - Noemí García-Tardón
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Ignacio Ibáñez
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
| | - Valeria Romanelli
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the Instituto de Genética Médica y Molecular, IdiPAZ-Hospital Universitario La Paz, Universidad Autónoma de Madrid, Madrid 28046, Spain
| | - Julián Nevado
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the Instituto de Genética Médica y Molecular, IdiPAZ-Hospital Universitario La Paz, Universidad Autónoma de Madrid, Madrid 28046, Spain
| | - Victoria M. James
- the Department of Pharmacology, University College London School of Pharmacy, London WC1N 1AX, United Kingdom
| | - Maya Topf
- the Institute of Structural and Molecular Biology, Crystallography, Birkbeck College, London WC1E 7HX, United Kingdom, and
| | - Seo-Kyung Chung
- the Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Rhys H. Thomas
- the Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Lourdes R. Desviat
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
| | - Carmen Aragón
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Francisco Zafra
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
| | - Mark I. Rees
- the Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Pablo Lapunzina
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the Instituto de Genética Médica y Molecular, IdiPAZ-Hospital Universitario La Paz, Universidad Autónoma de Madrid, Madrid 28046, Spain
| | - Robert J. Harvey
- the Department of Pharmacology, University College London School of Pharmacy, London WC1N 1AX, United Kingdom
| | - Beatriz López-Corcuera
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Madrid 28049, Spain
- the Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid 28029, Spain
- the IdiPAZ-Hospital Universitario La Paz
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Affiliation(s)
- Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark.
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78
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Neurochemical characterization of zinc transporter 3-like immunoreactive (ZnT3(+)) neurons in the intramural ganglia of the porcine duodenum. J Mol Neurosci 2012; 48:766-76. [PMID: 22791190 PMCID: PMC3447136 DOI: 10.1007/s12031-012-9855-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 07/01/2012] [Indexed: 12/24/2022]
Abstract
The SLC30 family of divalent cation transporters is thought to be involved in the transport of zinc in a variety of cellular pathways. Zinc transporter 3 (ZnT3) is involved in the transport of zinc into synaptic vesicles or intracellular organelles. As the presence of ZnT3 immunoreactive neurons has recently been reported in both the central and peripheral nervous systems of the rat, the present study was aimed at disclosing the presence of a zinc-enriched neuron enteric population in the porcine duodenum to establish a preliminary insight into their neurochemical coding. Double- and triple-immunofluorescence labeling of the porcine duodenum for ZnT3 with the pan-neuronal marker (PGP 9.5), substance P, somatostatin, vasoactive intestinal peptide (VIP), nitric oxide synthase (NOS), leu-enkephalin, vesicular acetylcholine transporter (VAChT), neuropeptide Y, galanin (GAL), and calcitonin gene-related peptide were performed. Immunohistochemistry revealed that approximately 35, 43, and 48 % of all PGP9.5-postive neurons in the myenteric (MP), outer submucous (OSP), and inner submucous (ISP) plexuses, respectively, of the porcine duodenum were simultaneously ZnT3+. In the present study, ZnT3+ neurons coexpressed a broad spectrum of active substances, but co-localization patterns unique to the plexus were studied. In the ISP, all ZnT3+ neurons were VAChT positive, and the largest populations among these cells formed ZnT3+/VAChT+/GAL+ and ZnT3+/VAChT+/VIP+ cells. In the OSP and MP, the numbers of ZnT3+/VAChT+ neurons were two times smaller, and substantial subpopulations of ZnT3+ neurons in both these plexuses formed ZnT3+/NOS+ cells. The large population of ZnT3+ neurons in the porcine duodenum and a broad spectrum of active substances which co-localize with this peptide suggest that ZnT3 takes part in the regulation of various processes in the gut both in normal physiology and during pathological processes.
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79
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Yakimovskii AF, Stepanov II. Effect of zinc chloride on picrotoxin-induced hyperkinesis depends on its concentration in solution injected into rat neostriatum. Bull Exp Biol Med 2012; 150:665-7. [PMID: 22235411 DOI: 10.1007/s10517-011-1217-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hyperkinekic effect (increase in spontaneous activity and development of choreomyoclonic hyperkinesis of the extremities and body) of picrotoxin injected into the rostral neostriatum of rats in a dose of 2 μg was reduced if the drug was injected together with ZnCl(2) in a concentration of 0.1 μg/μl. ZnCl(2) in a concentration of 1 μg/μl did not modulate the effects of picrotoxin, while in a concentration of 3 μg/μl it increased spontaneous motor activity in the open field test without affecting the symptoms of choreomyoclonic hyperkinesis.
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Affiliation(s)
- A F Yakimovskii
- Department of Normal Physiology, St. Petersburg State I. P. Pavlov Medical University, St. Petersburg, Russia.
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80
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Saadi RA, He K, Hartnett KA, Kandler K, Hershfinkel M, Aizenman E. SNARE-dependent upregulation of potassium chloride co-transporter 2 activity after metabotropic zinc receptor activation in rat cortical neurons in vitro. Neuroscience 2012; 210:38-46. [PMID: 22441041 PMCID: PMC3358579 DOI: 10.1016/j.neuroscience.2012.03.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 02/29/2012] [Accepted: 03/01/2012] [Indexed: 01/11/2023]
Abstract
The major outward chloride transporter in neurons is the potassium chloride co-transporter 2 (KCC2), critical for maintaining an inhibitory reversal potential for GABA(A) receptor channels. In a recent study, we showed that Zn(2+) regulates GABA(A) reversal potentials in the hippocampus by enhancing the activity of KCC2 through an increase in its surface expression. Zn(2+) initiates this process by activating the Gq-coupled metabotropic Zn(2+) receptor/G protein-linked receptor 39 (mZnR/GPR39). Here, we first demonstrated that mZnR/GPR39 is functional in cortical neurons in culture, and then tested the hypothesis that the increase in KCC2 activity is mediated through a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-dependent process. We established the presence of functional mZnR in rat cultured cortical neurons by loading cells with a Ca(2+) indicator and exposing cells to Zn(2+), which triggered consistent Ca(2+) responses that were blocked by the Gq antagonist YM-254890, but not by the metabotropic glutamate receptor antagonist (RS)-α-methyl-4-carboxyphenylglycine (MCPG). Importantly, Zn(2+) treatment under these conditions did not increase the intracellular concentrations of Zn(2+) itself. We then measured KCC2 activity by monitoring both the rate and relative amount of furosemide-sensitive NH(4)(+) influx through the co-transporter using an intracellular pH-sensitive fluorescent indicator. We observed that Zn(2+) pretreatment induced a Ca(2+)-dependent increase in KCC2 activity. The effects of Zn(2+) on KCC2 activity were also observed in wild-type mouse cortical neurons in culture, but not in neurons obtained from mZnR/GPR39(-/-) mice, suggesting that Zn(2+) acts through mZnR/GPR39 activation to upregulate KCC2 activity. We next transfected rat cortical neurons with a plasmid encoding botulinum toxin C1 (Botox C1), which cleaves the SNARE proteins syntaxin 1 and synaptosomal-associated protein 25 (SNAP-25). Basal KCC2 activity was similar in both transfected and non-transfected neurons. Non-transfected cells, or cells transfected with marker vector alone, showed a Zn(2+)-dependent increase in KCC2 activity. In contrast, KCC2 activity in neurons expressing Botox C1 was unchanged by Zn(2+). These results suggest that SNARE proteins are necessary for the increased activity of KCC2 after Zn(2+) stimulation of mZnR/GPR39.
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Affiliation(s)
- Robert A. Saadi
- Department of Neurobiology, University of University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, U.S.A
| | - Kai He
- Department of Neurobiology, University of University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, U.S.A
| | - Karen A. Hartnett
- Department of Neurobiology, University of University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, U.S.A
| | - Karl Kandler
- Department of Neurobiology, University of University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, U.S.A
- Department of Otolaryngology, University of University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, U.S.A
| | - Michal Hershfinkel
- Department of Morphology, Ben-Gurion University, Faculty of Health Sciences, Beer-Sheva 84105, Israel
| | - Elias Aizenman
- Department of Neurobiology, University of University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, U.S.A
- Department of Morphology, Ben-Gurion University, Faculty of Health Sciences, Beer-Sheva 84105, Israel
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81
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Histamine-gated ion channels in mammals? Biochem Pharmacol 2012; 83:1127-35. [DOI: 10.1016/j.bcp.2011.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/07/2011] [Accepted: 12/09/2011] [Indexed: 01/29/2023]
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82
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Abstract
Inhibitory (or strychnine sensitive) glycine receptors (GlyRs) are anion-selective transmitter-gated ion channels of the cys-loop superfamily, which includes among others also the inhibitory γ-aminobutyric acid receptors (GABA(A) receptors). While GABA mediates fast inhibitory neurotransmission throughout the CNS, the action of glycine as a fast inhibitory neurotransmitter is more restricted. This probably explains why GABA(A) receptors constitute a group of extremely successful drug targets in the treatment of a wide variety of CNS diseases, including anxiety, sleep disorders and epilepsy, while drugs specifically targeting GlyRs are virtually lacking. However, the spatially more restricted distribution of glycinergic inhibition may be advantageous in situations when a more localized enhancement of inhibition is sought. Inhibitory GlyRs are particularly relevant for the control of excitability in the mammalian spinal cord, brain stem and a few selected brain areas, such as the cerebellum and the retina. At these sites, GlyRs regulate important physiological functions, including respiratory rhythms, motor control, muscle tone and sensory as well as pain processing. In the hippocampus, RNA-edited high affinity extrasynaptic GlyRs may contribute to the pathology of temporal lobe epilepsy. Although specific modulators have not yet been identified, GlyRs still possess sites for allosteric modulation by a number of structurally diverse molecules, including alcohols, neurosteroids, cannabinoids, tropeines, general anaesthetics, certain neurotransmitters and cations. This review summarizes the present knowledge about this modulation and the molecular bases of the interactions involved.
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Affiliation(s)
- Gonzalo E Yevenes
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
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83
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Hare DJ, Lee JK, Beavis AD, van Gramberg A, George J, Adlard PA, Finkelstein DI, Doble PA. Three-dimensional atlas of iron, copper, and zinc in the mouse cerebrum and brainstem. Anal Chem 2012; 84:3990-7. [PMID: 22462591 DOI: 10.1021/ac300374x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Atlases depicting molecular and functional features of the brain are becoming an integral part of modern neuroscience. In this study we used laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) to quantitatively measure iron (Fe), copper (Cu), and zinc (Zn) levels in a serially sectioned C57BL/6 mouse brain (cerebrum and brainstem). Forty-six sections were analyzed in a single experiment of approximately 158 h in duration. We constructed a 46-plate reference atlas by aligning quantified images of metal distribution with corresponding coronal sections from the Allen Mouse Brain Reference Atlas. The 46 plates were also used to construct three-dimensional models of Fe, Cu, and Zn distribution. This atlas represents the first reconstruction of quantitative trace metal distribution through the brain by LA-ICPMS and will facilitate the study of trace metals in the brain and help to elucidate their role in neurobiology.
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Affiliation(s)
- Dominic J Hare
- Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales, Australia.
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84
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Tayeb HO, Yang HD, Price BH, Tarazi FI. Pharmacotherapies for Alzheimer's disease: Beyond cholinesterase inhibitors. Pharmacol Ther 2012; 134:8-25. [DOI: 10.1016/j.pharmthera.2011.12.002] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 11/21/2011] [Indexed: 12/31/2022]
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85
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Xu H, Gao HL, Zheng W, Xin N, Chi ZH, Bai SL, Wang ZY. Lactational zinc deficiency-induced hippocampal neuronal apoptosis by a BDNF-independent TrkB signaling pathway. Hippocampus 2012; 21:495-501. [PMID: 20101602 DOI: 10.1002/hipo.20767] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
It is well-known that zinc deficiency leads to neuronal death in the brain. Here we tested the hypothesis that changes in the TrkB signaling pathway are involved in hippocampal neuronal apoptosis of suckling offspring with maternal zinc deficiency. Postpartum mice were fed a zinc-deficient (0.85 ppm) diet and their offspring were used as a lactational zinc deficiency mouse model. At P7, P14, and P21, changes in hippocampal neuronal apoptosis were assessed by Nissl and TUNEL staining. BDNF levels and TrkB neurotrophic signaling were examined using immunoblotting assay. Lactational zinc deficiency resulted in lower levels of p-TrkB and p-ERK, and higher levels of Bax/Bcl-2 and caspase-3 in the hippocampus, suggesting that zinc deficiency-induced low levels of TrkB phosphorylation would abrogate the downstream ERK signaling pathway, leading to hippocampal neuronal apoptosis. Most interestingly, our data showed that the activity of Src, a key molecule for zinc-induced TrkB activation through the BDNF-independent pathway, was inhibited significantly, and the expression levels of BDNF were significantly increased in the hippocampus of suckling mice. The present data indicate that zinc depletion-induced hippocampal neuronal apoptosis is likely through modulation of the TrkB neurotrophic signaling pathway by a BDNF-independent and Src-dependent mechanism, whereas higher expression of BDNF is considered as a protective response, which cannot fully compensate for the injury caused by maternal zinc deficiency.
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Affiliation(s)
- He Xu
- Key Laboratory of Cell Biology of Ministry of Public Health of China, College of Basic Medical Sciences, China Medical University, Shenyang 110001, People's Republic of China
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86
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Aiba I, Carlson AP, Sheline CT, Shuttleworth CW. Synaptic release and extracellular actions of Zn2+ limit propagation of spreading depression and related events in vitro and in vivo. J Neurophysiol 2012; 107:1032-41. [PMID: 22131381 PMCID: PMC3289481 DOI: 10.1152/jn.00453.2011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 11/29/2011] [Indexed: 11/22/2022] Open
Abstract
Cortical spreading depression (CSD) is a consequence of a slowly propagating wave of neuronal and glial depolarization (spreading depolarization; SD). Massive release of glutamate contributes to SD propagation, and it was recently shown that Zn(2+) is also released from synaptic vesicles during SD. The present study examined consequences of extracellular Zn(2+) accumulation on the propagation of SD. SD mechanisms were studied first in murine brain slices, using focal KCl applications as stimuli and making electrical and optical recordings in hippocampal area CA1. Elevating extracellular Zn(2+) concentrations with exogenous ZnCl(2) reduced SD propagation rates. Selective chelation of endogenous Zn(2+) (using TPEN or CaEDTA) increased SD propagation rates, and these effects appeared due to chelation of Zn(2+) derived from synaptic vesicles. Thus, in tissues where synaptic Zn(2+) release was absent [knockout (KO) of vesicular Zn(2+) transporter ZnT-3], SD propagation rates were increased, and no additional increase was observed following chelation of endogenous Zn(2+) in these tissues. The role of synaptic Zn(2+) was then examined on CSD in vivo. ZnT-3 KO animals had higher susceptibility to CSD than wild-type controls as evidenced by significantly higher propagation rates and frequencies. Studies of candidate mechanisms excluded changes in neuronal excitability, presynaptic release, and GABA receptors but left open a possible contribution of N-methyl-d-aspartate (NMDA) receptor inhibition. These results suggest the extracellular accumulation of synaptically released Zn(2+) can serve as an intrinsic inhibitor to limit SD events. The inhibitory action of extracellular Zn(2+) on SD may counteract to some extent the neurotoxic effects of intracellular Zn(2+) accumulation in acute brain injury models.
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Affiliation(s)
- Isamu Aiba
- Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA
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87
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Sadiq S, Ghazala Z, Chowdhury A, Büsselberg D. Metal toxicity at the synapse: presynaptic, postsynaptic, and long-term effects. J Toxicol 2012; 2012:132671. [PMID: 22287959 PMCID: PMC3263637 DOI: 10.1155/2012/132671] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 07/05/2011] [Indexed: 12/19/2022] Open
Abstract
Metal neurotoxicity is a global health concern. This paper summarizes the evidence for metal interactions with synaptic transmission and synaptic plasticity. Presynaptically metal ions modulate neurotransmitter release through their interaction with synaptic vesicles, ion channels, and the metabolism of neurotransmitters (NT). Many metals (e.g., Pb(2+), Cd(2+), and Hg(+)) also interact with intracellular signaling pathways. Postsynaptically, processes associated with the binding of NT to their receptors, activation of channels, and degradation of NT are altered by metals. Zn(2+), Pb(2+), Cu(2+), Cd(2+), Ni(2+), Co(2+), Li(3+), Hg(+), and methylmercury modulate NMDA, AMPA/kainate, and/or GABA receptors activity. Al(3+), Pb(2+), Cd(2+), and As(2)O(3) also impair synaptic plasticity by targeting molecules such as CaM, PKC, and NOS as well as the transcription machinery involved in the maintenance of synaptic plasticity. The multiple effects of metals might occur simultaneously and are based on the specific metal species, metal concentrations, and the types of neurons involved.
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Affiliation(s)
| | | | | | - Dietrich Büsselberg
- Weill Cornell Medical College in Qatar, Qatar Foundation—Education City, P.O. Box 24144, Doha, Qatar
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88
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Alfonso J, Le Magueresse C, Zuccotti A, Khodosevich K, Monyer H. Diazepam Binding Inhibitor Promotes Progenitor Proliferation in the Postnatal SVZ by Reducing GABA Signaling. Cell Stem Cell 2012; 10:76-87. [DOI: 10.1016/j.stem.2011.11.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 08/31/2011] [Accepted: 11/10/2011] [Indexed: 02/01/2023]
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89
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García-Colunga J, Godoy-García U, Vázquez-Gómez E. Interaction of bupropion and zinc with neuronal nicotinic acetylcholine receptors. Neuropharmacology 2011; 61:1202-9. [DOI: 10.1016/j.neuropharm.2011.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 06/06/2011] [Accepted: 07/10/2011] [Indexed: 12/28/2022]
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90
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Roberts BR, Ryan TM, Bush AI, Masters CL, Duce JA. The role of metallobiology and amyloid-β peptides in Alzheimer’s disease. J Neurochem 2011; 120 Suppl 1:149-166. [DOI: 10.1111/j.1471-4159.2011.07500.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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91
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Isaev NK, Lozier ER, Novikova SV, Silachev DN, Zorov DB, Stelmashook EV. Glucose starvation stimulates Zn2+ toxicity in cultures of cerebellar granule neurons. Brain Res Bull 2011; 87:80-4. [PMID: 22079503 DOI: 10.1016/j.brainresbull.2011.10.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 10/24/2011] [Accepted: 10/26/2011] [Indexed: 11/25/2022]
Abstract
Zinc chloride (0.02 mM, 3h) did not have any influence on the survival of cerebellar granule neurons (CGNs) incubated in balanced salt solution (BSS). However, in the absence of glucose ZnCl(2) caused severe neuronal damage, decreasing cell survival to 12±2%. Either the blockade of ionotropic glutamate NMDA-receptors with MK-801 or APV or supplementation the medium with ruthenium red (mitochondrial Ca(2+) uniporter blocker) almost entirely protected CGNs from the toxic effect of ZnCl(2) during glucose deprivation (GD). However, NBQX (AMPA/kainate glutamate receptor blocker) did not show protective effect. Measurements of intracellular calcium ions concentration using fluorescent probe (Fluo-4 AM) and zinc ions (FluoZin-3AM) demonstrated that 1.5h-exposure to GD induced intensive increase of Fluo-4 fluorescence and small increase of FluoZin-3 fluorescence in neurons. The supplementation of medium with ZnCl(2) caused equal increase of FluoZin-3 fluorescence at both GD and normoglycemia, whereas the potentiation of Fluo-4 fluorescence by zinc was observed only under GD and could be prevented by MK-801. However, neither MK-801 nor NBQX could influence [Zn(2+)](i) increase caused by zinc addition under GD, while ruthenium red did cause significant increase of [Zn(2+)](i). This data implies that zinc ions during GD induce an additional overload of CGNs with calcium ions that get transported through activated NMDA-channel. Zinc and calcium ions accumulate in mitochondria and amplify individual destructive action on these organelles leading to neuronal death.
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Affiliation(s)
- Nickolay K Isaev
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia.
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92
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Chorin E, Vinograd O, Fleidervish I, Gilad D, Herrmann S, Sekler I, Aizenman E, Hershfinkel M. Upregulation of KCC2 activity by zinc-mediated neurotransmission via the mZnR/GPR39 receptor. J Neurosci 2011; 31:12916-26. [PMID: 21900570 PMCID: PMC3227684 DOI: 10.1523/jneurosci.2205-11.2011] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/12/2011] [Accepted: 07/14/2011] [Indexed: 12/15/2022] Open
Abstract
Vesicular Zn(2+) regulates postsynaptic neuronal excitability upon its corelease with glutamate. We previously demonstrated that synaptic Zn(2+) acts via a distinct metabotropic zinc-sensing receptor (mZnR) in neurons to trigger Ca(2+) responses in the hippocampus. Here, we show that physiological activation of mZnR signaling induces enhanced K(+)/Cl(-) cotransporter 2 (KCC2) activity and surface expression. As KCC2 is the major Cl(-) outward transporter in neurons, Zn(2+) also triggers a pronounced hyperpolarizing shift in the GABA(A) reversal potential. Mossy fiber stimulation-dependent upregulation of KCC2 activity is eliminated in slices from Zn(2+) transporter 3-deficient animals, which lack synaptic Zn(2+). Importantly, activity-dependent ZnR signaling and subsequent enhancement of KCC2 activity are also absent in slices from mice lacking the G-protein-coupled receptor GPR39, identifying this protein as the functional neuronal mZnR. Our work elucidates a fundamentally important role for synaptically released Zn(2+) acting as a neurotransmitter signal via activation of a mZnR to increase Cl(-) transport, thereby enhancing inhibitory tone in postsynaptic cells.
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MESH Headings
- Animals
- Blotting, Western
- CA3 Region, Hippocampal/cytology
- CA3 Region, Hippocampal/physiology
- Electrophysiological Phenomena
- Excitatory Postsynaptic Potentials/physiology
- Female
- Genotype
- In Vitro Techniques
- Male
- Mice
- Mice, Knockout
- Microscopy, Fluorescence
- Mossy Fibers, Hippocampal/physiology
- Patch-Clamp Techniques
- Receptors, Cell Surface/metabolism
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/genetics
- Receptors, GABA-A/drug effects
- Reverse Transcriptase Polymerase Chain Reaction
- Symporters/biosynthesis
- Symporters/physiology
- Synapses/metabolism
- Synaptic Transmission/drug effects
- Up-Regulation/drug effects
- Zinc/metabolism
- Zinc/pharmacology
- K Cl- Cotransporters
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Affiliation(s)
| | | | - Ilya Fleidervish
- Physiology, Faculty of Health Sciences and The Zlotowski Center of Neuroscience, Ben-Gurion University, Beer-Sheva, 84015, Israel, and
| | | | - Sharon Herrmann
- Physiology, Faculty of Health Sciences and The Zlotowski Center of Neuroscience, Ben-Gurion University, Beer-Sheva, 84015, Israel, and
| | - Israel Sekler
- Physiology, Faculty of Health Sciences and The Zlotowski Center of Neuroscience, Ben-Gurion University, Beer-Sheva, 84015, Israel, and
| | - Elias Aizenman
- Departments of Morphology and
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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93
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Grabrucker AM, Rowan M, Garner CC. Brain-Delivery of Zinc-Ions as Potential Treatment for Neurological Diseases: Mini Review. DRUG DELIVERY LETTERS 2011; 1:13-23. [PMID: 22102982 PMCID: PMC3220161 DOI: 10.2174/2210303111101010013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Homeostasis of metal ions such as Zn(2+) is essential for proper brain function. Moreover, the list of psychiatric and neurodegenerative disorders involving a dysregulation of brain Zn(2+)-levels is long and steadily growing, including Parkinson's and Alzheimer's disease as well as schizophrenia, attention deficit and hyperactivity disorder, depression, amyotrophic lateral sclerosis, Down's syndrome, multiple sclerosis, Wilson's disease and Pick's disease. Furthermore, alterations in Zn(2+)-levels are seen in transient forebrain ischemia, seizures, traumatic brain injury and alcoholism. Thus, the possibility of altering Zn(2+)-levels within the brain is emerging as a new target for the prevention and treatment of psychiatric and neurological diseases. Although the role of Zn(2+) in the brain has been extensively studied over the past decades, methods for controlled regulation and manipulation of Zn(2+) concentrations within the brain are still in their infancy. Since the use of dietary Zn(2+) supplementation and restriction has major limitations, new methods and alternative approaches are currently under investigation, such as the use of intracranial infusion of Zn(2+) chelators or nanoparticle technologies to elevate or decrease intracellular Zn(2+) levels. Therefore, this review briefly summarizes the role of Zn(2+) in psychiatric and neurodegenerative diseases and highlights key findings and impediments of brain Zn(2+)-level manipulation. Furthermore, some methods and compounds, such as metal ion chelation, redistribution and supplementation that are used to control brain Zn(2+)-levels in order to treat brain disorders are evaluated.
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Affiliation(s)
- Andreas M. Grabrucker
- Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Magali Rowan
- Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Craig C. Garner
- Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Stanford University, Stanford, CA, USA
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94
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Molecular sites for the positive allosteric modulation of glycine receptors by endocannabinoids. PLoS One 2011; 6:e23886. [PMID: 21901142 PMCID: PMC3162021 DOI: 10.1371/journal.pone.0023886] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 07/29/2011] [Indexed: 11/19/2022] Open
Abstract
Glycine receptors (GlyRs) are transmitter-gated anion channels of the Cys-loop superfamily which mediate synaptic inhibition at spinal and selected supraspinal sites. Although they serve pivotal functions in motor control and sensory processing, they have yet to be exploited as drug targets partly because of hitherto limited possibilities for allosteric control. Endocannabinoids (ECs) have recently been characterized as direct allosteric GlyR modulators, but the underlying molecular sites have remained unknown. Here, we show that chemically neutral ECs (e.g. anandamide, AEA) are positive modulators of α1, α2 and α3 GlyRs, whereas acidic ECs (e.g. N-arachidonoyl-glycine; NA-Gly) potentiate α1 GlyRs but inhibit α2 and α3. This subunit-specificity allowed us to identify the underlying molecular sites through analysis of chimeric and mutant receptors. We found that alanine 52 in extracellular loop 2, glycine 254 in transmembrane (TM) region 2 and intracellular lysine 385 determine the positive modulation of α1 GlyRs by NA-Gly. Successive substitution of non-conserved extracellular and TM residues in α2 converted NA-Gly-mediated inhibition into potentiation. Conversely, mutation of the conserved lysine within the intracellular loop between TM3 and TM4 attenuated NA-Gly-mediated potentiation of α1 GlyRs, without affecting inhibition of α2 and α3. Notably, this mutation reduced modulation by AEA of all three GlyRs. These results define molecular sites for allosteric control of GlyRs by ECs and reveal an unrecognized function for the TM3-4 intracellular loop in the allosteric modulation of Cys-loop ion channels. The identification of these sites may help to understand the physiological role of this modulation and facilitate the development of novel therapeutic approaches to diseases such as spasticity, startle disease and possibly chronic pain.
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95
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Zinc effects on NMDA receptor gating kinetics. Biophys J 2011; 100:1910-8. [PMID: 21504727 DOI: 10.1016/j.bpj.2011.02.042] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 02/14/2011] [Accepted: 02/23/2011] [Indexed: 12/24/2022] Open
Abstract
Zinc accumulates in the synaptic vesicles of certain glutamatergic forebrain neurons and modulates neuronal excitability and synaptic plasticity by multiple poorly understood mechanisms. Zinc directly inhibits NMDA-sensitive glutamate-gated channels by two separate mechanisms: high-affinity binding to N-terminal domains of GluN2A subunits reduces channel open probability, and low-affinity voltage-dependent binding to pore-lining residues blocks the channel. Insight into the high-affinity allosteric effect has been hampered by the receptor's complex gating; multiple, sometimes coupled, modulatory mechanisms; and practical difficulties in avoiding transient block by residual Mg(2+). To sidestep these challenges, we examined how nanomolar zinc concentrations changed the gating kinetics of individual block-resistant receptors. We found that block-insensitive channels had lower intrinsic open probabilities but retained high sensitivity to zinc inhibition. Binding of zinc to these receptors resulted in longer closures and shorter openings within bursts of activity but had no effect on interburst intervals. Based on kinetic modeling of these data, we conclude that zinc-bound receptors have higher energy barriers to opening and less stable open states. We tested this model for its ability to predict zinc-dependent changes in macroscopic responses and to infer the impact of nanomolar zinc concentrations on synaptic currents mediated by 2A-type NMDA receptors.
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96
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Kim NK, Robinson HPC. Effects of divalent cations on slow unblock of native NMDA receptors in mouse neocortical pyramidal neurons. Eur J Neurosci 2011; 34:199-212. [PMID: 21722211 DOI: 10.1111/j.1460-9568.2011.07768.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The N-methyl-D-aspartate receptor (NMDAR) exhibits strong voltage-dependent block by extracellular Mg(2+) , which is relieved by sustained depolarization and glutamate binding, and which is central to the function of the NMDAR in synaptic plasticity. Rapid membrane depolarization during agonist application reveals a slow unblock of NMDARs, which has important functional implications, for example in the generation of NMDAR spikes, and in determining the narrow time window for spike-timing-dependent plasticity. However, its mechanism is still unclear. Here, we study unblock of divalent cations in native NMDARs in nucleated patches isolated from mouse cortical layer 2/3 pyramidal neurons. Comparing unblock kinetics of NMDARs in the presence of extracellular Mg(2+) or in nominally zero Mg(2+) , and with Mn(2+) or Co(2+) substituting for Mg(2+) , we found that the properties of slow unblock were determined by the identity of the blocking metal ion at the binding site, presumably by affecting the operation of a structural link to channel gating. The time course of slow unblock was not affected by zinc, or the zinc chelator TPEN [N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylenediamine], while the slower fraction of unblock was reduced by ifenprodil, an NR2B-selective antagonist. Slow unblock was only weakly temperature dependent, speeding up with rise in temperature with a Q(10) of ≈1.5. Finally, using action potential waveform voltage-clamp, we show that this slow relief from divalent cation block is a prominent feature in physiologically realistic patterns of changing membrane potential.
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Affiliation(s)
- Nam-Kyung Kim
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
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97
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Nozaki C, Vergnano AM, Filliol D, Ouagazzal AM, Le Goff A, Carvalho S, Reiss D, Gaveriaux-Ruff C, Neyton J, Paoletti P, Kieffer BL. Zinc alleviates pain through high-affinity binding to the NMDA receptor NR2A subunit. Nat Neurosci 2011; 14:1017-22. [PMID: 21725314 DOI: 10.1038/nn.2844] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 04/19/2011] [Indexed: 02/07/2023]
Abstract
Zinc is abundant in the central nervous system and regulates pain, but the underlying mechanisms are unknown. In vitro studies have shown that extracellular zinc modulates a plethora of signaling membrane proteins, including NMDA receptors containing the NR2A subunit, which display exquisite zinc sensitivity. We created NR2A-H128S knock-in mice to investigate whether Zn2+-NR2A interaction influences pain control. In these mice, high-affinity (nanomolar) zinc inhibition of NMDA currents was lost in the hippocampus and spinal cord. Knock-in mice showed hypersensitivity to radiant heat and capsaicin, and developed enhanced allodynia in inflammatory and neuropathic pain models. Furthermore, zinc-induced analgesia was completely abolished under both acute and chronic pain conditions. Our data establish that zinc is an endogenous modulator of excitatory neurotransmission in vivo and identify a new mechanism in pain processing that relies on NR2A NMDA receptors. The study also potentially provides a molecular basis for the pain-relieving effects of dietary zinc supplementation.
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Affiliation(s)
- Chihiro Nozaki
- Institut de Génétique et Biologie Moléculaire et Cellulaire, Illkirch, France
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98
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Fukada T, Yamasaki S, Nishida K, Murakami M, Hirano T. Zinc homeostasis and signaling in health and diseases: Zinc signaling. J Biol Inorg Chem 2011; 16:1123-34. [PMID: 21660546 PMCID: PMC3176402 DOI: 10.1007/s00775-011-0797-4] [Citation(s) in RCA: 396] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 05/09/2011] [Indexed: 11/26/2022]
Abstract
The essential trace element zinc (Zn) is widely required in cellular functions, and abnormal Zn homeostasis causes a variety of health problems that include growth retardation, immunodeficiency, hypogonadism, and neuronal and sensory dysfunctions. Zn homeostasis is regulated through Zn transporters, permeable channels, and metallothioneins. Recent studies highlight Zn's dynamic activity and its role as a signaling mediator. Zn acts as an intracellular signaling molecule, capable of communicating between cells, converting extracellular stimuli to intracellular signals, and controlling intracellular events. We have proposed that intracellular Zn signaling falls into two classes, early and late Zn signaling. This review addresses recent findings regarding Zn signaling and its role in physiological processes and pathogenesis.
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Affiliation(s)
- Toshiyuki Fukada
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
- Laboratory of Allergy and Immunology, Graduate School of Medicine, Osaka University, Osaka, 565-0871 Japan
| | - Satoru Yamasaki
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
| | - Keigo Nishida
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
- Immune System, Cooperation Program, Graduate School of Frontier Biosciences, Osaka University, Osaka, 565-0871 Japan
| | - Masaaki Murakami
- Laboratories of Developmental Immunology, JST-CREST, Graduate School of Frontier Biosciences, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Osaka, 565-0871 Japan
| | - Toshio Hirano
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
- Laboratories of Developmental Immunology, JST-CREST, Graduate School of Frontier Biosciences, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Osaka, 565-0871 Japan
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99
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Stawicki TM, Zhou K, Yochem J, Chen L, Jin Y. TRPM channels modulate epileptic-like convulsions via systemic ion homeostasis. Curr Biol 2011; 21:883-8. [PMID: 21549603 PMCID: PMC4034270 DOI: 10.1016/j.cub.2011.03.070] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/28/2011] [Accepted: 03/29/2011] [Indexed: 11/24/2022]
Abstract
Neuronal networks operate over a wide range of activity levels, with both neuronal and nonneuronal cells contributing to the balance of excitation and inhibition. Activity imbalance within neuronal networks underlies many neurological diseases, such as epilepsy. The Caenorhabditis elegans locomotor circuit operates via coordinated activity of cholinergic excitatory and GABAergic inhibitory transmission. We have previously shown that a gain-of-function mutation in a neuronal acetylcholine receptor, acr-2(gf), causes an epileptic-like convulsion behavior. Here we report that the behavioral and physiological effects of acr-2(gf) require the activity of the TRPM channel GTL-2 in nonneuronal tissues. Loss of gtl-2 function does not affect baseline synaptic transmission but can compensate for the excitation-inhibition imbalance caused by acr-2(gf). The compensatory effects of removing gtl-2 are counterbalanced by another TRPM channel, GTL-1, and can be recapitulated by acute treatment with divalent cation chelators, including those specific for Zn(2+). Together, these data reveal an important role for ion homeostasis in the balance of neuronal network activity and a novel function of nonneuronal TRPM channels in the fine-tuning of this network activity.
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Affiliation(s)
- Tamara M. Stawicki
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, CA92093, USA
- Neurosciences graduate program, Univ. Calif. San Diego
| | - Keming Zhou
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, CA92093, USA
| | - John Yochem
- Department of Genetics, Cell Biology and Development, Developmental Biology Center, University of Minnesota, Minneapolis, MN55455, USA
| | - Lihsia Chen
- Department of Genetics, Cell Biology and Development, Developmental Biology Center, University of Minnesota, Minneapolis, MN55455, USA
| | - Yishi Jin
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, CA92093, USA
- Neurosciences graduate program, Univ. Calif. San Diego
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA92093, USA
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100
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Kenche VB, Barnham KJ. Alzheimer's disease & metals: therapeutic opportunities. Br J Pharmacol 2011; 163:211-9. [PMID: 21232050 PMCID: PMC3087126 DOI: 10.1111/j.1476-5381.2011.01221.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/15/2010] [Accepted: 12/21/2010] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is the most common age related neurodegenerative disease. Currently, there are no disease modifying drugs, existing therapies only offer short-term symptomatic relief. Two of the pathognomonic indicators of AD are the presence of extracellular protein aggregates consisting primarily of the Aβ peptide and oxidative stress. Both of these phenomena can potentially be explained by the interactions of Aβ with metal ions. In addition, metal ions play a pivotal role in synaptic function and their homeostasis is tightly regulated. A breakdown in this metal homeostasis and the generation of toxic Aβ oligomers are likely to be responsible for the synaptic dysfunction associated with AD. Therefore, approaches that are designed to prevent Aβ metal interactions, inhibiting the formation of toxic Aβ species as well as restoring metal homeostasis may have potential as disease modifying strategies for treating AD. This review summarizes the physiological and pathological interactions that metal ions play in synaptic function with particular emphasis placed on interactions with Aβ. A variety of therapeutic strategies designed to address these pathological processes are also described. The most advanced of these strategies is the so-called 'metal protein attenuating compound' approach, with the lead molecule PBT2 having successfully completed early phase clinical trials. The success of these various strategies suggests that manipulating metal ion interactions offers multiple opportunities to develop disease modifying therapies for AD.
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Affiliation(s)
- Vijaya B Kenche
- The Mental Health Research Institute, The University of MelbourneParkville, Vic., Australia
- Department of Pathology, The University of MelbourneParkville, Vic., Australia
- Bio21 Molecular Science & Biotechnology Institute, The University of MelbourneParkville, Vic., Australia
| | - Kevin J Barnham
- The Mental Health Research Institute, The University of MelbourneParkville, Vic., Australia
- Department of Pathology, The University of MelbourneParkville, Vic., Australia
- Bio21 Molecular Science & Biotechnology Institute, The University of MelbourneParkville, Vic., Australia
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