1
|
Vandame D, Ulmann L, Teigell M, Prieto-Cappellini M, Vignon J, Privat A, Perez-Polo R, Nesic O, Hirbec H. Development of NMDAR antagonists with reduced neurotoxic side effects: a study on GK11. PLoS One 2013; 8:e81004. [PMID: 24260528 PMCID: PMC3834252 DOI: 10.1371/journal.pone.0081004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 10/09/2013] [Indexed: 12/25/2022] Open
Abstract
The NMDAR glutamate receptor subtype mediates various vital physiological neuronal functions. However, its excessive activation contributes to neuronal damage in a large variety of acute and chronic neurological disorders. NMDAR antagonists thus represent promising therapeutic tools that can counteract NMDARs' overactivation. Channel blockers are of special interest since they are use-dependent, thus being more potent at continuously activated NMDARs, as may be the case in pathological conditions. Nevertheless, it has been established that NMDAR antagonists, such as MK801, also have unacceptable neurotoxic effects. Presently only Memantine is considered a safe NMDAR antagonist and is used clinically. It has recently been speculated that antagonists that preferentially target extrasynaptic NMDARs would be less toxic. We previously demonstrated that the phencyclidine derivative GK11 preferentially inhibits extrasynaptic NMDARs. We thus anticipated that this compound would be safer than other known NMDAR antagonists. In this study we used whole-genome profiling of the rat cingulate cortex, a brain area that is particularly sensitive to NMDAR antagonists, to compare the potential adverse effects of GK11 and MK801. Our results showed that in contrast to GK11, the transcriptional profile of MK801 is characterized by a significant upregulation of inflammatory and stress-response genes, consistent with its high neurotoxicity. In addition, behavioural and immunohistochemical analyses confirmed marked inflammatory reactions (including astrogliosis and microglial activation) in MK801-treated, but not GK11-treated rats. Interestingly, we also showed that GK11 elicited less inflammation and neuronal damage, even when compared to Memantine, which like GK11, preferentially inhibits extrasynaptic NMDAR. As a whole, our study suggests that GK11 may be a more attractive therapeutic alternative in the treatment of CNS disorders characterized by the overactivation of glutamate receptors.
Collapse
Affiliation(s)
- Delphine Vandame
- INSERM, U1051, Institut de Neurosciences de Montpellier, Montpellier, France
| | - Lauriane Ulmann
- CNRS, UMR 5203, Institut de Génomique Fonctionnelle, Labex ICST, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 & 2, UMR5203, Montpellier, France
| | | | | | - Jacques Vignon
- INSERM, U1051, Institut de Neurosciences de Montpellier, Montpellier, France
| | - Alain Privat
- INSERM, U1051, Institut de Neurosciences de Montpellier, Montpellier, France
| | - Regino Perez-Polo
- Department of Biochemistry & Molecular Biology, UTMB, Galveston, Texas, United States of America
| | - Olivera Nesic
- Department of Biochemistry & Molecular Biology, UTMB, Galveston, Texas, United States of America
- Department of Medical Education, School of Medicine, El Paso, Texas, United States of America
| | - Helene Hirbec
- INSERM, U1051, Institut de Neurosciences de Montpellier, Montpellier, France
- CNRS, UMR 5203, Institut de Génomique Fonctionnelle, Labex ICST, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 & 2, UMR5203, Montpellier, France
| |
Collapse
|
2
|
Hirbec H, Kamenka JM, Privat A, Vignon J. Characterization of ‘non-N-methyl-d-Aspartate’ binding sites for gacyclidine enantiomers in the rat cerebellar and telencephalic structures. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.2001.00250.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
3
|
Vandame D, Desmadryl G, Becerril Ortega J, Teigell M, Crouzin N, Buisson A, Privat A, Hirbec H. Comparison of the pharmacological properties of GK11 and MK801, two NMDA receptor antagonists: towards an explanation for the lack of intrinsic neurotoxicity of GK11. J Neurochem 2007; 103:1682-96. [PMID: 17908242 DOI: 10.1111/j.1471-4159.2007.04925.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Over-stimulation of NMDA receptors (NMDARs) is involved in many neurodegenerative disorders. Thus, developing safe NMDAR antagonists is of high therapeutic interest. GK11 is a high affinity uncompetitive NMDAR antagonist with low intrinsic neurotoxicity, shown to be promising for treating CNS trauma. In the present study, we investigated the molecular basis of its interaction with NMDARs and compared this with the reference molecule MK801. We show, on primary cultures of hippocampal neurons, that GK11 exhibits neuroprotection properties similar to those of MK801, but in contrast with MK801, GK11 is not toxic to neurons. Using patch-clamp techniques, we also show that on NR1a/NR2B receptors, GK11 totally blocks the NMDA-mediated currents but has a six-fold lower IC(50) than MK801. On NR1a/NR2A receptors, it displays similar affinity but fails to totally prevent the currents. As NR2A is preferentially localized at synapses and NR2B at extrasynaptic sites, we investigated, using calcium imaging and patch-clamp approaches, the effects of GK11 on either synaptic or extrasynaptic NMDA-mediated responses. Here we demonstrate that in contrast with MK801, GK11 better preserve the synaptic NMDA-mediated currents. Our study supports that the selectivity of GK11 for NR2B containing receptors accounts contributes, at least partially, for its safer pharmacological profile.
Collapse
|
4
|
Giménez y Ribotta M, Gaviria M, Menet V, Privat A. Strategies for regeneration and repair in spinal cord traumatic injury. PROGRESS IN BRAIN RESEARCH 2002; 137:191-212. [PMID: 12440369 DOI: 10.1016/s0079-6123(02)37017-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Spinal cord injury is frequently followed by the loss of supraspinal control of sensory, autonomic and motor functions at the sublesional level. In order to enhance recovery in spinal cord-injured patients, we have developed three fundamental strategies in experimental models. These strategies define in turn three chronological levels of postlesional intervention in the spinal cord. Neuroprotection soon after injury using pharmacological tools to reduce the progressive secondary injury processes that follow during the first week after the initial lesion. This strategy was conducted up to clinical trials, showing that a pharmacological therapy can reduce the permanent neurological deficit that usually follows an acute injury of the central nervous system (CNS). A second strategy, which is initiated not long after the lesion, aims at promoting axonal regeneration by acting on the main barrier to regeneration of lesioned axons: the glial scar. Finally a mid-term substitutive strategy is the management of the sublesional spinal cord by sensorimotor stimulation and/or supply of missing key afferents, such as monoaminergic systems. These three strategies are reviewed. Only a combination of these different approaches will be able to provide an optimal basis for potential therapeutic interventions directed to functional recovery after spinal cord injury.
Collapse
|
5
|
Hirbec H, Gaviria M, Vignon J. Gacyclidine: a new neuroprotective agent acting at the N-methyl-D-aspartate receptor. CNS DRUG REVIEWS 2001. [PMID: 11474423 DOI: 10.1111/j.1527-3458.2001.tb00194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gacyclidine is a new phencyclidine derivative with neuroprotective properties. Tritiated gacyclidine and its enantiomers bind to NMDA receptors with binding parameters similar to those of other non-competitive NMDA receptor antagonists. The (-)enantiomer, (-)GK11, exhibits an affinity (2.5 nM) similar to that of dizocilpine (MK-801), while the (+)enantiomer, (+)GK11, has a 10 times lower affinity. When its interaction with NMDA receptors is prevented, gacyclidine binds also to "non-NMDA" binding sites which are mainly located in the molecular layer of the cerebellum on the dendritic tree of Purkinje cells. These binding sites do not appear to be related to any known neurotransmitters. In primary cortical cultures, gacyclidine and its enantiomers, at 0.1 to 5.0 microM, prevent glutamate-induced neuronal death. In rats, in vivo neurotoxicity of gacyclidine is far low than that of MK-801. No necrotic neurons were detected in animals sacrificed at 18 or 96 h after treatment with gacyclidine (1, 5, 10 or 20 mg/kg i.v.). At the highest (20 mg/kg) but not the lower doses (1-100 mg/kg) electron microscopy revealed the presence of few cytoplasmic or intramitochondrial vacuoles. In soman-treated monkeys gacyclidine enhanced neuroprotective activity of "three drugs cocktail" (atropine + diazepam + pralidoxime). Moreover, in rats, gacyclidine exerts a dose- and time-dependent neuroprotection in three models of spinal cord lesion. Beneficial effects of gacyclidine include reduction of lesion size and improvement of functional parameters after injury. In traumatic brain injury models gacyclidine improves also behavioral parameters and neuronal survival. Optimal protection is obtained when gacyclidine is administered at 0 to 30 min after injury. It is, therefore, concluded that gacyclidine exhibits neuroprotective effects similar to those of other NMDA receptor antagonists, with the advantage of being substantially less neurotoxic maybe due to its interaction with "non-NMDA" binding sites.
Collapse
Affiliation(s)
- H Hirbec
- INSERM U336, DPVSN, Institut de Biologie, 4 Boulevard Henri IV, F-34060 Montpellier, France
| | | | | |
Collapse
|
6
|
Hirbec H, Gaviria M, Vignon J. Gacyclidine: a new neuroprotective agent acting at the N-methyl-D-aspartate receptor. CNS DRUG REVIEWS 2001; 7:172-98. [PMID: 11474423 PMCID: PMC6741685 DOI: 10.1111/j.1527-3458.2001.tb00194.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gacyclidine is a new phencyclidine derivative with neuroprotective properties. Tritiated gacyclidine and its enantiomers bind to NMDA receptors with binding parameters similar to those of other non-competitive NMDA receptor antagonists. The (-)enantiomer, (-)GK11, exhibits an affinity (2.5 nM) similar to that of dizocilpine (MK-801), while the (+)enantiomer, (+)GK11, has a 10 times lower affinity. When its interaction with NMDA receptors is prevented, gacyclidine binds also to "non-NMDA" binding sites which are mainly located in the molecular layer of the cerebellum on the dendritic tree of Purkinje cells. These binding sites do not appear to be related to any known neurotransmitters. In primary cortical cultures, gacyclidine and its enantiomers, at 0.1 to 5.0 microM, prevent glutamate-induced neuronal death. In rats, in vivo neurotoxicity of gacyclidine is far low than that of MK-801. No necrotic neurons were detected in animals sacrificed at 18 or 96 h after treatment with gacyclidine (1, 5, 10 or 20 mg/kg i.v.). At the highest (20 mg/kg) but not the lower doses (1-100 mg/kg) electron microscopy revealed the presence of few cytoplasmic or intramitochondrial vacuoles. In soman-treated monkeys gacyclidine enhanced neuroprotective activity of "three drugs cocktail" (atropine + diazepam + pralidoxime). Moreover, in rats, gacyclidine exerts a dose- and time-dependent neuroprotection in three models of spinal cord lesion. Beneficial effects of gacyclidine include reduction of lesion size and improvement of functional parameters after injury. In traumatic brain injury models gacyclidine improves also behavioral parameters and neuronal survival. Optimal protection is obtained when gacyclidine is administered at 0 to 30 min after injury. It is, therefore, concluded that gacyclidine exhibits neuroprotective effects similar to those of other NMDA receptor antagonists, with the advantage of being substantially less neurotoxic maybe due to its interaction with "non-NMDA" binding sites.
Collapse
Affiliation(s)
- Hélène Hirbec
- INSERM U336, DPVSN, Institut de Biologie, Montpellier, France
| | | | - Jacques Vignon
- INSERM U336, DPVSN, Institut de Biologie, Montpellier, France
| |
Collapse
|
7
|
Feldblum S, Arnaud S, Simon M, Rabin O, D'Arbigny P. Efficacy of a new neuroprotective agent, gacyclidine, in a model of rat spinal cord injury. J Neurotrauma 2000; 17:1079-93. [PMID: 11101210 DOI: 10.1089/neu.2000.17.1079] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Prevention of the immediate excitotoxic phase occurring in response to spinal cord injury (SCI) is a major issue to reduce the neuronal damage responsible for any ensuing motor deficits. The present study evaluated the neuroprotective efficacy of three noncompetitive NMDA receptor antagonists: Gacyclidine (GK-11), a new compound, Dizocilpine (MK-801), and Cerestat (CNS-1102) in a rat spinal cord contusion model. To mimic human SCI, a standardized model of rat spinal cord closed contusion in which animals spontaneously and progressively recover from the induced paraplegia was employed. Such model, characterized by a slow recovery of hindlimb locomotor function enables easy quantification of the neuroprotection at both the behavioral and cellular level. The animals were treated intravenously with the respective drugs 10 min after the spinal contusion. The dose range study suggested that 1 mg/kg of Gacyclidine was the most effective dose to promote functional recovery in reducing by half the time needed to reach full locomotor recovery. Racemate and enantiomers of Gacyclidine showed similar neuroprotective effects, but treatment with the enantiomers were not as efficacious in promoting full functional recovery. Similarly, a prolonged treatment with the racemate was not as efficious as a single dose, suggesting that a prolonged blockade of the amino-excitatory neurotransmission may be deleterious. Finally, Dizocilpine and Cerestat treatments induced only a partial and delayed neuroprotective effect compared to Gacyclidine. Neuroprotection characterized by a reduction of the cystic cavity and of the astrogliosis was observed with all treatments. As Gacyclidine is already in clinical trials, the present findings suggest the premise that it is a promising agent for limiting the initial neuronal damage induced by CNS trauma leading to better functional recovery.
Collapse
Affiliation(s)
- S Feldblum
- Neurolab, Biological Research Laboratory, Paris, France.
| | | | | | | | | |
Collapse
|
8
|
Laplanche L, Kamenka JM, Barbanel G. The novel non-competitive N-methyl-D-aspartate antagonist gacyclidine blocks the glutamate-induced release of hydroxyl radicals in the striatum under conditions in which dizocilpine does not. A microdialysis study in rats. Neurosci Lett 2000; 289:49-52. [PMID: 10899406 DOI: 10.1016/s0304-3940(00)01259-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Gacyclidine, a new neuroprotectant aimed to non-competitively antagonize N-methyl-D-aspartate (NMDA) receptors, and dizocilpine blocked the hydroxyl radical response to toxic amounts of glutamate, perfused through a microdialysis implanted in the striatum of conscious rats. Furthermore, the hydroxyl radical response resulting from the infusion of lower doses of glutamate, which could not be inhibited by the same amounts of dizocilpine nor by acute alcohol exposure, still remained sensitive to gacyclidine inhibition. Thus, oxidative stress resulting from a glutamate discharge involves the activation of both NMDA receptors, and of non-NMDA mechanism(s) which, with moderate glutamate levels, were still antagonized by gacyclidine. Enhanced blockage of toxic hydroxyl radicals might explain the different and possibly higher neuroprotective property of gacyclidine as compared with other non-competitive NMDA antagonists.
Collapse
Affiliation(s)
- L Laplanche
- CRBM, CNRS UPR 1086, Ecole Nationale Supérieure de Chimie de, Montpellier, France
| | | | | |
Collapse
|