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Villarreal D, Pradhan G, Zhou Y, Xue B, Sun Y. Diverse and Complementary Effects of Ghrelin and Obestatin. Biomolecules 2022; 12:biom12040517. [PMID: 35454106 PMCID: PMC9028691 DOI: 10.3390/biom12040517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/21/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023] Open
Abstract
Ghrelin and obestatin are two “sibling proteins” encoded by the same preproghrelin gene but possess an array of diverse and complex functions. While there are ample literature documenting ghrelin’s functions, the roles of obestatin are less clear and controversial. Ghrelin and obestatin have been perceived to be antagonistic initially; however, recent studies challenge this dogma. While they have opposing effects in some systems, they function synergistically in other systems, with many functions remaining debatable. In this review, we discuss their functional relationship under three “C” categories, namely complex, complementary, and contradictory. Their functions in food intake, weight regulation, hydration, gastrointestinal motility, inflammation, and insulin secretion are complex. Their functions in pancreatic beta cells, cardiovascular, muscle, neuroprotection, cancer, and digestive system are complementary. Their functions in white adipose tissue, thermogenesis, and sleep regulation are contradictory. Overall, this review accumulates the multifaceted functions of ghrelin and obestatin under both physiological and pathological conditions, with the intent of contributing to a better understanding of these two important gut hormones.
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Affiliation(s)
- Daniel Villarreal
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
| | - Geetali Pradhan
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao 266071, China;
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA;
| | - Yuxiang Sun
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Correspondence: ; Tel.: +1-979-862-9143
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Neurohormonal Changes in the Gut–Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery. Int J Mol Sci 2022; 23:ijms23063339. [PMID: 35328759 PMCID: PMC8954280 DOI: 10.3390/ijms23063339] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 02/05/2023] Open
Abstract
Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut–brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut–brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.
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Şen LS, Özdemir Kumral ZN, Memi G, Ercan F, Yeğen BC, Yeğen C. The gastroprotective effect of obestatin on indomethacin-induced acute ulcer is mediated by a vagovagal mechanism. Physiol Int 2020; 107:243-255. [PMID: 32692714 DOI: 10.1556/2060.2020.00025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 02/17/2020] [Indexed: 12/12/2022]
Abstract
In order to investigate the role of the vagus nerve in the possible gastroprotective effect of obestatin on the indomethacin-induced acute oxidative gastric injury, Sprague-Dawley rats of both sexes were injected subcutaneously with indomethacin (25 mg/kg, 5% NaHCO3) followed by obestatin (10, 30 or 100 μg/kg). In other sets of rats, surgical vagotomy (Vx) or selective degeneration of vagal afferent fibers by perivagal capsaicin was performed before the injections of indomethacin or indomethacin + obestatin (30 μg/kg). Gastric serosal blood flow was measured, and 4 h after ulcer induction gastric tissue samples were taken for histological and biochemical assays. Obestatin reduced the severity of indomethacin-induced acute ulcer via the reversal of reactive hyperemia, by inhibiting ulcer-induced neutrophil infiltration and lipid peroxidation along with the replenishment of glutathione (GSH) stores, whereas Vx abolished the inhibitory effect of obestatin on blood flow and lipid peroxidation, and worsened the severity of ulcer. On the other hand, serosal blood flow was even amplified by the selective denervation of the capsaicin-sensitive vagal afferent fibers, but obestatin-induced reduction in ulcer severity was not altered. In conclusion, the gastroprotective effect of obestatin on indomethacin-induced ulcer appears to involve the activation of the vagovagal pathway.
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Affiliation(s)
- Leyla Semiha Şen
- 1Department of Physiology, Marmara University School of Medicine, İstanbul, Turkey.,3Department of General Surgery, Marmara University School of Medicine, İstanbul, Turkey
| | | | - Gülsün Memi
- 1Department of Physiology, Marmara University School of Medicine, İstanbul, Turkey
| | - Feriha Ercan
- 2Department of Histology & Embryology, Marmara University School of Medicine, İstanbul, Turkey
| | - Berrak C Yeğen
- 1Department of Physiology, Marmara University School of Medicine, İstanbul, Turkey
| | - Cumhur Yeğen
- 3Department of General Surgery, Marmara University School of Medicine, İstanbul, Turkey
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Lucka A, Wysokiński A. Association between adiposity and fasting serum levels of appetite-regulating peptides: Leptin, neuropeptide Y, desacyl ghrelin, peptide YY(1-36), obestatin, cocaine and amphetamine-regulated transcript, and agouti-related protein in nonobese participants. CHINESE J PHYSIOL 2019; 62:217-225. [PMID: 31670286 DOI: 10.4103/cjp.cjp_29_19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The objective of this study was to evaluate the association between adiposity parameters and fasting serum levels of appetite-regulating peptides: leptin, neuropeptide Y (NPY), desacyl ghrelin, peptide YY(1-36), obestatin, cocaine- and amphetamine-regulated transcript (CART), and agouti-related protein in 30 healthy, non-obese subjects. Thirty European Caucasian adult participants were included in the study (17 men and 13 women). Body composition (body fat and lean body mass) was determined using bioelectrical impedance analysis. Concentrations of peptides in serum were assessed using the enzyme-linked immunosorbent assay. Women had higher level of leptin (P < 0.001), with no other differences for analyzed peptides. We have found a significant correlation between serum concentrations of CART and NPY (P < 0.001). Fasting leptin level was associated with age (P = 0.002), waist circumference (P < 0.001), and lean body mass (P < 0.001). Levels of ghrelin were lower in participants with dyslipidemia (P = 0.009). Levels of obestatin (P = 0.008) and leptin (P = 0.02) were higher in participants with insulin resistance. Associations between body fat and appetite-regulating peptides are more complex than simple feedback loops. Leptin is probably the first signal in the pathway that regulates body fat content, as of all analyzed peptides leptin was the only one that was associated with body composition or anthropometric measurements.
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Affiliation(s)
- Anna Lucka
- Department of Old Age Psychiatry and Psychotic Disorders, Medical University of Lodz, Łódź, Poland
| | - Adam Wysokiński
- Department of Old Age Psychiatry and Psychotic Disorders, Medical University of Lodz, Łódź, Poland
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Green BD, Grieve DJ. Biochemical properties and biological actions of obestatin and its relevence in type 2 diabetes. Peptides 2018; 100:249-259. [PMID: 29412827 DOI: 10.1016/j.peptides.2017.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/15/2022]
Abstract
Obestatin was initially discovered in rat stomach extract, and although it is principally produced in the gastric mucosa, it can be found throughout the gastrointestinal tract. This 23-amino acid C-terminally amidated peptide is derived from preproghrelin and has been ascribed a wide range of metabolic effects relevant to type 2 diabetes. Obestatin reportedly inhibits gastrointestinal motility, reduces food intake and lowers body weight and improves lipid metabolism. Furthermore, it appears to exert actions on the pancreatic β-cell, most notably increasing β-cell mass and upregulating genes associated with insulin production and β-cell regeneration, with relevance to type 2 diabetes. It is becoming evident that obestatin also exerts pleiotropic effects on the cardiovascular system, possibly modulating blood pressure, endothelial function and triggering cardioprotective mechanisms, which may be important in determining cardiovascular outcomes in type 2 diabetes. Furthermore, it seems that like other gut peptides obestatin has neuroprotective properties. This review examines the biochemical properties of the obestatin peptide (its structure, sequence, stability and distribution) and the candidate receptors through which it may act. It provides a balanced examination of the reported pancreatic and extrapancreatic actions of obestatin and evaluates its potential relevance with respect to diabetes therapy, together with discussion of direct evidence linking alterations in obestatin signalling with obesity/diabetes and other diseases.
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Affiliation(s)
- Brian D Green
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5BN, UK.
| | - David J Grieve
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, BT9 7AE, UK
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Abstract
PURPOSE OF REVIEW In recent years, the role of the gastrointestinal (GI) tract in energy homeostasis through modulation of the digestion and absorption of carbohydrates and the production of incretin hormones is well recognized. RECENT FINDINGS Bariatric surgery for obesity has been a very effective method in substantially improving weight, and numerous studies have focused on intestinal adaptation after bariatric procedures. A number of structural and functional changes in the GI tract have been reported postsurgery, which could be responsible for the altered hormonal responses. Furthermore, the change in food absorption rate and the intestinal regions exposed to carbohydrates may affect blood glucose response. This review hopes to give new insights into the direct role of gut hormones, by summarising the metabolic effects of bariatric surgery.
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Affiliation(s)
- Georgios K Dimitriadis
- Division of Translational and Experimental Medicine, Clinical Sciences Research Laboratories, University of Warwick Medical School, Coventry, CV2 2DX, UK.
- Academic Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, London, W12 0NN, UK.
- Division of Translational and Experimental Medicine-Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
| | - Manpal S Randeva
- Division of Translational and Experimental Medicine, Clinical Sciences Research Laboratories, University of Warwick Medical School, Coventry, CV2 2DX, UK
| | - Alexander D Miras
- Academic Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, London, W12 0NN, UK
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Abstract
Obesity, a major risk factor for the development of diabetes mellitus, cardiovascular diseases and certain types of cancer, arises from a chronic positive energy balance that is often due to unlimited access to food and an increasingly sedentary lifestyle on the background of a genetic and epigenetic vulnerability. Our understanding of the humoral and neuronal systems that mediate the control of energy homeostasis has improved dramatically in the past few decades. However, our ability to develop effective strategies to slow the current epidemic of obesity has been hampered, largely owing to the limited knowledge of the mechanisms underlying resistance to the action of metabolic hormones such as leptin and ghrelin. The development of resistance to leptin and ghrelin, hormones that are crucial for the neuroendocrine control of energy homeostasis, is a hallmark of obesity. Intensive research over the past several years has yielded tremendous progress in our understanding of the cellular pathways that disrupt the action of leptin and ghrelin. In this Review, we discuss the molecular mechanisms underpinning resistance to leptin and ghrelin and how they can be exploited as targets for pharmacological management of obesity.
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Affiliation(s)
- Huxing Cui
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52246, USA
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Miguel López
- Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain
- Centro de Investigación Biomédica en Red-Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52246, USA
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
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Kolodziejski PA, Pruszynska-Oszmalek E, Sassek M, Kaczmarek P, Szczepankiewicz D, Billert M, Mackowiak P, Strowski MZ, Nowak KW. Changes in obestatin gene and GPR39 receptor expression in peripheral tissues of rat models of obesity, type 1 and type 2 diabetes. J Diabetes 2017; 9:353-361. [PMID: 27106635 DOI: 10.1111/1753-0407.12417] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 03/13/2016] [Accepted: 04/15/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Obestatin has a role in regulating food intake and energy expenditure, but the roles of obestatin and the GPR39 receptor in obesity and type 1 and type 2 diabetes mellitus (T1DM and T2DM, respectively) are not well understood. The aim of the present study was to investigate changes in obestatin and GPR39 in pathophysiological conditions like obesity, T1DM, and T2DM. METHODS Using rat models of diet-induced obesity (DIO), T1DM and T2DM (n = 14 per group), obestatin, its precursor protein preproghrelin, and GPR39 expression was investigated in tissues involved in glucose and lipid homeostasis regulation. Furthermore, serum obestatin and ghrelin concentrations were determined. RESULTS Serum obestatin concentrations were positively correlated with glucagon (r = 0.6456; P < 0.001) and visfatin (r = 0.5560; P < 0.001), and negatively correlated with insulin (r = -0.4362; P < 0.05), adiponectin (r = -0.3998; P < 0.05), and leptin (r = -0.4180; P < 0.05). There were differences in GPR39 and preproghrelin expression in the three animal models. Hepatic GPR39 and preproghrelin mRNA expression was greater in T1DM, T2DM, and obese rats than in lean controls, whereas pancreatic GPR39 mRNA and protein and preproghrelin mRNA expression was decreased in T1DM, T2DM, and DIO rats. Higher GPR39 and preproghrelin protein and mRNA levels were found in adipose tissues of T1DM compared with control. In adipose tissues of T2DM and DIO rats, GPR39 protein levels were lower than in lean or T1DM rats. Preproghrelin mRNA was higher in adipose tissues of T1DM, T2DM, and DIO than lean rats. CONCLUSION We hypothesize that changes in obestatin, GPR39, and ghrelin may contribute to metabolic abnormalities in T1DM, T2DM, and obesity.
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Affiliation(s)
- Pawel Antoni Kolodziejski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
- Department of Hepatology and Gastroenterology and the Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, Berlin, Germany
| | - Ewa Pruszynska-Oszmalek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - Maciej Sassek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - Przemyslaw Kaczmarek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - Dawid Szczepankiewicz
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - Maria Billert
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - Paweł Mackowiak
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - Mathias Z Strowski
- Department of Hepatology and Gastroenterology and the Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, Berlin, Germany
- Medical Clinic 1, Department of Gastroenterology, Elblandklinik, Meissen, Germany
| | - Krzysztof W Nowak
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
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Hassouna R, Labarthe A, Tolle V. Hypothalamic regulation of body growth and appetite by ghrelin-derived peptides during balanced nutrition or undernutrition. Mol Cell Endocrinol 2016; 438:42-51. [PMID: 27693419 DOI: 10.1016/j.mce.2016.09.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/25/2016] [Accepted: 09/26/2016] [Indexed: 12/16/2022]
Abstract
Among the gastrointestinal hormones that regulate food intake and energy homeostasis, ghrelin plays a unique role as the first one identified to increases appetite and stimulate GH secretion. This review highlights the latest mechanism by which ghrelin modulates body growth, appetite and energy metabolism by exploring pharmacological actions of the hormone and consequences of genetic or pharmacological blockade of the ghrelin/GHS-R (Growth Hormone Secretagogue Receptor) system on physiological responses in specific nutritional situations. Within the hypothalamus, novel mechanisms of action of this hormone involve its interaction with other ghrelin-derived peptides, such as desacyl ghrelin and obestatin, which are thought to act as functional ghrelin antagonists, and possible modulation of the GHS-R with other G-protein coupled receptors. During chronic undernutrition such as anorexia nervosa, variations of ghrelin-derived peptides may be an adaptative metabolic response to maintain normal glycemic control. Interestingly, some of ghrelin's metabolic actions are thought to be relayed through modulation of GH, an anabolic and hyperglycemic agent.
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Affiliation(s)
- Rim Hassouna
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France; Naomi Berrie Diabetes Center, Department of Pediatrics, Columbia University Medical Center, New York, NY, 10032, USA
| | - Alexandra Labarthe
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France
| | - Virginie Tolle
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France.
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Kehoe K, Van Elzen R, Verkerk R, Sim Y, Van der Veken P, Lambeir AM, De Meester I. Prolyl carboxypeptidase purified from human placenta: its characterization and identification as an apelin-cleaving enzyme. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1481-8. [PMID: 27449720 DOI: 10.1016/j.bbapap.2016.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/11/2016] [Accepted: 07/16/2016] [Indexed: 02/07/2023]
Affiliation(s)
- Kaat Kehoe
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
| | - Roos Van Elzen
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Robert Verkerk
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Yani Sim
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Pieter Van der Veken
- Laboratory of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Anne-Marie Lambeir
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Ingrid De Meester
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
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Cowan E, Burch KJ, Green BD, Grieve DJ. Obestatin as a key regulator of metabolism and cardiovascular function with emerging therapeutic potential for diabetes. Br J Pharmacol 2016; 173:2165-81. [PMID: 27111465 DOI: 10.1111/bph.13502] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/05/2016] [Accepted: 04/15/2016] [Indexed: 01/01/2023] Open
Abstract
Obestatin is a 23-amino acid C-terminally amidated gastrointestinal peptide derived from preproghrelin and which forms an α helix. Although obestatin has a short biological half-life and is rapidly degraded, it is proposed to exert wide-ranging pathophysiological actions. Whilst the precise nature of many of its effects is unclear, accumulating evidence supports positive actions on both metabolism and cardiovascular function. For example, obestatin has been reported to inhibit food and water intake, body weight gain and gastrointestinal motility and also to mediate promotion of cell survival and prevention of apoptosis. Obestatin-induced increases in beta cell mass, enhanced adipogenesis and improved lipid metabolism have been noted along with up-regulation of genes associated with beta cell regeneration, insulin production and adipogenesis. Furthermore, human circulating obestatin levels generally demonstrate an inverse association with obesity and diabetes, whilst the peptide has been shown to confer protective metabolic effects in experimental diabetes, suggesting that it may hold therapeutic potential in this setting. Obestatin also appears to be involved in blood pressure regulation and to exert beneficial effects on endothelial function, with experimental studies indicating that it may also promote cardioprotective actions against, for example, ischaemia-reperfusion injury. This review will present a critical appraisal of the expanding obestatin research area and discuss the emerging therapeutic potential of this peptide for both metabolic and cardiovascular complications of diabetes.
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Affiliation(s)
- Elaine Cowan
- Queen's University Belfast, Institute for Global Food Security, School of Biological Sciences, Belfast, UK
| | - Kerry J Burch
- Queen's University Belfast, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, UK
| | - Brian D Green
- Queen's University Belfast, Institute for Global Food Security, School of Biological Sciences, Belfast, UK
| | - David J Grieve
- Queen's University Belfast, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, UK
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Moran BM, Abdel-Wahab YHA, Vasu S, Flatt PR, McKillop AM. GPR39 receptors and actions of trace metals on pancreatic beta cell function and glucose homoeostasis. Acta Diabetol 2016; 53:279-93. [PMID: 26112416 DOI: 10.1007/s00592-015-0781-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/29/2015] [Indexed: 10/23/2022]
Abstract
AIMS G-protein-coupled receptor 39 (GPR39) has been implicated in glucose homoeostasis, appetite control and gastrointestinal tract function. METHODS This study used clonal BRIN-BD11 cells and mouse pancreatic islets to assess the insulin-releasing actions of trace metals believed to act via GPR39, and the second messenger pathways involved in mediating their effects. Micromolar concentrations of Zn(2+), Cu(2+), Ni(2+) and Co(2+) were examined under normoglycaemic and hyperglycaemic conditions. Mechanistic studies investigated changes of intracellular Ca(2+), cAMP generation and assessment of cytotoxicity by LDH release. Cellular localisation of GPR39 was determined by double immunohistochemical staining. RESULTS All trace metals (7.8-500 µmol/l) stimulated insulin release with Cu(2+) being the most potent in isolated islets, with an EC50 value of 87 μmol/l. Zn(2+) was the most selective with an EC50 value of 125 μmol/l. Enhancement of insulin secretion was also observed with Ni(2+) (179 μmol/l) and Co(2+) (190 μmol/l). These insulin-releasing effects were confirmed using clonal BRIN-BD11 cells which exhibited enhanced intracellular Ca(2+) (p < 0.05-p < 0.001) and cAMP generation (p < 0.05-p < 0.001) in response to trace metals. Oral administration of Zn(2+), Ni(2+) and Cu(2+) (50 µmol/kg together with 18 mmol/kg glucose) decreased the glycaemic excursion (p < 0.05-p < 0.01) and augmented insulin secretion (p < 0.05-p < 0.01) in NIH Swiss mice. CONCLUSIONS This study has demonstrated the presence of GPR39 and the insulinotropic actions of trace metals on BRIN-BD11 cells and pancreatic beta cells, together with their antihyperglycaemic actions in vivo. These data suggest that development of agonists capable of specifically activating GPR39 may be a useful new therapeutic approach for diabetes management.
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Affiliation(s)
- Brian M Moran
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy and Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Yasser H A Abdel-Wahab
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy and Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Srividya Vasu
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy and Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Peter R Flatt
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy and Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Aine M McKillop
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy and Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK.
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Szakács J, Csabafi K, Lipták N, Szabó G. The effect of obestatin on anxiety-like behaviour in mice. Behav Brain Res 2015; 293:41-5. [DOI: 10.1016/j.bbr.2015.06.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 06/24/2015] [Accepted: 06/28/2015] [Indexed: 01/08/2023]
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Şen LS, Karakoyun B, Yeğen C, Akkiprik M, Yüksel M, Ercan F, Özer A, Yeğen BÇ. Treatment with either obestatin or ghrelin attenuates mesenteric ischemia-reperfusion-induced oxidative injury of the ileum and the remote organ lung. Peptides 2015; 71:8-19. [PMID: 26032330 DOI: 10.1016/j.peptides.2015.04.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 04/06/2015] [Accepted: 04/14/2015] [Indexed: 12/14/2022]
Abstract
To evaluate the effects of exogenous ghrelin or obestatin on intestinal injury and accompanying pulmonary injury, intestinal ischemia-reperfusion (I/R) was induced in rats by obstructing the superior mesenteric artery for 60min, whereas laparotomy was performed in the sham group. At the beginning of the 90-min reperfusion period, the rats were injected with obestatin (100μg/kg), ghrelin (10ng/kg), or saline intravenously (iv). At the end of reperfusion, the blood, ileum, and lung samples were taken for the histological and biochemical assays. In the saline-treated I/R group, the increased serum interleukin (IL)-1β level, high damage scores, and elevated tissue malondialdehyde level and collagen content in both tissues were significantly reduced by obestatin or ghrelin. Increased ileal myeloperoxidase activity of the saline-treated I/R group was reduced by treatment with obestatin or ghrelin, whereas increased pulmonary myeloperoxidase activity was reduced with administration of obestatin. Increased DNA fragmentation in the ileum of the saline-treated I/R group was reduced by both peptides. Elevated luminol-lucigenin chemiluminescence levels and nuclear factor kappa B (NF-κB) messenger RNA (mRNA) expression in the ileum of the saline-treated-I/R group were significantly decreased by obestatin or ghrelin treatment. I/R-induced depletion of the antioxidant glutathione in both ileal and pulmonary tissues was prevented with either obestatin or ghrelin treatment. Administration of either obestatin or ghrelin exerts similar protective effects against I/R-induced ileal and pulmonary injury, thus warranting further investigation for their possible use against ischemic intestinal injury.
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Affiliation(s)
- Leyla Semiha Şen
- Marmara University School of Medicine, Department of General Surgery, Istanbul, Turkey
| | - Berna Karakoyun
- Marmara University Faculty of Health Sciences, Department of Basic Health Sciences, Istanbul, Turkey
| | - Cumhur Yeğen
- Marmara University School of Medicine, Department of General Surgery, Istanbul, Turkey
| | - Mustafa Akkiprik
- Marmara University School of Medicine, Department of Medical Biology, Istanbul, Turkey
| | - Meral Yüksel
- Marmara University Vocational School of Health Related Professions, Department of Medical Laboratory, Istanbul, Turkey
| | - Feriha Ercan
- Marmara University School of Medicine, Department of Histology and Embryology, Istanbul, Turkey
| | - Ayşe Özer
- Marmara University School of Medicine, Department of Medical Biology, Istanbul, Turkey
| | - Berrak Ç Yeğen
- Marmara University School of Medicine, Department of Physiology, Istanbul, Turkey.
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15
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Al Massadi O, López M, Fernø J, Diéguez C, Nogueiras R. What is the real relevance of endogenous ghrelin? Peptides 2015; 70:1-6. [PMID: 26003396 DOI: 10.1016/j.peptides.2015.04.027] [Citation(s) in RCA: 12] [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: 01/21/2015] [Revised: 04/06/2015] [Accepted: 04/07/2015] [Indexed: 12/11/2022]
Abstract
Ghrelin is a pleiotropic and ubiquitous gastric hormone implicated in body physiology. Ghrelin exhibits potent orexigenic actions and increases body weight and adiposity. Ghrelin is also involved in other metabolic functions among which we can highlight the GH releasing activity and the regulation of glucose homeostasis. Ghrelin needs the enzyme GOAT to be acylated, a step essential for binding to the GHSR1a receptor to exert its functions. Genetic animal models emerge as important tools to delineate the physiological relevance of ghrelin on energy balance. Despite the numerous reports using different genetically engineered mouse models targeting the ghrelin system, its endogenous relevance in metabolism seems to be less important than its pharmaceutical options.
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Affiliation(s)
- Omar Al Massadi
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), University of Santiago de Compostela, Avda. Barcelona s/n, 15782 Santiago de Compostela, Spain; CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Santiago de Compostela (A Coruña) 15706, Spain.
| | - Miguel López
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), University of Santiago de Compostela, Avda. Barcelona s/n, 15782 Santiago de Compostela, Spain; CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Santiago de Compostela (A Coruña) 15706, Spain
| | - Johan Fernø
- Department of Clinical Science, K. G. Jebsen Center for Diabetes Research, University of Bergen, Bergen N-5020, Norway
| | - Carlos Diéguez
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), University of Santiago de Compostela, Avda. Barcelona s/n, 15782 Santiago de Compostela, Spain; CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Santiago de Compostela (A Coruña) 15706, Spain
| | - Rubén Nogueiras
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), University of Santiago de Compostela, Avda. Barcelona s/n, 15782 Santiago de Compostela, Spain; CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Santiago de Compostela (A Coruña) 15706, Spain.
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16
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Gut satiety hormones and hyperemesis gravidarum. Arch Gynecol Obstet 2015; 292:1225-30. [DOI: 10.1007/s00404-015-3751-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 05/11/2015] [Indexed: 10/23/2022]
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17
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Yuan X, Cai W, Liang XF, Su H, Yuan Y, Li A, Tao YX. Obestatin partially suppresses ghrelin stimulation of appetite in "high-responders" grass carp, Ctenopharyngodon idellus. Comp Biochem Physiol A Mol Integr Physiol 2015; 184:144-9. [PMID: 25737031 DOI: 10.1016/j.cbpa.2015.02.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/01/2015] [Accepted: 02/23/2015] [Indexed: 12/17/2022]
Abstract
Ghrelin and obestatin are two gastrointestinal peptides obtained by post-translational processing of a common precursor, preproghrelin. The effect of obestatin on food intake is still controversial. The aim of the present study was to investigate the effects of ghrelin and obestatin on food intake in grass carp, Ctenopharyngodon idellus. Fish received intraperitoneal (IP) injection of saline, ghrelin (100 ng g(-1)BW), obestatin-like (25 ng g(-1)BW) and ghrelin in combination with obestatin-like. Ghrelin stimulation of food intake varied considerably among individual fish with 70.8% eliciting a robust response. In these high-responders, food intake was significantly increased by IP ghrelin within 2 h. Co-administration of ghrelin and obestatin-like resulted in a decrease in food intake, indicating that obestatin was able to antagonize the effect of ghrelin. However, IP obestatin-like alone could not regulate food intake in grass carp. RT-PCR analysis demonstrated that IP ghrelin peptide led to a significant increase in mRNA abundance of NPY, Y8a and Y8b genes compared to saline injected fish, while in combination with obestatin-like peptide decreased ghrelin-induced gene expressions of these three genes. IP sole obestatin-like peptide did not modify the expression levels of NPY, Y8a, Y8b, CART and POMC compared to the control group. Therefore, IP administration of obestatin-like peptide, partially blocking the ghrelin-induced appetite, investigated the possible involvement of obestatin as a mediator of the ghrelin stimulatory action on food intake, at least in "high-responders" grass carp.
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Affiliation(s)
- Xiaochen Yuan
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China
| | - Wenjing Cai
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China
| | - Xu-Fang Liang
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China.
| | - Hang Su
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China
| | - Yongchao Yuan
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China.
| | - Aixuan Li
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China
| | - Ya-Xiong Tao
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, Hubei 430070, China
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18
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Borges N, Moraes C, Barros AF, Carraro-Eduardo JC, Fouque D, Mafra D. Acyl-Ghrelin and Obestatin Plasma Levels in Different Stages of Chronic Kidney Disease. J Ren Nutr 2014; 24:100-4. [DOI: 10.1053/j.jrn.2013.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/03/2013] [Accepted: 11/26/2013] [Indexed: 11/11/2022] Open
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19
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20
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Boehm M, Hepworth D, Loria PM, Norquay LD, Filipski KJ, Chin JE, Cameron KO, Brenner M, Bonnette P, Cabral S, Conn E, Ebner DC, Gautreau D, Hadcock J, Lee ECY, Mathiowetz AM, Morin M, Rogers L, Smith A, VanVolkenburg M, Carpino PA. Chemical Probe Identification Platform for Orphan GPCRs Using Focused Compound Screening: GPR39 as a Case Example. ACS Med Chem Lett 2013; 4:1079-84. [PMID: 24900608 DOI: 10.1021/ml400275z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/16/2013] [Indexed: 12/20/2022] Open
Abstract
Orphan G protein-coupled receptors (oGPCRs) are a class of integral membrane proteins for which endogenous ligands or transmitters have not yet been discovered. Transgenic animal technologies have uncovered potential roles for many of these oGPCRs, providing new targets for the treatment of various diseases. Understanding signaling pathways of oGPCRs and validating these receptors as potential drug targets requires the identification of chemical probe compounds to be used in place of endogenous ligands to interrogate these receptors. A novel chemical probe identification platform was created in which GPCR-focused libraries were screened against sets of oGPCR targets, with a goal of discovering fit-for-purpose chemical probes for the more druggable members of the set. Application of the platform to a set of oGPCRs resulted in the discovery of the first reported small molecule agonists for GPR39, a receptor implicated in the regulation of insulin secretion and preservation of beta cells in the pancreas. Compound 1 stimulated intracellular calcium mobilization in recombinant and native cells in a GPR39-specific manner but did not potentiate glucose-stimulated insulin secretion in human islet preparations.
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Affiliation(s)
| | | | - Paula M. Loria
- Department
of Pharmacokinetics, Dynamics and Metabolism−New Chemical Entities, Primary Pharmacology Group, Pfizer Worldwide Research and Development, Eastern
Point Road, Groton, Connecticut 06340, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Lucy Rogers
- Department
of Pharmacokinetics, Dynamics and Metabolism−New Chemical Entities, Primary Pharmacology Group, Pfizer Worldwide Research and Development, Eastern
Point Road, Groton, Connecticut 06340, United States
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21
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Kaiya H, Kangawa K, Miyazato M. Update on ghrelin biology in birds. Gen Comp Endocrinol 2013; 190:170-5. [PMID: 23631903 DOI: 10.1016/j.ygcen.2013.04.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 04/01/2013] [Accepted: 04/04/2013] [Indexed: 12/21/2022]
Abstract
Ghrelin is a peptide found in the mucosal layer of the rat stomach that exhibits growth hormone-releasing and appetite-stimulating activities. Since the discovery of ghrelin in chicken in 2002, information on its structure, distribution, function, and receptors has been accumulated, mainly in poultry. Here, we summarize the following findings since 2008 in birds: (1) central ghrelin acts as an anorexigenic neuropeptide, but the effect of peripheral ghrelin differs depending on the chicken strain and light conditions the birds are kept in; (2) central ghrelin inhibits not only food intake but also water drinking, and it may be mediated by urocortin, a member of the corticotropin-releasing factor family; (3) peripheral ghrelin acts as an anti-lipogenic factor in broiler chickens but not in rats; (4) the enzyme involved in ghrelin acylation (ghrelin-O-acyltransferase [GOAT]) has been identified in chickens; (5) dietary lipids are used for ghrelin acylation; (6) des-acyl ghrelin administered alone or with ghrelin does not affect feeding behavior; (7) the existence and physiological function of obestatin must now be carefully examined in birds; (8) other than the growth hormone secretagogue receptors (GHS) R1a and 1b, GHS-R variants not found in mammals have been found in chicken and Japanese quail; and finally (9) little is known about the involvement of the ghrelin system in wild birds and in avian-specific behavior such as brooding and migration.
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Affiliation(s)
- Hiroyuki Kaiya
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
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22
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Erşahin M, Özsavcı D, Şener A, Özakpınar ÖB, Toklu HZ, Akakin D, Şener G, Yeğen BÇ. Obestatin alleviates subarachnoid haemorrhage-induced oxidative injury in rats via its anti-apoptotic and antioxidant effects. Brain Inj 2013; 27:1181-9. [PMID: 23895491 DOI: 10.3109/02699052.2013.804199] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Mehmet Erşahin
- School of Medicine, Department of Neurosurgery, Istanbul Medeniyet University
İstanbulTurkey
| | | | - Azize Şener
- School of Pharmacy, Department of Biochemistry
| | | | | | - Dilek Akakin
- School of Medicine, Department of Histology & Embryology
| | | | - Berrak Ç. Yeğen
- School of Medicine, Department of Physiology, Marmara University
IstanbulTurkey
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23
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Adipocytokines in thyroid dysfunction. ISRN INFLAMMATION 2013; 2013:646271. [PMID: 24049662 PMCID: PMC3765747 DOI: 10.1155/2013/646271] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 06/03/2013] [Indexed: 12/11/2022]
Abstract
Adipocytokines are important mediators of interorgan crosstalk in metabolic regulation. Thyroid diseases have effects on metabolism and inflammation. The mechanism of these effects is not clear. Recently, there are several reports suggesting this interrelation between adipocytokines and thyroid dysfunction. In this review, we summarize this relation according to the literature.
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24
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Monteleone P, Maj M. Dysfunctions of leptin, ghrelin, BDNF and endocannabinoids in eating disorders: beyond the homeostatic control of food intake. Psychoneuroendocrinology 2013; 38:312-30. [PMID: 23313276 DOI: 10.1016/j.psyneuen.2012.10.021] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/29/2012] [Accepted: 10/29/2012] [Indexed: 12/18/2022]
Abstract
A large body of literature documents the occurrence of alterations in the physiology of both central and peripheral modulators of appetite in acute patients with anorexia nervosa (AN) and bulimia nervosa (BN). Until more recently the role of most of the appetite modulators in the control of eating behavior was conceptualized solely in terms of their influence on homeostatic control of energy balance. However, it is becoming more and more evident that appetite modulators also affect the non-homeostatic cognitive, emotional and rewarding component of food intake as well as non food-related reward, and, recently, AN and BN have been pathophysiologically linked to dysfunctions of reward mechanisms. Therefore, the possibility exists that observed changes in appetite modulators in acute AN and BN may represent not only homeostatic adaptations to malnutrition, but also contribute to the development and/or the maintenance of aberrant non-homeostatic behaviors, such as self-starvation and binge eating. In the present review, the evidences supporting a role of leptin, ghrelin, brain-derived neurotrophic factor and endocannabinoids in the homeostatic and non-homeostatic dysregulations of patients with AN and BN will be presented. The reviewed literature is highly suggestive that changes in the physiology of these modulators may play a pivotal role in the pathophysiology of eating disorders by providing a possible link between motivated behaviors, reward processes, cognitive functions and energy balance.
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Affiliation(s)
- Palmiero Monteleone
- Department of Medicine and Surgery, University of Salerno, via S. Allende, 84084 Baronissi (Salerno), Italy.
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25
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Cheng HH, Kaiser P, Lamont SJ. Integrated Genomic Approaches to Enhance Genetic Resistance in Chickens. Annu Rev Anim Biosci 2013; 1:239-60. [DOI: 10.1146/annurev-animal-031412-103701] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hans H. Cheng
- Avian Disease and Oncology Laboratory, USDA, ARS, East Lansing, Michigan 48823;
| | - Pete Kaiser
- The Roslin Institute & Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom;
| | - Susan J. Lamont
- Department of Animal Science, Iowa State University, Ames, Iowa 50011;
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26
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Smitka K, Papezova H, Vondra K, Hill M, Hainer V, Nedvidkova J. The role of "mixed" orexigenic and anorexigenic signals and autoantibodies reacting with appetite-regulating neuropeptides and peptides of the adipose tissue-gut-brain axis: relevance to food intake and nutritional status in patients with anorexia nervosa and bulimia nervosa. Int J Endocrinol 2013; 2013:483145. [PMID: 24106499 PMCID: PMC3782835 DOI: 10.1155/2013/483145] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 07/11/2013] [Indexed: 12/13/2022] Open
Abstract
Eating disorders such as anorexia (AN) and bulimia nervosa (BN) are characterized by abnormal eating behavior. The essential aspect of AN is that the individual refuses to maintain a minimal normal body weight. The main features of BN are binge eating and inappropriate compensatory methods to prevent weight gain. The gut-brain-adipose tissue (AT) peptides and neutralizing autoantibodies play an important role in the regulation of eating behavior and growth hormone release. The mechanisms for controlling food intake involve an interplay between gut, brain, and AT. Parasympathetic, sympathetic, and serotoninergic systems are required for communication between brain satiety centre, gut, and AT. These neuronal circuits include neuropeptides ghrelin, neuropeptide Y (NPY), peptide YY (PYY), cholecystokinin (CCK), leptin, putative anorexigen obestatin, monoamines dopamine, norepinephrine (NE), serotonin, and neutralizing autoantibodies. This extensive and detailed report reviews data that demonstrate that hunger-satiety signals play an important role in the pathogenesis of eating disorders. Neuroendocrine dysregulations of the AT-gut-brain axis peptides and neutralizing autoantibodies may result in AN and BN. The circulating autoantibodies can be purified and used as pharmacological tools in AN and BN. Further research is required to investigate the orexigenic/anorexigenic synthetic analogs and monoclonal antibodies for potential treatment of eating disorders in clinical practice.
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Affiliation(s)
- Kvido Smitka
- Institute of Endocrinology, Laboratory of Clinical and Experimental Neuroendocrinology, Narodni 8, 116 94 Prague 1, Czech Republic
| | - Hana Papezova
- Psychiatric Clinic, First Faculty of Medicine, Charles University, Ke Karlovu 11, 121 08 Prague 2, Czech Republic
| | - Karel Vondra
- Institute of Endocrinology, Laboratory of Clinical and Experimental Neuroendocrinology, Narodni 8, 116 94 Prague 1, Czech Republic
| | - Martin Hill
- Institute of Endocrinology, Laboratory of Clinical and Experimental Neuroendocrinology, Narodni 8, 116 94 Prague 1, Czech Republic
| | - Vojtech Hainer
- Institute of Endocrinology, Laboratory of Clinical and Experimental Neuroendocrinology, Narodni 8, 116 94 Prague 1, Czech Republic
| | - Jara Nedvidkova
- Institute of Endocrinology, Laboratory of Clinical and Experimental Neuroendocrinology, Narodni 8, 116 94 Prague 1, Czech Republic
- *Jara Nedvidkova:
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27
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Méquinion M, Langlet F, Zgheib S, Dickson S, Dehouck B, Chauveau C, Viltart O. Ghrelin: central and peripheral implications in anorexia nervosa. Front Endocrinol (Lausanne) 2013; 4:15. [PMID: 23549309 PMCID: PMC3581855 DOI: 10.3389/fendo.2013.00015] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 02/01/2013] [Indexed: 11/15/2022] Open
Abstract
Increasing clinical and therapeutic interest in the neurobiology of eating disorders reflects their dramatic impact on health. Chronic food restriction resulting in severe weight loss is a major symptom described in restrictive anorexia nervosa (AN) patients, and they also suffer from metabolic disturbances, infertility, osteopenia, and osteoporosis. Restrictive AN, mostly observed in young women, is the third largest cause of chronic illness in teenagers of industrialized countries. From a neurobiological perspective, AN-linked behaviors can be considered an adaptation that permits the endurance of reduced energy supply, involving central and/or peripheral reprograming. The severe weight loss observed in AN patients is accompanied by significant changes in hormones involved in energy balance, feeding behavior, and bone formation, all of which can be replicated in animals models. Increasing evidence suggests that AN could be an addictive behavior disorder, potentially linking defects in the reward mechanism with suppressed food intake, heightened physical activity, and mood disorder. Surprisingly, the plasma levels of ghrelin, an orexigenic hormone that drives food-motivated behavior, are increased. This increase in plasma ghrelin levels seems paradoxical in light of the restrained eating adopted by AN patients, and may rather result from an adaptation to the disease. The aim of this review is to describe the role played by ghrelin in AN focusing on its central vs. peripheral actions. In AN patients and in rodent AN models, chronic food restriction induces profound alterations in the « ghrelin » signaling that leads to the development of inappropriate behaviors like hyperactivity or addiction to food starvation and therefore a greater depletion in energy reserves. The question of a transient insensitivity to ghrelin and/or a potential metabolic reprograming is discussed in regard of new clinical treatments currently investigated.
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Affiliation(s)
- Mathieu Méquinion
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
| | - Fanny Langlet
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
| | - Sara Zgheib
- Pathophysiology of inflammatory of bone diseases, Université Lille Nord de France-ULCO – Lille 2Boulogne sur Mer, France
| | - Suzanne Dickson
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
- Department of Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Bénédicte Dehouck
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
- Université Lille Nord de France – Université d’ArtoisLiévin, France
| | - Christophe Chauveau
- Pathophysiology of inflammatory of bone diseases, Université Lille Nord de France-ULCO – Lille 2Boulogne sur Mer, France
| | - Odile Viltart
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
- Université Lille Nord de France-USTL (Lille 1)Villeneuve d’Ascq, France
- *Correspondence: Odile Viltart, Development and Plasticity of the Postnatal Brain, Team 2, Jean-Pierre Aubert Research Center, UMR INSERM 837, Bât Biserte, 1 place de Verdun, 59,045 Lille cedex, France. e-mail:
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28
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Zhang JV, Li L, Huang Q, Ren PG. Obestatin receptor in energy homeostasis and obesity pathogenesis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:89-107. [PMID: 23317783 DOI: 10.1016/b978-0-12-386933-3.00003-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Based on the bioinformatic prediction, Zhang and colleagues discovered obestatin, a new 23-amino acid hormone from rat stomach extract encoded by the ghrelin gene. Obestatin is present not only in the gastrointestinal tract, but also in the spleen, mammary gland, breast milk, and plasma. Obestatin appears to function as part of a complex gut-brain network whereby hormones and substances from the stomach, intestine and the brain about satiety or hunger. Given the current research regarding the effects of obestatin and its possible cognate receptor(s), this chapter provides the latest review of the physiological and pathological characteristics of this hormone and its possible receptor(s) in energy homeostasis and obesity.
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Affiliation(s)
- Jian V Zhang
- Research Center for Gene and Cell Engineering, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advance Technology, Chinese Academy of Sciences, Shenzhen, China
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29
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Civelli O, Reinscheid RK, Zhang Y, Wang Z, Fredriksson R, Schiöth HB. G protein-coupled receptor deorphanizations. Annu Rev Pharmacol Toxicol 2012; 53:127-46. [PMID: 23020293 PMCID: PMC5828024 DOI: 10.1146/annurev-pharmtox-010611-134548] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
G protein-coupled receptors (GPCRs) are major regulators of intercellular interactions. They initiate these actions by being activated by a wide variety of natural ligands. Historically, ligands were discovered first, but the advent of molecular biology reversed this trend. Most GPCRs are identified on the basis of their DNA sequences and thus are initially unmatched to known natural ligands. They are termed orphan GPCRs. Discovering their ligands-i.e., "deorphanizing" the GPCRs-gave birth to the field of reverse pharmacology. This review discusses the present status of GPCR deorphanization, presents a few examples of successes and surprises, and highlights difficulties encountered in these efforts.
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Affiliation(s)
- Olivier Civelli
- Department of Pharmacology, University of California, Irvine, Irvine, California 92617, USA.
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Stengel A, Taché Y. Yin and Yang - the Gastric X/A-like Cell as Possible Dual Regulator of Food Intake. J Neurogastroenterol Motil 2012; 18:138-49. [PMID: 22523723 PMCID: PMC3325299 DOI: 10.5056/jnm.2012.18.2.138] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 03/11/2012] [Indexed: 01/14/2023] Open
Abstract
Ingestion of food affects secretion of hormones from enteroendocrine cells located in the gastrointestinal mucosa. These hormones are involved in the regulation of various gastrointestinal functions including the control of food intake. One cell in the stomach, the X/A-like has received much attention over the past years due to the production of ghrelin. Until now, ghrelin is the only known orexigenic hormone that is peripherally produced and centrally acting to stimulate food intake. Subsequently, additional peptide products of this cell have been described including desacyl ghrelin, obestatin and nesfatin-1. Desacyl ghrelin seems to be involved in the regulation of food intake as well and could play a counter-balancing role of ghrelin's orexigenic effect. In contrast, the initially proposed anorexigenic action of obestatin did not hold true and therefore the involvement of this peptide in the regulation of feeding is questionable. Lastly, the identification of nesfatin-1 in the same cell in different vesicles than ghrelin extended the function of this cell type to the inhibition of feeding. Therefore, this X/A-like cell could play a unique role by encompassing yin and yang properties to mediate not only hunger but also satiety.
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Affiliation(s)
- Andreas Stengel
- Department of Medicine, Division Psychosomatic Medicine and Psychotherapy, Charité, Campus Mitte, Universitätsmedizin Berlin, Berlin, Germany
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Zizzari P, Hassouna R, Grouselle D, Epelbaum J, Tolle V. Physiological roles of preproghrelin-derived peptides in GH secretion and feeding. Peptides 2011; 32:2274-82. [PMID: 21530598 DOI: 10.1016/j.peptides.2011.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 04/04/2011] [Accepted: 04/07/2011] [Indexed: 12/26/2022]
Abstract
Among the factors playing a crucial role in the regulation of energy metabolism, gastro-intestinal peptides are essential signals to maintain energy homeostasis as they relay to the central nervous system the informations about the nutritional status of the body. Among these factors, preproghrelin is a unique prohormone as it encodes ghrelin, a powerful GH secretagogue and the only orexigenic signal from the gastrointestinal tract and obestatin, a proposed functional ghrelin antagonist. These preproghrelin-derived peptides may contribute to balance energy intake, metabolism and body composition by regulating the activity of the GH/IGF-1 axis and appetite. Whereas the contribution of ghrelin has been well characterized, the role of the more recently identified obestatin, in this regulatory process is still controversial. In this chapter, we describe the contribution of these different preproghrelin-derived peptides and their receptors in the regulation of GH secretion and feeding. Data obtained from pharmacological approaches, mutant models and evaluation of the hormones in animal and human models are discussed.
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Affiliation(s)
- Philippe Zizzari
- UMR894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, 2 ter rue d'Alésia, 75014 Paris, France
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Abstract
Obesity has increased alarmingly in the United States and is increasing in many countries of the world. Because obesity is an important risk factor for type 2 diabetes and other chronic diseases, it is important to develop approaches to counter the rapid increase in adiposity. One approach is bariatric surgery, the most successful clinical intervention known for treating obesity. Surgery can result in impressive weight loss and improvement of obesity-related comorbidities. Yet the mechanisms responsible for this remarkable effect of surgery remain controversial. It is now clear that caloric restriction, per se, does not explain all the reduction in stored fat mass after surgery. A number of gastrointestinal hormones, including glucagon-like peptide (GLP)-1, peptide YY, oxyntomodulin, GLP-2, glucose-dependent insulinotropic polypeptide, ghrelin, and others, can play roles in energy homeostasis and could be involved in bariatric-surgery-related weight loss and weight loss maintenance. Vagal innervation may play a role. In addition, there may be other yet-uncharacterized factors that could participate. This review discusses the possible roles of these hormonal mechanisms in various types of bariatric surgery to help elucidate some of the potential mechanisms at play in short-term and long-term post-bariatric surgery weight loss. Understanding such mechanisms could lead to new and efficacious means to control or even reduce the epidemic of obesity.
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Affiliation(s)
- Viorica Ionut
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
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Genetic selection for body weight in chickens has altered responses of the brain's AMPK system to food intake regulation effect of ghrelin, but not obestatin. Behav Brain Res 2011; 221:216-26. [DOI: 10.1016/j.bbr.2011.02.034] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 02/22/2011] [Accepted: 02/24/2011] [Indexed: 12/21/2022]
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Jeffery P, McDonald V, Tippett E, McGuckin M. Ghrelin in gastrointestinal disease. Mol Cell Endocrinol 2011; 340:35-43. [PMID: 21458525 DOI: 10.1016/j.mce.2011.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 03/04/2011] [Indexed: 12/11/2022]
Abstract
Enteroendocrine cells of the gastric fundus are the predominant source of ghrelin production, although ghrelin gene transcripts and ghrelin-producing cells have been identified throughout the gastrointestinal tract. Various infectious, inflammatory and malignant disorders of the gastrointestinal system have been shown to alter ghrelin production and secretion and consequently to affect endocrine ghrelin levels and activity. Animal studies have demonstrated that ghrelin and synthetic ghrelin mimetics can reduce the severity of gastric and colonic inflammation and human clinical trials are underway to determine the efficacy of ghrelin in improving motility disorders. This review summarises the impact of gastrointestinal disease on ghrelin synthesis and secretion and the potential use of ghrelin and its mimetics for the treatment of these diseases.
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Affiliation(s)
- Penny Jeffery
- Mater Medical Research Institute, Mater Health Services, South Brisbane, Queensland 4101, Australia.
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Kowalska I, Karczewska-Kupczewska M, Strączkowski M. Adipocytokines, gut hormones and growth factors in anorexia nervosa. Clin Chim Acta 2011; 412:1702-11. [PMID: 21699889 DOI: 10.1016/j.cca.2011.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 06/02/2011] [Accepted: 06/06/2011] [Indexed: 12/25/2022]
Abstract
Anorexia nervosa is a complex eating disorder of unknown etiology which affects adolescent girls and young women and leads to chronic malnutrition. Clinical manifestations of prolonged semistarvation include a variety of physical features and psychiatric disorders. The study of different biological factors involved in the pathophysiology of anorexia nervosa is an area of active interest. In this review we have described the role of adipocytokines, neurotrophins, peptides of the gastrointestinal system and growth factors in appetite regulation, energy balance and insulin sensitivity in anorexia nervosa patients.
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Affiliation(s)
- Irina Kowalska
- Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Białystok, Poland.
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Verhulst PJ, Lintermans A, Janssen S, Loeckx D, Himmelreich U, Buyse J, Tack J, Depoortere I. GPR39, a receptor of the ghrelin receptor family, plays a role in the regulation of glucose homeostasis in a mouse model of early onset diet-induced obesity. J Neuroendocrinol 2011; 23:490-500. [PMID: 21470317 DOI: 10.1111/j.1365-2826.2011.02132.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
GPR39, which may function as a Zn(2+) sensor, is a member of the G protein-coupled receptor family that also includes the receptor for the hunger hormone ghrelin. The down-regulation of GPR39 mRNA in adipose tissue of obese type 2 diabetic patients suggests that GPR39 may contribute to the pathogenesis of the disease. The present study aimed to investigate the role of GPR39 in the regulation of energy balance and glucose homeostasis in wild-type (GPR39(+/+) ) and GPR39 knockout mice (GPR39(-/-) ) with obesity-related type 2 diabetes. GPR39 mRNA levels in adipose tissue of fasted GPR39(+/+) mice fed a high-fat diet (HFD) for 30 weeks were reduced and correlated positively with blood glucose levels. Body weight, fat percentage and energy intake were increased in the HFD group but did not differ between both genotypes. Within the HFD group, blood glucose levels were lower in GPR39(-/-) than in GPR39(+/+) mice, despite significant reductions in prandial plasma insulin levels. The latter may not be a result of changes in β-cell hyperplasia because immunohistochemical staining of pancreata of mice on a HFD showed no differences between genotypes. The lower blood glucose levels may involve alterations in insulin sensitivity as revealed by glucose tolerance tests and respiratory quotient measurements that showed a preference of obese GPR39(-/-) mice for the use of carbohydrates as metabolic fuel. The increase in plasma ghrelin levels in GPR39(-/-) mice fed a HFD may contribute to the alterations in glucose homeostasis, whereas changes in gastric emptying or intestinal Zn(2+) absorption are not involved. The results obtained in the present study suggest that GPR39 plays a role in the pathogenesis of obesity-related type 2 diabetes by affecting the regulation of glucose homeostasis.
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MESH Headings
- Age of Onset
- Animals
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diet/adverse effects
- Diet, Atherogenic
- Disease Models, Animal
- Genetic Predisposition to Disease
- Glucose/metabolism
- Homeostasis/genetics
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Multigene Family/physiology
- Obesity/epidemiology
- Obesity/etiology
- Obesity/genetics
- Obesity/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Receptors, Ghrelin/genetics
- Receptors, Ghrelin/physiology
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Affiliation(s)
- P J Verhulst
- Department of Pathophysiology, Translational Research Center for Gastrointestinal Disorders, Catholic University of Leuven, Leuven, Belgium
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Abstract
Ghrelin is a unique endogenous peptidic hormone regulating both hunger and adiposity. Many of the actions of ghrelin are modulated specifically by the central nervous system. A number of molecular events triggered via the activation of the ghrelin receptor (GHS-R1a), leading to increased levels of neuropeptide Y (NPY) and agoutirelated peptide (AgRP) and ultimately responsible for the orexigenic effect of ghrelin have been characterized. Moreover, the discovery of ghrelin O-acyltransferase (GOAT), the enzyme responsible for the octanoylation of ghrelin, provides a mechanism allowing specific targeting of the ghrelin/GHS-R1a system without affecting the role of des-acyl-ghrelin in other pathways involved in the regulation of energy balance. This review aims to summarize novel roles of ghrelin in energy balance, focusing particularly on both the newly identified neuronal pathways mediating the effects of ghrelin and on peripheral mechanisms leading to increased adiposity.
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Affiliation(s)
- Ruben Nogueiras
- Department of Physiology, University of Santiago de Compostela, Santiago de Compostela, Spain.
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Subasinghage AP, Green BD, Flatt PR, Irwin N, Hewage CM. Metabolic and structural properties of human obestatin {1-23} and two fragment peptides. Peptides 2010; 31:1697-705. [PMID: 20553778 DOI: 10.1016/j.peptides.2010.05.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 05/21/2010] [Accepted: 05/21/2010] [Indexed: 12/26/2022]
Abstract
Obestatin is a peptide produced in the oxyntic mucosa of the stomach and co-localizes with ghrelin on the periphery of pancreatic islets. Several studies demonstrate that obestatin reduces food and water intake, decreases body weight gain, inhibits gastrointestinal motility, and modulates glucose-induced insulin secretion. In this study we evaluated the acute metabolic effects of human obestatin {1-23} and fragment peptides {1-10} or {11-23} in high-fat fed mice, and then investigated their solution structure by NMR spectroscopy and molecular modelling. Obestatins {1-23} and {11-23} significantly reduced food intake (86% and 90% respectively) and lowered glucose responses to feeding, whilst leaving insulin responses unchanged. No metabolic changes could be detected following the administration of obestatin {1-10}. In aqueous solution none of the obestatin peptides possessed secondary structural features. However, in a 2,2,2-trifluoroethanol (TFE-d(3))-H(2)O solvent mixture, the structure of obestatin {1-23} was characterized by an alpha-helix followed by a single turn helix conformation between residues Pro(4) and Gln(15) and His(19) and Ala(22) respectively. Obestatin {1-10} showed no structural components whereas {11-23} contained an alpha-helix between residues Val(14) and Ser(20) in a mixed solvent. These studies are the first to elucidate the structure of human obestatin and provide clear evidence that the observed alpha-helical structures are critical for in vivo activity. Future structure/function studies may facilitate the design of novel therapeutic agents based on the obestatin peptide structure.
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Affiliation(s)
- Anusha P Subasinghage
- UCD School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, SEC Strategic Research Cluster, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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39
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Tissue distribution and effects of fasting and obesity on the ghrelin axis in mice. ACTA ACUST UNITED AC 2010; 163:62-73. [DOI: 10.1016/j.regpep.2010.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 03/05/2010] [Accepted: 03/22/2010] [Indexed: 11/21/2022]
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Abstract
The discovery of ghrelin has elucidated the role of the stomach as an important organ in the regulation of growth hormone release and energy homeostasis. Ghrelin is orexigenic; it is secreted from the stomach and circulates in the blood stream under fasting conditions, indicating that it transmits a hunger signal from the periphery to the central nervous system. Ghrelin is a peptide hormone, in which serine 3 (threonine 3 in frogs) is modified by an n-octanoic acid; this modification is essential for ghrelin's activity. Recently the enzymes responsible for the processing from the ghrelin precursor to active n-octanoyl-modified ghrelin have been identified. This review surveys the processing pathway from ghrelin gene to mature ghrelin peptide and summarizes our knowledge of the regulatory mechanism of ghrelin secretion and function.
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41
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Stengel A, Goebel M, Wang L, Taché Y. Ghrelin, des-acyl ghrelin and nesfatin-1 in gastric X/A-like cells: role as regulators of food intake and body weight. Peptides 2010; 31:357-69. [PMID: 19944123 PMCID: PMC3166546 DOI: 10.1016/j.peptides.2009.11.019] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 11/12/2009] [Accepted: 11/16/2009] [Indexed: 02/07/2023]
Abstract
Numerous peptides released from endocrine cells in the intestinal mucosa were established early on to be involved in the physiological regulation of food intake with a prominent role in termination of food ingestion when nutrients pass along the intestinal tract. Recently, peptides released from X/A-like endocrine cells of the gastric oxyntic mucosa were recognized as additional key players in the regulation of feeding and energy expenditure. Gastric X/A-like cells release the octanoylated peptide, ghrelin, the only known peripherally produced hormone stimulating food intake through interaction with growth hormone secretagogue 1a receptor (GHS-R1a). Additionally, non-octanoylated (des-acyl) ghrelin present in the circulation at higher levels than ghrelin is currently discussed as potential modulator of food intake by opposing ghrelin's action independent from GHS-R1a although the functional significance remains to be established. Obestatin, a ghrelin-associated peptide was initially reported as anorexigenic modulator of ghrelin's orexigenic action. However, subsequent reports did not support this contention. Interesting is the recent identification of nesfatin-1, a peptide derived from the nucleobindin2 gene prominently expressed in gastric X/A-like cells in different vesicles than ghrelin. Circulating nesfatin-1 levels vary with metabolic state and peripheral or central injection inhibits dark phase feeding in rodents. Overall, these data point to an important role of gastric X/A-like cells in food intake regulation through the expression of the orexigenic peptide ghrelin along with des-acyl ghrelin and nesfatin-1 capable of reducing food intake upon exogenous injection although their mechanisms of action and functional significance remain to be established.
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Affiliation(s)
- Andreas Stengel
- CURE: Digestive Diseases Research Center and Neurobiology of Stress, Digestive Diseases Division, David Geffen School of Medicine at University of California Los Angeles and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA.
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42
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Crespo MA, González Matías LC, Lozano MG, Paz SF, Pérez MR, Gago EV, Ferrer FM. [Gastrointestinal hormones in food intake control]. ACTA ACUST UNITED AC 2010; 56:317-30. [PMID: 19695513 DOI: 10.1016/s1575-0922(09)71946-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 05/25/2009] [Indexed: 12/17/2022]
Abstract
The discovery of gut hormones regulating the energy balance has aroused great interest in the scientific community. Some of these hormones modulate appetite and satiety, acting on the hypothalamus or the solitary tract nucleus in the brainstem. In general, the endocrine signals generated in the gut have direct or indirect (through the autonomous nervous system) anorexigenic effects. Only ghrelin, a gastric hormone, has been consistently associated with the initiation of food intake and is regarded as the main orexigenic signal both in animal models and humans. In this review, we provide a brief description of the major gastrointestinal hormones implicated in the regulation of food intake. Given the increased importance of food intake disturbances, especially obesity, a better understanding of the underlying mechanisms of action of the gastrointestinal hormones might contribute to the development of new molecules that could increase the therapeutic arsenal for treating obesity and its associated comorbidities.
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Affiliation(s)
- Mayte Alvarez Crespo
- Laboratorio de Endocrinología, Departamento de Biología Funcional y Ciencias de la Salud, Facultad de Biología, Universidad de Vigo, Vigo, Pontevedra, España
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Epelbaum J, Bedjaoui N, Dardennes R, Feng DD, Gardette R, Grouselle D, Loudes C, Simon A, Tolle V, Yang SK, Zizzari P. Role of the ghrelin/obestatin balance in the regulation of neuroendocrine circuits controlling body composition and energy homeostasis. Mol Cell Endocrinol 2010; 314:244-7. [PMID: 19733621 DOI: 10.1016/j.mce.2009.08.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 08/30/2009] [Indexed: 11/16/2022]
Abstract
Ghrelin and obestatin are two peptides isolated from the gastrointestinal tract and encoded by the same preproghrelin gene. They convey to the central nervous system informations concerning the nutritional status and/or the energy stores. Ghrelin, mostly acting through the GH secretagogue receptor GHS-R, is a potent GH secretagogue, an orexigenic peptide and a long-term regulator of energy homeostasis. Obestatin was initially described for its anorexigenic effects and its binding to the G protein-coupled receptor 39 (GPR39). However, the role of obestatin is still controversial and the nature of the obestatin receptor remains an open question. This review is focussed on the possible implication of the ghrelin/obestatin system in psychiatric diseases with particular emphasis on eating disorders.
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Affiliation(s)
- Jacques Epelbaum
- Centre de Psychiatrie & Neurosciences, UMR 894 Inserm, Faculté de Médecine, Université Paris Descartes, Paris, France.
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Kukuvitis A, Froudarakis M, Tryfon S, Tzouvelekis A, Saroglou M, Karkavitsas N, Bouros D. Acute effect of smoking on plasma Obestatin levels. Tob Induc Dis 2010; 8:2. [PMID: 20148104 PMCID: PMC2819234 DOI: 10.1186/1617-9625-8-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 01/07/2010] [Indexed: 11/19/2022] Open
Abstract
Background Smoking and smoking cessation are considered to be associated with weight changes. We have recently shown that smoking acutely increases plasma levels of ghrelin, a known orexigenic hormone. Obestatin is a peptide encoded by the ghrelin gene, which opposes ghrelin effects on food intake. We conducted a study in adult volunteers measuring plasma levels of obestatin immediately after initiation of smoking. Methods 31 volunteers (mean age 32.2 ± 9.2 years and mean BMI 25.7 ± 4.1), 17 smokers and 14 non-smokers, were enrolled in our study. The 2 groups were matched in age and BMI. Plasma obestatin concentrations were determined at baseline (T0), 2 (T2), 5 (T5), 15 (T15), and 60 (T60) minutes after the initiation of smoking. Results In all 31 subjects, no significant difference in the mean values of plasma obestatin levels was observed from baseline at T2, T5, T15 and T60 after initiation of smoking (overall p = 0.15). However, a trend for higher obestatin levels was noted in smokers vs non-smokers (overall p = 0.069), which was not related to the pack-years. Conclusion On the contrary with ghrelin's response after smoking initiation, there is no such an acute response of plasma obestatin levels.
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Affiliation(s)
- Asterios Kukuvitis
- Department of Endocrinology, Medical School Democritus University of Thrace, Alexandroupolis, Greece
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45
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Abstract
Alterations of both central and peripheral feeding regulatory substances occur in the acute phases of anorexia nervosa (AN) and bulimia nervosa (BN) and, generally, reverse after recovery. Some of these alterations are believed not only to sustain the altered eating behavior but also to contribute to certain psychopathological aspects and/or etiopathogenetic processes of eating disorders (EDs). It has been suggested that EDs are clinical conditions linked to reward-related mechanisms leading to a kind of addiction to self-starvation and/or overeating. Most of the feeding regulatory substances, which are dysregulated in EDs, are also implicated in the modulation of reward, emotional, and cognitive functions, thus representing possible links between altered nutritional regulation, motivated behaviors and reward processes. In this chapter, the ED literature dealing with ghrelin, brain-derived neurotrophic factor, opioid peptides, and endocannabinoids, which have prominent effects on eating behavior, body weight, reward, emotional, and cognitive functions, is reviewed in view of the above suggested links. Moreover, the potential therapeutics of new medications developed on the basis of neuroendocrine aberrations found in EDs is also presented.
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46
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Aygen B, Dogukan A, Dursun FE, Aydin S, Kilic N, Sahpaz F, Celiker H. Ghrelin and obestatin levels in end-stage renal disease. J Int Med Res 2009; 37:757-65. [PMID: 19589259 DOI: 10.1177/147323000903700319] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Malnutrition is fairly common in end-stage renal disease (ESRD) patients, persistent lack of appetite being a major symptom. Ghrelin and obestatin are two hormones that are involved in appetite and energy homeostasis. The present study examined ghrelin and obestatin levels in 24 ESRD patients undergoing haemodialysis and 24 age-matched healthy controls. Serum and saliva ghrelin and obestatin levels in the ESRD patients were significantly higher compared with controls, while saliva ghrelin and obestatin levels in all study participants were significantly higher than serum levels. Saliva ghrelin correlated with serum ghrelin and saliva obestatin correlated with serum obestatin in all study participants, although there was no correlation between ghrelin and obestatin levels. In conclusion, the results suggest that the kidneys may have a role in the metabolism and/or clearance of obestatin, as they do for ghrelin. Further studies are needed to determine if elevated levels of these hormones in ESRD patients contribute to the malnutrition that is common in these patients.
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Affiliation(s)
- B Aygen
- Department of Nephrology, Medical Faculty, Firat University, Elazig, Turkey.
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47
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Rucinski M, Ziolkowska A, Tyczewska M, Malendowicz LK. Expression of prepro-ghrelin and related receptor genes in the rat adrenal gland and evidences that ghrelin exerts a potent stimulating effect on corticosterone secretion by cultured rat adrenocortical cells. Peptides 2009; 30:1448-55. [PMID: 19416745 DOI: 10.1016/j.peptides.2009.04.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 04/24/2009] [Accepted: 04/25/2009] [Indexed: 11/30/2022]
Abstract
The orexigenic peptide ghrelin (GHREL) and obestatin (OBS) originate from the same peptide precursor, preproghrelin (ppGHREL). Apart from orexigenic effect, GHREL also regulates neuroendocrine function. We investigated GHREL and OBS effects on corticosterone secretion by freshly isolated and cultured rat adrenocortical cells. Classic RT-PCR revealed the presence of ppGHREL, GHS-R1a, GPR39v1 and GPR39v2 and GOAT4 (ghrelin O-acyl transferase) mRNAs in rat adrenals and cultured for 4 days rat adrenocortical cells. Expression of ppGHREL, GHS-R1a, and GOAT genes was notably higher in the cortex than in medulla. High expression level of GOAT gene was found in the zona glomerulosa, while expression level of both GPR39v1 and GPR39v2 genes was similar in adrenal cortical zones and in medulla. In freshly isolated cells neither GHREL nor OBS had an effect on corticosteroid output. Prolonged exposure of cultured cells to GHREL resulted in a potent, comparable to ACTH, stimulating effect of GHREL on corticosterone secretion. Prolonged exposure to OBS was ineffective. Neither GHREL nor OBS had any effect on proliferation of studied cells, while ACTH notably lowered it. GHREL down regulated GHS-R1a gene expression while both ACTH and GHREL stimulated expression level of GPR39v1 gene. Expression of CYP11A1 gene was notably stimulated and that of StAR gene remained unaffected by ACTH or GHREL. Thus, our study is the first to demonstrate direct stimulating effect of GHREL on corticosterone output by cultured rat adrenocortical cells. This stimulating action differs from that evoked by ACTH and is not dependent on the presence of functional ACTH receptor.
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Affiliation(s)
- Marcin Rucinski
- Department of Histology and Embryology, Medical University, 6 Swiecicki Street, 60-781 Poznan, Poland
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Volante M, Rosas R, Ceppi P, Rapa I, Cassoni P, Wiedenmann B, Settanni F, Granata R, Papotti M. Obestatin in human neuroendocrine tissues and tumours: expression and effect on tumour growth. J Pathol 2009; 218:458-66. [DOI: 10.1002/path.2551] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Annemie VD, Debby VD, Valentijn V, Bart DS, Walter L, Liliane S, Peter Paul DD. Central administration of obestatin fails to show inhibitory effects on food and water intake in mice. ACTA ACUST UNITED AC 2009; 156:77-82. [DOI: 10.1016/j.regpep.2009.04.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 04/06/2009] [Accepted: 04/29/2009] [Indexed: 11/29/2022]
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50
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Yamamoto I, Kimura N, Arai T, Tanaka M. cDNA cloning and mRNA expression of bovine GPR39. J Vet Med Sci 2009; 71:641-4. [PMID: 19498292 DOI: 10.1292/jvms.71.641] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
GPR39 is an orphan G protein-coupled receptor that is thought to be involved in gastrointestinal and metabolic function. In this study, we cloned bovine GPR39 cDNA that encoded 462 amino acids showing high sequence homology to other mammalian GPR39 proteins. Real-time PCR showed expression of GPR39 mRNA in the liver, kidney, abomasums, small intestine, colon, rectum and uterus, with the highest level in the abomasums. Significant promoter activity was observed within the -2.3 kb 5'-upstream region of bovine GPR39 gene with human colon carcinoma-derived CACO-2 cells. These findings suggest that GPR39 may have important roles in gastrointestinal and metabolic functions in bovines as in other mammals.
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Affiliation(s)
- Ichiro Yamamoto
- School of Veterinary Medicine, Nippon Veterinary and Life Science University, Japan
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