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Amato A, Baldassano S, Caldara GF, Mulè F. Pancreatic polypeptide stimulates mouse gastric motor activity through peripheral neural mechanisms. Neurogastroenterol Motil 2017; 29. [PMID: 27381051 DOI: 10.1111/nmo.12901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 06/10/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Pancreatic polypeptide (PP) is supposed to be one of the major endogenous agonists of the neuropeptide Y4 receptor. Pancreatic polypeptide can influence gastrointestinal motility, acting mainly through vagal mechanisms, but whether PP acts directly on the stomach has not been explored yet. The aims of this study were to investigate the effects of PP on mouse gastric emptying, on spontaneous tone of whole stomach in vitro and to examine the mechanism of action. METHODS Gastric emptying was measured by red phenol method after i.p. PP administration (1-3 nmol per mouse). Responses induced by PP (1-300 mmol L-1 ) on gastric endoluminal pressure were analyzed in vitro in the presence of different drugs. Gastric genic expression of Y4 receptor was verified by RT-PCR. KEY RESULTS Pancreatic polypeptide dose-dependently increased non-nutrient liquid gastric emptying rate. In vitro, PP produced a concentration-dependent contraction that was abolished by tetrodotoxin, a neural blocker of Na+ voltage-dependent channels. The contractile response was significantly reduced by atropine, a muscarinic receptor antagonist, and by SR48968, an NK2 receptor antagonist, while it was potentiated by neostigmine, an inhibitor of acetylcholinesterase. The joint application of atropine and SR48968 fully abolished PP contractile effect. Reverse transcriptase-polymerase chain reaction analysis revealed the presence of Y4 receptor mRNA in mouse stomach with a greater expression in antrum than in fundus. CONCLUSIONS & INFERENCES The present findings demonstrate that exogenous PP stimulates mouse gastric motor activity, by acting directly on the stomach. This effect appears due to the activation of enteric excitatory neurons releasing acetylcholine and tachykinins.
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Affiliation(s)
- A Amato
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - S Baldassano
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - G F Caldara
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - F Mulè
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
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52
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Lakkireddy HR, Urmann M, Besenius M, Werner U, Haack T, Brun P, Alié J, Illel B, Hortala L, Vogel R, Bazile D. Oral delivery of diabetes peptides - Comparing standard formulations incorporating functional excipients and nanotechnologies in the translational context. Adv Drug Deliv Rev 2016; 106:196-222. [PMID: 26964477 DOI: 10.1016/j.addr.2016.02.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/23/2016] [Accepted: 02/28/2016] [Indexed: 12/12/2022]
Abstract
While some orally delivered diabetes peptides are moving to late development with standard formulations incorporating functional excipients, the demonstration of the value of nanotechnology in clinic is still at an early stage. The goal of this review is to compare these two drug delivery approaches from a physico-chemical and a biopharmaceutical standpoint in an attempt to define how nanotechnology-based products can be differentiated from standard oral dosage forms for oral bioavailability of diabetes peptides. Points to consider in a translational approach are outlined to seize the opportunities offered by a better understanding of both the intestinal barrier and of nano-carriers designed for oral delivery.
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Affiliation(s)
- Harivardhan Reddy Lakkireddy
- Drug Delivery Technologies and Innovation, Pharmaceutical Sciences Operations, Lead Generation and Candidate Realization, Sanofi Research and Development, Vitry-sur-Seine, France
| | - Matthias Urmann
- Diabetes Division, Sanofi Research and Development, Frankfurt, Germany
| | - Melissa Besenius
- Diabetes Division, Sanofi Research and Development, Frankfurt, Germany
| | - Ulrich Werner
- Diabetes Division, Sanofi Research and Development, Frankfurt, Germany
| | - Torsten Haack
- Diabetes Division, Sanofi Research and Development, Frankfurt, Germany
| | - Priscilla Brun
- Disposition Safety and Animal Research, Sanofi Research and Development, Montpellier, France
| | - Jean Alié
- Analytical Sciences, Lead Generation and Candidate Realization, Sanofi Research and Development, Montpellier, France
| | - Brigitte Illel
- Pharmaceutical Sciences Operations, Lead Generation and Candidate Realization, Sanofi Research and Development, Montpellier, France
| | - Laurent Hortala
- Pharmaceutical Sciences Operations, Lead Generation and Candidate Realization, Sanofi Research and Development, Montpellier, France
| | - Rachel Vogel
- Pharmaceutical Sciences Operations, Lead Generation and Candidate Realization, Sanofi Research and Development, Montpellier, France
| | - Didier Bazile
- Drug Delivery Technologies and Innovation, Pharmaceutical Sciences Operations, Lead Generation and Candidate Realization, Sanofi Research and Development, Vitry-sur-Seine, France.
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53
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He C, Zhang J, Gao S, Meng F, Bu G, Li J, Wang Y. Molecular characterization of three NPY receptors (Y2, Y5 and Y7) in chickens: Gene structure, tissue expression, promoter identification, and functional analysis. Gen Comp Endocrinol 2016; 236:24-34. [PMID: 27142335 DOI: 10.1016/j.ygcen.2016.04.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/18/2016] [Accepted: 04/22/2016] [Indexed: 02/02/2023]
Abstract
Six neuropeptide Y (NPY) receptors are suggested to mediate the biological actions of NPY, peptide YY (PYY), and pancreatic polypeptide (PP), such as food intake in birds, however, information regarding the structure and signaling of avian NPY receptors are rather limited. In this study, we investigated the gene structure, tissue expression and signaling property of three NPY receptors (cY2, cY5 and cY7) in chickens. The results showed that 1) cY2, cY5 and cY7 contain novel non-coding exons upstream of their start codon and alternative mRNA splicing in their 5'-UTR results in the formation of multiple transcript variants; 2) cY2, cY5 and cY7 transcripts were detected to be widely expressed in adult chicken tissues including various brain regions by RT-PCR, and their expression is controlled by a promoter(s) near exon 1, which display promoter activity in DF-1 cells as demonstrated by Dual-luciferase reporter assay; 3) cY2, cY5 and cY7 expressed in HEK293 cells were preferentially (or potently) activated by cNPY1-36 and cPYY1-37, but not by cPP1-36, and their activation led to the inhibition of cAMP/PKA signaling pathway and activation of MAPK/ERK signaling pathway, monitored by the cell-based luciferase reporter systems or western blots, indicating that the three NPY receptors are functional and capable of transmitting signals effectively. On the whole, our data establishes a molecular basis to elucidate the actions of three functional NPY receptors (cY2, cY5 and cY7) and their ligands in birds, which helps to uncover the conserved roles of these ligand-receptor pairs in vertebrates.
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Affiliation(s)
- Chen He
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Jiannan Zhang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Shunyu Gao
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China; College of Chemistry and Life Sciences, Chuxiong Normal University, Chuxiong 675000, PR China
| | - Fengyan Meng
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Guixian Bu
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Juan Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Yajun Wang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
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Massironi S, Zilli A, Cavalcoli F, Conte D, Peracchi M. Chromogranin A and other enteroendocrine markers in inflammatory bowel disease. Neuropeptides 2016; 58:127-34. [PMID: 26804239 DOI: 10.1016/j.npep.2016.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/10/2016] [Accepted: 01/10/2016] [Indexed: 02/08/2023]
Abstract
Changes in the distribution and products of enteroendocrine cells may play a role in immune activation and regulation of gut inflammation. This review aims at critically evaluating the main enteroendocrine markers in inflammatory bowel diseases (IBD). A narrative review was performed by searching inflammatory bowel diseases and enteroendocrine biomarkers in PubMed. Relevant modifications of some enteroendocrine markers, such as Chromogranin A, and their correlation with disease activity have been reported in patients with inflammatory bowel diseases. Even if data about neuroendocrine markers are sometimes contrasting, they may be potentially useful for the diagnosis and clinical management of these patients.
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Affiliation(s)
- Sara Massironi
- Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy.
| | - Alessandra Zilli
- Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; Postgraduate School of Gastroenterology, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy.
| | - Federica Cavalcoli
- Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; Postgraduate School of Gastroenterology, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy.
| | - Dario Conte
- Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; Postgraduate School of Gastroenterology, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy.
| | - Maddalena Peracchi
- Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; Postgraduate School of Gastroenterology, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy.
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55
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Hettiarachchi P, Wickremasinghe AR, Frost GS, Deen KI, Pathirana AA, Murphy KG, Jayaratne SD. Resection of the large bowel suppresses hunger and food intake and modulates gastrointestinal fermentation. Obesity (Silver Spring) 2016; 24:1723-30. [PMID: 27460713 DOI: 10.1002/oby.21550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/15/2016] [Accepted: 04/19/2016] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To assess appetite and gut hormone levels in patients following partial (PR) or total resection (TR) of the large bowel. METHODS A comparative cross sectional study was carried out with healthy controls (n = 99) and patients who had undergone PR (n = 64) or TR (n = 12) of the large bowel. Participants consumed a standard (720 kcal) breakfast meal at 0830 (t = 0) h followed by lactulose (15 g) and a buffet lunch (t = 210 min). Participants rated the subjective feelings of hunger at t = -30, 0, 30, 60, 120, and 180 min. Breath hydrogen (BH) concentrations were also evaluated. In a matched subset (11 controls, 11 PR and 9 TR patients) PYY and GLP-1 concentrations were measured following breakfast. The primary outcome measure was appetite, as measured using visual analogue scales and the buffet lunch. The secondary outcome was BH concentrations following a test meal. RESULTS PR and TR participants had lower hunger and energy intake at the buffet lunch meal compared to controls. PR subjects had higher BH concentrations compared to controls and TR subjects. BH levels correlated with circulating GLP-1 levels at specific time points. CONCLUSIONS PR or TR of the large bowel reduced feelings of hunger and energy intake, and PR increased gastrointestinal fermentation.
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Affiliation(s)
- Priyadarshika Hettiarachchi
- Department of Physiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | | | - Gary S Frost
- Nutrition and Dietetic Research Group, Department of Medicine, Imperial College, London, UK
| | - Kemal I Deen
- Department of Surgery, Faculty of Medicine, University of Kelaniya, Kelaniya, Sri Lanka
| | - Ajith A Pathirana
- Department of Surgery, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Kevin G Murphy
- Section of Investigative Medicine, Department of Medicine, Imperial College, London, UK
| | - SriLal D Jayaratne
- Department of Medicine, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
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56
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Sliwoski G, Schubert M, Stichel J, Weaver D, Beck-Sickinger AG, Meiler J. Discovery of Small-Molecule Modulators of the Human Y4 Receptor. PLoS One 2016; 11:e0157146. [PMID: 27294784 PMCID: PMC4905667 DOI: 10.1371/journal.pone.0157146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 05/25/2016] [Indexed: 12/11/2022] Open
Abstract
The human neuropeptide Y4 receptor (Y4R) and its native ligand, pancreatic polypeptide, are critically involved in the regulation of human metabolism by signaling satiety and regulating food intake, as well as increasing energy expenditure. Thus, this receptor represents a putative target for treatment of obesity. With respect to new approaches to treat complex metabolic disorders, especially in multi-receptor systems, small molecule allosteric modulators have been in the focus of research in the last years. However, no positive allosteric modulators or agonists of the Y4R have been described so far. In this study, small molecule compounds derived from the Niclosamide scaffold were identified by high-throughput screening to increase Y4R activity. Compounds were characterized for their potency and their effects at the human Y4R and as well as their selectivity towards Y1R, Y2R and Y5R. These compounds provide a structure-activity relationship profile around this common scaffold and lay the groundwork for hit-to-lead optimization and characterization of positive allosteric modulators of the Y4R.
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Affiliation(s)
- Gregory Sliwoski
- Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Leipzig University, Leipzig, Germany
- Center for Structural Biology, Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Mario Schubert
- Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Leipzig University, Leipzig, Germany
| | - Jan Stichel
- Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Leipzig University, Leipzig, Germany
| | - David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Annette G. Beck-Sickinger
- Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Leipzig University, Leipzig, Germany
- * E-mail: (JM); (ABS)
| | - Jens Meiler
- Center for Structural Biology, Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail: (JM); (ABS)
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57
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Latorre R, Sternini C, De Giorgio R, Greenwood-Van Meerveld B. Enteroendocrine cells: a review of their role in brain-gut communication. Neurogastroenterol Motil 2016; 28:620-30. [PMID: 26691223 PMCID: PMC4842178 DOI: 10.1111/nmo.12754] [Citation(s) in RCA: 203] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/17/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND Specialized endoderm-derived epithelial cells, that is, enteroendocrine cells (EECs), are widely distributed throughout the gastrointestinal (GI) tract. Enteroendocrine cells form the largest endocrine organ in the body and play a key role in the control of GI secretion and motility, the regulation of food intake, postprandial glucose levels and metabolism. EECs sense luminal content and release signaling molecules that can enter the circulation to act as classic hormones on distant targets, act locally on neighboring cells and on distinct neuronal pathways including enteric and extrinsic neurons. Recent studies have shed light on EEC sensory transmission by showing direct connections between EECs and the nervous system via axon-like processes that form a well-defined neuroepithelial circuits through which EECs can directly communicate with the neurons innervating the GI tract to initiate appropriate functional responses. PURPOSE This review will highlight the role played by the EECs in the complex and integrated sensory information responses, and discuss the new findings regarding EECs in the brain-gut axis bidirectional communication.
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Affiliation(s)
- R Latorre
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - C Sternini
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Departments of Medicine and Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - R De Giorgio
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - B Greenwood-Van Meerveld
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Physiology, Veterans Affairs Medical Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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58
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Henry KE, Kerwood DJ, Allis DG, Workinger JL, Bonaccorso RL, Holz GG, Roth CL, Zubieta J, Doyle RP. Solution Structure and Constrained Molecular Dynamics Study of Vitamin B12 Conjugates of the Anorectic Peptide PYY(3-36). ChemMedChem 2016; 11:1015-21. [PMID: 27027248 DOI: 10.1002/cmdc.201600073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 12/22/2022]
Abstract
Vitamin B12 -peptide conjugates have considerable therapeutic potential through improved pharmacokinetic and/or pharmacodynamic properties imparted on the peptide upon covalent attachment to vitamin B12 (B12 ). There remains a lack of structural studies investigating the effects of B12 conjugation on peptide secondary structure. Determining the solution structure of a B12 -peptide conjugate or conjugates and measuring functions of the conjugate(s) at the target peptide receptor may offer considerable insight concerning the future design of fully optimized conjugates. This methodology is especially useful in tandem with constrained molecular dynamics (MD) studies, such that predictions may be made about conjugates not yet synthesized. Focusing on two B12 conjugates of the anorectic peptide PYY(3-36), one of which was previously demonstrated to have improved food intake reduction compared with PYY(3-36), we performed NMR structural analyses and used the information to conduct MD simulations. The study provides rare structural insight into vitamin B12 conjugates and validates the fact that B12 can be conjugated to a peptide without markedly affecting peptide secondary structure.
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Affiliation(s)
- Kelly E Henry
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Deborah J Kerwood
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Damian G Allis
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Jayme L Workinger
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Ron L Bonaccorso
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - George G Holz
- Department of Medicine and Pharmacology, Institute for Human Performance, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY, 13210, USA
| | - Christian L Roth
- Department of Pediatrics, University of Washington, Division of Endocrinology and Diabetes, Seattle Children's Research Institute, Center for Integrative Brain Research, 1900 Ninth Avenue, Seattle, WA, 98101, USA
| | - Jon Zubieta
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Robert P Doyle
- Department of Chemistry, Center for Science and Technology, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA. .,Department of Medicine and Pharmacology, Institute for Human Performance, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY, 13210, USA.
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59
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Zhang G, Hasek LY, Lee BH, Hamaker BR. Gut feedback mechanisms and food intake: a physiological approach to slow carbohydrate bioavailability. Food Funct 2016; 6:1072-89. [PMID: 25686469 DOI: 10.1039/c4fo00803k] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glycemic carbohydrates in foods are an important macronutrient providing the biological fuel of glucose for a variety of physiological processes. A classification of glycemic carbohydrates into rapidly digestible carbohydrate (RDC) and slowly digestible carbohydrate (SDC) has been used to specify their nutritional quality related to glucose homeostasis that is essential to normal functioning of the brain and critical to life. Although there have been many studies and reviews on slowly digestible starch (SDS) and SDC, the mechanisms of their slow digestion and absorption were mostly investigated from the material side without considering the physiological processes of their in vivo digestion, absorption, and most importantly interactions with other food components and the gastrointestinal tract. In this article, the physiological processes modulating the bioavailability of carbohydrates, specifically the rate and extent of their digestion and absorption as well as the related locations, in a whole food context, will be discussed by focusing on the activities of the gastrointestinal tract including glycolytic enzymes and glucose release, sugar sensing, gut hormones, and neurohormonal negative feedback mechanisms. It is hoped that a deep understanding of these physiological processes will facilitate the development of innovative dietary approaches to achieve desired carbohydrate or glucose bioavailability for improved health.
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Affiliation(s)
- Genyi Zhang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
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60
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Ting CH, Chen YC, Liaw WJ, Lin HC, Chen CY. Peripheral injection of pancreatic polypeptide enhances colonic transit without eliciting anxiety or altering colonic secretion in rats. Neuropeptides 2016; 55:67-71. [PMID: 26601891 DOI: 10.1016/j.npep.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 10/10/2015] [Accepted: 10/11/2015] [Indexed: 12/11/2022]
Abstract
Pancreatic polypeptide (PP) is a negative regulator of energy homeostasis that suppresses food intake and lowers body weight. Similar to other gastrointestinal-derived peptides, PP also modulates gastrointestinal motility and may be involved in the regulation of anxiety. Previous studies revealed that PP suppresses gastric emptying but increases colonic motility in mice. In our present study, we assessed the effect of PP on anxiety as well as colonic motility and secretory function. Intracerebroventricular and intravenous routes of PP were administered in conscious rats. Our results showed that intracerebroventricular administration of PP did not affect anxiety in the open field test. Intravenous injection of PP accelerated colonic transit, but did not significantly change fecal amount and fecal fluid composition. On the other hand, intracerebroventricular injection of PP did not alter colonic transit, fecal amount, or fluid composition. In conclusion, peripheral, but not central PP administration enhances colonic motility without eliciting anxiety or altering colonic secretion.
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Affiliation(s)
- Ching-Heng Ting
- Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ying-Chieh Chen
- Division of Digestive Medicine, Taipei City Hospital Yangming Branch, Taipei, Taiwan
| | - Wen-Jinn Liaw
- Department of Anesthesiology, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan; Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
| | - Han-Chieh Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Chih-Yen Chen
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan.
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61
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Khandekar N, Berning BA, Sainsbury A, Lin S. The role of pancreatic polypeptide in the regulation of energy homeostasis. Mol Cell Endocrinol 2015; 418 Pt 1:33-41. [PMID: 26123585 DOI: 10.1016/j.mce.2015.06.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/16/2015] [Accepted: 06/03/2015] [Indexed: 12/13/2022]
Abstract
Imbalances in normal regulation of food intake can cause obesity and related disorders. Inadequate therapies for such disorders necessitate better understanding of mechanisms that regulate energy homeostasis. Pancreatic polypeptide (PP), a robust anorexigenic hormone, effectively modulates food intake and energy homeostasis, thus potentially aiding anti-obesity therapeutics. Intra-gastric and intra-intestinal infusion of nutrients stimulate PP secretion from the gastrointestinal tract, leading to vagal stimulation that mediates complex actions via the neuropeptide Y4 receptor in arcuate nucleus of the hypothalamus, subsequently activating key hypothalamic nuclei and dorsal vagal complex of the brainstem to influence energy homeostasis and body composition. Novel studies indicate affinity of PP for the relatively underexplored neuropeptide y6 receptor, mediating actions via the suprachiasmatic nucleus and pathways involving vasoactive intestinal polypeptide and insulin like growth factor 1. This review highlights detailed mechanisms by which PP mediates its actions on energy balance through various areas in the brain.
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Affiliation(s)
- Neeta Khandekar
- Neurological Diseases Division, Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia
| | - Britt A Berning
- Neurological Diseases Division, Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia
| | - Amanda Sainsbury
- The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Shu Lin
- Neurological Diseases Division, Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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62
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Forbes S, Stafford S, Coope G, Heffron H, Real K, Newman R, Davenport R, Barnes M, Grosse J, Cox H. Selective FFA2 Agonism Appears to Act via Intestinal PYY to Reduce Transit and Food Intake but Does Not Improve Glucose Tolerance in Mouse Models. Diabetes 2015; 64:3763-71. [PMID: 26239054 DOI: 10.2337/db15-0481] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/26/2015] [Indexed: 12/28/2022]
Abstract
Free fatty acid receptor 2 (FFA2) is expressed on enteroendocrine L cells that release glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) when activated by short-chain fatty acids (SCFAs). Functionally GLP-1 and PYY inhibit gut transit, increase glucose tolerance, and suppress appetite; thus, FFA2 has therapeutic potential for type 2 diabetes and obesity. However, FFA2-selective agonists have not been characterized in vivo. Compound 1 (Cpd 1), a potent FFA2 agonist, was tested for its activity on the following: GLP-1 release, modulation of intestinal mucosal ion transport and transit in wild-type (WT) and FFA2(-/-) tissue, and food intake and glucose tolerance in lean and diet-induced obese (DIO) mice. Cpd 1 stimulated GLP-1 secretion in vivo, but this effect was only detected with dipeptidyl peptidase IV inhibition, while mucosal responses were PYY, not GLP-1, mediated. Gut transit was faster in FFA2(-/-) mice, while Cpd 1 slowed WT transit and reduced food intake and body weight in DIO mice. Cpd 1 decreased glucose tolerance and suppressed plasma insulin in lean and DIO mice, despite FFA2(-/-) mice displaying impaired glucose tolerance. These results suggest that FFA2 inhibits intestinal functions and suppresses food intake via PYY pathways, with limited GLP-1 contribution. Thus, FFA2 may be an effective therapeutic target for obesity but not for type 2 diabetes.
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Affiliation(s)
- Sarah Forbes
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, Guy's Campus, King's College London, London, U.K
| | | | | | | | | | | | | | | | | | - Helen Cox
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, Guy's Campus, King's College London, London, U.K.
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Shi YC, Loh K, Bensellam M, Lee K, Zhai L, Lau J, Cantley J, Luzuriaga J, Laybutt DR, Herzog H. Pancreatic PYY Is Critical in the Control of Insulin Secretion and Glucose Homeostasis in Female Mice. Endocrinology 2015; 156:3122-36. [PMID: 26125465 DOI: 10.1210/en.2015-1168] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Insulin secretion is tightly controlled through coordinated actions of a number of systemic and local factors. Peptide YY (PYY) is expressed in α-cells of the islet, but its role in control of islet function such as insulin release is not clear. In this study, we generated a transgenic mouse model (Pyy(tg/+)/Rip-Cre) overexpressing the Pyy gene under the control of the rat insulin 2 gene promoter and assessed the impact of islet-released PYY on β-cell function, insulin release, and glucose homeostasis in mice. Our results show that up-regulation of PYY in islet β-cells leads to an increase in serum insulin levels as well as improved glucose tolerance. Interestingly, PYY-overproducing mice show increased lean mass and reduced fat mass with no significant changes in food intake or body weight. Energy expenditure is also increased accompanied by increased respiratory exchange ratio. Mechanistically, the enhanced insulin levels and improved glucose tolerance are primarily due to increased β-cell mass and secretion. This is associated with alterations in the expression of genes important for β-cell proliferation and function as well as the maintenance of the β-cell phenotype. Taken together, these data demonstrate that pancreatic islet-derived PYY plays an important role in controlling glucose homeostasis through the modulation of β-cell mass and function.
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Affiliation(s)
- Yan-Chuan Shi
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Kim Loh
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Mohammed Bensellam
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Kailun Lee
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Lei Zhai
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Jackie Lau
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - James Cantley
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Jude Luzuriaga
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - D Ross Laybutt
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
| | - Herbert Herzog
- Neuroscience (Y.-C.S., K.Lo., K.Le., L.Z., J.La., H.H.) and Diabetes and Metabolism (M.B., J.C., J.Lu., D.R.L.) Divisions, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst NSW 2010, Sydney, Australia; Faculty of Medicine (Y.-C.S., K.Lo., J.C., D.R.L., H.H.), UNSW Australia, Sydney, NSW, 2052 Australia; and Department of Physiology, Anatomy and Genetics (J.C.), University of Oxford, Oxford, OX1 3QX United Kingdom
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64
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Gut satiety hormones and hyperemesis gravidarum. Arch Gynecol Obstet 2015; 292:1225-30. [DOI: 10.1007/s00404-015-3751-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 05/11/2015] [Indexed: 10/23/2022]
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Farzi A, Reichmann F, Holzer P. The homeostatic role of neuropeptide Y in immune function and its impact on mood and behaviour. Acta Physiol (Oxf) 2015; 213:603-27. [PMID: 25545642 DOI: 10.1111/apha.12445] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/10/2014] [Accepted: 12/21/2014] [Indexed: 12/18/2022]
Abstract
Neuropeptide Y (NPY), one of the most abundant peptides in the nervous system, exerts its effects via five receptor types, termed Y1, Y2, Y4, Y5 and Y6. NPY's pleiotropic functions comprise the regulation of brain activity, mood, stress coping, ingestion, digestion, metabolism, vascular and immune function. Nerve-derived NPY directly affects immune cells while NPY also acts as a paracrine and autocrine immune mediator, because immune cells themselves are capable of producing and releasing NPY. NPY is able to induce immune activation or suppression, depending on a myriad of factors such as the Y receptors activated and cell types involved. There is an intricate relationship between psychological stress, mood disorders and the immune system. While stress represents a risk factor for the development of mood disorders, it exhibits diverse actions on the immune system as well. Conversely, inflammation is regarded as an internal stressor and is increasingly recognized to contribute to the pathogenesis of mood and metabolic disorders. Intriguingly, the cerebral NPY system has been found to protect against distinct disturbances in response to immune challenge, attenuating the sickness response and preventing the development of depression. Thus, NPY plays an important homeostatic role in balancing disturbances of physiological systems caused by peripheral immune challenge. This implication is particularly evident in the brain in which NPY counteracts the negative impact of immune challenge on mood, emotional processing and stress resilience. NPY thus acts as a unique signalling molecule in the interaction of the immune system with the brain in health and disease.
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Affiliation(s)
- A. Farzi
- Research Unit of Translational Neurogastroenterology; Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - F. Reichmann
- Research Unit of Translational Neurogastroenterology; Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - P. Holzer
- Research Unit of Translational Neurogastroenterology; Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
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66
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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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67
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Aragón F, Karaca M, Novials A, Maldonado R, Maechler P, Rubí B. Pancreatic polypeptide regulates glucagon release through PPYR1 receptors expressed in mouse and human alpha-cells. Biochim Biophys Acta Gen Subj 2014; 1850:343-51. [PMID: 25445712 DOI: 10.1016/j.bbagen.2014.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/01/2014] [Accepted: 11/04/2014] [Indexed: 12/24/2022]
Abstract
BACKGROUND Plasma levels of pancreatic polypeptide (PP) rise upon food intake. Although other pancreatic islet hormones, such as insulin and glucagon, have been extensively investigated, PP secretion and actions are still poorly understood. METHODS The release of PP upon glucose stimulation and the effects of PP on glucagon and insulin secretion were analyzed in isolated pancreatic islets. Expression of PP receptor (PPYR1) was investigated by immunoblotting, quantitative RT-PCR on sorted pancreatic islet cells, and immunohistochemistry. RESULTS In isolated mouse pancreatic islets, glucose stimulation increased PP release, while insulin secretion was up and glucagon release was down. Direct exposure of islets to PP inhibited glucagon release. In mouse islets, PPYR1 protein was observed by immunoblotting and quantitative RT-PCR revealed PPYR1 expression in the FACS-enriched glucagon alpha-cell fraction. Immunohistochemistry on pancreatic sections showed the presence of PPYR1 in alpha-cells of both mouse and human islets, while the receptor was absent in other islet cell types and exocrine pancreas. CONCLUSIONS Glucose stimulates PP secretion and PP inhibits glucagon release in mouse pancreatic islets. PP receptors are present in alpha-cells of mouse and human pancreatic islets. GENERAL SIGNIFICANCE These data demonstrate glucose-regulated secretion of PP and its effects on glucagon release through PPYR1 receptors expressed by alpha-cells.
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Affiliation(s)
- F Aragón
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - M Karaca
- Department of Cell Physiology and Metabolism, Geneva University Medical Center, Geneva, Switzerland
| | - A Novials
- Diabetes Research Laboratory. IDIBAPS (Institut Investigacions Biomèdiques August Pi i Sunyer), CIBERDEM, Barcelona, Spain
| | - R Maldonado
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - P Maechler
- Department of Cell Physiology and Metabolism, Geneva University Medical Center, Geneva, Switzerland.
| | - B Rubí
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain.
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68
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Babenko AY, Neymark AE, Anisimova KA, Grineva Elena Nikolaevna ENN. Effects of bariatric surgery on the level of hormones that regulate body weight. What is the basis of success? ACTA ACUST UNITED AC 2014. [DOI: 10.14341/omet201443-11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The growth of obesity and type 2 diabetes incidence has made bariatric surgery a widespread method of treatment. The effectiveness of bariatricoperations in the treatment of obesity and related metabolic diseases is thoroughly highlighted in medical literature. However, the resultsof surgery do not always correlate with type of operation. As before, the mechanisms have not been fully studied of how the bariatric surgeryinfluence on insulinresistance, entero-insulin axes, adipokines. Understanding such mechanisms will allow us to determine more precisely theindications relating to surgical treatment, and enhance the effectiveness of surgery in specific patient. The review is focusing on the influence ofvarious types of bariatric surgery on the level of adipokines and incretines that participate in regulation of appetite and of fat and carbohydratemetabolism. The article elaborates modern concepts related to the impact of bariatric operations on metabolic disorders in obesity.
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69
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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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70
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Streptozotocin-induced diabetes models: pathophysiological mechanisms and fetal outcomes. BIOMED RESEARCH INTERNATIONAL 2014; 2014:819065. [PMID: 24977161 PMCID: PMC4058231 DOI: 10.1155/2014/819065] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 04/30/2014] [Accepted: 05/14/2014] [Indexed: 12/26/2022]
Abstract
Glucose homeostasis is controlled by endocrine pancreatic cells, and any pancreatic disturbance can result in diabetes. Because 8% to 12% of diabetic pregnant women present with malformed fetuses, there is great interest in understanding the etiology, pathophysiological mechanisms, and treatment of gestational diabetes. Hyperglycemia enhances the production of reactive oxygen species, leading to oxidative stress, which is involved in diabetic teratogenesis. It has also been suggested that maternal diabetes alters embryonic gene expression, which might cause malformations. Due to ethical issues involving human studies that sometimes have invasive aspects and the multiplicity of uncontrolled variables that can alter the uterine environment during clinical studies, it is necessary to use animal models to better understand diabetic pathophysiology. This review aimed to gather information about pathophysiological mechanisms and fetal outcomes in streptozotocin-induced diabetic rats. To understand the pathophysiological mechanisms and factors involved in diabetes, the use of pancreatic regeneration studies is increasing in an attempt to understand the behavior of pancreatic beta cells. In addition, these studies suggest a new preventive concept as a treatment basis for diabetes, introducing therapeutic efforts to minimize or prevent diabetes-induced oxidative stress, DNA damage, and teratogenesis.
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71
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Yuan D, Zhou C, Wang T, Lin F, Chen H, Wu H, Wei R, Xin Z, Liu J, Gao Y, Chen D, Yang S, Wang Y, Pu Y, Li Z. Molecular characterization and tissue expression of peptide YY in Schizothorax prenanti: Effects of periprandial changes and fasting on expression in the hypothalamus. ACTA ACUST UNITED AC 2014; 190-191:32-8. [DOI: 10.1016/j.regpep.2014.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 02/23/2014] [Accepted: 03/18/2014] [Indexed: 10/25/2022]
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72
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Saeed S, Bech PR, Hafeez T, Alam R, Falchi M, Ghatei MA, Bloom SR, Arslan M, Froguel P. Changes in levels of peripheral hormones controlling appetite are inconsistent with hyperphagia in leptin-deficient subjects. Endocrine 2014; 45:401-8. [PMID: 23824601 DOI: 10.1007/s12020-013-0009-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 06/22/2013] [Indexed: 01/05/2023]
Abstract
Congenital leptin deficiency, a rare genetic disorder due to a homozygous mutation in the leptin gene (LEP), is accompanied by extreme obesity and hyperphagia. A number of gastrointestinal hormones have been shown to critically regulate food intake but their physiological role in hyperphagic response in congenital leptin deficiency has not been elucidated. This study is the first to evaluate the fasting and postprandial profiles of gut-derived hormones in homozygous and heterozygous carriers of LEP mutation. The study subjects from two consanguineous families consisted of five homozygous and eight heterozygous carriers of LEP mutation, c.398delG. Ten wild-type normal-weight subjects served as controls. Fasting and 1-h postprandial plasma ghrelin, glucagon-like peptide (GLP) 1, peptide YY (PYY), leptin and insulin levels were measured by immunoassays. Fasting plasma ghrelin levels in homozygotes remained remarkably unchanged following food consumption (P = 0.33) in contrast to a significant decline in heterozygous (P < 0.03) and normal (P < 0.02) subjects. A significant postprandial increase in PYY was observed in heterozygous (P < 0.02) and control subjects (P < 0.01), but not in the homozygous group (P = 0.22). A postprandial rise in GLP-1 levels was significant (P < 0.02) in all groups. Interestingly, fasting leptin levels in heterozygotes were not significantly different from controls and did not change significantly following meal. Our results demonstrate that gut hormones play little or no physiological role in driving the hyperphagic response of leptin-deficient subjects. In contrast, fasting and postprandial levels of gut hormones in heterozygous mutation carriers were comparable to those of normal-weight controls.
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Affiliation(s)
- Sadia Saeed
- Department of Genomics of Common Disease, Hammersmith Hospital, Imperial College London, Burlington-Danes Building, Du Cane Road, London, W12 0NN, UK
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73
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Weltens N, Zhao D, Van Oudenhove L. Where is the comfort in comfort foods? Mechanisms linking fat signaling, reward, and emotion. Neurogastroenterol Motil 2014; 26:303-15. [PMID: 24548257 DOI: 10.1111/nmo.12309] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 12/30/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Food in general, and fatty foods in particular, have obtained intrinsic reward value throughout evolution. This reward value results from an interaction between exteroceptive signals from different sensory modalities, interoceptive hunger/satiety signals from the gastrointestinal tract to the brain, as well as ongoing affective and cognitive processes. Further evidence linking food to emotions stems from folk psychology ('comfort foods') and epidemiological studies demonstrating high comorbidity rates between disorders of food intake, including obesity, and mood disorders such as depression. PURPOSE This review paper aims to give an overview of current knowledge on the neurophysiological mechanisms underlying the link between (fatty) foods, their reward value, and emotional responses to (anticipation of) their intake in humans. Firstly, the influence of exteroceptive sensory signals, including visual, olfactory ('anticipatory food reward'), and gustatory ('consummatory food reward'), on the encoding of reward value in the (ventral) striatum and of subjective pleasantness in the cingulate and orbitofrontal cortex will be discussed. Differences in these pathways and mechanisms between lean and obese subjects will be highlighted. Secondly, recent studies elucidating the mechanisms of purely interoceptive fatty acid-induced signaling from the gastrointestinal tract to the brain, including the role of gut peptides, will be presented. These studies have demonstrated that such subliminal interoceptive stimuli may impact on hedonic circuits in the brain, and thereby influence the subjective and neural responses to negative emotion induction. This suggests that the effect of foods on mood may even occur independently from their exteroceptive sensory properties.
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Affiliation(s)
- N Weltens
- Translational Research Centre for Gastrointestinal Disorders (TARGID), Department of Clinical & Experimental Medicine, University of Leuven, Leuven, Belgium
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74
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Pedragosa-Badia X, Sliwoski GR, Dong Nguyen E, Lindner D, Stichel J, Kaufmann KW, Meiler J, Beck-Sickinger AG. Pancreatic polypeptide is recognized by two hydrophobic domains of the human Y4 receptor binding pocket. J Biol Chem 2014; 289:5846-59. [PMID: 24375409 PMCID: PMC3937655 DOI: 10.1074/jbc.m113.502021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 12/21/2013] [Indexed: 12/12/2022] Open
Abstract
Structural characterization of the human Y4 receptor (hY4R) interaction with human pancreatic polypeptide (hPP) is crucial, not only for understanding its biological function but also for testing treatment strategies for obesity that target this interaction. Here, the interaction of receptor mutants with pancreatic polypeptide analogs was studied through double-cycle mutagenesis. To guide mutagenesis and interpret results, a three-dimensional comparative model of the hY4R-hPP complex was constructed based on all available class A G protein-coupled receptor crystal structures and refined using experimental data. Our study reveals that residues of the hPP and the hY4R form a complex network consisting of ionic interactions, hydrophobic interactions, and hydrogen binding. Residues Tyr(2.64), Asp(2.68), Asn(6.55), Asn(7.32), and Phe(7.35) of Y4R are found to be important in receptor activation by hPP. Specifically, Tyr(2.64) interacts with Tyr(27) of hPP through hydrophobic contacts. Asn(7.32) is affected by modifications on position Arg(33) of hPP, suggesting a hydrogen bond between these two residues. Likewise, we find that Phe(7.35) is affected by modifications of hPP at positions 33 and 36, indicating interactions between these three amino acids. Taken together, we demonstrate that the top of transmembrane helix 2 (TM2) and the top of transmembrane helices 6 and 7 (TM6-TM7) form the core of the peptide binding pocket. These findings will contribute to the rational design of ligands that bind the receptor more effectively to produce an enhanced agonistic or antagonistic effect.
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Affiliation(s)
- Xavier Pedragosa-Badia
- From the Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, 04103 Leipzig, Germany and
| | - Gregory R. Sliwoski
- the Center for Structural Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8725
| | - Elizabeth Dong Nguyen
- the Center for Structural Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8725
| | - Diana Lindner
- From the Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, 04103 Leipzig, Germany and
| | - Jan Stichel
- From the Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, 04103 Leipzig, Germany and
| | - Kristian W. Kaufmann
- the Center for Structural Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8725
| | - Jens Meiler
- the Center for Structural Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8725
| | - Annette G. Beck-Sickinger
- From the Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, 04103 Leipzig, Germany and
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Abstract
The islets of Langerhans are key regulators of glucose homeostasis and have been known as a structure for almost one and a half centuries. During the twentieth century several different cell types were described in the islets of different species and at different developmental stages. Six cell types with identified hormonal product have been described so far by the use of histochemical staining methods, transmission electron microscopy, and immunohistochemistry. Thus, glucagon-producing α-cells, insulin-producing β-cells, somatostatin-producing δ-cells, pancreatic polypeptide-producing PP-cells, serotonin-producing enterochromaffin-cells, and gastrin-producing G-cells have all been found in the mammalian pancreas at least at some developmental stage. Species differences are at hand and age-related differences are also to be considered. Eleven years ago a novel cell type, the ghrelin cell, was discovered in the human islets. Subsequent studies have shown the presence of islet ghrelin cells in several animals, including mouse, rat, gerbils, and fish. The developmental regulation of ghrelin cells in the islets of mice has gained a lot of interest and several studies have added important pieces to the puzzle of molecular mechanisms and the genetic regulation that lead to differentiation into mature ghrelin cells. A body of evidence has shown that ghrelin is an insulinostatic hormone, and the potential for blockade of ghrelin signalling as a therapeutic avenue for type 2 diabetes is intriguing. Furthermore, ghrelin-expressing pancreatic tumours have been reported and ghrelin needs to be taken into account when diagnosing pancreatic tumours. In this review article, we summarise the knowledge about islet ghrelin cells obtained so far.
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Affiliation(s)
- Nils Wierup
- Unit of Neuroendocrine Cell Biology, Department of Clinical Sciences in Malmö, Lund University Diabetes Centre, Clinical Research Centre, Scania University Hospital, Jan Waldenströms gata 35, SE 205 02 Malmö, Sweden Imaging Team, Novo Nordisk A/S, Novo Nordisk Park, DK2760 Måløv, Denmark
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76
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Chen Y, Pandit NP, Fu J, Li D, Li J. Identification, characterization and feeding response of peptide YYb (PYYb) gene in grass carp (Ctenopharyngodon idellus). FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:45-55. [PMID: 23780740 DOI: 10.1007/s10695-013-9822-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/10/2013] [Indexed: 06/02/2023]
Abstract
The peptide YYb (PYYb) is a fish-specific peptide belonging to the neuropeptide Y (NPY) family. In the present study, the full-length cDNA sequence and genomic structure of PYYb (gcPYYb) from Ctenopharyngodon idellus have been isolated and characterized. The gcPYYb gene consists of three exons interspaced by two introns, opposing to the typical architecture of most NPY-family genes as well as its paralogs. Alignment of deduced amino acid sequence indicates that the fish PYYb is more variable compared to NPY and PYY as shown by more residue changes in teleosts lineage, suggesting mild selective pressure imposed on the peptide. Real-time quantitative PCR analysis shows the gcPYYb mRNA in developing larvae is increased during the mixed endo- and exogenous-feeding period and is widely distributed throughout the intestine of fully grown individuals. Following a single meal, the gcPYYb mRNA in foregut is increased at 3 h post-feeding and subsequently decreased before the foregut contents are cleared. These results suggest that the gcPYYb has an important role in the early life stages of grass carp and is involved in food intake by transmitting feeding-related signals.
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Affiliation(s)
- Yong Chen
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
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77
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Papastamataki M, Papassotiriou I, Bartzeliotou A, Vazeou A, Roma E, Chrousos GP, Kanaka-Gantenbein C. Incretins, amylin and other gut-brain axis hormones in children with coeliac disease. Eur J Clin Invest 2014; 44:74-82. [PMID: 24151959 DOI: 10.1111/eci.12193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 10/19/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Previous research indicated that coeliac disease (CD) is associated with type 1 diabetes mellitus (T1DM). However, the gut-brain axis peptide hormones secretion has not been evaluated so far in patients with CD prior to treatment initiation or under treatment, irrespective of patients having concomitant T1DM or not. The aim of the study was therefore to evaluate these gut hormones at the preprandial levels of patients with CD before and under treatment. METHODS Of forty-seven CD children, 12 untreated (UCD), 22 treated with gluten-free diet (TCD) and 13 treated CD with coexisting T1DM (DCD), and 18 healthy controls (HC) were enrolled. Preprandial glucagon-like-peptide-1 (GLP-1), glucose-dependent-insulinotropic-polypeptide (GIP), active amylin, acylated ghrelin (AG), leptin, pancreatic polypeptide (PP) and peptide-tyrosine-tyrosine (PYY) were determined with hormone-map-array technology. RESULTS We found in patients with CD compared with HC that the concentration of (i) GLP-1 was reduced remarkably in all patients with CD (P = 0.008), (ii) GIP was lower in patients with UCD (P = 0.008), (iii) amylin was remarkably reduced (P < 0.01) in all patients with CD, (iv) AG was significantly decreased in patients with DCD (P < 0.01), while (v) leptin, PP and PYY were not significantly different. GIP, GLP-1 and amylin levels correlated positively with insulin concentrations (P < 0.001, P = 0.004 and P < 0.01, respectively) in all patients. Amylin and GIP levels were strongly associated with triglycerides concentrations (P < 0.001, for both peptides) in children with CD. CONCLUSIONS Our study revealed a different secretion pattern of gut-brain axis hormones in children with CD compared with HC. The alterations in the axis were more pronounced in children with both CD and T1DM.
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Affiliation(s)
- Maria Papastamataki
- Department of Clinical Biochemistry, 'Aghia Sophia' Children's Hospital, Athens, Greece
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78
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Hill BR, De Souza MJ, Wagstaff DA, Williams NI. The impact of weight loss on the 24-h profile of circulating peptide YY and its association with 24-h ghrelin in normal weight premenopausal women. Peptides 2013; 49:81-90. [PMID: 24012997 PMCID: PMC4218746 DOI: 10.1016/j.peptides.2013.08.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 08/25/2013] [Accepted: 08/26/2013] [Indexed: 02/05/2023]
Abstract
Peptide YY (PYY) and ghrelin exhibit a reciprocal association and antagonistic physiological effects in the peripheral circulation. Research has yet to clarify the effect of weight loss on the 24h profile of PYY or its association to 24h ghrelin. We sought to determine if diet- and exercise-induced weight loss affects the 24h profile of PYY and its association with 24h ghrelin in normal weight, premenopausal women. Participants (n = 13) were assessed at baseline (BL) and after a 3-month diet and exercise intervention (post). Blood samples obtained q10 min for 24h were assayed for total PYY and total ghrelin q60 min from 0800 to 1000 h and 2000 to 0800 h and q20 min from 1000 to 2000 h. The ghrelin/PYY ratio was used as an index of hormonal exposure. Statistical analyses included paired t-tests and linear mixed effects modeling. Body weight (-1.85 ± 0.67 kg; p = 0.02), and body fat (-2.53 ± 0.83%; p = 0.01) decreased from BL to post. Ghrelin AUC (5252 ± 2177 pg/ml/24h; p=0.03), 24h mean (216 ± 90 pg/ml; p = 0.03) and peak (300 ± 134 pg/ml; p = 0.047) increased from BL to post. No change occurred in PYY AUC (88.2 ± 163.7 pg/ml; p = 0.60), 24h mean (4.8 ± 6.9 pg/ml; p = 0.50) or peak (3.6 ± 6.4 pg/ml; p = 0.58). The 24h association between PYY and ghrelin at baseline (p = 0.04) was weakened at post (p = 0.14); however, the ghrelin/PYY lunch ratio increased (p = 0.01) indicating the potential for ghrelin predominance over PYY in the circulation. PYY and ghrelin are reciprocally associated during a period of weight stability, but not following weight loss. An "uncoupling" may have occurred, particularly at lunch, due to factors that modulate ghrelin in response to weight loss.
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Affiliation(s)
- Brenna R. Hill
- Women’s Health and Exercise Laboratory and the Department of Kinesiology, Pennsylvania State University, University Park, PA 16802
| | - Mary Jane De Souza
- Women’s Health and Exercise Laboratory and the Department of Kinesiology, Pennsylvania State University, University Park, PA 16802
| | - David A. Wagstaff
- Health and Human Development Consulting Group, College of Health and Human Development, Pennsylvania State University, University Park, PA 16802
| | - Nancy I. Williams
- Women’s Health and Exercise Laboratory and the Department of Kinesiology, Pennsylvania State University, University Park, PA 16802
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79
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Atalayer D, Astbury NM. Anorexia of aging and gut hormones. Aging Dis 2013; 4:264-75. [PMID: 24124632 DOI: 10.14336/ad.2013.0400264] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 08/02/2013] [Accepted: 08/02/2013] [Indexed: 12/20/2022] Open
Abstract
We are expected to live longer than if we had been born 100 years ago however, the additional years are not necessarily spent in good health or free from disability. Body composition changes dramatically over the course of life. There is a gradual increase in body weight throughout adult life until the age of about 60-65 years. In contrast, body weight appears to decrease with age after the age of 65-75 years, even in those demonstrating a previous healthy body weight. This age related decrease in body weight, often called unintentional weight loss or involuntary weight loss can be a significant problem for the elderly. This has been shown to be related to decline in appetite and food intake is common amongst the elderly and is often referred to the anorexia of aging. Underlying mechanisms regulate energy homeostasis and appetite may change as people age. In this review, peripheral factors regulating appetite have been summarized in regards to their age-dependent changes and role in the etiology of anorexia of aging. Understanding the alterations in the mechanisms regulating appetite and food intake in conjunction with aging may help inform strategies that promote healthy aging and promote health and wellbeing in the elderly years, with the end goal to add life to the years and not just years to our lives.
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Affiliation(s)
- Deniz Atalayer
- Department of Institute of Human Nutrition, Columbia University College of Physicians and Surgeons, New York, NY 10025, USA ; Department of Medicine, New York Obesity Research and Nutrition Center, St. Luke's-Roosevelt Hospital, New York, NY 10025, USA
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80
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La Sala MS, Hurtado MD, Brown AR, Bohórquez DV, Liddle RA, Herzog H, Zolotukhin S, Dotson CD. Modulation of taste responsiveness by the satiation hormone peptide YY. FASEB J 2013; 27:5022-33. [PMID: 24043261 DOI: 10.1096/fj.13-228064] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It has been hypothesized that the peripheral taste system may be modulated in the context of an animal's metabolic state. One purported mechanism for this phenomenon is that circulating gastrointestinal peptides modulate the functioning of the peripheral gustatory system. Recent evidence suggests endocrine signaling in the oral cavity can influence food intake (FI) and satiety. We hypothesized that these hormones may be affecting FI by influencing taste perception. We used immunohistochemistry along with genetic knockout models and the specific reconstitution of peptide YY (PYY) in saliva using gene therapy protocols to identify a role for PYY signaling in taste. We show that PYY is expressed in subsets of taste cells in murine taste buds. We also show, using brief-access testing with PYY knockouts, that PYY signaling modulates responsiveness to bitter-tasting stimuli, as well as to lipid emulsions. We show that salivary PYY augmentation, via viral vector therapy, rescues behavioral responsiveness to a lipid emulsion but not to bitter stimuli and that this response is likely mediated via activation of Y2 receptors localized apically in taste cells. Our findings suggest distinct functions for PYY produced locally in taste cells vs. that circulating systemically.
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Affiliation(s)
- Michael S La Sala
- 1Department of Neuroscience, University of Florida McKnight Brain Institute, 1149 Newell Dr., Box 100244, Gainesville, FL 32611, USA.
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81
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Chen Y, Shen Y, Pandit NP, Fu J, Li D, Li J. Molecular cloning, expression analysis, and potential food intake attenuation effect of peptide YY in grass carp (Ctenopharyngodon idellus). Gen Comp Endocrinol 2013; 187:66-73. [PMID: 23583472 DOI: 10.1016/j.ygcen.2013.03.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 03/23/2013] [Accepted: 03/25/2013] [Indexed: 10/27/2022]
Abstract
The peptide YY (PYY) is a 36 amino acid peptide involved in the food intake control in vertebrates. We have cloned and characterized a PYY gene from grass carp Ctenopharyngodon idellus. The full-length cDNA encodes a precursor protein of grass carp PYY (gcPYY) that consists of a putative 28-amino acid signal peptide, a 36-amino acid mature peptide, an amidation-proteolytic site, and a 30-amino acid carboxy-terminal extension. The gcPYY gene is comprised of 4 exons interspaced by 3 introns as seen in PYYs from other species. Amino acid alignment and gene structure comparison indicate that the structure of PYY is well preserved throughout vertebrate phylogeny. The tissue distribution and postprandial changes in gcPYY mRNA expression were evaluated by real-time PCR, which showed that the gcPYY is expressed abundantly in the central nervous system, with significantly increased expression following a single meal. During embryogenesis, the presence of gcPYY mRNA was detected in early developing embryos, and high expression levels were observed when most larvae completed their switch from endogenous nourishment to exogenous feeding. Reduced food intake by juveniles during a single meal after giving perpheral injection of gcPYY1-36 suggests a potentially important role of PYY in the food intake attenuation in grass carp.
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Affiliation(s)
- Yong Chen
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
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82
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Reidelberger R, Haver A, Chelikani PK. Role of peptide YY(3-36) in the satiety produced by gastric delivery of macronutrients in rats. Am J Physiol Endocrinol Metab 2013; 304:E944-50. [PMID: 23482449 PMCID: PMC3651646 DOI: 10.1152/ajpendo.00075.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Peptide YY(3-36) [PYY(3-36)] is postulated to act as a hormonal signal from gut to brain to inhibit food intake. PYY(3-36) potently reduces food intake when administered systemically or into the brain. If action of endogenous PYY(3-36) is necessary for normal satiation to occur, then pharmacological blockade of its receptors should increase food intake. Here, we determined the effects of iv infusion of Y1, Y2, and Y5 receptor antagonists (BIBP 3226, BIIE 0246, CGP 71683) during the first 3 h of the dark period on food intake in non-food-deprived rats. Our results showed that 1) Y2 receptor blockade reversed the anorexic response to iv infusion of PYY(3-36) but did not increase food intake when administered alone; 2) Y1 and Y5 receptor antagonists neither attenuated PYY(3-36)-induced anorexia nor altered food intake when given alone; and 3) Y2 receptor blockade attenuated anorexic responses to gastric infusions of casein hydrolysate and long-chain triglycerides, but not maltodextrin. Previous work showed that Y2 antagonist BIIE 0246 does not penetrate the blood-brain barrier. Together, these results support the hypothesis that gut PYY(3-36) action at Y2 receptors peripheral to the blood brain barrier plays an essential role in mediating satiety responses to gastric delivery of protein and long-chain triglycerides, but not polysaccharide.
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Affiliation(s)
- Roger Reidelberger
- Veterans Affairs Research Service, Veterans Affairs Nebraska Western Iowa Health Care System, Omaha, NE 68105, USA
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83
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Heden TD, Liu Y, Sims L, Kearney ML, Whaley-Connell AT, Chockalingam A, Dellsperger KC, Fairchild TJ, Kanaley JA. Liquid meal composition, postprandial satiety hormones, and perceived appetite and satiety in obese women during acute caloric restriction. Eur J Endocrinol 2013; 168:593-600. [PMID: 23371976 PMCID: PMC9583695 DOI: 10.1530/eje-12-0884] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE The purpose of this study was to compare postprandial satiety regulating hormone responses (pancreatic polypeptide (PP) and peptide tyrosine tyrosine (PYY)) and visual analog scale- (VAS) assessed perceived appetite and satiety between liquid high-protein (HP) and high-carbohydrate (HC) meals in obese women during acute (24-h) caloric restriction. DESIGN Eleven obese premenopausal women completed two conditions in random order in which they consumed 1500 calories as six 250-calorie HP meals or six 250-calorie HC meals over a 12-h period. Blood samples were taken at baseline and every 20 min thereafter and analyzed for PP and PYY concentrations. At these same points, perceived hunger and fullness were assessed with a VAS. The incremental area under the curve (iAUC) was used to compare postprandial responses. RESULTS The 12-h PP and PYY iAUC were greater (P≤0.05) during the HP condition (PP: 4727±1306 pg/ml×12 h, PYY: 1373±357 pg/ml×12 h) compared with the HC condition (PP: 2300±528 pg/ml×12 h, PYY: 754±246 pg/ml×12 h). Perceived hunger and fullness were not different between conditions (P>0.05). The greatest changes in PYY and perceived fullness occurred after the morning meals during both conditions. CONCLUSIONS These data suggest that in obese women during acute caloric restriction before weight loss, i) liquid HP meals, compared with HC meals, result in greater postprandial PP and PYY concentrations, an effect not associated with differential appetite or satiety responses, and ii) meal-induced changes in PYY and satiety are greatest during the morning period, regardless of dietary macronutrient composition.
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Affiliation(s)
- Timothy D Heden
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri 65211, USA
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84
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Wu W, Bates MA, Bursian SJ, Flannery B, Zhou HR, Link JE, Zhang H, Pestka JJ. Peptide YY3-36 and 5-hydroxytryptamine mediate emesis induction by trichothecene deoxynivalenol (vomitoxin). Toxicol Sci 2013; 133:186-95. [PMID: 23457120 DOI: 10.1093/toxsci/kft033] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Deoxynivalenol (DON, vomitoxin), a trichothecene mycotoxin produced by Fusarium sp. that frequently occurs in cereal grains, has been associated with human and animal food poisoning. Although a common hallmark of DON-induced toxicity is the rapid onset of emesis, the mechanisms for this adverse effect are not fully understood. Recently, our laboratory has demonstrated that the mink (Neovison vison) is a suitable small animal model for investigating trichothecene-induced emesis. The goal of this study was to use this model to determine the roles of two gut satiety hormones, peptide YY3-36 (PYY3-36) and cholecystokinin (CCK), and the neurotransmitter 5-hydroxytryptamine (5-HT) in DON-induced emesis. Following ip exposure to DON at 0.1 and 0.25mg/kg bw, emesis induction ensued within 15-30min and then persisted up to 120min. Plasma DON measurement revealed that this emesis period correlated with the rapid distribution and clearance of the toxin. Significant elevations in both plasma PYY3-36 (30-60min) and 5-HT (60min) but not CCK were observed during emesis. Pretreatment with the neuropeptide Y2 receptor antagonist JNJ-31020028 attenuated DON- and PYY-induced emesis, whereas the CCK1 receptor antagonist devezapide did not alter DON's emetic effects. The 5-HT3 receptor antagonist granisetron completely suppressed induction of vomiting by DON and the 5-HT inducer cisplatin. Granisetron pretreatment also partially blocked PYY3-36-induced emesis, suggesting a potential upstream role for this gut satiety hormone in 5-HT release. Taken together, the results suggest that both PYY3-36 and 5-HT play contributory roles in DON-induced emesis.
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Affiliation(s)
- Wenda Wu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, P.R. China
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85
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Iwasaki Y, Kakei M, Nakabayashi H, Ayush EA, Hirano-Kodaira M, Maejima Y, Yada T. Pancreatic polypeptide and peptide YY3-36 induce Ca2+ signaling in nodose ganglion neurons. Neuropeptides 2013; 47:19-23. [PMID: 22944736 DOI: 10.1016/j.npep.2012.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 06/18/2012] [Accepted: 07/09/2012] [Indexed: 01/08/2023]
Abstract
Peripheral injection of pancreatic polypeptide (PP) and peptide YY(3-36) (PYY(3-36)), the hormones released in response to meals, reduce food intake, in which the rank order of the potency is PP>PYY(3-36). These anorectic effects are abolished in abdominal vagotomized rats, suggesting that PP and PYY(3-36) induce anorexia via vagal afferent nerves. However, it is not clear whether PP and PYY(3-36) directly act on vagal afferent neurons. In this study, we examined the effects of PP and PYY(3-36) on cytosolic Ca(2+) concentration ([Ca(2+)](i)) in isolated nodose ganglion neurons of the mouse vagal afferent nerves. At 10(-11)M, PP but not PYY(3-36) recruited a significant population of nodose ganglion neurons into [Ca(2+)](i) increases. PP at 10(-11) to 10(-7) and PYY(3-36) at 10(-10) to 10(-7)M increased [Ca(2+)](i) in a concentration-dependent manner. At submaximal to maximal concentrations of 10(-10) and 10(-8)M, PP increased [Ca(2+)](i) in approximately twice greater population of nodose ganglion neurons than PYY(3-36). Furthermore, the majority of PP-responsive neurons also exhibited [Ca(2+)](i) responses to cholecystokinin-8, a hormone known to induce satiety through activating nodose ganglion neurons. The results demonstrate that PP and PYY(3-36) directly activate nodose ganglion neurons and suggest that the marked effect of PP on cholecystokinin-8-responsive nodose ganglion neurons could be linked to the regulation of feeding.
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Affiliation(s)
- Yusaku Iwasaki
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi 320-0498, Japan
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86
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Iwasaki Y, Yada T. Vagal afferents sense meal-associated gastrointestinal and pancreatic hormones: mechanism and physiological role. Neuropeptides 2012; 46:291-7. [PMID: 23020951 DOI: 10.1016/j.npep.2012.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 08/17/2012] [Accepted: 08/17/2012] [Indexed: 01/08/2023]
Abstract
Some gastrointestinal and pancreatic hormones are potently secreted by meal intake and reduce food intake, therefore these hormones play a role in the meal-evoked satiety peptides. Previous reports have demonstrated that peripheral administration of these gastrointestinal or pancreatic hormones decrease feeding and the anorectic effects are abolished by lesions of vagal afferent nerves using surgical or chemical protocols, indicative of the involvement of the vagal afferents. Vagal afferent nerves link between several peripheral organs and the nucleus tractus solitarius of the brainstem. The present review focuses on cholecystokinin, peptide YY(3-36), pancreatic polypeptide, and nesfatin-1 released from endocrine cells of the gut and pancreas. These hormonal peptides directly act on and increase cytosolic Ca(2+) in vagal afferent nodose ganglion neurons and finally suppress food intake via vagal afferents. Therefore, peripheral terminals of vagal afferents could sense gastrointestinal and pancreatic hormones and regulate food intake. Here, we review how the vagal afferent neurons sense a variety of gastrointestinal and pancreatic hormones and discuss its physiological significance in regulation of feeding.
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Affiliation(s)
- Yusaku Iwasaki
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, 3311-1, Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
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87
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Holzer P, Reichmann F, Farzi A. Neuropeptide Y, peptide YY and pancreatic polypeptide in the gut-brain axis. Neuropeptides 2012; 46:261-74. [PMID: 22979996 PMCID: PMC3516703 DOI: 10.1016/j.npep.2012.08.005] [Citation(s) in RCA: 325] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 08/04/2012] [Accepted: 08/09/2012] [Indexed: 02/06/2023]
Abstract
The gut-brain axis refers to the bidirectional communication between the gut and the brain. Four information carriers (vagal and spinal afferent neurons, immune mediators such as cytokines, gut hormones and gut microbiota-derived signalling molecules) transmit information from the gut to the brain, while autonomic neurons and neuroendocrine factors carry outputs from the brain to the gut. The members of the neuropeptide Y (NPY) family of biologically active peptides, NPY, peptide YY (PYY) and pancreatic polypeptide (PP), are expressed by cell systems at distinct levels of the gut-brain axis. PYY and PP are exclusively expressed by endocrine cells of the digestive system, whereas NPY is found at all levels of the gut-brain and brain-gut axis. The major systems expressing NPY comprise enteric neurons, primary afferent neurons, several neuronal pathways throughout the brain and sympathetic neurons. In the digestive tract, NPY and PYY inhibit gastrointestinal motility and electrolyte secretion and in this way modify the input to the brain. PYY is also influenced by the intestinal microbiota, and NPY exerts, via stimulation of Y1 receptors, a proinflammatory action. Furthermore, the NPY system protects against distinct behavioural disturbances caused by peripheral immune challenge, ameliorating the acute sickness response and preventing long-term depression. At the level of the afferent system, NPY inhibits nociceptive input from the periphery to the spinal cord and brainstem. In the brain, NPY and its receptors (Y1, Y2, Y4, Y5) play important roles in regulating food intake, energy homeostasis, anxiety, mood and stress resilience. In addition, PP and PYY signal to the brain to attenuate food intake, anxiety and depression-related behaviour. These findings underscore the important role of the NPY-Y receptor system at several levels of the gut-brain axis in which NPY, PYY and PP operate both as neural and endocrine messengers.
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Affiliation(s)
- Peter Holzer
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitätsplatz 4, A-8010 Graz, Austria.
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88
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Male mice that lack the G-protein-coupled receptor GPR41 have low energy expenditure and increased body fat content. Br J Nutr 2012; 109:1755-64. [PMID: 23110765 DOI: 10.1017/s0007114512003923] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
SCFA are produced in the gut by bacterial fermentation of undigested carbohydrates. Activation of the Gαi-protein-coupled receptor GPR41 by SCFA in β-cells and sympathetic ganglia inhibits insulin secretion and increases sympathetic outflow, respectively. A possible role in stimulating leptin secretion by adipocytes is disputed. In the present study, we investigated energy balance and glucose homoeostasis in GPR41 knockout mice fed on a standard low-fat or a high-fat diet. When fed on the low-fat diet, body fat mass was raised and glucose tolerance was impaired in male but not female knockout mice compared to wild-type mice. Soleus muscle and heart weights were reduced in the male mice, but total body lean mass was unchanged. When fed on the high-fat diet, body fat mass was raised in male but not female GPR41 knockout mice, but by no more in the males than when they were fed on the low-fat diet. Body lean mass and energy expenditure were reduced in male mice but not in female knockout mice. These results suggest that the absence of GPR41 increases body fat content in male mice. Gut-derived SCFA may raise energy expenditure and help to protect against obesity by activating GPR41.
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89
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Fazen CH, Kahkoska AR, Doyle RP. Expression and purification of human PYY(3–36) in Escherichia coli using a His-tagged small ubiquitin-like modifier fusion. Protein Expr Purif 2012; 85:51-9. [DOI: 10.1016/j.pep.2012.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 06/24/2012] [Accepted: 06/25/2012] [Indexed: 11/26/2022]
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90
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Zhang L, Nguyen AD, Lee ICJ, Yulyaningsih E, Riepler SJ, Stehrer B, Enriquez RF, Lin S, Shi YC, Baldock PA, Sainsbury A, Herzog H. NPY modulates PYY function in the regulation of energy balance and glucose homeostasis. Diabetes Obes Metab 2012; 14:727-36. [PMID: 22369253 DOI: 10.1111/j.1463-1326.2012.01592.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
AIMS Both the neuronal-derived neuropeptide Y (NPY) and the gut hormone peptide YY (PYY) have been implicated in the regulation of energy balance and glucose homeostasis. However, despite similar affinities for the same Y receptors, the co-ordinated actions of these two peptides in energy and glucose homeostasis remain largely unknown. METHODS To investigate the mechanisms and possible interactions between PYY with NPY in the regulation of these processes, we utilized NPY/PYY single and double mutant mouse models and examined parameters of energy balance and glucose homeostasis. RESULTS PYY(-/-) mice exhibited increased fasting-induced food intake, enhanced fasting and oral glucose-induced serum insulin levels, and an impaired insulin tolerance, - changes not observed in NPY(-/-) mice. Interestingly, whereas PYY deficiency-induced impairment in insulin tolerance remained in NPY(-/-) PYY(-/-) mice, effects of PYY deficiency on fasting-induced food intake and serum insulin concentrations at baseline and after the oral glucose bolus were absent in NPY(-/-) PYY(-/-) mice, suggesting that NPY signalling may be required for PYY's action on insulin secretion and fasting-induced hyperphagia. Moreover, NPY(-/-) PYY(-/-) , but not NPY(-/-) or PYY(-/-) mice had significantly decreased daily food intake, indicating interactive control by NPY and PYY on spontaneous food intake. Furthermore, both NPY(-/-) and PYY(-/-) mice showed significantly reduced respiratory exchange ratio during the light phase, with no additive effects observed in NPY(-/-) PYY(-/-) mice, indicating that NPY and PYY may regulate oxidative fuel selection via partly shared mechanisms. Overall, physical activity and energy expenditure, however, are not significantly altered by NPY and PYY single or double deficiencies. CONCLUSIONS These findings show significant and diverse interactions between NPY and PYY signalling in the regulation of different aspects of energy balance and glucose homeostasis.
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Affiliation(s)
- L Zhang
- Neuroscience Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, Sydney, New South Wales, Australia
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91
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Suzuki K, Jayasena CN, Bloom SR. Obesity and appetite control. EXPERIMENTAL DIABETES RESEARCH 2012; 2012:824305. [PMID: 22899902 PMCID: PMC3415214 DOI: 10.1155/2012/824305] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/20/2012] [Indexed: 01/01/2023]
Abstract
Obesity is one of the major challenges to human health worldwide; however, there are currently no effective pharmacological interventions for obesity. Recent studies have improved our understanding of energy homeostasis by identifying sophisticated neurohumoral networks which convey signals between the brain and gut in order to control food intake. The hypothalamus is a key region which possesses reciprocal connections between the higher cortical centres such as reward-related limbic pathways, and the brainstem. Furthermore, the hypothalamus integrates a number of peripheral signals which modulate food intake and energy expenditure. Gut hormones, such as peptide YY, pancreatic polypeptide, glucagon-like peptide-1, oxyntomodulin, and ghrelin, are modulated by acute food ingestion. In contrast, adiposity signals such as leptin and insulin are implicated in both short- and long-term energy homeostasis. In this paper, we focus on the role of gut hormones and their related neuronal networks (the gut-brain axis) in appetite control, and their potentials as novel therapies for obesity.
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Affiliation(s)
- Keisuke Suzuki
- Section of Investigative Medicine, Imperial College London, Commonwealth Building, Du Cane Road, London W12 0NN, UK
| | - Channa N. Jayasena
- Section of Investigative Medicine, Imperial College London, Commonwealth Building, Du Cane Road, London W12 0NN, UK
| | - Stephen R. Bloom
- Section of Investigative Medicine, Imperial College London, Commonwealth Building, Du Cane Road, London W12 0NN, UK
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92
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Shi YC, Hämmerle CM, Lee ICJ, Turner N, Nguyen AD, Riepler SJ, Lin S, Sainsbury A, Herzog H, Zhang L. Adult-onset PYY overexpression in mice reduces food intake and increases lipogenic capacity. Neuropeptides 2012; 46:173-82. [PMID: 22575886 DOI: 10.1016/j.npep.2012.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 12/22/2022]
Abstract
Peptide YY (PYY) is best known for its important role in appetite regulation, but recent pharmacological studies have suggested that PYY is also involved in regulating energy balance and glucose homeostasis. However, the mechanism behind the regulation of these parameters by PYY is less clear. Here, by utilising an inducible transgenic mouse model where PYY overexpression is induced in adult animals (PYYtg) and release of mature PYY peptides is controlled by endogenous machineries, we show that elevating PYY levels leads to reduced food intake after a 24-h fast. Furthermore, PYYtg mice, although not significantly different from WT with respect to body weight, adiposity, lean mass, physical activity or energy expenditure, exhibited a significantly increased respiratory exchange ratio (RER), indicating decreased lipid oxidation and/or increased lipogenesis. Importantly, PYYtg mice showed a 25% reduction in liver protein levels of phosphorylated acetyl-CoA carboxylase (pACC) in the absence of changes in total ACC levels compared to those of WT mice. Moreover, liver protein levels of AMP-activated kinase (AMPK) in PYYtg mice were 25% lower than those of WT mice, consistent with a reduced pACC in these mice. These data suggest that elevation of PYY levels as seen after a meal can increase lipogenic capacity, which is likely a key contributor to the increased RER seen in PYYtg mice. In addition, PYYtg mice exhibited comparable insulin tolerance and oral glucose tolerance to those of WT, but showed a trend towards decreased insulin levels in response to an oral glucose challenge, indicating that PYY could improve insulin action. Taken together, these findings demonstrate that under physiological conditions, PYY reduces food intake while enhancing lipogenic capacity and insulin action, likely contributing to fuel assimilation in the postprandial state.
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Affiliation(s)
- Yan-Chuan Shi
- Neuroscience Research Program, Garvan Institute of Medical Research, 384 Victoria St., Darlinghurst, Sydney, NSW 2010, Australia
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93
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Abstract
Obesity is one of the major challenges to human health worldwide; however, there are currently no effective pharmacological interventions for obesity. Recent studies have improved our understanding of energy homeostasis by identifying sophisticated neurohumoral networks which convey signals between the brain and gut in order to control food intake. The hypothalamus is a key region which possesses reciprocal connections between the higher cortical centres such as reward-related limbic pathways, and the brainstem. Furthermore, the hypothalamus integrates a number of peripheral signals which modulate food intake and energy expenditure. Gut hormones, such as peptide YY, pancreatic polypeptide, glucagon-like peptide-1, oxyntomodulin, and ghrelin, are modulated by acute food ingestion. In contrast, adiposity signals such as leptin and insulin are implicated in both short- and long-term energy homeostasis. In this paper, we focus on the role of gut hormones and their related neuronal networks (the gut-brain axis) in appetite control, and their potentials as novel therapies for obesity.
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94
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Wong IPL, Driessler F, Khor EC, Shi YC, Hörmer B, Nguyen AD, Enriquez RF, Eisman JA, Sainsbury A, Herzog H, Baldock PA. Peptide YY regulates bone remodeling in mice: a link between gut and skeletal biology. PLoS One 2012; 7:e40038. [PMID: 22792209 PMCID: PMC3391226 DOI: 10.1371/journal.pone.0040038] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 05/31/2012] [Indexed: 12/29/2022] Open
Abstract
Background & Aims Gastrointestinal peptides are increasingly being linked to processes controlling the maintenance of bone mass. Peptide YY (PYY), a gut-derived satiety peptide of the neuropeptide Y family, is upregulated in some states that also display low bone mass. Importantly, PYY has high affinity for Y-receptors, particularly Y1R and Y2R, which are known to regulate bone mass. Anorexic conditions and bariatric surgery for obesity influence circulating levels of PYY and have a negative impact on bone mass, but the precise mechanism behind this is unclear. We thus examined whether alterations in PYY expression affect bone mass. Methods Bone microstructure and cellular activity were analyzed in germline PYY knockout and conditional adult-onset PYY over-expressing mice at lumbar and femoral sites using histomorphometry and micro-computed tomography. Results PYY displayed a negative relationship with osteoblast activity. Male and female PYY knockout mice showed enhanced osteoblast activity, with greater cancellous bone mass. Conversely, PYY over-expression lowered osteoblast activity in vivo, via a direct Y1 receptor mediated mechanism involving MAPK stimulation evident in vitro. In contrast to PYY knockout mice, PYY over expression also altered bone resorption, as indicated by greater osteoclast surface, despite the lack of Y-receptor expression in osteoclastic cells. While evident in both sexes, cellular changes were generally more pronounced in females. Conclusions These data demonstrate that the gut peptide PYY is critical for the control of bone remodeling. This regulatory axis from the intestine to bone has the potential to contribute to the marked bone loss observed in situations of extreme weight loss and higher circulating PYY levels, such as anorexia and bariatric obesity surgery, and may be important in the maintenance of bone mass in the general population.
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Affiliation(s)
- Iris P. L. Wong
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Frank Driessler
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Ee Cheng Khor
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Yan-Chuan Shi
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Birgit Hörmer
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Amy D. Nguyen
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Ronaldo F. Enriquez
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - John A. Eisman
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Amanda Sainsbury
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Herbert Herzog
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Paul A. Baldock
- Neuroscience Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Osteoporosis and Bone Biology, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- * E-mail:
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95
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Tan TM, Field BCT, Minnion JS, Cuenco-Shillito J, Chambers ES, Zac-Varghese S, Brindley CJ, Mt-Isa S, Fiorentino F, Ashby D, Ward I, Ghatei MA, Bloom SR. Pharmacokinetics, adverse effects and tolerability of a novel analogue of human pancreatic polypeptide, PP 1420. Br J Clin Pharmacol 2012; 73:232-9. [PMID: 21834938 DOI: 10.1111/j.1365-2125.2011.04082.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
AIMS The objectives of this phase 1 study were to confirm the tolerability of single ascending subcutaneous doses of PP 1420 in healthy subjects, to assess its adverse effects and to investigate the drug's pharmacokinetics and dose proportionality. METHODS This was a double-blind, placebo-controlled, randomized study. There were three dosing periods. Each subject (n= 12) was randomized to receive one dose of placebo and two ascending doses of PP 1420, given as a subcutaneous injection. Blood samples were taken over 24 h to assess pharmacokinetics. Standard safety and laboratory data were collected. The primary endpoint was the tolerability of PP 1420. The secondary endpoint was exposure to PP 1420 as assessed by C(max) and AUC(0,∞). RESULTS PP 1420 was well tolerated by all subjects with no serious adverse effects. Following single subcutaneous doses of PP 1420 at 2, 4 and 8 mg to male subjects, C(max) was reached at a median t(max) of approximately 1 h post dose (range 0.32-2.00 h). Thereafter, plasma concentrations of PP 1420 declined with geometric mean apparent terminal elimination t(1/2) ranging from 2.42-2.61 h (range 1.64-3.95 h) across all dose levels. CONCLUSIONS Subcutaneous PP 1420 was well tolerated in healthy human subjects at single doses between 2-8 mg, with no tolerability issues arising. Where observed, adverse events were not serious, and there was no evidence of a dose-relationship to frequency of adverse events. The results therefore support the conduct of clinical trials to investigate efficacy, tolerability and pharmacokinetics during repeated dosing.
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Affiliation(s)
- Tricia M Tan
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London W12 0HS, UK
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96
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Heibel SK, Lopez GY, Panglao M, Sodha S, Mariño-Ramírez L, Tuchman M, Caldovic L. Transcriptional regulation of N-acetylglutamate synthase. PLoS One 2012; 7:e29527. [PMID: 22383952 PMCID: PMC3287996 DOI: 10.1371/journal.pone.0029527] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 11/30/2011] [Indexed: 01/13/2023] Open
Abstract
The urea cycle converts toxic ammonia to urea within the liver of mammals. At least 6 enzymes are required for ureagenesis, which correlates with dietary protein intake. The transcription of urea cycle genes is, at least in part, regulated by glucocorticoid and glucagon hormone signaling pathways. N-acetylglutamate synthase (NAGS) produces a unique cofactor, N-acetylglutamate (NAG), that is essential for the catalytic function of the first and rate-limiting enzyme of ureagenesis, carbamyl phosphate synthetase 1 (CPS1). However, despite the important role of NAGS in ammonia removal, little is known about the mechanisms of its regulation. We identified two regions of high conservation upstream of the translation start of the NAGS gene. Reporter assays confirmed that these regions represent promoter and enhancer and that the enhancer is tissue specific. Within the promoter, we identified multiple transcription start sites that differed between liver and small intestine. Several transcription factor binding motifs were conserved within the promoter and enhancer regions while a TATA-box motif was absent. DNA-protein pull-down assays and chromatin immunoprecipitation confirmed binding of Sp1 and CREB, but not C/EBP in the promoter and HNF-1 and NF-Y, but not SMAD3 or AP-2 in the enhancer. The functional importance of these motifs was demonstrated by decreased transcription of reporter constructs following mutagenesis of each motif. The presented data strongly suggest that Sp1, CREB, HNF-1, and NF-Y, that are known to be responsive to hormones and diet, regulate NAGS transcription. This provides molecular mechanism of regulation of ureagenesis in response to hormonal and dietary changes.
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Affiliation(s)
- Sandra Kirsch Heibel
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D. C., United States of America
- Molecular and Cellular Biology Program, University of Maryland, College Park, Maryland, United States of America
| | - Giselle Yvette Lopez
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Maria Panglao
- The George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Sonal Sodha
- Johns Hopkins School of Medicine in Baltimore, Maryland, United States of America
| | - Leonardo Mariño-Ramírez
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Mendel Tuchman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D. C., United States of America
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D. C., United States of America
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97
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Pyarokhil AH, Ishihara M, Sasaki M, Kitamura N. Immunohistochemical study on the ontogenetic development of the regional distribution of peptide YY, pancreatic polypeptide, and glucagon-like peptide 1 endocrine cells in bovine gastrointestinal tract. ACTA ACUST UNITED AC 2012; 175:15-20. [PMID: 22233836 DOI: 10.1016/j.regpep.2011.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 11/12/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
Abstract
The regional distribution and relative frequency of peptide YY (PYY)-, pancreatic polypeptide (PP)-, and glucagon-like peptide 1 (GLP-1)-immunoreactive (IR) cells were determined immunohistochemically in the gastrointestinal tract at seven ontogenetic stages in pre- and postnatal cattle. Different frequencies of PYY-, PP-, and GLP-1-IR cells were found in the intestines at all stages; they were not found in the esophagus and stomach. The frequencies varied depending on the intestinal segment and the developmental stage. The frequencies of PYY- and PP-IR cells were lower in the small intestine and increased from ileum to rectum, whereas GLP-1-IR cells were more numerous in duodenum and jejunum, decreased in ileum and cecum, and increased again in colon and rectum. The frequencies also varied according to pre- and postnatal stages. All three cell types were most numerous in fetus, and decreased in calf and adult groups, indicating that the frequencies of these three types of endocrine cells decrease with postnatal development. The results suggest that these changes vary depending on feeding habits and adaptation of growth, secretion, and motility of intestine at different ontogenetic stages of cattle.
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Affiliation(s)
- Asadullah Hamid Pyarokhil
- Laboratory of Veterinary Anatomy, Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
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98
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Abstract
Abstract The endocrine cells of the gastrointestinal (GI) tract and the pancreas, referred to as the enteroendocrine cells, secrete a large variety of peptides and amines that regulate functions of the digestive tract itself and of distant organs. Taken together, the enteroendocrine cells form the largest system of endocrine cells in the body, presently comprising 16 cell types. Many of them have been named after letters of the alphabet, but the names are only occasionally related to morphological or functional characteristics of the cell. In this review of the normal, adult, mammalian enteroendocrine cells, we summarize synonyms, functions, locations, structure, stored hormones/amines, receptors, and other cellular expressions. We propose that the enteroendocrine cells should be renamed after their most well-known hormone/amine and, when applicable, their anatomical location, with opportunities for future revisions.
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Affiliation(s)
- Herbert F Helander
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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99
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Greenwood HC, Bloom SR, Murphy KG. Peptides and their potential role in the treatment of diabetes and obesity. Rev Diabet Stud 2011; 8:355-68. [PMID: 22262073 DOI: 10.1900/rds.2011.8.355] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It is estimated that 347 million people worldwide have diabetes and that over 1.5 billion adults worldwide are overweight. Predictions suggest these rates are increasing. Diabetes is a common complication in overweight and obese subjects, and in 2004, an estimated 3.4 million people died from consequences of high blood sugar. Thus, there is great interest in revealing the physiological systems that regulate body weight and blood sugar. Several peptidergic systems within the central nervous system and the periphery regulate energy homeostasis. A number of these systems have been investigated as potential treatments for obesity and the metabolic syndrome. However, manipulation of peptidergic systems poses many problems. This review discusses the peptidergic systems currently attracting research interest for their clinical potential to treat obesity. We consider first neuropeptides in the brain, including the orexigenic neuropeptide Y and melanin-concentrating hormone, and anorectic factors such as the melanocortins, ciliary neurotrophic factor, and neuromedin U. We subsequently discuss the utility of targeting peripheral gut peptides, including pancreatic polypeptide, peptide YY, amylin, and the gastric hormone ghrelin. Also, we analyze the evidence that these factors or drugs based on them may be therapeutically useful, while considering the disadvantages of using such peptides in a clinical context.
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Affiliation(s)
- Hannah C Greenwood
- Section of Investigative Medicine, Department of Medicine, Imperial College London, London, UK
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100
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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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