1
|
Keifi Bajestani A, Alavi MS, Etemad L, Roohbakhsh A. Role of orphan G-protein coupled receptors in tissue ischemia: A comprehensive review. Eur J Pharmacol 2024; 978:176762. [PMID: 38906238 DOI: 10.1016/j.ejphar.2024.176762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 06/12/2024] [Accepted: 06/19/2024] [Indexed: 06/23/2024]
Abstract
Ischemic events lead to many diseases and deaths worldwide. Ischemia/reperfusion (I/R) occurs due to reduced blood circulation in tissues followed by blood reflow. Reoxygenation of ischemic tissues is characterized by oxidative stress, inflammation, energy distress, and endoplasmic reticulum stress. There are still no adequate clinical protocols or pharmacological approaches to address the consequences of I/R damage. G protein-coupled receptors (GPCRs) are important therapeutic targets. They compose a large family of seven transmembrane-spanning proteins that are involved in many biological functions. Orphan GPCRs are a large subgroup of these receptors expressed in different organs. In the present review, we summarized the literature regarding the role of orphan GPCRs in I/R in different organs. We focused on the effect of these receptors on modulating cellular and molecular processes underlying ischemia including apoptosis, inflammation, and autophagy. The study showed that GPR3, GPR4, GPR17, GPR30, GPR31, GPR35, GPR37, GPR39, GPR55, GPR65, GPR68, GPR75, GPR81, and GPR91 are involved in ischemic events, mainly in the brain and heart. These receptors offer new possibilities for treating I/R injuries in the body.
Collapse
Affiliation(s)
- Alireza Keifi Bajestani
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohaddeseh Sadat Alavi
- Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Leila Etemad
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Roohbakhsh
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
2
|
Lu Y, Hatzipantelis CJ, Langmead CJ, Stewart GD. Molecular insights into orphan G protein-coupled receptors relevant to schizophrenia. Br J Pharmacol 2024; 181:2095-2113. [PMID: 37605621 DOI: 10.1111/bph.16221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/25/2023] [Accepted: 07/23/2023] [Indexed: 08/23/2023] Open
Abstract
Schizophrenia remains a sizable socio-economic burden that continues to be treated with therapeutics based on 70-year old science. All currently approved therapeutics primarily target the dopamine D2 receptor to achieve their efficacy. Whilst dopaminergic dysregulation is a key feature in this disorder, the targeting of dopaminergic machinery has yielded limited efficacy and an appreciable side effect burden. Over the recent decades, numerous drugs that engage non-dopaminergic G protein-coupled receptors (GPCRs) have yielded a promise of efficacy without the deleterious side effect profile, yet none have successfully completed clinical studies and progressed to the market. More recently, there has been increased attention around non-dopaminergic GPCR-targeting drugs, which demonstrated efficacy in some schizophrenia symptom domains. This provides renewed hope that effective schizophrenia treatment may lie outside of the dopaminergic space. Despite the potential for muscarinic receptor- (and other well-characterised GPCR families) targeting drugs to treat schizophrenia, they are often plagued with complications such as lack of receptor subtype selectivity and peripheral on-target side effects. Orphan GPCR studies have opened a new avenue of exploration with many demonstrating schizophrenia-relevant mechanisms and a favourable expression profile, thus offering potential for novel drug development. This review discusses centrally expressed orphan GPCRs: GPR3, GPR6, GPR12, GPR52, GPR85, GPR88 and GPR139 and their relationship to schizophrenia. We review their expression, signalling mechanisms and cellular function, in conjunction with small molecule development and structural insights. We seek to provide a snapshot of the growing evidence and development potential of new classes of schizophrenia therapeutics. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
Collapse
Affiliation(s)
- Yao Lu
- Drug Discovery Biology and Neuroscience & Mental Health Therapeutic Program Area, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
| | | | - Christopher J Langmead
- Drug Discovery Biology and Neuroscience & Mental Health Therapeutic Program Area, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Neuromedicines Discovery Centre, Monash University, Parkville, Australia
- Phrenix Therapeutics, Parkville, Australia
| | - Gregory D Stewart
- Drug Discovery Biology and Neuroscience & Mental Health Therapeutic Program Area, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
- Neuromedicines Discovery Centre, Monash University, Parkville, Australia
- Phrenix Therapeutics, Parkville, Australia
| |
Collapse
|
3
|
Öz-Arslan D, Yavuz M, Kan B. Exploring orphan GPCRs in neurodegenerative diseases. Front Pharmacol 2024; 15:1394516. [PMID: 38895631 PMCID: PMC11183337 DOI: 10.3389/fphar.2024.1394516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
Neurodegenerative disorders represent a significant and growing health burden worldwide. Unfortunately, limited therapeutic options are currently available despite ongoing efforts. Over the past decades, research efforts have increasingly focused on understanding the molecular mechanisms underlying these devastating conditions. Orphan receptors, a class of receptors with no known endogenous ligands, emerge as promising druggable targets for diverse diseases. This review aims to direct attention to a subgroup of orphan GPCRs, in particular class A orphans that have roles in neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and Multiple sclerosis. We highlight the diverse roles orphan receptors play in regulating critical cellular processes such as synaptic transmission, neuronal survival and neuro-inflammation. Moreover, we discuss the therapeutic potential of targeting orphan receptors for the treatment of neurodegenerative disorders, emphasizing recent advances in drug discovery and preclinical studies. Finally, we outline future directions and challenges in orphan receptor research.
Collapse
Affiliation(s)
- Devrim Öz-Arslan
- Department of Biophysics, Acibadem MAA University, School of Medicine, Istanbul, Türkiye
- Department of Neurosciences, Acibadem MAA University, Institute of Health Sciences, İstanbul, Türkiye
| | - Melis Yavuz
- Department of Neurosciences, Acibadem MAA University, Institute of Health Sciences, İstanbul, Türkiye
- Department of Pharmacology, Acibadem MAA University, School of Pharmacy, Istanbul, Türkiye
| | - Beki Kan
- Department of Biophysics, Acibadem MAA University, School of Medicine, Istanbul, Türkiye
- Department of Neurosciences, Acibadem MAA University, Institute of Health Sciences, İstanbul, Türkiye
| |
Collapse
|
4
|
Birgül Iyison N, Abboud C, Abboud D, Abdulrahman AO, Bondar AN, Dam J, Georgoussi Z, Giraldo J, Horvat A, Karoussiotis C, Paz-Castro A, Scarpa M, Schihada H, Scholz N, Güvenc Tuna B, Vardjan N. ERNEST COST action overview on the (patho)physiology of GPCRs and orphan GPCRs in the nervous system. Br J Pharmacol 2024. [PMID: 38825750 DOI: 10.1111/bph.16389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 02/09/2024] [Accepted: 02/24/2024] [Indexed: 06/04/2024] Open
Abstract
G protein-coupled receptors (GPCRs) are a large family of cell surface receptors that play a critical role in nervous system function by transmitting signals between cells and their environment. They are involved in many, if not all, nervous system processes, and their dysfunction has been linked to various neurological disorders representing important drug targets. This overview emphasises the GPCRs of the nervous system, which are the research focus of the members of ERNEST COST action (CA18133) working group 'Biological roles of signal transduction'. First, the (patho)physiological role of the nervous system GPCRs in the modulation of synapse function is discussed. We then debate the (patho)physiology and pharmacology of opioid, acetylcholine, chemokine, melatonin and adhesion GPCRs in the nervous system. Finally, we address the orphan GPCRs, their implication in the nervous system function and disease, and the challenges that need to be addressed to deorphanize them.
Collapse
Affiliation(s)
- Necla Birgül Iyison
- Department of Molecular Biology and Genetics, University of Bogazici, Istanbul, Turkey
| | - Clauda Abboud
- Laboratory of Molecular Pharmacology, GIGA-Molecular Biology of Diseases, University of Liege, Liege, Belgium
| | - Dayana Abboud
- Laboratory of Molecular Pharmacology, GIGA-Molecular Biology of Diseases, University of Liege, Liege, Belgium
| | | | - Ana-Nicoleta Bondar
- Faculty of Physics, University of Bucharest, Magurele, Romania
- Forschungszentrum Jülich, Institute for Computational Biomedicine (IAS-5/INM-9), Jülich, Germany
| | - Julie Dam
- Institut Cochin, CNRS, INSERM, Université Paris Cité, Paris, France
| | - Zafiroula Georgoussi
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos", Athens, Greece
| | - Jesús Giraldo
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Madrid, Spain
- Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Anemari Horvat
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Christos Karoussiotis
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos", Athens, Greece
| | - Alba Paz-Castro
- Molecular Pharmacology of GPCRs research group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Santiago, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Santiago, Spain
| | - Miriam Scarpa
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Hannes Schihada
- Department of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Nicole Scholz
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Bilge Güvenc Tuna
- Department of Biophysics, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Nina Vardjan
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| |
Collapse
|
5
|
Xiong Y, Xu Z, Li X, Wang Y, Zhao J, Wang N, Duan Y, Xia R, Han Z, Qian Y, Liang J, Zhang A, Guo C, Inoue A, Xia Y, Chen Z, He Y. Identification of oleic acid as an endogenous ligand of GPR3. Cell Res 2024; 34:232-244. [PMID: 38287117 PMCID: PMC10907358 DOI: 10.1038/s41422-024-00932-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 01/11/2024] [Indexed: 01/31/2024] Open
Abstract
Although GPR3 plays pivotal roles in both the nervous system and metabolic processes, such as cold-induced thermogenesis, its endogenous ligand remains elusive. Here, by combining structural approach (including cryo-electron microscopy), mass spectrometry analysis, and functional studies, we identify oleic acid (OA) as an endogenous ligand of GPR3. Our study reveals a hydrophobic tunnel within GPR3 that connects the extracellular side of the receptor to the middle of plasma membrane, enabling fatty acids to readily engage the receptor. Functional studies demonstrate that OA triggers downstream Gs signaling, whereas lysophospholipids fail to activate the receptor. Moreover, our research reveals that cold stimulation induces the secretion of OA in mice, subsequently activating Gs/cAMP/PKA signaling in brown adipose tissue. Notably, brown adipose tissues from Gpr3 knockout mice do not respond to OA during cold stimulation, reinforcing the significance of GPR3 in this process. Finally, we propose a "born to be activated and cold to enhance" model for GPR3 activation. Our study provides a starting framework for the understanding of GPR3 signaling in cold-stimulated thermogenesis.
Collapse
Affiliation(s)
- Yangjie Xiong
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Zhenmei Xu
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Xinzhi Li
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Yuqin Wang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Jing Zhao
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, China
| | - Na Wang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Yaning Duan
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Ruixue Xia
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Zhengbin Han
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Yu Qian
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Jiale Liang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Anqi Zhang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Changyou Guo
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, Japan
| | - Yu Xia
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, China.
| | - Zheng Chen
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.
- Frontiers Science Center for Matter Behave in Space Environment, Harbin Institute of Technology, Harbin, Heilongjiang, China.
| | - Yuanzheng He
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.
- Frontiers Science Center for Matter Behave in Space Environment, Harbin Institute of Technology, Harbin, Heilongjiang, China.
| |
Collapse
|
6
|
Bresinsky M, Shahraki A, Kolb P, Pockes S, Schihada H. Development of Fluorescent AF64394 Analogues Enables Real-Time Binding Studies for the Orphan Class A GPCR GPR3. J Med Chem 2023; 66:15025-15041. [PMID: 37907069 PMCID: PMC10641823 DOI: 10.1021/acs.jmedchem.3c01707] [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: 09/14/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 11/02/2023]
Abstract
The orphan G protein-coupled receptor (oGPCR) GPR3 represents a potential drug target for the treatment of Alzheimer's disease and metabolic disorders. However, the limited toolbox of pharmacological assays hampers the development of advanced ligands. Here, we developed a signaling pathway-independent readout of compound-GPR3 interaction. Starting from computational binding pose predictions of the most potent GPR3 ligand, we designed a series of fluorescent AF64394 analogues and assessed their suitability for BRET-based binding studies. The most potent ligand, 45 (UR-MB-355), bound to GPR3 and closely related receptors, GPR6 and GPR12, with similar submicromolar affinities. Furthermore, we found that 45 engages GPR3 in a distinct mode compared to AF64394, and coincubation studies with the GPR3 agonist diphenyleneiodonium chloride revealed allosteric modulation of 45 binding. These insights provide new cues for the pharmacological manipulation of GPR3 activity. This novel binding assay will foster the development of future drugs acting through these pharmacologically attractive oGPCRs.
Collapse
Affiliation(s)
- Merlin Bresinsky
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Aida Shahraki
- Department
of Pharmaceutical Chemistry, University
of Marburg, Marbacher Weg 8, 35032 Marburg, Germany
| | - Peter Kolb
- Department
of Pharmaceutical Chemistry, University
of Marburg, Marbacher Weg 8, 35032 Marburg, Germany
| | - Steffen Pockes
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
- Department
of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Hannes Schihada
- Department
of Pharmaceutical Chemistry, University
of Marburg, Marbacher Weg 8, 35032 Marburg, Germany
| |
Collapse
|
7
|
Thakur K, Khan H, Grewal AK, Singh TG. Nuclear orphan receptors: A novel therapeutic agent in neuroinflammation. Int Immunopharmacol 2023; 124:110845. [PMID: 37690241 DOI: 10.1016/j.intimp.2023.110845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/14/2023] [Accepted: 08/20/2023] [Indexed: 09/12/2023]
Abstract
Orphan receptors constitute a historically varied subsection of a superfamily of nuclear receptors. Nuclear receptors regulate gene expression in response to ligand signals and are particularly alluring therapeutic targets for chronic illnesses. Neuroinflammation and neurodegenerative diseases have been linked to these orphan nuclear receptors. Preclinical and clinical evidence suggests that orphan receptors could serve as future targets in neuroinflammation, such as Parkinson's disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), Multiple Sclerosis (MS), and Cerebral Ischemia. Given the therapeutic relevance of certain orphan receptors in a variety of disorders, their potential in neuroinflammation remains unproven. There is substantial evidence that ligand-activated transcription factors have great promise for preventing neurodegenerative and neurological disorders, with certain orphan nuclear receptors i.e., PPARγ, NR4As, and orphan GPCRs holding particularly high potential. Based on previous findings, we attempted to determine the contribution of PPAR, NR4As, and orphan GPCRs-regulated neuroinflammation to the pathogenesis of these disorders and their potential to become novel therapeutic targets.
Collapse
Affiliation(s)
- Kiran Thakur
- Chitkara College of Pharmacy, Chitkara University, 140401 Punjab, India
| | - Heena Khan
- Chitkara College of Pharmacy, Chitkara University, 140401 Punjab, India
| | | | | |
Collapse
|
8
|
Gay EA, Harris DL, Wilson JW, Blough BE. The development of diphenyleneiodonium analogs as GPR3 agonists. Bioorg Med Chem Lett 2023; 94:129427. [PMID: 37541631 PMCID: PMC10631289 DOI: 10.1016/j.bmcl.2023.129427] [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: 06/02/2023] [Revised: 07/20/2023] [Accepted: 07/29/2023] [Indexed: 08/06/2023]
Abstract
G protein-coupled receptor 3 (GPR3) is an orphan receptor potentially involved in many important physiological processes such as drug abuse, neuropathic pain, and anxiety and depression related disorders. Pharmacological studies of GPR3 have been limited due to the restricted number of known agonists and inverse agonists for this constitutively active receptor. In this medicinal chemistry study, we report the discovery of GPR3 agonists based off the diphenyleneiodonium (DPI) scaffold. The most potent full agonist was the 3-trifluoromethoxy analog (32) with an EC50 of 260 nM and 90% efficacy compared to DPI. Investigation of a homology model of GPR3 from multiple sequence alignment resulted in the finding of a binding site rich in potential π-π and π-cation interactions stabilizing DPI-scaffold agonists. MMGBSA free energy analysis showed a good correlation with trends in observed EC50s. DPI analogs retained the same high receptor selectivity for GPR3 over GPR6 and GPR12 as observed with DPI. Collectively, the DPI analog series shows that order of magnitude improvements in potency with the scaffold were attainable; however, attempts to replace the iodonium ion to make the scaffold more druggable failed.
Collapse
Affiliation(s)
- Elaine A Gay
- Center for Drug Discovery, RTI International, Research Triangle Park, NC 27709, USA.
| | - Danni L Harris
- Center for Drug Discovery, RTI International, Research Triangle Park, NC 27709, USA
| | - Joseph W Wilson
- Center for Drug Discovery, RTI International, Research Triangle Park, NC 27709, USA
| | - Bruce E Blough
- Center for Drug Discovery, RTI International, Research Triangle Park, NC 27709, USA
| |
Collapse
|
9
|
Huang Y, Rafael Guimarães T, Todd N, Ferguson C, Weiss KM, Stauffer FR, McDermott B, Hurtle BT, Saito T, Saido TC, MacDonald ML, Homanics GE, Thathiah A. G protein-biased GPR3 signaling ameliorates amyloid pathology in a preclinical Alzheimer's disease mouse model. Proc Natl Acad Sci U S A 2022; 119:e2204828119. [PMID: 36161942 PMCID: PMC9546571 DOI: 10.1073/pnas.2204828119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 08/01/2022] [Indexed: 11/24/2022] Open
Abstract
Biased G protein-coupled receptor (GPCR) ligands, which preferentially activate G protein or β-arrestin signaling pathways, are leading to the development of drugs with superior efficacy and reduced side effects in heart disease, pain management, and neuropsychiatric disorders. Although GPCRs are implicated in the pathophysiology of Alzheimer's disease (AD), biased GPCR signaling is a largely unexplored area of investigation in AD. Our previous work demonstrated that GPR3-mediated β-arrestin signaling modulates amyloid-β (Aβ) generation in vitro and that Gpr3 deficiency ameliorates Aβ pathology in vivo. However, Gpr3-deficient mice display several adverse phenotypes, including elevated anxiety-like behavior, reduced fertility, and memory impairment, which are potentially associated with impaired G protein signaling. Here, we generated a G protein-biased GPR3 mouse model to investigate the physiological and pathophysiological consequences of selective elimination of GPR3-mediated β-arrestin signaling in vivo. In contrast to Gpr3-deficient mice, G protein-biased GPR3 mice do not display elevated anxiety levels, reduced fertility, or cognitive impairment. We further determined that G protein-biased signaling reduces soluble Aβ levels and leads to a decrease in the area and compaction of amyloid plaques in the preclinical AppNL-G-F AD mouse model. The changes in amyloid pathology are accompanied by robust microglial and astrocytic hypertrophy, which suggest a protective glial response that may limit amyloid plaque development in G protein-biased GPR3 AD mice. Collectively, these studies indicate that GPR3-mediated G protein and β-arrestin signaling produce discrete and separable effects and provide proof of concept for the development of safer GPCR-targeting therapeutics with more directed pharmacological action for AD.
Collapse
Affiliation(s)
- Yunhong Huang
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
| | - Thais Rafael Guimarães
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA,15260
| | - Nicholas Todd
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
- Graduate Program in Molecular Pharmacology, University of Pittsburgh, Pittsburgh, PA, 15260
| | - Carolyn Ferguson
- Department of Anesthesiology & Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA, 15260
| | - Kathryn M. Weiss
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
| | - Fiona R. Stauffer
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
| | - Breanne McDermott
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
| | - Bryan T. Hurtle
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA,15260
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, Nagoya, 467-8601, Japan
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, 351-0198, Japan
| | - Takaomi C. Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, 351-0198, Japan
| | - Matthew L. MacDonald
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15260
- Biomedical Mass Spectrometry Center, University of Pittsburgh, Pittsburgh, PA,15260
| | - Gregg E. Homanics
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
- Department of Anesthesiology & Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA, 15260
- University of Pittsburgh Brain Institute, University of Pittsburgh, Pittsburgh, PA, 15260
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15260
| | - Amantha Thathiah
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA,15260
- University of Pittsburgh Brain Institute, University of Pittsburgh, Pittsburgh, PA, 15260
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, 15260
- Center for Protein Conformational Diseases, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA,15260
| |
Collapse
|
10
|
Blando S, Raffaele I, Chiricosta L, Valeri A, Gugliandolo A, Silvestro S, Pollastro F, Mazzon E. Cannabidiol Promotes Neuronal Differentiation Using Akt and Erk Pathways Triggered by Cb1 Signaling. Molecules 2022; 27:molecules27175644. [PMID: 36080415 PMCID: PMC9457834 DOI: 10.3390/molecules27175644] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Recently, the scientific community has started to focus on the neurogenic potential of cannabinoids. The phytocompound cannabidiol (CBD) shows different mechanism of signaling on cannabinoid receptor 1 (CB1), depending on its concentration. In this study, we investigated if CBD may induce in vitro neuronal differentiation after treatment at 5 µM and 10 µM. For this purpose, we decided to use the spinal cord × neuroblastoma hybrid cell line (NSC-34) because of its proliferative and undifferentiated state. The messenger RNAs (mRNAs) expression profiles were tested using high-throughput sequencing technology and Western blot assay was used to determine the number of main proteins in different pathways. Interestingly, the treatment shows different genes associated with neurodifferentiation statistically significant, such as Rbfox3, Tubb3, Pax6 and Eno2. The CB1 signaling pathway is responsible for neuronal differentiation at 10 µM, as suggested by the presence of p-ERK and p-AKT, but not at 5 µM. A new correlation between CBD, neurodifferentiation and retinoic acid receptor-related orphan receptors (RORs) has been observed.
Collapse
Affiliation(s)
- Santino Blando
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
| | - Ivana Raffaele
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
| | - Luigi Chiricosta
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
| | - Andrea Valeri
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
| | - Agnese Gugliandolo
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
| | - Serena Silvestro
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
| | - Federica Pollastro
- Department of Pharmaceutical Sciences, University of Eastern Piedmont, Largo Donegani 2, 28100 Novara, Italy
| | - Emanuela Mazzon
- IRCCS Centro Neurolesi “Bonino-Pulejo”, Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy,
- Correspondence:
| |
Collapse
|
11
|
Masuda S, Tanaka S, Shiraki H, Sotomaru Y, Harada K, Hide I, Kiuchi Y, Sakai N. GPR3 expression in retinal ganglion cells contributes to neuron survival and accelerates axonal regeneration after optic nerve crush in mice. Neurobiol Dis 2022; 172:105811. [PMID: 35809764 DOI: 10.1016/j.nbd.2022.105811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/24/2022] [Accepted: 06/30/2022] [Indexed: 11/17/2022] Open
Abstract
Glaucoma is an optic neuropathy and is currently one of the most common diseases that leads to irreversible blindness. The axonal degeneration that occurs before retinal ganglion neuronal loss is suggested to be involved in the pathogenesis of glaucoma. G protein-coupled receptor 3 (GPR3) belongs to the class A rhodopsin-type GPCR family and is highly expressed in various neurons. GPR3 is unique in its ability to constitutively activate the Gαs protein without a ligand, which elevates the basal intracellular cAMP level. Our earlier reports suggested that GPR3 enhances both neurite outgrowth and neuronal survival. However, the potential role of GPR3 in axonal regeneration after neuronal injury has not been elucidated. Herein, we investigated retinal GPR3 expression and its possible involvement in axonal regeneration after retinal injury in mice. GPR3 was relatively highly expressed in retinal ganglion cells (RGCs). Surprisingly, RGCs in GPR3 knockout mice were vulnerable to neural death during aging without affecting high intraocular pressure (IOP) and under ischemic conditions. Primary cultured neurons from the retina showed that GPR3 expression was correlated with neurite outgrowth and neuronal survival. Evaluation of the effect of GPR3 on axonal regeneration using GPR3 knockout mice revealed that GPR3 in RGCs participates in axonal regeneration after optic nerve crush (ONC) under zymosan stimulation. In addition, regenerating axons were further stimulated when GPR3 was upregulated in RGCs, and the effect was further augmented when combined with zymosan treatment. These results suggest that GPR3 expression in RGCs helps maintain neuronal survival and accelerates axonal regeneration after ONC in mice.
Collapse
Affiliation(s)
- Shun Masuda
- Department of Molecular and Pharmacological Neuroscience, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; Department of Ophthalmology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Hiroko Shiraki
- Department of Molecular and Pharmacological Neuroscience, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Yusuke Sotomaru
- Natural Science Center for Basic Research and Development, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kana Harada
- Department of Molecular and Pharmacological Neuroscience, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| |
Collapse
|
12
|
Shiraki H, Tanaka S, Guo Y, Harada K, Hide I, Yasuda T, Sakai N. Potential role of inducible GPR3 expression under stimulated T cell conditions. J Pharmacol Sci 2022; 148:307-314. [PMID: 35177210 DOI: 10.1016/j.jphs.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/01/2022] [Accepted: 01/11/2022] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptor 3 (GPR3) constitutively activates Gαs proteins without any ligands and is predominantly expressed in neurons. Since the expression and physiological role of GPR3 in immune cells is still unknown, we examined the possible role of GPR3 in T lymphocytes. The expression of GPR3 was upregulated 2 h after phorbol 12-myristate 13-acetate (PMA)/ionomycin stimulation and was sustained in Jurkat cells, a human T lymphocyte cell line. In addition, the expression of nuclear receptor 4 group A member 2 (NR4A2) was highly modulated by GPR3 expression. Additionally, GPR3 expression was linked with the transcriptional promoter activity of NR4A in Jurkat cells. In mouse CD4+ T cells, transient GPR3 expression was induced immediately after the antigen receptor stimulation. However, the expression of NR4A2 was not modulated in CD4+ T cells from GPR3-knockout mice after stimulation, and the population of Treg cells in thymocytes and splenocytes was not affected by GPR3 knockout. By contrast, spontaneous effector activation in both CD4+ T cells and CD8+ T cells was observed in GPR3-knockout mice. In summary, GPR3 is immediately induced by T cell stimulation and play an important role in the suppression of effector T cell activation.
Collapse
Affiliation(s)
- Hiroko Shiraki
- Department of Molecular and Pharmacological Neuroscience, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Yun Guo
- Department of Immunology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kana Harada
- Department of Molecular and Pharmacological Neuroscience, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Tomoharu Yasuda
- Department of Immunology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| |
Collapse
|
13
|
Mantas I, Saarinen M, Xu ZQD, Svenningsson P. Update on GPCR-based targets for the development of novel antidepressants. Mol Psychiatry 2022; 27:534-558. [PMID: 33589739 PMCID: PMC8960420 DOI: 10.1038/s41380-021-01040-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 01/31/2023]
Abstract
Traditional antidepressants largely interfere with monoaminergic transport or degradation systems, taking several weeks to have their therapeutic actions. Moreover, a large proportion of depressed patients are resistant to these therapies. Several atypical antidepressants have been developed which interact with G protein coupled receptors (GPCRs) instead, as direct targeting of receptors may achieve more efficacious and faster antidepressant actions. The focus of this review is to provide an update on how distinct GPCRs mediate antidepressant actions and discuss recent insights into how GPCRs regulate the pathophysiology of Major Depressive Disorder (MDD). We also discuss the therapeutic potential of novel GPCR targets, which are appealing due to their ligand selectivity, expression pattern, or pharmacological profiles. Finally, we highlight recent advances in understanding GPCR pharmacology and structure, and how they may provide new avenues for drug development.
Collapse
Affiliation(s)
- Ioannis Mantas
- grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Marcus Saarinen
- grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Zhi-Qing David Xu
- grid.24696.3f0000 0004 0369 153XDepartment of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Per Svenningsson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
| |
Collapse
|
14
|
GPR3 accelerates neurite outgrowth and neuronal polarity formation via PI3 kinase-mediating signaling pathway in cultured primary neurons. Mol Cell Neurosci 2021; 118:103691. [PMID: 34871769 DOI: 10.1016/j.mcn.2021.103691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 11/24/2021] [Accepted: 11/28/2021] [Indexed: 11/23/2022] Open
Abstract
During neuronal development, immature neurons extend neurites and subsequently polarize to form an axon and dendrites. We have previously reported that G protein-coupled receptor 3 (GPR3) levels increase during neuronal development, and that GPR3 has functions in neurite outgrowth and neuronal differentiation in cerebellar granular neurons. Moreover, GPR3 is transported and concentrated at the tips of neurite, thereby contributing to the local activation of protein kinase A (PKA). However, the signaling pathways for GPR3-mediated neurite outgrowth and its subsequent effects on neuronal polarization have not yet been elucidated. We therefore analyzed the signaling pathways related to GPR3-mediated neurite outgrowth, and also focused on the possible roles of GPR3 in axon polarization. We demonstrated that, in cerebellar granular neurons, GPR3-mediated neurite outgrowth was mediated by multiple signaling pathways, including those of PKA, extracellular signal-regulated kinases (ERKs), and most strongly phosphatidylinositol 3-kinase (PI3K). In addition, the GPR3-mediated activation of neurite outgrowth was associated with G protein-coupled receptor kinase 2 (GRK2)-mediated signaling and phosphorylation of the C-terminus serine/threonine residues of GPR3, which affected downstream protein kinase B (Akt) signaling. We further demonstrated that GPR3 was transiently increased early in the development of rodent hippocampal neurons. It was subsequently concentrated at the tip of the longest neurite, and was thus associated with accelerated polarity formation in a PI3K-dependent manner in rat hippocampal neurons. In addition, GPR3 knockout in mouse hippocampal neurons led to delayed neuronal polarity formation, thereby affecting the dephosphorylation of collapsing response mediator protein 2 (CRMP2), which is downstream of the PI3K signaling pathway. Taken together, these findings suggest that the intrinsic expression of GPR3 in differentiated neurons constitutively activates PI3K-mediated signaling pathway predominantly, thus accelerating neurite outgrowth and further augmenting polarity formation in primary cultured neurons.
Collapse
|
15
|
Biringer RG. Endocannabinoid signaling pathways: beyond CB1R and CB2R. J Cell Commun Signal 2021; 15:335-360. [PMID: 33978927 PMCID: PMC8222499 DOI: 10.1007/s12079-021-00622-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/27/2021] [Indexed: 12/15/2022] Open
Abstract
The search for cannabinoid receptors other than CB1R and CB2R has been ongoing for over a decade. A number of orphan receptors have been proposed as potential cannabinoid receptors primarily based on phylogenic arguments and reactivity towards known endocannabinoids and phytocannabinoids. Seven putative cannabinoid receptors are described and discussed, and evidence for and against their inclusion in this category are presented.
Collapse
Affiliation(s)
- Roger Gregory Biringer
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, Bradenton, FL, 34211, USA.
| |
Collapse
|
16
|
Galiazzo G, De Silva M, Giancola F, Rinnovati R, Peli A, Chiocchetti R. Cellular distribution of cannabinoid-related receptors TRPV1, PPAR-gamma, GPR55 and GPR3 in the equine cervical dorsal root ganglia. Equine Vet J 2021; 54:788-798. [PMID: 34418142 PMCID: PMC9293124 DOI: 10.1111/evj.13499] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 06/18/2021] [Accepted: 08/19/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND The activation of cannabinoid and cannabinoid-related receptors by endogenous, plant-derived or synthetic cannabinoids may exert beneficial effects on pain perception. Of the cannabinoids contained in Cannabis sativa, cannabidiol (CBD) does not produce psychotropic effects and seems to represent a molecule having great therapeutic potential. Cannabidiol acts on a great number of cannabinoid and cannabinoid-related G-protein-coupled receptors and ionotropic receptors which have, to date, been understudied in veterinary medicine particularly in equine medicine. OBJECTIVES To localise the cellular distribution of four putative cannabinoid-related receptors in the equine cervical dorsal root ganglia (DRG). STUDY DESIGN A qualitative and quantitative immunohistochemical study. METHODS The cervical (C6-C8) DRG of six slaughtered horses were obtained from a local slaughterhouse. The tissues were fixed and processed for immunohistochemistry, and the resulting cryosections were used to investigate immunoreactivity for the following putative CBD receptors: Transient receptor potential vanilloid type 1 (TRPV1), nuclear peroxisome proliferator-activated receptor gamma (PPARγ), and G protein-coupled receptors 55 (GPR55) and 3 (GPR3). RESULTS Large percentages of neuronal cell bodies showed immunoreactivity for TRPV1 (80 ± 20%), PPARγ (100%), GPR55 (64 ± 15%) and GPR3 (63 ± 11%). The satellite glial cells (SGCs) were immunoreactive for TRPV1, PPARγ and GPR55. In addition, GPR55 immunoreactivity was expressed by DRG interneuronal macrophages. In addition, microglia cells were observed surrounding the neuron-SGC complex. MAIN LIMITATIONS The limited number of horses included in the study. CONCLUSIONS Cannabinoid-related receptors were distributed in the sensory neurons (TRPV1, PPARγ, GPR55 and GPR3), SGCs (TRPV1, PPARγ and GPR55), macrophages (GPR55) and other interneuronal cells (PPARγ and GPR55) of the equine DRG. Given the key role of DRG cellular elements and cannabinoid receptors in the pathophysiology of pain, the present findings provided an anatomical basis for additional studies aimed at exploring the therapeutic uses of non-psychotropic cannabinoid agonists for the management of pain in horses.
Collapse
Affiliation(s)
- Giorgia Galiazzo
- Department of Veterinary Medical Sciences (UNI EN ISO 9001:2008)University of BolognaBolognaItaly
| | - Margherita De Silva
- Department of Veterinary Medical Sciences (UNI EN ISO 9001:2008)University of BolognaBolognaItaly
| | - Fiorella Giancola
- Department of Veterinary Medical Sciences (UNI EN ISO 9001:2008)University of BolognaBolognaItaly
| | - Riccardo Rinnovati
- Department of Veterinary Medical Sciences (UNI EN ISO 9001:2008)University of BolognaBolognaItaly
| | - Angelo Peli
- Department of Veterinary Medical Sciences (UNI EN ISO 9001:2008)University of BolognaBolognaItaly
| | - Roberto Chiocchetti
- Department of Veterinary Medical Sciences (UNI EN ISO 9001:2008)University of BolognaBolognaItaly
| |
Collapse
|
17
|
Iorio C, Rourke JL, Wells L, Sakamaki JI, Moon E, Hu Q, Kin T, Screaton RA. Silencing the G-protein coupled receptor 3-salt inducible kinase 2 pathway promotes human β cell proliferation. Commun Biol 2021; 4:907. [PMID: 34302056 PMCID: PMC8302759 DOI: 10.1038/s42003-021-02433-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 07/08/2021] [Indexed: 02/07/2023] Open
Abstract
Loss of pancreatic β cells is the hallmark of type 1 diabetes, for which provision of insulin is the standard of care. While regenerative and stem cell therapies hold the promise of generating single-source or host-matched tissue to obviate immune-mediated complications, these will still require surgical intervention and immunosuppression. Here we report the development of a high-throughput RNAi screening approach to identify upstream pathways that regulate adult human β cell quiescence and demonstrate in a screen of the GPCRome that silencing G-protein coupled receptor 3 (GPR3) leads to human pancreatic β cell proliferation. Loss of GPR3 leads to activation of Salt Inducible Kinase 2 (SIK2), which is necessary and sufficient to drive cell cycle entry, increase β cell mass, and enhance insulin secretion in mice. Taken together, our data show that targeting the GPR3-SIK2 pathway is a potential strategy to stimulate the regeneration of β cells.
Collapse
Affiliation(s)
| | - Jillian L Rourke
- Sunnybrook Research Institute, Toronto, Canada
- Mount Allison University, Sackville, NB, Canada
| | - Lisa Wells
- Sunnybrook Research Institute, Toronto, Canada
| | - Jun-Ichi Sakamaki
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan
| | - Emily Moon
- Sunnybrook Research Institute, Toronto, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Queenie Hu
- Sunnybrook Research Institute, Toronto, Canada
| | - Tatsuya Kin
- Clinical Islet Laboratory, University of Alberta Hospital, Edmonton, Canada
| | - Robert A Screaton
- Sunnybrook Research Institute, Toronto, Canada.
- Department of Biochemistry, University of Toronto, Toronto, Canada.
| |
Collapse
|
18
|
Characterization of Four Orphan Receptors (GPR3, GPR6, GPR12 and GPR12L) in Chickens and Ducks and Regulation of GPR12 Expression in Ovarian Granulosa Cells by Progesterone. Genes (Basel) 2021; 12:genes12040489. [PMID: 33801713 PMCID: PMC8065388 DOI: 10.3390/genes12040489] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 11/29/2022] Open
Abstract
The three structurally related orphan G protein-coupled receptors, GRP3, GPR6, and GPR12, are reported to be constitutively active and likely involved in the regulation of many physiological/pathological processes, such as neuronal outgrowth and oocyte meiotic arrest in mammals. However, the information regarding these orphan receptors in nonmammalian vertebrates is extremely limited. Here, we reported the structure, constitutive activity, and tissue expression of these receptors in two representative avian models: chickens and ducks. The cloned duck GPR3 and duck/chicken GPR6 and GPR12 are intron-less and encode receptors that show high amino acid (a.a.) sequence identities (66–88%) with their respective mammalian orthologs. Interestingly, a novel GPR12-like receptor (named GPR12L) sharing 66% a.a. identity to that in vertebrates was reported in the present study. Using dual-luciferase reporter assay and Western blot, we demonstrated that GPR3, GPR6, GPR12, and GPR12L are constitutively active and capable of stimulating the cAMP/PKA signaling pathway without ligand stimulation in birds (and zebrafish), indicating their conserved signaling property across vertebrates. RNA-seq data/qRT-PCR assays revealed that GPR6 and GPR12L expression is mainly restricted to the chicken brain, while GPR12 is highly expressed in chicken ovarian granulosa cells (GCs) and oocytes of 6 mm growing follicles and its expression in cultured GCs is upregulated by progesterone. Taken together, our data reveal the structure, function, and expression of GPR3, GPR6, GPR12, and GPR12L in birds, thus providing the first piece of evidence that GPR12 expression is upregulated by gonadal steroid (i.e., progesterone) in vertebrates.
Collapse
|
19
|
Takahashi T, Yoshida T, Harada K, Miyagi T, Hashimoto K, Hide I, Tanaka S, Irifune M, Sakai N. Component of nicotine-induced intracellular calcium elevation mediated through α3- and α5-containing nicotinic acetylcholine receptors are regulated by cyclic AMP in SH-SY 5Y cells. PLoS One 2020; 15:e0242349. [PMID: 33253222 PMCID: PMC7703979 DOI: 10.1371/journal.pone.0242349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/01/2020] [Indexed: 12/03/2022] Open
Abstract
The pathway from the medial habenular nucleus to the interpeduncular nucleus, in which nicotinic acetylcholine receptor (nAChR) including the α3 and α5 subunits (α3 * and α5 * nAChRs) are expressed, is implicated in nicotine dependence. We investigated whether α3 * and α5 * nAChRs are regulated by cAMP using SH-SY5Y cells to clarify the significance of these receptors in nicotine dependence. We analyzed the nicotine-induced elevation of intracellular Ca2+ ([Ca2+]i). Nicotine induces a concentration-dependent increase in [Ca2+]i. The elimination of Ca2+ from extracellular fluid or intracellular stores demonstrated that the nicotine-induced [Ca2+]i elevation was due to extracellular influx and intracellular mobilization. The effects of tubocurarine on nicotine-induced [Ca2+]i elevation and current suggest that intracellular mobilization is caused by plasma membrane-permeating nicotine. The inhibition of α3 *, α5 *, α7 nAChR and voltage-gated Ca2+ channels by using siRNAs and selective antagonists revealed the involvement of these nAChR subunits and channels in nicotine-induced [Ca2+]i elevation. To distinguish and characterize the α3 * and α5 * nAChR-mediated Ca2+ influx, we measured the [Ca2+]i elevation induced by nonmembrane-permeating acetylcholine when muscarinic receptors, α7nAChR and Ca2+ channels were blocked. Under this condition, the [Ca2+]i elevation was significantly inhibited with a 48-h treatment of dibutyryl cAMP, which was accompanied by the downregulation of α3 and β4 mRNA. These findings suggest that α3 * and α5 * nAChR-mediated Ca2+ influx is possibly regulated by cAMP at the transcriptional level.
Collapse
Affiliation(s)
- Tamayo Takahashi
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Takayuki Yoshida
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kana Harada
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tatsuhiko Miyagi
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masahiro Irifune
- Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- * E-mail:
| |
Collapse
|
20
|
Ikawa F, Tanaka S, Harada K, Hide I, Maruyama H, Sakai N. Detailed neuronal distribution of GPR3 and its co-expression with EF-hand calcium-binding proteins in the mouse central nervous system. Brain Res 2020; 1750:147166. [PMID: 33075309 DOI: 10.1016/j.brainres.2020.147166] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/11/2022]
Abstract
The G-protein coupled receptor 3 (GPR3), a member of the class A rhodopsin-type GPR family, constitutively activates Gαs proteins without any ligands. Although there have been several reports concerning the functions of GPR3 in neurons, the physiological roles of GPR3 have not been fully elucidated. To address this issue, we analyzed GPR3 distribution in detail using fluorescence-based X-gal staining in heterozygous GPR3 knockout/LacZ knock-in mice, and further investigated the types of GPR3-expressing neurons using fluorescent double labeling with various EF-hand Ca2+-binding proteins. In addition to the previously reported GPR3-expressing areas, we identified GPR3 expression in the basal ganglia and in many nuclei of the cranial nerves, in regions related to olfactory, auditory, emotional, and motor functions. In addition, GPR3 was not only observed in excitatory neurons in layer V of the cerebral cortex, the CA2 region of the hippocampus, and the lateral nucleus of the thalamus, but also in γ-aminobutyric acid (GABA)-ergic interneurons in the cortex, hippocampus, thalamus, striatum, and cerebellum. GPR3 was frequently co-expressed with neuronal Ca2+-binding protein 2 (NECAB2) in neurons in various regions of the central nervous system, especially in the hippocampal CA2, medial habenular nucleus, lateral thalamic nucleus, dorsolateral striatum, brainstem, and spinal cord anterior horn. Furthermore, GPR3 also co-localized with NECAB2 at the tips of neurites in differentiated PC12 cells. These results suggest that GPR3 and NECAB2 are highly co-expressed in specific neurons, and that GPR3 may modulate Ca2+ signaling by interacting with NECAB2 in specific areas of the central nervous system.
Collapse
Affiliation(s)
- Fumiaki Ikawa
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Department of Neurology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
| | - Kana Harada
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hirofumi Maruyama
- Department of Neurology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| |
Collapse
|
21
|
Watkins LR, Orlandi C. Orphan G Protein Coupled Receptors in Affective Disorders. Genes (Basel) 2020; 11:E694. [PMID: 32599826 PMCID: PMC7349732 DOI: 10.3390/genes11060694] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 12/12/2022] Open
Abstract
G protein coupled receptors (GPCRs) are the main mediators of signal transduction in the central nervous system. Therefore, it is not surprising that many GPCRs have long been investigated for their role in the development of anxiety and mood disorders, as well as in the mechanism of action of antidepressant therapies. Importantly, the endogenous ligands for a large group of GPCRs have not yet been identified and are therefore known as orphan GPCRs (oGPCRs). Nonetheless, growing evidence from animal studies, together with genome wide association studies (GWAS) and post-mortem transcriptomic analysis in patients, pointed at many oGPCRs as potential pharmacological targets. Among these discoveries, we summarize in this review how emotional behaviors are modulated by the following oGPCRs: ADGRB2 (BAI2), ADGRG1 (GPR56), GPR3, GPR26, GPR37, GPR50, GPR52, GPR61, GPR62, GPR88, GPR135, GPR158, and GPRC5B.
Collapse
Affiliation(s)
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA;
| |
Collapse
|
22
|
Laun AS, Shrader SH, Brown KJ, Song ZH. GPR3, GPR6, and GPR12 as novel molecular targets: their biological functions and interaction with cannabidiol. Acta Pharmacol Sin 2019; 40:300-308. [PMID: 29941868 PMCID: PMC6460361 DOI: 10.1038/s41401-018-0031-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/17/2018] [Indexed: 01/08/2023] Open
Abstract
The G protein-coupled receptors 3, 6, and 12 (GPR3, GPR6, and GPR12) comprise a family of closely related orphan receptors with no confirmed endogenous ligands. These receptors are constitutively active and capable of signaling through G protein-mediated and non-G protein-mediated mechanisms. These orphan receptors have previously been reported to play important roles in many normal physiological functions and to be involved in a variety of pathological conditions. Although they are orphans, GPR3, GPR6, and GPR12 are phylogenetically most closely related to the cannabinoid receptors. Using β-arrestin2 recruitment and cAMP accumulation assays, we recently found that the nonpsychoactive phytocannabinoid cannabidiol (CBD) is an inverse agonist for GPR3, GPR6, and GPR12. This discovery highlights these orphan receptors as potential new molecular targets for CBD, provides novel mechanisms of action, and suggests new therapeutic uses of CBD for illnesses such as Alzheimer's disease, Parkinson's disease, cancer, and infertility. Furthermore, identification of CBD as a new inverse agonist for GPR3, GPR6, and GPR12 provides the initial chemical scaffolds upon which potent and efficacious agents acting on these receptors can be developed, with the goal of developing chemical tools for studying these orphan receptors and ultimately new therapeutic agents.
Collapse
Affiliation(s)
- Alyssa S Laun
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Sarah H Shrader
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Kevin J Brown
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Zhao-Hui Song
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA.
| |
Collapse
|
23
|
Morales P, Isawi I, Reggio PH. Towards a better understanding of the cannabinoid-related orphan receptors GPR3, GPR6, and GPR12. Drug Metab Rev 2018; 50:74-93. [PMID: 29390908 DOI: 10.1080/03602532.2018.1428616] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
GPR3, GPR6, and GPR12 are three orphan receptors that belong to the Class A family of G-protein-coupled receptors (GPCRs). These GPCRs share over 60% of sequence similarity among them. Because of their close phylogenetic relationship, GPR3, GPR6, and GPR12 share a high percentage of homology with other lipid receptors such as the lysophospholipid and the cannabinoid receptors. On the basis of sequence similarities at key structural motifs, these orphan receptors have been related to the cannabinoid family. However, further experimental data are required to confirm this association. GPR3, GPR6, and GPR12 are predominantly expressed in mammalian brain. Their high constitutive activation of adenylyl cyclase triggers increases in cAMP levels similar in amplitude to fully activated GPCRs. This feature defines their physiological role under certain pathological conditions. In this review, we aim to summarize the knowledge attained so far on the understanding of these receptors. Expression patterns, pharmacology, physiopathological relevance, and molecules targeting GPR3, GPR6, and GPR12 will be analyzed herein. Interestingly, certain cannabinoid ligands have been reported to modulate these orphan receptors. The current debate about sphingolipids as putative endogenous ligands will also be addressed. A special focus will be on their potential role in the brain, particularly under neurological conditions such as Parkinson or Alzheimer's disease. Reported physiological roles outside the central nervous system will also be covered. This critical overview may contribute to a further comprehension of the physiopathological role of these orphan GPCRs, hopefully attracting more research towards a future therapeutic exploitation of these promising targets.
Collapse
Affiliation(s)
- Paula Morales
- a Department of Chemistry and Biochemistry , University of North Carolina at Greensboro , Greensboro , NC , USA
| | - Israa Isawi
- a Department of Chemistry and Biochemistry , University of North Carolina at Greensboro , Greensboro , NC , USA
| | - Patricia H Reggio
- a Department of Chemistry and Biochemistry , University of North Carolina at Greensboro , Greensboro , NC , USA
| |
Collapse
|
24
|
Tanaka S. [Signaling and functions of G-protein-coupled receptor 3 in cerebellar granular neurons]. Nihon Yakurigaku Zasshi 2018; 152:78-83. [PMID: 30101864 DOI: 10.1254/fpj.152.78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
G-protein-coupled receptor 3 (GPR3) is a member of the class A rhodopsin-type GPCR family and is highly expressed in various neurons. A unique feature of GPR3 is its ability to constitutively activate the Gαs protein without the addition of ligands, which results in the elevation of the basal level of intracellular cAMP. During the development of the cerebellum, GPR3 expression is upregulated in cerebellar granular neurons (CGNs) and maintained thereafter. In our previous studies, we showed that the intrinsic expression of GPR3 in CGNs is highly associated with neurite outgrowth, neurite differentiation, and neuronal survival. Recently, we have focused on the possible signaling pathways associated with GPR3-mediated neurite outgrowth in CGNs. Interestingly, GPR3-mediated neurite outgrowth is mediated by not only PKA-dependent signaling pathways but also PI3K-mediated signaling pathways. Moreover, the Gβγ-mediated signaling pathway is involved in GPR3-mediated neurite outgrowth. These results suggested that neural expression of GPR3 stimulates multiple downstream signaling pathways, contributing to the maintenance of homeostasis in neurons. Further precise analyses of constitutively active GPCRs may help in unveiling novel neuronal functions.
Collapse
Affiliation(s)
- Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Graduate school of Biomedical & Health Sciences, Hiroshima University
| |
Collapse
|
25
|
Morales P, Reggio PH. An Update on Non-CB 1, Non-CB 2 Cannabinoid Related G-Protein-Coupled Receptors. Cannabis Cannabinoid Res 2017; 2:265-273. [PMID: 29098189 PMCID: PMC5665501 DOI: 10.1089/can.2017.0036] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The endocannabinoid system (ECS) has been shown to be of great importance in the regulation of numerous physiological and pathological processes. To date, two Class A G-protein-coupled receptors (GPCRs) have been discovered and validated as the main therapeutic targets of this system: the cannabinoid receptor type 1 (CB1), which is the most abundant neuromodulatory receptor in the brain, and the cannabinoid receptor type 2 (CB2), predominantly found in the immune system among other organs and tissues. Endogenous cannabinoid receptor ligands (endocannabinoids) and the enzymes involved in their synthesis, cell uptake, and degradation have also been identified as part of the ECS. However, its complex pharmacology suggests that other GPCRs may also play physiologically relevant roles in this therapeutically promising system. In the last years, GPCRs such as GPR18 and GPR55 have emerged as possible missing members of the cannabinoid family. This categorization still stimulates strong debate due to the lack of pharmacological tools to validate it. Because of their close phylogenetic relationship, the Class A orphan GPCRs, GPR3, GPR6, and GPR12, have also been associated with the cannabinoids. Moreover, certain endo-, phyto-, and synthetic cannabinoid ligands have displayed activity at other well-established GPCRs, including the opioid, adenosine, serotonin, and dopamine receptor families. In addition, the cannabinoid receptors have also been shown to form dimers with other GPCRs triggering cross-talk signaling under specific conditions. In this mini review, we aim to provide insight into the non-CB1, non-CB2 cannabinoid-related GPCRs that have been reported thus far. We consider the physiological relevance of these molecular targets in modulating the ECS.
Collapse
Affiliation(s)
- Paula Morales
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, North Carolina
| | - Patricia H. Reggio
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, North Carolina
| |
Collapse
|
26
|
Abstract
The Reggio group has constructed computer models of the inactive and G-protein-activated states of the cannabinoid CB1 and CB2 receptors, as well as, several orphan receptors that recognize a subset of cannabinoid compounds, including GPR55 and GPR18. These models have been used to design ligands, mutations, and covalent labeling studies. The resultant second-generation models have been used to design ligands with improved affinity, efficacy, and subtype selectivity. Herein, we provide a guide for the development of GPCR models using the most recent orphan receptor studied in our lab, GPR3. GPR3 is an orphan receptor that belongs to the Class A family of G-protein-coupled receptors. It shares high sequence similarity with GPR6, GPR12, the lysophospholipid receptors, and the cannabinoid receptors. GPR3 is predominantly expressed in mammalian brain and oocytes and it is known as a Gαs-coupled receptor activated constitutively in cells. GPR3 represents a possible target for the treatment of different pathological conditions such as Alzheimer's disease, oocyte maturation, or neuropathic pain. However, the lack of potent and selective GPR3 ligands is delaying the exploitation of this promising therapeutic target. In this context, we aim to develop a homology model that helps us to elucidate the structural determinants governing ligand-receptor interactions at GPR3. In this chapter, we detail the methods and rationale behind the construction of the GPR3 active-and inactive-state models. These homology models will enable the rational design of novel ligands, which may serve as research tools for further understanding of the biological role of GPR3.
Collapse
Affiliation(s)
- Paula Morales
- University of North Carolina at Greensboro, Greensboro, NC, United States.
| | - Dow P Hurst
- University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Patricia H Reggio
- University of North Carolina at Greensboro, Greensboro, NC, United States
| |
Collapse
|
27
|
Khan MZ, He L. Neuro-psychopharmacological perspective of Orphan receptors of Rhodopsin (class A) family of G protein-coupled receptors. Psychopharmacology (Berl) 2017; 234:1181-1207. [PMID: 28289782 DOI: 10.1007/s00213-017-4586-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/27/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND In the central nervous system (CNS), G protein-coupled receptors (GPCRs) are the most fruitful targets for neuropsychopharmacological drug development. Rhodopsin (class A) is the most studied class of GPCR and includes orphan receptors for which the endogenous ligand is not known or is unclear. Characterization of orphan GPCRs has proven to be challenging, and the production pace of GPCR-based drugs has been incredibly slow. OBJECTIVE Determination of the functions of these receptors may provide unexpected insight into physiological and neuropathological processes. Advances in various methods and techniques to investigate orphan receptors including in situ hybridization and knockdown/knockout (KD/KO) showed extensive expression of these receptors in the mammalian brain and unmasked their physiological and neuropathological roles. Due to these rapid progress and development, orphan GPCRs are rising as a new and promising class of drug targets for neurodegenerative diseases and psychiatric disorders. CONCLUSION This review presents a neuropsychopharmacological perspective of 26 orphan receptors of rhodopsin (class A) family, namely GPR3, GPR6, GPR12, GPR17, GPR26, GPR35, GPR39, GPR48, GPR49, GPR50, GPR52, GPR55, GPR61, GPR62, GPR63, GPR68, GPR75, GPR78, GPR83, GPR84, GPR85, GPR88, GPR153, GPR162, GPR171, and TAAR6. We discussed the expression of these receptors in mammalian brain and their physiological roles. Furthermore, we have briefly highlighted their roles in neurodegenerative diseases and psychiatric disorders including Alzheimer's disease, Parkinson's disease, neuroinflammation, inflammatory pain, bipolar and schizophrenic disorders, epilepsy, anxiety, and depression.
Collapse
Affiliation(s)
- Muhammad Zahid Khan
- Department of Pharmacology, China Pharmaceutical University, No. 24 Tong Jia Xiang, Nanjing, Jiangsu Province, 210009, China.
| | - Ling He
- Department of Pharmacology, China Pharmaceutical University, No. 24 Tong Jia Xiang, Nanjing, Jiangsu Province, 210009, China
| |
Collapse
|
28
|
Su D, Wang M, Ye C, Fang J, Duan Y, Zhang Z, Hua Q, Shi C, Zhang L, Zhang R, Xie X. One-step generation of mice carrying a conditional allele together with an HA-tag insertion for the delta opioid receptor. Sci Rep 2017; 7:44476. [PMID: 28300205 PMCID: PMC5353682 DOI: 10.1038/srep44476] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 02/09/2017] [Indexed: 12/11/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are important modulators of many physiological functions and excellent drug targets for many diseases. However, to study the functions of endogenous GPCRs is still a challenging task, partially due to the low expression level of GPCRs and the lack of highly potent and selective GPCR antibodies. Overexpression or knock-in of tagged GPCRs, or knockout of specific GPCRs in mice, are common strategies used to study the in vivo functions of these receptors. However, generating separate mice carrying tagged GPCRs or conditional alleles for GPCRs is labor intensive, and requires additional breeding costs. Here we report the generation of mice carrying an HA-tagged DOR (delta opioid receptor) flanked by LoxP sequences at the endogenous DOR locus using a single recombination step, aided by the TALEN system. These animals can be used directly to study the expression, localization, protein-protein interaction and signal transduction of endogenous DOR using anti-HA antibodies. By crossing with mice expressing tissue-specific Cre, these mice can also generate offspring with DOR knockout within specific tissues. These mice are powerful tools to study the in vivo functions of DOR. Furthermore, the gene modification strategy could also be used to study the functions of many other GPCRs.
Collapse
Affiliation(s)
- Dongru Su
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Min Wang
- CAS Key Laboratory of Receptor Research, National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Chenli Ye
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jiahui Fang
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Yanhui Duan
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Zhenghong Zhang
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Qiuhong Hua
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Changjie Shi
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Lihong Zhang
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Ru Zhang
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Xin Xie
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.,CAS Key Laboratory of Receptor Research, National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| |
Collapse
|
29
|
Oeckl P, Ferger B. Increased susceptibility of G-protein coupled receptor 6 deficient mice to MPTP neurotoxicity. Neuroscience 2016; 337:218-223. [PMID: 27651149 DOI: 10.1016/j.neuroscience.2016.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 09/02/2016] [Accepted: 09/12/2016] [Indexed: 11/19/2022]
Abstract
The G-protein coupled receptor 6 (GPR6) is a constitutive active orphan GPCR which is predominantly expressed in striatopallidal neurons. GPR6 deficiency in mice may alter the susceptibility of the nigrostriatal dopaminergic system relevant for Parkinson's disease (PD). Here, we investigated the effect of GPR6 deficiency in mice on neurotoxicity induced by the dopaminergic neurotoxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). GPR6-/-- and control mice were treated with MPTP (4×12.5mg/kg, i.p., 2h intervals) and analyzed after seven days. Striatal dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and 4-hydroxy-3-methoxyphenylacetic acid (HVA) concentrations were measured by HPLC. The number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra pars compacta (SNpc) was analyzed by immunohistochemistry. In a separate group of mice, MPP+ (500μM for 20min) was administered via an intrastriatal microdialysis probe to measure the MPP+-induced DA release. MPTP produced a significant reduction in striatal DA, DOPAC, HVA and an increase in dopamine turnover in control and GPR6-/--mice. The MPTP-induced DA and HVA depletion was significantly more pronounced in GPR6-/--mice. Consistently, the MPTP-induced reduction of TH-positive neurons in the SPpc was significantly higher in GPR6-/--mice. Furthermore, the MPP+-induced dopamine release was significantly higher in GPR6-/--mice. In conclusion, we showed that MPTP induces an enhanced dopaminergic neurodegeneration in GPR6-/--mice indicated by alterations at the striatal and nigral level. We propose that GPR6 signaling is involved in the cascade of neurodegenerative events of the parkinsonian neurotoxin MPTP and suggest that pharmacological modulation of GPR6 might represent an entry point to further investigate GPR6 in PD.
Collapse
Affiliation(s)
- Patrick Oeckl
- CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, D-88397 Biberach an der Riss, Germany
| | - Boris Ferger
- CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, D-88397 Biberach an der Riss, Germany.
| |
Collapse
|
30
|
GDF-15 enhances intracellular Ca2+ by increasing Cav1.3 expression in rat cerebellar granule neurons. Biochem J 2016; 473:1895-904. [PMID: 27114559 PMCID: PMC4925162 DOI: 10.1042/bcj20160362] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 04/25/2016] [Indexed: 12/17/2022]
Abstract
GDF-15 (growth/differentiation factor 15) is a novel member of the TGF (transforming growth factor)-β superfamily that has critical roles in the central and peripheral nervous systems. We reported previously that GDF-15 increased delayed rectifier outward K+ currents and Kv2.1 α subunit expression through TβRII (TGF-β receptor II) to activate Src kinase and Akt/mTOR (mammalian target of rapamycin) signalling in rat CGNs (cerebellar granule neurons). In the present study, we found that treatment of CGNs with GDF-15 for 24 h increased the intracellular Ca2+ concentration ([Ca2+]i) in response to membrane depolarization, as determined by Ca2+ imaging. Whole-cell current recordings indicated that GDF-15 increased the inward Ca2+ current (ICa) without altering steady-state activation of Ca2+ channels. Treatment with nifedipine, an inhibitor of L-type Ca2+ channels, abrogated GDF-15-induced increases in [Ca2+]i and ICa. The GDF-15-induced increase in ICa was mediated via up-regulation of the Cav1.3 α subunit, which was attenuated by inhibiting Akt/mTOR and ERK (extracellular-signal-regulated kinase) pathways and by pharmacological inhibition of Src-mediated TβRII phosphorylation. Given that Cav1.3 is not only a channel for Ca2+ influx, but also a transcriptional regulator, our data confirm that GDF-15 induces protein expression via TβRII and activation of a non-Smad pathway, and provide novel insight into the mechanism of GDF-15 function in neurons.
Collapse
|
31
|
Miyagi T, Tanaka S, Hide I, Shirafuji T, Sakai N. The Subcellular Dynamics of the Gs-Linked Receptor GPR3 Contribute to the Local Activation of PKA in Cerebellar Granular Neurons. PLoS One 2016; 11:e0147466. [PMID: 26800526 PMCID: PMC4723318 DOI: 10.1371/journal.pone.0147466] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/03/2016] [Indexed: 12/12/2022] Open
Abstract
G-protein-coupled receptor (GPR) 3 is a member of the GPR family that constitutively activates adenylate cyclase. We have reported that the expression of GPR3 in cerebellar granular neurons (CGNs) contributes to neurite outgrowth and modulates neuronal proliferation and survival. To further identify its role, we have analyzed the precise distribution and local functions of GPR3 in neurons. The fluorescently tagged GPR3 protein was distributed in the plasma membrane, the Golgi body, and the endosomes. In addition, we have revealed that the plasma membrane expression of GPR3 functionally up-regulated the levels of PKA, as measured by a PKA FRET indicator. Next, we asked if the PKA activity was modulated by the expression of GPR3 in CGNs. PKA activity was highly modulated at the neurite tips compared to the soma. In addition, the PKA activity at the neurite tips was up-regulated when GPR3 was transfected into the cells. However, local PKA activity was decreased when endogenous GPR3 was suppressed by a GPR3 siRNA. Finally, we determined the local dynamics of GPR3 in CGNs using time-lapse analysis. Surprisingly, the fluorescent GPR3 puncta were transported along the neurite in both directions over time. In addition, the anterograde movements of the GPR3 puncta in the neurite were significantly inhibited by actin or microtubule polymerization inhibitors and were also disturbed by the Myosin II inhibitor blebbistatin. Moreover, the PKA activity at the tips of the neurites was decreased when blebbistatin was administered. These results suggested that GPR3 was transported along the neurite and contributed to the local activation of PKA in CGN development. The local dynamics of GPR3 in CGNs may affect local neuronal functions, including neuronal differentiation and maturation.
Collapse
Affiliation(s)
- Tatsuhiro Miyagi
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Toshihiko Shirafuji
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| |
Collapse
|
32
|
Ahmad R, Wojciech S, Jockers R. Hunting for the function of orphan GPCRs - beyond the search for the endogenous ligand. Br J Pharmacol 2014; 172:3212-28. [PMID: 25231237 DOI: 10.1111/bph.12942] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/04/2014] [Accepted: 09/09/2014] [Indexed: 12/13/2022] Open
Abstract
Seven transmembrane-spanning proteins (7TM), also called GPCRs, are among the most versatile and evolutionary successful protein families. Out of the 400 non-odourant members identified in the human genome, approximately 100 remain orphans that have not been matched with an endogenous ligand. Apart from the classical deorphanization strategies, several alternative strategies provided recent new insights into the function of these proteins, which hold promise for high therapeutic potential. These alternative strategies consist of the phenotypical characterization of organisms silenced or overexpressing orphan 7TM proteins, the search for constitutive receptor activity and formation of protein complexes including 7TM proteins as well as the development of synthetic, surrogate ligands. Taken together, a variety of ligand-independent functions can be attributed to orphan 7TM proteins that range from constitutive activity to complex formation with other proteins and include 'true' orphans for which no ligand exist and 'conditional' orphans that behave like orphans in the absence of ligand and as non-orphans in the presence of ligand.
Collapse
Affiliation(s)
- Raise Ahmad
- Institut Cochin, INSERM, Paris, France.,CNRS UMR 8104, Paris, France.,Paris Descartes University, Paris, France
| | - Stefanie Wojciech
- Institut Cochin, INSERM, Paris, France.,CNRS UMR 8104, Paris, France.,Paris Descartes University, Paris, France
| | - Ralf Jockers
- Institut Cochin, INSERM, Paris, France.,CNRS UMR 8104, Paris, France.,Paris Descartes University, Paris, France
| |
Collapse
|