1
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Cornejo MP, Fernandez G, Cabral A, Barrile F, Heredia F, García Romero G, Zubimendi Sampieri JP, Quelas JI, Cantel S, Fehrentz JA, Alonso A, Pla R, Ferran JL, Andreoli MF, De Francesco PN, Perelló M. GHSR in a Subset of GABA Neurons Controls Food Deprivation-Induced Hyperphagia in Male Mice. Endocrinology 2024; 165:bqae061. [PMID: 38815068 DOI: 10.1210/endocr/bqae061] [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: 03/06/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/01/2024]
Abstract
The growth hormone secretagogue receptor (GHSR), primarily known as the receptor for the hunger hormone ghrelin, potently controls food intake, yet the specific Ghsr-expressing cells mediating the orexigenic effects of this receptor remain incompletely characterized. Since Ghsr is expressed in gamma-aminobutyric acid (GABA)-producing neurons, we sought to investigate whether the selective expression of Ghsr in a subset of GABA neurons is sufficient to mediate GHSR's effects on feeding. First, we crossed mice that express a tamoxifen-dependent Cre recombinase in the subset of GABA neurons that express glutamic acid decarboxylase 2 (Gad2) enzyme (Gad2-CreER mice) with reporter mice, and found that ghrelin mainly targets a subset of Gad2-expressing neurons located in the hypothalamic arcuate nucleus (ARH) and that is predominantly segregated from Agouti-related protein (AgRP)-expressing neurons. Analysis of various single-cell RNA-sequencing datasets further corroborated that the primary subset of cells coexpressing Gad2 and Ghsr in the mouse brain are non-AgRP ARH neurons. Next, we crossed Gad2-CreER mice with reactivable GHSR-deficient mice to generate mice expressing Ghsr only in Gad2-expressing neurons (Gad2-GHSR mice). We found that ghrelin treatment induced the expression of the marker of transcriptional activation c-Fos in the ARH of Gad2-GHSR mice, yet failed to induce food intake. In contrast, food deprivation-induced refeeding was higher in Gad2-GHSR mice than in GHSR-deficient mice and similar to wild-type mice, suggesting that ghrelin-independent roles of GHSR in a subset of GABA neurons is sufficient for eliciting full compensatory hyperphagia in mice.
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Affiliation(s)
- María Paula Cornejo
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | - Gimena Fernandez
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | - Agustina Cabral
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | - Franco Barrile
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | - Florencia Heredia
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | - Guadalupe García Romero
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | | | | | - Sonia Cantel
- Institut des Biomolécules Max Mousseron, Univ Montpellier, CNRS, ENSCM, Montpellier, France
| | - Jean-Alain Fehrentz
- Institut des Biomolécules Max Mousseron, Univ Montpellier, CNRS, ENSCM, Montpellier, France
| | - Antonia Alonso
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia 30100, Spain
- Institute of Biomedical Research of Murcia-IMIB, Virgen de la Arrixaca University Hospital, Murcia 30100, Spain
| | - Ramon Pla
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia 30100, Spain
- Institute of Biomedical Research of Murcia-IMIB, Virgen de la Arrixaca University Hospital, Murcia 30100, Spain
| | - José Luis Ferran
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia 30100, Spain
- Institute of Biomedical Research of Murcia-IMIB, Virgen de la Arrixaca University Hospital, Murcia 30100, Spain
| | - María Florencia Andreoli
- Instituto de Desarrollo e Investigaciones Pediátricas (IDIP), HIAEP Sor María Ludovica de La Plata, Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
- Department of Surgical Sciences, Functional Pharmacology and Neuroscience, Uppsala University, Uppsala 751 24, Sweden
| | - Pablo Nicolas De Francesco
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
| | - Mario Perelló
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional la Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata 1900, Buenos Aires, Argentina
- Department of Surgical Sciences, Functional Pharmacology and Neuroscience, Uppsala University, Uppsala 751 24, Sweden
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2
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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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3
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Zhang SX, Kim A, Madara JC, Zhu PK, Christenson LF, Lutas A, Kalugin PN, Jin Y, Pal A, Tian L, Lowell BB, Andermann ML. Competition between stochastic neuropeptide signals calibrates the rate of satiation. RESEARCH SQUARE 2023:rs.3.rs-3185572. [PMID: 37546985 PMCID: PMC10402269 DOI: 10.21203/rs.3.rs-3185572/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
We investigated how transmission of hunger- and satiety-promoting neuropeptides, NPY and αMSH, is integrated at the level of intracellular signaling to control feeding. Receptors for these peptides use the second messenger cAMP. How cAMP integrates opposing peptide signals to regulate energy balance, and the in vivo spatiotemporal dynamics of endogenous peptidergic signaling, remain largely unknown. We show that AgRP axon stimulation in the paraventricular hypothalamus evokes probabilistic NPY release that triggers stochastic cAMP decrements in downstream MC4R-expressing neurons (PVHMC4R). Meanwhile, POMC axon stimulation triggers stochastic, αMSH-dependent cAMP increments. Release of either peptide impacts a ~100 μm diameter region, and when these peptide signals overlap, they compete to control cAMP. The competition is reflected by hunger-state-dependent differences in the amplitude and persistence of cAMP transients: hunger peptides are more efficacious in the fasted state, satiety peptides in the fed state. Feeding resolves the competition by simultaneously elevating αMSH release and suppressing NPY release, thereby sustaining elevated cAMP in PVHMC4R neurons. In turn, cAMP potentiates feeding-related excitatory inputs and promotes satiation across minutes. Our findings highlight how biochemical integration of opposing, quantal peptide signals during energy intake orchestrates a gradual transition between stable states of hunger and satiety.
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Affiliation(s)
- Stephen X Zhang
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
- Co-corresponding authors
| | - Angela Kim
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Joseph C Madara
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Paula K Zhu
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Lauren F Christenson
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Andrew Lutas
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
- Present address: Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter N Kalugin
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
- Program in Neuroscience, Harvard University, Cambridge, MA 02138, USA
| | - Yihan Jin
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Akash Pal
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Bradford B Lowell
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Mark L Andermann
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
- Program in Neuroscience, Harvard University, Cambridge, MA 02138, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
- Co-corresponding authors
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4
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Zhang SX, Kim A, Madara JC, Zhu PK, Christenson LF, Lutas A, Kalugin PN, Jin Y, Pal A, Tian L, Lowell BB, Andermann ML. Competition between stochastic neuropeptide signals calibrates the rate of satiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.11.548551. [PMID: 37503012 PMCID: PMC10369917 DOI: 10.1101/2023.07.11.548551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
We investigated how transmission of hunger- and satiety-promoting neuropeptides, NPY and αMSH, is integrated at the level of intracellular signaling to control feeding. Receptors for these peptides use the second messenger cAMP, but the messenger's spatiotemporal dynamics and role in energy balance are controversial. We show that AgRP axon stimulation in the paraventricular hypothalamus evokes probabilistic and spatially restricted NPY release that triggers stochastic cAMP decrements in downstream MC4R-expressing neurons (PVH MC4R ). Meanwhile, POMC axon stimulation triggers stochastic, αMSH-dependent cAMP increments. NPY and αMSH competitively control cAMP, as reflected by hunger-state-dependent differences in the amplitude and persistence of cAMP transients evoked by each peptide. During feeding bouts, elevated αMSH release and suppressed NPY release cooperatively sustain elevated cAMP in PVH MC4R neurons, thereby potentiating feeding-related excitatory inputs and promoting satiation across minutes. Our findings highlight how state-dependent integration of opposing, quantal peptidergic events by a common biochemical target calibrates energy intake.
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5
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Carrero L, Antequera D, Alcalde I, Megías D, Figueiro-Silva J, Merayo-Lloves J, Municio C, Carro E. Disturbed circadian rhythm and retinal degeneration in a mouse model of Alzheimer's disease. Acta Neuropathol Commun 2023; 11:55. [PMID: 37004084 PMCID: PMC10067208 DOI: 10.1186/s40478-023-01529-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/11/2023] [Indexed: 04/03/2023] Open
Abstract
The circadian clock is synchronized to the 24 h day by environmental light which is transmitted from the retina to the suprachiasmatic nucleus (SCN) primarily via the retinohypothalamic tract (RHT). Circadian rhythm abnormalities have been reported in neurodegenerative disorders such as Alzheimer's disease (AD). Whether these AD-related changes are a result of the altered clock gene expression, retina degeneration, including the dysfunction in RHT transmission, loss of retinal ganglion cells and its electrophysiological capabilities, or a combination of all of these pathological mechanisms, is not known. Here, we evaluated transgenic APP/PS1 mouse model of AD and wild-type mice at 6- and 12-month-old, as early and late pathological stage, respectively. We noticed the alteration of circadian clock gene expression not only in the hypothalamus but also in two extra-hypothalamic brain regions, cerebral cortex and hippocampus, in APP/PS1 mice. These alterations were observed in 6-month-old transgenic mice and were exacerbated at 12 months of age. This could be explained by the reduced RHT projections in the SCN of APP/PS1 mice, correlating with downregulation of hypothalamic GABAergic response in APP/PS1 mice in advanced stage of pathology. Importantly, we also report retinal degeneration in APP/PS1 mice, including Aβ deposits and reduced choline acetyltransferase levels, loss of melanopsin retinal ganglion cells and functional integrity mainly of inner retina layers. Our findings support the theory that retinal degeneration constitutes an early pathological event that directly affects the control of circadian rhythm in AD.
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Affiliation(s)
- Laura Carrero
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), 28041, Madrid, Spain
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- Autonoma de Madrid University, Madrid, Spain
| | - Desireé Antequera
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Ignacio Alcalde
- Instituto Universitario Fernández-Vega, Universidad de Oviedo and Fundación de Investigación Oftalmológica, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Diego Megías
- Advanced Optical Microscopy Unit, Unidades Centrales Científico-Técnicas, Instituto de Salud Carlos III, Madrid, Spain
| | - Joana Figueiro-Silva
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland
- Department of Molecular Life Science, University of Zurich, Zurich, Switzerland
| | - Jesús Merayo-Lloves
- Instituto Universitario Fernández-Vega, Universidad de Oviedo and Fundación de Investigación Oftalmológica, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Cristina Municio
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), 28041, Madrid, Spain.
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain.
| | - Eva Carro
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain.
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain.
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6
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Wagner S, Brierley DI, Leeson-Payne A, Jiang W, Chianese R, Lam BYH, Dowsett GKC, Cristiano C, Lyons D, Reimann F, Gribble FM, Martinez de Morentin PB, Yeo GSH, Trapp S, Heisler LK. Obesity medication lorcaserin activates brainstem GLP-1 neurons to reduce food intake and augments GLP-1 receptor agonist induced appetite suppression. Mol Metab 2023; 68:101665. [PMID: 36592795 PMCID: PMC9841057 DOI: 10.1016/j.molmet.2022.101665] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/23/2022] [Accepted: 12/26/2022] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Overweight and obesity are endemic in developed countries, with a substantial negative impact on human health. Medications developed to treat obesity include agonists for the G-protein coupled receptors glucagon-like peptide-1 (GLP-1R; e.g. liraglutide), serotonin 2C (5-HT2CR; e.g, lorcaserin), and melanocortin4 (MC4R) which reduce body weight primarily by suppressing food intake. However, the mechanisms underlying the therapeutic food intake suppressive effects are still being defined and were investigated here. METHODS We profiled PPG neurons in the nucleus of the solitary tract (PPGNTS) using single nucleus RNA sequencing (Nuc-Seq) and histochemistry. We next examined the requirement of PPGNTS neurons for obesity medication effects on food intake by virally ablating PPGNTS neurons. Finally, we assessed the effects on food intake of the combination of liraglutide and lorcaserin. RESULTS We found that 5-HT2CRs, but not GLP-1Rs or MC4Rs, were widespread in PPGNTS clusters and that lorcaserin significantly activated PPGNTS neurons. Accordingly, ablation of PPGNTS neurons prevented the reduction of food intake by lorcaserin but not MC4R agonist melanotan-II, demonstrating the functional significance of PPGNTS 5-HT2CR expression. Finally, the combination of lorcaserin with GLP-1R agonists liraglutide or exendin-4 produced greater food intake reduction as compared to either monotherapy. CONCLUSIONS These findings identify a necessary mechanism through which obesity medication lorcaserin produces its therapeutic benefit, namely brainstem PPGNTS neurons. Moreover, these data reveal a strategy to augment the therapeutic profile of the current frontline treatment for obesity, GLP-1R agonists, via coadministration with 5-HT2CR agonists.
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Affiliation(s)
- Stefan Wagner
- The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Daniel I Brierley
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | | | - Wanqing Jiang
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | | | - Brian Y H Lam
- Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, Medical Research Council Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - Georgina K C Dowsett
- Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, Medical Research Council Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | | | - David Lyons
- The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Frank Reimann
- Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, Medical Research Council Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - Fiona M Gribble
- Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, Medical Research Council Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | | | - Giles S H Yeo
- Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, Medical Research Council Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK.
| | - Lora K Heisler
- The Rowett Institute, University of Aberdeen, Aberdeen, UK.
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7
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Patra PH, Tench B, Hitrec T, Holmes F, Drake R, Cerritelli S, Spanswick D, Pickering AE. Pro-Opiomelanocortin (POMC) neurons in the nucleus of the solitary tract mediate endorphinergic endogenous analgesia in mice. Pain 2022; 164:1051-1066. [PMID: 36448978 DOI: 10.1097/j.pain.0000000000002802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 09/27/2022] [Indexed: 12/02/2022]
Abstract
ABSTRACT The nucleus of the solitary tract (NTS) contains pro-opiomelanocortin (POMC) neurons which are one of the two major sources of β-endorphin in the brain. The functional role of these NTS POMC neurons in nociceptive and cardiorespiratory function is debated. We have shown that NTS POMC optogenetic activation produces bradycardia and transient apnoea in a working heart brainstem preparation and chemogenetic activation with an engineered ion channel (PSAM) produced opioidergic analgesia in vivo . To better define the role of the NTS POMC neurons in behaving animals, we adopted in vivo optogenetics (ChrimsonR) and excitatory/inhibitory chemogenetic DREADD (hM3Dq/hM4Di) strategies in POMC-Cre mice. We show that optogenetic activation of NTS POMC neurons produces time-locked, graded, transient bradycardia and bradypnoea in anaesthetised mice which is naloxone sensitive (1 mg/kg, i.p) suggesting a role of β-endorphin. Both optogenetic and chemogenetic activation of NTS POMC neurons produces sustained thermal analgesia in behaving mice which can be blocked by naloxone. It also produced analgesia in inflammatory pain (carrageenan) but not in a neuropathic pain model (tibial nerve transection). Inhibiting NTS POMC neurons does not produce any effect on basal nociception but inhibits stress-induced analgesia (unlike inhibition of arcuate POMC neurons). Activation of NTS POMC neuronal populations in conscious mice did not cause respiratory depression, anxiety or locomotor deficit (in open field) nor affective preference. These findings indicate that NTS POMC neurons play a key role in the generation of endorphinergic endogenous analgesia and can also regulate cardiorespiratory function.
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Affiliation(s)
- Pabitra Hriday Patra
- Anaesthesia, Pain & Critical Care Research, School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK
| | - Becks Tench
- Anaesthesia, Pain & Critical Care Research, School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK
| | - Timna Hitrec
- Anaesthesia, Pain & Critical Care Research, School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK
| | - Fiona Holmes
- Anaesthesia, Pain & Critical Care Research, School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK
| | - Robert Drake
- Anaesthesia, Pain & Critical Care Research, School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK
| | - Serena Cerritelli
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - David Spanswick
- Neurosolutions, University of Warwick, Gibbet Hill Road, Coventry, West Midlands, CV4 7AL, UK
| | - Anthony Edward Pickering
- Anaesthesia, Pain & Critical Care Research, School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK
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8
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Yu M, Bean JC, Liu H, He Y, Yang Y, Cai X, Yu K, Pei Z, Liu H, Tu L, Conde KM, Wang M, Li Y, Yin N, Zhang N, Han J, Scarcelli NA, Xu P, He Y, Xu Y, Wang C. SK3 in POMC neurons plays a sexually dimorphic role in energy and glucose homeostasis. Cell Biosci 2022; 12:170. [PMID: 36210455 PMCID: PMC9549684 DOI: 10.1186/s13578-022-00907-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Pro-opiomelanocortin (POMC) neurons play a sexually dimorphic role in body weight and glucose balance. However, the mechanisms for the sex differences in POMC neuron functions are not fully understood. RESULTS We detected small conductance calcium-activated potassium (SK) current in POMC neurons. Secondary analysis of published single-cell RNA-Seq data showed that POMC neurons abundantly express SK3, one SK channel subunit. To test whether SK3 in POMC neurons regulates POMC neuron functions on energy and glucose homeostasis, we used a Cre-loxP strategy to delete SK3 specifically from mature POMC neurons. POMC-specific deletion of SK3 did not affect body weight in either male or female mice. Interestingly, male mutant mice showed not only decreased food intake but also decreased physical activity, resulting in unchanged body weight. Further, POMC-specific SK3 deficiency impaired glucose balance specifically in female mice but not in male mice. Finally, no sex differences were detected in the expression of SK3 and SK current in total POMC neurons. However, we found higher SK current but lower SK3 positive neuron population in male POMC neurons co-expressing estrogen receptor α (ERα) compared to that in females. CONCLUSION These results revealed a sexually dimorphic role of SK3 in POMC neurons in both energy and glucose homeostasis independent of body weight control, which was associated with the sex difference of SK current in a subpopulation of POMC + ERα + neurons.
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Affiliation(s)
- Meng Yu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Jonathan C. Bean
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Hailan Liu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Yang He
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Yongjie Yang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Xing Cai
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Kaifan Yu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Zhou Pei
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Hesong Liu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Longlong Tu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Kristine M. Conde
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Mengjie Wang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Yongxiang Li
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Na Yin
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Nan Zhang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Junying Han
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Nikolas A. Scarcelli
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Pingwen Xu
- grid.185648.60000 0001 2175 0319Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612 USA
| | - Yanlin He
- grid.64337.350000 0001 0662 7451Pennington Biomedical Research Center, Brain glycemic and metabolism control department, Louisiana State University, Baton Rouge, LA 70808 USA
| | - Yong Xu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA ,grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Chunmei Wang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
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9
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dos Santos WO, Wasinski F, Tavares MR, Campos AMP, Elias CF, List EO, Kopchick JJ, Szawka RE, Donato J. Ablation of Growth Hormone Receptor in GABAergic Neurons Leads to Increased Pulsatile Growth Hormone Secretion. Endocrinology 2022; 163:6634255. [PMID: 35803590 PMCID: PMC9302893 DOI: 10.1210/endocr/bqac103] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Indexed: 11/19/2022]
Abstract
Growth hormone (GH) acts in several hypothalamic neuronal populations to modulate metabolism and the autoregulation of GH secretion via negative-feedback loops. However, few studies have investigated whether GH receptor (GHR) expression in specific neuronal populations is required for the homeostatic control of GH secretion and energy homeostasis. In the present study, we investigated the consequences of the specific GHR ablation in GABAergic (VGAT-expressing) or glutamatergic (VGLUT2-expressing) cells. GHR ablation in GABAergic neurons led to increased GH secretion, lean mass, and body growth in male and female mice. VGAT-specific GHR knockout (KO) male mice also showed increased serum insulin-like growth factor-1, hypothalamic Ghrh, and hepatic Igf1 messenger RNA levels. In contrast, normal GH secretion, but reduced lean body mass, was observed in mice carrying GHR ablation in glutamatergic neurons. GHR ablation in GABAergic cells increased weight loss and led to decreased blood glucose levels during food restriction, whereas VGLUT2-specific GHR KO mice showed blunted feeding response to 2-deoxy-D-glucose both in males and females, and increased relative food intake, oxygen consumption, and serum leptin levels in male mice. Of note, VGLUT2-cre female mice, independently of GHR ablation, exhibited a previously unreported phenotype of mild reduction in body weight without further metabolic alterations. The autoregulation of GH secretion via negative-feedback loops requires GHR expression in GABAergic cells. Furthermore, GHR ablation in GABAergic and glutamatergic neuronal populations leads to distinct metabolic alterations. These findings contribute to the understanding of the neuronal populations responsible for mediating the neuroendocrine and metabolic effects of GH.
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Affiliation(s)
- Willian O dos Santos
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, 05508-000, Brazil
| | - Frederick Wasinski
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, 05508-000, Brazil
| | - Mariana R Tavares
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, 05508-000, Brazil
| | - Ana M P Campos
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, 05508-000, Brazil
| | - Carol F Elias
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, 48109-5622, USA
| | - Edward O List
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, 45701, USA
| | - John J Kopchick
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, 45701, USA
| | - Raphael E Szawka
- Department of Physiology and Biophysics, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Jose Donato
- Correspondence: Jose Donato Jr, PhD, Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Av. Prof Lineu Prestes, 1524, São Paulo, 05508-000, Brazil.
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10
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Watts AG, Kanoski SE, Sanchez-Watts G, Langhans W. The physiological control of eating: signals, neurons, and networks. Physiol Rev 2022; 102:689-813. [PMID: 34486393 PMCID: PMC8759974 DOI: 10.1152/physrev.00028.2020] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
During the past 30 yr, investigating the physiology of eating behaviors has generated a truly vast literature. This is fueled in part by a dramatic increase in obesity and its comorbidities that has coincided with an ever increasing sophistication of genetically based manipulations. These techniques have produced results with a remarkable degree of cell specificity, particularly at the cell signaling level, and have played a lead role in advancing the field. However, putting these findings into a brain-wide context that connects physiological signals and neurons to behavior and somatic physiology requires a thorough consideration of neuronal connections: a field that has also seen an extraordinary technological revolution. Our goal is to present a comprehensive and balanced assessment of how physiological signals associated with energy homeostasis interact at many brain levels to control eating behaviors. A major theme is that these signals engage sets of interacting neural networks throughout the brain that are defined by specific neural connections. We begin by discussing some fundamental concepts, including ones that still engender vigorous debate, that provide the necessary frameworks for understanding how the brain controls meal initiation and termination. These include key word definitions, ATP availability as the pivotal regulated variable in energy homeostasis, neuropeptide signaling, homeostatic and hedonic eating, and meal structure. Within this context, we discuss network models of how key regions in the endbrain (or telencephalon), hypothalamus, hindbrain, medulla, vagus nerve, and spinal cord work together with the gastrointestinal tract to enable the complex motor events that permit animals to eat in diverse situations.
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Affiliation(s)
- Alan G Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Scott E Kanoski
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Graciela Sanchez-Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule-Zürich, Schwerzenbach, Switzerland
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11
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Leyrer-Jackson JM, Hood LE, Olive MF. Sex differences and the lack of effects of chemogenetic manipulation of pro-opiomelanocortin (POMC) neurons on alcohol consumption in male and female mice. Brain Res 2022; 1786:147901. [PMID: 35367433 DOI: 10.1016/j.brainres.2022.147901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/02/2022] [Accepted: 03/29/2022] [Indexed: 11/17/2022]
Abstract
The endogenous opioid system has been implicated in the rewarding and reinforcing effects of alcohol. Pro-opiomelanocortin (POMC) neurons located within the arcuate nucleus of the hypothalamus (ArcN) secrete multiple peptides associated with alcohol consumption, including β-endorphin (β-END), α-melanocyte stimulating hormone (α-MSH), and adrenocorticotropic hormone (ACTH). In this study, we utilized chemogenetics to bidirectionally modulate ArcN POMC neurons to determine their role in alcohol and saccharin consumption and regional levels of POMC-derived peptides. Male and female POMC-cre mice were infused with viral vectors designed for cre-dependent expression of either excitatory and inhibitory DREADDs or a control vector into the ArcN. Following recovery, animals were allowed to consume alcohol or saccharin using the drinking-in-the-dark (DID) paradigm of binge-like intake for 4 consecutive days. Prior to the final test session, animals were injected with clozapine-N-oxide (2.5 mg/kg, i.p.) for DREADD activation. Following the last DID session, animals were euthanized and the ArcN, VTA, amygdala and NAc were dissected and assessed for POMC peptide expression utilizing western blotting. We found that female mice consumed more alcohol than males during DID sessions 2-4, and that chemogenetic activation had no effect on alcohol or saccharin consumption in either sex. We found that β-END expression within the ArcN positively correlated with alcohol consumption. Given the molecular and functional heterogeneity of ArcN POMC neurons, future studies are needed to assess the effects of modulation of specific subpopulations of these neurons within the ArcN on consumption of rewarding substances such as alcohol and saccharin.
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Affiliation(s)
| | - Lauren E Hood
- Department of Psychology, Arizona State University, Tempe, AZ 85281, USA
| | - M Foster Olive
- Department of Psychology, Arizona State University, Tempe, AZ 85281, USA
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12
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Hood LE, Nagy EK, Leyrer‐Jackson JM, Olive MF. Ethanol consumption activates a subset of arcuate nucleus pro‐opiomelanocortin (POMC)‐producing neurons: a c‐fos immunohistochemistry study. Physiol Rep 2022; 10:e15231. [PMID: 35312178 PMCID: PMC8935532 DOI: 10.14814/phy2.15231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/21/2022] [Accepted: 02/28/2022] [Indexed: 11/24/2022] Open
Affiliation(s)
- Lauren E. Hood
- Department of Psychology Arizona State University Tempe Arizona 85281 USA
| | - Erin K. Nagy
- Department of Psychology Arizona State University Tempe Arizona 85281 USA
| | | | - M. Foster Olive
- Department of Psychology Arizona State University Tempe Arizona 85281 USA
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13
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Jais A, Brüning JC. Arcuate Nucleus-Dependent Regulation of Metabolism-Pathways to Obesity and Diabetes Mellitus. Endocr Rev 2022; 43:314-328. [PMID: 34490882 PMCID: PMC8905335 DOI: 10.1210/endrev/bnab025] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Indexed: 01/12/2023]
Abstract
The central nervous system (CNS) receives information from afferent neurons, circulating hormones, and absorbed nutrients and integrates this information to orchestrate the actions of the neuroendocrine and autonomic nervous systems in maintaining systemic metabolic homeostasis. Particularly the arcuate nucleus of the hypothalamus (ARC) is of pivotal importance for primary sensing of adiposity signals, such as leptin and insulin, and circulating nutrients, such as glucose. Importantly, energy state-sensing neurons in the ARC not only regulate feeding but at the same time control multiple physiological functions, such as glucose homeostasis, blood pressure, and innate immune responses. These findings have defined them as master regulators, which adapt integrative physiology to the energy state of the organism. The disruption of this fine-tuned control leads to an imbalance between energy intake and expenditure as well as deregulation of peripheral metabolism. Improving our understanding of the cellular, molecular, and functional basis of this regulatory principle in the CNS could set the stage for developing novel therapeutic strategies for the treatment of obesity and metabolic syndrome. In this review, we summarize novel insights with a particular emphasis on ARC neurocircuitries regulating food intake and glucose homeostasis and sensing factors that inform the brain of the organismal energy status.
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Affiliation(s)
- Alexander Jais
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany.,Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Jens C Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany.,Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,National Center for Diabetes Research (DZD), Neuherberg, Germany
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14
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Daimon CM, Hentges ST. Inhibition of POMC neurons in mice undergoing activity-based anorexia selectively blunts food anticipatory activity without affecting body weight or food intake. Am J Physiol Regul Integr Comp Physiol 2022; 322:R219-R227. [PMID: 35043681 PMCID: PMC8858678 DOI: 10.1152/ajpregu.00313.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Anorexia nervosa (AN) is a debilitating eating disorder characterized by severely restricted eating and significant body weight loss. In addition, many individuals also report engaging in excessive exercise. Previous research using the activity-based anorexia (ABA) model has implicated the hypothalamic proopiomelanocortin (POMC) system. Using the ABA model, Pomc mRNA has been shown to be transiently elevated in both male and female rodents undergoing ABA. In addition, the POMC peptide β-endorphin appears to contribute to food anticipatory activity (FAA), a characteristic of ABA, as both deletion and antagonism of the µ opioid receptor (MOR) that β-endorphin targets, results in decreased FAA. The role of β-endorphin in reduced food intake in ABA is unknown and POMC neurons release multiple transmitters in addition to β-endorphin. In the current study, we set out to determine whether targeted inhibition of POMC neurons themselves rather than their peptide products would lessen the severity of ABA. Inhibition of POMC neurons during ABA via chemogenetic Designer Receptors Exclusively Activated by Designer Drugs (DREADD) technology resulted in reduced FAA in both male and female mice with no significant changes in body weight or food intake. The selective reduction in FAA persisted even in the face of concurrent chemogenetic inhibition of additional cell types in the hypothalamic arcuate nucleus. The results suggest that POMC neurons could be contributing preferentially to excessive exercise habits in patients with AN. Furthermore, the results also suggest that metabolic control during ABA appears to take place via a POMC neuron-independent mechanism.
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Affiliation(s)
- Caitlin M. Daimon
- Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Shane T. Hentges
- Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
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15
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Yu H, Rubinstein M, Low MJ. Developmental single-cell transcriptomics of hypothalamic POMC neurons reveal the genetic trajectories of multiple neuropeptidergic phenotypes. eLife 2022; 11:e72883. [PMID: 35044906 PMCID: PMC8806186 DOI: 10.7554/elife.72883] [Citation(s) in RCA: 10] [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: 08/07/2021] [Accepted: 01/18/2022] [Indexed: 11/21/2022] Open
Abstract
Proopiomelanocortin (POMC) neurons of the hypothalamic arcuate nucleus are essential to regulate food intake and energy balance. However, the ontogenetic transcriptional programs that specify the identity and functioning of these neurons are poorly understood. Here, we use single-cell RNA-sequencing (scRNA-seq) to define the transcriptomes characterizing Pomc-expressing cells in the developing hypothalamus and translating ribosome affinity purification with RNA-sequencing (TRAP-seq) to analyze the subsequent translatomes of mature POMC neurons. Our data showed that Pomc-expressing neurons give rise to multiple developmental pathways expressing different levels of Pomc and unique combinations of transcription factors. The predominant cluster, featured by high levels of Pomc and Prdm12 transcripts, represents the canonical arcuate POMC neurons. Additional cell clusters expressing medium or low levels of Pomc mature into different neuronal phenotypes featured by distinct sets of transcription factors, neuropeptides, processing enzymes, cell surface, and nuclear receptors. We conclude that the genetic programs specifying the identity and differentiation of arcuate POMC neurons are diverse and generate a heterogeneous repertoire of neuronal phenotypes early in development that continue to mature postnatally.
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Affiliation(s)
- Hui Yu
- Department of Molecular and Integrative Physiology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Marcelo Rubinstein
- Department of Molecular and Integrative Physiology, University of Michigan Medical SchoolAnn ArborUnited States
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y TécnicasBuenos AiresArgentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos AiresArgentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical SchoolAnn ArborUnited States
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16
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Effect of Electroacupuncture on Reproductive Disorders and Insulin Resistance in a Murine Polycystic Ovary Syndrome Model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:9968463. [PMID: 34987599 PMCID: PMC8720607 DOI: 10.1155/2021/9968463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/02/2021] [Accepted: 09/15/2021] [Indexed: 12/19/2022]
Abstract
Polycystic ovarian syndrome (PCOS) is a common, complex, and heterogeneous endocrine and metabolic disorder. There is no standardized treatment, and it therefore requires individualized therapies according to the symptoms and pathogenesis of each patient. The present study aimed to determine the effect of electroacupuncture at the acupoints Zusanli (ST36), Sanyinjiao (SP6), and Neiguan (PC6) on reproductive disorders and insulin resistance in a murine model of PCOS induced by dehydroepiandrosterone (DHEA). Vaginal smear analysis was used to determine mice estrous cycle; intraperitoneal glucose and insulin tolerance tests were adopted to analyze metabolic characteristics; enzyme-linked immunosorbent assay was used to measure hormone levels; gene expression was quantified with real-time PCR; hematoxylin and eosin staining was used to observe ovarian morphology. We observed disordered estrous cycle, polycystic ovarian morphology, and higher levels of homeostasis model assessment-insulin resistance (HOMA-IR) and testosterone (T), indicating successful modeling of PCOS. DHEA increased levels of estrogen (E2), progesterone (P), testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH), and EA treatment restored them to levels seen in the control group. EA reduced the days in estrus caused by DHEA, improved the abnormal sex hormone receptor genes, and attenuated the DHEA-induced histomorphological changes in mouse ovaries. The average expressions of the androgen receptor (AR), estrogen receptor (ER), luteinizing hormone receptor (LHR), and follicle-stimulating hormone receptor (FSHR) genes in the ovary greatly increased after DHEA treatment and significantly decreased in the DHEA + EA group. After EA treatment, the cystic follicle (CF) number was reduced and corpora lutea (CL) increased in the DHEA + EA group compared to the DHEA group. EA improved glucose intolerance and insulin intolerance. Statistical analysis of intraperitoneal glucose tolerance test-area under curve (IPGTT-AUC) glucose levels revealed a significant decrease in DHEA group mice compared to the control and DHEA + EA groups. EA was found to restore fasting blood glucose, fasting serum insulin, and HOMA-IR. In summary, our study suggests that EA has a remarkable effect in the DHEA-induced murine PCOS model. Management of EA could improve estrous cycle, hormonal disorders, abnormal sex hormone receptors in ovaries, ovary morphology, and insulin resistance in PCOS mice.
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17
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Extrahypothalamic Control of Energy Balance and Its Connection with Reproduction: Roles of the Amygdala. Metabolites 2021; 11:metabo11120837. [PMID: 34940594 PMCID: PMC8708157 DOI: 10.3390/metabo11120837] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 11/24/2022] Open
Abstract
Body energy and metabolic homeostasis are exquisitely controlled by multiple, often overlapping regulatory mechanisms, which permit the tight adjustment between fuel reserves, internal needs, and environmental (e.g., nutritional) conditions. As such, this function is sensitive to and closely connected with other relevant bodily systems, including reproduction and gonadal function. The aim of this mini-review article is to summarize the most salient experimental data supporting a role of the amygdala as a key brain region for emotional learning and behavior, including reward processing, in the physiological control of feeding and energy balance. In particular, a major focus will be placed on the putative interplay between reproductive signals and amygdala pathways, as it pertains to the control of metabolism, as complementary, extrahypothalamic circuit for the integral control of energy balance and gonadal function.
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18
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Metz MJ, Daimon CM, King CM, Rau AR, Hentges ST. Individual arcuate nucleus proopiomelanocortin neurons project to select target sites. Am J Physiol Regul Integr Comp Physiol 2021; 321:R982-R989. [PMID: 34755553 PMCID: PMC8714814 DOI: 10.1152/ajpregu.00169.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 11/22/2022]
Abstract
Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARH) are a diverse group of neurons that project widely to different brain regions. It is unknown how this small population of neurons organizes its efferent projections. In this study, we hypothesized that individual ARH POMC neurons exclusively innervate select target regions. To investigate this hypothesis, we first verified that only a fraction of ARH POMC neurons innervate the lateral hypothalamus (LH), the paraventricular nucleus of the hypothalamus (PVN), the periaqueductal gray (PAG), or the ventral tegmental area (VTA) using the retrograde tracer cholera toxin B (CTB). Next, two versions of CTB conjugated to distinct fluorophores were injected bilaterally into two of the regions such that PVN and VTA, PAG and VTA, or LH and PVN received tracers simultaneously. These pairs of target sites were chosen based on function and location. Few individual ARH POMC neurons projected to two brain regions at once, suggesting that there are ARH POMC neuron subpopulations organized by their efferent projections. We also investigated whether increasing the activity of POMC neurons could increase the number of ARH POMC neurons labeled with CTB, implying an increase in new synaptic connections to downstream regions. However, chemogenetic enhancement of POMC neuron activity did not increase retrograde tracing of CTB back to ARH POMC neurons from either the LH, PVN, or VTA. Overall, subpopulations of ARH POMC neurons with distinct efferent projections may serve as a way for the POMC population to organize its many functions.
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Affiliation(s)
- Marissa J Metz
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Caitlin M Daimon
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Connie M King
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Andrew R Rau
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Shane T Hentges
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
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19
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Caron A, Jane Michael N. New Horizons: Is Obesity a Disorder of Neurotransmission? J Clin Endocrinol Metab 2021; 106:e4872-e4886. [PMID: 34117881 DOI: 10.1210/clinem/dgab421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Indexed: 11/19/2022]
Abstract
Obesity is a disease of the nervous system. While some will view this statement as provocative, others will take it as obvious. Whatever our side is, the pharmacology tells us that targeting the nervous system works for promoting weight loss. It works, but at what cost? Is the nervous system a safe target for sustainable treatment of obesity? What have we learned-and unlearned-about the central control of energy balance in the last few years? Herein we provide a thought-provoking exploration of obesity as a disorder of neurotransmission. We discuss the state of knowledge on the brain pathways regulating energy homeostasis that are commonly targeted in anti-obesity therapy and explore how medications affecting neurotransmission such as atypical antipsychotics, antidepressants, and antihistamines relate to body weight. Our goal is to provide the endocrine community with a conceptual framework that will help expending our understanding of the pathophysiology of obesity, a disease of the nervous system.
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Affiliation(s)
- Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
- Montreal Diabetes Research Center, Montreal, QC, Canada
| | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, QC, Canada
- Quebec Heart and Lung Institute, Quebec City, QC, Canada
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Quaresma PGF, Wasinski F, Mansano NS, Furigo IC, Teixeira PDS, Gusmao DO, Frazao R, Donato J. Leptin Receptor Expression in GABAergic Cells is Not Sufficient to Normalize Metabolism and Reproduction in Mice. Endocrinology 2021; 162:6353267. [PMID: 34402859 DOI: 10.1210/endocr/bqab168] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Indexed: 12/12/2022]
Abstract
Previous studies indicate that leptin receptor (LepR) expression in GABAergic neurons is necessary for the biological effects of leptin. However, it is not clear whether LepR expression only in GABAergic neurons is sufficient to prevent the metabolic and neuroendocrine imbalances caused by LepR deficiency. In the present study, we produced mice that express the LepR exclusively in GABAergic cells (LepRVGAT mice) and compared them with wild-type (LepR+/+) and LepR-deficient (LepRNull/Null) mice. Although LepRVGAT mice showed a pronounced reduction in body weight and fat mass, as compared with LepRNull/Null mice, male and female LepRVGAT mice exhibited an obese phenotype relative to LepR+/+ mice. Food intake was normalized in LepRVGAT mice; however, LepRVGAT mice still exhibited lower energy expenditure in both sexes and reduced ambulatory activity in the females, compared with LepR+/+ mice. The acute anorexigenic effect of leptin and hedonic feeding were normalized in LepRVGAT mice despite the hyperleptinemia they present. Although LepRVGAT mice showed improved glucose homeostasis compared with LepRNull/Null mice, both male and female LepRVGAT mice exhibited insulin resistance. In contrast, LepR expression only in GABAergic cells was sufficient to normalize the density of agouti-related peptide (AgRP) and α-MSH immunoreactive fibers in the paraventricular nucleus of the hypothalamus. However, LepRVGAT mice exhibited reproductive dysfunctions, including subfertility in males and alterations in the estrous cycle of females. Taken together, our findings indicate that LepR expression in GABAergic cells, although critical to the physiology of leptin, is insufficient to normalize several metabolic aspects and the reproductive function in mice.
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Affiliation(s)
- Paula G F Quaresma
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Frederick Wasinski
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Naira S Mansano
- Departamento de Anatomia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, SP, 05508-900, Brazil
| | - Isadora C Furigo
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Pryscila D S Teixeira
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Daniela O Gusmao
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Renata Frazao
- Departamento de Anatomia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, SP, 05508-900, Brazil
| | - Jose Donato
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
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21
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Saucisse N, Mazier W, Simon V, Binder E, Catania C, Bellocchio L, Romanov RA, Léon S, Matias I, Zizzari P, Quarta C, Cannich A, Meece K, Gonzales D, Clark S, Becker JM, Yeo GSH, Fioramonti X, Merkle FT, Wardlaw SL, Harkany T, Massa F, Marsicano G, Cota D. Functional heterogeneity of POMC neurons relies on mTORC1 signaling. Cell Rep 2021; 37:109800. [PMID: 34644574 DOI: 10.1016/j.celrep.2021.109800] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 07/21/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
Hypothalamic pro-opiomelanocortin (POMC) neurons are known to trigger satiety. However, these neuronal cells encompass heterogeneous subpopulations that release γ-aminobutyric acid (GABA), glutamate, or both neurotransmitters, whose functions are poorly defined. Using conditional mutagenesis and chemogenetics, we show that blockade of the energy sensor mechanistic target of rapamycin complex 1 (mTORC1) in POMC neurons causes hyperphagia by mimicking a cellular negative energy state. This is associated with decreased POMC-derived anorexigenic α-melanocyte-stimulating hormone and recruitment of POMC/GABAergic neurotransmission, which is restrained by cannabinoid type 1 receptor signaling. Electrophysiology and optogenetic studies further reveal that pharmacological blockade of mTORC1 simultaneously activates POMC/GABAergic neurons and inhibits POMC/glutamatergic ones, implying that the functional specificity of these subpopulations relies on mTORC1 activity. Finally, POMC neurons with different neurotransmitter profiles possess specific molecular signatures and spatial distribution. Altogether, these findings suggest that mTORC1 orchestrates the activity of distinct POMC neurons subpopulations to regulate feeding behavior.
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Affiliation(s)
- Nicolas Saucisse
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Wilfrid Mazier
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Vincent Simon
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Elke Binder
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Caterina Catania
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Luigi Bellocchio
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Roman A Romanov
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria
| | - Stéphane Léon
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Isabelle Matias
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Philippe Zizzari
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Carmelo Quarta
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Astrid Cannich
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Delphine Gonzales
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Samantha Clark
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Julia M Becker
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Giles S H Yeo
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Xavier Fioramonti
- NutriNeuro, UMR 1286 INRAE, Bordeaux University, Bordeaux INP, F-33000 Bordeaux, France
| | - Florian T Merkle
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK; Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge Biomedical Campus, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Sharon L Wardlaw
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Tibor Harkany
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria; Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Federico Massa
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Giovanni Marsicano
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France
| | - Daniela Cota
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France.
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22
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Li Y, Wang X, Lu L, Wang M, Zhai Y, Tai X, Dilimulati D, Lei X, Xu J, Zhang C, Fu Y, Qu S, Li Q, Zhang C. Identification of novel GPCR partners of the central melanocortin signaling. Mol Metab 2021; 53:101317. [PMID: 34400348 PMCID: PMC8458986 DOI: 10.1016/j.molmet.2021.101317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/03/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Homo- or heterodimerization of G protein-coupled receptors (GPCRs) generally affects the normal functioning of these receptors and mediates the responses to a variety of physiological stimuli in vivo. It is well known that melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) are key regulators of appetite and energy homeostasis in the central nervous system. However, the GPCR partners of MC3R and MC4R are not well understood. Our objective is to analyze single cell RNA-seq datasets of the hypothalamus to explore and identify novel GPCR partners of MC3R and MC4R and examine the pharmacological effect on the downstream signal transduction and membrane translocation of melanocortin receptors. METHODS We conducted an integrative analysis of multiple single cell RNA-seq datasets to reveal the expression pattern and correlation of GPCR families in the mouse hypothalamus. The emerging GPCRs with important metabolic functions were selected for cloning and co-immunoprecipitation validation. The positive GPCR partners were then tested for the pharmacological activation, competitive binding assay and surface translocation ELISA experiments. RESULTS Based on the expression pattern of GPCRs and their function enrichment results, we narrowed down the range of potential GPCR interaction with MC3R and MC4R for further confirmation. Co-immunoprecipitation assay verified 23 and 32 novel GPCR partners that interacted with MC3R and MC4R in vitro. The presence of these GPCR partners exhibited different effects in the physiological regulation and signal transduction of MC3R and MC4R. CONCLUSIONS This work represented the first large-scale screen for the functional GPCR complex of central melanocortin receptors and defined a composite metabolic regulatory GPCR network of the hypothalamic nucleuses.
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Affiliation(s)
- Yunpeng Li
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiaozhu Wang
- Shanghai Key Laboratory of Signaling and Disease Research, Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Shanghai East Hospital, Tongji University, Shanghai, China.
| | - Liumei Lu
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yue Zhai
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiaolu Tai
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Diliqingna Dilimulati
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiaowei Lei
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jing Xu
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Cong Zhang
- Department of Plastic and Reconstructive Surgery, Shanghai Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yanbin Fu
- Department of Plastic and Reconstructive Surgery, Shanghai Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shen Qu
- Department of Endocrinology and Metabolism, National Metabolic Management Center, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.
| | - Qingfeng Li
- Department of Plastic and Reconstructive Surgery, Shanghai Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Chao Zhang
- Department of Plastic and Reconstructive Surgery, Shanghai Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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23
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Leyrer-Jackson JM, Hood LE, Olive MF. Alcohol consumption preferentially activates a subset of pro-opiomelanocortin (POMC) producing neurons targeting the amygdala. Neuropharmacology 2021; 195:108674. [PMID: 34153315 DOI: 10.1016/j.neuropharm.2021.108674] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/26/2021] [Accepted: 06/12/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Alcohol abuse is a worldwide public health concern and leads to an estimated 90,000 alcohol-related deaths in the United States annually. Alcohol may promote its euphoric and motivational effects, in part, by activating the endogenous opioid system. Pro-opiomelanocortin (POMC) producing neurons located within the arcuate nucleus (ArcN) of the hypothalamus make up one circuit of the endogenous opioid system, and heavily projects to reward-related brain areas such as the amygdala, nucleus accumbens (NAc) and ventral tegmental area (VTA). POMC producing neurons release β-endorphin and other peptides that target opioid receptors within reward areas to elicit their associated rewarding effects. Here we explore ArcN POMC neuronal activation, as assessed via FosB expression, following alcohol consumption to determine whether activation varied within subsets of ArcN POMC projection neurons targeting different reward-related areas. METHODS Fluorescent retrobeads were used to label ArcN POMC projection neurons targeting the NAc, amygdala and VTA in POMC-cre mice expressing the reporter tdTomato. Animals (n = 57) were then allowed to voluntarily consume alcohol or water using the drinking-in-the-dark (DID) paradigm, and sacrificed for immunohistochemistry to examine FosB expression within ArcN POMC neurons. RESULTS Female mice displayed escalation of alcohol intake across DID sessions, whereas males did not. A greater percent of ArcN POMC neurons target the amygdala over the NAc and VTA, and alcohol consumption preferentially activated ArcN POMC neurons targeting the amygdala over other areas. CONCLUSION These findings highlight a novel aspect alcohol-induced activation of the endogenous opioid system, whereby alcohol activates a specific subpopulation of ArcN POMC producing neurons that project primarily to the amygdala.
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Affiliation(s)
| | - Lauren E Hood
- Department of Psychology, Arizona State University, Tempe, AZ, 85281, USA
| | - M Foster Olive
- Department of Psychology, Arizona State University, Tempe, AZ, 85281, USA
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24
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Reported Benefits of Low-Dose Naltrexone Appear to Be Independent of the Endogenous Opioid System Involving Proopiomelanocortin Neurons and β-Endorphin. eNeuro 2021; 8:ENEURO.0087-21.2021. [PMID: 34031099 PMCID: PMC8211470 DOI: 10.1523/eneuro.0087-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 05/08/2021] [Accepted: 05/14/2021] [Indexed: 11/25/2022] Open
Abstract
Naltrexone is an opioid receptor antagonist approved for the treatment of alcohol and opioid use disorders at doses of 50–150 mg/d. Naltrexone has also been prescribed at much lower doses (3–6 mg/d) for the off-label treatment of inflammation and pain. Currently, a compelling mechanistic explanation for the reported efficacy of low-dose naltrexone (LDN) is lacking and none of the proposed mechanisms can explain patient reports of improved mood and sense of well-being. Here, we examined the possibility that LDN might alter the activity of the endogenous opioid system involving proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARH) in male and female mice. Known actions of POMC neurons could account for changes in pain perception and mood. However, using electrophysiologic, imaging and peptide measurement approaches, we found no evidence for such a mechanism. LDN did not change the sensitivity of opioid receptors regulating POMC neurons, the production of the β-endorphin precursor Pomc mRNA, nor the release of β-endorphin into plasma. Spontaneous postsynaptic currents (sPSCs) onto POMC neurons were slightly decreased after LDN treatment and GCaMP fluorescent signal, a proxy for intracellular calcium levels, was slightly increased. However, LDN treatment did not appear to change POMC neuron firing rate, resting membrane potential, nor action potential threshold. Therefore, LDN appears to have only slight effects on POMC neurons that do not translate to changes in intrinsic excitability or baseline electrical activity and mechanisms beyond POMC neurons and altered opioid receptor sensitivity should continue to be explored.
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25
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Quarta C, Claret M, Zeltser LM, Williams KW, Yeo GSH, Tschöp MH, Diano S, Brüning JC, Cota D. POMC neuronal heterogeneity in energy balance and beyond: an integrated view. Nat Metab 2021; 3:299-308. [PMID: 33633406 PMCID: PMC8085907 DOI: 10.1038/s42255-021-00345-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/13/2021] [Indexed: 01/31/2023]
Abstract
Hypothalamic AgRP and POMC neurons are conventionally viewed as the yin and yang of the body's energy status, since they act in an opposite manner to modulate appetite and systemic energy metabolism. However, although AgRP neurons' functions are comparatively well understood, a unifying theory of how POMC neuronal cells operate has remained elusive, probably due to their high level of heterogeneity, which suggests that their physiological roles might be more complex than initially thought. In this Perspective, we propose a conceptual framework that integrates POMC neuronal heterogeneity with appetite regulation, whole-body metabolic physiology and the development of obesity. We highlight emerging evidence indicating that POMC neurons respond to distinct combinations of interoceptive signals and food-related cues to fine-tune divergent metabolic pathways and behaviours necessary for survival. The new framework we propose reflects the high degree of developmental plasticity of this neuronal population and may enable progress towards understanding of both the aetiology and treatment of metabolic disorders.
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Affiliation(s)
- Carmelo Quarta
- University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, INSERM U1215, Bordeaux, France
| | - Marc Claret
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red (CIBER), Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Lori M Zeltser
- Naomi Berrie Diabetes Center, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Kevin W Williams
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität, Munich, Germany
| | - Sabrina Diano
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, NY, USA
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY, USA
| | - Jens C Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
- Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- National Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Daniela Cota
- University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, INSERM U1215, Bordeaux, France.
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26
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Landry T, Li P, Shookster D, Jiang Z, Li H, Laing BT, Bunner W, Langton T, Tong Q, Huang H. Centrally circulating α-klotho inversely correlates with human obesity and modulates arcuate cell populations in mice. Mol Metab 2020; 44:101136. [PMID: 33301986 PMCID: PMC7777546 DOI: 10.1016/j.molmet.2020.101136] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/20/2022] Open
Abstract
Objective Our laboratory recently identified the centrally circulating α-klotho protein as a novel hypothalamic regulator of food intake and glucose metabolism in mice. The current study aimed to investigate novel molecular effectors of central α-klotho in the arcuate nucleus of the hypothalamus (ARC), while further deciphering its role regulating energy balance in both humans and mice. Methods Cerebrospinal fluid (CSF) was collected from 22 adults undergoing lower limb orthopedic surgeries, and correlations between body weight and α-klotho were determined using an α-klotho enzyme-linked immunosorbent assay (ELISA) kit. To investigate the effects of α-klotho on energy expenditure (EE), 2-day intracerebroventricular (ICV) treatment was performed in diet-induced obesity (DIO) mice housed in TSE Phenomaster indirect calorimetry metabolic cages. Immunohistochemical staining for cFOS and patch clamp electrophysiology were used to determine the effects of central α-klotho on proopiomelanocortin (POMC) and tyrosine hydroxylase (TH) neurons. Additional stainings were performed to determine novel roles for central α-klotho to regulate non-neuronal cell populations in the ARC. Lastly, ICV pretreatment with fibroblast growth factor receptor (FGFR) or PI3kinase inhibitors was performed to determine the intracellular signaling involved in α-klotho-mediated regulation of ARC nuclei. Results Obese/overweight human subjects had significantly lower CSF α-klotho concentrations compared to lean counterparts (1,044 ± 251 vs. 1616 ± 218 pmol/L, respectively). Additionally, 2 days of ICV α-klotho treatment increased EE in DIO mice. α-Klotho had no effects on TH neuron activity but elicited varied responses in POMC neurons, with 44% experiencing excitatory and 56% experiencing inhibitory effects. Inhibitor experiments identified an α-klotho→FGFR→PI3kinase signaling mechanism in the regulation of ARC POMC and NPY/AgRP neurons. Acute ICV α-klotho treatment also increased phosphorylated ERK in ARC astrocytes via FGFR signaling. Conclusion Our human CSF data provide the first evidence that impaired central α-klotho function may be involved in the pathophysiology of obesity. Furthermore, results in mouse models identify ARC POMC neurons and astrocytes as novel molecular effectors of central α-klotho. Overall, the current study highlights prominent roles of α-klotho→FGFR→PI3kinase signaling in the homeostatic regulation of ARC neurons and whole-body energy balance. Human CSF α-klotho concentrations exhibit a strong, inverse correlation with body weight and BMI. ICV α-klotho treatment increases energy expenditure in DIO mice. α-Klotho.→FGFR→PI3kinase signaling modulates ARC NPY/AgRP and POMC neurons. α-Klotho.→FGFR→ERK signaling regulates ARC astrocytes.
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Affiliation(s)
- Taylor Landry
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Peixin Li
- Department of Comprehensive Surgery, Medical and Health Center, Beijing Friendship Hospital, Capital Medical University, Beijing, PR China
| | - Daniel Shookster
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Zhiying Jiang
- Brown Foundation Institute of Molecular Medicine of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Hongli Li
- Brown Foundation Institute of Molecular Medicine of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Brenton Thomas Laing
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Wyatt Bunner
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Theodore Langton
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Hu Huang
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA; Department of Physiology, East Carolina University, Greenville, NC, USA.
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27
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Kwon E, Jo YH. Activation of the ARC POMC→MeA Projection Reduces Food Intake. Front Neural Circuits 2020; 14:595783. [PMID: 33250721 PMCID: PMC7674918 DOI: 10.3389/fncir.2020.595783] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/09/2020] [Indexed: 02/05/2023] Open
Abstract
Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) plays an essential role in the control of food intake and energy expenditure. Melanocortin-4 receptors (MC4Rs) are expressed in key areas that are implicated in regulating energy homeostasis. Although the importance of MC4Rs in the paraventricular hypothalamus (PVH) has been well documented, the role of MC4Rs in the medial amygdala (MeA) on feeding remains controversial. In this study, we specifically examine the role of a novel ARCPOMC→MeA neural circuit in the regulation of short-term food intake. To map a local melanocortinergic neural circuit, we use monosynaptic anterograde as well as retrograde viral tracers and perform double immunohistochemistry to determine the identity of the neurons receiving synaptic input from POMC neurons in the ARC. To investigate the role of the ARCPOMC→MeA projection on feeding, we optogenetically stimulate channelrhodopsin-2 (ChR2)-expressing POMC fibers in the MeA. Anterograde viral tracing studies reveal that ARC POMC neurons send axonal projections to estrogen receptor-α (ER-α)- and MC4R-expressing neurons in the MeA. Retrograde viral tracing experiments show that the neurons projecting to the MeA is located mainly in the lateral part of the ARC. Optogenetic stimulation of the ARCPOMC→MeA pathway reduces short-term food intake. This anorectic effect is blocked by treatment with the MC4R antagonist SHU9119. In addition to the melanocortinergic local circuits within the hypothalamus, this extrahypothalamic ARCPOMC→MeA neural circuit would play a role in regulating short-term food intake.
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Affiliation(s)
- Eunjin Kwon
- The Fleischer Institute for Diabetes and Metabolism, Bronx, NY, United States
- Division of Endocrinology, Department of Medicine, Bronx, NY, United States
| | - Young-Hwan Jo
- The Fleischer Institute for Diabetes and Metabolism, Bronx, NY, United States
- Division of Endocrinology, Department of Medicine, Bronx, NY, United States
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
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Rau AR, King CM, Hentges ST. Disruption of GABA or glutamate release from POMC neurons in the adult mouse does not affect metabolic end points. Am J Physiol Regul Integr Comp Physiol 2020; 319:R592-R601. [PMID: 32936679 DOI: 10.1152/ajpregu.00180.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Proopiomelanocortin (POMC) neurons contribute to the regulation of many physiological processes; the majority of which have been attributed to the release of peptides produced from the POMC prohormone such as α-MSH, which plays key roles in food intake and metabolism. However, it is now clear that POMC neurons also release amino acid transmitters that likely contribute to the overall function of POMC cells. Recent work indicates that constitutive deletion of these transmitters can affect metabolic phenotypes, but also that the expression of GABAergic or glutamatergic markers changes throughout development. The goal of the present study was to determine whether the release of glutamate or GABA from POMC neurons in the adult mouse contributes notably to energy balance regulation. Disturbed release of glutamate or GABA specifically from POMC neurons in adult mice was achieved using a tamoxifen-inducible Cre construct (Pomc-CreERT2) expressed in mice also carrying floxed versions of Slc17a6 (vGlut2) or Gad1 and Gad2, encoding the vesicular glutamate transporter type 2 and GAD67 and GAD65 proteins, respectively. All mice in the experiments received tamoxifen injections, but control mice lacked the tamoxifen-inducible Cre sequence. Body weight was unchanged in Gad1- and Gad2- or vGlut2-deleted female and male mice. Additionally, no significant differences in glucose tolerance or refeeding after an overnight fast were observed. These data collectively suggest that the release of GABA or glutamate from POMC neurons in adult mice does not significantly contribute to the metabolic parameters tested here. In light of prior work, the data also suggest that amino acid transmitter release from POMC cells may contribute to separate functions in the adult versus the developing mouse.
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Affiliation(s)
- Andrew R Rau
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Connie M King
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Shane T Hentges
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
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29
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Dunigan AI, Swanson AM, Olson DP, Roseberry AG. Whole-brain efferent and afferent connectivity of mouse ventral tegmental area melanocortin-3 receptor neurons. J Comp Neurol 2020; 529:1157-1183. [PMID: 32856297 DOI: 10.1002/cne.25013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/10/2020] [Accepted: 08/14/2020] [Indexed: 12/27/2022]
Abstract
The mesolimbic dopamine (DA) system is involved in the regulation of multiple behaviors, including feeding, and evidence demonstrates that the melanocortin system can act on the mesolimbic DA system to control feeding and other behaviors. The melanocortin-3 receptor (MC3R) is an important component of the melanocortin system, but its overall role is poorly understood. Because MC3Rs are highly expressed in the ventral tegmental area (VTA) and are likely to be the key interaction point between the melanocortin and mesolimbic DA systems, we set out to identify both the efferent projection patterns of VTA MC3R neurons and the location of the neurons providing afferent input to them. VTA MC3R neurons were broadly connected to neurons across the brain but were strongly connected to a discrete set of brain regions involved in the regulation of feeding, reward, and aversion. Surprisingly, experiments using monosynaptic rabies virus showed that proopiomelanocortin (POMC) and agouti-related protein (AgRP) neurons in the arcuate nucleus made few direct synapses onto VTA MC3R neurons or any of the other major neuronal subtypes in the VTA, despite being extensively labeled by general retrograde tracers injected into the VTA. These results greatly contribute to our understanding of the anatomical interactions between the melanocortin and mesolimbic systems and provide a foundation for future studies of VTA MC3R neurons and the circuits containing them in the control of feeding and other behaviors.
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Affiliation(s)
- Anna I Dunigan
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Andrew M Swanson
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Aaron G Roseberry
- Department of Biology, Georgia State University, Atlanta, Georgia, USA.,Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
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Hypothalamic extended synaptotagmin-3 contributes to the development of dietary obesity and related metabolic disorders. Proc Natl Acad Sci U S A 2020; 117:20149-20158. [PMID: 32747560 DOI: 10.1073/pnas.2004392117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The C2 domain containing protein extended synaptotagmin (E-Syt) plays important roles in both lipid homeostasis and the intracellular signaling; however, its role in physiology remains largely unknown. Here, we show that hypothalamic E-Syt3 plays a critical role in diet-induced obesity (DIO). E-Syt3 is characteristically expressed in the hypothalamic nuclei. Whole-body or proopiomelanocortin (POMC) neuron-specific ablation of E-Syt3 ameliorated DIO and related comorbidities, including glucose intolerance and dyslipidemia. Conversely, overexpression of E-Syt3 in the arcuate nucleus moderately promoted food intake and impaired energy expenditure, leading to increased weight gain. Mechanistically, E-Syt3 ablation led to increased processing of POMC to α-melanocyte-stimulating hormone (α-MSH), increased activities of protein kinase C and activator protein-1, and enhanced expression of prohormone convertases. These findings reveal a previously unappreciated role for hypothalamic E-Syt3 in DIO and related metabolic disorders.
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Ethanol has concentration-dependent effects on hypothalamic POMC neuronal excitability. Alcohol 2020; 86:103-112. [PMID: 32304714 DOI: 10.1016/j.alcohol.2020.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 11/21/2022]
Abstract
Alcohol abuse is a worldwide public health concern, yet the precise molecular targets of alcohol in the brain are still not fully understood. Alcohol may promote its euphoric and motivational effects, in part, by activating the endogenous opioid system. One particular component of this system consists of pro-opiomelanocortin (POMC) -producing neurons in the arcuate nucleus (ArcN) of the hypothalamus, which project to reward-related brain areas. To identify the physiological effects of ethanol on ArcN POMC neurons, we utilized whole cell patch-clamp recordings and bath application of ethanol (5-40 mM) to identify alterations in spontaneous baseline activity, rheobase, spiking characteristics, or intrinsic neuronal properties. We found that 10 mM ethanol increased the number of depolarization-induced spikes in the majority of recorded cells, whereas higher concentrations of ethanol (20-40 mM) decreased the number of spikes. Interestingly, we found that basal firing rates of ArcN POMC neurons may predict physiological responding to ethanol. Rheobase and spontaneous activity, measured by spontaneous excitatory post-synaptic potentials (EPSPs) at rest, were unchanged after exposure to ethanol, regardless of concentration. These results suggest that ethanol has concentration-dependent modulatory effects on ArcN POMC neuronal activity, which may be relevant to treatments for alcohol use disorders that target endogenous opioid systems.
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Trotta M, Bello EP, Alsina R, Tavella MB, Ferrán JL, Rubinstein M, Bumaschny VF. Hypothalamic Pomc expression restricted to GABAergic neurons suppresses Npy overexpression and restores food intake in obese mice. Mol Metab 2020; 37:100985. [PMID: 32311511 PMCID: PMC7292867 DOI: 10.1016/j.molmet.2020.100985] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 12/28/2022] Open
Abstract
Objective Hypothalamic arcuate proopiomelanocortin (Arc-POMC) neurons are involved in different physiological processes such as the regulation of energy balance, glucose homeostasis, and stress-induced analgesia. Since these neurons heterogeneously express different biological markers and project to many hypothalamic and extrahypothalamic areas, it is proposed that Arc-POMC neurons could be classified into different subpopulations having diverse physiological roles. The aim of the present study was to characterize the contribution of the subpopulation of Arc-POMC neurons cosecreting gamma-aminobutyric acid (GABA) neurotransmitter in the control of energy balance. Methods Arc-Pomc expression restricted to GABAergic-POMC neurons was achieved by crossing a reversible Pomc-deficient mouse line (arcPomc−) with a tamoxifen-inducible Gad2-CreER transgenic line. Pomc expression was rescued in the compound arcPomc−/−:Gad2-CreER female and male mice by tamoxifen treatment at postnatal days 25 (P25) or 60 (P60), and body weight, daily food intake, fasting glycemia, and fasting-induced hyperphagia were measured. POMC recovery was quantified by immunohistochemistry and semiquantitative RT-PCR. Neuropeptide Y (NPY) and GABAergic neurons were identified by in situ hybridization. Arc-POMC neurons projecting to the dorsomedial hypothalamic nucleus (DMH) were studied by stereotactic intracerebral injection of fluorescent retrobeads into the DMH. Results Tamoxifen treatment of arcPomc−/−:Gad2-CreER mice at P60 resulted in Pomc expression in ∼23–25% of Arc-POMC neurons and ∼15–23% of Pomc mRNA levels, compared to Gad2-CreER control mice. Pomc rescue in GABAergic-POMC neurons at P60 normalized food intake, glycemia, and fasting-induced hyperphagia, while significantly reducing body weight. Energy balance was also improved in arcPomc−/−:Gad2-CreER mice treated with tamoxifen at P25. Distribution analysis of rescued POMC immunoreactive fibers revealed that the DMH is a major target site of GABAergic-POMC neurons. Further, the expression of the orexigenic neuropeptide Y (NPY) in the DMH was increased in arcPomc−/− obese mice but was completely restored after Pomc rescue in arcPomc−/−:Gad2-CreER mice. Finally, we found that ∼75% of Arc-POMC neurons projecting to the DMH are GABAergic. Conclusions In the present study, we show that the expression of Pomc in the subpopulation of Arc-GABAergic-POMC neurons is sufficient to maintain normal food intake. In addition, we found that DMH-NPY expression is negatively correlated with Pomc expression in GABAergic-POMC neurons, suggesting that food intake may be regulated by an Arc-GABAergic-POMC → DMH-NPY pathway. The subpopulation of arcuate GABAergic-POMC neurons is sufficient to maintain normal food intake. Overweight induced by Pomc deficiency is reduced by arcuate Pomc expression restricted to GABAergic-POMC neurons. DMH-Npy overexpression in POMC-deficient mice is restored by Pomc rescue restricted to GABAergic-POMC neurons. Arcuate POMC neurons projecting to the DMH are mainly GABAergic.
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Affiliation(s)
- Milagros Trotta
- Grupo de Neurociencia de Sistemas, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO HOUSSAY), Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Paraguay 2155, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Estefanía Pilar Bello
- Grupo de Neurociencia de Sistemas, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO HOUSSAY), Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Paraguay 2155, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Ramiro Alsina
- Grupo de Neurociencia de Sistemas, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO HOUSSAY), Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Paraguay 2155, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina.
| | - María Belén Tavella
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina.
| | - José Luis Ferrán
- Department of Human Anatomy, School of Medicine, University of Murcia and IMIB-Arrixaca Institute, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain.
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina; Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Viviana Florencia Bumaschny
- Grupo de Neurociencia de Sistemas, Instituto de Fisiología y Biofísica "Bernardo Houssay" (IFIBIO HOUSSAY), Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Paraguay 2155, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina; Departamento de Ciencias Fisiológicas, Facultad de Medicina. Universidad de Buenos Aires, Paraguay 2155, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina.
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Connect-seq to superimpose molecular on anatomical neural circuit maps. Proc Natl Acad Sci U S A 2020; 117:4375-4384. [PMID: 32034095 DOI: 10.1073/pnas.1912176117] [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] [Indexed: 12/20/2022] Open
Abstract
The mouse brain contains about 75 million neurons interconnected in a vast array of neural circuits. The identities and functions of individual neuronal components of most circuits are undefined. Here we describe a method, termed "Connect-seq," which combines retrograde viral tracing and single-cell transcriptomics to uncover the molecular identities of upstream neurons in a specific circuit and the signaling molecules they use to communicate. Connect-seq can generate a molecular map that can be superimposed on a neuroanatomical map to permit molecular and genetic interrogation of how the neuronal components of a circuit control its function. Application of this method to hypothalamic neurons controlling physiological responses to fear and stress reveals subsets of upstream neurons that express diverse constellations of signaling molecules and can be distinguished by their anatomical locations.
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Johnson C, Hong W, Micevych P. Optogenetic Activation of β-Endorphin Terminals in the Medial Preoptic Nucleus Regulates Female Sexual Receptivity. eNeuro 2020; 7:ENEURO.0315-19.2019. [PMID: 31941660 PMCID: PMC6984809 DOI: 10.1523/eneuro.0315-19.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 01/13/2023] Open
Abstract
Estrogen and progesterone (P4) act in neural circuits to elicit lordosis, the stereotypical female sexual receptivity behavior. Estradiol acts through membrane receptors to rapidly activate a limbic-hypothalamic circuit consisting of the arcuate (ARH), medial preoptic (MPN), and ventromedial (VMH) nuclei of the hypothalamus. This initial activation results in a transient but necessary inhibition of lordosis, which appears to be a result of the release of β-endorphin (β-End) from proopiomelanocortin (POMC) terminals onto cells containing the µ-opioid receptor (MOR) in the MPN. To functionally examine the role of the MOR in the hypothalamic lordosis circuit, we transfected a channelrhodopsin (ChR2) adeno-associated virus into POMC cell bodies in the ARH and photostimulated POMC/β-End axon terminals in the MPN in sexually receptive female Pomc-cre mice. Following estrogen and P4 priming, sexual receptivity was assessed by measuring the lordosis quotient (LQ). Following an initial trial for sexual receptivity, mice were photostimulated during behavioral testing, and brains were processed for MOR immunohistochemistry (IHC). Photostimulation decreased the LQ only in ChR2-expressing Pomc-cre mice. Furthermore, photostimulation of ChR2 in POMC/β-End axon terminals in the MPN resulted in the internalization of MOR, indicating activation of the receptor. Our results suggest that the activation of the MOR in the MPN is sufficient to attenuate lordosis behavior in a hormone-primed, sexually receptive female mouse. These data support a central role of MOR in female sexual behavior, and provide further insight into the hypothalamus control of sexual receptivity.
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Affiliation(s)
- Caroline Johnson
- Department of Neurobiology David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Weizhe Hong
- Department of Neurobiology David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Paul Micevych
- Department of Neurobiology David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095
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Lu L, Ren Y, Yu T, Liu Z, Wang S, Tan L, Zeng J, Feng Q, Lin R, Liu Y, Guo Q, Luo M. Control of locomotor speed, arousal, and hippocampal theta rhythms by the nucleus incertus. Nat Commun 2020; 11:262. [PMID: 31937768 PMCID: PMC6959274 DOI: 10.1038/s41467-019-14116-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 12/13/2019] [Indexed: 01/06/2023] Open
Abstract
Navigation requires not only the execution of locomotor programs but also high arousal and real-time retrieval of spatial memory that is often associated with hippocampal theta oscillations. However, the neural circuits for coordinately controlling these important processes remain to be fully dissected. Here we show that the activity of the neuromedin B (NMB) neurons in the nucleus incertus (NI) is tightly correlated with mouse locomotor speed, arousal level, and hippocampal theta power. These processes are reversibly suppressed by optogenetic inhibition and rapidly promoted by optogenetic stimulation of NI NMB neurons. These neurons form reciprocal connections with several subcortical areas associated with arousal, theta oscillation, and premotor processing. Their projections to multiple downstream stations regulate locomotion and hippocampal theta, with the projection to the medial septum being particularly important for promoting arousal. Therefore, NI NMB neurons functionally impact the neural circuit for navigation control according to particular brains states. In addition to activation of locomotor circuits, navigation also requires regulation of arousal and spatial memory processes. Here the authors identify neuromedin B neurons in the nucleus incertus and their subcortical projections in controlling these various processes during navigation.
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Affiliation(s)
- Lihui Lu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Yuqi Ren
- School of Life Sciences, Peking University, Beijing, 100871, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Tao Yu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Zhixiang Liu
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Sice Wang
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China.,School of Life Sciences, Peking University, Beijing, 100871, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Lubin Tan
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Jiawei Zeng
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Qiru Feng
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Rui Lin
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Yang Liu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Qingchun Guo
- Chinese Institute for Brain Research, Beijing, 102206, China
| | - Minmin Luo
- School of Life Sciences, Tsinghua University, Beijing, 100084, China. .,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China. .,National Institute of Biological Sciences (NIBS), Beijing, 102206, China. .,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China. .,Chinese Institute for Brain Research, Beijing, 102206, China.
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Yonemochi N, Ardianto C, Ueda D, Kamei J, Ikeda H. GABAergic function in the lateral hypothalamus regulates feeding behavior: Possible mediation via orexin. Neuropsychopharmacol Rep 2019; 39:289-296. [PMID: 31618533 PMCID: PMC7292314 DOI: 10.1002/npr2.12080] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/22/2019] [Accepted: 09/24/2019] [Indexed: 11/17/2022] Open
Abstract
Aim The lateral hypothalamus (LH) is known as the hunger center, but the mechanisms through which the LH regulates food intake are unclear. Since GABA neurons are reported to project to the LH, the present study investigated the role of GABAergic function in the LH in the regulation of feeding behavior. Methods GABA levels in the LH were measured by in vivo microdialysis. Food intake after drug injection into the LH was measured every 1 hour for 4 hours. The mRNA levels were measured using RT‐PCR. Results Food intake significantly increased GABA levels in the LH, suggesting that food intake stimulates GABAergic function in the LH. Injection of the GABAA receptor agonist muscimol into the LH significantly inhibited food intake, whereas injection of the GABAA receptor antagonist bicuculline into the LH did not significantly affect food intake. The inhibitory effect of muscimol injected into the LH was blocked by co‐administration of bicuculline. These results indicate that the stimulation of GABAA receptors in the LH inhibits food intake. We next examined whether the stimulation of GABAA receptors affects hypothalamic neuropeptides that are known to regulate feeding behavior. The injection of muscimol significantly decreased preproorexin mRNA in the hypothalamus. Conclusion These results indicate that food intake activates GABAergic function in the LH, which terminates feeding behavior by stimulating GABAA receptors. Moreover, it is suggested that the stimulation of GABAA receptors in the LH reduces food intake through inhibition of orexin neurons. We investigated whether GABAergic function in the lateral hypothalamus (LH) regulates feeding behavior. We showed that food intake increased GABA levels in the LH in in vivo microdialysis and that the GABAA receptor agonist muscimol injected into the LH decreased food intake. These results suggest that food intake activates GABA neurons projecting to the LH, and it terminates feeding behavior through GABAA receptors.![]()
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Affiliation(s)
- Naomi Yonemochi
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Chrismawan Ardianto
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Daiki Ueda
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Junzo Kamei
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan.,Department of Biomolecular Pharmacology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Hiroko Ikeda
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
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mTORC1 and CB1 receptor signaling regulate excitatory glutamatergic inputs onto the hypothalamic paraventricular nucleus in response to energy availability. Mol Metab 2019; 28:151-159. [PMID: 31420305 PMCID: PMC6822143 DOI: 10.1016/j.molmet.2019.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE The hypothalamic paraventricular nucleus (PVN) is a key target of the melanocortin system, which orchestrates behavioral and metabolic responses depending on energy availability. The mechanistic target of rapamycin complex 1 (mTORC1) and the endocannabinoid type 1 receptor (CB1R) pathways are two key signaling systems involved in the regulation of energy balance whose activity closely depends upon energy availability. Here we tested the hypothesis that modulation of mTORC1 and CB1R signaling regulates excitatory glutamatergic inputs onto the PVN. METHODS Patch-clamp recordings in C57BL/6J mice, in mice lacking the mTORC1 component Rptor or CB1R in pro-opio-melanocortin (POMC) neurons, combined with pharmacology targeting mTORC1, the melanocortin receptor type 4 (MC4R), or the endocannabinoid system under chow or a hypercaloric diet. RESULTS Acute pharmacological inhibition of mTORC1 in C57BL/6J mice decreased glutamatergic inputs onto the PVN via a mechanism requiring modulation of MC4R, endocannabinoid 2-AG mobilization by PVN parvocellular neurons, and retrograde activation of presynaptic CB1R. Further electrophysiology studies using mice lacking mTORC1 activity or CB1R in POMC neurons indicated that the observed effects involved mTORC1 and CB1R-dependent regulation of glutamate release from POMC neurons. Finally, energy surfeit caused by hypercaloric high-fat diet feeding, rapidly and time-dependently altered the glutamatergic inputs onto parvocellular neurons and the ability of mTORC1 and CB1R signaling to modulate such excitatory activity. CONCLUSIONS These findings pinpoint the relationship between mTORC1 and endocannabinoid-CB1R signaling in the regulation of the POMC-mediated glutamatergic inputs onto PVN parvocellular neurons and its rapid alteration in conditions favoring the development of obesity.
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He Z, Gao Y, Lieu L, Afrin S, Cao J, Michael NJ, Dong Y, Sun J, Guo H, Williams KW. Direct and indirect effects of liraglutide on hypothalamic POMC and NPY/AgRP neurons - Implications for energy balance and glucose control. Mol Metab 2019; 28:120-134. [PMID: 31446151 PMCID: PMC6822260 DOI: 10.1016/j.molmet.2019.07.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 07/22/2019] [Accepted: 07/25/2019] [Indexed: 12/15/2022] Open
Abstract
Objective The long-acting glucagon-like peptide-1 receptor (GLP-1R) agonist, liraglutide, stimulates insulin secretion and efficiently suppresses food intake to reduce body weight. As such, liraglutide is growing in popularity in the treatment of diabetes and chronic weight management. Within the brain, liraglutide has been shown to alter the activity of hypothalamic proopiomelanocortin (POMC) and Neuropeptide Y/Agouti-related peptide (NPY/AgRP) neurons. Moreover, the acute activities of POMC and NPY neurons have been directly linked to feeding behavior, body weight, and glucose metabolism. Despite the increased usage of liraglutide and other GLP-1 analogues as diabetic and obesity interventions, the cellular mechanisms by which liraglutide alters the activity of metabolically relevant neuronal populations are poorly understood. Methods In order to resolve this issue, we utilized neuron-specific transgenic mouse models to identify POMC and NPY neurons for patch-clamp electrophysiology experiments. Results We found that liraglutide directly activated arcuate POMC neurons via TrpC5 channels, sharing a similar mechanistic pathway to the adipose-derived peptide leptin. Liraglutide also indirectly increases excitatory tone to POMC neurons. In contrast, liraglutide inhibited NPY/AgRP neurons through post-synaptic GABAA receptors and enhanced activity of pre-synaptic GABAergic neurons, which required both TrpC5 subunits and K-ATP channels. In support of an additive role of leptin and liraglutide in suppressing food intake, leptin potentiated the acute effects of liraglutide to activate POMC neurons. TrpC5 subunits in POMC neurons were also required for the intact pharmacological effects of liraglutide on food intake and body weight. Thus, the current study adds to recent work from our group and others, which highlight potential mechanisms to amplify the effects of GLP-1 agonists in vivo. Moreover, these data highlight multiple sites of action (both pre- and post-synaptic) for GLP-1 agonists on this circuit. Conclusions Taken together, our results identify critical molecular mechanisms linking GLP-1 analogues in arcuate POMC and NPY/AgRP neurons with metabolism. Liraglutide directly activates arcuate POMC neurons, while also increasing pre-synaptic excitatory inputs to POMC neurons. Leptin potentiates the acute effects of liraglutide to activate POMC neurons. Liraglutide indirectly inhibits arcuate NPY/AgRP neurons via presynaptic TrpC 5 subunits and KATP channels. TrpC5 subunits in POMC neurons are required for the intact pharmacological effects of liraglutide.
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Affiliation(s)
- Zhenyan He
- The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yong Gao
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Linh Lieu
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Sadia Afrin
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Jianhong Cao
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; Pi-wei Institute, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China
| | - Natalie J Michael
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yanbin Dong
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; Pi-wei Institute, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China
| | - Jia Sun
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Hongbo Guo
- The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Kevin W Williams
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA.
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GABAergic Inputs to POMC Neurons Originating from the Dorsomedial Hypothalamus Are Regulated by Energy State. J Neurosci 2019; 39:6449-6459. [PMID: 31235650 DOI: 10.1523/jneurosci.3193-18.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/21/2019] [Accepted: 06/10/2019] [Indexed: 02/06/2023] Open
Abstract
Neuronal circuits regulating hunger and satiety synthesize information encoding the energy state of the animal and translate those signals into motivated behaviors to meet homeostatic needs. Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus are activated by energy surfeits and inhibited by energy deficits. When activated, these cells inhibit food intake and facilitate weight loss. Conversely, decreased activity in POMC cells is associated with increased food intake and obesity. Circulating nutrients and hormones modulate the activity of POMC neurons over protracted periods of time. However, recent work indicates that calcium activity in POMC cells changes in response to food cues on times scales consistent with the rapid actions of amino acid transmitters. Indeed, the frequency of spontaneous IPSCs (sIPSCs) onto POMC neurons increases during caloric deficits. However, the afferent brain regions responsible for this inhibitory modulation are currently unknown. Here, through the use of brain region-specific deletion of GABA release in both male and female mice we show that neurons in the dorsomedial hypothalamus (DMH) are responsible for the majority of sIPSCs in POMC neurons as well as the fasting-induced increase in sIPSC frequency. Further, the readily releasable pool of GABA vesicles and the release probability of GABA is increased at DMH-to-POMC synapses following an overnight fast. Collectively these data provide evidence that DMH-to-POMC GABA circuitry conveys inhibitory neuromodulation onto POMC cells that is sensitive to the animal's energy state.SIGNIFICANCE STATEMENT Activation of proopiomelanocortin (POMC) cells signals satiety, whereas GABAergic cells in the dorsomedial hypothalamus (DMH) can increase food consumption. However, communication between these cells, particularly in response to changes in metabolic state, is unknown. Here, through targeted inhibition of DMH GABA release, we show that DMH neurons contribute a significant portion of spontaneously released GABA onto POMC cells and are responsible for increased GABAergic inhibition of POMC cells during fasting, likely mediated through increased release probability of GABA at DMH terminals. These data provide important information about inhibitory modulation of metabolic circuitry and provide a mechanism through which POMC neurons could be inhibited, or disinhibited, rapidly in response to food availability.
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Garduño J, Hernández-López S, Rolón DC, de la Cruz L, Hernández-Vázquez F, Reyes-Vaca A, Arenas I, Bravo-Martínez J, Garcia DE. Electrophysiological characterization of glucose sensing neurons in the hypothalamic arcuate nucleus of male rats. Neurosci Lett 2019; 703:168-176. [PMID: 30926375 DOI: 10.1016/j.neulet.2019.03.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/14/2019] [Accepted: 03/25/2019] [Indexed: 12/01/2022]
Abstract
The arcuate nucleus (ARC), located at the base of hypothalamus, contains two main populations of neurons involved in the regulation of food intake and energy expenditure. The NPY neurons are orexigenic and their activation stimulates food intake while the activation of POMC neurons promote the opposite effect. Several works have tried to identify these neurons based on their electrophysiological and pharmacological characteristics. However, the classification of ARC neurons is still inconclusive. In this work, glucose concentrations were changed within at physiological range, and the response of rat ARC neurons to this stimulus was used to identify them. Subsequently, the cells were classified on the basis of their passive and active electrophysiological properties. Finally, calcium imaging experiments were done to study the response of ARC neurons populations changing glucose concentrations. We found that NPY and putative POMC neurons can be distinguished based on their electrophysiological properties such as input resistance and firing pattern. Calcium imaging experiments confirmed the diversity of ARC neurons.
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Affiliation(s)
- Julieta Garduño
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico.
| | - Salvador Hernández-López
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
| | - Diego Castillo Rolón
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
| | - Lizbeth de la Cruz
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
| | - Fabiola Hernández-Vázquez
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, 04510, Mexico
| | - Arturo Reyes-Vaca
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
| | - Isabel Arenas
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
| | - Jorge Bravo-Martínez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
| | - David E Garcia
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), PO Box 70250, Ciudad de México, 04510, Mexico
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Jones GL, Wittmann G, Yokosawa EB, Yu H, Mercer AJ, Lechan RM, Low MJ. Selective Restoration of Pomc Expression in Glutamatergic POMC Neurons: Evidence for a Dynamic Hypothalamic Neurotransmitter Network. eNeuro 2019; 6:ENEURO.0400-18.2019. [PMID: 30957016 PMCID: PMC6449166 DOI: 10.1523/eneuro.0400-18.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/15/2019] [Accepted: 02/17/2019] [Indexed: 01/19/2023] Open
Abstract
Hypothalamic POMC deficiency leads to obesity and metabolic deficiencies, largely due to the loss of melanocortin peptides. However, POMC neurons in the arcuate nucleus (ARC) are comprised of glutamatergic and GABAergic subpopulations. The developmental program, relative proportion and function of these two subpopulations are unresolved. To test whether glutamatergic POMC neurons serve a distinct role in maintaining energy homeostasis, we activated Pomc expression Cre- dependently in Vglut2-expressing neurons of mice with conditionally silenced Pomc alleles. The Vglut2-Pomc restored mice had normal ARC Pomc mRNA levels, POMC immunoreactivity, as well as body weight and body composition at age 12 weeks. Unexpectedly, the cumulative total of Vglut2+ glutamatergic- and Gad67+ GABAergic-Pomc neurons detected by in situ hybridization (ISH) exceeded 100% in both Vglut2- Pomc restored and control mice, indicating that a subpopulation of Pomc neurons must express both neuronal markers. Consistent with this hypothesis, triple ISH of C57BL/6J hypothalami revealed that 35% of ARC Pomc neurons were selectively Gad67+, 21% were selectively Vglut2+, and 38% expressed both Gad67 and Vglut2. The single Gad67+ and Vglut2+Pomc neurons were most prevalent in the rostral ARC, while the Vglut2/Gad67+ dual-phenotype cells predominated in the caudal ARC. A lineage trace using Ai9-tdTomato reporter mice to label fluorescently all Vglut2-expressing neurons showed equal numbers of tdTomato+ and tdTomato- POMC immunoreactive neurons. Together, these data suggest that POMC neurons exhibit developmental plasticity in their expression of glutamatergic and GABAergic markers, enabling re-establishment of normal energy homeostasis in the Vglut2-Pomc restored mice.
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Affiliation(s)
- Graham L. Jones
- Neuroscience Graduate Program
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Gábor Wittmann
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA 02111
| | - Eva B. Yokosawa
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Hui Yu
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Aaron J. Mercer
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Ronald M. Lechan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA 02111
| | - Malcolm J. Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105
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Soletto L, Hernández-Balfagó S, Rocha A, Scheerer P, Kleinau G, Cerdá-Reverter JM. Melanocortin Receptor Accessory Protein 2-Induced Adrenocorticotropic Hormone Response of Human Melanocortin 4 Receptor. J Endocr Soc 2019; 3:314-323. [PMID: 30652132 PMCID: PMC6330173 DOI: 10.1210/js.2018-00370] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/03/2018] [Indexed: 12/11/2022] Open
Abstract
Melanocortin 4 receptor (MC4R), a canonical melanocyte-stimulating hormone receptor, is the main responsible for monogenic obesity in humans. Previous studies in fish and avian species showed that MC4R becomes an ACTH receptor after interaction with the melanocortin receptor accessory protein 2 (MRAP2). We show that human MC4R behaves in a similar way through its interaction with MRAP2. This evolutionary conservation of MRAP2-induced ligand selectivity supports a physiological role for the interaction with MC4R. Both proteins are coexpressed in the same hypothalamic neurons, providing an anatomical substrate and molecular mechanism for the central therapeutic actions of ACTH in the treatment of infantile spasms. These neurons may link the effects of stress on the energy balance independently of glucocorticoid secretion. The complex MC4R-MRAP2 throws light on the action of ACTH and, by extension, on the relay of stress-related information to additional biological systems.
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Affiliation(s)
- Lucia Soletto
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Castellón, Spain
| | - Sergio Hernández-Balfagó
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Castellón, Spain
| | - Ana Rocha
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Castellón, Spain
| | - Patrick Scheerer
- Group Protein X-ray Crystallography and Signal Transduction, Institute of Medical Physics and Biophysics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, D-10117 Berlin, Germany
| | - Gunnar Kleinau
- Group Protein X-ray Crystallography and Signal Transduction, Institute of Medical Physics and Biophysics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, D-10117 Berlin, Germany
| | - José Miguel Cerdá-Reverter
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Castellón, Spain
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Suyama S, Yada T. New insight into GABAergic neurons in the hypothalamic feeding regulation. J Physiol Sci 2018; 68:717-722. [PMID: 30003408 PMCID: PMC10717766 DOI: 10.1007/s12576-018-0622-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022]
Abstract
Several lines of study have suggested that GABA in the hypothalamic feeding center plays a role in promoting food intake. Recent studies revealed that not only NPY/AgRP neurons in the hypothalamic arcuate nucleus (ARC) that co-express GABA but also other GABAergic neurons act as an orexigenic. Here, we review the progress of studies on hypothalamic GABAergic neurons distributed in ARC, dorsomedial hypothalamus (DMH), and lateral hypothalamus (LH). Three advanced technologies have been applied and greatly contributed to the recent progress. Optogenetic (and chemogenetic) approaches map input and output pathways of particular subpopulations of GABAergic neurons. In vivo Ca2+ imaging using GRIN lens and GCaMP can correlate the activity of GABAergic neuron subpopulations with feeding behavior. Single-cell RNA-seq approach clarifies precise transcriptional profiles of GABAergic neuron subpopulations. These approaches have shown diversity of GABAergic neurons and the subpopulation-dependent role in feeding regulation.
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Affiliation(s)
- Shigetomo Suyama
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 320-0498, Japan.
| | - Toshihiko Yada
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 320-0498, Japan.
- Kansai Electric Power Medical Research Institute, 1-5-6 Minatojimaminamimachi, Chuou-ku, Kobe, 650-0047, Japan.
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Estradiol Drives the Anorexigenic Activity of Proopiomelanocortin Neurons in Female Mice. eNeuro 2018; 5:eN-NWR-0103-18. [PMID: 30310864 PMCID: PMC6179576 DOI: 10.1523/eneuro.0103-18.2018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/11/2018] [Accepted: 07/02/2018] [Indexed: 12/14/2022] Open
Abstract
Energy balance is regulated by anorexigenic proopiomelanocortin (POMC) and orexigenic neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons of the hypothalamic arcuate nucleus. POMC neurons make extensive projections and are thought to release both amino acid and peptide neurotransmitters. However, whether they communicate directly with NPY/AgRP neurons is debated. Initially, using single-cell RT-PCR, we determined that mouse POMCeGFP neurons express Slc17a6 (Vglut2) and Slc18a2 (Vmat2), but not Slc31a1 (Vgat) mRNA, suggesting glutamate and non-canonical GABA release. Quantitative (q)RT-PCR of POMCeGFP cells revealed that Vglut2 and Vmat2 expression was significantly increased in E2- versus oil-treated, ovariectomized (OVX) female mice. Since 17β-estradiol (E2) is anorexigenic, we hypothesized that an underlying mechanism is enhancement of POMC signaling. Therefore, we optogenetically stimulated POMC neurons in hypothalamic slices to examine evoked release of neurotransmitters onto NPY/AgRP neurons. Using brief light pulses, we primarily observed glutamatergic currents and, based on the paired pulse ratio (PPR), determined that release probability was higher in E2- versus oil-treated, OVX female, congruent with increased Vlgut2 expression. Moreover, bath perfusion of the Gq-coupled membrane estrogen receptor (ER) agonist STX recapitulated the effects of E2 treatment. In addition, high-frequency (20 Hz) stimulation generated a slow outward current that reversed near Ek+ and was antagonized by naloxone, indicative of β-endorphin release. Furthermore, individual NPY/AgRP neurons were found to express Oprm1, the transcript for μ-opioid receptor, and DAMGO, a selective agonist, elicited an outward current. Therefore, POMC excitability and neurotransmission are enhanced by E2, which would facilitate decreased food consumption through marked inhibition of NPY/AgRP neurons.
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D'Agostino G, Lyons D, Cristiano C, Lettieri M, Olarte-Sanchez C, Burke LK, Greenwald-Yarnell M, Cansell C, Doslikova B, Georgescu T, Martinez de Morentin PB, Myers MG, Rochford JJ, Heisler LK. Nucleus of the Solitary Tract Serotonin 5-HT 2C Receptors Modulate Food Intake. Cell Metab 2018; 28:619-630.e5. [PMID: 30146485 PMCID: PMC6371983 DOI: 10.1016/j.cmet.2018.07.017] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/12/2018] [Accepted: 07/27/2018] [Indexed: 12/14/2022]
Abstract
To meet the challenge to human health posed by obesity, a better understanding of the regulation of feeding is essential. Medications targeting 5-hydroxytryptamine (5-HT; serotonin) 2C receptors (htr2c; 5-HT2CR) improve obesity. Here we probed the functional significance of 5-HT2CRs specifically within the brainstem nucleus of the solitary tract (5-HT2CRNTS) in feeding behavior. Selective activation of 5-HT2CRNTS decreased feeding and was sufficient to mediate acute food intake reductions elicited by the 5-HT2CR agonist obesity medication lorcaserin. Similar to pro-opiomelanocortin neurons expressed within the hypothalamic arcuate nucleus (POMCARC), a subset of POMCNTS neurons co-expressed 5-HT2CRs and were activated by 5-HT2CR agonists. Knockdown of POMCNTS prevented the acute appetite-suppressive effect of lorcaserin, whereas POMCARC knockdown prevented the full anorectic effect. These data identify 5-HT2CRNTS as a sufficient subpopulation of 5-HT2CRs in reducing food intake when activated and reveal that 5-HT2CR agonist obesity medications require POMC within the NTS and ARC to reduce food intake.
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Affiliation(s)
- Giuseppe D'Agostino
- Rowett Institute, University of Aberdeen, Aberdeen, UK; Department of Pharmacology, University of Cambridge, Cambridge, UK.
| | - David Lyons
- Rowett Institute, University of Aberdeen, Aberdeen, UK
| | | | | | | | - Luke K Burke
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Megan Greenwald-Yarnell
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | | | | - Martin G Myers
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Lora K Heisler
- Rowett Institute, University of Aberdeen, Aberdeen, UK; Department of Pharmacology, University of Cambridge, Cambridge, UK.
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Neurobiological characteristics underlying metabolic differences between males and females. Prog Neurobiol 2018; 176:18-32. [PMID: 30194984 DOI: 10.1016/j.pneurobio.2018.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/22/2018] [Accepted: 09/01/2018] [Indexed: 12/24/2022]
Abstract
The hypothalamus is the main integrating center for metabolic control. Our understanding of how hypothalamic circuits function to control appetite and energy expenditure has increased dramatically in recent years, due to the rapid rise in the incidence of obesity and the search for effective treatments. Increasing evidence indicates that these treatments will most likely differ between males and females. Indeed, sex differences in metabolism have been demonstrated at various levels, including in two of the most studied neuronal populations involved in metabolic control: the anorexigenic proopiomelanocortin neurons and the orexigenic neuropeptide Y/Agouti-related protein neurons. Here we review what is known to date regarding the sex differences in these two neuronal populations, as well as other neuronal populations involved in metabolic control and glial cells.
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Rau AR, Hughes AR, Hentges ST. Various transgenic mouse lines to study proopiomelanocortin cells in the brain stem label disparate populations of GABAergic and glutamatergic neurons. Am J Physiol Regul Integr Comp Physiol 2018; 315:R144-R152. [PMID: 29590552 PMCID: PMC6087889 DOI: 10.1152/ajpregu.00047.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/06/2018] [Accepted: 03/16/2018] [Indexed: 12/31/2022]
Abstract
Products of the proopiomelanocortin (POMC) prohormone regulate aspects of analgesia, reward, and energy balance; thus, the neurons that produce POMC in the hypothalamus have received considerable attention. However, there are also cells in the nucleus of the solitary tract (NTS) that transcribe Pomc, although low levels of Pomc mRNA and relative lack of POMC peptide products in the adult mouse NTS have hindered the study of these cells. Therefore, studies of NTS POMC cells have largely relied on transgenic mouse lines. Here, we set out to determine the amino acid (AA) transmitter phenotype of NTS POMC neurons by using Pomc-Gfp transgenic mice to identify POMC cells. We found that cells expressing the green fluorescent protein (GFP) represent a mix of GABAergic and glutamatergic cells as indicated by Gad2 and vesicular Glut2 ( vGlut2) mRNA expression, respectively. We then examined the AA phenotype of POMC cells labeled by a Pomc-Cre transgene and found that these are also a mix of GABAergic and glutamatergic cells. However, the NTS cells labeled by the Gfp- and Cre-containing transgenes represented distinct populations of cells in three different Pomc-Cre mouse lines. Consistent with previous work, we were unable to reliably detect Pomc mRNA in the NTS despite clear expression in the hypothalamus. Thus, it was not possible to determine which transgenic tool most accurately identifies NTS cells that may express Pomc or release POMC peptides, although the results indicate the transgenic tools for study of these NTS neurons can label disparate populations of cells with varied AA phenotypes.
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Affiliation(s)
- Andrew R Rau
- Department of Biomedical Sciences, Colorado State University , Fort Collins, Colorado
| | - Alexander R Hughes
- Department of Biomedical Sciences, Colorado State University , Fort Collins, Colorado
| | - Shane T Hentges
- Department of Biomedical Sciences, Colorado State University , Fort Collins, Colorado
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Allison MB, Pan W, MacKenzie A, Patterson C, Shah K, Barnes T, Cheng W, Rupp A, Olson DP, Myers MG. Defining the Transcriptional Targets of Leptin Reveals a Role for Atf3 in Leptin Action. Diabetes 2018; 67:1093-1104. [PMID: 29535089 PMCID: PMC5961413 DOI: 10.2337/db17-1395] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/27/2018] [Indexed: 12/22/2022]
Abstract
Leptin acts via its receptor (LepRb) to modulate gene expression in hypothalamic LepRb-expressing neurons, thereby controlling energy balance and glucose homeostasis. Despite the importance of the control of gene expression in hypothalamic LepRb neurons for leptin action, the transcriptional targets of LepRb signaling have remained undefined because LepRb cells contribute a small fraction to the aggregate transcriptome of the brain regions in which they reside. We thus employed translating ribosome affinity purification followed by RNA sequencing to isolate and analyze mRNA from the hypothalamic LepRb neurons of wild-type or leptin-deficient (Lepob/ob) mice treated with vehicle or exogenous leptin. Although the expression of most of the genes encoding the neuropeptides commonly considered to represent the main targets of leptin action were altered only following chronic leptin deprivation, our analysis revealed other transcripts that were coordinately regulated by leptin under multiple treatment conditions. Among these, acute leptin treatment increased expression of the transcription factor Atf3 in LepRb neurons. Furthermore, ablation of Atf3 from LepRb neurons (Atf3LepRbKO mice) decreased leptin efficacy and promoted positive energy balance in mice. Thus, this analysis revealed the gene targets of leptin action, including Atf3, which represents a cellular mediator of leptin action.
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MESH Headings
- Activating Transcription Factor 3/agonists
- Activating Transcription Factor 3/chemistry
- Activating Transcription Factor 3/genetics
- Activating Transcription Factor 3/metabolism
- Animals
- Crosses, Genetic
- Diabetes Mellitus/drug therapy
- Diabetes Mellitus/metabolism
- Diabetes Mellitus/pathology
- Energy Metabolism/drug effects
- Female
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Hypothalamus/cytology
- Hypothalamus/drug effects
- Hypothalamus/metabolism
- Hypothalamus/pathology
- Leptin/analogs & derivatives
- Leptin/metabolism
- Leptin/pharmacology
- Leptin/therapeutic use
- Lipotropic Agents/pharmacology
- Lipotropic Agents/therapeutic use
- Male
- Mice, Knockout
- Mice, Mutant Strains
- Mice, Transgenic
- Nerve Tissue Proteins/agonists
- Nerve Tissue Proteins/chemistry
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- RNA, Messenger/chemistry
- RNA, Messenger/metabolism
- Receptors, Leptin/agonists
- Receptors, Leptin/genetics
- Receptors, Leptin/metabolism
- Sequence Analysis, RNA
- Signal Transduction/drug effects
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Affiliation(s)
- Margaret B Allison
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Warren Pan
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI
| | | | - Christa Patterson
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Kimi Shah
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Tammy Barnes
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Wenwen Cheng
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Alan Rupp
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - David P Olson
- Division of Pediatric Endocrinology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI
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49
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Calarco CA, Li Z, Taylor SR, Lee S, Zhou W, Friedman JM, Mineur YS, Gotti C, Picciotto MR. Molecular and cellular characterization of nicotinic acetylcholine receptor subtypes in the arcuate nucleus of the mouse hypothalamus. Eur J Neurosci 2018; 48:10.1111/ejn.13966. [PMID: 29791746 PMCID: PMC6251769 DOI: 10.1111/ejn.13966] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/26/2018] [Accepted: 05/09/2018] [Indexed: 12/22/2022]
Abstract
Nicotine, acting through nicotinic acetylcholine receptors (nAChRs), increases the firing rate of both orexigenic agouti-related peptide (AgRP) and anorexigenic pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC), yet nicotine and other nAChR agonists decrease food intake in mice. Viral-mediated knockdown of the β4 nAChR subunit in all neuronal cell types in the ARC prevents the nicotinic agonist cytisine from decreasing food intake, but it is not known whether the β4 subunit is selectively expressed in anorexigenic neurons or how other nAChR subtypes are distributed in this nucleus. Using translating ribosome affinity purification (TRAP) on ARC tissue from mice with ribosomes tagged in either AgRP or POMC cells, we examined nAChR subunit mRNA levels using real-time PCR. Both AgRP and POMC cells express a comparable panel of nAChR subunits with differences in α7 mRNA levels and a trend for difference in α4 levels, but no differences in β4 expression. Immunoprecipitation of assembled nAChRs revealed that the β4 subunit forms assembled channels with α3, β2 and α4, but not other subunits found in the ARC. Finally, using cell type-selective, virally delivered small hairpin RNAs targeting either the β4 or α7 subunit, we examined the contribution of each subunit in either AgRP or POMC cells to the behavioural response to nicotine, refining the understanding of nicotinic regulation of this feeding circuit. These experiments identify a more complex set of nAChRs expressed in ARC than in other hypothalamic regions. Thus, the ARC appears to be a particular target of nicotinic modulation.
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Affiliation(s)
- Cali A. Calarco
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | | | - Seth R. Taylor
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | - Somin Lee
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | - Wenliang Zhou
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | | | - Yann S. Mineur
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | | | - Marina R. Picciotto
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
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50
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Jeong JH, Lee DK, Liu SM, Chua SC, Schwartz GJ, Jo YH. Activation of temperature-sensitive TRPV1-like receptors in ARC POMC neurons reduces food intake. PLoS Biol 2018; 16:e2004399. [PMID: 29689050 PMCID: PMC5915833 DOI: 10.1371/journal.pbio.2004399] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 03/20/2018] [Indexed: 01/05/2023] Open
Abstract
Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) respond to numerous hormonal and neural signals, resulting in changes in food intake. Here, we demonstrate that ARC POMC neurons express capsaicin-sensitive transient receptor potential vanilloid 1 receptor (TRPV1)-like receptors. To show expression of TRPV1-like receptors in ARC POMC neurons, we use single-cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiology, TRPV1 knock-out (KO), and TRPV1-Cre knock-in mice. A small elevation of temperature in the physiological range is enough to depolarize ARC POMC neurons. This depolarization is blocked by the TRPV1 receptor antagonist and by Trpv1 gene knockdown. Capsaicin-induced activation reduces food intake that is abolished by a melanocortin receptor antagonist. To selectively stimulate TRPV1-like receptor-expressing ARC POMC neurons in the ARC, we generate an adeno-associated virus serotype 5 (AAV5) carrying a Cre-dependent channelrhodopsin-2 (ChR2)–enhanced yellow fluorescent protein (eYFP) expression cassette under the control of the two neuronal POMC enhancers (nPEs). Optogenetic stimulation of TRPV1-like receptor-expressing POMC neurons decreases food intake. Hypothalamic temperature is rapidly elevated and reaches to approximately 39 °C during treadmill running. This elevation is associated with a reduction in food intake. Knockdown of the Trpv1 gene exclusively in ARC POMC neurons blocks the feeding inhibition produced by increased hypothalamic temperature. Taken together, our findings identify a melanocortinergic circuit that links acute elevations in hypothalamic temperature with acute reductions in food intake. Intense exercise acutely decreases appetite and subsequent food intake. As exercise is accompanied by increased body temperature, we hypothesized that a rise in body temperature during exercise plays a role in reducing food intake. The hypothalamic neurons are major components of the neural circuits that control feeding in response to hormones and neural signals. Among hypothalamic neurons, those that express proopiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus are important in controlling food intake. In this study, we found that these POMC-expressing neurons express TRPV1-like thermoreceptors that are activated by an increase in temperature within the physiological range in mice. We also showed that an increase in body temperature during exercise is directly sensed by these POMC-expressing neurons through activation of the TRPV1-like receptors. Hence, this study provides a novel perspective on the cellular mechanisms underlying energy balance: body temperature reduces food intake via TRPV1-like receptors in POMC-expressing neurons in the arcuate nucleus of the hypothalamus.
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Affiliation(s)
- Jae Hoon Jeong
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, United States of America
| | - Dong Kun Lee
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, United States of America
- Department of Physiology, College of Medicine, Gyeongsang National University, Jinju, Korea
| | - Shun-Mei Liu
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, United States of America
| | - Streamson C. Chua
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, United States of America
| | - Gary J. Schwartz
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, United States of America
| | - Young-Hwan Jo
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, United States of America
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, United States of America
- * E-mail:
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