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Dopamine receptor heteromeric complexes and their emerging functions. PROGRESS IN BRAIN RESEARCH 2014; 211:183-200. [DOI: 10.1016/b978-0-444-63425-2.00008-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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102
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Jaeger WC, Armstrong SP, Hill SJ, Pfleger KDG. Biophysical Detection of Diversity and Bias in GPCR Function. Front Endocrinol (Lausanne) 2014; 5:26. [PMID: 24634666 PMCID: PMC3943086 DOI: 10.3389/fendo.2014.00026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 02/19/2014] [Indexed: 12/27/2022] Open
Abstract
Guanine nucleotide binding protein (G protein)-coupled receptors (GPCRs) function in complexes with a range of molecules and proteins including ligands, G proteins, arrestins, ubiquitin, and other receptors. Elements of these complexes may interact constitutively or dynamically, dependent upon factors such as ligand binding, phosphorylation, and dephosphorylation. They may also be allosterically modulated by other proteins in a manner that changes temporally and spatially within the cell. Elucidating how these complexes function has been greatly enhanced by biophysical technologies that are able to monitor proximity and/or binding, often in real time and in live cells. These include resonance energy transfer approaches such as bioluminescence resonance energy transfer (BRET) and fluorescence resonance energy transfer (FRET). Furthermore, the use of fluorescent ligands has enabled novel insights into allosteric interactions between GPCRs. Consequently, biophysical approaches are helping to unlock the amazing diversity and bias in G protein-coupled receptor signaling.
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Affiliation(s)
- Werner C. Jaeger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Stephen P. Armstrong
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Stephen J. Hill
- Cell Signalling Research Group, School of Life Sciences, Queen’s Medical Centre, University of Nottingham Medical School, Nottingham, UK
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
- Dimerix Bioscience Pty Ltd, Perth, WA, Australia
- *Correspondence: Kevin D. G. Pfleger, Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, QQ Block, 6 Verdun Street, Nedlands, Perth, WA 6009, Australia e-mail:
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103
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Kern A, Grande C, Smith RG. Apo-Ghrelin Receptor (apo-GHSR1a) Regulates Dopamine Signaling in the Brain. Front Endocrinol (Lausanne) 2014; 5:129. [PMID: 25183960 PMCID: PMC4135303 DOI: 10.3389/fendo.2014.00129] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/18/2014] [Indexed: 12/29/2022] Open
Abstract
The orexigenic peptide hormone ghrelin is synthesized in the stomach and its receptor growth hormone secretagogue receptor (GHSR1a) is expressed mainly in the central nervous system (CNS). In this review, we confine our discussion to the physiological role of GHSR1a in the brain. Paradoxically, despite broad expression of GHSR1a in the CNS, other than trace amounts in the hypothalamus, ghrelin is undetectable in the brain. In our efforts to elucidate the function of the ligand-free ghrelin receptor (apo-GHSR1a), we identified subsets of neurons that co-express GHSR1a and dopamine receptors. In this review, we focus on interactions between apo-GHSR1a and dopamine-2 receptor (DRD2) and formation of GHSR1a:DRD2 heteromers in hypothalamic neurons that regulate appetite, and discuss implications for the treatment of Prader-Willi syndrome (PWS). GHSR1a antagonists of distinct chemical structures, a quinazolinone and a triazole, respectively, enhance and inhibit dopamine signaling through GHSR1a:DRD2 heteromers by an allosteric mechanism. This finding illustrates a potential strategy for designing the next generation of drugs for treating eating disorders as well as psychiatric disorders caused by abnormal dopamine signaling. Treatment with a GHSR1a antagonist that enhances dopamine/DRD2 activity in GHSR1a:DRD2 expressing hypothalamic neurons has the potential to inhibit the uncontrollable hyperphagia associated with PWS. DRD2 antagonists are prescribed for treating schizophrenia, but these block dopamine signaling in all DRD2 expressing neurons and are associated with adverse side effects, including enhanced appetite and excessive weight gain. A GHSR1a antagonist of structural class that allosterically blocks dopamine/DRD2 action in GHSR1a:DRD2 expressing neurons would have no effect on neurons expressing DRD2 alone; therefore, the side effects of DRD2 antagonists would potentially be reduced thereby enhancing patient compliance.
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Affiliation(s)
- Andras Kern
- Department of Metabolism and Aging, Scripps Research Institute Florida, Jupiter, FL, USA
| | - Cristina Grande
- Department of Metabolism and Aging, Scripps Research Institute Florida, Jupiter, FL, USA
| | - Roy G. Smith
- Department of Metabolism and Aging, Scripps Research Institute Florida, Jupiter, FL, USA
- *Correspondence: Roy G. Smith, Department of Metabolism and Aging, Scripps Research Institute Florida, 130 Scripps Way #3B3, Jupiter, FL 33458, USA e-mail:
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104
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Ojeda DA, Niño CL, López-León S, Camargo A, Adan A, Forero DA. A functional polymorphism in the promoter region of MAOA gene is associated with daytime sleepiness in healthy subjects. J Neurol Sci 2013; 337:176-9. [PMID: 24360188 DOI: 10.1016/j.jns.2013.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/26/2013] [Accepted: 12/03/2013] [Indexed: 12/14/2022]
Abstract
Excessive daytime sleepiness (EDS) is one of the main causes of car and industrial accidents and it is associated with increased morbidity and alterations in quality of life. Prevalence of EDS in the general population around the world ranges from 6.2 to 32.4%, with a heritability of 38-40%. However, few studies have explored the role of candidate genes in EDS. Monoamine oxidase A (MAOA) gene has an important role in the regulation of neurotransmitter levels and a large number of human behaviors. We hypothesized that a functional VNTR in the promoter region of the MAOA gene might be associated with daytime sleepiness in healthy individuals. The Epworth sleepiness scale (ESS) was applied to 210 Colombian healthy subjects (university students), which were genotyped for MAOA-uVNTR. MAOA-uVNTR showed a significant association with ESS scores (p = 0.01): 3/3 genotype carriers had the lowest scores. These results were supported by differences in MAOA-uVNTR frequencies between diurnal somnolence categories (p = 0.03). Our finding provides evidence for the first time that MAOA-uVNTR has a significant association with EDS in healthy subjects. Finally, these data suggest that functional variations in MAOA gene could have a role in other phenotypes of neuropsychiatric relevance.
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Affiliation(s)
- Diego A Ojeda
- Laboratory of Neuropsychiatric Genetics, Biomedical Sciences Research Group, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia
| | - Carmen L Niño
- School of Nursing, Universidad de Ciencias Aplicadas y Ambientales UDCA, Bogotá, Colombia
| | | | - Andrés Camargo
- School of Nursing, Universidad de Ciencias Aplicadas y Ambientales UDCA, Bogotá, Colombia
| | - Ana Adan
- Department of Psychiatry and Clinical Psychobiology, School of Psychology, University of Barcelona, Barcelona, Spain
| | - Diego A Forero
- Laboratory of Neuropsychiatric Genetics, Biomedical Sciences Research Group, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia.
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105
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Gomes I, Fujita W, Chandrakala MV, Devi LA. Disease-specific heteromerization of G-protein-coupled receptors that target drugs of abuse. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 117:207-65. [PMID: 23663971 DOI: 10.1016/b978-0-12-386931-9.00009-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Drugs of abuse such as morphine or marijuana exert their effects through the activation of G-protein-coupled receptors (GPCRs), the opioid and cannabinoid receptors, respectively. Moreover, interactions between either of these receptors have been shown to be involved in the rewarding effects of drugs of abuse. Recent advances in the field, using a variety of approaches, have demonstrated that many GPCRs, including opioid, cannabinoid, and dopamine receptors, can form associations between different receptor subtypes or with other GPCRs to form heteromeric complexes. The formation of these complexes, in turn, leads to the modulation of the properties of individual protomers. The development of tools that can selectively disrupt GPCR heteromers as well as monoclonal antibodies that can selectively block signaling by specific heteromer pairs has indicated that heteromers involving opioid, cannabinoid, or dopamine receptors may play a role in various disease states. In this review, we describe evidence for opioid, cannabinoid, and dopamine receptor heteromerization and the potential role of GPCR heteromers in pathophysiological conditions.
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Affiliation(s)
- Ivone Gomes
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, USA
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106
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L-DOPA-treatment in primates disrupts the expression of A(2A) adenosine-CB(1) cannabinoid-D(2) dopamine receptor heteromers in the caudate nucleus. Neuropharmacology 2013; 79:90-100. [PMID: 24230991 DOI: 10.1016/j.neuropharm.2013.10.036] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 11/21/2022]
Abstract
The molecular basis of priming for L-DOPA-induced dyskinesias in Parkinson's disease (PD), which depends on the indirect pathway of motor control, is not known. In rodents, the indirect pathway contains striatopallidal GABAergic neurons that express heterotrimers composed of A(2A) adenosine, CB(1) cannabinoid and D(2) dopamine receptors that regulate dopaminergic neurotransmission. The present study was designed to investigate the expression of these heteromers in the striatum of a primate model of Parkinson's disease and to determine whether their expression and pharmacological properties are altered upon L-DOPA treatment. By using the recently developed in situ proximity ligation assay and by identification of a biochemical fingerprint, we discovered a regional distribution of A(2A)/CB(1) /D(2) receptor heteromers that predicts differential D(2)-mediated neurotransmission in the caudate-putamen of Macaca fascicularis. Whereas heteromers were abundant in the caudate nucleus of both naïve and MPTP-treated monkeys, L-DOPA treatment blunted the biochemical fingerprint and led to weak heteromer expression. These findings constitute the first evidence of altered receptor heteromer expression in pathological conditions and suggest that drugs targeting A(2A)-CB(1) -D(2) receptor heteromers may be successful to either normalize basal ganglia output or prevent L-DOPA-induced side effects.
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107
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Mitrano DA, Pare JF, Smith Y, Weinshenker D. D1-dopamine and α1-adrenergic receptors co-localize in dendrites of the rat prefrontal cortex. Neuroscience 2013; 258:90-100. [PMID: 24231738 DOI: 10.1016/j.neuroscience.2013.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 10/30/2013] [Accepted: 11/01/2013] [Indexed: 01/30/2023]
Abstract
Functional interactions between dopaminergic and noradrenergic systems occur in many brain areas, including the prefrontal cortex (PFC). Biochemical, electrophysiological and behavioral data indicate crosstalk between D1 dopamine receptor (D1R) and α1-adrenergic receptor (α1AR) signaling in the PFC. However, it is unknown whether these interactions occur within the same neurons, or between neurons expressing either receptor. In this study, we used electron microscopy immunocytochemistry to demonstrate that D1Rs and α1ARs co-localize in rat PFC neuronal elements, most prominently in dendrites (60-70%), but also significantly in axon terminals, unmyelinated axons and spines (∼20-30%). Our data also showed that the ratio of plasma membrane-bound to intracellular α1ARs is significantly reduced in D1R-expressing dendrites. Similar results were obtained using either a pan-α1AR or a selective α1bAR antibody to label noradrenergic receptors. Thus, these results demonstrate that D1Rs and α1ARs co-localize in PFC dendrites, thereby suggesting that the catecholaminergic effects on PFC function may be driven, at least in part, by cell-autonomous D1R-α1AR interactions.
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Affiliation(s)
- D A Mitrano
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - J-F Pare
- Department of Neurology and Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Y Smith
- Department of Neurology and Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - D Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, United States.
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108
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Baba K, Benleulmi-Chaachoua A, Journé AS, Kamal M, Guillaume JL, Dussaud S, Gbahou F, Yettou K, Liu C, Contreras-Alcantara S, Jockers R, Tosini G. Heteromeric MT1/MT2 melatonin receptors modulate photoreceptor function. Sci Signal 2013; 6:ra89. [PMID: 24106342 DOI: 10.1126/scisignal.2004302] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The formation of G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor (GPCR) heteromers enables signaling diversification and holds great promise for improved drug selectivity. Most studies of these oligomerization events have been conducted in heterologous expression systems, and in vivo validation is lacking in most cases, thus questioning the physiological significance of GPCR heteromerization. The melatonin receptors MT1 and MT2 exist as homomers and heteromers when expressed in cultured cells. We showed that melatonin MT1/MT2 heteromers mediated the effect of melatonin on the light sensitivity of rod photoreceptors in mice. This effect of melatonin involved activation of the heteromer-specific phospholipase C and protein kinase C (PLC/PKC) pathway and was abolished in MT1(-/-) or MT2(-/-) mice, as well as in mice overexpressing a nonfunctional MT2 mutant that interfered with the formation of functional MT1/MT2 heteromers in photoreceptor cells. Not only does this study establish an essential role of melatonin receptor heteromers in retinal function, it also provides in vivo support for the physiological importance of GPCR heteromerization. Thus, the MT1/MT2 heteromer complex may provide a specific pharmacological target to improve photoreceptor function.
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Affiliation(s)
- Kenkichi Baba
- 1Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA 30310, USA
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109
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Furth KE, Mastwal S, Wang KH, Buonanno A, Vullhorst D. Dopamine, cognitive function, and gamma oscillations: role of D4 receptors. Front Cell Neurosci 2013; 7:102. [PMID: 23847468 PMCID: PMC3698457 DOI: 10.3389/fncel.2013.00102] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 06/11/2013] [Indexed: 12/29/2022] Open
Abstract
Cognitive deficits in individuals with schizophrenia (SCZ) are considered core symptoms of this disorder, and can manifest at the prodromal stage. Antipsychotics ameliorate positive symptoms but only modestly improve cognitive symptoms. The lack of treatments that improve cognitive abilities currently represents a major obstacle in developing more effective therapeutic strategies for this debilitating disorder. While D4 receptor (D4R)-specific antagonists are ineffective in the treatment of positive symptoms, animal studies suggest that D4R drugs can improve cognitive deficits. Moreover, recent work from our group suggests that D4Rs synergize with the neuregulin/ErbB4 signaling pathway, genetically identified as risk factors for SCZ, in parvalbumin (PV)-expressing interneurons to modulate gamma oscillations. These high-frequency network oscillations correlate with attention and increase during cognitive tasks in healthy subjects, and this correlation is attenuated in affected individuals. This finding, along with other observations indicating impaired GABAergic function, has led to the idea that abnormal neural activity in the prefrontal cortex (PFC) in individuals with SCZ reflects a perturbation in the balance of excitation and inhibition. Here we review the current state of knowledge of D4R functions in the PFC and hippocampus, two major brain areas implicated in SCZ. Special emphasis is given to studies focusing on the potential role of D4Rs in modulating GABAergic transmission and to an emerging concept of a close synergistic relationship between dopamine/D4R and neuregulin/ErbB4 signaling pathways that tunes the activity of PV interneurons to regulate gamma frequency network oscillations and potentially cognitive processes.
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Affiliation(s)
- Katrina E Furth
- Section on Molecular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA ; Graduate Program for Neuroscience, Boston University Boston, MA, USA
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110
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De Berardis D, Marini S, Fornaro M, Srinivasan V, Iasevoli F, Tomasetti C, Valchera A, Perna G, Quera-Salva MA, Martinotti G, di Giannantonio M. The melatonergic system in mood and anxiety disorders and the role of agomelatine: implications for clinical practice. Int J Mol Sci 2013; 14:12458-83. [PMID: 23765220 PMCID: PMC3709794 DOI: 10.3390/ijms140612458] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 05/22/2013] [Accepted: 05/22/2013] [Indexed: 02/07/2023] Open
Abstract
Melatonin exerts its actions through membrane MT1/MT2 melatonin receptors, which belong to the super family of G-protein-coupled receptors consisting of the typical seven transmembrane domains. MT1 and MT2 receptors are expressed in various tissues of the body either as single ones or together. A growing literature suggests that the melatonergic system may be involved in the pathophysiology of mood and anxiety disorders. In fact, some core symptoms of depression show disturbance of the circadian rhythm in their clinical expression, such as diurnal mood and other symptomatic variation, or are closely linked to circadian system functioning, such as sleep-wake cycle alterations. In addition, alterations have been described in the circadian rhythms of several biological markers in depressed patients. Therefore, there is interest in developing antidepressants that have a chronobiotic effect (i.e., treatment of circadian rhythm disorders). As melatonin produces chronobiotic effects, efforts have been aimed at developing agomelatine, an antidepressant with melatonin agonist activity. The present paper reviews the role of the melatonergic system in the pathophysiology of mood and anxiety disorders and the clinical characteristics of agomelatine. Implications of agomelatine in "real world" clinical practice will be also discussed.
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Affiliation(s)
- Domenico De Berardis
- National Health Service, Department of Mental Health, Psychiatric Service of Diagnosis and Treatment, Hospital “G. Mazzini”, ASL 4 Teramo, Italy; E-Mail:
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +39-0861429708; Fax: +39-0861429706
| | - Stefano Marini
- National Health Service, Department of Mental Health, Psychiatric Service of Diagnosis and Treatment, Hospital “G. Mazzini”, ASL 4 Teramo, Italy; E-Mail:
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
| | - Michele Fornaro
- Department of “Scienze della Formazione”, University of Catania, Catania 95121, Italy; E-Mail:
| | - Venkataramanujam Srinivasan
- Sri Sathya Sai Medical Educational and Research Foundation, Medical Sciences Research Study Center, Prasanthi Nilayam, 40-Kovai Thirunagar Coimbatore, Tamilnadu 641014, India; E-Mail:
| | - Felice Iasevoli
- Laboratory of Molecular Psychiatry and Psychopharmacotherapeutics, Section of Psychiatry, Department of Neuroscience, University School of Medicine “Federico II”, Naples 80131, Italy; E-Mails: (F.I.); (C.T.)
| | - Carmine Tomasetti
- Laboratory of Molecular Psychiatry and Psychopharmacotherapeutics, Section of Psychiatry, Department of Neuroscience, University School of Medicine “Federico II”, Naples 80131, Italy; E-Mails: (F.I.); (C.T.)
| | - Alessandro Valchera
- Hermanas Hospitalarias, FoRiPsi, Villa S. Giuseppe Hospital, Ascoli Piceno 63100, Italy; E-Mail:
| | - Giampaolo Perna
- Hermanas Hospitalarias, FoRiPsi, Department of Clinical Neurosciences, Villa San Benedetto Menni, Albese con Cassano, Como 22032, Italy; E-Mail:
- Department of Psychiatry and Behavioral Sciences, Leonard Miller School of Medicine, University of Miami, 33124 Miami, USA
- Department of Psychiatry and Neuropsychology, University of Maastricht, 6200 MD Maastricht, The Netherlands
| | - Maria-Antonia Quera-Salva
- AP-HP Sleep Unit, Department of Physiology, Raymond Poincaré Hospital, Garches 92380, France; E-Mail:
| | - Giovanni Martinotti
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
| | - Massimo di Giannantonio
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
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111
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Chun LS, Free RB, Doyle TB, Huang XP, Rankin ML, Sibley DR. D1-D2 dopamine receptor synergy promotes calcium signaling via multiple mechanisms. Mol Pharmacol 2013; 84:190-200. [PMID: 23680635 DOI: 10.1124/mol.113.085175] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The D(1) dopamine receptor (D(1)R) has been proposed to form a hetero-oligomer with the D(2) dopamine receptor (D(2)R), which in turn results in a complex that couples to phospholipase C-mediated intracellular calcium release. We have sought to elucidate the pharmacology and mechanism of action of this putative signaling pathway. Dopamine dose-response curves assaying intracellular calcium mobilization in cells heterologously expressing the D(1) and D(2) subtypes, either alone or in combination, and using subtype selective ligands revealed that concurrent stimulation is required for coupling. Surprisingly, characterization of a putative D(1)-D(2) heteromer-selective ligand, 6-chloro-2,3,4,5-tetrahydro-3-methyl-1-(3-methylphenyl)-1H-3-benzazepine-7,8-diol (SKF83959), found no stimulation of calcium release, but it did find a broad range of cross-reactivity with other G protein-coupled receptors. In contrast, SKF83959 appeared to be an antagonist of calcium mobilization. Overexpression of G(qα) with the D(1) and D(2) dopamine receptors enhanced the dopamine-stimulated calcium response. However, this was also observed in cells expressing G(qα) with only the D1R. Inactivation of Gi or Gs with pertussis or cholera toxin, respectively, largely, but not entirely, reduced the calcium response in D(1)R and D(2)R cotransfected cells. Moreover, sequestration of G(βγ) subunits through overexpression of G protein receptor kinase 2 mutants either completely or largely eliminated dopamine-stimulated calcium mobilization. Our data suggest that the mechanism of D(1)R/D(2)R-mediated calcium signaling involves more than receptor-mediated G(q) protein activation, may largely involve downstream signaling pathways, and may not be completely heteromer-specific. In addition, SKF83959 may not exhibit selective activation of D(1)-D(2) heteromers, and its significant cross-reactivity to other receptors warrants careful interpretation of its use in vivo.
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Affiliation(s)
- Lani S Chun
- Molecular Neuropharmacology Section, National Institute of Neurologic Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-9405, USA
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112
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Navarro G, Moreno E, Bonaventura J, Brugarolas M, Farré D, Aguinaga D, Mallol J, Cortés A, Casadó V, Lluís C, Ferre S, Franco R, Canela E, McCormick PJ. Cocaine inhibits dopamine D2 receptor signaling via sigma-1-D2 receptor heteromers. PLoS One 2013; 8:e61245. [PMID: 23637801 PMCID: PMC3630156 DOI: 10.1371/journal.pone.0061245] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
Under normal conditions the brain maintains a delicate balance between inputs of reward seeking controlled by neurons containing the D1-like family of dopamine receptors and inputs of aversion coming from neurons containing the D2-like family of dopamine receptors. Cocaine is able to subvert these balanced inputs by altering the cell signaling of these two pathways such that D1 reward seeking pathway dominates. Here, we provide an explanation at the cellular and biochemical level how cocaine may achieve this. Exploring the effect of cocaine on dopamine D2 receptors function, we present evidence of σ1 receptor molecular and functional interaction with dopamine D2 receptors. Using biophysical, biochemical, and cell biology approaches, we discovered that D2 receptors (the long isoform of the D2 receptor) can complex with σ1 receptors, a result that is specific to D2 receptors, as D3 and D4 receptors did not form heteromers. We demonstrate that the σ1-D2 receptor heteromers consist of higher order oligomers, are found in mouse striatum and that cocaine, by binding to σ1 -D2 receptor heteromers, inhibits downstream signaling in both cultured cells and in mouse striatum. In contrast, in striatum from σ1 knockout animals these complexes are not found and this inhibition is not seen. Taken together, these data illuminate the mechanism by which the initial exposure to cocaine can inhibit signaling via D2 receptor containing neurons, destabilizing the delicate signaling balance influencing drug seeking that emanates from the D1 and D2 receptor containing neurons in the brain.
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Affiliation(s)
- Gemma Navarro
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Estefania Moreno
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Jordi Bonaventura
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Marc Brugarolas
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Daniel Farré
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - David Aguinaga
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Josefa Mallol
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Antoni Cortés
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Vicent Casadó
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Carmen Lluís
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Sergi Ferre
- National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland, United States of America
| | - Rafael Franco
- Centro de Investigación Médica Aplicada, Universidad de Navarra, Pamplona, Spain
| | - Enric Canela
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Peter J. McCormick
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and Institute of Biomedicine of the University of Barcelona (IBUB) and Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
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Franco R, Martínez-Pinilla E, Ricobaraza A, McCormick PJ. Challenges in the development of heteromer-GPCR-based drugs. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 117:143-62. [PMID: 23663968 DOI: 10.1016/b978-0-12-386931-9.00006-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
G-protein-coupled receptors are targets of a variety of diseases. Drug screening has been classically performed assuming the occurrence of monomeric receptors. As more and more receptor heteromers are identified, the challenge is now to develop screening assays to select heteromer-specific drugs. These drugs may, for instance, be able to interact preferentially with prerather than with postsynaptic receptors. Heteromer-based drug discovery opens new perspectives in both Academic pursuits and for the Pharmaceutical industry.
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Affiliation(s)
- Rafael Franco
- Applied Medical Research Center (CIMA), University of Navarra, Pamplona, Spain
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