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Reich N, Hölscher C. Acylated Ghrelin as a Multi-Targeted Therapy for Alzheimer's and Parkinson's Disease. Front Neurosci 2020; 14:614828. [PMID: 33381011 PMCID: PMC7767977 DOI: 10.3389/fnins.2020.614828] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/27/2020] [Indexed: 12/13/2022] Open
Abstract
Much thought has been given to the impact of Amyloid Beta, Tau and Alpha-Synuclein in the development of Alzheimer's disease (AD) and Parkinson's disease (PD), yet the clinical failures of the recent decades indicate that there are further pathological mechanisms at work. Indeed, besides amyloids, AD and PD are characterized by the culminative interplay of oxidative stress, mitochondrial dysfunction and hyperfission, defective autophagy and mitophagy, systemic inflammation, BBB and vascular damage, demyelination, cerebral insulin resistance, the loss of dopamine production in PD, impaired neurogenesis and, of course, widespread axonal, synaptic and neuronal degeneration that leads to cognitive and motor impediments. Interestingly, the acylated form of the hormone ghrelin has shown the potential to ameliorate the latter pathologic changes, although some studies indicate a few complications that need to be considered in the long-term administration of the hormone. As such, this review will illustrate the wide-ranging neuroprotective properties of acylated ghrelin and critically evaluate the hormone's therapeutic benefits for the treatment of AD and PD.
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Affiliation(s)
- Niklas Reich
- Biomedical & Life Sciences Division, Lancaster University, Lancaster, United Kingdom
| | - Christian Hölscher
- Neurology Department, A Second Hospital, Shanxi Medical University, Taiyuan, China.,Research and Experimental Center, Henan University of Chinese Medicine, Zhengzhou, China
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An amylin and calcitonin receptor agonist modulates alcohol behaviors by acting on reward-related areas in the brain. Prog Neurobiol 2020; 200:101969. [PMID: 33278524 DOI: 10.1016/j.pneurobio.2020.101969] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/16/2020] [Accepted: 11/29/2020] [Indexed: 02/07/2023]
Abstract
Alcohol causes stimulatory behavioral responses by activating reward-processing brain areas including the laterodorsal (LDTg) and ventral tegmental areas (VTA) and the nucleus accumbens (NAc). Systemic administration of the amylin and calcitonin receptor agonist salmon calcitonin (sCT) attenuates alcohol-mediated behaviors, but the brain sites involved in this process remain unknown. Firstly, to identify potential sCT sites of action in the brain, we used immunohistochemistry after systemic administration of fluorescent-labeled sCT. We then performed behavioral experiments to explore how infused sCT into the aforementioned reward-processing brain areas affects acute alcohol-induced behaviors in mice and chronic alcohol consumption in rats. We show that peripheral sCT crosses the blood brain barrier and is detected in all the brain areas studied herein. sCT infused into the LDTg attenuates alcohol-evoked dopamine release in the NAc shell in mice and reduces alcohol intake in rats. sCT into the VTA blocks alcohol-induced locomotor stimulation and dopamine release in the NAc shell in mice and decreases alcohol intake in rats. Lastly, sCT into the NAc shell prevents alcohol-induced locomotor activity in mice. Our data suggest that central sCT modulates the ability of alcohol to activate reward-processing brain regions.
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Cornejo MP, Mustafá ER, Barrile F, Cassano D, De Francesco PN, Raingo J, Perello M. THE INTRIGUING LIGAND-DEPENDENT AND LIGAND-INDEPENDENT ACTIONS OF THE GROWTH HORMONE SECRETAGOGUE RECEPTOR ON REWARD-RELATED BEHAVIORS. Neurosci Biobehav Rev 2020; 120:401-416. [PMID: 33157147 DOI: 10.1016/j.neubiorev.2020.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023]
Abstract
The growth hormone secretagogue receptor (GHSR) is a G-protein-coupled receptor (GPCR) highly expressed in the brain, and also in some peripheral tissues. GHSR activity is evoked by the stomach-derived peptide hormone ghrelin and abrogated by the intestine-derived liver-expressed antimicrobial peptide 2 (LEAP2). In vitro, GHSR displays ligand-independent actions, including a high constitutive activity and an allosteric modulation of other GPCRs. Beyond its neuroendocrine and metabolic effects, cumulative evidence shows that GHSR regulates the activity of the mesocorticolimbic pathway and modulates complex reward-related behaviors towards different stimuli. Here, we review current evidence indicating that ligand-dependent and ligand-independent actions of GHSR enhance reward-related behaviors towards appetitive stimuli and drugs of abuse. We discuss putative neuronal networks and molecular mechanisms that GHSR would engage to modulate such reward-related behaviors. Finally, we briefly discuss imaging studies showing that ghrelin would also regulate reward processing in humans. Overall, we conclude that GHSR is a key regulator of the mesocorticolimbic pathway that influences its activity and, consequently, modulates reward-related behaviors via ligand-dependent and ligand-independent actions.
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Affiliation(s)
- María P Cornejo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Emilio R Mustafá
- Laboratory of Electrophysiology of the IMBICE, 1900 La Plata, Buenos Aires, Argentina
| | - Franco Barrile
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Daniela Cassano
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Pablo N De Francesco
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Jesica Raingo
- Laboratory of Electrophysiology of the IMBICE, 1900 La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina.
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Fritz EM, Singewald N, De Bundel D. The Good, the Bad and the Unknown Aspects of Ghrelin in Stress Coping and Stress-Related Psychiatric Disorders. Front Synaptic Neurosci 2020; 12:594484. [PMID: 33192444 PMCID: PMC7652849 DOI: 10.3389/fnsyn.2020.594484] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 09/14/2020] [Indexed: 12/16/2022] Open
Abstract
Ghrelin is a peptide hormone released by specialized X/A cells in the stomach and activated by acylation. Following its secretion, it binds to ghrelin receptors in the periphery to regulate energy balance, but it also acts on the central nervous system where it induces a potent orexigenic effect. Several types of stressors have been shown to stimulate ghrelin release in rodents, including nutritional stressors like food deprivation, but also physical and psychological stressors such as foot shocks, social defeat, forced immobilization or chronic unpredictable mild stress. The mechanism through which these stressors drive ghrelin release from the stomach lining remains unknown and, to date, the resulting consequences of ghrelin release for stress coping remain poorly understood. Indeed, ghrelin has been proposed to act as a stress hormone that reduces fear, anxiety- and depression-like behaviors in rodents but some studies suggest that ghrelin may - in contrast - promote such behaviors. In this review, we aim to provide a comprehensive overview of the literature on the role of the ghrelin system in stress coping. We discuss whether ghrelin release is more than a byproduct of disrupted energy homeostasis following stress exposure. Furthermore, we explore the notion that ghrelin receptor signaling in the brain may have effects independent of circulating ghrelin and in what way this might influence stress coping in rodents. Finally, we examine how the ghrelin system could be utilized as a therapeutic avenue in stress-related psychiatric disorders (with a focus on anxiety- and trauma-related disorders), for example to develop novel biomarkers for a better diagnosis or new interventions to tackle relapse or treatment resistance in patients.
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Affiliation(s)
- Eva Maria Fritz
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, University of Innsbruck, Innsbruck, Austria
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, University of Innsbruck, Innsbruck, Austria
| | - Dimitri De Bundel
- Department of Pharmaceutical Sciences, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
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Cornejo MP, Barrile F, Cassano D, Aguggia JP, García Romero G, Reynaldo M, Andreoli MF, De Francesco PN, Perello M. Growth hormone secretagogue receptor in dopamine neurons controls appetitive and consummatory behaviors towards high-fat diet in ad-libitum fed mice. Psychoneuroendocrinology 2020; 119:104718. [PMID: 32535402 DOI: 10.1016/j.psyneuen.2020.104718] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 01/10/2023]
Abstract
Growth hormone secretagogue receptor (GHSR), the receptor for ghrelin, is expressed in key brain nuclei that regulate food intake. The dopamine (DA) pathways have long been recognized to play key roles mediating GHSR effects on feeding behaviors. Here, we aimed to determine the role of GHSR in DA neurons controlling appetitive and consummatory behaviors towards high fat (HF) diet. For this purpose, we crossed reactivable GHSR-deficient mice with DA transporter (DAT)-Cre mice, which express Cre recombinase under the DAT promoter that is active exclusively in DA neurons, to generate mice with GHSR expression limited to DA neurons (DAT-GHSR mice). We found that DAT-GHSR mice show an increase of c-Fos levels in brain areas containing DA neurons after ghrelin treatment, in a similar fashion as seen in wild-type mice; however, they did not increase food intake or locomotor activity in response to systemically- or centrally-administered ghrelin. In addition, we found that satiated DAT-GHSR mice displayed both anticipatory activity to scheduled HF diet exposure and HF intake in a binge-like eating protocol similar to those in wild-type mice, whereas GHSR-deficient mice displayed impaired responses. We conclude that GHSR expression in DA neurons is sufficient to both mediate increased anticipatory activity to a scheduled HF diet exposure and fully orchestrate binge-like HF intake, but it is insufficient to restore the acute orexigenic or locomotor effects of ghrelin treatment. Thus, GHSR in DA neurons affects appetitive and consummatory behaviors towards HF diet that take place in the absence of caloric needs.
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Affiliation(s)
- María Paula Cornejo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Franco Barrile
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Daniela Cassano
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Julieta Paola Aguggia
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Guadalupe García Romero
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Mirta Reynaldo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - María Florencia Andreoli
- Laboratory of Experimental Neurodevelopment, Institute of Development and Pediatric Research (IDIP), La Plata Children's Hospital and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina
| | - Pablo Nicolás De Francesco
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], 1900 La Plata, Buenos Aires, Argentina.
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Lis M, Stańczykiewicz B, Liśkiewicz P, Misiak B. Impaired hormonal regulation of appetite in schizophrenia: A narrative review dissecting intrinsic mechanisms and the effects of antipsychotics. Psychoneuroendocrinology 2020; 119:104744. [PMID: 32534330 DOI: 10.1016/j.psyneuen.2020.104744] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/25/2020] [Accepted: 05/30/2020] [Indexed: 12/14/2022]
Abstract
Cardiometabolic diseases are the main contributor of reduced life expectancy in patients with schizophrenia. It is now widely accepted that antipsychotic treatment plays an important role in the development of obesity and its consequences. However, some intrinsic mechanisms need to be taken into consideration. One of these mechanisms might be related to impaired hormonal regulation of appetite in this group of patients. In this narrative review, we aimed to dissect impairments of appetite-regulating hormones attributable to intrinsic mechanisms and those related to medication effects. Early hormonal alterations that might be associated with intrinsic mechanisms include low levels of leptin and glucagon-like peptide-1 (GLP-1) together with elevated insulin levels in first-episode psychosis (FEP) patients. However, evidence regarding low GLP-1 levels in FEP patients is based on one large study. In turn, multiple-episode schizophrenia patients show elevated levels of insulin, leptin and orexin A together with decreased levels of adiponectin. In addition, patients receiving olanzapine may present with low ghrelin levels. Post mortem studies have also demonstrated reduced number of neuropeptide Y neurons in the prefrontal cortex of patients with schizophrenia. Treatment with certain second-generation antipsychotics may also point to these alterations. Although our understanding of hormonal regulation of appetite in schizophrenia has largely been improved, several limitations and directions for future studies need to be addressed. This is of particular importance since several novel pharmacological interventions for obesity and diabetes have already been developed and translation of these developments to the treatment of cardiometabolic comorbidities in schizophrenia patients is needed.
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Affiliation(s)
- Michał Lis
- Clinical Department of Internal Diseases, Endocrinology and Diabetology, The Central Clinical Hospital of the Ministry of the Interior in Warsaw, Wołoska 137 Street, 02-507 Warsaw, Poland
| | - Bartłomiej Stańczykiewicz
- Department of Nervous System Diseases, Wroclaw Medical University, Bartla 5 Street, 51-618, Wroclaw, Poland
| | - Paweł Liśkiewicz
- Department of Psychiatry, Pomeranian Medical University, Broniewskiego 26 Street, 71-460, Szczecin, Poland
| | - Błażej Misiak
- Department of Genetics, Wroclaw Medical University, Marcinkowskiego 1 Street, 50-368 Wroclaw, Poland.
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Beheshti S, Sami M, Mirzabeh A, Yazdi A. D-Lys-3-GHRP-6 impairs memory consolidation and downregulates the hippocampal serotonin HT1A, HT7 receptors and glutamate GluA1 subunit of AMPA receptors. Physiol Behav 2020; 223:112969. [DOI: 10.1016/j.physbeh.2020.112969] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 04/27/2020] [Accepted: 05/12/2020] [Indexed: 01/08/2023]
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Unexpected Association of Desacyl-Ghrelin with Physical Activity and Chronic Food Restriction: A Translational Study on Anorexia Nervosa. J Clin Med 2020; 9:jcm9092782. [PMID: 32872151 PMCID: PMC7565884 DOI: 10.3390/jcm9092782] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/19/2020] [Accepted: 08/22/2020] [Indexed: 01/20/2023] Open
Abstract
Anorexia nervosa (AN) is a severe metabopsychiatric disorder characterised by caloric intake restriction and often excessive physical exercise. Our aim is to assess in female AN patients and in a rodent model, the co-evolution of physical activity and potential dysregulation of acyl—(AG) and desacyl—(DAG) ghrelin plasma concentrations during denutrition and weight recovery. AN inpatients were evaluated at inclusion (T0, n = 29), half—(T1) and total (T2) weight recovery, and one month after discharge (T3, n = 13). C57/Bl6 mice with access to a running wheel, were fed ad libitum or submitted to short—(15 days) or long—(50 days) term quantitative food restriction, followed by refeeding (20 days). In AN patients, AG and DAG rapidly decreased during weight recovery (T0 to T2), AG increased significantly one-month post discharge (T3), but only DAG plasma concentrations at T3 correlated negatively with BMI and positively with physical activity. In mice, AG and DAG both increased during short- and long-term food restriction. After 20 days of ad libitum feeding, DAG was associated to persistence of exercise alteration. The positive association of DAG with physical activity during caloric restriction and after weight recovery questions its role in the adaptation mechanisms to energy deprivation that need to be considered in recovery process in AN.
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Bernardoni F, Bernhardt N, Pooseh S, King JA, Geisler D, Ritschel F, Boehm I, Seidel M, Roessner V, Smolka MN, Ehrlich S. Metabolic state and value-based decision-making in acute and recovered female patients with anorexia nervosa. J Psychiatry Neurosci 2020; 45:253-261. [PMID: 32129584 PMCID: PMC7828930 DOI: 10.1503/jpn.190031] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Patients with anorexia nervosa forgo eating despite emaciation and severe health consequences. Such dysfunctional decision-making might be explained by an excessive level of self-control, alterations in homeostatic and hedonic regulation, or an interplay between these processes. We aimed to understand value-based decision-making in anorexia nervosa and its association with the gut hormone ghrelin. Besides its homeostatic function, ghrelin has been implicated in the hedonic regulation of appetite and reward via the modulation of phasic dopamine signalling. METHODS In a cross-sectional design, we studied acutely underweight (n = 94) and recovered (n = 37) patients with anorexia nervosa of the restrictive subtype, as well as healthy control participants (n = 119). We assessed plasma concentrations of desacyl ghrelin and parameters of delay discounting, probability discounting for gains and losses, and loss aversion. RESULTS Recovered patients displayed higher risk aversion for gains, but we observed no group differences for the remaining decision-making parameters. Desacyl ghrelin was higher in acutely underweight and recovered participants with anorexia nervosa relative to healthy controls. Moreover, we found a significant group × desacyl ghrelin interaction in delay discounting, indicating that in contrast to healthy controls, acutely underweight patients with anorexia nervosa who had high desacyl ghrelin concentrations preferably chose the delayed reward option. LIMITATIONS We probed decision-making using monetary rewards, but patients with anorexia nervosa may react differently to disorder-relevant stimuli. Furthermore, in contrast to acyl ghrelin, the functions of desacyl ghrelin are unclear. Therefore, the interpretation of the results is preliminary. CONCLUSION The propensity for risk aversion as found in recovered patients with anorexia nervosa could help them successfully complete therapy, or it could reflect sequelae of the disorder. Conversely, ghrelin findings might be related to a mechanism contributing to disease maintenance; that is, in acutely underweight anorexia nervosa, a hungry state may facilitate the ability to forgo an immediate reward to achieve a (dysfunctional) long-term goal.
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Affiliation(s)
- Fabio Bernardoni
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Nadine Bernhardt
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Shakoor Pooseh
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Joseph A. King
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Daniel Geisler
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Franziska Ritschel
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Ilka Boehm
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Maria Seidel
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Veit Roessner
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Michael N. Smolka
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
| | - Stefan Ehrlich
- From the Division of Psychological and Social Medicine and Developmental Neuroscience, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Bernardoni, King, Geisler, Ritschel, Boehm, Seidel, Ehrlich); the Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany (Bernhardt, Pooseh, Smolka); the Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Germany (Pooseh); and the Translational Developmental Neuroscience Section, Eating Disorder Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany (Roessner, Ehrlich)
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Moose JE, Leets KA, Mate NA, Chisholm JD, Hougland JL. An overview of ghrelin O-acyltransferase inhibitors: a literature and patent review for 2010-2019. Expert Opin Ther Pat 2020; 30:581-593. [PMID: 32564644 DOI: 10.1080/13543776.2020.1776263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Affiliation(s)
- Jacob E Moose
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Katelyn A Leets
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Nilamber A Mate
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - John D Chisholm
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - James L Hougland
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
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Blanco-Gandía MC, Miñarro J, Rodríguez-Arias M. Common Neural Mechanisms of Palatable Food Intake and Drug Abuse: Knowledge Obtained with Animal Models. Curr Pharm Des 2020; 26:2372-2384. [DOI: 10.2174/1381612826666200213123608] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/23/2020] [Indexed: 02/07/2023]
Abstract
Eating is necessary for survival, but it is also one of the great pleasures enjoyed by human beings.
Research to date shows that palatable food can be rewarding in a similar way to drugs of abuse, indicating
considerable comorbidity between eating disorders and substance-use disorders. Analysis of the common characteristics
of both types of disorder has led to a new wave of studies proposing a Gateway Theory of food as a vulnerability
factor that modulates the development of drug addiction. The homeostatic and hedonic mechanisms of
feeding overlap with some of the mechanisms implicated in drug abuse and their interaction plays a crucial role in
the development of drug addiction. Studies in animal models have shown how palatable food sensitizes the reward
circuit and makes individuals more sensitive to other substances of abuse, such as cocaine or alcohol. However,
when palatable food is administered continuously as a model of obesity, the consequences are different, and
studies provide controversial data. In the present review, we will cover the main homeostatic and hedonic mechanisms
that regulate palatable food intake behavior and will explain, using animal models, how different types of
diet and their intake patterns have direct consequences on the rewarding effects of psychostimulants and ethanol.
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Affiliation(s)
- Maria C. Blanco-Gandía
- Department of Psychology and Sociology, University of Zaragoza, C/ Ciudad Escolar s/n, 44003, Teruel, Spain
| | - José Miñarro
- Unit of Research Psychobiology of Drug Dependence, Department of Psychobiology, Facultad de Psicologia, Universitat de Valencia, Avda. Blasco Ibanez, 21, 46010 Valencia, Spain
| | - Marta Rodríguez-Arias
- Unit of Research Psychobiology of Drug Dependence, Department of Psychobiology, Facultad de Psicologia, Universitat de Valencia, Avda. Blasco Ibanez, 21, 46010 Valencia, Spain
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Suarez AN, Liu CM, Cortella AM, Noble EE, Kanoski SE. Ghrelin and Orexin Interact to Increase Meal Size Through a Descending Hippocampus to Hindbrain Signaling Pathway. Biol Psychiatry 2020; 87:1001-1011. [PMID: 31836175 PMCID: PMC7188579 DOI: 10.1016/j.biopsych.2019.10.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/01/2019] [Accepted: 10/19/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Memory and cognitive processes influence the amount of food consumed during a meal, yet the neurobiological mechanisms mediating these effects are poorly understood. The hippocampus (HPC) has recently emerged as a brain region that integrates feeding-relevant biological signals with learning and memory processes to regulate feeding. We investigated whether the gut-derived hormone ghrelin acts in the ventral HPC (vHPC) to increase meal size through interactions with gut-derived satiation signaling. METHODS Interactions between vHPC ghrelin signaling, gut-derived satiation signaling, feeding, and interoceptive discrimination learning were assessed via rodent behavioral neuropharmacological approaches. Downstream neural pathways were identified using transsynaptic virus-based tracing strategies. RESULTS vHPC ghrelin signaling counteracted the food intake-reducing effects produced by various peripheral biological satiation signals, including cholecystokinin, exendin-4 (a glucagon-like peptide-1 receptor agonist), amylin, and mechanical distension of the stomach. Furthermore, vHPC ghrelin signaling produced interoceptive cues that generalized to a perceived state of energy deficit, thereby providing a potential mechanism for the attenuation of satiation processing. Neuroanatomical tracing identified a multiorder connection from vHPC neurons to lateral hypothalamic area orexin (hypocretin)-producing neurons that project to the laterodorsal tegmental nucleus in the hindbrain. Lastly, vHPC ghrelin signaling increased spontaneous meal size via downstream orexin receptor signaling in the laterodorsal tegmental nucleus. CONCLUSIONS vHPC ghrelin signaling increases meal size by counteracting the efficacy of various gut-derived satiation signals. These effects occur via downstream orexin signaling to the hindbrain laterodorsal tegmental nucleus, thereby highlighting a novel hippocampus-hypothalamus-hindbrain pathway regulating meal size control.
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Affiliation(s)
- Andrea N. Suarez
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA.,Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Clarissa M. Liu
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Alyssa M. Cortella
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Emily E. Noble
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Scott E. Kanoski
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA.,Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA,Correspondence: Dr. Scott E. Kanoski, Department of Biological Sciences, University of Southern California, 3560 Watt Way, PED 107, Los Angeles, CA 90089-0652, USA, Tel: +1 213 821 5762, Fax: +1 213 740 6159.
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Song B, Yan X, Li R, Zhang H. Ghrelin ameliorates chronic obstructive pulmonary disease-associated infllammation and autophagy. Biotechnol Appl Biochem 2020; 68:356-365. [PMID: 32357262 DOI: 10.1002/bab.1933] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/23/2020] [Indexed: 12/22/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a chronic and devastating condition characterized by poor airflow and breath. Smoking and other environmental factors-caused inflammations triggered excessive autophagy of normal lung epithelial cells, eventually leading to impaired lung functions. Previous studies showed that ghrelin exhibited beneficial effects on patients with COPD. However, the mechanisms underlying this impact remained largely unknown. In this study, in vitro and in vivo models of COPD-associated inflammation were established, and we found that inflammation and autophagy were abonormally activated through nuclear factor kappa b (NF-κB) and activator protein-1 (AP-1) signaling pathways. Interestingly, ghrelin could inhibit the excessive inflammation pathways and autophagy induced by particle matter and/or cigarette extract in bronchial epithelial cells. Furthermore, NF-κB and AP-1 signaling were both inhibited while lung functions were significantly improved. Taken together, identification of downstream signaling of ghrelin in inflammation provided a new avenue in the treatment of COPD.
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Affiliation(s)
- Beibei Song
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xixin Yan
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Rongqin Li
- Department of Central Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Huiran Zhang
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, China
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Yadegary A, Nazari-Serenjeh F, Darbandi N. Synergistic improvement effect of nicotine-ghrelin co-injection into the anterior ventral tegmental area on morphine-induced amnesia. Neuropeptides 2020; 80:102025. [PMID: 32029269 DOI: 10.1016/j.npep.2020.102025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 01/15/2020] [Accepted: 01/29/2020] [Indexed: 11/15/2022]
Abstract
In the present study the effect of ghrelin or ghrelin/nicotine injection into the anterior ventral tegmental area (aVTA) on morphine-induced amnesia in passive avoidance learning have been evaluated. Also, the role of the aVTA nicotinic receptors in possible ghrelin-induced effects has been investigated. All animals were bilaterally implanted with chronic cannulas in the aVTA. A step-through type passive avoidance task was used for measurement of memory. We found that post-training subcutaneous (s.c.) injection of morphine (0.5-7.5 mg/kg) dose-dependently reduced the step-through latency, indicating morphine-induced amnesia. Post-training bilateral infusion of ghrelin (0.3, 1.5 and 3 nmol/μl) in a dose-dependent manner reversed amnesia induced by morphine (7.5 mg/kg, s.c.). Furthermore, reversal effect of ghrelin (3 nmol/μl) was blocked by pre-treatment of intra-aVTA administration of mecamylamine (1-3 μg/rat), a nicotinic acetylcholine receptor antagonist. Intra-aVTA administration of the higher dose of mecamylamine (3 μg/rat) into the aVTA by itself decreased the step-through latency and induced amnesia. In addition, post-training intra-aVTA administration of nicotine (0.25, 0.5, 1 μg/rat) which alone cannot affect memory consolidation, decreased significantly the amnesia induced by morphine (7.5 mg/kg, s.c.). Co-treatment of an ineffective dose of ghrelin (0.3 nmol/μl) with an ineffective dose of nicotine (0.25 μg/rat) significantly increased step-through latency of morphine (7.5 mg/kg, s.c.) treated animals, indicating the synergistic effect of the drugs. Taken together, our results suggest that intra-aVTA administration of ghrelin reversed morphine-induced amnesia and that ghrelin interacts synergistically with nicotine to mitigate morphine-induced amnesia.
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Affiliation(s)
- Atena Yadegary
- Department of Biology, Faculty of Science, Arak University, Arak, Iran
| | | | - Niloufar Darbandi
- Department of Biology, Faculty of Science, Arak University, Arak, Iran
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Pierre A, Van Schuerbeek A, Allaoui W, Van Laere S, Singewald N, Van Eeckhaut A, Smolders I, De Bundel D. Effects of ghrelin receptor activation on forebrain dopamine release, conditioned fear and fear extinction in C57BL/6J mice. J Neurochem 2020; 154:389-403. [DOI: 10.1111/jnc.14996] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Anouk Pierre
- Department of Pharmaceutical Sciences Research Group Experimental Pharmacology Center for Neurosciences (C4N) Vrije Universiteit Brussel Brussels Belgium
| | - Andries Van Schuerbeek
- Department of Pharmaceutical Sciences Research Group Experimental Pharmacology Center for Neurosciences (C4N) Vrije Universiteit Brussel Brussels Belgium
| | - Wissal Allaoui
- Department of Pharmaceutical Sciences Research Group Experimental Pharmacology Center for Neurosciences (C4N) Vrije Universiteit Brussel Brussels Belgium
| | - Sven Van Laere
- Interfaculty Center Data Processing & Statistics Vrije Universiteit Brussel Brussels Belgium
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology Institute of Pharmacy and CMBI University of Innsbruck Innsbruck Austria
| | - Ann Van Eeckhaut
- Department of Pharmaceutical Sciences Research Group Experimental Pharmacology Center for Neurosciences (C4N) Vrije Universiteit Brussel Brussels Belgium
| | - Ilse Smolders
- Department of Pharmaceutical Sciences Research Group Experimental Pharmacology Center for Neurosciences (C4N) Vrije Universiteit Brussel Brussels Belgium
| | - Dimitri De Bundel
- Department of Pharmaceutical Sciences Research Group Experimental Pharmacology Center for Neurosciences (C4N) Vrije Universiteit Brussel Brussels Belgium
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Gorrell S, Collins AG, Le Grange D, Yang TT. Dopaminergic activity and exercise behavior in anorexia nervosa. OBM NEUROBIOLOGY 2020; 4:10.21926/obm.neurobiol.2001053. [PMID: 33569542 PMCID: PMC7872149 DOI: 10.21926/obm.neurobiol.2001053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Driven exercise (i.e., the tendency to exercise in excess to influence weight/shape or regulate emotion) is difficult to manage in the context of anorexia nervosa, and is associated with poorer treatment outcomes, and psychological and medical severity. Driven exercise is observed in a considerable number of those diagnosed with anorexia nervosa; however, to date, this hallmark symptom remains poorly understood. Dopamine signaling is implicated in motivating and maintaining appetitive behavior among patients with eating disorders; but, much less is known about the role of dopamine signaling specific to the symptom of driven exercise. An improved understanding of this biobehavioral mechanism may inform the etiology of driven exercise in anorexia nervosa, with the potential to impact future research and treatment efforts. This review describes the role that dopamine serves in maintaining symptoms in the context of anorexia nervosa, and synthesizes current relevant evidence on exercise in AN and related dopaminergic activity. Throughout, theoretical implications are discussed, along with critical directions for future research.
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Affiliation(s)
- Sasha Gorrell
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Anne G.E. Collins
- Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Daniel Le Grange
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Psychiatry & Behavioral Neuroscience, The University of Chicago, Chicago, IL, USA (Emeritus)
| | - Tony T. Yang
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
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Schmidt C, Perbandt M, Klussmann S, Betzel C. Molecular characterization of a ghrelin-l-aptamer complex. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Russel SM, Valle V, Spagni G, Hamilton S, Patel T, Abdukadyrov N, Dong Y, Gangemi A. Physiologic Mechanisms of Type II Diabetes Mellitus Remission Following Bariatric Surgery: a Meta-analysis and Clinical Implications. J Gastrointest Surg 2020; 24:728-741. [PMID: 31898109 DOI: 10.1007/s11605-019-04508-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 12/16/2019] [Indexed: 01/31/2023]
Abstract
INTRODUCTION As obesity prevalence grows in the USA, metabolic syndrome is becoming increasingly more common. Current theories propose that insulin resistance is responsible for the hypertension, dyslipidemia, type II diabetes mellitus (T2DM), and low HDL that comprise metabolic syndrome. Bariatric surgery is one potential treatment, and its effects include permanently altering the patient's physiology and glucose regulation. Consequently, patients with T2DM who undergo bariatric surgery often experience tighter glucose control or remission of their T2DM altogether. This meta-analysis aims to explore the physiologic mechanisms underlying T2DM remission following bariatric surgery, which demonstrates effects that could lead to expansion of the NIH criteria for bariatric surgery candidates. METHODS A comprehensive search was conducted in PubMed and Scopus. Two independent reviewers conducted title, abstract, and full text review of papers that met inclusion criteria. Papers that measured hormone levels before and after bariatric surgery were included in the meta-analysis. Weighted means and standard deviations were calculated for preoperative and postoperative GLP-1, GIP, ghrelin, and glucagon. RESULTS Total postprandial GLP-1 increased following bariatric surgery, which correlated with improvements in measures of glycemic control. Fasting GLP-1, fasting GIP, total postprandial GIP, total fasting ghrelin, and fasting glucagon all decreased, but all changes in hormones evaluated failed to reach statistical significance. Studies also demonstrated changes in hepatic and peripancreatic fat, inflammatory markers, miRNA, and gut microbiota following bariatric surgery. CONCLUSION While this meta-analysis sheds light on possible mechanisms, further studies are necessary to determine the dominant mechanism underlying remission of T2DM following bariatric surgery.
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Affiliation(s)
- Sarah M Russel
- University of Illinois College of Medicine, Chicago, USA.
| | - Valentina Valle
- Department of Surgery, University of Illinois College of Medicine, Chicago, USA
| | - Giuditta Spagni
- Department of Surgery, University of Illinois College of Medicine, Chicago, USA
| | | | - Takshaka Patel
- University of Illinois College of Medicine, Chicago, USA
| | - Nurlan Abdukadyrov
- Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, USA
| | - Yushen Dong
- Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, USA
| | - Antonio Gangemi
- Department of Surgery, University of Illinois College of Medicine, Chicago, USA
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Scotti L, Monteiro AFM, de Oliveira Viana J, Mendonça Junior FJB, Ishiki HM, Tchouboun EN, Santos R, Scotti MT. Multi-Target Drugs Against Metabolic Disorders. Endocr Metab Immune Disord Drug Targets 2020; 19:402-418. [PMID: 30556507 DOI: 10.2174/1871530319666181217123357] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/18/2018] [Accepted: 06/27/2018] [Indexed: 01/13/2023]
Abstract
BACKGROUND Metabolic disorders are a major cause of illness and death worldwide. Metabolism is the process by which the body makes energy from proteins, carbohydrates, and fats; chemically breaking these down in the digestive system towards sugars and acids which constitute the human body's fuel for immediate use, or to store in body tissues, such as the liver, muscles, and body fat. OBJECTIVE The efficiency of treatments for multifactor diseases has not been proved. It is accepted that to manage multifactor diseases, simultaneous modulation of multiple targets is required leading to the development of new strategies for discovery and development of drugs against metabolic disorders. METHODS In silico studies are increasingly being applied by researchers due to reductions in time and costs for new prototype synthesis; obtaining substances that present better therapeutic profiles. DISCUSSION In the present work, in addition to discussing multi-target drug discovery and the contributions of in silico studies to rational bioactive planning against metabolic disorders such as diabetes and obesity, we review various in silico study contributions to the fight against human metabolic pathologies. CONCLUSION In this review, we have presented various studies involved in the treatment of metabolic disorders; attempting to obtain hybrid molecules with pharmacological activity against various targets and expanding biological activity by using different mechanisms of action to treat a single pathology.
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Affiliation(s)
- Luciana Scotti
- Teaching and Research Management - University Hospital, Federal University of Paraíba, João Pessoa, PB, Brazil.,Postgraduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraiba, Joao Pessoa, PB, Brazil
| | - Alex France Messias Monteiro
- Postgraduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraiba, Joao Pessoa, PB, Brazil
| | - Jéssika de Oliveira Viana
- Postgraduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraiba, Joao Pessoa, PB, Brazil
| | - Francisco Jaime Bezerra Mendonça Junior
- Postgraduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraiba, Joao Pessoa, PB, Brazil.,Laboratory of Synthesis and Drug Delivery, Department of Biological Science, State University of Paraiba, Joao Pessoa, PB, Brazil
| | - Hamilton M Ishiki
- University of Western Sao Paulo (Unoeste), Presidente Prudente, SP, Brazil
| | | | - Rodrigo Santos
- Laboratory of Synthesis and Drug Delivery, Department of Biological Science, State University of Paraiba, Joao Pessoa, PB, Brazil
| | - Marcus Tullius Scotti
- Postgraduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraiba, Joao Pessoa, PB, Brazil
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Akalu Y, Molla MD, Dessie G, Ayelign B. Physiological Effect of Ghrelin on Body Systems. Int J Endocrinol 2020; 2020:1385138. [PMID: 32565790 PMCID: PMC7267865 DOI: 10.1155/2020/1385138] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/08/2020] [Accepted: 05/13/2020] [Indexed: 02/06/2023] Open
Abstract
Ghrelin is a relatively novel multifaceted hormone that has been found to exert a plethora of physiological effects. In this review, we found/confirmed that ghrelin has effect on all body systems. It induces appetite; promotes the use of carbohydrates as a source of fuel while sparing fat; inhibits lipid oxidation and promotes lipogenesis; stimulates the gastric acid secretion and motility; improves cardiac performance; decreases blood pressure; and protects the kidneys, heart, and brain. Ghrelin is important for learning, memory, cognition, reward, sleep, taste sensation, olfaction, and sniffing. It has sympatholytic, analgesic, antimicrobial, antifibrotic, and osteogenic effects. Moreover, ghrelin makes the skeletal muscle more excitable and stimulates its regeneration following injury; delays puberty; promotes fetal lung development; decreases thyroid hormone and testosterone; stimulates release of growth hormone, prolactin, glucagon, adrenocorticotropic hormone, cortisol, vasopressin, and oxytocin; inhibits insulin release; and promotes wound healing. Ghrelin protects the body by different mechanisms including inhibition of unwanted inflammation and induction of autophagy. Having a clear understanding of the ghrelin effect in each system has therapeutic implications. Future studies are necessary to elucidate the molecular mechanisms of ghrelin actions as well as its application as a GHSR agonist to treat most common diseases in each system without any paradoxical outcomes on the other systems.
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Affiliation(s)
- Yonas Akalu
- Department of Physiology, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Meseret Derbew Molla
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Gashaw Dessie
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Birhanu Ayelign
- Department of Immunology and Molecular Biology, School of Biomedical and Laboratory Science, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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Mifune H, Tajiri Y, Sakai Y, Kawahara Y, Hara K, Sato T, Nishi Y, Nishi A, Mitsuzono R, Kakuma T, Kojima M. Voluntary exercise is motivated by ghrelin, possibly related to the central reward circuit. J Endocrinol 2020; 244:123-132. [PMID: 31629323 PMCID: PMC6859445 DOI: 10.1530/joe-19-0213] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 01/05/2023]
Abstract
We previously reported that voluntary exercise contributed to the amelioration of abnormal feeding behavior with a concomitant restoration of ghrelin production in a rat model of obesity, suggesting a possible relationship between exercise and appetite-regulating hormones. Ghrelin is known to be involved in the brain reward circuits via dopamine neurons related to motivational properties. We investigated the relevance of ghrelin as an initiator of voluntary exercise as well as feeding behavior. The plasma ghrelin concentration fluctuates throughout the day with its peak at the beginning of the dark period in the wild-type (WT) mice with voluntary exercise. Although predominant increases in wheel running activity were observed accordant to the peak of plasma ghrelin concentration in the WT mice, those were severely attenuated in the ghrelin-knockout (GKO) mice under either ad libitum or time-restricted feeding. A single injection of ghrelin receptor agonist brought about and reproduced a marked enhancement of wheel running activity, in contrast to no effect by the continuous administration of the same drug. Brain dopamine levels (DAs) were enhanced after food consumption in the WT mice under voluntary exercise. Although the acceleration of DAs were apparently blunted in the GKO mice, they were dramatically revived after the administration of ghrelin receptor agonist, suggesting the relevance of ghrelin in the reward circuit under voluntary exercise. These findings emphasize that the surge of ghrelin plays a crucial role in the formation of motivation for the initiation of voluntary exercise possibly related to the central dopamine system.
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Affiliation(s)
- Hiroharu Mifune
- Institute of Animal Experimentation, Kurume University School of Medicine, Kurume, Japan
| | - Yuji Tajiri
- Division of Endocrinology and Metabolism, Kurume University School of Medicine, Kurume, Japan
- Correspondence should be addressed to Y Tajiri:
| | - Yusuke Sakai
- Institute of Animal Experimentation, Kurume University School of Medicine, Kurume, Japan
| | - Yukie Kawahara
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Japan
| | - Kento Hara
- Division of Endocrinology and Metabolism, Kurume University School of Medicine, Kurume, Japan
| | - Takahiro Sato
- Molecular Genetics, Life Science Institute, Kurume University, Kurume, Japan
| | - Yoshihiro Nishi
- Department of Physiology, Kurume University School of Medicine, Kurume, Japan
| | - Akinori Nishi
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Japan
| | - Ryouichi Mitsuzono
- Department of Exercise Physiology, Institute of Health and Sports Science, Kurume University, Kurume, Japan
| | | | - Masayasu Kojima
- Molecular Genetics, Life Science Institute, Kurume University, Kurume, Japan
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Cornejo MP, Castrogiovanni D, Schiöth HB, Reynaldo M, Marie J, Fehrentz JA, Perello M. Growth hormone secretagogue receptor signalling affects high-fat intake independently of plasma levels of ghrelin and LEAP2, in a 4-day binge eating model. J Neuroendocrinol 2019; 31:e12785. [PMID: 31469195 DOI: 10.1111/jne.12785] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/16/2019] [Accepted: 08/27/2019] [Indexed: 12/25/2022]
Abstract
The growth hormone secretagogue receptor (GHSR) is a G protein-coupled receptor that is highly expressed in the central nervous system. GHSR acts as a receptor for ghrelin and for liver-expressed antimicrobial peptide 2 (LEAP2), which blocks ghrelin-evoked activity. GHSR also displays ligand-independent activity, including a high constitutive activity that signals in the absence of ghrelin and is reduced by LEAP2. GHSR activity modulates a variety of food intake-related behaviours, including binge eating. Previously, we reported that GHSR-deficient mice daily and time-limited exposed to a high-fat (HF) diet display an attenuated binge-like HF intake compared to wild-type mice. In the present study, we aimed to determine whether ligand-independent GHSR activity affects binge-like HF intake in a 4-day binge-like eating protocol. We found that plasma levels of ghrelin and LEAP2 were not modified in mice exposed to this binge-like eating protocol. Moreover, systemic administration of ghrelin or LEAP2 did not alter HF intake in our experimental conditions. Interestingly, we found that central administration of LEAP2 or K-(D-1-Nal)-FwLL-NH2 , which are both blockers of constitutive GHSR activity, reduced binge-like HF intake, whereas central administration of ghrelin or the ghrelin-evoked GHSR activity blockers [D-Lys3]-GHRP-6 and JMV2959 did not modify binge-like HF intake. Taken together, current data indicate that GHSR activity in the brain affects binge-like HF intake in mice independently of plasma levels of ghrelin and LEAP2.
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Affiliation(s)
- María Paula Cornejo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata, La Plata, Argentina
| | - Daniel Castrogiovanni
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata, La Plata, Argentina
| | - Helgi B Schiöth
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Mirta Reynaldo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata, La Plata, Argentina
| | - Jacky Marie
- Faculté de Pharmacie, Institut des Biomolécules Max Mousseron, UMR 5247 CNRS-Université Montpellier-ENSCM, Montpellier, France
| | - Jean-Alain Fehrentz
- Faculté de Pharmacie, Institut des Biomolécules Max Mousseron, UMR 5247 CNRS-Université Montpellier-ENSCM, Montpellier, France
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata, La Plata, Argentina
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Löfgren M, Holmberg E, Bäckström T, Egecioglu E, Dickson SL. The additive effect of allopregnanolone on ghrelin's orexigenic effect in rats. Neuropeptides 2019; 76:101937. [PMID: 31253440 DOI: 10.1016/j.npep.2019.101937] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 06/08/2019] [Accepted: 06/12/2019] [Indexed: 11/20/2022]
Abstract
The progesterone metabolite, allopregnanolone (AlloP), is a GABAA receptor modulating steroid and is known to have orexigenic and pro-obesity effects. The neurobiological mechanisms underpinning these effects are most likely due to enhanced GABAergic signaling in the lateral arcuate nucleus (ARC) and medial paraventricular nucleus (PVN) of the hypothalamus. Inspired by the finding that GABAergic signaling is also important for the orexigenic effects of the circulating hormone, ghrelin, we sought to determine the extent to which AlloP (one of the most potent endogenous GABAA-receptor modulators) operates alongside ghrelin to enhance food intake. Male rats with ad libitum access to standard chow were injected intravenously with AlloP and/or ghrelin, alone or in combination. The intake of the standard chow was greater after AlloP 1 mg/kg together with ghrelin 30 μg/kg than with 30 μg/kg ghrelin alone. Food intake was also increased for the combined treatment of AlloP 0.5 mg/kg + ghrelin 10 μg/kg, AlloP 1 mg/kg + ghrelin 10 μg/kg, and AlloP 0.5 mg/kg + ghrelin 30 μg/kg. There was no significant difference in food intake between the two ghrelin doses or between the two doses of AlloP and the vehicle. In electrophysiological studies, physiologically relevant concentrations of AlloP prolonged the current decay time of spontaneous inhibitory post-synaptic current of dissociated cells of the ARC and PVN. We conclude that AlloP enhances the hyperphagic effect of ghrelin, findings of potential relevance for the hyperphagia associated with the luteal phase of the reproductive cycle.
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Affiliation(s)
- Magnus Löfgren
- Department of Clinical Sciences, Obstetrics and Gynaecology, Umeå University Hospital, SE-Building QA, 3rd floor, 901 85 Umeå, Sweden.
| | - Ellinor Holmberg
- Department of Clinical Sciences, Obstetrics and Gynaecology, Umeå University Hospital, SE-Building QA, 3rd floor, 901 85 Umeå, Sweden
| | - Torbjörn Bäckström
- Department of Clinical Sciences, Obstetrics and Gynaecology, Umeå University Hospital, SE-Building QA, 3rd floor, 901 85 Umeå, Sweden
| | - Emil Egecioglu
- Department of Experimental Medical Science, Appetite Regulation Unit, Faculty of Medicine, Lund University, 221 84 Lund, Sweden
| | - Suzanne L Dickson
- Institute for Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, P.O. Box 434, SE-405 30 Gothenburg, Sweden
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74
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Vestlund J, Bergquist F, Eckernäs D, Licheri V, Adermark L, Jerlhag E. Ghrelin signalling within the rat nucleus accumbens and skilled reach foraging. Psychoneuroendocrinology 2019; 106:183-194. [PMID: 30999229 DOI: 10.1016/j.psyneuen.2019.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/12/2019] [Accepted: 04/06/2019] [Indexed: 01/23/2023]
Abstract
Motivation alters behaviour in a complex manner and nucleus accumbens (NAc) shell has been implied as a key structure regulating such behaviour. Recent studies show that acute ghrelin signalling enhances motivation when assessed in a simple motor task. The aim of the present study was to define the role of ghrelin signalling on motivation in a more complex motor behaviour. Rats were tested in the Montoya staircase, an animal model of skilled reach foraging assessed by the number of sucrose pellets consumed. Electrophysiological recordings were conducted to explore the neurophysiological correlates of ghrelin signalling. The initial electrophysiological results displayed that ex vivo administration of ghrelin increased NAc shell output in brain slices from drug- and training-naïve rats. In rats with an acquired skilled reach performance, acute as well as repeated treatment with a ghrelin receptor (GHSR-1 A) antagonist (JMV2959) decreased the number of sucrose pellets consumed. Moreover, infusion of JMV2959 into NAc shell reduced this consumption. Sub-chronic, during ten days, JMV2959 treatment during training on the Montoya staircase reduced the number of pellets consumed, whereas ghrelin improved this behaviour. In addition, field potential and whole cell recordings were conducted in NAc shell of rats that had been treated with ghrelin or GHSR-1 A antagonist during training on the Montoya staircase. Sub-chronic administration of ghrelin during motor-skill learning selectively increased the frequency of inhibitory transmission in the NAc shell, resulting in a net suppression of accumbal output. Collectively these data suggest that ghrelin signalling in NAc shell enhances skilled reached foraging tentatively by increasing the motivation.
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Affiliation(s)
- Jesper Vestlund
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Filip Bergquist
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Daniel Eckernäs
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Valentina Licheri
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Louise Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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75
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Bake T, Edvardsson CE, Cummings CJ, Dickson SL. Ghrelin's effects on food motivation in rats are not limited to palatable foods. J Neuroendocrinol 2019; 31:e12665. [PMID: 30525248 PMCID: PMC6767751 DOI: 10.1111/jne.12665] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/17/2018] [Accepted: 11/29/2018] [Indexed: 12/20/2022]
Abstract
The "hunger" hormone, ghrelin, is powerfully orexigenic. Even in the absence of hunger, ghrelin delivery to rats increases consumption of chow, as well as palatable foods, and increases motivated behaviour for palatable food rewards. Inspired by the finding that ghrelin increases the selection of chow in rats offered a choice diet (lard, sucrose or chow) and even in rats bingeing on a high-fat diet, we aimed to explore whether the effects of ghrelin on motivation extend to regular chow. Rats were conditioned to lever press for either chow or sucrose pellets in a progressive ratio (PR) operant conditioning task. The effect of acute i.c.v. delivery of ghrelin on both chow and sucrose self-administration was determined and compared with overnight fasting (ie, when endogenous ghrelin levels are elevated). We found that ghrelin similarly increased motivated behaviour for chow and sucrose pellets. The effect of fasting on motivated behaviour for both food pellets was comparable in magnitude to that induced by ghrelin, albeit with an earlier ceiling effect during the PR session. Devaluation experiments (in which rats are offered either food reinforcer in excess prior to PR testing) did not support the hypothesis that sucrose pellets would be more difficult to devalue (as a result of their higher incentive value) than chow pellets. When exchanging the respective pellets during a PR session, chow-conditioned rats were more motivated for sucrose pellets compared to chow pellets; however, sucrose-conditioned rats were similarly motivated for chow pellets compared to sucrose pellets. Thus, using sucrose as a reward may increase the motivation even for less palatable foods. We conclude that the impact of ghrelin on food-motivated behaviour in fed rats is not limited to palatable foods but extends to regular chow, and also that the magnitude of the effect is considerable compared to that of an overnight fast.
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Affiliation(s)
- Tina Bake
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
| | - Christian E. Edvardsson
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
| | - Cameron J. Cummings
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
| | - Suzanne L. Dickson
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
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76
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Perello M, Cabral A, Cornejo MP, De Francesco PN, Fernandez G, Uriarte M. Brain accessibility delineates the central effects of circulating ghrelin. J Neuroendocrinol 2019; 31:e12677. [PMID: 30582239 DOI: 10.1111/jne.12677] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/04/2018] [Accepted: 12/04/2018] [Indexed: 12/27/2022]
Abstract
Ghrelin is a hormone produced in the gastrointestinal tract that acts via the growth hormone secretagogue receptor. In the central nervous system, ghrelin signalling is able to recruit different neuronal targets that regulate the behavioural, neuroendocrine, metabolic and autonomic effects of the hormone. Notably, several studies using radioactive or fluorescent variants of ghrelin have found that the accessibility of circulating ghrelin into the mouse brain is both strikingly low and restricted to some specific brain areas. A variety of studies addressing central effects of systemically injected ghrelin in mice have also provided indirect evidence that the accessibility of plasma ghrelin into the brain is limited. Here, we review these previous observations and discuss the putative pathways that would allow plasma ghrelin to gain access into the brain together with their physiological implications. Additionally, we discuss some potential features regarding the accessibility of plasma ghrelin into the human brain based on the observations reported by studies that investigate the consequences of ghrelin administration to humans.
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Affiliation(s)
- Mario Perello
- Laboratorio de Neurofisiología del Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional de La Plata y Comisión de Investigaciones Científicas-Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Agustina Cabral
- Laboratorio de Neurofisiología del Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional de La Plata y Comisión de Investigaciones Científicas-Provincia de Buenos Aires, Buenos Aires, Argentina
| | - María P Cornejo
- Laboratorio de Neurofisiología del Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional de La Plata y Comisión de Investigaciones Científicas-Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Pablo N De Francesco
- Laboratorio de Neurofisiología del Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional de La Plata y Comisión de Investigaciones Científicas-Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Gimena Fernandez
- Laboratorio de Neurofisiología del Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional de La Plata y Comisión de Investigaciones Científicas-Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Maia Uriarte
- Laboratorio de Neurofisiología del Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional de La Plata y Comisión de Investigaciones Científicas-Provincia de Buenos Aires, Buenos Aires, Argentina
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77
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Abizaid A. Stress and obesity: The ghrelin connection. J Neuroendocrinol 2019; 31:e12693. [PMID: 30714236 DOI: 10.1111/jne.12693] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/01/2019] [Accepted: 01/29/2019] [Indexed: 12/20/2022]
Abstract
Ghrelin is a hormone associated with feeding and energy balance. Not surprisingly, this hormone is secreted in response to acute stressors and it is chronically elevated after exposure to chronic stress in tandem with a number of metabolic changes aimed at attaining homeostatic balance. In the present review, we propose that ghrelin plays a key role in these stress-induced homeostatic processes. Ghrelin targets the hypothalamus and brain stem nuclei that are part of the sympathetic nervous system to increase appetite and energy expenditure and promote the use of carbohydrates as a source of fuel at the same time as sparing fat. Ghrelin also targets mesolimbic brain regions such as the ventral segmental area and the hippocampus to modulate reward processes, to protect against damage associated with chronic stress, as well as to potentially increase resilience to stress. In all, these data support the notion that ghrelin, similar to corticosterone, is a critical metabolic hormone that is essential for the stress response.
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Affiliation(s)
- Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
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78
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Neuro-hormonal mechanisms underlying changes in reward related behaviors following weight loss surgery: Potential pharmacological targets. Biochem Pharmacol 2019; 164:106-114. [DOI: 10.1016/j.bcp.2019.04.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/03/2019] [Indexed: 12/11/2022]
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79
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Serrenho D, Santos SD, Carvalho AL. The Role of Ghrelin in Regulating Synaptic Function and Plasticity of Feeding-Associated Circuits. Front Cell Neurosci 2019; 13:205. [PMID: 31191250 PMCID: PMC6546032 DOI: 10.3389/fncel.2019.00205] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 04/24/2019] [Indexed: 12/21/2022] Open
Abstract
Synaptic plasticity of the neuronal circuits associated with feeding behavior is regulated by peripheral signals as a response to changes in the energy status of the body. These signals include glucose, free fatty acids, leptin and ghrelin and are released into circulation, being able to reach the brain. Ghrelin, a small peptide released from the stomach, is an orexigenic hormone produced in peripheral organs, and its action regulates food intake, body weight and glucose homeostasis. Behavioral studies show that ghrelin is implicated in the regulation of both hedonic and homeostatic feeding and of cognition. Ghrelin-induced synaptic plasticity has been described in neuronal circuits associated with these behaviors. In this review, we discuss the neuromodulatory mechanisms induced by ghrelin in regulating synaptic plasticity in three main neuronal circuits previously associated with feeding behaviors, namely hypothalamic (homeostatic feeding), ventral tegmental (hedonic and motivational feeding) and hippocampal (cognitive) circuits. Given the central role of ghrelin in regulating feeding behaviors, and the altered ghrelin levels associated with metabolic disorders such as obesity and anorexia, it is of paramount relevance to understand the effects of ghrelin on synaptic plasticity of neuronal circuits associated with feeding behaviors.
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Affiliation(s)
- Débora Serrenho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal.,PhD Program in Experimental Biology and Biomedicine (PDBEB), University of Coimbra, Coimbra, Portugal
| | - Sandra D Santos
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - Ana Luísa Carvalho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Department of Life Sciences, University of Coimbra, Coimbra, Portugal
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80
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Kirsch M. On the Abilities of Unconscious Freudian Motivational Drives to Evoke Conscious Emotions. Front Psychol 2019; 10:470. [PMID: 30899234 PMCID: PMC6416170 DOI: 10.3389/fpsyg.2019.00470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/18/2019] [Indexed: 12/27/2022] Open
Abstract
Human beings use conscious emotions to direct their behaviors. There is some agreement in the scientific community that unconscious motivations are able to evoke conscious emotions. This manuscript focuses on Freudian motivational drives as inductors for unconscious motivation, and also on Panksepp's framework of affective neuroscience for describing the generation of emotions. Recently, it has been suggested that imperative motor factors of Freudian drives (i.e., the hormones ghrelin, testosterone, angiotensin II and adenosine) have the ability to activate both a drive-specific brain area and brain areas of the SEEKING command system. In fact, this manuscript contends that all imperative motor factors have typical SEEKING targets (i.e., so-called receptors) in the brain areas of both nucleus accumbens and lateral hypothalamus. In addition, all imperative motor factors are able to target the central amygdala directly, a brain area classified by Panksepp as the instinctual part of the FEAR command system. Another point of interest may be the evaluation that imperative motor factors of the sexual drive, hunger and thirst can directly activate the RAGE command system by targeting the medial amygdala. Surprisingly, all imperative motor factors are able to modulate Panksepp's granddaddy mechanism, i.e., to stimulate all seven command systems via the lateral hypothalamus. Orexinergic neurons exclusively located in the lateral hypothalamus have targets for imperative motor factors and project axons to characteristic brain areas of all seven command systems. From the fact that the imperative motor factors of the sexual drive and hunger act in an excitatory manner on orexinergic neurons whereas those of thirst and sleep inhibit such neurons, temporary termination of hunger by thirst may be understood as a very simple example of a co-regulation of Freudian drives. The author wishes to note that there are motivational drives other than the ones described by Freud. Bowlby was obviously the first in describing such drives, and Bowlbyian drive activities cannot be explained with the intermediacy of imperative motor factors. Nevertheless, the ignorance of the magnificent importance of imperative motor factors must be discarded.
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Affiliation(s)
- Michael Kirsch
- Institute of Physiological Chemistry, Essen University Hospital, Essen, Germany
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81
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Al Massadi O, Nogueiras R, Dieguez C, Girault JA. Ghrelin and food reward. Neuropharmacology 2019; 148:131-138. [PMID: 30615902 DOI: 10.1016/j.neuropharm.2019.01.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 01/02/2019] [Accepted: 01/02/2019] [Indexed: 12/14/2022]
Abstract
Food intake is tightly regulated by homeostatic and reward mechanisms and the adequate function of both is necessary for the proper maintenance of energy balance. Ghrelin impacts on these two levels to induce feeding. In this review, we present the actions of ghrelin in food reward, including their dependence on other relevant modulators implicated in the motivational aspects of feeding, including dopamine, opioid peptides, and endocannabinoids. We also describe the interaction between brain areas involved in homeostatic regulation of feeding and the reward system, with a special emphasis on the role of arcuate nucleus melanocortins and lateral hypothalamus orexins in ghrelin function. Finally, we briefly discuss the actions of ghrelin in food reward in obesity. We propose that new insights into the mechanism of action of ghrelin in the rewarding and motivational control of food intake will help to understand food-related disorders including obesity and anorexia.
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Affiliation(s)
- Omar Al Massadi
- Inserm UMR-S 839, 75005, Paris, France; Sorbonne Université, Sciences and Engineering Faculty, 75005 Paris, France; Institut du Fer a Moulin, 75005, Paris, France.
| | - Ruben Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain
| | - Carlos Dieguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain
| | - Jean-Antoine Girault
- Inserm UMR-S 839, 75005, Paris, France; Sorbonne Université, Sciences and Engineering Faculty, 75005 Paris, France; Institut du Fer a Moulin, 75005, Paris, France
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82
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Divergent associations between ghrelin and neural responsivity to palatable food in hyperphagic and hypophagic depression. J Affect Disord 2019; 242:29-38. [PMID: 30170236 PMCID: PMC6151278 DOI: 10.1016/j.jad.2018.07.088] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 07/10/2018] [Accepted: 07/31/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND The neurobiological mechanisms involved in divergent appetitive phenotypes in major depressive disorder (MDD) are not well understood, although recent data suggest disruption in mesolimbic reward circuitry. Ghrelin, an orexigenic hormone, has been shown to modulate the reward circuitry. We aimed to investigate the relationship between acylated ghrelin levels and the neural response to food stimuli in individuals with hyperphagic and hypophagic MDD in remission. METHODS Women with hyperphagic MDD (n = 10), hypophagic MDD (n = 18), and healthy controls (HC; n = 18) underwent fMRI scanning during which they viewed images of food. The fMRI session was followed by a standardized meal, appetite ratings, and serial blood draws. RESULTS In individuals with hyperphagic MDD, greater change in acylated ghrelin in response to a meal was associated with increased BOLD response to high-calorie food in the bilateral ventral tegmental area and left hypothalamus. In contrast, negative associations were observed between acylated ghrelin AUC and BOLD activity in the right hypothalamus in the hypophagic MDD group. LIMITATIONS Unbalanced group sizes with a relatively small sample in the hyperphagic MDD group. CONCLUSIONS In the absence of differences in absolute ghrelin levels between the hyperphagic MDD and HC groups, results in hyperphagic MDD might suggest a ghrelinergic signaling mechanism for increased appetite during an MDD episode in this group. Our findings shed light on interactions between appetite hormones and mesolimbic circuitry which could contribute to development of therapeutic targets for opposing appetite phenotypes in depression.
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83
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Sleep Deprivation Selectively Upregulates an Amygdala-Hypothalamic Circuit Involved in Food Reward. J Neurosci 2018; 39:888-899. [PMID: 30559151 DOI: 10.1523/jneurosci.0250-18.2018] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 09/18/2018] [Accepted: 10/15/2018] [Indexed: 01/30/2023] Open
Abstract
Sleep loss is associated with increased obesity risk, as demonstrated by correlations between sleep duration and change in body mass index or body fat percentage. Whereas previous studies linked this weight gain to disturbed endocrine parameters after sleep deprivation or restriction, neuroimaging studies revealed upregulated neural processing of food rewards after sleep loss in reward-processing areas such as the anterior cingulate cortex, ventral striatum, and insula. To address this ongoing debate between hormonal versus hedonic factors underlying sleep-loss-associated weight gain, we rigorously tested the association between sleep deprivation and food cue processing using high-resolution fMRI and assessment of hormones. After taking blood samples from 32 lean, healthy, human male participants, they underwent fMRI while performing a neuroeconomic, value-based decision-making task with snack food and trinket rewards following a full night of habitual sleep and a night of sleep deprivation in a repeated-measures crossover design. We found that des-acyl ghrelin concentrations were increased after sleep deprivation compared with habitual sleep. Despite similar hunger ratings due to fasting in both conditions, participants were willing to spend more money on food items only after sleep deprivation. Furthermore, fMRI data paralleled this behavioral finding, revealing a food-reward-specific upregulation of hypothalamic valuation signals and amygdala-hypothalamic coupling after a single night of sleep deprivation. Behavioral and fMRI results were not significantly correlated with changes in acyl, des-acyl, or total ghrelin concentrations. Our results suggest that increased food valuation after sleep loss might be due to hedonic rather than hormonal mechanisms.SIGNIFICANCE STATEMENT Epidemiological studies suggest an association between overweight and reduced nocturnal sleep, but the relative contributions of hedonic and hormonal factors to overeating after sleep loss are a matter of ongoing controversy. Here, we tested the association between sleep deprivation and food cue processing in a repeated-measures crossover design using fMRI. We found that willingness to pay increased for food items only after sleep deprivation. fMRI data paralleled this behavioral finding, revealing a food-reward-specific upregulation of hypothalamic valuation signals and amygdala-hypothalamic coupling after a single night of sleep deprivation. However, there was no evidence for hormonal modulations of behavioral or fMRI findings. Our results suggest that increased food valuation after sleep loss is due to hedonic rather than hormonal mechanisms.
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84
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Cornejo MP, Barrile F, De Francesco PN, Portiansky EL, Reynaldo M, Perello M. Ghrelin Recruits Specific Subsets of Dopamine and GABA Neurons of Different Ventral Tegmental Area Sub-nuclei. Neuroscience 2018; 392:107-120. [DOI: 10.1016/j.neuroscience.2018.09.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/10/2018] [Accepted: 09/19/2018] [Indexed: 11/30/2022]
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85
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Wittekind DA, Kratzsch J, Mergl R, Enzenbach C, Witte AV, Villringer A, Kluge M. Alcohol consumption is positively associated with fasting serum ghrelin in non-dependent adults: Results from the population-based LIFE-Adult-Study. Psychoneuroendocrinology 2018; 97:143-148. [PMID: 30029157 DOI: 10.1016/j.psyneuen.2018.07.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/03/2018] [Accepted: 07/13/2018] [Indexed: 02/01/2023]
Abstract
BACKGROUND Animal experiments and studies in alcohol dependent patients indicate that ghrelin signaling in the brain is causally involved in the regulation of alcohol reward and intake. Increasing ghrelin levels enhances alcohol craving and intake, blocking ghrelin receptors abolishes these effects. If ghrelin is also involved in non-dependent alcohol consumption in humans, though, remains unknown. The aim was therefore to investigate the relationship between ghrelin serum levels and alcohol consumption in a large population-based sample. METHODS Total ghrelin was determined after an overnight fast in 1666 subjects participating in a population-based cross-sectional study ('LIFE') including 10,000 adults. 1521 subjects were included in this analysis. Alcohol consumption was assessed using a food frequency questionnaire (FFQ). Multiple linear regression analyses and extreme group comparisons testing for statistical differences of alcohol consumption between the highest and lowest quartile according to ghrelin levels were performed. RESULTS Alcohol consumption was positively associated with serum ghrelin; total sample: β = 0.003, p = 0.002; men: β = 0.005, p = 0.023; women: β = 0.002, p = 0.007, adjusted for age, BMI and smoking status. Mean alcohol consumption in men/women belonging to the highest quartile of serum ghrelin levels (men: 21.5 (21.1) g/day; women: 7.5 (11.4) g/day) was considerably higher than in those belonging to the lowest quartile (men: 16.5 (19.3) g/day p < 0.002; women: 4.59 (10.7) g/day p = 0.0001). CONCLUSION This is the first study showing that alcohol consumption is positively associated with serum ghrelin in a population-based sample. The study provides an initial indication that ghrelin is also involved in the regulation of alcohol consumption in non-dependent subjects.
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Affiliation(s)
| | - Jürgen Kratzsch
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany
| | - Roland Mergl
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Cornelia Enzenbach
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), University of Leipzig, Leipzig, Germany
| | - A Veronica Witte
- Department of Neurology, Max Planck Institute for Cognitive and Brain Sciences, Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Cognitive and Brain Sciences, Leipzig, Germany
| | - Michael Kluge
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
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86
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Sztainert T, Hay R, Wohl MJA, Abizaid A. Hungry to gamble? Ghrelin as a predictor of persistent gambling in the face of loss. Biol Psychol 2018; 139:115-123. [PMID: 30392826 DOI: 10.1016/j.biopsycho.2018.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 10/18/2018] [Accepted: 10/18/2018] [Indexed: 01/08/2023]
Abstract
Ghrelin, a peptide hormone associated with appetite, is also linked to increased reward seeking behaviors, including food, sex, and drug seeking behaviors through the stimulation of the mesolimbic dopaminergic system. Moreover, plasma ghrelin concentrations are increased by cues that predict rewards, suggesting that cues could facilitate cravings and ultimately relapse. In this project we examined the effects of an overnight fast, a manipulation known to increase ghrelin concentrations, on gambling behaviors. We also examined if cues associated with gambling would also increase ghrelin and, if so, we examined if these increases were associated with gambling behavior. One hundred and one (37 females) participants were asked to fast overnight or after breakfast and then asked to complete food and gambling craving questionnaires. Participants were then presented with gambling cues (a casino like environment in the lab) or a control cue (a cubicle with a computer). After the cue, subjects filled gambling craving questionnaires, and were allowed to gamble. Following 25 practice spins, the slot machines were fixed so that all subsequent spins were losses, and the number of spins in spite of losses were quantified. Blood samples were collected throughout the experiment. Results showed that the gambling cues significantly increased ghrelin concentrations particularly in fasted individuals, and that ghrelin concentrations 20 min after the cue were the best predictor for gambling persistence in the face of continued loss (p < 0.05). Our results suggest that cues that predict the opportunity to gamble have an acute effect on ghrelin concentrations that is facilitated by fasting, and that ghrelin concentrations are a significant predictor of gambling persistence.
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Affiliation(s)
| | - Rebecca Hay
- Carleton University Department of Neuroscience, Canada
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87
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Exogenous ghrelin administration increases alcohol self-administration and modulates brain functional activity in heavy-drinking alcohol-dependent individuals. Mol Psychiatry 2018; 23:2029-2038. [PMID: 29133954 DOI: 10.1038/mp.2017.226] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 07/17/2017] [Accepted: 08/07/2017] [Indexed: 12/21/2022]
Abstract
Preclinical evidence suggests that ghrelin, a peptide synthesized by endocrine cells of the stomach and a key component of the gut-brain axis, is involved in alcohol seeking as it modulates both central reward and stress pathways. However, whether and how ghrelin administration may impact alcohol intake in humans is not clear. For, we believe, the first time, this was investigated in the present randomized, crossover, double-blind, placebo-controlled, human laboratory study. Participants were non-treatment-seeking alcohol-dependent heavy-drinking individuals. A 10-min loading dose of intravenous ghrelin/placebo (3 mcg kg-1) followed by a continuous ghrelin/placebo infusion (16.9 ng/kg/min) was administered. During a progressive-ratio alcohol self-administration experiment, participants could press a button to receive intravenous alcohol using the Computerized Alcohol Infusion System. In another experiment, brain functional magnetic resonance imaging was conducted while participants performed a task to gain points for alcohol, food or no reward. Results showed that intravenous ghrelin, compared to placebo, significantly increased the number of alcohol infusions self-administered (percent change: 24.97±10.65, P=0.04, Cohen's d=0.74). Participants were also significantly faster to initiate alcohol self-administration when they received ghrelin, compared to placebo (P=0.03). The relationships between breath alcohol concentration and subjective effects of alcohol were also moderated by ghrelin administration. Neuroimaging data showed that ghrelin increased the alcohol-related signal in the amygdala (P=0.01) and modulated the food-related signal in the medial orbitofrontal cortex (P=0.01) and nucleus accumbens (P=0.08). These data indicate that ghrelin signaling affects alcohol seeking in humans and should be further investigated as a promising target for developing novel medications for alcohol use disorder.
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88
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Naish KR, Laliberte M, MacKillop J, Balodis IM. Systematic review of the effects of acute stress in binge eating disorder. Eur J Neurosci 2018; 50:2415-2429. [DOI: 10.1111/ejn.14110] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/03/2018] [Accepted: 08/07/2018] [Indexed: 12/01/2022]
Affiliation(s)
- Katherine R. Naish
- Peter Boris Centre for Addictions Research Department of Psychiatry and Behavioural Neurosciences McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
| | - Michele Laliberte
- Peter Boris Centre for Addictions Research Department of Psychiatry and Behavioural Neurosciences McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
- Eating Disorders Clinic St. Joseph's Healthcare Hamilton Hamilton ON Canada
- Michael G. DeGroote Centre for Medicinal Cannabis Research Michael G. DeGroote School of Medicine McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
| | - James MacKillop
- Peter Boris Centre for Addictions Research Department of Psychiatry and Behavioural Neurosciences McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
- Michael G. DeGroote Centre for Medicinal Cannabis Research Michael G. DeGroote School of Medicine McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
| | - Iris M. Balodis
- Peter Boris Centre for Addictions Research Department of Psychiatry and Behavioural Neurosciences McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
- Michael G. DeGroote Centre for Medicinal Cannabis Research Michael G. DeGroote School of Medicine McMaster University and St. Joseph's Healthcare Hamilton Hamilton ON Canada
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89
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Ralevski E, Shanabrough M, Newcomb J, Gandelman E, Hayden R, Horvath TL, Petrakis I. Ghrelin is Related to Personality Differences in Reward Sensitivity and Impulsivity. Alcohol Alcohol 2018; 53:52-56. [PMID: 29136100 DOI: 10.1093/alcalc/agx082] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/26/2017] [Indexed: 01/15/2023] Open
Abstract
Aims Ghrelin, a feeding-related peptide mainly produced in the stomach, has been linked to reward mechanisms for food and drugs of abuse in addition to traits of impulsivity. This study is a secondary analysis of an existing data set designed to examine the direct relationships between fasting ghrelin levels and reward sensitivity/impulsivity in healthy social drinkers. Methods Participants (n = 20) were recruited from an original study examining the subjective effects of alcohol among social drinkers. Fasting ghrelin levels were collected at baseline. Personality measures (Behavioral Inhibition, Behavioral Activation, and Affective Response to Impending Reward and Punishment and Barratt Impulsiveness Scale) were administered at baseline to evaluate sensitivity to reward and punishment, and measure traits of impulsivity, respectively. Results Fasting ghrelin levels were significantly related to reward sensitivity and impulsivity traits. Specifically, those with higher ghrelin levels were more sensitive to reward and were more impulsive (have lower self-control). Conclusions The results indicate that individuals with higher levels of ghrelin are more sensitive to reward. In addition, they are less able to exercise self-control and to an extent more likely to act without thinking. This is the first study to report on the direct relationship between fasting ghrelin levels and personality characteristics such as reward sensitivity and aspects of impulsivity among healthy social drinkers. Short summary Individuals with higher levels of fasting ghrelin are more sensitive to reward, but less sensitive to punishment. Higher ghrelin levels are also related to some aspects of impulsivity such as decreased self-control and increased likelihood of acting without thinking.
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Affiliation(s)
- Elizabeth Ralevski
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT.,Department of Veterans Affairs, VA Connecticut Healthcare System, Psychiatry Service (116A), West Haven, CT 06516, USA.,Mental Illness Research and Clinical Center, VA Connecticut Healthcare System, 950 Campbell Ave., West Haven, CT
| | - Marya Shanabrough
- Program of Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, 333 Cedar St., New Haven, CT
| | - Jenelle Newcomb
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT.,Department of Veterans Affairs, VA Connecticut Healthcare System, Psychiatry Service (116A), West Haven, CT 06516, USA.,Mental Illness Research and Clinical Center, VA Connecticut Healthcare System, 950 Campbell Ave., West Haven, CT
| | - Erin Gandelman
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT.,Department of Veterans Affairs, VA Connecticut Healthcare System, Psychiatry Service (116A), West Haven, CT 06516, USA
| | - Ryan Hayden
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT.,Present address: Department of Pediatrics, Virginia Commonwealth University, 1000 E Broad St., Richmond, VA
| | - Tamas L Horvath
- Program of Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, 333 Cedar St., New Haven, CT.,Department of Obstetrics/Gynecology and Reproductive Sciences, Yale University School of Medicine, 333 Cedar St., New Haven, CT
| | - Ismene Petrakis
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT.,Department of Veterans Affairs, VA Connecticut Healthcare System, Psychiatry Service (116A), West Haven, CT 06516, USA.,Mental Illness Research and Clinical Center, VA Connecticut Healthcare System, 950 Campbell Ave., West Haven, CT
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90
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Kirsch M, Mertens W. On the Drive Specificity of Freudian Drives for the Generation of SEEKING Activities: The Importance of the Underestimated Imperative Motor Factor. Front Psychol 2018; 9:616. [PMID: 29774002 PMCID: PMC5943553 DOI: 10.3389/fpsyg.2018.00616] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 04/12/2018] [Indexed: 12/19/2022] Open
Abstract
Doubters of Freud's theory of drives frequently mentioned that his approach is outdated and therefore cannot be useful for solving current problems in patients with mental disorders. At present, many scientists believe that affects rather than drives are of utmost importance for the emotional life and the theoretical framework of affective neuroscience, developed by Panksepp, strongly underpinned this view. Panksepp evaluated seven so-called command systems and the SEEKING system is therein of central importance. Panksepp used Pankseppian drives as inputs for the SEEKING system but noted the missing explanation of drive-specific generation of SEEKING activities in his description. Drive specificity requires dual action of the drive: the activation of a drive-specific brain area and the release of the neurotransmitter dopamine. Noticeably, as Freud claimed drive specificity too, it was here analyzed whether a Freudian drive can evoke the generation of drive-specific SEEKING activities. Special importance was addressed to the imperative motor factor in Freud's drive theory because Panksepp's formulations focused on neural pathways without specifying underlying neurotransmitter/endocrine factors impelling motor activity. As Panksepp claimed sleep as a Pankseppian drive, we firstly had to classified sleep as a Freudian drive by using three evaluated criteria for a Freudian drive. After that it was possible to identify the imperative motor factors of hunger, thirst, sex, and sleep. Most importantly, all of these imperative motor factors can both activate a drive-specific brain area and release dopamine from dopaminergic neurons, i.e., they can achieve the so-called drive specificity. Surprisingly, an impaired Freudian drive can alter via endocrinological pathways the concentration of the imperative motor factor of a second Freudian drive, obviously in some independence to the level of the metabolic deficit, thereby offering the possibility to modulate the generation of SEEKING activities of this second Freudian drive. This novel possibility might help to refine the general understanding of the action of Freudian drives. As only imperative motor factors of Freudian drives can guarantee drive specificity for the generation of SEEKING activities, the impact of Freud's construct Eros (with its constituents hunger, thirst, sex, and sleep) should be revisited.
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Affiliation(s)
- Michael Kirsch
- Institute of Physiological Chemistry, University Hospital Essen, Essen, Germany
| | - Wolfgang Mertens
- Division of Clinical Psychology and Psychotherapy, Department of Psychology, Faculty of Psychology and Educational Sciences, Ludwig Maximilian University of Munich, Munich, Germany
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91
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Jang JK, Kim WY, Cho BR, Lee JW, Kim JH. Locomotor sensitization is expressed by ghrelin and D1 dopamine receptor agonist in the nucleus accumbens core in amphetamine pre-exposed rat. Addict Biol 2018. [PMID: 28635134 DOI: 10.1111/adb.12533] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ghrelin modulates mesolimbic dopaminergic pathways in the brain in addition to its role in feeding. We investigated what roles ghrelin in the nucleus accumbens (NAcc) core may play in mediating locomotor activating effects of amphetamine (AMPH). First, when rats were administered with AMPH (1 mg/kg, i.p.) following a bilateral microinjection of ghrelin (0.1 or 0.5 μg/side) into the NAcc core, their locomotor activity was significantly enhanced, while these effects were blocked by co-microinjection of ghrelin receptor antagonist (0.5 μg/side) into this site. Second, we pre-exposed rats to saline or amphetamine (1 mg/kg, i.p.) every 2 to 3 days for a total of four times. After 2 weeks of drug-free withdrawal period, we examined the effect of saline, ghrelin (0.5 μg/side), D1 dopamine receptor agonist, SKF81297 (0.5 μg/side) or ghrelin (0.5 μg/side) + SKF81297 (0.5 μg/side) directly microinjected into the NAcc core on locomotor activity. When we measured rats' locomotor activity for 1 hour immediately following microinjections, only ghrelin + SKF81297 produces sensitized locomotor activity, while all others have no effects. These results suggest that ghrelin may have a distinct role in the NAcc core to provoke the sensitized locomotor activity induced by psychomotor stimulants, and further, it may produce these effects by interaction with D1 dopamine receptors.
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Affiliation(s)
- Ju Kyong Jang
- Department of Physiology, Brain Korea 21 Plus Project for Medical Science; Brain Research Institute, Yonsei University College of Medicine; Seoul South Korea
| | - Wha Young Kim
- Department of Physiology, Brain Korea 21 Plus Project for Medical Science; Brain Research Institute, Yonsei University College of Medicine; Seoul South Korea
| | - Bo Ram Cho
- Department of Physiology, Brain Korea 21 Plus Project for Medical Science; Brain Research Institute, Yonsei University College of Medicine; Seoul South Korea
| | - Jung Won Lee
- Department of Physiology, Brain Korea 21 Plus Project for Medical Science; Brain Research Institute, Yonsei University College of Medicine; Seoul South Korea
| | - Jeong-Hoon Kim
- Department of Physiology, Brain Korea 21 Plus Project for Medical Science; Brain Research Institute, Yonsei University College of Medicine; Seoul South Korea
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92
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Coccurello R, Maccarrone M. Hedonic Eating and the "Delicious Circle": From Lipid-Derived Mediators to Brain Dopamine and Back. Front Neurosci 2018; 12:271. [PMID: 29740277 PMCID: PMC5928395 DOI: 10.3389/fnins.2018.00271] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/09/2018] [Indexed: 01/09/2023] Open
Abstract
Palatable food can be seductive and hedonic eating can become irresistible beyond hunger and negative consequences. This is witnessed by the subtle equilibrium between eating to provide energy intake for homeostatic functions, and reward-induced overeating. In recent years, considerable efforts have been devoted to study neural circuits, and to identify potential factors responsible for the derangement of homeostatic eating toward hedonic eating and addiction-like feeding behavior. Here, we examined recent literature on “old” and “new” players accountable for reward-induced overeating and possible liability to eating addiction. Thus, the role of midbrain dopamine is positioned at the intersection between selected hormonal signals involved in food reward information processing (namely, leptin, ghrelin, and insulin), and lipid-derived neural mediators such as endocannabinoids. The impact of high fat palatable food and dietary lipids on endocannabinoid formation is reviewed in its pathogenetic potential for the derangement of feeding homeostasis. Next, endocannabinoid signaling that regulates synaptic plasticity is discussed as a key mechanism acting both at hypothalamic and mesolimbic circuits, and affecting both dopamine function and interplay between leptin and ghrelin signaling. Outside the canonical hypothalamic feeding circuits involved in energy homeostasis and the notion of “feeding center,” we focused on lateral hypothalamus as neural substrate able to confront food-associated homeostatic information with food salience, motivation to eat, reward-seeking, and development of compulsive eating. Thus, the lateral hypothalamus-ventral tegmental area-nucleus accumbens neural circuitry is reexamined in order to interrogate the functional interplay between ghrelin, dopamine, orexin, and endocannabinoid signaling. We suggested a pivotal role for endocannabinoids in food reward processing within the lateral hypothalamus, and for orexin neurons to integrate endocrine signals with food reinforcement and hedonic eating. In addition, the role played by different stressors in the reinstatement of preference for palatable food and food-seeking behavior is also considered in the light of endocannabinoid production, activation of orexin receptors and disinhibition of dopamine neurons. Finally, type-1 cannabinoid receptor-dependent inhibition of GABA-ergic release and relapse to reward-associated stimuli is linked to ghrelin and orexin signaling in the lateral hypothalamus-ventral tegmental area-nucleus accumbens network to highlight its pathological potential for food addiction-like behavior.
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Affiliation(s)
- Roberto Coccurello
- Department of Biomedical Sciences, Institute of Cell Biology and Neurobiology, National Research Council, Rome, Italy.,Laboratory of Neurochemistry of Lipids, European Center for Brain Research (CERC), IRRCS Santa Lucia Foundation, Rome, Italy
| | - Mauro Maccarrone
- Laboratory of Neurochemistry of Lipids, European Center for Brain Research (CERC), IRRCS Santa Lucia Foundation, Rome, Italy.,Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
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93
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Abstract
Ghrelin, a gastric-derived acylated peptide, regulates energy homeostasis by transmitting information about peripheral nutritional status to the brain, and is essential for protecting organisms against famine. Ghrelin operates brain circuits to regulate homeostatic and hedonic feeding. Recent research advances have shed new light on ghrelin's multifaceted roles in cellular homeostasis, which could maintain the internal environment and overcome metaflammation in metabolic organs. Here, we highlight our current understanding of the regulatory mechanisms of the ghrelin system in energy metabolism and cellular homeostasis and its clinical trials. Future studies of ghrelin will further elucidate how the stomach regulates systemic homeostasis.
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Affiliation(s)
- Shigehisa Yanagi
- Divisions of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan
| | - Takahiro Sato
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume 839-0864, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Masamitsu Nakazato
- Divisions of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan.
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94
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Orellana ER, Jamis C, Horvath N, Hajnal A. Effect of vertical sleeve gastrectomy on alcohol consumption and preferences in dietary obese rats and mice: A plausible role for altered ghrelin signaling. Brain Res Bull 2018; 138:26-36. [PMID: 28802901 PMCID: PMC6537102 DOI: 10.1016/j.brainresbull.2017.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/05/2017] [Accepted: 08/07/2017] [Indexed: 12/13/2022]
Abstract
Vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB) are the most common surgical options for the treatment of obesity and metabolic disorder. Whereas RYGB may result in greater and more durable weight loss, recent clinical and pre-clinical studies in rats have raised concerns that RYGB surgery may increase risk for alcohol use disorder (AUD). In contrast, recent clinical reports suggest a lesser risk for AUD following VSG, although no preclinical studies have been done to confirm that. Therefore, the present study sought to determine the effects of VSG on ethanol intake and preferences in rodent models using protocols similar to those previously used in animal studies for RYGB. Male Sprague Dawley rats and male C57B6 mice were made obese on a high fat diet (60%kcal from fat) and received VSG or no surgery (controls). All animals then were given access to increasing concentrations of ethanol (2%, 4%, 6%, and 8%), presented for few days each. Compared to controls, VSG rats consumed significantly less of 2, 6 and 8% ethanol and showed significantly reduced preferences to 6 and 8% ethanol over water. VSG mice also displayed reduced intake and preference for 6 and 8% ethanol solutions. After a two-week period of forced abstinence, 8% ethanol was reintroduced and the VSG rats and mice continued to exhibit reduced consumption and less preference for ethanol. Regarding the underlying mechanism, we hypothesized that the removal of the ghrelin producing part of the stomach in the VSG surgery is a possible contributor to the observed reduced ethanol preference. To test for functional changes at the ghrelin receptors, the VSG and control rats were given IP injections of acyl-ghrelin (2.5nmol and 5nmol) prior to ethanol access. Neither concentration of ghrelin resulted in a significant increase in 8% ethanol consumption of VSG or control subjects. Next, the rats were given IP injections of the ghrelin receptor antagonist, JMV (2.5mg/kg body weight). This dose induced a significant reduction in 8% ethanol consumption in the VSG group, but no effect on ethanol intake in the controls. While ghrelin injection was uninformative, increased sensitivity to subthreshold doses of the ghrelin receptor antagonist may indicate reduced ghrelin signaling following VSG. Overall, these findings suggest that bariatric patients with increased susceptibility to AUD may benefit from receiving VSG instead of RYGB surgery, and that changes in ghrelin signaling, at least in part, may play a role in the differential AUD risks between the two most commonly performed bariatric surgical procedures.
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Affiliation(s)
- Elise R Orellana
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033, USA
| | - Catherine Jamis
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033, USA
| | - Nelli Horvath
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033, USA
| | - Andras Hajnal
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033, USA.
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95
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Beeler JA, Mourra D. To Do or Not to Do: Dopamine, Affordability and the Economics of Opportunity. Front Integr Neurosci 2018; 12:6. [PMID: 29487508 PMCID: PMC5816947 DOI: 10.3389/fnint.2018.00006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/26/2018] [Indexed: 12/21/2022] Open
Abstract
Five years ago, we introduced the thrift hypothesis of dopamine (DA), suggesting that the primary role of DA in adaptive behavior is regulating behavioral energy expenditure to match the prevailing economic conditions of the environment. Here we elaborate that hypothesis with several new ideas. First, we introduce the concept of affordability, suggesting that costs must necessarily be evaluated with respect to the availability of resources to the organism, which computes a value not only for the potential reward opportunity, but also the value of resources expended. Placing both costs and benefits within the context of the larger economy in which the animal is functioning requires consideration of the different timescales against which to compute resource availability, or average reward rate. Appropriate windows of computation for tracking resources requires corresponding neural substrates that operate on these different timescales. In discussing temporal patterns of DA signaling, we focus on a neglected form of DA plasticity and adaptation, changes in the physical substrate of the DA system itself, such as up- and down-regulation of receptors or release probability. We argue that changes in the DA substrate itself fundamentally alter its computational function, which we propose mediates adaptations to longer temporal horizons and economic conditions. In developing our hypothesis, we focus on DA D2 receptors (D2R), arguing that D2R implements a form of “cost control” in response to the environmental economy, serving as the “brain’s comptroller”. We propose that the balance between the direct and indirect pathway, regulated by relative expression of D1 and D2 DA receptors, implements affordability. Finally, as we review data, we discuss limitations in current approaches that impede fully investigating the proposed hypothesis and highlight alternative, more semi-naturalistic strategies more conducive to neuroeconomic investigations on the role of DA in adaptive behavior.
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Affiliation(s)
- Jeff A Beeler
- Department of Psychology, Queens College, City University of New York, New York, NY, United States.,CUNY Neuroscience Consortium, The Graduate Center, City University of New York, New York, NY, United States
| | - Devry Mourra
- Department of Psychology, Queens College, City University of New York, New York, NY, United States.,CUNY Neuroscience Consortium, The Graduate Center, City University of New York, New York, NY, United States
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96
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Ralevski E, Horvath TL, Shanabrough M, Hayden R, Newcomb J, Petrakis I. Ghrelin is Supressed by Intravenous Alcohol and is Related to Stimulant and Sedative Effects of Alcohol. Alcohol Alcohol 2018; 52:431-438. [PMID: 28481974 DOI: 10.1093/alcalc/agx022] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 03/10/2017] [Indexed: 12/30/2022] Open
Abstract
Aims Evidence indicates that feeding-related peptides, such as ghrelin, have a role in the rewarding properties of addictive substances like alcohol. Oral alcohol administration significantly suppresses ghrelin. This study was designed to evaluate the effects of two doses of alcohol on ghrelin and examine if ghrelin levels predict the subjective effects of alcohol. Methods Healthy social drinkers (N = 20) participated in three, randomly assigned, and counterbalanced laboratory sessions. During each session they received a continuous IV infusion of either placebo (saline), low dose (40 mg%) or high dose (100 mg%) of alcohol. Participants were given a standardized, light breakfast 90 min before the start of the infusion. Ghrelin levels [acyl ghrelin (AG) and total ghrelin (TG)] were collected at four time points before, during and after the infusion. Subjective effects of alcohol, using the BAES, were evaluated before, during and after alcohol infusion. Results IV alcohol significantly reduced AG but not TG levels with no difference between the two doses of alcohol. The percent change (%∆) in AG suppression was substantial in both high dose (43.4%∆), and low dose (39.5%∆) of alcohol. Also, fasting AG and TG levels were significant predictors of alcohol stimulant and sedative effects. Higher fasting ghrelin levels were associated with longer and more intense subjective effects. Conclusions The results provide evidence that IV alcohol suppresses ghrelin levels similarly to oral alcohol. This study is the first to show that ghrelin predicts subjective effects of alcohol, suggesting that ghrelin may have a role in the rewarding mechanisms for alcohol. Short summary Intravenous alcohol infusion (low dose and high dose of alcohol) when compared to placebo (saline) significantly suppresses ghrelin in healthy social drinkers. Fasting ghrelin levels also predict subjective behavioral effects of alcohol. Those with higher fasting ghrelin levels tend to experience alcohol effects longer and more intensely.
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Affiliation(s)
- Elizabeth Ralevski
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT, USA.,Department of Veterans Affairs, VA Connecticut Healthcare System, 950 Campbell Ave, West Haven, CT, USA.,Mental Illness Research and Clinical Center, VA Connecticut Healthcare System, 950 Campbell Ave, West Haven, CT, USA
| | - Tamas L Horvath
- Program of Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., Ste 330 BML, New Haven, CT, USA.,Department of Obstetrics/Gynecology and Reproductive Sciences, Yale University School of Medicine, 310 Cedar St., Ste 330 BML, New Haven, CT, USA
| | - Marya Shanabrough
- Program of Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., Ste 330 BML, New Haven, CT, USA
| | - Ryan Hayden
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT, USA
| | - Jenelle Newcomb
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT, USA.,Department of Veterans Affairs, VA Connecticut Healthcare System, 950 Campbell Ave, West Haven, CT, USA.,Mental Illness Research and Clinical Center, VA Connecticut Healthcare System, 950 Campbell Ave, West Haven, CT, USA
| | - Ismene Petrakis
- Department of Psychiatry, Yale University School of Medicine, 333 Cedar St., New Haven, CT, USA.,Department of Veterans Affairs, VA Connecticut Healthcare System, 950 Campbell Ave, West Haven, CT, USA.,Mental Illness Research and Clinical Center, VA Connecticut Healthcare System, 950 Campbell Ave, West Haven, CT, USA
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97
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Liu CM, Kanoski SE. Homeostatic and non-homeostatic controls of feeding behavior: Distinct vs. common neural systems. Physiol Behav 2018; 193:223-231. [PMID: 29421588 DOI: 10.1016/j.physbeh.2018.02.011] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/02/2018] [Accepted: 02/03/2018] [Indexed: 02/06/2023]
Abstract
Understanding the neurobiological controls of feeding behavior is critical in light of the growing obesity pandemic, a phenomenon largely based on excessive caloric consumption. Feeding behavior and its underlying biological substrates are frequently divided in the literature into two separate categories: [1] homeostatic processes involving energy intake based on caloric and other metabolic deficits, and [2] non-homeostatic processes that involve feeding driven by environmental and cognitive factors. The present review summarizes both historic and recent research examining the homeostatic regulation of feeding with specific emphasis on hypothalamic and hindbrain circuitry that monitor and regulate various metabolic signals. Regarding non-homeostatic controls, we highlight higher-order brain structures that integrate feeding-relevant external, interoceptive, and cognitive factors, including sensory cortical processing, learned associations in the hippocampus, and reward-based processing in the nucleus accumbens and interconnected mesolimbic circuitry. Finally, the current review focuses on recent evidence that challenges the traditional view that distinct neural systems regulate homeostatic vs. non-homeostatic controls of feeding behavior. Specifically, we highlight several feeding-related endocrine systems that act on both lower- and higher-order substrates, present evidence for the modulation of learned and cognitive feeding-relevant behaviors by lower-order brain regions, and highlight data showing that apparent homeostatic-based feeding behavior is modulated by higher-order brain regions. Our concluding perspective is that the classic dissociation between homeostatic and non-homeostatic constructs in relation to feeding behavior is limited with regards to understanding the complex integrated neurobiological systems that control energy balance.
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Affiliation(s)
- Clarissa M Liu
- University of Southern California, Neuroscience Graduate Program, Los Angeles, CA, United States; University of Southern California, Department of Biological Sciences, Human and Evolutionary Biology Section, Los Angeles, CA, United States
| | - Scott E Kanoski
- University of Southern California, Neuroscience Graduate Program, Los Angeles, CA, United States; University of Southern California, Department of Biological Sciences, Human and Evolutionary Biology Section, Los Angeles, CA, United States.
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98
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Satta V, Scherma M, Piscitelli F, Usai P, Castelli MP, Bisogno T, Fratta W, Fadda P. Limited Access to a High Fat Diet Alters Endocannabinoid Tone in Female Rats. Front Neurosci 2018; 12:40. [PMID: 29456490 PMCID: PMC5801427 DOI: 10.3389/fnins.2018.00040] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/17/2018] [Indexed: 12/25/2022] Open
Abstract
Emerging evidence suggest an impaired endocannabinoid activity in the pathophysiology of binge eating disorder (BED). Herein, we investigated whether endocannabinoid tone could be modified as a consequence of dietary-induced binge eating in female rats. For this purpose, brain levels of the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), as well as two endocannabinoid-like lipids, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), were assessed in different brain areas involved in the hedonic feeding (i.e., prefrontal cortex, nucleus accumbens, amygdala, hippocampus, and hypothalamus). The brain density of cannabinoid type-1 receptors (CB1) was also evaluated. Furthermore, we determined plasma levels of leptin, ghrelin, and corticosterone hormones, which are well-known to control the levels of endocannabioids and/or CB1 receptors in the brain. To induce binge eating behavior, rats were subject to an intermittent and limited access to a high fat diet (HFD) (margarine). Three experimental groups were used, all with ad libitum access to chow: control (CTRL), with no access to margarine; low restriction (LR), with 2 h margarine access 7 days/week; high restriction (HR), with 2 h margarine access 3 days/week. Bingeing was established when margarine intake in the HR group exceeded that of the LR group. Our results show that, compared to CTRL, AEA significantly decreased in the caudate putamen, amygdala, and hippocampus of HR group. In contrast, 2-AG significantly increased in the hippocampus while OEA decreased in the hypothalamus. Similar to the HR group, AEA and OEA decreased respectively in the amygdala and hypothalamus and 2-AG increased in the hippocampus of LR group. Moreover, LR group also had AEA decreased in the prefrontal cortex and increased in the nucleus accumbens. In both groups we found the same reduction of CB1 receptor density in the prefrontal cortex compared to CTRL. Also, LR and HR groups showed alterations in both ghrelin and corticosterone levels, while leptin remained unaltered. In conclusion, our findings show a modified endocannabinoid tone due to margarine exposure, in several brain areas that are known to influence the hedonic aspect of food. Even if not uniquely specific to binge eating, margarine-induced changes in endocannabinoid tone could contributes to the development and maintenance of this behavior.
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Affiliation(s)
- Valentina Satta
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Maria Scherma
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Fabiana Piscitelli
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy
| | - Paolo Usai
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - M Paola Castelli
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Tiziana Bisogno
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy.,Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Walter Fratta
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Paola Fadda
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
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99
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Poher AL, Tschöp MH, Müller TD. Ghrelin regulation of glucose metabolism. Peptides 2018; 100:236-242. [PMID: 29412824 PMCID: PMC5805851 DOI: 10.1016/j.peptides.2017.12.015] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/15/2017] [Accepted: 12/16/2017] [Indexed: 02/07/2023]
Abstract
The a 28-amino acid peptide ghrelin was discovered in 1999 as a growth hormone (GH) releasing peptide. Soon after its discovery, ghrelin was found to increase body weight and adiposity by acting on the hypothalamic melanocortinergic system. Subsequently, ghrelin was found to exert a series of metabolic effects, overall testifying ghrelin a pleiotropic nature of broad pharmacological interest. Ghrelin acts through the growth hormone secretagogue-receptor (GHS-R), a seven transmembrane G protein-coupled receptor with high expression in the anterior pituitary, pancreatic islets, thyroid gland, heart and various regions of the brain. Among ghrelins numerous metabolic effects are the most prominent the stimulation of appetite via activation of orexigenic hypothalamic neurocircuits and the food-intake independent stimulation of lipogenesis, which both together lead to an increase in body weight and adiposity. Ghrelin effects beyond the regulation of appetite and GH secretion include the regulation of gut motility, sleep-wake rhythm, taste sensation, reward seeking behaviour, and the regulation of glucose metabolism. The latter received recently increasing recognition because pharmacological inhibition of ghrelin signaling might be of therapeutic value to improve insuin resistance and type 2 diabetes. In this review we highlight the multifaceted nature of ghrelin and summarize its glucoregulatory action and discuss the pharmacological value of ghrelin pathway inhibition for the treatment of glucose intolerance and type 2 diabetes.
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Affiliation(s)
- Anne-Laure Poher
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), 85764, Neuherberg, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), 85764, Neuherberg, Germany; Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 80333, Munich, Germany
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), 85764, Neuherberg, Germany.
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100
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Mani BK, Castorena CM, Osborne-Lawrence S, Vijayaraghavan P, Metzger NP, Elmquist JK, Zigman JM. Ghrelin mediates exercise endurance and the feeding response post-exercise. Mol Metab 2018; 9:114-130. [PMID: 29396372 PMCID: PMC5870098 DOI: 10.1016/j.molmet.2018.01.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/09/2018] [Accepted: 01/12/2018] [Indexed: 12/19/2022] Open
Abstract
Objective Exercise training has several well-established health benefits, including many related to body weight, appetite control, and blood glucose homeostasis. However, the molecular mechanisms and, in particular, the hormonal systems that mediate and integrate these beneficial effects are poorly understood. In the current study, we aimed to investigate the role of the hormone ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR; ghrelin receptor), in mediating the effects of exercise on food intake and blood glucose following exercise as well as in regulating exercise endurance capacity. Methods We used two mouse models of treadmill running to characterize the changes in plasma ghrelin with exercise. We also assessed the role of the ghrelin system to influence food intake and blood glucose after exercise, exercise endurance, and parameters potentially linked to responses to exercise. Mice lacking GHSRs (GHSR-null mice) and wild-type littermates were studied. Results An acute bout of exercise transiently elevated plasma acyl-ghrelin. Without the action of this increased ghrelin on GHSRs (as in GHSR-null mice), high intensity interval exercise markedly reduced food intake compared to control mice. The effect of exercise to acutely raise blood glucose remained unmodified in GHSR-null mice. Exercise-induced increases in plasma ghrelin positively correlated with endurance capacity, and time to exhaustion was reduced in GHSR-null mice as compared to wild-type littermates. In an effort to mechanistically explain their reduced exercise endurance, exercised GHSR-null mice exhibited an abrogated sympathoadrenal response, lower overall insulin-like growth factor-1 levels, and altered glycogen utilization. Conclusions Exercise transiently increases plasma ghrelin. GHSR-null mice exhibit decreased food intake following high intensity interval exercise and decreased endurance when submitted to an exercise endurance protocol. These data suggest that an intact ghrelin system limits the capacity of exercise to restrict food intake following exercise, although it enhances exercise endurance. High intensity exercise transiently increases plasma ghrelin. Without ghrelin action on its receptors (growth hormone secretagogue receptors), exercise markedly reduces food intake. An intact ghrelin system enhances exercise endurance.
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Affiliation(s)
- Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carlos M Castorena
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sherri Osborne-Lawrence
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prasanna Vijayaraghavan
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nathan P Metzger
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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