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Ruska Y, Csibi A, Dorogházi B, Szilvásy-Szabó A, Mohácsik P, Környei Z, Dénes Á, Kádár A, Puskár Z, Hrabovszky E, Gereben B, Wittmann G, Fekete C. Topography of the GLP-1/GLP-1 receptor system in the spinal cord of male mice. Sci Rep 2024; 14:14403. [PMID: 38909126 PMCID: PMC11193760 DOI: 10.1038/s41598-024-65442-1] [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: 04/22/2024] [Accepted: 06/20/2024] [Indexed: 06/24/2024] Open
Abstract
Glucagon-like peptide-1 receptor (GLP-1R) agonists are now commonly used to treat type 2 diabetes and obesity. GLP-1R signaling in the spinal cord has been suggested to account for the mild tachycardia caused by GLP-1R agonists, and may also be involved in the therapeutic effects of these drugs. However, the neuroanatomy of the GLP-1/GLP-1R system in the spinal cord is still poorly understood. Here we applied in situ hybridization and immunohistochemistry to characterize this system, and its relation to cholinergic neurons. GLP-1R transcript and protein were expressed in neuronal cell bodies across the gray matter, in matching distribution patterns. GLP-1R-immunolabeling was also robust in dendrites and axons, especially in laminae II-III in the dorsal horn. Cerebrospinal fluid-contacting neurons expressed GLP-1R protein at exceedingly high levels. Only small subpopulations of cholinergic neurons expressed GLP-1R, including a subset of sympathetic preganglionic neurons at the rostral tip of the intermediolateral nucleus. GLP-1 axons innervated all regions where GLP-1R neurons were distributed, except laminae II-III. Scattered preproglucagon (Gcg) mRNA-expressing neurons were identified in the cervical and lumbar enlargements. The results will facilitate further studies on how GLP-1 regulates the sympathetic system and other autonomic and somatic functions via the spinal cord.
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Affiliation(s)
- Yvette Ruska
- Laboratory of Integrative Neuroendocrinology, HUN-REN Institute of Experimental Medicine, Szigony Street 43, Budapest, 1083, Hungary
| | - Andrea Csibi
- Laboratory of Integrative Neuroendocrinology, HUN-REN Institute of Experimental Medicine, Szigony Street 43, Budapest, 1083, Hungary
| | - Beáta Dorogházi
- Laboratory of Molecular Cell Metabolism, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Anett Szilvásy-Szabó
- Laboratory of Integrative Neuroendocrinology, HUN-REN Institute of Experimental Medicine, Szigony Street 43, Budapest, 1083, Hungary
| | - Petra Mohácsik
- Laboratory of Molecular Cell Metabolism, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Zsuzsanna Környei
- "Momentum" Laboratory of Neuroimmunology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Ádám Dénes
- "Momentum" Laboratory of Neuroimmunology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Andrea Kádár
- Laboratory of Integrative Neuroendocrinology, HUN-REN Institute of Experimental Medicine, Szigony Street 43, Budapest, 1083, Hungary
| | - Zita Puskár
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
| | - Erik Hrabovszky
- Laboratory of Reproductive Neurobiology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Balázs Gereben
- Laboratory of Molecular Cell Metabolism, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Gábor Wittmann
- Laboratory of Integrative Neuroendocrinology, HUN-REN Institute of Experimental Medicine, Szigony Street 43, Budapest, 1083, Hungary.
| | - Csaba Fekete
- Laboratory of Integrative Neuroendocrinology, HUN-REN Institute of Experimental Medicine, Szigony Street 43, Budapest, 1083, Hungary.
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2
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Perez-Leighton C, Kerr B, Scherer PE, Baudrand R, Cortés V. The interplay between leptin, glucocorticoids, and GLP1 regulates food intake and feeding behaviour. Biol Rev Camb Philos Soc 2024; 99:653-674. [PMID: 38072002 DOI: 10.1111/brv.13039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 11/21/2023] [Accepted: 12/01/2023] [Indexed: 05/09/2024]
Abstract
Nutritional, endocrine, and neurological signals converge in multiple brain centres to control feeding behaviour and food intake as part of the allostatic regulation of energy balance. Among the several neuroendocrine systems involved, the leptin, glucocorticoid, and glucagon-like peptide 1 (GLP1) systems have been extensively researched. Leptin is at the top hierarchical level since its complete absence is sufficient to trigger severe hyperphagia. Glucocorticoids are key regulators of the energy balance adaptation to stress and their sustained excess leads to excessive adiposity and metabolic perturbations. GLP1 participates in metabolic adaptation to food intake, regulating insulin secretion and satiety by parallel central and peripheral signalling systems. Herein, we review the brain and peripheral targets of these three hormone systems that integrate to regulate food intake, feeding behaviour, and metabolic homeostasis. We examine the functional relationships between leptin, glucocorticoids, and GLP1 at the central and peripheral levels, including the cross-regulation of their circulating levels and their cooperative or antagonistic actions at different brain centres. The pathophysiological roles of these neuroendocrine systems in dysregulated intake are explored in the two extremes of body adiposity - obesity and lipodystrophy - and eating behaviour disorders.
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Affiliation(s)
- Claudio Perez-Leighton
- Departmento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
| | - Bredford Kerr
- Centro de Biología Celular y Biomedicina-CEBICEM, Facultad de Medicina y Ciencia, Universidad San Sebastián, Carmen Sylva 2444, Providencia, Santiago, Chile
| | - Philipp E Scherer
- Touchstone Diabetes Center, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - René Baudrand
- Departmento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
- Centro Translacional de Endocrinología (CETREN), Facultad de Medicina, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
| | - Víctor Cortés
- Departmento de Nutrición, Diabetes y Metabolismo, Facultad de Medicina, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
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3
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Neyens DM, Brenner L, Calkins R, Winzenried ET, Ritter RC, Appleyard SM. CCK-sensitive C fibers activate NTS leptin receptor-expressing neurons via NMDA receptors. Am J Physiol Regul Integr Comp Physiol 2024; 326:R383-R400. [PMID: 38105761 DOI: 10.1152/ajpregu.00238.2022] [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: 09/27/2022] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023]
Abstract
The hormone leptin reduces food intake through actions in the peripheral and central nervous systems, including in the hindbrain nucleus of the solitary tract (NTS). The NTS receives viscerosensory information via vagal afferents, including information from the gastrointestinal tract, which is then relayed to other central nervous system (CNS) sites critical for control of food intake. Leptin receptors (lepRs) are expressed by a subpopulation of NTS neurons, and knockdown of these receptors increases both food intake and body weight. Recently, we demonstrated that leptin increases vagal activation of lepR-expressing neurons via increased NMDA receptor (NMDAR) currents, thereby potentiating vagally evoked firing. Furthermore, chemogenetic activation of these neurons was recently shown to inhibit food intake. However, the vagal inputs these neurons receive had not been characterized. Here we performed whole cell recordings in brain slices taken from lepRCre × floxedTdTomato mice and found that lepR neurons of the NTS are directly activated by monosynaptic inputs from C-type afferents sensitive to the transient receptor potential vanilloid type 1 (TRPV1) agonist capsaicin. CCK administered onto NTS slices stimulated spontaneous glutamate release onto lepR neurons and induced action potential firing, an effect mediated by CCKR1. Interestingly, NMDAR activation contributed to the current carried by spontaneous excitatory postsynaptic currents (EPSCs) and enhanced CCK-induced firing. Peripheral CCK also increased c-fos expression in these neurons, suggesting they are activated by CCK-sensitive vagal afferents in vivo. Our results indicate that the majority of NTS lepR neurons receive direct inputs from CCK-sensitive C vagal-type afferents, with both peripheral and central CCK capable of activating these neurons and NMDARs able to potentiate these effects.
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Affiliation(s)
- Drew M Neyens
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Lynne Brenner
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Rowan Calkins
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Eric T Winzenried
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Robert C Ritter
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Suzanne M Appleyard
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
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4
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Martinez de Morentin PB, Gonzalez JA, Dowsett GKC, Martynova Y, Yeo GSH, Sylantyev S, Heisler LK. A brainstem to hypothalamic arcuate nucleus GABAergic circuit drives feeding. Curr Biol 2024; 34:1646-1656.e4. [PMID: 38518777 DOI: 10.1016/j.cub.2024.02.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 02/05/2024] [Accepted: 02/29/2024] [Indexed: 03/24/2024]
Abstract
The obesity epidemic is principally driven by the consumption of more calories than the body requires. It is therefore essential that the mechanisms underpinning feeding behavior are defined. Neurons within the brainstem dorsal vagal complex (DVC) receive direct information from the digestive system and project to second-order regions in the brain to regulate food intake. Although γ-aminobutyric acid is expressed in the DVC (GABADVC), its function in this region has not been defined. In order to discover the unique gene expression signature of GABADVC cells, we used single-nucleus RNA sequencing (Nuc-seq), and this revealed 19 separate clusters. We next probed the function of GABADVC cells and discovered that the selective activation of GABADVC neurons significantly controls food intake and body weight. Optogenetic interrogation of GABADVC circuitry identified GABADVC → hypothalamic arcuate nucleus (ARC) projections as appetite suppressive without creating aversion. Electrophysiological analysis revealed that GABADVC → ARC stimulation inhibits hunger-promoting neuropeptide Y (NPY) neurons via GABA release. Adopting an intersectional genetics strategy, we clarify that the GABADVC → ARC circuit curbs food intake. These data identify GABADVC as a new modulator of feeding behavior and body weight and a controller of orexigenic NPY neuron activity, thereby providing insight into the neural underpinnings of obesity.
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Affiliation(s)
- Pablo B Martinez de Morentin
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Woodhouse LS2 9JT, UK.
| | - J Antonio Gonzalez
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK
| | - Georgina K C Dowsett
- MRC Metabolic Diseases Unit, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Yuliia Martynova
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK
| | - Giles S H Yeo
- MRC Metabolic Diseases Unit, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Sergiy Sylantyev
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK; Odesa National Mechnikov University, Biological Department, 2 Shampansky Ln., Odesa 65015, Ukraine.
| | - Lora K Heisler
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK
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5
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Lavoie O, Turmel A, Mattoon P, Desrosiers WJ, Plamondon J, Michael NJ, Caron A. Hypothalamic GABAergic Neurons Expressing Cellular Retinoic Acid Binding Protein 1 (CRABP1) Are Sensitive to Metabolic Status and Liraglutide in Male Mice. Neuroendocrinology 2024; 114:681-697. [PMID: 38631315 PMCID: PMC11232952 DOI: 10.1159/000538716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 03/29/2024] [Indexed: 04/19/2024]
Abstract
INTRODUCTION Owing to their privileged anatomical location, neurons of the arcuate nucleus of the hypothalamus (ARC) play critical roles in sensing and responding to metabolic signals such as leptin and glucagon-like peptide 1 (GLP-1). In addition to the well-known proopiomelanocortin (POMC)- and agouti-related peptide (AgRP)-expressing neurons, subpopulations of GABAergic neurons are emerging as key regulators of energy balance. However, the precise identity of these metabolic neurons is still elusive. Here, we identified and characterized the molecular signature of a novel population of GABAergic neurons of the ARC expressing Cellular retinoic acid binding protein 1 (Crabp1). METHODS Using a combination of immunohistochemistry and in situ hybridization techniques, we investigated the expression of Crabp1 across the mouse brain and characterized the molecular identity of Crabp1ARC neurons. We also determined whether Crabp1ARC neurons are sensitive to fasting, leptin, and GLP1R agonism by assessing cFOS immunoreactivity as a marker of neuronal activity. RESULTS Crabp1ARC neurons represent a novel GABAergic neuronal population robustly enriched in the ARC and are distinct from the prototypical melanocortin neurons. Crabp1ARC neurons overlap with three subpopulations of yet uncharacterized ARC neurons expressing Htr3b, Tbx19, and Tmem215. Notably, Crabp1ARC neurons express receptors for metabolic hormones and their activity is modulated by the nutritional state and GLP1R agonism. CONCLUSION Crabp1ARC neurons represent a novel heterogeneous population of GABAergic neurons sensitive to metabolic status.
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Affiliation(s)
- Olivier Lavoie
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
| | - Audrey Turmel
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
| | - Paige Mattoon
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
| | | | | | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
| | - Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
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6
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Skowronski AA, Leibel RL, LeDuc CA. Neurodevelopmental Programming of Adiposity: Contributions to Obesity Risk. Endocr Rev 2024; 45:253-280. [PMID: 37971140 PMCID: PMC10911958 DOI: 10.1210/endrev/bnad031] [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: 06/07/2023] [Revised: 09/29/2023] [Accepted: 10/19/2023] [Indexed: 11/19/2023]
Abstract
This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity. The in utero and early postnatal periods represent critically sensitive developmental windows during which the hormonal and metabolic milieu affects the maturation of the hypothalamus. Maternal hyperglycemia is associated with increased transfer of glucose to the fetus driving fetal hyperinsulinemia. Elevated fetal insulin causes increased adiposity and consequently higher fetal circulating leptin concentration. Mechanistic studies in animal models indicate important roles of leptin and insulin in central and peripheral programming of adiposity, and suggest that optimal concentrations of these hormones are critical during early life. Additionally, the environmental milieu during development may be conveyed to progeny through epigenetic marks and these can potentially be vertically transmitted to subsequent generations. Thus, nutritional and metabolic/endocrine signals during perinatal development can have lifelong (and possibly multigenerational) impacts on offspring body weight regulation.
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Affiliation(s)
- Alicja A Skowronski
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Rudolph L Leibel
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Charles A LeDuc
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
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7
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Woodie LN, Melink LC, Alberto AJ, Burrows M, Fortin SM, Chan CC, Hayes MR, Lazar MA. Hindbrain REV-ERB nuclear receptors regulate sensitivity to diet-induced obesity and brown adipose tissue pathophysiology. Mol Metab 2024; 79:101861. [PMID: 38142970 PMCID: PMC10792761 DOI: 10.1016/j.molmet.2023.101861] [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: 08/26/2023] [Revised: 12/08/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023] Open
Abstract
OBJECTIVE The dorsal vagal complex (DVC) of the hindbrain is a major point of integration for central and peripheral signals that regulate a wide variety of metabolic functions to maintain energy balance. The REV-ERB nuclear receptors are important modulators of molecular metabolism, but their role in the DVC has yet to be established. METHODS Male REV-ERBα/β floxed mice received stereotaxic injections of a Cre expressing virus to the DVC to create the DVC REV-ERBα/β double knockout (DVC RDKO). Control littermates received stereotaxic injections to the DVC of a green fluorescent protein expressing virus. Animals were maintained on a normal chow diet or a 60% high-fat diet to observe the metabolic phenotype arising from DVC RDKO under healthy and metabolically stressed conditions. RESULTS DVC RDKO animals on high-fat diet exhibited increased weight gain compared to control animals maintained on the same diet. Increased weight gain in DVC RDKO animals was associated with decreased basal metabolic rate and dampened signature of brown adipose tissue activity. RDKO decreased gene expression of calcitonin receptor in the DVC and tyrosine hydroxylase in the brown adipose tissue. CONCLUSIONS These results suggest a previously unappreciated role of REV-ERB nuclear receptors in the DVC for maintaining energy balance and metabolic rate potentially through indirect sympathetic outflow to the brown adipose tissue.
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Affiliation(s)
- Lauren N Woodie
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lily C Melink
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ahren J Alberto
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michelle Burrows
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Samantha M Fortin
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Calvin C Chan
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew R Hayes
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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8
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Qiu W, Hutch CR, Wang Y, Wloszek J, Rucker RA, Myers MG, Sandoval D. Multiple NTS neuron populations cumulatively suppress food intake. eLife 2023; 12:e85640. [PMID: 38059498 PMCID: PMC10781422 DOI: 10.7554/elife.85640] [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: 12/16/2022] [Accepted: 12/05/2023] [Indexed: 12/08/2023] Open
Abstract
Several discrete groups of feeding-regulated neurons in the nucleus of the solitary tract (nucleus tractus solitarius; NTS) suppress food intake, including avoidance-promoting neurons that express Cck (NTSCck cells) and distinct Lepr- and Calcr-expressing neurons (NTSLepr and NTSCalcr cells, respectively) that suppress food intake without promoting avoidance. To test potential synergies among these cell groups, we manipulated multiple NTS cell populations simultaneously. We found that activating multiple sets of NTS neurons (e.g. NTSLepr plus NTSCalcr [NTSLC], or NTSLC plus NTSCck [NTSLCK]) suppressed feeding more robustly than activating single populations. While activating groups of cells that include NTSCck neurons promoted conditioned taste avoidance (CTA), NTSLC activation produced no CTA despite abrogating feeding. Thus, the ability to promote CTA formation represents a dominant effect but activating multiple non-aversive populations augments the suppression of food intake without provoking avoidance. Furthermore, silencing multiple NTS neuron groups augmented food intake and body weight to a greater extent than silencing single populations, consistent with the notion that each of these NTS neuron populations plays crucial and cumulative roles in the control of energy balance. We found that silencing NTSLCK neurons failed to blunt the weight-loss response to vertical sleeve gastrectomy (VSG) and that feeding activated many non-NTSLCK neurons, however, suggesting that as-yet undefined NTS cell types must make additional contributions to the restraint of feeding.
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Affiliation(s)
- Weiwei Qiu
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States
| | - Chelsea R Hutch
- Department of Surgery, University of Michigan, Ann Arbor, United States
| | - Yi Wang
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States
| | - Jennifer Wloszek
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, United States
| | - Rachel A Rucker
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, United States
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, United States
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, United States
| | - Darleen Sandoval
- Department of Pediatrics, University of Colorado, Aurora, United States
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Bany Bakar R, Reimann F, Gribble FM. The intestine as an endocrine organ and the role of gut hormones in metabolic regulation. Nat Rev Gastroenterol Hepatol 2023; 20:784-796. [PMID: 37626258 DOI: 10.1038/s41575-023-00830-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/25/2023] [Indexed: 08/27/2023]
Abstract
Gut hormones orchestrate pivotal physiological processes in multiple metabolically active tissues, including the pancreas, liver, adipose tissue, gut and central nervous system, making them attractive therapeutic targets in the treatment of obesity and type 2 diabetes mellitus. Most gut hormones are derived from enteroendocrine cells, but bioactive peptides that are derived from other intestinal epithelial cell types have also been implicated in metabolic regulation and can be considered gut hormones. A deeper understanding of the complex inter-organ crosstalk mediated by the intestinal endocrine system is a prerequisite for designing more effective drugs that are based on or target gut hormones and their receptors, and extending their therapeutic potential beyond obesity and diabetes mellitus. In this Review, we present an overview of gut hormones that are involved in the regulation of metabolism and discuss their action in the gastrointestinal system and beyond.
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Affiliation(s)
- Rula Bany Bakar
- Wellcome Trust-MRC Institute of Metabolic Science Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
| | - Frank Reimann
- Wellcome Trust-MRC Institute of Metabolic Science Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
| | - Fiona M Gribble
- Wellcome Trust-MRC Institute of Metabolic Science Metabolic Research Laboratories, University of Cambridge, Cambridge, UK.
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10
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Ly T, Oh JY, Sivakumar N, Shehata S, La Santa Medina N, Huang H, Liu Z, Fang W, Barnes C, Dundar N, Jarvie BC, Ravi A, Barnhill OK, Li C, Lee GR, Choi J, Jang H, Knight ZA. Sequential appetite suppression by oral and visceral feedback to the brainstem. Nature 2023; 624:130-137. [PMID: 37993711 PMCID: PMC10700140 DOI: 10.1038/s41586-023-06758-2] [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: 10/23/2022] [Accepted: 10/17/2023] [Indexed: 11/24/2023]
Abstract
The termination of a meal is controlled by dedicated neural circuits in the caudal brainstem. A key challenge is to understand how these circuits transform the sensory signals generated during feeding into dynamic control of behaviour. The caudal nucleus of the solitary tract (cNTS) is the first site in the brain where many meal-related signals are sensed and integrated1-4, but how the cNTS processes ingestive feedback during behaviour is unknown. Here we describe how prolactin-releasing hormone (PRLH) and GCG neurons, two principal cNTS cell types that promote non-aversive satiety, are regulated during ingestion. PRLH neurons showed sustained activation by visceral feedback when nutrients were infused into the stomach, but these sustained responses were substantially reduced during oral consumption. Instead, PRLH neurons shifted to a phasic activity pattern that was time-locked to ingestion and linked to the taste of food. Optogenetic manipulations revealed that PRLH neurons control the duration of seconds-timescale feeding bursts, revealing a mechanism by which orosensory signals feed back to restrain the pace of ingestion. By contrast, GCG neurons were activated by mechanical feedback from the gut, tracked the amount of food consumed and promoted satiety that lasted for tens of minutes. These findings reveal that sequential negative feedback signals from the mouth and gut engage distinct circuits in the caudal brainstem, which in turn control elements of feeding behaviour operating on short and long timescales.
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Affiliation(s)
- Truong Ly
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Jun Y Oh
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Nilla Sivakumar
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Sarah Shehata
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Naymalis La Santa Medina
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Heidi Huang
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Zhengya Liu
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Wendy Fang
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Chris Barnes
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Naz Dundar
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Brooke C Jarvie
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - Anagh Ravi
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Olivia K Barnhill
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Chelsea Li
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Grace R Lee
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Jaewon Choi
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Heeun Jang
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
| | - Zachary A Knight
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA.
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA.
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
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11
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Lai TT, Liou CW, Tsai YH, Lin YY, Wu WL. Butterflies in the gut: the interplay between intestinal microbiota and stress. J Biomed Sci 2023; 30:92. [PMID: 38012609 PMCID: PMC10683179 DOI: 10.1186/s12929-023-00984-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 11/06/2023] [Indexed: 11/29/2023] Open
Abstract
Psychological stress is a global issue that affects at least one-third of the population worldwide and increases the risk of numerous psychiatric disorders. Accumulating evidence suggests that the gut and its inhabiting microbes may regulate stress and stress-associated behavioral abnormalities. Hence, the objective of this review is to explore the causal relationships between the gut microbiota, stress, and behavior. Dysbiosis of the microbiome after stress exposure indicated microbial adaption to stressors. Strikingly, the hyperactivated stress signaling found in microbiota-deficient rodents can be normalized by microbiota-based treatments, suggesting that gut microbiota can actively modify the stress response. Microbiota can regulate stress response via intestinal glucocorticoids or autonomic nervous system. Several studies suggest that gut bacteria are involved in the direct modulation of steroid synthesis and metabolism. This review provides recent discoveries on the pathways by which gut microbes affect stress signaling and brain circuits and ultimately impact the host's complex behavior.
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Affiliation(s)
- Tzu-Ting Lai
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Chia-Wei Liou
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yu-Hsuan Tsai
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yuan-Yuan Lin
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Wei-Li Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
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12
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Liu Z, Xiao T, Liu H. Leptin signaling and its central role in energy homeostasis. Front Neurosci 2023; 17:1238528. [PMID: 38027481 PMCID: PMC10644276 DOI: 10.3389/fnins.2023.1238528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Leptin plays a critical role in regulating appetite, energy expenditure and body weight, making it a key factor in maintaining a healthy balance. Despite numerous efforts to develop therapeutic interventions targeting leptin signaling, their effectiveness has been limited, underscoring the importance of gaining a better understanding of the mechanisms through which leptin exerts its functions. While the hypothalamus is widely recognized as the primary site responsible for the appetite-suppressing and weight-reducing effects of leptin, other brain regions have also been increasingly investigated for their involvement in mediating leptin's action. In this review, we summarize leptin signaling pathways and the neural networks that mediate the effects of leptin, with a specific emphasis on energy homeostasis.
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Affiliation(s)
- Zhaoxun Liu
- Nursing Department, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Emergency, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Tao Xiao
- Nursing Department, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hailan Liu
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
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13
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Sun L, Zhu M, Wang M, Hao Y, Hao Y, Jing X, Yu H, Shi Y, Zhang X, Wang S, Yuan F, Yuan XS. Whole-brain monosynaptic inputs and outputs of leptin receptor b neurons of the nucleus tractus solitarii in mice. Brain Res Bull 2023; 201:110693. [PMID: 37348822 DOI: 10.1016/j.brainresbull.2023.110693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/13/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
The nucleus tractus solitarii (NTS) is the primary central station that integrates visceral afferent information and regulates respiratory, gastrointestinal, cardiovascular, and other physiological functions. Leptin receptor b (LepRb)-expressing neurons of the NTS (NTSLepRb neurons) are implicated in central respiration regulation, respiratory facilitation, and respiratory drive enhancement. Furthermore, LepRb dysfunction is involved in obesity, insulin resistance, and sleep-disordered breathing. However, the monosynaptic inputs and outputs of NTSLepRb neurons in whole-brain mapping remain to be elucidated. Therefore, the exploration of its whole-brain connection system may provide strong support for comprehensively understanding the physiological and pathological functions of NTSLepRb neurons. In the present study, we used a cell type-specific, modified rabies virus and adeno-associated virus with the Cre-loxp system to map monosynaptic inputs and outputs of NTSLepRb neurons in LepRb-Cre mice. The results showed that NTSLepRb neurons received inputs from 48 nuclei in the whole brain from five brain regions, including especially the medulla. We found that NTSLepRb neurons received inputs from nuclei associated with respiration, such as the pre-Bötzinger complex, ambiguus nucleus, and parabrachial nucleus. Interestingly, some brain areas related to cardiovascular regulation-i.e., the ventrolateral periaqueductal gray and locus coeruleus-also sent a small number of inputs to NTSLepRb neurons. In addition, anterograde tracing results demonstrated that NTSLepRb neurons sent efferent projections to 15 nuclei, including the dorsomedial hypothalamic nucleus and arcuate hypothalamic nucleus, which are involved in regulation of energy metabolism and feeding behaviors. Quantitative statistical analysis revealed that the inputs of the whole brain to NTSLepRb neurons were significantly greater than the outputs. Our study comprehensively revealed neuronal connections of NTSLepRb neurons in the whole brain and provided a neuroanatomical basis for further research on physiological and pathological functions of NTSLepRb neurons.
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Affiliation(s)
- Lu Sun
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China; Department of Anatomy and Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Mengchu Zhu
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China; Department of Anatomy and Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Meng Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China
| | - Yinchao Hao
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China
| | - Yaxin Hao
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China
| | - Xinyi Jing
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China
| | - Hongxiao Yu
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China; Hebei Key Laboratory of Neurophysiology, Shijiazhuang 050017, Hebei Province, China
| | - Yishuo Shi
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China
| | - Xiang Zhang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China
| | - Sheng Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China; Hebei Key Laboratory of Neurophysiology, Shijiazhuang 050017, Hebei Province, China
| | - Fang Yuan
- Department of Neurobiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China; Hebei Key Laboratory of Neurophysiology, Shijiazhuang 050017, Hebei Province, China.
| | - Xiang Shan Yuan
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.
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14
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Haspula D, Cui Z. Neurochemical Basis of Inter-Organ Crosstalk in Health and Obesity: Focus on the Hypothalamus and the Brainstem. Cells 2023; 12:1801. [PMID: 37443835 PMCID: PMC10341274 DOI: 10.3390/cells12131801] [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: 05/15/2023] [Revised: 06/23/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Precise neural regulation is required for maintenance of energy homeostasis. Essential to this are the hypothalamic and brainstem nuclei which are located adjacent and supra-adjacent to the circumventricular organs. They comprise multiple distinct neuronal populations which receive inputs not only from other brain regions, but also from circulating signals such as hormones, nutrients, metabolites and postprandial signals. Hence, they are ideally placed to exert a multi-tier control over metabolism. The neuronal sub-populations present in these key metabolically relevant nuclei regulate various facets of energy balance which includes appetite/satiety control, substrate utilization by peripheral organs and glucose homeostasis. In situations of heightened energy demand or excess, they maintain energy homeostasis by restoring the balance between energy intake and expenditure. While research on the metabolic role of the central nervous system has progressed rapidly, the neural circuitry and molecular mechanisms involved in regulating distinct metabolic functions have only gained traction in the last few decades. The focus of this review is to provide an updated summary of the mechanisms by which the various neuronal subpopulations, mainly located in the hypothalamus and the brainstem, regulate key metabolic functions.
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Affiliation(s)
- Dhanush Haspula
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Zhenzhong Cui
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA;
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15
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Shamardl HAMA, Ibrahim NA, Merzeban DH, Elamir AM, Golam RM, Elsayed AM. Resveratrol and Dulaglutide ameliorate adiposity and liver dysfunction in rats with diet-induced metabolic syndrome: Role of SIRT-1 / adipokines / PPARγ and IGF-1. Daru 2023:10.1007/s40199-023-00458-y. [PMID: 36991247 DOI: 10.1007/s40199-023-00458-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 03/05/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND Adiposity and non-alcoholic fatty liver disease (NAFLD) are common characteristics of metabolic syndrome (MS). Understanding the underlying pathogenesis is crucial for the development of new remedies. Resveratrol controls obesity and glycemic disorders in patients with MS. OBJECTIVES This study aimed to evaluate the effect of resveratrol and dulaglutide on adipose tissues and liver in rats with MS, declaring their possible mechanisms. METHODS Rats allocated as Control, MS (induced by a high fat/ high sucrose diet for eight weeks), MS + Resveratrol (30 mg/kg/day orally), and MS + Dulaglutide (0.6 mg/kg twice weekly SC); drugs administration was in the last four weeks. Serum biochemical measurements were done. Liver and visceral fat were processed for biochemistry, histopathology, and immunohistochemistry. RESULTS MS results demonstrated significantly increased systolic and diastolic blood pressure, anthropometric measurements, serum levels of alanine aminotransferase (ALT), glycemic indices, and lipids with decreased HDL-C. Tissue levels of leptin, malondialdehyde (MDA), and TNF-α reactivity significantly increased. Expression of adiponectin, PPARγ, and insulin growth factor-1 (IGF-1) decreased. Also, Western blotting mRNA gene expression of liver SIRT-1 was down-regulated. Resveratrol and dulaglutide significantly and effectively reversed MS complexity, ameliorating all findings, particularly NAFLD and adiposity-induced inflammation. Resveratrol significantly appears superior to dulaglutide regarding the effects on hemodynamics, lipids, adipokines, IGF-1 levels, and adipocyte size. Parallel, dulaglutide has more influence on glycemic control. CONCLUSION Protective effects of the drugs may be through correlations between SIRT-1/adipokines/IGF-1 and PPARγ, improving the cross-talk between insulin resistance, obesity markers, liver dysfunction, and TNF-α. Promising multi-beneficial therapies of resveratrol or dulaglutide in MS are recommended clinically for this purpose. Showing the Experimental Design.
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Affiliation(s)
| | - Noha A Ibrahim
- Histology and Cell Biology Department, Faculty of Medicine, Fayoum University, Fayoum, 19052, Egypt
| | - Dina H Merzeban
- Medical Physiology DepartmentFaculty of Medicine, Fayoum University, Fayoum, 19052, Egypt
| | - Azza M Elamir
- Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Fayoum University, Fayoum, 19052, Egypt
| | - Rehab M Golam
- Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Fayoum University, Fayoum, 19052, Egypt
| | - Asmaa M Elsayed
- Histology and Cell Biology Department, Faculty of Medicine, Fayoum University, Fayoum, 19052, Egypt
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16
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Lavoie O, Michael NJ, Caron A. A critical update on the leptin-melanocortin system. J Neurochem 2023; 165:467-486. [PMID: 36648204 DOI: 10.1111/jnc.15765] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/25/2022] [Accepted: 01/09/2023] [Indexed: 01/18/2023]
Abstract
The discovery of leptin in 1994 was an "eureka moment" in the field of neurometabolism that provided new opportunities to better understand the central control of energy balance and glucose metabolism. Rapidly, a prevalent model in the field emerged that pro-opiomelanocortin (POMC) neurons were key in promoting leptin's anorexigenic effects and that the arcuate nucleus of the hypothalamus (ARC) was a key region for the regulation of energy homeostasis. While this model inspired many important discoveries, a growing body of literature indicates that this model is now outdated. In this review, we re-evaluate the hypothalamic leptin-melanocortin model in light of recent advances that directly tackle previous assumptions, with a particular focus on the ARC. We discuss how segregated and heterogeneous these neurons are, and examine how the development of modern approaches allowing spatiotemporal, intersectional, and chemogenetic manipulations of melanocortin neurons has allowed a better definition of the complexity of the leptin-melanocortin system. We review the importance of leptin in regulating glucose homeostasis, but not food intake, through direct actions on ARC POMC neurons. We further highlight how non-POMC, GABAergic neurons mediate leptin's direct effects on energy balance and influence POMC neurons.
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Affiliation(s)
- Olivier Lavoie
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada
| | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada
| | - Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada.,Montreal Diabetes Research Center, Montreal, Quebec, Canada
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17
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Zheng H, López-Ferreras L, Krieger JP, Fasul S, Cea Salazar V, Valderrama Pena N, Skibicka KP, Rinaman L. A Cre-driver rat model for anatomical and functional analysis of glucagon (Gcg)-expressing cells in the brain and periphery. Mol Metab 2022; 66:101631. [PMID: 36368622 PMCID: PMC9677222 DOI: 10.1016/j.molmet.2022.101631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE The glucagon gene (Gcg) encodes preproglucagon, which is cleaved to form glucagon-like peptide 1 (GLP1) and other mature signaling molecules implicated in metabolic functions. To date there are no transgenic rat models available for precise manipulation of GLP1-expressing cells in the brain and periphery. METHODS To visualize and manipulate Gcg-expressing cells in rats, CRISPR/Cas9 was used to express iCre under control of the Gcg promoter. Gcg-Cre rats were bred with tdTomato reporter rats to tag Gcg-expressing cells. Cre-dependent AAVs and RNAscope in situ hybridization were used to evaluate the specificity of iCre expression by GLP1 neurons in the caudal nucleus of the solitary tract (cNTS) and intermediate reticular nucleus (IRt), and by intestinal and pancreatic secretory cells. Food intake was assessed in heterozygous (Het) Gcg-Cre rats after chemogenetic stimulation of cNTS GLP1 neurons expressing an excitatory DREADD. RESULTS While genotype has minimal effect on body weight or composition in chow-fed Gcg-Cre rats, homozygous (Homo) rats have lower plasma glucose levels. In neonatal and adult Gcg-Cre/tdTom rats, reporter-labeled cells are present in the cNTS and IRt, and in additional brain regions (e.g., basolateral amygdala, piriform cortex) that lack detectable Gcg mRNA in adults but display transient developmental or persistently low Gcg expression. Compared to wildtype (WT) rats, hindbrain Gcg mRNA and GLP1 protein in brain and plasma are markedly reduced in Homo Gcg-Cre rats. Chemogenetic stimulation of cNTS GLP1 neurons reduced overnight chow intake in males but not females, the effect in males was blocked by antagonism of central GLP1 receptors, and hypophagia was enhanced when combined with a subthreshold dose of cholecystokinin-8 to stimulate gastrointestinal vagal afferents. CONCLUSIONS Gcg-Cre rats are a novel and valuable experimental tool for analyzing the development, anatomy, and function of Gcg-expressing cells in the brain and periphery. In addition, Homo Gcg-Cre rats are a unique model for assessing the role of Gcg-encoded proteins in glucose homeostasis and energy metabolism.
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Affiliation(s)
- Huiyuan Zheng
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Lorena López-Ferreras
- Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Jean-Phillipe Krieger
- Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Stephen Fasul
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Valentina Cea Salazar
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Natalia Valderrama Pena
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Karolina P. Skibicka
- Department of Nutritional Sciences, College of Health and Human Development, Huck Institute, The Pennsylvania State University, University Park, PA, USA,Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden,Corresponding author. Department of Nutritional Sciences, Pennsylvania State University, 204 Chandlee Lab, University Park, PA 16802, USA
| | - Linda Rinaman
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA,Corresponding author. Department of Psychology, Program in Neuroscience, Florida State University, 1107 W. Call Street, Tallahassee, FL 32306, USA.
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18
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Shao Y, Tian J, Yang Y, Hu Y, Zhu Y, Shu Q. Identification of key genes and pathways revealing the central regulatory mechanism of brain-derived glucagon-like peptide-1 on obesity using bioinformatics analysis. Front Neurosci 2022; 16:931161. [PMID: 35992905 PMCID: PMC9389235 DOI: 10.3389/fnins.2022.931161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/07/2022] [Indexed: 12/01/2022] Open
Abstract
Objective Central glucagon-like peptide-1 (GLP-1) is a target in treating obesity due to its effect on suppressing appetite, but the possible downstream key genes that GLP-1 regulated have not been studied in depth. This study intends to screen out the downstream feeding regulation genes of central GLP-1 neurons through bioinformatics analysis and verify them by chemical genetics, which may provide insights for future research. Materials and methods GSE135862 genetic expression profiles were extracted from the Gene Expression Omnibus (GEO) database. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were carried out. STRING database and Cytoscape software were used to map the protein-protein interaction (PPI) network of the differentially expressed genes (DEGs). After bioinformatics analysis, we applied chemogenetic methods to modulate the activities of GLP-1 neurons in the nucleus tractus solitarius (NTS) and observed the alterations of screened differential genes and their protein expressions in the hypothalamus under different excitatory conditions of GLP-1 neurons. Results A total of 49 DEGs were discovered, including 38 downregulated genes and 11 upregulated genes. The two genes with the highest expression scores were biglycan (Bgn) and mitogen-activated protein kinase activated protein kinase 3 (Mapkapk3). The results of GO analysis showed that there were 10 molecular functions of differential genes. Differential genes were mainly localized in seven regions around the cells, and enriched in 10 biology processes. The results of the KEGG signaling pathway enrichment analysis showed that differential genes played an important role in seven pathways. The top 15 genes selected according to the Cytoscape software included Bgn and Mapkapk3. Chemogenetic activation of GLP-1 in NTS induced a decrease in food intake and body mass, while chemogenetic inhibition induced the opposite effect. The gene and protein expression of GLP-1 were upregulated in NTS when activated by chemogenetics. In addition, the expression of Bgn was upregulated and that of Mapkapk3 was downregulated in the hypothalamus. Conclusion Our data showed that GLP-1 could modulate the protein expression of Bgn and Mapkapk3. Our findings elucidated the regulatory network in GLP-1 to obesity and might provide a novel diagnostic and therapeutic target for obesity.
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Affiliation(s)
- Yuwei Shao
- Department of Rehabilitation, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jun Tian
- Department of Rehabilitation, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yanan Yang
- Department of Traditional Chinese Medicine, China Resources Wugang General Hospital, Wuhan, China
| | - Yan Hu
- Department of Rehabilitation, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Ye Zhu
- College of Health Sciences, Wuhan Sports University, Wuhan, China
| | - Qing Shu
- Department of Rehabilitation, Zhongnan Hospital of Wuhan University, Wuhan, China
- *Correspondence: Qing Shu,
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19
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Cheng W, Gordian D, Ludwig MQ, Pers TH, Seeley RJ, Myers MG. Hindbrain circuits in the control of eating behaviour and energy balance. Nat Metab 2022; 4:826-835. [PMID: 35879458 DOI: 10.1038/s42255-022-00606-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/13/2022] [Indexed: 01/15/2023]
Abstract
Body weight and adiposity represent biologically controlled parameters that are influenced by a combination of genetic, developmental and environmental variables. Although the hypothalamus plays a crucial role in matching caloric intake with energy expenditure to achieve a stable body weight, it is now recognized that neuronal circuits in the hindbrain not only serve to produce nausea and to terminate feeding in response to food consumption or during pathological states, but also contribute to the long-term control of body weight. Additionally, recent work has identified hindbrain neurons that are capable of suppressing food intake without producing aversive responses like those associated with nausea. Here we review recent advances in our understanding of the hindbrain neurons that control feeding, particularly those located in the area postrema and the nucleus tractus solitarius. We frame this information in the context of new atlases of hindbrain neuronal populations and develop a model of the hindbrain circuits that control food intake and energy balance, suggesting important areas for additional research.
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Affiliation(s)
- Wenwen Cheng
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Desiree Gordian
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA
| | - Mette Q Ludwig
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Tune H Pers
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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20
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Holt MK. The ins and outs of the caudal nucleus of the solitary tract: An overview of cellular populations and anatomical connections. J Neuroendocrinol 2022; 34:e13132. [PMID: 35509189 PMCID: PMC9286632 DOI: 10.1111/jne.13132] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
Abstract
The body and brain are in constant two-way communication. Driving this communication is a region in the lower brainstem: the dorsal vagal complex. Within the dorsal vagal complex, the caudal nucleus of the solitary tract (cNTS) is a major first stop for incoming information from the body to the brain carried by the vagus nerve. The anatomy of this region makes it ideally positioned to respond to signals of change in both emotional and bodily states. In turn, the cNTS controls the activity of regions throughout the brain that are involved in the control of both behaviour and physiology. This review is intended to help anyone with an interest in the cNTS. First, I provide an overview of the architecture of the cNTS and outline the wide range of neurotransmitters expressed in subsets of neurons in the cNTS. Next, in detail, I discuss the known inputs and outputs of the cNTS and briefly highlight what is known regarding the neurochemical makeup and function of those connections. Then, I discuss one group of cNTS neurons: glucagon-like peptide-1 (GLP-1)-expressing neurons. GLP-1 neurons serve as a good example of a group of cNTS neurons, which receive input from varied sources and have the ability to modulate both behaviour and physiology. Finally, I consider what we might learn about other cNTS neurons from our study of GLP-1 neurons and why it is important to remember that the manipulation of molecularly defined subsets of cNTS neurons is likely to affect physiology and behaviours beyond those monitored in individual experiments.
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Affiliation(s)
- Marie K. Holt
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUK
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21
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Tu L, Fukuda M, Tong Q, Xu Y. The ventromedial hypothalamic nucleus: watchdog of whole-body glucose homeostasis. Cell Biosci 2022; 12:71. [PMID: 35619170 PMCID: PMC9134642 DOI: 10.1186/s13578-022-00799-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/25/2022] [Indexed: 02/06/2023] Open
Abstract
The brain, particularly the ventromedial hypothalamic nucleus (VMH), has been long known for its involvement in glucose sensing and whole-body glucose homeostasis. However, it is still not fully understood how the brain detects and responds to the changes in the circulating glucose levels, as well as brain-body coordinated control of glucose homeostasis. In this review, we address the growing evidence implicating the brain in glucose homeostasis, especially in the contexts of hypoglycemia and diabetes. In addition to neurons, we emphasize the potential roles played by non-neuronal cells, as well as extracellular matrix in the hypothalamus in whole-body glucose homeostasis. Further, we review the ionic mechanisms by which glucose-sensing neurons sense fluctuations of ambient glucose levels. We also introduce the significant implications of heterogeneous neurons in the VMH upon glucose sensing and whole-body glucose homeostasis, in which sex difference is also addressed. Meanwhile, research gaps have also been identified, which necessities further mechanistic studies in future.
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Affiliation(s)
- Longlong Tu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA
| | - Makoto Fukuda
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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22
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Global transcriptomic characterization of T cells in individuals with chronic HIV-1 infection. Cell Discov 2022; 8:29. [PMID: 35351857 PMCID: PMC8964811 DOI: 10.1038/s41421-021-00367-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 12/08/2021] [Indexed: 12/14/2022] Open
Abstract
To obtain a comprehensive scenario of T cell profiles and synergistic immune responses, we performed single-cell RNA sequencing (scRNA-seq) on the peripheral T cells of 14 individuals with chronic human immunodeficiency virus 1 (HIV-1) infection, including nine treatment-naive (TP) and eight antiretroviral therapy (ART) participants (of whom three were paired with TP cases), and compared the results with four healthy donors (HD). Through analyzing the transcriptional profiles of CD4+ and CD8+ T cells, coupled with assembled T cell receptor sequences, we observed the significant loss of naive T cells, prolonged inflammation, and increased response to interferon-α in TP individuals, which could be partially restored by ART. Interestingly, we revealed that CD4+ and CD8+ Effector-GNLY clusters were expanded in TP cases, and persistently increased in ART individuals where they were typically correlated with poor immune restoration. This transcriptional dataset enables a deeper understanding of the pathogenesis of HIV-1 infection and is also a rich resource for developing novel immune targeted therapeutic strategies.
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23
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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.
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Affiliation(s)
- Daniel J Drucker
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada.
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24
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Kabahizi A, Wallace B, Lieu L, Chau D, Dong Y, Hwang ES, Williams KW. Glucagon-like peptide-1 (GLP-1) signalling in the brain: From neural circuits and metabolism to therapeutics. Br J Pharmacol 2021; 179:600-624. [PMID: 34519026 PMCID: PMC8820188 DOI: 10.1111/bph.15682] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 12/18/2022] Open
Abstract
Glucagon‐like‐peptide‐1 (GLP‐1) derived from gut enteroendocrine cells and a discrete population of neurons in the caudal medulla acts through humoral and neural pathways to regulate satiety, gastric motility and pancreatic endocrine function. These physiological attributes contribute to GLP‐1 having a potent therapeutic action in glycaemic regulation and chronic weight management. In this review, we provide an overview of the neural circuits targeted by endogenous versus exogenous GLP‐1 and related drugs. We also highlight candidate subpopulations of neurons and cellular mechanisms responsible for the acute and chronic effects of GLP‐1 and GLP‐1 receptor agonists on energy balance and glucose metabolism. Finally, we present potential future directions to translate these findings towards the development of effective therapies for treatment of metabolic disease.
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Affiliation(s)
- Anita Kabahizi
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Briana Wallace
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Linh Lieu
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Dominic Chau
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Yanbin Dong
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Eun-Sang Hwang
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Kevin W Williams
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
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25
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Cheng W, Ndoka E, Maung JN, Pan W, Rupp AC, Rhodes CJ, Olson DP, Myers MG. NTS Prlh overcomes orexigenic stimuli and ameliorates dietary and genetic forms of obesity. Nat Commun 2021; 12:5175. [PMID: 34462445 PMCID: PMC8405610 DOI: 10.1038/s41467-021-25525-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/11/2021] [Indexed: 11/09/2022] Open
Abstract
Calcitonin receptor (Calcr)-expressing neurons of the nucleus tractus solitarius (NTS; CalcrNTS cells) contribute to the long-term control of food intake and body weight. Here, we show that Prlh-expressing NTS (PrlhNTS) neurons represent a subset of CalcrNTS cells and that Prlh expression in these cells restrains body weight gain in the face of high fat diet challenge in mice. To understand the relationship of PrlhNTS cells to hypothalamic feeding circuits, we determined the ability of PrlhNTS-mediated signals to overcome enforced activation of AgRP neurons. We found that PrlhNTS neuron activation and Prlh overexpression in PrlhNTS cells abrogates AgRP neuron-driven hyperphagia and ameliorates the obesity of mice deficient in melanocortin signaling or leptin. Thus, enhancing Prlh-mediated neurotransmission from the NTS dampens hypothalamically-driven hyperphagia and obesity, demonstrating that NTS-mediated signals can override the effects of orexigenic hypothalamic signals on long-term energy balance. Calcitonin receptor-expressing neurons of the nucleus tractus solitarius contribute to long-term control of food intake and body weight. The authors show that a subset of these cells expresses Prlh and that enhancing Prlh-mediated neurotransmission from the NTS dampens hypothalamically-driven hyperphagia and obesity in mice.
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Affiliation(s)
- Wenwen Cheng
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
| | - Ermelinda Ndoka
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Jessica N Maung
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Warren Pan
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Alan C Rupp
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Christopher J Rhodes
- Research and Early Development, Cardiovascular, Renal, and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - David P Olson
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.,Division of Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA. .,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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26
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Holt MK. Mind affects matter: Hindbrain GLP1 neurons link stress, physiology and behaviour. Exp Physiol 2021; 106:1853-1862. [PMID: 34302307 DOI: 10.1113/ep089445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/19/2021] [Indexed: 12/12/2022]
Abstract
NEW FINDINGS What is the topic of this review? This Lecture covers the role of caudal brainstem GLP1 neurons in acute and chronic stress responses. What advances does it highlight? This Lecture focuses on the recent advances in our understanding of GLP1 neurons and their physiological role in many aspects of stress. Particular focus is given to the recent elucidation, in part, of the anatomical basis for recruitment of GLP1 neurons in response to acute stress. Finally, the potential, but at this time somewhat speculative, role of GLP1 neurons in chronic stress is discussed. ABSTRACT The brain responds rapidly to stressful stimuli by increasing sympathetic outflow, activating the hypothalamic-pituitary-adrenal axis and eliciting avoidance behaviours to limit risks to safety. Stress responses are adaptive and essential but can become maladaptive when the stress is chronic, causing autonomic imbalance, hypothalamic-pituitary-adrenal axis hyper-reactivity and a state of hypervigilance. Ultimately, this contributes to the development of cardiovascular disease and affective disorders, including major depression and anxiety. Stress responses are often thought to be driven mainly by forebrain areas; however, the brainstem nucleus of the solitary tract (NTS) is ideally located to control both autonomic outflow and behaviour in response to stress. Here, I review the preclinical evidence that the NTS and its resident glucagon-like peptide-1 (GLP1)-expressing neurons are prominent mediators of stress responses. This Lecture introduces the reader to the idea of good and bad stress and outlines the types of stress that engage the NTS and GLP1 neurons. I describe in particular detail the recent studies by myself and others aimed at mapping sources of synaptic inputs to GLP1 neurons and consider the implications for our understanding of the role of GLP1 neurons in stress. This is followed by a discussion of the contribution of brain GLP1 and GLP1 neurons to behavioural and physiological stress responses. The evidence reviewed highlights a potentially prominent role for GLP1 neurons in the response of the brain to acute stress and reveals important unanswered questions regarding their role in chronic stress.
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Affiliation(s)
- Marie K Holt
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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27
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Yu H, Shi L, Chen J, Jun S, Hao Y, Wang S, Fu C, Zhang X, Lu H, Wang S, Yuan F. A Neural Circuit Mechanism Controlling Breathing by Leptin in the Nucleus Tractus Solitarii. Neurosci Bull 2021; 38:149-165. [PMID: 34212297 PMCID: PMC8821766 DOI: 10.1007/s12264-021-00742-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/07/2021] [Indexed: 02/03/2023] Open
Abstract
Leptin, an adipocyte-derived peptide hormone, has been shown to facilitate breathing. However, the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood. The present study aimed to address whether neurons expressing leptin receptor b (LepRb) in the nucleus tractus solitarii (NTS) contribute to respiratory control. Both chemogenetic and optogenetic stimulation of LepRb-expressing NTS (NTSLepRb) neurons notably activated breathing. Moreover, stimulation of NTSLepRb neurons projecting to the lateral parabrachial nucleus (LPBN) not only remarkably increased basal ventilation to a level similar to that of the stimulation of all NTSLepRb neurons, but also activated LPBN neurons projecting to the preBötzinger complex (preBötC). By contrast, ablation of NTSLepRb neurons projecting to the LPBN notably eliminated the enhanced respiratory effect induced by NTSLepRb neuron stimulation. In brainstem slices, bath application of leptin rapidly depolarized the membrane potential, increased the spontaneous firing rate, and accelerated the Ca2+ transients in most NTSLepRb neurons. Therefore, leptin potentiates breathing in the NTS most likely via an NTS-LPBN-preBötC circuit.
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Affiliation(s)
- Hongxiao Yu
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Luo Shi
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Jinting Chen
- grid.256883.20000 0004 1760 8442Core Facilities and Centers, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Shirui Jun
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Yinchao Hao
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Shuang Wang
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Congrui Fu
- grid.256883.20000 0004 1760 8442School of Nursing, Hebei Medical University, Shijiazhuang, 050000 Hebei China
| | - Xiang Zhang
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Haiyan Lu
- grid.256883.20000 0004 1760 8442Department of Orthodontics, College of Stomatology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Sheng Wang
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China ,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, 050017 Hebei China
| | - Fang Yuan
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China ,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, 050017 Hebei China
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28
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Myers MG, Affinati AH, Richardson N, Schwartz MW. Central nervous system regulation of organismal energy and glucose homeostasis. Nat Metab 2021; 3:737-750. [PMID: 34158655 DOI: 10.1038/s42255-021-00408-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/12/2021] [Indexed: 02/05/2023]
Abstract
Growing evidence implicates the brain in the regulation of both immediate fuel availability (for example, circulating glucose) and long-term energy stores (that is, adipose tissue mass). Rather than viewing the adipose tissue and glucose control systems separately, we suggest that the brain systems that control them are components of a larger, highly integrated, 'fuel homeostasis' control system. This conceptual framework, along with new insights into the organization and function of distinct neuronal systems, provides a context within which to understand how metabolic homeostasis is achieved in both basal and postprandial states. We also review evidence that dysfunction of the central fuel homeostasis system contributes to the close association between obesity and type 2 diabetes, with the goal of identifying more effective treatment options for these common metabolic disorders.
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Affiliation(s)
- Martin G Myers
- Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Alison H Affinati
- Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Nicole Richardson
- UW Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Michael W Schwartz
- UW Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA.
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29
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Holt MK, Rinaman L. The role of nucleus of the solitary tract glucagon-like peptide-1 and prolactin-releasing peptide neurons in stress: anatomy, physiology and cellular interactions. Br J Pharmacol 2021; 179:642-658. [PMID: 34050926 PMCID: PMC8820208 DOI: 10.1111/bph.15576] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/04/2021] [Accepted: 05/17/2021] [Indexed: 02/06/2023] Open
Abstract
Neuroendocrine, behavioural and autonomic responses to stressful stimuli are orchestrated by complex neural circuits. The caudal nucleus of the solitary tract (cNTS) in the dorsomedial hindbrain is uniquely positioned to integrate signals of both interoceptive and psychogenic stress. Within the cNTS, glucagon‐like peptide‐1 (GLP‐1) and prolactin‐releasing peptide (PrRP) neurons play crucial roles in organising neural responses to a broad range of stressors. In this review we discuss the anatomical and functional overlap between PrRP and GLP‐1 neurons. We outline their co‐activation in response to stressful stimuli and their importance as mediators of behavioural and physiological stress responses. Finally, we review evidence that PrRP neurons are downstream of GLP‐1 neurons and outline unexplored areas of the research field. Based on the current state‐of‐knowledge, PrRP and GLP‐1 neurons may be compelling targets in the treatment of stress‐related disorders.
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Affiliation(s)
- Marie K Holt
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Linda Rinaman
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida, USA
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30
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Ludwig MQ, Cheng W, Gordian D, Lee J, Paulsen SJ, Hansen SN, Egerod KL, Barkholt P, Rhodes CJ, Secher A, Knudsen LB, Pyke C, Myers MG, Pers TH. A genetic map of the mouse dorsal vagal complex and its role in obesity. Nat Metab 2021; 3:530-545. [PMID: 33767443 DOI: 10.1038/s42255-021-00363-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 02/16/2021] [Indexed: 02/07/2023]
Abstract
The brainstem dorsal vagal complex (DVC) is known to regulate energy balance and is the target of appetite-suppressing hormones, such as glucagon-like peptide 1 (GLP-1). Here we provide a comprehensive genetic map of the DVC and identify neuronal populations that control feeding. Combining bulk and single-nucleus gene expression and chromatin profiling of DVC cells, we reveal 25 neuronal populations with unique transcriptional and chromatin accessibility landscapes and peptide receptor expression profiles. GLP-1 receptor (GLP-1R) agonist administration induces gene expression alterations specific to two distinct sets of Glp1r neurons-one population in the area postrema and one in the nucleus of the solitary tract that also expresses calcitonin receptor (Calcr). Transcripts and regions of accessible chromatin near obesity-associated genetic variants are enriched in the area postrema and the nucleus of the solitary tract neurons that express Glp1r and/or Calcr, and activating several of these neuronal populations decreases feeding in rodents. Thus, DVC neuronal populations associated with obesity predisposition suppress feeding and may represent therapeutic targets for obesity.
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Affiliation(s)
- Mette Q Ludwig
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Wenwen Cheng
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Desiree Gordian
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Julie Lee
- Novo Nordisk Foundation Center for Stem Cell Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Kristoffer L Egerod
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Christopher J Rhodes
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Anna Secher
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | | | - Charles Pyke
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Tune H Pers
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
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31
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McLean BA, Wong CK, Campbell JE, Hodson DJ, Trapp S, Drucker DJ. Revisiting the Complexity of GLP-1 Action from Sites of Synthesis to Receptor Activation. Endocr Rev 2021; 42:101-132. [PMID: 33320179 PMCID: PMC7958144 DOI: 10.1210/endrev/bnaa032] [Citation(s) in RCA: 112] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 02/06/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is produced in gut endocrine cells and in the brain, and acts through hormonal and neural pathways to regulate islet function, satiety, and gut motility, supporting development of GLP-1 receptor (GLP-1R) agonists for the treatment of diabetes and obesity. Classic notions of GLP-1 acting as a meal-stimulated hormone from the distal gut are challenged by data supporting production of GLP-1 in the endocrine pancreas, and by the importance of brain-derived GLP-1 in the control of neural activity. Moreover, attribution of direct vs indirect actions of GLP-1 is difficult, as many tissue and cellular targets of GLP-1 action do not exhibit robust or detectable GLP-1R expression. Furthermore, reliable detection of the GLP-1R is technically challenging, highly method dependent, and subject to misinterpretation. Here we revisit the actions of GLP-1, scrutinizing key concepts supporting gut vs extra-intestinal GLP-1 synthesis and secretion. We discuss new insights refining cellular localization of GLP-1R expression and integrate recent data to refine our understanding of how and where GLP-1 acts to control inflammation, cardiovascular function, islet hormone secretion, gastric emptying, appetite, and body weight. These findings update our knowledge of cell types and mechanisms linking endogenous vs pharmacological GLP-1 action to activation of the canonical GLP-1R, and the control of metabolic activity in multiple organs.
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Affiliation(s)
- Brent A McLean
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, Canada
| | - Chi Kin Wong
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, Canada
| | - Jonathan E Campbell
- The Department of Medicine, Division of Endocrinology, Department of Pharmacology and Cancer Biology, Duke Molecular Physiology Institute, Duke University, Durham, NC, USA
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, and Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, UCL, London, UK
| | - Daniel J Drucker
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, Canada
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Browning KN, Carson KE. Central Neurocircuits Regulating Food Intake in Response to Gut Inputs-Preclinical Evidence. Nutrients 2021; 13:nu13030908. [PMID: 33799575 PMCID: PMC7998662 DOI: 10.3390/nu13030908] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/02/2021] [Accepted: 03/07/2021] [Indexed: 02/07/2023] Open
Abstract
The regulation of energy balance requires the complex integration of homeostatic and hedonic pathways, but sensory inputs from the gastrointestinal (GI) tract are increasingly recognized as playing critical roles. The stomach and small intestine relay sensory information to the central nervous system (CNS) via the sensory afferent vagus nerve. This vast volume of complex sensory information is received by neurons of the nucleus of the tractus solitarius (NTS) and is integrated with responses to circulating factors as well as descending inputs from the brainstem, midbrain, and forebrain nuclei involved in autonomic regulation. The integrated signal is relayed to the adjacent dorsal motor nucleus of the vagus (DMV), which supplies the motor output response via the efferent vagus nerve to regulate and modulate gastric motility, tone, secretion, and emptying, as well as intestinal motility and transit; the precise coordination of these responses is essential for the control of meal size, meal termination, and nutrient absorption. The interconnectivity of the NTS implies that many other CNS areas are capable of modulating vagal efferent output, emphasized by the many CNS disorders associated with dysregulated GI functions including feeding. This review will summarize the role of major CNS centers to gut-related inputs in the regulation of gastric function with specific reference to the regulation of food intake.
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Sabatini PV, Frikke-Schmidt H, Arthurs J, Gordian D, Patel A, Rupp AC, Adams JM, Wang J, Beck Jørgensen S, Olson DP, Palmiter RD, Myers MG, Seeley RJ. GFRAL-expressing neurons suppress food intake via aversive pathways. Proc Natl Acad Sci U S A 2021; 118:e2021357118. [PMID: 33593916 PMCID: PMC7923658 DOI: 10.1073/pnas.2021357118] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The TGFβ cytokine family member, GDF-15, reduces food intake and body weight and represents a potential treatment for obesity. Because the brainstem-restricted expression pattern of its receptor, GDNF Family Receptor α-like (GFRAL), presents an exciting opportunity to understand mechanisms of action for area postrema neurons in food intake; we generated GfralCre and conditional GfralCreERT mice to visualize and manipulate GFRAL neurons. We found infection or pathophysiologic states (rather than meal ingestion) stimulate GFRAL neurons. TRAP-Seq analysis of GFRAL neurons revealed their expression of a wide range of neurotransmitters and neuropeptides. Artificially activating GfralCre -expressing neurons inhibited feeding, decreased gastric emptying, and promoted a conditioned taste aversion (CTA). GFRAL neurons most strongly innervate the parabrachial nucleus (PBN), where they target CGRP-expressing (CGRPPBN) neurons. Silencing CGRPPBN neurons abrogated the aversive and anorexic effects of GDF-15. These findings suggest that GFRAL neurons link non-meal-associated pathophysiologic signals to suppress nutrient uptake and absorption.
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Affiliation(s)
- Paul V Sabatini
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | | | - Joe Arthurs
- Howard Hughes Medical Institute and Department of Biochemistry, University of Washington, Seattle, WA 98115
- Howard Hughes Medical Institute and Department of Genome Sciences, University of Washington, Seattle, WA 98115
| | - Desiree Gordian
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Anita Patel
- Department of Surgery, University of Michigan, Ann Arbor, MI 48109
| | - Alan C Rupp
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jessica M Adams
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109
- School of Biological Sciences, Illinois State University, Normal, IL 61790
| | - Jine Wang
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
- College of Medical Science, China Three Gorges University, 43002 Yichang, China
| | | | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109
| | - Richard D Palmiter
- Howard Hughes Medical Institute and Department of Biochemistry, University of Washington, Seattle, WA 98115
- Howard Hughes Medical Institute and Department of Genome Sciences, University of Washington, Seattle, WA 98115
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, MI 48109;
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Abstract
Interoceptive signals from gut and adipose tissue and sensory cues from the environment are integrated by hubs in the brain to regulate feeding behavior and maintain homeostatic control of body weight. In vivo neural recordings have revealed that these signals control the activity of multiple layers of hunger neurons and eating is not only the result of feedback correction to a set point, but can also be under the influence of anticipatory regulations. A series of recent technical developments have revealed how peripheral and sensory signals, in particular, from the gut are conveyed to the brain to integrate neural circuits. Here, we describe the mechanisms involved in gastrointestinal stimulation by nutrients and how these signals act on the hindbrain to generate motivated behaviors. We also consider the organization of multidirectional intra- and extrahypothalamic circuits and how this has created a framework for understanding neural control of feeding.
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Affiliation(s)
- Alexandre Moura-Assis
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas, Campinas, Brazil
- Laboratory of Molecular Genetics, The Rockefeller University, New York, New York
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, The Rockefeller University, New York, New York
- Howard Hughes Medical Institute, New York, New York
| | - Licio A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas, Campinas, Brazil
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Abstract
Glucagon like peptide-1 (GLP-1), a peptide hormone from the intestinal tract, plays a central role in the coordination of postprandial glucose homeostasis through actions on insulin secretion, food intake and gut motility. GLP-1 forms the basis for a variety of current drugs for the treatment of type 2 diabetes and obesity, as well as new agents currently being developed. Here, we provide a concise overview of the core physiology of GLP-1 secretion and action, and the role of the peptide in human health, disease and therapeutics.
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Affiliation(s)
- Fiona M Gribble
- Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Frank Reimann
- Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
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Brierley DI, Holt MK, Singh A, de Araujo A, McDougle M, Vergara M, Afaghani MH, Lee SJ, Scott K, Maske C, Langhans W, Krause E, de Kloet A, Gribble FM, Reimann F, Rinaman L, de Lartigue G, Trapp S. Central and peripheral GLP-1 systems independently suppress eating. Nat Metab 2021; 3:258-273. [PMID: 33589843 PMCID: PMC7116821 DOI: 10.1038/s42255-021-00344-4] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 01/13/2021] [Indexed: 01/31/2023]
Abstract
The anorexigenic peptide glucagon-like peptide-1 (GLP-1) is secreted from gut enteroendocrine cells and brain preproglucagon (PPG) neurons, which, respectively, define the peripheral and central GLP-1 systems. PPG neurons in the nucleus tractus solitarii (NTS) are widely assumed to link the peripheral and central GLP-1 systems in a unified gut-brain satiation circuit. However, direct evidence for this hypothesis is lacking, and the necessary circuitry remains to be demonstrated. Here we show that PPGNTS neurons encode satiation in mice, consistent with vagal signalling of gastrointestinal distension. However, PPGNTS neurons predominantly receive vagal input from oxytocin-receptor-expressing vagal neurons, rather than those expressing GLP-1 receptors. PPGNTS neurons are not necessary for eating suppression by GLP-1 receptor agonists, and concurrent PPGNTS neuron activation suppresses eating more potently than semaglutide alone. We conclude that central and peripheral GLP-1 systems suppress eating via independent gut-brain circuits, providing a rationale for pharmacological activation of PPGNTS neurons in combination with GLP-1 receptor agonists as an obesity treatment strategy.
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Affiliation(s)
- Daniel I Brierley
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Marie K Holt
- Department of Psychology, Program in Neuroscience, Florida State University, Gainesville, FL, USA
| | - Arashdeep Singh
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Alan de Araujo
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Molly McDougle
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Macarena Vergara
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Majd H Afaghani
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Shin Jae Lee
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Karen Scott
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Calyn Maske
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Wolfgang Langhans
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Eric Krause
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
| | - Annette de Kloet
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
| | - Fiona M Gribble
- Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Frank Reimann
- Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Linda Rinaman
- Department of Psychology, Program in Neuroscience, Florida State University, Gainesville, FL, USA
| | - Guillaume de Lartigue
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA.
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA.
| | - Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
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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.
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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.)
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Leptin Sensitizes NTS Neurons to Vagal Input by Increasing Postsynaptic NMDA Receptor Currents. J Neurosci 2020; 40:7054-7064. [PMID: 32817248 DOI: 10.1523/jneurosci.1865-19.2020] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/05/2019] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Leptin signaling within the nucleus of the solitary tract (NTS) contributes to the control of food intake, and injections of leptin into the NTS reduce meal size and increase the efficacy of vagus-mediated satiation signals. Leptin receptors (LepRs) are expressed by vagal afferents as well as by a population of NTS neurons. However, the electrophysiological properties of LepR-expressing NTS neurons have not been well characterized, and it is unclear how leptin might act on these neurons to reduce food intake. To address this question, we recorded from LepR-expressing neurons in horizontal brain slices containing the NTS from male and female LepR-Cre X Rosa-tdTomato mice. We found that the vast majority of NTS LepR neurons received monosynaptic innervation from vagal afferent fibers and LepR neurons exhibited large synaptic NMDA receptor (NMDAR)-mediated currents compared with non-LepR neurons. During high-frequency stimulation of vagal afferents, leptin increased the size of NMDAR-mediated currents, but not AMPAR-mediated currents. Leptin also increased the size of evoked EPSPs and the ability of low-intensity solitary tract stimulation to evoke action potentials in LepR neurons. These effects of leptin were blocked by bath applying a competitive NMDAR antagonist (DCPP-ene) or by an NMDAR channel blocker applied through the recording pipette (MK-801). Last, feeding studies using male rats demonstrate that intra-NTS injections of DCPP-ene attenuate reduction of overnight food intake following intra-NTS leptin injection. Our results suggest that leptin acts in the NTS to reduce food intake by increasing NMDAR-mediated currents, thus enhancing NTS sensitivity to vagal inputs.SIGNIFICANCE STATEMENT Leptin is a hormone that critically impacts food intake and energy homeostasis. The nucleus of the solitary tract (NTS) is activated by vagal afferents from the gastrointestinal tract, which promotes termination of a meal. Injection of leptin into the NTS inhibits food intake, while knockdown of leptin receptors (LepRs) in NTS neurons increases food intake. However, little was known about how leptin acts in the NTS neurons to inhibit food intake. We found that leptin increases the sensitivity of LepR-expressing neurons to vagal inputs by increasing NMDA receptor-mediated synaptic currents and that NTS NMDAR activation contributes to leptin-induced reduction of food intake. These findings suggest a novel mechanism by which leptin, acting in the NTS, could potentiate gastrointestinal satiation signals.
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