1
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Zhou D, Deng W, Zhou J, Deng H, Zheng J, Zhou Z. Influence of alkylation and esterification of 2-(4-methoxyphenoxy) propionic acid on sweet inhibition property and its manipulating mechanism. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2023. [DOI: 10.1080/10942912.2022.2154610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Dan Zhou
- College of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Wenting Deng
- College of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Junhan Zhou
- College of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Hongying Deng
- College of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Jianxian Zheng
- College of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Zhongkai Zhou
- College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, China
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2
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Sanematsu K, Yamamoto M, Nagasato Y, Kawabata Y, Watanabe Y, Iwata S, Takai S, Toko K, Matsui T, Wada N, Shigemura N. Prediction of dynamic allostery for the transmembrane domain of the sweet taste receptor subunit, TAS1R3. Commun Biol 2023; 6:340. [PMID: 37012338 PMCID: PMC10070457 DOI: 10.1038/s42003-023-04705-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 03/14/2023] [Indexed: 04/05/2023] Open
Abstract
The sweet taste receptor plays an essential role as an energy sensor by detecting carbohydrates. However, the dynamic mechanisms of receptor activation remain unclear. Here, we describe the interactions between the transmembrane domain of the G protein-coupled sweet receptor subunit, TAS1R3, and allosteric modulators. Molecular dynamics simulations reproduced species-specific sensitivity to ligands. We found that a human-specific sweetener, cyclamate, interacted with the mouse receptor as a negative allosteric modulator. Agonist-induced allostery during receptor activation was found to destabilize the intracellular part of the receptor, which potentially interfaces with the Gα subunit, through ionic lock opening. A common human variant (R757C) of the TAS1R3 exhibited a reduced response to sweet taste, in support of our predictions. Furthermore, histidine residues in the binding site acted as pH-sensitive microswitches to modulate the sensitivity to saccharin. This study provides important insights that may facilitate the prediction of dynamic activation mechanisms for other G protein-coupled receptors.
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Affiliation(s)
- Keisuke Sanematsu
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
- Oral Health/Brain Health/Total Health Research Center, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
- Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
| | - Masato Yamamoto
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
- Department of General Dentistry, Division of Interdisciplinary Dentistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yuki Nagasato
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
- Department of Bioresources and Biosciences, Faculty of Agriculture, Graduate School of Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Yuko Kawabata
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yu Watanabe
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Shusuke Iwata
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
- Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shingo Takai
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kiyoshi Toko
- Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Toshiro Matsui
- Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Department of Bioresources and Biosciences, Faculty of Agriculture, Graduate School of Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Naohisa Wada
- Department of General Dentistry, Division of Interdisciplinary Dentistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Noriatsu Shigemura
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
- Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
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3
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Deng W, Zhou D, Li J, Zheng J, Zhou Z. A Potent Mechanism for Revealing Structurally Manipulated Sweetness Inhibitory Property of Lactisole Derivatives. Food Chem 2022. [DOI: 10.1016/j.foodchem.2022.134769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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4
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Mafi A, Kim SK, Chou KC, Güthrie B, Goddard WA. Predicted Structure of Fully Activated Tas1R3/1R3' Homodimer Bound to G Protein and Natural Sugars: Structural Insights into G Protein Activation by a Class C Sweet Taste Homodimer with Natural Sugars. J Am Chem Soc 2021; 143:16824-16838. [PMID: 34585929 DOI: 10.1021/jacs.1c08839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The Tas1R3 G protein-coupled receptor constitutes the main component of sweet taste sensory response in humans via forming a heterodimer with Tas1R2 or a homodimer with Tas1R3. The Tas1R3/1R3' homodimer serves as a low-affinity sweet taste receptor, stimulating gustducin G protein (GGust) signaling in the presence of a high concentration of natural sugars. This provides an additional means to detect the taste of natural sugars, thereby differentiating the flavors between natural sugars and artificial sweeteners. We report here the predicted 3D structure of active state Tas1R3/1R3' homodimer complexed with heterotrimeric GGust and sucrose. We discovered that the GGust makes ionic anchors to intracellular loops 1 and 2 of Tas1R3 while the Gα-α5 helix engages the cytoplasmic region extensively through salt bridge and hydrophobic interactions. We show that in the activation of this complex the Venus flytrap domains of the homodimer undergo a remarkable twist up to ∼100° rotation around the vertical axis to adopt a closed-closed conformation while the intracellular region relaxes to an open-open conformation. We find that binding of sucrose to the homodimer stabilizes a preactivated conformation with a largely open intracellular region that recruits and activates the GGust. Upon activation, the Gα subunit spontaneously opens up the nucleotide-binding site, making nucleotide exchange facile for signaling. This activation of GGust promotes the interdomain twist of the Venus flytrap domains. These structures and transformations could potentially be a basis for the design of new sweeteners with higher activity and less unpleasant flavors.
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Affiliation(s)
- Amirhossein Mafi
- Materials and Process Simulation Center (139-74), California Institute of Technology, Pasadena, California 91125, United States
| | - Soo-Kyung Kim
- Materials and Process Simulation Center (139-74), California Institute of Technology, Pasadena, California 91125, United States
| | - Keng C Chou
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Brian Güthrie
- Cargill Global Food Research, Wayzata, Minnesota 55391, United States
| | - William A Goddard
- Materials and Process Simulation Center (139-74), California Institute of Technology, Pasadena, California 91125, United States
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5
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Ben Mordechay E, Mordehay V, Tarchitzky J, Chefetz B. Pharmaceuticals in edible crops irrigated with reclaimed wastewater: Evidence from a large survey in Israel. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:126184. [PMID: 34492955 DOI: 10.1016/j.jhazmat.2021.126184] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 06/13/2023]
Abstract
Pharmaceuticals and other contaminants of emerging concern (CECs) are continuously introduced into the agroecosystem via reclaimed wastewater irrigation, a common agricultural practice in water-scarce regions. Although reclaimed wastewater irrigated crops are sold and consumed, only limited information is available on the occurrence of pharmaceuticals and other CECs in edible produce. Here, we report data on CECs in irrigation water, soils, and crops collected from 445 commercial fields irrigated with reclaimed wastewater in Israel. The following produce were analyzed: leafy greens, carrot, potato, tomato, orange, tangerine, avocado, and banana. Pharmaceuticals and CECs were found in quantifiable levels in all irrigation water, soils, and plants (>99.6%). Leafy greens exhibited the largest number and the highest concentration of pharmaceuticals. Within the same crop, contamination levels varied due to wastewater source and quality of treatment, and soil characteristics. Anticonvulsants (carbamazepine, lamotrigine, and gabapentin) were the most dominant therapeutic group found in the reclaimed wastewater-soil-plant continuum. Antimicrobials were detected in ~85% of the water and soil samples, however they exhibited low detection frequencies and concentrations in produce. Irrigation with reclaimed wastewater should be limited to crops where the risk for pharmaceutical transfer to the food chain is minimal.
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Affiliation(s)
- Evyatar Ben Mordechay
- Department of Soil and Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
| | - Vered Mordehay
- Department of Soil and Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
| | - Jorge Tarchitzky
- Department of Soil and Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
| | - Benny Chefetz
- Department of Soil and Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel.
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6
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Nakagita T, Taketani C, Narukawa M, Hirokawa T, Kobayashi T, Misaka T. Ibuprofen, a Nonsteroidal Anti-Inflammatory Drug, is a Potent Inhibitor of the Human Sweet Taste Receptor. Chem Senses 2021; 45:667-673. [PMID: 32832995 DOI: 10.1093/chemse/bjaa057] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A sweet taste receptor is composed of heterodimeric G-protein-coupled receptors T1R2 and T1R3. Although there are many sweet tastants, only a few compounds have been reported as negative allosteric modulators (NAMs), such as lactisole, its structural derivative 2,4-DP, and gymnemic acid. In this study, candidates for NAMs of the sweet taste receptor were explored, focusing on the structural motif of lactisole. Ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), has an α-methylacetic acid moiety, and this structure is also shared by lactisole and 2,4-DP. When ibuprofen was applied together with 1 mM aspartame to the cells that stably expressed the sweet taste receptor, it inhibited the receptor activity in a dose-dependent manner. The IC50 value of ibuprofen against the human sweet taste receptor was calculated as approximately 12 μM, and it was almost equal to that of 2,4-DP, which is known as the most potent NAM for the receptor to date. On the other hand, when the inhibitory activities of other profens were examined, naproxen also showed relatively potent NAM activity against the receptor. The results from both mutant analysis for the transmembrane domain (TMD) of T1R3 and docking simulation strongly suggest that ibuprofen and naproxen interact with T1R3-TMD, similar to lactisole and 2,4-DP. However, although 2,4-DP and ibuprofen had almost the same inhibitory activities, these activities were acquired by filling different spaces of the ligand pocket of T1R3-TMD; this knowledge could lead to the rational design of a novel NAM against the sweet taste receptor.
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Affiliation(s)
- Tomoya Nakagita
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan.,Proteo-Science Center, Ehime University, Bunkyo-cho, Matsuyama, Ehime, Japan
| | - Chiaki Taketani
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Masataka Narukawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Takatsugu Hirokawa
- Molecular Profiling Research Center for Drug Discovery, National Institutes of Advanced Industrial Science and Technology, Aomi, Koto-ku, Tokyo, Japan.,Department of Chemical Biology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Takuya Kobayashi
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
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7
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Abstract
Umami, the fifth taste, has been recognized as a legitimate taste modality only recently relative to the other tastes. Dozens of compounds from vastly different chemical classes elicit a savory (also called umami) taste. The prototypical umami substance glutamic acid or its salt monosodium glutamate (MSG) is present in numerous savory food sources or ingredients such as kombu (edible kelp), beans, soy sauce, tomatoes, cheeses, mushrooms, and certain meats and fish. Derivatives of glutamate (Glu), other amino acids, nucleotides, and small peptides can also elicit or modulate umami taste. In addition, many potent umami tasting compounds structurally unrelated to amino acids, nucleotides, and MSG have been either synthesized or discovered as naturally occurring in plants and other substances. Over the last 20 years several receptors have been suggested to mediate umami taste, including members of the metabotropic and ionotropic Glu receptor families, and more recently, the heterodimeric G protein-coupled receptor, T1R1/T1R3. Careful assessment of representative umami tasting molecules from several different chemical classes shows activation of T1R1/T1R3 with the expected rank order of potency in cell-based assays. Moreover, 5'-ribonucleotides, molecules known to enhance the savory note of Glu, considerably enhance the effect of MSG on T1R1/T1R3 in vitro. Binding sites are found on at least 4 distinct locations on T1R1/T1R3, explaining the propensity of the receptor to being activated or modulated by many structurally distinct compounds and these binding sites allosterically interact to modulate receptor activity. Activation of T1R1/T1R3 by all known umami substances evaluated and the receptor's pharmacological properties are sufficient to explain the basic human sensory experience of savory taste and it is therefore unlikely that other receptors are involved.
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8
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Hashimoto M, Nakagita T, Misaka T. Recent progress in the use of diaziridine-based sweetener derivatives to elucidate the chemoreception mechanism of the sweet taste receptor. RSC Adv 2021; 11:32236-32247. [PMID: 35495529 PMCID: PMC9041848 DOI: 10.1039/d1ra04831g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/21/2021] [Indexed: 11/21/2022] Open
Abstract
The review summarized recent progress for the elucidation of the chemoreception mechanism of sweet taste receptor–sweetener interactions with photoaffinity labeling.
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Affiliation(s)
- Makoto Hashimoto
- Division of Applied Science, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan
| | - Tomoya Nakagita
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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9
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Ahmad R, Dalziel JE. G Protein-Coupled Receptors in Taste Physiology and Pharmacology. Front Pharmacol 2020; 11:587664. [PMID: 33390961 PMCID: PMC7774309 DOI: 10.3389/fphar.2020.587664] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
Heterotrimeric G protein-coupled receptors (GPCRs) comprise the largest receptor family in mammals and are responsible for the regulation of most physiological functions. Besides mediating the sensory modalities of olfaction and vision, GPCRs also transduce signals for three basic taste qualities of sweet, umami (savory taste), and bitter, as well as the flavor sensation kokumi. Taste GPCRs reside in specialised taste receptor cells (TRCs) within taste buds. Type I taste GPCRs (TAS1R) form heterodimeric complexes that function as sweet (TAS1R2/TAS1R3) or umami (TAS1R1/TAS1R3) taste receptors, whereas Type II are monomeric bitter taste receptors or kokumi/calcium-sensing receptors. Sweet, umami and kokumi receptors share structural similarities in containing multiple agonist binding sites with pronounced selectivity while most bitter receptors contain a single binding site that is broadly tuned to a diverse array of bitter ligands in a non-selective manner. Tastant binding to the receptor activates downstream secondary messenger pathways leading to depolarization and increased intracellular calcium in TRCs, that in turn innervate the gustatory cortex in the brain. Despite recent advances in our understanding of the relationship between agonist binding and the conformational changes required for receptor activation, several major challenges and questions remain in taste GPCR biology that are discussed in the present review. In recent years, intensive integrative approaches combining heterologous expression, mutagenesis and homology modeling have together provided insight regarding agonist binding site locations and molecular mechanisms of orthosteric and allosteric modulation. In addition, studies based on transgenic mice, utilizing either global or conditional knock out strategies have provided insights to taste receptor signal transduction mechanisms and their roles in physiology. However, the need for more functional studies in a physiological context is apparent and would be enhanced by a crystallized structure of taste receptors for a more complete picture of their pharmacological mechanisms.
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Affiliation(s)
- Raise Ahmad
- Food Nutrition and Health Team, Food and Bio-based Products Group, AgResearch, Palmerston North, New Zealand
| | - Julie E Dalziel
- Food Nutrition and Health Team, Food and Bio-based Products Group, AgResearch, Palmerston North, New Zealand
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10
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Davis TME. Fenofibrate and Impaired Taste Perception in Type 2 Diabetes. AMERICAN JOURNAL OF CASE REPORTS 2020; 21:e927647. [PMID: 33214542 PMCID: PMC7684425 DOI: 10.12659/ajcr.927647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Patient: Female, 65-year-old Final Diagnosis: Type 2 diabetes Symptoms: Loss of sweet taste Medication: Fenofibrate Clinical Procedure: Drug challenge/dechallenge/rechallenge Specialty: Endocrinology and Metabolic
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Affiliation(s)
- Timothy M E Davis
- Medical School, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia.,Department of General Medicine, Fremantle Hospital, Fremantle, Western Australia, Australia.,Department of Endocrinology, Fremantle Hospital, Fremantle, Western Australia, Australia
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11
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Nakagita T, Ishida A, Tachrim ZP, Wang L, Misaka T, Hashimoto M. Asymmetric Synthesis of Photophore-Containing Lactisole Derivatives to Elucidate Sweet Taste Receptors. Molecules 2020; 25:molecules25122790. [PMID: 32560345 PMCID: PMC7355818 DOI: 10.3390/molecules25122790] [Citation(s) in RCA: 3] [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] [Received: 05/29/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 11/23/2022] Open
Abstract
Lactisole, which has a 2-phenoxy propionic acid skeleton, is well-known as an inhibitor of sweet taste receptors. We recently revealed some of the structure–activity relationships of the aromatic ring and chiral center of lactisole. Photoaffinity labeling is one of the common chemical biology methods to elucidate the interaction between bioactive compounds and biomolecules. In this paper, the novel asymmetric synthesis of lactisole derivatives with common photophores (benzophenone, azide and trifluoromethyldiazirine) for photoaffinity labeling is described. The synthetic compounds are subjected to cell-based sweet taste receptors, and the substitution with trifluoromethyldiazirinyl photophore shows the highest affinity to the receptor of the synthesized compounds.
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Affiliation(s)
- Tomoya Nakagita
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan; (T.N.); (T.M.)
- Proteo-Science Center, Ehime University, Ehime 791-8577, Japan
| | - Akiko Ishida
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan; (A.I.); (Z.P.T.); (L.W.)
| | - Zetryana Puteri Tachrim
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan; (A.I.); (Z.P.T.); (L.W.)
- Program Study of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia
| | - Lei Wang
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan; (A.I.); (Z.P.T.); (L.W.)
- Department of Pharmacy, School of Chemical Engineering, Dalian University of Technology, Dalian 116023, China
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan; (T.N.); (T.M.)
| | - Makoto Hashimoto
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan; (A.I.); (Z.P.T.); (L.W.)
- Correspondence: ; Tel.: +81-11-7063849
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12
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Nakagita T, Ishida A, Matsuya T, Kobayashi T, Narukawa M, Hirokawa T, Hashimoto M, Misaka T. Structural insights into the differences among lactisole derivatives in inhibitory mechanisms against the human sweet taste receptor. PLoS One 2019; 14:e0213552. [PMID: 30883570 PMCID: PMC6422327 DOI: 10.1371/journal.pone.0213552] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 02/23/2019] [Indexed: 11/22/2022] Open
Abstract
Lactisole, an inhibitor of the human sweet taste receptor, has a 2-phenoxypropionic acid skeleton and has been shown to interact with the transmembrane domain of the T1R3 subunit (T1R3-TMD) of the receptor. Another inhibitor, 2,4-DP, which shares the same molecular skeleton as lactisole, was confirmed to be approximately 10-fold more potent in its inhibitory activity than lactisole; however the structural basis of their inhibitory mechanisms against the receptor remains to be elucidated. Crystal structures of the TMD of metabotropic glutamate receptors, which along with T1Rs are categorized as class C G-protein coupled receptors, have recently been reported and made it possible to create an accurate structural model for T1R3-TMD. In this study, the detailed structural mechanism underlying sweet taste inhibition was characterized by comparing the action of lactisole on T1R3-TMD with that of 2,4-DP. We first performed a series of experiments using cultured cells expressing the sweet taste receptor with mutations and examined the interactions with these inhibitors. Based on the results, we next performed docking simulations and then applied molecular dynamics-based energy minimization. Our analyses clearly revealed that the (S)-isomers of both lactisole and 2,4-DP, interacted with the same seven residues in T1R3-TMD and that the inhibitory potencies of those inhibitors were mainly due to stabilizing interactions mediated via their carboxyl groups in the vertical dimension of the ligand pocket of T1R3-TMD. In addition, 2,4-DP engaged in a hydrophobic interaction mediated by its o-Cl group, and this interaction may be chiefly responsible for the higher inhibitory potency of 2,4-DP.
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Affiliation(s)
- Tomoya Nakagita
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akiko Ishida
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Takumi Matsuya
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takuya Kobayashi
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masataka Narukawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takatsugu Hirokawa
- Molecular Profiling Research Center for Drug Discovery, National Institutes of Advanced Industrial Science and Technology, Tokyo, Japan
- Department of Chemical Biology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Makoto Hashimoto
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- * E-mail:
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13
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Luddi A, Governini L, Wilmskötter D, Gudermann T, Boekhoff I, Piomboni P. Taste Receptors: New Players in Sperm Biology. Int J Mol Sci 2019; 20:E967. [PMID: 30813355 PMCID: PMC6413048 DOI: 10.3390/ijms20040967] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/13/2019] [Accepted: 02/18/2019] [Indexed: 12/21/2022] Open
Abstract
Taste receptors were first described as sensory receptors located on the tongue, where they are expressed in small clusters of specialized epithelial cells. However, more studies were published in recent years pointing to an expression of these proteins not only in the oral cavity but throughout the body and thus to a physiological role beyond the tongue. The recent observation that taste receptors and components of the coupled taste transduction cascade are also expressed during the different phases of spermatogenesis as well as in mature spermatozoa from mouse to humans and the overlap between the ligand spectrum of taste receptors with compounds in the male and female reproductive organs makes it reasonable to assume that sperm "taste" these different cues in their natural microenvironments. This assumption is assisted by the recent observations of a reproductive phenotype of different mouse lines carrying a targeted deletion of a taste receptor gene as well as the finding of a significant correlation between human male infertility and some polymorphisms in taste receptors genes. In this review, we depict recent findings on the role of taste receptors in male fertility, especially focusing on their possible involvement in mechanisms underlying spermatogenesis and post testicular sperm maturation. We also highlight the impact of genetic deletions of taste receptors, as well as their polymorphisms on male reproduction.
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Affiliation(s)
- Alice Luddi
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy.
| | - Laura Governini
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy.
| | - Dorke Wilmskötter
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, 80539 Munich, Germany.
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, 80539 Munich, Germany.
| | - Ingrid Boekhoff
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, 80539 Munich, Germany.
| | - Paola Piomboni
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy.
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Abstract
The study of taste has been guided throughout much of its history by the conceptual framework of psychophysics, where the focus was on quantification of the subjective experience of the taste sensations. By the mid-20th century, data from physiologic studies had accumulated sufficiently to assemble a model for the function of receptors that must mediate the initial stimulus of tastant molecules in contact with the tongue. But the study of taste as a receptor-mediated event did not gain momentum until decades later when the actual receptor proteins and attendant signaling mechanisms were identified and localized to the highly specialized taste-responsive cells of the tongue. With those discoveries a new opportunity to examine taste as a function of receptor activity has come into focus. Pharmacology is the science designed specifically for the experimental interrogation and quantitative characterization of receptor function at all levels of inquiry from molecules to behavior. This review covers the history of some of the major concepts that have shaped thinking and experimental approaches to taste, the seminal discoveries that have led to elucidation of receptors for taste, and how applying principles of receptor pharmacology can enhance understanding of the mechanisms of taste physiology and perception.
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Affiliation(s)
- R Kyle Palmer
- Opertech Bio, Inc., Pennovation Center, Philadelphia, Pennsylvania
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16
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Extraoral Taste Receptor Discovery: New Light on Ayurvedic Pharmacology. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017. [PMID: 28642799 PMCID: PMC5469997 DOI: 10.1155/2017/5435831] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
More and more research studies are revealing unexpectedly important roles of taste for health and pathogenesis of various diseases. Only recently it has been shown that taste receptors have many extraoral locations (e.g., stomach, intestines, liver, pancreas, respiratory system, heart, brain, kidney, urinary bladder, pancreas, adipose tissue, testis, and ovary), being part of a large diffuse chemosensory system. The functional implications of these taste receptors widely dispersed in various organs or tissues shed a new light on several concepts used in ayurvedic pharmacology (dravyaguna vijnana), such as taste (rasa), postdigestive effect (vipaka), qualities (guna), and energetic nature (virya). This review summarizes the significance of extraoral taste receptors and transient receptor potential (TRP) channels for ayurvedic pharmacology, as well as the biological activities of various types of phytochemical tastants from an ayurvedic perspective. The relative importance of taste (rasa), postdigestive effect (vipaka), and energetic nature (virya) as ethnopharmacological descriptors within Ayurveda boundaries will also be discussed.
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Kochem M, Breslin PAS. Clofibrate inhibits the umami-savory taste of glutamate. PLoS One 2017; 12:e0172534. [PMID: 28248971 PMCID: PMC5332072 DOI: 10.1371/journal.pone.0172534] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 02/06/2017] [Indexed: 01/21/2023] Open
Abstract
In humans, umami taste can increase the palatability of foods rich in the amino acids glutamate and aspartate and the 5'-ribonucleotides IMP and GMP. Umami taste is transduced, in part, by T1R1-T1R3, a heteromeric G-protein coupled receptor. Umami perception is inhibited by sodium lactisole, which binds to the T1R3 subunit in vitro. Lactisole is structurally similar to the fibrate drugs. Clofibric acid, a lipid lowering drug, also binds the T1R3 subunit in vitro. The purpose of this study was to determine whether clofibric acid inhibits the umami taste of glutamate in human subjects. Ten participants rated the umami taste intensity elicited by 20 mM monosodium glutamate (MSG) mixed with varying concentrations of clofibric acid (0 to 16 mM). In addition, fourteen participants rated the effect of 1.4 mM clofibric acid on umami enhancement by 5' ribonucleotides. Participants were instructed to rate perceived intensity using a general Labeled Magnitude Scale (gLMS). Each participant was tested in triplicate. Clofibric acid inhibited umami taste intensity from 20 mM MSG in a dose dependent manner. Whereas MSG neat elicited "moderate" umami taste intensity, the addition of 16 mM clofibric acid elicited only "weak" umami intensity on average, and in some subjects no umami taste was elicited. We further show that 1.4 mM clofibric acid suppressed umami enhancement from GMP, but not from IMP. This study provides in vivo evidence that clofibric acid inhibits glutamate taste perception, presumably via T1R1-T1R3 inhibition, and lends further evidence that the T1R1-T1R3 receptor is the principal umami receptor in humans. T1R receptors are expressed extra-orally throughout the alimentary tract and in regulatory organs and are known to influence glucose and lipid metabolism. Whether clofibric acid as a lipid-lowering drug affects human metabolism, in part, through T1R inhibition warrants further examination.
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Affiliation(s)
- Matthew Kochem
- Rutgers University Department of Nutritional Sciences, New Brunswick, NJ, United States of America
| | - Paul A. S. Breslin
- Rutgers University Department of Nutritional Sciences, New Brunswick, NJ, United States of America
- Monell Chemical Senses Center Philadelphia, PA, United States of America
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18
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Abstract
T1R2-T1R3 is a heteromeric receptor that binds sugars, high potency sweeteners, and sweet taste blockers. In rodents, T1R2-T1R3 is largely responsible for transducing sweet taste perception. T1R2-T1R3 is also expressed in non-taste tissues, and a growing body of evidence suggests that it helps regulate glucose and lipid metabolism. It was previously shown that clofibric acid, a blood lipid-lowering drug, binds T1R2-T1R3 and inhibits its activity in vitro The purpose of this study was to determine whether clofibric acid inhibits sweetness perception in humans and is, therefore, a T1R2-T1R3 antagonist in vivo Fourteen participants rated the sweetness intensity of 4 sweeteners (sucrose, sucralose, Na cyclamate, acesulfame K) across a broad range of concentrations. Each sweetener was prepared in solution neat and in mixture with either clofibric acid or lactisole. Clofibric acid inhibited sweetness of every sweetener. Consistent with competitive binding, inhibition by clofibric acid was diminished with increasing sweetener concentration. This study provides in vivo evidence that the lipid-lowering drug clofibric acid inhibits sweetness perception and is, therefore, a T1R carbohydrate receptor inhibitor. Our results are consistent with previous in vitro findings. Given that T1R2-T1R3 may in part regulate glucose and lipid metabolism, future studies should investigate the metabolic effects of T1R inhibition.
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Affiliation(s)
- Matthew Kochem
- Department of Nutritional Sciences, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, USA and
| | - Paul A S Breslin
- Department of Nutritional Sciences, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, USA and
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA
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In vitro evidence in rainbow trout supporting glucosensing mediated by sweet taste receptor, LXR, and mitochondrial activity in Brockmann bodies, and sweet taste receptor in liver. Comp Biochem Physiol B Biochem Mol Biol 2016; 200:6-16. [DOI: 10.1016/j.cbpb.2016.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/25/2016] [Accepted: 04/27/2016] [Indexed: 12/31/2022]
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Otero-Rodiño C, Velasco C, Álvarez-Otero R, López-Patiño MA, Míguez JM, Soengas JL. In vitro evidence supports the presence of glucokinase-independent glucosensing mechanisms in hypothalamus and hindbrain of rainbow trout. ACTA ACUST UNITED AC 2016; 219:1750-9. [PMID: 27026717 DOI: 10.1242/jeb.137737] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/03/2016] [Indexed: 11/20/2022]
Abstract
We previously obtained evidence in rainbow trout for the presence and response to changes in circulating levels of glucose (induced by intraperitoneal hypoglycaemic and hyperglycaemic treatments) of glucosensing mechanisms based on liver X receptor (LXR), mitochondrial production of reactive oxygen species (ROS) leading to increased expression of uncoupling protein 2 (UCP2), and sweet taste receptor in the hypothalamus, and on sodium/glucose co-transporter 1 (SGLT-1) in hindbrain. However, these effects of glucose might be indirect. Therefore, we evaluated the response of parameters related to these glucosensing mechanisms in a first experiment using pooled sections of hypothalamus and hindbrain incubated for 6 h at 15°C in modified Hanks' medium containing 2, 4 or 8 mmol l(-1) d-glucose. The responses observed in some cases were consistent with glucosensing capacity. In a second experiment, pooled sections of hypothalamus and hindbrain were incubated for 6 h at 15°C in modified Hanks' medium with 8 mmol l(-1) d-glucose alone (control) or containing 1 mmol l(-1) phloridzin (SGLT-1 antagonist), 20 µmol l(-1) genipin (UCP2 inhibitor), 1 µmol l(-1) trolox (ROS scavenger), 100 µmol l(-1) bezafibrate (T1R3 inhibitor) and 50 µmol l(-1) geranyl-geranyl pyrophosphate (LXR inhibitor). The response observed in the presence of these specific inhibitors/antagonists further supports the proposal that critical components of the different glucosensing mechanisms are functioning in rainbow trout hypothalamus and hindbrain.
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Affiliation(s)
- Cristina Otero-Rodiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain
| | - Cristina Velasco
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain
| | - Rosa Álvarez-Otero
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain
| | - Marcos A López-Patiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain
| | - Jesús M Míguez
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain
| | - José L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain
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21
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Abstract
In flies and humans, bitter chemicals are known to inhibit sugar detection, but the adaptive role of this inhibition is often overlooked. At best, this inhibition is described as contributing to the rejection of potentially toxic food, but no studies have addressed the relative importance of the direct pathway that involves activating bitter-sensitive cells versus the indirect pathway represented by the inhibition of sugar detection. Using toxins to selectively ablate or inactivate populations of bitter-sensitive cells, we assessed the behavioral responses of flies to sucrose mixed with strychnine (which activates bitter-sensitive cells and inhibits sugar detection) or with L-canavanine (which only activates bitter-sensitive cells). As expected, flies with ablated bitter-sensitive cells failed to detect L-canavanine mixed with sucrose in three different feeding assays (proboscis extension responses, capillary feeding, and two-choice assays). However, such flies were still able to avoid strychnine mixed with sucrose. By means of electrophysiological recordings, we established that bitter molecules differ in their potency to inhibit sucrose detection and that sugar-sensing inhibition affects taste cells on the proboscis and the legs. The optogenetic response of sugar-sensitive cells was not reduced by strychnine, thus suggesting that this inhibition is linked directly to sugar transduction. We postulate that sugar-sensing inhibition represents a mechanism in insects to prevent ingesting harmful substances occurring within mixtures.
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22
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Extrasensory perception: odorant and taste receptors beyond the nose and mouth. Pharmacol Ther 2013; 142:41-61. [PMID: 24280065 DOI: 10.1016/j.pharmthera.2013.11.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 11/04/2013] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of transmembrane receptors and are prime therapeutic targets. The odorant and taste receptors account for over half of the GPCR repertoire, yet they are generally excluded from large-scale, drug candidate analyses. Accumulating molecular evidence indicates that the odorant and taste receptors are widely expressed throughout the body and functional beyond the oronasal cavity - with roles including nutrient sensing, autophagy, muscle regeneration, regulation of gut motility, protective airway reflexes, bronchodilation, and respiratory disease. Given this expanding array of actions, the restricted perception of these GPCRs as mere mediators of smell and taste is outdated. Moreover, delineation of the precise actions of odorant and taste GPCRs continues to be hampered by the relative paucity of selective and specific experimental tools, as well as the lack of defined receptor pharmacology. In this review, we summarize the evidence for expression and function of odorant and taste receptors in tissues beyond the nose and mouth, and we highlight their broad potential in physiology and pathophysiology.
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23
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Mosinger B, Redding KM, Parker MR, Yevshayeva V, Yee KK, Dyomina K, Li Y, Margolskee RF. Genetic loss or pharmacological blockade of testes-expressed taste genes causes male sterility. Proc Natl Acad Sci U S A 2013; 110:12319-24. [PMID: 23818598 PMCID: PMC3725061 DOI: 10.1073/pnas.1302827110] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
TAS1R taste receptors and their associated heterotrimeric G protein gustducin are involved in sugar and amino acid sensing in taste cells and in the gastrointestinal tract. They are also strongly expressed in testis and sperm, but their functions in these tissues were previously unknown. Using mouse models, we show that the genetic absence of both TAS1R3, a component of sweet and amino acid taste receptors, and the gustducin α-subunit GNAT3 leads to male-specific sterility. To gain further insight into this effect, we generated a mouse model that expressed a humanized form of TAS1R3 susceptible to inhibition by the antilipid medication clofibrate. Sperm formation in animals without functional TAS1R3 and GNAT3 is compromised, with malformed and immotile sperm. Furthermore, clofibrate inhibition of humanized TAS1R3 in the genetic background of Tas1r3(-/-), Gnat3(-/-) doubly null mice led to inducible male sterility. These results indicate a crucial role for these extraoral "taste" molecules in sperm development and maturation. We previously reported that blocking of human TAS1R3, but not mouse TAS1R3, can be achieved by common medications or chemicals in the environment. We hypothesize that even low levels of these compounds can lower sperm count and negatively affect human male fertility, which common mouse toxicology assays would not reveal. Conversely, we speculate that TAS1R3 and GNAT3 activators may help infertile men, particularly those that are affected by some of the mentioned inhibitors and/or are diagnosed with idiopathic infertility involving signaling pathway of these receptors.
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24
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Wauson EM, Lorente-Rodríguez A, Cobb MH. Minireview: Nutrient sensing by G protein-coupled receptors. Mol Endocrinol 2013; 27:1188-97. [PMID: 23820899 DOI: 10.1210/me.2013-1100] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are membrane proteins that recognize molecules in the extracellular milieu and transmit signals inside cells to regulate their behaviors. Ligands for many GPCRs are hormones or neurotransmitters that direct coordinated, stereotyped adaptive responses. Ligands for other GPCRs provide information to cells about the extracellular environment. Such information facilitates context-specific decision making that may be cell autonomous. Among ligands that are important for cellular decisions are amino acids, required for continued protein synthesis, as metabolic starting materials and energy sources. Amino acids are detected by a number of class C GPCRs. One cluster of amino acid-sensing class C GPCRs includes umami and sweet taste receptors, GPRC6A, and the calcium-sensing receptor. We have recently found that the umami taste receptor heterodimer T1R1/T1R3 is a sensor of amino acid availability that regulates the activity of the mammalian target of rapamycin. This review focuses on an array of findings on sensing amino acids and sweet molecules outside of neurons by this cluster of class C GPCRs and some of the physiologic processes regulated by them.
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Affiliation(s)
- Eric M Wauson
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9041, USA
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25
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Nilius B, Appendino G. Spices: the savory and beneficial science of pungency. Rev Physiol Biochem Pharmacol 2013; 164:1-76. [PMID: 23605179 DOI: 10.1007/112_2013_11] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Spicy food does not only provide an important hedonic input in daily life, but has also been anedoctically associated to beneficial effects on our health. In this context, the discovery of chemesthetic trigeminal receptors and their spicy ligands has provided the mechanistic basis and the pharmacological means to investigate this enticing possibility. This review discusses in molecular terms the connection between the neurophysiology of pungent spices and the "systemic" effects associated to their trigeminality. It commences with a cultural and historical overview on the Western fascination for spices, and, after analysing in detail the mechanisms underlying the trigeminality of food, the main dietary players from the transient receptor potential (TRP) family of cation channels are introduced, also discussing the "alien" distribution of taste receptors outside the oro-pharingeal cavity. The modulation of TRPV1 and TRPA1 by spices is next described, discussing how spicy sensations can be turned into hedonic pungency, and analyzing the mechanistic bases for the health benefits that have been associated to the consumption of spices. These include, in addition to a beneficial modulation of gastro-intestinal and cardio-vascular function, slimming, the optimization of skeletal muscle performance, the reduction of chronic inflammation, and the prevention of metabolic syndrome and diabetes. We conclude by reviewing the role of electrophilic spice constituents on cancer prevention in the light of their action on pro-inflammatory and pro-cancerogenic nuclear factors like NFκB, and on their interaction with the electrophile sensor protein Keap1 and the ensuing Nrf2-mediated transcriptional activity. Spicy compounds have a complex polypharmacology, and just like any other bioactive agent, show a balance of beneficial and bad actions. However, at least for moderate consumption, the balance seems definitely in favour of the positive side, suggesting that a spicy diet, a caveman-era technology, could be seriously considered in addition to caloric control and exercise as a measurement to prevent and control many chronic diseases associate to malnutrition from a Western diet.
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Affiliation(s)
- Bernd Nilius
- KU Leuven Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, Leuven, Belgium,
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26
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Sigoillot M, Brockhoff A, Meyerhof W, Briand L. Sweet-taste-suppressing compounds: current knowledge and perspectives of application. Appl Microbiol Biotechnol 2012; 96:619-30. [PMID: 22983596 DOI: 10.1007/s00253-012-4387-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 01/07/2023]
Abstract
Sweet-tasting compounds are recognized by a heterodimeric receptor composed of the taste receptor, type 1, members 2 (T1R2) and 3 (T1R3) located in the mouth. This receptor is also expressed in the gut where it is involved in intestinal absorption, metabolic regulation, and glucose homeostasis. These metabolic functions make the sweet taste receptor a potential novel therapeutic target for the treatment of obesity and related metabolic dysfunctions such as diabetes. Existing sweet taste inhibitors or blockers that are still in development would constitute promising therapeutic agents. In this review, we will summarize the current knowledge of sweet taste inhibitors, including a sweet-taste-suppressing protein named gurmarin, which is only active on rodent sweet taste receptors but not on that of humans. In addition, their potential applications as therapeutic tools are discussed.
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Affiliation(s)
- Maud Sigoillot
- Centre des Sciences du Goût et de l'Alimentation, UMR-1324 INRA, UMR-6265 CNRS, Université de Bourgogne, 21000, Dijon, France
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27
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Wauson EM, Zaganjor E, Lee AY, Guerra ML, Ghosh AB, Bookout AL, Chambers CP, Jivan A, McGlynn K, Hutchison MR, Deberardinis RJ, Cobb MH. The G protein-coupled taste receptor T1R1/T1R3 regulates mTORC1 and autophagy. Mol Cell 2012; 47:851-62. [PMID: 22959271 DOI: 10.1016/j.molcel.2012.08.001] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 06/14/2012] [Accepted: 08/02/2012] [Indexed: 12/11/2022]
Abstract
Cells continually assess their energy and nutrient state to maintain growth and survival and engage necessary homeostatic mechanisms. Cell-autonomous responses to the fed state require the surveillance of the availability of amino acids and other nutrients. The mammalian target of rapamycin complex 1 (mTORC1) integrates information on nutrient and amino acid availability to support protein synthesis and cell growth. We identify the G protein-coupled receptor (GPCR) T1R1/T1R3 as a direct sensor of the fed state and amino acid availability. Knocking down this receptor, which is found in most tissues, reduces the ability of amino acids to signal to mTORC1. Interfering with this receptor alters localization of mTORC1, downregulates expression of pathway inhibitors, upregulates key amino acid transporters, blocks translation initiation, and induces autophagy. These findings reveal a mechanism for communicating amino acid availability through a GPCR to mTORC1 in mammals.
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Affiliation(s)
- Eric M Wauson
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Dallas, TX 75390-9041, USA
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Maillet ÉL. Récepteurs gustatifs des molécules sucrantes et antisucrantes. Med Sci (Paris) 2011; 27:177-82. [DOI: 10.1051/medsci/2011272177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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