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May CE, Dus M. Confection Confusion: Interplay Between Diet, Taste, and Nutrition. Trends Endocrinol Metab 2021; 32:95-105. [PMID: 33384209 PMCID: PMC8021035 DOI: 10.1016/j.tem.2020.11.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/12/2020] [Accepted: 11/24/2020] [Indexed: 12/18/2022]
Abstract
Although genetics shapes our sense of taste to prefer some foods over others, taste sensation is plastic and changes with age, disease state, and nutrition. We have known for decades that diet composition can influence the way we perceive foods, but many questions remain unanswered, particularly regarding the effects of chemosensory plasticity on feeding behavior. Here, we review recent evidence on the effects of high-nutrient diets, especially high dietary sugar, on sweet taste in vinegar flies, rodents, and humans, and discuss open questions about molecular and neural mechanisms and research priorities. We also consider ways in which diet-dependent chemosensory plasticity may influence food intake and play a role in the etiology of obesity and metabolic disease. Understanding the interplay between nutrition, taste sensation, and feeding will help us define the role of the food environment in mediating chronic disease and design better public health strategies to combat it.
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Affiliation(s)
- Christina E May
- Neuroscience Graduate Program, The University of Michigan, Ann Arbor, MI, USA; Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109, USA
| | - Monica Dus
- Neuroscience Graduate Program, The University of Michigan, Ann Arbor, MI, USA; Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109, USA.
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Kashio M. Thermosensation involving thermo-TRPs. Mol Cell Endocrinol 2021; 520:111089. [PMID: 33227348 DOI: 10.1016/j.mce.2020.111089] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 02/02/2020] [Accepted: 11/17/2020] [Indexed: 12/13/2022]
Abstract
The transient receptor potential (TRP) channels constitute a superfamily of large ion channels that are activated by a wide range of chemical, mechanical and thermal stimuli. TRP channels with temperature sensitivity are called thermo-TRPs. They are involved in diverse physiological functions through their detection of external environmental temperature and internal body temperature. Each thermo-TRP has its own characteristic temperature threshold for activation. As a group, they cover temperatures ranging from cold to nociceptive high temperatures. Recently, many studies have identified the functions of thermo-TRPs residing in deep organs where they are exposed to body temperature. Importantly, temperature thresholds of thermo-TRPs can be regulated by physiological factors enabling their function at relatively constant body temperature. Moreover, several thermo-TRPs are reportedly engaged in body temperature regulation. This review will summarize the current understanding of thermo-TRPs, including their roles in thermosensation and functional regulation of physiological responses at body temperature and the regulation of body temperature.
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Affiliation(s)
- Makiko Kashio
- Department of Physiology, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan.
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53
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Ho HKY, Bigliardi PL, Stelmashenko O, Ramasamy S, Postlethwaite M, Bigliardi-Qi M. Functionally expressed bitter taste receptor TAS2R14 in human epidermal keratinocytes serves as a chemosensory receptor. Exp Dermatol 2021; 30:216-225. [PMID: 33253444 DOI: 10.1111/exd.14250] [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] [Received: 05/21/2020] [Revised: 10/30/2020] [Accepted: 11/23/2020] [Indexed: 01/23/2023]
Abstract
Traditionally, it is theorized that skin sensation is initiated when cutaneous sensory afferents and Merkel cells receive sensory stimuli, while epidermal keratinocytes were deemed to have no role. However, mounting evidence has shown that keratinocytes can initiate skin sensation by receiving sensory stimuli and transmitting sensory information to sensory afferents. Knowledge regarding the mechanisms by which keratinocytes receive exogenous stimuli is limited, with TRP channels and olfactory receptors having been proposed to serve as receptors for exogenous stimuli in keratinocytes. Recently, expression analyses have demonstrated the expression of multiple TAS2R genes in human skin. TAS2Rs are chemosensory GPCRs employed by taste cells to detect bitter-tasting substances. However, only subtypes TAS2R1 and TAS2R38 have been characterized in epidermal keratinocytes. We present evidence suggesting that subtype TAS2R14 is functionally expressed in epidermal keratinocytes. TAS2R14 transcripts and protein were detected in primary and N/TERT-1 keratinocytes. Additionally, keratinocytes responded to α-thujone, a TAS2R14 ligand, with an increase in intracellular free Ca2+ concentration. The tastant-evoked Ca2+ signals were found to be mediated by wild-type TAS2R14 and heterotrimeric G proteins. We conclude that TAS2R14 serves as a chemosensory receptor in epidermal keratinocytes and hypothesize that it enables the cells to recognize potentially harmful chemical substances.
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Affiliation(s)
- Hilary Kung-Yu Ho
- Agency for Science, Technology and Research, Institute of Medical Biology, Singapore, Singapore
| | - Paul Lorenz Bigliardi
- Department of Dermatology, University of Minnesota, Twin Cities, Minneapolis, MN, USA
| | - Olga Stelmashenko
- Agency for Science, Technology and Research, Institute of Medical Biology, Singapore, Singapore
| | - Srinivas Ramasamy
- Agency for Science, Technology and Research, Skin Research Institute Singapore, Singapore, Singapore
| | - Michael Postlethwaite
- Agency for Science, Technology and Research, Institute of Medical Biology, Singapore, Singapore
| | - Mei Bigliardi-Qi
- Department of Dermatology, University of Minnesota, Twin Cities, Minneapolis, MN, USA
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54
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Immune Regulatory Roles of Cells Expressing Taste Signaling Elements in Nongustatory Tissues. Handb Exp Pharmacol 2021; 275:271-293. [PMID: 33945029 DOI: 10.1007/164_2021_468] [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: 02/07/2023]
Abstract
G protein-coupled taste receptors and their downstream signaling elements, including Gnat3 (also known as α-gustducin) and TrpM5, were first identified in taste bud cells. Subsequent studies, however, revealed that some cells in nongustatory tissues also express taste receptors and/or their signaling elements. These nongustatory-tissue-expressed taste receptors and signaling elements play important roles in a number of physiological processes, including metabolism and immune responses. Special populations of cells expressing taste signaling elements in nongustatory tissues have been described as solitary chemosensory cells (SCCs) and tuft cells, mainly based on their morphological features and their expression of taste signaling elements as a critical molecular signature. These cells are typically scattered in barrier epithelial tissues, and their functions were largely unknown until recently. Emerging evidence shows that SCCs and tuft cells play important roles in immune responses to microbes and parasites. Additionally, certain immune cells also express taste receptors or taste signaling elements, suggesting a direct link between chemosensation and immune function. In this chapter, we highlight our current understanding of the functional roles of these "taste-like" cells and taste signaling pathways in different tissues, focusing on their activities in immune regulation.
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Abstract
All organisms have the ability to detect chemicals in the environment, which likely evolved out of organisms' needs to detect food sources and avoid potentially harmful compounds. The taste system detects chemicals and is used to determine whether potential food items will be ingested or rejected. The sense of taste detects five known taste qualities: bitter, sweet, salty, sour, and umami, which is the detection of amino acids, specifically glutamate. These different taste qualities encompass a wide variety of chemicals that differ in their structure and as a result, the peripheral taste utilizes numerous and diverse mechanisms to detect these stimuli. In this chapter, we will summarize what is currently known about the signaling mechanisms used by taste cells to transduce stimulus signals.
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Affiliation(s)
- Debarghya Dutta Banik
- Department of Biological Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY, USA
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kathryn F Medler
- Department of Biological Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY, USA.
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56
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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: 87] [Impact Index Per Article: 21.8] [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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Giuliani C, Franceschi C, Luiselli D, Garagnani P, Ulijaszek S. Ecological Sensing Through Taste and Chemosensation Mediates Inflammation: A Biological Anthropological Approach. Adv Nutr 2020; 11:1671-1685. [PMID: 32647890 PMCID: PMC7666896 DOI: 10.1093/advances/nmaa078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/24/2020] [Accepted: 06/11/2020] [Indexed: 12/19/2022] Open
Abstract
Ecological sensing and inflammation have evolved to ensure optima between organism survival and reproductive success in different and changing environments. At the molecular level, ecological sensing consists of many types of receptors located in different tissues that orchestrate integrated responses (immune, neuroendocrine systems) to external and internal stimuli. This review describes emerging data on taste and chemosensory receptors, proposing them as broad ecological sensors and providing evidence that taste perception is shaped not only according to sense epitopes from nutrients but also in response to highly diverse external and internal stimuli. We apply a biological anthropological approach to examine how ecological sensing has been shaped by these stimuli through human evolution for complex interkingdom communication between a host and pathological and symbiotic bacteria, focusing on population-specific genetic diversity. We then focus on how these sensory receptors play a major role in inflammatory processes that form the basis of many modern common metabolic diseases such as obesity, type 2 diabetes, and aging. The impacts of human niche construction and cultural evolution in shaping environments are described with emphasis on consequent biological responsiveness.
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Affiliation(s)
- Cristina Giuliani
- Department of Biological, Geological, and Environmental Sciences (BiGeA), Laboratory of Molecular Anthropology and Centre for Genome Biology, University of Bologna, Bologna, Italy
- School of Anthropology and Museum Ethnography, University of Oxford, Oxford, United Kingdom
- Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate), University of Bologna, Bologna, Italy
| | - Claudio Franceschi
- Laboratory of Systems Medicine of Healthy Aging and Department of Applied Mathematics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Donata Luiselli
- Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate), University of Bologna, Bologna, Italy
- Department of Cultural Heritage (DBC), Laboratory of Ancient DNA (aDNALab), Campus of Ravenna, University of Bologna, Bologna, Italy
| | - Paolo Garagnani
- Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate), University of Bologna, Bologna, Italy
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
- Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet at Huddinge University Hospital, Stockholm, Sweden
| | - Stanley Ulijaszek
- School of Anthropology and Museum Ethnography, University of Oxford, Oxford, United Kingdom
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58
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Behavioral Disassociation of Perceived Sweet Taste Intensity and Hedonically Positive Palatability. eNeuro 2020; 7:ENEURO.0268-20.2020. [PMID: 33077494 PMCID: PMC7598907 DOI: 10.1523/eneuro.0268-20.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/02/2020] [Accepted: 09/11/2020] [Indexed: 01/29/2023] Open
Abstract
The intensity of sucrose (its perceived concentration) and its palatability (positive hedonic valence associated with ingestion) are two taste attributes that increase its attractiveness and overconsumption. Although both sensory attributes covary, in that increases in sucrose concentration leads to similar increases in its palatability, this covariation does not imply that they are part of the same process or whether they represent separate processes. Both these possibilities are considered in the literature. For this reason, we tested whether sucrose’s perceived intensity could be separated from its hedonically positive palatability. To address this issue, rats were trained in a sucrose intensity task to report the perceived intensity of a range of sucrose concentrations before and after its palatability was changed using a conditioned taste aversion (CTA) protocol. We found that the subjects’ performance remained essentially unchanged, although its palatability was changed from hedonically positive to negative. Overall, these data demonstrate that sucrose’s perceived intensity and its positive palatability can be dissociated, meaning that changes of one taste attribute render the other mostly unaffected. Thus, the intensity attribute is sufficient to inform the perceptual judgments of sucrose’s concentrations.
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59
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Behavioral Disassociation of Perceived Sweet Taste Intensity and Hedonically Positive Palatability. eNeuro 2020. [PMID: 33077494 DOI: 10.1523/eneuro.0268‐20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The intensity of sucrose (its perceived concentration) and its palatability (positive hedonic valence associated with ingestion) are two taste attributes that increase its attractiveness and overconsumption. Although both sensory attributes covary, in that increases in sucrose concentration leads to similar increases in its palatability, this covariation does not imply that they are part of the same process or whether they represent separate processes. Both these possibilities are considered in the literature. For this reason, we tested whether sucrose's perceived intensity could be separated from its hedonically positive palatability. To address this issue, rats were trained in a sucrose intensity task to report the perceived intensity of a range of sucrose concentrations before and after its palatability was changed using a conditioned taste aversion (CTA) protocol. We found that the subjects' performance remained essentially unchanged, although its palatability was changed from hedonically positive to negative. Overall, these data demonstrate that sucrose's perceived intensity and its positive palatability can be dissociated, meaning that changes of one taste attribute render the other mostly unaffected. Thus, the intensity attribute is sufficient to inform the perceptual judgments of sucrose's concentrations.
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60
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An alternative pathway for sweet sensation: possible mechanisms and physiological relevance. Pflugers Arch 2020; 472:1667-1691. [PMID: 33030576 DOI: 10.1007/s00424-020-02467-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/14/2020] [Accepted: 09/23/2020] [Indexed: 12/12/2022]
Abstract
Sweet substances are detected by taste-bud cells upon binding to the sweet-taste receptor, a T1R2/T1R3 heterodimeric G protein-coupled receptor. In addition, experiments with mouse models lacking the sweet-taste receptor or its downstream signaling components led to the proposal of a parallel "alternative pathway" that may serve as metabolic sensor and energy regulator. Indeed, these mice showed residual nerve responses and behavioral attraction to sugars and oligosaccharides but not to artificial sweeteners. In analogy to pancreatic β cells, such alternative mechanism, to sense glucose in sweet-sensitive taste cells, might involve glucose transporters and KATP channels. Their activation may induce depolarization-dependent Ca2+ signals and release of GLP-1, which binds to its receptors on intragemmal nerve fibers. Via unknown neuronal and/or endocrine mechanisms, this pathway may contribute to both, behavioral attraction and/or induction of cephalic-phase insulin release upon oral sweet stimulation. Here, we critically review the evidence for a parallel sweet-sensitive pathway, involved signaling mechanisms, neural processing, interactions with endocrine hormonal mechanisms, and its sensitivity to different stimuli. Finally, we propose its physiological role in detecting the energy content of food and preparing for digestion.
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61
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Kang C, Wang L, Feng J, Zhu W, Hang S. l-Glutamate stimulates cholecystokinin secretion via the T1R1/T1R3 mediated PLC/TRPM5 transduction pathway. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:4818-4825. [PMID: 32478409 DOI: 10.1002/jsfa.10541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 05/17/2020] [Accepted: 06/01/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND It is known that cholecystokinin (CCK) plays an essential role in reducing food intake and driving weight loss. Previous studies demonstrated that amino acids were capable of triggering CCK release through G protein-coupled receptors, but the sensing mechanism remains obscure, especially the intracellular signaling pathway. RESULTS l-Glu, rather than its d-isomer, robustly stimulated CCK secretion in a porcine duodenal model, and the secretory response was augmented by incubation with the allosteric ligand of T1R1, while T1R3 antagonist attenuated it. Upon inhibiting phospholipase C (PLC) or transient receptor potential M5 (TRPM5) activity, l-Glu failed to increase CCK release. Oral administration of monosodium glutamate in rats also suppressed food intake and increased plasma CCK levels, accompanied by elevated expression of T1R1, PLCβ2 and TRPM5 in the duodenum. CONCLUSION These data demonstrated that l-Glu stimulated CCK secretion through the activation of T1R1/T1R3 in a PLC/TRPM5-dependent manner. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Cuicui Kang
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Lvyang Wang
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Jiangyin Feng
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Weiyun Zhu
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Suqin Hang
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
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62
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Taruno A, Nomura K, Kusakizako T, Ma Z, Nureki O, Foskett JK. Taste transduction and channel synapses in taste buds. Pflugers Arch 2020; 473:3-13. [PMID: 32936320 DOI: 10.1007/s00424-020-02464-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 07/29/2020] [Accepted: 09/07/2020] [Indexed: 12/31/2022]
Abstract
The variety of taste sensations, including sweet, umami, bitter, sour, and salty, arises from diverse taste cells, each of which expresses specific taste sensor molecules and associated components for downstream signal transduction cascades. Recent years have witnessed major advances in our understanding of the molecular mechanisms underlying transduction of basic tastes in taste buds, including the identification of the bona fide sour sensor H+ channel OTOP1, and elucidation of transduction of the amiloride-sensitive component of salty taste (the taste of sodium) and the TAS1R-independent component of sweet taste (the taste of sugar). Studies have also discovered an unconventional chemical synapse termed "channel synapse" which employs an action potential-activated CALHM1/3 ion channel instead of exocytosis of synaptic vesicles as the conduit for neurotransmitter release that links taste cells to afferent neurons. New images of the channel synapse and determinations of the structures of CALHM channels have provided structural and functional insights into this unique synapse. In this review, we discuss the current view of taste transduction and neurotransmission with emphasis on recent advances in the field.
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Affiliation(s)
- Akiyuki Taruno
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. .,Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama, Japan.
| | - Kengo Nomura
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Zhongming Ma
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - J Kevin Foskett
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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63
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Gutierrez R, Fonseca E, Simon SA. The neuroscience of sugars in taste, gut-reward, feeding circuits, and obesity. Cell Mol Life Sci 2020; 77:3469-3502. [PMID: 32006052 PMCID: PMC11105013 DOI: 10.1007/s00018-020-03458-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/06/2020] [Accepted: 01/10/2020] [Indexed: 12/19/2022]
Abstract
Throughout the animal kingdom sucrose is one of the most palatable and preferred tastants. From an evolutionary perspective, this is not surprising as it is a primary source of energy. However, its overconsumption can result in obesity and an associated cornucopia of maladies, including type 2 diabetes and cardiovascular disease. Here we describe three physiological levels of processing sucrose that are involved in the decision to ingest it: the tongue, gut, and brain. The first section describes the peripheral cellular and molecular mechanisms of sweet taste identification that project to higher brain centers. We argue that stimulation of the tongue with sucrose triggers the formation of three distinct pathways that convey sensory attributes about its quality, palatability, and intensity that results in a perception of sweet taste. We also discuss the coding of sucrose throughout the gustatory pathway. The second section reviews how sucrose, and other palatable foods, interact with the gut-brain axis either through the hepatoportal system and/or vagal pathways in a manner that encodes both the rewarding and of nutritional value of foods. The third section reviews the homeostatic, hedonic, and aversive brain circuits involved in the control of food intake. Finally, we discuss evidence that overconsumption of sugars (or high fat diets) blunts taste perception, the post-ingestive nutritional reward value, and the circuits that control feeding in a manner that can lead to the development of obesity.
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Affiliation(s)
- Ranier Gutierrez
- Laboratory of Neurobiology of Appetite, Department of Pharmacology, CINVESTAV, 07360, Mexico City, Mexico.
| | - Esmeralda Fonseca
- Laboratory of Neurobiology of Appetite, Department of Pharmacology, CINVESTAV, 07360, Mexico City, Mexico
| | - Sidney A Simon
- Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA
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Aroke EN, Powell-Roach KL, Jaime-Lara RB, Tesfaye M, Roy A, Jackson P, Joseph PV. Taste the Pain: The Role of TRP Channels in Pain and Taste Perception. Int J Mol Sci 2020; 21:E5929. [PMID: 32824721 PMCID: PMC7460556 DOI: 10.3390/ijms21165929] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/12/2020] [Accepted: 08/16/2020] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential (TRP) channels are a superfamily of cation transmembrane proteins that are expressed in many tissues and respond to many sensory stimuli. TRP channels play a role in sensory signaling for taste, thermosensation, mechanosensation, and nociception. Activation of TRP channels (e.g., TRPM5) in taste receptors by food/chemicals (e.g., capsaicin) is essential in the acquisition of nutrients, which fuel metabolism, growth, and development. Pain signals from these nociceptors are essential for harm avoidance. Dysfunctional TRP channels have been associated with neuropathic pain, inflammation, and reduced ability to detect taste stimuli. Humans have long recognized the relationship between taste and pain. However, the mechanisms and relationship among these taste-pain sensorial experiences are not fully understood. This article provides a narrative review of literature examining the role of TRP channels on taste and pain perception. Genomic variability in the TRPV1 gene has been associated with alterations in various pain conditions. Moreover, polymorphisms of the TRPV1 gene have been associated with alterations in salty taste sensitivity and salt preference. Studies of genetic variations in TRP genes or modulation of TRP pathways may increase our understanding of the shared biological mediators of pain and taste, leading to therapeutic interventions to treat many diseases.
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Affiliation(s)
- Edwin N. Aroke
- School of Nursing, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (E.N.A.); (P.J.)
| | | | - Rosario B. Jaime-Lara
- Sensory Science and Metabolism Unit (SenSMet), National Institute of Nursing Research, National Institutes of Health, Bethesda, MD 20892, USA; (R.B.J.-L.); (M.T.); (A.R.)
| | - Markos Tesfaye
- Sensory Science and Metabolism Unit (SenSMet), National Institute of Nursing Research, National Institutes of Health, Bethesda, MD 20892, USA; (R.B.J.-L.); (M.T.); (A.R.)
| | - Abhrabrup Roy
- Sensory Science and Metabolism Unit (SenSMet), National Institute of Nursing Research, National Institutes of Health, Bethesda, MD 20892, USA; (R.B.J.-L.); (M.T.); (A.R.)
| | - Pamela Jackson
- School of Nursing, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (E.N.A.); (P.J.)
| | - Paule V. Joseph
- Sensory Science and Metabolism Unit (SenSMet), National Institute of Nursing Research, National Institutes of Health, Bethesda, MD 20892, USA; (R.B.J.-L.); (M.T.); (A.R.)
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65
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Dutta Banik D, Benfey ED, Martin LE, Kay KE, Loney GC, Nelson AR, Ahart ZC, Kemp BT, Kemp BR, Torregrossa AM, Medler KF. A subset of broadly responsive Type III taste cells contribute to the detection of bitter, sweet and umami stimuli. PLoS Genet 2020; 16:e1008925. [PMID: 32790785 PMCID: PMC7425866 DOI: 10.1371/journal.pgen.1008925] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 06/10/2020] [Indexed: 12/20/2022] Open
Abstract
Taste receptor cells use multiple signaling pathways to detect chemicals in potential food items. These cells are functionally grouped into different types: Type I cells act as support cells and have glial-like properties; Type II cells detect bitter, sweet, and umami taste stimuli; and Type III cells detect sour and salty stimuli. We have identified a new population of taste cells that are broadly tuned to multiple taste stimuli including bitter, sweet, sour, and umami. The goal of this study was to characterize these broadly responsive (BR) taste cells. We used an IP3R3-KO mouse (does not release calcium (Ca2+) from internal stores in Type II cells when stimulated with bitter, sweet, or umami stimuli) to characterize the BR cells without any potentially confounding input from Type II cells. Using live cell Ca2+ imaging in isolated taste cells from the IP3R3-KO mouse, we found that BR cells are a subset of Type III cells that respond to sour stimuli but also use a PLCβ signaling pathway to respond to bitter, sweet, and umami stimuli. Unlike Type II cells, individual BR cells are broadly tuned and respond to multiple stimuli across different taste modalities. Live cell imaging in a PLCβ3-KO mouse confirmed that BR cells use this signaling pathway to respond to bitter, sweet, and umami stimuli. Short term behavioral assays revealed that BR cells make significant contributions to taste driven behaviors and found that loss of either PLCβ3 in BR cells or IP3R3 in Type II cells caused similar behavioral deficits to bitter, sweet, and umami stimuli. Analysis of c-Fos activity in the nucleus of the solitary tract (NTS) also demonstrated that functional Type II and BR cells are required for normal stimulus induced expression. We use our taste system to decide if we are going to consume or reject a potential food item. This is critical for survival, as we need energy to live but also need to avoid potentially toxic compounds. Therefore, it is important to understand how the taste cells in our mouth detect the chemicals in food and send a message to our brain. Signals from the taste cells form a code that conveys information about the nature of the potential food item to the brain. How this taste coding works is not well understood. Currently, it is thought that taste cells are primarily selective for each taste stimuli and only detect either bitter, sweet, sour, salt, or umami (amino acids) compounds. Our study describes a new population of taste cells that can detect multiple types of stimuli, including chemicals from different taste qualities. Thus, taste cells can be either selective or generally responsive to stimuli which is similar to the cells in the brain that process taste information. The presence of these broadly responsive taste cells provides new insight into how taste information is sent to the brain for processing.
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Affiliation(s)
- Debarghya Dutta Banik
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Eric D. Benfey
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Laura E. Martin
- Department of Psychology, University at Buffalo, Buffalo, New York, United States of America
| | - Kristen E. Kay
- Department of Psychology, University at Buffalo, Buffalo, New York, United States of America
| | - Gregory C. Loney
- Department of Psychology, University at Buffalo, Buffalo, New York, United States of America
| | - Amy R. Nelson
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Zachary C. Ahart
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Barrett T. Kemp
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Bailey R. Kemp
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Ann-Marie Torregrossa
- Department of Psychology, University at Buffalo, Buffalo, New York, United States of America
- Center for Ingestive Behavior Research, University at Buffalo, Buffalo, New York, United States of America
| | - Kathryn F. Medler
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
- Center for Ingestive Behavior Research, University at Buffalo, Buffalo, New York, United States of America
- * E-mail:
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A Family of Auxiliary Subunits of the TRP Cation Channel Encoded by the Complex inaF Locus. Genetics 2020; 215:713-728. [PMID: 32434796 DOI: 10.1534/genetics.120.303268] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 05/15/2020] [Indexed: 02/06/2023] Open
Abstract
TRP channels function in many types of sensory receptor cells. Despite extensive analyses, an open question is whether there exists a family of auxiliary subunits, which could influence localization, trafficking, and function of TRP channels. Here, using Drosophila melanogaster, we reveal a previously unknown TRP interacting protein, INAF-C, which is expressed exclusively in the ultraviolet-sensing R7 photoreceptor cells. INAF-C is encoded by an unusual locus comprised of four distinct coding regions, which give rise to four unique single-transmembrane-containing proteins. With the exception of INAF-B, roles for the other INAF proteins were unknown. We found that both INAF-B and INAF-C are required for TRP stability and localization in R7 cells. Conversely, loss of just INAF-B greatly reduced TRP from other types of photoreceptor cells, but not R7. The requirements for TRP and INAF are reciprocal, since loss of TRP decreased the concentrations of both INAF-B and INAF-C. INAF-A, which is not normally expressed in photoreceptor cells, can functionally substitute for INAF-B, indicating that it is a third TRP auxiliary protein. Reminiscent of the structural requirements between Kv channels and KCNE auxiliary subunits, the codependencies of TRP and INAF depended on several transmembrane domains (TMDs) in TRP, and the TMD and the C-terminus of INAF-B. Our studies support a model in which the inaF locus encodes a family of at least three TRP auxiliary subunits.
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Sclafani A, Zukerman S, Ackroff K. Residual Glucose Taste in T1R3 Knockout but not TRPM5 Knockout Mice. Physiol Behav 2020; 222:112945. [PMID: 32417232 DOI: 10.1016/j.physbeh.2020.112945] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 12/19/2022]
Abstract
Knockout (KO) mice missing the sweet taste receptor subunit T1R3 or the signaling protein TRPM5 have greatly attenuated sweetener preferences. Yet both types of KO mice develop preferences for glucose but not fructose in 24-h tests, which has been attributed to the postoral reinforcing actions of glucose. Here we probed for residual sugar taste sensitivity in KO mice. Unlike wildtype (WT) mice, food-restricted T1R3 KO and TRPM5 KO mice displayed little attraction for 8% glucose and 8% fructose in 1-min, two-bottle choice tests. However, in 1-h tests about half of the T1R3 KO mice displayed a significant preference for glucose over fructose (78-84%), while WT mice showed either no or weak preferences (41-56%) for glucose. Following one-bottle training sessions, WT mice display greater glucose preferences although still weaker than those observed in T1R3 KO mice. In contrast, TRPM5 KO mice were indifferent to sugars in 1-h tests but developed a strong preference for glucose over fructose in 24-h tests. T1R3 taste cells contain the sodium glucose cotransporter 1 (SGLT1) and the ATP-gated K+ (KATP) metabolic sensor, which may mediate the unlearned glucose preference displayed by T1R3 KO mice. Unlike WT mice, many T1R3 KO mice strongly preferred glucose to a non-metabolizable glucose analog (α-methyl-D-glucopyranoside, MDG) in initial 1-h choice tests. Glucose and MDG are both ligands for SGLT1 which indicates that SGLT1 sensing does not mediate the glucose preference of T1R3 KO mice. Instead, KATP sensing and/or other oral sensors are implicated. The MDG findings also argue against postoral sensing as the primary source of the initial glucose preference displayed by T1R3 KO mice. Why only half of the T1R3 KO mice showed this preference in 1-h tests remains to be determined. All T1R3 KO mice preferred glucose to fructose in 24-h tests, which appears to be due to both oral and postoral glucose sensing.
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Affiliation(s)
- Anthony Sclafani
- Department of Psychology, Brooklyn College of City University of New York, Brooklyn, New York 11210, USA.
| | - Steven Zukerman
- Department of Psychology, Brooklyn College of City University of New York, Brooklyn, New York 11210, USA
| | - Karen Ackroff
- Department of Psychology, Brooklyn College of City University of New York, Brooklyn, New York 11210, USA
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68
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Bloxham CJ, Foster SR, Thomas WG. A Bitter Taste in Your Heart. Front Physiol 2020; 11:431. [PMID: 32457649 PMCID: PMC7225360 DOI: 10.3389/fphys.2020.00431] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/08/2020] [Indexed: 12/11/2022] Open
Abstract
The human genome contains ∼29 bitter taste receptors (T2Rs), which are responsible for detecting thousands of bitter ligands, including toxic and aversive compounds. This sentinel function varies between individuals and is underpinned by naturally occurring T2R polymorphisms, which have also been associated with disease. Recent studies have reported the expression of T2Rs and their downstream signaling components within non-gustatory tissues, including the heart. Though the precise role of T2Rs in the heart remains unclear, evidence points toward a role in cardiac contractility and overall vascular tone. In this review, we summarize the extra-oral expression of T2Rs, focusing on evidence for expression in heart; we speculate on the range of potential ligands that may activate them; we define the possible signaling pathways they activate; and we argue that their discovery in heart predicts an, as yet, unappreciated cardiac physiology.
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Affiliation(s)
- Conor J Bloxham
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, Australia
| | - Simon R Foster
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Walter G Thomas
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, Australia
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69
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Eckstein E, Pyrski M, Pinto S, Freichel M, Vennekens R, Zufall F. Cyclic regulation of Trpm4 expression in female vomeronasal neurons driven by ovarian sex hormones. Mol Cell Neurosci 2020; 105:103495. [PMID: 32298804 DOI: 10.1016/j.mcn.2020.103495] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/13/2020] [Accepted: 04/11/2020] [Indexed: 01/29/2023] Open
Abstract
The vomeronasal organ (VNO), the sensory organ of the mammalian accessory olfactory system, mediates the activation of sexually dimorphic reproductive behavioral and endocrine responses in males and females. It is unclear how sexually dimorphic and state-dependent responses are generated by vomeronasal sensory neurons (VSNs). Here, we report the expression of the transient receptor potential (TRP) channel Trpm4, a Ca2+-activated monovalent cation channel, as a second TRP channel present in mouse VSNs, in addition to the diacylglycerol-sensitive Trpc2 channel. The expression of Trpm4 in the mouse VNO is sexually dimorphic and, in females, is tightly linked to their reproductive cycle. We show that Trpm4 protein expression is upregulated specifically during proestrus and estrus, when female mice are about to ovulate and become sexually active and receptive. The cyclic regulation of Trpm4 expression in female VSNs depends on ovarian sex hormones and is abolished by surgical removal of the ovaries (OVX). Trpm4 upregulation can be restored in OVX mice by systemic treatment with 17ß-estradiol, requires endogenous activity of aromatase enzyme, and is strongly reduced during late pregnancy. This cyclic regulation of Trpm4 offers a neural mechanism by which female mice could regulate the relative strength of sensory signals in their VSNs, depending on hormonal state. Trpm4 is likely to participate in sex-specific, estrous cycle-dependent and sex hormone-regulated functions of the VNO, and may serve as a previously unknown genetic substrate for dissecting mammalian sexually dimorphic cellular and behavioral responses.
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Affiliation(s)
- Eugenia Eckstein
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Martina Pyrski
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Silvia Pinto
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Marc Freichel
- Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Rudi Vennekens
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Frank Zufall
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany.
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70
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Leung NY, Thakur DP, Gurav AS, Kim SH, Di Pizio A, Niv MY, Montell C. Functions of Opsins in Drosophila Taste. Curr Biol 2020; 30:1367-1379.e6. [PMID: 32243853 DOI: 10.1016/j.cub.2020.01.068] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/16/2020] [Accepted: 01/22/2020] [Indexed: 12/31/2022]
Abstract
Rhodopsin is a light receptor comprised of an opsin protein and a light-sensitive retinal chromophore. Despite more than a century of scrutiny, there is no evidence that opsins function in chemosensation. Here, we demonstrate that three Drosophila opsins, Rh1, Rh4, and Rh7, are needed in gustatory receptor neurons to sense a plant-derived bitter compound, aristolochic acid (ARI). The gustatory requirements for these opsins are light-independent and do not require retinal. The opsins enabled flies to detect lower concentrations of aristolochic acid by initiating an amplification cascade that includes a G-protein, phospholipase Cβ, and the TRP channel, TRPA1. In contrast, responses to higher levels of the bitter compound were mediated through direct activation of TRPA1. Our study reveals roles for opsins in chemosensation and raise questions concerning the original roles for these classical G-protein-coupled receptors.
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Affiliation(s)
- Nicole Y Leung
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Dhananjay P Thakur
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Adishthi S Gurav
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Sang Hoon Kim
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Antonella Di Pizio
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel; The Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; Leibniz-Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Masha Y Niv
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel; The Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Craig Montell
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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71
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Sensing Senses: Optical Biosensors to Study Gustation. SENSORS 2020; 20:s20071811. [PMID: 32218129 PMCID: PMC7180777 DOI: 10.3390/s20071811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/19/2020] [Accepted: 03/21/2020] [Indexed: 12/11/2022]
Abstract
The five basic taste modalities, sweet, bitter, umami, salty and sour induce changes of Ca2+ levels, pH and/or membrane potential in taste cells of the tongue and/or in neurons that convey and decode gustatory signals to the brain. Optical biosensors, which can be either synthetic dyes or genetically encoded proteins whose fluorescence spectra depend on levels of Ca2+, pH or membrane potential, have been used in primary cells/tissues or in recombinant systems to study taste-related intra- and intercellular signaling mechanisms or to discover new ligands. Taste-evoked responses were measured by microscopy achieving high spatial and temporal resolution, while plate readers were employed for higher throughput screening. Here, these approaches making use of fluorescent optical biosensors to investigate specific taste-related questions or to screen new agonists/antagonists for the different taste modalities were reviewed systematically. Furthermore, in the context of recent developments in genetically encoded sensors, 3D cultures and imaging technologies, we propose new feasible approaches for studying taste physiology and for compound screening.
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72
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Ahart ZC, Martin LE, Kemp BR, Banik DD, Roberts SG, Torregrossa AM, Medler KF. Differential Effects of Diet and Weight on Taste Responses in Diet-Induced Obese Mice. Obesity (Silver Spring) 2020; 28:284-292. [PMID: 31891242 PMCID: PMC6981059 DOI: 10.1002/oby.22684] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 09/21/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Previous studies have reported that individuals with obesity have reduced taste perception, but the relationship between obesity and taste is poorly understood. Earlier work has demonstrated that diet-induced obesity directly impairs taste. Currently, it is not clear whether these changes to taste are due to obesity or to the high-fat diet exposure. The goal of the current study was to determine whether diet or excess weight is responsible for the taste deficits induced by diet-induced obesity. METHODS C57BL/6 mice were placed on either high-fat or standard chow in the presence or absence of captopril. Mice on captopril did not gain weight when exposed to a high-fat diet. Changes in the responses to different taste stimuli were evaluated using live cell imaging, brief-access licking, immunohistochemistry, and real-time polymerase chain reaction. RESULTS Diet and weight gain each affected taste responses, but their effects varied by stimulus. Two key signaling proteins, α-gustducin and phospholipase Cβ2, were significantly reduced in the mice on the high-fat diet with and without weight gain, identifying a potential mechanism for the reduced taste responsiveness to some stimuli. CONCLUSIONS Our data indicate that, for some stimuli, diet alone can cause taste deficits, even without the onset of obesity.
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Affiliation(s)
- Zachary C. Ahart
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Laura E. Martin
- Department of Psychology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Bailey R. Kemp
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Debarghya Dutta Banik
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Stefan G.E. Roberts
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA
- School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK
| | - Ann-Marie Torregrossa
- Department of Psychology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Kathryn F Medler
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA
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von Molitor E, Nürnberg E, Ertongur-Fauth T, Scholz P, Riedel K, Hafner M, Rudolf R, Cesetti T. Analysis of calcium signaling in live human Tongue cell 3D-Cultures upon tastant perfusion. Cell Calcium 2020; 87:102164. [PMID: 32014795 DOI: 10.1016/j.ceca.2020.102164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/29/2019] [Accepted: 01/16/2020] [Indexed: 02/06/2023]
Abstract
Bridging the gap between two-dimensional cell cultures and complex in vivo tissues, three-dimensional cell culture models are of increasing interest in the fields of cell biology and pharmacology. However, present challenges hamper live cell imaging of three-dimensional cell cultures. These include (i) the stabilization of these structures under perfusion conditions, (ii) the recording of many z-planes at high spatio-temporal resolution, (iii) and the data analysis that ranges in complexity from whole specimens to single cells. Here, we addressed these issues for the time-lapse analysis of Ca2+ signaling in spheroids composed of human tongue-derived HTC-8 cells upon perfusion of gustatory substances. Live cell imaging setups for confocal and light sheet microscopy were developed that allow simple and robust spheroid stabilization and high-resolution microscopy with perfusion. Visualization of spheroids made of HTC-8 cells expressing the G-GECO fluorescent Ca2+ sensor revealed Ca2+ transients that showed similar kinetics but different amplitudes upon perfusion of bitter compounds Salicine and Saccharin. Dose-dependent responses to Saccharin required extracellular Ca2+. From the border towards the center of spheroids, compound-induced Ca2+ signals were progressively delayed and decreased in amplitude. Stimulation with ATP led to strong Ca2+ transients that were faster than those evoked by the bitter compounds and blockade of purinergic receptors with Suramin abutted the response to Saccharin, suggesting that ATP mediates a positive autocrine and paracrine feedback. Imaging of ATP-induced Ca2+ transients with light sheet microscopy allowed acquisition over a z-depth of 100 μm without losing spatial and temporal resolution. In summary, the presented approaches permit the study of fast cellular signaling in three-dimensional cultures upon compound perfusion.
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Affiliation(s)
- Elena von Molitor
- Institute of Molecular and Cell Biology, Hochschule Mannheim, 68163 Mannheim, Germany
| | - Elina Nürnberg
- Institute of Molecular and Cell Biology, Hochschule Mannheim, 68163 Mannheim, Germany
| | | | | | | | - Mathias Hafner
- Institute of Molecular and Cell Biology, Hochschule Mannheim, 68163 Mannheim, Germany.
| | - Rüdiger Rudolf
- Institute of Molecular and Cell Biology, Hochschule Mannheim, 68163 Mannheim, Germany; Interdisciplinary Center for Neurosciences, Heidelberg University, 69120 Heidelberg, Germany.
| | - Tiziana Cesetti
- Institute of Molecular and Cell Biology, Hochschule Mannheim, 68163 Mannheim, Germany
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Governini L, Semplici B, Pavone V, Crifasi L, Marrocco C, De Leo V, Arlt E, Gudermann T, Boekhoff I, Luddi A, Piomboni P. Expression of Taste Receptor 2 Subtypes in Human Testis and Sperm. J Clin Med 2020; 9:E264. [PMID: 31963712 PMCID: PMC7019805 DOI: 10.3390/jcm9010264] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 12/31/2022] Open
Abstract
Taste receptors (TASRs) are expressed not only in the oral cavity but also throughout the body, thus suggesting that they may play different roles in organ systems beyond the tongue. Recent studies showed the expression of several TASRs in mammalian testis and sperm, indicating an involvement of these receptors in male gametogenesis and fertility. This notion is supported by an impaired reproductive phenotype of mouse carrying targeted deletion of taste receptor genes, as well as by a significant correlation between human semen parameters and specific polymorphisms of taste receptor genes. To better understand the biological and thus clinical significance of these receptors for human reproduction, we analyzed the expression of several members of the TAS2Rs family of bitter receptors in human testis and in ejaculated sperm before and after in vitro selection and capacitation. Our results provide evidence for the expression of TAS2R genes, with TAS2R14 being the most expressed bitter receptor subtype in both testis tissue and sperm cells, respectively. In addition, it was observed that in vitro capacitation significantly affects both the expression and the subcellular localization of these receptors in isolated spermatozoa. Interestingly, α-gustducin and α-transducin, two Gα subunits expressed in taste buds on the tongue, are also expressed in human spermatozoa; moreover, a subcellular redistribution of both G protein α-subunits to different sub-compartments of sperm was registered upon in vitro capacitation. Finally, we shed light on the possible downstream transduction pathway initiated upon taste receptor activation in the male reproductive system. Performing ultrasensitive droplets digital PCR assays to quantify RNA copy numbers of a distinct gene, we found a significant correlation between the expression of TAS2Rs and TRPM5 (r = 0.87), the cation channel involved in bitter but also sweet and umami taste transduction in taste buds on the tongue. Even if further studies are needed to clarify the precise functional role of taste receptors for successful reproduction, the presented findings significantly extend our knowledge of the biological role of TAS2Rs for human male fertility.
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Affiliation(s)
- Laura Governini
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Bianca Semplici
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Valentina Pavone
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Laura Crifasi
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Camilla Marrocco
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Vincenzo De Leo
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Elisabeth Arlt
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80336 Muenchen, Germany; (E.A.); (T.G.); (I.B.)
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80336 Muenchen, Germany; (E.A.); (T.G.); (I.B.)
| | - Ingrid Boekhoff
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80336 Muenchen, Germany; (E.A.); (T.G.); (I.B.)
| | - Alice Luddi
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
| | - Paola Piomboni
- Department of Molecular and Developmental Medicine, Siena University, 53100 Siena, Italy; (L.G.); (B.S.); (V.P.); (L.C.); (C.M.); (V.D.L.); (P.P.)
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Abstract
In the last few years, single-cell profiling of taste cells and ganglion cells has advanced our understanding of transduction, encoding, and transmission of information from taste buds as relayed to the central nervous system. This review focuses on new knowledge from these molecular approaches and attempts to place this in the context of previous questions and findings in the field. The individual taste cells within a taste bud are molecularly specialized for detection of one of the primary taste qualities: salt, sour, sweet, umami, and bitter. Transduction and transmitter release mechanisms differ substantially for taste cells transducing sour (Type III cells) compared with those transducing the qualities of sweet, umami, or bitter (Type II cells), although ultimately all transmission of taste relies on activation of purinergic P2X receptors on the afferent nerves. The ganglion cells providing innervation to the taste buds also appear divisible into functional and molecular subtypes, and each ganglion cell is primarily but not exclusively responsive to one taste quality.
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Affiliation(s)
- Sue C. Kinnamon
- Rocky Mountain Taste & Smell Center, Department of Otolaryngology and Department of Cell & Developmental Biology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Thomas E. Finger
- Rocky Mountain Taste & Smell Center, Department of Otolaryngology and Department of Cell & Developmental Biology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
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Wong KK, Banham AH, Yaacob NS, Nur Husna SM. The oncogenic roles of TRPM ion channels in cancer. J Cell Physiol 2019; 234:14556-14573. [PMID: 30710353 DOI: 10.1002/jcp.28168] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/10/2019] [Indexed: 01/24/2023]
Abstract
Transient receptor potential (TRP) proteins are a diverse family of ion channels present in multiple types of tissues. They function as gatekeepers for responses to sensory stimuli including temperature, vision, taste, and pain through their activities in conducting ion fluxes. The TRPM (melastatin) subfamily consists of eight members (i.e., TRPM1-8), which collectively regulate fluxes of various types of cations such as K+ , Na+ , Ca2+ , and Mg2+ . Growing evidence in the past two decades indicates that TRPM ion channels, their isoforms, or long noncoding RNAs encoded within the locus may be oncogenes involved in the regulation of cancer cell growth, proliferation, autophagy, invasion, and epithelial-mesenchymal transition, and their significant association with poor clinical outcomes of cancer patients. In this review, we describe and discuss recent findings implicating TRPM channels in different malignancies, their functions, mechanisms, and signaling pathways involved in cancers, as well as summarizing their normal physiological functions and the availability of ion channel pharmacological inhibitors.
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Affiliation(s)
- Kah Keng Wong
- Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Alison H Banham
- Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Nik Soriani Yaacob
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, Kubang Kerian, Kelantan, Malaysia
| | - Siti Muhamad Nur Husna
- Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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77
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Cui Y, Wu H, Li Q, Liao J, Gao P, Sun F, Zhang H, Lu Z, Wei X, He C, Ma T, Wei X, Chen X, Zheng H, Yang G, Liu D, Zhu Z. Impairment of Bitter Taste Sensor Transient Receptor Potential Channel M5-Mediated Aversion Aggravates High-Salt Intake and Hypertension. Hypertension 2019; 74:1021-1032. [PMID: 31401881 DOI: 10.1161/hypertensionaha.119.13358] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Excessive salt consumption leads to cardiovascular diseases. Despite various measures designed to reduce salt intake, daily salt intake remains at a high level. Appropriate salt intake is balanced by salt taste preference triggered by epithelium sodium channel and salt taste aversion evoked by bitter taste sensor, transient receptor potential channel M5 (TRPM5). However, the behavioral mechanism of excessive salt intake remains largely elusive. In this study, wild type and TRPM5-/- mice were applied to study the influence of high-salt administration on epithelium sodium channel/TRPM5 and the associated behavior to salt consumption. We found that long-term high-salt intake impaired the aversive behavior to high-salt stimulation but did not alter the preference to low salt in mice. The mechanistic evidence demonstrated that high-salt intake blunted the TRPM5-mediated aversive behavior to noxious salt stimulation through inhibiting PKC (protein kinase C) activity and PKC-dependent threonine phosphorylation in the tongue epithelium but did not affect the epithelium sodium channel-dependent salt taste preference. Inhibition of TRPM5 also resulted in an impaired aversive response to high salt, with reduced taste perception in bitter cortical field of mice. TRPM5-/- mice showed a lowered aversion to high-salt diet and developed salt-induced hypertension. The impaired perception to bitter taste evoked by high-salt intake also existed in hypertensive patients with high-salt consumption. We demonstrate that long-term high-salt consumption impairs aversive response to concentrated salt by downregulating bitter taste sensor TRPM5. It suggests that enhancing TRPM5 function might antagonize excessive salt intake and high salt-induced hypertension.
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Affiliation(s)
- Yuanting Cui
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Hao Wu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Qiang Li
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Jianwen Liao
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Peng Gao
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Fang Sun
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Hexuan Zhang
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Zongshi Lu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Xiao Wei
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Chengkang He
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Tianyi Ma
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Xing Wei
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Xiaowei Chen
- Brain Research Center (X.C.), Third Military Medical University, China
| | - Hongting Zheng
- Department of Endocrinology, Translational Research Key Laboratory for Diabetes, Xinqiao Hospital (H.Z.), Third Military Medical University, China
| | - Gangyi Yang
- Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, China (G.Y.)
| | - Daoyan Liu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
| | - Zhiming Zhu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Chongqing Institute of Hypertension (Y.C., H.W., Q.L., J.L., P.G., F.S., H.Z., Z.L., X.W., C.H., T.M., X.W., D.L., Z.Z.), Third Military Medical University, China
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78
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Lasconi C, Pifferi S, Hernandez-Clavijo A, Merigo F, Cecchini MP, Gonzalez-Velandia KY, Agostinelli E, Sbarbati A, Menini A. Bitter tastants and artificial sweeteners activate a subset of epithelial cells in acute tissue slices of the rat trachea. Sci Rep 2019; 9:8834. [PMID: 31222082 PMCID: PMC6586933 DOI: 10.1038/s41598-019-45456-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Bitter and sweet receptors (T2Rs and T1Rs) are expressed in many extra-oral tissues including upper and lower airways. To investigate if bitter tastants and artificial sweeteners could activate physiological responses in tracheal epithelial cells we performed confocal Ca2+ imaging recordings on acute tracheal slices. We stimulated the cells with denatonium benzoate, a T2R agonist, and with the artificial sweeteners sucralose, saccharin and acesulfame-K. To test cell viability we measured responses to ATP. We found that 39% of the epithelial cells responding to ATP also responded to bitter stimulation with denatonium benzoate. Moreover, artificial sweeteners activated different percentages of the cells, ranging from 5% for sucralose to 26% for saccharin, and 27% for acesulfame-K. By using carbenoxolone, a gap junction blocker, we excluded that responses were mainly mediated by Ca2+ waves through cell-to-cell junctions. Pharmacological experiments showed that both denatonium and artificial sweeteners induced a PLC-mediated release of Ca2+ from internal stores. In addition, bitter tastants and artificial sweeteners activated a partially overlapping subpopulation of tracheal epithelial cells. Our results provide new evidence that a subset of ATP-responsive tracheal epithelial cells from rat are activated by both bitter tastants and artificial sweeteners.
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Affiliation(s)
- Chiara Lasconi
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona, School of Medicine, Verona, Italy
| | - Simone Pifferi
- Neurobiology Group, SISSA, International School for Advanced Studies, Trieste, Italy.
| | | | - Flavia Merigo
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona, School of Medicine, Verona, Italy
| | - Maria Paola Cecchini
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona, School of Medicine, Verona, Italy.
| | | | - Emilio Agostinelli
- Neurobiology Group, SISSA, International School for Advanced Studies, Trieste, Italy
| | - Andrea Sbarbati
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona, School of Medicine, Verona, Italy
| | - Anna Menini
- Neurobiology Group, SISSA, International School for Advanced Studies, Trieste, Italy
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79
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Gao Y, Dutta Banik D, Muna MM, Roberts SG, Medler KF. The WT1-BASP1 complex is required to maintain the differentiated state of taste receptor cells. Life Sci Alliance 2019; 2:2/3/e201800287. [PMID: 31167803 PMCID: PMC6555901 DOI: 10.26508/lsa.201800287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/27/2019] [Accepted: 05/27/2019] [Indexed: 12/21/2022] Open
Abstract
The WT1/BASP1 complex is important to maintain taste receptor cells in their terminally differentiated state. WT1 is a transcriptional activator that controls the boundary between multipotency and differentiation. The transcriptional cofactor BASP1 binds to WT1, forming a transcriptional repressor complex that drives differentiation in cultured cells; however, this proposed mechanism has not been demonstrated in vivo. We used the peripheral taste system as a model to determine how BASP1 regulates the function of WT1. During development, WT1 is highly expressed in the developing taste cells while BASP1 is absent. By the end of development, BASP1 and WT1 are co-expressed in taste cells, where they both occupy the promoter of WT1 target genes. Using a conditional BASP1 mouse, we demonstrate that BASP1 is critical to maintain the differentiated state of adult taste cells and that loss of BASP1 expression significantly alters the composition and function of these cells. This includes the de-repression of WT1-dependent target genes from the Wnt and Shh pathways that are normally only transcriptionally activated by WT1 in the undifferentiated taste cells. Our results uncover a central role for the WT1–BASP1 complex in maintaining cell differentiation in vivo.
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Affiliation(s)
- Yankun Gao
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
| | | | - Mutia M Muna
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
| | - Stefan Ge Roberts
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA .,School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Kathryn F Medler
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
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80
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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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81
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Schier LA, Spector AC. The Functional and Neurobiological Properties of Bad Taste. Physiol Rev 2019; 99:605-663. [PMID: 30475657 PMCID: PMC6442928 DOI: 10.1152/physrev.00044.2017] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 05/18/2018] [Accepted: 06/30/2018] [Indexed: 12/12/2022] Open
Abstract
The gustatory system serves as a critical line of defense against ingesting harmful substances. Technological advances have fostered the characterization of peripheral receptors and have created opportunities for more selective manipulations of the nervous system, yet the neurobiological mechanisms underlying taste-based avoidance and aversion remain poorly understood. One conceptual obstacle stems from a lack of recognition that taste signals subserve several behavioral and physiological functions which likely engage partially segregated neural circuits. Moreover, although the gustatory system evolved to respond expediently to broad classes of biologically relevant chemicals, innate repertoires are often not in register with the actual consequences of a food. The mammalian brain exhibits tremendous flexibility; responses to taste can be modified in a specific manner according to bodily needs and the learned consequences of ingestion. Therefore, experimental strategies that distinguish between the functional properties of various taste-guided behaviors and link them to specific neural circuits need to be applied. Given the close relationship between the gustatory and visceroceptive systems, a full reckoning of the neural architecture of bad taste requires an understanding of how these respective sensory signals are integrated in the brain.
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Affiliation(s)
- Lindsey A Schier
- Department of Biological Sciences, University of Southern California , Los Angeles, California ; and Department of Psychology and Program in Neuroscience, Florida State University , Tallahassee, Florida
| | - Alan C Spector
- Department of Biological Sciences, University of Southern California , Los Angeles, California ; and Department of Psychology and Program in Neuroscience, Florida State University , Tallahassee, Florida
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82
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Zhang X, Hu M, Yang Y, Xu H. Organellar TRP channels. Nat Struct Mol Biol 2018; 25:1009-1018. [PMID: 30374082 DOI: 10.1038/s41594-018-0148-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 09/28/2018] [Indexed: 02/08/2023]
Abstract
Mammalian transient receptor potential (TRP) channels mediate Ca2+ flux and voltage changes across membranes in response to environmental and cellular signals. At the plasma membrane, sensory TRPs act as neuronal detectors of physical and chemical environmental signals, and receptor-operated (metabotropic) TRPs decode extracellular neuroendocrine cues to control body homeostasis. In intracellular membranes, such as those in lysosomes, organellar TRPs respond to compartment-derived signals to control membrane trafficking, signal transduction, and organelle function. Complementing mouse and human genetics and high-resolution structural approaches, physiological studies employing natural agonists and synthetic inhibitors have become critical in resolving the in vivo functions of metabotropic, sensory, and organellar TRPs.
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Affiliation(s)
- Xiaoli Zhang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Meiqin Hu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.,Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Yexin Yang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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83
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Khan AS, Hichami A, Khan NA. Taste perception and its effects on oral nutritional supplements in younger life phases. Curr Opin Clin Nutr Metab Care 2018; 21:411-415. [PMID: 29939969 DOI: 10.1097/mco.0000000000000492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW The current review summarizes the importance of taste perception with regard to acceptance of oral nutritional supplements (ONS) in young children. We also shed light on how basic tastes may influence the orosensory detection of ONS in the light of genetic variations, encoding for different taste modalities, particularly for sweet and bitter (and fat), in children. RECENT FINDINGS Single nucleotide polymorphism (SNP) of bitter and sweet taste receptor genes, that is, respectively, TAS2R38 and T1R2/T1R3, may influence orosensory perception of 'bitter-made-sweet' ONS. The SNP of fat taste receptor gene, that is, CD36, might communicate with bitter taste perception. The emerging new sixth fat taste may interfere with obesity in children. SUMMARY Sweet and bitter taste modalities are innate cues, expressed by children from birth to adolescence, either by a strong preference or by food aversion. Sweet and bitter tastes also communicate with each other as sweeteners can mask bitter phenotype. The fat preference, encoded by specific lingual taste receptors, is also modulated, via its interaction with phenotype and genotype, by bitter taste. Sodium salts might interact with bitter taste. Finally, the taste modalities will impact on the intake of ONS in children as the taste phenotype changes in this population, irrespective to genotype.
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Affiliation(s)
- Amira Sayed Khan
- Physiologie de la Nutrition & Toxicologie (NUTox), UMR U1231 INSERM/Université de Bourgogne-Franche Compté (UBFC), Dijon, France
- Département de Biochimie, Biologie Cellulaire et Moléculaire, Université des Frères Mentouri, Constantine, Algeria
| | - Aziz Hichami
- Physiologie de la Nutrition & Toxicologie (NUTox), UMR U1231 INSERM/Université de Bourgogne-Franche Compté (UBFC), Dijon, France
| | - Naim Akhtar Khan
- Physiologie de la Nutrition & Toxicologie (NUTox), UMR U1231 INSERM/Université de Bourgogne-Franche Compté (UBFC), Dijon, France
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84
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Schneider C, O'Leary CE, von Moltke J, Liang HE, Ang QY, Turnbaugh PJ, Radhakrishnan S, Pellizzon M, Ma A, Locksley RM. A Metabolite-Triggered Tuft Cell-ILC2 Circuit Drives Small Intestinal Remodeling. Cell 2018; 174:271-284.e14. [PMID: 29887373 PMCID: PMC6046262 DOI: 10.1016/j.cell.2018.05.014] [Citation(s) in RCA: 287] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 03/26/2018] [Accepted: 05/07/2018] [Indexed: 12/13/2022]
Abstract
The small intestinal tuft cell-ILC2 circuit mediates epithelial responses to intestinal helminths and protists by tuft cell chemosensory-like sensing and IL-25-mediated activation of lamina propria ILC2s. Small intestine ILC2s constitutively express the IL-25 receptor, which is negatively regulated by A20 (Tnfaip3). A20 deficiency in ILC2s spontaneously triggers the circuit and, unexpectedly, promotes adaptive small-intestinal lengthening and remodeling. Circuit activation occurs upon weaning and is enabled by dietary polysaccharides that render mice permissive for Tritrichomonas colonization, resulting in luminal accumulation of acetate and succinate, metabolites of the protist hydrogenosome. Tuft cells express GPR91, the succinate receptor, and dietary succinate, but not acetate, activates ILC2s via a tuft-, TRPM5-, and IL-25-dependent pathway. Also induced by parasitic helminths, circuit activation and small intestinal remodeling impairs infestation by new helminths, consistent with the phenomenon of concomitant immunity. We describe a metabolic sensing circuit that may have evolved to facilitate mutualistic responses to luminal pathosymbionts.
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Affiliation(s)
- Christoph Schneider
- Department of Medicine, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | - Claire E O'Leary
- Department of Medicine, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | - Jakob von Moltke
- Department of Medicine, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | - Hong-Erh Liang
- Department of Medicine, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | - Qi Yan Ang
- Department of Microbiology & Immunology, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | - Peter J Turnbaugh
- Department of Microbiology & Immunology, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | | | | | - Averil Ma
- Department of Medicine, University of California San Francisco (UCSF), San Francisco, CA 94143, USA
| | - Richard M Locksley
- Department of Medicine, University of California San Francisco (UCSF), San Francisco, CA 94143, USA; Department of Microbiology & Immunology, University of California San Francisco (UCSF), San Francisco, CA 94143, USA; Howard Hughes Medical Institute, UCSF.
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85
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Role of the TRPM4 Channel in Cardiovascular Physiology and Pathophysiology. Cells 2018; 7:cells7060062. [PMID: 29914130 PMCID: PMC6025450 DOI: 10.3390/cells7060062] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 12/31/2022] Open
Abstract
The transient receptor potential cation channel subfamily M member 4 (TRPM4) channel influences calcium homeostasis during many physiological activities such as insulin secretion, immune response, respiratory reaction, and cerebral vasoconstriction. This calcium-activated, monovalent, selective cation channel also plays a key role in cardiovascular pathophysiology; for example, a mutation in the TRPM4 channel leads to cardiac conduction disease. Recently, it has been suggested that the TRPM4 channel is also involved in the development of cardiac ischemia-reperfusion injury, which causes myocardial infarction. In the present review, we discuss the physiological function of the TRPM4 channel, and assess its role in cardiovascular pathophysiology.
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86
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Ca 2+ Regulation of TRP Ion Channels. Int J Mol Sci 2018; 19:ijms19041256. [PMID: 29690581 PMCID: PMC5979445 DOI: 10.3390/ijms19041256] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 12/20/2022] Open
Abstract
Ca2+ signaling influences nearly every aspect of cellular life. Transient receptor potential (TRP) ion channels have emerged as cellular sensors for thermal, chemical and mechanical stimuli and are major contributors to Ca2+ signaling, playing an important role in diverse physiological and pathological processes. Notably, TRP ion channels are also one of the major downstream targets of Ca2+ signaling initiated either from TRP channels themselves or from various other sources, such as G-protein coupled receptors, giving rise to feedback regulation. TRP channels therefore function like integrators of Ca2+ signaling. A growing body of research has demonstrated different modes of Ca2+-dependent regulation of TRP ion channels and the underlying mechanisms. However, the precise actions of Ca2+ in the modulation of TRP ion channels remain elusive. Advances in Ca2+ regulation of TRP channels are critical to our understanding of the diversified functions of TRP channels and complex Ca2+ signaling.
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