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Tanaka C, Harada N, Teraoka Y, Urushizaki H, Shinmori Y, Onishi T, Yotsumoto Y, Ito Y, Kitakaze T, Inui T, Murata Y, Inui H, Yamaji R. Mogrol stimulates G-protein-coupled bile acid receptor 1 (GPBAR1/TGR5) and insulin secretion from pancreatic β-cells and alleviates hyperglycemia in mice. Sci Rep 2024; 14:3244. [PMID: 38332164 PMCID: PMC10853268 DOI: 10.1038/s41598-024-53380-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 01/31/2024] [Indexed: 02/10/2024] Open
Abstract
Target identification is a crucial step in elucidating the mechanisms by which functional food components exert their functions. Here, we identified the G-protein-coupled bile acid receptor 1 (GPBAR1, also known as TGR5) as a target of the triterpenoid mogrol, a class of aglycone mogroside derivative from Siraitia grosvenorii. Mogrol, but not mogrosides, activated cAMP-response element-mediated transcription in a TGR5-dependent manner. Additionally, mogrol selectively activated TGR5 but not the other bile acid-responsive receptors (i.e., farnesoid X receptor, vitamin D receptor, or muscarinic acetylcholine receptor M3). Several amino acids in TGR5 (L71A2.60, W75AECL1, Q77AECL1, R80AECL1, Y89A3.29, F161AECL2, L166A5.39, Y240A6.51, S247A6.58, Y251A6.62, L262A7.35, and L266A7.39) were found to be important for mogrol-induced activation. Mogrol activated insulin secretion under low-glucose conditions in INS-1 pancreatic β-cells, which can be inhibited by a TGR5 inhibitor. Similar effects of mogrol on insulin secretion were observed in the isolated mouse islets. Mogrol administration partially but significantly alleviated hyperglycemia in KKAy diabetic mice by increasing the insulin levels without affecting the β-cell mass or pancreatic insulin content. These results suggest that mogrol stimulates insulin secretion and alleviates hyperglycemia by acting as a TGR5 agonist.
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Affiliation(s)
- Chisato Tanaka
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Naoki Harada
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan.
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
| | - Yoshiaki Teraoka
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Hiroki Urushizaki
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Yoh Shinmori
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Teruaki Onishi
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Yusuke Yotsumoto
- Natural Materials Laboratory, Saraya Company, Ltd., 24-12 Tamatecho, Kashiwara, 582-0028, Kashiwara, Osaka, Japan
| | - Yuta Ito
- Natural Materials Laboratory, Saraya Company, Ltd., 24-12 Tamatecho, Kashiwara, 582-0028, Kashiwara, Osaka, Japan
| | - Tomoya Kitakaze
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Takashi Inui
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Yuji Murata
- Natural Materials Laboratory, Saraya Company, Ltd., 24-12 Tamatecho, Kashiwara, 582-0028, Kashiwara, Osaka, Japan
| | - Hiroshi Inui
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, 599-8531, Japan
- Department of Health and Nutrition, Otemae University, Osaka, Osaka, Japan
| | - Ryoichi Yamaji
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, 599-8531, Japan
- Center for Research and Development of Bioresources, Osaka Metropolitan University, Sakai, Osaka, Japan
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Van Daele M, Kilpatrick LE, Woolard J, Hill SJ. Characterisation of tyrosine kinase inhibitor-receptor interactions at VEGFR2 using sunitinib-red and nanoBRET. Biochem Pharmacol 2023:115672. [PMID: 37406966 DOI: 10.1016/j.bcp.2023.115672] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/13/2023] [Accepted: 06/26/2023] [Indexed: 07/07/2023]
Abstract
Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis, proliferation and migration of vascular endothelial cells. It is well known that cardiovascular safety liability for a wide range of small molecule tyrosine kinase inhibitors (TKIs) can result from interference with the VEGFR2 signalling system. In this study we have developed a ligand-binding assay using a fluorescent analogue of sunitinib (sunitinib-red) and full length VEGFR2 tagged on its C-terminus with the bioluminescent protein nanoluciferase to monitor ligand-binding to VEGFR2 using bioluminescence resonance energy transfer (BRET). This NanoBRET assay is a proximity-based assay (requiring the fluorescent and bioluminescent components to be within 10nm of each other) that can monitor the binding of ligands to the kinase domain of VEGFR2. Sunitinib-red was not membrane permeable but was able to monitor the binding affinity and kinetics of a range of TKIs in cell lysates. Kinetic studies showed that sunitinib-red bound rapidly to VEGFR2 at 25 °C and that cediranib had slower binding kinetics with an average residence time of 112 min. Comparison between the log Ki values for inhibition of binding of sunitinib-red and log IC50 values for attenuation of VEGF165a-stimulated NFAT responses showed very similar values for compounds that inhibited sunitinib-red binding. However, two compounds that failed to inhibit sunitinib-red binding (dasatinib and entospletinib) were still able to attenuate VEGFR2-mediated NFAT signalling through inhibition of downstream signalling events. These results suggest that these compounds may still exhibit cardiovascular liabilities as a result of interference with downstream VEGFR2 signalling.
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Affiliation(s)
- Marieke Van Daele
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK; Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK.
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Insights into the Function and Evolution of Taste 1 Receptor Gene Family in the Carnivore Fish Gilthead Seabream ( Sparus aurata). Int J Mol Sci 2020; 21:ijms21207732. [PMID: 33086689 PMCID: PMC7594079 DOI: 10.3390/ijms21207732] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 11/24/2022] Open
Abstract
A plethora of molecular and functional studies in tetrapods has led to the discovery of multiple taste 1 receptor (T1R) genes encoding G-protein coupled receptors (GPCRs) responsible for sweet (T1R2 + T1R3) and umami (T1R1 + T1R3) taste. In fish, the T1R gene family repertoires greatly expanded because of several T1R2 gene duplications, and recent studies have shown T1R2 functional divergence from canonical mammalian sweet taste perceptions, putatively as an adaptive mechanism to develop distinct feeding strategies in highly diverse aquatic habitats. We addressed this question in the carnivore fish gilthead seabream (Sparus aurata), a model species of aquaculture interest, and found that the saT1R gene repertoire consists of eight members including saT1R1, saT1R3 and six saT1R2a-f gene duplicates, adding further evidence to the evolutionary complexity of fishT1Rs families. To analyze saT1R taste functions, we first developed a stable gene reporter system based on Ca2+-dependent calcineurin/NFAT signaling to examine specifically in vitro the responses of a subset of saT1R heterodimers to L-amino acids (L-AAs) and sweet ligands. We show that although differentially tuned in sensitivity and magnitude of responses, saT1R1/R3, saT1R2a/R3 and saT1R2b/R3 may equally serve to transduce amino acid taste sensations. Furthermore, we present preliminary information on the potential involvement of the Gi protein alpha subunits saGαi1 and saGαi2 in taste signal transduction.
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Zhang W, Takahara T, Achiha T, Shibata H, Maki M. Cellular Ca 2+-Responding Nanoluciferase Reporter Gene System Directed by Tandemly Repeated Pseudo-palindromic NFAT-Response Elements. Methods Mol Biol 2019; 1929:95-109. [PMID: 30710269 DOI: 10.1007/978-1-4939-9030-6_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Luciferase reporter gene systems based on the NFAT-response element (RE) have been used to monitor intracellular Ca2+ elevation. However, Ca2+ mobilization agent (e.g., ionomycin) alone is not adequate to activate the currently often employed reporter gene that contains the NFAT-RE found in the IL2 promoter. In addition to activation of NFAT through the Ca2+-calmodulin/calcineurin pathway, activation of AP-1 as a partner transcription factor is essential for the IL2-based NFAT-RE system. Here, we describe a detailed method for the recently developed new reporter gene system containing the NFAT-RE from the IL8 promoter. This system enables us to monitor endpoint effects of Ca2+-mobilizing agonists independent of AP-1 activation.
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Affiliation(s)
- Wei Zhang
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Terunao Takahara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
| | - Takuya Achiha
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hideki Shibata
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
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