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Lund LH, Hage C, Pironti G, Thorvaldsen T, Ljung-Faxén U, Zabarovskaja S, Shahgaldi K, Webb DL, Hellström PM, Andersson DC, Ståhlberg M. Acyl ghrelin improves cardiac function in heart failure and increases fractional shortening in cardiomyocytes without calcium mobilization. Eur Heart J 2023; 44:2009-2025. [PMID: 36916707 PMCID: PMC10256198 DOI: 10.1093/eurheartj/ehad100] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 01/05/2023] [Accepted: 02/13/2023] [Indexed: 03/16/2023] Open
Abstract
BACKGROUND AND AIMS Ghrelin is an endogenous appetite-stimulating peptide hormone with potential cardiovascular benefits. Effects of acylated (activated) ghrelin were assessed in patients with heart failure and reduced ejection fraction (HFrEF) and in ex vivo mouse cardiomyocytes. METHODS AND RESULTS In a randomized placebo-controlled double-blind trial, 31 patients with chronic HFrEF were randomized to synthetic human acyl ghrelin (0.1 µg/kg/min) or placebo intravenously over 120 min. The primary outcome was change in cardiac output (CO). Isolated mouse cardiomyocytes were treated with acyl ghrelin and fractional shortening and calcium transients were assessed. Acyl ghrelin but not placebo increased cardiac output (acyl ghrelin: 4.08 ± 1.15 to 5.23 ± 1.98 L/min; placebo: 4.26 ± 1.23 to 4.11 ± 1.99 L/min, P < 0.001). Acyl ghrelin caused a significant increase in stroke volume and nominal increases in left ventricular ejection fraction and segmental longitudinal strain and tricuspid annular plane systolic excursion. There were no effects on blood pressure, arrhythmias, or ischaemia. Heart rate decreased nominally (acyl ghrelin: 71 ± 11 to 67 ± 11 b.p.m.; placebo 69 ± 8 to 68 ± 10 b.p.m.). In cardiomyocytes, acyl ghrelin increased fractional shortening, did not affect cellular Ca2+ transients, and reduced troponin I phosphorylation. The increase in fractional shortening and reduction in troponin I phosphorylation was blocked by the acyl ghrelin antagonist D-Lys 3. CONCLUSION In patients with HFrEF, acyl ghrelin increased cardiac output without causing hypotension, tachycardia, arrhythmia, or ischaemia. In isolated cardiomyocytes, acyl ghrelin increased contractility independently of preload and afterload and without Ca2+ mobilization, which may explain the lack of clinical side effects. Ghrelin treatment should be explored in additional randomized trials. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT05277415.
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Affiliation(s)
- Lars H Lund
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Heart and Vascular Theme, Karolinska University Hospital, Norrbacka, S1:02, 171 76 Stockholm, Sweden
| | - Camilla Hage
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Heart and Vascular Theme, Karolinska University Hospital, Norrbacka, S1:02, 171 76 Stockholm, Sweden
| | - Gianluigi Pironti
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, Solnavägen 9 171 65 Solna, Sweden
| | - Tonje Thorvaldsen
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Heart and Vascular Theme, Karolinska University Hospital, Norrbacka, S1:02, 171 76 Stockholm, Sweden
| | - Ulrika Ljung-Faxén
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Perioperative Medicine and Intensive Care, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Stanislava Zabarovskaja
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
| | - Kambiz Shahgaldi
- Department of Clinical Physiology, Sunderby Hospital, 971 80 Luleå, Sweden
| | - Dominic-Luc Webb
- Department of Medical Sciences, Gastroenterology and Hepatology, Uppsala University, 751 05 Uppsala, Sweden
| | - Per M Hellström
- Department of Medical Sciences, Gastroenterology and Hepatology, Uppsala University, 751 05 Uppsala, Sweden
| | - Daniel C Andersson
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Heart and Vascular Theme, Karolinska University Hospital, Norrbacka, S1:02, 171 76 Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, Solnavägen 9 171 65 Solna, Sweden
| | - Marcus Ståhlberg
- Department of Medicine, Unit of Cardiology, Karolinska Institutet, D1:04, 171 76 Stockholm, Sweden
- Heart and Vascular Theme, Karolinska University Hospital, Norrbacka, S1:02, 171 76 Stockholm, Sweden
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Ege D, Nawaz Q, Beltrán AM, Boccaccini AR. Effect of Boron-Doped Mesoporous Bioactive Glass Nanoparticles on C2C12 Cell Viability and Differentiation: Potential for Muscle Tissue Application. ACS Biomater Sci Eng 2022; 8:5273-5283. [PMID: 36379050 PMCID: PMC9748944 DOI: 10.1021/acsbiomaterials.2c00876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022]
Abstract
Mesoporous bioactive glasses (MBGs) exhibit a high surface area and a highly ordered mesoporous structure. MBGs have potential for both hard and soft tissue engineering applications. MBGs may be doped with biologically active ions to tailor their biological activity. Boron is being widely studied as a dopant of bioactive glasses. Recently, research has demonstrated the potential of boron-containing bioactive glasses for muscle regeneration. In this study, boron-containing MBGs, 10B-MBG and 18B-MBG nanoparticles, were produced by a microemulsion-assisted sol-gel approach for potential muscle regeneration applications. First, X-ray diffraction (XRD), Fourier transform infrared (FTIR), and energy-dispersive X-ray spectroscopy (EDX) analyses were conducted to study the chemical structure and composition of the nanoparticles. To examine the nanoparticle morphology, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images were analyzed. Both SEM images and particle size distribution determined by dynamic light scattering (DLS) indicated a decrease of the average particle size after boron doping. TEM images indicated a slit-shaped mesoporous structure of nanoparticles for all compositions. The ζ potential was measured, and a negative surface charge was found for all study groups due to the presence of silanol groups. Cytocompatibility and fluorescence microscopy studies were also carried out. The results indicated that low concentrations (0.1 and 1 mg mL-1) of all MBG nanoparticles led to high viability of C2C12 cells. Fluorescence microscopy images indicated that at lower nanoparticle concentrations (0.1 and 1 mg mL-1), C2C12 cells appeared to differentiate into myotubes, which was indicated by a spindle-shaped morphology. For 10 mg mL-1 concentration of nanoparticles, C2C12 cells had a lower aspect ratio (estimated qualitatively by inspection of the images), which implied a lower degree of differentiation. Boron-doped MBG nanoparticles in reduced concentrations are suitable to induce differentiation of C2C12 cells into myotubes, indicating their potential for applications in muscle tissue repair.
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Affiliation(s)
- Duygu Ege
- Institute
of Biomedical Engineering, Boğaziçi
University, Rasathane Street, Kandilli, İstanbul34684, Turkey
- Department
of Materials Science and Engineering, Institute of Biomaterials, University of Erlangen-Nuremberg, 91058Erlangen, Germany
| | - Qaisar Nawaz
- Department
of Materials Science and Engineering, Institute of Biomaterials, University of Erlangen-Nuremberg, 91058Erlangen, Germany
| | - Ana M. Beltrán
- Departamento
de Ingeniería y Ciencia de los Materiales y del Transporte, Escuela Politécnica Superior, Universidad de
Sevilla, 41011Seville, Spain
| | - Aldo R. Boccaccini
- Department
of Materials Science and Engineering, Institute of Biomaterials, University of Erlangen-Nuremberg, 91058Erlangen, Germany
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3
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Li B, Yang J, Gong Y, Xiao Y, Chen W, Zeng Q, Xu K, Duan Y, Ma H. Effects of age on subcutaneous adipose tissue proteins in Chinese indigenous Ningxiang pig by TMT-labeled quantitative proteomics. J Proteomics 2022; 265:104650. [PMID: 35690344 DOI: 10.1016/j.jprot.2022.104650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/02/2022] [Accepted: 06/04/2022] [Indexed: 10/18/2022]
Abstract
Adipose tissue not only affects meat quality and animal productivity, but also participates in inflammation and immunity. Ningxiang pig is famous for their excellent meat quality, disease resistance and tolerance of roughage. It is not yet well known how proteins in adipose tissue is dynamically regulated during the growth of Ningxiang pig. This report studies the proteomic changes in subcutaneous adipose tissue in Ningxiang pigs to gain a better understanding of the molecular mechanism of fat development during the growth period. By TMT-labeled quantitative proteomic analysis of subcutaneous adipose tissue of 9 purebred Ningxiang pigs of different ages, we identified 2533 unique proteins and 716 differentially abundant proteins (DAPs), of which more than half of the DAPs were concentrated in the 90d-210d period. Retrograde endocannabinoid signaling was only significantly enriched in DAPs of N90d vs N30d, Alcoholism and Graft-versus-host disease were only significantly enriched in DAPs of N210d vs N90d. Proteins related to dilated cardiomyopathy was found to be an important pathway in fat development and lipid metabolism. A variety of novel DAPs involved in maintaining mitochondrial function and cell viability, such as NDUFS6, SDHB, COX5A, ATP5D and TNNT1, which play a role in controlling the prediction networks, may indirectly regulate the development and functional maintenance of adipocytes. SIGNIFICANCE: These age-dependent DAPs discovered in this study may help expand the understanding of the molecular mechanisms of the development, function maintenance and transformation of adipose tissue in Ningxiang pig for developing new strategies for improving meat quality and pig breeding in the future.
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Affiliation(s)
- Biao Li
- College of Animal Husbandry and Veterinary Medicine, Southwest Minzu University, Chengdu 610000, Sichuan, China; Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States
| | - Jinzeng Yang
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States.
| | - Yan Gong
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States
| | - Yu Xiao
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States
| | - Wenwu Chen
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States
| | - Qinghua Zeng
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States
| | - Kang Xu
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agroecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China
| | - Yehui Duan
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agroecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China.
| | - Haiming Ma
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410000, China; Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI, United States.
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Bukhari SNA. An insight into the multifunctional role of ghrelin and structure activity relationship studies of ghrelin receptor ligands with clinical trials. Eur J Med Chem 2022; 235:114308. [PMID: 35344905 DOI: 10.1016/j.ejmech.2022.114308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 02/06/2022] [Accepted: 03/18/2022] [Indexed: 11/30/2022]
Abstract
Ghrelin is a multifunctional gastrointestinal acylated peptide, primarily synthesized in the stomach and regulates the secretion of growth hormone and energy homeostasis. It plays a central role in modulating the diverse biological, physiological and pathological functions in vertebrates. The synthesis of ghrelin receptor ligands after the finding of growth hormone secretagogue developed from Met-enkephalin led to reveal the endogenous ligand ghrelin and the receptors. Subsequently, many peptides, small molecules and peptidomimetics focusing on the ghrelin receptor, GHS-R1a, were derived. In this review, the key features of ghrelin's structure, forms, its bio-physiological functions, pathological roles and therapeutic potential have been highlighted. A few peptidomimetics and pseudo peptide synthetic perspectives have also been discussed to make ghrelin receptor ligands, clinical trials and their success.
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Affiliation(s)
- Syed Nasir Abbas Bukhari
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka, Aljouf, 2014, Saudi Arabia.
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Akalu Y, Molla MD, Dessie G, Ayelign B. Physiological Effect of Ghrelin on Body Systems. Int J Endocrinol 2020; 2020:1385138. [PMID: 32565790 PMCID: PMC7267865 DOI: 10.1155/2020/1385138] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/08/2020] [Accepted: 05/13/2020] [Indexed: 02/06/2023] Open
Abstract
Ghrelin is a relatively novel multifaceted hormone that has been found to exert a plethora of physiological effects. In this review, we found/confirmed that ghrelin has effect on all body systems. It induces appetite; promotes the use of carbohydrates as a source of fuel while sparing fat; inhibits lipid oxidation and promotes lipogenesis; stimulates the gastric acid secretion and motility; improves cardiac performance; decreases blood pressure; and protects the kidneys, heart, and brain. Ghrelin is important for learning, memory, cognition, reward, sleep, taste sensation, olfaction, and sniffing. It has sympatholytic, analgesic, antimicrobial, antifibrotic, and osteogenic effects. Moreover, ghrelin makes the skeletal muscle more excitable and stimulates its regeneration following injury; delays puberty; promotes fetal lung development; decreases thyroid hormone and testosterone; stimulates release of growth hormone, prolactin, glucagon, adrenocorticotropic hormone, cortisol, vasopressin, and oxytocin; inhibits insulin release; and promotes wound healing. Ghrelin protects the body by different mechanisms including inhibition of unwanted inflammation and induction of autophagy. Having a clear understanding of the ghrelin effect in each system has therapeutic implications. Future studies are necessary to elucidate the molecular mechanisms of ghrelin actions as well as its application as a GHSR agonist to treat most common diseases in each system without any paradoxical outcomes on the other systems.
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Affiliation(s)
- Yonas Akalu
- Department of Physiology, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Meseret Derbew Molla
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Gashaw Dessie
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Birhanu Ayelign
- Department of Immunology and Molecular Biology, School of Biomedical and Laboratory Science, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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Novel evidence of ghrelin and growth hormone segretagogue receptor expression by human ocular tissues. ACTA ACUST UNITED AC 2014; 190-191:18-24. [PMID: 24809812 DOI: 10.1016/j.regpep.2014.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 12/28/2022]
Abstract
AIM OF THE STUDY The gastrointestinal peptide hormone ghrelin (Ghr) was discovered in 1999 as the endogenous ligand for the growth hormone secretagogue receptor (GHSR-1a). It is a pleiotropic peptide that modulates a wide spectrum of biological activities, such as growth hormone (GH) release, feeding stimulation, adiposity and cardiovascular actions. The presence of Ghr mRNA in the iris and ciliary body (CB) epithelium was recently demonstrated in animal models, where a possible myorelaxing effect on the iris muscles has been suggested. Based on these observations, the aim of our study was to investigate the Ghr and GHSR-1a expression and localization in the normal human eye. MATERIAL Five different ciliary body/iris samples from normal eyes were subjected to Western blot analysis. Immunohistochemical detection was performed on three enucleated eyes. Twenty aqueous humor (AqH) samples obtained from patients submitted to cataract surgery were analyzed with an ELISA for the presence of Ghr. RESULTS Ghr and GHSR-1a were co-expressed by the pigmented epithelium (PE) of the CB, by the retinal pigmented epithelium (RPE) and by the anterior limiting layer (ALL) of the iris. No reaction was detected at the subepithelial level in the ciliary or pupillae smooth muscle cells. The AqH samples were positive for the presence of Ghr. CONCLUSION This study provides the first evidence that Ghr and GHSR-1a are expressed in the human eye by specific cells. The understanding of the functional role of Ghr at the human eye level needs more efforts and investigation, but a hypothetical action on the GH retinal synthesis and/or on the circadian clock system could be suggested.
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Ghanbari-Niaki A, Jafari A, Moradi M, Kraemer RR. Short-,moderate-, and long-term treadmill training protocols reduce plasma, fundus, but not small intestine ghrelin concentrations in male rats. J Endocrinol Invest 2011; 34:439-43. [PMID: 21183796 DOI: 10.1007/bf03346710] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND It has been suggested that circulating ghrelin levels are upregulated by fasting, hypoglycemic status, and a physical exercise-induced energy deficit. AIM The purpose of the present study was to investigate the timecourse adaptations of the plasma, fundus, and small intestine ghrelin concentrations as well as related hormones and liver ATP levels to 3, 6, and 12 weeks of treadmill endurance running. MATERIAL/SUBJECTS AND METHODS Thirty-nine male Wistar rats (12-14 weeks old) were randomly assigned to 3 control (C3, no.=5; C6, no.=7 and C12, no.=7) and 3 training groups (E3, no.=6; E6, no.=7 and E12, no.=7). The rats in the 3 training groups were exercised on a motor-driven treadmill at 25 m/min (0% grade) for 60 min/day, 5 days/week for 3, 6, and 12 weeks, respectively. The animals were sacrificed 48 h after the last session of each training program and tissues were analyzed. RESULTS Total ghrelin concentrations were significantly (p<0.05) lower in trained rat plasma and fundus tissue after all treadmill endurance running programs. Small intestine ghrelin concentrations remained unchanged. Plasma GH concentrations and liver ATP content were significantly higher in E6 and E12 groups. CONCLUSION Data indicate that as little as 3 weeks of moderate treadmill exercise reduces plasma and fundus total ghrelin concentrations with elevated plasma GH and liver ATP content occurring after 6 and 12 weeks of training. Exercise training-induced improvement of energy source availability and negative feedback from increased GH levels may play a role in reducing plasma and fundus ghrelin levels.
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Affiliation(s)
- A Ghanbari-Niaki
- Exercise Biochemistry Division, Faculty of Physical Education & Sports Sciences, Mazandran University, Babolsar Mazandran, Iran
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8
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Sax B, Nadasy GL, Turi K, Hirschberg K, Furjesz D, Nagy A, Merkely B, Szabo G, Monos E, Kekesi V. Coronary vasoconstrictor effect of ghrelin is not mediated by growth hormone secretagogue receptor 1a type in dogs. Peptides 2011; 32:362-7. [PMID: 21126551 DOI: 10.1016/j.peptides.2010.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/15/2010] [Accepted: 11/15/2010] [Indexed: 11/27/2022]
Abstract
Ghrelin (GHR) is a recently discovered endocrine regulatory peptide of gastrointestinal origin with multiple functions including cardiovascular effects. However, contradictory data are available on the vascular actions of GHR in different organs and species. The aim of this study was to characterize the direct effect of the peptide on the canine coronary bed and to evaluate the role of the growth hormone secretagogue receptor (GHS-R) in the effect of GHR on coronary arterioles. The presence of GHS-R1a and 1b subtypes in canine coronary arterioles was investigated using Western blotting and immunohistochemistry. Responses of coronary arterioles with spontaneous and elevated vascular tone (the latter evoked by the thromboxane mimetic agent U46619, 10(-7)-10(-6)mol/l) to GHR (10(-9)-3×10(-7)nmol/l) were recorded by video-microscopy as changes of vessel diameter. Positive immunostaining for both GHS-R subtypes was found in the wall of intramural arterioles. The microarteriographic study results showed that GHR alone could not elicit any significant effect on vessel diameter of arterioles with spontaneous tone. However, when vascular smooth muscle was preconstricted by the thromboxane mimetic agent U46619, administration of GHR induced further constriction (+31±9% increase in contraction p<0.01). This was not abolished by the specific blockade of GHS-R1a by d-Lys(3)-GHRP-6 (5×10(-6)mol/l). The results suggest that GHR induces tone-dependent constriction of canine coronary arterioles which is mediated by a receptor other than GHS-R1a.
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Affiliation(s)
- Balazs Sax
- Heart Center, Semmelweis University, Budapest, Hungary.
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Katsanos A, Dastiridou A, Georgoulias P, Cholevas P, Kotoula M, Tsironi EE. Plasma and aqueous humour levels of ghrelin in open-angle glaucoma patients. Clin Exp Ophthalmol 2011; 39:324-9. [DOI: 10.1111/j.1442-9071.2010.02463.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Alloatti G, Arnoletti E, Bassino E, Penna C, Perrelli MG, Ghé C, Muccioli G. Obestatin affords cardioprotection to the ischemic-reperfused isolated rat heart and inhibits apoptosis in cultures of similarly stressed cardiomyocytes. Am J Physiol Heart Circ Physiol 2010; 299:H470-81. [DOI: 10.1152/ajpheart.00800.2009] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obestatin, a newly discovered peptide encoded by the ghrelin gene, induces the expression of genes regulating pancreatic β-cell differentiation, insulin biosynthesis, and glucose metabolism. It also activates antiapoptotic signaling pathways such as phosphoinositide 3-kinase (PI3K) and ERK1/2 in pancreatic β-cells and human islets. Since these kinases have been shown to protect against myocardial injury, we sought to investigate whether obestatin would exert cardioprotective effects. Both isolated perfused rat heart and cultured cardiomyocyte models of ischemia-reperfusion (I/R) were used to measure infarct size and cell apoptosis as end points of injury. The presence of specific obestatin receptors on cardiac cells as well as the signaling pathways underlying the obestatin effect were also studied. In the isolated heart, the addition of rat obestatin-(1–23) before ischemia reduced infarct size and contractile dysfunction in a concentration-dependent manner, whereas obestatin-(23–1), a synthetic analog with an inverse aminoacid sequence, was ineffective. The cardioprotective effect of obestatin-(1–23) was observed at concentrations of 10–50 nmol/l and was abolished by inhibiting PI3K or PKC by the addition of wortmannin (100 nmol/l) or chelerythrine, (5 μmol/l), respectively. In rat H9c2 cardiac cells or isolated ventricular myocytes subjected to I/R, 50 nmol/l obestatin-(1–23) reduced cardiomyocyte apoptosis and reduced caspase-3 activation; the antiapoptotic effect was blocked by the inhibition of PKC, PI3K, or ERK1/2 pathways. In keeping with these functional findings, radioreceptor binding results revealed the presence of specific high-affinity obestatin-binding sites, mainly localized on membranes of the ventricular myocardium and cardiomyocytes. Our data suggest that, by acting on specific receptors, obestatin-(1–23) activates PI3K, PKC-ε, PKC-δ, and ERK1/2 signaling and protects cardiac cells against myocardial injury and apoptosis induced by I/R.
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Affiliation(s)
- Giuseppe Alloatti
- Department of Animal and Human Biology,
- Istituto Nazionale per la Ricerca Cardiovascolare, Bologna, Italy
| | - Elisa Arnoletti
- Division of Pharmacology, Department of Anatomy, Pharmacology and Forensic Medicine, and
| | | | - Claudia Penna
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy; and
| | - Maria Giulia Perrelli
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy; and
| | - Corrado Ghé
- Division of Pharmacology, Department of Anatomy, Pharmacology and Forensic Medicine, and
| | - Giampiero Muccioli
- Division of Pharmacology, Department of Anatomy, Pharmacology and Forensic Medicine, and
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Veldhuis JD, Bowers CY. Integrating GHS into the Ghrelin System. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010:879503. [PMID: 20798846 PMCID: PMC2925380 DOI: 10.1155/2010/879503] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/30/2009] [Indexed: 12/21/2022]
Abstract
Oligopeptide derivatives of metenkephalin were found to stimulate growth-hormone (GH) release directly by pituitary somatotrope cells in vitro in 1977. Members of this class of peptides and nonpeptidyl mimetics are referred to as GH secretagogues (GHSs). A specific guanosine triphosphatate-binding protein-associated heptahelical transmembrane receptor for GHS was cloned in 1996. An endogenous ligand for the GHS receptor, acylghrelin, was identified in 1999. Expression of ghrelin and homonymous receptor occurs in the brain, pituitary gland, stomach, endothelium/vascular smooth muscle, pancreas, placenta, intestine, heart, bone, and other tissues. Principal actions of this peptidergic system include stimulation of GH release via combined hypothalamopituitary mechanisms, orexigenesis (appetitive enhancement), insulinostasis (inhibition of insulin secretion), cardiovascular effects (decreased mean arterial pressure and vasodilation), stimulation of gastric motility and acid secretion, adipogenesis with repression of fat oxidation, and antiapoptosis (antagonism of endothelial, neuronal, and cardiomyocyte death). The array of known and proposed interactions of ghrelin with key metabolic signals makes ghrelin and its receptor prime targets for drug development.
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Affiliation(s)
- Johannes D. Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Cyril Y. Bowers
- Division of Endocrinology, Department of Internal Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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Metabolic and cardiovascular effects of ghrelin. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010. [PMID: 20798901 PMCID: PMC2925368 DOI: 10.1155/2010/864342] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 01/16/2010] [Indexed: 01/28/2023]
Abstract
Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, is synthesized as a preprohormone and then proteolytically processed to yield a 28-amino acid peptide. This peptide was originally reported to induce growth hormone release; large evidence, however, has indicated many other physiological activities of ghrelin, including regulation of food intake and energy balance, as well as of lipid and glucose metabolism. Ghrelin receptors have been detected in the hypothalamus and the pituitary, but also in the cardiovascular system, where ghrelin exerts beneficial hemodynamic activities. Ghrelin administration acutely improves endothelial dysfunction by increasing nitric oxide bioavailability and normalizes the altered balance between endothelin-1 and nitric oxide within the vasculature of patients with metabolic syndrome. Other cardiovascular effects of ghrelin include improvement of left ventricular contractility and cardiac output, as well as reduction of arterial pressure and systemic vascular resistance. In addition, antinflammatory and antiapoptotic actions of ghrelin have been reported both in vivo and in vitro. This review summarizes the most recent findings on the metabolic and cardiovascular effects of ghrelin through GH-dependent and -independent mechanisms and the possible role of ghrelin as a therapeutic molecule for treating cardiovascular diseases.
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Dong XY, Xu J, Tang SQ, Li HY, Jiang QY, Zou XT. Ghrelin and its biological effects on pigs. Peptides 2009; 30:1203-11. [PMID: 19463757 DOI: 10.1016/j.peptides.2009.03.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/01/2009] [Accepted: 03/02/2009] [Indexed: 12/23/2022]
Abstract
Ghrelin is a 28 amino acid peptide, which produces its marked effects through binding to the endogenous ligand of the growth hormone secretagogue receptor (GHS-R). Based on the contemporary literatures, it was shown that ghrelin was involved in a series of biological functions including regulation of food intake, body weight, gastrointestinal (GI) motility, hormone secretion, glucose release, cardiovascular functions, enzyme release, cell proliferation and reproduction in pigs through binding to GHS-R 1a or unidentified receptors. It was also observed that ghrelin induced adipocyte and hepatocyte proliferation of primary cultured piglet. In this paper, recent research on ghrelin structure, distribution, GHS-R receptor, biological functions and its regulatory mechanisms for pigs are presented.
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Affiliation(s)
- Xiao-Ying Dong
- College of Yingdong Bioengineering, Shaoguan University, Zhenjiang District, Shaoguan, Guangdong, China
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Ladeiras-Lopes R, Ferreira-Martins J, Leite-Moreira AF. Acute neurohumoral modulation of diastolic function. Peptides 2009; 30:419-25. [PMID: 19028535 DOI: 10.1016/j.peptides.2008.10.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 10/26/2008] [Accepted: 10/27/2008] [Indexed: 02/07/2023]
Abstract
Diastole plays a central role in cardiovascular homeostasis. Its two main determinants, myocardial relaxation and passive properties of the ventricular wall, are nowadays regarded as physiological mechanisms susceptible of active modulation. Furthermore, diastolic dysfunction and heart failure with normal ejection fraction (previously called diastolic heart failure) are two subjects of major clinical relevance and an intense area of research. The role of several neurohumoral mediators like angiotensin-II and endothelin-1 on the modulation of diastolic function was systematically described as having only chronic deleterious effects such as cardiac hypertrophy and fibrosis. However, over the last years a growing body of evidence described a new role for several peptides on the acute modulation of diastolic function. In the acute setting, some of these mediators may have the potential to induce an adaptive cardiac response. In this review, we describe the role of angiotensin-II, endothelin-1, nitric oxide, urotensin-II and ghrelin on the acute modulation of diastolic function, emphasizing its pathophysiological relevance. Only a thorough understanding of diastolic physiology as well as its active modulation, both in the acute and chronic settings, will improve our knowledge on diastolic dysfunction and allow us to solve the enigmas of heart failure with normal ejection fraction.
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Zou CC, Liang L, Zhao ZY. Factors associated with fasting plasma ghrelin levels in children and adolescents. World J Gastroenterol 2008; 14:790-4. [PMID: 18205273 PMCID: PMC2684010 DOI: 10.3748/wjg.14.790] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To measure plasma ghrelin levels in children and adolescents, analyze the associated factors, and investigate the role of ghrelin in obesity, insulin resistance and reproductive physiology.
METHODS: A total of 283 subjects aged 4.8-15.8 year were enrolled. Fasting blood samples were collected and plasma ghrelin levels were measured by radioimmunoassay. Fasting glucose (FG), fasting insulin (FI), baseline testosterone (T), estradiol (E2), prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), serum total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT) and uric acid (UA) were measured. Body mass index (BMI), insulin resistance by homeostasis model (HOMA-IR) and beta cell function by homeostasis model (HOMA-β) were calculated.
RESULTS: The median ghrelin level was 290 ng/L (15.0-1325.0 ng/L). Bivariate correlation analysis showed that ghrelin levels were inversely correlated with BMI, ALT, TG, UA, LH, FI and HOMA-IR (all P < 0.05). No other significant correlation was found between ghrelin levels and age, gender, TC, E2, FSH, PRL, FG and HOMA-β. Stepwise multiple regression analysis showed that only BMI and FI were independent determinants of plasma ghrelin levels in these children and adolescents (P = 0.018 and P = 0.046, respectively), which explained 25.4% of the variance.
CONCLUSION: These data suggest that the lower ghrelin levels in obese subjects may be the result of obesity and hyperinsulinemia, which is very common in obese subjects. Moreover, ghrelin may regulate human reproductive physiology indirectly.
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