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Pagán OR. The complexities of ligand/receptor interactions: Exploring the role of molecular vibrations and quantum tunnelling. Bioessays 2024; 46:e2300195. [PMID: 38459808 DOI: 10.1002/bies.202300195] [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: 10/20/2023] [Revised: 01/19/2024] [Accepted: 02/19/2024] [Indexed: 03/10/2024]
Abstract
Molecular vibrations and quantum tunneling may link ligand binding to the function of pharmacological receptors. The well-established lock-and-key model explains a ligand's binding and recognition by a receptor; however, a general mechanism by which receptors translate binding into activation, inactivation, or modulation remains elusive. The Vibration Theory of Olfaction was proposed in the 1930s to explain this subset of receptor-mediated phenomena by correlating odorant molecular vibrations to smell, but a mechanism was lacking. In the 1990s, inelastic electron tunneling was proposed as a plausible mechanism for translating molecular vibration to odorant physiology. More recently, studies of ligands' vibrational spectra and the use of deuterated ligand analogs have provided helpful information to study this admittedly controversial hypothesis in metabotropic receptors other than olfactory receptors. In the present work, based in part on published experiments from our laboratory using planarians as an experimental organism, I will present a rationale and possible experimental approach for extending this idea to ligand-gated ion channels.
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Affiliation(s)
- Oné R Pagán
- Department of Biology, West Chester University, West Chester, Pennsylvania, USA
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2
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Pottie E, Stove CP. In vitro assays for the functional characterization of (psychedelic) substances at the serotonin receptor 5-HT 2A R. J Neurochem 2022; 162:39-59. [PMID: 34978711 DOI: 10.1111/jnc.15570] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/24/2021] [Accepted: 12/29/2021] [Indexed: 12/20/2022]
Abstract
Serotonergic psychedelics are substances that induce alterations in mood, perception, and thought, and have the activation of serotonin (5-HT) 2A receptors (5-HT2A Rs) as a main pharmacological mechanism. Besides their appearance on the (illicit) drug market, e.g. as new psychoactive substances, their potential therapeutic application is increasingly explored. This group of substances demonstrates a broad structural variety, leading to insufficiently described structure-activity relationships, hence illustrating the need for better functional characterization. This review therefore elaborates on the in vitro molecular techniques that have been used the most abundantly for the characterization of (psychedelic) 5-HT2A R agonists. More specifically, this review covers assays to monitor the canonical G protein signaling pathway (e.g. measuring G protein recruitment/activation, inositol phosphate accumulation, or Ca2+ mobilization), assays to monitor non-canonical G protein signaling (such as arachidonic acid release), assays to monitor β-arrestin recruitment or signaling, and assays to monitor receptor conformational changes. In particular, focus lies on the mechanism behind the techniques, and the specific advantages and challenges that are associated with these. Additionally, several variables are discussed that one should consider when attempting to compare functional outcomes from different studies, both linked to the specific assay mechanism and linked to its specific execution, as these may heavily impact the assay outcome.
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Affiliation(s)
- Eline Pottie
- Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Ghent University, Ghent, Belgium
| | - Christophe P Stove
- Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Ghent University, Ghent, Belgium
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3
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Mansour A, Nagi K, Dallaire P, Lukasheva V, Le Gouill C, Bouvier M, Pineyro G. Comprehensive Signaling Profiles Reveal Unsuspected Functional Selectivity of δ-Opioid Receptor Agonists and Allow the Identification of Ligands with the Greatest Potential for Inducing Cyclase Superactivation. ACS Pharmacol Transl Sci 2021; 4:1483-1498. [PMID: 34661070 PMCID: PMC8506601 DOI: 10.1021/acsptsci.1c00019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Indexed: 11/29/2022]
Abstract
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Prolonged exposure
to opioid receptor agonists triggers adaptations
in the adenylyl cyclase (AC) pathway that lead to enhanced production
of cyclic adenosine monophosphate (cAMP) upon withdrawal. This cellular
phenomenon contributes to withdrawal symptoms, hyperalgesia and analgesic
tolerance that interfere with clinical management of chronic pain
syndromes. Since δ-opioid receptors (DOPrs) are a promising
target for chronic pain management, we were interested in finding
out if cell-based signaling profiles as generated for drug discovery
purposes could inform us of the ligand potential to induce sensitization
of the cyclase path. For this purpose, signaling of DOPr agonists
was monitored at multiple effectors. The resulting signaling profiles
revealed marked functional selectivity, particularly for Met-enkephalin
(Met-ENK) whose signaling bias profile differed from those of synthetic
ligands like SNC-80 and ARM390. Signaling diversity among ligands
was systematized by clustering agonists according to similarities
in Emax and Log(τ) values for the
different responses. The classification process revealed that the
similarity in Gα/Gβγ, but not in β-arrestin
(βarr), responses was correlated with the potential of Met-ENK,
deltorphin II, (d-penicillamine2,5)-enkephalin (DPDPE), ARM390,
and SNC-80 to enhance cAMP production, all of which required Ca2+ mobilization to produce this response. Moreover, superactivation
by Met-ENK, which was the most-effective Ca2+ mobilizing
agonist, required Gαi/o activation, availability of Gβγ
subunits at the membrane, and activation of Ca2+ effectors
such as calmodulin and protein kinase C (PKC). In contrast, superactivation by (N-(l-tyrosyl)-(3S)-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)-l-phenylalanyl-l-phenylalanine (TIPP), which was set
in a distinct category through clustering, required activation of
Gαi/o subunits but was independent of the Gβγ dimer
and Ca2+ mobilization, relying instead on Src and Raf-1
to induce this cellular adaptation.
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Affiliation(s)
- Ahmed Mansour
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,CHU Sainte-Justine Research Center, Montréal, Quebec H3T 1C5, Canada
| | - Karim Nagi
- College of Medicine, QU Health, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Paul Dallaire
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,CHU Sainte-Justine Research Center, Montréal, Quebec H3T 1C5, Canada
| | - Viktoriya Lukasheva
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Christian Le Gouill
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Michel Bouvier
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Graciela Pineyro
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,CHU Sainte-Justine Research Center, Montréal, Quebec H3T 1C5, Canada
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4
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Kenakin T. Biased signaling as allosteric probe dependence. Cell Signal 2020; 79:109844. [PMID: 33242565 DOI: 10.1016/j.cellsig.2020.109844] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 11/07/2020] [Accepted: 11/19/2020] [Indexed: 01/14/2023]
Abstract
Signaling 'bias' is a phenomenon whereby the natural allosteric probe dependence of seven transmembrane receptors allows different receptor conformations (stabilized by different agonists) to activate some signaling pathways (coupled to pleiotropically coupled receptors) more than others at the expense of those other pathways. There are a number of relevant scenarios where such an activity could be therapeutically beneficial therefore there are practical reasons why this property of receptors should be exploited. This paper discusses recent ideas around attempts to harness this potentially useful idea and also the limitations around the current methods available to do so. Specifically, the determination of a quantitative value for the receptor bias of a given agonist that may translate to useful in vivo has been particularly elusive and studies need to be directed to solving this problem.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
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Cao D, Huang P, Chiu YT, Chen C, Wang H, Li M, Zheng Y, Ehlert FJ, Zhang Y, Liu-Chen LY. Comparison of Pharmacological Properties between the Kappa Opioid Receptor Agonist Nalfurafine and 42B, Its 3-Dehydroxy Analogue: Disconnect between in Vitro Agonist Bias and in Vivo Pharmacological Effects. ACS Chem Neurosci 2020; 11:3036-3050. [PMID: 32897695 DOI: 10.1021/acschemneuro.0c00407] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Nalfurafine, a moderately selective kappa opioid receptor (KOR) agonist, is used in Japan for treatment of itch without causing dysphoria or psychotomimesis. Here we characterized the pharmacology of compound 42B, a 3-dehydroxy analogue of nalfurafine and compared with that of nalfurafine. Nalfurafine and 42B acted as full KOR agonists and partial μ opioid receptor (MOR) agonists, but 42B showed much lower potency for both receptors and lower KOR/MOR selectivity, different from previous reports. Molecular modeling revealed that water-mediated hydrogen-bond formation between 3-OH of nalfurafine and KOR accounted for its higher KOR potency than 42B. The higher potency of both at KOR over MOR may be due to hydrogen-bond formation between nonconserved Y7.35 of KOR and their carbonyl groups. Both showed modest G protein signaling biases. In mice, like nalfurafine, 42B produced antinociceptive and antiscratch effects and did not cause conditioned place aversion (CPA) in the effective dose ranges. Unlike nalfurafine, 42B caused motor incoordination and hypolocomotion. As both agonists showed G protein biases, yet produced different effects on locomotor activity and motor incoordination, the findings and those in the literature suggest caution in correlating in vitro biochemical data with in vivo behavior effects. The factors contributing to the disconnect, including pharmacodynamic and pharmacokinetic issues, are discussed. In addition, our results suggest that among the KOR-induced adverse behaviors, CPA can be separated from motor incoordination and hypolocomotion.
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Affiliation(s)
- Danni Cao
- Center for Substance Abuse Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania 19140, United States
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, 100850, China
| | - Peng Huang
- Center for Substance Abuse Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania 19140, United States
| | - Yi-Ting Chiu
- Center for Substance Abuse Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania 19140, United States
| | - Chongguang Chen
- Center for Substance Abuse Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania 19140, United States
| | - Huiqun Wang
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Mengchu Li
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Yi Zheng
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Frederick J. Ehlert
- Department of Pharmaceutical Sciences, Center of Health Sciences, University of California, Irvine, California 92697, United States
| | - Yan Zhang
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Lee-Yuan Liu-Chen
- Center for Substance Abuse Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania 19140, United States
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Olsen RHJ, DiBerto JF, English JG, Glaudin AM, Krumm BE, Slocum ST, Che T, Gavin AC, McCorvy JD, Roth BL, Strachan RT. TRUPATH, an open-source biosensor platform for interrogating the GPCR transducerome. Nat Chem Biol 2020; 16:841-849. [PMID: 32367019 PMCID: PMC7648517 DOI: 10.1038/s41589-020-0535-8] [Citation(s) in RCA: 273] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 03/30/2020] [Indexed: 12/18/2022]
Abstract
G-protein-coupled receptors (GPCRs) remain major drug targets, despite our incomplete understanding of how they signal through 16 non-visual G-protein signal transducers (collectively named the transducerome) to exert their actions. To address this gap, we have developed an open-source suite of 14 optimized bioluminescence resonance energy transfer (BRET) Gαβγ biosensors (named TRUPATH) to interrogate the transducerome with single pathway resolution in cells. Generated through exhaustive protein engineering and empirical testing, the TRUPATH suite of Gαβγ biosensors includes the first Gα15 and GαGustducin probes. In head-to-head studies, TRUPATH biosensors outperformed first-generation sensors at multiple GPCRs and in different cell lines. Benchmarking studies with TRUPATH biosensors recapitulated previously documented signaling bias and revealed new coupling preferences for prototypic and understudied GPCRs with potential in vivo relevance. To enable a greater understanding of GPCR molecular pharmacology by the scientific community, we have made TRUPATH biosensors easily accessible as a kit through Addgene.
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Affiliation(s)
- Reid H J Olsen
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Jeffrey F DiBerto
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Justin G English
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Alexis M Glaudin
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Brian E Krumm
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Samuel T Slocum
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
- National Institute of Mental Health Psychoactive Drug Screening Program, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Tao Che
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Ariana C Gavin
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - John D McCorvy
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- National Institute of Mental Health Psychoactive Drug Screening Program, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.
| | - Ryan T Strachan
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA.
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Lind S, Holdfeldt A, Mårtensson J, Sundqvist M, Kenakin TP, Björkman L, Forsman H, Dahlgren C. Interdependent allosteric free fatty acid receptor 2 modulators synergistically induce functional selective activation and desensitization in neutrophils. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118689. [PMID: 32092308 DOI: 10.1016/j.bbamcr.2020.118689] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/04/2020] [Accepted: 02/20/2020] [Indexed: 01/06/2023]
Abstract
The non-activating allosteric modulator AZ1729, specific for free fatty acid receptor 2 (FFAR2), transfers the orthosteric FFAR2 agonists propionate and the P2Y2R specific agonist ATP into activating ligands that trigger an assembly of the neutrophil superoxide generating NADPH-oxidase. The homologous priming effect on the propionate response and the heterologous receptor cross-talk sensitized ATP response mediated by AZ1729 are functional characteristics shared with Cmp58, another non-activating allosteric FFAR2 modulator. In addition, AZ1729 also turned Cmp58 into a potent activator of the superoxide generating neutrophil NADPH-oxidase, and in agreement with the allosteric modulation concept, the effect was reciprocal in that Cmp58 turned AZ1729 into a potent activating allosteric agonist. The activation signals down-stream of FFAR2 when stimulated by the two interdependent allosteric modulators were biased in that, unlike for orthosteric agonists, the two complementary modulators together triggered an activation of the NADPH-oxidase, but not any transient rise in the cytosolic concentration of free calcium ions (Ca2+). Furthermore, following AZ1729/Cmp58 activation, the signaling by the desensitized FFAR2s was functionally selective in that the orthosteric agonist propionate could still induce a transient rise in intracellular Ca2+. The novel neutrophil activation and receptor down-stream signaling pattern mediated by the two cross-sensitizing allosteric FFAR2 modulators represent a new regulatory mechanism that controls receptor signaling.
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Affiliation(s)
- Simon Lind
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - André Holdfeldt
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Jonas Mårtensson
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden; Rheumatology Unit, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Martina Sundqvist
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Terry P Kenakin
- Department of Pharmacology, UNC-Chapel Hill, Chapel Hill, NC, USA
| | - Lena Björkman
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden; Rheumatology Unit, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Huamei Forsman
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Claes Dahlgren
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden.
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8
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Kenakin T. Prescient Indices of Activity: The Application of Functional System Sensitivity to Measurement of Drug Effect. Trends Pharmacol Sci 2019; 40:529-539. [PMID: 31109799 DOI: 10.1016/j.tips.2019.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 01/06/2023]
Abstract
Through pharmacological procedures, indices of drug activity can be obtained that transcend the systems in which they are measured. If (i) affinity, (ii) efficacies, (iii) orthosteric versus allosteric interaction, and (iv) rate of receptor offset can be determined, activity can be predicted in all systems. This can yield more detailed profiles (fingerprints) of efficacy to better define the required activities of follow-up molecules should the original candidates fail in the clinic. The use of functional assays of varying sensitivity is a major tool in the lead optimization process and the observation of candidate molecule profiles in multiple functional assays can reveal all properties of candidate molecules. In this review, the different indices for agonists, antagonists, and allosteric modulators are defined while highlighting the application of functional assays in deriving these indices.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, 120 Mason Farm Road, Room 4042 Genetic Medicine Building, CB# 7365, Chapel Hill, NC 27599-7365, USA.
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10
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Nicholson JR, Sommer B. The research domain criteria framework in drug discovery for neuropsychiatric diseases: focus on negative valence. Brain Neurosci Adv 2018; 2:2398212818804030. [PMID: 32166151 PMCID: PMC7058263 DOI: 10.1177/2398212818804030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/24/2018] [Indexed: 12/22/2022] Open
Abstract
Drug discovery, particularly in the field of central nervous system, has had very limited success in the last few decades. A likely contributor is the poor translation between preclinical and clinical phases. The Research Domain Criteria of the National Institutes of Mental Health is a framework which aims to identify new ways of classifying mental illnesses that are based on observable behaviour and neurobiological measures, and to provide a guiding and evolving framework to improve the translation from preclinical to clinical research. At the core of the Research Domain Criteria approach is the assumption that the dimensional constructs described can be assessed across different units of analysis, thus enabling a more precise quantitative understanding of their neurobiological underpinnings, increasing the likelihood of identifying new and effective therapeutic approaches. In the present review, we discuss how the Research Domain Criteria can be applied to drug discovery with the domain Negative Valence, construct Potential Threat (‘Anxiety’) as an example. We will discuss the evidence supporting the utility of the Research Domain Criteria approach and evaluate how close we are to achieving a common thread of translational research from gene to self-report.
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Affiliation(s)
- Janet R Nicholson
- CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Bernd Sommer
- CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
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11
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Barvitenko N, Lawen A, Aslam M, Pantaleo A, Saldanha C, Skverchinskaya E, Regolini M, Tuszynski JA. Integration of intracellular signaling: Biological analogues of wires, processors and memories organized by a centrosome 3D reference system. Biosystems 2018; 173:191-206. [PMID: 30142359 DOI: 10.1016/j.biosystems.2018.08.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/03/2018] [Accepted: 08/20/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Myriads of signaling pathways in a single cell function to achieve the highest spatio-temporal integration. Data are accumulating on the role of electromechanical soliton-like waves in signal transduction processes. Theoretical studies strongly suggest feasibility of both classical and quantum computing involving microtubules. AIM A theoretical study of the role of the complex composed of the plasma membrane and the microtubule-based cytoskeleton as a system that transmits, stores and processes information. METHODS Theoretical analysis presented here refers to (i) the Penrose-Hameroff theory of consciousness (Orchestrated Objective Reduction; Orch OR), (ii) the description of the centrosome as a reference system for construction of the 3D map of the cell proposed by Regolini, (iii) the Heimburg-Jackson model of the nerve pulse propagation along axons' lipid bilayer as soliton-like electro-mechanical waves. RESULTS AND CONCLUSION The ideas presented in this paper provide a qualitative model for the decision-making processes in a living cell undergoing a differentiation process. OUTLOOK This paper paves the way for the real-time live-cell observation of information processing by microtubule-based cytoskeleton and cell fate decision making.
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Affiliation(s)
| | - Alfons Lawen
- Monash University, School of Biomedical Sciences, Department of Biochemistry and Molecular Biology, VIC, 3800, Australia
| | - Muhammad Aslam
- Medical Clininc I, Cardiology/Angiology, University Hospital, Justus-Liebig-University, Giessen, Germany
| | - Antonella Pantaleo
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Carlota Saldanha
- Instituto de Medicina Molecular, Instituto de Bioquimica, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | | | - Marco Regolini
- Department of Bioengineering and Mathematical Modeling, AudioLogic, Milan, Italy
| | - Jack A Tuszynski
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada; Department of Physics, University of Alberta, Edmonton, Alberta, Canada; Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, IT-10128, Torino, Italy.
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12
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PAM-Antagonists: A Better Way to Block Pathological Receptor Signaling? Trends Pharmacol Sci 2018; 39:748-765. [PMID: 29885909 DOI: 10.1016/j.tips.2018.05.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022]
Abstract
Seven transmembrane receptor (7TMR) responses are modulated by orthosteric and allosteric ligands to great therapeutic advantage. Here we introduce a unique class of negative allosteric modulator (NAM) - the positive allosteric modulator (PAM)-antagonist - that increases the affinity of the receptor for the agonist but concomitantly decreases agonist efficacy when cobound. Notably, the reciprocation of allosteric energy causes the orthosteric agonist to increase the affinity of the receptor for the PAM-antagonist; thus, this modulator seeks out and destroys agonist-bound receptor complexes. When contrasted with standard orthosteric and allosteric antagonists it is clear that PAM-antagonists are uniquely well suited to reversing ongoing persistent agonism and provide favorable target coverage in vivo. Specifically, the therapeutic application of PAM-antagonists to reverse pathological overactivation (e.g., endothelin vasoconstriction) is emphasized.
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13
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Knutsen HK, Alexander J, Barregård L, Bignami M, Brüschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hogstrand C, Hoogenboom LR, Nebbia CS, Oswald IP, Petersen A, Rose M, Roudot AC, Schwerdtle T, Vollmer G, Wallace H, Benford D, Calò G, Dahan A, Dusemund B, Mulder P, Németh-Zámboriné É, Arcella D, Baert K, Cascio C, Levorato S, Schutte M, Vleminckx C. Update of the Scientific Opinion on opium alkaloids in poppy seeds. EFSA J 2018; 16:e05243. [PMID: 32625895 PMCID: PMC7009406 DOI: 10.2903/j.efsa.2018.5243] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Poppy seeds are obtained from the opium poppy (Papaver somniferum L.). They are used as food and to produce edible oil. The opium poppy plant contains narcotic alkaloids such as morphine and codeine. Poppy seeds do not contain the opium alkaloids, but can become contaminated with alkaloids as a result of pest damage and during harvesting. The European Commission asked EFSA to provide an update of the Scientific Opinion on opium alkaloids in poppy seeds. The assessment is based on data on morphine, codeine, thebaine, oripavine, noscapine and papaverine in poppy seed samples. The CONTAM Panel confirms the acute reference dose (ARfD) of 10 μg morphine/kg body weight (bw) and concluded that the concentration of codeine in the poppy seed samples should be taken into account by converting codeine to morphine equivalents, using a factor of 0.2. The ARfD is therefore a group ARfD for morphine and codeine, expressed in morphine equivalents. Mean and high levels of dietary exposure to morphine equivalents from poppy seeds considered to have high levels of opium alkaloids (i.e. poppy seeds from varieties primarily grown for pharmaceutical use) exceed the ARfD in most age groups. For poppy seeds considered to have relatively low concentrations of opium alkaloids (i.e. primarily varieties for food use), some exceedance of the ARfD is also seen at high levels of dietary exposure in most surveys. For noscapine and papaverine, the available data do not allow making a hazard characterisation. However, comparison of the dietary exposure to the recommended therapeutical doses does not suggest a health concern for these alkaloids. For thebaine and oripavine, no risk characterisation was done due to insufficient data. However, for thebaine, limited evidence indicates a higher acute lethality than for morphine and the estimated exposure could present a health risk.
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14
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Hoare SRJ, Pierre N, Moya AG, Larson B. Kinetic operational models of agonism for G-protein-coupled receptors. J Theor Biol 2018; 446:168-204. [PMID: 29486201 DOI: 10.1016/j.jtbi.2018.02.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 02/07/2018] [Accepted: 02/13/2018] [Indexed: 01/06/2023]
Abstract
The application of kinetics to research and therapeutic development of G-protein-coupled receptors has become increasingly valuable. Pharmacological models provide the foundation of pharmacology, providing concepts and measurable parameters such as efficacy and potency that have underlain decades of successful drug discovery. Currently there are few pharmacological models that incorporate kinetic activity in such a way as to yield experimentally-accessible drug parameters. In this study, a kinetic model of pharmacological response was developed that provides a kinetic descriptor of efficacy (the transduction rate constant, kτ) and allows measurement of receptor-ligand binding kinetics from functional data. The model assumes: (1) receptor interacts with a precursor of the response ("Transduction potential") and converts it to the response. (2) The response can decay. Familiar response vs time plots emerge, depending on whether transduction potential is depleted and/or response decays. These are the straight line, the "association" exponential curve, and the rise-and-fall curve. Convenient, familiar methods are described for measuring the model parameters and files are provided for the curve-fitting program Prism (GraphPad Software) that can be used as a guide. The efficacy parameter kτ is straightforward to measure and accounts for receptor reserve; all that is required is measurement of response over time at a maximally-stimulating concentration of agonist. The modular nature of the model framework allows it to be extended. Here this is done to incorporate antagonist-receptor binding kinetics and slow agonist-receptor equilibration. In principle, the modular framework can incorporate other cellular processes, such as receptor desensitization. The kinetic response model described here can be applied to measure kinetic pharmacological parameters than can be used to advance the understanding of GPCR pharmacology and optimize new and improved therapeutics.
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Affiliation(s)
- Samuel R J Hoare
- Pharmechanics, LLC, 14 Sunnyside Drive South, Owego NY 13827, USA.
| | | | | | - Brad Larson
- BioTek Instruments, Inc, 100 Tigan Street, Winooski, VT 05404, USA
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15
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Jones B, Bloom SR, Buenaventura T, Tomas A, Rutter GA. Control of insulin secretion by GLP-1. Peptides 2018; 100:75-84. [PMID: 29412835 DOI: 10.1016/j.peptides.2017.12.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 12/12/2022]
Abstract
Stimulation of insulin secretion by glucagon-like peptide-1 (GLP-1) and other gut-derived peptides is central to the incretin response to ingesting nutriments. Analogues of GLP-1, and inhibitors of its breakdown, have found widespread clinical use for the treatment of type 2 diabetes (T2D) and obesity. The release of these peptides underlies the improvements in glycaemic control and disease remission after bariatric surgery. Given therapeutically, GLP-1 analogues can lead to side effects including nausea, which limit dosage. Greater understanding of the interactions between the GLP-1 receptor (GLP-1R) and both the endogenous and artificial ligands therefore holds promise to provide more efficacious compounds. Here, we discuss recent findings concerning the signalling and trafficking of the GLP-1R in pancreatic beta cells. Leveraging "bias" at the receptor towards cAMP generation versus the recruitment of β-arrestins and extracellular signal-regulated kinases (ERK1/2) activation may allow the development of new analogues with significantly improved clinical efficacy. We describe how, unexpectedly, relatively low-affinity agonists, which prompt less receptor internalisation than the parent compound, provoke greater insulin secretion and consequent improvements in glycaemia.
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Affiliation(s)
- Ben Jones
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK
| | - Stephen R Bloom
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK
| | - Teresa Buenaventura
- Section of Cell Biology and Functional Genomics & Imperial Consortium for Islet Biology and Diabetes, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics & Imperial Consortium for Islet Biology and Diabetes, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics & Imperial Consortium for Islet Biology and Diabetes, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
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16
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Abstract
Allosteric modulation of the type 1 cannabinoid receptor (CB1R) holds great therapeutic potential. This is because allosteric modulators do not possess intrinsic efficacy, but instead augment (positive allosteric modulation) or diminish (negative allosteric modulation) the receptor's response to endogenous ligand. Consequently, CB1R allosteric modulators have an effect ceiling which allows for the tempering of CB1R signaling without the desensitization, tolerance, dependence, and psychoactivity associated with orthosteric compounds. Pain, movement disorders, epilepsy, obesity are all potential therapeutic targets for CB1R allosteric modulation. Several challenges exist for the development of CB1R allosteric modulators, such as receptor subtype specificity, translation to in vivo systems, and mixed allosteric/agonist/inverse agonist activity. Despite these challenges, elucidation of crystal structures of CB1R and compound design based on structure-activity relationships will advance the field. In this review, we will cover recent progress for CB1R allosteric modulators and discuss the future promise of this research.
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Affiliation(s)
- Mariam Alaverdashvili
- a College of Pharmacy and Nutrition , University of Saskatchewan , Saskatoon , Canada
| | - Robert B Laprairie
- a College of Pharmacy and Nutrition , University of Saskatchewan , Saskatoon , Canada
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17
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Kenakin T. Is the Quest for Signaling Bias Worth the Effort? Mol Pharmacol 2018; 93:266-269. [PMID: 29348268 DOI: 10.1124/mol.117.111187] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/12/2018] [Indexed: 01/14/2023] Open
Abstract
The question of whether signaling bias is a viable discovery strategy for drug therapy is discussed as a value proposition. On the positive side, bias is easily identified and quantified in simple in vitro functional assays with little resource expenditure. However, there are valid pharmacological reasons why these in vitro bias numbers may not accurately translate to in vivo therapeutic systems making the expectation of direct correspondence of in vitro bias to in vivo systems a problematic process. Presently, in vitro bias is used simply as a means to identify unique molecules to be advanced to more complex therapeutic assays but from this standpoint alone, the value proposition lies far to the positive. However, pharmacological attention needs to be given to the translational gap to reduce inevitable and costly attrition in biased molecule progression.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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18
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Michel MC, Charlton SJ. Biased Agonism in Drug Discovery-Is It Too Soon to Choose a Path? Mol Pharmacol 2018; 93:259-265. [PMID: 29326242 DOI: 10.1124/mol.117.110890] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/01/2018] [Indexed: 12/13/2022] Open
Abstract
A single receptor can activate multiple signaling pathways that have distinct or even opposite effects on cell function. Biased agonists stabilize receptor conformations preferentially stimulating one of these pathways, and therefore allow a more targeted modulation of cell function and treatment of disease. Dedicated development of biased agonists has led to promising drug candidates in clinical development, such as the G protein-biased µ opioid receptor agonist oliceridine. However, leveraging the theoretical potential of biased agonism for drug discovery faces several challenges. Some of these challenges are technical, such as techniques for quantitative analysis of bias and development of suitable screening assays; others are more fundamental, such as the need to robustly identify in a very early phase which cell type harbors the cellular target of the drug candidate, which signaling pathway leads to the desired therapeutic effect, and how these pathways may be modulated in the disease to be treated. We conclude that biased agonism has potential mainly in the treatment of conditions with a well-understood pathophysiology; in contrast, it may increase effort and commercial risk under circumstances where the pathophysiology has been less well defined, as is the case with many highly innovative treatments.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany (M.C.M.); Department of Life Sciences, University of Nottingham, Nottingham, United Kingdom (S.J.C.); and Excellerate Biosciences Ltd., MediCity, Nottingham, United Kingdom (S.J.C.)
| | - Steven J Charlton
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany (M.C.M.); Department of Life Sciences, University of Nottingham, Nottingham, United Kingdom (S.J.C.); and Excellerate Biosciences Ltd., MediCity, Nottingham, United Kingdom (S.J.C.)
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19
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Abstract
G protein-coupled receptors (GPCRs) are the largest class of receptors in the human genome and some of the most common drug targets. It is now well established that GPCRs can signal through multiple transducers, including heterotrimeric G proteins, GPCR kinases and β-arrestins. While these signalling pathways can be activated or blocked by 'balanced' agonists or antagonists, they can also be selectively activated in a 'biased' response. Biased responses can be induced by biased ligands, biased receptors or system bias, any of which can result in preferential signalling through G proteins or β-arrestins. At many GPCRs, signalling events mediated by G proteins and β-arrestins have been shown to have distinct biochemical and physiological actions from one another, and an accurate evaluation of biased signalling from pharmacology through physiology is crucial for preclinical drug development. Recent structural studies have provided snapshots of GPCR-transducer complexes, which should aid in the structure-based design of novel biased therapies. Our understanding of GPCRs has evolved from that of two-state, on-and-off switches to that of multistate allosteric microprocessors, in which biased ligands transmit distinct structural information that is processed into distinct biological outputs. The development of biased ligands as therapeutics heralds an era of increased drug efficacy with reduced drug side effects.
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20
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Rac1 plays a role in CXCL12 but not CCL3-induced chemotaxis and Rac1 GEF inhibitor NSC23766 has off target effects on CXCR4. Cell Signal 2018; 42:88-96. [DOI: 10.1016/j.cellsig.2017.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 12/17/2022]
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21
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Onfroy L, Galandrin S, Pontier SM, Seguelas MH, N'Guyen D, Sénard JM, Galés C. G protein stoichiometry dictates biased agonism through distinct receptor-G protein partitioning. Sci Rep 2017; 7:7885. [PMID: 28801617 PMCID: PMC5554226 DOI: 10.1038/s41598-017-07392-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/26/2017] [Indexed: 12/22/2022] Open
Abstract
Biased agonism at G protein coupled receptors emerges as an opportunity for development of drugs with enhanced benefit/risk balance making biased ligand identification a priority. However, ligand biased signature, classically inferred from ligand activity across multiple pathways, displays high variability in recombinant systems. Functional assays usually necessity receptor/effector overexpression that should be controlled among assays to allow comparison but this calibration currently fails. Herein, we demonstrate that Gα expression level dictates the biased profiling of agonists and, to a lesser extent of β-blockers, in a Gα isoform- and receptor-specific way, depending on specific G protein activity in different membrane territories. These results have major therapeutic implications since they suggest that the ligand bias phenotype is not necessarily maintained in pathological cell background characterized by fluctuations in G protein expression. Thus, we recommend implementation of G protein stoichiometry as a new parameter in biased ligand screening programs.
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Affiliation(s)
- Lauriane Onfroy
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université de Toulouse, F-31432, Toulouse, France
| | - Ségolène Galandrin
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université de Toulouse, F-31432, Toulouse, France
| | | | - Marie-Hélène Seguelas
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université de Toulouse, F-31432, Toulouse, France
| | - Du N'Guyen
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université de Toulouse, F-31432, Toulouse, France
| | - Jean-Michel Sénard
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université de Toulouse, F-31432, Toulouse, France.,Service de Pharmacologie Clinique, Centre Hospitalier Universitaire de Toulouse, Faculté de Médecine, Université de Toulouse, F-31000, Toulouse, France
| | - Céline Galés
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université de Toulouse, F-31432, Toulouse, France.
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22
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Kenakin T. A Scale of Agonism and Allosteric Modulation for Assessment of Selectivity, Bias, and Receptor Mutation. Mol Pharmacol 2017; 92:414-424. [PMID: 28679508 DOI: 10.1124/mol.117.108787] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 06/12/2017] [Indexed: 11/22/2022] Open
Abstract
An index of agonism is described that can be used to quantify agonist receptor selectivity, bias, cell-based agonism, and the effects of receptor mutation on signaling. The parameter is derived from agonist concentration-response curves and comprises the maximal response to the agonist (max) and the EC50 in the form of Δlog(max/EC50). This parameter is derived from equations describing agonists as positive allosteric facilitators of receptor-signaling protein interaction. A similar index is also derived to quantify the potentiating effects of positive allosteric modulators, which can be used to quantify in situ positive allosteric modulator activity in vivo. These indices lend themselves to statistical analysis and are system-independent in that the effects of the system processing of agonist response and differences in assay sensitivity and receptor expression are cancelled. The various applications of the Δlog(max/EC50) scale are described for each pharmacologic application.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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23
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Laprairie RB, Kulkarni PM, Deschamps JR, Kelly MEM, Janero DR, Cascio MG, Stevenson LA, Pertwee RG, Kenakin TP, Denovan-Wright EM, Thakur GA. Enantiospecific Allosteric Modulation of Cannabinoid 1 Receptor. ACS Chem Neurosci 2017; 8:1188-1203. [PMID: 28103441 DOI: 10.1021/acschemneuro.6b00310] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The cannabinoid 1 receptor (CB1R) is one of the most widely expressed metabotropic G protein-coupled receptors in brain, and its participation in various (patho)physiological processes has made CB1R activation a viable therapeutic modality. Adverse psychotropic effects limit the clinical utility of CB1R orthosteric agonists and have promoted the search for CB1R positive allosteric modulators (PAMs) with the promise of improved drug-like pharmacology and enhanced safety over typical CB1R agonists. In this study, we describe the synthesis and in vitro and ex vivo pharmacology of the novel allosteric CB1R modulator GAT211 (racemic) and its resolved enantiomers, GAT228 (R) and GAT229 (S). GAT211 engages CB1R allosteric site(s), enhances the binding of the orthosteric full agonist [3H]CP55,490, and reduces the binding of the orthosteric antagonist/inverse agonist [3H]SR141716A. GAT211 displayed both PAM and agonist activity in HEK293A and Neuro2a cells expressing human recombinant CB1R (hCB1R) and in mouse-brain membranes rich in native CB1R. GAT211 also exhibited a strong PAM effect in isolated vas deferens endogenously expressing CB1R. Each resolved and crystallized GAT211 enantiomer showed a markedly distinctive pharmacology as a CB1R allosteric modulator. In all biological systems examined, GAT211's allosteric agonist activity resided with the R-(+)-enantiomer (GAT228), whereas its PAM activity resided with the S-(-)-enantiomer (GAT229), which lacked intrinsic activity. These results constitute the first demonstration of enantiomer-selective CB1R positive allosteric modulation and set a precedent whereby enantiomeric resolution can decisively define the molecular pharmacology of a CB1R allosteric ligand.
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Affiliation(s)
| | - Pushkar M. Kulkarni
- Department
of Pharmaceutical Sciences, School of Pharmacy, Bouvé College
of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
| | - Jeffrey R. Deschamps
- Naval Research Laboratory, Code 6930, 4555 Overlook Avenue, Washington, D.C. 20375, United States
| | | | - David R. Janero
- Center
for Drug Discovery; Department of Pharmaceutical Sciences, School
of Pharmacy, Bouvé College of Health Sciences, Department of Chemistry and Chemical Biology, College of Science, and Health Sciences Entrepreneurs; Northeastern University, Boston, Massachusetts 02115, United States
| | - Maria G. Cascio
- School
of Medicine, Medical Sciences and Nutrition, Institute of Medical
Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, U.K
| | - Lesley A. Stevenson
- School
of Medicine, Medical Sciences and Nutrition, Institute of Medical
Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, U.K
| | - Roger G. Pertwee
- School
of Medicine, Medical Sciences and Nutrition, Institute of Medical
Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, U.K
| | - Terrence P. Kenakin
- Department
of Pharmacology, University of North Carolina School of Medicine, Chapel
Hill, North Carolina 27599, United States
| | | | - Ganesh A. Thakur
- Department
of Pharmaceutical Sciences, School of Pharmacy, Bouvé College
of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
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24
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Johnstone S, Albert JS. Pharmacological property optimization for allosteric ligands: A medicinal chemistry perspective. Bioorg Med Chem Lett 2017; 27:2239-2258. [PMID: 28408223 DOI: 10.1016/j.bmcl.2017.03.084] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 03/26/2017] [Accepted: 03/27/2017] [Indexed: 12/11/2022]
Abstract
New strategies to potentially improve drug safety and efficacy emerge with allosteric programs. Biased allosteric modulators can be designed with high subtype selectivity and defined receptor signaling endpoints, however, selecting the most meaningful parameters for optimization can be perplexing. Historically, "potency hunting" at the expense of physicochemical and pharmacokinetic optimization has led to numerous tool compounds with excellent pharmacological properties but no path to drug development. Conversely, extensive physicochemical and pharmacokinetic screening with only post hoc bias and allosteric characterization has led to inefficacious compounds or compounds with on-target toxicities. This field is rapidly evolving with new mechanistic understanding, changes in terminology, and novel opportunities. The intent of this digest is to summarize current understanding and debates within the field. We aim to discuss, from a medicinal chemistry perspective, the parameter choices available to drive SAR.
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Affiliation(s)
- Shawn Johnstone
- Department of Chemistry, IntelliSyn Pharma, 7171 Frederick-Banting, Montreal, Quebec H4S 1Z9, Canada.
| | - Jeffrey S Albert
- Department of Chemistry, IntelliSyn Pharma, 7171 Frederick-Banting, Montreal, Quebec H4S 1Z9, Canada; Department of Chemistry, AviSyn Pharma, 4275 Executive Square, Suite 200, La Jolla, CA 92037, United States.
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25
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Sullivan LC, Chavera TS, Jamshidi RJ, Berg KA, Clarke WP. Constitutive Desensitization of Opioid Receptors in Peripheral Sensory Neurons. J Pharmacol Exp Ther 2016; 359:411-419. [PMID: 27660244 PMCID: PMC5118646 DOI: 10.1124/jpet.116.232835] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 09/21/2016] [Indexed: 12/18/2022] Open
Abstract
Opioid receptors expressed by peripheral pain-sensing neurons are functionally inactive for antinociceptive signaling under most basal conditions; however, tissue damage or exposure to inflammatory mediators (e.g., bradykinin) converts these receptors from a nonresponsive state to a functionally competent state. Here we tested the hypothesis that the basal, nonresponsive state of the mu- and delta-opioid receptors (MOR and DOR, respectively) is the result of constitutive receptor activity that activates desensitization mechanisms, resulting in MOR and DOR receptor systems that are constitutively desensitized. Consistent with our previous findings, under basal conditions, neither the MOR agonist [d-Ala2,N-MePhe4,Gly-ol5]-enkephalin nor the DOR agonist [d-Pen2,5]-enkephalin, inhibited prostaglandin E2 (PGE2)-stimulated cAMP accumulation in peripheral sensory neurons in culture (ex vivo) or inhibited PGE2-stimulated thermal allodynia in the rat hind paw in vivo. Prolonged treatment with naloxone induced MOR and DOR responsiveness both in vivo and ex vivo to a similar magnitude as that produced by bradykinin. Also similar to bradykinin, the effect of naloxone persisted for 60 minutes after washout of the ligand. By contrast, prolonged treatment with 6β-naltrexol, did not induce functional competence of MOR or DOR but blocked the effect of naloxone. Treatment with siRNA for β-arrestin-2, but not β-arrestin-1, also induced MOR and DOR functional competence in cultured peripheral sensory neurons. These data suggest that the lack of responsiveness of MOR and DOR to agonist for antinociceptive signaling in peripheral sensory neurons is due to constitutive desensitization that is likely mediated by β-arrestin-2.
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MESH Headings
- Animals
- Bradykinin/pharmacology
- Drug Inverse Agonism
- Gene Expression Regulation/drug effects
- Gene Silencing
- Male
- Naloxone/pharmacology
- Nociception/drug effects
- RNA, Small Interfering/genetics
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Sensory Receptor Cells/drug effects
- Sensory Receptor Cells/metabolism
- beta-Arrestin 2/deficiency
- beta-Arrestin 2/genetics
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Affiliation(s)
- Laura C Sullivan
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Teresa S Chavera
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Raehannah J Jamshidi
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Kelly A Berg
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - William P Clarke
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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26
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Nguyen T, Li JX, Thomas BF, Wiley JL, Kenakin TP, Zhang Y. Allosteric Modulation: An Alternate Approach Targeting the Cannabinoid CB1 Receptor. Med Res Rev 2016; 37:441-474. [PMID: 27879006 PMCID: PMC5397374 DOI: 10.1002/med.21418] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 12/21/2022]
Abstract
The cannabinoid CB1 receptor is a G protein coupled receptor and plays an important role in many biological processes and physiological functions. A variety of CB1 receptor agonists and antagonists, including endocannabinoids, phytocannabinoids, and synthetic cannabinoids, have been discovered or developed over the past 20 years. In 2005, it was discovered that the CB1 receptor contains allosteric site(s) that can be recognized by small molecules or allosteric modulators. A number of CB1 receptor allosteric modulators, both positive and negative, have since been reported and importantly, they display pharmacological characteristics that are distinct from those of orthosteric agonists and antagonists. Given the psychoactive effects commonly associated with CB1 receptor agonists and antagonists/inverse agonists, allosteric modulation may offer an alternate approach to attain potential therapeutic benefits while avoiding inherent side effects of orthosteric ligands. This review details the complex pharmacological profiles of these allosteric modulators, their structure-activity relationships, and efforts in elucidating binding modes and mechanisms of actions of reported CB1 allosteric modulators. The ultimate development of CB1 receptor allosteric ligands could potentially lead to improved therapies for CB1-mediated neurological disorders.
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Affiliation(s)
- Thuy Nguyen
- Research Triangle Institute, Research Triangle Park, North Carolina
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York
| | - Brian F Thomas
- Research Triangle Institute, Research Triangle Park, North Carolina
| | - Jenny L Wiley
- Research Triangle Institute, Research Triangle Park, North Carolina
| | - Terry P Kenakin
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina
| | - Yanan Zhang
- Research Triangle Institute, Research Triangle Park, North Carolina
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27
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Kenakin T. New Modalities in Drug Therapy: Modifying Ongoing Chemical Conversations in the Brain. ACS Chem Neurosci 2016; 7:1472-1473. [PMID: 27739675 DOI: 10.1021/acschemneuro.6b00330] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The modification of ongoing chemical signaling in the brain through allosteric modification of seven transmembrane receptors offers a wealth of diverse beneficial outcomes in drug therapy. Specifically, biased agonism can emphasize beneficial signals and de-emphasize harmful signals thus increasing the effectiveness of agonists and opening up new vistas for previously precluded drug targets. In addition, the modification of natural agonism through positive and negative allostery can provide useful rejuvenation of failing systems.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27516, United States
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28
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Newton R, Giembycz MA. Understanding how long-acting β 2 -adrenoceptor agonists enhance the clinical efficacy of inhaled corticosteroids in asthma - an update. Br J Pharmacol 2016; 173:3405-3430. [PMID: 27646470 DOI: 10.1111/bph.13628] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/19/2016] [Accepted: 08/21/2016] [Indexed: 12/18/2022] Open
Abstract
In moderate-to-severe asthma, adding an inhaled long-acting β2 -adenoceptor agonist (LABA) to an inhaled corticosteroid (ICS) provides better disease control than simply increasing the dose of ICS. Acting on the glucocorticoid receptor (GR, gene NR3C1), ICSs promote anti-inflammatory/anti-asthma gene expression. In vitro, LABAs synergistically enhance the maximal expression of many glucocorticoid-induced genes. Other genes, including dual-specificity phosphatase 1(DUSP1) in human airways smooth muscle (ASM) and epithelial cells, are up-regulated additively by both drug classes. Synergy may also occur for LABA-induced genes, as illustrated by the bronchoprotective gene, regulator of G-protein signalling 2 (RGS2) in ASM. Such effects cannot be produced by either drug alone and may explain the therapeutic efficacy of ICS/LABA combination therapies. While the molecular basis of synergy remains unclear, mechanistic interpretations must accommodate gene-specific regulation. We explore the concept that each glucocorticoid-induced gene is an independent signal transducer optimally activated by a specific, ligand-directed, GR conformation. In addition to explaining partial agonism, this realization provides opportunities to identify novel GR ligands that exhibit gene expression bias. Translating this into improved therapeutic ratios requires consideration of GR density in target tissues and further understanding of gene function. Similarly, the ability of a LABA to interact with a glucocorticoid may be suboptimal due to low β2 -adrenoceptor density or biased β2 -adrenoceptor signalling. Strategies to overcome these limitations include adding-on a phosphodiesterase inhibitor and using agonists of other Gs-coupled receptors. In all cases, the rational design of ICS/LABA, and derivative, combination therapies requires functional knowledge of induced (and repressed) genes for therapeutic benefit to be maximized.
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Affiliation(s)
- Robert Newton
- Department of Cell Biology and Anatomy, Airways Inflammation Research Group, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Mark A Giembycz
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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29
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Davoren JE, Lee CW, Garnsey M, Brodney MA, Cordes J, Dlugolenski K, Edgerton JR, Harris AR, Helal CJ, Jenkinson S, Kauffman GW, Kenakin TP, Lazzaro JT, Lotarski SM, Mao Y, Nason DM, Northcott C, Nottebaum L, O’Neil SV, Pettersen B, Popiolek M, Reinhart V, Salomon-Ferrer R, Steyn SJ, Webb D, Zhang L, Grimwood S. Discovery of the Potent and Selective M1 PAM-Agonist N-[(3R,4S)-3-Hydroxytetrahydro-2H-pyran-4-yl]-5-methyl-4-[4-(1,3-thiazol-4-yl)benzyl]pyridine-2-carboxamide (PF-06767832): Evaluation of Efficacy and Cholinergic Side Effects. J Med Chem 2016; 59:6313-28. [DOI: 10.1021/acs.jmedchem.6b00544] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Stephen Jenkinson
- Drug
Safety Research and Development, Pfizer Worldwide Research and Development, La Jolla, California 92121, United States
| | | | - Terrence P. Kenakin
- Department
of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, United States
| | | | | | | | | | | | - Lisa Nottebaum
- Drug
Safety Research and Development, Pfizer Worldwide Research and Development, La Jolla, California 92121, United States
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30
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Michel MC, Korstanje C. β3-Adrenoceptor agonists for overactive bladder syndrome: Role of translational pharmacology in a repositioning clinical drug development project. Pharmacol Ther 2016; 159:66-82. [PMID: 26808167 DOI: 10.1016/j.pharmthera.2016.01.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
β3-Adrenoceptor agonists were originally considered as a promising drug class for the treatment of obesity and/or type 2 diabetes. When these development efforts failed, they were repositioned for the treatment of the overactive bladder syndrome. Based on the example of the β3-adrenoceptor agonist mirabegron, but also taking into consideration evidence obtained with ritobegron and solabegron, we discuss challenges facing a translational pharmacology program accompanying clinical drug development for a first-in-class molecule. Challenges included generic ones such as ligand selectivity, species differences and drug target gene polymorphisms. Challenges that are more specific included changing concepts of the underlying pathophysiology of the target condition while clinical development was under way; moreover, a paucity of public domain tools for the study of the drug target and aspects of receptor agonists as drugs had to be addressed. Nonetheless, a successful first-in-class launch was accomplished. Looking back at this translational pharmacology program, we conclude that a specifically tailored and highly flexible approach is required. However, several of the lessons learned may also be applicable to translational pharmacology programs in other indications.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
| | - Cees Korstanje
- Department of Drug Discovery Science & Management-Europe, Astellas Pharma Europe R&D, Leiden, The Netherlands
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31
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Anderson CA, Solari R, Pease JE. Biased agonism at chemokine receptors: obstacles or opportunities for drug discovery? J Leukoc Biol 2015; 99:901-9. [PMID: 26701135 DOI: 10.1189/jlb.2mr0815-392r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/01/2015] [Indexed: 01/14/2023] Open
Abstract
Chemokine receptors are typically promiscuous, binding more than one ligand, with the ligands themselves often expressed in different spatial localizations by multiple cell types. This is normally a tightly regulated process; however, in a variety of inflammatory disorders, dysregulation results in the excessive or inappropriate expression of chemokines that drives disease progression. Biased agonism, the phenomenon whereby different ligands of the same receptor are able to preferentially activate one signaling pathway over another, adds another level of complexity to an already complex system. In this minireview, we discuss the concept of biased agonism within the chemokine family and report that targeting single signaling axes downstream of chemokine receptors is not only achievable, but may well present novel opportunities to target chemokine receptors, allowing the fine tuning of receptor responses in the context of allergic inflammation and beyond.
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Affiliation(s)
- Caroline A Anderson
- Receptor Biology Group, Inflammation, Resolution and Development Section, National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, United Kingdom; and
| | - Roberto Solari
- Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, Norfolk Place, London, United Kingdom
| | - James E Pease
- Receptor Biology Group, Inflammation, Resolution and Development Section, National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, United Kingdom; and
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