1
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Wang L, Chen Q, Pang J. The effects and mechanisms of ghrelin upon angiogenesis in human coronary artery endothelial cells under hypoxia. Peptides 2023; 160:170921. [PMID: 36496009 DOI: 10.1016/j.peptides.2022.170921] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022]
Abstract
Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor (GHSR), has been found to stimulate angiogenesis both in vivo and in vitro. However, the effect of ghrelin upon angiogenesis, and the corresponding mechanisms of ghrelin therein, in human coronary artery endothelial cells (HCAECs) under hypoxia is still unknown. Our study found that ghrelin significantly increased HCAECs proliferation, migration, in vitro angiogenesis, and microvessel sprouting from the aortic ring under hypoxic conditions. The ghrelin-induced angiogenic process was accompanied by vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2) and endothelial-specific receptor tyrosine kinase (Tie2) expressions. In addition, this angiogenic effect was almost completely inhibited by Ang-2 RNAi and Tie2 RNAi. Pretreatment with the GHSR1a blocker [D-Lys3]-GHRP-6 abolished ghrelin-induced VEGF, Ang-1, Ang-2 and Tie2 expressions and in vitro angiogenesis. In conclusion, this is the first demonstration that ghrelin stimulates HCAECs in vitro angiogenesis through GHSR1a-mediated VEGF, Ang-1, Ang-2 and Tie2 pathways under hypoxic conditions. It indicated that ghrelin might play an important role in myocardial angiogenesis after ischemic injury.
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Affiliation(s)
- Li Wang
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
| | - Qingwei Chen
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Jun Pang
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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2
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Effect of Ghrelin on the Cardiovascular System. BIOLOGY 2022; 11:biology11081190. [PMID: 36009817 PMCID: PMC9405061 DOI: 10.3390/biology11081190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/19/2022]
Abstract
Simple Summary Ghrelin is an octanoylated peptide that was initially isolated from rat and human stomachs in the process of searching for an endogenous ligand to the orphan growth hormone secretagogue receptor (GHS-R), a G-protein-coupled receptor. Exogenous or endogenous ghrelin secreted from the stomach binds to GHS-R on gastric vagal nerve terminals, and the signals are transmitted to the central nervous system via the vagal afferent nerve to facilitate growth hormone (GH) secretion, feeding, sympathetic inhibition, parasympathetic activation, and anabolic effects. Ghrelin also binds directly to the pituitary GHS-R and stimulates GH secretion. Ghrelin has beneficial effects on the cardiovascular system, including cardioprotective effects such as anti-heart failure, anti-arrhythmic, and anti-inflammatory actions, and it enhances vascular activity via GHS-R-dependent stimulation of GH/IGF-1 (insulin-like growth factor-1) and modulation of the autonomic nervous system. The anti-heart failure effects of ghrelin could be useful as a new therapeutic strategy for chronic heart failure. Abstract Ghrelin, an n-octanoyl-modified 28-amino-acid-peptide, was first discovered in the human and rat stomach as an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). Ghrelin-GHS-R1a signaling regulates feeding behavior and energy balance, promotes vascular activity and angiogenesis, improves arrhythmia and heart failure, and also protects against cardiovascular disease by suppressing cardiac remodeling after myocardial infarction. Ghrelin’s cardiovascular protective effects are mediated by the suppression of sympathetic activity; activation of parasympathetic activity; alleviation of vascular endothelial dysfunction; and regulation of inflammation, apoptosis, and autophagy. The physiological functions of ghrelin should be clarified to determine its pharmacological potential as a cardiovascular medication.
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3
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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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4
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Hexarelin modulates lung mechanics, inflammation, and fibrosis in acute lung injury. Drug Target Insights 2021; 15:26-33. [PMID: 34871336 PMCID: PMC8638068 DOI: 10.33393/dti.2021.2347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/20/2021] [Indexed: 12/27/2022] Open
Abstract
Introduction: Acute respiratory distress syndrome (ARDS) is an acute form of diffuse lung injury characterized by (i) an intense inflammatory response, (ii) increased pulmonary vascular permeability, and (iii) the loss of respiratory pulmonary tissue. In this article we explore the therapeutic potential of hexarelin, a synthetic hexapeptide growth hormone secretagogue (GHS), in an experimental model of ARDS. Hexarelin has anti-inflammatory properties and demonstrates cardiovascular-protective activities including the inhibition of cardiomyocyte apoptosis and cardiac fibrosis, both of which may involve the angiotensin-converting enzyme (ACE) system. Methods: In our experimental model, ARDS was induced by the instillation of 100 mM HCl into the right bronchus; these mice were treated with hexarelin (320 μg/kg, ip) before (Pre) or after (Post) HCl challenge, or with vehicle. Respiratory system compliance, blood gas analysis, and differential cell counts in a selective bronchoalveolar lavage (BAL) were determined 6 or 24 hours after HCl instillation. In an extended study, mice were observed for a subsequent 14 days in order to assess lung fibrosis. Results: Hexarelin induced a significant improvement in lung compliance and a reduction of the number of total immune cells in BAL 24 hours after HCl instillation, accompanied with a lower recruitment of neutrophils compared with the vehicle group. At day 14, hexarelin-treated mice presented with less pulmonary collagen deposition compared with vehicle-treated controls. Conclusions: Our data suggest that hexarelin can inhibit the early phase of the inflammatory response in a murine model of HCl-induced ARDS, thereby blunting lung remodeling processes and fibrotic development.
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5
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Nakanishi Y, Higuchi J, Honda N, Komura N. [Pharmacological profile and clinical efficacy of anamorelin HCl (ADLUMIZ ®Tablets), the first orally available drug for cancer cachexia with ghrelin-like action in Japan]. Nihon Yakurigaku Zasshi 2021; 156:370-381. [PMID: 34719572 DOI: 10.1254/fpj.21046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Anamorelin hydrochloride (hereinafter referred to as anamorelin) is an orally active, small-molecule drug with a similar pharmacological action to ghrelin, an endogenous ligand of growth hormone secretagogue receptor type 1a (GHS-R1a). It was first approved in Japan for the treatment of cancer cachexia, characterized by weight loss and anorexia. Anamorelin stimulated the secretion of growth hormone (GH) from cultured rat pituitary cells and increased plasma GH levels by oral administration to rats, pigs and humans. When anamorelin was orally administered once daily for 6 days to rats, larger body weight gain associated with increased food consumption compared to the control group was observed from after the first dose. Anamorelin is a selective agonist for GHS-R1a and enhanced GHS-R1a-mediated pituitary GH secretion and increased food consumption, resulting in body weight gain. In the two Japanese phase II studies in patients with cancer cachexia associated with non-small cell lung cancer (NSCLC), improvement of lean body mass (LBM) and body weight losses and anorexia were demonstrated. The tumor types of target patients in the Japanese phase III study were colorectal, gastric, and pancreatic cancer. As a result, maintenance and increase of LBM and body weight as well as improvement of anorexia were observed, and the efficacy against cancer cachexia associated with colorectal, gastric, and pancreatic cancer was confirmed. There were no observed events considered to be significant safety risks. In conclusion, anamorelin is expected to provide a new therapeutic option for cancer cachexia for which no effective treatment has been available.
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Affiliation(s)
- Yasutomo Nakanishi
- Discovery & Research, Research Center of Specialty, Ono Pharmaceutical Co., Ltd
| | - Junya Higuchi
- Discovery & Research, Research promotion, Ono Pharmaceutical Co., Ltd
| | | | - Naoyuki Komura
- Clinical Development, Clinical Development Planning II, Ono Pharmaceutical Co., Ltd
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6
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Reich N, Hölscher C. Acylated Ghrelin as a Multi-Targeted Therapy for Alzheimer's and Parkinson's Disease. Front Neurosci 2020; 14:614828. [PMID: 33381011 PMCID: PMC7767977 DOI: 10.3389/fnins.2020.614828] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/27/2020] [Indexed: 12/13/2022] Open
Abstract
Much thought has been given to the impact of Amyloid Beta, Tau and Alpha-Synuclein in the development of Alzheimer's disease (AD) and Parkinson's disease (PD), yet the clinical failures of the recent decades indicate that there are further pathological mechanisms at work. Indeed, besides amyloids, AD and PD are characterized by the culminative interplay of oxidative stress, mitochondrial dysfunction and hyperfission, defective autophagy and mitophagy, systemic inflammation, BBB and vascular damage, demyelination, cerebral insulin resistance, the loss of dopamine production in PD, impaired neurogenesis and, of course, widespread axonal, synaptic and neuronal degeneration that leads to cognitive and motor impediments. Interestingly, the acylated form of the hormone ghrelin has shown the potential to ameliorate the latter pathologic changes, although some studies indicate a few complications that need to be considered in the long-term administration of the hormone. As such, this review will illustrate the wide-ranging neuroprotective properties of acylated ghrelin and critically evaluate the hormone's therapeutic benefits for the treatment of AD and PD.
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Affiliation(s)
- Niklas Reich
- Biomedical & Life Sciences Division, Lancaster University, Lancaster, United Kingdom
| | - Christian Hölscher
- Neurology Department, A Second Hospital, Shanxi Medical University, Taiyuan, China.,Research and Experimental Center, Henan University of Chinese Medicine, Zhengzhou, China
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7
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Regional Differences in the Ghrelin-Growth Hormone Secretagogue Receptor Signalling System in Human Heart Disease. CJC Open 2020; 3:182-194. [PMID: 33644732 PMCID: PMC7893201 DOI: 10.1016/j.cjco.2020.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Background The hormone ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR) are expressed in myocardium. GHSR binding activates signalling pathways coupled to cardiomyocyte survival and contractility. These properties have made the ghrelin-GHSR axis a candidate for a biomarker of cardiac function. The dynamics of ghrelin-GHSR are altered significantly in late stages of heart failure (HF) and cardiomyopathy, when left ventricular (LV) function is failing. We examined the relationship of GHSR with ghrelin in cardiac tissue from patients with valvular disease with no detectable changes in LV function. Methods Biopsy samples from the left ventricle and left atrium were obtained from 25 patients with valvular disease (of whom 13 also had coronary artery disease) and preserved LV ejection fraction, and compared to control samples obtained via autopsy. Using quantitative confocal fluorescence microscopy, levels of GHSR were determined using [Dpr3(n-octanoyl),Lys19(sulfo-Cy5)]ghrelin(1-19), and immunofluorescence determined ghrelin, the heart failure marker natriuretic peptide type-B (BNP), and contractility marker sarcoplasmic reticulum ATPase pump (SERCA2a). Results A positive correlation between GHSR and ghrelin was apparent in only diseased tissue. Ghrelin and BNP significantly correlated in the left ventricle and strongly colocalized to the same intracellular compartment in diseased and control tissue. GHSR, ghrelin, and BNP all strongly and significantly correlated with SERCA2a in the left ventricle of diseased tissue only. Conclusions Our results suggest that the dynamics of the myocardial ghrelin-GHSR axis is altered in cardiovascular disease in the absence of measurable changes in heart function, and might accompany a regional shift in endocrine programming.
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8
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Cervone DT, Lovell AJ, Dyck DJ. Regulation of adipose tissue and skeletal muscle substrate metabolism by the stomach-derived hormone, ghrelin. Curr Opin Pharmacol 2020; 52:25-32. [DOI: 10.1016/j.coph.2020.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/08/2020] [Accepted: 04/08/2020] [Indexed: 12/17/2022]
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9
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Danila GM, Puiu M, Zamfir LG, Bala C. Early Detection of Growth Hormone Secretagogue Receptor Antagonists Exploiting Their Atypical Behavior in Competitive Assays. Anal Chem 2019; 91:14812-14817. [PMID: 31702907 DOI: 10.1021/acs.analchem.9b03845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the proof-of-concept of a bioaffinity format designed for the early detection of growth hormone secretagogue receptor (GHS-R1a) antagonists in urine samples. We exploit here their atypical behavior in competitive experiments with labeled ghrelin (GHR), namely, the strong promoting effect on the GHR/GHS-R1a interaction at low molar ratios GHR/antagonist. The antagonists potentiate the GHR/GHS-R1a interaction, and they display the same effect on the interaction of GHS-R1a with other agonists listed as doping agents. The developed assay allows the estimation of affinity constants of ligand/receptor and antagonist/receptor binding and is amenable to optical, electrochemical, and mass-sensitive detection. The estimated affinity constants for GHR/GHS-R1a and antagonist/GHS-R1a in the absence of G proteins are in good agreement with recently reported data.
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Affiliation(s)
- George Madalin Danila
- Laboratory for Quality Control and Process Monitoring , University of Bucharest , 030018 Bucharest , Romania.,Romanian Doping Control Laboratory , 022103 Bucharest , Romania
| | - Mihaela Puiu
- Laboratory for Quality Control and Process Monitoring , University of Bucharest , 030018 Bucharest , Romania
| | - Lucian-Gabriel Zamfir
- Laboratory for Quality Control and Process Monitoring , University of Bucharest , 030018 Bucharest , Romania.,ICUB , University of Bucharest , 050107 Bucharest , Romania
| | - Camelia Bala
- Laboratory for Quality Control and Process Monitoring , University of Bucharest , 030018 Bucharest , Romania.,Department of Analytical Chemistry , University of Bucharest , 030018 Bucharest , Romania
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10
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Oliveira MC, Correia JDG. Biomedical applications of radioiodinated peptides. Eur J Med Chem 2019; 179:56-77. [PMID: 31238251 DOI: 10.1016/j.ejmech.2019.06.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 02/08/2023]
Abstract
The overexpression of peptide receptors in certain tumors as compared to endogeneous expression levels represents the molecular basis for the design of peptide-based tools for targeted nuclear imaging and therapy. Receptor targeting with radiolabelled peptides became a very important imaging and/or therapeutic approach in nuclear medicine and oncology. A great variety of peptides has been radiolabelled with clinical relevant radionuclides, such as radiometals and radiohalogens. However, to the best of our knowledge concise and updated reviews providing information about the biomedical application of radioiodinated peptides are still missing. This review outlines the synthetic efforts in the preparation of radioiodinated peptides highlighting the importance of radioiodine in nuclear medicine, giving an overview of the most relevant radioiodination strategies that have been employed and describes relevant examples of their use in the biomedical field.
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Affiliation(s)
- Maria Cristina Oliveira
- Centro de Ciências e Tecnologias Nucleares, Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal.
| | - João D G Correia
- Centro de Ciências e Tecnologias Nucleares, Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal.
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11
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TOKUDOME T, KANGAWA K. Physiological significance of ghrelin in the cardiovascular system. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2019; 95:459-467. [PMID: 31611501 PMCID: PMC6819151 DOI: 10.2183/pjab.95.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 06/10/2019] [Indexed: 06/01/2023]
Abstract
Ghrelin, a growth hormone-releasing peptide first discovered in rat stomach in 1999, is a ligand for the growth hormone secretagogue receptor. It participates in the regulation of diverse processes, including energy balance and body weight maintenance, and appears to be beneficial for the treatment of cardiovascular diseases. In animal models of chronic heart failure, ghrelin improves cardiac function and remodeling; these findings have been recapitulated in human patients. In other animal models, ghrelin effectively diminishes pulmonary hypertension. Moreover, ghrelin administration early after myocardial infarction decreased the frequency of fatal arrhythmia and improved survival rate. In ghrelin-deficient mice, endogenous ghrelin protects against fatal arrhythmia and promotes remodeling after myocardial infarction. Although the mechanisms underlying the effects of ghrelin on the cardiovascular system have not been fully elucidated, its beneficial effects appear to be mediated through regulation of the autonomic nervous system. Ghrelin is a promising therapeutic agent for cardiac diseases.
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Affiliation(s)
- Takeshi TOKUDOME
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Kenji KANGAWA
- National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
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12
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Tokudome T, Otani K, Miyazato M, Kangawa K. Ghrelin and the heart. Peptides 2019; 111:42-46. [PMID: 29791869 DOI: 10.1016/j.peptides.2018.05.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/11/2018] [Accepted: 05/15/2018] [Indexed: 12/14/2022]
Abstract
Ghrelin, a growth hormone-releasing peptide that was first discovered in the stomach of rats in 1999, is an endogenous ligand of growth hormone secretagogue receptor. Ghrelin exerts its potent growth hormone-releasing and orexigenic activities by binding to specific receptors in the brain. Subsequent studies showed that ghrelin participates in the regulation of diverse processes, including energy balance, body weight maintenance, and glucose and fat metabolism, and demonstrated that ghrelin is beneficial for treatment of cardiac diseases. In animal models of chronic heart failure, administration of ghrelin improves cardiac function and remodeling, and these findings were recapitulated in human patients with heart failure. Also in animal models, ghrelin administration effectively diminishes pulmonary hypertension induced by monocrotaline or chronic hypoxia. In addition, repeated administration of ghrelin to cachectic chronic obstructive pulmonary disease patients has positive effects on body composition, including amelioration of muscle wasting, improvement of functional capacity, and sympathetic activity. Moreover, administration of ghrelin early after myocardial infarction decreases the frequency of fatal arrhythmia and improved the survival rate. In ghrelin-deficient mice, both exogenous and endogenous ghrelin protects against fatal arrhythmia and promotes remodeling after myocardial infarction. Although the mechanisms underlying the effects of ghrelin on the cardiovascular system have not been fully elucidated, some evidence suggests that its beneficial effects are mediated through both direct actions on cardiovascular cells and regulation of autonomic nervous system activity. Therefore, ghrelin is a promising novel therapeutic agent for cardiac disease.
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Affiliation(s)
- Takeshi Tokudome
- Department of Biochemistry (T.T, M.M), Regenerative Medicine and Tissue Engineering (K.O), and Trustee (K.K), National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - Kentaro Otani
- Department of Biochemistry (T.T, M.M), Regenerative Medicine and Tissue Engineering (K.O), and Trustee (K.K), National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Mikiya Miyazato
- Department of Biochemistry (T.T, M.M), Regenerative Medicine and Tissue Engineering (K.O), and Trustee (K.K), National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Kenji Kangawa
- Department of Biochemistry (T.T, M.M), Regenerative Medicine and Tissue Engineering (K.O), and Trustee (K.K), National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
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13
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Less Exploited GPCRs in Precision Medicine: Targets for Molecular Imaging and Theranostics. Molecules 2018; 24:molecules24010049. [PMID: 30583594 PMCID: PMC6337414 DOI: 10.3390/molecules24010049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/07/2018] [Accepted: 12/09/2018] [Indexed: 12/18/2022] Open
Abstract
Precision medicine relies on individually tailored therapeutic intervention taking into account individual variability. It is strongly dependent on the availability of target-specific drugs and/or imaging agents that recognize molecular targets and patient-specific disease mechanisms. The most sensitive molecular imaging modalities, Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), rely on the interaction between an imaging radioprobe and a target. Moreover, the use of target-specific molecular tools for both diagnostics and therapy, theranostic agents, represent an established methodology in nuclear medicine that is assuming an increasingly important role in precision medicine. The design of innovative imaging and/or theranostic agents is key for further accomplishments in the field. G-protein-coupled receptors (GPCRs), apart from being highly relevant drug targets, have also been largely exploited as molecular targets for non-invasive imaging and/or systemic radiotherapy of various diseases. Herein, we will discuss recent efforts towards the development of innovative imaging and/or theranostic agents targeting selected emergent GPCRs, namely the Frizzled receptor (FZD), Ghrelin receptor (GHSR-1a), G protein-coupled estrogen receptor (GPER), and Sphingosine-1-phosphate receptor (S1PR). The pharmacological and clinical relevance will be highlighted, giving particular attention to the studies on the synthesis and characterization of targeted molecular imaging agents, biological evaluation, and potential clinical applications in oncology and non-oncology diseases. Whenever relevant, supporting computational studies will be also discussed.
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14
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Abbas A, Yu L, Lalonde T, Wu D, Thiessen JD, Luyt LG, Dhanvantari S. Development and Characterization of an 18F-labeled Ghrelin Peptidomimetic for Imaging the Cardiac Growth Hormone Secretagogue Receptor. Mol Imaging 2018; 17:1536012118809587. [PMID: 30394854 PMCID: PMC6236854 DOI: 10.1177/1536012118809587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
One-third of patients with heart disease develop heart failure, which is diagnosed
through imaging and detection of circulating biomarkers. Imaging strategies reveal
morphologic and functional changes but fall short of detecting molecular abnormalities
that can lead to heart failure, and circulating biomarkers are not cardiac specific. Thus,
there is critical need for biomarkers that are endogenous to myocardial tissues. The
cardiac growth hormone secretagogue receptor 1a (GHSR1a), which binds the hormone ghrelin,
is a potential biomarker for heart failure. We have synthesized and characterized a novel
ghrelin peptidomimetic tracer, an 18F-labeled analogue of G-7039, for positron
emission tomography (PET) imaging of cardiac GHSR1a. In vitro analysis showed enhanced
serum stability compared to natural ghrelin and significantly increased cellular uptake in
GHSR1a-expressing OVCAR cells. Biodistribution studies in mice showed that tissue uptake
of the tracer was independent of circulating ghrelin levels, and there was negligible
cardiac uptake and high uptake in the liver, intestines, and kidneys. Specificity of
tracer uptake was assessed using ghsr −/− mice; both static and dynamic PET imaging revealed no difference in cardiac
uptake, and there was no significant correlation between cardiac standardized uptake
values and GHSR1a expression. Our study lays the groundwork for further refinement of
peptidomimetic PET tracers targeting cardiac GHSR1a.
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Affiliation(s)
- Ahmed Abbas
- 1 Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Lihai Yu
- 2 Department of Chemistry, Western University, London, Ontario, Canada
| | - Tyler Lalonde
- 2 Department of Chemistry, Western University, London, Ontario, Canada
| | - Derek Wu
- 3 Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Jonathan D Thiessen
- 1 Department of Medical Biophysics, Western University, London, Ontario, Canada.,4 Imaging Research, Lawson Health Research Institute, London, Ontario, Canada
| | - Leonard G Luyt
- 2 Department of Chemistry, Western University, London, Ontario, Canada.,4 Imaging Research, Lawson Health Research Institute, London, Ontario, Canada.,5 Department of oncology, Western University, London, Ontario, Canada
| | - Savita Dhanvantari
- 1 Department of Medical Biophysics, Western University, London, Ontario, Canada.,3 Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada.,4 Imaging Research, Lawson Health Research Institute, London, Ontario, Canada.,6 Metabolism/Diabetes, Lawson Health Research Institute, London, Ontario, Canada
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15
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Fowkes MM, Lalonde T, Yu L, Dhanvantari S, Kovacs MS, Luyt LG. Peptidomimetic growth hormone secretagogue derivatives for positron emission tomography imaging of the ghrelin receptor. Eur J Med Chem 2018; 157:1500-1511. [PMID: 30282322 DOI: 10.1016/j.ejmech.2018.08.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 08/16/2018] [Accepted: 08/22/2018] [Indexed: 02/06/2023]
Abstract
The ghrelin receptor is a seven-transmembrane (7-TM) receptor known to have an increased level of expression in human carcinoma and heart failure. Recent work has focused on the synthesis of positron emission tomography (PET) probes designed to target and image this receptor for disease diagnosis and staging. However, these probes have been restricted to small-molecule quinalizonones and peptide derivatives of the endogenous ligand ghrelin. We describe the design, synthesis and biological evaluation of a series of 4-fluorobenzoylated growth hormone secretagogues (GHSs) derived from peptidic (GHRP-1, GHPR-2 and GHRP-6) and peptidomimetic (G-7039, [1-Nal4]G-7039 and ipamorelin) families in order to test locations for the insertion of fluorine-18 for PET imaging. The peptidomimetic G-7039 was found to be the most suitable for 18F-radiolabelling as its non-radioactive 4-fluorobenzoylated analogue ([1-Nal4,Lys5(4-FB)]G-7039), had both a high binding affinity (IC50 = 69 nM) and promising in vitro efficacy (EC50 = 1.1 nM). Prosthetic group radiolabelling of the precursor compound [1-Nal4]G-7039 using N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB) delivered the PET probe [1-Nal4,Lys5(4-[18F]-FB)]G-7039 in an average decay-corrected radiochemical yield of 48%, a radio-purity ≥ 99% and an average molar activity of >34 GBq/μmol. This compound could be investigated as a PET probe for the detection of diseases that are characterised by overexpression of the ghrelin receptor.
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Affiliation(s)
- Milan M Fowkes
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada
| | - Tyler Lalonde
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada
| | - Lihai Yu
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada
| | - Savita Dhanvantari
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada
| | - Michael S Kovacs
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada
| | - Leonard G Luyt
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada.
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16
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The CD36-PPARγ Pathway in Metabolic Disorders. Int J Mol Sci 2018; 19:ijms19051529. [PMID: 29883404 PMCID: PMC5983591 DOI: 10.3390/ijms19051529] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/08/2018] [Accepted: 05/16/2018] [Indexed: 12/21/2022] Open
Abstract
Uncovering the biological role of nuclear receptor peroxisome proliferator-activated receptors (PPARs) has greatly advanced our knowledge of the transcriptional control of glucose and energy metabolism. As such, pharmacological activation of PPARγ has emerged as an efficient approach for treating metabolic disorders with the current use of thiazolidinediones to improve insulin resistance in diabetic patients. The recent identification of growth hormone releasing peptides (GHRP) as potent inducers of PPARγ through activation of the scavenger receptor CD36 has defined a novel alternative to regulate essential aspects of lipid and energy metabolism. Recent advances on the emerging role of CD36 and GHRP hexarelin in regulating PPARγ downstream actions with benefits on atherosclerosis, hepatic cholesterol biosynthesis and fat mitochondrial biogenesis are summarized here. The response of PPARγ coactivator PGC-1 is also discussed in these effects. The identification of the GHRP-CD36-PPARγ pathway in controlling various tissue metabolic functions provides an interesting option for metabolic disorders.
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17
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Exploring the Behavioral and Metabolic Phenotype Generated by Re-Introduction of the Ghrelin Receptor in the Ventral Tegmental Area. Int J Mol Sci 2017; 18:ijms18050914. [PMID: 28445429 PMCID: PMC5454827 DOI: 10.3390/ijms18050914] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/01/2017] [Accepted: 04/20/2017] [Indexed: 11/16/2022] Open
Abstract
Ghrelin receptor (Ghr-R) signaling in neurons of the ventral tegmental area (VTA) can modulate dopaminergic function and the reward-related effects of both palatable foods and drugs of abuse. In this study, we re-introduced the Ghr-R in VTA neurons in Ghr-R knockout mice (Ghr-RVTA mice) to specifically study the importance of the constitutively active Ghr-R for VTA neuronal signaling. Our results showed that re-introduction of the Ghr-R in the VTA had no impact on body weight or food intake under basal conditions. However, during novel environment stress Ghr-RVTA mice showed increased food intake and energy expenditure compared to Ghr-R knockout mice, demonstrating the significance of Ghr-R signaling in the response to stress. Ghr-RVTA mice also showed increased cocaine-induced locomotor activity compared to Ghr-R knockout mice, highlighting the importance of ghrelin signaling for the reward-related effects of activation of VTA neurons. Overall, our data suggest that re-introduction of the Ghr-R in the mesolimbic reward system of Ghr-R knockout mice increases the level of activation induced by both cocaine and novelty stress.
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18
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Moldovan RP, Els-Heindl S, Worm DJ, Kniess T, Kluge M, Beck-Sickinger AG, Deuther-Conrad W, Krügel U, Brust P. Development of Fluorinated Non-Peptidic Ghrelin Receptor Ligands for Potential Use in Molecular Imaging. Int J Mol Sci 2017; 18:ijms18040768. [PMID: 28379199 PMCID: PMC5412352 DOI: 10.3390/ijms18040768] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/23/2017] [Accepted: 03/31/2017] [Indexed: 12/19/2022] Open
Abstract
The ghrelin receptor (GhrR) is a widely investigated target in several diseases. However, the current knowledge of its role and distribution in the brain is limited. Recently, the small and non-peptidic compound (S)-6-(4-bromo-2-fluorophenoxy)-3-((1-isopropylpiperidin-3-yl)methyl)-2-methylpyrido[3,2-d]pyrimidin-4(3H)-one ((S)-9) has been described as a GhrR ligand with high binding affinity. Here, we describe the synthesis of fluorinated derivatives, the in vitro evaluation of their potency as partial agonists and selectivity at GhrRs, and their physicochemical properties. These results identified compounds (S)-9, (R)-9, and (S)-16 as suitable parent molecules for 18F-labeled positron emission tomography (PET) radiotracers to enable future investigation of GhrR in the brain.
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Affiliation(s)
- Rareş-Petru Moldovan
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
| | - Sylvia Els-Heindl
- Institute of Biochemistry, Universität Leipzig, 04103 Leipzig, Germany.
| | - Dennis J Worm
- Institute of Biochemistry, Universität Leipzig, 04103 Leipzig, Germany.
| | - Torsten Kniess
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
| | - Michael Kluge
- Department of Psychiatry, Universität Leipzig, 04103 Leipzig, Germany.
| | | | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
| | - Ute Krügel
- Rudolf Boehm Institute of Pharmacology and Toxicology, Medical Faculty, Universität Leipzig, 04107 Leipzig, Germany.
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
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19
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Wang L, Chen Q, Ke D, Li G. Ghrelin inhibits atherosclerotic plaque angiogenesis and promotes plaque stability in a rabbit atherosclerotic model. Peptides 2017; 90:17-26. [PMID: 28189525 DOI: 10.1016/j.peptides.2017.01.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/16/2017] [Accepted: 01/27/2017] [Indexed: 12/17/2022]
Abstract
Intraplaque angiogenesis associates with the instability of atherosclerotic plaques. In the present study, we investigated the effects of ghrelin on intraplaque angiogenesis and plaque instability in a rabbit model of atherosclerosis. The rabbits were randomly divided into three groups, namely, the control group, atherosclerotic model group, and ghrelin-treated group, with treatments lasting for 4 weeks. We found that the thickness ratio of the intima to media in rabbits of the ghrelin-treated group was significantly lower than that in rabbits of the atherosclerotic model group. The number of neovessels and the levels of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) decreased dramatically in rabbits of the ghrelin-treated group compared to those of the atherosclerotic model group. Ghrelin significantly decreased the plaque content of macrophages, matrix metalloproteinase (MMP)-2, and MMP-9, in a rabbit model of atherosclerosis. In addition, the level of the pro-inflammatory factor monocyte chemoattractant protein (MCP)-1 was significantly lower in rabbits of the ghrelin-treated group than in rabbits of the atherosclerotic model group. In summary, ghrelin can inhibit intraplaque angiogenesis and promote plaque stability by down-regulating VEGF and VEGFR2 expression, inhibiting the plaque content of macrophages, and reducing MCP-1 expression at an advanced stage of atherosclerosis in rabbits.
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Affiliation(s)
- Li Wang
- Department of Geriatrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China
| | - Qingwei Chen
- Department of Geriatrics, The Second Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing, 400010, China.
| | - Dazhi Ke
- Department of Geriatrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China
| | - Guiqiong Li
- Department of Geriatrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China
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20
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Abstract
Ghrelin is a small peptide released primarily from the stomach. It is a potent stimulator of growth hormone secretion from the pituitary gland and is well known for its regulation of metabolism and appetite. There is also a strong relationship between ghrelin and the cardiovascular system. Ghrelin receptors are present throughout the heart and vasculature and have been linked with molecular pathways, including, but not limited to, the regulation of intracellular calcium concentration, inhibition of proapoptotic cascades, and protection against oxidative damage. Ghrelin shows robust cardioprotective effects including enhancing endothelial and vascular function, preventing atherosclerosis, inhibiting sympathetic drive, and decreasing blood pressure. After myocardial infarction, exogenous administration of ghrelin preserves cardiac function, reduces the incidence of fatal arrhythmias, and attenuates apoptosis and ventricular remodeling, leading to improvements in heart failure. It ameliorates cachexia in end-stage congestive heart failure patients and has shown clinical benefit in pulmonary hypertension. Nonetheless, since ghrelin's discovery is relatively recent, there remains a substantial amount of research needed to fully understand its clinical significance in cardiovascular disease.
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21
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Lufrano D, Trejo SA, Llovera RE, Salgueiro M, Fernandez G, Martínez Damonte V, González Flecha FL, Raingo J, Ermácora MR, Perelló M. Ghrelin binding to serum albumin and its biological impact. Mol Cell Endocrinol 2016; 436:130-40. [PMID: 27431015 DOI: 10.1016/j.mce.2016.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/08/2016] [Accepted: 07/14/2016] [Indexed: 01/07/2023]
Abstract
Ghrelin is an octanoylated peptide hormone that plays a key role in the regulation of the body weight and glucose homeostasis. In plasma, ghrelin circulates bound to larger proteins whose identities are partially established. Here, we used size exclusion chromatography, mass spectrometry and isothermal titration microcalorimetry to show that ghrelin interacts with serum albumin. Furthermore, we found that such interaction displays an estimated dissociation constant (KD) in the micromolar range and involves albumin fatty-acid binding sites as well as the octanoyl moiety of ghrelin. Notably, albumin-ghrelin interaction reduces the spontaneous deacylation of the hormone. Both in vitro experiments-assessing ghrelin ability to inhibit calcium channels-and in vivo studies-evaluating ghrelin orexigenic effects-indicate that the binding to albumin affects the bioactivity of the hormone. In conclusion, our results suggest that ghrelin binds to serum albumin and that this interaction impacts on the biological activity of the hormone.
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Affiliation(s)
- Daniela Lufrano
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina
| | - Sebastián A Trejo
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina; Servei de Proteòmica i Biologia Estructural, Universitat Autònoma de Barcelona, Spain
| | - Ramiro E Llovera
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina
| | - Mariano Salgueiro
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina
| | - Gimena Fernandez
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina
| | | | - F Luis González Flecha
- Instituto de Química y Fisicoquímica Biológicas, Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
| | - Jesica Raingo
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina
| | - Mario R Ermácora
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina; Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina
| | - Mario Perelló
- Instituto Multidisciplinario de Biología Celular, Conicet, Argentina.
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22
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Ghrelin-Induced Enhancement of Vasopressin and Oxytocin Secretion in Rat Neurohypophyseal Cell Cultures. J Mol Neurosci 2016; 60:525-530. [DOI: 10.1007/s12031-016-0850-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/06/2016] [Indexed: 11/26/2022]
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23
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Li J, Zhang M, Wang M, Wang Z, Liu Y, Zhang W, Wang N. GHSR deficiency suppresses neointimal formation in injured mouse arteries. Biochem Biophys Res Commun 2016; 479:125-131. [PMID: 27404127 DOI: 10.1016/j.bbrc.2016.06.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 06/07/2016] [Indexed: 01/25/2023]
Abstract
Growth hormone secretagogue receptor (GHSR) is involved in appetite regulation and energy homeostasis. In the present study, we examined the role of GHSR in neointimal formation following vascular injury. In the mouse model of femoral artery wire injury, we found that vessel intima-to-media ratio was significantly reduced in GHSR deficiency (GHSR-/-) mice compared with that in wild-type mice. Immunohistochemical staining showed that the smooth muscle cell (SMCs) in the neointima were significantly decreased in the injured arteries of GHSR-/- mice which was associated with decreased SMC proliferation and migration. Furthermore, immunoblotting demonstrated that, in cultured rat aortic SMCs, small interfering RNA-mediated GHSR knockdown suppressed the activation of Akt and ERK1/2 signaling pathway. These findings suggested a novel role of GHSR in neointimal formation likely via promoting the proliferation and migration of SMCs involving Akt and ERK1/2 signaling. Therefore, GHSR may be a potential therapeutic target in restenosis and vascular remodeling.
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Affiliation(s)
- Jing Li
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Man Zhang
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Mo Wang
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Zhipeng Wang
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yahan Liu
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Weizhen Zhang
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Nanping Wang
- Institute of Cardiovascular Sciences, Peking University Health Science Center, Beijing 100191, China; The Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, 116044, China.
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24
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Wang L, Chen Q, Li G, Ke D. Ghrelin ameliorates impaired angiogenesis of ischemic myocardium through GHSR1a-mediated AMPK/eNOS signal pathway in diabetic rats. Peptides 2015; 73:77-87. [PMID: 26364514 DOI: 10.1016/j.peptides.2015.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/21/2015] [Accepted: 09/08/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor (GHSR), has been found to stimulate angiogenesis in vivo and in vitro. However, the effect and the corresponding mechanisms of ghrelin on impaired myocardial angiogenesis in diabetic and myocardial infarction (MI) rat model are still unknown. METHODS In the present study, adult SD rats were randomly divided into 4 groups: control, DM, DM+ghrelin, DM+ghrelin+[D-Lys3]-GHRP-6 groups. DM was induced by streptozotocin (STZ) 60 mg/kg body weight. 12 weeks post STZ injection all groups were subjected to MI, which was induced by ligation left anterior descending artery (LAD). Ghrelin and [D-Lys3]-GHRP-6 were administered via intraperitoneal injection at the doses 200 μg/kg and 50mg/kg for 4 weeks, respectively. Left ventricular function, microvascular density (MVD), myocardial infarct size, the expression of hypoxia-inducible factor (HIF1α), vascular endothelial growth factor (VEGF), fetal liver kinase-1 (Flk-1) and fms-like tyrosine kinase-1 (Flt-1), AMPK and endothelial nitric oxide synthase (eNOS) phosphorylation were examined. RESULTS Compared with the DM group, left ventricular ejection fraction (LVEF), fractional shortening (FS), and MVD were increased, whereas myocardial infarct size decreased remarkably in DM+ghrelin group. For the mechanism study, we found that ghrelin promoted the HIF1α, VEGF, Flk-1 and Flt-1 expression, AMPK and eNOS phosphorylation in diabetic rats. However, the above biochemical events in ghrelin treated diabetic rats were completely inhibited by GHSR-1a blocker [D-Lys3]-GHRP-6. CONCLUSIONS These results suggest that administration of ghrelin ameliorates impaired angiogenesis in diabetic MI rats. And these beneficial effects derive from regulating GHSR1a-mediated AMPK/eNOS signal pathway by upregulating of HIF1α, VEGF and its receptors Flk-1, Flt-1 expressions.
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Affiliation(s)
- Li Wang
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Qingwei Chen
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
| | - Guiqiong Li
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Dazhi Ke
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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25
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Wang L, Li G, Chen Q, Ke D. Octanoylated ghrelin attenuates angiogenesis induced by oxLDL in human coronary artery endothelial cells via the GHSR1a-mediated NF-κB pathway. Metabolism 2015; 64:1262-71. [PMID: 26277200 DOI: 10.1016/j.metabol.2015.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 06/24/2015] [Accepted: 07/13/2015] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Low concentrations of oxidized low-density lipoprotein (oxLDL) promote the in vitro angiogenesis of endothelial cells and play an important role in plaque angiogenesis, which may cause plaque vulnerability and enhance the risk of intravascular thrombosis. The aim of this research was to investigate the effects of octanoylated ghrelin on oxLDL-induced angiogenesis and the underlying molecular mechanisms involved in this process. MATERIALS/METHODS Human coronary artery endothelial cells (HCAECs) were incubated with 5 μg/ml oxLDL and treated with various concentrations of octanoylated ghrelin (10(-9)-10(-6)M) with or without inhibitors for 24h. Cell proliferation, migration, and in vitro angiogenesis were analyzed by bromodeoxyuridine (BrdU) staining and BrdU enzyme-linked immunosorbent assay (ELISA), transwell assay, and tube formation on Matrigel, respectively. NF-κB (nuclear factor κB) expression was determined by Western-blot analysis. RESULTS Treatment with oxLDL at 5 μg/ml enhanced the proliferation, migration and tube formation of HCAECs. In contrast, pretreatment with octanoylated ghrelin significantly attenuated in vitro angiogenesis in oxLDL-induced HCAECs. In addition, Western blot analysis indicated that NF-κB expression was increased after oxLDL treatment, and that this effect was significantly reversed by pretreatment with octanoylated ghrelin. However, the NF-κB inhibitor PDTC or the GHSR1a inhibitor [D-Lys3]-GHRP-6 abolished the effects of octanoylated ghrelin on the inhibition of angiogenesis and NF-κB p65 expression induced by oxLDL. CONCLUSIONS These findings suggest that octanoylated ghrelin attenuates angiogenesis induced by oxLDL in HCAECs via the inhibition of GHSR1a-mediated NF-κB pathway. Furthermore, octanoylated ghrelin may promote the stability of vulnerable plaques by inhibiting plaque angiogenesis.
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Affiliation(s)
- Li Wang
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Guiqiong Li
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Qingwei Chen
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
| | - Dazhi Ke
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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26
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Liu Y, Shao XX, Zhang L, Song G, Liu YL, Xu ZG, Guo ZY. Novel bioluminescent receptor-binding assays for peptide hormones: using ghrelin as a model. Amino Acids 2015; 47:2237-43. [DOI: 10.1007/s00726-015-2009-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/13/2015] [Indexed: 11/29/2022]
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27
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Deng B, Fang F, Yang T, Yu Z, Zhang B, Xie X. Ghrelin inhibits AngII -induced expression of TNF-α, IL-8, MCP-1 in human umbilical vein endothelial cells. Int J Clin Exp Med 2015; 8:579-588. [PMID: 25785032 PMCID: PMC4358487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 01/09/2015] [Indexed: 06/04/2023]
Abstract
AIM Ghrelin, a gastric peptide, is involved in several metabolic and cardiovascular processes. Emerging evidence indicates the potential involvement of ghrelin in low-grade inflammatory diseases such as atherosclerosis and hypertension. Cytokine-induced inflammation is critical in these pathological states. The growth hormone secretagogue receptor (GHSR) has been identified in blood vessels, so we predict that ghrelin might inhibit proinflammatory responses in human umbilical vein endothelial cells (HUVECs). The aim of this study is to examine the effect of ghrelin on angiotension II (AngII)-induced expression of TNF-α, MCP-1, IL-8 in HUVECs. METHOD HUVECs were pretreated with ghrelin, with or without the specific antagonist of GHSR [D-Lys(3)]-GHRP-6, the selective inhibitor of nuclear factor-kappaB (NF-κB) PDTC, and the selective inhibitor of extracellular signal-regulated kinase (ERK1/2) PD98059. The cells were finally treated with AngII. The expression of TNF-α, MCP-1, IL-8 was examined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). The activity of ERK1/2 and NF-κB was analyzed by Western blot. RESULT our study showed that ghrelin inhibited AngII -induced expression of IL-8, TNF-α and MCP-1 in the HUVECs via GHSR pathway in concentration- and time-dependent manners. We also found that ghrelin inhibited AngII -induced activation of ERK1/2 and NF-κB. CONCLUSIONS these results suggest that Ghrelin may play novel antiinflammatory and immunoregulatory roles in HUVECs.
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Affiliation(s)
- Bin Deng
- Department of Cardiology, Xiang Ya Hospital, Central South University87 Xiang Ya Road, Changsha 410008, Hunan, P. R. China
| | - Fang Fang
- Department of Cardiology, Xiang Ya Hospital, Central South University87 Xiang Ya Road, Changsha 410008, Hunan, P. R. China
| | - Tianlu Yang
- Department of Cardiology, Xiang Ya Hospital, Central South University87 Xiang Ya Road, Changsha 410008, Hunan, P. R. China
| | - Zaixin Yu
- Department of Cardiology, Xiang Ya Hospital, Central South University87 Xiang Ya Road, Changsha 410008, Hunan, P. R. China
| | - Bin Zhang
- Department of Histololgy and Embryololgy, Xiang Ya Medical College, Central South University172 Tongzipo Road, Changsha 410013, Hunan, P. R. China
| | - Xiumei Xie
- Department of Geriatrics, Xiang Ya Hospital, Central South University87 Xiang Ya Road, Changsha 410008, Hunan, P. R. China
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Soeki T, Koshiba K, Niki T, Kusunose K, Yamaguchi K, Yamada H, Wakatsuki T, Shimabukuro M, Minakuchi K, Kishimoto I, Kangawa K, Sata M. Effect of ghrelin on autonomic activity in healthy volunteers. Peptides 2014; 62:1-5. [PMID: 25265271 DOI: 10.1016/j.peptides.2014.09.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/18/2014] [Accepted: 09/18/2014] [Indexed: 02/06/2023]
Abstract
Ghrelin is a novel growth hormone (GH)-releasing peptide originally isolated from the stomach. Recently, we have shown that ghrelin suppresses cardiac sympathetic activity and prevents early left ventricular remodeling in rats with myocardial infarction. In the present study, we evaluated the effect of ghrelin on autonomic nerve activity in healthy human subjects. An intravenous bolus of human synthetic ghrelin (10μg/kg) was administered to 10 healthy men (mean age, 33 years). Holter monitoring assessment was performed before and during 2h after the ghrelin therapy. The standard deviation of normal RR intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent RR intervals (rMSSD), high-frequency power (HF), and low-frequency power (LF) were analyzed. Blood samples were also obtained before and after the therapy. A single administration of ghrelin decreased both heart rate and blood pressure. Interestingly, ghrelin significantly decreased the LF and LF/HF ratio of heart rate variability and increased the SDNN, rMSSD, and HF. Ghrelin also elicited a marked increase in circulating GH, but not insulin-like growth factor-1. These data suggest that ghrelin might suppress cardiac sympathetic nerve activity and stimulate cardiac parasympathetic nerve activity.
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Affiliation(s)
- Takeshi Soeki
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
| | - Kunihiko Koshiba
- Department of Cardiovascular Medicine, Anan Central Hospital of the Medical Association, Anan, Japan
| | - Toshiyuki Niki
- Department of Cardiovascular Medicine, Shikoku Medical Center for Children and Adults, Zentsuji, Japan
| | - Kenya Kusunose
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Koji Yamaguchi
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Hirotsugu Yamada
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Tetsuzo Wakatsuki
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Michio Shimabukuro
- Department of Cardio-Diabetes Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Kazuo Minakuchi
- Department of Clinical Pharmacy, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Ichiro Kishimoto
- National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Kenji Kangawa
- National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Masataka Sata
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
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Synthesis and in vitro/in vivo evaluation of novel mono- and trivalent technetium-99m labeled ghrelin peptide complexes as potential diagnostic radiopharmaceuticals. Nucl Med Biol 2014; 42:28-37. [PMID: 25218025 DOI: 10.1016/j.nucmedbio.2014.08.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/23/2014] [Accepted: 08/16/2014] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Ghrelin is an endogenous hormone present in blood. It is released from the oxyntic cells (X/A-like cells) of the stomach and fundus and can exist in two forms: as an acylated and des-acylated ghrelin. Ghrelin is an endogenous ligand of the growth hormone receptor (growth hormone secretagogue receptor, GHS-R). Overexpression of GHS-R1a receptor was identified in cells of different types of tumors (e.g. pituitary adenoma, neuroendocrine tumors of the thyroid, lung, breast, gonads, prostate, stomach, colorectal, endocrine and non-endocrine pancreatic tumors). This fact suggests that gamma radionuclide labeled ghrelin peptide may be considered as a potential diagnostic radiopharmaceutical. METHODS Ghrelin peptide labeled with mono- and trivalent technetium-99m complexes, (99m)Tc-Lys-GHR, has been prepared on the n.c.a. scale. The physicochemical (stability, charge, shape, lipophilicity) and biological (receptor affinity, biodistribution) properties of the conjugates have been studied relevant to use the conjugates as receptor-based diagnostic radiopharmaceuticals. RESULTS The obtained conjugates [(99m)Tc(CO)3LN,O(CN-Lys-GHR)](+), (99m)Tc(CO)3LS,O(CN-Lys-GHR) and (99m)Tc(NS3)(CN-Lys-GHR) show different shape, charge, lipophilicity and two of them, (99m)Tc(CO)3LS,O(CN-Lys-GHR) and (99m)Tc(NS3)(CN-Lys-GHR), high stability in neutral aqueous solutions, even in the presence of excess concentration of histidine/cysteine competitive standard ligands or human serum. The in vitro binding affinity of (99m)Tc-Lys-GHR conjugates with respect to growth hormone secretagogue receptor (GHS-R1a) present on DU-145 cells was in the range of IC50 from 45 to 54 nM. The conjugate (99m)Tc(CO)3LS,O(CN-Lys-GHR) exhibited excretion route by the liver and kidney in comparable degree, while the more lipophilic conjugate (99m)Tc(NS3)(CN-Lys-GHR)-mainly by the liver. CONCLUSIONS Basing on the results concerning physicochemical and biochemical properties, the conjugates (99m)Tc(CO)3LS,O(CN-Lys-GHR) and (99m)Tc(NS3)(CN-Lys-GHR) might be considered to be promising models for diagnostic radiopharmaceutical.
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Callaghan B, Furness JB. Novel and Conventional Receptors for Ghrelin, Desacyl-Ghrelin, and Pharmacologically Related Compounds. Pharmacol Rev 2014; 66:984-1001. [DOI: 10.1124/pr.113.008433] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Mao Y, Tokudome T, Kishimoto I. Ghrelin as a treatment for cardiovascular diseases. Hypertension 2014; 64:450-4. [PMID: 24958496 DOI: 10.1161/hypertensionaha.114.03726] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Yuanjie Mao
- From the Department of Biochemistry (Y.M., T.T.) and Department of Endocrinology and Metabolism (I.K.), National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Takeshi Tokudome
- From the Department of Biochemistry (Y.M., T.T.) and Department of Endocrinology and Metabolism (I.K.), National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Ichiro Kishimoto
- From the Department of Biochemistry (Y.M., T.T.) and Department of Endocrinology and Metabolism (I.K.), National Cerebral and Cardiovascular Center, Osaka, Japan.
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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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Douglas GAF, McGirr R, Charlton CL, Kagan DB, Hoffman LM, Luyt LG, Dhanvantari S. Characterization of a far-red analog of ghrelin for imaging GHS-R in P19-derived cardiomyocytes. Peptides 2014; 54:81-8. [PMID: 24468548 DOI: 10.1016/j.peptides.2014.01.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/16/2014] [Accepted: 01/16/2014] [Indexed: 11/29/2022]
Abstract
Ghrelin and its receptor, the growth hormone secretagogue receptor (GHS-R), are expressed in the heart, and may function to promote cardiomyocyte survival, differentiation and contractility. Previously, we had generated a truncated analog of ghrelin conjugated to fluorescein isothiocyanate for the purposes of determining GHS-R expression in situ. We now report the generation and characterization of a far-red ghrelin analog, [Dpr(3)(octanoyl), Lys(19)(Cy5)]ghrelin (1-19), and show that it can be used to image changes in GHS-R in developing cardiomyocytes. We also generated the des-acyl analog, des-acyl [Lys(19)(Cy5)]ghrelin (1-19) and characterized its binding to mouse heart sections. Receptor binding affinity of Cy5-ghrelin as measured in HEK293 cells overexpressing GHS-R1a was within an order of magnitude of that of fluorescein-ghrelin and native human ghrelin, while the des-acyl Cy5-ghrelin did not bind GHS-R1a. Live cell imaging in HEK293/GHS-R1a cells showed cell surface labeling that was displaced by excess ghrelin. Interestingly, Cy5-ghrelin, but not the des-acyl analog, showed concentration-dependent binding in mouse heart tissue sections. We then used Cy5-ghrelin to track GHS-R expression in P19-derived cardiomyocytes. Live cell imaging at different time points after DMSO-induced differentiation showed that GHS-R expression preceded that of the differentiation marker aMHC and tracked with the contractility marker SERCA 2a. Our far-red analog of ghrelin adds to the tools we are developing to map GHS-R in developing and diseased cardiac tissues.
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Affiliation(s)
- Gregory A F Douglas
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Rebecca McGirr
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Carlie L Charlton
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Dov B Kagan
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Lisa M Hoffman
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Leonard G Luyt
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Savita Dhanvantari
- Departments of Pathology, Chemistry, Medical Imaging, Medical Biophysics, and Oncology, Western University, Richmond Street, London, Ontario, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada.
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors. Br J Pharmacol 2013; 170:1459-581. [PMID: 24517644 PMCID: PMC3892287 DOI: 10.1111/bph.12445] [Citation(s) in RCA: 505] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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Zhang M, Fang WY, Qu XK, Yuan F, Wang WG, Fei J, Wang ZG. AMPK activity is down-regulated in endothelial cells of GHS-R(-/-) mice. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2013; 6:1770-1780. [PMID: 24040441 PMCID: PMC3759483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 07/26/2013] [Indexed: 06/02/2023]
Abstract
Ghrelin/GHS-R axis is known as its role in stimulating growth hormone release. Besides, it is also implicated in the regulation of atherosclerosis (AS), a chronic vascular disease that has been recognized as the main cause of coronary heart disease and cerebrovascular disease. It has been reported that both Ghrelin and AMPK play protective roles in AS by inhibiting the inflammatory response as well as cell proliferation. However, it remains unclear whether AMPK pathway is involved in Ghrelin/GHS-R-mediated inhibition of the inflammatory response and cell proliferation in AS. Here, we established the GHS-R gene knockout mice (GHS-R(-/-)) and found that AMPK activity is notably down-regulated in endothelial cells (ECs) of GHS-R(-/-) mice and the ECs from GHS-R(-/-) mice possess higher proliferative capability than the ECs from wild-type mice. Moreover, AMPK is activated in primary ECs upon Ghrelin induction in vitro. Taking together, the present study unravels that Ghrelin/GHS-R could efficiently activate AMPK in ECs, suggesting a possible mechanism that the roles of Ghrelin/GHS-R in the inhibition of inflammatory response and cell proliferation in AS disease may be partially mediated by activating AMPK.
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Affiliation(s)
- Min Zhang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of MedicineShanghai 200030, China
| | - Wei-Yi Fang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of MedicineShanghai 200030, China
| | - Xin-Kai Qu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of MedicineShanghai 200030, China
| | - Fang Yuan
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of MedicineShanghai 200030, China
| | - Wei-Gang Wang
- School of Life and Health Sciences, Tongji UniversityShanghai 200092, China
| | - Jian Fei
- School of Life and Health Sciences, Tongji UniversityShanghai 200092, China
| | - Zhi-Gang Wang
- Department of General Surgery, the Sixth People’s Hospital, Shanghai Jiaotong UniversityShanghai 200233, China
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Chen X, Chen Q, Wang L, Li G. Ghrelin induces cell migration through GHSR1a-mediated PI3K/Akt/eNOS/NO signaling pathway in endothelial progenitor cells. Metabolism 2013; 62:743-52. [PMID: 23218924 DOI: 10.1016/j.metabol.2012.09.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/16/2012] [Accepted: 09/24/2012] [Indexed: 01/18/2023]
Abstract
OBJECTIVE The purpose of this research was to investigate the effects of ghrelin on circulating endothelial progenitor cells (EPC) directional migration and its underlying molecular mechanisms involved in this process. MATERIALS/METHODS EPC were isolated from bone marrow of SD rats by using Percoll density gradient centrifugation, and characterized by double positive for acLDL-Dil uptake and FITC-UEA-1 binding and immunocytochemistry for CD34, CD133, vWF and Flk-1. EPC were treated with different concentrations of ghrelin (10(-9)~10(-6)M) with or without GHSR1a inhibitor [D-Lys3]-GHRP-6, PI3K inhibitor LY294002 and endothelial nitric oxide synthase (eNOS) inhibitor L-NAME, migration of EPC was detected by transwell assay, levels of phosphorylated and total Akt and eNOS were determined by Western-blot analysis and Nitric Oxide (NO) production was measured by Griess assay, respectively. RESULTS EPC were successfully obtained by Percoll density gradient centrifugation and ghrelin at 10(-8)M~10(-7)M promoted EPC migration. Ghrelin-induced EPC migration was accompanied by phosphorylation of Akt and eNOS, as well as an increase in NO production. These biochemical events and EPC directional migration induced by ghrelin were completely inhibited by GHSR-1a blocker [D-Lys3]-GHRP-6. PI3K inhibitor LY294002 attenuated ghrelin-induced EPC migration, phosphorylation of Akt and eNOS, and NO production. eNOS inhibitor L-NAME blocked ghrelin-induced EPC migration, phosphorylation of eNOS, and NO production, but had no effect on Akt phosphorylation. CONCLUSIONS These findings suggest that ghrelin stimulates EPC directional migration via GHSR1a-mediated PI3K/Akt/eNOS/NO signal pathway. It indicates that ghrelin may be used as a therapeutic strategy to treat ischemic diseases by promoting EPC directional migration.
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Affiliation(s)
- Xiaodong Chen
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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Guven B, Gokce M, Saydam O, Can M, Bektas S, Yurtlu S. Effect of ghrelin on inflammatory response in lung contusion. Kaohsiung J Med Sci 2012; 29:69-74. [PMID: 23347807 DOI: 10.1016/j.kjms.2012.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 12/05/2011] [Indexed: 12/14/2022] Open
Abstract
The purpose of this study was to investigate the effects of ghrelin on inflammatory response and tissue damage following trauma-induced acute lung injury. Thirty male wistar albino rats (300-400 g) were randomly assigned into three groups: control group (n = 6), lung contusion plus saline (saline-treated, n = 12), and lung contusion plus ghrelin (ghrelin-treated, n = 12). Saline- or ghrelin-treated traumatic rats were sacrificed at two time points (24 and 72 hours) after lung contusion. Blood was collected for the analysis of serum adenosine deaminase (ADA). Tissue transforming growth factor-beta 1 (TGF-β1) and matrix metalloproteinase-2 (MMP-2) levels were measured by enzyme-linked immunosorbent assay and histopathological examination was performed on the lung tissue samples. Our results indicated that ghrelin significantly reduced morphologic damages. Serum ADA activities were significantly decreased after lung contusion and this decline started early with ghrelin treatment. TGF-β1 and MMP-2 levels in lung tissue were elevated at 72 hours after lung contusion and treatment with ghrelin significantly increased TGF-β1 level and reduced MMP-2 level. In conclusion, our study demonstrates that acute lung injury initiated proinflammatory responses and ghrelin administration showed an anti-inflammatory effect in lung contusion.
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Affiliation(s)
- Berrak Guven
- Department of Biochemistry, Faculty of Medicine, Bulent Ecevit University (Formerly Karaelmas University), Zonguldak, Turkey.
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Novel domain-selective ACE-inhibiting activity of synthetic growth hormone secretagogues. Pharmacol Res 2012; 66:317-24. [DOI: 10.1016/j.phrs.2012.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 06/14/2012] [Accepted: 06/14/2012] [Indexed: 11/18/2022]
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Majchrzak K, Pawłowski KM, Orzechowska EJ, Dolka I, Mucha J, Motyl T, Król M. A role of ghrelin in canine mammary carcinoma cells proliferation, apoptosis and migration. BMC Vet Res 2012; 8:170. [PMID: 22999388 PMCID: PMC3514346 DOI: 10.1186/1746-6148-8-170] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 09/20/2012] [Indexed: 11/13/2022] Open
Abstract
Background Ghrelin is a natural ligand of the growth hormone secretagogue receptor (GHS-R). They are often co-expressed in multiple human tumors and related cancer cell lines what can indicate that the ghrelin/GHS-R axis may have an important role in tumor growth and progression. However, a role of ghrelin in canine tumors remains unknown. Thus, the aim of our study was two-fold: (1) to assess expression of ghrelin and its receptor in canine mammary cancer and (2) to examine the effect of ghrelin on carcinoma cells proliferation, apoptosis, migration and invasion. The expression of ghrelin and its receptor in canine mammary cancer tissues and cell lines (isolated from primary tumors and their metastases) was examined using Real-time qPCR and immunohistochemistry. For apoptosis analysis the Annexin V and propidium iodide dual staining was applied whereas cell proliferation was evaluated by MTT assay and BrdU incorporation test. The influence of ghrelin on cancer cells migration and invasion was assessed using Boyden chamber assays and wound healing assay. Results The highest expression of ghrelin was observed in metastatic cancers whereas the lowest expression of ghrelin receptor was detected in tumors of the 3rd grade of malignancy. Higher expression of ghrelin and its receptor was detected in cancer cell lines isolated from metastases than in cell lines isolated from primary tumors. In vitro experiments demonstrated that exposure to low doses of ghrelin stimulates cellular proliferation, inhibits apoptosis and promotes motility and invasion of canine mammary cancer cells. Growth hormone secretagogue receptor inhibitor ([D-Lys3]-GHRP6) as well as RNA interference enhances early apoptosis. Conclusion The presence of ghrelin and GHS-R in all of the examined canine mammary tumors may indicate their biological role in cancer growth and development. Our experiments conducted in vitro confirmed that ghrelin promotes cancer development and metastasis.
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Affiliation(s)
- Kinga Majchrzak
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences - WULS, Nowoursynowska 159, Warsaw, 02-776, Poland
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Ghrelin protects H9c2 cardiomyocytes from angiotensin II-induced apoptosis through the endoplasmic reticulum stress pathway. J Cardiovasc Pharmacol 2012; 59:465-71. [PMID: 22269847 DOI: 10.1097/fjc.0b013e31824a7b60] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Ghrelin, a gastric hormone, exerts cardioprotective function by increasing myocardial contractility and vasodilation. Previous studies have reported that angiotensin II (Ang II) production increased in heart failure, which can induce cardiomyocyte apoptosis. In this study, we investigated the effect of ghrelin on Ang II-induced H9c2 cardiomyocyte apoptosis. The results showed that Ang II inhibited H9c2 cell viability, which was blocked by ghrelin. By annexin V-propidium iodide dual staining and 2'-deoxyuridine 5'-triphosphate nick end-labeling analysis, we found that Ang II induced H9c2 cell apoptosis, whereas coincubation of ghrelin with Ang II significantly reduced H9c2 cell apoptosis induced by Ang II. Simultaneously, the results revealed that ghrelin regulated the Ang II-induced imbalance of Bax and Bcl-2 expression and reduced Ang II-induced caspase-3 expression. Moreover, mRNA expressions of endoplasmic reticulum stress-related molecules GRP78, caspase-12, and C/EBP homologous protein were significantly upregulated by Ang II. However, their expressions were significantly inhibited by ghrelin. In addition, we found that ghrelin markedly inhibited Ang II-induced Ang II type 1 receptor expression. These data suggest that ghrelin may play an antagonistic role in Ang II-induced cardiomyocyte apoptosis via decreasing Ang II type 1 receptor expression and inhibiting the activation of endoplasmic reticulum stress pathway.
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In vitro selection of a peptide antagonist of growth hormone secretagogue receptor using cDNA display. Proc Natl Acad Sci U S A 2012; 109:11121-6. [PMID: 22723348 DOI: 10.1073/pnas.1203561109] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are major drug targets, and their ligands are currently being explored and developed by many pharmaceutical companies and independent researchers. Class A (rhodopsin-like) GPCRs compose a predominant GPCR family; therefore, class A GPCR ligands are in demand. Growth hormone secretagogue receptor (GHS-R) is a class A GPCR that stimulates food intake by binding to its peptide ligand, ghrelin. Therefore, antagonists of GHS-R are expected to exert antiobesity function. In this article, we describe the use of cDNA display to screen for successfully and identify an antagonistic peptide of GHS-R. The antagonistic peptide inhibited the ghrelin-induced increase in intracellular Ca(2+) in vitro (IC(50) = approximately 10 μM) and repressed the contraction of isolated animal stomach in response to ghrelin. Furthermore, peripheral administration of the peptide inhibited the food intake of mice. This work provides new insight into the development of antiobesity drugs and describes a method for the discovery of unique peptide ligands for class A GPCRs.
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Plasma ghrelin levels are closely associated with severity and morphology of angiographically-detected coronary atherosclerosis in Chineses patients with diabetes mellitus. Acta Pharmacol Sin 2012; 33:452-8. [PMID: 22367281 DOI: 10.1038/aps.2011.196] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
AIM Low plasma ghrelin level was found to be associated with diabetes, and ghrelin was shown to inhibit pro-atherogenic changes in experimental models of atherosclerosis. The aim of this study was to investigate the relationship between plasma ghrelin levels and coronary atherosclerotic lesions in Chinese patients with diabetes. METHODS Plasma ghrelin levels were measured using an ELISA kit. The severity of coronary artery disease (CAD) was determined via angiography. Composition of atherosclerotic plaques was detected via coronary CT angiography. RESULTS A total of 178 patients with diabetes were recruited. Among the patients, 70 were diagnosed with acute coronary syndrome (ACS), 82 with stable angina pectoris (SAP) and 26 without coronary angiographic finding (controls). A negative correlation was found between ghrelin levels and the severity of the CAD, as determined via the Gensini score (r=-0.2434; P=0.0217). In diabetic patients with CAD and a complex lesion, the plasma ghrelin levels were significantly lower than in those with a simple lesion (ACS group: 3.81 ± 0.49 ng/mL vs 4.72 ± 0.50 ng/mL, P<0.0001; SAP group: 4.21 ± 0.52 ng/mL vs 4.76 ± 0.59 ng/mL, P=0.0397). Angiographically-detected complex lesion was an independent factor associated with ghrelin levels (adjusted beta coefficient=-0.67, 95% CI -0.97 to -0.37, P<0.0001). CONCLUSION Low plasma ghrelin level is closely related to angiographically-detected severity and the complex lesion morphology in Chinese diabetic patients with CAD.
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Abstract
Radioligand binding is widely used to characterize receptors and determine their anatomical distribution, particularly the superfamily of seven transmembrane-spanning G protein-coupled receptors for both established transmitters such as endothelin-1 and an increasing number of orphan receptors recently paired with their cognate ligands. Three types of assay are described. In saturation experiments, tissue sections, cultured cells, or homogenates are incubated with an increasing concentration of a radiolabeled ligand, which can be a labeled analog of a naturally occurring transmitter, hormone, or synthetic drug. Analysis using iterative nonlinear curve-fitting programs, such as KELL, measures the affinity of the labeled ligand for a receptor (equilibrium dissociation constant, K ( D )), receptor density (B (max)), and Hill slope (nH). The affinity and selectivity of an unlabeled ligand to compete for the binding of a fixed concentration of a radiolabeled ligand to a receptor are determined using a competition binding assay. Kinetic assays measure the rate of association to or dissociation from a receptor from which a kinetic K ( D ) may be derived. Quantitative autoradiography and image analysis is a sensitive technique to detect low levels of radiolabeled ligands and determine the anatomical distribution of receptors in sections that retain the morphology of the tissue. The measurement of bound radioligand within discrete regions of autoradiographical images using -computer-assisted image analysis is described.
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Affiliation(s)
- Janet J Maguire
- Clinical Pharmacology Unit, Addenbrooke's Centre for Clinical Investigation, University of Cambridge, Cambridge, UK.
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Wang L, Chen Q, Li G, Ke D. Ghrelin stimulates angiogenesis via GHSR1a-dependent MEK/ERK and PI3K/Akt signal pathways in rat cardiac microvascular endothelial cells. Peptides 2012; 33:92-100. [PMID: 22100225 DOI: 10.1016/j.peptides.2011.11.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 11/01/2011] [Accepted: 11/01/2011] [Indexed: 12/31/2022]
Abstract
Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor (GHSR), is thought to exert a protective effect on the cardiovascular system, specifically by promoting vascular endothelial cell function such as cell proliferation, migration, survival and angiogenesis. However, the effect of ghrelin on angiogenesis and the corresponding mechanisms have not yet been extensively studied in cardiac microvascular endothelial cells (CMECs) isolated from left ventricular myocardium of adult Sprague-Dawley (SD) rats. In our study, we found that ghrelin and GHSR are constitutively expressed in CMECs. Ghrelin significantly increases CMECs proliferation, migration, and in vitro angiogenesis. The ghrelin-induced angiogenic process was accompanied by phosphorylation of ERK and Akt. MEK inhibitor PD98059 abolished ghrelin-induced phosphorylation of ERK, but had no effect on Akt phosphorylation. PI3K inhibitor LY294002 abolished ghrelin-induced phosphorylation of Akt, but had no effect on ERK phosphorylation. Ghrelin-induced angiogenesis was partially blocked by treatment with PD98059 or LY294002. In addition, this angiogenic effect was almost completely inhibited by PD98059+LY294002. Pretreatment with GHSR1a blocker [D-Lys3]-GHRP-6 abolished ghrelin-induced phosphorylation of ERK, Akt and in vitro angiogenesis. In conclusion, this is the first demonstration that ghrelin stimulates CMECs angiogenesis through GHSR1a-mediated MEK/ERK and PI3K/Akt signal pathways, indicating that two pathways are required for full angiogenic activity of ghrelin. This study suggests that ghrelin may play an important role in myocardial angiogenesis.
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Affiliation(s)
- Li Wang
- Department of Geriatrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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45
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McGirr R, McFarland MS, McTavish J, Luyt LG, Dhanvantari S. Design and characterization of a fluorescent ghrelin analog for imaging the growth hormone secretagogue receptor 1a. ACTA ACUST UNITED AC 2011; 172:69-76. [DOI: 10.1016/j.regpep.2011.08.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 08/17/2011] [Accepted: 08/23/2011] [Indexed: 01/11/2023]
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46
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Hoveyda HR, Marsault E, Gagnon R, Mathieu AP, Vézina M, Landry A, Wang Z, Benakli K, Beaubien S, Saint-Louis C, Brassard M, Pinault JF, Ouellet L, Bhat S, Ramaseshan M, Peng X, Foucher L, Beauchemin S, Bhérer P, Veber DF, Peterson ML, Fraser GL. Optimization of the Potency and Pharmacokinetic Properties of a Macrocyclic Ghrelin Receptor Agonist (Part I): Development of Ulimorelin (TZP-101) from Hit to Clinic. J Med Chem 2011; 54:8305-20. [DOI: 10.1021/jm2007062] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Hamid R. Hoveyda
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Eric Marsault
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - René Gagnon
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Axel P. Mathieu
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Martin Vézina
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Annick Landry
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Zhigang Wang
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Kamel Benakli
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Sylvie Beaubien
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Carl Saint-Louis
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Martin Brassard
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | | | - Luc Ouellet
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Shridhar Bhat
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Mahesh Ramaseshan
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Xiaowen Peng
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Laurence Foucher
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Sophie Beauchemin
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Patrick Bhérer
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Daniel F. Veber
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Mark L. Peterson
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Graeme L. Fraser
- Tranzyme Pharma Inc., 3001,
12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada
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47
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Pinyot A, Nikolovski Z, Bosch J, Such-Sanmartín G, Kageyama S, Segura J, Gutiérrez-Gallego R. Growth hormone secretagogues: out of competition. Anal Bioanal Chem 2011; 402:1101-8. [DOI: 10.1007/s00216-011-5544-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/11/2011] [Accepted: 10/27/2011] [Indexed: 10/15/2022]
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48
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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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49
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Zhang G, Yin X, Qi Y, Pendyala L, Chen J, Hou D, Tang C. Ghrelin and cardiovascular diseases. Curr Cardiol Rev 2011; 6:62-70. [PMID: 21286280 PMCID: PMC2845796 DOI: 10.2174/157340310790231662] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 03/27/2009] [Accepted: 04/03/2009] [Indexed: 01/19/2023] Open
Abstract
Ghrelin, a newly discovered bioactive peptide, is a natural endogenous ligand of the growth hormone (GH) secretagogue receptor and initially identified as a strong stimulant for the release of GH. Subsequent research has shown that ghrelin and its various receptors are ubiquitous in many other organs and tissues. Moreover, they participate in the regulation of appetite, energy, bodyweight, metabolism of glucose and fat, as well as modulation of gastrointestinal, cardiovascular, pulmonary, immune functions and cell proliferation/apoptosis. Increasing evidence has demonstrated that ghrelin has a close relationship with cardiovascular system. Ghrelin and its receptors are widely distributed in cardiovascular tissues, and there is no doubt that the effects of ghrelin in the cardiovascular system are mediated not only via its growth-hormone-releasing effect but also by its direct effects on the heart. Exogenous administration of ghrelin can dilate peripheral blood vessels, constrict coronary artery, improve endothelial function, as well as inhibit myocardial cell apoptosis. So, ghrelin may have cardiovascular protective effect, including lowering of blood pressure, regulation of atherosclerosis, and protection from ischemia/reperfusion injury as well as improving the prognosis of myocardial infarction and heart failure. Some of these new functions of ghrelin may provide new potential therapeutic opportunities for ghrelin in cardiovascular medicine. In this paper, we will review the existing evidence for cardiovascular effects of ghrelin, including the cardiovascular function, the variations in ghrelin plasma levels in pathophysiologicalogical conditions, the possible protective mechanisms of ghrelin, as well as its future potential therapeutic roles.
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Affiliation(s)
- Gaigai Zhang
- Cardiology Department, the First Affiliated Hospital of Harbin Medical University, Harbin,P. R. China 150081
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50
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Potter R, Horti AG, Ravert HT, Holt DP, Finley P, Scheffel U, Dannals RF, Wahl RL. Synthesis and in vivo evaluation of (S)-6-(4-fluorophenoxy)-3-((1-[11C]methylpiperidin-3-yl)methyl)-2-o-tolylquinazolin-4(3H)-one, a potential PET tracer for growth hormone secretagogue receptor (GHSR). Bioorg Med Chem 2011; 19:2368-72. [PMID: 21388815 DOI: 10.1016/j.bmc.2011.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 02/04/2011] [Accepted: 02/11/2011] [Indexed: 10/18/2022]
Abstract
The peptide hormone ghrelin mediates through action on its receptor, the growth hormone secretagogue receptor (GHSR), and is known to play an important role in a variety of metabolic functions including appetite stimulation, weight gain, and suppression of insulin secretion. In light of the fact that obesity is one of the major health problems plaguing the modern society, the ghrelin signaling system continues to remain an important and attractive pharmacological target for the treatment of obesity. In vivo imaging of the GHSR could shed light on the mechanism by which ghrelin affects feeding behavior and thus offers a new therapeutic perspective for the development of effective treatments. Recently, a series of piperidine-substituted quinazolinone derivatives was reported to be selective and potent GHSR antagonists with high binding affinities. Described herein is the synthesis, in vitro, and in vivo evaluation of (S)-6-(4-fluorophenoxy)-3-((1-[(11)C]methylpiperidin-3-yl)methyl)-2-o-tolylquinazolin-4(3H)-one ([(11)C]1), a potential PET radioligand for imaging GHSR.
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Affiliation(s)
- Rachel Potter
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA
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