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Wu H, Praveen P, Handley TNG, Chandrashekar C, Cummins SF, Bathgate RAD, Hossain MA. Total Chemical Synthesis of Aggregation-Prone Disulfide-Rich Starfish Peptides. Chemistry 2024; 30:e202400933. [PMID: 38609334 DOI: 10.1002/chem.202400933] [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: 03/06/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/14/2024]
Abstract
A relaxin-like gonad-stimulating peptide (RGP), Aso-RGP, featuring six cysteine residues, was identified in the Crown-of-Thorns Starfish (COTS, Acanthaster cf. solaris) and initially produced through recombinant yeast expression. This method yielded a single-chain peptide with an uncleaved C-peptide (His Tag) and suboptimal purity. Our objective was to chemically synthesize Aso-RGP in its mature form, comprising two chains (A and B) and three disulfide bridges, omitting the C-peptide. Furthermore, we aimed to synthesize a newly identified relaxin-like peptide, Aso-RLP2, from COTS, which had not been previously synthesized. This paper reports the first total chemical synthesis of Aso-RGP and Aso-RLP2. Aso-RGP synthesis proceeded without major issues, whereas the A-chain of Aso-RLP2, in its reduced and unfolded state with two free thiols, presented considerable challenges. These were initially marked by "messy" RP-HPLC profiles, typically indicative of synthesis failure. Surprisingly, oxidizing the A-chain significantly improved the RP-HPLC profile, revealing the main issue was not synthesis failure but the peptide's aggregation tendency, which initially obscured analysis. This discovery highlights the critical need to account for aggregation in peptide synthesis and analysis. Ultimately, our efforts led to the successful synthesis of both peptides with purities exceeding 95 %.
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Affiliation(s)
- Hongkang Wu
- The Florey, The University of Melbourne, Victoria, Australia
| | - Praveen Praveen
- The Florey, The University of Melbourne, Victoria, Australia
| | | | | | - Scott F Cummins
- Centre for Bioinnovation, University of the Sunshine Coast, Queensland, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Queensland, Australia
| | - Ross A D Bathgate
- The Florey, The University of Melbourne, Victoria, Australia
- Department of Biochemistry and Pharmacology, The University of Melbourne, Victoria, Australia
| | - Mohammed Akhter Hossain
- The Florey, The University of Melbourne, Victoria, Australia
- School of Chemistry, The University of Melbourne, Victoria, Australia
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2
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Wu H, Hoare BL, Handley TNG, Akhter Hossain M, Bathgate RAD. Development of a synthetic relaxin-3/INSL5 chimeric peptide ligand for NanoBiT complementation binding assays. Biochem Pharmacol 2024; 224:116238. [PMID: 38677442 DOI: 10.1016/j.bcp.2024.116238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/09/2024] [Accepted: 04/25/2024] [Indexed: 04/29/2024]
Abstract
INSL5 and relaxin-3 are relaxin family peptides with important roles in gut and brain function, respectively. They mediate their actions through the class A GPCRs RXFP4 and RXFP3. RXFP4 has been proposed to be a therapeutic target for colon motility disorders whereas RXFP3 targeting could be effective for neurological conditions such as anxiety. Validation of these targets has been limited by the lack of specific ligands and the availability of robust ligand-binding assays for their development. In this study, we have utilized NanoBiT complementation to develop a SmBiT-conjugated tracer for use with LgBiT-fused RXFP3 and RXFP4. The low affinity between LgBiT:SmBiT should result in a low non-specific luminescence signal and enable the quantification of binding without the tedious separation of non-bound ligands. We used solid-phase peptide synthesis to produce a SmBiT-labelled RXFP3/4 agonist, R3/I5, where SmBiT was conjugated to the B-chain N-terminus via a PEG12 linker. Both SmBiT-R3/I5 and R3/I5 were synthesized and purified in high purity and yield. Stable HEK293T cell lines expressing LgBiT-RXFP3 and LgBiT-RXFP4 were produced and demonstrated normal signaling in response to the synthetic R3/I5 peptide. Binding was first characterized in whole-cell binding kinetic assays validating that the SmBiT-R3/I5 bound to both cell lines with nanomolar affinity with minimal non-specific binding without bound and free SmBiT-R3/I5 separation. We then optimized membrane binding assays, demonstrating easy and robust analysis of both saturation and competition binding from frozen membranes. These assays therefore provide an appropriate rigorous binding assay for the high-throughput analysis of RXFP3 and RXFP4 ligands.
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Affiliation(s)
- Hongkang Wu
- The Florey, University of Melbourne, Victoria, Australia
| | | | | | - Mohammed Akhter Hossain
- The Florey, University of Melbourne, Victoria, Australia; School of Chemistry, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
| | - Ross A D Bathgate
- The Florey, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
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3
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Berger GK, Rockov ZA, Byrne C, Trentacosta NE, Stone MA. The role of relaxin in anterior cruciate ligament injuries: a systematic review. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY & TRAUMATOLOGY : ORTHOPEDIE TRAUMATOLOGIE 2023; 33:3319-3326. [PMID: 37300589 DOI: 10.1007/s00590-023-03618-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 06/04/2023] [Indexed: 06/12/2023]
Abstract
OBJECTIVE Anterior cruciate ligament (ACL) tears are exceedingly common among the athletic population and are seen with higher incidence in females. Observational studies have noted peak ACL tear rates in the luteal phase of the menstrual cycle, a time in which the hormone relaxin peaks in serum concentration. METHODS A systematic review of the literature was performed. Inclusion criteria specified all prospective and retrospective studies which included the role of relaxin in the pathogenesis of ACL tears. RESULTS Six studies met inclusion criteria yielding 189 subjects from clinical studies and 51 in vitro samples. Included studies found that ACL samples exhibit selective relaxin binding. When pre-treated with estrogen prior to relaxin exposure, female ACL tissue samples exhibit increased expression of collagen degrading receptors. CONCLUSION Relaxin displays binding specificity to the female ACL and increased serum concentrations are correlated with increased ACL tear rates in female athletes. Further research is needed in this area. LEVEL OF EVIDENCE V.
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Affiliation(s)
- Garrett K Berger
- Department of Orthopaedic Surgery, University of California-San Diego, San Diego, CA, 92037, USA.
| | - Zachary A Rockov
- Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Connor Byrne
- Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Natasha E Trentacosta
- Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Michael A Stone
- Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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4
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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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5
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Mita M, Feng Y, Piñon-Gonzalez VM, Elphick MR, Katayama H. Gonadotropic activity of a second relaxin-type peptide in starfish. Gen Comp Endocrinol 2023; 343:114369. [PMID: 37611673 DOI: 10.1016/j.ygcen.2023.114369] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/14/2023] [Accepted: 08/20/2023] [Indexed: 08/25/2023]
Abstract
In starfish, a relaxin-like gonad-stimulating peptide (RGP) acts as a gonadotropin that triggers gamete maturation and spawning. In common with other relaxin/insulin superfamily peptides, RGP consists of an A- and a B-chain, with cross-linkages mediated by one intra- and two inter-chain disulfide bonds. In this study, a second relaxin-like peptide (RLP2) was identified in starfish species belonging to the orders Valvatida, Paxillosida, and Forcipulatida. Like RGP, RLP2 precursors comprise a signal peptide and a C-peptide in addition to the A- and B-chains. However, a unique cysteine motif [CC-(3X)-C-(10X)-C] is present in the A-chain of RLP2, which contrasts with the cysteine motif in other members of the relaxin/insulin superfamily [CC-(3X)-C-(8X)-C]. Importantly, in vitro pharmacological tests revealed that Patiria pectinifera RLP2 (Ppe-RLP2) and Asterias rubens RLP2 (Aru-RLP2) trigger shedding of mature eggs from ovaries of P. pectinifera and A. rubens, respectively. Furthermore, the potencies of Ppe-RLP2 and Aru-RLP2 as gonadotropic peptides were similar to those of Ppe-RGP and Aru-RGP, respectively, and the effect of RLP2 exhibited partial species-specificity. These findings indicate that two relaxin-type peptides regulate spawning in starfish and therefore we propose that RGP and RLP2 are renamed RGP1 and RGP2, respectively.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, 1-5-8, Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
| | - Yuling Feng
- Queen Mary University of London, School of Biological & Behavioural Sciences, Mile End Road, London E1 4NS, UK
| | - Victor M Piñon-Gonzalez
- Queen Mary University of London, School of Biological & Behavioural Sciences, Mile End Road, London E1 4NS, UK
| | - Maurice R Elphick
- Queen Mary University of London, School of Biological & Behavioural Sciences, Mile End Road, London E1 4NS, UK
| | - Hidekazu Katayama
- Department of Bioengineering, School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
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6
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Mita M. Relaxin-like Gonad-Stimulating Peptides in Asteroidea. Biomolecules 2023; 13:biom13050781. [PMID: 37238650 DOI: 10.3390/biom13050781] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Starfish relaxin-like gonad-stimulating peptide (RGP) is the first identified peptide hormone with gonadotropin-like activity in invertebrates. RGP is a heterodimeric peptide, comprising A and B chains with disulfide cross-linkages. Although RGP had been named a gonad-stimulating substance (GSS), the purified peptide is a member of relaxin-type peptide family. Thus, GSS was renamed as RGP. The cDNA of RGP encodes not only the A and B chains, but also signal and C-peptides. After the rgp gene is translated as a precursor, mature RGP is produced by eliminating the signal and C-peptides. Hitherto, twenty-four RGP orthologs have been identified or predicted from starfish in the orders Valvatida, Forcipulatida, Paxillosida, Spinulosida, and Velatida. The molecular evolution of the RGP family is in good accordance with the phylogenetic taxonomy in Asteroidea. Recently, another relaxin-like peptide with gonadotropin-like activity, RLP2, was found in starfish. RGP is mainly present in the radial nerve cords and circumoral nerve rings, but also in the arm tips, the gonoducts, and the coelomocytes. RGP acts on ovarian follicle cells and testicular interstitial cells to induce the production of 1-methyladenine (1-MeAde), a starfish maturation-inducing hormone. RGP-induced 1-MeAde production is accompanied by an increase in intracellular cyclic AMP levels. This suggests that the receptor for RGP (RGPR) is a G protein-coupled receptor (GPCR). Two types of GPCRs, RGPR1 and RGPR2, have been postulated as candidates. Furthermore, 1-MeAde produced by RGP not only induces oocyte maturation, but also induces gamete shedding, possibly by stimulating the secretion of acetylcholine in the ovaries and testes. Thus, RGP plays an important role in starfish reproduction, but its secretion mechanism is still unknown. It has also been revealed that RGP is found in the peripheral adhesive papillae of the brachiolaria arms. However, gonads are not developed in the larvae before metamorphosis. It may be possible to discover new physiological functions of RGP other than gonadotropin-like activity.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, Hatanodai 8-5-1, Shinagawa-ku, Tokyo 142-8555, Japan
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7
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Praveen P, Wang C, Handley TNG, Wu H, Samuel CS, Bathgate RAD, Hossain MA. A Lipidated Single-B-Chain Derivative of Relaxin Exhibits Improved In Vitro Serum Stability without Altering Activity. Int J Mol Sci 2023; 24:ijms24076616. [PMID: 37047588 PMCID: PMC10094921 DOI: 10.3390/ijms24076616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Human relaxin-2 (H2 relaxin) is therapeutically very important due to its strong anti-fibrotic, vasodilatory, and cardioprotective effects. Therefore, relaxin’s receptor, relaxin family peptide receptor 1 (RXFP1), is a potential target for the treatment of fibrosis and related disorders, including heart failure. H2 relaxin has a complex two-chain structure (A and B) and three disulfide bridges. Our laboratory has recently developed B7-33 peptide, a single-chain agonist based on the B-chain of H2 relaxin. However, the peptide B7-33 has a short circulation time in vitro in serum (t1/2 = ~6 min). In this study, we report structure-activity relationship studies on B7-33 utilizing different fatty-acid conjugations at different positions. We have shown that by fatty-acid conjugation with an appropriate spacer length, the in vitro half-life of B7-33 can be increased from 6 min to 60 min. In the future, the lead lipidated molecule will be studied in animal models to measure its PK/PD properties, which will lead to their pre-clinical applications.
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Affiliation(s)
- Praveen Praveen
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Chao Wang
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, VIC 3168, Australia
| | - Thomas N. G. Handley
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Hongkang Wu
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Chrishan S. Samuel
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, VIC 3168, Australia
| | - Ross A. D. Bathgate
- Department of Biochemistry and Pharmacology, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3010, Australia
| | - Mohammed Akhter Hossain
- Florey Department of Neuroscience and Mental, Florey Institute of Neuroscience and Mental Health, School of Chemistry, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC 3010, Australia
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8
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Lv C, Zheng H, Jiang B, Ren Q, Zhang J, Zhang X, Li J, Wang Y. Characterization of relaxin 3 and its receptors in chicken: Evidence for relaxin 3 acting as a novel pituitary hormone. Front Physiol 2022; 13:1010851. [DOI: 10.3389/fphys.2022.1010851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/12/2022] [Indexed: 11/09/2022] Open
Abstract
Mammalian relaxin (RLN) family peptides binding their receptors (RXFPs) play a variety of roles in many physiological processes, such as reproduction, stress, appetite regulation, and energy balance. In birds, although two relaxin family peptides (RLN3 and INSL5) and four receptors (RXFP1, RXFP2, RXFP2-like, and RXFP3) were predicated, their sequence features, signal properties, tissue distribution, and physiological functions remain largely unknown. In this study, using chickens as the experimental model, we cloned the cDNA of the cRLN3 gene and two receptor (cRXFP1 and cRXFP3) genes. Using cell-based luciferase reporter assays, we demonstrate that cRLN3 is able to activate both cRXFP1 and cRXFP3 for downstream signaling. cRXFP1, rather than cRXFP3, is a cognate receptor for cRLN3, which is different from the mammals. Tissue distribution analyses reveal that cRLN3 is highly expressed in the pituitary with lower abundance in the hypothalamus and ovary of female chicken, together with the detection that cRLN3 co-localizes with pituitary hormone genes LHB/FSHB/GRP/CART and its expression is tightly regulated by hypothalamic factors (GnRH and CRH) and sex steroid hormone (E2). The present study supports that cRLN3 may function as a novel pituitary hormone involving female reproduction.
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Blasiak A, Gugula A, Gundlach AL, Olucha-Bordonau FE, Aniello F, Donizetti A. Relaxin ligand/receptor systems in the developing teleost fish brain: Conserved features with mammals and a platform to address neuropeptide system functions. Front Mol Neurosci 2022; 15:984524. [PMID: 36277494 PMCID: PMC9580368 DOI: 10.3389/fnmol.2022.984524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/16/2022] [Indexed: 11/20/2022] Open
Abstract
The relaxins (RLNs) are a group of peptide hormone/neuromodulators that can regulate a wide range of physiological processes ranging from reproduction to brain function. All the family members have originated from a RLN3-like ancestor via different rounds of whole genome and gene specific duplications during vertebrate evolution. In mammals, including human, the divergence of the different family members and the emergence of new members led to the acquisition of specific functions for the various relaxin family peptide and associated receptor genes. In particular, in mammals, it was shown, that the role of RLN3 is correlated to the modulation of arousal, stress responses, emotion, social recognition, and other brain functions, positioning this gene/peptide as a potential therapeutic target for neuropsychiatric disorders. This review highlights the evolutionary conservation of relaxin family peptide and receptor gene expression and their associated brain neural circuits. In the zebrafish, the expression pattern of the different relaxin family members has specific features that are conserved in higher species, including a likely similar functional role for the ancestral RLN3-like gene. The use of different model organisms, particularly the zebrafish, to explore the diversification and conservation of relaxin family ligands and receptor systems, provides a relatively high-throughput platform to identify their specific conserved or differential neuromodulatory roles in higher species including human.
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Affiliation(s)
- Anna Blasiak
- Department of Neurophysiology and Chronobiology, Jagiellonian University, Krakow, Poland
| | - Anna Gugula
- Department of Neurophysiology and Chronobiology, Jagiellonian University, Krakow, Poland
| | - Andrew L. Gundlach
- Florey Department of Neuroscience and Mental Health, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, Australia
| | | | - Francesco Aniello
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Aldo Donizetti
- Department of Biology, University of Naples Federico II, Naples, Italy
- *Correspondence: Aldo Donizetti,
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Chen TY, Li X, Goobie GC, Hung CH, Hung TK, Hamilton K, Bahudhanapati H, Tan J, Kass DJ, Zhang Y. Identification of a distal RXFP1 gene enhancer with differential activity in fibrotic lung fibroblasts involving AP-1. PLoS One 2022; 16:e0254466. [PMID: 34972106 PMCID: PMC8719731 DOI: 10.1371/journal.pone.0254466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/13/2021] [Indexed: 12/29/2022] Open
Abstract
Relaxin/insulin-like family peptide receptor 1 (RXFP1) mediates relaxin’s antifibrotic effects and has reduced expression in the lung and skin of patients with fibrotic interstitial lung disease (fILD) including idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc). This may explain the failure of relaxin-based anti-fibrotic treatments in SSc, but the regulatory mechanisms controlling RXFP1 expression remain largely unknown. This study aimed to identify regulatory elements of RXFP1 that may function differentially in fibrotic fibroblasts. We identified and evaluated a distal regulatory region of RXFP1 in lung fibroblasts using a luciferase reporter system. Using serial deletions, an enhancer upregulating pGL3-promoter activity was localized to the distal region between -584 to -242bp from the distal transcription start site (TSS). This enhancer exhibited reduced activity in IPF and SSc lung fibroblasts. Bioinformatic analysis identified two clusters of activator protein 1 (AP-1) transcription factor binding sites within the enhancer. Site-directed mutagenesis of the binding sites confirmed that only one cluster reduced activity (-358 to -353 relative to distal TSS). Co-expression of FOS in lung fibroblasts further increased enhancer activity. In vitro complex formation with a labeled probe spanning the functional AP-1 site using nuclear proteins isolated from lung fibroblasts confirmed a specific DNA/protein complex formation. Application of antibodies against JUN and FOS resulted in the complex alteration, while antibodies to JUNB and FOSL1 did not. Analysis of AP-1 binding in 5 pairs of control and IPF lung fibroblasts detected positive binding more frequently in control fibroblasts. Expression of JUN and FOS was reduced and correlated positively with RXFP1 expression in IPF lungs. In conclusion, we identified a distal enhancer of RXFP1 with differential activity in fibrotic lung fibroblasts involving AP-1 transcription factors. Our study provides insight into RXFP1 downregulation in fILD and may support efforts to reevaluate relaxin-based therapeutics alongside upregulation of RXFP1 transcription.
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Affiliation(s)
- Ting-Yun Chen
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
- Institute of Allied Health Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Xiaoyun Li
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Gillian C. Goobie
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Medicine, Clinician Investigator Program, University of British Columbia, Vancouver, B.C., Canada
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Ching-Hsia Hung
- Institute of Allied Health Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Tin-Kan Hung
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Kyle Hamilton
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Harinath Bahudhanapati
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Jiangning Tan
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Daniel J. Kass
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Yingze Zhang
- Division of Pulmonary, Allergy and Critical Care Medicine and The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- * E-mail:
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Structural Insights into the Unique Modes of Relaxin-Binding and Tethered-Agonist Mediated Activation of RXFP1 and RXFP2. J Mol Biol 2021; 433:167217. [PMID: 34454945 DOI: 10.1016/j.jmb.2021.167217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/09/2021] [Accepted: 08/19/2021] [Indexed: 01/01/2023]
Abstract
Our poor understanding of the mechanism by which the peptide-hormone H2 relaxin activates its G protein coupled receptor, RXFP1 and the related receptor RXFP2, has hindered progress in its therapeutic development. Both receptors possess large ectodomains, which bind H2 relaxin, and contain an N-terminal LDLa module that is essential for receptor signaling and postulated to be a tethered agonist. Here, we show that a conserved motif (GDxxGWxxxF), C-terminal to the LDLa module, is critical for receptor activity. Importantly, this motif adopts different structures in RXFP1 and RXFP2, suggesting distinct activation mechanisms. For RXFP1, the motif is flexible, weakly associates with the LDLa module, and requires H2 relaxin binding to stabilize an active conformation. Conversely, the GDxxGWxxxF motif in RXFP2 is more closely associated with the LDLa module, forming an essential binding interface for H2 relaxin. These differences in the activation mechanism will aid drug development targeting these receptors.
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12
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Analgesic effect of central relaxin receptor activation on persistent inflammatory pain in mice: behavioral and neurochemical data. Pain Rep 2021; 6:e937. [PMID: 34159282 PMCID: PMC8213244 DOI: 10.1097/pr9.0000000000000937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/26/2021] [Accepted: 04/23/2021] [Indexed: 01/02/2023] Open
Abstract
Supplemental Digital Content is Available in the Text. Relaxin peptide analogues produce strong but transient analgesia in inflammatory pain in mouse. Relaxin and its RXFP1 receptor represent a new peptidergic system that modulates pain processing in the forebrain areas. Introduction: The relaxin peptide signaling system is involved in diverse physiological processes, but its possible roles in the brain, including nociception, are largely unexplored. Objective: In light of abundant expression of relaxin receptor (RXFP1) mRNA/protein in brain regions involved in pain processing, we investigated the effects of central RXFP1 activation on nociceptive behavior in a mouse model of inflammatory pain and examined the neurochemical phenotype and connectivity of relaxin and RXFP1 mRNA-positive neurons. Methods: Mice were injected with Complete Freund Adjuvant (CFA) into a hind paw. After 4 days, the RXFP1 agonist peptides, H2-relaxin or B7-33, ± the RXFP1 antagonist, B-R13/17K-H2, were injected into the lateral cerebral ventricle, and mechanical and thermal sensitivity were assessed at 30 to 120 minutes. Relaxin and RXFP1 mRNA in excitatory and inhibitory neurons were examined using multiplex, fluorescent in situ hybridization. Relaxin-containing neurons were detected using immunohistochemistry and their projections assessed using fluorogold retrograde tract-tracing. Results: Both H2-relaxin and B7-33 produced a strong, but transient, reduction in mechanical and thermal sensitivity of the CFA-injected hind paw alone, at 30 minutes postinjection. Notably, coinjection of B-R13/17K-H2 blocked mechanical, but not thermal, analgesia. In the claustrum, cingulate cortex, and subiculum, RXFP1 mRNA was expressed in excitatory neurons. Relaxin immunoreactivity was detected in neurons in forebrain and midbrain areas involved in pain processing and sending projections to the RXFP1-rich, claustrum and cingulate cortex. No changes were detected in CFA mice. Conclusion: Our study identified a previously unexplored peptidergic system that can control pain processing in the brain and produce analgesia.
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Heredia F, Volonté Y, Pereirinha J, Fernandez-Acosta M, Casimiro AP, Belém CG, Viegas F, Tanaka K, Menezes J, Arana M, Cardoso GA, Macedo A, Kotowicz M, Prado Spalm FH, Dibo MJ, Monfardini RD, Torres TT, Mendes CS, Garelli A, Gontijo AM. The steroid-hormone ecdysone coordinates parallel pupariation neuromotor and morphogenetic subprograms via epidermis-to-neuron Dilp8-Lgr3 signal induction. Nat Commun 2021; 12:3328. [PMID: 34099654 PMCID: PMC8184853 DOI: 10.1038/s41467-021-23218-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 03/16/2021] [Indexed: 02/07/2023] Open
Abstract
Innate behaviors consist of a succession of genetically-hardwired motor and physiological subprograms that can be coupled to drastic morphogenetic changes. How these integrative responses are orchestrated is not completely understood. Here, we provide insight into these mechanisms by studying pupariation, a multi-step innate behavior of Drosophila larvae that is critical for survival during metamorphosis. We find that the steroid-hormone ecdysone triggers parallel pupariation neuromotor and morphogenetic subprograms, which include the induction of the relaxin-peptide hormone, Dilp8, in the epidermis. Dilp8 acts on six Lgr3-positive thoracic interneurons to couple both subprograms in time and to instruct neuromotor subprogram switching during behavior. Our work reveals that interorgan feedback gates progression between subunits of an innate behavior and points to an ancestral neuromodulatory function of relaxin signaling.
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Affiliation(s)
- Fabiana Heredia
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Yanel Volonté
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- INIBIBB, Instituto de Investigaciones Bioquímicas de Bahia Blanca, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - Joana Pereirinha
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- Institute of Molecular Biology, Mainz, Germany
| | - Magdalena Fernandez-Acosta
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Andreia P Casimiro
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Cláudia G Belém
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- The Francis Crick Institute, London, UK
| | - Filipe Viegas
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Kohtaro Tanaka
- Instituto Gulbenkian de Ciências, Oeiras, Portugal
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Juliane Menezes
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Maite Arana
- INIBIBB, Instituto de Investigaciones Bioquímicas de Bahia Blanca, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - Gisele A Cardoso
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- Laboratório de Genômica e Evolução de Artrópodes, Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, Brazil
- CBMEG, Universidade Estadual de Campinas, Campinas, Brazil
| | - André Macedo
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Malwina Kotowicz
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- DZNE, Helmholtz Association, Bonn, Germany
| | - Facundo H Prado Spalm
- INIBIBB, Instituto de Investigaciones Bioquímicas de Bahia Blanca, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - Marcos J Dibo
- INIBIBB, Instituto de Investigaciones Bioquímicas de Bahia Blanca, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - Raquel D Monfardini
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- Laboratório de Genômica e Evolução de Artrópodes, Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, Brazil
| | - Tatiana T Torres
- Laboratório de Genômica e Evolução de Artrópodes, Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, Brazil
| | - César S Mendes
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Andres Garelli
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.
- INIBIBB, Instituto de Investigaciones Bioquímicas de Bahia Blanca, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina.
| | - Alisson M Gontijo
- CEDOC, Chronic Diseases Research Center, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Rua do Instituto Bacteriológico 5, 1150-190, Lisbon, Portugal.
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14
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Crespo D, Assis LHC, Zhang YT, Safian D, Furmanek T, Skaftnesmo KO, Norberg B, Ge W, Choi YC, den Broeder MJ, Legler J, Bogerd J, Schulz RW. Insulin-like 3 affects zebrafish spermatogenic cells directly and via Sertoli cells. Commun Biol 2021; 4:204. [PMID: 33589679 PMCID: PMC7884674 DOI: 10.1038/s42003-021-01708-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/13/2021] [Indexed: 01/31/2023] Open
Abstract
Pituitary hormones can use local signaling molecules to regulate target tissue functions. In adult zebrafish testes, follicle-stimulating hormone (Fsh) strongly increases the production of insulin-like 3 (Insl3), a Leydig cell-derived growth factor found in all vertebrates. Little information is available regarding Insl3 function in adult spermatogenesis. The Insl3 receptors Rxfp2a and 2b were expressed by type A spermatogonia and Sertoli and myoid cells, respectively, in zebrafish testis tissue. Loss of insl3 increased germ cell apoptosis in males starting at 9 months of age, but spermatogenesis appeared normal in fully fertile, younger adults. Insl3 changed the expression of 409 testicular genes. Among others, retinoic acid (RA) signaling was up- and peroxisome proliferator-activated receptor gamma (Pparg) signaling was down-regulated. Follow-up studies showed that RA and Pparg signaling mediated Insl3 effects, resulting in the increased production of differentiating spermatogonia. This suggests that Insl3 recruits two locally active nuclear receptor pathways to implement pituitary (Fsh) stimulation of spermatogenesis.
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Affiliation(s)
- Diego Crespo
- grid.5477.10000000120346234Reproductive Biology Group, Division Developmental Biology, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands ,grid.10917.3e0000 0004 0427 3161Present Address: Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Luiz H. C. Assis
- grid.5477.10000000120346234Reproductive Biology Group, Division Developmental Biology, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands
| | - Yu Ting Zhang
- grid.12955.3a0000 0001 2264 7233State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Fujian, PR China ,grid.449133.80000 0004 1764 3555Present Address: Institute of Oceanography, Minjiang University, Fuzhou, PR China
| | - Diego Safian
- grid.5477.10000000120346234Reproductive Biology Group, Division Developmental Biology, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands ,grid.4818.50000 0001 0791 5666Present Address: Experimental Zoology Group and Aquaculture and Fisheries Group, Department of Animal Science, Wageningen University, Wageningen, The Netherlands
| | - Tomasz Furmanek
- grid.10917.3e0000 0004 0427 3161Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Kai Ove Skaftnesmo
- grid.10917.3e0000 0004 0427 3161Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Birgitta Norberg
- grid.10917.3e0000 0004 0427 3161Institute of Marine Research, Austevoll Research Station, Storebø, Norway
| | - Wei Ge
- grid.437123.00000 0004 1794 8068Center of Reproduction, Development and Aging (CRDA), Faculty of Health Sciences, University of Macau, Taipa, Macau China
| | - Yung-Ching Choi
- grid.437123.00000 0004 1794 8068Center of Reproduction, Development and Aging (CRDA), Faculty of Health Sciences, University of Macau, Taipa, Macau China
| | - Marjo J. den Broeder
- grid.5477.10000000120346234Division of Toxicology, Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Juliette Legler
- grid.5477.10000000120346234Division of Toxicology, Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jan Bogerd
- grid.5477.10000000120346234Reproductive Biology Group, Division Developmental Biology, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands
| | - Rüdiger W. Schulz
- grid.5477.10000000120346234Reproductive Biology Group, Division Developmental Biology, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands ,grid.10917.3e0000 0004 0427 3161Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
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Irwin DM. Evolution of the Insulin Gene: Changes in Gene Number, Sequence, and Processing. Front Endocrinol (Lausanne) 2021; 12:649255. [PMID: 33868177 PMCID: PMC8051583 DOI: 10.3389/fendo.2021.649255] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/01/2021] [Indexed: 02/05/2023] Open
Abstract
Insulin has not only made major contributions to the field of clinical medicine but has also played central roles in the advancement of fundamental molecular biology, including evolution. Insulin is essential for the health of vertebrate species, yet its function has been modified in species-specific manners. With the advent of genome sequencing, large numbers of insulin coding sequences have been identified in genomes of diverse vertebrates and have revealed unexpected changes in the numbers of genes within genomes and in their sequence that likely impact biological function. The presence of multiple insulin genes within a genome potentially allows specialization of an insulin gene. Discovery of changes in proteolytic processing suggests that the typical two-chain hormone structure is not necessary for all of inulin's biological activities.
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Affiliation(s)
- David M. Irwin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
- *Correspondence: David M. Irwin,
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16
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DeAdder NP, Gillam HJ, Wilson BC. Relaxin peptides reduce cellular damage in cultured brain slices exposed to transient oxygen–glucose deprivation: an effect mediated by nitric oxide. Facets (Ott) 2021. [DOI: 10.1139/facets-2020-0029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effect of treatment with human relaxins on cell death was studied in oxygen- and glucose-deprived brain slices. In addition, involvement of nitric oxide and the relaxin receptor, RXFP3, was studied. Brain slices ( n = 12–18/group) were cultured under standard conditions for two weeks and then exposed to: ( i) an oxygenated balanced salt solution, ( ii) a deoxygenated, glucose-free balanced salt solution (OGD media), or ( iii) OGD media containing 10−7 mol/L H2 relaxin, 10−7 mol/L H2 relaxin with 50 μmol/L L-NIL, 10−7 mol/L H3 relaxin, or 10−7 mol/L H3 relaxin with 50 μmol/L L-NIL. Cell death was assessed using propidium iodide fluorescence. In a separate experiment, 10−5 mol/L R3 B1-22R (an antagonist of RXFP3) was added to both H2 and H3 relaxin treatments. H2 and H3 relaxin treatment reduced cell damage or death in OGD slices and L-NIL partially attenuated the effect of H3 relaxin. Antagonism of RXFP3 blocked the effect of H3 but not H2 relaxin. These data increase our understanding of the role of relaxin ligands and their receptors in protecting tissues throughout the body from ischemia and reperfusion injury.
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Affiliation(s)
| | - Hannah J. Gillam
- Department of Biology, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Brian C. Wilson
- Department of Biology, Acadia University, Wolfville, NS B4P 2R6, Canada
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17
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Mita M, Matsubara S, Osugi T, Shiraishi A, Wada A, Satake H. A novel G protein-coupled receptor for starfish gonadotropic hormone, relaxin-like gonad-stimulating peptide. PLoS One 2020; 15:e0242877. [PMID: 33226996 PMCID: PMC7682835 DOI: 10.1371/journal.pone.0242877] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/10/2020] [Indexed: 12/12/2022] Open
Abstract
Gonadotropic hormones play important regulatory roles in reproduction. Relaxin-like gonad-stimulating peptide (RGP) is a gonadotropin-like hormone in starfish. However, a receptor for RGP remains to be identified. Here, we describe the identification of an authentic receptor for RGP (RGPR) in the starfish, Patiria pectinifera. A binding assay using radioiodinated P. pectinifera RGP (PpeRGP) revealed that RGPR was expressed in ovarian follicle cells. A RGPR candidate was identified by homology-searching of transcriptome data of P. pectinifera follicle cells. Based on the contig sequences, a putative 947-amino acid PpeRGPR was cloned from follicle cells. Like the vertebrate relaxin family peptide receptors (RXFP 1 and 2), PpeRGPR was a G protein-coupled receptor that harbored a low-density lipoprotein-receptor class A motif and leucine-rich repeat sequences in the extracellular domain of the N-terminal region. Sf9 cells transfected with Gαq16-fused PpeRGPR activated calcium ion mobilization in response to PpeRGP, but not to RGP of another starfish Asterias amurensis, in a dose-dependent fashion. These results confirmed the species-specific reactivity of RGP and the cognate receptor. Thus, the present study provides evidence that PpeRGPR is a specific receptor for PpeRGP. To the best of our knowledge, this is the first report on the identification of a receptor for echinoderm RGP.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, Tokyo, Japan
| | - Shin Matsubara
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Tomohiro Osugi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Akira Shiraishi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Azumi Wada
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
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18
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Li P, Zhao G, Chen F, Ding Y, Wang T, Liu S, Lu W, Xu W, Flores J, Ocak U, Zhang T, Zhang JH, Tang J. Rh-relaxin-2 attenuates degranulation of mast cells by inhibiting NF-κB through PI3K-AKT/TNFAIP3 pathway in an experimental germinal matrix hemorrhage rat model. J Neuroinflammation 2020; 17:250. [PMID: 32859236 PMCID: PMC7455905 DOI: 10.1186/s12974-020-01926-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 08/13/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Mast cells play an important role in early immune reactions in the brain by degranulation and the consequent inflammatory response. Our aim of the study is to investigate the effects of rh-relaxin-2 on mast cells and the underlying mechanisms in a germinal matrix hemorrhage (GMH) rat model. METHODS One hundred seventy-three P7 rat pups were subjected to GMH by an intraparenchymal injection of bacterial collagenase. Clodronate liposome was administered through intracerebroventricular (i.c.v.) injections 24 h prior to GMH to inhibit microglia. Rh-relaxin-2 was administered intraperitoneally at 1 h and 13 h after GMH. Small interfering RNA of RXFP1 and PI3K inhibitor LY294002 were given by i.c.v. injection. Post-GMH evaluation included neurobehavioral function, Western blot analysis, immunofluorescence, Nissl staining, and toluidine blue staining. RESULTS Our results demonstrated that endogenous relaxin-2 was downregulated and that RXFP1 level peaked on the first day after GMH. Administration of rh-relaxin-2 improved neurological functions, attenuated degranulation of mast cells and neuroinflammation, and ameliorated post-hemorrhagic hydrocephalus (PHH) after GMH. These effects were associated with RXFP1 activation, increased expression of PI3K, phosphorylated AKT and TNFAIP3, and decreased levels of phosphorylated NF-κB, tryptase, chymase, IL-6, and TNF-α. However, knockdown of RXFP1 and PI3K inhibition abolished the protective effects of rh-relaxin-2. CONCLUSIONS Our findings showed that rh-relaxin-2 attenuated degranulation of mast cells and neuroinflammation, improved neurological outcomes, and ameliorated hydrocephalus after GMH through RXFP1/PI3K-AKT/TNFAIP3/NF-κB signaling pathway.
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Affiliation(s)
- Peng Li
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Gang Zhao
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
- Department of Emergency Surgery, The Second Affiliated Hospital of Kunming Medical University, Kunming, 650101, China
- Traumatic Research Center of Yunnan Province, Kunming, 650101, China
| | - Fanfan Chen
- Department of Neurosurgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, 518000, China
| | - Yan Ding
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Tianyi Wang
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Shengpeng Liu
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Weitian Lu
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Weilin Xu
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Jerry Flores
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Umut Ocak
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Tongyu Zhang
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - John H Zhang
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA
- Departments of Anesthesiology, Neurosurgery and Neurology, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, Basic Science, School of Medicine, Loma Linda University, Risley Hall, 11041 Campus St, Loma Linda, CA, 92354, USA.
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Recombinant human H2 relaxin (serelaxin) as a cardiovascular drug: aiming at the right target. Drug Discov Today 2020; 25:1239-1244. [PMID: 32360533 DOI: 10.1016/j.drudis.2020.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/08/2020] [Accepted: 04/19/2020] [Indexed: 01/25/2023]
Abstract
Serelaxin (recombinant human relaxin-2 hormone; RLX-2) had raised expectations as a new medication for cardiovascular diseases. Evidence from preclinical studies indicated that serelaxin has chronotropic, inotropic, and anti-arrhythmic actions on the myocardium and cardioprotective effects mediated by vasodilation, angiogenesis, and inhibition of inflammation and fibrosis. However, clinical trials with serelaxin in patients with acute heart failure (AHF) gave inconclusive results. A critical reappraisal of the comprehensive cardiovascular actions of serelaxin clearly delineates acute myocardial infarction (AMI) as a feasible therapeutic target. Serelaxin acts at multiple levels on the pathogenic mechanisms of AMI and previous in vivo studies suggest that its administration at reperfusion affords myocardial salvage. Thus, serelaxin could be an effective adjunctive medical therapy to coronary angioplasty.
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20
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Chen TY, Li X, Hung CH, Bahudhanapati H, Tan J, Kass DJ, Zhang Y. The relaxin family peptide receptor 1 (RXFP1): An emerging player in human health and disease. Mol Genet Genomic Med 2020; 8:e1194. [PMID: 32100955 PMCID: PMC7196478 DOI: 10.1002/mgg3.1194] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/11/2020] [Indexed: 12/14/2022] Open
Abstract
Background Relaxin/relaxin family peptide receptor 1 (RXFP1) signaling is important for both normal physiology and disease. Strong preclinical evidence supports relaxin as a potent antifibrotic molecule. However, relaxin‐based therapy failed in clinical trial in patients with systemic sclerosis. We and others have discovered that aberrant expression of RXFP1 may contribute to the abnormal relaxin/RXFP1 signaling in different diseases. Reduced RXFP1 expression and alternative splicing transcripts with potential functional consequences have been observed in fibrotic tissues. A relative decrease in RXFP1 expression in fibrotic tissues—specifically lung and skin—may explain a potential insensitivity to relaxin. In addition, receptor dimerization also plays important roles in relaxin/RXFP1 signaling. Methods This review describes the tissue specific expression, characteristics of the splicing variants, and homo/heterodimerization of RXFP1 in both normal physiological function and human diseases. We discuss the potential implications of these molecular features for developing therapeutics to restore relaxin/RXFP1 signaling and to harness relaxin's potential antifibrotic effects. Results Relaxin/RXFP1 signaling is important in both normal physiology and in human diseases. Reduced expression of RXFP1 in fibrotic lung and skin tissues surrenders both relaxin/RXFP1 signaling and their responsiveness to exogenous relaxin treatments. Alternative splicing and receptor dimerization are also important in regulating relaxin/RXFP1 signaling. Conclusions Understanding the molecular mechanisms that drive aberrant expression of RXFP1 in disease and the functional roles of alternative splicing and receptor dimerization will provide insight into therapeutic targets that may restore the relaxin responsiveness of fibrotic tissues.
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Affiliation(s)
- Ting-Yun Chen
- Division of Pulmonary, Allergy and Critical Care Medicine and the Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, USA.,Institute of Allied Health Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Xiaoyun Li
- Division of Pulmonary, Allergy and Critical Care Medicine and the Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ching-Hsia Hung
- Institute of Allied Health Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Harinath Bahudhanapati
- Division of Pulmonary, Allergy and Critical Care Medicine and the Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jiangning Tan
- Division of Pulmonary, Allergy and Critical Care Medicine and the Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, USA
| | - Daniel J Kass
- Division of Pulmonary, Allergy and Critical Care Medicine and the Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yingze Zhang
- Division of Pulmonary, Allergy and Critical Care Medicine and the Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA, USA
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Welch NG, Mukherjee S, Hossain MA, Praveen P, Werkmeister JA, Wade JD, Bathgate RAD, Winkler DA, Thissen H. Coatings Releasing the Relaxin Peptide Analogue B7-33 Reduce Fibrotic Encapsulation. ACS APPLIED MATERIALS & INTERFACES 2019; 11:45511-45519. [PMID: 31713411 DOI: 10.1021/acsami.9b17859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The development of antifibrotic materials and coatings that can resist the foreign body response (FBR) continues to present a major hurdle in the advancement of current and next-generation implantable medical devices, biosensors, and cell therapies. From an implant perspective, the most important issue associated with the FBR is the prolonged inflammatory response leading to a collagenous capsule that ultimately blocks mass transport and communication between the implant and the surrounding tissue. Up to now, most attempts to reduce the capsule thickness have focused on providing surface coatings that reduce protein fouling and cell attachment. Here, we present an approach that is based on the sustained release of a peptide drug interfering with the FBR. In this study, the biodegradable polymer poly(lactic-co-glycolic) acid (PLGA) was used as a coating releasing the relaxin peptide analogue B7-33, which has been demonstrated to reduce organ fibrosis in animal models. While in vitro protein quantification was used to demonstrate controlled release of the antifibrotic peptide B7-33 from PLGA coatings, an in vitro reporter cell assay was used to demonstrate that B7-33 retains activity against the relaxin family peptide receptor 1 (RXFP1). Subcutaneous implantation of PLGA-coated polypropylene samples in mice with and without the peptide demonstrated a marked reduction in capsule thickness (49.2%) over a 6 week period. It is expected that this novel approach will open the door to a range of new and improved implantable medical devices.
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Affiliation(s)
- Nicholas G Welch
- CSIRO Manufacturing , Research Way , Clayton , VIC 3168 , Australia
| | - Shayanti Mukherjee
- The Ritchie Centre , Hudson Institute of Medical Research , Clayton , VIC 3168 , Australia
| | - Mohammed A Hossain
- The Florey Institute of Neuroscience and Mental Health , Parkville , VIC 3052 , Australia
| | - Praveen Praveen
- The Florey Institute of Neuroscience and Mental Health , Parkville , VIC 3052 , Australia
| | - Jerome A Werkmeister
- The Ritchie Centre , Hudson Institute of Medical Research , Clayton , VIC 3168 , Australia
| | - John D Wade
- The Florey Institute of Neuroscience and Mental Health , Parkville , VIC 3052 , Australia
| | - Ross A D Bathgate
- The Florey Institute of Neuroscience and Mental Health , Parkville , VIC 3052 , Australia
| | - David A Winkler
- CSIRO Manufacturing , Research Way , Clayton , VIC 3168 , Australia
- La Trobe Institute for Molecular Science , La Trobe University , Kingsbury Drive , Bundoora , VIC 3083 , Australia
- Monash Institute of Pharmaceutical Sciences , Royal Parade , Parkville , VIC 3052 , Australia
- School of Pharmacy , The University of Nottingham , Nottingham NG7 2RD , U.K
| | - Helmut Thissen
- CSIRO Manufacturing , Research Way , Clayton , VIC 3168 , Australia
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22
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Sun J, Hao W, Fillmore N, Ma H, Springer D, Yu ZX, Sadowska A, Garcia A, Chen R, Muniz-Medina V, Rosenthal K, Lin J, Kuruvilla D, Osbourn J, Karathanasis SK, Walker J, Murphy E. Human Relaxin-2 Fusion Protein Treatment Prevents and Reverses Isoproterenol-Induced Hypertrophy and Fibrosis in Mouse Heart. J Am Heart Assoc 2019; 8:e013465. [PMID: 31818212 PMCID: PMC6951077 DOI: 10.1161/jaha.119.013465] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background Heart failure is one of the leading causes of death in Western countries, and there is a need for new therapeutic approaches. Relaxin‐2 is a peptide hormone that mediates pleiotropic cardiovascular effects, including antifibrotic, angiogenic, vasodilatory, antiapoptotic, and anti‐inflammatory effects in vitro and in vivo. Methods and Results We developed RELAX10, a fusion protein composed of human relaxin‐2 hormone and the Fc of a human antibody, to test the hypothesis that extended exposure of the relaxin‐2 peptide could reduce cardiac hypertrophy and fibrosis. RELAX10 demonstrated the same specificity and similar in vitro activity as the relaxin‐2 peptide. The terminal half‐life of RELAX10 was 7 days in mouse and 3.75 days in rat after subcutaneous administration. We evaluated whether treatment with RELAX10 could prevent and reverse isoproterenol‐induced cardiac hypertrophy and fibrosis in mice. Isoproterenol administration in mice resulted in increased cardiac hypertrophy and fibrosis compared with vehicle. Coadministration with RELAX10 significantly attenuated the cardiac hypertrophy and fibrosis compared with untreated animals. Isoproterenol administration significantly increased transforming growth factor β1 (TGF‐β1)–induced fibrotic signaling, which was attenuated by RELAX10. We found that RELAX10 also significantly increased protein kinase B/endothelial NO synthase signaling and protein S‐nitrosylation. In the reversal study, RELAX10‐treated animals showed significantly reduced cardiac hypertrophy and collagen levels. Conclusions These findings support a potential role for RELAX10 in the treatment of heart failure.
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Affiliation(s)
- Junhui Sun
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | | | - Natasha Fillmore
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | - Hanley Ma
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | - Danielle Springer
- Murine Phenotyping Core National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | - Zu-Xi Yu
- Pathology Core National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | | | | | | | | | | | | | | | | | | | | | - Elizabeth Murphy
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
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23
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Mita M, Nakamura K, Tsutsui K, Katayama H. Interaction of starfish gonadotropin with its receptor: Effect of chimeric relaxin-like gonad-stimulating peptides. Gen Comp Endocrinol 2019; 276:30-36. [PMID: 30796897 DOI: 10.1016/j.ygcen.2019.02.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/15/2019] [Accepted: 02/19/2019] [Indexed: 10/27/2022]
Abstract
A relaxin-like gonad-stimulating peptide (RGP) of starfish Patiria (Asterina) pectinifera is the first identified invertebrate gonadotropin for final gamete maturation. Recently, we found three orthologs of RGP in the class Asteroida; PpeRGP in P. pectinifera, AamRGP in Asterias amurensis, and AjaRGP in Aphelasterias japonica. In this study, nine kinds of RGP derivatives with exchanged each A- and B-chain were synthesized chemically to analyze the interaction of RGP with its receptor. Among these RGP derivatives, PpeRGP and its chimeric RGPs with B-chains from AamRGP or AjaRGP could induce oocyte maturation and ovulation in P. pectinifera ovaries. In contrast, other RGP derivatives were failed to induce spawning in P. pectinifera ovaries. Circular dichroism spectra of PpeRGP were similar to those of chimeric RGPs with the B-chains from AamRGP or AjaRGP. Furthermore, the predicted three-dimensional structure models of the B-chains from RGP derivatives have almost the same conformation. These findings suggest that the B-chain of PpeRGP is involved in binding to its receptor. Thus, it is likely that the A-chain of AamRGP or AjaRGP disturbs the binding of the PpeRGP B-chain to its receptor.
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Affiliation(s)
- Masatoshi Mita
- Center for Advanced Biomedical Sciences, Research Institute for Science and Engineering, Waseda University, 2-2, Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
| | - Keitaro Nakamura
- Department of Applied Biochemistry, School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
| | - Kazuyoshi Tsutsui
- Center for Advanced Biomedical Sciences, Research Institute for Science and Engineering, Waseda University, 2-2, Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan; Laboratory of Integrative Brain Sciences, Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, Wakamatsucho 2-2, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Hidekazu Katayama
- Department of Applied Biochemistry, School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
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24
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Thanasupawat T, Glogowska A, Nivedita-Krishnan S, Wilson B, Klonisch T, Hombach-Klonisch S. Emerging roles for the relaxin/RXFP1 system in cancer therapy. Mol Cell Endocrinol 2019; 487:85-93. [PMID: 30763603 DOI: 10.1016/j.mce.2019.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 02/06/2023]
Abstract
A role for the hormone relaxin in cancer was described well before the receptor was identified. Relaxin predominantly increases the growth and invasive potential in cancers of different origins. However, relaxin was also shown to promote cell differentiation and to act in a dose-and time-dependent manner in different cancer cell models used. Following the discovery of the relaxin like family peptide receptor 1 (RXFP1) as the cellular receptor for RLN1 and RLN2, research has focussed on the ligand interaction with the large extracellular domain of RXFP1 and resulting molecular signaling mechanisms. RXFP1 activation mediates anti-apoptotic functions, angiogenesis and chemoresistance in cancer cells. This minireview summarizes the known biological functions of RXFP1 activation in different cancer entities in-vitro and in-vivo and outlines possible mechanisms to therapeutically address the relaxin-RXFP1 system in cancer cells.
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Affiliation(s)
- Thatchawan Thanasupawat
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Aleksandra Glogowska
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Sai Nivedita-Krishnan
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Brian Wilson
- Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada
| | - Thomas Klonisch
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Sabine Hombach-Klonisch
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, Canada.
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25
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Valkovic AL, Bathgate RA, Samuel CS, Kocan M. Understanding relaxin signalling at the cellular level. Mol Cell Endocrinol 2019; 487:24-33. [PMID: 30592984 DOI: 10.1016/j.mce.2018.12.017] [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: 11/12/2018] [Revised: 12/19/2018] [Accepted: 12/22/2018] [Indexed: 02/07/2023]
Abstract
The peptide hormone relaxin mediates many biological actions including anti-fibrotic, vasodilatory, angiogenic, anti-inflammatory, anti-apoptotic, and organ protective effects across a range of tissues. At the cellular level, relaxin binds to the G protein-coupled receptor relaxin family peptide receptor 1 (RXFP1) to activate a variety of downstream signal transduction pathways. This signalling cascade is complex and also varies in diverse cellular backgrounds. Moreover, RXFP1 signalling shows crosstalk with other receptors to mediate some of its physiological functions. This review summarises known signalling pathways induced by acute versus chronic treatment with relaxin across a range of cell types, it describes RXFP1 crosstalk with other receptors, signalling pathways activated by other ligands targeting RXFP1, and it also outlines physiological relevance of RXFP1 signalling outputs. Comprehensive understanding of the mechanism of relaxin actions in fibrosis, vasodilation, as well as organ protection, will further support relaxin's clinical potential.
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Affiliation(s)
- Adam L Valkovic
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Ross Ad Bathgate
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, 3010, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, 3052, Australia.
| | - Chrishan S Samuel
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
| | - Martina Kocan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, 3010, Australia.
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26
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Alnafea H, Vahkal B, Zelmer CK, Yegorov S, Bogerd J, Good SV. Japanese medaka as a model for studying the relaxin family genes involved in neuroendocrine regulation: Insights from the expression of fish-specific rln3 and insl5 and rxfp3/4-type receptor paralogues. Mol Cell Endocrinol 2019; 487:2-11. [PMID: 30703485 DOI: 10.1016/j.mce.2019.01.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/17/2019] [Accepted: 01/19/2019] [Indexed: 12/14/2022]
Abstract
The goal of this paper is to establish Japanese medaka (Oryzias latipes) as a model for relaxin family peptide research, particularly for studying the functions of RLN3 and INSL5, hormones playing roles in neuroendocrine regulation. Medaka, like other teleosts, retained duplicate copies of rln3, insl5 and their rxfp3/4-type receptors following fish-specific whole genome duplication (WGD) and paralogous copies of these genes may have sub-functionalised providing an intuitive model for teasing apart the pleiotropic roles of the corresponding genes in mammals. To this end, we provide experimental evidence for the expression of the relaxin family genes in medaka that had previously only been identified in-silico, confirm the gene structure of five of the ligand genes, characterise gene expression across multiple tissues and during embryonic development, perform in situ hybridization with anti-sense insl5a on embryos and in adult brain and intestinal samples, and compare these results to the data available in zebrafish. We find broad similarities but also some differences in the expression of relaxin family genes in zebrafish versus medaka, and find support for the hypothesis that the rln3a/rln3b and insl5a/insl5b paralogues have been subfunctionalized. Given that medaka has a suite of relaxin family genes more similar to other teleosts, and has retained the gene for rxfp4 (which is lost in zebrafish), our results suggest that O. latipes may be a good model for delineating the ancestral function of the relaxin family genes involved in neuroendocrine regulation.
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Affiliation(s)
- Hend Alnafea
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada
| | - Brett Vahkal
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada
| | - C Kellie Zelmer
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada
| | - Sergey Yegorov
- Department of Immunology, The University of Toronto, Toronto, ON, Canada
| | - Jan Bogerd
- Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Sara V Good
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada; Department of Biology, The University of Manitoba, Winnipeg, MB, Canada.
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27
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Recent developments in relaxin mimetics as therapeutics for cardiovascular diseases. Curr Opin Pharmacol 2019; 45:42-48. [PMID: 31048209 DOI: 10.1016/j.coph.2019.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 02/23/2019] [Accepted: 04/01/2019] [Indexed: 01/02/2023]
Abstract
Cardiovascular disease is the most common cause of mortality worldwide, accounting for almost 50% of all deaths globally. Vascular endothelial dysfunction and fibrosis are critical in the pathophysiology of cardiovascular disease. Relaxin, an insulin-like peptide, is known to have beneficial actions in the cardiovascular system through its vasoprotective and anti-fibrotic effects. However, relaxin has several limitations of peptide-based drugs such as poor oral bioavailability, laborious, and expensive to synthesize. This review will focus on recent developments in relaxin mimetics, their pharmacology, associated signalling mechanisms, and their therapeutic potential for the management and treatment of cardiovascular disease.
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28
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Mita M. Starfish Gonadotropic Hormone: From Gamete-Shedding Substance to Relaxin-Like Gonad-Stimulating Peptide. Front Endocrinol (Lausanne) 2019; 10:182. [PMID: 30967842 PMCID: PMC6442644 DOI: 10.3389/fendo.2019.00182] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/04/2019] [Indexed: 12/02/2022] Open
Abstract
The first report of a gonadotropic substance in an invertebrate hot-water extract of radial nerve cords from starfish Asterias forbesi that induced the shedding of gametes when injected into the coelomic cavity in a ripe individual occurred in 1959. The active substance was named gamete-shedding substance (GSS) or radial nerve factor. GSS is the primary mediator of oocyte maturation and ovulation in starfish. However, the effect of GSS is indirect. Resumption of meiosis in immature oocytes and release from the ovary are induced by a second mediator, maturation-inducing hormone, identified as 1-methyladenine (1-MeAde) in starfish. The role of GSS is to induce 1-MeAde production by ovarian follicle cells. Thus, GSS was redesignated as gonad-stimulating substance (also GSS). Although GSS has been characterized biochemically as a peptide hormone, identification of the chemical structure had to wait until 2009. Fifty years after the initial finding, GSS was purified from the radial nerve cords of starfish Patiria pectinifera (P. pectinifera). The purified hormone was a heterodimer composed of A- and B-chains, with disulfide cross-linkages. Based on its cysteine motif, GSS is classified as a member of the insulin/insulin-like growth factor (IGF)/relaxin superfamily. More specifically, phylogenetic sequence analysis revealed that P. pectinifera GSS is a member of the relaxin-type peptide family. Therefore, GSS in starfish has been redesignated as relaxin-like gonad-stimulating peptide (RGP). Subsequently, orthologs of P. pectinifera RGP have been identified in other starfish species, including Asterias amurensis (A. amurensis), and Aphelasterias japonica (A. japonica).
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Affiliation(s)
- Masatoshi Mita
- Center for Advanced Biomedical Sciences, Research Institute for Science and Engineering, Waseda University, Tokyo, Japan
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29
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Transforming growth factor β (TGFβ) and related molecules in chronic kidney disease (CKD). Clin Sci (Lond) 2019; 133:287-313. [DOI: 10.1042/cs20180438] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/04/2018] [Accepted: 01/07/2019] [Indexed: 02/07/2023]
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30
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Valkovic AL, Leckey MB, Whitehead AR, Hossain MA, Inoue A, Kocan M, Bathgate RAD. Real-time examination of cAMP activity at relaxin family peptide receptors using a BRET-based biosensor. Pharmacol Res Perspect 2018; 6:e00432. [PMID: 30263124 PMCID: PMC6153321 DOI: 10.1002/prp2.432] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 08/29/2018] [Indexed: 12/11/2022] Open
Abstract
Relaxin family peptide (RXFPs) 1-4 receptors modulate the activity of cyclic adenosine monophosphate (cAMP) to produce a range of physiological functions. RXFP1 and RXFP2 increase cAMP via Gαs, whereas RXFP3 and RXFP4 inhibit cAMP via Gαi/o. RXFP1 also shows a delayed increase in cAMP downstream of Gαi3. In this study we have assessed whether the bioluminescence resonance energy transfer (BRET)-based biosensor CAMYEL (cAMP sensor using YFP-Epac-Rluc), which allows real-time measurement of cAMP activity in live cells, will aid in understanding ligand- and cell-specific RXFP signaling. CAMYEL detected concentration-dependent changes in cAMP activity at RXFP1-4 in recombinant cell lines, using a variety of ligands with potencies comparable to those seen in conventional cAMP assays. We used RXFP2 and RXFP3 antagonists to demonstrate that CAMYEL detects dynamic changes in cAMP by reversing cAMP activation or inhibition respectively, with real-time addition of antagonist after agonist stimulation. To demonstrate the utility of CAMYEL to detect cAMP activation in native cells expressing low levels of RXFP receptor, we cloned CAMYEL into a lentiviral vector and transduced THP-1 cells, which express low levels of RXFP1. THP-1 CAMYEL cells demonstrated robust cAMP activation in response to relaxin. However, the CAMYEL assay was unable to detect the Gαi3-mediated phase of RXFP1 cAMP activation in PTX-treated THP-1 cells or HEK293A cells with knockout of Gαs. Our data demonstrate that cytoplasmically-expressed CAMYEL efficiently detects real-time cAMP activation by Gαs or inhibition by Gαi/o but may not detect cAMP generated in specific intracellular compartments such as that generated by Gαi3 upon RXFP1 activation.
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Affiliation(s)
- Adam L. Valkovic
- Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
| | - Miranda B. Leckey
- Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
| | - Alice R. Whitehead
- Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
| | - Mohammed A. Hossain
- Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
| | - Asuka Inoue
- Graduate School of Pharmaceutical SciencesTohoku UniversityAobaMiyagiJapan
| | - Martina Kocan
- Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
| | - Ross A. D. Bathgate
- Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
- Department of Biochemistry and Molecular BiologyThe University of MelbourneParkvilleVictoriaAustralia
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31
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Ivell R, Anand-Ivell R. Insulin-like peptide 3 (INSL3) is a major regulator of female reproductive physiology. Hum Reprod Update 2018; 24:639-651. [DOI: 10.1093/humupd/dmy029] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/31/2018] [Indexed: 12/16/2022] Open
Affiliation(s)
- Richard Ivell
- School of Biosciences, University of Nottingham, Sutton Bonington, UK
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK
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