1
|
Allen BG, Merlen C, Branco AF, Pétrin D, Hébert TE. Understanding the impact of nuclear-localized GPCRs on cellular signalling. Cell Signal 2024; 123:111358. [PMID: 39181220 DOI: 10.1016/j.cellsig.2024.111358] [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: 07/24/2024] [Revised: 08/14/2024] [Accepted: 08/20/2024] [Indexed: 08/27/2024]
Abstract
G protein-coupled receptors (GPCRs) have historically been associated with signalling events driven from the plasma membrane. More recently, signalling from endosomes has been recognized as a feature of internalizing receptors. However, there was little consideration given to the notion that GPCRs can be targeted to distinct subcellular locations that did not involve an initial trafficking to the cell surface. Here, we focus on the evidence for and the potential impact of GPCR signalling specifically initiated from the nuclear membrane. We also discuss the possibilities for selectively targeting this and other internal pools of receptors as novel venues for drug discovery.
Collapse
Affiliation(s)
- Bruce G Allen
- Montreal Heart Institute, Montréal, Québec H1T 1C8, Canada; Departments of Biochemistry and Molecular Medicine, Medicine, Pharmacology and Physiology, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | | | - Ana F Branco
- Montreal Heart Institute, Montréal, Québec H1T 1C8, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
| |
Collapse
|
2
|
Zhang X, Si Y, Zhang L, Wen X, Yang C, Wang L, Song L. Involvement of metabotropic glutamate receptors in regulation of immune response in the Pacific oyster Crassostrea gigas. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109709. [PMID: 38901684 DOI: 10.1016/j.fsi.2024.109709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 05/16/2024] [Accepted: 06/17/2024] [Indexed: 06/22/2024]
Abstract
Metabotropic glutamate receptors (mGluRs) play a pivotal role in the neuroendocrine-immune regulation. In this study, eight mGluRs were identified in the Pacific Oyster Crassostrea gigas, which were classified into three subfamilies based on genetic similarity. All CgmGluRs harbor variable numbers of PBP1 domains at the N-terminus. The sequence and structural features of CgmGluRs are highly similar to mGluRs in other species. A uniformly upregulated expression of CgmGluRs was observed during D-shaped larval stage compared to early D-shaped larval stage. The transcripts of CgmGluRs were detectable in various tissues of oyster. Different CgmGluR exhibited diverse expression patterns response against different PAMP stimulations, among which CgmGluR5 was significantly downregulated under these stimulations, reflecting its sensitivity and broad-spectrum responsiveness to microbes. Following LPS stimulation, the mRNA expression of CgmGluR5 and CgCALM1 in haemocytes was suppressed within 6 h and returned to normal levels by 12 h. Inhibition of CgmGluR5 activity resulted in a significant reduction in CgCALM1 expression after 12 h. Further KEGG enrichment analysis suggested that CgmGluR5 might modulate calcium ion homeostasis and metabolic pathways by regulating CgCALM1. This research delivers the systematic analysis of mGluR in the Pacific Oyster, offering insights into evolutionary characteristics and immunoregulatory function of mGluR in mollusks.
Collapse
Affiliation(s)
- Xueshu Zhang
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Yiran Si
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Linfang Zhang
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Xue Wen
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Chuanyan Yang
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China.
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China; Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| |
Collapse
|
3
|
Jong YJI, Izumi Y, Harmon SK, Zorumski CF, ÓMalley KL. Striatal mGlu 5-mediated synaptic plasticity is independently regulated by location-specific receptor pools and divergent signaling pathways. J Biol Chem 2023; 299:104949. [PMID: 37354970 PMCID: PMC10388212 DOI: 10.1016/j.jbc.2023.104949] [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: 02/13/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/26/2023] Open
Abstract
Metabotropic glutamate receptor 5 (mGlu5) is widely expressed throughout the central nervous system and is involved in neuronal function, synaptic transmission, and a number of neuropsychiatric disorders such as depression, anxiety, and autism. Recent work from this lab showed that mGlu5 is one of a growing number of G protein-coupled receptors that can signal from intracellular membranes where it drives unique signaling pathways, including upregulation of extracellular signal-regulated kinase (ERK1/2), ETS transcription factor Elk-1, and activity-regulated cytoskeleton-associated protein (Arc). To determine the roles of cell surface mGlu5 as well as the intracellular receptor in a well-known mGlu5 synaptic plasticity model such as long-term depression, we used pharmacological isolation and genetic and physiological approaches to analyze spatially restricted pools of mGlu5 in striatal cultures and slice preparations. Here we show that both intracellular and cell surface receptors activate the phosphatidylinositol-3-kinase-protein kinase B-mammalian target of rapamycin (PI3K/AKT/mTOR) pathway, whereas only intracellular mGlu5 activates protein phosphatase 2 and leads to fragile X mental retardation protein degradation and de novo protein synthesis followed by a protein synthesis-dependent increase in Arc and post-synaptic density protein 95. However, both cell surface and intracellular mGlu5 activation lead to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor GluA2 internalization and chemically induced long-term depression albeit via different signaling mechanisms. These data underscore the importance of intracellular mGlu5 in the cascade of events associated with sustained synaptic transmission in the striatum.
Collapse
Affiliation(s)
- Yuh-Jiin I Jong
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA
| | - Yukitoshi Izumi
- Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St Louis, Missouri, USA
| | - Steven K Harmon
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA
| | - Charles F Zorumski
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA; Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St Louis, Missouri, USA
| | - Karen L ÓMalley
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, USA.
| |
Collapse
|
4
|
Mango D, Ledonne A. Updates on the Physiopathology of Group I Metabotropic Glutamate Receptors (mGluRI)-Dependent Long-Term Depression. Cells 2023; 12:1588. [PMID: 37371058 DOI: 10.3390/cells12121588] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Group I metabotropic glutamate receptors (mGluRI), including mGluR1 and mGluR5 subtypes, modulate essential brain functions by affecting neuronal excitability, intracellular calcium dynamics, protein synthesis, dendritic spine formation, and synaptic transmission and plasticity. Nowadays, it is well appreciated that the mGluRI-dependent long-term depression (LTD) of glutamatergic synaptic transmission (mGluRI-LTD) is a key mechanism by which mGluRI shapes connectivity in various cerebral circuitries, directing complex brain functions and behaviors, and that it is deranged in several neurological and psychiatric illnesses, including neurodevelopmental disorders, neurodegenerative diseases, and psychopathologies. Here, we will provide an updated overview of the physiopathology of mGluRI-LTD, by describing mechanisms of induction and regulation by endogenous mGluRI interactors, as well as functional physiological implications and pathological deviations.
Collapse
Affiliation(s)
- Dalila Mango
- School of Pharmacy, University of Rome "Tor Vergata", 00133 Rome, Italy
- Laboratory of Pharmacology of Synaptic Plasticity, European Brain Research Institute, 00161 Rome, Italy
| | - Ada Ledonne
- Department of Systems Medicine, University of Rome "Tor Vergata", 00133 Rome, Italy
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| |
Collapse
|
5
|
Crilly SE, Puthenveedu MA. Compartmentalized GPCR Signaling from Intracellular Membranes. J Membr Biol 2020; 254:259-271. [PMID: 33231722 DOI: 10.1007/s00232-020-00158-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/11/2020] [Indexed: 12/21/2022]
Abstract
G protein-coupled receptors (GPCRs) are integral membrane proteins that transduce a wide array of inputs including light, ions, hormones, and neurotransmitters into intracellular signaling responses which underlie complex processes ranging from vision to learning and memory. Although traditionally thought to signal primarily from the cell surface, GPCRs are increasingly being recognized as capable of signaling from intracellular membrane compartments, including endosomes, the Golgi apparatus, and nuclear membranes. Remarkably, GPCR signaling from these membranes produces functional effects that are distinct from signaling from the plasma membrane, even though often the same G protein effectors and second messengers are activated. In this review, we will discuss the emerging idea of a "spatial bias" in signaling. We will present the evidence for GPCR signaling through G protein effectors from intracellular membranes, and the ways in which this signaling differs from canonical plasma membrane signaling with important implications for physiology and pharmacology. We also highlight the potential mechanisms underlying spatial bias of GPCR signaling, including how intracellular membranes and their associated lipids and proteins affect GPCR activity and signaling.
Collapse
Affiliation(s)
- Stephanie E Crilly
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Manojkumar A Puthenveedu
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| |
Collapse
|
6
|
Forster YM, Green JL, Khatiwada A, Liberato JL, Narayana Reddy PA, Salvino JM, Bienz S, Bigler L, dos Santos WF, Karklin Fontana AC. Elucidation of the Structure and Synthesis of Neuroprotective Low Molecular Mass Components of the Parawixia bistriata Spider Venom. ACS Chem Neurosci 2020; 11:1573-1596. [PMID: 32343555 DOI: 10.1021/acschemneuro.0c00007] [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] [Indexed: 01/26/2023] Open
Abstract
The South American social spider Parawixia bistriata produces a venom containing complex organic compounds with intriguing biological activities. The crude venom leads to paralysis in termites and stimulates l-glutamate uptake and inhibits GABA uptake in rat brain synaptosomes. Glutamate is the major neurotransmitter at the insect neuromuscular junction and at the mammalian central nervous system, suggesting a modulation of the glutamatergic system by the venom. Parawixin1, 2, and 10 (Pwx1, 2 and 10) are HPLC fractions that demonstrate this bioactivity. Pwx1 stimulates l-glutamate uptake through the main transporter in the brain, EAAT2, and is neuroprotective in in vivo glaucoma models. Pxw2 inhibits GABA and glycine uptake in synaptosomes and inhibits seizures and neurodegeneration, and Pwx10 increases l-glutamate uptake in synaptosomes and is neuroprotective and anticonvulsant, shown in in vivo epilepsy models. Herein, we investigated the low molecular mass compounds in this venom and have found over 20 small compounds and 36 unique acylpolyamines with and without amino acid linkers. The active substances in fractions Pwx1 and Pwx2 require further investigation. We elucidated and confirmed the structure of the active acylpolyamine in Pwx10. Both fraction Pwx10 and the synthesized component enhance the activity of transporters EAAT1 and EAAT2, and, importantly, offer in vitro neuroprotection against excitotoxicity in primary cultures. These data suggest that compounds with this mechanism could be developed into therapies for disorders in which l-glutamate excitotoxicity is involved.
Collapse
Affiliation(s)
- Yvonne M. Forster
- Department of Chemistry, University of Zurich, Zurich, CH 8057, Switzerland
| | - Jennifer Leigh Green
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Apeksha Khatiwada
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - José Luiz Liberato
- Department of Biology, University of São Paulo, Ribeirão Preto, SP 14040-900, Brazil
| | | | - Joseph M. Salvino
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Stefan Bienz
- Department of Chemistry, University of Zurich, Zurich, CH 8057, Switzerland
| | - Laurent Bigler
- Department of Chemistry, University of Zurich, Zurich, CH 8057, Switzerland
| | | | - Andréia Cristina Karklin Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| |
Collapse
|
7
|
Jong YJI, Harmon SK, O’Malley KL. Location and Cell-Type-Specific Bias of Metabotropic Glutamate Receptor, mGlu 5, Negative Allosteric Modulators. ACS Chem Neurosci 2019; 10:4558-4570. [PMID: 31609579 DOI: 10.1021/acschemneuro.9b00415] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Emerging data indicate that G-protein coupled receptor (GPCR) signaling is determined by not only the agonist and a given receptor but also a variety of cell-type-specific factors that can influence a receptor's response. For example, the metabotropic glutamate receptor, mGlu5, which is implicated in a number of neuropsychiatric disorders such as depression, anxiety, and autism, also signals from inside the cell which leads to sustained Ca2+ mobilization versus rapid transient responses. Because mGlu5 is an important drug target, many negative allosteric modulators (NAMs) have been generated to modulate its activity. Here we show that NAMs such as AFQ056, AZD2066, and RG7090 elicit very different end points when tested in postnatal neuronal cultures expressing endogenous mGlu5 receptors. For example, AFQ056 fails to block intracellular mGlu5-mediated Ca2+ increases whereas RG7090 is very effective. These differences are not due to differential receptor levels, since about the same number of mGlu5 receptors are present on neurons from the cortex, hippocampus, and striatum based on pharmacological, biochemical, and molecular data. Moreover, biotinylation studies reveal that more than 90% of the receptor is intracellular in these neurons. Taken together, these data indicate that the tested NAMs exhibit both location-dependent and cell type specific bias for mGlu5-mediated Ca2+ mobilization which may affect clinical outcomes.
Collapse
Affiliation(s)
- Yuh-Jiin Ivy Jong
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Steven K. Harmon
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Karen L. O’Malley
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| |
Collapse
|
8
|
Gur M, Golcuk M, Yilmaz SZ, Taka E. Thermodynamic first law efficiency of membrane proteins. J Biomol Struct Dyn 2019; 38:439-449. [PMID: 30727820 DOI: 10.1080/07391102.2019.1577759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Proteins are nature's biomolecular machines. Proteins, such as transporters, pumps and motors, have complex function/operating-machinery/mechanisms, comparable to the macro-scaled machines that we encounter in our daily life. These proteins, as it is for their macro-scaled counterparts, convert (part of) other/various forms of energy into work. In this study, we are performing the first law analysis on a set of proteins, including the dopamine transporter, glycine transporters I and II, glutamate transporter, sodium-potassium pump and Ca2+ ATPase. Each of these proteins operates on a thermodynamic/mechanic cycle to perform their function. In each of these cycles, they receive energy from a source, convert part of this energy into work and reject the remaining part of the energy to the environment. Conservation of energy principle was applied to the thermodynamic/mechanic cycle of each protein, and thermodynamic first law efficiency was evaluated for each cycle, which shows how much of the energy input per cycle was converted into useful work. Interestingly, calculations based on experimental data indicate that proteins can operate under a range of efficiencies, which vary based on the extracellular and intracellular ion and substrate concentrations. The lowest observed first law efficiency was 50%, which is a very high value if compared to the efficiency of the macro-scaled heat engines we encounter in our daily lives.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Mert Gur
- Department of Mechanical Engineering, Istanbul Technical University (ITU), Istanbul, Turkey
| | - Mert Golcuk
- Department of Mechanical Engineering, Istanbul Technical University (ITU), Istanbul, Turkey
| | - Sema Zeynep Yilmaz
- Department of Mechanical Engineering, Istanbul Technical University (ITU), Istanbul, Turkey
| | - Elhan Taka
- Department of Mechanical Engineering, Istanbul Technical University (ITU), Istanbul, Turkey
| |
Collapse
|
9
|
Marks CR, Shonesy BC, Wang X, Stephenson JR, Niswender CM, Colbran RJ. Activated CaMKII α Binds to the mGlu 5 Metabotropic Glutamate Receptor and Modulates Calcium Mobilization. Mol Pharmacol 2018; 94:1352-1362. [PMID: 30282777 DOI: 10.1124/mol.118.113142] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/19/2018] [Indexed: 01/03/2023] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) and metabotropic glutamate receptor 5 (mGlu5) are critical signaling molecules in synaptic plasticity and learning/memory. Here, we demonstrate that mGlu5 is present in CaMKIIα complexes isolated from mouse forebrain. Further in vitro characterization showed that the membrane-proximal region of the C-terminal domain (CTD) of mGlu5a directly interacts with purified Thr286-autophosphorylated (activated) CaMKIIα However, the binding of CaMKIIα to this CTD fragment is reduced by the addition of excess Ca2+/calmodulin or by additional CaMKIIα autophosphorylation at non-Thr286 sites. Furthermore, in vitro binding of CaMKIIα is dependent on a tribasic residue motif Lys-Arg-Arg (KRR) at residues 866-868 of the mGlu5a-CTD, and mutation of this motif decreases the coimmunoprecipitation of CaMKIIα with full-length mGlu5a expressed in heterologous cells by about 50%. The KRR motif is required for two novel functional effects of coexpressing constitutively active CaMKIIα with mGlu5a in heterologous cells. First, cell-surface biotinylation studies showed that CaMKIIα increases the surface expression of mGlu5a Second, using Ca2+ fluorimetry and single-cell Ca2+ imaging, we found that CaMKIIα reduces the initial peak of mGlu5a-mediated Ca2+ mobilization by about 25% while doubling the relative duration of the Ca2+ signal. These findings provide new insights into the physical and functional coupling of these key regulators of postsynaptic signaling.
Collapse
Affiliation(s)
- Christian R Marks
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Brian C Shonesy
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Xiaohan Wang
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jason R Stephenson
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Colleen M Niswender
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Roger J Colbran
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| |
Collapse
|
10
|
Abstract
The trillions of synaptic connections within the human brain are shaped by experience and neuronal activity, both of which underlie synaptic plasticity and ultimately learning and memory. G protein-coupled receptors (GPCRs) play key roles in synaptic plasticity by strengthening or weakening synapses and/or shaping dendritic spines. While most studies of synaptic plasticity have focused on cell surface receptors and their downstream signaling partners, emerging data point to a critical new role for the very same receptors to signal from inside the cell. Intracellular receptors have been localized to the nucleus, endoplasmic reticulum, lysosome, and mitochondria. From these intracellular positions, such receptors may couple to different signaling systems, display unique desensitization patterns, and/or show distinct patterns of subcellular distribution. Intracellular GPCRs can be activated at the cell surface, endocytosed, and transported to an intracellular site or simply activated in situ by de novo ligand synthesis, diffusion of permeable ligands, or active transport of non-permeable ligands. Current findings reinforce the notion that intracellular GPCRs play a dynamic role in synaptic plasticity and learning and memory. As new intracellular GPCR roles are defined, the need to selectively tailor agonists and/or antagonists to both intracellular and cell surface receptors may lead to the development of more effective therapeutic tools.
Collapse
Affiliation(s)
- Yuh-Jiin I. Jong
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Steven K. Harmon
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Karen L. O’Malley
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| |
Collapse
|
11
|
Feng LR, Fernández-Martínez JL, Zaal KJ, deAndrés-Galiana EJ, Wolff BS, Saligan LN. mGluR5 mediates post-radiotherapy fatigue development in cancer patients. Transl Psychiatry 2018; 8:110. [PMID: 29849049 PMCID: PMC5976668 DOI: 10.1038/s41398-018-0161-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/26/2018] [Accepted: 04/11/2018] [Indexed: 02/06/2023] Open
Abstract
Cancer-related fatigue (CRF) is a common burden in cancer patients and little is known about its underlying mechanism. The primary aim of this study was to identify gene signatures predictive of post-radiotherapy fatigue in prostate cancer patients. We employed Fisher Linear Discriminant Analysis (LDA) to identify predictive genes using whole genome microarray data from 36 men with prostate cancer. Ingenuity Pathway Analysis was used to determine functional networks of the predictive genes. Functional validation was performed using a T lymphocyte cell line, Jurkat E6.1. Cells were pretreated with metabotropic glutamate receptor 5 (mGluR5) agonist (DHPG), antagonist (MPEP), or control (PBS) for 20 min before irradiation at 8 Gy in a Mark-1 γ-irradiator. NF-κB activation was assessed using a NF-κB/Jurkat/GFP Transcriptional Reporter Cell Line. LDA achieved 83.3% accuracy in predicting post-radiotherapy fatigue. "Glutamate receptor signaling" was the most significant (p = 0.0002) pathway among the predictive genes. Functional validation using Jurkat cells revealed clustering of mGluR5 receptors as well as increased regulated on activation, normal T cell expressed and secreted (RANTES) production post irradiation in cells pretreated with DHPG, whereas inhibition of mGluR5 activity with MPEP decreased RANTES concentration after irradiation. DHPG pretreatment amplified irradiation-induced NF-κB activation suggesting a role of mGluR5 in modulating T cell activation after irradiation. These results suggest that mGluR5 signaling in T cells may play a key role in the development of chronic inflammation resulting in fatigue and contribute to individual differences in immune responses to radiation. Moreover, modulating mGluR5 provides a novel therapeutic option to treat CRF.
Collapse
Affiliation(s)
- Li Rebekah Feng
- 0000 0001 2297 5165grid.94365.3dNational Institute of Nursing Research, National Institutes of Health, Bethesda, MD USA
| | | | - Kristien J.M. Zaal
- 0000 0001 2297 5165grid.94365.3dLight Imaging Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD USA
| | | | - Brian S. Wolff
- 0000 0001 2297 5165grid.94365.3dNational Institute of Nursing Research/National Cancer Institute, National Institutes of Health, Bethesda, MD USA
| | - Leorey N. Saligan
- 0000 0001 2297 5165grid.94365.3dNational Institute of Nursing Research, National Institutes of Health, Bethesda, MD USA
| |
Collapse
|
12
|
Jong YJI, Harmon SK, O'Malley KL. GPCR signalling from within the cell. Br J Pharmacol 2017; 175:4026-4035. [PMID: 28872669 DOI: 10.1111/bph.14023] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/08/2017] [Accepted: 08/17/2017] [Indexed: 12/22/2022] Open
Abstract
Traditionally, signal transduction from GPCRs is thought to emanate from the cell surface where receptor interactions with external stimuli can be transformed into a broad range of cellular responses. However, emergent data show that numerous GPCRs are also associated with various intracellular membranes where they may couple to different signalling systems, display unique desensitization patterns and/or exhibit distinct patterns of subcellular distribution. Although many GPCRs can be activated at the cell surface and subsequently endocytosed and transported to a unique intracellular site, other intracellular GPCRs can be activated in situ either via de novo ligand synthesis, diffusion of permeable ligands or active transport of nonpermeable ligands. Current findings reinforce the notion that intracellular GPCRs play a dynamic role in various biological functions including learning and memory, contractility and angiogenesis. As new intracellular GPCR roles are defined, the need to selectively tailor agonists and/or antagonists to both intracellular and cell surface receptors may lead to the development of more effective therapeutic tools. LINKED ARTICLES This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc.
Collapse
Affiliation(s)
- Yuh-Jiin I Jong
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Steven K Harmon
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Karen L O'Malley
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
13
|
Leidenheimer NJ. Cognate Ligand Chaperoning: a Novel Mechanism for the Post-translational Regulation of Neurotransmitter Receptor Biogenesis. Front Cell Neurosci 2017; 11:245. [PMID: 28860972 PMCID: PMC5559506 DOI: 10.3389/fncel.2017.00245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/02/2017] [Indexed: 11/13/2022] Open
Abstract
The functional unit for inter-neuronal communication in the central nervous system is the neuronal synapse. The number of postsynaptic neurotransmitter receptors at the cell surface is an important determinant of synaptic efficacy and plasticity. A diverse array of post-translational processes regulate postsynaptic receptor number, including receptor exocytosis, lateral diffusion, surface stabilization, endocytosis, and recycling, thus highlighting the importance of mechanisms that control postsynaptic receptor levels. Another putative post-translational mechanism for regulating receptor surface expression is cognate ligand chaperoning. It has been proposed that neurotransmitters function as cognate ligand chaperones by binding, within the endoplasmic reticulum (ER) lumen, to their nascent neurotransmitter receptors and facilitating receptor biogenesis. Here we discuss proof-of-concept evidence that small molecules can selectively facilitate the biogenesis of their targets and examine the specific evidence in support of cognate ligand chaperoning of neurotransmitter receptor biogenesis.
Collapse
Affiliation(s)
- Nancy J Leidenheimer
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences CenterShreveport, LA, United States
| |
Collapse
|