1
|
Rodriguez-Contreras D, García-Nafría J, Chan AE, Shinde U, Neve KA. Comparison of the function of two novel human dopamine D2 receptor variants identifies a likely mechanism for their pathogenicity. Biochem Pharmacol 2024:116228. [PMID: 38643909 DOI: 10.1016/j.bcp.2024.116228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/29/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
Two recently discovered DRD2 mutations, c.634A > T, p.Ile212Phe and c.1121T > G, p.Met374Arg, cause hyperkinetic movement disorders that have overlapping features but apparently differ in severity. The two known carriers of the Met374Arg variant had early childhood disease onset and more severe motor, cognitive, and neuropsychiatric deficits than any known carriers of the Ile212Phe variant, whose symptoms were first apparent in adolescence. Here, we evaluated if differences in the function of the two variants in cultured cells could explain differing pathogenicity. Both variants were expressed less abundantly than the wild type receptor and exhibited loss of agonist-induced arrestin binding, but differences in expression and arrestin binding between the variants were minor. Basal and agonist-induced activation of heterotrimeric Gi/o/z proteins, however, showed clear differences; agonists were generally more potent at Met374Arg than at the Ile212Phe or wild type variants. Furthermore, all Gα subtypes tested were constitutively activated more by Met374Arg than by Ile212Phe. Met374Arg produced greater constitutive inhibition of cyclic AMP accumulation than Ile212Phe or the wild type D2 receptor. Met374Arg and Ile212Phe were more sensitive to thermal inactivation than the wild type D2 receptor, as reported for other constitutively active receptors, but Ile212Phe was affected more than Met374Arg. Additional pharmacological characterization suggested that the mutations differentially affect the shape of the agonist binding pocket and the potency of dopamine, norepinephrine, and tyramine. Molecular dynamics simulations provided a structural rationale for enhanced constitutive activation and agonist potency. Enhanced constitutive and agonist-induced G protein-mediated signaling likely contributes to the pathogenicity of these novel variants.
Collapse
Affiliation(s)
- Dayana Rodriguez-Contreras
- Research Service, Veterans Affairs Portland Health Care System, and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
| | - Javier García-Nafría
- Institute for Biocomputation and Physics of Complex Systems (BIFI) and Laboratory of Advanced Microscopy (LMA), University of Zaragoza, 50018, Zaragoza, Spain
| | - Amy E Chan
- Research Service, Veterans Affairs Portland Health Care System, and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ujwal Shinde
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kim A Neve
- Research Service, Veterans Affairs Portland Health Care System, and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA.
| |
Collapse
|
2
|
Onaran HO, Costa T. Why classical receptor theory, which ignores allostery, can effectively measure the strength of an allosteric effect as agonist's efficacy. Br J Pharmacol 2024. [PMID: 38343142 DOI: 10.1111/bph.16327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/17/2023] [Accepted: 01/07/2024] [Indexed: 02/21/2024] Open
Abstract
BACKGROUND AND PURPOSE The classical theory of receptor action has been used for decades as a powerful tool to estimate molecular determinants of ligand-induced receptor activation (i.e., affinity and efficacy) from experimentally observable biological responses. However, it is also a well-recognized fact that the receptor-binding and activation mechanisms, and the parameters thereof, described in the classical theory contradict with the modern view of receptor activation based on allosteric principles. EXPERIMENTAL APPROACH We used mathematical analysis, along with some numerical simulations, to answer the key question as to what extent the classical theory is compatible-if at all-with the modern understanding of receptor activation. KEY RESULTS Here, we showed conclusively that (1) receptor activation equations based on allosteric principles contain the logic of the classical theory in disguise, and therefore, (2) estimates of "intrinsic efficacy" (ε) obtained by means of classical techniques (i.e., null methods or fitting the operational model to concentration-response data) are equivalent to the allosteric coupling factors that represent the molecular efficacy of ligands. CONCLUSION AND IMPLICATIONS Thus, we conclude that despite the justified criticisms it has received so far, the classical theory may continue to be useful in estimating ligand efficacy from experimental data, if used properly. Here, we also provide rigorous criteria for the proper use of the theory. These findings not only have implications for ligand classification but also resolve some long lasting discussions in the field of bias agonism in GPCR, which requires reasonable estimates of relative ligand efficacies at different signalling pathways.
Collapse
Affiliation(s)
- H Ongun Onaran
- Department of Pharmacology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Tommaso Costa
- Istituto Superiore di Sanità (retired), Viale America 111, Rome, Italy
| |
Collapse
|
3
|
Hamed O, Jayasinghe V, Giembycz MA. The β-Blocker Carvedilol and Related Aryloxypropanolamines Promote ERK1/2 Phosphorylation in HEK293 Cells with K A Values Distinct From Their Equilibrium Dissociation Constants as β 2-Adrenoceptor Antagonists: Evidence for Functional Affinity. J Pharmacol Exp Ther 2024; 388:688-700. [PMID: 38129128 DOI: 10.1124/jpet.123.001920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/06/2023] [Accepted: 11/13/2023] [Indexed: 12/23/2023] Open
Abstract
The determination of affinity by using functional assays is important in drug discovery because it provides a more relevant estimate of the strength of interaction of a ligand to its cognate receptor than radioligand binding. However, empirical evidence for so-called, "functional affinity" is limited. Herein, we determined whether the affinity of carvedilol, a β-adrenoceptor antagonist used to treat heart failure that also promotes extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylation, differed between these two pharmacological activities. Four structurally related β-adrenoceptor antagonists (alprenolol, carazolol, pindolol, propranolol) that also activated ERK1/2 were included as comparators to enhance our understanding of how these drugs work in the clinical setting. In HEK293 cells stably expressing the human β 2-adrenoceptor carvedilol and related aryloxypropanolamines were partial agonists of ERK1/2 phosphorylation with potencies ([A]50s) that were lower than their equilibrium dissociation constants (K Bs) as β 2-adrenoceptor antagonists. As the [A]50 of a partial agonist is a good approximation of its K B, then these data indicated that the affinities of carvedilol and related ligands for these two activities were distinct. Moreover, there was a significant negative rank order correlation between the [A]50 of each ligand to activate ERK1/2 and their intrinsic activities (i.e., as intrinsic activity for ERK1/2 phosphorylation increased, so did affinity). Genome editing revealed that the transducer that coupled the β 2-adrenoceptor to ERK1/2 phosphorylation in response to carvedilol and other β 2-adrenoceptor antagonists was Gαs. Collectively, these data support the concept of "functional affinity" and indicate that the ability of the β 2-adrenoceptor to recruit Gαs may influence the affinity of the activating ligand. SIGNIFICANCE STATEMENT: In HEK293 cells overexpressing the human β2-adrenoceptor carvedilol and four related aryloxypropanolamines behaved as β2-adrenoceptor antagonists and partial agonists of ERK1/2 phosphorylation with rank orders of affinity that were distinct. These data imply that carvedilol and other β-blockers can stabilize the β2-adrenoceptor in different affinity conformations that are revealed when functionally distinct responses are measured. This is the basis for the pharmacological concept of "functional affinity."
Collapse
Affiliation(s)
- Omar Hamed
- Lung Health Research Group, Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Varuna Jayasinghe
- Lung Health Research Group, Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mark A Giembycz
- Lung Health Research Group, Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
4
|
Yuan G, Dhaynaut M, Guehl NJ, Afshar S, Huynh D, Moon SH, Iyengar SM, Jain MK, Pickett JE, Kang HJ, Ondrechen MJ, El Fakhri G, Normandin MD, Brownell AL. Design, Synthesis, and Characterization of [ 18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2. J Med Chem 2022; 65:9939-9954. [PMID: 35802702 PMCID: PMC9434700 DOI: 10.1021/acs.jmedchem.2c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An array of triazolopyridines based on JNJ-46356479 (6) were synthesized as potential positron emission tomography radiotracers for metabotropic glutamate receptor 2 (mGluR2). The selected candidates 8-10 featured enhanced positive allosteric modulator (PAM) activity (20-fold max.) and mGluR2 agonist activity (25-fold max.) compared to compound 6 in the cAMP GloSensor assays. Radiolabeling of compounds 8 and 9 (mG2P026) was achieved via Cu-mediated radiofluorination with satisfactory radiochemical yield, >5% (non-decay-corrected); high molar activity, >180 GBq/μmol; and excellent radiochemical purity, >98%. Preliminary characterization of [18F]8 and [18F]9 in rats confirmed their excellent brain permeability and binding kinetics. Further evaluation of [18F]9 in a non-human primate confirmed its superior brain heterogeneity in mapping mGluR2 and higher affinity than [18F]6. Pretreatment with different classes of PAMs in rats and a primate led to similarly enhanced brain uptake of [18F]9. As a selective ligand, [18F]9 has the potential to be developed for translational studies.
Collapse
Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Dalena Huynh
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Suhasini M Iyengar
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Manish Kumar Jain
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Julie E Pickett
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Mary Jo Ondrechen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| |
Collapse
|
5
|
Myslivecek J. Dopamine and Dopamine-Related Ligands Can Bind Not Only to Dopamine Receptors. Life (Basel) 2022; 12:life12050606. [PMID: 35629274 PMCID: PMC9147915 DOI: 10.3390/life12050606] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/11/2022] [Accepted: 04/17/2022] [Indexed: 12/13/2022] Open
Abstract
The dopaminergic system is one of the most important neurotransmitter systems in the central nervous system (CNS). It acts mainly by activation of the D1-like receptor family at the target cell. Additionally, fine-tuning of the signal is achieved via pre-synaptic modulation by the D2-like receptor family. Some dopamine drugs (both agonists and antagonists) bind in addition to DRs also to α2-ARs and 5-HT receptors. Unfortunately, these compounds are often considered subtype(s) specific. Thus, it is important to consider the presence of these receptor subtypes in specific CNS areas as the function virtually elicited by one receptor type could be an effect of other—or the co-effect of multiple receptors. However, there are enough molecules with adequate specificity. In this review, we want to give an overview of the most common off-targets for established dopamine receptor ligands. To give an overall picture, we included a discussion on subtype selectivity. Molecules used as antipsychotic drugs are reviewed too. Therefore, we will summarize reported affinities and give an outline of molecules sufficiently specific for one or more subtypes (i.e., for subfamily), the presence of DR, α2-ARs, and 5-HT receptors in CNS areas, which could help avoid ambiguous results.
Collapse
Affiliation(s)
- Jaromir Myslivecek
- Institute of Physiology, 1st Faculty of Medicine, Charles University, Albertov 5, 128 00 Prague, Czech Republic
| |
Collapse
|
6
|
Employing the Operational Model to Measure System-Independent OTR Efficacy. Methods Mol Biol 2021. [PMID: 34550576 DOI: 10.1007/978-1-0716-1759-5_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Ideally, pharmacological analysis is based on quantitative measurements applied toward unveiling biological mechanisms and guiding medicinal chemistry efforts in drug discovery and basic research. The most robust analysis frameworks generate findings which can be dissociated from the specific experimental setting to provide insights of a broader scope. With insufficient efficacy being the leading cause of drug failures in late-stage clinical trials, more rigorous preclinical definitions might assist in better translation. This chapter details a new method for accessing the Black and Leff operational model of agonism using a stable Flp-In™ T-REx™ HEK293 cell line under tetracycline-dependent control of OTR expression. We cover steps for performing the Gq-coupled HTRF® IP-One assay, curve-fitting data, calculating and statistically representing system-independent drug activity, predicting responses in different sensitivities, and plotting of multivariate analyses.
Collapse
|
7
|
Manning JJ, Green HM, Glass M, Finlay DB. Pharmacological selection of cannabinoid receptor effectors: Signalling, allosteric modulation and bias. Neuropharmacology 2021; 193:108611. [PMID: 34000272 DOI: 10.1016/j.neuropharm.2021.108611] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/26/2021] [Accepted: 05/10/2021] [Indexed: 12/14/2022]
Abstract
The type-1 cannabinoid receptor (CB1) is a promising drug target for a wide range of diseases. However, many existing and novel candidate ligands for CB1 have shown only limited therapeutic potential. Indeed, no ligands are currently approved for the clinic except formulations of the phytocannabinoids Δ9-THC and CBD and a small number of analogues. A key limitation of many promising CB1 ligands are their on-target adverse effects, notably including psychoactivity (agonists) and depression/suicidal ideation (inverse agonists). Recent drug development attempts have therefore focussed on altering CB1 signalling profiles in two ways. Firstly, with compounds that enhance or reduce the signalling of endogenous (endo-) cannabinoids, namely allosteric modulators. Secondly, with compounds that probe the capability of selectively targeting specific cellular signalling pathways that may mediate therapeutic effects using biased ligands. This review will summarise the current paradigm of CB1 signalling in terms of the intracellular transduction pathways acted on by the receptor. The development of compounds that selectively activate CB1 signalling pathways, whether allosterically or via orthosteric agonist bias, will also be addressed.
Collapse
Affiliation(s)
- Jamie J Manning
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand
| | - Hayley M Green
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand.
| |
Collapse
|
8
|
Liu Z, Iyer MR, Godlewski G, Jourdan T, Liu J, Coffey NJ, Zawatsky CN, Puhl HL, Wess J, Meister J, Liow JS, Innis RB, Hassan SA, Lee YS, Kunos G, Cinar R. Functional Selectivity of a Biased Cannabinoid-1 Receptor (CB 1R) Antagonist. ACS Pharmacol Transl Sci 2021; 4:1175-1187. [PMID: 34151207 PMCID: PMC8204328 DOI: 10.1021/acsptsci.1c00048] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Indexed: 12/31/2022]
Abstract
Seven-transmembrane receptors signal via G-protein- and β-arrestin-dependent pathways. We describe a peripheral CB1R antagonist (MRI-1891) highly biased toward inhibiting CB1R-induced β-arrestin-2 (βArr2) recruitment over G-protein activation. In obese wild-type and βArr2-knockout (KO) mice, MRI-1891 treatment reduces food intake and body weight without eliciting anxiety even at a high dose causing partial brain CB1R occupancy. By contrast, the unbiased global CB1R antagonist rimonabant elicits anxiety in both strains, indicating no βArr2 involvement. Interestingly, obesity-induced muscle insulin resistance is improved by MRI-1891 in wild-type but not in βArr2-KO mice. In C2C12 myoblasts, CB1R activation suppresses insulin-induced akt-2 phosphorylation, preventable by MRI-1891, βArr2 knockdown or overexpression of CB1R-interacting protein. MRI-1891, but not rimonabant, interacts with nonpolar residues on the N-terminal loop, including F108, and on transmembrane helix-1, including S123, a combination that facilitates βArr2 bias. Thus, CB1R promotes muscle insulin resistance via βArr2 signaling, selectively mitigated by a biased CB1R antagonist at reduced risk of central nervous system (CNS) side effects.
Collapse
Affiliation(s)
- Ziyi Liu
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Malliga R Iyer
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Grzegorz Godlewski
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Tony Jourdan
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Jie Liu
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Nathan J Coffey
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Charles N Zawatsky
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Henry L Puhl
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Jürgen Wess
- Laboratory of Bioorganic Chemistry, National Institute on Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland 20892-0001, United States
| | - Jaroslawna Meister
- Laboratory of Bioorganic Chemistry, National Institute on Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland 20892-0001, United States
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Sergio A Hassan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Yong Sok Lee
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - George Kunos
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| | - Resat Cinar
- Laboratory of Physiologic Studies and Section on Cellular Biophotonics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-9304, United States
| |
Collapse
|
9
|
Onaran HO, Costa T. Conceptual and experimental issues in biased agonism. Cell Signal 2021; 82:109955. [PMID: 33607257 DOI: 10.1016/j.cellsig.2021.109955] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/20/2021] [Accepted: 02/14/2021] [Indexed: 12/31/2022]
Abstract
In this review, we discuss the theoretical and experimental foundations for assessing agonism in the context of signalling bias in GPCRs. We show that the formulation of efficacy in classical receptor theory and the definition of ligand-induced allosteric effect in chemical thermodynamics are coincident measures of agonism, only if we recognize that the classical model cannot be considered as a mechanistic description of the physicochemical events underlying ligand-receptor signalling. It represents instead a mathematical tool, fortuitously capable of extracting efficacy information from concentration-dependent functional data, where both ligand-dependent and ligand-independent information are present. We also assert that dissecting efficacy from affinity, as originally advocated in classical theory, is imperative for understanding the molecular property underlying agonism, and the biased agonism that leads to preferential formation of diverse GPCR-transducer complexes. Finally, we argue that beyond the assumed translational value of functional selectivity (i.e. signalling bias), the identification of ligands with true bias of efficacy is of fundamental importance for unravelling the conformational space that determines the complex functional chemistry of GPCRs.
Collapse
Affiliation(s)
- H Ongun Onaran
- Ankara University, Faculty of Medicine, Department of Pharmacology, Molecular Biology and Technology Development Unit, Ankara, Turkey.
| | | |
Collapse
|
10
|
Abstract
INTRODUCTION Integrins are a family of 24 cell adhesion receptors that play a role in the biggest unmet needs in medicine - cardiovascular disease, immunology and cancer. Their discovery promised huge potential for the pharmaceutical industry. Areas covered. Over 35-years since their discovery, there is little to show for the hundreds of billions of dollars of investment in anti-integrin drug discovery programmes. In this review the author discusses the reasons for the failure of this promising class of drugs and the future for this class of drugs. Expert opinion. Within 10-years, there was a plethora of potent, specific anti-integrin molecules and since their discovery, many of these agents have entered clinical trials. The success in discovering these agents was due to recently discovered monoclonal antibody technology. The integrin-recognition domain Arg-Gly-Asp (RGD) provided the basis for discovering small molecule inhibitors to integrins - both cyclic peptides and peptidomimetics. Most agents failed in the Phase III clinical trials and those agents that did make it to the market were plagued with issues of toxicity and limited efficacy and were soon replaced with non-integrin targeting agents. Their failure was due to a combination of poor pharmacokinetics and pharmacodynamics, complicated by the complex pathophysiology of integrins.
Collapse
Affiliation(s)
- Dermot Cox
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland , Dublin, Ireland
| |
Collapse
|
11
|
Paton KF, Atigari DV, Kaska S, Prisinzano T, Kivell BM. Strategies for Developing κ Opioid Receptor Agonists for the Treatment of Pain with Fewer Side Effects. J Pharmacol Exp Ther 2020; 375:332-348. [PMID: 32913006 DOI: 10.1124/jpet.120.000134] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/27/2020] [Indexed: 12/21/2022] Open
Abstract
There is significant need to find effective, nonaddictive pain medications. κ Opioid receptor (KOPr) agonists have been studied for decades but have recently received increased attention because of their analgesic effects and lack of abuse potential. However, a range of side effects have limited the clinical development of these drugs. There are several strategies currently used to develop safer and more effective KOPr agonists. These strategies include identifying G-protein-biased agonists, developing peripherally restricted KOPr agonists without centrally mediated side effects, and developing mixed opioid agonists, which target multiple receptors at specific ratios to balance side-effect profiles and reduce tolerance. Here, we review the latest developments in research related to KOPr agonists for the treatment of pain. SIGNIFICANCE STATEMENT: This review discusses strategies for developing safer κ opioid receptor (KOPr) agonists with therapeutic potential for the treatment of pain. Although one strategy is to modify selective KOPr agonists to create peripherally restricted or G-protein-biased structures, another approach is to combine KOPr agonists with μ, δ, or nociceptin opioid receptor activation to obtain mixed opioid receptor agonists, therefore negating the adverse effects and retaining the therapeutic effect.
Collapse
Affiliation(s)
- Kelly F Paton
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand (K.P., D.V.A., B.M.K.) and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky (S.K., T.P.)
| | - Diana V Atigari
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand (K.P., D.V.A., B.M.K.) and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky (S.K., T.P.)
| | - Sophia Kaska
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand (K.P., D.V.A., B.M.K.) and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky (S.K., T.P.)
| | - Thomas Prisinzano
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand (K.P., D.V.A., B.M.K.) and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky (S.K., T.P.)
| | - Bronwyn M Kivell
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand (K.P., D.V.A., B.M.K.) and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky (S.K., T.P.)
| |
Collapse
|
12
|
Gillis A, Sreenivasan V, Christie MJ. Intrinsic Efficacy of Opioid Ligands and Its Importance for Apparent Bias, Operational Analysis, and Therapeutic Window. Mol Pharmacol 2020; 98:410-424. [PMID: 32665252 DOI: 10.1124/mol.119.119214] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 06/25/2020] [Indexed: 12/31/2022] Open
Abstract
Evidence from several novel opioid agonists and knockout animals suggests that improved opioid therapeutic window, notably for analgesia versus respiratory depression, is a result of ligand bias downstream of activation of the µ-opioid receptor (MOR) toward G protein signaling and away from other pathways, such as arrestin recruitment. Here, we argue that published claims of opioid bias based on application of the operational model of agonism are frequently confounded by failure to consider the assumptions of the model. These include failure to account for intrinsic efficacy and ceiling effects in different pathways, distortions introduced by analysis of amplified (G protein) versus linear (arrestin) signaling mechanisms, and nonequilibrium effects in a dynamic signaling cascade. We show on both theoretical and experimental grounds that reduced intrinsic efficacy that is unbiased across different downstream pathways, when analyzed without due considerations, does produce apparent but erroneous MOR ligand bias toward G protein signaling, and the weaker the G protein partial agonism is the greater the apparent bias. Experimentally, such apparently G protein-biased opioids have been shown to exhibit low intrinsic efficacy for G protein signaling when ceiling effects are properly accounted for. Nevertheless, such agonists do display an improved therapeutic window for analgesia versus respiratory depression. Reduced intrinsic efficacy for G proteins rather than any supposed G protein bias provides a more plausible, sufficient explanation for the improved safety. Moreover, genetic models of G protein-biased opioid receptors and replication of previous knockout experiments suggest that reduced or abolished arrestin recruitment does not improve therapeutic window for MOR-induced analgesia versus respiratory depression. SIGNIFICANCE STATEMENT: Efforts to improve safety of µ-opioid analgesics have focused on agonists that show signaling bias for the G protein pathway versus other signaling pathways. This review provides theoretical and experimental evidence showing that failure to consider the assumptions of the operational model can lead to large distortions and overestimation of actual bias. We show that low intrinsic efficacy is a major determinant of these distortions, and pursuit of appropriately reduced intrinsic efficacy should guide development of safer opioids.
Collapse
Affiliation(s)
- Alexander Gillis
- Discipline of Pharmacology, Faculty of Medicine and Health, University of Sydney, New South Wales, Australia (A.G., M.J.C.) and EMBL Australia Node in Single Molecule Science, University of New South Wales, New South Wales, Australia (V.S.)
| | - Varun Sreenivasan
- Discipline of Pharmacology, Faculty of Medicine and Health, University of Sydney, New South Wales, Australia (A.G., M.J.C.) and EMBL Australia Node in Single Molecule Science, University of New South Wales, New South Wales, Australia (V.S.)
| | - Macdonald J Christie
- Discipline of Pharmacology, Faculty of Medicine and Health, University of Sydney, New South Wales, Australia (A.G., M.J.C.) and EMBL Australia Node in Single Molecule Science, University of New South Wales, New South Wales, Australia (V.S.)
| |
Collapse
|
13
|
Gao ZG, Toti KS, Campbell R, Suresh RR, Yang H, Jacobson KA. Allosteric Antagonism of the A 2A Adenosine Receptor by a Series of Bitopic Ligands. Cells 2020; 9:cells9051200. [PMID: 32408534 PMCID: PMC7290864 DOI: 10.3390/cells9051200] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/03/2020] [Accepted: 05/10/2020] [Indexed: 12/11/2022] Open
Abstract
Allosteric antagonism by bitopic ligands, as reported for many receptors, is a distinct modulatory mechanism. Although several bitopic A2A adenosine receptor (A2AAR) ligand classes were reported as pharmacological tools, their receptor binding and functional antagonism patterns, i.e., allosteric or competitive, were not well characterized. Therefore, here we systematically characterized A2AAR binding and functional antagonism of two distinct antagonist chemical classes. i.e., fluorescent conjugates of xanthine amine congener (XAC) and SCH442416. Bitopic ligands were potent, weak, competitive or allosteric, based on the combination of pharmacophore, linker and fluorophore. Among antagonists tested, XAC, XAC245, XAC488, SCH442416, MRS7352 showed Ki binding values consistent with KB values from functional antagonism. Interestingly, MRS7396, XAC-X-BY630 (XAC630) and 5-(N,N-hexamethylene)amiloride (HMA) were 9–100 times weaker in displacing fluorescent MRS7416 binding than radioligand binding. XAC245, XAC630, MRS7396, MRS7416 and MRS7322 behaved as allosteric A2AAR antagonists, whereas XAC488 and MRS7395 antagonized competitively. Schild analysis showed antagonism slopes of 0.42 and 0.47 for MRS7396 and XAC630, respectively. Allosteric antagonists HMA and MRS7396 were more potent in displacing [3H]ZM241385 binding than MRS7416 binding. Sodium site D52N mutation increased and decreased affinity of HMA and MRS7396, respectively, suggesting possible preference for different A2AAR conformations. The allosteric binding properties of some bitopic ligands were rationalized and analyzed using the Hall two-state allosteric model. Thus, fluorophore tethering to an orthosteric ligand is not neutral pharmacologically and may confer unexpected properties to the conjugate.
Collapse
|
14
|
Brust TF. Biased Ligands at the Kappa Opioid Receptor: Fine-Tuning Receptor Pharmacology. Handb Exp Pharmacol 2020; 271:115-135. [PMID: 33140224 DOI: 10.1007/164_2020_395] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The kappa opioid receptor (KOR) is a G protein-coupled receptor (GPCR) that can signal through multiple signaling pathways. KOR agonists are known to relieve pain and itch, as well as induce dysphoria, sedation, hallucinations, and diuresis. As is the case with many other GPCRs, specific signaling pathways downstream of the KOR have been linked to certain physiological responses induced by the receptor. Those studies motivated the search and discovery of a number of KOR ligands that preferentially activate one signaling pathway over another. Such compounds are termed functionally selective or biased ligands, and may present a way of inducing desired receptor effects with reduced adverse reactions. In this chapter, I review the molecular intricacies of KOR signaling and discuss the studies that have used biased signaling through the KOR as a way to selectively modulate in vivo physiology.
Collapse
Affiliation(s)
- Tarsis F Brust
- Department of Pharmaceutical Sciences, Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University, West Palm Beach, FL, USA.
| |
Collapse
|
15
|
G-Protein/Receptor inhibitors as blockers of receptor signaling. J Theor Biol 2019; 480:23-33. [PMID: 31356763 DOI: 10.1016/j.jtbi.2019.07.014] [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: 02/26/2019] [Revised: 07/23/2019] [Accepted: 07/26/2019] [Indexed: 11/23/2022]
Abstract
This paper describes the behavior of binding and functional receptor systems where an antagonist of the receptor/G protein binding reaction is added as a blocker of agonist-induced receptor function. For agonist radioligands, the reduction of G protein receptor interaction leads to a possible change in the binding affinity of the agonist radioligand to the receptor. Reciprocally, the allosteric cooperativity between the agonist and the G protein binding site antagonist (quantified by the factor γB) affects the potency of the G protein antagonist modulator; this model presents the various profiles that would be expected for modulators that reduce (γB = 0.01), have no effect on (γB = 1) and increase (γB = 100) the affinity of the agonist for the receptor. It will be seen that modulators that increase the affinity of the receptor for the agonist are the most potent antagonists and may attain a profile of some special negative allosteric modulators referred to as PAM antagonists. In all cases, these modulators will be inverse agonists of constitutive receptor activity. This model presents a strategy for the discovery of PAM antagonists for therapeutic blockade of physiological signaling.
Collapse
|
16
|
Abstract
Ligand-receptor interactions, which are ubiquitous in physiology, are described by theoretical models of receptor pharmacology. Structural evidence for graded efficacy receptor conformations predicted by receptor theory has been limited but is critical to fully validate theoretical models. We applied quantitative structure-function approaches to characterize the effects of structurally similar and structurally diverse agonists on the conformational ensemble of nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ). For all ligands, agonist functional efficacy is correlated to a shift in the conformational ensemble equilibrium from a ground state toward an active state, which is detected by NMR spectroscopy but not observed in crystal structures. For the structurally similar ligands, ligand potency and affinity are also correlated to efficacy and conformation, indicating ligand residence times among related analogs may influence receptor conformation and function. Our results derived from quantitative graded activity-conformation correlations provide experimental evidence and a platform with which to extend and test theoretical models of receptor pharmacology to more accurately describe and predict ligand-dependent receptor activity.
Collapse
|
17
|
Al-Attraqchi OH, Attimarad M, Venugopala KN, Nair A, Al-Attraqchi NH. Adenosine A2A Receptor as a Potential Drug Target - Current Status and Future Perspectives. Curr Pharm Des 2019; 25:2716-2740. [DOI: 10.2174/1381612825666190716113444] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/03/2019] [Indexed: 12/18/2022]
Abstract
Adenosine receptors (ARs) are a class of G-protein coupled receptors (GPCRs) that are activated by
the endogenous substance adenosine. ARs are classified into 4 subtype receptors, namely, the A1, A2A, A2B and A3
receptors. The wide distribution and expression of the ARs in various body tissues as well as the roles they have
in controlling different functions in the body make them potential drug targets for the treatment of various pathological
conditions, such as cardiac diseases, cancer, Parkinson’s disease, inflammation and glaucoma. Therefore,
in the past decades, there have been extensive investigations of ARs with a high number of agonists and antagonists
identified that can interact with these receptors. This review shall discuss the A2A receptor (A2AAR) subtype
of the ARs. The structure, properties and the recent advances in the therapeutic potential of the receptor are discussed
with an overview of the recent advances in the methods of studying the receptor. Also, molecular modeling
approaches utilized in the design of A2AAR ligands are highlighted with various recent examples.
Collapse
Affiliation(s)
- Omar H.A. Al-Attraqchi
- Faculty of Pharmacy, Philadelphia University-Jordan, P.O BOX (1), Philadelphia University-19392, Amman, Jordan
| | - Mahesh Attimarad
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Katharigatta N. Venugopala
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Anroop Nair
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | | |
Collapse
|
18
|
Mailavaram RP, Al-Attraqchi OH, Kar S, Ghosh S. Current Status in the Design and Development of Agonists and Antagonists of Adenosine A3 Receptor as Potential Therapeutic Agents. Curr Pharm Des 2019; 25:2772-2787. [DOI: 10.2174/1381612825666190716114056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/03/2019] [Indexed: 12/31/2022]
Abstract
Adenosine receptors (ARs) belongs to the family of G-protein coupled receptors (GPCR) that are responsible
for the modulation of a wide variety of physiological functions. The ARs are also implicated in many
diseases such as cancer, arthritis, cardiovascular and renal diseases. The adenosine A3 receptor (A3AR) has
emerged as a potential drug target for the progress of new and effective therapeutic agents for the treatment of
various pathological conditions. This receptor’s involvement in many diseases and its validity as a target has been
established by many studies. Both agonists and antagonists of A3AR have been extensively investigated in the last
decade with the goal of developing novel drugs for treating diseases related to immune disorders, inflammation,
cancer, and others. In this review, we shall focus on the medicinal chemistry of A3AR ligands, exploring the
diverse chemical classes that have been projected as future leading drug candidates. Also, the recent advances in
the therapeuetic applications of A3AR ligands are highlighted.
Collapse
Affiliation(s)
- Raghu P. Mailavaram
- Department of Pharmaceutical Chemistry, Shri Vishnu College of Pharmacy, Vishnupur (Affiliated to Andhra University), Bhimavaram, W.G. Dist., AP, India
| | - Omar H.A. Al-Attraqchi
- Faculty of Pharmacy, Philadelphia University-Jordan, P.O BOX (1), Philadelphia University- 19392, Amman, Jordan
| | - Supratik Kar
- Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, Jackson, MS 39217, United States
| | - Shinjita Ghosh
- School of Public Health, Jackson State University, Jackson, MS 39217, United States
| |
Collapse
|
19
|
Klein Herenbrink C, Verma R, Lim HD, Kopinathan A, Keen A, Shonberg J, Draper-Joyce CJ, Scammells PJ, Christopoulos A, Javitch JA, Capuano B, Shi L, Lane JR. Molecular Determinants of the Intrinsic Efficacy of the Antipsychotic Aripiprazole. ACS Chem Biol 2019; 14:1780-1792. [PMID: 31339684 DOI: 10.1021/acschembio.9b00342] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Partial agonists of the dopamine D2 receptor (D2R) have been developed to treat the symptoms of schizophrenia without causing the side effects elicited by antagonists. The receptor-ligand interactions that determine the intrinsic efficacy of such drugs, however, are poorly understood. Aripiprazole has an extended structure comprising a phenylpiperazine primary pharmacophore and a 1,2,3,4-tetrahydroquinolin-2-one secondary pharmacophore. We combined site-directed mutagenesis, analytical pharmacology, ligand fragments, and molecular dynamics simulations to identify the D2R-aripiprazole interactions that contribute to affinity and efficacy. We reveal that an interaction between the secondary pharmacophore of aripiprazole and a secondary binding pocket defined by residues at the extracellular portions of transmembrane segments 1, 2, and 7 determines the intrinsic efficacy of aripiprazole. Our findings reveal a hitherto unappreciated mechanism for fine-tuning the intrinsic efficacy of D2R agonists.
Collapse
Affiliation(s)
| | - Ravi Verma
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | | | | | | | | | | | | | | | | | | | - Lei Shi
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - J. Robert Lane
- Division of Pharmacology, Physiology and Neuroscience, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham NG7 2UH, U.K
- Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, Nottingham, United Kingdom
| |
Collapse
|
20
|
Makita N, Ando T, Sato J, Manaka K, Mitani K, Kikuchi Y, Niwa T, Ootaki M, Takeba Y, Matsumoto N, Kawakami A, Ogawa T, Nangaku M, Iiri T. Cinacalcet corrects biased allosteric modulation of CaSR by AHH autoantibody. JCI Insight 2019; 4:126449. [PMID: 30996138 DOI: 10.1172/jci.insight.126449] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/12/2019] [Indexed: 12/13/2022] Open
Abstract
Biased agonism is a paradigm that may explain the selective activation of a signaling pathway via a GPCR that activates multiple signals. The autoantibody-induced inactivation of the calcium-sensing receptor (CaSR) causes acquired hypocalciuric hypercalcemia (AHH). Here, we describe an instructive case of AHH in which severe hypercalcemia was accompanied by an increased CaSR antibody titer. These autoantibodies operated as biased allosteric modulators of CaSR by targeting its Venus flytrap domain near the Ca2+-binding site. A positive allosteric modulator of CaSR, cinacalcet, which targets its transmembrane domain, overcame this autoantibody effect and successfully corrected the hypercalcemia in this patient. Hence, this is the first study to our knowledge that identifies the interaction site of a disease-causing GPCR autoantibody working as its biased allosteric modulator and demonstrates that cinacalcet can correct the AHH autoantibody effects both in vitro and in our AHH patient. Our observations provide potentially new insights into how biased agonism works and how to design a biased allosteric modulator of a GPCR. Our observations also indicate that the diagnosis of AHH is important because the severity of hypercalcemia may become fatal if the autoantibody titer increases. Calcimimetics may serve as good treatment options for some patients with severe AHH.
Collapse
Affiliation(s)
- Noriko Makita
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Takao Ando
- Division of Endocrinology and Metabolism, Nagasaki Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Junichiro Sato
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Katsunori Manaka
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Koji Mitani
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Yasuko Kikuchi
- Department of Breast and Endocrine Surgery, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Takayoshi Niwa
- Department of Breast and Endocrine Surgery, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Masanori Ootaki
- Department of Pharmacology, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Yuko Takeba
- Department of Pharmacology, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Naoki Matsumoto
- Department of Pharmacology, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Atsushi Kawakami
- Division of Endocrinology and Metabolism, Nagasaki Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Toshihisa Ogawa
- Breast Center, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan
| | - Masaomi Nangaku
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Taroh Iiri
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan.,Department of Pharmacology, St. Marianna University School of Medicine, Kawasaki, Japan
| |
Collapse
|
21
|
|
22
|
Pasternak GW, Childers SR, Pan YX. Emerging Insights into Mu Opioid Pharmacology. Handb Exp Pharmacol 2019; 258:89-125. [PMID: 31598835 DOI: 10.1007/164_2019_270] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Opioid analgesics, most of which act through mu opioid receptors, have long represented valuable therapeutic agents to treat severe pain. Concerted drug development efforts for over a 100 years have resulted in a large variety of opioid analgesics used in the clinic, but all of them continue to exhibit the side effects, especially respiratory depression, that have long plagued the use of morphine. The recent explosion in fatalities resulting from overdose of prescription and synthetic opioids has dramatically increased the need for safer analgesics, but recent developments in mu receptor research have provided new strategies to develop such drugs. This chapter reviews recent advances in developing novel opioid analgesics from an understanding of mu receptor structure and function. This includes a summary of the mechanism of agonist binding deduced from the crystal structure of mu receptors. It will also highlight the development of novel agonist mechanisms, including biased agonists, bivalent ligands, and allosteric modulators of mu receptor function, and describe how receptor phosphorylation modulates these pathways. Finally, it will summarize research on the alternative pre-mRNA splicing mechanisms that produces a multiplicity of mu receptor isoforms. Many of these isoforms exhibit different pharmacological specificities and brain circuitry localization, thus providing an opportunity to develop novel drugs with increased therapeutic windows.
Collapse
Affiliation(s)
- Gavril W Pasternak
- Department of Neurology and Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Steven R Childers
- Department of Physiology/Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Ying-Xian Pan
- Department of Neurology and Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| |
Collapse
|
23
|
Yunn NO, Kim J, Kim Y, Leibiger I, Berggren PO, Ryu SH. Mechanistic understanding of insulin receptor modulation: Implications for the development of anti-diabetic drugs. Pharmacol Ther 2018; 185:86-98. [DOI: 10.1016/j.pharmthera.2017.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
24
|
Bridge LJ, Mead J, Frattini E, Winfield I, Ladds G. Modelling and simulation of biased agonism dynamics at a G protein-coupled receptor. J Theor Biol 2018; 442:44-65. [PMID: 29337260 PMCID: PMC5811930 DOI: 10.1016/j.jtbi.2018.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 01/08/2018] [Accepted: 01/11/2018] [Indexed: 12/22/2022]
Abstract
Theoretical models of G protein-coupled receptor (GPCR) concentration-response relationships often assume an agonist producing a single functional response via a single active state of the receptor. These models have largely been analysed assuming steady-state conditions. There is now much experimental evidence to suggest that many GPCRs can exist in multiple receptor conformations and elicit numerous functional responses, with ligands having the potential to activate different signalling pathways to varying extents-a concept referred to as biased agonism, functional selectivity or pluri-dimensional efficacy. Moreover, recent experimental results indicate a clear possibility for time-dependent bias, whereby an agonist's bias with respect to different pathways may vary dynamically. Efforts towards understanding the implications of temporal bias by characterising and quantifying ligand effects on multiple pathways will clearly be aided by extending current equilibrium binding and biased activation models to include G protein activation dynamics. Here, we present a new model of time-dependent biased agonism, based on ordinary differential equations for multiple cubic ternary complex activation models with G protein cycle dynamics. This model allows simulation and analysis of multi-pathway activation bias dynamics at a single receptor for the first time, at the level of active G protein (αGTP), towards the analysis of dynamic functional responses. The model is generally applicable to systems with NG G proteins and N* active receptor states. Numerical simulations for NG=N*=2 reveal new insights into the effects of system parameters (including cooperativities, and ligand and receptor concentrations) on bias dynamics, highlighting new phenomena including the dynamic inter-conversion of bias direction. Further, we fit this model to 'wet' experimental data for two competing G proteins (Gi and Gs) that become activated upon stimulation of the adenosine A1 receptor with adenosine derivative compounds. Finally, we show that our model can qualitatively describe the temporal dynamics of this competing G protein activation.
Collapse
Affiliation(s)
- L J Bridge
- Department of Mathematics, Swansea University, Singleton Park, Swansea SA2 8PP, UK; Department of Engineering Design and Mathematics, University of the West of England, Frenchay Campus, Bristol BS16 1QY, UK.
| | - J Mead
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - E Frattini
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - I Winfield
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - G Ladds
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK.
| |
Collapse
|
25
|
O'Brien DE, Shaw DM, Cho HP, Cross AJ, Wesolowski SS, Felts AS, Bergare J, Elmore CS, Lindsley CW, Niswender CM, Conn PJ. Differential Pharmacology and Binding of mGlu 2 Receptor Allosteric Modulators. Mol Pharmacol 2018; 93:526-540. [PMID: 29545267 DOI: 10.1124/mol.117.110114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 03/12/2018] [Indexed: 01/01/2023] Open
Abstract
Allosteric modulation of metabotropic glutamate receptor 2 (mGlu2) has demonstrated efficacy in preclinical rodent models of several brain disorders, leading to industry and academic drug discovery efforts. Although the pharmacology and binding sites of some mGlu2 allosteric modulators have been characterized previously, questions remain about the nature of the allosteric mechanism of cooperativity with glutamate and whether structurally diverse allosteric modulators bind in an identical manner to specific allosteric sites. To further investigate the in vitro pharmacology of mGlu2 allosteric modulators, we developed and characterized a novel mGlu2 positive allosteric modulator (PAM) radioligand in parallel with functional studies of a structurally diverse set of mGlu2 PAMs and negative allosteric modulators (NAMs). Using an operational model of allosterism to analyze the functional data, we found that PAMs affect both the affinity and efficacy of glutamate at mGlu2, whereas NAMs predominantly affect the efficacy of glutamate in our assay system. More importantly, we found that binding of a novel mGlu2 PAM radioligand was inhibited by multiple structurally diverse PAMs and NAMs, indicating that they may bind to the mGlu2 allosteric site labeled with the novel mGlu2 PAM radioligand; however, further studies suggested that these allosteric modulators do not all interact with the radioligand in an identical manner. Together, these findings provide new insights into the binding sites and modes of efficacy of different structurally and functionally distinct mGlu2 allosteric modulators and suggest that different ligands either interact with distinct sites or adapt different binding poses to shared allosteric site(s).
Collapse
Affiliation(s)
- Daniel E O'Brien
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Douglas M Shaw
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Hyekyung P Cho
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Alan J Cross
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Steven S Wesolowski
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Andrew S Felts
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Jonas Bergare
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Charles S Elmore
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery (D.E.O., D.M.S., H.P.C., A.S.F., C.W.L, C.M.N., P.J.C.), Vanderbilt Brain Institute (P.J.C.), and Vanderbilt Kennedy Center (C.M.N., P.J.C.), Vanderbilt University, Nashville, Tennessee; AstraZeneca Neuroscience Innovative Medicines, AstraZeneca, Cambridge, Massachusetts (A.J.C., S.S.W.); and AstraZeneca Pharmaceutical Sciences, AstraZeneca, Mölndal, Sweden (J.B., C.S.E.)
| |
Collapse
|
26
|
Slominski AT, Brożyna AA, Skobowiat C, Zmijewski MA, Kim TK, Janjetovic Z, Oak AS, Jozwicki W, Jetten AM, Mason RS, Elmets C, Li W, Hoffman RM, Tuckey RC. On the role of classical and novel forms of vitamin D in melanoma progression and management. J Steroid Biochem Mol Biol 2018; 177:159-170. [PMID: 28676457 PMCID: PMC5748362 DOI: 10.1016/j.jsbmb.2017.06.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/19/2017] [Accepted: 06/23/2017] [Indexed: 12/31/2022]
Abstract
Melanoma represents a significant clinical problem affecting a large segment of the population with a relatively high incidence and mortality rate. Ultraviolet radiation (UVR) is an important etiological factor in malignant transformation of melanocytes and melanoma development. UVB, while being a full carcinogen in melanomagenesis, is also necessary for the cutaneous production of vitamin D3 (D3). Calcitriol (1,25(OH)2D3) and novel CYP11A1-derived hydroxyderivatives of D3 show anti-melanoma activities and protective properties against damage induced by UVB. The former activities include inhibitory effects on proliferation, plating efficiency and anchorage-independent growth of cultured human and rodent melanomas in vitro, as well as the in vivo inhibition of tumor growth by 20(OH)D3 after injection of human melanoma cells into immunodeficient mice. The literature indicates that low levels of 25(OH)D3 are associated with more advanced melanomas and reduced patient survivals, while single nucleotide polymorphisms of the vitamin D receptor or the D3 binding protein gene affect development or progression of melanoma, or disease outcome. An inverse correlation of VDR and CYP27B1 expression with melanoma progression has been found, with low or undetectable levels of these proteins being associated with poor disease outcomes. Unexpectedly, increased expression of CYP24A1 was associated with better melanoma prognosis. In addition, decreased expression of retinoic acid orphan receptors α and γ, which can also bind vitamin D3 hydroxyderivatives, showed positive association with melanoma progression and shorter disease-free and overall survival. Thus, inadequate levels of biologically active forms of D3 and disturbances in expression of the target receptors, or D3 activating or inactivating enzymes, can affect melanomagenesis and disease progression. We therefore propose that inclusion of vitamin D into melanoma management should be beneficial for patients, at least as an adjuvant approach. The presence of multiple hydroxyderivatives of D3 in skin that show anti-melanoma activity in experimental models and which may act on alternative receptors, will be a future consideration when planning which forms of vitamin D to use for melanoma therapy.
Collapse
Affiliation(s)
- Andrzej T Slominski
- Department of Dermatology, Birmingham, AL, 35294, USA; Comprehensive Cancer Center, Cancer Chemoprevention Program, Birmingham, AL, 35294, USA; Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; VA Medical Center, Birmingham, AL, 35294, USA; Department of Tumor Pathology and Pathomorphology, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz, Poland.
| | - Anna A Brożyna
- Department of Tumor Pathology and Pathomorphology, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz, Poland; Department of Tumor Pathology and Pathomorphology, Faculty of Health Sciences, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland
| | | | | | - Tae-Kang Kim
- Department of Dermatology, Birmingham, AL, 35294, USA
| | | | - Allen S Oak
- Department of Dermatology, Birmingham, AL, 35294, USA
| | - Wojciech Jozwicki
- Department of Tumor Pathology and Pathomorphology, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz, Poland; Department of Tumor Pathology and Pathomorphology, Faculty of Health Sciences, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland
| | - Anton M Jetten
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health,Research Triangle Park, NC 27709, United States
| | - Rebecca S Mason
- Bosch Institute & School of Medical Sciences, Sydney Medical School, The University of Sydney, Sydney, Australia
| | - Craig Elmets
- Department of Dermatology, Birmingham, AL, 35294, USA
| | - We Li
- Department of Pharmaceutical Sciences, University of Tennessee HSC, Memphis, TN 38163, USA
| | - Robert M Hoffman
- AntiCancer, Inc., San Diego, CA, USA; Department of Surgery, University of California, San Diego, CA, USA
| | - Robert C Tuckey
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| |
Collapse
|
27
|
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.
Collapse
Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| |
Collapse
|
28
|
Slominski AT, Kim TK, Hobrath JV, Oak ASW, Tang EKY, Tieu EW, Li W, Tuckey RC, Jetten AM. Endogenously produced nonclassical vitamin D hydroxy-metabolites act as "biased" agonists on VDR and inverse agonists on RORα and RORγ. J Steroid Biochem Mol Biol 2017; 173:42-56. [PMID: 27693422 PMCID: PMC5373926 DOI: 10.1016/j.jsbmb.2016.09.024] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/17/2016] [Accepted: 09/28/2016] [Indexed: 02/07/2023]
Abstract
The classical pathway of vitamin D activation follows the sequence D3→25(OH)D3→1,25(OH)2D3 with the final product acting on the receptor for vitamin D (VDR). An alternative pathway can be started by the action of CYP11A1 on the side chain of D3, primarily producing 20(OH)D3, 22(OH)D3, 20,23(OH)2D3, 20,22(OH)2D3 and 17,20,23(OH)3D3. Some of these metabolites are hydroxylated by CYP27B1 at C1α, by CYP24A1 at C24 and C25, and by CYP27A1 at C25 and C26. The products of these pathways are biologically active. In the epidermis and/or serum or adrenals we detected 20(OH)D3, 22(OH)D3, 20,22(OH)2D3, 20,23(OH)2D3, 17,20,23(OH)3D3, 1,20(OH)2D3, 1,20,23(OH)3D3, 1,20,22(OH)3D3, 20,24(OH)2D3, 1,20,24(OH)3D3, 20,25(OH)2D3, 1,20,25(OH)3D3, 20,26(OH)2D3 and 1,20,26(OH)3D3. 20(OH)D3 and 20,23(OH)2D3 are non-calcemic, while the addition of an OH at C1α confers some calcemic activity. Molecular modeling and functional assays show that the major products of the pathway can act as "biased" agonists for the VDR with high docking scores to the ligand binding domain (LBD), but lower than that of 1,25(OH)2D3. Importantly, cell based functional receptor studies and molecular modeling have identified the novel secosteroids as inverse agonists of both RORα and RORγ receptors. Specifically, they have high docking scores using crystal structures of RORα and RORγ LBDs. Furthermore, 20(OH)D3 and 20,23(OH)2D3 have been tested in a cell model that expresses a Tet-on RORα or RORγ vector and a RORE-LUC reporter (ROR-responsive element), and in a mammalian 2-hybrid model that test interactions between an LBD-interacting LXXLL-peptide and the LBD of RORα/γ. These assays demonstrated that the novel secosteroids have ROR-antagonist activities that were further confirmed by the inhibition of IL17 promoter activity in cells overexpressing RORα/γ. In conclusion, endogenously produced novel D3 hydroxy-derivatives can act both as "biased" agonists of the VDR and/or inverse agonists of RORα/γ. We suggest that the identification of large number of endogenously produced alternative hydroxy-metabolites of D3 that are biologically active, and of possible alternative receptors, may offer an explanation for the pleiotropic and diverse activities of vitamin D, previously assigned solely to 1,25(OH)2D3 and VDR.
Collapse
MESH Headings
- Animals
- Cholesterol Side-Chain Cleavage Enzyme/metabolism
- Humans
- Hydroxycholecalciferols/metabolism
- Hydroxycholecalciferols/pharmacology
- Models, Molecular
- Nuclear Receptor Subfamily 1, Group F, Member 1/agonists
- Nuclear Receptor Subfamily 1, Group F, Member 1/metabolism
- Nuclear Receptor Subfamily 1, Group F, Member 3/agonists
- Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism
- Receptors, Calcitriol/agonists
- Receptors, Calcitriol/metabolism
- Vitamins/metabolism
- Vitamins/pharmacology
Collapse
Affiliation(s)
- Andrzej T Slominski
- Department of Dermatology, USA; Comprehensive Cancer Center, Cancer Chemoprevention Program, University of Alabama at Birmingham, USA; Pathology and Laboratory Medicine Service, VA Medical Center, Birmingham, AL, 35249, USA.
| | | | - Judith V Hobrath
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom
| | | | - Edith K Y Tang
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA, Australia
| | - Elaine W Tieu
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA, Australia
| | - Wei Li
- Department of Pharmaceutical Sciences University of Tennessee HSC, Memphis, TN 38163, USA
| | - Robert C Tuckey
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA, Australia
| | - Anton M Jetten
- Cell Biology Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| |
Collapse
|
29
|
Gao ZG, Jacobson KA. Distinct Signaling Patterns of Allosteric Antagonism at the P2Y 1 Receptor. Mol Pharmacol 2017; 92:613-626. [PMID: 28864555 DOI: 10.1124/mol.117.109660] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 08/30/2017] [Indexed: 12/18/2022] Open
Abstract
Traditionally, G protein-coupled receptor antagonists are classified as competitive or noncompetitive and surmountable or insurmountable based on functional antagonism. P2Y1 receptor (P2Y1R) structures showed two antagonists binding to two spatially distinct sites: nucleotide MRS2500 (orthosteric, contacting the helical bundle) and urea BPTU (allosteric, on the external receptor surface). However, the nature of their P2Y1R antagonism has not been characterized. Here we characterized BPTU antagonism at various signaling pathways activated by structurally diverse agonists. BPTU rightward shifted the concentration-response curves of both 2-methylthioadenosine 5'-diphosphate trisodium salt and MRS2365 (5'-diphosphates) in some signaling events, such as extracellular signal-regulated kinase 1/2 and label free, in a parallel manner without affecting the maximum agonist effect (Emax) but antagonized insurmountably (suppressed agonist Emax) in signaling events such as guanosine 5'-3-O-(thio)triphosphate binding and β-arrestin2 recruitment. However, with dinucleotide Ap4A as an agonist, BPTU suppressed the Emax insurmountably in all signaling pathways. By comparison, MRS2500 behaved as surmountable antagonist rightward-shifting concentration-response curves of all three agonists in a parallel manner for all signaling pathways measured. Thus, we demonstrated a previously undocumented phenomenon that P2Y1R antagonism patterns could vary in different signaling pathways, which could be related to conformational selection, signaling amplification, and probe dependence. This phenomenon may apply generally to other receptors considering that antagonism by a specific ligand is often not compared at multiple signaling pathways. Thus, antagonism can be surmountable or insurmountable depending on the signaling pathways measured and the agonists used, which should be of broad relevance to drug discovery and disease treatment.
Collapse
Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
30
|
Abstract
Orexin/hypocretin peptide (orexin-A and orexin-B) signaling is believed to take place via the two G-protein-coupled receptors (GPCRs), named OX1 and OX2 orexin receptors, as described in the previous chapters. Signaling of orexin peptides has been investigated in diverse endogenously orexin receptor-expressing cells - mainly neurons but also other types of cells - and in recombinant cells expressing the receptors in a heterologous manner. Findings in the different systems are partially convergent but also indicate cellular background-specific signaling. The general picture suggests an inherently high degree of diversity in orexin receptor signaling.In the current chapter, I present orexin signaling on the cellular and molecular levels. Discussion of the connection to (potential) physiological orexin responses is only brief since these are in focus of other chapters in this book. The same goes for the post-synaptic signaling mechanisms, which are dealt with in Burdakov: Postsynaptic actions of orexin. The current chapter is organized according to the tissue type, starting from the central nervous system. Finally, receptor signaling pathways are discussed across tissues, cell types, and even species.
Collapse
Affiliation(s)
- Jyrki P Kukkonen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, POB 66, FIN-00014, Helsinki, Finland.
| |
Collapse
|
31
|
Gamage TF, Farquhar CE, Lefever TW, Thomas BF, Nguyen T, Zhang Y, Wiley JL. The great divide: Separation between in vitro and in vivo effects of PSNCBAM-based CB 1 receptor allosteric modulators. Neuropharmacology 2017; 125:365-375. [PMID: 28803965 DOI: 10.1016/j.neuropharm.2017.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/25/2017] [Accepted: 08/09/2017] [Indexed: 01/08/2023]
Abstract
While allosteric modulators of the cannabinoid type-1 receptor (CB1) continue to be developed and characterized, the gap between the in vitro and in vivo data is widening, raising questions regarding translatability of their effects and biological relevance. Among the CB1 allosteric modulators, PSNCBAM-1 has received little attention regarding its effects in vivo. Recently, pregnenolone was reported to act as an allosteric modulator of CB1, blocking THC's effects in vitro and in vivo, highlighting the potential of CB1 allosteric modulators for treatment of cannabis intoxication. We investigated the pharmacological effects of PSNCBAM-1 and two structural analogs, RTICBM-15 and -28, as well as pregnenolone, in both signaling and behavioral assays including [35S]GTPγS binding, the cannabinoid tetrad and drug discrimination. While the CB1 allosteric modulator PSNCBAM-1 attenuated THC-induced anti-nociception and its structural analog RTICBM-28 reduced THC's potency in drug discrimination, most cannabinoid effects in mice were unaffected. In contrast to the mouse studies, PSNCBAM-1 and analogs insurmountably antagonized CP55,940- and THC-stimulated [35S]GTPγS binding and exhibited negative binding cooperativity with [3H]SR141716 with similar apparent affinities. Notably, RTICBM-28, which contains a cyano substitution at the 4-chlorophenyl position of PSNCBAM-1, exhibited enhanced binding cooperativity with CP55,940. In contrast to previous findings, pregnenolone did not block THC's effects in drug discrimination or [35S]GTPγS. These data further highlight the difficulty in translating pharmacological effects of CB1 allosteric modulators in vivo but confirm the established pharmacology of PSNCBAM-1 and analogs in molecular assays of CB1 receptor function.
Collapse
Affiliation(s)
- Thomas F Gamage
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA.
| | - Charlotte E Farquhar
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| | - Timothy W Lefever
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| | - Brian F Thomas
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| | - Thuy Nguyen
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| | - Yanan Zhang
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| | - Jenny L Wiley
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| |
Collapse
|
32
|
Abstract
G-protein-coupled receptors (GPCRs) constitute a large group of integral membrane proteins that transduce extracellular signals from a wide range of agonists into targeted intracellular responses. Although the responses can vary depending on the category of G-proteins activated by a particular receptor, responses were also found to be triggered by interactions of the receptor with β-arrestins. It was subsequently discovered that for the same receptor molecule (e.g., the β-adrenergic receptor), some agonists have a propensity to specifically favor responses by G-proteins, others by β-arrestins, as has now been extensively studied. This feature of the GPCR system is known as biased agonism and is subject to various interpretations, including agonist-induced conformational change versus selective stabilization of preexisting active conformations. Here, we explore a complete allosteric framework for biased agonism based on alternative preexisting conformations that bind more strongly, but nonexclusively, either G-proteins or β-arrestins. The framework incorporates reciprocal effects among all interacting molecules. As a result, G-proteins and β-arrestins are in steric competition for binding to the cytoplasmic surface of either the G-protein-favoring or β-arrestin-favoring GPCR conformation. Moreover, through linkage relations, the strength of the interactions of G-proteins or β-arrestins with the corresponding active conformation potentiates the apparent affinity for the agonist, effectively equating these two proteins to allosteric modulators. The balance between response alternatives can also be influenced by the physiological concentrations of either G-proteins or β-arrestins, as well as by phosphorylation or interactions with positive or negative allosteric modulators. The nature of the interactions in the simulations presented suggests novel experimental tests to distinguish more fully among alternative mechanisms.
Collapse
|
33
|
Truong PM, Hassan SA, Lee YS, Kopajtic TA, Katz JL, Chadderdon AM, Traynor JR, Deschamps JR, Jacobson AE, Rice KC. Modulation of opioid receptor affinity and efficacy via N-substitution of 9β-hydroxy-5-(3-hydroxyphenyl)morphan: Synthesis and computer simulation study. Bioorg Med Chem 2017; 25:2406-2422. [PMID: 28314512 PMCID: PMC5407189 DOI: 10.1016/j.bmc.2017.02.064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/27/2017] [Indexed: 10/20/2022]
Abstract
The enantiomers of a variety of N-alkyl-, N-aralkyl-, and N-cyclopropylalkyl-9β-hydroxy-5-(3-hydroxyphenyl)morphans were synthesized employing cyanogen bromide and K2CO3 to improve the original N-demethylation procedure. Their binding affinity to the μ-, δ-, and κ-opioid receptors (ORs) was determined and functional (GTPγ35S) assays were carried out on those with reasonable affinity. The 1R,5R,9S-enantiomers (1R,5R,9S)-(-)-5-(3-hydroxyphenyl)-2-(4-nitrophenethyl)-2-azabicyclo[3.3.1]nonan-9-ol (1R,5R,9S-16), (1R,5R,9S)-(-) 2-cinnamyl-5-(3-hydroxyphenyl)-2-azabicyclo[3.3.1]nonan-9-ol (1R,5R,9S-20), and (1R,5R,9S)-(-)-5-(3-hydroxyphenyl)-2-(4-(trifluoromethyl)phenethyl)-2-azabicyclo[3.3.1]nonan-9-ol (1R,5R,9S-15), had high affinity for the μ-opioid receptor (e.g., 1R,5R,9S-16: Ki=0.073, 0.74, and 1.99nM, respectively). The 1R,5R,9S-16 and 1R,5R,9S-15 were full, high efficacy μ-agonists (EC50=0.74 and 18.5nM, respectively) and the former was found to be a partial agonist at δ-OR and an antagonist at κ-OR, while the latter was a partial agonist at δ-OR and κ-OR in the GTPγ35S assay. The enantiomer of 1R,5R,9S-16, (+)-1S,5S,9R-16 was unusual, it had good affinity for the μ-OR (Ki=26.5nM) and was an efficacious μ-antagonist (Ke=29.1nM). Molecular dynamics simulations of the μ-OR were carried out with the 1R,5R,9S-16 μ-agonist and the previously synthesized (1R,5R,9S)-(-)-5-(9-hydroxy-5-(3-hydroxyphenyl-2-phenylethyl)-2-azabicyclo[3.3.1]nonane (1R,5R,9S-(-)-NIH 11289) to provide a structural basis for the observed high affinities and efficacies. The critical roles of both the 9β-OH and the p-nitro group are elucidated, with the latter forming direct, persistent hydrogen bonds with residues deep in the binding cavity, and the former interacting with specific residues via highly structured water bridges.
Collapse
Affiliation(s)
- Phong M Truong
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, United States
| | - Sergio A Hassan
- Center for Molecular Modeling, Office of Intramural Research, Center for Information Technology, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Yong-Sok Lee
- Center for Molecular Modeling, Office of Intramural Research, Center for Information Technology, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Theresa A Kopajtic
- Psychobiology Section, Molecular Neuropsychiatry Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, United States
| | - Jonathan L Katz
- Psychobiology Section, Molecular Neuropsychiatry Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, United States
| | - Aaron M Chadderdon
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - John R Traynor
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Jeffrey R Deschamps
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington DC 20375, United States
| | - Arthur E Jacobson
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, United States
| | - Kenner C Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, United States.
| |
Collapse
|
34
|
Abstract
INTRODUCTION The availability of different functional pharmacological assays has revealed that agonists for receptors that are pleiotropically coupled to multiple signaling pathways in the cell can emphasize signals to some pathways over others, i.e. can be biased toward certain signals. This, in turn, opens the possibility that molecules can be made to emphasize favorable signals, de-emphasize harmful signals or selectively block the ability of the natural agonist to produce unfavorable signals. Areas covered: This paper discusses the mechanism of biased signaling, the possible therapeutic implications of this effect, methods to quantify and measure bias and the current literature describing the translation of biased measure in vitro to in vivo systems. In addition, the challenges of exploiting this mechanism for therapy are outlined. Expert opinion: While this mechanism is well established and ubiquitous in pharmacology and easily measured in vitro, there are theoretical and practical hurdles to overcome to the fruitful utilization of signaling bias in therapeutic systems. There will be failures in the translation of biased molecules in vivo because of these challenges but hopefully also success and these latter translations hopefully will provide guidance in exploiting this effect further for therapy.
Collapse
Affiliation(s)
- Terry Kenakin
- a Department of Pharmacology , University of North Carolina School of Medicine , Chapel Hill , NC , USA
| |
Collapse
|
35
|
Wong B, Perkins MW, Tressler J, Rodriguez A, Devorak J, Sciuto AM. Effects of inhaled aerosolized carfentanil on real-time physiological responses in mice: a preliminary evaluation of naloxone. Inhal Toxicol 2017; 29:65-74. [DOI: 10.1080/08958378.2017.1282065] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Benjamin Wong
- Biochemistry and Toxicology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| | - Michael W. Perkins
- Biochemistry and Toxicology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| | - Justin Tressler
- Biochemistry and Toxicology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| | - Ashley Rodriguez
- Biochemistry and Toxicology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| | - Jennifer Devorak
- Biochemistry and Toxicology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| | - Alfred M. Sciuto
- Biochemistry and Toxicology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| |
Collapse
|
36
|
Wiley JL, Marusich JA, Thomas BF. Combination Chemistry: Structure-Activity Relationships of Novel Psychoactive Cannabinoids. Curr Top Behav Neurosci 2017; 32:231-248. [PMID: 27753007 DOI: 10.1007/7854_2016_17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Originally developed as research tools for use in structure-activity relationship studies, synthetic cannabinoids contributed to significant scientific advances in the cannabinoid field. Unfortunately, a subset of these compounds was diverted for recreational use beginning in the early 2000s. As these compounds were banned, they were replaced with additional synthetic cannabinoids with increasingly diverse chemical structures. This chapter focuses on integration of recent results with those covered in previous reviews. Whereas most of the early compounds were derived from the prototypic naphthoylindole JWH-018, currently popular synthetic cannabinoids include tetramethylcyclopropyl ketones and indazole-derived cannabinoids (e.g., AB-PINACA, AB-CHMINACA). Despite their structural differences, psychoactive synthetic cannabinoids bind with high affinity to CB1 receptors in the brain and, when tested, have been shown to activate these receptors and to produce a characteristic profile of effects, including suppression of locomotor activity, antinociception, hypothermia, and catalepsy, as well as Δ9-tetrahydrocannabinol (THC)-like discriminative stimulus effects in mice. When they have been tested, synthetic cannabinoids are often found to be more efficacious at activation of the CB1 receptor and more potent in vivo. Further, their chemical alteration by thermolysis during use and their uncertain stability and purity may result in exposure to degradants that differ from the parent compound contained in the original product. Consequently, while their intoxicant effects may be similar to those of THC, use of synthetic cannabinoids may be accompanied by unpredicted, and sometimes harmful, effects.
Collapse
Affiliation(s)
- Jenny L Wiley
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC, 27709-2194, USA.
| | - Julie A Marusich
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC, 27709-2194, USA
| | - Brian F Thomas
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC, 27709-2194, USA
| |
Collapse
|
37
|
Varano F, Catarzi D, Vincenzi F, Betti M, Falsini M, Ravani A, Borea PA, Colotta V, Varani K. Design, Synthesis, and Pharmacological Characterization of 2-(2-Furanyl)thiazolo[5,4-d]pyrimidine-5,7-diamine Derivatives: New Highly Potent A 2A Adenosine Receptor Inverse Agonists with Antinociceptive Activity. J Med Chem 2016; 59:10564-10576. [PMID: 27933962 DOI: 10.1021/acs.jmedchem.6b01068] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In this study, we describe the design and synthesis of new N5-substituted-2-(2-furanyl) thiazolo[5,4-d]pyrimidine-5,7-diamines (2-18) and their pharmacological characterization as A2A adenosine receptor (AR) antagonists by using in vitro and in vivo assays. In competition binding experiments two derivatives (13 and 14) emerged as outstanding ligands showing two different affinity values (KH and KL) for the hA2A receptor with the high affinity KH value in the femtomolar range. The in vitro functional activity assays, performed by using cyclic AMP experiments, assessed that they behave as potent inverse agonists at the hA2A AR. Compounds 13 and 14 were evaluated for their antinociceptive activity in acute experimental models of pain showing an effect equal to or greater than that of morphine. Overall, these novel inverse agonists might represent potential drug candidates for an alternative approach to the management of pain.
Collapse
Affiliation(s)
- Flavia Varano
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze , via Ugo Schiff, 6, 50019, Sesto Fiorentino, Italy
| | - Daniela Catarzi
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze , via Ugo Schiff, 6, 50019, Sesto Fiorentino, Italy
| | - Fabrizio Vincenzi
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università degli Studi di Ferrara , via Fossato di Mortara 17-19, 44121, Ferrara, Italy
| | - Marco Betti
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze , via Ugo Schiff, 6, 50019, Sesto Fiorentino, Italy
| | - Matteo Falsini
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze , via Ugo Schiff, 6, 50019, Sesto Fiorentino, Italy
| | - Annalisa Ravani
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università degli Studi di Ferrara , via Fossato di Mortara 17-19, 44121, Ferrara, Italy
| | - Pier Andrea Borea
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università degli Studi di Ferrara , via Fossato di Mortara 17-19, 44121, Ferrara, Italy
| | - Vittoria Colotta
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze , via Ugo Schiff, 6, 50019, Sesto Fiorentino, Italy
| | - Katia Varani
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università degli Studi di Ferrara , via Fossato di Mortara 17-19, 44121, Ferrara, Italy
| |
Collapse
|
38
|
Costa-Neto CM, Parreiras-E-Silva LT, Bouvier M. A Pluridimensional View of Biased Agonism. Mol Pharmacol 2016; 90:587-595. [PMID: 27638872 DOI: 10.1124/mol.116.105940] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 09/14/2016] [Indexed: 12/17/2022] Open
Abstract
When studying G protein-coupled receptor (GPCR) signaling and ligand-biased agonism, at least three dimensional spaces must be considered, as follows: 1) the distinct conformations that can be stabilized by different ligands promoting the engagement of different signaling effectors and accessory regulators; 2) the distinct subcellular trafficking that can be conferred by different ligands, which results in spatially distinct signals; and 3) the differential binding kinetics that maintain the receptor in specific conformation and/or subcellular localization for different periods of time, allowing for the engagement of distinct signaling effector subsets. These three pluridimensional aspects of signaling contribute to different faces of functional selectivity and provide a complex, interconnected way to define the signaling profile of each individual ligand acting at GPCRs. In this review, we discuss how each of these aspects may contribute to the diversity of signaling, but also how they shed light on the complexity of data analyses and interpretation. The impact of phenotype variability as a source of signaling diversity, and the influence of novel and more sensitive assays in the detection and analysis of signaling pluridimensionality, is also discussed. Finally, we discuss perspectives for the use of the concept of pluridimensional signaling in drug discovery, in which we highlight future predictive tools that may facilitate the identification of compounds with optimal therapeutic and safety properties based on the signaling signatures of drug candidates.
Collapse
Affiliation(s)
- Claudio M Costa-Neto
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, Brazil (C.M.C.-N., L.T.P.-S.); and Department of Biochemistry and Molecular Medicine and Institute for Research in Immunology and Cancer, University of Montréal, Montréal, Canada (L.T.P.-S., M.B.)
| | - Lucas T Parreiras-E-Silva
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, Brazil (C.M.C.-N., L.T.P.-S.); and Department of Biochemistry and Molecular Medicine and Institute for Research in Immunology and Cancer, University of Montréal, Montréal, Canada (L.T.P.-S., M.B.)
| | - Michel Bouvier
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, Brazil (C.M.C.-N., L.T.P.-S.); and Department of Biochemistry and Molecular Medicine and Institute for Research in Immunology and Cancer, University of Montréal, Montréal, Canada (L.T.P.-S., M.B.)
| |
Collapse
|
39
|
Dalwadi DA, Kim S, Amdani SM, Chen Z, Huang RQ, Schetz JA. Molecular mechanisms of serotonergic action of the HIV-1 antiretroviral efavirenz. Pharmacol Res 2016; 110:10-24. [PMID: 27157251 DOI: 10.1016/j.phrs.2016.04.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/14/2016] [Accepted: 04/28/2016] [Indexed: 02/04/2023]
Abstract
Efavirenz is highly effective at suppressing HIV-1, and the WHO guidelines list it as a component of the first-line antiretroviral (ARV) therapies for treatment-naïve patients. Though the pharmacological basis is unclear, efavirenz is commonly associated with a risk for neuropsychiatric adverse events (NPAEs) when taken at the prescribed dose. In many patients these NPAEs appear to subside after several weeks of treatment, though long-term studies show that in some patients the NPAEs persist. In a recent study focusing on the abuse potential of efavirenz, its receptor psychopharmacology was reported to include interactions with a number of established molecular targets for known drugs of abuse, and it displayed a prevailing behavioral profile in rodents resembling an LSD-like activity. In this report, we discovered interactions with additional serotonergic targets that may be associated with efavirenz-induced NPAEs. The most robust interactions were with 5-HT3A and 5-HT6 receptors, with more modest interactions noted for the 5-HT2B receptor and monoamine oxidase A. From a molecular mechanistic perspective, efavirenz acts as a 5-HT6 receptor inverse agonist of Gs-signaling, 5-HT2A and 5-HT2C antagonist of Gq-signaling, and a blocker of the 5-HT3A receptor currents. Efavirenz also completely or partially blocks agonist stimulation of the M1 and M3 muscarinic receptors, respectively. Schild analysis suggests that efavirenz competes for the same site on the 5-HT2A receptor as two known hallucinogenic partial agonists (±)-DOI and LSD. Prolonged exposure to efavirenz reduces 5-HT2A receptor density and responsiveness to 5-HT. Other ARVs such as zidovudine, nevirapine and emtricitabine did not share the same complex pharmacological profile as efavirenz, though some of them weakly interact with the 5-HT6 receptor or modestly block GABAA currents.
Collapse
Affiliation(s)
- Dhwanil A Dalwadi
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Seongcheol Kim
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Shahnawaz M Amdani
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Zhenglan Chen
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Ren-Qi Huang
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States; Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - John A Schetz
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States; Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States.
| |
Collapse
|
40
|
Iglesias A, Lage S, Cadavid MI, Loza MI, Brea J. Development of a Multiplex Assay for Studying Functional Selectivity of Human Serotonin 5-HT2A Receptors and Identification of Active Compounds by High-Throughput Screening. ACTA ACUST UNITED AC 2016; 21:816-23. [PMID: 27095818 DOI: 10.1177/1087057116644162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/21/2016] [Indexed: 11/17/2022]
Abstract
G protein-coupled receptors (GPCRs) exist as collections of conformations in equilibrium, and the efficacy of drugs has been proposed to be associated with their absolute and relative affinities for these different conformations. The serotonin 2A (5-HT2A) receptor regulates multiple physiological functions, is involved in the pathophysiology of schizophrenia, and serves as an important target of atypical antipsychotic drugs. This receptor was one of the first GPCRs for which the functional selectivity phenomenon was observed, with its various ligands exerting differential effects on the phospholipase A2 (PLA2) and phospholipase C (PLC) signaling pathways. We aimed to develop a multiplex functional assay in 96-well plates for the simultaneous measurement of the PLA2 and PLC pathways coupled to 5-HT2A receptors; this approach enables the detection of either functional selectivity or cooperativity phenomena in early drug screening stages. The suitability of the method for running screening campaigns was tested using the Prestwick Chemical Library, and 22 confirmed hits with activities of more than 90% were identified; 11 of these hits produced statistically significant differences between the two effector pathways. Thus, we have developed a miniaturized multiplex assay in 96-well plates to measure functional selectivity for 5-HT2A receptors in the early stages of the drug discovery process.
Collapse
Affiliation(s)
- Alba Iglesias
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Sonia Lage
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Maria Isabel Cadavid
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Maria Isabel Loza
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - José Brea
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| |
Collapse
|
41
|
Maguire JJ. Evidence for biased agonists and antagonists at the endothelin receptors. Life Sci 2016; 159:30-33. [PMID: 26898124 PMCID: PMC5000545 DOI: 10.1016/j.lfs.2016.02.069] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/22/2016] [Accepted: 02/16/2016] [Indexed: 01/08/2023]
Abstract
Biased ligands represent a new strategy for the development of more effective and better tolerated drugs. To date there has been a paucity of research exploring the potential of ligands that exhibit either G protein or β-arrestin pathway selectivity at the endothelin receptors. Re-analysis of data may allow researchers to determine whether there is existing evidence that the endogenous ET peptides or currently available agonists and antagonists exhibit pathway bias in a particular physiological or disease setting and this is explored in the review. An alternative to molecules that bind at the orthosteric site of the ET receptors are cell penetrating peptides that interact with a segment of an intracellular loop of the receptor to modify signalling behaviour. One such peptide IC2B has been shown to have efficacy in a model of pulmonary arterial hypertension. Finally, understanding the molecular pathways that contribute to disease is critical to determining whether biased ligands will provide clinical benefit. The role of ETA signalling in ovarian cancer has been delineated in some detail and this has led to the suggestion that the development of ETA G protein biased agonists or β-arrestin biased antagonists should be explored.
Collapse
Affiliation(s)
- Janet J Maguire
- Experimental Medicine and Immunotherapeutics, Level 6 ACCI, Box 110 Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
| |
Collapse
|
42
|
Unravelling intrinsic efficacy and ligand bias at G protein coupled receptors: A practical guide to assessing functional data. Biochem Pharmacol 2016; 101:1-12. [DOI: 10.1016/j.bcp.2015.10.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/12/2015] [Indexed: 01/17/2023]
|
43
|
Riddy DM, Valant C, Rueda P, Charman WN, Sexton PM, Summers RJ, Christopoulos A, Langmead CJ. Label-Free Kinetics: Exploiting Functional Hemi-Equilibrium to Derive Rate Constants for Muscarinic Receptor Antagonists. Mol Pharmacol 2015; 88:779-90. [DOI: 10.1124/mol.115.100545] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 08/03/2015] [Indexed: 01/14/2023] Open
|
44
|
Boitano S, Hoffman J, Flynn AN, Asiedu MN, Tillu DV, Zhang Z, Sherwood CL, Rivas CM, DeFea KA, Vagner J, Price TJ. The novel PAR2 ligand C391 blocks multiple PAR2 signalling pathways in vitro and in vivo. Br J Pharmacol 2015; 172:4535-4545. [PMID: 26140338 DOI: 10.1111/bph.13238] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 06/18/2015] [Accepted: 06/28/2015] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Proteinase-activated receptor-2 (PAR2) is a GPCR linked to diverse pathologies, including acute and chronic pain. PAR2 is one of the four PARs that are activated by proteolytic cleavage of the extracellular amino terminus, resulting in an exposed, tethered peptide agonist. Several peptide and peptidomimetic agonists, with high potency and efficacy, have been developed to probe the functions of PAR2, in vitro and in vivo. However, few similarly potent and effective antagonists have been described. EXPERIMENTAL APPROACH We modified the peptidomimetic PAR2 agonist, 2-furoyl-LIGRLO-NH2 , to create a novel PAR2 peptidomimetic ligand, C391. C391 was evaluated for PAR2 agonist/antagonist activity to PAR2 across Gq signalling pathways using the naturally expressing PAR2 cell line 16HBE14o-. For antagonist studies, a highly potent and specific peptidomimetic agonist (2-aminothiazo-4-yl-LIGRL-NH2 ) and proteinase agonist (trypsin) were used to activate PAR2. C391 was also evaluated in vivo for reduction of thermal hyperalgesia, mediated by mast cell degranulation, in mice. KEY RESULTS C391 is a potent and specific peptidomimetic antagonist, blocking multiple signalling pathways (Gq -dependent Ca2+ , MAPK) induced following peptidomimetic or proteinase activation of human PAR2. In a PAR2-dependent behavioural assay in mice, C391 dose-dependently (75 μg maximum effect) blocked the thermal hyperalgesia, mediated by mast cell degranulation. CONCLUSIONS AND IMPLICATIONS C391 is the first low MW antagonist to block both PAR2 Ca2+ and MAPK signalling pathways activated by peptidomimetics and/or proteinase activation. C391 represents a new molecular structure for PAR2 antagonism and can serve as a basis for further development for this important therapeutic target.
Collapse
Affiliation(s)
- Scott Boitano
- Arizona Respiratory Center and Department of Physiology, University of Arizona, Tucson, AZ, USA.,The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA
| | - Justin Hoffman
- Arizona Respiratory Center and Department of Physiology, University of Arizona, Tucson, AZ, USA.,The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA
| | - Andrea N Flynn
- Arizona Respiratory Center and Department of Physiology, University of Arizona, Tucson, AZ, USA.,The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA
| | - Marina N Asiedu
- Department of Pharmacology, University of Arizona, Tucson, AZ, USA
| | - Dipti V Tillu
- Department of Pharmacology, University of Arizona, Tucson, AZ, USA
| | - Zhenyu Zhang
- The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA
| | - Cara L Sherwood
- Arizona Respiratory Center and Department of Physiology, University of Arizona, Tucson, AZ, USA.,The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA
| | - Candy M Rivas
- Arizona Respiratory Center and Department of Physiology, University of Arizona, Tucson, AZ, USA.,The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Physiological Sciences, University of Arizona, Tucson, AZ, USA
| | - Kathryn A DeFea
- Biomedical Sciences Division, University of California, Riverside, CA, USA
| | - Josef Vagner
- The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA
| | - Theodore J Price
- The BIO5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA.,Department of Pharmacology, University of Arizona, Tucson, AZ, USA.,School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| |
Collapse
|
45
|
Kenakin T. Gaddum Memorial Lecture 2014: receptors as an evolving concept: from switches to biased microprocessors. Br J Pharmacol 2015; 172:4238-53. [PMID: 26075971 DOI: 10.1111/bph.13217] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/06/2015] [Accepted: 03/16/2015] [Indexed: 12/17/2022] Open
Abstract
This review is based on the JR Vane Medal Lecture presented at the BPS Winter Meeting in December 2014 by T. Kenakin. A recording of the lecture is included as supporting information and can also be viewed online here: https://www.youtube.com/watch?v=xrP81AQ8l-8. Pharmacological models used to describe drug agonism and antagonism have evolved over the past 20 years from a parsimonious model describing single active and inactive receptor states to models of multiconformational receptor systems modified by ligand conformational selection. These latter models describe the observed, presently underexploited, pharmacological mechanism of ligand-directed biased signalling. Biased signals can be quantified with transduction coefficients (ΔΔLog(τ/KA) values), a scale grounded in the Black/Leff operational model; this enables the optimization of biased profiles through medicinal chemistry. The past decades have also brought the availability of new technologies to measure multiple functional effects mediated by seven transmembrane receptors. These have confirmed that drugs can have many efficacies, which may be collaterally linked, that is there is no linear sequence of activities required. In addition, new functional screening assays have introduced increasing numbers of allosteric ligands into drug discovery. These molecules are permissive (they do not necessarily preclude endogenous signalling in vivo); therefore, they may allow better fine tuning of pathological physiology. The permissive quality of allosteric ligands can also change the quality of endogenous signalling efficacy ('induced bias') as well as the quantity of signal; in this regard, indices related to ΔΔLog(τ/KA) values (namely ΔLog(αβ) values) can be used to quantify these effects for optimization in the drug discovery process. All of these added scales of drug activity will, hopefully, allow better targeting of candidate molecules towards therapies.
Collapse
Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| |
Collapse
|
46
|
Shonberg J, Draper-Joyce C, Mistry SN, Christopoulos A, Scammells PJ, Lane JR, Capuano B. Structure-activity study of N-((trans)-4-(2-(7-cyano-3,4-dihydroisoquinolin-2(1H)-yl)ethyl)cyclohexyl)-1H-indole-2-carboxamide (SB269652), a bitopic ligand that acts as a negative allosteric modulator of the dopamine D2 receptor. J Med Chem 2015; 58:5287-307. [PMID: 26052807 DOI: 10.1021/acs.jmedchem.5b00581] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We recently demonstrated that SB269652 (1) engages one protomer of a dopamine D2 receptor (D2R) dimer in a bitopic mode to allosterically inhibit the binding of dopamine at the other protomer. Herein, we investigate structural determinants for allostery, focusing on modifications to three moieties within 1. We find that orthosteric "head" groups with small 7-substituents were important to maintain the limited negative cooperativity of analogues of 1, and replacement of the tetrahydroisoquinoline head group with other D2R "privileged structures" generated orthosteric antagonists. Additionally, replacement of the cyclohexylene linker with polymethylene chains conferred linker length dependency in allosteric pharmacology. We validated the importance of the indolic NH as a hydrogen bond donor moiety for maintaining allostery. Replacement of the indole ring with azaindole conferred a 30-fold increase in affinity while maintaining negative cooperativity. Combined, these results provide novel SAR insight for bitopic ligands that act as negative allosteric modulators of the D2R.
Collapse
Affiliation(s)
- Jeremy Shonberg
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Christopher Draper-Joyce
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Shailesh N Mistry
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Arthur Christopoulos
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Peter J Scammells
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - J Robert Lane
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Ben Capuano
- †Medicinal Chemistry, and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| |
Collapse
|
47
|
|
48
|
Huot P, Fox SH, Brotchie JM. Monoamine reuptake inhibitors in Parkinson's disease. PARKINSON'S DISEASE 2015; 2015:609428. [PMID: 25810948 PMCID: PMC4355567 DOI: 10.1155/2015/609428] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 12/26/2014] [Indexed: 12/13/2022]
Abstract
The motor manifestations of Parkinson's disease (PD) are secondary to a dopamine deficiency in the striatum. However, the degenerative process in PD is not limited to the dopaminergic system and also affects serotonergic and noradrenergic neurons. Because they can increase monoamine levels throughout the brain, monoamine reuptake inhibitors (MAUIs) represent potential therapeutic agents in PD. However, they are seldom used in clinical practice other than as antidepressants and wake-promoting agents. This review article summarises all of the available literature on use of 50 MAUIs in PD. The compounds are divided according to their relative potency for each of the monoamine transporters. Despite wide discrepancy in the methodology of the studies reviewed, the following conclusions can be drawn: (1) selective serotonin transporter (SERT), selective noradrenaline transporter (NET), and dual SERT/NET inhibitors are effective against PD depression; (2) selective dopamine transporter (DAT) and dual DAT/NET inhibitors exert an anti-Parkinsonian effect when administered as monotherapy but do not enhance the anti-Parkinsonian actions of L-3,4-dihydroxyphenylalanine (L-DOPA); (3) dual DAT/SERT inhibitors might enhance the anti-Parkinsonian actions of L-DOPA without worsening dyskinesia; (4) triple DAT/NET/SERT inhibitors might exert an anti-Parkinsonian action as monotherapy and might enhance the anti-Parkinsonian effects of L-DOPA, though at the expense of worsening dyskinesia.
Collapse
Affiliation(s)
- Philippe Huot
- Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
- Division of Neurology, Movement Disorder Clinic, Toronto Western Hospital, University Health Network, University of Toronto, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
- Department of Pharmacology and Division of Neurology, Faculty of Medicine, Université de Montréal and Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
| | - Susan H. Fox
- Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
- Division of Neurology, Movement Disorder Clinic, Toronto Western Hospital, University Health Network, University of Toronto, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
| | - Jonathan M. Brotchie
- Toronto Western Research Institute, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
| |
Collapse
|
49
|
Hathaway HA, Pshenichkin S, Grajkowska E, Gelb T, Emery AC, Wolfe BB, Wroblewski JT. Pharmacological characterization of mGlu1 receptors in cerebellar granule cells reveals biased agonism. Neuropharmacology 2015; 93:199-208. [PMID: 25700650 DOI: 10.1016/j.neuropharm.2015.02.007] [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: 10/28/2014] [Revised: 02/02/2015] [Accepted: 02/04/2015] [Indexed: 01/14/2023]
Abstract
The majority of existing research on the function of metabotropic glutamate (mGlu) receptor 1 focuses on G protein-mediated outcomes. However, similar to other G protein-coupled receptors (GPCR), it is becoming apparent that mGlu1 receptor signaling is multi-dimensional and does not always involve G protein activation. Previously, in transfected CHO cells, we showed that mGlu1 receptors activate a G protein-independent, β-arrestin-dependent signal transduction mechanism and that some mGlu1 receptor ligands were incapable of stimulating this response. Here we set out to investigate the physiological relevance of these findings in a native system using primary cultures of cerebellar granule cells. We tested the ability of a panel of compounds to stimulate two mGlu1 receptor-mediated outcomes: (1) protection from decreased cell viability after withdrawal of trophic support and (2) G protein-mediated phosphoinositide (PI) hydrolysis. We report that the commonly used mGlu1 receptor ligands quisqualate, DHPG, and ACPD are completely biased towards PI hydrolysis and do not induce mGlu1 receptor-stimulated neuroprotection. On the other hand, endogenous compounds including glutamate, aspartate, cysteic acid, cysteine sulfinic acid, and homocysteic acid stimulate both responses. These results show that some commonly used mGlu1 receptor ligands are biased agonists, stimulating only a fraction of mGlu1 receptor-mediated responses in neurons. This emphasizes the importance of utilizing multiple agonists and assays when studying GPCR function.
Collapse
Affiliation(s)
- Hannah A Hathaway
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, USA.
| | - Sergey Pshenichkin
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, USA
| | - Ewa Grajkowska
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, USA
| | - Tara Gelb
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, USA
| | - Andrew C Emery
- Section on Molecular Neuroscience, National Institute of Mental Health IRP, Bldg 49, Room 5A27, Bethesda, MD 20892, USA
| | - Barry B Wolfe
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, USA
| | - Jarda T Wroblewski
- Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, USA
| |
Collapse
|
50
|
Interaction of fenoterol stereoisomers with β2-adrenoceptor-G sα fusion proteins: antagonist and agonist competition binding. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:517-24. [PMID: 25637582 DOI: 10.1007/s00210-015-1086-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/09/2015] [Indexed: 10/24/2022]
Abstract
The specific interaction between G-protein-coupled receptors and ligand is the starting point for downstream signaling. Fenoterol stereoisomers were successfully used to probe ligand-specific activation (functional selectivity) of the β2-adrenoceptor (β2AR) (Reinartz et al. 2015). In the present study, we extended the pharmacological profile of fenoterol stereoisomers using β2AR-Gsα fusion proteins in agonist and antagonist competition binding assays. Dissociations between binding affinities and effector potencies were found for (R,S')- and (S,S')-isomers of 4'-methoxy-1-naphthyl-fenoterol. Our data corroborate former studies on the importance of the aminoalkyl moiety of fenoterol derivatives for functional selectivity.
Collapse
|