1
|
Edvardsson CE, Vestlund J, Ericson M, Jerlhag E. The GLP-1 receptor agonist exendin-4 reduces taurine and glycine in nucleus accumbens of male rats, an effect tentatively involving the nucleus tractus solitarius. Front Pharmacol 2024; 15:1439203. [PMID: 39221138 PMCID: PMC11362053 DOI: 10.3389/fphar.2024.1439203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Accepted: 08/07/2024] [Indexed: 09/04/2024] Open
Abstract
The physiological effects of glucagon-like peptide-1 (GLP-1) are mainly centered on its ability to decrease blood glucose levels and facilitate satiety. Additional physiological functions have been identified by means of GLP-1 agonists such as exenatide (exendin-4; Ex4). In particular, Ex4 reduces the intake of natural and artificial rewards, effects that to some extent involve activation of GLP-1 receptors in the nucleus tractus solitarius (NTS). Although Ex4 acts in the brain, the neurochemical mechanisms underlying this activation are not fully elucidated. Investigating Ex4-induced neurochemical alterations in the nucleus accumbens (NAc) would be valuable for understanding its impact on reward-related behaviors. The aim of the present exploratory in vivo microdialysis study was therefore to study how Ex4, administered either systemically or locally into the NTS, influences classical neurotransmitters like dopamine, serotonin, noradrenaline, glutamate and GABA as well as additional players such as glycine, taurine and serine in NAc of male rats. We showed that Ex4 reduced extracellular levels of serine, taurine and glycine, where the latter two declines appear to involve activation of GLP-1R in the NTS. Besides, after systemic Ex4 injection the metabolites DOPAC, HVA, and 5HIAA are elevated. Where the increase in metabolites related to dopamine, but not serotonin, involves GLP-1 receptors in other areas than the NTS. Although the descriptive nature of the present data does not provide causality, it may however serve as an indication of mechanisms underlying how Ex4 may modulate reward-related behaviors.
Collapse
Affiliation(s)
- Christian E. Edvardsson
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Jesper Vestlund
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Mia Ericson
- 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
| |
Collapse
|
2
|
Balantekin KN, Kretz MJ, Mietlicki-Baase EG. The emerging role of glucagon-like peptide 1 in binge eating. J Endocrinol 2024; 262:e230405. [PMID: 38642585 PMCID: PMC11156433 DOI: 10.1530/joe-23-0405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/16/2024] [Indexed: 04/22/2024]
Abstract
Binge eating is a central component of two clinical eating disorders: binge eating disorder and bulimia nervosa. However, the large treatment gap highlights the need to identify other strategies to decrease binge eating. Novel pharmacotherapies may be one such approach. Glucagon-like peptide-1 (GLP-1) is an intestinal and brain-derived neuroendocrine signal with a critical role in promoting glycemic control through its incretin effect. Additionally, the energy balance effects of GLP-1 are well-established; activation of the GLP-1 receptor (GLP-1R) reduces food intake and body weight. Aligned with these beneficial metabolic effects, there are GLP-1R agonists that are currently used for the treatment of diabetes and obesity. A growing body of literature suggests that GLP-1 may also play an important role in binge eating. Dysregulation of the endogenous GLP-1 system is associated with binge eating in non-human animal models, and GLP-1R agonists may be a promising approach to suppress the overconsumption that occurs during binge eating. Here, we briefly discuss the role of GLP-1 in normal energy intake and reward and then review the emerging evidence suggesting that disruptions to GLP-1 signaling are associated with binge eating. We also consider the potential utility of GLP-1-based pharmacotherapies for reducing binge eating behavior.
Collapse
Affiliation(s)
- Katherine N. Balantekin
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY 14214 USA
- Center for Ingestive Behavior Research, University at Buffalo, Buffalo, NY 14260 USA
| | - Martin J. Kretz
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY 14214 USA
| | - Elizabeth G. Mietlicki-Baase
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY 14214 USA
- Center for Ingestive Behavior Research, University at Buffalo, Buffalo, NY 14260 USA
| |
Collapse
|
3
|
Łupina M, Wąsik A, Baranowska-Bosiacka I, Tarnowski M, Słowik T, Listos P, Kotlińska J, Kosik-Bogacka D, Gutowska I, Listos J. Acute and Chronic Exposure to Linagliptin, a Selective Inhibitor of Dipeptidyl Peptidase-4 (DPP-4), Has an Effect on Dopamine, Serotonin and Noradrenaline Level in the Striatum and Hippocampus of Rats. Int J Mol Sci 2024; 25:3008. [PMID: 38474255 DOI: 10.3390/ijms25053008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
Linagliptin is a selective dipeptidyl peptidase-4 (DPP-4) inhibitor that indirectly elevates the glucagon-like peptide-1 (GLP-1) level. The aim of the present study was to check whether linagliptin has an influence on neurotransmission in rat brain. Rats were acutely and chronically exposed to linagliptin (10 and 20 mg/kg, intraperitoneally (i.p.)). Twenty-four hours later, the striatum and hippocampus were selected for further studies. In neurochemical experiments, using high-performance liquid chromatography with electrochemical detection (HPLC-ED), the concentrations of three major neurotransmitters-dopamine, serotonin and noradrenaline-and their metabolites were measured. The analysis of mRNA expression of dopamine (D1 and D2), serotonin (5-HT-1 and 5-HT-2) and noradrenaline (α1 and α2a) receptors was also investigated using real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) in the same brain areas. Linagliptin has the ability to influence the dopaminergic system. In the striatum, the elevation of dopamine and its metabolites was observed after repeated administration of that linagliptin, and in the hippocampus, a reduction in dopamine metabolism was demonstrated. Acute linagliptin exposure increases the serotonin level in both areas, while after chronic linagliptin administration a tendency for the mRNA expression of serotoninergic receptors (5-HT1A and 5-HT2A) to increase was observed. A single instance of exposure to linagliptin significantly modified the noradrenaline level in the striatum and intensified noradrenaline turnover in the hippocampus. The recognition of the interactions in the brain between DPP-4 inhibitors and neurotransmitters and/or receptors is a crucial step for finding novel discoveries in the pharmacology of DPP-4 inhibitors and raises hope for further applications of DPP-4 inhibitors in clinical practices.
Collapse
Affiliation(s)
- Małgorzata Łupina
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego 8b St., 20-090 Lublin, Poland
| | - Agnieszka Wąsik
- Department of Neurochemistry, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72 Av., 70-111 Szczecin, Poland
| | - Maciej Tarnowski
- Department of Physiology in Health Sciences, Pomeranian Medical University, Żołnierska 54, 70-210 Szczecin, Poland
| | - Tymoteusz Słowik
- Experimental Medicine Center, Medical University of Lublin, Jaczewskiego 8d St., 20-090 Lublin, Poland
| | - Piotr Listos
- Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Life Sciences, Głęboka 30, 20-612 Lublin, Poland
| | - Jolanta Kotlińska
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St., 20-093 Lublin, Poland
| | - Danuta Kosik-Bogacka
- Independent Laboratory of Pharmaceutical Botany, Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University, Broniewskiego 24, 71-460 Szczecin, Poland
| | - Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St., 20-093 Lublin, Poland
| |
Collapse
|
4
|
López-Ojeda W, Hurley RA. Glucagon-Like Peptide 1: An Introduction and Possible Implications for Neuropsychiatry. J Neuropsychiatry Clin Neurosci 2024; 36:A4-86. [PMID: 38616646 DOI: 10.1176/appi.neuropsych.20230226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Affiliation(s)
- Wilfredo López-Ojeda
- Veterans Affairs Mid-Atlantic Mental Illness Research, Education and Clinical Center (MIRECC) and Research and Academic Affairs Service Line, W.G. Hefner Veterans Affairs Medical Center, Salisbury, N.C. (López-Ojeda, Hurley); Department of Psychiatry and Behavioral Medicine (López-Ojeda, Hurley) and Department of Radiology (Hurley), Wake Forest University School of Medicine, Winston-Salem, N.C.; Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston (Hurley)
| | - Robin A Hurley
- Veterans Affairs Mid-Atlantic Mental Illness Research, Education and Clinical Center (MIRECC) and Research and Academic Affairs Service Line, W.G. Hefner Veterans Affairs Medical Center, Salisbury, N.C. (López-Ojeda, Hurley); Department of Psychiatry and Behavioral Medicine (López-Ojeda, Hurley) and Department of Radiology (Hurley), Wake Forest University School of Medicine, Winston-Salem, N.C.; Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston (Hurley)
| |
Collapse
|
5
|
Fortin SM, Chen JC, Petticord MC, Ragozzino FJ, Peters JH, Hayes MR. The locus coeruleus contributes to the anorectic, nausea, and autonomic physiological effects of glucagon-like peptide-1. SCIENCE ADVANCES 2023; 9:eadh0980. [PMID: 37729419 PMCID: PMC10511187 DOI: 10.1126/sciadv.adh0980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023]
Abstract
Increasing the therapeutic potential and reducing the side effects of U.S. Food and Drug Administration-approved glucagon-like peptide-1 receptor (GLP-1R) agonists used to treat obesity require complete characterization of the central mechanisms that mediate both the food intake-suppressive and illness-like effects of GLP-1R signaling. Our studies, in the rat, demonstrate that GLP-1Rs in the locus coeruleus (LC) are pharmacologically and physiologically relevant for food intake control. Furthermore, agonism of LC GLP-1Rs induces illness-like behaviors, and antagonism of LC GLP-1Rs can attenuate GLP-1R-mediated nausea. Electrophysiological and behavioral pharmacology data support a role for LC GLP-1Rs expressed on presynaptic glutamatergic terminals in the control of feeding and malaise. Collectively, our work establishes the LC as a site of action for GLP-1 signaling and extends our understanding of the GLP-1 signaling mechanism necessary for the development of improved obesity pharmacotherapies.
Collapse
Affiliation(s)
- Samantha M. Fortin
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jack C. Chen
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marisa C. Petticord
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Forrest J. Ragozzino
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - James H. Peters
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Matthew R. Hayes
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
6
|
Sheth S, Patel A, Foreman M, Mumtaz M, Reddy A, Sharaf R, Sheth S, Lucke-Wold B. The protective role of GLP-1 in neuro-ophthalmology. EXPLORATION OF DRUG SCIENCE 2023; 1:221-238. [PMID: 37711214 PMCID: PMC10501042 DOI: 10.37349/eds.2023.00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/22/2023] [Indexed: 09/16/2023]
Abstract
Despite recent advancements in the field of neuro-ophthalmology, the rising rates of neurological and ophthalmological conditions, mismatches between supply and demand of clinicians, and an aging population underscore the urgent need to explore new therapeutic approaches within the field. Glucagon-like peptide 1 receptor agonists (GLP-1RAs), traditionally used in the treatment of type 2 diabetes, are becoming increasingly appreciated for their diverse applications. Recently, GLP-1RAs have been approved for the treatment of obesity and recognized for their cardioprotective effects. Emerging evidence indicates some GLP-1RAs can cross the blood-brain barrier and may have neuroprotective effects. Therefore, this article aims to review the literature on the neurologic and neuro-ophthalmic role of glucagon-like peptide 1 (GLP-1). This article describes GLP-1 peptide characteristics and the mechanisms mediating its known role in increasing insulin, decreasing glucagon, delaying gastric emptying, and promoting satiety. This article identifies the sources and targets of GLP-1 in the brain and review the mechanisms which mediate its neuroprotective effects, as well as implications for Alzheimer's disease (AD) and Parkinson's disease (PD). Furthermore, the preclinical works which unravel the effects of GLP-1 in ocular dynamics and the preclinical literature regarding GLP-1RA use in the management of several neuro-ophthalmic conditions, including diabetic retinopathy (DR), glaucoma, and idiopathic intracranial hypertension (IIH) are discussed.
Collapse
Affiliation(s)
- Sohum Sheth
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Aashay Patel
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Marco Foreman
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Mohammed Mumtaz
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Akshay Reddy
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Ramy Sharaf
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Siddharth Sheth
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| |
Collapse
|
7
|
Ying Z, van Eenige R, Ge X, van Marwijk C, Lambooij JM, Guigas B, Giera M, de Boer JF, Coskun T, Qu H, Wang Y, Boon MR, Rensen PCN, Kooijman S. Combined GIP receptor and GLP1 receptor agonism attenuates NAFLD in male APOE∗3-Leiden.CETP mice. EBioMedicine 2023; 93:104684. [PMID: 37379656 DOI: 10.1016/j.ebiom.2023.104684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Combined glucose-dependent insulinotropic polypeptide receptor (GIPR) and glucagon-like peptide-1 receptor (GLP1R) agonism is superior to single GLP1R agonism with respect to glycemic control and weight loss in obese patients with or without type 2 diabetes. As insulin resistance and obesity are strong risk factors for nonalcoholic fatty liver disease (NAFLD), in the current study we investigated the effects of combined GIPR/GLP1R agonism on NAFLD development. METHODS Male APOE∗3-Leiden.CETP mice, a humanized model for diabetic dyslipidemia and NAFLD when fed a high-fat high-cholesterol diet, received subcutaneous injections with either vehicle, a GIPR agonist, a GLP1R agonist, or both agonists combined every other day. FINDINGS GIPR and GLP1R agonism reduced body weight and additively lowered fasting plasma levels of glucose, triglycerides and total cholesterol. Strikingly, we report an additive reduction in hepatic steatosis as evidenced by lower hepatic lipid content and NAFLD scores. Underlying the lipid-lowering effects were a reduced food intake and intestinal lipid absorption and an increased uptake of glucose and triglyceride-derived fatty acids by energy-combusting brown adipose tissue. Combined GIPR/GLP1R agonism also attenuated hepatic inflammation as evidenced by a decreased number of monocyte-derived Kupffer cells and a reduced expression of inflammatory markers. Together, the reduced hepatic steatosis and inflammation coincided with lowered markers of liver injury. INTERPRETATION We interpretate that GIPR and GLP1R agonism additively attenuate hepatic steatosis, lower hepatic inflammation, ameliorate liver injury, together preventing NAFLD development in humanized APOE∗3-Leiden.CETP mice. We anticipate that combined GIPR/GLP1R agonism is a promising strategy to attenuate NAFLD progression in humans. FUNDING This work was supported by a grant from the Netherlands CardioVascular Research Initiative: the Dutch Heart Foundation, Dutch Federation of University Medical Centers, the Netherlands Organization for Health Research and Development, and the Royal Netherlands Academy of Sciences [CVON-GENIUS-II] to P.C.N.R., a Lilly Research Award Program [LRAP] Award to P.C.N.R. and S.K., a Dutch Heart Foundation [2017T016] grant to S.K., and an NWO-VENI grant [09150161910073] to M.R.B.; J.F.D.B. is supported by the Nutrition and Health initiative of the University of Groningen; Z.Y. is supported by a full-time PhD scholarship from the China Scholarship Council (201806850094 to Z.Y.).
Collapse
Affiliation(s)
- Zhixiong Ying
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Robin van Eenige
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Xiaoke Ge
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Christy van Marwijk
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Joost M Lambooij
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands; Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Bruno Guigas
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Martin Giera
- The Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, the Netherlands
| | - Jan Freark de Boer
- Departments of Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Tamer Coskun
- Department of Diabetes/Endocrine, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN, United States
| | - Hongchang Qu
- Department of Diabetes/Endocrine, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN, United States
| | - Yanan Wang
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Med-X Institute, Center for Immunological and Metabolic Diseases and Department of Endocrinology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, China
| | - Mariëtte R Boon
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Patrick C N Rensen
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - Sander Kooijman
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
| |
Collapse
|
8
|
Chuong V, Farokhnia M, Khom S, Pince CL, Elvig SK, Vlkolinsky R, Marchette RC, Koob GF, Roberto M, Vendruscolo LF, Leggio L. The glucagon-like peptide-1 (GLP-1) analogue semaglutide reduces alcohol drinking and modulates central GABA neurotransmission. JCI Insight 2023; 8:e170671. [PMID: 37192005 PMCID: PMC10371247 DOI: 10.1172/jci.insight.170671] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/10/2023] [Indexed: 05/17/2023] Open
Abstract
Growing evidence indicates that the glucagon-like peptide-1 (GLP-1) system is involved in the neurobiology of addictive behaviors, and GLP-1 analogues may be used for the treatment of alcohol use disorder (AUD). Here, we examined the effects of semaglutide, a long-acting GLP-1 analogue, on biobehavioral correlates of alcohol use in rodents. A drinking-in-the-dark procedure was used to test the effects of semaglutide on binge-like drinking in male and female mice. We also tested the effects of semaglutide on binge-like and dependence-induced alcohol drinking in male and female rats, as well as acute effects of semaglutide on spontaneous inhibitory postsynaptic currents (sIPSCs) from central amygdala (CeA) and infralimbic cortex (ILC) neurons. Semaglutide dose-dependently reduced binge-like alcohol drinking in mice; a similar effect was observed on the intake of other caloric/noncaloric solutions. Semaglutide also reduced binge-like and dependence-induced alcohol drinking in rats. Semaglutide increased sIPSC frequency in CeA and ILC neurons from alcohol-naive rats, suggesting enhanced GABA release, but had no overall effect on GABA transmission in alcohol-dependent rats. In conclusion, the GLP-1 analogue semaglutide decreased alcohol intake across different drinking models and species and modulated central GABA neurotransmission, providing support for clinical testing of semaglutide as a potentially novel pharmacotherapy for AUD.
Collapse
Affiliation(s)
- Vicky Chuong
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program (NIDA IRP) and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research (NIAAA DICBR), NIH, Baltimore and Bethesda, Maryland, USA
- Neurobiology of Addiction Section, NIDA IRP, NIH, Baltimore, Maryland, USA
| | - Mehdi Farokhnia
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program (NIDA IRP) and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research (NIAAA DICBR), NIH, Baltimore and Bethesda, Maryland, USA
| | - Sophia Khom
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Claire L. Pince
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program (NIDA IRP) and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research (NIAAA DICBR), NIH, Baltimore and Bethesda, Maryland, USA
- Neurobiology of Addiction Section, NIDA IRP, NIH, Baltimore, Maryland, USA
| | - Sophie K. Elvig
- Neurobiology of Addiction Section, NIDA IRP, NIH, Baltimore, Maryland, USA
| | - Roman Vlkolinsky
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | | | - George F. Koob
- Neurobiology of Addiction Section, NIDA IRP, NIH, Baltimore, Maryland, USA
| | - Marisa Roberto
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Leandro F. Vendruscolo
- Stress and Addiction Neuroscience Unit, NIDA IRP and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, Maryland, USA
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program (NIDA IRP) and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research (NIAAA DICBR), NIH, Baltimore and Bethesda, Maryland, USA
| |
Collapse
|
9
|
Jin R, Sun S, Hu Y, Zhang H, Sun X. Neuropeptides Modulate Feeding via the Dopamine Reward Pathway. Neurochem Res 2023:10.1007/s11064-023-03954-4. [PMID: 37233918 DOI: 10.1007/s11064-023-03954-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/13/2023] [Accepted: 05/16/2023] [Indexed: 05/27/2023]
Abstract
Dopamine (DA) is a catecholamine neurotransmitter widely distributed in the central nervous system. It participates in various physiological functions, such as feeding, anxiety, fear, sleeping and arousal. The regulation of feeding is exceptionally complex, involving energy homeostasis and reward motivation. The reward system comprises the ventral tegmental area (VTA), nucleus accumbens (NAc), hypothalamus, and limbic system. This paper illustrates the detailed mechanisms of eight typical orexigenic and anorexic neuropeptides that regulate food intake through the reward system. According to recent literature, neuropeptides released from the hypothalamus and other brain regions regulate reward feeding predominantly through dopaminergic neurons projecting from the VTA to the NAc. In addition, their effect on the dopaminergic system is mediated by the prefrontal cortex, paraventricular thalamus, laterodorsal tegmental area, amygdala, and complex neural circuits. Research on neuropeptides involved in reward feeding can help identify more targets to treat diseases with metabolic disorders, such as obesity.
Collapse
Affiliation(s)
- Ruijie Jin
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Shanbin Sun
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Yang Hu
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Hongfei Zhang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Xiangrong Sun
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China.
| |
Collapse
|
10
|
Roh E, Choi KM. Hormonal Gut-Brain Signaling for the Treatment of Obesity. Int J Mol Sci 2023; 24:ijms24043384. [PMID: 36834794 PMCID: PMC9959457 DOI: 10.3390/ijms24043384] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
The brain, particularly the hypothalamus and brainstem, monitors and integrates circulating metabolic signals, including gut hormones. Gut-brain communication is also mediated by the vagus nerve, which transmits various gut-derived signals. Recent advances in our understanding of molecular gut-brain communication promote the development of next-generation anti-obesity medications that can safely achieve substantial and lasting weight loss comparable to metabolic surgery. Herein, we comprehensively review the current knowledge about the central regulation of energy homeostasis, gut hormones involved in the regulation of food intake, and clinical data on how these hormones have been applied to the development of anti-obesity drugs. Insight into and understanding of the gut-brain axis may provide new therapeutic perspectives for the treatment of obesity and diabetes.
Collapse
Affiliation(s)
- Eun Roh
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang 14068, Republic of Korea
| | - Kyung Mook Choi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul 02841, Republic of Korea
- Correspondence: or
| |
Collapse
|
11
|
Morales I. Brain regulation of hunger and motivation: The case for integrating homeostatic and hedonic concepts and its implications for obesity and addiction. Appetite 2022; 177:106146. [PMID: 35753443 DOI: 10.1016/j.appet.2022.106146] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 11/19/2022]
Abstract
Obesity and other eating disorders are marked by dysregulations to brain metabolic, hedonic, motivational, and sensory systems that control food intake. Classic approaches in hunger research have distinguished between hedonic and homeostatic processes, and have mostly treated these systems as independent. Hindbrain structures and a complex network of interconnected hypothalamic nuclei control metabolic processes, energy expenditure, and food intake while mesocorticolimbic structures are though to control hedonic and motivational processes associated with food reward. However, it is becoming increasingly clear that hedonic and homeostatic brain systems do not function in isolation, but rather interact as part of a larger network that regulates food intake. Incentive theories of motivation provide a useful route to explore these interactions. Adapting incentive theories of motivation can enable researchers to better how motivational systems dysfunction during disease. Obesity and addiction are associated with profound alterations to both hedonic and homeostatic brain systems that result in maladaptive patterns of consumption. A subset of individuals with obesity may experience pathological cravings for food due to incentive sensitization of brain systems that generate excessive 'wanting' to eat. Further progress in understanding how the brain regulates hunger and appetite may depend on merging traditional hedonic and homeostatic concepts of food reward and motivation.
Collapse
Affiliation(s)
- Ileana Morales
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI, 48109-1043, USA.
| |
Collapse
|
12
|
Dunigan AI, Roseberry AG. Actions of feeding-related peptides on the mesolimbic dopamine system in regulation of natural and drug rewards. ADDICTION NEUROSCIENCE 2022; 2:100011. [PMID: 37220637 PMCID: PMC10201992 DOI: 10.1016/j.addicn.2022.100011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The mesolimbic dopamine system is the primary neural circuit mediating motivation, reinforcement, and reward-related behavior. The activity of this system and multiple behaviors controlled by it are affected by changes in feeding and body weight, such as fasting, food restriction, or the development of obesity. Multiple different peptides and hormones that have been implicated in the control of feeding and body weight interact with the mesolimbic dopamine system to regulate many different dopamine-dependent, reward-related behaviors. In this review, we summarize the effects of a selected set of feeding-related peptides and hormones acting within the ventral tegmental area and nucleus accumbens to alter feeding, as well as food, drug, and social reward.
Collapse
Affiliation(s)
- Anna I. Dunigan
- Department of Biology and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
| | - Aaron G. Roseberry
- Department of Biology and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
| |
Collapse
|
13
|
Ye Q, Nunez J, Zhang X. Oxytocin Receptor-Expressing Neurons in the Paraventricular Thalamus Regulate Feeding Motivation through Excitatory Projections to the Nucleus Accumbens Core. J Neurosci 2022; 42:3949-3964. [PMID: 35387870 PMCID: PMC9097779 DOI: 10.1523/jneurosci.2042-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 11/21/2022] Open
Abstract
Oxytocin receptors (OTR) have been found in the paraventricular thalamus (PVT) for the regulation of feeding and maternal behaviors. However, the functional projections of OTR-expressing PVT neurons remain largely unknown. Here, we used chemogenetic and optogenetic tools to test the role of OTR-expressing PVT neurons and their projections in the regulation of food intake in both male and female OTR-Cre mice. We found chemogenetic activation of OTR-expressing PVT neurons promoted food seeking under trials with a progressive ratio schedule of reinforcement. Using Feeding Experimentation Devices for real-time meal measurements, we found chemogenetic activation of OTR-expressing PVT neurons increased meal frequency but not cumulative food intake because of a compensatory decrease in meal sizes. In combination with anterograde neural tracing and slice patch-clamp recordings, we found optogenetic stimulation of PVT OTR terminals excited neurons in the posterior basolateral amygdala (pBLA) and nucleus accumbens core (NAcC) as well as local PVT neurons through monosynaptic glutamatergic transmissions. Photostimulation of OTR-expressing PVT-NAcC projections promoted food-seeking, whereas selective activation of PVT-pBLA projections produced little effect on feeding. In contrast to selective activation of OTR terminals, photostimulation of a broader population of glutamatergic PVT terminals exerted direct excitation followed by indirect lateral inhibition on neurons in both NAcC and anterior basolateral amygdala. Together, these results suggest that OTR-expressing PVT neurons are a distinct population of PVT glutamate neurons that regulate feeding motivation through projections to NAcC.SIGNIFICANCE STATEMENT The paraventricular thalamus plays an important role in the regulation of feeding motivation. However, because of the diversity of paraventricular thalamic neurons, the specific neuron types promoting food motivation remain elusive. In this study, we provide evidence that oxytocin receptor-expressing neurons are a specific group of glutamate neurons that primarily project to the nucleus accumbens core and posterior amygdala. We found that activation of these neurons promotes the motivation for food reward and increases meal frequency through projections to the nucleus accumbens core but not the posterior amygdala. As a result, we postulate that oxytocin receptor-expressing neurons in the paraventricular thalamus and their projections to the nucleus accumbens core mainly regulate feeding motivation but not food consumption.
Collapse
Affiliation(s)
- Qiying Ye
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| | - Jeremiah Nunez
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| | - Xiaobing Zhang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| |
Collapse
|
14
|
Volcko KL, Brakey DJ, McNamara TE, Meyer MJ, McKay NJ, Santollo J, Daniels D. Control of water intake by a pathway from the nucleus of the solitary tract to the paraventricular hypothalamic nucleus. Appetite 2022; 172:105943. [PMID: 35131386 PMCID: PMC9903207 DOI: 10.1016/j.appet.2022.105943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/14/2021] [Accepted: 01/17/2022] [Indexed: 11/19/2022]
Abstract
Several brain areas have been shown to participate in thirst and control of fluid intake. An understanding of how these circuits interact, and their roles in the activation, maintenance, and termination of fluid intake remains incomplete. Central glucagon-like peptide-1 (GLP-1) receptor activation appears to be an important part of the termination of drinking, but the site(s) of action for this suppression has not yet been determined. In an attempt to use GLP-1 responsiveness as a means to screen targets of hindbrain cells that participate in the termination of thirst and the resultant water intake, we injected the GLP-1 receptor agonist exendin-4 (Ex-4) into three brain areas known to express GLP-1 receptors, and measured subsequent water intake. Ex-4 reduced water consumption when injected into the paraventricular hypothalamic nucleus (PVH) and nucleus of the solitary tract (NTS), but not when injected into the nucleus accumbens (NAc). Using the effective response after injection into the PVH as a guide, we examined the connection between the NTS - the site of endogenous central GLP-1 production - and the PVH. Retrograde tracing combined with Fos immunohistochemistry suggested intake-induced activity in PVH-projecting NTS cells. To test the hypothesis that this pathway is important in the termination of drinking, we chemogenetically activated PVH-projecting hindbrain cells. Interestingly, activation of this population of cells increased water intake, calling into question the heterogeneity of the pathway with respect to the control of fluid intake. Taken together, we conclude that the PVH is a site of action for GLP-1 receptor activation in the inhibition of water intake, but suspect that endogenous GLP-1 in NTS-to-PVH projections may be counterbalanced by a parallel pathway that either activates or maintains already activated water intake.
Collapse
Affiliation(s)
- K L Volcko
- Department of Psychology, USA; Behavioral Neuroscience Program, USA
| | - D J Brakey
- Department of Psychology, USA; Behavioral Neuroscience Program, USA
| | | | | | - N J McKay
- Department of Psychology, State University of New York Buffalo State College,Buffalo, NY, 14222, USA
| | - J Santollo
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
| | - D Daniels
- Department of Psychology, USA; Behavioral Neuroscience Program, USA; Center for Ingestive Behavior Research. University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA.
| |
Collapse
|
15
|
Linagliptin, a Selective Dipeptidyl Peptidase-4 Inhibitor, Reduces Physical and Behavioral Effects of Morphine Withdrawal. Molecules 2022; 27:molecules27082478. [PMID: 35458676 PMCID: PMC9028142 DOI: 10.3390/molecules27082478] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/18/2022] [Accepted: 04/11/2022] [Indexed: 11/17/2022] Open
Abstract
(1) Background: Recent data indicate that receptors for GLP-1 peptide are involved in the activity of the mesolimbic system. Thus, the purpose of the present study was to examine the effect of the selective dipeptidyl peptidase-4 (DPP-4) inhibitor, linagliptin, on morphine dependence in mice. (2) Methods: Morphine dependence in mice was obtained by administration of increasing doses of morphine for eight consecutive days, twice a day. On the 9th day of the experiment, the naloxone-induced (2 mg/kg, ip) morphine withdrawal signs (jumping) were assessed. Moreover, behavioral effects of short-term (60 h after morphine discontinuation) and long-term (14 days after morphine discontinuation) morphine withdrawal were observed. In terms of behavioral effects, the depressive effect in the forced swim test and anxiety in the elevated plus maze test were investigated. Locomotor activity of mice was also studied. (3) Results: The administration of linagliptin (10 and 20 mg/kg, ip) for 8 consecutive days before morphine injections significantly diminished the number of naloxone-induced morphine withdrawal signs (jumping) in mice. In addition, the cessation of morphine administration induced depressive behavior in mice which were observed during short- and long-term morphine withdrawal. Linagliptin administered during morphine withdrawal significantly reduced the depressive behavior in studied mice. Furthermore, the short-term morphine withdrawal evoked anxiety which also was reduced by linagliptin in mice. (4) Conclusions: The present study reveals that GLP-1 receptors are involved in morphine dependence. What is more, linagliptin might be a valuable drug in attenuating the physical symptoms of morphine dependence. It might be also a useful drug in reducing emotional disturbances which may develop during the morphine withdrawal period.
Collapse
|
16
|
The Impact of Binge-Like Palatable Food Intake on the Endogenous Glucagon-Like Peptide-1 System in Female Rats. Behav Brain Res 2022; 428:113869. [PMID: 35378108 DOI: 10.1016/j.bbr.2022.113869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 03/08/2022] [Accepted: 03/29/2022] [Indexed: 11/21/2022]
Abstract
Binge eating involves consumption of large amounts of food and a loss of control over the amount consumed. The incidence of binge eating disorder is higher in females than males, hinting at important sex differences in binge eating behavior, but the neural underpinnings of binge eating still remain unresolved. Recent work in male rats has shown that a history of binge-like palatable food intake suppresses hindbrain expression of preproglucagon (PPG), the precursor for glucagon-like peptide-1 (GLP-1). Given the roles of GLP-1 in reducing feeding and food reward, this could be a mechanism underlying binge-like eating in rodents. However, whether similar effects occur in female rats is unknown. Here, we tested the hypothesis that a history of binge-like palatable food intake in female rats would reduce PPG expression in the nucleus tractus solitarius (NTS), a key central site of GLP-1 production. Female rats given access to vegetable shortening every fourth day (4D) engaged in binge-like feeding, demonstrated by consuming significantly more shortening during the first hour of fat access compared to counterparts with ad libitum (AL) fat access. After several weeks of fat access under these schedules, PPG and GLP-1 receptor (GLP-1R) expression were measured in the NTS and ileum. Surprisingly, and in contrast to previous findings in male rats, there were no significant differences in expression of PPG or GLP-1R in either site in 4D versus AL rats, nor were there effects on plasma GLP-1 levels. These findings highlight key differences in the effects of binge-like intake on the central GLP-1 system in female compared to male rats.
Collapse
|
17
|
Keller BN, Hajnal A, Browning KN, Arnold AC, Silberman Y. Involvement of the Dorsal Vagal Complex in Alcohol-Related Behaviors. Front Behav Neurosci 2022; 16:801825. [PMID: 35330845 PMCID: PMC8940294 DOI: 10.3389/fnbeh.2022.801825] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/19/2022] [Indexed: 12/20/2022] Open
Abstract
The neurobiological mechanisms that regulate the development and maintenance of alcohol use disorder (AUD) are complex and involve a wide variety of within and between systems neuroadaptations. While classic reward, preoccupation, and withdrawal neurocircuits have been heavily studied in terms of AUD, viable treatment targets from this established literature have not proven clinically effective as of yet. Therefore, examination of additional neurocircuitries not classically studied in the context of AUD may provide novel therapeutic targets. Recent studies demonstrate that various neuropeptides systems are important modulators of alcohol reward, seeking, and intake behaviors. This includes neurocircuitry within the dorsal vagal complex (DVC), which is involved in the control of the autonomic nervous system, control of intake of natural rewards like food, and acts as a relay of interoceptive sensory information via interactions of numerous gut-brain peptides and neurotransmitter systems with DVC projections to central and peripheral targets. DVC neuron subtypes produce a variety of neuropeptides and transmitters and project to target brain regions critical for reward such as the mesolimbic dopamine system as well as other limbic areas important for the negative reinforcing and aversive properties of alcohol withdrawal such as the extended amygdala. This suggests the DVC may play a role in the modulation of various aspects of AUD. This review summarizes the current literature on neurotransmitters and neuropeptides systems in the DVC (e.g., norepinephrine, glucagon-like peptide 1, neurotensin, cholecystokinin, thyrotropin-releasing hormone), and their potential relevance to alcohol-related behaviors in humans and rodent models for AUD research. A better understanding of the role of the DVC in modulating alcohol related behaviors may lead to the elucidation of novel therapeutic targets for drug development in AUD.
Collapse
|
18
|
Woodward ORM, Gribble FM, Reimann F, Lewis JE. Gut peptide regulation of food intake - evidence for the modulation of hedonic feeding. J Physiol 2022; 600:1053-1078. [PMID: 34152020 DOI: 10.1113/jp280581] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/17/2021] [Indexed: 12/13/2022] Open
Abstract
The number of people living with obesity has tripled worldwide since 1975 with serious implications for public health, as obesity is linked to a significantly higher chance of early death from associated comorbidities (metabolic syndrome, type 2 diabetes, cardiovascular disease and cancer). As obesity is a consequence of food intake exceeding the demands of energy expenditure, efforts are being made to better understand the homeostatic and hedonic mechanisms governing food intake. Gastrointestinal peptides are secreted from enteroendocrine cells in response to nutrient and energy intake, and modulate food intake either via afferent nerves, including the vagus nerve, or directly within the central nervous system, predominantly gaining access at circumventricular organs. Enteroendocrine hormones modulate homeostatic control centres at hypothalamic nuclei and the dorso-vagal complex. Additional roles of these peptides in modulating hedonic food intake and/or preference via the neural systems of reward are starting to be elucidated, with both peripheral and central peptide sources potentially contributing to central receptor activation. Pharmacological interventions and gastric bypass surgery for the treatment of type 2 diabetes and obesity elevate enteroendocrine hormone levels and also alter food preference. Hence, understanding of the hedonic mechanisms mediated by gut peptide action could advance development of potential therapeutic strategies for the treatment of obesity and its comorbidities.
Collapse
Affiliation(s)
- Orla R M Woodward
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Fiona M Gribble
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Frank Reimann
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Jo E Lewis
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| |
Collapse
|
19
|
Chen XY, Chen L, Yang W, Xie AM. GLP-1 Suppresses Feeding Behaviors and Modulates Neuronal Electrophysiological Properties in Multiple Brain Regions. Front Mol Neurosci 2022; 14:793004. [PMID: 34975402 PMCID: PMC8718614 DOI: 10.3389/fnmol.2021.793004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/29/2021] [Indexed: 11/24/2022] Open
Abstract
The glucagon-like peptide-1 (GLP-1) plays important roles in the regulation of food intake and energy metabolism. Peripheral or central GLP-1 suppresses food intake and reduces body weight. The electrophysiological properties of neurons in the mammalian central nervous system reflect the neuronal excitability and the functional organization of the brain. Recent studies focus on elucidating GLP-1-induced suppression of feeding behaviors and modulation of neuronal electrophysiological properties in several brain regions. Here, we summarize that activation of GLP-1 receptor (GLP-1R) suppresses food intake and induces postsynaptic depolarization of membrane potential and/or presynaptic modulation of glutamatergic or GABAergic neurotransmission in brain nuclei located within the medulla oblongata, pons, mesencephalon, diencephalon, and telencephalon. This review may provide a background to guide future research about the cellular mechanisms of GLP-1-induced feeding inhibition.
Collapse
Affiliation(s)
- Xin-Yi Chen
- Department of International Medicine, Affiliated Hospital of Qingdao University, Qingdao, China.,Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Wu Yang
- Department of International Medicine, Affiliated Hospital of Qingdao University, Qingdao, China
| | - An-Mu Xie
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| |
Collapse
|
20
|
Parent MB, Higgs S, Cheke LG, Kanoski SE. Memory and eating: A bidirectional relationship implicated in obesity. Neurosci Biobehav Rev 2022; 132:110-129. [PMID: 34813827 PMCID: PMC8816841 DOI: 10.1016/j.neubiorev.2021.10.051] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 10/17/2021] [Accepted: 10/28/2021] [Indexed: 01/03/2023]
Abstract
This paper reviews evidence demonstrating a bidirectional relationship between memory and eating in humans and rodents. In humans, amnesia is associated with impaired processing of hunger and satiety cues, disrupted memory of recent meals, and overconsumption. In healthy participants, meal-related memory limits subsequent ingestive behavior and obesity is associated with impaired memory and disturbances in the hippocampus. Evidence from rodents suggests that dorsal hippocampal neural activity contributes to the ability of meal-related memory to control future intake, that endocrine and neuropeptide systems act in the ventral hippocampus to provide cues regarding energy status and regulate learned aspects of eating, and that consumption of hypercaloric diets and obesity disrupt these processes. Collectively, this evidence indicates that diet-induced obesity may be caused and/or maintained, at least in part, by a vicious cycle wherein excess intake disrupts hippocampal functioning, which further increases intake. This perspective may advance our understanding of how the brain controls eating, the neural mechanisms that contribute to eating-related disorders, and identify how to treat diet-induced obesity.
Collapse
Affiliation(s)
- Marise B Parent
- Neuroscience Institute & Department of Psychology, Georgia State University, Box 5030, Atlanta, GA 30303-5030, United States.
| | - Suzanne Higgs
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, BI5 2TT, United Kingdom.
| | - Lucy G Cheke
- Department of Psychology, University of Cambridge, Downing Street, Cambridge, CB2 3EB, United Kingdom.
| | - Scott E Kanoski
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, 90089-0371, United States.
| |
Collapse
|
21
|
Müller TD, Blüher M, Tschöp MH, DiMarchi RD. Anti-obesity drug discovery: advances and challenges. Nat Rev Drug Discov 2022; 21:201-223. [PMID: 34815532 PMCID: PMC8609996 DOI: 10.1038/s41573-021-00337-8] [Citation(s) in RCA: 369] [Impact Index Per Article: 184.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2021] [Indexed: 12/27/2022]
Abstract
Enormous progress has been made in the last half-century in the management of diseases closely integrated with excess body weight, such as hypertension, adult-onset diabetes and elevated cholesterol. However, the treatment of obesity itself has proven largely resistant to therapy, with anti-obesity medications (AOMs) often delivering insufficient efficacy and dubious safety. Here, we provide an overview of the history of AOM development, focusing on lessons learned and ongoing obstacles. Recent advances, including increased understanding of the molecular gut-brain communication, are inspiring the pursuit of next-generation AOMs that appear capable of safely achieving sizeable and sustained body weight loss.
Collapse
Affiliation(s)
- Timo D. Müller
- grid.4567.00000 0004 0483 2525Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, Neuherberg, Germany ,grid.452622.5German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Matthias Blüher
- grid.411339.d0000 0000 8517 9062Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Matthias H. Tschöp
- grid.4567.00000 0004 0483 2525Helmholtz Zentrum München, Neuherberg, Germany ,grid.6936.a0000000123222966Division of Metabolic Diseases, Department of Medicine, Technische Universität München, München, Germany
| | - Richard D. DiMarchi
- grid.411377.70000 0001 0790 959XDepartment of Chemistry, Indiana University, Bloomington, IN USA
| |
Collapse
|
22
|
Colvin KJ, Killen HS, Kanter MJ, Halperin MC, Engel L, Dickinson MB, Fimmel AI, Holland JG, Currie PJ. Differential effects of intra-ventral tegmental area ghrelin and glucagon-like peptide-1 on the stimulatory action of D-amphetamine and cocaine-induced ethanol intake in male Sprague Dawley rats. Behav Brain Res 2021; 421:113726. [PMID: 34954300 DOI: 10.1016/j.bbr.2021.113726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 12/24/2022]
Abstract
In order to further elucidate the role of mesolimbic peptides in the expression of ethanol reward, the present study investigated the effects of ghrelin and glucagon-like peptide-1 (GLP-1) on ethanol intake, in addition to ethanol intake stimulated by systemic d-amphetamine or cocaine treatment. While a number of studies suggest that ghrelin plays an important role in mesolimbic reward, emerging data now indicate that GLP-1 receptor mechanisms inhibit reward signaling, possibly by directly or indirectly inhibiting ghrelinergic activity within the mesolimbic system. In the present study all rats were initially habituated to a 6% ethanol solution. We then demonstrated that intraperitoneal injections of d-amphetamine and cocaine increased ethanol intake compared to the vehicle condition. In subsequent testing we examined the effects of ventral tegmental area (VTA) ghrelin or vehicle paired with a fixed dose of d-amphetamine or vehicle. In separate rats we then investigated the impact of the GLP-1 agonist exendin-4 (Ex-4), injected into the VTA, on ethanol intake alone, or when Ex-4 was co-administered with d-amphetamine or cocaine. Our results indicated that VTA ghrelin significantly increased ethanol intake, and most importantly, potentiated the effect of d-amphetamine and cocaine on ethanol consumption. Conversely, VTA Ex-4 inhibited ethanol intake and antagonized the stimulatory effect of d-amphetamine and cocaine on ethanol consumption. In a final study we further demonstrated that VTA Ex-4 treatment significantly inhibited the combined stimulatory effects of ghrelin paired with d-amphetamine or ghrelin paired with cocaine. Overall our findings are consistent with a critical role for both ghrelin and GLP-1 receptor mechanisms in mesolimbic ethanol reward circuitry. Moreover, our results further suggest that ghrelin and GLP-1 modulate the stimulatory effect of psychostimulants on ethanol intake.
Collapse
Affiliation(s)
- Kayla J Colvin
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Henry S Killen
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Maxwell J Kanter
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Maximilian C Halperin
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Liv Engel
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Matthew B Dickinson
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Anna I Fimmel
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - James G Holland
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA
| | - Paul J Currie
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA.
| |
Collapse
|
23
|
A novel approach to treating opioid use disorders: Dual agonists of glucagon-like peptide-1 receptors and neuropeptide Y 2 receptors. Neurosci Biobehav Rev 2021; 131:1169-1179. [PMID: 34715149 DOI: 10.1016/j.neubiorev.2021.10.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 12/15/2022]
Abstract
The widespread misuse of opioids and opioid use disorder (OUD) together constitute a major public health crisis in the United States. The greatest challenge for successfully treating OUD is preventing relapse. Unfortunately, there are few FDA-approved medications to treat OUD and, while effective, these pharmacotherapies are limited by high relapse rates. Thus, there is a critical need for conceptually new approaches to developing novel medications to treat OUD. Here, we review an emerging preclinical literature that suggests that glucagon-like peptide-1 receptor (GLP-1R) agonists could be re-purposed for treating OUD. Potential limitations of this approach are also discussed along with an alternative strategy that involves simultaneously targeting and activating GLP-1Rs and neuropeptide Y2 receptors (Y2Rs) in the brain using a novel monomeric dual agonist peptide. Recent studies indicate that this combinatorial pharmacotherapy approach attenuates voluntary fentanyl taking and seeking in rats without producing adverse effects associated with GLP-1R agonist monotherapy alone. While future studies are required to comprehensively determine the behavioral effects of GLP-1R agonists and dual agonists of GLP-1Rs and Y2Rs in rodent models of OUD, these provocative preclinical findings highlight a potential new GLP-1R-based approach to preventing relapse in humans with OUD.
Collapse
|
24
|
de Almeida VBP, Filgueiras AR, Nogueira PCK, Sesso RC, Sawaya AL, Domene SMÁ. The impact of food addiction behaviours on the treatment of overweight students. Br J Nutr 2021; 129:1-8. [PMID: 34657642 DOI: 10.1017/s0007114521004189] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The present study evaluated the association of food addiction (FA), the change of the BMI/age z-score and the consumption of ultra-processed foods in overweight students undergoing a 16-month, multicomponent intervention in the school environment. FA was investigated using the Yale Food Addiction Scale for Children, and the dietary assessment was estimated using the semi-quantitative FFQ in overweight 9-11-year-old students (BMI/age z-score ≥ 1) of both sexes at their baseline and after the intervention (n 120). Among the schoolchildren, 33·4 % had FA in at least one of the two assessments. The analysis of mixed-effects models to assess the effect of the intervention and the change of the BMI/age z-score between evaluations showed that the occurrence of FA influenced the maintenance of weight (time#FA, β = 0·30, 95 % CI 0·05, 0·54, P = 0·016). Weight loss was observed only in individuals who did not present FA (BMI/age z-score = -0·3). When evaluating the effect of the intervention and the dietary variables, we verified a reduction in the consumption of sugary milk-based drinks -71·13 kJ (-17 kcal), P = 0·04 only in non-FA students at the end of the study. FA has been identified as an underlying factor with therapeutic relevance, and an enhanced understanding of FA can open new paths for the prevention and management of obesity.
Collapse
Affiliation(s)
| | | | | | - Ricardo Cintra Sesso
- Department of Medicine, Federal University of São Paulo UNIFESP, São Paulo, SP, Brazil
| | - Ana Lydia Sawaya
- Department of Physiology, Federal University of São Paulo UNIFESP, São Paulo, SP, Brazil
| | | |
Collapse
|
25
|
Drucker DJ. GLP-1 physiology informs the pharmacotherapy of obesity. Mol Metab 2021; 57:101351. [PMID: 34626851 PMCID: PMC8859548 DOI: 10.1016/j.molmet.2021.101351] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/28/2021] [Accepted: 10/02/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Glucagon-like peptide-1 receptor agonists (GLP1RA) augment glucose-dependent insulin release and reduce glucagon secretion and gastric emptying, enabling their successful development for the treatment of type 2 diabetes (T2D). These agents also inhibit food intake and reduce body weight, fostering investigation of GLP1RA for the treatment of obesity. SCOPE OF REVIEW Here I discuss the physiology of Glucagon-like peptide-1 (GLP-1) action in the control of food intake in animals and humans, highlighting the importance of gut vs. brain-derived GLP-1 for the control of feeding and body weight. The widespread distribution and function of multiple GLP-1 receptor (GLP1R) populations in the central and autonomic nervous system are outlined, and the importance of pathways controlling energy expenditure in preclinical studies vs. reduction of food intake in both animals and humans is highlighted. The relative contributions of vagal afferent pathways vs. GLP1R+ populations in the central nervous system for the physiological reduction of food intake and the anorectic response to GLP1RA are compared and reviewed. Key data enabling the development of two GLP1RA for obesity therapy (liraglutide 3 mg daily and semaglutide 2.4 mg once weekly) are discussed. Finally, emerging data potentially supporting the combination of GLP-1 with additional peptide epitopes in unimolecular multi-agonists, as well as in fixed-dose combination therapies, are highlighted. MAJOR CONCLUSIONS The actions of GLP-1 to reduce food intake and body weight are highly conserved in obese animals and humans, in both adolescents and adults. The well-defined mechanisms of GLP-1 action through a single G protein-coupled receptor, together with the extensive safety database of GLP1RA in people with T2D, provide reassurance surrounding the long-term use of these agents in people with obesity and multiple co-morbidities. GLP1RA may also be effective in conditions associated with obesity, such as cardiovascular disease and non-alcoholic steatohepatitis (NASH). Progressive improvements in the efficacy of GLP1RA suggest that GLP-1-based therapies may soon rival bariatric surgery as viable options for the treatment of obesity and its complications.
Collapse
Affiliation(s)
- Daniel J Drucker
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada.
| |
Collapse
|
26
|
Graham DL, Madkour HS, Noble BL, Schatschneider C, Stanwood GD. Long-term functional alterations following prenatal GLP-1R activation. Neurotoxicol Teratol 2021; 87:106984. [PMID: 33864929 PMCID: PMC8555578 DOI: 10.1016/j.ntt.2021.106984] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/29/2021] [Accepted: 04/09/2021] [Indexed: 12/11/2022]
Abstract
Evidence supporting the use of glucagon-like peptide-1 (GLP-1) analogues to pharmacologically treat disorders beyond type 2 diabetes and obesity is increasing. However, little is known about how activation of the GLP-1 receptor (GLP-1R) during pregnancy affects maternal and offspring outcomes. We treated female C57Bl/6 J mice prior to conception and throughout gestation with a long-lasting GLP-1R agonist, Exendin-4. While GLP-1R activation has significant effects on food and drug reward, depression, locomotor activity, and cognition in adults, we found few changes in these domains in exendin-4-exposed offspring. Repeated injections of Exendin-4 had minimal effects on the dams and may have enhanced maternal care. Offspring exposed to the drug weighed significantly more than their control counterparts during the preweaning period and demonstrated alterations in anxiety-like outcomes, which indicate a developmental role for GLP-1R modulation in the stress response that may be sex-specific.
Collapse
Affiliation(s)
- Devon L Graham
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, FL 32306, United States of America
| | - Haley S Madkour
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, FL 32306, United States of America
| | - Brenda L Noble
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, FL 32306, United States of America
| | - Chris Schatschneider
- Department of Psychology, Florida State University, Tallahassee, FL 32306, United States of America
| | - Gregg D Stanwood
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, FL 32306, United States of America.
| |
Collapse
|
27
|
Guerrero-Hreins E, Goldstone AP, Brown RM, Sumithran P. The therapeutic potential of GLP-1 analogues for stress-related eating and role of GLP-1 in stress, emotion and mood: a review. Prog Neuropsychopharmacol Biol Psychiatry 2021; 110:110303. [PMID: 33741445 DOI: 10.1016/j.pnpbp.2021.110303] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/19/2021] [Accepted: 03/09/2021] [Indexed: 01/11/2023]
Abstract
Stress and low mood are powerful triggers for compulsive overeating, a maladaptive form of eating leading to negative physical and mental health consequences. Stress-vulnerable individuals, such as people with obesity, are particularly prone to overconsumption of high energy foods and may use it as a coping mechanism for general life stressors. Recent advances in the treatment of obesity and related co-morbidities have focused on the therapeutic potential of anorexigenic gut hormones, such as glucagon-like peptide 1 (GLP-1), which acts both peripherally and centrally to reduce energy intake. Besides its appetite suppressing effect, GLP-1 acts on areas of the brain involved in stress response and emotion regulation. However, the role of GLP-1 in emotion and stress regulation, and whether it is a viable treatment for stress-induced compulsive overeating, has yet to be established. A thorough review of the pre-clinical literature measuring markers of stress, anxiety and mood after GLP-1 exposure points to potential divergent effects based on temporality. Specifically, acute GLP-1 injection consistently stimulates the physiological stress response in rodents whereas long-term exposure indicates anxiolytic and anti-depressive benefits. However, the limited clinical evidence is not as clear cut. While prolonged GLP-1 analogue treatment in people with type 2 diabetes improved measures of mood and general psychological wellbeing, the mechanisms underlying this may be confounded by associated weight loss and improved blood glucose control. There is a paucity of longitudinal clinical literature on mechanistic pathways by which stress influences eating behavior and how centrally-acting gut hormones such as GLP-1, can modify these. (250).
Collapse
Affiliation(s)
- Eva Guerrero-Hreins
- The Florey Institute of Neuroscience and Mental Health, Mental Health Theme, Parkville, Melbourne, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia; PsychoNeuroEndocrinology Research Group, Centre for Neuropsychopharmacology, Division of Psychiatry, and Computational, Cognitive and Clinical Neuroimaging Laboratory, Department of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
| | - Anthony P Goldstone
- PsychoNeuroEndocrinology Research Group, Centre for Neuropsychopharmacology, Division of Psychiatry, and Computational, Cognitive and Clinical Neuroimaging Laboratory, Department of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
| | - Robyn M Brown
- The Florey Institute of Neuroscience and Mental Health, Mental Health Theme, Parkville, Melbourne, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Priya Sumithran
- Department of Medicine (St Vincent's), University of Melbourne, Victoria, Australia; Dept. of Endocrinology, Austin Health, Victoria, Australia.
| |
Collapse
|
28
|
Trapp S, Brierley DI. Brain GLP-1 and the regulation of food intake: GLP-1 action in the brain and its implications for GLP-1 receptor agonists in obesity treatment. Br J Pharmacol 2021; 179:557-570. [PMID: 34323288 PMCID: PMC8820179 DOI: 10.1111/bph.15638] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/22/2021] [Accepted: 07/03/2021] [Indexed: 12/19/2022] Open
Abstract
This review considers the similarities and differences between the physiological systems regulated by gut-derived and neuronally produced glucagon-like peptide 1 (GLP-1). It addresses the questions of whether peripheral and central GLP-1 sources constitute separate, linked or redundant systems and whether the brain GLP-1 system consists of disparate sections or is a homogenous entity. This review also explores the implications of the answers to these questions for the use of GLP-1 receptor agonists as anti-obesity drugs.
Collapse
Affiliation(s)
- Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Daniel I Brierley
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| |
Collapse
|
29
|
Reconsolidation of a post-ingestive nutrient memory requires mTOR in the central amygdala. Mol Psychiatry 2021; 26:2820-2836. [PMID: 32873898 DOI: 10.1038/s41380-020-00874-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/04/2020] [Accepted: 08/21/2020] [Indexed: 01/22/2023]
Abstract
The central control of feeding behavior and metabolic homeostasis has been proposed to involve a form of post-ingestive nutrient learning independent of the gustatory value of food. However, after such learning, it is unknown which brain regions or circuits are activated to retrieve the stored memory and whether this memory undergoes reconsolidation that depends on protein synthesis after its reactivation through retrieval. In the present study, using a conditioned-flavor-preference paradigm by associating flavors with intra-gastric infusion of glucose to minimize the evaluation of the taste of food, we show that retrieval of the post-ingestive nutrient-conditioned flavor memory stimulates multiple brain regions in mice, including the central nucleus of the amygdala (CeA). Moreover, memory retrieval activated the mammalian target of rapamycin complex 1 (mTORC1) in the CeA, while site-specific or systemic inhibition of mTORC1 immediately after retrieval prevented the subsequent expression of the post-ingestive nutrient-associated flavor memory, leading to a long-lasting suppression of reinstatement. Taken together, our findings suggest that the reconsolidation process of a post-ingestive nutrient memory modulates food preferences.
Collapse
|
30
|
Maejima Y, Yokota S, Shimizu M, Horita S, Kobayashi D, Hazama A, Shimomura K. The deletion of glucagon-like peptide-1 receptors expressing neurons in the dorsomedial hypothalamic nucleus disrupts the diurnal feeding pattern and induces hyperphagia and obesity. Nutr Metab (Lond) 2021; 18:58. [PMID: 34098999 PMCID: PMC8186199 DOI: 10.1186/s12986-021-00582-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 05/27/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Feeding rhythm disruption contributes to the development of obesity. The receptors of glucagon-like peptide-1 (GLP-1) are distributed in the wide regions of the brain. Among these regions, GLP-1 receptors (GLP-1R) are expressed in the dorsomedial hypothalamic nucleus (DMH) which are known to be associated with thermogenesis and circadian rhythm development. However, the physiological roles of GLP-1R expressing neurons in the DMH remain elusive. METHODS To examine the physiological role of GLP-1R expressing neurons in the DMH, saporin-conjugated exenatide4 was injected into rat brain DMH to delete GLP-1R-positive neurons. Subsequently, locomotor activity, diurnal feeding pattern, amount of food intake and body weight were measured. RESULTS This deletion of GLP-1R-positive neurons in the DMH induced hyperphagia, the disruption of diurnal feeding pattern, and obesity. The deletion of GLP-1R expressing neurons also reduced glutamic acid decarboxylase 67 and cholecystokinin A receptor mRNA levels in the DMH. Also, it reduced the c-fos expression after refeeding in the suprachiasmatic nucleus (SCN). Thirty percent of DMH neurons projecting to the SCN expressed GLP-1R. Functionally, refeeding after fasting induced c-fos expression in the SCN projecting neurons in the DMH. As for the projection to the DMH, neurons in the nucleus tractus solitarius (NTS) were found to be projecting to the DMH, with 33% of those neurons being GLP-1-positive. Refeeding induced c-fos expression in the DMH projecting neurons in the NTS. CONCLUSION These findings suggest that GLP-1R expressing neurons in the DMH may mediate feeding termination. In addition, this meal signal may be transmitted to SCN neurons and change the neural activities.
Collapse
Affiliation(s)
- Yuko Maejima
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan.
| | - Shoko Yokota
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Masaru Shimizu
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Shoichiro Horita
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Daisuke Kobayashi
- Department of Cellular and Integrative Physiology, Fukushima University School of Medicine, Fukushima, 960-1295, Japan
| | - Akihiro Hazama
- Department of Cellular and Integrative Physiology, Fukushima University School of Medicine, Fukushima, 960-1295, Japan
| | - Kenju Shimomura
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| |
Collapse
|
31
|
Williams DL. The diverse effects of brain glucagon-like peptide 1 receptors on ingestive behaviour. Br J Pharmacol 2021; 179:571-583. [PMID: 33990944 DOI: 10.1111/bph.15535] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 04/12/2021] [Accepted: 05/07/2021] [Indexed: 12/31/2022] Open
Abstract
Glucagon-like peptide 1 (GLP-1) is well known as a gut hormone and also acts as a neuropeptide, produced in a discrete population of caudal brainstem neurons that project widely throughout the brain. GLP-1 receptors are expressed in many brain areas of relevance to energy balance, and stimulation of these receptors at many of these sites potently suppresses food intake. This review surveys the current evidence for effects mediated by GLP-1 receptors on feeding behaviour at a wide array of brain sites and discusses behavioural and neurophysiological mechanisms for the effects identified thus far. Taken together, it is clear that GLP-1 receptor activity in the brain can influence feeding by diverse means, including mediation of gastrointestinal satiation and/or satiety signalling, suppression of motivation for food reward, induction of nausea and mediation of restraint stress-induced hypophagia, but many questions about the organization of this system remain.
Collapse
Affiliation(s)
- Diana L Williams
- Department of Psychology, Program in Neuroscience, Florida State University, Tallahassee, Florida, USA
| |
Collapse
|
32
|
Yammine L, Green CE, Kosten TR, de Dios C, Suchting R, Lane SD, Verrico CD, Schmitz JM. Exenatide Adjunct to Nicotine Patch Facilitates Smoking Cessation and May Reduce Post-Cessation Weight Gain: A Pilot Randomized Controlled Trial. Nicotine Tob Res 2021; 23:1682-1690. [PMID: 33831213 DOI: 10.1093/ntr/ntab066] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 04/05/2021] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Approved pharmacological treatments for smoking cessation are modestly effective, underscoring the need for improved pharmacotherapies. Glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate the rewarding effects of nicotine in preclinical studies. We examined the efficacy of extended-release exenatide, a GLP-1R agonist, combined with nicotine replacement therapy (NRT, patch) for smoking cessation, craving, and withdrawal symptoms, with post-cessation body weight as a secondary outcome. METHODS Eighty-four prediabetic and/or overweight smokers were randomized (1 : 1) to once-weekly placebo or exenatide, 2 mg, subcutaneously. All participants received NRT (21 mg) and brief smoking cessation counseling. Seven-day point prevalence abstinence (expired CO level ≤5 ppm), craving, withdrawal, and post-cessation body weight were assessed following 6 weeks of treatment. A Bayesian approach for analyzing generalized linear models yielded posterior probabilities (PP) to quantify the evidence favoring hypothesized effects of treatment on the study outcomes. RESULTS Exenatide increased the risk for smoking abstinence compared to placebo (46.3% and 26.8%, respectively), (risk ratio [RR] = 1.70; 95% credible interval = [0.96, 3.27]; PP = 96.5%). Exenatide reduced end-of-treatment craving in the overall sample and withdrawal among abstainers. Post-cessation body weight was 5.6 pounds lower in the exenatide group compared to placebo (PP = 97.4%). Adverse events were reported in 9.5% and 2.3% of participants in the exenatide and placebo groups, respectively. CONCLUSIONS Exenatide, in combination with the NRT improved smoking abstinence, reduced craving and withdrawal symptoms, and decreased weight gain among abstainers. Findings suggest that the GLP-1R agonist strategy is worthy of further research in larger, longer duration studies. IMPLICATIONS Despite considerable progress in tobacco control, cigarette smoking remains the leading cause of preventable disease, disability, and death. In this pilot study, we showed that extended-release exenatide, a glucagon-like peptide-1 receptor agonist, added to the nicotine patch, improved abstinence and mitigated post-cessation body weight gain compared to patch alone. Further research is needed to confirm these initial positive results.
Collapse
Affiliation(s)
- Luba Yammine
- Louis A. Faillace, M.D., Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston (UTHealth), McGovern Medical School, Houston, TX, USA
| | - Charles E Green
- Department of Pediatrics, Center for Clinical Research and Evidence-Based Medicine, UTHealth, McGovern Medical School, Houston, TX, USA
| | - Thomas R Kosten
- Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA.,Michael E. DeBakey VA Medical Center, Houston TX, USA
| | - Constanza de Dios
- Louis A. Faillace, M.D., Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston (UTHealth), McGovern Medical School, Houston, TX, USA
| | - Robert Suchting
- Louis A. Faillace, M.D., Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston (UTHealth), McGovern Medical School, Houston, TX, USA
| | - Scott D Lane
- Louis A. Faillace, M.D., Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston (UTHealth), McGovern Medical School, Houston, TX, USA
| | - Christopher D Verrico
- Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA.,Michael E. DeBakey VA Medical Center, Houston TX, USA
| | - Joy M Schmitz
- Louis A. Faillace, M.D., Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston (UTHealth), McGovern Medical School, Houston, TX, USA
| |
Collapse
|
33
|
Schalla MA, Taché Y, Stengel A. Neuroendocrine Peptides of the Gut and Their Role in the Regulation of Food Intake. Compr Physiol 2021; 11:1679-1730. [PMID: 33792904 DOI: 10.1002/cphy.c200007] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The regulation of food intake encompasses complex interplays between the gut and the brain. Among them, the gastrointestinal tract releases different peptides that communicate the metabolic state to specific nuclei in the hindbrain and the hypothalamus. The present overview gives emphasis on seven peptides that are produced by and secreted from specialized enteroendocrine cells along the gastrointestinal tract in relation with the nutritional status. These established modulators of feeding are ghrelin and nesfatin-1 secreted from gastric X/A-like cells, cholecystokinin (CCK) secreted from duodenal I-cells, glucagon-like peptide 1 (GLP-1), oxyntomodulin, and peptide YY (PYY) secreted from intestinal L-cells and uroguanylin (UGN) released from enterochromaffin (EC) cells. © 2021 American Physiological Society. Compr Physiol 11:1679-1730, 2021.
Collapse
Affiliation(s)
- Martha A Schalla
- Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Yvette Taché
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, CURE: Digestive Diseases Research Center, David Geffen School of Medicine, UCLA, Los Angeles, California, USA.,VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Andreas Stengel
- Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.,Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
| |
Collapse
|
34
|
Decarie-Spain L, Kanoski SE. Ghrelin and Glucagon-Like Peptide-1: A Gut-Brain Axis Battle for Food Reward. Nutrients 2021; 13:977. [PMID: 33803053 PMCID: PMC8002922 DOI: 10.3390/nu13030977] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/14/2021] [Accepted: 03/14/2021] [Indexed: 12/17/2022] Open
Abstract
Eating behaviors are influenced by the reinforcing properties of foods that can favor decisions driven by reward incentives over metabolic needs. These food reward-motivated behaviors are modulated by gut-derived peptides such as ghrelin and glucagon-like peptide-1 (GLP-1) that are well-established to promote or reduce energy intake, respectively. In this review we highlight the antagonizing actions of ghrelin and GLP-1 on various behavioral constructs related to food reward/reinforcement, including reactivity to food cues, conditioned meal anticipation, effort-based food-motivated behaviors, and flavor-nutrient preference and aversion learning. We integrate physiological and behavioral neuroscience studies conducted in both rodents and human to illustrate translational findings of interest for the treatment of obesity or metabolic impairments. Collectively, the literature discussed herein highlights a model where ghrelin and GLP-1 regulate food reward-motivated behaviors via both competing and independent neurobiological and behavioral mechanisms.
Collapse
Affiliation(s)
- Lea Decarie-Spain
- Human & Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA;
| | - Scott E. Kanoski
- Human & Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA;
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
35
|
Appetite problem in cancer patients: Pathophysiology, diagnosis, and treatment. Cancer Treat Res Commun 2021; 27:100336. [PMID: 33607591 DOI: 10.1016/j.ctarc.2021.100336] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 02/01/2021] [Accepted: 02/06/2021] [Indexed: 01/02/2023]
Abstract
AIM This study aims to review the current evidence regarding appetite problem in cancer patients, mainly focusing on pathophysiology, diagnosis, and treatment. INTRODUCTION Anorexia is the common symptom of malnutrition in cancer patients. Recently, the understanding of the pathophysiological mechanism of the appetite problem in cancer patients has been increasing that give impact to rigorous research to find the therapies for improving appetite in cancer patients. DISCUSSION The development of anorexia in cancer patients is a complex process that involves many cytokines, receptors, chemical mediators/substances, hormones, and peptides. Growth and differentiation factor-15 (GDF-15) and toll-like receptor (TLR-4) have recently been found to be implicated in the pathogenesis of anorexia. To help diagnose the appetite problem in cancer patients, several questionnaires can be used, starting from well-known questionnaires such as Functional Assessment of Anorexia Cachexia Therapy (FAACT), Visual Analog Scale (VAS), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ30). Several drugs with different mechanisms of action have been studied to help in improving appetite in cancer patients. New repurposed agents such as anamorelin, mirtazapine, thalidomide, and eicosapentaenoic acid (EPA) have shown a beneficial effect in improving appetite and quality of life in cancer patients, however more phase 3 clinical trial studies is still needed. CONCLUSION The pathophysiology of appetite problems in cancer patients is a complex process that involves many factors. Several drugs that target those factors have been studied, however more phase 3 clinical trial studies are needed to confirm the findings from previous studies.
Collapse
|
36
|
Eren-Yazicioglu CY, Yigit A, Dogruoz RE, Yapici-Eser H. Can GLP-1 Be a Target for Reward System Related Disorders? A Qualitative Synthesis and Systematic Review Analysis of Studies on Palatable Food, Drugs of Abuse, and Alcohol. Front Behav Neurosci 2021; 14:614884. [PMID: 33536884 PMCID: PMC7848227 DOI: 10.3389/fnbeh.2020.614884] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/15/2020] [Indexed: 11/15/2022] Open
Abstract
The role of glucagon-like peptide 1 (GLP-1) in insulin-dependent signaling is well-known; GLP-1 enhances glucose-dependent insulin secretion and lowers blood glucose in diabetes. GLP-1 receptors (GLP-1R) are also widely expressed in the brain, and in addition to its role in neuroprotection, it affects reward pathways. This systematic review aimed to analyze the studies on GLP-1 and reward pathways and its currently identified mechanisms. Methods: “Web of Science” and “Pubmed” were searched to identify relevant studies using GLP-1 as the keyword. Among the identified 26,539 studies, 30 clinical, and 71 preclinical studies were included. Data is presented by grouping rodent studies on palatable food intake, drugs of abuse, and studies on humans focusing on GLP-1 and reward systems. Results: GLP-1Rs are located in reward-related areas, and GLP-1, its agonists, and DPP-IV inhibitors are effective in decreasing palatable food intake, along with reducing cocaine, amphetamine, alcohol, and nicotine use in animals. GLP-1 modulates dopamine levels and glutamatergic neurotransmission, which results in observed behavioral changes. In humans, GLP-1 alters palatable food intake and improves activity deficits in the insula, hypothalamus, and orbitofrontal cortex (OFC). GLP-1 reduces food cravings partially by decreasing activity to the anticipation of food in the left insula of obese patients with diabetes and may inhibit overeating by increasing activity to the consumption of food in the right OFC of obese and left insula of obese with diabetes. Conclusion: Current preclinical studies support the view that GLP-1 can be a target for reward system related disorders. More translational research is needed to evaluate its efficacy on human reward system related disorders.
Collapse
Affiliation(s)
| | - Arya Yigit
- School of Medicine, Koç University, Istanbul, Turkey
| | - Ramazan Efe Dogruoz
- Department of Neuroscience, University of Chicago, Chicago, IL, United States
| | - Hale Yapici-Eser
- Koç University, Research Center for Translational Medicine (KUTTAM), Istanbul, Turkey.,Department of Psychiatry, School of Medicine, Koç University, Istanbul, Turkey
| |
Collapse
|
37
|
García-Cabrerizo R, Carbia C, O Riordan KJ, Schellekens H, Cryan JF. Microbiota-gut-brain axis as a regulator of reward processes. J Neurochem 2021; 157:1495-1524. [PMID: 33368280 DOI: 10.1111/jnc.15284] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/08/2020] [Accepted: 12/21/2020] [Indexed: 12/14/2022]
Abstract
Our gut harbours trillions of microorganisms essential for the maintenance of homeostasis and host physiology in health and disease. In the last decade, there has been a growing interest in understanding the bidirectional pathway of communication between our microbiota and the central nervous system. With regard to reward processes there is accumulating evidence from both animal and human studies that this axis may be a key factor in gating reward valence. Focusing on the mesocorticolimbic pathway, we will discuss how the intestinal microbiota is involved in regulating brain reward functions, both in natural (i.e. eating, social or sexual behaviours) and non-natural reinforcers (drug addiction behaviours including those relevant to alcohol, psychostimulants, opioids and cannabinoids). We will integrate preclinical and clinical evidence suggesting that the microbiota-gut-brain axis could be implicated in the development of disorders associated with alterations in the reward system and how it may be targeted as a promising therapeutic strategy. Cover Image for this issue: https://doi.org/10.1111/jnc.15065.
Collapse
Affiliation(s)
| | - Carina Carbia
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | | | - Harriet Schellekens
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| |
Collapse
|
38
|
Colvin KJ, Killen HS, Kanter MJ, Halperin MC, Engel L, Currie PJ. Brain Site-Specific Inhibitory Effects of the GLP-1 Analogue Exendin-4 on Alcohol Intake and Operant Responding for Palatable Food. Int J Mol Sci 2020; 21:ijms21249710. [PMID: 33352692 PMCID: PMC7766977 DOI: 10.3390/ijms21249710] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/11/2022] Open
Abstract
Approximately 14.4 million Americans are experiencing alcohol use disorder (AUD) and about two-thirds of people who experience drug addiction will relapse, highlighting the need to develop novel and effective treatments. Glucagon-like peptide-1 (GLP-1) is a peptide hormone implicated in the mesocorticolimbic reward system and has become a peptide of interest with respect to its putative inhibitory effects on drug reward. In order to further develop treatments for those diagnosed with AUD, the interplay between GLP-1 receptor signaling and ethanol consumption must be elucidated. In the present study, we investigated the ability of the GLP-1 analogue, exendin-4 (Ex-4), to alter alcohol intake and operant responding for sucrose pellets in order to further understand the role of this compound in mediating reward. We selected multiple sites throughout the prosencephalic and mesencephalic regions of the brain, where we directly administered various doses of Ex-4 to male Sprague Dawley rats. In alcohol investigations, we utilized a two-bottle choice intermittent access protocol. In separate groups of rats, we adopted an operant paradigm in order to examine the effect of Ex-4 on motivated responding for palatable food. Results indicated that GLP-1 receptor signaling effectively suppressed voluntary alcohol intake when injected into the ventral tegmental area (VTA), the accumbens core (NAcC) and shell (NAcS), the dorsomedial hippocampus (DMHipp), and the lateral hypothalamus (LH), which are all structures linked to brain reward mechanisms. The arcuate nucleus (ARcN) and the paraventricular nucleus (PVN) of the hypothalamus were unresponsive, as was the basolateral amygdala (BLA). However, Ex-4 treatment into the ArcN and PVN suppressed operant responding for sucrose pellets. In fact, the VTA, NAcC, NAcS, LH, and the DMHipp all showed comparable suppression of sucrose responding. Overall, our findings suggest that these central structures are implicated in brain reward circuitry, including alcohol and appetitive motivation, which may be mediated by GLP-1 receptor mechanisms. GLP-1, therefore, may play a critical role in modifying addictive behaviors via activation of multiple GLP-1 systems throughout the brain.
Collapse
|
39
|
Lu Z, Chan SW, Tu L, Ngan MP, Rudd JA. GLP-1 receptors are involved in the GLP-1 (7-36) amide-induced modulation of glucose homoeostasis, emesis and feeding in Suncus murinus (house musk shrew). Eur J Pharmacol 2020; 888:173528. [PMID: 32871177 DOI: 10.1016/j.ejphar.2020.173528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 12/25/2022]
Abstract
GLP-1 receptor agonists are used for the treatment of type 2 diabetes but they may reduce appetite and cause nausea and emesis. We investigated if GLP-1 (7-36) amide can modulate glucose homoeostasis, emesis and feeding via an exendin (9-39)-sensitive mechanism in Suncus murinus. The effect of GLP-1 (7-36) amide on glucose homeostasis was examined using an intraperitoneal glucose tolerance test. In conscious fasted animals, food and water consumption and behavior were measured for 1 h following drug administration. c-Fos expression in the brain was measured using immunohistochemistry. GLP-1 (7-36) amide reduced blood glucose levels dose-dependently. Exendin (9-39) did not modify blood glucose levels but suppressed the glucose-lowering effect of GLP-1 (7-36) amide. GLP-1 (7-36) amide inhibited food and water intake, induced emesis and elevated c-Fos expression in the brainstem and hypothalamic nuclei in the brain. Exendin (9-39) antagonised the inhibition of food and water intake and emesis induced by GLP-1 (7-36) amide and the effects on c-Fos expression in the hypothalamus and brainstem, excepting for the bed nucleus of the stria terminalis. These data suggest that the action of GLP-1 (7-36) amide to modulate blood glucose, suppress food and water intake and induce emesis involve GLP-1 receptors in the hypothalamus and brainstem.
Collapse
Affiliation(s)
- Zengbing Lu
- School of Health Sciences, Caritas Institute of Higher Education, Hong Kong SAR, China; School of Biomedical Sciences, Hong Kong SAR, China
| | - Sze Wa Chan
- School of Health Sciences, Caritas Institute of Higher Education, Hong Kong SAR, China.
| | - Longlong Tu
- School of Biomedical Sciences, Hong Kong SAR, China
| | - Man Piu Ngan
- School of Biomedical Sciences, Hong Kong SAR, China
| | - John A Rudd
- School of Biomedical Sciences, Hong Kong SAR, China; Laboratory Animal Services Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
| |
Collapse
|
40
|
Glucagon-like peptide-1 receptors modulate the binge-like feeding induced by µ-opioid receptor stimulation of the nucleus accumbens in the rat. Neuroreport 2020; 31:1283-1288. [PMID: 33165198 DOI: 10.1097/wnr.0000000000001545] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neuropeptides and peptide hormones affect food-directed motivation, in part, through actions on brain regions associated with reward processing. For instance, previous reports have shown that stimulating glucagon-like peptide-1 (GLP-1) receptors in the nucleus accumbens (NAc), an area that directs motivational processes towards food and drugs of abuse, has an anorectic effect. In contrast, µ-opioid receptor activation of the NAc increases feeding, particularly on highly palatable diets. While both neurotransmitters act within the NAc to impact food intake, it is not clear if and how they might interact to affect feeding. Therefore, these experiments tested the effects of NAc injections of the GLP-1 receptor agonist Exendin 4 (EX4) or antagonist Exendin 9 (EX9) on the consumption of a sweetened fat diet, with and without simultaneous µ-opioid receptor stimulation. Male Sprague-Dawley rats (n = 8/group, EX4 or EX9) underwent surgery to place bilateral cannula above the NAc core. After recovery, animals were tested following NAc injections of saline or the µ-opioid agonist [D-Ala, N-MePhe, Gly-ol]-enkephalin (DAMGO) (0.025 µg/side), combined with varying doses of EX4 (0, 0.05, or 0.10 µg/side) or EX9 (0, 2.5, 5.0 µg/side), counterbalanced across 6 testing days. Food and water intake, along with locomotor activity, was monitored for 2 h. Mu-opioid receptor stimulation significantly increased feeding, and this effect was reduced by GLP-1 receptor stimulation. In contrast, GLP-1 antagonism with EX9 altered the dynamics of DAMGO-induced binge-like feeding, extending µ-opioid-induced binging, and increasing food consumption. These findings are the first to demonstrate an interaction between NAc µ-opioid and GLP-1 receptors on palatable food intake.
Collapse
|
41
|
Terrill SJ, Subramanian KS, Lan R, Liu CM, Cortella AM, Noble EE, Kanoski SE. Nucleus accumbens melanin-concentrating hormone signaling promotes feeding in a sex-specific manner. Neuropharmacology 2020; 178:108270. [PMID: 32795460 PMCID: PMC7544677 DOI: 10.1016/j.neuropharm.2020.108270] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/29/2020] [Accepted: 08/03/2020] [Indexed: 01/13/2023]
Abstract
Melanin-concentrating hormone (MCH) is an orexigenic neuropeptide produced in the lateral hypothalamus and zona incerta that increases food intake. The neuronal pathways and behavioral mechanisms mediating the orexigenic effects of MCH are poorly understood, as is the extent to which MCH-mediated feeding outcomes are sex-dependent. Here we investigate the hypothesis that MCH-producing neurons act in the nucleus accumbens shell (ACBsh) to promote feeding behavior and motivation for palatable food in a sex-dependent manner. We utilized ACBsh MCH receptor (MCH1R)-directed pharmacology as well as a dual virus chemogenetic approach to selectively activate MCH neurons that project to the ACBsh. Results reveal that both ACBsh MCH1R activation and activating ACBsh-projecting MCH neurons increase consumption of standard chow and palatable sucrose in male rats without affecting motivated operant responding for sucrose, general activity levels, or anxiety-like behavior. In contrast, food intake was not affected in female rats by either ACBsh MCH1R activation or ACBsh-projecting MCH neuron activation. To determine a mechanism for this sexual dimorphism, we investigated whether the orexigenic effect of ACBsh MCH1R activation is reduced by endogenous estradiol signaling. In ovariectomized female rats on a cyclic regimen of either estradiol (EB) or oil vehicle, ACBsh MCH1R activation increased feeding only in oil-treated rats, suggesting that EB attenuates the ability of ACBsh MCH signaling to promote food intake. Collective results show that MCH ACBsh signaling promotes feeding in an estrogen- and sex-dependent manner, thus identifying novel neurobiological mechanisms through which MCH and female sex hormones interact to influence food intake.
Collapse
Affiliation(s)
- Sarah J Terrill
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA, 90089, United States
| | - Keshav S Subramanian
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA, 90089, United States; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, United States
| | - Rae Lan
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA, 90089, United States
| | - Clarissa M Liu
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA, 90089, United States; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, United States
| | - Alyssa M Cortella
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA, 90089, United States; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, United States
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, 129 Barrow Hall, Athens, GA, 30602, United States.
| | - Scott E Kanoski
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA, 90089, United States; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, United States.
| |
Collapse
|
42
|
Diz-Chaves Y, Herrera-Pérez S, González-Matías LC, Lamas JA, Mallo F. Glucagon-Like Peptide-1 (GLP-1) in the Integration of Neural and Endocrine Responses to Stress. Nutrients 2020; 12:nu12113304. [PMID: 33126672 PMCID: PMC7692797 DOI: 10.3390/nu12113304] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/14/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Glucagon like-peptide 1 (GLP-1) within the brain is produced by a population of preproglucagon neurons located in the caudal nucleus of the solitary tract. These neurons project to the hypothalamus and another forebrain, hindbrain, and mesolimbic brain areas control the autonomic function, feeding, and the motivation to feed or regulate the stress response and the hypothalamic-pituitary-adrenal axis. GLP-1 receptor (GLP-1R) controls both food intake and feeding behavior (hunger-driven feeding, the hedonic value of food, and food motivation). The activation of GLP-1 receptors involves second messenger pathways and ionic events in the autonomic nervous system, which are very relevant to explain the essential central actions of GLP-1 as neuromodulator coordinating food intake in response to a physiological and stress-related stimulus to maintain homeostasis. Alterations in GLP-1 signaling associated with obesity or chronic stress induce the dysregulation of eating behavior. This review summarized the experimental shreds of evidence from studies using GLP-1R agonists to describe the neural and endocrine integration of stress responses and feeding behavior.
Collapse
Affiliation(s)
- Yolanda Diz-Chaves
- CINBIO, Universidade de Vigo, Grupo FB3A, Laboratorio de Endocrinología, 36310 Vigo, Spain;
- Correspondence: (Y.D.-C.); (F.M.); Tel.: +34-(986)-130226 (Y.D.-C.); +34-(986)-812393 (F.M.)
| | - Salvador Herrera-Pérez
- CINBIO, Universidade de Vigo, Grupo FB3B, Laboratorio de Neurociencia, 36310 Vigo, Spain; (S.H.-P.); (J.A.L.)
| | | | - José Antonio Lamas
- CINBIO, Universidade de Vigo, Grupo FB3B, Laboratorio de Neurociencia, 36310 Vigo, Spain; (S.H.-P.); (J.A.L.)
| | - Federico Mallo
- CINBIO, Universidade de Vigo, Grupo FB3A, Laboratorio de Endocrinología, 36310 Vigo, Spain;
- Correspondence: (Y.D.-C.); (F.M.); Tel.: +34-(986)-130226 (Y.D.-C.); +34-(986)-812393 (F.M.)
| |
Collapse
|
43
|
Schwartz AB, Kapur A, Huang Z, Anangi R, Spear JM, Stagg S, Fardone E, Dekan Z, Rosenberg JT, Grant SC, King GF, Mattoussi H, Fadool DA. Olfactory bulb-targeted quantum dot (QD) bioconjugate and Kv1.3 blocking peptide improve metabolic health in obese male mice. J Neurochem 2020; 157:1876-1896. [PMID: 32978815 DOI: 10.1111/jnc.15200] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 01/10/2023]
Abstract
The olfactory system is a driver of feeding behavior, whereby olfactory acuity is modulated by the metabolic state of the individual. The excitability of the major output neurons of the olfactory bulb (OB) can be modulated through targeting a voltage-dependent potassium channel, Kv1.3, which responds to changes in metabolic factors such as insulin, glucose, and glucagon-like peptide-1. Because gene-targeted deletion or inhibition of Kv1.3 in the periphery has been found to increase energy metabolism and decrease body weight, we hypothesized that inhibition of Kv1.3 selectively in the OB could enhance excitability of the output neurons to evoke changes in energy homeostasis. We thereby employed metal-histidine coordination to self-assemble the Kv1.3 inhibitor margatoxin (MgTx) to fluorescent quantum dots (QDMgTx) as a means to label cells in vivo and test changes in neuronal excitability and metabolism when delivered to the OB. Using patch-clamp electrophysiology to measure Kv1.3 properties in heterologously expressed cells and native mitral cells in OB slices, we found that QDMgTx had a fast rate of inhibition, but with a reduced IC50, and increased action potential firing frequency. QDMgTx was capable of labeling cloned Kv1.3 channels but was not visible when delivered to native Kv1.3 in the OB. Diet-induced obese mice were observed to reduce body weight and clear glucose more quickly following osmotic mini-pump delivery of QDMgTx/MgTx to the OB, and following MgTx delivery, they increased the use of fats as fuels (reduced respiratory exchange ratio). These results suggest that enhanced excitability of bulbar output neurons can drive metabolic responses.
Collapse
Affiliation(s)
- Austin B Schwartz
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, FL, USA
| | - Anshika Kapur
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA
| | - Zhenbo Huang
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.,Department of Biological Science, The Florida State University, Tallahassee, FL, USA
| | - Raveendra Anangi
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - John M Spear
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Scott Stagg
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Erminia Fardone
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA
| | - Zolan Dekan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Jens T Rosenberg
- National High Field Magnetic Laboratory, The Florida State University, Tallahassee, FL, USA
| | - Samuel C Grant
- National High Field Magnetic Laboratory, The Florida State University, Tallahassee, FL, USA.,Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, USA
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Hedi Mattoussi
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA
| | - Debra Ann Fadool
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, FL, USA.,Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.,Department of Biological Science, The Florida State University, Tallahassee, FL, USA
| |
Collapse
|
44
|
Distributed amylin receptor signaling and its influence on motivated behavior. Physiol Behav 2020; 222:112958. [DOI: 10.1016/j.physbeh.2020.112958] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/11/2020] [Accepted: 04/30/2020] [Indexed: 12/11/2022]
|
45
|
Grill HJ. A Role for GLP-1 in Treating Hyperphagia and Obesity. Endocrinology 2020; 161:bqaa093. [PMID: 32516384 PMCID: PMC7899438 DOI: 10.1210/endocr/bqaa093] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 02/06/2023]
Abstract
Obesity is a chronic recurring disease whose prevalence has almost tripled over the past 40 years. In individuals with obesity, there is significant increased risk of morbidity and mortality, along with decreased quality of life. Increased obesity prevalence results, at least partly, from the increased global food supply that provides ubiquitous access to tasty, energy-dense foods. These hedonic foods and the nonfood cues that through association become reward predictive cues activate brain appetitive control circuits that drive hyperphagia and weight gain by enhancing food-seeking, motivation, and reward. Behavioral therapy (diet and lifestyle modifications) is the recommended initial treatment for obesity, yet it often fails to achieve meaningful weight loss. Furthermore, those who lose weight regain it over time through biological regulation. The need to effectively treat the pathophysiology of obesity thus centers on biologically based approaches such as bariatric surgery and more recently developed drug therapies. This review highlights neurobiological aspects relevant to obesity causation and treatment by emphasizing the common aspects of the feeding-inhibitory effects of multiple signals. We focus on glucagon like peptide-1 receptor (GLP-1R) signaling as a promising obesity treatment target by discussing the activation of intestinal- and brain-derived GLP-1 and GLP-1R expressing central nervous system circuits resulting from normal eating, bariatric surgery, and GLP-1R agonist drug therapy. Given the increased availability of energy-dense foods and frequent encounters with cues that drive hyperphagia, this review also describes how bariatric surgery and GLP-1R agonist therapies influence food reward and the motivational drive to overeat.
Collapse
Affiliation(s)
- Harvey J Grill
- Institute of Diabetes, Obesity and Metabolism, Graduate Groups for Psychology and Neuroscience, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
46
|
Vestlund J, Jerlhag E. The glucagon-like peptide-1 receptor agonist, exendin-4, reduces sexual interaction behaviors in a brain site-specific manner in sexually naïve male mice. Horm Behav 2020; 124:104778. [PMID: 32450068 DOI: 10.1016/j.yhbeh.2020.104778] [Citation(s) in RCA: 4] [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: 12/16/2019] [Revised: 05/04/2020] [Accepted: 05/18/2020] [Indexed: 01/26/2023]
Abstract
Besides reducing food intake and controlling energy balance, glucagon-like peptide-1 (GLP-1) suppresses the reinforcing properties of palatable foods and addictive drugs. This reduction in reward involves activation of GLP-1 receptors (GLP-1R) within areas processing natural and artificial rewards, including the laterodorsal tegmental area (LDTg), ventral tegmental area (VTA) and nucleus accumbens (NAc) shell. These areas are part of a neurocircuitry mediating reward from addictive drugs and natural rewards including sexual behaviors. The male sexual encounter with a female includes three different stages: a pre-sexual interaction phase with social behaviors, which is followed by a sexual interaction phase with mounting and intromission of the female, and ends with a post-sexual interaction phase characterized by self-grooming behaviors. Albeit GLP-1 modulates reward, the influence of GLP-1R activation on sexual interaction is unknown. Thus, we infused the GLP-1R agonist, exendin-4 (Ex4), into sub-regions of the reward neurocircuitry in sexually naïve male mice and recorded their novel interaction with an estrus female. We found that Ex4 into the LDTg, posterior VTA or NAc shell reduces pre-sexual interaction behaviors and activation of GLP-1R in the LDTg or posterior VTA decreases sexual interaction behaviors. Contrarily, Ex4 infusion into anterior VTA does not influence these behaviors. Furthermore, self-grooming behaviors are not influenced by activation of GLP-1R in the aforementioned areas. These data highlight that activation of GLP-1R in reward-related areas reduces different aspects of the sexual interaction chain and further supports a role of the GLP-1R in social behaviors.
Collapse
Affiliation(s)
- Jesper Vestlund
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
| |
Collapse
|
47
|
Jones S, Hyde A, Davidson TL. Reframing appetitive reinforcement learning and reward valuation as effects mediated by hippocampal-dependent behavioral inhibition. Nutr Res 2020; 79:1-12. [PMID: 32544728 DOI: 10.1016/j.nutres.2020.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/13/2020] [Accepted: 05/04/2020] [Indexed: 02/06/2023]
Abstract
Traditional theories of neuroeconomics focus on reinforcement learning and reward value. We propose here a novel reframing of reinforcement learning and motivation that includes a hippocampal-dependent regulatory mechanism which balances cue-induced behavioral excitation with behavioral inhibition. This mechanism enables interoceptive cues produced by respective food or drug satiety to antagonize the ability of excitatory food- and drug-related environmental cues to retrieve the memories of food and drug reinforcers, thereby suppressing the power of those cues to evoke appetitive behavior. When the operation of this mechanism is impaired, ability of satiety signals to inhibit appetitive behavior is weakened because the relative balance between inhibition and simple excitation is shifted toward increased retrieval of food and drug memories by environmental cues. In the present paper, we (1) describe the associative processes that constitute this mechanism of hippocampal-dependent behavior inhibition; (2) describe how a prevailing obesity-promoting diet and drugs of abuse produce hippocampal pathophysiologies that can selectively impair this inhibitory function; and (3) propose how glucagon-like peptide 1 (GLP-1), an incretin hormone that is recognized as an important satiety signal, may work to protect the hippocampal-dependent inhibition. Our perspective may add to neuroscientific and neuroeconomic analyses of both overeating and drug abuse by outlining the role of hippocampal-dependent memory processes in the control of both food and drug seeking behaviors. In addition, this view suggests that consideration should be given to diet- and drug induced hippocampal pathophysiologies, as potential novel targets for the treatment of dysregulated energy and drug intake.
Collapse
Affiliation(s)
- Sabrina Jones
- Diabetes and Obesity Research Institute, Internal Medicine, Division of Endocrinology, University of Southern California, Los Angeles, CA, United States
| | - Alexia Hyde
- Center for Behavioral Neuroscience, Department of Psychology, American University, Washington, DC, United States
| | - Terry L Davidson
- Center for Behavioral Neuroscience, Department of Psychology, American University, Washington, DC, United States.
| |
Collapse
|
48
|
Wang Q, Zhang X, Leng H, Luan X, Guo F, Sun X, Gao S, Liu X, Qin H, Xu L. Zona incerta projection neurons and GABAergic and GLP-1 mechanisms in the nucleus accumbens are involved in the control of gastric function and food intake. Neuropeptides 2020; 80:102018. [PMID: 32000986 DOI: 10.1016/j.npep.2020.102018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 01/11/2020] [Accepted: 01/13/2020] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Our aim was to explore the effect of γ-aminobutyric acid (GABA) signaling in the nucleus accumbens (NAc) on promoting gastric function and food intake through glucagon-like peptide 1 (GLP-1)-sensitive gastric distension (GD) neurons under the regulatory control of the zona incerta (ZI). METHODS GABA neuronal projections were traced using retrograde tracing following fluorescence immunohistochemistry. An extracellular electrophysiological recording method was used to observe the firing of neurons in the NAc. HPLC was used to quantify the GABA and glutamate levels in the NAc after electrical stimulation of the ZI. Gastric functions including gastric motility and secretion, as well as food intake, were measured after the administration of different concentrations of GABA in the NAc or electrical stimulation of the ZI. RESULTS Some of the GABA-positive neurons arising from the ZI projected to the NAc. Some GABA-A receptor (GABA-AR)-immunoreactive neurons in the NAc were also positive for GLP-1 receptor (GLP-1R) immunoreactivity. The firing of most GLP-1-sensitive GD neurons was decreased by GABA infusion in the NAc. Intra-NAc GABA administration also promoted gastric function and food intake. The responses induced by GABA were partially blocked by the GABA-AR antagonist bicuculline (BIC) and weakened by the GLP-1R antagonist exendin 9-39 (Ex9). Electrical stimulation of the ZI changed the firing patterns of most GLP-1-sensitive GD neurons in the NAc and promoted gastric function and food intake. Furthermore, these excitatory effects induced by electrical stimulation of the ZI were weakened by preadministration of BIC in the NAc. CONCLUSION Retrograde tracing and immunohistochemical staining showed a GABAergic pathway from the ZI to the NAc. GABAergic and GLP-1 mechanisms in the NAc are involved in the control of gastric function and food intake. In addition, the interaction (direct or indirect) between the ZI and these NAc mechanisms is involved in the control of gastric function and food intake.
Collapse
Affiliation(s)
- Qian Wang
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiaoqian Zhang
- Doctoral School of Biomedical Sciences, KU Leuven, B-300 Leuven, Belgium; Family Medicine Department, Qingdao United Family Hospital, Qingdao, Shandong 266001, China
| | - Hui Leng
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiao Luan
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Feifei Guo
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiangrong Sun
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Shengli Gao
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xuehuan Liu
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Hao Qin
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Luo Xu
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China.
| |
Collapse
|
49
|
Graham DL, Durai HH, Trammell TS, Noble BL, Mortlock DP, Galli A, Stanwood GD. A novel mouse model of glucagon-like peptide-1 receptor expression: A look at the brain. J Comp Neurol 2020; 528:2445-2470. [PMID: 32170734 DOI: 10.1002/cne.24905] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 03/07/2020] [Accepted: 03/10/2020] [Indexed: 12/18/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin hormone with a number of functions to maintain energy homeostasis and contribute to motivated behavior, both peripherally and within the central nervous system (CNS). These functions, which include insulin secretion, gastric emptying, satiety, and the hedonic aspects of food and drug intake, are primarily mediated through stimulation of the GLP-1 receptor. While this receptor plays an important role in a variety of physiological outcomes, data regarding its CNS expression has been primarily limited to regional receptor binding and single-label transcript expression studies. We thus developed a bacterial artificial chromosome transgenic mouse, in which expression of a red fluorescent protein (mApple) is driven by the GLP-1R promoter. Using this reporter mouse, we characterized the regional and cellular expression patterns of GLP-1R expressing cells in the CNS, using double-label immunohistochemistry and in situ hybridization. GLP-1R-expressing cells were enriched in several key brain regions and circuits, including the lateral septum, hypothalamus, amygdala, bed nucleus of the stria terminalis, hippocampus, ventral midbrain, periaqueductal gray, and cerebral cortex. In most regions, GLP-1R primarily colocalized with GABAergic neurons, except within some regions such as the hippocampus, where it was co-expressed in glutamatergic neurons. GLP-1R-mApple cells were highly co-expressed with 5-HT3 receptor-containing neurons within the cortex and striatum, as well as with dopamine receptor- and calbindin-expressing cells within the lateral septum, the brain region in which GLP-1R is most highly expressed. In this manuscript, we provide detailed images of GLP-1R-mApple expression and distribution within the brain and characterization of these neurons.
Collapse
Affiliation(s)
- Devon L Graham
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Heather H Durai
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Taylor S Trammell
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Brenda L Noble
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Douglas P Mortlock
- Vanderbilt Genetics Institute and Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Gregg D Stanwood
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida, USA
| |
Collapse
|
50
|
Fortin SM, Lipsky RK, Lhamo R, Chen J, Kim E, Borner T, Schmidt HD, Hayes MR. GABA neurons in the nucleus tractus solitarius express GLP-1 receptors and mediate anorectic effects of liraglutide in rats. Sci Transl Med 2020; 12:eaay8071. [PMID: 32132220 PMCID: PMC7211411 DOI: 10.1126/scitranslmed.aay8071] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/22/2019] [Accepted: 02/13/2020] [Indexed: 01/04/2023]
Abstract
The glucagon-like peptide-1 receptor (GLP-1R) agonist liraglutide is approved for the treatment of obesity; however, there is still much to be learned regarding the neuronal sites of action that underlie its suppressive effects on food intake and body weight. Peripherally administered liraglutide in rats acts in part through central GLP-1Rs in both the hypothalamus and the hindbrain. Here, we extend findings supporting a role for hindbrain GLP-1Rs in mediating the anorectic effects of liraglutide in male rats. To dissociate the contribution of GLP-1Rs in the area postrema (AP) and the nucleus tractus solitarius (NTS), we examined the effects of liraglutide in both NTS AAV-shRNA-driven Glp1r knockdown and AP-lesioned animals. Knockdown of NTS GLP-1Rs, but not surgical lesioning of the AP, attenuated the anorectic and body weight-reducing effects of acutely delivered liraglutide. In addition, NTS c-Fos responses were maintained in AP-lesioned animals. Moreover, NTS Glp1r knockdown was sufficient to attenuate the intake- and body weight-reducing effects of chronic daily administered liraglutide over 3 weeks. Development of improved obesity pharmacotherapies requires an understanding of the cellular phenotypes targeted by GLP-1R agonists. Fluorescence in situ hybridization identified Glp1r transcripts in NTS GABAergic neurons, which when inhibited using chemogenetics, attenuated the food intake- and body weight-reducing effects of liraglutide. This work demonstrates the contribution of NTS GLP-1Rs to the anorectic potential of liraglutide and highlights a phenotypically distinct (GABAergic) population of neurons within the NTS that express the GLP-1R and are involved in the mediation of liraglutide signaling.
Collapse
Affiliation(s)
- Samantha M Fortin
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rachele K Lipsky
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rinzin Lhamo
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jack Chen
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eun Kim
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tito Borner
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Heath D Schmidt
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|