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Rea JJ, Liu CM, Hayes AMR, Bashaw AG, Schwartz G, Ohan R, Décarie-Spain L, Kao AE, Klug ME, Phung KJ, Waldow AI, Wood RI, Kanoski SE. Hippocampus oxytocin signaling promotes prosocial eating in rats. Biol Psychiatry 2024:S0006-3223(24)01462-8. [PMID: 39038641 DOI: 10.1016/j.biopsych.2024.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 07/07/2024] [Accepted: 07/12/2024] [Indexed: 07/24/2024]
Abstract
BACKGROUND Oxytocin (OT) is a hypothalamic neuropeptide involved in diverse physiological and behavioral functions, including social-based behavior and food intake control. The extent that OT's role in regulating these two fundamental behaviors is interconnected is unknown and is a critical gap given that social factors have a strong influence on eating behavior in mammals. Here we focus on OT signaling in the dorsal hippocampus (HPCd), a brain region recently linked with eating and social memory, as a candidate system where these functions overlap. METHODS HPCd OT signaling gain- and loss-of-function strategies were employed in male Sprague-Dawley rats that were trained in a novel social eating procedure to consume their first nocturnal meal under conditions that vary with regards to conspecific presence and familiarity. The endogenous role of HPCd OT signaling was also evaluated for olfactory-based social transmission of food preference learning, sociality, and social recognition memory. RESULTS HPCd OT administration had no effect on food intake under isolated conditions, yet significantly increased consumption in the presence of a familiar, but not an unfamiliar conspecific. Supporting these results, chronic knockdown of HPCd OT receptor expression eliminated the food intake-promoting effects of a familiar conspecific. HPCd OT receptor knockdown also blocked social transmission of food preference learning and impaired social recognition memory without affecting sociality. CONCLUSION Collective results identify endogenous HPCd OT signaling as a novel substrate where OT synergistically influences eating and social behaviors, including the social facilitation of eating and the social transmission of food preference.
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Affiliation(s)
- Jessica J Rea
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA; Neuroscience Graduate Program, University of Southern California, USA
| | - Clarissa M Liu
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA; Neuroscience Graduate Program, University of Southern California, USA
| | - Anna M R Hayes
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Alexander G Bashaw
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA; Neuroscience Graduate Program, University of Southern California, USA
| | - Grace Schwartz
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Rita Ohan
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Léa Décarie-Spain
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Alicia E Kao
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Molly E Klug
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Kenneth J Phung
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Alice I Waldow
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA
| | - Ruth I Wood
- Neuroscience Graduate Program, University of Southern California, USA; Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, USA
| | - Scott E Kanoski
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, USA; Neuroscience Graduate Program, University of Southern California, USA.
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Gruber T, Lechner F, Krieger JP, García-Cáceres C. Neuroendocrine gut-brain signaling in obesity. Trends Endocrinol Metab 2024:S1043-2760(24)00120-6. [PMID: 38821753 DOI: 10.1016/j.tem.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/29/2024] [Accepted: 05/03/2024] [Indexed: 06/02/2024]
Abstract
The past decades have witnessed the rise and fall of several, largely unsuccessful, therapeutic attempts to bring the escalating obesity pandemic to a halt. Looking back to look ahead, the field has now put its highest hopes in translating insights from how the gastrointestinal (GI) tract communicates with the brain to calibrate behavior, physiology, and metabolism. A major focus of this review is to summarize the latest advances in comprehending the neuroendocrine aspects of this so-called 'gut-brain axis' and to explore novel concepts, cutting-edge technologies, and recent paradigm-shifting experiments. These exciting insights continue to refine our understanding of gut-brain crosstalk and are poised to promote the development of additional therapeutic avenues at the dawn of a new era of antiobesity therapeutics.
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Affiliation(s)
- Tim Gruber
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI 49506, USA; Department of Epigenetics, Van Andel Institute, Grand Rapids, MI 49506, USA; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
| | - Franziska Lechner
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - Jean-Philippe Krieger
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich-Vetsuisse, 8057 Zurich, Switzerland; Institute of Neuroscience and Physiology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Cristina García-Cáceres
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, 80336 Munich, Germany.
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Iovino M, Messana T, Marucci S, Triggiani D, Giagulli VA, Guastamacchia E, Piazzolla G, De Pergola G, Lisco G, Triggiani V. The neurohypophyseal hormone oxytocin and eating behaviors: a narrative review. Hormones (Athens) 2024; 23:15-23. [PMID: 37979096 PMCID: PMC10847364 DOI: 10.1007/s42000-023-00505-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND The neuropeptide oxytocin (OT) is crucial in several conditions, such as lactation, parturition, mother-infant interaction, and psychosocial function. Moreover, OT may be involved in the regulation of eating behaviors. METHODS This review briefly summarizes data concerning the role of OT in eating behaviors. Appropriate keywords and medical subject headings were identified and searched for in PubMed/MEDLINE. References of original articles and reviews were screened, examined, and selected. RESULTS Hypothalamic OT-secreting neurons project to different cerebral areas controlling eating behaviors, such as the amygdala, area postrema, nucleus of the solitary tract, and dorsal motor nucleus of the vagus nerve. Intracerebral/ventricular OT administration decreases food intake and body weight in wild and genetically obese rats. OT may alter food intake and the quality of meals, especially carbohydrates and sweets, in humans. DISCUSSION OT may play a role in the pathophysiology of eating disorders with potential therapeutic perspectives. In obese patients and those with certain eating disorders, such as bulimia nervosa or binge/compulsive eating, OT may reduce appetite and caloric consumption. Conversely, OT administered to patients with anorexia nervosa may paradoxically stimulate appetite, possibly by lowering anxiety which usually complicates the management of these patients. Nevertheless, OT administration (e.g., intranasal route) is not always associated with clinical benefit, probably because intranasally administered OT fails to achieve therapeutic intracerebral levels of the hormone. CONCLUSION OT administration could play a therapeutic role in managing eating disorders and disordered eating. However, specific studies are needed to clarify this issue with regard to dose-finding and route and administration time.
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Affiliation(s)
- Michele Iovino
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy
| | - Tullio Messana
- Infantile Neuropsychiatry, IRCCS - Institute of Neurological Sciences, Bologna, Italy
| | - Simonetta Marucci
- Università Campus Biomedico, Dip. "Scienze e Tecnologie per l'Uomo e l'ambiente", Via Alvaro del Portillo, 21, Roma, Italy
| | - Domenico Triggiani
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy
| | - Vito Angelo Giagulli
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy
| | - Edoardo Guastamacchia
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy
| | - Giuseppina Piazzolla
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy
| | - Giovanni De Pergola
- National Institute of Gastroenterology IRCCS "Saverio de Bellis", Research Hospital, Castellana Grotte, Bari, Italy
- Department of Biomedical Science and Human Oncology, University of Bari, School of Medicine, Bari, Apulia, Italy
| | - Giuseppe Lisco
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy.
| | - Vincenzo Triggiani
- Interdisciplinary Department of Medicine, Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Bari, Apulia, Italy
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4
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Gruber T, Lechner F, Murat C, Contreras RE, Sanchez-Quant E, Miok V, Makris K, Le Thuc O, González-García I, García-Clave E, Althammer F, Krabichler Q, DeCamp LM, Jones RG, Lutter D, Williams RH, Pfluger PT, Müller TD, Woods SC, Pospisilik JA, Martinez-Jimenez CP, Tschöp MH, Grinevich V, García-Cáceres C. High-calorie diets uncouple hypothalamic oxytocin neurons from a gut-to-brain satiation pathway via κ-opioid signaling. Cell Rep 2023; 42:113305. [PMID: 37864798 PMCID: PMC10636643 DOI: 10.1016/j.celrep.2023.113305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/21/2023] [Accepted: 10/04/2023] [Indexed: 10/23/2023] Open
Abstract
Oxytocin-expressing paraventricular hypothalamic neurons (PVNOT neurons) integrate afferent signals from the gut, including cholecystokinin (CCK), to adjust whole-body energy homeostasis. However, the molecular underpinnings by which PVNOT neurons orchestrate gut-to-brain feeding control remain unclear. Here, we show that mice undergoing selective ablation of PVNOT neurons fail to reduce food intake in response to CCK and develop hyperphagic obesity on a chow diet. Notably, exposing wild-type mice to a high-fat/high-sugar (HFHS) diet recapitulates this insensitivity toward CCK, which is linked to diet-induced transcriptional and electrophysiological aberrations specifically in PVNOT neurons. Restoring OT pathways in diet-induced obese (DIO) mice via chemogenetics or polypharmacology sufficiently re-establishes CCK's anorexigenic effects. Last, by single-cell profiling, we identify a specialized PVNOT neuronal subpopulation with increased κ-opioid signaling under an HFHS diet, which restrains their CCK-evoked activation. In sum, we document a (patho)mechanism by which PVNOT signaling uncouples a gut-brain satiation pathway under obesogenic conditions.
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Affiliation(s)
- Tim Gruber
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI 49506, USA; Department of Epigenetics, Van Andel Institute, Grand Rapids, MI 49506, USA.
| | - Franziska Lechner
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Cahuê Murat
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Raian E Contreras
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Eva Sanchez-Quant
- Helmholtz Pioneer Campus (HPC), Helmholtz Zentrum München, Neuherberg, Germany
| | - Viktorian Miok
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Konstantinos Makris
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Computational Discovery Research, Institute for Diabetes and Obesity (IDO), Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Ophélia Le Thuc
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Ismael González-García
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Elena García-Clave
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | | | - Quirin Krabichler
- Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Lisa M DeCamp
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI 49506, USA
| | - Russell G Jones
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI 49506, USA
| | - Dominik Lutter
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Computational Discovery Research, Institute for Diabetes and Obesity (IDO), Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Rhiannan H Williams
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute for Neurogenomics, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Paul T Pfluger
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Research Unit NeuroBiology of Diabetes, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Neurobiology of Diabetes, TUM School of Medicine, Technical University Munich, 80333 Munich, Germany
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Department of Pharmacology and Experimental Therapy, Institute for Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls Hospitals and Clinics, Tübingen, Germany
| | - Stephen C Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA
| | - John Andrew Pospisilik
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI 49506, USA; Department of Epigenetics, Van Andel Institute, Grand Rapids, MI 49506, USA
| | - Celia P Martinez-Jimenez
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI 49506, USA; TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Division of Metabolic Diseases, Department of Medicine, Technische Universität, Munich, Germany
| | - Valery Grinevich
- Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; Center for Neuroinflammation and Cardiometabolic Diseases, Georgia State University, Atlanta, GA, USA.
| | - Cristina García-Cáceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, 80336 Munich, Germany.
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5
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Wald HS, Ghidewon MY, Hayes MR, Grill HJ. Hindbrain ghrelin and liver-expressed antimicrobial peptide 2, ligands for growth hormone secretagogue receptor, bidirectionally control food intake. Am J Physiol Regul Integr Comp Physiol 2023; 324:R547-R555. [PMID: 36847494 PMCID: PMC10069974 DOI: 10.1152/ajpregu.00232.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/26/2023] [Accepted: 02/16/2023] [Indexed: 03/01/2023]
Abstract
Hindbrain growth hormone secretagogue receptor (GHSR) agonism increases food intake, yet the underlying neural mechanisms remain unclear. The functional effects of hindbrain GHSR antagonism by its endogenous antagonist liver-expressed antimicrobial peptide 2 (LEAP2) are also yet unexplored. To test the hypothesis that hindbrain GHSR agonism attenuates the food intake inhibitory effect of gastrointestinal (GI) satiation signals, ghrelin (at a feeding subthreshold dose) was administered to the fourth ventricle (4V) or directly to the nucleus tractus solitarius (NTS) before systemic delivery of the GI satiation signal cholecystokinin (CCK). Also examined, was whether hindbrain GHSR agonism attenuated CCK-induced NTS neural activation (c-Fos immunofluorescence). To investigate an alternate hypothesis that hindbrain GHSR agonism enhances feeding motivation and food seeking, intake stimulatory ghrelin doses were administered to the 4V and fixed ratio 5 (FR-5), progressive ratio (PR), and operant reinstatement paradigms for palatable food responding were evaluated. Also assessed were 4V LEAP2 delivery on food intake and body weight (BW) and on ghrelin-stimulated feeding. Both 4V and NTS ghrelin blocked the intake inhibitory effect of CCK and 4V ghrelin blocked CCK-induced NTS neural activation. Although 4V ghrelin increased low-demand FR-5 responding, it did not increase high-demand PR or reinstatement of operant responding. Fourth ventricle LEAP2 reduced chow intake and BW and blocked hindbrain ghrelin-stimulated feeding. Data support a role for hindbrain GHSR in bidirectional control of food intake through mechanisms that include interacting with the NTS neural processing of GI satiation signals but not food motivation and food seeking.
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Affiliation(s)
- Hallie S Wald
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Misgana Y Ghidewon
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Matthew R Hayes
- Department of Psychiatry, Institute of Diabetes Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Harvey J Grill
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Kobashi M, Shimatani Y, Fujita M. Oxytocin increased intragastric pressure in the forestomach of rats via the dorsal vagal complex. Physiol Behav 2023; 261:114087. [PMID: 36646162 DOI: 10.1016/j.physbeh.2023.114087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
We previously reported that appetite-enhancing peptides facilitated phasic contractions of the distal stomach and relaxed the forestomach via the dorsal vagal complex (DVC). The present study investigated the effects of anorectic substances on gastric reservoir function. The effects of oxytocin on the motility of the forestomach were examined in rats anesthetized with urethane-chloralose. Gastric motor responses were measured using an intragastric balloon. The fourth ventricular administration of oxytocin (0.1 - 1.0 nmol) increased intragastric pressure (IGP) in the forestomach in a dose-dependent manner. Conversely, the administration of oxytocin (0.3 nmol) suppressed phasic contractions of the distal stomach. These responses were opposite to those of appetite-enhancing peptides in previous studies. The oxytocin response in the forestomach was not observed after bilateral cervical vagotomy. The effects of oxytocin on forestomach motility were examined in animals that underwent ablation of the area postrema (AP) to clarify its involvement. Although the magnitude of the response to the fourth ventricular administration of oxytocin decreased, a significant response was still observed. A microinjection of oxytocin (3 pmol) into the AP, the left medial nucleus of the nucleus tractus solitarius (mNTS), the left commissural part of the NTS, or the left dorsal motor nucleus of the vagus was performed. The oxytocin injection into the AP and/or mNTS induced a rapid and large increase in IGP in the forestomach. Prior injection of L-368,899, an oxytocin receptor antagonist, into both the AP and mNTS attenuated the oxytocin response of the forestomach induced by fourth ventricular administration of oxytocin. These results indicate that oxytocin acts on the AP and/or mNTS to increase IGP in the forestomach via vagal preganglionic neurons.
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Affiliation(s)
- Motoi Kobashi
- Department of Oral Physiology, Faculty of Medicine, Dentistry and Pharmaceutical Science, Okayama University, Okayama, 700-8525, Japan.
| | - Yuichi Shimatani
- Department of Medical Engineering, Faculty of Engineering, Tokyo City University, Tokyo, 158-8557, Japan
| | - Masako Fujita
- Department of Oral Physiology, Faculty of Medicine, Dentistry and Pharmaceutical Science, Okayama University, Okayama, 700-8525, Japan
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7
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Buemann B. Oxytocin Release: A Remedy for Cerebral Inflammaging. Curr Aging Sci 2022; 15:218-228. [PMID: 35431008 DOI: 10.2174/1874609815666220414104832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/22/2021] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Oxytocin facilitates reproduction both by physiological and behavioral mechanisms. Oxytocinergic neurons emerging from the hypothalamus release oxytocin from the pituitary gland to the blood by axonal discharge to regulate reproductive organs. However, at the same time, oxytocin is secreted into neighboring areas of the hypothalamus from the dendrites of these neurons. Here, the peptide acts by autocrine and paracrine mechanisms to influence other neuroendocrine systems. Furthermore, oxytocinergic neurons project to many different locations in the brain, where they affect sensory processing, affective functions, and reward. Additional to its regulatory role, significant anti-inflammatory and restoring effects of oxytocin have been reported from many invivo and in-vitro studies. The pervasive property of the oxytocin system may enable it generally to dampen stress reactions both peripherally and centrally, and protect neurons and supportive cells from inadequate inflammation and malfunctioning. Animal experiments have documented the importance of preserving immune- and stem cell functions in the hypothalamus to impede age-related destructive processes of the body. Sexual reward has a profound stimulating impact on the oxytocinergic activity, and the present article therefore presents the hypothesis that frequent sexual activity and gratigying social experiance may postpone the onset of frailty and age-associated diseases by neural protection from the bursts of oxytocin. Furthermore, suggestions are given how the neuroplastic properties of oxytocin may be utilized to enhance sexual reward by learning processes in order to further reinforce the release of this peptide.
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Affiliation(s)
- Benjamin Buemann
- Retired. Copenhagen, Denmark. Previous Affiliation: Research Department of Human Nutrition, The Royal Veterinary and Agricultural University, Copenhagen, Denmark
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Changes in Endogenous Oxytocin Levels and the Effects of Exogenous Oxytocin Administration on Body Weight Changes and Food Intake in Polycystic Ovary Syndrome Model Rats. Int J Mol Sci 2022; 23:ijms23158207. [PMID: 35897783 PMCID: PMC9330807 DOI: 10.3390/ijms23158207] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/24/2022] [Accepted: 07/24/2022] [Indexed: 12/10/2022] Open
Abstract
Polycystic ovary syndrome (PCOS) is frequently seen in females of reproductive age and is associated with metabolic disorders that are exacerbated by obesity. Although body weight reduction programs via diet and lifestyle changes are recommended for modifying reproductive and metabolic phenotypes, the drop-out rate is high. Thus, an efficacious, safe, and continuable treatment method is needed. Recent studies have shown that oxytocin (OT) reduces body weight gain and food intake, and promotes lipolysis in some mammals, including humans (especially obese individuals), without any adverse effects. In the present study, we evaluated the changes in endogenous OT levels, and the effects of acute and chronic OT administration on body weight changes, food intake, and fat mass using novel dihydrotestosterone-induced PCOS model rats. We found that the serum OT level was lower in PCOS model rats than in control rats, whereas the hypothalamic OT mRNA expression level did not differ between them. Acute intraperitoneal administration of OT during the dark phase reduced the body weight gain and food intake in PCOS model rats, but these effects were not observed in control rats. In contrast, chronic administration of OT decreased the food intake in both the PCOS model rats and control rats. These findings indicate that OT may be a candidate medicine that is efficacious, safe, and continuable for treating obese PCOS patients.
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Ye Q, Nunez J, Zhang X. Oxytocin Receptor-Expressing Neurons in the Paraventricular Thalamus Regulate Feeding Motivation through Excitatory Projections to the Nucleus Accumbens Core. J Neurosci 2022; 42:3949-3964. [PMID: 35387870 PMCID: PMC9097779 DOI: 10.1523/jneurosci.2042-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 11/21/2022] Open
Abstract
Oxytocin receptors (OTR) have been found in the paraventricular thalamus (PVT) for the regulation of feeding and maternal behaviors. However, the functional projections of OTR-expressing PVT neurons remain largely unknown. Here, we used chemogenetic and optogenetic tools to test the role of OTR-expressing PVT neurons and their projections in the regulation of food intake in both male and female OTR-Cre mice. We found chemogenetic activation of OTR-expressing PVT neurons promoted food seeking under trials with a progressive ratio schedule of reinforcement. Using Feeding Experimentation Devices for real-time meal measurements, we found chemogenetic activation of OTR-expressing PVT neurons increased meal frequency but not cumulative food intake because of a compensatory decrease in meal sizes. In combination with anterograde neural tracing and slice patch-clamp recordings, we found optogenetic stimulation of PVT OTR terminals excited neurons in the posterior basolateral amygdala (pBLA) and nucleus accumbens core (NAcC) as well as local PVT neurons through monosynaptic glutamatergic transmissions. Photostimulation of OTR-expressing PVT-NAcC projections promoted food-seeking, whereas selective activation of PVT-pBLA projections produced little effect on feeding. In contrast to selective activation of OTR terminals, photostimulation of a broader population of glutamatergic PVT terminals exerted direct excitation followed by indirect lateral inhibition on neurons in both NAcC and anterior basolateral amygdala. Together, these results suggest that OTR-expressing PVT neurons are a distinct population of PVT glutamate neurons that regulate feeding motivation through projections to NAcC.SIGNIFICANCE STATEMENT The paraventricular thalamus plays an important role in the regulation of feeding motivation. However, because of the diversity of paraventricular thalamic neurons, the specific neuron types promoting food motivation remain elusive. In this study, we provide evidence that oxytocin receptor-expressing neurons are a specific group of glutamate neurons that primarily project to the nucleus accumbens core and posterior amygdala. We found that activation of these neurons promotes the motivation for food reward and increases meal frequency through projections to the nucleus accumbens core but not the posterior amygdala. As a result, we postulate that oxytocin receptor-expressing neurons in the paraventricular thalamus and their projections to the nucleus accumbens core mainly regulate feeding motivation but not food consumption.
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Affiliation(s)
- Qiying Ye
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| | - Jeremiah Nunez
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| | - Xiaobing Zhang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
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10
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Levine AS, Jewett DC, Kotz CM, Olszewski PK. Behavioral plasticity: Role of neuropeptides in shaping feeding responses. Appetite 2022; 174:106031. [PMID: 35395362 DOI: 10.1016/j.appet.2022.106031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/12/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022]
Abstract
Behavioral plasticity refers to changes occurring due to external influences on an organism, including adaptation, learning, memory and enduring influences from early life experience. There are 2 types of behavioral plasticity: "developmental", which refers to gene/environment interactions affecting a phenotype, and "activational" which refers to innate physiology and can involve structural physiological changes of the body. In this review, we focus on feeding behavior, and studies involving neuropeptides that influence behavioral plasticity - primarily opioids, orexin, neuropeptide Y, and oxytocin. In each section of the review, we include examples of behavioral plasticity as it relates to actions of these neuropeptides. It can be concluded from this review that eating behavior is influenced by a number of external factors, including time of day, type of food available, energy balance state, and stressors. The reviewed work underscores that environmental factors play a critical role in feeding behavior and energy balance, but changes in eating behavior also result from a multitude of non-environmental factors, such that there can be no single mechanism or variable that can explain ingestive behavior.
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Affiliation(s)
- Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA.
| | - David C Jewett
- Department of Psychology, University of Wisconsin-Eau Claire, Eau Claire, WI, USA
| | - Catherine M Kotz
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Geriatric, Research, Education and Clinical Center, Minneapolis Veterans Affairs Health, Minneapolis, MN, 55417, USA
| | - Pawel K Olszewski
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA; Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Faculty of Science and Engineering, University of Waikato, Hamilton, 3240, New Zealand
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11
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Sucrose intake by rats affected by both intraperitoneal oxytocin administration and time of day. Psychopharmacology (Berl) 2022; 239:429-442. [PMID: 34731267 DOI: 10.1007/s00213-021-06014-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/20/2021] [Indexed: 10/19/2022]
Abstract
RATIONALE Daily limited access to palatable food or drink at a fixed time is commonly used in rodent models of bingeing. Under these conditions, entrainment may modulate intake patterns. Oxytocin is involved in circadian patterns of intake and, when administered peripherally, reduces sucrose intake. However, oxytocin's effects on intake under limited-access conditions and its potential interaction with entrainment have not been explored. OBJECTIVES This study examined the role of entrainment on intake patterns, oxytocin's effects on sucrose intakes and locomotor activity and whether oxytocin's effects were mediated by its actions at the oxytocin receptor. METHODS Sated rats received daily 1-h access to 10% sucrose solution either at a fixed or varied time of day. Rats received intraperitoneal oxytocin (0 mg/kg, 0.3 mg/kg, 1 mg/kg, 3 mg/kg) prior to sucrose access, and spontaneous locomotor activity was assessed in an open-field test. Rats were then pre-treated with an oxytocin receptor antagonist, L368,899, prior to oxytocin before sucrose access. RESULTS Intake patterns did not differ between fixed- or varied-time presentations; rats consumed more sucrose solution in the middle as opposed to the early-dark phase. Oxytocin dose-dependently reduced sucrose intakes, but also reduced locomotor activity. There was some evidence of partial blockade of oxytocin-induced sucrose intake reductions by L368,899, but the results were unclear. CONCLUSIONS Time of day and oxytocin impact sucrose solution intake under daily limited access in rats and the sedative-like effects of oxytocin should be considered in future studies on oxytocin and food intake.
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Dimitri P. Treatment of Acquired Hypothalamic Obesity: Now and the Future. Front Endocrinol (Lausanne) 2022; 13:846880. [PMID: 35464063 PMCID: PMC9019363 DOI: 10.3389/fendo.2022.846880] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
The hypothalamus is the centre of neuroendocrine regulation of energy homeostasis and appetite. Maldevelopment of, or damage to, the key hypothalamic nuclei disrupts the coordinated balance between energy intake and expenditure leading, to rapid and excessive weight gain. Hypothalamic obesity is compounded by a disruption of the hypothalamic-pituitary axis, sleep disruption, visual compromise, and neurological and vascular sequalae. Amongst suprasellar tumors, craniopharyngioma is the most common cause of acquired hypothalamic obesity, either directly or following surgical or radiotherapeutic intervention. At present, therapy is limited to strategies to manage obesity but with a modest and variable impact. Current approaches include optimizing pituitary hormone replacement, calorie restriction, increased energy expenditure through physical activity, behavioral interventions, pharmacotherapy and bariatric surgery. Current pharmacotherapeutic approaches include stimulants that increase energy consumption, anti-diabetic agents, hypothalamic-pituitary substitution therapy, octreotide, and methionine aminopeptidase 2 (MetAP2) inhibitors. Some pharmacological studies of hypothalamic obesity report weight loss or stabilization but reported intervention periods are short, and others report no effect. The impact of bariatric surgery on weight loss in hypothalamic obesity again is variable. Novel or combined approaches to manage hypothalamic obesity are thus required to achieve credible and sustained weight loss. Identifying etiological factors contributing hypothalamic obesity may lead to multi-faceted interventions targeting hyperphagia, insulin resistance, decreased energy expenditure, sleep disturbance, hypopituitarism and psychosocial morbidity. Placebo-controlled trials using current single, or combination therapies are required to determine the impact of therapeutic agents. A well-defined approach to defining the location of hypothalamic damage may support the use of future targeted therapies. Intranasal oxytocin is currently being investigated as an anorexogenic agent. Novel agents including those targeting pro-opimelanocortin-C and AgRP/NPY expressing neurons and the MC4 receptor may result in better outcomes. This article discusses the current challenges in the management of hypothalamic obesity in children and young people and future therapeutic approaches to increasing weight loss and quality of life in these patients.
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Affiliation(s)
- Paul Dimitri
- The Department of Paediatric Endocrinology, Sheffield Children’s NHS Foundation Trust, Sheffield, United Kingdom
- College of Health, Wellbeing and Life Sciences, Sheffield Hallam University, Sheffield, United Kingdom
- *Correspondence: Paul Dimitri,
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13
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Niu J, Tong J, Blevins JE. Oxytocin as an Anti-obesity Treatment. Front Neurosci 2021; 15:743546. [PMID: 34720864 PMCID: PMC8549820 DOI: 10.3389/fnins.2021.743546] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/16/2021] [Indexed: 12/19/2022] Open
Abstract
Obesity is a growing health concern, as it increases risk for heart disease, hypertension, type 2 diabetes, cancer, COVID-19 related hospitalizations and mortality. However, current weight loss therapies are often associated with psychiatric or cardiovascular side effects or poor tolerability that limit their long-term use. The hypothalamic neuropeptide, oxytocin (OT), mediates a wide range of physiologic actions, which include reproductive behavior, formation of prosocial behaviors and control of body weight. We and others have shown that OT circumvents leptin resistance and elicits weight loss in diet-induced obese rodents and non-human primates by reducing both food intake and increasing energy expenditure (EE). Chronic intranasal OT also elicits promising effects on weight loss in obese humans. This review evaluates the potential use of OT as a therapeutic strategy to treat obesity in rodents, non-human primates, and humans, and identifies potential mechanisms that mediate this effect.
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Affiliation(s)
- JingJing Niu
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - Jenny Tong
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
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Anekonda VT, Thompson BW, Ho JM, Roberts ZS, Edwards MM, Nguyen HK, Dodson AD, Wolden-Hanson T, Chukri DW, Herbertson AJ, Graham JL, Havel PJ, Wietecha TA, O’Brien KD, Blevins JE. Hindbrain Administration of Oxytocin Reduces Food Intake, Weight Gain and Activates Catecholamine Neurons in the Hindbrain Nucleus of the Solitary Tract in Rats. J Clin Med 2021; 10:5078. [PMID: 34768597 PMCID: PMC8584350 DOI: 10.3390/jcm10215078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 11/16/2022] Open
Abstract
Existing studies show that CNS oxytocin (OT) signaling is important in the control of energy balance, but it is unclear which neurons may contribute to these effects. Our goals were to examine (1) the dose-response effects of acute OT administration into the third (3V; forebrain) and fourth (4V; hindbrain) ventricles to assess sensitivity to OT in forebrain and hindbrain sites, (2) the extent to which chronic 4V administration of OT reduces weight gain associated with the progression of diet-induced obesity, and (3) whether nucleus tractus solitarius (NTS) catecholamine neurons are downstream targets of 4V OT. Initially, we examined the dose-response effects of 3V and 4V OT (0.04, 0.2, 1, or 5 μg). 3V and 4V OT (5 μg) suppressed 0.5-h food intake by 71.7 ± 6.0% and 60 ± 12.9%, respectively. 4V OT (0.04, 0.2, 1 μg) reduced food intake by 30.9 ± 12.9, 42.1 ± 9.4, and 56.4 ± 9.0%, respectively, whereas 3V administration of OT (1 μg) was only effective at reducing 0.5-h food intake by 38.3 ± 10.9%. We subsequently found that chronic 4V OT infusion, as with chronic 3V infusion, reduced body weight gain (specific to fat mass) and tended to reduce plasma leptin in high-fat diet (HFD)-fed rats, in part, through a reduction in energy intake. Lastly, we determined that 4V OT increased the number of hindbrain caudal NTS Fos (+) neurons (156 ± 25) relative to vehicle (12 ± 3). The 4V OT also induced Fos in tyrosine hydroxylase (TH; marker of catecholamine neurons) (+) neurons (25 ± 7%) relative to vehicle (0.8 ± 0.3%). Collectively, these findings support the hypothesis that OT within the hindbrain is effective at reducing food intake, weight gain, and adiposity and that NTS catecholamine neurons in addition to non-catecholaminergic neurons are downstream targets of CNS OT.
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Affiliation(s)
- Vishwanath T. Anekonda
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Benjamin W. Thompson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Jacqueline M. Ho
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA;
| | - Zachary S. Roberts
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Melise M. Edwards
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Ha K. Nguyen
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Andrew D. Dodson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Tami Wolden-Hanson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Daniel W. Chukri
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Adam J. Herbertson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - James L. Graham
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (J.L.G.); (P.J.H.)
| | - Peter J. Havel
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (J.L.G.); (P.J.H.)
| | - Tomasz A. Wietecha
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA;
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA 98109, USA;
| | - Kevin D. O’Brien
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA 98109, USA;
- Division of Cardiology, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - James E. Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA;
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Oxytocin and Food Intake Control: Neural, Behavioral, and Signaling Mechanisms. Int J Mol Sci 2021; 22:ijms221910859. [PMID: 34639199 PMCID: PMC8509519 DOI: 10.3390/ijms221910859] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 09/29/2021] [Accepted: 10/03/2021] [Indexed: 11/16/2022] Open
Abstract
The neuropeptide oxytocin is produced in the paraventricular hypothalamic nucleus and the supraoptic nucleus of the hypothalamus. In addition to its extensively studied influence on social behavior and reproductive function, central oxytocin signaling potently reduces food intake in both humans and animal models and has potential therapeutic use for obesity treatment. In this review, we highlight rodent model research that illuminates various neural, behavioral, and signaling mechanisms through which oxytocin’s anorexigenic effects occur. The research supports a framework through which oxytocin reduces food intake via amplification of within-meal physiological satiation signals rather than by altering between-meal interoceptive hunger and satiety states. We also emphasize the distributed neural sites of action for oxytocin’s effects on food intake and review evidence supporting the notion that central oxytocin is communicated throughout the brain, at least in part, through humoral-like volume transmission. Finally, we highlight mechanisms through which oxytocin interacts with various energy balance-associated neuropeptide and endocrine systems (e.g., agouti-related peptide, melanin-concentrating hormone, leptin), as well as the behavioral mechanisms through which oxytocin inhibits food intake, including effects on nutrient-specific ingestion, meal size control, food reward-motivated responses, and competing motivations.
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16
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Edwards MM, Nguyen HK, Dodson AD, Herbertson AJ, Wietecha TA, Wolden-Hanson T, Graham JL, Honeycutt MK, Slattery JD, O’Brien KD, Havel PJ, Blevins JE. Effects of Combined Oxytocin and Beta-3 Receptor Agonist (CL 316243) Treatment on Body Weight and Adiposity in Male Diet-Induced Obese Rats. Front Physiol 2021; 12:725912. [PMID: 34566687 PMCID: PMC8457402 DOI: 10.3389/fphys.2021.725912] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/05/2021] [Indexed: 11/13/2022] Open
Abstract
Previous studies have indicated that oxytocin (OT) reduces body weight in diet-induced obese (DIO) rodents through reductions in energy intake and increases in energy expenditure. We recently demonstrated that hindbrain [fourth ventricular (4V)] administration of OT evokes weight loss and elevates interscapular brown adipose tissue temperature (T IBAT ) in DIO rats. What remains unclear is whether OT can be used as an adjunct with other drugs that directly target beta-3 receptors in IBAT to promote BAT thermogenesis and reduce body weight in DIO rats. We hypothesized that the combined treatment of OT and the beta-3 agonist, CL 316243, would produce an additive effect to decrease body weight and adiposity in DIO rats by reducing energy intake and increasing BAT thermogenesis. We assessed the effects of 4V infusions of OT (16 nmol/day) or vehicle (VEH) in combination with daily intraperitoneal injections of CL 316243 (0.5 mg/kg) or VEH on food intake, T IBAT , body weight and body composition. OT and CL 316243 alone reduced body weight by 7.8 ± 1.3% (P < 0.05) and 9.1 ± 2.1% (P < 0.05), respectively, but the combined treatment produced more pronounced weight loss (15.5 ± 1.2%; P < 0.05) than either treatment alone. These effects were associated with decreased adiposity, adipocyte size, energy intake and increased uncoupling protein 1 (UCP-1) content in epididymal white adipose tissue (EWAT) (P < 0.05). In addition, CL 316243 alone (P < 0.05) and in combination with OT (P < 0.05) elevated T IBAT and IBAT UCP-1 content and IBAT thermogenic gene expression. These findings are consistent with the hypothesis that the combined treatment of OT and the beta-3 agonist, CL 316243, produces an additive effect to decrease body weight. The findings from the current study suggest that the effects of the combined treatment on energy intake, fat mass, adipocyte size and browning of EWAT were not additive and appear to be driven, in part, by transient changes in energy intake in response to OT or CL 316243 alone as well as CL 316243-elicited reduction of fat mass and adipocyte size and induction of browning of EWAT.
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Affiliation(s)
- Melise M. Edwards
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - Ha K. Nguyen
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - Andrew D. Dodson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - Adam J. Herbertson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - Tomasz A. Wietecha
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA, United States
| | - Tami Wolden-Hanson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - James L. Graham
- Department of Nutrition, University of California, Davis, Davis, CA, United States
| | - Mackenzie K. Honeycutt
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - Jared D. Slattery
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
| | - Kevin D. O’Brien
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA, United States
- Division of Cardiology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - Peter J. Havel
- Department of Nutrition, University of California, Davis, Davis, CA, United States
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - James E. Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA, United States
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
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Kerem L, Lawson EA. The Effects of Oxytocin on Appetite Regulation, Food Intake and Metabolism in Humans. Int J Mol Sci 2021; 22:7737. [PMID: 34299356 PMCID: PMC8306733 DOI: 10.3390/ijms22147737] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/13/2021] [Accepted: 07/16/2021] [Indexed: 12/18/2022] Open
Abstract
The hypothalamic peptide oxytocin and its receptor are involved in a range of physiological processes, including parturition, lactation, cell growth, wound healing, and social behavior. More recently, increasing evidence has established the effects of oxytocin on food intake, energy expenditure, and peripheral metabolism. In this review, we provide a comprehensive description of the central oxytocinergic system in which oxytocin acts to shape eating behavior and metabolism. Next, we discuss the peripheral beneficial effects oxytocin exerts on key metabolic organs, including suppression of visceral adipose tissue inflammation, skeletal muscle regeneration, and bone tissue mineralization. A brief summary of oxytocin actions learned from animal models is presented, showing that weight loss induced by chronic oxytocin treatment is related not only to its anorexigenic effects, but also to the resulting increase in energy expenditure and lipolysis. Following an in-depth discussion on the technical challenges related to endogenous oxytocin measurements in humans, we synthesize data related to the association between endogenous oxytocin levels, weight status, metabolic syndrome, and bone health. We then review clinical trials showing that in humans, acute oxytocin administration reduces food intake, attenuates fMRI activation of food motivation brain areas, and increases activation of self-control brain regions. Further strengthening the role of oxytocin in appetite regulation, we review conditions of hypothalamic insult and certain genetic pathologies associated with oxytocin depletion that present with hyperphagia, extreme weight gain, and poor metabolic profile. Intranasal oxytocin is currently being evaluated in human clinical trials to learn whether oxytocin-based therapeutics can be used to treat obesity and its associated sequela. At the end of this review, we address the fundamental challenges that remain in translating this line of research to clinical care.
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Affiliation(s)
- Liya Kerem
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA;
- Division of Pediatric Endocrinology, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | - Elizabeth A. Lawson
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA;
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18
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Edwards MM, Nguyen HK, Herbertson AJ, Dodson AD, Wietecha T, Wolden-Hanson T, Graham JL, O'Brien KD, Havel PJ, Blevins JE. Chronic hindbrain administration of oxytocin elicits weight loss in male diet-induced obese mice. Am J Physiol Regul Integr Comp Physiol 2021; 320:R471-R487. [PMID: 33470901 PMCID: PMC8238148 DOI: 10.1152/ajpregu.00294.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 02/08/2023]
Abstract
Previous studies indicate that oxytocin (OT) administration reduces body weight in high-fat diet (HFD)-induced obese (DIO) rodents through both reductions in food intake and increases in energy expenditure. We recently demonstrated that chronic hindbrain [fourth ventricular (4V)] infusions of OT evoke weight loss in DIO rats. Based on these findings, we hypothesized that chronic 4V OT would elicit weight loss in DIO mice. We assessed the effects of 4V infusions of OT (16 nmol/day) or vehicle over 28 days on body weight, food intake, and body composition. OT reduced body weight by approximately 4.5% ± 1.4% in DIO mice relative to OT pretreatment body weight (P < 0.05). These effects were associated with reduced adiposity and adipocyte size [inguinal white adipose tissue (IWAT)] (P < 0.05) and attributed, in part, to reduced energy intake (P < 0.05) at a dose that did not increase kaolin intake (P = NS). OT tended to increase uncoupling protein-1 expression in IWAT (0.05 < P < 0.1) suggesting that OT stimulates browning of WAT. To assess OT-elicited changes in brown adipose tissue (BAT) thermogenesis, we examined the effects of 4V OT on interscapular BAT temperature (TIBAT). 4V OT (1 µg) elevated TIBAT at 0.75 (P = 0.08), 1, and 1.25 h (P < 0.05) postinjection; a higher dose (5 µg) elevated TIBAT at 0.75-, 1-, 1.25-, 1.5-, 1.75- (P < 0.05), and 2-h (0.05 < P < 0.1) postinjection. Together, these findings support the hypothesis that chronic hindbrain OT treatment evokes sustained weight loss in DIO mice by reducing energy intake and increasing BAT thermogenesis at a dose that is not associated with evidence of visceral illness.
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MESH Headings
- Adipocytes, Brown/drug effects
- Adipocytes, Brown/metabolism
- Adipocytes, Brown/pathology
- Adipocytes, White/drug effects
- Adipocytes, White/metabolism
- Adipocytes, White/pathology
- Adiposity/drug effects
- Animals
- Anti-Obesity Agents/administration & dosage
- Diet, High-Fat
- Disease Models, Animal
- Eating/drug effects
- Energy Intake/drug effects
- Infusions, Intraventricular
- Leptin/blood
- Male
- Mice, Inbred C57BL
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- Obesity/physiopathology
- Oxytocin/administration & dosage
- Rhombencephalon/drug effects
- Rhombencephalon/physiopathology
- Thermogenesis/drug effects
- Uncoupling Protein 1/metabolism
- Weight Loss/drug effects
- Mice
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Affiliation(s)
- Melise M Edwards
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Ha K Nguyen
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Adam J Herbertson
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Andrew D Dodson
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Tomasz Wietecha
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
| | - Tami Wolden-Hanson
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - James L Graham
- Department of Nutrition, University of California, Davis, California
| | - Kevin D O'Brien
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
- Division of Cardiology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Peter J Havel
- Department of Nutrition, University of California, Davis, California
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - James E Blevins
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
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19
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Barrett LR, Nunez J, Zhang X. Oxytocin activation of paraventricular thalamic neurons promotes feeding motivation to attenuate stress-induced hypophagia. Neuropsychopharmacology 2021; 46:1045-1056. [PMID: 33495546 PMCID: PMC8114915 DOI: 10.1038/s41386-021-00961-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/29/2020] [Indexed: 01/30/2023]
Abstract
The neuropeptide oxytocin (OT) regulates important brain functions including feeding through activating OT receptors in multiple brain areas. Both OT fibers and OT receptors have been reported in the paraventricular thalamus (PVT), an area that was revealed to be important for the control of emotion, motivation, and food intake. However, the function and modulation of PVT OT signaling remain unknown. Here, we used a progressive ratio (PR) schedule of reinforcement to examine the role of PVT OT signaling in regulating the motivation for food and patch-clamp electrophysiology to study the modulation of OT on PVT neurons in brain slices. We demonstrate that PVT OT administration increases active lever presses to earn food rewards in both male and female mice under PR trials and OT receptor antagonist atosiban inhibits OT-induced increase in motivated lever presses. However, intra-PVT OT infusion does not affect food intake in normal conditions but attenuates hypophagia induced by stress and anxiety. Using patch-clamp recordings, we find OT induces long-lasting excitatory effects on neurons in all PVT regions, especially the middle to posterior PVT. OT not only evokes tonic inward currents but also increases the frequency of spontaneous excitatory postsynaptic currents on PVT neurons. The excitatory effect of OT on PVT neurons is mimicked by the specific OT receptor agonist [Thr4, Gly7]-oxytocin (TGOT) and blocked by OT receptor antagonist atosiban. Together, our study reveals a critical role of PVT OT signaling in promoting feeding motivation to attenuate stress-induced hypophagia through exciting PVT neurons.
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Affiliation(s)
- Lily R. Barrett
- grid.255986.50000 0004 0472 0419Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306 USA
| | - Jeremiah Nunez
- grid.255986.50000 0004 0472 0419Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306 USA
| | - Xiaobing Zhang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306, USA.
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20
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Abstract
The hypothalamic peptide oxytocin has been increasingly recognized as a hormone and neurotransmitter with important effects on energy intake, metabolism, and body weight and is under investigation as a potential novel therapeutic agent for obesity. The main neurons producing oxytocin and expressing the oxytocin receptor are strategically located in brain areas known to be critically involved in homeostatic energy balance as well as hedonic and motivational aspects of eating behavior. In this chapter, we will review the central and peripheral physiology of oxytocin and the interaction of oxytocin with key hormones and neural circuitries that affect food intake and metabolism. Next, we will synthesize the available data on endogenous oxytocin levels related to caloric intake, body weight, and metabolic status. We will then review the effects of exogenous oxytocin administration on eating behavior, body weight, and metabolism in humans, including in healthy individuals as well as specific populations with suspected perturbations involving oxytocin pathways. Finally, we will address the promise and fundamental challenges of translating this line of research to clinical care.
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Affiliation(s)
- Liya Kerem
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States; Division of Pediatric Endocrinology, Massachusetts General Hospital for Children, Boston, MA, United States
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.
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21
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Liu CM, Hsu TM, Suarez AN, Subramanian KS, Fatemi RA, Cortella AM, Noble EE, Roitman MF, Kanoski SE. Central oxytocin signaling inhibits food reward-motivated behaviors and VTA dopamine responses to food-predictive cues in male rats. Horm Behav 2020; 126:104855. [PMID: 32991888 PMCID: PMC7757852 DOI: 10.1016/j.yhbeh.2020.104855] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/02/2020] [Accepted: 08/23/2020] [Indexed: 01/08/2023]
Abstract
Oxytocin potently reduces food intake and is a potential target system for obesity treatment. A better understanding of the behavioral and neurobiological mechanisms mediating oxytocin's anorexigenic effects may guide more effective obesity pharmacotherapy development. The present study examined the effects of central (lateral intracerebroventricular [ICV]) administration of oxytocin in rats on motivated responding for palatable food. Various conditioning procedures were employed to measure distinct appetitive behavioral domains, including food seeking in the absence of consumption (conditioned place preference expression), impulsive responding for food (differential reinforcement of low rates of responding), effort-based appetitive decision making (high-effort palatable vs. low-effort bland food), and sucrose reward value encoding following a motivational shift (incentive learning). Results reveal that ICV oxytocin potently reduces food-seeking behavior, impulsivity, and effort-based palatable food choice, yet does not influence encoding of sucrose reward value in the incentive learning task. To investigate a potential neurobiological mechanism mediating these behavioral outcomes, we utilized in vivo fiber photometry in ventral tegmental area (VTA) dopamine neurons to examine oxytocin's effect on phasic dopamine neuron responses to sucrose-predictive Pavlovian cues. Results reveal that ICV oxytocin significantly reduced food cue-evoked dopamine neuron activity. Collectively, these data reveal that central oxytocin signaling inhibits various obesity-relevant conditioned appetitive behaviors, potentially via reductions in food cue-driven phasic dopamine neural responses in the VTA.
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Affiliation(s)
- Clarissa M Liu
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Ted M Hsu
- Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison St., Chicago, IL 60607-7137, United States
| | - Andrea N Suarez
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Keshav S Subramanian
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Ryan A Fatemi
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Alyssa M Cortella
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, 129 Barrow Hall, Athens, GA 30602, United States
| | - Mitchell F Roitman
- Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison St., Chicago, IL 60607-7137, United States
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States.
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22
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Wald HS, Chandra A, Kalluri A, Ong ZY, Hayes MR, Grill HJ. NTS and VTA oxytocin reduces food motivation and food seeking. Am J Physiol Regul Integr Comp Physiol 2020; 319:R673-R683. [PMID: 33026822 DOI: 10.1152/ajpregu.00201.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Oxytocin (OT) is a neuropeptide whose central receptor-mediated actions include reducing food intake. One mechanism of its behavioral action is the amplification of the feeding inhibitory effects of gastrointestinal (GI) satiation signals processed by hindbrain neurons. OT treatment also reduces carbohydrate intake in humans and rodents, and correspondingly, deficits in central OT receptor (OT-R) signaling increase sucrose self-administration. This suggests that additional processes contribute to central OT effects on feeding. This study investigated the hypothesis that central OT reduces food intake by decreasing food seeking and food motivation. As central OT-Rs are expressed widely, a related focus was to assess the role of one or more OT-R-expressing nuclei in food motivation and food-seeking behavior. OT was delivered to the lateral ventricle (LV), nucleus tractus solitarius (NTS), or ventral tegmental area (VTA), and a progressive ratio (PR) schedule of operant reinforcement and an operant reinstatement paradigm were used to measure motivated feeding behavior and food-seeking behavior, respectively. OT delivered to the LV, NTS, or VTA reduced 1) motivation to work for food and 2) reinstatement of food-seeking behavior. Results provide a novel and additional interpretation for central OT-driven food intake inhibition to include the reduction of food motivation and food seeking.
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Affiliation(s)
- Hallie S Wald
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ananya Chandra
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anita Kalluri
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zhi Yi Ong
- School of Psychology, University of New South Wales, Sydney, Australia
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Harvey J Grill
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
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23
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McCormack SE, Blevins JE, Lawson EA. Metabolic Effects of Oxytocin. Endocr Rev 2020; 41:5658523. [PMID: 31803919 PMCID: PMC7012298 DOI: 10.1210/endrev/bnz012] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022]
Abstract
There is growing evidence that oxytocin (OXT), a hypothalamic hormone well recognized for its effects in inducing parturition and lactation, has important metabolic effects in both sexes. The purpose of this review is to summarize the physiologic effects of OXT on metabolism and to explore its therapeutic potential for metabolic disorders. In model systems, OXT promotes weight loss by decreasing energy intake. Pair-feeding studies suggest that OXT-induced weight loss may also be partly due to increased energy expenditure and/or lipolysis. In humans, OXT appears to modulate both homeostatic and reward-driven food intake, although the observed response depends on nutrient milieu (eg, obese vs. nonobese), clinical characteristics (eg, sex), and experimental paradigm. In animal models, OXT is anabolic to muscle and bone, which is consistent with OXT-induced weight loss occurring primarily via fat loss. In some human observational studies, circulating OXT concentrations are also positively associated with lean mass and bone mineral density. The impact of exogenous OXT on human obesity is the focus of ongoing investigation. Future randomized, placebo-controlled clinical trials in humans should include rigorous, standardized, and detailed assessments of adherence, adverse effects, pharmacokinetics/pharmacodynamics, and efficacy in the diverse populations that may benefit from OXT, in particular those in whom hypothalamic OXT signaling may be abnormal or impaired (eg, individuals with Sim1 deficiency, Prader-Willi syndrome, or craniopharyngioma). Future studies will also have the opportunity to investigate the characteristics of new OXT mimetic peptides and the obligation to consider long-term effects, especially when OXT is given to children and adolescents. (Endocrine Reviews XX: XX - XX, 2020).
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Affiliation(s)
- Shana E McCormack
- Neuroendocrine Center, Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, Washington.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts.,Department of Medicine, Harvard Medical School, Boston, Massachusetts
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24
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Lawson EA, Olszewski PK, Weller A, Blevins JE. The role of oxytocin in regulation of appetitive behaviour, body weight and glucose homeostasis. J Neuroendocrinol 2020; 32:e12805. [PMID: 31657509 PMCID: PMC7186135 DOI: 10.1111/jne.12805] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/14/2019] [Accepted: 10/24/2019] [Indexed: 12/28/2022]
Abstract
Obesity and its associated complications have reached epidemic proportions in the USA and also worldwide, highlighting the need for new and more effective treatments. Although the neuropeptide oxytocin (OXT) is well recognised for its peripheral effects on reproductive behaviour, the release of OXT from somatodendrites and axonal terminals within the central nervous system (CNS) is also implicated in the control of energy balance. In this review, we summarise historical data highlighting the effects of exogenous OXT as a short-term regulator of food intake in a context-specific manner and the receptor populations that may mediate these effects. We also describe what is known about the physiological role of endogenous OXT in the control of energy balance and whether serum and brain levels of OXT relate to obesity on a consistent basis across animal models and humans with obesity. We describe recent data on the effectiveness of chronic CNS administration of OXT to decrease food intake and weight gain or to elicit weight loss in diet-induced obese (DIO) and genetically obese mice and rats. Of clinical importance is the finding that chronic central and peripheral OXT treatments both evoke weight loss in obese animal models with impaired leptin signalling at doses that are not associated with visceral illness, tachyphylaxis or adverse cardiovascular effects. Moreover, these results have been largely recapitulated following chronic s.c. or intranasal treatment in DIO non-human primates (rhesus monkeys) and obese humans, respectively. We also identify plausible mechanisms that contribute to the effects of OXT on body weight and glucose homeostasis in rodents, non-human primates and humans. We conclude by describing the ongoing challenges that remain before OXT-based therapeutics can be used as a long-term strategy to treat obesity in humans.
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Affiliation(s)
- Elizabeth A Lawson
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Pawel K Olszewski
- Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Aron Weller
- Psychology Department and Gonda Brain Research Center, Bar Ilan University, Ramat-Gan, Israel
| | - James E Blevins
- Department of Veterans Affairs Medical Center, Office of Research and Development Medical Research Service, VA Puget Sound Health Care System, Seattle, WA, USA
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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25
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Iwasa T, Matsuzaki T, Mayila Y, Kawakita T, Yanagihara R, Irahara M. The effects of chronic oxytocin administration on body weight and food intake in DHT-induced PCOS model rats. Gynecol Endocrinol 2020; 36:55-60. [PMID: 31220962 DOI: 10.1080/09513590.2019.1631276] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Polycystic ovary syndrome (PCOS) is commonly associated with metabolic disorders, which are exacerbated by obesity. Recent studies have revealed that oxytocin contributes to metabolic, appetite, and body weight regulation. In the present study, we evaluated the effects of chronic administration of oxytocin on body weight, food intake, and fat mass in a dihydrotestosterone-induced rat model of PCOS. Body weight, body weight change, and relative cumulative food intake were significantly lower in the oxytocin-treated PCOS rats than in the vehicle-treated control PCOS rats. Similarly, visceral adipocyte size was significantly smaller in the oxytocin-treated PCOS rats than in the vehicle-treated control PCOS rats. On the other hand, the numbers of cystic follicles in the ovary did not differ between the two groups. The chronic administration of oxytocin did not affect the rats' serum aspartate aminotransferase, alanine aminotransferase, or lactate dehydrogenase levels, indicating that it does not have adverse effects on hepatic function. These findings suggest that oxytocin could be a candidate drug for preventing the onset of obesity-related metabolic disorders in PCOS patients.
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Affiliation(s)
- Takeshi Iwasa
- Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Toshiya Matsuzaki
- Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Yiliyasi Mayila
- Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Takako Kawakita
- Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Rie Yanagihara
- Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Minoru Irahara
- Department of Obstetrics and Gynecology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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26
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English A, Irwin N. Nonclassical Islet Peptides: Pancreatic and Extrapancreatic Actions. CLINICAL MEDICINE INSIGHTS-ENDOCRINOLOGY AND DIABETES 2019; 12:1179551419888871. [PMID: 32425629 PMCID: PMC7216561 DOI: 10.1177/1179551419888871] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 02/06/2023]
Abstract
The pancreas has physiologically important endocrine and exocrine functions; secreting enzymes into the small intestine to aid digestion and releasing multiple peptide hormones via the islets of Langerhans to regulate glucose metabolism, respectively. Insulin and glucagon, in combination with ghrelin, pancreatic polypeptide and somatostatin, are the main classical islet peptides critical for the maintenance of blood glucose. However, pancreatic islets also synthesis numerous ‘nonclassical’ peptides that have recently been demonstrated to exert fundamental effects on overall islet function and metabolism. As such, insights into the physiological relevance of these nonclassical peptides have shown impact on glucose metabolism, insulin action, cell survival, weight loss, and energy expenditure. This review will focus on the role of individual nonclassical islet peptides to stimulate pancreatic islet secretions as well as regulate metabolism. In addition, the more recognised actions of these peptides on satiety and energy regulation will also be considered. Furthermore, recent advances in the field of peptide therapeutics and obesity-diabetes have focused on the benefits of simultaneously targeting several hormone receptor signalling cascades. The potential for nonclassical islet hormones within such combinational approaches will also be discussed.
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Affiliation(s)
- Andrew English
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Nigel Irwin
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, Northern Ireland, UK
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27
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Maejima Y, Kato S, Horita S, Ueta Y, Takenoshita S, Kobayashi K, Shimomura K. The hypothalamus to brainstem circuit suppresses late-onset body weight gain. Sci Rep 2019; 9:18360. [PMID: 31798010 PMCID: PMC6892811 DOI: 10.1038/s41598-019-54870-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 11/20/2019] [Indexed: 12/24/2022] Open
Abstract
Body weight (BW) is regulated in age-dependent manner; it continues to increase during growth period, and reaches a plateau once reaching adulthood. However, its underlying mechanism remains unknown. Regarding such mechanisms in the brain, we here report that neural circuits from the hypothalamus (paraventricular nucleus: PVN) to the brainstem (dorsal vagal complex: DVC) suppress late-onset BW gain without affecting food intake. The genetic suppression of the PVN-DVC circuit induced BW increase only in aged rats, indicating that this circuit contributes to suppress the BW at a fixed level after reaching adulthood. PVN neurons in the hypothalamus were inactive in younger rats but active in aged rats. The density of neuropeptide Y (NPY) terminal/fiber is reduced in the aged rat PVN area. The differences in neuronal activity, including oxytocin neurons in the PVN, were affected by the application of NPY or its receptor inhibitor, indicating that NPY is a possible regulator of this pathway. Our data provide new insights into understanding age-dependent BW regulation.
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Affiliation(s)
- Yuko Maejima
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Shigeki Kato
- Department of Molecular Genetics, Institute of Biomedical Science, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Shoichiro Horita
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, 807-8555, Japan
| | - Seiichi Takenoshita
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Science, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Kenju Shimomura
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan.
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28
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Liu CM, Davis EA, Suarez AN, Wood RI, Noble EE, Kanoski SE. Sex Differences and Estrous Influences on Oxytocin Control of Food Intake. Neuroscience 2019; 447:63-73. [PMID: 31738883 DOI: 10.1016/j.neuroscience.2019.10.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 10/25/2022]
Abstract
Central oxytocin potently reduces food intake and is being pursued as a clinical treatment for obesity. While sexually dimorphic effects have been described for the effects of oxytocin on several behavioral outcomes, the role of sex in central oxytocin modulation of feeding behavior is poorly understood. Here we investigated the effects of sex, estrous cycle stage, and female sex hormones (estrogen, progesterone) on central oxytocin-mediated reduction of food intake in rats. Results show that while intracerebroventricular (ICV) oxytocin potently reduces chow intake in both male and female rats, these effects were more pronounced in males than in females. We next examined whether estrous cycle stage affects oxytocin's food intake-reducing effects in females. Results show that ICV oxytocin administration significantly reduces food intake during all estrous cycle stages except proestrous, suggesting that female sex hormones may modulate the feeding effects of oxytocin. Indeed, additional results reveal that estrogen, but not progesterone replacement, in ovariectomized rats abolishes oxytocin-mediated reductions in chow intake. Lastly, oxytocin receptor mRNA (Oxtr) quantification (via quantitative PCR) and anatomical localization (via fluorescent in situ hybridization) in previously established sites of action for oxytocin control of food intake revealed comparable Oxtr expression between male and female rats, suggesting that observed sex and estrous differences may be based on variations in ligand availability and/or binding. Overall, these data show that estrogen reduces the effectiveness of central oxytocin to inhibit food intake, suggesting that sex hormones and estrous cycle should be considered in clinical investigations of oxytocin for obesity treatment.
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Affiliation(s)
- Clarissa M Liu
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Elizabeth A Davis
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Andrea N Suarez
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Ruth I Wood
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Integrative Anatomical Sciences, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Emily E Noble
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States; Department of Foods and Nutrition, University of Georgia, Athens, GA, United States.
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States.
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Relay of peripheral oxytocin to central oxytocin neurons via vagal afferents for regulating feeding. Biochem Biophys Res Commun 2019; 519:553-558. [PMID: 31537381 DOI: 10.1016/j.bbrc.2019.09.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 09/11/2019] [Indexed: 02/06/2023]
Abstract
Oxytocin (Oxt), a neurohormone synthesized in the neurons of hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus induces milk-ejection and uterine contraction and regulates social behavior, stress responses, memory and food intake. Peripheral (intraperitoneal and subcutaneous) infusion of Oxt decreases food intake and body weight in obese animals via mechanisms involving vagal afferent nerves and in obese subjects when administered nasally. Peripherally injected and intracerebroventricularly injected Oxt inhibit food intake to similar extent and with similar time course. Thus, peripheral Oxt mimics the effects of central Oxt, however, underlying mechanisms are unclear. In the present study we explored whether intraperitoneal Oxt activates Oxt neurons in PVN via vagal afferents and whether this pathway is linked to inhibition of feeding. We here show that intraperitoneal Oxt injection induces c-Fos expression in PVN largely in Oxt neurons and inhibits food intake, and these effects are blunted by subdiaphragmatic vagotomy. The intraperitoneal Oxt-induced inhibition of food intake was blunted in Oxt KO mice, by intracerebroventricular injection of Oxt receptor antagonist, and by vagotomy. These results demonstrate that intraperitoneal Oxt injection activates PVN Oxt neurons via vagal afferent nerves, thereby inhibiting food intake. This vagal afferents-mediated Oxt's peripheral-to-central coupling may serve to promote satiety and possibly a series of neural functions of Oxt and to treat their disorders.
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Snider B, Geiser A, Yu XP, Beebe EC, Willency JA, Qing K, Guo L, Lu J, Wang X, Yang Q, Efanov A, Adams AC, Coskun T, Emmerson PJ, Alsina-Fernandez J, Ai M. Long-Acting and Selective Oxytocin Peptide Analogs Show Antidiabetic and Antiobesity Effects in Male Mice. J Endocr Soc 2019; 3:1423-1444. [PMID: 31286109 PMCID: PMC6608564 DOI: 10.1210/js.2019-00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/10/2019] [Indexed: 12/29/2022] Open
Abstract
Oxytocin (OXT) has been shown to suppress appetite, induce weight loss, and improve glycemic control and lipid metabolism in several species, including humans, monkeys, and rodents. However, OXT's short half-life in circulation and lack of receptor selectivity limit its application and efficacy. In this study, we report an OXT peptide analog (OXTGly) that is potent and selective for the OXT receptor (OXTR). OXT, but not OXTGly, activated vasopressin receptors in vitro and acutely increased blood pressure in vivo when administered IP. OXT suppressed food intake in mice, whereas OXTGly had a moderate effect on food intake when administered IP or intracerebroventricularly. Both OXT (IP) and OXTGly (IP) improved glycemic control in glucose tolerance tests. Additionally, both OXT (IP) and OXTGly (IP) stimulated insulin, glucagon-like peptide 1, and glucagon secretion in mice. We generated lipid-conjugated OXT (acylated-OXT) and OXTGly (acylated-OXTGly) and demonstrated that these molecules have significantly extended half-lives in vivo. Compared with OXT, 2-week treatment of diet-induced obese mice with acylated-OXT [subcutaneous(ly) (SC)] resulted in enhanced body weight reduction, an improved lipid profile, and gene expression changes consistent with increased lipolysis and decreased gluconeogenesis. Treatment with acylated-OXTGly (SC) also resulted in a statistically significant weight loss, albeit to a lesser degree compared with acylated-OXT treatment. In conclusion, we demonstrate that selective activation of the OXTR pathway results in both acute and chronic metabolic benefits, whereas potential activation of vasopressin receptors by nonselective OXT analogs causes physiological stress that contributes to additional weight loss.
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Affiliation(s)
- Brandy Snider
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Andrea Geiser
- Biotechnology Peptide Group, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Xiao-peng Yu
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Emily Cathleen Beebe
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Jill Amanda Willency
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Keyun Qing
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Lili Guo
- Biotechnology Peptide Group, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Jianliang Lu
- Medicinal Chemistry, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Xiaojun Wang
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Qian Yang
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Alexander Efanov
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Andrew Charles Adams
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Tamer Coskun
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Paul Joseph Emmerson
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Jorge Alsina-Fernandez
- Biotechnology Peptide Group, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Minrong Ai
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
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Aulinas A, Pulumo RL, Asanza E, Mancuso CJ, Slattery M, Tolley C, Plessow F, Thomas JJ, Eddy KT, Miller KK, Klibanski A, Misra M, Lawson EA. Endogenous Oxytocin Levels in Relation to Food Intake, Menstrual Phase, and Age in Females. J Clin Endocrinol Metab 2019; 104:1348-1356. [PMID: 30445502 PMCID: PMC6408871 DOI: 10.1210/jc.2018-02036] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/13/2018] [Indexed: 12/22/2022]
Abstract
CONTEXT Oxytocin regulates a range of physiological processes including eating behavior and oxytocin administration reduces caloric intake in males. There are few data on oxytocin and eating behavior in healthy females or on the response of endogenous oxytocin to food intake and its relationship to appetite in humans. OBJECTIVES To determine the postprandial pattern of oxytocin levels, the relationship between oxytocin and appetite, and the impact of menstrual cycle phase and age on oxytocin levels in females. DESIGN Cross-sectional. SETTING Clinical research center. PARTICIPANTS Fifty-five healthy females (age 10 to 45 years). INTERVENTIONS A standardized mixed meal was administered. MAIN OUTCOME MEASUREMENTS Blood sampling for oxytocin occurred at fasting and at 30, 60, and 120 minutes postmeal. Appetite was assessed using Visual Analogue Scales pre- and postmeal. RESULTS Mean fasting oxytocin levels were 1011.2 ± 52.3 pg/mL (SEM) and decreased at 30 and 60 minutes postmeal (P = 0.001 and P = 0.003, respectively). Mean oxytocin levels decreased19.6% ± 3.0% from baseline to nadir. Oxytocin area under the curve was lower in the early to midfollicular menstrual cycle phase (P = 0.0003) and higher in younger females (P = 0.002). The percent change in oxytocin (baseline to nadir) was associated with postprandial hunger (rs = -0.291, P = 0.03) and fullness (rs = 0.345, P = 0.009). These relations remained significant after controlling for calories consumed, menstrual cycle status, and age (P = 0.023 and P = 0.0001, respectively). CONCLUSIONS Peripheral oxytocin levels in females decrease after a mixed meal and are associated with appetite independent of menstrual phase, age, and caloric intake, suggesting that endogenous oxytocin levels may play a role in perceived hunger and satiety.
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Affiliation(s)
- Anna Aulinas
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | | | - Elisa Asanza
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
| | | | - Meghan Slattery
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Christiane Tolley
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Franziska Plessow
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | - Jennifer J Thomas
- Harvard Medical School, Boston Massachusetts
- Eating Disorders Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston Massachusetts
| | - Kamryn T Eddy
- Harvard Medical School, Boston Massachusetts
- Eating Disorders Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston Massachusetts
| | - Karen K Miller
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | - Anne Klibanski
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | - Madhusmita Misra
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
- Pediatric Endocrine Unit, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
- Correspondence and Reprint Requests: Elizabeth A. Lawson, MD, MMSc, Neuroendocrine Unit, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114. E-mail:
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Skinner JA, Campbell EJ, Dayas CV, Garg ML, Burrows TL. The relationship between oxytocin, dietary intake and feeding: A systematic review and meta-analysis of studies in mice and rats. Front Neuroendocrinol 2019; 52:65-78. [PMID: 30315826 DOI: 10.1016/j.yfrne.2018.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/13/2018] [Accepted: 09/28/2018] [Indexed: 01/11/2023]
Abstract
The neuropeptide oxytocin has been associated with food intake and feeding behaviour. This systematic review aimed to investigate the impact of oxytocin on dietary intake and feeding behaviour in rodent studies. Six electronic databases were searched to identify published studies to April 2018. Preclinical studies in mice and rats were included if they reported: (1) a dietary measure (i.e. food or nutrient and/or behaviour (2) an oxytocin measure, and (3) relationship between the two measures. A total of 75 articles (n = 246 experiments) were included, and study quality appraised. The majority of studies were carried out in males (87%). The top three oxytocin outcomes assessed were: exogenous oxytocin administration (n = 126), oxytocin-receptor antagonist administration (n = 46) and oxytocin gene deletion (n = 29). Meta-analysis of exogenous studies in mice (3 studies, n = 43 comparisons) and rats (n = 8 studies, n = 82 comparisons) showed an overall decrease in food intake with maximum effect shown at 2 h post-administration.
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Affiliation(s)
- Janelle A Skinner
- Nutrition and Dietetics, School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia; Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Erin J Campbell
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, University of Melbourne, Victoria 3010, Australia.
| | - Christopher V Dayas
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Manohar L Garg
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Tracy L Burrows
- Nutrition and Dietetics, School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia; Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, NSW 2308, Australia.
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Wen S, Wang C, Gong M, Zhou L. An overview of energy and metabolic regulation. SCIENCE CHINA-LIFE SCIENCES 2018; 62:771-790. [PMID: 30367342 DOI: 10.1007/s11427-018-9371-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 08/23/2018] [Indexed: 12/21/2022]
Abstract
The physiology and behaviors related to energy balance are monitored by the nervous and humoral systems. Because of the difficulty in treating diabetes and obesity, elucidating the energy balance mechanism and identifying critical targets for treatment are important research goals. Therefore, the purpose of this article is to describe energy regulation by the central nervous system (CNS) and peripheral humoral pathway. Homeostasis and rewarding are the basis of CNS regulation. Anorexigenic or orexigenic effects reflect the activities of the POMC/CART or NPY/AgRP neurons within the hypothalamus. Neurotransmitters have roles in food intake, and responsive brain nuclei have different functions related to food intake, glucose monitoring, reward processing. Peripheral gut- or adipose-derived hormones are the major source of peripheral humoral regulation systems. Nutrients or metabolites and gut microbiota affect metabolism via a discrete pathway. We also review the role of peripheral organs, the liver, adipose tissue, and skeletal muscle in peripheral regulation. We discuss these topics and how the body regulates metabolism.
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Affiliation(s)
- Song Wen
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, China
| | - Chaoxun Wang
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, China
| | - Min Gong
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, China
| | - Ligang Zhou
- Department of Endocrinology, Shanghai Pudong Hospital, Fudan University, Shanghai, 201399, China.
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Seelke AM, Rhine MA, Khun K, Shweyk AN, Scott AM, Bond JM, Graham JL, Havel PJ, Wolden-Hanson T, Bales KL, Blevins JE. Intranasal oxytocin reduces weight gain in diet-induced obese prairie voles. Physiol Behav 2018; 196:67-77. [PMID: 30144467 DOI: 10.1016/j.physbeh.2018.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/17/2018] [Accepted: 08/19/2018] [Indexed: 12/17/2022]
Abstract
Oxytocin (OT) elicits weight loss in diet-induced obese (DIO) rodents, nonhuman primates and humans by reducing food intake and increasing energy expenditure. In addition to being important in the regulation of energy balance, OT is involved in social behaviors including parent-infant bonds, friendships, and pair bonds. However, the impact of social context on susceptibility to diet-induced obesity (DIO) and feeding behavior (including food sharing) has not been investigated in a rodent model that forms strong social bonds (i.e. prairie vole). Our goals were to determine in Prairie voles (Microtus ochrogaster) whether i) social context impacts susceptibility to DIO and ii) chronic intranasal OT reverses DIO. Voles were housed in divided cages with holes in the divider and paired with a same-sex animal with either the same food [high fat diet (HFD)/HFD, [low fat diet (LFD; chow)/chow], or the opposite food (HFD/chow or chow/HFD) for 19 weeks. HFD-fed voles pair-housed with voles maintained on the HFD demonstrated increased weight relative to pair-housed voles that were both maintained on chow. The study was repeated to determine the impact of social context on DIO susceptibility and body composition when animals are maintained on purified sugar-sweetened HFD and LFD to enhance palatability. As before, we found that voles demonstrated higher weight gain on the HFD/HFD housing paradigm, in part, through increased energy intake and the weight gain was a consequence of an increase in fat mass. However, HFD-fed animals housed with LFD-fed animals (and vice versa) showed intermediate patterns of weight gain and evidence of food sharing. Of translational importance is the finding that chronic intranasal OT appeared to reduce weight gain in DIO voles through a decrease in fat mass with no reduction in lean body mass. These effects were associated with transient reductions in food intake and increased food sharing. These findings identify a role of social context in the pathogenesis of DIO and indicate that chronic intranasal OT treatment reduces weight gain and body fat mass in DIO prairie voles, in part, by reducing food intake.
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Affiliation(s)
- Adele M Seelke
- Department of Psychology, University of California, Davis, CA, USA
| | - Maya A Rhine
- Department of Psychology, University of California, Davis, CA, USA
| | - Konterri Khun
- Department of Psychology, University of California, Davis, CA, USA
| | - Amira N Shweyk
- Department of Psychology, University of California, Davis, CA, USA
| | | | - Jessica M Bond
- Department of Psychology, University of California, Davis, CA, USA
| | - James L Graham
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Peter J Havel
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Tami Wolden-Hanson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA
| | - Karen L Bales
- Department of Psychology, University of California, Davis, CA, USA
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
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35
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Freeman SM, Ngo J, Singh B, Masnaghetti M, Bales KL, Blevins JE. Effects of Chronic Oxytocin Administration and Diet Composition on Oxytocin and Vasopressin 1a Receptor Binding in the Rat Brain. Neuroscience 2018; 392:241-251. [PMID: 30071278 DOI: 10.1016/j.neuroscience.2018.07.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/19/2022]
Abstract
Oxytocin (OT) elicits weight loss in diet-induced obese (DIO) rodents, nonhuman primates, and humans, in part, by reducing food intake. Chronic OT administration produces more sustained weight loss in high-fat diet (HFD)-fed DIO rodents relative to chow-fed controls, but the reasons for this effect remain unclear. We hypothesized that HFD-induced obesity is associated with elevated OT receptor (OXTR) binding in brain regions where OT is known to cause decreased food intake and that this sensitized neural system is one mechanism by which OT preferentially elicits weight loss in DIO rodents. We therefore determined the impact of diet (HFD vs chow) and drug treatment (chronic OT infusion vs vehicle) on (1) OXTR binding in hindbrain and forebrain sites where OT suppresses food intake relative to control sites that express OXTR and (2) forebrain vasopressin 1a receptor (AVPR1a) density to evaluate the specificity of any OT effects. Using quantitative receptor autoradiography, we found that (1) diet composition failed to alter OXTR or AVPR1a binding; (2) chronic OT treatment produced largely global reductions in forebrain OXTR and AVPR1a binding without significantly altering hindbrain OXTR binding. These findings suggest that forebrain OXTR and AVPR1a are down-regulated in response to chronic OT treatment. Given that chronic intranasal OT may be used as a therapeutic strategy to treat obesity, future studies should consider the potential downregulatory effect that chronic treatment can have across forebrain and hindbrain nonapeptide receptors and assess the potential contribution of both receptor subtypes to the outcome measures.
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Affiliation(s)
- Sara M Freeman
- Department of Psychology, University of California, Davis, CA, USA
| | - Julie Ngo
- Department of Psychology, University of California, Davis, CA, USA
| | - Bhavdeep Singh
- Department of Psychology, University of California, Davis, CA, USA
| | | | - Karen L Bales
- Department of Psychology, University of California, Davis, CA, USA
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
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36
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Leslie M, Silva P, Paloyelis Y, Blevins J, Treasure J. A Systematic Review and Quantitative Meta-Analysis of Oxytocin's Effects on Feeding. J Neuroendocrinol 2018; 30:10.1111/jne.12584. [PMID: 29480934 PMCID: PMC6292740 DOI: 10.1111/jne.12584] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/20/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE Oxytocin's anorexigenic effects have been widely documented and accepted; however, no paper has yet used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to compile previous findings in a single systematic review and quantitative meta-analysis. The current paper aimed to identify published and unpublished studies examining the effects of oxytocin on energy intake in animals and humans, and the factors that moderate this effect. METHODS Web of Science, Pub Med, and Ovid were searched for published and unpublished studies reporting the effects of oxytocin on energy intake in wild-type animals and in humans, when administered in the absence of other active drugs or surgery. RESULTS 2049 articles were identified through the original systematic literature search, from which 54 articles were identified as relevant for inclusion in this review. An additional 3 relevant articles were identified in a later update of the literature search. Overall, a single-dose of oxytocin was found to reduce feeding in animals. Despite several individual studies which found that this effect persists to the end of the third week of chronic administration in rodent models, overall, this anorexigenic effect did not hold in the meta-analyses testing the effects of chronic administration. There was no overall effect of oxytocin on energy intake in humans, although a trend was identified for oxytocin to reduce consumption of solid foods. CONCLUSIONS Oxytocin reduces energy intake when administered as a single dose. Oxytocin can inhibit feeding over two- to three-week periods in rodent models. These effects typically do not persist beyond the third week of treatment. The anorexigenic effect of oxytocin is moderated by pregnant status, dose, method of administration, and diet composition. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Monica Leslie
- Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London (KCL), London, UK
| | - Paulo Silva
- Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London (KCL), London, UK
| | - Yannis Paloyelis
- Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London (KCL), London, UK
| | - James Blevins
- Department of Veterans Affairs Medical Center, Office of Research and Development Medical Research Service, VA Puget Sound Health Care System, Seattle, WA, USA
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Janet Treasure
- Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London (KCL), London, UK
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Maejima Y, Yokota S, Nishimori K, Shimomura K. The Anorexigenic Neural Pathways of Oxytocin and Their Clinical Implication. Neuroendocrinology 2018; 107:91-104. [PMID: 29660735 DOI: 10.1159/000489263] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 04/15/2018] [Indexed: 12/21/2022]
Abstract
Oxytocin was discovered in 1906 as a peptide that promotes delivery and milk ejection; however, its additional physiological functions were determined 100 years later. Many recent articles have reported newly discovered effects of oxytocin on social communication, bonding, reward-related behavior, adipose tissue, and muscle and food intake regulation. Because oxytocin neurons project to various regions in the brain that contribute to both feeding reward (hedonic feeding) and the regulation of energy balance (homeostatic feeding), the mechanisms of oxytocin on food intake regulation are complicated and largely unknown. Oxytocin neurons in the paraventricular nucleus (PVN) receive neural projections from the arcuate nucleus (ARC), which is an important center for feeding regulation. On the other hand, these neurons in the PVN and supraoptic nucleus project to the ARC. PVN oxytocin neurons also project to the brain stem and the reward-related limbic system. In addition to this, oxytocin induces lipolysis and decreases fat mass. However, these effects in feeding and adipose tissue are known to be dependent on body weight (BW). Oxytocin treatment is more effective in food intake regulation and fat mass decline for individuals with leptin resistance and higher BW, but is known to be less effective in individuals with normal BW. In this review, we present in detail the recent findings on the physiological role of oxytocin in feeding regulation and the anorexigenic neural pathway of oxytocin neurons, as well as the advantage of oxytocin usage for anti-obesity treatment.
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Affiliation(s)
- Yuko Maejima
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Shoko Yokota
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Katsuhiko Nishimori
- Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kenju Shimomura
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, Japan
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38
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Ong ZY, Liu JJ, Pang ZP, Grill HJ. Paraventricular Thalamic Control of Food Intake and Reward: Role of Glucagon-Like Peptide-1 Receptor Signaling. Neuropsychopharmacology 2017; 42:2387-2397. [PMID: 28811669 PMCID: PMC5645740 DOI: 10.1038/npp.2017.150] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 01/18/2023]
Abstract
Paraventricular thalamic nucleus (PVT) neurons receive hindbrain and hypothalamic inputs, and project to forebrain sites involved in reward and motivation function. The role of PVT in energy balance and reward control is however understudied. Given that PVT neurons express glucagon-like peptide-1 receptors (GLP-1R), which are critical to feeding and body weight control, we tested the hypothesis that PVT GLP-1R signaling contributes to food intake and reward inhibition. To assess the hypothesis, behavioral tests including chow and high-fat diet intake, meal patterns, conditioned place preference for high-fat food, cue-induced reinstatement of sucrose-seeking, and motivation to work for sucrose were employed following intra-PVT delivery of either GLP-1R agonist, exendin-4 (Ex4), or GLP-1R antagonist, exendin-9-39 (Ex9). Anatomical and electrophysiological experiments were conducted to examine the neural connections and cellular mechanisms of GLP-1R signaling on PVT-to-nucleus accumbens (NAc) projecting neurons. PVT GLP-1R agonism reduced food intake, food-motivation, and food-seeking, while blocking endogenous PVT GLP-1R signaling increased meal size and food intake. PVT neurons receive GLP-1 innervation from nucleus tractus solitarius preproglucagon neurons that were activated by food intake; these GLP-1 fibers formed close appositions to putative GLP-1R-expressing PVT cells that project to the NAc. Electrophysiological recordings of PVT-to-NAc neurons revealed that GLP-1R activation reduced their excitability, mediated in part via suppression of excitatory synaptic drive. Collectively, these behavioral, electrophysiological and anatomical data illuminate a novel function for PVT GLP-1R signaling in food intake control and suggest a role for the PVT-to-NAc pathway in mediating the effects of PVT GLP-1R activation.
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Affiliation(s)
- Zhi Yi Ong
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA,School of Psychology, University of New South Wales, High Street, Sydney, NSW 2052, Australia, Tel: +612 9385 5480, Fax: +612 9385 3641, E-mail:
| | - Jing-Jing Liu
- Child Health Institute of New Jersey, Rutgers University Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Zhiping P Pang
- Child Health Institute of New Jersey, Rutgers University Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Harvey J Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
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Ong ZY, Bongiorno DM, Hernando MA, Grill HJ. Effects of Endogenous Oxytocin Receptor Signaling in Nucleus Tractus Solitarius on Satiation-Mediated Feeding and Thermogenic Control in Male Rats. Endocrinology 2017; 158:2826-2836. [PMID: 28575174 PMCID: PMC5659667 DOI: 10.1210/en.2017-00200] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/24/2017] [Indexed: 12/15/2022]
Abstract
Central oxytocin receptor (OT-R) signaling reduces food intake and increases energy expenditure, but the central sites and mechanisms mediating these effects are unresolved. We showed previously that pharmacological activation of OT-R in hindbrain/nucleus tractus solitarius (NTS) amplifies the intake-inhibitory effects of gastrointestinal (GI) satiation signals. Unexplored were the energetic effects of hindbrain OT-R agonism and the physiological relevance of NTS OT-R signaling on food intake and energy expenditure control. Using a virally mediated OT-R knockdown (KD) strategy and a range of behavioral paradigms, this study examined the role of endogenous NTS OT-R signaling on satiation-mediated food intake inhibition and thermogenic control. Results showed that, compared with controls, NTS OT-R KD rats consumed larger meals, were less responsive to the intake-inhibitory effects of a self-ingested preload, and consumed more chow following a 24-hour fast. These data indicate that NTS OT-R signaling is necessary for normal satiation control. Whereas both control and NTS OT-R KD rats increased core temperature following high-fat diet maintenance (relative to chow maintenance), the percent increase in core temperature was greater in control compared with NTS OT-R KD rats during the light cycle. Hindbrain oxytocin agonist delivery increased core temperature in both control and NTS OT-R KD rats and the percent increase relative to vehicle treatment was not significantly different between groups. Together, data reveal a critical role for endogenous NTS OT-R signaling in mediating the intake-inhibitory effects of endogenous GI satiation signals and in diet-induced thermogenesis.
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Affiliation(s)
- Zhi Yi Ong
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Diana M. Bongiorno
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Mary Ann Hernando
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Harvey J. Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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40
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Roberts ZS, Wolden-Hanson T, Matsen ME, Ryu V, Vaughan CH, Graham JL, Havel PJ, Chukri DW, Schwartz MW, Morton GJ, Blevins JE. Chronic hindbrain administration of oxytocin is sufficient to elicit weight loss in diet-induced obese rats. Am J Physiol Regul Integr Comp Physiol 2017; 313:R357-R371. [PMID: 28747407 DOI: 10.1152/ajpregu.00169.2017] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/30/2017] [Accepted: 07/02/2017] [Indexed: 02/06/2023]
Abstract
Oxytocin (OT) administration elicits weight loss in diet-induced obese (DIO) rodents, nonhuman primates, and humans by reducing energy intake and increasing energy expenditure. Although the neurocircuitry underlying these effects remains uncertain, OT neurons in the paraventricular nucleus are positioned to control both energy intake and sympathetic nervous system outflow to interscapular brown adipose tissue (BAT) through projections to the hindbrain nucleus of the solitary tract and spinal cord. The current work was undertaken to examine whether central OT increases BAT thermogenesis, whether this effect involves hindbrain OT receptors (OTRs), and whether such effects are associated with sustained weight loss following chronic administration. To assess OT-elicited changes in BAT thermogenesis, we measured the effects of intracerebroventricular administration of OT on interscapular BAT temperature in rats and mice. Because fourth ventricular (4V) infusion targets hindbrain OTRs, whereas third ventricular (3V) administration targets both forebrain and hindbrain OTRs, we compared responses to OT following chronic 3V infusion in DIO rats and mice and chronic 4V infusion in DIO rats. We report that chronic 4V infusion of OT into two distinct rat models recapitulates the effects of 3V OT to ameliorate DIO by reducing fat mass. While reduced food intake contributes to this effect, our finding that 4V OT also increases BAT thermogenesis suggests that increased energy expenditure may contribute as well. Collectively, these findings support the hypothesis that, in DIO rats, OT action in the hindbrain evokes sustained weight loss by reducing energy intake and increasing BAT thermogenesis.
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Affiliation(s)
- Zachary S Roberts
- Veterans Affairs Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, Washington
| | - Tami Wolden-Hanson
- Veterans Affairs Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, Washington
| | - Miles E Matsen
- University of Washington Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
| | - Vitaly Ryu
- Department of Biology, Georgia State University, Atlanta, Georgia; and.,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia
| | - Cheryl H Vaughan
- Department of Biology, Georgia State University, Atlanta, Georgia; and.,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia
| | - James L Graham
- Departments of Nutrition and Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - Peter J Havel
- Departments of Nutrition and Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - Daniel W Chukri
- Veterans Affairs Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, Washington
| | - Michael W Schwartz
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington.,University of Washington Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
| | - Gregory J Morton
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington.,University of Washington Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
| | - James E Blevins
- Veterans Affairs Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, Washington; .,Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
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41
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Leng G, Sabatier N. Oxytocin - The Sweet Hormone? Trends Endocrinol Metab 2017; 28:365-376. [PMID: 28283319 DOI: 10.1016/j.tem.2017.02.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/07/2017] [Accepted: 02/10/2017] [Indexed: 12/14/2022]
Abstract
Mammalian neurons that produce oxytocin and vasopressin apparently evolved from an ancient cell type with both sensory and neurosecretory properties that probably linked reproductive functions to energy status and feeding behavior. Oxytocin in modern mammals is an autocrine/paracrine regulator of cell function, a systemic hormone, a neuromodulator released from axon terminals within the brain, and a 'neurohormone' that acts at receptors distant from its site of release. In the periphery oxytocin is involved in electrolyte homeostasis, gastric motility, glucose homeostasis, adipogenesis, and osteogenesis, and within the brain it is involved in food reward, food choice, and satiety. Oxytocin preferentially suppresses intake of sweet-tasting carbohydrates while improving glucose tolerance and supporting bone remodeling, making it an enticing translational target.
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Affiliation(s)
- Gareth Leng
- Centre for Integrative Physiology, The University of Edinburgh, Edinburgh UK.
| | - Nancy Sabatier
- Centre for Integrative Physiology, The University of Edinburgh, Edinburgh UK
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Abstract
In this article we review the scientific contributions of Anthony Sclafani, with specific emphasis on his early work on the neural substrate of the ventromedial hypothalamic (VMH) hyperphagia-obesity syndrome, and on the development of diet-induced obesity (DIO). Over a period of 20 years Sclafani systematically investigated the neuroanatomical basis of the VMH hyperphagia-obesity syndrome, and ultimately identified a longitudinal oxytocin-containing neural tract contributing to its expression. This tract has since been implicated in mediating the effects of at least two gastrointestinal satiety factors. Sclafani was one of the first investigators to demonstrate DIO in rats as a result of exposure to multiple palatable food items (the "supermarket diet"), and concluded that diet palatability was the primary factor responsible for DIO. Sclafani went on to investigate the potency of specific carbohydrate and fat stimuli for inducing hyperphagia, and in so doing discovered that post-ingestive nutrient effects contribute to the elevated intake of palatable food items. To further investigate this effect, he devised an intragastric infusion system which allowed the introduction of nutrients into the gut paired with the oral intake of flavored solutions, an apparatus her termed the "electronic esophagus". Sclafani coined the term "appetition" to describe the effect of intestinal nutrient sensing on post-ingestive appetite stimulation. Sclafani's productivity in the research areas he chose to investigate has been nothing short of extraordinary, and his studies are characterized by inventive hypothesizing and meticulous experimental design. His results and conclusions, to our knowledge, have never been contradicted.
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Affiliation(s)
- Joseph R Vasselli
- New York Obesity-Nutrition Research Center, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Gerard P Smith
- Department of Psychiatry, Weill Cornell Medicine, Payne Whitney Westchester, New York-Presbyterian Hospital, 21 Bloomingdale Road, White Plains, NY, USA
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43
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Samson WK. Oxytocin redux. Am J Physiol Regul Integr Comp Physiol 2016; 311:R710-R713. [PMID: 27511282 DOI: 10.1152/ajpregu.00307.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/08/2016] [Accepted: 08/09/2016] [Indexed: 11/22/2022]
Affiliation(s)
- Willis K Samson
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, Missouri
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Motojima Y, Kawasaki M, Matsuura T, Saito R, Yoshimura M, Hashimoto H, Ueno H, Maruyama T, Suzuki H, Ohnishi H, Sakai A, Ueta Y. Effects of peripherally administered cholecystokinin-8 and secretin on feeding/drinking and oxytocin-mRFP1 fluorescence in transgenic rats. Neurosci Res 2016; 109:63-9. [PMID: 26919961 DOI: 10.1016/j.neures.2016.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 02/17/2016] [Accepted: 02/18/2016] [Indexed: 12/27/2022]
Abstract
Peripheral administration of cholecystokinin (CCK)-8 or secretin activates oxytocin (OXT)-secreting neurons in the hypothalamus. Although OXT is involved in the regulation of feeding behavior, detailed mechanism remains unclear. In the present study, we examined the central OXTergic pathways after intraperitoneally (i.p.) administration of CCK-8 and secretin using male OXT-monomeric red fluorescent protein 1 (mRFP1) transgenic rats and male Wistar rats. I.p. administration of CCK-8 (50μg/kg) and secretin (100μg/kg) decreased food intake in these rats. While i.p. administration of CCK-8 decreased water intake, i.p. administration of secretin increased water intake. Immunohistochemical study revealed that Fos-Like-Immunoreactive cells were observed abundantly in the brainstem and in the OXT neurons in the dorsal division of the parvocellular paraventricular nucleus (dpPVN). We could observe marked increase of mRFP1 fluorescence, as an indicator for OXT, in the dpPVN and mRFP1-positive granules in axon terminals of the dpPVN OXT neurons in the nucleus tractus solitarius (NTS) after i.p. administration of CCK-8 and secretin. These results provide us the evidence that, at least in part, i.p. administration of CCK-8 or secretin might be involved in the regulation of feeding/drinking via a OXTergic pathway from the dpPVN to the NTS.
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Affiliation(s)
- Yasuhito Motojima
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan; Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Makoto Kawasaki
- Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Takanori Matsuura
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan; Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Reiko Saito
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Mitsuhiro Yoshimura
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Hirofumi Hashimoto
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Hiromichi Ueno
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Takashi Maruyama
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Hitoshi Suzuki
- Department of Orthopaedics, Wakamatsu Hospital for University of Occupational and Environmental Health, Kitakyushu 808-0024, Japan
| | - Hideo Ohnishi
- Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Akinori Sakai
- Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
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Tabe-Bordbar S, Anastasio TJ. Computational Analysis of the Hypothalamic Control of Food Intake. Front Comput Neurosci 2016; 10:27. [PMID: 27199725 PMCID: PMC4844610 DOI: 10.3389/fncom.2016.00027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/14/2016] [Indexed: 12/01/2022] Open
Abstract
Food-intake control is mediated by a heterogeneous network of different neural subtypes, distributed over various hypothalamic nuclei and other brain structures, in which each subtype can release more than one neurotransmitter or neurohormone. The complexity of the interactions of these subtypes poses a challenge to understanding their specific contributions to food-intake control, and apparent consistencies in the dataset can be contradicted by new findings. For example, the growing consensus that arcuate nucleus neurons expressing Agouti-related peptide (AgRP neurons) promote feeding, while those expressing pro-opiomelanocortin (POMC neurons) suppress feeding, is contradicted by findings that low AgRP neuron activity and high POMC neuron activity can be associated with high levels of food intake. Similarly, the growing consensus that GABAergic neurons in the lateral hypothalamus suppress feeding is contradicted by findings suggesting the opposite. Yet the complexity of the food-intake control network admits many different network behaviors. It is possible that anomalous associations between the responses of certain neural subtypes and feeding are actually consistent with known interactions, but their effect on feeding depends on the responses of the other neural subtypes in the network. We explored this possibility through computational analysis. We made a computer model of the interactions between the hypothalamic and other neural subtypes known to be involved in food-intake control, and optimized its parameters so that model behavior matched observed behavior over an extensive test battery. We then used specialized computational techniques to search the entire model state space, where each state represents a different configuration of the responses of the units (model neural subtypes) in the network. We found that the anomalous associations between the responses of certain hypothalamic neural subtypes and feeding are actually consistent with the known structure of the food-intake control network, and we could specify the ways in which the anomalous configurations differed from the expected ones. By analyzing the temporal relationships between different states we identified the conditions under which the anomalous associations can occur, and these stand as model predictions.
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Affiliation(s)
- Shayan Tabe-Bordbar
- Computational Neurobiology Laboratory, Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign Urbana, IL, USA
| | - Thomas J Anastasio
- Computational Neurobiology Laboratory, Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign Urbana, IL, USA
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Deng QJ, Deng DJ, Che J, Zhao HR, Yu JJ, Lu YY. Hypothalamic paraventricular nucleus stimulation reduces intestinal injury in rats with ulcerative colitis. World J Gastroenterol 2016; 22:3769-3776. [PMID: 27076761 PMCID: PMC4814739 DOI: 10.3748/wjg.v22.i14.3769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 01/11/2016] [Accepted: 01/18/2016] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis (UC).
METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus (PVN), and the effect of the nucleus tractus solitarius (NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the PVN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin (IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the PVN in rats were detected by Western blot. Malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in colon tissues of rats were measured by colorimetric methods.
RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulation of the PVN on rats with UC were eliminated after chemical damage to the PVN. After glutamate receptor antagonist kynurenic acid was injected into the PVN, the protective effects of the chemical stimulation of the PVN were eliminated in rats with UC. After AVP-Vl receptor antagonist ([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of PVN on UC was also eliminated. After chemical stimulation of the PVN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC.
CONCLUSION: Chemical stimulation of the hypothalamic PVN provides a protective effect against UC injury in rats. Hypothalamic PVN, NTS and vagus nerve play key roles in this process.
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47
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Olszewski PK, Klockars A, Levine AS. Oxytocin: A Conditional Anorexigen whose Effects on Appetite Depend on the Physiological, Behavioural and Social Contexts. J Neuroendocrinol 2016; 28. [PMID: 26918919 DOI: 10.1111/jne.12376] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 02/16/2016] [Accepted: 02/19/2016] [Indexed: 01/17/2023]
Abstract
Central oxytocin suppresses appetite. Neuronal activity and the release of oxytocin coincide with satiation, as well as with adverse events (e.g. hyperosmolality, toxicity or excessive stomach distension) that necessitate an immediate termination of eating behaviour. Oxytocin also decreases consumption driven by reward, especially as derived from ingesting carbohydrates and sweet tastants. This review summarises current knowledge of the role of oxytocin in food intake regulation and highlights a growing body of evidence showing that oxytocin is a conditional anorexigen [i.e. its effects on appetite differ significantly with respect to certain (patho)physiological, behavioural and social contexts].
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Affiliation(s)
- P K Olszewski
- Department of Biological Sciences, University of Waikato, Hamilton, New Zealand
| | - A Klockars
- Department of Biological Sciences, University of Waikato, Hamilton, New Zealand
| | - A S Levine
- Department of Food Science and Nutrition, University of Minnesota, St Paul, MN, USA
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48
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Elson AE, Simerly RB. Developmental specification of metabolic circuitry. Front Neuroendocrinol 2015; 39:38-51. [PMID: 26407637 PMCID: PMC4681622 DOI: 10.1016/j.yfrne.2015.09.003] [Citation(s) in RCA: 15] [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] [Received: 09/14/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 01/16/2023]
Abstract
The hypothalamus contains a core circuitry that communicates with the brainstem and spinal cord to regulate energy balance. Because metabolic phenotype is influenced by environmental variables during perinatal development, it is important to understand how these neural pathways form in order to identify key signaling pathways that are responsible for metabolic programming. Recent progress in defining gene expression events that direct early patterning and cellular specification of the hypothalamus, as well as advances in our understanding of hormonal control of central neuroendocrine pathways, suggest several key regulatory nodes that may represent targets for metabolic programming of brain structure and function. This review focuses on components of central circuitry known to regulate various aspects of energy balance and summarizes what is known about their developmental neurobiology within the context of metabolic programming.
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Affiliation(s)
- Amanda E Elson
- The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA
| | - Richard B Simerly
- The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA.
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49
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Blevins JE, Baskin DG. Translational and therapeutic potential of oxytocin as an anti-obesity strategy: Insights from rodents, nonhuman primates and humans. Physiol Behav 2015; 152:438-49. [PMID: 26013577 DOI: 10.1016/j.physbeh.2015.05.023] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/19/2015] [Accepted: 05/21/2015] [Indexed: 12/15/2022]
Abstract
The fact that more than 78 million adults in the US are considered overweight or obese highlights the need to develop new, effective strategies to treat obesity and its associated complications, including type 2 diabetes, kidney disease and cardiovascular disease. While the neurohypophyseal peptide oxytocin (OT) is well recognized for its peripheral effects to stimulate uterine contraction during parturition and milk ejection during lactation, release of OT within the brain is implicated in prosocial behaviors and in the regulation of energy balance. Previous findings indicate that chronic administration of OT decreases food intake and weight gain or elicits weight loss in diet-induced obese (DIO) mice and rats. Furthermore, chronic systemic treatment with OT largely reproduces the effects of central administration to reduce weight gain in DIO and genetically obese rodents at doses that do not appear to result in tolerance. These findings have now been recently extended to more translational models of obesity showing that chronic subcutaneous or intranasal OT treatment is sufficient to elicit body weight loss in DIO nonhuman primates and pre-diabetic obese humans. This review assesses the potential use of OT as a therapeutic strategy for treatment of obesity in rodents, nonhuman primates, and humans, and identifies potential mechanisms that mediate this effect.
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Affiliation(s)
- James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
| | - Denis G Baskin
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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