1
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Tiroch J, Dunkel A, Sterneder S, Zehentner S, Behrens M, Di Pizio A, Ley JP, Lieder B, Somoza V. Human Gingival Fibroblasts as a Novel Cell Model Describing the Association between Bitter Taste Thresholds and Interleukin-6 Release. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:5314-5325. [PMID: 36943188 PMCID: PMC10080686 DOI: 10.1021/acs.jafc.2c06979] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 02/19/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Human gingival fibroblast cells (HGF-1 cells) present an important cell model to investigate the gingiva's response to inflammatory stimuli such as lipopolysaccharides from Porphyromonas gingivalis (Pg-LPS). Recently, we demonstrated trans-resveratrol to repress the Pg-LPS evoked release of the pro-inflammatory cytokine interleukin-6 (IL-6) via involvement of bitter taste sensing receptor TAS2R50 in HGF-1 cells. Since HGF-1 cells express most of the known 25 TAS2Rs, we hypothesized an association between a compound's bitter taste threshold and its repressing effect on the Pg-LPS evoked IL-6 release by HGF-1 cells. To verify our hypothesis, 11 compounds were selected from the chemical bitter space and subjected to the HGF-1 cell assay, spanning a concentration range between 0.1 μM and 50 mM. In the first set of experiments, the specific role of TAS2R50 was excluded by results from structurally diverse TAS2R agonists and antagonists and by means of a molecular docking approach. In the second set of experiments, the HGF-1 cell response was used to establish a linear association between a compound's effective concentration to repress the Pg-LPS evoked IL-6 release by 25% and its bitter taste threshold concentration published in the literature. The Pearson correlation coefficient revealed for this linear association was R2 = 0.60 (p < 0.01), exceeding respective data for the test compounds from a well-established native cell model, the HGT-1 cells, with R2 = 0.153 (p = 0.263). In conclusion, we provide a predictive model for bitter tasting compounds with a potential to act as anti-inflammatory substances.
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Affiliation(s)
- Johanna Tiroch
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Andreas Dunkel
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | - Sonja Sterneder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Sofie Zehentner
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Maik Behrens
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | - Antonella Di Pizio
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | | | - Barbara Lieder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Veronika Somoza
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
- Chair
for Nutritional Systems Biology, Technical
University Munich, Freising 85354, Germany
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2
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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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3
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Delompré T, Belloir C, Martin C, Salles C, Briand L. Detection of Bitterness in Vitamins Is Mediated by the Activation of Bitter Taste Receptors. Nutrients 2022; 14:nu14194141. [PMID: 36235793 PMCID: PMC9571608 DOI: 10.3390/nu14194141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 11/05/2022] Open
Abstract
Vitamins are known to generate bitterness, which may contribute to an off-taste or aftertaste for some nutritional supplements. This negative sensation can lead to a reduction in their consumption. Little is known about the bitter taste threshold and taste sensing system for the bitter taste detection of vitamins. To better understand the mechanisms involved in bitterness perception, we combined taste receptor functional assays and sensory analysis. In humans, bitter taste detection is mediated by 25 G-protein-coupled receptors belonging to the TAS2R family. First, we studied the bitterness of thirteen vitamins using a cellular-based functional taste receptor assay. We found four vitamins that can stimulate one or more TAS2Rs. For each positive molecule-receptor combination, we tested seven increasing concentrations to determine the half-maximal effective concentration (EC50) and the cellular bitter taste threshold. Second, we measured the bitter taste detection threshold for four vitamins that exhibit a strong bitter taste using a combination of ascending series and sensory difference tests. A combination of sensory and biological data can provide useful results that explain the perception of vitamin bitterness and its real contribution to the off-taste of nutritional supplements.
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4
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Sakakibara M, Sumida H, Yanagida K, Miyasato S, Nakamura M, Sato S. Bitter taste receptor T2R38 is expressed on skin-infiltrating lymphocytes and regulates lymphocyte migration. Sci Rep 2022; 12:11790. [PMID: 35821061 PMCID: PMC9276799 DOI: 10.1038/s41598-022-15999-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 07/04/2022] [Indexed: 12/23/2022] Open
Abstract
Bitter taste receptors (T2Rs) are G protein-coupled receptors involved in the perception of bitter taste on the tongue. In humans, T2Rs have been found in several sites outside the oral cavity. Although T2R38 has been reported to be expressed on peripheral lymphocytes, it is poorly understood whether T2R38 plays immunological roles in inflammatory skin diseases such as atopic dermatitis (AD). Then, we first confirmed that T2R38 gene expression was higher in lesional skin of AD subjects than healthy controls. Furthermore, skin T2R38 expression levels were correlated with serum thymus and activation-regulated chemokine and IgE levels in AD patients. In lesional skin of AD, section staining revealed that CD3+ T cells in the dermis were T2R38 positive. In addition, flow cytometry analysis showed T2R38 expression in skin T cells. Migration assays using T2R38-transduced Jurkat T cell leukemia cells revealed that T2R38 agonists exerted a dose-dependent migration inhibitory effect. Moreover, skin tissue extracts, as well as supernatants of cultured HaCaT keratinocytes, caused T2R38-dependent migration inhibition, indicating that there should be an endogenous ligand for T2R38 in the skin epidermis. These findings implicate T2R38 as a migratory inhibitory receptor on the skin-infiltrating lymphocytes and as a therapeutic target for allergic/inflammatory skin diseases.
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Affiliation(s)
- Moe Sakakibara
- Department of Dermatology, Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Hayakazu Sumida
- Department of Dermatology, Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
| | - Keisuke Yanagida
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan
| | - Sosuke Miyasato
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, Okayama, Japan
| | - Motonao Nakamura
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, Okayama, Japan
| | - Shinichi Sato
- Department of Dermatology, Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
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5
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Abstract
Bitter taste-sensing type 2 receptors (TAS2Rs or T2Rs), belonging to the subgroup of family A G-protein coupled receptors (GPCRs), are of crucial importance in the perception of bitterness. Although in the first instance, TAS2Rs were considered to be exclusively distributed in the apical microvilli of taste bud cells, numerous studies have detected these sensory receptor proteins in several extra-oral tissues, such as in pancreatic or ovarian tissues, as well as in their corresponding malignancies. Critical points of extra-oral TAS2Rs biology, such as their structure, roles, signaling transduction pathways, extensive mutational polymorphism, and molecular evolution, have been currently broadly studied. The TAS2R cascade, for instance, has been recently considered to be a pivotal modulator of a number of (patho)physiological processes, including adipogenesis or carcinogenesis. The latest advances in taste receptor biology further raise the possibility of utilizing TAS2Rs as a therapeutic target or as an informative index to predict treatment responses in various disorders. Thus, the focus of this review is to provide an update on the expression and molecular basis of TAS2Rs functions in distinct extra-oral tissues in health and disease. We shall also discuss the therapeutic potential of novel TAS2Rs targets, which are appealing due to their ligand selectivity, expression pattern, or pharmacological profiles.
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Affiliation(s)
- Kamila Tuzim
- Department of Clinical Pathomorphology, Medical University of Lublin, ul. Jaczewskiego 8b, 20-090, Lublin, Poland.
| | - Agnieszka Korolczuk
- Department of Clinical Pathomorphology, Medical University of Lublin, ul. Jaczewskiego 8b, 20-090, Lublin, Poland
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6
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Okada Y, Yoshimura K, Toya S, Tsuchimochi M. Pathogenesis of taste impairment and salivary dysfunction in COVID-19 patients. JAPANESE DENTAL SCIENCE REVIEW 2021; 57:111-122. [PMID: 34257762 PMCID: PMC8266517 DOI: 10.1016/j.jdsr.2021.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/27/2021] [Accepted: 07/05/2021] [Indexed: 12/23/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19) is a highly transmissible pandemic disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The characteristics of the disease include a broad range of symptoms from mild to serious to death, with mild pneumonia to acute respiratory distress syndrome and complications in extrapulmonary organs. Taste impairment and salivary dysfunction are common early symptoms in COVID-19 patients. The mouth is a significant entry route for SARS-COV-2, similar to the nose and eyes. The cells of the oral epithelium, taste buds, and minor and major salivary glands express cell entry factors for SARS-COV-2, such as ACE2, TMPRSS2, and Furin. We describe the occurrence of taste impairment and salivary dysfunction in COVID-19 patients and show immunohistochemical findings regarding the cell entry factors in the oral tissue. We review and describe the pathogeneses of taste impairment and salivary dysfunction. Treatment for the oral disease is also described. Recently, it was reported that some people experience persistent and prolonged taste impairment and salivary dysfunction, described as post-COVID-19 syndrome or long COVID-19, after the acute illness of the infection has healed. To resolve these problems, it is important to understand the pathogenesis of oral complications. Recently, important advances have been reported in the understanding of gustatory impairment and salivary dysfunction. Although some progress has been made, considerable effort is still required for in-depth elucidation of the pathogenesis.
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Affiliation(s)
- Yasuo Okada
- Department of Pathology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan
| | - Ken Yoshimura
- Department of Anatomy, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan
| | - Shuji Toya
- Oral and Maxillofacial Surgery, The Nippon Dental University Niigata Hospital, 1-8 Hamaura-cho, Chuo-ku, Niigata 951-8580, Japan
| | - Makoto Tsuchimochi
- The Nippon Dental University (Emeritus Professor), 1-9-20 Fujimi, Chiyoda-ku, Tokyo, 102-8159, Japan
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7
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Hayashi M, Inaba A, Hakukawa M, Iwatsuki K, Imai H, Masuda K. Expression of TAS2R14 in the intestinal endocrine cells of non-human primates. Genes Genomics 2021; 43:259-267. [PMID: 33609226 DOI: 10.1007/s13258-021-01054-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Recent studies have demonstrated that genes related to bitter taste receptors (TAS2Rs) on various chromosomes are expressed in extra-oral organs of various animals. The bitter taste receptor TAS2R14 is conserved among primate species and shows broad ligand sensitivity. Mice have a number of orthologues to primate TAS2R14 located in tandem on chromosome 16; however, their expression patterns are not unique. OBJECTIVE We characterized the expression of TAS2R14 in various cell types in the intestines of the rhesus macaque and evaluated its role in hormone production in the gut. METHODS TAS2R14 expression was examined in the intestines of rhesus macaques, a common non-human primate model, by RT-qPCR and immunohistochemical staining. RESULTS Mean expression levels of TAS2R14 in the duodenum, ileum, and colon were similar to each other and were lower than those in circumvallate papillae. An immunohistochemical analysis revealed TAS2R14 immunoreactivity in enteroendocrine cells positive for cholecystokinin, serotonin, and the G protein GNAT3. CONCLUSION These results suggest that primate TAS2R14 is broadly expressed in the intestine, mainly in enteroendocrine cells, and promotes gut hormone secretion in response to bitter stimuli.
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Affiliation(s)
- Misa Hayashi
- Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama, Aichi, 484-8506, Japan
| | - Akihiko Inaba
- Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama, Aichi, 484-8506, Japan
| | - Miho Hakukawa
- Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama, Aichi, 484-8506, Japan
| | - Ken Iwatsuki
- Department of Nutritional Science and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo, 1568502, Japan
| | - Hiroo Imai
- Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama, Aichi, 484-8506, Japan.
| | - Katsuyoshi Masuda
- Structural Bioscience for Taste Molecular Recognition, Graduate School of Medicine, Kyoto University, Kyoto, 6068507, Japan.
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8
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Reed DR, Alhadeff AL, Beauchamp GK, Chaudhari N, Duffy VB, Dus M, Fontanini A, Glendinning JI, Green BG, Joseph PV, Kyriazis GA, Lyte M, Maruvada P, McGann JP, McLaughlin JT, Moran TH, Murphy C, Noble EE, Pepino MY, Pluznick JL, Rother KI, Saez E, Spector AC, Sternini C, Mattes RD. NIH Workshop Report: sensory nutrition and disease. Am J Clin Nutr 2021; 113:232-245. [PMID: 33300030 PMCID: PMC7779223 DOI: 10.1093/ajcn/nqaa302] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022] Open
Abstract
In November 2019, the NIH held the "Sensory Nutrition and Disease" workshop to challenge multidisciplinary researchers working at the interface of sensory science, food science, psychology, neuroscience, nutrition, and health sciences to explore how chemosensation influences dietary choice and health. This report summarizes deliberations of the workshop, as well as follow-up discussion in the wake of the current pandemic. Three topics were addressed: A) the need to optimize human chemosensory testing and assessment, B) the plasticity of chemosensory systems, and C) the interplay of chemosensory signals, cognitive signals, dietary intake, and metabolism. Several ways to advance sensory nutrition research emerged from the workshop: 1) refining methods to measure chemosensation in large cohort studies and validating measures that reflect perception of complex chemosensations relevant to dietary choice; 2) characterizing interindividual differences in chemosensory function and how they affect ingestive behaviors, health, and disease risk; 3) defining circuit-level organization and function that link and interact with gustatory, olfactory, homeostatic, visceral, and cognitive systems; and 4) discovering new ligands for chemosensory receptors (e.g., those produced by the microbiome) and cataloging cell types expressing these receptors. Several of these priorities were made more urgent by the current pandemic because infection with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing coronavirus disease of 2019 has direct short- and perhaps long-term effects on flavor perception. There is increasing evidence of functional interactions between the chemosensory and nutritional sciences. Better characterization of this interface is expected to yield insights to promote health, mitigate disease risk, and guide nutrition policy.
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Affiliation(s)
| | - Amber L Alhadeff
- Monell Chemical Senses Center, Philadelphia, PA, USA
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Nirupa Chaudhari
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
- Program in Neurosciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Valerie B Duffy
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, USA
| | - Monica Dus
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Alfredo Fontanini
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| | - John I Glendinning
- Department of Biology, Barnard College, Columbia University, New York, NY, USA
- Department of Neuroscience and Behavior, Barnard College, Columbia University, New York, NY, USA
| | - Barry G Green
- The John B Pierce Laboratory, New Haven, CT, USA
- Department of Surgery (Otolaryngology), Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Paule V Joseph
- National Institute of Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
- National Institute of Nursing, NIH, Bethesda, MD, USA
| | - George A Kyriazis
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Mark Lyte
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, USA
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
| | - Padma Maruvada
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - John P McGann
- Behavioral and Systems Neuroscience, Department of Psychology, Rutgers University, Piscataway, NJ, USA
| | - John T McLaughlin
- Division of Diabetes, Endocrinology, & Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, United Kingdom
- Department of Gastroenterology, Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | - Timothy H Moran
- Department of Psychiatry & Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Claire Murphy
- Department of Psychology, San Diego State University, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, Athens, GA, USA
| | - M Yanina Pepino
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jennifer L Pluznick
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kristina I Rother
- Intramural Research Program, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Enrique Saez
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Alan C Spector
- Department of Psychology, Florida State University, Tallahassee, FL, USA
- Program in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Catia Sternini
- Digestive Disease Division, Departments of Medicine and Neurobiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Richard D Mattes
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
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9
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Singh S, Halder A, Sinha O, Chakrabarty N, Chatterjee T, Adhikari A, Singh P, Shikha D, Ghosh R, Banerjee A, Das Mahapatra PP, Mandhar A, Bhattacharyya M, Bose S, Ahmed SA, Alharbi A, Hameed AM, Pal SK. Spectroscopic Studies on the Biomolecular Recognition of Toluidine Blue: Key Information Towards Development of a Non-Contact, Non-Invasive Device for Oral Cancer Detection. Front Oncol 2020; 10:529132. [PMID: 33194588 PMCID: PMC7653096 DOI: 10.3389/fonc.2020.529132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 09/28/2020] [Indexed: 11/13/2022] Open
Abstract
Molecular interaction of aromatic dyes with biological macromolecules are important for the development of minimally invasive disease diagnostic biotechnologies. In the present work, we have used Toluidine Blue (TB) as a model dye, which is a well-known staining agent for the diagnosis of oral cancer and have studied the interaction of various biological macromolecules (protein and DNA) with the dye at different pH. Our spectroscopic studies confirm that TB interacts with Human Serum Albumin (HSA), a model protein at very high pH conditions which is very hard to achieve physiologically. On the other hand, TB significantly interacts with the DNA at physiological pH value (7.4). Our molecular studies strengthen the understanding of the Toluidine Blue staining of cancer cells, where the relative ratio of the nucleic acids is higher than the normal intracellular content. We have also developed a non-invasive, non-contact spectroscopic technique to explore the possibility of quantitatively detecting oral cancer by exploiting the interaction of TB with DNA. We have also reported development of a prototype named "Oral-O-Scope" for the detection of Oral cancer and have carried out human studies using the prototype.
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Affiliation(s)
- Soumendra Singh
- Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata, India.,Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | - Animesh Halder
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India.,Department of Applied Optics and Photonics, University of Calcutta, Kolkata, India
| | - Oindrila Sinha
- Department of Life Sciences, Presidency University, Kolkata, India
| | - Nilasha Chakrabarty
- Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | | | - Aniruddha Adhikari
- Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | - Priya Singh
- Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | - Deep Shikha
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | - Ria Ghosh
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | - Amrita Banerjee
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | | | - Amit Mandhar
- Department of MedTech R&D, Webel BCC&I Tech Incubation Center, Ezerx Health Pvt. Ltd., Kolkata, India
| | | | - Surajit Bose
- Department of Dentistry, Bharat Sevashram Sangha Hospital, Kolkata, India.,Department of Oral and Maxillofacial Pathology, KSDJ Dental College and Hospital, Kolkata, India
| | - Saleh A Ahmed
- Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia.,Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt
| | - Ahmed Alharbi
- Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Ahmed M Hameed
- Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Samir Kumar Pal
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India.,Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, India
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10
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Chen J, Larson ED, Anderson CB, Agarwal P, Frank DN, Kinnamon SC, Ramakrishnan VR. Expression of Bitter Taste Receptors and Solitary Chemosensory Cell Markers in the Human Sinonasal Cavity. Chem Senses 2020; 44:483-495. [PMID: 31231752 DOI: 10.1093/chemse/bjz042] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Some bitter taste receptors (TAS2R gene products) are expressed in the human sinonasal cavity and may function to detect airborne irritants. The expression of all 25 human bitter taste receptors and their location within the upper airway is not yet clear. The aim of this study is to characterize the presence and distribution of TAS2R transcripts and solitary chemosensory cells (SCCs) in different locations of the human sinonasal cavity. Biopsies were obtained from human subjects at up to 4 different sinonasal anatomic sites. PCR, microarray, and qRT-PCR were used to examine gene transcript expression. The 25 human bitter taste receptors as well as the sweet/umami receptor subunit, TAS1R3, and canonical taste signaling effectors are expressed in sinonasal tissue. All 25 human bitter taste receptors are expressed in the human upper airway, and expression of these gene products was higher in the ethmoid sinus than nasal cavity locations. Fluorescent in situ hybridization demonstrates that epithelial TRPM5 and TAS2R38 are expressed in a rare cell population compared with multiciliated cells, and at times, consistent with SCC morphology. Secondary analysis of published human sinus single-cell RNAseq data did not uncover TAS2R or canonical taste transduction transcripts in multiciliated cells. These findings indicate that the sinus has higher expression of SCC markers than the nasal cavity in chronic rhinosinusitis patients, comprising a rare cell type. Biopsies obtained from the ethmoid sinus may serve as the best location for study of human upper airway taste receptors and SCCs.
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Affiliation(s)
- Jingguo Chen
- Department of Otolaryngology-Head and Neck Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Department of Otolaryngology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Eric D Larson
- Department of Otolaryngology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, Aurora, CO, USA
| | - Catherine B Anderson
- Department of Otolaryngology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, Aurora, CO, USA
| | | | - Daniel N Frank
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sue C Kinnamon
- Department of Otolaryngology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, Aurora, CO, USA
| | - Vijay R Ramakrishnan
- Department of Otolaryngology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, Aurora, CO, USA
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11
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Imai H, Hakukawa M, Hayashi M, Iwatsuki K, Masuda K. Expression of Bitter Taste Receptors in the Intestinal Cells of Non-Human Primates. Int J Mol Sci 2020; 21:ijms21030902. [PMID: 32019181 PMCID: PMC7037741 DOI: 10.3390/ijms21030902] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 12/24/2022] Open
Abstract
(1) Background: Recent studies have investigated the expression of taste-related genes in the organs of various animals, including humans; however, data for additional taxa are needed to facilitate comparative analyses within and among species. (2) Methods: We investigated the expression of taste-related genes in the intestines of rhesus macaques, the non-human primates most commonly used in experimental models. (3) Results: Based on RNAseq and qRT-PCR, genes encoding bitter taste receptors and the G-protein gustducin were expressed in the gut of rhesus macaques. RNAscope analysis showed that one of the bitter receptors, TAS2R38, was expressed in some cells in the small intestine, and immunohistochemical analysis revealed the presence of T2R38-positive cells in the villi of the intestines. (4) Conclusions: These results suggest that bitter receptors are expressed in the gut of rhesus macaques, supporting the use of macaques as a model for studies of human taste, including gut analyses.
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Affiliation(s)
- Hiroo Imai
- Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Aichi 4848506, Japan; (M.H.); (M.H.)
- Correspondence: (H.I.); (K.M.); Tel.: +81-568-63-0577 (H.I.)
| | - Miho Hakukawa
- Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Aichi 4848506, Japan; (M.H.); (M.H.)
| | - Misa Hayashi
- Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Aichi 4848506, Japan; (M.H.); (M.H.)
| | - Ken Iwatsuki
- Department of Nutritional Science and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 1568502, Japan;
| | - Katsuyoshi Masuda
- Structural Bioscience for Taste Molecular Recognition, Graduate School of Medicine, Kyoto University, Kyoto 6068507, Japan
- Correspondence: (H.I.); (K.M.); Tel.: +81-568-63-0577 (H.I.)
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12
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Douglas JE, Lin C, Mansfield CJ, Arayata CJ, Cowart BJ, Spielman AI, Adappa ND, Palmer JN, Cohen NA, Reed DR. Tissue-Dependent Expression of Bitter Receptor TAS2R38 mRNA. Chem Senses 2019; 44:33-40. [PMID: 30351347 DOI: 10.1093/chemse/bjy066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active forms of this receptor is nearly equal in many human populations, and heterozygotes with 1 copy of the active form and 1 copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this receptor too, including the nasal sinuses, where it contributes to pathogen defense. We, therefore, wondered whether heterozygous people had a similar wide range of TAS2R38 mRNA in sinonasal tissue and whether those with higher TAS2R38 mRNA expression in taste tissue were similarly high expressers in nasal tissue. To that end, we measured gene expression by quantitative PCR in taste and sinonasal tissue and found that expression abundance in one tissue was not related to the other. We confirmed the independence of expression in other tissue pairs expressing TAS2R38 mRNA, such as pancreas and small intestine, using autopsy data from the Genotype-Tissue Expression project (although people with high expression of TAS2R38 mRNA in colon also tended to have higher expression in the small intestine). Thus, taste tissue TAS2R38 mRNA expression among heterozygotes is unlikely to predict expression in other tissues, perhaps reflecting tissue-dependent function, and hence regulation, of this protein.
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Affiliation(s)
- Jennifer E Douglas
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, USA.,Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Cailu Lin
- Monell Chemical Senses Center, Philadelphia, PA, USA
| | | | | | | | - Andrew I Spielman
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Nithin D Adappa
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - James N Palmer
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Noam A Cohen
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, USA.,Monell Chemical Senses Center, Philadelphia, PA, USA.,Philadelphia Veterans Affairs Medical Center Surgical Services, Philadelphia, PA, USA
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13
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Witt M. Anatomy and development of the human taste system. HANDBOOK OF CLINICAL NEUROLOGY 2019; 164:147-171. [DOI: 10.1016/b978-0-444-63855-7.00010-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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14
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The Role of Taste Receptors in Airway Innate Immune Defense. SINUSITIS 2018. [DOI: 10.3390/sinusitis3020006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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15
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Zopun M, Liszt KI, Stoeger V, Behrens M, Redel U, Ley JP, Hans J, Somoza V. Human Sweet Receptor T1R3 is Functional in Human Gastric Parietal Tumor Cells (HGT-1) and Modulates Cyclamate and Acesulfame K-Induced Mechanisms of Gastric Acid Secretion. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:4842-4852. [PMID: 29665689 DOI: 10.1021/acs.jafc.8b00658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The noncaloric sweeteners (NCSs) cyclamate (Cycl) and acesulfame K (AceK) are widely added to foods and beverages. Little is known about their impact on gastric acid secretion (GAS), which is stimulated by dietary protein and bitter-tasting compounds. Since Cycl and AceK have a bitter off taste in addition to their sweet taste, we hypothesized they modulate mechanisms of GAS in human gastric parietal cells (HGT-1). HGT-1 cells were exposed to sweet tastants (50 mM of glucose, d-threonine, Cycl, or AceK) and analyzed for their intracellular pH index (IPX), as an indicator of proton secretion by means of a pH-sensitive dye, and for mRNA levels of GAS-associated genes by RT-qPCR. Since the NCSs act via the sweet taste-sensing receptor T1R2/T1R3, mRNA expression of the corresponding genes was analyzed in addition to immunocytochemical localization of the T1R2 and T1R3 receptor proteins. Exposure of HGT-1 cells to AceK or d-threonine increased the IPX to 0.60 ± 0.05 and 0.80 ± 0.04 ( P ≤ 0.05), respectively, thereby indicating a reduced secretion of protons, whereas Cycl demonstrated the opposite effect with IPX values of -0.69 ± 0.08 ( P ≤ 0.05) compared to controls (IPX = 0). Cotreatment with the T1R3-inhibitor lactisole as well as a TAS1R3 siRNA knock-down approach reduced the impact of Cycl, AceK, and d-thr on proton release ( P ≤ 0.05), whereas cotreatment with 10 mM glucose enhanced the NCS-induced effect ( P ≤ 0.05). Overall, we demonstrated Cycl and AceK as modulators of proton secretion in HGT-1 cells and identified T1R3 as a key element in this response.
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Affiliation(s)
- Muhammet Zopun
- Faculty of Chemistry, Department of Physiological Chemistry , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
| | - Kathrin I Liszt
- Faculty of Chemistry, Christian Doppler Laboratory for Bioactive Aroma Compounds , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
| | - Verena Stoeger
- Faculty of Chemistry, Christian Doppler Laboratory for Bioactive Aroma Compounds , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
| | - Maik Behrens
- Department of Molecular Genetics , German Institute of Human Nutrition Potsdam-Rehbruecke , Arthur-Scheunert-Allee , 114-116 Nuthetal , Germany
| | - Ulrike Redel
- Department of Molecular Genetics , German Institute of Human Nutrition Potsdam-Rehbruecke , Arthur-Scheunert-Allee , 114-116 Nuthetal , Germany
| | - Jakob P Ley
- Symrise AG , Mühlenfeldstraße 1 , 37603 Holzminden , Germany
| | - Joachim Hans
- Symrise AG , Mühlenfeldstraße 1 , 37603 Holzminden , Germany
| | - Veronika Somoza
- Faculty of Chemistry, Department of Physiological Chemistry , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
- Faculty of Chemistry, Christian Doppler Laboratory for Bioactive Aroma Compounds , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
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16
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Expression of the bitter receptor T2R38 in pancreatic cancer: localization in lipid droplets and activation by a bacteria-derived quorum-sensing molecule. Oncotarget 2017; 7:12623-32. [PMID: 26862855 PMCID: PMC4914309 DOI: 10.18632/oncotarget.7206] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 01/24/2016] [Indexed: 01/26/2023] Open
Abstract
T2R38 belongs to the family of bitter receptors and was initially detected in cells of the oral cavity. We now describe expression of T2R38 in tumor cells in patients with pancreatic cancer and in tumor-derived cell lines. T2R38 is localized predominantly intracellular in association with lipid droplets, particularly with the lipid droplet membrane. The receptor can be activated by the bona fide ligand for T2R38, phenylthiourea (PTU), and by N-acetyl-dodecanoyl homoserine (AHL-12), a quorum sensing molecule of Pseudomonas aeruginosa, the latter is the only known natural ligand for T2R38. In response to PTU or AHL-12, key transcription factors are activated including phosphorylation of the MAP kinases p38 and ERK1/2, and upregulation of NFATc1. Moreover, we found increased expression of the multi-drug resistance protein 1 (also known as ABCB1), a transmembrane transporter molecule, participating in shuttling of a plethora of drugs, such as chemotherapeutics or antibiotics. In conclusion, our data indicate a new, additional function of the taste receptor T2R38 beyond sensing ‘bitter’. Moreover, because T2R38 can be stimulated by a bacteria-derived signaling molecule the receptor could link microbiota and cancer.
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17
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Caffeine induces gastric acid secretion via bitter taste signaling in gastric parietal cells. Proc Natl Acad Sci U S A 2017; 114:E6260-E6269. [PMID: 28696284 DOI: 10.1073/pnas.1703728114] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Caffeine, generally known as a stimulant of gastric acid secretion (GAS), is a bitter-tasting compound that activates several taste type 2 bitter receptors (TAS2Rs). TAS2Rs are expressed in the mouth and in several extraoral sites, e.g., in the gastrointestinal tract, in which their functional role still needs to be clarified. We hypothesized that caffeine evokes effects on GAS by activation of oral and gastric TAS2Rs and demonstrate that caffeine, when administered encapsulated, stimulates GAS, whereas oral administration of a caffeine solution delays GAS in healthy human subjects. Correlation analysis of data obtained from ingestion of the caffeine solution revealed an association between the magnitude of the GAS response and the perceived bitterness, suggesting a functional role of oral TAS2Rs in GAS. Expression of TAS2Rs, including cognate TAS2Rs for caffeine, was shown in human gastric epithelial cells of the corpus/fundus and in HGT-1 cells, a model for the study of GAS. In HGT-1 cells, various bitter compounds as well as caffeine stimulated proton secretion, whereby the caffeine-evoked effect was (i) shown to depend on one of its cognate receptor, TAS2R43, and adenylyl cyclase; and (ii) reduced by homoeriodictyol (HED), a known inhibitor of caffeine's bitter taste. This inhibitory effect of HED on caffeine-induced GAS was verified in healthy human subjects. These findings (i) demonstrate that bitter taste receptors in the stomach and the oral cavity are involved in the regulation of GAS and (ii) suggest that bitter tastants and bitter-masking compounds could be potentially useful therapeutics to regulate gastric pH.
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18
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Extraoral Taste Receptor Discovery: New Light on Ayurvedic Pharmacology. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017. [PMID: 28642799 PMCID: PMC5469997 DOI: 10.1155/2017/5435831] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
More and more research studies are revealing unexpectedly important roles of taste for health and pathogenesis of various diseases. Only recently it has been shown that taste receptors have many extraoral locations (e.g., stomach, intestines, liver, pancreas, respiratory system, heart, brain, kidney, urinary bladder, pancreas, adipose tissue, testis, and ovary), being part of a large diffuse chemosensory system. The functional implications of these taste receptors widely dispersed in various organs or tissues shed a new light on several concepts used in ayurvedic pharmacology (dravyaguna vijnana), such as taste (rasa), postdigestive effect (vipaka), qualities (guna), and energetic nature (virya). This review summarizes the significance of extraoral taste receptors and transient receptor potential (TRP) channels for ayurvedic pharmacology, as well as the biological activities of various types of phytochemical tastants from an ayurvedic perspective. The relative importance of taste (rasa), postdigestive effect (vipaka), and energetic nature (virya) as ethnopharmacological descriptors within Ayurveda boundaries will also be discussed.
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19
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Wölfle U, Elsholz FA, Kersten A, Haarhaus B, Schumacher U, Schempp CM. Expression and Functional Activity of the Human Bitter Taste Receptor TAS2R38 in Human Placental Tissues and JEG-3 Cells. Molecules 2016; 21:306. [PMID: 26950109 PMCID: PMC6273027 DOI: 10.3390/molecules21030306] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 02/24/2016] [Accepted: 02/26/2016] [Indexed: 01/01/2023] Open
Abstract
Bitter taste receptors (TAS2Rs) are expressed in mucous epithelial cells of the tongue but also outside the gustatory system in epithelial cells of the colon, stomach and bladder, in the upper respiratory tract, in the cornified squamous epithelium of the skin as well as in airway smooth muscle cells, in the testis and in the brain. In the present work we addressed the question if bitter taste receptors might also be expressed in other epithelial tissues as well. By staining a tissue microarray with 45 tissue spots from healthy human donors with an antibody directed against the best characterized bitter taste receptor TAS2R38, we observed an unexpected strong TAS2R38 expression in the amniotic epithelium, syncytiotrophoblast and decidua cells of the human placenta. To analyze the functionality we first determined the TAS2R38 expression in the placental cell line JEG-3. Stimulation of these cells with diphenidol, a clinically used antiemetic agent that binds TAS2Rs including TAS2R38, demonstrated the functionality of the TAS2Rs by inducing calcium influx. Restriction enzyme based detection of the TAS2R38 gene allele identified JEG-3 cells as PTC (phenylthiocarbamide)-taster cell line. Calcium influx induced by PTC in JEG-3 cells could be inhibited with the recently described TAS2R38 inhibitor probenecid and proved the specificity of the TAS2R38 activation. The expression of TAS2R38 in human placental tissues points to further new functions and hitherto unknown endogenous ligands of TAS2Rs far beyond bitter tasting.
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Affiliation(s)
- Ute Wölfle
- Department of Dermatology, University Medical Center, Freiburg 79104, Germany.
| | - Floriana A Elsholz
- Department of Pharmacology, Biocenter, Goethe-University, Frankfurt 60438, Germany.
| | - Astrid Kersten
- Dermatohistological Laboratory Dr.Laaff, Freiburg 79111, Germany.
| | - Birgit Haarhaus
- Department of Dermatology, University Medical Center, Freiburg 79104, Germany.
| | - Udo Schumacher
- Department of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg 20246, Germany.
| | - Christoph M Schempp
- Department of Dermatology, University Medical Center, Freiburg 79104, Germany.
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20
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Workman AD, Palmer JN, Adappa ND, Cohen NA. The Role of Bitter and Sweet Taste Receptors in Upper Airway Immunity. Curr Allergy Asthma Rep 2016; 15:72. [PMID: 26492878 DOI: 10.1007/s11882-015-0571-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Over the past several years, taste receptors have emerged as key players in the regulation of innate immune defenses in the mammalian respiratory tract. Several cell types in the airway, including ciliated epithelial cells, solitary chemosensory cells, and bronchial smooth muscle cells, all display chemoresponsive properties that utilize taste receptors. A variety of bitter products secreted by microbes are detected with resultant downstream inflammation, increased mucous clearance, antimicrobial peptide secretion, and direct bacterial killing. Genetic variation of bitter taste receptors also appears to play a role in the susceptibility to infection in respiratory disease states, including that of chronic rhinosinusitis. Ongoing taste receptor research may yield new therapeutics that harness innate immune defenses in the respiratory tract and may offer alternatives to antibiotic treatment. The present review discusses taste receptor-protective responses and analyzes the role these receptors play in mediating airway immune function.
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Affiliation(s)
- Alan D Workman
- Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania Medical Center, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA.,Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - James N Palmer
- Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania Medical Center, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA.,Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Nithin D Adappa
- Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania Medical Center, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA.,Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Noam A Cohen
- Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania Medical Center, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA. .,Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA. .,Monell Smell and Taste Center, Philadelphia, PA, USA. .,Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA.
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21
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Latorre R, Huynh J, Mazzoni M, Gupta A, Bonora E, Clavenzani P, Chang L, Mayer EA, De Giorgio R, Sternini C. Expression of the Bitter Taste Receptor, T2R38, in Enteroendocrine Cells of the Colonic Mucosa of Overweight/Obese vs. Lean Subjects. PLoS One 2016; 11:e0147468. [PMID: 26866366 PMCID: PMC4750998 DOI: 10.1371/journal.pone.0147468] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/03/2016] [Indexed: 12/12/2022] Open
Abstract
Bitter taste receptors (T2Rs) are expressed in the mammalian gastrointestinal mucosa. In the mouse colon, T2R138 is localized to enteroendocrine cells and is upregulated by long-term high fat diet that induces obesity. The aims of this study were to test whether T2R38 expression is altered in overweight/obese (OW/OB) compared to normal weight (NW) subjects and characterize the cell types expressing T2R38, the human counterpart of mouse T2R138, in human colon. Colonic mucosal biopsies were obtained during colonoscopy from 35 healthy subjects (20 OW/OB and 15 NW) and processed for quantitative RT-PCR and immunohistochemistry using antibodies to T2R38, chromogranin A (CgA), glucagon like peptide-1 (GLP-1), cholecystokinin (CCK), or peptide YY (PYY). T2R38 mRNA levels in the colonic mucosa of OW/OB were increased (> 2 fold) compared to NW subjects but did not reach statistical significance (P = 0.06). However, the number of T2R38 immunoreactive (IR) cells was significantly increased in OW/OB vs. NW subjects (P = 0.01) and was significantly correlated with BMI values (r = 0.7557; P = 0.001). In both OW/OB and NW individuals, all T2R38-IR cells contained CgA-IR supporting they are enteroendocrine. In both groups, T2R38-IR colocalized with CCK-, GLP1- or PYY-IR. The overall CgA-IR cell population was comparable in OW/OB and NW individuals. This study shows that T2R38 is expressed in distinct populations of enteroendocrine cells in the human colonic mucosa and supports T2R38 upregulation in OW/OB subjects. T2R38 might mediate host functional responses to increased energy balance and intraluminal changes occurring in obesity, which could involve peptide release from enteroendocrine cells.
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Affiliation(s)
- Rocco Latorre
- CURE/DDRC, Division of Digestive Diseases, Department Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jennifer Huynh
- CURE/DDRC, Division of Digestive Diseases, Department Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Maurizio Mazzoni
- Department of Veterinary Medical Science, University of Bologna, Bologna, Italy
| | - Arpana Gupta
- Oppenheimer Family Center for Neurobiology of Stress, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Elena Bonora
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Paolo Clavenzani
- Department of Veterinary Medical Science, University of Bologna, Bologna, Italy
| | - Lin Chang
- CURE/DDRC, Division of Digestive Diseases, Department Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Oppenheimer Family Center for Neurobiology of Stress, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Emeran A. Mayer
- CURE/DDRC, Division of Digestive Diseases, Department Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Oppenheimer Family Center for Neurobiology of Stress, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Roberto De Giorgio
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Catia Sternini
- CURE/DDRC, Division of Digestive Diseases, Department Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
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22
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Douglas JE, Saunders CJ, Reed DR, Cohen NA. A role for airway taste receptor modulation in the treatment of upper respiratory infections. Expert Rev Respir Med 2016; 10:157-70. [PMID: 26731661 DOI: 10.1586/17476348.2016.1135742] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Taste receptors, initially identified in the oral epithelium, have since been shown to be widely distributed, being found in the upper and lower respiratory tracts, gastrointestinal epithelium, thyroid, and brain. The presence of taste receptors in the nasal epithelium has led to the discovery of their role in innate immunity, defending the paranasal sinuses against pathogens. This article addresses the current paradigm for understanding the role of extraoral taste receptors, specifically the T2R38 bitter taste receptor and the T1R2+3 sweet taste receptor, in respiratory innate defenses and presents evidence for the use of these and other taste receptors as therapeutic targets in the management of chronic rhinosinusitis. Future studies should focus on understanding the polymorphisms of taste receptors beyond T2R38 to fully elucidate their potential therapeutic use and lay the groundwork for their modulation in a clinical setting to decrease the health impact and economic burden of upper respiratory disease.
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Affiliation(s)
- Jennifer E Douglas
- a Perelman School of Medicine , University of Pennsylvania , Philadelphia , PA , USA.,b Department of Otorhinolaryngology-Head and Neck Surgery , University of Pennsylvania Health System , Philadelphia , PA , USA.,c Monell Chemical Senses Center , Philadelphia , PA , USA
| | - Cecil J Saunders
- b Department of Otorhinolaryngology-Head and Neck Surgery , University of Pennsylvania Health System , Philadelphia , PA , USA
| | | | - Noam A Cohen
- a Perelman School of Medicine , University of Pennsylvania , Philadelphia , PA , USA.,b Department of Otorhinolaryngology-Head and Neck Surgery , University of Pennsylvania Health System , Philadelphia , PA , USA.,c Monell Chemical Senses Center , Philadelphia , PA , USA.,d Philadelphia Veterans Affairs Medical Center Surgical Services , Philadelphia , PA , USA
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23
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Gaida MM, Dapunt U, Hänsch GM. Sensing developing biofilms: the bitter receptor T2R38 on myeloid cells. Pathog Dis 2016; 74:ftw004. [PMID: 26782143 PMCID: PMC4748947 DOI: 10.1093/femspd/ftw004] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2016] [Indexed: 01/17/2023] Open
Abstract
Quorum-sensing molecules, also known as autoinducer, are essential for bacterial biofilm formation. Our focus is on N-(3-oxododecanoyl)-L-homoserine lactone (AHL-12), because it is also known as an ‘interkingdom signalling molecule’, which means that it also interacts with mammalian cells. AHL-12 activates defence-relevant functions of phagocytic cells, including enhancement of phagocytosis, increased expression of adhesion receptors and induction of chemotaxis. This leads to the hypothesis that early recognition of developing biofilms might be the key to a successful host defence against biofilm infection. In that context we studied activation of phagocytic cells by AHL-12, and found that phagocytes are activated via a rather specialized receptor that was not previously described on myeloid cells, the bitter taste receptor T2R38. Taste receptors are commonly associated with cells of the gustatory system. The extragustatory expression, however, suggests an additional role, namely the sensing of the onset of bacterial biofilm infection. Myeloid cells express the bitter taste receptor T2R38 als ligand for the quorum-sensing molecule of Pseudomonas aeruginosa N-(3-oxododecanoyl)-L-homoserine lactone (AHL-12).
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Affiliation(s)
- Matthias Martin Gaida
- Institute for Pathology, Heidelberg University, Im Neuenheimer Feld 224, 69120 Heidelberg, Germany
| | - Ulrike Dapunt
- Center for Orthopaedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany
| | - Gertrud Maria Hänsch
- Institute for Immunology, Heidelberg University, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany
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Tizzano M, Grigereit L, Shultz N, Clary MS, Finger TE. Immunohistochemical Analysis of Human Vallate Taste Buds. Chem Senses 2015; 40:655-60. [PMID: 26400924 DOI: 10.1093/chemse/bjv048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The morphology of the vallate papillae from postmortem human samples was investigated with immunohistochemistry. Microscopically, taste buds were present along the inner wall of the papilla, and in some cases in the outer wall as well. The typical taste cell markers PLCβ2, GNAT3 (gustducin) and the T1R3 receptor stain elongated cells in human taste buds consistent with the Type II cells in rodents. In the human tissue, taste bud cells that stain with Type II cell markers, PLCβ2 and GNAT3, also stain with villin antibody. Two typical immunochemical markers for Type III taste cells in rodents, PGP9.5 and SNAP25, fail to stain any taste bud cells in the human postmortem tissue, although these antibodies do stain numerous nerve fibers throughout the specimen. Car4, another Type III cell marker, reacted with only a few taste cells in our samples. Finally, human vallate papillae have a general network of innervation similar to rodents and antibodies directed against SNAP25, PGP9.5, acetylated tubulin and P2X3 all stain free perigemmal nerve endings as well as intragemmal taste fibers. We conclude that with the exception of certain molecular features of Type III cells, human vallate papillae share the structural, morphological, and molecular features observed in rodents.
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Affiliation(s)
- Marco Tizzano
- Rocky Mountain Taste & Smell Center, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA, Department of Cell & Developmental Biology, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA and
| | - Laura Grigereit
- Rocky Mountain Taste & Smell Center, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA, Department of Cell & Developmental Biology, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA and
| | - Nicole Shultz
- Rocky Mountain Taste & Smell Center, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA, Department of Cell & Developmental Biology, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA and
| | - Matthew S Clary
- Rocky Mountain Taste & Smell Center, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA, Department of Otolaryngology, University of Colorado School of Medicine, 12700 E. 19th Avenue, Aurora, CO 80045, USA
| | - Thomas E Finger
- Rocky Mountain Taste & Smell Center, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA, Department of Cell & Developmental Biology, University of Colorado School of Medicine, 12801 E. 17th Avenue, Aurora, CO 80045, USA and Department of Otolaryngology, University of Colorado School of Medicine, 12700 E. 19th Avenue, Aurora, CO 80045, USA
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Voigt A, Hübner S, Döring L, Perlach N, Hermans-Borgmeyer I, Boehm U, Meyerhof W. Cre-Mediated Recombination in Tas2r131 Cells-A Unique Way to Explore Bitter Taste Receptor Function Inside and Outside of the Taste System. Chem Senses 2015; 40:627-39. [PMID: 26377344 DOI: 10.1093/chemse/bjv049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The type 2 taste receptors (Tas2rs) comprise a large family of G protein-coupled receptors that recognize compounds bitter to humans and aversive to vertebrates. Tas2rs are expressed in both gustatory and nongustatory tissues, however, identification and functional analyses of T2R-expressing cells have been difficult in most tissues. To overcome these limitations and to be able to manipulate Tas2r-expressing cells in vivo, we used gene-targeting to generate a Tas2r131-specific Cre knock-in mouse strain. We then employed a binary genetic approach to characterize Cre-mediated recombination in these animals and to investigate Tas2r131 expression during postnatal development. We demonstrate that a Cre-activated fluorescent reporter reliably visualizes Tas2r131-cells in gustatory tissue. We show that the onset of Tas2r131 as well as of α-Gustducin expression is initiated at different developmental stages depending on the type of taste bud. Furthermore, the number of Tas2r131- and α-Gustducin-expressing cells increased during postnatal development. Our results demonstrate that the Tas2r131-expressing cells constitute a subpopulation of α-Gustducin positive cells at all stages. We detected Tas2r131-expressing cells in several nongustatory tissues including lung, trachea, ovary, ganglia, and brain. Thus, the Tas2r131-Cre strain will help to dissect the functional role of Tas2r131 cells in both gustatory and nongustatory tissues in the future.
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Affiliation(s)
- Anja Voigt
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany, Institute for Neural Signal Transduction, Center for Molecular Neurobiology Hamburg, Falkenried 94, 20251 Hamburg, Germany and
| | - Sandra Hübner
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Linda Döring
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Nathalie Perlach
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Irm Hermans-Borgmeyer
- Transgenic Animals Service Group, Center for Molecular Neurobiology Hamburg, UKE, Martinistraße 52, 20246 Hamburg, Germany
| | - Ulrich Boehm
- Institute for Neural Signal Transduction, Center for Molecular Neurobiology Hamburg, Falkenried 94, 20251 Hamburg, Germany and Present address: Department of Pharmacology and Toxicology, University of Saarland, School of Medicine, 66421 Homburg, Germany
| | - Wolfgang Meyerhof
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany,
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Maurer S, Wabnitz GH, Kahle NA, Stegmaier S, Prior B, Giese T, Gaida MM, Samstag Y, Hänsch GM. Tasting Pseudomonas aeruginosa Biofilms: Human Neutrophils Express the Bitter Receptor T2R38 as Sensor for the Quorum Sensing Molecule N-(3-Oxododecanoyl)-l-Homoserine Lactone. Front Immunol 2015; 6:369. [PMID: 26257736 PMCID: PMC4513437 DOI: 10.3389/fimmu.2015.00369] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/06/2015] [Indexed: 01/29/2023] Open
Abstract
Bacteria communicate with one another via specialized signaling molecules, known as quorum sensing molecules or autoinducers. The Pseudomonas aeruginosa-derived quorum sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (AHL-12), however, also activates mammalian cells. As shown previously, AHL-12-induced chemotaxis, up-regulated CD11b expression, and enhanced phagocytosis of polymorphonuclear neutrophils. Circumstantial evidence concurred with a receptor for AHL-12, which has been elusive so far. We now investigated the bitter receptor T2R38 as a potential candidate. Although identified as a taste receptor, extragustatory cells express T2R38, for example, epithelial cells in the lung. We now detected T2R38 in peripheral blood neutrophils, monocytes, and lymphocytes. T2R38 is not only found on the cell membrane but also intracellular. In neutrophils, T2R38 was located in vesicles with characteristics of lipid droplets, and super-resolution microscopy showed a co-localization with the lipid droplet membrane. Neutrophils take up AHL-12, and it co-localized with T2R38 as seen by laser scan microscopy. Binding of AHL-12 to T2R28 was confirmed by pull-down assays using biotin-coupled AHL-12 as bait. A commercially available antibody to T2R38 inhibited binding of AHL-12 to neutrophils, and this antibody by itself stimulated neutrophils, similarly to AHL-12. In conclusion, our data provide evidence for expression of functional T2R38 on neutrophils, and are compatible with the notion that T2R38 is the receptor for AHL-12.
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Affiliation(s)
- Susanne Maurer
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
| | - Guido H Wabnitz
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
| | - Nadine A Kahle
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
| | - Sabine Stegmaier
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
| | - Birgit Prior
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
| | - Thomas Giese
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
| | - Matthias Martin Gaida
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany ; Institute of Pathology, University of Heidelberg , Heidelberg , Germany
| | - Yvonne Samstag
- Institute for Immunology, University of Heidelberg , Heidelberg , Germany
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Wölfle U, Elsholz FA, Kersten A, Haarhaus B, Müller WE, Schempp CM. Expression and functional activity of the bitter taste receptors TAS2R1 and TAS2R38 in human keratinocytes. Skin Pharmacol Physiol 2015; 28:137-46. [PMID: 25573083 DOI: 10.1159/000367631] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 08/11/2014] [Indexed: 11/19/2022]
Abstract
Recent studies have shown that human bitter taste receptors (TAS2Rs) are not only expressed in mucous epithelial cells of the tongue, but also in epithelial cells of the colon, stomach and upper respiratory tract. These cell types come in close contact with external bitter compounds by ingestion or breathing. In the present work we addressed the question whether bitter taste receptors might also be expressed in cornified epithelial cells of the skin. Here, we show for the first time the expression of TAS2R1 and TAS2R38 in human skin. Double staining of HaCaT cells and primary keratinocytes demonstrated the colocalization of TAS2R1 and TAS2R38 with the adaptor protein α-gustducin that is essential for signal transduction upon ligand binding. To test if TAS2Rs in keratinocytes are functional, we stimulated HaCaT cells with diphenidol, a clinically used bitter-tasting antiemetic, or amarogentin, the bitterest plant substance, that binds TAS2Rs, including TAS2R1 and TAS2R38. Diphenidol and amarogentin induced calcium influx. Furthermore, in keratinocytes diphenidol and amarogentin stimulated the expression of the differentiation markers keratin 10, involucrin and transglutaminase. Therefore, apart from the known role in mucous membranes of the gastrointestinal tract, TAS2Rs are expressed in the epidermis and might play a role in keratinocyte differentiation.
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Affiliation(s)
- Ute Wölfle
- Research Center skinitial, Department of Dermatology, University Medical Center, Freiburg, Germany
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Lee RJ, Cohen NA. Taste receptors in innate immunity. Cell Mol Life Sci 2015; 72:217-36. [PMID: 25323130 PMCID: PMC4286424 DOI: 10.1007/s00018-014-1736-7] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 09/11/2014] [Accepted: 09/16/2014] [Indexed: 02/07/2023]
Abstract
Taste receptors were first identified on the tongue, where they initiate a signaling pathway that communicates information to the brain about the nutrient content or potential toxicity of ingested foods. However, recent research has shown that taste receptors are also expressed in a myriad of other tissues, from the airway and gastrointestinal epithelia to the pancreas and brain. The functions of many of these extraoral taste receptors remain unknown, but emerging evidence suggests that bitter and sweet taste receptors in the airway are important sentinels of innate immunity. This review discusses taste receptor signaling, focusing on the G-protein-coupled receptors that detect bitter, sweet, and savory tastes, followed by an overview of extraoral taste receptors and in-depth discussion of studies demonstrating the roles of taste receptors in airway innate immunity. Future research on extraoral taste receptors has significant potential for identification of novel immune mechanisms and insights into host-pathogen interactions.
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Affiliation(s)
- Robert J. Lee
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Ravdin Building, 5th floor, Philadelphia, PA 19104 USA
| | - Noam A. Cohen
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Ravdin Building, 5th floor, Philadelphia, PA 19104 USA
- Philadelphia Veterans Affairs Medical Center Surgical Services, 3900 Woodland Ave, Philadelphia, PA 19104 USA
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Clark AA, Dotson CD, Elson AET, Voigt A, Boehm U, Meyerhof W, Steinle NI, Munger SD. TAS2R bitter taste receptors regulate thyroid function. FASEB J 2014; 29:164-72. [PMID: 25342133 DOI: 10.1096/fj.14-262246] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Dysregulation of thyroid hormones triiodothyronine and thyroxine (T3/T4) can impact metabolism, body composition, and development. Thus, it is critical to identify novel mechanisms that impact T3/T4 production. We found that type 2 taste receptors (TAS2Rs), which are activated by bitter-tasting compounds such as those found in many foods and pharmaceuticals, negatively regulate thyroid-stimulating hormone (TSH)-dependent Ca(2+) increases and TSH-dependent iodide efflux in thyrocytes. Immunohistochemical Tas2r-dependent reporter expression and real-time PCR analyses reveal that human and mouse thyrocytes and the Nthy-Ori 3-1 human thyrocyte line express several TAS2Rs. Five different agonists for thyrocyte-expressed TAS2Rs reduced TSH-dependent Ca(2+) release in Nthy-Ori 3-1 cells, but not basal Ca(2+) levels, in a dose-dependent manner. Ca(2+) responses were unaffected by 6-n-propylthiouracil, consistent with the expression of an unresponsive variant of its cognate receptor, TAS2R38, in these cells. TAS2R agonists also inhibited basal and TSH-dependent iodide efflux. Furthermore, a common TAS2R42 polymorphism is associated with increased serum T4 levels in a human cohort. Our findings indicate that TAS2Rs couple the detection of bitter-tasting compounds to changes in thyrocyte function and T3/T4 production. Thus, TAS2Rs may mediate a protective response to overingestion of toxic materials and could serve as new druggable targets for therapeutic treatment of hypo- or hyperthyroidism.
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Affiliation(s)
- Adam A Clark
- Department of Anatomy and Neurobiology, Program in Toxicology
| | | | - Amanda E T Elson
- Department of Anatomy and Neurobiology, Program in Neuroscience, and
| | - Anja Voigt
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam Rehbruecke, Nuthetal, Germany; and
| | - Ulrich Boehm
- Department of Pharmacology and Toxicology, University of Saarland School of Medicine, Homburg, Germany
| | - Wolfgang Meyerhof
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam Rehbruecke, Nuthetal, Germany; and
| | - Nanette I Steinle
- Department of Medicine, Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Steven D Munger
- Department of Anatomy and Neurobiology, Program in Toxicology, Program in Neuroscience, and Department of Medicine, Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, Maryland, USA;
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Abstract
The superfamily of G protein-coupled receptors (GPCRs) mediates numerous physiological processes, including neurotransmission, cell differentiation and metabolism, and sensory perception. In recent years, it became evident that these receptors might function not only as monomeric receptors but also as homo- or heteromeric receptor complexes. The family of TAS1R taste receptors are prominent examples of GPCR dimerization as they act as obligate functional heteromers: TAS1R1 and TAS1R3 combine to form an umami taste receptor, while the combination of TAS1R2 and TAS1R3 is a sweet taste receptor. So far, TAS2Rs, a second family of ~25 taste receptors in humans that mediates responses to bitter compounds, have been shown to function on their own, but if they do so as receptor monomers or as homomeric receptors still remains unknown. Using two different experimental approaches, we have recently shown that TAS2Rs can indeed form both homomeric and heteromeric receptor complexes. The employed techniques, coimmunoprecipitations and bioluminescence resonance energy transfer (BRET), are based on different principles and complement each other well and therefore provided compelling evidences for TAS2R oligomerization. Furthermore, we have adapted the protocols to include a number of controls and for higher throughput to accommodate the investigation of a large number of receptors and receptor combinations. Here, we present the protocols in detail.
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Lee RJ, Kofonow JM, Rosen PL, Siebert AP, Chen B, Doghramji L, Xiong G, Adappa ND, Palmer JN, Kennedy DW, Kreindler JL, Margolskee RF, Cohen NA. Bitter and sweet taste receptors regulate human upper respiratory innate immunity. J Clin Invest 2014; 124:1393-405. [PMID: 24531552 DOI: 10.1172/jci72094] [Citation(s) in RCA: 294] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 12/11/2013] [Indexed: 12/11/2022] Open
Abstract
Bitter taste receptors (T2Rs) in the human airway detect harmful compounds, including secreted bacterial products. Here, using human primary sinonasal air-liquid interface cultures and tissue explants, we determined that activation of a subset of airway T2Rs expressed in nasal solitary chemosensory cells activates a calcium wave that propagates through gap junctions to the surrounding respiratory epithelial cells. The T2R-dependent calcium wave stimulated robust secretion of antimicrobial peptides into the mucus that was capable of killing a variety of respiratory pathogens. Furthermore, sweet taste receptor (T1R2/3) activation suppressed T2R-mediated antimicrobial peptide secretion, suggesting that T1R2/3-mediated inhibition of T2Rs prevents full antimicrobial peptide release during times of relative health. In contrast, during acute bacterial infection, T1R2/3 is likely deactivated in response to bacterial consumption of airway surface liquid glucose, alleviating T2R inhibition and resulting in antimicrobial peptide secretion. We found that patients with chronic rhinosinusitis have elevated glucose concentrations in their nasal secretions, and other reports have shown that patients with hyperglycemia likewise have elevated nasal glucose levels. These data suggest that increased glucose in respiratory secretions in pathologic states, such as chronic rhinosinusitis or hyperglycemia, promotes tonic activation of T1R2/3 and suppresses T2R-mediated innate defense. Furthermore, targeting T1R2/3-dependent suppression of T2Rs may have therapeutic potential for upper respiratory tract infections.
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Taste Receptor Gene Expression Outside the Gustatory System. TOPICS IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1007/7355_2014_79] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Extrasensory perception: odorant and taste receptors beyond the nose and mouth. Pharmacol Ther 2013; 142:41-61. [PMID: 24280065 DOI: 10.1016/j.pharmthera.2013.11.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 11/04/2013] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of transmembrane receptors and are prime therapeutic targets. The odorant and taste receptors account for over half of the GPCR repertoire, yet they are generally excluded from large-scale, drug candidate analyses. Accumulating molecular evidence indicates that the odorant and taste receptors are widely expressed throughout the body and functional beyond the oronasal cavity - with roles including nutrient sensing, autophagy, muscle regeneration, regulation of gut motility, protective airway reflexes, bronchodilation, and respiratory disease. Given this expanding array of actions, the restricted perception of these GPCRs as mere mediators of smell and taste is outdated. Moreover, delineation of the precise actions of odorant and taste GPCRs continues to be hampered by the relative paucity of selective and specific experimental tools, as well as the lack of defined receptor pharmacology. In this review, we summarize the evidence for expression and function of odorant and taste receptors in tissues beyond the nose and mouth, and we highlight their broad potential in physiology and pathophysiology.
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Cao JT, Chen ZX, Hao XY, Zhang PH, Zhu JJ. Quantum Dots-Based Immunofluorescent Microfluidic Chip for the Analysis of Glycan Expression at Single-Cells. Anal Chem 2012; 84:10097-104. [DOI: 10.1021/ac302609y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Jun-Tao Cao
- State Key Laboratory of Analytical Chemistry for Life Science,
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China
| | - Zi-Xuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science,
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China
| | - Xiao-Yao Hao
- State Key Laboratory of Analytical Chemistry for Life Science,
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China
| | - Peng-Hui Zhang
- State Key Laboratory of Analytical Chemistry for Life Science,
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China
| | - Jun-Jie Zhu
- State Key Laboratory of Analytical Chemistry for Life Science,
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China
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Clark AA, Liggett SB, Munger SD. Extraoral bitter taste receptors as mediators of off-target drug effects. FASEB J 2012; 26:4827-31. [PMID: 22964302 DOI: 10.1096/fj.12-215087] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We present a novel hypothesis that could explain many off-target effects of diverse pharmaceuticals. Specifically, we propose that any drug with a bitter taste could have unintended actions in the body through stimulation of extraoral type 2 taste receptors (T2Rs). T2Rs were first identified in the oral cavity, where they function as bitter taste receptors. However, recent findings indicate that they are also expressed outside the gustatory system, including in the gastrointestinal and respiratory systems. T2R ligands include a diverse array of natural and synthetic compounds, many of which are toxins. Notably, many pharmaceuticals taste bitter, with compounds such as chloroquine, haloperidol, erythromycin, procainamide, and ofloxacin known to activate T2Rs. Bitter-tasting compounds can have specific physiological effects in T2R-expressing cells. For example, T2Rs are found in some gastrointestinal endocrine cells, including those that secrete the peptide hormones (e.g., ghrelin and glucagon-like peptide-1) in response to stimulation by bitter-tasting compounds. In the respiratory system, stimulation of T2Rs expressed in respiratory epithelia and smooth muscle has been implicated in protective airway reflexes, ciliary beating, and bronchodilation. If our hypothesis is confirmed, it would offer a new paradigm for understanding the off-target actions of diverse drugs and could reveal potential new therapeutic targets.
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Affiliation(s)
- Adam A Clark
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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