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Siqueira BS, Díaz Urrutia MA, Ceglarek VM, Moreira DC, Brasil Kuzniewski FT, Roberto de Souza de Almeida Leite J, Grassiolli S. A novel bombesin-related peptide modulates glucose tolerance and insulin secretion in non-obese and hypothalamic-obese rats. Toxicon 2025; 255:108230. [PMID: 39788326 DOI: 10.1016/j.toxicon.2025.108230] [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: 10/14/2024] [Revised: 12/10/2024] [Accepted: 01/06/2025] [Indexed: 01/12/2025]
Abstract
This study investigated the effects of a novel bombesin-related peptide (BR-b), derived from the skin of the Chaco tree frog (Boana raniceps), on glucose homeostasis in non-obese and hypothalamic-obese male rats. Hypothalamic obesity was induced in neonatal rats through high-dose administration of monosodium glutamate (MSG; 4 g/kg), while control animals (CTL) received an equimolar saline solution. At 70 days of age, both MSG and CTL groups underwent an oral glucose tolerance test (OGTT; 2 g/kg) with or without prior intraperitoneal administration of BR-b at doses of 0.5 or 1.0 mg/kg, delivered 5 min before the glucose challenge. At 75 days of age, pancreatic islets were isolated and exposed to glucose in the presence or absence of BR-b (1.0 or 5.0 μM). MSG-treated rats developed obesity, hyperinsulinemia, and insulin resistance. BR-b administration exacerbated glucose intolerance during the OGTT, particularly at the 1.0 mg/kg dose, with more pronounced effects observed in the CTL group. Insulin secretion from pancreatic islets was influenced by both obesity status and glucose concentration. In islets from CTL rats, BR-b (5 μM) reduced insulin release under non-stimulatory glucose conditions but enhanced insulin secretion at stimulatory glucose levels. Conversely, in islets from MSG-obese rats, BR-b exhibited an inhibitory effect on insulin release at basal glucose concentrations, while the insulinotropic response to high glucose was abolished. In summary, BR-b administration shortly before the OGTT impaired glucose tolerance and modulated insulin secretion from pancreatic islets in a glucose-dependent manner in non-obese rats. These effects were attenuated or absent in MSG-obese rats, indicating that hypothalamic obesity alters the metabolic responses to bombesin-related peptides.
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Affiliation(s)
- Bruna Schumaker Siqueira
- Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação em Biociências e Saúde (PPG-BCS), Cascavel, Brazil.
| | - Marianela Andrea Díaz Urrutia
- Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação em Biociências e Saúde (PPG-BCS), Cascavel, Brazil.
| | - Vanessa Marieli Ceglarek
- Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Porto Alegre, Brazil.
| | - Daniel Carneiro Moreira
- Núcleo de Pesquisa em Morfologia e Imunologia Aplicada, NuPMIA, Faculdade de Medicina, FM, Universidade de Brasília, Brasília, Brazil.
| | - Felipe Torres Brasil Kuzniewski
- Núcleo de Pesquisa em Morfologia e Imunologia Aplicada, NuPMIA, Faculdade de Medicina, FM, Universidade de Brasília, Brasília, Brazil.
| | | | - Sabrina Grassiolli
- Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação em Biociências e Saúde (PPG-BCS), Cascavel, Brazil
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Li C, Xu Y, Su W, He X, Li J, Li X, Xu HE, Yin W. Structural insights into ligand recognition, selectivity, and activation of bombesin receptor subtype-3. Cell Rep 2024; 43:114511. [PMID: 39024101 DOI: 10.1016/j.celrep.2024.114511] [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: 02/16/2024] [Revised: 05/16/2024] [Accepted: 06/28/2024] [Indexed: 07/20/2024] Open
Abstract
Bombesin receptor subtype-3 (BRS3) is an important orphan G protein-coupled receptor that regulates energy homeostasis and insulin secretion. As a member of the bombesin receptor (BnR) family, the lack of known endogenous ligands and high-resolution structure has hindered the understanding of BRS3 signaling and function. We present two cryogenic electron microscopy (cryo-EM) structures of BRS3 in complex with the heterotrimeric Gq protein in its active states: one bound to the pan-BnR agonist BA1 and the other bound to the synthetic BRS3-specific agonist MK-5046. These structures reveal the architecture of the orthosteric ligand pocket underpinning molecular recognition and provide insights into the structural basis for BRS3's selectivity and low affinity for bombesin peptides. Examination of conserved micro-switches suggests a shared activation mechanism among BnRs. Our findings shed light on BRS3's ligand selectivity and signaling mechanisms, paving the way for exploring its therapeutic potential for diabetes, obesity, and related metabolic disorders.
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Affiliation(s)
- Changyao Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Lingang Laboratory, Shanghai 200031, China
| | - Youwei Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Wenxin Su
- Guangzhou University of Chinese Medicine, Zhongshan Institute for Drug Discovery, Guangdong 510000, China; Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Guangdong 528400, China
| | - Xinheng He
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingru Li
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Xinzhu Li
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - H Eric Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Lingang Laboratory, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Wanchao Yin
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Guangdong 528400, China; State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; Guangzhou University of Chinese Medicine, Zhongshan Institute for Drug Discovery, Guangdong 510000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Bombesin Receptor Subtype-3 in Human Diseases. Arch Med Res 2020; 50:463-467. [PMID: 31911345 DOI: 10.1016/j.arcmed.2019.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 11/11/2019] [Accepted: 11/14/2019] [Indexed: 01/26/2023]
Abstract
This review summarizes the recent findings of the roles of bombesin receptor subtype-3 (BRS-3) in various patho-physiological conditions. Studies have demonstrated that two mammalians bombesin-like peptides, GRP and NMB, exhibit a large range of functions by binding to three receptors. Knockout studies showed that the mice BRS-3 has important effects on tumor growth, energy homeostasis, glucose regulation, satiety, and lung development (1,7). BRS-3 is an orphan receptor whose natural ligand is unknown. However, several agonists and antagonists have been synthesized which facilitate its characterization, (D-Tyr6, β-Ala11, Phe13, Nle14) Bn-(6-14) and MK-5046 are agonists, whereas ML-18 and Bantag-1 are antagonists. With the development of several selective, high-affinity BRS-3 agonists and antagonists, recent studies provided some insights into the biological effects of BRS-3 in several disease states including lung cancer, obesity, diabetes mellitus, asthma, and kidney diseases.
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Ramos-Alvarez I, Lee L, Mantey SA, Jensen RT. Development and Characterization of a Novel, High-Affinity, Specific, Radiolabeled Ligand for BRS-3 Receptors. J Pharmacol Exp Ther 2019; 369:454-465. [PMID: 30971479 PMCID: PMC6519687 DOI: 10.1124/jpet.118.255141] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/05/2019] [Indexed: 02/06/2023] Open
Abstract
Bombesin (Bn) receptor subtype 3(BRS-3) is an orphan G-protein-coupled receptor of the Bn family, which does not bind any natural Bn peptide with high affinity. Receptor knockout studies show that the animals develop diabetes, obesity, altered temperature control, and other central nervous system (CNS)/endocrine/gastrointestinal changes. It is present in CNS, peripheral tissues, and tumors; however, its role in normal physiology/pathophysiology, as well as its receptor localization/pharmacology is largely unknown, in part due to the lack of a convenient, specific, direct radiolabeled ligand. This study was designed to address this problem and to develop and characterize a specific radiolabeled ligand for BRS-3. The peptide antagonist Bantag-1 had >10,000-fold selectivity for human BRS-3 (hBRS-3) over other mammalian Bn receptors (BnRs) [i.e., gastrin-releasing peptide receptor (GRPR) and neuromedin B receptor (NMBR)]. Using iodogen and basic conditions, it was radiolabeled to high specific activity (2200 Ci/mmol) and found to bind with high affinity/specificity to hBRS-3. Binding was saturable, rapid, and reversible. The ligand only interacted with known BRS-3 ligands, and not with other specific GRPR/NMBR ligands or ligands for unrelated receptors. The magnitude of 125I-Bantag-1 binding correlated with BRS-3 mRNA expression and the magnitude of activation of phospholipase C in lung cancer cells, as well as readily identifying BRS-3 in lung cancer cells and normal tissues, allowing the direct assessment of BRS-3 receptor pharmacology/numbers on cells containing BRS-3 with other BnRs, which is usually the case. This circumvents the need for subtraction assays, which are now frequently used to assess BRS-3 indirectly using radiolabeled pan-ligands, which interact with all BnRs.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Samuel A Mantey
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Robert T Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Moreno-Villegas Z, Martín-Duce A, Aparicio C, Portal-Núñez S, Sanz R, Mantey SA, Jensen RT, Lorenzo O, Egido J, González N. Activation of bombesin receptor Subtype-3 by [D-Tyr 6,β-Ala 11,Phe 13,Nle 14]bombesin 6-14 increased glucose uptake and lipogenesis in human and rat adipocytes. Mol Cell Endocrinol 2018; 474:10-19. [PMID: 29402494 DOI: 10.1016/j.mce.2018.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 12/20/2017] [Accepted: 01/29/2018] [Indexed: 11/19/2022]
Abstract
BRS-3 has an important role in glucose homeostasis. Its expression was reduced in skeletal muscle from obese and/or diabetic patients, and BRS-3 KO-mice developed obesity. In this work, focused on rat/human adipose tissue, BRS-3 gene-expression was lower than normal-levels in hyperlipidemic, type-2-diabetic (T2D), and type-1-diabetic rats and also in obese (OB) and T2D patients. Moreover, BRS-3 protein levels were decreased in diabetic rat and in obese and diabetic human fat pieces; but neither mutation nor even polymorphism in the BRS-3-gene was found in OB or T2D patients. Interestingly, in rat and human adipocytes, without metabolic alterations, [D-Tyr6,β-Ala11,Phe13,Nle14]bombesin6-14 -BRS-3-agonist-, as insulin, enhanced BRS-3 gene/protein expression, increased, PKB, p70s6K, MAPKs and p90RSK1 phosphorylation-levels, and induced a concentration-related stimulation of glucose transport, GLUT-4 membrane translocation and lipogenesis, exclusively mediated by BRS-3, and abolished by wortmannin, PD98059 or rapamacyn. These results confirm that BRS-3 and/or its agonist are a potential therapeutic tool for obesity/diabetes.
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Affiliation(s)
- Zaida Moreno-Villegas
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonio Martín-Duce
- Department of Nursery, Unit of Surgery, Universidad de Alcalá, Madrid, Spain
| | - César Aparicio
- Department of Vascular Surgery, Hospital Fundación Jiménez Díaz, Madrid, Spain
| | - Sergio Portal-Núñez
- Bone and Joint Research Unit, IIS-FJD, Madrid, Spain; Applied Molecular Medicine Institute, School of Medicine, Universidad San Pablo CEU, CEU Universities, Madrid, Spain
| | | | - Samuel A Mantey
- National Institutes of Health, Cell Biology Section, NIDDK, Digestive Disease Branch, Bethesda, MD, USA
| | - Robert T Jensen
- National Institutes of Health, Cell Biology Section, NIDDK, Digestive Disease Branch, Bethesda, MD, USA
| | - Oscar Lorenzo
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, Madrid, Spain; Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Jesús Egido
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, Madrid, Spain; Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Nieves González
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, Madrid, Spain; Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain.
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Ramos-Álvarez I, Moreno P, Mantey SA, Nakamura T, Nuche-Berenguer B, Moody TW, Coy DH, Jensen RT. Insights into bombesin receptors and ligands: Highlighting recent advances. Peptides 2015; 72:128-144. [PMID: 25976083 PMCID: PMC4641779 DOI: 10.1016/j.peptides.2015.04.026] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/29/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022]
Abstract
This following article is written for Prof. Abba Kastin's Festschrift, to add to the tribute to his important role in the advancement of the role of peptides in physiological, as well as pathophysiological processes. There have been many advances during the 35 years of his prominent role in the Peptide field, not only as editor of the journal Peptides, but also as a scientific investigator and editor of two volumes of the Handbook of Biological Active Peptides [146,147]. Similar to the advances with many different peptides, during this 35 year period, there have been much progress made in the understanding of the pharmacology, cell biology and the role of (bombesin) Bn receptors and their ligands in various disease states, since the original isolation of bombesin from skin of the European frog Bombina bombina in 1970 [76]. This paper will briefly review some of these advances over the time period of Prof. Kastin 35 years in the peptide field concentrating on the advances since 2007 when many of the results from earlier studies were summarized [128,129]. It is appropriate to do this because there have been 280 articles published in Peptides during this time on bombesin-related peptides and it accounts for almost 5% of all publications. Furthermore, 22 Bn publications we have been involved in have been published in either Peptides [14,39,55,58,81,92,93,119,152,216,225,226,231,280,302,309,355,361,362] or in Prof. Kastin's Handbook of Biological Active Peptides [137,138,331].
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Affiliation(s)
- Irene Ramos-Álvarez
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Paola Moreno
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Samuel A Mantey
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Taichi Nakamura
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Bernardo Nuche-Berenguer
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Terry W Moody
- Center for Cancer Research, Office of the Director, NCI, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - David H Coy
- Peptide Research Laboratory, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, United States
| | - Robert T Jensen
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States.
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González N, Moreno P, Jensen RT. Bombesin receptor subtype 3 as a potential target for obesity and diabetes. Expert Opin Ther Targets 2015; 19:1153-1170. [PMID: 26066663 PMCID: PMC5417335 DOI: 10.1517/14728222.2015.1056154] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Diabetes mellitus and obesity are important health issues; increasing in prevalence, both in the USA and globally. There are only limited pharmacological treatments, and although bariatric surgery is effective, new effective pharmacologic treatments would be of great value. This review covers one area of increasing interest that could yield new novel treatments of obesity/diabetes mellitus. It involves recognition of the central role the G-protein-coupled receptor, bombesin receptor subtype 3 (BRS-3) plays in energy/glucose metabolism. AREAS COVERED Since the initial observation that BRS-3 knockout mice develop obesity, hypertension, impaired glucose metabolism and hyperphagia, there have been numerous studies of the mechanisms involved and the development of selective BRS-3 agonists/antagonists, which have marked effects on body weight, feeding and glucose/insulin homeostasis. In this review, each of these areas is briefly reviewed. EXPERT OPINION BRS-3 plays an important role in glucose/energy homeostasis. The development of potent, selective BRS-3 agonists demonstrates promise as a novel approach to treat obesity/diabetic states. One important question that needs to be addressed is whether BRS-3 agonists need to be centrally acting. This is particularly important in light of recent animal and human studies that report transient cardiovascular side effects with centrally acting oral BRS agonists.
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Affiliation(s)
- Nieves González
- The Autonomous University of Madrid, IIS-Jiménez Díaz Foundation, Renal, Vascular and Diabetes Research Laboratory, Spanish Biomedical Research Network in Diabetes and, Associated Metabolic Disorders (CIBERDEM) , Madrid , Spain
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González N, Martín-Duce A, Martínez-Arrieta F, Moreno-Villegas Z, Portal-Núñez S, Sanz R, Egido J. Effect of bombesin receptor subtype-3 and its synthetic agonist on signaling, glucose transport and metabolism in myocytes from patients with obesity and type 2 diabetes. Int J Mol Med 2015; 35:925-31. [PMID: 25653074 PMCID: PMC4356436 DOI: 10.3892/ijmm.2015.2090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/15/2015] [Indexed: 11/17/2022] Open
Abstract
Bombesin receptor subtype-3 (BRS-3) is an orphan G-protein-coupled receptor (GPCR) member of the bombesin receptor family. Several studies have suggested an association between obesity, alterations in glucose metabolism, diabetes and the BRS-3 receptor. In this study, we focused on patients simultaneously diagnosed with obesity and type 2 diabetes (OB/T2D). The analysis of BRS-3 expression in the skeletal muscle of these patients revealed a marked decrease in the expression of BRS-3 at the mRNA (23.6±1.3-fold downregulation, p<0.0001) and protein level (49±7% decrease, p<0.05) compared to the normal patients (no obesity and diabetes). Moreover, in cultured primary myocytes from patients with OB/T2D, the synthetic BRS-3 agonist, [D-Try6,β-Ala11,Phe13,Nle14]bombesin6–14, significantly increased the phosphorylation levels of mitogen-activated protein kinase (MAPK), p90RSK1, protein kinase B (PKB) and p70s6K. Specifically, the ligand at 10−11 M induced the maximal phosphorylation of MAPKs (p42, 159±15% of the control; p44, 166±11% of the control; p<0.0001) and p90RSK1 (148±2% of the control, p<0.0001). The basal phosphorylation levels of all kinases were reduced (p<0.05) in the patients with OB/T2D compared to the normal patients. Furthermore, the BRS-3 agonist stimulated glucose transport, which was already detected at 10−12 M (133±9% of the control), reached maximal levels at 10−11 M (160±9%, p<0.0001) and was maintained at up to 10−8 M (overall mean, 153±7%; p<0.007). This effect was less promiment than that attained with 10−8 M insulin (202±9%, p=0.009). The effect of the agonist on glycogen synthase a activity achieved the maximum effect at 10−11 M (165±16% of the control; p<0.0001), which did not differ from that observed with higher concentrations of the agonist. These results suggest that muscle cells isolated from patients with OB/T2D have extremely high sensitivity to the synthetic ligand, and the effects are particularly observed on MAPK and p90RSK1 phosphorylation, as well as glucose uptake. Moreover, our data indicate that BRS-3 may prove to be useful as a potential therapeutic target for the treatment of patients with OB/T2D.
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Affiliation(s)
- Nieves González
- Renal, Vascular and Diabetes Research Laboratory, IIS-Jiménez Díaz Foundation, The Autonomous University of Madrid, Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | | | - Félix Martínez-Arrieta
- Department of General Surgery, Puerta de Hierro-Majadahonda University Hospital, The Autonomous University of Madrid, Madrid, Spain
| | - Zaida Moreno-Villegas
- Renal, Vascular and Diabetes Research Laboratory, IIS-Jiménez Díaz Foundation, The Autonomous University of Madrid, Madrid, Spain
| | - Sergio Portal-Núñez
- Department of Bone and Mineral Metabolism, IIS-Jiménez Díaz Foundation, Cooperative Research Thematic Network on Aging and Frailty (RETICEF), Madrid, Spain
| | - Raúl Sanz
- Department of Neurology, IIS-Jiménez Díaz Foundation, Madrid, Spain
| | - Jesús Egido
- Renal, Vascular and Diabetes Research Laboratory, IIS-Jiménez Díaz Foundation, The Autonomous University of Madrid, Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
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Santoro ML, Ota VK, Stilhano RS, Silva PN, Santos CM, Diana MC, Gadelha A, Bressan RA, Melaragno MI, Han SW, Abílio VC, Belangero SI. Effect of antipsychotic drugs on gene expression in the prefrontal cortex and nucleus accumbens in the spontaneously hypertensive rat (SHR). Schizophr Res 2014; 157:163-8. [PMID: 24893910 DOI: 10.1016/j.schres.2014.05.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 04/03/2014] [Accepted: 05/05/2014] [Indexed: 12/19/2022]
Abstract
Antipsychotic drugs (APDs) are the standard treatment for schizophrenia. The therapeutic effect of these drugs is dependent upon the dopaminergic D2 blockade, but they also modulate other neurotransmitter pathways. The exact mechanisms underlying the clinical response to APDs are not fully understood. In this study, we compared three groups of animals for the expression of 84 neurotransmitter genes in the prefrontal cortex (PFC) and nucleus accumbens (NAcc). Each group was treated with a different APD (risperidone, clozapine or haloperidol), and with a non-treated group of spontaneously hypertensive rats (SHRs), which is an animal model for schizophrenia. This study also explored whether or not differential expression was regulated by DNA methylation in the promoter region (PR). In the clozapine group, we found that Chrng was downregulated in the NAcc and six genes were downregulated in the PFC. In the haloperidol group, Brs3 and Glra1 were downregulated, as was Drd2 in the clozapine group and Drd3, Galr3 and Gabrr1 in the clozapine and haloperidol groups. We also encountered four hypermethylated CG sites in the Glra1 PR, as well as three in the risperidone group and another in the haloperidol group, when compared to non-treated rats. Following the APD treatment, the gene expression results revealed the involvement of genes that had not previously been described, in addition to the activity of established genes. The investigation of the involvement of these novel genes can lead to better understanding about the specific mechanisms of action of the individual APDs studied.
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Affiliation(s)
- Marcos Leite Santoro
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1° andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil
| | - Vanessa Kiyomi Ota
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1° andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil
| | - Roberta Sessa Stilhano
- Department of Biophysics and Investigation Center for Gene Therapy, Universidade Federal de Sao Paulo (UNIFESP), Rua Mirassol 207, CEP:04044-010, Brazil
| | - Patrícia Natália Silva
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1° andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil
| | - Camila Maurício Santos
- LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil; Department of Pharmacology, Universidade Federal de Sao Paulo (UNIFESP), Rua Pedro de Toledo 669, 5th floor, CEP: 04039032, Brazil
| | - Mariana Cepollaro Diana
- LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil; Department of Pharmacology, Universidade Federal de Sao Paulo (UNIFESP), Rua Pedro de Toledo 669, 5th floor, CEP: 04039032, Brazil
| | - Ary Gadelha
- LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil
| | - Rodrigo Affonseca Bressan
- LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil
| | - Maria Isabel Melaragno
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1° andar, CEP 04023-900 São Paulo, Brazil
| | - Sang Won Han
- Department of Biophysics and Investigation Center for Gene Therapy, Universidade Federal de Sao Paulo (UNIFESP), Rua Mirassol 207, CEP:04044-010, Brazil
| | - Vanessa Costhek Abílio
- LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil; Department of Pharmacology, Universidade Federal de Sao Paulo (UNIFESP), Rua Pedro de Toledo 669, 5th floor, CEP: 04039032, Brazil
| | - Sintia Iole Belangero
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1° andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Lab of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3° floor, CEP 05039-032 São Paulo, Brazil.
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Ramos-Álvarez I, Moreno-Villegas Z, Martín-Duce A, Sanz R, Aparicio C, Portal-Núñez S, Mantey SA, Jensen RT, González N. Human BRS-3 receptor: functions/role in cell signaling pathways and glucose metabolism in obese or diabetic myocytes. Peptides 2014; 51:91-99. [PMID: 24220502 DOI: 10.1016/j.peptides.2013.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/04/2013] [Accepted: 11/04/2013] [Indexed: 10/26/2022]
Abstract
Several studies showed that the orphan Bombesin Receptor Subtype-3 (BRS-3) - member of the bombesin receptor family - has an important role in glucose homeostasis (v.g.: BRS-3-KO mice developed mild obesity, and decreased levels of BRS-3 mRNA/protein have been described in muscle from obese (OB) and type 2 diabetic (T2D) patients). In this work, to gain insight into BRS-3 receptor cell signaling pathways, and its implication on glucose metabolism, primary cultured myocytes from normal subjects, OB or T2D patients were tested using high affinity ligand - [d-Tyr(6),β-Ala(11),Phe(13),Nle(14)]bombesin6-14. In muscle cells from all metabolic conditions, the compound significantly increased not only MAPKs, p90RSK1, PKB and p70s6K phosphorylation levels, but also PI3K activity; moreover, it produced a dose-response stimulation of glycogen synthase a activity and glycogen synthesis. Myocytes from OB and T2D patients were more sensitive to the ligand than normal, and T2D cells even more than obese myocytes. These results widen the knowledge of human BRS-3 cell signaling pathways induced by a BRS-3 agonist, described its insulin-mimetic effects on glucose metabolism, showed the role of BRS-3 receptor in glucose homeostasis, and also propose the employing of BRS-3/ligand system, as participant in the obese and diabetic therapies.
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MESH Headings
- Adult
- Aged
- Bombesin/pharmacology
- Cells, Cultured
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Female
- Glucose/metabolism
- Glycogen/biosynthesis
- Glycogen Synthase/metabolism
- Homeostasis
- Humans
- Male
- Middle Aged
- Mitogen-Activated Protein Kinases/metabolism
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Obesity/metabolism
- Obesity/pathology
- Peptide Fragments/pharmacology
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphorylation
- Protein Processing, Post-Translational
- Proto-Oncogene Proteins c-akt/metabolism
- Receptors, Bombesin/agonists
- Receptors, Bombesin/physiology
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- Ribosomal Protein S6 Kinases, 90-kDa/metabolism
- Signal Transduction
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Affiliation(s)
- I Ramos-Álvarez
- Department of Metabolism, Nutrition and Hormones, IIS-Fundación Jiménez Díaz, CIBERDEM, Madrid, Spain
| | - Z Moreno-Villegas
- Department of Metabolism, Nutrition and Hormones, IIS-Fundación Jiménez Díaz, CIBERDEM, Madrid, Spain
| | - A Martín-Duce
- Department of Nursery, Unit of Surgery, Universidad de Alcalá de Henares, Madrid, Spain
| | - R Sanz
- Department of Neurology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | - C Aparicio
- Department of Vascular Surgery, Fundación Jiménez Díaz, Madrid, Spain
| | - S Portal-Núñez
- Department of Bone Mineral Metabolism, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | - S A Mantey
- Digestive Diseases Branch, NIDDK, NIH, Bethesda, USA
| | - R T Jensen
- Digestive Diseases Branch, NIDDK, NIH, Bethesda, USA
| | - N González
- Department of Metabolism, Nutrition and Hormones, IIS-Fundación Jiménez Díaz, CIBERDEM, Madrid, Spain.
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11
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Moreno P, Mantey SA, Nuche-Berenguer B, Reitman ML, González N, Coy DH, Jensen RT. Comparative pharmacology of bombesin receptor subtype-3, nonpeptide agonist MK-5046, a universal peptide agonist, and peptide antagonist Bantag-1 for human bombesin receptors. J Pharmacol Exp Ther 2013; 347:100-116. [PMID: 23892571 PMCID: PMC3781414 DOI: 10.1124/jpet.113.206896] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 07/24/2013] [Indexed: 12/21/2022] Open
Abstract
Bombesin-receptor-subtype-3 (BRS-3) is an orphan G-protein-coupled receptor of the bombesin (Bn) family whose natural ligand is unknown and which does not bind any natural Bn-peptide with high affinity. It is present in the central nervous system, peripheral tissues, and tumors; however, its role in normal physiology/pathophysiology is largely unknown because of the lack of selective ligands. Recently, MK-5046 [(2S)-1,1,1-trifluoro-2-[4-(1H-pyrazol-1-yl)phenyl]-3-(4-{[1-(trifluoromethyl)cyclopropyl]methyl}-1H-imidazol-2-yl)propan-2-ol] and Bantag-1 [Boc-Phe-His-4-amino-5-cyclohexyl-2,4,5-trideoxypentonyl-Leu-(3-dimethylamino) benzylamide N-methylammonium trifluoroacetate], a nonpeptide agonist and a peptide antagonist, respectively, for BRS-3 have been described, but there have been limited studies on their pharmacology. We studied MK-5046 and Bantag-1 interactions with human Bn-receptors-human bombesin receptor subtype-3 (hBRS-3), gastrin-releasing peptide receptor (GRP-R), and neuromedin B receptor (NMB-R)-and compared them with the nonselective, peptide-agonist [d-Tyr6,βAla11,Phe13,Nle14]Bn-(6-14) (peptide #1). Receptor activation was detected by activation of phospholipase C (PLC), mitogen-activated protein kinase (MAPK), focal adhesion kinase (FAK), paxillin, and Akt. In hBRS-3 cells, the relative affinities were Bantag-1 (1.3 nM) > peptide #1 (2 nM) > MK-5046 (37-160 nM) > GRP, NMB (>10 μM), and the binding-dose-inhibition curves were broad (>4 logs), with Hill coefficients differing significantly from unity. Curve-fitting demonstrated high-affinity (MK-5046, Ki = 0.08 nM) and low-affinity (MK-5046, Ki = 11-29 nM) binding sites. For PLC activation in hBRS-3 cells, the relative potencies were MK-5046 (0.02 nM) > peptide #1 (6 nM) > GRP, NMB, Bantag-1 (>10 μM), and MK-5046 had a biphasic dose response, whereas peptide #1 was monophasic. Bantag-1 was a specific hBRS-3-antagonist. In hBRS-3 cells, MK-5046 was a full agonist for activation of MAPK, FAK, Akt, and paxillin; however, it was a partial agonist for phospholipase A2 (PLA2) activation. The kinetics of activation/duration of action for PLC/MAPK activation of MK-5046 and peptide #1 differed, with peptide #1 causing more rapid stimulation; however, MK-5046 had more prolonged activity. Our study finds that MK-5046 and Bantag-1 have high affinity/selectivity for hBRS-3. The nonpeptide MK-5046 and peptide #1 agonists differ markedly in their receptor coupling, ability to activate different signaling cascades, and kinetics/duration of action. These results show that their hBRS-3 receptor activation is not always concordant and could lead to markedly different cellular responses.
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Affiliation(s)
- Paola Moreno
- Digestive Diseases Branch (P.M., S.M., B.N.-B., R.T.J.) and Diabetes, Endocrinology, and Obesity Branch (M.L.R.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; Department of Metabolism, Nutrition and Hormones (N.G.), IIS-Fundación Jiménez Díaz, Madrid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain; and Peptide Research Laboratories, Department of Medicine, Tulane Health Sciences Center, New Orleans, Louisiana (D.H.C.)
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12
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Ramos-Álvarez I, Martín-Duce A, Moreno-Villegas Z, Sanz R, Aparicio C, Portal-Núñez S, Mantey SA, Jensen RT, González N. Bombesin receptor subtype-3 (BRS-3), a novel candidate as therapeutic molecular target in obesity and diabetes. Mol Cell Endocrinol 2013; 367:109-115. [PMID: 23291341 DOI: 10.1016/j.mce.2012.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 12/03/2012] [Accepted: 12/26/2012] [Indexed: 10/27/2022]
Abstract
BRS-3 KO-mice developed obesity and unbalanced glucose metabolism, suggesting an important role of BRS-3 receptor in glucose homeostasis. We explored BRS-3 expression in skeletal muscle from normal, obese or type-2 diabetic (T2D) patients, and the effect of [D-Phe(6), β-Ala(11),Phe(13),Nle(14)]bombesin(6-14)-BRS-3-agonist-peptide (BRS-3-AP) - on glucose-related effects, before or after BRS-3 gene silencing. In muscle tissue and primary cultured myocytes from altered metabolic states, BRS-3 gene/protein expressions were down-regulated. In normal, obese and T2D cells: A) BRS-3-AP as insulin enhanced BRS-3 and GLUT-4 mRNA/protein levels; improving glucotransporter translocation to plasma membrane, and B) BRS-3-AP caused a concentration-related-stimulation of glucose transport, being obese and T2D myocytes more sensitive to the ligand than normal. Wortmannin and PD98059, but not rapamycin, abolished the stimulatory action of BRS-3-AP on glucose transport. BRS-3 plays an important role in glucose metabolism, and could be use as a molecular target, and/or its ligand, as a therapeutic agent for obesity and diabetes treatments.
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Affiliation(s)
- Irene Ramos-Álvarez
- Department of Metabolism, Nutrition and Hormones, IIS-Fundación Jiménez Díaz, Madrid, Spain
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13
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Abstract
PURPOSE OF REVIEW This review summarizes the results of recent studies regarding the biology and pharmacology of novel synthetic agonists and antagonists of the bombesin receptor subtype-3 (BRS-3). RECENT FINDINGS All three mammalian bombesin receptors including gastrin-releasing peptide receptor, the neuromedin B receptor, and the BRS-3 have been shown to regulate energy balance and appetite and satiety. Studies indicate that the orphan BRS-3 is an important regulator of body weight, energy expenditure, and glucose homeostasis. Endogenous bombesin-like peptides bombesin, gastrin-releasing peptide, and neuromedin B receptor do not bind to BRS-3 and the endogenous BRS-3 ligand remains unknown. The novel synthesis of selective, high-affinity BRS-3 agonists and antagonists has recently been accomplished and showed that BRS-3 regulates energy balance independent of other established pathways and glucose-stimulated insulin secretion in the pancreatic islet cells. The availability of new BRS-3 selective agonists and antagonists will facilitate further elucidation of its role in energy homeostasis, and provides a potential approach for the pharmacological treatment of obesity and type 2 diabetes. SUMMARY The native ligand of the G protein-coupled BRS-3 has not been identified as of now. However, novel synthesis of small-molecule, high-affinity agonists and antagonists on the BRS-3 was used in the recent studies and demonstrated an important role of BRS-3 in the regulation of energy homeostasis and glucose metabolism.
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Affiliation(s)
- Ishita D Majumdar
- Section of Gastroenterology, Boston University School of Medicine, Boston, Massachusetts, USA
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14
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Abstract
Studies on bombesin-like peptides (BLP) and their respective mammalian receptors (Bn-r) have demonstrated a significant biological impact on a broad array of physiological and pathophysiological conditions. Pharmacological experiments in vitro and in vivo as well as utilization of genetic rodent models of the gastrin-releasing peptide receptor (GRP-R/BB2-receptor), neuromedin B receptor (NMB-R/BB1-receptor), and the bombesin receptor subtype-3 (BRS-3/BB3-receptor) further delineated their role in health and disease. All three mammalian bombesin receptors have been shown to possess some role in the regulation of energy balance and appetite and satiety. Compelling experimental evidence has accumulated indicating that the orphan BRS-3 is an important regulator of body weight, energy expenditure, and glucose homeostasis. BRS-3 possesses no high affinity to the endogenous bombesin-like peptides (BLP) bombesin, GRP, and NMB, and its endogenous ligand remains unknown. Recently, the synthesis of novel, selective high-affinity BRS-3 agonists and antagonists has been accomplished and has demonstrated that BRS-3 regulates energy balance independent of other established pathways. Accordingly, the availability of new BRS-3 selective agonists and antagonists will facilitate further elucidation of its role in energy homeostasis and provides a potential approach for the pharmacological treatment of obesity.
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15
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Qin X, Qu X, Coy D, Weber HC. A Selective Human Bombesin Receptor Subtype-3 Peptide Agonist Mediates CREB Phosphorylation and Transactivation. J Mol Neurosci 2011; 46:88-99. [DOI: 10.1007/s12031-011-9675-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 11/07/2011] [Indexed: 01/08/2023]
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16
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Feng Y, Guan XM, Li J, Metzger JM, Zhu Y, Juhl K, Zhang BB, Thornberry NA, Reitman ML, Zhou YP. Bombesin receptor subtype-3 (BRS-3) regulates glucose-stimulated insulin secretion in pancreatic islets across multiple species. Endocrinology 2011; 152:4106-15. [PMID: 21878513 DOI: 10.1210/en.2011-1440] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bombesin receptor subtype-3 (BRS-3) regulates energy homeostasis, and BRS-3 agonism is being explored as a possible therapy for obesity. Here we study the role of BRS-3 in the regulation of glucose-stimulated insulin secretion (GSIS) and glucose homeostasis. We quantified BRS-3 mRNA in pancreatic islets from multiple species and examined the acute effects of Bag-1, a selective BRS-3 agonist, on GSIS in mouse, rat, and human islets, and on oral glucose tolerance in mice. BRS-3 is highly expressed in human, mouse, rhesus, and dog (but not rat) pancreatic islets and in rodent insulinoma cell lines (INS-1 832/3 and MIN6). Silencing BRS-3 with small interfering RNA or pharmacological blockade with a BRS-3 antagonist, Bantag-1, reduced GSIS in 832/3 cells. In contrast, the BRS-3 agonist (Bag-1) increased GSIS in 832/3 and MIN6 cells. The augmentation of GSIS by Bag-1 was completely blocked by U73122, a phospholipase C inhibitor. Bag-1 also enhanced GSIS in islets isolated from wild-type, but not Brs3 knockout mice. In vivo, Bag-1 reduced glucose levels during oral glucose tolerance test in a BRS-3-dependent manner. BRS-3 agonists also increased GSIS in human islets. These results identify a potential role for BRS-3 in islet physiology, with agonism directly promoting GSIS. Thus, in addition to its potential role in the treatment of obesity, BRS-3 may also regulate blood glucose levels and have a role in the treatment of diabetes mellitus.
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Affiliation(s)
- Yue Feng
- Department of Diabetes and Obesity, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Sancho V, Moody TW, Mantey SA, Di Florio A, Uehara H, Coy DH, Jensen RT. Pharmacology of putative selective hBRS-3 receptor agonists for human bombesin receptors (BnR): affinities, potencies and selectivity in multiple native and BnR transfected cells. Peptides 2010; 31:1569-1578. [PMID: 20438784 PMCID: PMC2905478 DOI: 10.1016/j.peptides.2010.04.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 04/23/2010] [Accepted: 04/23/2010] [Indexed: 11/28/2022]
Abstract
The orphan receptor, bombesin receptor subtype-3(BRS-3) is a G-protein-coupled receptor classified in the bombesin (Bn) receptor family because of its high homology (47-51%) with other members of this family [gastrin-releasing peptide receptor [GRPR] and neuromedin B receptor [NMBR]]. There is increasing interest in BRS-3, because primarily from receptor knockout studies, it seems important in energy metabolism, glucose control, insulin secretion, motility and tumor growth. Pharmacological tools to study the role of BRS-3 in physiology/pathophysiology are limited because the natural ligand is unknown and BRS-3 has low affinity for all naturally occurring Bn-related peptides. However, a few years ago a synthetic high-affinity agonist [dTyr(6),betaAla(11),Phe(13),Nle(14)]Bn-(6-14) was described but was nonselective for BRS-3 over other Bn receptors. Based on this peptide, in various studies a number of putative selective, high-potency hBRS-3 agonists were described, however the results on their selectivity are conflicting in a number of cases. The purpose of the present study was to thoroughly study the pharmacology of four of the most select/potent putative hBRS-3 agonists (#2-4, 16a). Each was studied in multiple well-characterized Bn receptor-transfected cells and native Bn receptor bearing cells, using binding studies, alterations in cellular signaling (PLC, PKD) and changes in cellular function(growth). Two peptides (#2, #3) had nM affinities/potencies for hBRS-3, peptide #4 had low affinity/potency, and peptide #16a very low (>3000 nM). Peptide#3 had the highest selectivity for hBRS-3 (100-fold), whereas #2, 4 had lower selectivity. Peptide #16a's selectivity could not be determined because of its low affinity/potencies for all hBn receptors. These results show that peptide #3 is the preferred hBRS-3 agonist for studies at present, although its selectivity of only 100-fold may limit its utility in some cases. This study underscores the importance of full pharmacological characterization of newly reported selective agonists.
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Affiliation(s)
- Veronica Sancho
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Terry W. Moody
- NCI Office of the Director, CCR, NCI and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Samuel A. Mantey
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Alessia Di Florio
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Hirotsugu Uehara
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - David H. Coy
- Peptide Research Laboratories, Department of Medicine, Tulane Health Sciences Center, New Orleans, Louisiana 70112-2699
| | - Robert T. Jensen
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
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Gbahou F, Holst B, Schwartz TW. Molecular basis for agonism in the BB3 receptor: an epitope located on the interface of transmembrane-III, -VI, and -VII. J Pharmacol Exp Ther 2010; 333:51-9. [PMID: 20065020 DOI: 10.1124/jpet.109.162131] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2025] Open
Abstract
Epitopes determining the agonist property of two structurally distinct selective ligands for the human bombesin receptor subtype 3 (BB3), [D-Tyr6,(R)-Apa11,Phe13, Nle14]-bombesin(6-14) (Pep-1) and Ac-Phe-Trp-Ala-His(TauBzl)-Nip-Gly-Arg-NH2 (Pep-2), were mapped through systematic mutagenesis of the main ligand-binding pocket of the receptor. The mutational map for the smaller Pep-2 spanned the entire binding pocket of the BB3 receptor. In contrast, the much fewer mutational hits for the larger Pep-1 were confined to the center of the pocket, i.e., the opposing faces of the extracellular segments of transmembrane (TM)-III, TM-VI, and TM-VII. All the residues, which upon mutation affected Pep-1, were also hits for Pep-2 and included those that were most essential for the function of Pep-2: LeuIII:04 (Leu(123)), TyrVI:16 (Tyr(291)), and ArgVII:06 (Arg(316)). The BB3 receptor was found to signal with 12% ligand-independent activity that was strongly influenced both positively and negatively by several mutations in the binding pocket. The substitutions, which decreased the constitutive signaling, included not only the major mutational hits for the peptide agonists but also mutations more superficially located in the receptor. It is concluded that activation of the BB3 receptor is dependent upon an epitope in the main ligand-binding pocket at the interface between TM-III, TM-VI, and TM-VII that corresponds to the site where, for example, activating metal ion sites have been constructed previously in 7TM receptors.
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Affiliation(s)
- F Gbahou
- Institut National de la Santé et de la Recherche Médicale U894, Centre de Psychiatrie et Neurosciences, Equipe de Neurobiologie et Pharmacologie Moléculaire, 2 Ter Rue d'Alésia, 75014 Paris, France.
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19
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Regulation of energy homeostasis by bombesin receptor subtype-3: selective receptor agonists for the treatment of obesity. Cell Metab 2010; 11:101-12. [PMID: 20096642 DOI: 10.1016/j.cmet.2009.12.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Revised: 09/02/2009] [Accepted: 12/18/2009] [Indexed: 01/04/2023]
Abstract
Bombesin receptor subtype 3 (BRS-3) is a G protein coupled receptor whose natural ligand is unknown. We developed potent, selective agonist (Bag-1, Bag-2) and antagonist (Bantag-1) ligands to explore BRS-3 function. BRS-3-binding sites were identified in the hypothalamus, caudal brainstem, and several midbrain nuclei that harbor monoaminergic cell bodies. Antagonist administration increased food intake and body weight, whereas agonists increased metabolic rate and reduced food intake and body weight. Prolonged high levels of receptor occupancy increased weight loss, suggesting a lack of tachyphylaxis. BRS-3 agonist effectiveness was absent in Brs3(-/Y) (BRS-3 null) mice but was maintained in Npy(-/-)Agrp(-/-), Mc4r(-/-), Cnr1(-/-), and Lepr(db/db) mice. In addition, Brs3(-/Y) mice lost weight upon treatment with either a MC4R agonist or a CB1R inverse agonist. These results demonstrate that BRS-3 has a role in energy homeostasis that complements several well-known pathways and that BRS-3 agonists represent a potential approach to the treatment of obesity.
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Abstract
PURPOSE OF REVIEW This review will highlight recent advances in the understanding of molecular mechanisms by which mammalian bombesin receptors are regulated and which intracellular signaling pathways have been characterized to mediate agonist-dependent receptor biological effects. RECENT FINDINGS Mammalian bombesin receptors have been demonstrated to be involved in a larger array of physiological and pathophysiological conditions than previously reported. Pharmacological experiments in vitro and in vivo as well as utilization of animals genetically deficient of the gastrin-releasing peptide receptor demonstrated roles in memory and fear behavior, lung development and injury, small intestinal cell repair, autocrine tumor growth, and mediating signals for pruritus and penile reflexes. Intracellular signaling studies predominantly of the gastrin-releasing peptide receptor owing to its frequent overexpression in some human malignancies showed that PI3 kinase activation is an important mechanism of cell proliferation. Tumor cell treatment including gastrin-releasing peptide receptor antagonists combined with inhibition of epidermal growth factor receptor resulted in an additive effect on blocking cell proliferation. Novel molecular mechanisms of the orphan bombesin receptor subtype-3 and gastrin-releasing peptide receptor gene regulation have been elucidated. SUMMARY Inhibition of gastrin-releasing peptide receptor signaling in human malignancies represents an attractive target for pharmacological treatment. Novel functions of bombesin related peptides have been identified including processes in the central nervous system, lung and intestinal tract.
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Affiliation(s)
- H Christian Weber
- Boston University School of Medicine, Section of Gastroenterology, Boston, MA 02118, USA.
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21
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Discovery of small molecule agonists for the bombesin receptor subtype 3 (BRS-3) based on an omeprazole lead. Bioorg Med Chem Lett 2008; 18:5451-5. [DOI: 10.1016/j.bmcl.2008.09.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 09/05/2008] [Accepted: 09/08/2008] [Indexed: 11/23/2022]
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22
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Jensen RT, Battey JF, Spindel ER, Benya RV. International Union of Pharmacology. LXVIII. Mammalian bombesin receptors: nomenclature, distribution, pharmacology, signaling, and functions in normal and disease states. Pharmacol Rev 2008; 60:1-42. [PMID: 18055507 PMCID: PMC2517428 DOI: 10.1124/pr.107.07108] [Citation(s) in RCA: 395] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The mammalian bombesin receptor family comprises three G protein-coupled heptahelical receptors: the neuromedin B (NMB) receptor (BB(1)), the gastrin-releasing peptide (GRP) receptor (BB(2)), and the orphan receptor bombesin receptor subtype 3 (BRS-3) (BB(3)). Each receptor is widely distributed, especially in the gastrointestinal (GI) tract and central nervous system (CNS), and the receptors have a large range of effects in both normal physiology and pathophysiological conditions. The mammalian bombesin peptides, GRP and NMB, demonstrate a broad spectrum of pharmacological/biological responses. GRP stimulates smooth muscle contraction and GI motility, release of numerous GI hormones/neurotransmitters, and secretion and/or hormone release from the pancreas, stomach, colon, and numerous endocrine organs and has potent effects on immune cells, potent growth effects on both normal tissues and tumors, potent CNS effects, including regulation of circadian rhythm, thermoregulation; anxiety/fear responses, food intake, and numerous CNS effects on the GI tract as well as the spinal transmission of chronic pruritus. NMB causes contraction of smooth muscle, has growth effects in various tissues, has CNS effects, including effects on feeding and thermoregulation, regulates thyroid-stimulating hormone release, stimulates various CNS neurons, has behavioral effects, and has effects on spinal sensory transmission. GRP, and to a lesser extent NMB, affects growth and/or differentiation of various human tumors, including colon, prostate, lung, and some gynecologic cancers. Knockout studies show that BB(3) has important effects in energy balance, glucose homeostasis, control of body weight, lung development and response to injury, tumor growth, and perhaps GI motility. This review summarizes advances in our understanding of the biology/pharmacology of these receptors, including their classification, structure, pharmacology, physiology, and role in pathophysiological conditions.
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Affiliation(s)
- R T Jensen
- Digestive Diseases Branch, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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Gonzalez N, Moody TW, Igarashi H, Ito T, Jensen RT. Bombesin-related peptides and their receptors: recent advances in their role in physiology and disease states. Curr Opin Endocrinol Diabetes Obes 2008; 15:58-64. [PMID: 18185064 PMCID: PMC2631407 DOI: 10.1097/med.0b013e3282f3709b] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Mammalian bombesin-related peptides, gastrin-releasing peptide and neuromedin B actions are mediated by two receptors (BB1-receptor, BB2-receptor), which are closely related to the orphan receptor BRS-3 (BB3-receptor). The purpose of this review is to highlight advances in the understanding of these peptides in physiology/disease states. RECENT FINDINGS Pharmacologic/receptor-knockout studies show involvement of these receptors in a number of new processes/diseases. Neuromedin B/BB1-receptor is an important physiological regulator of pituitary-thyroid function; in mediating behavior, especially feas/anxiety; in mediating satiety through different cascades than gastrin-releasing peptide/BB2 receptors and for its autocrine tumor-growth effects. Gastrin-releasing peptide/BB2-receptor plays important roles in mediating signals for pruritus, lung development/injury, small intestinal mucosal defense, and central nervous system processes such as learning/memory. The signaling mechanisms of its potent growth effects are being elucidated and their possible therapeutic targets identified. BB3-receptor knockout mice provided insights for their obesity/glucose intolerance and demonstrated that this receptor may be important in the lung response to injury, tumor growth and gastrointestinal motility. Each receptor is frequently overexpressed in human tumors and has potent growth effects. This effect is being explored to develop new antitumor treatments, such as bombesin-receptor ligands conjugated to cytotoxic agents. SUMMARY This receptor family is involved in an increasing number of central nervous system/peripheral processes physiologically and in disease states, and increased understanding of its role may lead to novel treatments.
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Affiliation(s)
- Nieves Gonzalez
- Digestive Diseases Branch, National Institutes of Health, Bethesda, Maryland 20892, USA
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Gonzalez N, Hocart SJ, Portal-Nuñez S, Mantey SA, Nakagawa T, Zudaire E, Coy DH, Jensen RT. Molecular basis for agonist selectivity and activation of the orphan bombesin receptor subtype 3 receptor. J Pharmacol Exp Ther 2008; 324:463-474. [PMID: 18006692 PMCID: PMC2593135 DOI: 10.1124/jpet.107.132332] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bombesin receptor subtype (BRS)-3, a G-protein-coupled orphan receptor, shares 51% identity with the mammalian bombesin (Bn) receptor for gastrin-releasing peptide. There is increasing interest in BRS-3 because it is important in energy metabolism, glucose control, motility, and tumor growth. BRS-3 has low affinity for all Bn-related peptides; however, recently synthetic high-affinity agonists, [d-Tyr(6)/d-Phe(6),betaAla(11),Phe(13),Nle(14)]Bn-(6-14), were described, but they are nonselective for BRS-3 over other Bn receptors. Based on these peptides, three BRS-3-selective ligands were developed: peptide 2, [d-Tyr(6)(R)-3-amino-propionic acid(11),Phe(13),Nle(14)]Bn(6-14); peptide 3, [d-Tyr(6),(R)-Apa(11),4Cl-Phe(13),Nle(14)]Bn(6-14); and peptide 4, acetyl-Phe-Trp-Ala-His-(tBzl)-piperidine-3 carboxylic acid-Gly-Arg-NH(2). Their molecular determinants of selectivity/high affinity for BRS-3 are unknown. To address this, we used a chimeric/site mutagenesis approach. Substitution of extracellular domain 2 (EC2) of BRS-3 by the comparable gastrin-releasing peptide receptor (GRPR) domain decreased 26-, 4-, and 0-fold affinity for peptides 4, 3, and 2. Substitution of EC3 decreased affinity 4-, 11-, and 0-fold affinity for peptides 2 to 4. Ten-point mutations in the EC2 and adjacent transmembrane regions (TM2) 2 and 3 of BRS-3 were made. His107 (EC2-BRS-3) for lysine (H107K) (EC2-GRPR) decreased affinity (25- and 0-fold) for peptides 4 and 1; however, it could not be activated by either peptide. Its combination with Val101 (TM2), Gly112 (EC2), and Arg127 (TM3) resulted in complete loss-of-affinity of peptide 4. Receptor-modeling showed that each of these residues face inward and are within 4 A of the binding pocket. These results demonstrate that Val101, His107, Gly112, and Arg127 in the EC2/adjacent upper TMs of BRS-3 are critical for the high BRS3 selectivity of peptide 4. His107 in EC2 is essential for BRS-3 activation, suggesting amino-aromatic ligand/receptor interactions with peptide 4 are critical for both binding and activation. Furthermore, these result demonstrate that even though these three BRS-3-selective agonists were developed from the same template peptide, [d-Phe(6),betaAla(11),Phe(13),Nle(14)]Bn-(6-14), their molecular determinants of selectivity/high affinity varied considerably.
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Affiliation(s)
- Nieves Gonzalez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Heath, Building 10, Room 9C-103, 10 Center Dr. MSC 1804, Bethesda, MD 20892-1804, USA
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