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LaCrosse AL, May CE, Griffin WC, Olive MF. mGluR5 positive allosteric modulation prevents MK-801 induced increases in extracellular glutamate in the rat medial prefrontal cortex. Neuroscience 2024; 555:83-91. [PMID: 39019391 PMCID: PMC11344657 DOI: 10.1016/j.neuroscience.2024.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 07/19/2024]
Abstract
Potentiation of metabotropic glutamate receptor subtype 5 (mGluR5) function produces antipsychotic-like and pro-cognitive effects in animal models of schizophrenia and can reverse cognitive deficits induced by N-methyl-D-aspartate type glutamate receptor (NMDAR) antagonists. However, it is currently unknown if mGluR5 positive allosteric modulators (PAMs) can modulate NMDAR antagonist-induced alterations in extracellular glutamate levels in regions underlying these cognitive and behavioral effects, such as the medial prefrontal cortex (mPFC). We therefore assessed the ability of the mGluR5 PAM, 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl) benzamide (CDPPB), to reduce elevated extracellular glutamate levels induced by the NMDAR antagonist, dizocilpine (MK-801), in the mPFC. Male Sprague-Dawley rats were implanted with a guide cannula aimed at the mPFC and treated for ten consecutive days with MK-801 and CDPPB or their corresponding vehicles. CDPPB or vehicle was administered thirty minutes before MK-801 or vehicle each day. On the final day of treatment, in vivo microdialysis was performed, and samples were collected every thirty minutes to analyze extracellular glutamate levels. Compared to animals receiving only vehicle, administration of MK-801 alone significantly increased extracellular levels of glutamate in the mPFC. This effect was not observed in animals administered CDPPB before MK-801, nor in those administered CDPPB alone, indicating that CDPPB decreased extracellular glutamate release stimulated by MK-801. Results indicate that CDPPB attenuates MK-801 induced elevations in extracellular glutamate in the mPFC. This effect of CDPPB may underlie neurochemical adaptations associated with the pro-cognitive effects of mGluR5 PAMs in rodent models of schizophrenia.
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Affiliation(s)
- Amber L LaCrosse
- Department of Psychology, Arizona State University, 950 S. McAllister Ave., Tempe, AZ 85281, United States; Department of Psychological Science, Northern Michigan University, 1401 Presque Isle Ave, Marquette, MI 49855, United States.
| | - Christina E May
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, MSC 861, 67 President Street, Charleston, SC 29425, United States; Department of Neuroscience and Physiology, New York University Grossman School of Medicine, 550 First Avenue, New York, NY 10016, United States
| | - William C Griffin
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, MSC 861, 67 President Street, Charleston, SC 29425, United States
| | - M Foster Olive
- Department of Psychology, Arizona State University, 950 S. McAllister Ave., Tempe, AZ 85281, United States
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2
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Boutonnet M, Carpena C, Bouquier N, Chastagnier Y, Font-Ingles J, Moutin E, Tricoire L, Chemin J, Perroy J. Voltage tunes mGlu 5 receptor function, impacting synaptic transmission. Br J Pharmacol 2024; 181:1793-1811. [PMID: 38369690 DOI: 10.1111/bph.16317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/08/2023] [Accepted: 12/29/2023] [Indexed: 02/20/2024] Open
Abstract
BACKGROUND AND PURPOSE Voltage sensitivity is a common feature of many membrane proteins, including some G-protein coupled receptors (GPCRs). However, the functional consequences of voltage sensitivity in GPCRs are not well understood. EXPERIMENTAL APPROACH In this study, we investigated the voltage sensitivity of the post-synaptic metabotropic glutamate receptor mGlu5 and its impact on synaptic transmission. Using biosensors and electrophysiological recordings in non-excitable HEK293T cells or neurons. KEY RESULTS We found that mGlu5 receptor function is optimal at resting membrane potentials. We observed that membrane depolarization significantly reduced mGlu5 receptor activation, Gq-PLC/PKC stimulation, Ca2+ release and mGlu5 receptor-gated currents through transient receptor potential canonical, TRPC6, channels or glutamate ionotropic NMDA receptors. Notably, we report a previously unknown activity of the NMDA receptor at the resting potential of neurons, enabled by mGlu5. CONCLUSIONS AND IMPLICATIONS Our findings suggest that mGlu5 receptor activity is directly regulated by membrane voltage which may have a significant impact on synaptic processes and pathophysiological functions.
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Affiliation(s)
- Marin Boutonnet
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Camille Carpena
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | | | - Yan Chastagnier
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Joan Font-Ingles
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
- SpliceBio, Barcelona, Spain
| | - Enora Moutin
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Ludovic Tricoire
- Neuroscience Paris Seine, Institut de biologie Paris Seine, Sorbonne universite, CNRS, INSERM, Paris, France
| | - Jean Chemin
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Julie Perroy
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
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3
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Budgett RF, Bakker G, Sergeev E, Bennett KA, Bradley SJ. Targeting the Type 5 Metabotropic Glutamate Receptor: A Potential Therapeutic Strategy for Neurodegenerative Diseases? Front Pharmacol 2022; 13:893422. [PMID: 35645791 PMCID: PMC9130574 DOI: 10.3389/fphar.2022.893422] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/18/2022] [Indexed: 01/13/2023] Open
Abstract
The type 5 metabotropic glutamate receptor, mGlu5, has been proposed as a potential therapeutic target for the treatment of several neurodegenerative diseases. In preclinical neurodegenerative disease models, novel allosteric modulators have been shown to improve cognitive performance and reduce disease-related pathology. A common pathological hallmark of neurodegenerative diseases is a chronic neuroinflammatory response, involving glial cells such as astrocytes and microglia. Since mGlu5 is expressed in astrocytes, targeting this receptor could provide a potential mechanism by which neuroinflammatory processes in neurodegenerative disease may be modulated. This review will discuss current evidence that highlights the potential of mGlu5 allosteric modulators to treat neurodegenerative diseases, including Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Furthermore, this review will explore the role of mGlu5 in neuroinflammatory responses, and the potential for this G protein-coupled receptor to modulate neuroinflammation.
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Affiliation(s)
- Rebecca F Budgett
- The Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | | | | | - Sophie J Bradley
- The Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.,Sosei Heptares, Cambridge, United Kingdom
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4
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Gregory KJ, Goudet C. International Union of Basic and Clinical Pharmacology. CXI. Pharmacology, Signaling, and Physiology of Metabotropic Glutamate Receptors. Pharmacol Rev 2020; 73:521-569. [PMID: 33361406 DOI: 10.1124/pr.119.019133] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Metabotropic glutamate (mGlu) receptors respond to glutamate, the major excitatory neurotransmitter in the mammalian brain, mediating a modulatory role that is critical for higher-order brain functions such as learning and memory. Since the first mGlu receptor was cloned in 1992, eight subtypes have been identified along with many isoforms and splice variants. The mGlu receptors are transmembrane-spanning proteins belonging to the class C G protein-coupled receptor family and represent attractive targets for a multitude of central nervous system disorders. Concerted drug discovery efforts over the past three decades have yielded a wealth of pharmacological tools including subtype-selective agents that competitively block or mimic the actions of glutamate or act allosterically via distinct sites to enhance or inhibit receptor activity. Herein, we review the physiologic and pathophysiological roles for individual mGlu receptor subtypes including the pleiotropic nature of intracellular signal transduction arising from each. We provide a comprehensive analysis of the in vitro and in vivo pharmacological properties of prototypical and commercially available orthosteric agonists and antagonists as well as allosteric modulators, including ligands that have entered clinical trials. Finally, we highlight emerging areas of research that hold promise to facilitate rational design of highly selective mGlu receptor-targeting therapeutics in the future. SIGNIFICANCE STATEMENT: The metabotropic glutamate receptors are attractive therapeutic targets for a range of psychiatric and neurological disorders. Over the past three decades, intense discovery efforts have yielded diverse pharmacological tools acting either competitively or allosterically, which have enabled dissection of fundamental biological process modulated by metabotropic glutamate receptors and established proof of concept for many therapeutic indications. We review metabotropic glutamate receptor molecular pharmacology and highlight emerging areas that are offering new avenues to selectively modulate neurotransmission.
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Affiliation(s)
- Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
| | - Cyril Goudet
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
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5
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Ricart-Ortega M, Berizzi AE, Pereira V, Malhaire F, Catena J, Font J, Gómez-Santacana X, Muñoz L, Zussy C, Serra C, Rovira X, Goudet C, Llebaria A. Mechanistic Insights into Light-Driven Allosteric Control of GPCR Biological Activity. ACS Pharmacol Transl Sci 2020; 3:883-895. [PMID: 33073188 DOI: 10.1021/acsptsci.0c00054] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Indexed: 12/31/2022]
Abstract
G protein-coupled receptors (GPCR), including the metabotrobic glutamate 5 receptor (mGlu5), are important therapeutic targets and the development of allosteric ligands for targeting GPCRs has become a desirable approach toward modulating receptor activity. Traditional pharmacological approaches toward modulating GPCR activity are still limited since precise spatiotemporal control of a ligand is lost as soon as it is administered. Photopharmacology proposes the use of photoswitchable ligands to overcome this limitation, since their activity can be reversibly controlled by light with high precision. As this is still a growing field, our understanding of the molecular mechanisms underlying the light-induced changes of different photoswitchable ligand pharmacology is suboptimal. For this reason, we have studied the mechanisms of action of alloswitch-1 and MCS0331; two freely diffusible, mGlu5 phenylazopyridine photoswitchable negative allosteric modulators. We combined photochemical, cell-based, and in vivo photopharmacological approaches to investigate the effects of trans-cis azobenzene photoisomerization on the functional activity and binding ability of these ligands to the mGlu5 allosteric pocket. From these results, we conclude that photoisomerization can take place inside and outside the ligand binding pocket, and this leads to a reversible loss in affinity, in part, due to changes in dissociation rates from the receptor. Ligand activity for both photoswitchable ligands deviates from high-affinity mGlu5 negative allosteric modulation (in the trans configuration) to reduced affinity for the mGlu5 in their cis configuration. Importantly, this mechanism translates to dynamic and reversible control over pain following local injection and illumination of negative allosteric modulators into a brain region implicated in pain control.
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Affiliation(s)
- Maria Ricart-Ortega
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain.,IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | - Alice E Berizzi
- IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | - Vanessa Pereira
- IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | - Fanny Malhaire
- IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | - Juanlo Catena
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain
| | - Joan Font
- IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | | | - Lourdes Muñoz
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain
| | - Charleine Zussy
- IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | - Carmen Serra
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain
| | - Xavier Rovira
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain
| | - Cyril Goudet
- IGF, CNRS, INSERM, University of Montpellier, F-34094 Montpellier, France
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain
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6
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Structure-based discovery and development of metabotropic glutamate receptor 5 negative allosteric modulators. ADVANCES IN PHARMACOLOGY 2020; 88:35-58. [PMID: 32416871 DOI: 10.1016/bs.apha.2020.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
The metabotropic glutamate (mGlu) receptors are a family of eight class C G protein-coupled receptors (GPCRs) which modulate cell signaling and synaptic transmission to the major excitatory neurotransmitter l-glutamate (l-glutamic acid). Due to their role in modulating glutamate response, their widespread distribution in the central nervous system (CNS) and some evidence of dysregulation in disease, the mGlu receptors have become attractive pharmacological targets. As the orthosteric (glutamate) binding site is highly conserved across the eight mGlu receptors, it is difficult not only to generate ligands with subtype selectivity but, due to the nature of the binding site, with suitable drug-like properties to allow oral bioavailability and CNS penetration. Selective pharmacological targeting of a single receptor subtype can be achieved by targeting alternative (allosteric) binding sites. The nature of the allosteric binding pockets allows ligands to be developed that have good physical chemical properties as evidenced by several allosteric modulators of mGlu receptors entering clinical trials. The first negative allosteric modulators of the metabotropic glutamate 5 (mGlu5) receptor were discovered from high throughput screening activities. An alternative approach to drug discovery is to use structural knowledge to enable structure-based drug design (SBDD), which allows the design of molecules in a more rational, rather than empirical, fashion. Here we will describe the process of SBDD in the discovery of the mGlu5 negative allosteric modulator HTL0014242 and describe how knowledge of receptor structure can also be used to gain insights into the receptor activation mechanisms.
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7
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Kenakin T. Prescient Indices of Activity: The Application of Functional System Sensitivity to Measurement of Drug Effect. Trends Pharmacol Sci 2019; 40:529-539. [PMID: 31109799 DOI: 10.1016/j.tips.2019.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 01/06/2023]
Abstract
Through pharmacological procedures, indices of drug activity can be obtained that transcend the systems in which they are measured. If (i) affinity, (ii) efficacies, (iii) orthosteric versus allosteric interaction, and (iv) rate of receptor offset can be determined, activity can be predicted in all systems. This can yield more detailed profiles (fingerprints) of efficacy to better define the required activities of follow-up molecules should the original candidates fail in the clinic. The use of functional assays of varying sensitivity is a major tool in the lead optimization process and the observation of candidate molecule profiles in multiple functional assays can reveal all properties of candidate molecules. In this review, the different indices for agonists, antagonists, and allosteric modulators are defined while highlighting the application of functional assays in deriving these indices.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, 120 Mason Farm Road, Room 4042 Genetic Medicine Building, CB# 7365, Chapel Hill, NC 27599-7365, USA.
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8
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9
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Koehl A, Hu H, Feng D, Sun B, Zhang Y, Robertson MJ, Chu M, Kobilka TS, Laeremans T, Steyaert J, Tarrasch J, Dutta S, Fonseca R, Weis WI, Mathiesen JM, Skiniotis G, Kobilka BK. Structural insights into the activation of metabotropic glutamate receptors. Nature 2019; 566:79-84. [PMID: 30675062 PMCID: PMC6709600 DOI: 10.1038/s41586-019-0881-4] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/12/2018] [Indexed: 12/11/2022]
Abstract
Metabotropic glutamate receptors are family C G-protein-coupled receptors. They form obligate dimers and possess extracellular ligand-binding Venus flytrap domains, which are linked by cysteine-rich domains to their 7-transmembrane domains. Spectroscopic studies show that signalling is a dynamic process, in which large-scale conformational changes underlie the transmission of signals from the extracellular Venus flytraps to the G protein-coupling domains-the 7-transmembrane domains-in the membrane. Here, using a combination of X-ray crystallography, cryo-electron microscopy and signalling studies, we present a structural framework for the activation mechanism of metabotropic glutamate receptor subtype 5. Our results show that agonist binding at the Venus flytraps leads to a compaction of the intersubunit dimer interface, thereby bringing the cysteine-rich domains into close proximity. Interactions between the cysteine-rich domains and the second extracellular loops of the receptor enable the rigid-body repositioning of the 7-transmembrane domains, which come into contact with each other to initiate signalling.
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Affiliation(s)
- Antoine Koehl
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Hongli Hu
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Dan Feng
- ConfometRx, Santa Clara, CA, USA
| | | | - Yan Zhang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Michael J Robertson
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Tong Sun Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,ConfometRx, Santa Clara, CA, USA
| | - Toon Laeremans
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jeffrey Tarrasch
- Life Sciences Institute and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Somnath Dutta
- Life Sciences Institute and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.,Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Rasmus Fonseca
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,Biosciences Division, SLAC National Accelerator Laboratory, Stanford University, Stanford, CA, USA
| | - William I Weis
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jesper M Mathiesen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Georgios Skiniotis
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA. .,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA. .,ConfometRx, Santa Clara, CA, USA.
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10
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Biased agonism and allosteric modulation of metabotropic glutamate receptor 5. Clin Sci (Lond) 2018; 132:2323-2338. [PMID: 30389826 DOI: 10.1042/cs20180374] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 12/18/2022]
Abstract
Metabotropic glutamate receptors belong to class C G-protein-coupled receptors and consist of eight subtypes that are ubiquitously expressed throughout the central nervous system. In recent years, the metabotropic glutamate receptor subtype 5 (mGlu5) has emerged as a promising target for a broad range of psychiatric and neurological disorders. Drug discovery programs targetting mGlu5 are primarily focused on development of allosteric modulators that interact with sites distinct from the endogenous agonist glutamate. Significant efforts have seen mGlu5 allosteric modulators progress into clinical trials; however, recent failures due to lack of efficacy or adverse effects indicate a need for a better understanding of the functional consequences of mGlu5 allosteric modulation. Biased agonism is an interrelated phenomenon to allosterism, describing how different ligands acting through the same receptor can differentially influence signaling to distinct transducers and pathways. Emerging evidence demonstrates that allosteric modulators can induce biased pharmacology at the level of intrinsic agonism as well as through differential modulation of orthosteric agonist-signaling pathways. Here, we present key considerations in the discovery and development of mGlu5 allosteric modulators and the opportunities and pitfalls offered by biased agonism and modulation.
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11
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Doornbos ML, Vermond SC, Lavreysen H, Tresadern G, IJzerman AP, Heitman LH. Impact of allosteric modulation: Exploring the binding kinetics of glutamate and other orthosteric ligands of the metabotropic glutamate receptor 2. Biochem Pharmacol 2018; 155:356-365. [DOI: 10.1016/j.bcp.2018.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/14/2018] [Indexed: 01/22/2023]
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12
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PAM-Antagonists: A Better Way to Block Pathological Receptor Signaling? Trends Pharmacol Sci 2018; 39:748-765. [PMID: 29885909 DOI: 10.1016/j.tips.2018.05.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022]
Abstract
Seven transmembrane receptor (7TMR) responses are modulated by orthosteric and allosteric ligands to great therapeutic advantage. Here we introduce a unique class of negative allosteric modulator (NAM) - the positive allosteric modulator (PAM)-antagonist - that increases the affinity of the receptor for the agonist but concomitantly decreases agonist efficacy when cobound. Notably, the reciprocation of allosteric energy causes the orthosteric agonist to increase the affinity of the receptor for the PAM-antagonist; thus, this modulator seeks out and destroys agonist-bound receptor complexes. When contrasted with standard orthosteric and allosteric antagonists it is clear that PAM-antagonists are uniquely well suited to reversing ongoing persistent agonism and provide favorable target coverage in vivo. Specifically, the therapeutic application of PAM-antagonists to reverse pathological overactivation (e.g., endothelin vasoconstriction) is emphasized.
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13
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Beggiato S, Borelli AC, Tomasini MC, Castelli MP, Pintori N, Cacciaglia R, Loche A, Ferraro L. In Vitro Functional Characterization of GET73 as Possible Negative Allosteric Modulator of Metabotropic Glutamate Receptor 5. Front Pharmacol 2018; 9:327. [PMID: 29674969 PMCID: PMC5895880 DOI: 10.3389/fphar.2018.00327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 03/21/2018] [Indexed: 01/08/2023] Open
Abstract
The present study was aimed to further characterize the pharmacological profile of N-[4-(trifluoromethyl) benzyl]-4-methoxybutyramide (GET73), a putative negative allosteric modulator (NAM) of metabotropic glutamate subtype 5 receptor (mGluR5) under development as a novel medication for the treatment of alcohol dependence. This aim has been accomplished by means of a series of in vitro functional assays. These assays include the measure of several down-stream signaling [intracellular Ca++ levels, inositol phosphate (IP) formation and CREB phosphorylation (pCREB)] which are generally affected by mGluR5 ligands. In particular, GET73 (0.1 nM-10 μM) was explored for its ability to displace the concentration-response curve of some mGluR5 agonists/probes (glutamate, L-quisqualate, CHPG) in different native preparations. GET73 produced a rightward shift of concentration-response curves of glutamate- and CHPG-induced intracellular Ca++ levels in primary cultures of rat cortical astrocytes. The compound also induced a rightward shift of concentration response curve of glutamate- and L-quisqualate-induced increase in IP turnover in rat hippocampus slices, along with a reduction of CHPG (10 mM)-induced increase in IP formation. Moreover, GET73 produced a rightward shift of concentration-response curve of glutamate-, CHPG- and L-quisqualate-induced pCREB levels in rat cerebral cortex neurons. Although the engagement of other targets cannot be definitively ruled out, these data support the view that GET73 acts as an mGluR5 NAM and support the significance of further investigating the possible mechanism of action of the compound.
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Affiliation(s)
- Sarah Beggiato
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,IRET Foundation, Bologna, Italy
| | - Andrea C Borelli
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,IRET Foundation, Bologna, Italy
| | - Maria C Tomasini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,IRET Foundation, Bologna, Italy
| | - M Paola Castelli
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.,Center of Excellence "Neurobiology of Addiction", University of Cagliari, Cagliari, Italy
| | - Nicholas Pintori
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | | | | | - Luca Ferraro
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,IRET Foundation, Bologna, Italy.,LTTA Centre, University of Ferrara, Ferrara, Italy
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14
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O'Brien DE, Shaw DM, Cho HP, Cross AJ, Wesolowski SS, Felts AS, Bergare J, Elmore CS, Lindsley CW, Niswender CM, Conn PJ. Differential Pharmacology and Binding of mGlu 2 Receptor Allosteric Modulators. Mol Pharmacol 2018; 93:526-540. [PMID: 29545267 DOI: 10.1124/mol.117.110114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 03/12/2018] [Indexed: 01/01/2023] Open
Abstract
Allosteric modulation of metabotropic glutamate receptor 2 (mGlu2) has demonstrated efficacy in preclinical rodent models of several brain disorders, leading to industry and academic drug discovery efforts. Although the pharmacology and binding sites of some mGlu2 allosteric modulators have been characterized previously, questions remain about the nature of the allosteric mechanism of cooperativity with glutamate and whether structurally diverse allosteric modulators bind in an identical manner to specific allosteric sites. To further investigate the in vitro pharmacology of mGlu2 allosteric modulators, we developed and characterized a novel mGlu2 positive allosteric modulator (PAM) radioligand in parallel with functional studies of a structurally diverse set of mGlu2 PAMs and negative allosteric modulators (NAMs). Using an operational model of allosterism to analyze the functional data, we found that PAMs affect both the affinity and efficacy of glutamate at mGlu2, whereas NAMs predominantly affect the efficacy of glutamate in our assay system. More importantly, we found that binding of a novel mGlu2 PAM radioligand was inhibited by multiple structurally diverse PAMs and NAMs, indicating that they may bind to the mGlu2 allosteric site labeled with the novel mGlu2 PAM radioligand; however, further studies suggested that these allosteric modulators do not all interact with the radioligand in an identical manner. Together, these findings provide new insights into the binding sites and modes of efficacy of different structurally and functionally distinct mGlu2 allosteric modulators and suggest that different ligands either interact with distinct sites or adapt different binding poses to shared allosteric site(s).
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Affiliation(s)
- Daniel E O'Brien
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Douglas M Shaw
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Hyekyung P Cho
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Alan J Cross
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Steven S Wesolowski
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Andrew S Felts
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Jonas Bergare
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Charles S Elmore
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
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15
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Hellyer SD, Albold S, Wang T, Chen ANY, May LT, Leach K, Gregory KJ. “Selective” Class C G Protein-Coupled Receptor Modulators Are Neutral or Biased mGlu5 Allosteric Ligands. Mol Pharmacol 2018. [DOI: 10.1124/mol.117.111518] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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16
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Abstract
INTRODUCTION The availability of different functional pharmacological assays has revealed that agonists for receptors that are pleiotropically coupled to multiple signaling pathways in the cell can emphasize signals to some pathways over others, i.e. can be biased toward certain signals. This, in turn, opens the possibility that molecules can be made to emphasize favorable signals, de-emphasize harmful signals or selectively block the ability of the natural agonist to produce unfavorable signals. Areas covered: This paper discusses the mechanism of biased signaling, the possible therapeutic implications of this effect, methods to quantify and measure bias and the current literature describing the translation of biased measure in vitro to in vivo systems. In addition, the challenges of exploiting this mechanism for therapy are outlined. Expert opinion: While this mechanism is well established and ubiquitous in pharmacology and easily measured in vitro, there are theoretical and practical hurdles to overcome to the fruitful utilization of signaling bias in therapeutic systems. There will be failures in the translation of biased molecules in vivo because of these challenges but hopefully also success and these latter translations hopefully will provide guidance in exploiting this effect further for therapy.
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Affiliation(s)
- Terry Kenakin
- a Department of Pharmacology , University of North Carolina School of Medicine , Chapel Hill , NC , USA
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17
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Leach K, Gregory KJ. Molecular insights into allosteric modulation of Class C G protein-coupled receptors. Pharmacol Res 2017; 116:105-118. [DOI: 10.1016/j.phrs.2016.12.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 11/18/2016] [Accepted: 12/07/2016] [Indexed: 12/23/2022]
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18
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Berizzi AE, Gentry PR, Rueda P, Den Hoedt S, Sexton PM, Langmead CJ, Christopoulos A. Molecular Mechanisms of Action of M5 Muscarinic Acetylcholine Receptor Allosteric Modulators. Mol Pharmacol 2016; 90:427-36. [DOI: 10.1124/mol.116.104182] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/18/2016] [Indexed: 11/22/2022] Open
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19
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Chen YY, Yu YN, Zhang YY, Li B, Liu J, Li DF, Wu P, Wang J, Wang Z, Wang YY. Quantitative Determination of Flexible Pharmacological Mechanisms Based On Topological Variation in Mice Anti-Ischemic Modular Networks. PLoS One 2016; 11:e0158379. [PMID: 27383195 PMCID: PMC4934924 DOI: 10.1371/journal.pone.0158379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/12/2016] [Indexed: 12/29/2022] Open
Abstract
Targeting modules or signalings may open a new path to understanding the complex pharmacological mechanisms of reversing disease processes. However, determining how to quantify the structural alteration of these signalings or modules in pharmacological networks poses a great challenge towards realizing rational drug use in clinical medicine. Here, we explore a novel approach for dynamic comparative and quantitative analysis of the topological structural variation of modules in molecular networks, proposing the concept of allosteric modules (AMs). Based on the ischemic brain of mice, we optimize module distribution in different compound-dependent modular networks by using the minimum entropy criterion and then calculate the variation in similarity values of AMs under various conditions using a novel method of SimiNEF. The diverse pharmacological dynamic stereo-scrolls of AMs with functional gradient alteration, which consist of five types of AMs, may robustly deconstruct modular networks under the same ischemic conditions. The concept of AMs can not only integrate the responsive mechanisms of different compounds based on topological cascading variation but also obtain valuable structural information about disease and pharmacological networks beyond pathway analysis. We thereby provide a new systemic quantitative strategy for rationally determining pharmacological mechanisms of altered modular networks based on topological variation.
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Affiliation(s)
- Yin-ying Chen
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Ya-nan Yu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Ying-ying Zhang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Bing Li
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jun Liu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Dong-feng Li
- School of Mathematical Sciences, Peking University, Beijing, China
| | - Ping Wu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jie Wang
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- * E-mail: (JW); (ZW); (YYW)
| | - Zhong Wang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
- * E-mail: (JW); (ZW); (YYW)
| | - Yong-yan Wang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
- * E-mail: (JW); (ZW); (YYW)
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20
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Zhang B, Chen R, Jiang H, Zhou Q, Qiu F, Han D, Li R, Tang W, Zhong A, Zhang J, Yu X. Palladium-catalyzed highly regioselective 2-alkynylation of 2,x-dihalopyridines. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.03.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Abstract
Over the past 50 years in pharmacology, an understanding of seven transmembrane (7TMR) function has been gained from the comparison of experimental data to receptor models. These models have been constructed from building blocks composed of systems consisting of series and parallel mass action binding reactions. Basic functions such as the the isomerization of receptors upon ligand binding, the sequential binding of receptors to membrane coupling proteins, and the selection of multiple receptor conformations have been combined in various ways to build receptor systems such as the ternary complex, extended ternary complex, and cubic ternary complex models for 7TMR function. Separately, the Black/Leff operational model has furnished an extremely valuable method of quantifying drug agonism. In the past few years, incorporation of the basic allosteric nature of 7TMRs has led to additional useful models of functional receptor allosteric mechanisms; these models yield valuable methods for quantifying allosteric effects. Finally, molecular dynamics has provided yet another new set of models describing the probability of formation of multiple receptor states; these radically new models are extremely useful in the prediction of functionally selective drug effects.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine , 120 Mason Farm Road, Room 4042, Genetic Medicine Building, CB# 7365, Chapel Hill, North Carolina 27599-7365, United States
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22
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Sengmany K, Gregory KJ. Metabotropic glutamate receptor subtype 5: molecular pharmacology, allosteric modulation and stimulus bias. Br J Pharmacol 2015; 173:3001-17. [PMID: 26276909 DOI: 10.1111/bph.13281] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/30/2015] [Accepted: 07/26/2015] [Indexed: 12/12/2022] Open
Abstract
The metabotropic glutamate receptor subtype 5 (mGlu5 ) is a family C GPCR that has been implicated in various neuronal processes and, consequently, in several CNS disorders. Over the past few decades, GPCR-based drug discovery, including that for mGlu5 receptors, has turned considerable attention to targeting allosteric binding sites. Modulation of endogenous agonists by allosteric ligands offers the advantages of spatial and temporal fine-tuning of receptor activity, increased selectivity and reduced adverse effects with the potential to elicit improved clinical outcomes. Further, with greater appreciation of the multifaceted nature of the transduction of mGlu5 receptor signalling, it is increasingly apparent that drug discovery must take into consideration unique receptor conformations and the potential for stimulus-bias. This novel paradigm proposes that different ligands may differentially modulate distinct signalling pathways arising from the same receptor. We review our current understanding of the complexities of mGlu5 receptor signalling and regulation, and how these relate to allosteric ligands. Ultimately, a deeper appreciation of these relationships will provide the foundation for targeted drug design of compounds with increased selectivity, not only for the desired receptor but also for the desired signalling outcome from the receptor. Linked Articles This article is part of a themed section on Molecular Pharmacology of G Protein-Coupled Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.20/issuetoc.
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Affiliation(s)
- K Sengmany
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - K J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, VIC, Australia.
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23
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Nickols HH, Yuh JP, Gregory KJ, Morrison RD, Bates BS, Stauffer SR, Emmitte KA, Bubser M, Peng W, Nedelcovych MT, Thompson A, Lv X, Xiang Z, Daniels JS, Niswender CM, Lindsley CW, Jones CK, Conn PJ. VU0477573: Partial Negative Allosteric Modulator of the Subtype 5 Metabotropic Glutamate Receptor with In Vivo Efficacy. J Pharmacol Exp Ther 2015; 356:123-36. [PMID: 26503377 DOI: 10.1124/jpet.115.226597] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/23/2015] [Indexed: 12/16/2022] Open
Abstract
Negative allosteric modulators (NAMs) of metabotropic glutamate receptor subtype 5 (mGlu5) have potential applications in the treatment of fragile X syndrome, levodopa-induced dyskinesia in Parkinson disease, Alzheimer disease, addiction, and anxiety; however, clinical and preclinical studies raise concerns that complete blockade of mGlu5 and inverse agonist activity of current mGlu5 NAMs contribute to adverse effects that limit the therapeutic use of these compounds. We report the discovery and characterization of a novel mGlu5 NAM, N,N-diethyl-5-((3-fluorophenyl)ethynyl)picolinamide (VU0477573) that binds to the same allosteric site as the prototypical mGlu5 NAM MPEP but displays weak negative cooperativity. Because of this weak cooperativity, VU0477573 acts as a "partial NAM" so that full occupancy of the MPEP site does not completely inhibit maximal effects of mGlu5 agonists on intracellular calcium mobilization, inositol phosphate (IP) accumulation, or inhibition of synaptic transmission at the hippocampal Schaffer collateral-CA1 synapse. Unlike previous mGlu5 NAMs, VU0477573 displays no inverse agonist activity assessed using measures of effects on basal [(3)H]inositol phosphate (IP) accumulation. VU0477573 acts as a full NAM when measuring effects on mGlu5-mediated extracellular signal-related kinases 1/2 phosphorylation, which may indicate functional bias. VU0477573 exhibits an excellent pharmacokinetic profile and good brain penetration in rodents and provides dose-dependent full mGlu5 occupancy in the central nervous system (CNS) with systemic administration. Interestingly, VU0477573 shows robust efficacy, comparable to the mGlu5 NAM MTEP, in models of anxiolytic activity at doses that provide full CNS occupancy of mGlu5 and demonstrate an excellent CNS occupancy-efficacy relationship. VU0477573 provides an exciting new tool to investigate the efficacy of partial NAMs in animal models.
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Affiliation(s)
- Hilary Highfield Nickols
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Joannes P Yuh
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Karen J Gregory
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Ryan D Morrison
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Brittney S Bates
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Shaun R Stauffer
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Kyle A Emmitte
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Michael Bubser
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Weimin Peng
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Michael T Nedelcovych
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Analisa Thompson
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Xiaohui Lv
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Zixiu Xiang
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - J Scott Daniels
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Colleen M Niswender
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Craig W Lindsley
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - Carrie K Jones
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
| | - P Jeffrey Conn
- Department of Pathology, Microbiology and Immunology, Division of Neuropathology (H.H.N., J.P.Y.), Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery (H.H.N., R.D.M., B.S.B., K.A.E., M.B., W.P., M.T.N., A.T., X.L., Z.X., J.S.D., C.M.N., C.W.L., C.K.J., P.J.C.), Department of Chemistry and Vanderbilt Institute of Chemical Biology (S.R.S., K.A.E., C.W.L.) Vanderbilt University Medical Center, Nashville, Tennessee; and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.)
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24
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Plasticity of Neuron-Glial Transmission: Equipping Glia for Long-Term Integration of Network Activity. Neural Plast 2015; 2015:765792. [PMID: 26339509 PMCID: PMC4539116 DOI: 10.1155/2015/765792] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/11/2015] [Indexed: 01/28/2023] Open
Abstract
The capacity of synaptic networks to express activity-dependent changes in strength and connectivity is essential for learning and memory processes. In recent years, glial cells (most notably astrocytes) have been recognized as active participants in the modulation of synaptic transmission and synaptic plasticity, implicating these electrically nonexcitable cells in information processing in the brain. While the concept of bidirectional communication between neurons and glia and the mechanisms by which gliotransmission can modulate neuronal function are well established, less attention has been focussed on the computational potential of neuron-glial transmission itself. In particular, whether neuron-glial transmission is itself subject to activity-dependent plasticity and what the computational properties of such plasticity might be has not been explored in detail. In this review, we summarize current examples of plasticity in neuron-glial transmission, in many brain regions and neurotransmitter pathways. We argue that induction of glial plasticity typically requires repetitive neuronal firing over long time periods (minutes-hours) rather than the short-lived, stereotyped trigger typical of canonical long-term potentiation. We speculate that this equips glia with a mechanism for monitoring average firing rates in the synaptic network, which is suited to the longer term roles proposed for astrocytes in neurophysiology.
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25
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Kenakin T. Gaddum Memorial Lecture 2014: receptors as an evolving concept: from switches to biased microprocessors. Br J Pharmacol 2015; 172:4238-53. [PMID: 26075971 DOI: 10.1111/bph.13217] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/06/2015] [Accepted: 03/16/2015] [Indexed: 12/17/2022] Open
Abstract
This review is based on the JR Vane Medal Lecture presented at the BPS Winter Meeting in December 2014 by T. Kenakin. A recording of the lecture is included as supporting information and can also be viewed online here: https://www.youtube.com/watch?v=xrP81AQ8l-8. Pharmacological models used to describe drug agonism and antagonism have evolved over the past 20 years from a parsimonious model describing single active and inactive receptor states to models of multiconformational receptor systems modified by ligand conformational selection. These latter models describe the observed, presently underexploited, pharmacological mechanism of ligand-directed biased signalling. Biased signals can be quantified with transduction coefficients (ΔΔLog(τ/KA) values), a scale grounded in the Black/Leff operational model; this enables the optimization of biased profiles through medicinal chemistry. The past decades have also brought the availability of new technologies to measure multiple functional effects mediated by seven transmembrane receptors. These have confirmed that drugs can have many efficacies, which may be collaterally linked, that is there is no linear sequence of activities required. In addition, new functional screening assays have introduced increasing numbers of allosteric ligands into drug discovery. These molecules are permissive (they do not necessarily preclude endogenous signalling in vivo); therefore, they may allow better fine tuning of pathological physiology. The permissive quality of allosteric ligands can also change the quality of endogenous signalling efficacy ('induced bias') as well as the quantity of signal; in this regard, indices related to ΔΔLog(τ/KA) values (namely ΔLog(αβ) values) can be used to quantify these effects for optimization in the drug discovery process. All of these added scales of drug activity will, hopefully, allow better targeting of candidate molecules towards therapies.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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26
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Kenakin T. The Effective Application of Biased Signaling to New Drug Discovery. Mol Pharmacol 2015; 88:1055-61. [PMID: 26138073 DOI: 10.1124/mol.115.099770] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 07/02/2015] [Indexed: 01/14/2023] Open
Abstract
The ability of agonists to selectively activate some but not all signaling pathways linked to pleiotropically signaling receptors has opened the possibility of obtaining molecules that emphasize beneficial signals, de-emphasize harmful signals, and concomitantly deemphasize harmful signals while blocking the harmful signals produced by endogenous agonists. The detection and quantification of biased effects is straightforward, but two important factors should be considered in the evaluation of biased effects in drug discovery. The first is that efficacy, and not bias, determines whether a given agonist signal will be observed; bias only dictates the relative concentrations at which agonist signals will appear when they do appear. Therefore, a Cartesian coordinate system plotting relative efficacy (on a scale of Log relative Intrinsic Activities) as the ordinates and Log(bias) as the abscissae is proposed as a useful tool in evaluating possible biased molecules for progression in discovery programs. Second, it should be considered that the current scales quantifying bias limit this property to the allosteric vector (ligand/receptor/coupling protein complex) and that whole-cell processing of this signal can completely change measured bias from in vitro predictions.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
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27
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Gregory KJ, Conn PJ. Molecular Insights into Metabotropic Glutamate Receptor Allosteric Modulation. Mol Pharmacol 2015; 88:188-202. [PMID: 25808929 DOI: 10.1124/mol.114.097220] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/24/2015] [Indexed: 12/21/2022] Open
Abstract
The metabotropic glutamate (mGlu) receptors are a group of eight family C G protein-coupled receptors that are expressed throughout the central nervous system (CNS) and periphery. Within the CNS the different subtypes are found in neurons, both pre- and/or postsynaptically, where they mediate modulatory roles and in glial cells. The mGlu receptor family provides attractive targets for numerous psychiatric and neurologic disorders, with the majority of discovery programs focused on targeting allosteric sites, with allosteric ligands now available for all mGlu receptor subtypes. However, the development of allosteric ligands remains challenging. Biased modulation, probe dependence, and molecular switches all contribute to the complex molecular pharmacology exhibited by mGlu receptor allosteric ligands. In recent years we have made significant progress in our understanding of this molecular complexity coupled with an increased understanding of the structural basis of mGlu allosteric modulation.
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Affiliation(s)
- Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Vanderbilt Center for Neuroscience Drug Discovery & Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C)
| | - P Jeffrey Conn
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Vanderbilt Center for Neuroscience Drug Discovery & Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C)
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28
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Leach K, Conigrave AD, Sexton PM, Christopoulos A. Towards tissue-specific pharmacology: insights from the calcium-sensing receptor as a paradigm for GPCR (patho)physiological bias. Trends Pharmacol Sci 2015; 36:215-25. [PMID: 25765207 DOI: 10.1016/j.tips.2015.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 12/25/2022]
Abstract
The calcium-sensing receptor (CaSR) is a widely expressed G protein-coupled receptor (GPCR) that mediates numerous tissue-specific functions. Its multiple ligands and diverse roles attest to the need for exquisite control over the signaling pathways that mediate its effects. 'Biased signaling' is the phenomenon by which distinct ligands stabilize preferred receptor signaling states. The CaSR is subject to biased signaling in response to its endogenous ligands. Interestingly, the 'natural' bias of the CaSR is altered in disease states, and small molecule drugs engender biased allosteric modulation of downstream signaling pathways. Thus, biased signaling from the CaSR also has important implications pathophysiologically and therapeutically. As outlined in this review, this novel paradigm extends to other GPCRs, making the CaSR a model for studies of ligand-biased signaling and for understanding how it may be used to foster selective drug activity in different tissues.
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Affiliation(s)
- Katie Leach
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville VIC, Australia.
| | - Arthur D Conigrave
- School of Molecular Bioscience, Charles Perkins Centre, University of Sydney, NSW 2006, Australia
| | - Patrick M Sexton
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville VIC, Australia
| | - Arthur Christopoulos
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville VIC, Australia
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Roche D, Gil D, Giraldo J. Mechanistic analysis of the function of agonists and allosteric modulators: reconciling two-state and operational models. Br J Pharmacol 2014; 169:1189-202. [PMID: 23647200 DOI: 10.1111/bph.12231] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 11/30/2022] Open
Abstract
Two-state and operational models of both agonism and allosterism are compared to identify and characterize common pharmacological parameters. To account for the receptor-dependent basal response, constitutive receptor activity is considered in the operational models. By arranging two-state models as the fraction of active receptors and operational models as the fractional response relative to the maximum effect of the system, a one-by-one correspondence between parameters is found. The comparative analysis allows a better understanding of complex allosteric interactions. In particular, the inclusion of constitutive receptor activity in the operational model of allosterism allows the characterization of modulators able to lower the basal response of the system; that is, allosteric modulators with negative intrinsic efficacy. Theoretical simulations and overall goodness of fit of the models to simulated data suggest that it is feasible to apply the models to experimental data and constitute one step forward in receptor theory formalism.
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Affiliation(s)
- David Roche
- Laboratory of Systems Pharmacology and Bioinformatics, Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Bellaterra, Spain
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30
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Christopoulos A. Advances in G protein-coupled receptor allostery: from function to structure. Mol Pharmacol 2014; 86:463-78. [PMID: 25061106 DOI: 10.1124/mol.114.094342] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It is now widely accepted that G protein-coupled receptors (GPCRs) are highly dynamic proteins that adopt multiple active states linked to distinct functional outcomes. Furthermore, these states can be differentially stabilized not only by orthosteric ligands but also by allosteric ligands acting at spatially distinct binding sites. The key pharmacologic characteristics of GPCR allostery include improved selectivity due to either greater sequence divergence between receptor subtypes and/or subtype-selective cooperativity, a ceiling level to the effect, probe dependence (whereby the magnitude and direction of the allosteric effect change with the nature of the interacting ligands), and the potential for biased signaling. Recent chemical biology developments are beginning to demonstrate how the incorporation of analytical pharmacology and operational modeling into the experimental workflow can enrich structure-activity studies of allostery and bias, and have also led to the discovery of a new class of hybrid orthosteric/allosteric (bitopic) molecules. The potential for endogenous allosteric modulators to play a role in physiology and disease remains to be fully appreciated but will likely represent an important area for future studies. Finally, breakthroughs in structural and computational biology are beginning to unravel the mechanistic basis of GPCR allosteric modulation at the molecular level.
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Affiliation(s)
- Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
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31
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Functional and structural perspectives on allosteric modulation of GPCRs. Curr Opin Cell Biol 2014; 27:94-101. [DOI: 10.1016/j.ceb.2013.11.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 11/21/2013] [Accepted: 11/21/2013] [Indexed: 11/22/2022]
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32
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Noetzel MJ, Gregory KJ, Vinson PN, Manka JT, Stauffer SR, Lindsley CW, Niswender CM, Xiang Z, Conn PJ. A novel metabotropic glutamate receptor 5 positive allosteric modulator acts at a unique site and confers stimulus bias to mGlu5 signaling. Mol Pharmacol 2013; 83:835-47. [PMID: 23348500 DOI: 10.1124/mol.112.082891] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Metabotropic glutamate receptor 5 (mGlu5) is a target for the treatment of central nervous system (CNS) disorders, such as schizophrenia and Alzheimer's disease. Furthermore, mGlu5 has been shown to play an important role in hippocampal synaptic plasticity, specifically in long-term depression (LTD) and long-term potentiation (LTP), which is thought to be involved in cognition. Multiple mGlu5-positive allosteric modulators (PAMs) have been developed from a variety of different scaffolds. Previous work has extensively characterized a common allosteric site on mGlu5, termed the MPEP (2-Methyl-6-(phenylethynyl)pyridine) binding site. However, one mGlu5 PAM, CPPHA (N-(4-chloro-2-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]phenyl)-2-hydroxybenzamide), interacts with a separate allosteric site on mGlu5. Using cell-based assays and brain slice preparations, we characterized the interaction of a potent and efficacious mGlu5 PAM from the CPPHA series termed NCFP (N-(4-chloro-2-((4-fluoro-1,3-dioxoisoindolin-2-yl)methyl)phenyl)picolinamide). NCFP binds to the CPPHA site on mGlu5 and potentiates mGlu5-mediated responses in both recombinant and native systems. However, NCFP provides greater mGlu5 subtype selectivity than does CPPHA, making it more suitable for studies of effects on mGlu5 in CNS preparations. Of interest, NCFP does not potentiate responses involved in hippocampal synaptic plasticity (LTD/LTP), setting it apart from other previously characterized MPEP site PAMs. This suggests that although mGlu5 PAMs may have similar responses in some systems, they can induce differential effects on mGlu5-mediated physiologic responses in the CNS. Such stimulus bias by mGlu5 PAMs may complicate drug discovery efforts but would also allow for specifically tailored therapies, if pharmacological biases can be attributed to different therapeutic outcomes.
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Affiliation(s)
- M J Noetzel
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN, USA
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33
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Bindslev N. Allosteric transition: a comparison of two models. BMC Pharmacol Toxicol 2013; 14:4. [PMID: 23298758 PMCID: PMC3599370 DOI: 10.1186/2050-6511-14-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 12/10/2012] [Indexed: 11/10/2022] Open
Abstract
Introduction Two recent models are in use for analysis of allosteric drug action at receptor sites remote from orthosteric binding sites. One is an allosteric two-state mechanical model derived in 2000 by David Hall. The other is an extended operational model developed in 2007 by Arthur Christopoulos’s group. The models are valid in pharmacology, enzymology, transportology as well as several other fields of biology involving allosteric concentration effects. Results I show here that Hall’s model for interactions between an orthoster, an alloster, and a receptive unit is the best choice of model both for simulation and analysis of allosteric concentration-responses at equilibrium or steady-state. Conclusions As detailed knowledge of receptors systems becomes available, systems with several pathways and states and/ or more than two binding sites should be analysed by extended forms of the Hall model rather than for instance a Hill type exponentiation of terms as introduced in non-mechanistic (operational) model approaches; yielding semi-quantitative estimates of actual system parameters based on Hill’s unlikely simultaneity model for G protein-coupled receptors.
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Affiliation(s)
- Niels Bindslev
- Synagics Lab, Endocrinology Section, Department of Biomedical Sciences, The Medical Faculty, Panum Building, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.
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34
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Metabotropic glutamate receptor 5-positive allosteric modulators for the treatment of schizophrenia (2004–2012). Pharm Pat Anal 2013; 2:93-108. [DOI: 10.4155/ppa.12.82] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The mGlu5, a class C G-protein-coupled receptor and member of the group I mGlu receptor family, has been demonstrated to play a role in a number of therapeutic areas within the CNS, including schizophrenia, dementia, epilepsy, cognition, drug abuse, and fragile X syndrome. Small-molecule modulation of mGlu5 via positive allosteric modulators (PAMs) is being pursued as a promising approach for the treatment of schizophrenia and has been validated preclinically in a number of animal models. This article provides a brief historical overview of mGlu5 PAMs in the primary literature followed by a comprehensive overview of the patent literature since 2004. Schizophrenia is a complex disorder and although no mGlu5 PAMs have progressed into clinical trials in patients, the target continues to show promise as an attractive non-dopaminergic therapy. The successful development of mGlu5 PAMs for clinical testing must address several issues, including challenges associated with ‘molecular switches’, allosteric-agonist activity and stimulus bias.
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35
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Pharmacology of metabotropic glutamate receptor allosteric modulators: structural basis and therapeutic potential for CNS disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 115:61-121. [PMID: 23415092 DOI: 10.1016/b978-0-12-394587-7.00002-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The metabotropic glutamate receptors (mGlus) mediate a neuromodulatory role throughout the brain for the major excitatory neurotransmitter, glutamate. Seven of the eight mGlu subtypes are expressed within the CNS and are attractive targets for a variety of psychiatric and neurological disorders including anxiety, depression, schizophrenia, Parkinson's disease, and Fragile X syndrome. Allosteric modulation of these class C 7-transmembrane spanning receptors represents a novel approach to facilitate development of mGlu subtype-selective probes and therapeutics. Allosteric modulators that interact with sites topographically distinct from the endogenous ligand-binding site offer a number of advantages over their competitive counterparts. In particular for CNS therapeutics, allosteric modulators have the potential to maintain the spatial and temporal aspects of endogenous neurotransmission. The past 15 years have seen the discovery of numerous subtype-selective allosteric modulators for the majority of the mGlu family members, including positive, negative, and neutral allosteric modulators, with a number of mGlu allosteric modulators now in clinical trials.
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36
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Morrow JA, Gilfillan R, Neale SA. Glutamatergic Approaches for the Treatment of Schizophrenia. DRUG DISCOVERY FOR PSYCHIATRIC DISORDERS 2012. [DOI: 10.1039/9781849734943-00056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and plays a key role in most aspects of normal brain function including cognition, learning and memory. Dysfunction of glutamatergic neurotransmission has been implicated in a number of neurological and psychiatric disorders with a growing body of evidence suggesting that hypofunction of glutamatergic neurotransmission via the N-methyl-d-aspartate (NMDA) receptor plays an important role in the pathophysiology of schizophrenia. It thus follows that potentiation of NMDA receptor function via pharmacological manipulation may provide therapeutic utility for the treatment of schizophrenia and a number of different approaches are currently being pursued by the pharmaceutical industry with this aim in mind. These include strategies that target the glycine/d-serine site of the NMDA receptor (glycine transporter GlyT1, d-serine transporter ASC-1 and d-amino acid oxidase (DAAO) inhibitors) together with those aimed at enhancing glutamatergic neurotransmission via modulation of AMPA receptor and metabotropic glutamate receptor function. Such efforts are now beginning to bear fruit with compounds such as the GlyT1 inhibitor RG1678 and mGlu2 agonist LY2140023 proving to have clinical meaningful effects in phase II clinical trials. While more studies are required to confirm long-term efficacy, functional outcome and safety in schizophrenic agents, these agents hold real promise for addressing unmet medical needs, in particular refractory negative and cognitive symptoms, not currently addressed by existing antipsychotic agents.
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Affiliation(s)
- John A. Morrow
- Neuroscience and Ophthalmology, Merck Research Laboratories 2015 Galloping Hill Road, Kenilworth, New Jersey 07033 USA
| | - Robert Gilfillan
- Discovery Chemistry, Merck Research Laboratories 770 Sumneytown Pike, West Point, Pennsylvania 19486 USA
| | - Stuart A. Neale
- Neurexpert Ltd Ground Floor, 2 Woodberry Grove, North Finchley, London, N12 0DR UK
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37
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Gregory KJ, Noetzel MJ, Rook JM, Vinson PN, Stauffer SR, Rodriguez AL, Emmitte KA, Zhou Y, Chun AC, Felts AS, Chauder BA, Lindsley CW, Niswender CM, Conn PJ. Investigating metabotropic glutamate receptor 5 allosteric modulator cooperativity, affinity, and agonism: enriching structure-function studies and structure-activity relationships. Mol Pharmacol 2012; 82:860-75. [PMID: 22863693 DOI: 10.1124/mol.112.080531] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Drug discovery programs increasingly are focusing on allosteric modulators as a means to modify the activity of G protein-coupled receptor (GPCR) targets. Allosteric binding sites are topographically distinct from the endogenous ligand (orthosteric) binding site, which allows for co-occupation of a single receptor with the endogenous ligand and an allosteric modulator that can alter receptor pharmacological characteristics. Negative allosteric modulators (NAMs) inhibit and positive allosteric modulators (PAMs) enhance the affinity and/or efficacy of orthosteric agonists. Established approaches for estimation of affinity and efficacy values for orthosteric ligands are not appropriate for allosteric modulators, and this presents challenges for fully understanding the actions of novel modulators of GPCRs. Metabotropic glutamate receptor 5 (mGlu(5)) is a family C GPCR for which a large array of allosteric modulators have been identified. We took advantage of the many tools for probing allosteric sites on mGlu(5) to validate an operational model of allosterism that allows quantitative estimation of modulator affinity and cooperativity values. Affinity estimates derived from functional assays fit well with affinities measured in radioligand binding experiments for both PAMs and NAMs with diverse chemical scaffolds and varying degrees of cooperativity. We observed modulation bias for PAMs when we compared mGlu(5)-mediated Ca(2+) mobilization and extracellular signal-regulated kinase 1/2 phosphorylation data. Furthermore, we used this model to quantify the effects of mutations that reduce binding or potentiation by PAMs. This model can be applied to PAM and NAM potency curves in combination with maximal fold-shift data to derive reliable estimates of modulator affinities.
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Affiliation(s)
- Karen J Gregory
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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Bradley SJ, Challiss RJ. G protein-coupled receptor signalling in astrocytes in health and disease: A focus on metabotropic glutamate receptors. Biochem Pharmacol 2012; 84:249-59. [DOI: 10.1016/j.bcp.2012.04.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/02/2012] [Accepted: 04/09/2012] [Indexed: 02/03/2023]
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A model for Ca2+ oscillations stimulated by the type 5 metabotropic glutamate receptor: An unusual mechanism based on repetitive, reversible phosphorylation of the receptor. Biochimie 2011; 93:2132-8. [DOI: 10.1016/j.biochi.2011.09.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 09/11/2011] [Indexed: 11/17/2022]
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