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Braden ML, Gwin JA, Leidy HJ. Examining the Direct and Indirect Effects of Postprandial Amino Acid Responses on Markers of Satiety following the Acute Consumption of Lean Beef-Rich Meals in Healthy Women with Overweight. Nutrients 2024; 16:1718. [PMID: 38892651 PMCID: PMC11174850 DOI: 10.3390/nu16111718] [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: 04/30/2024] [Revised: 05/25/2024] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
The consumption of protein-rich foods stimulates satiety more than other macronutrient-rich foods; however, the underlying mechanisms-of-action are not well-characterized. The objective of this study was to identify the direct and indirect effects of postprandial amino acid (AA) responses on satiety. Seventeen women (mean ± SEM, age: 33 ± 1 year; BMI: 27.8 ± 0.1 kg/m2) consumed a eucaloric, plant-based diet containing two servings of lean beef/day (i.e., 7.5 oz (207 g)) for 7 days. During day 6, the participants completed a 12 h controlled-feeding, clinical testing day including repeated satiety questionnaires and blood sampling to assess pre- and postprandial plasma AAs, PYY, and GLP-1. Regression and mediation analyses were completed to assess AA predictors and hormonal mediators. Total plasma AAs explained 41.1% of the variance in perceived daily fullness (p < 0.001), 61.0% in PYY (p < 0.001), and 66.1% in GLP-1 (p < 0.001) concentrations, respectively. Several individual AAs significantly predicted fluctuations in daily fullness, PYY, and GLP-1. In completing mediation analyses, the effect of plasma leucine on daily fullness was fully mediated by circulating PYY concentrations (indirect effect = B: 0.09 [Boot 95% CI: 0.032, 0.17]) as no leucine-fullness direct effect was observed. No other mediators were identified. Although a number of circulating AAs predict satiety, leucine was found to do so through changes in PYY concentrations in middle-aged women.
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Affiliation(s)
- Morgan L. Braden
- Department of Nutritional Sciences, University of Texas at Austin, Austin, TX 78723, USA;
- Department of Pediatrics, Dell Medical School, University of Texas at Austin, Austin, TX 78723, USA
| | - Jess A. Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA;
| | - Heather J. Leidy
- Department of Nutritional Sciences, University of Texas at Austin, Austin, TX 78723, USA;
- Department of Pediatrics, Dell Medical School, University of Texas at Austin, Austin, TX 78723, USA
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Watkins JD, Smith HA, Hengist A, Nielsen SB, Mikkelsen UR, Saunders J, Koumanov F, Betts JA, Gonzalez JT. Effects of physical form of β-lactoglobulin and calcium ingestion on GLP-1 secretion, gastric emptying and energy intake in humans: a randomised crossover trial. Br J Nutr 2024; 131:1730-1739. [PMID: 38287700 PMCID: PMC11063665 DOI: 10.1017/s0007114524000321] [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: 07/07/2023] [Revised: 01/03/2024] [Accepted: 01/25/2024] [Indexed: 01/31/2024]
Abstract
The aim of this study was to assess whether adding Ca2+ to aggregate or native forms of β-lactoglobulin alters gut hormone secretion, gastric emptying rates and energy intake in healthy men and women. Fifteen healthy adults (mean ± sd: 9M/6F, age: 24 ± 5 years) completed four trials in a randomised, double-blind, crossover design. Participants consumed test drinks consisting of 30 g of β-lactoglobulin in a native form with (NATIVE + MINERALS) and without (NATIVE) a Ca2+-rich mineral supplement and in an aggregated form both with (AGGREG + MINERALS) and without the mineral supplement (AGGREG). Arterialised blood was sampled for 120 min postprandially to determine gut hormone concentrations. Gastric emptying was determined using 13C-acetate and 13C-octanoate, and energy intake was assessed with an ad libitum meal at 120 min. A protein × mineral interaction effect was observed for total glucagon-like peptide-1 (GLP-1TOTAL) incremental AUC (iAUC; P < 0·01), whereby MINERALS + AGGREG increased GLP-1TOTAL iAUC to a greater extent than AGGREG (1882 ± 603 v. 1550 ± 456 pmol·l-1·120 min, P < 0·01), but MINERALS + NATIVE did not meaningfully alter the GLP-1 iAUC compared with NATIVE (1669 ± 547 v. 1844 ± 550 pmol·l-1·120 min, P = 0·09). A protein × minerals interaction effect was also observed for gastric emptying half-life (P < 0·01) whereby MINERALS + NATIVE increased gastric emptying half-life compared with NATIVE (83 ± 14 v. 71 ± 8 min, P < 0·01), whereas no meaningful differences were observed between MINERALS + AGGREG v. AGGREG (P = 0·70). These did not result in any meaningful changes in energy intake (protein × minerals interaction, P = 0·06). These data suggest that the potential for Ca2+ to stimulate GLP-1 secretion at moderate protein doses may depend on protein form. This study was registered at clinicaltrials.gov (NCT04659902).
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Affiliation(s)
- Jonathan D. Watkins
- Centre for Nutrition, Exercise and Metabolism, Department for Health, University of Bath, Bath, UK
| | - Harry A. Smith
- Centre for Nutrition, Exercise and Metabolism, Department for Health, University of Bath, Bath, UK
| | - Aaron Hengist
- Centre for Nutrition, Exercise and Metabolism, Department for Health, University of Bath, Bath, UK
| | | | | | | | - Francoise Koumanov
- Centre for Nutrition, Exercise and Metabolism, Department for Health, University of Bath, Bath, UK
| | - James A. Betts
- Centre for Nutrition, Exercise and Metabolism, Department for Health, University of Bath, Bath, UK
| | - Javier T. Gonzalez
- Centre for Nutrition, Exercise and Metabolism, Department for Health, University of Bath, Bath, UK
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Tough IR, Lund ML, Patel BA, Schwartz TW, Cox HM. Paracrine relationship between incretin hormones and endogenous 5-hydroxytryptamine in the small and large intestine. Neurogastroenterol Motil 2023; 35:e14589. [PMID: 37010838 PMCID: PMC10909488 DOI: 10.1111/nmo.14589] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 02/13/2023] [Accepted: 03/21/2023] [Indexed: 04/04/2023]
Abstract
BACKGROUND Enterochromaffin (EC) cell-derived 5-hydroxytryptamine (5-HT) is a mediator of toxin-induced reflexes, initiating emesis via vagal and central 5-HT3 receptors. The amine is also involved in gastrointestinal (GI) reflexes that are prosecretory and promotile, and recently 5-HT's roles in chemosensation in the distal bowel have been described. We set out to establish the efficacy of 5-HT signaling, local 5-HT levels and pharmacology in discrete regions of the mouse small and large intestine. We also investigated the inter-relationships between incretin hormones, glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) and endogenous 5-HT in mucosal and motility assays. METHODS Adult mouse GI mucosae were mounted in Ussing chambers and area-specific studies were performed to establish the 5-HT3 and 5-HT4 pharmacology, the sidedness of responses, and the inter-relationships between incretins and endogenous 5-HT. Natural fecal pellet transit in vitro and full-length GI transit in vivo were also measured. KEY RESULTS We observed the greatest level of tonic and exogenous 5-HT-induced ion transport and highest levels of 5-HT in ascending colon mucosa. Here both 5-HT3 and 5-HT4 receptors were involved but elsewhere in the GI tract epithelial basolateral 5-HT4 receptors mediate 5-HT's prosecretory effect. Exendin-4 and GIP induced 5-HT release in the ascending colon, while L cell-derived PYY also contributed to GIP mucosal effects in the descending colon. Both peptides slowed colonic transit. CONCLUSIONS & INFERENCES We provide functional evidence for paracrine interplay between 5-HT, GLP-1 and GIP, particularly in the colonic mucosal region. Basolateral epithelial 5-HT4 receptors mediated both 5-HT and incretin mucosal responses in healthy colon.
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Affiliation(s)
- Iain R. Tough
- Wolfson Centre for Age‐Related Diseases, Institute of Psychology, Psychiatry and NeuroscienceKing's College LondonHodgkin Building, Guy's CampusLondonSE1 1ULUK
| | - Mari L. Lund
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, Section for Metabolic Receptology and EnteroendocrinologyUniversity of CopenhagenCopenhagenDK‐2200Denmark
- Present address:
Chr. Hansen A/S, Human Health ResearchHoersholmDK‐2970Denmark
| | - Bhavik A. Patel
- Centre for Stress and Age‐Related Diseases, School of Applied SciencesUniversity of BrightonBrightonUK
| | - Thue W. Schwartz
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, Section for Metabolic Receptology and EnteroendocrinologyUniversity of CopenhagenCopenhagenDK‐2200Denmark
| | - Helen M. Cox
- Wolfson Centre for Age‐Related Diseases, Institute of Psychology, Psychiatry and NeuroscienceKing's College LondonHodgkin Building, Guy's CampusLondonSE1 1ULUK
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Chu F, Wan H, Xiao W, Dong H, Lü M. Ca 2+-Permeable Channels/Ca 2+ Signaling in the Regulation of Ileal Na +/Gln Co-Transport in Mice. Front Pharmacol 2022; 13:816133. [PMID: 35281933 PMCID: PMC8905502 DOI: 10.3389/fphar.2022.816133] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/13/2022] [Indexed: 11/13/2022] Open
Abstract
Oral glutamine (Gln) has been widely used in gastrointestinal (GI) clinical practice, but it is unclear if Ca2+ regulates intestinal Gln transport, although both of them are essential nutrients for mammals. Chambers were used to determine Gln (25 mM)-induced Isc through Na+/Gln co-transporters in the small intestine in the absence or the presence of selective activators or blockers of ion channels and transporters. Luminal but not serosal application of Gln induced marked intestinal Isc, especially in the distal ileum. Lowering luminal Na+ almost abolished the Gln-induced ileal Isc, in which the calcium-sensitive receptor (CaSR) activation were not involved. Ca2+ removal from both luminal and serosal sides of the ileum significantly reduced Gln- Isc. Blocking either luminal Ca2+ entry via the voltage-gated calcium channels (VGCC) or endoplasmic reticulum (ER) release via inositol 1,4,5-triphosphate receptor (IP3R) and ryanodine receptor (RyR) attenuated the Gln-induced ileal Isc, Likewise, blocking serosal Ca2+ entry via the store-operated Ca2+ entry (SOCE), TRPV1/2 channels, and Na+/Ca2+ exchangers (NCX) attenuated the Gln-induced ileal Isc. In contrast, activating TRPV1/2 channels enhanced the Gln-induced ileal Isc. We concluded that Ca2+ signaling is critical for intestinal Gln transport, and multiple plasma membrane Ca2+-permeable channels and transporters play roles in this process. The Ca2+ regulation of ileal Na+/Gln transport expands our understanding of intestinal nutrient uptake and may be significant in GI health and disease.
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Affiliation(s)
- Fenglan Chu
- Department of Gastroenterology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Hanxing Wan
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Weidong Xiao
- Department of General Surgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Hui Dong
- Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Muhan Lü
- Department of Gastroenterology, Affiliated Hospital of Southwest Medical University, Luzhou, China
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Wang L, Ding L, Zhu W, Hang S. Soybean protein hydrolysate stimulated cholecystokinin secretion and inhibited feed intake through calcium-sensing receptors and intracellular calcium signalling in pigs. Food Funct 2021; 12:9286-9299. [PMID: 34606544 DOI: 10.1039/d1fo01596f] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although soybean protein is the major component in livestock feeds, its effect on pigs' appetites is largely unknown. Recently, the importance of gut nutrient-sensing for appetite modulation by regulating anorectic gut hormone release has been recognised. This study investigates the roles of soybean proteins in appetite regulation, anorectic gut hormone secretion, and underlying mechanisms. The duodenal-cannulated piglets were used to evaluate the effects of soybean protein hydrolysate (SPH) on feed intake and anorectic hormone release, including cholecystokinin (CCK), peptide YY (PYY), glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) in the hepatic vein by infusing SPH. Identifying which nutrient-sensing receptor in pig duodenum response to SPH stimulation for gut hormone release was conducted. Using its antagonist, the role of the identified receptor in feed intake and anorectic hormone release was also investigated. Combination with an ex vivo perfusion system, the possible mechanism by which SPH exerts the effects in porcine duodenum was further illustrated. Results in vivo showed that intraduodenal infusion of SPH inhibited short-term feed intake in pigs and promoted CCK, PYY, and GIP secretion in the hepatic vein. SPH also increased duodenum calcium-sensing receptor (CaSR) expression. Pre-treated with CaSR antagonist NPS 2143, the feed intake of pigs tended to be attenuated by SPH (P = 0.09), and CCK release was also suppressed (P < 0.05), indicating that CaSR was involved in SPH-stimulated CCK release and inhibited feed intake in pigs. The ex vivo perfused duodenum tissues revealed that SPH-triggered CCK secretion was likeliest due to the activation of the intracellular Ca2+/TRPM5 pathway. Overall, this study's result illustrates that the diet soybean protein might decrease appetite in pigs by triggering duodenum CCK secretion by activating CaSR and the intracellular Ca2+/TRPM5 pathway.
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Affiliation(s)
- Lvyang Wang
- National Center for International Research on Animal Gut Nutrition, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing 210095, China.
| | - Liren Ding
- National Experimental Teaching Center for Animal Science, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiyun Zhu
- National Center for International Research on Animal Gut Nutrition, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing 210095, China.
| | - Suqin Hang
- National Center for International Research on Animal Gut Nutrition, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing 210095, China.
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Guo S, Yan T, Shi L, Liu A, Zhang T, Xu Y, Jiang W, Yang Q, Yang L, Liu L, Zhao R, Zhang S. Matrine, as a CaSR agonist promotes intestinal GLP-1 secretion and improves insulin resistance in diabetes mellitus. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 84:153507. [PMID: 33636577 DOI: 10.1016/j.phymed.2021.153507] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/02/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Matrine (Mat), a bitter tastes compounds of derived from leguminosae such as Sophora flavescens and S. subprostrata, commonly used to improve obesity and diabetes. PURPOSE Our study to demonstrate bitter substances can stimulate the Bitter taste receptors (TAS2Rs) or Calcium-sensing receptor (CaSR) to stimulate the secretion of GLP-1 to promote blood glucose regulation. METHODS The diabetic mice and intestinal secretory cell model were established to evaluate the Mat on glucose metabolism, intestinal insulin secretion and GLP-1 secretion related substances. To clarify the mechanism of Mat in regulating GLP-1 secretion by immunofluorescence, calcium labeling, siRNA, and molecular docking. RESULTS The results showed that Mat could significantly improve glucose metabolism and increased insulin and GLP-1 secretion in diabetic mice and increased trisphosphate inositol (IP3) levels by affecting the expression of phospholipase C β2 (PLCβ2) and promote an increase in intracellular Ca2+ levels in STC-1 cells to subsequently stimulate the secretion of GLP-1. Knockdown of the bitter taste receptors mTas2r108, mTas2r137, and mTas2r138 in STC-1 cells by siRNA did could not affect the role of Mat in regulating GLP-1. However, the secretion of GLP-1 by Mat could be significantly inhibited by administration of a CaSR inhibitor or siRNA CaSR. Molecular docking analysis showed that Mat could embed CaSR protein and bind to the original ligand of the egg white at the same amino acid site to play the role of an agonist. CONCLUSION Matrine is a typical bitter alkaloid could be used as an agonist of CaSR to stimulate the secretion of GLP-1 in the intestine, and it may be used as a potential drug for diabetes treatment.
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Affiliation(s)
- Shun Guo
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Tao Yan
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Lei Shi
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - An Liu
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Tian Zhang
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Yuan Xu
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Wei Jiang
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Qi Yang
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Le Yang
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China
| | - Linna Liu
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China..
| | - Rong Zhao
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Air Force Medical University, Xi'an 710032, PR China..
| | - Song Zhang
- Department of Pharmacy, The Second Affiliated Hospital of Air Force Medical University, Xi'an, 710038, PR China..
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Lu VB, Gribble FM, Reimann F. Nutrient-Induced Cellular Mechanisms of Gut Hormone Secretion. Nutrients 2021; 13:nu13030883. [PMID: 33803183 PMCID: PMC8000029 DOI: 10.3390/nu13030883] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/27/2021] [Accepted: 03/05/2021] [Indexed: 02/06/2023] Open
Abstract
The gastrointestinal tract can assess the nutrient composition of ingested food. The nutrient-sensing mechanisms in specialised epithelial cells lining the gastrointestinal tract, the enteroendocrine cells, trigger the release of gut hormones that provide important local and central feedback signals to regulate nutrient utilisation and feeding behaviour. The evidence for nutrient-stimulated secretion of two of the most studied gut hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), along with the known cellular mechanisms in enteroendocrine cells recruited by nutrients, will be the focus of this review. The mechanisms involved range from electrogenic transporters, ion channel modulation and nutrient-activated G-protein coupled receptors that converge on the release machinery controlling hormone secretion. Elucidation of these mechanisms will provide much needed insight into postprandial physiology and identify tractable dietary approaches to potentially manage nutrition and satiety by altering the secreted gut hormone profile.
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8
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Kuhre RE, Deacon CF, Holst JJ, Petersen N. What Is an L-Cell and How Do We Study the Secretory Mechanisms of the L-Cell? Front Endocrinol (Lausanne) 2021; 12:694284. [PMID: 34168620 PMCID: PMC8218725 DOI: 10.3389/fendo.2021.694284] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Synthetic glucagon-like peptide-1 (GLP-1) analogues are effective anti-obesity and anti-diabetes drugs. The beneficial actions of GLP-1 go far beyond insulin secretion and appetite, and include cardiovascular benefits and possibly also beneficial effects in neurodegenerative diseases. Considerable reserves of GLP-1 are stored in intestinal endocrine cells that potentially might be mobilized by pharmacological means to improve the body's metabolic state. In recognition of this, the interest in understanding basic L-cell physiology and the mechanisms controlling GLP-1 secretion, has increased considerably. With a view to home in on what an L-cell is, we here present an overview of available data on L-cell development, L-cell peptide expression profiles, peptide production and secretory patterns of L-cells from different parts of the gut. We conclude that L-cells differ markedly depending on their anatomical location, and that the traditional definition of L-cells as a homogeneous population of cells that only produce GLP-1, GLP-2, glicentin and oxyntomodulin is no longer tenable. We suggest to sub-classify L-cells based on their differential peptide contents as well as their differential expression of nutrient sensors, which ultimately determine the secretory responses to different stimuli. A second purpose of this review is to describe and discuss the most frequently used experimental models for functional L-cell studies, highlighting their benefits and limitations. We conclude that no experimental model is perfect and that a comprehensive understanding must be built on results from a combination of models.
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Affiliation(s)
- Rune E. Kuhre
- Department of Obesity Pharmacology, Novo Nordisk, Måløv, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Rune E. Kuhre, ;
| | - Carolyn F. Deacon
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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Tough IR, Schwartz TW, Cox HM. Synthetic G protein-coupled bile acid receptor agonists and bile acids act via basolateral receptors in ileal and colonic mucosa. Neurogastroenterol Motil 2020; 32:e13943. [PMID: 32656959 DOI: 10.1111/nmo.13943] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/29/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND The G protein-coupled bile acid (BA) receptor, GPBA (previously named TGR5), mediates BA gastrointestinal (GI) activities. Our aim was to elucidate the mucosal and motility responses to selective GPBA agonists compared with conjugated BA (eg, taurodeoxycholate, TDCA) in mouse and human colon. METHODS Ion transport responses to GPBA agonists or BAs were measured in mucosal preparations with intact submucous innervation, from C57Bl/6, PYY-/-, or GPBA-/- mice and compared with GPBA signaling in human colon. We also investigated the mechanisms underlying GPBA agonism in mucosae and on natural fecal pellet propulsion. KEY RESULTS GPBA agonist Merck V stimulated basolateral responses involving peptide YY (PYY), cholinergic, and 5-HT mechanisms in colonic mucosa. The PYY-mediated GPBA signal was glucose-sensitive. Luminal TDCA crossed the epithelial lining via the apical sodium-dependent BA transporter (ASBT) and its inhibitor, GSK2330672 significantly reduced luminal, but not basolateral TDCA activity. Merck V also slowed natural fecal pellet progression in wild-type and PYY-/- colons but not in GPBA-/- colon, while TDCA increased motility in wild-type colon. The antimotile GPBA effect was reversed by blockade of glucagon-like peptide 1 (GLP-1) receptors or nitric oxide synthase, indicating involvement of GLP-1 and nitric oxide. CONCLUSIONS & INFERENCES We conclude that several different targets within the lamina propria express GPBA, including L cells (that release PYY and GLP-1), enterochromaffin cells and neurons (that release 5-HT), and other enteric neurons. Furthermore, luminal-conjugated BAs require transport across the epithelium via ASBT in order to activate basolateral GPBA.
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Affiliation(s)
- Iain R Tough
- King's College London, Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, London, UK
| | - Thue W Schwartz
- Novo Nordisk Foundation Centre for Basic Metabolic Research, Section for Metabolic Receptology and Enteroendocrinology, University of Copenhagen, Copenhagen, Denmark
| | - Helen M Cox
- King's College London, Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, London, UK
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Goldspink DA, Reimann F, Gribble FM. Models and Tools for Studying Enteroendocrine Cells. Endocrinology 2018; 159:3874-3884. [PMID: 30239642 PMCID: PMC6215081 DOI: 10.1210/en.2018-00672] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/05/2018] [Indexed: 12/14/2022]
Abstract
Gut hormones produced by gastrointestinal enteroendocrine cells modulate key physiological processes including glucose homeostasis and food intake, making them potential therapeutic candidates to treat obesity and diabetes. Understanding the function of enteroendocrine cells and the molecular mechanisms driving hormone production is a key step toward mobilizing endogenous hormone reserves in the gut as a therapeutic strategy. In this review, we will discuss the variety of ex vivo and in vitro model systems driving this research and their contributions to our current understanding of nutrient-sensing mechanisms in enteroendocrine cells.
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Affiliation(s)
- Deborah A Goldspink
- Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom
| | - Frank Reimann
- Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom
| | - Fiona M Gribble
- Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom
- Correspondence: Fiona M. Gribble, DPhil, BM, BCh, Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, United Kingdom. E-mail:
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11
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Tough IR, Forbes S, Cox HM. Signaling of free fatty acid receptors 2 and 3 differs in colonic mucosa following selective agonism or coagonism by luminal propionate. Neurogastroenterol Motil 2018; 30:e13454. [PMID: 30136343 PMCID: PMC6282569 DOI: 10.1111/nmo.13454] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/20/2018] [Accepted: 07/25/2018] [Indexed: 01/05/2023]
Abstract
BACKGROUND Propionate exhibits affinity for free fatty acid receptor 2 (FFA2, formerly GPR43) and FFA3 (GPR41). These two G protein-coupled receptors (GPCRs) are expressed by enteroendocrine L cells that contain anorectic peptide YY (PYY) and glucagon-like peptide 1 (GLP-1), while FFA3 is also expressed by enteric neurons. Few studies have investigated the individual roles of FFA2 and FFA3 in propionate's gastrointestinal (GI) effects. Here, we compared FFA2, FFA3, and propionate mucosal responses utilizing selective ligands including an FFA3 antagonist, in mouse and human colonic mucosa. METHODS Vectorial ion transport was measured in native colonic preparations from normal mouse and human colon with intact submucosal innervation. Endogenous fecal pellet propulsion was monitored in colons isolated from wild-type (WT) and PYY-/- mice. KEY RESULTS FFA2 and FFA3 signaling differed significantly. FFA2 agonism involved endogenous L cell-derived PYY and was glucose dependent, while FFA3 agonism was independent of PYY and glucose, but required submucosal enteric neurons for activity. Tonic FFA3 activity was observed in mouse and human colon mucosa. Apical propionate responses were a combination of FFA2-PYY mediation and FFA3 neuronal GLP-1- and CGRP-dependent signaling in mouse ascending colon mucosa. Propionate also slowed WT and PYY-/- colonic transit, and this effect was blocked by a GLP-1 receptor antagonist. CONCLUSIONS & INFERENCES We conclude that luminal propionate costimulates FFA2 and FFA3 pathways, reducing anion secretion and slowing colonic motility; FFA2 via PYY mediation and FFA3 signaling by activation of enteric sensory neurons.
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Affiliation(s)
- Iain R. Tough
- King's College LondonWolfson Centre for Age‐Related Diseases, Institute of Psychiatry, Psychology & NeuroscienceLondonUK
| | - Sarah Forbes
- King's College LondonWolfson Centre for Age‐Related Diseases, Institute of Psychiatry, Psychology & NeuroscienceLondonUK
| | - Helen M. Cox
- King's College LondonWolfson Centre for Age‐Related Diseases, Institute of Psychiatry, Psychology & NeuroscienceLondonUK
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12
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Acar I, Cetinkaya A, Lay I, Ileri-Gurel E. The role of calcium sensing receptors in GLP-1 and PYY secretion after acute intraduodenal administration of L-Tryptophan in rats. Nutr Neurosci 2018; 23:481-489. [PMID: 30222528 DOI: 10.1080/1028415x.2018.1521906] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Objectives: The calcium-sensing receptor (CaSR), the major sensor of extracellular Ca2+, is expressed in various tissues, including the gastrointestinal tract. Although the essential ligand of CaSR is calcium, its activity can be regulated by aromatic L-amino acids. The expression of CaSR on enteroendocrine cells suggests that CaSR functions as a physiological amino acid sensor for gut hormone release. Here, we investigated the effects of L-tryptophan (L-Trp) on rat glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and insulin secretion, and the role of CaSR in this mechanism in vivo.Methods: The effects of intraduodenal L-Trp on GLP-1, PYY, and insulin secretion were investigated. A CaSR antagonist, NPS 2143, was administered to determine whether CaSR plays a role in L-Trp-mediated gut hormone release. Male Wistar rats were divided into L-Trp, L-Trp+NPS 2143, and L-Trp+vehicle groups. Blood samples were collected, before and after the intraduodenal infusions, for determining plasma glucose, L-Trp, insulin, GLP-1, and PYY levels.Results: Our study showed a significant increase in plasma GLP-1 and insulin levels, but not plasma PYY and glucose levels, following the acute intraduodenal administration of L-Trp. We demonstrated that CaSR plays a role in L-Trp-mediated GLP-1 secretion due to attenuation of GLP-1 release with the CaSR antagonist NPS 2143.Discussion: We demonstrated that GLP-1, but not PYY, secretion following intraduodenal L-Trp administration was mediated through calcium-sensing receptors. This mechanism underlying protein sensing in the gastrointestinal system may be important for the development of new therapeutic strategies without side effects for obesity and diabetes.
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Affiliation(s)
- Ipek Acar
- Physiology Department, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Alper Cetinkaya
- Laboratory Animals Research and Application Center, Hacettepe University, Ankara, Turkey
| | - Incilay Lay
- Medical Biochemistry Department, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Esin Ileri-Gurel
- Physiology Department, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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13
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Tough IR, Forbes S, Herzog H, Jones RM, Schwartz TW, Cox HM. Bidirectional GPR119 Agonism Requires Peptide YY and Glucose for Activity in Mouse and Human Colon Mucosa. Endocrinology 2018; 159:1704-1717. [PMID: 29471473 PMCID: PMC5972582 DOI: 10.1210/en.2017-03172] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 02/05/2018] [Indexed: 12/22/2022]
Abstract
The lipid sensor G protein-coupled receptor 119 (GPR119) is highly expressed by enteroendocrine L-cells and pancreatic β-cells that release the hormones, peptide YY (PYY) and glucagonlike peptide 1, and insulin, respectively. Endogenous oleoylethanolamide (OEA) and the dietary metabolite, 2-monoacylglycerol (2-OG), can each activate GPR119. Here, we compared mucosal responses with selective, synthetic GPR119 agonists (AR440006 and AR231453) and the lipids, OEA, 2-OG, and N-oleoyldopamine (OLDA), monitoring epithelial ion transport as a readout for L-cell activity in native mouse and human gastrointestinal (GI) mucosae. We also assessed GPR119 modulation of colonic motility in wild-type (WT), GPR119-deficient (GPR119-/-), and PYY-deficient (PYY-/-) mice. The water-soluble GPR119 agonist, AR440006 (that cannot traverse epithelial tight junctions), elicited responses, when added apically or basolaterally in mouse and human colonic mucosae. In both species, GPR119 responses were PYY, Y1 receptor mediated, and glucose dependent. AR440006 efficacy matched the GI distribution of L-cells in WT tissues but was absent from GPR119-/- tissue. OEA and 2-OG responses were significantly reduced in the GPR119-/- colon, but OLDA responses were unchanged. Alternative L-cell activation via free fatty acid receptors 1, 3, and 4 and the G protein-coupled bile acid receptor TGR5 or by the melanocortin 4 receptor, was unchanged in GPR119-/- tissues. The GPR119 agonist slowed transit in WT but not the PYY-/- colon in vitro. AR440006 (intraperitoneally) slowed WT colonic and upper-GI transit significantly in vivo. These data indicate that luminal or blood-borne GPR119 agonism can stimulate L-cell PYY release with paracrine consequences and slower motility. We suggest that this glucose-dependent L-cell response to a gut-restricted GPR119 stimulus has potential therapeutic advantage in modulating insulinotropic signaling with reduced risk of hypoglycemia.
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Affiliation(s)
- Iain R Tough
- King’s College London, Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom
| | - Sarah Forbes
- King’s College London, Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom
| | - Herbert Herzog
- Garvan Institute of Medical Research, Darlinghurst New South Wales, Sydney, Australia
| | - Robert M Jones
- Department of Medicinal Chemistry, Arena Pharmaceuticals, San Diego, California
| | - Thue W Schwartz
- Section for Metabolic Receptology and Enteroendocrinology, Novo Nordisk Foundation Centre for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Helen M Cox
- King’s College London, Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom
- Correspondence: Helen M. Cox, PhD, Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London SE1 1UL, United Kingdom. E-mail:
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14
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Parvaresh Rizi E, Loh TP, Baig S, Chhay V, Huang S, Caleb Quek J, Tai ES, Toh SA, Khoo CM. A high carbohydrate, but not fat or protein meal attenuates postprandial ghrelin, PYY and GLP-1 responses in Chinese men. PLoS One 2018; 13:e0191609. [PMID: 29385178 PMCID: PMC5792004 DOI: 10.1371/journal.pone.0191609] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/08/2018] [Indexed: 12/22/2022] Open
Abstract
It is known that the macronutrient content of a meal has different impacts on the postprandial satiety and appetite hormonal responses. Whether obesity interacts with such nutrient-dependent responses is not well characterized. We examined the postprandial appetite and satiety hormonal responses after a high-protein (HP), high-carbohydrate (HC), or high-fat (HF) mixed meal. This was a randomized cross-over study of 9 lean insulin-sensitive (mean±SEM HOMA-IR 0.83±0.10) and 9 obese insulin-resistant (HOMA-IR 4.34±0.41) young (age 21–40 years), normoglycaemic Chinese men. We measured fasting and postprandial plasma concentration of glucose, insulin, active glucagon-like peptide-1 (GLP-1), total peptide-YY (PYY), and acyl-ghrelin in response to HP, HF, or HC meals. Overall postprandial plasma insulin response was more robust in the lean compared to obese subjects. The postprandial GLP-1 response after HF or HP meal was higher than HC meal in both lean and obese subjects. In obese subjects, HF meal induced higher response in postprandial PYY compared to HC meal. HP and HF meals also suppressed ghrelin greater compared to HC meal in the obese than lean subjects. In conclusion, a high-protein or high-fat meal induces a more favorable postprandial satiety and appetite hormonal response than a high-carbohydrate meal in obese insulin-resistant subjects.
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Affiliation(s)
- Ehsan Parvaresh Rizi
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Medicine, National University Health System, Singapore
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Health System, Singapore
| | - Sonia Baig
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Vanna Chhay
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Shiqi Huang
- Food Science and Technology Program, Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
| | - Jonathan Caleb Quek
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - E. Shyong Tai
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Medicine, National University Health System, Singapore
- Duke-National University of Singapore Medical School, Singapore
| | - Sue-Anne Toh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Medicine, National University Health System, Singapore
- Duke-National University of Singapore Medical School, Singapore
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Chin Meng Khoo
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Medicine, National University Health System, Singapore
- * E-mail:
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15
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Brownlee IA, Gill S, Wilcox MD, Pearson JP, Chater PI. Starch digestion in the upper gastrointestinal tract of humans. STARCH-STARKE 2018. [DOI: 10.1002/star.201700111] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Iain A. Brownlee
- Human Nutrition Research CentreNewcastle Research and Innovation InstituteNewcastle UniversitySingaporeSingapore
| | - Saloni Gill
- Human Nutrition Research CentreNewcastle Research and Innovation InstituteNewcastle UniversitySingaporeSingapore
| | - Matt D. Wilcox
- Institute for Cell and Molecular BiosciencesThe Medical SchoolNewcastle UniversityNewcastle Upon TyneUnited Kingdom
| | - Jeff P. Pearson
- Institute for Cell and Molecular BiosciencesThe Medical SchoolNewcastle UniversityNewcastle Upon TyneUnited Kingdom
| | - Peter I. Chater
- Institute for Cell and Molecular BiosciencesThe Medical SchoolNewcastle UniversityNewcastle Upon TyneUnited Kingdom
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16
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Tough IR, Moodaley R, Cox HM. Mucosal glucagon-like peptide 1 (GLP-1) responses are mediated by calcitonin gene-related peptide (CGRP) in the mouse colon and both peptide responses are area-specific. Neurogastroenterol Motil 2018; 30. [PMID: 28695626 DOI: 10.1111/nmo.13149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/05/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND Glucagon-like peptide (GLP)-1 is an incretin hormone and its mimetics are proven antidiabetic and antiobesity drugs. GLP-1 exerts antimotility and mucosal proliferative activities but its epithelial ion transport effects are uncharacterized and these may contribute to the gastrointestinal (GI) disturbance, i.e., diarrhea experienced with some GLP-1 mimetics. Our aim was to establish GLP-1 agonist mechanisms and identify potential mucosal mediator(s) in the colonic tissue from C57BL/6J mice. METHODS A tissue survey of GLP-1 responses (using exendin 4, Ex4) and α-calcitonin gene-related peptide (αCGRP) was undertaken, dividing the mouse colon into eight adjacent mucosal-submucosal preparations. Each preparation was voltage-clamped and changes in short-circuit current (Isc) measured. The involvement of submucosal neurons in GLP-1 agonism was tested using Ex(9-39) and tetrodotoxin (TTX), and CGRP receptors were blocked with BIBN4094. KEY RESULTS Ex4 responses along the length of the colon were inhibited by the GLP-1 antagonist, Ex(9-39) or TTX, indicating neural mediation in all colonic regions. In the ascending colon, Ex4 increased Isc levels that were abolished by 10 nM BIBN4096, while in the descending colon it reduced Isc levels that were again BIBN4096-sensitive, but at 1 μM. The latter αCGRP response was dependent on epithelial Cl- conductance and Na+ /K+ -ATPase, and was partially (~25%) peptide YY-mediated, but was not nitrergic, somatostatin sst2 , or α2 -adrenoceptor-mediated. CONCLUSIONS AND INFERENCES GLP-1 modulates epithelial ion transport indirectly by activating CGRP-containing submucosal enteric neurons in the mouse colon. This GLP-1-CGRP response was area-specific and could potentially contribute to the diarrheal side effect of certain GLP-1R therapeutics.
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Affiliation(s)
- I R Tough
- Wolfson Centre for Age-Related Diseases, King's College London, IoPPN, Guy's Campus, London, UK
| | - R Moodaley
- Wolfson Centre for Age-Related Diseases, King's College London, IoPPN, Guy's Campus, London, UK
| | - H M Cox
- Wolfson Centre for Age-Related Diseases, King's College London, IoPPN, Guy's Campus, London, UK
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17
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Targeting gastrointestinal nutrient sensing mechanisms to treat obesity. Curr Opin Pharmacol 2017; 37:16-23. [DOI: 10.1016/j.coph.2017.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/20/2017] [Indexed: 12/15/2022]
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18
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Moodaley R, Smith DM, Tough IR, Schindler M, Cox HM. Agonism of free fatty acid receptors 1 and 4 generates peptide YY-mediated inhibitory responses in mouse colon. Br J Pharmacol 2017; 174:4508-4522. [PMID: 28971469 DOI: 10.1111/bph.14054] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 09/16/2017] [Accepted: 09/20/2017] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Free fatty acid receptors FFA1 and FFA4 are located on enteroendocrine L cells with the highest gastrointestinal (GI) expression in descending colon. Their activation causes the release of glucagon-like peptide 1 and peptide YY (PYY) from L cells. Additionally, FFA1 agonism releases insulin from pancreatic β cells. As these receptors are modulators of nutrient-stimulated glucose regulation, the aim of this study was to compare the pharmacology of commercially available agonists (TUG424, TUG891, GW9508) with proven selective agonists (JTT, TAK-875, AZ423, Metabolex-36) in mice. EXPERIMENTAL APPROACH Mouse mucosa was mounted in Ussing chambers, voltage-clamped and the resultant short-circuit current (Isc ) was recorded continuously. Pretreatments included antagonists of FFA1, Y1 or Y2 receptors. Glucose sensitivity was investigated by mannitol replacement apically, and colonic and upper GI transit was assessed in vitro and in vivo. KEY RESULTS FFA1 and FFA4 agonism required glucose and reduced Isc in a PYY-Y1 receptor-dependent manner. The novel compounds were more potent than GW9508. The FFA1 antagonists (GW1100 and ANT825) blocked FFA1 activity only and revealed FFA1 tonic activity. The FFA4 agonist, Metabolex-36, slowed colonic transit in vitro but increased small intestinal transit in vivo. CONCLUSIONS AND IMPLICATIONS The selective FFA1 and FFA4 agonists were more potent at reducing Isc than GW9508, a dual FFA1 and FFA4 agonist. A paracrine epithelial mechanism involving PYY-stimulated Y1 receptors mediated their responses, which were glucose sensitive, potentially limiting hypoglycaemia. ANT825 revealed tonic activity and the possibility of endogenous FFA1 ligands causing PYY release. Finally, FFA4 agonism induced regional differences in transit.
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Affiliation(s)
- Runisha Moodaley
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - David M Smith
- Discovery Sciences, Innovative Medicines & Early Development Biotech Unit, AstraZeneca, Cambridge, UK
| | - Iain R Tough
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Marcus Schindler
- AstraZeneca Mölndal, Innovative Medicines & Early Development, Cardiovascular & Metabolic Diseases iMed, Mölndal, Sweden
| | - Helen M Cox
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
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Sparks SM, Spearing PK, Diaz CJ, Cowan DJ, Jayawickreme C, Chen G, Rimele TJ, Generaux C, Harston LT, Roller SG. Identification of potent, nonabsorbable agonists of the calcium-sensing receptor for GI-specific administration. Bioorg Med Chem Lett 2017; 27:4673-4677. [PMID: 28916340 DOI: 10.1016/j.bmcl.2017.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/25/2017] [Accepted: 09/06/2017] [Indexed: 12/14/2022]
Abstract
Modulation of gastrointestinal nutrient sensing pathways provides a promising a new approach for the treatment of metabolic diseases including diabetes and obesity. The calcium-sensing receptor has been identified as a key receptor involved in mineral and amino acid nutrient sensing and thus is an attractive target for modulation in the intestine. Herein we describe the optimization of gastrointestinally restricted calcium-sensing receptor agonists starting from a 3-aminopyrrolidine-containing template leading to the identification of GI-restricted agonist 19 (GSK3004774).
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Affiliation(s)
- Steven M Sparks
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States.
| | - Paul K Spearing
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Caroline J Diaz
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - David J Cowan
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Channa Jayawickreme
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Grace Chen
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Thomas J Rimele
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Claudia Generaux
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Lindsey T Harston
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
| | - Shane G Roller
- Enteroendocrine Discovery Performance Unit and Platform Technologies and Science, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, United States
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Muscogiuri G, Balercia G, Barrea L, Cignarelli A, Giorgino F, Holst JJ, Laudisio D, Orio F, Tirabassi G, Colao A. Gut: A key player in the pathogenesis of type 2 diabetes? Crit Rev Food Sci Nutr 2017; 58:1294-1309. [PMID: 27892685 DOI: 10.1080/10408398.2016.1252712] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The gut regulates glucose and energy homeostasis; thus, the presence of ingested nutrients into the gut activates sensing mechanisms that affect both glucose homeostasis and regulate food intake. Increasing evidence suggest that gut may also play a key role in the pathogenesis of type 2 diabetes which may be related to both the intestinal microbiological profile and patterns of gut hormones secretion. Intestinal microbiota includes trillions of microorganisms but its composition and function may be adversely affected in type 2 diabetes. The intestinal microbiota may be responsible of the secretion of molecules that may impair insulin secretion/action. At the same time, intestinal milieu regulates the secretion of hormones such as GLP-1, GIP, ghrelin, gastrin, somatostatin, CCK, serotonin, peptide YY, GLP-2, all of which importantly influence metabolism in general and in particular glucose metabolism. Thus, the aim of this paper is to review the current evidence on the role of the gut in the pathogenesis of type 2 diabetes, taking into account both hormonal and microbiological aspects.
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Affiliation(s)
| | - Giancarlo Balercia
- b Division of Endocrinology, Department of Clinical and Molecular Sciences , Umberto I Hospital, Polytechnic University of Marche , Ancona , Italy
| | | | - Angelo Cignarelli
- c Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases , University of Bari Aldo Moro , Bari , Italy
| | - Francesco Giorgino
- c Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases , University of Bari Aldo Moro , Bari , Italy
| | - Jens J Holst
- d NNF Center for Basic Metabolic Research and Department of Biomedical Sciences , Panum Institute, University of Copenhagen, Copenhagen , Denmark
| | | | - Francesco Orio
- e Endocrinology, Department of Sports Science and Wellness , "Parthenope" University Naples , Naples , Italy
| | - Giacomo Tirabassi
- b Division of Endocrinology, Department of Clinical and Molecular Sciences , Umberto I Hospital, Polytechnic University of Marche , Ancona , Italy
| | - Annamaria Colao
- f Department of Clinical Medicine and Surgery , "Federico II" University of Naples , Naples , Italy
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21
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Fatty acid and mineral receptors as drug targets for gastrointestinal disorders. Future Med Chem 2017; 9:315-334. [DOI: 10.4155/fmc-2016-0205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nutrient-sensing receptors, including fatty acid receptors (FFA1–FFA4), Ca2+-sensing receptors and Zn2+-sensing receptors, are involved in several biological processes. These receptors are abundantly expressed in the GI tract, where they have been shown to play crucial roles in regulating GI function. This review provides an overview of the GI functions of fatty acid and mineral receptors, including the regulation of gastric and enteroendocrine functions, GI motility, ion transport and cell growth. Recently, several lines of evidence have implicated these receptors as promising therapeutic targets for the treatment of GI disorders, for example, inflammatory bowel disease, colorectal cancer, metabolic syndrome and diarrheal diseases. A future perspective on drug discovery research targeting these receptors is discussed.
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Bodnaruc AM, Prud’homme D, Blanchet R, Giroux I. Nutritional modulation of endogenous glucagon-like peptide-1 secretion: a review. Nutr Metab (Lond) 2016; 13:92. [PMID: 27990172 PMCID: PMC5148911 DOI: 10.1186/s12986-016-0153-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/30/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The positive influences of glucagon-like peptide-1 (GLP-1) on blood glucose homeostasis, appetite sensations, and food intake provide a strong rationale for its therapeutic potential in the nutritional management of obesity and type 2 diabetes. AIM To summarize GLP-1 physiology and the nutritional modulation of its secretion in the context of obesity and type 2 diabetes management. FINDINGS GLP-1 is mainly synthesized and secreted by enteroendocrine L-cells of the gastrointestinal tract. Its secretion is partly mediated by the direct nutrient sensing by G-protein coupled receptors which specifically bind to monosaccharides, peptides and amino-acids, monounsaturated and polyunsaturated fatty acids as well as to short chain fatty acids. Foods rich in these nutrients, such as high-fiber grain products, nuts, avocados and eggs also seem to influence GLP-1 secretion and may thus promote associated beneficial outcomes in healthy individuals as well as individuals with type 2 diabetes or with other metabolic disturbances. CONCLUSION The stimulation of endogenous GLP-1 secretion by manipulating the composition of the diet may be a relevant strategy for obesity and type 2 diabetes management. A better understanding of the dose-dependent effects as well as the synergistic effects of nutrients and whole foods is needed in order to develop recommendations to appropriately modify the diet to enhance GLP-1 beneficial effects.
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Affiliation(s)
- Alexandra M. Bodnaruc
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, 35, University Private, Room 050F, K1N 6N5 Ottawa, ON Canada
- Institut de Recherche de l’Hôpital Montfort, Institut du savoir, 745 Montreal Road, Room 202, K1K 0T2 Ottawa, ON Canada
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, 35 University Private, Room 050F, K1N 6N5 Ottawa, ON Canada
| | - Denis Prud’homme
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, 35, University Private, Room 050F, K1N 6N5 Ottawa, ON Canada
- Institut de Recherche de l’Hôpital Montfort, Institut du savoir, 745 Montreal Road, Room 202, K1K 0T2 Ottawa, ON Canada
| | - Rosanne Blanchet
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, 35 University Private, Room 050F, K1N 6N5 Ottawa, ON Canada
| | - Isabelle Giroux
- Institut de Recherche de l’Hôpital Montfort, Institut du savoir, 745 Montreal Road, Room 202, K1K 0T2 Ottawa, ON Canada
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, 25 University Private, Room 116, K1N 6N5 Ottawa, ON Canada
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Cox HM. Neuroendocrine peptide mechanisms controlling intestinal epithelial function. Curr Opin Pharmacol 2016; 31:50-56. [PMID: 27597736 DOI: 10.1016/j.coph.2016.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/20/2016] [Accepted: 08/12/2016] [Indexed: 01/01/2023]
Abstract
Enteroendocrine cells (EECs) contain different combinations of hormones, which are released following stimulation of nutrient receptors that are selectively expressed by these cells. This chemosensation varies according to the intestinal area and species of interest, and responses to meals are rapidly modified following bariatric surgery. Such surgically-induced gastrointestinal (GI) changes highlight considerable enteroplasticity, however our understanding of even the acute physiological control and consequences of neuroendocrine peptide release is still under-developed. This review focuses on recent advances in nutrient G protein-coupled receptor (GPCR)-chemosensation in L cells, the patterns of peptide release and consequent changes in GI function. A clearer resolution of these mucosal mechanisms will shed light on potential receptor-target combinations that could provide less-invasive anti-diabesity strategies in future.
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Affiliation(s)
- Helen M Cox
- Wolfson Centre for Age-Related Diseases, IoPPN, King's College London, London SE1 1UL, UK.
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24
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Alamshah A, McGavigan AK, Spreckley E, Kinsey-Jones JS, Amin A, Tough IR, O'Hara HC, Moolla A, Banks K, France R, Hyberg G, Norton M, Cheong W, Lehmann A, Bloom SR, Cox HM, Murphy KG. L-arginine promotes gut hormone release and reduces food intake in rodents. Diabetes Obes Metab 2016; 18:508-18. [PMID: 26863991 PMCID: PMC4982043 DOI: 10.1111/dom.12644] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/31/2016] [Accepted: 02/07/2016] [Indexed: 12/14/2022]
Abstract
AIMS To investigate the anorectic effect of L-arginine (L-Arg) in rodents. METHODS We investigated the effects of L-Arg on food intake, and the role of the anorectic gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), the G-protein-coupled receptor family C group 6 member A (GPRC6A) and the vagus nerve in mediating these effects in rodents. RESULTS Oral gavage of L-Arg reduced food intake in rodents, and chronically reduced cumulative food intake in diet-induced obese mice. Lack of the GPRC6A in mice and subdiaphragmatic vagal deafferentation in rats did not influence these anorectic effects. L-Arg stimulated GLP-1 and PYY release in vitro and in vivo. Pharmacological blockade of GLP-1 and PYY receptors did not influence the anorectic effect of L-Arg. L-Arg-mediated PYY release modulated net ion transport across the gut mucosa. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of L-Arg suppressed food intake in rats. CONCLUSIONS L-Arg reduced food intake and stimulated gut hormone release in rodents. The anorectic effect of L-Arg is unlikely to be mediated by GLP-1 and PYY, does not require GPRC6A signalling and is not mediated via the vagus. I.c.v. and i.p. administration of L-Arg suppressed food intake in rats, suggesting that L-Arg may act on the brain to influence food intake. Further work is required to determine the mechanisms by which L-Arg suppresses food intake and its utility in the treatment of obesity.
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MESH Headings
- Animals
- Appetite Depressants/administration & dosage
- Appetite Depressants/adverse effects
- Appetite Depressants/pharmacology
- Appetite Depressants/therapeutic use
- Arginine/administration & dosage
- Arginine/adverse effects
- Arginine/therapeutic use
- Cells, Cultured
- Dietary Supplements/adverse effects
- Energy Intake/drug effects
- Energy Metabolism/drug effects
- Gastrointestinal Agents/administration & dosage
- Gastrointestinal Agents/adverse effects
- Gastrointestinal Agents/pharmacology
- Gastrointestinal Agents/therapeutic use
- Glucagon-Like Peptide 1/agonists
- Glucagon-Like Peptide 1/blood
- Glucagon-Like Peptide 1/metabolism
- In Vitro Techniques
- Injections, Intraperitoneal
- Injections, Intraventricular
- Intestinal Mucosa/cytology
- Intestinal Mucosa/drug effects
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/pathology
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Obesity/diet therapy
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- Peptide YY/agonists
- Peptide YY/blood
- Peptide YY/metabolism
- Random Allocation
- Rats, Wistar
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Weight Loss/drug effects
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Affiliation(s)
- A Alamshah
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A K McGavigan
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - E Spreckley
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - J S Kinsey-Jones
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A Amin
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - I R Tough
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - H C O'Hara
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A Moolla
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - K Banks
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - R France
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - G Hyberg
- AstraZeneca R&D, Mölndal, Sweden
| | - M Norton
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - W Cheong
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - A Lehmann
- AstraZeneca R&D, Mölndal, Sweden
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - S R Bloom
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
| | - H M Cox
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - K G Murphy
- Section of Endocrinology and Investigative Medicine, Department of Medicine, Imperial College London, London, UK
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25
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Pais R, Rievaj J, Meek C, De Costa G, Jayamaha S, Alexander RT, Reimann F, Gribble F. Role of enteroendocrine L-cells in arginine vasopressin-mediated inhibition of colonic anion secretion. J Physiol 2016; 594:4865-78. [PMID: 27037495 PMCID: PMC5009784 DOI: 10.1113/jp272053] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/20/2016] [Indexed: 12/17/2022] Open
Abstract
Key points Arginine vasopressin (AVP) stimulates the release of enteroendocrine L‐cell derived hormones glucagon‐like peptide‐1 (GLP‐1) and peptide YY (PYY) in vitro from mouse and human colons. This is mediated by the AVP receptor 1B, which is highly enriched in colonic L‐cells and linked to the elevation of L‐cell calcium and cAMP concentrations. By means of Ussing chambers, we show that AVP reduced colonic anion secretion, although this was blocked by a specific neuropeptide Y receptor Y1 receptor antagonist, suggesting that L‐cell‐released PYY acts locally on the epithelium to modulate fluid balance. In human serum samples, PYY concentrations were higher in samples with raised osmolality and copeptin (surrogate marker for AVP). These findings describe, for the first time, the role of L‐cells in AVP regulated intestinal fluid secretion, potentially linking together hormonal control of blood volume and blood glucose levels, and thus adding to our understanding of the complex pathways involved in the gut hormonal response to different stimuli.
Abstract Arginine vasopressin (AVP) regulates fluid balance and blood pressure via AVP receptor (AVPR)2 in the kidney and AVP receptor 1A in vascular smooth muscle. Its role in intestinal function has received less attention. We hypothesized that enteroendocrine L‐cells producing glucagon‐like peptide 1 (GLP‐1) and peptide YY (PYY) may be a target of AVP and contribute to the control of fluid balance. Avpr1b expression was assessed by quantitative RT‐PCR on flourescence‐activated cell sorting‐isolated L‐ and control cells and was enriched in colonic L‐cells. AVP stimulated GLP‐1 and PYY release from primary cultured murine and human colonic cells and was associated with elevated calcium and cAMP concentrations in L‐cells as measured in cultures from GLU‐Cre/ROSA26‐GCaMP3 and GLU‐Epac2camps mice. An antagonist of AVPR1B reduced AVP‐triggered hormone secretion from murine and human cells. In Ussing chambers, basolaterally applied AVP reduced colonic anion secretion and this effect was blocked by a specific neuropeptide Y receptor Y1 (NPY1R) antagonist. In human serum, PYY concentrations were higher in samples with raised osmolality or copeptin (a surrogate marker for AVP). In conclusion, we propose that AVP activates L‐cell AVPR1B, causing GLP‐1 and PYY secretion. PYY in turn reduces colonic anion secretion via epithelial NPY1R. Our data suggest L‐cells are active players in the hypothalamic control of intestinal fluid homeostasis, providing a potential link between the regulation of blood volume/pressure/osmolality and blood glucose. Arginine vasopressin (AVP) stimulates the release of enteroendocrine L‐cell derived hormones glucagon‐like peptide‐1 (GLP‐1) and peptide YY (PYY) in vitro from mouse and human colons. This is mediated by the AVP receptor 1B, which is highly enriched in colonic L‐cells and linked to the elevation of L‐cell calcium and cAMP concentrations. By means of Ussing chambers, we show that AVP reduced colonic anion secretion, although this was blocked by a specific neuropeptide Y receptor Y1 receptor antagonist, suggesting that L‐cell‐released PYY acts locally on the epithelium to modulate fluid balance. In human serum samples, PYY concentrations were higher in samples with raised osmolality and copeptin (surrogate marker for AVP). These findings describe, for the first time, the role of L‐cells in AVP regulated intestinal fluid secretion, potentially linking together hormonal control of blood volume and blood glucose levels, and thus adding to our understanding of the complex pathways involved in the gut hormonal response to different stimuli.
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Affiliation(s)
- Ramona Pais
- The Wellcome Trust - MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Juraj Rievaj
- The Wellcome Trust - MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Claire Meek
- The Wellcome Trust - MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Gayan De Costa
- Department of Clinical Biochemistry, Cambridge University Hospitals, Addenbrooke's Hospital, Cambridge, UK
| | - Samanthie Jayamaha
- Department of Clinical Biochemistry, Cambridge University Hospitals, Addenbrooke's Hospital, Cambridge, UK
| | - R Todd Alexander
- Departments of Paediatrics & Physiology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Frank Reimann
- The Wellcome Trust - MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Fiona Gribble
- The Wellcome Trust - MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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26
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Liu J, Yu K, Zhu W. Amino acid sensing in the gut and its mediation in gut-brain signal transduction. ACTA ACUST UNITED AC 2016; 2:69-73. [PMID: 29767064 PMCID: PMC5940996 DOI: 10.1016/j.aninu.2016.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 11/28/2022]
Abstract
Animal gastrointestinal tract is not only a digestive organ, but also a nutrient sensing organ which detects luminal nutrient and thus can regulate food intake. There are many amino acid sensing receptors and transporters in the gut. Amino acids sensing by these receptors and transporters can stimulate the intestinal endocrine cells to release a variety of gut hormones. These hormones trigger a series of physiological effects via the nerve system. This review summarized the recent advance on the amino acid sensing receptors and transporters in the gastrointestinal tract, the gut hormones released from the intestinal endocrine cells and the hormones-induced signal transduction between the gut and brain. A better understanding of these processes may help to gain further insight into the specific role of amino acids in digestion and provide guidelines in developing strategy for the better use of amino acids in the diet.
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Affiliation(s)
- Jing Liu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Kaifan Yu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
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27
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Brighton CA, Rievaj J, Kuhre RE, Glass LL, Schoonjans K, Holst JJ, Gribble FM, Reimann F. Bile Acids Trigger GLP-1 Release Predominantly by Accessing Basolaterally Located G Protein-Coupled Bile Acid Receptors. Endocrinology 2015; 156:3961-70. [PMID: 26280129 PMCID: PMC4606749 DOI: 10.1210/en.2015-1321] [Citation(s) in RCA: 241] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Bile acids are well-recognized stimuli of glucagon-like peptide-1 (GLP-1) secretion. This action has been attributed to activation of the G protein-coupled bile acid receptor GPBAR1 (TGR5), although other potential bile acid sensors include the nuclear farnesoid receptor and the apical sodium-coupled bile acid transporter ASBT. The aim of this study was to identify pathways important for GLP-1 release and to determine whether bile acids target their receptors on GLP-1-secreting L-cells from the apical or basolateral compartment. Using transgenic mice expressing fluorescent sensors specifically in L-cells, we observed that taurodeoxycholate (TDCA) and taurolithocholate (TLCA) increased intracellular cAMP and Ca(2+). In primary intestinal cultures, TDCA was a more potent GLP-1 secretagogue than taurocholate (TCA) and TLCA, correlating with a stronger Ca(2+) response to TDCA. Using small-volume Ussing chambers optimized for measuring GLP-1 secretion, we found that both a GPBAR1 agonist and TDCA stimulated GLP-1 release better when applied from the basolateral than from the luminal direction and that luminal TDCA was ineffective when intestinal tissue was pretreated with an ASBT inhibitor. ASBT inhibition had no significant effect in nonpolarized primary cultures. Studies in the perfused rat gut confirmed that vascularly administered TDCA was more effective than luminal TDCA. Intestinal primary cultures and Ussing chamber-mounted tissues from GPBAR1-knockout mice did not secrete GLP-1 in response to either TLCA or TDCA. We conclude that the action of bile acids on GLP-1 secretion is predominantly mediated by GPBAR1 located on the basolateral L-cell membrane, suggesting that stimulation of gut hormone secretion may include postabsorptive mechanisms.
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28
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Chater PI, Wilcox MD, Pearson JP, Brownlee IA. The impact of dietary fibres on the physiological processes governing small intestinal digestive processes. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.bcdf.2015.09.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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29
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Spreckley E, Murphy KG. The L-Cell in Nutritional Sensing and the Regulation of Appetite. Front Nutr 2015; 2:23. [PMID: 26258126 PMCID: PMC4507148 DOI: 10.3389/fnut.2015.00023] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/06/2015] [Indexed: 12/25/2022] Open
Abstract
The gastrointestinal (GI) tract senses the ingestion of food and responds by signaling to the brain to promote satiation and satiety. Representing an important part of the gut-brain axis, enteroendocrine L-cells secrete the anorectic peptide hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) in response to the ingestion of food. The release of GLP-1 has multiple effects, including the secretion of insulin from pancreatic β-cells, decreased gastric emptying, and increased satiation. PYY also slows GI motility and reduces food intake. At least part of the gut-brain response seems to be due to direct sensing of macronutrients by L-cells, by mechanisms including specific nutrient-sensing receptors. Such receptors may represent possible pathways to target to decrease appetite and increase energy expenditure. Designing drugs or functional foods to exploit the machinery of these nutrient-sensing mechanisms may offer a potential approach for agents to treat obesity and metabolic disease.
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Affiliation(s)
- Eleanor Spreckley
- Section of Investigative Medicine, Department of Medicine, Imperial College London, Hammersmith Hospital , London , UK
| | - Kevin Graeme Murphy
- Section of Investigative Medicine, Department of Medicine, Imperial College London, Hammersmith Hospital , London , UK
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30
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Mace OJ, Tehan B, Marshall F. Pharmacology and physiology of gastrointestinal enteroendocrine cells. Pharmacol Res Perspect 2015. [PMID: 26213627 PMCID: PMC4506687 DOI: 10.1002/prp2.155] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Gastrointestinal (GI) polypeptides are secreted from enteroendocrine cells (EECs). Recent technical advances and the identification of endogenous and synthetic ligands have enabled exploration of the pharmacology and physiology of EECs. Enteroendocrine signaling pathways stimulating hormone secretion involve multiple nutrient transporters and G protein-coupled receptors (GPCRs), which are activated simultaneously under prevailing nutrient conditions in the intestine following a meal. The majority of studies investigate hormone secretion from EECs in response to single ligands and although the mechanisms behind how individual signaling pathways generate a hormonal output have been well characterized, our understanding of how these signaling pathways converge to generate a single hormone secretory response is still in its infancy. However, a picture is beginning to emerge of how nutrients and full, partial, or allosteric GPCR ligands differentially regulate the enteroendocrine system and its interaction with the enteric and central nervous system. So far, activation of multiple pathways underlies drug discovery efforts to harness the therapeutic potential of the enteroendocrine system to mimic the phenotypic changes observed in patients who have undergone Roux-en-Y gastric surgery. Typically obese patients exhibit ∼30% weight loss and greater than 80% of obese diabetics show remission of diabetes. Targeting combinations of enteroendocrine signaling pathways that work synergistically may manifest with significant, differentiated EEC secretory efficacy. Furthermore, allosteric modulators with their increased selectivity, self-limiting activity, and structural novelty may translate into more promising enteroendocrine drugs. Together with the potential to bias enteroendocrine GPCR signaling and/or to activate multiple divergent signaling pathways highlights the considerable range of therapeutic possibilities available. Here, we review the pharmacology and physiology of the EEC system.
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Affiliation(s)
- O J Mace
- Heptares Therapeutics Ltd BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, United Kingdom
| | - B Tehan
- Heptares Therapeutics Ltd BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, United Kingdom
| | - F Marshall
- Heptares Therapeutics Ltd BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, United Kingdom
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31
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Glucagon-like peptide 1 and peptide YY are in separate storage organelles in enteroendocrine cells. Cell Tissue Res 2014; 357:63-9. [DOI: 10.1007/s00441-014-1886-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/27/2014] [Indexed: 12/17/2022]
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