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Belo do Nascimento I, Damblon J, Ingelbrecht C, Goursaud S, Massart M, Dumont A, Desmet N, Hermans E. Pharmacological evidence for the concept of spare glutamate transporters. Neurochem Int 2021; 149:105142. [PMID: 34314789 DOI: 10.1016/j.neuint.2021.105142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/09/2021] [Accepted: 07/22/2021] [Indexed: 01/30/2023]
Abstract
Through the efficient clearance of extracellular glutamate, high affinity astrocytic glutamate transporters constantly shape excitatory neurotransmission in terms of duration and spreading. Even though the glutamate transporter GLT-1 (also known as EAAT2/SLC1A2) is amongst the most abundant proteins in the mammalian brain, its density and activity are tightly regulated. In order to study the influence of changes in the expression of GLT-1 on glutamate uptake capacity, we have developed a model in HEK cells where the density of the transporter can be manipulated thanks to a tetracycline-inducible promoter. Exposing the cells to doxycycline concentration-dependently increased GLT-1 expression and substrate uptake velocity. However, beyond a certain level of induction, increasing the density of transporters at the cell surface failed to increase the maximal uptake. This suggested the progressive generation of a pool of spare transporters, a hypothesis that was further validated using the selective GLT-1 blocker WAY-213613 of which potency was influenced by the density of the transporters. The curve showing inhibition of uptake by increasing concentrations of WAY-213613 was indeed progressively rightward shifted when tested in cells where the transporter density was robustly induced. As largely documented in the context of cell-surface receptors, the existence of 'spare' glutamate transporters in the nervous tissue and particularly in astrocytes could impact on the consequences of physiological or pathological regulation of these transporters.
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Affiliation(s)
- Inês Belo do Nascimento
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Jonathan Damblon
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Caroline Ingelbrecht
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Stéphanie Goursaud
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Marion Massart
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Amélie Dumont
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Nathalie Desmet
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium
| | - Emmanuel Hermans
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200, Brussels, Belgium.
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Gallo A, Dimiziani A, Damblon J, Michot B, Des Rieux A, De Kock M, Hermans E, Deumens R. Modulation of spinal glial reactivity by intrathecal PPF is not sufficient to inhibit mechanical allodynia induced by nerve crush. Neurosci Res 2015; 95:78-82. [PMID: 25697394 DOI: 10.1016/j.neures.2015.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/29/2015] [Accepted: 02/07/2015] [Indexed: 12/16/2022]
Abstract
Spinal glial reactivity has been strongly implicated in pain that follows peripheral nerve injury. Among the many therapeutic agents that have been tested for anti-allodynia through immune modulation is the atypical methylxanthine propentofylline. While propentofylline shows a potent anti-allodynia effect after nerve transection injury, we here demonstrate that, when propentofylline is used intrathecally at the effective immune-modulatory dose, allodynia after rat nerve crush injury is completely preserved. Microglial/macrophage Iba-1 and astrocytic GFAP expression, increased in the dorsal horn of nerve crushed animals, was, however, effectively attenuated by propentofylline. Effective modulation of spinal glial reactivity is, thus, no assurance for anti-allodynia.
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Affiliation(s)
- Alessandro Gallo
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium
| | - Andrea Dimiziani
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium
| | - Jonathan Damblon
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium
| | - Benoît Michot
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium
| | - Anne Des Rieux
- Louvain Drug Research Institute, Pharmaceutics and Drug Delivery Unit, Avenue E. Mounier 73, 1200 Brussels, Belgium
| | - Marc De Kock
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium
| | - Emmanuel Hermans
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium
| | - Ronald Deumens
- Institute of Neuroscience, Université catholique de Louvain, Avenue Hippocrate B1.54.10, 1200 Brussels, Belgium.
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Bacq ZM, Damblon J, Herve A. [Radioresistance of a seaweed Acetabularia mediterranea Lamour]. C R Seances Soc Biol Fil 1955; 149:1512-5. [PMID: 13293904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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