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Sterneder S, Seitz J, Kiefl J, Rottmann E, Liebig M, Blings M, Seilwind S, Zhou Y, Wei J, Guan H, Zhu Q, Kreißl J, Lamottke K, Ley JP, Somoza V. Identification of 4'-Demethyl-3,9-dihydroeucomin as a Bitter-Masking Compound from the Resin of Daemonorops draco. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:20991-20999. [PMID: 39277814 PMCID: PMC11440488 DOI: 10.1021/acs.jafc.4c04583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/17/2024]
Abstract
Masking the bitter taste of foods is one of the key strategies to improve their taste and palatability, particularly in the context of clean labeling, where natural compounds are preferred. Despite the demand, the availability of natural bitter-masking compounds remains limited. Here, we identified the bitter-masking compound 4'-demethyl-3,9-dihydroeucomin (DMDHE) isolated from the resin of Daemonorops draco by means of an activity-guided in vivo (sensory bitterness rating of quinine) and in vitro (cell-based bitter response assays) approach. First, a mean bitter-masking effect of -29.6 ± 6.30% on the bitterness perceived from quinine [10 ppm] was demonstrated for an organic solvent extract of the resin of D. draco (= DD [500 ppm]) in a sensory trial. The results were verified in a cell-based bitter assay in which the bitter taste receptor (TAS2R)-dependent proton secretion serves as an outcome measure of the cellular bitter response in parietal HGT-1 cells. By means of preparative RP-18 high-performance liquid chromatography (HPLC) analysis combined with activity-guided sensory evaluations, the most potent bitter-masking fractions were identified. Subsequent quantitative liquid chromatography/high-resolution mass spectrometry/charged aerosol detection/ultraviolet (LC-HRMS/CAD/UV), NMR analysis, followed by gram-scale synthesis, led to the characterization of DMDHE as bitter-masking homoisoflavanone. DMDHE decreased the sensory bitterness of quinine by 14.8 ± 5.00%. Functional involvement of TAS2R14 was demonstrated by means of a CRISPR-Cas9 approach, which revealed a reduction of the DMDHE-evoked bitter-masking effect by 40.4 ± 9.32% in HGT-1 TAS2R14ko versus HGT-1 wt cells.
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Affiliation(s)
- Sonja Sterneder
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- Vienna Doctoral School in Chemistry (DoSChem), Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- Leibniz Institute for Food Systems Biology, Technical University of Munich, 85354 Freising, Germany
| | - Joachim Seitz
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | | | | | | | | | | | - Yijun Zhou
- Bicoll Biotechnology (Shanghai) Co., Ltd., 201203 Pudong, China
| | - Jianbing Wei
- Bicoll Biotechnology (Shanghai) Co., Ltd., 201203 Pudong, China
| | - Haifeng Guan
- Bicoll Biotechnology (Shanghai) Co., Ltd., 201203 Pudong, China
| | - Qianjin Zhu
- Bicoll Biotechnology (Shanghai) Co., Ltd., 201203 Pudong, China
| | - Johanna Kreißl
- Leibniz Institute for Food Systems Biology, Technical University of Munich, 85354 Freising, Germany
| | - Kai Lamottke
- Bicoll Biotechnology (Shanghai) Co., Ltd., 201203 Pudong, China
- Bicoll GmbH, 82152 Planegg/Martinsried, Germany
| | | | - Veronika Somoza
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- Leibniz Institute for Food Systems Biology, Technical University of Munich, 85354 Freising, Germany
- Chair of Nutritional Systems Biology, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
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2
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Mueller AU, Andersen G, Richter P, Somoza V. Activation of the TRPML1 Ion Channel Induces Proton Secretion in the Human Gastric Parietal Cell Line HGT-1. Int J Mol Sci 2024; 25:8829. [PMID: 39201515 PMCID: PMC11354443 DOI: 10.3390/ijms25168829] [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: 06/25/2024] [Revised: 08/02/2024] [Accepted: 08/10/2024] [Indexed: 09/02/2024] Open
Abstract
The lysosomal Ca2+ channel TRPML1 was found to be responsible for gastric acid secretion in murine gastric parietal cells by inducing the trafficking of H+/K+-ATPase containing tubulovesicles to the apical membrane. Therefore, we hypothesized a similar role of TRPML1 in regulating proton secretion in the immortalized human parietal cell line HGT-1. The primary focus was to investigate the involvement of TRPML1 in proton secretion using the known synthetic agonists ML-SA1 and ML-SA5 and the antagonist ML-SI3 and, furthermore, to identify food-derived compounds that target the channel. Proton secretion stimulated by ML-SA1 was reduced by 122.2 ± 22.7% by the antagonist ML-SI3. The steroid hormone 17β-estradiol, present in animal-derived foods, diminished the proton secretory effect of ML-SA1 by 63.4 ± 14.5%. We also demonstrated a reduction in the proton secretory effects of ML-SA1 and ML-SA5 on TRPML1 knock-down cells. The food-derived compounds sulforaphane and trehalose promoted proton secretion in HGT-1 cells but may act independently of TRPML1. Also, histamine- and caffeine-induced proton secretion were affected by neither the TRPML1 antagonist ML-SI3 nor the TRPML1 knock-down. In summary, the results obtained suggest that the activation of TRPML1 promotes proton secretion in HGT-1 cells, but the channel may not participate in canonical signaling pathways.
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Affiliation(s)
- Alina Ulrike Mueller
- TUM School of Life Sciences Weihenstephan, Technical University of Munich, Alte Akademie 8, 85354 Freising, Germany
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Gaby Andersen
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Phil Richter
- TUM School of Life Sciences Weihenstephan, Technical University of Munich, Alte Akademie 8, 85354 Freising, Germany
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Veronika Somoza
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- Chair of Nutritional Systems Biology, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Josef-Holaubek-Platz 2 (UZA II), 1090 Wien, Austria
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Walser C, Spaccasassi A, Gradl K, Stark TD, Sterneder S, Wolter FP, Achatz F, Frank O, Somoza V, Hofmann T, Dawid C. Human Sensory, Taste Receptor, and Quantitation Studies on Kaempferol Glycosides Derived from Rapeseed/Canola Protein Isolates. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:14830-14843. [PMID: 38888424 PMCID: PMC11228994 DOI: 10.1021/acs.jafc.4c02342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 06/20/2024]
Abstract
Beyond the key bitter compound kaempferol 3-O-(2‴-O-sinapoyl-β-d-sophoroside) previously described in the literature (1), eight further bitter and astringent-tasting kaempferol glucosides (2-9) have been identified in rapeseed protein isolates (Brassica napus L.). The bitterness and astringency of these taste-active substances have been described with taste threshold concentrations ranging from 3.3 to 531.7 and 0.3 to 66.4 μmol/L, respectively, as determined by human sensory experiments. In this study, the impact of 1 and kaempferol 3-O-β-d-glucopyranoside (8) on TAS2R-linked proton secretion by HGT-1 cells was analyzed by quantification of the intracellular proton index. mRNA levels of bitter receptors TAS2R3, 4, 5, 13, 30, 31, 39, 40, 43, 45, 46, 50 and TAS2R8 were increased after treatment with compounds 1 and 8. Using quantitative UHPLC-MS/MSMRM measurements, the concentrations of 1-9 were determined in rapeseed/canola seeds and their corresponding protein isolates. Depending on the sample material, compounds 1, 3, and 5-9 exceeded dose over threshold (DoT) factors above one for both bitterness and astringency in selected protein isolates. In addition, an increase in the key bitter compound 1 during industrial protein production (apart from enrichment) was observed, allowing the identification of the potential precursor of 1 to be kaempferol 3-O-(2‴-O-sinapoyl-β-d-sophoroside)-7-O-β-d-glucopyranoside (3). These results may contribute to the production of less bitter and astringent rapeseed protein isolates through the optimization of breeding and postharvest downstream processing.
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Affiliation(s)
- Christoph Walser
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Andrea Spaccasassi
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Katrin Gradl
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- TUM School of Life Sciences, Technical University of Munich, Alte Akademie 8a, 85354 Freising, Germany
| | - Timo D Stark
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Sonja Sterneder
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- Vienna Doctoral School in Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | | | - Felicia Achatz
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Oliver Frank
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Veronika Somoza
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- ZIEL - Institute for Food & Health, Technical University of Munich, 85354 Freising, Germany
- Chair of Nutritional Systems Biology, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- ZIEL - Institute for Food & Health, Technical University of Munich, 85354 Freising, Germany
- Professorship for Functional Phytometabolomics, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
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Magadán-Corpas P, Ye S, Pérez-Valero Á, McAlpine PL, Valdés-Chiara P, Torres-Bacete J, Nogales J, Villar CJ, Lombó F. Optimized De Novo Eriodictyol Biosynthesis in Streptomyces albidoflavus Using an Expansion of the Golden Standard Toolkit for Its Use in Actinomycetes. Int J Mol Sci 2023; 24:8879. [PMID: 37240225 PMCID: PMC10219347 DOI: 10.3390/ijms24108879] [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: 04/28/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Eriodictyol is a hydroxylated flavonoid displaying multiple pharmaceutical activities, such as antitumoral, antiviral or neuroprotective. However, its industrial production is limited to extraction from plants due to its inherent limitations. Here, we present the generation of a Streptomyces albidoflavus bacterial factory edited at the genome level for an optimized de novo heterologous production of eriodictyol. For this purpose, an expansion of the Golden Standard toolkit (a Type IIS assembly method based on the Standard European Vector Architecture (SEVA)) has been created, encompassing a collection of synthetic biology modular vectors (adapted for their use in actinomycetes). These vectors have been designed for the assembly of transcriptional units and gene circuits in a plug-and-play manner, as well as for genome editing using CRISPR-Cas9-mediated genetic engineering. These vectors have been used for the optimization of the eriodictyol heterologous production levels in S. albidoflavus by enhancing the flavonoid-3'-hydroxylase (F3'H) activity (by means of a chimera design) and by replacing three native biosynthetic gene clusters in the bacterial chromosome with the plant genes matBC (involved in extracellular malonate uptake and its intracellular activation into malonyl-CoA), therefore allowing more malonyl-CoA to be devoted to the heterologous production of plant flavonoids in this bacterial factory. These experiments have allowed an increase in production of 1.8 times in the edited strain (where the three native biosynthetic gene clusters have been deleted) in comparison with the wild-type strain and a 13 times increase in eriodictyol overproduction in comparison with the non-chimaera version of the F3'H enzyme.
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Affiliation(s)
- Patricia Magadán-Corpas
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
| | - Suhui Ye
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
| | - Álvaro Pérez-Valero
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
| | - Patrick L. McAlpine
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
| | - Paula Valdés-Chiara
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
| | - Jesús Torres-Bacete
- Department of Systems Biology, Centro Nacional de Biotecnologia, CSIC, 28049 Madrid, Spain; (J.T.-B.); (J.N.)
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), 28040 Madrid, Spain
| | - Juan Nogales
- Department of Systems Biology, Centro Nacional de Biotecnologia, CSIC, 28049 Madrid, Spain; (J.T.-B.); (J.N.)
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), 28040 Madrid, Spain
| | - Claudio J. Villar
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
| | - Felipe Lombó
- Research Group BIONUC (Biotechnology of Nutraceuticals and Bioactive Compounds), Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 Oviedo, Spain; (P.M.-C.); (S.Y.); (Á.P.-V.); (P.L.M.); (P.V.-C.); (C.J.V.)
- IUOPA (Instituto Universitario de Oncología del Principado de Asturias), 33006 Oviedo, Spain
- ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), 33006 Oviedo, Spain
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Tiroch J, Dunkel A, Sterneder S, Zehentner S, Behrens M, Di Pizio A, Ley JP, Lieder B, Somoza V. Human Gingival Fibroblasts as a Novel Cell Model Describing the Association between Bitter Taste Thresholds and Interleukin-6 Release. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:5314-5325. [PMID: 36943188 PMCID: PMC10080686 DOI: 10.1021/acs.jafc.2c06979] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 02/19/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Human gingival fibroblast cells (HGF-1 cells) present an important cell model to investigate the gingiva's response to inflammatory stimuli such as lipopolysaccharides from Porphyromonas gingivalis (Pg-LPS). Recently, we demonstrated trans-resveratrol to repress the Pg-LPS evoked release of the pro-inflammatory cytokine interleukin-6 (IL-6) via involvement of bitter taste sensing receptor TAS2R50 in HGF-1 cells. Since HGF-1 cells express most of the known 25 TAS2Rs, we hypothesized an association between a compound's bitter taste threshold and its repressing effect on the Pg-LPS evoked IL-6 release by HGF-1 cells. To verify our hypothesis, 11 compounds were selected from the chemical bitter space and subjected to the HGF-1 cell assay, spanning a concentration range between 0.1 μM and 50 mM. In the first set of experiments, the specific role of TAS2R50 was excluded by results from structurally diverse TAS2R agonists and antagonists and by means of a molecular docking approach. In the second set of experiments, the HGF-1 cell response was used to establish a linear association between a compound's effective concentration to repress the Pg-LPS evoked IL-6 release by 25% and its bitter taste threshold concentration published in the literature. The Pearson correlation coefficient revealed for this linear association was R2 = 0.60 (p < 0.01), exceeding respective data for the test compounds from a well-established native cell model, the HGT-1 cells, with R2 = 0.153 (p = 0.263). In conclusion, we provide a predictive model for bitter tasting compounds with a potential to act as anti-inflammatory substances.
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Affiliation(s)
- Johanna Tiroch
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Andreas Dunkel
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | - Sonja Sterneder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Sofie Zehentner
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna 1090, Austria
| | - Maik Behrens
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | - Antonella Di Pizio
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
| | | | - Barbara Lieder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Veronika Somoza
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Leibniz
Institute for Food Systems Biology at the Technical University of
Munich, Freising 85354, Germany
- Chair
for Nutritional Systems Biology, Technical
University Munich, Freising 85354, Germany
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Mistlberger-Reiner A, Sterneder S, Reipert S, Wolske S, Somoza V. Extracellular Vesicles and Particles Modulate Proton Secretion in a Model of Human Parietal Cells. ACS OMEGA 2023; 8:2213-2226. [PMID: 36687051 PMCID: PMC9850724 DOI: 10.1021/acsomega.2c06442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
The secretion of extracellular vesicles and particles (EVPs) is an important mechanism of cellular communication. In this work, we demonstrate a functional role of EVPs in mechanisms regulating gastric acid secretion. HGT-1 cells were used as a model system to assess proton secretion. First, in order to prove EVP secretion by HGT-1 cells, EVPs were isolated by size exclusion chromatography and characterized by nanoparticle tracking analysis, Western blot, and cryo transmission electron microscopy. For examination of the potential role of EVPs in proton secretion, HGT-1 cells were treated with pharmacological EV-inhibitors, resulting in a reduction of histamine-induced proton secretion. To demonstrate the functional role of EVPs in the mechanism of proton secretion, EVP-conditioned supernatant was collected after stimulation of HGT-1 cells with histamine, fractionated, and subjected to an activity screening. The results revealed constituents of the HGT-1-derived secretome with an MW of >100 kDa (including EVPs) to modulate proton secretion, while smaller constituents had no effect. Finally, a dose-dependent modulatory effect on proton secretion of HGT-1 cells was demonstrated by isolated HGT-1-derived EVPs. Hence, this study presents first results on the potential function of EVPs as a previously undiscovered mechanism of regulation of gastric acid secretion by parietal cells.
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Affiliation(s)
- Agnes Mistlberger-Reiner
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Sonja Sterneder
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Siegfried Reipert
- Core
Facility Cell Imaging and Ultrastructure Research, University of Vienna, Vienna 1030, Austria
| | - Sara Wolske
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Veronika Somoza
- Department
of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Freising 85354, Germany
- Nutritional
Systems Biology, Technical University of
Munich, Freising 85354, Germany
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7
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Beltrán LR, Sterneder S, Hasural A, Paetz S, Hans J, Ley JP, Somoza V. Reducing the Bitter Taste of Pharmaceuticals Using Cell-Based Identification of Bitter-Masking Compounds. Pharmaceuticals (Basel) 2022; 15:ph15030317. [PMID: 35337115 PMCID: PMC8953435 DOI: 10.3390/ph15030317] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/20/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
The palatability of a pharmaceutical preparation is a significant obstacle in developing a patient-friendly dosage form. Bitter taste is an important factor for patients in (i) selecting a certain drug from generic products available in the market and (ii) adhering to a therapeutic regimen. The various methods developed for identification of bitter tasting and bitter-taste modulating compounds present a number of limitations, ranging from limited sensitivity to lack of close correlations with sensory data. In this study, we demonstrate a fluorescence-based assay, analyzing the bitter receptor TAS2R-linked intracellular pH (pHi) of human gastric parietal (HGT-1) cells as a suitable tool for the identification of bitter tasting and bitter-taste modulating pharmaceutical compounds and preparations, which resembles bitter taste perception. Among the fluorometric protocols established to analyze pHi changes, one of the most commonly employed assays is based on the use of the pH-sensitive dye SNARF-1 AM. This methodology presents some limitations; over time, the assay shows a relatively low signal amplitude and sensitivity. Here, the SNARF-1 AM methodology was optimized. The identified bicarbonate extrusion mechanisms were partially inhibited, and measurements were carried out in a medium with lower intrinsic fluorescence, with no need for controlling external CO2 levels. We applied the assay for the screening of flavonoids as potential bitter-masking compounds for guaifenesin, a bitter-tasting antitussive drug. Our findings revealed that eriodictyol, hesperitin and phyllodulcin were the most potent suitable candidates for bitter-masking activity, verified in a human sensory trial.
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Affiliation(s)
- Leopoldo Raul Beltrán
- Department of Physiological Chemistry, University of Vienna, 1090 Vienna, Austria; (L.R.B.); (S.S.); (A.H.)
| | - Sonja Sterneder
- Department of Physiological Chemistry, University of Vienna, 1090 Vienna, Austria; (L.R.B.); (S.S.); (A.H.)
| | - Ayse Hasural
- Department of Physiological Chemistry, University of Vienna, 1090 Vienna, Austria; (L.R.B.); (S.S.); (A.H.)
| | - Susanne Paetz
- Symrise AG, Ingredient Research Flavor & Nutrition, 37603 Holzminden, Germany; (S.P.); (J.H.); (J.P.L.)
| | - Joachim Hans
- Symrise AG, Ingredient Research Flavor & Nutrition, 37603 Holzminden, Germany; (S.P.); (J.H.); (J.P.L.)
| | - Jakob Peter Ley
- Symrise AG, Ingredient Research Flavor & Nutrition, 37603 Holzminden, Germany; (S.P.); (J.H.); (J.P.L.)
| | - Veronika Somoza
- Department of Physiological Chemistry, University of Vienna, 1090 Vienna, Austria; (L.R.B.); (S.S.); (A.H.)
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
- Nutritional Systems Biology, Technical University of Munich, 85354 Freising, Germany
- Correspondence: ; Tel.: +43-1-4277-70601
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8
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Tiroch J, Sterneder S, Di Pizio A, Lieder B, Hoelz K, Holik AK, Pignitter M, Behrens M, Somoza M, Ley JP, Somoza V. Bitter Sensing TAS2R50 Mediates the trans-Resveratrol-Induced Anti-inflammatory Effect on Interleukin 6 Release in HGF-1 Cells in Culture. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:13339-13349. [PMID: 33461297 DOI: 10.1021/acs.jafc.0c07058] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Recent data have shown anti-inflammatory effects for trans-resveratrol (RSV) and rosmarinic acid (RA) in various immune-competent cell models through reduction of lipopolysaccharide (LPS)-induced interleukin 6 (IL-6) release. Because both compounds have been reported to taste bitter, we hypothesized an involvement of human bitter taste sensing receptors (TAS2Rs) on IL-6 release in LPS-treated human gingival fibroblasts (HGF-1). First, the bitter taste intensity of RSV and RA was compared in a sensory trial with 10 untrained panelists, of whom 90% rated a 50 ppm of RSV in water solution more bitter than 50 ppm of RA. A mean 19 ± 6% reduction of the RSV-induced bitter taste intensity was achieved by co-administration of 50 ppm of the bitter-masking, TAS2R43 antagonist homoeriodictyol (HED). Mechanistic experiments in a stably CRISPR-Cas9-edited TAS2R43ko gastric cell model revealed involvement of TAS2R43 in the HED-evoked effect on RSV-induced proton secretion, whereas the cellular response to RSV did not depend upon TAS2R43. Next, the IL-6 modulatory effect of 100 μM RSV was studied in LPS-treated immune-competent HGF-1 cells. After 6 h of treatment, RSV reduced the LPS-induced IL-6 gene expression and protein release by -46.2 ± 12.7 and -73.9 ± 2.99%, respectively. This RSV-evoked effect was abolished by co-administration of HED. Because real-time quantitative polymerase chain reaction analyses revealed a regulation of TAS2R50 in RSV with or without HED-treated HGF-1 cells, an siRNA knockdown approach of TAS2R50 was applied to verify TAS2R50 involvement in the RSV-induced reduction of the LPS-evoked IL-6 release in HGT-1 cells.
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Affiliation(s)
- Johanna Tiroch
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Sonja Sterneder
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Antonella Di Pizio
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Barbara Lieder
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Kathrin Hoelz
- Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Ann-Katrin Holik
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Marc Pignitter
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Maik Behrens
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Mark Somoza
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
- Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354 Freising, Germany
| | | | - Veronika Somoza
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
- Chair for Nutritional Systems Biology, Technical University of Munich, 85354 Freising, Germany
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9
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Sterneder S, Stoeger V, Dugulin CA, Liszt KI, Di Pizio A, Korntheuer K, Dunkel A, Eder R, Ley JP, Somoza V. Astringent Gallic Acid in Red Wine Regulates Mechanisms of Gastric Acid Secretion via Activation of Bitter Taste Sensing Receptor TAS2R4. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:10550-10561. [PMID: 34460245 DOI: 10.1021/acs.jafc.1c03061] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Red wine is rich in phenolic compounds, which chiefly determine its characteristic taste. One of its major phenolic acid constituents for which an astringency, yet no clear contribution to bitter taste has been reported, is gallic acid (GA). In previous studies, we have demonstrated bitter-tasting constituents to regulate cellular proton secretion (PS) as a key mechanism of gastric acid secretion via activation of bitter taste sensing receptors (TAS2Rs). Here, we hypothesized a contributing role of GA to the red wine-stimulated effect on PS in human gastric tumor cells (HGT-1 cells). Sensory analyses revealed that 10 μM GA as the lowest concentration tested more bitter than tap water, with increasing bitter ratings up to 1000 μM. In HGT-1 cells, the concentration of 10 μM GA evoked the most pronounced effect on PS secretion, either when added to cells as in-water solution or when spiked to a red wine matrix. GA-spiking of Zweigelt and Blaufränkisch red wine samples up to a concentration of 10 μM resulted in an equally stimulated PS, whereas the non-GA-spiked wine samples demonstrated contrary effects on PS, indicating a functional role of GA on PS. Involvement of TAS2R4 in the GA-induced PS was verified by means of an HGT-1 homozygote CRISPR-Cas9 TAS2R4 knockout approach. Moreover, gene expression analyses revealed GA to increase TAS2R4. These results demonstrate a functional role of TAS2R4 in GA-evoked PS as a key mechanism of gastric acid secretion aiding digestion. Moreover, our data provide mechanistic insights, which will help to produce stomach-friendly red wines.
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Affiliation(s)
- Sonja Sterneder
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstrasse 14 (UZA II), Vienna 1090, Austria
| | - Verena Stoeger
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstrasse 14 (UZA II), Vienna 1090, Austria
| | - Celina Angela Dugulin
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstrasse 14 (UZA II), Vienna 1090, Austria
| | - Kathrin Ingrid Liszt
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstrasse 14 (UZA II), Vienna 1090, Austria
| | - Antonella Di Pizio
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Karin Korntheuer
- Federal College and Research Institute for Viticulture and Pomology, Klosterneuburg 3400, Austria
| | - Andreas Dunkel
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Reinhard Eder
- Federal College and Research Institute for Viticulture and Pomology, Klosterneuburg 3400, Austria
| | - Jakob Peter Ley
- Research & Technology Flavors Division, Symrise AG, 37603 Holzminden, Germany
| | - Veronika Somoza
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstrasse 14 (UZA II), Vienna 1090, Austria
- Leibniz-Institute of Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
- Nutritional Systems Biology, Technical University of Munich, 85354 Freising, Germany
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10
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Holik AK, Schweiger K, Stoeger V, Lieder B, Reiner A, Zopun M, Hoi JK, Kretschy N, Somoza MM, Kriwanek S, Pignitter M, Somoza V. Gastric Serotonin Biosynthesis and Its Functional Role in L-Arginine-Induced Gastric Proton Secretion. Int J Mol Sci 2021; 22:5881. [PMID: 34070942 PMCID: PMC8199169 DOI: 10.3390/ijms22115881] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/22/2021] [Accepted: 05/26/2021] [Indexed: 11/23/2022] Open
Abstract
Among mammals, serotonin is predominantly found in the gastrointestinal tract, where it has been shown to participate in pathway-regulating satiation. For the stomach, vascular serotonin release induced by gastric distension is thought to chiefly contribute to satiation after food intake. However, little information is available on the capability of gastric cells to synthesize, release and respond to serotonin by functional changes of mechanisms regulating gastric acid secretion. We investigated whether human gastric cells are capable of serotonin synthesis and release. First, HGT-1 cells, derived from a human adenocarcinoma of the stomach, and human stomach specimens were immunostained positive for serotonin. In HGT-1 cells, incubation with the tryptophan hydroxylase inhibitor p-chlorophenylalanine reduced the mean serotonin-induced fluorescence signal intensity by 27%. Serotonin release of 147 ± 18%, compared to control HGT-1 cells (set to 100%) was demonstrated after treatment with 30 mM of the satiating amino acid L-Arg. Granisetron, a 5-HT3 receptor antagonist, reduced this L-Arg-induced serotonin release, as well as L-Arg-induced proton secretion. Similarly to the in vitro experiment, human antrum samples released serotonin upon incubation with 10 mM L-Arg. Overall, our data suggest that human parietal cells in culture, as well as from the gastric antrum, synthesize serotonin and release it after treatment with L-Arg via an HTR3-related mechanism. Moreover, we suggest not only gastric distension but also gastric acid secretion to result in peripheral serotonin release.
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Affiliation(s)
- Ann-Katrin Holik
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (A.-K.H.); (K.S.); (B.L.); (M.Z.); (M.P.)
| | - Kerstin Schweiger
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (A.-K.H.); (K.S.); (B.L.); (M.Z.); (M.P.)
| | - Verena Stoeger
- Christian Doppler Laboratory for Bioactive Aroma Compounds, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (V.S.); (J.K.H.)
| | - Barbara Lieder
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (A.-K.H.); (K.S.); (B.L.); (M.Z.); (M.P.)
- Christian Doppler Laboratory for Bioactive Aroma Compounds, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (V.S.); (J.K.H.)
| | - Angelika Reiner
- Pathologisch-Bakteriologisches Institut, Sozialmedizinisches Zentrum Ost- Donauspital, Langobardenstraße 122, 1220 Vienna, Austria;
| | - Muhammet Zopun
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (A.-K.H.); (K.S.); (B.L.); (M.Z.); (M.P.)
| | - Julia K. Hoi
- Christian Doppler Laboratory for Bioactive Aroma Compounds, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (V.S.); (J.K.H.)
| | - Nicole Kretschy
- Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (N.K.); (M.M.S.)
| | - Mark M. Somoza
- Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (N.K.); (M.M.S.)
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany
- Leibniz Institute for Food Systems Biology, Technical University of Munich, Lise-Meitner-Str. 34, 85345 Freising, Germany
| | - Stephan Kriwanek
- Chirurgische Abteilung, Sozialmedizinisches Zentrum Ost- Donauspital, Langobardenstraße 122, 1220 Vienna, Austria;
| | - Marc Pignitter
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (A.-K.H.); (K.S.); (B.L.); (M.Z.); (M.P.)
| | - Veronika Somoza
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (A.-K.H.); (K.S.); (B.L.); (M.Z.); (M.P.)
- Christian Doppler Laboratory for Bioactive Aroma Compounds, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; (V.S.); (J.K.H.)
- Leibniz Institute for Food Systems Biology, Technical University of Munich, Lise-Meitner-Str. 34, 85345 Freising, Germany
- Nutritional Systems Biology, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85345 Freising, Germany
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11
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Fotsing JR, Darmohusodo V, Patron AP, Ching BW, Brady T, Arellano M, Chen Q, Davis TJ, Liu H, Servant G, Zhang L, Williams M, Saganich M, Ditschun T, Tachdjian C, Karanewsky DS. Discovery and Development of S6821 and S7958 as Potent TAS2R8 Antagonists. J Med Chem 2020; 63:4957-4977. [PMID: 32330040 DOI: 10.1021/acs.jmedchem.0c00388] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In humans, bitter taste is mediated by 25 TAS2Rs. Many compounds, including certain active pharmaceutical ingredients, excipients, and nutraceuticals, impart their bitter taste (or in part) through TAS2R8 activation. However, effective TAS2R8 blockers that can either suppress or reduce the bitterness of these compounds have not been described. We are hereby reporting a series of novel 3-(pyrazol-4-yl) imidazolidine-2,4-diones as potent and selective TAS2R8 antagonists. In human sensory tests, S6821 and S7958, two of the most potent analogues from the series, demonstrated efficacy in blocking TAS2R8-mediated bitterness and were selected for development. Following data evaluation by expert panels of a number of national and multinational regulatory bodies, including the US, the EU, and Japan, S6821 and S7958 were approved as safe under conditions of intended use as bitter taste blockers.
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Affiliation(s)
- Joseph R Fotsing
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Vincent Darmohusodo
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Andrew P Patron
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Brett W Ching
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Thomas Brady
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Melissa Arellano
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Qing Chen
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Timothy J Davis
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Hanghui Liu
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Guy Servant
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Lan Zhang
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Mark Williams
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Michael Saganich
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Tanya Ditschun
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Catherine Tachdjian
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Donald S Karanewsky
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
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12
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Stoeger V, Holik AK, Hölz K, Dingjan T, Hans J, Ley JP, Krammer GE, Niv MY, Somoza MM, Somoza V. Bitter-Tasting Amino Acids l-Arginine and l-Isoleucine Differentially Regulate Proton Secretion via T2R1 Signaling in Human Parietal Cells in Culture. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3434-3444. [PMID: 31891507 DOI: 10.1021/acs.jafc.9b06285] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This study aimed at identifying whether the bitter-tasting amino acids l-arginine (l-ARG) and l-isoleucine (l-ILE) differentially regulate mechanisms of gastric acid secretion in human parietal cells (HGT-1 cells) via activation of bitter taste sensing receptors (T2Rs). In a first set of experiments, involvement of T2Rs in l-ARG and l-ILE-modulated proton secretion was demonstrated by co-treatment of HGT-1 cells with T2R antagonists. Subsequent whole genome screenings by means of cDNA arrays revealed T2R1 as a prominent target for both amino acids. Next, the functional role of T2R1 was verified by means of a T2R1 CRISPR-Cas9 knock-out approach. Here, the effect of l-ARG on proton secretion decreased by 65.7 ± 21.9% and the effect of l-ILE increased by 93.2 ± 24.1% in HGT-1 T2R1 ko versus HGT-1 wt cells (p < 0.05). Overall, our results indicate differential effects of l-ARG and l-ILE on proton secretion in HGT-1 cells and our molecular docking studies predict distinct binding for these amino acids in the binding site of T2R1. Further studies will elucidate whether the mechanism of differential effects involves structure-specific ligand-biased signaling of T2R1 or additional cellular targets.
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Affiliation(s)
| | | | | | - Tamir Dingjan
- Institute of Biochemistry, Food Science and Nutrition, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
| | - Joachim Hans
- Symrise AG Global Innovation Cosmetic Ingredient Research, Research & Technology Flavors Division, P.O. Box 1253, Holzminden 37603, Germany
| | - Jakob P Ley
- Symrise AG Global Innovation Cosmetic Ingredient Research, Research & Technology Flavors Division, P.O. Box 1253, Holzminden 37603, Germany
| | - Gerhard E Krammer
- Symrise AG Global Innovation Cosmetic Ingredient Research, Research & Technology Flavors Division, P.O. Box 1253, Holzminden 37603, Germany
| | - Masha Y Niv
- Institute of Biochemistry, Food Science and Nutrition, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
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13
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Widmayer P, Partsch V, Pospiech J, Kusumakshi S, Boehm U, Breer H. Distinct Cell Types With the Bitter Receptor Tas2r126 in Different Compartments of the Stomach. Front Physiol 2020; 11:32. [PMID: 32116750 PMCID: PMC7019106 DOI: 10.3389/fphys.2020.00032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 01/15/2020] [Indexed: 12/16/2022] Open
Abstract
Cells expressing bitter taste receptors (T2Rs or Tas2rs) in extraoral tissues are considered to be chemosensory cells mediating protective responses to potentially harmful or even antiinflammatory or antimicrobial compounds. In a previous study the activity of the Tas2R143/Tas2R135/Tas2r126 cluster promoter in the stomach was monitored using a Cre-reporter mouse line. Reporter gene expression and Tas2r126 mRNA were found in brush cells located at the distal wall of the gastric groove. In this study, we explored whether brush cells and epithelial cells of the stomach in fact contain the Tas2r126 receptor protein. Using immunohistochemistry, we demonstrate the presence of Tas2r126 immunoreactivity in different cell populations in the glandular stomach, in a subset of brush cells at the gastric groove and in unique glandular units as well as in certain enteroendocrine cells. In brush cells at the gastric groove, a strong immunofluorescence signal for the Tas2r126 receptor was observed at the most apical region of the cells, i.e., the microvillar tuft. In addition, we found a high density of Tas2r126-positive brush cells in the unique glandular units. These invaginations are located distally to the groove, open directly into the furrow and are enwrapped by smoothelin-immunoreactive muscles. In the corpus, Tas2r126 immunoreactivity was found in histamine-producing ECL cells and in ghrelin-producing X/A-like cells, the main enteroendcrine cells of this compartment. In the antrum, Tas2r126 labeling was observed in serotonin-storing EC cells and ghrelin cells, both representing only minor populations of enteroendocrine cells in this compartment. In conclusion, our data provide evidence for the presence of the Tas2r126 receptor protein in distinct cell types in the epithelium lining the mouse stomach which render the stomach responsive to agonists for bitter receptors.
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Affiliation(s)
- Patricia Widmayer
- Institute of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Vanessa Partsch
- Institute of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Jonas Pospiech
- Institute of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Soumya Kusumakshi
- Experimental Pharmacology, Center for Molecular Signaling, School of Medicine, Saarland University, Homburg, Germany
| | - Ulrich Boehm
- Experimental Pharmacology, Center for Molecular Signaling, School of Medicine, Saarland University, Homburg, Germany
| | - Heinz Breer
- Institute of Physiology, University of Hohenheim, Stuttgart, Germany
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14
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Stoeger V, Liszt KI, Lieder B, Wendelin M, Zopun M, Hans J, Ley JP, Krammer GE, Somoza V. Identification of Bitter-Taste Intensity and Molecular Weight as Amino Acid Determinants for the Stimulating Mechanisms of Gastric Acid Secretion in Human Parietal Cells in Culture. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:6762-6771. [PMID: 29879844 DOI: 10.1021/acs.jafc.8b01802] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Secretion of gastric acid, aimed at preventing bacterial growth and aiding the digestion of foods in the stomach, is chiefly stimulated by dietary intake of protein and amino acids (AAs). However, AAs' key structural determinants responsible for their effects on mechanisms regulating gastric acid secretion (GAS) have not been identified yet. In this study, AAs have been tested in the parietal cell model HGT-1 on GAS and on mRNA expression of genes regulating GAS. AAs' taste intensities from 0 (not bitter at all) to 10 (very bitter) were assessed in a sensory study, in which ARG (l: 6.42 ± 0.41; d: 4.62 ± 0.59) and ILE (l: 4.21 ± 0.43; d: 2.28 ± 0.33) were identified as bitter-tasting candidates in both isomeric forms. Pearson correlation showed that GAS in HGT-1 cells is directly associated with the bitter taste quality ( r: -0.654) in combination with the molecular weight of l-AA ( r: -0.685).
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Affiliation(s)
| | | | | | - Martin Wendelin
- Symrise Austria , Sensory and Consumer Insights , Heiligenstädterstraße 31/3 , 1190 Wien , Austria
| | | | - Joachim Hans
- Symrise AG , Research & Technology Flavors Division , P.O. Box 1253, 37603 Holzminden , Germany
| | - Jakob P Ley
- Symrise AG , Research & Technology Flavors Division , P.O. Box 1253, 37603 Holzminden , Germany
| | - Gerhard E Krammer
- Symrise AG , Research & Technology Flavors Division , P.O. Box 1253, 37603 Holzminden , Germany
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15
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Zopun M, Liszt KI, Stoeger V, Behrens M, Redel U, Ley JP, Hans J, Somoza V. Human Sweet Receptor T1R3 is Functional in Human Gastric Parietal Tumor Cells (HGT-1) and Modulates Cyclamate and Acesulfame K-Induced Mechanisms of Gastric Acid Secretion. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:4842-4852. [PMID: 29665689 DOI: 10.1021/acs.jafc.8b00658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The noncaloric sweeteners (NCSs) cyclamate (Cycl) and acesulfame K (AceK) are widely added to foods and beverages. Little is known about their impact on gastric acid secretion (GAS), which is stimulated by dietary protein and bitter-tasting compounds. Since Cycl and AceK have a bitter off taste in addition to their sweet taste, we hypothesized they modulate mechanisms of GAS in human gastric parietal cells (HGT-1). HGT-1 cells were exposed to sweet tastants (50 mM of glucose, d-threonine, Cycl, or AceK) and analyzed for their intracellular pH index (IPX), as an indicator of proton secretion by means of a pH-sensitive dye, and for mRNA levels of GAS-associated genes by RT-qPCR. Since the NCSs act via the sweet taste-sensing receptor T1R2/T1R3, mRNA expression of the corresponding genes was analyzed in addition to immunocytochemical localization of the T1R2 and T1R3 receptor proteins. Exposure of HGT-1 cells to AceK or d-threonine increased the IPX to 0.60 ± 0.05 and 0.80 ± 0.04 ( P ≤ 0.05), respectively, thereby indicating a reduced secretion of protons, whereas Cycl demonstrated the opposite effect with IPX values of -0.69 ± 0.08 ( P ≤ 0.05) compared to controls (IPX = 0). Cotreatment with the T1R3-inhibitor lactisole as well as a TAS1R3 siRNA knock-down approach reduced the impact of Cycl, AceK, and d-thr on proton release ( P ≤ 0.05), whereas cotreatment with 10 mM glucose enhanced the NCS-induced effect ( P ≤ 0.05). Overall, we demonstrated Cycl and AceK as modulators of proton secretion in HGT-1 cells and identified T1R3 as a key element in this response.
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Affiliation(s)
- Muhammet Zopun
- Faculty of Chemistry, Department of Physiological Chemistry , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
| | - Kathrin I Liszt
- Faculty of Chemistry, Christian Doppler Laboratory for Bioactive Aroma Compounds , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
| | - Verena Stoeger
- Faculty of Chemistry, Christian Doppler Laboratory for Bioactive Aroma Compounds , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
| | - Maik Behrens
- Department of Molecular Genetics , German Institute of Human Nutrition Potsdam-Rehbruecke , Arthur-Scheunert-Allee , 114-116 Nuthetal , Germany
| | - Ulrike Redel
- Department of Molecular Genetics , German Institute of Human Nutrition Potsdam-Rehbruecke , Arthur-Scheunert-Allee , 114-116 Nuthetal , Germany
| | - Jakob P Ley
- Symrise AG , Mühlenfeldstraße 1 , 37603 Holzminden , Germany
| | - Joachim Hans
- Symrise AG , Mühlenfeldstraße 1 , 37603 Holzminden , Germany
| | - Veronika Somoza
- Faculty of Chemistry, Department of Physiological Chemistry , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
- Faculty of Chemistry, Christian Doppler Laboratory for Bioactive Aroma Compounds , University of Vienna , Althanstraße 14 , Vienna 1090 , Austria
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