1
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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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2
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Farokhnia M, Abshire KM, Hammer A, Deschaine SL, Saravanakumar A, Cobbina E, You ZB, Haass-Koffler CL, Lee MR, Akhlaghi F, Leggio L. Neuroendocrine Response to Exogenous Ghrelin Administration, Combined With Alcohol, in Heavy-Drinking Individuals: Findings From a Randomized, Double-Blind, Placebo-Controlled Human Laboratory Study. Int J Neuropsychopharmacol 2021; 24:464-476. [PMID: 33560411 PMCID: PMC8278796 DOI: 10.1093/ijnp/pyab004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/22/2021] [Accepted: 02/02/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Accumulating evidence has established a role for the orexigenic hormone ghrelin in alcohol-seeking behaviors. Accordingly, the ghrelin system may represent a potential pharmacotherapeutic target for alcohol use disorder. Ghrelin modulates several neuroendocrine pathways, such as appetitive, metabolic, and stress-related hormones, which are particularly relevant in the context of alcohol use. The goal of the present study was to provide a comprehensive assessment of neuroendocrine response to exogenous ghrelin administration, combined with alcohol, in heavy-drinking individuals. METHODS This was a randomized, crossover, double-blind, placebo-controlled human laboratory study, which included 2 experimental alcohol administration paradigms: i.v. alcohol self-administration and i.v. alcohol clamp. Each paradigm consisted of 2 counterbalanced sessions of i.v. ghrelin or placebo administration. Repeated blood samples were collected during each session, and peripheral concentrations of the following hormones were measured: leptin, glucagon-like peptide-1, pancreatic polypeptide, gastric inhibitory peptide, insulin, insulin-like growth factor-1, cortisol, prolactin, and aldosterone. RESULTS Despite some statistical differences, findings were consistent across the 2 alcohol administration paradigms: i.v. ghrelin, compared to placebo, increased blood concentrations of glucagon-like peptide-1, pancreatic polypeptide, cortisol, and prolactin, both acutely and during the whole session. Lower levels of leptin and higher levels of aldosterone were also found during the ghrelin vs placebo session. CONCLUSION These findings, gathered from a clinically relevant sample of heavy-drinking individuals with alcohol use disorder, provide a deeper insight into the complex interplay between ghrelin and appetitive, metabolic, and stress-related neuroendocrine pathways in the context of alcohol use.
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Affiliation(s)
- Mehdi Farokhnia
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA,Center on Compulsive Behaviors, National Institutes of Health, Bethesda, Maryland, USA,Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Kelly M Abshire
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
| | - Aaron Hammer
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
| | - Sara L Deschaine
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
| | - Anitha Saravanakumar
- Clinical Pharmacokinetics Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island
| | | | - Zhi-Bing You
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA
| | - Carolina L Haass-Koffler
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA,Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, Rhode Island,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, Rhode Island
| | - Mary R Lee
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
| | - Fatemeh Akhlaghi
- Clinical Pharmacokinetics Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA,Center on Compulsive Behaviors, National Institutes of Health, Bethesda, Maryland, USA,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, Rhode Island,Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA,Division of Addiction Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA,Department of Neuroscience, Georgetown University Medical Center, Washington DC, USA,Correspondence: Lorenzo Leggio, MD, PhD, NIDA and NIAAA, NIH, Biomedical Research Center, 251 Bayview Boulevard, Suite 200, Room 01A844, Baltimore, MD 21224 ()
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3
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Alhambra-Expósito MR, Ibáñez-Costa A, Moreno-Moreno P, Rivero-Cortés E, Vázquez-Borrego MC, Blanco-Acevedo C, Toledano-Delgado Á, Lombardo-Galera MS, Vallejo-Casas JA, Gahete MD, Castaño JP, Gálvez MA, Luque RM. Association between radiological parameters and clinical and molecular characteristics in human somatotropinomas. Sci Rep 2018; 8:6173. [PMID: 29670116 PMCID: PMC5906631 DOI: 10.1038/s41598-018-24260-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 03/09/2018] [Indexed: 02/08/2023] Open
Abstract
Acromegaly is a rare but severe disease, originated in 95% of cases by a growth hormone-secreting adenoma (somatotropinoma) in the pituitary. Magnetic resonance imaging (MRI) is a non-invasive technique used for the diagnosis and prognosis of pituitary tumours. The aim of this study was to determine whether the use of T2-weighted signal intensity at MRI could help to improve the characterisation of somatotropinomas, by analysing its relationship with clinical/molecular features. An observational study was implemented in a cohort of 22 patients (mean age = 42.1 ± 17.2 years; 59% women; 95% size>10 mm). Suprasellar-extended somatotropinomas presented larger diameters vs. non-extended tumours. T2-imaging revealed that 59% of tumours were hyperintense and 41% isointense adenomas, wherein hyperintense were more invasive (according to Knosp-score) than isointense adenomas. A higher proportion of hyperintense somatotropinomas presented extrasellar-growth, suprasellar-growth and invasion of the cavernous sinus compared to isointense adenomas. Interestingly, somatostatin receptor-3 and dopamine receptor-5 (DRD5) expression levels were associated with extrasellar and/or suprasellar extension. Additionally, DRD5 was also higher in hyperintense adenomas and its expression was directly correlated with Knosp-score and with tumour diameter. Hence, T2-weighted MRI on somatotropinomas represents a potential tool to refine their diagnosis and prognosis, and could support the election of preoperative treatment, when required.
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Affiliation(s)
- María R Alhambra-Expósito
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Service of Endocrinology and Nutrition, HURS, Córdoba, 14004, Spain
| | - Alejandro Ibáñez-Costa
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Department of Cell Biology, Physiology and Immunology, Universidad de Córdoba, Córdoba, 14004, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, 14004, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, 14004, Spain
| | - Paloma Moreno-Moreno
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Service of Endocrinology and Nutrition, HURS, Córdoba, 14004, Spain
| | - Esther Rivero-Cortés
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Department of Cell Biology, Physiology and Immunology, Universidad de Córdoba, Córdoba, 14004, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, 14004, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, 14004, Spain
| | - Mari C Vázquez-Borrego
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Department of Cell Biology, Physiology and Immunology, Universidad de Córdoba, Córdoba, 14004, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, 14004, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, 14004, Spain
| | - Cristóbal Blanco-Acevedo
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Service of Neurosurgery, HURS, Córdoba, 14004, Spain
| | - Álvaro Toledano-Delgado
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Service of Neurosurgery, HURS, Córdoba, 14004, Spain
| | | | | | - Manuel D Gahete
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain.,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain.,Department of Cell Biology, Physiology and Immunology, Universidad de Córdoba, Córdoba, 14004, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, 14004, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, 14004, Spain
| | - Justo P Castaño
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain. .,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain. .,Department of Cell Biology, Physiology and Immunology, Universidad de Córdoba, Córdoba, 14004, Spain. .,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, 14004, Spain. .,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, 14004, Spain.
| | - María A Gálvez
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain. .,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain. .,Service of Endocrinology and Nutrition, HURS, Córdoba, 14004, Spain.
| | - Raúl M Luque
- Maimonides Institute of Biomedical Research of Cordoba, Córdoba, 14004, Spain. .,Reina Sofia University Hospital (HURS), Córdoba, 14004, Spain. .,Department of Cell Biology, Physiology and Immunology, Universidad de Córdoba, Córdoba, 14004, Spain. .,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, 14004, Spain. .,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, 14004, Spain.
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4
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Sominsky L, Hodgson DM, McLaughlin EA, Smith R, Wall HM, Spencer SJ. Linking Stress and Infertility: A Novel Role for Ghrelin. Endocr Rev 2017; 38:432-467. [PMID: 28938425 DOI: 10.1210/er.2016-1133] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 07/24/2017] [Indexed: 12/23/2022]
Abstract
Infertility affects a remarkable one in four couples in developing countries. Psychological stress is a ubiquitous facet of life, and although stress affects us all at some point, prolonged or unmanageable stress may become harmful for some individuals, negatively impacting on their health, including fertility. For instance, women who struggle to conceive are twice as likely to suffer from emotional distress than fertile women. Assisted reproductive technology treatments place an additional physical, emotional, and financial burden of stress, particularly on women, who are often exposed to invasive techniques associated with treatment. Stress-reduction interventions can reduce negative affect and in some cases to improve in vitro fertilization outcomes. Although it has been well-established that stress negatively affects fertility in animal models, human research remains inconsistent due to individual differences and methodological flaws. Attempts to isolate single causal links between stress and infertility have not yet been successful due to their multifaceted etiologies. In this review, we will discuss the current literature in the field of stress-induced reproductive dysfunction based on animal and human models, and introduce a recently unexplored link between stress and infertility, the gut-derived hormone, ghrelin. We also present evidence from recent seminal studies demonstrating that ghrelin has a principal role in the stress response and reward processing, as well as in regulating reproductive function, and that these roles are tightly interlinked. Collectively, these data support the hypothesis that stress may negatively impact upon fertility at least in part by stimulating a dysregulation in ghrelin signaling.
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Affiliation(s)
- Luba Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria 3083, Australia
| | - Deborah M Hodgson
- School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales 2308, Australia
| | - Eileen A McLaughlin
- School of Biological Sciences, Faculty of Science, The University of Auckland, Auckland 1010, New Zealand.,School of Environmental & Life Sciences, Faculty of Science and IT, The University of Newcastle, New South Wales 2308, Australia
| | - Roger Smith
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Lookout Road, New Lambton Heights, New South Wales 2305, Australia.,Priority Research Centre in Reproductive Science, The University of Newcastle, New South Wales 2308, Australia
| | - Hannah M Wall
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria 3083, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria 3083, Australia
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5
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Sarmento-Cabral A, Peinado JR, Halliday LC, Malagon MM, Castaño JP, Kineman RD, Luque RM. Adipokines (Leptin, Adiponectin, Resistin) Differentially Regulate All Hormonal Cell Types in Primary Anterior Pituitary Cell Cultures from Two Primate Species. Sci Rep 2017; 7:43537. [PMID: 28349931 PMCID: PMC5640086 DOI: 10.1038/srep43537] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/25/2017] [Indexed: 12/27/2022] Open
Abstract
Adipose-tissue (AT) is an endocrine organ that dynamically secretes multiple hormones, the adipokines, which regulate key physiological processes. However, adipokines and their receptors are also expressed and regulated in other tissues, including the pituitary, suggesting that locally- and AT-produced adipokines might comprise a regulatory circuit that relevantly modulate pituitary cell-function. Here, we used primary pituitary cell-cultures from two normal nonhuman-primate species [Papio-anubis/Macaca-fascicularis] to determine the impact of different adipokines on the functioning of all anterior-pituitary cell-types. Leptin and resistin stimulated GH-release, a response that was blocked by somatostatin. Conversely, adiponectin decreased GH-release, and inhibited GHRH-, but not ghrelin-stimulated GH-secretion. Furthermore: 1) Leptin stimulated PRL/ACTH/FSH- but not LH/TSH-release; 2) adiponectin stimulated PRL-, inhibited ACTH- and did not alter LH/FSH/TSH-release; and 3) resistin increased ACTH-release and did not alter PRL/LH/FSH/TSH-secretion. These effects were mediated through the activation of common (AC/PKA) and distinct (PLC/PKC, intra-/extra-cellular calcium, PI3K/MAPK/mTOR) signaling-pathways, and by the gene-expression regulation of key receptors/transcriptional-factors involved in the functioning of these pituitary cell-types (e.g. GHRH/ghrelin/somatostatin/insulin/IGF-I-receptors/Pit-1). Finally, we found that primate pituitaries expressed leptin/adiponectin/resistin. Altogether, these and previous data suggest that local-production of adipokines/receptors, in conjunction with circulating adipokine-levels, might comprise a relevant regulatory circuit that contribute to the fine-regulation of pituitary functions.
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Affiliation(s)
- André Sarmento-Cabral
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| | - Juan R Peinado
- Department of Medical Sciences, Faculty of Medicine of Ciudad Real, University of Castilla-La Mancha, Spain
| | - Lisa C Halliday
- Biologic Resources Laboratory, University of Illinois at Chicago, Chicago, Illinois, USA
| | - María M Malagon
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
| | - Justo P Castaño
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| | - Rhonda D Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Medicine, Section of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Raúl M Luque
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
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6
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Legrand R, Lucas N, Breton J, Azhar S, do Rego JC, Déchelotte P, Coëffier M, Fetissov SO. Ghrelin treatment prevents development of activity based anorexia in mice. Eur Neuropsychopharmacol 2016; 26:948-58. [PMID: 27052473 DOI: 10.1016/j.euroneuro.2016.03.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/12/2016] [Accepted: 03/18/2016] [Indexed: 12/30/2022]
Abstract
Stimulation of feeding is necessary for treatment of pathological conditions of chronic malnutrition due to anorexia. Ghrelin, a hunger hormone, is one of the candidate for pharmacological treatments of anorexia, but because of its instability in plasma has limited efficacy. We previously showed that plasmatic IgG protect ghrelin from degradation and that IgG from obese subjects and mice may increase ghrelin׳s orexigenic effect. In this study we tested if ghrelin alone or combined with IgG may improve feeding in chronically food-restricted mice with or without physical activity-based anorexia (ABA) induced by free access to a running wheel. Mice received a single daily intraperitoneal injection of ghrelin (1nM) together or not with total IgG (1nM) from obese ob/ob or lean mice before access to food during 8 days of 3h/day feeding time. We found that both ghrelin and ghrelin combined with IgG from obese, but not lean mice, prevented ABA, however, they were not able to diminish body weight loss. Physical activity was lower during the feeding period and was increased shortly after feeding in mice receiving ghrelin together with IgG from obese mice. In food-restricted mice without ABA, ghrelin treatments did not have significant effects on food intake. Thus, this study supports pharmacological use of ghrelin or ghrelin combined with IgG from obese animals for treatment of anorexia accompanied by elevated physical activity. The utility of combining ghrelin with protective IgG should be further determined in animal models of anorexia with unrestricted access to food.
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Affiliation(s)
- Romain Legrand
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France
| | - Nicolas Lucas
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France
| | - Jonathan Breton
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France
| | - Saïda Azhar
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France
| | - Jean-Claude do Rego
- Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France; Animal Behavioral Platform SCAC, Rouen University, Rouen 76183, France
| | - Pierre Déchelotte
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France; Department of Nutrition, Rouen University Hospital, 76183 Rouen, France
| | - Moïse Coëffier
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France; Department of Nutrition, Rouen University Hospital, 76183 Rouen, France
| | - Sergueï O Fetissov
- Nutrition, Gut and Brain Laboratory, Inserm UMR1073, Rouen University, 76183 France; Institute for Research and Innovation in Biomedicine (IRIB), Rouen 76183, France.
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7
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Ibáñez-Costa A, Gahete MD, Rivero-Cortés E, Rincón-Fernández D, Nelson R, Beltrán M, de la Riva A, Japón MA, Venegas-Moreno E, Gálvez MÁ, García-Arnés JA, Soto-Moreno A, Morgan J, Tsomaia N, Culler MD, Dieguez C, Castaño JP, Luque RM. In1-ghrelin splicing variant is overexpressed in pituitary adenomas and increases their aggressive features. Sci Rep 2015; 5:8714. [PMID: 25737012 PMCID: PMC4649711 DOI: 10.1038/srep08714] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 02/02/2015] [Indexed: 01/26/2023] Open
Abstract
Pituitary adenomas comprise a heterogeneous subset of pathologies causing serious comorbidities, which would benefit from identification of novel, common molecular/cellular biomarkers and therapeutic targets. The ghrelin system has been linked to development of certain endocrine-related cancers. Systematic analysis of the presence and functional implications of some components of the ghrelin system, including native ghrelin, receptors and the recently discovered splicing variant In1-ghrelin, in human normal pituitaries (n = 11) and pituitary adenomas (n = 169) revealed that expression pattern of ghrelin system suffers a clear alteration in pituitary adenomasas comparedwith normal pituitary, where In1-ghrelin is markedly overexpressed. Interestingly, in cultured pituitary adenoma cells In1-ghrelin treatment (acylated peptides at 100 nM; 24–72 h) increased GH and ACTH secretion, Ca2+ and ERK1/2 signaling and cell viability, whereas In1-ghrelin silencing (using a specific siRNA; 100 nM) reduced cell viability. These results indicate that an alteration of the ghrelin system, specially its In1-ghrelin variant, could contribute to pathogenesis of different pituitary adenomas types, and suggest that this variant and its related ghrelin system could provide new tools to identify novel, more general diagnostic, prognostic and potential therapeutic targets in pituitary tumors.
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Affiliation(s)
- Alejandro Ibáñez-Costa
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofia; CIBER Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), 14014 Córdoba, Spain
| | - Manuel D Gahete
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofia; CIBER Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), 14014 Córdoba, Spain
| | - Esther Rivero-Cortés
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofia; CIBER Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), 14014 Córdoba, Spain
| | - David Rincón-Fernández
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofia; CIBER Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), 14014 Córdoba, Spain
| | | | - Manuel Beltrán
- Department of Pathology, Puerta del Mar University Hospital, Cádiz
| | - Andrés de la Riva
- Service of Neurosurgery, Hospital Universitario Reina Sofia, 14004 Córdoba, Spain
| | - Miguel A Japón
- Department of Pathology, Hospital Universitario Virgen del Rocío, 41013 Seville, Spain
| | - Eva Venegas-Moreno
- Metabolism and Nutrition Unit, Hospital Universitario Virgen del Rocío, Instituto de Biomedicina de Sevilla (IBIS), 41013 Seville, Spain
| | - Ma Ángeles Gálvez
- Service of Endocrinology and Nutrition, Hospital Universitario Reina Sofia, and Instituto Maimónides de Investigación Biomédica de Córdoba, 14004 Córdoba, Spain
| | - Juan A García-Arnés
- Department of Endocrinology and Nutrition, Carlos Haya Hospital, 29010 Málaga, Spain
| | - Alfonso Soto-Moreno
- Metabolism and Nutrition Unit, Hospital Universitario Virgen del Rocío, Instituto de Biomedicina de Sevilla (IBIS), 41013 Seville, Spain
| | | | - Natia Tsomaia
- IPSEN Bioscience, Cambridge, 02142 Massachusetts, USA
| | | | - Carlos Dieguez
- Department of Physiology, University of Santiago de Compostela, and CIBER Fisiopatología de la Obesidad y Nutrición, 15782 Santiago de Compostela, Spain
| | - Justo P Castaño
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofia; CIBER Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), 14014 Córdoba, Spain
| | - Raúl M Luque
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofia; CIBER Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), 14014 Córdoba, Spain
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8
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Ibáñez-Costa A, Córdoba-Chacón J, Gahete MD, Kineman RD, Castaño JP, Luque RM. Melatonin regulates somatotrope and lactotrope function through common and distinct signaling pathways in cultured primary pituitary cells from female primates. Endocrinology 2015; 156:1100-10. [PMID: 25545385 PMCID: PMC4330310 DOI: 10.1210/en.2014-1819] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Melatonin (MT) is secreted by the pineal gland and exhibits a striking circadian rhythm in its release. Depending on the species studied, some pituitary hormones also display marked circadian/seasonal patterns and rhythms of secretion. However, the precise relationship between MT and pituitary function remains controversial, and studies focusing on the direct role of MT in normal pituitary cells are limited to nonprimate species. Here, adult normal primate (baboons) primary pituitary cell cultures were used to determine the direct impact of MT on the functioning of all pituitary cell types from the pars distalis. MT increased GH and prolactin (PRL) expression/release in a dose- and time-dependent fashion, a response that was blocked by somatostatin. However, MT did not significantly affect ACTH, FSH, LH, or TSH expression/release. MT did not alter GHRH- or ghrelin-induced GH and/or PRL secretions, suggesting that MT may activate similar signaling pathways as ghrelin/GHRH. The effects of MT on GH/PRL release, which are likely mediated through MT1 receptor, involve both common (adenylyl cyclase/protein kinase A/extracellular calcium-channels) and distinct (phospholipase C/intracellular calcium-channels) signaling pathways. Actions of MT on pituitary cells also included regulation of the expression of other key components for the control of somatotrope/lactotrope function (GHRH, ghrelin, and somatostatin receptors). These results show, for the first time in a primate model, that MT directly regulates somatotrope/lactotrope function, thereby lending support to the notion that the actions of MT on these cells might substantially contribute to the define daily patterns of GH and PRL observed in primates and perhaps in humans.
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Affiliation(s)
- Alejandro Ibáñez-Costa
- Department of Cell Biology, Physiology, and Immunology (A.I.-C., J.C.-C., M.D.G., J.P.C., R.M.L.), University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba, Hospital Universitario Reina Sofia; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición; and Campus de Excelencia Internacional Agroalimentario (ceiA3), E-14014 Córdoba, Spain; and Department of Medicine (J.C.-C., R.D.K.), Section of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago and Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612
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9
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Gahete MD, Rincón-Fernández D, Villa-Osaba A, Hormaechea-Agulla D, Ibáñez-Costa A, Martínez-Fuentes AJ, Gracia-Navarro F, Castaño JP, Luque RM. Ghrelin gene products, receptors, and GOAT enzyme: biological and pathophysiological insight. J Endocrinol 2014; 220:R1-24. [PMID: 24194510 DOI: 10.1530/joe-13-0391] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin is a 28-amino acid acylated hormone, highly expressed in the stomach, which binds to its cognate receptor (GHSR1a) to regulate a plethora of relevant biological processes, including food intake, energy balance, hormonal secretions, learning, inflammation, etc. However, ghrelin is, in fact, the most notorious component of a complex, intricate regulatory system comprised of a growing number of alternative peptides (e.g. obestatin, unacylated ghrelin, and In1-ghrelin, etc.), known (GHSRs) and, necessarily unknown receptors, as well as modifying enzymes (e.g. ghrelin-O-acyl-transferase), which interact among them as well as with other regulatory systems in order to tightly modulate key (patho)-physiological processes. This multiplicity of functions and versatility of the ghrelin system arise from a dual, genetic and functional, complexity. Importantly, a growing body of evidence suggests that dysregulation in some of the components of the ghrelin system can lead to or influence the development and/or progression of highly concerning pathologies such as endocrine-related tumors, inflammatory/cardiovascular diseases, and neurodegeneration, wherein these altered components could be used as diagnostic, prognostic, or therapeutic targets. In this context, the aim of this review is to integrate and comprehensively analyze the multiple components and functions of the ghrelin system described to date in order to define and understand its biological and (patho)-physiological significance.
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Affiliation(s)
- Manuel D Gahete
- Department of Cell Biology, Physiology and Immunology, Campus Universitario de Rabanales, Edificio Severo Ochoa (C6), Planta 3, University of Córdoba, 14014-Córdoba; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), University of Córdoba; Reina Sofia University Hospital, Córdoba; and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
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10
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Córdoba-Chacón J, Gahete MD, Pozo-Salas AI, Martínez-Fuentes AJ, de Lecea L, Gracia-Navarro F, Kineman RD, Castaño JP, Luque RM. Cortistatin is not a somatostatin analogue but stimulates prolactin release and inhibits GH and ACTH in a gender-dependent fashion: potential role of ghrelin. Endocrinology 2011; 152:4800-12. [PMID: 21971153 PMCID: PMC3230064 DOI: 10.1210/en.2011-1542] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cortistatin (CST) and somatostatin (SST) evolve from a common ancestral gene and share remarkable structural, pharmacological, and functional homologies. Although CST has been considered as a natural SST-analogue acting through their shared receptors (SST receptors 1-5), emerging evidence indicates that these peptides might in fact exert unique roles via selective receptors [e.g. CST, not SST, binds ghrelin receptor growth hormone secretagogue receptor type 1a (GHS-R1a)]. To determine whether the role of endogenous CST is different from SST, we characterized the endocrine-metabolic phenotype of male/female CST null mice (cort-/-) at hypothalamic-pituitary-systemic (pancreas-stomach-adrenal-liver) levels. Also, CST effects on hormone expression/secretion were evaluated in primary pituitary cell cultures from male/female mice and female primates (baboons). Specifically, CST exerted an unexpected stimulatory role on prolactin (PRL) secretion, because both male/female cort-/- mice had reduced PRL levels, and CST treatment (in vivo and in vitro) increased PRL secretion, which could be blocked by a GHS-R1a antagonist in vitro and likely relates to the decreased success of female cort-/- in first-litter pup care at weaning. In contrast, CST inhibited GH and adrenocorticotropin-hormone axes in a gender-dependent fashion. In addition, a rise in acylated ghrelin levels was observed in female cort-/- mice, which were associated with an increase in stomach ghrelin/ghrelin O-acyl transferase expression. Finally, CST deficit uncovered a gender-dependent role of this peptide in the regulation of glucose-insulin homeostasis, because male, but not female, cort-/- mice developed insulin resistance. The fact that these actions are not mimicked by SST and are strongly gender dependent offers new grounds to investigate the hitherto underestimated physiological relevance of CST in the regulation of physiological/metabolic processes.
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11
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Baragli A, Lanfranco F, Allasia S, Granata R, Ghigo E. Neuroendocrine and metabolic activities of ghrelin gene products. Peptides 2011; 32:2323-32. [PMID: 22056513 DOI: 10.1016/j.peptides.2011.10.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 10/03/2011] [Accepted: 10/25/2011] [Indexed: 12/15/2022]
Abstract
Acylated ghrelin (AG) is a 28 amino acid gastric peptide a natural ligand for the growth hormone secretagogue (GHS) receptor type 1a (GHS-R1a), endowed with GH-secreting and orexigenic properties. Besides, ghrelin exerts several peripheral metabolic actions, including modulation of glucose homeostasis and stimulation of adipogenesis. Notably, AG administration causes hyperglycemia in rodents as in humans. Ghrelin pleiotropy is supported by a widespread expression of the ghrelin gene, of GHS-R1a and other unknown ghrelin binding sites. The existence of alternative receptors for AG, of several natural ligands for GHS-R1a and of acylation-independent ghrelin non-neuroendocrine activities, suggests that there might be a complex 'ghrelin system' not yet completely explored. Moreover, the patho-physiological implications of unacylated ghrelin (UAG), and obestatin (Ob), the other two ghrelin gene-derived peptides, need to be clarified. Within the next few years, we may better understand the 'ghrelin system', where we might envisage clinical applications.
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Affiliation(s)
- Alessandra Baragli
- Laboratory of Molecular and Cellular Endocrinology, Division of Endocrinology, Department of Internal Medicine, University of Turin, Turin, Italy.
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12
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Messini CI, Dafopoulos K, Chalvatzas N, Georgoulias P, Anifandis G, Messinis IE. Effect of ghrelin and metoclopramide on prolactin secretion in normal women. J Endocrinol Invest 2011; 34:276-9. [PMID: 20530986 DOI: 10.1007/bf03347085] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Administration of ghrelin to women stimulates the secretion of PRL but the mechanism is not known. AIM The aim of the study was to investigate the effect of the dopamine receptor blocker, metoclopramide, on ghrelin-induced PRL release. SUBJECTS AND METHODS Ten healthy normally cycling women were studied in the midluteal phase of 4 menstrual cycles. A single dose of normal saline (cycle 1), ghrelin (1 μg/kg) (cycle 2), metoclopramide (20 mg) (cycle 3), and ghrelin plus metoclopramide (cycle 4) was given to the women iv. Blood samples in relation to the iv injection (time 0) were taken at -15, 0, 15, 30, 45, 60, 75, 90, and 120 min. The response of PRL and GH was assessed. RESULTS Following ghrelin administration (cycles 2 and 4), plasma ghrelin and serum PRL and GH levels increased rapidly, peaking at 30 min (p<0.001). PRL was also increased after the injection of metoclopramide (p<0.001, cycle 3), but the increase was much greater than after the administration of ghrelin. The combination of ghrelin and metoclopramide stimulated PRL secretion to the same extent with metoclopramide alone. No changes in GH and PRL levels were seen after saline injection. CONCLUSIONS These results demonstrate that the stimulating effect of ghrelin on PRL secretion is not additive with that of metoclopramide, although a dose range study might provide further information.
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Affiliation(s)
- C I Messini
- Department of Obstetrics and Gynaecology Medical School, University of Thessalia, 41110 Larissa, Greece
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13
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Lim CT, Kola B, Korbonits M, Grossman AB. Ghrelin's role as a major regulator of appetite and its other functions in neuroendocrinology. PROGRESS IN BRAIN RESEARCH 2010; 182:189-205. [PMID: 20541666 DOI: 10.1016/s0079-6123(10)82008-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ghrelin is a circulating growth-hormone-releasing and appetite-inducing brain-gut peptide. It is a known natural ligand of the growth hormone secretagogue receptor (GHS-R). Ghrelin is acylated on its serine 3 residue by ghrelin O-acyltransferase (GOAT). The acylation is essential for its orexigenic and adipogenic effects. Ghrelin exerts its central orexigenic effect through activation of various hypothalamic and brain stem neurons. Several new intracellular targets/mediators of the appetite-inducing effect of ghrelin in the hypothalamus have recently been identified, including the AMP-activated protein kinase, its upstream kinase calmodulin kinase kinase 2, components of the fatty acid pathway and the uncoupling protein 2. The ghrelin/GOAT/GHS-R system is now recognised as a potential target for the development of anti-obesity treatment. Ghrelin regulates the function of the anterior pituitary through stimulation of secretion not only of growth hormone, but also of adrenocorticotrophin and prolactin. The implication of ghrelin and its receptor in the pathogenesis of the neuroendocrine tumors will also be discussed in this review.
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Affiliation(s)
- Chung Thong Lim
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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14
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Veldhuis JD, Bowers CY. Integrating GHS into the Ghrelin System. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010:879503. [PMID: 20798846 PMCID: PMC2925380 DOI: 10.1155/2010/879503] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/30/2009] [Indexed: 12/21/2022]
Abstract
Oligopeptide derivatives of metenkephalin were found to stimulate growth-hormone (GH) release directly by pituitary somatotrope cells in vitro in 1977. Members of this class of peptides and nonpeptidyl mimetics are referred to as GH secretagogues (GHSs). A specific guanosine triphosphatate-binding protein-associated heptahelical transmembrane receptor for GHS was cloned in 1996. An endogenous ligand for the GHS receptor, acylghrelin, was identified in 1999. Expression of ghrelin and homonymous receptor occurs in the brain, pituitary gland, stomach, endothelium/vascular smooth muscle, pancreas, placenta, intestine, heart, bone, and other tissues. Principal actions of this peptidergic system include stimulation of GH release via combined hypothalamopituitary mechanisms, orexigenesis (appetitive enhancement), insulinostasis (inhibition of insulin secretion), cardiovascular effects (decreased mean arterial pressure and vasodilation), stimulation of gastric motility and acid secretion, adipogenesis with repression of fat oxidation, and antiapoptosis (antagonism of endothelial, neuronal, and cardiomyocyte death). The array of known and proposed interactions of ghrelin with key metabolic signals makes ghrelin and its receptor prime targets for drug development.
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Affiliation(s)
- Johannes D. Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Cyril Y. Bowers
- Division of Endocrinology, Department of Internal Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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15
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Strassburg S, Anker SD, Castaneda TR, Burget L, Perez-Tilve D, Pfluger PT, Nogueiras R, Halem H, Dong JZ, Culler MD, Datta R, Tschöp MH. Long-term effects of ghrelin and ghrelin receptor agonists on energy balance in rats. Am J Physiol Endocrinol Metab 2008; 295:E78-84. [PMID: 18460598 PMCID: PMC2493589 DOI: 10.1152/ajpendo.00040.2008] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor (GHS-R), is the only circulating agent to powerfully promote a positive energy balance. Such action is mediated predominantly by central nervous system pathways controlling food intake, energy expenditure, and nutrient partitioning. The ghrelin pathway may therefore offer therapeutic potential for the treatment of catabolic states. However, the potency of the endogenous hormone ghrelin is limited due to a short half-life and the fragility of its bioactivity ensuring acylation at serine 3. Therefore, we tested the metabolic effects of two recently generated GHS-R agonists, BIM-28125 and BIM-28131, compared with ghrelin. All agents were administered continuously for 1 mo in doses of 50 and 500 nmol x kg(-1) x day(-1) using implanted subcutaneous minipumps in rats. High-dose treatment with single agonists or ghrelin increased body weight gain by promoting fat mass, whereas BIM-28131 was the only one also increasing lean mass significantly. Food intake increased during treatment with BIM-28131 or ghrelin, whereas no effects on energy expenditure were detected. With the lower dose, only BIM-28131 had a significant effect on body weight. This also held true when the compound was administered by subcutaneous injection three times/day. No symptoms or signs of undesired effects were observed in any of the studies or treated groups. These results characterize BIM-28131 as a promising GHS-R agonist with an attractive action profile for the treatment of catabolic disease states such as cachexia.
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Affiliation(s)
- Sabine Strassburg
- Department of Psychiatry, Obesity Research Centre-Genome Research Institute, Univ. of Cincinnati-College of Medicine, Cincinnati, OH, USA
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16
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Fusco A, Bianchi A, Mancini A, Milardi D, Giampietro A, Cimino V, Porcelli T, Romualdi D, Guido M, Lanzone A, Pontecorvi A, De Marinis L. Effects of ghrelin administration on endocrine and metabolic parameters in obese women with polycystic ovary syndrome. J Endocrinol Invest 2007; 30:948-56. [PMID: 18250617 DOI: 10.1007/bf03349243] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION The novel peptide ghrelin displays multiple endocrine and non-endocrine actions. Its strong GH-releasing activity in humans has long been recognized. However, in obesity, ghrelin administration induces a blunted GH secretion, enhances glucose and reduces insulin levels. The effects of ghrelin administration have not been investigated in polycystic ovary syndrome (PCOS), which can be associated with obesity, hyperinsulinism, and GH hyposecretion. Leptin is a mediator for energy balance opposed to ghrelin; both of them are supposed to act as regulators of reproductive functions. AIM OF THE STUDY Evaluate the endocrine and metabolic response to ghrelin administration in PCOS obese patients compared to body mass index (BMI)-matched and normal weight women. MATERIALS AND METHODS Nine obese PCOS patients (BMI: 35.4+/-1.2 kg/m(2)) (OB PCOS), 6 obese controls (BMI: 38.4+/-1.1 kg/m(2)) (Ob), and 6 normal-weight women (BMI: 23+/-0.6 kg/m(2)) (NW) were enrolled in the study. In all patients we performed: 1) basal hormonal evaluation including FSH, LH, estradiol, testosterone, androstenedione, DHEAS, SHBG, 17-hydroxyprogesterone (17OHP), IGF-I, free T3 (FT3), free T4 (FT4) and ghrelin levels; 2) metabolic evaluation as follows: concentration of non-esterified fatty acid (NEFA) and oral glucose tolerance test (OGTT) (75 g); homeostasis model assessment (HOMA); glucose and insulin response to ghrelin administration (1 microg/kg); 3) measurement of GH, PRL, TSH, and leptin levels after infusion of ghrelin. RESULTS Administration of ghrelin increased glucose and reduced insulin levels in both Ob and OB PCOS. Moreover, ghrelin enhanced GH and PRL levels in all groups but it did not modify TSH and leptin levels. GH peak and area under the curve (AUC) in OB PCOS and Ob were lower than controls (p<0.05). Similar PRL peak and AUC values were observed in all groups. CONCLUSIONS In both obese and PCOS obese patients, leptin levels are not influenced by ghrelin administration. Moreover, the GH response after ghrelin administration is blunted. However, ghrelin exerts glucose- enhancing and insulin-lowering effects, the latter absent in NW.
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Affiliation(s)
- A Fusco
- Section of Endocrinology, Department of Internal Medicine, Catholic University School of Medicine, 00168 Rome, Italy
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17
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Kineman RD, Luque RM. Evidence that ghrelin is as potent as growth hormone (GH)-releasing hormone (GHRH) in releasing GH from primary pituitary cell cultures of a nonhuman primate (Papio anubis), acting through intracellular signaling pathways distinct from GHRH. Endocrinology 2007; 148:4440-9. [PMID: 17540720 DOI: 10.1210/en.2007-0441] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ghrelin is more effective than GHRH in stimulating GH release in normal adult humans and monkeys in vivo. This robust effect of ghrelin has been largely attributed to regulation of hypothalamic input, whereas the direct effect of ghrelin on pituitary GH release has been minimized by the observation that ghrelin has only a modest impact on GH release, compared with GHRH, in cultures prepared from human fetal pituitaries and GH-producing adenomas, as well as pituitaries from nonprimate species. However, comparable in vitro studies have not been performed to test the direct effect of ghrelin on normal adult primates. Therefore, in the present study, primary pituitary cell cultures from female baboons (Papio anubis) were used as a model system to test the direct effects of ghrelin on primate somatotrope function. In this model, both ghrelin and GHRH increased GH release in a dose-dependent fashion. Surprisingly, at maximal concentrations (10 nM), both ghrelin and GHRH elicited a robust increase in GH release (4 and 24 h, respectively), and both up-regulated GH secretagogue-receptor and GHRH-receptor mRNA levels (24 h). Combined treatment with ghrelin and GHRH resulted in an additive effect on GH release, suggesting that distinct intracellular signaling pathways are activated by each ligand, as confirmed by the use of specific inhibitors of intracellular signaling. Together, these results present the first evidence that a direct effect of ghrelin on somatotrope function may play a major role in stimulating GH release in primates.
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Affiliation(s)
- Rhonda D Kineman
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
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18
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Couch M, Lai V, Cannon T, Guttridge D, Zanation A, George J, Hayes DN, Zeisel S, Shores C. Cancer cachexia syndrome in head and neck cancer patients: part I. Diagnosis, impact on quality of life and survival, and treatment. Head Neck 2007; 29:401-11. [PMID: 17285641 DOI: 10.1002/hed.20447] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Cancer cachexia is a debilitating, wasting condition that affects many cancer patients, including those with head and neck cancer. The overall incidence of cancer cachexia is quite high for some types of cancer, and cachexia will be the main cause of death for more than 20% of all cancer patients. This syndrome uniquely challenges patients with head and neck cancer. This article outlines the diagnosis of cancer cachexia, reviews its impact on patient quality of life (QOL) and survival, and updates the reader on potential therapies that may suppress it. METHODS A comprehensive literature search was performed using PubMed of the National Library of Medicine, which includes more than 15 million citations back to the 1950s. The Cochrane Library and Google search engine were used as well. RESULTS This syndrome differs significantly from starvation, and thus accurate and timely diagnosis is essential. Nutritional therapy alone is insufficient. Current management strategies include corticosteroids and megesterol acetate, in conjunction with nutritional therapy. Future strategies may include nutraceuticals, omega-3 fatty acids, inflammatory antagonists, and other targeted treatments. CONCLUSIONS Because cancer cachexia differs significantly from starvation, nutritional supplementation must be used in conjunction with other anti-cachexia agents to reverse the chronic systemic inflammatory state and the effects of circulating tumor-derived factors seen in cachexia. Careful identification of patients at risk and those suffering from this syndrome will lead to better outcomes and treatments. Ultimately, more research is needed to better treat this devastating condition.
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Affiliation(s)
- Marion Couch
- Department of Otolaryngology/Head and Neck Surgery, University of North Carolina School of Medicine, G0412 Neurosciences Hospital, Chapel Hill, NC 27599-7070, USA.
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Pecori Giraldi F, Bucciarelli LG, Saccani A, Scacchi M, Pesce S, Losa M, Cavagnini F. Ghrelin stimulates adrenocorticotrophic hormone (ACTH) secretion by human ACTH-secreting pituitary adenomas in vitro. J Neuroendocrinol 2007; 19:208-12. [PMID: 17280594 DOI: 10.1111/j.1365-2826.2006.01521.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ghrelin is a brain-gut peptide with wide-ranging endocrine, metabolic, cardiovascular and neural effects. Ghrelin, like its synthetic counterparts, the growth hormone (GH) secretagogues, has been shown to markedly stimulate adrenocorticotrophic hormone (ACTH) and cortisol secretion in humans and the ACTH-releasing effect of GH secretagogues is even greater in patients with pituitary ACTH-secreting tumours. Furthermore, these tumours synthesize ghrelin itself, suggesting an intrapituitary ghrelin circuit. The aim of the present study was to evaluate the effect of ghrelin on ACTH secretion by human pituitary corticotroph tumours in vitro to test the functionality of this circuit. Nine ACTH-secreting pituitary tumours (four microadenomas, five macroadenomas) were collected during surgery and incubated with 10-100 nM human ghrelin or with 10 nM human corticotrophin-releasing hormone (CRH). Control experiments were performed in rat anterior pituitary primary cultures. ACTH secretion was assessed after 4 h and 24 h incubation by immunometric assay. After 4 h of incubation with ghrelin, medium ACTH concentrations were two- to ten-fold higher compared to ACTH concentrations in unstimulated wells. The ACTH-releasing effect of ghrelin was significantly less than the response elicited by 10 nM CRH (up to 40-fold) Similar results were obtained after 24 h of incubation and a superimposable response pattern was observed in rat anterior pituitary primary cultures. The present study demonstrates that the endogenous GH secretagogue, ghrelin, stimulates ACTH secretion directly from human tumoural corticotrophs, as well as from normal rat pituitary, and indicates that the marked ACTH release elicited by ghrelin in patients with Cushing's disease in vivo is due, at least in part, to its action on the pituitary tumour. However, the reversal of the response pattern reported in vivo, with ghrelin proving a lesser stimulant than CRH in vitro, suggests that additional, suprapituitary mechanisms are involved in the in vivo response. Moreover, these data uphold the concept of a functional intratumoural ghrelin paracrine circuit in human corticotroph adenomas.
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Affiliation(s)
- F Pecori Giraldi
- Department of Endocrinology, University of Milan, Ospedale San Luca, Istituto Auxologico Italiano IRCCS, Milan, Italy.
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20
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Abstract
Ghrelin is a 28 amino-acid hormone with multiple functions. It is predominantly produced by the stomach but has also been detected in other organs, including the small intestine, pancreas, hypothalamus and pituitary, as well as in the immune system and almost every other normal human tissue examined. It is also present in neuroendocrine tumours, pituitary adenomas, endocrine tumours of the pancreas, breast tumours, and thyroid and medullary thyroid carcinomas. Ghrelin is a brain-gut peptide with growth hormone-releasing and appetite-inducing activities, and is the endogenous ligand of the G protein-coupled growth hormone secretagogue receptor (GHS-R). In this review we comprehensively summarize the available data regarding (a) the expression of ghrelin and the GHS-R in normal endocrine tissues and in pituitary adenomas and neuroendocrine tumours, (b) the levels of circulating ghrelin in patients with pituitary adenomas and neuroendocrine tumours and (c) the effects of ghrelin administration in these patients on the levels of other hormones and on the rate of proliferation of the tumour. It is clear that ghrelin has many more functions and is involved in many more processes than was initially postulated, and its endocrine, paracrine and autocrine effects play a role in its physiological and pathophysiological functions.
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Affiliation(s)
- Chrysanthia A Leontiou
- Department of Endocrinology, William Harvey Research Institute, Barts and the London Medical School, John Vane Science Centre, Charterhouse Square, London, EC1M 6BQ, UK
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Tulipano G, Taylor JE, Halem HA, Datta R, Dong JZ, Culler MD, Bianchi I, Cocchi D, Giustina A. Glucocorticoid inhibition of growth in rats: partial reversal with the full-length ghrelin analog BIM-28125. Pituitary 2007; 10:267-74. [PMID: 17587180 DOI: 10.1007/s11102-007-0054-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Glucocorticoids are important immunosuppressive hormones; these steroids also inhibit somatic growth by decreased growth hormone (GH) secretion and induced protein catabolism. The ability of ghrelin, the endogenous ligand for the GHS-1a receptor, to increase body weight is attributed to a combination of enhanced food intake, increased gastric emptying and increased food assimilation, coupled with potent GH releasing activity. The aim of the present study was to evaluate the ability of a full-length, metabolically stabilized ghrelin agonist, BIM-28125, to reverse the dexamethasone-induced decrease of growth rate of prepubertal Sprague-Dawley male rats. Twenty-one days old rats were randomly assigned to two treatment groups. Beginning on day 23 of age, 16 animals were treated ip either with saline or DEX (40 microg/kg/day). On day 33 after birth, these two groups were further subdivided and treated sc with either vehicle or BIM-28125 (80 nmol/kg, t.i.d.). On day 47 after birth, rats were killed and trunk blood was collected for hormone determinations. DEX significantly reduced final body weight and nose-anal length; BIM-28125 increased linear growth in saline-treated rats and reversed growth inhibition in DEX-treated rats. The inhibitory effects of DEX on somatic growth was paralleled by decreased 24 h food intake (FI), decreased food efficiency (FE) and lower plasma IGF-1 levels versus vehicle-treated rats. BIM-28125 induced an increase of FI, FE and plasma IGF-1 in saline-treated rats, and reversed the inhibitory effects of DEX. These preclinical results leads to the conclusion that BIM-28125 may represent a good tool to reverse the catabolic effects induced by glucocorticoids.
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Affiliation(s)
- Giovanni Tulipano
- Department of Biomedical Sciences and Biotechnologies, University of Brescia, Brescia, Italy
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22
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Muccioli G, Baragli A, Granata R, Papotti M, Ghigo E. Heterogeneity of ghrelin/growth hormone secretagogue receptors. Toward the understanding of the molecular identity of novel ghrelin/GHS receptors. Neuroendocrinology 2007; 86:147-64. [PMID: 17622734 DOI: 10.1159/000105141] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 05/21/2007] [Indexed: 12/23/2022]
Abstract
Ghrelin is a gastric polypeptide displaying strong GH-releasing activity by activation of the type 1a GH secretagogue receptor (GHS-R1a) located in the hypothalamus-pituitary axis. GHS-R1a is a G-protein-coupled receptor that, upon the binding of ghrelin or synthetic peptidyl and non-peptidyl ghrelin-mimetic agents known as GHS, preferentially couples to G(q), ultimately leading to increased intracellular calcium content. Beside the potent GH-releasing action, ghrelin and GHS influence food intake, gut motility, sleep, memory and behavior, glucose and lipid metabolism, cardiovascular performances, cell proliferation, immunological responses and reproduction. A growing body of evidence suggests that the cloned GHS-R1a alone cannot be the responsible for all these effects. The cloned GHS-R1b splice variant is apparently non-ghrelin/GHS-responsive, despite demonstration of expression in neoplastic tissues responsive to ghrelin not expressing GHS-R1a; GHS-R1a homologues sensitive to ghrelin are capable of interaction with GHS-R1b, forming heterodimeric species. Furthermore, GHS-R1a-deficient mice do not show evident abnormalities in growth and diet-induced obesity, suggesting the involvement of another receptor. Additional evidence of the existence of another receptor is that ghrelin and GHS do not always share the same biological activities and activate a variety of intracellular signalling systems besides G(q). The biological actions on the heart, adipose tissue, pancreas, cancer cells and brain shared by ghrelin and the non-acylated form of ghrelin (des-octanoyl ghrelin), which does not bind GHS-R1a, represent the best evidence for the existence of a still unknown, functionally active binding site for this family of molecules. Finally, located in the heart and blood vessels is the scavenger receptor CD36, involved in the endocytosis of the pro-atherogenic oxidized low-density lipoproteins, which is a pharmacologically and structurally distinct receptor for peptidyl GHS and not for ghrelin. This review highlights the most recently discovered features of GHS-R1a and the emerging evidence for a novel group of receptors that are not of the GHS1a type; these appear involved in the transduction of the multiple levels of information provided by GHS and ghrelin.
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Affiliation(s)
- Giampiero Muccioli
- Division of Pharmacology, Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, Turin, Italy
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Hosoda H, Kojima M, Kangawa K. Biological, physiological, and pharmacological aspects of ghrelin. J Pharmacol Sci 2006; 100:398-410. [PMID: 16612045 DOI: 10.1254/jphs.crj06002x] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Ghrelin, identified as an endogenous ligand for the growth hormone secretagogue receptor, functions as a somatotrophic and orexigenic signal from the stomach. Ghrelin has a unique post-translational modification: the hydroxyl group of the third amino acid, usually a serine but in some species a threonine, is esterified by octanoic acid and is essential for ghrelin's biological activities. The secretion of ghrelin increases under conditions of negative energy-balance, such as starvation, cachexia, and anorexia nervosa, whereas its expression decreases under conditions of positive energy-balance such as feeding, hyperglycemia, and obesity. In addition to having a powerful effect on the secretion of growth hormone, ghrelin stimulates food intake and transduces signals to hypothalamic regulatory nuclei that control energy homeostasis. Thus, it is interesting to note that the stomach may play an important role in not only digestion but also pituitary growth hormone release and central feeding regulation. We summarized recent findings on the integration of ghrelin into neuroendocrine networks that regulate food intake, energy balance, gastrointestinal function and growth.
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Affiliation(s)
- Hiroshi Hosoda
- Department of Biochemistry, National Cardiovascular Center Research Institute, Osaka, Japan
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