1
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Ryu V, Gumerova AA, Witztum R, Korkmaz F, Cullen L, Kannangara H, Moldavski O, Barak O, Lizneva D, Goosens KA, Stanley S, Kim SM, Yuen T, Zaidi M. An atlas of brain-bone sympathetic neural circuits in mice. eLife 2024; 13:e95727. [PMID: 38963696 PMCID: PMC11245306 DOI: 10.7554/elife.95727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 06/27/2024] [Indexed: 07/05/2024] Open
Abstract
There is clear evidence that the sympathetic nervous system (SNS) mediates bone metabolism. Histological studies show abundant SNS innervation of the periosteum and bone marrow-these nerves consist of noradrenergic fibers that immunostain for tyrosine hydroxylase, dopamine beta-hydroxylase, or neuropeptide Y. Nonetheless, the brain sites that send efferent SNS outflow to the bone have not yet been characterized. Using pseudorabies (PRV) viral transneuronal tracing, we report, for the first time, the identification of central SNS outflow sites that innervate bone. We find that the central SNS outflow to bone originates from 87 brain nuclei, sub-nuclei, and regions of six brain divisions, namely the midbrain and pons, hypothalamus, hindbrain medulla, forebrain, cerebral cortex, and thalamus. We also find that certain sites, such as the raphe magnus (RMg) of the medulla and periaqueductal gray (PAG) of the midbrain, display greater degrees of PRV152 infection, suggesting that there is considerable site-specific variation in the levels of central SNS outflow to the bone. This comprehensive compendium illustrating the central coding and control of SNS efferent signals to bone should allow for a greater understanding of the neural regulation of bone metabolism, and importantly and of clinical relevance, mechanisms for central bone pain.
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Affiliation(s)
- Vitaly Ryu
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Anisa Azatovna Gumerova
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Ronit Witztum
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Funda Korkmaz
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Liam Cullen
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Hasni Kannangara
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Ofer Moldavski
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Orly Barak
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Daria Lizneva
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Ki A Goosens
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Psychiatry, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Sarah Stanley
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Se-Min Kim
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Tony Yuen
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Mone Zaidi
- Center for Translational Medicine and Pharmacology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
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2
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de Winne C, Pascual FL, Lopez-Vicchi F, Etcheverry-Boneo L, Mendez-Garcia LF, Ornstein AM, Lacau-Mengido IM, Sorianello E, Becu-Villalobos D. Neuroendocrine control of brown adipocyte function by prolactin and growth hormone. J Neuroendocrinol 2024; 36:e13248. [PMID: 36932836 DOI: 10.1111/jne.13248] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 02/08/2023] [Accepted: 02/11/2023] [Indexed: 03/06/2023]
Abstract
Growth hormone (GH) is fundamental for growth and glucose homeostasis, and prolactin for optimal pregnancy and lactation outcome, but additionally, both hormones have multiple functions that include a strong impact on energetic metabolism. In this respect, prolactin and GH receptors have been found in brown, and white adipocytes, as well as in hypothalamic centers regulating thermogenesis. This review describes the neuroendocrine control of the function and plasticity of brown and beige adipocytes, with a special focus on prolactin and GH actions. Most evidence points to a negative association between high prolactin levels and the thermogenic capacity of BAT, except in early development. During lactation and pregnancy, prolactin may be a contributing factor that limits unneeded thermogenesis, downregulating BAT UCP1. Furthermore, animal models of high serum prolactin have low BAT UCP1 levels and whitening of the tissue, while lack of Prlr induces beiging in WAT depots. These actions may involve hypothalamic nuclei, particularly the DMN, POA and ARN, brain centers that participate in thermogenesis. Studies on GH regulation of BAT function present some controversies. Most mouse models with GH excess or deficiency point to an inhibitory role of GH on BAT function. Even so, a stimulatory role of GH on WAT beiging has also been described, in accordance with whole-genome microarrays that demonstrate divergent response signatures of BAT and WAT genes to the loss of GH signaling. Understanding the physiology of BAT and WAT beiging may contribute to the ongoing efforts to curtail obesity.
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Affiliation(s)
- Catalina de Winne
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Florencia L Pascual
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Felicitas Lopez-Vicchi
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Luz Etcheverry-Boneo
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Luis F Mendez-Garcia
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Ana Maria Ornstein
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Isabel Maria Lacau-Mengido
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Eleonora Sorianello
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
| | - Damasia Becu-Villalobos
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad de Buenos Aires, Argentina
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3
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Ryu V, Gumerova A, Witztum R, Korkmaz F, Kannangara H, Moldavski O, Barak O, Lizneva D, Goosens KA, Stanley S, Kim SM, Yuen T, Zaidi M. An Atlas of Brain-Bone Sympathetic Neural Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.07.579382. [PMID: 38370676 PMCID: PMC10871366 DOI: 10.1101/2024.02.07.579382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
There is clear evidence that the sympathetic nervous system (SNS) mediates bone metabolism. Histological studies show abundant SNS innervation of the periosteum and bone marrow--these nerves consist of noradrenergic fibers that immunostain for tyrosine hydroxylase, dopamine beta hydroxylase, or neuropeptide Y. Nonetheless, the brain sites that send efferent SNS outflow to bone have not yet been characterized. Using pseudorabies (PRV) viral transneuronal tracing, we report, for the first time, the identification of central SNS outflow sites that innervate bone. We find that the central SNS outflow to bone originates from 87 brain nuclei, sub-nuclei and regions of six brain divisions, namely the midbrain and pons, hypothalamus, hindbrain medulla, forebrain, cerebral cortex, and thalamus. We also find that certain sites, such as the raphe magnus (RMg) of the medulla and periaqueductal gray (PAG) of the midbrain, display greater degrees of PRV152 infection, suggesting that there is considerable site-specific variation in the levels of central SNS outflow to bone. This comprehensive compendium illustrating the central coding and control of SNS efferent signals to bone should allow for a greater understanding of the neural regulation of bone metabolism, and importantly and of clinical relevance, mechanisms for central bone pain.
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Affiliation(s)
- Vitaly Ryu
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Anisa Gumerova
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ronit Witztum
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Funda Korkmaz
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Hasni Kannangara
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ofer Moldavski
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Orly Barak
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Daria Lizneva
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ki A. Goosens
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Sarah Stanley
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Se-Min Kim
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Tony Yuen
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Mone Zaidi
- Center for Translational Medicine and Pharmacology (CeTMaP), Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Medicine and of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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4
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Abstract
Brown adipose tissue (BAT) displays the unique capacity to generate heat through uncoupled oxidative phosphorylation that makes it a very attractive therapeutic target for cardiometabolic diseases. Here, we review BAT cellular metabolism, its regulation by the central nervous and endocrine systems and circulating metabolites, the plausible roles of this tissue in human thermoregulation, energy balance, and cardiometabolic disorders, and the current knowledge on its pharmacological stimulation in humans. The current definition and measurement of BAT in human studies relies almost exclusively on BAT glucose uptake from positron emission tomography with 18F-fluorodeoxiglucose, which can be dissociated from BAT thermogenic activity, as for example in insulin-resistant states. The most important energy substrate for BAT thermogenesis is its intracellular fatty acid content mobilized from sympathetic stimulation of intracellular triglyceride lipolysis. This lipolytic BAT response is intertwined with that of white adipose (WAT) and other metabolic tissues, and cannot be independently stimulated with the drugs tested thus far. BAT is an interesting and biologically plausible target that has yet to be fully and selectively activated to increase the body's thermogenic response and shift energy balance. The field of human BAT research is in need of methods able to directly, specifically, and reliably measure BAT thermogenic capacity while also tracking the related thermogenic responses in WAT and other tissues. Until this is achieved, uncertainty will remain about the role played by this fascinating tissue in human cardiometabolic diseases.
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Affiliation(s)
- André C Carpentier
- Correspondence: André C. Carpentier, MD, Division of Endocrinology, Faculty of Medicine, University of Sherbrooke, 3001, 12th Ave N, Sherbrooke, Quebec, J1H 5N4, Canada.
| | - Denis P Blondin
- Division of Neurology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | | | - Denis Richard
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, G1V 4G5, Canada
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Jiang Y, Rezai-Zadeh K, Desmoulins LD, Muenzberg H, Derbenev AV, Zsombok A. GABAergic leptin receptor-expressing neurons in the dorsomedial hypothalamus project to brown adipose tissue-related neurons in the paraventricular nucleus of mice. Auton Neurosci 2023; 245:103058. [PMID: 36538864 PMCID: PMC9899324 DOI: 10.1016/j.autneu.2022.103058] [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: 07/08/2022] [Revised: 11/14/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022]
Abstract
Brown adipose tissue (BAT) contributes to energy homeostasis via nonshivering thermogenesis. The BAT is densely innervated by the sympathetic nervous system (SNS) and activity of pre-autonomic neurons modulates the sympathetic outflow. Leptin, an adipocyte hormone, alters energy homeostasis and thermogenesis of BAT via several neuronal circuits; however, the cellular effects of leptin on interscapular BAT (iBAT)-related neurons in the hypothalamus remain to be determined. In this study, we used pseudorabies virus (PRV) to identify iBAT-related neurons in the paraventricular nucleus (PVN) of the hypothalamus and test the hypothesis that iBAT-related PVN neurons are modulated by leptin. Inoculation of iBAT with PRV in leptin receptor reporter mice (Lepr:EGFP) demonstrated that a population of iBAT-related PVN neurons expresses Lepr receptors. Our electrophysiological findings revealed that leptin application caused hyperpolarization in some of iBAT-related PVN neurons. Bath application of leptin also modulated excitatory and inhibitory neurotransmission to most of iBAT-related PVN neurons. Using channel rhodopsin assisted circuit mapping we found that GABAergic and glutamatergic Lepr-expressing neurons in the dorsomedial hypothalamus/dorsal hypothalamic area (dDMH/DHA) project to PVN neurons; however, connected iBAT-related PVN neurons receive exclusively inhibitory signals from Lepr-expressing dDMH/DHA neurons.
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Affiliation(s)
- Yanyan Jiang
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA, United States of America; Neuroscience Program, Tulane Brain Institute, Tulane University, New Orleans, LA, United States of America
| | - Kavon Rezai-Zadeh
- Central Leptin Signaling, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, United States of America
| | - Lucie D Desmoulins
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA, United States of America
| | - Heike Muenzberg
- Central Leptin Signaling, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, United States of America
| | - Andrei V Derbenev
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA, United States of America; Neuroscience Program, Tulane Brain Institute, Tulane University, New Orleans, LA, United States of America
| | - Andrea Zsombok
- Department of Physiology, School of Medicine, Tulane University, New Orleans, LA, United States of America; Neuroscience Program, Tulane Brain Institute, Tulane University, New Orleans, LA, United States of America.
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Shemery AM, Zendlo M, Kowalski J, Gorrell E, Everett S, Wagner JG, Davis AE, Koch LG, Britton SL, Mul JD, Novak CM. Reduced contextually induced muscle thermogenesis in rats with calorie restriction and lower aerobic fitness but not monogenic obesity. Temperature (Austin) 2023; 10:379-393. [PMID: 37554387 PMCID: PMC10405760 DOI: 10.1080/23328940.2023.2171669] [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: 12/01/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/29/2023] Open
Abstract
We have previously identified predator odor as a potent stimulus activating thermogenesis in skeletal muscle in rats. As this may prove relevant for energy balance and weight loss, the current study investigated whether skeletal muscle thermogenesis was altered with negative energy balance, obesity propensity seen in association with low intrinsic aerobic fitness, and monogenic obesity. First, weight loss subsequent to 3 wk of 50% calorie restriction suppressed the muscle thermogenic response to predator odor. Next, we compared rats bred based on artificial selection for intrinsic aerobic fitness - high- and low-capacity runners (HCR, LCR) - that display robust leanness and obesity propensity, respectively. Aerobically fit HCR showed enhanced predator odor-induced muscle thermogenesis relative to the less-fit LCR. This contrasted with the profound monogenic obesity displayed by rats homozygous for a loss of function mutation in Melanocortin 4 receptor (Mc4rK3a,4X/K314X rats), which showed no discernable deficit in thermogenesis. Taken together, these data imply that body size or obesity per se are not associated with deficient muscle thermogenesis. Rather, the physiological phenotype associated with polygenic obesity propensity may encompass pleiotropic mechanisms in the thermogenic pathway. Adaptive thermogenesis associated with weight loss also likely alters muscle thermogenic mechanisms.
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Affiliation(s)
- Ashley M Shemery
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Meredith Zendlo
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Jesse Kowalski
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Erin Gorrell
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Scott Everett
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Jacob G Wagner
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Ashley E Davis
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Lauren G Koch
- Department of Physiology and Pharmacology, the University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Steven L Britton
- Department of Anesthesiology, and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Joram D Mul
- Brain Plasticity Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, the Netherlands
| | - Colleen M Novak
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
- Department of Biological Sciences, Kent State University, Kent, OH, USA
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7
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Albaugh VL, He Y, Münzberg H, Morrison CD, Yu S, Berthoud HR. Regulation of body weight: Lessons learned from bariatric surgery. Mol Metab 2023; 68:101517. [PMID: 35644477 PMCID: PMC9938317 DOI: 10.1016/j.molmet.2022.101517] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 05/04/2022] [Accepted: 05/21/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bariatric or weight loss surgery is currently the most effective treatment for obesity and metabolic disease. Unlike dieting and pharmacology, its beneficial effects are sustained over decades in most patients, and mortality is among the lowest for major surgery. Because there are not nearly enough surgeons to implement bariatric surgery on a global scale, intensive research efforts have begun to identify its mechanisms of action on a molecular level in order to replace surgery with targeted behavioral or pharmacological treatments. To date, however, there is no consensus as to the critical mechanisms involved. SCOPE OF REVIEW The purpose of this non-systematic review is to evaluate the existing evidence for specific molecular and inter-organ signaling pathways that play major roles in bariatric surgery-induced weight loss and metabolic benefits, with a focus on Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), in both humans and rodents. MAJOR CONCLUSIONS Gut-brain communication and its brain targets of food intake control and energy balance regulation are complex and redundant. Although the relatively young science of bariatric surgery has generated a number of hypotheses, no clear and unique mechanism has yet emerged. It seems increasingly likely that the broad physiological and behavioral effects produced by bariatric surgery do not involve a single mechanism, but rather multiple signaling pathways. Besides a need to improve and better validate surgeries in animals, advanced techniques, including inducible, tissue-specific knockout models, and the use of humanized physiological traits will be necessary. State-of-the-art genetically-guided neural identification techniques should be used to more selectively manipulate function-specific pathways.
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Affiliation(s)
- Vance L Albaugh
- Translational and Integrative Gastrointestinal and Endocrine Research Laboratory, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Yanlin He
- Brain Glycemic and Metabolism Control Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Heike Münzberg
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Christopher D Morrison
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Sangho Yu
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA.
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8
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Speakman JR, Elmquist JK. Obesity: an evolutionary context. LIFE METABOLISM 2022; 1:10-24. [PMID: 36394061 PMCID: PMC9642988 DOI: 10.1093/lifemeta/loac002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/21/2022] [Accepted: 03/09/2022] [Indexed: 05/07/2023]
Abstract
People completely lacking body fat (lipodystrophy/lipoatrophy) and those with severe obesity both show profound metabolic and other health issues. Regulating levels of body fat somewhere between these limits would, therefore, appear to be adaptive. Two different models might be contemplated. More traditional is a set point (SP) where the levels are regulated around a fixed level. Alternatively, dual-intervention point (DIP) is a system that tolerates fairly wide variation but is activated when critically high or low levels are breached. The DIP system seems to fit our experience much better than an SP, and models suggest that it is more likely to have evolved. A DIP system may have evolved because of two contrasting selection pressures. At the lower end, we may have been selected to avoid low levels of fat as a buffer against starvation, to avoid disease-induced anorexia, and to support reproduction. At the upper end, we may have been selected to avoid excess storage because of the elevated risks of predation. This upper limit of control seems to have malfunctioned because some of us deposit large fat stores, with important negative health effects. Why has evolution not protected us against this problem? One possibility is that the protective system slowly fell apart due to random mutations after we dramatically reduced the risk of being predated during our evolutionary history. By chance, it fell apart more in some people than others, and these people are now unable to effectively manage their weight in the face of the modern food glut. To understand the evolutionary context of obesity, it is important to separate the adaptive reason for storing some fat (i.e. the lower intervention point), from the nonadaptive reason for storing lots of fat (a broken upper intervention point). The DIP model has several consequences, showing how we understand the obesity problem and what happens when we attempt to treat it.
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Affiliation(s)
- John R Speakman
- Corresponding author. John R Speakman, Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen, China. E-mail:
| | - Joel K Elmquist
- Joel K. Elmquist, Departments of Internal Medicine and Pharmacology, Center for Hypothalamic Research, University of Texas Southwestern, 5323 Harry Hines blvd., Dallas, TX 75390, USA. E-mail:
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9
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Singh U, Jiang J, Saito K, Toth BA, Dickey JE, Rodeghiero SR, Deng Y, Deng G, Xue B, Zhu Z, Zingman LV, Geerling JC, Cui H. Neuroanatomical organization and functional roles of PVN MC4R pathways in physiological and behavioral regulations. Mol Metab 2022; 55:101401. [PMID: 34823066 PMCID: PMC8689242 DOI: 10.1016/j.molmet.2021.101401] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/04/2021] [Accepted: 11/17/2021] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE The paraventricular nucleus of hypothalamus (PVN), an integrative center in the brain, orchestrates a wide range of physiological and behavioral responses. While the PVN melanocortin 4 receptor (MC4R) signaling (PVNMC4R+) is involved in feeding regulation, the neuroanatomical organization of PVNMC4R+ connectivity and its role in other physiological regulations are incompletely understood. Here we aimed to better characterize the input-output organization of PVNMC4R+ neurons and test their physiological functions beyond feeding. METHODS Using a combination of viral tools, we mapped PVNMC4R+ circuits and tested the effects of chemogenetic activation of PVNMC4R+ neurons on thermoregulation, cardiovascular control, and other behavioral responses beyond feeding. RESULTS We found that PVNMC4R+ neurons innervate many different brain regions that are known to be important not only for feeding but also for neuroendocrine and autonomic control of thermoregulation and cardiovascular function, including but not limited to the preoptic area, median eminence, parabrachial nucleus, pre-locus coeruleus, nucleus of solitary tract, ventrolateral medulla, and thoracic spinal cord. Contrary to these broad efferent projections, PVNMC4R+ neurons receive monosynaptic inputs mainly from other hypothalamic nuclei (preoptic area, arcuate and dorsomedial hypothalamic nuclei, supraoptic nucleus, and premammillary nucleus), the circumventricular organs (subfornical organ and vascular organ of lamina terminalis), the bed nucleus of stria terminalis, and the parabrachial nucleus. Consistent with their broad efferent projections, chemogenetic activation of PVNMC4R+ neurons not only suppressed feeding but also led to an apparent increase in heart rate, blood pressure, and brown adipose tissue temperature. These physiological changes accompanied acute transient hyperactivity followed by hypoactivity and resting-like behavior. CONCLUSIONS Our results elucidate the neuroanatomical organization of PVNMC4R+ circuits and shed new light on the roles of PVNMC4R+ pathways in autonomic control of thermoregulation, cardiovascular function, and biphasic behavioral activation.
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Affiliation(s)
- Uday Singh
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Jingwei Jiang
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Kenji Saito
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Brandon A Toth
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Jacob E Dickey
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Samuel R Rodeghiero
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Yue Deng
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Guorui Deng
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Baojian Xue
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, United States
| | - Zhiyong Zhu
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Leonid V Zingman
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Joel C Geerling
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA, United States; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Huxing Cui
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States; F.O.E. Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA, United States; Obesity Research and Educational Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, United States.
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10
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Niu J, Tong J, Blevins JE. Oxytocin as an Anti-obesity Treatment. Front Neurosci 2021; 15:743546. [PMID: 34720864 PMCID: PMC8549820 DOI: 10.3389/fnins.2021.743546] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/16/2021] [Indexed: 12/19/2022] Open
Abstract
Obesity is a growing health concern, as it increases risk for heart disease, hypertension, type 2 diabetes, cancer, COVID-19 related hospitalizations and mortality. However, current weight loss therapies are often associated with psychiatric or cardiovascular side effects or poor tolerability that limit their long-term use. The hypothalamic neuropeptide, oxytocin (OT), mediates a wide range of physiologic actions, which include reproductive behavior, formation of prosocial behaviors and control of body weight. We and others have shown that OT circumvents leptin resistance and elicits weight loss in diet-induced obese rodents and non-human primates by reducing both food intake and increasing energy expenditure (EE). Chronic intranasal OT also elicits promising effects on weight loss in obese humans. This review evaluates the potential use of OT as a therapeutic strategy to treat obesity in rodents, non-human primates, and humans, and identifies potential mechanisms that mediate this effect.
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Affiliation(s)
- JingJing Niu
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - Jenny Tong
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
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11
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Münzberg H, Floyd E, Chang JS. Sympathetic Innervation of White Adipose Tissue: to Beige or Not to Beige? Physiology (Bethesda) 2021; 36:246-255. [PMID: 34159808 DOI: 10.1152/physiol.00038.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Obesity research progresses in understanding neuronal circuits and adipocyte biology to regulate metabolism. However, the interface of neuro-adipocyte interaction is less studied. We summarize the current knowledge of adipose tissue innervation and interaction with adipocytes and emphasize adipocyte transitions from white to brown adipocytes and vice versa. We further highlight emerging concepts for the differential neuronal regulation of brown/beige versus white adipocyte and the interdependence of both for metabolic regulation.
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Affiliation(s)
- Heike Münzberg
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Elizabeth Floyd
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Ji Suk Chang
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
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12
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Deng Y, Deng G, Grobe JL, Cui H. Hypothalamic GPCR Signaling Pathways in Cardiometabolic Control. Front Physiol 2021; 12:691226. [PMID: 34262481 PMCID: PMC8274634 DOI: 10.3389/fphys.2021.691226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 05/26/2021] [Indexed: 01/22/2023] Open
Abstract
Obesity is commonly associated with sympathetic overdrive, which is one of the major risk factors for the development of cardiovascular diseases, such as hypertension and heart failure. Over the past few decades, there has been a growing understanding of molecular mechanisms underlying obesity development with central origin; however, the relative contribution of these molecular changes to the regulation of cardiovascular function remains vague. A variety of G-protein coupled receptors (GPCRs) and their downstream signaling pathways activated in distinct hypothalamic neurons by different metabolic hormones, neuropeptides and monoamine neurotransmitters are crucial not only for the regulation of appetite and metabolic homeostasis but also for the sympathetic control of cardiovascular function. In this review, we will highlight the main GPCRs and associated hypothalamic nuclei that are important for both metabolic homeostasis and cardiovascular function. The potential downstream molecular mediators of these GPCRs will also be discussed.
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Affiliation(s)
- Yue Deng
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Guorui Deng
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Justin L. Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI, United States
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Huxing Cui
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- FOE Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- Obesity Research and Educational Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, United States
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13
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McMillan TR, Forster MAM, Short LI, Rudecki AP, Cline DL, Gray SL. Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice. Exp Physiol 2020; 106:427-437. [PMID: 33332767 DOI: 10.1113/ep088838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 11/27/2020] [Indexed: 12/16/2022]
Abstract
NEW FINDINGS What is the central question of this study? Can chronic treatment of pituitary adenylate cyclase-activating polypeptide (PACAP) deficient mice with the melanocortin agonist melanotan II during cold acclimation rescue the impaired thermogenic capacity previously observed in PACAP deficient mice? What is the main finding and its importance? Using a genetic model of PACAP deficiency, this study provides evidence that PACAP acts upstream of the melanocortin system in regulating sympathetic nerve activity to brown adipose tissue in mice. ABSTRACT Impaired adipose tissue function in obesity, including reduced thermogenic potential, has detrimental consequences for metabolic health. Hormonal regulation of adaptive thermogenesis is being explored as a potential therapeutic target for human obesity. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide expressed in nuclei of the hypothalamus known to regulate energy expenditure, and functional studies reveal a role for PACAP in the central regulation of thermogenesis, although mechanisms are not well understood. We hypothesized that PACAP acts upstream of the melanocortin system to regulate sympathetic nerve activity to stimulate thermogenesis. To assess this, female PACAP-/- and PACAP+/+ mice were given daily peripheral injections of a melanocortin receptor agonist, melanotan II (MTII), for 3 weeks during cold acclimation, and the effect of MTII on thermogenic capacity and adipose tissue remodelling was examined by physiological and histological analyses. MTII partially rescued the impaired thermogenic capacity in PACAP-/- mice as compared to PACAP+/+ mice as determined by measuring noradrenaline-induced metabolic rate. In addition, MTII treatment during cold acclimation corrected the previously identified deficit in lipid utilization in response to adrenergic stimulation in PACAP-/- null mice, suggesting impaired lipid mobilization may contribute to the impaired thermogenic capacity of PACAP-/- mice. Results presented here provide physiological evidence to suggest that PACAP acts upstream of melanocortin receptors to facilitate sympathetically induced mechanisms of adaptive thermogenesis in response to cold acclimation.
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Affiliation(s)
- Thecla Rae McMillan
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Maeghan A M Forster
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Landon I Short
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Alexander P Rudecki
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Daemon L Cline
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Sarah L Gray
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
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Abstract
Since the discovery of functionally competent, energy-consuming brown adipose tissue (BAT) in adult humans, much effort has been devoted to exploring this tissue as a means for increasing energy expenditure to counteract obesity. However, despite promising effects on metabolic rate and insulin sensitivity, no convincing evidence for weight-loss effects of cold-activated human BAT exists to date. Indeed, increasing energy expenditure would naturally induce compensatory feedback mechanisms to defend body weight. Interestingly, BAT is regulated by multiple interactions with the hypothalamus from regions overlapping with centers for feeding behavior and metabolic control. Therefore, in the further exploration of BAT as a potential source of novel drug targets, we discuss the hypothalamic orchestration of BAT activity and the relatively unexplored BAT feedback mechanisms on neuronal regulation. With a holistic view on hypothalamic-BAT interactions, we aim to raise ideas and provide a new perspective on this circuit and highlight its clinical relevance.
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Affiliation(s)
- Jo B Henningsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark;
| | - Camilla Scheele
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark;
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15
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Holland J, Sorrell J, Yates E, Smith K, Arbabi S, Arnold M, Rivir M, Morano R, Chen J, Zhang X, Dimarchi R, Woods SC, Sanchez-Gurmaches J, Wohleb E, Perez-Tilve D. A Brain-Melanocortin-Vagus Axis Mediates Adipose Tissue Expansion Independently of Energy Intake. Cell Rep 2020; 27:2399-2410.e6. [PMID: 31116984 PMCID: PMC6550338 DOI: 10.1016/j.celrep.2019.04.089] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/18/2019] [Accepted: 04/18/2019] [Indexed: 02/07/2023] Open
Abstract
The melanocortin system is a brain circuit that influences energy balance by regulating energy intake and expenditure. In addition, the brain-melanocortin system controls adipose tissue metabolism to optimize fuel mobilization and storage. Specifically, increased brain-melanocortin signaling or negative energy balance promotes lipid mobilization by increasing sympathetic nervous system input to adipose tissue. In contrast, calorie-independent mechanisms favoring energy storage are less understood. Here, we demonstrate that reduction of brain-melanocortin signaling actively promotes fat mass gain by activating the lipogenic program and adipocyte and endothelial cell proliferation in white fat depots independently of caloric intake via efferent nerve fibers conveyed by the common hepatic branch of the vagus nerve. Those vagally regulated obesogenic signals also contribute to the fat mass gain following chronic high-fat diet feeding. These data reveal a physiological mechanism whereby the brain controls energy stores that may contribute to increased susceptibility to obesity. Brain-melanocortin signaling controls fat mass indirectly by regulating energy balance and by direct control of lipid mobilization from adipose tissue via sympathetic nervous system activity. Holland et al. show that reduced brain-melanocortin signaling promotes white adipose tissue expansion via signals conveyed by efferent innervation of the vagus nerve.
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Affiliation(s)
- Jenna Holland
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joyce Sorrell
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Emily Yates
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Kathleen Smith
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Shahriar Arbabi
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | - Marita Rivir
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Rachel Morano
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jenny Chen
- Genomics, Epigenomics and Sequencing Core, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Xiang Zhang
- Genomics, Epigenomics and Sequencing Core, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Richard Dimarchi
- Novo Nordisk Research Center Indianapolis, IN, USA; Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Stephen C Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joan Sanchez-Gurmaches
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Division of Endocrinology and Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH, USA
| | - Eric Wohleb
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Diego Perez-Tilve
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Seoane-Collazo P, Martínez-Sánchez N, Milbank E, Contreras C. Incendiary Leptin. Nutrients 2020; 12:nu12020472. [PMID: 32069871 PMCID: PMC7071158 DOI: 10.3390/nu12020472] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/06/2020] [Accepted: 02/08/2020] [Indexed: 02/08/2023] Open
Abstract
Leptin is a hormone released by adipose tissue that plays a key role in the control of energy homeostasis through its binding to leptin receptors (LepR), mainly expressed in the hypothalamus. Most scientific evidence points to leptin’s satiating effect being due to its dual capacity to promote the expression of anorexigenic neuropeptides and to reduce orexigenic expression in the hypothalamus. However, it has also been demonstrated that leptin can stimulate (i) thermogenesis in brown adipose tissue (BAT) and (ii) the browning of white adipose tissue (WAT). Since the demonstration of the importance of BAT in humans 10 years ago, its study has aroused great interest, mainly in the improvement of obesity-associated metabolic disorders through the induction of thermogenesis. Consequently, several strategies targeting BAT activation (mainly in rodent models) have demonstrated great potential to improve hyperlipidemias, hepatic steatosis, insulin resistance and weight gain, leading to an overall healthier metabolic profile. Here, we review the potential therapeutic ability of leptin to correct obesity and other metabolic disorders, not only through its satiating effect, but by also utilizing its thermogenic properties.
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Affiliation(s)
- Patricia Seoane-Collazo
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782 Santiago de Compostela, Spain;
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706 Santiago de Compostela, Spain
- Correspondence: (P.S.-C.); (N.M.-S.); (C.C.); Tel.: +81-298-533-301 (P.S.-C.); +34-913-941-650 (N.M.-S.); +44-01865285890 (C.C.)
| | - Noelia Martínez-Sánchez
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
- Correspondence: (P.S.-C.); (N.M.-S.); (C.C.); Tel.: +81-298-533-301 (P.S.-C.); +34-913-941-650 (N.M.-S.); +44-01865285890 (C.C.)
| | - Edward Milbank
- CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782 Santiago de Compostela, Spain;
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706 Santiago de Compostela, Spain
| | - Cristina Contreras
- Department of Physiology, Pharmacy School, Complutense University of Madrid, 28040 Madrid, Spain
- Correspondence: (P.S.-C.); (N.M.-S.); (C.C.); Tel.: +81-298-533-301 (P.S.-C.); +34-913-941-650 (N.M.-S.); +44-01865285890 (C.C.)
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Yu H, Chhabra KH, Thompson Z, Jones GL, Kiran S, Shangguan G, Low MJ. Hypothalamic POMC deficiency increases circulating adiponectin despite obesity. Mol Metab 2020; 35:100957. [PMID: 32244188 PMCID: PMC7082555 DOI: 10.1016/j.molmet.2020.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 02/06/2023] Open
Abstract
Objective The steep rise in the prevalence of obesity and its related metabolic syndrome have become a major worldwide health concerns. Melanocortin peptides from hypothalamic arcuate nucleus (Arc) POMC neurons induce satiety to limit food intake. Consequently, Arc Pomc-deficient mice (ArcPomc−/−) exhibit hyperphagia and obesity. Previous studies demonstrated that the circulating levels of adiponectin, a protein abundantly produced and secreted by fat cells, negatively correlate with obesity in both rodents and humans. However, we found that ArcPomc−/− mice have increased circulating adiponectin levels despite obesity. Therefore, we investigated the physiological function and underlying mechanisms of hypothalamic POMC in regulating systemic adiponectin levels. Methods Circulating adiponectin was measured in obese ArcPomc−/− mice at ages 4–52 weeks. To determine whether increased adiponectin was a direct result of ArcPomc deficiency or a secondary effect of obesity, we examined plasma adiponectin levels in calorie-restricted mice with or without a history of obesity and in ArcPomc−/− mice before and after genetic restoration of Pomc expression in the hypothalamus. To delineate the mechanisms causing increased adiponectin in ArcPomc−/− mice, we determined sympathetic outflow to adipose tissue by assessing epinephrine, norepinephrine, and tyrosine hydroxylase protein levels and measured the circulating adiponectin in the mice after acute norepinephrine or propranolol treatments. In addition, adiponectin mRNA and protein levels were measured in discrete adipose tissue depots to ascertain which fat depots contributed the most to the high level of adiponectin in the ArcPomc−/− mice. Finally, we generated compound Adiopoq−/−:ArcPomc−/− mice and compared their growth, body composition, and glucose homeostasis to the individual knockout mouse strains and their wild-type controls. Results Obese ArcPomc−/− female mice had unexpectedly increased plasma adiponectin compared to wild-type siblings at all ages greater than 8 weeks. Despite chronic calorie restriction to achieve normal body weights, higher adiponectin levels persisted in the ArcPomc−/− female mice. Genetic restoration of Pomc expression in the Arc or acute treatment of the ArcPomc−/− female mice with melanotan II reduced adiponectin levels to control littermate values. The ArcPomc−/− mice had defective thermogenesis and decreased epinephrine, norepinephrine, and tyrosine hydroxylase protein levels in their fat pads, indicating reduced sympathetic outflow to adipose tissue. Injections of norepinephrine into the ArcPomc−/− female mice reduced circulating adiponectin levels, whereas injections of propranolol significantly increased adiponectin levels. Despite the beneficial effects of adiponectin on metabolism, the deletion of adiponectin alleles in the ArcPomc−/− mice did not exacerbate their metabolic abnormalities. Conclusion In summary, to the best of our knowledge, this study provides the first evidence that despite obesity, the ArcPomc−/− mouse model has high circulating adiponectin levels, which demonstrated that increased fat mass is not necessarily correlated with hypoadiponectinemia. Our investigation also found a previously unknown physiological pathway connecting POMC neurons via the sympathetic nervous system to circulating adiponectin, thereby shedding light on the biological regulation of adiponectin. Obese female hypothalamic-specific Pomc-deficient mice have unexpectedly elevated circulating adiponectin. Restoration of Pomc expression in the hypothalamus reduces plasma adiponectin. Low sympathetic output to subcutaneous fat depots in the Pomc-deficient mice contributes to high adiponectin levels. Deletion of adiponectin in hypothalamic-specific Pomc-deficient mice does not alter their metabolic phenotype.
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Affiliation(s)
- Hui Yu
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA.
| | - Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Zoe Thompson
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Graham L Jones
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Sylee Kiran
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; School of Literature, Science, and Arts, University of Michigan, Ann Arbor, MI, USA
| | - Gary Shangguan
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
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18
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Straat ME, Schinkelshoek MS, Fronczek R, Lammers GJ, Rensen PCN, Boon MR. Role of Brown Adipose Tissue in Adiposity Associated With Narcolepsy Type 1. Front Endocrinol (Lausanne) 2020; 11:145. [PMID: 32373062 PMCID: PMC7176868 DOI: 10.3389/fendo.2020.00145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 03/02/2020] [Indexed: 11/23/2022] Open
Abstract
Narcolepsy type 1 is a neurological sleep-wake disorder caused by the destruction of orexin (hypocretin)-producing neurons. These neurons are particularly located in the lateral hypothalamus and have widespread projections throughout the brain, where they are involved, e.g., in the regulation of the sleep-wake cycle and appetite. Interestingly, a higher prevalence of obesity has been reported in patients with narcolepsy type 1 compared to healthy controls, despite a normal to decreased food intake and comparable physical activity. This suggests the involvement of tissues implicated in total energy expenditure, including skeletal muscle, liver, white adipose tissue (WAT), and brown adipose tissue (BAT). Recent evidence from pre-clinical studies with orexin knock-out mice demonstrates a crucial role for the orexin system in the functionality of brown adipose tissue (BAT), probably through multiple pathways. Since BAT is a highly metabolically active organ that combusts fatty acids and glucose toward heat, thereby contributing to energy metabolism, this raises the question of whether BAT plays a role in the development of obesity and related metabolic diseases in narcolepsy type 1. BAT is densely innervated by the sympathetic nervous system that activates BAT, for instance, following cold exposure. The sympathetic outflow toward BAT is mainly mediated by the dorsomedial, ventromedial, arcuate, and paraventricular nuclei in the hypothalamus. This review focuses on the current knowledge on the role of the orexin system in the control of energy balance, with specific focus on BAT metabolism and adiposity in both preclinical and clinical studies.
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Affiliation(s)
- Maaike E. Straat
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, Netherlands
- *Correspondence: Maaike E. Straat
| | - Mink S. Schinkelshoek
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
- Sleep Wake Centre SEIN, Heemstede, Netherlands
| | - Rolf Fronczek
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
- Sleep Wake Centre SEIN, Heemstede, Netherlands
| | - Gerrit Jan Lammers
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
- Sleep Wake Centre SEIN, Heemstede, Netherlands
| | - Patrick C. N. Rensen
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Mariëtte R. Boon
- Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, Netherlands
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Bernasochi GB, Bell JR, Simpson ER, Delbridge LM, Boon WC. Impact of Estrogens on the Regulation of White, Beige, and Brown Adipose Tissue Depots. Compr Physiol 2019; 9:457-475. [DOI: 10.1002/cphy.c180009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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20
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Cao Q, Jing J, Cui X, Shi H, Xue B. Sympathetic nerve innervation is required for beigeing in white fat. Physiol Rep 2019; 7:e14031. [PMID: 30873754 PMCID: PMC6418318 DOI: 10.14814/phy2.14031] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 11/24/2022] Open
Abstract
It is increasingly recognized that activation of beige adipocyte thermogenesis by pharmacological or genetic approaches increases energy expenditure and alleviates obesity. Sympathetic nervous system (SNS) directly innervating brown adipose tissue (BAT) and white adipose tissue (WAT) plays a key role in promoting nonshivering thermogenesis. However, direct evidence that supports the importance of SNS innervation for beige adipocyte formation is still lacking, and the significance of beige adipocyte thermogenesis in protection of body temperature during cold challenge is not clear. Here we tested the necessity of SNS innervation into WAT for beige adipocyte formation in mice with defective brown fat thermogenesis via interscapular BAT (iBAT) SNS denervation. SNS denervation was achieved by microinjection of 6-hydroxydopamine (6-OHDA), a selective neurotoxin to SNS nerves, into iBAT, inguinal WAT (iWAT), or both. The partial chemical denervation of iBAT SNS down-regulated UCP-1 protein expression in iBAT demonstrated by immunoblotting and immunohistochemical measurements. This was associated with an up-regulation of UCP1 protein expression and enhanced formation of beige cells in iWAT of mice with iBAT SNS denervation. In contrast, the chemical denervation of iWAT SNS completely abolished the upregulated UCP-1 protein and beige cell formation in iWAT of mice with iBAT SNS denervation. Our data demonstrate that SNS innervation in WAT is required for beige cell formation during cold-induced thermogenesis. We conclude that there exists a coordinated thermoregulation for BAT and WAT thermogenesis via a functional cross talk between BAT and WAT SNS.
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Affiliation(s)
- Qiang Cao
- School of BiologyGeorgia State UniversityAtlantaGeorgia
| | - Jia Jing
- School of BiologyGeorgia State UniversityAtlantaGeorgia
| | - Xin Cui
- School of BiologyGeorgia State UniversityAtlantaGeorgia
| | - Hang Shi
- School of BiologyGeorgia State UniversityAtlantaGeorgia
| | - Bingzhong Xue
- School of BiologyGeorgia State UniversityAtlantaGeorgia
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Pepper I, Vinik A, Lattanzio F, McPheat W, Dobrian A. Countering the Modern Metabolic Disease Rampage With Ancestral Endocannabinoid System Alignment. Front Endocrinol (Lausanne) 2019; 10:311. [PMID: 31156558 PMCID: PMC6533883 DOI: 10.3389/fendo.2019.00311] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/30/2019] [Indexed: 12/18/2022] Open
Abstract
When primitive vertebrates evolved from ancestral members of the animal kingdom and acquired complex locomotive and neurological toolsets, a constant supply of energy became necessary for their continued survival. To help fulfill this need, the endocannabinoid (eCB) system transformed drastically with the addition of the cannabinoid-1 receptor (CB1R) to its gene repertoire. This established an eCB/CB1R signaling mechanism responsible for governing the whole organism's energy balance, with its activation triggering a shift toward energy intake and storage in the brain and the peripheral organs (i.e., liver and adipose). Although this function was of primal importance for humans during their pre-historic existence as hunter-gatherers, it became expendable following the successive lifestyle shifts of the Agricultural and Industrial Revolutions. Modernization of the world has further increased food availability and decreased energy expenditure, thus shifting the eCB/CB1R system into a state of hyperactive deregulated signaling that contributes to the 21st century metabolic disease pandemic. Studies from the literature supporting this perspective come from a variety of disciplines, including biochemistry, human medicine, evolutionary/comparative biology, anthropology, and developmental biology. Consideration of both biological and cultural evolution justifies the design of improved pharmacological treatments for obesity and Type 2 diabetes (T2D) that focus on peripheral CB1R antagonism. Blockade of peripheral CB1Rs, which universally promote energy conservation across the vertebrate lineage, represents an evolutionary medicine strategy for clinical management of present-day metabolic disorders.
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Affiliation(s)
- Ian Pepper
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, United States
- *Correspondence: Ian Pepper
| | - Aaron Vinik
- Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Frank Lattanzio
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, United States
| | - William McPheat
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Anca Dobrian
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, United States
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22
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Zhou L, Xiao X, Zhang Q, Zheng J, Li M, Deng M. A Possible Mechanism: Genistein Improves Metabolism and Induces White Fat Browning Through Modulating Hypothalamic Expression of Ucn3, Depp, and Stc1. Front Endocrinol (Lausanne) 2019; 10:478. [PMID: 31379744 PMCID: PMC6646519 DOI: 10.3389/fendo.2019.00478] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 07/02/2019] [Indexed: 12/27/2022] Open
Abstract
Bioactive food components have gained growing attention in recent years. Multiple studies demonstrated that genistein had beneficial effects on metabolism. However, the exact mechanism by which genistein improves metabolism remains unclear, especially the central regulation. This study was designed to evaluate whether addition of genistein to the high-fat diet could counter metabolic disorders and whether these alterations were associated with gene expression in hypothalamus. C57BL/6 mice were fed either a high-fat diet (HF), high-fat diet with genistein (0.25 g/kg diet) (HFG) or a normal control diet (CON) for 8 weeks. Body weight was assessed during the study. After 8-week intervention, content of inguinal subcutaneous adipose tissue (SAT), perirenal visceral adipose tissue (VAT) and brown adipose tissue (BAT) were weighed. Glucose tolerance test, the serum levels of insulin and lipid were assessed. The mRNA of browning marker was detected in the white fat. The hypothalamus was collected for whole transcriptome sequencing and reverse transcription quantitative PCR validation. The results demonstrated that mice fed HFG diet had lower body weight and SAT mass, decrease levels of low-density lipoprotein cholesterol and free fatty acids, higher browning marker of Ucp1 and Cidea in WAT and an improvement in glucose tolerance and insulin sensitivity compared with those in HF group. Transcriptome sequencing showed that there were three differentially expressed genes in hypothalamus among the three groups, including Ucn3, Depp, and Stc1, which were significantly correlated with the browning markers in WAT and insulin sensitivity. Thus, regulating gene expressions in hypothalamus is a potential mechanism for genistein improving metabolism and inducing WAT browning, which may provide a novel target for the precaution and treatment of T2DM.
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23
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Derghal A, Djelloul M, Azzarelli M, Degonon S, Tourniaire F, Landrier JF, Mounien L. MicroRNAs are involved in the hypothalamic leptin sensitivity. Epigenetics 2018; 13:1127-1140. [PMID: 30395773 DOI: 10.1080/15592294.2018.1543507] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The central nervous system monitors modifications in metabolic parameters or hormone levels (leptin) and elicits adaptive responses such as food intake and glucose homeostasis regulation. Particularly, within the hypothalamus, pro-opiomelanocortin (POMC) neurons are crucial regulators of energy balance. Consistent with a pivotal role of the melanocortin system in the control of energy homeostasis, disruption of the Pomc gene causes hyperphagia and obesity. Pomc gene expression is tightly controlled by different mechanisms. Interestingly, recent studies pointed to a key role for micro ribonucleic acid (miRNAs) in the regulation of gene expression. However, the role of miRNAs in the leptin sensitivity in hypothalamic melanocortin system has never been assessed. We developed a transgenic mouse model (PDKO) with a partial deletion of the miRNA processing enzyme DICER specifically in POMC neurons. PDKO mice exhibited a normal body weight but a decrease of food intake. Interestingly, PDKO mice had decreased metabolic rate by reduction of VO2 consumption and CO2 production which could explain that PDKO mice have normal weight while eating less. Interestingly, we observed an increase of leptin sensitivity in the POMC neurons of PDKO mice which could explain the decrease of food intake in this model. We also observed an increase in the expression of genes involved in the function of brown adipose tissue that is in polysynaptic contact with the POMC neurons. In summary, these results support the hypothesis that Dicer-derived miRNAs may be involved in the effect of leptin on POMC neurons activity.
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Affiliation(s)
- Adel Derghal
- a Aix Marseille Univ, INSERM, INRA, C2VN , Marseille , France
| | - Mehdi Djelloul
- b Department of Cell and Molecular Biology , Karolinska Institute , Stockholm , Sweden
| | | | | | - Franck Tourniaire
- a Aix Marseille Univ, INSERM, INRA, C2VN , Marseille , France.,c Faculté de Médecine de la Timone , CriBioM, Criblage Biologique Marseille , Marseille , France
| | - Jean-François Landrier
- a Aix Marseille Univ, INSERM, INRA, C2VN , Marseille , France.,c Faculté de Médecine de la Timone , CriBioM, Criblage Biologique Marseille , Marseille , France
| | - Lourdes Mounien
- a Aix Marseille Univ, INSERM, INRA, C2VN , Marseille , France
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24
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Liu J, Lin L. Small molecules for fat combustion: targeting thermosensory and satiety signals in the central nervous system. Drug Discov Today 2018; 24:300-306. [PMID: 30248402 DOI: 10.1016/j.drudis.2018.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/06/2018] [Accepted: 09/18/2018] [Indexed: 12/21/2022]
Abstract
Brown adipose tissue (BAT) dissipates fatty acids as heat to maintain body temperature in cold environments. The existence of BAT and beige cells in human adults supplies a promising weight-reduction therapy. The central thermogenic regulation descends through an excitatory neural pathway from the hypothalamus, medullar and spine towards BAT. This sympathoexcitatory thermogenic circuit is controlled by GABAergic (γ-aminobutyric acid) signaling from the thermoregulatory center in the preoptic area and the satiety center in the ventromedial nucleus of the hypothalamus. This review summarizes recent research progresses in thermogenic regulators targeting thermosensory and satiety signals in the central nervous system, and speculates on their potential as antiobesity agents.
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Affiliation(s)
- Jingxin Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macau 999078, China
| | - Ligen Lin
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macau 999078, China.
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25
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Carnagarin R, Matthews VB, Herat LY, Ho JK, Schlaich MP. Autonomic Regulation of Glucose Homeostasis: a Specific Role for Sympathetic Nervous System Activation. Curr Diab Rep 2018; 18:107. [PMID: 30232652 DOI: 10.1007/s11892-018-1069-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Cardiometabolic disorders such as obesity, metabolic syndrome and diabetes are increasingly common and associated with adverse cardiovascular outcomes. The mechanisms driving these developments are incompletely understood but likely to include autonomic dysregulation. The latest evidence for such a role is briefly reviewed here. RECENT FINDINGS Recent findings highlight the relevance of autonomic regulation in glucose metabolism and identify sympathetic activation, in concert with parasympathetic withdrawal, as a major contributor to the development of metabolic disorders and an important mediator of the associated adverse cardiovascular consequences. Methods targeting sympathetic overactivity using pharmacological and device-based approaches are available and appear as logical additional approaches to curb the burden of metabolic disorders and alleviate the associated morbidity from cardiovascular causes. While the available data are encouraging, the role of therapeutic inhibition of sympathetic overdrive in the prevention of the metabolic disorders and the associated adverse outcomes requires adequate testing in properly sized randomised controlled trials.
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Affiliation(s)
- Revathy Carnagarin
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Vance B Matthews
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Lakshini Y Herat
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Jan K Ho
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Markus P Schlaich
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia.
- Departments of Cardiology and Nephrology, Royal Perth Hospital, Perth, Australia.
- Neurovascular Hypertension & Kidney Disease Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia.
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26
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Harris RBS. Denervation as a tool for testing sympathetic control of white adipose tissue. Physiol Behav 2018; 190:3-10. [PMID: 28694155 PMCID: PMC5758439 DOI: 10.1016/j.physbeh.2017.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 10/19/2022]
Abstract
This review summarizes the evidence derived from studies utilizing denervation procedures to demonstrate sympathetic control of white adipose tissue metabolism and body fat mass. A majority of the work demonstrating neural control of white fat was performed in the Bartness laboratory with Siberian hamsters as the predominant experimental model. These animals experience dramatic changes in body fat mass in response to changes in photoperiod, however, the mechanisms identified in hamsters have been reproduced or further elucidated by experiments with other animal models. Evidence for the role of sympathetic innervation contributing to the control of white adipocyte lipolysis and preadipocyte proliferation is summarized. In addition, evidence from denervation experiments for neural communication between different white fat depots as well as for a feedback control loop between sensory afferents from individual fat depots and sympathetic efferents to the same or distant white fat depots is discussed.
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Affiliation(s)
- Ruth B S Harris
- Medical College of Georgia, Augusta University, Augusta, GA 30912, United States.
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27
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Kravchychyn A, Campos R, Corgosinho F, Masquio D, Vicente S, Ferreira Y, Silva P, Ganen A, Oyama L, Tock L, de Mello M, Tufik S, Dâmaso A. The Long-Term Impact of High Levels of Alpha-Melanocyte-Stimulating Hormone in Energy Balance Among Obese Adolescents. ANNALS OF NUTRITION AND METABOLISM 2018; 72:279-286. [DOI: 10.1159/000488005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 02/25/2018] [Indexed: 12/18/2022]
Abstract
Background: Deregulation of orexigenic and anorexigenic pathways occurs among adolescents with obesity. Alpha-melanocyte-stimulating hormone (α-MSH) is a key catabolic mediator of energy homeostasis and an important anorexigenic neuropeptide in the control of energy balance and thermogenesis. However, it was not well explored if α-MSH can modulate long-term weight loss therapy responses in a dependent manner according to its concentration. Our hypothesis is that a high α-MSH concentration at baseline promotes better modulation of anorexigenic/orexigenic pathways in obese adolescents. Methods: One hundred ten post-pubertal obese adolescents (body mass index >95th percentile) were submitted to 1 year of interdisciplinary therapy (clinical, nutritional, psychological, physical exercise, and physiotherapy support). Body composition and plasma levels of α-MSH, neuropeptide Y (NPY), melanin-concentrating hormone, and agouti-related peptide (AgRP) were measured before and after therapy. The volunteers were grouped on the basis of Tertiles of α-MSH concentration: Low (<0.75 ng/mL), Medium (≤0.76 to ≥1.57 ng/mL), and High (>1.57 ng/mL). Significance was set as p < 0.05. Results: The treatment promoted a significant improvement in body adiposity and fat free mass for all groups. It is important to note that only in the high α-MSH group, a significant increase of the α-MSH/NPY ratio and decrease NPY/AgRP ratio post treatment were observed. Conclusion: The high α-MSH concentration promotes better modulation of anorexigenic/orexigenic pathways in obese adolescents following long-term weight loss therapy and this is important in clinical practice.
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28
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Morselli LL, Claflin KE, Cui H, Grobe JL. Control of Energy Expenditure by AgRP Neurons of the Arcuate Nucleus: Neurocircuitry, Signaling Pathways, and Angiotensin. Curr Hypertens Rep 2018; 20:25. [PMID: 29556733 DOI: 10.1007/s11906-018-0824-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW Here, we review the current understanding of the functional neuroanatomy of neurons expressing Agouti-related peptide (AgRP) and the angiotensin 1A receptor (AT1A) within the arcuate nucleus (ARC) in the control of energy balance. RECENT FINDINGS The development and maintenance of obesity involves suppression of resting metabolic rate (RMR). RMR control is integrated via AgRP and proopiomelanocortin neurons within the ARC. Their projections to other hypothalamic and extrahypothalamic nuclei contribute to RMR control, though relatively little is known about the contributions of individual projections and the neurotransmitters involved. Recent studies highlight a role for AT1A, localized to AgRP neurons, but the specific function of AT1A within these cells remains unclear. AT1A functions within AgRP neurons to control RMR, but additional work is required to clarify its role within subpopulations of AgRP neurons projecting to distinct second-order nuclei, and the molecular mediators of its signaling within these cells.
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Affiliation(s)
- Lisa L Morselli
- Department of Pharmacology, University of Iowa, 51 Newton Rd., 2-307 BSB, Iowa City, IA, 52242, USA.,Department of Internal Medicine, Division of Endocrinology, University of Iowa, Iowa City, IA, 52242, USA
| | - Kristin E Claflin
- Department of Pharmacology, University of Iowa, 51 Newton Rd., 2-307 BSB, Iowa City, IA, 52242, USA
| | - Huxing Cui
- Department of Pharmacology, University of Iowa, 51 Newton Rd., 2-307 BSB, Iowa City, IA, 52242, USA.,Center for Hypertension Research, University of Iowa, Iowa City, IA, 52242, USA.,Obesity Research & Education Initiative, University of Iowa, Iowa City, IA, 52242, USA.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, 52242, USA.,Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA.,Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA, 52242, USA
| | - Justin L Grobe
- Department of Pharmacology, University of Iowa, 51 Newton Rd., 2-307 BSB, Iowa City, IA, 52242, USA. .,Center for Hypertension Research, University of Iowa, Iowa City, IA, 52242, USA. .,Obesity Research & Education Initiative, University of Iowa, Iowa City, IA, 52242, USA. .,Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, 52242, USA. .,Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA. .,Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA, 52242, USA.
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29
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Fuller-Jackson JP, Clarke IJ, Rao A, Henry BA. Exercise counteracts the homeostatic decrease in thermogenesis caused by caloric restriction in sheep. FASEB J 2018; 32:3859-3869. [PMID: 29455575 DOI: 10.1096/fj.201701504r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Caloric restriction causes a homeostatic reduction in thermogenesis. We aimed to determine whether exercise could counteract this. We studied four groups of normal-weight ewes ( n = 5), including control sedentary fed ad libitum, exercise fed ad libitum (30 min/d, 5 d/wk), diet-restricted (70% of ad libitum food intake), and combined diet and exercise. Temperature probes implanted in sternal and retroperitoneal adipose tissue and skeletal muscle measured thermogenesis. After the 4-wk intervention, hypothalami were collected for in situ hybridization, and fat and muscle biopsies were collected for real-time PCR and Western blotting. Combined diet and exercise reduced adiposity ( P < 0.05). Caloric restriction alone reduced overnight temperatures in sternal and retroperitoneal fat ( P < 0.05), which was counteracted by exercise ( P < 0.05). Exercise did not induce expression of cellular markers of browning in adipose tissue. There was no effect of diet or exercise on skeletal muscle thermogenesis. Combined diet and exercise increased the expression of neuropeptide Y and agouti-related protein in the hypothalamic arcuate nucleus ( P < 0.05), consistent with reduced adiposity. Gene expressions of key hypothalamic appetite-regulating peptides were not associated with altered thermogenesis. We demonstrate that exercise counteracts the inhibitory effect of caloric restriction to restore thermogenesis in adipose tissue of sheep.-Fuller-Jackson, J.-P., Clarke, I. J., Rao, A., Henry, B. A. Exercise counteracts the homeostatic decrease in thermogenesis caused by caloric restriction in sheep.
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Affiliation(s)
- John-Paul Fuller-Jackson
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Iain J Clarke
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Alexandra Rao
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Belinda A Henry
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
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Abstract
Interactions between the brain and distinct adipose depots have a key role in maintaining energy balance, thereby promoting survival in response to metabolic challenges such as cold exposure and starvation. Recently, there has been renewed interest in the specific central neuronal circuits that regulate adipose depots. Here, we review anatomical, genetic and pharmacological studies on the neural regulation of adipose function, including lipolysis, non-shivering thermogenesis, browning and leptin secretion. In particular, we emphasize the role of leptin-sensitive neurons and the sympathetic nervous system in modulating the activity of brown, white and beige adipose tissues. We provide an overview of advances in the understanding of the heterogeneity of the brain regulation of adipose tissues and offer a perspective on the challenges and paradoxes that the community is facing regarding the actions of leptin on this system.
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Affiliation(s)
- Alexandre Caron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Syann Lee
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K. Elmquist
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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31
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Nguyen NLT, Xue B, Bartness TJ. Sensory denervation of inguinal white fat modifies sympathetic outflow to white and brown fat in Siberian hamsters. Physiol Behav 2018; 190:28-33. [PMID: 29447836 DOI: 10.1016/j.physbeh.2018.02.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 02/10/2018] [Accepted: 02/10/2018] [Indexed: 10/18/2022]
Abstract
White adipose tissue (WAT) and brown adipose tissue (BAT) have sympathetic nervous system (SNS) and sensory innervations. Previous studies from our laboratory revealed central neuroanatomical evidence of WAT sensory and BAT SNS crosstalk with double labeling of inguinal WAT (IWAT) sensory and interscapular BAT (IBAT) SNS neurons. We previously demonstrated that WAT lipolysis increases IBAT temperature, but this effect is absent when IWAT afferents are surgically denervated, which severs both sensory and SNS nerves. It is possible that WAT sensory feedback can regulate SNS drive to itself and other WAT and BAT depots, and thus contribute to the existence of differential SNS outflow to fat during different energy challenges. Here we selectively denervated IWAT sensory nerves in Siberian hamsters using capsaicin and measured norepinephrine turnover (NETO) i.e., SNS drive to WAT and BAT depots, IBAT uncoupling protein 1 (UCP1) expression, body mass, fat mass, blood glucose, and food consumed after a 24-h cold exposure. IWAT sensory denervation decreased both IWAT and IBAT NETO and IBAT UCP1 expression. IWAT sensory denervation, however, increased mesenteric WAT (MWAT) NETO after the 24-h cold exposure and did not modify epididymal WAT (EWAT) and retroperitoneal WAT (RWAT) NETO compared with respective controls. Body mass, fat mass, blood glucose, and food consumed were unchanged across groups. RWAT and EWAT mass decreased in capsaicin-injected hamsters, but did not in the vehicle hamsters. These results functionally demonstrate the existence of IWAT sensory and IBAT SNS crosstalk and that a disruption in this sensory-SNS feedback mechanism modifies SNS drive to IWAT, IBAT, and MWAT, but not EWAT and RWAT.
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Affiliation(s)
- Ngoc Ly T Nguyen
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; Center for Obesity Reversal, Georgia State University, Atlanta, GA 30303, USA
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; Center for Obesity Reversal, Georgia State University, Atlanta, GA 30303, USA.
| | - Timothy J Bartness
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; Center for Obesity Reversal, Georgia State University, Atlanta, GA 30303, USA
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32
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Morrison SF. Efferent neural pathways for the control of brown adipose tissue thermogenesis and shivering. HANDBOOK OF CLINICAL NEUROLOGY 2018; 156:281-303. [PMID: 30454595 DOI: 10.1016/b978-0-444-63912-7.00017-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The fundamental central neural circuits for thermoregulation orchestrate behavioral and autonomic repertoires that maintain body core temperature during thermal challenges that arise from either the ambient or the internal environment. This review summarizes our understanding of the neural pathways within the fundamental thermoregulatory reflex circuitry that comprise the efferent (i.e., beyond thermosensory) control of brown adipose tissue (BAT) and shivering thermogenesis: the motor neuron systems consisting of the BAT sympathetic preganglionic neurons and BAT sympathetic ganglion cells, and the alpha- and gamma-motoneurons; the premotor neurons in the region of the rostral raphe pallidus, and the thermogenesis-promoting neurons in the dorsomedial hypothalamus/dorsal hypothalamic area. Also included are inputs to, and neurochemical modulators of, these efferent neuronal populations that could influence their activity during thermoregulatory responses. Signals of metabolic status can be particularly significant for the energy-hungry thermoeffectors for heat production.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States.
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Dore R, Levata L, Gachkar S, Jöhren O, Mittag J, Lehnert H, Schulz C. The thermogenic effect of nesfatin-1 requires recruitment of the melanocortin system. J Endocrinol 2017; 235:111-122. [PMID: 28851749 DOI: 10.1530/joe-17-0151] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 08/15/2017] [Indexed: 12/13/2022]
Abstract
Nesfatin-1 is a bioactive polypeptide expressed both in the brain and peripheral tissues and involved in the control of energy balance by reducing food intake. Central administration of nesfatin-1 significantly increases energy expenditure, as demonstrated by a higher dry heat loss; yet, the mechanisms underlying the thermogenic effect of central nesfatin-1 remain unknown. Therefore, in this study, we sought to investigate whether the increase in energy expenditure induced by nesfatin-1 is mediated by the central melanocortin pathway, which was previously reported to mediate central nesfatin-1´s effects on feeding and numerous other physiological functions. With the application of direct calorimetry, we found that intracerebroventricular nesfatin-1 (25 pmol) treatment increased dry heat loss and that this effect was fully blocked by simultaneous administration of an equimolar dose of the melanocortin 3/4 receptor antagonist, SHU9119. Interestingly, the nesfatin-1-induced increase in dry heat loss was positively correlated with body weight loss. In addition, as assessed with thermal imaging, intracerebroventricular nesfatin-1 (100 pmol) increased interscapular brown adipose tissue (iBAT) as well as tail temperature, suggesting increased heat production in the iBAT and heat dissipation over the tail surface. Finally, nesfatin-1 upregulated pro-opiomelanocortin and melanocortin 3 receptor mRNA expression in the hypothalamus, accompanied by a significant increase in iodothyronine deiodinase 2 and by a nonsignificant increase in uncoupling protein 1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha mRNA in the iBAT. Overall, we clearly demonstrate that nesfatin-1 requires the activation of the central melanocortin system to increase iBAT thermogenesis and, in turn, overall energy expenditure.
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Affiliation(s)
- Riccardo Dore
- Department of Internal Medicine ICenter of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Luka Levata
- Department of Internal Medicine ICenter of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Sogol Gachkar
- Department of Internal Medicine ICenter of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Olaf Jöhren
- Center of BrainBehavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Jens Mittag
- Department of Internal Medicine ICenter of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Hendrik Lehnert
- Department of Internal Medicine ICenter of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Carla Schulz
- Department of Internal Medicine ICenter of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
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Ryu V, Zarebidaki E, Albers HE, Xue B, Bartness TJ. Short photoperiod reverses obesity in Siberian hamsters via sympathetically induced lipolysis and Browning in adipose tissue. Physiol Behav 2017; 190:11-20. [PMID: 28694154 DOI: 10.1016/j.physbeh.2017.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/26/2017] [Accepted: 07/06/2017] [Indexed: 10/19/2022]
Abstract
Changes in photoperiod length are transduced into neuroendocrine signals by melatonin (MEL) secreted by the pineal gland triggering seasonally adaptive responses in many animal species. Siberian hamsters, transferred from a long-day 'summer-like' photoperiod (LD) to a short-day 'winter-like' photoperiod (SD), exhibit a naturally-occurring reversal in obesity. Photoperiod-induced changes in adiposity are mediated by the duration of MEL secretion and can be mimicked by exogenously administered MEL into animals housed in LD. Evidence suggests that MEL increases the sympathetic nervous system (SNS) drive to white adipose tissue (WAT). Here, we investigated whether MEL-driven seasonally adaptive losses in body fat are associated with WAT lipolysis and browning. Hamsters were subcutaneously administered vehicle (LD+VEH) or 0.4mg/kg MEL (LD+MEL) daily for 10weeks while animals housed in SD served as a positive control. MEL and SD exposure significantly decreased the retroperitoneal (RWAT), inguinal (IWAT), epididymal (EWAT) WAT, food intake and caused testicular regression compared with the LD+VEH group. MEL/SD induced lipolysis in the IWAT and EWAT, browning of the RWAT, IWAT, and EWAT, and increased UCP1 expression in the IBAT. Additionally, MEL/SD significantly increased the number of shared MEL receptor 1a and dopamine beta-hydroxylase-immunoreactive neurons in discrete brain sites, notably the paraventricular hypothalamic nucleus, dorsomedial hypothalamic nucleus, arcuate nucleus, locus coeruleus and dorsal motor nucleus of vagus. Collectively, these findings support our hypothesis that SD-exposed Siberian hamsters undergo adaptive decreases in body adiposity due to SNS-stimulated lipid mobilization and generalized WAT browning.
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Affiliation(s)
- Vitaly Ryu
- Department of Biology, Center for Obesity Reversal, Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-4010, USA.
| | - Eleen Zarebidaki
- Department of Biology, Center for Obesity Reversal, Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-4010, USA
| | - H Elliott Albers
- Department of Biology, Center for Obesity Reversal, Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-4010, USA
| | - Bingzhong Xue
- Department of Biology, Center for Obesity Reversal, Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-4010, USA
| | - Timothy J Bartness
- Department of Biology, Center for Obesity Reversal, Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-4010, USA
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35
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Silveira LAMD, Torquato BGS, Oliveira MS, Juliano GR, Oliveira LF, Cavellani CL, Ramalho LS, Espindula AP, Teixeira VDPA, Ferraz MLF. Implications of alcoholic cirrhosis in atherosclerosis of autopsied patients. Rev Assoc Med Bras (1992) 2017; 63:336-340. [PMID: 28614536 DOI: 10.1590/1806-9282.63.04.336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/19/2016] [Indexed: 11/21/2022] Open
Abstract
Introduction: Alcoholism is a major public health problem, which has a high social cost and affects many aspects of human activity. Liver disease is one of the first consequences of alcohol abuse, and steatosis, liver cirrhosis and hepatitis may occur. Other organs are also affected with pathological changes, such as pancreatitis, cardiomyopathies, dyslipidemias and atherosclerosis. Objective: To identify the occurrence and degree of atherosclerosis in alcohol-dependent individuals with liver cirrhosis, observing macroscopic and microscopic changes in lipid and collagen deposits and in the liver. We also aimed to verify the association of lipid and collagen fiber deposits with gender, age and body mass index, and to relate alcoholism, liver cirrhosis and atherosclerosis. Method: We performed a study based on autopsy reports of patients with alcoholic liver cirrhosis, with analysis of aorta and liver fragments to verify the occurrence and degree of atherosclerosis, as well as collagen contents. Results: Microscopic atherosclerosis was higher in young subjects (early injury) and in patients with alcoholic liver cirrhosis. The macroscopic analysis of atherosclerosis in aortas showed that patients in more advanced age groups presented more severe classifications. Atherosclerosis, both micro and macroscopically, and the percentage of fibrosis in the liver and aorta were more expressive in females. Conclusion: Cirrhotic patients presented a higher percentage of fibrosis and lipidosis, and may represent a group susceptible to the accelerated progression of cardiovascular diseases. Investigative studies contribute to targeting health-promoting interventions, reducing the mortality and costs of treating cardiovascular disease.
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Affiliation(s)
- Luciano Alves Matias da Silveira
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Bianca Gonçalves Silva Torquato
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Mariana Silva Oliveira
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Guilherme Ribeiro Juliano
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Lívia Ferreira Oliveira
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Camila Lourencini Cavellani
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Luciana Santos Ramalho
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Ana Paula Espindula
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Vicente de Paula Antunes Teixeira
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Mara Lúcia Fonseca Ferraz
- General Pathology Sector, Biological and Natural Sciences Institute (ICBN), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
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36
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Contreras C, Nogueiras R, Diéguez C, Rahmouni K, López M. Traveling from the hypothalamus to the adipose tissue: The thermogenic pathway. Redox Biol 2017; 12:854-863. [PMID: 28448947 PMCID: PMC5406580 DOI: 10.1016/j.redox.2017.04.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 01/13/2023] Open
Abstract
Brown adipose tissue (BAT) is a specialized tissue critical for non-shivering thermogenesis producing heat through mitochondrial uncoupling; whereas white adipose tissue (WAT) is responsible of energy storage in the form of triglycerides. Another type of fat has been described, the beige adipose tissue; this tissue emerges in existing WAT depots but with thermogenic ability, a phenomenon known as browning. Several peripheral signals relaying information about energy status act in the brain, particularly the hypothalamus, to regulate thermogenesis in BAT and browning of WAT. Different hypothalamic areas have the capacity to regulate the thermogenic process in brown and beige adipocytes through the sympathetic nervous system (SNS). This review discusses important concepts and discoveries about the central control of thermogenesis as a trip that starts in the hypothalamus, and taking the sympathetic roads to reach brown and beige fat to modulate thermogenic functions.
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Affiliation(s)
- Cristina Contreras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
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37
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Pandit R, Beerens S, Adan RAH. Role of leptin in energy expenditure: the hypothalamic perspective. Am J Physiol Regul Integr Comp Physiol 2017; 312:R938-R947. [PMID: 28356295 DOI: 10.1152/ajpregu.00045.2016] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 01/08/2023]
Abstract
The adipocyte-derived hormone leptin is a peripheral signal that informs the brain about the metabolic status of an organism. Although traditionally viewed as an appetite-suppressing hormone, studies in the past decade have highlighted the role of leptin in energy expenditure. Leptin has been shown to increase energy expenditure in particular through its effects on the cardiovascular system and brown adipose tissue (BAT) thermogenesis via the hypothalamus. The current review summarizes the role of leptin signaling in various hypothalamic nuclei and its effects on the sympathetic nervous system to influence blood pressure, heart rate, and BAT thermogenesis. Specifically, the role of leptin signaling on three different hypothalamic nuclei, the dorsomedial hypothalamus, the ventromedial hypothalamus, and the arcuate nucleus, is reviewed. It is known that all of these brain regions influence the sympathetic nervous system activity and thereby regulate BAT thermogenesis and the cardiovascular system. Thus the current work focuses on how leptin signaling in specific neuronal populations within these hypothalamic nuclei influences certain aspects of energy expenditure.
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Affiliation(s)
- R Pandit
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - S Beerens
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R A H Adan
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
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38
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Almundarij TI, Gavini CK, Novak CM. Suppressed sympathetic outflow to skeletal muscle, muscle thermogenesis, and activity energy expenditure with calorie restriction. Physiol Rep 2017; 5:5/4/e13171. [PMID: 28242830 PMCID: PMC5328781 DOI: 10.14814/phy2.13171] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 01/29/2017] [Indexed: 12/21/2022] Open
Abstract
During weight loss, adaptive thermogenesis occurs where energy expenditure (EE) is suppressed beyond that predicted for the smaller body size. Here, we investigated the contributions of resting and nonresting EE to the reduced total EE seen after 3 weeks of 50% calorie restriction (CR) in rats, focusing on activity‐associated EE, muscle thermogenesis, and sympathetic outflow. Prolonged food restriction resulted in a 42% reduction in daily EE, through a 40% decrease in resting EE, and a 48% decline in nonresting EE. These decreases in EE were significant even when the reductions in body weight and lean mass were taken into account. Along with a decreased caloric need for low‐to‐moderate‐intensity treadmill activity with 50% CR, baseline and activity‐related muscle thermogenesis were also suppressed, though the ability to increase muscle thermogenesis above baseline levels was not compromised. When sympathetic drive was measured by assessing norepinephrine turnover (NETO), 50% CR was found to decrease NETO in three of the four muscle groups examined, whereas elevated NETO was found in white adipose tissue of food‐restricted rats. Central activation of melanocortin 4 receptors in the ventromedial hypothalamus stimulated this pathway, enhancing activity EE; this was not compromised by 50% CR. These data suggest that suppressed activity EE contributes to adaptive thermogenesis during energy restriction. This may stem from decreased sympathetic drive to skeletal muscle, increasing locomotor efficiency and reducing skeletal muscle thermogenesis. The capacity to increase activity EE in response to central stimuli is retained, however, presenting a potential target for preventing weight regain.
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Affiliation(s)
- Tariq I Almundarij
- College of Agriculture and Veterinary Medicine, Al Qassim University, Buraydah, Al-Qassim Province, Saudi Arabia.,Department of Biological Sciences, Kent State University, Kent, Ohio
| | - Chaitanya K Gavini
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois.,School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Colleen M Novak
- Department of Biological Sciences, Kent State University, Kent, Ohio .,School of Biomedical Sciences, Kent State University, Kent, Ohio
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39
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Ryu V, Watts AG, Xue B, Bartness TJ. Bidirectional crosstalk between the sensory and sympathetic motor systems innervating brown and white adipose tissue in male Siberian hamsters. Am J Physiol Regul Integr Comp Physiol 2017; 312:R324-R337. [PMID: 28077392 DOI: 10.1152/ajpregu.00456.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/28/2016] [Accepted: 12/31/2016] [Indexed: 01/31/2023]
Abstract
The brain networks connected to the sympathetic motor and sensory innervations of brown (BAT) and white (WAT) adipose tissues were originally described using two transneuronally transported viruses: the retrogradely transported pseudorabies virus (PRV), and the anterogradely transported H129 strain of herpes simplex virus-1 (HSV-1 H129). Further complexity was added to this network organization when combined injections of PRV and HSV-1 H129 into either BAT or WAT of the same animal generated sets of coinfected neurons in the brain, spinal cord, and sympathetic and dorsal root ganglia. These neurons are well positioned to act as sensorimotor links in the feedback circuits that control each fat pad. We have now determined the extent of sensorimotor crosstalk between interscapular BAT (IBAT) and inguinal WAT (IWAT). PRV152 and HSV-1 H129 were each injected into IBAT or IWAT of the same animal: H129 into IBAT and PRV152 into IWAT. The reverse configuration was applied in a different set of animals. We found single-labeled neurons together with H129+PRV152 coinfected neurons in multiple brain sites, with lesser numbers in the sympathetic and dorsal root ganglia that innervate IBAT and IWAT. We propose that these coinfected neurons mediate sensory-sympathetic motor crosstalk between IBAT and IWAT. Comparing the relative numbers of coinfected neurons between the two injection configurations showed a bias toward IBAT-sensory and IWAT-sympathetic motor feedback loops. These coinfected neurons provide a neuroanatomical framework for functional interactions between IBAT thermogenesis and IWAT lipolysis that occurs with cold exposure, food restriction/deprivation, exercise, and more generally with alterations in adiposity.
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Affiliation(s)
- Vitaly Ryu
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
| | - Alan G Watts
- Department of Biological Sciences, University of Southern California, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California
| | - Bingzhong Xue
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
| | - Timothy J Bartness
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
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40
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Contreras C, Nogueiras R, Diéguez C, Medina-Gómez G, López M. Hypothalamus and thermogenesis: Heating the BAT, browning the WAT. Mol Cell Endocrinol 2016; 438:107-115. [PMID: 27498420 DOI: 10.1016/j.mce.2016.08.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/30/2016] [Accepted: 08/01/2016] [Indexed: 12/20/2022]
Abstract
Brown adipose tissue (BAT) has been also considered as the main thermogenic organ responsible of maintenance body temperature through heat production. However, a new type of thermogenic fat has been characterized during the last years, the beige or brite fat, that is developed from white adipose tissue (WAT) in response to different stimuli by a process known as browning. The activities of brown and beige adipocytes ameliorate metabolic disease, including obesity in mice and correlate with leanness in humans. Many genes and pathways that regulate brown and beige adipocyte biology have now been identified, providing a variety of promising therapeutic targets for metabolic disease. The hypothalamus is the main central place orchestrating the outflow signals that drive the sympathetic nerve activity to BAT and WAT, controlling heat production and energy homeostasis. Recent data have revealed new hypothalamic molecular mechanisms, such as hypothalamic AMP-activated protein kinase (AMPK), that control both thermogenesis and browning. This review provides an overview of the factors influencing BAT and WAT thermogenesis, with special focus on the integration of peripheral information on hypothalamic circuits controlling thermoregulation.
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Affiliation(s)
- Cristina Contreras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain.
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
| | - Gema Medina-Gómez
- Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Universidad Rey Juan Carlos, 28922, Alcorcón, Madrid, Spain
| | - Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain.
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41
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Nguyen NLT, Barr CL, Ryu V, Cao Q, Xue B, Bartness TJ. Separate and shared sympathetic outflow to white and brown fat coordinately regulates thermoregulation and beige adipocyte recruitment. Am J Physiol Regul Integr Comp Physiol 2016; 312:R132-R145. [PMID: 27881398 DOI: 10.1152/ajpregu.00344.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/14/2016] [Accepted: 11/05/2016] [Indexed: 11/22/2022]
Abstract
White adipose tissue (WAT) and brown adipose tissue (BAT) are innervated and regulated by the sympathetic nervous system (SNS). It is not clear, however, whether there are shared or separate central SNS outflows to WAT and BAT that regulate their function. We injected two isogenic strains of pseudorabies virus, a retrograde transneuronal viral tract tracer, with unique fluorescent reporters into interscapular BAT (IBAT) and inguinal WAT (IWAT) of the same Siberian hamsters to define SNS pathways to both. To test the functional importance of SNS coordinated control of BAT and WAT, we exposed hamsters with denervated SNS nerves to IBAT to 4°C for 16-24 h and measured core and fat temperatures and norepinephrine turnover (NETO) and uncoupling protein 1 (UCP1) expression in fat tissues. Overall, there were more SNS neurons innervating IBAT than IWAT across the neuroaxis. However, there was a greater percentage of singly labeled IWAT neurons in midbrain reticular nuclei than singly labeled IBAT neurons. The hindbrain had ~30-40% of doubly labeled neurons while the forebrain had ~25% suggesting shared SNS circuitry to BAT and WAT across the brain. The raphe nucleus, a key region in thermoregulation, had ~40% doubly labeled neurons. Hamsters with IBAT SNS denervation maintained core body temperature during acute cold challenge and had increased beige adipocyte formation in IWAT. They also had increased IWAT NETO, temperature, and UCP1 expression compared with intact hamsters. These data provide strong neuroanatomical and functional evidence of WAT and BAT SNS cross talk for thermoregulation and beige adipocyte formation.
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Affiliation(s)
- Ngoc Ly T Nguyen
- Department of Biology, Georgia State University, Atlanta, Georgia.,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia; and
| | - Candace L Barr
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
| | - Vitaly Ryu
- Department of Biology, Georgia State University, Atlanta, Georgia.,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia; and
| | - Qiang Cao
- Department of Biology, Georgia State University, Atlanta, Georgia.,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia; and
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, Georgia; .,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia; and.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
| | - Timothy J Bartness
- Department of Biology, Georgia State University, Atlanta, Georgia.,Center for Obesity Reversal, Georgia State University, Atlanta, Georgia; and.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
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42
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Contribution of adaptive thermogenesis to the hypothalamic regulation of energy balance. Biochem J 2016; 473:4063-4082. [DOI: 10.1042/bcj20160012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 08/13/2016] [Accepted: 08/30/2016] [Indexed: 12/12/2022]
Abstract
Obesity and its related disorders are among the most pervasive diseases in contemporary societies, and there is an urgent need for new therapies and preventive approaches. Given (i) our poor social capacity to correct unhealthy habits, and (ii) our evolutionarily genetic predisposition to store excess energy as fat, the current environment of caloric surplus makes the treatment of obesity extremely difficult. During the last few decades, an increasing number of methodological approaches have increased our knowledge of the neuroanatomical basis of the control of energy balance. Compelling evidence underlines the role of the hypothalamus as a homeostatic integrator of metabolic information and its ability to adjust energy balance. A greater understanding of the neural basis of the hypothalamic regulation of energy balance might indeed pave the way for new therapeutic targets. In this regard, it has been shown that several important peripheral signals, such as leptin, thyroid hormones, oestrogens and bone morphogenetic protein 8B, converge on common energy sensors, such as AMP-activated protein kinase to modulate sympathetic tone on brown adipose tissue. This knowledge may open new ways to counteract the chronic imbalance underlying obesity. Here, we review the current state of the art on the role of hypothalamus in the regulation of energy balance with particular focus on thermogenesis.
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43
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Chitravanshi VC, Kawabe K, Sapru HN. Stimulation of the hypothalamic arcuate nucleus increases brown adipose tissue nerve activity via hypothalamic paraventricular and dorsomedial nuclei. Am J Physiol Heart Circ Physiol 2016; 311:H433-44. [PMID: 27402666 DOI: 10.1152/ajpheart.00176.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 07/01/2016] [Indexed: 11/22/2022]
Abstract
Hypothalamic arcuate nucleus (ARCN) stimulation elicited increases in sympathetic nerve activity (IBATSNA) and temperature (TBAT) of interscapular brown adipose tissue (IBAT). The role of hypothalamic dorsomedial (DMN) and paraventricular (PVN) nuclei in mediating these responses was studied in urethane-anesthetized, artificially ventilated, male Wistar rats. In different groups of rats, inhibition of neurons in the DMN and PVN by microinjections of muscimol attenuated the increases in IBATSNA and TBAT elicited by microinjections of N-methyl-d-aspartic acid into the ipsilateral ARCN. In other groups of rats, blockade of ionotropic glutamate receptors by combined microinjections of D(-)-2-amino-7-phosphono-heptanoic acid (D-AP7) and NBQX into the DMN and PVN attenuated increases in IBATSNA and TBAT elicited by ARCN stimulation. Blockade of melanocortin 3/4 receptors in the DMN and PVN in other groups of rats resulted in attenuation of increases in IBATSNA and TBAT elicited by ipsilateral ARCN stimulation. Microinjections of Fluoro-Gold into the DMN resulted in retrograde labeling of cells in the ipsilateral ARCN, and some of these cells contained proopiomelanocortin (POMC), α-melanocyte-stimulating hormone (α-MSH), or vesicular glutamate transporter-3. Since similar projections from ARCN to the PVN have been reported by us and others, these results indicate that neurons containing POMC, α-MSH, and glutamate project from the ARCN to the DMN and PVN. Stimulation of ARCN results in the release of α-MSH and glutamate in the DMN and PVN which, in turn, cause increases in IBATSNA and TBAT.
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Affiliation(s)
- Vineet C Chitravanshi
- Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Kazumi Kawabe
- Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Hreday N Sapru
- Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, New Jersey
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Lipolysis sensation by white fat afferent nerves triggers brown fat thermogenesis. Mol Metab 2016; 5:626-634. [PMID: 27656400 PMCID: PMC5021673 DOI: 10.1016/j.molmet.2016.06.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 06/24/2016] [Accepted: 06/26/2016] [Indexed: 01/31/2023] Open
Abstract
Objective Metabolic challenges, such as a cold environment, stimulate sympathetic neural efferent activity to white adipose tissue (WAT) to drive lipolysis, thereby increasing the availability of free fatty acids as one source of fuel for brown adipose tissue (BAT) thermogenesis. WAT is also innervated by sensory nerve fibers that network to metabolic brain areas; moreover, activation of these afferents is reported to increase sympathetic nervous system outflow. However, the endogenous stimuli sufficient to drive WAT afferents during metabolic challenges as well as their functional relation to BAT thermogenesis remain unknown. Method We tested if local WAT lipolysis directly activates WAT afferent nerves, and then assessed whether this WAT sensory signal affected BAT thermogenesis in Siberian hamsters (Phodopus sungorus). Results 2-deoxyglucose, a sympathetic nervous system stimulant, caused β-adrenergic receptor dependent increases in inguinal WAT (IWAT) afferent neurophysiological activity. In addition, direct IWAT injections of the β3-AR agonist CL316,243 dose-dependently increased: 1) phosphorylation of IWAT hormone sensitive lipase, an indicator of SNS-stimulated lipolysis, 2) expression of the neuronal activation marker c-Fos in dorsal root ganglion neurons receiving sensory input from IWAT, and 3) IWAT afferent neurophysiological activity, an increase blocked by antilipolytic agent 3,5-dimethylpyrazole. Finally, we demonstrated that IWAT afferent activation by lipolysis triggers interscapular BAT thermogenesis through a neural link between these two tissues. Conclusions These data suggest IWAT lipolysis activates local IWAT afferents triggering a neural circuit from WAT to BAT that acutely induces BAT thermogenesis. Glucoprivation-induced lipolysis activates sensory nerves from white fat via β-adrenoreceptors. Lipolysis sensation by local afferent nerves innervating white fat is proposed. Lipid products of lipolysis are sufficient to activate sensory nerves from white fat. Stimulation of white fat afferents by lipolysis increases brown fat temperature. Findings illustrate functional neural connectivity between white and brown fat.
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Melanocortin-4 receptor-regulated energy homeostasis. Nat Neurosci 2016; 19:206-19. [PMID: 26814590 DOI: 10.1038/nn.4202] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/13/2015] [Indexed: 12/11/2022]
Abstract
The melanocortin system provides a conceptual blueprint for the central control of energetic state. Defined by four principal molecular components--two antagonistically acting ligands and two cognate receptors--this phylogenetically conserved system serves as a prototype for hierarchical energy balance regulation. Over the last decade the application of conditional genetic techniques has facilitated the neuroanatomical dissection of the melanocortinergic network and identified the specific neural substrates and circuits that underscore the regulation of feeding behavior, energy expenditure, glucose homeostasis and autonomic outflow. In this regard, the melanocortin-4 receptor is a critical coordinator of mammalian energy homeostasis and body weight. Drawing on recent advances in neuroscience and genetic technologies, we consider the structure and function of the melanocortin-4 receptor circuitry and its role in energy homeostasis.
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Labbé SM, Caron A, Lanfray D, Monge-Rofarello B, Bartness TJ, Richard D. Hypothalamic control of brown adipose tissue thermogenesis. Front Syst Neurosci 2015; 9:150. [PMID: 26578907 PMCID: PMC4630288 DOI: 10.3389/fnsys.2015.00150] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 10/20/2015] [Indexed: 12/21/2022] Open
Abstract
It has long been known, in large part from animal studies, that the control of brown adipose tissue (BAT) thermogenesis is insured by the central nervous system (CNS), which integrates several stimuli in order to control BAT activation through the sympathetic nervous system (SNS). SNS-mediated BAT activity is governed by diverse neurons found in brain structures involved in homeostatic regulations and whose activity is modulated by various factors including oscillations of energy fluxes. The characterization of these neurons has always represented a challenging issue. The available literature suggests that the neuronal circuits controlling BAT thermogenesis are largely part of an autonomic circuitry involving the hypothalamus, brainstem and the SNS efferent neurons. In the present review, we recapitulate the latest progresses in regards to the hypothalamic regulation of BAT metabolism. We briefly addressed the role of the thermoregulatory pathway and its interactions with the energy balance systems in the control of thermogenesis. We also reviewed the involvement of the brain melanocortin and endocannabinoid systems as well as the emerging role of steroidogenic factor 1 (SF1) neurons in BAT thermogenesis. Finally, we examined the link existing between these systems and the homeostatic factors that modulate their activities.
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Affiliation(s)
- Sebastien M Labbé
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Alexandre Caron
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Damien Lanfray
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Boris Monge-Rofarello
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Timothy J Bartness
- Department of Biology, Center for Obesity Reversal (COR), Georgia State University Atlanta, GA, USA
| | - Denis Richard
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
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Seoane-Collazo P, Fernø J, Gonzalez F, Diéguez C, Leis R, Nogueiras R, López M. Hypothalamic-autonomic control of energy homeostasis. Endocrine 2015; 50:276-91. [PMID: 26089260 DOI: 10.1007/s12020-015-0658-y] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 06/06/2015] [Indexed: 10/23/2022]
Abstract
Regulation of energy homeostasis is tightly controlled by the central nervous system (CNS). Several key areas such as the hypothalamus and brainstem receive and integrate signals conveying energy status from the periphery, such as leptin, thyroid hormones, and insulin, ultimately leading to modulation of food intake, energy expenditure (EE), and peripheral metabolism. The autonomic nervous system (ANS) plays a key role in the response to such signals, innervating peripheral metabolic tissues, including brown and white adipose tissue (BAT and WAT), liver, pancreas, and skeletal muscle. The ANS consists of two parts, the sympathetic and parasympathetic nervous systems (SNS and PSNS). The SNS regulates BAT thermogenesis and EE, controlled by central areas such as the preoptic area (POA) and the ventromedial, dorsomedial, and arcuate hypothalamic nuclei (VMH, DMH, and ARC). The SNS also regulates lipid metabolism in WAT, controlled by the lateral hypothalamic area (LHA), VMH, and ARC. Control of hepatic glucose production and pancreatic insulin secretion also involves the LHA, VMH, and ARC as well as the dorsal vagal complex (DVC), via splanchnic sympathetic and the vagal parasympathetic nerves. Muscle glucose uptake is also controlled by the SNS via hypothalamic nuclei such as the VMH. There is recent evidence of novel pathways connecting the CNS and ANS. These include the hypothalamic AMP-activated protein kinase-SNS-BAT axis which has been demonstrated to be a key modulator of thermogenesis. In this review, we summarize current knowledge of the role of the ANS in the modulation of energy balance.
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Affiliation(s)
- Patricia Seoane-Collazo
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain.
| | - Johan Fernø
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- Department of Clinical Science, K. G. Jebsen Center for Diabetes Research, University of Bergen, 5021, Bergen, Norway
| | - Francisco Gonzalez
- Department of Surgery, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- Service of Ophthalmology, Complejo Hospitalario Universitario de Santiago de Compostela, 15706, Santiago de Compostela, Spain
| | - Carlos Diéguez
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Rosaura Leis
- Unit of Investigation in Nutrition, Growth and Human Development of Galicia, Pediatric Department (USC), Complexo Hospitalario Universitario de Santiago (IDIS/SERGAS), Santiago de Compostela, Spain
| | - Rubén Nogueiras
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Miguel López
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain.
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Abstract
Obesity ensues from an imbalance between energy intake and expenditure that results from gene-environment interactions, which favour a positive energy balance. A society that promotes unhealthy food and encourages sedentary lifestyle (that is, an obesogenic environment) has become a major contributory factor in excess fat deposition in individuals predisposed to obesity. Energy homeostasis relies upon control of energy intake as well as expenditure, which is in part determined by the themogenesis of brown adipose tissue and mediated by the sympathetic nervous system. Several areas of the brain that constitute cognitive and autonomic brain systems, which in turn form networks involved in the control of appetite and thermogenesis, also contribute to energy homeostasis. These networks include the dopamine mesolimbic circuit, as well as the opioid, endocannabinoid and melanocortin systems. The activity of these networks is modulated by peripheral factors such as hormones derived from adipose tissue and the gut, which access the brain via the circulation and neuronal signalling pathways to inform the central nervous system about energy balance and nutritional status. In this Review, I focus on the determinants of energy homeostasis that have emerged as prominent factors relevant to obesity.
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Affiliation(s)
- Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada
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Morrison SF, Madden CJ. Central nervous system regulation of brown adipose tissue. Compr Physiol 2015; 4:1677-713. [PMID: 25428857 DOI: 10.1002/cphy.c140013] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thermogenesis, the production of heat energy, in brown adipose tissue is a significant component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature in many species from mouse to man and plays a key role in elevating body temperature during the febrile response to infection. The sympathetic neural outflow determining brown adipose tissue (BAT) thermogenesis is regulated by neural networks in the CNS which increase BAT sympathetic nerve activity in response to cutaneous and deep body thermoreceptor signals. Many behavioral states, including wakefulness, immunologic responses, and stress, are characterized by elevations in core body temperature to which central command-driven BAT activation makes a significant contribution. Since energy consumption during BAT thermogenesis involves oxidation of lipid and glucose fuel molecules, the CNS network driving cold-defensive and behavioral state-related BAT activation is strongly influenced by signals reflecting the short- and long-term availability of the fuel molecules essential for BAT metabolism and, in turn, the regulation of BAT thermogenesis in response to metabolic signals can contribute to energy balance, regulation of body adipose stores and glucose utilization. This review summarizes our understanding of the functional organization and neurochemical influences within the CNS networks that modulate the level of BAT sympathetic nerve activity to produce the thermoregulatory and metabolic alterations in BAT thermogenesis and BAT energy expenditure that contribute to overall energy homeostasis and the autonomic support of behavior.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
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Morgan DA, McDaniel LN, Yin T, Khan M, Jiang J, Acevedo MR, Walsh SA, Ponto LLB, Norris AW, Lutter M, Rahmouni K, Cui H. Regulation of glucose tolerance and sympathetic activity by MC4R signaling in the lateral hypothalamus. Diabetes 2015; 64:1976-87. [PMID: 25605803 PMCID: PMC4439564 DOI: 10.2337/db14-1257] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/10/2015] [Indexed: 02/06/2023]
Abstract
Melanocortin 4 receptor (MC4R) signaling mediates diverse physiological functions, including energy balance, glucose homeostasis, and autonomic activity. Although the lateral hypothalamic area (LHA) is known to express MC4Rs and to receive input from leptin-responsive arcuate proopiomelanocortin neurons, the physiological functions of MC4Rs in the LHA are incompletely understood. We report that MC4R(LHA) signaling regulates glucose tolerance and sympathetic nerve activity. Restoring expression of MC4Rs specifically in the LHA improves glucose intolerance in obese MC4R-null mice without affecting body weight or circulating insulin levels. Fluorodeoxyglucose-mediated tracing of whole-body glucose uptake identifies the interscapular brown adipose tissue (iBAT) as a primary source where glucose uptake is increased in MC4R(LHA) mice. Direct multifiber sympathetic nerve recording further reveals that sympathetic traffic to iBAT is significantly increased in MC4R(LHA) mice, which accompanies a significant elevation of Glut4 expression in iBAT. Finally, bilateral iBAT denervation prevents the glucoregulatory effect of MC4R(LHA) signaling. These results identify a novel role for MC4R(LHA) signaling in the control of sympathetic nerve activity and glucose tolerance independent of energy balance.
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Affiliation(s)
- Donald A Morgan
- Department of Pharmacology, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Latisha N McDaniel
- Department of Psychiatry, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Terry Yin
- Department of Psychiatry, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Michael Khan
- Department of Psychiatry, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Jingwei Jiang
- Department of Pharmacology, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Michael R Acevedo
- Small Animal Imaging Core, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Susan A Walsh
- Small Animal Imaging Core, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Laura L Boles Ponto
- Department of Radiology, University of Iowa, Carver College of Medicine, Iowa City, IA Department of Pediatrics, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Andrew W Norris
- Department of Pediatrics, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Michael Lutter
- Department of Psychiatry, University of Iowa, Carver College of Medicine, Iowa City, IA Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, IA Obesity Research and Education Initiative, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Carver College of Medicine, Iowa City, IA Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, IA Obesity Research and Education Initiative, University of Iowa, Carver College of Medicine, Iowa City, IA
| | - Huxing Cui
- Department of Pharmacology, University of Iowa, Carver College of Medicine, Iowa City, IA Department of Psychiatry, University of Iowa, Carver College of Medicine, Iowa City, IA Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, IA
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