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Zhang L, Herzog H. Important role of NPY-Y4R signalling in the dual control of feeding and physical activity. Neuropeptides 2024; 105:102425. [PMID: 38554699 DOI: 10.1016/j.npep.2024.102425] [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: 01/17/2024] [Revised: 03/14/2024] [Accepted: 03/16/2024] [Indexed: 04/02/2024]
Abstract
The control of feeding and physical activity is tightly linked and coordinated. However the underlying mechanisms are unclear. One of the major regulatory systems of feeding behaviour involves neuropeptide Y (NPY) signalling, with the signalling mediated through NPY Y4 receptor also known to influence activity. Here we show that mice globally lacking the Npy4r (Npy4r-/-) in the absence of access to a running wheel behaved WT-like with regards to food intake, energy expenditure, respiratory exchange ratio and locomotion regardless of being fed on a chow or high fat diet. Interestingly however, when given the access to a running wheel, Npy4r-/- mice while having a comparable locomotor activity, showed significantly higher wheel-running activity than WT, again regardless of dietary conditions. This higher wheel-running activity in Npy4r-/-mice arose from an increased dark-phase running time rather than changes in number of running bouts or the running speed. Consistently, energy expenditure was higher in Npy4r-/- than WT mice. Importantly, food intake was reduced in Npy4r-/-mice under wheel access condition which was due to decreased feeding bouts rather than changes in meal size. Together, these findings demonstrate an important role of Npy4r signalling in the dual control of feeding and physical activity, particularly in the form of wheel-running activity.
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Affiliation(s)
- Lei Zhang
- St Vincent's Centre for Applied Medical Research, School of Clinical Medicine, UNSW Medicine and Health, UNSW SYDNEY, NSW 2052, Australia.
| | - Herbert Herzog
- St Vincent's Centre for Applied Medical Research, School of Clinical Medicine, UNSW Medicine and Health, UNSW SYDNEY, NSW 2052, Australia
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2
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Schüß C, Behr V, Beck-Sickinger AG. Illuminating the neuropeptide Y 4 receptor and its ligand pancreatic polypeptide from a structural, functional, and therapeutic perspective. Neuropeptides 2024; 105:102416. [PMID: 38430725 DOI: 10.1016/j.npep.2024.102416] [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: 12/20/2023] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/05/2024]
Abstract
The neuropeptide Y4 receptor (Y4R), a rhodopsin-like G protein-coupled receptor (GPCR) and the hormone pancreatic polypeptide (PP) are members of the neuropeptide Y family consisting of four receptors (Y1R, Y2R, Y4R, Y5R) and three highly homologous peptide ligands (neuropeptide Y, peptide YY, PP). In this family, the Y4R is of particular interest as it is the only subtype with high affinity to PP over NPY. The Y4R, as a mediator of PP signaling, has a pivotal role in appetite regulation and energy homeostasis, offering potential avenues for the treatment of metabolic disorders such as obesity. PP as anorexigenic peptide is released postprandial from the pancreas in response to food intake, induces satiety signals and contributes to hamper excessive food intake. Moreover, this system was also described to be associated with different types of cancer: overexpression of Y4R have been found in human adenocarcinoma cells, while elevated levels of PP are related to the development of pancreatic endocrine tumors. The pharmacological relevance of the Y4R advanced the search for potent and selective ligands for this receptor subtype, which will be significantly progressed through the elucidation of the active state PP-Y4R cryo-EM structure. This review summarizes the development of novel PP-derived ligands, like Obinepitide as dual Y2R/Y4R agonist in clinical trials or UR-AK86c as small hexapeptide agonist with picomolar affinity, as well as the first allosteric modulators that selectively target the Y4R, e.g. VU0506013 as potent Y4R positive allosteric modulator or (S)-VU0637120 as allosteric antagonist. Here, we provide valuable insights into the complex physiological functions of the Y4R and PP and the pharmacological relevance of the system in appetite regulation to open up new avenues for the development of tool compounds for targeted therapies with potential applications in metabolic disorders.
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Affiliation(s)
- Corinna Schüß
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Germany.
| | - Victoria Behr
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Germany
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3
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Perez-Frances M, van Gurp L, Abate MV, Cigliola V, Furuyama K, Bru-Tari E, Oropeza D, Carreaux T, Fujitani Y, Thorel F, Herrera PL. Pancreatic Ppy-expressing γ-cells display mixed phenotypic traits and the adaptive plasticity to engage insulin production. Nat Commun 2021; 12:4458. [PMID: 34294685 PMCID: PMC8298494 DOI: 10.1038/s41467-021-24788-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 07/08/2021] [Indexed: 02/06/2023] Open
Abstract
The cellular identity of pancreatic polypeptide (Ppy)-expressing γ-cells, one of the rarest pancreatic islet cell-type, remains elusive. Within islets, glucagon and somatostatin, released respectively from α- and δ-cells, modulate the secretion of insulin by β-cells. Dysregulation of insulin production raises blood glucose levels, leading to diabetes onset. Here, we present the genetic signature of human and mouse γ-cells. Using different approaches, we identified a set of genes and pathways defining their functional identity. We found that the γ-cell population is heterogeneous, with subsets of cells producing another hormone in addition to Ppy. These bihormonal cells share identity markers typical of the other islet cell-types. In mice, Ppy gene inactivation or conditional γ-cell ablation did not alter glycemia nor body weight. Interestingly, upon β-cell injury induction, γ-cells exhibited gene expression changes and some of them engaged insulin production, like α- and δ-cells. In conclusion, we provide a comprehensive characterization of γ-cells and highlight their plasticity and therapeutic potential.
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Affiliation(s)
- Marta Perez-Frances
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Léon van Gurp
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Maria Valentina Abate
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Valentina Cigliola
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
- Regeneration Next, Duke University, Durham, NC, USA
| | - Kenichiro Furuyama
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Eva Bru-Tari
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Daniel Oropeza
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Taïna Carreaux
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Yoshio Fujitani
- Lab. of Developmental Biology & Metabolism, Institute for Molecular & Cellular Regulation, Gunma University, Maebashi, Gunma, Japan
| | - Fabrizio Thorel
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pedro L Herrera
- Department of Genetic Medicine & Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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Gershkovich MM, Groß VE, Vu O, Schoeder CT, Meiler J, Prömel S, Kaiser A. Structural Perspective on Ancient Neuropeptide Y-like System reveals Hallmark Features for Peptide Recognition and Receptor Activation. J Mol Biol 2021; 433:166992. [PMID: 33865871 PMCID: PMC8380825 DOI: 10.1016/j.jmb.2021.166992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/22/2021] [Accepted: 04/01/2021] [Indexed: 11/30/2022]
Abstract
The neuropeptide Y (NPY) family is a peptide-activated G protein-coupled receptor system conserved across all bilaterians, and is involved in food intake, learning, and behavior. We hypothesized that comparing the NPY system in evolutionarily ancient organisms can reveal structural determinants of peptide recognition and receptor activation conserved in evolution. To test this hypothesis, we investigated the homologous FLP/NPR system of the protostome C.elegans. For three prototypic peptide-receptor complexes representing different ligand types, we integrate extensive functional data into structural models of the receptors. Common features include acidic patches in the extracellular loops (ECLs) of the receptors that cooperatively 'draw' the peptide into the binding pocket, which was functionally validated in vivo. A structurally conserved glutamate in the ECL2 anchors the peptides by a conserved salt bridge to the arginine of the RFamide motif. Beyond this conserved interaction, peptide binding show variability enabled by receptor-specific interactions. The family-conserved residue Q3.32 is a key player for peptide binding and receptor activation. Altered interaction patterns at Q3.32 may drastically increase the efficacy to activate the receptor.
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Affiliation(s)
- Miron Mikhailowitsch Gershkovich
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany; Department of Chemistry, Center for Structural Biology, Vanderbilt University, 465 21st Ave South, BIOSCI/MRBIII, Nashville, TN 37235, USA
| | - Victoria Elisabeth Groß
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Oanh Vu
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, 465 21st Ave South, BIOSCI/MRBIII, Nashville, TN 37235, USA
| | - Clara Tabea Schoeder
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, 465 21st Ave South, BIOSCI/MRBIII, Nashville, TN 37235, USA; Institute for Drug Discovery, Medical Faculty, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Jens Meiler
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, 465 21st Ave South, BIOSCI/MRBIII, Nashville, TN 37235, USA; Institute for Drug Discovery, Medical Faculty, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Simone Prömel
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany
| | - Anette Kaiser
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany.
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Loh K, Herzog H, Shi YC. Regulation of energy homeostasis by the NPY system. Trends Endocrinol Metab 2015; 26:125-35. [PMID: 25662369 DOI: 10.1016/j.tem.2015.01.003] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/11/2015] [Accepted: 01/12/2015] [Indexed: 01/01/2023]
Abstract
Obesity develops when energy intake exceeds energy expenditure over time. Numerous neurotransmitters, hormones, and factors have been implicated to coordinately control energy homeostasis, centrally and peripherally. However, the neuropeptide Y (NPY) system has emerged as the one with the most critical functions in this process. While NPY centrally promotes feeding and reduces energy expenditure, peptide YY (PYY) and pancreatic polypeptide (PP), the other family members, mediate satiety. Importantly, recent research has uncovered additional functions for these peptides that go beyond the simple feeding/satiety circuits and indicate a more extensive function in controlling energy homeostasis. In this review, we will discuss the actions of the NPY system in the regulation of energy balance, with a particular focus on energy expenditure.
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Affiliation(s)
- Kim Loh
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, 2010, Australia; Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - Herbert Herzog
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, 2010, Australia; Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia.
| | - Yan-Chuan Shi
- Neuroscience Division, Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, 2010, Australia; Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia.
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6
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Wang J, Xiao R. G protein-coupled receptors in energy homeostasis. SCIENCE CHINA-LIFE SCIENCES 2014; 57:672-80. [PMID: 24969703 DOI: 10.1007/s11427-014-4694-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/13/2014] [Indexed: 12/25/2022]
Abstract
G-protein coupled receptors (GPCRs) compromise the largest membrane protein superfamily which play vital roles in physiological and pathophysiological processes including energy homeostasis. Moreover, they also represent the up-to-date most successful drug target. The gut hormone GPCRs, such as glucagon receptor and GLP-1 receptor, have been intensively studied for their roles in metabolism and respective drugs have developed for the treatment of metabolic diseases such as type 2 diabetes (T2D). Along with the advances of biomedical research, more GPCRs have been found to play important roles in the regulation of energy homeostasis from nutrient sensing, appetite control to glucose and fatty acid metabolism with various mechanisms. The investigation of their biological functions will not only improve our understanding of how our body keeps the balance of energy intake and expenditure, but also highlight the possible drug targets for the treatment of metabolic diseases. The present review summarizes GPCRs involved in the energy control with special emphasis on their pathophysiological roles in metabolic diseases and hopefully triggers more intensive and systematic investigations in the field so that a comprehensive network control of energy homeostasis will be revealed, and better drugs will be developed in the foreseeable future.
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Affiliation(s)
- Jue Wang
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China,
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7
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Teubner BJ, Bartness TJ. PYY(3-36) into the arcuate nucleus inhibits food deprivation-induced increases in food hoarding and intake. Peptides 2013; 47:20-8. [PMID: 23816798 PMCID: PMC3759582 DOI: 10.1016/j.peptides.2013.05.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 05/11/2013] [Accepted: 05/13/2013] [Indexed: 12/17/2022]
Abstract
Central administration of neuropeptide Y (NPY) increases food intake in laboratory rats and mice, as well as food foraging and hoarding in Siberian hamsters. The NPY-Y1 and Y5 receptors (Rs) within the hypothalamus appear sufficient to account for these increases in ingestive behaviors. Stimulation of NPY-Y2Rs in the Arcuate nucleus (Arc) has an anorexigenic effect as shown by central or peripheral administration of its natural ligand peptide YY (3-36) and pharmacological NPY-Y2R antagonism by BIIE0246 increases food intake. Both effects on food intake by NPY-Y2R agonism and antagonism are relatively short-lived lasting ∼4h. The role of NPY-Y2Rs in appetitive ingestive behaviors (food foraging/hoarding) is untested, however. Therefore, Siberians hamsters, a natural food hoarder, were housed in a semi-natural burrow/foraging system that had (a) foraging requirement (10 revolutions/pellet), no free food (true foraging group), (b) no running wheel access, free food (general malaise control) or (c) running wheel access, free food (exercise control). We microinjected BIIE0246 (antagonist) and PYY(3-36) (agonist) into the Arc to test the role of NPY-Y2Rs there on ingestive behaviors. Food foraging, hoarding, and intake were not affected by Arc BIIE0246 microinjection in fed hamsters 1, 2, 4, and 24h post injection. Stimulation of NPY-Y2Rs by PYY(3-36) inhibited food intake at 0-1 and 1-2h and food hoarding at 1-2h without causing general malaise or affecting foraging. Collectively, these results implicate a sufficiency, but not necessity, of the Arc NPY-Y2R in the inhibition of food intake and food hoarding by Siberian hamsters.
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Affiliation(s)
- Brett J.W. Teubner
- Department of Biology and Obesity Reversal Center, Georgia State University, Atlanta, GA 30302-4010 USA
| | - Timothy J. Bartness
- Department of Biology and Obesity Reversal Center, Georgia State University, Atlanta, GA 30302-4010 USA
- To whom all correspondence should be addressed. Dr. Timothy J. Bartness, Department of Biology, 24 Peachtree Center Ave. NE, Georgia State University, Atlanta, GA 30302-4010, Phone: (404) 413-5334, FAX: (404) 413-5301,
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8
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The neuropeptide Y system: Pathophysiological and therapeutic implications in obesity and cancer. Pharmacol Ther 2011; 131:91-113. [DOI: 10.1016/j.pharmthera.2011.03.011] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Accepted: 03/07/2011] [Indexed: 12/28/2022]
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9
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Zhang L, Riepler SJ, Turner N, Enriquez RF, Lee ICJ, Baldock PA, Herzog H, Sainsbury A. Y2 and Y4 receptor signaling synergistically act on energy expenditure and physical activity. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1618-28. [DOI: 10.1152/ajpregu.00345.2010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neuropeptide Y receptors are critical regulators of energy homeostasis and are well known for their powerful influence on feeding, but their roles in other important aspects of energy homeostasis, such as energy expenditure and their functional interactions in these processes, are largely unknown. Here we show that mice lacking both Y2 and Y4 receptors exhibited a reduction in adiposity, more prominent in intra-abdominal vs. subcutaneous fat, and an increase in lean mass as determined by dual-energy X-ray absorptiometry. These changes were more pronounced than those seen in mice with Y2 or Y4 receptor single deletion, demonstrating the important roles and synergy of Y2 and Y4 signaling in the regulation of body composition. These changes in body composition occurred without significant changes in food intake, but energy expenditure and physical activity were significantly increased in Y4−/− and particularly in Y2−/−Y4−/− but not in Y2−/− mice, suggesting a critical role of Y4 signaling and synergistic interactions with Y2 signaling in the regulation of energy expenditure and physical activity. Y2−/− and Y4−/− mice also exhibited a decrease in respiratory exchange ratio with no further synergistic decrease in Y2−/−Y4−/− mice, suggesting that Y2 and Y4 signaling each play important and independent roles in the regulation of substrate utilization. The synergy between Y2 and Y4 signaling in regulating fat mass may be related to differences in mitochondrial oxidative capacity, since Y2−/−Y4−/− but not Y2−/− or Y4−/− mice showed significant increases in muscle protein levels of peroxisome proliferator-activated receptor (PPAR)γ coactivator (PGC)-1α, and mitochondrial respiratory chain complexes I and III. Taken together, this work demonstrates the critical roles of Y2 and Y4 receptors in the regulation of body composition and energy metabolism, highlighting dual antagonism of Y2 and Y4 receptors as a potentially effective anti-obesity treatment.
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Affiliation(s)
| | | | - Nigel Turner
- Diabetes and Obesity Program, Garvan Institute of Medical Research, St. Vincent's Hospital, Darlinghurst, Sydney, Australia
- St. Vincent's Hospital Clinical School,
| | | | | | | | - Herbert Herzog
- Neuroscience Research Program and
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Amanda Sainsbury
- Neuroscience Research Program and
- School of Medical Sciences, and
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10
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Yarandi SS, Hebbar G, Sauer CG, Cole CR, Ziegler TR. Diverse roles of leptin in the gastrointestinal tract: modulation of motility, absorption, growth, and inflammation. Nutrition 2010; 27:269-75. [PMID: 20947298 DOI: 10.1016/j.nut.2010.07.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/08/2010] [Accepted: 07/09/2010] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Leptin was discovered in 1994 as a hormone produced by adipose tissue with a modulatory effect on feeding behavior and weight control. Recently, the stomach has been identified as an important source of leptin and growing evidence has shown diverse functions for leptin in the gastrointestinal tract. METHODS Using leptin as a keyword in PubMed, more than 17 000 articles were identified, of which more than 500 articles were related to the role of leptin in the gastrointestinal tract. Available abstracts were reviewed and more than 200 original articles were reviewed in detail. RESULTS The available literature demonstrated that leptin can modulate several important functions of the gastrointestinal tract. Leptin interacts with the vagus nerve and cholecystokinin to delay gastric emptying and has a complex effect on motility of the small bowel. Leptin modulates absorption of macronutrients in the gastrointestinal tract differentially in physiologic and pathologic states. In physiologic states, exogenous leptin has been shown to decrease carbohydrate absorption and to increase the absorption of small peptides by the PepT1 di-/tripeptide transporter. In certain pathologic states, leptin has been shown to increase absorption of carbohydrates, proteins, and fat. Leptin has been shown to be upregulated in the colonic mucosa in patients with inflammatory bowel disease. Leptin stimulates gut mucosal cell proliferation and inhibits apoptosis. These functions have led to speculation about the role of leptin in tumorigenesis in the gastrointestinal tract, which is complicated by the multiple immunoregulatory effects of leptin. CONCLUSION Leptin is an important modulator of major aspects of gastrointestinal tract functions, independent of its more well-described roles in appetite regulation and obesity.
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Affiliation(s)
- Shadi S Yarandi
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University, Atlanta, Georgia, USA
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11
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Lee NJ, Allison S, Enriquez RF, Sainsbury A, Herzog H, Baldock PA. Y2 and Y4 Receptor Signalling Attenuates the Skeletal Response of Central NPY. J Mol Neurosci 2010; 43:123-31. [DOI: 10.1007/s12031-010-9423-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 07/01/2010] [Indexed: 12/30/2022]
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12
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Kirchner H, Tong J, Tschöp MH, Pfluger PT. Ghrelin and PYY in the regulation of energy balance and metabolism: lessons from mouse mutants. Am J Physiol Endocrinol Metab 2010; 298:E909-19. [PMID: 20179246 DOI: 10.1152/ajpendo.00191.2009] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Effective control of body weight and energy homeostasis requires stringent regulation of caloric intake and energy expenditure. Gut-brain interactions comprise a central axis for the control of energy homeostasis by integrating the intake of nutrients with an effective utilization of ingested calories either by storage or by expenditure as cellular fuel. Ghrelin, a stomach-derived peptide, is the only known circulating orexigenic hormone. It is acylated with a medium-chain fatty acid by the enzyme ghrelin O-acetyltransferase (GOAT) and displays a broad range of activity, from central control of food intake to peripheral functions such as gastric emptying and insulin secretion. PYY, a peptide produced by L cells of the small intestine and rectum, has been shown to inhibit gut motility and is proposed to stimulate a powerful central satiety response. In recent years, pharmacological studies in animals and clinical studies in humans have contributed to our knowledge of principal ghrelin and PYY actions. However, valuable findings from studies using ghrelin-deficient mice, ghrelin receptor [growth hormone secretagogue receptor-1a (GHSR1a)]-deficient mice, double-knockout mice (for ghrelin and GHSR), and GOAT-deficient or -overexpressor mice, as well as mice deficient for PYY or neuropeptide Y receptors have allowed better definition of the actual physiological functions of ghrelin and PYY. This review summarizes findings from mutant mouse studies with emphasis on respective gene knockout and transgenic animals and describes how these studies contribute to the current understanding of how endogenous ghrelin and PYY as two major representatives of endocrine gut-brain communications may regulate energy and glucose homeostasis.
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Affiliation(s)
- Henriette Kirchner
- Obesity Research Centre, Department of Internal Medicine, University of Cincinnati College of Medicine, 2170 E. Galbraith Rd., Cincinnati, OH 45237, USA
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Kuphal KE, Solway B, Pedrazzini T, Taylor BK. Y1 receptor knockout increases nociception and prevents the anti-allodynic actions of NPY. Nutrition 2009; 24:885-91. [PMID: 18725085 DOI: 10.1016/j.nut.2008.06.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 06/13/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Recent pharmacologic studies in our laboratory have suggested that the spinal neuropeptide Y (NPY) Y1 receptor contributes to pain inhibition and to the analgesic effects of NPY. To rule out off-target effects, the present study used Y1-receptor-deficient (-/-) mice to further explore the contribution of Y1 receptors to pain modulation. METHODS AND RESULTS Y1(-/-) mice exhibited reduced latency in the hotplate test of acute pain and a longer-lasting heat allodynia in the complete Freund's adjuvant (CFA) model of inflammatory pain. Y1 deletion did not change CFA-induced inflammation. Upon targeting the spinal NPY systems with intrathecal drug delivery, NPY reduced tactile and heat allodynia in the CFA model and the partial sciatic nerve ligation model of neuropathic pain. Importantly, we show for the first time that NPY does not exert these anti-allodynic effects in Y1(-/-) mice. Furthermore, in nerve-injured CD1 mice, concomitant injection of the potent Y1 antagonist BIBO3304 prevented the anti-allodynic actions of NPY. Neither NPY nor BIBO3304 altered performance on the Rotorod test, arguing against an indirect effect of motor function. CONCLUSION The Y1 receptor contributes to pain inhibition and to the analgesic effects of NPY.
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Affiliation(s)
- K E Kuphal
- Division of Pharmacology, University of Missouri-Kansas City, Kansas City, Missouri, USA
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Fetissov SO, Hamze Sinno M, Coquerel Q, Do Rego JC, Coëffier M, Gilbert D, Hökfelt T, Déchelotte P. Emerging role of autoantibodies against appetite-regulating neuropeptides in eating disorders. Nutrition 2008; 24:854-9. [DOI: 10.1016/j.nut.2008.06.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Accepted: 06/15/2008] [Indexed: 12/17/2022]
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