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Mohr SM, Pra RD, Platt MP, Feketa VV, Shanabrough M, Varela L, Kristant A, Cao H, Merriman DK, Horvath TL, Bagriantsev SN, Gracheva EO. Hypothalamic hormone deficiency enables physiological anorexia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.15.532843. [PMID: 38559054 PMCID: PMC10979886 DOI: 10.1101/2023.03.15.532843] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Mammalian hibernators survive prolonged periods of cold and resource scarcity by temporarily modulating normal physiological functions, but the mechanisms underlying these adaptations are poorly understood. The hibernation cycle of thirteen-lined ground squirrels (Ictidomys tridecemlineatus) lasts for 5-7 months and comprises weeks of hypometabolic, hypothermic torpor interspersed with 24-48-hour periods of an active-like interbout arousal (IBA) state. We show that ground squirrels, who endure the entire hibernation season without food, have negligible hunger during IBAs. These squirrels exhibit reversible inhibition of the hypothalamic feeding center, such that hypothalamic arcuate nucleus neurons exhibit reduced sensitivity to the orexigenic and anorexigenic effects of ghrelin and leptin, respectively. However, hypothalamic infusion of thyroid hormone during an IBA is sufficient to rescue hibernation anorexia. Our results reveal that thyroid hormone deficiency underlies hibernation anorexia and demonstrate the functional flexibility of the hypothalamic feeding center.
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Affiliation(s)
- Sarah M. Mohr
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Rafael Dai Pra
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Maryann P. Platt
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Viktor V. Feketa
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Marya Shanabrough
- Department of Comparative Medicine, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06510, USA
| | - Luis Varela
- Department of Comparative Medicine, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06510, USA
- Achucarro Basque Center for Neuroscience, Leioa, Spain 48940
| | - Ashley Kristant
- Department of Comparative Medicine, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06510, USA
| | - Haoran Cao
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Dana K. Merriman
- Department of Biology, University of Wisconsin-Oshkosh, 800 Algoma Boulevard, Oshkosh, WI 54901, USA
| | - Tamas L. Horvath
- Department of Comparative Medicine, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06510, USA
- Achucarro Basque Center for Neuroscience, Leioa, Spain 48940
| | - Sviatoslav N. Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Elena O. Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
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Zhang RH, Cao SS, Shi Y, Wang X, Shi LL, Zhang YH, Han CJ, Wang B, Feng L, Liu JP. Astragaloside IV-mediated inhibition of oxidative stress by upregulation of ghrelin in type 2 diabetes-induced cognitive impairment. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:2637-2650. [PMID: 37097336 DOI: 10.1007/s00210-023-02486-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 04/04/2023] [Indexed: 04/26/2023]
Abstract
This study is to observe the upregulation effect of astragaloside IV on ghrelin in diabetic cognitive impairment (DCI) rats and to investigate the pathway in prevention and treatment by reducing oxidative stress. The DCI model was induced with streptozotocin (STZ) in conjunction with a high-fat and high-sugar diet and divided into three groups: model, low-dose (40 mg/kg), and high-dose (80 mg/kg) astragaloside IV. After 30 days of gavage, the learning and memory abilities of rats, as well as their body weight and blood glucose levels, were tested using the Morris water maze and then detection of insulin resistance, SOD activity, and serum MDA levels. The whole brain of rats was sampled for hematoxylin-eosin and Nissl staining to observe pathological changes in the hippocampal CA1 region. Immunohistochemistry was used to detect ghrelin expression in the hippocampal CA1 region. A Western blot was used to determine changes in GHS-R1α/AMPK/PGC-1α/UCP2. RT-qPCR was used to determine the levels of ghrelin mRNA. Astragaloside IV reduced nerve damage, increased superoxide dismutase (SOD) activity, decreased MDA levels, and improved insulin resistance. Ghrelin levels and expression increased in serum and hippocampal tissues, and ghrelin mRNA levels increased in rat stomach tissues. According to Western blot, it increased the expression of the ghrelin receptor GHS-R1α and upregulated the mitochondrial function associated-protein AMPK-PGC-1α-UCP2. Astragaloside IV increases ghrelin expression in the brain to reduce oxidative stress and delay diabetes-induced cognitive impairment. It may be related to the promotion of ghrelin mRNA levels.
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Affiliation(s)
- Rui-Hua Zhang
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Shan-Shan Cao
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Yong Shi
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Xin Wang
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Lei-Lei Shi
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Yu-Han Zhang
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Chao-Jun Han
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Bin Wang
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China
| | - Liang Feng
- Key Laboratory of New Drug Delivery System of Chinese Materia Medica, China Pharmaceutical University, 639# Longmian Road, Jiangsu, Nanjing, 210009, People's Republic of China.
| | - Ji-Ping Liu
- Department of Pharmacology, Shaanxi University of Chinese Medicine, No. 1 Middle Section of Century Avenue, Xianyang, 712046, People's Republic of China.
- Key Laboratory of Pharmacodynamic Mechanism and Material Basis of Traditional Chinese Medicine, Shaanxi Administration of Traditional Chinese Medicine, Xianyang, 712046, People's Republic of China.
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Gulubova M, Tolekova A, Berbatov D, Aydogdu N. Development of pancreatic islet cells in the extrahepatic bile ducts of rats with experimentally-induced metabolic syndrome. Arch Physiol Biochem 2023:1-9. [PMID: 37651586 DOI: 10.1080/13813455.2023.2252205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/27/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023]
Abstract
CONTEXT There is data about the existence of some endocrine cells in the epithelial layer of the bile duct in humans and rats. OBJECTIVE We evaluated Ghrelin-, Insulin-, Glucagon- and Somatostatin-positive cells in peribiliary glands, mast cells, and nerve fibres. MATERIALS AND METHODS Wistar rats were used for dietary manipulation with a 15% fructose solution for 12 weeks. Tissue samples were elaborated with immunohistochemistry for Insulin, Glucagon, Ghrelin, and Somatostatin. Glucose and lipid parameters were studied. RESULTS In treated animals, Ghrelin+ and Insulin+ cells in perybiliary glands (PBGs) were significantly increased. In the male fructose group there was a significant increase of the homeostasis model assessment insulin resistance (HOMA-IR). CONCLUSIONS Stem/progenitor cells in extrahepatic bile tree (EHBT) could be a source of Insulin-producing cells in metabolic syndrome. Fructose treatment induces the increase of Ghrelin+ and Insulin+ cells in PBGs and the elevation of Insulin and Ghrelin plasma concentration.
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Affiliation(s)
- Maya Gulubova
- Department of pathology, Trakia University, Stara Zagora, Bulgaria
| | - Anna Tolekova
- Medical College, Trakia University, Stara Zagora, Bulgaria
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Gross JD, Zhou Y, Barak LS, Caron MG. Ghrelin receptor signaling in health and disease: a biased view. Trends Endocrinol Metab 2023; 34:106-118. [PMID: 36567228 PMCID: PMC9852078 DOI: 10.1016/j.tem.2022.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/23/2022] [Accepted: 12/06/2022] [Indexed: 12/25/2022]
Abstract
As allosteric complexes, G-protein-coupled receptors (GPCRs) respond to extracellular stimuli and pleiotropically couple to intracellular transducers to elicit signaling pathway-dependent effects in a process known as biased signaling or functional selectivity. One such GPCR, the ghrelin receptor (GHSR1a), has a crucial role in restoring and maintaining metabolic homeostasis during disrupted energy balance. Thus, pharmacological modulation of GHSR1a bias could offer a promising strategy to treat several metabolism-based disorders. Here, we summarize current evidence supporting GHSR1a functional selectivity in vivo and highlight recent structural data. We propose that precise determinations of GHSR1a molecular pharmacology and pathway-specific physiological effects will enable discovery of GHSR1a drugs with tailored signaling profiles, thereby providing safer and more effective treatments for metabolic diseases.
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Affiliation(s)
- Joshua D Gross
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Yang Zhou
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Lawrence S Barak
- Department of Cell Biology, Duke University, Durham, NC 27710, USA.
| | - Marc G Caron
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
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Wada R, Takemi S, Matsumoto M, Iijima M, Sakai T, Sakata I. Molecular cloning and analysis of the ghrelin/GHSR system in Xenopus tropicalis. Gen Comp Endocrinol 2023; 331:114167. [PMID: 36402245 DOI: 10.1016/j.ygcen.2022.114167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 10/16/2022] [Accepted: 11/12/2022] [Indexed: 11/18/2022]
Abstract
Ghrelin is a gut-derived peptide with several physiological functions, including feeding, gastrointestinal motility, and hormonal secretion. Recently, a host defense peptide, liver-expressed antimicrobial peptide-2 (LEAP2), was reported as an endogenous antagonist of growth hormone secretagogue receptor (GHS-R). The physiological relevance of the molecular LEAP2-GHS-R interaction in mammals has been explored; however, studies on non-mammals are limited. Here, we report the identification and functional characterization of ghrelin and its related molecules in Western clawed frog (Xenopus tropicalis), a known model organism. We first identified cDNA encoding X. tropicalis ghrelin and GHS-R. RT-qPCR revealed that ghrelin mRNA expression was most abundant in the stomach. GHS-R mRNA was widely distributed in the brain and peripheral tissues, and a relatively strong signal was observed in the stomach and intestine. In addition, LEAP2 was mainly expressed in intestinal tissues at higher levels than in the liver. In functional analysis, X. tropicalis ghrelin and human ghrelin induced intracellular Ca2+ mobilization with EC50 values in the low nanomolar range in CHO-K1 cells expressing X. tropicalis GHS-R. Furthermore, ghrelin-induced GHS-R activation was antagonized with IC50 values in the nanomolar range by heterologous human LEAP2. We also validated the expression of ghrelin and feeding-related factors under fasting conditions. After 2 days of fasting, no changes in ghrelin mRNA levels were observed in the stomach, but GHS-R mRNA levels were significantly increased, associated with significant downregulation of nucb2. In addition, LEAP2 upregulation was observed in the duodenum. These results provide the first evidence that LEAP2 functions as an antagonist of GHS-R in the anuran amphibian X. tropicalis. It has also been suggested that the ghrelin/GHS-R/LEAP2 system may be involved in energy homeostasis in X. tropicalis.
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Affiliation(s)
- Reiko Wada
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Shota Takemi
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Mio Matsumoto
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Mio Iijima
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Takafumi Sakai
- Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan.
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Chicken LEAP2 Level Substantially Changes with Feed Intake and May Be Regulated by CDX4 in Small Intestine. Animals (Basel) 2022; 12:ani12243496. [PMID: 36552416 PMCID: PMC9774203 DOI: 10.3390/ani12243496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Ghrelin O-acyltransferase (GOAT), ghrelin, and GHSR have been reported to play important roles that influence feed intake in mammals. LEAP2, an endogenous antagonist of GHSR, plays an important role in the regulation of feed intake. However, chicken ghrelin has also been reported to have an inhibitory effect on feed intake. The role of the GOAT-Ghrelin-GHSR-LEAP2 axis in chicken-feed intake remains unclear. Therefore, it is necessary to systematically evaluate the changes in the tissue expression levels of these genes under different energy states. In this study, broiler chicks in different energy states were subjected to starvation and feeding, and relevant gene expression levels were measured using quantitative real-time PCR. Different energy states significantly modulated the expression levels of LEAP2 and GHSR but did not significantly affect the expression levels of GOAT and ghrelin. A high expression level of LEAP2 was detected in the liver and the whole small intestine. Compared to the fed group, the fasted chicks showed significantly reduced LEAP2 expression levels in the liver and the small intestine; 2 h after being refed, the LEAP2 expression of the fasted chicks returned to the level of the fed group. Transcription factor prediction and results of a dual luciferase assay indicated that the transcription factor CDX4 binds to the LEAP2 promoter region and positively regulates its expression. High expression levels of GHSR were detected in the hypothalamus and pituitary. Moreover, we detected GHSR highly expressed in the jejunum-this finding has not been previously reported. Thus, GHSR may regulate intestinal motility, and this aspect needs further investigation. In conclusion, this study revealed the function of chicken LEAP2 as a potential feed-intake regulator and identified the potential mechanism governing its intestine-specific expression. Our study lays the foundations for future studies on avian feed-intake regulation.
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Effect of Ghrelin on the Cardiovascular System. BIOLOGY 2022; 11:biology11081190. [PMID: 36009817 PMCID: PMC9405061 DOI: 10.3390/biology11081190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/19/2022]
Abstract
Simple Summary Ghrelin is an octanoylated peptide that was initially isolated from rat and human stomachs in the process of searching for an endogenous ligand to the orphan growth hormone secretagogue receptor (GHS-R), a G-protein-coupled receptor. Exogenous or endogenous ghrelin secreted from the stomach binds to GHS-R on gastric vagal nerve terminals, and the signals are transmitted to the central nervous system via the vagal afferent nerve to facilitate growth hormone (GH) secretion, feeding, sympathetic inhibition, parasympathetic activation, and anabolic effects. Ghrelin also binds directly to the pituitary GHS-R and stimulates GH secretion. Ghrelin has beneficial effects on the cardiovascular system, including cardioprotective effects such as anti-heart failure, anti-arrhythmic, and anti-inflammatory actions, and it enhances vascular activity via GHS-R-dependent stimulation of GH/IGF-1 (insulin-like growth factor-1) and modulation of the autonomic nervous system. The anti-heart failure effects of ghrelin could be useful as a new therapeutic strategy for chronic heart failure. Abstract Ghrelin, an n-octanoyl-modified 28-amino-acid-peptide, was first discovered in the human and rat stomach as an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). Ghrelin-GHS-R1a signaling regulates feeding behavior and energy balance, promotes vascular activity and angiogenesis, improves arrhythmia and heart failure, and also protects against cardiovascular disease by suppressing cardiac remodeling after myocardial infarction. Ghrelin’s cardiovascular protective effects are mediated by the suppression of sympathetic activity; activation of parasympathetic activity; alleviation of vascular endothelial dysfunction; and regulation of inflammation, apoptosis, and autophagy. The physiological functions of ghrelin should be clarified to determine its pharmacological potential as a cardiovascular medication.
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Orellana E, Horvath N, Farokhnia M, Leggio L, Hajnal A. Changes in Plasma Ghrelin Levels Following Surgical and Non-Surgical Weight-Loss in Female Rats Predict Alcohol Use. Brain Res Bull 2022; 188:179-186. [PMID: 35901985 DOI: 10.1016/j.brainresbull.2022.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/20/2022] [Accepted: 07/24/2022] [Indexed: 11/02/2022]
Abstract
The weight-loss surgery Roux-en Y gastric bypass (RYGB) is a relatively effective, long-term treatment option for patients with morbid obesity. However, accumulating clinical evidence suggests that patients receiving RYGB may be at increased risk of developing alcohol use disorder. This observation has been repeatedly supported by preclinical studies showing rodents increase intake of ethanol (EtOH) after RYGB, and has been further confirmed by human studies. A promising alternative to RYGB is sleeve gastrectomy (SG), which has resulted in decreased EtOH consumption in some rodent studies. The exact mechanism underlying the differential alcohol outcomes after RYGB versus SG has yet to be elucidated. However, the gut hormone ghrelin has emerged as a potential candidate from previous preclinical studies specific to RYGB surgeries and due to its action to stimulate food and alcohol intake and cravings. To directly assess changes in plasma ghrelin levels following weigh loss surgeries in the context of alcohol intake, 24 female rats were separated into three surgical groups receiving RYGB, SG, or Sham surgery followed by caloric restriction to produce adiposity matched controls (Sham-AM). Blood was drawn for fasted and fed plasma ghrelin (acyl and des-acyl) assays at multiple time points: while on a normal diet (ND), after 5-week exposure to a high fat diet (HFD), following surgery, and after a series of two-bottle alcohol choice test with increasing concentrations (2%, 4%, 6%, 8%) of EtOH. Consistent with previous observations, RYGB rats drank more EtOH than SG rats across all concentrations. As expected, fasted ghrelin levels were blunted after HFD feeding, compared to normal diet baseline. After RYGB, fasted ghrelin levels returned to higher levels while remained blunted after SG and Sham-AM. Fed acyl ghrelin levels were significantly increased to above "normal" levels after RYGB, but remain low after SG and Sham-AM. Given that post-RYGB acyl ghrelin levels are raised to a fasted state regardless of actual prandial status, we conclude that RYGB may results in a hormonal state reminiscence of a fasted state with the inability of feeding to inhibit ghrelin production, an effect which could potentially contribute to increased EtOH intake following the surgery. In contrast, following SG, ghrelin levels in rats remain consistent with the fed state regardless of prandial status, potentially explaining lower alcohol intake and lower risk of developing AUD.
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Affiliation(s)
- Elise Orellana
- The Pennsylvania State University College of Medicine, Department of Neural and Behavioral Sciences.
| | - Nelli Horvath
- The Pennsylvania State University College of Medicine, Department of Neural and Behavioral Sciences
| | - 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, Baltimore and Bethesda, Maryland, USA
| | - 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, Baltimore and Bethesda, Maryland, USA
| | - Andras Hajnal
- The Pennsylvania State University College of Medicine, Department of Neural and Behavioral Sciences
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Chen D, Li Y, Wu H, Wu Y, Tang N, Chen S, Liu Y, Wang J, Zhang X, Li Z. Ghrelin-Ghrelin receptor (GSHR) pathway via endocannabinoid signal affects the expression of NPY to promote the food intake of Siberian sturgeon (Acipenser baerii). Horm Behav 2022; 143:105199. [PMID: 35597053 DOI: 10.1016/j.yhbeh.2022.105199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/03/2022] [Accepted: 05/10/2022] [Indexed: 11/24/2022]
Abstract
Previous data suggested that activation of endocannabinoid receptor 1 (CB1) was necessary for the orexigenic effect of Ghrelin in rodents, but the information is limited in teleosts. To investigate the feeding regulation pathway of Ghrelin and CB1 in Siberian sturgeon (Acipenser baerii), this study first identified the Ghrelin (345 bp, complete coding sequence) and Ghrelin receptor (GHSR, 500 bp, partial coding sequence) sequences, and then detected their tissue distribution patterns, which showed that Ghrelin is mainly distribution in peripheral tissues, while GSHR is mainly in different brain divisions. Besides, the qPCR before and after feeding showed that the mRNA expressions of Ghrelin and GHSR were inhibited after feeding in telencephalon, diencephalon and mesencephalon. Subsequently, the food intake and appetite factor expressions were measured by i.c.v. co-injection of Ghrelin and GSHR antagonist. The results showed that Ghrelin promoted the food intake of Siberian sturgeon, which was reversed by its receptor antagonist. Besides, i.c.v. injection of Ghrelin decreased telencephalon CART expression while increased NPY expression in the three brain regions. In addition, to further explore the relationship of Ghrelin and CB1 signal regulating feeding, the co-injection of Ghrelin and CB1 antagonists was performed. The results showed that AM6545 (CB1 peripheral restricted antagonist) failed to affect the orexigenic effect of Ghrelin and the expression pattern of NPY mRNA in the telencephalon. While in the diencephalon, the increase of food intake and NPY mRNA expression induced by Ghrelin was completely reversed by Rimonabant (CB1 global antagonist). These results indicate Ghrelin-GSHR pathway promotes the food intake of Siberian sturgeon by inducing the expression of NPY in the diencephalon, and the stimulating effect will be reversed by cannabinoid receptor antagonism. This study provides a foundation for understanding the pathways Ghrelin and CB1 signals in appetite regulation of the teleost.
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Affiliation(s)
- Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China
| | - Yingzi Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China
| | - Hongwei Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China; Chengdu Agricultural College, 392#, Detong Bridge Road, Chengdu, China
| | - Yuanbing Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China
| | - Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China
| | - Shuhuang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China
| | - Youlian Liu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China
| | - Jun Wang
- Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, Neijiang Normal University, 1124#, Dongtong Road, Neijiang, China
| | - Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China.
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211#, Huimin Road, Chengdu, China.
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New Aspects of Corpus Luteum Regulation in Physiological and Pathological Conditions: Involvement of Adipokines and Neuropeptides. Cells 2022; 11:cells11060957. [PMID: 35326408 PMCID: PMC8946127 DOI: 10.3390/cells11060957] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 02/28/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
The corpus luteum is a small gland of great importance because its proper functioning determines not only the appropriate course of the estrous/menstrual cycle and embryo implantation, but also the subsequent maintenance of pregnancy. Among the well-known regulators of luteal tissue functions, increasing attention is focused on the role of neuropeptides and adipose tissue hormones—adipokines. Growing evidence points to the expression of these factors in the corpus luteum of women and different animal species, and their involvement in corpus luteum formation, endocrine function, angiogenesis, cells proliferation, apoptosis, and finally, regression. In the present review, we summarize the current knowledge about the expression and role of adipokines, such as adiponectin, leptin, apelin, vaspin, visfatin, chemerin, and neuropeptides like ghrelin, orexins, kisspeptin, and phoenixin in the physiological regulation of the corpus luteum function, as well as their potential involvement in pathologies affecting the luteal cells that disrupt the estrous cycle.
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Iijima M, Takemi S, Aizawa S, Sakai T, Sakata I. The suppressive effect of REVERBs on ghrelin and GOAT transcription in gastric ghrelin-producing cells. Neuropeptides 2021; 90:102187. [PMID: 34450431 DOI: 10.1016/j.npep.2021.102187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 08/05/2021] [Accepted: 08/19/2021] [Indexed: 11/30/2022]
Abstract
Ghrelin is a multifunctional gut peptide with a unique structure, which is modified by a medium chain fatty acid at the third serine by ghrelin O-acyl transferase (GOAT). It is well known that the major source of plasma ghrelin is the stomach, but the transcriptional regulation of gastric ghrelin and GOAT is incompletely understood. Here, we studied the involvement of the nuclear receptors REV-ERBα and REV-ERBβ on ghrelin and GOAT gene expression in vivo and in vitro. Reverse-transcriptase polymerase chain reaction analysis showed that REV-ERBα and REV-ERBβ mRNAs were expressed in the stomach and a stomach-derived ghrelin cell line (SG-1 cells). In vivo experiments with mice revealed the circadian rhythm of ghrelin, GOAT, and REV-ERBs. The peak expression of ghrelin and GOAT mRNAs occurred at Zeitgeber time (ZT) 4, whereas that of REV-ERBα and REV-ERBβ was observed at ZT8 and ZT12, respectively. Treatment of SG-1 cells with SR9009, a REV-ERB agonist, led to a significant reduction in ghrelin and GOAT mRNA levels. Overexpression of REV-ERBα and REV-ERBβ decreased ghrelin and GOAT mRNA levels in SG-1 cells. In contrast, small-interfering RNA (siRNA)-mediated double-knockdown of REV-ERBα and REV-ERBβ in SG-1 cells led to the upregulation in the expression of ghrelin and GOAT mRNAs. These results suggest that REV-ERBs suppress ghrelin and GOAT mRNA expression.
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Affiliation(s)
- Mio Iijima
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Shota Takemi
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Sayaka Aizawa
- Department of Biology, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kitaku, Okayama 700-8530, Japan
| | - Takafumi Sakai
- Professor emeritus, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan; Area of Life-NanoBio, Division of Strategy Research, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
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12
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Thermoregulatory role of ghrelin in the induction of torpor under a restricted feeding condition. Sci Rep 2021; 11:17954. [PMID: 34518616 PMCID: PMC8438062 DOI: 10.1038/s41598-021-97440-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/24/2021] [Indexed: 12/04/2022] Open
Abstract
Ghrelin, a circulating orexigenic hormone secreted from the stomach, stimulates appetite and food intake by activating the hypothalamic arcuate nucleus. Administration of exogenous ghrelin exerts anabolic effects, causing weight gain, increased adiposity, and decreased metabolism. Body temperature (BT), which is determined by the balance of heat production and heat loss, must be strictly regulated to maintain proper cellular function and metabolism. However, the role of ghrelin in thermoregulation remains unclear. In this study, we found that ghrelin was essential for decreasing BT when mice are placed under calorie restriction. Elevated ghrelin concentrations induced by fasting correlated with significant decreases in BT, a hibernation-like state called torpor. Ghrelin-deficient (Ghrl−/−) animals could not enter torpor. The BT of Ghrl−/− mice also remained high under restricted feeding, but the animals gradually entered precipitous hypothermia, indicating thermoregulatory impairment. These effects of ghrelin on thermoregulation were the result of suppression of sympathetic nervous system activity input to brown adipose tissue; in the absence of ghrelin, it was not possible to suppress uncoupling protein 1 (ucp1) expression and decrease BT in low-energy states. Together, these findings demonstrate that ghrelin is an essential circulating hormone involved in lowering BT.
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13
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Nogueiras R. MECHANISMS IN ENDOCRINOLOGY: The gut-brain axis: regulating energy balance independent of food intake. Eur J Endocrinol 2021; 185:R75-R91. [PMID: 34260412 PMCID: PMC8345901 DOI: 10.1530/eje-21-0277] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022]
Abstract
Obesity is a global pandemic with a large health and economic burden worldwide. Bodyweight is regulated by the ability of the CNS, and especially the hypothalamus, to orchestrate the function of peripheral organs that play a key role in metabolism. Gut hormones play a fundamental role in the regulation of energy balance, as they modulate not only feeding behavior but also energy expenditure and nutrient partitioning. This review examines the recent discoveries about hormones produced in the stomach and gut, which have been reported to regulate food intake and energy expenditure in preclinical models. Some of these hormones act on the hypothalamus to modulate thermogenesis and adiposity in a food intake-independent fashion. Finally, the association of these gut hormones to eating, energy expenditure, and weight loss after bariatric surgery in humans is discussed.
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Affiliation(s)
- Ruben Nogueiras
- Department of Physiology, CIMUS, USC, CIBER Fisiopatología Obesidad y Nutrición (CiberOBN), Instituto Salud Carlos III, Galician Agency of Innovation, Xunta de Galicia, Santiago de Compostela, Spain
- Correspondence should be addressed to R Nogueiras;
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14
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Orellana ER, Piscura MK, Horvath N, Hajnal A. Differential Response in Ethanol Behaviors of Female Rats Given Various Weight Loss Surgeries. Alcohol Alcohol 2021; 56:599-604. [PMID: 34343232 DOI: 10.1093/alcalc/agab054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022] Open
Abstract
AIMS Currently, the only effective treatment for morbid obesity and its comorbidities is weight loss surgery (WLS). Growing evidence suggests that different types of WLS, such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), have differential effects on alcohol consumption in humans and rats. Thus, we aimed to directly compare the effects of these two surgical procedures, for the first time in female rats, and to determine whether presence or absence of the ghrelin-producing stomach tissue has critical influence on postoperative alcohol intake. METHODS We performed two experiments using an identical behavioral protocol, a continuous-access two-bottle choice protocol for various concentrations of ethanol (EtOH). In Experiment 1, 23 high fat diet (HFD) obese, female rats were randomized to three groups: RYGB, SG or sham-operated food-restricted (Sham) controls. In Experiment 2, HFD obese female rats received either sham (n = 11) or a modified RYGB surgery where the remnant stomach was removed (RYGB-X; n = 12). RESULTS SG rats drank significantly less than RYGB for 4, 6 and 8% and significantly less than Sham for 6, 8 and 8% reinstatement. RYGB-X consumed significantly less EtOH than Sham across all concentrations, reaching significance for 6 and 8% reinstatement. CONCLUSION These findings confirm reduced EtOH consumption by female SG rats as opposed to increased intake following RYGB, and provide the first experimental evidence that the remnant stomach in the RYGB procedure is contributory. Future studies in rats and humans are warranted to confirm that ghrelin plays a critical role in susceptibility to AUD development following WLS.
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Affiliation(s)
- Elise R Orellana
- Georgetown University, School of Medicine, Department of Biochemistry and Molecular & Cellular Biology, 3900 Reservoir Road NW, Washington, DC, 20009
| | - Mary K Piscura
- The Pennsylvania State University, College of Medicine, Department of Neural and Behavioral Sciences, 700 HMC Crescent road, Hershey, PA 17033
| | - Nelli Horvath
- The Pennsylvania State University, College of Medicine, Department of Neural and Behavioral Sciences, 700 HMC Crescent road, Hershey, PA 17033
| | - Andras Hajnal
- The Pennsylvania State University, College of Medicine, Department of Neural and Behavioral Sciences, 700 HMC Crescent road, Hershey, PA 17033
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15
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Ramadhin J, Silva-Moraes V, Nagy T, Norberg T, Harn D. A Comparison of Two Structurally Related Human Milk Oligosaccharide Conjugates in a Model of Diet-Induced Obesity. Front Immunol 2021; 12:668217. [PMID: 34093565 PMCID: PMC8173488 DOI: 10.3389/fimmu.2021.668217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/30/2021] [Indexed: 12/29/2022] Open
Abstract
Obesity is the largest risk factor for the development of chronic diseases in industrialized countries. Excessive fat accumulation triggers a state of chronic low-grade inflammation to the detriment of numerous organs. To address this problem, our lab has been examining the anti-inflammatory mechanisms of two human milk oligosaccharides (HMOs), lacto-N-fucopentaose III (LNFPIII) and lacto-N-neotetraose (LNnT). LNFPIII and LNnT are HMOs that differ in structure via presence/absence of an α1,3-linked fucose. We utilize LNFPIII and LNnT in conjugate form, where 10-12 molecules of LNFPIII or LNnT are conjugated to a 40 kDa dextran carrier (P3DEX/NTDEX). Previous studies from our lab have shown that LNFPIII conjugates are anti-inflammatory, act on multiple cell types, and are therapeutic in a wide range of murine inflammatory disease models. The α1,3-linked fucose residue on LNFPIII makes it difficult and more expensive to synthesize. Therefore, we asked if LNnT conjugates induced similar therapeutic effects to LNFPIII. Herein, we compare the therapeutic effects of P3DEX and NTDEX in a model of diet-induced obesity (DIO). Male C57BL/6 mice were placed on a high-fat diet for six weeks and then injected twice per week for eight weeks with 25µg of 40 kDa dextran (DEX; vehicle control), P3DEX, or NTDEX. We found that treatment with P3DEX, but not NTDEX, led to reductions in body weight, adipose tissue (AT) weights, and fasting blood glucose levels. Mice treated with P3DEX also demonstrated improvements in glucose homeostasis and insulin tolerance. Treatment with P3DEX or NTDEX also induced different profiles of serum chemokines, cytokines, adipokines, and incretin hormones, with P3DEX notably reducing circulating levels of leptin and resistin. P3DEX also reduced WAT inflammation and hepatic lipid accumulation, whereas NTDEX seemed to worsen these parameters. These results suggest that the small structural difference between P3DEX and NTDEX has significant effects on the conjugates' therapeutic abilities. Future work will focus on identifying the receptors for these conjugates and delineating the mechanisms by which P3DEX and NTDEX exert their effects.
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Affiliation(s)
- Jessica Ramadhin
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Vanessa Silva-Moraes
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Tamas Nagy
- Department of Pathology, University of Georgia, Athens, GA, United States
| | - Thomas Norberg
- Department of Chemistry-BMC, Uppsala University, Uppsala, Sweden
| | - Donald Harn
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States
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16
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Schwartz A, Bellissimo N. Nicotine and energy balance: A review examining the effect of nicotine on hormonal appetite regulation and energy expenditure. Appetite 2021; 164:105260. [PMID: 33848592 DOI: 10.1016/j.appet.2021.105260] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 12/15/2022]
Abstract
Nicotine has been shown to decrease appetite, food intake (FI) and body weight, but the mechanisms are unclear. The purpose of this review was to examine research on the effects of nicotine on energy balance by exploring physiological mechanisms and hormone regulation related to FI, subjective appetite and energy expenditure (EE). We searched PubMed and MEDLINE, and included articles investigating the effects of nicotine on central appetite regulation, FI, leptin, peptide-YY (PYY), ghrelin, glucagon-like peptide-1 (GLP-1), adiponectin, cholecystokinin (CCK), orexin, and EE. A total of 65 studies were included in the qualitative synthesis and review. Our findings suggest that the decrease in appetite and FI may be attributed to nicotinic alterations of neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) but the effect of nicotine on FI remains unclear. Furthermore, nicotine increases resting EE (REE) and physical activity EE (PAEE) in both smokers and non-smokers; and these increases may be a result of the catecholaminergic effect of nicotine. Decreases in body weight and appetite experienced by nicotine users results from increased EE and changes in the central hypothalamic regulation of appetite. There is not enough evidence to implicate a relationship between peripheral hormones and changes in appetite or FI after nicotine use. Although nicotine increases REE and PAEE, the effect of nicotine on other components of EE warrants further research. We conclude that further research evaluating the effect of nicotine on appetite hormones, FI and EE in humans is warranted.
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Affiliation(s)
| | - Nick Bellissimo
- School of Nutrition, Ryerson University, Toronto, Ontario, Canada.
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17
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Cawthon CR, de La Serre CB. The critical role of CCK in the regulation of food intake and diet-induced obesity. Peptides 2021; 138:170492. [PMID: 33422646 DOI: 10.1016/j.peptides.2020.170492] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 12/16/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022]
Abstract
In 1973, Gibbs, Young, and Smith showed that exogenous cholecystokinin (CCK) administration reduces food intake in rats. This initial report has led to thousands of studies investigating the physiological role of CCK in regulating feeding behavior. CCK is released from enteroendocrine I cells present along the gastrointestinal (GI) tract. CCK binding to its receptor CCK1R leads to vagal afferent activation providing post-ingestive feedback to the hindbrain. Vagal afferent neurons' (VAN) sensitivity to CCK is modulated by energy status while CCK signaling regulates gene expression of other feeding related signals and receptors expressed by VAN. In addition to its satiation effects, CCK acts all along the GI tract to optimize digestion and nutrient absorption. Diet-induced obesity (DIO) is characterized by reduced sensitivity to CCK and every part of the CCK system is negatively affected by chronic intake of energy-dense foods. EEC have recently been shown to adapt to diet, CCK1R is affected by dietary fats consumption, and the VAN phenotypic flexibility is lost in DIO. Altered endocannabinoid tone, changes in gut microbiota composition, and chronic inflammation are currently being explored as potential mechanisms for diet driven loss in CCK signaling. This review discusses our current understanding of how CCK controls food intake in conditions of leanness and how control is lost in chronic energy excess and obesity, potentially perpetuating excessive intake.
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Affiliation(s)
- Carolina R Cawthon
- Department of Foods and Nutrition, University of Georgia, Athens, GA, USA
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18
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Kimura R, Kondo D, Takemi S, Fujishiro M, Tsukahara S, Sakai T, Sakata I. The role of central corticotrophin-releasing factor receptor signalling in plasma glucose maintenance through ghrelin secretion in calorie-restricted mice. J Neuroendocrinol 2021; 33:e12961. [PMID: 33675127 DOI: 10.1111/jne.12961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 11/27/2022]
Abstract
Under severe calorie restriction (CR), the ghrelin-growth hormone axis in mice is involved in the maintenance of plasma glucose levels. Ghrelin, a stomach-derived acylated peptide, is up-regulated by the sympathetic nerve in the negative energy status. Central corticotrophin-releasing factor receptor (CRF-R) signalling stimulates the sympathetic tone. The present study aimed to examine the effect of central CRF-R signalling on the maintenance of plasma glucose concentrations in severe calorie-restricted mice with the involvement of ghrelin. Intracerebroventricular injections of urocorin-1 and urocorin-2, which are natural ligands for CRF-R1 and CRF-R2, elevated plasma ghrelin concentrations and ghrelin elevation with an i.c.v. injection of urocorin-1 was cancelled by atenolol (β1 adrenergic receptor antagonist) administration. We then established a mice model of 60% CR and found that the administration of [d-Lys3]-GHRP-6 (a ghrelin receptor antagonist) in mice under 60% CR reduced the plasma glucose concentration more compared to the vehicle mice. Similarly, the atenolol injection in mice under 60% CR significantly reduced the plasma glucose concentration, which was rescued by the co-administration of ghrelin. An i.c.v. injection of the alpha helical CRH, a non-selective corticotrophin-releasing factor receptor antagonist, in mice under 60% CR significantly reduced the plasma glucose concentration, although the co-administration of α-helical CRH with ghrelin maintained plasma glucose levels. These results suggest that central CRF-R signalling is involved in the maintenance of plasma glucose levels in mice under severe CR via the sympathetic-ghrelin pathway.
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Affiliation(s)
- Risa Kimura
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Daisuke Kondo
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Shota Takemi
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Miyuki Fujishiro
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
- Nikkol Group Cosmos Technical Center Co., Ltd, Tokyo, Japan
| | - Shinji Tsukahara
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
- Division of Strategy Research, Graduate School of Science and Engineering, Area of Life-NanoBio, Saitama University, Saitama, Japan
| | | | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
- Division of Strategy Research, Graduate School of Science and Engineering, Area of Life-NanoBio, Saitama University, Saitama, Japan
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19
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Theilade S, Christensen MB, Vilsbøll T, Knop FK. An overview of obesity mechanisms in humans: Endocrine regulation of food intake, eating behaviour and common determinants of body weight. Diabetes Obes Metab 2021; 23 Suppl 1:17-35. [PMID: 33621414 DOI: 10.1111/dom.14270] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/21/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022]
Abstract
Obesity is one of the biggest health challenges of the 21st century, already affecting close to 700 million people worldwide, debilitating and shortening lives and costing billions of pounds in healthcare costs and loss of workability. Body weight homeostasis relies on complex biological mechanisms and the development of obesity occurs on a background of genetic susceptibility and an environment promoting increased caloric intake and reduced physical activity. The pathophysiology of common obesity links neuro-endocrine and metabolic disturbances with behavioural changes, genetics, epigenetics and cultural habits. Also, specific causes of obesity exist, including monogenetic diseases and iatrogenic causes. In this review, we provide an overview of obesity mechanisms in humans with a focus on energy homeostasis, endocrine regulation of food intake and eating behavior, as well as the most common specific causes of obesity.
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Affiliation(s)
- Simone Theilade
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Medicine, Herlev-Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel B Christensen
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Pharmacology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
- Copenhagen Center for Translational Research, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Tina Vilsbøll
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Filip K Knop
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Medicine, Herlev-Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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20
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Landry T, Shookster D, Chaves A, Free K, Nguyen T, Huang H. Energy Status Differentially Modifies Feeding Behavior and POMC ARC Neuron Activity After Acute Treadmill Exercise in Untrained Mice. Front Endocrinol (Lausanne) 2021; 12:705267. [PMID: 34220725 PMCID: PMC8253227 DOI: 10.3389/fendo.2021.705267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
Emerging evidence identifies a potent role for aerobic exercise to modulate activity of neurons involved in regulating appetite; however, these studies produce conflicting results. These discrepancies may be, in part, due to methodological differences, including differences in exercise intensity and pre-exercise energy status. Consequently, the current study utilized a translational, well-controlled, within-subject, treadmill exercise protocol to investigate the differential effects of energy status and exercise intensity on post-exercise feeding behavior and appetite-controlling neurons in the hypothalamus. Mature, untrained male mice were exposed to acute sedentary, low (10m/min), moderate (14m/min), and high (18m/min) intensity treadmill exercise in a randomized crossover design. Fed and 10-hour-fasted mice were used, and food intake was monitored 48h. post-exercise. Immunohistochemical detection of cFOS was performed 1-hour post-exercise to determine changes in hypothalamic NPY/AgRP, POMC, tyrosine hydroxylase, and SIM1-expressing neuron activity concurrent with changes in food intake. Additionally, stains for pSTAT3tyr705 and pERKthr202/tyr204 were performed to detect exercise-mediated changes in intracellular signaling. Results demonstrated that fasted high intensity exercise suppressed food intake compared to sedentary trials, which was concurrent with increased anorexigenic POMC neuron activity. Conversely, fed mice experienced augmented post-exercise food intake, with no effects on POMC neuron activity. Regardless of pre-exercise energy status, tyrosine hydroxylase and SIM1 neuron activity in the paraventricular nucleus was elevated, as well as NPY/AgRP neuron activity in the arcuate nucleus. Notably, these neuronal changes were independent from changes in pSTAT3tyr705 and pERKthr202/tyr204 signaling. Overall, these results suggest fasted high intensity exercise may be beneficial for suppressing food intake, possibly due to hypothalamic POMC neuron excitation. Furthermore, this study identifies a novel role for pre-exercise energy status to differentially modify post-exercise feeding behavior and hypothalamic neuron activity, which may explain the inconsistent results from studies investigating exercise as a weight loss intervention.
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Affiliation(s)
- Taylor Landry
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States
- Department of Kinesiology, East Carolina University, Greenville, NC, United States
- Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, United States
| | - Daniel Shookster
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States
- Department of Kinesiology, East Carolina University, Greenville, NC, United States
- Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, United States
| | - Alec Chaves
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States
- Department of Kinesiology, East Carolina University, Greenville, NC, United States
- Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, United States
| | - Katrina Free
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States
- Department of Kinesiology, East Carolina University, Greenville, NC, United States
- Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, United States
| | - Tony Nguyen
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States
- Department of Kinesiology, East Carolina University, Greenville, NC, United States
- Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, United States
| | - Hu Huang
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States
- Department of Kinesiology, East Carolina University, Greenville, NC, United States
- Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, United States
- Department of Physiology, East Carolina University, Greenville, NC, United States
- *Correspondence: Hu Huang,
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21
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Spann RA, Welch BA, Grayson BE. Ghrelin signalling is dysregulated in male but not female offspring in a rat model of maternal vertical sleeve gastrectomy. J Neuroendocrinol 2021; 33:e12913. [PMID: 33169872 PMCID: PMC7831688 DOI: 10.1111/jne.12913] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 10/12/2020] [Accepted: 10/12/2020] [Indexed: 12/18/2022]
Abstract
Bariatric surgery is the most effective and durable means of treating obesity and its comorbidities. Women make up 80% of those receiving weight loss surgery and they experience improvements in fertility. Unfortunately, bariatric surgery in the context of pregnancy is associated with complications, including growth restriction and small-for-gestational age offspring (SGA). SGA offspring have a greater risk for obesity in adulthood, although the mechanism for this SGA-induced obesity is unknown. In a rat model of vertical sleeve gastrectomy (VSG), we previously identified reductions during pregnancy in ghrelin, a stomach-derived hormone that increases appetite and induces growth hormone secretion. Here, we hypothesise that VSG offspring will have altered ghrelin signalling compared to offspring of Sham dams as a result of reduced in utero ghrelin. At postnatal day (PND)21, male and female offspring of dams that have previously received VSG have an increase in mRNA expression for the ghrelin receptor in the hypothalamus compared to Sham offspring, and the expression of GOAT is lower in females compared to males. Liver expression of endogenous ghrelin antagonist, LEAP2, is elevated at PND60 in VSG offspring. Expression of other genes in the growth hormone system (growth hormone-releasing hormone and growth hormone) were not altered. Plasma levels of total ghrelin at PND21 are also not different between VSG and Sham pups. In adult pups, 1-hour chow intake of male but not female VSG offspring given is less than Sham offspring when given 50 µg kg-1 of exogenous ghrelin by i.p. injection. These results indicate that maternal VSG surgery has an impact on ghrelin signalling in offspring and that, as adults, male VSG offspring may be functionally less responsive to ghrelin than controls.
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Affiliation(s)
- Redin A. Spann
- Department of Neurobiology and Anatomical Sciences University of Mississippi Medical Center, Jackson, MS 39216
| | - Bradley A. Welch
- Department of Neurobiology and Anatomical Sciences University of Mississippi Medical Center, Jackson, MS 39216
| | - Bernadette E. Grayson
- Department of Neurobiology and Anatomical Sciences University of Mississippi Medical Center, Jackson, MS 39216
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22
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Gulubova MV, Tolekova AN, Ivanova K, Hamza S, Hadzhi M, Chonov D, Ananiev J. Fructose-induced metabolic disturbances in rats and its impact on stomach endocrine cell number and smooth muscle contractility. Arch Physiol Biochem 2020; 126:440-448. [PMID: 30633582 DOI: 10.1080/13813455.2018.1555601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Context: Gastric ghrelin-positive endocrine cells (GHR + EC) were most dense in the oxyntic mucosa.Objective: We evaluated ECs and contractile activity in rat stomach with metabolic disorders.Materials and methods: Male Wistar rats were divided into two groups: Control (n = 9) received tap water and Fructose (n = 9) drank 15% fructose solution for 12 weeks. Streptozotocin was applied in a dose of 20 mg/kg b.w. two weeks after the beginning of the experiment on Fructose group. Smooth-muscle strips from the stomach were influenced by Angiotensin II for analysis of parameters of contractions. Stomach samples were elaborated with immunohistochemistry for ghrelin, somatostatin, gastrin antibodies and with double immunofluorescence.Results: In treated animals, GHR + EC were significantly increased in the corpus where somatostatin-positive cells were decreased. Contractile activity was decreased.Conclusions: The increase number of GHR + EC was discussed in the context of Somatostatin and Gastrin-positive ECs variations and correlated with the decrease of smooth muscle contraction.
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Affiliation(s)
- Maya V Gulubova
- Department of General and Clinical Pathology, Trakia University, Stara Zagora, Bulgaria
| | - Anna N Tolekova
- Department of Physiology, Pathophysiology and Pharmacology, Trakia University, Stara Zagora, Bulgaria
| | - Koni Ivanova
- Department of General and Clinical Pathology, Trakia University, Stara Zagora, Bulgaria
| | - Sevinch Hamza
- Department of Anatomy, Trakia University, Stara Zagora, Bulgaria
| | - Mehmed Hadzhi
- Department of General and Clinical Pathology, Trakia University, Stara Zagora, Bulgaria
| | - Dimitar Chonov
- Department of General and Clinical Pathology, Trakia University, Stara Zagora, Bulgaria
| | - Julian Ananiev
- Department of General and Clinical Pathology, Trakia University, Stara Zagora, Bulgaria
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23
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Cozzo AJ, Coleman MF, Pearce JB, Pfeil AJ, Etigunta SK, Hursting SD. Dietary Energy Modulation and Autophagy: Exploiting Metabolic Vulnerabilities to Starve Cancer. Front Cell Dev Biol 2020; 8:590192. [PMID: 33224954 PMCID: PMC7674637 DOI: 10.3389/fcell.2020.590192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/14/2020] [Indexed: 12/11/2022] Open
Abstract
Cancer cells experience unique and dynamic shifts in their metabolic function in order to survive, proliferate, and evade growth inhibition in the resource-scarce tumor microenvironment. Therefore, identification of pharmacological agents with potential to reprogram cancer cell metabolism may improve clinical outcomes in cancer therapy. Cancer cells also often exhibit an increased dependence on the process known as autophagy, both for baseline survival and as a response to stressors such as chemotherapy or a decline in nutrient availability. There is evidence to suggest that this increased dependence on autophagy in cancer cells may be exploitable clinically by combining autophagy modulators with existing chemotherapies. In light of the increased metabolic rate in cancer cells, interest is growing in approaches aimed at "starving" cancer through dietary and pharmacologic interventions that reduce availability of nutrients and pro-growth hormonal signals known to promote cancer progression. Several dietary approaches, including chronic calorie restriction and multiple forms of fasting, have been investigated for their potential anti-cancer benefits, yielding promising results in animal models. Induction of autophagy in response to dietary energy restriction may underlie some of the observed benefit. However, while interventions based on dietary energy restriction have demonstrated safety in clinical trials, uncertainty remains regarding translation to humans as well as feasibility of achieving compliance due to the potential discomfort and weight loss that accompanies dietary restriction. Further induction of autophagy through dietary or pharmacologic metabolic reprogramming interventions may enhance the efficacy of autophagy inhibition in the context of adjuvant or neo-adjuvant chemotherapy. Nonetheless, it remains unclear whether therapeutic agents aimed at autophagy induction, autophagy inhibition, or both are a viable therapeutic strategy for improving cancer outcomes. This review discusses the literature available for the therapeutic potential of these approaches.
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Affiliation(s)
- Alyssa J Cozzo
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Duke University School of Medicine, Durham, NC, United States
| | - Michael F Coleman
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jane B Pearce
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Alexander J Pfeil
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Suhas K Etigunta
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Stephen D Hursting
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Nutrition Research Institute, The University of North Carolina at Chapel Hill, Kannapolis, NC, United States
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24
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Gupta S, Mitra A. Heal the heart through gut (hormone) ghrelin: a potential player to combat heart failure. Heart Fail Rev 2020; 26:417-435. [PMID: 33025414 DOI: 10.1007/s10741-020-10032-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 12/17/2022]
Abstract
Ghrelin, a small peptide hormone (28 aa), secreted mainly by X/A-like cells of gastric mucosa, is also locally produced in cardiomyocytes. Being an orexigenic factor (appetite stimulant), it promotes release of growth hormone (GH) and exerts diverse physiological functions, viz. regulation of energy balance, glucose, and/or fat metabolism for body weight maintenance. Interestingly, administration of exogenous ghrelin significantly improves cardiac functions in CVD patients as well as experimental animal models of heart failure. Ghrelin ameliorates pathophysiological condition of the heart in myocardial infarction, cardiac hypertrophy, fibrosis, cachexia, and ischemia reperfusion injury. This peptide also exerts significant impact at the level of vasculature leading to lowering high blood pressure and reversal of endothelial dysfunction and atherosclerosis. However, the molecular mechanism of actions elucidating the healing effects of ghrelin on the cardiovascular system is still a matter of conjecture. Some experimental data indicate its beneficial effects via complex cellular cross talks between autonomic nervous system and cardiovascular cells, some other suggest more direct receptor-mediated molecular actions via autophagy or ionotropic regulation and interfering with apoptotic and inflammatory pathways of cardiomyocytes and vascular endothelial cells. Here, in this review, we summarise available recent data to encourage more research to find the missing links of unknown ghrelin receptor-mediated pathways as we see ghrelin as a future novel therapy in cardiovascular protection.
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Affiliation(s)
- Shreyasi Gupta
- Department of Zoology, Triveni Devi Bhalotia College, Raniganj, Paschim Bardhaman, 713347, India
| | - Arkadeep Mitra
- Department of Zoology, City College , 102/1, Raja Rammohan Sarani, Kolkata, 700009, India.
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25
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Mani BK, Puzziferri N, He Z, Rodriguez JA, Osborne-Lawrence S, Metzger NP, Chhina N, Gaylinn B, Thorner MO, Thomas EL, Bell JD, Williams KW, Goldstone AP, Zigman JM. LEAP2 changes with body mass and food intake in humans and mice. J Clin Invest 2020; 129:3909-3923. [PMID: 31424424 DOI: 10.1172/jci125332] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 06/11/2019] [Indexed: 12/11/2022] Open
Abstract
Acyl-ghrelin administration increases food intake, body weight, and blood glucose. In contrast, mice lacking ghrelin or ghrelin receptors (GHSRs) exhibit life-threatening hypoglycemia during starvation-like conditions, but do not consistently exhibit overt metabolic phenotypes when given ad libitum food access. These results, and findings of ghrelin resistance in obese states, imply nutritional state dependence of ghrelin's metabolic actions. Here, we hypothesized that liver-enriched antimicrobial peptide-2 (LEAP2), a recently characterized endogenous GHSR antagonist, blunts ghrelin action during obese states and postprandially. To test this hypothesis, we determined changes in plasma LEAP2 and acyl-ghrelin due to fasting, eating, obesity, Roux-en-Y gastric bypass (RYGB), vertical sleeve gastrectomy (VSG), oral glucose administration, and type 1 diabetes mellitus (T1DM) using humans and/or mice. Our results suggest that plasma LEAP2 is regulated by metabolic status: its levels increased with body mass and blood glucose and decreased with fasting, RYGB, and in postprandial states following VSG. These changes were mostly opposite of those of acyl-ghrelin. Furthermore, using electrophysiology, we showed that LEAP2 both hyperpolarizes and prevents acyl-ghrelin from activating arcuate NPY neurons. We predict that the plasma LEAP2/acyl-ghrelin molar ratio may be a key determinant modulating acyl-ghrelin activity in response to body mass, feeding status, and blood glucose.
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Affiliation(s)
- Bharath K Mani
- Division of Hypothalamic Research.,Division of Endocrinology & Metabolism, Department of Internal Medicine.,Department of Psychiatry, and
| | - Nancy Puzziferri
- Department of Surgery, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Surgery, Veterans Administration North Texas Heath Care System, Dallas, Texas, USA
| | | | - Juan A Rodriguez
- Division of Hypothalamic Research.,Division of Endocrinology & Metabolism, Department of Internal Medicine.,Department of Psychiatry, and
| | - Sherri Osborne-Lawrence
- Division of Hypothalamic Research.,Division of Endocrinology & Metabolism, Department of Internal Medicine.,Department of Psychiatry, and
| | - Nathan P Metzger
- Division of Hypothalamic Research.,Division of Endocrinology & Metabolism, Department of Internal Medicine.,Department of Psychiatry, and
| | - Navpreet Chhina
- PsychoNeuroEndocrinology Research Group, Neuropsychopharmacology Unit, Centre for Psychiatry, and.,Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Bruce Gaylinn
- Department of Endocrinology, University of Virginia, Charlottesville, Virginia, USA
| | - Michael O Thorner
- Department of Endocrinology, University of Virginia, Charlottesville, Virginia, USA
| | - E Louise Thomas
- Research Centre for Optimal Health, University of Westminster, London, United Kingdom
| | - Jimmy D Bell
- Research Centre for Optimal Health, University of Westminster, London, United Kingdom
| | | | - Anthony P Goldstone
- PsychoNeuroEndocrinology Research Group, Neuropsychopharmacology Unit, Centre for Psychiatry, and.,Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Jeffrey M Zigman
- Division of Hypothalamic Research.,Division of Endocrinology & Metabolism, Department of Internal Medicine.,Department of Psychiatry, and
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26
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Maniscalco JW, Edwards CM, Rinaman L. Ghrelin signaling contributes to fasting-induced attenuation of hindbrain neural activation and hypophagic responses to systemic cholecystokinin in rats. Am J Physiol Regul Integr Comp Physiol 2020; 318:R1014-R1023. [PMID: 32292065 DOI: 10.1152/ajpregu.00346.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In rats, overnight fasting reduces the ability of systemic cholecystokinin-8 (CCK) to suppress food intake and to activate cFos in the caudal nucleus of the solitary tract (cNTS), specifically within glucagon-like peptide-1 (GLP-1) and noradrenergic (NA) neurons of the A2 cell group. Systemic CCK increases vagal sensory signaling to the cNTS, an effect that is amplified by leptin and reduced by ghrelin. Since fasting reduces plasma leptin and increases plasma ghrelin levels, we hypothesized that peripheral leptin administration and/or antagonism of ghrelin receptors in fasted rats would rescue the ability of CCK to activate GLP-1 neurons and a caudal subset of A2 neurons that coexpress prolactin-releasing peptide (PrRP). To test this, cFos expression was examined in ad libitum-fed and overnight food-deprived (DEP) rats after intraperitoneal CCK, after coadministration of leptin and CCK, or after intraperitoneal injection of a ghrelin receptor antagonist (GRA) before CCK. In fed rats, CCK activated cFos in ~60% of GLP-1 and PrRP neurons. Few or no GLP-1 or PrRP neurons expressed cFos in DEP rats treated with CCK alone, CCK combined with leptin, or GRA alone. However, GRA pretreatment increased the ability of CCK to activate GLP-1 and PrRP neurons and also enhanced the hypophagic effect of CCK in DEP rats. Considered together, these new findings suggest that reduced behavioral sensitivity to CCK in fasted rats is at least partially due to ghrelin-mediated suppression of hindbrain GLP-1 and PrRP neural responsiveness to CCK.
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Affiliation(s)
- James W Maniscalco
- Department of Psychology and Neuroscience, Regis University, Denver, Colorado
| | - Caitlyn M Edwards
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| | - Linda Rinaman
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
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27
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A role for leptin and ghrelin in the augmentation of heroin seeking induced by chronic food restriction. Psychopharmacology (Berl) 2020; 237:787-800. [PMID: 31811350 DOI: 10.1007/s00213-019-05415-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022]
Abstract
RATIONAL Caloric restriction increases the risk of relapse in abstinent drug users. Hormones involved in the regulation of energy balance and food intake, such as leptin and ghrelin, are implicated in drug-related behaviors. OBJECTIVES We investigated the role of leptin and ghrelin in the augmentation of heroin seeking induced by chronic food restriction. METHODS Rats self-administered heroin (0.1 mg/kg/infusion) for 10 days followed by 14 days of drug withdrawal. During withdrawal, rats were food restricted to 90% of their original body weight or were given free access to food. In experiment 1, we measured the plasma concentrations of leptin and ghrelin following heroin self-administration and withdrawal. In experiment 2, leptin was administered centrally (2.0 or 4.0 μg; i.c.v.) prior to a heroin-seeking test under extinction conditions. High density of both leptin and ghrelin receptors was previously identified in the ventral tegmental area (VTA), suggesting a direct effect on reward and motivation. Hence, we administered leptin (experiment 3; 0.125 or 0.250 μg/side), or ghrelin receptor antagonist JMV 2959 (experiment 4; 2.0 or 10.0 μg/side) directly into the VTA prior to the heroin-seeking test. RESULTS Chronic food restriction significantly decreased plasma levels of leptin and elevated plasma levels of ghrelin. Central administration of leptin had no statistically significant effect on heroin seeking. Intra-VTA administration of either leptin or JMV 2959 dose-dependently and selectively decreased heroin seeking in the food-restricted rats. CONCLUSIONS Leptin and ghrelin transmission in the VTA can modulate the augmentation of heroin seeking induced by chronic food restriction.
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28
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Hay RE, Edwards A, Klein M, Hyland L, MacDonald D, Karatsoreos I, Hill MN, Abizaid A. Ghrelin Receptor Signaling Is Not Required for Glucocorticoid-Induced Obesity in Male Mice. Endocrinology 2020; 161:5636885. [PMID: 31748785 PMCID: PMC7445420 DOI: 10.1210/endocr/bqz023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/19/2019] [Indexed: 12/11/2022]
Abstract
Chronically elevated levels of glucocorticoids increase food intake, weight gain, and adiposity. Similarly, ghrelin, a gut-secreted hormone, is also associated with weight gain, adiposity, and increased feeding. Here we sought to determine if corticosterone-induced metabolic and behavioral changes require functional ghrelin receptors (GHSR). To do this, we treated male C57BL mice with chronic corticosterone (CORT) mixed in their drinking water for 28 days. Half of these mice received the GHSR antagonist JMV2959 via osmotic minipumps while treated with CORT. In a second experiment, we gave the same CORT protocol to mice with a targeted mutation to the GHSR or their wild-type littermates. As expected, CORT treatment increased food intake, weight gain, and adiposity, but contrary to expectations, mice treated with a GHSR receptor antagonist or GHSR knockout (KO) mice did not show attenuated food intake, weight gain, or adiposity in response to CORT. Similarly, the effects of CORT on the liver were the same or more pronounced in GHSR antagonist-treated and GHSR KO mice. Treatment with JMV2959 did attenuate the effects of chronic CORT on glycemic regulation as determined by the glucose tolerance test. Finally, disruption of GHSR signaling resulted in behavioral responses associated with social withdrawal, potentially due to neuroprotective effects of GHSR activation. In all, we propose that blocking GHSR signaling helps to moderate glucose concentrations when CORT levels are high, but blocking GHSR signaling does not prevent increased food intake, weight gain, or increased adiposity produced by chronic CORT.
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Affiliation(s)
- Rebecca E Hay
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Alex Edwards
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Marianne Klein
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Lindsay Hyland
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - David MacDonald
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Ilia Karatsoreos
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, US
| | - Matthew N Hill
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
- Correspondence: Alfonso Abizaid, Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S5B6, Canada. E-mail:
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29
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Sato T, Oishi K, Ida T, Kojima M. Suppressive effect of ghrelin on nicotine-induced clock gene expression in the mouse pancreas. Endocr J 2020; 67:73-80. [PMID: 31611477 DOI: 10.1507/endocrj.ej19-0169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Those who smoke nicotine-based cigarettes have elevated plasma levels of ghrelin, a hormone secreted from the stomach. Ghrelin has various physiological functions and has recently been shown to be involved in regulating biological rhythms. Therefore, in this study, in order to clarify the significance of the plasma ghrelin increase in smokers, we sought to clarify how nicotine and ghrelin affect the expression dynamics of clock genes using a mouse model. A single dose of nicotine administered intraperitoneally increased plasma ghrelin concentrations transiently, whereas continuous administration of nicotine with an osmotic minipump did not induce any change in the plasma ghrelin concentration. Single administration of nicotine resulted in a transient increase in ghrelin gene expression in the pancreas but not in the stomach, which is the major producer of ghrelin. In addition, in the pancreas, the expression of clock genes was also increased temporarily. Therefore, in order to clarify the interaction between nicotine-induced ghrelin gene expression and clock gene expression in the pancreas, nicotine was administered to ghrelin gene-deficient mice. Administration of nicotine to ghrelin-gene deficient mice increased clock gene expression in the pancreas. However, upon nicotine administration to mice pretreated with octanoate to upregulate ghrelin activity, expression levels of nicotine-inducible clock genes in the pancreas were virtually the same as those in mice not administered nicotine. Thus, our findings indicate that pancreatic ghrelin may suppress nicotine-induced clock gene expression in the pancreas.
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Affiliation(s)
- Takahiro Sato
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Kanae Oishi
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 830-0011, Japan
| | - Takanori Ida
- Division for Searching and Identification of Bioactive Peptides, Department of Bioactive Peptides, Frontier Science Research Center, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan
| | - Masayasu Kojima
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 830-0011, Japan
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30
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Leptin, Ghrelin, and Leptin/Ghrelin Ratio in Critically Ill Patients. Nutrients 2019; 12:nu12010036. [PMID: 31877773 PMCID: PMC7020071 DOI: 10.3390/nu12010036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/09/2019] [Accepted: 12/13/2019] [Indexed: 12/22/2022] Open
Abstract
The objective of this study was to evaluate leptin, ghrelin, and leptin/ghrelin ratio in critically ill patients and association of leptin/ghrelin ratio with outcomes. This is a sub-study of the PermiT trial (ISRCTN68144998). A subset of 72 patients who were expected to stay >14 days in the Intensive care unit were enrolled. Blood samples were collected on days 1, 3, 5, 7, and 14. Samples were analyzed for leptin and active ghrelin in addition to other hormones. Baseline leptin/ghrelin ratio was calculated, and patients were stratified into low and high leptin/ghrelin ratio based on the median value of 236. There was a considerable variation in baseline leptin level: Median 5.22 ng/mL (Q1, Q3: 1.26, 17.60). Ghrelin level was generally low: 10.61 pg/mL (Q1, Q3: 8.62, 25.36). Patients with high leptin/ghrelin ratio compared to patients with low leptin/ghrelin ratio were older, had higher body mass index and more likely to be diabetic. There were no differences in leptin/ghrelin ratio between patients who received permissive underfeeding and standard feeding. Multivariable logistic regression analysis showed that age and body mass index were significant independent predictors of high leptin–ghrelin ratio. Leptin–ghrelin ratio was not associated with 90-day mortality or other outcomes. Age and body mass index are predictors of high leptin/ghrelin ratio. Leptin/ghrelin ratio is not affected by permissive underfeeding and is not associated with mortality.
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31
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Huang L, Huang Z, Chen C. Rhythmic growth hormone secretion in physiological and pathological conditions: Lessons from rodent studies. Mol Cell Endocrinol 2019; 498:110575. [PMID: 31499134 DOI: 10.1016/j.mce.2019.110575] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 02/01/2023]
Abstract
Evolutionally conserved in all mammalians, the release of GH occurs in a rhythmic pattern, characterized by several dominant surges (pulsatile GH) with tonic low inter-pulse levels (tonic GH). Such pulsatile secretion pattern is essential for many physiological actions of GH on different tissues with defined gender dimorphism. Rhythmic release of pulsatile GH is tightly controlled by hypothalamic neurons as well as peripheral metabolic factors. Changes of GH pattern occur within a range of sophisticated physiological and pathological settings and significantly contribute to growth, ageing, survival and disease predispositions. Precise analysis of GH secretion pattern is vitally important for a comprehensive understanding of the function of GH and the components that regulate GH secretion pattern.
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Affiliation(s)
- Lili Huang
- School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Australia
| | - Zhengxiang Huang
- School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Australia
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Australia.
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32
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Mani BK, Castorena CM, Vianna CR, Lee CE, Metzger NP, Vijayaraghavan P, Osborne-Lawrence S, Elmquist JK, Zigman JM. Combined Loss of Ghrelin Receptor and Cannabinoid CB1 Receptor in Mice Decreases Survival but does not Additively Reduce Body Weight or Eating. Neuroscience 2019; 447:53-62. [PMID: 31520709 DOI: 10.1016/j.neuroscience.2019.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/28/2019] [Accepted: 09/02/2019] [Indexed: 01/08/2023]
Abstract
Ghrelin administration increases food intake, body weight (BW), adiposity, and blood glucose. In contrast, although mouse models lacking ghrelin or its receptor (Growth Hormone Secretagogue Receptor (GHSR)) exhibit life-threatening hypoglycemia in starvation-like states, they do not exhibit appreciable reductions in food intake, BW, adiposity, blood glucose, or survival when food availability is unrestricted. This suggests the existence of a parallel neuromodulatory system that can compensate for disruptions in the ghrelin system in certain settings. Here, we hypothesized that the cannabinoid CB1 receptor (CB1R) may encode this putative redundancy, and as such, that genetic deletion of both GHSR and CB1R would exaggerate the metabolic deficits associated with deletion of GHSR alone. To test this hypothesis, we assessed food intake, BW, blood glucose, survival, and plasma acyl-ghrelin in ad libitum-fed male wild-type mice and those that genetically lack GHSR (GHSR-nulls), CB1R (CB1R-nulls), or both GHSR and CB1R (double-nulls). BW, fat mass, and lean mass were similar in GHSR-nulls and wild-types, lower in CB1R-nulls, but not further reduced in double-nulls. Food intake, plasma acyl-ghrelin, and blood glucose were similar among genotypes. Deletion of either GHSR or CB1R alone did not have a statistically-significant effect on survival, but double-nulls demonstrated a statistical trend towards decreased survival (p = 0.07). We conclude that CB1R is not responsible for the normal BW, adiposity, food intake, and blood glucose observed in GHSR-null mice in the setting of unrestricted food availability. Nor is CB1R required for plasma acyl-ghrelin secretion in that setting. However, GHSR may be protective against exaggerated mortality associated with CB1R deletion.
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Affiliation(s)
- Bharath K Mani
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carlos M Castorena
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Claudia R Vianna
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Charlotte E Lee
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nathan P Metzger
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prasanna Vijayaraghavan
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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33
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Bake T, Edvardsson CE, Cummings CJ, Dickson SL. Ghrelin's effects on food motivation in rats are not limited to palatable foods. J Neuroendocrinol 2019; 31:e12665. [PMID: 30525248 PMCID: PMC6767751 DOI: 10.1111/jne.12665] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/17/2018] [Accepted: 11/29/2018] [Indexed: 12/20/2022]
Abstract
The "hunger" hormone, ghrelin, is powerfully orexigenic. Even in the absence of hunger, ghrelin delivery to rats increases consumption of chow, as well as palatable foods, and increases motivated behaviour for palatable food rewards. Inspired by the finding that ghrelin increases the selection of chow in rats offered a choice diet (lard, sucrose or chow) and even in rats bingeing on a high-fat diet, we aimed to explore whether the effects of ghrelin on motivation extend to regular chow. Rats were conditioned to lever press for either chow or sucrose pellets in a progressive ratio (PR) operant conditioning task. The effect of acute i.c.v. delivery of ghrelin on both chow and sucrose self-administration was determined and compared with overnight fasting (ie, when endogenous ghrelin levels are elevated). We found that ghrelin similarly increased motivated behaviour for chow and sucrose pellets. The effect of fasting on motivated behaviour for both food pellets was comparable in magnitude to that induced by ghrelin, albeit with an earlier ceiling effect during the PR session. Devaluation experiments (in which rats are offered either food reinforcer in excess prior to PR testing) did not support the hypothesis that sucrose pellets would be more difficult to devalue (as a result of their higher incentive value) than chow pellets. When exchanging the respective pellets during a PR session, chow-conditioned rats were more motivated for sucrose pellets compared to chow pellets; however, sucrose-conditioned rats were similarly motivated for chow pellets compared to sucrose pellets. Thus, using sucrose as a reward may increase the motivation even for less palatable foods. We conclude that the impact of ghrelin on food-motivated behaviour in fed rats is not limited to palatable foods but extends to regular chow, and also that the magnitude of the effect is considerable compared to that of an overnight fast.
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Affiliation(s)
- Tina Bake
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
| | - Christian E. Edvardsson
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
| | - Cameron J. Cummings
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
| | - Suzanne L. Dickson
- Department of Physiology/EndocrineInstitute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
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Abizaid A. Stress and obesity: The ghrelin connection. J Neuroendocrinol 2019; 31:e12693. [PMID: 30714236 DOI: 10.1111/jne.12693] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/01/2019] [Accepted: 01/29/2019] [Indexed: 12/20/2022]
Abstract
Ghrelin is a hormone associated with feeding and energy balance. Not surprisingly, this hormone is secreted in response to acute stressors and it is chronically elevated after exposure to chronic stress in tandem with a number of metabolic changes aimed at attaining homeostatic balance. In the present review, we propose that ghrelin plays a key role in these stress-induced homeostatic processes. Ghrelin targets the hypothalamus and brain stem nuclei that are part of the sympathetic nervous system to increase appetite and energy expenditure and promote the use of carbohydrates as a source of fuel at the same time as sparing fat. Ghrelin also targets mesolimbic brain regions such as the ventral segmental area and the hippocampus to modulate reward processes, to protect against damage associated with chronic stress, as well as to potentially increase resilience to stress. In all, these data support the notion that ghrelin, similar to corticosterone, is a critical metabolic hormone that is essential for the stress response.
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Affiliation(s)
- Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
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35
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Baldini G, Phelan KD. The melanocortin pathway and control of appetite-progress and therapeutic implications. J Endocrinol 2019; 241:R1-R33. [PMID: 30812013 PMCID: PMC6500576 DOI: 10.1530/joe-18-0596] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 01/22/2019] [Indexed: 12/19/2022]
Abstract
The initial discovery that ob/ob mice become obese because of a recessive mutation of the leptin gene has been crucial to discover the melanocortin pathway to control appetite. In the melanocortin pathway, the fed state is signaled by abundance of circulating hormones such as leptin and insulin, which bind to receptors expressed at the surface of pro-opiomelanocortin (POMC) neurons to promote processing of POMC to the mature hormone α-melanocyte-stimulating hormone (α-MSH). The α-MSH released by POMC neurons then signals to decrease energy intake by binding to melanocortin-4 receptor (MC4R) expressed by MC4R neurons to the paraventricular nucleus (PVN). Conversely, in the 'starved state' activity of agouti-related neuropeptide (AgRP) and of neuropeptide Y (NPY)-expressing neurons is increased by decreased levels of circulating leptin and insulin and by the orexigenic hormone ghrelin to promote food intake. This initial understanding of the melanocortin pathway has recently been implemented by the description of the complex neuronal circuit that controls the activity of POMC, AgRP/NPY and MC4R neurons and downstream signaling by these neurons. This review summarizes the progress done on the melanocortin pathway and describes how obesity alters this pathway to disrupt energy homeostasis. We also describe progress on how leptin and insulin receptors signal in POMC neurons, how MC4R signals and how altered expression and traffic of MC4R change the acute signaling and desensitization properties of the receptor. We also describe how the discovery of the melanocortin pathway has led to the use of melanocortin agonists to treat obesity derived from genetic disorders.
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Affiliation(s)
- Giulia Baldini
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kevin D. Phelan
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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36
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Hsieh PN, Fan L, Sweet DR, Jain MK. The Krüppel-Like Factors and Control of Energy Homeostasis. Endocr Rev 2019; 40:137-152. [PMID: 30307551 PMCID: PMC6334632 DOI: 10.1210/er.2018-00151] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/05/2018] [Indexed: 12/16/2022]
Abstract
Nutrient handling by higher organisms is a complex process that is regulated at the transcriptional level. Studies over the past 15 years have highlighted the critical importance of a family of transcriptional regulators termed the Krüppel-like factors (KLFs) in metabolism. Within an organ, distinct KLFs direct networks of metabolic gene targets to achieve specialized functions. This regulation is often orchestrated in concert with recruitment of tissue-specific transcriptional regulators, particularly members of the nuclear receptor family. Upon nutrient entry into the intestine, gut, and liver, KLFs control a range of functions from bile synthesis to intestinal stem cell maintenance to effect nutrient acquisition. Subsequently, coordinated KLF activity across multiple organs distributes nutrients to sites of storage or liberates them for use in response to changes in nutrient status. Finally, in energy-consuming organs like cardiac and skeletal muscle, KLFs tune local metabolic programs to precisely match substrate uptake, flux, and use, particularly via mitochondrial function, with energetic demand; this is achieved in part via circulating mediators, including glucocorticoids and insulin. Here, we summarize current understanding of KLFs in regulation of nutrient absorption, interorgan circulation, and tissue-specific use.
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Affiliation(s)
- Paishiun N Hsieh
- Case Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio.,Department of Pathology, Case Western Reserve University, Cleveland, Ohio
| | - Liyan Fan
- Case Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio.,Department of Pathology, Case Western Reserve University, Cleveland, Ohio
| | - David R Sweet
- Case Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio.,Department of Pathology, Case Western Reserve University, Cleveland, Ohio
| | - Mukesh K Jain
- Case Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio.,Harrington Heart and Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio
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Song X, Jiao H, Zhao J, Wang X, Lin H. Ghrelin serves as a signal of energy utilization and is involved in maintaining energy homeostasis in broilers. Gen Comp Endocrinol 2019; 272:76-82. [PMID: 30508509 DOI: 10.1016/j.ygcen.2018.11.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 11/06/2018] [Accepted: 11/30/2018] [Indexed: 12/15/2022]
Abstract
Ghrelin, one of the most important appetite regulating peptides, is involved in the regulation of energy homeostasis. The anorexia effect of ghrelin in chickens is contrary to that of ghrelin in mammals. In the present study, the effects of feeding status and dietary energy level on plasma total ghrelin levels and expression were studied in broilers. The gene expression of ghrelin and its receptor GHS-R1a were measured in the hypothalamus, proventriculus, duodenum, liver, and abdominal fat pad. The results showed that ghrelin mRNA and GHS-R1a mRNA are moderately expressed in liver and abdominal fat. Ghrelin secretion was increased by fasting and refeeding. The gene expression of ghrelin and GHS-R1a in the hypothalamus, proventriculus, liver, and abdominal fat pad were changed by feeding status and dietary energy level. The results suggest that ghrelin is a signal of energy utilization in chickens. The abundant expression of ghrelin and GHS-R1a in liver and abdominal fat pad may be associated with energy balance.
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Affiliation(s)
- Xixi Song
- College of Animal Science and Technology, Shandong Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, No. 61 Daizong Street, Taian 271018, PR China
| | - Hongchao Jiao
- College of Animal Science and Technology, Shandong Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, No. 61 Daizong Street, Taian 271018, PR China
| | - Jingpeng Zhao
- College of Animal Science and Technology, Shandong Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, No. 61 Daizong Street, Taian 271018, PR China
| | - Xiaojuan Wang
- College of Animal Science and Technology, Shandong Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, No. 61 Daizong Street, Taian 271018, PR China
| | - Hai Lin
- College of Animal Science and Technology, Shandong Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, No. 61 Daizong Street, Taian 271018, PR China.
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38
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Li XH, Zhou XM, Li XJ, Liu YY, Liu Q, Guo XL, Yang LQ, Chen JX. Effects of Xiaoyaosan on the Hippocampal Gene Expression Profile in Rats Subjected to Chronic Immobilization Stress. Front Psychiatry 2019; 10:178. [PMID: 31031647 PMCID: PMC6474260 DOI: 10.3389/fpsyt.2019.00178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 03/11/2019] [Indexed: 12/28/2022] Open
Abstract
Objective: This study examined the effect of Xiaoyaosan and its anti-stress mechanism in rats subjected to chronic immobilization stress at the whole genome level. Methods: Rat whole genome expression chips (Illumina) were used to detect differences in hippocampal gene expression in rats from the control group (CN group), model group (M group) and Xiaoyaosan group (XYS group) that were subjected to chronic immobilization stress. The Gene Ontology terms and signaling pathways that were altered in the hippocampus gene expression profile were analyzed. The network regulating the transcription of the differentially expressed genes was also established. To verify the results from the gene chips, real-time quantitative polymerase chain reaction was used to determine the expression of the GABRA1, FADD, CRHR2, and CDK6 genes in hippocampal tissues. In situ hybridization (ISH) and immunohistochemistry were used to determine the expression of the GABRA1 and CRHR2 genes and proteins, respectively. Results: Compared with the CN group, 566 differentially expressed genes were identified in the M group. Compared with the M group, 544 differentially expressed genes were identified in the XYS group. In the M and XYS groups, multiple significantly upregulated or downregulated genes functioned in various biological processes. The cytokine receptor interaction pathway was significantly inhibited in the hippocampus of the model group. The actin cytoskeleton regulation pathway was significantly increased in the hippocampus of the XYS group. The inhibition of hippocampal cell growth was the core molecular event of network regulating the transcription of the differentially expressed genes in the model group. Promotion of the regeneration of hippocampal neurons was the core molecular event of the transcriptional regulatory network in the XYS group. The levels of the GABRA1, FADD, CRHR2 and CDK6 mRNAs, and proteins were basically consistent with the results obtained from the gene chip. Conclusion: XYS may have the ability of resistance to stress, enhancement immunity and promotion nerve cell regeneration by regulating the expression of multiple genes in numerous pathways and repaired the stress-induced impairments in hippocampal structure and function by inducing cytoskeletal reorganization. These results may provide the possible target spots in the treatment of stress in rats with XYS.
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Affiliation(s)
- Xiao-Hong Li
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,School of Basic Medical Sciences, Guangxi University of Chinese Medicine, Nanning, China
| | - Xue-Ming Zhou
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Xiao-Juan Li
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Formula-pattern Research Center, School of Traditional Chinese Medicine, Jinan University, Guangzhou, China
| | - Yue-Yun Liu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Qun Liu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Xiao-Ling Guo
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Li-Qiang Yang
- School of Basic Medical Sciences, Guangxi University of Chinese Medicine, Nanning, China
| | - Jia-Xu Chen
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Formula-pattern Research Center, School of Traditional Chinese Medicine, Jinan University, Guangzhou, China
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Maugham ML, Seim I, Thomas PB, Crisp GJ, Shah ET, Herington AC, Brown KA, Gregory LS, Nelson CC, Jeffery PL, Chopin LK. No effect of unacylated ghrelin administration on subcutaneous PC3 xenograft growth or metabolic parameters in a Rag1-/- mouse model of metabolic dysfunction. PLoS One 2018; 13:e0198495. [PMID: 30458004 PMCID: PMC6245673 DOI: 10.1371/journal.pone.0198495] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 11/02/2018] [Indexed: 12/12/2022] Open
Abstract
Ghrelin is a peptide hormone which, when acylated, regulates appetite, energy balance and a range of other biological processes. Ghrelin predominately circulates in its unacylated form (unacylated ghrelin; UAG). UAG has a number of functions independent of acylated ghrelin, including modulation of metabolic parameters and cancer progression. UAG has also been postulated to antagonise some of the metabolic effects of acyl-ghrelin, including its effects on glucose and insulin regulation. In this study, Rag1-/- mice with high-fat diet-induced obesity and hyperinsulinaemia were subcutaneously implanted with PC3 prostate cancer xenografts to investigate the effect of UAG treatment on metabolic parameters and xenograft growth. Daily intraperitoneal injection of 100 μg/kg UAG had no effect on xenograft tumour growth in mice fed normal rodent chow or 23% high-fat diet. UAG significantly improved glucose tolerance in host Rag1-/- mice on a high-fat diet, but did not significantly improve other metabolic parameters. We propose that UAG is not likely to be an effective treatment for prostate cancer, with or without associated metabolic syndrome.
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Affiliation(s)
- Michelle L. Maugham
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Skeletal Biology and Forensic Anthropology Research Laboratory, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Inge Seim
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Patrick B. Thomas
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Gabrielle J. Crisp
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Esha T. Shah
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Adrian C. Herington
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kristy A. Brown
- Department of Medicine, Weill Cornell Medicine, New York City, New York, United States of America
| | - Laura S. Gregory
- Skeletal Biology and Forensic Anthropology Research Laboratory, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Colleen C. Nelson
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Penny L. Jeffery
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Lisa K. Chopin
- Ghrelin Research Group, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Australian Prostate Cancer Research Centre - Queensland, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Comparative and Endocrine Biology Laboratory, Translational Research Institute – Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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Song X, Jiao H, Zhao J, Wang X, Lin H. Dexamethasone and insulin stimulate ghrelin secretion of broilers in a different way. Gen Comp Endocrinol 2018; 268:14-21. [PMID: 30016627 DOI: 10.1016/j.ygcen.2018.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/06/2018] [Accepted: 07/13/2018] [Indexed: 12/27/2022]
Abstract
Ghrelin is one of the most important appetite regulating peptides, involved in the regulation of energy homeostasis. The role of ghrelin on the appetite and fat metabolism in chickens is different from that of ghrelin in mammals. Glucocorticoids and insulin are important hormones and work differently in energy regulation of body. In this study, the effects of dexamethasone (DEX, 2.0 mg/kg BW), subcutaneous insulin injection (40 µg/kg BW), and glucose load on ghrelin secretion and expression were determined in broilers. DEX treatment increased circulating ghrelin concentration in broiler fed with either a low-energy diet (11.05 MJ/kg of metabolizable energy) or a high-energy diet (14.44 MJ/kg of metabolizable energy). The expression levels of ghrelin were increased while both ghrelin and its receptor GHS-R1a expression levels were stimulated by DEX. A single subcutaneous insulin injection (40 µg/kg BW) or oral glucose infusion (2 g/kg BW) rise circulating ghrelin level. Ghrelin expression in the proventriculus was increased by insulin treatment but unchanged by glucose load. DEX had no detectable influence on ghrelin and GHS-R1a expression in the hypohtalamus, whereas insulin suppressed their expression. In conclusion, both insulin and glucocorticoid stimulate ghrelin secretion in chickens, in contrast to mammals. Glucocorticoids evoke peripheral ghrelin/GHS-R1a system while insulin increases peripheral ghrelin expression and suppress the activation of central ghrelin/GHS-R1a system. The result suggests that ghrelin involved in the modulating network of energy homeostasis in concert with glucocorticoids and insulin.
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Affiliation(s)
- Xixi Song
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, No. 61 Daizong Street, Tai'an 271018, PR China
| | - Hongchao Jiao
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, No. 61 Daizong Street, Tai'an 271018, PR China
| | - Jingpeng Zhao
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, No. 61 Daizong Street, Tai'an 271018, PR China
| | - Xiaojuan Wang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, No. 61 Daizong Street, Tai'an 271018, PR China
| | - Hai Lin
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, No. 61 Daizong Street, Tai'an 271018, PR China.
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Sztainert T, Hay R, Wohl MJA, Abizaid A. Hungry to gamble? Ghrelin as a predictor of persistent gambling in the face of loss. Biol Psychol 2018; 139:115-123. [PMID: 30392826 DOI: 10.1016/j.biopsycho.2018.10.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 10/18/2018] [Accepted: 10/18/2018] [Indexed: 01/08/2023]
Abstract
Ghrelin, a peptide hormone associated with appetite, is also linked to increased reward seeking behaviors, including food, sex, and drug seeking behaviors through the stimulation of the mesolimbic dopaminergic system. Moreover, plasma ghrelin concentrations are increased by cues that predict rewards, suggesting that cues could facilitate cravings and ultimately relapse. In this project we examined the effects of an overnight fast, a manipulation known to increase ghrelin concentrations, on gambling behaviors. We also examined if cues associated with gambling would also increase ghrelin and, if so, we examined if these increases were associated with gambling behavior. One hundred and one (37 females) participants were asked to fast overnight or after breakfast and then asked to complete food and gambling craving questionnaires. Participants were then presented with gambling cues (a casino like environment in the lab) or a control cue (a cubicle with a computer). After the cue, subjects filled gambling craving questionnaires, and were allowed to gamble. Following 25 practice spins, the slot machines were fixed so that all subsequent spins were losses, and the number of spins in spite of losses were quantified. Blood samples were collected throughout the experiment. Results showed that the gambling cues significantly increased ghrelin concentrations particularly in fasted individuals, and that ghrelin concentrations 20 min after the cue were the best predictor for gambling persistence in the face of continued loss (p < 0.05). Our results suggest that cues that predict the opportunity to gamble have an acute effect on ghrelin concentrations that is facilitated by fasting, and that ghrelin concentrations are a significant predictor of gambling persistence.
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Affiliation(s)
| | - Rebecca Hay
- Carleton University Department of Neuroscience, Canada
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43
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Pope CN, Brimijoin S. Cholinesterases and the fine line between poison and remedy. Biochem Pharmacol 2018; 153:205-216. [PMID: 29409903 PMCID: PMC5959757 DOI: 10.1016/j.bcp.2018.01.044] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 01/26/2018] [Indexed: 12/20/2022]
Abstract
Acetylcholinesterase (AChE, EC 3.1.1.7) and butyrylcholinesterase (BChE, EC 3.1.1.8) are related enzymes found across the animal kingdom. The critical role of acetylcholinesterase in neurotransmission has been known for almost a century, but a physiological role for butyrylcholinesterase is just now emerging. The cholinesterases have been deliberately targeted for both therapy and toxicity, with cholinesterase inhibitors being used in the clinic for a variety of disorders and conversely for their toxic potential as pesticides and chemical weapons. Non-catalytic functions of the cholinesterases (ChEs) participate in both neurodevelopment and disease. Manipulating either the catalytic activities or the structure of these enzymes can potentially shift the balance between beneficial and adverse effect in a wide number of physiological processes.
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Affiliation(s)
- Carey N Pope
- Department of Physiological Sciences, Interdisciplinary Toxicology Program, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Stephen Brimijoin
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55902, USA
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Ikenoya C, Takemi S, Kaminoda A, Aizawa S, Ojima S, Gong Z, Chacrabati R, Kondo D, Wada R, Tanaka T, Tsuda S, Sakai T, Sakata I. β-Oxidation in ghrelin-producing cells is important for ghrelin acyl-modification. Sci Rep 2018; 8:9176. [PMID: 29907775 PMCID: PMC6003948 DOI: 10.1038/s41598-018-27458-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 06/01/2018] [Indexed: 12/30/2022] Open
Abstract
Ghrelin is a unique fatty acid-modified peptide hormone produced in the stomach and has important roles in energy homeostasis and gastrointestinal motility. However, the medium-chain fatty acid source for ghrelin acyl-modification is not known. We found that a fat-free diet and the removal of intestinal microbiota did not decrease acyl-ghrelin production in the stomach or plasma acyl-ghrelin levels in mice. RT-PCR analysis showed that genes involving fatty acid synthesis, metabolism, and transport were expressed in pancreas-derived ghrelinoma (PG-1) cells. Treatment with an irreversible inhibitor of carnitine palmitoyltransferase-1 (CPT-1) strongly decreased acylated ghrelin levels but did not affect ghrelin or ghrelin o-acyl transferase (GOAT) mRNA levels in PG-1 cells. Our results suggest that the medium-chain fatty acid used for the acyl-modification of ghrelin is produced in ghrelin-producing cells themselves by β-oxidation of long-chain fatty acids provided from the circulation.
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Affiliation(s)
- Chika Ikenoya
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Shota Takemi
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Arisa Kaminoda
- Department of Biology, Graduate School of Natural Science and Technology, Okayama University, 3-1-1, Tsushimanaka, Kita-ku, Okayama, 700-8530, Japan
| | - Sayaka Aizawa
- Department of Biology, Graduate School of Natural Science and Technology, Okayama University, 3-1-1, Tsushimanaka, Kita-ku, Okayama, 700-8530, Japan
| | - Shiomi Ojima
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Zhi Gong
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Rakhi Chacrabati
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Daisuke Kondo
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Reiko Wada
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Toru Tanaka
- Faculty of Pharmaceutical Sciences, Department of Pharmaceutical and Health Sciences, Josai University, 1-1 Keiyaki dai, Sakado, Saitama, 350-0295, Japan
| | - Sachiko Tsuda
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan.,Research and Development Bureau, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan
| | - Takafumi Sakai
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan.,Area of Life-NanoBio, Division of Strategy Research, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama, 338-8570, Japan.
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Jabbari M, Kheirouri S, Alizadeh M. Decreased Serum Levels of Ghrelin and Brain-Derived Neurotrophic Factor in Premenopausal Women With Metabolic Syndrome. Lab Med 2018; 49:140-146. [PMID: 29346609 DOI: 10.1093/labmed/lmx087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Objective We aimed to investigate the association between serum levels of ghrelin and brain-derived neurotrophic factor (BDNF) with MetS and its components in premenopausal women. Methods 43 patients with MetS and 43 healthy controls participated in this study. Participants' body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressure (SBP and DBP) were measured. Serum levels of total cholesterol (TC), triglyceride (TG), low and high density lipoprotein cholesterol (LDL-C and HDL-C), fasting blood sugar (FBS), insulin, BDNF and ghrelin determined. Homeostasis model assessment insulin resistance index (HOMA-IR) was also calculated. Results Participants in MetS group had higher waist-to-hip ratios, elevated SBP and DBP, and higher serum levels of TG, FBS and insulin when compared with the control group. Serum ghrelin and BDNF levels were significantly lower in participants with MetS than in the healthier control subjects. There was a strong, positive correlation between serum ghrelin and BDNF levels. Both proteins negatively correlated with TG, FBS, HOMA-IR and positively with HDL-C. Furthermore, serum BDNF levels negatively associated with insulin levels. Conclusions The findings indicate that variations occur in the circulating level of ghrelin and BDNF proteins in MetS patients. A strong correlation between serum ghrelin and BDNF suggests that production, release or practice of these 2 proteins might be related mechanically.
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Affiliation(s)
- Masoumeh Jabbari
- Department of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sorayya Kheirouri
- Department of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Alizadeh
- Department of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran
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Abstract
Ghrelin, a gastric-derived acylated peptide, regulates energy homeostasis by transmitting information about peripheral nutritional status to the brain, and is essential for protecting organisms against famine. Ghrelin operates brain circuits to regulate homeostatic and hedonic feeding. Recent research advances have shed new light on ghrelin's multifaceted roles in cellular homeostasis, which could maintain the internal environment and overcome metaflammation in metabolic organs. Here, we highlight our current understanding of the regulatory mechanisms of the ghrelin system in energy metabolism and cellular homeostasis and its clinical trials. Future studies of ghrelin will further elucidate how the stomach regulates systemic homeostasis.
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Affiliation(s)
- Shigehisa Yanagi
- Divisions of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan
| | - Takahiro Sato
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume 839-0864, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Masamitsu Nakazato
- Divisions of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan.
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Abstract
Islets of Langerhans are islands of endocrine cells scattered throughout the pancreas. A number of new studies have pointed to the potential for conversion of non-β islet cells in to insulin-producing β-cells to replenish β-cell mass as a means to treat diabetes. Understanding normal islet cell mass and function is important to help advance such treatment modalities: what should be the target islet/β-cell mass, does islet architecture matter to energy homeostasis, and what may happen if we lose a particular population of islet cells in favour of β-cells? These are all questions to which we will need answers for islet replacement therapy by transdifferentiation of non-β islet cells to be a reality in humans. We know a fair amount about the biology of β-cells but not quite as much about the other islet cell types. Until recently, we have not had a good grasp of islet mass and distribution in the human pancreas. In this review, we will look at current data on islet cells, focussing more on non-β cells, and on human pancreatic islet mass and distribution.
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Affiliation(s)
- Gabriela Da Silva Xavier
- Section of Functional Genomics and Cell Biology, Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Edgbaston B15 2TT, UK.
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Kang SJ, Kim JH, Gang Z, Yook YS, Yoon JR, Ha GC, Ko KJ. Effects of 12-week circuit exercise program on obesity index, appetite regulating hormones, and insulin resistance in middle-aged obese females. J Phys Ther Sci 2018; 30:169-173. [PMID: 29410591 PMCID: PMC5788800 DOI: 10.1589/jpts.30.169] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 10/30/2017] [Indexed: 02/05/2023] Open
Abstract
[Purpose] The purpose of this study is to investigate the effects of circuit exercise on
obesity index, appetite regulating hormones and insulin resistance in middle-aged obese
women. [Subjects and Methods] The subjects of this study were 26 obese middle-aged women
who were selected among participants in exercise class at K Region Health Promotion Center
in South Korea and were randomly assigned to the exercise group (n=13; age 50.15 ± 3.82, %
body fat 38.79 ± 3.28) and the control group (n=13; age 49.84 ± 2.96, % body fat 37.46 ±
2.51). Circuit exercise consisted of aerobic exercise and resistance exercise for 5 weeks
and 50 minutes for 12 weeks. Before and after exercise we measured obesity index, leptin,
ghrelin, fasting blood glucose, insulin, and insulin resistance in all subjects. A
repeated-measured two-way of variance was performed for comparison of the treatment
effects between the exercise and control groups. [Results] Body weight, BMI, and body fat
percentage of obese index decreased significantly. Leptin of dietary regulation hormone
was significantly decreased and ghrelin was significantly increased. Insulin and insulin
resistance was significantly decreased. [Conclusion] Circuit exercise can be viewed as an
effective exercise program to induce changes in appetite regulating hormones and to
improve insulin resistance by mechanisms of energy homeostasis by weight loss.
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Affiliation(s)
- Seol-Jung Kang
- Department of Physical Education, Changwon National University, Republic of Korea
| | - Jong-Hyu Kim
- Health Care Center, Department of Preventive Medicine, Chonbuk National University, Republic of Korea
| | - Zhao Gang
- Department of Physical Education, Shenzhen University, China
| | - Young-Sook Yook
- Department of Exercise Rehabilitation Welfare, Sungshin Women's University, Republic of Korea
| | - Jea-Ryang Yoon
- Department of Physical Education, Korea National Sport University, Republic of Korea
| | - Gi-Chul Ha
- Department of Physical Education, Korea National Sport University, Republic of Korea
| | - Kwang-Jun Ko
- Department of Sports Medicine, National Health Fitness Center: 424 Olympicro, Songpagu, Seoul 05540, Republic of Korea
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Ren P, Yang XJ, Kim JS, Menon D, Pangeni D, Manu H, Tekeste A, Baidoo SK. Plasma acyl ghrelin and nonesterified fatty acids are the best predictors for hunger status in pregnant gilts. J Anim Sci 2018; 95:5485-5496. [PMID: 29293797 DOI: 10.2527/jas2017.1785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Sows are usually restricted fed during pregnancy to maximize their reproductive efficiency, which may predispose sows to a state of hunger. However, an objective measurement of hunger status has not been established. In the present study, we examined the correlation of plasma hormones and NEFA and selected the best predictors for hunger status using pregnant gilts. Three different levels of feed intake (0.5, 1.0 and 2.0 × maintenance energy intake [0.5M, 1.0M and 2.0M, respectively]) were imposed from Day 28 to 34 of gestation to create different hunger statuses in pregnant gilts. Plasma hormones related to energy homeostasis and NEFA were analyzed to quantify their response to different levels of feed intake. A total of 18 gilts (197.53 ± 6.41 kg) were allotted to 1 of 3 dietary treatments using a completely randomized design. Results showed that BW change, ADG, and G:F from Day 28 to 34 of gestation were higher ( < 0.01) for gilts on the 2.0M feeding level than for gilts on the 0.5M feeding level. Plasma acyl ghrelin concentrations showed a relatively flat pattern during the 24-h period. Plasma acyl ghrelin and NEFA concentrations and areas under the curve (AUC) were greater ( < 0.05) in gilts on the 0.5M level of feed intake than in those on the 2.0M level of feed intake. No differences were observed among the 3 feeding levels in terms of plasma glucagon-like peptide 1 and leptin concentrations. Additionally, consumption time for 1.82 kg feed on Day 35 of gestation was longer ( < 0.01) in gilts fed the 2.0M level of feed intake from Day 28 to 34 of gestation than in those on the 0.5M level of feed intake. Simple linear regression results showed that the AUC of acyl ghrelin was the best predictor for consumption time ( = 0.82), whereas the AUC of NEFA was the best predictor for BW ( = 0.55) or backfat change ( = 0.42) from Day 28 to 34 of gestation. In conclusion, our data suggested that a relative flat pattern existed in pregnant gilts in terms of the diurnal plasma profile of acyl ghrelin and that the level of feed intake of pregnant gilts was negatively correlated with plasma concentrations of acyl ghrelin and NEFA, which, in turn, were negatively associated with feed consumption time. The AUC of acyl ghrelin and NEFA seemed to be the best predictors for hunger status of pregnant gilts.
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Mani BK, Zigman JM. Ghrelin as a Survival Hormone. Trends Endocrinol Metab 2017; 28:843-854. [PMID: 29097101 PMCID: PMC5777178 DOI: 10.1016/j.tem.2017.10.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/03/2017] [Accepted: 10/05/2017] [Indexed: 12/22/2022]
Abstract
Ghrelin administration induces food intake and body weight gain. Based on these actions, the ghrelin system was initially proposed as an antiobesity target. Subsequent studies using genetic mouse models have raised doubts about the role of the endogenous ghrelin system in mediating body weight homeostasis or obesity. However, this is not to say that the endogenous ghrelin system is not important metabolically or otherwise. Here we review an emerging concept in which the endogenous ghrelin system serves an essential function during extreme nutritional and psychological challenges to defend blood glucose, protect body weight, avoid exaggerated depression, and ultimately allow survival.
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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, 5323 Harry Hines Blvd, Dallas, TX 75390-9077, USA
| | - Jeffrey M Zigman
- Divisions of Hypothalamic Research and Endocrinology, Department of Internal Medicine, and Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9077, USA.
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