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Gauvin J, Huynh DN, Dubuc I, Lê C, Tugores R, Flamand N, Flamand L, Lubell WD, Ong H, Marleau S. Pharmacological targeting of the hyper-inflammatory response to SARS-CoV-2-infected K18-hACE2 mice using a cluster of differentiation 36 receptor modulator. Front Pharmacol 2024; 15:1303342. [PMID: 38384295 PMCID: PMC10879382 DOI: 10.3389/fphar.2024.1303342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/25/2024] [Indexed: 02/23/2024] Open
Abstract
The scientific and medical community faced an unprecedented global health hazard that led to nearly 7 million deaths attributable to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In spite of the development of efficient vaccines against SARS-CoV-2, many people remain at risk of developing severe symptoms as the virus continues to spread without beneficial patient therapy. The hyper-inflammatory response to SARS-CoV-2 infection progressing to acute respiratory distress syndrome remains an unmet medical need for improving patient care. The viral infection stimulates alveolar macrophages to adopt an inflammatory phenotype regulated, at least in part, by the cluster of differentiation 36 receptor (CD36) to produce unrestrained inflammatory cytokine secretions. We suggest herein that the modulation of the macrophage response using the synthetic CD36 ligand hexarelin offers potential as therapy for halting respiratory failure in SARS-CoV-2-infected patients.
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Affiliation(s)
- Jade Gauvin
- Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada
| | - David N. Huynh
- Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada
| | - Isabelle Dubuc
- Department of Microbiology, Infectious Diseases and and Immunology, Université Laval, Québec, QC, Canada
| | - Catherine Lê
- Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada
| | - Rafaela Tugores
- Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada
| | - Nicolas Flamand
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Département de Médecine, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Louis Flamand
- Department of Microbiology, Infectious Diseases and and Immunology, Université Laval, Québec, QC, Canada
| | - William D. Lubell
- Department of Chemistry, Université de Montréal, Montréal, QC, Canada
| | - Huy Ong
- Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada
| | - Sylvie Marleau
- Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada
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Guan C, Li C, Shen X, Yang C, Liu Z, Zhang N, Xu L, Zhao L, Zhou B, Man X, Luo C, Luan H, Che L, Wang Y, Xu Y. Hexarelin alleviates apoptosis on ischemic acute kidney injury via MDM2/p53 pathway. Eur J Med Res 2023; 28:344. [PMID: 37710348 PMCID: PMC10500723 DOI: 10.1186/s40001-023-01318-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/27/2023] [Indexed: 09/16/2023] Open
Abstract
INTRODUCTION Hexarelin exhibits significant protection against organ injury in models of ischemia/reperfusion (I/R)-induced injury (IRI). Nevertheless, the impact of Hexarelin on acute kidney injury (AKI) and its underlying mechanism remains unclear. In this study, we investigated the therapeutic potential of Hexarelin in I/R-induced AKI and elucidated its molecular mechanisms. METHODS We assessed the protective effects of Hexarelin through both in vivo and in vitro experiments. In the I/R-induced AKI model, rats were pretreated with Hexarelin at 100 μg/kg/d for 7 days before being sacrificed 24 h post-IRI. Subsequently, kidney function, histology, and apoptosis were assessed. In vitro, hypoxia/reoxygenation (H/R)-induced HK-2 cell model was used to investigate the impact of Hexarelin on apoptosis in HK-2 cells. Then, we employed molecular docking using a pharmmapper server and autodock software to identify potential target proteins of Hexarelin. RESULTS In this study, rats subjected to I/R developed severe kidney injury characterized by tubular necrosis, tubular dilatation, increased serum creatinine levels, and cell apoptosis. However, pretreatment with Hexarelin exhibited a protective effect by mitigating post-ischemic kidney pathological changes, improving renal function, and inhibiting apoptosis. This was achieved through the downregulation of conventional apoptosis-related genes, such as Caspase-3, Bax and Bad, and the upregulation of the anti-apoptotic protein Bcl-2. Consistent with the in vivo results, Hexarelin also reduced cell apoptosis in post-H/R HK-2 cells. Furthermore, our analysis using GSEA confirmed the essential role of the apoptosis pathway in I/R-induced AKI. Molecular docking revealed a strong binding affinity between Hexarelin and MDM2, suggesting the potential mechanism of Hexarelin's anti-apoptosis effect at least partially through its interaction with MDM2, a well-known negative regulator of apoptosis-related protein that of p53. To validate these findings, we evaluated the relative expression of MDM2 and p53 in I/R-induced AKI with or without Hexarelin pre-administration and observed a significant suppression of MDM2 and p53 by Hexarelin in both in vivo and in vitro experiments. CONCLUSION Collectively, Hexarelin was identified as a promising medication in protecting apoptosis against I/R-induced AKI.
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Affiliation(s)
- Chen Guan
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Chenyu Li
- Medizinische Klinik Und Poliklinik IV, Klinikum Der Universität, LMU München, Munich, Germany
| | - Xuefei Shen
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Chengyu Yang
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Zengying Liu
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Ningxin Zhang
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Lingyu Xu
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Long Zhao
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Bin Zhou
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Xiaofei Man
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Congjuan Luo
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Hong Luan
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Lin Che
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Yanfei Wang
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China
| | - Yan Xu
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, China.
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Waddingham MT, Tsuchimochi H, Sonobe T, Asano R, Jin H, Ow CPC, Schwenke DO, Katare R, Aoyama K, Umetani K, Hoshino M, Uesugi K, Shirai M, Ogo T, Pearson JT. Using Synchrotron Radiation Imaging Techniques to Elucidate the Actions of Hexarelin in the Heart of Small Animal Models. Front Physiol 2022; 12:766818. [PMID: 35126171 PMCID: PMC8814524 DOI: 10.3389/fphys.2021.766818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
The majority of the conventional techniques that are utilized for investigating the pathogenesis of cardiovascular disease in preclinical animal models do not permit microlevel assessment of in situ cardiomyocyte and microvascular functions. Therefore, it has been difficult to establish whether cardiac dysfunction in complex multiorgan disease states, such as heart failure with preserved ejection fraction and pulmonary hypertension, have their origins in microvascular dysfunction or rather in the cardiomyocyte. Herein, we describe our approach of utilizing synchrotron radiation microangiography to, first, ascertain whether the growth hormone secretagogue (GHS) hexarelin is a vasodilator in the coronary circulation of normal and anesthetized Sprague-Dawley rats, and next investigate if hexarelin is able to prevent the pathogenesis of right ventricle (RV) dysfunction in pulmonary hypertension in the sugen chronic hypoxia model rat. We show that acute hexarelin administration evokes coronary microvascular dilation through GHS-receptor 1a and nitric oxide, and through endothelium-derived hyperpolarization. Previous work indicated that chronic exogenous administration of ghrelin largely prevented the pathogenesis of pulmonary hypertension in chronic hypoxia and in monocrotaline models. Unexpectedly, chronic hexarelin administration prior to sugen chronic hypoxia did not prevent RV hypertrophy or RV cardiomyocyte relaxation impairment. Small-angle X-ray scattering revealed that super relaxed myosin filaments contributed to diastolic dysfunction, and that length-dependent activation might contribute to sustained contractility of the RV. Thus, synchrotron-based imaging approaches can reveal novel insights into cardiac and coronary functions in vivo.
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Affiliation(s)
- Mark T. Waddingham
- Department of Advanced Medical Research for Pulmonary Hypertension, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Takashi Sonobe
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Ryotaro Asano
- Department of Advanced Medical Research for Pulmonary Hypertension, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Huiling Jin
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Connie P. C. Ow
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Daryl O. Schwenke
- Department of Physiology, School of Biomedical Sciences, Heart Otago, University of Otago, Dunedin, New Zealand
| | - Rajesh Katare
- Department of Physiology, School of Biomedical Sciences, Heart Otago, University of Otago, Dunedin, New Zealand
| | - Kohki Aoyama
- Japan Synchrotron Radiation Research Institute, Harima, Japan
| | - Keiji Umetani
- Japan Synchrotron Radiation Research Institute, Harima, Japan
| | - Masato Hoshino
- Japan Synchrotron Radiation Research Institute, Harima, Japan
| | - Kentaro Uesugi
- Japan Synchrotron Radiation Research Institute, Harima, Japan
| | - Mikiyasu Shirai
- Department of Advanced Medical Research for Pulmonary Hypertension, National Cerebral and Cardiovascular Center, Suita, Japan
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Takeshi Ogo
- Department of Advanced Medical Research for Pulmonary Hypertension, National Cerebral and Cardiovascular Center, Suita, Japan
| | - James T. Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
- *Correspondence: James T. Pearson
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Hexarelin modulates lung mechanics, inflammation, and fibrosis in acute lung injury. Drug Target Insights 2021; 15:26-33. [PMID: 34871336 PMCID: PMC8638068 DOI: 10.33393/dti.2021.2347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/20/2021] [Indexed: 12/27/2022] Open
Abstract
Introduction: Acute respiratory distress syndrome (ARDS) is an acute form of diffuse lung injury characterized by (i) an intense inflammatory response, (ii) increased pulmonary vascular permeability, and (iii) the loss of respiratory pulmonary tissue. In this article we explore the therapeutic potential of hexarelin, a synthetic hexapeptide growth hormone secretagogue (GHS), in an experimental model of ARDS. Hexarelin has anti-inflammatory properties and demonstrates cardiovascular-protective activities including the inhibition of cardiomyocyte apoptosis and cardiac fibrosis, both of which may involve the angiotensin-converting enzyme (ACE) system. Methods: In our experimental model, ARDS was induced by the instillation of 100 mM HCl into the right bronchus; these mice were treated with hexarelin (320 μg/kg, ip) before (Pre) or after (Post) HCl challenge, or with vehicle. Respiratory system compliance, blood gas analysis, and differential cell counts in a selective bronchoalveolar lavage (BAL) were determined 6 or 24 hours after HCl instillation. In an extended study, mice were observed for a subsequent 14 days in order to assess lung fibrosis. Results: Hexarelin induced a significant improvement in lung compliance and a reduction of the number of total immune cells in BAL 24 hours after HCl instillation, accompanied with a lower recruitment of neutrophils compared with the vehicle group. At day 14, hexarelin-treated mice presented with less pulmonary collagen deposition compared with vehicle-treated controls. Conclusions: Our data suggest that hexarelin can inhibit the early phase of the inflammatory response in a murine model of HCl-induced ARDS, thereby blunting lung remodeling processes and fibrotic development.
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Hexarelin Modulation of MAPK and PI3K/Akt Pathways in Neuro-2A Cells Inhibits Hydrogen Peroxide-Induced Apoptotic Toxicity. Pharmaceuticals (Basel) 2021; 14:ph14050444. [PMID: 34066741 PMCID: PMC8150489 DOI: 10.3390/ph14050444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 11/17/2022] Open
Abstract
Hexarelin, a synthetic hexapeptide, exerts cyto-protective effects at the mitochondrial level in cardiac and skeletal muscles, both in vitro and in vivo, may also have important neuroprotective bioactivities. This study examined the inhibitory effects of hexarelin on hydrogen peroxide (H2O2)-induced apoptosis in Neuro-2A cells. Neuro-2A cells were treated for 24 h with various concentrations of H2O2 or with the combination of H2O2 and hexarelin following which cell viability and nitrite (NO2−) release were measured. Cell morphology was also documented throughout and changes arising were quantified using Image J skeleton and fractal analysis procedures. Apoptotic responses were evaluated by Real-Time PCR (caspase-3, caspase-7, Bax, and Bcl-2 mRNA levels) and Western Blot (cleaved caspase-3, cleaved caspase-7, MAPK, and Akt). Our results indicate that hexarelin effectively antagonized H2O2-induced damage to Neuro-2A cells thereby (i) improving cell viability, (ii) reducing NO2− release and (iii) restoring normal morphologies. Hexarelin treatment also reduced mRNA levels of caspase-3 and its activation, and modulated mRNA levels of the BCL-2 family. Moreover, hexarelin inhibited MAPKs phosphorylation and increased p-Akt protein expression. In conclusion, our results demonstrate neuroprotective and anti-apoptotic effects of hexarelin, suggesting that new analogues could be developed for their neuroprotective effects.
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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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Agbo E, Liu D, Li M, Saahene RO, Chen L, Zhao L, Wang Y, Tian G. Modulation of PTEN by hexarelin attenuates coronary artery ligation-induced heart failure in rats. Turk J Med Sci 2019; 49:945-958. [PMID: 31091855 PMCID: PMC7018219 DOI: 10.3906/sag-1812-49] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background/aim Hexarelin is a synthetic growth hormone-releasing peptide that exerts cardioprotective effects. However, its cardioprotective effect against heart failure (HF) is yet to be explained. This study investigated the therapeutic role of hexarelin and the mechanisms underlying its cardioprotective effects against coronary artery ligation (CAL)-induced HF in rats. Materials and methods Rats with four weeks of permanent CAL, induced myocardial infarction, and HF were randomly separated into four groups: the control group (Ctrl), sham group (Sham), hexarelin treatment group (HF + Hx), and heart failure group (HF). The rats were treated with subcutaneous injection of hexarelin (100 µg/kg) in the treatment group or saline in the other groups twice a day for 30 days. Left ventricular (LV) function, oxidative stress, apoptosis, molecular analyses, and cardiac structural and pathological changes in rats were assessed. Results The treatment of HF rats with hexarelin significantly induced the upregulation of phosphatase and tensin homologue (PTEN) expression and inhibited the phosphorylation of protein kinase B (Akt) and mammalian target of rapamycin (mTOR) to significantly improve LV function, ameliorate myocardial remodeling, and reduce oxidative stress. Conclusion These findings indicate that hexarelin attenuates CAL-induced HF in rats by ameliorating myocardial remodeling, LV dysfunction, and oxidative stress via the upmodulation of PTEN signaling and downregulation of the Akt/mTOR signaling pathway.
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Affiliation(s)
- Elvis Agbo
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Donhai Liu
- College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Meixiu Li
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Roland Osei Saahene
- Department of Immunology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Liqiang Chen
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Lunpeng Zhao
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Yiquan Wang
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Guozhong Tian
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
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The CD36-PPARγ Pathway in Metabolic Disorders. Int J Mol Sci 2018; 19:ijms19051529. [PMID: 29883404 PMCID: PMC5983591 DOI: 10.3390/ijms19051529] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/08/2018] [Accepted: 05/16/2018] [Indexed: 12/21/2022] Open
Abstract
Uncovering the biological role of nuclear receptor peroxisome proliferator-activated receptors (PPARs) has greatly advanced our knowledge of the transcriptional control of glucose and energy metabolism. As such, pharmacological activation of PPARγ has emerged as an efficient approach for treating metabolic disorders with the current use of thiazolidinediones to improve insulin resistance in diabetic patients. The recent identification of growth hormone releasing peptides (GHRP) as potent inducers of PPARγ through activation of the scavenger receptor CD36 has defined a novel alternative to regulate essential aspects of lipid and energy metabolism. Recent advances on the emerging role of CD36 and GHRP hexarelin in regulating PPARγ downstream actions with benefits on atherosclerosis, hepatic cholesterol biosynthesis and fat mitochondrial biogenesis are summarized here. The response of PPARγ coactivator PGC-1 is also discussed in these effects. The identification of the GHRP-CD36-PPARγ pathway in controlling various tissue metabolic functions provides an interesting option for metabolic disorders.
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McDonald H, Peart J, Kurniawan N, Galloway G, Royce S, Samuel CS, Chen C. Hexarelin treatment preserves myocardial function and reduces cardiac fibrosis in a mouse model of acute myocardial infarction. Physiol Rep 2018; 6:e13699. [PMID: 29756411 PMCID: PMC5949285 DOI: 10.14814/phy2.13699] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 04/14/2018] [Indexed: 12/11/2022] Open
Abstract
Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Growth hormone secretagogues (GHS) have been shown to improve cardiac function in models of IHD. This study determined whether hexarelin (HEX), a synthetic GHS, preserves cardiac function and morphology in a mouse model of myocardial infarction (MI). MI was induced by ligation of the left descending coronary artery in C57BL/6J mice followed by vehicle (VEH; n = 10) or HEX (0.3 mg/kg/day; n = 11) administration for 21 days. MI-injured and sham mice (treated with VEH; n = 6 or HEX; n = 5) underwent magnetic resonance imaging for measurement of left ventricular (LV) function, mass and infarct size at 24 h and 14 days post-MI. MI-HEX mice displayed a significant improvement (P < 0.05) in LV function compared with MI-VEH mice after 14 days treatment. A significant decrease in LV mass, interstitial collagen and collagen concentration was demonstrated with chronic HEX treatment (for 21 days), accompanied by a decrease in TGF-β1 expression, myofibroblast differentiation and an increase in collagen-degrading MMP-13 expression levels. Furthermore, heart rate variability analysis demonstrated that HEX treatment shifted the balance of autonomic nervous activity toward a parasympathetic predominance and sympathetic downregulation. This was combined with a HEX-dependent decrease in troponin-I, IL-1β and TNF-α levels suggestive of amelioration of cardiomyocyte injury. These results demonstrate that GHS may preserve ventricular function, reduce inflammation and favorably remodel the process of fibrotic healing in a mouse model of MI and hold the potential for translational application to patients suffering from MI.
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Affiliation(s)
- Hayley McDonald
- School of Biomedical ScienceUniversity of QueenslandBrisbaneAustralia
| | - Jason Peart
- Menzies Health Institute of QueenslandGriffith UniversityGold CoastAustralia
| | - Nyoman Kurniawan
- Centre for Advanced ImagingUniversity of QueenslandBrisbaneAustralia
| | - Graham Galloway
- Centre for Advanced ImagingUniversity of QueenslandBrisbaneAustralia
| | - Simon Royce
- Cardiovascular Disease ProgramBiomedical Discovery Institute and Department of PharmacologyMonash UniversityVictoriaAustralia
- Central Clinical SchoolMonash UniversityVictoriaAustralia
| | - Chrishan S. Samuel
- Cardiovascular Disease ProgramBiomedical Discovery Institute and Department of PharmacologyMonash UniversityVictoriaAustralia
| | - Chen Chen
- School of Biomedical ScienceUniversity of QueenslandBrisbaneAustralia
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Mosa R, Huang L, Wu Y, Fung C, Mallawakankanamalage O, LeRoith D, Chen C. Hexarelin, a Growth Hormone Secretagogue, Improves Lipid Metabolic Aberrations in Nonobese Insulin-Resistant Male MKR Mice. Endocrinology 2017; 158:3174-3187. [PMID: 28977588 PMCID: PMC5659698 DOI: 10.1210/en.2017-00168] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 07/10/2017] [Indexed: 12/16/2022]
Abstract
Despite the occurrence of dyslipidemia and its contribution to the development of insulin resistance in obese subjects, a growing number of studies have described abnormal lipid profiles among leaner persons. For example, individuals with an abnormal paucity or distribution of fat (lipodystrophy) develop severe insulin resistance, dyslipidemia, and hepatic steatosis. Deranged adipocyte metabolism and differentiation contribute to ectopic fat deposition and consequent development of insulin resistance. Growth hormone (GH) therapy has been shown to correct body composition abnormalities in some lipodystrophy patients. However, little is known about the effects of GH-releasing peptides in this regard. Hexarelin, a GH secretagogue, has recently been shown to have beneficial effects on fat metabolism via the CD36 receptor. In this study, the effects of twice daily intraperitoneal injections of hexarelin (200 μg/kg body weight) were examined in nonobese insulin-resistant MKR mice and corresponding wild-type FVB mice for 12 days. Hexarelin treatment significantly improved glucose and insulin intolerance and decreased plasma and liver triglycerides in MKR mice. These beneficial metabolic effects could be due to the improved lipid metabolism and enhanced adipocyte differentiation of white adipose tissue with hexarelin treatment. Interestingly, although food intake of hexarelin-treated MKR mice was significantly increased, this did not change total body weight. Moreover, hexarelin treatment corrected the abnormal body composition of MKR mice, as demonstrated by a decrease in fat mass and an increase in lean mass. Our results suggest a possible application of hexarelin in treatment of lipid disorders associated with the metabolic syndrome.
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Affiliation(s)
- Rasha Mosa
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Lili Huang
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Yeda Wu
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Chungyan Fung
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Oshini Mallawakankanamalage
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Derek LeRoith
- Clinical Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Chen Chen
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Queensland 4072, Australia
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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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12
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Neale JPH, Pearson JT, Katare R, Schwenke DO. Ghrelin, MicroRNAs, and Critical Limb Ischemia: Hungering for a Novel Treatment Option. Front Endocrinol (Lausanne) 2017; 8:350. [PMID: 29326658 PMCID: PMC5733488 DOI: 10.3389/fendo.2017.00350] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/29/2017] [Indexed: 12/15/2022] Open
Abstract
Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery disease. It is characterized by chronic pain at rest, skin ulcerations, and gangrene tissue loss. CLI is a highly morbid condition, resulting in a severely diminished quality of life and a significant risk of mortality. The primary goal of therapy for CLI is to restore blood flow to the affected limb, which is only possible by surgery, but is inadvisable in up to 50% of patients. This subset of patients who are not candidates for revascularisation are referred to as "no-option" patients and are the focus of investigation for novel therapeutic strategies. Angiogenesis, arteriogenesis and vasculogenesis are the processes whereby new blood vessel networks form from the pre-existing vasculature and primordial cells, respectively. In therapeutic angiogenesis, exogenous stimulants are administered to promote angiogenesis and augment limb perfusion, offering a potential treatment option for "no option" patients. However, to date, very few clinical trials of therapeutic angiogenesis in patients with CLI have reported clinically significant results, and it remains a major challenge. Ghrelin, a 28-amino acid peptide, is emerging as a potential novel therapeutic for CLI. In pre-clinical models, exogenous ghrelin has been shown to induce therapeutic angiogenesis, promote muscle regeneration, and reduce oxidative stress via the modulation of microRNAs (miRs). miRs are endogenous, small, non-coding ribonucleic acids of ~20-22 nucleotides which regulate gene expression at the post-transcriptional level by either translational inhibition or by messenger ribonucleic acid cleavage. This review focuses on the mounting evidence for the use of ghrelin as a novel therapeutic for CLI, and highlights the miRs which orchestrate these physiological events.
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Affiliation(s)
- Joshua P. H. Neale
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| | - James T. Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
- Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Rajesh Katare
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
- *Correspondence: Rajesh Katare, ; Daryl O. Schwenke,
| | - Daryl O. Schwenke
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
- *Correspondence: Rajesh Katare, ; Daryl O. Schwenke,
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13
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Abstract
Ghrelin is a growth hormone-releasing polypeptide that was first isolated from the rat stomach in 1999. High expression of growth hormone secretagogue receptor, the ghrelin receptor, in the heart, kidney, and blood vessels provides evidence of ghrelin activity in blood pressure regulation. Circulating ghrelin concentrations are reported to be inversely correlated with blood pressure, and the acute and chronic effects of ghrelin in decreasing blood pressure have been reported in animals with normal blood pressure, healthy individuals, animals and patients with heart failure, and animals with hypertension. The mechanism by which ghrelin regulates blood pressure appears to be related to modulation of the autonomic nervous system, direct vasodilatory activities, and kidney diuresis. Thus, modulation of the signaling pathway through ghrelin may provide a novel concept for treating hypertension. In this review, we discuss the current evidence and potential mechanisms of ghrelin activity in blood pressure regulation.
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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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15
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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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