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Halmos G, Szabo Z, Juhasz E, Schally AV. Signaling mechanism of growth hormone-releasing hormone receptor. VITAMINS AND HORMONES 2023; 123:1-26. [PMID: 37717982 DOI: 10.1016/bs.vh.2023.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
The hypothalamic peptide growth hormone-releasing hormone (GHRH) stimulates the secretion of growth hormone (GH) from the pituitary through binding and activation of the pituitary type of GHRH receptor (GHRH-R), which belongs to the family of G protein-coupled receptors with seven potential membrane-spanning domains. Splice variants of GHRH-Rs (SV) in human tumors and other extra pituitary tissues were identified and their cDNA was sequenced. Among the SVs, splice variant 1 (SV1) possesses the greatest similarity to the full-length GHRH-R and remains functional by eliciting cAMP signaling and mitogenic activity upon GHRH stimulation. A large body of work have evaluated potential clinical applications of agonists and antagonists of GHRH in diverse fields, including endocrinology, oncology, cardiology, diabetes, obesity, metabolic dysfunctions, Alzheimer's disease, ophthalmology, wound healing and other applications. In this chapter, we briefly review the expression and potential function of GHRH-Rs and their SVs in various tissues and also elucidate and summarize the activation, molecular mechanism and signalization pathways of these receptors. Therapeutic applications of GHRH analogs are also discussed.
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Affiliation(s)
- Gabor Halmos
- Department of Biopharmacy, Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary; Veterans Affairs Medical Center, Endocrine, Polypeptide and Cancer Institute, Miami, FL, United States.
| | - Zsuzsanna Szabo
- Department of Biopharmacy, Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Eva Juhasz
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrew V Schally
- Veterans Affairs Medical Center, Endocrine, Polypeptide and Cancer Institute, Miami, FL, United States; Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL, United States; Department of Medicine, Divisions of Hematology-Oncology and Endocrinology, Miller School of Medicine, University of Miami, Miami, FL, United States; Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL, United States
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2
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Kanashiro-Takeuchi RM, Takeuchi LM, Dulce RA, Kazmierczak K, Balkan W, Cai R, Sha W, Schally AV, Hare JM. Efficacy of a growth hormone-releasing hormone agonist in a murine model of cardiometabolic heart failure with preserved ejection fraction. Am J Physiol Heart Circ Physiol 2023; 324:H739-H750. [PMID: 36897749 PMCID: PMC10151038 DOI: 10.1152/ajpheart.00601.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/27/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023]
Abstract
Heart failure (HF) with preserved ejection fraction (HFpEF) represents a major unmet medical need owing to its diverse pathophysiology and lack of effective therapies. Potent synthetic, agonists (MR-356 and MR-409) of growth hormone-releasing hormone (GHRH) improve the phenotype of models of HF with reduced ejection fraction (HFrEF) and in cardiorenal models of HFpEF. Endogenous GHRH exhibits a broad range of regulatory influences in the cardiovascular (CV) system and aging and plays a role in several cardiometabolic conditions including obesity and diabetes. Whether agonists of GHRH can improve the phenotype of cardiometabolic HFpEF remains untested and unknown. Here we tested the hypothesis that MR-356 can mitigate/reverse the cardiometabolic HFpEF phenotype. C57BL6N mice received a high-fat diet (HFD) plus the nitric oxide synthase inhibitor (l-NAME) for 9 wk. After 5 wk of HFD + l-NAME regimen, animals were randomized to receive daily injections of MR-356 or placebo during a 4-wk period. Control animals received no HFD + l-NAME or agonist treatment. Our results showed the unique potential of MR-356 to treat several HFpEF-like features including cardiac hypertrophy, fibrosis, capillary rarefaction, and pulmonary congestion. MR-356 improved cardiac performance by improving diastolic function, global longitudinal strain (GLS), and exercise capacity. Importantly, the increased expression of cardiac pro-brain natriuretic peptide (pro-BNP), inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor-A (VEGF-A) was restored to normal levels suggesting that MR-356 reduced myocardial stress associated with metabolic inflammation in HFpEF. Thus, agonists of GHRH may be an effective therapeutic strategy for the treatment of cardiometabolic HFpEF phenotype.NEW & NOTEWORTHY This randomized study used rigorous hemodynamic tools to test the efficacy of a synthetic GHRH agonist to improve cardiac performance in a cardiometabolic HFpEF. Daily injection of the GHRH agonist, MR-356, reduced the HFpEF-like effects as evidenced by improved diastolic dysfunction, reduced cardiac hypertrophy, fibrosis, and pulmonary congestion. Notably, end-diastolic pressure and end-diastolic pressure-volume relationship were reset to control levels. Moreover, treatment with MR-356 increased exercise capacity and reduced myocardial stress associated with metabolic inflammation in HFpEF.
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Affiliation(s)
- Rosemeire M Kanashiro-Takeuchi
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Lauro M Takeuchi
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Raul A Dulce
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Katarzyna Kazmierczak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Wayne Balkan
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Renzhi Cai
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, Florida, United States
| | - Wei Sha
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, Florida, United States
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Andrew V Schally
- Division of Oncology, Department of Medicine and Endocrinology, University of Miami Miller School of Medicine, Miami, Florida, United States
- Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, United States
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, Florida, United States
- Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, United States
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Joshua M Hare
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, United States
- Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, United States
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3
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Cen LP, Ng TK, Chu WK, Pang CP. Growth hormone-releasing hormone receptor signaling in experimental ocular inflammation and neuroprotection. Neural Regen Res 2022; 17:2643-2648. [PMID: 35662195 PMCID: PMC9165393 DOI: 10.4103/1673-5374.336135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/29/2021] [Accepted: 12/15/2021] [Indexed: 02/05/2023] Open
Abstract
Both inflammation and anti-inflammation are involved in the protection of retinal cells. Antagonists of the hypothalamic growth hormone-releasing hormone receptor (GHRHR) have been shown to possess potent anti-inflammatory properties in experimental disease models of various organs, some with systemic complications. Such effects are also found in ocular inflammatory and neurologic injury studies. In experimental models of mice and rats, both growth hormone-releasing hormone receptor agonists and antagonists may alleviate death of ocular neural cells under certain experimental conditions. This review explores the properties of growth hormone-releasing hormone receptor agonists and antagonists that lead to its protection against inflammatory responses induced by extrinsic agents or neurologic injures in ocular animal models.
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Affiliation(s)
- Ling-Ping Cen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong Province, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong Province, China
- Shantou University Medical College, Shantou, Guangdong Province, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Chi Pui Pang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong Province, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
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4
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Growth hormone-releasing hormone agonists ameliorate chronic kidney disease-induced heart failure with preserved ejection fraction. Proc Natl Acad Sci U S A 2021; 118:2019835118. [PMID: 33468654 DOI: 10.1073/pnas.2019835118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Therapies for heart failure with preserved ejection fraction (HFpEF) are lacking. Growth hormone-releasing hormone agonists (GHRH-As) have salutary effects in ischemic and nonischemic heart failure animal models. Accordingly, we hypothesized that GHRH-A treatment ameliorates chronic kidney disease (CKD)-induced HFpEF in a large-animal model. Female Yorkshire pigs (n = 16) underwent 5/6 nephrectomy via renal artery embolization and 12 wk later were randomized to receive daily subcutaneous injections of GHRH-A (MR-409; n = 8; 30 µg/kg) or placebo (n = 8) for 4 to 6 wk. Renal and cardiac structure and function were serially assessed postembolization. Animals with 5/6 nephrectomy exhibited CKD (elevated blood urea nitrogen [BUN] and creatinine) and faithfully recapitulated the hemodynamic features of HFpEF. HFpEF was demonstrated at 12 wk by maintenance of ejection fraction associated with increased left ventricular mass, relative wall thickness, end-diastolic pressure (EDP), end-diastolic pressure/end-diastolic volume (EDP/EDV) ratio, and tau, the time constant of isovolumic diastolic relaxation. After 4 to 6 wk of treatment, the GHRH-A group exhibited normalization of EDP (P = 0.03), reduced EDP/EDV ratio (P = 0.018), and a reduction in myocardial pro-brain natriuretic peptide protein abundance. GHRH-A increased cardiomyocyte [Ca2+] transient amplitude (P = 0.009). Improvement of the diastolic function was also evidenced by increased abundance of titin isoforms and their ratio (P = 0.0022). GHRH-A exerted a beneficial effect on diastolic function in a CKD large-animal model as demonstrated by improving hemodynamic, structural, and molecular characteristics of HFpEF. These findings have important therapeutic implications for the HFpEF syndrome.
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5
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Wang Z, Shao S, Cai Y. Effects of combination treatment with alprostadil and statins in patients with refractory heart failure. ALL LIFE 2020. [DOI: 10.1080/26895293.2020.1765884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Affiliation(s)
- Zishu Wang
- Department of Cardiology, the Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Shengchun Shao
- GCP Center, Hospital (T.C.M) Affiliated to Southwest Medical University, Luzhou, People’s Republic of China
| | - Yuyu Cai
- Department of Cardiology, the Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
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6
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Schally AV, Zhang X, Cai R, Hare JM, Granata R, Bartoli M. Actions and Potential Therapeutic Applications of Growth Hormone-Releasing Hormone Agonists. Endocrinology 2019; 160:1600-1612. [PMID: 31070727 DOI: 10.1210/en.2019-00111] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/03/2019] [Indexed: 11/19/2022]
Abstract
In this article, we briefly review the identification of GHRH, provide an abridged overview of GHRH antagonists, and focus on studies with GHRH agonists. Potent GHRH agonists of JI and MR class were synthesized and evaluated biologically. Besides the induction of the release of pituitary GH, GHRH analogs promote cell proliferation and exert stimulatory effects on various tissues, which express GHRH receptors (GHRH-Rs). A large body of work shows that GHRH agonists, such as MR-409, improve pancreatic β-cell proliferation and metabolic functions and facilitate engraftment of islets after transplantation in rodents. Accordingly, GHRH agonists offer a new therapeutic approach to treating diabetes. Various studies demonstrate that GHRH agonists promote repair of cardiac tissue, producing improvement of ejection fraction and reduction of infarct size in rats, reduction of infarct scar in swine, and attenuation of cardiac hypertrophy in mice, suggesting clinical applications. The presence of GHRH-Rs in ocular tissues and neuroprotective effects of GHRH analogs in experimental diabetic retinopathy indicates their possible therapeutic applications for eye diseases. Other effects of GHRH agonists, include acceleration of wound healing, activation of immune cells, and action on the central nervous system. As GHRH might function as a growth factor, we examined effects of GHRH agonists on tumors. In vitro, GHRH agonists stimulate growth of human cancer cells and upregulate GHRH-Rs. However, in vivo, GHRH agonists inhibit growth of human cancers xenografted into nude mice and downregulate pituitary and tumoral GHRH-Rs. Therapeutic applications of GHRH analogs are discussed. The development of GHRH analogs should lead to their clinical use.
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Affiliation(s)
- Andrew V Schally
- Veterans Affairs Medical Center, Miami, Florida
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida
- Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida
| | - Xianyang Zhang
- Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Renzhi Cai
- Veterans Affairs Medical Center, Miami, Florida
| | - Joshua M Hare
- Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Riccarda Granata
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Manuela Bartoli
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia
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7
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Inhibition of tumor growth by agonists of growth hormone-releasing hormone. Proc Natl Acad Sci U S A 2018; 115:11876-11878. [PMID: 30404912 DOI: 10.1073/pnas.1817342115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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8
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Yang S, Fan T, Hu Q, Xu W, Yang J, Xu C, Zhang B, Chen J, Jiang H. Downregulation of microRNA-17-5p improves cardiac function after myocardial infarction via attenuation of apoptosis in endothelial cells. Mol Genet Genomics 2018. [PMID: 29536180 PMCID: PMC6061060 DOI: 10.1007/s00438-018-1426-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
MicroRNA-17-5p (miR-17-5p) was indicated to suppress the formation of blood vessels, which is associated with cardiac function after myocardial infarction. In this study, the relationship between miR-17-5p and cardiac function was researched. Human umbilical vein endothelial cells were infected with adenoviruses. Apoptosis was determined by Annexin V-7AAD/PI. Real-time RT-PCR was used to evaluate miR-17-5p and ERK levels. Western blotting was used to determine the levels of ERK, the anti-apoptosis protein bcl-2 and apoptosis proteins, including bax, caspase 3, and caspase 9. An in vivo acute myocardial infarction (AMI) model was established in SD male rats. Heart function was evaluated by echocardiography prior to inducing AMI and after 7 and 28 days later. The heart was removed to perform histological examination, real-time RT-PCR, and western blotting, as described above. The result indicated that the ERK pathway was activated by miR-17-5p downregulation and an increase in the level of the anti-apoptosis protein bcl-2; however, the levels of apoptosis proteins (bax/caspase 3/caspase 9) were decreased. The results were completely reversed when miR-17-5p was up-regulated. At 7 and 28 days after the induction of AMI, in the miR-17-5p inhibition group, the infarction areas and collagen fibers were decreased, apoptosis in cardiac tissues was inhibited, and the endothelial growth process was promoted. Therefore, MiR-17-5p silencing protects heart function after AMI through decreasing the rate of apoptosis and repairing vascular injury.
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Affiliation(s)
- Shuo Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, 238 JieFang Road, Wuhan, 430060, China
| | - Tao Fan
- Department of Thoracic Surgery, Remin Hospital of Wuhan University, Wuhan, China
| | - Qi Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, 238 JieFang Road, Wuhan, 430060, China
| | - Weipan Xu
- Department of Cardiology, Huangshi Central Hospital, Huangshi, China
| | - Jian Yang
- Department of Cardiology, Yichang Central People's Hospital, Yichang, China
| | - Changwu Xu
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, 238 JieFang Road, Wuhan, 430060, China
| | - Bofang Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, 238 JieFang Road, Wuhan, 430060, China
| | - Jing Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, 238 JieFang Road, Wuhan, 430060, China
| | - Hong Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, 238 JieFang Road, Wuhan, 430060, China.
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9
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Growth hormone-releasing hormone attenuates cardiac hypertrophy and improves heart function in pressure overload-induced heart failure. Proc Natl Acad Sci U S A 2017; 114:12033-12038. [PMID: 29078377 PMCID: PMC5692579 DOI: 10.1073/pnas.1712612114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pathological cardiac hypertrophy, characterized by heart growth in response to pressure or volume overload, such as in the setting of hypertension, is the main risk factor for heart failure (HF). The identification of therapeutic strategies to prevent or reverse cardiac hypertrophy is therefore a priority for curing HF. It is known that growth hormone-releasing hormone (GHRH) displays cardioprotective functions; however, its therapeutic potential in hypertrophy and HF is unknown. Here we show that GHRH reduces cardiomyocyte hypertrophy in vitro through inhibition of hypertrophic pathways. In vivo, the GHRH analog MR-409 attenuates cardiac hypertrophy in mice subjected to transverse aortic constriction and improves cardiac function. These findings suggest therapeutic use of GHRH analogs for treatment of pathological cardiac hypertrophy and HF. It has been shown that growth hormone-releasing hormone (GHRH) reduces cardiomyocyte (CM) apoptosis, prevents ischemia/reperfusion injury, and improves cardiac function in ischemic rat hearts. However, it is still not known whether GHRH would be beneficial for life-threatening pathological conditions, like cardiac hypertrophy and heart failure (HF). Thus, we tested the myocardial therapeutic potential of GHRH stimulation in vitro and in vivo, using GHRH or its agonistic analog MR-409. We show that in vitro, GHRH(1-44)NH2 attenuates phenylephrine-induced hypertrophy in H9c2 cardiac cells, adult rat ventricular myocytes, and human induced pluripotent stem cell-derived CMs, decreasing expression of hypertrophic genes and regulating hypertrophic pathways. Underlying mechanisms included blockade of Gq signaling and its downstream components phospholipase Cβ, protein kinase Cε, calcineurin, and phospholamban. The receptor-dependent effects of GHRH also involved activation of Gαs and cAMP/PKA, and inhibition of increase in exchange protein directly activated by cAMP1 (Epac1). In vivo, MR-409 mitigated cardiac hypertrophy in mice subjected to transverse aortic constriction and improved cardiac function. Moreover, CMs isolated from transverse aortic constriction mice treated with MR-409 showed improved contractility and reversal of sarcolemmal structure. Overall, these results identify GHRH as an antihypertrophic regulator, underlying its therapeutic potential for HF, and suggest possible beneficial use of its analogs for treatment of pathological cardiac hypertrophy.
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10
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Hypothalamic dysfunction in heart failure: pathogenetic mechanisms and therapeutic implications. Heart Fail Rev 2017; 23:55-61. [DOI: 10.1007/s10741-017-9659-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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11
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GHSR-1a is a novel pro-angiogenic and anti-remodeling target in rats after myocardial infarction. Eur J Pharmacol 2016; 788:218-225. [DOI: 10.1016/j.ejphar.2016.06.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 12/19/2022]
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12
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Growth Hormone-Releasing Hormone and Its Analogues: Significance for MSCs-Mediated Angiogenesis. Stem Cells Int 2016; 2016:8737589. [PMID: 27774107 PMCID: PMC5059609 DOI: 10.1155/2016/8737589] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 06/19/2016] [Accepted: 07/03/2016] [Indexed: 02/08/2023] Open
Abstract
Mesenchymal stromal cells (MSCs) are promising candidates for regenerative medicine because of their multipotency, immune-privilege, and paracrine properties including the potential to promote angiogenesis. Accumulating evidence suggests that the inherent properties of cytoprotection and tissue repair by native MSCs can be enhanced by various preconditioning stimuli implemented prior to cell transplantation. Growth hormone-releasing hormone (GHRH), a stimulator in extrahypothalamus systems including tumors, has attracted great attentions in recent years because GHRH and its agonists could promote angiogenesis in various tissues. GHRH and its agonists are proangiogenic in responsive tissues including tumors, and GHRH antagonists have been tested as antitumor agents through their ability to suppress angiogenesis and cell growth. GHRH-R is expressed by MSCs and evolving work from our laboratory indicates that treatment of MSCs with GHRH agonists prior to cell transplantation markedly enhanced the angiogenic potential and tissue reparative properties of MSCs through a STAT3 signaling pathway. In this review we summarized the possible effects of GHRH analogues on cell growth and development, as well as on the proangiogenic properties of MSCs. We also discussed the relationship between GHRH analogues and MSC-mediated angiogenesis. The analyses provide new insights into molecular pathways of MSCs-based therapies and their augmentation by GHRH analogues.
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13
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Kiscsatári L, Varga Z, Schally AV, Gáspár R, Nagy CT, Giricz Z, Ferdinandy P, Fábián G, Kahán Z, Görbe A. Protection of neonatal rat cardiac myocytes against radiation-induced damage with agonists of growth hormone-releasing hormone. Pharmacol Res 2016; 111:859-866. [PMID: 27480202 DOI: 10.1016/j.phrs.2016.07.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 07/05/2016] [Accepted: 07/25/2016] [Indexed: 12/15/2022]
Abstract
Despite the great clinical significance of radiation-induced cardiac damage, experimental investigation of its mechanisms is an unmet need in medicine. Beneficial effects of growth hormone-releasing hormone (GHRH) agonists in regeneration of the heart have been demonstrated. The aim of this study was the evaluation of the potential of modern GHRH agonistic analogs in prevention of radiation damage in an in vitro cardiac myocyte-based model. Cultures of cardiac myocytes isolated from newborn rats (NRVM) were exposed to a radiation dose of 10Gy. The effects of the agonistic analogs, JI-34 and MR-356, of human GHRH on cell viability, proliferation, their mechanism of action and the protein expression of the GHRH/SV1 receptors were studied. JI-34 and MR-356, had no effect on cell viability or proliferation in unirradiated cultures. However, in irradiated cells JI-34 showed protective effects on cell viability at concentrations of 10 and 100nM, and MR-356 at 500nM; but no such protective effect was detected on cell proliferation. Both agonistic analogs decreased radiation-induced ROS level and JI-34 interfered with the activation of SAFE/RISK pathways. Using Western blot analysis, a 52kDa protein isoform of GHRHR was detected in the samples in both irradiated and unirradiated cells. Since GHRH agonistic analogs, JI-34 and MR-356 alleviated radiation-induced damage of cardiac myocytes, they should be tested in vivo as potential protective agents against radiogenic heart damage.
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Affiliation(s)
- Laura Kiscsatári
- Department of Oncotherapy, University of Szeged, Szeged, Hungary
| | - Zoltán Varga
- Department of Oncotherapy, University of Szeged, Szeged, Hungary
| | - Andrew V Schally
- Veterans Affairs Medical Center, Miami FL, USA and Departments of Pathology and Medicine, Divisions of Hematology/Oncology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Renáta Gáspár
- Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Szeged, Hungary; Pharmahungary Group, Szeged, Hungary
| | - Csilla Terézia Nagy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Zoltán Giricz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Péter Ferdinandy
- Pharmahungary Group, Szeged, Hungary; Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Gabriella Fábián
- Department of Oncotherapy, University of Szeged, Szeged, Hungary
| | - Zsuzsanna Kahán
- Department of Oncotherapy, University of Szeged, Szeged, Hungary
| | - Anikó Görbe
- Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Szeged, Hungary; Pharmahungary Group, Szeged, Hungary; Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.
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14
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Granata R. Peripheral activities of growth hormone-releasing hormone. J Endocrinol Invest 2016; 39:721-7. [PMID: 26891937 DOI: 10.1007/s40618-016-0440-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/03/2016] [Indexed: 12/21/2022]
Abstract
Growth hormone (GH)-releasing hormone (GHRH) is produced by the hypothalamus and stimulates GH synthesis and release in the anterior pituitary gland. In addition to its endocrine role, GHRH exerts a wide range of extrapituitary effects which include stimulation of cell proliferation, survival and differentiation, and inhibition of apoptosis. Accordingly, expression of GHRH, as well as the receptor GHRH-R and its splice variants, has been demonstrated in different peripheral tissues and cell types. Among the direct peripheral activities, GHRH regulates pancreatic islet and β-cell survival and function and endometrial cell proliferation, promotes cardioprotection and wound healing, influences the immune and reproductive systems, reduces inflammation, indirectly increases lifespan and adiposity and acts on skeletal muscle cells to inhibit cell death and atrophy. Therefore, it is becoming increasingly clear that GHRH exerts important extrapituitary functions, suggesting potential therapeutic use of the peptide and its analogs in a wide range of medical settings.
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Affiliation(s)
- R Granata
- Lab of Molecular and Cellular Endocrinology, Division of Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Torino, Corso Dogliotti, 14, 10126, Turin, Italy.
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15
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Fridlyand LE, Tamarina NA, Schally AV, Philipson LH. Growth Hormone-Releasing Hormone in Diabetes. Front Endocrinol (Lausanne) 2016; 7:129. [PMID: 27777568 PMCID: PMC5056186 DOI: 10.3389/fendo.2016.00129] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 09/06/2016] [Indexed: 12/13/2022] Open
Abstract
Growth hormone-releasing hormone (GHRH) is produced by the hypothalamus and stimulates growth hormone synthesis and release in the anterior pituitary gland. In addition, GHRH is an important regulator of cellular functions in many cells and organs. Expression of GHRH G-Protein Coupled Receptor (GHRHR) has been demonstrated in different peripheral tissues and cell types, including pancreatic islets. Among the peripheral activities, recent studies demonstrate a novel ability of GHRH analogs to increase and preserve insulin secretion by beta-cells in isolated pancreatic islets, which makes them potentially useful for diabetes treatment. This review considers the role of GHRHR in the beta-cell and addresses the unique engineered GHRH agonists and antagonists for treatment of type 2 diabetes mellitus. We discuss the similarity of signaling pathways activated by GHRHR in pituitary somatotrophs and in pancreatic beta-cells and possible ways as to how the GHRHR pathway can interact with glucose and other secretagogues to stimulate insulin secretion. We also consider the hypothesis that novel GHRHR agonists can improve glucose metabolism in Type 2 diabetes by preserving the function and survival of pancreatic beta-cells. Wound healing and cardioprotective action with new GHRH agonists suggest that they may prove useful in ameliorating certain diabetic complications. These findings highlight the future potential therapeutic effectiveness of modulators of GHRHR activity for the development of new therapeutic approaches in diabetes and its complications.
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Affiliation(s)
- Leonid E. Fridlyand
- Department of Medicine, Kovler Diabetes Center, The University of Chicago, Chicago, IL, USA
- *Correspondence: Leonid E. Fridlyand,
| | - Natalia A. Tamarina
- Department of Medicine, Kovler Diabetes Center, The University of Chicago, Chicago, IL, USA
| | - Andrew V. Schally
- VA Medical Center, Miami, FL, USA
- Department of Pathology and Medicine, Division of Endocrinology and Hematology-Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Louis H. Philipson
- Department of Medicine, Kovler Diabetes Center, The University of Chicago, Chicago, IL, USA
- Department of Pediatrics, The University of Chicago, Chicago, IL, USA
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Bagno LL, Kanashiro-Takeuchi RM, Suncion VY, Golpanian S, Karantalis V, Wolf A, Wang B, Premer C, Balkan W, Rodriguez J, Valdes D, Rosado M, Block NL, Goldstein P, Morales A, Cai RZ, Sha W, Schally AV, Hare JM. Growth hormone-releasing hormone agonists reduce myocardial infarct scar in swine with subacute ischemic cardiomyopathy. J Am Heart Assoc 2015; 4:jah3883. [PMID: 25827134 PMCID: PMC4579962 DOI: 10.1161/jaha.114.001464] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Growth hormone-releasing hormone agonists (GHRH-As) stimulate cardiac repair following myocardial infarction (MI) in rats through the activation of the GHRH signaling pathway within the heart. We tested the hypothesis that the administration of GHRH-As prevents ventricular remodeling in a swine subacute MI model. METHODS AND RESULTS Twelve female Yorkshire swine (25 to 30 kg) underwent transient occlusion of the left anterior descending coronary artery (MI). Two weeks post MI, swine were randomized to receive injections of either 30 μg/kg GHRH-A (MR-409) (GHRH-A group; n=6) or vehicle (placebo group; n=6). Cardiac magnetic resonance imaging and pressure-volume loops were obtained at multiple time points. Infarct, border, and remote (noninfarcted) zones were assessed for GHRH receptor by immunohistochemistry. Four weeks of GHRH-A treatment resulted in reduced scar mass (GHRH-A: -21.9 ± 6.42%; P=0.02; placebo: 10.9 ± 5.88%; P=0.25; 2-way ANOVA; P=0.003), and scar size (percentage of left ventricular mass) (GHRH-A: -38.38 ± 4.63; P=0.0002; placebo: -14.56 ± 6.92; P=0.16; 2-way ANOVA; P=0.02). This was accompanied by improved diastolic strain. Unlike in rats, this reduced infarct size in swine was not accompanied by improved cardiac function as measured by serial hemodynamic pressure-volume analysis. GHRH receptors were abundant in cardiac tissue, with a greater density in the border zone of the GHRH-A group compared with the placebo group. CONCLUSIONS Daily subcutaneous administration of GHRH-A is feasible and safe in a large animal model of subacute ischemic cardiomyopathy. Furthermore, GHRH-A therapy significantly reduced infarct size and improved diastolic strain, suggesting a local activation of the GHRH pathway leading to the reparative process.
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Affiliation(s)
- Luiza L Bagno
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Rosemeire M Kanashiro-Takeuchi
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.) Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL (R.M.K.T., C.P., J.M.H.)
| | - Viky Y Suncion
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Samuel Golpanian
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Vasileios Karantalis
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Ariel Wolf
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Bo Wang
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Courtney Premer
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.) Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL (R.M.K.T., C.P., J.M.H.)
| | - Wayne Balkan
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Jose Rodriguez
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - David Valdes
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Marcos Rosado
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.)
| | - Norman L Block
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL (N.L.B., A.M., R.Z.C., W.S., A.V.S., J.M.H.) Bruce A. Carter Miami Veterans Affairs Healthcare System, Miami, FL (N.L.B., R.Z.C., W.S., A.V.S.)
| | | | - Azorides Morales
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL (N.L.B., A.M., R.Z.C., W.S., A.V.S., J.M.H.)
| | - Ren-Zhi Cai
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL (N.L.B., A.M., R.Z.C., W.S., A.V.S., J.M.H.) Bruce A. Carter Miami Veterans Affairs Healthcare System, Miami, FL (N.L.B., R.Z.C., W.S., A.V.S.)
| | - Wei Sha
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL (N.L.B., A.M., R.Z.C., W.S., A.V.S., J.M.H.) Bruce A. Carter Miami Veterans Affairs Healthcare System, Miami, FL (N.L.B., R.Z.C., W.S., A.V.S.)
| | - Andrew V Schally
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL (N.L.B., A.M., R.Z.C., W.S., A.V.S., J.M.H.) Bruce A. Carter Miami Veterans Affairs Healthcare System, Miami, FL (N.L.B., R.Z.C., W.S., A.V.S.)
| | - Joshua M Hare
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL (L.L.B., R.M.K.T., V.Y.S., S.G., V.K., A.W., B.W., C.P., W.B., J.R., D.V., M.R., J.M.H.) Department of Medicine, University of Miami Miller School of Medicine, Miami, FL (N.L.B., A.M., R.Z.C., W.S., A.V.S., J.M.H.) Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL (R.M.K.T., C.P., J.M.H.)
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