1
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Strauss A, Gonzalez-Hernandez AJ, Lee J, Abreu N, Selvakumar P, Salas-Estrada L, Kristt M, Arefin A, Huynh K, Marx DC, Gilliland K, Melancon BJ, Filizola M, Meyerson J, Levitz J. Structural basis of positive allosteric modulation of metabotropic glutamate receptor activation and internalization. Nat Commun 2024; 15:6498. [PMID: 39090128 PMCID: PMC11294631 DOI: 10.1038/s41467-024-50548-x] [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: 03/21/2024] [Accepted: 07/12/2024] [Indexed: 08/04/2024] Open
Abstract
The metabotropic glutamate receptors (mGluRs) are neuromodulatory family C G protein coupled receptors which assemble as dimers and allosterically couple extracellular ligand binding domains (LBDs) to transmembrane domains (TMDs) to drive intracellular signaling. Pharmacologically, mGluRs can be targeted at the LBDs by glutamate and synthetic orthosteric compounds or at the TMDs by allosteric modulators. Despite the potential of allosteric compounds as therapeutics, an understanding of the functional and structural basis of their effects is limited. Here we use multiple approaches to dissect the functional and structural effects of orthosteric versus allosteric ligands. We find, using electrophysiological and live cell imaging assays, that both agonists and positive allosteric modulators (PAMs) can drive activation and internalization of group II and III mGluRs. The effects of PAMs are pleiotropic, boosting the maximal response to orthosteric agonists and serving independently as internalization-biased agonists across mGluR subtypes. Motivated by this and intersubunit FRET analyses, we determine cryo-electron microscopy structures of mGluR3 in the presence of either an agonist or antagonist alone or in combination with a PAM. These structures reveal PAM-driven re-shaping of intra- and inter-subunit conformations and provide evidence for a rolling TMD dimer interface activation pathway that controls G protein and beta-arrestin coupling.
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Affiliation(s)
- Alexa Strauss
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
- Tri-Institutional Program in Chemical Biology, New York, NY, 10065, USA
| | | | - Joon Lee
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Nohely Abreu
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Purushotham Selvakumar
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Leslie Salas-Estrada
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Melanie Kristt
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Anisul Arefin
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Kevin Huynh
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Dagan C Marx
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Kristen Gilliland
- Warren Center for Neuroscience Drug Discovery at Vanderbilt University, Vanderbilt University, Nashville, TN, 37232, USA
| | - Bruce J Melancon
- Warren Center for Neuroscience Drug Discovery at Vanderbilt University, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Marta Filizola
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joel Meyerson
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA.
- Tri-Institutional Program in Chemical Biology, New York, NY, 10065, USA.
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
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2
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Qi A, Kling HE, Billard N, Rodriguez AL, Peng L, Dickerson JW, Engers JL, Bender AM, Moehle MS, Lindsley CW, Rook JM, Niswender CM. Development of a Selective and High Affinity Radioligand, [ 3H]VU6013720, for the M 4 Muscarinic Receptor. Mol Pharmacol 2023; 104:195-202. [PMID: 37595966 PMCID: PMC10586508 DOI: 10.1124/molpharm.122.000643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 08/20/2023] Open
Abstract
M4 muscarinic receptors are highly expressed in the striatum and cortex, brain regions that are involved in diseases such as Parkinson's disease, schizophrenia, and dystonia. Despite potential therapeutic advantages of specifically targeting the M4 receptor, it has been historically challenging to develop highly selective ligands, resulting in undesired off-target activity at other members of the muscarinic receptor family. Recently, we have reported first-in-class, potent, and selective M4 receptor antagonists. As an extension of that work, we now report the development and characterization of a radiolabeled M4 receptor antagonist, [3H]VU6013720, with high affinity (pKd of 9.5 ± 0.2 at rat M4, 9.7 at mouse M4, and 10 ± 0.1 at human M4 with atropine to define nonspecific binding) and no significant binding at the other muscarinic subtypes. Binding assays using this radioligand in rodent brain tissues demonstrate loss of specific binding in Chrm4 knockout animals. Dissociation kinetics experiments with various muscarinic ligands show differential effects on the dissociation of [3H]VU6013720 from M4 receptors, suggesting a binding site that is overlapping but may be distinct from the orthosteric site. Overall, these results demonstrate that [3H]VU6013720 is the first highly selective antagonist radioligand for the M4 receptor, representing a useful tool for studying the basic biology of M4 as well for the support of M4 receptor-based drug discovery. SIGNIFICANCE STATEMENT: This manuscript describes the development and characterization of a novel muscarinic (M) acetylcholine subtype 4 receptor antagonist radioligand, [3H]VU6013720. This ligand binds to or overlaps with the acetylcholine binding site, providing a highly selective radioligand for the M4 receptor that can be used to quantify M4 protein expression in vivo and probe the selective interactions of acetylcholine with M4 versus the other members of the muscarinic receptor family.
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Affiliation(s)
- Aidong Qi
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Haley E Kling
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Natasha Billard
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Alice L Rodriguez
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Li Peng
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Jonathan W Dickerson
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Julie L Engers
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Aaron M Bender
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Mark S Moehle
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Craig W Lindsley
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Jerri M Rook
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Colleen M Niswender
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
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3
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Kang MS, Hamadjida A, Bédard D, Nuara SG, Gourdon JC, Frey S, Aliaga A, Ross K, Hopewell R, Bdair H, Mathieu A, Tardif CL, Soucy JP, Massarweh G, Rosa-Neto P, Huot P. Distribution of [ 11C]-JNJ-42491293 in the marmoset brain: a positron emission tomography study. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:2095-2103. [PMID: 36928556 DOI: 10.1007/s00210-023-02458-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023]
Abstract
JNJ-42491293 is a metabotropic glutamate 2 (mGlu2) positive allosteric modulator (PAM) that was radiolabelled with [11C]- to serve as a positron emission tomography (PET) ligand. Indeed, in vitro, the molecule displays high selectivity at mGlu2 receptors. However, PET experiments performed in rats, macaques and humans, have suggested that [11C]-JNJ-42491293 could interact with an unidentified, non-mGlu2 receptor binding site. The brain distribution of [11C]-JNJ-42491293 has not been determined in the brain of the common marmoset, a small non-human primate increasingly used in neuroscience research. Here, we investigated the distribution of [11C]-JNJ-42491293 in the marmoset brain. Three marmosets underwent brain magnetic resonance imaging (MRI) and 90-min dynamic PET scans with [11C]-JNJ-42491293 in combination with vehicle or the mGlu2 PAM AZD8529 (0.1, 1 and 10 mg/kg). In the scans in which [11C]-JNJ-42491293 was co-administered with vehicle, the brain areas with the highest standardised uptake values (SUVs) were the midbrain, cerebellum and thalamus, while the lowest SUVs were found in the pons. The addition of AZD8529 (0.1, 1 and 10 mg/kg) to [11C]-JNJ-42491293 did not modify the SUVs obtained with [11C]-JNJ-42491293 alone, and ex vivo blocking autoradiography with PAM AZD8529 (10, 100, 300 µM) on marmoset brain sections showed increased signals in the blocking conditions compared to vehicle, suggesting that no competition occurred between the 2 ligands. The results we obtained here do not suggest that [11C]-JNJ-42491293 interacts selectively, or even at all, with mGlu2 receptors in the marmoset, in agreement with findings previously reported in macaque and human.
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Affiliation(s)
- Min Su Kang
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, Montreal, QC, Canada
- Douglas Research Centre, McGill University, Montreal, QC, Canada
- Artificial Intelligence and Computational Neurosciences Lab, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
- LC Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Adjia Hamadjida
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
| | - Dominique Bédard
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
| | - Stephen G Nuara
- Comparative Medicine & Animal Resource Centre, McGill University, Montreal, QC, Canada
| | - Jim C Gourdon
- Comparative Medicine & Animal Resource Centre, McGill University, Montreal, QC, Canada
| | | | - Arturo Aliaga
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, Montreal, QC, Canada
- Douglas Research Centre, McGill University, Montreal, QC, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
| | - Karen Ross
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
| | - Robert Hopewell
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
| | - Hussein Bdair
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
| | - Axel Mathieu
- Douglas Research Centre, McGill University, Montreal, QC, Canada
| | - Christine Lucas Tardif
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
| | - Jean-Paul Soucy
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
| | - Gassan Massarweh
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, Montreal, QC, Canada
- Douglas Research Centre, McGill University, Montreal, QC, Canada
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute-Hospital (The Neuro), Montreal, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Philippe Huot
- Neurodegenerative Disease Group, Montreal Neurological Institute-Hospital (The Neuro), 3801 University St, Montreal, QC, H3A 2B4, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.
- Movement Disorder Clinic, Division of Neurology, Department of Neurosciences, McGill University Health Centre, Montreal, QC, Canada.
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4
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Strauss A, Gonzalez-Hernandez AJ, Lee J, Abreu N, Selvakumar P, Salas-Estrada L, Kristt M, Marx DC, Gilliland K, Melancon BJ, Filizola M, Meyerson J, Levitz J. Structural basis of allosteric modulation of metabotropic glutamate receptor activation and desensitization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.13.552748. [PMID: 37645747 PMCID: PMC10461995 DOI: 10.1101/2023.08.13.552748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The metabotropic glutamate receptors (mGluRs) are neuromodulatory family C G protein coupled receptors which assemble as dimers and allosterically couple extracellular ligand binding domains (LBDs) to transmembrane domains (TMDs) to drive intracellular signaling. Pharmacologically, mGluRs can be targeted either at the LBDs by glutamate and synthetic orthosteric compounds or at the TMDs by allosteric modulators. Despite the potential of allosteric TMD-targeting compounds as therapeutics, an understanding of the functional and structural basis of their effects on mGluRs is limited. Here we use a battery of approaches to dissect the distinct functional and structural effects of orthosteric versus allosteric ligands. We find using electrophysiological and live cell imaging assays that both agonists and positive allosteric modulators (PAMs) can drive activation and desensitization of mGluRs. The effects of PAMs are pleiotropic, including both the ability to boost the maximal response to orthosteric agonists and to serve independently as desensitization-biased agonists across mGluR subtypes. Conformational sensors reveal PAM-driven inter-subunit re-arrangements at both the LBD and TMD. Motivated by this, we determine cryo-electron microscopy structures of mGluR3 in the presence of either an agonist or antagonist alone or in combination with a PAM. These structures reveal PAM-driven re-shaping of intra- and inter-subunit conformations and provide evidence for a rolling TMD dimer interface activation pathway that controls G protein and beta-arrestin coupling. Highlights -Agonists and PAMs drive mGluR activation, desensitization, and endocytosis-PAMs are desensitization-biased and synergistic with agonists-Four combinatorial ligand conditions reveal an ensemble of full-length mGluR structures with novel interfaces-Activation and desensitization involve rolling TMD interfaces which are re-shaped by PAM.
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5
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Yuan G, Dhaynaut M, Guehl NJ, Neelamegam R, Moon SH, Qu X, Poutiainen P, Afshar S, Fakhri GE, Normandin MD, Brownell AL. PET imaging studies to investigate functional expression of mGluR2 using [ 11C]mG2P001. J Cereb Blood Flow Metab 2023; 43:296-308. [PMID: 36172629 PMCID: PMC9903221 DOI: 10.1177/0271678x221130387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 08/11/2022] [Accepted: 08/15/2022] [Indexed: 01/24/2023]
Abstract
Metabotropic glutamate receptor 2 (mGluR2) has been extensively studied for the treatment of various neurological and psychiatric disorders. Understanding of the mGluR2 function is pivotal in supporting the drug discovery targeting mGluR2. Herein, the positive allosteric modulation of mGluR2 was investigated via the in vivo positron emission tomography (PET) imaging using 2-((4-(2-[11C]methoxy-4-(trifluoromethyl)phenyl)piperidin-1-yl)methyl)-1-methyl-1H-imidazo[4,5-b]pyridine ([11C]mG2P001). Distinct from the orthosteric compounds, pretreatment with the unlabeled mG2P001, a potent mGluR2 positive allosteric modulator (PAM), resulted in a significant increase instead of decrease of the [11C]mG2P001 accumulation in rat brain detected by PET imaging. Subsequent in vitro studies with [3H]mG2P001 revealed the cooperative binding mechanism of mG2P001 with glutamate and its pharmacological effect that contributed to the enhanced binding of [3H]mG2P001 in transfected CHO cells expressing mGluR2. The in vivo PET imaging and quantitative analysis of [11C]mG2P001 in non-human primates (NHPs) further validated the characteristics of [11C]mG2P001 as an imaging ligand for mGluR2. Self-blocking studies in primates enhanced accumulation of [11C]mG2P001. Altogether, these studies show that [11C]mG2P001 is a sensitive biomarker for mGluR2 expression and the binding is affected by the tissue glutamate concentration.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Ramesh Neelamegam
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Xiying Qu
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Pekka Poutiainen
- Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, 70210, Finland
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
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6
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Yuan G, Dhaynaut M, Guehl NJ, Afshar S, Huynh D, Moon SH, Iyengar SM, Jain MK, Pickett JE, Kang HJ, Ondrechen MJ, El Fakhri G, Normandin MD, Brownell AL. Design, Synthesis, and Characterization of [ 18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2. J Med Chem 2022; 65:9939-9954. [PMID: 35802702 PMCID: PMC9434700 DOI: 10.1021/acs.jmedchem.2c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An array of triazolopyridines based on JNJ-46356479 (6) were synthesized as potential positron emission tomography radiotracers for metabotropic glutamate receptor 2 (mGluR2). The selected candidates 8-10 featured enhanced positive allosteric modulator (PAM) activity (20-fold max.) and mGluR2 agonist activity (25-fold max.) compared to compound 6 in the cAMP GloSensor assays. Radiolabeling of compounds 8 and 9 (mG2P026) was achieved via Cu-mediated radiofluorination with satisfactory radiochemical yield, >5% (non-decay-corrected); high molar activity, >180 GBq/μmol; and excellent radiochemical purity, >98%. Preliminary characterization of [18F]8 and [18F]9 in rats confirmed their excellent brain permeability and binding kinetics. Further evaluation of [18F]9 in a non-human primate confirmed its superior brain heterogeneity in mapping mGluR2 and higher affinity than [18F]6. Pretreatment with different classes of PAMs in rats and a primate led to similarly enhanced brain uptake of [18F]9. As a selective ligand, [18F]9 has the potential to be developed for translational studies.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Dalena Huynh
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Suhasini M Iyengar
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Manish Kumar Jain
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Julie E Pickett
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Mary Jo Ondrechen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
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7
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Yuan G, Dhaynaut M, Lan Y, Guehl NJ, Huynh D, Iyengar SM, Afshar S, Jain MK, Pickett JE, Kang HJ, Wang H, Moon SH, Ondrechen MJ, Wang C, Shoup TM, El Fakhri G, Normandin MD, Brownell AL. Synthesis and Characterization of 5-(2-Fluoro-4-[ 11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2 H-pyrano[2,3- b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2. J Med Chem 2022; 65:2593-2609. [PMID: 35089713 PMCID: PMC9434702 DOI: 10.1021/acs.jmedchem.1c02004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metabotropic glutamate receptor 2 (mGluR2) is a therapeutic target for several neuropsychiatric disorders. An mGluR2 function in etiology could be unveiled by positron emission tomography (PET). In this regard, 5-(2-fluoro-4-[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridine-7-carboxamide ([11C]13, [11C]mG2N001), a potent negative allosteric modulator (NAM), was developed to support this endeavor. [11C]13 was synthesized via the O-[11C]methylation of phenol 24 with a high molar activity of 212 ± 76 GBq/μmol (n = 5) and excellent radiochemical purity (>99%). PET imaging of [11C]13 in rats demonstrated its superior brain heterogeneity and reduced accumulation with pretreatment of mGluR2 NAMs, VU6001966 (9) and MNI-137 (26), the extent of which revealed a time-dependent drug effect of the blocking agents. In a nonhuman primate, [11C]13 selectively accumulated in mGluR2-rich regions and resulted in high-contrast brain images. Therefore, [11C]13 is a potential candidate for translational PET imaging of the mGluR2 function.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Yu Lan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Dalena Huynh
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Suhasini M Iyengar
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Manish Kumar Jain
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Julie E Pickett
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hao Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Mary Jo Ondrechen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Changning Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Timothy M Shoup
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
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8
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Allosteric modulators enhance agonist efficacy by increasing the residence time of a GPCR in the active state. Nat Commun 2021; 12:5426. [PMID: 34521824 PMCID: PMC8440590 DOI: 10.1038/s41467-021-25620-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 08/20/2021] [Indexed: 01/17/2023] Open
Abstract
Much hope in drug development comes from the discovery of positive allosteric modulators (PAM) that display target subtype selectivity and act by increasing agonist potency and efficacy. How such compounds can allosterically influence agonist action remains unclear. Metabotropic glutamate receptors (mGlu) are G protein-coupled receptors that represent promising targets for brain diseases, and for which PAMs acting in the transmembrane domain have been developed. Here, we explore the effect of a PAM on the structural dynamics of mGlu2 in optimized detergent micelles using single molecule FRET at submillisecond timescales. We show that glutamate only partially stabilizes the extracellular domains in the active state. Full activation is only observed in the presence of a PAM or the Gi protein. Our results provide important insights on the role of allosteric modulators in mGlu activation, by stabilizing the active state of a receptor that is otherwise rapidly oscillating between active and inactive states. Here, the authors use smFRET to assess the structural dynamics of metabotropic glutamate receptor mGlu2 and show that a positive allosteric modulator or the Gi protein stabilize mGlu2 in the glutamate-induced active state, leading to the full activation of the receptor.
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9
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10
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Donthamsetti P, Konrad DB, Hetzler B, Fu Z, Trauner D, Isacoff EY. Selective Photoswitchable Allosteric Agonist of a G Protein-Coupled Receptor. J Am Chem Soc 2021; 143:8951-8956. [PMID: 34115935 PMCID: PMC8227462 DOI: 10.1021/jacs.1c02586] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Indexed: 01/03/2023]
Abstract
G protein-coupled receptors (GPCRs) are the most common targets of drug discovery. However, the similarity between related GPCRs combined with the complex spatiotemporal dynamics of receptor activation in vivo has hindered drug development. Photopharmacology offers the possibility of using light to control the location and timing of drug action by incorporating a photoisomerizable azobenzene into a GPCR ligand, enabling rapid and reversible switching between an inactive and active configuration. Recent advances in this area include (i) photoagonists and photoantagonists that directly control receptor activity but are nonselective because they bind conserved sites, and (ii) photoallosteric modulators that bind selectively to nonconserved sites but indirectly control receptor activity by modulating the response to endogenous ligand. In this study, we designed a photoswitchable allosteric agonist that targets a nonconserved allosteric site for selectivity and activates the receptor on its own to provide direct control. This work culminated in the development of aBINA, a photoswitchable allosteric agonist that selectively activates the Gi/o-coupled metabotropic glutamate receptor 2 (mGluR2). aBINA is the first example of a new class of precision drugs for GPCRs and other clinically important signaling proteins.
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Affiliation(s)
- Prashant Donthamsetti
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
| | - David B. Konrad
- Department
of Pharmacy, Ludwig-Maximilians-Universität
München, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Belinda Hetzler
- Department
of Chemistry, New York University, New York, New York 10003, United States
| | - Zhu Fu
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
| | - Dirk Trauner
- Department
of Chemistry, New York University, New York, New York 10003, United States
| | - Ehud Y. Isacoff
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- Helen
Wills Neuroscience Institute, University
of California, Berkeley, California 94720, United States
- Molecular
Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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11
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Thibado JK, Tano JY, Lee J, Salas-Estrada L, Provasi D, Strauss A, Marcelo Lamim Ribeiro J, Xiang G, Broichhagen J, Filizola M, Lohse MJ, Levitz J. Differences in interactions between transmembrane domains tune the activation of metabotropic glutamate receptors. eLife 2021; 10:e67027. [PMID: 33880992 PMCID: PMC8102066 DOI: 10.7554/elife.67027] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/19/2021] [Indexed: 12/16/2022] Open
Abstract
The metabotropic glutamate receptors (mGluRs) form a family of neuromodulatory G-protein-coupled receptors that contain both a seven-helix transmembrane domain (TMD) and a large extracellular ligand-binding domain (LBD) which enables stable dimerization. Although numerous studies have revealed variability across subtypes in the initial activation steps at the level of LBD dimers, an understanding of inter-TMD interaction and rearrangement remains limited. Here, we use a combination of single molecule fluorescence, molecular dynamics, functional assays, and conformational sensors to reveal that distinct TMD assembly properties drive differences between mGluR subtypes. We uncover a variable region within transmembrane helix 4 (TM4) that contributes to homo- and heterodimerization in a subtype-specific manner and tunes orthosteric, allosteric, and basal activation. We also confirm a critical role for a conserved inter-TM6 interface in stabilizing the active state during orthosteric or allosteric activation. Together this study shows that inter-TMD assembly and dynamic rearrangement drive mGluR function with distinct properties between subtypes.
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Affiliation(s)
- Jordana K Thibado
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical SciencesNew YorkUnited States
| | | | - Joon Lee
- Department of Biochemistry, Weill Cornell MedicineNew YorkUnited States
| | - Leslie Salas-Estrada
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Davide Provasi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Alexa Strauss
- Tri-Institutional PhD Program in Chemical BiologyNew YorkUnited States
| | | | - Guoqing Xiang
- Department of Biochemistry, Weill Cornell MedicineNew YorkUnited States
| | | | - Marta Filizola
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Martin J Lohse
- Max Delbrück Center for Molecular MedicineBerlinGermany
- ISAR Bioscience InstitutePlanegg-MunichGermany
| | - Joshua Levitz
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical SciencesNew YorkUnited States
- Department of Biochemistry, Weill Cornell MedicineNew YorkUnited States
- Tri-Institutional PhD Program in Chemical BiologyNew YorkUnited States
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12
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Xiang Z, Lv X, Lin X, O'Brien DE, Altman MK, Lindsley CW, Javitch JA, Niswender CM, Conn PJ. Input-specific regulation of glutamatergic synaptic transmission in the medial prefrontal cortex by mGlu 2/mGlu 4 receptor heterodimers. Sci Signal 2021; 14:14/677/eabd2319. [PMID: 33824180 DOI: 10.1126/scisignal.abd2319] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that regulate various aspects of central nervous system processing in normal physiology and in disease. They are thought to function as disulfide-linked homodimers, but studies have suggested that mGluRs can form functional heterodimers in cell lines. Using selective allosteric ligands, ex vivo brain slice electrophysiology, and optogenetic approaches, we found that two mGluR subtypes-mGluR2 and mGluR4 (or mGlu2 and mGlu4)-exist as functional heterodimers that regulate excitatory transmission in a synapse-specific manner within the rodent medial prefrontal cortex (mPFC). Activation of mGlu2/mGlu4 heterodimers inhibited glutamatergic signaling at thalamo-mPFC synapses but not at hippocampus-mPFC or amygdala-mPFC synapses. These findings raise the possibility that selectively targeting these heterodimers could be a therapeutic strategy for some neurologic and neuropsychiatric disorders involving specific brain circuits.
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Affiliation(s)
- Zixiu Xiang
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Xiaohui Lv
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Xin Lin
- Department of Psychiatry, Columbia University, New York, NY 10032, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Daniel E O'Brien
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Molly K Altman
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - Jonathan A Javitch
- Department of Psychiatry, Columbia University, New York, NY 10032, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA.,Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY 10032, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA. .,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University, Nashville, TN 37232, USA
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13
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Yuan G, Guehl NJ, Zheng B, Qu X, Moon SH, Dhaynaut M, Shoup TM, Afshar S, Kang HJ, Zhang Z, El Fakhri G, Normandin MD, Brownell AL. Synthesis and Characterization of [ 18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Mol Imaging Biol 2021; 23:527-536. [PMID: 33559035 DOI: 10.1007/s11307-021-01586-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/11/2021] [Accepted: 01/27/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE Metabotropic glutamate receptor 2 (mGluR2) has been implicated in various psychiatric and neurological disorders, such as schizophrenia and Alzheimer's disease. We have previously developed [11C]7 as a PET radioligand for imaging mGluR2. Herein, [18F]JNJ-46356479 ([18F]8) was synthesized and characterized as the first 18F-labeled mGluR2 imaging ligand to enhance diagnostic approaches for mGluR2-related disorders. PROCEDURES JNJ-46356479 (8) was radiolabeled via the copper (I)-mediated radiofluorination of organoborane 9. In vivo PET imaging experiments with [18F]8 were conducted first in C57BL/6 J mice and Sprague-Dawley rats to obtain whole body biodistribution and brain uptake profile. Subsequent PET studies were done in a cynomolgus monkey (Macaca fascicularis) to investigate the uptake of [18F]8 in the brain, its metabolic stability, as well as pharmacokinetic properties. RESULTS JNJ-46356479 (8) exhibited excellent selectivity against other mGluRs. In vivo PET imaging studies showed reversible and specific binding characteristic of [18F]8 in rodents. In the non-human primate, [18F]8 displayed good in vivo metabolic stability, excellent brain permeability, fast and reversible kinetics with moderate heterogeneity across brain regions. Pre-treatment studies with compound 7 revealed time-dependent decrease of [18F]8 accumulation in mGluR2 rich regions based on SUV values with the highest decrease in the nucleus accumbens (18.7 ± 5.9%) followed by the cerebellum (18.0 ± 7.9%), the parietal cortex (16.9 ± 7.8%), and the hippocampus (16.8 ± 6.9%), similar to results obtained in the rat studies. However, the volume of distribution (VT) results derived from 2T4k model showed enhanced VT from a blocking study with compound 7. This is probably because of the potentiating effect of compound 7 as an mGluR2 PAM as well as related non-specific binding in the tissue data. CONCLUSIONS [18F]8 readily crosses the blood-brain barrier and demonstrates fast and reversible kinetics both in rodents and in a non-human primate. Further investigation of [18F]8 on its binding specificity would warrant translational study in human.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA.
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Baohui Zheng
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Xiying Qu
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Timothy M Shoup
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, 27514, USA
| | - Zhaoda Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, MA, 02129, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA.
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14
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Elhussiny MEA, Carini G, Mingardi J, Tornese P, Sala N, Bono F, Fiorentini C, La Via L, Popoli M, Musazzi L, Barbon A. Modulation by chronic stress and ketamine of ionotropic AMPA/NMDA and metabotropic glutamate receptors in the rat hippocampus. Prog Neuropsychopharmacol Biol Psychiatry 2021; 104:110033. [PMID: 32640261 DOI: 10.1016/j.pnpbp.2020.110033] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/22/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022]
Abstract
Converging clinical and preclinical evidence has shown that dysfunction of the glutamate system is a core feature of major depressive disorder. In this context, the N-methyl-d-aspartate (NMDA) receptor antagonist ketamine has raised growing interest as fast acting antidepressant. Using the chronic mild stress (CMS) rat model of depression, performed in male rats, we aimed at analyzing whether hippocampal specific changes in subunit expression and regulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) or NMDA ionotropic receptors and in metabotropic glutamate receptors could be associated with behavioral vulnerability/resilience to CMS. We also assessed whether acute ketamine (10 mg/kg) was able to dampen the alterations in CMS vulnerable animals. Although chronic stress and ketamine had no effect on ionotropic glutamate receptors mRNAs (expression, RNA editing and splicing), we found selective modulations in their protein expression, phosphorylation and localization at synaptic membranes. AMPA GluA2 expression at synaptic membranes was significantly increased only in CMS resilient rats (although a trend was found also in vulnerable animals), while its phosphorylation at Ser880 was higher in both CMS resilient and vulnerable rats, a change partially dampened by ketamine. In the hippocampus from all stressed groups, despite NMDA receptor expression levels were reduced in total extract, the levels of GluN2B-containing NMDA receptors were remarkably increased in synaptic membranes. Finally, mGlu2 underwent a selective downregulation in stress vulnerable animals, which was completely restored by acute ketamine. Overall, these results are in line with a hypofunction of activity-dependent glutamatergic synaptic transmission induced by chronic stress exposure in all the animals, as suggested by the alterations of ionotropic glutamate receptors expression and localization at synaptic level. At the same time, the selective modulation of mGlu2 receptor, confirms its previously hypothesized functional role in regulating stress vulnerability and, for the first time here, suggests a mGlu2 involvement in the fast antidepressant effect of ketamine.
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Affiliation(s)
- Mohammed E A Elhussiny
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Giulia Carini
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Jessica Mingardi
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Paolo Tornese
- Laboratory of Neuropsychopharmacology and Functional Neurogenomics, Dipartimento di Scienze Farmaceutiche, Sezione di Fisiologia e Farmacologia, Università degli Studi di Milano, Milan, Italy
| | - Nathalie Sala
- Laboratory of Neuropsychopharmacology and Functional Neurogenomics, Dipartimento di Scienze Farmaceutiche, Sezione di Fisiologia e Farmacologia, Università degli Studi di Milano, Milan, Italy
| | - Federica Bono
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Chiara Fiorentini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Luca La Via
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Maurizio Popoli
- Laboratory of Neuropsychopharmacology and Functional Neurogenomics, Dipartimento di Scienze Farmaceutiche, Sezione di Fisiologia e Farmacologia, Università degli Studi di Milano, Milan, Italy
| | - Laura Musazzi
- Laboratory of Neuropsychopharmacology and Functional Neurogenomics, Dipartimento di Scienze Farmaceutiche, Sezione di Fisiologia e Farmacologia, Università degli Studi di Milano, Milan, Italy
| | - Alessandro Barbon
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
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15
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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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16
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Doller D, Bespalov A, Miller R, Pietraszek M, Kalinichev M. A case study of foliglurax, the first clinical mGluR4 PAM for symptomatic treatment of Parkinson's disease: translational gaps or a failing industry innovation model? Expert Opin Investig Drugs 2020; 29:1323-1338. [PMID: 33074728 DOI: 10.1080/13543784.2020.1839047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Approximately 40% of Parkinson's disease (PD) patients that take mostly dopamine receptor agonists for motor fluctuations, experience the return of symptoms between regular doses. This is a phenomenon known as 'OFF periods.' Positive allosteric modulators (PAMs) of metabotropic glutamate receptor 4 (mGluR4) are a promising non-dopaminergic mechanism with potential to address the unmet need of patients suffering from OFF periods. Foliglurax is the first mGluR4 PAM that has advanced into clinical testing in PD patients. AREAS COVERED We summarize the chemistry, pharmacokinetics, and preclinical pharmacology of foliglurax. Translational PET imaging studies, clinical efficacy data, and a competitive landscape analysis of available therapies are presented to the readers. In this Perspective article, foliglurax is used as a case study to illustrate the inherent R&D challenges that companies face when developing drugs. These challenges include the delivery of drugs acting through novel mechanisms, long-term scientific investment, and commercial success and shorter-term positive financial returns. EXPERT OPINION Failure to meet the primary and secondary endpoints in a Phase 2 study led Lundbeck to discontinue the development of foliglurax. Understanding the evidence supporting compound progression into Phase 2 will enable the proper assessment of the therapeutic potential of mGluR4 PAMs.
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Affiliation(s)
| | - Anton Bespalov
- Partnership for Assessment and Accreditation of Scientific Practice , Heidelberg, Germany.,Valdman Institute of Pharmacology, Pavlov Medical University , St. Petersburg, Russia
| | - Rob Miller
- Ventral Stream Consulting LLC ., IL, USA
| | - Malgorzata Pietraszek
- Partnership for Assessment and Accreditation of Scientific Practice , Heidelberg, Germany
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17
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The function and allosteric control of the human sweet taste receptor. FROM STRUCTURE TO CLINICAL DEVELOPMENT: ALLOSTERIC MODULATION OF G PROTEIN-COUPLED RECEPTORS 2020; 88:59-82. [DOI: 10.1016/bs.apha.2020.01.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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18
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Moran SP, Xiang Z, Doyle CA, Maksymetz J, Lv X, Faltin S, Fisher NM, Niswender CM, Rook JM, Lindsley CW, Conn PJ. Biased M 1 receptor-positive allosteric modulators reveal role of phospholipase D in M 1-dependent rodent cortical plasticity. Sci Signal 2019; 12:12/610/eaax2057. [PMID: 31796631 DOI: 10.1126/scisignal.aax2057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Highly selective, positive allosteric modulators (PAMs) of the M1 subtype of muscarinic acetylcholine receptor have emerged as an exciting new approach to potentially improve cognitive function in patients suffering from Alzheimer's disease and schizophrenia. Discovery programs have produced a structurally diverse range of M1 receptor PAMs with distinct pharmacological properties, including different extents of agonist activity and differences in signal bias. This includes biased M1 receptor PAMs that can potentiate coupling of the receptor to activation of phospholipase C (PLC) but not phospholipase D (PLD). However, little is known about the role of PLD in M1 receptor signaling in native systems, and it is not clear whether biased M1 PAMs display differences in modulating M1-mediated responses in native tissue. Using PLD inhibitors and PLD knockout mice, we showed that PLD was necessary for the induction of M1-dependent long-term depression (LTD) in the prefrontal cortex (PFC). Furthermore, biased M1 PAMs that did not couple to PLD not only failed to potentiate orthosteric agonist-induced LTD but also blocked M1-dependent LTD in the PFC. In contrast, biased and nonbiased M1 PAMs acted similarly in potentiating M1-dependent electrophysiological responses that were PLD independent. These findings demonstrate that PLD plays a critical role in the ability of M1 PAMs to modulate certain central nervous system (CNS) functions and that biased M1 PAMs function differently in brain regions implicated in cognition.
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Affiliation(s)
- Sean P Moran
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Zixiu Xiang
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Catherine A Doyle
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - James Maksymetz
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Xiaohui Lv
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Sehr Faltin
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Nicole M Fisher
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Jerri M Rook
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA. .,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37240, USA
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19
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Hao J, Chen Q. Insights into the Structural Aspects of the mGlu Receptor Orthosteric Binding Site. Curr Top Med Chem 2019; 19:2421-2446. [PMID: 31660833 DOI: 10.2174/1568026619666191011094935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/28/2019] [Accepted: 09/04/2019] [Indexed: 02/06/2023]
Abstract
The amino terminal domain (ATD) of the metabotropic glutamate (mGlu) receptors contains the orthosteric glutamate recognition site, which is highly conserved across the eight mGlu receptor subtypes. In total, 29 X-ray crystal structures of the mGlu ATD proteins have been reported to date. These structures span across 3 subgroups and 6 subtypes, and include apo, agonist- and antagonist-bound structures. We will discuss the insights gained from the analysis of these structures with the focus on the interactions contributing to the observed group and subtype selectivity for select agonists. Furthermore, we will define the full expanded orthosteric ligand binding pocket (LBP) of the mGlu receptors, and discuss the macroscopic features of the mGlu ATD proteins.
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Affiliation(s)
- Junliang Hao
- Discovery Chemistry Research and Technologies, Lilly Research Laboratory, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, United States
| | - Qi Chen
- Discovery Chemistry Research and Technologies, Lilly Research Laboratory, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, United States
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20
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Gutzeit VA, Thibado J, Stor DS, Zhou Z, Blanchard SC, Andersen OS, Levitz J. Conformational dynamics between transmembrane domains and allosteric modulation of a metabotropic glutamate receptor. eLife 2019; 8:45116. [PMID: 31172948 PMCID: PMC6588349 DOI: 10.7554/elife.45116] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/06/2019] [Indexed: 01/01/2023] Open
Abstract
Metabotropic glutamate receptors (mGluRs) are class C, synaptic G-protein-coupled receptors (GPCRs) that contain large extracellular ligand binding domains (LBDs) and form constitutive dimers. Despite the existence of a detailed picture of inter-LBD conformational dynamics and structural snapshots of both isolated domains and full-length receptors, it remains unclear how mGluR activation proceeds at the level of the transmembrane domains (TMDs) and how TMD-targeting allosteric drugs exert their effects. Here, we use time-resolved functional and conformational assays to dissect the mechanisms by which allosteric drugs activate and modulate mGluR2. Single-molecule subunit counting and inter-TMD fluorescence resonance energy transfer measurements in living cells reveal LBD-independent conformational rearrangements between TMD dimers during receptor modulation. Using these assays along with functional readouts, we uncover heterogeneity in the magnitude, direction, and the timing of the action of both positive and negative allosteric drugs. Together our experiments lead to a three-state model of TMD activation, which provides a framework for understanding how inter-subunit rearrangements drive class C GPCR activation.
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Affiliation(s)
- Vanessa A Gutzeit
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, United States
| | - Jordana Thibado
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, United States
| | - Daniel Starer Stor
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, United States
| | - Zhou Zhou
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States
| | - Scott C Blanchard
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, United States.,Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States.,Tri-Institutional PhD Program in Chemical Biology, New York, United States
| | - Olaf S Andersen
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, United States.,Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States
| | - Joshua Levitz
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, United States.,Tri-Institutional PhD Program in Chemical Biology, New York, United States.,Department of Biochemistry, Weill Cornell Medicine, New York, United States
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Abstract
Abnormalities of glutamatergic transmission are implicated in neuropsychiatric disorders. Among the glutamate receptors, metabotropic (mGlu) 2/3 receptors have recently gained much attention as molecular targets for the treatment of several neuropsychiatric disorders including depression and anxiety. Both orthosteric and allosteric antagonists of mGlu2/3 receptors have been synthesized, and their therapeutic potential has been examined. These research activities have demonstrated the promise of mGlu2/3 receptor antagonists as potential treatment agents for the above-mentioned neuropsychiatric disorders. In particular, it has been considered that the antidepressant effects of mGlu2/3 receptor antagonists are worthy of pursuing, since the antidepressant profiles as well as synaptic/neural mechanisms involved in the actions of mGlu2/3 receptor antagonists are similar to those of ketamine, which has been demonstrated to show potent, rapid and sustained efficacy in patients with depression, even those resistant to the conventionally prescribed antidepressants. In this chapter, the general pharmacology of mGlu2/3 receptor antagonists and their therapeutic potential are reviewed. In particular, I focus on the usefulness of mGlu2/3 receptor antagonists as novel antidepressants, in comparison with ketamine.
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