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Pirio Richardson S, Jinnah HA. New approaches to discovering drugs that treat dystonia. Expert Opin Drug Discov 2019; 14:893-900. [PMID: 31159587 DOI: 10.1080/17460441.2019.1623785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Dystonia consists of involuntary movements, abnormal posturing, and pain. In adults, dystonia presents in a particular region of the body and causes significant disability due to pain as well as impairment in activities of daily living and employment. The current gold standard treatment, botulinum toxin (BoNT), has limitations - painful, frequent injections due to 'wearing off' of treatment effect; expense; and expected side effects like swallowing difficulty and weakness. There is a clear therapeutic gap in our current treatment options for dystonia and also a clear need for an effective novel treatment. Testing any novel treatment is complicated because most adults with focal dystonia are treated with BoNT. Areas covered: This review focuses on establishing the need for novel therapeutics. It also suggests potential leads from preclinical studies; and, discusses the issue of clinical trial readiness in the dystonia field. Expert opinion: Identifying a novel therapeutic intervention for dystonia patients faces two major challenges. The first is acknowledging the therapeutic gap that currently exists. Second, shifting some of our research aims in dystonia to clinical trial readiness is imperative if we are to be ready to test novel therapeutic agents.
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Affiliation(s)
- Sarah Pirio Richardson
- a Department of Neurology, University of New Mexico Health Sciences Center , Albuquerque , NM , USA.,b Neurology Service, New Mexico Veterans Affairs Health Care System , Albuquerque , NM , USA
| | - H A Jinnah
- c Departments of Neurology, Human Genetics & Pediatrics, Emory University School of Medicine , Atlanta , Georgia
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2
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Pourmirbabaei S, Dolatshahi M, Rahmani F. Pathophysiological clues to therapeutic applications of glutamate mGlu5 receptor antagonists in levodopa-induced dyskinesia. Eur J Pharmacol 2019; 855:149-159. [PMID: 31063776 DOI: 10.1016/j.ejphar.2019.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/29/2019] [Accepted: 05/03/2019] [Indexed: 12/16/2022]
Abstract
Levodopa remains to be the mainstay for treatment of Parkinson disease (PD). Long-term levodopa treatment bears a risk for developing levodopa-induced dyskinesia (LID). LID significantly overshadows patients' quality of life and therapeutic efficacy of levodopa. Pre- and post-synaptic changes in dopamine secretion and signaling, along with altered glutamate receptor expression and glutamatergic signaling in striatal neurons, and the resulting disinhibition-like changes in the corticostriatal circuitry, lead to aberrant activity of motor cortex and formation of LID. Research has highlighted the role of group I metabotropic glutamate receptors especially the metabotropic glutamate receptor 5 (mGlu5) in formation of LID through potentiating of ionotropic glutamate NMDA receptors and dopamine D1/D5 receptors in direct pathway. Accordingly, MTEP and MPEP were the first mGlu5 receptor antagonists which were shown to attenuate LID in animal models through suppression of downstream signaling cascades involving mitogen-activated protein kinase (MAPK) and FosB/delta FosB activation, as well as modulation of prodynorphinegic, preproenkephalinergic, and GABA-ergic neurotransmission systems. Beneficial effects of other mGlu5 receptor antagonists such as AFQ056/mavoglurant and ADX48621/dipraglurant in amelioration of LID has been shown not only in animal models but also in clinical trials. Considering the presence of mGlu receptor dysregulation in rapid eye movement (REM) sleep behavior disorder and depression, which are prodromal signs of PD, along with the neuroprotective effects of mGlu receptor antagonists, and their cognitive benefits, potential effectiveness of mGlu receptor antagonists in early prevention of PD remains to be investigated.
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Affiliation(s)
- Shayan Pourmirbabaei
- Student's Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Mahsa Dolatshahi
- Student's Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Farzaneh Rahmani
- Student's Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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Mellone M, Gardoni F. Glutamatergic mechanisms in l-DOPA-induced dyskinesia and therapeutic implications. J Neural Transm (Vienna) 2018; 125:1225-1236. [DOI: 10.1007/s00702-018-1846-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 01/23/2018] [Indexed: 02/01/2023]
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Antidyskinetic Treatment with MTEP Affects Multiple Molecular Pathways in the Parkinsonian Striatum. PARKINSONS DISEASE 2017; 2017:5798734. [PMID: 29209553 PMCID: PMC5682907 DOI: 10.1155/2017/5798734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/08/2017] [Accepted: 09/17/2017] [Indexed: 01/02/2023]
Abstract
Parkinson's disease is characterized by dopaminergic neuron loss and dopamine (DA) depletion in the striatum. Standard treatment is still focused on the restoration of dopamine with exogenous L-Dopa, which however causes L-Dopa-induced dyskinesia (LID). Several studies have shown that antagonism of the metabotropic glutamate receptor 5 alleviates LID, but the underlying mechanisms have remained unclear. We set out to determine where this alleviation may depend on restoring the equilibrium between the two main striatofugal pathways. For this purpose, we examined molecular markers of direct and indirect pathway involvement (prodynorphin and proenkephalin, resp.) in a rat model of LID treated with the mGluR5 antagonist MTEP. Our results show that MTEP cotreatment significantly attenuates the upregulation of prodynorphin mRNA induced by L-Dopa while also decreasing the expression levels of proenkephalin mRNA. We also examined markers of the mGluR5-related PKC/MEK/ERK1/2 signaling pathway, finding that both the expression of PKC epsilon and the phosphorylation of MEK and ERK1/2 had decreased significantly in the MTEP-treated group. Taken together, our results show that pharmacological antagonism of mGluR5 normalizes several abnormal molecular responses in the striatum in this experimental model of LID.
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Nishijima H, Ueno T, Funamizu Y, Ueno S, Tomiyama M. Levodopa treatment and dendritic spine pathology. Mov Disord 2017; 33:877-888. [PMID: 28880414 PMCID: PMC6667906 DOI: 10.1002/mds.27172] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/13/2017] [Accepted: 08/14/2017] [Indexed: 12/20/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder associated with the progressive loss of nigrostriatal dopaminergic neurons. Levodopa is the most effective treatment for the motor symptoms of PD. However, chronic oral levodopa treatment can lead to various motor and nonmotor complications because of nonphysiological pulsatile dopaminergic stimulation in the brain. Examinations of autopsy cases with PD have revealed a decreased number of dendritic spines of striatal neurons. Animal models of PD have revealed altered density and morphology of dendritic spines of neurons in various brain regions after dopaminergic denervation or dopaminergic denervation plus levodopa treatment, indicating altered synaptic transmission. Recent studies using rodent models have reported dendritic spine head enlargement in the caudate‐putamen, nucleus accumbens, primary motor cortex, and prefrontal cortex in cases where chronic levodopa treatment following dopaminergic denervation induced dyskinesia‐like abnormal involuntary movement. Hypertrophy of spines results from insertion of alpha‐amino‐2,3‐dihydro‐5‐methyl‐3‐oxo‐4‐isoxazolepropanoic acid receptors into the postsynaptic membrane. Such spine enlargement indicates hypersensitivity of the synapse to excitatory inputs and is compatible with a lack of depotentiation, which is an electrophysiological hallmark of levodopa‐induced dyskinesia found in the corticostriatal synapses of dyskinetic animals and the motor cortex of dyskinetic PD patients. This synaptic plasticity may be one of the mechanisms underlying the priming of levodopa‐induced complications such as levodopa‐induced dyskinesia and dopamine dysregulation syndrome. Drugs that could potentially prevent spine enlargement, such as calcium channel blockers, N‐methyl‐D‐aspartate receptor antagonists, alpha‐amino‐2,3‐dihydro‐5‐methyl‐3‐oxo‐4‐isoxazolepropanoic acid receptor antagonists, and metabotropic glutamate receptor antagonists, are candidates for treatment of levodopa‐induced complications in PD. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Haruo Nishijima
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan.,Department of Neurophysiology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Tatsuya Ueno
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan.,Department of Neurophysiology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Yukihisa Funamizu
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan
| | - Shinya Ueno
- Department of Neurophysiology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Masahiko Tomiyama
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan.,Department of Neurophysiology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
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Cerri S, Siani F, Blandini F. Investigational drugs in Phase I and Phase II for Levodopa-induced dyskinesias. Expert Opin Investig Drugs 2017; 26:777-791. [PMID: 28535734 DOI: 10.1080/13543784.2017.1333598] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Prolonged treatment of Parkinson's disease (PD) with levodopa (L-DOPA) results in motor complications, including motor fluctuations and involuntary movements known as L-DOPA induced dyskinesias (LIDs). LIDs represent an additional cause of disability for PD patients and a major challenge for the clinical neurologist. Preclinical research has provided invaluable insights into the molecular and neural substrates of LIDs, identifying a number of potential targets for new anti-dyskinetic strategies. Areas covered: This review article is centered on drugs currently in Phase I and II clinical trials for LIDs and their relative pharmacological targets, which include glutamate, acetylcholine, serotonin, adrenergic receptors and additional targets of potential therapeutic interest. Expert opinion: LIDs are sustained by complex molecular and neurobiological mechanisms that are difficult to disentangle or target, unless one or more prevalent mechanisms are identified. In this context, the role of the serotonergic system and mGluR5 glutamate receptors seem to stand out. Interesting results have been obtained, for example, with partial 5-HT1A/5-HT1B receptor agonist eltoprazine and mGluR5 negative allosteric modulator dipraglurant. Confirmation of these results through large-scale, Phase III clinical trials will be needed, to obtain new pharmacological tools that may be used to optimize the treatment of PD patients with motor complications.
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Affiliation(s)
- Silvia Cerri
- a Laboratory of Functional Neurochemistry, Center for Research in Neurodegenerative Diseases , C. Mondino National Neurological Institute , Pavia , Italy
| | - Francesca Siani
- a Laboratory of Functional Neurochemistry, Center for Research in Neurodegenerative Diseases , C. Mondino National Neurological Institute , Pavia , Italy
| | - Fabio Blandini
- a Laboratory of Functional Neurochemistry, Center for Research in Neurodegenerative Diseases , C. Mondino National Neurological Institute , Pavia , Italy
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Yin SB, Zhang XG, Chen S, Yang WT, Zheng XW, Zheng GQ. Adenosine A 2A Receptor Gene Knockout Prevents l-3,4-Dihydroxyphenylalanine-Induced Dyskinesia by Downregulation of Striatal GAD67 in 6-OHDA-Lesioned Parkinson's Mice. Front Neurol 2017; 8:88. [PMID: 28377741 PMCID: PMC5359221 DOI: 10.3389/fneur.2017.00088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/24/2017] [Indexed: 11/29/2022] Open
Abstract
l-3,4-Dihydroxyphenylalanine (l-DOPA) remains the primary pharmacological agent for the symptomatic treatment of Parkinson’s disease (PD). However, the development of l-DOPA-induced dyskinesia (LID) limits the long-term use of l-DOPA for PD patients. Some data have reported that adenosine A2A receptor (A2AR) antagonists prevented LID in animal model of PD. However, the mechanism in which adenosine A2AR blockade alleviates the symptoms of LID has not been fully clarified. Here, we determined to knock out (KO) the gene of A2AR and explored the possible underlying mechanisms implicated in development of LID in a mouse model of PD. A2AR gene KO mice were unilaterally injected into the striatum with 6-hydroxydopamine (6-OHDA) in order to damage dopamine neurons on one side of the brain. 6-OHDA-lesioned mice were then injected once daily for 21 days with l-DOPA. Abnormal involuntary movements (AIMs) were evaluated on days 3, 8, 13, and 18 after l-DOPA administration, and real-time polymerase chain reaction and immunohistochemistry for glutamic acid decarboxylase (GAD) 65 and GAD67 were performed. We found that A2AR gene KO was effective in reducing AIM scores and accompanied with decrease of striatal GAD67, rather than GAD65. These results demonstrated that the possible mechanism involved in alleviation of AIM symptoms by A2AR gene KO might be through reducing the expression of striatal GAD67.
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Affiliation(s)
- Su-Bing Yin
- Department of Neurology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , China
| | - Xiao-Guang Zhang
- Department of Neurology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , China
| | - Shuang Chen
- Department of Neurology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , China
| | - Wen-Ting Yang
- Department of Neurology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , China
| | - Xia-Wei Zheng
- Department of Neurology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , China
| | - Guo-Qing Zheng
- Department of Neurology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou , China
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Morin N, Morissette M, Grégoire L, Di Paolo T. mGlu5, Dopamine D2 and Adenosine A2A Receptors in L-DOPA-induced Dyskinesias. Curr Neuropharmacol 2017; 14:481-93. [PMID: 26639458 PMCID: PMC4983750 DOI: 10.2174/1570159x14666151201185652] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 11/04/2015] [Accepted: 11/11/2015] [Indexed: 02/07/2023] Open
Abstract
Patients with Parkinson's disease (PD) receiving L-3,4-dihydroxyphenylalanine (L-DOPA, the gold-standard treatment for this disease) frequently develop abnormal involuntary movements, termed L-DOPA-induced dyskinesias (LID). Glutamate overactivity is well documented in PD and LID. An approach to manage LID is to add to L-DOPA specific agents to reduce dyskinesias such as metabotropic glutamate receptor (mGlu receptor) drugs. This article reviews the contribution of mGlu type 5 (mGlu5) receptors in animal models of PD. Several mGlu5 negative allosteric modulators acutely attenuate LID in 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) monkeys and 6-hydroxydopamine(6-OHDA)-lesioned rats. Chronic administration of mGlu5 negative allosteric modulators to MPTP monkeys and 6-OHDA rats also attenuates LID while maintaining the antiparkinsonian effect of L-DOPA. Radioligand autoradiography shows an elevation of striatal mGlu5 receptors of dyskinetic L-DOPA-treated MPTP monkeys but not in those without LID. The brain molecular correlates of the long-term effect of mGlu5 negative allosteric modulators treatments with L-DOPA attenuating development of LID was shown to extend beyond mGlu5 receptors with normalization of glutamate activity in the basal ganglia of L-DOPA-induced changes of NMDA, AMPA, mGlu2/3 receptors and VGlut2 transporter. In the basal ganglia, mGlu5 receptor negative allosteric modulators also normalize the L-DOPA-induced changes of dopamine D2receptors, their associated signaling proteins (ERK1/2 and Akt/GSK3β) and neuropeptides (preproenkephalin, preprodynorphin) as well as the adenosine A2A receptors expression. These results show in animal models of PD reduction of LID with mGlu5 negative allosteric modulation associated with normalization of glutamate, dopamine and adenosine receptors suggesting a functional link of these receptors in chronic treatment with L-DOPA.
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Affiliation(s)
| | | | | | - Thérèse Di Paolo
- Neuroscience Research Unit, Centre de recherche du CHU de Québec, 2705 Laurier Boulevard, Quebec, Qc, Canada, G1V 4G2.
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Zhang K, Chammas C, Soghomonian JJ. Loss of glutamic acid decarboxylase (Gad67) in striatal neurons expressing the Drdr1a dopamine receptor prevents l-DOPA-induced dyskinesia in 6-hydroxydopamine-lesioned mice. Neuroscience 2015; 303:586-94. [DOI: 10.1016/j.neuroscience.2015.07.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 07/08/2015] [Accepted: 07/10/2015] [Indexed: 01/29/2023]
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Neurobiology of l-DOPA induced dyskinesia and the novel therapeutic strategies. Biomed Pharmacother 2015; 70:283-93. [DOI: 10.1016/j.biopha.2015.01.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 01/23/2015] [Indexed: 12/27/2022] Open
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Rascol O, Fox S, Gasparini F, Kenney C, Di Paolo T, Gomez-Mancilla B. Use of metabotropic glutamate 5-receptor antagonists for treatment of levodopa-induced dyskinesias. Parkinsonism Relat Disord 2014; 20:947-56. [DOI: 10.1016/j.parkreldis.2014.05.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/02/2014] [Accepted: 05/02/2014] [Indexed: 10/25/2022]
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12
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Bezard E, Pioli EY, Li Q, Girard F, Mutel V, Keywood C, Tison F, Rascol O, Poli SM. The mGluR5 negative allosteric modulator dipraglurant reduces dyskinesia in the MPTP macaque model. Mov Disord 2014; 29:1074-9. [DOI: 10.1002/mds.25920] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/08/2014] [Accepted: 04/21/2014] [Indexed: 11/08/2022] Open
Affiliation(s)
- Erwan Bezard
- Motac neuroscience; Manchester UK
- Université de Bordeaux; Institut des Maladies Neurodégénératives, UMR 5293; Bordeaux France
- CNRS; Institut des Maladies Neurodégénératives, UMR 5293; Bordeaux France
- Service de Neurologie; CHU de Bordeaux; Pessac France
- Institute of Laboratory Animal Sciences; China Academy of Medical Sciences; Beijing China
| | | | - Qin Li
- Motac neuroscience; Manchester UK
- Institute of Laboratory Animal Sciences; China Academy of Medical Sciences; Beijing China
| | | | | | | | - Francois Tison
- Université de Bordeaux; Institut des Maladies Neurodégénératives, UMR 5293; Bordeaux France
- CNRS; Institut des Maladies Neurodégénératives, UMR 5293; Bordeaux France
- Service de Neurologie; CHU de Bordeaux; Pessac France
| | - Olivier Rascol
- CIC Toulouse; France
- Départements de Pharmacologie Clinique et Neurosciences; INSERM CIC9302; CHU de Toulouse France
- Service de Pharmacologie; Faculté de Médecine, CHU de Toulouse, Université de Toulouse; France
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Finlay C, Duty S. Therapeutic potential of targeting glutamate receptors in Parkinson's disease. J Neural Transm (Vienna) 2014; 121:861-80. [PMID: 24557498 DOI: 10.1007/s00702-014-1176-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/05/2014] [Indexed: 12/28/2022]
Abstract
Glutamate plays a complex role in many aspects of Parkinson's disease including the loss of dopaminergic neurons, the classical motor symptoms as well as associated non-motor symptoms and the treatment-related side effect, L-DOPA-induced dyskinesia. This widespread involvement opens up possibilities for glutamate-based therapies to provide a more rounded approach to treatment than is afforded by current dopamine replacement therapies. Beneficial effects of blocking postsynaptic glutamate transmission have already been noted in a range of preclinical studies using antagonists of NMDA receptors or negative allosteric modulators of metabotropic glutamate receptor 5 (mGlu5), while positive allosteric modulators of mGlu4 in particular, although at an earlier stage of investigation, also look promising. This review addresses each of the key features of Parkinson's disease in turn, summarising the contribution glutamate makes to that feature and presenting an up-to-date account of the potential for drugs acting at ionotropic or metabotropic glutamate receptors to provide relief. Whilst only a handful of these have progressed to clinical trials to date, notably NMDA and NR2B antagonists against motor symptoms and L-DOPA-induced dyskinesia, with mGlu5 negative allosteric modulators also against L-DOPA-induced dyskinesia, the mainly positive outcomes of these trials, coupled with supportive preclinical data for other strategies in animal models of Parkinson's disease and L-DOPA-induced dyskinesia, raise cautious optimism that a glutamate-based therapeutic approach will have significant impact on the treatment of Parkinson's disease.
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Affiliation(s)
- Clare Finlay
- Wolfson Centre for Age-Related Diseases, King's College London, WW1.28. Hodgkin Building, Guy's Campus, London, SE1 1UL, UK
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14
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Morin N, Jourdain VA, Morissette M, Grégoire L, Di Paolo T. Long-term treatment with l-DOPA and an mGlu5 receptor antagonist prevents changes in brain basal ganglia dopamine receptors, their associated signaling proteins and neuropeptides in parkinsonian monkeys. Neuropharmacology 2014; 79:688-706. [PMID: 24456747 DOI: 10.1016/j.neuropharm.2014.01.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/11/2013] [Accepted: 01/07/2014] [Indexed: 01/11/2023]
Abstract
Brain glutamate overactivity is well documented in Parkinson's disease (PD) and antiglutamatergic drugs decrease L-3,4-dihydroxyphenylalanine (l-DOPA)-induced dyskinesias (LID); the implication of dopamine neurotransmission is not documented in this anti-LID activity. Therefore, we evaluated changes of dopamine receptors, their associated signaling proteins and neuropeptides mRNA, in normal control monkeys, in saline-treated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys and in L-DOPA-treated MPTP monkeys, without or with an adjunct treatment to reduce the development of LID: 2-methyl-6-(phenylethynyl)pyridine (MPEP), the prototypal metabotropic glutamate 5 (mGlu5) receptor antagonist. All de novo treatments were administered for 1 month and the animals were sacrificed thereafter. MPTP monkeys treated with l-DOPA + MPEP developed significantly less LID than MPTP monkeys treated with l-DOPA alone. [(3)H]SCH-23390 specific binding to D1 receptors of all MPTP monkeys was decreased as compared to controls in the basal ganglia and no difference was observed between all MPTP groups, while striatal D1 receptor mRNA levels remained unchanged. [(3)H]raclopride specific binding to striatal D2 receptors and mRNA levels of D2 receptors were increased in MPTP monkeys compared to controls; l-DOPA treatment reduced this binding in MPTP monkeys while it remained elevated with the l-DOPA + MPEP treatment. Striatal [(3)H]raclopride specific binding correlated positively with D2 receptor mRNA levels of all MPTP-lesioned monkeys. Striatal preproenkephalin/preprodynorphin mRNA levels and phosphorylated ERK1/2 and Akt/GSK3β levels increased only in L-DOPA-treated MPTP monkeys as compared to controls, saline treated-MPTP and l-DOPA + MPEP treated MPTP monkeys. Hence, reduction of development of LID with MPEP was associated with changes in D2 receptors, their associated signaling proteins and neuropeptides.
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Affiliation(s)
- Nicolas Morin
- Faculty of Pharmacy, Université Laval, Quebec City G1K 7P4, Canada; Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Vincent A Jourdain
- Faculty of Pharmacy, Université Laval, Quebec City G1K 7P4, Canada; Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Marc Morissette
- Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Laurent Grégoire
- Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Thérèse Di Paolo
- Faculty of Pharmacy, Université Laval, Quebec City G1K 7P4, Canada; Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada.
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Morin N, Morissette M, Grégoire L, Gomez-Mancilla B, Gasparini F, Di Paolo T. Chronic treatment with MPEP, an mGlu5 receptor antagonist, normalizes basal ganglia glutamate neurotransmission in L-DOPA-treated parkinsonian monkeys. Neuropharmacology 2013; 73:216-31. [PMID: 23756168 DOI: 10.1016/j.neuropharm.2013.05.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 05/17/2013] [Accepted: 05/18/2013] [Indexed: 10/26/2022]
Abstract
Metabotropic glutamate 5 (mGlu5) receptor antagonists reduce L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesias (LID) in Parkinson's disease (PD). The aim of this study was to investigate the long-term effect of the prototypal mGlu5 receptor antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) on glutamate receptors known to be involved in the development of LID in the de novo chronic treatment of monkeys lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP monkeys were treated for one month with L-DOPA and developed dyskinesias while those treated with L-DOPA and MPEP (10 mg/kg) developed significantly less. Normal control and saline-treated MPTP monkeys were also included. All MPTP monkeys were extensively and similarly denervated. The basal ganglia [(3)H]ABP688 specific binding (mGlu5 receptors) was elevated in L-DOPA-treated MPTP monkeys compared to controls but not in those treated with L-DOPA and MPEP; dyskinesia scores of these monkeys correlated positively with their [(3)H]ABP688 specific binding. Striatal density (B(max)) of [(3)H]ABP688 specific binding increased in L-DOPA-treated MPTP monkeys compared to other groups and affinity (Kd) remained unchanged. Striatal mGlu5 receptor mRNA remained unchanged following treatments. Elevated basal ganglia specific binding of [(3)H]Ro 25-6981 (NMDA NR1/NR2B receptors), [(3)H]Ro 48-8587 (AMPA receptors) but not [(3)H]CGP-39653 (NMDA NR1/NR2A receptors) was observed only in L-DOPA-treated MPTP monkeys; dyskinesias scores correlated with binding. By contrast, basal ganglia [(3)H]LY341495 specific binding (mGlu2/3 receptors) decreased in L-DOPA-treated MPTP monkeys compared to controls, saline and L-DOPA + MPEP treated MPTP monkeys; dyskinesias scores correlated negatively with this binding. Hence, chronic MPEP treatment reduces the development of LID and is associated with a normalization of glutamate neurotransmission.
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Affiliation(s)
- Nicolas Morin
- Neuroscience Research Unit, Laval University Medical Center (CHUQ), Quebec, QC, Canada
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Targeting glutamate receptors to tackle the pathogenesis, clinical symptoms and levodopa-induced dyskinesia associated with Parkinson's disease. CNS Drugs 2012; 26:1017-32. [PMID: 23114872 DOI: 10.1007/s40263-012-0016-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The appearance of levodopa-induced dyskinesia (LID) and ongoing degeneration of nigrostriatal dopaminergic neurons are two key features of Parkinson's disease (PD) that current treatments fail to address. Increased glutamate transmission contributes to the motor symptoms in PD, to the striatal plasticity that underpins LID and to the progression of neurodegeneration through excitotoxic mechanisms. Glutamate receptors have therefore long been considered as potential targets for pharmacological intervention in PD, with emphasis on either blocking activation of 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid (AMPA), N-methyl-D-aspartate (NMDA) or excitatory metabotropic glutamate (mGlu) 5 receptors or promoting the activation of group II/III mGlu receptors. Following a brief summary of the role of glutamate in PD and LID, this article explores the current status of pharmacological studies in pre-clinical rodent and primate models through to clinical trials, where applicable, that support the potential of glutamate-based therapeutic interventions. To date, AMPA antagonists have shown good efficacy against LID in rat and primate models, but the failure of perampanel to lessen LID in clinical trials casts doubt on the translational potential of this approach. In contrast, antagonists selective for NR2B-containing NMDA receptors were effective against LID in animal models and in small-scale clinical trials, though observed adverse cognitive effects need addressing. So far, mGlu5 antagonists or negative allosteric modulators (NAMs) look set to become the first introduced for tackling LID, with AFQ-056 reported to exhibit good efficacy in phase II clinical trials. NR2B antagonists and mGlu5 NAMs may subsequently prove to also be effective disease-modifying agents if their protective effects in rat and primate models of PD, respectively, are replicated in the next stages of investigation. Finally, group III mGlu4 agonists or positive allosteric modulators (PAMs), although in the early pre-clinical stages of investigation, are showing good efficacy against motor symptoms, neurodegeneration and LID. It is anticipated that the recent development of mGlu4 PAMs with improved systemic bioavailability will facilitate progression of these agents into the primate model of PD where their potential can be further explored.
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Yang X, Chen Y, Hong X, Wu N, Song L, Yuan W, Liu Z. Levodopa/benserazide microspheres reduced levodopa-induced dyskinesia by downregulating phosphorylated GluR1 expression in 6-OHDA-lesioned rats. DRUG DESIGN DEVELOPMENT AND THERAPY 2012. [PMID: 23185117 PMCID: PMC3506046 DOI: 10.2147/dddt.s38008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Background Levodopa is the gold standard in the treatment of Parkinson’s disease (PD). However, long-term levodopa replacement therapy is accompanied by abnormal involuntary movements (AIMs), known as levodopa-induced dyskinesia (LID). Until now, the precise mechanisms of LID were only partially understood. Previous studies have shown that continuous dopamine stimulation was helpful in reducing the expression of LID. In addition to dopamine D1 receptor, glutamatergic receptors such as α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor also contribute to the expression of LID. The current authors have previously reported that levodopa/benserazide-loaded microspheres could ameliorate the expression of LID by reducing the protein kinase A signaling pathway in dyskinetic rats. However, whether AMPA receptor is involved in the mechanism by which levodopa/benserazide-loaded microspheres ameliorate the expression of LID in dyskinetic rats was unknown. Methods In the present study, as reported previously, levodopa and benserazide were loaded by poly(lactic-co-glycolic acid) microspheres, which can release levodopa and benserazide in a sustained manner. 6-Hydroxydopamine was injected into the right medial forebrain bundle to produce a rat model of PD. Then valid PD rats were treated with levodopa plus benserazide for 3 weeks to induce a rat model of LID. Dyskinetic rats were treated with levodopa/beserazide-loaded microspheres containing levodopa (6 mg/kg) plus benserazide (15 mg/kg) or same dose of levodopa plus benserazide. Abnormal involuntary movements were measured in rats on days 1, 5, 10, 15, and 20 during the treatment. The levels of GluR1 at serine-831 (pGluR1S831) and serine-845 (pGluR1S845) were determined by Western blot. Arc and proenkephalin (Penk) levels were measured by real-time polymerase chain reaction. Results Three-week levodopa plus benserazide treatment induced dyskinesia in PD rats. Levodopa/benserazide-loaded microsphere-treated dyskinetic rats showed lower AIM scores than levodopa plus benserazide-treated dyskinetic rats. Microsphere treatment downregulated the phosphrylated levels of pGluR1S831 and pGluR1S845 in the striatum of dyskinetic rats. In addition, microsphere treatment reduced the levels of Arc and Penk. Conclusion These data indicated that levodopa/benserazide-loaded microspheres could be used to ameliorate the expression of LID by reducing the expression of pGluR1S831 and pGluR1S845 as well as Arc and Penk.
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Affiliation(s)
- Xinxin Yang
- Department of Neurology, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
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Morin N, Grégoire L, Morissette M, Desrayaud S, Gomez-Mancilla B, Gasparini F, Di Paolo T. MPEP, an mGlu5 receptor antagonist, reduces the development of L-DOPA-induced motor complications in de novo parkinsonian monkeys: biochemical correlates. Neuropharmacology 2012; 66:355-64. [PMID: 22884464 DOI: 10.1016/j.neuropharm.2012.07.036] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 07/06/2012] [Accepted: 07/09/2012] [Indexed: 10/28/2022]
Abstract
L-3,4-Dihydroxyphenylalanine (l-DOPA), the gold standard therapy for Parkinson disease (PD), is associated with motor fluctuations and dyskinesias. This study sought to prevent the development of l-DOPA-induced dyskinesias (LID) with the metabotropic glutamate receptor type 5 (mGlu5 receptor) antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) in the de novo treatment of monkeys lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as a PD model. MPTP-lesioned monkeys were treated once daily for one month with either l-DOPA or l-DOPA + MPEP (10 mg/kg). MPEP (administered 15 min before l-DOPA) plasma concentrations were elevated during all the l-DOPA motor activation and did not accumulate during a month. The antiparkinsonian effect was maintained throughout the treatment period in MPTP-lesioned monkeys treated with l-DOPA + MPEP, while the duration of this effect decreased over time in MPTP-lesioned monkeys treated with l-DOPA alone, suggesting wearing-off. Over the month-long treatment, the mean dyskinesia score increased in l-DOPA-treated monkeys; interestingly, this increase was reduced by overall 72% in the l-DOPA + MPEP group. Mean dyskinesia scores of monkeys correlated inversely with plasma MPEP concentrations. Normal control and saline-treated MPTP-lesioned monkeys were also included for biochemical analyses. All MPTP-lesioned monkeys were extensively and similarly denervated. [(3)H]ABP688 specific binding to mGlu5 receptors increased in the putamen of l-DOPA-treated monkeys compared to control, saline or l-DOPA + MPEP-treated monkeys. Mean dyskinesia scores of MPTP-lesioned monkeys correlated positively with [(3)H]ABP688 specific binding in the putamen. This study showed a beneficial chronic antidyskinetic effect of MPEP in de novol-DOPA-treated MPTP-lesioned monkeys, supporting the therapeutic use of mGlu5 receptor antagonists in PD to prevent LID. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Affiliation(s)
- Nicolas Morin
- Molecular Endocrinology and Genomic Research Center, Laval University Medical Center (CHUQ), Quebec, QC, Canada
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Roles of group I metabotropic glutamate receptors under physiological conditions and in neurodegeneration. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/wmts.51] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Yang X, Zheng R, Cai Y, Liao M, Yuan W, Liu Z. Controlled-release levodopa methyl ester/benserazide-loaded nanoparticles ameliorate levodopa-induced dyskinesia in rats. Int J Nanomedicine 2012; 7:2077-86. [PMID: 22619544 PMCID: PMC3356186 DOI: 10.2147/ijn.s30463] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background Levodopa remains the most effective drug in the treatment of Parkinson’s disease. However, long-term administration of levodopa induces motor complications, such as levodopa-induced dyskinesia. The mechanisms underlying levodopa-induced dyskinesia are not fully understood. Methods In this study, we prepared levodopa methyl ester (LDME)/benserazide-loaded nanoparticles, which can release LDME and benserazide in a sustained manner. Dyskinesia was induced in rats by repeated administration of levodopa then treated with LDME plus benserazide or the same dose of LDME/benserazide-loaded nanoparticles. Apomorphine- induced rotations and abnormal involuntary movements (AIMs) were measured on treatment days 1, 5, 10, 15, and 20. In addition, the levels of phosphorylated dopamine- and cyclic adenosine monophosphate- regulated phosphoprotein of 32 kDa, extracellular signal-regulated kinases 1/2, and ΔfosB were determined by Western blot. Tau levels were determined by Western blot and immunohistochemistry. Dynorphin levels in the striatum and cortex of rats were measured using enzyme-linked immunosorbent assay. Results Over the course of levodopa treatment, the rats developed abnormal AIMs, classified as locomotive, axial, orolingual, and forelimb dyskinesia. The degree of reduction of apomorphine-induced rotations was comparable in dyskinetic rats treated with LDME plus benserazide or LDME/benserazide-loaded nanoparticles. The axial, limb, and orolingual (ALO) AIMs of dyskinetic rats treated with LDME/benserazide-loaded nanoparticles were 14 ± 2.5, 9 ± 2.0, and 10 ± 2.1 on treatment days 10, 15, and 20, respectively, which were significantly reduced compared with dyskinetic rats treated with LDME plus benserazide (25 ± 3.7, 27 ± 3.8, and 25 ± 3.5, respectively). The locomotive AIMs of dyskinetic rats treated with LDME/benserazide-loaded nanoparticles were 2.3 ± 0.42, 1.7 ± 0.35, and 1.6 ± 0.37 on treatment days 10, 15, and 20, respectively, which were also reduced compared with dyskinetic rats treated with LDME plus benserazide (4.4 ± 0.85, 4.7 ± 0.95 and 4.8 ± 0.37, respectively). Western blot showed that the levels of phosphorylated dopamine- and cyclic adenosine monophosphate-regulated phosphoprotein of 32 kDa, extracellular signal-regulated kinases 1/2, tau, and ΔfosB in dyskinetic rats treated with LDME/benserazide-loaded nanoparticles were 134.6 ± 14.1, 174.9 ± 15.1, 134.2 ± 19.3, and 320.5 ± 32.8, respectively, which were significantly reduced compared with those of dyskinetic rats treated with LDME plus benserazide (210.3 ± 19.7, 320.8 ± 21.9, 340.4 ± 27.1, and 620.7 ± 48.3, respectively). Immunohistochemistry indicated that the level of phosphorylated tau was (7.2 ± 1.1) × 104 in dyskinetic rats treated with LDME/benserazide-loaded nanoparticles. However, the tau level was only (14.6 ± 2.3) × 104 in LDME plus benserazide-treated dyskinetic rats. There was a significant difference between the two groups. Enzyme-linked immunosorbent assay showed that dynorphin levels in the striatum and cortex of dyskinetic rats treated with LDME/benserazide-loaded nanoparticles were 5.7 ± 1.2 and 4.8 ± 0.87, respectively, which were significantly reduced compared with LDME plus benserazide-treated dyskinetic rats (13.3 ± 2.1 and 8.1 ± 1.1 for the striatum and cortex, respectively). Conclusion Results suggest that LDME/benserazide-loaded nanoparticles can be used to reduce the expression of dyskinesia in dyskinetic rats.
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Affiliation(s)
- Xinxin Yang
- Department of Neurology, Xinhua Hospital (affiliated to Shanghai Jiaotong University School of Medicine), Shanghai, People's Republic of China
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Bennouar KE, Uberti MA, Melon C, Bacolod MD, Jimenez HN, Cajina M, Kerkerian-Le Goff L, Doller D, Gubellini P. Synergy between L-DOPA and a novel positive allosteric modulator of metabotropic glutamate receptor 4: implications for Parkinson's disease treatment and dyskinesia. Neuropharmacology 2012; 66:158-69. [PMID: 22491024 DOI: 10.1016/j.neuropharm.2012.03.022] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/27/2012] [Accepted: 03/24/2012] [Indexed: 11/29/2022]
Abstract
Group III metabotropic glutamate (mGlu) receptors are localized in presynaptic terminals within basal ganglia (BG) circuitry that become hyperactive due to dopamine depletion in Parkinson's disease (PD). For this reason, group III mGlu receptors, in particular mGlu4, have been considered as key strategic targets for non-dopaminergic pharmacological treatments aimed at modulating these synapses, without producing the well known side-effects of l-DOPA, in particular the highly disabling l-DOPA-induced dyskinesia (LID). Herein we add physiological and functional support to this hypothesis using Lu AF21934, a novel selective and brain-penetrant mGlu4 receptor positive allosteric modulator (PAM) tool compound. By in vitro electrophysiological recordings we demonstrate that Lu AF21934 inhibits corticostriatal synaptic transmission and enhances the effect of the orthosteric mGlu4 receptor-preferred agonist LSP1-2111. In naïve rats, Lu AF21934 dose-dependently (10 and 30 mg/kg) alleviated haloperidol-induced catalepsy. In hemiparkinsonian rats (unilateral 6-hydroxydopamine lesion of the substantia nigra pars compacta), Lu AF21934 alone did not affect akinesia at the doses tested (10 and 30 mg/kg). However, when Lu AF21934 was combined with sub-threshold doses of l-DOPA (1 and 5 mg/kg), it acted synergistically in alleviating akinesia in a dose-dependent manner and, notably, also reduced the incidence of LID but not its severity. Interestingly, these effects occurred at Lu AF21934 brain free concentrations that showed functional activity in in vitro screens (calcium flux and electrophysiology assays). These results support the potential for antiparkinsonian clinical use of a combined treatment consisting in l-DOPA and a mGlu4 receptor PAM to reduce efficacious l-DOPA doses (generally known as l-DOPA sparing), while maintaining the same benefit on PD motor troubles, and at the same time minimizing the development of LID. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Affiliation(s)
- Khaled-Ezaheir Bennouar
- Aix-Marseille Univ, Institut de Biologie du Développement de Marseille-Luminy (IBDML), UMR 7288, 13009 Marseille, France
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Negga R, Stuart JA, Machen ML, Salva J, Lizek AJ, Richardson SJ, Osborne AS, Mirallas O, McVey KA, Fitsanakis VA. Exposure to glyphosate- and/or Mn/Zn-ethylene-bis-dithiocarbamate-containing pesticides leads to degeneration of γ-aminobutyric acid and dopamine neurons in Caenorhabditis elegans. Neurotox Res 2012; 21:281-90. [PMID: 21922334 PMCID: PMC3288661 DOI: 10.1007/s12640-011-9274-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 08/18/2011] [Accepted: 08/31/2011] [Indexed: 12/14/2022]
Abstract
Previous studies demonstrate a positive correlation between pesticide usage and Parkinson's disease (PD), which preferentially targets dopaminergic (DAergic) neurons. In order to examine the potential relationship between two common pesticides and specific neurodegeneration, we chronically (24 h) or acutely (30 min) exposed two Caenorhabditis elegans (C. elegans) strains to varying concentrations (LC(25), LC(50) or LC(75)) of TouchDown(®) (TD) as percent active ingredient (glyphosate), or Mancozeb(®) (MZ) as percent active ingredient (manganese/zinc ethylene-bis-dithiocarbamate). Furthermore, to more precisely model environmental exposure, worms were also exposed to TD for 30 min, followed by 30-min incubation with varying MZ concentrations. Previous data from out lab suggested general neuronal degeneration using the worm strain NW1229 (pan-neuronal//green fluorescent protein (GFP) construct). To determine whether distinct neuronal groups were preferentially affected, we specifically used EG1285 (GABAergic neurons//GFP construct) and BZ555 (DAergic neurons//GFP construct) worms to verify GABAergic and DAergic neurodegeneration, respectively. Results indicated a statistically significant decrease, when compared to controls (CN), in number of green pixels associated with GABAergic neurons in both chronic (*P < 0.05) and acute (*P < 0.05) treatment paradigms. Analysis of the BZ555 worms indicated a statistically significant decrease (*P < 0.05) in number of green pixels associated with DAergic neurons in both treatment paradigms (chronic and acute) when compared to CN. Taken together, our data suggest that exposure to TD and/or MZ promotes neurodegeneration in both GABAergic and DAergic neurons in the model organism C. elegans.
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Affiliation(s)
- Rekek Negga
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - J Andrew Stuart
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Morgan L Machen
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Joel Salva
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Amanda J Lizek
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - S Jayne Richardson
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Amanda S Osborne
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Oriol Mirallas
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Kenneth A McVey
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
| | - Vanessa A Fitsanakis
- King College, Department of Biology, 1350 King College Road, Bristol, TN 37620 USA
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Blandini F, Armentero MT. New pharmacological avenues for the treatment of L-DOPA-induced dyskinesias in Parkinson's disease: targeting glutamate and adenosine receptors. Expert Opin Investig Drugs 2012; 21:153-68. [PMID: 22233485 DOI: 10.1517/13543784.2012.651457] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Parkinson's disease (PD) therapy is still centered on the use of L-3,4-dihydroxyphenylalanine (L-DOPA), which is hampered by numerous side effects, including abnormal involuntary movements known as L-DOPA-induced dyskinesias (LIDs). LIDs are the result of pre- and postsynaptic changes at the corticostriatal level, induced by chronic and pulsatile stimulation of striatal dopaminergic receptors. These changes impact on synaptic plasticity and involve also selected, nondopaminergic receptors expressed by striatal projection neurons. AREAS COVERED Among nondopaminergic receptors, glutamate receptors - NMDA and mGluR5 subtypes in particular - and adenosine A(2A) receptors are those most likely involved in LIDs. The aim of the present review is to summarize results of studies undertaken with specific antagonists of these receptors, first conducted in animal models of LIDs, which in selected cases have been translated into clinical trials. EXPERT OPINION Selected antagonists of glutamate and adenosine receptors have been proposed as anti-dyskinetic agents. Promising results have been obtained in preclinical investigations and in initial clinical trials, but long-term safety, tolerability and efficacy studies in patients are still required. The current development of novel antagonists, including tools able to act on receptor mosaics, may provide innovative tools for LIDs management in the next future.
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Affiliation(s)
- Fabio Blandini
- IRCCS National Neurological Institute C. Mondino, Interdepartmental Research Center for Parkinson's Disease, Via Mondino 2, 27100 Pavia, Italy.
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Marin C, Bonastre M, Aguilar E, Jiménez A. The metabotropic glutamate receptor antagonist 2-methyl-6-(phenylethynyl) pyridine decreases striatal VGlut2 expression in association with an attenuation of L-DOPA-induced dyskinesias. Synapse 2011; 65:1080-6. [PMID: 21484883 DOI: 10.1002/syn.20941] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 04/03/2011] [Indexed: 11/06/2022]
Abstract
The striatal glutamatergic hyperactivity is considered critical in the development of levodopa-induced dyskinesias (LID) in Parkinson's disease (PD). Pharmacological antagonism of the metabotropic glutamate receptors (mGluRs), in particular, the subtype mGluR5, can inhibit the expression of dyskinesia in both rodent and nonhuman primate models of PD. However, the exact mechanisms underlying the mGluR5 antagonism effects are not completely known. The vesicular glutamate transporters (VGluts) are localized in the synaptic vesicles of the striatal glutamatergic axonal terminals. The effects of mGluR5 antagonism modulating VGlut1 and VGlut2, as selective markers for the corticostriatal and thalamostriatal pathways, respectively, are still unknown. We investigated the effects of the mGluR5 antagonist, 2-methyl-6-(phenylethynyl) pyridine (MPEP) on the striatal expression of VGlut1 and VGlut2 in levodopa-treated hemiparkinsonian rats. Male Sprague-Dawley rats received a unilateral 6-hydroxydopamine (6-OHDA) administration in the nigrostriatal pathway. Rats were treated with: (a) levodopa (12 mg/kg/day with benserazide 15 mg/kg, ip) + vehicle; (b) MPEP (1.5 mg/kg/day, ip) + vehicle; (c) levodopa + MPEP, or (d) saline for 10 days. Levodopa treatment induced dyskinesias and did not modify the striatal expression of either VGlut1 or VGlut2. The administration of MPEP significantly attenuated LID and decreased the levels of VGlut2, but not the VGlut1, in the striatum ipsilateral to the lesion (P < 0.05). Our results suggest that the effects of MPEP on LID might be mediated by a modulating effect on VGlut 2 expression.
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Affiliation(s)
- C Marin
- Laboratori de Neurologia Experimental, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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Abstract
IMPORTANCE OF THE FIELD Parkinson's disease (PD) is characterized by a slowly ongoing neuronal death, which affects neurotransmitter metabolism and causes a wide variety of motor and non-motor features. Until now, therapy approaches have predominantly focused on motor behavior associated with dopamine substitution. AREAS COVERED IN THIS REVIEW This review aims to discuss putative reasons for recent failures of investigated treatment approaches, and to introduce currently tested and future compounds. WHAT THE READER WILL GAIN We will describe how development programs of novel molecules now additionally consider non-motor features of PD as promising targets in order to obtain regulatory approval. Regulatory authorities increasingly exert influence on trial designs, demanding therapeutic effects that are not always clinically feasible given the variety of manifestations of the disease entity known as PD. TAKE HOME MESSAGE In the past, research pitfalls have resulted in the failure of promising new compounds. Among the many reasons for this are massive placebo responses; the participation of too many investigators, with consequent wide variations of efficacy assessments; and a misconception of preclinical drug development, with models of PD that do not mimic its clinical nature. A few compounds are now being tested that have modes of action indirectly modulating the dopamine system; however, critical analysis of the preclinical and clinical research concept and drug approval is warranted to prevent further frustration in this field.
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Affiliation(s)
- Thomas Müller
- St. Joseph Hospital Berlin-Weissensee, Department of Neurology, Gartenstrasse 1, 13088 Berlin, Germany.
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Duty S. Therapeutic potential of targeting group III metabotropic glutamate receptors in the treatment of Parkinson's disease. Br J Pharmacol 2011; 161:271-87. [PMID: 20735415 PMCID: PMC2989582 DOI: 10.1111/j.1476-5381.2010.00882.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Current drugs used in the treatment of Parkinson's disease (PD), for example, L-DOPA and dopamine agonists, are very effective at reversing the motor symptoms of the disease. However, they do little to combat the underlying degeneration of dopaminergic neurones in the substantia nigra pars compacta (SNc) and their long-term use is associated with the appearance of adverse effects such as L-DOPA-induced dyskinesia. Much emphasis has therefore been placed on finding alternative non-dopaminergic drugs that may circumvent some or all of these problems. Group III metabotropic glutamate (mGlu) receptors were first identified in the basal ganglia a decade ago. One or more of these receptors (mGlu4, mGlu7 or mGlu8) is found on pre-synaptic terminals of basal ganglia pathways whose overactivity is implicated not only in the generation of motor symptoms in PD, but also in driving the progressive SNc degeneration. The finding that drugs which activate group III mGlu receptors can inhibit transmission across these overactive synapses has lead to the proposal that group III mGlu receptors are promising targets for drug discovery in PD. This paper provides a comprehensive review of the role and target potential of group III mGlu receptors in the basal ganglia. Overwhelming evidence obtained from in vitro studies and animal models of PD supports group III mGlu receptors as potentially important drug targets for providing both symptom relief and neuroprotection in PD.
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Affiliation(s)
- Susan Duty
- King's College London, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, UK.
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Pharmacological characterization of MRZ-8676, a novel negative allosteric modulator of subtype 5 metabotropic glutamate receptors (mGluR5): focus on l-DOPA-induced dyskinesia. J Neural Transm (Vienna) 2010; 118:1703-16. [DOI: 10.1007/s00702-010-0526-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 11/02/2010] [Indexed: 11/26/2022]
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Abstract
This paper is the 32nd consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2009 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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30
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Nicoletti F, Bockaert J, Collingridge GL, Conn PJ, Ferraguti F, Schoepp DD, Wroblewski JT, Pin JP. Metabotropic glutamate receptors: from the workbench to the bedside. Neuropharmacology 2010; 60:1017-41. [PMID: 21036182 DOI: 10.1016/j.neuropharm.2010.10.022] [Citation(s) in RCA: 476] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 10/15/2010] [Accepted: 10/21/2010] [Indexed: 12/24/2022]
Abstract
Metabotropic glutamate (mGlu) receptors were discovered in the mid 1980s and originally described as glutamate receptors coupled to polyphosphoinositide hydrolysis. Almost 6500 articles have been published since then, and subtype-selective mGlu receptor ligands are now under clinical development for the treatment of a variety of disorders such as Fragile-X syndrome, schizophrenia, Parkinson's disease and L-DOPA-induced dyskinesias, generalized anxiety disorder, chronic pain, and gastroesophageal reflux disorder. Prof. Erminio Costa was linked to the early times of the mGlu receptor history, when a few research groups challenged the general belief that glutamate could only activate ionotropic receptors and all metabolic responses to glutamate were secondary to calcium entry. This review moves from those nostalgic times to the most recent advances in the physiology and pharmacology of mGlu receptors, and highlights the role of individual mGlu receptor subtypes in the pathophysiology of human disorders. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.
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Affiliation(s)
- F Nicoletti
- Department of Physiology and Pharmacology, University of Rome, Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
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31
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Buck K, Ferger B. l-DOPA-induced dyskinesia in Parkinson's disease: a drug discovery perspective. Drug Discov Today 2010; 15:867-75. [DOI: 10.1016/j.drudis.2010.08.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 07/28/2010] [Accepted: 08/20/2010] [Indexed: 12/26/2022]
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32
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Calabresi P, Di Filippo M, Ghiglieri V, Tambasco N, Picconi B. Levodopa-induced dyskinesias in patients with Parkinson's disease: filling the bench-to-bedside gap. Lancet Neurol 2010; 9:1106-17. [PMID: 20880751 DOI: 10.1016/s1474-4422(10)70218-0] [Citation(s) in RCA: 278] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Levodopa is the most effective drug for the treatment of Parkinson's disease. However, the long-term use of this dopamine precursor is complicated by highly disabling fluctuations and dyskinesias. Although preclinical and clinical findings suggest pulsatile stimulation of striatal postsynaptic receptors as a key mechanism underlying levodopa-induced dyskinesias, their pathogenesis is still unclear. In recent years, evidence from animal models of Parkinson's disease has provided important information to understand the effect of specific receptor and post-receptor molecular mechanisms underlying the development of dyskinetic movements. Recent preclinical and clinical data from promising lines of research focus on the differential role of presynaptic versus postsynaptic mechanisms, dopamine receptor subtypes, ionotropic and metabotropic glutamate receptors, and non-dopaminergic neurotransmitter systems in the pathophysiology of levodopa-induced dyskinesias.
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Affiliation(s)
- Paolo Calabresi
- Clinica Neurologica, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, Perugia, Italy.
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Rylander D, Iderberg H, Li Q, Dekundy A, Zhang J, Li H, Baishen R, Danysz W, Bezard E, Cenci MA. A mGluR5 antagonist under clinical development improves L-DOPA-induced dyskinesia in parkinsonian rats and monkeys. Neurobiol Dis 2010; 39:352-61. [DOI: 10.1016/j.nbd.2010.05.001] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/28/2010] [Accepted: 05/01/2010] [Indexed: 10/19/2022] Open
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Morin N, Grégoire L, Gomez-Mancilla B, Gasparini F, Di Paolo T. Effect of the metabotropic glutamate receptor type 5 antagonists MPEP and MTEP in parkinsonian monkeys. Neuropharmacology 2010; 58:981-6. [PMID: 20074579 DOI: 10.1016/j.neuropharm.2009.12.024] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 12/22/2009] [Accepted: 12/25/2009] [Indexed: 11/27/2022]
Abstract
Brain glutamate overactivity is well documented in Parkinson's disease (PD) and antiglutamatergic drugs have been proposed to relieve PD symptoms and decrease dyskinesias. Metabotropic glutamate receptors are topics of recent interest in PD. This study investigated the effects of the metabotropic glutamate receptors type 5 (mGluR5) antagonists MPEP and MTEP on motor behavior in monkeys with a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) lesion to model PD and treated with L-Dopa the gold standard therapy. Six Macaca fascicularis MPTP monkeys were initially treated repeatedly with L-Dopa; this treatment increased their locomotion and reduced their parkinsonian scores but also induced dyskinesias. Then, a dose-response of MPEP and MTEP (1.5-30 mg/kg) administered 15 and 30 min respectively prior to L-Dopa, showed that the antiparkinsonian activity of L-Dopa was generally maintained as measured with locomotion and antiparkinsonian scores as well as the onset and duration of the L-Dopa response. Interestingly the mean dyskinesia score during all the duration of the L-Dopa motor effect, the 1 h peak period dyskinesias scores as well as the maximal dyskinesias scores were dose-dependently reduced with both drugs reaching statistical significance at 10 and 30 mg/kg. Our results showed a beneficial antidyskinetic effect of blocking mGluR5 in L-Dopa-treated MPTP monkeys. This supports the therapeutic use of an mGluR5 antagonist to restore normal brain glutamate neurotransmission in PD and decrease dyskinesias.
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Affiliation(s)
- Nicolas Morin
- Molecular Endocrinology and Genomic Research Center, Laval University Medical Center (CHUL), 2705 Laurier Blvd, Quebec (QC), Canada
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