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Cai R, Schally AV, Cui T, Szalontay L, Halmos G, Sha W, Kovacs M, Jaszberenyi M, He J, Rick FG, Popovics P, Kanashiro-Takeuchi R, Hare JM, Block NL, Zarandi M. Synthesis of new potent agonistic analogs of growth hormone-releasing hormone (GHRH) and evaluation of their endocrine and cardiac activities. Peptides 2014; 52:104-12. [PMID: 24373935 PMCID: PMC4745889 DOI: 10.1016/j.peptides.2013.12.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 11/30/2022]
Abstract
In view of the recent findings of stimulatory effects of GHRH analogs, JI-34, JI-36 and JI-38, on cardiomyocytes, pancreatic islets and wound healing, three series of new analogs of GHRH(1-29) have been synthesized and evaluated biologically in an endeavor to produce more potent compounds. "Agmatine analogs", MR-356 (N-Me-Tyr(1)-JI-38), MR-361(N-Me-Tyr(1), D-Ala(2)-JI-38) and MR-367(N-Me-Tyr(1), D-Ala(2), Asn(8)-JI-38), in which Dat in JI-38 is replaced by N-Me-Tyr(1), showed improved relative potencies on GH release upon subcutaneous administration in vivo and binding in vitro. Modification with N-Me-Tyr(1) and Arg(29)-NHCH3 as in MR-403 (N-Me-Tyr(1), D-Ala(2), Arg(29)-NHCH3-JI-38), MR-406 (N-Me-Tyr(1), Arg(29)-NHCH3-JI-38) and MR-409 (N-Me-Tyr(1), D-Ala(2), Asn(8), Arg(29)-NHCH3-JI-38), and MR-410 (N-Me-Tyr(1), D-Ala(2), Thr(8), Arg(29)-NHCH3-JI-38) resulted in dramatically increased endocrine activities. These appear to be the most potent GHRH agonistic analogs so far developed. Analogs with Apa(30)-NH2 such as MR-326 (N-Me-Tyr(1), D-Ala(2), Arg(29), Apa(30)-NH2-JI-38), and with Gab(30)-NH2, as MR-502 (D-Ala(2), 5F-Phe(6), Ser(28), Arg(29),Gab(30)-NH2-JI-38) also exhibited much higher potency than JI-38 upon i.v. administration. The relationship between the GH-releasing potency and the analog structure is discussed. Fourteen GHRH agonists with the highest endocrine potencies were subjected to cardiologic tests. MR-409 and MR-356 exhibited higher potency than JI-38 in activating myocardial repair in rats with induced myocardial infarction. As the previous class of analogs, exemplified by JI-38, had shown promising results in multiple fields including cardiology, diabetes and wound healing, our new, more potent, GHRH agonists should manifest additional efficacy for possible medical applications.
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Affiliation(s)
- Renzhi Cai
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Andrew V Schally
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States; Division of Hematology/Oncology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States.
| | - Tengjiao Cui
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Luca Szalontay
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States
| | - Gabor Halmos
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Wei Sha
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Interdisciplinary Stem Cell Institute, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Magdolna Kovacs
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Miklos Jaszberenyi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States
| | - Jinlin He
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States
| | - Ferenc G Rick
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Urology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL, United States
| | - Petra Popovics
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; Division of Cardiology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Rosemeire Kanashiro-Takeuchi
- Interdisciplinary Stem Cell Institute, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Joshua M Hare
- Division of Cardiology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States; Interdisciplinary Stem Cell Institute, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Norman L Block
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States; Division of Hematology/Oncology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Marta Zarandi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
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Toth K, Kovacs M, Zarandi M, Halmos G, Groot K, Nagy A, Kele Z, Schally AV. New analogs of human growth hormone-releasing hormone (1-29) with high and prolonged antagonistic activity. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1998; 51:134-41. [PMID: 9516049 DOI: 10.1111/j.1399-3011.1998.tb00631.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Based on our previous results, in conjunction with various structural considerations, 19 new analogs of the GHRH antagonist [PhAc-Tyr1,D-Arg2,Phe(pCl)6,Abu15,Nle27,Agm29]++ +hGHRH(1-29) (MZ-5-156) were synthesized by the solid-phase method. These compounds were designed to develop further analogs of this class with increased receptor-binding affinity. All analogs had Abu15 and Nle27 modifications and were acylated with phenylacetic acid at the N-terminus. Most of the analogs had D-Arg2 and Phe(pCl)6 substituents and Agm29 or Arg29-NH2 at the C-terminus. Additional single substitutions consisted of the incorporation of D- or L-Tic1, D-Tic2, Tic6 or Phe(pNO2)6 and Arg29-NH2. The Arg29-NH2 analog of MZ-5-156 (KT-48) was further modified by single substitutions using Pal1; D-Tpi2; D- or L-Phe4; Phe(pX)6 X = F, Cl, I; Tyr7; Aib8; Tyr(Me)10 or Phe(pCl)10. Four peptides had multiple substitutions. All the analogs were evaluated for their ability to inhibit GH release induced by hGHRH(1-29)NH2 in vitro and some were also tested in vivo. Peptides [PhAc-Tyr1,D-Arg2,Phe(pI)6,Abu15,Nle27]hGHRH(1-2 9)NH2 (KT-30), [PhAc-Tyr1,D-Arg2,Phe(pCl)6,Aib8,Abu15,Nle27] hGHRH(1-29)NH2 (KT-50) and [PhAc-Tyr1,D-Arg2,Phe(pCl)6,Tyr(Me)10,Abu15,Nle27]h GHRH(1-29)NH2 (KT-40) with Phe(pI)6, Aib8 or Tyr(Me)10 modifications, respectively, showed high and prolonged inhibitory effect in superfused rat pituitary system. Analog KT-50 also exhibited a strong and long-term inhibitory activity in vivo in rats. Most of the new analogs showed high binding affinities to rat pituitary GHRH receptors.
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Affiliation(s)
- K Toth
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70146, USA
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Izdebski J, Pinski J, Horvath JE, Halmos G, Groot K, Schally AV. Synthesis and biological evaluation of superactive agonists of growth hormone-releasing hormone. Proc Natl Acad Sci U S A 1995; 92:4872-6. [PMID: 7761415 PMCID: PMC41809 DOI: 10.1073/pnas.92.11.4872] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Analogs of the 29 amino acid sequence of human growth hormone-releasing hormone (hGH-RH) with agmatine (Agm) in position 29, desaminotyrosine (Dat) in position 1, norleucine (Nle) in position 27, and L-alpha-aminobutyric acid (Abu) in position 15 have been synthesized, and their biological activity was evaluated. Some peptides contained one or two residues of ornithine (Orn) instead of Lys in positions 12 and 21 and additional replacements in positions 8 and 28. All analogs were found to be more potent than hGH-RH-(1-29)-NH2 in the superfused rat pituitary cell system. In tests in vivo in rats after subcutaneous administration, the analogs JI-22, [Dat1, Orn12,21, Abu15, Nle27, Agm29]hGH-RH-(1-29); JI-34, [Dat1, Orn12,21,Abu15,Nle27, Asp28, Agm29]hGH-RH-(1-29); JI-36, [Dat1, Thr8, Orn12,21, Abu15,Nle27,Asp28,Agm29]hGH-RH-(1-29); and JI-38, [Dat1,Gln8, Orn12,21,Abu15,Nle27,Asp28,Agm29]hGH-RH-(1 -29) displayed a potency 44.6,80.9,95.8, and 71.4 times greater, respectively, than that of hGH-RH-(1-29)-NH2 at 15 min and 217.1, 89.7, 87.9, and 116.8 times greater at 30 min. After intravenous administration, JI-22, JI-36, and JI-38 were 3.2-3.8 times more potent than hGH-RH-(1-29)-NH2 at 5 min and 6.1-8.5 times more active at 15 min. All analogs were found to have higher binding affinities for GH-RH receptors on rat pituitary cells than hGH-RH-(1-29)-NH2. Because of high activity and greater stability, these analogs could be considered for therapy of patients with growth hormone deficiency.
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Affiliation(s)
- J Izdebski
- Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70146, USA
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Zarandi M, Horvath JE, Halmos G, Pinski J, Nagy A, Groot K, Rekasi Z, Schally AV. Synthesis and biological activities of highly potent antagonists of growth hormone-releasing hormone. Proc Natl Acad Sci U S A 1994; 91:12298-302. [PMID: 7991622 PMCID: PMC45424 DOI: 10.1073/pnas.91.25.12298] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In the search for antagonists of human growth hormone-releasing hormone (hGHRH) with high activity, 22 analogs were synthesized by solid-phase methods, purified, and tested biologically. Within the N-terminal sequence of 28 or 29 amino acids of hGHRH, all the analogs contained D-Arg2, Phe(4-Cl)6 (para-chlorophenylalanine), Abu15 (alpha-aminobutyric acid), and Nle27 and most of them had Agm29 (agmatine) substituents. All the peptides, except one, were acylated at the N terminus with different hydrophobic acids--e.g., isobutyric acid (Ibu) or 1-naphthylacetic acid (Nac) in order to study the effect of N-terminal acylation on the antagonistic activity. In the superfused rat pituitary cell system, all the analogs inhibited more powerfully the GHRH-induced growth hormone (GH) release than the standard GHRH antagonist [Ac-Tyr1,D-Arg2]hGHRH-(1-29)NH2. Antagonists [Ibu0,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]hGHRH-(1-28) Agm (MZ-4-71), [Nac0,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]hGHRH-(1-28) Agm (MZ-4-243), [Nac0,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]hGHRH-(1-29) NH2 (MZ-4-169), [Nac0-His1,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]-hGH RH-(1-29)NH2 (MZ-4-181), and [Nac0,D-Arg2,Phe(4-Cl)6,Abu15,Nle27,Asp28]hGH RH-(1-28)Agm (MZ-4-209) inhibited GH release at 3 x 10(-9) M. Among these peptides, MZ-4-243, MZ-4-169, and MZ-4-181 were also long acting in vitro. Antagonist MZ-4-243 inhibited GH release 100 times more powerfully than the standard antagonist and was the most potent in vitro among GHRH antagonists synthesized. Analogs with high inhibitory effects in vitro were also found to have high affinities to rat pituitary GHRH receptors. In experiments in vivo, antagonists [Ibu0,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]-hGHRH-(1-28 )Agm (MZ-4-71), [Nac0,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]hGHRH-(1-29) NH2 (MZ-4-169), and [Nac0-His1,D-Arg2,Phe(4-Cl)6,Abu15,Nle27]hGHR H-(1-29)NH2 (MZ-4-181) induced a significantly greater inhibition of GH release than the standard antagonist. In view of their high antagonistic activity and prolonged duration of action, some of these antagonists of GHRH may find clinical applications, including treatment of certain endocrine disorders and insulin-like growth factor I-dependent tumors.
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Affiliation(s)
- M Zarandi
- Veterans Affairs Medical Center, Endocrine, Polypeptide and Cancer Institute, New Orleans, LA
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