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Yoshida R, Ninomiya Y. Mechanisms and Functions of Sweet Reception in Oral and Extraoral Organs. Int J Mol Sci 2024; 25:7398. [PMID: 39000505 PMCID: PMC11242429 DOI: 10.3390/ijms25137398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/27/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024] Open
Abstract
The oral detection of sugars relies on two types of receptor systems. The first is the G-protein-coupled receptor TAS1R2/TAS1R3. When activated, this receptor triggers a downstream signaling cascade involving gustducin, phospholipase Cβ2 (PLCβ2), and transient receptor potential channel M5 (TRPM5). The second type of receptor is the glucose transporter. When glucose enters the cell via this transporter, it is metabolized to produce ATP. This ATP inhibits the opening of KATP channels, leading to cell depolarization. Beside these receptor systems, sweet-sensitive taste cells have mechanisms to regulate their sensitivity to sweet substances based on internal and external states of the body. Sweet taste receptors are not limited to the oral cavity; they are also present in extraoral organs such as the gastrointestinal tract, pancreas, and brain. These extraoral sweet receptors are involved in various functions, including glucose absorption, insulin release, sugar preference, and food intake, contributing to the maintenance of energy homeostasis. Additionally, sweet receptors may have unique roles in certain organs like the trachea and bone. This review summarizes past and recent studies on sweet receptor systems, exploring the molecular mechanisms and physiological functions of sweet (sugar) detection in both oral and extraoral organs.
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Affiliation(s)
- Ryusuke Yoshida
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Yuzo Ninomiya
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
- Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
- Monell Chemical Senses Center, Philadelphia, PA 19104, USA
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Shon WJ, Seong H, Song JW, Shin DM. Taste receptor type 1 member 3 is required for the fertility of male mice. Heliyon 2024; 10:e24577. [PMID: 38312691 PMCID: PMC10835302 DOI: 10.1016/j.heliyon.2024.e24577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/28/2023] [Accepted: 01/10/2024] [Indexed: 02/06/2024] Open
Abstract
Male infertility is a global health concern. However, its underlying pathophysiology remains unclear. Taste receptor type 1 member 3 (TAS1R3) is highly expressed in the testes, indicating its potential involvement in male fertility. Using wild-type and Tas1r3 knockout (KO) mice, we investigated whether TAS1R3 modulates male reproductive function. Tas1r3 KO mice exhibited reduced male fertility compared to WT mice, with fewer live pups per litter and a delayed first litter. Testicular transcriptome analysis indicated suppressed PKA/CREB/StAR signaling-mediated testosterone synthesis in Tas1r3 KO mice. In silico single-cell RNA sequencing revealed considerably higher Tas1r3 expression in Leydig cells than in other testicular cell subtypes. An in vitro study validated that Tas1r3 knockdown downregulated the expression of Creb1 and steroidogenic genes in Leydig cells. Our results suggest that testicular TAS1R3 is intricately involved in male reproduction via the PKA/CREB/StAR signaling pathway, highlighting its potential as a promising target for addressing male infertility.
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Affiliation(s)
- Woo-Jeong Shon
- Research Institute of Human Ecology, Seoul National University, Gwanak-gu, Seoul 08826, Republic of Korea
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hobin Seong
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jae Won Song
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Dong-Mi Shin
- Research Institute of Human Ecology, Seoul National University, Gwanak-gu, Seoul 08826, Republic of Korea
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-gu, Seoul 08826, Republic of Korea
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Lee KH, Song JW, Kim CS, Seong H, Shin DM, Shon WJ. Taste receptor type 1 member 3 mediates diet-induced cognitive impairment in mice. Life Sci 2023; 334:122194. [PMID: 37865176 DOI: 10.1016/j.lfs.2023.122194] [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: 05/22/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
AIMS Long-term consumption of a western diet (WD), which is characterized by high intake of saturated fats and sugary drinks, causes cognitive impairment. However, the molecular mechanism by which WD induces cognitive impairment remains unclear. Taste receptor type 1 member 3 (TAS1R3), activated by ligands of WD, is expressed in extra-oral tissues, including the brain, and particularly in the hippocampus. This study investigated whether TAS1R3 regulates WD-induced cognitive impairment in mice. MAIN METHODS Male C57BL/6J wild-type (WT) and Tas1r3 knock-out (KO) mice were fed either a normal diet (ND) or WD for 18 weeks. Cognitive functions were assessed using novel object recognition and Barnes maze tests. The mechanisms underlying WD-induced cognitive impairment were assessed using RNA-sequencing and bioinformatics analysis. KEY FINDINGS Cognitive impairment was observed in WT mice fed WD (WT-WD) compared with WT-ND mice. Conversely, mice lacking TAS1R3 were not cognitively impaired even under long-term WD feeding. Hippocampal transcriptome analysis revealed upregulated AMP-activated protein kinase (AMPK) signaling and increased AMPK-targeted sirtuin 3 expression in KO-WD mice. Pathway enrichment analysis showed that response to oxidative stress was downregulated, whereas neurogenesis was upregulated in dentate gyrus of KO-WD mice. In vitro studies validated the findings, indicating that Tas1r3 knockdown directly upregulated decreased sirtuin 3 expression, its downstream genes-related to oxidative stress, and apoptosis induced by WD condition in hippocampal neuron cells. SIGNIFICANCE TAS1R3 acts as a critical mediator of WD-induced cognitive impairment in mice, thereby offering potential as a novel therapeutic target to prevent WD-induced cognitive impairment.
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Affiliation(s)
- Keon-Hee Lee
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea; Department of Environmental Health Sciences, Graduate School of Public Health, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae Won Song
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea
| | - Chong-Su Kim
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea
| | - Hobin Seong
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea
| | - Dong-Mi Shin
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
| | - Woo-Jeong Shon
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
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Song JW, Lee KH, Seong H, Shin DM, Shon WJ. Taste receptor type 1 member 3 enables western diet-induced anxiety in mice. BMC Biol 2023; 21:243. [PMID: 37926812 PMCID: PMC10626698 DOI: 10.1186/s12915-023-01723-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 10/03/2023] [Indexed: 11/07/2023] Open
Abstract
BACKGROUND Accumulating evidence supports that the Western diet (WD), a diet high in saturated fat and sugary drinks, contributes to the pathogenesis of anxiety disorders, which are the most prevalent mental disorders worldwide. However, the underlying mechanisms by which WD causes anxiety remain unclear. Abundant expression of taste receptor type 1 member 3 (TAS1R3) has been identified in the hypothalamus, a key brain area involved in sensing peripheral nutritional signals and regulating anxiety. Thus, we investigated the influence of excessive WD intake on anxiety and mechanisms by which WD intake affects anxiety development using wild-type (WT) and Tas1r3 deficient (Tas1r3-/-) mice fed a normal diet (ND) or WD for 12 weeks. RESULTS WD increased anxiety in male WT mice, whereas male Tas1r3-/- mice were protected from WD-induced anxiety, as assessed by open field (OF), elevated plus maze (EPM), light-dark box (LDB), and novelty-suppressed feeding (NSF) tests. Analyzing the hypothalamic transcriptome of WD-fed WT and Tas1r3-/- mice, we found 1,432 genes significantly up- or down-regulated as a result of Tas1r3 deficiency. Furthermore, bioinformatic analysis revealed that the CREB/BDNF signaling-mediated maintenance of neuronal regeneration, which can prevent anxiety development, was enhanced in WD-fed Tas1r3-/- mice compared with WD-fed WT mice. Additionally, in vitro studies further confirmed that Tas1r3 knockdown prevents the suppression of Creb1 and of CREB-mediated BDNF expression caused by high levels of glucose, fructose, and palmitic acid in hypothalamic neuronal cells. CONCLUSIONS Our results imply that TAS1R3 may play a key role in WD-induced alterations in hypothalamic functions, and that inhibition of TAS1R3 overactivation in the hypothalamus could offer therapeutic targets to alleviate the effects of WD on anxiety.
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Affiliation(s)
- Jae Won Song
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-Gu, Seoul, 08826, Republic of Korea
| | - Keon-Hee Lee
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-Gu, Seoul, 08826, Republic of Korea
| | - Hobin Seong
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-Gu, Seoul, 08826, Republic of Korea
| | - Dong-Mi Shin
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-Gu, Seoul, 08826, Republic of Korea.
- Research Institute of Human Ecology, Seoul National University, Gwanak-Gu, Seoul, 08826, Republic of Korea.
| | - Woo-Jeong Shon
- Department of Food and Nutrition, Seoul National University College of Human Ecology, Gwanak-Gu, Seoul, 08826, Republic of Korea.
- Research Institute of Human Ecology, Seoul National University, Gwanak-Gu, Seoul, 08826, Republic of Korea.
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Kouakou YI, Lee RJ. Interkingdom Detection of Bacterial Quorum-Sensing Molecules by Mammalian Taste Receptors. Microorganisms 2023; 11:1295. [PMID: 37317269 DOI: 10.3390/microorganisms11051295] [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: 04/25/2023] [Revised: 05/11/2023] [Accepted: 05/13/2023] [Indexed: 06/16/2023] Open
Abstract
Bitter and sweet taste G protein-coupled receptors (known as T2Rs and T1Rs, respectively) were originally identified in type II taste cells on the tongue, where they signal perception of bitter and sweet tastes, respectively. Over the past ~15 years, taste receptors have been identified in cells all over the body, demonstrating a more general chemosensory role beyond taste. Bitter and sweet taste receptors regulate gut epithelial function, pancreatic β cell secretion, thyroid hormone secretion, adipocyte function, and many other processes. Emerging data from a variety of tissues suggest that taste receptors are also used by mammalian cells to "eavesdrop" on bacterial communications. These receptors are activated by several quorum-sensing molecules, including acyl-homoserine lactones and quinolones from Gram-negative bacteria such as Pseudomonas aeruginosa, competence stimulating peptides from Streptococcus mutans, and D-amino acids from Staphylococcus aureus. Taste receptors are an arm of immune surveillance similar to Toll-like receptors and other pattern recognition receptors. Because they are activated by quorum-sensing molecules, taste receptors report information about microbial population density based on the chemical composition of the extracellular environment. This review summarizes current knowledge of bacterial activation of taste receptors and identifies important questions remaining in this field.
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Affiliation(s)
- Yobouet Ines Kouakou
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert J Lee
- Department of Otorhinolaryngology and Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Mei Y, Li Y, Cheng Y, Gao L. The effect of gastric bypass surgery on cognitive function of Alzheimer's disease and the role of GLP1-SGLT1 pathway. Exp Neurol 2023; 363:114377. [PMID: 36893833 DOI: 10.1016/j.expneurol.2023.114377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/20/2023] [Accepted: 03/04/2023] [Indexed: 03/09/2023]
Abstract
OBJECTIVE Gastric bypass surgery has been shown to improve metabolic profiles via GLP1, which may also have cognitive benefits for Alzheimer's disease (AD) patients. However, the exact mechanism requires further investigation. METHODS Roux-en-Y gastric bypass or sham surgery was performed on APP/PS1/Tau triple transgenic mice (an AD mice model) or wild type C57BL/6 mice. Morris Water Maze (MWM) test was used to evaluate the cognitive function of mice and animal tissue samples were obtained for measurements two months after the surgery. Additionally, STC-1 intestine cells were treated with siTAS1R2 and siSGLT1, and HT22 nerve cells were treated with Aβ, siGLP1R, GLP1 and siSGLT1 in vitro to explore the role of GLP1-SGLT1 related signaling pathway in cognitive function. RESULTS The MWM test showed that bypass surgery significantly improved cognitive function in AD mice as measured by navigation and spatial probe tests. Moreover, bypass surgery reversed neurodegeneration, down-regulated hyperphosphorylation of Tau protein and Aβ deposition, improved glucose metabolism, and up-regulated the expression of GLP1, SGLT1, and TAS1R2/3 in the hippocampus. Furthermore, GLP1R silencing down-regulated SGLT1 expression, whereas SGLT1 silencing increased Tau protein deposition and exacerbated dysregulated of glucose metabolism in HT22 cells. However, RYGB did not alter the level of GLP1 secretion in the brainstem (where central GLP1 is mainly produced). Additionally, GLP1 expression was upregulated by RYGB via TAS1R2/3-SGLT1 activation sequentially in the small intestine. CONCLUSION RYGB surgery could improve cognition function in AD mice through facilitating glucose metabolism and reducing Tau phosphorylation and Aβ deposition in the hippocampus, mediated by peripheral serum GLP1 activation of SGLT1 in the brain. Furthermore, RYGB increased GLP1 expression through sequential activation of TAS1R2/TAS1R3 and SGLT1 in the small intestine.
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Affiliation(s)
- Yingna Mei
- Department of Endocrinology & Metabolism, Renmin Hospital of Wuhan University, China
| | - Yubing Li
- Department of Endocrinology & Metabolism, Renmin Hospital of Wuhan University, China
| | - Yanxiang Cheng
- Department of Obstetrics & Gynecology, Renmin Hospital of Wuhan University, China.
| | - Ling Gao
- Department of Endocrinology & Metabolism, Renmin Hospital of Wuhan University, China.
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Morales-Ríos EI, García-Machorro J, Briones-Aranda A, Gómez-Pliego R, Espinosa-Raya J. Effect of Long-term Intake of Nutritive and Non-nutritive Sweeteners on Metabolic Health and Cognition in Adult Male Rats. J Med Food 2022; 25:1059-1065. [PMID: 35951019 DOI: 10.1089/jmf.2022.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study evaluated the effects of long-term intake of nutritive sweeteners (NSs) and non-nutritive sweeteners (NNSs) on body weight, food and energy intake, blood pressure, metabolic parameters, and memory retention in rats. Sixty male Sprague-Dawley rats were randomly divided into six groups (n = 10 per group): control (water),10% sucrose (SUC), aspartame (ASP), sucralose (SCA), stevia (STV), and 5% xylitol (XYL). Pure NSs (SUC and XYL) and NNSs were added to the drinking water for 18 weeks. ASP, SCA, and STV dosage was based on the estimated daily intake limit: 4.1, 2.0, and 3.4 mg/kg/day, respectively. Chronic access to NNSs did not result in any difference in total weight gain of the rats, while it was significantly elevated in the SUC group compared with the control and NNSs groups. Food intake was significantly lower in all NNSs groups compared with SUC and control groups. Sweetened beverage intake volumes were significantly diminished in all NNSs groups compared with intake in SUC and control groups. Total calories consumed were lower for the STV and XYL groups compared with all other groups. Blood pressure and glucose metabolism did not differ significantly between the groups. All sweeteners increased total cholesterol, low-density lipoprotein, and triglyceride levels. Short-term memory was significantly impaired in the ASP group in the novel object recognition task, while long-term memory was impaired in SUC and STV groups. These metabolic and behavioral results suggest that the long-term intake of NSs or NNSs can be associated with peripheral and central effects.
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Affiliation(s)
- Emmanuel Iván Morales-Ríos
- Laboratorio de Neurofarmacología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Jazmín García-Machorro
- Laboratorio de Medicina de Conservación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Alfredo Briones-Aranda
- Laboratorio de Farmacología, Facultad de Medicina Humana, Universidad Autónoma de Chiapas, Tuxtla Gutiérrez Chiapas, México
| | - Raquel Gómez-Pliego
- Sección de Ciencias de la Salud Humana, Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Estado de México, México
| | - Judith Espinosa-Raya
- Laboratorio de Neurofarmacología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
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Leysen H, Walter D, Clauwaert L, Hellemans L, van Gastel J, Vasudevan L, Martin B, Maudsley S. The Relaxin-3 Receptor, RXFP3, Is a Modulator of Aging-Related Disease. Int J Mol Sci 2022; 23:4387. [PMID: 35457203 PMCID: PMC9027355 DOI: 10.3390/ijms23084387] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 12/12/2022] Open
Abstract
During the aging process our body becomes less well equipped to deal with cellular stress, resulting in an increase in unrepaired damage. This causes varying degrees of impaired functionality and an increased risk of mortality. One of the most effective anti-aging strategies involves interventions that combine simultaneous glucometabolic support with augmented DNA damage protection/repair. Thus, it seems prudent to develop therapeutic strategies that target this combinatorial approach. Studies have shown that the ADP-ribosylation factor (ARF) GTPase activating protein GIT2 (GIT2) acts as a keystone protein in the aging process. GIT2 can control both DNA repair and glucose metabolism. Through in vivo co-regulation analyses it was found that GIT2 forms a close coexpression-based relationship with the relaxin-3 receptor (RXFP3). Cellular RXFP3 expression is directly affected by DNA damage and oxidative stress. Overexpression or stimulation of this receptor, by its endogenous ligand relaxin 3 (RLN3), can regulate the DNA damage response and repair processes. Interestingly, RLN3 is an insulin-like peptide and has been shown to control multiple disease processes linked to aging mechanisms, e.g., anxiety, depression, memory dysfunction, appetite, and anti-apoptotic mechanisms. Here we discuss the molecular mechanisms underlying the various roles of RXFP3/RLN3 signaling in aging and age-related disorders.
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Affiliation(s)
- Hanne Leysen
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Deborah Walter
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Lore Clauwaert
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Lieselot Hellemans
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Jaana van Gastel
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
- SGS Belgium, Intercity Business Park, Generaal De Wittelaan 19-A5, 2800 Mechelen, Belgium
| | | | - Bronwen Martin
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium;
| | - Stuart Maudsley
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
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Du B, Zhang Y, Liang M, Du Z, Li H, Fan C, Zhang H, Jiang Y, Bi X. N6-methyladenosine (m6A) modification and its clinical relevance in cognitive dysfunctions. Aging (Albany NY) 2021; 13:20716-20737. [PMID: 34461609 PMCID: PMC8436914 DOI: 10.18632/aging.203457] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 08/02/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND N6 adenosine methylation (m6A) is the most abundant internal RNA modification in eukaryotic cells. Dysregulation of m6A has been associated with the perturbations of cell proliferation and cell death in different diseases. However, the roles of m6A in the neurodegenerative process and cognitive dysfunction are unclear. METHODS We systematically investigated the molecular alterations of m6A regulators and their clinical relevance with cognitive dysfunctions using published datasets of Alzheimer's Disease (AD), vascular dementia, and mild cognitive impairment (MCI). FINDINGS The expressions of m6A regulators vary in different tissues and closely correlate with neurodegenerative pathways. We identified co-expressive m6A regulators SNRPG and SNRPD2 as potential biomarkers to predict transformation from MCI to AD. Moreover, we explored correlations between Apolipoprotein E4 and m6A methylations. INTERPRETATION Collectively, these findings suggest that m6A methylations as potential biomarkers and therapeutic targets for cognitive dysfunction. FUNDING This work was supported by the National Natural Science Foundation of China (81871040) and the Shanghai Health System Talent Training Program (2018BR29).
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Affiliation(s)
- Bingying Du
- Department of Neurology, Shanghai Changhai Hospital, The Second Military Medical University, Shanghai, PR China
| | - Yanbo Zhang
- Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Meng Liang
- Department of Neurology, Shanghai Changhai Hospital, The Second Military Medical University, Shanghai, PR China
| | - Zengkan Du
- Faculty of Basic Medical Sciences, The Second Military Medical University, Shanghai, PR China
| | - Haibo Li
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Cunxiu Fan
- Department of Neurology, Shanghai Changhai Hospital, The Second Military Medical University, Shanghai, PR China
| | - Hailing Zhang
- Department of Neurology, Shanghai Changhai Hospital, The Second Military Medical University, Shanghai, PR China
| | - Yan Jiang
- Department of Oral and Maxillofacial-Head Neck Oncology, Shanghai Ninth People's Hospital College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Xiaoying Bi
- Department of Neurology, Shanghai Changhai Hospital, The Second Military Medical University, Shanghai, PR China
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Abstract
Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.
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Carey RM, Lee RJ. Taste Receptors in Upper Airway Innate Immunity. Nutrients 2019; 11:nu11092017. [PMID: 31466230 PMCID: PMC6770031 DOI: 10.3390/nu11092017] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/19/2019] [Accepted: 08/22/2019] [Indexed: 02/07/2023] Open
Abstract
Taste receptors, first identified on the tongue, are best known for their role in guiding our dietary preferences. The expression of taste receptors for umami, sweet, and bitter have been demonstrated in tissues outside of the oral cavity, including in the airway, brain, gastrointestinal tract, and reproductive organs. The extra-oral taste receptor chemosensory pathways and the endogenous taste receptor ligands are generally unknown, but there is increasing data suggesting that taste receptors are involved in regulating some aspects of innate immunity, and may potentially control the composition of the nasal microbiome in healthy individuals or patients with upper respiratory diseases like chronic rhinosinusitis (CRS). For this reason, taste receptors may serve as potential therapeutic targets, providing alternatives to conventional antibiotics. This review focuses on the physiology of sweet (T1R) and bitter (T2R) taste receptors in the airway and their activation by secreted bacterial products. There is particular focus on T2R38 in sinonasal ciliated cells, as well as the sweet and bitter receptors found on specialized sinonasal solitary chemosensory cells. Additionally, this review explores the impact of genetic variations in these receptors on the differential susceptibility of patients to upper airway infections, such as CRS.
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Affiliation(s)
- Ryan M Carey
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert J Lee
- Department of Otorhinolaryngology and Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Behrens M, Meyerhof W. A role for taste receptors in (neuro)endocrinology? J Neuroendocrinol 2019; 31:e12691. [PMID: 30712315 DOI: 10.1111/jne.12691] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/14/2019] [Accepted: 01/29/2019] [Indexed: 12/12/2022]
Abstract
The sense of taste is positioned at the forefront when it comes to the interaction of our body with foodborne chemicals. However, the role of our taste system, and in particular its associated taste receptors, is not limited to driving food preferences leading to ingestion or rejection before other organs take over responsibility for nutrient digestion, absorption and metabolic regulation. Taste sensory elements do much more. On the one hand, extra-oral taste receptors from the brain to the gut continue to sense nutrients and noxious substances after ingestion and, on the other hand, the nutritional state feeds back on the taste system. This intricate regulatory network is orchestrated by endocrine factors that are secreted in response to taste receptor signalling and, in turn regulate the taste receptor cells themselves. The present review summarises current knowledge on the endocrine regulation of the taste perceptual system and the release of hunger/satiety regulating factors by gastrointestinal taste receptors. Furthermore, the regulation of blood glucose levels via the activation of pancreatic sweet taste receptors and subsequent insulin secretion, as well as the influence of bitter compounds on thyroid hormone release, is addressed. Finally, the central effects of tastants are discussed briefly.
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Affiliation(s)
- Maik Behrens
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany
| | - Wolfgang Meyerhof
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
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Hendrickx JO, van Gastel J, Leysen H, Santos-Otte P, Premont RT, Martin B, Maudsley S. GRK5 - A Functional Bridge Between Cardiovascular and Neurodegenerative Disorders. Front Pharmacol 2018; 9:1484. [PMID: 30618771 PMCID: PMC6304357 DOI: 10.3389/fphar.2018.01484] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/03/2018] [Indexed: 12/15/2022] Open
Abstract
Complex aging-triggered disorders are multifactorial programs that comprise a myriad of alterations in interconnected protein networks over a broad range of tissues. It is evident that rather than being randomly organized events, pathophysiologies that possess a strong aging component such as cardiovascular diseases (hypertensions, atherosclerosis, and vascular stiffening) and neurodegenerative conditions (dementia, Alzheimer's disease, mild cognitive impairment, Parkinson's disease), in essence represent a subtly modified version of the intricate molecular programs already in place for normal aging. To control such multidimensional activities there are layers of trophic protein control across these networks mediated by so-called "keystone" proteins. We propose that these "keystones" coordinate and interconnect multiple signaling pathways to control whole somatic activities such as aging-related disease etiology. Given its ability to control multiple receptor sensitivities and its broad protein-protein interactomic nature, we propose that G protein coupled receptor kinase 5 (GRK5) represents one of these key network controllers. Considerable data has emerged, suggesting that GRK5 acts as a bridging factor, allowing signaling regulation in pathophysiological settings to control the connectivity between both the cardiovascular and neurophysiological complications of aging.
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Affiliation(s)
- Jhana O. Hendrickx
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
| | - Jaana van Gastel
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
| | - Hanne Leysen
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
| | - Paula Santos-Otte
- Institute of Biophysics, Humboldt-Universitat zu Berlin, Berlin, Germany
| | - Richard T. Premont
- Harrington Discovery Institute, Case Western Reserve University, Cleveland, GA, United States
| | - Bronwen Martin
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
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14
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Dalesio NM, Barreto Ortiz SF, Pluznick JL, Berkowitz DE. Olfactory, Taste, and Photo Sensory Receptors in Non-sensory Organs: It Just Makes Sense. Front Physiol 2018; 9:1673. [PMID: 30542293 PMCID: PMC6278613 DOI: 10.3389/fphys.2018.01673] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/07/2018] [Indexed: 01/28/2023] Open
Abstract
Sensory receptors that detect and respond to light, taste, and smell primarily belong to the G-protein-coupled receptor (GPCR) superfamily. In addition to their established roles in the nose, tongue, and eyes, these sensory GPCRs have been found in many ‘non-sensory' organs where they respond to different physicochemical stimuli, initiating signaling cascades in these extrasensory systems. For example, taste receptors in the airway, and photoreceptors in vascular smooth muscle cells, both cause smooth muscle relaxation when activated. In addition, olfactory receptors are present within the vascular system, where they play roles in angiogenesis as well as in modulating vascular tone. By better understanding the physiological and pathophysiological roles of sensory receptors in non-sensory organs, novel therapeutic agents can be developed targeting these receptors, ultimately leading to treatments for pathological conditions and potential cures for various disease states.
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Affiliation(s)
- Nicholas M Dalesio
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, United States.,Department of Otolaryngology/Head & Neck Surgery, Johns Hopkins University, Baltimore, MD, United States
| | - Sebastian F Barreto Ortiz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Jennifer L Pluznick
- Department of Physiology, Johns Hopkins University, Baltimore, MD, United States
| | - Dan E Berkowitz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, United States
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15
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Maronde E. Trehalose Activates CRE-Dependent Transcriptional Signaling in HT22 Mouse Hippocampal Neuronal Cells: A Central Role for PKA Without cAMP Elevation. Front Mol Neurosci 2018; 11:386. [PMID: 30405349 PMCID: PMC6204353 DOI: 10.3389/fnmol.2018.00386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/26/2018] [Indexed: 01/07/2023] Open
Abstract
Cyclic adenosine 3′,5′monophosphate (cAMP) regulated element binding protein (CREB) is a transcription factor involved in many different signaling processes including memory storage and retrieval. The mouse hippocampal neuronal cell line HT22 is widely used as a model system for neuronal cell death and cellular signal pathway investigations. For the present work a variant of HT22 with a stably expressed CRE-luciferase (CRE-luc) reporter (HT22CRE) is introduced, characterized and used to investigate cAMP-dependent and independent CRE-dependent signal processes. Trehalose (Mykose or 1-α-Glucopyranosyl-1-α-glucopyranosid) is a naturally occurring disaccharide consisting of two α,α′,1,1-glycosidic connected glucose molecules in a wide range of organisms but usually not found in mammals. Trehalose has been shown to activate autophagy, a process which regulates the degradation and recycling of proteins and organelles. The exact processes how trehalose application works on mammalian neuronal cells is not yet understood. The present work shows that trehalose application dose-dependently elevates CRE-luc activity in HT22 cells and acts synergistically with cAMP-elevating agents. In this pathway cAMP-dependent protein kinase (PKA) appears to be the most important factor and the stress kinase p38 and protein tyrosine kinases (PTKs) act as modulators.
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Affiliation(s)
- Erik Maronde
- Department of Medicine, Institute for Cellular and Molecular Anatomy, Goethe University, Frankfurt, Germany
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16
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Cichoń N, Bijak M, Czarny P, Miller E, Synowiec E, Sliwinski T, Saluk-Bijak J. Increase in Blood Levels of Growth Factors Involved in the Neuroplasticity Process by Using an Extremely Low Frequency Electromagnetic Field in Post-stroke Patients. Front Aging Neurosci 2018; 10:294. [PMID: 30319398 PMCID: PMC6168626 DOI: 10.3389/fnagi.2018.00294] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/06/2018] [Indexed: 12/18/2022] Open
Abstract
Background: Neuroplasticity ensures the improvement of functional status in patients after stroke. The aim of this study was to evaluate the effect of extremely low-frequency electromagnetic field therapy (ELF-EMF) on brain plasticity in the rehabilitation of patients after stroke. Methods: Forty-eight patients were divided into two groups underwent the same rehabilitation program, but in the study group, the patients additionally were exposed to a standard series of 10 ELF-EMF treatments. To determine the level of neuroplasticity, we measured the plasma level of the brain-derived neurotrophic factor (BDNF), the vascular-endothelial growth factor, as well as BDNF mRNA expression. Additionally, we determined the molecule levels for hepatocyte growth factor, stem cell factor, stromal cell-derived factor 1α, nerve growth factor β, and leukemia inhibitory factor, using 5plex cytokine panel in plasma. After 4 weeks, during which patients had undergone neurorehabilitation and neurological examinations, we assessed functional recovery using the Barthel Index, Mini-Mental State Examination (MMSE), Geriatric Depression Scale, National Institutes of Health Stroke Scale (NIHSS), and the modified Rankin Scale (mRS). Results: We observed that ELF-EMF significantly increased growth factors and cytokine levels involved in neuroplasticity, as well as promoted an enhancement of functional recovery in post-stroke patients. Additionally, we presented evidence that these effects could be related to the increase of gene expression on the mRNA level. Moreover, a change of BDNF plasma level was positively correlated with the Barthel Index, MMSE, and negatively correlated with GDS. Conclusion: Extremely low-frequency electromagnetic field therapy improves the effectiveness of rehabilitation of post-stroke patients by improving neuroplasticity processes.
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Affiliation(s)
- Natalia Cichoń
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Michał Bijak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, Łódź, Poland
| | - Elżbieta Miller
- Department of Physical Medicine, Medical University of Lodz, Łódź, Poland.,Neurorehabilitation Ward, III General Hospital in Lodz, Łódź, Poland
| | - Ewelina Synowiec
- Laboratory of Medical Genetics, Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Tomasz Sliwinski
- Laboratory of Medical Genetics, Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Joanna Saluk-Bijak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
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17
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Emerging Concepts in Brain Glucose Metabolic Functions: From Glucose Sensing to How the Sweet Taste of Glucose Regulates Its Own Metabolism in Astrocytes and Neurons. Neuromolecular Med 2018; 20:281-300. [DOI: 10.1007/s12017-018-8503-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 07/13/2018] [Indexed: 12/16/2022]
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18
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Freund JR, Lee RJ. Taste receptors in the upper airway. World J Otorhinolaryngol Head Neck Surg 2018; 4:67-76. [PMID: 30035264 PMCID: PMC6051256 DOI: 10.1016/j.wjorl.2018.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 02/26/2018] [Indexed: 02/08/2023] Open
Abstract
Taste receptors were named for their originally-identified expression on the tongue and role in the sensation of taste (gustation). They are now known to be involved in many chemosensory processes outside the tongue. Expression of the receptors for bitter, sweet, and umami was recently identified in many organs, including the brain, airway, gastrointestinal tract, and reproductive systems. We do not yet know the full roles of these receptors in all of these tissues, nor do we know all of the endogenous ligands that activate them. However, taste receptors are emerging as potentially important therapeutic targets. Moreover, they may mediate some off target effects of drugs, as many medications in common clinical use are known to be bitter. The focus of this review is on recent basic and clinical data describing the expression of bitter (T2R) and sweet (T1R) receptors in the airway and their activation by secreted bacterial compounds. These receptors play important roles in innate immune nitric oxide production and antimicrobial peptide secretion, and may be useful targets for stimulating immune responses in the upper respiratory tract via topical therapies. Moreover, genetic variation in these receptors may play a role in the differential susceptibility of patients to certain types of respiratory infections as well as to differential outcomes in patients with chronic rhinosinusitis (CRS). CRS is a syndrome of chronic upper respiratory infection and inflammation and has a significant detrimental impact on patient quality of life. CRS treatment accounts for approximately 20% of adult antibiotic prescriptions and is thus a large driver of the public health crisis of antibiotic resistance. Taste receptors represent a novel class of therapeutic target to potentially stimulate endogenous immune responses and treat CRS patients without conventional antibiotics.
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Affiliation(s)
- Jenna R Freund
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert J Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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