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Ferranco A, Basak S, Lough A, Kraatz HB. Metal coordination of ferrocene–histidine conjugates. Dalton Trans 2017; 46:4844-4859. [PMID: 28349138 DOI: 10.1039/c7dt00456g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Synthesis and complete structural characterization of ferrocene–histidine dipeptides including detailed analysis of the ligand–metal complexation.
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Affiliation(s)
- Annaleizle Ferranco
- Department of Physical and Environmental Sciences
- University of Toronto
- Toronto
- M1C 1A4 Canada
- Department of Chemistry
| | - Shibaji Basak
- Department of Physical and Environmental Sciences
- University of Toronto
- Toronto
- M1C 1A4 Canada
- Department of Chemistry
| | - Alan Lough
- Department of Chemistry
- University of Toronto
- Toronto
- M5S 3H6 Canada
| | - Heinz-Bernhard Kraatz
- Department of Physical and Environmental Sciences
- University of Toronto
- Toronto
- M1C 1A4 Canada
- Department of Chemistry
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52
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Takeda A, Tamano H. New Insight into Metallomics in Cognition. Metallomics 2017. [DOI: 10.1007/978-4-431-56463-8_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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53
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Acosta DDS, Danielle NM, Altenhofen S, Luzardo MD, Costa PG, Bianchini A, Bonan CD, da Silva RS, Dafre AL. Copper at low levels impairs memory of adult zebrafish (Danio rerio) and affects swimming performance of larvae. Comp Biochem Physiol C Toxicol Pharmacol 2016; 185-186:122-130. [PMID: 27012768 DOI: 10.1016/j.cbpc.2016.03.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 03/15/2016] [Accepted: 03/15/2016] [Indexed: 11/20/2022]
Abstract
Metal contamination at low levels is an important issue because it usually produces health and environmental effects, either positive or deleterious. Contamination of surface waters with copper (Cu) is a worldwide event, usually originated by mining, agricultural, industrial, commercial, and residential activities. Water quality criteria for Cu are variable among countries but allowed limits are generally in the μg/L range, which can disrupt several functions in the early life-stages of fish species. Behavioral and biochemical alterations after Cu exposure have also been described at concentrations close to the allowed limits. Aiming to search for the effects of Cu in the range of the allowed limits, larvae and adult zebrafish (Danio rerio) were exposed to different concentrations of dissolved Cu (nominally: 0, 5, 9, 20 and 60μg/L; measured: 0.4, 5.7, 7.2 16.6 and 42.3μg/L, respectively) for 96h. Larvae swimming and body length, and adult behavior and biochemical biomarkers (activity of glutathione-related enzymes in gills, muscle, and brain) were assessed after Cu exposure. Several effects were observed in fish exposed to 9μg/L nominal Cu, including increased larvae swimming distance and velocity, abolishment of adult inhibitory avoidance memory, and decreased glutathione S-transferase (GST) activity in gills of adult fish. At the highest Cu concentration tested (nominally: 60μg/L), body length of larvae, spatial memory of adults, and gill GST activity were decreased. Social behavior (aggressiveness and conspecific interaction), and glutathione reductase (GR) activity were not affected in adult zebrafish. Exposure to Cu, at concentrations close to the water quality criteria for this metal in fresh water, was able to alter larvae swimming performance and to induce detrimental effects on the behavior of adult zebrafish, thus indicating the need for further studies to reevaluate the currently allowed limits for Cu in fresh water.
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Affiliation(s)
- Daiane da Silva Acosta
- Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, 88040-900, Florianopolis, SC, Brazil
| | - Naissa Maria Danielle
- Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, 88040-900, Florianopolis, SC, Brazil
| | - Stefani Altenhofen
- Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil
| | - Milene Dornelles Luzardo
- Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil
| | - Patrícia Gomes Costa
- Institute of Biological Sciences, Federal University of Rio Grande, 96203-900 Rio Grande, RS, Brazil
| | - Adalto Bianchini
- Institute of Biological Sciences, Federal University of Rio Grande, 96203-900 Rio Grande, RS, Brazil
| | - Carla Denise Bonan
- Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil
| | - Rosane Souza da Silva
- Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil
| | - Alcir Luiz Dafre
- Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, 88040-900, Florianopolis, SC, Brazil.
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Voisin T, Bourinet E, Lory P. Genetic alteration of the metal/redox modulation of Cav3.2 T-type calcium channel reveals its role in neuronal excitability. J Physiol 2016; 594:3561-74. [PMID: 26931411 DOI: 10.1113/jp271925] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/29/2016] [Indexed: 02/06/2023] Open
Abstract
KEY POINTS In this study, we describe a new knock-in (KI) mouse model that allows the study of the H191-dependent regulation of T-type Cav3.2 channels. Sensitivity to zinc, nickel and ascorbate of native Cav3.2 channels is significantly impeded in the dorsal root ganglion (DRG) neurons of this KI mouse. Importantly, we describe that this H191-dependent regulation has discrete but significant effects on the excitability properties of D-hair (down-hair) cells, a sub-population of DRG neurons in which Cav3.2 currents prominently regulate excitability. Overall, this study reveals that the native H191-dependent regulation of Cav3.2 channels plays a role in the excitability of Cav3.2-expressing neurons. This animal model will be valuable in addressing the potential in vivo roles of the trace metal and redox modulation of Cav3.2 T-type channels in a wide range of physiological and pathological conditions. ABSTRACT Cav3.2 channels are T-type voltage-gated calcium channels that play important roles in controlling neuronal excitability, particularly in dorsal root ganglion (DRG) neurons where they are involved in touch and pain signalling. Cav3.2 channels are modulated by low concentrations of metal ions (nickel, zinc) and redox agents, which involves the histidine 191 (H191) in the channel's extracellular IS3-IS4 loop. It is hypothesized that this metal/redox modulation would contribute to the tuning of the excitability properties of DRG neurons. However, the precise role of this H191-dependent modulation of Cav3.2 channel remains unresolved. Towards this goal, we have generated a knock-in (KI) mouse carrying the mutation H191Q in the Cav3.2 protein. Electrophysiological studies were performed on a subpopulation of DRG neurons, the D-hair cells, which express large Cav3.2 currents. We describe an impaired sensitivity to zinc, nickel and ascorbate of the T-type current in D-hair neurons from KI mice. Analysis of the action potential and low-threshold calcium spike (LTCS) properties revealed that, contrary to that observed in WT D-hair neurons, a low concentration of zinc and nickel is unable to modulate (1) the rheobase threshold current, (2) the afterdepolarization amplitude, (3) the threshold potential necessary to trigger an LTCS or (4) the LTCS amplitude in D-hair neurons from KI mice. Together, our data demonstrate that this H191-dependent metal/redox regulation of Cav3.2 channels can tune neuronal excitability. This study validates the use of this Cav3.2-H191Q mouse model for further investigations of the physiological roles thought to rely on this Cav3.2 modulation.
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Affiliation(s)
- Tiphaine Voisin
- Centre National pour la Recherche Scientifique UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Université de Montpellier, Montpellier, F-34094, France.,Institut National de la Santé et de la Recherche Médicale, U 1191, Montpellier, F-34094, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, F-34094, France
| | - Emmanuel Bourinet
- Centre National pour la Recherche Scientifique UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Université de Montpellier, Montpellier, F-34094, France.,Institut National de la Santé et de la Recherche Médicale, U 1191, Montpellier, F-34094, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, F-34094, France
| | - Philippe Lory
- Centre National pour la Recherche Scientifique UMR 5203, Département de Physiologie, Institut de Génomique Fonctionnelle, Université de Montpellier, Montpellier, F-34094, France.,Institut National de la Santé et de la Recherche Médicale, U 1191, Montpellier, F-34094, France.,LabEx 'Ion Channel Science and Therapeutics', Montpellier, F-34094, France
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55
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Tamano H, Takeda A. Is interaction of amyloid β-peptides with metals involved in cognitive activity? Metallomics 2016; 7:1205-12. [PMID: 25959547 DOI: 10.1039/c5mt00076a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Metal ions, i.e., Zn(2+) and Cu(2+), are released from neuron terminals in the hippocampus, which plays important roles in spatial and declarative memory, and may serve as a signal factor. Synaptic homeostasis of metal ions is critical for cognitive activity in the hippocampus. Amyloid-β (Aβ) is a causative candidate for the pathogenesis of Alzheimer's disease (AD) and Aβ-induced synapse dysfunction is easy to emerge along with normal aging and leads to the cognitive decline and memory loss in the pre-dementia stage of AD. Because Aβ interacts with Zn(2+) and Cu(2+), it is likely that these metal ions are involved in the Aβ-induced modification of the synaptic function. There is evidence to indicate that the inhibition of the interaction of Aβ with Zn(2+) and Cu(2+) may ameliorate the pathophysiology of AD. Interaction of extracellular Zn(2+) with Aβ in the hippocampus is involved in transiently Aβ-induced cognition deficits, while the interaction of extracellular Cu(2+) reduces bioavailability of intracellular Cu(2+), followed by an increase in oxidative stress, which may lead to cognitive deficits. It is likely that Zn(2+) and Cu(2+) play as a key-mediating factor in pathophysiology of the synaptic dysfunction in which Aβ is involved. Based on the idea that understating Aβ-induced changes in synaptic plasticity is important to prevent AD, the present paper summarizes the interaction of Aβ with metal ions in cognition.
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Affiliation(s)
- Haruna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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56
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Trattnig SM, Gasiorek A, Deeb TZ, Ortiz EJC, Moss SJ, Jensen AA, Davies PA. Copper and protons directly activate the zinc-activated channel. Biochem Pharmacol 2016; 103:109-17. [PMID: 26872532 PMCID: PMC5119521 DOI: 10.1016/j.bcp.2016.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/08/2016] [Indexed: 12/11/2022]
Abstract
The zinc-activated channel (ZAC) is a cationic ion channel belonging to the superfamily of Cys-loop receptors, which consists of pentameric ligand-gated ion channels. ZAC is the least understood member of this family so in the present study we sought to characterize the properties of this channel further. We demonstrate that not only zinc (Zn(2+)) but also copper (Cu(2+)) and protons (H(+)) are agonists of ZAC, displaying potencies and efficacies in the rank orders of H(+)>Cu(2+)>Zn(2+) and H(+)>Zn(2+)>Cu(2+), respectively. The responses elicited by Zn(2+), Cu(2+) and H(+) through ZAC are all characterized by low degrees of desensitization. In contrast, currents evoked by high concentrations of the three agonists comprise distinctly different activation and decay components, with transitions to and from an open state being significantly faster for H(+) than for the two metal ions. The permeabilities of ZAC for Na(+) and K(+) relative to Cs(+) are indistinguishable, whereas replacing all of extracellular Na(+) and K(+) with the divalent cations Ca(2+) or Mg(2+) results in complete elimination of Zn(2+)-activated currents at both negative and positive holding potentials. This indicates that ZAC is non-selectively permeable to monovalent cations, whereas Ca(2+) and Mg(2+) inhibit the channel. In conclusion, this is the first report of a Cys-loop receptor being gated by Zn(2+), Cu(2+) and H(+). ZAC could be an important mediator of some of the wide range of physiological functions regulated by or involving Zn(2+), Cu(2+) and H(+).
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Affiliation(s)
- Sarah M Trattnig
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
| | - Agnes Gasiorek
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA.
| | | | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
| | - Paul A Davies
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA.
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57
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Talat MA, Ahmed A, Mohammed L. Serum levels of zinc and copper in epileptic children during long-term therapy with anticonvulsants. ACTA ACUST UNITED AC 2016; 20:341-5. [PMID: 26492112 PMCID: PMC4727616 DOI: 10.17712/nsj.2015.4.20150336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Objective: To evaluate the serum levels of zinc and copper in epileptic children during the long-term treatment of anticonvulsant drugs and correlate this with healthy subjects. Methods: A hospital-based group matched case-control study was conducted in the Department of Pediatrics, Faculty of Medicine, Zagazig University, Zagazig, Egypt between November 2013 and October 2014. Ninety patients aged 7.1±3.6 years were diagnosed with epilepsy by a neurologist. The control group was selected from healthy individuals and matched to the case group. Serum zinc and copper were measured by the calorimetric method using a colorimetric method kit. Results: The mean zinc level was 60.1±22.6 ug/dl in the cases, and 102.1±18 ug/dl in the controls (p<0.001). The mean copper level was 180.1±32.4 ug/dl in cases compared with 114.5±18.5 ug/dl in controls (p<0.001). Conclusion: Serum zinc levels in epileptic children under drug treatment are lower compared with healthy children. Also, serum copper levels in these patients are significantly higher than in healthy people. No significant difference in the levels of serum copper and zinc was observed in using one drug or multiple drugs in the treatment of epileptic patients.
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Affiliation(s)
- Mohamed A Talat
- Department of Pediatrics, Faculty of Medicine, Zagazig University, Zagazig, Egypt. E-mail:
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58
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Cao S, Jin Q, Geng L, Mu L, Dong S. A “turn-on” fluorescent probe for the detection of Cu2+ in living cells based on a signaling mechanism of NN isomerization. NEW J CHEM 2016. [DOI: 10.1039/c5nj03649f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A “turn-on” probe A based on coumarin with a mechanism of NN isomerization was developed for detecting Cu2+ in living cells.
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Affiliation(s)
- Shuo Cao
- Institute of Biochemistry and Molecular Biology
- School of Life Sciences
- Lanzhou University
- Lanzhou 730000
- China
| | - Qiaoying Jin
- Institute of Biochemistry and Molecular Biology
- School of Life Sciences
- Lanzhou University
- Lanzhou 730000
- China
| | - Lin Geng
- Institute of Biochemistry and Molecular Biology
- School of Life Sciences
- Lanzhou University
- Lanzhou 730000
- China
| | - Lingyun Mu
- Institute of Biochemistry and Molecular Biology
- School of Life Sciences
- Lanzhou University
- Lanzhou 730000
- China
| | - Shouliang Dong
- Institute of Biochemistry and Molecular Biology
- School of Life Sciences
- Lanzhou University
- Lanzhou 730000
- China
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59
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Li W, Gan X, Liu D, Tian X, Yu J, Tian Y, Wu J, Zhou H. High contrast off–on fluorescence photo-switching via copper ion recognition, trans–cis isomerization and ring closure of a thiosemicarbazide Schiff base. RSC Adv 2016. [DOI: 10.1039/c6ra05699g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Two independently addressable photochromic systems based on distinct mechanisms and selective recognition for Cu2+were investigated in detail.
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Affiliation(s)
- Wei Li
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
| | - Xiaoping Gan
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
- School of Science
| | - Dan Liu
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
| | - Xiaohe Tian
- Center of Stem Cell Research and Transformation Medicine
- Anhui University
- Hefei 230601
- P. R. China
| | - Jianhua Yu
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
| | - Yupeng Tian
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
| | - Jieying Wu
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
| | - Hongping Zhou
- College of Chemistry and Chemical Engineering
- Anhui University and Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province
- Hefei 230601
- P. R. China
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60
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Saghazadeh A, Mahmoudi M, Meysamie A, Gharedaghi M, Zamponi GW, Rezaei N. Possible role of trace elements in epilepsy and febrile seizures: a meta-analysis. Nutr Rev 2015; 73:760-79. [DOI: 10.1093/nutrit/nuv026] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Slepchenko KG, Daniels NA, Guo A, Li YV. Autocrine effect of Zn²⁺ on the glucose-stimulated insulin secretion. Endocrine 2015; 50:110-22. [PMID: 25771886 DOI: 10.1007/s12020-015-0568-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 03/02/2015] [Indexed: 12/30/2022]
Abstract
It is well known that zinc (Zn(2+)) is required for the process of insulin biosynthesis and the maturation of insulin secretory granules in pancreatic beta (β)-cells, and that changes in Zn(2+) levels in the pancreas have been found to be associated with diabetes. Glucose-stimulation causes a rapid co-secretion of Zn(2+) and insulin with similar kinetics. However, we do not know whether Zn(2+) regulates insulin availability and secretion. Here we investigated the effect of Zn(2+) on glucose-stimulated insulin secretion (GSIS) in isolated mouse pancreatic islets. Whereas Zn(2+) alone (control) had no effect on the basal secretion of insulin, it significantly inhibited GSIS. The application of CaEDTA, by removing the secreted Zn(2+) from the extracellular milieu of the islets, resulted in significantly increased GSIS, suggesting an overall inhibitory role of secreted Zn(2+) on GSIS. The inhibitory action of Zn(2+) was mostly mediated through the activities of KATP/Ca(2+) channels. Furthermore, during brief paired-pulse glucose-stimulated Zn(2+) secretion (GSZS), Zn(2+) secretion following the second pulse was significantly attenuated, probably by the secreted endogenous Zn(2+) after the first pulse. Such an inhibition on Zn(2+) secretion following the second pulse was completely reversed by Zn(2+) chelation, suggesting a negative feedback mechanism, in which the initial glucose-stimulated Zn(2+) release inhibits subsequent Zn(2+) secretion, subsequently inhibiting insulin co-secretion as well. Taken together, these data suggest a negative feedback mechanism on GSZS and GSIS by Zn(2+) secreted from β-cells, and the co-secreted Zn(2+) may act as an autocrine inhibitory modulator.
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Affiliation(s)
- Kira G Slepchenko
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
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62
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Suzuki M, Fujise Y, Tsuchiya Y, Tamano H, Takeda A. Excess influx of Zn(2+) into dentate granule cells affects object recognition memory via attenuated LTP. Neurochem Int 2015; 87:60-5. [PMID: 26044210 DOI: 10.1016/j.neuint.2015.05.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/21/2015] [Accepted: 05/26/2015] [Indexed: 10/23/2022]
Abstract
The influx of extracellular Zn(2+) into dentate granule cells is nonessential for dentate gyrus long-term potentiation (LTP) and the physiological significance of extracellular Zn(2+) dynamics is unknown in the dentate gyrus. Excess increase in extracellular Zn(2+) in the hippocampal CA1, which is induced with excitation of zincergic neurons, induces memory deficit via excess influx of Zn(2+) into CA1 pyramidal cells. In the present study, it was examined whether extracellular Zn(2+) induces object recognition memory deficit via excess influx of Zn(2+) into dentate granule cells. KCl (100 mM, 2 µl) was locally injected into the dentate gyrus. The increase in intracellular Zn(2+) in dentate granule cells induced with high K(+) was blocked by co-injection of CaEDTA and CNQX, an extracellular Zn(2+) chelator and an AMPA receptor antagonist, respectively, suggesting that high K(+) increases the influx of Zn(2+) into dentate granule cells via AMPA receptor activation. Dentate gyrus LTP induction was attenuated 1 h after KCl injection into the dentate gyrus and also attenuated when KCl was injected 5 min after the induction. Memory deficit was induced when training of object recognition test was performed 1 h after KCl injection into the dentate gyrus and also induced when KCl was injected 5 min after the training. High K(+)-induced impairments of LTP and memory were rescued by co-injection of CaEDTA. These results indicate that excess influx of Zn(2+) into dentate granule cells via AMPA receptor activation affects object recognition memory via attenuated LTP induction. Even in the dentate gyrus where is scarcely innervated by zincergic neurons, it is likely that extracellular Zn(2+) homeostasis is strictly regulated for cognition.
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Affiliation(s)
- Miki Suzuki
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yuki Fujise
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yuka Tsuchiya
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Haruna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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63
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Diethyldithiocarbamate-mediated zinc ion chelation reveals role of Cav2.3 channels in glucagon secretion. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:953-64. [DOI: 10.1016/j.bbamcr.2015.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 12/28/2014] [Accepted: 01/03/2015] [Indexed: 12/13/2022]
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Voltage-gated calcium channels: Determinants of channel function and modulation by inorganic cations. Prog Neurobiol 2015; 129:1-36. [PMID: 25817891 DOI: 10.1016/j.pneurobio.2014.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 12/15/2014] [Accepted: 12/27/2014] [Indexed: 11/20/2022]
Abstract
Voltage-gated calcium channels (VGCCs) represent a key link between electrical signals and non-electrical processes, such as contraction, secretion and transcription. Evolved to achieve high rates of Ca(2+)-selective flux, they possess an elaborate mechanism for selection of Ca(2+) over foreign ions. It has been convincingly linked to competitive binding in the pore, but the fundamental question of how this is reconcilable with high rates of Ca(2+) transfer remains unanswered. By virtue of their similarity to Ca(2+), polyvalent cations can interfere with the function of VGCCs and have proven instrumental in probing the mechanisms underlying selective permeation. Recent emergence of crystallographic data on a set of Ca(2+)-selective model channels provides a structural framework for permeation in VGCCs, and warrants a reconsideration of their diverse modulation by polyvalent cations, which can be roughly separated into three general mechanisms: (I) long-range interactions with charged regions on the surface, affecting the local potential sensed by the channel or influencing voltage-sensor movement by repulsive forces (electrostatic effects), (II) short-range interactions with sites in the ion-conducting pathway, leading to physical obstruction of the channel (pore block), and in some cases (III) short-range interactions with extracellular binding sites, leading to non-electrostatic modifications of channel gating (allosteric effects). These effects, together with the underlying molecular modifications, provide valuable insights into the function of VGCCs, and have important physiological and pathophysiological implications. Allosteric suppression of some of the pore-forming Cavα1-subunits (Cav2.3, Cav3.2) by Zn(2+) and Cu(2+) may play a major role for the regulation of excitability by endogenous transition metal ions. The fact that these ions can often traverse VGCCs can contribute to the detrimental intracellular accumulation of metal ions following excessive release of endogenous Cu(2+) and Zn(2+) or exposure to non-physiological toxic metal ions.
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65
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Mahapatra AK, Mondal S, Manna SK, Maiti K, Maji R, Uddin MR, Mandal S, Sarkar D, Mondal TK, Maiti DK. A new selective chromogenic and turn-on fluorogenic probe for copper(ii) in solution and vero cells: recognition of sulphide by [CuL]. Dalton Trans 2015; 44:6490-501. [DOI: 10.1039/c4dt03969f] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A new coumarin-appended thioimidazole-linked imine conjugate,viz.Lhas been synthesized and characterized for a selectiveturn-onfluorescence chemosensor for Cu2+.
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Affiliation(s)
- Ajit Kumar Mahapatra
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah – 711103
- India
| | - Sanchita Mondal
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah – 711103
- India
| | - Saikat Kumar Manna
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah – 711103
- India
| | - Kalipada Maiti
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah – 711103
- India
| | - Rajkishor Maji
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah – 711103
- India
| | - Md. Raihan Uddin
- Department of Microbiology
- Ballygunge Science College
- Kolkata-700019
- India
| | - Sukhendu Mandal
- Department of Microbiology
- Ballygunge Science College
- Kolkata-700019
- India
| | - Deblina Sarkar
- Department of Chemistry
- Jadavpur University
- Kolkata-700032
- India
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66
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Ali TY, Broughton Pipkin F, Khan RN. The effect of pH and ion channel modulators on human placental arteries. PLoS One 2014; 9:e114405. [PMID: 25490401 PMCID: PMC4260857 DOI: 10.1371/journal.pone.0114405] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 11/06/2014] [Indexed: 12/31/2022] Open
Abstract
Chorionic plate arteries (CPA) are located at the maternofetal interface where they are able to respond to local metabolic changes. Unlike many other types of vasculature, the placenta lacks nervous control and requires autoregulation for controlling blood flow. The placental circulation, which is of low-resistance, may become hypoxic easily leading to fetal acidosis and fetal distress however the role of the ion channels in these circumstances is not well-understood. Active potassium channel conductances that are subject to local physicochemical modulation may serve as pathways through which such signals are transduced. The aim of this study was to investigate the modulation of CPA by pH and the channels implicated in these responses using wire myography. CPA were isolated from healthy placentae and pre-contracted with U46619 before testing the effects of extracellular pH using 1 M lactic acid over the pH range 7.4 - 6.4 in the presence of a variety of ion channel modulators. A change from pH 7.4 to 7.2 produced a 29±3% (n = 9) relaxation of CPA which increased to 61±4% at the lowest pH of 6.4. In vessels isolated from placentae of women with pre-eclampsia (n = 6), pH responses were attenuated. L-methionine increased the relaxation to 67±7% (n = 6; p<0.001) at pH 6.4. Similarly the TASK 1/3 blocker zinc chloride (1 mM) gave a maximum relaxation of 72±5% (n = 8; p<0.01) which compared with the relaxation produced by the TREK-1 opener riluzole (75±5%; n = 6). Several other modulators induced no significant changes in vascular responses. Our study confirmed expression of several ion channel subtypes in CPA with our results indicating that extracellular pH within the physiological range has an important role in controlling vasodilatation in the human term placenta.
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Affiliation(s)
- Tayyba Y Ali
- Division of Medical Sciences & Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, United Kingdom
| | - Fiona Broughton Pipkin
- Division of Medical Sciences & Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, United Kingdom
| | - Raheela N Khan
- Division of Medical Sciences & Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, United Kingdom
- * E-mail:
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67
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Castro PA, Ramirez A, Sepúlveda FJ, Peters C, Fierro H, Waldron J, Luza S, Fuentealba J, Muñoz FJ, De Ferrari GV, Bush AI, Aguayo LG, Opazo CM. Copper-uptake is critical for the down regulation of synapsin and dynamin induced by neocuproine: modulation of synaptic activity in hippocampal neurons. Front Aging Neurosci 2014; 6:319. [PMID: 25520655 PMCID: PMC4253966 DOI: 10.3389/fnagi.2014.00319] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/30/2014] [Indexed: 01/08/2023] Open
Abstract
Extracellular and intracellular copper and zinc regulate synaptic activity and plasticity, which may impact brain functionality and human behavior. We have found that a metal coordinating molecule, Neocuproine, transiently increases free intracellular copper and zinc levels (i.e., min) in hippocampal neurons as monitored by Phen Green and FluoZin-3 fluorescence, respectively. The changes in free intracellular zinc induced by Neocuproine were abolished by the presence of a non-permeant copper chelator, Bathocuproine (BC), indicating that copper influx is needed for the action of Neocuproine on intracellular Zn levels. Moreover, Neocuproine decreased the mRNA levels of Synapsin and Dynamin, and did not affect the expression of Bassoon, tubulin or superoxide dismutase (SOD). Western blot analysis showed that protein levels of synapsin and dynamin were also down regulated in the presence of Neocuproine and that these changes were accompanied by a decrease in calcium transients and neuronal activity. Furthermore, Neocuproine decreased the number of active neurons, effect that was blocked by the presence of BC, indicating that copper influx is needed for the action of Neocuproine. We finally show that Neocuproine blocks the epileptiform-like activity induced by bicuculline in hippocampal neurons. Collectively, our data indicates that presynaptic protein configuration and function of primary hippocampal neurons is sensitive to transient changes in transition metal homeostasis. Therefore, small molecules able to coordinate transition metals and penetrate the blood-brain barrier might modify neurotransmission at the Central Nervous System (CNS). This might be useful to establish therapeutic approaches to control the neuronal hyperexcitabiltity observed in brain conditions that are associated to copper dyshomeotasis such as Alzheimer’s and Menkes diseases. Our work also opens a new avenue to find novel and effective antiepilepsy drugs based in metal coordinating molecules.
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Affiliation(s)
- Patricio A Castro
- Department of Physiology and Membrane Biology, Shriners Hospital for Children Northern California, University of California at Davis School of Medicine California, USA
| | - Alejandra Ramirez
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile ; Oxidation Biology Laboratory, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, Melbourne, Victoria, Australia
| | - Fernando J Sepúlveda
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Christian Peters
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Humberto Fierro
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Javier Waldron
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Sandra Luza
- Oxidation Biology Laboratory, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, Melbourne, Victoria, Australia
| | - Jorge Fuentealba
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Francisco J Muñoz
- Laboratory of Molecular Physiology and Channelopathies, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra Barcelona, Spain
| | - Giancarlo V De Ferrari
- Center for Biomedical Research and FONDAP Center for Genome Regulation, Universidad Andrés Bello Santiago, Chile
| | - Ashley I Bush
- Oxidation Biology Laboratory, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, Melbourne, Victoria, Australia
| | - Luis G Aguayo
- Laboratorio de Neurofisiología, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Carlos M Opazo
- Oxidation Biology Laboratory, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, Melbourne, Victoria, Australia
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68
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Safwen K, Selima S, Mohamed E, Ferid L, Pascal C, Mohamed A, Ezzedine A, Meherzia M. Protective effect of grape seed and skin extract on cerebral ischemia in rat: implication of transition metals. Int J Stroke 2014; 10:415-24. [PMID: 25365917 DOI: 10.1111/ijs.12391] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 08/19/2014] [Indexed: 11/29/2022]
Abstract
Ischemic stroke is a leading cause of long lasting disability in humans and oxidative stress an important underlying cause. The present study aims to determine the effect of short term (seven-days) administration of high dosage grape seed and skin extract (GSSE 2.5 g/kg) on ischemia/reperfusion (I/R) injury in a rat model of global ischemia. Ischemia was induced by occlusion of the common carotid arteries for 30 min followed by one-hour reperfusion on control or GSSE treated animals. I/R induced a drastic oxidative stress characterized by high lipid and protein oxidation, a drop in antioxidant enzyme defenses, disturbed transition metals as free iron overload and depletion of copper, zinc and manganese as well as of associated brain enzyme activities as glutamine synthetase and lactate dehydrogenase. I/R also induced NO and calcium disruption and an increase in calpain activity, a calcium-sensitive cysteine protease. Interestingly, almost all I/R-induced disturbances were prevented by GSSE pretreatment as oxidative stress, transition metals associated enzyme activities, brain damage size and histology. Owing to its antioxidant potential, high dosage GSSE protected efficiently the brain against ischemic stroke and should be translated to humans.
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Affiliation(s)
- Kadri Safwen
- Bioactive Substance Laboratory, Biotechnology Centre, Hammam-Lif, Tunis
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69
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New family of fluorogenic azacrown probes with identical cavity size but different electronic environment outside the macrocycle: effects on sensitivity of Cu2+ detection. J INCL PHENOM MACRO 2014. [DOI: 10.1007/s10847-014-0453-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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70
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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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71
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Todorovic SM, Jevtovic-Todorovic V. Redox regulation of neuronal voltage-gated calcium channels. Antioxid Redox Signal 2014; 21:880-91. [PMID: 24161125 PMCID: PMC4116091 DOI: 10.1089/ars.2013.5610] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
SIGNIFICANCE Voltage-gated calcium channels are ubiquitously expressed in neurons and are key regulators of cellular excitability and synaptic transmitter release. There is accumulating evidence that multiple subtypes of voltage-gated calcium channels may be regulated by oxidation and reduction. However, the redox mechanisms involved in the regulation of channel function are not well understood. RECENT ADVANCES Several studies have established that both T-type and high-voltage-activated subtypes of voltage-gated calcium channel can be redox-regulated. This article reviews different mechanisms that can be involved in redox regulation of calcium channel function and their implication in neuronal function, particularly in pain pathways and thalamic oscillation. CRITICAL ISSUES A current critical issue in the field is to decipher precise mechanisms of calcium channel modulation via redox reactions. In this review we discuss covalent post-translational modification via oxidation of cysteine molecules and chelation of trace metals, and reactions involving nitric oxide-related molecules and free radicals. Improved understanding of the roles of redox-based reactions in regulation of voltage-gated calcium channels may lead to improved understanding of novel redox mechanisms in physiological and pathological processes. FUTURE DIRECTIONS Identification of redox mechanisms and sites on voltage-gated calcium channel may allow development of novel and specific ion channel therapies for unmet medical needs. Thus, it may be possible to regulate the redox state of these channels in treatment of pathological process such as epilepsy and neuropathic pain.
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Affiliation(s)
- Slobodan M Todorovic
- 1 Department of Anesthesiology, University of Virginia School of Medicine , Charlottesville, Virginia
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72
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Vysotskaya ZV, Moss CR, Gu Q. Differential regulation of ASICs and TRPV1 by zinc in rat bronchopulmonary sensory neurons. Lung 2014; 192:927-34. [PMID: 25108402 DOI: 10.1007/s00408-014-9634-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/25/2014] [Indexed: 01/01/2023]
Abstract
PURPOSE Zinc has been known to act as a signaling molecule that regulates a variety of neuronal functions. In this study, we aimed to study the effect of zinc on two populations of acid-sensitive ion channels, acid-sensing ion channels (ASICs), and transient receptor potential vanilloid receptor-1 (TRPV1), in vagal bronchopulmonary sensory neurons. METHODS Rat vagal sensory neurons innervating lungs and airways were retrogradely labeled with a fluorescent tracer. Whole-cell perforated patch-clamp recordings were carried out in primarily cultured bronchopulmonary sensory neurons. The acid-evoked ASIC and TRPV1 currents were measured and compared between before and after the zinc pretreatment. RESULTS ASIC currents were induced by a pH drop from 7.4 to 6.8 or 6.5 in the presence of capsazepine (10 µM), a specific TRPV1 antagonist. Pretreatment with zinc (50 or 300 µM, 2 min) displayed different effects on the two distinct phenotypes of ASIC currents: a marked potentiation on ASIC channels with fast kinetics of activation and inactivation or no significant effect on ASIC currents with slow activation and inactivation. On the other hand, pretreatment with zinc significantly inhibited the acid (pH 5.5 or 5.3)-induced TRPV1 currents. The inhibition was abolished by intracellular chelation of zinc by TPEN (25 µM), indicating that intracellular accumulation of zinc was likely required for its inhibitory effect on TRPV1 channels. CONCLUSIONS Our study showed that zinc differentially regulates the activities of ASICs and TRPV1 channels in rat vagal bronchopulmonary sensory neurons.
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Affiliation(s)
- Zhanna V Vysotskaya
- Division of Basic Medical Sciences, Mercer University School of Medicine, 1550 College Street, Macon, GA, 31207, USA
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73
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Moraes-Silva L, Siqueira LF, Oliveira VA, Oliveira CS, Ineu RP, Pedroso TF, Fonseca MM, Pereira ME. Preventive Effect of CuCl2on Behavioral Alterations and Mercury Accumulation in Central Nervous System Induced by HgCl2in Newborn Rats. J Biochem Mol Toxicol 2014; 28:328-35. [DOI: 10.1002/jbt.21569] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/31/2014] [Accepted: 04/07/2014] [Indexed: 12/26/2022]
Affiliation(s)
- L. Moraes-Silva
- Programa de Pós-Graduação em Bioquímica Toxicológica, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - L. F. Siqueira
- Departamento de Bioquímica e Biologia Molecular, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - V. A. Oliveira
- Programa de Pós-Graduação em Bioquímica Toxicológica, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - C. S. Oliveira
- Programa de Pós-Graduação em Bioquímica Toxicológica, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - R. P. Ineu
- Programa de Pós-Graduação em Bioquímica Toxicológica, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - T. F. Pedroso
- Departamento de Bioquímica e Biologia Molecular, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - M. M. Fonseca
- Departamento de Bioquímica e Biologia Molecular, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
| | - M. E. Pereira
- Programa de Pós-Graduação em Bioquímica Toxicológica, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
- Departamento de Bioquímica e Biologia Molecular, CCNE; Universidade Federal de Santa Maria; Santa Maria 97105-900 RS Brazil
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74
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Oda Y, Kodama S, Tsuchiya S, Inoue M, Miyakawa H. Intracellular calcium elevation during plateau potentials mediated by extrasynaptic NMDA receptor activation in rat hippocampal CA1 pyramidal neurons is primarily due to calcium entry through voltage-gated calcium channels. Eur J Neurosci 2014; 39:1613-23. [DOI: 10.1111/ejn.12555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 02/04/2014] [Accepted: 02/11/2014] [Indexed: 12/21/2022]
Affiliation(s)
- Yoshiaki Oda
- Laboratory of Cellular Neurobiology; School of Life Sciences; Tokyo University of Pharmacy and Life Sciences; Hachioji Tokyo 192-0392 Japan
| | - Satoshi Kodama
- Laboratory of Cellular Neurobiology; School of Life Sciences; Tokyo University of Pharmacy and Life Sciences; Hachioji Tokyo 192-0392 Japan
| | - Sadahiro Tsuchiya
- Laboratory of Cellular Neurobiology; School of Life Sciences; Tokyo University of Pharmacy and Life Sciences; Hachioji Tokyo 192-0392 Japan
| | - Masashi Inoue
- Laboratory of Cellular Neurobiology; School of Life Sciences; Tokyo University of Pharmacy and Life Sciences; Hachioji Tokyo 192-0392 Japan
| | - Hiroyoshi Miyakawa
- Laboratory of Cellular Neurobiology; School of Life Sciences; Tokyo University of Pharmacy and Life Sciences; Hachioji Tokyo 192-0392 Japan
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75
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New colorimetric chemosensor based on rhodamine hydrazide to detect Cu2+ ions by naked eye. RESEARCH ON CHEMICAL INTERMEDIATES 2014. [DOI: 10.1007/s11164-014-1588-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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76
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Abstract
Zinc (Zn2+) is an essential element crucial for growth and development, and also plays a role in cell signaling for cellular processes like cell division and apoptosis. In the mammalian pancreas, Zn2+ is essential for the correct processing, storage, secretion, and action of insulin in beta (β)-cells. Insulin is stored inside secretory vesicles or granules, where two Zn2+ ions coordinate six insulin monomers to form the hexameric-structure on which maturated insulin crystals are based. The total Zn2+ content of the mammalian pancreas is among the highest in the body, and Zn2+ concentration reach millimolar levels in the interior of the dense-core granule. Changes in Zn2+ levels in the pancreas have been found to be associated with diabetes. Hence, the relationship between co-stored Zn2+ and insulin undoubtedly is critical to normal β-cell function. The advances in the field of Zn2+ biology over the last decade have facilitated our understanding of Zn2+ trafficking, its intracellular distribution and its storage. When exocytosis of insulin occurs, insulin granules fuse with the β-cell plasma membrane and release their contents, i.e., insulin as well as substantial amount of free Zn2+, into the extracellular space and the local circulation. Studies increasingly indicate that secreted Zn2+ has autocrine or paracrine signaling in β-cells or the neighboring cells. This review discusses the Zn2+ homeostasis in β-cells with emphasis on the potential signaling role of Zn2+ to islet biology.
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Affiliation(s)
- Yang V Li
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, 346 Irvine Hall, Athens, OH, 45701, USA,
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77
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Gaier ED, Rodriguiz RM, Zhou J, Ralle M, Wetsel WC, Eipper BA, Mains RE. In vivo and in vitro analyses of amygdalar function reveal a role for copper. J Neurophysiol 2014; 111:1927-39. [PMID: 24554785 DOI: 10.1152/jn.00631.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mice with a single copy of the peptide amidating monooxygenase (Pam) gene (PAM(+/-)) are impaired in contextual and cued fear conditioning. These abnormalities coincide with deficient long-term potentiation (LTP) at excitatory thalamic afferent synapses onto pyramidal neurons in the lateral amygdala. Slice recordings from PAM(+/-) mice identified an increase in GABAergic tone (Gaier ED, Rodriguiz RM, Ma XM, Sivaramakrishnan S, Bousquet-Moore D, Wetsel WC, Eipper BA, Mains RE. J Neurosci 30: 13656-13669, 2010). Biochemical data indicate a tissue-specific deficit in Cu content in the amygdala; amygdalar expression of Atox-1 and Atp7a, essential for transport of Cu into the secretory pathway, is reduced in PAM(+/-) mice. When PAM(+/-) mice were fed a diet supplemented with Cu, the impairments in fear conditioning were reversed, and LTP was normalized in amygdala slice recordings. A role for endogenous Cu in amygdalar LTP was established by the inhibitory effect of a brief incubation of wild-type slices with bathocuproine disulfonate, a highly selective, cell-impermeant Cu chelator. Interestingly, bath-applied CuSO₄ had no effect on excitatory currents but reversibly potentiated the disynaptic inhibitory current. Bath-applied CuSO₄ was sufficient to potentiate wild-type amygdala afferent synapses. The ability of dietary Cu to affect signaling in pathways that govern fear-based behaviors supports an essential physiological role for Cu in amygdalar function at both the synaptic and behavioral levels. This work is relevant to neurological and psychiatric disorders in which disturbed Cu homeostasis could contribute to altered synaptic transmission, including Wilson's, Menkes, Alzheimer's, and prion-related diseases.
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Affiliation(s)
- E D Gaier
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut
| | - R M Rodriguiz
- Department of Psychiatry and Behavioral Sciences, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, North Carolina
| | - J Zhou
- Department of Psychiatry and Behavioral Sciences, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, North Carolina
| | - M Ralle
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon
| | - W C Wetsel
- Department of Psychiatry and Behavioral Sciences, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, North Carolina; Department of Neurobiology, Duke University Medical Center, Durham, North Carolina; and Department of Cell Biology, Duke University Medical Center, Durham, North Carolina
| | - B A Eipper
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut
| | - R E Mains
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut;
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78
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Multiple effects of copper on NMDA receptor currents. Brain Res 2014; 1542:20-31. [DOI: 10.1016/j.brainres.2013.10.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/15/2013] [Accepted: 10/16/2013] [Indexed: 12/31/2022]
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79
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Ortiz FC, Vergara C, Alcayaga J. Micromolar copper modifies electrical properties and spontaneous discharges of nodose ganglion neurons in vitro. Biometals 2013; 27:45-52. [PMID: 24213945 DOI: 10.1007/s10534-013-9685-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 11/04/2013] [Indexed: 11/25/2022]
Abstract
Copper plays a key role in aerobic cell physiology mainly related to mitochondrial metabolism. This element is also present at higher than basal levels in some central nuclei and indeed, current evidence support copper's role as a neuromodulator in the central nervous system. More recent data indicate that copper may also affect peripheral neuronal activity, but so far, there are not detailed descriptions of what peripheral neuronal characteristics are targeted by copper. Here, we studied the effect of physiological concentration of CuCl2 (μM range) on the activity of peripheral neurons using a preparation of nodose ganglion in vitro. By mean of conventional intracellular recordings passive and active electrical membrane properties were studied. Extracellular copper modified (in a redox-independent manner) the resting membrane potential and the input resistance of the nodose ganglion neurons, increasing the excitability in most of the tested neurons. These results suggest that Cu(2+) modulates the activity of nodose ganglion neurons and support nodose ganglion in vitro preparation as a simple model to study the subcellular mechanisms involved in the Cu(2+) effects on neuron electrical properties.
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Affiliation(s)
- Fernando C Ortiz
- Laboratorio de Fisiología Celular, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile,
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80
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Ugarte M, Osborne NN, Brown LA, Bishop PN. Iron, zinc, and copper in retinal physiology and disease. Surv Ophthalmol 2013; 58:585-609. [DOI: 10.1016/j.survophthal.2012.12.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 12/09/2012] [Accepted: 12/11/2012] [Indexed: 12/26/2022]
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81
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Yamada Y, Prosser RA. Copper chelation and exogenous copper affect circadian clock phase resetting in the suprachiasmatic nucleus in vitro. Neuroscience 2013; 256:252-61. [PMID: 24161278 DOI: 10.1016/j.neuroscience.2013.10.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 10/14/2013] [Accepted: 10/14/2013] [Indexed: 10/26/2022]
Abstract
Light stimulates specialized retinal ganglion cells to release glutamate (Glu) onto circadian clock neurons of the suprachiasmatic nucleus (SCN). Glu resets the phase of the SCN circadian clock by activating N-methyl-d-aspartate receptors (NMDAR) causing either delays or advances in the clock phase, depending on early- or late-night stimulation, respectively. In addition, these Glu-induced phase shifts require tropomyosin receptor kinase B (TrkB) receptor activity. Previous studies show that copper (Cu) released at hippocampal synapses can inhibit NMDAR activity, and application of exogenous Cu likewise inhibits NMDAR activity. We investigated the effects of Cu in acute SCN brain slices prepared from C57BL/6Nhsd adult, male mice using treatments that decrease or increase available Cu levels in vitro and recorded neuronal activity on the following day. When bath-applied for 10 min at zeitgeber time (ZT) 16 (where ZT0=lights-on in the donor animal colony), the Cu-specific chelators tetrathiomolybdate (TTM) and bathocuproine disulfonate each induce ∼2.5-3-h phase delays in circadian neuronal activity rhythms, similarly to Glu-induced phase delays. Co-application of 10 μM CuCl2, but not 10 μM CoCl₂ blocks TTM-induced phase delays. Furthermore, TTM causes phase advances when applied at ZT23. At both application times, TTM-induced phase shifts are blocked by NMDA or TrkB receptor antagonists. Surprisingly, bath-application of 10 μM Cu alone also induces phase shifts in analogous experiments at ZT16 and ZT23. Inhibiting NMDAR does not block Cu-induced phase shifts. TrkB inhibition blocks Cu-induced phase delays but not phase advances. Thus, increasing and decreasing Cu availability appear to shift the SCN clock phase through different mechanisms, at least at the receptor level. We propose that Cu plays a role in the SCN circadian clock by modulating Glu signaling.
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Affiliation(s)
- Y Yamada
- University of Tennessee, Knoxville, Department of Biochemistry, Cellular and Molecular Biology, Knoxville, TN 37996, USA
| | - R A Prosser
- University of Tennessee, Knoxville, Department of Biochemistry, Cellular and Molecular Biology, Knoxville, TN 37996, USA.
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82
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Abstract
Inhibition of GABAA receptors by Cu(2+) has been appreciated for some time, but differences between synaptic and extrasynaptic GABAA receptors have not been explored. We show that Cu(2+) potently blocks steady-state GABA currents mediated by extrasynaptic δ subunit-containing GABAA receptors (δ-GABAARs) with an IC50 of 65 nM. This compares with an IC50 of 85 μM for synaptic γ subunit-containing GABAARs (γ-GABAARs). To test the significance of this subunit selectivity, we examined the blocking action of Cu(2+) on neurons of the mouse cerebellum and striatum, brain regions that are known to express both types of receptor. Cu(2+) was shown to significantly reduce tonic inhibition mediated by extrasynaptic δ-GABAARs with little action on phasic inhibition mediated by conventional synaptic γ-GABAARs. We speculate on the implications of these observations for conditions, such as Wilson's disease, that can involve raised Cu(2+) levels in the brain.
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83
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Gaier ED, Miller MB, Ralle M, Aryal D, Wetsel WC, Mains RE, Eipper BA. Peptidylglycine α-amidating monooxygenase heterozygosity alters brain copper handling with region specificity. J Neurochem 2013; 127:605-19. [PMID: 24032518 DOI: 10.1111/jnc.12438] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 12/19/2022]
Abstract
Copper (Cu), an essential trace element present throughout the mammalian nervous system, is crucial for normal synaptic function. Neuronal handling of Cu is poorly understood. We studied the localization and expression of Atp7a, the major intracellular Cu transporter in the brain, and its relation to peptidylglycine α-amidating monooxygenase (PAM), an essential cuproenzyme and regulator of Cu homeostasis in neuroendocrine cells. Based on biochemical fractionation and immunostaining of dissociated neurons, Atp7a was enriched in post-synaptic vesicular fractions. Cu followed a similar pattern, with ~ 20% of total Cu in synaptosomes. A mouse model heterozygous for the Pam gene (PAM+/−) was selectively Cu deficient in the amygdala. As in cortex and hippocampus, Atp7a and PAM expression overlap in the amygdala, with highest expression in interneurons. Messenger RNA levels of Atox-1 and Atp7a, which deliver Cu to the secretory pathway, were reduced in the amygdala but not in the hippocampus in PAM+/− mice, GABAB receptor mRNA levels were similarly affected. Consistent with Cu deficiency, dopamine β-monooxygenase function was impaired as evidenced by elevated dopamine metabolites in the amygdala, but not in the hippocampus, of PAM+/− mice. These alterations in Cu delivery to the secretory pathway in the PAM+/− amygdala may contribute to the physiological and behavioral deficits observed. Atp7a, a Cu-transporting P-type ATPase, is localized to the trans-Golgi network and to vesicles distributed throughout the dendritic arbor. Tissue-specific alterations in Atp7a expression were found in mice heterozygous for peptidylglycine α-amidating monooxygenase (PAM), an essential neuropeptide-synthesizing cuproenzyme. Atp7a and PAM are highly expressed in amygdalar interneurons. Reduced amygdalar expression of Atox-1 and Atp7a in PAM heterozygous mice may lead to reduced synaptic Cu levels, contributing to the behavioral and neurochemical alterations seen in these mice.
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Affiliation(s)
- Eric D Gaier
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut, USA
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84
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Affiliation(s)
- Erendra Manandhar
- Department of Chemistry and Biochemistry, Bobby Chain Technology Center (TEC), The University of Southern Mississippi, Rm 441A, 118 College Drive, Box #5043, Hattiesburg, MS 39406, USA
| | - Peter J. Cragg
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Karl J. Wallace
- Department of Chemistry and Biochemistry, Bobby Chain Technology Center (TEC), The University of Southern Mississippi, Rm 441A, 118 College Drive, Box #5043, Hattiesburg, MS 39406, USA
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85
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Kaźmierczak K, Malukiewicz G, Lesiewska-Junk H, Laudencka A, Szady-Grad M, Klawe J, Nowicki K. Blood plasma levels of microelements in patients with history of optic neuritis. Curr Eye Res 2013; 39:93-8. [PMID: 24083481 DOI: 10.3109/02713683.2013.833244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE To determine the concentration of microelements in the blood of patients with a history of retrobulbar optic neuritis (ON). MATERIALS AND METHODS We examined 36 patients (18-63 years of age) - 11 with demyelinating ON (Group 1) and 25 with isolated ON (Group 2) - all of whom had been treated for retrobulbar ON. The control group comprised 38 healthy volunteers. Using atomic absorption spectroscopy, blood levels of zinc (Zn), iron (Fe), copper (Cu) and cadmium (Cd) were evaluated. RESULTS Compared with the control group, concentrations of Cd were elevated in Groups 1 and 2 (p = 0.003 and p = 0.003, respectively); Group 1 had higher levels of Cu (p = 0.02). Patients from both groups had significantly lower levels of Fe (p = 0.0003) compared with controls. No difference in the concentration of any of the microelements was found between Groups 1 and 2. CONCLUSION Disturbances in Cd, Cu and Fe homeostasis may be associated with the inflammatory process of ON.
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86
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Uchida K, Tominaga M. Extracellular zinc ion regulates transient receptor potential melastatin 5 (TRPM5) channel activation through its interaction with a pore loop domain. J Biol Chem 2013; 288:25950-25955. [PMID: 23884414 DOI: 10.1074/jbc.m113.470138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transient receptor potential melastatin 5 (TRPM5) channel is a monovalent cation channel activated by intracellular Ca(2+). Expression of this channel is restricted to taste cells, the pancreas and brainstem, and is thought to be involved in controlling membrane potentials. Its endogenous ligands are not well characterized. Here, we show that extracellular application of Zn(2+) inhibits TRPM5 activity. In whole-cell patch-clamp recordings, extracellular application of ZnCl2 inhibited step-pulse-induced TRPM5 currents with 500 nM free intracellular Ca(2+) in a dose-dependent manner (IC50 = 4.3 μM at -80 mV). ZnSO4 also inhibited TRPM5 activity. Extracellular application of ZnCl2 inhibited TRPM5 activation at several temperatures. Furthermore, inhibition by 30 μM ZnCl2 was impaired in TRPM5 mutants in which His at 896, and Glu at 926 and/or Glu at 939 in the outer pore loop were replaced with Gln. From these results, we conclude that extracellular Zn(2+) inhibits TRPM5 channels, and the residues in the outer pore loop of TRPM5 are critically involved in the inhibition.
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Affiliation(s)
- Kunitoshi Uchida
- From the Division of Cell Signaling, National Institute for Physiological Sciences (Okazaki Institutes for Integrative Bioscience), National Institutes of Natural Sciences, Okazaki 444-8787, Japan and; the Department of Physiological Sciences, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan.
| | - Makoto Tominaga
- From the Division of Cell Signaling, National Institute for Physiological Sciences (Okazaki Institutes for Integrative Bioscience), National Institutes of Natural Sciences, Okazaki 444-8787, Japan and; the Department of Physiological Sciences, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan.
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87
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Deepmala J, Deepak M, Srivastav S, Sangeeta S, Kumar SA, Kumar SS. Protective effect of combined therapy with dithiothreitol, zinc and selenium protects acute mercury induced oxidative injury in rats. J Trace Elem Med Biol 2013; 27:249-56. [PMID: 23428462 DOI: 10.1016/j.jtemb.2012.12.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 11/10/2012] [Accepted: 12/13/2012] [Indexed: 11/16/2022]
Abstract
The present study was undertaken to establish mode of action, comparative therapeutic efficacy and safety evaluation of dithiothreitol (DTT) supplemented with Zn and Se against dimethylmercury in rats. Adult male albino rats of Sprague-Dawley strain (150±10 g, n=6 per group) were exposed a bolus dose of dimethylmercury (10 mg/kg, p.o.) for once only followed by DTT (15.4 mg/kg, i.p.) along with the combination of antioxidants Zn and Se (2 mmol/kg and 0.5 mg/kg, p.o.) after 72 h of toxicant administration for three days. The results showed a significant (P≤0.05) increase in the activities of AST, ALT, alkaline phosphatase, lactate dehydrogenase, in serum after toxicant administration. This was accompanied by histopathological observations. A significant rise was observed in lipid peroxidation level and mercury ion concentration however reduced glutathione content decreased in liver, kidney and brain. A significant (P≤0.05) decrease in the activity of acetyl cholinesterase was also seen in different regions of brain. Combined treatment of DTT along with Zn and Se significantly (P≤0.05) recouped the alterations in the enzymatic activities of serum and reversed the tissue biochemical and histopathological changes of liver, kidney and brain. Our results demonstrate that combined treatment of thiol chelator (DTT) along with antioxidants (Zn and Se) plays an important role against dimethylmercury induced tissue damage and hepatic, nephro and neurotoxicity.
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Affiliation(s)
- Joshi Deepmala
- Reproductive Biology and Toxicology Laboratory, UNESCO Satellite Center of Trace Element Research & School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, India.
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88
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Marx G, Gilon C. The molecular basis of memory. Part 2: chemistry of the tripartite mechanism. ACS Chem Neurosci 2013; 4:983-93. [PMID: 23419130 DOI: 10.1021/cn300237r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
We propose a tripartite mechanism to describe the processing of cognitive information (cog-info), comprising the (1) neuron, (2) surrounding neural extracellular matrix (nECM), and (3) numerous "trace" metals distributed therein. The neuron is encased in a polyanionic nECM lattice doped with metals (>10), wherein it processes (computes) and stores cog-info. Each [nECM:metal] complex is the molecular correlate of a cognitive unit of information (cuinfo), similar to a computer "bit". These are induced/sensed by the neuron via surface iontophoretic and electroelastic (piezoelectric) sensors. The generic cuinfo are used by neurons to biochemically encode and store cog-info in a rapid, energy efficient, but computationally expansive manner. Here, we describe chemical reactions involved in various processes that underline the tripartite mechanism. In addition, we present novel iconographic representations of various types of cuinfo resulting from"tagging" and cross-linking reactions, essential for the indexing cuinfo for organized retrieval and storage of memory.
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Affiliation(s)
| | - Chaim Gilon
- Institute of Chemistry, Hebrew University, Jerusalem, Israel
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89
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Abstract
Hypoxia represents the lack of oxygen below the basic level, and the range of known channels related to hypoxia is continually increasing. Since abnormal hypoxia initiates pathological processes in numerous diseases via, to a great degree, producing acidic microenvironment, the significance of these channels in this environment has, until now, remained completely unknown. However, recent discovery of acid-sensing ion channels (ASICs) have enhanced our understanding of the hypoxic channelome. They belong to the degenerin/epithelial Na (+) channel family and function once extracellular pH decreases to a certain level. So does the ratiocination emerge that ASICs participate in many hypoxia-induced pathological processes, including pain, apoptosis, malignancy, which all appear to involve them. Since evidence suggests that activity of ASICs is altered under pathological hypoxia, future studies are needed to deeply explore the relationship between ASICs and hypoxia, which may provide a progressive understanding of hypoxic effects in cancer, arthritis, intervertebral disc degeneration, ischemic brain injury and so on.
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Affiliation(s)
- Guo Yingjun
- Department of Basic Medicine; Qilu Hospital; Shandong University; Ji'nan, Shandong Province, PR China
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90
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Amara S, Slama IB, Omri K, Ghoul JEL, Mir LEL, Rhouma KB, Abdelmelek H, Sakly M. Effects of nanoparticle zinc oxide on emotional behavior and trace elements homeostasis in rat brain. Toxicol Ind Health 2013; 31:1202-9. [DOI: 10.1177/0748233713491802] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Over recent years, nanotoxicology and the potential effects on human body have grown in significance, the potential influences of nanosized materials on the central nervous system have received more attention. The aim of this study was to determine whether zinc oxide (ZnO) nanoparticles (NPs) exposure cause alterations in emotional behavior and trace elements homeostasis in rat brain. Rats were treated by intraperitoneal injection of ZnO NPs (20–30 nm) at a dose of 25 mg/kg body weight. Sub-acute ZnO NPs treatment induced no significant increase in the zinc content in the homogenate brain. Statistically significant decreases in iron and calcium concentrations were found in rat brain tissue compared to control. However, sodium and potassium contents remained unchanged. Also, there were no significant changes in the body weight and the coefficient of brain. In the present study, the anxiety-related behavior was evaluated using the plus-maze test. ZnO NPs treatment modulates slightly the exploratory behaviors of rats. However, no significant differences were observed in the anxious index between ZnO NP-treated rats and the control group ( p > 0.05). Interestingly, our results demonstrated minimal effects of ZnO NPs on emotional behavior of animals, but there was a possible alteration in trace elements homeostasis in rat brain.
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Affiliation(s)
- Salem Amara
- Laboratoire de Physiologie Intégrée, Faculté des Sciences de Bizerte, Tunisia
| | - Imen Ben Slama
- Laboratoire de Physiologie Intégrée, Faculté des Sciences de Bizerte, Tunisia
| | - Karim Omri
- Laboratory of Physics of Materials and Nanomaterials Applied at Environment, College of Sciences in Gabes, Tunisia
| | - Jaber EL Ghoul
- Laboratory of Physics of Materials and Nanomaterials Applied at Environment, College of Sciences in Gabes, Tunisia
| | - Lassaad EL Mir
- Laboratory of Physics of Materials and Nanomaterials Applied at Environment, College of Sciences in Gabes, Tunisia
- Department of Physics, College of Sciences, Al Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Khemais Ben Rhouma
- Laboratoire de Physiologie Intégrée, Faculté des Sciences de Bizerte, Tunisia
| | - Hafedh Abdelmelek
- Laboratoire de Physiologie Intégrée, Faculté des Sciences de Bizerte, Tunisia
| | - Mohsen Sakly
- Laboratoire de Physiologie Intégrée, Faculté des Sciences de Bizerte, Tunisia
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91
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Checchetto V, Formentin E, Carraretto L, Segalla A, Giacometti GM, Szabo I, Bergantino E. Functional characterization and determination of the physiological role of a calcium-dependent potassium channel from cyanobacteria. PLANT PHYSIOLOGY 2013; 162:953-964. [PMID: 23640756 PMCID: PMC3668083 DOI: 10.1104/pp.113.215129] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/30/2013] [Indexed: 05/28/2023]
Abstract
Despite the important achievement of the high-resolution structures of several prokaryotic channels, current understanding of their physiological roles in bacteria themselves is still far from complete. We have identified a putative two transmembrane domain-containing channel, SynCaK, in the genome of the freshwater cyanobacterium Synechocystis sp. PCC 6803, a model photosynthetic organism. SynCaK displays significant sequence homology to MthK, a calcium-dependent potassium channel isolated from Methanobacterium thermoautotrophicum. Expression of SynCaK in fusion with enhanced GFP in mammalian Chinese hamster ovary cells' plasma membrane gave rise to a calcium-activated, potassium-selective activity in patch clamp experiments. In cyanobacteria, Western blotting of isolated membrane fractions located SynCaK mainly to the plasma membrane. To understand its physiological function, a SynCaK-deficient mutant of Synechocystis sp. PCC 6803, ΔSynCaK, has been obtained. Although the potassium content in the mutant organisms was comparable to that observed in the wild type, ΔSynCaK was characterized by a depolarized resting membrane potential, as determined by a potential-sensitive fluorescent probe. Growth of the mutant under various conditions revealed that lack of SynCaK does not impair growth under osmotic or salt stress and that SynCaK is not involved in the regulation of photosynthesis. Instead, its lack conferred an increased resistance to the heavy metal zinc, an environmental pollutant. A similar result was obtained using barium, a general potassium channel inhibitor that also caused depolarization. Our findings thus indicate that SynCaK is a functional channel and identify the physiological consequences of its deletion in cyanobacteria.
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92
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Bouron A, Oberwinkler J. Contribution of calcium-conducting channels to the transport of zinc ions. Pflugers Arch 2013; 466:381-7. [PMID: 23719866 DOI: 10.1007/s00424-013-1295-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/10/2013] [Accepted: 05/10/2013] [Indexed: 10/26/2022]
Abstract
Zinc (Zn) is a vital nutrient participating in a myriad of biological processes. The mechanisms controlling its transport through the plasma membrane are far from being completely understood. Two families of eukaryotic zinc transporters are known to date: the Zip (SLC39) and ZnT (SLC30) proteins. In addition, some types of plasmalemmal calcium (Ca)-conducting channels are implied in the cellular uptake of zinc. These ion channels are currently described as systems dedicated to the transport of Ca (and, to some extent, sodium (Na) ions). However, a growing body of evidence supports the view that some of them can also function as pathways for Zn transport. For instance, voltage-gated Ca channels and some types of glutamate-gated receptors have long been known to allow the entry of Zn. More recently, members of the TRP superfamily, another type of Ca-conducting channels, have been shown to permit the uptake of Zn into eukaryotic cells. The aim of this review article is to present the current knowledge supporting the notion that Ca-conducting channels take part in the plasmalemmal transport of Zn.
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93
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Schneider T, Dibué M, Hescheler J. How "Pharmacoresistant" is Cav2.3, the Major Component of Voltage-Gated R-type Ca2+ Channels? Pharmaceuticals (Basel) 2013; 6:759-76. [PMID: 24276260 PMCID: PMC3816731 DOI: 10.3390/ph6060759] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/26/2013] [Accepted: 05/06/2013] [Indexed: 12/04/2022] Open
Abstract
Membrane-bound voltage-gated Ca2+ channels (VGCCs) are targets for specific signaling complexes, which regulate important processes like gene expression, neurotransmitter release and neuronal excitability. It is becoming increasingly evident that the so called “resistant” (R-type) VGCC Cav2.3 is critical in several physiologic and pathophysiologic processes in the central nervous system, vascular system and in endocrine systems. However its eponymous attribute of pharmacologic inertness initially made in depth investigation of the channel difficult. Although the identification of SNX-482 as a fairly specific inhibitor of Cav2.3 in the nanomolar range has enabled insights into the channels properties, availability of other pharmacologic modulators of Cav2.3 with different chemical, physical and biological properties are of great importance for future investigations. Therefore the literature was screened systematically for molecules that modulate Cav2.3 VGCCs.
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Affiliation(s)
- Toni Schneider
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne D-50931, Germany; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (T.S.); (M.D.); Tel.: +49-221-478-69446 (T.S.); Fax: +49-221-478-6965 (T.S.)
| | - Maxine Dibué
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne D-50931, Germany; E-Mail:
- Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstraße 5, Duesseldorf D-40225, Germany & Center of Molecular Medicine, Cologne D-50931, Germany
- Authors to whom correspondence should be addressed; E-Mails: (T.S.); (M.D.); Tel.: +49-221-478-69446 (T.S.); Fax: +49-221-478-6965 (T.S.)
| | - Jürgen Hescheler
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne D-50931, Germany; E-Mail:
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94
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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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95
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McCracken LM, Blednov YA, Trudell JR, Benavidez JM, Betz H, Harris RA. Mutation of a zinc-binding residue in the glycine receptor α1 subunit changes ethanol sensitivity in vitro and alcohol consumption in vivo. J Pharmacol Exp Ther 2012; 344:489-500. [PMID: 23230213 DOI: 10.1124/jpet.112.197707] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ethanol is a widely used drug, yet an understanding of its sites and mechanisms of action remains incomplete. Among the protein targets of ethanol are glycine receptors (GlyRs), which are potentiated by millimolar concentrations of ethanol. In addition, zinc ions also modulate GlyR function, and recent evidence suggests that physiologic concentrations of zinc enhance ethanol potentiation of GlyRs. Here, we first built a homology model of a zinc-bound GlyR using the D80 position as a coordination site for a zinc ion. Next, we investigated in vitro the effects of zinc on ethanol action at recombinant wild-type (WT) and mutant α1 GlyRs containing the D80A substitution, which eliminates zinc potentiation. At D80A GlyRs, the effects of 50 and 200 mM ethanol were reduced as compared with WT receptors. Also, in contrast to what was seen with WT GlyRs, neither adding nor chelating zinc changed the magnitude of ethanol enhancement of mutant D80A receptors. Next, we evaluated the in vivo effects of the D80A substitution by using heterozygous Glra1(D80A) knock-in (KI) mice. The KI mice showed decreased ethanol consumption and preference, and they displayed increased startle responses compared with their WT littermates. Other behavioral tests, including ethanol-induced motor incoordination and strychnine-induced convulsions, revealed no differences between the KI and WT mice. Together, our findings indicate that zinc is critical in determining the effects of ethanol at GlyRs and suggest that zinc binding at the D80 position may be important for mediating some of the behavioral effects of ethanol action at GlyRs.
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Affiliation(s)
- Lindsay M McCracken
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
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96
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Madhupriya S, Elango KP. Highly selective colorimetric sensing of Cu(II) ions in aqueous solution via modulation of intramolecular charge transfer transition of aminonaphthoquinone chemosensor. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 97:100-4. [PMID: 22750343 DOI: 10.1016/j.saa.2012.05.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 05/10/2012] [Accepted: 05/17/2012] [Indexed: 05/19/2023]
Abstract
An aminonaphthoquinone based colorimetric chemosensor has been developed and demonstrated for the highly selective detection of Cu(II) ions in aqueous solution. The intramolecular charge transfer (ICT) transition exits in amine moiety directly attached to the quinone ring is modulated by the d-d transition of a square planar Cu(II)-receptor complex resulting in a change of color from yellow to blue. No significant color change was observed upon addition of other selected metal ions. The sensing property has been investigated using various spectral techniques (UV-Vis, fluorescence) and product analysis (Elemental analysis, magnetic moment, UV-Vis, FT-IR, EPR).
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Affiliation(s)
- Selvaraj Madhupriya
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India
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97
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Gaier ED, Eipper BA, Mains RE. Copper signaling in the mammalian nervous system: synaptic effects. J Neurosci Res 2012; 91:2-19. [PMID: 23115049 DOI: 10.1002/jnr.23143] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 08/05/2012] [Accepted: 08/17/2012] [Indexed: 12/14/2022]
Abstract
Copper is an essential metal present at high levels in the CNS. Its role as a cofactor in mitochondrial ATP production and in essential cuproenzymes is well defined. Menkes and Wilson's diseases are severe neurodegenerative conditions that demonstrate the importance of Cu transport into the secretory pathway. In the brain, intracellular levels of Cu, which is almost entirely protein bound, exceed extracellular levels by more than 100-fold. Cu stored in the secretory pathway is released in a Ca(2+)-dependent manner and can transiently reach concentrations over 100 μM at synapses. The ability of low micromolar levels of Cu to bind to and modulate the function of γ-aminobutyric acid type A (GABA(A)) receptors, N-methyl-D-aspartate (NMDA) receptors, and voltage-gated Ca(2+) channels contributes to its effects on synaptic transmission. Cu also binds to amyloid precursor protein and prion protein; both proteins are found at synapses and brain Cu homeostasis is disrupted in mice lacking either protein. Especially intriguing is the ability of Cu to affect AMP-activated protein kinase (AMPK), a monitor of cellular energy status. Despite this, few investigators have examined the direct effects of Cu on synaptic transmission and plasticity. Although the variability of results demonstrates complex influences of Cu that are highly method sensitive, these studies nevertheless strongly support important roles for endogenous Cu and new roles for Cu-binding proteins in synaptic function/plasticity and behavior. Further study of the many roles of Cu in nervous system function will reveal targets for intervention in other diseases in which Cu homeostasis is disrupted.
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Affiliation(s)
- E D Gaier
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030-3401, USA
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98
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Abstract
Impaired insulin secretion from pancreatic β-cells is a major factor in the pathogenesis of type 2 diabetes. The main regulator of insulin secretion is the plasma glucose concentration. Insulin secretion is modified by other nutrients, circulating hormones and the autonomic nervous system, as well as local paracrine and autocrine signals. Autocrine signalling involves diffusible molecules that bind to receptors on the same cell from which they have been released. The first transmitter to be implicated in the autocrine regulation of β-cell function was insulin itself. The importance of autocrine insulin signalling is underscored by the finding that mice lacking insulin receptors in β-cells are glucose intolerant. In addition to insulin, β-cells secrete a variety of additional substances, including peptides (e.g. amylin, chromogranin A and B and their cleavage products), neurotransmitters (ATP and γ-aminobutyric acid) and ions (e.g. zinc). Here we review the autocrine effects of substances secreted from β-cells, with a focus on acute effects in stimulus-secretion coupling, present some novel data and discuss the general significance of autocrine signals for the regulation of insulin secretion.
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Affiliation(s)
- M Braun
- Alberta Diabetes Institute, University of Alberta, Edmonton, Canada.
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99
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Chen J, Winarski KL, Myerburg MM, Pitt BR, Sheng S. Probing the structural basis of Zn2+ regulation of the epithelial Na+ channel. J Biol Chem 2012; 287:35589-35598. [PMID: 22930753 DOI: 10.1074/jbc.m112.394734] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Extracellular Zn(2+) activates the epithelial Na(+) channel (ENaC) by relieving Na(+) self-inhibition. However, a biphasic Zn(2+) dose response was observed, suggesting that Zn(2+) has dual effects on the channel (i.e. activating and inhibitory). To investigate the structural basis for this biphasic effect of Zn(2+), we examined the effects of mutating the 10 extracellular His residues of mouse γENaC. Four mutations within the finger subdomain (γH193A, γH200A, γH202A, and γH239A) significantly reduced the maximal Zn(2+) activation of the channel. Whereas γH193A, γH200A, and γH202A reduced the apparent affinity of the Zn(2+) activating site, γH239A diminished Na(+) self-inhibition and thus concealed the activating effects of Zn(2+). Mutation of a His residue within the palm subdomain (γH88A) abolished the low-affinity Zn(2+) inhibitory effect. Based on structural homology with acid-sensing ion channel 1, γAsp(516) was predicted to be in close proximity to γHis(88). Ala substitution of the residue (γD516A) blunted the inhibitory effect of Zn(2+). Our results suggest that external Zn(2+) regulates ENaC activity by binding to multiple extracellular sites within the γ-subunit, including (i) a high-affinity stimulatory site within the finger subdomain involving His(193), His(200), and His(202) and (ii) a low-affinity Zn(2+) inhibitory site within the palm subdomain that includes His(88) and Asp(516).
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Affiliation(s)
- Jingxin Chen
- Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Katie L Winarski
- Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Mike M Myerburg
- Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Bruce R Pitt
- Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Shaohu Sheng
- Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261.
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100
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Moraes-Silva L, Bueno TM, Franciscato C, Ineu RP, Pereira ME. Effectiveness of copper chloride in protecting against alterations induced by mercury chloride in newborn rats. J Biochem Mol Toxicol 2012; 26:354-9. [DOI: 10.1002/jbt.21429] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 05/29/2012] [Accepted: 06/11/2012] [Indexed: 11/10/2022]
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