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Hage C, Ståhlberg M, Thorvaldsen T, Faxén UL, Pironti G, Webb DL, Hellström PM, Andersson DC, Lund LH. Acyl ghrelin infusion increases circulating growth hormone in patients with heart failure and reduced ejection fraction. Eur J Heart Fail 2023; 25:2093-2095. [PMID: 37655533 DOI: 10.1002/ejhf.3019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/24/2023] [Accepted: 08/29/2023] [Indexed: 09/02/2023] Open
Affiliation(s)
- Camilla Hage
- Unit of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- Karolinska University Hospital, Heart, Vascular and Neuro Theme, Stockholm, Sweden
| | - Marcus Ståhlberg
- Unit of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- Karolinska University Hospital, Heart, Vascular and Neuro Theme, Stockholm, Sweden
| | - Tonje Thorvaldsen
- Unit of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- Karolinska University Hospital, Heart, Vascular and Neuro Theme, Stockholm, Sweden
| | - Ulrika L Faxén
- Unit of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
| | - Gianluigi Pironti
- Unit of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Dominic-Luc Webb
- Department of Medical Sciences, Gastroenterology and Hepatology, Uppsala University, Uppsala, Sweden
| | - Per M Hellström
- Department of Medical Sciences, Gastroenterology and Hepatology, Uppsala University, Uppsala, Sweden
| | - Daniel C Andersson
- Karolinska University Hospital, Heart, Vascular and Neuro Theme, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Lars H Lund
- Unit of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- Karolinska University Hospital, Heart, Vascular and Neuro Theme, Stockholm, Sweden
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2
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Jiang B, Wang M, Li X, Ren P, Li G, Wang Y, Wang L, Li X, Yang D, Qin L, Xin S. Hexarelin attenuates abdominal aortic aneurysm formation by inhibiting SMC phenotype switch and inflammasome activation. Microvasc Res 2022; 140:104280. [PMID: 34856183 DOI: 10.1016/j.mvr.2021.104280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 11/11/2021] [Accepted: 11/13/2021] [Indexed: 01/15/2023]
Abstract
Hexarelin, a synthetic growth hormone-releasing peptide, is shown to be protective in cardiovascular diseases such as myocardial infraction and atherosclerosis. However, the functional role of hexarelin in abdominal aortic aneurysm (AAA) remains undefined. The present study determined the effect of hexarelin administration (200 μg/kg twice per day) in a mouse model of elastase-induced abdominal aortic aneurysm. Echocardiography and in situ pictures showed hexarelin decreased infrarenal aorta diameter. Histology staining showed elastin degradation was improved in hexarelin-treated group. Hexarelin rescued smooth muscle cell contractile phenotype with increased α-SMA and decreased MMP2. Furthermore, hexarelin inhibited inflammatory cell infiltration, NLRP3 inflammasome activation and IL-18 production. Particularly, hexarelin suppressed NF-κB signaling pathway which is a key initiator of inflammatory response. These results demonstrated that hexarelin attenuated AAA development by inhibiting SMC phenotype switch and NF-κB signaling mediated inflammatory response.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/pharmacology
- Aorta, Abdominal/drug effects
- Aorta, Abdominal/immunology
- Aorta, Abdominal/metabolism
- Aorta, Abdominal/pathology
- Aortic Aneurysm, Abdominal/immunology
- Aortic Aneurysm, Abdominal/metabolism
- Aortic Aneurysm, Abdominal/pathology
- Aortic Aneurysm, Abdominal/prevention & control
- Cell Plasticity/drug effects
- Cytokines/metabolism
- Disease Models, Animal
- Inflammasomes/antagonists & inhibitors
- Inflammasomes/metabolism
- Male
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/immunology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/immunology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- NF-kappa B/metabolism
- NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors
- NLR Family, Pyrin Domain-Containing 3 Protein/metabolism
- Oligopeptides/pharmacology
- Phenotype
- Signal Transduction
- Vascular Remodeling/drug effects
- Mice
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Affiliation(s)
- Bo Jiang
- Department of Vascular Surgery, The First Hospital of China Medical University, Key Laboratory of Pathogenesis, Prevention and Therapeutics of Aortic Aneurysm, Shenyang, Liaoning 110001, China
| | - Mo Wang
- Department of Surgery, Yale School of Medicine, New Haven, CT 06519, USA
| | - Xue Li
- Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, China
| | - Pengwei Ren
- Department of Surgery, Yale School of Medicine, New Haven, CT 06519, USA
| | - Guangxin Li
- Department of Breast and Thyroid Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, China
| | - Yuqi Wang
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06520, USA; Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
| | - Lei Wang
- Department of Vascular Surgery, The First Hospital of China Medical University, Key Laboratory of Pathogenesis, Prevention and Therapeutics of Aortic Aneurysm, Shenyang, Liaoning 110001, China
| | - Xuan Li
- Department of Vascular Surgery, The First Hospital of China Medical University, Key Laboratory of Pathogenesis, Prevention and Therapeutics of Aortic Aneurysm, Shenyang, Liaoning 110001, China
| | - Dong Yang
- Department of Vascular Surgery, The First Hospital of China Medical University, Key Laboratory of Pathogenesis, Prevention and Therapeutics of Aortic Aneurysm, Shenyang, Liaoning 110001, China
| | - Lingfeng Qin
- Department of Surgery, Yale School of Medicine, New Haven, CT 06519, USA.
| | - Shijie Xin
- Department of Vascular Surgery, The First Hospital of China Medical University, Key Laboratory of Pathogenesis, Prevention and Therapeutics of Aortic Aneurysm, Shenyang, Liaoning 110001, China.
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3
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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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4
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Gupta S, Mitra A. Heal the heart through gut (hormone) ghrelin: a potential player to combat heart failure. Heart Fail Rev 2020; 26:417-435. [PMID: 33025414 DOI: 10.1007/s10741-020-10032-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 12/17/2022]
Abstract
Ghrelin, a small peptide hormone (28 aa), secreted mainly by X/A-like cells of gastric mucosa, is also locally produced in cardiomyocytes. Being an orexigenic factor (appetite stimulant), it promotes release of growth hormone (GH) and exerts diverse physiological functions, viz. regulation of energy balance, glucose, and/or fat metabolism for body weight maintenance. Interestingly, administration of exogenous ghrelin significantly improves cardiac functions in CVD patients as well as experimental animal models of heart failure. Ghrelin ameliorates pathophysiological condition of the heart in myocardial infarction, cardiac hypertrophy, fibrosis, cachexia, and ischemia reperfusion injury. This peptide also exerts significant impact at the level of vasculature leading to lowering high blood pressure and reversal of endothelial dysfunction and atherosclerosis. However, the molecular mechanism of actions elucidating the healing effects of ghrelin on the cardiovascular system is still a matter of conjecture. Some experimental data indicate its beneficial effects via complex cellular cross talks between autonomic nervous system and cardiovascular cells, some other suggest more direct receptor-mediated molecular actions via autophagy or ionotropic regulation and interfering with apoptotic and inflammatory pathways of cardiomyocytes and vascular endothelial cells. Here, in this review, we summarise available recent data to encourage more research to find the missing links of unknown ghrelin receptor-mediated pathways as we see ghrelin as a future novel therapy in cardiovascular protection.
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Affiliation(s)
- Shreyasi Gupta
- Department of Zoology, Triveni Devi Bhalotia College, Raniganj, Paschim Bardhaman, 713347, India
| | - Arkadeep Mitra
- Department of Zoology, City College , 102/1, Raja Rammohan Sarani, Kolkata, 700009, India.
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5
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Growth Hormone Secretagogues and the Regulation of Calcium Signaling in Muscle. Int J Mol Sci 2019; 20:ijms20184361. [PMID: 31491959 PMCID: PMC6769538 DOI: 10.3390/ijms20184361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 12/22/2022] Open
Abstract
Growth hormone secretagogues (GHS) are a family of synthetic molecules, first discovered in the late 1970s for their ability to stimulate growth hormone (GH) release. Many effects of GHS are mediated by binding to GHS-R1a, the receptor for the endogenous hormone ghrelin, a 28-amino acid peptide isolated from the stomach. Besides endocrine functions, both ghrelin and GHS are endowed with some relevant extraendocrine properties, including stimulation of food intake, anticonvulsant and anti-inflammatory effects, and protection of muscle tissue in different pathological conditions. In particular, ghrelin and GHS inhibit cardiomyocyte and endothelial cell apoptosis and improve cardiac left ventricular function during ischemia–reperfusion injury. Moreover, in a model of cisplatin-induced cachexia, GHS protect skeletal muscle from mitochondrial damage and improve lean mass recovery. Most of these effects are mediated by GHS ability to preserve intracellular Ca2+ homeostasis. In this review, we address the muscle-specific protective effects of GHS mediated by Ca2+ regulation, but also highlight recent findings of their therapeutic potential in pathological conditions characterized by skeletal or cardiac muscle impairment.
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6
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Sullivan R, Randhawa VK, Stokes A, Wu D, Lalonde T, Kiaii B, Luyt L, Wisenberg G, Dhanvantari S. Dynamics of the Ghrelin/Growth Hormone Secretagogue Receptor System in the Human Heart Before and After Cardiac Transplantation. J Endocr Soc 2019; 3:748-762. [PMID: 30937420 PMCID: PMC6438351 DOI: 10.1210/js.2018-00393] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/11/2019] [Indexed: 12/14/2022] Open
Abstract
Currently, the early preclinical detection of left ventricular dysfunction is difficult because biomarkers are not specific for the cardiomyopathic process. The underlying molecular mechanisms leading to heart failure remain elusive, highlighting the need for identification of cardiac-specific markers. The growth hormone secretagogue receptor (GHSR) and its ligand ghrelin are present in cardiac tissue and are known to contribute to myocardial energetics. Here, we examined tissue ghrelin-GHSR levels as specific markers of cardiac dysfunction in patients who underwent cardiac transplantation. Samples of cardiac tissue were obtained from 10 patients undergoing cardiac transplant at the time of organ harvesting and during serial posttransplant biopsies. Quantitative fluorescence microscopy using a fluorescent ghrelin analog was used to measure levels of GHSR, and immunofluorescence was used to measure levels of ghrelin, B-type natriuretic peptide (BNP), and tissue markers of cardiomyocyte contractility and growth. GHSR and ghrelin expression levels were highly variable in the explanted heart, less in the grafted heart biopsies. GHSR and ghrelin were strongly positively correlated, and both markers were negatively correlated with left ventricular ejection fraction. Ghrelin had stronger positive correlations than BNP with the signaling markers for contractility and growth. These data suggest that GHSR-ghrelin have potential use as an integrated marker of cardiac dysfunction. Interestingly, tissue ghrelin appeared to be a more sensitive indicator than BNP to the biochemical processes that are characteristic of heart failure. This work allows for further use of ghrelin-GHSR to interrogate cardiac-specific biochemical mechanisms in preclinical stages of heart failure (HF).
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Affiliation(s)
- Rebecca Sullivan
- Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Varinder K Randhawa
- Cardiac Imaging Research, Lawson Health Research Institute, London, Ontario, Canada
| | - Anne Stokes
- Metabolism and Diabetes, Lawson Health Research Institute, London, Ontario, Canada
| | - Derek Wu
- Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Tyler Lalonde
- Chemistry, Western University, London, Ontario, Canada
| | - Bob Kiaii
- Cardiac Surgery, Western University, London, Ontario, Canada
| | - Leonard Luyt
- Chemistry, Western University, London, Ontario, Canada
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada
- Department of Oncology, London Regional Cancer Program, Western University, London, Ontario, Canada
| | - Gerald Wisenberg
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
| | - Savita Dhanvantari
- Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
- Metabolism and Diabetes, Lawson Health Research Institute, London, Ontario, Canada
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
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7
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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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8
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Makepeace CM, Suarez-Pierre A, Kanter EM, Schuessler RB, Nichols CG, Lawton JS. Superior diastolic function with K ATP channel opener diazoxide in a novel mouse Langendorff model. J Surg Res 2018; 227:186-193. [PMID: 29804852 DOI: 10.1016/j.jss.2018.02.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/11/2018] [Accepted: 02/14/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND Adenosine triphosphate-sensitive potassium (KATP) channel openers have been found to be cardioprotective in multiple animal models via an unknown mechanism. Mouse models allow genetic manipulation of KATP channel components for the investigation of this mechanism. Mouse Langendorff models using 30 min of global ischemia are known to induce measurable myocardial infarction and injury. Prolongation of global ischemia in a mouse Langendorff model could allow the determination of the mechanisms involved in KATP channel opener cardioprotection. METHODS Mouse hearts (C57BL/6) underwent baseline perfusion with Krebs-Henseleit buffer (30 min), assessment of function using a left ventricular balloon, delivery of test solution, and prolonged global ischemia (90 min). Hearts underwent reperfusion (30 min) and functional assessment. Coronary flow was measured using an inline probe. Test solutions included were as follows: hyperkalemic cardioplegia alone (CPG, n = 11) or with diazoxide (CPG + DZX, n = 12). RESULTS Although the CPG + DZX group had greater percent recovery of developed pressure and coronary flow, this was not statistically significant. Following a mean of 74 min (CPG) and 77 min (CPG + DZX), an additional increase in end-diastolic pressure was noted (plateau), which was significantly higher in the CPG group. Similarly, the end-diastolic pressure (at reperfusion and at the end of experiment) was significantly higher in the CPG group. CONCLUSIONS Prolongation of global ischemia demonstrated added benefit when DZX was added to traditional hyperkalemic CPG. This model will allow the investigation of DZX mechanism of cardioprotection following manipulation of targeted KATP channel components. This model will also allow translation to prolonged ischemic episodes associated with cardiac surgery.
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Affiliation(s)
- Carol M Makepeace
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Alejandro Suarez-Pierre
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Evelyn M Kanter
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri; Center for the Investigation of Membrane Excitability Diseases (CIMED), Washington University School of Medicine, St. Louis, Missouri
| | - Jennifer S Lawton
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
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Zhang X, Qu L, Chen L, Chen C. Improvement of cardiomyocyte function by in vivo hexarelin treatment in streptozotocin-induced diabetic rats. Physiol Rep 2018; 6:e13612. [PMID: 29446246 PMCID: PMC5812882 DOI: 10.14814/phy2.13612] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/12/2018] [Accepted: 01/16/2018] [Indexed: 01/27/2023] Open
Abstract
Diabetic cardiomyopathy is characterized by diastolic and systolic cardiac dysfunction, yet no therapeutic drug to specifically treat it. Hexarelin has been demonstrated to improve heart function in various types of cardiomyopathy via its receptor GHS-R. This experiment aims to test the effect of hexarelin on cardiomyocytes under experimental diabetes. Streptozotocin (STZ, 65 mg/kg)-induced diabetic rat model was employed with vehicle injection group as control. Daily hexarelin (100 μg/kg) treatment was performed for 2 weeks after 4-week STZ-induced diabetes. Cardiomyocytes were isolated by enzyme treatment under O2 -saturated perfusion for single-cell shortening, [Ca2+ ]i transient, and electrophysiology recordings. GHS-R expression and apoptosis-related signaling proteins Bax, Bcl-2, caspase-3 and 9, were assessed by western blot. Experimental data demonstrated a reduced cell contraction and relaxation in parallel with depressed rise and fall of [Ca2+ ]i transients in diabetic cardiomyocytes. Hexarelin reversed the changes in both contraction and [Ca2+ ]i . Action potential duration and transient outward potassium current (Ito ) density were dramatically increased in diabetic cardiomyocytes and hexarelin treatment reverse such changes. Upregulated GHS receptor (GHS-R) expression was observed in both control and diabetic groups after hexarelin treatment, which also caused antiapoptotic changes of Bax, Bcl-2, caspase-3 and 9 expression. In STZ-induced diabetic rats, hexarelin is able to improve cardiomyocyte function through recovery of Ito K+ currents, intracellular Ca2+ homeostasis and antiapoptotic signaling pathways.
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Affiliation(s)
- Xinli Zhang
- School of Biomedical SciencesUniversity of QueenslandSt LuciaBrisbaneQueenslandAustralia
| | - Linbing Qu
- State Key Laboratories of Respiratory DiseasesGuangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhouChina
| | - Ling Chen
- State Key Laboratories of Respiratory DiseasesGuangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhouChina
| | - Chen Chen
- School of Biomedical SciencesUniversity of QueenslandSt LuciaBrisbaneQueenslandAustralia
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10
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Eid RA, Alkhateeb MA, Eleawa S, Al-Hashem FH, Al-Shraim M, El-Kott AF, Zaki MSA, Dallak MA, Aldera H. Cardioprotective effect of ghrelin against myocardial infarction-induced left ventricular injury via inhibition of SOCS3 and activation of JAK2/STAT3 signaling. Basic Res Cardiol 2018; 113:13. [PMID: 29392420 DOI: 10.1007/s00395-018-0671-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/22/2018] [Indexed: 11/27/2022]
Abstract
The molecular mechanisms through which ghrelin exerts its cardioprotective effects during cardiac remodeling post-myocardial infarction (MI) are poorly understood. The aim of this study was to investigate whether the cardioprotection mechanisms are mediated by modulation of JAK/STAT signaling and what triggers this modulation. Rats were divided into six groups (n = 12/group): control, sham, sham + ghrelin (100 µg/kg, s.c., daily, starting 1 day post-MI), MI, MI+ ghrelin, and MI+ ghrelin+ AG490, a potent JAK2 inhibitor (5 mg/kg, i.p., daily). All treatments were administered for 3 weeks. Administration of ghrelin to MI rats improved left ventricle (LV) architecture and restored cardiac contraction. In remote non-infarcted areas of MI rats, ghrelin reduced cardiac inflammation and lipid peroxidation and enhanced antioxidant enzymatic activity. In addition, independent of the growth factor/insulin growth factor-1 (GF/IGF-1) axis, ghrelin significantly increased the phosphorylation of JAK2 and Tyr702 and Ser727 residues of STAT3 and inhibited the phosphorylation of JAK1 and Tyr701 and Ser727 residues of STAT1, simultaneously increasing the expression of BCL-2 and decreasing in the expression of BAX, cleaved CASP3, and FAS. This effect coincided with decreased expression of SOCS3. All these beneficial effects of ghrelin, except its inhibitory action on IL-6 expression, were partially and significantly abolished by the co-administration of AG490. In conclusion, the cardioprotective effect of ghrelin against MI-induced LV injury is exerted via activation of JAK2/STAT3 signaling and inhibition of STAT1 signaling. These effects were independent of the GF/IGF-1 axis and could be partially mediated via inhibition of cardiac IL-6.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Cardiovascular Agents/administration & dosage
- Disease Models, Animal
- Ghrelin/administration & dosage
- Heart Ventricles/drug effects
- Heart Ventricles/enzymology
- Heart Ventricles/pathology
- Heart Ventricles/physiopathology
- Interleukin-6/metabolism
- Janus Kinase 2/metabolism
- Male
- Myocardial Infarction/drug therapy
- Myocardial Infarction/enzymology
- Myocardial Infarction/pathology
- Myocardial Infarction/physiopathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Oxidative Stress/drug effects
- Rats, Sprague-Dawley
- STAT1 Transcription Factor/metabolism
- STAT3 Transcription Factor/metabolism
- Signal Transduction/drug effects
- Suppressor of Cytokine Signaling 3 Protein/metabolism
- Ventricular Dysfunction, Left/enzymology
- Ventricular Dysfunction, Left/pathology
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Dysfunction, Left/prevention & control
- Ventricular Function, Left/drug effects
- Ventricular Remodeling/drug effects
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Affiliation(s)
- Refaat A Eid
- Department of Pathology, College of Medicine, King Khalid University, Abha, 61421, Saudi Arabia.
| | - Mahmoud A Alkhateeb
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, 14611, Saudi Arabia
| | - Samy Eleawa
- College of Health Sciences, Applied Medical Sciences Department, PAAET, Shuwaikh, Kuwait
| | - Fahaid H Al-Hashem
- Department of Physiology, College of Medicine, King Khalid University, P.O. Box 641, Abha, 61421, Saudi Arabia
| | - Mubarak Al-Shraim
- Department of Pathology, College of Medicine, King Khalid University, Abha, 61421, Saudi Arabia
| | - Attalla Farag El-Kott
- Department of Biology, College of Science, King Khalid University, P.O. Box 641, Abha, 61421, Saudi Arabia
| | - Mohamed Samir Ahmed Zaki
- Department of Anatomy, College of Medicine, King Khalid University, P.O. Box 641, Abha, 61421, Saudi Arabia
| | - Mohammad A Dallak
- Department of Physiology, College of Medicine, King Khalid University, P.O. Box 641, Abha, 61421, Saudi Arabia
| | - Hussain Aldera
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, 14611, Saudi Arabia
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Wang Q, Lin P, Li P, Feng L, Ren Q, Xie X, Xu J. Ghrelin protects the heart against ischemia/reperfusion injury via inhibition of TLR4/NLRP3 inflammasome pathway. Life Sci 2017; 186:50-58. [PMID: 28782532 DOI: 10.1016/j.lfs.2017.08.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 08/03/2017] [Accepted: 08/03/2017] [Indexed: 10/19/2022]
Abstract
AIMS The aim of this study was to investigate the cardioprotective effects of ghrelin against myocardial ischemia/reperfusion (I/R) injury and the underlying mechanism. MAIN METHODS Sprague-Dawley rats were randomized into Sham, I/R and I/R+ghrelin groups. After 30 minutes ischemia, ghrelin (8nmol/kg) was injected intraperitoneally at the time of reperfusion in the I/R+ghrelin group. Then hemodynamic parameters were observed at 24h after reperfusion. KEY FINDINGS Ghrelin exhibited dramatic improvement in cardiac functions, as manifested by increased LVSP and ±dP/dtmax and decreased LVDP. At 24h after reperfusion, ghrelin significantly attenuated the myocardial infarction area and apoptosis, accompanied with a decrease in the levels of the myocyte injury marker enzymes. Oxidative stress injury and inflammatory response were also relieved by ghrelin. Western blot showed that the expression of TLR4, NLRP3, and caspase-1 were obviously increased in I/R group, while ghrelin significantly inhibited the I/R-induced TLR4, NLRP3, and caspase-1 expression. Ghrelin could inhibit the increased protein levels of NLRP3, caspase-1, and IL-1β induced by lipopolysacharide in primary cultured cardiomyocytes of neonatal rats. SIGNIFICANCE Ghrelin protected the heart against I/R injury by inhibiting oxidative stress and inflammation via TLR4/NLRP3 signaling pathway. Our results might provide new strategy and target for treatment of myocardial ischemia/reperfusion injury.
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Affiliation(s)
- Qin Wang
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China
| | - Ping Lin
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China.
| | - Peng Li
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China
| | - Li Feng
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China
| | - Qian Ren
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China
| | - Xiaofeng Xie
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China
| | - Jing Xu
- Department of Geriatrics, The 3rd Hospital of Hangzhou, Hangzhou, China
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Abstract
OBJECTIVE Ghrelin is a polypeptide that is closely associated with many cardiovascular diseases, such as hypertension, atherosclerosis, and heart failure. This article aims to understand the expression of ghrelin in patients with atrial fibrillation (AF). METHODS A total of 182 patients with non-valvular heart diseases were recruited, among whom 92 had AF and 90 had sinus arrhythmia (SA). The serum ghrelin amount was tested by the ELASA method. Moreover, blood sugar, lipids, liver function, and renal function were tested. All recruited patients underwent echocardiographic examination following admission. Three cardiac cycles were observed under continuous exhalation. The left atrial diameter (LAD) and the left ventricular ejection fraction (LVEF) were measured and averaged. Patients with AF received conventional treatment, and the aforementioned parameters were re-measured after 8 weeks. The results were statistically analyzed. RESULTS The serum ghrelin level in the patients in the AF group (199.55±79.59 pg/mL) was lower than that in the patients in the SA group (313.89±71.13 pg/mL, p<0.01), whereas the serum ghrelin level in those in the paroxysmal AF group (224.44±72.33 pg/mL) was higher than that in those in the persistent AF group (176.00±79.88 pg/mL, p<0.01). There was a positive correlation between the serum ghrelin level and LVEF in the patients in the AF group (r=0.704, p=0.046). After treatment, the serum ghrelin level and LVEF in the patients in the AF group significantly increased, whereas LAD decreased. CONCLUSION The serum ghrelin level in patients with AF was reduced, and after treatment, it significantly increased. There was a positive correlation between the serum ghrelin level and LVEF in the patients in the AF group.
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Berlanga-Acosta J, Abreu-Cruz A, Herrera DGDB, Mendoza-Marí Y, Rodríguez-Ulloa A, García-Ojalvo A, Falcón-Cama V, Hernández-Bernal F, Beichen Q, Guillén-Nieto G. Synthetic Growth Hormone-Releasing Peptides (GHRPs): A Historical Appraisal of the Evidences Supporting Their Cytoprotective Effects. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2017; 11:1179546817694558. [PMID: 28469491 PMCID: PMC5392015 DOI: 10.1177/1179546817694558] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 08/19/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND Growth hormone-releasing peptides (GHRPs) constitute a group of small synthetic peptides that stimulate the growth hormone secretion and the downstream axis activity. Mounting evidences since the early 1980s delineated unexpected pharmacological cardioprotective and cytoprotective properties for the GHRPs. However, despite intense basic pharmacological research, alternatives to prevent cell and tissue demise before lethal insults have remained as an empty niche in the clinical armamentarium. Here, we have rigorously reviewed the investigational development of GHRPs and their clinical niching perspectives. METHODOLOGY PubMed/MEDLINE databases, including original research and review articles, were explored. The search design was date escalated from 1980 and included articles in English only. RESULTS AND CONCLUSIONS GHRPs bind to two different receptors (GHS-R1a and CD36), which redundantly or independently exert relevant biological effects. GHRPs' binding to CD36 activates prosurvival pathways such as PI-3K/AKT1, thus reducing cellular death. Furthermore, GHRPs decrease reactive oxygen species (ROS) spillover, enhance the antioxidant defenses, and reduce inflammation. These cytoprotective abilities have been revealed in cardiac, neuronal, gastrointestinal, and hepatic cells, representing a comprehensive spectrum of protection of parenchymal organs. Antifibrotic effects have been attributed to some of the GHRPs by counteracting fibrogenic cytokines. In addition, GHRP family members have shown a potent myotropic effect by promoting anabolia and inhibiting catabolia. Finally, GHRPs exhibit a broad safety profile in preclinical and clinical settings. Despite these fragmented lines incite to envision multiple pharmacological uses for GHRPs, especially as a myocardial reperfusion damage-attenuating candidate, this family of "drugable" peptides awaits for a definitive clinical niche.
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Affiliation(s)
| | - Angel Abreu-Cruz
- Cardiology Unit, Center for Medical and Surgical Research, Siboney, Playa, Havana, Cuba
| | | | - Yssel Mendoza-Marí
- Center for Genetic Engineering and Biotechnology, Cubanacán, Playa, Havana, Cuba
| | | | - Ariana García-Ojalvo
- Center for Genetic Engineering and Biotechnology, Cubanacán, Playa, Havana, Cuba
| | - Viviana Falcón-Cama
- Center for Genetic Engineering and Biotechnology, Cubanacán, Playa, Havana, Cuba
| | | | - Qu Beichen
- Xinkexian Biological Technology Co., Ltd, Haidian District, Beijing, China
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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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Huang J, Li Y, Zhang J, Liu Y, Lu Q. The Growth Hormone Secretagogue Hexarelin Protects Rat Cardiomyocytes From in vivo Ischemia/Reperfusion Injury Through Interleukin-1 Signaling Pathway. Int Heart J 2017; 58:257-263. [DOI: 10.1536/ihj.16-241] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Jiannan Huang
- Department of Cardiology, The Second Hospital of Shandong University
- Department of Cardiology, The Central Hospital of Zibo City
| | - Yi Li
- Obstetric Genetic Disease Laboratory, Maternal and Child Health Hospital of Zibo City
| | - Juan Zhang
- Department of Cardiology, The Central Hospital of Zibo City
| | - Yusheng Liu
- Department of Cardiology, The Second Hospital of Shandong University
| | - Qinghua Lu
- Department of Cardiology, The Second Hospital of Shandong University
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Zhao Y, Zhang X, Chen J, Lin C, Shao R, Yan C, Chen C. Hexarelin Protects Rodent Pancreatic Β-Cells Function from Cytotoxic Effects of Streptozotocin Involving Mitochondrial Signalling Pathways In Vivo and In Vitro. PLoS One 2016; 11:e0149730. [PMID: 26918825 PMCID: PMC4769129 DOI: 10.1371/journal.pone.0149730] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 02/04/2016] [Indexed: 01/25/2023] Open
Abstract
Mitochondrial functions are crucial for pancreatic β-cell survival and glucose-induced insulin secretion. Hexarelin (Hex) is a synthetic small peptide ghrelin analogue, which has been shown to protect cardiomyocytes from the ischemia-reperfusion process. In this study, we used in vitro and in vivo models of streptozotocin (STZ)-induced β-cell damage to study the protective effect of Hex and the associated mechanisms. We found that STZ produced a cytotoxic effect in a dose- and time-dependent manner in MIN6 cells (a mouse β-cell line). Hex (1.0 μM) decreased the STZ-induced damage in β-cells. Rhodamine 123 assay and superoxide DHE production assay revealed that Hex ameliorated STZ-induced mitochondrial damage and excessive superoxide activity in β-cells. In addition, Hex significantly reduced STZ-induced expression of cleaved Caspases-3, Caspases-9 and the ratio of pro-apoptotic protein Bax to anti-apoptotic protein Bcl-2 in MIN6 cells. We further examined the in vivo effect of Hex in a rat model of type 1 diabetes induced by STZ injection. Hex ameliorated STZ-induced decrease in plasma insulin and protected the structure of islets from STZ-induced disruption. Hex also ameliorated STZ-induced expression of cleaved Caspase-9 and the Bax in β-cells. In conclusion, our data indicate that Hex is able to protects β-cell mass from STZ-caused cytotoxic effects involving mitochondrial pathways in vitro and in vivo. Hex may serve as a potential protective agent for the management of diabetes.
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Affiliation(s)
- Yan Zhao
- Institute of Basic Medicine Science, Xi'an Medical University, Xi'an, China
- Department of Forensic Science, School of Medicine, Xi’an Jiaotong University, Xi’an, China
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Xinli Zhang
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Jiezhong Chen
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Chao Lin
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Renfu Shao
- Gene Cology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia
| | - Chunxia Yan
- Department of Forensic Science, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Chen Chen
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
- * E-mail:
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Junqueira A, Cicogna AC, Engel LE, Aldá MA, de Tomasi LC, Giuffrida R, Giometti IC, Freire APCF, Aguiar AF, Pacagnelli FL. Effects of Growth Hormone on Cardiac Remodeling During Resistance Training in Rats. Arq Bras Cardiol 2015; 106:18-25. [PMID: 26647722 PMCID: PMC4728591 DOI: 10.5935/abc.20160003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/04/2015] [Indexed: 11/30/2022] Open
Abstract
Background Although the beneficial effects of resistance training (RT) on the cardiovascular
system are well established, few studies have investigated the effects of the
chronic growth hormone (GH) administration on cardiac remodeling during an RT
program. Objective To evaluate the effects of GH on the morphological features of cardiac remodeling
and Ca2+ transport gene expression in rats submitted to RT. Methods Male Wistar rats were divided into 4 groups (n = 7 per group): control (CT), GH,
RT and RT with GH (RTGH). The dose of GH was 0.2 IU/kg every other day for 30
days. The RT model used was the vertical jump in water (4 sets of 10 jumps, 3
bouts/wk) for 30 consecutive days. After the experimental period, the following
variables were analyzed: final body weight (FBW), left ventricular weight (LVW),
LVW/FBW ratio, cardiomyocyte cross-sectional area (CSA), collagen fraction,
creatine kinase muscle-brain fraction (CK-MB) and gene expressions of SERCA2a,
phospholamban (PLB) and ryanodine (RyR). Results There was no significant (p > 0.05) difference among groups for FBW, LVW,
LVW/FBW ratio, cardiomyocyte CSA, and SERCA2a, PLB and RyR gene expressions. The
RT group showed a significant (p < 0.05) increase in collagen fraction compared
to the other groups. Additionally, the trained groups (RT and RTGH) had greater
CK-MB levels compared to the untrained groups (CT and GH). Conclusion GH may attenuate the negative effects of RT on cardiac remodeling by counteracting
the increased collagen synthesis, without affecting the gene expression that
regulates cardiac Ca2+ transport.
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Mosa RMH, Zhang Z, Shao R, Deng C, Chen J, Chen C. Implications of ghrelin and hexarelin in diabetes and diabetes-associated heart diseases. Endocrine 2015; 49:307-23. [PMID: 25645463 DOI: 10.1007/s12020-015-0531-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/12/2015] [Indexed: 02/07/2023]
Abstract
Ghrelin and its synthetic analog hexarelin are specific ligands of growth hormone secretagogue (GHS) receptor. GHS have strong growth hormone-releasing effect and other neuroendocrine activities such as stimulatory effects on prolactin and adrenocorticotropic hormone secretion. Recently, several studies have reported other beneficial functions of GHS that are independent of GH. Ghrelin and hexarelin, for examples, have been shown to exert GH-independent cardiovascular activity. Hexarelin has been reported to regulate peroxisome proliferator-activated receptor gamma (PPAR-γ) in macrophages and adipocytes. PPAR-γ is an important regulator of adipogenesis, lipid metabolism, and insulin sensitization. Ghrelin also shows protective effects on beta cells against lipotoxicity through activation of phosphatidylinositol-3 kinase/protein kinase B, c-Jun N-terminal kinase (JNK) inhibition, and nuclear exclusion of forkhead box protein O1. Acylated ghrelin (AG) and unacylated ghrelin (UAG) administration reduces glucose levels and increases insulin-producing beta cell number, and insulin secretion in pancreatectomized rats and in newborn rats treated with streptozotocin, suggesting a possible role of GHS in pancreatic regeneration. Therefore, the discovery of GHS has opened many new perspectives in endocrine, metabolic, and cardiovascular research areas, suggesting the possible therapeutic application in diabetes and diabetic complications especially diabetic cardiomyopathy. Here, we review the physiological roles of ghrelin and hexarelin in the protection and regeneration of beta cells and their roles in the regulation of insulin release, glucose, and fat metabolism and present their potential therapeutic effects in the treatment of diabetes and diabetic-associated heart diseases.
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Khatib MN, Shankar A, Kirubakaran R, Agho K, Simkhada P, Gaidhane S, Saxena D, B U, Gode D, Gaidhane A, Zahiruddin SQ. Effect of ghrelin on mortality and cardiovascular outcomes in experimental rat and mice models of heart failure: a systematic review and meta-analysis. PLoS One 2015; 10:e0126697. [PMID: 26016489 PMCID: PMC4446297 DOI: 10.1371/journal.pone.0126697] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
BACKGROUND Heart failure (HF) continues to be a challenging condition in terms of prevention and management of the disease. Studies have demonstrated various cardio-protective effects of Ghrelin. The aim of the study is to determine the effect of Ghrelin on mortality and cardiac function in experimental rats/mice models of HF. METHODS Data sources: PUBMED, Scopus. We searched the Digital Dissertations and conference proceedings on Web of Science. Search methods: We systematically searched for all controlled trials (upto November 2014) which assessed the effects of Ghrelin (irrespective of dose, form, frequency, duration and route of administration) on mortality and cardiac function in rats/ mice models of HF. Ghrelin administration irrespective of dose, form, frequency, duration and route of administration. Data collection and analysis: Two authors independently assessed each abstract for eligibility and extracted data on characteristics of the experimental model used, intervention and outcome measures. We assessed the methodological quality by SYRCLE's risk of bias tool for all studies and the quality of evidence by GRADEpro. We performed meta-analysis using RevMan 5.3. RESULTS A total of 325 animals (rats and mice) were analyzed across seven studies. The meta-analysis revealed that the mortality in Ghrelin group was 31.1% and in control group was 40% (RR 0.83, 95% CI 0.46 to 1.47) i.e Ghrelin group had 68 fewer deaths per 1000 (from 216 fewer to 188 more) as compared to the control group. The meta-analysis reveals that the heart rate in rats/mice on Ghrelin was higher (MD 13.11, 95% CI 1.14 to 25.08, P=0.66) while the mean arterial blood pressure (MD -1.38, 95% CI -5.16 to 2.41, P=0.48) and left ventricular end diastolic pressure (MD -2.45, 95% CI -4.46 to -0.43, P=0.02) were lower as compared to the those on placebo. There were insignificant changes in cardiac output (SMD 0.28, 95% CI -0.24 to 0.80, P=0.29) and left ventricular end systolic pressure (MD 1.48, 95% CI -3.86 to 6.82, P=0.59). CONCLUSIONS The existing data provides evidence to suggest that Ghrelin may lower the risk of mortality and improve cardiovascular outcomes. However; the quality of evidence as assessed by GRADEpro is low to very low. Clinical judgments to administer Ghrelin to patients with HF must be made on better designed animal studies.
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Affiliation(s)
- Mahalaqua Nazli Khatib
- Department of Physiology, Datta Meghe Institute of Medical Sciences, Wardha, Maharashtra State, India
| | - Anuraj Shankar
- Department of Nutrition, Harvard School of Public Health, Harvard University, Cambridge, Massachusetts, United States of America
| | | | - Kingsley Agho
- Department Biostatistics, University of Western Sydney, Sydney, Australia
| | - Padam Simkhada
- Centre for Public Health, Liverpool John Moores University, Liverpool, United Kingdom
| | - Shilpa Gaidhane
- Department of Medicine, Datta Meghe Institute of Medical Sciences, Wardha, Maharashtra State, India
| | - Deepak Saxena
- Indian Institute of Public Health-Gandhinagar, Public Health Foundation of India, New Delhi, India
| | - Unnikrishnan B
- Department of Community Medicine, Manipal University, Manipal, India
| | - Dilip Gode
- Datta Meghe Institute of Medical Sciences, Wardha, Maharashtra State, India
| | - Abhay Gaidhane
- Department of Community Medicine, Datta Meghe Institute of Medical Sciences, Wardha, Maharashtra State, India
| | - Syed Quazi Zahiruddin
- Department of Community Medicine, Datta Meghe Institute of Medical Sciences, Wardha, Maharashtra State, India
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Kaiya H, Konno N, Kangawa K, Uchiyama M, Miyazato M. Identification, tissue distribution and functional characterization of the ghrelin receptor in West African lungfish, Protopterus annectens. Gen Comp Endocrinol 2014; 209:106-17. [PMID: 25093625 DOI: 10.1016/j.ygcen.2014.07.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 07/16/2014] [Accepted: 07/26/2014] [Indexed: 12/29/2022]
Abstract
We identified two ghrelin receptor isoforms, the ghrelin receptor type-1a (GHS-R1a) and its alternative splice form (GHS-R1b) for West African lungfish, Protopterus annectens. Lungfish GHS-R1a and 1b comprised 361 and 281 amino acids, respectively. Lungfish GHS-R1a showed the highest identity to coelacanth GHS-R1a (80.4%). The highest expression of GHS-R1a mRNAs was seen in the brain, liver, ovary, heart, intestine, and gills. GHS-R1b mRNAs were also detected in the same tissues with GHS-R1a, but their expression level was 1/20 that of GHS-R1a. In human embryonic kidney 293 cells transiently expressing lungfish GHS-R1a, rat and bullfrog ghrelin, and two GHS-R1a agonists, GHRP-6 and hexarelin, increased intracellular Ca(2+) concentrations. The intensity of the Ca(2+) increases induced by GHS-R1a agonists was twice when compared to that induced by ghrelin, although the median effective doses (ED50) were similar, suggesting a long-lasting effect of GHS-R1a agonists with similar affinity. We also examined changes in the GHS-R gene expression during an eight-week estivation. Body weight was slightly lowered, but plasma sodium and glucose concentrations decreased; plasma urea concentration increased significantly 4weeks after the start of estivation. Overall, expression of GHS-R1a mRNA decreased, but changes in GHS-R1b mRNA expression were inconsistent with those of GHS-R1a during estivation, suggesting an involvement of GHS-R in energy homeostasis, as seen in mammals. Our results suggest that the ghrelin-GHS-R1a system is present in this lungfish although ghrelin has not yet been found. The structure of GHS-R1a is closer to that of tetrapods than Actinopterygian fish, indicating a process of evolution that follows the Crossopterygii such as coelacanth.
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Affiliation(s)
- Hiroyuki Kaiya
- Department of Biochemistry, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
| | - Minoru Uchiyama
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
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The cardiovascular action of hexarelin. JOURNAL OF GERIATRIC CARDIOLOGY : JGC 2014; 11:253-8. [PMID: 25278975 PMCID: PMC4178518 DOI: 10.11909/j.issn.1671-5411.2014.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 05/25/2014] [Accepted: 07/10/2014] [Indexed: 11/21/2022]
Abstract
Hexarelin, a synthetic growth hormone-releasing peptide, can bind to and activate the growth hormone secretagogue receptor (GHSR) in the brain similar to its natural analog ghrelin. However, the peripheral distribution of GHSR in the heart and blood vessels suggests that hexarelin might have direct cardiovascular actions beyond growth hormone release and neuroendocrine effects. Furthermore, the non-GHSR CD36 had been demonstrated to be a specific cardiac receptor for hexarelin and to mediate its cardioprotective effects. When compared with ghrelin, hexarelin is chemically more stable and functionally more potent. Therefore, it may be a promising therapeutic agent for some cardiovascular conditions. In this concise review, we discuss the current evidence for the cardiovascular action of hexarelin.
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Yuan MJ, Huang H, Quan L, Tang YH, Wang X, Jiang H, Huang CX. Expression of ghrelin and its receptor in rats after coronary artery ligation. ACTA ACUST UNITED AC 2014; 192-193:1-5. [PMID: 25058156 DOI: 10.1016/j.regpep.2014.07.001] [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: 05/01/2014] [Revised: 06/18/2014] [Accepted: 07/14/2014] [Indexed: 11/26/2022]
Abstract
Ghrelin is a novel growth hormone-releasing peptide, which has been shown to exert beneficial effects on cardiac function and ventricular remodeling. The present study aimed to investigate the expression of ghrelin and the growth hormone (GH) secretagogue receptor 1a (GHSR-1a), and the association with cardiac remodeling in rats with myocardial infarction (MI). Twenty-four hours after ligation of the anterior descending artery (LAD), adult male Sprague-Dawley rats were randomized to 3 d, 7 d and 28 d group. Sham animals underwent thoracotomy and pericardiotomy, but not LAD ligation. Expression of both ghrelin and GHSR-1a was assessed by means of immunohistochemistry and real-time PCR. Plasma ghrelin levels were measured by ELISA kit. In addition, cardiac remodeling was assessed by echocardiographic and hemodynamic measurements. Plasma and cardiac expression of ghrelin decreased on days 3, 7 and 28 compared with the sham group (P<0.05). In contrast the GHSR-1a mRNA levels increased during the same days (P<0.05). Decreased positive immunoreaction for ghrelin and increased positive GHSR-1a were also observed in the infarcted heart. Interestingly, plasma ghrelin correlated negatively with left ventricular end-diastolic pressure (r=-0.59, P=0.002) and left ventricular end-diastolic dimension (r=-0.73, P<0.01). The ghrelin system may play an important role regulating cardiac remodeling after MI and present as a potential significant target for pharmacological modulation and treating cardiac remodeling.
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Affiliation(s)
- Ming-Jie Yuan
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China
| | - He Huang
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China
| | - Li Quan
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China
| | - Yan-Hong Tang
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China
| | - Xi Wang
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China
| | - Hong Jiang
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China
| | - Cong-Xin Huang
- Dept of Cardiology, Wuhan Univ, Renmin Hospital, Wuhan 430060, Hubei Province, PR China.
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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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Yuan MJ, Huang H, Huang CX. Potential new role of the GHSR-1a-mediated signaling pathway in cardiac remodeling after myocardial infarction (Review). Oncol Lett 2014; 8:969-971. [PMID: 25120643 PMCID: PMC4114710 DOI: 10.3892/ol.2014.2245] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 05/15/2014] [Indexed: 11/17/2022] Open
Abstract
The gastrointestinal hormone ghrelin has important cardiovascular protective effects, however, its specific mechanisms are not yet completely understood. Recent studies have shown that the ghrelin receptor, growth hormone secretagogue receptor type 1a (GHSR-1a), regulates cell proliferation, apoptosis and inflammation-related signaling pathways. In human aortic endothelial cells, ghrelin activates NO production through AMP-activated protein kinase (AMPK) and Akt activation, and these effects can be blocked by knockdown of GHSR-1a. Obese mice have been found to exhibit an increased GHSR-1a content and expression in the heart, associated with an increase in phosphatidylinositol 3-kinase (PI3K) content and an increase AKT content and phosphorylation. Furthermore, GHSR-1a expression was observed to be increased in heart failure after myocardial infarction (MI) in rats. Given such complexity in GHSR-1a signaling and crosstalk with the AMPK and PI3K/Akt signaling pathways, both of which are well-known factors involved in cardiac remodeling after MI, we speculate that GHSR-1a signaling may play a regulatory role in cardiac protection and hope to identify new drugs targets. However, to date, no direct association between GHSR-1a and cardiac remodeling has been found. Therefore, further studies are required.
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Affiliation(s)
- Ming-Jie Yuan
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - He Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Cong-Xin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
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Mao Y, Tokudome T, Kishimoto I, Otani K, Miyazato M, Kangawa K. One dose of oral hexarelin protects chronic cardiac function after myocardial infarction. Peptides 2014; 56:156-62. [PMID: 24747279 DOI: 10.1016/j.peptides.2014.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 04/04/2014] [Accepted: 04/04/2014] [Indexed: 10/25/2022]
Abstract
Both hexarelin and its natural analog ghrelin exert comparable cardioprotective activities. A single dose of ghrelin administered at the very acute phase after experimental myocardial infarction positively affects cardiac function in chronic heart failure. Therefore, this study aimed to determine whether a single dose of oral hexarelin has the same effect in the chronic disease phase. Myocardial infarction or sham operation was generated by left coronary artery ligation in male C57BL/6J mice, which subsequently received one dose of hexarelin or vehicle treatment by oral gavage 30 min after operation. Although the mortality within 14 days after myocardial infarction did not differ between the groups, hexarelin treatment protected cardiac function in the chronic phase as evidenced by higher ejection fraction and fractional shortening, as well as lower lung weight/body weight and lung weight/tibial length ratios, compared with vehicle treatment. Hexarelin treatment concurrently lowered plasma epinephrine and dopamine levels, and shifted the balance of autonomic nervous activity toward parasympathetic nervous activity as evidenced by a smaller low/high-frequency power ratio and larger normalized high-frequency power on heart rate variability analysis. The results first demonstrate that one dose of oral hexarelin treatment potentially protects chronic cardiac function after acute myocardial infarction, and implicate that activating growth hormone secretagogue receptor 1a might be beneficial for cardioprotection, although other mechanism may also be involved.
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Affiliation(s)
- Yuanjie Mao
- Department of Biochemistry, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Takeshi Tokudome
- Department of Biochemistry, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Ichiro Kishimoto
- Department of Biochemistry, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan.
| | - Kentaro Otani
- Department of Regenerative Medicine and Tissue Engineering, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
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Zhu J, Zheng C, Chen J, Luo J, Su B, Huang Y, Su W, Li Z, Cui T. Ghrelin protects human umbilical vein endothelial cells against high glucose-induced apoptosis via mTOR/P70S6K signaling pathway. Peptides 2014; 52:23-8. [PMID: 24287118 DOI: 10.1016/j.peptides.2013.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 11/17/2013] [Accepted: 11/18/2013] [Indexed: 12/31/2022]
Abstract
Ghrelin exhibits its biological effect through binding to the growth hormone secretagogue 1a receptor (GHS-R1a). Recently, it has been reported that ghrelin has an anti-apoptotic effect in several cell types. However, the molecule mechanisms underlying the anti-apoptotic effect of ghrelin remain poorly understood. In this study, we investigated the intracellular mechanisms responsible for anti-apoptotic effect of ghrelin on human umbilical vein endothelial cells (HUVEC). Treatment of HUVEC with ghrelin inhibited high glucose-induced cell apoptosis. Ghrelin stimulated the rapid phosphorylation of mammalian target of rapamycin (mTOR), P70S6K and S6. The GHS-R1a-specific antagonist [D-Lys3]-GHRP-6 abolished the anti-apoptotic effect and inhibited the activation of mTOR, P70S6K, S6 induced by ghrelin. Pretreatment of cells with specific inhibitor of mTOR blocked the anti-apoptotic effect of ghrelin. In addition, ghrelin protected HUVECs against high glucose induced apoptosis by increasing Bcl-2/Bax ratio. Taken together, our results demonstrate that ghrelin produces a protective effect on HUVECs through activating GHS-R1a and mTOR/P70S6K signaling pathway mediates the effect of ghrelin. These observations suggest that ghrelin may act as a survival factor in preventing HUVECs apoptosis caused by high glucose.
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Affiliation(s)
- Jianhua Zhu
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Chenghong Zheng
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China; Department of Endocrinology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Jie Chen
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Jing Luo
- Department of Biochemistry & Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Bintao Su
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Yan Huang
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Wen Su
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Zixi Li
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China
| | - Tianpen Cui
- Laboratory of Clinical Immunology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, PR China.
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Rodríguez A. Novel molecular aspects of ghrelin and leptin in the control of adipobiology and the cardiovascular system. Obes Facts 2014; 7:82-95. [PMID: 24685565 PMCID: PMC5644879 DOI: 10.1159/000360837] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/15/2013] [Indexed: 01/27/2023] Open
Abstract
Ghrelin and leptin show opposite effects on energy balance. Ghrelin constitutes a gut hormone that is secreted to the bloodstream in two major forms, acylated and desacyl ghrelin. The isoforms of ghrelin not only promote adiposity by the activation of hypothalamic orexigenic neurons but also directly stimulate the expression of several fat storage-related proteins in adipocytes, including ACC, FAS, LPL and perilipin, thereby stimulating intracytoplasmic lipid accumulation. Moreover, both acylated and desacyl ghrelin reduce TNF-α-induced apoptosis and autophagy in adipocytes, suggesting an anti-inflammatory role of ghrelin in human adipose tissue. On the other hand, leptin is an adipokine with lipolytic effects. In this sense, leptin modulates via PI3K/Akt/mTOR the expression of aquaglyceroporins such as AQP3 and AQP7 that facilitate glycerol efflux from adipocytes in response to the lipolytic stimuli via its translocation from the cytosolic fraction (AQP3) or lipid droplets (AQP7) to the plasma membrane. Ghrelin and leptin also participate in the homeostasis of the cardiovascular system. Ghrelin operates as a cardioprotective factor with increased circulating acylated ghrelin concentrations in patients with left ventricular hypertrophy (LVH) causally related to LV remodeling during the progression to LVH. Additionally, leptin induces vasodilation by inducible NO synthase expression (iNOS) in the vascular wall. In this sense, leptin inhibits the angiotensin II-induced Ca(2+) increase, contraction and proliferation of VSMC through NO-dependent mechanisms. Together, dysregulation of circulating ghrelin isoforms and leptin resistance associated to obesity, type 2 diabetes, or the metabolic syndrome contribute to cardiometabolic derangements observed in these pathologies.
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Affiliation(s)
- Amaia Rodríguez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain
- *Amaia Rodrèguez, PhD, Metabolic Research Laboratory, Clínica Universidad de Navarra, Irunlarrea 1, 31008 Pamplona (Spain),
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Mao Y, Tokudome T, Kishimoto I, Otani K, Hosoda H, Nagai C, Minamino N, Miyazato M, Kangawa K. Hexarelin treatment in male ghrelin knockout mice after myocardial infarction. Endocrinology 2013; 154:3847-54. [PMID: 23861368 DOI: 10.1210/en.2013-1291] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Both ghrelin and the synthetic analog hexarelin are reported to possess cardioprotective actions that are mainly exerted through different receptors. However, their effects on acute myocardial infarction have not been compared in vivo. This study aimed to clarify whether hexarelin treatment can compensate for ghrelin deficiency in ghrelin-knockout mice and to compare the effects of hexarelin (400 nmol/kg/d, sc) and equimolar ghrelin treatment after myocardial infarction. Myocardial infarction was produced by left coronary artery ligation in male ghrelin-knockout mice, which then received ghrelin, hexarelin, or vehicle treatment for 2 weeks. The mortality within 2 weeks was significantly lower in the hexarelin group (6.7%) and ghrelin group (14.3%) than in the vehicle group (50%) (P < .05). A comparison of cardiac function 2 weeks after infarction showed that in the ghrelin and hexarelin treatment groups, cardiac output was greater, whereas systolic function, represented by ejection fraction, and diastolic function, represented by dP/dt min (peak rate of pressure decline), were significantly superior compared with the vehicle group (P < .05). Hexarelin treatment was more effective than ghrelin treatment, as indicated by the ejection fraction, dP/dt max (peak rate of pressure rise), and dP/dt min. Telemetry recording and heart rate variability analysis demonstrated that sympathetic nervous activity was clearly suppressed in the hexarelin and ghrelin groups relative to the vehicle group. Our data demonstrated that hexarelin treatment can result in better heart function than ghrelin treatment 2 weeks after myocardial infarction in ghrelin-knockout mice, although both hormones have similar effects on heart rate variability and mortality.
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Affiliation(s)
- Yuanjie Mao
- Department of Biochemistry, National Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan.
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Ma Y, Zhang L, Launikonis BS, Chen C. Growth hormone secretagogues preserve the electrophysiological properties of mouse cardiomyocytes isolated from in vitro ischemia/reperfusion heart. Endocrinology 2012; 153:5480-90. [PMID: 22948211 DOI: 10.1210/en.2012-1404] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ischemic heart diseases often induce cardiac arrhythmia with irregular cardiac action potential (AP). This study aims to demonstrate that GH secretagogues (GHS) ghrelin and its synthetic analog hexarelin can preserve the electrophysiological properties of cardiomyocytes experiencing ischemia/reperfusion (I/R). Isolated hearts from adult male mice underwent 20 min global ischemia followed by 30 min reperfusion using a Langendorff apparatus. Ghrelin (10 nM) or hexarelin (1 nM) was administered in the perfusion solution either 10 min before or after ischemia, termed pre- or posttreatments. Cardiomyocytes isolated from these hearts were used for whole-cell patch clamping to measure AP, voltage-gated L-type calcium current (I(CaL)), transient outward potassium current (I(to)), and sodium current (I(Na)). AP amplitude and duration were significantly decreased by I/R, but GHS treatments maintained their normality. GHS treatments prevented the decrease in I(CaL) and I(Na) after I/R, thereby maintaining AP amplitude. Although the significant increase in I(to) after I/R partially explained the shortened AP duration, the normalization of it by GHS treatments might contribute to the preservation of AP duration. Phosphorylated p38 and c-Jun NH(2)-terminal kinase and the downstream active caspase-9 in the cellular apoptosis pathway were significantly increased after I/R but not when GHS treatments were included, whereas phosphorylation of ERK1/2 associated with cell survival showed increase after I/R and a further increase after GHS treatments by binding to its receptor GHS receptor type 1a. These results suggest GHS can not only preserve the electrophysiological properties of cardiomyocytes after I/R but also inhibit cardiomyocyte apoptosis and promote cell survival by modification of MAPK pathways through activating GHS receptor type 1a.
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Affiliation(s)
- Yi Ma
- School of Biomedical Sciences, University of Queensland, St. Lucia, Australia
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