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Hassanzadeh-Taheri M, Mohammadifard M, Erfanian Z, Hosseini M. The maternal reduced uteroplacental perfusion model of preeclampsia induces sexually dimorphic metabolic responses in rat offspring. Biol Sex Differ 2022; 13:48. [PMID: 36109770 PMCID: PMC9479437 DOI: 10.1186/s13293-022-00458-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/31/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Offspring born to preeclamptic mothers are prone to obesity, diabetes and hypertension in later life, but still, studies investigating the underlying mechanism are limited. Here, we aimed to investigate the impact of the reduced uteroplacental perfusion (RUPP) rat preeclampsia model on offspring metabolic outcomes. METHODS Timed pregnant Wistar rats underwent RUPP or sham surgeries on day 14 of gestation. Glucometabolic parameters were evaluated on postnatal days (PND), 14 (childhood), and 60 (young adult). In addition, intraperitoneal glucose tolerance test (IPGTT), homeostatic model assessment of insulin resistance (HOMA-IR), immunohistochemical staining for insulin in pancreatic islets, arterial blood pressure and 24-h urine protein (24hUP) excretion were performed at PND60. RESULTS Male, but not female, young adult rats (PND60) of RUPP dams exhibited an impaired IPGTT, decreased circulatory insulin and weakened pancreatic insulin immunoreactivity. Compared to the male offspring of the sham group, the body mass of male RUPP offspring significantly caught up after PND42, but it was not sex-specific. RUPP pups also exhibited upregulations in glucagon (only males) and ghrelin (both sexes with a more significant increase in males) during PND14-PND60. However, in sham offspring (both sexes), glucagon levels were downregulated and ghrelin levels unchanged during PND14-PND60. The blood pressure, HOMA-IR and 24hUP values did not alter in RUPP pups. CONCLUSIONS The overall results suggest that maternal RUPP has negative and sex-specific impacts on insulin, glucagon and ghrelin regulations in offspring and that, as young adults, male RUPP rats may be more prone to develop obesity and diabetes.
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Affiliation(s)
- Mohammadmehdi Hassanzadeh-Taheri
- Cellular and Molecular Research Center, Department of Anatomical Sciences, Birjand University of Medical Sciences, Birjand, Iran
| | - Mahtab Mohammadifard
- Department of Pathology, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Zahra Erfanian
- Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Mehran Hosseini
- Cellular and Molecular Research Center, Department of Anatomical Sciences, Birjand University of Medical Sciences, Birjand, Iran.
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2
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Deschaine SL, Farokhnia M, Gregory-Flores A, Zallar LJ, You ZB, Sun H, Harvey DM, Marchette RCN, Tunstall BJ, Mani BK, Moose JE, Lee MR, Gardner E, Akhlaghi F, Roberto M, Hougland JL, Zigman JM, Koob GF, Vendruscolo LF, Leggio L. A closer look at alcohol-induced changes in the ghrelin system: novel insights from preclinical and clinical data. Addict Biol 2022; 27:e13033. [PMID: 33908131 PMCID: PMC8548413 DOI: 10.1111/adb.13033] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/16/2021] [Accepted: 03/06/2021] [Indexed: 02/06/2023]
Abstract
Ghrelin is a gastric-derived peptide hormone with demonstrated impact on alcohol intake and craving, but the reverse side of this bidirectional link, that is, the effects of alcohol on the ghrelin system, remains to be fully established. To further characterize this relationship, we examined (1) ghrelin levels via secondary analysis of human laboratory alcohol administration experiments with heavy-drinking participants; (2) expression of ghrelin, ghrelin receptor, and ghrelin-O-acyltransferase (GOAT) genes (GHRL, GHSR, and MBOAT4, respectively) in post-mortem brain tissue from individuals with alcohol use disorder (AUD) versus controls; (3) ghrelin levels in Ghsr knockout and wild-type rats following intraperitoneal (i.p.) alcohol administration; (4) effect of alcohol on ghrelin secretion from gastric mucosa cells ex vivo and GOAT enzymatic activity in vitro; and (5) ghrelin levels in rats following i.p. alcohol administration versus a calorically equivalent non-alcoholic sucrose solution. Acyl- and total-ghrelin levels decreased following acute alcohol administration in humans, but AUD was not associated with changes in central expression of ghrelin system genes in post-mortem tissue. In rats, alcohol decreased acyl-ghrelin, but not des-acyl-ghrelin, in both Ghsr knockout and wild-type rats. No dose-dependent effects of alcohol were observed on acyl-ghrelin secretion from gastric mucosa cells or on GOAT acylation activity. Lastly, alcohol and sucrose produced distinct effects on ghrelin in rats despite equivalent caloric value. Our findings suggest that alcohol acutely decreases peripheral ghrelin concentrations in vivo, but not in proportion to alcohol's caloric value or through direct interaction with ghrelin-secreting gastric mucosal cells, the ghrelin receptor, or the GOAT enzyme.
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Affiliation(s)
- Sara L. Deschaine
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National, Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore, Maryland, USA
| | - Mehdi Farokhnia
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National, Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore, 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
| | - Adriana Gregory-Flores
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National, Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore, Maryland, USA,Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Lia J. Zallar
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National, Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore, Maryland, USA,Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Zhi-Bing You
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Hui Sun
- Clinical Core Laboratory, Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Deon M. Harvey
- Office of the Scientific Director, National Institute on Drug Abuse, Baltimore, Maryland, USA
| | - Renata C. N. Marchette
- Center on Compulsive Behaviors, National Institutes of Health, Bethesda, Maryland, USA,Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Brendan J. Tunstall
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Bharath K. Mani
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Jacob E. Moose
- Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York, USA,Department of Chemistry, Syracuse University, Syracuse, New York, USA
| | - Mary R. Lee
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National, Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore, Maryland, USA
| | - Eliot Gardner
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Fatemeh Akhlaghi
- Clinical Pharmacokinetics Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Marisa Roberto
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California, USA
| | - James L. Hougland
- Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York, USA,Department of Chemistry, Syracuse University, Syracuse, New York, USA,BioInspired Syracuse, Syracuse University, Syracuse, New York, USA
| | - Jeffrey M. Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA,Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA,Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - George F. Koob
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Leandro F. Vendruscolo
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National, Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore, Maryland, USA,Center on Compulsive Behaviors, National Institutes of Health, Bethesda, Maryland, USA,Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, School of Public Health, Brown University, Providence, Rhode Island, 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, District of Columbia, USA
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3
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Devesa J. The Complex World of Regulation of Pituitary Growth Hormone Secretion: The Role of Ghrelin, Klotho, and Nesfatins in It. Front Endocrinol (Lausanne) 2021; 12:636403. [PMID: 33776931 PMCID: PMC7991839 DOI: 10.3389/fendo.2021.636403] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/12/2021] [Indexed: 12/27/2022] Open
Abstract
The classic concept of how pituitary GH is regulated by somatostatin and GHRH has changed in recent years, following the discovery of peripheral hormones involved in the regulation of energy homeostasis and mineral homeostasis. These hormones are ghrelin, nesfatins, and klotho. Ghrelin is an orexigenic hormone, released primarily by the gastric mucosa, although it is widely expressed in many different tissues, including the central nervous system and the pituitary. To be active, ghrelin must bind to an n-octanoyl group (n = 8, generally) on serine 3, forming acyl ghrelin which can then bind and activate a G-protein-coupled receptor leading to phospholipase C activation that induces the formation of inositol 1,4,5-triphosphate and diacylglycerol that produce an increase in cytosolic calcium that allows the release of GH. In addition to its direct action on somatotrophs, ghrelin co-localizes with GHRH in several neurons, facilitating its release by inhibiting somatostatin, and acts synergistically with GHRH stimulating the synthesis and secretion of pituitary GH. Gastric ghrelin production declines with age, as does GH. Klotho is an anti-aging agent, produced mainly in the kidneys, whose soluble circulating form directly induces GH secretion through the activation of ERK1/2 and inhibits the inhibitory effect that IGF-I exerts on GH. Children and adults with untreated GH-deficiency show reduced plasma levels of klotho, but treatment with GH restores them to normal values. Deletions or mutations of the Klotho gene affect GH production. Nesfatins 1 and 2 are satiety hormones, they inhibit food intake. They have been found in GH3 cell cultures where they significantly reduce the expression of gh mRNA and that of pituitary-specific positive transcription factor 1, consequently acting as inhibitors of GH production. This is a consequence of the down-regulation of the cAMP/PKA/CREB signaling pathway. Interestingly, nesfatins eliminate the strong positive effect that ghrelin has on GH synthesis and secretion. Throughout this review, we will attempt to broadly analyze the role of these hormones in the complex world of GH regulation, a world in which these hormones already play a very important role.
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Affiliation(s)
- Jesús Devesa
- Scientific and Medical Direction, Medical Center Foltra, Teo, Spain
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4
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Mani BK, Osborne-Lawrence S, Metzger N, Zigman JM. Lowering oxidative stress in ghrelin cells stimulates ghrelin secretion. Am J Physiol Endocrinol Metab 2020; 319:E330-E337. [PMID: 32543942 PMCID: PMC7473909 DOI: 10.1152/ajpendo.00119.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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 is a predominantly stomach-derived peptide hormone with many actions including regulation of food intake, body weight, and blood glucose. Plasma ghrelin levels are robustly regulated by feeding status, with its levels increasing upon caloric restriction and decreasing after food intake. At least some of this regulation might be due to direct responsiveness of ghrelin cells to changes in circulating nutrients, including glucose. Indeed, oral and parental glucose administration to humans and mice lower plasma ghrelin. Also, dissociated mouse gastric mucosal cell preparations, which contain ghrelin cells, decrease ghrelin secretion when cultured in high ambient glucose. Here, we used primary cultures of mouse gastric mucosal cells in combination with an array of pharmacological tools to examine the potential role of changed intracellular oxidative stress in glucose-restricted ghrelin secretion. The antioxidants resveratrol, SRT1720, and curcumin all markedly increased ghrelin secretion. Furthermore, three different selective activators of Nuclear factor erythroid-derived-2-like 2 (Nrf2), a master regulator of the antioxidative cellular response to oxidative stress, increased ghrelin secretion. These antioxidant compounds blocked the inhibitory effects of glucose on ghrelin secretion. Therefore, we conclude that lowering oxidative stress within ghrelin cells stimulates ghrelin secretion and blocks the direct effects of glucose on ghrelin cells to inhibit ghrelin secretion.
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Affiliation(s)
- Bharath K Mani
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Nathan Metzger
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jeffrey M Zigman
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
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5
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Nakato J, Aoki H, Tokuyama Y, Yamamoto Y, Iwakura H, Matsumura S, Inoue K, Ohinata K. Comprehensive analysis of a dipeptide library to identify ghrelin release-modulating peptides. FEBS Lett 2019; 593:2637-2645. [PMID: 31254351 DOI: 10.1002/1873-3468.13522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/20/2019] [Accepted: 06/27/2019] [Indexed: 12/28/2022]
Abstract
We performed a comprehensive analysis of ghrelin release-modulating activity of a dipeptide library using MGN3-1, a ghrelin-producing cell line. We found that most dipeptides suppress ghrelin secretion, whereas the N-terminal Ser-containing dipeptides and a few others stimulate it. N-terminal amino acid residues, but not C-terminal residues, play a dominant role in the effects of dipeptides. Among dipeptides, Leu-Ile (LI) and Ser-Val (SV) most strongly suppress and stimulate ghrelin secretion, respectively. LI activates Gi signaling and SV acts via the MAPK pathway. Orally administered LI and SV reduce and increase plasma ghrelin levels and food intake in mice, respectively. In conclusion, LI and SV, found based on the comprehensive screening of a dipeptide library, modulate ghrelin secretion in vitro and in vivo.
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Affiliation(s)
- Junya Nakato
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Hayato Aoki
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Yuki Tokuyama
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Yuta Yamamoto
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Hiroshi Iwakura
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Shigenobu Matsumura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Kazuo Inoue
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Kousaku Ohinata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
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6
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Mani BK, Shankar K, Zigman JM. Ghrelin's Relationship to Blood Glucose. Endocrinology 2019; 160:1247-1261. [PMID: 30874792 PMCID: PMC6482034 DOI: 10.1210/en.2019-00074] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/09/2019] [Indexed: 12/16/2022]
Abstract
Much effort has been directed at studying the orexigenic actions of administered ghrelin and the potential effects of the endogenous ghrelin system on food intake, food reward, body weight, adiposity, and energy expenditure. Although endogenous ghrelin's actions on some of these processes remain ambiguous, its glucoregulatory actions have emerged as well-recognized features during extreme metabolic conditions. The blood glucose-raising actions of ghrelin are beneficial during starvation-like conditions, defending against life-threatening falls in blood glucose, but they are seemingly detrimental in obese states and in certain monogenic forms of diabetes, contributing to hyperglycemia. Also of interest, blood glucose negatively regulates ghrelin secretion. This article reviews the literature suggesting the existence of a blood glucose-ghrelin axis and highlights the factors that mediate the glucoregulatory actions of ghrelin, especially during metabolic extremes such as starvation and diabetes.
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Affiliation(s)
- Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Kripa Shankar
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
- Correspondence: Jeffrey M. Zigman, MD, PhD, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390. E-mail:
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7
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Li W, Chang M, Qiu M, Chen Y, Zhang X, Li Q, Cui C. Exogenous obestatin decreases beta-cell apoptosis and alfa-cell proliferation in high fat diet and streptozotocin induced type 2 diabetic rats. Eur J Pharmacol 2019; 851:36-42. [PMID: 30776368 DOI: 10.1016/j.ejphar.2019.02.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 12/31/2022]
Abstract
Type 2 diabetes is a chronic metabolic disease characterized by progressive decrease of islet cell function. Delaying the process of islet failure remains a challenging goal in diabetes care. Previous studies have confirmed the role of obestatin, a gut peptide that belongs to ghrelin family, in the mediation of glucose metabolism. This study aimed to observe the long term effects of exogenous obestatin on glucose metabolism in type 2 diabetes rat model. Type 2 diabetic rat model was set up by high-fat diet (60%) followed by a low dose of streptozotocin intra-peritoneal injection. Exogenous obestatin was administered at a dose of 20 nmol/kg for 12 weeks by intraperitoneal injection. Compared to placebo group (saline intraperitoneal injection), obestatin treatment decreased the glucagon levels and increased the c-peptide levels. Furthermore, obestatin treatment led to a significant restoration of islet morphology, increasing insulin and reducing glucagon expressions. Apoptosis assay showed a reduction in the number of TUNEL positive-cells. The up-regulation of Akt and GSK3β in pancreas was confirmed by Real-Time PCR. These results demonstrated that obestatin might have a potential therapeutic relevance in improving islet cell function, including increasing insulin secretion through inhibiting beta cell apoptosis and decreasing glucagon secretion by inhibiting alfa cell proliferation in type 2 diabetes. In spite of its role in these phenomena, it is necessary to further discuss, especially regarding the role of obestatin on glucagon.
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Affiliation(s)
- Wensong Li
- Department of Infectious Disease, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Manli Chang
- Department of Laboratory Medicine, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Mingli Qiu
- Department of Endocrinology and Metabolism, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Yangli Chen
- Department of Endocrinology and Metabolism, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Xiaochen Zhang
- Department of Endocrinology and Metabolism, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Qiang Li
- Department of Endocrinology and Metabolism, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Can Cui
- Department of Endocrinology and Metabolism, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China.
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Bai J, Jiang X, He M, Chan BCB, Wong AOL. Novel Mechanisms for IGF-I Regulation by Glucagon in Carp Hepatocytes: Up-Regulation of HNF1α and CREB Expression via Signaling Crosstalk for IGF-I Gene Transcription. Front Endocrinol (Lausanne) 2019; 10:605. [PMID: 31551932 PMCID: PMC6734168 DOI: 10.3389/fendo.2019.00605] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/20/2019] [Indexed: 12/13/2022] Open
Abstract
Glucagon, a key hormone for glucose homeostasis, can exert functional crosstalk with somatotropic axis via modification of IGF-I expression. However, its effect on IGF-I regulation is highly variable in different studies and the mechanisms involved are largely unknown. Using grass carp as a model, the signal transduction and transcriptional mechanisms for IGF-I regulation by glucagon were examined in Cyprinid species. As a first step, the carp HNF1α, a liver-enriched transcription factor, was cloned and confirmed to be a single-copy gene expressed in the liver. In grass carp hepatocytes, glucagon treatment could elevate IGF-I, HNF1α, and CREB mRNA levels, induce CREB phosphorylation, and up-regulate HNF1α and CREB protein expression. The effects on IGF-I, HNF1α, and CREB gene expression were mediated by cAMP/PKA and PLC/IP3/PKC pathways with differential coupling with the MAPK and PI3K/Akt cascades. During the process, protein:protein interaction between HNF1α and CREB and recruitment of RNA Pol-II to IGF-I promoter also occurred with a rise in IGF-I primary transcript level. In parallel study to examine grass carp IGF-I promoter activity expressed in αT3 cells, similar pathways for post-receptor signaling were also confirmed in glucagon-induced IGF-I promoter activation and the trans-activating effect by glucagon was mediated by the binding sites for HNF1α and CREB located in the proximal region of IGF-I promoter. Our findings, as a whole, shed light on a previously undescribed mechanism for glucagon-induced IGF-I gene expression by increasing HNF1α and CREB production via functional crosstalk of post-receptor signaling. Probably, by protein:protein interaction between the two transcription factors and subsequent transactivation via their respective cis-acting elements in the IGF-I promoter, IGF-I gene transcription can be initiated by glucagon at the hepatic level.
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10
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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11
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Yagi T, Kubota E, Koyama H, Tanaka T, Kataoka H, Imaeda K, Joh T. Glucagon promotes colon cancer cell growth via regulating AMPK and MAPK pathways. Oncotarget 2018. [PMID: 29535833 PMCID: PMC5828215 DOI: 10.18632/oncotarget.24367] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cancer is one of the major causes of death in diabetic patients, and an association between antidiabetic drugs and cancer risk has been reported. Such evidence implies a strong connection between diabetes and cancer. Recently, glucagon has been recognized as a pivotal factor implicated in the pathophysiology of diabetes. Glucagon acts through binding to its receptor, glucagon receptor (GCGR), and cross-talk between GCGR-mediated signals and signaling pathways that regulate cancer cell fate has been unveiled. In the current study, expression of GCGR in colon cancer cell lines and colon cancer tissue obtained from patients was demonstrated. Glucagon significantly promoted colon cancer cell growth, and GCGR knockdown with small interfering RNA attenuated the proliferation-promoting effect of glucagon on colon cancer cells. Molecular assays showed that glucagon acted as an activator of cancer cell growth through deactivation of AMPK and activation of MAPK in a GCGR-dependent manner. Moreover, a stable GCGR knockdown mouse colon cancer cell line, CMT93, grew significantly slower than control in a syngeneic mouse model of type 2 diabetes with glycemia and hyperglucagonemia. The present observations provide experimental evidence that hyperglucagonemia in type 2 diabetes promotes colon cancer progression via GCGR-mediated regulation of AMPK and MAPK pathways.
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Affiliation(s)
- Takashi Yagi
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
| | - Eiji Kubota
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
| | - Hiroyuki Koyama
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
| | - Tomohiro Tanaka
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
| | - Hiromi Kataoka
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
| | - Kenro Imaeda
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
| | - Takashi Joh
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya 467-8601, Japan
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12
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PACAP signaling in stress: insights from the chromaffin cell. Pflugers Arch 2017; 470:79-88. [PMID: 28965274 DOI: 10.1007/s00424-017-2062-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 10/18/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) was first identified in hypothalamus, based on its ability to elevate cyclic AMP in the anterior pituitary. PACAP has been identified as the adrenomedullary neurotransmitter in stress through a combination of ex vivo, in vivo, and in cellula experiments over the past two decades. PACAP causes catecholamine secretion, and activation of catecholamine biosynthetic enzymes, during episodes of stress in mammals. Features of PACAP signaling allowing stress transduction at the splanchnicoadrenomedullary synapse have yielded insights into the contrasting roles of acetylcholine's and PACAP's actions as first messengers at the chromaffin cell, via differential release at low and high rates of splanchnic nerve firing, and differential signaling pathway engagement leading to catecholamine secretion and chromaffin cell gene transcription. Secretion stimulated by PACAP, via calcium influx independent of action potential generation, is under active investigation in several laboratories both at the chromaffin cell and within autonomic ganglia of both the parasympathetic and sympathetic nervous systems. PACAP is a neurotransmitter important in stress transduction in the central nervous system as well, and is found at stress-transduction nuclei in brain including the paraventricular nucleus of hypothalamus, the amygdala and extended amygdalar nuclei, and the prefrontal cortex. The current status of PACAP as a master regulator of stress signaling in the nervous system derives fundamentally from the establishment of its role as the splanchnicoadrenomedullary transmitter in stress. Experimental elucidation of PACAP action at this synapse remains at the forefront of understanding PACAP's role in stress signaling throughout the nervous system.
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13
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Mani BK, Uchida A, Lee Y, Osborne-Lawrence S, Charron MJ, Unger RH, Berglund ED, Zigman JM. Hypoglycemic Effect of Combined Ghrelin and Glucagon Receptor Blockade. Diabetes 2017; 66:1847-1857. [PMID: 28487437 PMCID: PMC5482080 DOI: 10.2337/db16-1303] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 04/19/2017] [Indexed: 12/18/2022]
Abstract
Glucagon receptor (GcgR) blockade has been proposed as an alternative to insulin monotherapy for treating type 1 diabetes since deletion or inhibition of GcgRs corrects hyperglycemia in models of diabetes. The factors regulating glycemia in a setting devoid of insulin and glucagon function remain unclear but may include the hormone ghrelin. Not only is ghrelin release controlled by glucose but also ghrelin has many actions that can raise or reduce falls in blood glucose level. Here, we tested the hypothesis that ghrelin rises to prevent hypoglycemia in the absence of glucagon function. Both GcgR knockout (Gcgr-/-) mice and db/db mice that were administered GcgR monoclonal antibody displayed lower blood glucose levels accompanied by elevated plasma ghrelin levels. Although treatment with the pancreatic β-cell toxin streptozotocin induced hyperglycemia and raised plasma ghrelin levels in wild-type mice, hyperglycemia was averted in similarly treated Gcgr-/- mice and the plasma ghrelin level was further increased. Notably, administration of a ghrelin receptor antagonist further reduced blood glucose levels into the markedly hypoglycemic range in overnight-fasted, streptozotocin-treated Gcgr-/- mice. A lowered blood glucose level also was observed in overnight-fasted, streptozotocin-treated ghrelin receptor-null mice that were administered GcgR monoclonal antibody. These data suggest that when glucagon activity is blocked in the setting of type 1 diabetes, the plasma ghrelin level rises, preventing hypoglycemia.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Atenolol/pharmacology
- Blood Glucose/drug effects
- Blood Glucose/metabolism
- Cells, Cultured
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/metabolism
- Gastric Mucosa/metabolism
- Ghrelin/metabolism
- Immunohistochemistry
- Insulin/metabolism
- Mice
- Mice, Knockout
- Oligopeptides/pharmacology
- Real-Time Polymerase Chain Reaction
- Receptors, Ghrelin/antagonists & inhibitors
- Receptors, Glucagon/antagonists & inhibitors
- Receptors, Glucagon/genetics
- Receptors, Leptin/genetics
- Sympatholytics/pharmacology
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Affiliation(s)
- Bharath K Mani
- Divisions of Hypothalamic Research and Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Aki Uchida
- Advanced Imaging Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Young Lee
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Sherri Osborne-Lawrence
- Divisions of Hypothalamic Research and Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Maureen J Charron
- Departments of Biochemistry, Obstetrics and Gynecology and Woman's Health, and Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Roger H Unger
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Eric D Berglund
- Advanced Imaging Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jeffrey M Zigman
- Divisions of Hypothalamic Research and Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
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14
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Yan AF, Chen T, Chen S, Tang DS, Liu F, Jiang X, Huang W, Ren CH, Hu CQ. Signal transduction mechanism for glucagon-induced leptin gene expression in goldfish liver. Int J Biol Sci 2016; 12:1544-1554. [PMID: 27994518 PMCID: PMC5166495 DOI: 10.7150/ijbs.16612] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/12/2016] [Indexed: 12/24/2022] Open
Abstract
Leptin is a peripheral satiety hormone that also plays important roles in energy homeostasis in vertebrates ranging from fish to mammals. In teleost fish, however, the regulatory mechanism for leptin gene expression still remains unclear. In this study, we found that glucagon, a key hormone in glucose homeostasis, was effective at elevating the leptin-AI and leptin-AII transcript levels in goldfish liver via both in vivo intraperitoneal injection and in vitro cells incubation approaches. The responses of leptin-AI and leptin-AII mRNA to glucagon treatment were highly comparable. In contrast, blockade of local glucagon action could reduce the basal and induced leptin-AI and leptin-AII mRNA expression. The stimulation of leptin levels by glucagon was caused by the activation of adenylate cyclase (AC)/cyclic-AMP (cAMP)/ protein kinase A (PKA), and probably cAMP response element-binding protein (CREB) cascades. Our study described the effect and signal transduction mechanism of glucagon on leptin gene expression in goldfish liver, and may also provide new insight into leptin as a mediator in the regulatory network of energy metabolism in the fish model.
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Affiliation(s)
- Ai-Fen Yan
- School of stomatology and medicine, Foshan University, Foshan 528000, China
| | - Ting Chen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China
| | - Shuang Chen
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Dong-Sheng Tang
- School of stomatology and medicine, Foshan University, Foshan 528000, China
| | - Fang Liu
- School of stomatology and medicine, Foshan University, Foshan 528000, China
| | - Xiao Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB)
| | - Wen Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB)
| | - Chun-Hua Ren
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China
| | - Chao-Qun Hu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China
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15
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Nakato J, Aoki H, Iwakura H, Suzuki H, Kanamoto R, Ohinata K. Soy-ghretropin, a novel ghrelin-releasing peptide derived from soy protein. FEBS Lett 2016; 590:2681-9. [DOI: 10.1002/1873-3468.12306] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Junya Nakato
- Division of Food Science and Biotechnology; Graduate School of Agriculture; Kyoto University; Uji Japan
| | - Hayato Aoki
- Division of Food Science and Biotechnology; Graduate School of Agriculture; Kyoto University; Uji Japan
| | - Hiroshi Iwakura
- Medical Innovation Center; Kyoto University Graduate School of Medicine; Japan
| | | | - Ryuhei Kanamoto
- Division of Food Science and Biotechnology; Graduate School of Agriculture; Kyoto University; Uji Japan
| | - Kousaku Ohinata
- Division of Food Science and Biotechnology; Graduate School of Agriculture; Kyoto University; Uji Japan
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16
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Abstract
Ghrelin is a growth hormone-releasing polypeptide that was first isolated from the rat stomach in 1999. High expression of growth hormone secretagogue receptor, the ghrelin receptor, in the heart, kidney, and blood vessels provides evidence of ghrelin activity in blood pressure regulation. Circulating ghrelin concentrations are reported to be inversely correlated with blood pressure, and the acute and chronic effects of ghrelin in decreasing blood pressure have been reported in animals with normal blood pressure, healthy individuals, animals and patients with heart failure, and animals with hypertension. The mechanism by which ghrelin regulates blood pressure appears to be related to modulation of the autonomic nervous system, direct vasodilatory activities, and kidney diuresis. Thus, modulation of the signaling pathway through ghrelin may provide a novel concept for treating hypertension. In this review, we discuss the current evidence and potential mechanisms of ghrelin activity in blood pressure regulation.
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17
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Koyama H, Iwakura H, Dote K, Bando M, Hosoda H, Ariyasu H, Kusakabe T, Son C, Hosoda K, Akamizu T, Kangawa K, Nakao K. Comprehensive Profiling of GPCR Expression in Ghrelin-Producing Cells. Endocrinology 2016; 157:692-704. [PMID: 26671185 DOI: 10.1210/en.2015-1784] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
To determine the comprehensive G protein-coupled receptor (GPCR) expression profile in ghrelin-producing cells and to elucidate the role of GPCR-mediated signaling in the regulation of ghrelin secretion, we determined GPCR expression profiles by RNA sequencing in the ghrelin-producing cell line MGN3-1 and analyzed the effects of ligands for highly expressed receptors on intracellular signaling and ghrelin secretion. Expression of selected GPCRs was confirmed in fluorescence-activated cell-sorted fluorescently tagged ghrelin-producing cells from ghrelin-promoter CreERT2/Rosa-CAG-LSL-ZsGreen1 mice. Expression levels of GPCRs previously suggested to regulate ghrelin secretion including adrenergic-β1 receptor, GPR81, oxytocin receptor, GPR120, and somatostatin receptor 2 were high in MGN3-1 cells. Consistent with previous reports, isoproterenol and oxytocin stimulated the Gs and Gq pathways, respectively, whereas lactate, palmitate, and somatostatin stimulated the Gi pathway, confirming the reliability of current assays. Among other highly expressed GPCRs, prostaglandin E receptor 4 agonist prostaglandin E2 significantly stimulated the Gs pathway and ghrelin secretion. Muscarine, the canonical agonist of cholinergic receptor muscarinic 4, stimulated both the Gq and Gi pathways. Although muscarine treatment alone did not affect ghrelin secretion, it did suppress forskolin-induced ghrelin secretion, suggesting that the cholinergic pathway may play a role in counterbalancing the stimulation of ghrelin by Gs (eg, by adrenaline). In addition, GPR142 ligand tryptophan stimulated ghrelin secretion. In conclusion, we determined the comprehensive expression profile of GPCRs in ghrelin-producing cells and identified two novel ghrelin regulators, prostaglandin E2 and tryptophan. These results will lead to a greater understanding of the physiology of ghrelin and facilitate the development of ghrelin-modulating drugs.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Cell Line, Tumor
- Colforsin/pharmacology
- Dinoprostone/pharmacology
- Gastric Mucosa/cytology
- Gastric Mucosa/drug effects
- Gastric Mucosa/metabolism
- Gene Expression Profiling
- Ghrelin/drug effects
- Ghrelin/metabolism
- Hormones/pharmacology
- Immunohistochemistry
- Isoproterenol/pharmacology
- Lactic Acid/pharmacology
- Mice
- Mice, Transgenic
- Muscarine/pharmacology
- Muscarinic Agonists/pharmacology
- Oxytocics/pharmacology
- Oxytocin/pharmacology
- Palmitates/pharmacology
- RNA, Messenger/metabolism
- Receptor, Muscarinic M4/agonists
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Oxytocin/drug effects
- Receptors, Oxytocin/genetics
- Receptors, Oxytocin/metabolism
- Receptors, Prostaglandin E, EP4 Subtype/agonists
- Receptors, Somatostatin/drug effects
- Receptors, Somatostatin/genetics
- Receptors, Somatostatin/metabolism
- Sequence Analysis, RNA
- Somatostatin/pharmacology
- Tryptophan/pharmacology
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Affiliation(s)
- Hiroyuki Koyama
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Hiroshi Iwakura
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Katsuko Dote
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Mika Bando
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Hiroshi Hosoda
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Hiroyuki Ariyasu
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Toru Kusakabe
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Choel Son
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Kiminori Hosoda
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Takashi Akamizu
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Kenji Kangawa
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Kazuwa Nakao
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
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18
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Ibrahim Abdalla MM. Ghrelin - Physiological Functions and Regulation. EUROPEAN ENDOCRINOLOGY 2015; 11:90-95. [PMID: 29632576 DOI: 10.17925/ee.2015.11.02.90] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 07/13/2015] [Indexed: 01/01/2023]
Abstract
Ghrelin is an orexigenic peptide predominantly secreted from the stomach and stimulates appetite and growth hormone (GH) release. Studies have provided evidence that ghrelin exercises a wide range of functions, including regulation of food intake and energy metabolism, modulation of cardiovascular function, stimulation of osteoblast proliferation and bone formation and stimulation of neurogenesis and myogenesis. In the gastrointestinal system, ghrelin affects multiple functions, including secretion of gastric acid, gastric motility and pancreatic protein output. Most of these functions have been attributed to the actions of acylated ghrelin. The balance among its secretion rate, degradation rate and clearance rate determines the circulating level of ghrelin. This review explains what ghrelin is, its physiological functions and the factors that influence its level.
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19
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Müller TD, Nogueiras R, Andermann ML, Andrews ZB, Anker SD, Argente J, Batterham RL, Benoit SC, Bowers CY, Broglio F, Casanueva FF, D'Alessio D, Depoortere I, Geliebter A, Ghigo E, Cole PA, Cowley M, Cummings DE, Dagher A, Diano S, Dickson SL, Diéguez C, Granata R, Grill HJ, Grove K, Habegger KM, Heppner K, Heiman ML, Holsen L, Holst B, Inui A, Jansson JO, Kirchner H, Korbonits M, Laferrère B, LeRoux CW, Lopez M, Morin S, Nakazato M, Nass R, Perez-Tilve D, Pfluger PT, Schwartz TW, Seeley RJ, Sleeman M, Sun Y, Sussel L, Tong J, Thorner MO, van der Lely AJ, van der Ploeg LHT, Zigman JM, Kojima M, Kangawa K, Smith RG, Horvath T, Tschöp MH. Ghrelin. Mol Metab 2015; 4:437-60. [PMID: 26042199 PMCID: PMC4443295 DOI: 10.1016/j.molmet.2015.03.005] [Citation(s) in RCA: 702] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/11/2015] [Accepted: 03/11/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The gastrointestinal peptide hormone ghrelin was discovered in 1999 as the endogenous ligand of the growth hormone secretagogue receptor. Increasing evidence supports more complicated and nuanced roles for the hormone, which go beyond the regulation of systemic energy metabolism. SCOPE OF REVIEW In this review, we discuss the diverse biological functions of ghrelin, the regulation of its secretion, and address questions that still remain 15 years after its discovery. MAJOR CONCLUSIONS In recent years, ghrelin has been found to have a plethora of central and peripheral actions in distinct areas including learning and memory, gut motility and gastric acid secretion, sleep/wake rhythm, reward seeking behavior, taste sensation and glucose metabolism.
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Affiliation(s)
- T D Müller
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, München, Germany
| | - R Nogueiras
- Department of Physiology, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, University of Santiago de Compostela (CIMUS)-Instituto de Investigación Sanitaria (IDIS)-CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - M L Andermann
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Z B Andrews
- Department of Physiology, Faculty of Medicine, Monash University, Melbourne, Victoria, Australia
| | - S D Anker
- Applied Cachexia Research, Department of Cardiology, Charité Universitätsmedizin Berlin, Germany
| | - J Argente
- Department of Pediatrics and Pediatric Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain ; Department of Pediatrics, Universidad Autónoma de Madrid and CIBER Fisiopatología de la obesidad y nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - R L Batterham
- Centre for Obesity Research, University College London, London, United Kingdom
| | - S C Benoit
- Metabolic Disease Institute, Division of Endocrinology, Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - C Y Bowers
- Tulane University Health Sciences Center, Endocrinology and Metabolism Section, Peptide Research Section, New Orleans, LA, USA
| | - F Broglio
- Division of Endocrinology, Diabetes and Metabolism, Dept. of Medical Sciences, University of Torino, Torino, Italy
| | - F F Casanueva
- Department of Medicine, Santiago de Compostela University, Complejo Hospitalario Universitario de Santiago (CHUS), CIBER de Fisiopatologia Obesidad y Nutricion (CB06/03), Instituto Salud Carlos III, Santiago de Compostela, Spain
| | - D D'Alessio
- Duke Molecular Physiology Institute, Duke University, Durham, NC, USA
| | - I Depoortere
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - A Geliebter
- New York Obesity Nutrition Research Center, Department of Medicine, St Luke's-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - E Ghigo
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - P A Cole
- Monash Obesity & Diabetes Institute, Monash University, Clayton, Victoria, Australia
| | - M Cowley
- Department of Physiology, Faculty of Medicine, Monash University, Melbourne, Victoria, Australia ; Monash Obesity & Diabetes Institute, Monash University, Clayton, Victoria, Australia
| | - D E Cummings
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - A Dagher
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - S Diano
- Dept of Neurobiology, Yale University School of Medicine, New Haven, CT, USA
| | - S L Dickson
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - C Diéguez
- Department of Physiology, School of Medicine, Instituto de Investigacion Sanitaria (IDIS), University of Santiago de Compostela, Spain
| | - R Granata
- Division of Endocrinology, Diabetes and Metabolism, Dept. of Medical Sciences, University of Torino, Torino, Italy
| | - H J Grill
- Department of Psychology, Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania, Philadelphia, PA, USA
| | - K Grove
- Department of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - K M Habegger
- Comprehensive Diabetes Center, University of Alabama School of Medicine, Birmingham, AL, USA
| | - K Heppner
- Division of Diabetes, Obesity, and Metabolism, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA
| | - M L Heiman
- NuMe Health, 1441 Canal Street, New Orleans, LA 70112, USA
| | - L Holsen
- Departments of Psychiatry and Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - B Holst
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark
| | - A Inui
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - J O Jansson
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - H Kirchner
- Medizinische Klinik I, Universitätsklinikum Schleswig-Holstein Campus Lübeck, Lübeck, Germany
| | - M Korbonits
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London, Queen Mary University of London, London, UK
| | - B Laferrère
- New York Obesity Research Center, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - C W LeRoux
- Diabetes Complications Research Centre, Conway Institute, University College Dublin, Ireland
| | - M Lopez
- Department of Physiology, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, University of Santiago de Compostela (CIMUS)-Instituto de Investigación Sanitaria (IDIS)-CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - S Morin
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, München, Germany
| | - M Nakazato
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan
| | - R Nass
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| | - D Perez-Tilve
- Department of Internal Medicine, Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - P T Pfluger
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, München, Germany
| | - T W Schwartz
- Department of Neuroscience and Pharmacology, Laboratory for Molecular Pharmacology, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - R J Seeley
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - M Sleeman
- Department of Physiology, Faculty of Medicine, Monash University, Melbourne, Victoria, Australia
| | - Y Sun
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - L Sussel
- Department of Genetics and Development, Columbia University, New York, NY, USA
| | - J Tong
- Duke Molecular Physiology Institute, Duke University, Durham, NC, USA
| | - M O Thorner
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| | - A J van der Lely
- Department of Medicine, Erasmus University MC, Rotterdam, The Netherlands
| | | | - J M Zigman
- Departments of Internal Medicine and Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - M Kojima
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Japan
| | - K Kangawa
- National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - R G Smith
- The Scripps Research Institute, Florida Department of Metabolism & Aging, Jupiter, FL, USA
| | - T Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - M H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, München, Germany ; Division of Metabolic Diseases, Department of Medicine, Technical University Munich, Munich, Germany
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20
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Iwakura H, Kangawa K, Nakao K. The regulation of circulating ghrelin - with recent updates from cell-based assays. Endocr J 2015; 62:107-22. [PMID: 25273611 DOI: 10.1507/endocrj.ej14-0419] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Ghrelin is a stomach-derived orexigenic hormone with a wide range of physiological functions. Elucidation of the regulation of the circulating ghrelin level would lead to a better understanding of appetite control in body energy homeostasis. Earlier studies revealed that circulating ghrelin levels are under the control of both acute and chronic energy status: at the acute scale, ghrelin levels are increased by fasting and decreased by feeding, whereas at the chronic scale, they are high in obese subjects and low in lean subjects. Subsequent studies revealed that nutrients, hormones, or neural activities can influence circulating ghrelin levels in vivo. Recently developed in vitro assay systems for ghrelin secretion can assess whether and how individual factors affect ghrelin secretion from cells. In this review, on the basis of numerous human, animal, and cell-based studies, we summarize current knowledge on the regulation of circulating ghrelin levels and enumerate the factors that influence ghrelin levels.
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Affiliation(s)
- Hiroshi Iwakura
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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21
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Uchida A, Zechner JF, Mani BK, Park WM, Aguirre V, Zigman JM. Altered ghrelin secretion in mice in response to diet-induced obesity and Roux-en-Y gastric bypass. Mol Metab 2014; 3:717-30. [PMID: 25353000 PMCID: PMC4209356 DOI: 10.1016/j.molmet.2014.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/22/2014] [Accepted: 07/25/2014] [Indexed: 01/06/2023] Open
Abstract
The current study examined potential mechanisms for altered circulating ghrelin levels observed in diet-induced obesity (DIO) and following weight loss resulting from Roux-en-Y gastric bypass (RYGB). We hypothesized that circulating ghrelin levels were altered in obesity and after weight loss through changes in ghrelin cell responsiveness to physiological cues. We confirmed lower ghrelin levels in DIO mice and demonstrated elevated ghrelin levels in mice 6 weeks post-RYGB. In both DIO and RYGB settings, these changes in ghrelin levels were associated with altered ghrelin cell responsiveness to two key physiological modulators of ghrelin secretion - glucose and norepinephrine. In DIO mice, increases in ghrelin cell density within both the stomach and duodenum and in somatostatin-immunoreactive D cell density in the duodenum were observed. Our findings provide new insights into the regulation of ghrelin secretion and its relation to circulating ghrelin within the contexts of obesity and weight loss.
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Affiliation(s)
- Aki Uchida
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Juliet F Zechner
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Digestive and Liver Diseases, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Won-Mee Park
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vincent Aguirre
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Digestive and Liver Diseases, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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22
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Mani BK, Chuang JC, Kjalarsdottir L, Sakata I, Walker AK, Kuperman A, Osborne-Lawrence S, Repa JJ, Zigman JM. Role of calcium and EPAC in norepinephrine-induced ghrelin secretion. Endocrinology 2014; 155:98-107. [PMID: 24189139 PMCID: PMC3868802 DOI: 10.1210/en.2013-1691] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [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 an orexigenic hormone secreted principally from a distinct population of gastric endocrine cells. Molecular mechanisms regulating ghrelin secretion are mostly unknown. Recently, norepinephrine (NE) was shown to enhance ghrelin release by binding to β1-adrenergic receptors on ghrelin cells. Here, we use an immortalized stomach-derived ghrelin cell line to further characterize the intracellular signaling pathways involved in NE-induced ghrelin secretion, with a focus on the roles of Ca(2+) and cAMP. Several voltage-gated Ca(2+) channel (VGCC) family members were found by quantitative PCR to be expressed by ghrelin cells. Nifedipine, a selective L-type VGCC blocker, suppressed both basal and NE-stimulated ghrelin secretion. NE induced elevation of cytosolic Ca(2+) levels both in the presence and absence of extracellular Ca(2+). Ca(2+)-sensing synaptotagmins Syt7 and Syt9 were also highly expressed in ghrelin cell lines, suggesting that they too help mediate ghrelin secretion. Raising cAMP with the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine also stimulated ghrelin secretion, although such a cAMP-mediated effect likely does not involve protein kinase A, given the absence of a modulatory response to a highly selective protein kinase A inhibitor. However, pharmacological inhibition of another target of cAMP, exchange protein-activated by cAMP (EPAC), did attenuate both basal and NE-induced ghrelin secretion, whereas an EPAC agonist enhanced basal ghrelin secretion. We conclude that constitutive ghrelin secretion is primarily regulated by Ca(2+) influx through L-type VGCCs and that NE stimulates ghrelin secretion predominantly through release of intracellular Ca(2+). Furthermore, cAMP and its downstream activation of EPAC are required for the normal ghrelin secretory response to NE.
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Affiliation(s)
- Bharath K Mani
- Division of Endocrinology and Metabolism (B.K.M., J.-C.C., I.S., A.K.W., A.K., S.O.-L., J.M.Z.), Department of Internal Medicine; Division of Hypothalamic research (B.K.M., J.-C.C., L.K., I.S., A.K.W., A.K., S.O.-L., J.J.R., J.M.Z.), Department of Internal Medicine; and Departments of Psychiatry (B.K.M., J.-C.C., I.S., A.K.W., A.K., S.O.-L., J.M.Z.) and Physiology (L.K., J.J.R.), University of Texas Southwestern Medical Center, Dallas, Texas 75390
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23
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Oral 'hydrogen water' induces neuroprotective ghrelin secretion in mice. Sci Rep 2013; 3:3273. [PMID: 24253616 PMCID: PMC4070541 DOI: 10.1038/srep03273] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 11/01/2013] [Indexed: 02/07/2023] Open
Abstract
The therapeutic potential of molecular hydrogen (H2) is emerging in a number of human diseases and in their animal models, including in particular Parkinson's disease (PD). H2 supplementation of drinking water has been shown to exert disease-modifying effects in PD patients and neuroprotective effects in experimental PD model mice. However, H2 supplementation does not result in detectable changes in striatal H2 levels, indicating an indirect effect. Here we show that H2 supplementation increases gastric expression of mRNA encoding ghrelin, a growth hormone secretagogue, and ghrelin secretion, which are antagonized by the β1-adrenoceptor blocker, atenolol. Strikingly, the neuroprotective effect of H2 water was abolished by either administration of the ghrelin receptor-antagonist, D-Lys3 GHRP-6, or atenolol. Thus, the neuroprotective effect of H2 in PD is mediated by enhanced production of ghrelin. Our findings point to potential, novel strategies for ameliorating pathophysiology in which a protective effect of H2 supplementation has been demonstrated.
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Abstract
PURPOSE OF REVIEW Ghrelin is a multifaceted gut hormone that activates its receptor, growth hormone secretagogue receptor (GHS-R). Ghrelin's hallmark functions are its stimulatory effects on growth hormone release, food intake and fat deposition. Ghrelin is famously known as the 'hunger hormone'. However, ample recent literature indicates that the functions of ghrelin go well beyond its role as an orexigenic signal. Here, we have reviewed some of the most recent findings on ghrelin and its signalling in animals and humans. RECENT FINDINGS Ghrelin regulates glucose homeostasis by inhibiting insulin secretion and regulating gluconeogenesis/glycogenolysis. Ghrelin signalling decreases thermogenesis to regulate energy expenditure. Ghrelin improves the survival prognosis of myocardial infarction by reducing sympathetic nerve activity. Ghrelin prevents muscle atrophy by inducing muscle differentiation and fusion. Ghrelin regulates bone formation and metabolism by modulating proliferation and differentiation of osteoblasts. SUMMARY In addition to ghrelin's effects on appetite and adiposity, ghrelin signalling also plays crucial roles in glucose and energy homeostasis, cardioprotection, muscle atrophy and bone metabolism. These multifaceted roles of ghrelin make ghrelin and GHS-R highly attractive targets for drug development. Ghrelin mimetics may be used to treat heart diseases, muscular dystrophy/sarcopenia and osteoporosis; GHS-R antagonists may be used to treat obesity and insulin resistance.
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Affiliation(s)
- Geetali Pradhan
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Susan L. Samson
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Yuxiang Sun
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Huffington Center on Aging, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
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Abstract
PURPOSE OF REVIEW The review summarizes the past year's literature, basic science and clinical, regarding the neural, paracrine, hormonal, and intracellular regulation of gastric acid secretion. RECENT FINDINGS Gastric acid facilitates the digestion of protein as well as the absorption of iron, calcium, vitamin B(12), and certain medications (e.g. thyroxin). It also kills ingested microorganisms and prevents bacterial overgrowth, enteric infection, and possibly spontaneous bacterial peritonitis. Stimulants of acid secretion include histamine, gastrin, acetylcholine, and ghrelin. Inhibitors include somatostatin, nefstatin-1, interleukin-11, and calcitonin gene-related peptide. Helicobacter pylori stimulates or inhibits acid secretion depending upon the time course of infection and the area of the stomach predominantly infected. Acute infection activates calcitonin gene-related peptide sensory neurons coupled to inhibition of histamine and acid secretion. Serum chromogranin A, a marker for neuroendocrine tumors, is elevated in patients taking proton pump inhibitors. SUMMARY Progress continues in our understanding of the regulation of gastric acid secretion in health and disease, as well as the function of gastric neuroendocrine cells. The recognition that gastrin is not only a secretagogue but also a trophic hormone has led to new research into the role of gastrin and its receptor (cholecystokinin-2 receptor) in carcinogenesis and the development of cholecystokinin-2 receptor antagonists.
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Engelstoft MS, Park WM, Sakata I, Kristensen LV, Husted AS, Osborne-Lawrence S, Piper PK, Walker AK, Pedersen MH, Nøhr MK, Pan J, Sinz CJ, Carrington PE, Akiyama TE, Jones RM, Tang C, Ahmed K, Offermanns S, Egerod KL, Zigman JM, Schwartz TW. Seven transmembrane G protein-coupled receptor repertoire of gastric ghrelin cells. Mol Metab 2013; 2:376-92. [PMID: 24327954 DOI: 10.1016/j.molmet.2013.08.006] [Citation(s) in RCA: 239] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 08/26/2013] [Indexed: 12/18/2022] Open
Abstract
The molecular mechanisms regulating secretion of the orexigenic-glucoregulatory hormone ghrelin remain unclear. Based on qPCR analysis of FACS-purified gastric ghrelin cells, highly expressed and enriched 7TM receptors were comprehensively identified and functionally characterized using in vitro, ex vivo and in vivo methods. Five Gαs-coupled receptors efficiently stimulated ghrelin secretion: as expected the β1-adrenergic, the GIP and the secretin receptors but surprisingly also the composite receptor for the sensory neuropeptide CGRP and the melanocortin 4 receptor. A number of Gαi/o-coupled receptors inhibited ghrelin secretion including somatostatin receptors SSTR1, SSTR2 and SSTR3 and unexpectedly the highly enriched lactate receptor, GPR81. Three other metabolite receptors known to be both Gαi/o- and Gαq/11-coupled all inhibited ghrelin secretion through a pertussis toxin-sensitive Gαi/o pathway: FFAR2 (short chain fatty acid receptor; GPR43), FFAR4 (long chain fatty acid receptor; GPR120) and CasR (calcium sensing receptor). In addition to the common Gα subunits three non-common Gαi/o subunits were highly enriched in ghrelin cells: GαoA, GαoB and Gαz. Inhibition of Gαi/o signaling via ghrelin cell-selective pertussis toxin expression markedly enhanced circulating ghrelin. These 7TM receptors and associated Gα subunits constitute a major part of the molecular machinery directly mediating neuronal and endocrine stimulation versus metabolite and somatostatin inhibition of ghrelin secretion including a series of novel receptor targets not previously identified on the ghrelin cell.
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Key Words
- 7TM, seven transmembrane segment
- BAC, bacterial artificial chromosome
- CCK, cholecystokinin
- CFMB, (S)-2-(4-chlorophenyl)-3,3-dimethyl-N-(5-phenylthiazol-2-yl)butamide
- CGRP, calcitonin gene-related peptide
- CHBA, 3-chloro-5-hydroxybenzoic acid
- Enteroendocrine
- G protein signaling
- GIP, glucose-dependent insulinotropic polypeptide
- GLP-1, glucagon-like peptide 1
- GPCR
- Ghrelin
- Metabolites
- PTx, Bordetella pertussis toxin
- PYY, peptide YY
- Secretion
- hrGFP, humanized Renilla reniformis green fluorescent protein
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Affiliation(s)
- Maja S Engelstoft
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology and Enteroendocrinology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark ; Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark
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Expression of Serum Retinol Binding Protein and Transthyretin within Mouse Gastric Ghrelin Cells. PLoS One 2013; 8:e64882. [PMID: 23840311 PMCID: PMC3686803 DOI: 10.1371/journal.pone.0064882] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 04/19/2013] [Indexed: 02/06/2023] Open
Abstract
Ghrelin is an orexigenic peptide hormone produced mainly by a distinct group of dispersed endocrine cells located within the gastric oxyntic mucosa. Besides secreted gene products derived from the preproghrelin gene, which include acyl-ghrelin, desacyl-ghrelin and obestatin, ghrelin cells also synthesize the secreted protein nesfatin-1. The main goal of the current study was to identify other proteins secreted from ghrelin cells. An initial gene chip screen using mRNAs derived from highly enriched pools of mouse gastric ghrelin cells demonstrated high levels of serum retinol-binding protein (RBP4) and transthyretin (TTR), both of which are known to circulate in the bloodstream bound to each other. This high expression was confirmed by quantitative RT-PCR using as template mRNA derived from the enriched gastric ghrelin cell pools and from two ghrelin-producing cell lines (SG-1 and PG-1). RBP4 protein also was shown to be secreted into the culture medium of ghrelin cell lines. Neither acute nor chronic caloric restriction had a significant effect on RBP4 mRNA levels within stomachs of C57BL/6J mice, although both manipulations significantly decreased stomach TTR mRNA levels. In vitro studies using PG-1 cells showed no effect on RBP4 release of octanoic acid, epinephrine or norepinephrine, all of which are known to act directly on ghrelin cells to stimulate ghrelin secretion. These data provide new insights into ghrelin cell physiology, and given the known functions of RBP4 and TTR, support an emerging role for the ghrelin cell in blood glucose handling and metabolism.
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