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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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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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