1
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Yang L, Finlay DB, Green HM, Zhu X, Glass M, Duffull S. A quantitative pharmacology model for cannabinoid CB 1 receptor mediated by Gi/Gs protein competition. Br J Pharmacol 2024; 181:1324-1340. [PMID: 38072805 DOI: 10.1111/bph.16293] [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: 10/31/2022] [Revised: 10/29/2023] [Accepted: 11/20/2023] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND AND PURPOSE Orthosteric agonism of the CB1 receptor normally associates with Gi signalling resulting in a net inhibition of cAMP production. Empirical evidence shows CB1 causes a net cAMP stimulation through Gs coupling under two conditions: co-stimulation with the D2 receptor and high-level CB1 expression. Two hypotheses have been proposed to account for these paradoxical effects, (1) Gi is consumed by coupling to D2 or extra CB1 and excess CB1 binds to Gs and (2), the formation of dimers CB1 -CB1 or CB1 -D2 switches Gi/Gs preference. This study explored the mechanisms of Gi/Gs preference based on a mathematical model of the CB1 receptor. EXPERIMENTAL APPROACH The model was based on Hypothesis 1 and known mechanisms. The model was calibrated to align with multiple types of data (cAMP, Gi dissociation and internalisation). The key step of Hypothesis 1 was examined by simulation from the model. An experiment was proposed to distinguish Hypothesis 1 and 2. KEY RESULTS The model successfully descripted multiple types of data under Hypothesis 1. Simulations from the model indicated that precoupling of G protein with receptors is necessary for this hypothesis. The model designed experiments to distinguish Hypothesis 1 and 2 by increasing Gi & Gs in parallel with CB1 overexpression. The two hypotheses result in distinct cAMP responses. CONCLUSION AND IMPLICATIONS A mathematical model of CB1 -regulated Gi/Gs pathways was developed. It indicated Hypothesis 1 is feasible and G protein precoupling is a key step causing cAMP signalling switch. The model-designed experiments provided guides for future experimentation.
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Affiliation(s)
- Liang Yang
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Hayley M Green
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Xiao Zhu
- Department of Clinical Pharmacy and Pharmacy Administration, School of Pharmacy, Fudan University, Shanghai, China
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Stephen Duffull
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
- Certara, Princeton, New Jersey, USA
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2
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Fessl T, Majellaro M, Bondar A. Microscopy and spectroscopy approaches to study GPCR structure and function. Br J Pharmacol 2023. [PMID: 38087925 DOI: 10.1111/bph.16297] [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: 06/30/2023] [Revised: 11/03/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
The GPCR signalling cascade is a key pathway responsible for the signal transduction of a multitude of physical and chemical stimuli, including light, odorants, neurotransmitters and hormones. Understanding the structural and functional properties of the GPCR cascade requires direct observation of signalling processes in high spatial and temporal resolution, with minimal perturbation to endogenous systems. Optical microscopy and spectroscopy techniques are uniquely suited to this purpose because they excel at multiple spatial and temporal scales and can be used in living objects. Here, we review recent developments in microscopy and spectroscopy technologies which enable new insights into GPCR signalling. We focus on advanced techniques with high spatial and temporal resolution, single-molecule methods, labelling strategies and approaches suitable for endogenous systems and large living objects. This review aims to assist researchers in choosing appropriate microscopy and spectroscopy approaches for a variety of applications in the study of cellular signalling.
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Affiliation(s)
- Tomáš Fessl
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | | | - Alexey Bondar
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Laboratory of Microscopy and Histology, Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
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3
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Sadee W. Ligand-Free Signaling of G-Protein-Coupled Receptors: Physiology, Pharmacology, and Genetics. Molecules 2023; 28:6375. [PMID: 37687205 PMCID: PMC10489045 DOI: 10.3390/molecules28176375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) are ubiquitous sensors and regulators of cellular functions. Each GPCR exists in complex aggregates with multiple resting and active conformations. Designed to detect weak stimuli, GPCRs can also activate spontaneously, resulting in basal ligand-free signaling. Agonists trigger a cascade of events leading to an activated agonist-receptor G-protein complex with high agonist affinity. However, the ensuing signaling process can further remodel the receptor complex to reduce agonist affinity, causing rapid ligand dissociation. The acutely activated ligand-free receptor can continue signaling, as proposed for rhodopsin and μ opioid receptors, resulting in robust receptor activation at low agonist occupancy with enhanced agonist potency. Continued receptor stimulation can further modify the receptor complex, regulating sustained ligand-free signaling-proposed to play a role in opioid dependence. Basal, acutely agonist-triggered, and sustained elevated ligand-free signaling could each have distinct functions, reflecting multi-state conformations of GPCRs. This review addresses basal and stimulus-activated ligand-free signaling, its regulation, genetic factors, and pharmacological implications, focusing on opioid and serotonin receptors, and the growth hormone secretagogue receptor (GHSR). The hypothesis is proposed that ligand-free signaling of 5-HT2A receptors mediate therapeutic effects of psychedelic drugs. Research avenues are suggested to close the gaps in our knowledge of ligand-free GPCR signaling.
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Affiliation(s)
- Wolfgang Sadee
- Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA;
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
- Aether Therapeutics Inc., Austin, TX 78756, USA
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4
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Khoroshyy P, Martinez-Seara H, Myšková J, Lazar J. Dynamics of transition dipole moment orientation in representative fluorescent proteins. Phys Chem Chem Phys 2023; 25:22117-22123. [PMID: 37560975 DOI: 10.1039/d3cp01242e] [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: 08/11/2023]
Abstract
Molecules of fluorescent proteins (FPs) exhibit distinct optical directionality. This optical directionality is characterized by transition dipole moments (TDMs), and their orientation with respect to the molecular structures. Although our recent observations of FP crystals allowed us to determine the mean TDM directions with respect to the framework of representative FP molecules, the dynamics of TDM orientations within FP molecules remain to be ascertained. Here we describe the results of our investigations of the dynamics of TDM directions in the fluorescent proteins eGFP, mTurquoise2 and mCherry, through time-resolved fluorescence polarization measurements and microsecond time scale all-atom molecular dynamics (MD) simulations. The investigated FPs exhibit initial fluorescence anisotropies (r0) consistent with significant differences in the orientation of the excitation and emission TDMs. However, based on MD data, we largely attribute this observation to rapid (sub-nanosecond) fluorophore motions within the FP molecular framework. Our results allow improved determinations of orientational distributions of FP molecules by polarization microscopy, as well as more accurate interpretations of fluorescence resonance energy transfer (FRET) observations.
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Affiliation(s)
- Petro Khoroshyy
- Inst. of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, 160 00, Prague 6, Czech Republic
- 1st Faculty of Medicine, Charles University, Albertov 4, 128 00, Prague 2, Czech Republic.
| | - Hector Martinez-Seara
- Inst. of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, 160 00, Prague 6, Czech Republic
| | - Jitka Myšková
- 1st Faculty of Medicine, Charles University, Albertov 4, 128 00, Prague 2, Czech Republic.
| | - Josef Lazar
- Inst. of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, 160 00, Prague 6, Czech Republic
- 1st Faculty of Medicine, Charles University, Albertov 4, 128 00, Prague 2, Czech Republic.
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5
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Vleeshouwers W, van den Dries K, de Keijzer S, Joosten B, Lidke DS, Cambi A. Characterization of the Signaling Modalities of Prostaglandin E2 Receptors EP2 and EP4 Reveals Crosstalk and a Role for Microtubules. Front Immunol 2021; 11:613286. [PMID: 33643295 PMCID: PMC7907432 DOI: 10.3389/fimmu.2020.613286] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/18/2020] [Indexed: 11/13/2022] Open
Abstract
Prostaglandin E2 (PGE2) is a lipid mediator that modulates the function of myeloid immune cells such as macrophages and dendritic cells (DCs) through the activation of the G protein-coupled receptors EP2 and EP4. While both EP2 and EP4 signaling leads to an elevation of intracellular cyclic adenosine monophosphate (cAMP) levels through the stimulating Gαs protein, EP4 also couples to the inhibitory Gαi protein to decrease the production of cAMP. The receptor-specific contributions to downstream immune modulatory functions are still poorly defined. Here, we employed quantitative imaging methods to characterize the early EP2 and EP4 signaling events in myeloid cells and their contribution to the dissolution of adhesion structures called podosomes, which is a first and essential step in DC maturation. We first show that podosome loss in DCs is primarily mediated by EP4. Next, we demonstrate that EP2 and EP4 signaling leads to distinct cAMP production profiles, with EP4 inducing a transient cAMP response and EP2 inducing a sustained cAMP response only at high PGE2 levels. We further find that simultaneous EP2 and EP4 stimulation attenuates cAMP production, suggesting a reciprocal control of EP2 and EP4 signaling. Finally, we demonstrate that efficient signaling of both EP2 and EP4 relies on an intact microtubule network. Together, these results enhance our understanding of early EP2 and EP4 signaling in myeloid cells. Considering that modulation of PGE2 signaling is regarded as an important therapeutic possibility in anti-tumor immunotherapy, our findings may facilitate the development of efficient and specific immune modulators of PGE2 receptors.
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Affiliation(s)
- Ward Vleeshouwers
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Koen van den Dries
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Sandra de Keijzer
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Ben Joosten
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Diane S Lidke
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States.,Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Alessandra Cambi
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
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6
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Bondar A, Rybakova O, Melcr J, Dohnálek J, Khoroshyy P, Ticháček O, Timr Š, Miclea P, Sakhi A, Marková V, Lazar J. Quantitative linear dichroism imaging of molecular processes in living cells made simple by open software tools. Commun Biol 2021; 4:189. [PMID: 33580182 PMCID: PMC7881160 DOI: 10.1038/s42003-021-01694-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 01/11/2021] [Indexed: 11/09/2022] Open
Abstract
Fluorescence-detected linear dichroism microscopy allows observing various molecular processes in living cells, as well as obtaining quantitative information on orientation of fluorescent molecules associated with cellular features. Such information can provide insights into protein structure, aid in development of genetically encoded probes, and allow determinations of lipid membrane properties. However, quantitating and interpreting linear dichroism in biological systems has been laborious and unreliable. Here we present a set of open source ImageJ-based software tools that allow fast and easy linear dichroism visualization and quantitation, as well as extraction of quantitative information on molecular orientations, even in living systems. The tools were tested on model synthetic lipid vesicles and applied to a variety of biological systems, including observations of conformational changes during G-protein signaling in living cells, using fluorescent proteins. Our results show that our tools and model systems are applicable to a wide range of molecules and polarization-resolved microscopy techniques, and represent a significant step towards making polarization microscopy a mainstream tool of biological imaging.
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Affiliation(s)
- Alexey Bondar
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Science, Nove Hrady, Czech Republic
| | - Olga Rybakova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Science, Nove Hrady, Czech Republic
| | - Josef Melcr
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- Groningen Biomolecular Sciences and Biotechnology Institute and the Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Jan Dohnálek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
| | - Petro Khoroshyy
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Science, Nove Hrady, Czech Republic
| | - Ondřej Ticháček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
| | - Štěpán Timr
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 rue Pierre et Marie Curie, Paris, France
- Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France
| | - Paul Miclea
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Science, Nove Hrady, Czech Republic
| | - Alina Sakhi
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
| | - Vendula Marková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic
- Faculty of Sciences, Charles University, Prague, Czech Republic
| | - Josef Lazar
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6, Czech Republic.
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Science, Nove Hrady, Czech Republic.
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7
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Bondar A, Lazar J. Optical sensors of heterotrimeric G protein signaling. FEBS J 2020; 288:2570-2584. [DOI: 10.1111/febs.15655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/26/2020] [Accepted: 12/03/2020] [Indexed: 01/14/2023]
Affiliation(s)
- Alexey Bondar
- Center for Nanobiology and Structural Biology Institute of Microbiology of the Czech Academy of Sciences Nove Hrady Czech Republic
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - Josef Lazar
- Center for Nanobiology and Structural Biology Institute of Microbiology of the Czech Academy of Sciences Nove Hrady Czech Republic
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic
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8
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Myšková J, Rybakova O, Brynda J, Khoroshyy P, Bondar A, Lazar J. Directionality of light absorption and emission in representative fluorescent proteins. Proc Natl Acad Sci U S A 2020; 117:32395-32401. [PMID: 33273123 PMCID: PMC7768707 DOI: 10.1073/pnas.2017379117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/30/2020] [Indexed: 12/13/2022] Open
Abstract
Fluorescent molecules are like antennas: The rate at which they absorb light depends on their orientation with respect to the incoming light wave, and the apparent intensity of their emission depends on their orientation with respect to the observer. However, the directions along which the most important fluorescent molecules in biology, fluorescent proteins (FPs), absorb and emit light are generally not known. Our optical and X-ray investigations of FP crystals have now allowed us to determine the molecular orientations of the excitation and emission transition dipole moments in the FPs mTurquoise2, eGFP, and mCherry, and the photoconvertible FP mEos4b. Our results will allow using FP directionality in studies of molecular and biological processes, but also in development of novel bioengineering and bioelectronics applications.
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Affiliation(s)
- Jitka Myšková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - Olga Rybakova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
- Institute of Microbiology, Czech Academy of Sciences, 37333 Nové Hrady, Czech Republic
| | - Jiří Brynda
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
- Institute of Molecular Genetics, Czech Academy of Sciences, 14220 Prague 4, Czech Republic
| | - Petro Khoroshyy
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
- Institute of Microbiology, Czech Academy of Sciences, 37333 Nové Hrady, Czech Republic
| | - Alexey Bondar
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
- Institute of Microbiology, Czech Academy of Sciences, 37333 Nové Hrady, Czech Republic
| | - Josef Lazar
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic;
- Institute of Microbiology, Czech Academy of Sciences, 37333 Nové Hrady, Czech Republic
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9
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Fantauzzi MF, Aguiar JA, Tremblay BJM, Mansfield MJ, Yanagihara T, Chandiramohan A, Revill S, Ryu MH, Carlsten C, Ask K, Stämpfli M, Doxey AC, Hirota JA. Expression of endocannabinoid system components in human airway epithelial cells: impact of sex and chronic respiratory disease status. ERJ Open Res 2020; 6:00128-2020. [PMID: 33344628 PMCID: PMC7737429 DOI: 10.1183/23120541.00128-2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022] Open
Abstract
Cannabis smoking is the dominant route of delivery, with the airway epithelium functioning as the site of first contact. The endocannabinoid system is responsible for mediating the physiological effects of inhaled phytocannabinoids. The expression of the endocannabinoid system in the airway epithelium and contribution to normal physiological responses remains to be defined. To begin to address this knowledge gap, a curated dataset of 1090 unique human bronchial brushing gene expression profiles was created. The dataset included 616 healthy subjects, 136 subjects with asthma, and 338 subjects with COPD. A 32-gene endocannabinoid signature was analysed across all samples with sex and disease-specific analyses performed. Immunohistochemistry and immunoblots were performed to probe in situ and in vitro protein expression. CB1, CB2, and TRPV1 protein signal is detectable in human airway epithelial cells in situ and in vitro, justifying examining the downstream endocannabinoid pathway. Sex status was associated with differential expression of 7 of 32 genes. In contrast, disease status was associated with differential expression of 21 of 32 genes in people with asthma and 26 of 32 genes in people with COPD. We confirm at the protein level that TRPV1, the most differentially expressed candidate in our analyses, was upregulated in airway epithelial cells from people with asthma relative to healthy subjects. Our data demonstrate that the endocannabinoid system is expressed in human airway epithelial cells with expression impacted by disease status and minimally by sex. The data suggest that cannabis consumers may have differential physiological responses in the respiratory mucosa.
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Affiliation(s)
- Matthew F Fantauzzi
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada.,McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
| | | | | | - Michael J Mansfield
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Toyoshi Yanagihara
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada
| | - Abiram Chandiramohan
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada
| | - Spencer Revill
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada
| | - Min Hyung Ryu
- Division of Respiratory Medicine, Dept of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Chris Carlsten
- Division of Respiratory Medicine, Dept of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Kjetil Ask
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada.,McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
| | - Martin Stämpfli
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada.,McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
| | - Andrew C Doxey
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada.,Dept of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Jeremy A Hirota
- Firestone Institute for Respiratory Health - Division of Respirology, Dept of Medicine, McMaster University, Hamilton, ON, Canada.,McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada.,Dept of Biology, University of Waterloo, Waterloo, ON, Canada.,Division of Respiratory Medicine, Dept of Medicine, University of British Columbia, Vancouver, BC, Canada
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10
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Nishiguchi T, Yoshimura H, Kasai RS, Fujiwara TK, Ozawa T. Synergetic Roles of Formyl Peptide Receptor 1 Oligomerization in Ligand-Induced Signal Transduction. ACS Chem Biol 2020; 15:2577-2587. [PMID: 32808756 DOI: 10.1021/acschembio.0c00631] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
G protein-coupled receptors (GPCRs) transduce extracellular signals into cells by interacting with G proteins and arrestins. Emerging evidence suggests that GPCRs on the plasma membrane are in a dynamic equilibrium among monomers, dimers, and larger oligomers. Nevertheless, the role of the oligomer formation in the GPCR signal transduction remains unclear. Using multicolor single-molecule live-cell imaging, we show a dynamic interconversion between small and large oligomer states of a chemoattractant GPCR, Formyl Peptide Receptor 1 (FPR1), and its binding affinity with G protein. Full agonist stimulation increased a fraction of large FPR1 oligomers, which allowed for prolonged FPR1-G protein interaction. The G protein interaction with FPR1 was most stabilized at the full agonist-bound large FPR1 oligomers. Based on these results, we propose that G protein-mediated signal transduction may be regulated synergistically by the ligand-binding and FPR1 oligomerization. Cooperative signal control induced by receptor oligomerization is anticipated as a target for drug discovery.
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Affiliation(s)
- Tomoki Nishiguchi
- School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hideaki Yoshimura
- School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Rinshi S. Kasai
- Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takahiro K. Fujiwara
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takeaki Ozawa
- School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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11
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Franco R, Castelló J, Canela EI. The Kinetic Component in Drug Discovery: Using the Most Basic Pharmacological Concepts to Advance in Selecting Drugs to Combat CNS Diseases. Curr Neuropharmacol 2020; 18:250-257. [PMID: 31573886 PMCID: PMC7327946 DOI: 10.2174/1570159x17666191001144309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/02/2019] [Accepted: 09/24/2019] [Indexed: 01/14/2023] Open
Abstract
To reach the central nervous system (CNS), drugs must cross the brain-blood barrier and have appropriate pharmacokinetic/dynamic properties. However, in early drug discovery steps, the selection of lead compounds, for example, those targeting G-protein-coupled receptors (GPCRs), is made according to i) affinity, which is calculated in in vitro equilibrium conditions, and ii) potency, a signal transduction-related parameter, usually quantified at a fixed time-point in a heterologous expression system. This paper argues that kinetics must be considered in the early steps of lead compound selection. While affinity calculation requires the establishment of a ligand-receptor equilibrium, the signal transduction starts as soon as the receptor senses the agonist. Taking cAMP production as an example, the in vitro-measured cytoplasmic levels of this cyclic nucleotide do not depend on equilibrium dissociation constant, KD. Signaling occurs far from the equilibrium and correlates more with the binding rate (kon) than with KD. Furthermore, residence time, a parameter to consider in lead optimization, may significantly vary from in vitro to in vivo conditions. The results are discussed from the perspective of dopaminergic neurotransmission and dopaminereceptor- based drug discovery.
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Affiliation(s)
- Rafael Franco
- Department of Biochemistry and Molecular Biomedicine, Molecular Neurobiology Laboratory, Biology School, University of Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Josema Castelló
- Department of Biochemistry and Molecular Biomedicine, Molecular Neurobiology Laboratory, Biology School, University of Barcelona, Barcelona, Spain
| | - Enric I. Canela
- Department of Biochemistry and Molecular Biomedicine, Molecular Neurobiology Laboratory, Biology School, University of Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
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12
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GHSR-D2R heteromerization modulates dopamine signaling through an effect on G protein conformation. Proc Natl Acad Sci U S A 2018; 115:4501-4506. [PMID: 29632174 DOI: 10.1073/pnas.1712725115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The growth hormone secretagogue receptor (GHSR) and dopamine receptor (D2R) have been shown to oligomerize in hypothalamic neurons with a significant effect on dopamine signaling, but the molecular processes underlying this effect are still obscure. We used here the purified GHSR and D2R to establish that these two receptors assemble in a lipid environment as a tetrameric complex composed of two each of the receptors. This complex further recruits G proteins to give rise to an assembly with only two G protein trimers bound to a receptor tetramer. We further demonstrate that receptor heteromerization directly impacts on dopamine-mediated Gi protein activation by modulating the conformation of its α-subunit. Indeed, association to the purified GHSR:D2R heteromer triggers a different active conformation of Gαi that is linked to a higher rate of GTP binding and a faster dissociation from the heteromeric receptor. This is an additional mechanism to expand the repertoire of GPCR signaling modulation that could have implications for the control of dopamine signaling in normal and physiopathological conditions.
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