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Barton JR, Londregan AK, Alexander TD, Entezari AA, Covarrubias M, Waldman SA. Enteroendocrine cell regulation of the gut-brain axis. Front Neurosci 2023; 17:1272955. [PMID: 38027512 PMCID: PMC10662325 DOI: 10.3389/fnins.2023.1272955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Enteroendocrine cells (EECs) are an essential interface between the gut and brain that communicate signals about nutrients, pain, and even information from our microbiome. EECs are hormone-producing cells expressed throughout the gastrointestinal epithelium and have been leveraged by pharmaceuticals like semaglutide (Ozempic, Wegovy), terzepatide (Mounjaro), and retatrutide (Phase 2) for diabetes and weight control, and linaclotide (Linzess) to treat irritable bowel syndrome (IBS) and visceral pain. This review focuses on role of intestinal EECs to communicate signals from the gut lumen to the brain. Canonically, EECs communicate information about the intestinal environment through a variety of hormones, dividing EECs into separate classes based on the hormone each cell type secretes. Recent studies have revealed more diverse hormone profiles and communication modalities for EECs including direct synaptic communication with peripheral neurons. EECs known as neuropod cells rapidly relay signals from gut to brain via a direct communication with vagal and primary sensory neurons. Further, this review discusses the complex information processing machinery within EECs, including receptors that transduce intraluminal signals and the ion channel complement that govern initiation and propagation of these signals. Deeper understanding of EEC physiology is necessary to safely treat devastating and pervasive conditions like irritable bowel syndrome and obesity.
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Affiliation(s)
- Joshua R. Barton
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Annie K. Londregan
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Tyler D. Alexander
- Department of Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ariana A. Entezari
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Manuel Covarrubias
- Department of Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Scott A. Waldman
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
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Tan FPY, Beltranena E, Zijlstra RT. Resistant starch: Implications of dietary inclusion on gut health and growth in pigs: a review. J Anim Sci Biotechnol 2021; 12:124. [PMID: 34784962 PMCID: PMC8597317 DOI: 10.1186/s40104-021-00644-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [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: 06/13/2021] [Accepted: 10/07/2021] [Indexed: 01/10/2023] Open
Abstract
Starch from cereal grains, pulse grains, and tubers is a major energy substrate in swine rations constituting up to 55% of the diet. In pigs, starch digestion is initiated by salivary and then pancreatic α-amylase, and has as final step the digestion of disaccharides by the brush-border enzymes in the small intestine that produce monosaccharides (glucose) for absorption. Resistant starch (RS) is the proportion of starch that escapes the enzymatic digestion and absorption in the small intestine. The undigested starch reaches the distal small intestine and hindgut for microbial fermentation, which produces short-chain fatty acids (SCFA) for absorption. SCFA in turn, influence microbial ecology and gut health of pigs. These fermentative metabolites exert their benefits on gut health through promoting growth and proliferation of enterocytes, maintenance of intestinal integrity and thus immunity, and modulation of the microbial community in part by suppressing the growth of pathogenic bacteria while selectively enhancing beneficial microbes. Thus, RS has the potential to confer prebiotic effects and may contribute to the improvement of intestinal health in pigs during the post-weaning period. Despite these benefits to the well-being of pigs, RS has a contradictory effect due to lower energetic efficiency of fermented vs. digested starch absorption products. The varying amount and type of RS interact differently with the digestion process along the gastrointestinal tract affecting its energy efficiency and host physiological responses including feed intake, energy metabolism, and feed efficiency. Results of research indicate that the use of RS as prebiotic may improve gut health and thereby, reduce the incidence of post-weaning diarrhea (PWD) and associated mortality. This review summarizes our current knowledge on the effects of RS on microbial ecology, gut health and growth performance in pigs.
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Affiliation(s)
- Felina P Y Tan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Eduardo Beltranena
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Ruurd T Zijlstra
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
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Zhou K, Zhou Y, Yang D, Chen T, Liu X, Li S, Wang Z. The type 3 adenylyl cyclase is crucial for intestinal mucosal neural network in the gut lamina propria. Neurogastroenterol Motil 2021; 33:e14140. [PMID: 33939232 DOI: 10.1111/nmo.14140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 02/13/2021] [Accepted: 03/02/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND The type 3 adenylyl cyclase (AC3) enzyme is involved in the synthesis of cyclic adenosine monophosphate (cAMP). It is primarily expressed in the central nervous system (CNS) and plays a crucial role in neurogenesis and neural dendritic arborization. However, the AC3's functional role in the gastrointestinal tract remains ambiguous. METHODS AC3 expression in enteric tissue of AC3+/+ mice was investigated using immunohistochemistry and RT-PCR. AC3 knock-out mice (AC3-/- ) were used to examine the effect of AC3 on the enteric nervous system (ENS) function and the number of cilia and apoptotic cells. Additionally, total gastrointestinal transit time and colonic motility were compared between the AC3-/- and AC3+/+ groups of mice. KEY RESULTS AC3 was predominately expressed in the myenteric plexus of the large intestine. Colonic-bead expulsion analysis showed accelerated propulsion in the large intestine of the AC3-/- mice. The AC3-/- mice demonstrated reduced nerve fibers and enteric glial cells count in colonic mucosa compared to the AC3+/+ mice. Furthermore, AC3-/- mice exhibited increased cellular apoptosis and reduced ARL13B+ cilium cells in the colonic lamina propria compared to the AC3+/+ mice. CONCLUSIONS In AC3-/- mice, innervation of the lamina propria in the colonic mucosa was reduced and colonic propulsion was accelerated. AC3 is crucial for the development and function of the adult neural network of ENS. AC3 deficiency caused atrophy in the colonic mucosal neural network of mice.
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Affiliation(s)
- Kang Zhou
- College of Life Science, Hebei University, Baoding, China
| | - Yanfen Zhou
- College of Life Science, Hebei University, Baoding, China
| | - Dong Yang
- College of Life Science, Hebei University, Baoding, China
| | - Tingrong Chen
- College of Life Science, Hebei University, Baoding, China
| | - Xinxia Liu
- College of Life Science, Hebei University, Baoding, China.,Medical College, Hebei University, Baoding, China
| | - Shujuan Li
- College of Life Science, Hebei University, Baoding, China
| | - Zhenshan Wang
- College of Life Science, Hebei University, Baoding, China
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4
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Abstract
PURPOSE OF REVIEW Enteroendocrine cells (EECs) are scattered chemosensory cells in the intestinal epithelium that release hormones with a wide range of actions on intestinal function, food intake and glucose homeostasis. The mechanisms by which gut hormones are secreted postprandially, or altered by antidiabetic agents and surgical interventions are of considerable interest for future therapeutic development. RECENT FINDINGS EECs are electrically excitable and express a repertoire of G-protein coupled receptors that sense nutrient and nonnutrient stimuli, coupled to intracellular Ca2+ and cyclic adenosine monophosphate. Our knowledge of EEC function, previously developed using mouse models, has recently been extended to human cells. Gut hormone release in humans is enhanced by bariatric surgery, as well as by some antidiabetic agents including sodium-coupled glucose transporter inhibitors and metformin. SUMMARY EECs are important potential therapeutic targets. A better understanding of their chemosensory mechanisms will enhance the development of new therapeutic strategies to treat metabolic and gastrointestinal diseases.
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Affiliation(s)
- Ming Yang
- University of Cambridge, Institute of Metabolic Science and MRC Metabolic Diseases Unit, Addenbrooke's Hospital, Cambridge, UK
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5
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Dye FS, Larraufie P, Kay R, Darwish T, Rievaj J, Goldspink DA, Meek CL, Middleton SJ, Hardwick RH, Roberts GP, Percival-Alwyn JL, Vaughan T, Ferraro F, Challis BG, O'Rahilly S, Groves M, Gribble FM, Reimann F. Characterisation of proguanylin expressing cells in the intestine - evidence for constitutive luminal secretion. Sci Rep 2019; 9:15574. [PMID: 31666564 PMCID: PMC6821700 DOI: 10.1038/s41598-019-52049-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 07/11/2019] [Accepted: 10/10/2019] [Indexed: 12/14/2022] Open
Abstract
Guanylin, a peptide implicated in regulation of intestinal fluid secretion, is expressed in the mucosa, but the exact cellular origin remains controversial. In a new transgenic mouse model fluorescent reporter protein expression driven by the proguanylin promoter was observed throughout the small intestine and colon in goblet and Paneth(-like) cells and, except in duodenum, in mature enterocytes. In Ussing chamber experiments employing both human and mouse intestinal tissue, proguanylin was released predominantly in the luminal direction. Measurements of proguanylin expression and secretion in cell lines and organoids indicated that secretion is largely constitutive and requires ER to Golgi transport but was not acutely regulated by salt or other stimuli. Using a newly-developed proguanylin assay, we found plasma levels to be raised in humans after total gastrectomy or intestinal transplantation, but largely unresponsive to nutrient ingestion. By LC-MS/MS we identified processed forms in tissue and luminal extracts, but in plasma we only detected full-length proguanylin. Our transgenic approach provides information about the cellular origins of proguanylin, complementing previous immunohistochemical and in-situ hybridisation results. The identification of processed forms of proguanylin in the intestinal lumen but not in plasma supports the notion that the primary site of action is the gut itself.
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Affiliation(s)
- Florent Serge Dye
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.,Department of Antibody Discovery and Protein Engineering, R&D, AstraZeneca, Cambridge, UK
| | - Pierre Larraufie
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Richard Kay
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Tamana Darwish
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Juraj Rievaj
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.,Dosage Form Design & Development, AstraZeneca, Cambridge, UK
| | - Deborah A Goldspink
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Claire L Meek
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Stephen J Middleton
- Department of Gastroenterology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Richard H Hardwick
- Barrett's Oesophagus and Oesophago-gastric Cancer, Gastroenterology Services, Addenbrooke's Hospital, Cambridge, UK
| | - Geoffrey P Roberts
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | | | - Tris Vaughan
- Department of Antibody Discovery and Protein Engineering, R&D, AstraZeneca, Cambridge, UK
| | - Franco Ferraro
- Department of Antibody Discovery and Protein Engineering, R&D, AstraZeneca, Cambridge, UK
| | - Benjamin G Challis
- Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Stephen O'Rahilly
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Maria Groves
- Department of Antibody Discovery and Protein Engineering, R&D, AstraZeneca, Cambridge, UK.
| | - Fiona M Gribble
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Frank Reimann
- Wellcome/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.
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Abstract
The organs require oxygen and other types of nutrients (amino acids, sugars, and lipids) to function, the heart consuming large amounts of fatty acids for oxidation and adenosine triphosphate (ATP) generation.
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7
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Muo IM, MacDonald SD, Madan R, Park SJ, Gharib AM, Martinez PE, Walter MF, Yang SB, Rodante JA, Courville AB, Walter PJ, Cai H, Glicksman M, Guerrieri GM, Ben-Dor RR, Ouwerkerk R, Mao S, Chung JH. Early effects of roflumilast on insulin sensitivity in adults with prediabetes and overweight/obesity involve age-associated fat mass loss - results of an exploratory study. Diabetes Metab Syndr Obes 2019; 12:743-759. [PMID: 31213865 PMCID: PMC6542328 DOI: 10.2147/dmso.s182953] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Roflumilast (Daliresp, Daxas) is a FDA-approved phosphodiesterase 4 (PDE4) inhibitor for the treatment of moderate-to-severe chronic obstructive pulmonary disease. In mice and in limited human studies, this oral medication can cause weight loss and improve insulin sensitivity. We set out to determine the mechanism of its effect on insulin sensitivity. PATIENTS AND METHODS Eight adults with overweight/obesity and prediabetes received roflumilast for 6 weeks. Before and after roflumilast, subjects underwent tests of insulin sensitivity, mixed meal test, body composition, markers of inflammation, and mitochondria function. Dietary intake and physical activity were also assessed. Our primary outcome was the change in peripheral insulin sensitivity, as assessed by the hyper-insulinemic euglycemic clamp. RESULTS This study was underpowered for the primary outcome. Pre- and post-roflumilast mean peripheral insulin sensitivity were 48.7 and 70.0 mg/g fat free mass/minute, respectively, (P-value=0.18), respectively. Among the mixed meal variables, roflumilast altered glucagon-like peptide 1 (GLP-1) hormone the most, although the average effect was not statistically significant (P=0.18). Roflumilast induced a trend toward significance in 1) decreased energy intake (from 11,095 KJ to 8,4555 KJ, P=0.07), 2) decreased fat mass (from 34.53 to 32.97 kg, P=0.06), 3) decreased total and LDL cholesterol (P=0.06 for both variables), and 4) increased plasma free fatty acids (from 0.40 to 0.50 mEq/L, P=0.09) The interval changes in adiposity and free fatty acid were significantly associated with the subject's age (P-value range= <0.001 to 0.02 for the correlations). Inflammatory and adhesion markers, though unchanged, significantly correlated with one another and with incretin hormones only after roflumilast. CONCLUSION We demonstrate, for the first time in humans, increasing percentage of fat mass loss from roflumilast with increasing age in adults with prediabetes and overweight/obesity. We also demonstrate novel associations among roflumilast-induced changes in incretin hormones, inflammatory markers, peripheral insulin sensitivity, and adiposity. We conclude that roflumilast's early effects on insulin sensitivity is indirect and likely mediated through roflumilast's prioritization of lipid over glucose handling. CLINICAL TRIALS REGISTRATION NCT01862029.
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Affiliation(s)
- Ijeoma M Muo
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
| | - Sandra D MacDonald
- NHLBI Pulmonary Branch, Laboratory of Chronic Airway Infections, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ritu Madan
- Diabetes Endocrinology and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sung-Jun Park
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
| | - Ahmed M Gharib
- Biomedical and Metabolic Imaging Branch NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pedro E Martinez
- Section on Behavioral Endocrinology, NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mary F Walter
- Diabetes Endocrinology and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shanna B Yang
- Clinical Center Nutrition Department, National Institutes of Health, Bethesda, MD 20892, USA
| | - Justin A Rodante
- Laboratory of Inflammation and Cardiometabolic Diseases, NHLBI, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amber B Courville
- Clinical Center Nutrition Department, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter J Walter
- Mass Spectrometry Clinical Core, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hongyi Cai
- Mass Spectrometry Clinical Core, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael Glicksman
- Diabetes Endocrinology and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gioia M Guerrieri
- Section on Behavioral Endocrinology, NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rivka R Ben-Dor
- NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ronald Ouwerkerk
- Biomedical and Metabolic Imaging Branch NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephanie Mao
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
| | - Jay H Chung
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
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8
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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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de Matos AM, de Macedo MP, Rauter AP. Bridging Type 2 Diabetes and Alzheimer's Disease: Assembling the Puzzle Pieces in the Quest for the Molecules With Therapeutic and Preventive Potential. Med Res Rev 2017; 38:261-324. [PMID: 28422298 DOI: 10.1002/med.21440] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/18/2017] [Accepted: 02/14/2017] [Indexed: 12/19/2022]
Abstract
Type 2 diabetes (T2D) and Alzheimer's disease (AD) are two age-related amyloid diseases that affect millions of people worldwide. Broadly supported by epidemiological data, the higher incidence of AD among type 2 diabetic patients led to the recognition of T2D as a tangible risk factor for the development of AD. Indeed, there is now growing evidence on brain structural and functional abnormalities arising from brain insulin resistance and deficiency, ultimately highlighting the need for new approaches capable of preventing the development of AD in type 2 diabetic patients. This review provides an update on overlapping pathophysiological mechanisms and pathways in T2D and AD, such as amyloidogenic events, oxidative stress, endothelial dysfunction, aberrant enzymatic activity, and even shared genetic background. These events will be presented as puzzle pieces put together, thus establishing potential therapeutic targets for drug discovery and development against T2D and diabetes-induced cognitive decline-a heavyweight contributor to the increasing incidence of dementia in developed countries. Hoping to pave the way in this direction, we will present some of the most promising and well-studied drug leads with potential against both pathologies, including their respective bioactivity reports, mechanisms of action, and structure-activity relationships.
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Affiliation(s)
- Ana Marta de Matos
- Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016, Lisbon, Portugal.,CEDOC Chronic Diseases, Nova Medical School, Rua Câmara Pestana n 6, 6-A, Ed. CEDOC II, 1150-082, Lisbon, Portugal
| | - Maria Paula de Macedo
- CEDOC Chronic Diseases, Nova Medical School, Rua Câmara Pestana n 6, 6-A, Ed. CEDOC II, 1150-082, Lisbon, Portugal
| | - Amélia Pilar Rauter
- Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016, Lisbon, Portugal
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Hodge D, Glass LL, Diakogiannaki E, Pais R, Lenaghan C, Smith DM, Wedin M, Bohlooly-Y M, Gribble FM, Reimann F. Lipid derivatives activate GPR119 and trigger GLP-1 secretion in primary murine L-cells. Peptides 2016; 77:16-20. [PMID: 26144594 PMCID: PMC4788502 DOI: 10.1016/j.peptides.2015.06.012] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 06/19/2015] [Accepted: 06/23/2015] [Indexed: 02/01/2023]
Abstract
AIMS/HYPOTHESIS Glucagon-like peptide-1 (GLP-1) is an incretin hormone derived from proglucagon, which is released from intestinal L-cells and increases insulin secretion in a glucose dependent manner. GPR119 is a lipid derivative receptor present in L-cells, believed to play a role in the detection of dietary fat. This study aimed to characterize the responses of primary murine L-cells to GPR119 agonism and assess the importance of GPR119 for the detection of ingested lipid. METHODS GLP-1 secretion was measured from murine primary cell cultures stimulated with a panel of GPR119 ligands. Plasma GLP-1 levels were measured in mice lacking GPR119 in proglucagon-expressing cells and controls after lipid gavage. Intracellular cAMP responses to GPR119 agonists were measured in single primary L-cells using transgenic mice expressing a cAMP FRET sensor driven by the proglucagon promoter. RESULTS L-cell specific knockout of GPR119 dramatically decreased plasma GLP-1 levels after a lipid gavage. GPR119 ligands triggered GLP-1 secretion in a GPR119 dependent manner in primary epithelial cultures from the colon, but were less effective in the upper small intestine. GPR119 agonists elevated cAMP in ∼70% of colonic L-cells and 50% of small intestinal L-cells. CONCLUSIONS/INTERPRETATION GPR119 ligands strongly enhanced GLP-1 release from colonic cultures, reflecting the high proportion of colonic L-cells that exhibited cAMP responses to GPR119 agonists. Less GPR119-dependence could be demonstrated in the upper small intestine. In vivo, GPR119 in L-cells plays a key role in oral lipid-triggered GLP-1 secretion.
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Affiliation(s)
- Daryl Hodge
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Leslie L Glass
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Eleftheria Diakogiannaki
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Ramona Pais
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Carol Lenaghan
- AstraZeneca, Cardiovascular & Metabolic Diseases iMed, Alderley Park, Cheshire, UK
| | - David M Smith
- AstraZeneca, Cardiovascular & Metabolic Diseases iMed, Mölndal, Sweden
| | - Marianne Wedin
- AstraZeneca, Transgenics Group, Reagents & Assay Development, Discovery Sciences, Mölndal, Sweden
| | - Mohammad Bohlooly-Y
- AstraZeneca, Transgenics Group, Reagents & Assay Development, Discovery Sciences, Mölndal, Sweden
| | - Fiona M Gribble
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
| | - Frank Reimann
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
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Psichas A, Glass LL, Sharp SJ, Reimann F, Gribble FM. Galanin inhibits GLP-1 and GIP secretion via the GAL1 receptor in enteroendocrine L and K cells. Br J Pharmacol 2016; 173:888-98. [PMID: 26661062 PMCID: PMC4761093 DOI: 10.1111/bph.13407] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 11/26/2015] [Accepted: 12/03/2015] [Indexed: 12/19/2022] Open
Abstract
Background and Purpose Galanin is a widely expressed neuropeptide, which in the gut is thought to modulate gastrointestinal motility and secretion. We aimed to elucidate the poorly characterised mechanisms underlying the inhibitory effect of galanin and the potential involvement of G‐protein coupled inwardly rectifying potassium, Kir3, (GIRK) channels in glucagon‐like peptide 1 (GLP‐1) and glucose‐dependent insulinotropic polypeptide (GIP) secretion. Experimental Approach Purified murine L and K cells were analysed for expression of galanin receptors and GIRK subunits. Hormone secretion was measured from primary murine intestinal cultures. Intracellular cAMP was monitored in primary L cells derived from mice expressing the Epac2camps sensor under the control of the proglucagon promoter. Key Results Galanin receptor 1 (GAL1, Galr1) and GIRK channel 1 (Kir3.1, Kcnj3) and 4 (Kir3.4, Kcnj5) mRNA expression was highly enriched in K and L cells. Galanin and a selective GAL1 receptor agonist (M617) potently inhibited GLP‐1 and GIP secretion from primary small intestinal cultures. In L cells, galanin significantly inhibited the forskolin‐induced cAMP response. The GIRK1/4 activator ML297 significantly reduced glucose‐stimulated and IBMX‐stimulated GLP‐1 secretion but had no effect on GIP. The GIRK blocker tertiapin‐Q did not impair galanin‐mediated GLP‐1 inhibition. Conclusions and Implications Galanin, acting via the GAL1 receptor and Gi‐coupled signalling in L and K cells, is a potent inhibitor of GLP‐1 and GIP secretion. Although GIRK1/4 channels are expressed in these cells, their activation does not appear to play a major role in galanin‐mediated inhibition of incretin secretion.
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Affiliation(s)
- Arianna Psichas
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Leslie L Glass
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Stephen J Sharp
- MRC Epidemiology Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Frank Reimann
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Fiona M Gribble
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
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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: 226] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [What about the content of this article? (0)] [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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13
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Raab S, Wang H, Uhles S, Cole N, Alvarez-Sanchez R, Künnecke B, Ullmer C, Matile H, Bedoucha M, Norcross RD, Ottaway-Parker N, Perez-Tilve D, Conde Knape K, Tschöp MH, Hoener MC, Sewing S. Incretin-like effects of small molecule trace amine-associated receptor 1 agonists. Mol Metab 2015; 5:47-56. [PMID: 26844206 PMCID: PMC4703809 DOI: 10.1016/j.molmet.2015.09.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 09/21/2015] [Accepted: 09/22/2015] [Indexed: 12/05/2022] Open
Abstract
Objective Type 2 diabetes and obesity are emerging pandemics in the 21st century creating worldwide urgency for the development of novel and safe therapies. We investigated trace amine-associated receptor 1 (TAAR1) as a novel target contributing to the control of glucose homeostasis and body weight. Methods We investigated the peripheral human tissue distribution of TAAR1 by immunohistochemistry and tested the effect of a small molecule TAAR1 agonist on insulin secretion in vitro using INS1E cells and human islets and on glucose tolerance in C57Bl6, and db/db mice. Body weight effects were investigated in obese DIO mice. Results TAAR1 activation by a selective small molecule agonist increased glucose-dependent insulin secretion in INS1E cells and human islets and elevated plasma PYY and GLP-1 levels in mice. In diabetic db/db mice, the TAAR1 agonist normalized glucose excursion during an oral glucose tolerance test. Sub-chronic treatment of diet-induced obese (DIO) mice with the TAAR1 agonist resulted in reduced food intake and body weight. Furthermore insulin sensitivity was improved and plasma triglyceride levels and liver triglyceride content were lower than in controls. Conclusions We have identified TAAR1 as a novel integrator of metabolic control, which acts on gastrointestinal and pancreatic islet hormone secretion. Thus TAAR1 qualifies as a novel and promising target for the treatment of type 2 diabetes and obesity. TAAR1 is a novel key player in metabolic control. TAAR1 is expressed in β-cells and intestinal enteroendocrine cells in mice and humans. TAAR1 agonist improved glucose tolerance and reduced body weight in mouse disease models.
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Affiliation(s)
- Susanne Raab
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Haiyan Wang
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Sabine Uhles
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Nadine Cole
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Ruben Alvarez-Sanchez
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Basil Künnecke
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Christoph Ullmer
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Hugues Matile
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Marc Bedoucha
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Roger D Norcross
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Nickki Ottaway-Parker
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, OH 45237, USA
| | - Diego Perez-Tilve
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, OH 45237, USA
| | - Karin Conde Knape
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Matthias H Tschöp
- Helmholtz Diabetes Center, Helmholtz Zentrum München and Division of Metabolic Diseases, Technische Universität München, Germany
| | - Marius C Hoener
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Sabine Sewing
- Roche Pharma Research & Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
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14
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Abstract
Obesity is associated with systemic inflammation and elevated levels of TNFα, leading to impaired glucose tolerance. In humans, obesity is also associated with reduced nutrient-stimulated secretion of the intestinal incretin hormone, glucagon-like peptide-1 (GLP-1). We hypothesized that TNFα plays a direct role in the impairment of GLP-1 secretion from the enteroendocrine L-cell and that blocking TNFα can restore both GLP-1 secretion and glucose homeostasis. Expression of the TNFα receptor subytpe-1 was detected in the human NCI-H716 and murine GLUTag L-cell models and in mouse ileal sections. Although TNFα acutely increased GLP-1 release from NCI-H716 cells (P < .05-.001), preincubation with TNFα for 24 hours reduced proglucagon mRNA (P < .05) and GLP-1 cellular (P < .05) levels without affecting cell viability. Furthermore, both NCI-H716 and GLUTag cells pretreated with TNFα for 24 hours no longer responded to known GLP-1 secretagogues, an effect that was reversed by coincubation with the Nuclear Factor Kappa B inhibitor, 5-aminosalicylic acid, in the NCI-H716 cells. Mice given a high-fat diet (HFD) for 12 weeks developed impaired glucose tolerance, hyperinsulinemia, and increased TNFα mRNA expression in fat and ileal tissue. Hyperglycemia and hyperinsulinemia were reduced in HFD mice treated with the anti-TNFα biological, etanercept, for 2 weeks. In primary intestinal cultures from these animals, HFD control mice had impaired GLP-1 secretion, and this was not observed in the HFD etanercept-derived cultures (P < .05). In conclusion, chronic exposure to TNFα directly impairs GLP-1 secretion at the level of the intestinal L-cell, an effect that is reversed by anti-TNFα therapy in association with improved glucose tolerance.
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Affiliation(s)
- Jeffrey Gagnon
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
| | - Meghan Sauvé
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
| | - Wen Zhao
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
| | - Holly M Stacey
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
| | - Stuart C Wiber
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
| | - Steffen-S Bolz
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
| | - Patricia L Brubaker
- Departments of Physiology (J.G., M.S., W.Z., H.M.S., S.C.W., S.-S.B., P.L.B.) and Medicine (P.L.B.), University of Toronto, Toronto, Ontario, M5S 1A8 Canada; and Centre for Microvascular Medicine (S.-S.B.), University of Toronto and Li Ka Shing Knowledge Institute at St Michael's Hospital, Toronto, Ontario, M5B 1T8 Canada
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15
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Abstract
The enteroendocrine system orchestrates how the body responds to the ingestion of foods, employing a diversity of hormones to fine-tune a wide range of physiological responses both within and outside the gut. Recent interest in gut hormones has surged with the realization that they modulate glucose tolerance and food intake through a variety of mechanisms, and such hormones are therefore excellent therapeutic candidates for the treatment of diabetes and obesity. Characterizing the roles and functions of different enteroendocrine cells is an essential step in understanding the physiology, pathophysiology, and therapeutics of the gut-brain-pancreas axis.
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Affiliation(s)
- Fiona M Gribble
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, and Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; ,
| | - Frank Reimann
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, and Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; ,
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16
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Chimerel C, Emery E, Summers DK, Keyser U, Gribble FM, Reimann F. Bacterial metabolite indole modulates incretin secretion from intestinal enteroendocrine L cells. Cell Rep 2014; 9:1202-8. [PMID: 25456122 DOI: 10.1016/j.celrep.2014.10.032] [Citation(s) in RCA: 323] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/22/2014] [Accepted: 10/10/2014] [Indexed: 12/25/2022] Open
Abstract
It has long been speculated that metabolites, produced by gut microbiota, influence host metabolism in health and diseases. Here, we reveal that indole, a metabolite produced from the dissimilation of tryptophan, is able to modulate the secretion of glucagon-like peptide-1 (GLP-1) from immortalized and primary mouse colonic L cells. Indole increased GLP-1 release during short exposures, but it reduced secretion over longer periods. These effects were attributed to the ability of indole to affect two key molecular mechanisms in L cells. On the one hand, indole inhibited voltage-gated K+ channels, increased the temporal width of action potentials fired by L cells, and led to enhanced Ca2+ entry, thereby acutely stimulating GLP-1 secretion. On the other hand, indole slowed ATP production by blocking NADH dehydrogenase, thus leading to a prolonged reduction of GLP-1 secretion. Our results identify indole as a signaling molecule by which gut microbiota communicate with L cells and influence host metabolism. Bacterial metabolite indole modulates secretion of incretin peptide GLP-1 Indole widens the width of action potentials fired by L cells and elevates GLP-1 Prolonged exposure to indole inhibits ATP production and thus GLP-1 secretion
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17
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Pais R, Zietek T, Hauner H, Daniel H, Skurk T. RANTES (CCL5) reduces glucose-dependent secretion of glucagon-like peptides 1 and 2 and impairs glucose-induced insulin secretion in mice. Am J Physiol Gastrointest Liver Physiol 2014; 307:G330-7. [PMID: 24875103 DOI: 10.1152/ajpgi.00329.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Type 2 diabetes is associated with elevated circulating levels of the chemokine RANTES and with decreased plasma levels of the incretin hormone glucagon-like peptide 1 (GLP-1). GLP-1 is a peptide secreted from intestinal L-cells upon nutrient ingestion. It enhances insulin secretion from pancreatic β-cells and protects from β-cell loss but also promotes satiety and weight loss. In search of chemokines that may reduce GLP-1 secretion we identified RANTES and show that it reduces glucose-stimulated GLP-1 secretion in the human enteroendocrine cell line NCI-H716, blocked by the antagonist Met-RANTES, and in vivo in mice. RANTES exposure to mouse intestinal tissues lowers transport function of the intestinal glucose transporter SGLT1, and administration in mice reduces plasma GLP-1 and GLP-2 levels after an oral glucose load and thereby impairs insulin secretion. These data show that RANTES is involved in altered secretion of glucagon-like peptide hormones most probably acting through SGLT1, and our study identifies the RANTES-receptor CCR1 as a potential target in diabetes therapy.
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Affiliation(s)
- Ramona Pais
- ZIEL Research Center of Nutrition and Food Sciences, Nutritional Medicine, Technische Universität München, Freising, Germany; ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany; and
| | - Tamara Zietek
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany; and
| | - Hans Hauner
- ZIEL Research Center of Nutrition and Food Sciences, Nutritional Medicine, Technische Universität München, Freising, Germany; Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Hannelore Daniel
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany; and
| | - Thomas Skurk
- ZIEL Research Center of Nutrition and Food Sciences, Nutritional Medicine, Technische Universität München, Freising, Germany; Klinikum rechts der Isar, Technische Universität München, Munich, Germany
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18
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Mace OJ, Marshall F. DIGESTIVE PHYSIOLOGY OF THE PIG SYMPOSIUM: Gut chemosensing and the regulation of nutrient absorption and energy supply1. J Anim Sci 2013; 91:1932-45. [DOI: 10.2527/jas.2012-5906] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- O. J. Mace
- Heptares Therapeutics, BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, United Kingdom
| | - F. Marshall
- Heptares Therapeutics, BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, United Kingdom
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19
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Abstract
Sweet taste receptor subunits and α-gustducin found in enteroendocrine cells of the small intestine have been implicated in release of the incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) in response to glucose and noncaloric sweeteners. α-Gustducin has also been found in colon, although its function there is unclear. We examined expression of α-gustducin, GLP-1, and GIP throughout the intestine. The number of α-gustducin-expressing cells and those coexpressing α-gustducin together with GLP-1 and/or GIP increased from small intestine to colon. α-Gustducin also was coexpressed with fatty acid G protein-coupled receptor (GPR) 40, GPR41, GPR43, GPR119, GPR120, and bile acid G protein-coupled receptor TGR5 in enteroendocrine cells of the colon. In colon, GPR43 was coexpressed with GPR119 and GPR120, but not with TGR5. Treatment of colonic mucosa isolated from wild-type mice with acetate, butyrate, oleic acid, oleoylethanolamide, or lithocholic acid stimulated GLP-1 secretion. However, GLP-1 release in response to these fatty acids was impaired in colonic tissue from α-gustducin knockout mice.
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Affiliation(s)
- Yan Li
- Monell Chemical Senses Center, 3500 Market St., Philadelphia, PA 19104, USA
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20
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Moss CE, Marsh WJ, Parker HE, Ogunnowo-Bada E, Riches CH, Habib AM, Evans ML, Gribble FM, Reimann F. Somatostatin receptor 5 and cannabinoid receptor 1 activation inhibit secretion of glucose-dependent insulinotropic polypeptide from intestinal K cells in rodents. Diabetologia 2012; 55:3094-103. [PMID: 22872212 PMCID: PMC3464380 DOI: 10.1007/s00125-012-2663-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 07/03/2012] [Indexed: 12/25/2022]
Abstract
AIMS/HYPOTHESIS Glucose-dependent insulinotropic polypeptide (GIP) is an enteroendocrine hormone that promotes storage of glucose and fat. Its secretion from intestinal K cells is triggered by nutrient ingestion and is modulated by intracellular cAMP. In view of the proadipogenic actions of GIP, this study aimed to identify pathways in K cells that lower cAMP levels and GIP secretion. METHODS Murine K cells purified by flow cytometry were analysed for expression of G(αi)-coupled receptors by transcriptomic microarrays. Somatostatin and cannabinoid receptor expression was confirmed by quantitative RT-PCR. Hormone secretion in vitro was measured in GLUTag and primary murine intestinal cultures. cAMP was monitored in GLUTag cells using the genetically encoded sensor Epac2-camps. In vivo tolerance tests were performed in cannulated rats. RESULTS Purified murine K cells expressed high mRNA levels for somatostatin receptors (Sstrs) Sstr2, Sstr3 and Sstr5, and cannabinoid receptor type 1 (Cnr1, CB1). Somatostatin inhibited GIP and glucagon-like peptide-1 (GLP-1) secretion from primary small intestinal cultures, in part through SSTR5, and reduced cAMP generation in GLUTag cells. Although the CB1 agonist methanandamide (mAEA) inhibited GIP secretion, no significant effect was observed on GLP-1 secretion from primary cultures. In cannulated rats, treatment with mAEA prior to an oral glucose tolerance test suppressed plasma GIP but not GLP-1 levels, whereas the CB1 antagonist AM251 elevated basal GIP concentrations. CONCLUSIONS/INTERPRETATION GIP release is inhibited by somatostatin and CB1 agonists. The differential effects of CB1 ligands on GIP and GLP-1 release may provide a new tool to dissociate secretion of these incretin hormones and lower GIP but not GLP-1 levels in vivo.
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MESH Headings
- Animals
- Colon/cytology
- Colon/metabolism
- Cyclic AMP/metabolism
- Enteroendocrine Cells/cytology
- Enteroendocrine Cells/metabolism
- Gastric Inhibitory Polypeptide/metabolism
- Glucagon-Like Peptide 1/metabolism
- Incretins/metabolism
- Intestine, Small/cytology
- Intestine, Small/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Primary Cell Culture
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptors, Somatostatin/genetics
- Receptors, Somatostatin/metabolism
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Affiliation(s)
- C. E. Moss
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke’s Hospital, Box 139, Hills Road, Cambridge, CB2 0XY UK
| | - W. J. Marsh
- Cambridge Metabolic Research Laboratories and Department of Medicine, Addenbrooke’s Hospital, Hills Road, Cambridge, UK
| | - H. E. Parker
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke’s Hospital, Box 139, Hills Road, Cambridge, CB2 0XY UK
| | - E. Ogunnowo-Bada
- Cambridge Metabolic Research Laboratories and Department of Medicine, Addenbrooke’s Hospital, Hills Road, Cambridge, UK
| | - C. H. Riches
- Cambridge Metabolic Research Laboratories and Department of Medicine, Addenbrooke’s Hospital, Hills Road, Cambridge, UK
| | - A. M. Habib
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke’s Hospital, Box 139, Hills Road, Cambridge, CB2 0XY UK
| | - M. L. Evans
- Cambridge Metabolic Research Laboratories and Department of Medicine, Addenbrooke’s Hospital, Hills Road, Cambridge, UK
| | - F. M. Gribble
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke’s Hospital, Box 139, Hills Road, Cambridge, CB2 0XY UK
| | - F. Reimann
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke’s Hospital, Box 139, Hills Road, Cambridge, CB2 0XY UK
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21
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Habib AM, Richards P, Cairns LS, Rogers GJ, Bannon CAM, Parker HE, Morley TCE, Yeo GSH, Reimann F, Gribble FM. Overlap of endocrine hormone expression in the mouse intestine revealed by transcriptional profiling and flow cytometry. Endocrinology 2012; 153:3054-65. [PMID: 22685263 PMCID: PMC3440453 DOI: 10.1210/en.2011-2170] [Citation(s) in RCA: 279] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The intestine secretes a range of hormones with important local and distant actions, including the control of insulin secretion and appetite. A number of enteroendocrine cell types have been described, each characterized by a distinct hormonal signature, such as K-cells producing glucose-dependent insulinotropic polypeptide (GIP), L-cells producing glucagon-like peptide-1 (GLP-1), and I-cells producing cholecystokinin (CCK). To evaluate similarities between L-, K-, and other enteroendocrine cells, primary murine L- and K-cells, and pancreatic α- and β-cells, were purified and analyzed by flow cytometry and microarray-based transcriptomics. By microarray expression profiling, L cells from the upper small intestinal (SI) more closely resembled upper SI K-cells than colonic L-cells. Upper SI L-cell populations expressed message for hormones classically localized to different enteroendocrine cell types, including GIP, CCK, secretin, and neurotensin. By immunostaining and fluorescence-activated cell sorting analysis, most colonic L-cells contained GLP-1 and PeptideYY In the upper SI, most L-cells contained CCK, approximately 10% were GIP positive, and about 20% were PeptideYY positive. Upper SI K-cells exhibited approximately 10% overlap with GLP-1 and 6% overlap with somatostatin. Enteroendocrine-specific transcription factors were identified from the microarrays, of which very few differed between the enteroendocrine cell populations. Etv1, Prox1, and Pax4 were significantly enriched in L-cells vs. K cells by quantitative RT-PCR. In summary, our data indicate a strong overlap between upper SI L-, K-, and I-cells and suggest they may rather comprise a single cell type, within which individual cells exhibit a hormonal spectrum that may reflect factors such as location along the intestine and exposure to dietary nutrients.
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Affiliation(s)
- Abdella M Habib
- Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Addenbrooke's Hospital, Box 139, Hills Road, Cambridge, CB2 0XY, United Kingdom
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22
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Abstract
Ingestion of a meal triggers a range of physiological responses both within and outside the gut, and results in the remote modulation of appetite and glucose homeostasis. Luminal contents are sensed by specialised chemosensitive cells scattered throughout the intestinal epithelium. These enteroendocrine and tuft cells make direct contact with the gut lumen and release a range of chemical mediators, which can either act in a paracrine fashion interacting with neighbouring cells and nerve endings or as classical circulating hormones. At the molecular level, the chemosensory machinery involves multiple and complex signalling pathways including activation of G-protein-coupled receptors and solute carrier transporters. This chapter will discuss our current knowledge of the molecular mechanisms underlying intestinal chemosensation with a particular focus on the relatively well-characterised nutrient-triggered secretion from the enteroendocrine system.
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Affiliation(s)
- Gwen Tolhurst
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0XY, UK
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23
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Parker HE, Wallis K, le Roux CW, Wong KY, Reimann F, Gribble FM. Molecular mechanisms underlying bile acid-stimulated glucagon-like peptide-1 secretion. Br J Pharmacol 2012; 165:414-23. [PMID: 21718300 PMCID: PMC3268195 DOI: 10.1111/j.1476-5381.2011.01561.x] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/31/2011] [Accepted: 06/02/2011] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND AND PURPOSE The glucagon-like peptides GLP-1 and GLP-2 are secreted from enteroendocrine L-cells following nutrient ingestion. Drugs that increase activity of the GLP-1 axis are highly successful therapies for type 2 diabetes, and boosting L-cell secretion is a potential strategy for future diabetes treatment. The aim of the present study was to further our understanding of the bile acid receptor GPBA (TGR5), an L-cell target currently under therapeutic exploration. EXPERIMENTAL APPROACH GLUTag cells and mixed primary murine intestinal cultures were exposed to bile acids and a specific agonist, GPBAR-A. Secretion was measured using hormone assays and intracellular calcium and cAMP responses were monitored using real-time imaging techniques. KEY RESULTS Bile acid-triggered GLP-1 secretion from GLUTag cells was GPBA-dependent, as demonstrated by its abolition following tgr5 siRNA transfection. Bile acids and GPBAR-A increased GLP-1 secretion from intestinal cultures, with evidence for synergy between the effects of glucose and GPBA activation. Elevation of cAMP was observed following GPBA activation in individual GLUTag cells. Direct calcium responses to GPBAR-A were small, but in the presence of the agonist, a subpopulation of cells that was previously poorly glucose-responsive exhibited robust glucose responses. In vivo, increased delivery of bile to more distal regions of the ileum augmented L-cell stimulation. CONCLUSIONS AND IMPLICATIONS GPBA signalling in L-cells involves rapid elevation of cAMP, and enhanced calcium and secretory responses to glucose. Modulation of this receptor therapeutically may be an attractive strategy to enhance GLP-1 secretion and achieve better glycaemic control in diabetic patients.
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Affiliation(s)
- HE Parker
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's HospitalCambridge, UK
| | - K Wallis
- Department of Metabolic Medicine, Imperial College LondonHammersmith Campus, London, UK
| | - CW le Roux
- Department of Metabolic Medicine, Imperial College LondonHammersmith Campus, London, UK
| | - KY Wong
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's HospitalCambridge, UK
| | - F Reimann
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's HospitalCambridge, UK
| | - FM Gribble
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's HospitalCambridge, UK
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Tolhurst G, Zheng Y, Parker HE, Habib AM, Reimann F, Gribble FM. Glutamine triggers and potentiates glucagon-like peptide-1 secretion by raising cytosolic Ca2+ and cAMP. Endocrinology 2011; 152:405-13. [PMID: 21209017 PMCID: PMC3140224 DOI: 10.1210/en.2010-0956] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 11/12/2010] [Indexed: 12/25/2022]
Abstract
L-glutamine stimulates glucagon-like peptide 1 (GLP-1) secretion in human subjects and cell lines. As recent advances have enabled the study of primary GLP-1-releasing L cells, this study aimed to characterize glutamine-sensing pathways in native murine L cells. L cells were identified using transgenic mice with cell-specific expression of fluorescent markers. Cells were studied in primary colonic cultures from adult mice, or purified by flow cytometry for expression analysis. Intracellular Ca(2+) was monitored in cultures loaded with Fura2, and cAMP was studied using Förster resonance energy transfer sensors expressed in GLUTag cells. Asparagine, phenylalanine, and glutamine (10 mm) triggered GLP-1 release from primary cultures, but glutamine was the most efficacious, increasing secretion 1.9-fold with an EC(50) of 0.19 mm. Several amino acids triggered Ca(2+) changes in L cells, comparable in magnitude to that induced by glutamine. Glutamine-induced Ca(2+) responses were abolished in low Na(+) solution and attenuated in Ca(2+) free solution, suggesting a role for Na(+) dependent uptake and Ca(2+) influx. The greater effectiveness of glutamine as a secretagogue was paralleled by its ability to increase cAMP in GLUTag cells. Glutamine elevated intracellular cAMP to 36% of that produced by a maximal stimulus, whereas asparagine only increased intracellular cAMP by 24% and phenylalanine was without effect. Glutamine elevates both cytosolic Ca(2+) and cAMP in L cells, which may account for the effectiveness of glutamine as a GLP-1 secretagogue. Therapeutic agents like glutamine that target synergistic pathways in L cells might play a future role in the treatment of type 2 diabetes.
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Affiliation(s)
- Gwen Tolhurst
- Cambridge Institute for Medical Research, Addenbrooke’s Hospital, Cambridge CB2 0XY, United Kingdom
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