1
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Côrte-Real BF, Hamad I, Arroyo Hornero R, Geisberger S, Roels J, Van Zeebroeck L, Dyczko A, van Gisbergen MW, Kurniawan H, Wagner A, Yosef N, Weiss SNY, Schmetterer KG, Schröder A, Krampert L, Haase S, Bartolomaeus H, Hellings N, Saeys Y, Dubois LJ, Brenner D, Kempa S, Hafler DA, Stegbauer J, Linker RA, Jantsch J, Müller DN, Kleinewietfeld M. Sodium perturbs mitochondrial respiration and induces dysfunctional Tregs. Cell Metab 2023; 35:299-315.e8. [PMID: 36754020 DOI: 10.1016/j.cmet.2023.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 11/07/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023]
Abstract
FOXP3+ regulatory T cells (Tregs) are central for peripheral tolerance, and their deregulation is associated with autoimmunity. Dysfunctional autoimmune Tregs display pro-inflammatory features and altered mitochondrial metabolism, but contributing factors remain elusive. High salt (HS) has been identified to alter immune function and to promote autoimmunity. By investigating longitudinal transcriptional changes of human Tregs, we identified that HS induces metabolic reprogramming, recapitulating features of autoimmune Tregs. Mechanistically, extracellular HS raises intracellular Na+, perturbing mitochondrial respiration by interfering with the electron transport chain (ETC). Metabolic disturbance by a temporary HS encounter or complex III blockade rapidly induces a pro-inflammatory signature and FOXP3 downregulation, leading to long-term dysfunction in vitro and in vivo. The HS-induced effect could be reversed by inhibition of mitochondrial Na+/Ca2+ exchanger (NCLX). Our results indicate that salt could contribute to metabolic reprogramming and that short-term HS encounter perturb metabolic fitness and long-term function of human Tregs with important implications for autoimmunity.
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Affiliation(s)
- Beatriz F Côrte-Real
- VIB Laboratory of Translational Immunomodulation, VIB Center for Inflammation Research (IRC), Hasselt University, 3590 Diepenbeek, Belgium; Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Ibrahim Hamad
- VIB Laboratory of Translational Immunomodulation, VIB Center for Inflammation Research (IRC), Hasselt University, 3590 Diepenbeek, Belgium; Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Rebeca Arroyo Hornero
- VIB Laboratory of Translational Immunomodulation, VIB Center for Inflammation Research (IRC), Hasselt University, 3590 Diepenbeek, Belgium; Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Sabrina Geisberger
- Experimental and Clinical Research Center, a joint cooperation of Max Delbrück Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, 13125 Berlin, Germany; Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Integrative Proteomics and Metabolomics, 13125 Berlin, Germany; DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10785 Berlin, Germany; Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany
| | - Joris Roels
- VIB-UGent Center for Inflammation Research, 9052 Gent, Belgium; VIB BioImaging Core, 9052 Gent, Belgium
| | - Lauren Van Zeebroeck
- VIB Laboratory of Translational Immunomodulation, VIB Center for Inflammation Research (IRC), Hasselt University, 3590 Diepenbeek, Belgium; Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Aleksandra Dyczko
- VIB Laboratory of Translational Immunomodulation, VIB Center for Inflammation Research (IRC), Hasselt University, 3590 Diepenbeek, Belgium; Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Marike W van Gisbergen
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, 6200 MD Maastricht, the Netherlands
| | - Henry Kurniawan
- Experimental & Molecular Immunology, Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg
| | - Allon Wagner
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Nir Yosef
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA 94720, USA; Center for Computational Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Chan Zuckerberg Biohub Investigator, San Francisco, CA 94158, USA; Ragon Institute of Massachusetts General Hospital, MIT and Harvard University, Cambridge, MA 02139, USA; Department of Systems Immunology, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Susanne N Y Weiss
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany
| | - Klaus G Schmetterer
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; Department of Laboratory Medicine, Medical University of Vienna, 1090 Vienna, Austria
| | - Agnes Schröder
- Department of Orthodontics, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Luka Krampert
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany
| | - Stefanie Haase
- Department of Neurology, University of Regensburg, 93053 Regensburg, Germany
| | - Hendrik Bartolomaeus
- Experimental and Clinical Research Center, a joint cooperation of Max Delbrück Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, 13125 Berlin, Germany; DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10785 Berlin, Germany
| | - Niels Hellings
- Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Yvan Saeys
- VIB-UGent Center for Inflammation Research, 9052 Gent, Belgium
| | - Ludwig J Dubois
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, 6200 MD Maastricht, the Netherlands
| | - Dirk Brenner
- Experimental & Molecular Immunology, Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg; Odense Research Center for Anaphylaxis (ORCA), Department of Dermatology and Allergy Center, Odense University Hospital, University of Southern Denmark, 5230 Odense, Denmark
| | - Stefan Kempa
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Integrative Proteomics and Metabolomics, 13125 Berlin, Germany
| | - David A Hafler
- Departments of Neurology and Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Johannes Stegbauer
- Department of Nephrology, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Ralf A Linker
- Department of Neurology, University of Regensburg, 93053 Regensburg, Germany
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; Institute for Medical Microbiology, Immunology, and Hygiene, University Hospital Cologne and Faculty of Medicine, University of Cologne, 50935 Cologne, Germany
| | - Dominik N Müller
- Experimental and Clinical Research Center, a joint cooperation of Max Delbrück Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, 13125 Berlin, Germany; DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10785 Berlin, Germany; Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany; Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Markus Kleinewietfeld
- VIB Laboratory of Translational Immunomodulation, VIB Center for Inflammation Research (IRC), Hasselt University, 3590 Diepenbeek, Belgium; Department of Immunology, Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium.
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2
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García-Casas P, Alvarez-Illera P, Gómez-Orte E, Cabello J, Fonteriz RI, Montero M, Alvarez J. The Mitochondrial Na +/Ca 2+ Exchanger Inhibitor CGP37157 Preserves Muscle Structure and Function to Increase Lifespan and Healthspan in Caenorhabditis elegans. Front Pharmacol 2021; 12:695687. [PMID: 34211399 PMCID: PMC8241105 DOI: 10.3389/fphar.2021.695687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/03/2021] [Indexed: 12/13/2022] Open
Abstract
We have reported recently that the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157 extends lifespan in Caenorhabditis elegans by a mechanism involving mitochondria, the TOR pathway and the insulin/IGF1 pathway. Here we show that CGP37157 significantly improved the evolution with age of the sarcomeric regular structure, delaying development of sarcopenia in C. elegans body wall muscle and increasing the average and maximum speed of the worms. Similarly, CGP37157 favored the maintenance of a regular mitochondrial structure during aging. We have also investigated further the mechanism of the effect of CGP37157 by studying its effect in mutants of aak-1;aak-2/AMP-activated kinase, sir-2.1/sirtuin, rsks-1/S6 kinase and daf-16/FOXO. We found that this compound was still effective increasing lifespan in all these mutants, indicating that these pathways are not involved in the effect. We have then monitored pharynx cytosolic and mitochondrial Ca2+ signalling and our results suggest that CGP37157 is probably inhibiting not only the mitochondrial Na+/Ca2+ exchanger, but also Ca2+ entry through the plasma membrane. Finally, a transcriptomic study detected that CGP37157 induced changes in lipid metabolism enzymes and a four-fold increase in the expression of ncx-6, one of the C. elegans mitochondrial Na+/Ca2+ exchangers. In summary, CGP37157 increases both lifespan and healthspan by a mechanism involving changes in cytosolic and mitochondrial Ca2+ homeostasis. Thus, Ca2+ signalling could be a promising target to act on aging.
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Affiliation(s)
- Paloma García-Casas
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and CSIC, Valladolid, Spain
| | - Pilar Alvarez-Illera
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and CSIC, Valladolid, Spain
| | - Eva Gómez-Orte
- Center for Biomedical Research of La Rioja (CIBIR), Logroño, Spain
| | - Juan Cabello
- Center for Biomedical Research of La Rioja (CIBIR), Logroño, Spain
| | - Rosalba I Fonteriz
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and CSIC, Valladolid, Spain
| | - Mayte Montero
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and CSIC, Valladolid, Spain
| | - Javier Alvarez
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and CSIC, Valladolid, Spain
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3
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Islam MM, Takeuchi A, Matsuoka S. Membrane current evoked by mitochondrial Na +-Ca 2+ exchange in mouse heart. J Physiol Sci 2020; 70:24. [PMID: 32354321 PMCID: PMC10717124 DOI: 10.1186/s12576-020-00752-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/24/2020] [Indexed: 01/19/2023]
Abstract
The electrogenicity of mitochondrial Na+-Ca2+ exchange (NCXm) had been controversial and no membrane current through it had been reported. We succeeded for the first time in recording NCXm-mediated currents using mitoplasts derived from mouse ventricle. Under conditions that K+, Cl-, and Ca2+ uniporter currents were inhibited, extra-mitochondrial Na+ induced inward currents with 1 μM Ca2+ in the pipette. The half-maximum concentration of Na+ was 35.6 mM. The inward current was diminished without Ca2+ in the pipette, and was augmented with 10 μM Ca2+. The Na+-induced inward currents were largely inhibited by CGP-37157, an NCXm blocker. However, the reverse mode of NCXm, which should be detected as an outward current, was hardly induced by extra-mitochondrial application of Ca2+ with Na+ in the pipette. It was concluded that NCXm is electrogenic. This property may be advantageous for facilitating Ca2+ extrusion from mitochondria, which has large negative membrane potential.
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Affiliation(s)
- Mohammed M Islam
- Department of Integrative and Systems Physiology, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Ayako Takeuchi
- Department of Integrative and Systems Physiology, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
- Life Science Innovation Center, University of Fukui, Fukui, 910-1193, Japan
| | - Satoshi Matsuoka
- Department of Integrative and Systems Physiology, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
- Life Science Innovation Center, University of Fukui, Fukui, 910-1193, Japan.
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4
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García-Casas P, Arias-Del-Val J, Alvarez-Illera P, Wojnicz A, de Los Ríos C, Fonteriz RI, Montero M, Alvarez J. The Neuroprotector Benzothiazepine CGP37157 Extends Lifespan in C. elegans Worms. Front Aging Neurosci 2019; 10:440. [PMID: 30705628 PMCID: PMC6344432 DOI: 10.3389/fnagi.2018.00440] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/31/2018] [Indexed: 11/14/2022] Open
Abstract
The benzothiazepine CGP37157 has shown neuroprotective effects in several in vitro models of excitotoxicity involving dysregulation of intracellular Ca2+ homeostasis. Although its mechanism of neuroprotection is unclear, it is probably related with some of its effects on Ca2+ homeostasis. CGP37157 is a well-known inhibitor of the mitochondrial Na+/Ca2+ exchanger (mNCX). However, it is not very specific and also blocks several other Ca2+ channels and transporters, including voltage-gated Ca2+ channels, plasma membrane Na+/Ca2+ exchanger and the Ca2+ homeostasis modulator 1 channel (CALHM1). In the present work, we have studied if CGP37157 could also induce changes in life expectancy. We now report that CGP37157 extends C. elegans lifespan by 10%–15% with a bell-shaped concentration-response, with high concentrations producing no effect. The effect was even larger (25% increase in life expectancy) in worms fed with heat-inactivated bacteria. The worm CGP37157 concentration producing maximum effect was measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and was close to the IC50 for inhibition of the Na+/Ca2+ exchanger. CGP37157 also extended the lifespan in eat-2 mutants (a model for caloric restriction), suggesting that caloric restriction is not involved in the mechanism of lifespan extension. Actually, CGP37157 produced no effect in mutants of the TOR pathway (daf15/unc24) or the insulin/insulin-like growth factor-1 (IGF-1) pathway (daf-2), indicating that the effect involves these pathways. Moreover, CGP37157 was also ineffective in nuo-6 mutants, which have a defect in the mitochondrial respiratory chain complex I. Since it has been described that neuroprotection by this compound in cell cultures is abolished by mitochondrial inhibitors, this suggests that life extension in C. elegans and neuroprotection in cell cultures may share a similar mechanism involving mitochondria.
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Affiliation(s)
- Paloma García-Casas
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, Institute of Biology and Molecular Genetics (IBGM), University of Valladolid and CSIC, Valladolid, Spain
| | - Jessica Arias-Del-Val
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, Institute of Biology and Molecular Genetics (IBGM), University of Valladolid and CSIC, Valladolid, Spain
| | - Pilar Alvarez-Illera
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, Institute of Biology and Molecular Genetics (IBGM), University of Valladolid and CSIC, Valladolid, Spain
| | - Aneta Wojnicz
- Department of Clinical Pharmacology, Instituto Teófilo Hernando, Instituto de Investigación Sanitaria la Princesa (IP), Hospital Universitario de la Princesa, Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Cristobal de Los Ríos
- Department of Clinical Pharmacology, Instituto Teófilo Hernando, Instituto de Investigación Sanitaria la Princesa (IP), Hospital Universitario de la Princesa, Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Rosalba I Fonteriz
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, Institute of Biology and Molecular Genetics (IBGM), University of Valladolid and CSIC, Valladolid, Spain
| | - Mayte Montero
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, Institute of Biology and Molecular Genetics (IBGM), University of Valladolid and CSIC, Valladolid, Spain
| | - Javier Alvarez
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, Institute of Biology and Molecular Genetics (IBGM), University of Valladolid and CSIC, Valladolid, Spain
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5
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Rokic MB, Castro P, Leiva-Salcedo E, Tomic M, Stojilkovic SS, Coddou C. Opposing Roles of Calcium and Intracellular ATP on Gating of the Purinergic P2X2 Receptor Channel. Int J Mol Sci 2018; 19:ijms19041161. [PMID: 29641486 PMCID: PMC5979340 DOI: 10.3390/ijms19041161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 11/16/2022] Open
Abstract
P2X2 receptors (P2X2R) exhibit a slow desensitization during the initial ATP application and a progressive, calcium-dependent increase in rates of desensitization during repetitive stimulation. This pattern is observed in whole-cell recordings from cells expressing recombinant and native P2X2R. However, desensitization is not observed in perforated-patched cells and in two-electrode voltage clamped oocytes. Addition of ATP, but not ATPγS or GTP, in the pipette solution also abolishes progressive desensitization, whereas intracellular injection of apyrase facilitates receptor desensitization. Experiments with injection of alkaline phosphatase or addition of staurosporine and ATP in the intracellular solution suggest a role for a phosphorylation-dephosphorylation in receptor desensitization. Mutation of residues that are potential phosphorylation sites identified a critical role of the S363 residue in the intracellular ATP action. These findings indicate that intracellular calcium and ATP have opposing effects on P2X2R gating: calcium allosterically facilitates receptor desensitization and ATP covalently prevents the action of calcium. Single cell measurements further revealed that intracellular calcium stays elevated after washout in P2X2R-expressing cells and the blockade of mitochondrial sodium/calcium exchanger lowers calcium concentrations during washout periods to basal levels, suggesting a role of mitochondria in this process. Therefore, the metabolic state of the cell can influence P2X2R gating.
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Affiliation(s)
- Milos B Rokic
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| | - Patricio Castro
- Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo 1781421, Chile.
- Laboratory of Developmental Physiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción 4030000, Chile.
| | - Elias Leiva-Salcedo
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile.
- Centro para el Desarrollo de Nanociencias y Nanotecnología (CEDENNA), Santiago 9170022, Chile.
| | - Melanija Tomic
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| | - Stanko S Stojilkovic
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| | - Claudio Coddou
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
- Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo 1781421, Chile.
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6
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de Los Rios C, Cano-Abad MF, Villarroya M, López MG. Chromaffin cells as a model to evaluate mechanisms of cell death and neuroprotective compounds. Pflugers Arch 2017; 470:187-198. [PMID: 28823085 DOI: 10.1007/s00424-017-2044-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 11/29/2022]
Abstract
In this review, we show how chromaffin cells have contributed to evaluate neuroprotective compounds with diverse mechanisms of action. Chromaffin cells are considered paraneurons, as they share many common features with neurons: (i) they synthesize, store, and release neurotransmitters upon stimulation and (ii) they express voltage-dependent calcium, sodium, and potassium channels, in addition to a wide variety of receptors. All these characteristics, together with the fact that primary cultures from bovine adrenal glands or chromaffin cells from the tumor pheochromocytoma cell line PC12 are easy to culture, make them an ideal model to study neurotoxic mechanisms and neuroprotective drugs. In the first part of this review, we will analyze the different cytotoxicity models related to calcium dyshomeostasis and neurodegenerative disorders like Alzheimer's or Parkinson's. Along the second part of the review, we describe how different classes of drugs have been evaluated in chromaffin cells to determine their neuroprotective profile in different neurodegenerative-related models.
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Affiliation(s)
- Cristobal de Los Rios
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Maria F Cano-Abad
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Manuela G López
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, Madrid, Spain. .,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain. .,Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid, Spain.
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7
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López-Gil A, Nanclares C, Méndez-López I, Martínez-Ramírez C, de Los Rios C, Padín-Nogueira JF, Montero M, Gandía L, García AG. The quantal catecholamine release from mouse chromaffin cells challenged with repeated ACh pulses is regulated by the mitochondrial Na + /Ca 2+ exchanger. J Physiol 2017; 595:2129-2146. [PMID: 27982456 DOI: 10.1113/jp273339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 11/30/2016] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS Upon repeated application of short ACh pulses to C57BL6J mouse chromaffin cells, the amperometrically monitored secretory responses promptly decayed to a steady-state level of around 25% of the initial response. A subsequent K+ pulse, however, overcame such decay. These data suggest that mouse chromaffin cells have a ready release-vesicle pool that is selectively recruited by the physiological neurotransmitter ACh. The ACh-sensitive vesicle pool is refilled and maintained by the rate of Ca2+ delivery from mitochondria to the cytosol, through the mitochondrial Na+ /Ca2+ exchanger (mNCX). ITH12662, a novel blocker of the mNCX, prevented the decay of secretion elicited by ACh pulses and delayed the rate of [Ca2+ ]c clearance. This regulatory pathway may be physiologically relevant in situations of prolonged stressful conflicts where a sustained catecholamine release is regulated by mitochondrial Ca2+ circulation through the mNCX, which couples respiration and ATP synthesis to long-term stimulation of chromaffin cells by endogenously released ACh. ABSTRACT Using caged-Ca2+ photorelease or paired depolarising pulses in voltage-clamped chromaffin cells (CCs), various pools of secretory vesicles with different readiness to undergo exocytosis have been identified. Whether these pools are present in unclamped CCs challenged with ACh, the physiological neurotransmitter at the splanchnic nerve-CC synapse, is unknown. We have explored here whether an ACh-sensitive ready-release vesicle pool (ASP) is present in C57BL6J mouse chromaffin cells (MCCs). Single cells were fast perfused with a Tyrode solution at 37°C, and challenged with 12 sequential ACh pulses (100 μm, 2 s, every 30 s) plus a K+ pulse given at the end (75 mm K+ ). After the first 2-3 ACh pulses the amperometrically monitored secretory responses promptly decayed to a steady-state level of around 25% of the initial response. The last K+ pulse, however, overcame such decay. Repeated ACh pulses to voltage-clamped cells elicited non-desensitising nicotinic currents. Also, the [Ca2+ ]c transients elicited by repeated ACh pulses that were superimposed on a stable baseline elevation did not undergo decay. The novel blocker of the mitochondrial Na+ /Ca2+ exchanger (mNCX) ITH12662 prevented the decay of secretion elicited by ACh pulses and delayed the rate of [Ca2+ ]c clearance. The experiments are compatible with the idea that C57BL6J MCCs have an ASP vesicle pool that is selectively recruited by the physiological neurotransmitter ACh and is regulated by the rate of Ca2+ delivery from mitochondria to the cytosol, through the mNCX.
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Affiliation(s)
- Angela López-Gil
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain
| | - Carmen Nanclares
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain
| | - Iago Méndez-López
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain
| | - Carmen Martínez-Ramírez
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain
| | - Cristóbal de Los Rios
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, c/ Diego de León, 62, 28006, Madrid, Spain
| | - J Fernando Padín-Nogueira
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain
| | - Mayte Montero
- Instituto de Biologia y Genética Molecular, Universidad de Valladolid, c/ Sanz y Forés, 3, 47003, Valladolid, Spain
| | - Luis Gandía
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain
| | - Antonio G García
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029, Madrid, Spain.,Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, c/ Diego de León, 62, 28006, Madrid, Spain
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8
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Strokin M, Reiser G. Mitochondrial Ca2+ Processing by a Unit of Mitochondrial Ca2+ Uniporter and Na+/Ca2+ Exchanger Supports the Neuronal Ca2+ Influx via Activated Glutamate Receptors. Neurochem Res 2016; 41:1250-62. [DOI: 10.1007/s11064-015-1819-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/23/2015] [Accepted: 12/27/2015] [Indexed: 10/22/2022]
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9
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Scheitlin CG, Julian JA, Shanmughapriya S, Madesh M, Tsoukias NM, Alevriadou BR. Endothelial mitochondria regulate the intracellular Ca2+ response to fluid shear stress. Am J Physiol Cell Physiol 2016; 310:C479-90. [PMID: 26739489 DOI: 10.1152/ajpcell.00171.2015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 01/04/2016] [Indexed: 02/04/2023]
Abstract
Shear stress is known to stimulate an intracellular free calcium concentration ([Ca(2+)]i) response in vascular endothelial cells (ECs). [Ca(2+)]i is a key second messenger for signaling that leads to vasodilation and EC survival. Although it is accepted that the shear-induced [Ca(2+)]i response is, in part, due to Ca(2+) release from the endoplasmic reticulum (ER), the role of mitochondria (second largest Ca(2+) store) is unknown. We hypothesized that the mitochondria play a role in regulating [Ca(2+)]i in sheared ECs. Cultured ECs, loaded with a Ca(2+)-sensitive fluorophore, were exposed to physiological levels of shear stress. Shear stress elicited [Ca(2+)]i transients in a percentage of cells with a fraction of them displaying oscillations. Peak magnitudes, percentage of oscillating ECs, and oscillation frequencies depended on the shear level. [Ca(2+)]i transients/oscillations were present when experiments were conducted in Ca(2+)-free solution (plus lanthanum) but absent when ECs were treated with a phospholipase C inhibitor, suggesting that the ER inositol 1,4,5-trisphosphate receptor is responsible for the [Ca(2+)]i response. Either a mitochondrial uncoupler or an electron transport chain inhibitor, but not a mitochondrial ATP synthase inhibitor, prevented the occurrence of transients and especially inhibited the oscillations. Knockdown of the mitochondrial Ca(2+) uniporter also inhibited the shear-induced [Ca(2+)]i transients/oscillations compared with controls. Hence, EC mitochondria, through Ca(2+) uptake/release, regulate the temporal profile of shear-induced ER Ca(2+) release. [Ca(2+)]i oscillation frequencies detected were within the range for activation of mechanoresponsive kinases and transcription factors, suggesting that dysfunctional EC mitochondria may contribute to cardiovascular disease by deregulating the shear-induced [Ca(2+)]i response.
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Affiliation(s)
- Christopher G Scheitlin
- Departments of Biomedical Engineering and Internal Medicine, Division of Cardiovascular Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Justin A Julian
- Departments of Biomedical Engineering and Internal Medicine, Division of Cardiovascular Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Santhanam Shanmughapriya
- Department of Medical Genetics and Molecular Biochemistry and Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania; and
| | - Muniswamy Madesh
- Department of Medical Genetics and Molecular Biochemistry and Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania; and
| | - Nikolaos M Tsoukias
- Department of Biomedical Engineering, Florida International University, Miami, Florida
| | - B Rita Alevriadou
- Departments of Biomedical Engineering and Internal Medicine, Division of Cardiovascular Medicine, and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio;
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10
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Neuroprotective profile of pyridothiazepines with blocking activity of the mitochondrial Na(+)/Ca(2+) exchanger. Eur J Med Chem 2015; 109:114-23. [PMID: 26774037 DOI: 10.1016/j.ejmech.2015.12.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 12/03/2015] [Accepted: 12/23/2015] [Indexed: 11/20/2022]
Abstract
The mitochondrial Na(+)/Ca(2+) exchanger plays an important role in the control of cytosolic Ca(2+) cycling in excitable cells, essential for the regulation of a plethora of Ca(2+)-dependent physio-pathological events, such as apoptosis in the presence of a Ca(2+) overload. There are very few pharmacological tools available to study both physiological and pathological implications of the mitochondrial Na(+)/Ca(2+) exchanger, where the benzothiazepine CGP37157 is the best-known ligand, used since the 1980s. However, it is not an efficient blocker and lacks of selectivity, as also blocks several other cellular Ca(2+) transporters. Moreover, CGP37157 is a very lipophilic drug, showing very poor water solubility, what has hindered its therapeutic use. Attempting to improve its pharmacokinetic profile as well as its potency and selectivity, we herein describe the synthesis of new CGP37157 analogs, where the benzene-fused ring has been replaced by a pyridine. On top of a better water solubility and lower log P value, some of these new pyridothiazepine derivatives also presented a higher capacity to regulate the mitochondrial Ca(2+) clearance, while keeping the neuroprotective properties presented in the head compound CGP37157.
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11
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Martínez-Sanz FJ, Lajarín-Cuesta R, Moreno-Ortega AJ, González-Lafuente L, Fernández-Morales JC, López-Arribas R, Cano-Abad MF, Ríos CDL. Benzothiazepine CGP37157 Analogues Exert Cytoprotection in Various in Vitro Models of Neurodegeneration. ACS Chem Neurosci 2015; 6:1626-36. [PMID: 26192029 DOI: 10.1021/acschemneuro.5b00161] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mitochondria regulate cellular Ca(2+) oscillations, taking up Ca(2+) through its uniporter and releasing it through the mitochondrial sodium/calcium exchanger. The role of mitochondria in the regulation of Ca(2+) cycle has received much attention recently, as it is a central stage in neuronal survival and death processes. Over the last decades, the 4,1-benzothiazepine CGP37157 has been the only available blocker of the mitochondrial sodium/calcium exchanger, although it targets several other calcium transporters. We report the synthesis of 4,1-benzothiazepine derivatives with the goal of enhancing mitochondrial sodium/calcium exchanger blockade and selectivity, and the evaluation of their cytoprotective effect. The compound 4c presented an interesting neuroprotective profile in addition to an important blockade of the mitochondrial sodium/calcium exchanger. The use of this benzothiazepine could help to understand the physiological functions of the mitochondrial sodium/calcium exchanger. In addition, we hypothesize that a moderate blockade of the mitochondrial sodium/calcium exchanger would provide enhanced neuroprotection in neurons.
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Affiliation(s)
- Francisco J. Martínez-Sanz
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
- Servicio
de Farmacología Clínica, Instituto de Investigación
Sanitaria, Hospital Universitario de la Princesa, C/Diego de
León, 62, 28006 Madrid, Spain
| | - Rocío Lajarín-Cuesta
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Ana J. Moreno-Ortega
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
- Servicio
de Farmacología Clínica, Instituto de Investigación
Sanitaria, Hospital Universitario de la Princesa, C/Diego de
León, 62, 28006 Madrid, Spain
| | - Laura González-Lafuente
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
- Servicio
de Farmacología Clínica, Instituto de Investigación
Sanitaria, Hospital Universitario de la Princesa, C/Diego de
León, 62, 28006 Madrid, Spain
| | - Jose C. Fernández-Morales
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Raquel López-Arribas
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - María F. Cano-Abad
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
- Servicio
de Farmacología Clínica, Instituto de Investigación
Sanitaria, Hospital Universitario de la Princesa, C/Diego de
León, 62, 28006 Madrid, Spain
| | - Cristóbal de los Ríos
- Instituto
Teófilo Hernando and Departamento de Farmacología y
Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
- Servicio
de Farmacología Clínica, Instituto de Investigación
Sanitaria, Hospital Universitario de la Princesa, C/Diego de
León, 62, 28006 Madrid, Spain
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12
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Raiteri L, Raiteri M. Multiple functions of neuronal plasma membrane neurotransmitter transporters. Prog Neurobiol 2015; 134:1-16. [PMID: 26300320 DOI: 10.1016/j.pneurobio.2015.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/09/2015] [Accepted: 08/18/2015] [Indexed: 12/11/2022]
Abstract
Removal from receptors of neurotransmitters just released into synapses is one of the major steps in neurotransmission. Transporters situated on the plasma membrane of nerve endings and glial cells perform the process of neurotransmitter (re)uptake. Because the density of transporters in the membranes can fluctuate, transporters can determine the transmitter concentrations at receptors, thus modulating indirectly the excitability of neighboring neurons. Evidence is accumulating that neurotransmitter transporters can exhibit multiple functions. Being bidirectional, neurotransmitter transporters can mediate transmitter release by working in reverse, most often under pathological conditions that cause ionic gradient dysregulations. Some transporters reverse to release transmitters, like dopamine or serotonin, when activated by 'indirectly acting' substrates, like the amphetamines. Some transporters exhibit as one major function the ability to capture transmitters into nerve terminals that perform insufficient synthesis. Transporter activation can generate conductances that regulate directly neuronal excitability. Synaptic and non-synaptic transporters play different roles. Cytosolic Na(+) elevations accompanying transport can interact with plasmalemmal or/and mitochondrial Na(+)/Ca(2+) exchangers thus generating calcium signals. Finally, neurotransmitter transporters can behave as receptors mediating releasing stimuli able to cause transmitter efflux through multiple mechanisms. Neurotransmitter transporters are therefore likely to play hitherto unknown roles in multiple therapeutic treatments.
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Affiliation(s)
- Luca Raiteri
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy; Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy; National Institute of Neuroscience, Genoa, Italy
| | - Maurizio Raiteri
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy; Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy; National Institute of Neuroscience, Genoa, Italy.
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13
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Milanese M, Romei C, Usai C, Oliveri M, Raiteri L. A new function for glycine GlyT2 transporters: Stimulation of γ-aminobutyric acid release from cerebellar nerve terminals through GAT1 transporter reversal and Ca2+-dependent anion channels. J Neurosci Res 2013; 92:398-408. [DOI: 10.1002/jnr.23321] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 10/08/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Marco Milanese
- Department of Pharmacy; Pharmacology and Toxicology Section, University of Genoa; Genoa Italy
- Center of Excellence for Biomedical Research; University of Genoa; Genoa Italy
| | - Cristina Romei
- Department of Pharmacy; Pharmacology and Toxicology Section, University of Genoa; Genoa Italy
| | - Cesare Usai
- Institute of Biophysics; National Research Council; Genoa Italy
| | - Martina Oliveri
- Department of Pharmacy; Pharmacology and Toxicology Section, University of Genoa; Genoa Italy
| | - Luca Raiteri
- Department of Pharmacy; Pharmacology and Toxicology Section, University of Genoa; Genoa Italy
- Center of Excellence for Biomedical Research; University of Genoa; Genoa Italy
- National Institute of Neuroscience; Genoa Italy
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14
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Mitochondrial exchanger NCLX plays a major role in the intracellular Ca2+ signaling, gliotransmission, and proliferation of astrocytes. J Neurosci 2013; 33:7206-19. [PMID: 23616530 DOI: 10.1523/jneurosci.5721-12.2013] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mitochondria not only provide cells with energy, but are central to Ca(2+) signaling. Powered by the mitochondrial membrane potential, Ca(2+) enters the mitochondria and is released into the cytosol through a mitochondrial Na(+)/Ca(2+) exchanger. We established that NCLX, a newly discovered mitochondrial Na(+)/Ca(2+) exchanger, is expressed in astrocytes isolated from mice of either sex. Immunoblot analysis of organellar fractions showed that the location of NCLX is confined to mitochondria. Using pericam-based mitochondrial Ca(2+) imaging and NCLX inhibition either by siRNA or by the pharmacological blocker CGP37157, we demonstrated that NCLX is responsible for mitochondrial Ca(2+) extrusion. Suppression of NCLX function altered cytosolic Ca(2+) dynamics in astrocytes and this was mediated by a strong effect of NCLX activity on Ca(2+) influx via store-operated entry. Furthermore, Ca(2+) influx through the store-operated Ca(2+) entry triggered strong, whereas ER Ca(2+) release triggered only modest mitochondrial Ca(2+) transients, indicating that the functional cross talk between the plasma membrane and mitochondrial domains is particularly strong in astrocytes. Finally, silencing of NCLX expression significantly reduced Ca(2+)-dependent processes in astrocytes (i.e., exocytotic glutamate release, in vitro wound closure, and proliferation), whereas Ca(2+) wave propagation was not affected. Therefore, NCLX, by meditating astrocytic mitochondrial Na(+)/Ca(2+) exchange, links between mitochondria and plasma membrane Ca(2+) signaling, thereby modulating cytoplasmic Ca(2+) transients required to control a diverse array of astrocyte functions.
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15
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The Role of the Mitochondrial NCX in the Mechanism of Neurodegeneration in Parkinson’s Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:241-9. [DOI: 10.1007/978-1-4614-4756-6_20] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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16
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Abstract
Intracellular calcium dynamics is critical for many functions of cerebellar granule cells (GrCs) including membrane excitability, synaptic plasticity, apoptosis, and regulation of gene transcription. Recent measurements of calcium responses in GrCs to depolarization and synaptic stimulation reveal spatial compartmentalization and heterogeneity within dendrites of these cells. However, the main determinants of local calcium dynamics in GrCs are still poorly understood. One reason is that there have been few published studies of calcium dynamics in intact GrCs in their native environment. In the absence of complete information, biophysically realistic models are useful for testing whether specific Ca(2+) handling mechanisms may account for existing experimental observations. Simulation results can be used to identify critical measurements that would discriminate between different models. In this review, we briefly describe experimental studies and phenomenological models of Ca(2+) signaling in GrC, and then discuss a particular biophysical model, with a special emphasis on an approach for obtaining information regarding the distribution of Ca(2+) handling systems under conditions of incomplete experimental data. Use of this approach suggests that Ca(2+) channels and fixed endogenous Ca(2+) buffers are highly heterogeneously distributed in GrCs. Research avenues for investigating calcium dynamics in GrCs by a combination of experimental and modeling studies are proposed.
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Affiliation(s)
- Elena È Saftenku
- Department of General Physiology of Nervous System, A. A. Bogomoletz Institute of Physiology, 4 Bogomoletz St., Kyiv 01024, Ukraine.
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17
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Palty R, Hershfinkel M, Sekler I. Molecular identity and functional properties of the mitochondrial Na+/Ca2+ exchanger. J Biol Chem 2012; 287:31650-7. [PMID: 22822063 DOI: 10.1074/jbc.r112.355867] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial membrane potential that powers the generation of ATP also facilitates mitochondrial Ca(2+) shuttling. This process is fundamental to a wide range of cellular activities, as it regulates ATP production, shapes cytosolic and endoplasmic recticulum Ca(2+) signaling, and determines cell fate. Mitochondrial Ca(2+) transport is mediated primarily by two major transporters: a Ca(2+) uniporter that mediates Ca(2+) uptake and a Na(+)/Ca(2+) exchanger that subsequently extrudes mitochondrial Ca(2+). In this minireview, we focus on the specific role of the mitochondrial Na(+)/Ca(2+) exchanger and describe its ion exchange mechanism, regulation by ions, and putative partner proteins. We discuss the recent molecular identification of the mitochondrial exchanger and how its activity is linked to physiological and pathophysiological processes.
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Affiliation(s)
- Raz Palty
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA. palty35@berkeley
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18
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González-Lafuente L, Egea J, León R, Martínez-Sanz FJ, Monjas L, Perez C, Merino C, García-De Diego AM, Rodríguez-Franco MI, García AG, Villarroya M, López MG, de los Ríos C. Benzothiazepine CGP37157 and its isosteric 2'-methyl analogue provide neuroprotection and block cell calcium entry. ACS Chem Neurosci 2012; 3:519-29. [PMID: 22860221 DOI: 10.1021/cn300009e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/26/2012] [Indexed: 11/28/2022] Open
Abstract
Benzothiazepine CGP37157 is widely used as tool to explore the role of mitochondria in cell Ca(2+) handling, by its blocking effect of the mitochondria Na(+)/Ca(2+) exchanger. Recently, CGP37157 has shown to exhibit neuroprotective properties. In the trend to improve its neuroprotection profile, we have synthesized ITH12505, an isosteric analogue having a methyl instead of chlorine at C2' of the phenyl ring. ITH12505 has exerted neuroprotective properties similar to CGP37157 in chromaffin cells and hippocampal slices stressed with veratridine. Also, both compounds afforded neuroprotection in hippocampal slices stressed with glutamate. However, while ITH12505 elicited protection in SH-SY5Y cells stressed with oligomycin A/rotenone, CGP37157 was ineffective. In hippocampal slices subjected to oxygen/glucose deprivation plus reoxygenation, ITH12505 offered protection at 3-30 μM, while CGP37157 only protected at 30 μM. Both compounds caused blockade of Ca(2+) channels in high K(+)-depolarized SH-SY5Y cells. An in vitro experiment for assaying central nervous system penetration (PAMPA-BBB; parallel artificial membrane permeability assay for blood-brain barrier) revealed that both compounds could cross the blood-brain barrier, thus reaching their biological targets in the central nervous system. In conclusion, by causing a mild isosteric replacement in the benzothiazepine CGP37157, we have obtained ITH12505, with improved neuroprotective properties. These findings may inspire the design and synthesis of new benzothiazepines targeting mitochondrial Na(+)/Ca(2+) exchanger and L-type voltage-dependent Ca(2+) channels, having antioxidant properties.
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Affiliation(s)
- Laura González-Lafuente
- Instituto de Investigación
Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, C/Diego de León,
62, 28006 Madrid, Spain
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Javier Egea
- Instituto de Investigación
Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, C/Diego de León,
62, 28006 Madrid, Spain
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Rafael León
- Instituto de Investigación
Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, C/Diego de León,
62, 28006 Madrid, Spain
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Francisco J. Martínez-Sanz
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Leticia Monjas
- Instituto de Química Médica
(IQM), Consejo Superior de Investigaciones Científicas (CSIC), C/Juan de la Cierva, 3, 28006 Madrid, Spain
| | - Concepción Perez
- Instituto de Química Médica
(IQM), Consejo Superior de Investigaciones Científicas (CSIC), C/Juan de la Cierva, 3, 28006 Madrid, Spain
| | - Cristina Merino
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Antonio M. García-De Diego
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - María I. Rodríguez-Franco
- Instituto de Química Médica
(IQM), Consejo Superior de Investigaciones Científicas (CSIC), C/Juan de la Cierva, 3, 28006 Madrid, Spain
| | - Antonio G. García
- Instituto de Investigación
Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, C/Diego de León,
62, 28006 Madrid, Spain
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Mercedes Villarroya
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
| | - Manuela G. López
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
- Instituto Universitario La Paz-IDIPaz, Universidad Autónoma de Madrid, Spain
| | - Cristóbal de los Ríos
- Instituto de Investigación
Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, C/Diego de León,
62, 28006 Madrid, Spain
- Instituto Teófilo Hernando
and Departamento de Farmacología y Terapéutica, Facultad
de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, 28029 Madrid, Spain
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19
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Rodriguez P, Satorre M, Beconi M. Effect of two intracellular calcium modulators on sperm motility and heparin-induced capacitation in cryopreserved bovine spermatozoa. Anim Reprod Sci 2012; 131:135-42. [DOI: 10.1016/j.anireprosci.2012.03.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 03/21/2012] [Accepted: 03/25/2012] [Indexed: 11/26/2022]
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20
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Palty R, Sekler I. The mitochondrial Na(+)/Ca(2+) exchanger. Cell Calcium 2012; 52:9-15. [PMID: 22430014 DOI: 10.1016/j.ceca.2012.02.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 02/24/2012] [Accepted: 02/27/2012] [Indexed: 01/20/2023]
Abstract
Powered by the steep mitochondrial membrane potential Ca(2+) permeates into the mitochondria via the Ca(2+) uniporter and is then extruded by a mitochondrial Na(+)/Ca(2+) exchanger. This mitochondrial Ca(2+) shuttling regulates the rate of ATP production and participates in cellular Ca(2+) signaling. Despite the fact that the exchanger was functionally identified 40 years ago its molecular identity remained a mystery. Early studies on isolated mitochondria and intact cells characterized the functional properties of a mitochondrial Na(+)/Ca(2+) exchanger, and showed that it possess unique functional fingerprints such as Li(+)/Ca(2+) exchange and that it is displaying selective sensitivity to inhibitors. Purification of mitochondria proteins combined with functional reconstitution led to the isolation of a polypeptide candidate of the exchanger but failed to molecularly identify it. A turning point in the search for the exchanger molecule came with the recent cloning of the last member of the Na(+)/Ca(2+) exchanger superfamily termed NCLX (Na(+)/Ca(2+)/Li(+) exchanger). NCLX is localized in the inner mitochondria membrane and its expression is linked to mitochondria Na(+)/Ca(2+) exchange matching the functional fingerprints of the putative mitochondrial Na(+)/Ca(2+) exchanger. Thus NCLX emerges as the long sought mitochondria Na(+)/Ca(2+) exchanger and provide a critical molecular handle to study mitochondrial Ca(2+) signaling and transport. Here we summarize some of the main topics related to the molecular properties of the Na(+)/Ca(2+) exchanger, beginning with the early days of its functional identification, its kinetic properties and regulation, and culminating in its molecular identification.
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Affiliation(s)
- Raz Palty
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA.
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21
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Romei C, Di Prisco S, Raiteri M, Raiteri L. Glycine release provoked by disturbed Na+, K+ and Ca2+ homeostasis in cerebellar nerve endings: roles of Ca2+ channels, Na+/Ca2+ exchangers and GlyT2 transporter reversal. J Neurochem 2011; 119:50-63. [DOI: 10.1111/j.1471-4159.2011.07401.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Neumann JT, Diaz-Sylvester PL, Fleischer S, Copello JA. CGP-37157 inhibits the sarcoplasmic reticulum Ca²+ ATPase and activates ryanodine receptor channels in striated muscle. Mol Pharmacol 2010; 79:141-7. [PMID: 20923851 DOI: 10.1124/mol.110.067165] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
7-Chloro-5-(2-chlorophenyl)-1,5-dihydro-4,1-benzothiazepin-2(3H)-one [CGP-37157 (CGP)], a benzothiazepine derivative of clonazepam, is commonly used as a blocker of the mitochondrial Na+/Ca²+ exchanger. However, evidence suggests that CGP could also affect other targets, such as L-type Ca²+ channels and plasmalemma Na+/Ca²+ exchanger. Here, we tested the possibility of a direct modulation of ryanodine receptor channels (RyRs) and/or sarco/endoplasmic reticulum Ca²+-stimulated ATPase (SERCA) by CGP. In the presence of ruthenium red (inhibitor of RyRs), CGP decreased SERCA-mediated Ca²+ uptake of cardiac and skeletal sarcoplasmic reticulum (SR) microsomes (IC₅₀ values of 6.6 and 9.9 μM, respectively). The CGP effects on SERCA activity correlated with a decreased V(max) of ATPase activity of SERCA-enriched skeletal SR fractions. CGP (≥ 5 μM) also increased RyR-mediated Ca²+ leak from skeletal SR microsomes. Planar bilayer studies confirmed that both cardiac and skeletal RyRs are directly activated by CGP (EC(50) values of 9.4 and 12.0 μM, respectively). In summary, we found that CGP inhibits SERCA and activates RyR channels. Hence, the action of CGP on cellular Ca²+ homeostasis reported in the literature of cardiac, skeletal muscle, and other nonmuscle systems requires further analysis to take into account the contribution of all CGP-sensitive Ca²+ transporters.
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Affiliation(s)
- Jake T Neumann
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
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Feldman B, Fedida-Metula S, Nita J, Sekler I, Fishman D. Coupling of mitochondria to store-operated Ca(2+)-signaling sustains constitutive activation of protein kinase B/Akt and augments survival of malignant melanoma cells. Cell Calcium 2010; 47:525-37. [PMID: 20605628 DOI: 10.1016/j.ceca.2010.05.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 05/04/2010] [Accepted: 05/06/2010] [Indexed: 11/29/2022]
Abstract
Mitochondria are emerging as a major hub for cellular Ca(2+)-signaling, though their contribution to Ca(2+)-driven growth- and survival-promoting events in cancer is poorly understood. Here employing flow cytometry to monitor mitochondrial and cytosolic Ca(2+), we assessed trans-mitochondrial Ca(2+)-transport and store-operated Ca(2+)-influx (store-operated channels (SOC)) in malignant vs. non-malignant B16BL6 melanoma clones. Remarkably, mitochondrial Ca(2+)-fluxes measured in whole cells or in isolated mitochondria were accelerated in the malignant clones compared to their non-malignant counterpart clones. This coincided with enhanced SOC-mediated Ca(2+)-influx and high levels of constitutively active protein kinase B/Akt (PKB). Interruption of trans-mitochondrial Ca(2+)-transport in the malignant cells with an antagonist of the mitochondrial Na(+)/Ca(2+) exchanger, CGP-37157, abolsihed SOC-mediated Ca(2+)-influx, inactivated PKB, retarded cell growth and increased vulnerability to apoptosis. Similarly, direct SOC blockade by silencing Stim1 inhibited PKB, indicating that the crosstalk between SOC and mitochondria is essential to preserve PKB in constitutively active state. Finally, the retraction of mitochondria from sub-plasmalemmal micro-domains triggered by Fis1 over-expression inhibited SOC-coupled trans-mitochondrial Ca(2+)-flux, Ca(2+)-entry via SOC and PKB activity. Taken together, our data show that in the malignant melanoma cells, the functional and spatial relationship of up-regulated mitochondrial Ca(2+)-transport to the SOC sustains the robust Ca(2+)-responses and down-stream signaling critical for apoptosis-resistance and proliferation.
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Affiliation(s)
- Ben Feldman
- Department of Morphology, Ben-Gurion University Cancer Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Abstract
Mitochondrial Ca(2+) efflux is linked to numerous cellular activities and pathophysiological processes. Although it is established that an Na(+)-dependent mechanism mediates mitochondrial Ca(2+) efflux, the molecular identity of this transporter has remained elusive. Here we show that the Na(+)/Ca(2+) exchanger NCLX is enriched in mitochondria, where it is localized to the cristae. Employing Ca(2+) and Na(+) fluorescent imaging, we demonstrate that mitochondrial Na(+)-dependent Ca(2+) efflux is enhanced upon overexpression of NCLX, is reduced by silencing of NCLX expression by siRNA, and is fully rescued by the concomitant expression of heterologous NCLX. NCLX-mediated mitochondrial Ca(2+) transport was inhibited, moreover, by CGP-37157 and exhibited Li(+) dependence, both hallmarks of mitochondrial Na(+)-dependent Ca(2+) efflux. Finally, NCLX-mediated mitochondrial Ca(2+) exchange is blocked in cells expressing a catalytically inactive NCLX mutant. Taken together, our results converge to the conclusion that NCLX is the long-sought mitochondrial Na(+)/Ca(2+) exchanger.
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Fekete A, Franklin L, Ikemoto T, Rózsa B, Lendvai B, Sylvester Vizi E, Zelles T. Mechanism of the persistent sodium current activator veratridine-evoked Ca elevation: implication for epilepsy. J Neurochem 2009; 111:745-56. [PMID: 19719824 DOI: 10.1111/j.1471-4159.2009.06368.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although the role of Na(+) in several aspects of Ca(2+) regulation has already been shown, the exact mechanism of intracellular Ca(2+) concentration ([Ca(2+)](i)) increase resulting from an enhancement in the persistent, non-inactivating Na(+) current (I(Na,P)), a decisive factor in certain forms of epilepsy, has yet to be resolved. Persistent Na(+) current, evoked by veratridine, induced bursts of action potentials and sustained membrane depolarization with monophasic intracellular Na(+) concentration ([Na(+)](i)) and biphasic [Ca(2+)](i) increase in CA1 pyramidal cells in acute hippocampal slices. The Ca(2+) response was tetrodotoxin- and extracellular Ca(2+)-dependent and ionotropic glutamate receptor-independent. The first phase of [Ca(2+)](i) rise was the net result of Ca(2+) influx through voltage-gated Ca(2+) channels and mitochondrial Ca(2+) sequestration. The robust second phase in addition involved reverse operation of the Na(+)-Ca(2+) exchanger and mitochondrial Ca(2+) release. We excluded contribution of the endoplasmic reticulum. These results demonstrate a complex interaction between persistent, non-inactivating Na(+) current and [Ca(2+)](i) regulation in CA1 pyramidal cells. The described cellular mechanisms are most likely part of the pathomechanism of certain forms of epilepsy that are associated with I(Na,P). Describing the magnitude, temporal pattern and sources of Ca(2+) increase induced by I(Na,P) may provide novel targets for antiepileptic drug therapy.
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Affiliation(s)
- Adám Fekete
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Szigony, Hungary
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Abstract
Cannabinoids and the endocannabinoid system have attracted considerable interest for therapeutic applications. Nevertheless, the mechanism of action of one of the main nonpsychoactive phytocannabinoids, cannabidiol (CBD), remains elusive despite potentially beneficial properties as an anti-convulsant and neuroprotectant. Here, we characterize the mechanisms by which CBD regulates Ca(2+) homeostasis and mediates neuroprotection in neuronal preparations. Imaging studies in hippocampal cultures using fura-2 AM suggested that CBD-mediated Ca(2+) regulation is bidirectional, depending on the excitability of cells. Under physiological K(+)/Ca(2+) levels, CBD caused a subtle rise in [Ca(2+)](i), whereas CBD reduced [Ca(2+)](i) and prevented Ca(2+) oscillations under high-excitability conditions (high K(+) or exposure to the K(+) channel antagonist 4AP). Regulation of [Ca(2+)](i) was not primarily mediated by interactions with ryanodine or IP(3) receptors of the endoplasmic reticulum. Instead, dual-calcium imaging experiments with a cytosolic (fura-2 AM) and a mitochondrial (Rhod-FF, AM) fluorophore implied that mitochondria act as sinks and sources for CBD's [Ca(2+)](i) regulation. Application of carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP) and the mitochondrial Na(+)/Ca(2+) exchange inhibitor, CGP 37157, but not the mitochondrial permeability transition pore inhibitor cyclosporin A, prevented subsequent CBD-induced Ca(2+) responses. In established human neuroblastoma cell lines (SH-SY5Y) treated with mitochondrial toxins, CBD (0.1 and 1 microm) was neuroprotective against the uncoupler FCCP (53% protection), and modestly protective against hydrogen peroxide- (16%) and oligomycin- (15%) mediated cell death, a pattern also confirmed in cultured hippocampal neurons. Thus, under pathological conditions involving mitochondrial dysfunction and Ca(2+) dysregulation, CBD may prove beneficial in preventing apoptotic signaling via a restoration of Ca(2+) homeostasis.
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Castaldo P, Cataldi M, Magi S, Lariccia V, Arcangeli S, Amoroso S. Role of the mitochondrial sodium/calcium exchanger in neuronal physiology and in the pathogenesis of neurological diseases. Prog Neurobiol 2008; 87:58-79. [PMID: 18952141 DOI: 10.1016/j.pneurobio.2008.09.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 09/23/2008] [Accepted: 09/29/2008] [Indexed: 11/26/2022]
Abstract
In neurons, as in other excitable cells, mitochondria extrude Ca(2+) ions from their matrix in exchange with cytosolic Na(+) ions. This exchange is mediated by a specific transporter located in the inner mitochondrial membrane, the mitochondrial Na(+)/Ca(2+) exchanger (NCX(mito)). The stoichiometry of NCX(mito)-operated Na(+)/Ca(2+) exchange has been the subject of a long controversy, but evidence of an electrogenic 3 Na(+)/1 Ca(2+) exchange is increasing. Although the molecular identity of NCX(mito) is still undetermined, data obtained in our laboratory suggest that besides the long-sought and as yet unfound mitochondrial-specific NCX, the three isoforms of plasmamembrane NCX can contribute to NCX(mito) in neurons and astrocytes. NCX(mito) has a role in controlling neuronal Ca(2+) homeostasis and neuronal bioenergetics. Indeed, by cycling the Ca(2+) ions captured by mitochondria back to the cytosol, NCX(mito) determines a shoulder in neuronal [Ca(2+)](c) responses to neurotransmitters and depolarizing stimuli which may then outlast stimulus duration. This persistent NCX(mito)-dependent Ca(2+) release has a role in post-tetanic potentiation, a form of short-term synaptic plasticity. By controlling [Ca(2+)](m) NCX(mito) regulates the activity of the Ca(2+)-sensitive enzymes pyruvate-, alpha-ketoglutarate- and isocitrate-dehydrogenases and affects the activity of the respiratory chain. Convincing experimental evidence suggests that supraphysiological activation of NCX(mito) contributes to neuronal cell death in the ischemic brain and, in epileptic neurons coping with seizure-induced ion overload, reduces the ability to reestablish normal ionic homeostasis. These data suggest that NCX(mito) could represent an important target for the development of new neurological drugs.
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Affiliation(s)
- P Castaldo
- Department of Neuroscience, Section of Pharmacology, Università Politecnica delle Marche, Via Tronto 10/A, 60020 Torrette di Ancona, Ancona, Italy
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Thu LT, Ahn JR, Woo SH. Inhibition of L-type Ca2+ channel by mitochondrial Na+-Ca2+ exchange inhibitor CGP-37157 in rat atrial myocytes. Eur J Pharmacol 2006; 552:15-9. [PMID: 17054940 DOI: 10.1016/j.ejphar.2006.09.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Revised: 09/06/2006] [Accepted: 09/07/2006] [Indexed: 11/16/2022]
Abstract
7-chloro-5-(2-chlorophenyl)-1,5-dihydro-4,1-benzothiazepine-2(3H)-one (CGP-37157) inhibits mitochondrial Na(+)-Ca(2+) exchange. It is often used as an experimental tool for studying the role of the mitochondrial Na(+)-Ca(2+) exchanger in Ca(2+) signaling. Because the selectivity of CGP-37157 in adult cardiomyocytes has not been confirmed, we tested whether CGP-37157 affects the L-type Ca(2+) channel using a whole-cell patch-clamp in adult rat atrial myocytes. We found that CGP-37157 suppressed L-type Ca(2+) current (I(Ca)) with IC(50) of approximately 0.27 microM, without altering the voltage dependence of the current-voltage relationships. CGP-37157 inhibited the Ba(2+) current (I(Ba)) through the Ca(2+) channel with a similar dose-response. The inhibitory effects of CGP-37157 on I(Ca) or I(Ba) were resistant to the intracellular Ca(2+) buffering. Intracellular application of CGP-37157 did not significantly alter I(Ca). The combination of CGP-37157 with known Ca(2+) channel inhibitor diltiazem yielded antagonism consistent with additivity of response. Our data suggest that CGP-37157 directly suppresses the L-type Ca(2+) channel in intact adult cardiomyocytes.
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Affiliation(s)
- Le Thi Thu
- College of Pharmacy, Chungnam National University, 220 Gungdong, Yuseong-Gu, Daejeon, 305-764, South Korea.
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Sheldon C, Diarra A, Cheng YM, Church J. Sodium influx pathways during and after anoxia in rat hippocampal neurons. J Neurosci 2005; 24:11057-69. [PMID: 15590922 PMCID: PMC6730285 DOI: 10.1523/jneurosci.2829-04.2004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mechanisms that contribute to Na+ influx during and immediately after 5 min anoxia were investigated in cultured rat hippocampal neurons loaded with the Na+-sensitive fluorophore sodium-binding benzofuran isophthalate. During anoxia, an influx of Na+ in the face of reduced Na+,K+-ATPase activity caused a rise in [Na+]i. After the return to normoxia, Na+,K+-ATPase activity mediated the recovery of [Na+]i despite continued Na+ entry. Sodium influx during and after anoxia occurred through multiple pathways and increased the longer neurons were maintained in culture. Under the experimental conditions used, Na+ entry during anoxia did not reflect the activation of ionotropic glutamate receptors, TTX- or lidocaine-sensitive Na+ channels, plasmalemmal Na+/Ca2+ exchange, Na+/H+ exchange, or HCO3--dependent mechanisms; rather, contributions were received from a Gd3+-sensitive pathway activated by reactive oxygen species and Na+/K+/2Cl- cotransport in neurons maintained for 6-10 and 11-14 d in vitro (DIV), respectively. Sodium entry immediately after anoxia was not attributable to the activation of ionotropic glutamate receptors, voltage-activated Na+ channels, or Na+/K+/2Cl- cotransport; rather, it occurred via Na+/Ca2+ exchange, Na+/H+ exchange, and a Gd3+-sensitive pathway similar to that observed during anoxia; 11-14 DIV neurons received an additional contribution from an -dependent mechanism(s). The results provide insight into the intrinsic mechanisms that contribute to disturbed internal Na+ homeostasis during and immediately after anoxia in rat hippocampal neurons and, in this way, may play a role in the pathogenesis of anoxic or ischemic cell injury.
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Affiliation(s)
- Claire Sheldon
- Department of Physiology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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Hamahata K, Adachi S, Matsubara H, Okada M, Imai T, Watanabe KI, Toyokuni SY, Ueno M, Wakabayashi S, Katanosaka Y, Akiba S, Kubota M, Nakahata T. Mitochondrial dysfunction is related to necrosis-like programmed cell death induced by A23187 in CEM cells. Eur J Pharmacol 2005; 516:187-96. [PMID: 15963976 DOI: 10.1016/j.ejphar.2005.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Accepted: 04/11/2005] [Indexed: 11/25/2022]
Abstract
We have previously reported that calcium ionophore A23187 differentially induces necrosis in CEM cells, a T-lymphoblastic leukemia cell line, and apoptosis in HL60 cells, a promyelocytic leukemia cell line. Stimulation with VP16, however, induces typical apoptosis in both cell lines. Necrosis in CEM cells, characterized by cell shrinkage and clustering, began within 5 min of treatment. Swelling of the mitochondria, lumpy chromatin condensation and intact plasma membranes were evident by electron microscopy. These A23187-mediated changes in CEM cells were suppressed by clonazepam or CGP37157, inhibitors of the mitochondrial Na(+)/Ca(2+) exchanger. The changes, however, were not affected by cyclosporin A, an inhibitor of the mitochondrial permeability transition pore. In both CEM and HL60 cells, intra-cellular calcium increased with similar amplitude within 1 min of treatment with 2 microM A23187. Intra-mitochondrial calcium increased with clonazepam pre-treatment alone in both CEM and HL60 cells. However, intra-mitochondrial calcium did not change drastically in response to A23187 in CEM or HL60 cells, either untreated or pre-treated with clonazepam. A23187 induces necrosis in CEM cells concurrent with mitochondrial dysfunction, which is independent of the mitochondrial permeability transition, but affected by intra-mitochondrial calcium, while HL60 cells lack these early changes. Differences in the responses to A23187 between these two cell lines might derive from differences in the susceptibility of the mitochondrial membrane to rapid increases in intra-cellular calcium.
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Affiliation(s)
- Keigo Hamahata
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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