51
|
Pittaluga A. Presynaptic Release-Regulating mGlu1 Receptors in Central Nervous System. Front Pharmacol 2016; 7:295. [PMID: 27630571 PMCID: PMC5006178 DOI: 10.3389/fphar.2016.00295] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/22/2016] [Indexed: 01/14/2023] Open
Abstract
Group I metabotropic glutamate (mGlu) receptors consists of mGlu1 and mGlu5 receptor subtypes. These receptors are widely distributed in the central nervous system (CNS), where they preferentially mediate facilitatory signaling in neurones and glial cells, mainly by favoring phospholipase (PLC) translocation. Based on the literature so far available, group I Metabotropic glutamate receptors (mGluRs) are preferentially expressed at the postsynaptic side of chemical synapsis, where they participate in the progression of the chemical stimulus. Studies, however, have shown the presence of these receptors also at the presynaptic level, where they exert several functions, including the modulation of transmitter exocytosis. Presynaptic Group I mGluRs can be both autoreceptors regulating release of glutamate and heteroreceptors regulating the release of various transmitters, including GABA, dopamine, noradrenaline, and acetylcholine. While the existence of presynaptic release-regulating mGlu5 receptors is largely recognized, the possibility that mGlu1 receptors also are present at this level has been a matter of discussion for a long time. A large body of evidence published in the last decade, however, supports this notion. This review aims at revisiting the data from in vitro studies concerning the existence and the role of release-regulating mGlu1 receptors presynaptically located in nerve terminals isolated from selected regions of the CNS. The functional interaction linking mGlu5 and mGlu1 receptor subtypes at nerve terminals and their relative contributions as modulators of central transmission will also be discussed. We apologize in advance for omission in our coverage of the existing literature.
Collapse
Affiliation(s)
- Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of GenoaGenoa, Italy
- Center of Excellence for Biomedical Research, University of GenoaGenoa, Italy
| |
Collapse
|
52
|
Nemoto W, Yamanishi Y, Limviphuvadh V, Saito A, Toh H. GGIP: Structure and sequence-based GPCR-GPCR interaction pair predictor. Proteins 2016; 84:1224-33. [PMID: 27191053 DOI: 10.1002/prot.25071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 04/26/2016] [Accepted: 05/09/2016] [Indexed: 01/20/2023]
Abstract
G Protein-Coupled Receptors (GPCRs) are important pharmaceutical targets. More than 30% of currently marketed pharmaceutical medicines target GPCRs. Numerous studies have reported that GPCRs function not only as monomers but also as homo- or hetero-dimers or higher-order molecular complexes. Many GPCRs exert a wide variety of molecular functions by forming specific combinations of GPCR subtypes. In addition, some GPCRs are reportedly associated with diseases. GPCR oligomerization is now recognized as an important event in various biological phenomena, and many researchers are investigating this subject. We have developed a support vector machine (SVM)-based method to predict interacting pairs for GPCR oligomerization, by integrating the structure and sequence information of GPCRs. The performance of our method was evaluated by the Receiver Operating Characteristic (ROC) curve. The corresponding area under the curve was 0.938. As far as we know, this is the only prediction method for interacting pairs among GPCRs. Our method could accelerate the analyses of these interactions, and contribute to the elucidation of the global structures of the GPCR networks in membranes. Proteins 2016; 84:1224-1233. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Wataru Nemoto
- Division of Life Science and Engineering, School of Science and Engineering, Tokyo Denki University (TDU), Ishizaka, Hatoyama-Machi, Hiki-Gun, Saitama, 350-0394, Japan.,Computational Biology Research Center (CBRC), Advanced Industrial Science and Technology (AIST), AIST Tokyo Waterfront Bio-IT Research Building, 2-4-7 Aomi, Koto-Ku, Tokyo, 135-0064, Japan
| | - Yoshihiro Yamanishi
- Medical Institute of Bioregulation (MiB), Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka, 812-8582, Japan.,Institute for Advanced Study, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan
| | - Vachiranee Limviphuvadh
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01 Matrix, 138671, Singapore
| | - Akira Saito
- Division of Life Science and Engineering, School of Science and Engineering, Tokyo Denki University (TDU), Ishizaka, Hatoyama-Machi, Hiki-Gun, Saitama, 350-0394, Japan
| | - Hiroyuki Toh
- Computational Biology Research Center (CBRC), Advanced Industrial Science and Technology (AIST), AIST Tokyo Waterfront Bio-IT Research Building, 2-4-7 Aomi, Koto-Ku, Tokyo, 135-0064, Japan.,Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda-Shi, Hyogo, 669-1337, Japan
| |
Collapse
|
53
|
Abstract
Psychedelics (serotonergic hallucinogens) are powerful psychoactive substances that alter perception and mood and affect numerous cognitive processes. They are generally considered physiologically safe and do not lead to dependence or addiction. Their origin predates written history, and they were employed by early cultures in many sociocultural and ritual contexts. After the virtually contemporaneous discovery of (5R,8R)-(+)-lysergic acid-N,N-diethylamide (LSD)-25 and the identification of serotonin in the brain, early research focused intensively on the possibility that LSD and other psychedelics had a serotonergic basis for their action. Today there is a consensus that psychedelics are agonists or partial agonists at brain serotonin 5-hydroxytryptamine 2A receptors, with particular importance on those expressed on apical dendrites of neocortical pyramidal cells in layer V. Several useful rodent models have been developed over the years to help unravel the neurochemical correlates of serotonin 5-hydroxytryptamine 2A receptor activation in the brain, and a variety of imaging techniques have been employed to identify key brain areas that are directly affected by psychedelics. Recent and exciting developments in the field have occurred in clinical research, where several double-blind placebo-controlled phase 2 studies of psilocybin-assisted psychotherapy in patients with cancer-related psychosocial distress have demonstrated unprecedented positive relief of anxiety and depression. Two small pilot studies of psilocybin-assisted psychotherapy also have shown positive benefit in treating both alcohol and nicotine addiction. Recently, blood oxygen level-dependent functional magnetic resonance imaging and magnetoencephalography have been employed for in vivo brain imaging in humans after administration of a psychedelic, and results indicate that intravenously administered psilocybin and LSD produce decreases in oscillatory power in areas of the brain's default mode network.
Collapse
Affiliation(s)
- David E Nichols
- Eschelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina
| |
Collapse
|
54
|
Engidawork E, Aradska J, Lubec G. Neurotransmitter receptor complexes: methods for bioanalysis, their potentials and limitations. Rev Neurosci 2016; 27:111-33. [DOI: 10.1515/revneuro-2015-0034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 08/11/2015] [Indexed: 12/15/2022]
Abstract
AbstractNeurotransmitter receptors are key elements for brain function, but work so far has been focusing on the individual receptor subunits. It is, however, the receptor complexes that execute work rather than the subunits; of course, the multitude of possible combinations of the many receptors forming homomeric or heteromeric complexes is hampering studies. Moreover, not only receptors are observed in the complexes but also their corresponding protein kinases, phosphatases, and anchoring proteins, to name a few. Studying receptor complexes is still an analytical challenge. Thus far, no methods exist to unequivocally characterize or even quantify these assemblies. Major problems and limitations for the analysis exist, such as solubility, as the use of detergents is critical and may dissociate the receptor complexes as well as their separation in the native state. Gel-based techniques are able to separate and semiquantitatively quantify receptor complexes by subsequent immunochemical methods but do not allow the characterization of complex components. Immunoprecipitation methods are highly dependent on antibody availability and specificity, and the result of coimmunoprecipitation does not verify the direct physical interaction of proteins in the immunoprecipitate. Antibody shift assays are suitable to identify individual known proteins within a complex as are immunogold electron microscopic techniques and energy transfer technologies. Most techniques are simply showing the proximity of proteins rather than their physical interaction. Although fluorescence correlation spectroscopy is a promising technique, the use for quantification or comparing biological samples is limited. A lot of work remains to be done to provide tools for the characterization and quantification of receptor complexes in the brain.
Collapse
Affiliation(s)
| | - Jana Aradska
- 1Department of Pediatrics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Gert Lubec
- 3Department of Pharmaceutical Chemistry, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
| |
Collapse
|
55
|
Baki L, Fribourg M, Younkin J, Eltit JM, Moreno JL, Park G, Vysotskaya Z, Narahari A, Sealfon SC, Gonzalez-Maeso J, Logothetis DE. Cross-signaling in metabotropic glutamate 2 and serotonin 2A receptor heteromers in mammalian cells. Pflugers Arch 2016; 468:775-93. [PMID: 26780666 DOI: 10.1007/s00424-015-1780-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/21/2015] [Indexed: 11/30/2022]
Abstract
We previously reported that co-expression of the Gi-coupled metabotropic glutamate receptor 2 (mGlu2R) and the Gq-coupled serotonin (5-HT) 2A receptor (2AR) in Xenopus oocytes (Fribourg et al. Cell 147:1011-1023, 2011) results in inverse cross-signaling, where for either receptor, strong agonists suppress and inverse agonists potentiate the signaling of the partner receptor. Importantly, through this cross-signaling, the mGlu2R/2AR heteromer integrates the actions of psychedelic and antipsychotic drugs. To investigate whether mGlu2R and 2AR can cross-signal in mammalian cells, we stably co-expressed them in HEK293 cells along with the GIRK1/GIRK4 channel, a reporter of Gi and Gq signaling activity. Crosstalk-positive clones were identified by Fura-2 calcium imaging, based on potentiation of 5-HT-induced Ca(2+) responses by the inverse mGlu2/3R agonist LY341495. Cross-signaling from both sides of the complex was confirmed in representative clones by using the GIRK channel reporter, both in whole-cell patch-clamp and in fluorescence assays using potentiometric dyes, and further established by competition binding assays. Notably, only 25-30 % of the clones were crosstalk-positive. The crosstalk-positive phenotype correlated with (a) increased colocalization of the two receptors at the cell surface, (b) lower density of mGlu2R binding sites and higher density of 2AR binding sites in total membrane preparations, and (c) higher ratios of mGlu2R/2AR normalized surface protein expression. Consistent with our results in Xenopus oocytes, a combination of ligands targeting both receptors could elicit functional crosstalk in a crosstalk-negative clone. Crosstalk-positive clones can be used in high-throughput assays for identification of antipsychotic drugs targeting this receptor heterocomplex.
Collapse
Affiliation(s)
- Lia Baki
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Miguel Fribourg
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jason Younkin
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Jose Miguel Eltit
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Jose L Moreno
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Gyu Park
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Zhanna Vysotskaya
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Adishesh Narahari
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Stuart C Sealfon
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Javier Gonzalez-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Diomedes E Logothetis
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
| |
Collapse
|
56
|
Moreno JL, Miranda-Azpiazu P, García-Bea A, Younkin J, Cui M, Kozlenkov A, Ben-Ezra A, Voloudakis G, Fakira AK, Baki L, Ge Y, Georgakopoulos A, Morón JA, Milligan G, López-Giménez JF, Robakis NK, Logothetis DE, Meana JJ, González-Maeso J. Allosteric signaling through an mGlu2 and 5-HT2A heteromeric receptor complex and its potential contribution to schizophrenia. Sci Signal 2016; 9:ra5. [PMID: 26758213 DOI: 10.1126/scisignal.aab0467] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) can form multiprotein complexes (heteromers), which can alter the pharmacology and functions of the constituent receptors. Previous findings demonstrated that the Gq/11-coupled serotonin 5-HT2A receptor and the Gi/o-coupled metabotropic glutamate 2 (mGlu2) receptor-GPCRs that are involved in signaling alterations associated with psychosis-assemble into a heteromeric complex in the mammalian brain. In single-cell experiments with various mutant versions of the mGlu2 receptor, we showed that stimulation of cells expressing mGlu2-5-HT2A heteromers with an mGlu2 agonist led to activation of Gq/11 proteins by the 5-HT2A receptors. For this crosstalk to occur, one of the mGlu2 subunits had to couple to Gi/o proteins, and we determined the relative location of the Gi/o-contacting subunit within the mGlu2 homodimer of the heteromeric complex. Additionally, mGlu2-dependent activation of Gq/11, but not Gi/o, was reduced in the frontal cortex of 5-HT2A knockout mice and was reduced in the frontal cortex of postmortem brains from schizophrenic patients. These findings offer structural insights into this important target in molecular psychiatry.
Collapse
Affiliation(s)
- José L Moreno
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Patricia Miranda-Azpiazu
- Department of Pharmacology, University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Aintzane García-Bea
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Pharmacology, University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Jason Younkin
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Meng Cui
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Alexey Kozlenkov
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ariel Ben-Ezra
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Georgios Voloudakis
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Amanda K Fakira
- Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Lia Baki
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Yongchao Ge
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - José A Morón
- Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Graeme Milligan
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Juan F López-Giménez
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK. Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC-CSIC-UC), E-39011 Santander, Cantabria, Spain
| | - Nikolaos K Robakis
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Diomedes E Logothetis
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - J Javier Meana
- Department of Pharmacology, University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. BioCruces Health Research Institute, E-48903 Barakaldo, Bizkaia, Spain.
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| |
Collapse
|
57
|
Guiard BP, Di Giovanni G. Central serotonin-2A (5-HT2A) receptor dysfunction in depression and epilepsy: the missing link? Front Pharmacol 2015; 6:46. [PMID: 25852551 PMCID: PMC4362472 DOI: 10.3389/fphar.2015.00046] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 02/24/2015] [Indexed: 11/17/2022] Open
Abstract
5-Hydroxytryptamine 2A receptors (5-HT2A-Rs) are G-protein coupled receptors. In agreement with their location in the brain, they have been implicated not only in various central physiological functions including memory, sleep, nociception, eating and reward behaviors, but also in many neuropsychiatric disorders. Interestingly, a bidirectional link between depression and epilepsy is suspected since patients with depression and especially suicide attempters have an increased seizure risk, while a significant percentage of epileptic patients suffer from depression. Such epidemiological data led us to hypothesize that both pathologies may share common anatomical and neurobiological alteration of the 5-HT2A signaling. After a brief presentation of the pharmacological properties of the 5-HT2A-Rs, this review illustrates how these receptors may directly or indirectly control neuronal excitability in most networks involved in depression and epilepsy through interactions with the monoaminergic, GABAergic and glutamatergic neurotransmissions. It also synthetizes the preclinical and clinical evidence demonstrating the role of these receptors in antidepressant and antiepileptic responses.
Collapse
Affiliation(s)
- Bruno P Guiard
- CNRS, Centre de Recherches sur la Cognition Animale, UMR 5169, Toulouse France ; CNRS, Centre de Recherches sur la Cognition Animale Université de Toulouse 3, UMR 5169, Toulouse, France ; INSERM U1178 Team ≪Depression and Antidepressants≫ Faculté de Pharmacie Paris Sud, Châtenay-Malabry, France
| | - Giuseppe Di Giovanni
- Neurophysiology Unit, Laboratory for the Study of Neurological Disorders, Department of Physiology and Biochemistry, University of Malta, Msida Malta ; School of Biosciences, University of Cardiff, Cardiff UK
| |
Collapse
|
58
|
Carta MG, Moro MF, Nardi AE, Calabrese JR. Potential use of lurasidone for the treatment of bipolar psychosis. Expert Opin Investig Drugs 2015; 24:575-84. [PMID: 25633339 DOI: 10.1517/13543784.2015.1009976] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Second-generation antipsychotics (SGA) are new treatment options for bipolar disorders (BDs). Lurasidone is one such SGA, which is currently approved as a monotherapy for bipolar I depression (BPID) and as an add-on therapy for acute schizophrenia. AREAS COVERED In this drug evaluation, the authors illustrate the pharmacological profile of lurasidone and review its development history. The aim of this review is to evaluate whether this compound could be used in psychotic BDs. EXPERT OPINION The pharmacological profile of lurasidone, its action on receptors, its role in neurogenesis and its cognitive performance suggests a potential use in psychotic episodes of BDs and mania. This hypothesis is also supported by the clinical observations from case reports concerning resolutions of BPID with psychotic features, where psychotic episodes were diagnosed as schizophrenia and reclassified as BDs after the patient was able to reconstruct his/her clinical history. The use of lurasidone may have the advantage of a low side-effect profile and a possible efficacy in preventing the impairment of cognitive performance. However, randomized clinical trials assessing the efficacy of lurasidone in the treatment of manic episodes as well as manic episodes with psychotic components are still needed.
Collapse
Affiliation(s)
- Mauro Giovanni Carta
- University of Cagliari, Department of Public Health, Clinical and Molecular Medicine , Cagliari , Italy
| | | | | | | |
Collapse
|
59
|
Halberstadt AL. Recent advances in the neuropsychopharmacology of serotonergic hallucinogens. Behav Brain Res 2015; 277:99-120. [PMID: 25036425 PMCID: PMC4642895 DOI: 10.1016/j.bbr.2014.07.016] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 12/12/2022]
Abstract
Serotonergic hallucinogens, such as (+)-lysergic acid diethylamide, psilocybin, and mescaline, are somewhat enigmatic substances. Although these drugs are derived from multiple chemical families, they all produce remarkably similar effects in animals and humans, and they show cross-tolerance. This article reviews the evidence demonstrating the serotonin 5-HT2A receptor is the primary site of hallucinogen action. The 5-HT2A receptor is responsible for mediating the effects of hallucinogens in human subjects, as well as in animal behavioral paradigms such as drug discrimination, head twitch response, prepulse inhibition of startle, exploratory behavior, and interval timing. Many recent clinical trials have yielded important new findings regarding the psychopharmacology of these substances. Furthermore, the use of modern imaging and electrophysiological techniques is beginning to help unravel how hallucinogens work in the brain. Evidence is also emerging that hallucinogens may possess therapeutic efficacy.
Collapse
Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States.
| |
Collapse
|
60
|
The role of 5-HT2A, 5-HT 2C and mGlu2 receptors in the behavioral effects of tryptamine hallucinogens N,N-dimethyltryptamine and N,N-diisopropyltryptamine in rats and mice. Psychopharmacology (Berl) 2015; 232:275-84. [PMID: 24985890 PMCID: PMC4282596 DOI: 10.1007/s00213-014-3658-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/10/2014] [Indexed: 12/25/2022]
Abstract
RATIONALE Serotonin 5-HT2A and 5-HT2C receptors are thought to be the primary pharmacological mechanisms for serotonin-mediated hallucinogenic drugs, but recently there has been interest in metabotropic glutamate (mGluR2) receptors as contributors to the mechanism of hallucinogens. OBJECTIVE The present study assesses the role of these 5-HT and glutamate receptors as molecular targets for two tryptamine hallucinogens, N,N-dimethyltryptamine (DMT) and N,N-diisopropyltryptamine (DiPT). METHODS Drug discrimination, head twitch, and radioligand binding assays were used. A 5-HT2AR inverse agonist (MDL100907), 5-HT2CR antagonist (SB242084), and mGluR2/3 agonist (LY379268) were tested for their ability to attenuate the discriminative stimulus effects of DMT and DiPT; an mGluR2/3 antagonist (LY341495) was tested for potentiation. MDL100907 was used to attenuate head twitches induced by DMT and DiPT. Radioligand binding studies and inosital-1-phosphate (IP-1) accumulation were performed at the 5-HT2CR for DiPT. RESULTS MDL100907 fully blocked the discriminative stimulus effects of DMT, but only partially blocked DiPT. SB242084 partially attenuated the discriminative stimulus effects of DiPT, but produced minimal attenuation of DMT's effects. LY379268 produced potent, but only partial blockade of the discriminative stimulus effects of DMT. LY341495 facilitated DMT- and DiPT-like effects. Both compounds elicited head twitches (DiPT>DMT) which were blocked by MDL1000907. DiPT was a low-potency full agonist at 5-HT2CR in vitro. CONCLUSIONS The 5-HT2AR likely plays a major role in mediating the effects of both compounds. 5-HT2C and mGluR2 receptors likely modulate the discriminative stimulus effects of both compounds to some degree.
Collapse
|
61
|
Blough BE, Landavazo A, Decker AM, Partilla JS, Baumann MH, Rothman RB. Interaction of psychoactive tryptamines with biogenic amine transporters and serotonin receptor subtypes. Psychopharmacology (Berl) 2014; 231:4135-44. [PMID: 24800892 PMCID: PMC4194234 DOI: 10.1007/s00213-014-3557-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 03/19/2014] [Indexed: 01/10/2023]
Abstract
RATIONALE Synthetic hallucinogenic tryptamines, especially those originally described by Alexander Shulgin, continue to be abused in the USA. The range of subjective experiences produced by different tryptamines suggests that multiple neurochemical mechanisms are involved in their actions, in addition to the established role of agonist activity at serotonin 2A (5-HT₂A) receptors. OBJECTIVES This study evaluated the interaction of a series of synthetic tryptamines with biogenic amine neurotransmitter transporters and with serotonin (5-HT) receptor subtypes implicated in psychedelic effects. METHODS Neurotransmitter transporter activity was determined in rat brain synaptosomes. Receptor activity was determined using calcium mobilization and DiscoveRx PathHunter assays in HEK293, Gα16-CHO, and CHOk1 cells transfected with human receptors. RESULTS Twenty-one tryptamines were analyzed in transporter uptake and release assays, and 5-HT₂A, serotonin 1A (5-HT₁A), and 5-HT₂A β-arrestin functional assays. Eight of the compounds were found to have 5-HT-releasing activity. Thirteen compounds were found to be 5-HT uptake inhibitors or were inactive. All tryptamines were 5-HT₂A agonists with a range of potencies and efficacies, but only a few compounds were 5-HT1A agonists. Most tryptamines recruited β-arrestin through 5-HT₂A activation. CONCLUSIONS All psychoactive tryptamines are 5-HT₂A agonists, but 5-HT transporter (SERT) activity may contribute significantly to the pharmacology of certain compounds. The in vitro transporter data confirm structure-activity trends for releasers and uptake inhibitors whereby releasers tend to be structurally smaller compounds. Interestingly, two tertiary amines were found to be selective substrates at SERT, which dispels the notion that 5-HT-releasing activity is limited only to primary or secondary amines.
Collapse
Affiliation(s)
- Bruce E. Blough
- Discovery Science Technology, RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA,Corresponding author. Tel.: 919-541-1244; fax: 919-541-6499;
| | - Antonio Landavazo
- Discovery Science Technology, RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Ann M. Decker
- Discovery Science Technology, RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - John S. Partilla
- Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Michael H. Baumann
- Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Richard B. Rothman
- Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| |
Collapse
|
62
|
N-acetylcysteine modulates hallucinogenic 5-HT2A receptor agonist-mediated responses: Behavioral, molecular, and electrophysiological studies. Neuropharmacology 2014; 81:215-23. [DOI: 10.1016/j.neuropharm.2014.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 01/10/2014] [Accepted: 02/06/2014] [Indexed: 01/01/2023]
|
63
|
Luoni A, Rocha FF, Riva MA. Anatomical specificity in the modulation of activity-regulated genes after acute or chronic lurasidone treatment. Prog Neuropsychopharmacol Biol Psychiatry 2014; 50:94-101. [PMID: 24361635 DOI: 10.1016/j.pnpbp.2013.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/04/2013] [Accepted: 12/13/2013] [Indexed: 01/04/2023]
Abstract
Lurasidone is a novel second generation antipsychotic drug characterized by a multi-receptor profile. Besides the high affinity for 5-HT2A and D2 receptors, it is also characterized by potent 5-HT7 receptor antagonism, which may be beneficial for mood and cognition. Considering that dose-dependent changes in receptor occupancy may differentially impact gene transcription, we aimed at investigating the effects of acute and chronic treatments with different doses of lurasidone (1, 3 and 10mg/kg) in rats on the expression of the activity-regulated genes Arc, Zif268 and Npas4, which are markers of neuronal activation and are also associated with neuroadaptive mechanisms. Our results show dose-dependent and anatomically-selective differences after acute and chronic lurasidone treatment. Indeed, the effects produced by acute treatment seem to reflect the modulatory activity of lurasidone at selected neurotransmitter receptors. In fact, low doses of the drug acted in the hippocampus, while high doses acted in the striatum, reflecting the high predominance of D2 receptor expression in this brain region. On the contrary, chronic treatment with lurasidone revealed a different profile of IEGs modulation, possibly reflecting neuroadaptive changes set in motion in response to repetitive drug exposure. In summary, the multi-receptor profile of lurasidone leads to the recruitment of different brain structures in a dose-related manner and this may be important for its therapeutic properties, particularly with respect to antidepressant activity and cognition.
Collapse
Affiliation(s)
- Alessia Luoni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, I-20133 Milan, Italy
| | - Fabio F Rocha
- Department of Pharmacological and Biomolecular Sciences, University of Milan, I-20133 Milan, Italy
| | - Marco A Riva
- Department of Pharmacological and Biomolecular Sciences, University of Milan, I-20133 Milan, Italy; Center of Excellence on Neurodegenerative Diseases, University of Milan, I-20133 Milan, Italy.
| |
Collapse
|
64
|
Fuxe K, Borroto-Escuela DO, Tarakanov AO, Romero-Fernandez W, Ferraro L, Tanganelli S, Perez-Alea M, Di Palma M, Agnati LF. Dopamine D2 heteroreceptor complexes and their receptor-receptor interactions in ventral striatum: novel targets for antipsychotic drugs. PROGRESS IN BRAIN RESEARCH 2014; 211:113-39. [PMID: 24968778 DOI: 10.1016/b978-0-444-63425-2.00005-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review is focused on the D2 heteroreceptor complexes within the ventral striatum with their receptor-receptor interactions and relevance for the treatment of schizophrenia. A "guide-and-clasp" manner for receptor-receptor interactions is proposed where "adhesive guides" may be amino acid triplet homologies, which were determined for different kinds of D2 heteroreceptor complexes. The first putative D2 heteroreceptor complex to be discovered in relation to schizophrenia was the A2A-D2 heteroreceptor complex where antagonistic A2A-D2 receptor-receptor interactions were demonstrated after A2A agonist treatment in the ventral striatum. The A2A agonist CGS 21680 with atypical antipsychotic properties may at least in part act by increasing β-arrestin2 signaling over the D2 protomer in the A2A-D2 heteroreceptor complex in the ventral striatum. The antagonistic NTS1-D2 interactions in the NTS1-D2 heteroreceptor complex in the ventral striatum are proposed as one molecular mechanism for the potential antipsychotic effects of NT. Indications were obtained that the psychotic actions of the 5-HT2AR hallucinogens LSD and DOI can involve enhancement of D2R protomer signaling via a biased agonist action at the 5-HT2A protomer in the D2-5-HT2A heteroreceptor complex in the ventral striatum. Facilitatory allosteric D2likeR-OTR interactions in heteroreceptor complexes in nucleus accumbens may have a role in social and emotional behaviors. By blocking the D2 protomers of these heteroreceptor complexes, antipsychotics can fail to reduce the negative symptoms of schizophrenia. The discovery of different types of D2 heteroreceptor complexes gives an increased understanding of molecular mechanisms involved in causing schizophrenia and new strategies for its treatment and understanding the side effects of antipsychotics.
Collapse
Affiliation(s)
- Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | | | - Alexander O Tarakanov
- Russian Academy of Sciences, St Petersburg Institute for Informatics and Automatation, St. Petersburg, Russia
| | | | - Luca Ferraro
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Sergio Tanganelli
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mileidys Perez-Alea
- Department of Pathology, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Michael Di Palma
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Earth, Life and Environmental Sciences, Section of Physiology, Campus Scientifico 'Enrico Mattei', Urbino, Italy
| | | |
Collapse
|
65
|
Abstract
One of the oldest models of schizophrenia is based on the effects of serotonergic hallucinogens such as mescaline, psilocybin, and (+)-lysergic acid diethylamide (LSD), which act through the serotonin 5-HT(2A) receptor. These compounds produce a 'model psychosis' in normal individuals that resembles at least some of the positive symptoms of schizophrenia. Based on these similarities, and because evidence has emerged that the serotonergic system plays a role in the pathogenesis of schizophrenia in some patients, animal models relevant to schizophrenia have been developed based on hallucinogen effects. Here we review the behavioural effects of hallucinogens in four of those models, the receptor and neurochemical mechanisms for the effects and their translational relevance. Despite the difficulty of modelling hallucinogen effects in nonverbal species, animal models of schizophrenia based on hallucinogens have yielded important insights into the linkage between 5-HT and schizophrenia and have helped to identify receptor targets and interactions that could be exploited in the development of new therapeutic agents.
Collapse
|
66
|
Jørgensen CV, Jacobsen JP, Caron MG, Klein AB, Knudsen GM, Mikkelsen JD. Cerebral 5-HT2A receptor binding, but not mGluR2, is increased in tryptophan hydroxylase 2 decrease-of-function mice. Neurosci Lett 2013; 555:118-22. [PMID: 24055299 DOI: 10.1016/j.neulet.2013.08.073] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/05/2013] [Accepted: 08/30/2013] [Indexed: 12/22/2022]
Abstract
Transgenic mice with a knock-in (KI) of a tryptophan hydroxylase 2 (Tph2) R439H mutation, analogous to the Tph2 R441H single-nucleotide polymorphism originally identified in a late life depression cohort, have markedly reduced levels of 5-hydroxytryptamine (5-HT). These Tph2KI mice are therefore interesting as a putative translational model of low endogenous 5-HT function that allows for assessment of adaptive changes in different anatomical regions. Here, we determined 5-HT2A receptor binding in several brain regions using in vitro receptor autoradiography and two different radioligands. When using the 5-HT2A receptor selective antagonist radioligand (3)H-MDL100907, we found higher binding in the prefrontal cortex (10%, P=0.009), the striatum (26%, P=0.005), and the substantia nigra (21%, P=0.027). The increase was confirmed in the same regions with the 5-HT2A/C receptor agonist, (3)H-CIMBI-36 (2-(4-Bromo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine). 5-HT2A receptors establish heteromeric receptor complexes with metabotropic glutamate 2 receptors (mGluR2), but binding levels of the mGluR2/3 ligand (3)H-LY341495 were unaltered in brain areas with increased 5-HT2A receptor levels. These data show that in distinct anatomical regions, 5-HT2A receptor binding sites are up-regulated in 5-HT deficient mice, and this increase is not associated with changes in mGluR2 binding.
Collapse
|
67
|
Palczewski K, Orban T. From atomic structures to neuronal functions of g protein-coupled receptors. Annu Rev Neurosci 2013; 36:139-64. [PMID: 23682660 DOI: 10.1146/annurev-neuro-062012-170313] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) are essential mediators of signal transduction, neurotransmission, ion channel regulation, and other cellular events. GPCRs are activated by diverse stimuli, including light, enzymatic processing of their N-termini, and binding of proteins, peptides, or small molecules such as neurotransmitters. GPCR dysfunction caused by receptor mutations and environmental challenges contributes to many neurological diseases. Moreover, modern genetic technology has helped identify a rich array of mono- and multigenic defects in humans and animal models that connect such receptor dysfunction with disease affecting neuronal function. The visual system is especially suited to investigate GPCR structure and function because advanced imaging techniques permit structural studies of photoreceptor neurons at both macro and molecular levels that, together with biochemical and physiological assessment in animal models, provide a more complete understanding of GPCR signaling.
Collapse
Affiliation(s)
- Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4965, USA.
| | | |
Collapse
|
68
|
Milligan G. The prevalence, maintenance, and relevance of G protein-coupled receptor oligomerization. Mol Pharmacol 2013; 84:158-69. [PMID: 23632086 DOI: 10.1124/mol.113.084780] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Over the past decade, ideas and experimental support for the hypothesis that G protein-coupled receptors may exist as dimeric or oligomeric complexes moved initially from heresy to orthodoxy, to the current situation in which the capacity of such receptors to interact is generally accepted but the prevalence, maintenance, and relevance of such interactions to both pharmacology and function remain unclear. A vast body of data obtained following transfection of cultured cells is still to be translated to native systems and, even where this has been attempted, results often remain controversial and contradictory. This review will consider approaches that are currently being applied and why these might be challenging to interpret, and will suggest means to overcome these limitations.
Collapse
Affiliation(s)
- Graeme Milligan
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
| |
Collapse
|
69
|
Delille HK, Mezler M, Marek GJ. The two faces of the pharmacological interaction of mGlu2 and 5-HT₂A - relevance of receptor heterocomplexes and interaction through functional brain pathways. Neuropharmacology 2013; 70:296-305. [PMID: 23466331 DOI: 10.1016/j.neuropharm.2013.02.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/01/2013] [Accepted: 02/04/2013] [Indexed: 11/28/2022]
Abstract
Important functional interactions between the metabotropic glutamate 2 (mGlu2) and 5-hydroxytryptamine2A (5-HT₂A) neurotransmitter receptors have been established based on electrophysiological, biochemical and behavioral evidence. Over the last several years, dimerization between 5-HT₂A and mGlu2 receptors has been proposed to account for the functional cross-talk between these two receptors in the prefrontal cortex. The pros and cons for the existence of a heteromeric complex between 5-HT₂A and mGlu2 receptors will be reviewed here. First, the fundamental criteria needing to establish evidence for heteromeric complexes will be reviewed. Then, the in vitro evidence for and against heteromeric complexes between 5-HT₂A and mGlu2 receptors will be discussed in regard to physical and functional interactions. Finally, the data with native in situ mGlu2 and 5-HT₂A receptors will be discussed with respect to whether heteromeric complexes or a simple functional interaction between two distinct GPCRs based on brain network activity is the more simple explanation for a range of in vivo data.
Collapse
Affiliation(s)
- Hannah K Delille
- Abbott Diagnostics Division, Max-Planck-Ring 2, 65205 Wiesbaden, Germany
| | | | | |
Collapse
|
70
|
Serotonin-glutamate and serotonin-dopamine reciprocal interactions as putative molecular targets for novel antipsychotic treatments: from receptor heterodimers to postsynaptic scaffolding and effector proteins. Psychopharmacology (Berl) 2013. [PMID: 23179966 DOI: 10.1007/s00213-012-2921-8] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The physical and functional interactions between serotonin-glutamate and serotonin-dopamine signaling have been suggested to be involved in psychosis pathophysiology and are supposed to be relevant for antipsychotic treatment. Type II metabotropic glutamate receptors (mGluRs) and serotonin 5-HT(2A) receptors have been reported to form heterodimers that modulate G-protein-mediated intracellular signaling differentially compared to mGluR2 and 5-HT(2A) homomers. Additionally, direct evidence has been provided that D(2) and 5-HT(2A) receptors form physical heterocomplexes which exert a functional cross-talk, as demonstrated by studies on hallucinogen-induced signaling. Moving from receptors to postsynaptic density (PSD) scenario, the scaffolding protein PSD-95 is known to interact with N-methyl-D-aspartate (NMDA), D(2) and 5-HT(2) receptors, regulating their activation state. Homer1a, the inducible member of the Homer family of PSD proteins that is implicated in glutamatergic signal transduction, is induced in striatum by antipsychotics with high dopamine receptor affinity and in the cortex by antipsychotics with mixed serotonergic/dopaminergic profile. Signaling molecules, such as Akt and glycogen-synthase-kinase-3 (GSK-3), could be involved in the mechanism of action of antipsychotics, targeting dopamine, serotonin, and glutamate neurotransmission. Altogether, these proteins stand at the crossroad of glutamate-dopamine-serotonin signaling pathways and may be considered as valuable molecular targets for current and new antipsychotics. The aim of this review is to provide a critical appraisal on serotonin-glutamate and serotonin-dopamine interplay to support the idea that next generation schizophrenia pharmacotherapy should not exclusively rely on receptor targeting strategies.
Collapse
|
71
|
Schellekens H, van Oeffelen WEPA, Dinan TG, Cryan JF. Promiscuous dimerization of the growth hormone secretagogue receptor (GHS-R1a) attenuates ghrelin-mediated signaling. J Biol Chem 2012; 288:181-91. [PMID: 23161547 DOI: 10.1074/jbc.m112.382473] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
G protein-coupled receptors (GPCRs), such as the ghrelin receptor (GHS-R1a), the melanocortin 3 receptor (MC(3)), and the serotonin 2C receptor (5-HT(2C)), are well known for their key role in the homeostatic control of food intake and energy balance. Ghrelin is the only known gut peptide exerting an orexigenic effect and has thus received much attention as an anti-obesity drug target. In addition, recent data have revealed a critical role for ghrelin in dopaminergic mesolimbic circuits involved in food reward signaling. This study investigates the downstream signaling consequences and ligand-mediated co-internalization following heterodimerization of the GHS-R1a receptor with the dopamine 1 receptor, as well as that of the GHS-R1a-MC(3) heterodimer. In addition, a novel heterodimer between the GHS-R1a receptor and the 5-HT(2C) receptor was identified. Interestingly, dimerization of the GHS-R1a receptor with the unedited 5-HT(2C)-INI receptor, but not with the partially edited 5-HT(2C)-VSV isoform, significantly reduced GHS-R1a agonist-mediated calcium influx, which was completely restored following pharmacological blockade of the 5-HT(2C) receptor. These results combined suggest a potential novel mechanism for fine-tuning GHS-R1a receptor-mediated activity via promiscuous dimerization of the GHS-R1a receptor with other G protein-coupled receptors involved in appetite regulation and food reward. These findings may uncover novel mechanisms of significant relevance for the future pharmacological targeting of the GHS-R1a receptor in the homeostatic regulation of energy balance and in hedonic appetite signaling, both of which play a significant role in the development of obesity.
Collapse
|
72
|
Masharina A, Reymond L, Maurel D, Umezawa K, Johnsson K. A Fluorescent Sensor for GABA and Synthetic GABAB Receptor Ligands. J Am Chem Soc 2012; 134:19026-34. [DOI: 10.1021/ja306320s] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Anastasiya Masharina
- Institute of Chemical
Sciences and Engineering (ISIC),
Institute of Bioengineering, NCCR in Chemical Biology, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Luc Reymond
- Institute of Chemical
Sciences and Engineering (ISIC),
Institute of Bioengineering, NCCR in Chemical Biology, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Damien Maurel
- Institute of Chemical
Sciences and Engineering (ISIC),
Institute of Bioengineering, NCCR in Chemical Biology, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Keitaro Umezawa
- Institute of Chemical
Sciences and Engineering (ISIC),
Institute of Bioengineering, NCCR in Chemical Biology, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Kai Johnsson
- Institute of Chemical
Sciences and Engineering (ISIC),
Institute of Bioengineering, NCCR in Chemical Biology, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| |
Collapse
|
73
|
Cottet M, Faklaris O, Maurel D, Scholler P, Doumazane E, Trinquet E, Pin JP, Durroux T. BRET and Time-resolved FRET strategy to study GPCR oligomerization: from cell lines toward native tissues. Front Endocrinol (Lausanne) 2012; 3:92. [PMID: 22837753 PMCID: PMC3401989 DOI: 10.3389/fendo.2012.00092] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/03/2012] [Indexed: 11/13/2022] Open
Abstract
The concept of oligomerization of G protein-coupled receptor (GPCR) opens new perspectives regarding physiological function regulation. The capacity of one GPCR to modify its binding and coupling properties by interacting with a second one can be at the origin of regulations unsuspected two decades ago. Although the concept is interesting, its validation at a physiological level is challenging and probably explains why receptor oligomerization is still controversial. Demonstrating direct interactions between two proteins is not trivial since few techniques present a spatial resolution allowing this precision. Resonance energy transfer (RET) strategies are actually the most convenient ones. During the last two decades, bioluminescent resonance energy transfer and time-resolved fluorescence resonance energy transfer (TR-FRET) have been widely used since they exhibit high signal-to-noise ratio. Most of the experiments based on GPCR labeling have been performed in cell lines and it has been shown that all GPCRs have the propensity to form homo- or hetero-oligomers. However, whether these data can be extrapolated to GPCRs expressed in native tissues and explain receptor functioning in real life, remains an open question. Native tissues impose different constraints since GPCR sequences cannot be modified. Recently, a fluorescent ligand-based GPCR labeling strategy combined to a TR-FRET approach has been successfully used to prove the existence of GPCR oligomerization in native tissues. Although the RET-based strategies are generally quite simple to implement, precautions have to be taken before concluding to the absence or the existence of specific interactions between receptors. For example, one should exclude the possibility of collision of receptors diffusing throughout the membrane leading to a specific FRET signal. The advantages and the limits of different approaches will be reviewed and the consequent perspectives discussed.
Collapse
Affiliation(s)
- Martin Cottet
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
| | - Orestis Faklaris
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
| | - Damien Maurel
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
| | - Pauline Scholler
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
| | - Etienne Doumazane
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
| | | | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
| | - Thierry Durroux
- Institut de Génomique Fonctionnelle CNRS, UMR 5203,Montpellier, France
- INSERM, U.661, Montpellier and Université Montpellier 1,2,Montpellier, France
- *Correspondence: Thierry Durroux, Institut de Génomique Fonctionnelle CNRS, UMR 5203, Montpellier, France; INSERM U661, Montpellier and Université Montpellier 1,2, 141 Rue de la Cardonille, 34094 Montpellier Cedex 5, France. e-mail:
| |
Collapse
|
74
|
Conn PJ, Kuduk SD, Doller D. Drug Design Strategies for GPCR Allosteric Modulators. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2012; 47:441-457. [PMID: 26962268 PMCID: PMC4780677 DOI: 10.1016/b978-0-12-396492-2.00028-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- P Jeffrey Conn
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Scott D Kuduk
- Department of Medicinal Chemistry, Merck Research Laboratories, West Point, Pennsylvania, USA
| | - Darío Doller
- Discovery Chemistry & DMPK, Lundbeck Research DK, Valby, Denmark and Neuroinflammation Disease Biology Unit, Lundbeck Research USA, Paramus, New Jersey, USA
| |
Collapse
|
75
|
Abstract
A variety of serotonin (5-HT) receptors, especially 5-HT(2A), 5-HT(1A), 5-HT(6), 5-HT(7), and 5-HT(2C), have been postulated to contribute to the mechanism of action of atypical antipsychotic drugs (APDs), i.e., APDs which cause fewer extrapyramidal side effects (EPS) at clinically optimal doses, in contrast with typical APDs, which are more likely to cause EPS. This advantage, rarely disputed, has made such drugs the preferred treatment for schizophrenia and other indications for APDs. These 5-HT receptors are still of interest as components of novel multireceptor or stand-alone APDs, and potentially to remediate cognitive deficits in schizophrenia. Almost all currently available atypical APDs are 5-HT(2A) receptor inverse agonists, as well as dopamine (DA) D(2) receptor antagonists or partial agonists. Amisulpride, an exceptional atypical APD, has 5-HT(7) antagonism to complement its DA D(2/3) antagonism. Some atypical APDs are also 5-HT(1A) partial agonists, 5-HT(6), or 5-HT(7) antagonists, or some combination of the above. 5-HT(2C) antagonism has been found to contribute to the metabolic side effects of some atypical APDs, whereas 5-HT(2C) agonists have potential as stand-alone APDs and/or cognitive enhancers. This review will provide an update of current preclinical and clinical evidence for the role of these five 5-HT receptors in the actions of current APDs and for the development of novel psychotropic drugs.
Collapse
Affiliation(s)
- Herbert Y Meltzer
- Department of Psychiatry and Behavioral Sciences, Northwestern Feinberg School of Medicine, Chicago, IL 60611, USA.
| |
Collapse
|