1
|
Romero G, Martin B, Gabris B, Salama G. Relaxin suppresses atrial fibrillation, reverses fibrosis and reduces inflammation in aged hearts. Biochem Pharmacol 2024; 227:116407. [PMID: 38969298 DOI: 10.1016/j.bcp.2024.116407] [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: 03/19/2024] [Revised: 06/18/2024] [Accepted: 07/02/2024] [Indexed: 07/07/2024]
Abstract
Healthy aging results in cardiac structural and electrical remodeling that increase susceptibility to cardiovascular diseases. Relaxin has shown broad cardioprotective effects including anti-fibrotic, anti-arrhythmic and anti-inflammatory outcomes in multiple models. This paper focuses on the cardioprotective effects of Relaxin in a rat model of aging. Sustained atrial or ventricular fibrillation are readily induced in the hearts of aged but not young control animals. Treatment with Relaxin suppressed this arrhythmogenic response by increasing conduction velocity, decreasing fibrosis and promoting substantial cardiac remodeling. Relaxin treatment resulted in a significant increase in the levels of: Nav1.5, Cx43, βcatenin and Wnt1 in rat hearts. In isolated cardiomyocytes, Relaxin increased Nav1.5 expression. These effects were mimicked by CHIR 99021, a pharmacological activator of canonical Wnt signaling, but blocked by the canonical Wnt inhibitor Dickkopf1. Relaxin prevented TGF-β-dependent differentiation of cardiac fibroblasts into myofibroblasts while increasing the expression of Wnt1; the effects of Relaxin on cardiac fibroblast differentiation were blocked by Dickkopf1. RNASeq studies demonstrated reduced expression of pro-inflammatory cytokines and an increase in the expression of α- and β-globin in Relaxin-treated aged males. Relaxin reduces arrhythmogenicity in the hearts of aged rats by reduction of fibrosis and increased conduction velocity. These changes are accompanied by substantial remodeling of the cardiac tissue and appear to be mediated by increased canonical Wnt signaling. Relaxin also exerts significant anti-inflammatory and anti-oxidant effects in the hearts of aged rodents. The mechanisms by which Relaxin increases the expression of Wnt ligands, promotes Wnt signaling and reprograms gene expression remain to be determined.
Collapse
Affiliation(s)
- Guillermo Romero
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Brian Martin
- Departments of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Beth Gabris
- Departments of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Guy Salama
- Departments of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|
2
|
Samuel CS, Li Y, Wang Y, Widdop RE. Functional crosstalk between angiotensin receptors (types 1 and 2) and relaxin family peptide receptor 1 (RXFP1): Implications for the therapeutic targeting of fibrosis. Br J Pharmacol 2024; 181:2302-2318. [PMID: 36560925 DOI: 10.1111/bph.16019] [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: 08/29/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Class A, rhodopsin-like, G-protein-coupled receptors (GPCRs) are by far the largest class of GPCRs and are integral membrane proteins used by various cells to convert extracellular signals into intracellular responses. Initially, class A GPCRs were believed to function as monomers, but a growing body of evidence has emerged to suggest that these receptors can function as homodimers and heterodimers and can undergo functional crosstalk to influence the actions of agonists or antagonists acting at each receptor. This review will focus on the angiotensin type 1 (AT1) and type 2 (AT2) receptors, as well as the relaxin family peptide receptor 1 (RXFP1), each of which have their unique characteristics but have been demonstrated to undergo some level of interaction when appropriately co-expressed, which influences the function of each receptor. In particular, this receptor functional crosstalk will be discussed in the context of fibrosis, the tissue scarring that results from a failed wound-healing response to injury, and which is a hallmark of chronic disease and related organ dysfunction. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
Collapse
Affiliation(s)
- Chrishan S Samuel
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Yifang Li
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Yan Wang
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Robert E Widdop
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
3
|
Ding C, Wang B, Lai XF, Guo Y, Tesch G, Ding X, Zheng J, Tian P, Ricardo S, Shen HH, Xue W. Cellular delivery of relaxin-2 mRNA as a potential treatment for kidney fibrosis. Mater Today Bio 2023; 21:100716. [PMID: 37545557 PMCID: PMC10401360 DOI: 10.1016/j.mtbio.2023.100716] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/18/2023] [Accepted: 06/23/2023] [Indexed: 08/08/2023] Open
Abstract
Renal fibrosis is a pathological feature of chronic kidney disease and its progression correlates with kidney function impairment. Since there are currently no specific therapies for renal fibrosis, we explored whether inducing local production of the anti-fibrotic molecule relaxin-2 in kidney cells has potential as a strategy for suppressing the development of renal fibrosis. Our study examined whether delivery of relaxin-2 mRNA to kidney cells in vitro and in vivo could inhibit mechanisms leading to renal fibrosis. Transfecting relaxin-2 mRNA into cultured kidney cells inhibited fibrotic responses to TGF-β1 in an autocrine or paracrine manner by reducing fibrotic gene expression in kidney tubules, and reducing proliferation in kidney fibroblasts and mesangial cells. Similarly, cubosomes assisted delivery of relaxin-2 mRNA to mouse kidneys alleviated the fibrosis and inflammation associated with renal injury following unilateral ureter obstruction (UUO). Therefore, relaxin-2 mRNA exhibits potential as a novel therapy for inhibiting fibrosis and inflammation in chronic kidney disease.
Collapse
Affiliation(s)
- Chenguang Ding
- Department of Kidney Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China
- Institute of Organ Transplantation, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Bo Wang
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
| | - Xiang Feng Lai
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
| | - Yingcong Guo
- Department of Kidney Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China
- Institute of Organ Transplantation, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Greg Tesch
- Department of Nephrology and Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria, Australia
| | - Xiaoming Ding
- Department of Kidney Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China
- Institute of Organ Transplantation, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Jin Zheng
- Department of Kidney Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China
| | - PuXun Tian
- Department of Kidney Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China
| | - Sharon Ricardo
- Monash Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Hsin-Hui Shen
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
| | - Wujun Xue
- Department of Kidney Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Relaxin contributes to the elevation of monocytic myeloid-derived suppressor cells in peripheral blood of pregnant canines. J Reprod Immunol 2023; 155:103778. [PMID: 36455400 DOI: 10.1016/j.jri.2022.103778] [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: 07/29/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
Tolerance towards fetal alloantigens in the maternal immune system is essential for maintaining pregnancy. Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells characterized by their ability to suppress immune activity and maintain maternal-fetal immune tolerance. However, the mechanisms underlying MDSC induction have not been elucidated. Herein, we investigated the myeloid-derived suppressor cells (MDSCs) in the peripheral blood of pregnant canines and its induction mechanism. By analyzing the concentration of MDSCs in the peripheral blood of pregnant canines, elevation of MDSCs has been observed during pregnancy. In addition, MDSCs from pregnant canines inhibit T cell activation. These results suggest that the elevated MDSCs in canine pregnancy may contribute to reduces maternal immune activity. To clarify the cause of MDSCs elevation in canine pregnancy, we analyzed the relationship between pregnancy-related hormones (estradiol, progesterone, and relaxin) and MDSCs. Serum relaxin levels, but not estradiol and progesterone, were correlated with the ratio of monocyte MDSCs. Additionally, relaxin induced monocytic MDSCs as well as inhibited T cell activation in vitro. Therefore, relaxin contributes to the elevation of monocytic MDSCs in the peripheral blood of pregnant canines. Our findings highlight the novel role of relaxin in pregnancy and contribute to a better understanding of maternal-fetal immune tolerance.
Collapse
|
6
|
Tapia Cáceres F, Gaspari TA, Hossain MA, Samuel CS. Relaxin Inhibits the Cardiac Myofibroblast NLRP3 Inflammasome as Part of Its Anti-Fibrotic Actions via the Angiotensin Type 2 and ATP (P2X7) Receptors. Int J Mol Sci 2022; 23:ijms23137074. [PMID: 35806076 PMCID: PMC9266307 DOI: 10.3390/ijms23137074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 12/18/2022] Open
Abstract
Chronic NLRP3 inflammasome activation can promote fibrosis through its production of interleukin (IL)-1β and IL-18. Conversely, recombinant human relaxin (RLX) can inhibit the pro-fibrotic interactions between IL-1β, IL-18 and transforming growth factor (TGF)-β1. Here, the broader extent by which RLX targeted the myofibroblast NLRP3 inflammasome to mediate its anti-fibrotic effects was elucidated. Primary human cardiac fibroblasts (HCFs), stimulated with TGF-β1 (to promote myofibroblast (HCMF) differentiation), LPS (to prime the NLRP3 inflammasome) and ATP (to activate the NLRP3 inflammasome) (T+L+A) or benzoylbenzoyl-ATP (to activate the ATP receptor; P2X7R) (T+L+Bz), co-expressed relaxin family peptide receptor-1 (RXFP1), the angiotensin II type 2 receptor (AT2R) and P2X7R, and underwent increased protein expression of toll-like receptor (TLR)-4, NLRP3, caspase-1, IL-1β and IL-18. Whilst RLX co-administration to HCMFs significantly prevented the T+L+A- or T+L+Bz-stimulated increase in these end points, the inhibitory effects of RLX were annulled by the pharmacological antagonism of either RXFP1, AT2R, P2X7R, TLR-4, reactive oxygen species (ROS) or caspase-1. The RLX-induced amelioration of left ventricular inflammation, cardiomyocyte hypertrophy and fibrosis in isoproterenol (ISO)-injured mice, was also attenuated by P2X7R antagonism. Thus, the ability of RLX to ameliorate the myofibroblast NLRP3 inflammasome as part of its anti-fibrotic effects, appeared to involve RXFP1, AT2R, P2X7R and the inhibition of TLR-4, ROS and caspase-1.
Collapse
Affiliation(s)
- Felipe Tapia Cáceres
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Melbourne, VIC 3800, Australia; (F.T.C.); (T.A.G.)
| | - Tracey A. Gaspari
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Melbourne, VIC 3800, Australia; (F.T.C.); (T.A.G.)
| | - Mohammed Akhter Hossain
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC 3010, Australia;
| | - Chrishan S. Samuel
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Melbourne, VIC 3800, Australia; (F.T.C.); (T.A.G.)
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, VIC 3010, Australia
- Correspondence:
| |
Collapse
|
7
|
Samuel CS, Bennett RG. Relaxin as an anti-fibrotic treatment: Perspectives, challenges and future directions. Biochem Pharmacol 2021; 197:114884. [PMID: 34968489 DOI: 10.1016/j.bcp.2021.114884] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 02/07/2023]
Abstract
Fibrosis refers to the scarring and hardening of tissues, which results from a failed immune system-coordinated wound healing response to chronic organ injury and which manifests from the aberrant accumulation of various extracellular matrix components (ECM), primarily collagen. Despite being a hallmark of prolonged tissue damage and related dysfunction, and commonly associated with high morbidity and mortality, there are currently no effective cures for its regression. An emerging therapy that meets several criteria of an effective anti-fibrotic treatment, is the recombinant drug-based form of the human hormone, relaxin (also referred to as serelaxin, which is bioactive in several other species). This review outlines the broad anti-fibrotic and related organ-protective roles of relaxin, mainly from studies conducted in preclinical models of ageing and fibrotic disease, including its ability to ameliorate several aspects of fibrosis progression and maturation, from immune cell infiltration, pro-inflammatory and pro-fibrotic cytokine secretion, oxidative stress, organ hypertrophy, cell apoptosis, myofibroblast differentiation and ECM production, to its ability to facilitate established ECM degradation. Studies that have compared and/or combined these therapeutic effects of relaxin with current standard of care medication have also been discussed, along with the main challenges that have hindered the translation of the anti-fibrotic efficacy of relaxin to the clinic. The review then outlines the future directions as to where scientists and several pharmaceutical companies that have recognized the therapeutic potential of relaxin are working towards, to progress its development as a treatment for human patients suffering from various fibrotic diseases.
Collapse
Affiliation(s)
- Chrishan S Samuel
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3052, Australia.
| | - Robert G Bennett
- Research Service, Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; Department of Internal Medicine, Division of Diabetes, Endocrinology & Metabolism, University of Nebraska Medical Center, Omaha, NE 68198-4130, USA.
| |
Collapse
|
8
|
Martins RC, Pintalhão M, Leite-Moreira A, Castro-Chaves P. Relaxin and the Cardiovascular System: from Basic Science to Clinical Practice. Curr Mol Med 2021; 20:167-184. [PMID: 31642776 DOI: 10.2174/1566524019666191023121607] [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: 02/08/2018] [Revised: 08/07/2019] [Accepted: 10/07/2019] [Indexed: 12/16/2022]
Abstract
The peptide hormone relaxin was originally linked to reproductive physiology, where it is believed to mediate systemic and renal hemodynamic adjustments to pregnancy. Recently, its broad range of effects in the cardiovascular system has been the focus of intensive research regarding its implications under pathological conditions and potential therapeutic potential. An understanding of the multitude of cardioprotective actions prompted the study of serelaxin, recombinant human relaxin-2, for the treatment of acute heart failure. Despite early promising results from phase II studies, recently revealed RELAX-AHF-2 outcomes were rather disappointing and the treatment for acute heart failure remains an unmet medical need. This article reviews the physiologic actions of relaxin on the cardiovascular system and its relevance in the pathophysiology of cardiovascular disease. We summarize the most updated clinical data and discuss future directions of serelaxin for the treatment of acute heart failure. This should encourage additional work to determine how can relaxin's beneficial effects be exploited for the treatment of cardiovascular disease.
Collapse
Affiliation(s)
- Rafael Clara Martins
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal.,Cardiovascular Research Centre, Porto, Portugal.,Internal Medicine Department, São João Hospital Centre, Porto, Portugal
| | - Mariana Pintalhão
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal.,Cardiovascular Research Centre, Porto, Portugal.,Internal Medicine Department, São João Hospital Centre, Porto, Portugal
| | - Adelino Leite-Moreira
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal.,Cardiovascular Research Centre, Porto, Portugal.,Cardiothoracic Surgery Department, São João Hospital Centre, Porto, Portugal
| | - Paulo Castro-Chaves
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal.,Cardiovascular Research Centre, Porto, Portugal.,Internal Medicine Department, São João Hospital Centre, Porto, Portugal
| |
Collapse
|
9
|
Chakraborty A, Pinar AA, Lam M, Bourke JE, Royce SG, Selomulya C, Samuel CS. Pulmonary myeloid cell uptake of biodegradable nanoparticles conjugated with an anti-fibrotic agent provides a novel strategy for treating chronic allergic airways disease. Biomaterials 2021; 273:120796. [PMID: 33894403 DOI: 10.1016/j.biomaterials.2021.120796] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 03/26/2021] [Accepted: 03/28/2021] [Indexed: 01/06/2023]
Abstract
Asthma (chronic allergic airways disease, AAD) is characterized by airway inflammation (AI), airway remodeling (AWR) and airway hyperresponsiveness (AHR). Current treatments for AAD mainly focus on targeting AI and its contribution AHR, with the use of corticosteroids. However, there are no therapies for the direct treatment of AWR, which can contribute to airway obstruction, AHR and corticosteroid resistance independently of AI. The acute heart failure drug, serelaxin (recombinant human gene-2 relaxin, RLX), has potential anti-remodeling and anti-fibrotic effects but only when continuously infused or injected to overcome its short half-life. To alleviate this limitation, we conjugated serelaxin to biodegradable and noninflammatory nanoparticles (NP-RLX) and evaluated their therapeutic potential on measures of AI, AWR and AHR, when intranasally delivered to a preclinical rodent model of chronic AAD and TGF-β1-stimulated collagen gel contraction from asthma patient-derived myofibroblasts. NP-RLX was preferentially taken-up by CD206+-infiltrating and CD68+-tissue resident alveolar macrophages. Furthermore, NP-RLX ameliorated the chronic AAD-induced AI, pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), chemokines (CCL2, CCL11) and the pro-fibrotic TGF-β1/IL-1β axis on AWR and resulting AHR, as well as human myofibroblast-induced collagen gel contraction, to a similar extent as unconjugated RLX. Hence, NP-RLX represents a novel strategy for treating the central features of asthma.
Collapse
Affiliation(s)
- Amlan Chakraborty
- Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia; Department of Chemical Engineering, Monash University, Clayton, Victoria, Australia
| | - Anita A Pinar
- Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Maggie Lam
- Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Jane E Bourke
- Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Simon G Royce
- Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia; Department of Clinical Pathology and Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - Cordelia Selomulya
- School of Chemical Engineering, UNSW Sydney, New South Wales, Australia.
| | - Chrishan S Samuel
- Monash Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia.
| |
Collapse
|
10
|
Romero G, Salama G. Relaxin abrogates genomic remodeling of the aged heart. VITAMINS AND HORMONES 2021; 115:419-448. [PMID: 33706957 DOI: 10.1016/bs.vh.2020.12.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
"Healthy" aging drives structural and functional changes in the heart including maladaptive electrical remodeling, fibrosis and inflammation, which lower the threshold for cardiovascular diseases such as heart failure (HF) and atrial fibrillation (AF). Despite mixed results in clinical trials, Relaxin-therapy for 2-days reduced mortality by 37% at 180-days post-treatment, in patients with acute decompensated HF. Relaxin's short lifespan (2-3h) but long-lasting protective actions suggested that relaxin acts at a genomic level to reverse maladaptive remodeling in AF, HF and aging. Our recent studies showed that a 2-week treatment with Relaxin (0.4mg/kg/day) of aged (24months old F-344 rats) increases the expression of voltage-gated Na+ channels (mRNA, Nav1.5 and INa), connexin-43, abrogates inflammatory and immune responses and reverses myocardial fibrosis and cellular hypertrophy of the aged hearts. Relaxin acts directly at a wide range of cell types in the cardiovascular system that express its cognate GPCR receptor, RXFP1. RNA-seq analysis of young and aged hearts with and without Relaxin treatment revealed that "normal" aging altered the expression of ~10% of genes expressed in the ventricles, including: ion channels, components of fibrosis, hemodynamic biomarkers, immune and inflammatory responses which were reversed by Relaxin. The extensive cardiovascular remodeling caused by Relaxin was mediated through the activation of the Wnt/β-catenin signaling pathway which was otherwise suppressed by in adult cardiomyocytes intracellular by cytosolic Dickkopf1 (Dkk1). Wnt/β-catenin signaling is a mechanism that can explain the pleiotropic actions of Relaxin and the marked reversal of genomic changes that occur in aged hearts.
Collapse
Affiliation(s)
- Guillermo Romero
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, United States.
| | - Guy Salama
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA, United States
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
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.
Collapse
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.
| |
Collapse
|
14
|
Dschietzig TB. Relaxin-2 for heart failure with preserved ejection fraction (HFpEF): Rationale for future clinical trials. Mol Cell Endocrinol 2019; 487:54-58. [PMID: 30659842 DOI: 10.1016/j.mce.2019.01.013] [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: 11/05/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 01/06/2023]
Abstract
Heart Failure with preserved Ejection Fraction (HFpEF), a distinct sub-entity of chronic heart failure characterized by generalized inflammatory non-compliance of the cardio-vascular system, is associated with high mortality and still an unmet medical need. Many novel and promising therapeutic approaches have failed in large studies. This review focuses on basic research, pre-clinical and clinical findings that may account for the potential benefit of relaxin-2 in HFpEF. The peptide combines short-term hemodynamic advantages, such as moderate blood pressure decline and functional endothelin-1 antagonism, with a wealth of protective effects harboring long-term benefits, such as anti-inflammatory, anti-fibrotic, and anti-oxidative actions. These pleiotropic effects are exerted through a complex and intricate signaling cascade involving the relaxin-family peptide receptor-1, the glucocorticoid receptor, the nitric oxide system, and a cell type-dependent variety of down-stream mediators.
Collapse
Affiliation(s)
- Thomas Bernd Dschietzig
- Relaxera Pharmazeutische Gesellschaft mbH & Co. KG, Stubenwald-Allee 8a, 64625, Bensheim, Germany.
| |
Collapse
|
15
|
Martin B, Romero G, Salama G. Cardioprotective actions of relaxin. Mol Cell Endocrinol 2019; 487:45-53. [PMID: 30625345 DOI: 10.1016/j.mce.2018.12.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/20/2018] [Accepted: 12/22/2018] [Indexed: 01/19/2023]
Abstract
Relaxin is a hormone of pregnancy first discovered for its ability to induce ligament relaxation in nonpregnant guinea pig and is important for softening of the birth canal during parturition, decidualization, implantation, nipple development and increased maternal renal perfusion, glomerular filtration, and cardiac output. Subsequently, relaxin has been shown to exert multiple beneficial cardiovascular effects during pathological events such as hypertension, atrial fibrillation, heart failure and myocardial infarction, including suppression of arrhythmia and inflammation, and reversal of fibrosis. Despite extensive studies, the mechanisms underlying relaxin's effects are not well understood. Relaxin signals primarily through its G protein coupled receptor, the relaxin family peptide receptor-1, to activate multiple signaling pathways and this review summarizes our understanding of these pathways as they relate to the cardioprotective actions of relaxin, focusing on relaxin's anti-fibrotic, anti-arrhythmic and anti-inflammatory properties. Further, this review includes a brief overview of relaxin in clinical trials for heart failure and progress in the development of relaxin mimetics.
Collapse
Affiliation(s)
- Brian Martin
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15261, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Guillermo Romero
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15261, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Guy Salama
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
| |
Collapse
|
16
|
Affiliation(s)
- Shoichi Kageyama
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA
| | - Kojiro Nakamura
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA
| | - Jerzy W Kupiec-Weglinski
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA.
| |
Collapse
|
17
|
Kageyama S, Nakamura K, Kupiec-Weglinski JW. Relaxin in liver transplantation: A personal perspective. Mol Cell Endocrinol 2019; 482:57-61. [PMID: 30550815 PMCID: PMC7427537 DOI: 10.1016/j.mce.2018.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 12/04/2018] [Accepted: 12/11/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Shoichi Kageyama
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA
| | - Kojiro Nakamura
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA
| | - Jerzy W Kupiec-Weglinski
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at University of California, Los Angeles, CA, 90095, USA.
| |
Collapse
|
18
|
Receptor-independent modulation of TGF-β-induced pro-fibrotic pathways by relaxin-2 in human primary tubular epithelial cells. Cell Tissue Res 2018; 374:619-627. [PMID: 30078103 DOI: 10.1007/s00441-018-2904-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
Abstract
Renal tubular epithelial cells actively contribute to the development of renal fibrosis and may be targeted by anti-fibrotic drugs. Relaxin-2 (RLX2) applied as recombinant protein is suggested to be renoprotective. Therefore, we investigated whether human primary tubular epithelial cells (hPTEC) obtained from various donors were target cells for the anti-fibrotic actions of RLX2. Treatment of hPTEC with RLX2 reduced the TGF-β1-induced secretion of the pro-fibrotic factor CTGF (connective tissue growth factor) and inhibited fibronectin synthesis and secretion. Furthermore, metalloproteinase MMP2 secretion was increased, with no effect on MMP9. Considerable differences were observed between hPTEC obtained from different donors. Therefore, expression of the relaxin family peptide receptor RXFP1, the major mediator of renal RLX2 effects, was analyzed. A validated antibody detected a double band of 80-90 kDa in cellular homogenates by Western blotting. Expression of the detected protein was not altered by incubation with TGF-β1 and RLX2-induced modulation of CTGF expression did not correlate with the putative receptor expression. Therefore, relaxin family receptors RXFP1-4 were assessed by RNA-seq analysis. No evidence was found for mRNA expression of any of these receptors in several hPTEC preparations. Lack of RXFP1 mRNA was confirmed by qPCR using mRNA obtained from THP-1 cells as positive control. Our data thus provide evidence for primary renal human tubular epithelial cells as targets for the anti-fibrotic actions of RLX2. However, anti-fibrotic effects were observed at micromolar concentrations of RLX2 and shown to be independent of RXFP1 expression.
Collapse
|
19
|
Bathgate RA, Kocan M, Scott DJ, Hossain MA, Good SV, Yegorov S, Bogerd J, Gooley PR. The relaxin receptor as a therapeutic target – perspectives from evolution and drug targeting. Pharmacol Ther 2018; 187:114-132. [DOI: 10.1016/j.pharmthera.2018.02.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
20
|
Kageyama S, Nakamura K, Fujii T, Ke B, Sosa RA, Reed EF, Datta N, Zarrinpar A, Busuttil RW, Kupiec-Weglinski JW. Recombinant relaxin protects liver transplants from ischemia damage by hepatocyte glucocorticoid receptor: From bench-to-bedside. Hepatology 2018; 68:258-273. [PMID: 29350771 PMCID: PMC6033647 DOI: 10.1002/hep.29787] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 12/09/2017] [Accepted: 01/12/2018] [Indexed: 12/18/2022]
Abstract
UNLABELLED Hepatic ischemia-reperfusion injury (IRI) represents a major risk factor of early graft dysfunction and acute/chronic rejection as well as a key obstacle to expanding the donor pool in orthotopic liver transplantation (OLT). Although glucocorticoid receptor (GR) signaling may enhance cytoprotective programs, clinical use of glucocorticoid is limited because of adverse effects, whereas clinical relevance of GR-facilitated cytoprotection in OLT remains unknown. We aimed to evaluate the significance of hepatic GR in clinical OLT and verify the impact of recombinant human relaxin (rhRLX), which may function as a GR agonist in a tissue/disease-specific manner. Fifty-one OLT patients were recruited under an institutional research board (IRB) protocol. Liver biopsies were collected after cold storage (presurgery) and 2 hours postreperfusion (before abdominal closure), followed by western blotting-assisted hepatic analyses. Forty-three percent of OLTs failed to increase GR perioperatively under surgical stress. Post-/pre-GR ratios at postoperative day 1 correlated negatively with serum aspartate aminotransferase (AST)/cleaved caspase-3 and positively with B-cell lymphoma-extra large (Bcl-xL)/B-cell lymphoma 2 (Bcl-2) levels. In a murine OLT model with extended (18-hour) cold storage, treatment with rhRLX ameliorated ischemia-reperfusion (IR) damage and improved survival while up-regulating hepatocyte GR and Bcl-xL/Bcl-2 expression in OLT. rhRLX-induced GR suppressed hepatocyte high-mobility group box 1 (HMGB1) translocation/release, accompanied by decreased Toll-like receptor 4 (TLR4)/receptor for advanced glycation end products (RAGE), suppressed interleukin 1 beta (IL1β), chemokine (C-C motif) ligand 2 (CCL2), C-X-C motif chemokine (CXCL)10, tumor necrosis factor alpha (TNFα), CXCL1, and CXCL2 levels, and attenuated neutrophil/macrophage accumulation in OLT. Inhibition of GR in hepatocyte culture and in OLT diminished rhRLX-mediated cytoprotection. CONCLUSION This translational study underscores the role of rhRLX-GR signaling as a regulator of hepatocellular protection against IR stress in OLT. In the context of a recent phase III clinical trial demonstrating positive outcomes of rhRLX in patients with acute heart failure, studies on rhRLX for the management of IRI in OLT recipients are warranted. (Hepatology 2018;68:258-273).
Collapse
Affiliation(s)
- Shoichi Kageyama
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Kojiro Nakamura
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Takehiro Fujii
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Bibo Ke
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Rebecca A Sosa
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at University of California, Los Angeles, CA 90095
| | - Elaine F. Reed
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at University of California, Los Angeles, CA 90095
| | - Nakul Datta
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Ali Zarrinpar
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Ronald W. Busuttil
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| | - Jerzy W. Kupiec-Weglinski
- The Dumont-UCLA Transplant Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, CA 90095
| |
Collapse
|
21
|
Ng HH, Leo CH, Parry LJ, Ritchie RH. Relaxin as a Therapeutic Target for the Cardiovascular Complications of Diabetes. Front Pharmacol 2018; 9:501. [PMID: 29867503 PMCID: PMC5962677 DOI: 10.3389/fphar.2018.00501] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/26/2018] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular complications are the major cause of mortality in patients with diabetes. This is closely associated with both macrovascular and microvascular complications of diabetes, which lead to organ injuries in diabetic patients. Previous studies have consistently demonstrated the beneficial effects of relaxin treatment for protection of the vasculature, with evidence of antioxidant and anti-remodeling actions. Relaxin enhances nitric oxide, prostacyclin and endothelium-derived hyperpolarization (EDH)-type-mediated relaxation in various vascular beds. These effects of relaxin on the systemic vasculature, coupled with its cardiac actions, reduce pulmonary capillary wedge pressure and pulmonary artery pressure. This results in an overall decrease in systemic and pulmonary vascular resistance in heart failure patients. The anti-fibrotic actions of relaxin are well established, a desirable property in the context of diabetes. Further, relaxin ameliorates diabetic wound healing, with accelerated angiogenesis and vasculogenesis. Relaxin-mediated stimulation of vascular endothelial growth factor (VEGF) and stromal cell-derived factor 1-α, as well as regulation of metalloproteinase expression, ameliorates cardiovascular fibrosis in diabetic mice. In the heart, relaxin is a cardioprotective molecule in several experimental animal models, exerting anti-fibrotic, anti-hypertrophy and anti-apoptotic effects in diabetic pathologies. Collectively, these studies provide a foundation to propose the therapeutic potential for relaxin as an adjunctive agent in the prevention or treatment of diabetes-induced cardiovascular complications. This review provides a comprehensive overview of the beneficial effects of relaxin, and identifies its therapeutic possibilities for alleviating diabetes-related cardiovascular injury.
Collapse
Affiliation(s)
- Hooi Hooi Ng
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Chen Huei Leo
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Science and Math Cluster, Singapore University of Technology and Design, Singapore, Singapore
| | - Laura J. Parry
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Rebecca H. Ritchie
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology & Therapeutics, The University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
22
|
Lam M, Royce SG, Samuel CS, Bourke JE. Serelaxin as a novel therapeutic opposing fibrosis and contraction in lung diseases. Pharmacol Ther 2018; 187:61-70. [PMID: 29447958 DOI: 10.1016/j.pharmthera.2018.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The most common therapies for asthma and other chronic lung diseases are anti-inflammatory agents and bronchodilators. While these drugs oppose disease symptoms, they do not reverse established structural changes in the airways and their therapeutic efficacy is reduced with increasing disease severity. The peptide hormone, relaxin, is a Relaxin Family Peptide Receptor 1 (RXFP1) receptor agonist with unique combined effects in the lung that differentiates it from these existing therapies. Relaxin has previously been reported to have cardioprotective effects in acute heart failure as well anti-fibrotic actions in several organs. This review focuses on recent experimental evidence of the beneficial effects of chronic relaxin treatment in animal models of airways disease demonstrating inhibition of airway hyperresponsiveness and reversal of established fibrosis, consistent with potential therapeutic benefit. Of particular interest, accumulating evidence demonstrates that relaxin can also acutely oppose contraction by reducing the release of mast cell-derived bronchoconstrictors and by directly eliciting bronchodilation. When used in combination, chronic and acute treatment with relaxin has been shown to enhance responsiveness to both glucocorticoids and β2-adrenoceptor agonists respectively. While the mechanisms underlying these beneficial actions remain to be fully elucidated, translation of these promising combined preclinical findings is critical in the development of relaxin as a novel alternative or adjunct therapeutic opposing multiple aspects of airway pathology in lung diseases.
Collapse
Affiliation(s)
- Maggie Lam
- Biomedicine Discovery Institute, Monash University, Melbourne, Australia; Department of Pharmacology, School of Biomedical Sciences, Monash University, Melbourne, Australia
| | - Simon G Royce
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia
| | - Chrishan S Samuel
- Biomedicine Discovery Institute, Monash University, Melbourne, Australia; Department of Pharmacology, School of Biomedical Sciences, Monash University, Melbourne, Australia
| | - Jane E Bourke
- Biomedicine Discovery Institute, Monash University, Melbourne, Australia; Department of Pharmacology, School of Biomedical Sciences, Monash University, Melbourne, Australia.
| |
Collapse
|
23
|
Sarwar M, Du XJ, Dschietzig TB, Summers RJ. The actions of relaxin on the human cardiovascular system. Br J Pharmacol 2016; 174:933-949. [PMID: 27239943 DOI: 10.1111/bph.13523] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/01/2016] [Accepted: 04/26/2016] [Indexed: 12/14/2022] Open
Abstract
The insulin-like peptide relaxin, originally identified as a hormone of pregnancy, is now known to exert a range of pleiotropic effects including vasodilatory, anti-fibrotic, angiogenic, anti-apoptotic and anti-inflammatory effects in both males and females. Relaxin produces these effects by binding to a cognate receptor RXFP1 and activating a variety of signalling pathways including cAMP, cGMP and MAPKs as well as by altering gene expression of TGF-β, MMPs, angiogenic growth factors and endothelin receptors. The peptide has been shown to be effective in halting or reversing many of the adverse effects including fibrosis in animal models of cardiovascular disease including ischaemia/reperfusion injury, myocardial infarction, hypertensive heart disease and cardiomyopathy. Relaxin given to humans is safe and produces favourable haemodynamic changes. Serelaxin, the recombinant form of relaxin, is now in extended phase III clinical trials for the treatment of acute heart failure. Previous clinical studies indicated that a 48 h infusion of relaxin improved 180 day mortality, yet the mechanism underlying this effect is not clear. This article provides an overview of the cellular mechanism of effects of relaxin and summarizes its beneficial actions in animal models and in the clinic. We also hypothesize potential mechanisms for the clinical efficacy of relaxin, identify current knowledge gaps and suggest new ways in which relaxin could be useful therapeutically. 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.
Collapse
Affiliation(s)
- Mohsin Sarwar
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Australia
| | - Xiao-Jun Du
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Thomas B Dschietzig
- Immundiagnostik AG, Bensheim, Germany.,Campus Mitte, Medical Clinic for Cardiology and Angiology, Charité-University Medicine Berlin, Berlin, Germany.,Relaxera Pharmazeutische Gesellschaft mbH & Co. KG, Bensheim, Germany
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Australia
| |
Collapse
|
24
|
|
25
|
Patel KP, Giraud AS, Samuel CS, Royce SG. Combining an epithelial repair factor and anti-fibrotic with a corticosteroid offers optimal treatment for allergic airways disease. Br J Pharmacol 2016; 173:2016-29. [PMID: 27060978 DOI: 10.1111/bph.13494] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/21/2016] [Accepted: 03/23/2016] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE We evaluated the extent to which individual versus combination treatments that specifically target airway epithelial damage [trefoil factor-2 (TFF2)], airway fibrosis [serelaxin (RLX)] or airway inflammation [dexamethasone (DEX)] reversed the pathogenesis of chronic allergic airways disease (AAD). EXPERIMENTAL APPROACH Following induction of ovalbumin (OVA)-induced chronic AAD in 6–8 week female Balb/c mice, animals were i.p. administered naphthalene (NA) on day 64 to induce epithelial damage, then received daily intranasal administration of RLX (0.8 mg·mL(−1)), TFF2 (0.5 mg·mL(−1)), DEX (0.5 mg·mL(−1)), RLX + TFF2 or RLX + TFF2 + DEX from days 67–74. On day 75, lung function was assessed by invasive plethysmography, before lung tissue was isolated for analyses of various measures. The control group was treated with saline + corn oil (vehicle for NA). KEY RESULTS OVA + NA-injured mice demonstrated significantly increased airway inflammation, airway remodelling (AWR) (epithelial damage/thickness; subepithelial myofibroblast differentiation, extracellular matrix accumulation and fibronectin deposition; total lung collagen concentration), and significantly reduced airway dynamic compliance (cDyn). RLX + TFF2 markedly reversed several measures of OVA + NA-induced AWR and normalized the reduction in cDyn. The combined effects of RLX + TFF2 + DEX significantly reversed peribronchial inflammation score, airway epithelial damage, subepithelial extracellular matrix accumulation/fibronectin deposition and total lung collagen concentration (by 50–90%) and also normalized the reduction of cDyn. CONCLUSIONS AND IMPLICATIONS Combining an epithelial repair factor and anti-fibrotic provides an effective means of treating the AWR and dysfunction associated with AAD/asthma and may act as an effective adjunct therapy to anti-inflammatory corticosteroids
Collapse
Affiliation(s)
- K P Patel
- Fibrosis Laboratory, Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Vic., Australia
| | - A S Giraud
- Murdoch Children's Research Institute, University of Melbourne, Vic., Australia.,Department of Paediatrics, University of Melbourne, Vic., Australia
| | - C S Samuel
- Fibrosis Laboratory, Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Vic., Australia
| | - S G Royce
- Fibrosis Laboratory, Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Vic., Australia.,Respiratory Pharmacology Laboratory, Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Vic., Australia
| |
Collapse
|
26
|
Zhou H, Qu X, Gao Z, Zheng G, Lin J, Su L, Huang Z, Li H, Huang W. Relaxin Level in Patients With Atrial Fibrillation and Association with Heart Failure Occurrence: A STROBE Compliant Article. Medicine (Baltimore) 2016; 95:e3664. [PMID: 27227926 PMCID: PMC4902350 DOI: 10.1097/md.0000000000003664] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia requiring medical treatment and has been associated with enhanced atrial fibrosis and heart failure (HF). Relaxin (RLX), an antifibrosis and antiinflammatory peptide hormone, may be used to evaluate atrial fibrosis and is associated with HF occurrence in AF. We aimed to clarify the clinical significance of RLX level in patients with AF.We measured circulating levels of RLX and other fibrosis-related factors in 311 patients with sinus rhythm (SR; n = 116) or AF (n = 195). All discharged AF patients were followed up for the occurrence of HF for a mean of 6 months.Circulating levels of RLX were significantly different in patients with AF as compared with SR (P < 0.001), and in the subgroup analysis of AF. RLX level was correlated with left atrial diameter (LAD; R = 0.358, P < 0.001). Among followed up AF patients, on Kaplan-Meier curve analysis, patients with the third RLX tertile (T3) had a significantly higher HF rate than those with the 1st tertile (T1) (P = 0.002) and the cut-off value was 294.8 ng/L (area under the ROC curve [AUC] = 0.723). On multivariable analysis, HF occurrence with AF was associated with increased tertile of serum RLX level (odds ratio [OR] 2.659; confidence interval [95% CI] 1.434-4.930; P = 0.002).RLX is associated with fibrosis-related biomarkers and significantly elevated in AF. RLX was related to the HF occurrence in patients with AF.
Collapse
Affiliation(s)
- Hao Zhou
- From the Department of Cardiovascular Medicine, the First Affiliated Hospital of Wenzhou Medical University; The Key Lab of Cardiovascular Disease of Wenzhou, Wenzhou, China
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Dschietzig TB, Krause-Relle K, Hennequin M, von Websky K, Rahnenführer J, Ruppert J, Grön HJ, Armbruster FP, Bathgate RAD, Aschenbach JR, Forssmann WG, Hocher B. Relaxin-2 does not ameliorate nephropathy in an experimental model of type-1 diabetes. Kidney Blood Press Res 2016; 40:77-88. [PMID: 25791819 DOI: 10.1159/000368484] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS In diabetic nephropathy (DN), the current angiotensin-II-blocking pharmacotherapy is frequently failing. For diabetic cardiomyopathy (DC), there is no specific remedy available. Relaxin-2 (Rlx) - an anti-fibrotic, anti-inflammatory, and vasoprotecting peptide – is a candidate drug for both. METHODS Low-dose (32 μg/kg/day) and high-dose (320 μg/kg/day) Rlx were tested against vehicle (n = 20 each) and non-diabetic controls (n = 14) for 12 weeks in a model of type-1 diabetes induced in endothelial nitric oxide synthase knock-out (eNOS-KO) mice by intraperitoneal injection of streptozotocin. RESULTS Diabetic animals showed normal plasma creatinine, markedly increased albuminuria and urinary malonyldialdehyde, elevated relative kidney weight, glomerulosclerosis, and increased glomerular size, but no relevant interstitial fibrosis. Neither dose of Rlx affected these changes although the drug was active and targeted plasma levels were achieved. Of note, we found no activation of the renal TGF-β pathway in this model. In the hearts of diabetic animals, no fibrotic alterations indicative of DC could be determined which precluded testing of the initial hypothesis. CONCLUSIONS We investigated a model showing early DN without overt tubulointerstitial fibrosis and activation of the TGF-β-Smad-2/3 pathway. In this model, Rlx proved ineffective; however, the same may not apply to other models and types of diabetes.
Collapse
|
28
|
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.
Collapse
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.)
| |
Collapse
|
29
|
Dschietzig TB. Recombinant human relaxin-2: (how) can a pregnancy hormone save lives in acute heart failure? Am J Cardiovasc Drugs 2014; 14:343-55. [PMID: 24934696 DOI: 10.1007/s40256-014-0078-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Acute heart failure (AHF) syndrome, characterized by pulmonary and/or venous congestion owing to increased cardiac filling pressures with or without diminished cardiac output, is still associated with high post-discharge mortality and hospitalization rates. Many novel and promising therapeutic approaches, among them endothelin-1, vasopressin and adenosine antagonists, calcium sensitization, and recombinant B-type natriuretic hormone, have failed in large studies. Likewise, the classic drugs, vasodilators, diuretics, and inotropes, have never been shown to lower mortality.The phase III trial RELAX-AHF tested recombinant human relaxin-2 (rhRlx) and found it to improve clinical symptoms moderately, to be neutral regarding the combination of death and hospitalization at day 60, to be safe, and to lower mortality at day 180. This review focuses on basic research and pre-clinical findings that may account for the benefit of rhRlx in AHF. The drug combines short-term hemodynamic advantages, such as moderate blood pressure decline and functional endothelin-1 antagonism, with a wealth of protective effects harboring long-term benefits, such as anti-inflammatory, anti-fibrotic, and anti-oxidative actions. These pleiotropic effects are exerted through a complex and intricate signaling cascade involving the relaxin-family peptide receptor-1, the glucocorticoid receptor, nitric oxide, and a cell type-dependent variety of kinases and transcription factors.
Collapse
|
30
|
Novel drug mechanisms in development for heart failure. Pflugers Arch 2014; 466:1219-25. [DOI: 10.1007/s00424-014-1528-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 04/23/2014] [Indexed: 01/10/2023]
|
31
|
Alexiou K, Wilbring M, Matschke K, Dschietzig T. Relaxin protects rat lungs from ischemia-reperfusion injury via inducible NO synthase: role of ERK-1/2, PI3K, and forkhead transcription factor FKHRL1. PLoS One 2013; 8:e75592. [PMID: 24098703 PMCID: PMC3787055 DOI: 10.1371/journal.pone.0075592] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 08/19/2013] [Indexed: 01/03/2023] Open
Abstract
INTRODUCTION Early allograft dysfunction following lung transplantation is mainly an ischemia/reperfusion (IR) injury. We showed that relaxin-2 (relaxin) exerts a protective effect in lung IR, attributable to decreases in endothelin-1 (ET-1) production, leukocyte recruitment, and free radical generation. Here, we summarize our investigations into relaxin's signalling. MATERIALS AND METHODS Isolated rat lungs were perfused with vehicle or 5 nM relaxin (n = 6-10 each). Thereafter, experiments were conducted in the presence of relaxin plus vehicle, the protein kinase A inhibitors H-89 and KT-5720, the NO synthase (NOS) inhibitor L-NAME, the iNOS inhibitor 1400W, the nNOS inhibitor SMTC, the extracellular signal-regulated kinase-1/2 (ERK-1/2) inhibitor PD-98059, the phosphatidylinositol-3 kinase (PI3K) inhibitor wortmannin, the endothelin type-B (ETB) antagonist A-192621, or the glucocorticoid receptor (GR) antagonist RU-486. After 90 min ischemia and 90 min reperfusion we determined wet-to-dry (W/D) weight ratio, mean pulmonary arterial pressure (MPAP), vascular release of ET-1, neutrophil elastase (NE), myeloperoxidase (MPO), and malondialdehyde (MDA). Primary rat pulmonary vascular cells were similarly treated. RESULTS IR lungs displayed significantly elevated W/D ratios, MPAP, as well as ET-1, NE, MDA, and MPO. In the presence of relaxin, all of these parameters were markedly improved. This protective effect was completely abolished by L-NAME, 1400W, PD-98059, and wortmannin whereas neither PKA and nNOS inhibition nor ETB and GR antagonism were effective. Analysis of NOS gene expression and activity revealed that the relaxin-induced early and moderate iNOS stimulation is ERK-1/2-dependent and counter-balanced by PI3K. Relaxin-PI3K-related phosphorylation of a forkhead transcription factor, FKHRL1, paralleled this regulation. In pulmonary endothelial and smooth muscle cells, FKHRL1 was essential to relaxin-PI3K signalling towards iNOS. CONCLUSION In this short-time experimental setting, relaxin protects against IR-induced lung injury via early and moderate iNOS induction, dependent on balanced ERK-1/2 and PI3K-FKHRL1 stimulation. These findings render relaxin a candidate drug for lung preservation.
Collapse
Affiliation(s)
- Konstantin Alexiou
- University Heart Center Dresden, Department of Cardiac Surgery, Dresden, Germany
- * E-mail:
| | - Manuel Wilbring
- University Heart Center Dresden, Department of Cardiac Surgery, Dresden, Germany
| | - Klaus Matschke
- University Heart Center Dresden, Department of Cardiac Surgery, Dresden, Germany
| | - Thomas Dschietzig
- Immundiagnostik AG, Bensheim, Germany
- Charité-University of Medicine Berlin (Campus Mitte), Department of Cardiology and Angiology, Berlin, Germany
| |
Collapse
|
32
|
Collino M, Rogazzo M, Pini A, Benetti E, Rosa AC, Chiazza F, Fantozzi R, Bani D, Masini E. Acute treatment with relaxin protects the kidney against ischaemia/reperfusion injury. J Cell Mol Med 2013; 17:1494-505. [PMID: 24079335 PMCID: PMC4117562 DOI: 10.1111/jcmm.12120] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 07/24/2013] [Indexed: 12/11/2022] Open
Abstract
Although recent preclinical and clinical studies have demonstrated that recombinant human relaxin (rhRLX) may have important therapeutic potential in acute heart failure and chronic kidney diseases, the effects of acute rhRLX administration against renal ischaemia/reperfusion (I/R) injury have never been investigated. Using a rat model of 1-hr bilateral renal artery occlusion followed by 6-hr reperfusion, we investigated the effects of rhRLX (5 μg/Kg i.v.) given both at the beginning and after 3 hrs of reperfusion. Acute rhRLX administration attenuated the functional renal injury (increase in serum urea and creatinine), glomerular dysfunction (decrease in creatinine clearance) and tubular dysfunction (increase in urinary excretion of N-acetyl-β-glucosaminidase) evoked by renal I/R. These beneficial effects were accompanied by a significant reduction in local lipid peroxidation, free radical-induced DNA damage and increase in the expression/activity of the endogenous antioxidant enzymes MnSOD and CuZnSOD superoxide dismutases (SOD). Furthermore, rhRLX administration attenuated the increase in leucocyte activation, as suggested by inhibition of myeloperoxidase activity, intercellular-adhesion-molecule-1 expression, interleukin (IL)-1β, IL-18 and tumour necrosis factor-α production as well as increase in IL-10 production. Interestingly, the reduced oxidative stress status and neutrophil activation here reported were associated with rhRLX-induced activation of endothelial nitric oxide synthase and up-regulation of inducible nitric oxide synthase, possibly secondary to activation of Akt and the extracellular signal-regulated protein kinase (ERK) 1/2, respectively. Thus, we report herein that rhRLX protects the kidney against I/R injury by a mechanism that involves changes in nitric oxide signalling pathway.
Collapse
Affiliation(s)
- Massimo Collino
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Heart failure is an important public health problem that is increasing in prevalence throughout the world. Not only is this condition common, but it is associated with significant morbidity and mortality as well as high costs to medical care systems. Vasodilator drugs help unload the heart and may have other effects that could benefit heart failure patients. Consequently, they have emerged as an important therapeutic approach for patients with this condition. Novel vasodilator therapies that are currently in development target new pathways, potentially giving clinicians alternate options for improving outcomes in this vulnerable population. This review focuses on investigational drugs that have the ability to dilate blood vessels amongst their therapeutic properties. These drugs include the natriuretic peptides that activate particulate guanylate cyclase, the novel agent cinaciguat that activates the soluble guanylate cyclase system, and finally a recombinant form of the naturally occurring vasodilating agent relaxin, a hormone that mediates many of the changes that allows the cardiovascular system to successfully adapt to pregnancy.
Collapse
|
34
|
Bathgate RAD, Halls ML, van der Westhuizen ET, Callander GE, Kocan M, Summers RJ. Relaxin family peptides and their receptors. Physiol Rev 2013; 93:405-80. [PMID: 23303914 DOI: 10.1152/physrev.00001.2012] [Citation(s) in RCA: 376] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
There are seven relaxin family peptides that are all structurally related to insulin. Relaxin has many roles in female and male reproduction, as a neuropeptide in the central nervous system, as a vasodilator and cardiac stimulant in the cardiovascular system, and as an antifibrotic agent. Insulin-like peptide-3 (INSL3) has clearly defined specialist roles in male and female reproduction, relaxin-3 is primarily a neuropeptide involved in stress and metabolic control, and INSL5 is widely distributed particularly in the gastrointestinal tract. Although they are structurally related to insulin, the relaxin family peptides produce their physiological effects by activating a group of four G protein-coupled receptors (GPCRs), relaxin family peptide receptors 1-4 (RXFP1-4). Relaxin and INSL3 are the cognate ligands for RXFP1 and RXFP2, respectively, that are leucine-rich repeat containing GPCRs. RXFP1 activates a wide spectrum of signaling pathways to generate second messengers that include cAMP and nitric oxide, whereas RXFP2 activates a subset of these pathways. Relaxin-3 and INSL5 are the cognate ligands for RXFP3 and RXFP4 that are closely related to small peptide receptors that when activated inhibit cAMP production and activate MAP kinases. Although there are still many unanswered questions regarding the mode of action of relaxin family peptides, it is clear that they have important physiological roles that could be exploited for therapeutic benefit.
Collapse
Affiliation(s)
- R A D Bathgate
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology, Monash University, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
35
|
Cernaro V, Lacquaniti A, Lupica R, Buemi A, Trimboli D, Giorgianni G, Bolignano D, Buemi M. Relaxin: new pathophysiological aspects and pharmacological perspectives for an old protein. Med Res Rev 2013; 34:77-105. [PMID: 23401142 DOI: 10.1002/med.21277] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Human relaxin-2 (hereafter simply defined as "relaxin") is a 6-kDa peptidic hormone best known for the physiological role played during pregnancy in the growth and differentiation of the reproductive tract and in the renal and systemic hemodynamic changes. This factor can also be involved in the pathophysiology of arterial hypertension and heart failure, in the molecular pathways of fibrosis and cancer, and in angiogenesis and bone remodeling. It belongs to the relaxin peptide family, whose members comprehensively exert numerous effects through interaction with different types of receptors, classified as relaxin family peptide (RXFP) receptors (RXFP1, RXFP2, RXFP3, RXFP4). Research looks toward the in-depth examination and complete understanding of relaxin in its various pleiotropic actions. The intent is to evaluate the likelihood of employing this substance for therapeutic purposes, for instance in diseases where a deficit could be part of the underlying pathophysiological mechanisms, also avoiding any adverse effect. Relaxin is already being considered as a promising drug, especially in acute heart failure. A careful study of the different RXFPs and their receptors and the comprehension of all biological activities of these hormones will probably provide new drugs with a potential wide range of therapeutic applications in the near future.
Collapse
Affiliation(s)
- Valeria Cernaro
- Department of Internal Medicine, University of Messina, Via Consolare Valeria, 1, 98100, Italy
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Combination therapy with relaxin and methylprednisolone augments the effects of either treatment alone in inhibiting subepithelial fibrosis in an experimental model of allergic airways disease. Clin Sci (Lond) 2012; 124:41-51. [PMID: 22817662 DOI: 10.1042/cs20120024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although CSs (corticosteroids) demonstrate potent effects in the control of airway inflammation in asthma, many patients continue to experience symptoms and AHR (airway hyper-responsiveness) despite optimal treatment with these agents, probably due to progressive airway remodelling. Identifying novel therapies that can target airway remodelling and/or airway reactivity may improve symptom control in these patients. We have demonstrated previously that the anti-fibrotic hormone RLN (relaxin) can reverse airway remodelling (epithelial thickening and subepithelial fibrosis) and AHR in a murine model of AAD (allergic airways disease). In the present study, we compared the effects of RLN with a CS (methylprednisolone) on airway remodelling and AHR when administered independently or in combination in the mouse AAD model. Female mice at 6-8 weeks of age were sensitized and challenged to OVA (ovalbumin) over a 9-week period and treated with methylprednisolone, RLN, a combination of both treatments or vehicle controls. Methylprednisolone was administered intraperitoneally on the same day as nebulization for 6 weeks, whereas recombinant human RLN-2 was administered via subcutaneously implanted osmotic mini-pumps from weeks 9-11. RLN or methylprednisolone alone were both able to significantly decrease subepithelial thickness and total lung collagen deposition; whereas RLN but not methylprednisolone significantly decreased epithelial thickness and AHR. Additionally, combination therapy with CS and RLN more effectively reduced subepithelial collagen thickness than either therapy alone. These findings demonstrate that RLN can modulate a broader range of airway remodelling changes and AHR than methylprednisolone and the combination of both treatments offers enhanced control of subepithelial fibrosis.
Collapse
|
37
|
Dschietzig T, Brecht A, Bartsch C, Baumann G, Stangl K, Alexiou K. Relaxin improves TNF-α-induced endothelial dysfunction: the role of glucocorticoid receptor and phosphatidylinositol 3-kinase signalling. Cardiovasc Res 2012; 95:97-107. [PMID: 22510373 DOI: 10.1093/cvr/cvs149] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Human relaxin-2 influences renal and cardiovascular functions. We investigated its effects on experimental endothelial dysfunction. METHODS AND RESULTS Acetylcholine-mediated vasodilation of rat aortic rings, impaired by 48 h tumour necrosis factor-α (TNF-α) treatment, was dose-dependently improved by relaxin co-incubation, an effect sensitive to phosphatidylinositol 3-kinase (PI3K) inhibition and the glucocorticoid receptor (GR) antagonist RU-486. TNF increased endothelial nitric oxide synthase (eNOS) phosphorylation at Thr495 and decreased total eNOS expression and both basal and stimulated eNOS activity. Relaxin co-incubation did not affect eNOS expression but improved its activity via PI3K-dependent Thr495 dephosphorylation and Ser1177 phosphorylation, and additional Ser633 phosphorylation. Via GR, relaxin attenuated the TNF-related stimulation of endothelin-1 expression, superoxide and nitrotyrosine formation, and arginase II expression. Relaxin restored, via GR-CCAAT/enhancer-binding protein-β (c/EBP-β)-mediated promoter stimulation, the compromised expression of superoxide dismutase-1 (SOD1). In rat aortic endothelial cells, relaxin activated protein kinase B (Akt) and repressed TNF-induced nuclear factor-κB and activator protein-1. Finally, the relevance of the different findings to the model used was proved by pharmacological interventions. CONCLUSION Relaxin improved endothelial dysfunction by promoting eNOS activity, suppressing endothelin-1 and arginase-II expression, and up-regulating SOD1 via GR, GR-c/EBP-β, and PI3K-Akt pathways. This corroborates the notion that it functions as an endogenous and potentially therapeutic vasoprotector.
Collapse
|
38
|
Royce SG, Cheng V, Samuel CS, Tang MLK. The regulation of fibrosis in airway remodeling in asthma. Mol Cell Endocrinol 2012; 351:167-75. [PMID: 22266540 DOI: 10.1016/j.mce.2012.01.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 01/04/2012] [Indexed: 01/12/2023]
Abstract
Fibrosis is one of the key pathological features of airway remodeling in asthma. In the normal airway the amount of collagen and other extracellular matrix components is kept in equilibrium by regulation of synthesis and degradation. In asthma this homeostasis is disrupted due to genetic and environmental factors. In the airways of patients with the disease there is increased extracellular matrix deposition, particularly in the reticular basement membrane region, lamina propria and submucosa. Fibrosis is important as it can occur early in the pathogenesis of asthma, be associated with severity and resistant to therapy. In this review we will discuss current knowledge of relaxin and other key regulators of fibrosis in the airway including TGFβ, Smad2/3 and matrix metalloproteinases. As fibrosis is not directly targeted or effectively treated by current asthma drugs including corticosteroids, characterization of airway fibrosis and how it is regulated will be essential for the development of novel therapies for asthma.
Collapse
Affiliation(s)
- Simon G Royce
- Department of Allergy and Immunology, Murdoch Children's Research Institute, The Royal Children's Hospital, Melbourne 3052, Australia
| | | | | | | |
Collapse
|
39
|
Vandevyver S, Dejager L, Libert C. On the trail of the glucocorticoid receptor: into the nucleus and back. Traffic 2011; 13:364-74. [PMID: 21951602 DOI: 10.1111/j.1600-0854.2011.01288.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/20/2011] [Accepted: 09/20/2011] [Indexed: 01/20/2023]
Abstract
The glucocorticoid receptor (GR) belongs to the superfamily of steroid receptors and is an important regulator of physiological and metabolic processes. In its inactive state, GR is unbound by ligand and resides in the cytoplasm in a chaperone complex. When it binds glucocorticoids, it is activated and translocates to the nucleus, where it functions as a transcription factor. However, the subcellular localization of GR is determined by the balance between its rates of nuclear import and export. The mechanism of GR nuclear transport has been extensively studied. Originally, it was believed that nuclear import of GR is initiated by dissociation of the chaperone complex in the cytoplasm. However, several studies show that the chaperone machinery is required for nuclear transport of GR. In this review, we summarize the contribution of various chaperone components involved in the nuclear transport of GR and propose an updated model of its nuclear import and export. Moreover, we review the importance of ligand-independent nuclear transport and compare the nuclear transport of GR with that of other steroid receptors.
Collapse
Affiliation(s)
- Sofie Vandevyver
- Department of Molecular Biomedical Research, VIB, Ghent University, FSVM Building, Technologiepark 927, B9052, Ghent, Belgium
| | | | | |
Collapse
|
40
|
Horton JS, Yamamoto SY, Bryant-Greenwood GD. Relaxin modulates proinflammatory cytokine secretion from human decidual macrophages. Biol Reprod 2011; 85:788-97. [PMID: 21734258 DOI: 10.1095/biolreprod.110.089201] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Relaxin (RLN) is a systemic hormone from the corpus luteum, and its levels remain low during normal human gestation. Indeed, elevation of circulating RLN has long been associated with preterm birth, for which there has been no physiological explanation. Recent studies have shown that RLN suppresses endotoxin-induced cytokine secretion from THP-1 monocytic cells by acting on the glucocorticoid receptor (GR), but its effects on primary macrophages are unknown. Therefore, in the present study, we examined the effects of RLN on cytokine secretion from primary decidual macrophages (DMs) obtained at term before labor. Unlike THP-1 cells, RLN had no effects on the cytokine responses induced by either lipopolysaccharide (LPS) or interleukin (IL) 1B, mimicking infection-induced or sterile inflammation, respectively. However, RLN alone for 4 h significantly decreased (P < 0.05) colony-stimulating factor 2 (CSF2; also known as granulocyte-macrophage colony-stimulating factor) and IL8 but for 24 h significantly increased IL6 (P < 0.01). We show that DMs express both the RLN receptor (RXFP1) and the GR. RLN suppression of CSF2 and IL8 was sensitive to the GR-antagonist mifepristone (RU-486). However, RLN activation of RXFP1 induced a dose-dependent cAMP response, which when mimicked by forskolin also caused significantly increased (P < 0.05) secretion of IL6. Thus, RLN may be anti-inflammatory in DMs via activation of the GR but proinflammatory via activation of RXFP1 and cAMP. In summary, we have shown that RLN targeting DMs may modulate proinflammatory cytokine secretion at the maternal-fetal interface and contribute to the localized inflammatory response associated with parturition in women.
Collapse
Affiliation(s)
- J S Horton
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii 96813, USA.
| | | | | |
Collapse
|
41
|
Abstract
Relaxin, a naturally-occurring hormone in the insulin family, was discovered to have a physiologic role in pregnancy. Named initially for its relaxing effect on the pubic ligament, relaxin receptors have since been found to be widely distributed in many organs in both males and females. Acting through multiple pathways, including the stimulation of gelatinases leading to activation of endothelin type B receptors and subsequently nitric oxide, relaxin has been shown to cause vasodilation. In animal models and studies in humans, relaxin has been shown to increase cardiac output and renal perfusion. Due to these effects, relaxin has been examined as a treatment for acute heart failure. The results of phase I and II trials have shown favorable clinical trends without any major adverse events, suggesting that relaxin has the potential to be an effective medication for acute heart failure in conjunction with or in place of current treatments.
Collapse
|
42
|
Ho TY, Santora K, Chen JC, Frankshun AL, Bagnell CA. Effects of relaxin and estrogens on bone remodeling markers, receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG), in rat adjuvant-induced arthritis. Bone 2011; 48:1346-53. [PMID: 21419242 DOI: 10.1016/j.bone.2011.03.684] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 03/07/2011] [Accepted: 03/09/2011] [Indexed: 12/20/2022]
Abstract
Rheumatoid arthritis (RA) is characterized by joint inflammation and bone destruction. The receptor activator of nuclear factor-kappa B ligand (RANKL)-osteoprotegerin (OPG) system is important for maintaining the balance between bone resorption and formation. Both serum RANKL/OPG protein and synovial tissue RANKL/OPG mRNA ratios are elevated in patients with RA. Studies indicate that hormones of pregnancy, estrogens and relaxin, administered in combination, reduce circulating (TNF)-α and joint inflammation in a rat adjuvant-induced arthritis (AIA) model of RA. The purpose of this study was to investigate whether relaxin (RLX), alone or in combination with estrogens, regulates the bone remodeling markers RANKL and OPG in vivo and in vitro. Results show that in AIA rats, treatment with relaxin, estradiol valerate (EV) or EV in combination with relaxin had no effect on circulating RANKL. However, EV increased systemic OPG and combined treatment with EV and relaxin further increased circulating OPG in comparison to EV alone. Importantly, the RANKL/OPG protein ratio was lower in rats treated with EV or EV+RLX when compared to arthritic controls. Relaxin in combination with EV decreased local RANKL transcripts, increased OPG mRNA and decreased the RANKL/OPG mRNA ratio in joints of arthritic rats when compared to controls. RLX family peptide receptor 1 (RXFP1) gene expression in joints of AIA rats increased in response to EV and EV+RLX. In parathyroid hormone-pretreated murine UMR 106-01 osteoblast cells, 17-β-estradiol (E) and E+RLX increased RXFP1 transcripts, while RLX reduced RANKL mRNA and protein expression. However, in vitamin D-treated primary rat osteoblast cells E+RLX increased OPG protein and reduced the RANKL/OPG protein ratio. These results suggest that modulation of the RANKL-OPG system by estrogens and RLX may contribute to their antiarthritic effects on bone during pregnancy.
Collapse
Affiliation(s)
- Teh-Yuan Ho
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | | | | | | | | |
Collapse
|
43
|
Brecht A, Bartsch C, Baumann G, Stangl K, Dschietzig T. Relaxin inhibits early steps in vascular inflammation. ACTA ACUST UNITED AC 2011; 166:76-82. [DOI: 10.1016/j.regpep.2010.09.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 08/22/2010] [Accepted: 09/13/2010] [Indexed: 12/14/2022]
|
44
|
Ivell R, Kotula-Balak M, Glynn D, Heng K, Anand-Ivell R. Relaxin family peptides in the male reproductive system--a critical appraisal. Mol Hum Reprod 2010; 17:71-84. [DOI: 10.1093/molehr/gaq086] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
|
45
|
Halls ML, Cooper DMF. Sub-picomolar relaxin signalling by a pre-assembled RXFP1, AKAP79, AC2, beta-arrestin 2, PDE4D3 complex. EMBO J 2010; 29:2772-87. [PMID: 20664520 PMCID: PMC2924647 DOI: 10.1038/emboj.2010.168] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 07/01/2010] [Indexed: 12/17/2022] Open
Abstract
Biochemical studies suggest that G-protein-coupled receptors (GPCRs) achieve exquisite signalling specificity by forming selective complexes, termed signalosomes. Here, using cAMP biosensors in single cells, we uncover a pre-assembled, constitutively active GPCR signalosome, that couples the relaxin receptor, relaxin family peptide receptor 1 (RXFP1), to cAMP following receptor stimulation with sub-picomolar concentrations of peptide. The physiological effects of relaxin, a pleiotropic hormone with therapeutic potential in cancer metastasis and heart failure, are generally attributed to local production of the peptide, that occur in response to sub-micromolar concentrations. The highly sensitive signalosome identified here provides a regulatory mechanism for the extremely low levels of relaxin that circulate. The signalosome includes requisite Galpha(s), Gbetagamma and adenylyl cyclase 2 (AC2); AC2 is functionally coupled to RXFP1 through AKAP79 binding to helix 8 of the receptor; activation of AC2 is tonically opposed by protein kinase A (PKA)-activated PDE4D3, scaffolded through a beta-arrestin 2 interaction with Ser(704) of the receptor C-terminus. This elaborate, pre-assembled, ligand-independent GPCR signalosome represents a new paradigm in GPCR signalling and provides a mechanism for the distal actions of low circulating levels of relaxin.
Collapse
Affiliation(s)
- Michelle L Halls
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | | |
Collapse
|
46
|
Abstract
Relaxin is a naturally occurring human peptide initially identified as a reproductive hormone. More recently, relaxin has been shown to play a key role in the maternal hemodynamic and renal adjustments that accommodate pregnancy. An understanding of these physiologic effects has led to the evaluation of relaxin as a pharmacologic agent for the treatment of patients with acute heart failure. Preliminary results have been encouraging. In addition, the other known biologic properties of relaxin, including anti-inflammatory effects, extracellular matrix remodeling effects, and angiogenic and anti-ischemic effects, all may play a role in potential benefits of relaxin therapy. Ongoing, large-scale clinical testing will provide additional insights into the potential role of relaxin in the treatment of heart failure.
Collapse
Affiliation(s)
- Sam L. Teichman
- Corthera, Inc, a subsidiary of Novartis Pharmaceuticals Corp., 1660 South Amphlett Boulevard, Suite 200, San Mateo, CA 94402 USA
| | - Elaine Unemori
- Corthera, Inc, a subsidiary of Novartis Pharmaceuticals Corp., 1660 South Amphlett Boulevard, Suite 200, San Mateo, CA 94402 USA
| | - John R. Teerlink
- Section of Cardiology, Veterans Affairs Medical Center, University of California, San Francisco VA Medical Center, Cardiology-111C, Building 203, Room 2A-49, 4150 Clement Street, San Francisco, CA 94121-1545 USA
| | - Gad Cotter
- Momentum Research, Inc, 3100 Tower Boulevard, Suite 802, Durham, NC 27707 USA
| | - Marco Metra
- Section of Cardiovascular Diseases, Department of Experimental and Applied Medicine, University of Brescia, Cardiology, University and Civil Hospital, Piazza Spedali Civili 1, 25123 Brescia, Italy
| |
Collapse
|
47
|
|
48
|
Dschietzig T, Bartsch C, Wessler S, Baumann G, Stangl K. Autoregulation of human relaxin-2 gene expression critically involves relaxin and glucocorticoid receptor binding to glucocorticoid response half-sites in the relaxin-2 promoter. ACTA ACUST UNITED AC 2009; 155:163-73. [DOI: 10.1016/j.regpep.2009.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/26/2009] [Accepted: 03/07/2009] [Indexed: 01/01/2023]
|
49
|
Summers RJ, Bathgate RAD, Wade JD, van der Westhuizen ET, Halls ML. Roles of the receptor, the ligand, and the cell in the signal transduction pathways utilized by the relaxin family peptide receptors 1-3. Ann N Y Acad Sci 2009; 1160:99-104. [PMID: 19416167 DOI: 10.1111/j.1749-6632.2009.03828.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The relaxin-like peptides produce their effects by acting at four G-protein-coupled receptors (GPCRs) RXFP1 to 4. RXFP1 and 2 are characterized by large extracellular domains containing leucine-rich repeats, whereas RXFP3 and 4 closely resemble small-peptide-liganded GPCRs. Studies with mutant RXFP1 receptors established that the final 10 amino acids of the C-terminus and Arg(752) in particular are obligatory for the second phase of cAMP signaling. Examination of the importance of cell type revealed different patterns of cAMP signaling related to the types of G-proteins expressed in these cells. Studies of RXFP3 signaling using reporter genes revealed that both relaxin and relaxin-3 activated the receptor but displayed different patterns of signaling. The studies suggest that the functional domains of the receptor, the cell type in which it is expressed, and the ligand used to activate the receptor all have important roles in determining the functional response observed.
Collapse
Affiliation(s)
- Roger J Summers
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Clayton, Victoria, Australia.
| | | | | | | | | |
Collapse
|
50
|
Samuel CS, Mookerjee I, Halls ML, Summers RJ, Chew E, Bathgate RAD, Tregear GW, Hewitson TD. Investigations into the Inhibitory Effects of Relaxin on Renal Myofibroblast Differentiation. Ann N Y Acad Sci 2009; 1160:294-9. [DOI: 10.1111/j.1749-6632.2008.03823.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|