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Busebee B, Ghusn W, Cifuentes L, Acosta A. Obesity: A Review of Pathophysiology and Classification. Mayo Clin Proc 2023; 98:1842-1857. [PMID: 37831039 PMCID: PMC10843116 DOI: 10.1016/j.mayocp.2023.05.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 05/18/2023] [Accepted: 05/30/2023] [Indexed: 10/14/2023]
Abstract
Obesity is a chronic, multifactorial, and morbid disease. In the United States, 69% of adults are overweight or have obesity, and the global prevalence of obesity is increasing. Obesity is influenced by genetic, neurologic, metabolic, enteric, and behavioral processes. It remains a key modifiable risk factor for many comorbid diseases, including cardiovascular disease, diabetes mellitus, and cancer. Whereas there are recent and significant advances in obesity therapy, including diets, lifestyle modifications, pharmacotherapies, endoscopic procedures, and bariatric surgeries, there is an immense need for a better understanding of the heterogeneity in the pathophysiologic process of obesity and outcomes. Here we review salient pathophysiologic mechanisms underlying the development and morbidity of obesity as well as pathophysiologically based classification systems that inform current obesity management and may inform improved and individualized management in the future.
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Affiliation(s)
| | - Wissam Ghusn
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Lizeth Cifuentes
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Andres Acosta
- Precision Medicine for Obesity Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN.
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2
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Impaired Ghrelin Signaling Does Not Lead to Alterations of Anxiety-like Behaviors in Adult Mice Chronically Exposed to THC during Adolescence. Biomedicines 2023; 11:biomedicines11010144. [PMID: 36672651 PMCID: PMC9855766 DOI: 10.3390/biomedicines11010144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/17/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
As marijuana use during adolescence has been increasing, the need to understand the effects of its long-term use becomes crucial. Previous research suggested that marijuana consumption during adolescence increases the risk of developing mental illnesses, such as schizophrenia, depression, and anxiety. Ghrelin is a peptide produced primarily in the gut and is important for feeding behavior. Recent studies have shown that ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR), play important roles in mediating stress, as well as anxiety and depression-like behaviors in animal models. Here, we investigated the effects of chronic tetrahydrocannabinol (THC) administration during late adolescence (P42-55) in GHSR (GHSR -/-) knockout mice and their wild-type littermates in relation to anxiety-like behaviors. We determined that continuous THC exposure during late adolescence did not lead to any significant alterations in the anxiety-like behaviors of adult mice, regardless of genotype, following a prolonged period of no exposure (1 month). These data indicate that in the presence of intact or impaired ghrelin/GHSR signaling, THC exposure during late adolescence has limited if any long-term impact on anxiety-like behaviors in mice.
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3
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Kempf E, Landgraf K, Stein R, Hanschkow M, Hilbert A, Abou Jamra R, Boczki P, Herberth G, Kühnapfel A, Tseng YH, Stäubert C, Schöneberg T, Kühnen P, Rayner NW, Zeggini E, Kiess W, Blüher M, Körner A. Aberrant expression of agouti signaling protein (ASIP) as a cause of monogenic severe childhood obesity. Nat Metab 2022; 4:1697-1712. [PMID: 36536132 PMCID: PMC9771800 DOI: 10.1038/s42255-022-00703-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/31/2022] [Indexed: 12/24/2022]
Abstract
Here we report a heterozygous tandem duplication at the ASIP (agouti signaling protein) gene locus causing ubiquitous, ectopic ASIP expression in a female patient with extreme childhood obesity. The mutation places ASIP under control of the ubiquitously active itchy E3 ubiquitin protein ligase promoter, driving the generation of ASIP in patient-derived native and induced pluripotent stem cells for all germ layers and hypothalamic-like neurons. The patient's phenotype of early-onset obesity, overgrowth, red hair and hyperinsulinemia is concordant with that of mutant mice ubiquitously expressing the homolog nonagouti. ASIP represses melanocyte-stimulating hormone-mediated activation as a melanocortin receptor antagonist, which might affect eating behavior, energy expenditure, adipocyte differentiation and pigmentation, as observed in the index patient. As the type of mutation escapes standard genetic screening algorithms, we rescreened the Leipzig Childhood Obesity cohort of 1,745 patients and identified four additional patients with the identical mutation, ectopic ASIP expression and a similar phenotype. Taken together, our data indicate that ubiquitous ectopic ASIP expression is likely a monogenic cause of human obesity.
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Affiliation(s)
- Elena Kempf
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Kathrin Landgraf
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Robert Stein
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany
- Helmholtz Institute for Metabolic Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Martha Hanschkow
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Anja Hilbert
- Department of Psychosomatic Medicine and Psychotherapy, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Rami Abou Jamra
- University Medical Center Leipzig, Institute of Human Genetics, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Paula Boczki
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Gunda Herberth
- Department of Environmental Immunology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Andreas Kühnapfel
- Institute for Medical Informatics, Statistics and Epidemiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Yu-Hua Tseng
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Claudia Stäubert
- Division of Molecular Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Torsten Schöneberg
- Division of Molecular Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Peter Kühnen
- Institute for Experimental Pediatric Endocrinology, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - N William Rayner
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Eleftheria Zeggini
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- TUM School of Medicine, Translational Genomics, Technical University of Munich and Klinikum Rechts der Isar, Munich, Germany
| | - Wieland Kiess
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany
- LIFE-Leipzig Research Center for Civilization Diseases, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Matthias Blüher
- Helmholtz Institute for Metabolic Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
- Medical Department III-Endocrinology, Nephrology, Rheumatology, University of Leipzig, Leipzig, Germany
| | - Antje Körner
- University Hospital for Children and Adolescents, Center for Pediatric Research, Medical Faculty, University of Leipzig, Leipzig, Germany.
- Helmholtz Institute for Metabolic Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany.
- LIFE-Leipzig Research Center for Civilization Diseases, Medical Faculty, University of Leipzig, Leipzig, Germany.
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4
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Tran LT, Park S, Kim SK, Lee JS, Kim KW, Kwon O. Hypothalamic control of energy expenditure and thermogenesis. Exp Mol Med 2022; 54:358-369. [PMID: 35301430 PMCID: PMC9076616 DOI: 10.1038/s12276-022-00741-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 12/05/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Energy expenditure and energy intake need to be balanced to maintain proper energy homeostasis. Energy homeostasis is tightly regulated by the central nervous system, and the hypothalamus is the primary center for the regulation of energy balance. The hypothalamus exerts its effect through both humoral and neuronal mechanisms, and each hypothalamic area has a distinct role in the regulation of energy expenditure. Recent studies have advanced the understanding of the molecular regulation of energy expenditure and thermogenesis in the hypothalamus with targeted manipulation techniques of the mouse genome and neuronal function. In this review, we elucidate recent progress in understanding the mechanism of how the hypothalamus affects basal metabolism, modulates physical activity, and adapts to environmental temperature and food intake changes. The hypothalamus is a key regulator of metabolism, controlling resting metabolism, activity levels, and responses to external temperature and food intake. The balance between energy intake and expenditure must be tightly controlled, with imbalances resulting in metabolic disorders such as obesity or diabetes. Obin Kwon at Seoul National University College of Medicine and Ki Woo Kim at Yonsei University College of Dentistry, Seoul, both in South Korea, and coworkers reviewed how metabolism is regulated by the hypothalamus, a small hormone-producing brain region. They report that hormonal and neuronal signals from the hypothalamus influence the ratio of lean to fatty tissue, gender-based differences in metabolism, activity levels, and weight gain in response to food intake. They note that further studies to untangle cause-and-effect relationships and other genetic factors will improve our understanding of metabolic regulation.
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Affiliation(s)
- Le Trung Tran
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Sohee Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Seul Ki Kim
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Jin Sun Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Ki Woo Kim
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea.
| | - Obin Kwon
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea. .,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.
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5
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Bukhari SNA. An insight into the multifunctional role of ghrelin and structure activity relationship studies of ghrelin receptor ligands with clinical trials. Eur J Med Chem 2022; 235:114308. [PMID: 35344905 DOI: 10.1016/j.ejmech.2022.114308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 02/06/2022] [Accepted: 03/18/2022] [Indexed: 11/30/2022]
Abstract
Ghrelin is a multifunctional gastrointestinal acylated peptide, primarily synthesized in the stomach and regulates the secretion of growth hormone and energy homeostasis. It plays a central role in modulating the diverse biological, physiological and pathological functions in vertebrates. The synthesis of ghrelin receptor ligands after the finding of growth hormone secretagogue developed from Met-enkephalin led to reveal the endogenous ligand ghrelin and the receptors. Subsequently, many peptides, small molecules and peptidomimetics focusing on the ghrelin receptor, GHS-R1a, were derived. In this review, the key features of ghrelin's structure, forms, its bio-physiological functions, pathological roles and therapeutic potential have been highlighted. A few peptidomimetics and pseudo peptide synthetic perspectives have also been discussed to make ghrelin receptor ligands, clinical trials and their success.
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Affiliation(s)
- Syed Nasir Abbas Bukhari
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka, Aljouf, 2014, Saudi Arabia.
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6
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Lv X, Gao F, Li TP, Xue P, Wang X, Wan M, Hu B, Chen H, Jain A, Shao Z, Cao X. Skeleton interoception regulates bone and fat metabolism through hypothalamic neuroendocrine NPY. eLife 2021; 10:e70324. [PMID: 34468315 PMCID: PMC8439655 DOI: 10.7554/elife.70324] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 05/21/2021] [Indexed: 01/04/2023] Open
Abstract
The central nervous system regulates activity of peripheral organs through interoception. In our previous study, we have demonstrated that PGE2/EP4 skeleton interception regulate bone homeostasis. Here, we show that ascending skeleton interoceptive signaling downregulates expression of hypothalamic neuropeptide Y (NPY) and induce lipolysis of adipose tissue for osteoblastic bone formation. Specifically, the ascending skeleton interoceptive signaling induces expression of small heterodimer partner-interacting leucine zipper protein (SMILE) in the hypothalamus. SMILE binds to pCREB as a transcriptional heterodimer on Npy promoters to inhibit NPY expression. Knockout of EP4 in sensory nerve increases expression of NPY causing bone catabolism and fat anabolism. Importantly, inhibition of NPY Y1 receptor (Y1R) accelerated oxidation of free fatty acids in osteoblasts and rescued bone loss in AvilCre:Ptger4fl/fl mice. Thus, downregulation of hypothalamic NPY expression lipolyzes free fatty acids for anabolic bone formation through a neuroendocrine descending interoceptive regulation.
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Affiliation(s)
- Xiao Lv
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Feng Gao
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Tuo Peter Li
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Peng Xue
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Xiao Wang
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Mei Wan
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Bo Hu
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Hao Chen
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Amit Jain
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
| | - Zengwu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Xu Cao
- Department of Orthopaedic Surgery, Institute of Cell Engineering, and Department of Biomedical Engineering, The Johns Hopkins UniversityBaltimoreUnited States
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7
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Stutte S, Ruf J, Kugler I, Ishikawa-Ankerhold H, Parzefall A, Marconi P, Maeda T, Kaisho T, Krug A, Popper B, Lauterbach H, Colonna M, von Andrian U, Brocker T. Type I interferon mediated induction of somatostatin leads to suppression of ghrelin and appetite thereby promoting viral immunity in mice. Brain Behav Immun 2021; 95:429-443. [PMID: 33895286 DOI: 10.1016/j.bbi.2021.04.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/06/2021] [Accepted: 04/20/2021] [Indexed: 12/18/2022] Open
Abstract
Loss of appetite (anorexia) is a typical behavioral response to infectious diseases that often reduces body weight. Also, anorexia can be observed in cancer and trauma patients, causing poor quality of life and reduced prospects of positive therapeutic outcomes. Although anorexia is an acute symptom, its initiation and endocrine regulation during antiviral immune responses are poorly understood. During viral infections, plasmacytoid dendritic cells (pDCs) produce abundant type I interferon (IFN-I) to initiate first-line defense mechanisms. Here, by targeted ablation of pDCs and various in vitro and in vivo mouse models of viral infection and inflammation, we identified that IFN-I is a significant driver of somatostatin (SST). Consequently, SST suppressed the hunger hormone ghrelin that led to severe metabolic changes, anorexia, and rapid body weight loss. Furthermore, during vaccination with Modified Vaccinia Ankara virus (MVA), the SST-mediated suppression of ghrelin was critical to viral immune response, as ghrelin restrained the production of early cytokines by natural killer (NK) cells and pDCs, and impaired the clonal expansion of CD8+ T cells. Thus, the hormonal modulation of ghrelin through SST and the cytokine IFN-I is fundamental for optimal antiviral immunity, which comes at the expense of calorie intake.
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Affiliation(s)
- Susanne Stutte
- Institute for Immunology, Faculty of Medicine, LMU Munich, Germany; Department of Immunology, Blavatnik Institute, Harvard Medical School, Boston, USA
| | - Janina Ruf
- Institute for Immunology, Faculty of Medicine, LMU Munich, Germany
| | - Ina Kugler
- Institute for Immunology, Faculty of Medicine, LMU Munich, Germany
| | | | - Andreas Parzefall
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Peggy Marconi
- Department of Chemical and Pharmaceutical Sciences (DipSCF), University of Ferrara, Italy
| | - Takahiro Maeda
- Departments of Island and Community Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1, Sakamoto, Nagasaki City, Japan
| | - Tsuneyasu Kaisho
- Department of Immunology, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan
| | - Anne Krug
- Institute for Immunology, Faculty of Medicine, LMU Munich, Germany
| | - Bastian Popper
- Biomedical Center (BMC), Core Facility Animal Models, Medical Faculty, LMU Munich, Germany
| | | | - Marco Colonna
- Washington University, School of Medicine, St. Louis, USA
| | - Ulrich von Andrian
- Department of Immunology, Blavatnik Institute, Harvard Medical School, Boston, USA
| | - Thomas Brocker
- Institute for Immunology, Faculty of Medicine, LMU Munich, Germany.
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8
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Quitadamo P, Zenzeri L, Mozzillo E, Giorgio V, Rocco A, Franzese A, Nardone G, Staiano A. Plasma dosage of ghrelin, IGF-1, GLP- 1 and leptin related to gastric emptying and esophageal pH-impedance in children with obesity. J Endocrinol Invest 2021; 44:1275-1281. [PMID: 32960416 DOI: 10.1007/s40618-020-01425-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 09/14/2020] [Indexed: 01/11/2023]
Abstract
PURPOSE The main aim of the study was to assess the relationship between leptin, ghrelin, insulin-like growth factor 1 (IGF-1), and glucagon-like peptide 1 (GLP-1) blood levels and gastric motility in children with obesity compared to healthy children. Secondary aims were to assess the possible association between these hormones and obesity, reflux impedance parameters, reflux symptoms, other GI disorders, and quality-of-life scores within the same groups. METHODS Children with obesity plus GERD symptoms and 2 control groups of children with obesity without GERD and healthy lean children aged 4-17 years underwent an auxological evaluation, an assessment of gastro-intestinal symptoms and quality of life, hormonal dosages, and an evaluation of gastric emptying time (GET) through 13C-octanoic acid breath test. RESULTS No significant association was found between hormones and gastric motility. Leptin and ghrelin levels were significantly associated with obesity parameters. No significant differences were found between GET and hormones of the patients with obesity, either with or without GERD. CONCLUSION Although we found an association between auxological parameters and both leptin and ghrelin levels, this association did not imply an effect on the upper GI motility. Therefore, our hypothesis that alterations of these hormones in children with obesity could affect gastric emptying, triggering GERD, was not supported by our data.
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Affiliation(s)
- P Quitadamo
- Department of Translational Medical Science, Section of Pediatrics, "Federico II" University of Naples, Naples, Italy.
- Department of Pediatrics, A.O.R.N. Santobono-Pausilipon, Via Mario Fiore 6, 80129, Naples, Italy.
| | - L Zenzeri
- Department of Pediatrics, University of Perugia, Perugia, Italy
| | - E Mozzillo
- Department of Translational Medical Science, Section of Pediatrics, "Federico II" University of Naples, Naples, Italy
| | - V Giorgio
- UOC Pediatria, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - A Rocco
- Department of Gastroenterology, "Federico II" University of Naples, Naples, Italy
| | - A Franzese
- Department of Translational Medical Science, Section of Pediatrics, "Federico II" University of Naples, Naples, Italy
| | - G Nardone
- Department of Gastroenterology, "Federico II" University of Naples, Naples, Italy
| | - A Staiano
- Department of Translational Medical Science, Section of Pediatrics, "Federico II" University of Naples, Naples, Italy
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9
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Liang Y, Yin W, Yin Y, Zhang W. Ghrelin Based Therapy of Metabolic Diseases. Curr Med Chem 2021; 28:2565-2576. [PMID: 32538716 PMCID: PMC11213490 DOI: 10.2174/0929867327666200615152804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/04/2020] [Accepted: 05/18/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Ghrelin, a unique 28 amino acid peptide hormone secreted by the gastric X/A like cells, is an endogenous ligand of the growth hormone secretagogue receptor (GHSR). Ghrelin-GHSR signaling has been found to exert various physiological functions, including stimulation of appetite, regulation of body weight, lipid and glucose metabolism, and increase of gut motility and secretion. This system is thus critical for energy homeostasis. OBJECTIVE The objective of this review is to highlight the strategies of ghrelin-GHSR based intervention for therapy of obesity and its related metabolic diseases. RESULTS Therapeutic strategies of metabolic disorders targeting the ghrelin-GHSR pathway involve neutralization of circulating ghrelin by antibodies and RNA spiegelmers, antagonism of ghrelin receptor by its antagonists and inverse agonists, inhibition of ghrelin O-acyltransferase (GOAT), as well as potential pharmacological approach to decrease ghrelin synthesis and secretion. CONCLUSION Various compounds targeting the ghrelin-GHSR system have shown promising efficacy for the intervention of obesity and relevant metabolic disorders in animals and in vitro. Further clinical trials to validate their efficacy in human beings are urgently needed.
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Affiliation(s)
- Yuan Liang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wenzhen Yin
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yue Yin
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Weizhen Zhang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA
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10
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Beheshti S, Sami M, Mirzabeh A, Yazdi A. D-Lys-3-GHRP-6 impairs memory consolidation and downregulates the hippocampal serotonin HT1A, HT7 receptors and glutamate GluA1 subunit of AMPA receptors. Physiol Behav 2020; 223:112969. [DOI: 10.1016/j.physbeh.2020.112969] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 04/27/2020] [Accepted: 05/12/2020] [Indexed: 01/08/2023]
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11
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Beutler LR, Corpuz TV, Ahn JS, Kosar S, Song W, Chen Y, Knight ZA. Obesity causes selective and long-lasting desensitization of AgRP neurons to dietary fat. eLife 2020; 9:e55909. [PMID: 32720646 PMCID: PMC7398661 DOI: 10.7554/elife.55909] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/20/2020] [Indexed: 12/12/2022] Open
Abstract
Body weight is regulated by interoceptive neural circuits that track energy need, but how the activity of these circuits is altered in obesity remains poorly understood. Here we describe the in vivo dynamics of hunger-promoting AgRP neurons during the development of diet-induced obesity in mice. We show that high-fat diet attenuates the response of AgRP neurons to an array of nutritionally-relevant stimuli including food cues, intragastric nutrients, cholecystokinin and ghrelin. These alterations are specific to dietary fat but not carbohydrate or protein. Subsequent weight loss restores the responsiveness of AgRP neurons to exterosensory cues but fails to rescue their sensitivity to gastrointestinal hormones or nutrients. These findings reveal that obesity triggers broad dysregulation of hypothalamic hunger neurons that is incompletely reversed by weight loss and may contribute to the difficulty of maintaining a reduced weight.
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Affiliation(s)
| | | | - Jamie S Ahn
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Seher Kosar
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Weimin Song
- Northwestern University Feinberg School of Medicine, Comprehensive Metabolic CoreChicagoUnited States
| | - Yiming Chen
- UCSF Department of PhysiologySan FranciscoUnited States
- UCSF Neuroscience Graduate ProgramSan FranciscoUnited States
| | - Zachary A Knight
- Howard Hughes Medical InstituteChevy ChaseUnited States
- UCSF Department of PhysiologySan FranciscoUnited States
- UCSF Neuroscience Graduate ProgramSan FranciscoUnited States
- Kavli Institute for Fundamental NeuroscienceSan FranciscoUnited States
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12
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Gaspar JM, Velloso LA. Hypoxia Inducible Factor as a Central Regulator of Metabolism - Implications for the Development of Obesity. Front Neurosci 2018; 12:813. [PMID: 30443205 PMCID: PMC6221908 DOI: 10.3389/fnins.2018.00813] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/18/2018] [Indexed: 12/19/2022] Open
Abstract
The hypothalamus plays a major role in the regulation of food intake and energy expenditure. In the last decade, it was demonstrated that consumption of high-fat diets triggers the activation of an inflammatory process in the hypothalamus, inducing neurofunctional alterations and contributing to the development of obesity. Hypoxia-inducible factors (HIFs) are key molecules that regulate cellular responses to inflammation and hypoxia, being essential for the normal cell function and survival. Currently, evidence points to a role of HIF pathway in metabolic regulation that could also be involved in the progression of obesity and metabolic diseases. The challenge is to understand how HIF modulation impacts body mass gain and metabolic disorders such as insulin resistance. Distinct animal models with tissue-specific knocking-out or overexpression of hypoxia signaling pathway genes revealed a cell-specificity in the activation of HIF pathways, and some of them have opposite phenotypes among the various HIFs gain- and loss-of-function mouse models. In this review, we discuss the major findings that provide support for a role of HIF pathway involvement in the regulation of metabolism, especially in glucose and energy homeostasis.
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Affiliation(s)
- Joana M Gaspar
- Post-Graduation in Biochemistry, Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Brazil.,Laboratório de Bioenergética e Estresse Oxidativo, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Lício A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
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Dornellas APS, Boldarine VT, Pedroso AP, Carvalho LOT, de Andrade IS, Vulcani-Freitas TM, dos Santos CCC, do Nascimento CMDPO, Oyama LM, Ribeiro EB. High-Fat Feeding Improves Anxiety-Type Behavior Induced by Ovariectomy in Rats. Front Neurosci 2018; 12:557. [PMID: 30233288 PMCID: PMC6129615 DOI: 10.3389/fnins.2018.00557] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/24/2018] [Indexed: 12/11/2022] Open
Abstract
Menopause-induced changes may include increased incidence of both depression/anxiety and obesity. We hypothesized that behavioral changes that may develop after ovarian failure could be related to neurochemical and metabolic aspects affected by this condition and that high-fat intake may influence these associations. The present study investigated in rats the effects of ovariectomy, either alone or combined with high-fat diets enriched with either lard or fish-oil, on metabolic, behavioral and monoaminergic statuses, and on gene expression of neuropeptides and receptors involved in energy balance and mood regulation. Female rats had their ovaries removed and received either standard chow (OvxC) or high-fat diets enriched with either lard (OvxL) or fish-oil (OvxF) for 8 weeks. The Sham group received only chow diet. Ovariectomy increased feed efficiency and body weight gain and impaired glucose homeostasis and serotonin-induced hypophagia, effects either maintained or even accentuated by the lard diet but counteracted by the fish diet. The OvxL group developed obesity and hyperleptinemia. Regarding components of hypothalamic serotonergic system, both ovariectomy alone or combined with the fish diet increased 5-HT2C expression while the lard diet reduced 5-HT1B mRNA. Ovariectomy increased the anxiety index, as derived from the elevated plus maze test, while both high-fat groups showed normalization of this index. In the forced swimming test, ovariectomy allied to high-lard diet, but not to fish-oil diet, reduced the latency to immobility, indicating vulnerability to a depressive-like state. Linear regression analysis showed hippocampal AgRP to be negatively associated with the anxiety index and hypothalamic AgRP to be positively associated with the latency to immobility. These AgRp gene expression associations are indicative of a beneficial involvement of this neuropeptide on both depression and anxiety measures. The present findings demonstrate metabolic, neurochemical and behavioral alterations after ovaries removal and highlight a positive effect of high-fat feeding on the anxiety-like behavior shown by ovariectomized animals. Since the polyunsaturated ômega-3 intake (fish diet), unlike the saturated fat intake (lard diet), failed to induce deleterious metabolic or neurochemical consequences, further studies are needed focusing on the potential of this dietary component as an adjuvant anxiolytic agent after menopause.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Eliane B. Ribeiro
- Physiology Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Targeting AgRP neurons to maintain energy balance: Lessons from animal models. Biochem Pharmacol 2018; 155:224-232. [PMID: 30012460 DOI: 10.1016/j.bcp.2018.07.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/12/2018] [Indexed: 01/19/2023]
Abstract
The current obesity epidemic is a major worldwide health and economic burden. In the modern environment, an increase in the intake of high-fat and high-sugar foods plays a crucial role in the development of obesity by disrupting the mechanisms governing food intake and energy balance. Food intake and whole-body energy balance are regulated by the central nervous system through a sophisticated neuronal network located mostly in the hypothalamus. In particular, the hypothalamic arcuate nucleus (ARC) is a fundamental center that senses hormonal and nutrient-related signals informing about the energy state of the organism. The ARC contains two small, defined populations of neurons with opposite functions: anorexigenic proopiomelanocortin (POMC)-expressing neurons and orexigenic Agouti-related protein (AgRP)-expressing neurons. AgRP neurons, which also co-produce neuropeptide Y (NPY) and γ-Aminobutyric acid (GABA), are involved in an increase in hunger and a decrease in energy expenditure. In this review, we summarize the key findings from the most common animal models targeting AgRP neurons and the tools used to discern the role of this specific neuronal population in the control of peripheral metabolism, appetite, feeding-related behavior, and other complex behaviors. We also discuss how knowledge gained from these studies has revealed new pathways and key proteins that could be potential therapeutic targets to reduce appetite and food addictions in obesity and other diseases.
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15
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Ogawa S, Liu X, Shepherd BS, Parhar IS. Ghrelin stimulates growth hormone release from the pituitary via hypothalamic growth hormone-releasing hormone neurons in the cichlid, Oreochromis niloticus. Cell Tissue Res 2018; 374:349-365. [PMID: 29934855 DOI: 10.1007/s00441-018-2870-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 06/04/2018] [Indexed: 12/25/2022]
Abstract
Ghrelin, a gut-brain peptide hormone, is implicated in a multiplicity of biological functions, including energy homeostasis and reproduction. Neuronal systems that are involved in energy homeostasis as well as reproduction traverse the hypothalamus; however, the mechanism by which they control energy homeostasis is not fully understood. The present study analyzes the anatomical relationship of neurons expressing gonadotropin-releasing hormone (GnRH), neuropeptide Y (NPY) and growth hormone-releasing hormone (GHRH) in a cichlid, tilapia (Oreochromis niloticus). Additionally, we examine in vivo effects of ghrelin on these hypothalamic neurons and plasma growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels. Double-immunofluorescence showed neuronal fiber associations between GnRH, NPY and GHRH in the brain and pituitary. Intracerebroventricular injection of ghrelin had no effect on numbers, soma size, or optical density of GnRH and NPY neurons, whereas the number of GHRH neurons was significantly decreased in the animals injected with ghrelin when compared to controls, which may indicate administered ghrelin promoted GHRH release. Plasma GH and pituitary GH mRNA levels were significantly increased in the animals injected with ghrelin. These results suggest that central administration of ghrelin primarily act on hypothalamic GHRH neurons to stimulate GH release from the pituitary in the tilapia.
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Affiliation(s)
- Satoshi Ogawa
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia
| | - Xiaochun Liu
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Brian S Shepherd
- USDA/ARS/School of Freshwater Sciences, University of Wisconsin, Milwaukee, WI, 53204, USA
| | - Ishwar S Parhar
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia.
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Lalonde R, Strazielle C. Neuroanatomical pathways underlying the effects of hypothalamo-hypophysial-adrenal hormones on exploratory activity. Rev Neurosci 2018; 28:617-648. [PMID: 28609296 DOI: 10.1515/revneuro-2016-0075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/16/2017] [Indexed: 12/25/2022]
Abstract
When injected via the intracerebroventricular route, corticosterone-releasing hormone (CRH) reduced exploration in the elevated plus-maze, the center region of the open-field, and the large chamber in the defensive withdrawal test. The anxiogenic action of CRH in the elevated plus-maze also occurred when infused in the basolateral amygdala, ventral hippocampus, lateral septum, bed nucleus of the stria terminalis, nucleus accumbens, periaqueductal grey, and medial frontal cortex. The anxiogenic action of CRH in the defensive withdrawal test was reproduced when injected in the locus coeruleus, while the amygdala, hippocampus, lateral septum, nucleus accumbens, and lateral globus pallidus contribute to center zone exploration in the open-field. In addition to elevated plus-maze and open-field tests, the amygdala appears as a target region for CRH-mediated anxiety in the elevated T-maze. Thus, the amygdala is the principal brain region identified with these three tests, and further research must identify the neural circuits underlying this form of anxiety.
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Affiliation(s)
| | - Catherine Strazielle
- , Laboratoire 'Stress, Immunité, Pathogènes' EA 7300 and Service de Microscopie Electronique, Faculté de Médecine
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Adank DN, Lunzer MM, Lensing CJ, Wilber SL, Gancarz AM, Haskell-Luevano C. Comparative in Vivo Investigation of Intrathecal and Intracerebroventricular Administration with Melanocortin Ligands MTII and AGRP into Mice. ACS Chem Neurosci 2018; 9:320-327. [PMID: 28968061 PMCID: PMC5821609 DOI: 10.1021/acschemneuro.7b00330] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Central administration of melanocortin ligands has been used as a critical technique to study energy homeostasis. While intracerebroventricular (ICV) injection is the most commonly used method during these investigations, intrathecal (IT) injection can be equally efficacious for the central delivery of ligands. Importantly, intrathecal administration can optimize exploration of melanocortin receptors in the spinal cord. Herein, we investigate comparative IT and ICV administration of two melanocortin ligands, the synthetic MTII (Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH2) MC4R agonist and agouti-related peptide [AGRP(87-132)] MC4R inverse agonist/antagonist, on the same batch of age-matched mice in TSE metabolic cages undergoing a nocturnal satiated paradigm. To our knowledge, this is the first study to test how central administration of these ligands directly to the spinal cord affects energy homeostasis. Results showed, as expected, that MTII IT administration caused a decrease in food and water intake and an overall negative energy balance without affecting activity. As anticipated, IT administration of AGRP caused weight gain, increase of food/water intake, and increase respiratory exchange ratio (RER). Unexpectantly, the prolonged activity of AGRP was notably shorter (2 days) compared to mice given ICV injections of the same concentrations in previous studies (7 days or more).1-4 It appears that IT administration results in a more sensitive response that may be a good approach for testing synthetic compound potency values ranging in nanomolar to high micromolar in vitro EC50 values. Indeed, our investigation reveals that the spine influences a different melanocortin response compared to the brain for the AGRP ligand. This study indicates that IT administration can be a useful technique for future metabolic studies using melanocortin ligands and highlights the importance of exploring the role of melanocortin receptors in the spinal cord.
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MESH Headings
- Agouti-Related Protein/administration & dosage
- Animals
- Body Weight/drug effects
- Catheters, Indwelling
- Cross-Over Studies
- Eating/drug effects
- Homeostasis/drug effects
- Injections, Intraventricular
- Injections, Spinal
- Male
- Mice, 129 Strain
- Mice, Inbred C57BL
- Peptide Fragments/administration & dosage
- Receptor, Melanocortin, Type 4/agonists
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/metabolism
- Time Factors
- alpha-MSH/administration & dosage
- alpha-MSH/analogs & derivatives
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Affiliation(s)
- Danielle N. Adank
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Mary M. Lunzer
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Cody J. Lensing
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Stacey L. Wilber
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Amy M. Gancarz
- Department of Psychology, California State University Bakersfield, Bakersfield, CA 93311, United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
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18
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Mani BK, Castorena CM, Osborne-Lawrence S, Vijayaraghavan P, Metzger NP, Elmquist JK, Zigman JM. Ghrelin mediates exercise endurance and the feeding response post-exercise. Mol Metab 2018; 9:114-130. [PMID: 29396372 PMCID: PMC5870098 DOI: 10.1016/j.molmet.2018.01.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/09/2018] [Accepted: 01/12/2018] [Indexed: 12/19/2022] Open
Abstract
Objective Exercise training has several well-established health benefits, including many related to body weight, appetite control, and blood glucose homeostasis. However, the molecular mechanisms and, in particular, the hormonal systems that mediate and integrate these beneficial effects are poorly understood. In the current study, we aimed to investigate the role of the hormone ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR; ghrelin receptor), in mediating the effects of exercise on food intake and blood glucose following exercise as well as in regulating exercise endurance capacity. Methods We used two mouse models of treadmill running to characterize the changes in plasma ghrelin with exercise. We also assessed the role of the ghrelin system to influence food intake and blood glucose after exercise, exercise endurance, and parameters potentially linked to responses to exercise. Mice lacking GHSRs (GHSR-null mice) and wild-type littermates were studied. Results An acute bout of exercise transiently elevated plasma acyl-ghrelin. Without the action of this increased ghrelin on GHSRs (as in GHSR-null mice), high intensity interval exercise markedly reduced food intake compared to control mice. The effect of exercise to acutely raise blood glucose remained unmodified in GHSR-null mice. Exercise-induced increases in plasma ghrelin positively correlated with endurance capacity, and time to exhaustion was reduced in GHSR-null mice as compared to wild-type littermates. In an effort to mechanistically explain their reduced exercise endurance, exercised GHSR-null mice exhibited an abrogated sympathoadrenal response, lower overall insulin-like growth factor-1 levels, and altered glycogen utilization. Conclusions Exercise transiently increases plasma ghrelin. GHSR-null mice exhibit decreased food intake following high intensity interval exercise and decreased endurance when submitted to an exercise endurance protocol. These data suggest that an intact ghrelin system limits the capacity of exercise to restrict food intake following exercise, although it enhances exercise endurance. High intensity exercise transiently increases plasma ghrelin. Without ghrelin action on its receptors (growth hormone secretagogue receptors), exercise markedly reduces food intake. An intact ghrelin system enhances exercise endurance.
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Affiliation(s)
- Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carlos M Castorena
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sherri Osborne-Lawrence
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prasanna Vijayaraghavan
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nathan P Metzger
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Barington M, Brorson MM, Hofman-Bang J, Rasmussen ÅK, Holst B, Feldt-Rasmussen U. Ghrelin-mediated inhibition of the TSH-stimulated function of differentiated human thyrocytes ex vivo. PLoS One 2017; 12:e0184992. [PMID: 28931076 PMCID: PMC5607171 DOI: 10.1371/journal.pone.0184992] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/04/2017] [Indexed: 02/05/2023] Open
Abstract
Ghrelin is a peptide hormone produced mainly in the gastrointestinal tract known to regulate several physiological functions including gut motility, adipose tissue accumulation and hunger sensation leading to increased bodyweight. Studies have found a correlation between the plasma levels of thyroid hormones and ghrelin, but an effect of ghrelin on the human thyroid has never been investigated even though ghrelin receptors are present in the thyroid. The present study shows a ghrelin-induced decrease in the thyroid-stimulating hormone (TSH)-induced production of thyroglobulin and mRNA expression of thyroperoxidase in a primary culture of human thyroid cells obtained from paranodular tissue. Accordingly, a trend was noted for an inhibition of TSH-stimulated expression of the sodium-iodine symporter and the TSH-receptor. Thus, this study suggests an effect of ghrelin on human thyrocytes and thereby emphasizes the relevance of examining whether ghrelin also influences the metabolic homeostasis through altered thyroid hormone production.
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Affiliation(s)
- Maria Barington
- Department of Medical Endocrinology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Marianne Møller Brorson
- Department of Medical Endocrinology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Jacob Hofman-Bang
- Department of Medical Endocrinology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Åse Krogh Rasmussen
- Department of Medical Endocrinology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Birgitte Holst
- Institute of Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Ulla Feldt-Rasmussen
- Department of Medical Endocrinology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
- * E-mail:
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20
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Influence of water salinity on genes implicated in somatic growth, lipid metabolism and food intake in Pejerrey ( Odontesthes bonariensis ). Comp Biochem Physiol B Biochem Mol Biol 2017; 210:29-38. [DOI: 10.1016/j.cbpb.2017.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/06/2017] [Accepted: 05/21/2017] [Indexed: 01/06/2023]
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Abstract
High fructose corn syrup (HFCS) is widely used as sweetener in processed foods and soft drinks in the United States, largely substituting sucrose (SUC). The orexigenic hormone ghrelin promotes obesity and insulin resistance; ghrelin responds differently to HFCS and SUC ingestion. Here we investigated the roles of ghrelin in HFCS- and SUC-induced adiposity and insulin resistance. To mimic soft drinks, 10-week-old male wild-type (WT) and ghrelin knockout (Ghrelin-/-) mice were subjected to ad lib. regular chow diet supplemented with either water (RD), 8% HFCS (HFCS), or 10% sucrose (SUC). We found that SUC-feeding induced more robust increases in body weight and body fat than HFCS-feeding. Comparing to SUC-fed mice, HFCS-fed mice showed lower body weight but higher circulating glucose and insulin levels. Interestingly, we also found that ghrelin deletion exacerbates HFCS-induced adiposity and inflammation in adipose tissues, as well as whole-body insulin resistance. Our findings suggest that HFCS and SUC have differential effects on lipid metabolism: while sucrose promotes obesogenesis, HFCS primarily enhances inflammation and insulin resistance, and ghrelin confers protective effects for these metabolic dysfunctions.
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22
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Moretto TL, Benfato ID, de Carvalho FP, Barthichoto M, Le Sueur-Maluf L, de Oliveira CAM. The effects of calorie-matched high-fat diet consumption on spontaneous physical activity and development of obesity. Life Sci 2017; 179:30-36. [DOI: 10.1016/j.lfs.2017.04.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/15/2017] [Accepted: 04/24/2017] [Indexed: 12/12/2022]
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23
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Shainer I, Buchshtab A, Hawkins TA, Wilson SW, Cone RD, Gothilf Y. Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish. Sci Rep 2017; 7:44777. [PMID: 28317906 PMCID: PMC5357965 DOI: 10.1038/srep44777] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/13/2017] [Indexed: 11/21/2022] Open
Abstract
The neuropeptide agouti-related protein (AgRP) is expressed in the arcuate nucleus of the mammalian hypothalamus and plays a key role in regulating food consumption and energy homeostasis. Fish express two agrp genes in the brain: agrp1, considered functionally homologous with the mammalian AgRP, and agrp2. The role of agrp2 and its relationship to agrp1 are not fully understood. Utilizing BAC transgenesis, we generated transgenic zebrafish in which agrp1- and agrp2-expressing cells can be visualized and manipulated. By characterizing these transgenic lines, we showed that agrp1-expressing neurons are located in the ventral periventricular hypothalamus (the equivalent of the mammalian arcuate nucleus), projecting throughout the hypothalamus and towards the preoptic area. The agrp2 gene was expressed in the pineal gland in a previously uncharacterized subgroup of cells. Additionally, agrp2 was expressed in a small group of neurons in the preoptic area that project directly towards the pituitary and form an interface with the pituitary vasculature, suggesting that preoptic AgRP2 neurons are hypophysiotropic. We showed that direct synaptic connection can exist between AgRP1 and AgRP2 neurons in the hypothalamus, suggesting communication and coordination between AgRP1 and AgRP2 neurons and, therefore, probably also between the processes they regulate.
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Affiliation(s)
- Inbal Shainer
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Adi Buchshtab
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Thomas A. Hawkins
- The Department of Cell and Developmental Biology, Faculty of Life Sciences, University College London, London, UK
| | - Stephen W. Wilson
- The Department of Cell and Developmental Biology, Faculty of Life Sciences, University College London, London, UK
| | - Roger D. Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Yoav Gothilf
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
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Lockie SH, McAuley CV, Rawlinson S, Guiney N, Andrews ZB. Food Seeking in a Risky Environment: A Method for Evaluating Risk and Reward Value in Food Seeking and Consumption in Mice. Front Neurosci 2017; 11:24. [PMID: 28194094 PMCID: PMC5276994 DOI: 10.3389/fnins.2017.00024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/12/2017] [Indexed: 11/13/2022] Open
Abstract
Most studies that measure food intake in mice do so in the home cage environment. This necessarily means that mice do not engage in food seeking before consumption, a behavior that is ubiquitous in free-living animals. We modified and validated several commonly used anxiety tests to include a palatable food reward within the anxiogenic zone. This allowed us to assess risk-taking behavior in food seeking in mice in response to different metabolic stimuli. We modified the open field test and the light/dark box by placing palatable peanut butter chips within a designated food zone inside the anxiogenic zone of each apparatus. We then assessed parameters of the interaction with the food reward. Fasted mice or mice treated with ghrelin showed increased consumption and increased time spent in the food zone immediately around the food reward compared to ad libitum fed mice or mice treated with saline. However, fasted mice treated with IP glucose before exposure to the behavioral arena showed reduced time in the food zone compared to fasted controls, indicating that acute metabolic signals can modify the assessment of safety in food seeking in a risky environment. The tests described in this study will be useful in assessing risk processing and incentive salience of food reward, which are intrinsic components of food acquisition outside of the laboratory environment, in a range of genetic and pharmacological models.
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Affiliation(s)
- Sarah H Lockie
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University Clayton, VIC, Australia
| | - Clare V McAuley
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University Clayton, VIC, Australia
| | - Sasha Rawlinson
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University Clayton, VIC, Australia
| | - Natalie Guiney
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University Clayton, VIC, Australia
| | - Zane B Andrews
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University Clayton, VIC, Australia
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25
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Bertucci JI, Blanco AM, Canosa LF, Unniappan S. Glucose, amino acids and fatty acids directly regulate ghrelin and NUCB2/nesfatin-1 in the intestine and hepatopancreas of goldfish (Carassius auratus) in vitro. Comp Biochem Physiol A Mol Integr Physiol 2017; 206:24-35. [PMID: 28089858 DOI: 10.1016/j.cbpa.2017.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 02/07/2023]
Abstract
Ghrelin and nesfatin-1 are two peptidyl hormones primarily involved in food intake regulation. We previously reported that the amount of dietary carbohydrates, protein and lipids modulates the expression of these peptides in goldfish in vivo. In the present work, we aimed to characterize the effects of single nutrients on ghrelin and nesfatin-1 in the intestine and hepatopancreas. First, immunolocalization of ghrelin and NUCB2/nesfatin-1 in goldfish hepatopancreas cells was studied by immunohistochemistry. Second, the effects of 2 and 4hour-long exposures of cultured intestine and hepatopancreas sections to glucose, l-tryptophan, oleic acid, linolenic acid (LNA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on ghrelin and nesfatin-1 gene and protein expression were studied. Co-localization of ghrelin and NUCB2/nesfatin-1 in the cytoplasm of goldfish hepatocytes was found. Exposure to glucose led to an upregulation of preproghrelin and a downregulation of nucb2/nesfatin-1 in the intestine. l-Tryptophan mainly decreased the expression of both peptides in the intestine and hepatopancreas. Fatty acids, in general, downregulated NUCB2/nesfatin-1 in the intestine, but only the longer and highly unsaturated fatty acids inhibited preproghrelin. EPA exposure led to a decrease in preproghrelin, and an increase in nucb2/nesfatin-1 expression in hepatopancreas after 2h. These results show that macronutrients exert a dose- and time-dependent, direct regulation of ghrelin and nesfatin-1 in the intestine and hepatopancreas, and suggest a role for these hormones in the digestive process and nutrient metabolism.
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Affiliation(s)
- Juan Ignacio Bertucci
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Av. Intendente Marino Km 8.2, CC 164 (7130) Chascomús, Prov. de Buenos Aires, Argentina.
| | - Ayelén Melisa Blanco
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, Calle José Antonio Nováis 12, 28040 Madrid, Spain.
| | - Luis Fabián Canosa
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Av. Intendente Marino Km 8.2, CC 164 (7130) Chascomús, Prov. de Buenos Aires, Argentina.
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada.
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Beck WR, Scariot PPM, Carmo SSD, Manchado-Gobatto FB, Gobatto CA. Metabolic profile and spontaneous physical activity modulation under short-term food restriction in young rats. MOTRIZ: REVISTA DE EDUCACAO FISICA 2017. [DOI: 10.1590/s1980-6574201700si0013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Rognmo K, Sivertsen B, Eberhard-Gran M. Self-reported short sleep duration and insomnia symptoms as predictors of post-pregnancy weight change: Results from a cohort study. ACTA ACUST UNITED AC 2016; 12:465-474. [PMID: 27634975 DOI: 10.1177/1745505716668871] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/27/2016] [Accepted: 08/09/2016] [Indexed: 11/17/2022]
Abstract
This study aims to investigate whether change in sleep duration and insomnia symptoms in the postpartum period is related to change in body mass index from before to 2 years after pregnancy. This study is based on self-report data from a Norwegian cohort, the AHUS Birth Cohort Study. Data were collected at 8 weeks (T1) and 2 years (T2) postpartum. Data from 812 women were analyzed. The results showed that only women with symptoms of insomnia at both T1 and T2 (persistent symptoms) had a greater increase in body mass index compared to women with no insomnia symptoms at T1 or T2.The results indicate that persistent insomnia symptoms are related to a greater increase in body mass index.
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Affiliation(s)
- Kamilla Rognmo
- Department of Psychology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Børge Sivertsen
- Division of Mental Health, Norwegian Institute of Public Health, Oslo, Norway.,Uni Research Health, Bergen, Norway.,Department of Psychiatry, Helse Fonna HF, Haugesund, Norway
| | - Malin Eberhard-Gran
- Division of Mental Health, Norwegian Institute of Public Health, Oslo, Norway.,Health Services Research Center, Akershus University Hospital, Lørenskog, Norway.,Institute of Clinical Medicine, University of Oslo, Lørenskog, Norway
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Lee JH, Lin L, Xu P, Saito K, Wei Q, Meadows AG, Bongmba OYN, Pradhan G, Zheng H, Xu Y, Sun Y. Neuronal Deletion of Ghrelin Receptor Almost Completely Prevents Diet-Induced Obesity. Diabetes 2016; 65:2169-78. [PMID: 27207529 PMCID: PMC4955988 DOI: 10.2337/db15-1587] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/28/2016] [Indexed: 12/17/2022]
Abstract
Ghrelin signaling has major effects on energy and glucose homeostasis, but it is unknown whether ghrelin's functions are centrally and/or peripherally mediated. The ghrelin receptor, growth hormone secretagogue receptor (GHS-R), is highly expressed in the brain and detectable in some peripheral tissues. To understand the roles of neuronal GHS-R, we generated a mouse line where Ghsr gene is deleted in all neurons using synapsin 1 (Syn1)-Cre driver. Our data showed that neuronal Ghsr deletion abolishes ghrelin-induced spontaneous food intake but has no effect on total energy intake. Remarkably, neuronal Ghsr deletion almost completely prevented diet-induced obesity (DIO) and significantly improved insulin sensitivity. The neuronal Ghsr-deleted mice also showed improved metabolic flexibility, indicative of better adaption to different fuels. In addition, gene expression analysis suggested that hypothalamus and/or midbrain might be the sites that mediate the effects of GHS-R in thermogenesis and physical activity, respectively. Collectively, our results indicate that neuronal GHS-R is a crucial regulator of energy metabolism and a key mediator of DIO. Neuronal Ghsr deletion protects against DIO by regulating energy expenditure, not by energy intake. These novel findings suggest that suppressing central ghrelin signaling may serve as a unique antiobesity strategy.
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Affiliation(s)
- Jong Han Lee
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Ligen Lin
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Pingwen Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Kenji Saito
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Qiong Wei
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX Division of Endocrinology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, China
| | - Adelina G Meadows
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Odelia Y N Bongmba
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Geetali Pradhan
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Yuxiang Sun
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX Huffington Center on Aging, Baylor College of Medicine, Houston, TX Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX Department of Nutrition and Food Science, Texas A&M University, College Station, TX
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Arnoldussen IA, Zerbi V, Wiesmann M, Noordman RH, Bolijn S, Mutsaers MP, Dederen PJ, Kleemann R, Kooistra T, van Tol EA, Gross G, Schoemaker MH, Heerschap A, Wielinga PY, Kiliaan AJ. Early intake of long-chain polyunsaturated fatty acids preserves brain structure and function in diet-induced obesity. J Nutr Biochem 2016; 30:177-88. [DOI: 10.1016/j.jnutbio.2015.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/13/2015] [Accepted: 12/16/2015] [Indexed: 12/28/2022]
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Röder PV, Wu B, Liu Y, Han W. Pancreatic regulation of glucose homeostasis. Exp Mol Med 2016; 48:e219. [PMID: 26964835 PMCID: PMC4892884 DOI: 10.1038/emm.2016.6] [Citation(s) in RCA: 448] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/03/2015] [Accepted: 12/06/2015] [Indexed: 12/11/2022] Open
Abstract
In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed.
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Affiliation(s)
- Pia V Röder
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore. E-mail: or
| | - Bingbing Wu
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
| | - Yixian Liu
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
| | - Weiping Han
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore. E-mail: or
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Bertucci JI, Blanco AM, Canosa LF, Unniappan S. Estradiol and testosterone modulate the tissue-specific expression of ghrelin, ghs-r, goat and nucb2 in goldfish. Gen Comp Endocrinol 2016; 228:17-23. [PMID: 26773340 DOI: 10.1016/j.ygcen.2016.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 02/08/2023]
Abstract
Ghrelin, and nesfatin-1 (encoded by nucleobindin2/nucb2) are two metabolic peptides with multiple biological effects in vertebrates. While sex steroids are known to regulate endogenous ghrelin and NUCB2 in mammals, such actions by steroids in fish remain unknown. This study aimed to determine whether estradiol (E2) and testosterone (T) affects the expression of preproghrelin, ghrelin/growth hormone secretagogue receptor (GHS-R), ghrelin O-acyl transferase (GOAT) and NUCB2 in goldfish (Carassius auratus). First, a dose-response assay was performed in which fish were intraperitoneally (ip) implanted with pellets containing 25, 50 or 100 μg/g body weight (BW) of E2 or T. It was found that sex steroids (100 μg/g BW) administered for 2.5 days achieved the highest E2 or T in circulation. In a second experiment, fish were ip implanted with pellets containing 100 μg/g BW of E2, T or without hormone (control). RT-qPCR analyses at 2.5 days post-administration show that gut preproghrelin and GOAT expression was upregulated by both E2 and T treatments, while the same effect was observed for GHS-R only in the pituitary. Both treatments also reduced hypothalamic preproghrelin mRNA expression. NUCB2 expression was increased in the forebrain of T treated group and reduced in the gut and pituitary under both treatments. These results show for the first time a modulation of preproghrelin and nucb2/nesfatin-1 by sex steroids in fish. The interaction between sex steroids and genes implicated in both metabolism and reproduction might help meeting the reproduction dependent energy demands in fish.
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Affiliation(s)
- Juan Ignacio Bertucci
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), Intendente Marino Km 8.2, B7130IWA Chascomús, Buenos Aires, Argentina CC 164 (7130), Argentina.
| | - Ayelén Melisa Blanco
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - Luis Fabián Canosa
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), Intendente Marino Km 8.2, B7130IWA Chascomús, Buenos Aires, Argentina CC 164 (7130), Argentina.
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, Saskatoon, Saskatchewan S7N 5B4, Canada.
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Ruginsk SG, Vechiato FMV, Uchoa ET, Elias LLK, Antunes-Rodrigues J. Type 1 cannabinoid receptor modulates water deprivation-induced homeostatic responses. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1358-68. [PMID: 26468265 DOI: 10.1152/ajpregu.00536.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 10/14/2015] [Indexed: 01/02/2023]
Abstract
The present study investigated the type 1 cannabinoid receptor (CB1R) as a potential candidate to mediate the homeostatic responses triggered by 24 h of water deprivation, which constitutes primarily a hydroelectrolytic challenge and also significantly impacts energy homeostasis. The present results demonstrated for the first time that CB1R mRNA expression is increased in the hypothalamus of water-deprived (WD) rats. Furthermore, the administration of ACEA, a CB1R selective agonist, potentiated WD-induced dipsogenic effect, whereas AM251, a CB1R antagonist, attenuated not only water but also salt intake in response to WD. In parallel with the modulation of thirst and salt appetite, we confirmed that CB1Rs are essential for the development of appropriated neuroendocrine responses. Although the administration of ACEA or AM251 did not produce any effects on WD-induced arginine vasopressin (AVP) secretion, oxytocin (OXT) plasma concentrations were significantly decreased in WD rats treated with ACEA. At the genomic level, ACEA significantly decreased AVP and OXT mRNA expression in the hypothalamus of WD rats, whereas AM251 potentiated both basal and WD-induced stimulatory effects on the transcription of AVP and OXT genes. In addition, we showed that water deprivation alone upregulated proopiomelanocortin, Agouti-related peptide, melanin-concentrating hormone, and orexin A mRNA levels in the hypothalamus, and that CB1Rs regulate main central peptidergic pathways controlling food intake, being that most of these effects were also significantly influenced by the hydration status. In conclusion, the present study demonstrated that CB1Rs participate in the homeostatic responses regulating fluid balance and energy homeostasis during water deprivation.
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Affiliation(s)
- Silvia G Ruginsk
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil; Department of Physiological Sciences, Biomedical Sciences Institute, Federal University of Alfenas, Alfenas, Minas Gerais, Brazil; and
| | - Fernanda M V Vechiato
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Ernane T Uchoa
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil; Department of Physiological Sciences, State University of Londrina, Londrina, Parana, Brazil
| | - Lucila L K Elias
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Jose Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil;
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Diet-induced obesity causes ghrelin resistance in reward processing tasks. Psychoneuroendocrinology 2015; 62:114-20. [PMID: 26292268 DOI: 10.1016/j.psyneuen.2015.08.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/07/2015] [Accepted: 08/07/2015] [Indexed: 11/21/2022]
Abstract
Diet-induced obesity (DIO) causes ghrelin resistance in hypothalamic Agouti-related peptide (AgRP) neurons. However, ghrelin promotes feeding through actions at both the hypothalamus and mesolimbic dopamine reward pathways. Therefore, we hypothesized that DIO would also establish ghrelin resistance in the ventral tegmental area (VTA), a major site of dopaminergic cell bodies important in reward processing. We observed reduced sucrose and saccharin consumption in Ghrelin KO vs Ghrelin WT mice. Moreover, DIO reduced saccharin consumption relative to chow-fed controls. These data suggest that the deletion of ghrelin and high fat diet both cause anhedonia. To assess if these are causally related, we tested whether DIO caused ghrelin resistance in a classic model of drug reward, conditioned place preference (CPP). Chow or high fat diet (HFD) mice were conditioned with ghrelin (1mg/kg in 10ml/kg ip) in the presence or absence of food in the conditioning chamber. We observed a CPP to ghrelin in chow-fed mice but not in HFD-fed mice. HFD-fed mice still showed a CPP for cocaine (20mg/kg), indicating that they maintained the ability to develop conditioned behaviour. The absence of food availability during ghrelin conditioning sessions induced a conditioned place aversion, an effect that was still present in both chow and HFD mice. Bilateral intra-VTA ghrelin injection (0.33μg/μl in 0.5μl) robustly increased feeding in both chow-fed and high fat diet (HFD)-fed mice; however, this was correlated with body weight only in the chow-fed mice. Our results suggest that DIO causes ghrelin resistance albeit not directly in the VTA. We suggest there is impaired ghrelin sensitivity in upstream pathways regulating reward pathways, highlighting a functional role for ghrelin linking appropriate metabolic sensing with reward processing.
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Gumus Balikcioglu P, Balikcioglu M, Muehlbauer MJ, Purnell JQ, Broadhurst D, Freemark M, Haqq AM. Macronutrient Regulation of Ghrelin and Peptide YY in Pediatric Obesity and Prader-Willi Syndrome. J Clin Endocrinol Metab 2015; 100:3822-31. [PMID: 26259133 PMCID: PMC5399503 DOI: 10.1210/jc.2015-2503] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The roles of macronutrients and GH in the regulation of food intake in pediatric obesity and Prader-Willi Syndrome (PWS) are poorly understood. OBJECTIVE We compared effects of high-carbohydrate (HC) and high-fat (HF) meals and GH therapy on ghrelin, insulin, peptide YY (PYY), and insulin sensitivity in children with PWS and body mass index (BMI) -matched obese controls (OCs). METHODS In a randomized, crossover study, 14 PWS (median, 11.35 y; BMI z score [BMI-z], 2.15) and 14 OCs (median, 11.97 y; BMI-z, 2.35) received isocaloric breakfast meals (HC or HF) on separate days. Blood samples were drawn at baseline and every 30 minutes for 4 hours. Mixed linear models were adjusted for age, sex, and BMI-z. RESULTS Relative to OCs, children with PWS had lower fasting insulin and higher fasting ghrelin and ghrelin/PYY. Ghrelin levels were higher in PWS across all postprandial time points (P < .0001). Carbohydrate was more potent than fat in suppressing ghrelin levels in PWS (P = .028); HC and HF were equipotent in OCs but less potent than in PWS (P = .011). The increase in PYY following HF was attenuated in PWS (P = .037); thus, postprandial ghrelin/PYY remained higher throughout. A lesser increase in insulin and lesser decrease in ghrelin were observed in GH-treated PWS patients than in untreated patients; PYY responses were comparable. CONCLUSION Children with PWS have fasting and postprandial hyperghrelinemia and an attenuated PYY response to fat, yielding a high ghrelin/PYY ratio. GH therapy in PWS is associated with increased insulin sensitivity and lesser postprandial suppression of ghrelin. The ratio Ghrelin/PYY may be a novel marker of orexigenic drive.
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Affiliation(s)
- Pinar Gumus Balikcioglu
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - Metin Balikcioglu
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - Michael J Muehlbauer
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - Jonathan Q Purnell
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - David Broadhurst
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - Michael Freemark
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
| | - Andrea M Haqq
- Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada
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Ghrelin's Role in the Hypothalamic-Pituitary-Adrenal Axis Stress Response: Implications for Mood Disorders. Biol Psychiatry 2015; 78:19-27. [PMID: 25534754 DOI: 10.1016/j.biopsych.2014.10.021] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 09/26/2014] [Accepted: 10/15/2014] [Indexed: 12/24/2022]
Abstract
Ghrelin is a stomach hormone normally associated with feeding behavior and energy homeostasis. Recent studies highlight that ghrelin targets the brain to regulate a diverse number of functions, including learning, memory, motivation, stress responses, anxiety, and mood. In this review, we discuss recent animal and human studies showing that ghrelin regulates the hypothalamic-pituitary-adrenal axis and affects anxiety and mood disorders, such as depression and fear. We address the neural sites of action through which ghrelin regulates the hypothalamic-pituitary-adrenal axis and associated stress-induced behaviors, including the centrally projecting Edinger-Westphal nucleus, the hippocampus, amygdala, locus coeruleus, and the ventral tegmental area. Stressors modulate many behaviors associated with motivation, fear, anxiety, depression, and appetite; therefore, we assess the potential role for ghrelin as a stress feedback signal that regulates these associated behaviors. Finally, we briefly discuss important areas for future research that will help us move closer to potential ghrelin-based therapies to treat stress responses and related disorders.
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Intracerebroventricular administration of leptin increase physical activity but has no effect on thermogenesis in cold-acclimated rats. Sci Rep 2015; 5:11189. [PMID: 26053156 PMCID: PMC4459185 DOI: 10.1038/srep11189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 04/17/2015] [Indexed: 12/03/2022] Open
Abstract
Most small homotherms display low leptin level in response to chronic cold exposure. Cold-induced hypoleptinemia was proved to induce hyperphagia. However, it is still not clear whether hypoleptinemia regulates energy expenditure in cold condition. We try to answer this question in chronic cold-acclimated rats. Results showed that 5-day intracerebroventricular(ICV) infusion of leptin (5 μg/day) had no effects on basal and adaptive thermogenesis and uncoupling protein 1 expression. Physical activity was increased by leptin treatment. We further determined whether ghrelin could reverse the increasing effect of leptin on physical activity. Coadministration of ghrelin (1.2 μg/day) completely reversed the effect of leptin on physical activity. Collectively, this study indicated the regulation of leptin on energy expenditure during cold acclimation may be mainly mediated by physical activity but not by thermogenesis. Our study outlined behavioral role of leptin during the adaptation to cold, which adds some new knowledge to promote our understanding of cold-induced metabolic adaptation.
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Ratner C, Madsen AN, Kristensen LV, Skov LJ, Pedersen KS, Mortensen OH, Knudsen GM, Raun K, Holst B. Impaired oxidative capacity due to decreased CPT1b levels as a contributing factor to fat accumulation in obesity. Am J Physiol Regul Integr Comp Physiol 2015; 308:R973-82. [DOI: 10.1152/ajpregu.00219.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 03/09/2015] [Indexed: 02/05/2023]
Abstract
To characterize mechanisms responsible for fat accumulation we used a selectively bred obesity-prone (OP) and obesity-resistant (OR) rat model where the rats were fed a Western diet for 76 days. Body composition was assessed by magnetic resonance imaging scans, and as expected, the OP rats developed a higher degree of fat accumulation compared with OR rats. Indirect calorimetry showed that the OP rats had higher respiratory exchange ratio (RER) compared with OR rats, indicating an impaired ability to oxidize fat. The OP rats had lower expression of carnitine palmitoyltransferase 1b in intra-abdominal fat, and higher expression of stearoyl-CoA desaturase 1 in subcutaneous fat compared with OR rats, which could explain the higher fat accumulation and RER values. Basal metabolic parameters were also examined in juvenile OP and OR rats before and during the introduction of the Western diet. Juvenile OP rats likewise had higher RER values, indicating that this trait may be a primary and contributing factor to their obese phenotype. When the adult obese rats were exposed to the orexigenic and adipogenic hormone ghrelin, we observed increased RER values in both OP and OR rats, while OR rats were more sensitive to the orexigenic effects of ghrelin as well as ghrelin-induced attenuation of activity and energy expenditure. Thus increased fat accumulation characterizing obesity may be caused by impaired oxidative capacity due to decreased carnitine palmitoyltransferase 1b levels in the white adipose tissue, whereas ghrelin sensitivity did not seem to be a contributing factor.
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Affiliation(s)
- Cecilia Ratner
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Section for Metabolic Receptology and Enteroendocrinology, The Novo Nordisk Foundation Center for basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Nygaard Madsen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Section for Metabolic Receptology and Enteroendocrinology, The Novo Nordisk Foundation Center for basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Line Vildbrad Kristensen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Section for Metabolic Receptology and Enteroendocrinology, The Novo Nordisk Foundation Center for basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Louise Julie Skov
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Section for Metabolic Receptology and Enteroendocrinology, The Novo Nordisk Foundation Center for basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Seide Pedersen
- Department of Biomedical Sciences, Cellular and Metabolic Research Section, Symbion, Copenhagen, Denmark
| | - Ole Hartvig Mortensen
- Department of Biomedical Sciences, Cellular and Metabolic Research Section, Symbion, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; and
| | - Kirsten Raun
- Novo Nordisk Diabetes Research Unit, Novo Nordisk A/S, Maaloev, Denmark
| | - Birgitte Holst
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Section for Metabolic Receptology and Enteroendocrinology, The Novo Nordisk Foundation Center for basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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Lizarbe B, López-Larrubia P, Cerdán S. fDWI Evaluation of Hypothalamic Appetite Regulation Pathways in Mice Genetically Deficient in Leptin or Neuropeptide Y. Neurochem Res 2015; 40:2628-38. [DOI: 10.1007/s11064-015-1596-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/15/2015] [Accepted: 04/30/2015] [Indexed: 12/30/2022]
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Reis WL, Yi CX, Gao Y, Tschöp MH, Stern JE. Brain innate immunity regulates hypothalamic arcuate neuronal activity and feeding behavior. Endocrinology 2015; 156:1303-15. [PMID: 25646713 PMCID: PMC4399317 DOI: 10.1210/en.2014-1849] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hypothalamic inflammation, involving microglia activation in the arcuate nucleus (ARC), is proposed as a novel underlying mechanism in obesity, insulin and leptin resistance. However, whether activated microglia affects ARC neuronal activity, and consequently basal and hormonal-induced food intake, is unknown. We show that lipopolysaccharide, an agonist of the toll-like receptor-4 (TLR4), which we found to be expressed in ARC microglia, inhibited the firing activity of the majority of orexigenic agouti gene-related protein/neuropeptide Y neurons, whereas it increased the activity of the majority of anorexigenic proopiomelanocortin neurons. Lipopolysaccharide effects in agouti gene-related protein/neuropeptide Y (but not in proopiomelanocortin) neurons were occluded by inhibiting microglia function or by blocking TLR4 receptors. Finally, we report that inhibition of hypothalamic microglia altered basal food intake, also preventing central orexigenic responses to ghrelin. Our studies support a major role for a TLR4-mediated microglia signaling pathway in the control of ARC neuronal activity and feeding behavior.
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Affiliation(s)
- Wagner L Reis
- Department of Physiology (W.L.R., J.E.S.), Medical College of Georgia, Georgia Regents University, Augusta, Georgia 30912; and Helmholtz Diabetes Center (C.-X.Y., Y.G., M.H.T.), Helmholtz Zentrum München and Technische Universität München, Munich 85764, Germany
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Tao YX. Constitutive activity in melanocortin-4 receptor: biased signaling of inverse agonists. ADVANCES IN PHARMACOLOGY 2015; 70:135-54. [PMID: 24931195 DOI: 10.1016/b978-0-12-417197-8.00005-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The melanocortin-4 receptor (MC4R) is a critical regulator of energy homeostasis, including both energy intake and energy expenditure. It mediates the actions of a number of hormones on energy balance. The endogenous ligands for MC4R include peptide agonists derived from processing of proopiomelanocortin and the antagonist Agouti-related peptide (AgRP). Wild-type MC4R has some basal (constitutive) activity. Naturally occurring and laboratory-generated mutations have been identified, which results in either increased or decreased basal activities. Impaired basal signaling has been suggested to be a cause of dysregulated energy homeostasis and early-onset obesity, although several constitutively active mutations have also been identified from obese patients. AgRP and several small-molecule antagonists have been shown to be inverse agonists in the Gs-cAMP pathway. However, in the extracellular signal-regulated kinase (ERK) 1/2 pathway, we showed that these inverse agonists are potent agonists, demonstrating convincingly that they are biased ligands. We also showed that some mutations that do not cause constitutive activation in the Gs-cAMP pathway cause constitutive activation in the ERK1/2 pathway, suggesting that they are biased receptors. The physiological and potential pathophysiological relevance of the biased constitutive signaling in MC4R and therapeutic potential remain to be investigated.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA.
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Wellman MK, Patterson ZR, MacKay H, Darling JE, Mani BK, Zigman JM, Hougland JL, Abizaid A. Novel Regulator of Acylated Ghrelin, CF801, Reduces Weight Gain, Rebound Feeding after a Fast, and Adiposity in Mice. Front Endocrinol (Lausanne) 2015; 6:144. [PMID: 26441834 PMCID: PMC4585333 DOI: 10.3389/fendo.2015.00144] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/01/2015] [Indexed: 01/04/2023] Open
Abstract
Ghrelin is a 28 amino acid hormonal peptide that is intimately related to the regulation of food intake and body weight. Once secreted, ghrelin binds to the growth hormone secretagogue receptor-1a, the only known receptor for ghrelin and is capable of activating a number of signaling cascades, ultimately resulting in an increase in food intake and adiposity. Because ghrelin has been linked to overeating and the development of obesity, a number of pharmacological interventions have been generated in order to interfere with either the activation of ghrelin or interrupting ghrelin signaling as a means to reducing appetite and decrease weight gain. Here, we present a novel peptide, CF801, capable of reducing circulating acylated ghrelin levels and subsequent body weight gain and adiposity. To this end, we show that IP administration of CF801 is sufficient to reduce circulating plasma acylated ghrelin levels. Acutely, intraperitoneal injections of CF801 resulted in decreased rebound feeding after an overnight fast. When delivered chronically, they decreased weight gain and adiposity without affecting caloric intake. CF801, however, did cause a change in diet preference, decreasing preference for a high-fat diet and increasing preference for regular chow diet. Given the complexity of ghrelin receptor function, we propose that CF801, along with other compounds that regulate ghrelin secretion, may prove to be a beneficial tool in the study of the ghrelin system, and potential targets for ghrelin-based obesity treatments without altering the function of ghrelin receptors.
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Affiliation(s)
| | | | - Harry MacKay
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | | | - Bharath K. Mani
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Internal Medicine, Division of Endocrinology and Metabolism, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M. Zigman
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Internal Medicine, Division of Endocrinology and Metabolism, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
- *Correspondence: Alfonso Abizaid, Department of Neuroscience, Carleton University, 1125 Colonel By Drive, 329 Life Science Research Building, Ottawa, ON K1S 5B6, Canada,
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Cepko LC, Selva JA, Merfeld EB, Fimmel AI, Goldberg SA, Currie PJ. Ghrelin alters the stimulatory effect of cocaine on ethanol intake following mesolimbic or systemic administration. Neuropharmacology 2014; 85:224-31. [DOI: 10.1016/j.neuropharm.2014.05.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 04/29/2014] [Accepted: 05/18/2014] [Indexed: 01/16/2023]
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Nisembaum LG, de Pedro N, Delgado MJ, Isorna E. Crosstalking between the "gut-brain" hormone ghrelin and the circadian system in the goldfish. Effects on clock gene expression and food anticipatory activity. Gen Comp Endocrinol 2014; 205:287-95. [PMID: 24681192 DOI: 10.1016/j.ygcen.2014.03.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 03/14/2014] [Accepted: 03/17/2014] [Indexed: 12/30/2022]
Abstract
Ghrelin is a potent orexigenic signal mainly synthesized in the stomach and foregut of vertebrates. Recent studies in rodents point out that ghrelin could also act as an input for the circadian system and/or as an output of peripheral food-entrainable oscillators, being involved in the food anticipatory activity (FAA). In this study we pursue the possible interaction of ghrelin with the circadian system in a teleost, the goldfish (Carassius auratus). First, we analyzed if ghrelin is able to modulate the core clock functioning by regulating clock gene expression in fish under a light/dark cycle 12L:12D and fed at 10 am. As expected the acute intraperitoneal (IP) injection of goldfish ghrelin (gGRL[1-19], 44 pmol/g bw) induced the expression of hypothalamic orexin. Moreover, ghrelin also induced (∼ 2-fold) some Per clock genes in hypothalamus and liver. This effect was partially counteracted in liver by the ghrelin antagonist ([D-Lys(3)]-GHRP-6, 100 pmol/g bw). Second, we investigated if ghrelin is involved in daily FAA rhythms. With this aim locomotor activity was studied in response to IP injections (5-10 days) of gGRL[1-19] and [D-Lys(3)]-GHRP-6 at the doses above indicated. Ghrelin and saline injected fish showed similar 24h activity patterns. However, ghrelin antagonist treatment abolished the FAA in schedule fed fish under 24h light, suggesting the involvement of the endogenous ghrelin system in this pre-feeding activity. Altogether these results suggest that ghrelin could be acting as an input for the entrainment of the food-entrainable oscillators in the circadian organization of goldfish.
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Affiliation(s)
- Laura G Nisembaum
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Nuria de Pedro
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María J Delgado
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Esther Isorna
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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Novelle MG, Vázquez MJ, Martinello KD, Sanchez-Garrido MA, Tena-Sempere M, Diéguez C. Neonatal events, such as androgenization and postnatal overfeeding, modify the response to ghrelin. Sci Rep 2014; 4:4855. [PMID: 24798184 PMCID: PMC4010967 DOI: 10.1038/srep04855] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/15/2014] [Indexed: 02/03/2023] Open
Abstract
It is currently accepted that ambient, non-genetic factors influence perinatal development and evoke structural and functional changes that may persist throughout life. Overfeeding and androgenization after birth are two of these key factors that could result in “metabolic imprinting” of neuronal circuits early in life and, thereby, increase the body weight homeostatic “set point”, stimulate appetite, and result in obesity. Our aim was to determine the influence of these obesogenic factors on the response to ghrelin. We observed the expected orexigenic effect of ghrelin regardless of the nutritional or hormonal manipulations to which the animals were subjected to at early postnatal development and this effect remained intact at later stages of development. In fact, ghrelin responses increased significantly when the animals were subjected to one of the two manipulations, but not when both were combined. An increased response to ghrelin could explain the obese phenotype displayed by individuals with modified perinatal environment.
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Affiliation(s)
- Marta G Novelle
- 1] Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria (IDIS), 15782 Santiago de Compostela, Spain [2] CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto de Salud Carlos III, Santiago de Compostela, Spain
| | - María J Vázquez
- 1] Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria (IDIS), 15782 Santiago de Compostela, Spain [2] CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto de Salud Carlos III, Santiago de Compostela, Spain
| | - Kátia D Martinello
- 1] Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria (IDIS), 15782 Santiago de Compostela, Spain [2] CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto de Salud Carlos III, Santiago de Compostela, Spain
| | - Miguel A Sanchez-Garrido
- 1] CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto de Salud Carlos III, Santiago de Compostela, Spain [2] Department of Cell Biology, Physiology and Immunology, School of Medicine, University of Córdoba - Instituto Maimónides de Investigación Biomédica (IMIBIC)/Hospital Universitario Reina Sofia, Córdoba, Spain
| | - Manuel Tena-Sempere
- 1] CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto de Salud Carlos III, Santiago de Compostela, Spain [2] Department of Cell Biology, Physiology and Immunology, School of Medicine, University of Córdoba - Instituto Maimónides de Investigación Biomédica (IMIBIC)/Hospital Universitario Reina Sofia, Córdoba, Spain
| | - Carlos Diéguez
- 1] Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria (IDIS), 15782 Santiago de Compostela, Spain [2] CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto de Salud Carlos III, Santiago de Compostela, Spain
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Grayson BE, Schneider KM, Woods SC, Seeley RJ. Improved rodent maternal metabolism but reduced intrauterine growth after vertical sleeve gastrectomy. Sci Transl Med 2014; 5:199ra112. [PMID: 23966301 DOI: 10.1126/scitranslmed.3006505] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Obesity has profound negative consequences on female reproduction as well as on the metabolic health of offspring. Bariatric surgery is the most effective method for sustained weight loss. A critical question is whether bariatric surgery can reverse the deleterious effects of obesity on both female reproduction and subsequent offspring. Vertical sleeve gastrectomy (VSG) is a bariatric procedure rapidly growing in popularity because it provides weight loss and other metabolic benefits that are comparable to those offered by the more complicated Roux-en-Y gastric bypass (RYGB). Female rats rendered obese on a high-fat diet (HFD) underwent either VSG or sham surgery. Like their male counterparts, females had significant metabolic improvements including reduced adiposity and improved glucose tolerance. After VSG, female rats showed a more normal reproductive cycle. Despite these maternal benefits, the offspring of dams receiving VSG were born smaller and lighter than offspring of control dams that underwent sham surgery. When maintained on an HFD after puberty, these adult offspring had a greater propensity to develop glucose intolerance and increased adiposity than the offspring of lean mothers or obese mothers who underwent sham surgery. These data suggest that weight loss alone by obese mothers is not sufficient to reverse the deleterious effects of an HFD and obesity on their offspring.
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Affiliation(s)
- Bernadette E Grayson
- Metabolic Diseases Institute, University of Cincinnati, Cincinnati, OH 45237, USA
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46
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Tinoco AB, Näslund J, Delgado MJ, de Pedro N, Johnsson JI, Jönsson E. Ghrelin increases food intake, swimming activity and growth in juvenile brown trout (Salmo trutta). Physiol Behav 2014; 124:15-22. [DOI: 10.1016/j.physbeh.2013.10.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 10/17/2013] [Accepted: 10/23/2013] [Indexed: 01/05/2023]
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Abstract
Obesity is one of the largest and fastest growing public health problems in the world. Last century social changes have set an obesogenic milieu that calls for micro and macro environment interventions for disease prevention, while treatment is mandatory for individuals already obese. The cornerstone of overweight and obesity treatment is diet and physical exercise. However, many patients find lifestyle modifications difficult to comply and prone to failure in the long-term; therefore many patients consider anti-obesity drugs an important adjuvant if not a better alternative to behavioral approach or obesity surgery. Since the pharmacological options for obesity treatment remain quite limited, this is an exciting research area, with new treatment targets and strategies on the horizon. This review discusses the development of innovative therapeutic agents, focusing in energy homeostasis regulation and the use of molecular vaccines, targeting hormones such as somatostatin, GIP and ghrelin, to reduce body weight.
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Affiliation(s)
- Mariana P Monteiro
- Department of Anatomy; Unit for Multidisciplinary Biomedical Research (UMIB); Institute for Biomedical Sciences Abel Salazar (ICBAS); University of Porto; Porto, Portugal
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Abstract
Over the past 30 years, it has been established that hormones produced by the gut, pancreas, and adipose tissue are key players in the control of body weight. These hormones act through a complex neuroendocrine system, including the hypothalamus, to regulate metabolism and energy homeostasis. In obesity, this homeostatic balance is disrupted, either through alterations in the levels of these hormones or through resistance to their actions. Alterations in gut hormone secretion following gastric bypass surgery are likely to underlie the dramatic and persistent loss of weight following this procedure, as well as the observed amelioration in type 2 diabetes mellitus. Medications based on the gut hormone GLP-1 are currently in clinical use to treat type 2 diabetes mellitus and have been shown to produce weight loss. Further therapies for obesity based on other gut hormones are currently in development.
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Affiliation(s)
- Rebecca Scott
- Division of Diabetes, Endocrinology, Metabolism, Hammersmith Hospital, Imperial College London, London, United Kingdom.
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49
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Stevanovic D, Trajkovic V, Müller-Lühlhoff S, Brandt E, Abplanalp W, Bumke-Vogt C, Liehl B, Wiedmer P, Janjetovic K, Starcevic V, Pfeiffer AFH, Al-Hasani H, Tschöp MH, Castañeda TR. Ghrelin-induced food intake and adiposity depend on central mTORC1/S6K1 signaling. Mol Cell Endocrinol 2013; 381:280-90. [PMID: 23994018 DOI: 10.1016/j.mce.2013.08.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 07/25/2013] [Accepted: 08/19/2013] [Indexed: 10/26/2022]
Abstract
Signaling through the mammalian target of rapamycin complex 1 (mTORC1) and its effectors the S6-kinases (S6K) in the hypothalamus is thought to be involved in nutrient sensing and control of food intake. Given the anatomical proximity of this pathway to circuits for the hormone ghrelin, we investigated the potential role of the mTORC1/S6K pathway in mediating the metabolic effects of ghrelin. We found that ghrelin promoted phosphorylation of S6K1 in the mouse hypothalamic cell line N-41 and in the rat hypothalamus after intracerebroventricular administration. Rapamycin, an inhibitor of mTORC1, suppressed ghrelin-induced phosphorylation of hypothalamic S6K1 and increased food intake and insulin in rats. Chronic peripheral administration of ghrelin induced a significant increase in body weight, fat mass and food efficiency in wild-type and S6K2-knockout but not in S6K1-knockout mice. We therefore propose that ghrelin-induced hyperphagia, adiposity and insulin secretion are controlled by a central nervous system involving the mTORC1/S6K1 pathway.
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Affiliation(s)
- Darko Stevanovic
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam Rehbrücke, Germany; Institute of Physiology, School of Medicine, University of Belgrade, Serbia
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Zhang Q, Deng C, Huang XF. The role of ghrelin signalling in second-generation antipsychotic-induced weight gain. Psychoneuroendocrinology 2013; 38:2423-38. [PMID: 23953928 DOI: 10.1016/j.psyneuen.2013.07.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/17/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
Abstract
Based on clinical and animal studies, this review suggests a tri-phasic effect of second-generation antipsychotics (SGAs) on circulating ghrelin levels: an initial increase exerted by the acute effect of SGAs; followed by a secondary decrease possibly due to the negative feedback from the SGA-induced body weight gain or hyperphagia; and a final re-increase to reach the new equilibrium. Moreover, the results can also vary depending on individual SGAs, other hormonal states, dietary choices, and other confounding factors including medical history, co-treatments, age, gender, and ghrelin measurement techniques. Interestingly, rats treated with olanzapine, an SGA with high weight gain liabilities, are associated with increased hypothalamic ghrelin receptor (GHS-R1a) levels. In addition, expressions of downstream ghrelin signalling parameters at the hypothalamus, including neuropeptide Y (NPY)/agouti-related peptide (AgRP) and proopiomelanocortin (POMC) are also altered under SGA treatments. Thus, understanding the role of ghrelin signalling in antipsychotic drug-induced weight gain should offer potential novel pharmacological targets for tackling the obesity side-effect of SGAs and its associated metabolic syndrome.
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Affiliation(s)
- Qingsheng Zhang
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
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