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Almulla AF, Thipakorn Y, Algon AAA, Tunvirachaisakul C, Al-Hakeim HK, Maes M. Reverse cholesterol transport and lipid peroxidation biomarkers in major depression and bipolar disorder: A systematic review and meta-analysis. Brain Behav Immun 2023; 113:374-388. [PMID: 37557967 DOI: 10.1016/j.bbi.2023.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 08/01/2023] [Accepted: 08/06/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses. OBJECTIVES To systematically review and meta-analyze all data concerning biomarkers of reverse cholesterol transport (RCT), lipid-associated antioxidants, lipid peroxidation products, and autoimmune responses to oxidatively modified lipid epitopes in MDD and BD. METHODS Databases including PubMed, Google scholar and SciFinder were searched to identify eligible studies from inception to January 10th, 2023. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. RESULTS The current meta-analysis included 176 studies (60 BD and 116 MDD) and examined 34,051 participants, namely 17,094 with affective disorders and 16,957 healthy controls. Patients with MDD and BD showed a) significantly decreased RCT (mainly lowered high-density lipoprotein cholesterol and paraoxonase 1); b) lowered lipid soluble vitamins (including vitamin A, D, and coenzyme Q10); c) increased lipid peroxidation and aldehyde formation, mainly increased malondialdehyde (MDA), 4-hydroxynonenal, peroxides, and 8-isoprostanes; and d) Immunoglobulin (Ig)G responses to oxidized low-density lipoprotein and IgM responses to MDA. The ratio of all lipid peroxidation biomarkers/all lipid-associated antioxidant defenses was significantly increased in MDD (standardized mean difference or SMD = 0.433; 95% confidence intervals (CI): 0.312; 0.554) and BD (SMD = 0.653; CI: 0.501-0.806). This ratio was significantly greater in BD than MDD (p = 0.027). CONCLUSION In MDD/BD, lowered RCT, a key antioxidant and anti-inflammatory pathway, may drive increased lipid peroxidation, aldehyde formation, and autoimmune responses to oxidative specific epitopes, which all together cause increased immune-inflammatory responses and neuro-affective toxicity.
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Affiliation(s)
- Abbas F Almulla
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Medical Laboratory Technology Department, College of Medical Technology, The Islamic University, Najaf, Iraq
| | - Yanin Thipakorn
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
| | | | - Chavit Tunvirachaisakul
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Cognitive Impairment and Dementia Research Unit, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | | | - Michael Maes
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Cognitive Impairment and Dementia Research Unit, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria; Research Institute, Medical University in Plovdiv, Plovdiv, Bulgaria; Department of Psychiatry, IMPACT Strategic Research Centre, Deakin University, Geelong, Victoria, Australia; Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea; Sichuan Provincial Center for Mental Health, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Key Laboratory of Psychosomatic Medicine, Chinese Academy of Medical Sciences, Chengdu 610072, China.
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Niknam M, Liaghat T, Zarghami M, Akrami M, Shahnematollahi SM, Ahmadipour A, Moazzen F, Soltanabadi S. Ghrelin and ghrelin/total cholesterol ratio as independent predictors for coronary artery disease: a systematic review and meta-analysis. J Investig Med 2022; 70:759-765. [PMID: 35042826 DOI: 10.1136/jim-2021-002100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2021] [Indexed: 11/04/2022]
Abstract
The present meta-analysis aimed to summarize the available data regarding the circulating levels of ghrelin in patients with cardiovascular diseases (CVDs). A comprehensive search was performed in electronic databases including PubMed, Scopus, EMBASE, and Web of Science up to January 20, 2021. Since the circulating levels of ghrelin were measured in different units across the included studies, they were expressed as the standardized mean difference (SMD) and 95% CI (summary effect size). A random-effects model comprising the DerSimonian and Laird method was used to pool SMDs. Sixteen articles (20 studies) comprised of 1087 cases and 437 controls were included. The pooled results showed that there were no significant differences between cases and controls in terms of ghrelin levels (SMD=-0.61, 95% CI -1.38 to 0.16; p=0.120; I2=96.9%, p<0.001). The ghrelin concentrations in the CAD stratum were significantly lower than in controls, whereas they increased in other disease strata. New combined biomarkers demonstrated a significant decrease in the SMD of the ghrelin/total cholesterol (TC) ratio (-1.02; 95% CI -1.74 to -0.29, p=0.000; I2=94.5%). However, no significant differences were found in the SMD of the ghrelin/high-density lipoprotein cholesterol ratio, ghrelin/low-density lipoprotein cholesterol ratio, and ghrelin/triglyceride (TG) ratio in cases with CVDs compared with the control group. Ghrelin was associated with CAD; therefore, it may be considered a biomarker for distinguishing between patients with and without CAD. Furthermore, the ghrelin/TC ratio could be proposed as a diagnostic marker for CVD.
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Affiliation(s)
- Maryam Niknam
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Taraneh Liaghat
- Cardiovascular Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mehrdad Zarghami
- Cardiology Department, Fasa University of Medical Science, Fasa, Iran
| | - Mehdi Akrami
- Cardiovascular Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Ahmad Ahmadipour
- Student Research Committee, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Fatemeh Moazzen
- Department of Hematology, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Sahar Soltanabadi
- Cardiovascular Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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3
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Deschaine SL, Leggio L. From "Hunger Hormone" to "It's Complicated": Ghrelin Beyond Feeding Control. Physiology (Bethesda) 2022; 37:5-15. [PMID: 34964687 PMCID: PMC8742734 DOI: 10.1152/physiol.00024.2021] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Discovered as a peptide involved in releasing growth hormone, ghrelin was initially characterized as the "hunger hormone." However, emerging research indicates that ghrelin appears to play an important part in relaying information regarding nutrient availability and value and adjusting physiological and motivational processes accordingly. These functions make ghrelin an interesting therapeutic candidate for metabolic and neuropsychiatric diseases involving disrupted nutrition that can further potentiate the rewarding effect of maladaptive behaviors.
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Affiliation(s)
- Sara L. Deschaine
- 1Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore and Bethesda, Maryland
| | - Lorenzo Leggio
- 1Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Baltimore and Bethesda, Maryland,2Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland,3Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, School of Public Health, Brown University, Providence, Rhode Island,4Division of Addiction Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland,5Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia
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Davis TR, Pierce MR, Novak SX, Hougland JL. Ghrelin octanoylation by ghrelin O-acyltransferase: protein acylation impacting metabolic and neuroendocrine signalling. Open Biol 2021; 11:210080. [PMID: 34315274 PMCID: PMC8316800 DOI: 10.1098/rsob.210080] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The acylated peptide hormone ghrelin impacts a wide range of physiological processes but is most well known for controlling hunger and metabolic regulation. Ghrelin requires a unique posttranslational modification, serine octanoylation, to bind and activate signalling through its cognate GHS-R1a receptor. Ghrelin acylation is catalysed by ghrelin O-acyltransferase (GOAT), a member of the membrane-bound O-acyltransferase (MBOAT) enzyme family. The ghrelin/GOAT/GHS-R1a system is defined by multiple unique aspects within both protein biochemistry and endocrinology. Ghrelin serves as the only substrate for GOAT within the human proteome and, among the multiple hormones involved in energy homeostasis and metabolism such as insulin and leptin, acts as the only known hormone in circulation that directly stimulates appetite and hunger signalling. Advances in GOAT enzymology, structural modelling and inhibitor development have revolutionized our understanding of this enzyme and offered new tools for investigating ghrelin signalling at the molecular and organismal levels. In this review, we briefly summarize the current state of knowledge regarding ghrelin signalling and ghrelin/GOAT enzymology, discuss the GOAT structural model in the context of recently reported MBOAT enzyme superfamily member structures, and highlight the growing complement of GOAT inhibitors that offer options for both ghrelin signalling studies and therapeutic applications.
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Affiliation(s)
- Tasha R Davis
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA
| | - Mariah R Pierce
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA
| | - Sadie X Novak
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA
| | - James L Hougland
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA.,BioInspired Syracuse, Syracuse University, Syracuse, NY 13244 USA
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5
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Iqbal Z, Adam S, Ho JH, Syed AA, Ammori BJ, Malik RA, Soran H. Metabolic and cardiovascular outcomes of bariatric surgery. Curr Opin Lipidol 2020; 31:246-256. [PMID: 32618731 DOI: 10.1097/mol.0000000000000696] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW Bariatric surgery is an effective therapy for morbid obesity that also improves weight-related metabolic parameters and reduces morbidity and mortality. The purpose of this review is to consolidate our current understanding of metabolic, macrovascular and microvascular benefits of bariatric surgery and to provide an update. RECENT FINDINGS Early resolution of insulin resistance and type 2 diabetes mellitus (T2DM) varies by type of bariatric surgery and appears to be mediated by changes in secretion of gut hormones, metabolism of bile acids, expression of glucose transporters and the gut microbiome. Dyslipidaemia, atherosclerosis, microvascular complications of obesity and diabetes, systemic and tissue-level inflammation show evidence of regression and hypertension improves significantly after bariatric surgery. SUMMARY Bariatric surgery leads to improvements in obesity-related metabolic comorbidities such as dyslipidaemia, HDL functionality, hypertension, T2DM, insulin resistance and inflammation. It slows the atherosclerotic process and reduces cardiovascular and all-cause mortality. Recent data have demonstrated regression of the microvascular complications of obesity and diabetes including the regeneration of small nerve fibres. The magnitude of change in short-term metabolic effects depends on the surgical procedure whilst longer term effects are related to the amount of sustained excess weight loss.
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Affiliation(s)
- Zohaib Iqbal
- Faculty of Biology, Medicine and Health, University of Manchester
- Cardiovascular Trials Unit, Manchester University NHS Foundation Trust
| | - Safwaan Adam
- Faculty of Biology, Medicine and Health, University of Manchester
- The Christie Hospital NHS Foundation Trust, Manchester
| | - Jan H Ho
- Faculty of Biology, Medicine and Health, University of Manchester
- Cardiovascular Trials Unit, Manchester University NHS Foundation Trust
| | - Akheel A Syed
- Faculty of Biology, Medicine and Health, University of Manchester
- Department of Diabetes, Endocrinology and Obesity Medicine
| | - Basil J Ammori
- Faculty of Biology, Medicine and Health, University of Manchester
- Department of Surgery, Salford Royal NHS Foundation Trust, Salford, UK
| | - Rayaz A Malik
- Faculty of Biology, Medicine and Health, University of Manchester
- Weill-Cornell Medicine-Qatar, Doha, Qatar
| | - Handrean Soran
- Faculty of Biology, Medicine and Health, University of Manchester
- The Christie Hospital NHS Foundation Trust, Manchester
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Ghrelin octanoylation by ghrelin O-acyltransferase: Unique protein biochemistry underlying metabolic signaling. Biochem Soc Trans 2019; 47:169-178. [PMID: 30626708 DOI: 10.1042/bst20180436] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/26/2018] [Accepted: 11/28/2018] [Indexed: 02/08/2023]
Abstract
Ghrelin is a small peptide hormone that requires a unique post-translational modification, serine octanoylation, to bind and activate the GHS-R1a receptor. Ghrelin signaling is implicated in a variety of neurological and physiological processes, but is most well known for its roles in controlling hunger and metabolic regulation. Ghrelin octanoylation is catalyzed by ghrelin O-acyltransferase (GOAT), a member of the membrane-bound O-acyltransferase (MBOAT) enzyme family. From the status of ghrelin as the only substrate for GOAT in the human genome to the source and requirement for the octanoyl acyl donor, the ghrelin-GOAT system is defined by multiple unique aspects within both protein biochemistry and endocrinology. In this review, we examine recent advances in our understanding of the interactions and mechanisms leading to ghrelin modification by GOAT, discuss the potential sources for the octanoyl acyl donor required for ghrelin's activation, and summarize the current landscape of molecules targeting ghrelin octanoylation through GOAT inhibition.
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Cleverdon ER, Davis TR, Hougland JL. Functional group and stereochemical requirements for substrate binding by ghrelin O-acyltransferase revealed by unnatural amino acid incorporation. Bioorg Chem 2018; 79:98-106. [PMID: 29738973 DOI: 10.1016/j.bioorg.2018.04.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/02/2018] [Accepted: 04/13/2018] [Indexed: 12/22/2022]
Abstract
Ghrelin is a small peptide hormone that undergoes a unique posttranslational modification, serine octanoylation, to play its physiological roles in processes including hunger signaling and glucose metabolism. Ghrelin O-acyltransferase (GOAT) catalyzes this posttranslational modification, which is essential for ghrelin to bind and activate its cognate GHS-R1a receptor. Inhibition of GOAT offers a potential avenue for modulating ghrelin signaling for therapeutic effect. Defining the molecular characteristics of ghrelin that lead to binding and recognition by GOAT will facilitate the development and optimization of GOAT inhibitors. We show that small peptide mimics of ghrelin substituted with 2,3-diaminopropanoic acid in place of the serine at the site of octanoylation act as submicromolar inhibitors of GOAT. Using these chemically modified analogs of desacyl ghrelin, we define key functional groups within the N-terminal sequence of ghrelin essential for binding to GOAT and determine GOAT's tolerance to backbone methylations and altered amino acid stereochemistry within ghrelin. Our study provides a structure-activity analysis of ghrelin binding to GOAT that expands upon activity-based investigations of ghrelin recognition and establishes a new class of potent substrate-mimetic GOAT inhibitors for further investigation and therapeutic interventions targeting ghrelin signaling.
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Affiliation(s)
| | - Tasha R Davis
- Department of Chemistry, Syracuse University, Syracuse, NY 13244, USA
| | - James L Hougland
- Department of Chemistry, Syracuse University, Syracuse, NY 13244, USA.
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8
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Cleverdon ER, McGovern-Gooch KR, Hougland JL. The octanoylated energy regulating hormone ghrelin: An expanded view of ghrelin's biological interactions and avenues for controlling ghrelin signaling. Mol Membr Biol 2017; 33:111-124. [PMID: 29143554 DOI: 10.1080/09687688.2017.1388930] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Ghrelin is a small peptide hormone that requires a unique post-translational modification, serine octanoylation, to bind and activate the GHS-R1a receptor. Initially demonstrated to stimulate hunger and appetite, ghrelin-dependent signaling is implicated in a variety of neurological and physiological processes influencing diseases such as diabetes, obesity, and Prader-Willi syndrome. In addition to its cognate receptor, recent studies have revealed ghrelin interacts with a range of binding partners within the bloodstream. Defining the scope of ghrelin's interactions within the body, understanding how these interactions work in concert to modulate ghrelin signaling, and developing molecular tools for controlling ghrelin signaling are essential for exploiting ghrelin for therapeutic effect. In this review, we discuss recent findings regarding the biological effects of ghrelin signaling, outline binding partners that control ghrelin trafficking and stability in circulation, and summarize the current landscape of inhibitors targeting ghrelin octanoylation.
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Affiliation(s)
| | | | - James L Hougland
- a Department of Chemistry , Syracuse University , Syracuse , NY , USA
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Satou M, Kaiya H, Nishi Y, Shinohara A, Kawada SI, Miyazato M, Kangawa K, Sugimoto H. Mole ghrelin: cDNA cloning, gene expression, and diverse molecular forms in Mogera imaizumii. Gen Comp Endocrinol 2016; 232:199-210. [PMID: 27102942 DOI: 10.1016/j.ygcen.2016.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/14/2016] [Accepted: 04/16/2016] [Indexed: 11/28/2022]
Abstract
Here, we describe cDNA cloning and purification of the ghrelin gene sequences and ghrelin peptides from the Japanese true mole, Mogera imaizumii. The gene spans >2.9kbp, has four exons and three introns, and shares structural similarity with those of terrestrial animals. Mature mole ghrelin peptide was predicted to be 28 amino acids long (GSSFLSPEHQKVQQRKESKKPPSKPQPR) and processed from a prepropeptide of 116 amino acids. To further elucidate molecular characteristics, we purified ghrelin peptides from mole stomach. By mass spectrometry, we found that the mole ghrelin peptides had higher ratios of the odd-number fatty acids (C9 and C11 as much as C8) attached to the third serine residue than other vertebrate ghrelin. Truncated forms of ghrelins such as [1-27], [1-19], [1-16] and [1-15], and that lacked the 14th glutamine residue (des-Gln14 ghrelin) were produced in the stomach. Marked expression of ghrelin mRNA in lung was observed as in stomach and brain. Phylogenetic analysis indicated that the branch of M. imaizumii has slightly higher dN/dS ratios (the nucleotide substitution rates at non-synonymous and synonymous sites) than did other eulipotyphlans. Peptide length was positively correlated with human ghrelin receptor activation, whereas the length of fatty-acyl chains showed no obvious functional correlation. The basal higher luciferase activities of the 5'-proximal promoter region of mole ghrelin were detected in ghrelin-negative C2C12 cells and hypoxic culture conditions impaired transcriptional activity. These results indicated that moles have acquired diverse species of ghrelin probably through distinctive fatty acid metabolism because of their food preferences. The results provide a gateway to understanding ghrelin metabolism in fossorial animals.
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Affiliation(s)
- Motoyasu Satou
- Department of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
| | - Hiroyuki Kaiya
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Yoshihiro Nishi
- Department of Physiology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Akio Shinohara
- Division of Bio-resources, Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan
| | - Shin-Ichiro Kawada
- Department of Zoology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Hiroyuki Sugimoto
- Department of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan.
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Satou M, Nishi Y, Hishinuma A, Hosoda H, Kangawa K, Sugimoto H. Identification of activated protein C as a ghrelin endopeptidase in bovine plasma. J Endocrinol 2015; 224:61-73. [PMID: 25349251 DOI: 10.1530/joe-14-0529] [Citation(s) in RCA: 4] [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] [Indexed: 11/08/2022]
Abstract
Ghrelin is a natural GH secretagogue first identified in the stomach. The ghrelin peptide is 28 amino acids long with an octanoic acid attached to Ser(3) near the N-terminus. This lipid modification is essential for the interaction between ghrelin and the ghrelin-specific receptor GH secretagogue receptor type 1a (GHSR1a), whereas the five or more residues of the N-terminus seem to be sufficient to activate GHSR1a to the same level as those of full-length ghrelin. In this study, we found that ghrelin was converted into smaller fragments during incubation with animal plasma in vitro and in a mouse model. Mass spectrometric analysis revealed that both acyl and desacyl ghrelin were hydrolyzed at the peptide bond between Arg(15) and Lys(16), generating an N-terminal peptide consisting of the first 15 residues. Next, we partially purified a ghrelin endopeptidase from bovine plasma and identified the enzyme as an anticoagulant serine protease-activated protein C. Octanoyl-truncated ghrelin(1-15) activated GHSR1a-dependent signaling similar to the full-length peptide, as assayed using the cell-based early-growth factor 1 reporter system. Moreover, administration of the protein C-activating agent, ProTac, to mice enhanced the production of octanoyl ghrelin(1-15) in circulation. These results indicate that ghrelin is processed into shorter peptides in circulation under thrombotic and inflammatory conditions, although high doses of the short-form or full-length ghrelin did not have any obvious effects on thromboplastin time or platelet aggregation in human plasma. Truncation of ghrelin might be responsible for altering structural characteristics such as stability, hydrophobicity, and affinity with circulating macromolecules.
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Affiliation(s)
- Motoyasu Satou
- Department of BiochemistryDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of PhysiologyKurume University School of Medicine, Kurume, Fukuoka 830-0011 JapanDepartment of Infection Control and Clinical Laboratory MedicineDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of BiochemistryNational Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Yoshihiro Nishi
- Department of BiochemistryDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of PhysiologyKurume University School of Medicine, Kurume, Fukuoka 830-0011 JapanDepartment of Infection Control and Clinical Laboratory MedicineDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of BiochemistryNational Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Akira Hishinuma
- Department of BiochemistryDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of PhysiologyKurume University School of Medicine, Kurume, Fukuoka 830-0011 JapanDepartment of Infection Control and Clinical Laboratory MedicineDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of BiochemistryNational Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Hiroshi Hosoda
- Department of BiochemistryDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of PhysiologyKurume University School of Medicine, Kurume, Fukuoka 830-0011 JapanDepartment of Infection Control and Clinical Laboratory MedicineDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of BiochemistryNational Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Kenji Kangawa
- Department of BiochemistryDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of PhysiologyKurume University School of Medicine, Kurume, Fukuoka 830-0011 JapanDepartment of Infection Control and Clinical Laboratory MedicineDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of BiochemistryNational Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Hiroyuki Sugimoto
- Department of BiochemistryDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of PhysiologyKurume University School of Medicine, Kurume, Fukuoka 830-0011 JapanDepartment of Infection Control and Clinical Laboratory MedicineDokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, JapanDepartment of BiochemistryNational Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
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Exploring the impact of bariatric surgery on high density lipoprotein. Surg Obes Relat Dis 2015; 11:238-47. [DOI: 10.1016/j.soard.2014.07.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 07/14/2014] [Accepted: 07/16/2014] [Indexed: 01/06/2023]
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Acylated and unacylated ghrelin protect MC3T3-E1 cells against tert-butyl hydroperoxide-induced oxidative injury: pharmacological characterization of ghrelin receptor and possible epigenetic involvement. Amino Acids 2014; 46:1715-25. [PMID: 24705647 DOI: 10.1007/s00726-014-1734-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 03/21/2014] [Indexed: 01/02/2023]
Abstract
Increasing evidence suggests a role for oxidative stress in age-related decrease in osteoblast number and function leading to the development of osteoporosis. This study was undertaken to investigate whether ghrelin, previously reported to stimulate osteoblast proliferation, counteracts tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in MC3T3-E1 osteoblastic cells as well as to characterize the ghrelin receptor (GHS-R) involved in such activity. Pretreatment with ghrelin (10(-7)-10(-11)M) significantly increased viability and reduced apoptosis of MC3T3-E1 cells cultured with t-BHP (250 μM) for three hours at the low concentration of 10(-9)M as shown by MTT assay and Hoechst-33258 staining. Furthermore, ghrelin prevented t-BHP-induced osteoblastic dysfunction and changes in the cytoskeleton organization evidenced by the staining of the actin fibers with Phalloidin-FITC by reducing reactive oxygen species generation. The GHS-R type 1a agonist, EP1572 (10(-7)-10(-11)M), had no effect against t-BHP-induced cytotoxicity and pretreatment with the selective GHS-R1a antagonist, D-Lys(3)-GHRP-6 (10(-7)M), failed to remove ghrelin (10(-9) M)-protective effects against oxidative injury, indicating that GHS-R1a is not involved in such ghrelin activity. Accordingly, unacylated ghrelin (DAG), not binding GHS-R1a, displays the same protective actions of ghrelin against t-BHP-induced cytotoxicity. Preliminary observations indicate that ghrelin increased the trimethylation of lys4 on histones H3, a known epigenetic mark activator, which may regulate the expression of some genes limiting oxidative damage. In conclusion, our data demonstrate that ghrelin and DAG promote survival of MC3T3-E1 cell exposed to t-BHP-induced oxidative damage. Such effect is independent of GHS-R1a and is likely mediated by a common ghrelin/DAG binding site.
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de Oliveira C, Scarabelot VL, de Souza A, de Oliveira CM, Medeiros LF, de Macedo IC, Marques Filho PR, Cioato SG, Caumo W, Torres ILS. Obesity and chronic stress are able to desynchronize the temporal pattern of serum levels of leptin and triglycerides. Peptides 2014; 51:46-53. [PMID: 24184591 DOI: 10.1016/j.peptides.2013.10.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/21/2013] [Accepted: 10/21/2013] [Indexed: 12/20/2022]
Abstract
Disruption of the circadian system can lead to metabolic dysfunction as a response to environmental alterations. This study assessed the effects of the association between obesity and chronic stress on the temporal pattern of serum levels of adipogenic markers and corticosterone in rats. We evaluated weekly weight, delta weight, Lee index, and weight fractions of adipose tissue (mesenteric, MAT; subcutaneous, SAT; and pericardial, PAT) to control for hypercaloric diet-induced obesity model efficacy. Wistar rats were divided into four groups: standard chow (C), hypercaloric diet (HD), stress plus standard chow (S), and stress plus hypercaloric diet (SHD), and analyzed at three time points: ZT0, ZT12, and ZT18. Stressed animals were subjected to chronic stress for 1h per day, 5 days per week, during 80 days. The chronic exposure to a hypercaloric diet was an effective model for the induction of obesity and metabolic syndrome, increasing delta weight, Lee index, weight fractions of adipose tissue, and triglycerides and leptin levels. We confirmed the presence of a temporal pattern in the release of triglycerides, corticosterone, leptin, and adiponectin in naïve animals. Chronic stress reduced delta weight, MAT weight, and levels of triglycerides, total cholesterol, and leptin. There were interactions between chronic stress and obesity and serum total cholesterol levels, between time points and obesity and adiponectin and corticosterone levels, and between time points and chronic stress and serum leptin levels. In conclusion, both parameters were able to desynchronize the temporal pattern of leptin and triglyceride release, which could contribute to the development of metabolic diseases such as obesity and metabolic syndrome.
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Affiliation(s)
- Carla de Oliveira
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Vanessa Leal Scarabelot
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post Graduate Program in Biological Sciences - Physiology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil
| | - Andressa de Souza
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Laboratório de Bioquímica, Centro de Ciências Básicas da Saúde, Centro Universitário Univates, Lajeado, RS 95900-000, Brazil
| | - Cleverson Moraes de Oliveira
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Liciane Fernandes Medeiros
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post Graduate Program in Biological Sciences - Physiology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil
| | - Isabel Cristina de Macedo
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post Graduate Program in Biological Sciences - Physiology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil
| | - Paulo Ricardo Marques Filho
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Stefania Giotti Cioato
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Wolnei Caumo
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil
| | - Iraci L S Torres
- Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Department of Pharmacology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil; Post Graduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post Graduate Program in Biological Sciences - Physiology, Universidade Federal do Rio Grande do Sul Institute of Basic Health Sciences, Porto Alegre, RS 90050-170, Brazil.
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14
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Seim I, Jeffery PL, de Amorim L, Walpole CM, Fung J, Whiteside EJ, Lourie R, Herington AC, Chopin LK. Ghrelin O-acyltransferase (GOAT) is expressed in prostate cancer tissues and cell lines and expression is differentially regulated in vitro by ghrelin. Reprod Biol Endocrinol 2013; 11:70. [PMID: 23879975 PMCID: PMC3724588 DOI: 10.1186/1477-7827-11-70] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 07/05/2013] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Ghrelin is a 28 amino acid peptide hormone that is expressed in the stomach and a range of peripheral tissues, where it frequently acts as an autocrine/paracrine growth factor. Ghrelin is modified by a unique acylation required for it to activate its cognate receptor, the growth hormone secretagogue receptor (GHSR), which mediates many of the actions of ghrelin. Recently, the enzyme responsible for adding the fatty acid residue (octanoyl/acyl group) to the third amino acid of ghrelin, GOAT (ghrelin O-acyltransferase), was identified. METHODS We used cell culture, quantitative real-time reverse transcription (RT)-PCR and immunohistochemistry to demonstrate the expression of GOAT in prostate cancer cell lines and tissues from patients. Real-time RT-PCR was used to demonstrate the expression of prohormone convertase (PC)1/3, PC2 and furin in prostate cancer cell lines. Prostate-derived cell lines were treated with ghrelin and desacyl ghrelin and the effect on GOAT expression was measured using quantitative RT-PCR. RESULTS We have demonstrated that GOAT mRNA and protein are expressed in the normal prostate and human prostate cancer tissue samples. The RWPE-1 and RWPE-2 normal prostate-derived cell lines and the LNCaP, DU145, and PC3 prostate cancer cell lines express GOAT and at least one other enzyme that is necessary to produce mature, acylated ghrelin from proghrelin (PC1/3, PC2 or furin). Finally, ghrelin, but not desacyl ghrelin (unacylated ghrelin), can directly regulate the expression of GOAT in the RWPE-1 normal prostate derived cell line and the PC3 prostate cancer cell line. Ghrelin treatment (100nM) for 6 hours significantly decreased GOAT mRNA expression two-fold (P < 0.05) in the PC3 prostate cancer cell line, however, ghrelin did not regulate GOAT expression in the DU145 and LNCaP prostate cancer cell lines. CONCLUSIONS This study demonstrates that GOAT is expressed in prostate cancer specimens and cell lines. Ghrelin regulates GOAT expression, however, this is likely to be cell-type specific. The expression of GOAT in prostate cancer supports the hypothesis that the ghrelin axis has autocrine/paracrine roles. We propose that the RWPE-1 prostate cell line and the PC3 prostate cancer cell line may be useful for investigating GOAT regulation and function.
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Affiliation(s)
- Inge Seim
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
- Australian Prostate Cancer Research Centre, Queensland, Princess Alexandra Hospital, 199 Ipswich Road, Brisbane, Queensland, 4102, Australia
| | - Penny L Jeffery
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
- Australian Prostate Cancer Research Centre, Queensland, Princess Alexandra Hospital, 199 Ipswich Road, Brisbane, Queensland, 4102, Australia
- Mater Medical Research Institute, Mater Health Services, University of Queensland, South Brisbane, Queensland,, 4103, Australia
| | - Laura de Amorim
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
| | - Carina M Walpole
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
| | - Jenny Fung
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
| | - Eliza J Whiteside
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
| | - Rohan Lourie
- Mater Medical Research Institute, Mater Health Services, University of Queensland, South Brisbane, Queensland,, 4103, Australia
- Department of Pathology, Mater Health Services, South Brisbane, Queensland, 4103, Australia
| | - Adrian C Herington
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
- Australian Prostate Cancer Research Centre, Queensland, Princess Alexandra Hospital, 199 Ipswich Road, Brisbane, Queensland, 4102, Australia
| | - Lisa K Chopin
- Ghrelin Research Group, Translational Research Institute - Institute of Health and Biomedical Innovation, Queensland University of Technology, 37 Kent St, Woolloongabba, Queensland, 4102, Australia
- Australian Prostate Cancer Research Centre, Queensland, Princess Alexandra Hospital, 199 Ipswich Road, Brisbane, Queensland, 4102, Australia
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Seim I, Lubik AA, Lehman ML, Tomlinson N, Whiteside EJ, Herington AC, Nelson CC, Chopin LK. Cloning of a novel insulin-regulated ghrelin transcript in prostate cancer. J Mol Endocrinol 2013; 50:179-91. [PMID: 23267039 DOI: 10.1530/jme-12-0150] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ghrelin is a multifunctional hormone, with roles in stimulating appetite and regulating energy balance, insulin secretion and glucose homoeostasis. The ghrelin gene locus (GHRL) is highly complex and gives rise to a range of novel transcripts derived from alternative first exons and internally spliced exons. The wild-type transcript encodes a 117 amino acid preprohormone that is processed to yield the 28 amino acid peptide ghrelin. Here, we identified insulin-responsive transcription corresponding to cryptic exons in intron 2 of the human ghrelin gene. A transcript, termed in2c-ghrelin (intron 2-cryptic), was cloned from the testis and the LNCaP prostate cancer cell line. This transcript may encode an 83 amino acid preproghrelin isoform that codes for ghrelin, but not obestatin. It is expressed in a limited number of normal tissues and in tumours of the prostate, testis, breast and ovary. Finally, we confirmed that in2c-ghrelin transcript expression, as well as the recently described in1-ghrelin transcript, is significantly upregulated by insulin in cultured prostate cancer cells. Metabolic syndrome and hyperinsulinaemia have been associated with prostate cancer risk and progression. This may be particularly significant after androgen deprivation therapy for prostate cancer, which induces hyperinsulinaemia, and this could contribute to castrate-resistant prostate cancer growth. We have previously demonstrated that ghrelin stimulates prostate cancer cell line proliferation in vitro. This study is the first description of insulin regulation of a ghrelin transcript in cancer and should provide further impetus for studies into the expression, regulation and function of ghrelin gene products.
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Affiliation(s)
- Inge Seim
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Kelvin Grove, Brisbane, Queensland 4059, Australia
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Chopin LK, Seim I, Walpole CM, Herington AC. The ghrelin axis--does it have an appetite for cancer progression? Endocr Rev 2012; 33:849-91. [PMID: 22826465 DOI: 10.1210/er.2011-1007] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHSR), is a peptide hormone with diverse physiological roles. Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems. Ghrelin and the GHSR are expressed in a wide range of normal and tumor tissues, and a fluorescein-labeled, truncated form of ghrelin is showing promise as a biomarker for prostate cancer. Plasma ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a biomarker for cancer, but may be useful as a marker for cancer cachexia. Some single nucleotide polymorphisms in the ghrelin and GHSR genes have shown associations with cancer risk; however, larger studies are required. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, inflammation, and angiogenesis; however, the role of ghrelin in cancer is currently unclear. Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against cancer-related inflammation. Ghrelin and its analogs show promise as treatments for cancer-related cachexia. Further studies using in vivo models are required to determine whether ghrelin has a role in cancer progression.
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Affiliation(s)
- Lisa K Chopin
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Queensland University of Technology and Australian Prostate Cancer Research Centre-Queensland, Brisbane, Queensland 4001, Australia.
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17
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Pharmacological characterization of the ghrelin receptor mediating its inhibitory action on inflammatory pain in rats. Amino Acids 2012; 43:1751-9. [PMID: 22407485 PMCID: PMC3448055 DOI: 10.1007/s00726-012-1260-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 02/25/2012] [Indexed: 01/23/2023]
Abstract
Recent research suggests a role for ghrelin in the modulation of inflammatory disorders. However, the type of ghrelin receptor (GHS-R) involved in both the anti-inflammatory and anti-hyperalgesic actions of ghrelin remains to be characterized. In this study, we examined whether the inhibitory effect of ghrelin in the development of hyperalgesia and edema induced by intraplantar carrageenan administration depends on an interaction with GHS-R1a. Both central (1 nmol/rat, i.c.v.) and peripheral (40 nmol/kg, i.p.) administration of the selective GHS-R1a agonist EP1572 had no effect on carrageenan-induced hyperalgesia measured by Randall-Selitto test and paw edema. Furthermore, pre-treatment with the selective GHS-R1a antagonist, D-lys(3)-GHRP-6 (3 nmol/rat, i.c.v.) failed to prevent the anti-hyperalgesic and anti-inflammatory effects exerted by central ghrelin administration (1 nmol/rat), thus indicating that the type 1a GHS-R is not involved in these peptide activities. Accordingly, both central (1 and 2 nmol/rat, i.c.v.) and peripheral (40 and 80 nmol/kg, i.p.) administration of desacyl-ghrelin (DAG), which did not bind GHS-R1a, induced a significant reduction of the hyperalgesic and edematous activities of carrageenan. In conclusion, we have shown for the first time that DAG shares with ghrelin an inhibitory role in the development of hyperalgesia, as well as the paw edema induced by carrageenan and that a ghrelin receptor different from type 1a is involved in the anti-inflammatory activities of the peptide.
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18
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Morozumi N, Sato S, Yoshida S, Yamaki A, Furuya M, Inomata N, Ohnuma N, Minamitake Y, Ohsuye K, Kangawa K. A new strategy for metabolic stabilization of motilin using the C-terminal part of ghrelin. Peptides 2012; 33:279-84. [PMID: 22286034 DOI: 10.1016/j.peptides.2012.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 01/11/2012] [Accepted: 01/11/2012] [Indexed: 11/23/2022]
Abstract
Ghrelin consists of 28 amino acid residues with an octanoyl modification at the third serine residue. Recently we have found that the C-terminal part of ghrelin protects the ester bond of 3-octanoyled serine from plasma esterases and plays the essential role to prolong the plasma half-life and to show its biological activity in vivo. In the present study, we researched whether the C-terminal part of ghrelin has a potential to prolong the plasma half-life of motilin, by comparing the pharmacokinetics of various chimeric peptides of ghrelin and motilin. Motilin is another gastro-intestinal peptide hormone related with ghrelin structurally, binding to the same family of G protein-coupled receptors. Chimeric peptides were designed to be composed of motilin(1-12) fragment, the active core binding to the motilin receptor, GPR38, and C-terminal part of ghrelin. The modification of motilin(1-12) fragment by C-terminal part of ghrelin hardly influenced its agonist activity to GPR38 and almost all these chimeric peptides showed more than two times longer plasma half-lives than motilin in rats. From the relationship between structures of chimeric peptides and their corresponding plasma half-lives, the mid-region of ghrelin rich in basic amino acids ((15)RKESKK(20)) was considered to be the most important in prolonging the plasma half-life of motilin. The deletion of these fragments or replacement of 17th glutamic acid with a neutral amino acid resulted in short plasma half-lives. In conclusion, our data suggested that the C-terminal part of ghrelin has a potential to improve the biokinetics of motilin probably by a metabolic stabilizing effect.
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Affiliation(s)
- Naomi Morozumi
- Faculty of Pharmacology I, Asubio Pharma Co, Ltd, 6-4-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
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Becker GF, Macedo RCO, Cunha GDS, Martins JB, Laitano O, Reischak-Oliveira A. Combined effects of aerobic exercise and high-carbohydrate meal on plasma acylated ghrelin and levels of hunger. Appl Physiol Nutr Metab 2012; 37:184-92. [DOI: 10.1139/h11-149] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study investigated the effect of an aerobic exercise bout associated with a high-carbohydrate (CHO) meal on plasma levels of acylated ghrelin and hunger sensation. Eight healthy males performed an exercise (ET) and a control (CT) trial. In ET, participants performed a 60-min cycling exercise (∼70% of maximal oxygen uptake) after consuming a high-CHO meal. In the CT, participants remained at rest throughout the whole period after consuming the high-CHO meal. Hunger sensation was assessed and blood samples were taken to determine the levels of acylated ghrelin, glucose, insulin, total cholesterol (TC), and triglycerides (TG). There was suppression of hunger after consuming the meal in ET and CT (p = 0.028 and p = 0.011, respectively). Hunger increased in CT in the period correspondent to the exercise session (p = 0.017) and remained suppressed in the ET. The area under the curve for acylated ghrelin showed that its levels were lower in the ET compared with CT in the period of the exercise plus the immediate period (1 h) postexercise (60.7 vs. 96.75 pg·mL–1·2 h–1, respectively; p = 0.04). Inverse correlations between acylated ghrelin levels and insulin, TC, and TG levels at different time points were observed. In conclusion, these findings suggest that 1 bout of aerobic exercise maintains the meal-induced suppression of hunger. The mechanism underlying this effect may involve the exercise-induced suppression of acylated ghrelin. These results implicate that the combination of a high-CHO meal and aerobic exercise may effectively improve appetite control and body weight management.
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Affiliation(s)
- Geórgia Franco Becker
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rodrigo Cauduro Oliveira Macedo
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Giovani dos Santos Cunha
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Jocelito Bijoldo Martins
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Orlando Laitano
- School of Physical Education, Federal University of Vale do São Francisco, Petrolina, PE, Brazil
| | - Alvaro Reischak-Oliveira
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
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20
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Satou M, Nakamura Y, Ando H, Sugimoto H. Understanding the functional significance of ghrelin processing and degradation. Peptides 2011; 32:2183-90. [PMID: 21763742 DOI: 10.1016/j.peptides.2011.06.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 06/08/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
Post-translational modification, cleavage and processing of circulating hormones are common themes in the control of hormone activities. Full-length ghrelin is a 28 amino acid protein that exists in several modified and processed forms, including addition of an acyl moiety at the third serine of the N-terminus. When modified with octanoic acid, the first five N-terminal residues of ghrelin can modulate a signaling pathway via the ghrelin receptor GHSR1a. Although modification via a lipid moiety is essential for binding and activation of GHSR1a by ghrelin, many reports suggest that a desacyl form of ghrelin exists and has synergistic, opposing and distinct properties as compared to the acyl form. Therefore, it is important to clarify the physiological relevance of ghrelin derivatives. Based on lines of evidence from various studies, we propose that a larger proportion of secreted ghrelin is present in the deacylated form and furthermore, that circulating acyl and desacyl forms of ghrelin may be hydrolyzed to form short peptide fragments. Here, we summarize the results of studies aimed at understanding ghrelin processing and its implications for physiological function, as well as our recent findings regarding enzymes in the blood capable of generating processed forms of ghrelin.
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Affiliation(s)
- Motoyasu Satou
- Departments of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
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21
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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: 20] [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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22
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Seim I, Josh P, Cunningham P, Herington A, Chopin L. Ghrelin axis genes, peptides and receptors: recent findings and future challenges. Mol Cell Endocrinol 2011; 340:3-9. [PMID: 21616122 DOI: 10.1016/j.mce.2011.05.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 05/04/2011] [Accepted: 05/09/2011] [Indexed: 12/15/2022]
Abstract
The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come.
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Affiliation(s)
- Inge Seim
- Queensland University of Technology, Brisbane, Queensland, Australia
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Prodam F, Trovato L, Demarchi I, Busti A, Petri A, Moia S, Walker GE, Aimaretti G, Bona G, Bellone S. Unacylated, acylated ghrelin and obestatin levels are differently inhibited by oral glucose load in pediatric obesity: Association with insulin sensitivity and metabolic alterations. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.eclnm.2011.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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24
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Diet-induced obesity suppresses ghrelin in rat gastrointestinal tract and serum. Mol Cell Biochem 2011; 355:299-308. [DOI: 10.1007/s11010-011-0867-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 04/28/2011] [Indexed: 12/14/2022]
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Current world literature. Curr Opin Endocrinol Diabetes Obes 2011; 18:83-98. [PMID: 21178692 DOI: 10.1097/med.0b013e3283432fa7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ochner CN, Gibson C, Shanik M, Goel V, Geliebter A. Changes in neurohormonal gut peptides following bariatric surgery. Int J Obes (Lond) 2010; 35:153-66. [PMID: 20625384 DOI: 10.1038/ijo.2010.132] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The rising prevalence of obesity has reached pandemic proportions, with an associated cost estimated at up to 7% of health expenditures worldwide. Bariatric surgery is currently the only effective long-term treatment for obesity and obesity-related co-morbidities in clinically severely obese patients. However, the precise physiological mechanisms underlying the postsurgical reductions in caloric intake and body weight are poorly comprehended. It has been suggested that changes in hormones involved in hunger, food intake and satiety via the neurohormonal network may contribute to the efficacy of bariatric procedures. In this review, we consider how gastrointestinal hormone concentrations, involved in appetite and body weight regulation via the gut-brain axis, are altered by different bariatric procedures. Special emphasis is placed on neurohormonal changes following Roux-en-Y gastric bypass surgery, which is the most common and effective procedure used today.
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Affiliation(s)
- C N Ochner
- New York Obesity Research Center, Department of Medicine, St Luke's-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, NY 10025, USA.
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