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Jobe A, Vijayan R. Orphan G protein-coupled receptors: the ongoing search for a home. Front Pharmacol 2024; 15:1349097. [PMID: 38495099 PMCID: PMC10941346 DOI: 10.3389/fphar.2024.1349097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/15/2024] [Indexed: 03/19/2024] Open
Abstract
G protein-coupled receptors (GPCRs) make up the largest receptor superfamily, accounting for 4% of protein-coding genes. Despite the prevalence of such transmembrane receptors, a significant number remain orphans, lacking identified endogenous ligands. Since their conception, the reverse pharmacology approach has been used to characterize such receptors. However, the multifaceted and nuanced nature of GPCR signaling poses a great challenge to their pharmacological elucidation. Considering their therapeutic relevance, the search for native orphan GPCR ligands continues. Despite limited structural input in terms of 3D crystallized structures, with advances in machine-learning approaches, there has been great progress with respect to accurate ligand prediction. Though such an approach proves valuable given that ligand scarcity is the greatest hurdle to orphan GPCR deorphanization, the future pairings of the remaining orphan GPCRs may not necessarily take a one-size-fits-all approach but should be more comprehensive in accounting for numerous nuanced possibilities to cover the full spectrum of GPCR signaling.
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Affiliation(s)
- Amie Jobe
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ranjit Vijayan
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
- The Big Data Analytics Center, United Arab Emirates University, Al Ain, United Arab Emirates
- Zayed Bin Sultan Center for Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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2
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Coussot G, Le Postollec A, Delbecq S, Dobrijevic M. Freeze-drying of few microliters of antibody formulations to implement 384-wells homogeneous instant assays. Anal Chim Acta 2023; 1277:341660. [PMID: 37604613 DOI: 10.1016/j.aca.2023.341660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/03/2023] [Accepted: 07/25/2023] [Indexed: 08/23/2023]
Abstract
Enzyme-linked immunosorbent assay protocols have traditionally complex workflows with several intensive wash steps. Analytical tools with both shorter time-to-result and hands-on-time using smaller sample and assays reagents volumes are now investigated. In this context, fluorescence resonance energy transfer (FRET)-based assays are emerging as one of the most promising analytical tools in high-throughput screening (HTS). These immunoassays allow fast quantification of antigens at the nano-gram level in a final assay volume of only a few μL. We used a homogeneous time-resolved FRET (called HTRF) assay to develop a freeze-dried screening and ready-to-use format with only one rehydration step called "instant assay". To assure optimal performance of the developed homogeneous instant assay, we investigated the critical quality attributes by studying the functionality and stability of the critical reagents and fluorophores. The cyclic adenosine 3'-5'-monophosphate (cAMP) was selected as the antigen target. We tested various formulations (with different buffers, sugars, bulking reagents, surfactants and co-solvants) combined with a slow freezing and the use of an aluminium plate holder during the freeze-drying of few microliter of bioreagents. The optimized freeze-drying procedure permits to preserve more than 70% of Ab recognition properties. The developed off-the-shelf homogeneous FRET immunoassay allows direct and fast quantification of cAMP at a nanogram level.
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Affiliation(s)
- G Coussot
- Faculté des Sciences Pharmaceutiques et Biologiques, Université de Montpellier, 15 Avenue Charles Flahault, 34090, Montpellier, France.
| | - A Le Postollec
- Laboratoire d'astrophysique de Bordeaux (LAB), CNRS UMR 5804, Université de Bordeaux, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France
| | - S Delbecq
- Centre de Biologie Structurale (CBS), INSERM U1054, CNRS UMR 5048, Université de Montpellier, 34090, Montpellier, France
| | - M Dobrijevic
- Laboratoire d'astrophysique de Bordeaux (LAB), CNRS UMR 5804, Université de Bordeaux, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France
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3
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Quantitative Determination and Imaging of Gα q Signaling in Live Cells via Split-Luciferase Complementation. Methods Mol Biol 2021. [PMID: 34050463 DOI: 10.1007/978-1-0716-1258-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
G Protein-coupled receptors (GPCRs) transduce signals elicited by bioactive chemical agents (ligands), such as hormones, neurotransmitters, or cytokines, across the cellular membrane. Upon ligand binding, the receptor undergoes structural rearrangements, which cause the activation of G proteins. This triggers the activation of signaling cascades involving amplification, which takes place after every stage of the cascade. Consequently, signals from early stages can be masked when the activation of the signaling cascade is probed remote (distal) from the receptor. This led to the development of several techniques, which probe the activation of such signaling cascades as proximal to the receptor as possible. However, these methods often require specialized equipment or are limited in throughput. By applying split-luciferase complementation to the interaction between the Gαq protein and its effector the phospholipase C-β3 (PLC-β3), we introduce a protocol with a conventional plate reader at high throughput. The method is applicable to live cells and additionally allows imaging of the probe by bioluminescence microscopy.
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4
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Pottel J, Armstrong D, Zou L, Fekete A, Huang XP, Torosyan H, Bednarczyk D, Whitebread S, Bhhatarai B, Liang G, Jin H, Ghaemi SN, Slocum S, Lukacs KV, Irwin JJ, Berg EL, Giacomini KM, Roth BL, Shoichet BK, Urban L. The activities of drug inactive ingredients on biological targets. Science 2020; 369:403-413. [PMID: 32703874 DOI: 10.1126/science.aaz9906] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 05/18/2020] [Indexed: 12/22/2022]
Abstract
Excipients, considered "inactive ingredients," are a major component of formulated drugs and play key roles in their pharmacokinetics. Despite their pervasiveness, whether they are active on any targets has not been systematically explored. We computed the likelihood that approved excipients would bind to molecular targets. Testing in vitro revealed 25 excipient activities, ranging from low-nanomolar to high-micromolar concentration. Another 109 activities were identified by testing against clinical safety targets. In cellular models, five excipients had fingerprints predictive of system-level toxicity. Exposures of seven excipients were investigated, and in certain populations, two of these may reach levels of in vitro target potency, including brain and gut exposure of thimerosal and its major metabolite, which had dopamine D3 receptor dissociation constant K d values of 320 and 210 nM, respectively. Although most excipients deserve their status as inert, many approved excipients may directly modulate physiologically relevant targets.
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Affiliation(s)
- Joshua Pottel
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - Duncan Armstrong
- Preclinical Safety, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Ling Zou
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
| | - Alexander Fekete
- Preclinical Safety, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Xi-Ping Huang
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27759, USA
| | - Hayarpi Torosyan
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - Dallas Bednarczyk
- PK Sciences, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Steven Whitebread
- Preclinical Safety, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Barun Bhhatarai
- PK Sciences, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Guiqing Liang
- PK Sciences, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Hong Jin
- Preclinical Safety, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - S Nassir Ghaemi
- Translational Medicine, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA.,Tufts University School of Medicine, Boston, MA 02111, USA.,Harvard Medical School, Boston, MA 02115, USA
| | - Samuel Slocum
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27759, USA
| | - Katalin V Lukacs
- National Heart and Lung Institute, Imperial College, London SW7 2AZ, UK
| | - John J Irwin
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - Ellen L Berg
- Eurofins, DiscoverX, South San Francisco, CA 94080, USA
| | - Kathleen M Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27759, USA
| | - Brian K Shoichet
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA.
| | - Laszlo Urban
- Preclinical Safety, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA.
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5
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Renner S, Bergsdorf C, Bouhelal R, Koziczak-Holbro M, Amati AM, Techer-Etienne V, Flotte L, Reymann N, Kapur K, Hoersch S, Oakeley EJ, Schuffenhauer A, Gubler H, Lounkine E, Farmer P. Gene-signature-derived IC 50s/EC 50s reflect the potency of causative upstream targets and downstream phenotypes. Sci Rep 2020; 10:9670. [PMID: 32541899 PMCID: PMC7295968 DOI: 10.1038/s41598-020-66533-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/19/2020] [Indexed: 02/02/2023] Open
Abstract
Multiplexed gene-signature-based phenotypic assays are increasingly used for the identification and profiling of small molecule-tool compounds and drugs. Here we introduce a method (provided as R-package) for the quantification of the dose-response potency of a gene-signature as EC50 and IC50 values. Two signaling pathways were used as models to validate our methods: beta-adrenergic agonistic activity on cAMP generation (dedicated dataset generated for this study) and EGFR inhibitory effect on cancer cell viability. In both cases, potencies derived from multi-gene expression data were highly correlated with orthogonal potencies derived from cAMP and cell growth readouts, and superior to potencies derived from single individual genes. Based on our results we propose gene-signature potencies as a novel valid alternative for the quantitative prioritization, optimization and development of novel drugs.
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Affiliation(s)
- Steffen Renner
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland.
| | - Christian Bergsdorf
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland
| | - Rochdi Bouhelal
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland
| | | | - Andrea Marco Amati
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland.,Department of Chemistry & Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Valerie Techer-Etienne
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland
| | | | - Nicole Reymann
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland
| | | | | | | | - Ansgar Schuffenhauer
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland
| | | | - Eugen Lounkine
- Chemical Biology & Therapeutics, NIBR, 181 Massachusetts Avenue, Cambridge, MA, 02139, USA.,Modeling and Informatics, Merck & Co., Inc., 33 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - Pierre Farmer
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research (NIBR), Basel, 4056, Switzerland.
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6
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Maity C, Ghosh D, Guha S. Assays for Intracellular Cyclic Adenosine Monophosphate (cAMP) and Lysosomal Acidification. Methods Mol Biol 2020; 1996:161-178. [PMID: 31127555 DOI: 10.1007/978-1-4939-9488-5_14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cyclic adenosine monophosphate (3',5'-cAMP) is a multifunctional second messenger which controls extremely diverse and physiologically important biochemical pathways. Among its myriad roles, 3',5'-cAMP functions as an intracellular regulator of lysosomal pH, which is essential for the activity of acidic lysosomal enzymes. Defects in lysosomal acidification are attributed to many diseases like macular degeneration, Parkinson's, Alzheimer's, and cystic fibrosis. Strategic re-acidification of defective lysosomes by pharmacological increase of intracellular cAMP offers exciting therapeutic potential in these diseases. Modular assays for accurate assessment of intracellular cAMP and lysosomal pH are a critical component of this research. We describe label-free targeted metabolomics for quantitating intracellular cAMP and integrated assays for measuring lysosomal pH. These hybrid assays offer fast, unbiased information on intracellular cAMP concentrations and lysosomal pH that can be applied to many cell types and putative drug screening strategies.
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Affiliation(s)
- Chiranjit Maity
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Dipankar Ghosh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Sonia Guha
- Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA.
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7
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Zhou H, Peng X, Hou T, Zhao N, Qiu M, Zhang X, Liang X. Identification of novel phytocannabinoids from Ganoderma by label-free dynamic mass redistribution assay. JOURNAL OF ETHNOPHARMACOLOGY 2020; 246:112218. [PMID: 31494202 DOI: 10.1016/j.jep.2019.112218] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/15/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Located throughout the body, cannabinoid receptors (CB1 and CB2) are therapeutic targets for obesity/metabolic diseases, neurological/mental disorders, and immune modulation. Phytocannabinoids are greatly important for the development of new medicines with high efficacy and/or minor side effects. Plants and fungi are used in traditional medicine for beneficial effects to mental and immune system. The current research studied five fungi from the genus Ganoderma and five plants: Ganoderma hainanense J.D. Zhao, L.W. Hsu & X.Q. Zhang; Ganoderma capense (Lloyd) Teng, Zhong Guo De Zhen Jun; Ganoderma cochlear (Blume & T. Nees) Bres., Hedwigia; Ganoderma resinaceum Boud.; Ganoderma applanatum (Pers.) Pat.; Carthamus tinctorius L. (Compositae); Cynanchum otophyllum C. K. Schneid. (Asclepiadaceae); Coffea arabica L. (Rubiaceae); Prinsepia utilis Royle (Rosaceae); Lepidium meyenii Walp. (Brassicaceae). They show immunoregulation, promotion of longevity and maintenance of vitality, stimulant effects on the central nervous system, hormone balance and other beneficial effects. However, it remains unclear whether cannabinoid receptors are involved in these effects. AIM OF THE STUDY This work aimed to identify components working on CB1 and CB2 from the above plants and fungi, as novel phytocannabinoids, and to investigate mechanisms of how these compounds affected the cells. By analyzing the structure-activity relationship, we could identify the core structure for future development. MATERIALS AND METHODS Eighty-two natural compounds were screened on stably transfected Chinese hamster ovary (CHO) cell lines, CHO-CB1 and CHO-CB2, with application of a label-free dynamic mass redistribution (DMR) technology that measured cellular responses to compounds. CP55,940 and WIN55,212-2 were agonist probe molecules, and SR141716A and SR144528 were antagonist probes. Pertussis toxin, cholera toxin, LY294002 and U73122 were signaling pathway inhibitors. The DMR data were acquired by Epic Imager software (Corning, NY), processed by Imager Beta 3.7 (Corning), and analyzed by GraphPad Prism 6 (GraphPad Software, San Diego, CA). RESULTS Transfected CHO-CB1 and CHO-CB2 cell lines were established and characterized. Seven compounds induced responses/activities in the cells. Among the seven compounds, four were purified from two Ganoderma species with potencies between 20 and 35 μM. Three antagonists: Kfb68 antagonized both receptors with a better desensitizing effect on CB2 to WIN55,212-2 over CP55,940. Kga1 and Kfb28 were antagonists selective to CB1 and CB2, respectively. Kfb77 was a special agonist and it stimulated CB1 in a mechanism different from that of CP55,940. Another three active compounds, derived from the Lepidium meyenii Walp. (Brassicaceae), were also identified but their effects were mediated through mechanisms much related to the signaling transduction pathways, especially through the stimulatory Gs protein. CONCLUSIONS We identified four natural cannabinoids that exhibited structural and functional diversities. Our work confirms the presence of active ingredients in the Ganoderma species to CB1 and CB2, and this finding establishes connections between the fungi and the cannabinoid receptors, which will serve as a starting point to connect their beneficial effects to the endocannabinoid system. This research will also enrich the inventory of cannabinoids and phytocannabinoids from fungi. Yet due to some limitations, further structure-activity relationship studies and mechanism investigation are warranted in future.
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Affiliation(s)
- Han Zhou
- Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Xingrong Peng
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
| | - Tao Hou
- Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Nan Zhao
- Pharmacology Department, University College London, London, WC1E 6BT, UK.
| | - Minghua Qiu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
| | - Xiuli Zhang
- Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China; College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.
| | - Xinmiao Liang
- Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
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8
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Ayukawa K, Suzuki C, Ogasawara H, Kinoshita T, Furuno M, Suzuki G. Development of a High-Throughput Screening-Compatible Assay for Discovery of GPR3 Inverse Agonists Using a cAMP Biosensor. SLAS DISCOVERY 2019; 25:287-298. [PMID: 31516076 DOI: 10.1177/2472555219875101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
While G-protein-coupled receptors (GPCRs) represent the largest class of cell surface proteins, there are ≥100 orphan GPCRs whose endogenous ligands are unknown. Accordingly, these could prove to be potential therapeutic targets for the pharmaceutical intervention of various diseases. Constitutively active orphan GPCRs are activated without ligands; thus, inverse agonists may be very useful pharmacological tools for inhibiting constitutive activity. However, in general, inverse agonist screening is considered more difficult to perform with high quality than antagonist screening, particularly due to the narrow assay window. We developed a high-throughput screening (HTS)-compatible assay to identify inverse agonists of GPR3. GPR3 is expressed in the central nervous system (CNS) and is known to be related to Alzheimer's disease and other CNS diseases. The GPR3 inducible cell line was established using T-REx 293 cells that stably expressed the tetracycline repressor protein, and the cAMP biosensor, GloSensor, was stably co-expressed. After optimization of the induction level of GPR3 and assay conditions, the GloSensor assay showed an approximately 20-fold signal-to-background ratio and high sensitivity. Using the HTS method, we successfully screened a library of hundreds of thousands of compounds for the inhibition of constitutive activity with good quality and excellent reproducibility. Finally, 35 compounds were identified as GPR3 selective inverse agonists. This inverse agonist screening approach using GloSensor in combination with the inducible expression of orphan GPCR indicates universal applicability to the search for inverse agonists of constitutively active orphan GPCRs.
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Affiliation(s)
- Kumiko Ayukawa
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka, Japan
| | - Chie Suzuki
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka, Japan
| | - Hiroyuki Ogasawara
- Pharmaceutical Frontier Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Kanazawa-ku, Yokohama, Kanagawa, Japan
| | - Tomomi Kinoshita
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka, Japan
| | - Masahiro Furuno
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka, Japan
| | - Gentaroh Suzuki
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka, Japan
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9
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Li F, Jiang X, Luo LL, Xu YM, Huang XX, Huang C, Zhang Y. A piggyBac-based TANGO GFP assay for high throughput screening of GPCR ligands in live cells. Cell Commun Signal 2019; 17:49. [PMID: 31122241 PMCID: PMC6533772 DOI: 10.1186/s12964-019-0359-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/01/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND GPCRs are considered essential for various physiological processes and have been the most productive drug targets. Therefore, development of the methods of GPCR ligands screening is a high priority for pharmaceutical industries and research institutions. METHODS We developed a potential method (piggyBac-TANGO) based on the TANGO and PRESTO-TANGO assays. The system was optimized with a piggyBac transposon as a transgene vehicle, and eGFP was used as a reporter instead of luciferase. The assay was validated in the HEK 293T and U87-MG cell lines and antagonist activities of the compounds were assessed. The transgene copy number and long-term stability were evaluated by qPCR. Then, we performed a DRD2-targeted screening for natural products using the piggyBac-TANGO assay. RESULTS The validation assay showed that using the piggyBac transposon as a transgene vehicle produced high signal-to-background ratio and stable readout confirmed by investigation of the transgene copy number and long-term stability. Use of eGFP instead of luciferase as a reporter enabled to create a high throughput system suitable for live cells. Moreover, the piggyBac-TANGO assay permitted versatile detection of antagonist activity of compounds and was not limited to a particular cell type. With the use of the piggyBac-TANGO assay, we have successfully identified a novel agonist of DRD2. CONCLUSION Thus, the results indicate that the piggyBac-TANGO method is a user-friendly, robust and imaging-based assay that provides a novel approach to high throughput GPCR-targeted ligand screening and drug development.
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Affiliation(s)
- Fei Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.,School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xi Jiang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ling-Ling Luo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yue-Ming Xu
- iHuman Institute, ShanghaiTech University, Shanghai, China
| | - Xing-Xu Huang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Cheng Huang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Yu Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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10
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Engelhardt B, Holze J, Elliott C, Baillie GS, Kschischo M, Fröhlich H. Modelling and mathematical analysis of the M$_{2}$ receptor-dependent joint signalling and secondary messenger network in CHO cells. MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA 2018; 35:279-297. [PMID: 28505258 DOI: 10.1093/imammb/dqx003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 02/07/2017] [Indexed: 11/14/2022]
Abstract
The muscarinic M$_{2}$ receptor is a prominent member of the GPCR family and strongly involved in heart diseases. Recently published experimental work explored the cellular response to iperoxo-induced M$_{2}$ receptor stimulation in Chinese hamster ovary (CHO) cells. To better understand these responses, we modelled and analysed the muscarinic M$_{2}$ receptor-dependent signalling pathway combined with relevant secondary messenger molecules using mass action. In our literature-based joint signalling and secondary messenger model, all binding and phosphorylation events are explicitly taken into account in order to enable subsequent stoichiometric matrix analysis. We propose constraint flux sampling (CFS) as a method to characterize the expected shift of the steady state reaction flux distribution due to the known amount of cAMP production and PDE4 activation. CFS correctly predicts an experimentally observable influence on the cytoskeleton structure (marked by actin and tubulin) and in consequence a change of the optical density of cells. In a second step, we use CFS to simulate the effect of knock-out experiments within our biological system, and thus to rank the influence of individual molecules on the observed change of the optical cell density. In particular, we confirm the relevance of the protein RGS14, which is supported by current literature. A combination of CFS with Elementary Flux Mode analysis enabled us to determine the possible underlying mechanism. Our analysis suggests that mathematical tools developed for metabolic network analysis can also be applied to mixed secondary messenger and signalling models. This could be very helpful to perform model checking with little effort and to generate hypotheses for further research if parameters are not known.
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Affiliation(s)
- Benjamin Engelhardt
- Algorithmic Bioinformatics, Bonn-Aachen International Center for IT, Rheinische Friedrich-Wilhelms-Universität Bonn, Dahlmannstr. 2, Bonn, Germany and DFG Research Training Group 1873
| | - Janine Holze
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 3, Bonn, Germany
| | - Christina Elliott
- Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - George S Baillie
- College of Medical, Veterinary and Life Sciences, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Maik Kschischo
- Department of Mathematics and Technology, RheinAhrCampus, University of Applied Sciences Koblenz, Joseph-Rovan-Allee 2, Remagen, Germany
| | - Holger Fröhlich
- Algorithmic Bioinformatics, Bonn-Aachen International Center for IT, Rheinische Friedrich-Wilhelms-Universität Bonn, Dahlmannstr. 2, Bonn, Germany
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11
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Huang X, Schmidt TA, Shortt C, Arora S, Asari A, Kirsch T, Cowman MK. A competitive alphascreen assay for detection of hyaluronan. Glycobiology 2018; 28:137-147. [PMID: 29300896 DOI: 10.1093/glycob/cwx109] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 12/21/2017] [Indexed: 11/12/2022] Open
Abstract
A method for specific quantification of hyaluronan (HA) concentration using AlphaScreen® (Amplified Luminescent Proximity Homogeneous Assay) technology is described. Two types of hydrogel-coated and chromophore-loaded latex nanobeads are employed. The proximity of the beads in solution is detected by excitation of the donor bead leading to the production of singlet oxygen, and chemiluminescence from the acceptor bead upon exposure to singlet oxygen. In the HA assay, the donor bead is modified with streptavidin, and binds biotin-labeled HA. The acceptor bead is modified with Ni(II), and is used to bind a specific recombinant HA-binding protein (such as HABP; aggrecan G1-IGD-G2) with a His-tag. Competitive inhibition of the HA-HABP interaction by free unlabeled HA in solution is used for quantification. The assay is specific for HA, and not dependent on HA molecular mass above the decasaccharide. HA can be quantified over a concentration range of approximately 30-1600 ng/mL using 2.5 μL of sample, for a detectable mass range of approximately 0.08-4 ng HA. This sensitivity of the AlphaScreen assay is greater than existing ELISA-like methods, due to the small volume requirements. HA can be detected in biological fluids using the AlphaScreen assay, after removal of bound proteins from HA and dilution or removal of other interfering proteins and lipids.
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Affiliation(s)
- Xiayun Huang
- Department of Chemical and Biomolecular Engineering, New York University Tandon School of Engineering, 433 First Avenue, New York, NY 10010, USA
| | - Tannin A Schmidt
- Biomedical Engineering Department, School of Dental Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Claire Shortt
- Department of Orthopedic Surgery, New York University School of Medicine, 433 First Avenue, New York, NY 10010, USA
| | - Shivani Arora
- Department of Chemical and Biomolecular Engineering, New York University Tandon School of Engineering, 433 First Avenue, New York, NY 10010, USA
| | - Akira Asari
- Hyaluronan Research Institute, Inc. 2-5-8-1001, Nihonbashimuromachi, Chuo-ku, Tokyo 103-0022,Japan
| | - Thorsten Kirsch
- Department of Orthopedic Surgery, New York University School of Medicine, 433 First Avenue, New York, NY 10010, USA
| | - Mary K Cowman
- Department of Chemical and Biomolecular Engineering, New York University Tandon School of Engineering, 433 First Avenue, New York, NY 10010, USA
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12
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Morales P, Goya P, Jagerovic N. Emerging strategies targeting CB 2 cannabinoid receptor: Biased agonism and allosterism. Biochem Pharmacol 2018; 157:8-17. [PMID: 30055149 DOI: 10.1016/j.bcp.2018.07.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/23/2018] [Indexed: 01/24/2023]
Abstract
During these last years, the CB2 cannabinoid receptor has emerged as a potential anti-inflammatory target in diseases such as multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, ischemic stroke, autoimmune diseases, osteoporosis, and cancer. However, the development of clinically useful CB2 agonists reveals to be very challenging. Allosterism and biased-signaling mechanisms at CB2 receptor may offer new avenues for the development of improved CB2 receptor-targeted therapies. Although there has been some exploration of CB1 receptor activation by new CB1 allosteric or biased-signaling ligands, the CB2 receptor is still at initial stages in this domain. In an effort to understand the molecular basis behind these pharmacological approaches, we have analyzed and summarized the structural data reported so far at CB2 receptor.
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Affiliation(s)
- Paula Morales
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Unidad Asociada I+D+i IQM/Universidad Rey Juan Carlos (URJC), Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Pilar Goya
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Unidad Asociada I+D+i IQM/Universidad Rey Juan Carlos (URJC), Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Nadine Jagerovic
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Unidad Asociada I+D+i IQM/Universidad Rey Juan Carlos (URJC), Calle Juan de la Cierva, 3, E-28006 Madrid, Spain.
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13
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Gonçalves JPL, Palmer D, Meldal M. MC4R Agonists: Structural Overview on Antiobesity Therapeutics. Trends Pharmacol Sci 2018; 39:402-423. [PMID: 29478721 DOI: 10.1016/j.tips.2018.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 01/08/2023]
Abstract
The melanocortin-4 receptor (MC4R) regulates adipose tissue formation and energy homeostasis, and is believed to be a monogenic target for novel antiobesity therapeutics. Several research efforts targeting this receptor have identified potent and selective agonists. While viable agonists have been characterized in vitro, undesirable side effects frequently appeared during clinical trials. The most promising candidates have diverse structures, including linear peptides, cyclic peptides, and small molecules. Herein, we present a compilation of potent MC4R agonists and discuss the pivotal structural differences within those molecules that resulted in good selectivity for MC4R over other melanocortins. We provide insight on recent progress in the field and reflect on directions for development of new agonists.
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Affiliation(s)
- Juliana Pereira Lopes Gonçalves
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
| | - Daniel Palmer
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Morten Meldal
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
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14
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Song HP, Wang H, Zhao X, He L, Zhong H, Wu SQ, Li P, Yang H. Label-free pharmacological profiling based on dynamic mass redistribution for characterization and authentication of hazardous natural products. JOURNAL OF HAZARDOUS MATERIALS 2017; 333:265-274. [PMID: 28364689 DOI: 10.1016/j.jhazmat.2017.03.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 03/10/2017] [Accepted: 03/11/2017] [Indexed: 06/07/2023]
Abstract
Natural products are becoming increasingly popular in multiple fields involving medicines, foods and beverages. However, due to the frequent occurrence of poisoning incidents, their toxicity and safety have caused a serious concern. Here we report a method of biosensor-based two-phase pharmacological profiling (BTPP) for discovery, monitor and control of receptor-targeted natural products. BTPP uses a resonant waveguide grating biosensor for label-free and non-invasive detection of intracellular dynamic mass redistribution (DMR), a phenomenon caused by protein relocalization after receptors receiving stimulation from toxicants. The method can not only facilitate the identification of hazardous materials but also quantify their bioactivity by EC50. As a proof of concept, the method was successfully applied to recognize Daturae Flos (DF), an herb that can antagonize muscarinic acetylcholine M2 receptor and further cause poisoning, from other easily confused species. BTPP combined with high performance liquid chromatography revealed that scopolamine and hyoscyamine in DF were the key marker compounds. Moreover, the method accurately picked out 2 M2 receptor antagonists from 25 natural compounds, displaying its potential in high-throughput screening. This study provides a systematic illustration about the establishment, applicability and advantages of BTPP, which contributes to the safety assessment of natural products in related fields.
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Affiliation(s)
- Hui-Peng Song
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Hong Wang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Xiaoai Zhao
- Department of Genetics, Stanford University, Stanford, CA 94305 USA
| | - Ling He
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
| | - Huailing Zhong
- U-Pharm Laboratories LLC, 239 New Rd, Suite A-107, Parsippany, NJ 07054 USA
| | - Si-Qi Wu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Ping Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| | - Hua Yang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
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15
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Evadé L, Dausse E, Taouji S, Daguerre E, Chevet E, Toulmé JJ. Aptamer-mediated nanoparticle interactions: from oligonucleotide-protein complexes to SELEX screens. Methods Mol Biol 2016; 1297:153-67. [PMID: 25896002 DOI: 10.1007/978-1-4939-2562-9_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Aptamers are oligonucleotides displaying specific binding properties for a predetermined target. They can be easily immobilized on various surfaces such as nanoparticles. Functionalized particles can then be used to various aims. We took advantage of the AlphaScreen(®) technology for monitoring aptamer-mediated interactions. A particle bearing an aptamer contains a photosensitizer whereas another type of particle contains a chemiluminescer. Irradiation causes the formation of singlet oxygen species in the photosensitizer-containing bead that in turn activates the chemiluminescer. Luminescence emission can be observed if the two types of beads are in close proximity (<200 nm). This is achieved when the cognate ligand of the aptamer is grafted onto the chemiluminescer-containing bead. Using this technology we have screened oligonucleotide libraries and monitored aptamer-protein interactions. This constitutes the basis for aptamer-based analytical assays.
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Affiliation(s)
- Laetitia Evadé
- Novaptech, European Institute of Chemistry and Biology, Pessac, France
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16
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Vacchini A, Busnelli M, Chini B, Locati M, Borroni EM. Analysis of G Protein and β-Arrestin Activation in Chemokine Receptors Signaling. Methods Enzymol 2016; 570:421-40. [DOI: 10.1016/bs.mie.2015.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Yao XQ, Malik RU, Griggs NW, Skjærven L, Traynor JR, Sivaramakrishnan S, Grant BJ. Dynamic Coupling and Allosteric Networks in the α Subunit of Heterotrimeric G Proteins. J Biol Chem 2015; 291:4742-53. [PMID: 26703464 DOI: 10.1074/jbc.m115.702605] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Indexed: 12/21/2022] Open
Abstract
G protein α subunits cycle between active and inactive conformations to regulate a multitude of intracellular signaling cascades. Important structural transitions occurring during this cycle have been characterized from extensive crystallographic studies. However, the link between observed conformations and the allosteric regulation of binding events at distal sites critical for signaling through G proteins remain unclear. Here we describe molecular dynamics simulations, bioinformatics analysis, and experimental mutagenesis that identifies residues involved in mediating the allosteric coupling of receptor, nucleotide, and helical domain interfaces of Gαi. Most notably, we predict and characterize novel allosteric decoupling mutants, which display enhanced helical domain opening, increased rates of nucleotide exchange, and constitutive activity in the absence of receptor activation. Collectively, our results provide a framework for explaining how binding events and mutations can alter internal dynamic couplings critical for G protein function.
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Affiliation(s)
- Xin-Qiu Yao
- From the Department of Computational Medicine and Bioinformatics
| | - Rabia U Malik
- Cell and Developmental Biology, and the Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | | | - Lars Skjærven
- the Department of Biomedicine, University of Bergen, 5020 Bergen, Norway, and
| | - John R Traynor
- Pharmacology, University of Michigan, Ann Arbor, Michigan 48109
| | - Sivaraj Sivaramakrishnan
- the Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Barry J Grant
- From the Department of Computational Medicine and Bioinformatics,
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18
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Abstract
Since their discovery, G protein-coupled receptors (GPCRs) constitute one of the most studied proteins leading to important discoveries and perspectives in terms of their biology and implication in physiology and pathophysiology. This is mostly linked to the remarkable advances in the development and application of the biophysical resonance energy transfer (RET)-based approaches, including bioluminescence and fluorescence resonance energy transfer (BRET and FRET, respectively). Indeed, BRET and FRET have been extensively applied to study different aspects of GPCR functioning such as their activation and regulation either statically or dynamically, in real-time and intact cells. Consequently, our view on GPCRs has considerably changed opening new challenges for the study of GPCRs in their native tissues in the aim to get more knowledge on how these receptors control the biological responses. Moreover, the technological aspect of this field of research promises further developments for robust and reliable new RET-based assays that may be compatible with high-throughput screening as well as drug discovery programs.
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Affiliation(s)
- Mohammed Akli Ayoub
- Biologie et Bioinformatique des Systèmes de Signalisation, Institut National de la Recherche Agronomique, UMR85, Unité Physiologie de la Reproduction et des Comportements; CNRS, UMR7247, Nouzilly, France; LE STUDIUM(®) Loire Valley Institute for Advanced Studies, Orléans, France.
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19
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Wang PC, Ho IK, Lee CWS. Buprenorphine-elicited alteration of adenylate cyclase activity in human embryonic kidney 293 cells coexpressing κ-, μ-opioid and nociceptin receptors. J Cell Mol Med 2015; 19:2587-96. [PMID: 26153065 PMCID: PMC4627564 DOI: 10.1111/jcmm.12644] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/28/2015] [Indexed: 02/03/2023] Open
Abstract
Buprenorphine, a maintenance drug for heroin addicts, exerts its pharmacological function via κ- (KOP), μ-opioid (MOP) and nociceptin/opioid receptor-like 1 (NOP) receptors. Previously, we investigated its effects in an in vitro model expressing human MOP and NOP receptors individually or simultaneously (MOP, NOP, and MOP+NOP) in human embryonic kidney 293 cells. Here, we expanded this cell model by expressing human KOP, MOP and NOP receptors individually or simultaneously (KOP, KOP+MOP, KOP+NOP and KOP+MOP+NOP). Radioligand binding with tritium-labelled diprenorphine confirmed the expression of KOP receptors. Immunoblotting and immunocytochemistry indicated that the expressed KOP, MOP and NOP receptors are N-linked glycoproteins and colocalized in cytoplasmic compartments. Acute application of the opioid receptor agonists— U-69593, DAMGO and nociceptin— inhibited adenylate cyclase (AC) activity in cells expressing KOP, MOP and NOP receptors respectively. Buprenorphine, when applied acutely, inhibited AC activity to ~90% in cells expressing KOP+MOP+NOP receptors. Chronic exposure to buprenorphine induced concentration-dependent AC superactivation in cells expressing KOP+NOP receptors, and the level of this superactivation was even higher in KOP+MOP+NOP-expressing cells. Our study demonstrated that MOP receptor could enhance AC regulation in the presence of coexpressed KOP and NOP receptors, and NOP receptor is essential for concentration-dependent AC superactivation elicited by chronic buprenorphine exposure.
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Affiliation(s)
- Pei-Chen Wang
- Neuropsychiatric Center, National Health Research Institutes, Miaoli County, Taiwan
| | - Ing-Kang Ho
- Neuropsychiatric Center, National Health Research Institutes, Miaoli County, Taiwan.,Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan.,Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan
| | - Cynthia Wei-Sheng Lee
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan.,China Medical University, Taichung, Taiwan
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20
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Fluorescence-based, high-throughput assays for μ-opioid receptor activation using a membrane potential-sensitive dye. Methods Mol Biol 2015; 1230:177-85. [PMID: 25293325 DOI: 10.1007/978-1-4939-1708-2_14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The development of new and improved opioid analgesics requires high-throughput screening (HTS) methods to identify potential therapeutics from large libraries of lead compounds. Here we describe two simple, real-time fluorescence-based assays of μ-opioid receptor activation that may be scaled up for HTS. In AtT-20 cells expressing the μ-opioid receptor (MOPr), opioids activate endogenous G protein gated inwardly rectifying K channels (GIRK channels), leading to membrane hyperpolarization. In Chinese hamster ovary cells expressing MOPr, adenylyl cyclase activation via forskolin results in membrane hyperpolarization, which is inhibited by opioids. Changes in membrane potential can be measured using a proprietary membrane potential-sensitive dye. In contrast to many HTS methods currently available, these assays reflect naturalistic coupling of the receptor to effector molecules.
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21
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Tran TA, Shin YJ, Kramer B, Choi J, Zou N, Vallar P, Martens P, Douglas Boatman P, Adams JW, Ramirez J, Shi Y, Morgan M, Unett DJ, Chang S, Shu HH, Tung SF, Semple G. Discovery of a new series of potent prostacyclin receptor agonists with in vivo activity in rat. Bioorg Med Chem Lett 2015; 25:1030-5. [DOI: 10.1016/j.bmcl.2015.01.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 12/19/2022]
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22
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De Haes W, Van Sinay E, Detienne G, Temmerman L, Schoofs L, Boonen K. Functional neuropeptidomics in invertebrates. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1854:812-26. [PMID: 25528324 DOI: 10.1016/j.bbapap.2014.12.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/27/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
Abstract
Neuropeptides are key messengers in almost all physiological processes. They originate from larger precursors and are extensively processed to become bioactive. Neuropeptidomics aims to comprehensively identify the collection of neuropeptides in an organism, organ, tissue or cell. The neuropeptidome of several invertebrates is thoroughly explored since they are important model organisms (and models for human diseases), disease vectors and pest species. The charting of the neuropeptidome is the first step towards understanding peptidergic signaling. This review will first discuss the latest developments in exploring the neuropeptidome. The physiological roles and modes of action of neuropeptides can be explored in two ways, which are largely orthogonal and therefore complementary. The first way consists of inferring the functions of neuropeptides by a forward approach where neuropeptide profiles are compared under different physiological conditions. Second is the reverse approach were neuropeptide collections are used to screen for receptor-binding. This is followed by localization studies and functional tests. This review will focus on how these different functional screening methods contributed to the field of invertebrate neuropeptidomics and expanded our knowledge of peptidergic signaling. This article is part of a Special Issue entitled: Neuroproteomics: Applications in Neuroscience and Neurology.
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Affiliation(s)
- Wouter De Haes
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Elien Van Sinay
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Giel Detienne
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Liesbet Temmerman
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Liliane Schoofs
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Kurt Boonen
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium.
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23
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Han S, Thoresen L, Zhu X, Narayanan S, Jung JK, Strah-Pleynet S, Decaire M, Choi K, Xiong Y, Yue D, Semple G, Thatte J, Solomon M, Fu L, Whelan K, Al-Shamma H, Gatlin J, Chen R, Dang H, Pride C, Gaidarov I, Unett DJ, Behan DP, Sadeque A, Usmani KA, Chen C, Edwards J, Morgan M, Jones RM. Discovery of 1a,2,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalen-4-carboxamides as potent and selective CB2 receptor agonists. Bioorg Med Chem Lett 2014; 25:322-6. [PMID: 25488844 DOI: 10.1016/j.bmcl.2014.11.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 10/24/2022]
Abstract
The design and synthesis of novel 1a,2,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalen-4-carboxamide CB2 selective ligands for the potential treatment of pain is described. Compound (R,R)-25 has good balance between CB2 agonist potency and selectivity over CB1, and possesses overall favorable pharmaceutical properties. It also demonstrated robust in vivo efficacy mediated via CB2 activation in the rodent models of inflammatory and osteoarthritis pain after oral administration.
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Affiliation(s)
- Sangdon Han
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA.
| | - Lars Thoresen
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Xiuwen Zhu
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Sanju Narayanan
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Jae-Kyu Jung
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | | | - Marc Decaire
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Karoline Choi
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Yifeng Xiong
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Dawei Yue
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Graeme Semple
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Jayant Thatte
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Michelle Solomon
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Lixia Fu
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Kevin Whelan
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Hussien Al-Shamma
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Joel Gatlin
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Ruoping Chen
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Huong Dang
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Cameron Pride
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Ibragim Gaidarov
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - David J Unett
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Dominic P Behan
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Abu Sadeque
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Khawja A Usmani
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Chuan Chen
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Jeffrey Edwards
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Michael Morgan
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Robert M Jones
- Arena Pharmaceuticals, 6154 Nancy Ridge Drive, San Diego, CA 92121, USA
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24
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Rossant CJ, Matthews C, Neal F, Colley C, Gardener MJ, Vaughan T. Versatility of Homogeneous Time-Resolved Fluorescence Resonance Energy Transfer Assays for Biologics Drug Discovery. ACTA ACUST UNITED AC 2014; 20:508-18. [DOI: 10.1177/1087057114557464] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Identification of potential lead antibodies in the drug discovery process requires the use of assays that not only measure binding of the antibody to the target molecule but assess a wide range of other characteristics. These include affinity ranking, measurement of their ability to inhibit relevant protein-protein interactions, assessment of their selectivity for the target protein, and determination of their species cross-reactivity profiles to support in vivo studies. Time-resolved fluorescence resonance energy transfer is a technology that offers the flexibility for development of such assays, through the availability of donor and acceptor fluorophore-conjugated reagents for detection of multiple tags or fusion proteins. The time-resolved component of the technology reduces potential assay interference, allowing screening of a range of different crude sample types derived from the bacterial or mammalian cell expression systems often used for antibody discovery projects. Here we describe the successful application of this technology across multiple projects targeting soluble proteins and demonstrate how it has provided key information for the isolation of potential therapeutic antibodies with the desired activity profile.
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Affiliation(s)
- Christine J. Rossant
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
- Crescendo Biologics, Cambridge, UK
| | - Carl Matthews
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
| | - Frances Neal
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
| | - Caroline Colley
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
| | | | - Tristan Vaughan
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
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25
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Trehan A, Rotgers E, Coffey ET, Huhtaniemi I, Rivero-Müller A. CANDLES, an assay for monitoring GPCR induced cAMP generation in cell cultures. Cell Commun Signal 2014; 12:70. [PMID: 25366423 PMCID: PMC4228090 DOI: 10.1186/s12964-014-0070-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/19/2014] [Indexed: 11/10/2022] Open
Abstract
Background G protein-coupled receptors (GPCRs) represent a physiologically and pharmacologically important family of receptors that upon coupling to GαS stimulate cAMP production catalyzed by adenylyl cyclase. Thus, developing assays to monitor cAMP production is crucial to screen for ligands in studies of GPCR signaling. Primary cell cultures represent a more robust model than cell lines to study GPCR signaling since they physiologically resemble the parent tissue. Current cAMP assays have two fundamental limitations: 1) absence of cAMP kinetics as competition-based assays require cell lysis and measure only a single time-point, and 2) high variation with separate samples needed to measure consecutive time points. The utility of real-time cAMP biosensors is also limited in primary cell cultures due to their poor transfection efficiency, variable expression levels and inability to select stable clones. We therefore, decided to develop an assay that can measure cAMP not only at a single time-point but the entire cAMP kinetics after GPCR activation in untransfected primary cells. Results CANDLES (Cyclic AMP iNdirect Detection by Light Emission from Sensor cells) assay for monitoring cAMP kinetics in cell cultures, particularly in primary cultures was developed. The assay requires co-culturing of primary cells with sensor cells that stably express a luminescent cAMP sensor. Upon GPCR activation in primary cells, cAMP is transferred to sensor cells via gap junction channels, thereby evoking a luminescent read-out. GPCR activation using primary cultures of rat cortical neurons and mouse granulosa cells was measured. Kinetic responses of different agonists to adrenergic receptors were also compared using rat cortical neurons. The assay optimization was done by varying sensor-test cell ratio, using phosphodiesterase inhibitors and testing cell-cell contact requirement. Conclusions Here we present CANDLES assay based on co-culturing test cells with cAMP-detecting sensor cells. This co-culture setup allows kinetic measurements, eliminates primary cell transfections and reduces variability. A variety of cell types (rat cortical neurons, mouse granulosa cells and established cell lines) and receptors (adrenergic, follicle stimulating hormone and luteinizing hormone/chorionic gonadotropin receptors) were tested for use with CANDLES. The assay is best applied while comparing cAMP generation curves upon different drug treatments to untransfected primary cells. Electronic supplementary material The online version of this article (doi:10.1186/s12964-014-0070-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ashutosh Trehan
- Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland.
| | - Emmi Rotgers
- Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland.
| | - Eleanor T Coffey
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, BioCity, Turku, Finland.
| | - Ilpo Huhtaniemi
- Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland. .,Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Hammersmith Campus, Imperial College London, London, UK.
| | - Adolfo Rivero-Müller
- Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland. .,Faculty of Natural Sciences and Technology, Åbo Akademi University, Turku, Finland. .,Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland.
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Nørskov-Lauritsen L, Thomsen ARB, Bräuner-Osborne H. G protein-coupled receptor signaling analysis using homogenous time-resolved Förster resonance energy transfer (HTRF®) technology. Int J Mol Sci 2014; 15:2554-72. [PMID: 24531140 PMCID: PMC3958867 DOI: 10.3390/ijms15022554] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/17/2014] [Accepted: 01/28/2014] [Indexed: 11/18/2022] Open
Abstract
Studying multidimensional signaling of G protein-coupled receptors (GPCRs) in search of new and better treatments requires flexible, reliable and sensitive assays in high throughput screening (HTS) formats. Today, more than half of the detection techniques used in HTS are based on fluorescence, because of the high sensitivity and rich signal, but quenching, optical interferences and light scattering are serious drawbacks. In the 1990s the HTRF® (Cisbio Bioassays, Codolet, France) technology based on Förster resonance energy transfer (FRET) in a time-resolved homogeneous format was developed. This improved technology diminished the traditional drawbacks. The optimized protocol described here based on HTRF® technology was used to study the activation and signaling pathways of the calcium-sensing receptor, CaSR, a GPCR responsible for maintaining calcium homeostasis. Stimulation of the CaSR by agonists activated several pathways, which were detected by measuring accumulation of the second messengers D-myo-inositol 1-phosphate (IP1) and cyclic adenosine 3',5'-monophosphate (cAMP), and by measuring the phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2). Here we show how an optimized HTRF® platform with numerous advantages compared to previous assays provides a substantial and robust mode of investigating GPCR signaling. It is furthermore discussed how these assays can be optimized and miniaturized to meet HTS requirements and for screening compound libraries.
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Affiliation(s)
- Lenea Nørskov-Lauritsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Fruebjergvej 3, Mailbox 10, Copenhagen DK-2100, Denmark.
| | - Alex Rojas Bie Thomsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Fruebjergvej 3, Mailbox 10, Copenhagen DK-2100, Denmark.
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Fruebjergvej 3, Mailbox 10, Copenhagen DK-2100, Denmark.
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Wang WG, Wu ZY, Chen R, Li HZ, Li HM, Li YD, Li RT, Luo HR. Pierisformotoxins A-D, polyesterified grayanane diterpenoids from Pieris formosa and their cAMP-decreasing activities. Chem Biodivers 2014; 10:1061-71. [PMID: 23776021 DOI: 10.1002/cbdv.201200046] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Indexed: 11/11/2022]
Abstract
Four highly acylated diterpenoids, designated as pierisformotoxins A-D (1-4, resp.), along with 26 known compounds, were isolated from the flowers of Pieris formosa. Among them, pierisformotoxins A and B (1 and 2, resp.) were new highly acylated grayanane diterpenoids, of which the five-membered ring A has undergone an oxidative cleavage between C(3) and C(4), followed by lactonization, to give rise to a five-membered lactone ring between C(3) and C(5), differing from the previously reported grayanane diterpenoids with a 5/7/6/5 ring system. Results of the cAMP-regulation-activity assay showed that pierisformotoxin C (3) at 10 μM (inhibitory ratio (IR): 10.1%) or 2 μM (9.8%), and pierisformotoxin B (2) at 50 μM (13.9%) significantly decreased the cAMP level in N1E-115 neuroblastoma cells (p<0.05).
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Affiliation(s)
- Wei-Guang Wang
- The Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650050, PR China
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Knapman A, Abogadie F, McIntrye P, Connor M. A real-time, fluorescence-based assay for measuring μ-opioid receptor modulation of adenylyl cyclase activity in Chinese hamster ovary cells. ACTA ACUST UNITED AC 2013; 19:223-31. [PMID: 23989451 DOI: 10.1177/1087057113501391] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Inhibition of adenylyl cyclase (AC) activity is frequently used to measure µ-opioid receptor (MOR) activation. We sought to develop a simple, rapid assay of AC activity in whole cells that could be used to study MOR signaling. Chinese hamster ovary cells expressing human MOR (CHO-MOR cells) were grown in 96-well plates and loaded with membrane potential-sensitive fluorescent dye. CHO-MOR cells were treated with the AC activator forskolin (FSK), with or without simultaneous application of MOR agonists, and the resulting change in fluorescence was measured. CHO-MOR cells hyperpolarized in response to application of FSK (pEC₅₀, 7.3) or calcitonin (pEC₅₀, 9.4). A submaximally effective concentration of FSK (300 nM) caused a 52% ± 2% decrease in fluorescence. Simultaneous application of the opioids DAMGO (pEC₅₀, 7.4; E(max), 56%), morphine (pEC₅₀, 7.0; E(max), 61%); and buprenorphine (pEC₅₀, 8.6; E(max), 24%) inhibited the FSK response in a dose-dependent manner while having no effect by themselves. The effects of DAMGO were blocked by pertussis toxin. This assay represents a simple, robust method for real-time observation of AC inhibition by MOR in CHO cells. It represents an appealing alternative to end-point assays that rely on cAMP accumulation and can avoid potential confounds associated with rapid desensitization of MOR signaling.
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Affiliation(s)
- Alisa Knapman
- 1Australian School of Advanced Medicine, Macquarie University, NSW Australia
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Kumar P, Song ZH. Identification of raloxifene as a novel CB2 inverse agonist. Biochem Biophys Res Commun 2013; 435:76-81. [PMID: 23611779 DOI: 10.1016/j.bbrc.2013.04.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 04/04/2013] [Indexed: 11/16/2022]
Abstract
The purpose of the current study was to apply a high throughput assay to systematically screen a library of food and drug administration (FDA)-approved drugs as potential ligands for the cannabinoid receptor 2 (CB2). A cell-based, homogenous time resolved fluorescence (HTRF) method for measuring changes in intracellular cAMP levels was validated and found to be suitable for testing ligands that may act on CB2. Among the 640 FDA-approved drugs screened, raloxifene, a drug used to treat/prevent post-menopausal osteoporosis, was identified for the first time to be a novel CB2 inverse agonist. Our results demonstrated that by acting on CB2, raloxifene enhances forskolin-stimulated cAMP accumulation in a concentration-dependant manner. Furthermore, our data showed that raloxifene competes concentration-dependently for specific [(3)H]CP-55,940 binding to CB2. In addition, raloxifene pretreatment caused a rightward shift of the concentration-response curves of the cannabinoid agonists CP-55,940, HU-210, and WIN55,212-2. Raloxifene antagonism is most likely competitive in nature, as these rightward shifts were parallel and were not associated with any changes in the efficacy of cannabinoid agonists on CB2. Our discovery that raloxfiene is an inverse agonist for CB2 suggests that it might be possible to repurpose this FDA-approved drug for novel therapeutic indications for which CB2 is a target. Furthermore, identifying raloxifene as a CB2 inverse agonist also provides important novel mechanisms of actions to explain the known therapeutic effects of raloxifene.
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Affiliation(s)
- Pritesh Kumar
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40292, USA
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Kopra K, Kainulainen M, Mikkonen P, Rozwandowicz-Jansen A, Hänninen P, Härmä H. Multiparametric homogeneous method for identification of ligand binding to G protein-coupled receptors: receptor-ligand binding and β-arrestin assay. Anal Chem 2013; 85:2276-81. [PMID: 23330639 DOI: 10.1021/ac303215r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two homogeneous assay systems have been combined to provide a new cell-based functional assay. The assay can be used to identify ligand binding to β(2)-adrenergic receptors, but also the downstream response can be determined in the same assay. Both the quenching resonance energy transfer (QRET) and the DiscoveRx PathHunter assay formats allow the use of intact cells. The homogeneous QRET technique is a single-label approach based on nonspecific quenching of the time-resolved luminescence, enabling agonist and antagonist receptor binding measurements. The commercial PathHunter assay is in turn based on enzyme fragment complementation, which can be detected on the basis of chemiluminescence signal. In the PathHunter technology the enzyme complementation is recorded immediately downstream of agonist-induced receptor activation. The new multiparametric detection technology combines these two assay methods enabling the identification of agonist, and antagonist binding to the receptor, and the agonist-induced response. Using the QRET and the PathHunter methods a panel of β(2)-adrenergic receptor ligands (epinephrine, terbutaline, metaproterenol, salmeterol, propranolol, alprenolol, bisoprolol, ICI 118,551, and bucindolol) was tested to prove the assay performance. The signal-to-background ratio for tested ligands ranged from 5 to 11 and from 6 to 18 with QRET and PathHunter, respectively. Combined homogeneous assay technique can provide an informative method for screening purposes and an efficient way to monitor receptor-ligand interaction, thus separating agonist from antagonist.
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Affiliation(s)
- Kari Kopra
- Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland.
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Zherdeva VV, Savitsky AP. Using lanthanide-based resonance energy transfer for in vitro and in vivo studies of biological processes. BIOCHEMISTRY (MOSCOW) 2013; 77:1553-74. [DOI: 10.1134/s0006297912130111] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Mathiesen JM, Vedel L, Bräuner-Osborne H. cAMP biosensors applied in molecular pharmacological studies of G protein-coupled receptors. Methods Enzymol 2013; 522:191-207. [PMID: 23374187 DOI: 10.1016/b978-0-12-407865-9.00011-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Cyclic adenosine monophosphate (cAMP) is a common second messenger that mediates numerous biological responses. Intracellular cAMP levels are increased by activation of G(s)-coupled G protein-coupled receptors (GPCRs) and decreased by activation of G(i)-coupled GPCRs via the adenylyl cyclase. Many end-point assays for quantifying GPCR-mediated changes in intracellular cAMP levels exist. More recently, fluorescence resonance energy transfer (FRET)-based cAMP biosensors that can quantify intracellular cAMP levels in real time have been developed. These FRET-based cAMP biosensors have been used primarily in single cell FRET microscopy to monitor and visualize changes in cAMP upon GPCR activation. Here, a similar cAMP biosensor with a more efficient mCerulean/mCitrine FRET pair is described for use in the 384-well plate format. After cloning and expression in HEK293 cells, the biosensor is characterized in the 384-well plate format and used for measuring the signaling of the G(s)-coupled β(2)-adrenergic receptor. The procedures described may be applied for other FRET-based biosensors in terms of characterization and conversion to the 384-well plate format.
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Affiliation(s)
- Jesper Mosolff Mathiesen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Time-Resolved Förster Resonance Energy Transfer-Based Technologies to Investigate G Protein-Coupled Receptor Machinery. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 113:275-312. [DOI: 10.1016/b978-0-12-386932-6.00007-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Chen CZ, Southall N, Xiao J, Marugan JJ, Ferrer M, Hu X, Jones RE, Feng S, Agoulnik IU, Zheng W, Agoulnik AI. Identification of small-molecule agonists of human relaxin family receptor 1 (RXFP1) by using a homogenous cell-based cAMP assay. ACTA ACUST UNITED AC 2012; 18:670-7. [PMID: 23212924 DOI: 10.1177/1087057112469406] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The relaxin hormone is involved in a variety of biological functions, including female reproduction and parturition, as well as regulation of cardiovascular, renal, pulmonary, and hepatic functions. It regulates extracellular matrix remodeling, cell invasiveness, proliferation, differentiation, and overall tissue homeostasis. The G protein-coupled receptor (GPCR) relaxin family receptor 1 (RXFP1) is a cognate relaxin receptor that mainly signals through cyclic AMP second messenger. Although agonists of the receptor could have a wide range of pharmacologic utility, until now there have been no reported small-molecule agonists for relaxin receptors. Here, we report the development of a quantitative high-throughput platform for an RXFP1 agonist screen based on homogenous cell-based HTRF cyclic AMP (cAMP) assay technology. Two small molecules of similar structure were independently identified from a screen of more than 365 677 compounds. Neither compound showed activity in a counterscreen with HEK293T cells transfected with an unrelated GPCR vasopressin 1b receptor. These small-molecule agonists also demonstrated selectivity against the RXFP2 receptor, providing a basis for future medicinal chemistry optimization of selective relaxin receptor agonists.
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Affiliation(s)
- Catherine Z Chen
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
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35
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Zhang Z, Guan N, Li T, Mais DE, Wang M. Quality control of cell-based high-throughput drug screening. Acta Pharm Sin B 2012. [DOI: 10.1016/j.apsb.2012.03.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Abstract
G-protein-coupled receptors (GPCRs) mediate many important physiological functions and
are considered as one of the most successful therapeutic targets for a broad spectrum of
diseases. The design and implementation of high-throughput GPCR assays that allow the
cost-effective screening of large compound libraries to identify novel drug candidates are
critical in early drug discovery. Early functional GPCR assays depend primarily on the
measurement of G-protein-mediated 2nd messenger generation. Taking advantage of the
continuously deepening understanding of GPCR signal transduction, many
G-protein-independent pathways are utilized to detect the activity of GPCRs, and may
provide additional information on functional selectivity of candidate compounds. With the
combination of automated imaging systems and label-free detection systems, such assays are
now suitable for high-throughput screening (HTS). In this review, we summarize the most
widely used GPCR assays and recent advances in HTS technologies for GPCR drug
discovery.
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Millan MJ, Mannoury la Cour C, Chanrion B, Dupuis DS, Di Cara B, Audinot V, Cussac D, Newman-Tancredi A, Kamal M, Boutin JA, Jockers R, Marin P, Bockaert J, Muller O, Dekeyne A, Lavielle G. S32212, a novel serotonin type 2C receptor inverse agonist/α2-adrenoceptor antagonist and potential antidepressant: I. A mechanistic characterization. J Pharmacol Exp Ther 2011; 340:750-64. [PMID: 22178752 DOI: 10.1124/jpet.111.187468] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Although most antidepressants suppress serotonin (5-HT) and/or noradrenaline reuptake, blockade of 5-HT(2C) receptors and α(2)-adrenoceptors likewise enhances monoaminergic transmission. These sites are targeted by the urea derivative N- [4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]-1,2-dihydro-3-H-benzo[e]indole-3-carboxamide (S32212). S32212 was devoid of affinity for monoamine reuptake sites, yet displayed pronounced affinity (pK(i), 8.2) for constitutively active human 5-HT(2CINI) (h5-HT(2CINI)) receptors, behaving as an inverse agonist in reducing basal Gα(q) activation, [(3)H]inositol-phosphate production, and the spontaneous association of h5-HT(2CINI)-Renilla luciferase receptors with β-arrestin2-yellow fluorescent protein. Furthermore, upon 18-h pretreatment, S32212 enhanced the plasma membrane expression of h5-HT(2CINI) receptors as visualized by confocal microscopy and quantified by enzyme-linked immunosorbent assay. Its actions were prevented by the neutral antagonist 6-chloro-5-methyl-N-[6-(2-methylpyridin-3-yloxy)pyridin-3-yl]indoline-1-carboxamide (SB242,084), which also impeded the induction by long-term exposure to S32212 of otherwise absent Ca(2+) mobilization in mouse cortical neurones. In vivo, S32212 blunted the inhibitory influence of the 5-HT(2C) agonist 2-(3-chlorobenzyloxy)-6-(1-piperazinyl)pyrazine (CP809,101) on ventrotegmental dopaminergic neurones. S32212 also blocked 5-HT-induced Gα(q) and phospholipase C activation at the h5-HT(2A) and, less potently, h5-HT(2B) receptors and suppressed the discriminative stimulus properties of the 5-HT(2A) agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane in rats. S32212 manifested marked affinity for human α(2A)- (pK(i) 7.2), α(2B)- (pK(i) 8.2), and α(2C)- (pK(i) 7.4) adrenoceptors, at which it abolished noradrenaline-induced recruitment of Gα(i3), Gα(o), adenylyl cyclase, and extracellular-regulated kinase1/2. Moreover, S32212 dose-dependently abolished the discriminative stimulus effects of the α(2)-adrenoceptor agonist (S)-spiro[(1-oxa-2-amino-3-azacyclopent-2-ene)-4,2'-(1',2',3',4'-tetrahydronaphthalene)] (S18616). Finally, S32212 displayed negligible affinity for α(1A)-adrenoceptors, histamine H(1) receptors, and muscarinic M(1) receptors. In conclusion, S32212 behaves as an inverse agonist at h5-HT(2C) receptors and as an antagonist at human α(2)-adrenoceptors (and h5-HT(2A) receptors). Its promising profile in preclinical models potentially relevant to the treatment of depression is described in J Pharmacol Exp Ther 340:765-780, 2012.
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Affiliation(s)
- Mark J Millan
- Institut de Recherches Servier, Centre de Recherches de Croissy, Psychopharmacology Department, 125 Chemin de Ronde, 78290 Croissy/Seine, France.
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Lee CWS, Yan JY, Chiang YC, Hung TW, Wang HL, Chiou LC, Ho IK. Differential pharmacological actions of methadone and buprenorphine in human embryonic kidney 293 cells coexpressing human μ-opioid and opioid receptor-like 1 receptors. Neurochem Res 2011; 36:2008-21. [PMID: 21671107 PMCID: PMC3183316 DOI: 10.1007/s11064-011-0525-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2011] [Indexed: 11/26/2022]
Abstract
Methadone and buprenorphine are used in maintenance therapy for heroin addicts. In this study, we compared their effects on adenylate cyclase (AC) activity in human embryonic kidney (HEK) 293 cells stably overexpressing human μ-opioid receptor (MOR) and nociceptin/opioid receptor-like 1 receptor (ORL1) simultaneously. After acute exposure, methadone inhibited AC activity; however, buprenorphine induced compromised AC inhibition. When naloxone was introduced after 30 min incubation with methadone, the AC activity was enhanced. This was not observed in the case of buprenorphine. Enhancement of the AC activity was more significant when the incubation lasted for 4 h, and prolonged exposure to buprenorphine elevated the AC activity as well. The removal of methadone and buprenorphine by washing also obtained similar AC superactivation as that revealed by naloxone challenge. The study demonstrated that methadone and buprenorphine exert initially different yet eventually convergent adaptive changes of AC activity in cells coexpressing human MOR and ORL1 receptors.
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Affiliation(s)
- Cynthia Wei-Sheng Lee
- Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, 35053 Taiwan
| | - Jia-Ying Yan
- Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, 35053 Taiwan
| | - Yao-Chang Chiang
- Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, 35053 Taiwan
| | - Tsai-Wei Hung
- Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, 35053 Taiwan
| | - Hung-Li Wang
- Department of Physiology, Chang Gung University School of Medicine, Kwei-San, Taoyuan, 33302 Taiwan
| | - Lih-Chu Chiou
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051 Taiwan
| | - Ing-Kang Ho
- Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, 35053 Taiwan
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Wu ZY, Li HZ, Wang WG, Li HM, Chen R, Li RT, Luo HR. Lyonin A, a new 9,10-Secograyanotoxin from Lyonia ovalifolia. Chem Biodivers 2011; 8:1182-7. [PMID: 21674790 DOI: 10.1002/cbdv.201000188] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phytochemical studies on the branches and leaves of Lyonia ovalifolia yielded a new grayanane diterpenoid, lyonin A (1), together with two known compounds, secorhodomollolides A and D (2 and 3, resp.). The structure of 1 was elucidated by combination of 1D- and 2D-NMR, and MS analyses. Compound 1 turned out to be a new, highly O-acylated grayanane diterpenoid, of which ring B has undergone an oxidative cleavage between C(9) and C(10), yielding a system differing from the previously reported grayanane type with a 5/7/6/5 ring system. Results of the cAMP regulation activity assay showed that compounds 2 and 3 at 50 μM induced a significantly decreased cAMP level in N1E-115 neuroblastoma cells (p<0.001), indicating neuropharmacological potential.
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Affiliation(s)
- Zhao-Yuan Wu
- The College of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650224, P. R. China
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Hill SJ, Williams C, May LT. Insights into GPCR pharmacology from the measurement of changes in intracellular cyclic AMP; advantages and pitfalls of differing methodologies. Br J Pharmacol 2011; 161:1266-75. [PMID: 21049583 DOI: 10.1111/j.1476-5381.2010.00779.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
It is clear that the G protein-coupled receptor family play a key role in the pharmaceutical industry, with a significant proportion of approved drugs targeting this protein class. While our growing understanding of the complexity of G protein-coupled receptor pharmacology is playing a key role in the future success of these endeavours, with allosteric mechanisms now well integrated into the industrial community and G protein-independent signalling mechanisms establishing themselves as novel phenomenon to be exploited, it is still possible to underestimate the complexity of G protein signal transduction mechanisms and the impact that inappropriate study of these mechanisms can have on data interpretation. In this manuscript we review different approaches to measuring the cAMP signal transduction pathway, with particular emphasis on key parameters influencing the data quality and biological relevance.
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Affiliation(s)
- Stephen J Hill
- Institute of Cell Signalling, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham, UK.
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5-HT6 receptor signal transduction second messenger systems. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 94:89-110. [PMID: 21081203 DOI: 10.1016/b978-0-12-384976-2.00004-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Trinquet E, Bouhelal R, Dietz M. Monitoring Gq-coupled receptor response through inositol phosphate quantification with the IP-One assay. Expert Opin Drug Discov 2011; 6:981-94. [DOI: 10.1517/17460441.2011.608658] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Taouji S, Dahan S, Bossé R, Chevet E. Current Screens Based on the AlphaScreen Technology for Deciphering Cell Signalling Pathways. Curr Genomics 2011; 10:93-101. [PMID: 19794881 PMCID: PMC2699825 DOI: 10.2174/138920209787847041] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 01/08/2009] [Accepted: 01/20/2009] [Indexed: 11/22/2022] Open
Abstract
Global deciphering of signal transduction pathways represents a new challenge of the post-genomic era. However, for the majority of these signaling pathways the role(s), the function(s) and the interaction(s) of the signaling intermediates remain to be characterized in an integrated fashion. The global molecular study of cell signaling pathways and networks consequently requires sensitive, robust technologies which may allow in addition multi-parallel and highthroughput applications. The Alphascreen™ technology, relying on a bead-based homogenous approach, constitutes a valuable tool to detect and quantify a wide range of signaling events such as enzymatic activities or biomolecular interactions. In this article, we exhaustively review the literature and report the broad spectrum of Alphascreen™-based applications in the study of signal transduction pathways.
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Wang K, Yang R, Xu J, Zhang Y, Zhu L, Lin J, Huang B. DEVELOPMENT OF AN ALPHASCREEN-BASED HIGH-THROUGHPUT SCREENING ASSAY FOR INHIBITORS OF HUMAN VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR-3. J Immunoassay Immunochem 2011; 32:219-32. [DOI: 10.1080/15321819.2011.559296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Niebel B, Weiche B, Mueller AL, Li DY, Karnowski N, Famulok M. A luminescent oxygen channeling biosensor that measures small GTPase activation. Chem Commun (Camb) 2011; 47:7521-3. [PMID: 21625685 DOI: 10.1039/c1cc11944c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We established a homogeneous luminescent oxygen channeling sensor for measuring activation states of small GTPases. The assay quantifies activated GTPases in cell lysates, can be applied to different GTPases, and can be used for multiplex screening. The study will provide guidelines for determining activation states of diverse GTPases in various biological contexts.
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Affiliation(s)
- Björn Niebel
- LIMES Institute, Chemical Biology & Medicinal Chemistry Unit, University of Bonn, 53121 Bonn, Germany
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Wang Y, Kong Y, Shei GJ, Kang L, Cvijic ME. Development of a cyclic adenosine monophosphate assay for Gi-coupled G protein-coupled receptors by utilizing the endogenous calcitonin activity in Chinese hamster ovary cells. Assay Drug Dev Technol 2011; 9:522-31. [PMID: 21561374 DOI: 10.1089/adt.2010.0361] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Activation of G(i)-coupled G protein-coupled receptor (GPCRs) by their ligands leads to inhibition of adenylyl cyclase (AC) and reduction of cyclic adenosine monophosphate (cAMP) levels in cells. The traditional cAMP assay for G(i)-coupled GPCRs commonly uses forskolin, a nonspecific AC activator, to increase the basal cAMP level in cells to create an assay window for ligand detection. However, there is still a need to develop a nonforskolin-based cAMP assay because of the challenges inherent in titrating the concentration of forskolin to achieve a reliable assay window, along with issues related to the cAMP-independent effects of forskolin. Herein, we describe such an assay by utilizing the endogenous activity of the calcitonin receptor in Chinese hamster ovary (CHO) cells. The calcitonin receptor is a G(s)-coupled GPCR that, when activated by calcitonin, leads to the stimulation of AC and increases cAMP in cells. Thus, we use calcitonin, instead of forskolin, to increase the basal cAMP level in CHO cells to achieve an assay window. We demonstrated that calcitonin peptides robustly increased cAMP accumulation in several CHO cell lines stably expressing well-known G(i)-coupled GPCRs, such as the Dopamine D2 receptor, the Opioid μ receptor, or the Cannabinoid receptor-1. Agonists of these G(i)-coupled GPCRs attenuated calcitonin-induced cAMP production in their receptor stable cell lines. On the other hand, antagonists and/or inverse agonists blocked the effects of their agonists on calcitonin-induced cAMP production. This calcitonin-based cAMP assay has been demonstrated to be sensitive and robust and exhibited acceptable assay windows (signal/noise ratio) and, thus, can be applied to screen for agonists and antagonists/inverse agonists of G(i)-coupled GPCRs in high-throughput screening formats.
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Affiliation(s)
- Yuren Wang
- Metabolic Disease Research, Bristol-Myers Squibb Company, 311 Pennington-Rocky Hill Road, Pennington, NJ 08534, USA.
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Martikkala E, Rozwandowicz-Jansen A, Hänninen P, Petäjä-Repo U, Härmä H. A homogeneous single-label time-resolved fluorescence cAMP assay. ACTA ACUST UNITED AC 2011; 16:356-62. [PMID: 21343601 DOI: 10.1177/1087057110397356] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
G-protein-coupled receptors (GPCRs) are an important class of pharmaceutical drug targets. Functional high-throughput GPCR assays are needed to test an increasing number of synthesized novel drug compounds and their function in signal transduction processes. Measurement of changes in the cyclic adenosine monophosphate (cAMP) concentration is a widely used method to verify GPCR activation in the adenylyl cyclase pathway. Here, a single-label time-resolved fluorescence and high-throughput screening (HTS)-feasible method was developed to measure changes in cAMP levels in HEK293(i) cells overexpressing either β(2)-adrenergic or δ-opioid receptors. In the quenching resonance energy transfer (QRET) technique, soluble quenchers reduce the signal of unbound europium(III)-labeled cAMP in solution, whereas the antibody-bound fraction is fluorescent. The feasibility of this homogeneous competitive assay was proven by agonist-mediated stimulation of receptors coupled to either the stimulatory G(s) or inhibitory G(i) proteins. The reproducibility of the assays was excellent, and Z' values exceeded 0.7. The dynamic range, signal-to-background ratio, and detection limit were compared with a commercial time-resolved fluorescence resonance energy transfer (TR-FRET) assay. In both homogeneous assays, similar assay parameters were obtained when adenylyl cyclase was stimulated directly by forskolin or via agonist-mediated activation of the G(s)-coupled β(2)AR. The advantage of using the single-label approach relates to the cost-effectiveness of the QRET system compared with the two-label TR-FRET assay as there is no need for labeling of two binding partners leading to reduced requirements for assay optimization.
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Affiliation(s)
- Eija Martikkala
- Laboratory of Biophysics and Medicity, University of Turku, Turku, Finland.
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E-6801, a 5-HT6 receptor agonist, improves recognition memory by combined modulation of cholinergic and glutamatergic neurotransmission in the rat. Psychopharmacology (Berl) 2011; 213:413-30. [PMID: 20405281 DOI: 10.1007/s00213-010-1854-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 03/24/2010] [Indexed: 12/21/2022]
Abstract
RATIONALE AND OBJECTIVES In rats, 5-hydroxytryptamine(6) (5-HT(6)) receptor antagonists improve learning and memory, but the effects of agonists are poorly defined. This study investigated the effects of 5-HT(6) receptor agonists and antagonists on a rodent model of recognition memory. METHODS Selective 5-HT(6) receptor agonists and antagonists were administered either alone, after a scopolamine-induced impairment, or combined with sub-effective doses of the acetylcholinesterase inhibitor, donepezil, or the glutamate NMDA receptor antagonist, memantine, in a novel object discrimination paradigm in adult rats. RESULTS After a 4-h inter-trial delay to induce natural forgetting, vehicle-treated rats spent an equivalent time exploring novel and familiar objects during the choice trial. The 5-HT(6) receptor agonists, E-6801 (1.25-10 mg/kg i.p.) and EMD-386088 (5-10 mg/kg i.p.), and antagonists, SB-271046 and Ro 04-6790 (5 and 10 mg/kg), along with donepezil (0.1-3 mg/kg) and memantine (5-20 mg/kg) all produced significant and mostly dose-dependent increases in novel object exploration, indicative of memory enhancement. Furthermore, sub-effective doses of E-6801 (1 mg/kg) when co-administered with either SB-271046 (3 mg/kg), donepezil (0.1 mg/kg) or memantine (5 mg/kg), and EMD-386088 (2 mg/kg) co-administered with SB-271046 (3 mg/kg) also significantly enhanced object-recognition memory. Additionally, using a 1-min inter-trial delay, E-6801 (2.5 and 5 mg/kg) was as effective as donepezil (0.3 and 1 mg/kg) in reversing a scopolamine-induced (0.5 mg/kg) impairment in object recognition. CONCLUSIONS This is the first study to demonstrate that E-6801, a potent 5-HT(6) receptor agonist, improves recognition memory by combined modulation of cholinergic and glutamatergic neurotransmission.
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Gesellchen F, Stangherlin A, Surdo N, Terrin A, Zoccarato A, Zaccolo M. Measuring spatiotemporal dynamics of cyclic AMP signaling in real-time using FRET-based biosensors. Methods Mol Biol 2011; 746:297-316. [PMID: 21607864 DOI: 10.1007/978-1-61779-126-0_16] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cyclic AMP governs many fundamental signaling events in eukaryotic cells. Although cAMP signaling has been a major research focus for a long time, recent technological developments are revealing novel aspects of this paradigmatic pathway. In this chapter, we give an overview over current fluorescence resonance energy transfer (FRET)-based sensors for detection of cAMP dynamics, and their application in monitoring local, compartmentalized cAMP signals within living cells. A basic step-by-step protocol is given for conducting a FRET experiment in primary cells with a unimolecular cAMP sensor, which can easily be adapted to a user's specific requirements.
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Affiliation(s)
- Frank Gesellchen
- Neuroscience and Molecular Pharmacology, Biomedical & Life Sciences, University of Glasgow, Glasgow, UK
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