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Vandeputte MM, Tsai MHM, Chen L, Glatfelter GC, Walther D, Stove CP, Shi L, Baumann MH. Comparative neuropharmacology of structurally distinct non-fentanyl opioids that are appearing on recreational drug markets worldwide. Drug Alcohol Depend 2023; 249:109939. [PMID: 37276825 DOI: 10.1016/j.drugalcdep.2023.109939] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/28/2023] [Accepted: 05/18/2023] [Indexed: 06/07/2023]
Abstract
BACKGROUND The emergence of novel synthetic opioids (NSOs) is contributing to the opioid overdose crisis. While fentanyl analogs have historically dominated the NSO market, a shift towards non-fentanyl compounds is now occurring. METHODS Here, we examined the neuropharmacology of structurally distinct non-fentanyl NSOs, including U-47700, isotonitazene, brorphine, and N-desethyl isotonitazene, as compared to morphine and fentanyl. Compounds were tested in vitro using opioid receptor binding assays in rat brain tissue and by monitoring forskolin-stimulated cAMP accumulation in cells expressing the human mu-opioid receptor (MOR). Compounds were administered subcutaneously to male Sprague-Dawley rats, and hot plate antinociception, catalepsy score, and body temperature changes were measured. RESULTS Receptor binding results revealed high MOR selectivity for all compounds, with MOR affinities comparable to those of morphine and fentanyl (i.e., nM). All drugs acted as full-efficacy MOR agonists in the cyclic AMP assay, but nitazene analogs had greater functional potencies (i.e., pM) compared to the other drugs (i.e., nM). When administered to rats, all compounds induced opioid-like antinociception, catalepsy, and body temperature changes, but nitazenes were the most potent. Similar to fentanyl, the nitazenes had faster onset and decline of in vivo effects when compared to morphine. In vivo potencies to induce antinociception and catalepsy (i.e., ED50s) correlated with in vitro functional potencies (i.e., EC50s) but not binding affinities (i.e., Kis) at MOR. CONCLUSIONS Collectively, our findings indicate that non-fentanyl NSOs pose grave danger to those individuals who use opioids. Continued vigilance is needed to identify and characterize synthetic opioids as they emerge in clandestine drug markets.
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Affiliation(s)
- Marthe M Vandeputte
- Laboratory of Toxicology, Department of Bioanalysis, Ghent University, Ghent, Belgium
| | - Meng-Hua M Tsai
- Computational Chemistry and Molecular Biophysics Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Li Chen
- Computational Chemistry and Molecular Biophysics Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Grant C Glatfelter
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Donna Walther
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Ghent University, Ghent, Belgium
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Michael H Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.
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2
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Cai B, El Daibani A, Bai Y, Che T, Krusemark CJ. Direct Selection of DNA-Encoded Libraries for Biased Agonists of GPCRs on Live Cells. JACS AU 2023; 3:1076-1088. [PMID: 37124302 PMCID: PMC10131204 DOI: 10.1021/jacsau.2c00674] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 05/03/2023]
Abstract
G protein-coupled receptors (GPCRs) are the largest superfamily of human membrane target proteins for approved drugs. GPCR ligands can have a complex array of pharmacological activities. Among these activities, biased agonists have potential to serve as both chemical probes to understand specific aspects of receptor signaling and therapeutic leads with more specific, desired activity. Challenges exist, however, in the development of new biased activators due, in part, to the low throughput of traditional screening approaches. DNA-encoded chemical libraries (DELs) dramatically improve the throughput of drug discovery by allowing a collective selection, rather than discrete screening, of large compound libraries. The use of DELs has been largely limited to affinity-based selections against purified protein targets, which identify binders only. Herein, we report a split protein complementation approach that allows direct identification of DNA-linked molecules that induce the dimerization of two proteins. We used this selection with a DEL against opioid receptor GPCRs on living cells for the identification of small molecules that possess the specific function of activation of either β-arrestin or G protein signaling pathways. This approach was applied to δ-, μ-, and κ-opioid receptors and enabled the discovery of compound [66,66], a selective, G-protein-biased agonist of the κ-opioid receptor (EC50 = 100 nM, E max = 82%, Gi bias factor = 6.6). This approach should be generally applicable for the direct selection of chemical inducers of dimerization from DELs and expand the utility of DELs to enrich molecules with a specific and desired biochemical function.
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Affiliation(s)
- Bo Cai
- Department
of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for
Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
| | - Amal El Daibani
- Center
for Clinical Pharmacology, Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri 63110, United States
| | - Yuntian Bai
- Department
of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for
Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tao Che
- Center
for Clinical Pharmacology, Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri 63110, United States
| | - Casey J. Krusemark
- Department
of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for
Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
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3
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Raynaud P, Gauthier C, Jugnarain V, Jean-Alphonse F, Reiter E, Bruneau G, Crépieux P. Intracellular VHHs to monitor and modulate GPCR signaling. Front Endocrinol (Lausanne) 2022; 13:1048601. [PMID: 36465650 PMCID: PMC9708903 DOI: 10.3389/fendo.2022.1048601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
Single-domain antibody fragments, also known as VHHs or nanobodies, have opened promising avenues in therapeutics and in exploration of intracellular processes. Because of their unique structural properties, they can reach cryptic regions in their cognate antigen. Intracellular VHHs/antibodies primarily directed against cytosolic proteins or transcription factors have been described. In contrast, few of them target membrane proteins and even less recognize G protein-coupled receptors. These receptors are major therapeutic targets, which reflects their involvement in a plethora of physiological responses. Hence, they elicit a tremendous interest in the scientific community and in the industry. Comprehension of their pharmacology has been obscured by their conformational complexity, that has precluded deciphering their structural properties until the early 2010's. To that respect, intracellular VHHs have been instrumental in stabilizing G protein-coupled receptors in active conformations in order to solve their structure, possibly bound to their primary transducers, G proteins or β-arrestins. In contrast, the modulatory properties of VHHs recognizing the intracellular regions of G protein-coupled receptors on the induced signaling network have been poorly studied. In this review, we will present the advances that the intracellular VHHs have permitted in the field of GPCR signaling and trafficking. We will also discuss the methodological hurdles that linger the discovery of modulatory intracellular VHHs directed against GPCRs, as well as the opportunities they open in drug discovery.
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Affiliation(s)
- Pauline Raynaud
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
| | - Camille Gauthier
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
| | - Vinesh Jugnarain
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
| | - Frédéric Jean-Alphonse
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
- Inria, Inria Saclay-Ile-de-France, Palaiseau, France
| | - Eric Reiter
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
- Inria, Inria Saclay-Ile-de-France, Palaiseau, France
| | - Gilles Bruneau
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
| | - Pascale Crépieux
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Institut Français du Cheval et de l’Equitation (IFCE), Université de Tours, Nouzilly, France
- Inria, Inria Saclay-Ile-de-France, Palaiseau, France
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Olson KM, Campbell A, Alt A, Traynor JR. Finding the Perfect Fit: Conformational Biosensors to Determine the Efficacy of GPCR Ligands. ACS Pharmacol Transl Sci 2022; 5:694-709. [PMID: 36110374 PMCID: PMC9469492 DOI: 10.1021/acsptsci.1c00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
G protein-coupled receptors (GPCRs) are highly druggable targets that adopt numerous conformations. A ligand's ability to stabilize specific conformation(s) of its cognate receptor determines its efficacy or ability to produce a biological response. Identifying ligands that produce different receptor conformations and potentially discrete pharmacological effects (e.g., biased agonists, partial agonists, antagonists, allosteric modulators) is a major goal in drug discovery and necessary to develop drugs with better effectiveness and fewer side effects. Fortunately, direct measurements of ligand efficacy, via receptor conformational changes are possible with the recent development of conformational biosensors. In this review, we discuss classical efficacy models, including the two-state model, the ternary-complex model, and multistate models. We describe how nanobody-, transducer-, and receptor-based conformational biosensors detect and/or stabilize specific GPCR conformations to identify ligands with different levels of efficacy. In particular, conformational biosensors provide the potential to identify and/or characterize therapeutically desirable but often difficult to measure conformations of receptors faster and better than current methods. For drug discovery/development, several recent proof-of-principle studies have optimized conformational biosensors for high-throughput screening (HTS) platforms. However, their widespread use is limited by the fact that few sensors are reliably capable of detecting low-frequency conformations and technically demanding assay conditions. Nonetheless, conformational biosensors do help identify desirable ligands such as allosteric modulators, biased ligands, or partial agonists in a single assay, representing a distinct advantage over classical methods.
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Affiliation(s)
- Keith M. Olson
- Department
of Pharmacology and Edward F Domino Research Center, University of Michigan, Ann Arbor, Michigan 48109, United States
- Life
Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Andra Campbell
- Department
of Pharmacology and Edward F Domino Research Center, University of Michigan, Ann Arbor, Michigan 48109, United States
- Life
Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Andrew Alt
- Department
of Pharmacology and Edward F Domino Research Center, University of Michigan, Ann Arbor, Michigan 48109, United States
- Life
Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John R. Traynor
- Department
of Pharmacology and Edward F Domino Research Center, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department
of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, United
States
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5
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Vandeputte MM, Vasudevan L, Stove CP. In vitro functional assays as a tool to study new synthetic opioids at the μ-opioid receptor: Potential, pitfalls and progress. Pharmacol Ther 2022; 235:108161. [DOI: 10.1016/j.pharmthera.2022.108161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/30/2022] [Accepted: 02/14/2022] [Indexed: 10/19/2022]
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6
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Laeremans T, Sands ZA, Claes P, De Blieck A, De Cesco S, Triest S, Busch A, Felix D, Kumar A, Jaakola VP, Menet C. Accelerating GPCR Drug Discovery With Conformation-Stabilizing VHHs. Front Mol Biosci 2022; 9:863099. [PMID: 35677880 PMCID: PMC9170359 DOI: 10.3389/fmolb.2022.863099] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/22/2022] [Indexed: 01/19/2023] Open
Abstract
The human genome encodes 850 G protein-coupled receptors (GPCRs), half of which are considered potential drug targets. GPCRs transduce extracellular stimuli into a plethora of vital physiological processes. Consequently, GPCRs are an attractive drug target class. This is underlined by the fact that approximately 40% of marketed drugs modulate GPCRs. Intriguingly 60% of non-olfactory GPCRs have no drugs or candidates in clinical development, highlighting the continued potential of GPCRs as drug targets. The discovery of small molecules targeting these GPCRs by conventional high throughput screening (HTS) campaigns is challenging. Although the definition of success varies per company, the success rate of HTS for GPCRs is low compared to other target families (Fujioka and Omori, 2012; Dragovich et al., 2022). Beyond this, GPCR structure determination can be difficult, which often precludes the application of structure-based drug design approaches to arising HTS hits. GPCR structural studies entail the resource-demanding purification of native receptors, which can be challenging as they are inherently unstable when extracted from the lipid matrix. Moreover, GPCRs are flexible molecules that adopt distinct conformations, some of which need to be stabilized if they are to be structurally resolved. The complexity of targeting distinct therapeutically relevant GPCR conformations during the early discovery stages contributes to the high attrition rates for GPCR drug discovery programs. Multiple strategies have been explored in an attempt to stabilize GPCRs in distinct conformations to better understand their pharmacology. This review will focus on the use of camelid-derived immunoglobulin single variable domains (VHHs) that stabilize disease-relevant pharmacological states (termed ConfoBodies by the authors) of GPCRs, as well as GPCR:signal transducer complexes, to accelerate drug discovery. These VHHs are powerful tools for supporting in vitro screening, deconvolution of complex GPCR pharmacology, and structural biology purposes. In order to demonstrate the potential impact of ConfoBodies on translational research, examples are presented of their role in active state screening campaigns and structure-informed rational design to identify de novo chemical space and, subsequently, how such matter can be elaborated into more potent and selective drug candidates with intended pharmacology.
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7
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Jullié D, Valbret Z, Stoeber M. Optical tools to study the subcellular organization of GPCR neuromodulation. J Neurosci Methods 2021; 366:109408. [PMID: 34763022 DOI: 10.1016/j.jneumeth.2021.109408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/11/2021] [Accepted: 11/03/2021] [Indexed: 12/29/2022]
Abstract
Modulation of neuronal circuit activity is key to information processing in the brain. G protein-coupled receptors (GPCRs), the targets of most neuromodulatory ligands, show extremely diverse expression patterns in neurons and receptors can be localized in various sub-neuronal membrane compartments. Upon activation, GPCRs promote signaling cascades that alter the level of second messengers, drive phosphorylation changes, modulate ion channel function, and influence gene expression, all of which critically impact neuron physiology. Because of its high degree of complexity, this form of interneuronal communication has remained challenging to integrate into our conceptual understanding of brain function. Recent technological advances in fluorescence microscopy and the development of optical biosensors now allow investigating neuromodulation with unprecedented resolution on the level of individual cells. In this review, we will highlight recent imaging techniques that enable determining the precise localization of GPCRs in neurons, with specific focus on the subcellular and nanoscale level. Downstream of receptors, we describe novel conformation-specific biosensors that allow for real-time monitoring of GPCR activation and of distinct signal transduction events in neurons. Applying these new tools has the potential to provide critical insights into the function and organization of GPCRs in neuronal cells and may help decipher the molecular and cellular mechanisms that underlie neuromodulation.
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Affiliation(s)
- Damien Jullié
- Department of Psychiatry, University of California San Francisco, San Francisco, USA.
| | - Zoé Valbret
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Miriam Stoeber
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland.
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