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Vafaei Z, Khodagholi F, Nategh M, Nikseresht S, Hashemirad SR, Raise-Abdullahi P, Vafaei AA, Motamedi F. Involvement of relaxin-family peptide-3 receptor (RXFP3) in the ventral dentate gyrus of the hippocampus in spatial and fear memory in rats. Peptides 2024; 178:171244. [PMID: 38788901 DOI: 10.1016/j.peptides.2024.171244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 05/21/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024]
Abstract
The neuropeptide relaxin-3 and its cognate receptor, relaxin family peptide-3 receptors (RXFP3), have been implicated in modulating learning and memory processes, but their specific roles remain unclear. This study utilized behavioral and molecular approaches to investigate the effects of putatively reversible blockade of RXFP3 in the ventral dentate gyrus (vDG) of the hippocampus on spatial and fear memory formation in rats. Male Wistar rats received bilateral vDG cannula implantation and injections of the RXFP3 antagonist, R3(BΔ23-27)R/I5 (400 ng/0.5 μL per side), or vehicle at specific time points before acquisition, consolidation, or retrieval phases of the Morris water maze and passive avoidance learning tasks. RXFP3 inhibition impaired acquisition in the passive avoidance task but not the spatial learning task. However, both memory consolidation and retrieval were disrupted in both tasks following RXFP3 antagonism. Ventral hippocampal levels of the consolidation-related kinase p70-S6 kinase (p70S6K) were reduced RXFP3 blockade. These findings highlight a key role for ventral hippocampal RXFP3 signaling in the acquisition, consolidation, and retrieval of spatial and emotional memories, extending previous work implicating this neuropeptide system in hippocampal memory processing.
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Affiliation(s)
- Zohreh Vafaei
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology Research Center, Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fariba Khodagholi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohsen Nategh
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Sara Nikseresht
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Pharmacology and Therapeutics, the University of Melbourne, Parkville, Victoria, Australia
| | - Seyed Reza Hashemirad
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Abbas Ali Vafaei
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran.
| | - Fereshteh Motamedi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology Research Center, Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Jayakody T, Inoue A, Kannan S, Nakamura G, Kawakami K, Mendis K, Nguyen TB, Li J, Herr DR, Verma CS, Dawe GS. Mechanisms of biased agonism by Gα i/o-biased stapled peptide agonists of the relaxin-3 receptor. Sci Signal 2024; 17:eabl5880. [PMID: 38349968 DOI: 10.1126/scisignal.abl5880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 01/26/2024] [Indexed: 02/15/2024]
Abstract
The neuropeptide relaxin-3 is composed of an A chain and a B chain held together by disulfide bonds, and it modulates functions such as anxiety and food intake by binding to and activating its cognate receptor RXFP3, mainly through the B chain. Biased ligands of RXFP3 would help to determine the molecular mechanisms underlying the activation of G proteins and β-arrestins downstream of RXFP3 that lead to such diverse functions. We showed that the i, i+4 stapled relaxin-3 B chains, 14s18 and d(1-7)14s18, were Gαi/o-biased agonists of RXFP3. These peptides did not induce recruitment of β-arrestin1/2 to RXFP3 by GPCR kinases (GRKs), in contrast to relaxin-3, which enabled the GRK2/3-mediated recruitment of β-arrestin1/2 to RXFP3. Relaxin-3 and the previously reported peptide 4 (an i, i+4 stapled relaxin-3 B chain) did not exhibit biased signaling. The staple linker of peptide 4 and parts of both the A chain and B chain of relaxin-3 interacted with extracellular loop 3 (ECL3) of RXFP3, moving it away from the binding pocket, suggesting that unbiased ligands promote a more open conformation of RXFP3. These findings highlight roles for the A chain and the N-terminal residues of the B chain of relaxin-3 in inducing conformational changes in RXFP3, which will help in designing selective biased ligands with improved therapeutic efficacy.
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Affiliation(s)
- Tharindunee Jayakody
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore
- Department of Chemistry, University of Colombo, P.O. Box 1490, Colombo 00300, Sri Lanka
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | | | - Gaku Nakamura
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Krishan Mendis
- Department of Chemistry, University of Colombo, P.O. Box 1490, Colombo 00300, Sri Lanka
| | - Thanh-Binh Nguyen
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671
| | - Jianguo Li
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671
| | - Deron R Herr
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Chandra S Verma
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671
- Department of Biological Sciences, National University of Singapore, 6 Science Drive 4, Singapore 117558
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr., Singapore 637551
| | - Gavin S Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Precision Medicine Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Rahman MT, Chaminda Lakmal HH, Hussain J, Jin C. Targeting the relaxin-3/RXFP3 system: a patent review for the last two decades. Expert Opin Ther Pat 2024; 34:71-81. [PMID: 38573177 PMCID: PMC11027024 DOI: 10.1080/13543776.2024.2338099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/15/2024] [Indexed: 04/05/2024]
Abstract
INTRODUCTION The neuropeptide relaxin-3/RXFP3 system belongs to the relaxin/insulin superfamily and is involved in many important physiological processes, such as stress responses, appetite control, and motivation for reward. Although relaxin-3 is the endogenous agonist for RXFP3, it can also bind to and activate RXFP1 and RXFP4. Consequently, research has been focused on the development of RXFP3-specific peptides and small-molecule ligands to validate the relaxin-3/RXFP3 system as a novel drug target. AREAS COVERED This review provides an overview of patents on the relaxin-3/RXFP3 system covering ligand development and pharmacological studies since 2003. Related patents and literature reports were obtained from established sources including SciFinder, Google Patents, and Espacenet for patents and SciFinder, PubMed, and Google Scholar for literature reports. EXPERT OPINION There has been an increasing amount of patent activities around relaxin-3/RXFP3, highlighting the importance of this novel neuropeptide system for drug discovery. The development of relaxin-3 derived peptides and small-molecule modulators, as well as behavioral studies in rodents, have shown that the relaxin-3/RXFP3 system is a promising drug target for treating various metabolic and neuropsychiatric diseases including obesity, anxiety, and alcohol addiction.
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Affiliation(s)
- Md Toufiqur Rahman
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, USA
| | | | - Javeena Hussain
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, USA
| | - Chunyang Jin
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, USA
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Chen D, Rehfeld JF, Watts AG, Rorsman P, Gundlach AL. History of key regulatory peptide systems and perspectives for future research. J Neuroendocrinol 2023; 35:e13251. [PMID: 37053148 DOI: 10.1111/jne.13251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/10/2023] [Accepted: 02/26/2023] [Indexed: 03/06/2023]
Abstract
Throughout the 20th Century, regulatory peptide discovery advanced from the identification of gut hormones to the extraction and characterization of hypothalamic hypophysiotropic factors, and to the isolation and cloning of multiple brain neuropeptides. These discoveries were followed by the discovery of G-protein-coupled and other membrane receptors for these peptides. Subsequently, the systems physiology associated with some of these multiple regulatory peptides and receptors has been comprehensively elucidated and has led to improved therapeutics and diagnostics and their approval by the US Food and Drug Administration. In light of this wealth of information and further potential, it is truly a time of renaissance for regulatory peptides. In this perspective, we review what we have learned from the pioneers in exemplified fields of gut peptides, such as cholecystokinin, enterochromaffin-like-cell peptides, and glucagon, from the trailblazing studies on the key stress hormone, corticotropin-releasing factor, as well as from more recently characterized relaxin-family peptides and receptors. The historical viewpoints are based on our understanding of these topics in light of the earliest phases of research and on subsequent studies and the evolution of knowledge, aiming to sharpen our vision of the current state-of-the-art and those studies that should be prioritized in the future.
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Affiliation(s)
- Duan Chen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Alan G Watts
- Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
- Florey Department of Neuroscience and Mental Health and Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
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Chen Y, Zhou Q, Wang J, Xu Y, Wang Y, Yan J, Wang Y, Zhu Q, Zhao F, Li C, Chen CW, Cai X, Bathgate RAD, Shen C, Eric Xu H, Yang D, Liu H, Wang MW. Ligand recognition mechanism of the human relaxin family peptide receptor 4 (RXFP4). Nat Commun 2023; 14:492. [PMID: 36717591 PMCID: PMC9886975 DOI: 10.1038/s41467-023-36182-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/19/2023] [Indexed: 02/01/2023] Open
Abstract
Members of the insulin superfamily regulate pleiotropic biological processes through two types of target-specific but structurally conserved peptides, insulin/insulin-like growth factors and relaxin/insulin-like peptides. The latter bind to the human relaxin family peptide receptors (RXFPs). Here, we report three cryo-electron microscopy structures of RXFP4-Gi protein complexes in the presence of the endogenous ligand insulin-like peptide 5 (INSL5) or one of the two small molecule agonists, compound 4 and DC591053. The B chain of INSL5 adopts a single α-helix that penetrates into the orthosteric pocket, while the A chain sits above the orthosteric pocket, revealing a peptide-binding mode previously unknown. Together with mutagenesis and functional analyses, the key determinants responsible for the peptidomimetic agonism and subtype selectivity were identified. Our findings not only provide insights into ligand recognition and subtype selectivity among class A G protein-coupled receptors, but also expand the knowledge of signaling mechanisms in the insulin superfamily.
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Affiliation(s)
- Yan Chen
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Qingtong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Jiang Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,Lingang Laboratory, Shanghai, 200031, China.,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China
| | - Youwei Xu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yun Wang
- Genova Biotech (Changzhou) Co., Ltd, Changzhou, 213125, China
| | - Jiahui Yan
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yibing Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Qi Zhu
- Genova Biotech (Changzhou) Co., Ltd, Changzhou, 213125, China
| | - Fenghui Zhao
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Chenghao Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China
| | - Chuan-Wei Chen
- Research Center for Deepsea Bioresources, Sanya, Hainan, 572025, China
| | - Xiaoqing Cai
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ross A D Bathgate
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, 3052, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Chun Shen
- Genova Biotech (Changzhou) Co., Ltd, Changzhou, 213125, China
| | - H Eric Xu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Dehua Yang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Research Center for Deepsea Bioresources, Sanya, Hainan, 572025, China.
| | - Hong Liu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Ming-Wei Wang
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China. .,The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Research Center for Deepsea Bioresources, Sanya, Hainan, 572025, China. .,Department of Chemistry, School of Science, The University of Tokyo, Tokyo, 113-0033, Japan.
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Lewis JE, Woodward OR, Nuzzaci D, Smith CA, Adriaenssens AE, Billing L, Brighton C, Phillips BU, Tadross JA, Kinston SJ, Ciabatti E, Göttgens B, Tripodi M, Hornigold D, Baker D, Gribble FM, Reimann F. Relaxin/insulin-like family peptide receptor 4 (Rxfp4) expressing hypothalamic neurons modulate food intake and preference in mice. Mol Metab 2022; 66:101604. [PMID: 36184065 PMCID: PMC9579047 DOI: 10.1016/j.molmet.2022.101604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/08/2022] [Accepted: 09/16/2022] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE Insulin-like peptide 5 (INSL5) signalling, through its cognate receptor relaxin/insulin-like family peptide receptor 4 (RXFP4), has been reported to be orexigenic, and the high fat diet (HFD) preference observed in wildtype mice is altered in Rxfp4 knock-out mice. In this study, we used a new Rxfp4-Cre mouse model to investigate the mechanisms underlying these observations. METHODS We generated transgenic Rxfp4-Cre mice and investigated central expression of Rxfp4 by RT-qPCR, RNAscope and intraparenchymal infusion of INSL5. Rxfp4-expressing cells were chemogenetically manipulated in global Cre-reporter mice using designer receptors exclusively activated by designer drugs (DREADDs) or after stereotactic injection of a Cre-dependent AAV-DIO-Dq-DREADD targeting a population located in the ventromedial hypothalamus (RXFP4VMH). Food intake and feeding motivation were assessed in the presence and absence of a DREADD agonist. Rxfp4-expressing cells in the hypothalamus were characterised by single-cell RNA-sequencing (scRNAseq) and the connectivity of RXFP4VMH cells was investigated using viral tracing. RESULTS Rxfp4-Cre mice displayed Cre-reporter expression in the hypothalamus. Active expression of Rxfp4 in the adult mouse brain was confirmed by RT-qPCR and RNAscope. Functional receptor expression was supported by cyclic AMP-responses to INSL5 application in ex vivo brain slices and increased HFD and highly palatable liquid meal (HPM), but not chow, intake after intra-VMH INSL5 infusion. scRNAseq of hypothalamic RXFP4 neurons defined a cluster expressing VMH markers, alongside known appetite-modulating neuropeptide receptors (Mc4r, Cckar and Nmur2). Viral tracing demonstrated RXFP4VMH neural projections to nuclei implicated in hedonic feeding behaviour. Whole body chemogenetic inhibition (Di-DREADD) of Rxfp4-expressing cells, mimicking physiological INSL5-RXFP4 Gi-signalling, increased intake of the HFD and HPM, but not chow, whilst activation (Dq-DREADD), either at whole body level or specifically within the VMH, reduced HFD and HPM intake and motivation to work for the HPM. CONCLUSION These findings identify RXFP4VMH neurons as regulators of food intake and preference, and hypothalamic RXFP4 signalling as a target for feeding behaviour manipulation.
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Affiliation(s)
- Jo E Lewis
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
| | - Orla Rm Woodward
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Danaé Nuzzaci
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Christopher A Smith
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Alice E Adriaenssens
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Lawrence Billing
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Cheryl Brighton
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Benjamin U Phillips
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - John A Tadross
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK; Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Sarah J Kinston
- Department of Haematology, Wellcome and MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Ernesto Ciabatti
- Department of Haematology, Wellcome and MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Berthold Göttgens
- Department of Haematology, Wellcome and MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Marco Tripodi
- MRC Laboratory of Molecular Biology, Neurobiology Division, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - David Hornigold
- Research and Early Development Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca Ltd, Cambridge, UK
| | - David Baker
- Research and Early Development Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca Ltd, Cambridge, UK
| | - Fiona M Gribble
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
| | - Frank Reimann
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
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Gay EA, Guan D, Van Voorhies K, Vasukuttan V, Mathews KM, Besheer J, Jin C. Discovery and Characterization of the First Nonpeptide Antagonists for the Relaxin-3/RXFP3 System. J Med Chem 2022; 65:7959-7974. [PMID: 35594150 DOI: 10.1021/acs.jmedchem.2c00508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The neuropeptide relaxin-3/RXFP3 system is involved in many important physiological processes such as stress responses, appetite control, and motivation for reward. To date, pharmacological studies of RXFP3 have been limited to peptide ligands. In this study, we report the discovery of the first small-molecule antagonists of RXFP3 through a high-throughput screening campaign. Focused structure-activity relationship studies of the hit compound resulted in RLX-33 (33) that was able to inhibit relaxin-3 activity in a battery of functional assays. RLX-33 is selective for RXFP3 over RXFP1 and RXFP4, two related members in the relaxin/insulin superfamily, and has favorable pharmacokinetic properties for behavioral assessment. When administered to rats intraperitoneally, RLX-33 blocked food intake induced by the RXFP3-selective agonist R3/I5. Collectively, our findings demonstrated that RLX-33 represents a promising antagonist scaffold for the development of drugs targeting the relaxin-3/RXFP3 system.
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Affiliation(s)
- Elaine A Gay
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, Research Triangle Park, North Carolina 27709, United States
| | - Dongliang Guan
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, Research Triangle Park, North Carolina 27709, United States
| | - Kalynn Van Voorhies
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Vineetha Vasukuttan
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, Research Triangle Park, North Carolina 27709, United States
| | - Kelly M Mathews
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, Research Triangle Park, North Carolina 27709, United States
| | - Joyce Besheer
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Chunyang Jin
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, Research Triangle Park, North Carolina 27709, United States
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8
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Erden S, Nalbant K, Kılınç İ. Investigation of Relaxin-3 Serum Levels in terms of Social Interaction, Communication, and Appetite as a Biomarker in Children with Autism. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2022; 20:135-142. [PMID: 35078956 PMCID: PMC8813315 DOI: 10.9758/cpn.2022.20.1.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/03/2021] [Accepted: 04/05/2021] [Indexed: 12/02/2022]
Abstract
Objective To investigate the possible relationship between relaxin-3 and autism spectrum disorder (ASD). Methods Serum relaxin-3 was measured in 80 children (50 children diagnosed with ASD and 30 controls). Symptom severity in the ASD group was evaluated by the Childhood Autism Rating Scale (CARS). Behavioral and nutritional problems in the groups were evaluated using the Abnormal Behavior Checklist (ABC) and the Childrenʼs Eating Behavior Questionnaire (CEBQ). Results Our findings showed that serum relaxin-3 levels were higher in children with ASD than in the controls. The listening response sub-scale score of the CARS scale was found to decrease as the level of relaxin-3 increased. However, as relaxin-3 levels increased in children with ASD, it was found that the speech problem sub-scale score on the ABC scale and the desire to drink score on the CEBQ scale increased, but the satiety responsiveness and food fussiness scores decreased. Conclusion This study the first to investigate serum levels of relaxin-3, which has a role in regulating social behavior and nutritional behavior in children with ASD.
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Affiliation(s)
- Semih Erden
- Department of Child and Adolescent Psychiatry, Necmettin Erbakan University Faculty of Medicine, Konya, Turkey
| | - Kevser Nalbant
- Department of Child and Adolescent Psychiatry, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - İbrahim Kılınç
- Department of Biochemistry, Necmettin Erbakan University Faculty of Medicine, Konya, Turkey
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9
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Lin G, Feng Y, Cai X, Zhou C, Shao L, Chen Y, Chen L, Liu Q, Zhou Q, Bathgate RA, Yang D, Wang MW. High-Throughput Screening Campaign Identified a Potential Small Molecule RXFP3/4 Agonist. Molecules 2021; 26:molecules26247511. [PMID: 34946593 PMCID: PMC8709172 DOI: 10.3390/molecules26247511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/01/2021] [Accepted: 12/09/2021] [Indexed: 11/16/2022] Open
Abstract
Relaxin/insulin-like family peptide receptor 3 (RXFP3) belongs to class A G protein-coupled receptor family. RXFP3 and its endogenous ligand relaxin-3 are mainly expressed in the brain with important roles in the regulation of appetite, energy metabolism, endocrine homeostasis and emotional processing. It is therefore implicated as a potential target for treatment of various central nervous system diseases. Since selective agonists of RXFP3 are restricted to relaxin-3 and its analogs, we conducted a high-throughput screening campaign against 32,021 synthetic and natural product-derived compounds using a cyclic adenosine monophosphate (cAMP) measurement-based method. Only one compound, WNN0109-C011, was identified following primary screening, secondary screening and dose-response studies. Although displayed agonistic effect in cells overexpressing the human RXFP3, it also showed cross-reactivity with the human RXFP4. This hit compound may provide not only a chemical probe to investigate the function of RXFP3/4, but also a novel scaffold for the development of RXFP3/4 agonists.
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Affiliation(s)
- Guangyao Lin
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China;
| | - Yang Feng
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
| | - Xiaoqing Cai
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
| | - Caihong Zhou
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
| | - Lijun Shao
- University of Chinese Academy of Sciences, Beijing 100049, China;
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yan Chen
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (Y.C.); (Q.Z.)
| | - Linhai Chen
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
| | - Qing Liu
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
| | - Qingtong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (Y.C.); (Q.Z.)
| | - Ross A.D. Bathgate
- Florey Institute of Neuroscience and Mental Health and Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3052, Australia;
| | - Dehua Yang
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China;
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- Research Center for Deepsea Bioresources, Sanya 572025, Hainan, China
- Correspondence: (D.Y.); (M.-W.W.)
| | - Ming-Wei Wang
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; (G.L.); (Y.F.); (X.C.); (C.Z.); (L.C.); (Q.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China;
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (Y.C.); (Q.Z.)
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- Research Center for Deepsea Bioresources, Sanya 572025, Hainan, China
- Correspondence: (D.Y.); (M.-W.W.)
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10
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Pustovit RV, Zhang X, Liew JJ, Praveen P, Liu M, Koo A, Oparija-Rogenmozere L, Ou Q, Kocan M, Nie S, Bathgate RA, Furness JB, Hossain MA. A Novel Antagonist Peptide Reveals a Physiological Role of Insulin-Like Peptide 5 in Control of Colorectal Function. ACS Pharmacol Transl Sci 2021; 4:1665-1674. [PMID: 34661082 DOI: 10.1021/acsptsci.1c00171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Indexed: 12/23/2022]
Abstract
Insulin-like peptide 5 (INSL5), the natural ligand for the relaxin family peptide receptor 4 (RXFP4), is a gut hormone that is exclusively produced by colonic L-cells. We have recently developed an analogue of INSL5, INSL5-A13, that acts as an RXFP4 agonist in vitro and stimulates colorectal propulsion in wild-type mice but not in RXFP4-knockout mice. These results suggest that INSL5 may have a physiological role in the control of colorectal motility. To investigate this possibility, in this study we designed and developed a novel INSL5 analogue, INSL5-A13NR. This compound is a potent antagonist, without significant agonist activity, in two in vitro assays. We report here for the first time that this novel antagonist peptide blocks agonist-induced increase in colon motility in mice that express RXFP4. Our data also show that colorectal propulsion induced by intracolonic administration of bacterial products (short-chain fatty acids, SCFAs) is antagonized by INSL5-A13NR. Therefore, INSL5-A13NR is an important research tool and potential drug lead for the treatment of colon motility disorders, such as bacterial diarrheas.
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Affiliation(s)
- Ruslan V Pustovit
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Xiaozhou Zhang
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Jamie Jm Liew
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Praveen Praveen
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Mengjie Liu
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ada Koo
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Lalita Oparija-Rogenmozere
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Qinghao Ou
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Martina Kocan
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Shuai Nie
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ross Ad Bathgate
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - John B Furness
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
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11
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Wong WLE, Dawe GS, Young AH. The putative role of the relaxin-3/RXFP3 system in clinical depression and anxiety: A systematic literature review. Neurosci Biobehav Rev 2021; 131:429-450. [PMID: 34537263 DOI: 10.1016/j.neubiorev.2021.09.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 12/14/2022]
Abstract
The relaxin-3/RXFP3 system is one of several neuropeptidergic systems putatively implicated in regulating the behavioural alterations that characterise clinical depression and anxiety, making it a potential target for clinical translation. Accordingly, this systematic review identified published reports on the role of relaxin-3/RXFP3 signalling in these neuropsychiatric disorders and their behavioural endophenotypes, evaluating evidence from animal and human studies to ascertain any relationship. We searched PubMed, EMBASE, PsycINFO and Google Scholar databases up to February 2021, finding 609 relevant records. After stringent screening, 51 of these studies were included in the final synthesis. There was considerable heterogeneity in study designs and some inconsistency across study outcomes. However, experimental evidence is consistent with an ability of relaxin-3/RXFP3 signalling to promote arousal and suppress depressive- and anxiety-like behaviour. Moreover, meta-analyses of six to eight articles investigating food intake revealed that acute RXFP3 activation had strong orexigenic effects in rats. This appraisal also identified the lack of high-quality clinical studies pertinent to the relaxin-3/RXFP3 system, a gap that future research should attempt to bridge.
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Affiliation(s)
- Win Lee Edwin Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.
| | - Gavin Stewart Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore
| | - Allan H Young
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom; South London & Maudsley NHS Foundation Trust, Bethlem Royal Hospital, Monks Orchard Road, London, United Kingdom
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12
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Gil-Miravet I, Mañas-Ojeda A, Ros-Bernal F, Castillo-Gómez E, Albert-Gascó H, Gundlach AL, Olucha-Bordonau FE. Involvement of the Nucleus Incertus and Relaxin-3/RXFP3 Signaling System in Explicit and Implicit Memory. Front Neuroanat 2021; 15:637922. [PMID: 33867946 PMCID: PMC8044989 DOI: 10.3389/fnana.2021.637922] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/26/2021] [Indexed: 12/18/2022] Open
Abstract
Telencephalic cognitive and emotional circuits/functions are strongly modulated by subcortical inputs. The main focus of past research on the nature of this modulation has been on the widespread monoamine projections to the telencephalon. However, the nucleus incertus (NI) of the pontine tegmentum provides a strong GABAergic and peptidergic innervation of the hippocampus, basal forebrain, amygdala, prefrontal cortex, and related regions; and represents a parallel source of ascending modulation of cognitive and emotional domains. NI GABAergic neurons express multiple peptides, including neuromedin-B, cholecystokinin, and relaxin-3, and receptors for stress and arousal transmitters, including corticotrophin-releasing factor and orexins/hypocretins. A functional relationship exists between NI neurons and their associated peptides, relaxin-3 and neuromedin-B, and hippocampal theta rhythm, which in turn, has a key role in the acquisition and extinction of declarative and emotional memories. Furthermore, RXFP3, the cognate receptor for relaxin-3, is a Gi/o protein-coupled receptor, and its activation inhibits the cellular accumulation of cAMP and induces phosphorylation of ERK, processes associated with memory formation in the hippocampus and amygdala. Therefore, this review summarizes the role of NI transmitter systems in relaying stress- and arousal-related signals to the higher neural circuits and processes associated with memory formation and retrieval.
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Affiliation(s)
- Isis Gil-Miravet
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain
| | - Aroa Mañas-Ojeda
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain
| | - Francisco Ros-Bernal
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain
| | - Esther Castillo-Gómez
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain.,Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Madrid, Spain
| | - Hector Albert-Gascó
- Department of Clinical Neurosciences, UK Dementia Research Institute, University of Cambridge, Cambridge, United Kingdom
| | - Andrew L Gundlach
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Francisco E Olucha-Bordonau
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain.,Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Madrid, Spain
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13
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Zhang X, Bathgate RAD, Hossain MA. Human Insulin-like Peptide 5 (INSL5). Identification of a Simplified Version of Two-Chain Analog A13. ACS Med Chem Lett 2020; 11:2455-2460. [PMID: 33335667 DOI: 10.1021/acsmedchemlett.0c00435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/08/2020] [Indexed: 01/14/2023] Open
Abstract
The receptor for insulin-like peptide 5 (INSL5), RXFP4, is a potential pharma target for treating human conditions such as constipation, anorexia, and obesity. However, since INSL5 has a complex structure of two chains and three disulfide bonds, its synthesis has proven to be extremely difficult via either chemical or recombinant approaches. Previous studies led to the engineering of a high yielding simplified INSL5 analog, named analog 13 (A13), which retains native INSL5-like activity. The focus of this study is to further simplify the structure of A13 by truncating the N-terminal residues of the B-chain. We have found that the first six residues at the N-terminus of A13 are not important for RXFP4 binding and cAMP potency. The most minimized active structure of INSL5 identified in this study is A13: B7-24 which will be an important research tool to study the physiological role of RXFP4 and a template for further modification to improve its pharmacokinetic properties.
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14
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Lee HS, Wang SH, Daniel JT, Hossain MA, Clark RJ, Bathgate RAD, Rosengren KJ. Exploring the Use of Helicogenic Amino Acids for Optimising Single Chain Relaxin-3 Peptide Agonists. Biomedicines 2020; 8:biomedicines8100415. [PMID: 33066369 PMCID: PMC7602263 DOI: 10.3390/biomedicines8100415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 11/16/2022] Open
Abstract
Relaxin-3 is a highly conserved two-chain neuropeptide that acts through its endogenous receptor the Relaxin Family Peptide-3 (RXFP3) receptor. The ligand/receptor system is known to modulate several physiological processes, with changes in food intake and anxiety-levels the most well studied in rodent models. Agonist and antagonist analogues based on the native two-chain peptide are costly to synthesise and not ideal drug leads. Since RXFP3 interacting residues are found in the relaxin B-chain only, this has been the focus of analogue development. The B-chain is unstructured without the A-chain support, but in single-chain variants structure can be induced by dicarba-based helical stapling strategies. Here we investigated whether alternative helical inducing strategies also can enhance structure and activity at RXFP3. Combinations of the helix inducing α-aminoisobutyric acid (Aib) were incorporated into the sequence of the relaxin-3 B-chain. Aib residues at positions 13, 17 and 18 partially reintroduce helicity and activity of the relaxin-3 B-chain, but other positions are generally not suited for modifications. We identify Thr21 as a putative new receptor contact residue important for RXFP3 binding. Cysteine residues were also incorporated into the sequence and cross-linked with dichloroacetone or α, α'-dibromo-m-xylene. However, in contrast to previously reported dicarba variants, neither were found to promote structure and RXFP3 activity.
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Affiliation(s)
- Han Siean Lee
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia; (H.S.L.); (S.H.W.); (J.T.D.); (R.J.C.)
| | - Shu Hui Wang
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia; (H.S.L.); (S.H.W.); (J.T.D.); (R.J.C.)
| | - James T. Daniel
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia; (H.S.L.); (S.H.W.); (J.T.D.); (R.J.C.)
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC 3052, Australia; (M.A.H.); (R.A.D.B.)
- School of Chemistry, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Richard J. Clark
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia; (H.S.L.); (S.H.W.); (J.T.D.); (R.J.C.)
| | - Ross A. D. Bathgate
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC 3052, Australia; (M.A.H.); (R.A.D.B.)
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - K. Johan Rosengren
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia; (H.S.L.); (S.H.W.); (J.T.D.); (R.J.C.)
- Correspondence:
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15
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Li HZ, Li N, Shao XX, Liu YL, Xu ZG, Guo ZY. Hydrophobic interactions of relaxin family peptide receptor 3 with ligands identified using a NanoBiT-based binding assay. Biochimie 2020; 177:117-126. [PMID: 32810565 DOI: 10.1016/j.biochi.2020.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/23/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
Relaxin family peptide receptor 3 (RXFP3) is a G protein-coupled receptor implicated in the regulation of food intake and stress response upon activation by the neuropeptide relaxin-3. In recent studies, interactions of RXFP3 with some natural or synthetic ligands have been investigated. In the present study, we identified the hydrophobic interactions of human RXFP3 with the chimeric agonist R3/I5 and the chimeric antagonist R3(ΔB23-27)R/I5 using a newly developed NanoBiT-based homogenous binding assay. We first demonstrated that the conserved large aliphatic B15Ile and B19Ile were important for the binding of the agonist and antagonist to RXFP3, because alanine replacement significantly decreased their receptor-binding potency. Thereafter, we demonstrated that the conserved large aliphatic Leu246 and Leu248 in extracellular loop 2 were important for RXFP3 binding to the agonist and antagonist, because alanine replacement significantly decreased the binding affinity of RXFP3 for both ligands. Finally, we deduced probable hydrophobic interactions based on the ability of RXFP3 mutants to distinguish the wild-type and mutant ligands: Leu246 of RXFP3 interacted with B15Ile of both ligands, while Leu248 of RXFP3 interacted with both B15Ile and B19Ile of the agonist and antagonist. The present results not only provided new insights into the interaction mechanism of RXFP3 with agonists and antagonists, but also demonstrated usefulness of the NanoBiT-based homogenous binding assay to study the interaction mechanism of certain receptors with their ligands.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ning Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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16
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de Ávila C, Chometton S, Ma S, Pedersen LT, Timofeeva E, Cifani C, Gundlach AL. Effects of chronic silencing of relaxin-3 production in nucleus incertus neurons on food intake, body weight, anxiety-like behaviour and limbic brain activity in female rats. Psychopharmacology (Berl) 2020; 237:1091-1106. [PMID: 31897576 DOI: 10.1007/s00213-019-05439-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 12/17/2019] [Indexed: 10/25/2022]
Abstract
Eating disorders are frequently triggered by stress and are more prevalent in women than men. First signs often appear during early adolescence, but the biological basis for the sex-specific differences is unknown. Central administration of native relaxin-3 (RLN3) peptide or chimeric/truncated analogues produces differential effects on food intake and HPA axis activity in adult male and female rats, but the precise role of endogenous RLN3 signalling in metabolic and neuroendocrine control is unclear. Therefore, we examined the effects of microRNA-induced depletion (knock-down) of RLN3 mRNA/(peptide) production in neurons of the brainstem nucleus incertus (NI) in female rats on a range of physiological, behavioural and neurochemical indices, including food intake, body weight, anxiety, plasma corticosterone, mRNA levels of key neuropeptides in the paraventricular nucleus of hypothalamus (PVN) and limbic neural activity patterns (reflected by c-fos mRNA). Validated depletion of RLN3 in NI neurons of female rats (n = 8) produced a small, sustained (~ 2%) decrease in body weight, an imbalance in food intake and an increase in anxiety-like behaviour in the large open field, but not in the elevated plus-maze or light/dark box. Furthermore, NI RLN3 depletion disrupted corticosterone regulation, increased oxytocin and arginine-vasopressin, but not corticotropin-releasing factor, mRNA, in PVN, and decreased basal levels of c-fos mRNA in parvocellular and magnocellular PVN, bed nucleus of stria terminalis and the lateral hypothalamic area, brain regions involved in stress and feeding. These findings support a role for NI RLN3 neurons in fine-tuning stress and neuroendocrine responses and food intake regulation in female rats.
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Affiliation(s)
- Camila de Ávila
- Department of Psychiatry and Neuroscience, CRIUCPQ, Faculty of Medicine, Université Laval, Québec, Canada. .,The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia. .,NNF CBMR, Nutrient and Metabolite Sensing, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark.
| | - Sandrine Chometton
- Department of Psychiatry and Neuroscience, CRIUCPQ, Faculty of Medicine, Université Laval, Québec, Canada
| | - Sherie Ma
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Lola Torz Pedersen
- NNF CBMR, Nutrient and Metabolite Sensing, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Elena Timofeeva
- Department of Psychiatry and Neuroscience, CRIUCPQ, Faculty of Medicine, Université Laval, Québec, Canada
| | - Carlo Cifani
- Department of Psychiatry and Neuroscience, CRIUCPQ, Faculty of Medicine, Université Laval, Québec, Canada.,Pharmacology Unit, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.
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17
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Lee HS, Postan M, Song A, Clark RJ, Bathgate RAD, Haugaard-Kedström LM, Rosengren KJ. Development of Relaxin-3 Agonists and Antagonists Based on Grafted Disulfide-Stabilized Scaffolds. Front Chem 2020; 8:87. [PMID: 32133341 PMCID: PMC7039932 DOI: 10.3389/fchem.2020.00087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/27/2020] [Indexed: 12/22/2022] Open
Abstract
Relaxin-3 is a neuropeptide with important roles in metabolism, arousal, learning and memory. Its cognate receptor is the relaxin family peptide-3 (RXFP3) receptor. Relaxin-3 agonist and antagonist analogs have been shown to be able to modulate food intake in rodent models. The relaxin-3 B-chain is sufficient for receptor interactions, however, in the absence of a structural support, linear relaxin-3 B-chain analogs are rapidly degraded and thus unsuitable as drug leads. In this study, two different disulfide-stabilized scaffolds were used for grafting of important relaxin-3 B-chain residues to improve structure and stability. The use of both Veronica hederifolia Trypsin inhibitor (VhTI) and apamin grafting resulted in agonist and antagonist analogs with improved helicity. VhTI grafted peptides showed poor binding and low potency at RXFP3, on the other hand, apamin variants retained significant activity. These variants also showed improved half-life in serum from ~5 min to >6 h, and thus are promising RXFP3 specific pharmacological tools and drug leads for neuropharmacological diseases.
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Affiliation(s)
- Han Siean Lee
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Michael Postan
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Angela Song
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Richard J Clark
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Ross A D Bathgate
- Florey Department of Neuroscience and Mental Health, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Linda M Haugaard-Kedström
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - K Johan Rosengren
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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18
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Engineering of chimeric peptides as antagonists for the G protein-coupled receptor, RXFP4. Sci Rep 2019; 9:17828. [PMID: 31780677 PMCID: PMC6882824 DOI: 10.1038/s41598-019-53707-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/05/2019] [Indexed: 11/20/2022] Open
Abstract
Insulin-like peptide 5 (INSL5) is a very important pharma target for treating human conditions such as anorexia and diabetes. However, INSL5 with two chains and three disulfide bridges is an extremely difficult peptide to assemble by chemical or recombinant means. In a recent study, we were able to engineer a simplified INSL5 analogue 13 which is a relaxin family peptide receptor 4 (RXFP4)-specific agonist. To date, however, no RXFP4-specific antagonist (peptide or small molecule) has been reported in the literature. The focus of this study was to utilize the non-specific RXFP3/RXFP4 antagonist ΔR3/I5 as a template to rationally design an RXFP4 specific antagonist. Unexpectedly, we demonstrated that ΔR3/I5 exhibited partial agonism at RXFP4 when expressed in CHO cells which is associated with only partial antagonism of INSL5 analogue activation. In an attempt to improve RXFP4 specificity and antagonist activity we designed and chemically synthesized a series of analogues of ΔR3/I5. While all the chimeric analogues still demonstrated partial agonism at RXFP4, one peptide (Analogue 17) exhibited significantly improved RXFP4 specificity. Importantly, analogue 17 has a simplified structure which is more amenable to chemical synthesis. Therefore, analogue 17 is an ideal template for further development into a specific high affinity RXFP4 antagonist which will be an important tool to probe the physiological role of RXFP4/INSL5 axis.
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19
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Marwari S, Poulsen A, Shih N, Lakshminarayanan R, Kini RM, Johannes CW, Dymock BW, Dawe GS. Intranasal administration of a stapled relaxin-3 mimetic has anxiolytic- and antidepressant-like activity in rats. Br J Pharmacol 2019; 176:3899-3923. [PMID: 31220339 PMCID: PMC6811745 DOI: 10.1111/bph.14774] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 05/27/2019] [Accepted: 06/04/2019] [Indexed: 12/17/2022] Open
Abstract
Background and Purpose Depression and anxiety are common causes of disability, and innovative tools and potential pharmacological targets are actively sought for prevention and treatment. Therapeutic strategies targeting the relaxin‐3 peptide or its primary endogenous receptor, RXFP3, for the treatment of major depression and anxiety disorders have been limited by a lack of compounds with drug‐like properties. We proposed that a hydrocarbon‐stapled mimetic of relaxin‐3, when administered intranasally, might be uniquely applicable to the treatment of these disorders. Experimental Approach We designed a series of hydrocarbon‐stapled relaxin‐3 mimetics and identified the most potent compound using in vitro receptor binding and activation assays. Further, we assessed the effect of intranasal delivery of relaxin‐3 and the lead stapled mimetic in rat models of anxiety and depression. Key Results We developed an i,i+7 stapled relaxin‐3 mimetic that manifested a stabilized α‐helical structure, proteolytic resistance, and confirmed agonist activity in receptor binding and activation in vitro assays. The stapled peptide agonist enhanced food intake after intracerebral infusion in rats, confirming in vivo activity. We showed that intranasal delivery of the lead i,i+7 stapled peptide or relaxin‐3 had orexigenic effects in rats, indicating a potential clinically translatable route of delivery. Further, intranasal administration of the lead i,i+7 stapled peptide exerted anxiolytic and antidepressant‐like activity in anxiety‐ and depression‐related behaviour paradigms. Conclusions and Implications Our preclinical findings demonstrate that targeting the relaxin‐3/RXFP3 receptor system via intranasal delivery of an i,i+7 stapled relaxin‐3 mimetic may represent an effective treatment approach for depression, anxiety, and related neuropsychiatric disorders.
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Affiliation(s)
- Subhi Marwari
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Anders Poulsen
- Department of Medicinal Chemistry, Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Norrapat Shih
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Rajamani Lakshminarayanan
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - R Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Charles William Johannes
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Brian William Dymock
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Gavin Stewart Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore
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20
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Praveen P, Kocan M, Valkovic A, Bathgate R, Hossain MA. Single chain peptide agonists of relaxin receptors. Mol Cell Endocrinol 2019; 487:34-39. [PMID: 30641102 DOI: 10.1016/j.mce.2019.01.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 12/16/2022]
Abstract
There are seven human relaxin family peptides that have two chains (A and B) and three disulfide bonds. The target receptors for four of these peptides are known as relaxin family peptide receptors, RXFP1-RXFP4. Detailed structure-activity relationship (SAR) studies of relaxin family peptides have been reported over the years and have led to the design of new analogs with agonistic and antagonistic properties. This review briefly summarizes the SAR of human relaxin 2 (H2 relaxin) and human relaxin 3 (H3 relaxin) leading to the design and development of single-B-chain only agonists, B7-33 and peptide 5. The physiological functions of these new peptides agonists in cellular and animal models are also described.
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Affiliation(s)
- Praveen Praveen
- Florey Institute for Neuroscience & Mental Health, VIC, Australia
| | - Martina Kocan
- Florey Institute for Neuroscience & Mental Health, VIC, Australia
| | - Adam Valkovic
- Florey Institute for Neuroscience & Mental Health, VIC, Australia
| | - Ross Bathgate
- Florey Institute for Neuroscience & Mental Health, VIC, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, VIC, Australia
| | - Mohammed Akhter Hossain
- Florey Institute for Neuroscience & Mental Health, VIC, Australia; School of Chemistry and Bio21, University of Melbourne, University of Melbourne, VIC, Australia.
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21
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Wang JH, Nie WH, Shao XX, Li HZ, Hu MJ, Liu YL, Xu ZG, Guo ZY. Exploring electrostatic interactions of relaxin family peptide receptor 3 and 4 with ligands using a NanoBiT-based binding assay. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:776-786. [DOI: 10.1016/j.bbamem.2019.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 12/15/2022]
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22
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Haidar M, Tin K, Zhang C, Nategh M, Covita J, Wykes AD, Rogers J, Gundlach AL. Septal GABA and Glutamate Neurons Express RXFP3 mRNA and Depletion of Septal RXFP3 Impaired Spatial Search Strategy and Long-Term Reference Memory in Adult Mice. Front Neuroanat 2019; 13:30. [PMID: 30906254 PMCID: PMC6419585 DOI: 10.3389/fnana.2019.00030] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 02/20/2019] [Indexed: 12/11/2022] Open
Abstract
Relaxin-3 is a highly conserved neuropeptide abundantly expressed in neurons of the nucleus incertus (NI), which project to nodes of the septohippocampal system (SHS) including the medial septum/diagonal band of Broca (MS/DB) and dorsal hippocampus, as well as to limbic circuits. High densities of the Gi/o-protein-coupled receptor for relaxin-3, known as relaxin-family peptide-3 receptor (RXFP3) are expressed throughout the SHS, further suggesting a role for relaxin-3/RXFP3 signaling in modulating learning and memory processes that occur within these networks. Therefore, this study sought to gain further anatomical and functional insights into relaxin-3/RXFP3 signaling in the mouse MS/DB. Using Cre/LoxP recombination methods, we assessed locomotion, exploratory behavior, and spatial learning and long-term reference memory in adult C57BL/6J Rxfp3 loxP/loxP mice with targeted depletion of Rxfp3 in the MS/DB. Following prior injection of an AAV(1/2)-Cre-IRES-eGFP vector into the MS/DB to delete/deplete Rxfp3 mRNA/RXFP3 protein, mice tested in a Morris water maze (MWM) displayed an impairment in allocentric spatial learning during acquisition, as well as an impairment in long-term reference memory on probe day. However, RXFP3-depleted and control mice displayed similar motor activity in a locomotor cell and exploratory behavior in a large open-field (LOF) test. A quantitative characterization using multiplex, fluorescent in situ hybridization (ISH) identified a high level of co-localization of Rxfp3 mRNA and vesicular GABA transporter (vGAT) mRNA in MS and DB neurons (~87% and ~95% co-expression, respectively). Rxfp3 mRNA was also detected, to a correspondingly lesser extent, in vesicular glutamate transporter 2 (vGlut2) mRNA-containing neurons in MS and DB (~13% and ~5% co-expression, respectively). Similarly, a qualitative assessment of the MS/DB region, identified Rxfp3 mRNA in neurons that expressed parvalbumin (PV) mRNA (reflecting hippocampally-projecting GABA neurons), whereas choline acetyltransferase mRNA-positive (acetylcholine) neurons lacked Rxfp3 mRNA. These data are consistent with a qualitative immunohistochemical analysis that revealed relaxin-3-immunoreactive nerve fibers in close apposition with PV-immunoreactive neurons in the MS/DB. Together these studies suggest relaxin-3/RXFP3 signaling in the MS/DB plays a role in modulating specific learning and long-term memory associated behaviors in adult mice via effects on GABAergic neuron populations known for their involvement in modulating hippocampal theta rhythm and associated cognitive processes.
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Affiliation(s)
- Mouna Haidar
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Kimberly Tin
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Cary Zhang
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Mohsen Nategh
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - João Covita
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Alexander D. Wykes
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Jake Rogers
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Andrew L. Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
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23
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Wong LLL, Scott DJ, Hossain MA, Kaas Q, Rosengren KJ, Bathgate RAD. Distinct but overlapping binding sites of agonist and antagonist at the relaxin family peptide 3 (RXFP3) receptor. J Biol Chem 2018; 293:15777-15789. [PMID: 30131340 DOI: 10.1074/jbc.ra118.002645] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/09/2018] [Indexed: 12/22/2022] Open
Abstract
The relaxin-3 neuropeptide activates the relaxin family peptide 3 (RXFP3) receptor to modulate stress, appetite, and cognition. RXFP3 shows promise as a target for treating neurological disorders, but realization of its clinical potential requires development of smaller RXFP3-specific drugs that can penetrate the blood-brain barrier. Designing such drugs is challenging and requires structural knowledge of agonist- and antagonist-binding modes. Here, we used structure-activity data for relaxin-3 and a peptide RXFP3 antagonist termed R3 B1-22R to guide receptor mutagenesis and develop models of their binding modes. RXFP3 residues were alanine-substituted individually and in combination and tested in cell-based binding and functional assays to refine models of agonist and antagonist binding to active- and inactive-state homology models of RXFP3, respectively. These models suggested that both agonists and antagonists interact with RXFP3 via similar residues in their B-chain central helix. The models further suggested that the B-chain Trp27 inserts into the binding pocket of RXFP3 and interacts with Trp138 and Lys271, the latter through a salt bridge with the C-terminal carboxyl group of Trp27 in relaxin-3. R3 B1-22R, which does not contain Trp27, used a non-native Arg23 residue to form cation-π and salt-bridge interactions with Trp138 and Glu141 in RXFP3, explaining a key contribution of Arg23 to affinity. Overall, relaxin-3 and R3 B1-22R appear to share similar binding residues but may differ in binding modes, leading to active and inactive RXFP3 conformational states, respectively. These mechanistic insights may assist structure-based drug design of smaller relaxin-3 mimetics to manage neurological disorders.
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Affiliation(s)
| | - Daniel James Scott
- From the Florey Institute of Neuroscience and Mental Health.,Department of Biochemistry and Molecular Biology, and
| | - Mohammed Akhter Hossain
- From the Florey Institute of Neuroscience and Mental Health.,School of Chemistry, University of Melbourne, Parkville, Victoria 3052, Australia and
| | | | - K Johan Rosengren
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ross A D Bathgate
- From the Florey Institute of Neuroscience and Mental Health, .,Department of Biochemistry and Molecular Biology, and
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24
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Haugaard-Kedström LM, Lee HS, Jones MV, Song A, Rathod V, Hossain MA, Bathgate RAD, Rosengren KJ. Binding conformation and determinants of a single-chain peptide antagonist at the relaxin-3 receptor RXFP3. J Biol Chem 2018; 293:15765-15776. [PMID: 30131342 DOI: 10.1074/jbc.ra118.002611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/27/2018] [Indexed: 12/15/2022] Open
Abstract
The neuropeptide relaxin-3 and its receptor relaxin family peptide receptor-3 (RXFP3) play key roles in modulating behavior such as memory and learning, food intake, and reward seeking. A linear relaxin-3 antagonist (R3 B1-22R) based on a modified and truncated relaxin-3 B-chain was recently developed. R3 B1-22R is unstructured in solution; thus, the binding conformation and determinants of receptor binding are unclear. Here, we have designed, chemically synthesized, and pharmacologically characterized more than 60 analogues of R3 B1-22R to develop an extensive understanding of its structure-activity relationships. We show that the key driver for affinity is the nonnative C-terminal Arg23 Additional contributors to binding include amino acid residues that are important also for relaxin-3 binding, including Arg12, Ile15, and Ile19 Intriguingly, amino acid residues that are not exposed in native relaxin-3, including Phe14 and Ala17, also interact with RXFP3. We show that R3 B1-22R has a propensity to form a helical structure, and modifications that support a helical conformation are functionally well-tolerated, whereas helix breakers such as proline residues disrupt binding. These data suggest that the peptide adopts a helical conformation, like relaxin-3, upon binding to RXFP3, but that its smaller size allows it to penetrate deeper into the orthosteric binding site, creating more extensive contacts with the receptor.
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Affiliation(s)
- Linda M Haugaard-Kedström
- From the Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.,the Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark, and
| | - Han Siean Lee
- From the Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Maryon V Jones
- From the Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Angela Song
- From the Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Vishaal Rathod
- From the Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | | | - Ross A D Bathgate
- the Florey Institute of Neuroscience and Mental Health, .,Department of Biochemistry and Molecular Biology, University of Melbourne, Victoria 3010, Australia
| | - K Johan Rosengren
- From the Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia,
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25
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Hu MJ, Wang JH, Shao XX, Liu YL, Xu ZG, Guo ZY. Overexpression of relaxin family peptide receptor 3 in Escherichia coli and characterization of its ligand binding properties. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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26
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Wang JH, Hu MJ, Shao XX, Wei D, Liu YL, Xu ZG, Guo ZY. Cholesterol modulates the binding properties of human relaxin family peptide receptor 3 with its ligands. Arch Biochem Biophys 2018; 646:24-30. [PMID: 29601823 DOI: 10.1016/j.abb.2018.03.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 03/10/2018] [Accepted: 03/26/2018] [Indexed: 12/14/2022]
Abstract
Relaxin family peptide receptor 3 (RXFP3) is implicated in the regulation of food intake and stress response upon activation by its cognate agonist relaxin-3. As an A-class G protein-coupled receptor, RXFP3 is an integral plasma membrane protein with seven transmembrane domains, yet influence of the membrane lipids on its function remains unknown. In the present study, we disclosed that cholesterol, an essential membrane lipid for mammalian cells, modulated the binding properties of human RXFP3 with its ligands. We first demonstrated that depletion of cholesterol from host human embryonic kidney (HEK) 293T cells by methyl-β-cyclodextrin altered ligand-binding properties of the overexpressed human RXFP3, such as increasing its binding potency with some antagonists and decreasing its binding affinity with a NanoLuc-conjugated R3/I5 tracer. Thereafter, we demonstrated that two B-chain residues, B5Tyr and B12Arg, were primarily responsible for the increased binding potency of these antagonists with human RXFP3 under the cholesterol depletion condition. Our results suggest that cell membrane cholesterol interacts with human RXFP3 and modulates its ligand-binding properties, providing new insights into the influence of membrane lipids on RXFP3 function.
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Affiliation(s)
- Jia-Hui Wang
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng-Jun Hu
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Dian Wei
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Centre for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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27
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Olucha-Bordonau FE, Albert-Gascó H, Ros-Bernal F, Rytova V, Ong-Pålsson EKE, Ma S, Sánchez-Pérez AM, Gundlach AL. Modulation of forebrain function by nucleus incertus and relaxin-3/RXFP3 signaling. CNS Neurosci Ther 2018; 24:694-702. [PMID: 29722152 DOI: 10.1111/cns.12862] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/22/2018] [Accepted: 03/28/2018] [Indexed: 01/05/2023] Open
Abstract
The nucleus incertus (NI) in the pontine tegmentum sends ascending projections to the midbrain, hypothalamus, amygdala, basal forebrain, hippocampus, and prefrontal cortex, and has a postulated role in modulating several forebrain functions. A substantial population of GABAergic NI neurons expresses the neuropeptide, relaxin-3, which acts via the Gi/o -protein-coupled receptor, RXFP3, present throughout the forebrain target regions. Broad and specific manipulations of these systems by activation or inhibition of the NI or modulating RXFP3 signaling have revealed key insights into the likely influence of the NI/relaxin-3/RXFP3 system on modalities including arousal, feeding, stress responses, anxiety and addiction, and attention and memory. This range of actions corresponds to a likely impact of NI/(relaxin-3) projections on multiple integrated circuits, but makes it difficult to draw conclusions about a generalized function for this network. This review will focus on the key physiological process of oscillatory theta rhythm and the neural circuits that promote it during behavioral activation, highlighting the ability of NI and relaxin-3/RXFP3 signaling systems to modulate these circuits. A better understanding of these mechanisms may provide a way to therapeutically adjust malfunction of forebrain activity present in several pathological conditions.
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Affiliation(s)
| | - Héctor Albert-Gascó
- Department of Medicine, School of Health Sciences, Universitat Jaume I, Castellón de la Plana, Spain
| | - Francisco Ros-Bernal
- Department of Medicine, School of Health Sciences, Universitat Jaume I, Castellón de la Plana, Spain
| | - Valeria Rytova
- The Florey Institute of Neuroscience and Mental Health, Parkville, Vic., Australia
| | - Emma K E Ong-Pålsson
- The Florey Institute of Neuroscience and Mental Health, Parkville, Vic., Australia
| | - Sherie Ma
- The Florey Institute of Neuroscience and Mental Health, Parkville, Vic., Australia
| | - Ana M Sánchez-Pérez
- Department of Medicine, School of Health Sciences, Universitat Jaume I, Castellón de la Plana, Spain
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, Vic., Australia
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28
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Hossain MA, Bathgate RAD. Challenges in the design of insulin and relaxin/insulin-like peptide mimetics. Bioorg Med Chem 2017; 26:2827-2841. [PMID: 28988628 DOI: 10.1016/j.bmc.2017.09.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/19/2017] [Accepted: 09/19/2017] [Indexed: 12/20/2022]
Abstract
Peptidomimetics are designed to overcome the poor pharmacokinetics and pharmacodynamics associated with the native peptide or protein on which they are based. The design of peptidomimetics starts from developing structure-activity relationships of the native ligand-target pair that identify the key residues that are responsible for the biological effect of the native peptide or protein. Then minimization of the structure and introduction of constraints are applied to create the core active site that can interact with the target with high affinity and selectivity. Developing peptidomimetics is not trivial and often challenging, particularly when peptides' interaction mechanism with their target is complex. This review will discuss the challenges of developing peptidomimetics of therapeutically important insulin superfamily peptides, particularly those which have two chains (A and B) and three disulfide bonds and whose receptors are known, namely insulin, H2 relaxin, H3 relaxin, INSL3 and INSL5.
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Affiliation(s)
- Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3010, Australia; School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Ross A D Bathgate
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3010, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC 3010, Australia.
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29
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Wei D, Hu MJ, Shao XX, Wang JH, Nie WH, Liu YL, Xu ZG, Guo ZY. Development of a selective agonist for relaxin family peptide receptor 3. Sci Rep 2017; 7:3230. [PMID: 28607363 PMCID: PMC5468247 DOI: 10.1038/s41598-017-03465-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/27/2017] [Indexed: 12/01/2022] Open
Abstract
Relaxin family peptides perform a variety of biological functions by activating four G protein-coupled receptors, namely RXFP1–4. Among these receptors, RXFP3 lacks a specific natural or synthetic agonist at present. A previously designed chimeric R3/I5 peptide, consisting of the B-chain of relaxin-3 and the A-chain of INSL5, displays equal activity towards the homologous RXFP3 and RXFP4. To increase its selectivity towards RXFP3, in the present study we conducted extensive mutagenesis around the B-chain C-terminal region of R3/I5. Decreasing or increasing the peptide length around the B23–B25 position dramatically lowered the activation potency of R3/I5 towards both RXFP3 and RXFP4. Substitution of B23Gly with Ala or Ser converted R3/I5 from an efficient agonist to a strong antagonist for RXFP3, but the mutants retained considerable activation potency towards RXFP4. Substitution of B24Gly increased the selectivity of R3/I5 towards RXFP3 over the homologous RXFP4. The best mutant, [G(B24)S]R3/I5, displayed 20-fold higher activation potency towards RXFP3 than towards RXFP4, meanwhile retained full activation potency at RXFP3. Thus, [G(B24)S]R3/I5 is the best RXFP3-selective agonist known to date. It is a valuable tool for investigating the physiological functions of RXFP3, and also a suitable template for developing RXFP3-specific agonists in future.
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Affiliation(s)
- Dian Wei
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng-Jun Hu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jia-Hui Wang
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Wei-Han Nie
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China.
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30
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Kania A, Gugula A, Grabowiecka A, de Ávila C, Blasiak T, Rajfur Z, Lewandowski MH, Hess G, Timofeeva E, Gundlach AL, Blasiak A. Inhibition of oxytocin and vasopressin neuron activity in rat hypothalamic paraventricular nucleus by relaxin-3-RXFP3 signalling. J Physiol 2017; 595:3425-3447. [PMID: 28098344 DOI: 10.1113/jp273787] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 12/23/2016] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Relaxin-3 is a stress-responsive neuropeptide that acts at its cognate receptor, RXFP3, to alter behaviours including feeding. In this study, we have demonstrated a direct, RXFP3-dependent, inhibitory action of relaxin-3 on oxytocin and vasopressin paraventricular nucleus (PVN) neuron electrical activity, a putative cellular mechanism of orexigenic actions of relaxin-3. We observed a Gαi/o -protein-dependent inhibitory influence of selective RXFP3 activation on PVN neuronal activity in vitro and demonstrated a direct action of RXFP3 activation on oxytocin and vasopressin PVN neurons, confirmed by their abundant expression of RXFP3 mRNA. Moreover, we demonstrated that RXFP3 activation induces a cadmium-sensitive outward current, which indicates the involvement of a characteristic magnocellular neuron outward potassium current. Furthermore, we identified an abundance of relaxin-3-immunoreactive axons/fibres originating from the nucleus incertus in close proximity to the PVN, but associated with sparse relaxin-3-containing fibres/terminals within the PVN. ABSTRACT The paraventricular nucleus of the hypothalamus (PVN) plays an essential role in the control of food intake and energy expenditure by integrating multiple neural and humoral inputs. Recent studies have demonstrated that intracerebroventricular and intra-PVN injections of the neuropeptide relaxin-3 or selective relaxin-3 receptor (RXFP3) agonists produce robust feeding in satiated rats, but the cellular and molecular mechanisms of action associated with these orexigenic effects have not been identified. In the present studies, using rat brain slices, we demonstrated that relaxin-3, acting through its cognate G-protein-coupled receptor, RXFP3, hyperpolarized a majority of putative magnocellular PVN neurons (88%, 22/25), including cells producing the anorexigenic neuropeptides, oxytocin and vasopressin. Importantly, the action of relaxin-3 persisted in the presence of tetrodotoxin and glutamate/GABA receptor antagonists, indicating its direct action on PVN neurons. Similar inhibitory effects on PVN oxytocin and vasopressin neurons were produced by the RXFP3 agonist, RXFP3-A2 (82%, 80/98 cells). In situ hybridization histochemistry revealed a strong colocalization of RXFP3 mRNA with oxytocin and vasopressin immunoreactivity in rat PVN neurons. A smaller percentage of putative parvocellular PVN neurons was sensitive to RXFP3-A2 (40%, 16/40 cells). These data, along with a demonstration of abundant peri-PVN and sparse intra-PVN relaxin-3-immunoreactive nerve fibres, originating from the nucleus incertus, the major source of relaxin-3 neurons, identify a strong inhibitory influence of relaxin-3-RXFP3 signalling on the electrical activity of PVN oxytocin and vasopressin neurons, consistent with the orexigenic effect of RXFP3 activation observed in vivo.
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Affiliation(s)
- Alan Kania
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Anna Gugula
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Agnieszka Grabowiecka
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Camila de Ávila
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada, G1V 0A6
| | - Tomasz Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Zenon Rajfur
- Faculty of Physics, Astronomy and Applied Computer Science, Institute of Physics, Jagiellonian University, 30-348, Krakow, Poland
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
| | - Grzegorz Hess
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland.,Institute of Pharmacology, Polish Academy of Sciences, 31-343, Krakow, Poland
| | - Elena Timofeeva
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada, G1V 0A6
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, 3052, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, VIC, 3010, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, VIC, 3010, Australia
| | - Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387, Krakow, Poland
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Wang JH, Shao XX, Hu MJ, Wei D, Liu YL, Xu ZG, Guo ZY. A novel BRET-based binding assay for interaction studies of relaxin family peptide receptor 3 with its ligands. Amino Acids 2017; 49:895-903. [PMID: 28161795 DOI: 10.1007/s00726-017-2387-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 01/27/2017] [Indexed: 01/06/2023]
Abstract
Relaxin family peptide receptor 3 (RXFP3) is an A-class G protein-coupled receptor that is implicated in the regulation of food intake and stress response upon activation by its cognate agonist relaxin-3. To study its interaction with various ligands, we developed a novel bioluminescence resonance energy transfer (BRET)-based binding assay using the brightest NanoLuc as an energy donor and a newly developed cyan-excitable orange fluorescent protein (CyOFP) as an energy acceptor. An engineered CyOFP without intrinsic cysteine residues but with an introduced cysteine at the C-terminus was overexpressed in Escherichia coli and chemically conjugated to the A-chain N-terminus of an easily labeled chimeric R3/I5 peptide via an intermolecular disulfide linkage. After the CyOFP-conjugated R3/I5 bound to a shortened human RXFP3 (removal of 33 N-terminal residues) fused with the NanoLuc reporter at the N-terminus, high BRET signals were detected. Saturation binding and real-time binding assays demonstrated that this BRET pair retained high binding affinity with fast association/dissociation. Using this BRET pair, binding potencies of various ligands with RXFP3 were conveniently measured through competition binding assays. Thus, the novel BRET-based binding assay facilitates interaction studies of RXFP3 with various ligands. The engineered CyOFP without intrinsic cysteine residues may also be applied to other BRET-based binding assays in future studies.
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Affiliation(s)
- Jia-Hui Wang
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng-Jun Hu
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Dian Wei
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China.
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Haidar M, Guèvremont G, Zhang C, Bathgate RAD, Timofeeva E, Smith CM, Gundlach AL. Relaxin-3 inputs target hippocampal interneurons and deletion of hilar relaxin-3 receptors in "floxed-RXFP3" mice impairs spatial memory. Hippocampus 2017; 27:529-546. [PMID: 28100033 DOI: 10.1002/hipo.22709] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 11/10/2022]
Abstract
Hippocampus is innervated by γ-aminobutyric acid (GABA) "projection" neurons of the nucleus incertus (NI), including a population expressing the neuropeptide, relaxin-3 (RLN3). In studies aimed at gaining an understanding of the role of RLN3 signaling in hippocampus via its Gi/o -protein-coupled receptor, RXFP3, we examined the distribution of RLN3-immunoreactive nerve fibres and RXFP3 mRNA-positive neurons in relation to hippocampal GABA neuron populations. RLN3-positive elements were detected in close-apposition with a substantial population of somatostatin (SST)- and GABA-immunoreactive neurons, and a smaller population of parvalbumin- and calretinin-immunoreactive neurons in different hippocampal areas, consistent with the relative distribution patterns of RXFP3 mRNA and these marker transcripts. In light of the functional importance of the dentate gyrus (DG) hilus in learning and memory, and our anatomical data, we examined the possible influence of RLN3/RXFP3 signaling in this region on spatial memory. Using viral-based Cre/LoxP recombination methods and adult mice with a floxed Rxfp3 gene, we deleted Rxfp3 from DG hilar neurons and assessed spatial memory performance and affective behaviors. Following infusions of an AAV(1/2) -Cre-IRES-eGFP vector, Cre expression was observed in DG hilar neurons, including SST-positive cells, and in situ hybridization histochemistry for RXFP3 mRNA confirmed receptor depletion relative to levels in floxed-RXFP3 mice infused with an AAV(1/2) -eGFP (control) vector. RXFP3 depletion within the DG hilus impaired spatial reference memory in an appetitive T-maze task reflected by a reduced percentage of correct choices and increased time to meet criteria, relative to control. In a continuous spontaneous alternation Y-maze task, RXFP3-depleted mice made fewer alternations in the first minute, suggesting impairment of spatial working memory. However, RXFP3-depleted and control mice displayed similar locomotor activity, anxiety-like behavior in light/dark box and elevated-plus maze tests, and learning and long-term memory retention in the Morris water maze. These data indicate endogenous RLN3/RXFP3 signaling can modulate hippocampal-dependent spatial reference and working memory via effects on SST interneurons, and further our knowledge of hippocampal cognitive processing. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- M Haidar
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia
| | - G Guèvremont
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Laval University, Quebec, Canada
| | - C Zhang
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia
| | - R A D Bathgate
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.,Department of Biochemistry and Molecular Biology, The University of Melbourne, Victoria, Australia
| | - E Timofeeva
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Laval University, Quebec, Canada
| | - C M Smith
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.,School of Medicine, Deakin University, Victoria, Australia
| | - A L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Victoria, Australia
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Patil NA, Rosengren KJ, Separovic F, Wade JD, Bathgate RAD, Hossain MA. Relaxin family peptides: structure-activity relationship studies. Br J Pharmacol 2017; 174:950-961. [PMID: 27922185 DOI: 10.1111/bph.13684] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/25/2016] [Accepted: 11/28/2016] [Indexed: 12/21/2022] Open
Abstract
The human relaxin peptide family consists of seven cystine-rich peptides, four of which are known to signal through relaxin family peptide receptors, RXFP1-4. As these peptides play a vital role physiologically and in various diseases, they are of considerable importance for drug discovery and development. Detailed structure-activity relationship (SAR) studies towards understanding the role of important residues in each of these peptides have been reported over the years and utilized for the design of antagonists and minimized agonist variants. This review summarizes the current knowledge of the SAR of human relaxin 2 (H2 relaxin), human relaxin 3 (H3 relaxin), human insulin-like peptide 3 (INSL3) and human insulin-like peptide 5 (INSL5). LINKED ARTICLES This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.
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Affiliation(s)
- Nitin A Patil
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.,School of Chemistry, University of Melbourne, Parkville, VIC, Australia
| | - K Johan Rosengren
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
| | - Frances Separovic
- School of Chemistry, University of Melbourne, Parkville, VIC, Australia
| | - John D Wade
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.,School of Chemistry, University of Melbourne, Parkville, VIC, Australia
| | - Ross A D Bathgate
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.,School of Chemistry, University of Melbourne, Parkville, VIC, Australia
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34
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Ma S, Smith CM, Blasiak A, Gundlach AL. Distribution, physiology and pharmacology of relaxin-3/RXFP3 systems in brain. Br J Pharmacol 2016; 174:1034-1048. [PMID: 27774604 DOI: 10.1111/bph.13659] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/12/2016] [Accepted: 10/17/2016] [Indexed: 01/29/2023] Open
Abstract
Relaxin-3 is a member of a superfamily of structurally-related peptides that includes relaxin and insulin-like peptide hormones. Soon after the discovery of the relaxin-3 gene, relaxin-3 was identified as an abundant neuropeptide in brain with a distinctive topographical distribution within a small number of GABAergic neuron populations that is well conserved across species. Relaxin-3 is thought to exert its biological actions through a single class-A GPCR - relaxin-family peptide receptor 3 (RXFP3). Class-A comprises GPCRs for relaxin-3 and insulin-like peptide-5 and other peptides such as orexin and the monoamine transmitters. The RXFP3 receptor is selectively activated by relaxin-3, whereas insulin-like peptide-5 is the cognate ligand for the related RXFP4 receptor. Anatomical and pharmacological evidence obtained over the last decade supports a function of relaxin-3/RXFP3 systems in modulating responses to stress, anxiety-related and motivated behaviours, circadian rhythms, and learning and memory. Electrophysiological studies have identified the ability of RXFP3 agonists to directly hyperpolarise thalamic neurons in vitro, but there are no reports of direct cell signalling effects in vivo. This article provides an overview of earlier studies and highlights more recent research that implicates relaxin-3/RXFP3 neural network signalling in the integration of arousal, motivation, emotion and related cognition, and that has begun to identify the associated neural substrates and mechanisms. Future research directions to better elucidate the connectivity and function of different relaxin-3 neuron populations and their RXFP3-positive target neurons in major experimental species and humans are also identified. LINKED ARTICLES This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.
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Affiliation(s)
- Sherie Ma
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia
| | - Craig M Smith
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.,School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Victoria, Australia
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35
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The actions of relaxin family peptides on signal transduction pathways activated by the relaxin family peptide receptor RXFP4. Naunyn Schmiedebergs Arch Pharmacol 2016; 390:105-111. [PMID: 27888281 DOI: 10.1007/s00210-016-1321-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 11/18/2016] [Indexed: 01/06/2023]
Abstract
The relaxin family peptide receptor 4 (RXFP4) is a G protein-coupled receptor (GPCR) expressed in the colorectum with emerging roles in metabolism and appetite regulation. It is activated by its cognate ligand insulin-like peptide 5 (INSL5) that is expressed in enteroendocrine L cells in the gut. Whether other evolutionarily related peptides such as relaxin-2, relaxin-3, or INSL3 activate RXFP4 signal transduction mechanisms with a pattern similar to or distinct from INSL5 is still unclear. In this study, we compare the signaling pathways activated by various relaxin family peptides to INSL5. We found that, like INSL5, relaxin-3 activated ERK1/2, p38MAPK, Akt, and S6RP phosphorylations leading to increased cell proliferation and also caused GRK and β-arrestin-mediated receptor internalization. Interestingly, relaxin-3 was slightly more potent than INSL5 in ERK1/2 and Akt phosphorylations, but both peptides were almost equipotent in adenylyl cyclase inhibition, S6RP phosphorylation, and cell proliferation. In addition, relaxin-3 showed greater efficacy only in Akt phosphorylation but not in the other pathways investigated. In contrast, no signaling activity or receptor internalization mechanisms were observed following relaxin-2 and INSL3. In conclusion, relaxin-3 is a high-efficacy agonist at RXFP4 with a comparable signal transduction profile to INSL5.
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Jayakody T, Marwari S, Lakshminarayanan R, Tan FCK, Johannes CW, Dymock BW, Poulsen A, Herr DR, Dawe GS. Hydrocarbon stapled B chain analogues of relaxin-3 retain biological activity. Peptides 2016; 84:44-57. [PMID: 27498038 DOI: 10.1016/j.peptides.2016.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 07/29/2016] [Accepted: 08/02/2016] [Indexed: 11/30/2022]
Abstract
Relaxin-3 or insulin-like peptide 7 (INSL7) is the most recently discovered relaxin/insulin-like family peptide. Mature relaxin-3 consists of an A chain and a B chain held by disulphide bonds. According to structure activity relationship studies, the relaxin-3 B chain is more important in binding and activating the receptor. RXFP3 (also known as Relaxin-3 receptor 1, GPCR 135, somatostatin- and angiotensin- like peptide receptor or SALPR) was identified as the cognate receptor for relaxin-3 by expression profiles and binding studies. Recent studies imply roles of this system in mediating stress and anxiety, feeding, metabolism and cognition. Stapling of peptides is a technique used to develop peptide drugs for otherwise undruggable targets. The main advantages of stapling include, increased activity due to reduced proteolysis, increased affinity to receptors and increased cell permeability. Stable agonists and antagonists of RXFP3 are crucial for understanding the physiological significance of this system. So far, agonists and antagonists of RXFP3 are peptides. In this study, for the first time, we have introduced stapling of the relaxin-3 B chain at 14th and 18th positions (14s18) and 18th and 22nd position (18s22). These stapled peptides showed greater helicity than the unstapled relaxin-3 B chain in circular dichroism analysis. Both stapled peptides bound RXFP3 and activated RXFP3 as observed in an inhibition of forskolin-induced cAMP assay and a ERK1/2 activation assay, although with different potencies. Therefore, we conclude that stapling of the relaxin3 B chain does not compromise its ability to activate RXFP3 and is a promising method for developing stable peptide agonists and antagonists of RXFP3 to aid relaxin-3/RXFP3 research.
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Affiliation(s)
- Tharindunee Jayakody
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore; Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, Singapore
| | - Subhi Marwari
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Rajamani Lakshminarayanan
- Singapore Eye Research Institute, Singapore; Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Francis Chee Kuan Tan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Charles William Johannes
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Brian William Dymock
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Anders Poulsen
- Department of Medicinal Chemistry, Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Deron Raymond Herr
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Gavin Stewart Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore; Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, Singapore.
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Kumar JR, Rajkumar R, Jayakody T, Marwari S, Hong JM, Ma S, Gundlach AL, Lai MKP, Dawe GS. Relaxin' the brain: a case for targeting the nucleus incertus network and relaxin-3/RXFP3 system in neuropsychiatric disorders. Br J Pharmacol 2016; 174:1061-1076. [PMID: 27597467 PMCID: PMC5406295 DOI: 10.1111/bph.13564] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 07/15/2016] [Indexed: 12/14/2022] Open
Abstract
Relaxin‐3 has been proposed to modulate emotional–behavioural functions such as arousal and behavioural activation, appetite regulation, stress responses, anxiety, memory, sleep and circadian rhythm. The nucleus incertus (NI), in the midline tegmentum close to the fourth ventricle, projects widely throughout the brain and is the primary site of relaxin‐3 neurons. Over recent years, a number of preclinical studies have explored the function of the NI and relaxin‐3 signalling, including reports of mRNA or peptide expression changes in the NI in response to behavioural or pharmacological manipulations, effects of lesions or electrical or pharmacological manipulations of the NI, effects of central microinfusions of relaxin‐3 or related agonist or antagonist ligands on physiology and behaviour, and the impact of relaxin‐3 gene deletion or knockdown. Although these individual studies reveal facets of the likely functional relevance of the NI and relaxin‐3 systems for human physiology and behaviour, the differences observed in responses between species (e.g. rat vs. mouse), the clearly identified heterogeneity of NI neurons and procedural differences between laboratories are some of the factors that have prevented a precise understanding of their function. This review aims to draw attention to the current preclinical evidence available that suggests the relevance of the NI/relaxin‐3 system to the pathology and/or symptoms of certain neuropsychiatric disorders and to provide cognizant directions for future research to effectively and efficiently uncover its therapeutic potential. Linked Articles This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc
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Affiliation(s)
- Jigna Rajesh Kumar
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Singapore.,NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore
| | - Ramamoorthy Rajkumar
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Singapore
| | - Tharindunee Jayakody
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Singapore
| | - Subhi Marwari
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Singapore
| | - Jia Mei Hong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Singapore.,NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore
| | - Sherie Ma
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Gavin S Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Singapore.,NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore
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Hojo K, Hossain MA, Tailhades J, Shabanpoor F, Wong LLL, Ong-Pålsson EEK, Kastman HE, Ma S, Gundlach AL, Rosengren KJ, Wade JD, Bathgate RAD. Development of a Single-Chain Peptide Agonist of the Relaxin-3 Receptor Using Hydrocarbon Stapling. J Med Chem 2016; 59:7445-56. [PMID: 27464307 DOI: 10.1021/acs.jmedchem.6b00265] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Structure-activity studies of the insulin superfamily member, relaxin-3, have shown that its G protein-coupled receptor (RXFP3) binding site is contained within its central B-chain α-helix and this helical structure is essential for receptor activation. We sought to develop a single B-chain mimetic that retained agonist activity. This was achieved by use of solid phase peptide synthesis together with on-resin ruthenium-catalyzed ring closure metathesis of a pair of judiciously placed i,i+4 α-methyl, α-alkenyl amino acids. The resulting hydrocarbon stapled peptide was shown by solution NMR spectroscopy to mimic the native helical conformation of relaxin-3 and to possess potent RXFP3 receptor binding and activation. Alternative stapling procedures were unsuccessful, highlighting the critical need to carefully consider both the peptide sequence and stapling methodology for optimal outcomes. Our result is the first successful minimization of an insulin-like peptide to a single-chain α-helical peptide agonist which will facilitate study of the function of relaxin-3.
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Affiliation(s)
- Keiko Hojo
- Faculty of Pharmaceutical Sciences and Cooperative Research Center of Life Sciences, Kobe Gakuin University , Chuo-ku, Kobe 650-8586, Japan
| | - Mohammed Akhter Hossain
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia.,School of Chemistry, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Julien Tailhades
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Fazel Shabanpoor
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia.,School of Chemistry, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Lilian L L Wong
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Emma E K Ong-Pålsson
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Hanna E Kastman
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Sherie Ma
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Andrew L Gundlach
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia.,Department of Anatomy and Neuroscience, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - K Johan Rosengren
- School of Biomedical Sciences, The University of Queensland , Brisbane, Queensland 4072, Australia
| | - John D Wade
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia.,School of Chemistry, University of Melbourne , Melbourne, Victoria 3052, Australia
| | - Ross A D Bathgate
- Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne , Melbourne, Victoria 3052, Australia
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Calvez J, de Ávila C, Timofeeva E. Sex-specific effects of relaxin-3 on food intake and body weight gain. Br J Pharmacol 2016; 174:1049-1060. [PMID: 27245781 DOI: 10.1111/bph.13530] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 01/06/2023] Open
Abstract
Relaxin-3 (RLN3) is a neuropeptide that is strongly expressed in the pontine nucleus incertus (NI) and binds with high affinity to its cognate receptor RXFP3. Central administration of RLN3 in rats increases food intake and adiposity. In humans, RLN3 polymorphism has been associated with obesity and hypercholesterolaemia. Emerging evidence suggests that the effects of RLN3 may have sex-specific aspects. Thus, the RLN3 knockout female but not male mice are hypoactive. RLN3 produced stronger orexigenic and obesogenic effects in female rats compared with male rats. In addition, female rats demonstrated higher sensitivity to lower doses of RLN3. Repeated cycles of food restriction and stress were accompanied by an increase in RLN3 expression and hyperphagia in female but not in male rats. Furthermore, stress-induced binge eating in female rats was blocked by an RXFP3 receptor antagonist. RLN3 increased the expression of corticotropin releasing factor in the paraventricular hypothalamic nucleus in male but not in female rats. Conversely, in female rats, RLN3 increased the expression of orexin in the lateral hypothalamus. There is evidence that orexin directly activates the RLN3 neurons in the NI. The positive reinforcement of the RLN3 effects by orexin may intensify behavioural activation and feeding in females. Sex-specific effects of RLN3 may also depend on differential expression of RXFP3 receptors in the brain. Given the higher sensitivity of females to the orexigenic effects of RLN3 and the stress-induced activation of RLN3, the overall data suggest a possible role for RLN3 in eating disorders that show a higher propensity in women. LINKED ARTICLES This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.
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Affiliation(s)
- Juliane Calvez
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Camila de Ávila
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Elena Timofeeva
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada
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Hu MJ, Shao XX, Wang JH, Wei D, Guo YQ, Liu YL, Xu ZG, Guo ZY. Mechanism for insulin-like peptide 5 distinguishing the homologous relaxin family peptide receptor 3 and 4. Sci Rep 2016; 6:29648. [PMID: 27404393 PMCID: PMC4939597 DOI: 10.1038/srep29648] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 06/07/2016] [Indexed: 12/11/2022] Open
Abstract
The relaxin family peptides play a variety of biological functions by activating four G protein-coupled receptors, RXFP1-4. Among them, insulin-like peptide 5 (INSL5) and relaxin-3 share the highest sequence homology, but they have distinct receptor preference: INSL5 can activate RXFP4 only, while relaxin-3 can activate RXFP3, RXFP4, and RXFP1. Previous studies suggest that the A-chain is responsible for their different selectivity for RXFP1. However, the mechanism by which INSL5 distinguishes the homologous RXFP4 and RXFP3 remains unknown. In the present work, we chemically evolved INSL5 in vitro to a strong agonist of both RXFP4 and RXFP3 through replacement of its five B-chain residues with the corresponding residues of relaxin-3. We identified four determinants (B2Glu, B9Leu, B17Tyr, and a rigid B-chain C-terminus) on INSL5 that are responsible for its inactivity at RXFP3. In reverse experiments, we grafted these determinants onto a chimeric R3/I5 peptide, which contains the B-chain of relaxin-3 and the A-chain of INSL5, and retains full activation potency at RXFP3 and RXFP4. All resultant R3/I5 mutants retained high activation potency towards RXFP4, but most displayed significantly decreased or even abolished activation potency towards RXFP3, confirming the role of these four INSL5 determinants in distinguishing RXFP4 from RXFP3.
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Affiliation(s)
- Meng-Jun Hu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jia-Hui Wang
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Dian Wei
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yu-Qi Guo
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
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Kastman HE, Blasiak A, Walker L, Siwiec M, Krstew EV, Gundlach AL, Lawrence AJ. Nucleus incertus Orexin2 receptors mediate alcohol seeking in rats. Neuropharmacology 2016; 110:82-91. [PMID: 27395787 DOI: 10.1016/j.neuropharm.2016.07.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/28/2016] [Accepted: 07/05/2016] [Indexed: 11/29/2022]
Abstract
Alcoholism is a chronic relapsing disorder and a major global health problem. Stress is a key precipitant of relapse in human alcoholics and in animal models of alcohol seeking. The brainstem nucleus incertus (NI) contains a population of relaxin-3 neurons that are highly responsive to psychological stressors; and the ascending NI relaxin-3/RXFP3 signalling system is implicated in stress-induced reinstatement of alcohol seeking. The NI receives orexinergic innervation and expresses orexin1 (OX1) and orexin2 (OX2) receptor mRNA. In alcohol-preferring (iP) rats, we examined the impact of yohimbine-induced reinstatement of alcohol seeking on orexin neuronal activation, and the effect of bilateral injections into NI of the OX1 receptor antagonist, SB-334867 (n = 16) or the OX2 receptor antagonist, TCS-OX2-29 (n = 8) on stress-induced reinstatement of alcohol seeking. We also assessed the effects of orexin-A on NI neuronal activity and the involvement of OX1 and OX2 receptors using whole cell patch-clamp recordings in rat brain slices. Yohimbine-induced reinstatement of alcohol seeking activated orexin neurons. Bilateral NI injections of TCS-OX2-29 attenuated yohimbine-induced reinstatement of alcohol seeking. In contrast, intra-NI injection of SB-334867 had no significant effect. In line with these data, orexin-A (600 nM) depolarized a majority of NI neurons recorded in coronal brain slices (18/28 cells), effects prevented by bath application of TCS-OX2-29 (10 μM), but not SB-334867 (10 μM). These data suggest an excitatory orexinergic input to NI contributes to yohimbine-induced reinstatement of alcohol seeking, predominantly via OX2 receptor signalling.
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Affiliation(s)
- Hanna E Kastman
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Leigh Walker
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Marcin Siwiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Elena V Krstew
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Andrew J Lawrence
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia.
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Identification of hydrophobic interactions between relaxin-3 and its receptor RXFP3: implication for a conformational change in the B-chain C-terminus during receptor binding. Amino Acids 2016; 48:2227-36. [PMID: 27193232 DOI: 10.1007/s00726-016-2260-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/11/2016] [Indexed: 01/05/2023]
Abstract
Relaxin-3 is an insulin/relaxin superfamily neuropeptide implicated in the regulation of food intake and stress response via activation of the G protein-coupled receptor RXFP3. Their electrostatic interactions have been recently identified, and involves three positively charged B-chain residues (B12Arg, B16Arg, and B26Arg) of relaxin-3 and two negatively charged residues (Glu141 and Asp145) in a highly conserved ExxxD motif at the extracellular end of the second transmembrane domain of RXFP3. To investigate their hydrophobic interactions, in the present work we deleted the highly conserved B-chain C-terminal B27Trp residue of relaxin-3, and mutated four highly conserved aromatic residues (Phe137, Trp138, Phe146, and Trp148) around the ExxxD motif of RXFP3. The resultant [∆B27W]relaxin-3 exhibited approximately tenfold lower binding potency and ~1000-fold lower activation potency towards wild-type RXFP3, confirming its importance for relaxin-3 function. Although the RXFP3 mutants could be normally trafficked to cell membrane, they had quite different activities. [F137A]RXFP3 could normally distinguish wild-type relaxin-3 and [∆B27W]relaxin-3 in binding and activation assays, whereas [W138A]RXFP3 lost most of this capability, suggesting that the Trp138 residue of RXFP3 forms hydrophobic interactions with the B27Trp residue of relaxin-3. The hydrophobic Trp138 residue and the formerly identified negatively charged Glu141 and Asp145 residues in the highly conserved WxxExxxD motif may thus form a functional surface that is important for interaction with relaxin-3. We hypothesize that the relaxin-3 B-chain C-terminus changes from the original folding-back conformation to an extended conformation during binding with RXFP3, to allow its B27Trp and B26Arg residues to interact with the Trp138 and Glu141 residues of RXFP3, respectively.
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Patil NA, Hughes RA, Rosengren KJ, Kocan M, Ang SY, Tailhades J, Separovic F, Summers RJ, Grosse J, Wade JD, Bathgate RAD, Hossain MA. Engineering of a Novel Simplified Human Insulin-Like Peptide 5 Agonist. J Med Chem 2016; 59:2118-25. [PMID: 26824523 DOI: 10.1021/acs.jmedchem.5b01786] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Insulin-like peptide 5 (INSL5) has recently been discovered as only the second orexigenic gut hormone after ghrelin. As we have previously reported, INSL5 is extremely difficult to assemble and oxidize into its two-chain three-disulfide structure. The focus of this study was to generate structure-activity relationships (SARs) of INSL5 and use it to develop a potent and simpler INSL5 mimetic with RXFP4 agonist activity. A series of human and mouse INSL5 (hINSL5/mINSL5) analogues were designed and chemically synthesized, resulting in a chimeric INSL5 analogue exhibiting more than 10-fold higher potency (0.35 nM) at human RXFP4 compared with native hINSL5 (4.57 nM). The SAR study also identified a key residue (K(A15)) in the A-chain of mINSL5 that contributes to improved RXFP4 affinity and potency of mINSL5 compared with hINSL5. This knowledge ultimately led us to engineer a minimized hINSL5 mimetic agonist that retains native hINSL5-like RXFP4 affinity and potency at human RXFP4. This minimized analogue was synthesized in 17.5-fold higher yield and in less time compared with hINSL5.
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Affiliation(s)
| | | | - K Johan Rosengren
- School of Biomedical Sciences, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Martina Kocan
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, VIC 3052, Australia
| | - Sheng Yu Ang
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, VIC 3052, Australia
| | | | | | - Roger J Summers
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, VIC 3052, Australia
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Wu QP, Zhang L, Shao XX, Wang JH, Gao Y, Xu ZG, Liu YL, Guo ZY. Application of the novel bioluminescent ligand-receptor binding assay to relaxin-RXFP1 system for interaction studies. Amino Acids 2016; 48:1099-1107. [PMID: 26767372 DOI: 10.1007/s00726-015-2146-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/27/2015] [Indexed: 10/22/2022]
Abstract
Relaxin is a prototype of the relaxin family peptide hormones and plays important biological functions by binding and activating the G protein-coupled receptor RXFP1. To study their interactions, in the present work, we applied the newly developed bioluminescent ligand-receptor binding assay to the relaxin-RXFP1 system. First, a fully active easily labeled relaxin, in which three Lys residues of human relaxin-2 were replaced by Arg, was prepared through overexpression of a single-chain precursor in Pichia pastoris and in vitro enzymatic maturation. Thereafter, the B-chain N-terminus of the easily labeled relaxin was chemically cross-linked with a C-terminal cysteine residue of an engineered NanoLuc through a disulfide linkage. Receptor-binding assays demonstrated that the NanoLuc-conjugated relaxin retained high binding affinity with the receptor RXFP1 (K d = 1.11 ± 0.08 nM, n = 3) and was able to sensitively monitor binding of a variety of ligands with RXFP1. Using the novel bioluminescent binding assay, we demonstrated that three highly conserved B-chain Arg residues of relaxin-3 had distinct contributions to binding of the receptor RXFP1. In summary, our present work provides a novel bioluminescent ligand-receptor binding assay for the relaxin-RXFP1 system to facilitate their interaction studies, such as characterization of relaxin analogues or screening novel agonists or antagonists of RXFP1.
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Affiliation(s)
- Qing-Ping Wu
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Lei Zhang
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jia-Hui Wang
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yu Gao
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China.
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China.
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Halls ML, Bathgate RAD, Sutton SW, Dschietzig TB, Summers RJ. International Union of Basic and Clinical Pharmacology. XCV. Recent advances in the understanding of the pharmacology and biological roles of relaxin family peptide receptors 1-4, the receptors for relaxin family peptides. Pharmacol Rev 2015; 67:389-440. [PMID: 25761609 DOI: 10.1124/pr.114.009472] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Relaxin, insulin-like peptide 3 (INSL3), relaxin-3, and INSL5 are the cognate ligands for the relaxin family peptide (RXFP) receptors 1-4, respectively. RXFP1 activates pleiotropic signaling pathways including the signalosome protein complex that facilitates high-sensitivity signaling; coupling to Gα(s), Gα(i), and Gα(o) proteins; interaction with glucocorticoid receptors; and the formation of hetero-oligomers with distinctive pharmacological properties. In addition to relaxin-related ligands, RXFP1 is activated by Clq-tumor necrosis factor-related protein 8 and by small-molecular-weight agonists, such as ML290 [2-isopropoxy-N-(2-(3-(trifluoromethylsulfonyl)phenylcarbamoyl)phenyl)benzamide], that act allosterically. RXFP2 activates only the Gα(s)- and Gα(o)-coupled pathways. Relaxin-3 is primarily a neuropeptide, and its cognate receptor RXFP3 is a target for the treatment of depression, anxiety, and autism. A variety of peptide agonists, antagonists, biased agonists, and an allosteric modulator target RXFP3. Both RXFP3 and the related RXFP4 couple to Gα(i)/Gα(o) proteins. INSL5 has the properties of an incretin; it is secreted from the gut and is orexigenic. The expression of RXFP4 in gut, adipose tissue, and β-islets together with compromised glucose tolerance in INSL5 or RXFP4 knockout mice suggests a metabolic role. This review focuses on the many advances in our understanding of RXFP receptors in the last 5 years, their signal transduction mechanisms, the development of novel compounds that target RXFP1-4, the challenges facing the field, and current prospects for new therapeutics.
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Affiliation(s)
- Michelle L Halls
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (M.L.H., R.J.S.); Neuropeptides Division, Florey Institute of Neuroscience and Mental Health and Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia (R.A.D.B.); Neuroscience Drug Discovery, Janssen Research & Development, LLC, San Diego, California (S.W.S.); Immundiagnostik AG, Bensheim, Germany (T.B.D.); and Charité-University Medicine Berlin, Campus Mitte, Medical Clinic for Cardiology and Angiology, Berlin, Germany (T.B.D.)
| | - Ross A D Bathgate
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (M.L.H., R.J.S.); Neuropeptides Division, Florey Institute of Neuroscience and Mental Health and Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia (R.A.D.B.); Neuroscience Drug Discovery, Janssen Research & Development, LLC, San Diego, California (S.W.S.); Immundiagnostik AG, Bensheim, Germany (T.B.D.); and Charité-University Medicine Berlin, Campus Mitte, Medical Clinic for Cardiology and Angiology, Berlin, Germany (T.B.D.)
| | - Steve W Sutton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (M.L.H., R.J.S.); Neuropeptides Division, Florey Institute of Neuroscience and Mental Health and Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia (R.A.D.B.); Neuroscience Drug Discovery, Janssen Research & Development, LLC, San Diego, California (S.W.S.); Immundiagnostik AG, Bensheim, Germany (T.B.D.); and Charité-University Medicine Berlin, Campus Mitte, Medical Clinic for Cardiology and Angiology, Berlin, Germany (T.B.D.)
| | - Thomas B Dschietzig
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (M.L.H., R.J.S.); Neuropeptides Division, Florey Institute of Neuroscience and Mental Health and Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia (R.A.D.B.); Neuroscience Drug Discovery, Janssen Research & Development, LLC, San Diego, California (S.W.S.); Immundiagnostik AG, Bensheim, Germany (T.B.D.); and Charité-University Medicine Berlin, Campus Mitte, Medical Clinic for Cardiology and Angiology, Berlin, Germany (T.B.D.)
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (M.L.H., R.J.S.); Neuropeptides Division, Florey Institute of Neuroscience and Mental Health and Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia (R.A.D.B.); Neuroscience Drug Discovery, Janssen Research & Development, LLC, San Diego, California (S.W.S.); Immundiagnostik AG, Bensheim, Germany (T.B.D.); and Charité-University Medicine Berlin, Campus Mitte, Medical Clinic for Cardiology and Angiology, Berlin, Germany (T.B.D.)
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Kocan M, Ang SY, Summers RJ. Orthosteric, Allosteric and Biased Signalling at the Relaxin-3 Receptor RXFP3. Neurochem Res 2015; 41:610-9. [PMID: 26294284 DOI: 10.1007/s11064-015-1701-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 08/12/2015] [Accepted: 08/13/2015] [Indexed: 11/29/2022]
Abstract
Relaxin-3 is a neuropeptide that has roles in stress, memory and appetite regulation. The peptide acts on its cognate receptor RXFP3 to induce coupling to inhibitory G proteins to inhibit adenylyl cyclase and activate MAP-kinases such as ERK1/2, p38MAPK and JNK. Other relaxin family peptides can activate the receptor to produce alternative patterns of signalling and there is an allosteric modulator 135PAM1 that displays probe-selectivity. There are now a variety of selective peptide agonists and antagonists that will assist in the determination of the physiological roles of the relaxin-RXFP3 system and its potential as a drug target.
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Affiliation(s)
- Martina Kocan
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Sheng Yu Ang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
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Blasiak A, Siwiec M, Grabowiecka A, Blasiak T, Czerw A, Blasiak E, Kania A, Rajfur Z, Lewandowski MH, Gundlach AL. Excitatory orexinergic innervation of rat nucleus incertus--Implications for ascending arousal, motivation and feeding control. Neuropharmacology 2015; 99:432-47. [PMID: 26265304 DOI: 10.1016/j.neuropharm.2015.08.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 07/17/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
Orexin/hypocretin peptides play a central role in the integrated control of feeding/reward and behavioural activation, principally via interactions with other neural systems. A brainstem area involved in behavioural activation is the nucleus incertus (NI), located in the posterior ventromedial central grey. Several studies have implicated NI in control of arousal/stress and reward/feeding responses. Orexin receptor mRNA expression identifies NI as a putative target of orexin modulation. Therefore, in this study we performed neural tract-tracing and immunofluorescence staining to characterise the orexinergic innervation of NI. Our results indicate a convergent innervation of the NI area by different orexin neuron populations, with an abundance of orexin-A-containing axons making putative synaptic contacts with relaxin-3-positive NI neurons. The influence of orexin-A on NI neuron activity was investigated using patch-clamp recordings. Orexin-A depolarised the majority (64%) of recorded neurons and this effect was maintained in the presence of tetrodotoxin and glutamate and GABA receptor antagonists, indicating a likely postsynaptic action. Voltage-clamp experiments revealed that in 'type I' NI neurons comprising relaxin-3-positive cells, orexin-A acted via L-type calcium channels, whereas in 'type II' relaxin-3-negative neurons, activation of a sodium/calcium exchanger was involved. A majority of the orexin-A sensitive neurons tested for the presence of orexin receptor mRNA, were OX2 mRNA-positive. Immunohistochemical staining for putative orexin receptors on NI neurons, confirmed stronger expression of OX2 than OX1 receptors. Our data demonstrate a strong influence of orexin-A on NI neurons, consistent with an important role for this hypothalamic/tegmental circuit in the regulation of arousal/vigilance and motivated behaviours.
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Affiliation(s)
- Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland.
| | - Marcin Siwiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Agnieszka Grabowiecka
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Tomasz Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Anna Czerw
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Ewa Blasiak
- Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Alan Kania
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Zenon Rajfur
- Faculty of Physics, Astronomy and Applied Computer Science, Institute of Physics, Jagiellonian University, 30-348 Krakow, Poland
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University, 30-387 Krakow, Poland
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, Victoria 3010, Australia.
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Ma S, Gundlach AL. Ascending control of arousal and motivation: role of nucleus incertus and its peptide neuromodulators in behavioural responses to stress. J Neuroendocrinol 2015; 27:457-67. [PMID: 25612218 DOI: 10.1111/jne.12259] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 02/06/2023]
Abstract
Arousal is a process that involves the activation of ascending neural pathways originating in the rostral pons that project to the forebrain through the midbrain reticular formation to promote the activation of key cortical, thalamic, hypothalamic and limbic centres. Established modulators of arousal include the cholinergic, serotonergic, noradrenergic and dopaminergic networks originating in the pons and midbrain. Recent data indicate that a population of largely GABAergic projection neurones located in the nucleus incertus (NI) are also involved in arousal and motivational processes. The NI has prominent efferent connections with distinct hypothalamic, amygdalar and thalamic nuclei, in addition to dense projections to key brain regions associated with the generation and pacing of hippocampal activity. The NI receives strong inputs from the prefrontal cortex, lateral habenula and the interpeduncular and median raphe nuclei, suggesting it is highly integrated in circuits regulating higher cognitive behaviours (hippocampal theta rhythm) and emotion. Anatomical and functional studies have revealed that the NI is a rich source of multiple peptide neuromodulators, including relaxin-3, and may mediate extra-hypothalamic effects of the stress hormone corticotrophin-releasing factor, as well as other key modulators such as orexins and oxytocin. This review provides an overview of earlier studies and highlights more recent research that implicates this neural network in the integration of arousal and motivated behaviours and has begun to identify the associated mechanisms. Future research that should help to better clarify the connectivity and function of the NI in major experimental species and humans is also discussed.
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Affiliation(s)
- S Ma
- Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - A L Gundlach
- Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, VIC, Australia
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Haugaard-Kedström LM, Hossain MA, Daly NL, Bathgate RAD, Rinderknecht E, Wade JD, Craik DJ, Rosengren KJ. Solution structure, aggregation behavior, and flexibility of human relaxin-2. ACS Chem Biol 2015; 10:891-900. [PMID: 25547165 DOI: 10.1021/cb500918v] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Relaxin is a member of the relaxin/insulin peptide hormone superfamily and is characterized by a two-chain structure constrained by three disulfide bonds. Relaxin is a pleiotropic hormone and involved in a number of physiological and pathogenic processes, including collagen and cardiovascular regulation and tissue remodelling during pregnancy and cancer. Crystallographic and ultracentrifugation experiments have revealed that the human form of relaxin, H2 relaxin, self-associates into dimers, but the significance of this is poorly understood. Here, we present the NMR structure of a monomeric, amidated form of H2 relaxin and compare its features and behavior in solution to those of native H2 relaxin. The overall structure of H2 relaxin is retained in the monomeric form. H2 relaxin amide is fully active at the relaxin receptor RXFP1 and thus dimerization is not required for biological activity. Analysis of NMR chemical shifts and relaxation parameters identified internal motion in H2 relaxin at the pico-nanosecond and milli-microsecond time scales, which is commonly seen in other relaxin and insulin peptides and might be related to function.
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Affiliation(s)
| | | | - Norelle L. Daly
- Centre for
Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Cairns, Queensland 4878, Australia
| | | | - Ernst Rinderknecht
- Corthera, c/o
Novartis Corporation, San Carlos, California 94070, United States
| | | | | | - K. Johan Rosengren
- School
of Natural Sciences, Linnaeus University, SE-391 82 Kalmar, Sweden
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Haugaard-Kedström LM, Wong LLL, Bathgate RAD, Rosengren KJ. Synthesis and pharmacological characterization of a europium-labelled single-chain antagonist for binding studies of the relaxin-3 receptor RXFP3. Amino Acids 2015; 47:1267-71. [DOI: 10.1007/s00726-015-1961-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/07/2015] [Indexed: 10/23/2022]
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