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He Q, Yuan Q, Shan H, Wu C, Gu Y, Wu K, Hu W, Zhang Y, He X, Xu HE, Zhao LH. Mechanisms of ligand recognition and activation of melanin-concentrating hormone receptors. Cell Discov 2024; 10:48. [PMID: 38710677 DOI: 10.1038/s41421-024-00679-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/10/2024] [Indexed: 05/08/2024] Open
Abstract
Melanin-concentrating hormone (MCH) is a cyclic neuropeptide that regulates food intake, energy balance, and other physiological functions by stimulating MCHR1 and MCHR2 receptors, both of which are class A G protein-coupled receptors. MCHR1 predominately couples to inhibitory G protein, Gi/o, and MCHR2 can only couple to Gq/11. Here we present cryo-electron microscopy structures of MCH-activated MCHR1 with Gi and MCH-activated MCHR2 with Gq at the global resolutions of 3.01 Å and 2.40 Å, respectively. These structures reveal that MCH adopts a consistent cysteine-mediated hairpin loop configuration when bound to both receptors. A central arginine from the LGRVY core motif between the two cysteines of MCH penetrates deeply into the transmembrane pocket, triggering receptor activation. Integrated with mutational and functional insights, our findings elucidate the molecular underpinnings of ligand recognition and MCH receptor activation and offer a structural foundation for targeted drug design.
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Affiliation(s)
- Qian He
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qingning Yuan
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Hong Shan
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Canrong Wu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yimin Gu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Kai Wu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wen Hu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yumu Zhang
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xinheng He
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - H Eric Xu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Li-Hua Zhao
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
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2
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Engström Ruud L, Font-Gironès F, Zajdel J, Kern L, Teixidor-Deulofeu J, Mannerås-Holm L, Carreras A, Becattini B, Björefeldt A, Hanse E, Fenselau H, Solinas G, Brüning JC, Wunderlich TF, Bäckhed F, Ruud J. Activation of GFRAL + neurons induces hypothermia and glucoregulatory responses associated with nausea and torpor. Cell Rep 2024; 43:113960. [PMID: 38507407 DOI: 10.1016/j.celrep.2024.113960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/11/2024] [Accepted: 02/28/2024] [Indexed: 03/22/2024] Open
Abstract
GFRAL-expressing neurons actuate aversion and nausea, are targets for obesity treatment, and may mediate metformin effects by long-term GDF15-GFRAL agonism. Whether GFRAL+ neurons acutely regulate glucose and energy homeostasis is, however, underexplored. Here, we report that cell-specific activation of GFRAL+ neurons using a variety of techniques causes a torpor-like state, including hypothermia, the release of stress hormones, a shift from glucose to lipid oxidation, and impaired insulin sensitivity, glucose tolerance, and skeletal muscle glucose uptake but augmented glucose uptake in visceral fat. Metabolomic analysis of blood and transcriptomics of muscle and fat indicate alterations in ketogenesis, insulin signaling, adipose tissue differentiation and mitogenesis, and energy fluxes. Our findings indicate that acute GFRAL+ neuron activation induces endocrine and gluco- and thermoregulatory responses associated with nausea and torpor. While chronic activation of GFRAL signaling promotes weight loss in obesity, these results show that acute activation of GFRAL+ neurons causes hypothermia and hyperglycemia.
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Affiliation(s)
- Linda Engström Ruud
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ferran Font-Gironès
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Joanna Zajdel
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lara Kern
- Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Júlia Teixidor-Deulofeu
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Louise Mannerås-Holm
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Alba Carreras
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Barbara Becattini
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Andreas Björefeldt
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Eric Hanse
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Giovanni Solinas
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Jens C Brüning
- Max Planck Institute for Metabolism Research, Cologne, Germany
| | | | - Fredrik Bäckhed
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Johan Ruud
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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3
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Kuebler IRK, Suárez M, Wakabayashi KT. Sex differences and sex-specific regulation of motivated behavior by Melanin-concentrating hormone: a short review. Biol Sex Differ 2024; 15:33. [PMID: 38570844 PMCID: PMC10993549 DOI: 10.1186/s13293-024-00608-0] [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: 11/11/2023] [Accepted: 03/23/2024] [Indexed: 04/05/2024] Open
Abstract
Recent preclinical research exploring how neuropeptide transmitter systems regulate motivated behavior reveal the increasing importance of sex as a critical biological variable. Neuropeptide systems and their central circuits both contribute to sex differences in a range of motivated behaviors and regulate sex-specific behaviors. In this short review, we explore the current research of how sex as a biological variable influences several distinct motivated behaviors that are modulated by the melanin-concentrating hormone (MCH) neuropeptide system. First, we review how MCH regulates feeding behavior within the context of energy homeostasis differently between male and female rodents. Then, we focus on MCH's role in lactation as a sex-specific process within the context of energy homeostasis. Next, we discuss the sex-specific effects of MCH on maternal behavior. Finally, we summarize the role of MCH in drug-motivated behaviors. While these topics are traditionally investigated from different scientific perspectives, in this short review we discuss how these behaviors share commonalities within the larger context of motivated behaviors, and that sex differences discovered in one area of research may impact our understanding in another. Overall, our review highlights the need for further research into how sex differences in energy regulation associated with reproduction and parental care contribute to regulating motivated behaviors.
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Affiliation(s)
- Isabel R K Kuebler
- Neurocircuitry of Motivated Behavior Laboratory, Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, 68588-0308, USA
| | - Mauricio Suárez
- Neurocircuitry of Motivated Behavior Laboratory, Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, 68588-0308, USA
| | - Ken T Wakabayashi
- Neurocircuitry of Motivated Behavior Laboratory, Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, 68588-0308, USA.
- Rural Drug Addiction Research Center, University of Nebraska-Lincoln, 660 N 12th St., Lincoln, NE, 68588, USA.
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4
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Miller PA, Williams-Ikhenoba JG, Sankhe AS, Hoffe BH, Chee MJ. Neuroanatomical, electrophysiological, and morphological characterization of melanin-concentrating hormone cells coexpressing cocaine- and amphetamine-regulated transcript. J Comp Neurol 2024; 532:e25588. [PMID: 38335050 DOI: 10.1002/cne.25588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 12/18/2023] [Accepted: 01/09/2024] [Indexed: 02/12/2024]
Abstract
Melanin-concentrating hormone (MCH) cells in the hypothalamus regulate fundamental physiological functions like energy balance, sleep, and reproduction. This diversity may be ascribed to the neurochemical heterogeneity among MCH cells. One prominent subpopulation of MCH cells coexpresses cocaine- and amphetamine-regulated transcript (CART), and as MCH and CART can have opposing actions, MCH/CART+ and MCH/CART- cells may differentially modulate behavioral outcomes. However, it is not known if there are differences in the cellular properties underlying their functional differences; thus, we compared the neuroanatomical, electrophysiological, and morphological properties of MCH cells in male and female Mch-cre;L10-Egfp reporter mice. Half of MCH cells expressed CART and were most prominent in the medial hypothalamus. Whole-cell patch-clamp recordings revealed differences in their passive and active membrane properties in a sex-dependent manner. Female MCH/CART+ cells had lower input resistances, but male cells largely differed in their firing properties. All MCH cells increased firing when stimulated, but their firing frequency decreases with sustained stimulation. MCH/CART+ cells showed stronger spike rate adaptation than MCH/CART- cells. The kinetics of excitatory events at MCH cells also differed by cell type, as the rising rate of excitatory events was slower at MCH/CART+ cells. By reconstructing the dendritic arborization of our recorded cells, we found no sex differences, but male MCH/CART+ cells had less dendritic length and fewer branch points. Overall, distinctions in topographical division and cellular properties between MCH cells add to their heterogeneity and help elucidate their response to stimuli or effect on modulating their respective neural networks.
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Affiliation(s)
| | | | - Aditi S Sankhe
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Brendan H Hoffe
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Melissa J Chee
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
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5
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Concetti C, Peleg-Raibstein D, Burdakov D. Hypothalamic MCH Neurons: From Feeding to Cognitive Control. FUNCTION 2023; 5:zqad059. [PMID: 38020069 PMCID: PMC10667013 DOI: 10.1093/function/zqad059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
Modern neuroscience is progressively elucidating that the classic view positing distinct brain regions responsible for survival, emotion, and cognitive functions is outdated. The hypothalamus demonstrates the interdependence of these roles, as it is traditionally known for fundamental survival functions like energy and electrolyte balance, but is now recognized to also play a crucial role in emotional and cognitive processes. This review focuses on lateral hypothalamic melanin-concentrating hormone (MCH) neurons, producing the neuropeptide MCH-a relatively understudied neuronal population with integrative functions related to homeostatic regulation and motivated behaviors, with widespread inputs and outputs throughout the entire central nervous system. Here, we review early findings and recent literature outlining their role in the regulation of energy balance, sleep, learning, and memory processes.
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Affiliation(s)
- Cristina Concetti
- Neurobehavioural Dynamics Laboratory, ETH Zürich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland
| | - Daria Peleg-Raibstein
- Neurobehavioural Dynamics Laboratory, ETH Zürich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland
| | - Denis Burdakov
- Neurobehavioural Dynamics Laboratory, ETH Zürich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland
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6
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Masliukov PM. Changes of Signaling Pathways in Hypothalamic Neurons with Aging. Curr Issues Mol Biol 2023; 45:8289-8308. [PMID: 37886966 PMCID: PMC10605528 DOI: 10.3390/cimb45100523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/01/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023] Open
Abstract
The hypothalamus is an important regulator of autonomic and endocrine functions also involved in aging regulation. The aging process in the hypothalamus is accompanied by disturbed intracellular signaling including insulin/insulin-like growth factor-1 (IGF-1)/growth hormone (GH), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/the mammalian target of rapamycin (mTOR), mitogen activated protein kinase (MAPK), janus kinase (JAK)/signal transducer and activator of transcription (STAT), AMP-activated protein kinase (AMPK), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), and nitric oxide (NO). In the current review, I have summarized the current understanding of the changes in the above-mentioned pathways in aging with a focus on hypothalamic alterations.
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Affiliation(s)
- Petr M Masliukov
- Department Normal Physiology, Yaroslavl State Medical University, ul. Revoliucionnaya 5, 150000 Yaroslavl, Russia
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7
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Rossi MA. Control of energy homeostasis by the lateral hypothalamic area. Trends Neurosci 2023; 46:738-749. [PMID: 37353461 PMCID: PMC10524917 DOI: 10.1016/j.tins.2023.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 06/25/2023]
Abstract
The lateral hypothalamic area (LHA) is a subcortical brain region that exerts control over motivated behavior, feeding, and energy balance across species. Recent single-cell sequencing studies have defined at least 30 distinct LHA neuron types. Some of these influence specific aspects of energy homeostasis; however, the functions of many LHA cell types remain unclear. This review addresses the rapidly emerging evidence from cell-type-specific investigations that the LHA leverages distinct neuron populations to regulate energy balance through complex connections with other brain regions. It will highlight recent findings demonstrating that LHA control of energy balance extends beyond mere food intake and propose outstanding questions to be addressed by future research.
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Affiliation(s)
- Mark A Rossi
- Child Health Institute of New Jersey, New Brunswick, NJ, USA; Department of Psychiatry, Robert Wood Johnson Medical School, New Brunswick, NJ, USA; Brain Health Institute, Rutgers University, New Brunswick, NJ, USA.
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8
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Bouâouda H, Jha PK. Orexin and MCH neurons: regulators of sleep and metabolism. Front Neurosci 2023; 17:1230428. [PMID: 37674517 PMCID: PMC10478345 DOI: 10.3389/fnins.2023.1230428] [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: 05/28/2023] [Accepted: 08/07/2023] [Indexed: 09/08/2023] Open
Abstract
Sleep-wake and fasting-feeding are tightly coupled behavioral states that require coordination between several brain regions. The mammalian lateral hypothalamus (LH) is a functionally and anatomically complex brain region harboring heterogeneous cell populations that regulate sleep, feeding, and energy metabolism. Significant attempts were made to understand the cellular and circuit bases of LH actions. Rapid advancements in genetic and electrophysiological manipulation help to understand the role of discrete LH cell populations. The opposing action of LH orexin/hypocretin and melanin-concentrating hormone (MCH) neurons on metabolic sensing and sleep-wake regulation make them the candidate to explore in detail. This review surveys the molecular, genetic, and neuronal components of orexin and MCH signaling in the regulation of sleep and metabolism.
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Affiliation(s)
- Hanan Bouâouda
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Pawan Kumar Jha
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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9
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Rhea EM, Leclerc M, Yassine HN, Capuano AW, Tong H, Petyuk VA, Macauley SL, Fioramonti X, Carmichael O, Calon F, Arvanitakis Z. State of the Science on Brain Insulin Resistance and Cognitive Decline Due to Alzheimer's Disease. Aging Dis 2023:AD.2023.0814. [PMID: 37611907 DOI: 10.14336/ad.2023.0814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/14/2023] [Indexed: 08/25/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is common and increasing in prevalence worldwide, with devastating public health consequences. While peripheral insulin resistance is a key feature of most forms of T2DM and has been investigated for over a century, research on brain insulin resistance (BIR) has more recently been developed, including in the context of T2DM and non-diabetes states. Recent data support the presence of BIR in the aging brain, even in non-diabetes states, and found that BIR may be a feature in Alzheimer's disease (AD) and contributes to cognitive impairment. Further, therapies used to treat T2DM are now being investigated in the context of AD treatment and prevention, including insulin. In this review, we offer a definition of BIR, and present evidence for BIR in AD; we discuss the expression, function, and activation of the insulin receptor (INSR) in the brain; how BIR could develop; tools to study BIR; how BIR correlates with current AD hallmarks; and regional/cellular involvement of BIR. We close with a discussion on resilience to both BIR and AD, how current tools can be improved to better understand BIR, and future avenues for research. Overall, this review and position paper highlights BIR as a plausible therapeutic target for the prevention of cognitive decline and dementia due to AD.
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Affiliation(s)
- Elizabeth M Rhea
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA 98195, USA
| | - Manon Leclerc
- Faculty of Pharmacy, Laval University, Quebec, Quebec, Canada
- Neuroscience Axis, CHU de Québec Research Center - Laval University, Quebec, Quebec, Canada
| | - Hussein N Yassine
- Departments of Neurology and Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Ana W Capuano
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
| | - Han Tong
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
| | - Vladislav A Petyuk
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Shannon L Macauley
- Department of Physiology, University of Kentucky, Lexington, KY 40508, USA
| | - Xavier Fioramonti
- Univ. Bordeaux, INRAE, Bordeaux INP, NutriNeuro, UMR 1286, F-33000 Bordeaux, France
- International Associated Laboratory OptiNutriBrain, Bordeaux, France and Quebec, Canada
| | - Owen Carmichael
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Frederic Calon
- Faculty of Pharmacy, Laval University, Quebec, Quebec, Canada
- Neuroscience Axis, CHU de Québec Research Center - Laval University, Quebec, Quebec, Canada
- International Associated Laboratory OptiNutriBrain, Bordeaux, France and Quebec, Canada
| | - Zoe Arvanitakis
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
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10
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Fang LZ, Linehan V, Licursi M, Alberto CO, Power JL, Parsons MP, Hirasawa M. Prostaglandin E 2 activates melanin-concentrating hormone neurons to drive diet-induced obesity. Proc Natl Acad Sci U S A 2023; 120:e2302809120. [PMID: 37467285 PMCID: PMC10401019 DOI: 10.1073/pnas.2302809120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/09/2023] [Indexed: 07/21/2023] Open
Abstract
Hypothalamic inflammation reduces appetite and body weight during inflammatory diseases, while promoting weight gain when induced by high-fat diet (HFD). How hypothalamic inflammation can induce opposite energy balance outcomes remains unclear. We found that prostaglandin E2 (PGE2), a key hypothalamic inflammatory mediator of sickness, also mediates diet-induced obesity (DIO) by activating appetite-promoting melanin-concentrating hormone (MCH) neurons in the hypothalamus in rats and mice. The effect of PGE2 on MCH neurons is excitatory at low concentrations while inhibitory at high concentrations, indicating that these neurons can bidirectionally respond to varying levels of inflammation. During prolonged HFD, endogenous PGE2 depolarizes MCH neurons through an EP2 receptor-mediated inhibition of the electrogenic Na+/K+-ATPase. Disrupting this mechanism by genetic deletion of EP2 receptors on MCH neurons is protective against DIO and liver steatosis in male and female mice. Thus, an inflammatory mediator can directly stimulate appetite-promoting neurons to exacerbate DIO and fatty liver.
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Affiliation(s)
- Lisa Z. Fang
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Victoria Linehan
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Maria Licursi
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Christian O. Alberto
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Jacob L. Power
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Matthew P. Parsons
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Michiru Hirasawa
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
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11
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Baghdadi M, Nespital T, Mesaros A, Buschbaum S, Withers DJ, Grönke S, Partridge L. Reduced insulin signaling in neurons induces sex-specific health benefits. SCIENCE ADVANCES 2023; 9:eade8137. [PMID: 36812323 PMCID: PMC9946356 DOI: 10.1126/sciadv.ade8137] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Reduced activity of insulin/insulin-like growth factor signaling (IIS) extends health and life span in mammals. Loss of the insulin receptor substrate 1 (Irs1) gene increases survival in mice and causes tissue-specific changes in gene expression. However, the tissues underlying IIS-mediated longevity are currently unknown. Here, we measured survival and health span in mice lacking IRS1 specifically in liver, muscle, fat, and brain. Tissue-specific loss of IRS1 did not increase survival, suggesting that lack of IRS1 in more than one tissue is required for life-span extension. Loss of IRS1 in liver, muscle, and fat did not improve health. In contrast, loss of neuronal IRS1 increased energy expenditure, locomotion, and insulin sensitivity, specifically in old males. Neuronal loss of IRS1 also caused male-specific mitochondrial dysfunction, activation of Atf4, and metabolic adaptations consistent with an activated integrated stress response at old age. Thus, we identified a male-specific brain signature of aging in response to reduced IIS associated with improved health at old age.
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Affiliation(s)
| | - Tobias Nespital
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Andrea Mesaros
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Dominic J. Withers
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- Medical Research Council London Institute of Medical Sciences, London, UK
| | | | - Linda Partridge
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
- Institute of Healthy Ageing and Genetics, Evolution and Environment, University College London, London, UK
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12
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Potter LE, Burgess CR. The melanin-concentrating hormone system as a target for the treatment of sleep disorders. Front Neurosci 2022; 16:952275. [PMID: 36177357 PMCID: PMC9513178 DOI: 10.3389/fnins.2022.952275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Given the widespread prevalence of sleep disorders and their impacts on health, it is critical that researchers continue to identify and evaluate novel avenues of treatment. Recently the melanin-concentrating hormone (MCH) system has attracted commercial and scientific interest as a potential target of pharmacotherapy for sleep disorders. This interest emerges from basic scientific research demonstrating a role for MCH in regulating sleep, and particularly REM sleep. In addition to this role in sleep regulation, the MCH system and the MCH receptor 1 (MCHR1) have been implicated in a wide variety of other physiological functions and behaviors, including feeding/metabolism, reward, anxiety, depression, and learning. The basic research literature on sleep and the MCH system, and the history of MCH drug development, provide cause for both skepticism and cautious optimism about the prospects of MCH-targeting drugs in sleep disorders. Extensive efforts have focused on developing MCHR1 antagonists for use in obesity, however, few of these drugs have advanced to clinical trials, and none have gained regulatory approval. Additional basic research will be needed to fully characterize the MCH system’s role in sleep regulation, for example, to fully differentiate between MCH-neuron and peptide/receptor-mediated functions. Additionally, a number of issues relating to drug design will continue to pose a practical challenge for novel pharmacotherapies targeting the MCH system.
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Affiliation(s)
- Liam E. Potter
- Department of Molecular and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Liam E. Potter,
| | - Christian R. Burgess
- Department of Molecular and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
- Christian R. Burgess,
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13
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He X, Li Y, Zhang N, Huang J, Ming X, Guo R, Hu Y, Ji P, Guo F. Melanin-concentrating hormone promotes anxiety and intestinal dysfunction via basolateral amygdala in mice. Front Pharmacol 2022; 13:906057. [PMID: 36016574 PMCID: PMC9395614 DOI: 10.3389/fphar.2022.906057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/08/2022] [Indexed: 11/13/2022] Open
Abstract
The limbic system plays a pivotal role in stress-induced anxiety and intestinal disorders, but how the functional circuits between nuclei within the limbic system are engaged in the processing is still unclear. In our study, the results of fluorescence gold retrograde tracing and fluorescence immunohistochemistry showed that the melanin-concentrating hormone (MCH) neurons of the lateral hypothalamic area (LHA) projected to the basolateral amygdala (BLA). Both chemogenetic activation of MCH neurons and microinjection of MCH into the BLA induced anxiety disorder in mice, which were reversed by intra-BLA microinjection of MCH receptor 1 (MCHR1) blocker SNAP-94847. In the chronic acute combining stress (CACS) stimulated mice, SNAP94847 administrated in the BLA ameliorated anxiety-like behaviors and improved intestinal dysfunction via reducing intestinal permeability and inflammation. In conclusion, MCHergic circuit from the LHA to the BLA participates in the regulation of anxiety-like behavior in mice, and this neural pathway is related to the intestinal dysfunction in CACS mice by regulating intestinal permeability and inflammation.
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Affiliation(s)
- Xiaoman He
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yuhang Li
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Nana Zhang
- Department of Clinical Laboratory, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jinfang Huang
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xing Ming
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Ruixiao Guo
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yang Hu
- Qingdao Medical College, Qingdao University, Qingdao, China
| | - Pengfei Ji
- Qingdao Medical College, Qingdao University, Qingdao, China
| | - Feifei Guo
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
- *Correspondence: Feifei Guo,
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14
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The central nervous system control of energy homeostasis: high fat diet induced hypothalamic microinflammation and obesity. Brain Res Bull 2022; 185:99-106. [PMID: 35525336 DOI: 10.1016/j.brainresbull.2022.04.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/27/2022] [Accepted: 04/30/2022] [Indexed: 11/22/2022]
Abstract
Obesity is believed to arise through the imbalance of energy homeostasis controlled by the central nervous system, where the hypothalamus plays the fundamental role in energy metabolism. In this review, we will provide an overview regarding the functions of POMC neurons and AgRP neurons in acute nucleus of the hypothalamus which mediated the energy metabolism, highlighting their interactions with peripheral organs derived hormones in control of energy homeostasis. Furthermore, the role of high fat diet induced hypothalamic microinflammation in the pathogenesis of obesity will be discussed. We hope this review could help researchers to understand the mechanism of hypothalamus in control of energy metabolism, and design related drugs to block the pathways involving in the impaired metabolism in obese patients.
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15
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Chen W, Cai W, Hoover B, Kahn CR. Insulin action in the brain: cell types, circuits, and diseases. Trends Neurosci 2022; 45:384-400. [PMID: 35361499 PMCID: PMC9035105 DOI: 10.1016/j.tins.2022.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/10/2022] [Accepted: 03/03/2022] [Indexed: 10/18/2022]
Abstract
Since its discovery over 100 years ago, insulin has been recognized as a key hormone in control of glucose homeostasis. Deficiencies of insulin signaling are central to diabetes and many other disorders. The brain is among the targets of insulin action, and insulin resistance is a major contributor to many diseases, including brain disorders. Here, we summarize key roles of insulin action in the brain and how this involves different brain cell types. Disordered brain insulin signaling can also contribute to neuropsychiatric diseases, affecting brain circuits involved in mood and cognition. Understanding of insulin signaling in different brain cell types/circuits and how these are altered in disease may lead to the development of new therapeutic approaches to these challenging disorders.
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16
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Crosstalk between Melanin Concentrating Hormone and Endocrine Factors: Implications for Obesity. Int J Mol Sci 2022; 23:ijms23052436. [PMID: 35269579 PMCID: PMC8910548 DOI: 10.3390/ijms23052436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/10/2022] [Accepted: 02/21/2022] [Indexed: 01/03/2023] Open
Abstract
Melanin-concentrating hormone (MCH) is a 19aa cyclic peptide exclusively expressed in the lateral hypothalamic area, which is an area of the brain involved in a large number of physiological functions and vital processes such as nutrient sensing, food intake, sleep-wake arousal, memory formation, and reproduction. However, the role of the lateral hypothalamic area in metabolic regulation stands out as the most relevant function. MCH regulates energy balance and glucose homeostasis by controlling food intake and peripheral lipid metabolism, energy expenditure, locomotor activity and brown adipose tissue thermogenesis. However, the MCH control of energy balance is a complex mechanism that involves the interaction of several neuroendocrine systems. The aim of the present work is to describe the current knowledge of the crosstalk of MCH with different endocrine factors. We also provide our view about the possible use of melanin-concentrating hormone receptor antagonists for the treatment of metabolic complications. In light of the data provided here and based on its actions and function, we believe that the MCH system emerges as an important target for the treatment of obesity and its comorbidities.
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17
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Choi JH, Kim MS. Homeostatic Regulation of Glucose Metabolism by the Central Nervous System. Endocrinol Metab (Seoul) 2022; 37:9-25. [PMID: 35255598 PMCID: PMC8901968 DOI: 10.3803/enm.2021.1364] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/07/2022] [Indexed: 12/04/2022] Open
Abstract
Evidence for involvement of the central nervous system (CNS) in the regulation of glucose metabolism dates back to the 19th century, although the majority of the research on glucose metabolism has focused on the peripheral metabolic organs. Due to recent advances in neuroscience, it has now become clear that the CNS is indeed vital for maintaining glucose homeostasis. To achieve normoglycemia, specific populations of neurons and glia in the hypothalamus sense changes in the blood concentrations of glucose and of glucoregulatory hormones such as insulin, leptin, glucagon-like peptide 1, and glucagon. This information is integrated and transmitted to other areas of the brain where it eventually modulates various processes in glucose metabolism (i.e., hepatic glucose production, glucose uptake in the brown adipose tissue and skeletal muscle, pancreatic insulin and glucagon secretion, renal glucose reabsorption, etc.). Errors in these processes lead to hyper- or hypoglycemia. We here review the current understanding of the brain regulation of glucose metabolism.
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Affiliation(s)
- Jong Han Choi
- Division of Endocrinology and Metabolism, Konkuk University Medical Center, Seoul,
Korea
| | - Min-Seon Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul,
Korea
- Appeptite Regulation Laboratory, Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul,
Korea
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18
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PI3K and AKT at the Interface of Signaling and Metabolism. Curr Top Microbiol Immunol 2022; 436:311-336. [DOI: 10.1007/978-3-031-06566-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Porniece Kumar M, Cremer AL, Klemm P, Steuernagel L, Sundaram S, Jais A, Hausen AC, Tao J, Secher A, Pedersen TÅ, Schwaninger M, Wunderlich FT, Lowell BB, Backes H, Brüning JC. Insulin signalling in tanycytes gates hypothalamic insulin uptake and regulation of AgRP neuron activity. Nat Metab 2021; 3:1662-1679. [PMID: 34931084 PMCID: PMC8688146 DOI: 10.1038/s42255-021-00499-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 10/26/2021] [Indexed: 12/02/2022]
Abstract
Insulin acts on neurons and glial cells to regulate systemic glucose metabolism and feeding. However, the mechanisms of insulin access in discrete brain regions are incompletely defined. Here we show that insulin receptors in tanycytes, but not in brain endothelial cells, are required to regulate insulin access to the hypothalamic arcuate nucleus. Mice lacking insulin receptors in tanycytes (IR∆Tan mice) exhibit systemic insulin resistance, while displaying normal food intake and energy expenditure. Tanycytic insulin receptors are also necessary for the orexigenic effects of ghrelin, but not for the anorexic effects of leptin. IR∆Tan mice exhibit increased agouti-related peptide (AgRP) neuronal activity, while displaying blunted AgRP neuronal adaptations to feeding-related stimuli. Lastly, a highly palatable food decreases tanycytic and arcuate nucleus insulin signalling to levels comparable to those seen in IR∆Tan mice. These changes are rooted in modifications of cellular stress responses and of mitochondrial protein quality control in tanycytes. Conclusively, we reveal a critical role of tanycyte insulin receptors in gating feeding-state-dependent regulation of AgRP neurons and systemic insulin sensitivity, and show that insulin resistance in tanycytes contributes to the pleiotropic manifestations of obesity-associated insulin resistance.
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Affiliation(s)
- Marta Porniece Kumar
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Anna Lena Cremer
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Paul Klemm
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Lukas Steuernagel
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Sivaraj Sundaram
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Alexander Jais
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, 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
| | - A Christine Hausen
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Jenkang Tao
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - Anna Secher
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | | | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - F Thomas Wunderlich
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Bradford B Lowell
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - Heiko Backes
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Jens C Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany.
- Policlinic for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany.
- National Center for Diabetes Research (DZD), Neuherberg, Germany.
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20
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Al-Massadi O, Dieguez C, Schneeberger M, López M, Schwaninger M, Prevot V, Nogueiras R. Multifaceted actions of melanin-concentrating hormone on mammalian energy homeostasis. Nat Rev Endocrinol 2021; 17:745-755. [PMID: 34608277 DOI: 10.1038/s41574-021-00559-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 12/12/2022]
Abstract
Melanin-concentrating hormone (MCH) is a small cyclic peptide expressed in all mammals, mainly in the hypothalamus. MCH acts as a robust integrator of several physiological functions and has crucial roles in the regulation of sleep-wake rhythms, feeding behaviour and metabolism. MCH signalling has a very broad endocrine context and is involved in physiological functions and emotional states associated with metabolism, such as reproduction, anxiety, depression, sleep and circadian rhythms. MCH mediates its functions through two receptors (MCHR1 and MCHR2), of which only MCHR1 is common to all mammals. Owing to the wide variety of MCH downstream signalling pathways, MCHR1 agonists and antagonists have great potential as tools for the directed management of energy balance disorders and associated metabolic complications, and translational strategies using these compounds hold promise for the development of novel treatments for obesity. This Review provides an overview of the numerous roles of MCH in energy and glucose homeostasis, as well as in regulation of the mesolimbic dopaminergic circuits that encode the hedonic component of food intake.
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Affiliation(s)
- Omar Al-Massadi
- Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Spain.
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain.
| | - Carlos Dieguez
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Marc Schneeberger
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Miguel López
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Vincent Prevot
- Univ. Lille, Inserm, CHU Lille, Lille Neuroscience and Cognition, Laboratory of Development and Plasticity of the Neuroendocrine Brain, UMR-S1172, EGID, Lille, France
| | - Ruben Nogueiras
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain.
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain.
- Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, Spain.
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21
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Ozawa A, Arakawa H. Chemogenetics drives paradigm change in the investigation of behavioral circuits and neural mechanisms underlying drug action. Behav Brain Res 2021; 406:113234. [PMID: 33741409 PMCID: PMC8110310 DOI: 10.1016/j.bbr.2021.113234] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/06/2021] [Accepted: 03/08/2021] [Indexed: 12/12/2022]
Abstract
Recent developments in chemogenetic approaches to the investigation of brain function have ushered in a paradigm change in the strategy for drug and behavior research and clinical drug-based medications. As the nature of the drug action is based on humoral regulation, it is a challenge to identify the neuronal mechanisms responsible for the expression of certain targeted behavior induced by drug application. The development of chemogenetic approaches has allowed researchers to control neural activities in targeted neurons through a toolbox, including engineered G protein-coupled receptors or ligand-gated ion channels together with exogenously inert synthetic ligands. This review provides a brief overview of the chemogenetics toolbox with an emphasis on the DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) technique used in rodent models, which is applicable to the investigation of how specific neural circuits regulate behavioral processes. The use of chemogenetics has had a significant impact on basic neuroscience for a better understanding of the relationships between brain activity and the expression of behaviors with cell- and circuit-specific orders. Furthermore, chemogenetics is potentially a useful tool to deconstruct the neuropathological mechanisms of mental diseases and its regulation by drug, and provide us with transformative therapeutics with medication. We also review recent findings in the use of chemogenetic techniques to uncover functional circuit connections of serotonergic neurons in rodent models.
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Affiliation(s)
- Akihiko Ozawa
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, USA
| | - Hiroyuki Arakawa
- Department of Psychology, Tokiwa University, Mito, Ibaraki, Japan; Department of Systems Physiology, University of Ryukyus, Faculty of Medicine, Nakagami District, Okinawa, Japan.
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22
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Beddows CA, Dodd GT. Insulin on the brain: The role of central insulin signalling in energy and glucose homeostasis. J Neuroendocrinol 2021; 33:e12947. [PMID: 33687120 DOI: 10.1111/jne.12947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/26/2022]
Abstract
Insulin signals to the brain where it coordinates multiple physiological processes underlying energy and glucose homeostasis. This review explores where and how insulin interacts within the brain parenchyma, how brain insulin signalling functions to coordinate energy and glucose homeostasis and how this contributes to the pathogenesis of metabolic disease.
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Affiliation(s)
- Cait A Beddows
- Department of Anatomy and Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Garron T Dodd
- Department of Anatomy and Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
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23
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Ladyman SR, Brooks VL. Central actions of insulin during pregnancy and lactation. J Neuroendocrinol 2021; 33:e12946. [PMID: 33710714 PMCID: PMC9198112 DOI: 10.1111/jne.12946] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/24/2021] [Accepted: 01/27/2021] [Indexed: 12/17/2022]
Abstract
Pregnancy and lactation are highly metabolically demanding states. Maternal glucose is a key fuel source for the growth and development of the fetus, as well as for the production of milk during lactation. Hence, the maternal body undergoes major adaptations in the systems regulating glucose homeostasis to cope with the increased demand for glucose. As part of these changes, insulin levels are elevated during pregnancy and lower in lactation. The increased insulin secretion during pregnancy plays a vital role in the periphery; however, the potential effects of increased insulin action in the brain have not been widely investigated. In this review, we consider the impact of pregnancy on brain access and brain levels of insulin. Moreover, we explore the hypothesis that pregnancy is associated with site-specific central insulin resistance that is adaptive, allowing for the increases in peripheral insulin secretion without the consequences of increased central and peripheral insulin functions, such as to stimulate glucose uptake into maternal tissues or to inhibit food intake. Conversely, the loss of central insulin actions may impair other functions, such as insulin control of the autonomic nervous system. The potential role of low insulin in facilitating adaptive responses to lactation, such as hyperphagia and suppression of reproductive function, are also discussed. We end the review with a list of key research questions requiring resolution.
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Affiliation(s)
- Sharon R Ladyman
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Virginia L Brooks
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, USA
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24
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Garcia SM, Hirschberg PR, Sarkar P, Siegel DM, Teegala SB, Vail GM, Routh VH. Insulin actions on hypothalamic glucose-sensing neurones. J Neuroendocrinol 2021; 33:e12937. [PMID: 33507001 PMCID: PMC10561189 DOI: 10.1111/jne.12937] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/13/2022]
Abstract
Subsequent to the discovery of insulin 100 years ago, great strides have been made in understanding its function, especially in the brain. It is now clear that insulin is a critical regulator of the neuronal circuitry controlling energy balance and glucose homeostasis. This review focuses on the effects of insulin and diabetes on the activity and glucose sensitivity of hypothalamic glucose-sensing neurones. We highlight the role of electrophysiological data in understanding how insulin regulates glucose-sensing neurones. A brief introduction describing the benefits and limitations of the major electrophysiological techniques used to investigate glucose-sensing neurones is provided. The mechanisms by which hypothalamic neurones sense glucose are discussed with an emphasis on those glucose-sensing neurones already shown to be modulated by insulin. Next, the literature pertaining to how insulin alters the activity and glucose sensitivity of these hypothalamic glucose-sensing neurones is described. In addition, the effects of impaired insulin signalling during diabetes and the ramifications of insulin-induced hypoglycaemia on hypothalamic glucose-sensing neurones are covered. To the extent that it is known, we present hypotheses concerning the mechanisms underlying the effects of these insulin-related pathologies. To conclude, electrophysiological data from the hippocampus are evaluated aiming to provide clues regarding how insulin might influence neuronal plasticity in glucose-sensing neurones. Although much has been accomplished subsequent to the discovery of insulin, the work described in our review suggests that the regulation of central glucose sensing by this hormone is both important and understudied.
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Affiliation(s)
- Stephanie M Garcia
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Pamela R Hirschberg
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Pallabi Sarkar
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Dashiel M Siegel
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Suraj B Teegala
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Gwyndolin M Vail
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Vanessa H Routh
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
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25
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Lord MN, Subramanian K, Kanoski SE, Noble EE. Melanin-concentrating hormone and food intake control: Sites of action, peptide interactions, and appetition. Peptides 2021; 137:170476. [PMID: 33370567 PMCID: PMC8025943 DOI: 10.1016/j.peptides.2020.170476] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
Abstract
Given the increased prevalence of obesity and its associated comorbidities, understanding the mechanisms through which the brain regulates energy balance is of critical importance. The neuropeptide melanin-concentrating hormone (MCH) is produced in the lateral hypothalamic area and the adjacent incerto-hypothalamic area and promotes both food intake and energy conservation, overall contributing to body weight gain. Decades of research into this system has provided insight into the neural pathways and mechanisms (behavioral and neurobiological) through which MCH stimulates food intake. Recent technological advancements that allow for selective manipulation of MCH neuron activity have elucidated novel mechanisms of action for the hyperphagic effects of MCH, implicating neural "volume" transmission in the cerebrospinal fluid and sex-specific effects of MCH on food intake control as understudied areas for future investigation. Highlighted here are historical and recent findings that illuminate the neurobiological mechanisms through which MCH promotes food intake, including the identification of various specific neural signaling pathways and interactions with other peptide systems. We conclude with a framework that the hyperphagic effects of MCH signaling are predominantly mediated through enhancement of an "appetition" process in which early postoral prandial signals promote further caloric consumption.
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Affiliation(s)
- Magen N Lord
- Department of Foods and Nutrition, University of Georgia, Athens, GA 30606, USA
| | - Keshav Subramanian
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, Athens, GA 30606, USA.
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26
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Belsham DD, Dalvi PS. Insulin signalling in hypothalamic neurones. J Neuroendocrinol 2020; 33:e12919. [PMID: 33227171 DOI: 10.1111/jne.12919] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 12/15/2022]
Abstract
Subsequent to the discovery of insulin by Banting and Best in the Department of Physiology at the University of Toronto 100 years ago, the field of insulin signalling and action has grown at a remarkable pace. Yet, the recognition that insulin action in the brain is critical for whole body homeostasis has only recently been appreciated. The hypothalamus is a key region in the brain that responds to circulating insulin by engaging a complex signalling cascade resulting in the ultimate release of neuropeptides that control hunger and feeding. Disruption of this important feedback system can lead to a phenomenon called cellular insulin resistance, where the neurones cease to sense insulin. The factors contributing to insulin resistance, as well as the resulting detrimental effects, include the induction of neuroinflammation, endoplasmic reticulum stress and alterations in the architecture of the blood-brain barrier that allow transport of insulin into the brain. These manifestations usually change energy balance, causing weight gain, often resulting in obesity and its deadly comorbidities, including type 2 diabetes mellitus, cardiovascular disease and metabolic syndrome. Nonetheless, there is still hope because the signal transduction pathways can be targeted at a number of levels by neurone-specific therapeutics. With the advent of unique cell models for investigating the mechanisms involved in these processes, the discovery of novel targets is increasingly possible. Although we are still looking for a cure for diabetes, Banting and Best would be impressed at how far their discovery has advanced and the contemporary knowledge that has been accumulated based on insulin action.
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Affiliation(s)
- Denise D Belsham
- Departments of Physiology, Obstetrics and Gynaecology and Medicine, University of Toronto, Toronto, ON, Canada
| | - Prasad S Dalvi
- Biology Department, Morosky College of Health Professions and Sciences, Gannon University, Erie, PA, USA
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Bandaru SS, Khanday MA, Ibrahim N, Naganuma F, Vetrivelan R. Sleep-Wake Control by Melanin-Concentrating Hormone (MCH) Neurons: a Review of Recent Findings. Curr Neurol Neurosci Rep 2020; 20:55. [PMID: 33006677 DOI: 10.1007/s11910-020-01075-x] [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] [Accepted: 09/17/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE OF THE REVIEW Melanin-concentrating hormone (MCH)-expressing neurons located in the lateral hypothalamus are considered as an integral component of sleep-wake circuitry. However, the precise role of MCH neurons in sleep-wake regulation has remained unclear, despite several years of research employing a wide range of techniques. We review recent data on this aspect, which are mostly inconsistent, and propose a novel role for MCH neurons in sleep regulation. RECENT FINDINGS While almost all studies using "gain-of-function" approaches show an increase in rapid eye movement sleep (or paradoxical sleep; PS), loss-of-function approaches have not shown reductions in PS. Similarly, the reported changes in wakefulness or non-rapid eye movement sleep (slow-wave sleep; SWS) with manipulation of the MCH system using conditional genetic methods are inconsistent. Currently available data do not support a role for MCH neurons in spontaneous sleep-wake but imply a crucial role for them in orchestrating sleep-wake responses to changes in external and internal environments.
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Affiliation(s)
- Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA
| | - Mudasir A Khanday
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Nazifa Ibrahim
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.,Department of Public Health Sciences, University of Massachusetts, Amherst, MA, USA
| | - Fumito Naganuma
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.,Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA. .,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
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Wang Y, Wang D, Chen Y, Fang X, Yu L, Zhang C. A Novel Synthetic Interfering Peptide Tat-3L4F Attenuates Olanzapine-Induced Weight Gain Through Disrupting Crosstalk Between Serotonin Receptor 2C and Protein Phosphatase and Tensin Homolog in Rats. Int J Neuropsychopharmacol 2020; 23:481-490. [PMID: 32710540 PMCID: PMC7689208 DOI: 10.1093/ijnp/pyaa001] [Citation(s) in RCA: 4] [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: 08/16/2019] [Revised: 12/29/2019] [Accepted: 01/15/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Accompanied with profound efficacy, atypical antipsychotics (AAPs) contribute to metabolic adverse effects with few effective strategies to attenuate. Serotonin 5-HT2C receptor (HTR2C) plays a critical role in hyperphagia and weight gain induced by AAPs, and expression of phosphatase tensin homolog (PTEN) in the hypothalamus also affects feeding behavior and weight change. Moreover, PTEN has a physical crosstalk between PTEN and a region in the third intracellular loop (3L4F) of the HTR2C. Tat-3L4F has the property to disrupt crosstalk between PTEN and HTR2C. This is the first study to our knowledge to investigate the effect of Tat-3L4F on olanzapine-induced metabolic abnormalities and PTEN/ phosphatidylinositol 3-kinase/protein kinase B expression in the hypothalamus in rats. METHODS The effects of Tat-3L4F were investigated through measuring body weight, food intake, and blood glucose. In addition, PTEN/phosphatidylinositol 3-kinase/protein kinase B level in the hypothalamus was detected by immunofluorescence assay and western blot. Metabolites in the liver tissue were detected by liquid chromatography-mass spectrometry and analyzed by multivariate analyses and pairwise comparison. RESULTS Our results showed that hyperphagia and weight gain were evident in the olanzapine alone-fed rats but was attenuated after Tat-3L4F treatment. In addition, oral glucose tolerance test indicated blood glucose at 120 minutes was higher in the olanzapine alone-treated group than in groups treated with vehicle and olanzapine + Tat-3L4F (10 μmol kg-1 per day). Furthermore, compared with olanzapine alone treatment, treatment with Tat-3L4F (10 μmol kg-1 per day) significantly inhibited PTEN expression in the hypothalamus. The olanzapine alone-treated group had the highest bile acid level, followed by the olanzapine with Tat-3L4F (1 μmol kg-1) group, olanzapine with Tat-3L4F (10 μmol kg-1) group, and vehicle group. CONCLUSIONS Our present results reveal that Tat-3L4F is a potential pharmacological strategy for suppressing hyperphagia and weight gain induced by olanzapine, which acts through disrupting crosstalk between HTR2C and PTEN as a result of PTEN downregulation in the hypothalamus.
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Affiliation(s)
- Yewei Wang
- Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China,Innovative Research Team of High-level Local Universities in Shanghai
| | - Dandan Wang
- Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China,Innovative Research Team of High-level Local Universities in Shanghai
| | - Yan Chen
- Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China,Innovative Research Team of High-level Local Universities in Shanghai
| | - Xinyu Fang
- Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China,Innovative Research Team of High-level Local Universities in Shanghai
| | - Lingfang Yu
- Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China,Innovative Research Team of High-level Local Universities in Shanghai
| | - Chen Zhang
- Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China,Innovative Research Team of High-level Local Universities in Shanghai,Correspondence: Chen Zhang, MD, PhD, Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 600 South Wan Ping Road Shanghai 20030, China ()
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29
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MCH Neurons Regulate Permeability of the Median Eminence Barrier. Neuron 2020; 107:306-319.e9. [PMID: 32407670 PMCID: PMC7383232 DOI: 10.1016/j.neuron.2020.04.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 03/06/2020] [Accepted: 04/20/2020] [Indexed: 01/17/2023]
Abstract
Melanin-concentrating hormone (MCH)-expressing neurons are key regulators of energy and glucose homeostasis. Here, we demonstrate that they provide dense projections to the median eminence (ME) in close proximity to tanycytes and fenestrated vessels. Chemogenetic activation of MCH neurons as well as optogenetic stimulation of their projections in the ME enhance permeability of the ME by increasing fenestrated vascular loops and enhance leptin action in the arcuate nucleus of the hypothalamus (ARC). Unbiased phosphoRiboTrap-based assessment of cell activation upon chemogenetic MCH neuron activation reveals MCH-neuron-dependent regulation of endothelial cells. MCH neurons express the vascular endothelial growth factor A (VEGFA), and blocking VEGF-R signaling attenuates the leptin-sensitizing effect of MCH neuron activation. Our experiments reveal that MCH neurons directly regulate permeability of the ME barrier, linking the activity of energy state and sleep regulatory neurons to the regulation of hormone accessibility to the ARC. MCH neurons provide dense projections to the median eminence MCH neuron activation promotes permeability of the median eminence barrier MCH neuron activation enhances microvessel fenestration in the ME MCH neuron activation enhances leptin action in the arcuate nucleus
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Jais A, Paeger L, Sotelo-Hitschfeld T, Bremser S, Prinzensteiner M, Klemm P, Mykytiuk V, Widdershooven PJM, Vesting AJ, Grzelka K, Minère M, Cremer AL, Xu J, Korotkova T, Lowell BB, Zeilhofer HU, Backes H, Fenselau H, Wunderlich FT, Kloppenburg P, Brüning JC. PNOC ARC Neurons Promote Hyperphagia and Obesity upon High-Fat-Diet Feeding. Neuron 2020; 106:1009-1025.e10. [PMID: 32302532 PMCID: PMC7303947 DOI: 10.1016/j.neuron.2020.03.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/11/2020] [Accepted: 03/23/2020] [Indexed: 12/30/2022]
Abstract
Calorie-rich diets induce hyperphagia and promote obesity, although the underlying mechanisms remain poorly defined. We find that short-term high-fat-diet (HFD) feeding of mice activates prepronociceptin (PNOC)-expressing neurons in the arcuate nucleus of the hypothalamus (ARC). PNOCARC neurons represent a previously unrecognized GABAergic population of ARC neurons distinct from well-defined feeding regulatory AgRP or POMC neurons. PNOCARC neurons arborize densely in the ARC and provide inhibitory synaptic input to nearby anorexigenic POMC neurons. Optogenetic activation of PNOCARC neurons in the ARC and their projections to the bed nucleus of the stria terminalis promotes feeding. Selective ablation of these cells promotes the activation of POMC neurons upon HFD exposure, reduces feeding, and protects from obesity, but it does not affect food intake or body weight under normal chow consumption. We characterize PNOCARC neurons as a novel ARC neuron population activated upon palatable food consumption to promote hyperphagia. Acute high-fat-diet feeding activates PNOC neurons in the arcuate nucleus (ARC) GABAergic PNOCARC neurons inhibit anorexigenic POMC neurons Optogenetic activation of PNOCARC neurons promotes feeding Ablation of PNOCARC neurons protects from obesity
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Affiliation(s)
- Alexander Jais
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Lars Paeger
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Institute for Zoology, Biocenter, University of Cologne, Cologne, Germany
| | - Tamara Sotelo-Hitschfeld
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Stephan Bremser
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Institute for Zoology, Biocenter, University of Cologne, Cologne, Germany
| | - Melanie Prinzensteiner
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Paul Klemm
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Vasyl Mykytiuk
- Neuronal Circuits and Behaviour Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Pia J M Widdershooven
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Anna Juliane Vesting
- Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Obesity and Cancer Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Katarzyna Grzelka
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Marielle Minère
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Anna Lena Cremer
- Multimodal Imaging of Brain Metabolism Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Jie Xu
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Tatiana Korotkova
- Neuronal Circuits and Behaviour Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Bradford B Lowell
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02215, USA
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland; Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, 8093 Zurich, Switzerland
| | - Heiko Backes
- Multimodal Imaging of Brain Metabolism Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Henning Fenselau
- Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - F Thomas Wunderlich
- Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Obesity and Cancer Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany
| | - Peter Kloppenburg
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Institute for Zoology, Biocenter, University of Cologne, Cologne, Germany.
| | - Jens C Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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Wang D, Zhang J, Bai Y, Zheng X, Alizamini MM, Shang W, Yang Q, Li M, Li Y, Sui N. Melanin-concentrating hormone in rat nucleus accumbens or lateral hypothalamus differentially impacts morphine and food seeking behaviors. J Psychopharmacol 2020; 34:478-489. [PMID: 31909693 DOI: 10.1177/0269881119895521] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Identifying neural substrates that are differentially affected by drugs of abuse and natural rewards is key to finding a target for an efficacious treatment for substance abuse. Melanin-concentrating hormone is a polypeptide with an inhibitory effect on the mesolimbic dopamine system. Here we test the hypothesis that melanin-concentrating hormone in the lateral hypothalamus and nucleus accumbens shell is differentially involved in the regulation of morphine and food-rewarded behaviors. METHODS Male Sprague-Dawley rats were trained with morphine (5.0 mg/kg, subcutaneously) or food pellets (standard chow, 10-14 g) to induce a conditioned place preference, immediately followed by extinction training. Melanin-concentrating hormone (1.0 µg/side) or saline was infused into the nucleus accumbens shell or lateral hypothalamus before the reinstatement primed by morphine or food, and locomotor activity was simultaneously monitored. As the comparison, melanin-concentrating hormone was also microinjected into the nucleus accumbens shell or lateral hypothalamus before the expression of food or morphine-induced conditioned place preference. RESULTS Microinfusion of melanin-concentrating hormone into the nucleus accumbens shell (but not into the lateral hypothalamus) prevented the reinstatement of morphine conditioned place preference but had no effect on the reinstatement of food conditioned place preference. In contrast, microinfusion of melanin-concentrating hormone into the lateral hypothalamus (but not in the nucleus accumbens shell) inhibited the reinstatement of food conditioned place preference but had no effect on the reinstatement of morphine conditioned place preference. CONCLUSIONS These results suggest a clear double dissociation of melanin-concentrating hormone in morphine/food rewarding behaviors and melanin-concentrating hormone in the nucleus accumbens shell. Melanin-concentrating hormone could be a potential target for therapeutic intervention for morphine abuse without affecting natural rewards.
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Affiliation(s)
- Dongmei Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Jianjun Zhang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Yunjing Bai
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Xigeng Zheng
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Mirmohammadali M Alizamini
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Wen Shang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Qingxiong Yang
- School of Karst Science, Guizhou Normal University/State Engineering Technology Institute for Karst Desertification Control, Guiyang, China
| | - Ming Li
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Yonghui Li
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Nan Sui
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
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Dilsiz P, Aklan I, Sayar Atasoy N, Yavuz Y, Filiz G, Koksalar F, Ates T, Oncul M, Coban I, Ates Oz E, Cebecioglu U, Alp MI, Yilmaz B, Atasoy D. MCH Neuron Activity Is Sufficient for Reward and Reinforces Feeding. Neuroendocrinology 2020; 110:258-270. [PMID: 31154452 DOI: 10.1159/000501234] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/31/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Melanin-concentrating hormone (MCH)-expressing neurons have been implicated in regulation of energy homeostasis and reward, yet the role of their electrical activity in short-term appetite and reward modulation has not been fully understood. OBJECTIVES We investigated short-term behavioral and physiological effects of MCH neuron activity manipulations. METHODS We used optogenetic and chemogenetic approaches in Pmch-cre transgenic mice to acutely stimulate/inhibit MCH neuronal activity while probing feeding, locomotor activity, anxiety-like behaviors, glucose homeostasis, and reward. RESULTS MCH neuron activity is neither required nor sufficient for short-term appetite unless stimulation is temporally paired with consumption. MCH neuronal activation does not affect short-term locomotor activity, but inhibition improves glucose tolerance and is mildly anxiolytic. Finally, using two different operant tasks, we showed that activation of MCH neurons alone is sufficient to induce reward. CONCLUSIONS Our results confirm diverse behavioral/physiological functions of MCH neurons and suggest a direct role in reward function.
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Affiliation(s)
- Pelin Dilsiz
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Iltan Aklan
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
- Department of Pharmacology, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Nilufer Sayar Atasoy
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
- Department of Pharmacology, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Yavuz Yavuz
- Department of Physiology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Gizem Filiz
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Fulya Koksalar
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Tayfun Ates
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Merve Oncul
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Ilknur Coban
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Edanur Ates Oz
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Utku Cebecioglu
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Muhammed Ikbal Alp
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Bayram Yilmaz
- Department of Physiology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Deniz Atasoy
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey,
- Department of Pharmacology, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA,
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You H, Chu P, Guo W, Lu B. A subpopulation of Bdnf-e1-expressing glutamatergic neurons in the lateral hypothalamus critical for thermogenesis control. Mol Metab 2019; 31:109-123. [PMID: 31918913 PMCID: PMC6920260 DOI: 10.1016/j.molmet.2019.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/16/2019] [Accepted: 11/17/2019] [Indexed: 12/14/2022] Open
Abstract
Objective Brown adipose tissue (BAT)–mediated thermogenesis plays a key role in energy homeostasis and the maintenance of body temperature. Previous work suggests that brain-derived neurotrophic factor (BDNF) is involved in BAT thermogenesis, but the underlying neural circuits and molecular mechanism remain largely unknown. This is in part due to the difficulties in manipulating BDNF expression in different brain regions through different promoters and the lack of tools to identify neurons in the brain specifically involved in BAT thermogenesis. Methods We have created several lines of mutant mice in which BDNF transcription from a specific promoter was selectively disrupted by replacing Bdnf with green fluorescent protein (GFP; Bdnf-e1, -e4, and -e6−/− mice). As such, cells expressing Bdnf-e1, -e4, or -e6 were labeled with GFP. To identify BAT-connected thermogenesis neurons in brain, we applied the retrograde pseudorabies virus labeling method from BAT. We also used chemogenetic tools to manipulate specific neurons coupled with BAT temperature recording. Moreover, we developed a new TrkB agonist antibody to rescue the BAT thermogenesis deficits. Results We show that selective disruption of Bdnf expression from promoter 1 (Bdnf-e1) resulted in severe obesity and deficits of BAT-mediated thermogenesis. Body temperature response to cold was impaired in Bdnf-e1−/− mice. BAT expression of Ucp1 and Pcg1a, genes known to regulate thermogenesis, was also reduced, accompanying a decrease in the sympathetic activity of BAT. Staining of cells expressing Bdnf-e1 transcript, combined with transsynaptic, retrograde-tracing labeling of BAT-connected neurons, identified a group of excitatory neurons in lateral hypothalamus (LH) critical for thermogenesis regulation. Moreover, an adaptive thermogenesis defect in Bdnf-e1−/− mice was rescued by injecting an agonistic antibody for TrkB, the BDNF receptor, into LH. Remarkably, activation of the excitatory neurons (VGLUT2+) in LH through chemogenetic tools resulted in a rise of BAT temperature. Conclusions These results reveal a specific role of BDNF promoter I in thermogenesis regulation and define a small subset of neurons in LH that contribute to such regulation. Only Bdnf-e1−/−, but not Bdnf-e4−/− or Bdnf-e6−/−, mutant mice exhibited deficiencies of BAT thermogenesis. Neurons that are both Bdnf-e1 expressing and BAT-connected were found only in LH. BAT-connected neurons in LH are glutamatergic. Activation of the LH glutamatergic neurons resulted in an increase in BAT temperature. Administration of TrkB agonist antibody in LH rescued thermogenesis deficits.
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Affiliation(s)
- He You
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Pengcheng Chu
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wei Guo
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China
| | - Bai Lu
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China.
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Chee MJ, Hebert AJ, Briançon N, Flaherty SE, Pissios P, Maratos-Flier E. Conditional deletion of melanin-concentrating hormone receptor 1 from GABAergic neurons increases locomotor activity. Mol Metab 2019; 29:114-123. [PMID: 31668382 PMCID: PMC6745487 DOI: 10.1016/j.molmet.2019.08.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/23/2019] [Accepted: 08/25/2019] [Indexed: 12/28/2022] Open
Abstract
Objective Melanin-concentrating hormone (MCH) plays a key role in regulating energy balance. MCH acts via its receptor MCHR1, and MCHR1 deletion increases energy expenditure and locomotor activity, which is associated with a hyperdopaminergic state. Since MCHR1 expression is widespread, the neurons supporting the effects of MCH on energy expenditure are not clearly defined. There is a high density of MCHR1 neurons in the striatum, and these neurons are known to be GABAergic. We thus determined if MCH acts via this GABAergic neurocircuit to mediate energy balance. Methods We generated a Mchr1-flox mouse and crossed it with the Vgat-cre mouse to assess if MCHR1 deletion from GABAergic neurons expressing the vesicular GABA transporter (vGAT) in female Vgat-Mchr1-KO mice resulted in lower body weights or increased energy expenditure. Additionally, we determined if MCHR1-expressing neurons within the accumbens form part of the neural circuit underlying MCH-mediated energy balance by delivering an adeno-associated virus expressing Cre recombinase to the accumbens nucleus of Mchr1-flox mice. To evaluate if a dysregulated dopaminergic tone leads to their hyperactivity, we determined if the dopamine reuptake blocker GBR12909 prolonged the drug-induced locomotor activity in Vgat-Mchr1-KO mice. Furthermore, we also performed amperometry recordings to test whether MCHR1 deletion increases dopamine output within the accumbens and whether MCH can suppress dopamine release. Results Vgat-Mchr1-KO mice have lower body weight, increased energy expenditure, and increased locomotor activity. Similarly, restricting MCHR1 deletion to the accumbens nucleus also increased locomotor activity. Vgat-Mchr1-KO mice show increased and prolonged sensitivity to GBR12909-induced locomotor activity, and amperometry recordings revealed that GBR12909 elevated accumbens dopamine levels to twice that of controls, thus MCHR1 deletion may lead to a hyperdopaminergic state that mediates their observed hyperactivity. Consistent with the inhibitory effect of MCH, we found that MCH acutely suppresses dopamine release within the accumbens. Conclusions As with established models of systemic MCH or MCHR1 deletion, we found that MCHR1 deletion from GABAergic neurons, specifically those within the accumbens nucleus, also led to increased locomotor activity. A hyperdopaminergic state underlies this increased locomotor activity, and is consistent with our finding that MCH signaling within the accumbens nucleus suppresses dopamine release. In effect, MCHR1 deletion may disinhibit dopamine release leading to the observed hyperactivity. Generation of Mchr1-flox mouse enabled cre-mediated deletion of Mchr1. Mchr1 deletion at GABAergic neurons decreased body weight. Mchr1 deletion at GABAergic neurons increased locomotor activity. Mchr1 deletion increased dopaminergic tone in the mesolimbic accumbens circuitry. MCH suppressed dopamine release in the accumbens nucleus.
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Affiliation(s)
- Melissa J Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada; Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| | - Alex J Hebert
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada; Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Nadege Briançon
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Stephen E Flaherty
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Pavlos Pissios
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Eleftheria Maratos-Flier
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Kosse C, Burdakov D. Natural hypothalamic circuit dynamics underlying object memorization. Nat Commun 2019; 10:2505. [PMID: 31175285 PMCID: PMC6555780 DOI: 10.1038/s41467-019-10484-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/08/2019] [Indexed: 12/23/2022] Open
Abstract
Brain signals that govern memory formation remain incompletely identified. The hypothalamus is implicated in memory disorders, but how its rapidly changing activity shapes memorization is unknown. During encounters with objects, hypothalamic melanin-concentrating hormone (MCH) neurons emit brief signals that reflect object novelty. Here we show that targeted optogenetic silencing of these signals, performed selectively during the initial object encounters (i.e. memory acquisition), prevents future recognition of the objects. We identify an upstream inhibitory microcircuit from hypothalamic GAD65 neurons to MCH neurons, which constrains the memory-promoting MCH cell bursts. Finally, we demonstrate that silencing the GAD65 cells during object memory acquisition improves future object recognition through MCH-receptor-dependent pathways. These results provide causal evidence that object-associated signals in genetically distinct but interconnected hypothalamic neurons differentially control whether the brain forms object memories. This gating of memory formation by hypothalamic activity establishes appropriate behavioral responses to novel and familiar objects.
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Affiliation(s)
- Christin Kosse
- The Francis Crick Institute, London, NW1 1AT, UK
- Laboratory of Molecular Genetics, The Rockefeller University, New York, NY, 10065, USA
| | - Denis Burdakov
- The Francis Crick Institute, London, NW1 1AT, UK.
- Neurobehavioural Dynamics Lab, Institute for Neuroscience, D-HEST, Swiss Federal Institute of Technology / ETH Zürich, Zürich, 8603, Switzerland.
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Jeong JK, Horwath JA, Simonyan H, Blackmore KA, Butler SD, Young CN. Subfornical organ insulin receptors tonically modulate cardiovascular and metabolic function. Physiol Genomics 2019; 51:333-341. [PMID: 31172876 DOI: 10.1152/physiolgenomics.00021.2019] [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] [Indexed: 01/28/2023] Open
Abstract
Insulin acts within the central nervous system through the insulin receptor to influence both metabolic and cardiovascular physiology. While a major focus has been placed on hypothalamic regions, participation of extrahypothalamic insulin receptors in cardiometabolic regulation remains largely unknown. We hypothesized that insulin receptors in the subfornical organ (SFO), a forebrain circumventricular region devoid of a blood-brain barrier, are involved in metabolic and cardiovascular regulation. Immunohistochemistry in mice revealed widespread insulin receptor-positive cells throughout the rostral to caudal extent of the SFO. SFO-targeted adenoviral delivery of Cre-recombinase in insulin receptorlox/lox mice resulted in sufficient ablation of insulin receptors in the SFO. Interestingly, when mice were maintained on a normal chow diet, deletion of SFO insulin receptors resulted in greater weight gain and adiposity, relative to controls, independently of changes in food intake. In line with this, ablation of insulin receptors in the SFO was associated with marked hepatic steatosis and hypertriglyceridemia. Selective removal of SFO insulin receptors also resulted in a lower mean arterial blood pressure, which was primarily due to a reduction in diastolic blood pressure, whereas systolic blood pressure remained unchanged. Cre-mediated targeting of SFO insulin receptors did not influence heart rate. These data demonstrate multidirectional roles for insulin receptor signaling in the SFO, with ablation of SFO insulin receptors resulting in an overall deleterious metabolic state while at the same time maintaining blood pressure at low levels. These novel findings further suggest that alterations in insulin receptor signaling in the SFO could contribute to metabolic syndrome phenotypes.
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Affiliation(s)
- Jin Kwon Jeong
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Julie A Horwath
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Katherine A Blackmore
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Scott D Butler
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
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Arrigoni E, Chee MJS, Fuller PM. To eat or to sleep: That is a lateral hypothalamic question. Neuropharmacology 2018; 154:34-49. [PMID: 30503993 DOI: 10.1016/j.neuropharm.2018.11.017] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 12/15/2022]
Abstract
The lateral hypothalamus (LH) is a functionally and anatomically complex brain region that is involved in the regulation of many behavioral and physiological processes including feeding, arousal, energy balance, stress, reward and motivated behaviors, pain perception, body temperature regulation, digestive functions and blood pressure. Despite noteworthy experimental efforts over the past decades, the circuit, cellular and synaptic bases by which these different processes are regulated by the LH remains incompletely understood. This knowledge gap links in large part to the high cellular heterogeneity of the LH. Fortunately, the rapid evolution of newer genetic and electrophysiological tools is now permitting the selective manipulation, typically genetically-driven, of discrete LH cell populations. This, in turn, permits not only assignment of function to discrete cell groups, but also reveals that considerable synergistic and antagonistic interactions exist between key LH cell populations that regulate feeding and arousal. For example, we now know that while LH melanin-concentrating hormone (MCH) and orexin/hypocretin neurons both function as sensors of the internal metabolic environment, their roles regulating sleep and arousal are actually opposing. Additional studies have uncovered similarly important roles for subpopulations of LH GABAergic cells in the regulation of both feeding and arousal. Herein we review the role of LH MCH, orexin/hypocretin and GABAergic cell populations in the regulation of energy homeostasis (including feeding) and sleep-wake and discuss how these three cell populations, and their subpopulations, may interact to optimize and coordinate metabolism, sleep and arousal. This article is part of the Special Issue entitled 'Hypothalamic Control of Homeostasis'.
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Affiliation(s)
- Elda Arrigoni
- Department of Neurology, Beth Israel Deaconess Medical Center, Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02215, USA.
| | - Melissa J S Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Patrick M Fuller
- Department of Neurology, Beth Israel Deaconess Medical Center, Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02215, USA
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Latifi B, Adamantidis A, Bassetti C, Schmidt MH. Sleep-Wake Cycling and Energy Conservation: Role of Hypocretin and the Lateral Hypothalamus in Dynamic State-Dependent Resource Optimization. Front Neurol 2018; 9:790. [PMID: 30344503 PMCID: PMC6183196 DOI: 10.3389/fneur.2018.00790] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/31/2018] [Indexed: 12/23/2022] Open
Abstract
The hypocretin (Hcrt) system has been implicated in a wide range of physiological functions from sleep-wake regulation to cardiovascular, behavioral, metabolic, and thermoregulagtory control. These wide-ranging physiological effects have challenged the identification of a parsimonious function for Hcrt. A compelling hypothesis suggests that Hcrt plays a role in the integration of sleep-wake neurophysiology with energy metabolism. For example, Hcrt neurons promote waking and feeding, but are also sensors of energy balance. Loss of Hcrt function leads to an increase in REM sleep propensity, but a potential role for Hcrt linking energy balance with REM sleep expression has not been addressed. Here we examine a potential role for Hcrt and the lateral hypothalamus (LH) in state-dependent resource allocation as a means of optimizing resource utilization and, as a result, energy conservation. We review the energy allocation hypothesis of sleep and how state-dependent metabolic partitioning may contribute toward energy conservation, but with additional examination of how the loss of thermoregulatory function during REM sleep may impact resource optimization. Optimization of energy expenditures at the whole organism level necessitates a top-down network responsible for coordinating metabolic operations in a state-dependent manner across organ systems. In this context, we then specifically examine the potential role of the LH in regulating this output control, including the contribution from both Hcrt and melanin concentrating hormone (MCH) neurons among a diverse LH cell population. We propose that this hypothalamic integration system is responsible for global shifts in state-dependent resource allocations, ultimately promoting resource optimization and an energy conservation function of sleep-wake cycling.
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Affiliation(s)
- Blerina Latifi
- Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Antoine Adamantidis
- Department of Neurology, Center for Experimental Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Department of Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Claudio Bassetti
- Department of Neurology, Center for Experimental Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Markus H Schmidt
- Department of Neurology, Center for Experimental Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Ohio Sleep Medicine Institute, Dublin, OH, United States
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Abstract
Chemogenetic technologies enable selective pharmacological control of specific cell populations. An increasing number of approaches have been developed that modulate different signaling pathways. Selective pharmacological control over G protein-coupled receptor signaling, ion channel conductances, protein association, protein stability, and small molecule targeting allows modulation of cellular processes in distinct cell types. Here, we review these chemogenetic technologies and instances of their applications in complex tissues in vivo and ex vivo.
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Affiliation(s)
- Deniz Atasoy
- Department of Physiology, School of Medicine and Regenerative-Restorative Medicine Research Center (REMER), Istanbul Medipol University , Istanbul , Turkey ; and Janelia Research Campus, Howard Hughes Medical Institute , Ashburn, Virginia
| | - Scott M Sternson
- Department of Physiology, School of Medicine and Regenerative-Restorative Medicine Research Center (REMER), Istanbul Medipol University , Istanbul , Turkey ; and Janelia Research Campus, Howard Hughes Medical Institute , Ashburn, Virginia
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Alvarsson A, Stanley SA. Remote control of glucose-sensing neurons to analyze glucose metabolism. Am J Physiol Endocrinol Metab 2018; 315:E327-E339. [PMID: 29812985 PMCID: PMC6171010 DOI: 10.1152/ajpendo.00469.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/25/2018] [Accepted: 05/23/2018] [Indexed: 12/13/2022]
Abstract
The central nervous system relies on a continual supply of glucose, and must be able to detect glucose levels and regulate peripheral organ functions to ensure that its energy requirements are met. Specialized glucose-sensing neurons, first described half a century ago, use glucose as a signal and modulate their firing rates as glucose levels change. Glucose-excited neurons are activated by increasing glucose concentrations, while glucose-inhibited neurons increase their firing rate as glucose concentrations fall and decrease their firing rate as glucose concentrations rise. Glucose-sensing neurons are present in multiple brain regions and are highly expressed in hypothalamic regions, where they are involved in functions related to glucose homeostasis. However, the roles of glucose-sensing neurons in healthy and disease states remain poorly understood. Technologies that can rapidly and reversibly activate or inhibit defined neural populations provide invaluable tools to investigate how specific neural populations regulate metabolism and other physiological roles. Optogenetics has high temporal and spatial resolutions, requires implants for neural stimulation, and is suitable for modulating local neural populations. Chemogenetics, which requires injection of a synthetic ligand, can target both local and widespread populations. Radio- and magnetogenetics offer rapid neural activation in localized or widespread neural populations without the need for implants or injections. These tools will allow us to better understand glucose-sensing neurons and their metabolism-regulating circuits.
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Affiliation(s)
- Alexandra Alvarsson
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai , New York, New York
| | - Sarah A Stanley
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai , New York, New York
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, New York
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p53 in AgRP neurons is required for protection against diet-induced obesity via JNK1. Nat Commun 2018; 9:3432. [PMID: 30143607 PMCID: PMC6109113 DOI: 10.1038/s41467-018-05711-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/19/2018] [Indexed: 12/13/2022] Open
Abstract
p53 is a well-known tumor suppressor that has emerged as an important player in energy balance. However, its metabolic role in the hypothalamus remains unknown. Herein, we show that mice lacking p53 in agouti-related peptide (AgRP), but not proopiomelanocortin (POMC) or steroidogenic factor-1 (SF1) neurons, are more prone to develop diet-induced obesity and show reduced brown adipose tissue (BAT) thermogenic activity. AgRP-specific ablation of p53 resulted in increased hypothalamic c-Jun N-terminal kinase (JNK) activity before the mice developed obesity, and central inhibition of JNK reversed the obese phenotype of these mice. The overexpression of p53 in the ARC or specifically in AgRP neurons of obese mice decreased body weight and stimulated BAT thermogenesis, resulting in body weight loss. Finally, p53 in AgRP neurons regulates the ghrelin-induced food intake and body weight. Overall, our findings provide evidence that p53 in AgRP neurons is required for normal adaptations against diet-induced obesity. Emerging studies suggest that p53 is an important regulator of energy metabolism, yet there is little known about the metabolic function of this tumor suppressor in the hypothalamus. Here, authors illustrate that p53, specifically in AgRP neurons, is required for adaptation to diet-induced obesity.
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Mendes NF, Gaspar JM, Lima-Júnior JC, Donato J, Velloso LA, Araújo EP. TGF-β1 down-regulation in the mediobasal hypothalamus attenuates hypothalamic inflammation and protects against diet-induced obesity. Metabolism 2018; 85:171-182. [PMID: 29660453 DOI: 10.1016/j.metabol.2018.04.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/01/2018] [Accepted: 04/10/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND The consumption of large amounts of dietary fats induces hypothalamic inflammation and impairs the function of the melanocortin system, leading to a defective regulation of caloric intake and whole-body energy expenditure. In mice fed a high-fat diet (HFD), TGF-β1 expression was increased and NF-κB signaling was activated in proopiomelanocortin neurons, which plays an important role in the obesity-associated hypothalamic inflammation scenario. However, whether excessive hypothalamic TGF-β1 impairs energy homeostasis remains unclear. OBJECTIVES We aimed to investigate the role of diet-induced hypothalamic TGF-β1 on inflammation and whole-body energy homeostasis. METHODS A TGF-β1 inhibitory lentiviral shRNA particle was stereotaxically injected bilaterally in the arcuate nucleus (ARC) of C57BL/6 mice fed a HFD. We assessed changes in body mass and adiposity, food intake, inflammatory markers, and the function of energy and glucose metabolism. RESULTS TGF-β1 down-regulation in the ARC-attenuated body-mass gain, reduced fat-mass accumulation, decreased hypothalamic inflammatory markers, and protected against HFD-induced lipohypertrophy of brown adipose tissue. In addition, the inhibition of hypothalamic TGF-β1 increased the locomotor activity and improved whole-body lipid metabolism, which attenuated hepatic fat accumulation and serum triglyceride levels. No changes were observed in food intake and glucose homeostasis. CONCLUSION Hypothalamic TGF-β1 down-regulation attenuates hypothalamic inflammation and improves energy metabolism, resulting in lower body-mass gain and lower fat-mass accumulation, which protects mice from the development of obesity. Our data suggest that modulation of hypothalamic TGF-β1 expression might be an effective strategy to treat obesity.
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Affiliation(s)
- Natália F Mendes
- School of Nursing, State University of Campinas (UNICAMP), Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Brazil
| | - Joana M Gaspar
- Faculty of Medical Sciences, State University of Campinas (UNICAMP), Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Brazil
| | - José C Lima-Júnior
- Faculty of Medical Sciences, State University of Campinas (UNICAMP), Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Brazil
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Lício A Velloso
- Faculty of Medical Sciences, State University of Campinas (UNICAMP), Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Brazil
| | - Eliana P Araújo
- School of Nursing, State University of Campinas (UNICAMP), Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Brazil.
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Abstract
In contrast to synaptic transmission, the mechanism of volume transmission-in which neurotransmitters or neuropeptides diffuse to many effector cells-is not extensively investigated, although it represents an important mode of neuronal communication. In this issue of Cell Metabolism, Noble et al. (2018) demonstrate how the orexigenic melanin-concentrating hormone (MCH) controls feeding behavior through cerebrospinal fluid (CSF) volume transmission.
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Affiliation(s)
- Hong Jiang
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Jens C Brüning
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany.
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Schneeberger M, Tan K, Nectow AR, Parolari L, Caglar C, Azevedo E, Li Z, Domingos A, Friedman JM. Functional analysis reveals differential effects of glutamate and MCH neuropeptide in MCH neurons. Mol Metab 2018; 13:83-89. [PMID: 29843980 PMCID: PMC6026325 DOI: 10.1016/j.molmet.2018.05.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 04/25/2018] [Accepted: 05/03/2018] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES Melanin-concentrating hormone (MCH) neurons in the lateral hypothalamus (LH) regulate food intake and body weight, glucose metabolism and convey the reward value of sucrose. In this report, we set out to establish the respective roles of MCH and conventional neurotransmitters in these neurons. METHODS MCH neurons were profiled using Cre-dependent molecular profiling technologies (vTRAP). MCHCre mice crossed to Vglut2fl/flmice or to DTRfl/flwere used to identify the role of glutamate in MCH neurons. We assessed metabolic parameters such as body composition, glucose tolerance, or sucrose preference. RESULTS We found that nearly all MCH neurons in the LH are glutamatergic and that a loss of glutamatergic signaling from MCH neurons from a glutamate transporter (VGlut2) knockout leads to a reduced weight, hypophagia and hyperkinetic behavior with improved glucose tolerance and a loss of sucrose preference. These effects are indistinguishable from those seen after ablation of MCH neurons. These findings are in contrast to those seen in mice with a knockout of the MCH neuropeptide, which show normal glucose preference and do not have improved glucose tolerance. CONCLUSIONS Overall, these data show that the vast majority of MCH neurons are glutamatergic, and that glutamate and MCH signaling mediate partially overlapping functions by these neurons, presumably by activating partially overlapping postsynaptic populations. The diverse functional effects of MCH neurons are thus mediated by a composite of glutamate and MCH signaling.
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Affiliation(s)
- Marc Schneeberger
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Keith Tan
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA; A*Star Institute of Medical Biology, 1 Fusionopolis Way, #20-10 Connexis North Tower, Singapore, 138632, Singapore
| | - Alexander R Nectow
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA; Princeton Neuroscience institute, Princeton University, Princeton, NJ, 08544-2098, USA
| | - Luca Parolari
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Caner Caglar
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Estefania Azevedo
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Zhiying Li
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Ana Domingos
- Obesity Laboratory, Instituto Gulbenkian de Ciência, Oeiras, 2780-156, Portugal
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
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Effect of developmental NMDAR antagonism with CGP 39551 on aspartame-induced hypothalamic and adrenal gene expression. PLoS One 2018; 13:e0194416. [PMID: 29561882 PMCID: PMC5862471 DOI: 10.1371/journal.pone.0194416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/04/2018] [Indexed: 01/16/2023] Open
Abstract
Rationale Aspartame (L-aspartyl phenylalanine methyl ester) is a non-nutritive sweetener (NNS) approved for use in more than 6000 dietary products and pharmaceuticals consumed by the general public including adults and children, pregnant and nursing mothers. However a recent prospective study reported a doubling of the risk of being overweight amongst 1-year old children whose mothers consumed NNS-sweetened beverages daily during pregnancy. We have previously shown that chronic aspartame (ASP) exposure commencing in utero may detrimentally affect adulthood adiposity status, glucose metabolism and aspects of behavior and spatial cognition, and that this can be modulated by developmental N-methyl-D-aspartate receptor (NMDAR) blockade with the competitive antagonist CGP 39551 (CGP). Since glucose homeostasis and certain aspects of behavior and locomotion are regulated in part by the NMDAR-rich hypothalamus, which is part of the hypothalamic-pituitary-adrenal- (HPA) axis, we have elected to examine changes in hypothalamic and adrenal gene expression in response to ASP exposure in the presence or absence of developmental NMDAR antagonism with CGP, using Affymetrix microarray analysis. Results Using 2-factor ANOVA we identified 189 ASP-responsive differentially expressed genes (DEGs) in the adult male hypothalamus and 2188 in the adrenals, and a further 23 hypothalamic and 232 adrenal genes significantly regulated by developmental treatment with CGP alone. ASP exposure robustly elevated the expression of a network of genes involved in hypothalamic neurosteroidogenesis, together with cell stress and inflammatory genes, consistent with previous reports of aspartame-induced CNS stress and oxidative damage. These genes were not differentially expressed in ASP mice with CGP antagonism. In the adrenal glands of ASP-exposed mice, GABA and Glutamate receptor subunit genes were amongst those most highly upregulated. Developmental NMDAR antagonism alone had less effect on adulthood gene expression and affected mainly hypothalamic neurogenesis and adrenal steroid metabolism. Combined ASP + CGP treatment mainly upregulated genes involved in adrenal drug and cholesterol metabolism. Conclusion ASP exposure increased the expression of functional networks of genes involved in hypothalamic neurosteroidogenesis and adrenal catecholamine synthesis, patterns of expression which were not present in ASP-exposed mice with developmental NMDAR antagonism.
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Li M, Sirko S. Traumatic Brain Injury: At the Crossroads of Neuropathology and Common Metabolic Endocrinopathies. J Clin Med 2018. [PMID: 29538298 PMCID: PMC5867585 DOI: 10.3390/jcm7030059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Building on the seminal work by Geoffrey Harris in the 1970s, the neuroendocrinology field, having undergone spectacular growth, has endeavored to understand the mechanisms of hormonal connectivity between the brain and the rest of the body. Given the fundamental role of the brain in the orchestration of endocrine processes through interactions among neurohormones, it is thus not surprising that the structural and/or functional alterations following traumatic brain injury (TBI) can lead to endocrine changes affecting the whole organism. Taking into account that systemic hormones also act on the brain, modifying its structure and biochemistry, and can acutely and chronically affect several neurophysiological endpoints, the question is to what extent preexisting endocrine dysfunction may set the stage for an adverse outcome after TBI. In this review, we provide an overview of some aspects of three common metabolic endocrinopathies, e.g., diabetes mellitus, obesity, and thyroid dysfunction, and how these could be triggered by TBI. In addition, we discuss how the complex endocrine networks are woven into the responses to sudden changes after TBI, as well as some of the potential mechanisms that, separately or synergistically, can influence outcomes after TBI.
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Affiliation(s)
- Melanie Li
- Physiological Genomics, Biomedical Center (BMC), Institute of Physiology, Medical Faculty of the Ludwig-Maximilian University Munich, 82152 Planegg-Martinsried, Germany.
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center (BMC), Institute of Physiology, Medical Faculty of the Ludwig-Maximilian University Munich, 82152 Planegg-Martinsried, Germany.
- Institute of Stem Cell Research, Helmholtz Center Munich, Research Center for Environmental Health GmbH, 85764 Neuherberg, Germany.
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Insulin-Sensitizer Effects of Fenugreek Seeds in Parallel with Changes in Plasma MCH Levels in Healthy Volunteers. Int J Mol Sci 2018. [PMID: 29518003 PMCID: PMC5877632 DOI: 10.3390/ijms19030771] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In developed, developing and low-income countries alike, type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases, the severity of which is substantially a consequence of multiple organ complications that occur due to long-term progression of the disease before diagnosis and treatment. Despite enormous investment into the characterization of the disease, its long-term management remains problematic, with those afflicted enduring significant degradation in quality-of-life. Current research efforts into the etiology and pathogenesis of T2DM, are focused on defining aberrations in cellular physiology that result in development of insulin resistance and strategies for increasing insulin sensitivity, along with downstream effects on T2DM pathogenesis. Ongoing use of plant-derived naturally occurring materials to delay the onset of the disease or alleviate symptoms is viewed by clinicians as particularly desirable due to well-established efficacy and minimal toxicity of such preparations, along with generally lower per-patient costs, in comparison to many modern pharmaceuticals. A particularly attractive candidate in this respect, is fenugreek, a plant that has been used as a flavouring in human diet through recorded history. The present study assessed the insulin-sensitizing effect of fenugreek seeds in a cohort of human volunteers, and tested a hypothesis that melanin-concentrating hormone (MCH) acts as a critical determinant of this effect. A test of the hypothesis was undertaken using a hyperinsulinemic euglycemic glucose clamp approach to assess insulin sensitivity in response to oral administration of a fenugreek seed preparation to healthy subjects. Outcomes of these evaluations demonstrated significant improvement in glucose tolerance, especially in patients with impaired glucose responses. Outcome data further suggested that fenugreek seed intake-mediated improvement in insulin sensitivity correlated with reduction in MCH levels.
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Dodd GT, Tiganis T. Insulin action in the brain: Roles in energy and glucose homeostasis. J Neuroendocrinol 2017; 29. [PMID: 28758251 DOI: 10.1111/jne.12513] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/05/2017] [Accepted: 07/26/2017] [Indexed: 12/14/2022]
Abstract
A growing body of evidence from research in rodents and humans has identified insulin as an important neuoregulatory peptide in the brain, where it coordinates diverse aspects of energy balance and peripheral glucose homeostasis. This review discusses where and how insulin interacts within the brain and evaluates the physiological and pathophysiological consequences of central insulin signalling in metabolism, obesity and type 2 diabetes.
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Affiliation(s)
- G T Dodd
- Metabolic Disease and Obesity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
| | - T Tiganis
- Metabolic Disease and Obesity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
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Cyclocarya paliurus (Batal.) Ijinskaja Aqueous Extract (CPAE) Ameliorates Obesity by Improving Insulin Signaling in the Hypothalamus of a Metabolic Syndrome Rat Model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:4602153. [PMID: 28684967 PMCID: PMC5480046 DOI: 10.1155/2017/4602153] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/28/2017] [Accepted: 05/15/2017] [Indexed: 12/19/2022]
Abstract
Background Antiobesity drugs may not be optimal for treating obesity. However novel antiobesity agents, especially those derived from natural products, may be suitable. Therefore, we investigated the effects and mechanisms of Cyclocarya paliurus (CP) aqueous extract (CPAE) on obesity. Methods SHR.Cg-Leprcp/NDmcr (SHR/cp) rats were used as a model of obesity and metabolic syndrome. Experimental animals were allocated into two groups—control and CPAE (0.5 g/kg)—for a 7-week treatment period. Examinations were performed, including general physiological characteristics, obesity-related biochemical parameters, and insulin-signaling pathway-related proteins in the hypothalamus. Results Treatment with CPAE reduced food intake, body weight, organ weight, fat mass, and body mass index (BMI) in SHR/cp rats. Meanwhile, CPAE also decreased the levels of fasting serum glucose, fasting serum insulin, HOMA-IR, serum free fatty acids, serum malondialdehyde, serum superoxide dismutase, and serum total-glutathione. The levels of phosphorylation of target proteins—including InsR, IRS1, PI3Kp85, Akt, and FoXO1 as well as protein expression of POMC—were significantly upregulated in the hypothalamus, but NPY expression remarkably decreased. Conclusions CPAE has antiobesity, antihypoglycemic, antihypolipidemic, and antioxidant properties. The mechanism responsible for the antiobesity effect of CPAE may be related to suppression of energy intake via regulation of insulin-signaling pathway in the hypothalamus.
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50
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Diniz GB, Bittencourt JC. The Melanin-Concentrating Hormone as an Integrative Peptide Driving Motivated Behaviors. Front Syst Neurosci 2017; 11:32. [PMID: 28611599 PMCID: PMC5447028 DOI: 10.3389/fnsys.2017.00032] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/04/2017] [Indexed: 12/14/2022] Open
Abstract
The melanin-concentrating hormone (MCH) is an important peptide implicated in the control of motivated behaviors. History, however, made this peptide first known for its participation in the control of skin pigmentation, from which its name derives. In addition to this peripheral role, MCH is strongly implicated in motivated behaviors, such as feeding, drinking, mating and, more recently, maternal behavior. It is suggested that MCH acts as an integrative peptide, converging sensory information and contributing to a general arousal of the organism. In this review, we will discuss the various aspects of energy homeostasis to which MCH has been associated to, focusing on the different inputs that feed the MCH peptidergic system with information regarding the homeostatic status of the organism and the exogenous sensory information that drives this system, as well as the outputs that allow MCH to act over a wide range of homeostatic and behavioral controls, highlighting the available morphological and hodological aspects that underlie these integrative actions. Besides the well-described role of MCH in feeding behavior, a prime example of hypothalamic-mediated integration, we will also examine those functions in which the participation of MCH has not yet been extensively characterized, including sexual, maternal, and defensive behaviors. We also evaluated the available data on the distribution of MCH and its function in the context of animals in their natural environment. Finally, we briefly comment on the evidence for MCH acting as a coordinator between different modalities of motivated behaviors, highlighting the most pressing open questions that are open for investigations and that could provide us with important insights about hypothalamic-dependent homeostatic integration.
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Affiliation(s)
- Giovanne B. Diniz
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São PauloSão Paulo, Brazil
| | - Jackson C. Bittencourt
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São PauloSão Paulo, Brazil
- Center for Neuroscience and Behavior, Institute of Psychology, University of São PauloSão Paulo, Brazil
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