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Nguyen ATN, Tran QL, Baltos JA, McNeill SM, Nguyen DTN, May LT. Small molecule allosteric modulation of the adenosine A 1 receptor. Front Endocrinol (Lausanne) 2023; 14:1184360. [PMID: 37435481 PMCID: PMC10331460 DOI: 10.3389/fendo.2023.1184360] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 05/23/2023] [Indexed: 07/13/2023] Open
Abstract
G protein-coupled receptors (GPCRs) represent the target for approximately a third of FDA-approved small molecule drugs. The adenosine A1 receptor (A1R), one of four adenosine GPCR subtypes, has important (patho)physiological roles in humans. A1R has well-established roles in the regulation of the cardiovascular and nervous systems, where it has been identified as a potential therapeutic target for a number of conditions, including cardiac ischemia-reperfusion injury, cognition, epilepsy, and neuropathic pain. A1R small molecule drugs, typically orthosteric ligands, have undergone clinical trials. To date, none have progressed into the clinic, predominantly due to dose-limiting unwanted effects. The development of A1R allosteric modulators that target a topographically distinct binding site represent a promising approach to overcome current limitations. Pharmacological parameters of allosteric ligands, including affinity, efficacy and cooperativity, can be optimized to regulate A1R activity with high subtype, spatial and temporal selectivity. This review aims to offer insights into the A1R as a potential therapeutic target and highlight recent advances in the structural understanding of A1R allosteric modulation.
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Affiliation(s)
- Anh T. N. Nguyen
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Quan L. Tran
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Jo-Anne Baltos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Samantha M. McNeill
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Diep T. N. Nguyen
- Department of Information Technology, Faculty of Engineering and Technology, Vietnam National University, Hanoi, Vietnam
| | - Lauren T. May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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2
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Fu K, Chen W, Meng M, Zhao H, Yuan H, Wang Y, Ren Y, Yun Y, Guo D. An allosteric modulator of the adenosine A 1 receptor potentiates the antilipolytic effect in rat adipose tissue. Eur J Pharmacol 2023; 951:175777. [PMID: 37182594 DOI: 10.1016/j.ejphar.2023.175777] [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: 01/05/2023] [Revised: 05/04/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Abstract
The adenosine A1 receptor plays important roles in tuning free fatty acid (FFA) levels and represents an attractive target for metabolic disorders. Though remarkable progress has been achieved in the exploitation of effective (orthosteric) A1 receptor agonists in modulating aberrant FFA levels, the effect of A1 receptor allosteric modulation on lipid homeostasis is less investigated. Herein we sought to explore the effect of an allosteric modulator on the action of an A1 receptor orthosteric agonist in regulating the lipolytic process in vitro and in vivo. We examined the binding kinetics of a selective A1 receptor agonist 2-chloro-N6-cyclopentyladenosine (CCPA) in the absence or presence of an allosteric modulator (2-amino-4,5-dimethyl-3-thienyl)-[3-(trifluoromethyl)-phenyl]methanone (PD81,723) on rat adipocyte membranes. We also examined the allosteric effects of PD81,723 on mediating the CCPA-induced inhibition of cAMP accumulation, HSL (hormone-sensitive lipase) phosphorylation and FFA production in in vitro and in vivo models. Our results demonstrated that PD81,723 slowed down the dissociation of CCPA from the A1 receptor, which, consequently, potentiated the antilipolytic action of CCPA through downregulating the cAMP/HSL pathway. Our study exemplified the application of A1 receptor allosteric modulators as an alternative for metabolic disease treatments.
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Affiliation(s)
- Kequan Fu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Wenbing Chen
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Mingzhu Meng
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Huimin Zhao
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Haoxing Yuan
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Yinan Wang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Ying Ren
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Yi Yun
- The Affiliated Suqian First People's Hospital of Nanjing Medical University, 120 Suzhi Road, Suqian, 223800, Jiangsu, China.
| | - Dong Guo
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China.
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3
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IJzerman AP, Jacobson KA, Müller CE, Cronstein BN, Cunha RA. International Union of Basic and Clinical Pharmacology. CXII: Adenosine Receptors: A Further Update. Pharmacol Rev 2022; 74:340-372. [PMID: 35302044 PMCID: PMC8973513 DOI: 10.1124/pharmrev.121.000445] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Our previous International Union of Basic and Clinical Pharmacology report on the nomenclature and classification of adenosine receptors (2011) contained a number of emerging developments with respect to this G protein-coupled receptor subfamily, including protein structure, protein oligomerization, protein diversity, and allosteric modulation by small molecules. Since then, a wealth of new data and results has been added, allowing us to explore novel concepts such as target binding kinetics and biased signaling of adenosine receptors, to examine a multitude of receptor structures and novel ligands, to gauge new pharmacology, and to evaluate clinical trials with adenosine receptor ligands. This review should therefore be considered a further update of our previous reports from 2001 and 2011. SIGNIFICANCE STATEMENT: Adenosine receptors (ARs) are of continuing interest for future treatment of chronic and acute disease conditions, including inflammatory diseases, neurodegenerative afflictions, and cancer. The design of AR agonists ("biased" or not) and antagonists is largely structure based now, thanks to the tremendous progress in AR structural biology. The A2A- and A2BAR appear to modulate the immune response in tumor biology. Many clinical trials for this indication are ongoing, whereas an A2AAR antagonist (istradefylline) has been approved as an anti-Parkinson agent.
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Affiliation(s)
- Adriaan P IJzerman
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Kenneth A Jacobson
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Christa E Müller
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Bruce N Cronstein
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Rodrigo A Cunha
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
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4
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Jung SM, Peyton L, Essa H, Choi DS. Adenosine receptors: Emerging non-opioids targets for pain medications. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2022; 11:100087. [PMID: 35372716 PMCID: PMC8971635 DOI: 10.1016/j.ynpai.2022.100087] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 11/16/2022]
Abstract
Physical and emotional pain deteriorates the quality of well-being. Also, numerous non-invasive and invasive treatments for diagnosed diseases such as cancer medications and surgical procedures cause various types of pain. Despite the multidisciplinary approaches available to manage pain, the unmet needs for medication with minimal side effects are substantial. Especially with the surge of opioid crisis during the last decades, non-opioid analgesics may reduce life-threatening overdosing and addictive liability. Although many clinical trials supported the potential potency of cannabis and cannabidiol (CBD) in pain management or treatment, the long-term benefits of cannabis or CBD are still not evident. At the same time, growing evidence shows the risk of overusing cannabis and CBD. Therefore, it is urgent to develop novel analgesic medications that minimize side effects. All four well-identified adenosine receptors, A1, A2A, A2B, and A3, are implicated in pain. Recently, a report demonstrated that an adenosine A1R-specific positive allosteric modulator (PAM) is a potent analgesic without noticeable side effects. Also, several A3R agonists are being considered as promising analgesic agent. However, the importance of adenosine in pain is relatively underestimated. To help readers understand, first, we will summarize the historical perspective of the adenosine system in preclinical and clinical studies. Then, we will discuss possible interactions of adenosine and opioids or the cannabis system focusing on pain. Overall, this review will provide the potential role of adenosine and adenosine receptors in pain treatment.
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Affiliation(s)
- Soo-Min Jung
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - Lee Peyton
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - Hesham Essa
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - Doo-Sup Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, United States.,Neuroscience Program, Mayo Clinic College of Medicine and Science, Rochester, MN, United States.,Department of Psychiatry and Psychology, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
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5
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McNeill SM, Baltos JA, White PJ, May LT. Biased agonism at adenosine receptors. Cell Signal 2021; 82:109954. [PMID: 33610717 DOI: 10.1016/j.cellsig.2021.109954] [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: 11/10/2020] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 01/14/2023]
Abstract
Adenosine modulates many aspects of human physiology and pathophysiology through binding to the adenosine family of G protein-coupled receptors, which are comprised of four subtypes, the A1R, A2AR, A2BR and A3R. Modulation of adenosine receptor function by exogenous agonists, antagonists and allosteric modulators can be beneficial for a number of conditions including cardiovascular disease, Parkinson's disease, and cancer. Unfortunately, many preclinical drug candidates targeting adenosine receptors have failed in clinical trials due to limited efficacy and/or severe on-target undesired effects. To overcome the key barriers typically encountered when transitioning adenosine receptor ligands into the clinic, research efforts have focussed on exploiting the phenomenon of biased agonism. Biased agonism provides the opportunity to develop ligands that favour therapeutic signalling pathways, whilst avoiding signalling associated with on-target undesired effects. Recent studies have begun to define the structure-function relationships that underpin adenosine receptor biased agonism and establish how this phenomenon can be harnessed therapeutically. In this review we describe the recent advancements made towards achieving therapeutically relevant biased agonism at adenosine receptors.
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Affiliation(s)
- Samantha M McNeill
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Jo-Anne Baltos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Department of Pharmacology, Monash University, Melbourne, VIC, Australia.
| | - Paul J White
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Lauren T May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Department of Pharmacology, Monash University, Melbourne, VIC, Australia.
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6
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Cooper SL, March J, Sabbatini AR, Hill SJ, Jörg M, Scammells PJ, Woolard J. The effect of two selective A 1 -receptor agonists and the bitopic ligand VCP746 on heart rate and regional vascular conductance in conscious rats. Br J Pharmacol 2019; 177:346-359. [PMID: 31596949 PMCID: PMC6989947 DOI: 10.1111/bph.14870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 11/30/2022] Open
Abstract
Background and Purpose Adenosine is a local mediator that regulates physiological and pathological processes via activation of four GPCRs (A1, A2A, A2B, and A3). We have investigated the effect of two A1‐receptor‐selective agonists and the novel A1‐receptor bitopic ligand VCP746 on the rat cardiovascular system. Experimental Approach The regional haemodynamic responses of these agonist was investigated in conscious rats. Male Sprague–Dawley rats (350–450 g) were chronically implanted with pulsed Doppler flow probes on the renal, mesenteric arteries and the descending abdominal aorta and the jugular vein and caudal artery catheterized. Cardiovascular responses were measured following intravenous infusion (3 min each dose) of CCPA (120, 400, and 1,200 ng·kg−1·min−1), capadenoson or adenosine (30, 100, and 300 μg·kg−1·min−1), or VCP746 (6, 20, and 60 μg·kg−1·min−1) following pre‐dosing with DPCPX (0.1 mg·kg−1, i.v.) or vehicle. Key Results CCPA produced a significant A1‐receptor‐mediated decrease in heart rate that was accompanied by vasoconstrictions in the renal and mesenteric vascular beds but an increase in hindquarters vascular conductance. The partial agonist capadenoson also produced an A1‐receptor‐mediated bradycardia. In contrast, VCP746 produced increases in heart rate and renal and mesenteric vascular conductance that were not mediated by A1‐receptors. In vitro studies confirmed that VCP746 had potent agonist activity at both A2A‐ and A2B‐receptors. Conclusions and Implications These results suggest VCP746 mediates its cardiovascular effects via activation of A2 rather than A1 adenosine receptors. This has implications for the design of future bitopic ligands that incorporate A1 allosteric ligand moieties.
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Affiliation(s)
- Samantha L Cooper
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Julie March
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Andrea R Sabbatini
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Manuela Jörg
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
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7
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Cooper SL, Soave M, Jörg M, Scammells PJ, Woolard J, Hill SJ. Probe dependence of allosteric enhancers on the binding affinity of adenosine A 1 -receptor agonists at rat and human A 1 -receptors measured using NanoBRET. Br J Pharmacol 2019; 176:864-878. [PMID: 30644086 PMCID: PMC6433648 DOI: 10.1111/bph.14575] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 11/02/2018] [Accepted: 12/04/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Adenosine is a local mediator that regulates a number of physiological and pathological processes via activation of adenosine A1 -receptors. The activity of adenosine can be regulated at the level of its target receptor via drugs that bind to an allosteric site on the A1 -receptor. Here, we have investigated the species and probe dependence of two allosteric modulators on the binding characteristics of fluorescent and nonfluorescent A1 -receptor agonists. EXPERIMENTAL APPROACH A Nano-luciferase (Nluc) BRET (NanoBRET) methodology was used. This used N-terminal Nluc-tagged A1 -receptors expressed in HEK293T cells in conjunction with both fluorescent A1 -receptor agonists (adenosine and NECA analogues) and a fluorescent antagonist CA200645. KEY RESULTS PD 81,723 and VCP171 elicited positive allosteric effects on the binding affinity of orthosteric agonists at both the rat and human A1 -receptors that showed clear probe dependence. Thus, the allosteric effect on the highly selective partial agonist capadenoson was much less marked than for the full agonists NECA, adenosine, and CCPA in both species. VCP171 and, to a lesser extent, PD 81,723, also increased the specific binding of three fluorescent A1 -receptor agonists in a species-dependent manner that involved increases in Bmax and pKD . CONCLUSIONS AND IMPLICATIONS These results demonstrate the power of the NanoBRET ligand-binding approach to study the effect of allosteric ligands on the binding of fluorescent agonists to the adenosine A1 -receptor in intact living cells. Furthermore, our studies suggest that VCP171 and PD 81,723 may switch a proportion of A1 -receptors to an active agonist conformation (R*).
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Affiliation(s)
- Samantha L Cooper
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Manuela Jörg
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
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8
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Abstract
G protein-coupled receptors are the largest family of targets for current therapeutics. The classic model of their activation was binary, where agonist binding induced an active conformation and subsequent downstream signaling. Subsequently, the revised concept of biased agonism emerged, where different ligands at the same G protein-coupled receptor selectively activate one downstream pathway versus another. Advances in understanding the mechanism of biased agonism have led to the development of novel ligands, which have the potential for improved therapeutic and safety profiles. In this review, we summarize the theory and most recent breakthroughs in understanding biased signaling, examine recent laboratory investigations concerning biased ligands across different organ systems, and discuss the promising clinical applications of biased agonism.
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9
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Satała G, Duszyńska B, Stachowicz K, Rafalo A, Pochwat B, Luckhart C, Albert PR, Daigle M, Tanaka KF, Hen R, Lenda T, Nowak G, Bojarski AJ, Szewczyk B. Concentration-Dependent Dual Mode of Zn Action at Serotonin 5-HT1A Receptors: In Vitro and In Vivo Studies. Mol Neurobiol 2016; 53:6869-6881. [PMID: 26660328 PMCID: PMC5104769 DOI: 10.1007/s12035-015-9586-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/29/2015] [Indexed: 12/17/2022]
Abstract
Recent data has indicated that Zn can modulate serotonergic function through the 5-HT1A receptor (5-HT1AR); however, the exact mechanisms are unknown. In the present studies, radioligand binding assays and behavioural approaches were used to characterize the pharmacological profile of Zn at 5-HT1ARs in more detail. The influence of Zn on agonist binding to 5-HT1ARs stably expressed in HEK293 cells was investigated by in vitro radioligand binding methods using the agonist [3H]-8-OH-DPAT. The in vivo effects of Zn were compared with those of 8-OH-DPAT in hypothermia, lower lip retraction (LLR), 5-HT behavioural syndrome and the forced swim (FST) tests. In the in vitro studies, biphasic effects, which involved allosteric potentiation of agonist binding at sub-micromolar Zn concentrations and inhibition at sub-millimolar Zn concentrations, were found. The in vivo studies showed that Zn did not induce LLR or elements of 5-HT behavioural syndrome but blocked such effects induced by 8-OH-DPAT. Zn decreased body temperature in rats and mice; however, Zn failed to induce hypothermia in the 5-HT1A autoreceptor knockout mice. In the FST, Zn potentiated the effect of 8-OH-DPAT. However, in the FST performed with the 5-HT1A autoreceptor knockout mice, the anti-immobility effect of Zn was partially blocked. Both the binding and behavioural studies suggest a concentration-dependent dual mechanism of Zn action at 5-HT1ARs, with potentiation at low dose and inhibition at high dose. Moreover, the in vivo studies indicate that Zn can modulate both presynaptic and postsynaptic 5-HT1ARs; however, Zn's effects at presynaptic receptors seem to be more potent.
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Affiliation(s)
- Grzegorz Satała
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Beata Duszyńska
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Katarzyna Stachowicz
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Anna Rafalo
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Bartlomiej Pochwat
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Christine Luckhart
- Ottawa Hospital Research Institute, UOttawa Brain and Mind Research Institute , 451 Smyth Road #2464, Ottawa, ON, K1H-8M5, Canada
| | - Paul R Albert
- Ottawa Hospital Research Institute, UOttawa Brain and Mind Research Institute , 451 Smyth Road #2464, Ottawa, ON, K1H-8M5, Canada
| | - Mireille Daigle
- Ottawa Hospital Research Institute, UOttawa Brain and Mind Research Institute , 451 Smyth Road #2464, Ottawa, ON, K1H-8M5, Canada
| | - Kenji F Tanaka
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, 160-8582, Japan
| | - René Hen
- Department of Psychiatry, Columbia University Medical Center and Research Foundation for Mental Hygiene, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Tomasz Lenda
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Gabriel Nowak
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Andrzej J Bojarski
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland
| | - Bernadeta Szewczyk
- Institute of Pharmacology Polish Academy of Sciences , Smetna 12, PL 31-343, Krakow, Poland.
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10
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Nguyen ATN, Vecchio EA, Thomas T, Nguyen TD, Aurelio L, Scammells PJ, White PJ, Sexton PM, Gregory KJ, May LT, Christopoulos A. Role of the Second Extracellular Loop of the Adenosine A1 Receptor on Allosteric Modulator Binding, Signaling, and Cooperativity. Mol Pharmacol 2016; 90:715-725. [PMID: 27683013 DOI: 10.1124/mol.116.105015] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/27/2016] [Indexed: 02/05/2023] Open
Abstract
Allosteric modulation of adenosine A1 receptors (A1ARs) offers a novel therapeutic approach for the treatment of numerous central and peripheral disorders; however, despite decades of research, there is a relative paucity of structural information regarding the A1AR allosteric site and mechanisms governing cooperativity with orthosteric ligands. We combined alanine-scanning mutagenesis of the A1AR second extracellular loop (ECL2) with radioligand binding and functional interaction assays to quantify effects on allosteric ligand affinity, cooperativity, and efficacy. Docking and molecular dynamics (MD) simulations were performed using an A1AR homology model based on an agonist-bound A2AAR structure. Substitution of E172ECL2 for alanine reduced the affinity of the allosteric modulators PD81723 and VCP171 for the unoccupied A1AR. Residues involved in cooperativity with the orthosteric agonist NECA were different in PD81723 and VCP171; positive cooperativity between PD81723 and NECA was reduced on alanine substitution of a number of ECL2 residues, including E170ECL2 and K173ECL2, whereas mutation of W146ECL2 and W156ECL2 decreased VCP171 cooperativity with NECA. Molecular modeling localized a likely allosteric pocket for both modulators to an extracellular vestibule that overlaps with a region used by orthosteric ligands as they transit into the canonical A1AR orthosteric site. MD simulations confirmed a key interaction between E172ECL2 and both modulators. Bound PD81723 is flanked by another residue, E170ECL2, which forms hydrogen bonds with adjacent K168ECL2 and K173ECL2. Collectively, our data suggest E172ECL2 is a key allosteric ligand-binding determinant, whereas hydrogen-bonding networks within the extracellular vestibule may facilitate the transmission of cooperativity between orthosteric and allosteric sites.
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Affiliation(s)
- Anh T N Nguyen
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Elizabeth A Vecchio
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Trayder Thomas
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Toan D Nguyen
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Peter J Scammells
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Paul J White
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Patrick M Sexton
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Karen J Gregory
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Lauren T May
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
| | - Arthur Christopoulos
- Monash Institute of Pharmaceutical Sciences (A.T.N.N., E.A.V., T.T., L.A., P.J.S., P.J.W., P.M.S., K.J.G., L.T.M., A.C.), Monash e-Research Centre (T.D.N.), and Department of Pharmacology (A.T.N.N., E.A.V., P.M.S., K.J.G., L.T.M., A.C), Monash University, Victoria, Australia
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11
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Abstract
Adenosine is an ubiquitous nucleoside involved in various physiological and pathological functions by stimulating A1, A2A, A2B and A3 adenosine receptors (ARs). Allosteric enhancers to A1ARs may represent novel therapeutic agents because they increase the activity of these receptors by mediating a shift to their active form in the A1AR-G protein ternary complex. In this manner, they are able to amplify the action of endogenous adenosine, which is produced in high concentrations under conditions of metabolic stress. A1AR allosteric enhancers could be used as a justifiable alternative to the exogenous agonists that are characterized by receptor desensitization and downregulation. In this review, an analysis of some of the most interesting allosteric modulators of A1ARs has been reported.
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12
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Synthesis and biological evaluation of a new series of 2-amino-3-aroyl thiophene derivatives as agonist allosteric modulators of the A1 adenosine receptor. A position-dependent effect study. Eur J Med Chem 2015; 101:185-204. [PMID: 26141910 DOI: 10.1016/j.ejmech.2015.06.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/05/2015] [Accepted: 06/22/2015] [Indexed: 11/20/2022]
Abstract
The 2-amino-3-(p-chlorobenzoyl)thiophene scaffold has been widely employed as a pharmacophore for the identification of small molecules acting as allosteric modulators at the adenosine A1 receptor. A new series of 2-amino-3-(p-chlorobenzoyl)-4-benzyl-5-arylthiophene derivatives, characterized by the absence as well as the presence of electron-releasing or electron-withdrawing groups on the phenyl ring at the 4- and 5-positions of the thiophene ring, were identified as positive allosteric enhancers at the adenosine A1 receptor in binding (saturation, competition and dissociation kinetics) and functional assays. To better understand the positional requirements of substituents on the 2-amino-3-(p-chlorobenzoyl)thiophene core, the corresponding regioisomeric 4-aryl-5-benzylthiophene analogues were synthesized and found to possess reduced allosteric enhancer activity.
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13
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Imlach WL, Bhola RF, May LT, Christopoulos A, Christie MJ. A Positive Allosteric Modulator of the Adenosine A1 Receptor Selectively Inhibits Primary Afferent Synaptic Transmission in a Neuropathic Pain Model. Mol Pharmacol 2015; 88:460-8. [DOI: 10.1124/mol.115.099499] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 06/23/2015] [Indexed: 11/22/2022] Open
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14
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Root-Bernstein R, Dillon PF. A common molecular motif characterizes extracellular allosteric enhancers of GPCR aminergic receptors and suggests enhancer mechanism of action. Curr Med Chem 2015; 21:3673-86. [PMID: 25174918 PMCID: PMC4266041 DOI: 10.2174/0929867321666140826120604] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 04/08/2014] [Accepted: 08/22/2014] [Indexed: 11/22/2022]
Abstract
Several classes of compounds that have no intrinsic activity on aminergic systems nonetheless enhance the potency of aminergic receptor ligands three-fold or more while significantly increasing their duration of activity, preventing tachyphylaxis and reversing fade. Enhancer compounds include ascorbic acid, ethylenediaminetetraacetic acid, cortico-steroids, opioid peptides, opiates and opiate antagonists. This paper provides the first review of aminergic enhancement, demonstrating that all enhancers have a common, inobvious molecular motif and work through a common mechanism that is manifested by three common characteristics. First, aminergic enhancers bind directly to the amines they enhance, suggesting that the common structural motif is reflected in common binding targets. Second, one common target is the first extracellular loop of aminergic receptors. Third, at least some enhancers are antiphosphodiesterases. These observations suggest that aminergic enhancers act on the extracellular surface of aminergic receptors to keep the receptor in its high affinity state, trapping the ligand inside the receptor. Enhancer binding produces allosteric modifications of the receptor structure that interfere with phosphorylation of the receptor, thereby inhibiting down-regulation of the receptor. The mechanism explains how enhancers potentiate aminergic activity and increase duration of activity and makes testable predictions about additional compounds that should act as aminergic enhancers.
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Affiliation(s)
| | - Patrick F Dillon
- Department of Physiology, Michigan State University, East Lansing, MI 48824 USA.
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15
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Leach K, Conigrave AD, Sexton PM, Christopoulos A. Towards tissue-specific pharmacology: insights from the calcium-sensing receptor as a paradigm for GPCR (patho)physiological bias. Trends Pharmacol Sci 2015; 36:215-25. [PMID: 25765207 DOI: 10.1016/j.tips.2015.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 12/25/2022]
Abstract
The calcium-sensing receptor (CaSR) is a widely expressed G protein-coupled receptor (GPCR) that mediates numerous tissue-specific functions. Its multiple ligands and diverse roles attest to the need for exquisite control over the signaling pathways that mediate its effects. 'Biased signaling' is the phenomenon by which distinct ligands stabilize preferred receptor signaling states. The CaSR is subject to biased signaling in response to its endogenous ligands. Interestingly, the 'natural' bias of the CaSR is altered in disease states, and small molecule drugs engender biased allosteric modulation of downstream signaling pathways. Thus, biased signaling from the CaSR also has important implications pathophysiologically and therapeutically. As outlined in this review, this novel paradigm extends to other GPCRs, making the CaSR a model for studies of ligand-biased signaling and for understanding how it may be used to foster selective drug activity in different tissues.
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Affiliation(s)
- Katie Leach
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville VIC, Australia.
| | - Arthur D Conigrave
- School of Molecular Bioscience, Charles Perkins Centre, University of Sydney, NSW 2006, Australia
| | - Patrick M Sexton
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville VIC, Australia
| | - Arthur Christopoulos
- Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville VIC, Australia
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16
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Hill SJ, May LT, Kellam B, Woolard J. Allosteric interactions at adenosine A(1) and A(3) receptors: new insights into the role of small molecules and receptor dimerization. Br J Pharmacol 2014; 171:1102-13. [PMID: 24024783 DOI: 10.1111/bph.12345] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 12/22/2022] Open
Abstract
The purine nucleoside adenosine is present in all cells in tightly regulated concentrations. It is released under a variety of physiological and pathophysiological conditions to facilitate protection and regeneration of tissues. Adenosine acts via specific GPCRs to either stimulate cyclic AMP formation, as exemplified by Gs -protein-coupled adenosine receptors (A2A and A2B ), or inhibit AC activity, in the case of Gi/o -coupled adenosine receptors (A1 and A3 ). Recent advances in our understanding of GPCR structure have provided insights into the conformational changes that occur during receptor activation following binding of agonists to orthosteric (i.e. at the same binding site as an endogenous modulator) and allosteric regulators to allosteric sites (i.e. at a site that is topographically distinct from the endogenous modulator). Binding of drugs to allosteric sites may lead to changes in affinity or efficacy, and affords considerable potential for increased selectivity in new drug development. Herein, we provide an overview of the properties of selective allosteric regulators of the adenosine A1 and A3 receptors, focusing on the impact of receptor dimerization, mechanistic approaches to single-cell ligand-binding kinetics and the effects of A1 - and A3 -receptor allosteric modulators on in vivo pharmacology.
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Affiliation(s)
- Stephen J Hill
- Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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17
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Romagnoli R, Baraldi PG, IJzerman AP, Massink A, Cruz-Lopez O, Lopez-Cara LC, Saponaro G, Preti D, Aghazadeh Tabrizi M, Baraldi S, Moorman AR, Vincenzi F, Borea PA, Varani K. Synthesis and Biological Evaluation of Novel Allosteric Enhancers of the A1 Adenosine Receptor Based on 2-Amino-3-(4′-Chlorobenzoyl)-4-Substituted-5-Arylethynyl Thiophene. J Med Chem 2014; 57:7673-86. [DOI: 10.1021/jm5008853] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Romeo Romagnoli
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Pier Giovanni Baraldi
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Adriaan P. IJzerman
- Leiden Academic
Centre for Drug Research, Division of Medicinal Chemistry, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Arnault Massink
- Leiden Academic
Centre for Drug Research, Division of Medicinal Chemistry, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Olga Cruz-Lopez
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Luisa Carlota Lopez-Cara
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Giulia Saponaro
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Delia Preti
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Mojgan Aghazadeh Tabrizi
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Stefania Baraldi
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato
di Mortara 17-19, 44121 Ferrara, Italy
| | - Allan R. Moorman
- King Pharmaceuticals
Inc., Research and Development, 4000
CentreGreen Way, Suite 300, Cary, North Carolina 27513
| | - Fabrizio Vincenzi
- Dipartimento
di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Savonarola 9, 44121 Ferrara, Italy
| | - Pier Andrea Borea
- Dipartimento
di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Savonarola 9, 44121 Ferrara, Italy
| | - Katia Varani
- Dipartimento
di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Savonarola 9, 44121 Ferrara, Italy
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18
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Christopoulos A. Advances in G protein-coupled receptor allostery: from function to structure. Mol Pharmacol 2014; 86:463-78. [PMID: 25061106 DOI: 10.1124/mol.114.094342] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It is now widely accepted that G protein-coupled receptors (GPCRs) are highly dynamic proteins that adopt multiple active states linked to distinct functional outcomes. Furthermore, these states can be differentially stabilized not only by orthosteric ligands but also by allosteric ligands acting at spatially distinct binding sites. The key pharmacologic characteristics of GPCR allostery include improved selectivity due to either greater sequence divergence between receptor subtypes and/or subtype-selective cooperativity, a ceiling level to the effect, probe dependence (whereby the magnitude and direction of the allosteric effect change with the nature of the interacting ligands), and the potential for biased signaling. Recent chemical biology developments are beginning to demonstrate how the incorporation of analytical pharmacology and operational modeling into the experimental workflow can enrich structure-activity studies of allostery and bias, and have also led to the discovery of a new class of hybrid orthosteric/allosteric (bitopic) molecules. The potential for endogenous allosteric modulators to play a role in physiology and disease remains to be fully appreciated but will likely represent an important area for future studies. Finally, breakthroughs in structural and computational biology are beginning to unravel the mechanistic basis of GPCR allosteric modulation at the molecular level.
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Affiliation(s)
- Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
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19
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Cortés A, Gracia E, Moreno E, Mallol J, Lluís C, Canela EI, Casadó V. Moonlighting Adenosine Deaminase: A Target Protein for Drug Development. Med Res Rev 2014; 35:85-125. [DOI: 10.1002/med.21324] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Antoni Cortés
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Eduard Gracia
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Estefania Moreno
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Josefa Mallol
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Carme Lluís
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Enric I. Canela
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Vicent Casadó
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
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20
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Davie BJ, Valant C, White JM, Sexton PM, Capuano B, Christopoulos A, Scammells PJ. Synthesis and pharmacological evaluation of analogues of benzyl quinolone carboxylic acid (BQCA) designed to bind irreversibly to an allosteric site of the M ₁ muscarinic acetylcholine receptor. J Med Chem 2014; 57:5405-18. [PMID: 24856614 DOI: 10.1021/jm500556a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Activation of the M1 muscarinic acetylcholine receptor (mAChR) is a prospective treatment for alleviating cognitive decline experienced in central nervous system (CNS) disorders. Current therapeutics indiscriminately enhance the activity of the endogenous neurotransmitter ACh, leading to side effects. BQCA is a positive allosteric modulator and allosteric agonist at the M1 mAChR that has high subtype selectivity and is a promising template from which to generate higher affinity, more pharmacokinetically viable drug candidates. However, to efficiently guide rational drug design, the binding site of BQCA needs to be conclusively elucidated. We report the synthesis and pharmacological validation of BQCA analogues designed to bind irreversibly to the M1 mAChR. One analogue in particular, 11, can serve as a useful structural probe to confirm the location of the BQCA binding site; ideally, by co-crystallization with the M1 mAChR. Furthermore, this ligand may also be used as a pharmacological tool with a range of applications.
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Affiliation(s)
- Briana J Davie
- Medicinal Chemistry and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
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21
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Allosteric modulation and functional selectivity of G protein-coupled receptors. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 10:e237-43. [PMID: 24050274 DOI: 10.1016/j.ddtec.2012.08.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Agonists of a single G protein-coupled receptor (GPCR) may activate distinct signaling pathways. Functional selectivity, an emerging concept with therapeutic relevance for GPCRs, may be due to conformational selection or stabilization with respect to particular agonists, receptor dimerization, variable expression levels of GPCRs and downstream signaling molecules, and allosteric modulation. Allosteric modulators may have potential advantages over orthosteric ligands, including greater selectivity and safety. This review focuses on functional selectivity resulting from allosteric modulation.
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22
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Valant C, May LT, Aurelio L, Chuo CH, White PJ, Baltos JA, Sexton PM, Scammells PJ, Christopoulos A. Separation of on-target efficacy from adverse effects through rational design of a bitopic adenosine receptor agonist. Proc Natl Acad Sci U S A 2014; 111:4614-9. [PMID: 24619092 PMCID: PMC3970544 DOI: 10.1073/pnas.1320962111] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The concepts of allosteric modulation and biased agonism are revolutionizing modern approaches to drug discovery, particularly in the field of G protein-coupled receptors (GPCRs). Both phenomena exploit topographically distinct binding sites to promote unique GPCR conformations that can lead to different patterns of cellular responsiveness. The adenosine A1 GPCR (A1AR) is a major therapeutic target for cardioprotection, but current agents acting on the receptor are clinically limited for this indication because of on-target bradycardia as a serious adverse effect. In the current study, we have rationally designed a novel A1AR ligand (VCP746)--a hybrid molecule comprising adenosine linked to a positive allosteric modulator--specifically to engender biased signaling at the A1AR. We validate that the interaction of VCP746 with the A1AR is consistent with a bitopic mode of receptor engagement (i.e., concomitant association with orthosteric and allosteric sites) and that the compound displays biased agonism relative to prototypical A1AR ligands. Importantly, we also show that the unique pharmacology of VCP746 is (patho)physiologically relevant, because the compound protects against ischemic insult in native A1AR-expressing cardiomyoblasts and cardiomyocytes but does not affect rat atrial heart rate. Thus, this study provides proof of concept that bitopic ligands can be designed as biased agonists to promote on-target efficacy without on-target side effects.
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Affiliation(s)
- Celine Valant
- Drug Discovery Biology and Department of Pharmacology and
| | - Lauren T. May
- Drug Discovery Biology and Department of Pharmacology and
| | - Luigi Aurelio
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Chung Hui Chuo
- Drug Discovery Biology and Department of Pharmacology and
| | - Paul J. White
- Drug Discovery Biology and Department of Pharmacology and
| | - Jo-Anne Baltos
- Drug Discovery Biology and Department of Pharmacology and
| | | | - Peter J. Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
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23
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Synthesis and biological evaluation of novel 2-amino-3-aroyl-4-neopentyl-5-substituted thiophene derivatives as allosteric enhancers of the A₁ adenosine receptor. Bioorg Med Chem 2013; 22:148-66. [PMID: 24332652 DOI: 10.1016/j.bmc.2013.11.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/21/2013] [Indexed: 11/23/2022]
Abstract
2-Amino-3-benzoyl thiophenes have been widely reported to act as allosteric enhancers at the A1 adenosine receptor. Their activity can be increased considerably by appropriate substitutions at the 4- and 5-positions of the thiophene ring. Substituent size at the thiophene C-4 position seemed to be a factor closely related to activity, with the 4-neopentyl (2,2-dimethylpropyl) substitution showing the greatest enhanced activity. A wide series of 2-amino-3-aroyl-4-neopentylthiophene derivatives with general structure 3, characterized by the presence of different substituents (bromine, aryl and heteroaryl) at the 5-position of the thiophene ring, have been identified as potent AEs at the A1AR. With only one exception, all of the synthesized compounds proved to be superior to the reference compound PD 81,723 in a functional assay. Derivatives 3p, 3u, 3am, 3ap and 3ar were the most active compounds in binding (saturation and competition) and functional cAMP studies, being able to potentiate agonist [(3)H]CCPA binding to the A1 receptor.
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Key Words
- 2-Amino-3-benzoylthiophene
- 2-chloro-N(6)-cyclopentyladenosine
- A(1) adenosine receptor
- AE(s)
- Allosteric modulation
- CCPA
- CHO
- CNS
- CsF
- ERG
- EWG
- G protein-coupled receptors
- GPCRs
- N-bromosuccinimide
- NBS
- PdCl(2)(DPPF)
- [(3)H](4-(2-[7-amino-2-(2-furil)[1,2.4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol)
- [(3)H]1,3-dipropyl-8-cyclopentyl-xanthine
- [(3)H]2-chloro-N(6)-cyclopentyladenosine
- [(3)H]5-N-(4-methoxyphenylcarbamoyl)amino-8-propyl-2-(2-furyl)pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine
- [(3)H]CCPA
- [(3)H]DPCPX
- [(3)H]MRE-3008F20
- [(3)H]ZM 241385
- [1,1′-bis(diphenylphosphino)ferrocene] dichloropalladium(II) complex with dichloromethane
- allosteric enhancer(s)
- cAMP
- central nervous system
- cesium fluoride
- chinese hamster ovary
- cyclic adenosine monophosphate
- electron-releasing group
- electron-withdrawing group
- hA(1)AR
- human A(1) adenosine receptor
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Romagnoli R, Baraldi PG, Carrion MD, Lopez Cara C, Kimatrai Salvador M, Preti D, Aghazadeh Tabrizi M, Moorman AR, Vincenzi F, Borea PA, Varani K. Synthesis and biological effects of novel 2-amino-3-(4-chlorobenzoyl)-4-substituted thiophenes as allosteric enhancers of the A1 adenosine receptor. Eur J Med Chem 2013; 67:409-27. [DOI: 10.1016/j.ejmech.2013.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 07/01/2013] [Accepted: 07/06/2013] [Indexed: 11/27/2022]
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An allosteric modulator of the adenosine A1 receptor improves cardiac function following ischaemia in murine isolated hearts. Pharmaceuticals (Basel) 2013; 6:546-56. [PMID: 24276124 PMCID: PMC3816699 DOI: 10.3390/ph6040546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 03/26/2013] [Accepted: 04/01/2013] [Indexed: 12/21/2022] Open
Abstract
The effect of an allosteric modulator of the adenosine A1 receptors was investigated using an ischaemia-reperfusion protocol in murine isolated hearts. Isolated hearts were perfused with Kreb-Henseleit solution gassed with carbogen gas (95% O2 and 5% CO2) in Langendorff mode and electrically paced at 480 bpm. Following 20 min equilibration and 20 min global normothermic ischaemia, the allosteric modulator VCP333 (1 μM) or the adenosine A1 receptor partial agonist VCP102 (10 μM) were infused after 5 min of reperfusion for 15 min. Upon termination of the drug treatment, reperfusion continued for a further 40 min. At the end of 60 min reperfusion, treatment with VCP333 or VCP102 improved the recovery of the left ventricular developed pressure when compared to control group responses (p < 0.05). Neither compound affected end diastolic pressure, coronary flow rates or dP/dtmax values when compared to control tissues during reperfusion (p > 0.05). The infusion of VCP102 or VCP333 during reperfusion reduced cardiac troponin I efflux to 6.7% and 25% respectively of control heart efflux (p < 0.05). This data indicates that the allosteric modulator of the adenosine A1 receptor (VCP333) has similar characteristics to the adenosine receptor partial agonist VCP102 as it improves cardiac function and reduces myocardial cell death following an ischaemic episode.
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Kimatrai-Salvador M, Baraldi PG, Romagnoli R. Allosteric modulation of A1-adenosine receptor: a review. DRUG DISCOVERY TODAY. TECHNOLOGIES 2013; 10:e285-e296. [PMID: 24050280 DOI: 10.1016/j.ddtec.2012.08.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Allosteric modulators of adenosine receptors represent an alternative to direct-acting adenosine agonists and nucleoside uptake blockers, preferably those can selectively modulate the response to adenosine in only those organs or localized areas of a given organ in which production of adenosine is increased. Allosteric enhancers at the adenosine A1 receptor have received attention as anti-arrhythmic cardiac agents, and, more recently, as anti-lipolytic agents. In addition, this class of compounds has therapeutic potential as analgesics and neuroprotective agents.
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Allosteric modulators of rhodopsin-like G protein-coupled receptors: opportunities in drug development. Pharmacol Ther 2012; 135:292-315. [PMID: 22728155 DOI: 10.1016/j.pharmthera.2012.06.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/21/2022]
Abstract
Rhodopsin-like (class A) G protein-coupled receptors (GPCRs) are one of the most important classes of drug targets. The discovery that these GPCRs can be allosterically modulated by small drug molecules has opened up new opportunities in drug development. It will allow the drugability of "difficult targets", such as GPCRs activated by large (glyco)proteins, or by very polar or highly lipophilic physiological agonists. Receptor subtype selectivity should be more easily achievable with allosteric than with orthosteric ligands. Allosteric modulation will allow a broad spectrum of pharmacological effects largely expanding that of orthosteric ligands. Furthermore, allosteric modulators may show an improved safety profile as compared to orthosteric ligands. Only recently, the explicit search for allosteric modulators has been started for only a few rhodopsin-like GPCRs. The first negative allosteric modulators (allosteric antagonists) of chemokine receptors, maraviroc (CCR5 receptor), used in HIV therapy, and plerixafor (CXCR4 receptor) for stem cell mobilization, have been approved as drugs. The development of allosteric modulators for rhodopsin-like GPCRs as novel drugs is still at an early stage; it appears highly promising.
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Hendricson A, Matchett M, Ferrante M, Ferrante C, Hunnicutt E, Westphal R, Kostich W, Huang Y, Masias N, Hong D, Bertekap R, Burford N, Watson J, Alt A, Myslik J, Zhang L, Knox R. Design of an Automated Enhanced-Throughput Platform for Functional Characterization of Positive Allosteric Modulator-Induced Leftward Shifts in Apparent Agonist Potency In Vitro. ACTA ACUST UNITED AC 2012; 17:104-15. [DOI: 10.1177/2211068211435301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Valant C, Aurelio L, Devine SM, Ashton TD, White JM, Sexton PM, Christopoulos A, Scammells PJ. Synthesis and characterization of novel 2-amino-3-benzoylthiophene derivatives as biased allosteric agonists and modulators of the adenosine A(1) receptor. J Med Chem 2012; 55:2367-75. [PMID: 22315963 DOI: 10.1021/jm201600e] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of novel 2-amino-3-benzoylthiophenes (2A3BTs) were screened using a functional assay of A(1)R mediated phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in intact CHO cells to identify potential agonistic effects as well as the ability to allosterically modulate the activity of the orthosteric agonist, R-PIA. Two derivatives, 8h and 8i, differing only in terms of the absence or presence of an electron-withdrawing group on the benzoyl moiety of the 2A3BT scaffold, were identified as biased allosteric agonists and positive allosteric modulators of agonist function at the adenosine A(1) receptor (A(1)R) in two different functional assays. Our findings indicate that subtle structural variations can promote functionally distinct receptor conformational states.
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Affiliation(s)
- Celine Valant
- Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville VIC 3052, Australia
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Melancon BJ, Hopkins CR, Wood MR, Emmitte KA, Niswender CM, Christopoulos A, Conn PJ, Lindsley CW. Allosteric modulation of seven transmembrane spanning receptors: theory, practice, and opportunities for central nervous system drug discovery. J Med Chem 2012; 55:1445-64. [PMID: 22148748 DOI: 10.1021/jm201139r] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bruce J Melancon
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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Canals M, Lane JR, Wen A, Scammells PJ, Sexton PM, Christopoulos A. A Monod-Wyman-Changeux mechanism can explain G protein-coupled receptor (GPCR) allosteric modulation. J Biol Chem 2012; 287:650-659. [PMID: 22086918 PMCID: PMC3249119 DOI: 10.1074/jbc.m111.314278] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Revised: 11/10/2011] [Indexed: 01/14/2023] Open
Abstract
The Monod-Wyman-Changeux (MWC) model was initially proposed to describe the allosteric properties of regulatory enzymes and subsequently extended to receptors. Yet despite GPCRs representing the largest family of receptors and drug targets, no study has systematically evaluated the MWC mechanism as it applies to GPCR allosteric ligands. We reveal how the recently described allosteric modulator, benzyl quinolone carboxylic acid (BQCA), behaves according to a strict, two-state MWC mechanism at the M1 muscarinic acetylcholine receptor (mAChR). Despite having a low affinity for the M1 mAChR, BQCA demonstrated state dependence, exhibiting high positive cooperativity with orthosteric agonists in a manner that correlated with efficacy but negative cooperativity with inverse agonists. The activity of BQCA was significantly increased at a constitutively active M1 mAChR but abolished at an inactive mutant. Interestingly, BQCA possessed intrinsic signaling efficacy, ranging from near-quiescence to full agonism depending on the coupling efficiency of the chosen intracellular pathway. This latter cellular property also determined the difference in magnitude of positive cooperativity between BQCA and the orthosteric agonist, carbachol, across pathways. The lack of additional, pathway-biased, allosteric modulation by BQCA was confirmed in genetically engineered yeast strains expressing different chimeras between the endogenous yeast G(pa1) protein and human Gα subunits. These findings define a chemical biological framework that can be applied to the study and classification of allosteric modulators across different GPCR families.
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Affiliation(s)
- Meritxell Canals
- Drug Discovery Biology, Medicinal Chemistry, and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - J Robert Lane
- Drug Discovery Biology, Medicinal Chemistry, and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Adriel Wen
- Drug Discovery Biology, Medicinal Chemistry, and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Peter J Scammells
- Drug Discovery Biology, Medicinal Chemistry, and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Patrick M Sexton
- Drug Discovery Biology, Medicinal Chemistry, and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Medicinal Chemistry, and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia.
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Valant C, Robert Lane J, Sexton PM, Christopoulos A. The best of both worlds? Bitopic orthosteric/allosteric ligands of g protein-coupled receptors. Annu Rev Pharmacol Toxicol 2011; 52:153-78. [PMID: 21910627 DOI: 10.1146/annurev-pharmtox-010611-134514] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is now acknowledged that G protein-coupled receptors, the largest class of drug targets, adopt multiple active states that can be preferentially stabilized by orthosteric ligands or allosteric modulators, thus giving rise to the phenomenon of pathway-biased signaling. In the past few years, researchers have begun to explore the potential of linking orthosteric and allosteric pharmacophores to yield bitopic hybrid ligands. This approach is an extension of the more traditional bivalent ligand concept and shares some of the same challenges, including the choice and role of the linker between the two pharmacophores and the validation of mechanism of action. Nonetheless, the promise of bitopic ligands is the generation of novel chemical tools that have improved affinity and/or selectivity profiles. Previously identified functionally selective compounds (and medicines) also may act via a bitopic mechanism, suggesting that the phenomenon is more widespread than currently appreciated.
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Affiliation(s)
- Celine Valant
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia.
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Stallaert W, Christopoulos A, Bouvier M. Ligand functional selectivity and quantitative pharmacology at G protein-coupled receptors. Expert Opin Drug Discov 2011; 6:811-25. [DOI: 10.1517/17460441.2011.586691] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Verzijl D, IJzerman AP. Functional selectivity of adenosine receptor ligands. Purinergic Signal 2011; 7:171-92. [PMID: 21544511 PMCID: PMC3146648 DOI: 10.1007/s11302-011-9232-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 04/05/2011] [Indexed: 12/11/2022] Open
Abstract
Adenosine receptors are plasma membrane proteins that transduce an extracellular signal into the interior of the cell. Basically every mammalian cell expresses at least one of the four adenosine receptor subtypes. Recent insight in signal transduction cascades teaches us that the current classification of receptor ligands into agonists, antagonists, and inverse agonists relies very much on the experimental setup that was used. Upon activation of the receptors by the ubiquitous endogenous ligand adenosine they engage classical G protein-mediated pathways, resulting in production of second messengers and activation of kinases. Besides this well-described G protein-mediated signaling pathway, adenosine receptors activate scaffold proteins such as β-arrestins. Using innovative and sensitive experimental tools, it has been possible to detect ligands that preferentially stimulate the β-arrestin pathway over the G protein-mediated signal transduction route, or vice versa. This phenomenon is referred to as functional selectivity or biased signaling and implies that an antagonist for one pathway may be a full agonist for the other signaling route. Functional selectivity makes it necessary to redefine the functional properties of currently used adenosine receptor ligands and opens possibilities for new and more selective ligands. This review focuses on the current knowledge of functionally selective adenosine receptor ligands and on G protein-independent signaling of adenosine receptors through scaffold proteins.
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Affiliation(s)
- Dennis Verzijl
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
| | - Ad P. IJzerman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
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Fredholm BB, IJzerman AP, Jacobson KA, Linden J, Müller CE. International Union of Basic and Clinical Pharmacology. LXXXI. Nomenclature and classification of adenosine receptors--an update. Pharmacol Rev 2011; 63:1-34. [PMID: 21303899 PMCID: PMC3061413 DOI: 10.1124/pr.110.003285] [Citation(s) in RCA: 1015] [Impact Index Per Article: 78.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the 10 years since our previous International Union of Basic and Clinical Pharmacology report on the nomenclature and classification of adenosine receptors, no developments have led to major changes in the recommendations. However, there have been so many other developments that an update is needed. The fact that the structure of one of the adenosine receptors has recently been solved has already led to new ways of in silico screening of ligands. The evidence that adenosine receptors can form homo- and heteromultimers has accumulated, but the functional significance of such complexes remains unclear. The availability of mice with genetic modification of all the adenosine receptors has led to a clarification of the functional roles of adenosine, and to excellent means to study the specificity of drugs. There are also interesting associations between disease and structural variants in one or more of the adenosine receptors. Several new selective agonists and antagonists have become available. They provide improved possibilities for receptor classification. There are also developments hinting at the usefulness of allosteric modulators. Many drugs targeting adenosine receptors are in clinical trials, but the established therapeutic use is still very limited.
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Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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Jacobson KA, Gao ZG, Göblyös A, IJzerman AP. Allosteric modulation of purine and pyrimidine receptors. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 61:187-220. [PMID: 21586360 PMCID: PMC3165024 DOI: 10.1016/b978-0-12-385526-8.00007-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Among the purine and pyrimidine receptors, the discovery of small molecular allosteric modulators has been most highly advanced for the A(1) and A(3) adenosine receptors (ARs). These AR modulators have allosteric effects that are structurally separated from the orthosteric effects in SAR studies. The benzoylthiophene derivatives tend to act as allosteric agonists as well as selective positive allosteric modulators (PAMs) of the A(1) AR. A 2-amino-3-aroylthiophene derivative T-62 has been under development as a PAM of the A(1) AR for the treatment of chronic pain. Several structurally distinct classes of allosteric modulators of the human A(3) AR have been reported: 3-(2-pyridinyl)isoquinolines, 2,4-disubstituted quinolines, 1H-imidazo-[4,5-c]quinolin-4-amines, endocannabinoid 2-arachidonylglycerol, and the food dye Brilliant Black BN. Site-directed mutagenesis of A(1) and A(3) ARs has identified residues associated with the allosteric effect, distinct from those that affect orthosteric binding. A few small molecular allosteric modulators have been reported for several of the P2X ligand-gated ion channels and the G protein-coupled P2Y receptor nucleotides. Metal ion modulation of the P2X receptors has been extensively explored. The allosteric approach to modulation of purine and pyrimidine receptors looks promising for development of drugs that are event and site specific in action.
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Affiliation(s)
- Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anikó Göblyös
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
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