1
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Santos-Hernández M, Reimann F, Gribble FM. Cellular mechanisms of incretin hormone secretion. J Mol Endocrinol 2024; 72:e230112. [PMID: 38240302 PMCID: PMC10959011 DOI: 10.1530/jme-23-0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/19/2024] [Indexed: 02/23/2024]
Abstract
Enteroendocrine cells located along the gastrointestinal epithelium sense different nutrients/luminal contents that trigger the secretion of a variety of gut hormones with different roles in glucose homeostasis and appetite regulation. The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are involved in the regulation of insulin secretion, appetite, food intake and body weight after their nutrient-induced secretion from the gut. GLP-1 mimetics have been developed and used in the treatment of type 2 diabetes mellitus and obesity. Modulating the release of endogenous intestinal hormones may be a promising approach for the treatment of obesity and type 2 diabetes without surgery. For that reason, current understanding of the cellular mechanisms underlying intestinal hormone secretion will be the focus of this review. The mechanisms controlling hormone secretion depend on the nature of the stimulus, involving a variety of signalling pathways including ion channels, nutrient transporters and G-protein-coupled receptors.
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Affiliation(s)
| | - Frank Reimann
- Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
| | - Fiona M Gribble
- Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
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2
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Wang Z, Cui S, Zhang T, Wang W, Li J, Chen YQ, Zhu SL. Akkermansia muciniphila supplementation improves glucose tolerance in intestinal Ffar4 knockout mice during the daily light to dark transition. mSystems 2023; 8:e0057323. [PMID: 37787527 PMCID: PMC10654094 DOI: 10.1128/msystems.00573-23] [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: 06/06/2023] [Accepted: 08/11/2023] [Indexed: 10/04/2023] Open
Abstract
IMPORTANCE Alterations in the intestinal environment are associated with various diseases, and FFAR4 is abundantly enriched in the intestine, where it has been shown to have the ability to regulate intestinal hormone secretion and intestinal microbiota; here, we confirmed previous reports. Meanwhile, we found that intestinal FFAR4 regulates glucagon-like peptide 1 secretion by decreasing Akkermansia muciniphila abundance and show that such change is associated with the level of glucose utilization at ZT12 in mice. Intestinal FFAR4 deficiency leads to severely impaired glucose tolerance at the ZT12 moment in mice, and Akkermansia muciniphila supplementation ameliorates the abnormal glucose utilization at the ZT12 moment caused by FFAR4 deficiency, which is very similar to the dawn phenomenon in diabetic patients. Collectively, our data suggest that intestinal Ffar4 deteriorates glucose tolerance at the daily light to dark transition by affecting Akkermansia muciniphila.
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Affiliation(s)
- Zhe Wang
- Jiangnan University Medical Center, Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Siyuan Cui
- Jiangnan University Medical Center, Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - TingTing Zhang
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Wei Wang
- Jiangnan University Medical Center, Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - JiaYu Li
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Y. Q. Chen
- Jiangnan University Medical Center, Wuxi School of Medicine, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Sheng long Zhu
- Jiangnan University Medical Center, Wuxi School of Medicine, Jiangnan University, Wuxi, China
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3
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Chen J, Deng LL, Xiao XL, Long SY, Deng Y, Peng T, Xie J, Zhang XY. An Association between Decreased Small Intestinal RNA Modification and Disturbed Glucagon-like Peptide-1 Secretion under High-Fat Diet Stress. Nutrients 2023; 15:3707. [PMID: 37686740 PMCID: PMC10490556 DOI: 10.3390/nu15173707] [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: 07/24/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Unhealthy diets rich in fats and/or sugar are considered as the major external cause of the obesity epidemic, which is often accompanied by a significant decrease in gut hormone glucagon-like peptide-1 (GLP1) levels. Numerous studies have demonstrated notable contributions of the gut microbiota in this process. Nevertheless, the underlying mechanism still needs further investigation. The role of epigenetic modifications in gene expression and metabolism has been well demonstrated, with m6A methylation on RNAs being the most prevalent modification throughout their metabolism. In the present study, we found that the expressions of small intestinal Gcg and Pc3, two key genes regulating GLP1 expression, were significantly downregulated in obese mice, associated with reduced GLP1 level. Immunohistochemistry analysis indicated that a high-fat diet slightly increased the density of enteroendocrine L cells in the small intestine, implying that decreased GLP1 levels were not caused by the changes in L cell intensity. Instead, the small intestinal m6A level as well as the expression of known "writers", mettl3/14 and wtap, were found to be positively correlated with the expression of Gcg and Pc3. Fecal microbiota transplantation with feces from normal and obese mice daily to antibiotic-treated mice revealed that dysbiosis in diet-induced obesity was sufficient to reduce serum GLP1, small intestinal m6A level, and intestinal expressions of Gcg, Pc3, and writer genes (mettl3/14, wtap). However, as the most direct and universal methyl donor, the production of fecal S-adenosylmethionine was neither affected by the different dietary patterns nor their shaped microbiota. These results suggested that microbial modulation of the epitranscriptome may be involved in regulating GLP1 expression, and highlighted epitranscriptomic modifications as an additional level of interaction between diet and individual health.
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Affiliation(s)
- Jiang Chen
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
- College of Life Sciences, Sichuan University, Chengdu 610065, China;
| | - Lin-Ling Deng
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
| | - Xing-Lin Xiao
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
| | - Shi-Yuan Long
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
| | - Yuan Deng
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
| | - Tong Peng
- College of Life Sciences, Sichuan University, Chengdu 610065, China;
- Keystonecare Technology (Chengdu) Co., Ltd., No.200 Tianfu 5th Street, Chengdu 610094, China
| | - Jie Xie
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
| | - Xiao-Yu Zhang
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China; (J.C.)
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4
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Lednovich KR, Gough S, Brenner M, Qadri T, Layden BT. G
Protein‐Coupled Receptors in Metabolic Disease. GPCRS AS THERAPEUTIC TARGETS 2022:521-552. [DOI: 10.1002/9781119564782.ch15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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5
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Patti AM, Giglio RV, Papanas N, Serban D, Stoian AP, Pafili K, Al Rasadi K, Rajagopalan K, Rizvi AA, Ciaccio M, Rizzo M. Experimental and Emerging Free Fatty Acid Receptor Agonists for the Treatment of Type 2 Diabetes. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58010109. [PMID: 35056417 PMCID: PMC8779029 DOI: 10.3390/medicina58010109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/08/2022] [Accepted: 01/10/2022] [Indexed: 04/11/2023]
Abstract
The current management of Type 2 Diabetes Mellitus (T2DM) includes incretin-based treatments able to enhance insulin secretion and peripheral insulin sensitivity as well as improve body mass, inflammation, plasma lipids, blood pressure, and cardiovascular outcomes. Dietary Free Fatty Acids (FFA) regulate metabolic and anti-inflammatory processes through their action on incretins. Selective synthetic ligands for FFA1-4 receptors have been developed as potential treatments for T2DM. To comprehensively review the available evidence for the potential role of FFA receptor agonists in the treatment of T2DM, we performed an electronic database search assessing the association between FFAs, T2DM, inflammation, and incretins. Evidence indicates that FFA1-4 agonism increases insulin sensitivity, induces body mass loss, reduces inflammation, and has beneficial metabolic effects. There is a strong inter-relationship between FFAs and incretins. FFA receptor agonism represents a potential target for the treatment of T2DM and may provide an avenue for the management of cardiometabolic risk in susceptible individuals. Further research promises to shed more light on this emerging topic.
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Affiliation(s)
- Angelo Maria Patti
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, School of Medicine, University of Palermo, 90133 Palermo, Italy; (A.M.P.); (M.R.)
| | - Rosaria Vincenza Giglio
- Department of Biomedicine, Neuroscience, and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, University of Palermo, 90127 Palermo, Italy; (R.V.G.); (M.C.)
| | - Nikolaos Papanas
- Diabetes Centre, Second Department of Internal Medicine, Democritus University of Thrace, 68132 Alexandroupolis, Greece; (N.P.); (K.P.)
| | - Dragos Serban
- Forth Surgery Department, Faculty of Medicine, Carol Davila University, 050098 Bucharest, Romania;
| | - Anca Pantea Stoian
- Department of Diabetes, Faculty of Medicine, Nutrition and Metabolic Diseases, Carol Davila University, 050474 Bucharest, Romania;
| | - Kalliopi Pafili
- Diabetes Centre, Second Department of Internal Medicine, Democritus University of Thrace, 68132 Alexandroupolis, Greece; (N.P.); (K.P.)
| | - Khalid Al Rasadi
- Medical Research Center, Sultan Qaboos University, Muscat 123, Oman;
| | - Kanya Rajagopalan
- Department of Medicine, University of Central Florida College of Medicine, Orlando, FL 32827, USA;
| | - Ali A. Rizvi
- Department of Medicine, University of Central Florida College of Medicine, Orlando, FL 32827, USA;
- Division of Endocrinology, Diabetes and Metabolism, University of South Carolina School of Medicine, Columbia, SC 29208, USA
- Correspondence:
| | - Marcello Ciaccio
- Department of Biomedicine, Neuroscience, and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, University of Palermo, 90127 Palermo, Italy; (R.V.G.); (M.C.)
- Department of Laboratory Medicine, University Hospital, 90127 Palermo, Italy
| | - Manfredi Rizzo
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, School of Medicine, University of Palermo, 90133 Palermo, Italy; (A.M.P.); (M.R.)
- Department of Diabetes, Faculty of Medicine, Nutrition and Metabolic Diseases, Carol Davila University, 050474 Bucharest, Romania;
- Division of Endocrinology, Diabetes and Metabolism, University of South Carolina School of Medicine, Columbia, SC 29208, USA
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6
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G-Protein-Coupled Receptors 120 Agonist III Improves Hepatic Inflammation and ER Stress in Steatohepatitis. Dig Dis Sci 2021; 66:1090-1096. [PMID: 32372191 DOI: 10.1007/s10620-020-06280-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 04/16/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND GPR120 plays a crucial role in insulin sensitization, inflammatory responses and obesity and is considered as an attractive potential target for the treatment of metabolic dysfunctions. However, the mechanisms of GPR120 agonist III in NAFLD/NASH treatment are still unclear. AIMS We aimed to evaluate the effect and molecular mechanisms of GPR120 agonist III on NASH, and search for future treatments of human NAFLD/NASH. METHODS The effects of GPR120 agonist III on steatohepatitis were evaluated in mice fed with HFHC diet and MCD diet. The ultrastructural changes of ER were assessed by TEM. Hepatic ROS production was evaluated by DHE staining. Apoptosis and macrophage infiltration were determined by IHC staining. Inflammatory cytokines secretion were examined using mouse XL cytokine array. RESULTS GPR120 agonist III significantly suppressed macrophage infiltration and ROS production and reversed hepatic inflammation, ER stress and apoptosis in dietary-induced steatohepatitis. CONCLUSION GPR120 agonist III will be an attractive treatment method in steatohepatitis, which opens up a new sight for future treatments of human NAFLD/NASH.
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7
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Acute effects of delayed-release hydrolyzed pine nut oil on glucose tolerance, incretins, ghrelin and appetite in healthy humans. Clin Nutr 2020; 40:2169-2179. [PMID: 33059911 DOI: 10.1016/j.clnu.2020.09.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 08/22/2020] [Accepted: 09/27/2020] [Indexed: 12/27/2022]
Abstract
BACGROUND & AIM Pinolenic acid, a major component (~20%) of pine nut oil, is a dual agonist of the free fatty acid receptors, FFA1 and FFA4, which may regulate release of incretins and ghrelin from the gut. Here, we investigated the acute effects of hydrolyzed pine nut oil (PNO-FFA), delivered to the small intestine by delayed-release capsules, on glucose tolerance, insulin, incretin and ghrelin secretion, and appetite. METHODS In two cross-over studies, we evaluated 3 g unhydrolyzed pine nut oil (PNO-TG) or 3 g PNO-FFA versus no oil in eight healthy, non-obese subjects (study 1), and 3 g PNO-FFA or 6 g PNO-FFA versus no oil in ten healthy, overweight/obese subjects (study 2) in both studies given in delayed-release capsules 30 min prior to a 4-h-oral glucose tolerance test (OGTT). Outcomes were circulating levels of glucose, insulin, GLP-1, GIP, ghrelin, appetite and gastrointestinal tolerability during OGTT. RESULTS Both 3 g PNO-FFA in study 1 and 6 g PNO-FFA in study 2 markedly increased GLP-1 levels (p < 0.001) and attenuated ghrelin levels (p < 0.001) during the last 2 h of the OGTT compared with no oil. In study 2, these effects of PNO-FFA were accompanied by an increased satiety and fullness (p < 0.03), and decreased prospective food consumption (p < 0.05). PNO-FFA caused only small reductions in glucose and insulin levels during the first 2 h of the OGTT. CONCLUSIONS Our results provide evidence that PNO-FFA delivered to the small intestine by delayed-release capsules may reduce appetite by augmenting GLP-1 release and attenuating ghrelin secretion in the late postprandial state. CLINICAL TRIAL REGISTRY NUMBERS NCT03062592 and NCT03305367.
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8
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Goldspink DA, Lu VB, Miedzybrodzka EL, Smith CA, Foreman RE, Billing LJ, Kay RG, Reimann F, Gribble FM. Labeling and Characterization of Human GLP-1-Secreting L-cells in Primary Ileal Organoid Culture. Cell Rep 2020; 31:107833. [PMID: 32610134 PMCID: PMC7342002 DOI: 10.1016/j.celrep.2020.107833] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/10/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) from intestinal L-cells stimulates insulin secretion and reduces appetite after food ingestion, and it is the basis for drugs against type-2 diabetes and obesity. Drugs targeting L- and other enteroendocrine cells are under development, with the aim to mimic endocrine effects of gastric bypass surgery, but they are difficult to develop without human L-cell models. Human ileal organoids, engineered by CRISPR-Cas9, express the fluorescent protein Venus in the proglucagon locus, enabling maintenance of live, identifiable human L-cells in culture. Fluorescence-activated cell sorting (FACS)-purified organoid-derived L-cells, analyzed by RNA sequencing (RNA-seq), express hormones, receptors, and ion channels, largely typical of their murine counterparts. L-cells are electrically active and exhibit membrane depolarization and calcium elevations in response to G-protein-coupled receptor ligands. Organoids secrete hormones in response to glucose and other stimuli. The ability to label and maintain human L-cells in organoid culture opens avenues to explore L-cell function and develop drugs targeting the human enteroendocrine system.
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Affiliation(s)
- Deborah A Goldspink
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Van B Lu
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Emily L Miedzybrodzka
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Christopher A Smith
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Rachel E Foreman
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Lawrence J Billing
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Richard G Kay
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Frank Reimann
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK.
| | - Fiona M Gribble
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK.
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9
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Reimann F, Diakogiannaki E, Hodge D, Gribble FM. Cellular mechanisms governing glucose-dependent insulinotropic polypeptide secretion. Peptides 2020; 125:170206. [PMID: 31756367 DOI: 10.1016/j.peptides.2019.170206] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 02/01/2023]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a gut hormone secreted from the upper small intestine, which plays an important physiological role in the control of glucose metabolism through its incretin action to enhance glucose-dependent insulin secretion. GIP has also been implicated in postprandial lipid homeostasis. GIP is secreted from enteroendocrine K-cells residing in the intestinal epithelium. K-cells sense a variety of components found in the gut lumen following food consumption, resulting in an increase in plasma GIP signal dependent on the nature and quantity of ingested nutrients. We review the evidence for an important role of sodium-coupled glucose uptake through SGLT1 for carbohydrate sensing, of free-fatty acid receptors FFAR1/FFAR4 and the monoacyl-glycerol sensing receptor GPR119 for lipid detection, of the calcium-sensing receptor CASR and GPR142 for protein sensing, and additional modulation by neurotransmitters such as somatostatin and galanin. These pathways have been identified through combinations of in vivo, in vitro and molecular approaches.
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Affiliation(s)
- Frank Reimann
- Wellcome Trust/MRC Institute of Metabolic Science (IMS), University of Cambridge, United Kingdom.
| | - Eleftheria Diakogiannaki
- Wellcome Trust/MRC Institute of Metabolic Science (IMS), University of Cambridge, United Kingdom
| | - Daryl Hodge
- Wellcome Trust/MRC Institute of Metabolic Science (IMS), University of Cambridge, United Kingdom
| | - Fiona M Gribble
- Wellcome Trust/MRC Institute of Metabolic Science (IMS), University of Cambridge, United Kingdom.
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10
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Abstract
Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.
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11
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Holst JJ, Albrechtsen NJW, Rosenkilde MM, Deacon CF. Physiology of the Incretin Hormones,
GIP
and
GLP
‐1—Regulation of Release and Posttranslational Modifications. Compr Physiol 2019; 9:1339-1381. [DOI: 10.1002/cphy.c180013] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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12
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Smith NK, Hackett TA, Galli A, Flynn CR. GLP-1: Molecular mechanisms and outcomes of a complex signaling system. Neurochem Int 2019; 128:94-105. [PMID: 31002893 PMCID: PMC7081944 DOI: 10.1016/j.neuint.2019.04.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/26/2019] [Accepted: 04/15/2019] [Indexed: 12/15/2022]
Abstract
Meal ingestion provokes the release of hormones and transmitters, which in turn regulate energy homeostasis and feeding behavior. One such hormone, glucagon-like peptide-1 (GLP-1), has received significant attention in the treatment of obesity and diabetes due to its potent incretin effect. In addition to the peripheral actions of GLP-1, this hormone is able to alter behavior through the modulation of multiple neural circuits. Recent work that focused on elucidating the mechanisms and outcomes of GLP-1 neuromodulation led to the discovery of an impressive array of GLP-1 actions. Here, we summarize the many levels at which the GLP-1 signal adapts to different systems, with the goal being to provide a background against which to guide future research.
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Affiliation(s)
- Nicholas K Smith
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Troy A Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
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Abstract
Gut hormones have many key roles in the control of metabolism, as they target diverse tissues involved in the control of intestinal function, insulin secretion, nutrient assimilation and food intake. Produced by scattered cells found along the length of the intestinal epithelium, gut hormones generate signals related to the rate of nutrient absorption, the composition of the luminal milieu and the integrity of the epithelial barrier. Gut hormones already form the basis for existing and developing therapeutics for type 2 diabetes mellitus and obesity, exemplified by the licensed glucagon-like peptide 1 (GLP1) mimetics and dipeptidyl peptidase inhibitors that enhance GLP1 receptor activation. Modulating the release of the endogenous stores of GLP1 and other gut hormones is thought to be a promising strategy to mimic bariatric surgery with its multifaceted beneficial effects on food intake, body weight and blood glucose levels. This Review focuses on the molecular mechanisms underlying the modulation of gut hormone release by food ingestion, obesity and the gut microbiota. Depending on the nature of the stimulus, release of gut hormones involves recruitment of a variety of signalling pathways, including G protein-coupled receptors, nutrient transporters and ion channels, which are targets for future therapeutics for diabetes mellitus and obesity.
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Affiliation(s)
- Fiona M Gribble
- Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Frank Reimann
- Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
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14
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Adriaenssens AE, Reimann F, Gribble FM. Distribution and Stimulus Secretion Coupling of Enteroendocrine Cells along the Intestinal Tract. Compr Physiol 2018; 8:1603-1638. [DOI: 10.1002/cphy.c170047] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Lu VB, Gribble FM, Reimann F. Free Fatty Acid Receptors in Enteroendocrine Cells. Endocrinology 2018; 159:2826-2835. [PMID: 29688303 DOI: 10.1210/en.2018-00261] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/17/2018] [Indexed: 02/02/2023]
Abstract
Free fatty acid receptors (FFAs) are highly enriched in enteroendocrine cells providing pathways to link dietary fats and microbially generated short-chain fatty acids (SCFAs) to the secretion of a variety of gut hormones. FFA1 and FFA4 are receptors for long-chain fatty acids that have been linked to the elevation of plasma gut hormones after fat ingestion. FFA2 and FFA3 are receptors for SCFA, which are generated at high concentrations by microbial fermentation of dietary fiber and have also been implicated in enhancement of gut hormone secretion. FFAs are candidate drug targets for increasing the secretion of intestinal hormones such as glucagon-like peptide-1 and peptide YY as potential new treatments for type 2 diabetes and obesity. This review will examine aspects of intestinal physiology and pharmacology related to the function of FFAs in enteroendocrine cells.
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Affiliation(s)
- Van B Lu
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Fiona M Gribble
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Frank Reimann
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
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Priyadarshini M, Kotlo KU, Dudeja PK, Layden BT. Role of Short Chain Fatty Acid Receptors in Intestinal Physiology and Pathophysiology. Compr Physiol 2018; 8:1091-1115. [PMID: 29978895 DOI: 10.1002/cphy.c170050] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nutrient sensing is a mechanism for organisms to sense their environment. In larger animals, including humans, the intestinal tract is a major site of nutrient sensing for the body, not surprisingly, as this is the central location where nutrients are absorbed. In the gut, bacterial fermentation results in generation of short chain fatty acids (SCFAs), a class of nutrients, which are sensed by specific membrane bound receptors, FFA2, FFA3, GPR109a, and Olfr78. These receptors are expressed uniquely throughout the gut and signal through distinct mechanisms. To date, the emerging data suggests a role of these receptors in normal and pathological conditions. The overall function of these receptors is to regulate aspects of intestinal motility, hormone secretion, maintenance of the epithelial barrier, and immune cell function. Besides in intestinal health, a prominent role of these receptors has emerged in modulation of inflammatory and immune responses during pathological conditions. Moreover, these receptors are being revealed to interact with the gut microbiota. This review article updates the current body of knowledge on SCFA sensing receptors in the gut and their roles in intestinal health and disease as well as in whole body energy homeostasis. © 2017 American Physiological Society. Compr Physiol 8:1091-1115, 2018.
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Affiliation(s)
- Medha Priyadarshini
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Illinois, USA
| | - Kumar U Kotlo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Illinois, USA
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Illinois, USA.,Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
| | - Brian T Layden
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Illinois, USA.,Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
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17
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Sebastiani G, Ceccarelli E, Castagna MG, Dotta F. G-protein-coupled receptors (GPCRs) in the treatment of diabetes: Current view and future perspectives. Best Pract Res Clin Endocrinol Metab 2018; 32:201-213. [PMID: 29678286 DOI: 10.1016/j.beem.2018.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
G-protein coupled receptors (GPCRs) represent the largest receptor family in the genome and are of great interest for the design of novel drugs in a wide variety of diseases including neurologic disorders, obesity and Type 2 diabetes mellitus. The latter is a chronic disease characterized by insulin resistance and impaired insulin secretion, affecting >400 million patients worldwide. Here we provide an overview on: a) The molecular basis of GPCR signalling and of its involvement in the regulation of insulin secretion and of glucose homeostasis; b) the role of GPCRs in type 2 diabetes pathophysiology and as therapeutic targets of current and future glucose-lowering drugs.
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Affiliation(s)
- Guido Sebastiani
- Department of Medicine, Surgery and Neurosciences, University of Siena, Italy; Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Elena Ceccarelli
- Department of Medicine, Surgery and Neurosciences, University of Siena, Italy
| | | | - Francesco Dotta
- Department of Medicine, Surgery and Neurosciences, University of Siena, Italy; Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy.
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18
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Gribble FM, Meek CL, Reimann F. Targeted intestinal delivery of incretin secretagogues-towards new diabetes and obesity therapies. Peptides 2018; 100:68-74. [PMID: 29412834 PMCID: PMC5805852 DOI: 10.1016/j.peptides.2017.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 11/16/2017] [Accepted: 11/20/2017] [Indexed: 12/11/2022]
Abstract
A new strategy under development for the treatment of type 2 diabetes and obesity is to mimic some of the effects of bariatric surgery by delivering food-related stimuli to the distal gastrointestinal tract where they should enhance the release of gut hormones such as glucagon-like peptide-1 (GLP-1) and peptideYY (PYY). Methods include inhibition of food digestion and absorption in the upper GI tract, or oral delivery of stimuli in capsules or pelleted form to protect them against gastric degradation. A variety of agents have been tested in humans using capsules, microcapsules or pellets, delivering nutrients, bile acids, fatty acids and bitter compounds. This review examines the outcomes of these different approaches and supporting evidence from intestinal perfusion studies.
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Affiliation(s)
- Fiona M Gribble
- Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Box 289, Hills Road, Cambridge, CB2 0QQ, United Kingdom; Department of Clinical Biochemistry, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, United Kingdom.
| | - Claire L Meek
- Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Box 289, Hills Road, Cambridge, CB2 0QQ, United Kingdom; Department of Clinical Biochemistry, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, United Kingdom
| | - Frank Reimann
- Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Addenbrooke's Hospital, Box 289, Hills Road, Cambridge, CB2 0QQ, United Kingdom; Department of Clinical Biochemistry, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, United Kingdom.
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19
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Worthington JJ, Reimann F, Gribble FM. Enteroendocrine cells-sensory sentinels of the intestinal environment and orchestrators of mucosal immunity. Mucosal Immunol 2018; 11:3-20. [PMID: 28853441 DOI: 10.1038/mi.2017.73] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 07/14/2017] [Indexed: 02/06/2023]
Abstract
The intestinal epithelium must balance efficient absorption of nutrients with partitioning commensals and pathogens from the bodies' largest immune system. If this crucial barrier fails, inappropriate immune responses can result in inflammatory bowel disease or chronic infection. Enteroendocrine cells represent 1% of this epithelium and have classically been studied for their detection of nutrients and release of peptide hormones to mediate digestion. Intriguingly, enteroendocrine cells are the key sensors of microbial metabolites, can release cytokines in response to pathogen associated molecules and peptide hormone receptors are expressed on numerous intestinal immune cells; thus enteroendocrine cells are uniquely equipped to be crucial and novel orchestrators of intestinal inflammation. In this review, we introduce enteroendocrine chemosensory roles, summarize studies correlating enteroendocrine perturbations with intestinal inflammation and describe the mechanistic interactions by which enteroendocrine and mucosal immune cells interact during disease; highlighting this immunoendocrine axis as a key aspect of innate immunity.
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Affiliation(s)
- J J Worthington
- Lancaster University, Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster, Lancashire, UK
| | - F Reimann
- University of Cambridge, Metabolic Research Laboratories, Wellcome Trust/MRC Institute of Metabolic Science & MRC Metabolic Diseases Unit, Addenbrooke's Hospital, Cambridge, UK
| | - F M Gribble
- University of Cambridge, Metabolic Research Laboratories, Wellcome Trust/MRC Institute of Metabolic Science & MRC Metabolic Diseases Unit, Addenbrooke's Hospital, Cambridge, UK
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20
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Im DS. FFA4 (GPR120) as a fatty acid sensor involved in appetite control, insulin sensitivity and inflammation regulation. Mol Aspects Med 2017; 64:92-108. [PMID: 28887275 DOI: 10.1016/j.mam.2017.09.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/03/2017] [Accepted: 09/03/2017] [Indexed: 12/19/2022]
Abstract
Unsaturated long-chain fatty acids have been suggested to be beneficial in the context of cardiovascular disorders based in epidemiologic studies conducted in Greenland and Mediterranean. DHA and EPA are omega-3 polyunsaturated fatty acids that are plentiful in fish oil, and oleic acid is an omega-9 monounsaturated fatty acid, rich in olive oil. Dietary intake of these unsaturated long-chain fatty acids have been associated with insulin sensitivity and weight loss, which contrasts with the impairment of insulin sensitivity and weight gain associated with high intakes of saturated long-chain fatty acids. The recent discovery that free fatty acid receptor 4 (FFA4, also known as GPR120) acts as a sensor for unsaturated long-chain fatty acids started to unveil the molecular mechanisms underlying the beneficial functions played by these unsaturated long-chain fatty acids in various physiological processes, which include the secretions of gastrointestinal peptide hormones and glucose homeostasis. In this review, the physiological roles and therapeutic significance of FFA4 in appetite control, insulin sensitization, and inflammation reduction are discussed in relation to obesity and type 2 diabetes from pharmacological viewpoints.
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Affiliation(s)
- Dong-Soon Im
- Molecular Inflammation Research Center for Aging Intervention (MRCA), College of Pharmacy, Pusan National University, Busan 46241, Republic of Korea.
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21
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Glass LL, Calero-Nieto FJ, Jawaid W, Larraufie P, Kay RG, Göttgens B, Reimann F, Gribble FM. Single-cell RNA-sequencing reveals a distinct population of proglucagon-expressing cells specific to the mouse upper small intestine. Mol Metab 2017; 6:1296-1303. [PMID: 29031728 PMCID: PMC5641633 DOI: 10.1016/j.molmet.2017.07.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/21/2017] [Accepted: 07/27/2017] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVES To identify sub-populations of intestinal preproglucagon-expressing (PPG) cells producing Glucagon-like Peptide-1, and their associated expression profiles of sensory receptors, thereby enabling the discovery of therapeutic strategies that target these cell populations for the treatment of diabetes and obesity. METHODS We performed single cell RNA sequencing of PPG-cells purified by flow cytometry from the upper small intestine of 3 GLU-Venus mice. Cells from 2 mice were sequenced at low depth, and from the third mouse at high depth. High quality sequencing data from 234 PPG-cells were used to identify clusters by tSNE analysis. qPCR was performed to compare the longitudinal and crypt/villus locations of cluster-specific genes. Immunofluorescence and mass spectrometry were used to confirm protein expression. RESULTS PPG-cells formed 3 major clusters: a group with typical characteristics of classical L-cells, including high expression of Gcg and Pyy (comprising 51% of all PPG-cells); a cell type overlapping with Gip-expressing K-cells (14%); and a unique cluster expressing Tph1 and Pzp that was predominantly located in proximal small intestine villi and co-produced 5-HT (35%). Expression of G-protein coupled receptors differed between clusters, suggesting the cell types are differentially regulated and would be differentially targetable. CONCLUSIONS Our findings support the emerging concept that many enteroendocrine cell populations are highly overlapping, with individual cells producing a range of peptides previously assigned to distinct cell types. Different receptor expression profiles across the clusters highlight potential drug targets to increase gut hormone secretion for the treatment of diabetes and obesity.
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Affiliation(s)
- Leslie L Glass
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Fernando J Calero-Nieto
- Wellcome Trust and MRC Cambridge Stem Cell Institute & Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0XY, UK
| | - Wajid Jawaid
- Wellcome Trust and MRC Cambridge Stem Cell Institute & Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0XY, UK
| | - Pierre Larraufie
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Richard G Kay
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Berthold Göttgens
- Wellcome Trust and MRC Cambridge Stem Cell Institute & Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0XY, UK
| | - Frank Reimann
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Fiona M Gribble
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
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22
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Signalling in the gut endocrine axis. Physiol Behav 2017; 176:183-188. [DOI: 10.1016/j.physbeh.2017.02.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/23/2017] [Accepted: 02/27/2017] [Indexed: 02/06/2023]
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