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Hyodo A, Mikami A, Horie K, Mitoh Y, Ninomiya Y, Iida S, Yoshida R. Salivary buffering capacity is correlated with umami but not sour taste sensitivity in healthy adult Japanese subjects. Arch Oral Biol 2024; 165:106013. [PMID: 38833772 DOI: 10.1016/j.archoralbio.2024.106013] [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: 01/18/2024] [Revised: 05/08/2024] [Accepted: 05/23/2024] [Indexed: 06/06/2024]
Abstract
OBJECTIVE Saliva serves multiple important functions crucial for maintaining a healthy oral and systemic environment. Among them, the pH buffering effect, which is primarily mediated by bicarbonate ions, helps maintain oral homeostasis by neutralizing acidity from ingested foods. Therefore, higher buffering capacity, reflecting the ability to neutralize oral acidity, may influence taste sensitivity, especially for sour taste since it involves sensing H+ ions. This study aims to explore the relationship between salivary buffering capacity and taste sensitivities to the five basic tastes in healthy adult humans. DESIGN Eighty seven healthy adult students participated in this study. Resting saliva volume was measured using the spitting method. The liquid colorimetric test was used to assess salivary buffering capacity. The whole-mouth taste testing method was employed to determine the recognition threshold for each tastant (NaCl, sucrose, citric acid, quinine-HCl, monosodium glutamate). RESULTS Taste recognition thresholds for sour taste as well as sweet, salty, and bitter tastes showed no correlation with salivary buffering capacity. Interestingly, a negative relationship was observed between recognition threshold for umami taste and salivary buffering capacity. Furthermore, a positive correlation between salivary buffering capacity and resting saliva volume was observed. CONCLUSIONS Salivary buffering capacity primarily influences sensitivity to umami taste, but not sour and other tastes.
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Affiliation(s)
- Aiko Hyodo
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Department of Oral and Maxillofacial Reconstructive Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Ayaka Mikami
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Department of Oral and Maxillofacial Reconstructive Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Kengo Horie
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Yoshihiro Mitoh
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Yuzo Ninomiya
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Graduate School of Dental Science, Kyushu University, Japan; Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Seiji Iida
- Department of Oral and Maxillofacial Reconstructive Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Ryusuke Yoshida
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan.
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Cai S, Xie N, Zheng L, Li Q, Zhang S, Huang Q, Luo W, Wu M, Wang Y, Du Y, Deng SP, Cai L. Sweet taste receptors play roles in artificial sweetener-induced enhanced urine output in mice. NPJ Sci Food 2024; 8:2. [PMID: 38182603 PMCID: PMC10770165 DOI: 10.1038/s41538-023-00236-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 10/20/2023] [Indexed: 01/07/2024] Open
Abstract
Sweet taste receptors found in oral and extra oral tissues play important roles in the regulation of many physiological functions. Studies have shown that urine volume increases during the lifetime exposure to artificial sweeteners. However, the detailed molecular mechanism and the general effects of different artificial sweeteners exposure on urine volume remain unclear. In this study, we investigated the relationship between urinary excretion and the sweet taste receptor expression in mice after three artificial sweeteners exposure in a higher or lower concentration via animal behavioral studies, western blotting, and real-time quantitative PCR experiment in rodent model. Our results showed that high dose of acesulfame potassium and saccharin can significantly enhance the urine output and there was a positive correlation between K+ and urination volume. The acesulfame potassium administration assay of T1R3 knockout mice showed that artificial sweeteners may affect the urine output directly through the sweet taste signaling pathway. The expression of T1R3 encoding gene can be up-regulated specifically in bladder but not in kidney or other organs we tested. Through our study, the sweet taste receptors, distributing in many tissues as bladder, were indicated to function in the enhanced urine output. Different effects of long-term exposure to the three artificial sweeteners were shown and acesulfame potassium increased urine output even at a very low concentration.
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Affiliation(s)
- Shuangfeng Cai
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Ningning Xie
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China
- Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310006, PR China
| | - Ling Zheng
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China
| | - Quan Li
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Siyu Zhang
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Qinghua Huang
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Wei Luo
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Mei Wu
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Yidan Wang
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Yilun Du
- Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Fujian Molecular Medicine, Key Laboratory of Xiamen Marine and Gene Drugs, School of Biomedical Sciences and School of Medicine, Huaqiao University, Xiamen, 361021, PR China
| | - Shao-Ping Deng
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China
| | - Lei Cai
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China.
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Kitajima S, Maruyama Y, Kuroda M. Volatile Short-Chain Aliphatic Aldehydes Act as Taste Modulators through the Orally Expressed Calcium-Sensing Receptor CaSR. Molecules 2023; 28:4585. [PMID: 37375140 DOI: 10.3390/molecules28124585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/03/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Aldehydes are natural volatile aroma compounds generated by the Maillard reaction of sugars and amino acids in food and affect the flavor of food. They have been reported to exert taste-modifying effects, such as increases in taste intensity at concentrations below the odor detection threshold. The present study examined the taste-enhancing effects of short-chain aliphatic aldehydes, such as isovaleraldehyde (IVAH) and 2-methylbutyraldehyde, thus attempting to identify the taste receptors involved. The results obtained revealed that IVAH enhanced the taste intensity of taste solutions even under the condition of olfactory deprivation by a noseclip. Furthermore, IVAH activated the calcium-sensing receptor CaSR in vitro. Receptor assays on aldehyde analogues showed that C3-C6 aliphatic aldehydes and methional, a C4 sulfur aldehyde, activated CaSR. These aldehydes functioned as a positive allosteric modulator for CaSR. The relationship between the activation of CaSR and taste-modifying effects was investigated by a sensory evaluation. Taste-modifying effects were found to be dependent on the activation state of CaSR. Collectively, these results suggest that short-chain aliphatic aldehydes function as taste modulators that modify sensations by activating orally expressed CaSR. We propose that volatile aroma aldehydes may also partially contribute to the taste-modifying effect via the same molecular mechanism as kokumi substances.
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Affiliation(s)
- Seiji Kitajima
- Institute of Food Research & Technologies, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Kanagawa, Japan
| | - Yutaka Maruyama
- Institute of Food Research & Technologies, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Kanagawa, Japan
| | - Motonaka Kuroda
- Institute of Food Research & Technologies, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Kanagawa, Japan
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4
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Chisini L, Costa F, Horta B, Tovo-Rodrigues L, Demarco F, Correa M. Sweet Taste Receptor Gene and Caries Trajectory in the Life Course. J Dent Res 2023; 102:422-430. [PMID: 36609159 PMCID: PMC10041601 DOI: 10.1177/00220345221138569] [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: 01/09/2023] Open
Abstract
This study aims to investigate whether the trajectory of dental caries in the life course is associated with rs307355 (TAS1R3) and rs35874116 (TAS1R2) and if there is an epistatic association between rs307355 (TAS1R3) and rs35874116 (TAS1R2). A representative sample of all 5,914 births from the 1982 Pelotas birth cohort was prospectively investigated, and the decayed, missing, and filled teeth (DMF-T) components were assessed at ages 15 (n = 888), 24 (n = 720), and 31 (n = 539) y. Group-based trajectory modeling was used to identify groups with similar trajectories of DMF-T components in the life course. Genetic material was collected, and rs307355 (TAS1R3) and rs35874116 (TAS1R2) were genotyped. Ethnicity was evaluated using ADMIXTURE. Generalized multifactor dimensionality reduction software was used to investigate epistatic interactions. Considering rs307355 (TAS1R3) in the additive effect, the genotype TT was associated with the high decayed trajectory group (odds ratio [OR] = 4.52; 95% confidence interval [CI], 1.15-17.74) and the high missing trajectory group (OR = 3.35; 95% CI, 1.09-10.26). In the dominant effect, the genotype CT/TT was associated with the high decayed trajectory group (OR = 1.64; 95% CI, 1.14-2.35). Allele T was associated with an increased odds of 64% (OR = 1.64; 95% CI, 1.20-2.25) for the decayed component and 41% (OR = 1.41; 95% CI, 1.04-1.92) for the missing component. No associations were observed between rs307355 (TAS1R3) and the filled component. rs35874116 (TAS1R2) was not associated with DMF-T components. Positive epistatic interactions were observed involving rs307355 (TAS1R3) and rs35874116 (TAS1R2) with the decayed component (OR = 1.72; 95% CI, 1.04-2.84). Thus, rs307355 (TAS1R3) genotypes and alleles seem positively associated with the trajectory of decayed and missing components in the life course. Epistatic interaction between rs307355 and rs35874116 may increase the decayed caries trajectory.
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Affiliation(s)
- L.A. Chisini
- Graduate Program in Dentistry, Federal University of Juiz de Fora, Governador Valadares, MG, Brazil
| | - F.D.S. Costa
- International Center for Equity in Health, Postgraduate Program of Epidemiology, Federal University of Pelotas, Pelotas, Brazil
| | - B.L. Horta
- Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - L. Tovo-Rodrigues
- Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - F.F. Demarco
- Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - M.B. Correa
- Graduate Program in Dentistry, Federal University of Juiz de Fora, Governador Valadares, MG, Brazil
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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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6
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Taste Responses and Ingestive Behaviors to Ingredients of Fermented Milk in Mice. Foods 2023; 12:foods12061150. [PMID: 36981077 PMCID: PMC10048529 DOI: 10.3390/foods12061150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/13/2023] [Accepted: 03/02/2023] [Indexed: 03/11/2023] Open
Abstract
Fermented milk is consumed worldwide because of its nutritious and healthful qualities. Although it is somewhat sour, causing some to dislike it, few studies have examined taste aspects of its ingredients. Wild-type mice and T1R3-GFP-KO mice lacking sweet/umami receptors were tested with various taste components (sucrose, galactose, lactose, galacto-oligosaccharides, fructo-oligosaccharides, l- and d-lactic acid) using 48 h two-bottle tests and short-term lick tests. d-lactic acid levels were measured after the ingestion of d- or; l-lactic acid or water to evaluate d-lactic acidosis. In wild-type mice, for the sweet ingredients the number of licks increased in a concentration-dependent manner, but avoidance was observed at higher concentrations in 48 h two-bottle tests; the sour ingredients d- and l-lactic acid showed concentration-dependent decreases in preference in both short- and long-term tests. In 48 h two-bottle tests comparing d- and l-lactic acid, wild-type but not T1R3-GFP-KO mice showed higher drinking rates for l-lactic acid. d-lactic acidosis did not occur and thus did not contribute to this preference. These results suggest that intake in short-term lick tests varied by preference for each ingredient, whereas intake variation in long-term lick tests reflects postingestive effects. l-lactic acid may have some palatable taste in addition to sour taste.
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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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Somatosensory and Gustatory Profiling in the Orofacial Region. Diagnostics (Basel) 2022; 12:diagnostics12123198. [PMID: 36553205 PMCID: PMC9777464 DOI: 10.3390/diagnostics12123198] [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] [Received: 11/23/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Quantitative sensory testing (QST) is a standard procedure in medicine to describe sensory patterns in various pathologies. The aim of this prospective clinical study was to define reference values of the trigeminal nerve (V3), including taste qualities, to create a compatibility for sensory loss or gain in pathologies. Fifty-one patients were included, and a standardized testing battery with 11 QST parameters according to the German Research Network on Neuropathic Pain (DFNS) was applied complemented by quantitative gustatory assessments. Significant somatosensory differences were found between the test sites (MDT at the chin, WDT at the lower lip) but no effect was detected for gender, age, and between body types. Taste sensitivity was dependent on concentration, gender (females being more sensitive) and increasing age (for bitter and sour taste). We provide reference values for somatosensory and gustatory testing of the facial area. Our data facilitate the detection of neurosensory abnormalities in the orofacial region. This might also serve as a control setting for COVID-19.
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Thomas DC, Chablani D, Parekh S, Pichammal RC, Shanmugasundaram K, Pitchumani PK. Dysgeusia: A review in the context of COVID-19. J Am Dent Assoc 2021; 153:251-264. [PMID: 34799014 PMCID: PMC8595926 DOI: 10.1016/j.adaj.2021.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 08/07/2021] [Accepted: 08/20/2021] [Indexed: 12/19/2022]
Abstract
Background Taste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus. Types of Studies Reviewed The authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes. Results The authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection. Conclusions Gustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders. Practical Implications Timely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.
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Obikane Y, Toyono T, Kokabu S, Matsuyama K, Kataoka S, Nakatomi M, Hosokawa R, Seta Y. Myogenic differentiation 1 and transcription factor 12 activate the gene expression of mouse taste receptor type 1 member 1. J Oral Biosci 2021; 63:420-428. [PMID: 34492379 DOI: 10.1016/j.job.2021.08.005] [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: 08/17/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Myogenic differentiation 1 (Myod1) is involved in the expression of taste receptor type 1 member 1 (Tas1r1) during myogenic differentiation. Further, the target genes of Myod1 participate in transcriptional control, muscle development, and synaptic function. We examined, for the first time, the function of Myod1 in the transcriptional regulation of Tas1r1. METHODS ENCODE chromatin immunoprecipitation and sequencing (ChIP-seq) data of myogenically differentiated C2C12 cells were analyzed to identify the Myod1 and transcription factor 12 (Tcf12) binding sites in the Tas1r1 promoter region. Luciferase reporter assays, DNA affinity precipitation assays, and co-immunoprecipitation assays were also performed to identify the functions of Myod1, Tcf12, and Krüppel-like factor 5 (Klf5). RESULTS Based on ENCODE ChIP-seq, Myod1 bound to the Tas1r1 promoter region containing E-boxes 1-3. Luciferase reporter assays revealed that site-directed E-box1 mutations significantly reduced promoter activation induced by Myod1 overexpression. According to the DNA affinity precipitation assay and co-immunoprecipitation assay, Myod1 formed a heterodimer with Tcf12 and bound to E-box1. Further, Klf5 bound to the GT box near E-box1, activating Tas1r1 expression. CONCLUSIONS During myogenic differentiation, the Myod1/Tcf12 heterodimer, in collaboration with Klf5, binds to E-box1 and activates Tas1r1 expression.
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Affiliation(s)
- Yui Obikane
- Division of Oral Reconstruction and Rehabilitation, Department of Oral Functions, 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.
| | - Shoichiro Kokabu
- Division of Molecular Signaling and Biochemistry, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | - Kae Matsuyama
- Division of Anatomy, 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
| | - Mitsushiro Nakatomi
- Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | - Ryuji Hosokawa
- Division of Oral Reconstruction and Rehabilitation, Department of Oral Functions, 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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11
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Huang T, Ohman LC, Clements AV, Whiddon ZD, Krimm RF. Variable Branching Characteristics of Peripheral Taste Neurons Indicates Differential Convergence. J Neurosci 2021; 41:4850-4866. [PMID: 33875572 PMCID: PMC8260161 DOI: 10.1523/jneurosci.1935-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 03/26/2021] [Accepted: 04/10/2021] [Indexed: 11/21/2022] Open
Abstract
Taste neurons are functionally and molecularly diverse, but their morphologic diversity remains completely unexplored. Using sparse cell genetic labeling, we provide the first reconstructions of peripheral taste neurons. The branching characteristics across 96 taste neurons show surprising diversity in their complexities. Individual neurons had 1-17 separate arbors entering between one and seven taste buds, 18 of these neurons also innervated non-taste epithelia. Axon branching characteristics are similar in gustatory neurons from male and female mice. Cluster analysis separated the neurons into four groups according to branch complexity. The primary difference between clusters was the amount of the nerve fiber within the taste bud available to contact taste-transducing cells. Consistently, we found that the maximum number of taste-transducing cells capable of providing convergent input onto individual gustatory neurons varied with a range of 1-22 taste-transducing cells. Differences in branching characteristics across neurons indicate that some neurons likely receive input from a larger number of taste-transducing cells than other neurons (differential convergence). By dividing neurons into two groups based on the type of taste-transducing cell most contacted, we found that neurons contacting primarily sour transducing cells were more heavily branched than those contacting primarily sweet/bitter/umami transducing cells. This suggests that neuron morphologies may differ across functional taste quality. However, the considerable remaining variability within each group also suggests differential convergence within each functional taste quality. Each possibility has functional implications for the system.SIGNIFICANCE STATEMENT Taste neurons are considered relay cells, communicating information from taste-transducing cells to the brain, without variation in morphology. By reconstructing peripheral taste neuron morphologies for the first time, we found that some peripheral gustatory neurons are simply branched, and can receive input from only a few taste-transducing cells. Other taste neurons are heavily branched, contacting many more taste-transducing cells than simply branched neurons. Based on the type of taste-transducing cell contacted, branching characteristics are predicted to differ across (and within) quality types (sweet/bitter/umami vs sour). Therefore, functional differences between neurons likely depends on the number of taste-transducing cells providing input and not just the type of cell providing input.
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Affiliation(s)
- Tao Huang
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Lisa C Ohman
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Anna V Clements
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Zachary D Whiddon
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Robin F Krimm
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
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12
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Ohman LC, Krimm RF. Variation in taste ganglion neuron morphology: insights into taste function and plasticity. CURRENT OPINION IN PHYSIOLOGY 2021; 20:134-139. [DOI: 10.1016/j.cophys.2020.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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A Super Stable Mutant of the Plant Protein Monellin Endowed with Enhanced Sweetness. Life (Basel) 2021; 11:life11030236. [PMID: 33809397 PMCID: PMC7999979 DOI: 10.3390/life11030236] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 12/11/2022] Open
Abstract
Sweet proteins are a class of proteins with the ability to elicit a sweet sensation in humans upon interaction with sweet taste receptor T1R2/T1R3. Single-chain Monellin, MNEI, is among the sweetest proteins known and it could replace sugar in many food and beverage recipes. Nonetheless, its use is limited by low stability and high aggregation propensity at neutral pH. To solve this inconvenience, we designed a new construct of MNEI, dubbed Mut9, which led to gains in both sweetness and stability. Mut9 showed an extraordinary stability in acidic and neutral environments, where we observed a melting temperature over 20 °C higher than that of MNEI. In addition, Mut9 resulted twice as sweet than MNEI. Both proteins were extensively characterized by biophysical and sensory analyses. Notably, Mut9 preserved its structure and function even after 10 min boiling, with the greatest differences being observed at pH 6.8, where it remained folded and sweet, whereas MNEI lost its structure and function. Finally, we performed a 6-month shelf-life assessment, and the data confirmed the greater stability of the new construct in a wide range of conditions. These data prove that Mut9 has an even greater potential for food and beverage applications than MNEI.
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14
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Jensterle M, Rizzo M, Janez A. Glucagon-Like Peptide 1 and Taste Perception: From Molecular Mechanisms to Potential Clinical Implications. Int J Mol Sci 2021; 22:ijms22020902. [PMID: 33477478 PMCID: PMC7830704 DOI: 10.3390/ijms22020902] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/03/2021] [Accepted: 01/15/2021] [Indexed: 12/14/2022] Open
Abstract
Preclinical studies provided some important insights into the action of glucagon-like peptide 1 (GLP-1) in taste perception. This review examines the literature to uncover some molecular mechanisms and connections between GLP-1 and the gustatory coding. Local GLP-1 production in the taste bud cells, the expression of GLP-1 receptor on the adjacent nerves, a functional continuum in the perception of sweet chemicals from the gut to the tongue and an identification of GLP-1 induced signaling pathways in peripheral and central gustatory coding all strongly suggest that GLP-1 is involved in the taste perception, especially sweet. However, the impact of GLP-1 based therapies on gustatory coding in humans remains largely unaddressed. Based on the molecular background we encourage further exploration of the tongue as a new treatment target for GLP-1 receptor agonists in clinical studies. Given that pharmacological manipulation of gustatory coding may represent a new potential strategy against obesity and diabetes, the topic is of utmost clinical relevance.
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Affiliation(s)
- Mojca Jensterle
- Diabetes and Metabolic Diseases, Division of Internal Medicine, Department of Endocrinology, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia;
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia
| | - Manfredi Rizzo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of South Carolina, Columbia, SC 29208, USA;
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, University of Palermo, 90133 Palermo, Italy
| | - Andrej Janez
- Diabetes and Metabolic Diseases, Division of Internal Medicine, Department of Endocrinology, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia;
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia
- Correspondence: ; Tel.: +386-1-522-3114; Fax: +386-1-522-9359
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15
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Zhu W, He W, Wang F, Bu Y, Li X, Li J. Prediction, molecular docking and identification of novel umami hexapeptides derived from Atlantic cod (
Gadus morhua
). Int J Food Sci Technol 2021. [DOI: 10.1111/ijfs.14655] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Wenhui Zhu
- College of Food Science and Engineering Bohai University Jinzhou Liaoning 121013 China
- National & Local Joint Engineering Research Center of Storage Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products Jinzhou Liaoning 121013 China
- The Fresh Food Storage and Processing Technology Research Institute of Liaoning Provincial Universities Jinzhou Liaoning 121013 China
| | - Wei He
- College of Food Science and Engineering Bohai University Jinzhou Liaoning 121013 China
- National & Local Joint Engineering Research Center of Storage Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products Jinzhou Liaoning 121013 China
- The Fresh Food Storage and Processing Technology Research Institute of Liaoning Provincial Universities Jinzhou Liaoning 121013 China
| | - Fei Wang
- College of Food Science and Engineering Bohai University Jinzhou Liaoning 121013 China
- National & Local Joint Engineering Research Center of Storage Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products Jinzhou Liaoning 121013 China
- The Fresh Food Storage and Processing Technology Research Institute of Liaoning Provincial Universities Jinzhou Liaoning 121013 China
| | - Ying Bu
- College of Food Science and Engineering Bohai University Jinzhou Liaoning 121013 China
- National & Local Joint Engineering Research Center of Storage Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products Jinzhou Liaoning 121013 China
- The Fresh Food Storage and Processing Technology Research Institute of Liaoning Provincial Universities Jinzhou Liaoning 121013 China
| | - Xuepeng Li
- College of Food Science and Engineering Bohai University Jinzhou Liaoning 121013 China
- National & Local Joint Engineering Research Center of Storage Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products Jinzhou Liaoning 121013 China
- The Fresh Food Storage and Processing Technology Research Institute of Liaoning Provincial Universities Jinzhou Liaoning 121013 China
| | - Jianrong Li
- College of Food Science and Engineering Bohai University Jinzhou Liaoning 121013 China
- National & Local Joint Engineering Research Center of Storage Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products Jinzhou Liaoning 121013 China
- The Fresh Food Storage and Processing Technology Research Institute of Liaoning Provincial Universities Jinzhou Liaoning 121013 China
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16
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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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17
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Janežič D, Jäntschi L, Bolboacă SD. Sugars and Sweeteners: Structure, Properties and In Silico Modeling. Curr Med Chem 2020; 27:5-22. [PMID: 30259809 DOI: 10.2174/0929867325666180926144401] [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: 12/12/2016] [Revised: 01/15/2018] [Accepted: 03/09/2018] [Indexed: 11/22/2022]
Abstract
Several studies report the effects of excessive use of sugars and sweeteners in the diet. These include obesity, cardiac diseases, diabetes, and even lymphomas, leukemias, cancers of the bladder and brain, chronic fatigue syndrome, Parkinson's disease, Alzheimer's disease, multiple sclerosis, autism, and systemic lupus. On the other hand, each sugar and sweetener has a distinct metabolic assimilation process, and its chemical structure plays an important role in this process. Several scientific papers present the biological effects of the sugars and sweeteners in relation to their chemical structure. One important issue dealing with the sugars is the degree of similarity in their structures, focusing mostly on optical isomerism. Finding and developing new sugars and sweeteners with desired properties is an emerging research area, in which in silico approaches play an important role.
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Affiliation(s)
- Dušanka Janežič
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Koper, Slovenia
| | - Lorentz Jäntschi
- Department of Physics and Chemistry, Technical University of Cluj-Napoca, Cluj-Napoca, Romania.,Chemistry Doctoral School, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Sorana D Bolboacă
- Department of Medical Informatics and Biostatistics, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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18
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Abstract
Taste sensation is initiated in sensory cells within the taste buds (taste cells), in which the cooperation of many signaling molecules leads to the coding and transmission of information on the quality and intensity of taste to the afferent gustatory nerves. Here, we describe our method for inducing foreign gene expression in taste cells of fungiform papillae in a living mouse using a recombinant adeno-associated virus (AAV) vector, enabling us to study and control the function of a gene product in vivo. Among the serotypes tested to date, only AAV-DJ, a synthetic serotype, can transduce taste cells in vivo. We also describe how to validate intragemmal foreign gene expression in fungiform taste buds using an immunohistochemical approach.
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Affiliation(s)
- Akiyuki Taruno
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
| | - Makiko Kashio
- Department of Physiology, Aichi Medical University, Nagakute, Japan
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19
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Xu J, Lewandowski BC, Miyazawa T, Shoji Y, Yee K, Bryant BP. Spilanthol Enhances Sensitivity to Sodium in Mouse Taste Bud Cells. Chem Senses 2019; 44:91-103. [PMID: 30364996 PMCID: PMC6350677 DOI: 10.1093/chemse/bjy069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Overconsumption of NaCl has been linked to increased hypertension-related morbidity. Compounds that can enhance NaCl responses in taste cells could help reduce human NaCl consumption without sacrificing perceived saltiness. Spilanthol is an unsaturated alkylamide isolated from the Jambu plant (Acmella oleracea) that can induce tingling, pungency, and numbing in the mouth. Structurally similar fatty acid amides, such as sanshool, elicit numbing and tingling sensations by inhibiting 2-pore-domain potassium leak channels on trigeminal sensory neurons. Even when insufficient to induce action potential firing, leak current inhibition causes depolarization and increased membrane resistance, which combine to make cells more sensitive to subsequent depolarizing stimuli, such as NaCl. Using calcium imaging, we tested whether spilanthol alters sensitivity to NaCl in isolated circumvallate taste bud cells and trigeminal sensory neurons of mice (Mus musculus). Micromolar spilanthol elicited little to no response in taste bud cells or trigeminal neurons. These same perithreshold concentrations of spilanthol significantly enhanced responses to NaCl (140 and 200 mM) in taste bud cells. Trigeminal neurons, however, exhibited response enhancement only at the highest concentrations of NaCl and spilanthol tested. Using a combination of potassium depolarization, immunohistochemistry, and Trpm5-GFP and Tas1r3-GFP mice to characterize taste bud cells by type, we found spilanthol enhancement of NaCl responses most prevalent in NaCl-responsive type III cells, and commonly observed in NaCl-responsive type II cells. Our results indicate that spilanthol enhances NaCl responses in taste bud cells and point to a family of compounds that may have utility as salty taste enhancers.
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Affiliation(s)
- Jiang Xu
- Monell Chemical Senses Center, Philadelphia, PA , USA
| | | | | | - Yasutaka Shoji
- Ogawa & Co. Ltd., Nihonbashi Honcho Chuo-ku, Tokyo, Japan
| | - Karen Yee
- Monell Chemical Senses Center, Philadelphia, PA , USA
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20
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Abstract
Taste buds are the dedicated sensory end organs of taste, comprising a complex and evolving profile of signaling elements. The sensation and ultimate perception of taste depends on the expression of a diverse array of receptors and channels that sense their respective tastes. Receptor regulation is a recognized and well-studied phenomenon in many systems, observed in opioid addiction, insulin resistance and caffeine tolerance. Results from human sensory studies suggest that receptor sensitivity or expression level may decrease after chronic exposure to respective tastants through diet. We review data supporting the theory that taste receptors may become downregulated with exposure to a specific tastant, along with presenting data from a small pilot study, showing the impact of long-term tastant exposure on taste receptor expression in mice. Mice treated with monosodium salt monohydrate (MSG), saccharin and NaCl (typically appetitive tastes) all displayed a significant decrease in mRNA expression for respective umami, sweet and salty receptors/sensory channels. Reduced sensitivity to appetitive tastes may promote overconsumption of foods high in such stimuli.
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21
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Zhou L, Huang W, Xu Y, Gao C, Zhang T, Guo M, Liu Y, Ding J, Qin L, Xu Z, Long Y, Xu Y. Sweet Taste Receptors Mediated ROS-NLRP3 Inflammasome Signaling Activation: Implications for Diabetic Nephropathy. J Diabetes Res 2018; 2018:7078214. [PMID: 29675433 PMCID: PMC5838486 DOI: 10.1155/2018/7078214] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 12/07/2017] [Accepted: 12/25/2017] [Indexed: 01/14/2023] Open
Abstract
Previous studies demonstrated that ROS-NLRP3 inflammasome signaling activation was involved in the pathogenesis of diabetic nephropathy (DN). Recent research has shown that sweet taste receptors (STRs) are important sentinels of innate immunity. Whether high glucose primes ROS-NLRP3 inflammasome signaling via STRs is unclear. In this study, diabetic mouse model was induced by streptozotocin (STZ) in vivo; mouse glomerular mesangial cells (GMCs) and human proximal tubular cells were stimulated by high glucose (10, 20, and 30 mmol/L) in vitro; STR inhibitor lactisole was used as an intervention reagent to evaluate the role and mechanism of the STRs in the pathogenesis of DN. Our results showed that the expression of STRs and associated signaling components (Gα-gustducin, PLCβ2, and TRPM5) was obviously downregulated under the condition of diabetes in vivo and in vitro. Furthermore, lactisole significantly mitigated the production of intracellular ROS and reversed the high glucose-induced decrease of Ca2+ and the activation of NLRP3 inflammasome signaling in vitro (p < 0.05). These combined results support the hypothesis that STRs could be involved in the activation of ROS-NLRP3 inflammasome signaling in the pathogenesis of DN, suggesting that STRs may act as new therapeutic targets of DN.
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Affiliation(s)
- Luping Zhou
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- The Graduate School of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Wei Huang
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
| | - Youhua Xu
- Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
| | - Chenlin Gao
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
| | - Ting Zhang
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- The Graduate School of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Man Guo
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- The Graduate School of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Yan Liu
- Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China
| | - Jingya Ding
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- The Graduate School of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Ludan Qin
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- The Graduate School of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Zihao Xu
- The Graduate School of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Yang Long
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Yong Xu
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Southwest Medical University, Luzhou, Sichuan 646000, China
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22
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Sukumaran SK, Lewandowski BC, Qin Y, Kotha R, Bachmanov AA, Margolskee RF. Whole transcriptome profiling of taste bud cells. Sci Rep 2017; 7:7595. [PMID: 28790351 PMCID: PMC5548921 DOI: 10.1038/s41598-017-07746-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 07/03/2017] [Indexed: 12/15/2022] Open
Abstract
Analysis of single-cell RNA-Seq data can provide insights into the specific functions of individual cell types that compose complex tissues. Here, we examined gene expression in two distinct subpopulations of mouse taste cells: Tas1r3-expressing type II cells and physiologically identified type III cells. Our RNA-Seq libraries met high quality control standards and accurately captured differential expression of marker genes for type II (e.g. the Tas1r genes, Plcb2, Trpm5) and type III (e.g. Pkd2l1, Ncam, Snap25) taste cells. Bioinformatics analysis showed that genes regulating responses to stimuli were up-regulated in type II cells, while pathways related to neuronal function were up-regulated in type III cells. We also identified highly expressed genes and pathways associated with chemotaxis and axon guidance, providing new insights into the mechanisms underlying integration of new taste cells into the taste bud. We validated our results by immunohistochemically confirming expression of selected genes encoding synaptic (Cplx2 and Pclo) and semaphorin signalling pathway (Crmp2, PlexinB1, Fes and Sema4a) components. The approach described here could provide a comprehensive map of gene expression for all taste cell subpopulations and will be particularly relevant for cell types in taste buds and other tissues that can be identified only by physiological methods.
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Affiliation(s)
- Sunil K Sukumaran
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA, 19104, USA
| | - Brian C Lewandowski
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA, 19104, USA
| | - Yumei Qin
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA, 19104, USA.,College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, 310018, P.R. China
| | - Ramana Kotha
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA, 19104, USA
| | | | - Robert F Margolskee
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA, 19104, USA.
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23
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Taruno A, Kashio M, Sun H, Kobayashi K, Sano H, Nambu A, Marunaka Y. Adeno-Associated Virus-Mediated Gene Transfer into Taste Cells In Vivo. Chem Senses 2016; 42:69-78. [PMID: 27940927 DOI: 10.1093/chemse/bjw101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The sense of taste is achieved by cooperation of many signaling molecules expressed in taste cells, which code and transmit information on quality and intensity of taste to the nervous system. Viral vector-mediated gene transfer techniques have been proven to be useful to study and control function of a gene product in vivo However, there is no transduction method for taste cells in live animals. Here, we have established a method for inducing foreign gene expression in mouse taste cells in vivo by recombinant adeno-associated virus (AAV) vector. First, using enhanced green fluorescent protein (EGFP) as a reporter, we screened 6 AAV serotypes along with a recombinant lentivirus vector for their ability to transduce taste cells. One week after viral injection into the submucosa of the tongue, EGFP expression in fungiform taste cells was observed only in animals injected with AAV-DJ, a synthetic serotype. Next, time course of AAV-DJ-mediated EGFP expression in fungiform taste cells was evaluated. Intragemmal EGFP signals appeared after a delay, rapidly increased until 7 days postinjection, and gradually decreased over the next few weeks probably because of the cell turnover. Finally, the taste cell types susceptible to AAV-DJ transduction were characterized. EGFP expression was observed in PLCβ2-immunoreactive type II and aromatic l-amino acid decarboxylase (AADC)-immunoreactive type III taste cells as well as in cells immunonegative for both PLCβ2 and AADC, demonstrating that AAV-DJ does not discriminate functional taste cell types. In conclusion, the method established in this study will be a promising tool to study the mechanism of taste.
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Affiliation(s)
- Akiyuki Taruno
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Makiko Kashio
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Hongxin Sun
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8585, Japan.,Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan
| | - Hiromi Sano
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan.,Division of System Neurophysiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8585, Japan and
| | - Atsushi Nambu
- Section of Viral Vector Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8585, Japan.,Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan.,Division of System Neurophysiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8585, Japan and
| | - Yoshinori Marunaka
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.,Department of Bio-Ionomics, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
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Leone S, Pica A, Merlino A, Sannino F, Temussi PA, Picone D. Sweeter and stronger: enhancing sweetness and stability of the single chain monellin MNEI through molecular design. Sci Rep 2016; 6:34045. [PMID: 27658853 PMCID: PMC5034325 DOI: 10.1038/srep34045] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 09/07/2016] [Indexed: 11/22/2022] Open
Abstract
Sweet proteins are a family of proteins with no structure or sequence homology, able to elicit a sweet sensation in humans through their interaction with the dimeric T1R2-T1R3 sweet receptor. In particular, monellin and its single chain derivative (MNEI) are among the sweetest proteins known to men. Starting from a careful analysis of the surface electrostatic potentials, we have designed new mutants of MNEI with enhanced sweetness. Then, we have included in the most promising variant the stabilising mutation E23Q, obtaining a construct with enhanced performances, which combines extreme sweetness to high, pH-independent, thermal stability. The resulting mutant, with a sweetness threshold of only 0.28 mg/L (25 nM) is the strongest sweetener known to date. All the new proteins have been produced and purified and the structures of the most powerful mutants have been solved by X-ray crystallography. Docking studies have then confirmed the rationale of their interaction with the human sweet receptor, hinting at a previously unpredicted role of plasticity in said interaction.
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Affiliation(s)
- Serena Leone
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy
| | - Andrea Pica
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy
| | - Antonello Merlino
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy
| | - Filomena Sannino
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy
| | - Piero Andrea Temussi
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy.,Department of Basic and Clinical Neurosciences, King's College London, London SE5 9RX, UK
| | - Delia Picone
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy
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