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Hill TG, Hill DJ. The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes. Int J Mol Sci 2024; 25:4070. [PMID: 38612880 PMCID: PMC11012451 DOI: 10.3390/ijms25074070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.
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Affiliation(s)
- Thomas G. Hill
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - David J. Hill
- Lawson Health Research Institute, St. Joseph’s Health Care, London, ON N6A 4V2, Canada;
- Departments of Medicine, Physiology and Pharmacology, Western University, London, ON N6A 3K7, Canada
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2
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Crucial Regulatory Role of Organokines in Relation to Metabolic Changes in Non-Diabetic Obesity. Metabolites 2023; 13:metabo13020270. [PMID: 36837889 PMCID: PMC9967669 DOI: 10.3390/metabo13020270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/09/2023] [Accepted: 02/12/2023] [Indexed: 02/16/2023] Open
Abstract
Obesity is characterized by an excessive accumulation of fat leading to a plethora of medical complications, including coronary artery disease, hypertension, type 2 diabetes mellitus or impaired glucose tolerance and dyslipidemia. Formerly, several physiological roles of organokines, including adipokines, hepatokines, myokines and gut hormones have been described in obesity, especially in the regulation of glucose and lipid metabolism, insulin sensitivity, oxidative stress, and low-grade inflammation. The canonical effect of these biologically active peptides and proteins may serve as an intermediate regulatory level that connects the central nervous system and the endocrine, autocrine, and paracrine actions of organs responsible for metabolic and inflammatory processes. Better understanding of the function of this delicately tuned network may provide an explanation for the wide range of obesity phenotypes with remarkable inter-individual differences regarding comorbidities and therapeutic responses. The aim of this review is to demonstrate the role of organokines in the lipid and glucose metabolism focusing on the obese non-diabetic subgroup. We also discuss the latest findings about sarcopenic obesity, which has recently become one of the most relevant metabolic disturbances in the aging population.
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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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Wargent ET. Measurement of Insulin Secretion Using Pancreas Perfusion in the Rodent. Methods Mol Biol 2020; 2076:281-297. [PMID: 31586335 DOI: 10.1007/978-1-4939-9882-1_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Under in vivo conditions, the study of physiological and pharmacological functions of an organ is difficult due to whole-body interactions with the organ. Thus, an in vitro technique for the perfusion of isolated pancreata was developed for physiologic and response studies including the investigation of endocrine function and secretory responsiveness under a variety of diabetes-associated conditions. The pancreas is isolated from the connecting spleen, stomach, and duodenum and transferred to a pre-warmed chamber where it is perfused in isolation from all other organs. A detailed description of the isolation of pancreata from rats and mice and the perfusion apparatus is described, as well as the measurement of glucose-stimulated insulin secretion using an in-house-developed radioimmunoassay.
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Affiliation(s)
- Edward T Wargent
- Buckingham Institute of Translational Medicine, University of Buckingham, Buckingham, UK.
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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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Rivera-Leon EA, Llamas-Covarrubias IM, Soria-Rodriguez RA, Sanchez-Enriquez S, González-Hernández LA, Andrade-Villanueva JF, Llamas-Covarrubias MA. Serum ghrelin and obestatin levels in HIV-infected patients: Effect of 36 weeks of antiretroviral treatment. ACTA ACUST UNITED AC 2018; 66:4-10. [PMID: 30316761 DOI: 10.1016/j.endinu.2018.05.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 05/22/2018] [Accepted: 05/30/2018] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Patients with HIV+ often present lipid disturbances. The role of ghrelin and obestatin in these lipid disturbances is not clear. The effect of antiretroviral (ART) drugs on those molecules is also unknown. This study measured ghrelin and obestatin levels, as well as metabolic markers, in patients with HIV+ before and after 36 weeks of ART. MATERIAL AND METHODS Twenty HIV-positive, ART-naïve patients who started a scheme consisting of tenofovir/emtricitabine+lopinavir/ritonavir were enrolled. Plasma samples were collected before and after 36 weeks of treatment. Serum ghrelin and obestatin levels were quantitated by ELISA; glucose, cholesterol, and triglyceride levels were measured by colorimetric and enzymatic methods, and cardiovascular risk was calculated by the atherogenic index of plasma (AIP). RESULTS All patients completed 36 weeks of ART. Total cholesterol (p<0.001), LDL-C (p=0.019), HDL-C (p=0.003), VLDL-C (p=0.002), and triglyceride levels (p=0.021) significantly increased after treatment. AIP revealed increased cardiovascular risk at baseline, which remained high after treatment. There was a statistically significant increase in obestatin level in the unpaired and paired analyses, while ghrelin levels only showed a trend to increase. Changes in ghrelin and obestatin levels positively correlated, but no correlation was seen with any metabolic parameter. CONCLUSION After 36 weeks of ART, patients showed an altered lipid profile, but there were no significant changes in cardiovascular risk. Ghrelin and obestatin levels increased after 36 weeks of ART, but the increase was only significant for obestatin. Changes in ghrelin and obestatin positively correlate.
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Affiliation(s)
- Edgar A Rivera-Leon
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Iris M Llamas-Covarrubias
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Raul A Soria-Rodriguez
- Instituto de Investigación en Inmunodeficiencias y VIH, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Sergio Sanchez-Enriquez
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Luz A González-Hernández
- Instituto de Investigación en Inmunodeficiencias y VIH, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Jaime F Andrade-Villanueva
- Instituto de Investigación en Inmunodeficiencias y VIH, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Mara A Llamas-Covarrubias
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico; Asociación Mexicana para el Fomento a Innovación, El Arenal, Jalisco, Mexico.
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Kapica M, Puzio I, Kato I, Kuwahara A, Zabielski R, Antushevich H. Exogenous obestatin affects pancreatic enzyme secretion in rat through two opposite mechanisms, direct inhibition and vagally-mediated stimulation. JOURNAL OF ANIMAL AND FEED SCIENCES 2018. [DOI: 10.22358/jafs/89734/2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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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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9
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Abstract
Ghrelin, an endoggenous for the growth hormone secretagogue receptor, has been shown to participate in the regulation of energy homeostasis and pituitary hormone secretion. Obestatin, encoded by the same gene as ghrelin, is described as a physiological opponent of ghrelin. Ghrelin and obestatin are altered in polycystic ovary syndrome (PCOS), which is characterized by insulin resistance and pituitary hormone secretion disorder. The aim of this study was to evaluate ghrelin/obestatin imbalance in relation to insulin resistance and pituitary hormone in adolescence with PCOS. This restrospective case-control study included 33 adolescence with PCOS and 38 control adolescence. Ghrelin and obestatin concentrations in serum were determined by RIA, and the serum fasting glucose and Insulin were determined by the glucose oxidase color method and INS-EASIA. The serum LH and FSH were measured by highly specific hemiluminescence immunoassays. We found that the serum ghrelin levels and ghrelin/obestatin ratio were significant lower in PCOS group than in control group, and the serum obestatin levels were significant higher in PCOS group than in control group. The ghrelin/obestatin ratios were negatively correlation with LH/FSH ratio and insulin resistant index in PCOS group. The findings of this study suggest that ghrelin/obestatin imbalance may play a role in pathogenesis of adolescent PCOS.
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Affiliation(s)
- Weiguang Wu
- a Department of Obstetrics and Gynecology , Affiliated Hospital, Logistical College of Chinese People's Armed Police Forces , Tianjin , PR China
| | - Xiaobin Fan
- b Department of Obstetrics and Gynecology , Xi'an No3 Hospital , Shanxi Xi'an , PR China
| | - Yuecheng Yu
- c Department of Obstetrics & Gynecology , Xijing Hospital, Fourth Military Medical University , Shanxi Xi'an , PR China
| | - Zheng Wang
- a Department of Obstetrics and Gynecology , Affiliated Hospital, Logistical College of Chinese People's Armed Police Forces , Tianjin , PR China
| | - Yingchun Wang
- a Department of Obstetrics and Gynecology , Affiliated Hospital, Logistical College of Chinese People's Armed Police Forces , Tianjin , PR China
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Kołodziejski PA, Pruszyńska-Oszmałek E, Strowski MZ, Nowak KW. Long-term obestatin treatment of mice type 2 diabetes increases insulin sensitivity and improves liver function. Endocrine 2017; 56:538-550. [PMID: 28477305 DOI: 10.1007/s12020-017-1309-2] [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: 11/23/2016] [Accepted: 04/19/2017] [Indexed: 01/02/2023]
Abstract
PURPOSE Obestatin and ghrelin are peptides encoded by the preproghrelin gene. Obestatin inhibits food intake, in addition to regulation of glucose and lipid metabolism. Here, we test the ability of obestatin at improving metabolic control and liver function in type 2 diabetic animals (type 2 diabetes mellitus). METHODS The effects of chronic obestatin treatment of mice with experimentally induced type 2 diabetes mellitus on serum levels of glucose and lipids, and insulin sensitivity are characterized. In addition, alterations of hepatic lipid and glycogen contents are evaluated. RESULTS Obestatin reduced body weight and decreased serum glucose, fructosamine, and β-hydroxybutyrate levels, as well as total and low-density lipoprotein fractions of cholesterol. In addition, obestatin increased high-density lipoproteins cholesterol levels and enhanced insulin sensitivity in mice with type 2 diabetes mellitus. Moreover, obestatin diminished liver mass, hepatic triglycerides and cholesterol contents, while glycogen content was higher in livers of healthy and mice with type 2 diabetes mellitus treated with obestatin. These changes were accompanied by reduction of increased alanine aminotransferase, aspartate aminotransferase, and gamma glutamyl transpeptidase in T2DM mice with type 2 diabetes mellitus. Obestatin increased adiponectin levels and reduced leptin concentration. Obestatin influenced the expression of genes involved in lipid and carbohydrate metabolism by increasing Fabp5 and decreasing G6pc, Pepck, Fgf21 mRNA in the liver. Obestatin increased both, AKT and AMPK phosphorylation, and sirtuin 1 (SIRT1) protein levels as well as mRNA expression in the liver. CONCLUSION Obestatin improves metabolic abnormalities in type 2 diabetes mellitus, restores hepatic lipid contents and decreases hepatic enzymes. Therefore, obestatin could potentially have a therapeutic relevance in treating of insulin resistance and metabolic dysfunctions in type 2 diabetes mellitus.
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Affiliation(s)
- Paweł A Kołodziejski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska Street 35, 60-637, Poznan, Poland.
| | - Ewa Pruszyńska-Oszmałek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska Street 35, 60-637, Poznan, Poland
| | - Mathias Z Strowski
- Department of Hepatology and Gastroenterology & the Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, 13353, Berlin, Germany
- Park-Klinik Weissensee, Internal Medicine - Gastroenterology, Berlin, 13086, Germany
| | - Krzysztof W Nowak
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska Street 35, 60-637, Poznan, Poland
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Pradhan G, Wu CS, Han Lee J, Kanikarla P, Guo S, Yechoor VK, Samson SL, Sun Y. Obestatin stimulates glucose-induced insulin secretion through ghrelin receptor GHS-R. Sci Rep 2017; 7:979. [PMID: 28428639 PMCID: PMC5430520 DOI: 10.1038/s41598-017-00888-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/07/2017] [Indexed: 11/19/2022] Open
Abstract
Orexigenic hormone ghrelin and anorexic hormone obestatin are encoded by the same preproghrelin gene. While it is known that ghrelin inhibits glucose-stimulated insulin secretion (GSIS), the effect of obestatin on GSIS is unclear. Ghrelin’s effect is mediated by its receptor Growth Hormone Secretagogue Receptor (GHS-R), but the physiologically relevant receptor of obestatin remains debatable. Here we have investigated the effect of obestatin on GSIS in vitro, in vivo and ex vivo, and tested whether obestatin regulates insulin secretion through GHS-R. We found that under hyperglycemic condition, obestatin augments GSIS in rat insulinoma cells (INS-1) and in pancreatic islets from ghrelin−/− mice. Surprisingly, obestatin-induced GSIS was absent in β-cells in which GHS-R was suppressed. Obestatin-induced insulin secretion was abolished in the circulation of Ghsr−/− mice, and in pancreatic islets isolated from Ghsr−/− mice. We also found that obestatin-induced GSIS was attenuated in islets isolated from β-cell-specific Ghsr knockout MIP-Cre/ERT;Ghsrf/f mice. Our data collectively demonstrate that obestatin is a potent insulin secretagogue under hyperglycemic condition, and obestatin’s effect on insulin secretion is mediated by GHS-R in pancreatic β-cells. Our findings reveal an intriguing insight that obestatin and ghrelin have opposing effects on insulin secretion, and both are mediated through ghrelin receptor GHS-R.
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Affiliation(s)
- Geetali Pradhan
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Chia-Shan Wu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Jong Han Lee
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,College of Pharmacy, Gachon University, Incheon, 21936, Korea
| | - Preeti Kanikarla
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Shaodong Guo
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Vijay K Yechoor
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Susan L Samson
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Yuxiang Sun
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA. .,Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 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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Xing YX, Yang L, Kuang HY, Gao XY, Liu HL. Function of obestatin in the digestive system. Nutrition 2017; 34:21-28. [DOI: 10.1016/j.nut.2016.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 04/18/2016] [Accepted: 08/29/2016] [Indexed: 02/07/2023]
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Wysokiński A. Obestatin may be involved in clozapine-induced changes in glucose metabolism. Schizophr Res 2016; 176:201-202. [PMID: 27427559 DOI: 10.1016/j.schres.2016.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 06/27/2016] [Accepted: 07/03/2016] [Indexed: 10/21/2022]
Affiliation(s)
- Adam Wysokiński
- Department of Old Age Psychiatry and Psychotic Disorders, Medical University of Lodz, Czechoslowacka 8/10, Lodz, Poland
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15
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Wang JL, Xu XH, Zhang XJ, Li WH. The role of obestatin in roux-en-Y gastric bypass-induced remission of type 2 diabetes mellitus. Diabetes Metab Res Rev 2016; 32:470-7. [PMID: 26445403 DOI: 10.1002/dmrr.2735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 08/31/2015] [Accepted: 10/04/2015] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a complex and multifactorial disease that is generally characterized by insulin resistance and loss of β-cell function that develops in adulthood. To date, more than 6% of the world's population is affected by T2DM. The main treatments of T2DM are dietary and lifestyle changes. However, only dependent on behaviour modification and oral hypoglycemics, many patients are unable to maintain glycemic control. Emerging evidence indicates that up to 80% of patients with T2DM undergoing Roux-en-Y gastric bypass (RYGB) experience complete remission of their T2DM and the majority of remissions occur almost immediately following the operation. Obestatin is a 23-amino-acid peptide, which is not only thought to suppress food intake and decrease gastric emptying but also found to exert survival effects in pancreatic β cells, increase glucose-stimulated insulin secretion, and reduce insulin resistance and inflammation. In addition, some researchers demonstrated that obestatin is a nutritional marker reflecting body adiposity and insulin resistance. Although results from previous studies were conflicting, the peripheral blood concentrations of obestatin were changed after RYGB. Therefore, regulation of obestatin level may be another mechanism for RYGB-induced remission of T2DM. In this article, we review briefly the effect of RYGB on T2DM in humans and offer an overview of the published data on the effects of RYGB on obestatin level in patients with T2DM. Furthermore, the possible roles of obestatin in the remission of T2DM following RYGB are also reviewed. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jian-Li Wang
- Qingdao University, Qingdao, China
- Department of General Surgery 1, The Affiliated Hospital of Chengde Medical College, Chengde City, China
| | - Xian-Hui Xu
- Department of General Surgery, No. 401 Hospital of People's Liberation Army, Qingdao, China
| | - Xue-Jun Zhang
- Department of General Surgery 1, The Affiliated Hospital of Chengde Medical College, Chengde City, China
| | - Wei-Hua Li
- Department of General Surgery, No. 401 Hospital of People's Liberation Army, Qingdao, China
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16
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Razzaghy-Azar M, Nourbakhsh M, Pourmoteabed A, Nourbakhsh M, Ilbeigi D, Khosravi M. An Evaluation of Acylated Ghrelin and Obestatin Levels in Childhood Obesity and Their Association with Insulin Resistance, Metabolic Syndrome, and Oxidative Stress. J Clin Med 2016; 5:jcm5070061. [PMID: 27348010 PMCID: PMC4961992 DOI: 10.3390/jcm5070061] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 05/16/2016] [Accepted: 06/01/2016] [Indexed: 12/27/2022] Open
Abstract
Background: Ghrelin is a 28-amino acid peptide with an orexigenic property, which is predominantly produced by the stomach. Acylated ghrelin is the active form of this hormone. Obestatin is a 23-amino acid peptide which is produced by post-translational modification of a protein precursor that also produces ghrelin. Obestatin has the opposite effect of ghrelin on food intake. The aim of this study was to evaluate acylated ghrelin and obestatin levels and their ratio in obese and normal-weight children and adolescents, and their association with metabolic syndrome (MetS) parameters. Methods: Serum acyl-ghrelin, obestatin, leptin, insulin, fasting plasma glucose (FPG), lipid profile, and malondialdehyde (MDA) were evaluated in 73 children and adolescents (42 obese and 31 control). Insulin resistance was calculated by a homeostasis model assessment of insulin resistance (HOMA-IR). MetS was determined according to IDF criteria. Results: Acyl-ghrelin levels were significantly lower in obese subjects compared to the control group and lower in obese children with MetS compared to obese subjects without MetS. Obestatin was significantly higher in obese subjects compared to that of the control, but it did not differ significantly among those with or without MetS. Acyl-ghrelin to obestatin ratio was significantly lower in obese subjects compared to that in normal subjects. Acyl-ghrelin showed significant negative and obestatin showed significant positive correlations with body mass index (BMI), BMI Z-score, leptin, insulin, and HOMA-IR. Acyl-ghrelin had a significant negative correlation with MDA as an index of oxidative stress. Conclusion: Ghrelin is decreased and obestatin is elevated in obesity. Both of these hormones are associated with insulin resistance, and ghrelin is associated with oxidative stress. The balance between ghrelin and obestatin seems to be disturbed in obesity.
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Affiliation(s)
- Maryam Razzaghy-Azar
- Metabolic Disorders Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, 1411715851 Tehran, Iran.
- H. Aliasghar Hospital, Iran University of Medical Sciences, 1449614535 Tehran, Iran.
| | - Mitra Nourbakhsh
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, 1449614535 Tehran, Iran.
| | | | - Mona Nourbakhsh
- H. Aliasghar Hospital, Iran University of Medical Sciences, 1449614535 Tehran, Iran.
| | - Davod Ilbeigi
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, 1417614418 Tehran, Iran.
| | - Mohsen Khosravi
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, 1449614535 Tehran, Iran.
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17
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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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Cowan E, Kumar P, Burch KJ, Grieve DJ, Green BD, Graham SF. Treatment of lean and diet-induced obesity (DIO) mice with a novel stable obestatin analogue alters plasma metabolite levels as detected by untargeted LC-MS metabolomics. Metabolomics 2016; 12:124. [PMID: 27471436 PMCID: PMC4932145 DOI: 10.1007/s11306-016-1063-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 03/31/2016] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Obestatin is a controversial gastrointestinal peptide purported to have metabolic actions. OBJECTIVES This study investigated whether treatment with a stable obestatin analogue (PEG-OB(Cys10, Cys13)) changed plasma metabolite levels firstly in lean and subsequently in diet-induced obesity (DIO) C57BL6/J mice. METHODS Untargeted LC-HRMS metabolomics experiments were carried out in ESI + mode with plasma extracts from both groups of animals. Data were normalised, multivariate and univariate statistical analysis performed and metabolites of interest putatively identified. RESULTS In lean mice, 39 metabolites were significantly changed by obestatin treatment and the majority of these were increased, including various C16 and C18 moieties of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and monoacylglycerol, along with vitamin A, vitamin D3, tyrosine, acetylcarnitine and 2α-(hydroxymethyl)-5α-androstane-3β,17β-diol. Decreased concentrations of glycolithocholic acid, 3-dehydroteasterone and various phospholipids were observed. In DIO mice, 25 metabolites were significantly affected and strikingly, the magnitudes of changes here were generally much greater in DIO mice than in lean mice, and in contrast, the majority of metabolite changes were decreases. Four metabolites affected in both groups included glycolithocholic acid, and three different long-chain (C18) phospholipid molecules (phosphatidylethanolamine, platelet activating factor (PAF), and monoacylglycerol). Metabolites exclusively affected in DIO mice included various phosphatidylcholines, lysophosphatidylcholines and fatty acyls, as well as creatine and oxidised glutathione. CONCLUSION This investigation demonstrates that obestatin treatment affects phospholipid turnover and influences lipid homeostasis, whilst providing convincing evidence that obestatin may be acting to ameliorate diet-induced impairments in lipid metabolism, and it may influence steroid, bile acid, PAF and glutathione metabolism.
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Affiliation(s)
- Elaine Cowan
- />Institute for Global Food Security, Queen’s University of Belfast, Belfast, BT9 5BN Northern Ireland, UK
| | - Praveen Kumar
- />Beaumont Research Institute, 3811 W. 13 Mile Road, Royal Oak, MI 48073 USA
| | - Kerry J. Burch
- />Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast, BT9 7AE Northern Ireland, UK
| | - David J. Grieve
- />Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast, BT9 7AE Northern Ireland, UK
| | - Brian D. Green
- />Institute for Global Food Security, Queen’s University of Belfast, Belfast, BT9 5BN Northern Ireland, UK
| | - Stewart F. Graham
- />Beaumont Research Institute, 3811 W. 13 Mile Road, Royal Oak, MI 48073 USA
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19
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Mondello P, Lacquaniti A, Mondello S, Bolignano D, Pitini V, Aloisi C, Buemi M. Emerging markers of cachexia predict survival in cancer patients. BMC Cancer 2014; 14:828. [PMID: 25400234 PMCID: PMC4239407 DOI: 10.1186/1471-2407-14-828] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 10/29/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Cachexia may occur in 40% of cancer patients, representing the major cause of death in more than 20% of them. The aim of this study was to investigate the role of leptin, ghrelin and obestatin as diagnostic and predictive markers of cachexia in oncologic patients. Their impact on patient survival was also evaluated. METHODS 140 adults with different cancer diagnoses were recruited. Thirty healthy volunteers served as control. Serum ghrelin, obestatin and leptin were tested at baseline and after a follow-up period of 18 months. RESULTS Ghrelin levels were significantly higher in cancer patients than in healthy subjects (573.31 ± 130 vs 320.20 ± 66.48 ng/ml, p < 0.0001), while obestatin (17.42 ± 7.12 vs 24.89 ± 5.54 ng/ml, p < 0.0001) and leptin (38.4 ± 21.2 vs 76.28 ± 17.48 ng/ml, p < 0.0001) values were lower. At ROC analyses the diagnostic profile of ghrelin (AUC 0.962; sensitivity 83%; specificity 98%), obestatin (AUC 0.798; sensitivity 74.5%; specificity 81.5%) and leptin (AUC 0.828; sensitivity 79%; specificity 73%) was superior to that of albumin (AUC 0.547; sensitivity 63%, specificity 69.4%) for detecting cachexia among cancer patients. On Cox multivariate analyses ghrelin (HR 1.02; 95% CI 1.01 - 1.03; p < 0.0001) and leptin (HR 0.94; 95% CI 0.92 - 0.96; p < 0.0001) were significant predictors of death even after correction for other known risk factors such as presence of metastasis and chronic kidney disease. CONCLUSION Ghrelin and leptin are promising biomarkers to diagnose cachexia and to predict survival in cancer patients.
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Affiliation(s)
- Patrizia Mondello
- />Department of Human Pathology, University of Messina, Via Consolare Valeria, 98125 Messina, Italy
| | - Antonio Lacquaniti
- />Department of Internal Medicine, University of Messina, Messina, Italy
| | - Stefania Mondello
- />Department of Neurosciences, University of Messina, Messina, Italy
| | | | - Vincenzo Pitini
- />Department of Human Pathology, University of Messina, Via Consolare Valeria, 98125 Messina, Italy
| | - Carmela Aloisi
- />Department of Internal Medicine, University of Messina, Messina, Italy
| | - Michele Buemi
- />Department of Internal Medicine, University of Messina, Messina, Italy
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20
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Prodam F, Filigheddu N. Ghrelin gene products in acute and chronic inflammation. Arch Immunol Ther Exp (Warsz) 2014; 62:369-84. [PMID: 24728531 DOI: 10.1007/s00005-014-0287-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/21/2014] [Indexed: 12/27/2022]
Abstract
Ghrelin gene products--the peptides ghrelin, unacylated ghrelin, and obestatin--have several actions on the immune system, opening new perspectives within neuroendocrinology, metabolism and inflammation. The aim of this review is to summarize the available evidence regarding the less known role of these peptides in the machinery of inflammation and autoimmunity, outlining some of their most promising therapeutic applications.
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Affiliation(s)
- Flavia Prodam
- Departmant of Health Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Novara, Italy
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21
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Rocha RA, Frigeri HR, Santos-Weiss ICRD, Réa RR, Souza EMD, Rego FGDM, Picheth G. Preproghrelin polymorphism Q90L (rs4684677) in gestational diabetes. ACTA ACUST UNITED AC 2014; 58:83-4. [DOI: 10.1590/0004-2730000003176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 12/28/2013] [Indexed: 11/22/2022]
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22
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Gahete MD, Rincón-Fernández D, Villa-Osaba A, Hormaechea-Agulla D, Ibáñez-Costa A, Martínez-Fuentes AJ, Gracia-Navarro F, Castaño JP, Luque RM. Ghrelin gene products, receptors, and GOAT enzyme: biological and pathophysiological insight. J Endocrinol 2014; 220:R1-24. [PMID: 24194510 DOI: 10.1530/joe-13-0391] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin is a 28-amino acid acylated hormone, highly expressed in the stomach, which binds to its cognate receptor (GHSR1a) to regulate a plethora of relevant biological processes, including food intake, energy balance, hormonal secretions, learning, inflammation, etc. However, ghrelin is, in fact, the most notorious component of a complex, intricate regulatory system comprised of a growing number of alternative peptides (e.g. obestatin, unacylated ghrelin, and In1-ghrelin, etc.), known (GHSRs) and, necessarily unknown receptors, as well as modifying enzymes (e.g. ghrelin-O-acyl-transferase), which interact among them as well as with other regulatory systems in order to tightly modulate key (patho)-physiological processes. This multiplicity of functions and versatility of the ghrelin system arise from a dual, genetic and functional, complexity. Importantly, a growing body of evidence suggests that dysregulation in some of the components of the ghrelin system can lead to or influence the development and/or progression of highly concerning pathologies such as endocrine-related tumors, inflammatory/cardiovascular diseases, and neurodegeneration, wherein these altered components could be used as diagnostic, prognostic, or therapeutic targets. In this context, the aim of this review is to integrate and comprehensively analyze the multiple components and functions of the ghrelin system described to date in order to define and understand its biological and (patho)-physiological significance.
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Affiliation(s)
- Manuel D Gahete
- Department of Cell Biology, Physiology and Immunology, Campus Universitario de Rabanales, Edificio Severo Ochoa (C6), Planta 3, University of Córdoba, 14014-Córdoba; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), University of Córdoba; Reina Sofia University Hospital, Córdoba; and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
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23
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Gesmundo I, Gallo D, Favaro E, Ghigo E, Granata R. Obestatin: a new metabolic player in the pancreas and white adipose tissue. IUBMB Life 2013; 65:976-82. [PMID: 24217898 DOI: 10.1002/iub.1226] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/10/2013] [Accepted: 10/11/2013] [Indexed: 01/14/2023]
Abstract
Obestatin is a 23 amino acid amidated peptide, member of the preproghrelin gene-derived peptides. Initially, obestatin was reported to exert opposite effects to those of ghrelin on food intake and body weight gain, through interaction with GPR39; however, these findings are still strongly debated and obestatin biological role remains largely unknown. Interestingly, binding of obestatin to the glucagon-like peptide 1 receptor has been recently suggested. Despite being a controversial peptide, recent findings have clearly indicated that obestatin is indeed a multifunctional peptide, exerting a variety of effects, such as stimulation of cell proliferation, survival and differentiation, influence on glucose and lipid metabolism, as well as anti-inflammatory and cardioprotective actions. Its positive effects on glucose and lipid metabolism candidate this peptide as a potential therapeutic tool in pathological conditions such as insulin resistance and diabetes.
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Affiliation(s)
- Iacopo Gesmundo
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
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24
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Ren G, He Z, Cong P, Yu J, Qin Y, Chen Y, Liu X. Effect of TAT-obestatin on proliferation, differentiation, apoptosis and lipolysis in 3T3-L1 preadipocytes. J Pept Sci 2013; 19:684-91. [PMID: 24106000 DOI: 10.1002/psc.2550] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/17/2013] [Accepted: 08/13/2013] [Indexed: 12/11/2022]
Abstract
It has been reported that obestatin regulates adipocyte metabolism via receptors on the cell surface. We wondered whether obestatin can interact with intracellular components that activated signalling pathways in adipocytes. Because obestatin (human) only presents one lysine (at position 10), which cannot penetrate the cell membrane, therefore, we used a cell-permeable peptide TAT (49-57) as a vector to carry obestatin across the cell membrane. The goal of this study was to further understand the function of obestatin after penetrating the cell membrane. Our results showed that TAT-obestatin could cross the 3T3-L1 cell membrane in the absence of cytotoxicity. TAT-obestatin showed no effect on the proliferation of 3T3-L1 preadipocytes. In contrast, obestatin significantly stimulated proliferation at a dose of 10(-11) M and 10(-13) M. In addition, TAT-obestatin demonstrated a more potent inhibitory effect on cell apoptosis induced by serum starvation than that of obestatin. During the progress of adipocyte differentiation, TAT-obestatin and obestatin had no effect on adipogenesis. In the lipolysis assay, TAT-obestatin significantly increased glycerol and free fatty acid release from 3T3-L1 adipocytes after 3 h treatment but showed no significant effect on lipolysis after 24 h and 48 h of treatment. In contrast, obestatin (10(-7) M) had no effect on glycerol release after 3, 24 and 48 h of treatment. The difference between the effect of TAT-obestatin and obestatin on adipocytes metabolism indicated that TAT-obestatin may trigger intracellular signalling as well as signalling at the cell membrane.
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Affiliation(s)
- Guangcai Ren
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China
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25
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Baragli L, Grande C, Gesmundo I, Settanni F, Taliano M, Gallo D, Gargantini E, Ghigo E, Granata R. Obestatin enhances in vitro generation of pancreatic islets through regulation of developmental pathways. PLoS One 2013; 8:e64374. [PMID: 23741322 PMCID: PMC3669302 DOI: 10.1371/journal.pone.0064374] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 04/11/2013] [Indexed: 01/17/2023] Open
Abstract
Availability of large amounts of in vitro generated β-cells may support replacement therapy in diabetes. However, methods to obtain β-cells from stem/progenitor cells are limited by inefficient endocrine differentiation. We have recently shown that the ghrelin gene product obestatin displays beneficial effects on pancreatic β-cell survival and function. Obestatin prevents β-cell apoptosis, preserves β-cell mass and stimulates insulin secretion in vitro and in vivo, in both normal and diabetic conditions. In the present study, we investigated whether obestatin may promote in vitro β-cell generation from mouse pancreatic islet-derived precursor cells. Treatment of cultured islets of Langerhans with obestatin (i) enriched cells expressing the mesenchymal/neuronal marker nestin, which is associated with pancreatic precursors; (ii) increased cell survival and reduced apoptosis during precursor selection; (iii) promoted the generation of islet-like cell clusters (ICCs) with increased insulin gene expression and C-peptide secretion. Furthermore, obestatin modulated the expression of fibroblast growth factor receptors (FGFRs), Notch receptors and neurogenin 3 (Ngn3) during islet-derived precursor cell selection and endocrine differentiation. These results indicate that obestatin improves the generation of functional β-cells/ICCs in vitro, suggesting implications for cell-based replacement therapy in diabetes. Moreover, obestatin may play a role in regulating pathways involved in pancreas development and regeneration.
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Affiliation(s)
- lessandra Baragli
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Cristina Grande
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Iacopo Gesmundo
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Fabio Settanni
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Marina Taliano
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Davide Gallo
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Eleonora Gargantini
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Ezio Ghigo
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Riccarda Granata
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of Torino, Torino, Italy
- * E-mail:
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26
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Ren G, He Z, Cong P, Chen H, Guo Y, Yu J, Liu Z, Ji Q, Song Z, Chen Y. Peripheral administration of TAT-obestatin can influence the expression of liporegulatory genes but fails to affect food intake in mice. Peptides 2013; 42:8-14. [PMID: 23313740 DOI: 10.1016/j.peptides.2013.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/03/2013] [Accepted: 01/03/2013] [Indexed: 12/14/2022]
Abstract
Obestatin is a 23-amino-acid peptide originally regarded as an anorexigenic factor. However, most of the subsequent studies failed to confirm the initially reported anorexigenic properties of obestatin. Obestatin is incapable of crossing the blood brain barrier (BBB), which may affect its biological function. Here, we report the physiological effects of obestatin in mice after intraperitoneal administration of obestatin conjugated to the cell-permeable peptide TAT, which is capable of delivering different types of proteins through the BBB. Acute peripheral administration of 1 μmol/kg of TAT-obestatin did not influence the 24 h cumulative food intake and body weight gain of mice that were fasted for 18 h. Fed mice were injected intraperitoneally with 100 nmol/kg of TAT-obestatin daily for 25 d. Compared with control groups, on day 3, the gain in body weight was significantly altered; on day 7, abdominal fat mass was remarkably reduced; however, on day 25, there was a surprisingly notable increase in abdominal and epididymal fat mass. In comparison with control groups, on day 25, the expression levels of adiponectin, ADD1, C/EBPα, PPARG and GLUT4 were significantly up-regulated in liver tissues; in white adipose tissue, the expression level of C/EBPα was significantly up-regulated, but adiponectin and GLUT4 were significantly down-regulated. In addition, GPR39, the suspected receptor of obestatin, was up-regulated in white adipose tissue on day 25. These findings suggest that TAT-obestatin might play a role in white adipose tissue metabolism, but its physiological effects on food intake and body weight gain regulation remain unclear.
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Affiliation(s)
- Guangcai Ren
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510006, People's Republic of China
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27
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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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Boutsikou T, Briana DD, Boutsikou M, Kafalidis G, Stamati L, Baka S, Hassiakos D, Gourgiotis D, Malamitsi-Puchner A. Cord blood chemerin and obestatin levels in large for gestational age infants. J Matern Fetal Neonatal Med 2012; 26:123-6. [PMID: 22963327 DOI: 10.3109/14767058.2012.728648] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To investigate possible alterations in cord blood levels of adipokines, chemerin and obestatin (secreted by adipose tissue and associated with later development of insulin resistance/metabolic syndrome), as well as insulin, in large for gestational age (LGA) and appropriate for gestational age (AGA) pregnancies, granted that these groups differ in body fat mass and metabolic/endocrine mechanisms. METHODS Cord blood chemerin, obestatin, and insulin concentrations were prospectively measured in 40 LGA (9 born from diabetic and 31 from nondiabetic mothers) and 40 AGA singleton full-term infants. RESULTS Cord blood chemerin concentrations were significantly higher in LGA compared with AGA neonates (b = 38.91, SE 9.29, p < 0.001). In contrast, no significant differences in obestatin concentrations were observed between groups. Insulin levels were significantly elevated as customized centiles increased (b = 0.003, SE = 0.001, p = 0.032). CONCLUSIONS Higher chemerin concentrations in LGA neonates possibly reflect the increased adipose tissue in this group. Lack of difference between the two groups in circulating levels of obestatin-possibly a sensitive marker of insulin resistance-might be due to development of metabolic disorders later in life.
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Affiliation(s)
- Theodora Boutsikou
- Neonatal Division, 2nd Department of Obstetrics and Gynecology, Athens University, Medical School, Athens, Greece
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29
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Functional and structural features of adipokine family. Cytokine 2012; 61:1-14. [PMID: 23022179 DOI: 10.1016/j.cyto.2012.08.036] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 08/29/2012] [Accepted: 08/31/2012] [Indexed: 12/13/2022]
Abstract
In the mid-1990s, the interest in adipose tissue was revived by the discovery of leptin. Since then numerous other hormones have been isolated from white adipose tissue that has no longer considered an inert tissue mainly devoted to energy storage but emerged as an active participant in regulating physiologic and pathologic processes, including immunity and inflammation. Adipose tissue produces and releases a variety of proinflammatory and anti-inflammatory factors, including the adipokines, as well as cytokines and chemokines. Proinflammatory molecules produced by adipose tissue have been implicated as active participants in the development of insulin resistance and the increased risk of cardiovascular disease associated with obesity. In contrast, reduced leptin levels might predispose to increased susceptibility to infection caused by reduced T-cell responses in malnourished individuals. Altered adipokine levels have been observed in a variety of inflammatory conditions, although their pathogenic role has not been completely clarified. In this paper we want to review: (i) the role of adipose tissue in different biological processes, (ii) the functional and structural description of all the known adipokines subdivided in different subfamilies, (iii) the adipokine involvement in obesity and cancers, and (iv) the adipokine interactome.
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Obestatin and insulin in pancreas of newborn diabetic rats treated with exogenous ghrelin. Acta Histochem 2012; 114:349-57. [PMID: 21803403 DOI: 10.1016/j.acthis.2011.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 07/06/2011] [Accepted: 07/07/2011] [Indexed: 01/24/2023]
Abstract
The aim of the study was to evaluate the effect of ghrelin treatment on obestatin, insulin gene expression and biochemical parameters in the pancreas of newborn-streptozocin (STZ) diabetic rats. Rats were divided into 4 groups. Group I: control rats treated with physiological saline; group II: control rats treated with 100 μg/kg/day ghrelin; group III: two days after birth rats that received 100mg/kg STZ injected as a single dose to induce neonatal diabetes; group IV: neonatal-STZ-diabetic rats treated with ghrelin for four weeks. Sections of the pancreas were examined with immunohistochemistry for the expression of obestatin and insulin and in situ hybridization for the expression of insulin mRNA. The blood glucose levels were measured. Tissue homogenates were used for protein, glutathione, lipid peroxidation and non-enzymatic glycosylation levels and antioxidant enzyme analysis. There was a significant difference in blood glucose levels in newborn-STZ-diabetic rats compared to ghrelin treated diabetic rats at weeks 1, 2 and 4. In group IV, pancreatic non-enzymatic glycosylation and lipid peroxidation levels were decreased, however, glutathione levels and enzymatic activities were increased. Insulin peptide and mRNA (+) signals in islets of Langerhans and obestatin immunopositive cell numbers showed an increase in group IV compared to group III. These results suggest that administration of ghrelin to newborn rats may prevent effects of diabetes.
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31
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Baykus Y, Gurates B, Aydin S, Celik H, Kavak B, Aksoy A, Sahin İ, Deniz R, Gungor S, Guzel SP, Minareci Y. Changes in serum obestatin, preptin and ghrelins in patients with Gestational Diabetes Mellitus. Clin Biochem 2012; 45:198-202. [DOI: 10.1016/j.clinbiochem.2011.08.1131] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/10/2011] [Accepted: 08/15/2011] [Indexed: 11/29/2022]
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Baragli A, Lanfranco F, Allasia S, Granata R, Ghigo E. Neuroendocrine and metabolic activities of ghrelin gene products. Peptides 2011; 32:2323-32. [PMID: 22056513 DOI: 10.1016/j.peptides.2011.10.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 10/03/2011] [Accepted: 10/25/2011] [Indexed: 12/15/2022]
Abstract
Acylated ghrelin (AG) is a 28 amino acid gastric peptide a natural ligand for the growth hormone secretagogue (GHS) receptor type 1a (GHS-R1a), endowed with GH-secreting and orexigenic properties. Besides, ghrelin exerts several peripheral metabolic actions, including modulation of glucose homeostasis and stimulation of adipogenesis. Notably, AG administration causes hyperglycemia in rodents as in humans. Ghrelin pleiotropy is supported by a widespread expression of the ghrelin gene, of GHS-R1a and other unknown ghrelin binding sites. The existence of alternative receptors for AG, of several natural ligands for GHS-R1a and of acylation-independent ghrelin non-neuroendocrine activities, suggests that there might be a complex 'ghrelin system' not yet completely explored. Moreover, the patho-physiological implications of unacylated ghrelin (UAG), and obestatin (Ob), the other two ghrelin gene-derived peptides, need to be clarified. Within the next few years, we may better understand the 'ghrelin system', where we might envisage clinical applications.
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Affiliation(s)
- Alessandra Baragli
- Laboratory of Molecular and Cellular Endocrinology, Division of Endocrinology, Department of Internal Medicine, University of Turin, Turin, Italy.
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Nishi Y, Yoh J, Hiejima H, Kojima M. Structures and molecular forms of the ghrelin-family peptides. Peptides 2011; 32:2175-82. [PMID: 21839128 DOI: 10.1016/j.peptides.2011.07.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 07/08/2011] [Accepted: 07/22/2011] [Indexed: 11/23/2022]
Abstract
Ghrelin is an acylated peptide hormone produced mainly from the stomach. The major active products of the ghrelin gene in the stomach of rats, mice and humans are 28-amino acid peptides acylated at the serine-3 position with an n-octanoyl group (C8:0), called simply ghrelin. However, recent studies have revealed that the ghrelin gene can generate a variety of bioactive molecules besides ghrelin. These include acyl forms of ghrelin other than C8:0-ghrelin (i.e., n-decanoyl ghrelin or n-decenoyl ghrelin), des-acyl ghrelin, obestatin and ghrelin-associated peptides originated from the ghrelin gene. This review surveys the structures of the ghrelin peptides and molecular forms of ghrelin gene-derived products, and summarizes the knowledge about the functions of these peptides, with an emphasis on the acyl forms of the ghrelin peptide.
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Affiliation(s)
- Yoshihiro Nishi
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan.
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From chronic kidney disease to transplantation: the roles of obestatin. ACTA ACUST UNITED AC 2011; 171:48-52. [PMID: 21784109 DOI: 10.1016/j.regpep.2011.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 05/18/2011] [Accepted: 07/08/2011] [Indexed: 11/22/2022]
Abstract
BACKGROUND Kidney transplantation is the therapy of choice in most cases of end stage renal disease. The purpose of the present study was to evaluate serum obestatin levels in kidney transplant recipients (Tx), compare levels in patients with renal failure (CKD) with those in healthy subjects (HS), and to assess the role of this hormone in energetic metabolism. PATIENTS AND METHODS A total of 95 subjects were studied: 40 were Tx; 35 had CKD and 20 were HS. Inclusion criteria were age>18years and good allograft function. Patients with an inflammatory disease or a diagnosis of cancer were excluded from the study. RESULTS Obestatin levels in Tx patients were significantly lower than in HS (3.5 [3-4.8] versus 11 [8.56-28.60] ng/mL; p<0.0001) and patients with CKD (3.5 [3-4.8] versus 4.7 [3, 5-6, 1] ng/mL; p=0.008). At univariate analysis, a direct correlation was found between obestatin and calcemia (p: 0.0001; r: 0.51), phosphoremia (p: 0.0005; r: 0, 46), calcium-phosphate product (p<0.0001; r:0.53), and parathormone (p: 0.01; r: 0.32), whereas significant inverse correlations were evidenced for BMI (p<0.0001; r: -0.52). At multivariate analysis, significance was maintained for the correlation between obestatin and phosphoremia (β=0.47; p=0.008), for the calcium-phosphate product (β=0.55; p=0.0005) and for BMI (β=-0.53; p=0.01). CONCLUSION Obestatin, present in lower levels in Tx patients than in CKD patients and HS, plays a role in energy metabolism, affecting BMI and the metabolism of calcium-phosphorus.
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Seim I, Walpole C, Amorim L, Josh P, Herington A, Chopin L. The expanding roles of the ghrelin-gene derived peptide obestatin in health and disease. Mol Cell Endocrinol 2011; 340:111-7. [PMID: 21459124 DOI: 10.1016/j.mce.2011.03.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 03/23/2011] [Accepted: 03/25/2011] [Indexed: 01/18/2023]
Abstract
Obestatin is a 23 amino acid, ghrelin gene-derived peptide hormone produced in the stomach and a range of other tissues throughout the body. While it was initially reported that obestatin opposed the actions of ghrelin with regards to appetite and food intake, it is now clear that obestatin is not an endogenous ghrelin antagonist, but it is a multi-functional peptide hormone in its own right. In this review we will discuss the controversies associated with the discovery of obestatin and explore emerging central and peripheral roles of obestatin, which includes adipogenesis, pancreatic homeostasis and cancer.
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Affiliation(s)
- Inge Seim
- Queensland University of Technology, Queensland, Brisbane, Australia
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36
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Li JB, Asakawa A, Cheng K, Li Y, Chaolu H, Tsai M, Inui A. Biological effects of obestatin. Endocrine 2011; 39:205-11. [PMID: 21424587 DOI: 10.1007/s12020-011-9453-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 02/05/2011] [Indexed: 10/18/2022]
Abstract
Obestatin, a 23-amino-acid peptide, is derived from the preproghrelin precursor. Obestatin was identified in 2005 as a hormone regulating food intake and energy, and having opposite effects to those of ghrelin. However, as studies have progressed, many disputes on the physiological function of obestatin have emerged. The food intake suppressive effects of obestatin have not been replicated in many studies. Nonetheless, many biological roles of obestatin have been revealed, and obestatin is thought to be associated with a variety of biological functions such as feeding, drinking, incretion, memory, and sleep, and with neuropsychiatric manifestations. The biological effects of obestatin will be reviewed in this article.
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Affiliation(s)
- Jiang-Bo Li
- Department of Social and Behavioral Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
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Lacquaniti A, Donato V, Chirico V, Buemi A, Buemi M. Obestatin: An Interesting but Controversial Gut Hormone. ANNALS OF NUTRITION AND METABOLISM 2011; 59:193-9. [DOI: 10.1159/000334106] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 09/30/2011] [Indexed: 12/14/2022]
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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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Kumar R, Salehi A, Rehfeld JF, Höglund P, Lindström E, Håkanson R. Proghrelin peptides: Desacyl ghrelin is a powerful inhibitor of acylated ghrelin, likely to impair physiological effects of acyl ghrelin but not of obestatin A study of pancreatic polypeptide secretion from mouse islets. ACTA ACUST UNITED AC 2010; 164:65-70. [PMID: 20619300 DOI: 10.1016/j.regpep.2010.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 06/01/2010] [Accepted: 06/28/2010] [Indexed: 01/25/2023]
Abstract
BACKGROUND Proghrelin, produced by the ghrelin (A-like) cells of the gastric mucosa, gives rise to cleavage products, including desacyl ghrelin, acyl ghrelin and obestatin. The products are thought to be secreted concomitantly. In an earlier study we found acyl ghrelin and obestatin, but not desacyl ghrelin, to suppress the release of hormones from isolated islets of mouse and rat pancreas. RESULTS Using isolated mouse pancreatic islets to study the suppression of the spontaneous secretion of pancreatic polypeptide (PP) by acyl ghrelin and obestatin, we determined the EC(50) values for the two peptides. For acyl ghrelin it was 2 x 10(-13)M (ranging from 1.7 to 2.8 x 10(-13)M), for obestatin it was 10(-13)M (ranging from 0.3 to 1.1 x 10(-13)M). The Hill coefficient (i.e. the midpoint slope) for the acyl ghrelin dose-response curve was 0.30 (ranging from 0.21 to 0.35); the corresponding value for obestatin was 0.35 (ranging from 0.21 to 0.35). The PP-releasing effect of acyl ghrelin, but not that of obestatin, was counteracted by desacyl ghrelin. The acyl ghrelin dose-response curve was shifted to the right in a parallel manner by increasing concentrations of desacyl ghrelin. A Schild plot was constructed with a slope of 0.78, giving an apparent pA(2) value of 14. CONCLUSIONS The results favour the view that acyl ghrelin and obestatin suppress spontaneous PP secretion at physiologically relevant concentrations and that they act on separate receptors. However, we conclude also that desacyl ghrelin acts as a competitive, surmountable (and quite potent) inhibitor of acyl ghrelin. In view of the allegedly high circulating concentrations of desacyl ghrelin it is to be expected that the effect of acyl ghrelin - but not that of obestatin - will be impaired, in fact probably severely blunted by desacyl ghrelin, thereby compromising the functional significance of circulating acyl ghrelin. In addition, we suggest that isolated pancreatic islets are well suited for studies of receptors to acyl ghrelin and obestatin, and that suppression of PP secretion represents a convenient way to measure the effect of both these peptides.
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Affiliation(s)
- Rajesh Kumar
- Department of Clinical Science, Malmö University Hospital, UMAS, SE-205 02 Malmö, Sweden
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Chen CY, Asakawa A, Fujimiya M, Lee SD, Inui A. Ghrelin gene products and the regulation of food intake and gut motility. Pharmacol Rev 2010; 61:430-81. [PMID: 20038570 DOI: 10.1124/pr.109.001958] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A breakthrough using "reverse pharmacology" identified and characterized acyl ghrelin from the stomach as the endogenous cognate ligand for the growth hormone (GH) secretagogue receptor (GHS-R) 1a. The unique post-translational modification of O-n-octanoylation at serine 3 is the first in peptide discovery history and is essential for GH-releasing ability. Des-acyl ghrelin, lacking O-n-octanoylation at serine 3, is also produced in the stomach and remains the major molecular form secreted into the circulation. The third ghrelin gene product, obestatin, a novel 23-amino acid peptide identified from rat stomach, was found by comparative genomic analysis. Three ghrelin gene products actively participate in modulating appetite, adipogenesis, gut motility, glucose metabolism, cell proliferation, immune, sleep, memory, anxiety, cognition, and stress. Knockdown or knockout of acyl ghrelin and/or GHS-R1a, and overexpression of des-acyl ghrelin show benefits in the therapy of obesity and metabolic syndrome. By contrast, agonism of acyl ghrelin and/or GHS-R1a could combat human anorexia-cachexia, including anorexia nervosa, chronic heart failure, chronic obstructive pulmonary disease, liver cirrhosis, chronic kidney disease, burn, and postsurgery recovery, as well as restore gut dysmotility, such as diabetic or neurogenic gastroparesis, and postoperative ileus. The ghrelin acyl-modifying enzyme, ghrelin O-Acyltransferase (GOAT), which attaches octanoate to serine-3 of ghrelin, has been identified and characterized also from the stomach. To date, ghrelin is the only protein to be octanylated, and inhibition of GOAT may have effects only on the stomach and is unlikely to affect the synthesis of other proteins. GOAT may provide a critical molecular target in developing novel therapeutics for obesity and type 2 diabetes.
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Affiliation(s)
- Chih-Yen Chen
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Japan
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Abstract
Under in vivo conditions, the study of physiological and pharmacological functions of an organ is difficult due to whole-body interactions with the organ. Thus, an in vitro technique for the perfusion of isolated pancreata was developed for physiologic and response studies including the investigation of endocrine function and secretory responsiveness under a variety of diabetes-associated conditions. The pancreas is isolated from the connecting spleen, stomach, and duodenum and transferred to a pre-warmed chamber, where it is perfused in isolation from all other organs. A detailed description of the isolation and perfusion apparatus is described as well as the measurement of glucose-stimulated insulin secretion using an in-house-developed radioimmunoassay.
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Affiliation(s)
- Edward T Wargent
- Clore Laboratory, University of Buckingham, Hunter Street, Buckingham, MK18 1EG, UK.
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Ren AJ, Guo ZF, Wang YK, Lin L, Zheng X, Yuan WJ. Obestatin, obesity and diabetes. Peptides 2009; 30:439-44. [PMID: 18992781 DOI: 10.1016/j.peptides.2008.10.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/04/2008] [Accepted: 10/06/2008] [Indexed: 01/07/2023]
Abstract
The high prevalence of obesity and diabetes will lead to higher rates of morbidity and mortality. It is well known that ghrelin plays a potential role in obesity and diabetes. Obestatin, a novel 23 amino acid amidated peptide encoded by the same gene that encodes ghrelin, was initially reported to have opposite actions to ghrelin in the regulation of food intake, emptying of the stomach and body weight. Recent work suggests that obestatin also regulate beta-cell survival and insulin secretion. The ghrelin-obestatin system is, therefore, a promising target for the developing of new drugs for the treatment of obesity and diabetes. This review summarizes the interrelationship between obestatin, obesity and diabetes.
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Affiliation(s)
- An-Jing Ren
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
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