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Calatayud M, Börner RA, Ghyselinck J, Verstrepen L, Medts JD, den Abbeele PV, Boulangé CL, Priour S, Marzorati M, Damak S. Water Kefir and Derived Pasteurized Beverages Modulate Gut Microbiota, Intestinal Permeability and Cytokine Production In Vitro. Nutrients 2021; 13:nu13113897. [PMID: 34836151 PMCID: PMC8625349 DOI: 10.3390/nu13113897] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 01/08/2023] Open
Abstract
Fermentation is an ancient food preservation process, and fermented products have been traditionally consumed in different cultures worldwide over the years. The interplay between human gut microbiota, diet and host health is widely recognized. Diet is one of the main factors modulating gut microbiota potentially with beneficial effects on human health. Fermented dairy products have received much attention, but other sources of probiotic delivery through food received far less attention. In this research, a combination of in vitro tools mimicking colonic fermentation and the intestinal epithelium have been applied to study the effect of different pasteurized and non-pasteurized water kefir products on gut microbiota, epithelial barrier function and immunomodulation. Water kefir increased beneficial short-chain fatty acid production at the microbial level, reduced detrimental proteolytic fermentation compounds and increased Bifidobacterium genus abundance. The observed benefits are enhanced by pasteurization. Pasteurized products also had a significant effect at the host level, improving inflammation-induced intestinal epithelial barrier disruption and increasing IL-10 and IL-1β compared to the control condition. Our data support the potential health benefits of water kefir and demonstrate that pasteurization, performed to prolong shelf life and stability of the product, also enhanced these benefits.
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Affiliation(s)
- Marta Calatayud
- ProDigest, Technologiepark 82, 9052 Zwijnaarde, Belgium; (M.C.); (J.G.); (L.V.); (J.D.M.); (P.V.d.A.)
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Rosa Aragao Börner
- Nestlé Institute of Health Sciences, and Nestlé Institute of Material Sciences, Nestlé Research, Société des Produits Nestlé S.A., Vers-chez-les-Blanc, 1000 Lausanne, Switzerland; (C.L.B.); (S.P.); (S.D.)
- Correspondence: (R.A.B.); (M.M.)
| | - Jonas Ghyselinck
- ProDigest, Technologiepark 82, 9052 Zwijnaarde, Belgium; (M.C.); (J.G.); (L.V.); (J.D.M.); (P.V.d.A.)
| | - Lynn Verstrepen
- ProDigest, Technologiepark 82, 9052 Zwijnaarde, Belgium; (M.C.); (J.G.); (L.V.); (J.D.M.); (P.V.d.A.)
| | - Jelle De Medts
- ProDigest, Technologiepark 82, 9052 Zwijnaarde, Belgium; (M.C.); (J.G.); (L.V.); (J.D.M.); (P.V.d.A.)
| | - Pieter Van den Abbeele
- ProDigest, Technologiepark 82, 9052 Zwijnaarde, Belgium; (M.C.); (J.G.); (L.V.); (J.D.M.); (P.V.d.A.)
| | - Claire L. Boulangé
- Nestlé Institute of Health Sciences, and Nestlé Institute of Material Sciences, Nestlé Research, Société des Produits Nestlé S.A., Vers-chez-les-Blanc, 1000 Lausanne, Switzerland; (C.L.B.); (S.P.); (S.D.)
| | - Sarah Priour
- Nestlé Institute of Health Sciences, and Nestlé Institute of Material Sciences, Nestlé Research, Société des Produits Nestlé S.A., Vers-chez-les-Blanc, 1000 Lausanne, Switzerland; (C.L.B.); (S.P.); (S.D.)
| | - Massimo Marzorati
- ProDigest, Technologiepark 82, 9052 Zwijnaarde, Belgium; (M.C.); (J.G.); (L.V.); (J.D.M.); (P.V.d.A.)
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
- Correspondence: (R.A.B.); (M.M.)
| | - Sami Damak
- Nestlé Institute of Health Sciences, and Nestlé Institute of Material Sciences, Nestlé Research, Société des Produits Nestlé S.A., Vers-chez-les-Blanc, 1000 Lausanne, Switzerland; (C.L.B.); (S.P.); (S.D.)
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Foata F, Sprenger N, Rochat F, Damak S. Activation of the G-protein coupled receptor GPR35 by human milk oligosaccharides through different pathways. Sci Rep 2020; 10:16117. [PMID: 32999316 PMCID: PMC7528069 DOI: 10.1038/s41598-020-73008-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022] Open
Abstract
Numerous benefits of breastfeeding over infant formula are fully established. The superiority of human milk over bovine milk-based formula is partly due to human milk oligosaccharides (HMOs), a family of over 100 molecules present specifically and substantially in human milk that resemble mucosal glycans. To uncover novel physiological functions and pathways of HMOs, we screened a panel of 165 G-protein coupled receptors (GPCRs) using a blend of 6 HMOs (3'-O-sialyllactose (3'SL), 6'-O-sialyllactose (6'SL), lacto-N-tetraose (LNT), lacto-N-neo-tetraose (LNnT), 2-O-fucosyllactose (2'FL), and difucosyllactose (diFL)), and followed up positive hits with standard receptor assays. The HMO blend specifically activated GPR35. LNT and 6'SL individually activated GPR35, and they showed synergy when used together. In addition, in vitro fermentation of infant stool samples showed that 2'FL upregulates the production of the GPR35 agonist kynurenic acid (KYNA) by the microbiota. LNT + 6'SL and KYNA showed additive activation of GPR35. Activation by 6'SL and LNT of GPR35, a receptor mediating attenuation of pain and colitis, is to our knowledge the first demonstration of GPCR activation by any HMO. In addition, we demonstrated a remarkable cooperation between nutrition and microbiota towards activation of a host receptor highlighting the close interplay between environment and host-microbe interactions.
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Affiliation(s)
- Francis Foata
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland
| | - Norbert Sprenger
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland
| | - Florence Rochat
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland
| | - Sami Damak
- Société des Produits Nestlé S.A., Nestlé Research, Route du Jorat, Vers-chez-les-Blanc, 1000, Lausanne 26, Switzerland.
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Dogra SK, Doré J, Damak S. Gut Microbiota Resilience: Definition, Link to Health and Strategies for Intervention. Front Microbiol 2020; 11:572921. [PMID: 33042082 PMCID: PMC7522446 DOI: 10.3389/fmicb.2020.572921] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/24/2020] [Indexed: 12/15/2022] Open
Abstract
The gut microbiota is a new frontier in health and disease. Not only many diseases are associated with perturbed microbiota, but an increasing number of studies point to a cause-effect relationship. Defining a healthy microbiota is not possible at the current state of our knowledge mostly because of high interindividual variability. A resilient microbiota could be used as surrogate for healthy microbiota. In addition, the gut microbiota is an “organ” with frontline exposure to environmental changes and insults. During the lifetime of an individual, it is exposed to challenges such as unhealthy diet, medications and infections. Impaired ability to bounce back to the pre-challenge baseline may lead to dysbiosis. It is therefore legitimate to postulate that maintaining a resilient microbiota may be important for health. Here we review the concept of resilience, what is known about the characteristics of a resilient microbiota, and how to assess microbiota resilience experimentally using a model of high fat diet challenge in humans. Interventions to maintain microbiota resilience can be guided by the knowledge of what microbial species or functions are perturbed by challenges, and designed to replace diminished species with probiotics, when available, or boost them with prebiotics. Fibers with multiple structures and composition can also be used to increase microbiota diversity, a characteristic of the microbiota that may be associated with resilience. We finally discuss some open questions and knowledge gaps.
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Affiliation(s)
| | - Joel Doré
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement, MetaGenoPolis, AgroParisTech, Microbiologie de l'Alimentation au Service de la Santé, Jouy-en-Josas, France
| | - Sami Damak
- Nestlé Research, Société des Produits Nestlé SA, Lausanne, Switzerland
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Schilperoort M, van Dam AD, Hoeke G, Shabalina IG, Okolo A, Hanyaloglu AC, Dib LH, Mol IM, Caengprasath N, Chan YW, Damak S, Miller AR, Coskun T, Shimpukade B, Ulven T, Kooijman S, Rensen PC, Christian M. The GPR120 agonist TUG-891 promotes metabolic health by stimulating mitochondrial respiration in brown fat. EMBO Mol Med 2019; 10:emmm.201708047. [PMID: 29343498 PMCID: PMC5840546 DOI: 10.15252/emmm.201708047] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Brown adipose tissue (BAT) activation stimulates energy expenditure in human adults, which makes it an attractive target to combat obesity and related disorders. Recent studies demonstrated a role for G protein-coupled receptor 120 (GPR120) in BAT thermogenesis. Here, we investigated the therapeutic potential of GPR120 agonism and addressed GPR120-mediated signaling in BAT We found that activation of GPR120 by the selective agonist TUG-891 acutely increases fat oxidation and reduces body weight and fat mass in C57Bl/6J mice. These effects coincided with decreased brown adipocyte lipid content and increased nutrient uptake by BAT, confirming increased BAT activity. Consistent with these observations, GPR120 deficiency reduced expression of genes involved in nutrient handling in BAT Stimulation of brown adipocytes in vitro with TUG-891 acutely induced O2 consumption, through GPR120-dependent and GPR120-independent mechanisms. TUG-891 not only stimulated GPR120 signaling resulting in intracellular calcium release, mitochondrial depolarization, and mitochondrial fission, but also activated UCP1. Collectively, these data suggest that activation of brown adipocytes with the GPR120 agonist TUG-891 is a promising strategy to increase lipid combustion and reduce obesity.
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Affiliation(s)
- Maaike Schilperoort
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK .,Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden, The Netherlands
| | - Andrea D van Dam
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden, The Netherlands
| | - Geerte Hoeke
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden, The Netherlands
| | - Irina G Shabalina
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
| | - Anthony Okolo
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, London, UK
| | - Aylin C Hanyaloglu
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, London, UK
| | - Lea H Dib
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Isabel M Mol
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden, The Netherlands
| | - Natarin Caengprasath
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, London, UK
| | - Yi-Wah Chan
- Lymphocyte Development Group, MRC London Institute of Medical Sciences, Hammersmith Campus Imperial College London, London, UK
| | - Sami Damak
- Nestlé Research Center, Lausanne, Switzerland
| | - Anne Reifel Miller
- Lilly Research Laboratories, Diabetes/Endocrine Department, Lilly Corporate Center, Indianapolis, IN, USA
| | - Tamer Coskun
- Lilly Research Laboratories, Diabetes/Endocrine Department, Lilly Corporate Center, Indianapolis, IN, USA
| | - Bharat Shimpukade
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Trond Ulven
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Sander Kooijman
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden, The Netherlands
| | - Patrick Cn Rensen
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands.,Einthoven Laboratory for Experimental Vascular Medicine, Leiden, The Netherlands
| | - Mark Christian
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
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Affiliation(s)
- Sami Damak
- Nestlé Research Center, Lausanne, Switzerland
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Godinot N, Yasumatsu K, Barcos M, Pineau N, Ledda M, Viton F, Ninomiya Y, le Coutre J, Damak S. Activation of tongue-expressed GPR40 and GPR120 by non caloric agonists is not sufficient to drive preference in mice. Neuroscience 2013; 250:20-30. [DOI: 10.1016/j.neuroscience.2013.06.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/18/2013] [Accepted: 06/20/2013] [Indexed: 10/26/2022]
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Soussou N, Gzara A, Damak S, Hmida S. Estimation du coût de la non qualité appliqué à la production des CGR au niveau du Centre national de transfusion sanguine de Tunis. Transfus Clin Biol 2013. [DOI: 10.1016/j.tracli.2013.03.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cettour-Rose P, Bezençon C, Darimont C, le Coutre J, Damak S. Quinine controls body weight gain without affecting food intake in male C57BL6 mice. BMC Physiol 2013; 13:5. [PMID: 23394313 PMCID: PMC3575391 DOI: 10.1186/1472-6793-13-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 02/04/2013] [Indexed: 12/04/2022]
Abstract
Background Quinine is a natural molecule commonly used as a flavouring agent in tonic water. Diet supplementation with quinine leads to decreased body weight and food intake in rats. Quinine is an in vitro inhibitor of Trpm5, a cation channel expressed in taste bud cells, the gastrointestinal tract and pancreas. The objective of this work is to determine the effect of diet supplementation with quinine on body weight and body composition in male mice, to investigate its mechanism of action, and whether the effect is mediated through Trpm5. Results Compared with mice consuming AIN, a regular balanced diet, mice consuming AIN diet supplemented with 0.1% quinine gained less weight (2.89 ± 0.30 g vs 5.39 ± 0.50 g) and less fat mass (2.22 ± 0.26 g vs 4.33 ± 0.43 g) after 13 weeks of diet, and had lower blood glucose and plasma triglycerides. There was no difference in food intake between the mice consuming quinine supplemented diet and those consuming control diet. Trpm5 knockout mice gained less fat mass than wild-type mice. There was a trend for a diet-genotype interaction for body weight and body weight gain, with the effect of quinine less pronounced in the Trpm5 KO than in the WT background. Faecal weight, energy and lipid contents were higher in quinine fed mice compared to regular AIN fed mice and in Trpm5 KO mice compared to wild type mice. Conclusion Quinine contributes to weight control in male C57BL6 mice without affecting food intake. A partial contribution of Trpm5 to quinine dependent body weight control is suggested.
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Damak S, Mosinger B, Margolskee RF. Transsynaptic transport of wheat germ agglutinin expressed in a subset of type II taste cells of transgenic mice. BMC Neurosci 2008; 9:96. [PMID: 18831764 PMCID: PMC2571104 DOI: 10.1186/1471-2202-9-96] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 10/02/2008] [Indexed: 11/15/2022] Open
Abstract
Background Anatomical tracing of neural circuits originating from specific subsets of taste receptor cells may shed light on interactions between taste cells within the taste bud and taste cell-to nerve interactions. It is unclear for example, if activation of type II cells leads to direct activation of the gustatory nerves, or whether the information is relayed through type III cells. To determine how WGA produced in T1r3-expressing taste cells is transported into gustatory neurons, transgenic mice expressing WGA-IRES-GFP driven by the T1r3 promoter were generated. Results Immunohistochemistry showed co-expression of WGA, GFP and endogenous T1r3 in the taste bud cells of transgenic mice: the only taste cells immunoreactive for WGA were the T1r3-expressing cells. The WGA antibody also stained intragemmal nerves. WGA, but not GFP immunoreactivity was found in the geniculate and petrosal ganglia of transgenic mice, indicating that WGA was transported across synapses. WGA immunoreactivity was also found in the trigeminal ganglion, suggesting that T1r3-expressing cells make synapses with trigeminal neurons. In the medulla, WGA was detected in the nucleus of the solitary tract but also in the nucleus ambiguus, the vestibular nucleus, the trigeminal nucleus and in the gigantocellular reticular nucleus. WGA was not detected in the parabrachial nucleus, or the gustatory cortex. Conclusion These results show the usefulness of genetically encoded WGA as a tracer for the first and second order neurons that innervate a subset of taste cells, but not for higher order neurons, and demonstrate that the main route of output from type II taste cells is the gustatory neuron, not the type III cells.
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Affiliation(s)
- Sami Damak
- Department of Physiology and Biophysics, Mount Sinai School of Medicine, 1425 Madison Avenue, Box 1677, New York, New York, 10029, USA.
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Rong M, He W, Yasumatsu K, Kokrashvili Z, Perez CA, Mosinger B, Ninomiya Y, Margolskee RF, Damak S. Signal transduction of umami taste: insights from knockout mice. Chem Senses 2008; 30 Suppl 1:i33-4. [PMID: 15738181 DOI: 10.1093/chemse/bjh099] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Minqing Rong
- Department of Physiology and Biophysics, Howard Hughes Medical Institute, the Mount Sinai School of Medicine, 1 Gustave L. Levy Place, New York, NY 10029, USA
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Bezençon C, Fürholz A, Raymond F, Mansourian R, Métairon S, Le Coutre J, Damak S. Murine intestinal cells expressing Trpm5 are mostly brush cells and express markers of neuronal and inflammatory cells. J Comp Neurol 2008; 509:514-25. [DOI: 10.1002/cne.21768] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Blednov YA, Walker D, Martinez M, Levine M, Damak S, Margolskee RF. Perception of sweet taste is important for voluntary alcohol consumption in mice. Genes Brain Behav 2008; 7:1-13. [PMID: 17376151 PMCID: PMC4408608 DOI: 10.1111/j.1601-183x.2007.00309.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To directly evaluate the association between taste perception and alcohol intake, we used three different mutant mice, each lacking a gene expressed in taste buds and critical to taste transduction: alpha-gustducin (Gnat3), Tas1r3 or Trpm5. Null mutant mice lacking any of these three genes showed lower preference score for alcohol and consumed less alcohol in a two-bottle choice test, as compared with wild-type littermates. These null mice also showed lower preference score for saccharin solutions than did wild-type littermates. In contrast, avoidance of quinine solutions was less in Gnat3 or Trpm5 knockout mice than in wild-type mice, whereas Tas1r3 null mice were not different from wild type in their response to quinine solutions. There were no differences in null vs. wild-type mice in their consumption of sodium chloride solutions. To determine the cause for reduction of ethanol intake, we studied other ethanol-induced behaviors known to be related to alcohol consumption. There were no differences between null and wild-type mice in ethanol-induced loss of righting reflex, severity of acute ethanol withdrawal or conditioned place preference for ethanol. Weaker conditioned taste aversion (CTA) to alcohol in null mice may have been caused by weaker rewarding value of the conditioned stimulus (saccharin). When saccharin was replaced by sodium chloride, no differences in CTA to alcohol between knockout and wild-type mice were seen. Thus, deletion of any one of three different genes involved in detection of sweet taste leads to a substantial reduction of alcohol intake without any changes in pharmacological actions of ethanol.
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Affiliation(s)
- Y A Blednov
- Waggoner Center for Alcohol and Addiction Research, 1 University Station A4800, Austin, TX 78712-0159, USA.
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Abstract
Tight junctions operate as semipermeable barriers in epithelial tissue, separating the apical from the basolateral sides of the cells. Membrane proteins of the claudin family represent the major tight junction constituents, and some reinforce permeability barriers, whereas others create pores based on solute size and ion selectivity. To outline paracellular permeability pathways in gustatory tissue, all claudins expressed in mouse taste buds and in human fungiform papillae have been characterized. Twelve claudins are expressed in murine taste-papillae-enriched tissue, and five of those are expressed in human fungiform papillae. A subset of the claudins expressed in mouse papillae is uniquely found in taste buds. By immunohistochemistry, claudin 4 has been found in mouse taste epithelium, with high abundance around the taste pore. Claudin 6 is explicitly detected inside the pore, claudin 7 was found at the basolateral side of taste cells, and claudin 8 was found around the pore. With the ion permeability features of the different claudins, a highly specific permeability pattern for paracellular diffusion is apparent, which indicates a peripheral mechanism for taste coding.
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Affiliation(s)
- Stéphanie Michlig
- Nestlé Research Center, Vers-chez-les-Blanc, Lausanne 1000, Switzerland
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Casillas JM, Gremeaux V, Damak S, Feki A, Pérennou D. Exercise training for patients with cardiovascular disease. ACTA ACUST UNITED AC 2007; 50:403-18, 386-402. [PMID: 17445931 DOI: 10.1016/j.annrmp.2007.03.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Accepted: 03/09/2007] [Indexed: 01/19/2023]
Abstract
This review surveys effort training, a validated and recommended therapy, in patients with atheromatous cardiovascular disease. This true therapy reduces mortality by 25-35%, reduces clinical manifestations and complications (rhythm problems, thrombosis) and improves physical capacity, reintegration and quality of life. The effects are essentially linked to improved metabolic performance of muscles and reduced endothelial dysfunction, insulin resistance and neurohormonal abnormalities. Training also has an impact on the evolution of major risk factors, especially diabetes and arterial hypertension. The risks are limited as long as the contraindications are respected and the programmes supervised. The indications (stable angina, chronic heart failure, peripheral arterial disease) should be described more precisely by taking into account functional criteria: physical deconditioning, exclusion, compliance, mood swings, and seriousness of risk factors. The training programme should be tailor made and based on evaluation of the patient's adaptation to effort, in terms of frequency, intensity and duration of the exercises. Various types of exercise include overall or segmental physical training; concentric, eccentric, even isokinetic muscle contraction exercises; and proprioceptive rehabilitation. However, knowledge is lacking about the molecular mechanisms of the effects of training, the most effective intensity of effort, and strategies to develop physical activity in this ever-growing population for both primary and secondary prevention.
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Affiliation(s)
- J M Casillas
- Pôle rééducation-réadaptation, Inserm U887, CHU de Dijon, 23, rue Gaffarel, 21079 Dijon cedex, France.
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Abstract
The taste system, made up of taste receptor cells clustered in taste buds at the surface of the tongue and the soft palate, plays a key role in the decision to ingest or reject food and thereby is essential in protecting organisms against harmful toxins and in selecting the most appropriate nutrients. To determine if a similar chemosensory system exists in the gastrointestinal tract, we used immunohistochemistry and real-time polymerase chain reaction (PCR) to investigate which taste-signaling molecules are expressed in the intestinal mucosa. The PCR data showed that T1r1, T1r2, T1r3, alpha-gustducin, phospholipase Cbeta2 (PLCbeta2), and Trpm5 are expressed in the stomach, small intestine, and colon of mice and humans, with the exception of T1r2, which was not detected in the mouse and human stomach or in the mouse colon. Using transgenic mice expressing enhanced green fluorescent protein under the control of the Trpm5 promoter, we found colocalization of Trpm5 and alpha-gustducin in tufted cells at the surface epithelium of the colon, but these cells did not express T1r3 or PLCbeta2. In the duodenal glands, 43%, 33%, and 38% of Trpm5-expressing cells also express PLCbeta2, T1r3, or alpha-gustducin, respectively. The duodenal gland cells that coexpress PLCbeta2 and Trpm5 morphologically resemble enteroendocrine cells. We found a large degree of colocalization of Trpm5, alpha-gustducin, T1r1, and T1r3 in tufted cells of the duodenal villi, but these cells rarely expressed PLCbeta2. The data suggest that these duodenal cells are possibly involved in sensing amino acids.
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Affiliation(s)
- Carole Bezençon
- Nestlé Research Center, Vers-chez-les-Blanc, Lausanne, Switzerland
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Casillas JM, Damak S, Chauvet-Gelinier JC, Deley G, Ornetti P. Fatigue et maladies cardiovasculaires. ACTA ACUST UNITED AC 2006; 49:309-19, 392-402. [PMID: 16716433 DOI: 10.1016/j.annrmp.2006.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Accepted: 04/03/2006] [Indexed: 12/01/2022]
Abstract
Fatigue is a frequent complaint during cardiovascular disease and can sometimes constitute the first clinical manifestation of this disease. It is responsible for deterioration of the quality of life and prognosis. Although physical and mental fatigue are often intimately interrelated, these two aspects of fatigue correspond to different pathophysiological mechanisms and different clinical features and the neurobiological links between the two are only just beginning to be studied. Physical fatigue is related to loss of efficacy of the effector muscle, due to multiple causes: mismatch of cardiac output during exercise, muscle and microcirculatory deconditioning, neuroendocrine dysfunction, associated metabolic disorders. Mental fatigue corresponds to predominantly depressive mood disorders with a particular entity, vital exhaustion. The diagnostic approach is designed to eliminate other organic causes of fatigue. Functional tests investigating physical (exercise capacity) and mental dimensions (mood disorders) can be used to analyse their respective roles and to propose personalized management, in which rehabilitation has an essential place due to its global approach. The objective of this reduction of fatigue is threefold: to improve independence, to improve quality of life and to limit morbidity and mortality.
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Affiliation(s)
- J-M Casillas
- Inserm ERITm 0207, Pôle Rééducation-Réadaptation, CHU de Dijon, 23, rue Gaffarel, 21079 Dijon cedex, France.
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Abstract
The importance of alpha-gustducin in sweet taste transduction is based on data obtained with sucrose and the artificial sweetener SC45647. Here we studied the role of alpha-gustducin in sweet taste. We compared the behavioral and electrophysiological responses of alpha-gustducin knockout (KO) and wild-type (WT) mice to 11 different sweeteners, representing carbohydrates, artificial sweeteners, and sweet amino acids. In behavioral experiments, over 48-h preference ratios were measured in two-bottle preference tests. In electrophysiological experiments, integrated responses of chorda tympani (CT) and glossopharyngeal (NG) nerves were recorded. We found that preference ratios of the KO mice were significantly lower than those of WT for acesulfame-K, dulcin, fructose, NC00174, D-phenylalanine, L-proline, D-tryptophan, saccharin, SC45647, sucrose, but not neotame. The nerve responses to all sweeteners, except neotame, were smaller in the KO mice than in the WT mice. The differences between the responses in WT and KO mice were more pronounced in the CT than in the NG. These data indicate that alpha-gustducin participates in the transduction of the sweet taste in general.
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Affiliation(s)
- Vicktoria Danilova
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, WI, USA
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19
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Clapp TR, Medler KF, Damak S, Margolskee RF, Kinnamon SC. Mouse taste cells with G protein-coupled taste receptors lack voltage-gated calcium channels and SNAP-25. BMC Biol 2006; 4:7. [PMID: 16573824 PMCID: PMC1444931 DOI: 10.1186/1741-7007-4-7] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Accepted: 03/30/2006] [Indexed: 12/02/2022] Open
Abstract
Background Taste receptor cells are responsible for transducing chemical stimuli from the environment and relaying information to the nervous system. Bitter, sweet and umami stimuli utilize G-protein coupled receptors which activate the phospholipase C (PLC) signaling pathway in Type II taste cells. However, it is not known how these cells communicate with the nervous system. Previous studies have shown that the subset of taste cells that expresses the T2R bitter receptors lack voltage-gated Ca2+ channels, which are normally required for synaptic transmission at conventional synapses. Here we use two lines of transgenic mice expressing green fluorescent protein (GFP) from two taste-specific promoters to examine Ca2+ signaling in subsets of Type II cells: T1R3-GFP mice were used to identify sweet- and umami-sensitive taste cells, while TRPM5-GFP mice were used to identify all cells that utilize the PLC signaling pathway for transduction. Voltage-gated Ca2+ currents were assessed with Ca2+ imaging and whole cell recording, while immunocytochemistry was used to detect expression of SNAP-25, a presynaptic SNARE protein that is associated with conventional synapses in taste cells. Results Depolarization with high K+ resulted in an increase in intracellular Ca2+ in a small subset of non-GFP labeled cells of both transgenic mouse lines. In contrast, no depolarization-evoked Ca2+ responses were observed in GFP-expressing taste cells of either genotype, but GFP-labeled cells responded to the PLC activator m-3M3FBS, suggesting that these cells were viable. Whole cell recording indicated that the GFP-labeled cells of both genotypes had small voltage-dependent Na+ and K+ currents, but no evidence of Ca2+ currents. A subset of non-GFP labeled taste cells exhibited large voltage-dependent Na+ and K+ currents and a high threshold voltage-gated Ca2+ current. Immunocytochemistry indicated that SNAP-25 was expressed in a separate population of taste cells from those expressing T1R3 or TRPM5. These data indicate that G protein-coupled taste receptors and conventional synaptic signaling mechanisms are expressed in separate populations of taste cells. Conclusion The taste receptor cells responsible for the transduction of bitter, sweet, and umami stimuli are unlikely to communicate with nerve fibers by using conventional chemical synapses.
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Affiliation(s)
- Tod R Clapp
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
- Rocky Mountain Taste and Smell Center, UCDHSC, Aurora, CO, USA
| | - Kathryn F Medler
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
- Rocky Mountain Taste and Smell Center, UCDHSC, Aurora, CO, USA
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
| | - Sami Damak
- Department of Neuroscience, Mount Sinai School of Medicine, New York, NY, USA
- SD, Nestle Research Center, Vers-chez-les-Blanc, Lausanne, Switzerland
| | - Robert F Margolskee
- Dept. of Physiology and Biophysics, Mount. Sinai School of Medicine, New York, NY, USA
| | - Sue C Kinnamon
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
- Rocky Mountain Taste and Smell Center, UCDHSC, Aurora, CO, USA
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Damak S, Rong M, Yasumatsu K, Kokrashvili Z, Pérez CA, Shigemura N, Yoshida R, Mosinger B, Glendinning JI, Ninomiya Y, Margolskee RF. Trpm5 null mice respond to bitter, sweet, and umami compounds. Chem Senses 2006; 31:253-64. [PMID: 16436689 DOI: 10.1093/chemse/bjj027] [Citation(s) in RCA: 257] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Trpm5 is a calcium-activated cation channel expressed selectively in taste receptor cells. A previous study reported that mice with an internal deletion of Trpm5, lacking exons 15-19 encoding transmembrane segments 1-5, showed no taste-mediated responses to bitter, sweet, and umami compounds. We independently generated knockout mice null for Trpm5 protein expression due to deletion of Trpm5's promoter region and exons 1-4 (including the translation start site). We examined the taste-mediated responses of Trpm5 null mice and wild-type (WT) mice using three procedures: gustatory nerve recording [chorda tympani (CT) and glossopharyngeal (NG) nerves], initial lick responses, and 24-h two-bottle preference tests. With bitter compounds, the Trpm5 null mice showed reduced, but not abolished, avoidance (as indicated by licking responses and preference ratios higher than those of WT), a normal CT response, and a greatly diminished NG response. With sweet compounds, Trpm5 null mice showed no licking response, a diminished preference ratio, and absent or greatly reduced nerve responses. With umami compounds, Trpm5 null mice showed no licking response, a diminished preference ratio, a normal NG response, and a greatly diminished CT response. Our results demonstrate that the consequences of eliminating Trmp5 expression vary depending upon the taste quality and the lingual taste field examined. Thus, while Trpm5 is an important factor in many taste responses, its absence does not eliminate all taste responses. We conclude that Trpm5-dependent and Trpm5-independent pathways underlie bitter, sweet, and umami tastes.
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Affiliation(s)
- Sami Damak
- Department of Neuroscience, The Mount Sinai School of Medicine, 1 Gustave L. Levy Place, New York, NY 10029, USA
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He W, Yasumatsu K, Varadarajan V, Yamada A, Lem J, Ninomiya Y, Margolskee RF, Damak S. Umami taste responses are mediated by alpha-transducin and alpha-gustducin. J Neurosci 2005; 24:7674-80. [PMID: 15342734 PMCID: PMC6729622 DOI: 10.1523/jneurosci.2441-04.2004] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The sense of taste comprises at least five distinct qualities: sweet, bitter, sour, salty, and umami, the taste of glutamate. For bitter, sweet, and umami compounds, taste signaling is initiated by binding of tastants to G-protein-coupled receptors in specialized epithelial cells located in the taste buds, leading to the activation of signal transduction cascades. Alpha-gustducin, a taste cell-expressed G-protein alpha subunit closely related to the alpha-transducins, is a key mediator of sweet and bitter tastes. Alpha-gustducin knock-out (KO) mice have greatly diminished, but not entirely abolished, responses to many bitter and sweet compounds. We set out to determine whether alpha-gustducin also mediates umami taste and whether rod alpha-transducin (alpha(t-rod)), which is also expressed in taste receptor cells, plays a role in any of the taste responses that remain in alpha-gustducin KO mice. Behavioral tests and taste nerve recordings of single and double KO mice lacking alpha-gustducin and/or alpha(t-rod) confirmed the involvement of alpha-gustducin in bitter (quinine and denatonium) and sweet (sucrose and SC45647) taste and demonstrated the involvement of alpha-gustducin in umami [monosodium glutamate (MSG), monopotassium glutamate (MPG), and inosine monophosphate (IMP)] taste as well. We found that alpha(t-rod) played no role in taste responses to the salty, bitter, and sweet compounds tested or to IMP but was involved in the umami taste of MSG and MPG. Umami detection involving alpha-gustducin and alpha(t-rod) occurs in anteriorly placed taste buds, however taste cells at the back of the tongue respond to umami compounds independently of these two G-protein subunits.
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Affiliation(s)
- Wei He
- Department of Physiology and Biophysics, The Mount Sinai School of Medicine, New York, New York 10029, USA
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22
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Glendinning JI, Bloom LD, Onishi M, Zheng KH, Damak S, Margolskee RF, Spector AC. Contribution of alpha-gustducin to taste-guided licking responses of mice. Chem Senses 2005; 30:299-316. [PMID: 15800219 DOI: 10.1093/chemse/bji025] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We examined the necessity of alpha-gustducin, a G protein alpha-subunit expressed in taste cells, to taste-mediated licking responses of mice to sapid stimuli. To this end, we measured licking responses of alpha-gustducin knock-out (Gus-/-) mice and heterozygotic littermate controls (Gus+/-) to a variety of 'bitter', 'umami', 'sweet', 'salty' and 'sour' taste stimuli. All previous studies of how Gus-/- mice ingest taste stimuli have used long-term (i.e. 48 h) preference tests, which may be confounded by post-ingestive and/or experiential effects of the taste stimuli. We minimized these confounds by using a brief-access taste test, which quantifies immediate lick responses to extremely small volumes of sapid solutions. We found that deleting alpha-gustducin (i) dramatically reduced the aversiveness of a diverse range of 'bitter' taste stimuli; (ii) moderately decreased appetitive licking to low and intermediate concentrations of an 'umami' taste stimulus (monosodium glutamate in the presence of 100 microM amiloride), but virtually eliminated the normal aversion to high concentrations of the same taste stimulus; (iii) slightly decreased appetitive licking to 'sweet' taste stimuli; and (iv) modestly reduced the aversiveness of high, but not low or intermediate, concentrations of NaCl. There was no significant effect of deleting alpha-gustducin on licking responses to NH4Cl or HCl.
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Affiliation(s)
- John I Glendinning
- Department of Biological Science, Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, USA.
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23
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Damak S, Rong M, Yasumatsu K, Kokrashvili Z, Varadarajan V, Zou S, Jiang P, Ninomiya Y, Margolskee RF. Detection of sweet and umami taste in the absence of taste receptor T1r3. Science 2003; 301:850-3. [PMID: 12869700 DOI: 10.1126/science.1087155] [Citation(s) in RCA: 437] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The tastes of sugars (sweet) and glutamate (umami) are thought to be detected by T1r receptors expressed in taste cells. Molecular genetics and heterologous expression implicate T1r2 plus T1r3 as a sweet-responsive receptor,and T1r1 plus T1r3,as well as a truncated form of the type 4 metabotropic glutamate receptor (taste-mGluR4),as umami-responsive receptors. Here,we show that mice lacking T1r3 showed no preference for artificial sweeteners and had diminished but not abolished behavioral and nerve responses to sugars and umami compounds. These results indicate that T1r3-independent sweet- and umami-responsive receptors and/or pathways exist in taste cells.
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Affiliation(s)
- Sami Damak
- Department of Biophysics and Physiology, Mount Sinai School of Medicine, Box 1677, 1425 Madison Avenue, New York, NY 10029, USA
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He W, Danilova V, Zou S, Hellekant G, Max M, Margolskee RF, Damak S. Partial rescue of taste responses of alpha-gustducin null mice by transgenic expression of alpha-transducin. Chem Senses 2002; 27:719-27. [PMID: 12379596 DOI: 10.1093/chemse/27.8.719] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The transduction of responses to bitter and sweet compounds utilizes guanine nucleotide binding proteins (G proteins) and their coupled receptors. Alpha-gustducin, a transducin-like G protein alpha-subunit, and rod alpha-transducin are expressed in taste receptor cells. Alpha-gustducin knockout mice have profoundly diminished behavioral and electrophysiological responses to many bitter and sweet compounds, although these mice retain residual responses to these compounds. Alpha-gustducin and rod alpha-transducin are biochemically indistinguishable in their in vitro interactions with retinal phosphodiesterase, rhodopsin and G protein betagamma-subunits. To determine if alpha-transducin can function in taste receptor cells and to compare the function of alpha-gustducin versus alpha-transducin in taste transduction in vivo, we generated transgenic mice that express alpha-transducin under the control of the alpha-gustducin promoter in the alpha-gustducin null background. Immunohistochemistry showed that the alpha-transducin transgene was expressed in about two-thirds of the alpha-gustducin lineage of taste receptor cells. Two-bottle preference tests showed that transgenic expression of rod alpha-transducin partly rescued responses to denatonium benzoate, sucrose and the artificial sweetener SC45647, but not to quinine sulfate. Gustatory nerve recordings showed a partial rescue by the transgene of the response to sucrose, SC45647 and quinine, but not to denatonium. These results demonstrate that alpha-transducin can function in taste receptor cells and transduce some taste cell responses. Our results also suggest that alpha-transducin and alpha-gustducin may differ, at least in part, in their function in these cells, although this conclusion must be qualified because of the limited fidelity of the transgene expression.
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Affiliation(s)
- Wei He
- Department of Physiology and Biophysics, Howard Hughes Medical Institute, Mount Sinai School of Medicine, 1425 Madison Avenue, Box 1677, New York, NY 10029, USA
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Hanboonsong Y, Choosai C, Panyim S, Damak S. Transovarial transmission of sugarcane white leaf phytoplasma in the insect vector Matsumuratettix hiroglyphicus (Matsumura). Insect Mol Biol 2002; 11:97-103. [PMID: 11841507 DOI: 10.1046/j.0962-1075.2001.00314.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
White leaf is a serious disease of sugarcane caused by phytoplasma. The disease is transmitted to the plant by the leafhopper Matsumuratettix hiroglyphicus (Matsumura). The reservoir of phytoplasma was suspected to be weeds that grow in sugarcane farming areas because they can be infected with phytoplasma and show symptoms similar to sugarcane white leaf. However in previous work we have demonstrated by RFLP and sequencing that this is not the case. Here we have reared M. hiroglyphicus through two generations by feeding them phytoplasma free sugarcane grown from tissue culture. By nested-PCR followed by sequencing, we demonstrated the presence of the phytoplasma in eggs, nymphs and adults of the first and second generations thereby showing transovarial transmission. We have also shown by in situ PCR that phytoplasmas were widely distributed throughout the body of the insect. RFLP and sequencing showed that the same phytoplasma was present in the vector and in the plant. Together, these data point to the leafhopper M. hiroglyphicus as the reservoir of phytoplasma that cause sugarcane white leaf disease.
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Affiliation(s)
- Y Hanboonsong
- Department of Entomology, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
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26
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Ruiz-Avila L, Wong GT, Damak S, Margolskee RF. Dominant loss of responsiveness to sweet and bitter compounds caused by a single mutation in alpha -gustducin. Proc Natl Acad Sci U S A 2001; 98:8868-73. [PMID: 11447270 PMCID: PMC37527 DOI: 10.1073/pnas.151235798] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biochemical and genetic studies have implicated alpha-gustducin as a key component in the transduction of both bitter or sweet taste. Yet, alpha-gustducin-null mice are not completely unresponsive to bitter or sweet compounds. To gain insights into how gustducin mediates responses to bitter and sweet compounds, and to elicit the nature of the gustducin-independent pathways, we generated a dominant-negative form of alpha-gustducin and expressed it as a transgene from the alpha-gustducin promoter in both wild-type and alpha-gustducin-null mice. A single mutation, G352P, introduced into the C-terminal region of alpha-gustducin critical for receptor interaction rendered the mutant protein unresponsive to activation by taste receptor, but left its other functions intact. In control experiments, expression of wild-type alpha-gustducin as a transgene in alpha-gustducin-null mice fully restored responsiveness to bitter and sweet compounds, formally proving that the targeted deletion of the alpha-gustducin gene caused the taste deficits of the null mice. In contrast, transgenic expression of the G352P mutant did not restore responsiveness of the null mice to either bitter or sweet compounds. Furthermore, in the wild-type background, the mutant transgene inhibited endogenous alpha-gustducin's interactions with taste receptors, i.e., it acted as a dominant-negative. That the mutant transgene further diminished the residual bitter and sweet taste responsiveness of the alpha-gustducin-null mice suggests that other guanine nucleotide-binding regulatory proteins expressed in the alpha-gustducin lineage of taste cells mediate these responses.
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Affiliation(s)
- L Ruiz-Avila
- Howard Hughes Medical Institute, Department of Physiology and Biophysics, Mount Sinai School of Medicine, Box 1677, One Gustave L. Levy Place, New York, NY 10029, USA.
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Max M, Shanker YG, Huang L, Rong M, Liu Z, Campagne F, Weinstein H, Damak S, Margolskee RF. Tas1r3, encoding a new candidate taste receptor, is allelic to the sweet responsiveness locus Sac. Nat Genet 2001; 28:58-63. [PMID: 11326277 DOI: 10.1038/ng0501-58] [Citation(s) in RCA: 296] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ability to taste the sweetness of carbohydrate-rich foodstuffs has a critical role in the nutritional status of humans. Although several components of bitter transduction pathways have been identified, the receptors and other sweet transduction elements remain unknown. The Sac locus in mouse, mapped to the distal end of chromosome 4 (refs. 7-9), is the major determinant of differences between sweet-sensitive and -insensitive strains of mice in their responsiveness to saccharin, sucrose and other sweeteners. To identify the human Sac locus, we searched for candidate genes within a region of approximately one million base pairs of the sequenced human genome syntenous to the region of Sac in mouse. From this search, we identified a likely candidate: T1R3, a previously unknown G protein-coupled receptor (GPCR) and the only GPCR in this region. Mouse Tas1r3 (encoding T1r3) maps to within 20,000 bp of the marker closest to Sac (ref. 9) and, like human TAS1R3, is expressed selectively in taste receptor cells. By comparing the sequence of Tas1r3 from several independently derived strains of mice, we identified a specific polymorphism that assorts between taster and non-taster strains. According to models of its structure, T1r3 from non-tasters is predicted to have an extra amino-terminal glycosylation site that, if used, would interfere with dimerization.
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Affiliation(s)
- M Max
- Department of Physiology and Biophysics, Mount Sinai School of Medicine of New York University, New York, New York, USA
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Abstract
Taste receptor cells use a variety of mechanisms to transduce chemical information into cellular signals. Seven-transmembrane-helix receptors initiate signaling cascades by coupling to G proteins, effector enzymes, second messengers and ion channels. Apical ion channels pass ions, leading to depolarizing and/or hyperpolarizing responses. New insights into the mechanisms of taste sensation have been gained from molecular cloning of the transduction elements, biochemical elucidation of the transduction pathways, and electrophysiological analysis of the function of taste cell ion channels.
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Affiliation(s)
- T A Gilbertson
- Department of Biology, Utah State University, Logan 84322-5305, USA.
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30
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Abstract
An Australian Merino flock was screened for low (resistant) and high (susceptible) yellow predictive colour (YPC) breeding values in order to compare extreme individuals using the differential display of mRNA technique. One differentially expressed cDNA band was visualised only in the resistant group. This band showed no identity with the DNA sequences of public databases; however, they showed short homologies with three database sequences related to transmembrane signalling functions. The use of these candidate genes as DNA markers needs to be confirmed against sheep with a wide range of susceptibility to wool yellowing to verify the results.
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Abstract
Mutations in different genes underlie different forms of the neuronal ceroid lipofuscinoses (NCLs, Batten disease). Subunit c of mitochondrial ATP synthase specifically accumulates in most of them, including the juvenile CLN3 form and a sheep form orthologous to CLN6. Products of these genes are likely to be components of a complex or pathway for subunit c turnover, and their expression may be cross-regulated. Different bands, some with different subcellular distributions, were detected by antisera against different regions of CLN3 on Western blots of sheep tissues. Affected liver blots were the same as controls but a specific 50-kDa band was at higher concentration in affected brain homogenates than in controls. Others have also reported bands reacting differently to different CLN3 antibodies. When the 3' end of sheep CLN3 cDNA was amplified by RT-PCR, four mRNA splicing variants were found. Different CLN3 splicing variants at the 5' end of the human cDNA have been reported. These mRNA splicing variants may account the variation of epitope distribution and the different subcellular locations of the CLN3 gene product(s). The predicted size of the unmodified CLN3 protein is 48 kDa. Significantly higher molecular weight bands may correspond to oligomers of a CLN3 isoform or to a CLN3 isoform tightly bound to another protein.
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Affiliation(s)
- M J Oswald
- Animal and Food Sciences Division, Lincoln University, Canterbury, New Zealand
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Su HY, Jay NP, Gourley TS, Kay GW, Damak S. Wool production in transgenic sheep: results from first-generation adults and second-generation lambs. Anim Biotechnol 1998; 9:135-47. [PMID: 9713678 DOI: 10.1080/10495399809525900] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In sheep transgenic for a sheep insulin-like growth factor 1 (IGF-1) cDNA driven by a mouse keratin promoter, we assessed wool production and properties in 51 adults of the first generation (G1) and in 56 lambs of the second generation (G2). Transgenic G1 sheep had an increased rate of wool production during spring and summer of year 2 compared with nontransgenic half-sibs, with a maximum increase of 17% in December, but during the winter nadir rates were similar. At second- and third-year shearing, however, fleece weights were not significantly different. There was a trend for transgenic animals to have coarser wool of lower staple strength. A controlled feeding trial revealed no significant differences in feed intake. The transgene was expressed not only in skin but also in a wide range of other tissues. Circulating IGF-1 concentrations were not significantly different between transgenic and nontransgenic animals, suggesting that local mechanisms were more important than systemic mechanisms for wool production, but were significantly higher in males than in females. In the G2 sheep, transgenic fleece weight did not differ significantly from nontransgenic either as lambs or at the end of the lamb year. Although the transgene was inherited in Mendelian fashion and was widely expressed, the production advantage seen in animals of the first generation did not persist in the second generation.
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Affiliation(s)
- H Y Su
- Animal and Veterinary Sciences Group, Lincoln University, Canterbury, New Zealand
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Damak S, Harnboonsong Y, George PM, Bullock DW. Expression of human Krev-1 gene in lungs of transgenic mice and subsequent reduction in multiplicity of ethyl carbamate-induced lung adenomas. Mol Carcinog 1996; 17:84-91. [PMID: 8890957 DOI: 10.1002/(sici)1098-2744(199610)17:2<84::aid-mc5>3.0.co;2-t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mice of the A/J strain are useful models of lung cancer because they develop tumors spontaneously or after treatment with ethyl carbamate. These tumors are thought to arise from either Clara cells (papillary tumors) or alveolar type 2 cells (alveolar tumors); like many human lung adenocarcinomas, the mouse tumors involve Kiras activation. Transformation with Ki-ras can be reversed by coexpression of the Krev-1 gene in tissue culture. To test the tumor suppressor activity of Krev-1 in vivo, we produced transgenic A/J mice expressing Krev-1 under the control of the rabbit uteroglobin promoter, which directs expression of heterologous genes to the lung Clara cells. Krev-1 was expressed specifically in the lungs of transgenic mice. Sixty-six mice (35 transgenic and 31 nontransgenic) from three lines were given ethyl carbamate, and the numbers of resulting lung tumors were compared between transgenic and nontransgenic animals. The mean number (+/-standard deviation) of ethyl carbamate-induced lung tumors was 21.7 +/- 1.3 in transgenic mice and 26.9 +/- 1.3 in their nontransgenic littermates (P < 0.01). Sequencing of polymerase chain reaction-amplified ras DNA from 15 transgenic mouse tumors and 16 nontransgenic mouse tumors (controls) detected mutations in codon 61 in 13 tumors from the transgenic group and 11 tumors in the control group, whereas mutations in codon 12 were detected in only one tumor in the transgenic group and in four tumors in the controls. Together, these data demonstrate for the first time the tumor suppressor activity of Krev-1 in vivo and suggest that Krev-1 tumor suppressor activity may be specific for cells harboring mutations in codon 12 of ras.
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Affiliation(s)
- S Damak
- Centre for Molecular Biology, Lincoln University, Canterbury, New Zealand
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Damak S, Su H, Jay NP, Bullock DW. Improved wool production in transgenic sheep expressing insulin-like growth factor 1. Biotechnology (N Y) 1996; 14:185-8. [PMID: 9636321 DOI: 10.1038/nbt0296-185] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transgenic sheep were produced by pronuclear microinjection with a mouse ultra-high-sulfur keratin promoter linked to an ovine insulin-like growth factor 1 (IGF1) cDNA. Five transgenic lambs resulted from the microinjection of 591 embryos; one male and one female showed IGF1 expression in the skin. A progeny test of the ram was carried out by matings to 43 non-transgenic ewes. Of 85 lambs born, 43 (50.6%) were transgenic. At yearling shearing (approximately 14 months of age), clean fleece weight was on average 6.2% greater in transgenic animals than in their non-transgenic half-sibs, with a greater effect in males (9.2%) than females (3.4%). Transgenics showed a small but significant increase in bulk, but male transgenics had a lower staple strength than female transgenics and non-transgenics which did not differ significantly. There were no significant differences in fiber diameter, medullation, and hogget body weight. To our knowledge this is the first reported improvement in a production trait by genetic engineering of a farm animal without adverse effects on health or reproduction.
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Affiliation(s)
- S Damak
- Centre for Molecular Biology, Lincoln University, Canterbury, New Zealand
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Abstract
To establish the feasibility of overexpressing foreign genes in the wool follicle, transgenic sheep were produced by pronuclear microinjection of a DNA construct consisting of a mouse ultrahigh-sulfur keratin promoter linked to the bacterial chloramphenicol acetyl transferase (CAT) gene. Four of 31 lambs born were transgenic. The overall efficiency of transgenesis was 1.1% of zygotes injected and transferred. Two transgenic rams were mated to nontransgenic ewes, and both transmitted the gene to their offspring in Mendelian fashion. CAT expression was found in the skin of one G0 ram and in 9 out of 26 transgenic G1 progeny. Two G1 lambs were sacrificed to study tissue specificity. Both had high levels of expression in skin but One had high expression in spleen and kidney with lower levels of expression in lung; the other had low expression in spleen, lung, and muscle. In situ hybridization demonstrated that transgene expression in the skin was confined to the keratogenous zone of the wool follicle cortex. Expression of CAT activity in skin was correlated with diet-induced or seasonal changes in the rate of wool growth. This keratin promoter appears useful for overexpressing factors in the wool follicle that might influence wool production or properties.
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Affiliation(s)
- S Damak
- Centre for Molecular Biology, Lincoln University, Canterbury, New Zealand
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Clark AJ, Bissinger P, Bullock DW, Damak S, Wallace R, Whitelaw CB, Yull F. Chromosomal position effects and the modulation of transgene expression. Reprod Fertil Dev 1994; 6:589-98. [PMID: 7569038 DOI: 10.1071/rd9940589] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Chromosomal position effects can influence strongly the transcription of foreign genes in transgenic animals. This results in low frequencies and levels of gene expression and, in some cases, in aberrant patterns of expression. Strategies for overcoming these effects are described with particular reference to their application in embryonic stem cells.
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Affiliation(s)
- A J Clark
- AFRC Roslin Institute, Midlothian, Scotland, UK
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Damak S, Bullock DW. A simple two-step method for efficient blunt-end ligation of DNA fragments. Biotechniques 1993; 15:448-50, 452. [PMID: 8217157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The formation of recombinant plasmids results from ligation between one end of the linearized vector and one end of the insert (favored by high DNA concentration), followed by self-ligation of the newly created hybrid molecule (favored by low DNA concentration). Standard protocols recommend an average DNA concentration at which both events may occur. Since this DNA concentration is not optimum for both ligation events, efficient blunt-end ligation is compromised. We describe a method for blunt-end ligation starting at a high DNA concentration for 1 h then at 1/20 the initial DNA concentration overnight. The number of recombinant plasmids obtained with this method is about 10-fold higher than with standard protocols. Restriction digestion and agarose gel electrophoresis of 10 recombinant plasmids obtained with the two-step ligation method showed that all plasmids contained one copy of the insert.
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Affiliation(s)
- S Damak
- Centre for Molecular Biology, Lincoln University, Canterbury, New Zealand
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Abstract
The rabbit uteroglobin (UG) gene, with varying lengths of 5' flanking sequence, was introduced into the mouse genome to investigate the DNA sequences required for tissue-specific expression and regulation by steroid hormones. The pattern of expression and steroid hormone regulation of the transgene was compared to the expression and regulation of the endogenous mouse UG-like gene. In the rabbit, UG is induced in the uterus by progesterone and is expressed constitutively in the lungs, where it is weakly regulated by glucocorticoids. Genomic DNA fragments containing the complete UG-coding sequence with 4.0 (UG4.0), 3.0 (UG3.0), 2.3 (UG2.3), or 0.6 (UG0.6) kilobases of 5' flanking sequence were used to establish lines of transgenic mice. Expression of UG mRNA was observed in the lungs of UG4.0 (2/4 lines), UG3.0 (4/4 lines), UG2.3 (1/2 lines), and UG0.6 (4/4 lines) mice. Uterine expression was observed in UG3.0 (3/4 lines), UG2.3 (1/2 lines), and UG0.6 (2/4 lines). In the lungs of UG3.0 and UG2.3 mice, RNA expression was stimulated by treatment with dexamethasone. In the one line of UG3.0 mice examined, UG was regulated by ovarian steroids in the uterus. The endogenous mouse UG-like gene showed the major site of expression to be in the lung. Unlike the transgene, the endogenous gene was more strongly stimulated by glucocorticoids. Thus, we conclude that the cis elements needed for pulmonary expression of UG are contained within the UG2.3 fragment used to generate transgenic mice, but that other elements are required for full glucocorticoid regulation. Also, the transgene did not show the full uterine expression observed in the rabbit, but regulation by the ovarian steroids was observed.
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Affiliation(s)
- F J DeMayo
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030
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