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Moribayashi T, Nakao Y, Ohtubo Y. Characteristics of A-type voltage-gated K + currents expressed on sour-sensing type III taste receptor cells in mice. Cell Tissue Res 2024; 396:353-369. [PMID: 38492001 PMCID: PMC11144136 DOI: 10.1007/s00441-024-03887-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
Sour taste is detected by type III taste receptor cells that generate membrane depolarization with action potentials in response to HCl applied to the apical membranes. The shape of action potentials in type III cells exhibits larger afterhyperpolarization due to activation of transient A-type voltage-gated K+ currents. Although action potentials play an important role in neurotransmitter release, the electrophysiological features of A-type K+ currents in taste buds remain unclear. Here, we examined the electrophysiological properties of A-type K+ currents in mouse fungiform taste bud cells using in-situ whole-cell patch clamping. Type III cells were identified with SNAP-25 immunoreactivity and/or electrophysiological features of voltage-gated currents. Type III cells expressed A-type K+ currents which were completely inhibited by 10 mM TEA, whereas IP3R3-immunoreactive type II cells did not. The half-maximal activation and steady-state inactivation of A-type K+ currents were 17.9 ± 4.5 (n = 17) and - 11.0 ± 5.7 (n = 17) mV, respectively, which are similar to the features of Kv3.3 and Kv3.4 channels (transient and high voltage-activated K+ channels). The recovery from inactivation was well fitted with a double exponential equation; the fast and slow time constants were 6.4 ± 0.6 ms and 0.76 ± 0.26 s (n = 6), respectively. RT-PCR experiments suggest that Kv3.3 and Kv3.4 mRNAs were detected at the taste bud level, but not at single-cell levels. As the phosphorylation of Kv3.3 and Kv3.4 channels generally leads to the modulation of cell excitability, neuromodulator-mediated A-type K+ channel phosphorylation likely affects the signal transduction of taste.
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Affiliation(s)
- Takeru Moribayashi
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Hibikino 2-4, Kitakyushu, 808-0196, Japan
| | - Yoshiki Nakao
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Hibikino 2-4, Kitakyushu, 808-0196, Japan
| | - Yoshitaka Ohtubo
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Hibikino 2-4, Kitakyushu, 808-0196, Japan.
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2
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Yamashita A, Ota MS. A quantitative study of the development of taste pores in mice. J Oral Biosci 2024; 66:241-248. [PMID: 38342298 DOI: 10.1016/j.job.2024.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/13/2024]
Abstract
OBJECTIVES This study determined the early development of taste buds by observing the changes in the three-dimensional structures of taste pores and microvilli in the circumvallate papillae (CVP) of mice, from pre- and postnatal stages to the adult stages. METHODS Fragments of mouse CVP tissue were collected on embryonic day (E) 18 and postnatal days (P) 0, 3, 6, 7, 14, 21, 28, and 56. The surfaces of the tissue fragments located pore apertures via scanning electron microscopy, and the sizes of the CVP and maximum diameters of the pores were estimated from the recorded images. Likewise, changes in the structures of the epithelium around the pore aperture and microvilli protruding from the pores were examined. RESULTS The size of the CVP exhibited a linear increase with age from E18 to P56. The epithelium around the pore aperture demonstrated changes to form microridges, indicating a characteristic pattern during CVP development. The size of the pore aperture also increased with age from E18 to P56. Furthermore, an increase in the number of pores with protruding microvilli was observed at the base of the epithelial trench. A significant positive correlation was observed between the maximum diameter of the pore and the size of the CVP. CONCLUSIONS The expansion in the lateral view of the CVP was associated with the developmental stage from E18 to P56, suggesting that the growth of the CVP leads to the opening and enlargement of the taste pores with microvillus projections during these stages.
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Affiliation(s)
- Atsuko Yamashita
- Laboratory of Anatomy, Physiology and Food Biological Science, Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-Ku, Tokyo, 112-8681, Japan.
| | - Masato S Ota
- Laboratory of Anatomy, Physiology and Food Biological Science, Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-Ku, Tokyo, 112-8681, Japan.
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3
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Landon SM, Baker K, Macpherson LJ. Give-and-take of gustation: the interplay between gustatory neurons and taste buds. Chem Senses 2024; 49:bjae029. [PMID: 39078723 PMCID: PMC11315769 DOI: 10.1093/chemse/bjae029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2024] Open
Abstract
Mammalian taste buds are highly regenerative and can restore themselves after normal wear and tear of the lingual epithelium or following physical and chemical insults, including burns, chemotherapy, and nerve injury. This is due to the continual proliferation, differentiation, and maturation of taste progenitor cells, which then must reconnect with peripheral gustatory neurons to relay taste signals to the brain. The turnover and re-establishment of peripheral taste synapses are vital to maintain this complex sensory system. Over the past several decades, the signal transduction and neurotransmitter release mechanisms within taste cells have been well delineated. However, the complex dynamics between synaptic partners in the tongue (taste cell and gustatory neuron) are only partially understood. In this review, we highlight recent findings that have improved our understanding of the mechanisms governing connectivity and signaling within the taste bud and the still-unresolved questions regarding the complex interactions between taste cells and gustatory neurons.
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Affiliation(s)
- Shannon M Landon
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, United States
| | - Kimberly Baker
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, United States
- 59th Medical Wing: Surgical and Technological Advancements for Traumatic Injuries in Combat: 204 Wagner Ave, San Antonio, TX 78211, United States
| | - Lindsey J Macpherson
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, United States
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, United States
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4
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Ikenaga T, Nakamura T, Tajiri T, Tsuji M, Kato DI, Ineno T, Kobayashi Y, Tsutsui N, Kiyohara S. Diversity and evolution of serotonergic cells in taste buds of elasmobranchs and ancestral actinopterygian fish. Cell Tissue Res 2023; 394:431-439. [PMID: 37851111 DOI: 10.1007/s00441-023-03837-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 10/05/2023] [Indexed: 10/19/2023]
Abstract
A subset of gustatory cells are serotonin immunoreactive (ir) in the mammalian taste bud. In the taste bud of lamprey, elongated gustatory-like cells are also serotonin-ir. In contrast, flattened serotonin-ir cells are located only in the basal region of the taste buds in the teleosts and amphibians. These serotonin-ir cells are termed as basal cells. To evaluate the evolution and diversity of serotonergic cells in the taste bud of amniote animals, we explored the distribution and morphology of serotonin-ir cells in the taste buds of ancestral actinopterygian fish (spotted gar, sturgeon, Polypterus senegalus) and elasmobranch (stingray). In all examined animals, the taste buds contained serotonin-ir cells in their basal part. The number of serotonin-ir basal cells in each taste bud was different between these fish species. They were highest in the stingray and decreased in the order of the Polypterus, sturgeon, and gar. While serotonin immunoreactivity was observed only in the basal cells in the taste buds of the ancestral actinopterygian fish, some elongated cells were also serotonin-ir in addition to the basal cells in the stingray taste buds. mRNA of tryptophan hydroxylase 1 (tph1), a rate-limiting enzyme of the serotonin synthesis, is expressed in both the elongated and basal cells of stingray taste buds, indicating that these cells synthesize the serotonin by themselves. These results suggest that the serotonin-ir basal cells arose from the ancestor of the cartilaginous fish, and serotonin-ir cells in the elasmobranch taste bud exhibit an intermediate aspect between the lamprey and actinopterygian fish.
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Affiliation(s)
- Takanori Ikenaga
- Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-0065, Japan.
| | - Tastufumi Nakamura
- Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Tatsushi Tajiri
- Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Minaki Tsuji
- Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Dai-Ichiro Kato
- Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Toshinao Ineno
- Aquaculture Research Institute, Shingu Station, Kindai University, Wakayama, Japan
| | - Yasuhisa Kobayashi
- Department of Fisheries, Faculty of Agriculture, Kindai University, Nara, 631-0052, Japan
- Faculty of Science, Ushimado Marine Institute (UMI), Okayama University, Okayama, 701-4303, Japan
| | - Naoaki Tsutsui
- Department of Life Sciences, Graduate School of Bioresources, Mie University, Mie, 514-8507, Japan
- Faculty of Science, Ushimado Marine Institute (UMI), Okayama University, Okayama, 701-4303, Japan
| | - Sadao Kiyohara
- Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-0065, Japan
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5
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Hichami A, Saidi H, Khan AS, Degbeni P, Khan NA. In Vitro Functional Characterization of Type-I Taste Bud Cells as Monocytes/Macrophages-like Which Secrete Proinflammatory Cytokines. Int J Mol Sci 2023; 24:10325. [PMID: 37373472 DOI: 10.3390/ijms241210325] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/14/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023] Open
Abstract
The sense of taste determines the choice of nutrients and food intake and, consequently, influences feeding behaviors. The taste papillae are primarily composed of three types of taste bud cells (TBC), i.e., type I, type II, and type III. The type I TBC, expressing GLAST (glutamate--aspartate transporter), have been termed as glial-like cells. We hypothesized that these cells could play a role in taste bud immunity as glial cells do in the brain. We purified type I TBC, expressing F4/80, a specific marker of macrophages, from mouse fungiform taste papillae. The purified cells also express CD11b, CD11c, and CD64, generally expressed by glial cells and macrophages. We further assessed whether mouse type I TBC can be polarized toward M1 or M2 macrophages in inflammatory states like lipopolysaccharide (LPS)-triggered inflammation or obesity, known to be associated with low-grade inflammation. Indeed, LPS-treatment and obesity state increased TNFα, IL-1β, and IL-6 expression, both at mRNA and protein levels, in type I TBC. Conversely, purified type I TBC treated with IL-4 showed a significant increase in arginase 1 and IL-4. These findings provide evidence that type I gustatory cells share many features with macrophages and may be involved in oral inflammation.
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Affiliation(s)
- Aziz Hichami
- Physiologie de la Nutrition & Toxicologie, UMR INSERM U1231 Lipide, Nutrition & Cancer, Université de Bourgogne, 21000 Dijon, France
| | - Hamza Saidi
- Physiologie de la Nutrition & Toxicologie, UMR INSERM U1231 Lipide, Nutrition & Cancer, Université de Bourgogne, 21000 Dijon, France
- Bioenergetics and Intermediary Metabolism Team, Laboratory of Biology and Organisms Physiology, University of Sciences and Technology Houari Boumediene, Algiers 16111, Algeria
| | - Amira Sayed Khan
- Physiologie de la Nutrition & Toxicologie, UMR INSERM U1231 Lipide, Nutrition & Cancer, Université de Bourgogne, 21000 Dijon, France
| | - Pernelle Degbeni
- Physiologie de la Nutrition & Toxicologie, UMR INSERM U1231 Lipide, Nutrition & Cancer, Université de Bourgogne, 21000 Dijon, France
| | - Naim Akhtar Khan
- Physiologie de la Nutrition & Toxicologie, UMR INSERM U1231 Lipide, Nutrition & Cancer, Université de Bourgogne, 21000 Dijon, France
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6
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Langhans W, Watts AG, Spector AC. The elusive cephalic phase insulin response: triggers, mechanisms, and functions. Physiol Rev 2023; 103:1423-1485. [PMID: 36422994 PMCID: PMC9942918 DOI: 10.1152/physrev.00025.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/04/2022] [Accepted: 11/20/2022] [Indexed: 11/25/2022] Open
Abstract
The cephalic phase insulin response (CPIR) is classically defined as a head receptor-induced early release of insulin during eating that precedes a postabsorptive rise in blood glucose. Here we discuss, first, the various stimuli that elicit the CPIR and the sensory signaling pathways (sensory limb) involved; second, the efferent pathways that control the various endocrine events associated with eating (motor limb); and third, what is known about the central integrative processes linking the sensory and motor limbs. Fourth, in doing so, we identify open questions and problems with respect to the CPIR in general. Specifically, we consider test conditions that allow, or may not allow, the stimulus to reach the potentially relevant taste receptors and to trigger a CPIR. The possible significance of sweetness and palatability as crucial stimulus features and whether conditioning plays a role in the CPIR are also discussed. Moreover, we ponder the utility of the strict classical CPIR definition based on what is known about the effects of vagal motor neuron activation and thereby acetylcholine on the β-cells, together with the difficulties of the accurate assessment of insulin release. Finally, we weigh the evidence of the physiological and clinical relevance of the cephalic contribution to the release of insulin that occurs during and after a meal. These points are critical for the interpretation of the existing data, and they support a sharper focus on the role of head receptors in the overall insulin response to eating rather than relying solely on the classical CPIR definition.
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Affiliation(s)
- Wolfgang Langhans
- Physiology and Behavior Laboratory, ETH Zürich, Schwerzenbach, Switzerland
| | - Alan G Watts
- Department of Biological Sciences, USC Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Alan C Spector
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
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7
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Doyle ME, Premathilake HU, Yao Q, Mazucanti CH, Egan JM. Physiology of the tongue with emphasis on taste transduction. Physiol Rev 2023; 103:1193-1246. [PMID: 36422992 PMCID: PMC9942923 DOI: 10.1152/physrev.00012.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The tongue is a complex multifunctional organ that interacts and senses both interoceptively and exteroceptively. Although it is easily visible to almost all of us, it is relatively understudied and what is in the literature is often contradictory or is not comprehensively reported. The tongue is both a motor and a sensory organ: motor in that it is required for speech and mastication, and sensory in that it receives information to be relayed to the central nervous system pertaining to the safety and quality of the contents of the oral cavity. Additionally, the tongue and its taste apparatus form part of an innate immune surveillance system. For example, loss or alteration in taste perception can be an early indication of infection as became evident during the present global SARS-CoV-2 pandemic. Here, we particularly emphasize the latest updates in the mechanisms of taste perception, taste bud formation and adult taste bud renewal, and the presence and effects of hormones on taste perception, review the understudied lingual immune system with specific reference to SARS-CoV-2, discuss nascent work on tongue microbiome, as well as address the effect of systemic disease on tongue structure and function, especially in relation to taste.
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Affiliation(s)
- Máire E Doyle
- Diabetes Section/Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | - Hasitha U Premathilake
- Diabetes Section/Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | - Qin Yao
- Diabetes Section/Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | - Caio H Mazucanti
- Diabetes Section/Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | - Josephine M Egan
- Diabetes Section/Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
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8
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Matsuyama K, Takai S, Shigemura N, Nakatomi M, Kawamoto T, Kataoka S, Toyono T, Seta Y. Ascl1-expressing cell differentiation in initially developed taste buds and taste organoids. Cell Tissue Res 2023:10.1007/s00441-023-03756-8. [PMID: 36781481 DOI: 10.1007/s00441-023-03756-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
Mammalian taste bud cells are composed of several distinct cell types and differentiated from surrounding tongue epithelial cells. However, the detailed mechanisms underlying their differentiation have yet to be elucidated. In the present study, we examined an Ascl1-expressing cell lineage using circumvallate papillae (CVP) of newborn mice and taste organoids (three-dimensional self-organized tissue cultures), which allow studying the differentiation of taste bud cells in fine detail ex vivo. Using lineage-tracing analysis, we observed that Ascl1 lineage cells expressed type II and III taste cell markers both CVP of newborn mice and taste organoids. However, the coexpression rate in type II cells was lower than that in type III cells. Furthermore, we found that the generation of the cells which express type II and III cell markers was suppressed in taste organoids lacking Ascl1-expressing cells. These findings suggest that Ascl1-expressing precursor cells can differentiate into both type III and a subset of type II taste cells.
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Affiliation(s)
- Kae Matsuyama
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan.
| | - Shingo Takai
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Noriatsu Shigemura
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.,Research and Development Center for Five-Sense Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Tatsuo Kawamoto
- Division of Orofacial Functions and Orthodontics, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Shinji Kataoka
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Takashi Toyono
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Yuji Seta
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
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9
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Dutta Banik D, Medler KF. Defining the role of TRPM4 in broadly responsive taste receptor cells. Front Cell Neurosci 2023; 17:1148995. [PMID: 37032837 PMCID: PMC10073513 DOI: 10.3389/fncel.2023.1148995] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
Peripheral taste receptor cells use multiple signaling pathways to transduce taste stimuli into output signals that are sent to the brain. We have previously identified a subpopulation of Type III taste cells that are broadly responsive (BR) and respond to multiple taste stimuli including bitter, sweet, umami, and sour. These BR cells use a PLCβ3/IP3R1 signaling pathway to detect bitter, sweet, and umami stimuli and use a separate pathway to detect sour. Currently, the downstream targets of the PLCβ3 signaling pathway are unknown. Here we identify TRPM4, a monovalent selective TRP channel, as an important downstream component in this signaling pathway. Using live cell imaging on isolated taste receptor cells from mice, we show that inhibition of TRPM4 abolished the taste-evoked sodium responses and significantly reduced the taste-evoked calcium responses in BR cells. Since BR cells are a subpopulation of Type III taste cells, they have conventional chemical synapses that require the activation of voltage-gated calcium channels (VGCCs) to cause neurotransmitter release. We found that TRPM4-dependent membrane depolarization selectively activates L-type VGCCs in these cells. The calcium influx through L-type VGCCs also generates a calcium-induced calcium release (CICR) via ryanodine receptors that enhances TRPM4 activity. Together these signaling events amplify the initial taste response to generate an appropriate output signal.
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10
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Matsumoto K, Kamide M, Uchida K, Takahata M, Shichiri R, Hida Y, Taniguchi Y, Ohishi A, Tominaga M, Nagasawa K, Kato S. Transient Receptor Potential Ankyrin 1 in Taste Nerve Contributes to the Sense of Sweet Taste in Mice. Biol Pharm Bull 2023; 46:939-945. [PMID: 37394645 DOI: 10.1248/bpb.b23-00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Transient receptor potential (TRP) channels play a significant role in taste perception. TRP ankyrin 1 (TRPA1) is present in the afferent sensory neurons and is activated by food-derived ingredients, such as Japanese horseradish, cinnamon, and garlic. The present study aimed to investigate the expression of TRPA1 in taste buds, and determine its functional roles in taste perception using TRPA1-deficient mice. In circumvallate papillae, TRPA1 immunoreactivity colocalised with P2X2 receptor-positive taste nerves but not with type II or III taste cell markers. Behavioural studies showed that TRPA1 deficiency significantly reduced sensitivity to sweet and umami tastes, but not to salty, bitter, and sour tastes, compared to that in wild-type animals. Furthermore, administration of the TRPA1 antagonist HC030031 significantly decreased taste preference to sucrose solution compared to that in the vehicle-treated group in the two-bottle preference tests. TRPA1 deficiency did not affect the structure of circumvallate papillae or the expression of type II or III taste cell and taste nerve markers. Adenosine 5'-O-(3-thio)triphosphate evoked inward currents did not differ between P2X2- and P2X2/TRPA1-expressing human embryonic kidney 293T cells. TRPA1-deficient mice had significantly decreased c-fos expression in the nucleus of the solitary tract in the brain stem following sucrose stimulation than wild-type mice. Taken together, the current study suggested that TRPA1 in the taste nerve contributes to the sense of sweet taste in mice.
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Affiliation(s)
- Kenjiro Matsumoto
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
| | - Mayu Kamide
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
| | - Kunitoshi Uchida
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka
- Laboratory of Functional Physiology, Department of Environmental and Life Sciences, School of Food and Nutritional Sciences, University of Shizuoka
| | - Mitsuki Takahata
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
| | - Runa Shichiri
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
| | - Yuka Hida
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
| | - Yumi Taniguchi
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
| | - Akihiro Ohishi
- Division of Biological Sciences, Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Makoto Tominaga
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences)
| | - Kazuki Nagasawa
- Division of Biological Sciences, Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Shinichi Kato
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University
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11
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The roles of two extracellular loops in proton sensing and permeation in human Otop1 proton channel. Commun Biol 2022; 5:1110. [PMID: 36266567 PMCID: PMC9585144 DOI: 10.1038/s42003-022-04085-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/07/2022] [Indexed: 11/08/2022] Open
Abstract
Otopetrin (Otop) proteins were recently found to function as proton channels, with Otop1 revealed to be the sour taste receptor in mammals. Otop proteins contain twelve transmembrane segments (S1-S12) which are divided into structurally similar N and C domains. The mechanisms by which Otop channels sense extracellular protons to initiate gating and conduct protons once the channels are activated remains largely elusive. Here we show that two extracellular loops are playing key roles in human Otop1 channel function. We find that residue H229 in the S5-S6 loop is critical for proton sensing of Otop1. Further, our data reveal that the S11-12 loop is structurally and functionally essential for the Otop1 channel and that residue D570 in this loop regulates proton permeation into the pore formed by the C domain. This study sheds light on the molecular mechanism behind the structure and function of this newly identified ion channel family. Electrophysiology experiments, mutagenesis, and structural modelling provide insights into the structure and function of the sour taste receptor Otopetrin 1.
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12
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Tian Y, Wang P, Du L, Wu C. Advances in gustatory biomimetic biosensing technologies: In vitro and in vivo bioelectronic tongue. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Nakao Y, Tateno K, Ohtubo Y. Taste Receptor Cells Generate Oscillating Receptor Potentials by Activating G Protein-Coupled Taste Receptors. Front Physiol 2022; 13:883372. [PMID: 35694396 PMCID: PMC9174655 DOI: 10.3389/fphys.2022.883372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/27/2022] [Indexed: 11/15/2022] Open
Abstract
The receptor potentials of taste receptor cells remain unclear. Here, we demonstrate that taste receptor cells generate oscillating depolarization (n = 7) with action potentials in response to sweet, bitter, umami, and salty taste substances. At a lower concentration of taste substances, taste receptor cells exhibited oscillations in membrane potentials with a low frequency and small magnitude of depolarization. Although the respective waves contained no or 1–2 action potentials, the taste receptor cells generated action potentials continuously in the presence of taste stimuli. Both the frequency and magnitude of oscillations increased when the concentration was increased, to 0.67–1.43 Hz (n = 3) and Δ39–53 mV (n = 3) in magnitude from −64.7 ± 4.2 to −18.7 ± 5.9 mV, which may activate the ATP-permeable ion channels. In contrast, a sour tastant (10-mM HCl) induced membrane depolarization (Δ19.4 ± 9.5 mV, n = 4) with action potentials in type III taste receptor cells. Interestingly, NaCl (1 M) taste stimuli induced oscillation (n = 2) or depolarization (Δ10.5 ± 5.7 mV at the tonic component, n = 9). Our results indicate that the frequency and magnitude of oscillations increased with increasing taste substance concentrations. These parameters may contribute to the expression of taste “thickness.”
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Dong H, Liu J, Zhu J, Zhou Z, Tizzano M, Peng X, Zhou X, Xu X, Zheng X. Oral Microbiota-Host Interaction Mediated by Taste Receptors. Front Cell Infect Microbiol 2022; 12:802504. [PMID: 35425718 PMCID: PMC9004699 DOI: 10.3389/fcimb.2022.802504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Taste receptors, originally identified in taste buds, function as the periphery receptors for taste stimuli and play an important role in food choice. Cohort studies have revealed that single nucleotide polymorphisms of taste receptors such as T1R1, T1R2, T2R38 are associated with susceptibility to oral diseases like dental caries. Recent studies have demonstrated the wide expression of taste receptors in various tissues, including intestinal epithelia, respiratory tract, and gingiva, with an emerging role of participating in the interaction between mucosa surface and microorganisms via monitoring a wide range of metabolites. On the one hand, individuals with different oral microbiomes exhibited varied taste sensitivity, suggesting a potential impact of the oral microbiota composition on taste receptor function. On the other hand, animal studies and in vitro studies have uncovered that a variety of oral cells expressing taste receptors such as gingival solitary chemosensory cells, gingival epithelial cells (GECs), and gingival fibroblasts can detect bacterial signals through bitter taste receptors to trigger host innate immune responses, thus regulating oral microbial homeostasis. This review focuses on how taste receptors, particularly bitter and sweet taste receptors, mediate the oral microbiota-host interaction as well as impact the occurrence and development of oral diseases. Further studies delineating the role of taste receptors in mediating oral microbiota-host interaction will advance our knowledge in oral ecological homeostasis establishment, providing a novel paradigm and treatment target for the better management of dental infectious diseases.
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Affiliation(s)
- Hao Dong
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jiaxin Liu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jianhui Zhu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Hangzhou, China
- Clinical Research Center for Oral Diseases of Zhejiang Province, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, China
| | - Zhiyan Zhou
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Marco Tizzano
- Basic and Translation Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Xian Peng
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xin Xu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- *Correspondence: Xin Zheng, ; Xin Xu,
| | - Xin Zheng
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- *Correspondence: Xin Zheng, ; Xin Xu,
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15
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Intranasal calcitonin gene-related peptide administration impairs fear memory retention in mice through the PKD/p-HDAC5/Npas4 pathway. Sci Rep 2022; 12:1450. [PMID: 35087146 PMCID: PMC8795377 DOI: 10.1038/s41598-022-05518-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/13/2022] [Indexed: 12/15/2022] Open
Abstract
The calcitonin gene-related peptide (CGRP) suppresses fear memory retention in mice. Although intracerebroventricular administration of CGRP alters the fear memory processes, making it a promising therapeutic strategy for post-traumatic stress disorder (PTSD), direct brain injection into patients is not practical. Therefore, we propose that intranasal application may be an effective way to deliver CGRP to the brain. This study tested whether CGRP nasal administration exerts the same effect as intracerebroventricular administration using C57BL6J mice. The amount of CGRP in the cerebrospinal fluid and hippocampus 30 min after nasal administration of CGRP was significantly higher when compared with saline. Intranasal CGRP also elicited photophobic behaviors similar to intracerebroventricular injection. Moreover, intranasal CGRP decreased fear memory retention but did not affect reactivation and extinction of fear memory. We found intranasal CGRP significantly increased the expression of protein kinase D (PKD), phosphorylated histone deacetylase 5 (p-HDAC5) and neuronal PAS domain protein 4 (Npas4) in the hippocampus. CGRP-mediated impairment of fear memory and Npas4 expression increases were attenuated significantly by the CGRP receptor antagonist BIBN4096. Together, our data demonstrate that intranasal CGRP delivery activates the PKD/p-HDAC5/Npas4 pathway, decreases fear memory retention.
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16
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Yoshida Y, Nishimura S, Tabata S, Kawabata F. Chicken taste receptors and perception: recent advances in our understanding of poultry nutrient-sensing systems. WORLD POULTRY SCI J 2021. [DOI: 10.1080/00439339.2022.2007437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Yuta Yoshida
- Department of Food and Life Sciences, College of Agriculture, Ibaraki University, Ami, Japan
| | - Shotaro Nishimura
- Laboratory of Functional Anatomy, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Shoji Tabata
- Laboratory of Functional Anatomy, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Fuminori Kawabata
- Physiology of Domestic Animals, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
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17
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Wu C, Zhu P, Liu Y, Du L, Wang P. Field-Effect Sensors Using Biomaterials for Chemical Sensing. SENSORS 2021; 21:s21237874. [PMID: 34883883 PMCID: PMC8659547 DOI: 10.3390/s21237874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 12/21/2022]
Abstract
After millions of years of evolution, biological chemical sensing systems (i.e., olfactory and taste systems) have become very powerful natural systems which show extreme high performances in detecting and discriminating various chemical substances. Creating field-effect sensors using biomaterials that are able to detect specific target chemical substances with high sensitivity would have broad applications in many areas, ranging from biomedicine and environments to the food industry, but this has proved extremely challenging. Over decades of intense research, field-effect sensors using biomaterials for chemical sensing have achieved significant progress and have shown promising prospects and potential applications. This review will summarize the most recent advances in the development of field-effect sensors using biomaterials for chemical sensing with an emphasis on those using functional biomaterials as sensing elements such as olfactory and taste cells and receptors. Firstly, unique principles and approaches for the development of these field-effect sensors using biomaterials will be introduced. Then, the major types of field-effect sensors using biomaterials will be presented, which includes field-effect transistor (FET), light-addressable potentiometric sensor (LAPS), and capacitive electrolyte–insulator–semiconductor (EIS) sensors. Finally, the current limitations, main challenges and future trends of field-effect sensors using biomaterials for chemical sensing will be proposed and discussed.
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Affiliation(s)
- Chunsheng Wu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Science, Health Science Center, Xi’an Jiaotong University, Xi’an 710061, China; (C.W.); (P.Z.); (Y.L.); (L.D.)
| | - Ping Zhu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Science, Health Science Center, Xi’an Jiaotong University, Xi’an 710061, China; (C.W.); (P.Z.); (Y.L.); (L.D.)
| | - Yage Liu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Science, Health Science Center, Xi’an Jiaotong University, Xi’an 710061, China; (C.W.); (P.Z.); (Y.L.); (L.D.)
| | - Liping Du
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Science, Health Science Center, Xi’an Jiaotong University, Xi’an 710061, China; (C.W.); (P.Z.); (Y.L.); (L.D.)
| | - Ping Wang
- Biosensor National Special Laboratory, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China
- Correspondence:
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18
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Huang S, Zhang T, Li H, Zhang M, Liu X, Xu D, Wang H, Shen Z, Wu Q, Tao J, Xia W, Xie X, Liu F. Flexible Tongue Electrode Array System for In Vivo Mapping of Electrical Signals of Taste Sensation. ACS Sens 2021; 6:4108-4117. [PMID: 34757732 DOI: 10.1021/acssensors.1c01621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tongue is a unique organ that senses tastes, and the scientific puzzle about whether electricity can evoke taste sensations and how the sensations have been distributed on the tongue has not been solved. Investigations on tongue stimulation by electricity might benefit the developments of techniques for clinical neuromodulation, tissue activation, and a brain-tongue-machine interface. To solve the scientific puzzle of whether electrical stimulation induces taste-related sensations, a portable flexible tongue electrode array system (FTEAS) was developed, which can synchronously provide electrical stimulation and signal mapping at each zone of the tongue. Utilizing the FTEAS to perform tests on the rat tongue in vivo, specific electrical signals were observed to be evoked by chemical and electrical stimulations. The features and distributions of the electric signals evoked during the rat tongue tests were systematically studied and comprehensively analyzed. The results show that an appropriate electrical stimulation can induce multiple sensations simultaneously, while the distribution of each sensation was not significantly distinguished among different zones of the tongue, and at the same time, this taste-related electrical signal can be recorded by the FTEAS. This work establishes a promising platform to solve the scientific puzzle of how sensations are activated chemically and electrically on the tongue and may provide advanced noninvasive oral-electrotherapy and a brain-tongue-machine interface.
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Affiliation(s)
- Shuang Huang
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Tao Zhang
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Hongbo Li
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Mingyue Zhang
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Xingxing Liu
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Dongxin Xu
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Hao Wang
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhiran Shen
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Qianni Wu
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jun Tao
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Wenhao Xia
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Xi Xie
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Fanmao Liu
- The First Affiliated Hospital of Sun Yat-sen University, School of Electronics and Information Technology, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510006, China
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D'Urso O, Drago F. Pharmacological significance of extra-oral taste receptors. Eur J Pharmacol 2021; 910:174480. [PMID: 34496302 DOI: 10.1016/j.ejphar.2021.174480] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/23/2021] [Accepted: 09/01/2021] [Indexed: 01/17/2023]
Abstract
It has recently been shown that taste receptors, in addition to being present in the oral cavity, exist in various extra-oral organs and tissues such as the thyroid, lungs, skin, stomach, intestines, and pancreas. Although their physiological function is not yet fully understood, it appears that they can help regulate the body's homeostasis and provide an additional defense function against pathogens. Since the vast majority of drugs are bitter, the greatest pharmacological interest is in the bitter taste receptors. In this review, we describe how bitter taste 2 receptors (TAS2Rs) induce bronchodilation and mucociliary clearance in the airways, muscle relaxation in various tissues, inhibition of thyroid stimulating hormone (TSH) in thyrocytes, and release of glucagon-like peptide-1 (GLP-1) and ghrelin in the digestive system. In fact, substances such as dextromethorphan, chloroquine, methimazole and probably glimepiride, being agonists of TAS2Rs, lead to these effects. TAS2Rs and taste 1 receptors (TAS1R2/3) are G protein-coupled receptors (GPCR). TAS1R2/3 are responsible for sweet taste perception and may induce GLP-1 release and insulin secretion. Umami taste receptors, belonging to the same superfamily of receptors, perform a similar function with regard to insulin. The sour and salty taste receptors work in a similar way, both being channel receptors sensitive to amiloride. Finally, gene-protein coupled receptor 40 (GPR40) and GPR120 for fatty taste perception are also protein-coupled receptors and may induce GLP-1 secretion and insulin release, similar to those of other receptors belonging to the same superfamily.
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Affiliation(s)
- Ottavio D'Urso
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia, 97, 95125 Catania, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia, 97, 95125 Catania, Italy.
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20
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Gutierrez R, Simon SA. Physiology of Taste Processing in the Tongue, Gut, and Brain. Compr Physiol 2021; 11:2489-2523. [PMID: 34558667 DOI: 10.1002/cphy.c210002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The gustatory system detects and informs us about the nature of various chemicals we put in our mouth. Some of these have nutritive value (sugars, amino acids, salts, and fats) and are appetitive and avidly ingested, whereas others (atropine, quinine, nicotine) are aversive and rapidly rejected. However, the gustatory system is mainly responsible for evoking the perception of a limited number of qualities that humans taste as sweet, umami, bitter, sour, salty, and perhaps fat [free fatty acids (FFA)] and starch (malto-oligosaccharides). The complex flavors and mouthfeel that we experience while eating food result from the integration of taste, odor, texture, pungency, and temperature. The latter three arise primarily from the somatosensory (trigeminal) system. The sensory organs used for detecting and transducing many chemicals are found in taste buds (TBs) located throughout the tongue, soft palate esophagus, and epiglottis. In parallel with the taste system, the trigeminal nerve innervates the peri-gemmal epithelium to transmit temperature, mechanical stimuli, and painful or cooling sensations such as those produced by changes in temperature as well as from chemicals like capsaicin and menthol, respectively. This article gives an overview of the current knowledge about these TB cells' anatomy and physiology and their trigeminal induced sensations. We then discuss how taste is represented across gustatory cortices using an intermingled and spatially distributed population code. Finally, we review postingestion processing (interoception) and central integration of the tongue-gut-brain interaction, ultimately determining our sensations as well as preferences toward the wholesomeness of nutritious foods. © 2021 American Physiological Society. Compr Physiol 11:1-35, 2021.
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Affiliation(s)
- Ranier Gutierrez
- Laboratory of Neurobiology of Appetite, Department of Pharmacology, CINVESTAV, Mexico City, Mexico
| | - Sidney A Simon
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
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21
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Finger T, Kinnamon S. Purinergic neurotransmission in the gustatory system. Auton Neurosci 2021; 236:102874. [PMID: 34536906 DOI: 10.1016/j.autneu.2021.102874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/13/2021] [Accepted: 08/22/2021] [Indexed: 11/26/2022]
Abstract
Taste buds consist of specialized epithelial cells which detect particular tastants and synapse onto the afferent taste nerve innervating the endorgan. The nature of the neurotransmitter released by taste cells onto the nerve fiber was enigmatic early in this century although neurotransmitters for other sensory receptor cell types, e.g. hair cells, photoreceptors, was known for at least a decade. A 1999 paper by Burnstock and co-workers (Bo et al., 1999) showing the presence of P2X receptors on the afferent nerves served as a springboard for research that ultimately led to the discovery of ATP as the crucial neurotransmitter in the taste system (Finger et al., 2005). Subsequent work showed that a subpopulation of taste cells utilize a unique release channel, CALHM1/3, to release ATP in a voltage-dependent manner. Despite these advances, several aspects of purinergic transmission in this system remain to be elucidated.
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Affiliation(s)
- T Finger
- Dept. Cell & Developmental Biology, Dept. Otolaryngology, Univ. Colorado School of Medicine, Anschutz Medical Campus, MS 8108, Room L18-11118, RC-1, 12801 E. 17th Ave., Aurora, CO 80045, United States of America.
| | - Sue Kinnamon
- Dept. Cell & Developmental Biology, Dept. Otolaryngology, Univ. Colorado School of Medicine, Anschutz Medical Campus, MS 8108, Room L18-11118, RC-1, 12801 E. 17th Ave., Aurora, CO 80045, United States of America
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22
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Yoshida Y, Kawabata F, Nishimura S, Tabata S. Overlapping distributions of mammalian types I, II, and III taste cell markers in chicken taste buds. Biochem Biophys Res Commun 2021; 570:162-168. [PMID: 34284142 DOI: 10.1016/j.bbrc.2021.07.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/01/2021] [Accepted: 07/07/2021] [Indexed: 10/20/2022]
Abstract
Mammalian taste buds comprise types I, II, and III taste cells, with each type having specific characteristics: glia-like supporting cells (type I), taste receptor cells (type II), and presynaptic cells (type III). In this study, to characterize the peripheral taste-sensing systems in chickens, we analyzed the distributions of the mammalian types I, II, and III taste cell markers in chicken taste buds: glutamate-aspartate transporter (GLAST) for type I; taste receptor type 1 members 1 and 3 (T1R1 and T1R3), taste receptor type 2 member 7 (T2R7), and α-gustducin for type II; and synaptosomal protein 25 (SNAP25) and neural cell adhesion molecule (NCAM) for type III. We found that most GLAST+ taste cells expressed α-gustducin and SNAP25 and that high percentages of T1R3+ or α-gustducin+ taste cells expressed SNAP25 and NCAM. These results demonstrated a unique subset of chicken taste cells expressing multiple taste cell type marker proteins. Taken together, these results provide new insights into the taste-sensing mechanisms in vertebrate taste buds.
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Affiliation(s)
- Yuta Yoshida
- Department of Food and Life Sciences, College of Agriculture, Ibaraki University, Ami, Japan
| | - Fuminori Kawabata
- Physiology of Domestic Animals, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan.
| | - Shotaro Nishimura
- Laboratory of Functional Anatomy, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Shoji Tabata
- Laboratory of Functional Anatomy, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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23
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Qin Y, Sukumaran SK, Margolskee RF. Nkx2-2 expressing taste cells in endoderm-derived taste papillae are committed to the type III lineage. Dev Biol 2021; 477:232-240. [PMID: 34097879 DOI: 10.1016/j.ydbio.2021.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/10/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
In mammals, multiple cell-signaling pathways and transcription factors regulate development of the embryonic taste system and turnover of taste cells in the adult stage. Using single-cell RNA-Seq of mouse taste cells, we found that the homeobox-containing transcription factor Nkx2-2, a target of the Sonic Hedgehog pathway and a key regulator of the development and regeneration of multiple cell types in the body, is highly expressed in type III taste cells but not in type II or taste stem cells. Using in situ hybridization and immunostaining, we confirmed that Nkx2-2 is expressed specifically in type III taste cells in the endoderm-derived circumvallate and foliate taste papillae but not in the ectoderm-derived fungiform papillae. Lineage tracing revealed that Nkx2-2-expressing cells differentiate into type III, but not type II or type I cells in circumvallate and foliate papillae. Neonatal Nkx2-2-knockout mice did not express key type III taste cell marker genes, while the expression of type II and type I taste cell marker genes were unaffected in these mice. Our findings indicate that Nkx2-2-expressing cells are committed to the type III lineage and that Nkx2-2 may be critical for the development of type III taste cells in the posterior tongue, thus illustrating a key difference in the mechanism of type III cell lineage specification between ectoderm- and endoderm-derived taste fields.
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Affiliation(s)
- Yumei Qin
- School of Food Science and Bioengineering, Zhejiang Gongshang University, Hangzhou, PR China; Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Sunil K Sukumaran
- Monell Chemical Senses Center, Philadelphia, PA, USA; Present Address: Department of Nutrition and Health Sciences, University of Nebraska- Lincoln, Lincoln, NE, USA.
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24
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Jang JH, Kwon O, Moon SJ, Jeong YT. Recent Advances in Understanding Peripheral Taste Decoding I: 2010 to 2020. Endocrinol Metab (Seoul) 2021; 36:469-477. [PMID: 34139798 PMCID: PMC8258330 DOI: 10.3803/enm.2021.302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/20/2021] [Indexed: 01/03/2023] Open
Abstract
Taste sensation is the gatekeeper for direct decisions on feeding behavior and evaluating the quality of food. Nutritious and beneficial substances such as sugars and amino acids are represented by sweet and umami tastes, respectively, whereas noxious substances and toxins by bitter or sour tastes. Essential electrolytes including Na+ and other ions are recognized by the salty taste. Gustatory information is initially generated by taste buds in the oral cavity, projected into the central nervous system, and finally processed to provide input signals for food recognition, regulation of metabolism and physiology, and higher-order brain functions such as learning and memory, emotion, and reward. Therefore, understanding the peripheral taste system is fundamental for the development of technologies to regulate the endocrine system and improve whole-body metabolism. In this review article, we introduce previous widely-accepted views on the physiology and genetics of peripheral taste cells and primary gustatory neurons, and discuss key findings from the past decade that have raised novel questions or solved previously raised questions.
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Affiliation(s)
- Jea Hwa Jang
- BK21 Graduate Program, Department of Biomedical Sciences, Yonsei University College of Dentistry, Seoul,
Korea
- Department of Pharmacology, Korea University College of Medicine, Yonsei University College of Dentistry, Seoul,
Korea
| | - Obin Kwon
- Departments of Biochemistry and Molecular Biology, Yonsei University College of Dentistry, Seoul,
Korea
- Biomedical Sciences, Seoul National University College of Medicine, Yonsei University College of Dentistry, Seoul,
Korea
| | - Seok Jun Moon
- Department of Oral Biology, BK21 FOUR Project, Yonsei University College of Dentistry, Seoul,
Korea
| | - Yong Taek Jeong
- BK21 Graduate Program, Department of Biomedical Sciences, Yonsei University College of Dentistry, Seoul,
Korea
- Department of Pharmacology, Korea University College of Medicine, Yonsei University College of Dentistry, Seoul,
Korea
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Vandenbeuch A, Wilson CE, Kinnamon SC. Optogenetic Activation of Type III Taste Cells Modulates Taste Responses. Chem Senses 2021; 45:533-539. [PMID: 32582939 DOI: 10.1093/chemse/bjaa044] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Studies have suggested that communication between taste cells shapes the gustatory signal before transmission to the brain. To further explore the possibility of intragemmal signal modulation, we adopted an optogenetic approach to stimulate sour-sensitive (Type III) taste cells using mice expressing Cre recombinase under a specific Type III cell promoter, Pkd2l1 (polycystic kidney disease-2-like 1), crossed with mice expressing Cre-dependent channelrhodopsin (ChR2). The application of blue light onto the tongue allowed for the specific stimulation of Type III cells and circumvented the nonspecific effects of chemical stimulation. To understand whether taste modality information is preprocessed in the taste bud before transmission to the sensory nerves, we recorded chorda tympani nerve activity during light and/or chemical tastant application to the tongue. To assess intragemmal modulation, we compared nerve responses to various tastants with or without concurrent light-induced activation of the Type III cells. Our results show that light significantly decreased taste responses to sweet, bitter, salty, and acidic stimuli. On the contrary, the light response was not consistently affected by sweet or bitter stimuli, suggesting that activation of Type II cells does not affect nerve responses to stimuli that activate Type III cells.
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Affiliation(s)
- Aurelie Vandenbeuch
- Department of Otolaryngology and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Courtney E Wilson
- Department of Otolaryngology and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sue C Kinnamon
- Department of Otolaryngology and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, CO, USA
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Ogata T, Ohtubo Y. Quantitative Analysis of Taste Bud Cell Numbers in the Circumvallate and Foliate Taste Buds of Mice. Chem Senses 2021; 45:261-273. [PMID: 32157267 DOI: 10.1093/chemse/bjaa017] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A mouse single taste bud contains 10-100 taste bud cells (TBCs) in which the elongated TBCs are classified into 3 cell types (types I-III) equipped with different taste receptors. Accordingly, differences in the cell numbers and ratios of respective cell types per taste bud may affect taste-nerve responsiveness. Here, we examined the numbers of each immunoreactive cell for the type II (sweet, bitter, or umami receptor cells) and type III (sour and/or salt receptor cells) markers per taste bud in the circumvallate and foliate papillae and compared these numerical features of TBCs per taste bud to those in fungiform papilla and soft palate, which we previously reported. In circumvallate and foliate taste buds, the numbers of TBCs and immunoreactive cells per taste bud increased as a linear function of the maximal cross-sectional taste bud area. Type II cells made up approximately 25% of TBCs irrespective of the regions from which the TBCs arose. In contrast, type III cells in circumvallate and foliate taste buds made up approximately 11% of TBCs, which represented almost 2 times higher than what was observed in the fungiform and soft palate taste buds. The densities (number of immunoreactive cells per taste bud divided by the maximal cross-sectional area of the taste bud) of types II and III cells per taste bud are significantly higher in the circumvallate papillae than in the other regions. The effects of these region-dependent differences on the taste response of the taste bud are discussed.
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Affiliation(s)
- Takahiro Ogata
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Hibikino 2-4, Kitakyushu-shi, Japan.,ASTEC Co., Ltd, Minamizato 4-6-15, Shime-machi, Kasuya-gun, Fukuoka, Japan
| | - Yoshitaka Ohtubo
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Hibikino 2-4, Kitakyushu-shi, Japan
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27
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Dutt M, Ng YK, Molendijk J, Karimkhanloo H, Liao L, Blazev R, Montgomery MK, Watt MJ, Parker BL. Western Diet Induced Remodelling of the Tongue Proteome. Proteomes 2021; 9:proteomes9020022. [PMID: 34066295 PMCID: PMC8163156 DOI: 10.3390/proteomes9020022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/03/2021] [Accepted: 05/08/2021] [Indexed: 12/14/2022] Open
Abstract
The tongue is a heavily innervated and vascularized striated muscle that plays an important role in vocalization, swallowing and digestion. The surface of the tongue is lined with papillae which contain gustatory cells expressing various taste receptors. There is growing evidence to suggest that our perceptions of taste and food preference are remodelled following chronic consumption of Western diets rich in carbohydrate and fats. Our sensitivity to taste and also to metabolising Western diets may be a key factor in the rising prevalence of obesity; however, a systems-wide analysis of the tongue is lacking. Here, we defined the proteomic landscape of the mouse tongue and quantified changes following chronic consumption of a chow or Western diet enriched in lipid, fructose and cholesterol for 7 months. We observed a dramatic remodelling of the tongue proteome including proteins that regulate fatty acid and mitochondrial metabolism. Furthermore, the expressions of several receptors, metabolic enzymes and hormones were differentially regulated, and are likely to provide novel therapeutic targets to alter taste perception and food preference to combat obesity.
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28
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Ohtubo Y. Slow recovery from the inactivation of voltage-gated sodium channel Nav1.3 in mouse taste receptor cells. Pflugers Arch 2021; 473:953-968. [PMID: 33881614 DOI: 10.1007/s00424-021-02563-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 02/06/2023]
Abstract
Action potentials play an important role in neurotransmitter release in response to taste. Here, I have investigated voltage-gated Na+ channels, a primary component of action potentials, in respective cell types of mouse fungiform taste bud cells (TBCs) with in situ whole-cell clamping and single-cell RT-PCR techniques. The cell types of TBCs electrophysiologically examined were determined immunohistochemically using the type III inositol 1,4,5-triphoshate receptor as a type II cell marker and synaptosomal-associated protein 25 as a type III cell marker. I show that type II cells, type III cells, and TBCs not immunoreactive to these markers (likely type I cells) generate voltage-gated Na+ currents. The recovery following inactivation of these currents was well fitted with double exponential curves. The time constants in type III cells (~20 ms and ~ 1 s) were significantly slower than respective time constants in other cell types. RT-PCR analysis indicated the expression of Nav1.3, Nav1.5, Nav1.6, and β1 subunit mRNAs in TBCs. Pharmacological inhibition and single-cell RT-PCR studies demonstrated that type II and type III cells principally express tetrodotoxin (TTX)-sensitive Nav1.3 channels and that ~ 30% of type I cells express TTX-resistant Nav1.5 channels. The auxiliary β1 subunit that modulates gating kinetics was rarely detected in TBCs. As the β1 subunit co-expressed with an α subunit is known to accelerate the recovery from inactivation, it is likely that voltage-gated Na+ channels in TBCs may function without β subunits. Slow recovery from inactivation, especially in type III cells, may limit high-frequency firing in response to taste substances.
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Affiliation(s)
- Yoshitaka Ohtubo
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Hibikino 2-4, Kitakyushu, 808-0196, Japan.
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29
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Gaillard D, Barlow LA. A Mechanistic Overview of Taste Bud Maintenance and Impairment in Cancer Therapies. Chem Senses 2021; 46:6161548. [PMID: 33693542 DOI: 10.1093/chemse/bjab011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Since the early 20th century, progress in cancer therapies has significantly improved disease prognosis. Nonetheless, cancer treatments are often associated with side effects that can negatively affect patient well-being and disrupt the course of treatment. Among the main side effects, taste impairment is associated with depression, malnutrition, and morbid weight loss. Although relatively common, taste disruption associated with cancer therapies remains poorly understood. Here, we review the current knowledge related to the molecular mechanisms underlying taste maintenance and disruption in the context of cancer therapies.
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Affiliation(s)
- Dany Gaillard
- Department of Cell & Developmental Biology, and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, 12801 East 17th Avenue, Mail Stop 8108, Aurora, CO 80045, USA
| | - Linda A Barlow
- Department of Cell & Developmental Biology, and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, 12801 East 17th Avenue, Mail Stop 8108, Aurora, CO 80045, USA
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Piochi M, Dinnella C, Spinelli S, Monteleone E, Torri L. Individual differences in responsiveness to oral sensations and odours with chemesthetic activity: Relationships between sensory modalities and impact on the hedonic response. Food Qual Prefer 2021. [DOI: 10.1016/j.foodqual.2020.104112] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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31
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Chamoun E, Liu AS, Duizer LM, Feng Z, Darlington G, Duncan AM, Haines J, Ma DWL. Single nucleotide polymorphisms in sweet, fat, umami, salt, bitter and sour taste receptor genes are associated with gustatory function and taste preferences in young adults. Nutr Res 2021; 85:40-46. [PMID: 33444969 DOI: 10.1016/j.nutres.2020.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/18/2020] [Accepted: 12/01/2020] [Indexed: 01/13/2023]
Abstract
Taste is a fundamental mechanism whereby compounds are detected orally, yet it is highly variable among individuals. The variability in taste that is attributable to genetics is not well-characterized despite its potential role in food selection, and therefore, eating habits that contribute to risk of overweight and obesity. In order to implicate measures of taste function and preference as potentially deterministic factors in adverse eating behaviors that lead to obesity, it must be shown that a relationship exists between genetic variation in taste receptor genes and psychophysical measures of taste in the absence high body mass index. The primary objective of this pilot study was to investigate the relationship between single nucleotide polymorphisms (SNPs) in taste receptor genes and 3 different psychophysical measures of taste in healthy young adults. Sweet, salt, umami, fat, sour, and bitter taste receptor gene SNPs were genotyped in 49 participants (ages 24.6 ± 0.6 years) who completed testing to determine oral detection threshold (DT), suprathreshold sensitivity (ST) and taste preference (PR). A simultaneous association test was conducted between each SNP and the 3 taste outcomes (DT, ST, and PR). Twelve SNPs were associated with at least one of the 3 taste outcomes. Associations were observed between SNPs in taste receptor genes and psychophysical measures of sweet, fat, umami, and salt taste. These results suggest that differences in interindividual psychophysical measures of tastes, namely DT, ST, and PR, may be partially attributed to genetic variation in taste receptor genes. Future studies are warranted to investigate if these findings have consequences for habitual dietary intake of foods that elicit these tastes.
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Affiliation(s)
- Elie Chamoun
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - Angel S Liu
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - Lisa M Duizer
- Department of Food Science, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - Zeny Feng
- Department of Mathematics and Statistics, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - Gerarda Darlington
- Department of Mathematics and Statistics, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - Alison M Duncan
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - Jess Haines
- Department of Family Relations and Applied Nutrition, University of Guelph, Guelph, ON, Canada, N1G2W1
| | - David W L Ma
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada, N1G2W1.
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32
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Abstract
Sour taste, which is evoked by low pH, is one of the original four fundamental taste qualities, recognized as a distinct taste sensation for centuries, and universally aversive across diverse species. It is generally assumed to have evolved for detection of acids in unripe fruit and spoiled food. But despite decades of study, only recently have the receptor, the neurotransmitter, and the circuits for sour taste been identified. In this review, we describe studies leading up to the identification of the sour receptor as OTOP1, an ion channel that is selectively permeable to protons. We also describe advances in our understanding of how information is transmitted from the taste receptor cells to gustatory neurons, leading to behavioral aversion to acids.
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Affiliation(s)
- Emily R Liman
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, 3641 Watt Way, Los Angeles, CA 90089, USA
| | - Sue C Kinnamon
- Department of Otolaryngology and Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, 12700 E 19(th) Avenue, Aurora, CO 80045, USA
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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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34
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Takeuchi K, Yoshii K, Ohtubo Y. Age-related electrophysiological changes in mouse taste receptor cells. Exp Physiol 2020; 106:519-531. [PMID: 33174320 DOI: 10.1113/ep089104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/09/2020] [Indexed: 12/14/2022]
Abstract
NEW FINDINGS What is the central question of this study? Loss of taste or inability to distinguish between different tastes progresses with age. The purpose was to evaluate the age-dependent changes in taste by studying the electrophysiological properties of taste receptor cells. What is the main finding and its importance? Ageing decreased the voltage-gated Na+ and K+ current densities of type III cells (sour and/or salt receptor cells) but did not affect the current densities in type II cells. At the peripheral levels, the excitability of type III cells was reduced due to ageing, which may affect the signal transduction to taste nerves. ABSTRACT The loss of taste due to normal ageing in mammals is assumed to be caused by the ageing of taste receptor cells. We examined the electrophysiological properties of taste receptor cells in the fungiform taste buds of ∼20-month-old mice in situ and subsequently identified their cell types with immunological markers: the inositol 1,4,5-trisphosphate (IP3 ) receptor (IP3 R3) for type II cells and a SNARE protein, synaptosomal-associated protein 25 (SNAP-25), for type III cells. Other cells are referred to as non-immunoreactive cells (non-IRCs). Cell types of some cells that could not be identified using cell-type markers were identified based on the electrophysiological feature of the respective cell types. All cell types generated action potentials and a variety of voltage-gated currents. The type II cells mainly expressed tetraethylammonium (TEA)-insensitive and slowly activating outwardly rectifying currents and generated tail currents in repolarization. In contrast, the type III cells expressed TEA-sensitive and faster activating K+ currents and did not generate tail currents. These cell type-specific characteristics of voltage-gated currents in ∼20-month-old mice were similar to their respective cell types in ∼2-month-old mice. Also, we showed an age-dependent decrease in Na+ and K+ current densities in type III cells and an age-dependent increase in outwardly rectifying current density in non-IRCs. Ageing did not affect the voltage-gated current densities in type II cells. The decreased Na+ and K+ current densities, i.e. the decreased excitability of type III cells, due to ageing may affect the signal transduction to taste nerves.
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Affiliation(s)
- Keita Takeuchi
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu-shi, Japan
| | - Kiyonori Yoshii
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu-shi, Japan
| | - Yoshitaka Ohtubo
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu-shi, Japan
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35
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Crosson SM, Marques A, Dib P, Dotson CD, Munger SD, Zolotukhin S. Taste Receptor Cells in Mice Express Receptors for the Hormone Adiponectin. Chem Senses 2020; 44:409-422. [PMID: 31125082 DOI: 10.1093/chemse/bjz030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The metabolic hormone adiponectin is secreted into the circulation by adipocytes and mediates key biological functions, including insulin sensitivity, adipocyte development, and fatty acid oxidation. Adiponectin is also abundant in saliva, where its functions are poorly understood. Here we report that murine taste receptor cells (TRCs) express specific adiponectin receptors and may be a target for salivary adiponectin. This is supported by the presence of all three known adiponectin receptors in transcriptomic data obtained by RNA-seq analysis of purified circumvallate (CV) taste buds. As well, immunohistochemical analysis of murine CV papillae showed that two adiponectin receptors, ADIPOR1 and T-cadherin, are localized to subsets of TRCs. Immunofluorescence for T-cadherin was primarily co-localized with the Type 2 TRC marker phospholipase C β2, suggesting that adiponectin signaling could impact sweet, bitter, or umami taste signaling. However, adiponectin null mice showed no differences in behavioral lick responsiveness compared with wild-type controls in brief-access lick testing. AAV-mediated overexpression of adiponectin in the salivary glands of adiponectin null mice did result in a small but significant increase in behavioral lick responsiveness to the fat emulsion Intralipid. Together, these results suggest that salivary adiponectin can affect TRC function, although its impact on taste responsiveness and peripheral taste coding remains unclear.
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Affiliation(s)
- Sean M Crosson
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida, Gainesville, FL, USA.,Center for Smell and Taste, University of Florida, Gainesville, FL, USA.,Graduate Program in Biomedical Sciences, University of Florida, Gainesville, FL, USA
| | - Andrew Marques
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida, Gainesville, FL, USA
| | - Peter Dib
- Graduate Program in Biomedical Sciences, University of Florida, Gainesville, FL, USA.,Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL, USA
| | - Cedrick D Dotson
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Steven D Munger
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA.,Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.,Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism; University of Florida, Gainesville, FL, USA
| | - Sergei Zolotukhin
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida, Gainesville, FL, USA.,Center for Smell and Taste, University of Florida, Gainesville, FL, USA
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36
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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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37
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Zhang N, Wei X, Fan Y, Zhou X, Liu Y. Recent advances in development of biosensors for taste-related analyses. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.115925] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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38
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Melis M, Sollai G, Mastinu M, Pani D, Cosseddu P, Bonfiglio A, Crnjar R, Tepper BJ, Tomassini Barbarossa I. Electrophysiological Responses from the Human Tongue to the Six Taste Qualities and Their Relationships with PROP Taster Status. Nutrients 2020; 12:E2017. [PMID: 32645975 PMCID: PMC7400817 DOI: 10.3390/nu12072017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 02/07/2023] Open
Abstract
Taste buds containing receptor cells that primarily detect one taste quality provide the basis for discrimination across taste qualities. The molecular receptor multiplicity and the interactions occurring between bud cells encode information about the chemical identity, nutritional value, and potential toxicity of stimuli before transmitting signals to the hindbrain. PROP (6-n-propylthiouracil) tasting is widely considered a marker for individual variations of taste perception, dietary preferences, and health. However, controversial data have been reported. We present measures of the peripheral gustatory system activation in response to taste qualities by electrophysiological recordings from the tongue of 39 subjects classified for PROP taster status. The waveform of the potential variation evoked depended on the taste quality of the stimulus. Direct relationships between PROP sensitivity and electrophysiological responses to taste qualities were found. The largest and fastest responses were recorded in PROP super-tasters, who had the highest papilla density, whilst smaller and slower responses were found in medium tasters and non-tasters with lower papilla densities. The intensities perceived by subjects of the three taster groups correspond to their electrophysiological responses for all stimuli except NaCl. Our results show that each taste quality can generate its own electrophysiological fingerprint on the tongue and provide direct evidence of the relationship between general taste perception and PROP phenotype.
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Affiliation(s)
- Melania Melis
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, CA, Italy; (G.S.); (M.M.); (R.C.)
| | - Giorgia Sollai
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, CA, Italy; (G.S.); (M.M.); (R.C.)
| | - Mariano Mastinu
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, CA, Italy; (G.S.); (M.M.); (R.C.)
| | - Danilo Pani
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, I 09123 Cagliari, CA, Italy; (D.P.); (P.C.); (A.B.)
| | - Piero Cosseddu
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, I 09123 Cagliari, CA, Italy; (D.P.); (P.C.); (A.B.)
| | - Annalisa Bonfiglio
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, I 09123 Cagliari, CA, Italy; (D.P.); (P.C.); (A.B.)
| | - Roberto Crnjar
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, CA, Italy; (G.S.); (M.M.); (R.C.)
| | - Beverly J. Tepper
- Department of Food Science, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901-8520, USA;
| | - Iole Tomassini Barbarossa
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, CA, Italy; (G.S.); (M.M.); (R.C.)
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39
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Nakao Y, Koshimura M, Yamasaki T, Ohtubo Y. Cell-type-independent expression of inwardly rectifying potassium currents in mouse fungiform taste bud cells. Physiol Res 2020; 69:501-510. [PMID: 32469236 DOI: 10.33549/physiolres.934331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Inwardly rectifying potassium (Kir) channels play key roles in functions, including maintaining the resting membrane potential and regulating the action potential duration in excitable cells. Using in situ whole-cell recordings, we investigated Kir currents in mouse fungiform taste bud cells (TBCs) and immunologically identified the cell types (type I-III) expressing these currents. We demonstrated that Kir currents occur in a cell-type-independent manner. The activation potentials we measured were -80 to -90 mV, and the magnitude of the currents increased as the membrane potentials decreased, irrespective of the cell types. The maximum current densities at -120 mV showed no significant differences among cell types (p>0.05, one-way ANOVA). The density of Kir currents was not correlated with the density of either transient inward currents or outwardly rectifying currents, although there was significant correlation between transient inward and outwardly rectifying current densities (p<0.05, test for no correlation). RT-PCR studies employing total RNA extracted from peeled lingual epithelia detected mRNAs for Kir1, Kir2, Kir4, Kir6, and Kir7 families. These findings indicate that TBCs express several types of Kir channels functionally, which may contribute to regulation of the resting membrane potential and signal transduction of taste.
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Affiliation(s)
- Y Nakao
- Department of Human Intelligence Systems, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan.
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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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Function, Innervation, and Neurotransmitter Signaling in Mice Lacking Type-II Taste Cells. eNeuro 2020; 7:ENEURO.0339-19.2020. [PMID: 31988217 PMCID: PMC7004487 DOI: 10.1523/eneuro.0339-19.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 01/08/2023] Open
Abstract
The Skn-1a transcription factor (Pou2f3) is required for Type II taste cell differentiation in taste buds. Taste buds in Skn-1a-/- mice lack Type II taste cells but have a concomitant expansion of Type III cells, providing an ideal model to determine the relative role of taste cell types in response specificity. We confirmed that chorda tympani responses to sweet, bitter, and umami stimuli were greatly reduced in the knock-outs (KOs) compared with wild-type (WT) littermates. Skn-1a-/- mice also had reductions to NaCl that were partially amiloride-insensitive, suggesting that both Type II and Type III cells contribute to amiloride-insensitive salt detection in anterior tongue. We also confirmed that responses to sour stimuli are equivalent in the KOs, despite the large increase in the number of Type III taste cells. To examine their innervation, we crossed the Htr3a-GFP (5-HT3A-GFP) reporter mouse with the Skn-1a-/- mice and examined geniculate ganglion neurons for GFP expression and responses to 5-HT. We found no change in the number of 5-HT3A-expressing neurons with KO of Skn-1a. Calcium imaging showed that only 5-HT3A-expressing neurons respond to exogenous 5-HT, while most neurons respond to ATP, similar to WT mice. Interestingly, despite loss of all Type II cells, the P2X3 antagonist AF353 blocked all chorda tympani responses. These data collectively raise questions pertaining the source of ATP signaling in the absence of Type II taste cells and whether the additional Type III cells are innervated by fibers that would have normally innervated Type II cells.
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Abstract
The Skn-1a transcription factor (Pou2f3) is required for Type II taste cell differentiation in taste buds. Taste buds in Skn-1a -/- mice lack Type II taste cells but have a concomitant expansion of Type III cells, providing an ideal model to determine the relative role of taste cell types in response specificity. We confirmed that chorda tympani responses to sweet, bitter, and umami stimuli were greatly reduced in the knock-outs (KOs) compared with wild-type (WT) littermates. Skn-1a -/- mice also had reductions to NaCl that were partially amiloride-insensitive, suggesting that both Type II and Type III cells contribute to amiloride-insensitive salt detection in anterior tongue. We also confirmed that responses to sour stimuli are equivalent in the KOs, despite the large increase in the number of Type III taste cells. To examine their innervation, we crossed the Htr3a-GFP (5-HT3A-GFP) reporter mouse with the Skn-1a -/- mice and examined geniculate ganglion neurons for GFP expression and responses to 5-HT. We found no change in the number of 5-HT3A-expressing neurons with KO of Skn-1a Calcium imaging showed that only 5-HT3A-expressing neurons respond to exogenous 5-HT, while most neurons respond to ATP, similar to WT mice. Interestingly, despite loss of all Type II cells, the P2X3 antagonist AF353 blocked all chorda tympani responses. These data collectively raise questions pertaining the source of ATP signaling in the absence of Type II taste cells and whether the additional Type III cells are innervated by fibers that would have normally innervated Type II cells.
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Iwamoto M, Takashima M, Ohtubo Y. A subset of taste receptor cells express biocytin-permeable channels activated by reducing extracellular Ca 2+ concentration. Eur J Neurosci 2020; 51:1605-1623. [PMID: 31912931 DOI: 10.1111/ejn.14672] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 12/03/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
Abstract
Taste receptor cells (type II cells) transmit taste information to taste nerve fibres via ATP-permeable channels, including calcium homeostasis modulator (CALHM), connexin and/or pannexin1 channels, via the paracrine release of adenosine triphosphate (ATP) as a predominant transmitter. In the present study, we demonstrate that extracellular Ca2+ -dependent biocytin-permeable channels are present in a subset of type II cells in mouse fungiform taste buds using biocytin uptake, immunohistochemistry and in situ whole-cell recordings. Type II cells were labelled with biocytin in an extracellular Ca2+ concentration ([Ca2+ ]out )-sensitive manner. We found that the ratio of biocytin-labelled type II cells to type II cells per taste bud was approximately 20% in 2 mM Ca2+ saline, and this ratio increased to approximately 50% in nominally Ca2+ -free saline. The addition of 300 µM GdCl3 , which inhibits various channels including CALHM1 channels, significantly inhibited biocytin labelling in nominally Ca2+ -free saline, whereas the addition of 20 µM ruthenium red did not. Moreover, Cs+ -insensitive currents increased in nominally Ca2+ -free saline in approximately 40% of type II cells. These increased currents appeared at a potential of above -35 mV, reversed at approximately +10 mV and increased with depolarization. These results suggest that biocytin labels type II cells via ion channels activated by [Ca2+ ]out reduction, probably "CALHM-like" channels, on the basolateral membrane and that taste receptor cells can be categorized into two groups based on differences in the expression levels of [Ca2+ ]out -dependent biocytin-permeable channels. These data indicate electrophysiological and pharmacologically relevant properties of biocytin-permeable channels and suggest their contributions to taste signal transduction.
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Affiliation(s)
- Masafumi Iwamoto
- Graduate school of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu-shi, Japan
| | - Madoka Takashima
- Graduate school of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu-shi, Japan
| | - Yoshitaka Ohtubo
- Graduate school of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu-shi, Japan
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Qiu Z, Zheng Z, Zhang B, Sun-Waterhouse D, Qiao X. Formation, nutritional value, and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans. Compr Rev Food Sci Food Saf 2020; 19:801-834. [PMID: 33325167 DOI: 10.1111/1541-4337.12529] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/28/2019] [Accepted: 12/11/2019] [Indexed: 12/30/2022]
Abstract
Black garlic (BG) is essentially a processed food and obtained through the transformation of fresh garlic (FG) (Allium sativum L.) via a range of chemical reactions (including the Maillard reaction) and microbial fermentation. This review provides the up-to-date knowledge of the dynamic and complicated changes in major components during the conversion of FG to BG, including moisture, lipids, carbohydrates (such as sugars), proteins, organic acids, organic sulfur compounds, alkaloids, polyphenols, melanoidins, 5-hydroxymethylfurfural, vitamins, minerals, enzymes, and garlic endophytes. The obtained evidence confirms that BG has several advantages over FG in certain product attributes and biological properties (especially antioxidant activity), and the factors affecting the quality of BG include the type and characteristics of FG and processing technologies and methods (especially pretreatments, and processing temperature and humidity). The interactions among garlic components, and between garlic nutrients and microbes, as well as the interplay between pretreatment and main manufacturing process, all determine the sensory and nutritional qualities of BG. Before BG is marketed as a novel snack or functional food, more research is required to fill the knowledge gaps related to quantitative monitoring of the changes in metabolites (especially those taste-active and/or biological-active substances) during BG manufacturing to maximize BG's antioxidant, anticancer, antiobesity, anti-inflammatory, immunostimulatory, anti-allergic, hepatoprotective, cardioprotective and oxidative stress-/hangover syndrome-reducing functions, and beneficial effects on memory/nervous systems. Assessments of the quality, efficacy, and safety of BG should be performed considering the impacts of BG production conditions, postproduction handling, and intake methods.
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Affiliation(s)
- Zhichang Qiu
- Key Laboratory of Food Processing Technology and Quality Control of Shandong Higher Education Institutes, The College of Food Science and Engineering, Shandong Agricultural University, Shandong, P. R. China
| | - Zhenjia Zheng
- Key Laboratory of Food Processing Technology and Quality Control of Shandong Higher Education Institutes, The College of Food Science and Engineering, Shandong Agricultural University, Shandong, P. R. China
| | - Bin Zhang
- Key Laboratory of Food Processing Technology and Quality Control of Shandong Higher Education Institutes, The College of Food Science and Engineering, Shandong Agricultural University, Shandong, P. R. China
| | - Dongxiao Sun-Waterhouse
- Key Laboratory of Food Processing Technology and Quality Control of Shandong Higher Education Institutes, The College of Food Science and Engineering, Shandong Agricultural University, Shandong, P. R. China.,The School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
| | - Xuguang Qiao
- Key Laboratory of Food Processing Technology and Quality Control of Shandong Higher Education Institutes, The College of Food Science and Engineering, Shandong Agricultural University, Shandong, P. R. China
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The c-kit Receptor Tyrosine Kinase Marks Sweet or Umami Sensing T1R3 Positive Adult Taste Cells in Mice. CHEMOSENS PERCEPT 2020. [DOI: 10.1007/s12078-019-09277-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Gaillard D, Shechtman LA, Millar SE, Barlow LA. Fractionated head and neck irradiation impacts taste progenitors, differentiated taste cells, and Wnt/β-catenin signaling in adult mice. Sci Rep 2019; 9:17934. [PMID: 31784592 PMCID: PMC6884601 DOI: 10.1038/s41598-019-54216-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/10/2019] [Indexed: 12/13/2022] Open
Abstract
Head and neck cancer patients receiving conventional repeated, low dose radiotherapy (fractionated IR) suffer from taste dysfunction that can persist for months and often years after treatment. To understand the mechanisms underlying functional taste loss, we established a fractionated IR mouse model to characterize how taste buds are affected. Following fractionated IR, we found as in our previous study using single dose IR, taste progenitor proliferation was reduced and progenitor cell number declined, leading to interruption in the supply of new taste receptor cells to taste buds. However, in contrast to a single dose of IR, we did not encounter increased progenitor cell death in response to fractionated IR. Instead, fractionated IR induced death of cells within taste buds. Overall, taste buds were smaller and fewer following fractionated IR, and contained fewer differentiated cells. In response to fractionated IR, expression of Wnt pathway genes, Ctnnb1, Tcf7, Lef1 and Lgr5 were reduced concomitantly with reduced progenitor proliferation. However, recovery of Wnt signaling post-IR lagged behind proliferative recovery. Overall, our data suggest carefully timed, local activation of Wnt/β-catenin signaling may mitigate radiation injury and/or speed recovery of taste cell renewal following fractionated IR.
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Affiliation(s)
- Dany Gaillard
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Mail Stop 8108, 12801 East 17th Avenue, Aurora, CO, 80045, USA.
- Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Mail Stop 8108, 12801 East 17th Avenue, Aurora, CO, 80045, USA.
| | - Lauren A Shechtman
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Mail Stop 8108, 12801 East 17th Avenue, Aurora, CO, 80045, USA
- Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Mail Stop 8108, 12801 East 17th Avenue, Aurora, CO, 80045, USA
| | - Sarah E Millar
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Linda A Barlow
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Mail Stop 8108, 12801 East 17th Avenue, Aurora, CO, 80045, USA.
- Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Mail Stop 8108, 12801 East 17th Avenue, Aurora, CO, 80045, USA.
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Hassan R, Rabea AA, Ragae A, Sabry D. The prospective role of mesenchymal stem cells exosomes on circumvallate taste buds in induced Alzheimer's disease of ovariectomized albino rats: (Light and transmission electron microscopic study). Arch Oral Biol 2019; 110:104596. [PMID: 31734542 DOI: 10.1016/j.archoralbio.2019.104596] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/17/2019] [Accepted: 10/25/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To elucidate the effect of Alzheimer's disease on the structure of circumvallate papilla taste buds and the possible role of exosomes on the taste buds in Alzheimer's disease. DESIGN Forty two ovariectomized female adult albino rats were utilized and divided into: Group I: received vehicle. Group II: received aluminum chloride to induce Alzheimer's disease. Group III: after the induction of Alzheimer's disease, each rat received single dose of exosomes then left for 4 weeks. The circumvallate papillae were prepared for examination by light and transmission electron microscope. STATISTICAL ANALYSIS histomorphometric data were statistically analyzed. RESULTS Histological examination of circumvallate papilla in Group I showed normal histological features. Group II revealed distorted features. Group III illustrated nearly normal histological features of circumvallate. Silver impregnation results showed apparently great number of heavily impregnated glossopharyngeal nerve fibers in both Groups I & III but markedly decreased in Group II. Synaptophysin-immunoreactivity was strong in Group I, mild in Group II and moderate in Group III. The ultra-structural examination of taste bud cells revealed normal features in Group I, distorted features in Group II and almost normal features in Group III. Statistically highest mean of Synaptophysin-immunoreactivity area% was for Group I, followed by Group III, and the least value was for Group II. CONCLUSIONS Alzheimer's disease has degenerative effects. Bone marrow mesenchymal stem cell (BM-MSC)-derived exosomes have the ability to improve the destructive changes induced by Alzheimer's disease.
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Affiliation(s)
- Rabab Hassan
- Lecturer of Oral Biology, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | - Amany A Rabea
- Associate Professor of Oral Biology, Faculty of Oral and Dental Medicine, Future University in Egypt, Cairo, Egypt.
| | - Alyaa Ragae
- Professor of General Histology, Faculty of Oral and Dental Medicine, Future University in Egypt, Cairo, Egypt
| | - Dina Sabry
- Professor of Medical biochemistry and Molecular Biology, Faculty of Medicine, Cairo University, Cairo, Egypt
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Huang AY. Immune Responses Alter Taste Perceptions: Immunomodulatory Drugs Shape Taste Signals during Treatments. J Pharmacol Exp Ther 2019; 371:684-691. [PMID: 31611237 DOI: 10.1124/jpet.119.261297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/08/2019] [Indexed: 01/01/2023] Open
Abstract
Considering that nutrients are required in health and diseases, the detection and ingestion of food to meet the requirements is attributable to the sense of taste. Altered taste sensations lead to a decreased appetite, which is usually one of the frequent causes of malnutrition in patients with diseases. Ongoing taste research has identified a variety of drug pathways that cause changes in taste perceptions in cancer, increasing our understanding of taste disturbances attributable to aberrant mechanisms of taste sensation. The evidence discussed in this review, which addresses the implications of innate immune responses in the modulation of taste functions, focuses on the adverse effects on taste transmission from taste buds by immune modulators responsible for alterations in the perceived intensity of some taste modalities. Another factor, damage to taste progenitor cells that directly results in local effects on taste buds, must also be considered in relation to taste disturbances in patients with cancer. Recent discoveries discussed have provided new insights into the pathophysiology of taste dysfunctions associated with the specific treatments. SIGNIFICANCE STATEMENT: The paradigm that taste signals transmitted to the brain are determined only by tastant-mediated activation via taste receptors has been challenged by the immune modification of taste transmission through drugs during the processing of gustatory information in taste buds. This article reports the findings in a model system (mouse taste buds) that explain the basis for the taste dysfunctions in patients with cancer that has long been observed but never understood.
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Affiliation(s)
- Anthony Y Huang
- Department of Anatomy and Center for Integrated Research in Cognitive and Neural Science, Southern Illinois University School of Medicine, Carbondale, Illinois
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Cellular and Neural Responses to Sour Stimuli Require the Proton Channel Otop1. Curr Biol 2019; 29:3647-3656.e5. [PMID: 31543453 DOI: 10.1016/j.cub.2019.08.077] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/08/2019] [Accepted: 08/30/2019] [Indexed: 11/24/2022]
Abstract
The sense of taste allows animals to sample chemicals in the environment prior to ingestion. Of the five basic tastes, sour, the taste of acids, had remained among the most mysterious. Acids are detected by type III taste receptor cells (TRCs), located in taste buds across the tongue and palate epithelium. The first step in sour taste transduction is believed to be entry of protons into the cell cytosol, which leads to cytosolic acidification and the generation of action potentials. The proton-selective ion channel Otop1 is expressed in type III TRCs and is a candidate sour receptor. Here, we tested the contribution of Otop1 to taste cell and gustatory nerve responses to acids in mice in which Otop1 was genetically inactivated (Otop1-KO mice). We first show that Otop1 is required for the inward proton current in type III TRCs from different parts of the tongue that are otherwise molecularly heterogeneous. We next show that in type III TRCs from Otop1-KO mice, intracellular pH does not track with extracellular pH and that moderately acidic stimuli do not elicit trains of action potentials, as they do in type III TRCs from wild-type mice. Moreover, gustatory nerve responses in Otop1-KO mice were severely and selectively attenuated for acidic stimuli, including citric acid and HCl. These results establish that the Otop1 proton channel plays a critical role in acid detection in the mouse gustatory system, evidence that it is a bona fide sour taste receptor.
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Abstract
How taste buds detect NaCl remains poorly understood. Among other problems, applying taste-relevant concentrations of NaCl (50-500 mm) onto isolated taste buds or cells exposes them to unphysiological (hypo/hypertonic) conditions. To overcome these limitations, we used the anterior tongue of male and female mice to implement a slice preparation in which fungiform taste buds are in a relatively intact tissue environment and stimuli are limited to the taste pore. Taste-evoked responses were monitored using confocal Ca2+ imaging via GCaMP3 expressed in Type 2 and Type 3 taste bud cells. NaCl evoked intracellular mobilization of Ca2+ in the apical tips of a subset of taste cells. The concentration dependence and rapid adaptation of NaCl-evoked cellular responses closely resembled behavioral and afferent nerve responses to NaCl. Importantly, taste cell responses were not inhibited by the diuretic, amiloride. Post hoc immunostaining revealed that >80% of NaCl-responsive taste bud cells were of Type 2. Many NaCl-responsive cells were also sensitive to stimuli that activate Type 2 cells but never to stimuli for Type 3 cells. Ion substitutions revealed that amiloride-insensitive NaCl responses depended on Cl- rather than Na+ Moreover, choline chloride, an established salt taste enhancer, was equally effective a stimulus as sodium chloride. Although the apical transducer for Cl- remains unknown, blocking known chloride channels and cotransporters had little effect on NaCl responses. Together, our data suggest that chloride, an essential nutrient, is a key determinant of taste transduction for amiloride-insensitive salt taste.SIGNIFICANCE STATEMENT Sodium and chloride are essential nutrients and must be regularly consumed to replace excreted NaCl. Thus, understanding salt taste, which informs salt appetite, is important from a fundamental sensory perspective and forms the basis for interventions to replace/reduce excess Na+ consumption. This study examines responses to NaCl in a semi-intact preparation of mouse taste buds. We identify taste cells that respond to NaCl in the presence of amiloride, which is significant because much of human salt taste also is amiloride-insensitive. Further, we demonstrate that Cl-, not Na+, generates these amiloride-insensitive salt taste responses. Intriguingly, choline chloride, a commercial salt taste enhancer, is also a highly effective stimulus for these cells.
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