1
|
Relaxin-2 as a Potential Biomarker in Cardiovascular Diseases. J Pers Med 2022; 12:jpm12071021. [PMID: 35887517 PMCID: PMC9317583 DOI: 10.3390/jpm12071021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 11/17/2022] Open
Abstract
The pleiotropic hormone relaxin-2 plays a pivotal role in the physiology and pathology of the cardiovascular system. Relaxin-2 exerts relevant regulatory functions in cardiovascular tissues through the specific receptor relaxin family peptide receptor 1 (RXFP1) in the regulation of cardiac metabolism; the induction of vasodilatation; the reversion of fibrosis and hypertrophy; the reduction of inflammation, oxidative stress, and apoptosis; and the stimulation of angiogenesis, with inotropic and chronotropic effects as well. Recent preclinical and clinical outcomes have encouraged the potential use of relaxin-2 (or its recombinant form, known as serelaxin) as a therapeutic strategy during cardiac injury and/or in patients suffering from different cardiovascular disarrangements, especially heart failure. Furthermore, relaxin-2 has been proposed as a promising biomarker of cardiovascular health and disease. In this review, we emphasize the relevance of the endogenous hormone relaxin-2 as a useful diagnostic biomarker in different backgrounds of cardiovascular pathology, such as heart failure, atrial fibrillation, myocardial infarction, ischemic heart disease, aortic valve disease, hypertension, and atherosclerosis, which could be relevant in daily clinical practice and could contribute to comprehending the specific role of relaxin-2 in cardiovascular diseases.
Collapse
|
2
|
Scurt FG, Morgenroth R, Bose K, Mertens PR, Chatzikyrkou C. Pr-AKI: Acute Kidney Injury in Pregnancy – Etiology, Diagnostic Workup, Management. Geburtshilfe Frauenheilkd 2022; 82:297-316. [PMID: 35250379 PMCID: PMC8893985 DOI: 10.1055/a-1666-0483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 10/09/2021] [Indexed: 10/29/2022] Open
Abstract
AbstractDespite significant improvements in inpatient and outpatient management, pregnancy-related acute kidney injury (Pr-AKI) remains an important risk factor for early and late maternal and
fetal morbidity and mortality. There is a discrepancy between the incidence of Pr-AKI in developing and in developed countries, with the former experiencing a decrease and the latter an
increase in Pr-AKI in recent decades. Whereas septic and hemorrhagic complications predominated in the past, nowadays hypertensive disorders and thrombotic microangiopathy are the leading
causes of Pr-AKI. Modern lifestyles and the availability and widespread use of in-vitro fertilization techniques in industrialized countries have allowed more women of advanced age to become
pregnant. This has led to a rise in the percentage of high-risk pregnancies due to the disorders and comorbidities inherent to or accompanying aging, such as diabetes, arterial hypertension
and preexisting chronic kidney disease. Last but not least, the heterogeneity of symptoms, the often overlapping clinical and laboratory characteristics and the pathophysiological changes
related to pregnancy make the diagnosis and management of Pr-AKI a difficult and challenging task for the treating physician. In addition to general supportive management strategies such as
volume substitution, blood pressure control, prevention of seizures or immediate delivery, each disease entity requires a specific therapy to reduce maternal and fetal complications. In this
review, we used the current literature to provide a summary of the physiologic and pathophysiologic changes in renal physiology which occur during pregnancy. In the second part, we present
common and rare disorders which lead to Pr-AKI and provide an overview of the available treatment options.
Collapse
Affiliation(s)
- Florian G. Scurt
- Klinik für Nieren- und Hochdruckerkrankungen, Diabetologie und Endokrinologie, Medizinische Fakultät der Otto-von-Guericke-Universität, Magdeburg, Germany
| | - Ronnie Morgenroth
- Klinik für Nieren- und Hochdruckerkrankungen, Diabetologie und Endokrinologie, Medizinische Fakultät der Otto-von-Guericke-Universität, Magdeburg, Germany
| | - Katrin Bose
- Universitätsklinik für Gastroenterologie, Hepatologie und Infektiologie, Medizinische Fakultät der Otto-von-Guericke-Universität, Magdeburg, Germany
| | - Peter R. Mertens
- Klinik für Nieren- und Hochdruckerkrankungen, Diabetologie und Endokrinologie, Medizinische Fakultät der Otto-von-Guericke-Universität, Magdeburg, Germany
| | - Christos Chatzikyrkou
- PHV-Dialysezentrum, Halberstadt, Germany
- Klinik für Nephrologie, Medizinische Hochschule Hannover, Hannover, Germany
| |
Collapse
|
3
|
Fournier SB, D'Errico JN, Stapleton PA. Uterine Vascular Control Preconception and During Pregnancy. Compr Physiol 2021; 11:1871-1893. [PMID: 34061977 DOI: 10.1002/cphy.c190015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Successful pregnancy and reproduction are dependent on adequate uterine blood flow, placental perfusion, and vascular responsivity to fetal demands. The ability to support pregnancy centers on systemic adaptation and endometrial preparation through decidualization, embryonic implantation, trophoblast invasion, arterial/arteriolar reactivity, and vascular remodeling. These adaptations occur through responsiveness to endocrine signaling and local uteroplacental mediators. The purpose of this article is to highlight the current knowledge associated with vascular remodeling and responsivity during uterine preparation for and during pregnancy. We focus on maternal cardiovascular systemic and uterine modifications, endometrial decidualization, implantation and invasion, uterine and spiral artery remodeling, local uterine regulatory mechanisms, placentation, and pathological consequences of vascular dysfunction during pregnancy. © 2021 American Physiological Society. Compr Physiol 11:1-23, 2021.
Collapse
Affiliation(s)
- Sara B Fournier
- Environmental and Occupational Health Sciences Institute, Piscataway, New Jersey, USA
| | - Jeanine N D'Errico
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, USA
| | - Phoebe A Stapleton
- Environmental and Occupational Health Sciences Institute, Piscataway, New Jersey, USA.,Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, USA
| |
Collapse
|
4
|
Beers K, Patel N. Kidney Physiology in Pregnancy. Adv Chronic Kidney Dis 2020; 27:449-454. [PMID: 33328060 DOI: 10.1053/j.ackd.2020.07.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 11/11/2022]
Abstract
A woman's body undergoes a myriad of changes throughout the course of a normal gestation. The kidneys play a central role in driving adjustments that guarantee maternal and fetal well-being, including a dramatic increase in glomerular filtration rate, alterations in tubular function, and changes in electrolyte and acid/base handling. Early in gestation, systemic vasodilation, driven by both a change in quantity of and response to various hormones, leads to increased renal blood flow and glomerular filtration rate. Vasodilation also results in activation of the renin-angiotensin-aldosterone axis, which combined with changing tubular handling causes alterations in total body stores of electrolytes and total body water, resulting in a lower serum sodium concentration. In addition, mild proteinuria, glucosuria, and a decrease in serum calcium and magnesium are common. The primary acid/base change seen in pregnancy is a mild respiratory alkalosis due to progesterone effects. This article provides an overview of the current understanding of the healthy response of the kidneys to pregnancy, an understanding of which is key to caring for the pregnant patient, and early identification of alterations that may indicate underlying kidney pathology in pregnancy.
Collapse
|
5
|
Abstract
Maternal cardiovascular changes during pregnancy include an expansion of plasma volume, increased cardiac output, decreased peripheral resistance, and increased uteroplacental blood flow. These adaptations facilitate the progressive increase in uteroplacental perfusion that is required for normal fetal growth and development, prevent the development of hypertension, and provide a reserve of blood in anticipation of the significant blood loss associated with parturition. Each woman's genotype and phenotype determine her ability to adapt in response to molecular signals that emanate from the fetoplacental unit. Here, we provide an overview of the major hemodynamic and cardiac changes and then consider regional changes in the splanchnic, renal, cerebral, and uterine circulations in terms of endothelial and vascular smooth muscle cell plasticity. Although consideration of gestational disease is beyond the scope of this review, aberrant signaling and/or maternal responsiveness contribute to the etiology of several common gestational diseases such as preeclampsia, intrauterine growth restriction, and gestational diabetes.
Collapse
Affiliation(s)
- George Osol
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont 05405, USA;
| | - Nga Ling Ko
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont 05405, USA;
| | - Maurizio Mandalà
- Department of Biology, Ecology and Earth Science, University of Calabria, 87036 Arcavacata di Rende (CS), Italy
| |
Collapse
|
6
|
Nascimento RA, Possomato-Vieira JS, Bonacio GF, Rizzi E, Dias-Junior CA. Reductions of Circulating Nitric Oxide are Followed by Hypertension during Pregnancy and Increased Activity of Matrix Metalloproteinases-2 and -9 in Rats. Cells 2019; 8:cells8111402. [PMID: 31703340 PMCID: PMC6912623 DOI: 10.3390/cells8111402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/03/2019] [Indexed: 12/14/2022] Open
Abstract
Hypertensive pregnancy has been associated with reduced nitric oxide (NO), bioavailability, and increased activity of matrix metalloproteinases (MMPs). However, it is unclear if MMPs activation is regulated by NO during pregnancy. To this end, we examined activity of MMP-2 and MMP-9 in plasma, placenta, uterus and aorta, NO bioavailability, oxidative stress, systolic blood pressure (SBP), and fetal-placental development at the early, middle, and late pregnancy stages in normotensive and Nω-Nitro-L-arginine methyl-ester (L-NAME)-induced hypertensive pregnancy in rats. Reduced MMP-2 activity in uterus, placenta, and aorta and reduced MMP-9 activity in plasma and placenta with concomitant increased NO levels were found in normotensive pregnant rats. By contrast, increased MMP-2 activity in uterus, placenta, and aorta, and increased MMP-9 activity in plasma and placenta with concomitant reduced NO levels were observed in hypertensive pregnant rats. Also, elevated oxidative stress was displayed by hypertensive pregnant rats at the middle and late stages. These findings in the L-NAME-treated pregnant rats were also followed by increases in SBP and associated with fetal growth restrictions at the middle and late pregnancy stages. We concluded that NO bioavailability may regulate MMPs activation during normal and hypertensive pregnancy.
Collapse
Affiliation(s)
- Regina A. Nascimento
- Department of Pharmacology, Biosciences Institute of Botucatu, Sao Paulo State University – UNESP, Botucatu, Sao Paulo 18.618-689, Brazil; (R.A.N.); (J.S.P.-V.)
| | - Jose S. Possomato-Vieira
- Department of Pharmacology, Biosciences Institute of Botucatu, Sao Paulo State University – UNESP, Botucatu, Sao Paulo 18.618-689, Brazil; (R.A.N.); (J.S.P.-V.)
| | - Giselle F. Bonacio
- Unit of Biotechnology, University of Ribeirao Preto, UNAERP, Ribeirao Preto, Sao Paulo 14096-900, Brazil; (G.F.B.); (E.R.)
| | - Elen Rizzi
- Unit of Biotechnology, University of Ribeirao Preto, UNAERP, Ribeirao Preto, Sao Paulo 14096-900, Brazil; (G.F.B.); (E.R.)
| | - Carlos A. Dias-Junior
- Department of Pharmacology, Biosciences Institute of Botucatu, Sao Paulo State University – UNESP, Botucatu, Sao Paulo 18.618-689, Brazil; (R.A.N.); (J.S.P.-V.)
- Correspondence: ; Tel.: +55 14 3880-0214
| |
Collapse
|
7
|
Abstract
Hypertensive disorders of pregnancy are common and contribute inordinately to maternal and fetal morbidity and mortality. Although not completely understood, recent clinical trials have provided important insights into pathogenesis of preeclampsia. Preeclampsia is considered a systemic disease with generalized endothelial dysfunction and risk of future cardiovascular disease. This review revisits the definitions and classifications of hypertensive disorders of pregnancy; discusses updates on pathophysiology, prevention, and early prediction of preeclampsia; reviews current management guidelines; and discusses potential risks and benefits associated with treatment. Improvement in management and outcomes of women with hypertensive disorders of pregnancy seems in sight in the near future.
Collapse
Affiliation(s)
- Silvi Shah
- Division of Nephrology, Kidney CARE Program, University of Cincinnati, 231 Albert Sabin Way, MSB 6211, Cincinnati, OH 45267, USA.
| | - Anu Gupta
- Buffalo Medical Group, 2121 Main Street #305, Buffalo, NY 14214, USA
| |
Collapse
|
8
|
Marshall SA, Cox AG, Parry LJ, Wallace EM. Targeting the vascular dysfunction: Potential treatments for preeclampsia. Microcirculation 2018; 26:e12522. [PMID: 30556222 DOI: 10.1111/micc.12522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/22/2018] [Accepted: 12/10/2018] [Indexed: 12/18/2022]
Abstract
Preeclampsia is a pregnancy-specific disorder, primarily characterized by new-onset hypertension in combination with a variety of other maternal or fetal signs. The pathophysiological mechanisms underlying the disease are still not entirely clear. Systemic maternal vascular dysfunction underlies the clinical features of preeclampsia. It is a result of oxidative stress and the actions of excessive anti-angiogenic factors, such as soluble fms-like tyrosine kinase, soluble endoglin, and activin A, released by a dysfunctional placenta. The vascular dysfunction then leads to impaired regulation and secretion of relaxation factors and an increase in sensitivity/production of constrictors. This results in a more constricted vasculature rather than the relaxed vasodilated state associated with normal pregnancy. Currently, the only effective "treatment" for preeclampsia is delivery of the placenta and therefore the baby. Often, this means a preterm delivery to save the life of the mother, with all the attendant risks and burdens associated with fetal prematurity. To lessen this burden, there is a pressing need for more effective treatments that target the maternal vascular dysfunction that underlies the hypertension. This review details the vascular effects of key drugs undergoing clinical assessment as potential treatments for women with preeclampsia.
Collapse
Affiliation(s)
- Sarah A Marshall
- Departments of Obstetrics and Gynaecology and Medicine, School of Clinical Sciences, The Ritchie Centre, Monash University, Clayton, Victoria, Australia
| | - Annie G Cox
- Departments of Obstetrics and Gynaecology and Medicine, School of Clinical Sciences, The Ritchie Centre, Monash University, Clayton, Victoria, Australia
| | - Laura J Parry
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Euan M Wallace
- Departments of Obstetrics and Gynaecology and Medicine, School of Clinical Sciences, The Ritchie Centre, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
9
|
Schiffner R, Nistor M, Bischoff SJ, Matziolis G, Schmidt M, Lehmann T. Effects of human relaxin-2 (serelaxin) on hypoxic pulmonary vasoconstriction during acute hypoxia in a sheep model. HYPOXIA (AUCKLAND, N.Z.) 2018; 6:11-22. [PMID: 29862306 PMCID: PMC5968803 DOI: 10.2147/hp.s165092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Purpose Hypoxia induces pulmonary vasoconstriction with a subsequent increase of pulmonary artery pressure (PAP), which can result in pulmonary hypertension. Serelaxin has shown an increase of pulmonary hemodynamic parameters after serelaxin injection. We therefore investigated the response of pulmonary hemodynamic parameters after serelaxin administration in a clinically relevant model. Methods Six controls and six sheep that received 30 μg/kg serelaxin underwent right heart catheterization during a 12-minute hypoxia period (inhalation of 5% oxygen and 95% nitrogen) and subsequent reoxygenation. Systolic, diastolic, and mean values of both PAP (respectively, PAPs, PAPd, and PAPm) and pulmonary capillary wedge pressure (respectively, PCWPs, PCWPd, and PCWPm), blood gases, heart rate (HR), and both peripheral and pulmonary arterial oxygen saturation were obtained. Cardiac output (CO), stroke volume (SV), pulmonary vascular resistance (PVR), pulmonary arterial compliance (PAcompl), and systemic vascular resistance (SVR) were calculated. Results The key findings of the current study are that serelaxin prevents the rise of PAPs (p≤0.001), PAPm, PCWPm, PCWPs (p≤0.03), and PAPd (p≤0.05) during hypoxia, while it simultaneously increases CO and SV (p≤0.001). Similar courses of decreases of PAPm, PAPd, PAPs, CO, SVR (p≤0.001), and PCWPd (p≤0.03) as compared to hypoxic values were observed during reoxygenation. In direct comparison, the experimental groups differed during hypoxia in regard to HR, PAPm, PVR, and SVR (p≤0.03), and during reoxygenation in regard to HR (p≤0.001), PAPm, PAPs, PAPd, PVR, SVR (p≤0.03), and PCWPd (p≤0.05). Conclusion The findings of this study suggest that serelaxin treatment improves pulmonary hemodynamic parameters during acute hypoxia.
Collapse
Affiliation(s)
| | | | | | | | | | - Thomas Lehmann
- Institute of Medical Statistics, Computer Sciences and Documentation Science, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| |
Collapse
|
10
|
|
11
|
Marshall SA, O'Sullivan K, Ng H, Bathgate RA, Parry LJ, Hossain MA, Leo CH. B7-33 replicates the vasoprotective functions of human relaxin-2 (serelaxin). Eur J Pharmacol 2017; 807:190-197. [DOI: 10.1016/j.ejphar.2017.05.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/28/2017] [Accepted: 05/02/2017] [Indexed: 01/21/2023]
|
12
|
Schiffner R, Reiche J, Schmidt M, Jung C, Walther S, Irintchev A, Bischoff SJ. Pulmonary arterial compliance and pulmonary hemodynamic effects of Serelaxin in a sheep model. Clin Hemorheol Microcirc 2017; 66:219-229. [DOI: 10.3233/ch-170269] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- René Schiffner
- Department of Orthopaedic, Jena University Hospital, Friedrich Schiller University, Jena, Germany
- Department of Neurology, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Juliane Reiche
- Institute for Biochemistry II, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Martin Schmidt
- Institute for Biochemistry II, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Christian Jung
- Division of Cardiology, Pulmonology and Vascular Medicine, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Sebastian Walther
- Department of Orthopaedic, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Andrey Irintchev
- Department of Otorhinolaryngology, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Sabine J. Bischoff
- Institute for Laboratory Animal Science and Welfare, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| |
Collapse
|
13
|
ML290 is a biased allosteric agonist at the relaxin receptor RXFP1. Sci Rep 2017; 7:2968. [PMID: 28592882 PMCID: PMC5462828 DOI: 10.1038/s41598-017-02916-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/20/2017] [Indexed: 01/02/2023] Open
Abstract
Activation of the relaxin receptor RXFP1 has been associated with improved survival in acute heart failure. ML290 is a small molecule RXFP1 agonist with simple structure, long half-life and high stability. Here we demonstrate that ML290 is a biased agonist in human cells expressing RXFP1 with long-term beneficial actions on markers of fibrosis in human cardiac fibroblasts (HCFs). ML290 did not directly compete with orthosteric relaxin binding and did not affect binding kinetics, but did increase binding to RXFP1. In HEK-RXFP1 cells, ML290 stimulated cAMP accumulation and p38MAPK phosphorylation but not cGMP accumulation or ERK1/2 phosphorylation although prior addition of ML290 increased p-ERK1/2 responses to relaxin. In human primary vascular endothelial and smooth muscle cells that endogenously express RXFP1, ML290 increased both cAMP and cGMP accumulation but not p-ERK1/2. In HCFs, ML290 increased cGMP accumulation but did not affect p-ERK1/2 and given chronically activated MMP-2 expression and inhibited TGF-β1-induced Smad2 and Smad3 phosphorylation. In vascular cells, ML290 was 10x more potent for cGMP accumulation and p-p38MAPK than for cAMP accumulation. ML290 caused strong coupling of RXFP1 to Gαs and GαoB but weak coupling to Gαi3. ML290 exhibited signalling bias at RXFP1 possessing a signalling profile indicative of vasodilator and anti-fibrotic properties.
Collapse
|
14
|
Samuel CS, Royce SG, Hewitson TD, Denton KM, Cooney TE, Bennett RG. Anti-fibrotic actions of relaxin. Br J Pharmacol 2017; 174:962-976. [PMID: 27250825 PMCID: PMC5406285 DOI: 10.1111/bph.13529] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 12/19/2022] Open
Abstract
Fibrosis refers to the hardening or scarring of tissues that usually results from aberrant wound healing in response to organ injury, and its manifestations in various organs have collectively been estimated to contribute to around 45-50% of deaths in the Western world. Despite this, there is currently no effective cure for the tissue structural and functional damage induced by fibrosis-related disorders. Relaxin meets several criteria of an effective anti-fibrotic based on its specific ability to inhibit pro-fibrotic cytokine and/or growth factor-mediated, but not normal/unstimulated, fibroblast proliferation, differentiation and matrix production. Furthermore, relaxin augments matrix degradation through its ability to up-regulate the release and activation of various matrix-degrading matrix metalloproteinases and/or being able to down-regulate tissue inhibitor of metalloproteinase activity. Relaxin can also indirectly suppress fibrosis through its other well-known (anti-inflammatory, antioxidant, anti-hypertrophic, anti-apoptotic, angiogenic, wound healing and vasodilator) properties. This review will outline the organ-specific and general anti-fibrotic significance of exogenously administered relaxin and its mechanisms of action that have been documented in various non-reproductive organs such as the cardiovascular system, kidney, lung, liver, skin and tendons. In addition, it will outline the influence of sex on relaxin's anti-fibrotic actions, highlighting its potential as an emerging anti-fibrotic therapeutic. 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)
- C S Samuel
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of PharmacologyMonash UniversityMelbourneVic.Australia
| | - S G Royce
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of PharmacologyMonash UniversityMelbourneVic.Australia
| | - T D Hewitson
- Department of NephrologyRoyal Melbourne HospitalMelbourneVic.Australia
| | - K M Denton
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of PhysiologyMonash UniversityMelbourneVic.Australia
| | - T E Cooney
- University of Pittsburgh Medical Centre (UPMC) HamotEriePAUSA
| | - R G Bennett
- Research Service 151VA Nebraska‐Western Iowa Health Care SystemOmahaNEUSA
- Department of Internal MedicineUniversity of Nebraska Medical CenterOmahaNEUSA
| |
Collapse
|
15
|
Leo CH, Fernando DT, Tran L, Ng HH, Marshall SA, Parry LJ. Serelaxin Treatment Reduces Oxidative Stress and Increases Aldehyde Dehydrogenase-2 to Attenuate Nitrate Tolerance. Front Pharmacol 2017; 8:141. [PMID: 28377719 PMCID: PMC5359255 DOI: 10.3389/fphar.2017.00141] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/07/2017] [Indexed: 02/01/2023] Open
Abstract
Background: Glyceryl trinitrate (GTN) is a commonly prescribed treatment for acute heart failure patients. However, prolonged GTN treatment induces tolerance, largely due to increased oxidative stress and reduced aldehyde dehydrogenase-2 (ALDH-2) expression. Serelaxin has several vasoprotective properties, which include reducing oxidative stress and augmenting endothelial function. We therefore tested the hypothesis in rodents that serelaxin treatment could attenuate low-dose GTN-induced tolerance. Methods and Results: Co-incubation of mouse aortic rings ex vivo with GTN (10 μM) and serelaxin (10 nM) for 1 h, restored GTN responses, suggesting that serelaxin prevented the development of GTN tolerance. Male Wistar rats were subcutaneously infused with ethanol (control), low-dose GTN+placebo or low-dose GTN+serelaxin via osmotic minipumps for 3 days. Aortic vascular function and superoxide levels were assessed using wire myography and lucigenin-enhanced chemiluminescence assay respectively. Changes in aortic ALDH-2 expression were measured by qPCR and Western blot respectively. GTN+placebo infusion significantly increased superoxide levels, decreased ALDH-2 and attenuated GTN-mediated vascular relaxation. Serelaxin co-treatment with GTN significantly enhanced GTN-mediated vascular relaxation, reduced superoxide levels and increased ALDH-2 expression compared to GTN+placebo-treated rats. Conclusion: Our data demonstrate that a combination of serelaxin treatment with low dose GTN attenuates the development of GTN-induced tolerance by reducing superoxide production and increasing ALDH-2 expression in the rat aorta. We suggest that serelaxin may improve nitrate efficacy in a clinical setting.
Collapse
Affiliation(s)
- Chen Huei Leo
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | | | - Lillie Tran
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | - Hooi Hooi Ng
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | - Sarah A Marshall
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | - Laura J Parry
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| |
Collapse
|
16
|
Unemori E. Serelaxin in clinical development: past, present and future. Br J Pharmacol 2017; 174:921-932. [PMID: 28009437 DOI: 10.1111/bph.13695] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/18/2016] [Accepted: 12/05/2016] [Indexed: 12/15/2022] Open
Abstract
The availability of highly purified recombinant human relaxin, serelaxin, has allowed clinical trials to be conducted in several indications and the elucidation of its pharmacology in human subjects. These studies have demonstrated that serelaxin has unique haemodynamic properties that are likely to contribute to organ protection and long-term outcome benefits in acute heart failure. Clinical observations support its consideration for therapeutic use in other patient populations, including those with chronic heart failure, coronary artery disease, portal hypertension and acute renal failure. 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
|
17
|
Leo CH, Jelinic M, Ng HH, Marshall SA, Novak J, Tare M, Conrad KP, Parry LJ. Vascular actions of relaxin: nitric oxide and beyond. Br J Pharmacol 2016; 174:1002-1014. [PMID: 27590257 DOI: 10.1111/bph.13614] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/24/2016] [Accepted: 08/29/2016] [Indexed: 12/28/2022] Open
Abstract
The peptide hormone relaxin regulates the essential maternal haemodynamic adaptations in early pregnancy through direct actions on the renal and systemic vasculature. These vascular actions of relaxin occur mainly through endothelium-derived NO-mediated vasodilator pathways and improvements in arterial compliance in small resistance-size arteries. This work catalysed a plethora of studies which revealed quite heterogeneous responses across the different regions of the vasculature, and also uncovered NO-independent mechanisms of relaxin action. In this review, we first describe the role of endogenous relaxin in maintaining normal vascular function, largely referring to work in pregnant and male relaxin-deficient animals. We then discuss the diversity of mechanisms mediating relaxin action in different vascular beds, including the involvement of prostanoids, VEGF, endothelium-derived hyperpolarisation and antioxidant activity in addition to the classic NO-mediated vasodilatory pathway. We conclude the review with current perspectives on the vascular remodelling capabilities of relaxin. 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)
- C H Leo
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - M Jelinic
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - H H Ng
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - S A Marshall
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - J Novak
- Division of Mathematics and Science, Walsh University, North Canton, OH, USA
| | - M Tare
- Department of Physiology, Monash University, Clayton, VIC, Australia.,School of Rural Health, Monash University, Clayton, VIC, Australia
| | - K P Conrad
- Department of Physiology and Functional Genomics, Department of Obstetrics and Gynaecology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - L J Parry
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
18
|
Abstract
Glomerular filtration rate (GFR) and renal plasma flow (RPF) increase by 40-65% and 50-85%, respectively, during normal pregnancy in women. Studies using the gravid rat as a model have greatly enhanced our understanding of mechanisms underlying these remarkable changes in the renal circulation during gestation. Hyperfiltration appears to be almost completely due to the increase in RPF, the latter attributable to profound reductions in both the renal afferent and efferent arteriolar resistances. The major pregnancy hormone involved is relaxin. The mediators downstream from relaxin include endothelin (ET) and nitric oxide (NO). New evidence indicates that relaxin increases vascular gelatinase activity during pregnancy, thereby converting big ET to ET(1-32), which leads to renal vasodilation, hyperfiltration, and reduced myogenic reactivity of small renal arteries via the endothelial ET(B) receptor and NO. Whether the chronic volume expansion characteristic of pregnancy contributes to the maintenance of gestational renal changes requires further investigation. Additional studies are also needed to further delineate the molecular basis of these mechanisms and, importantly, to investigate whether they apply to women.
Collapse
Affiliation(s)
- Kirk P Conrad
- Departments of Obstetrics, Gynecology and Reproductive Sciences, and Cell Biology and Physiology, University of Pittsburgh School of Medicine and Magee-Women's Research Institute, Pittsburgh, Pennsylvania 15213, USA.
| |
Collapse
|
19
|
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
|
20
|
Conrad KP. G-Protein-coupled receptors as potential drug candidates in preeclampsia: targeting the relaxin/insulin-like family peptide receptor 1 for treatment and prevention. Hum Reprod Update 2016; 22:647-64. [PMID: 27385360 DOI: 10.1093/humupd/dmw021] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/16/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Important roles for G-protein-coupled receptors (GPCRs) have been identified in the maternal physiological adaptations to pregnancy and in the pathogenesis of preeclampsia. On this basis, GPCRs are potential therapeutic targets for preeclampsia. OBJECTIVES AND RATIONALE In this review, vasopressin and apelin are initially considered in this context before the focus on the hormone relaxin and its cognate receptor, the relaxin/insulin-like family peptide receptor 1 (RXFP1). Based on both compelling scientific rationale and a promising safety profile, the relaxin ligand-receptor system is comprehensively evaluated as a potential therapeutic endpoint in preeclampsia. SEARCH METHODS The published literature relating to the topic was searched through January 2016 using PubMed. OUTCOMES Relaxin is a peptide hormone secreted by the corpus luteum; it circulates in the luteal phase and during pregnancy. Activation of RXFP1 is vasodilatory; thus, relaxin supplementation is expected to at least partly restore the fundamental vasodilatory changes of normal pregnancy, thereby alleviating maternal organ hypoperfusion, which is a major pathogenic manifestation of severe preeclampsia. Specifically, by exploiting its pleiotropic hemodynamic attributes in preeclampsia, relaxin administration is predicted to (i) reverse robust arterial myogenic constriction; (ii) blunt systemic and renal vasoconstriction in response to activation of the angiotensin II receptor, type 1; (iii) mollify the action of endogenous vasoconstrictors on uterine spiral arteries with failed remodeling and retained smooth muscle; (iv) increase arterial compliance; (v) enhance insulin-mediated glucose disposal by promoting skeletal muscle vasodilation and (vi) mobilize and activate bone marrow-derived angiogenic progenitor cells, thereby repairing injured endothelium and improving maternal vascularity in organs such as breast, uterus, pancreas, skin and fat. By exploiting its pleiotropic molecular attributes in preeclampsia, relaxin supplementation is expected to (i) enhance endothelial nitric oxide synthesis and bioactivity, as well as directly reduce vascular smooth muscle cytosolic calcium, thus promoting vasodilation; (ii) improve the local angiogenic balance by augmenting arterial vascular endothelial and placental growth factor (VEGF and PLGF) activities; (iii) ameliorate vascular inflammation; (iv) enhance placental peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PCG1α) expression, and hence, peroxisome proliferator-activated receptor gamma (PPAR-γ) activity and (v) confer cytotrophoblast and endothelial cytoprotection. Insofar as impaired endometrial maturation (decidualization) predisposes to the development of preeclampsia, relaxin administration in the late secretory phase and during early pregnancy would be anticipated to improve decidualization, and hence trophoblast invasion and spiral artery remodeling, thereby reducing the risk of preeclampsia. Relaxin has a favorable safety profile both in the non-pregnant condition and during pregnancy. WIDER IMPLICATIONS There is a strong scientific rationale for RXFP1 activation in severe preeclampsia by administration of relaxin, relaxin analogs or small molecule mimetics, in order to mollify the disease pathogenesis for safe prolongation of pregnancy, thus allowing time for more complete fetal maturation, which is a primary therapeutic endpoint in treating the disease. In light of recent data implicating deficient or defective decidualization as a potential etiological factor in preeclampsia and the capacity of relaxin to promote endometrial maturation, the prophylactic application of relaxin to reduce the risk of preeclampsia is a plausible therapeutic approach to consider. Finally, given its pleiotropic and beneficial attributes particularly in the cardiovascular system, relaxin, although traditionally considered as a 'pregnancy' hormone, is likely to prove salutary for several disease indications in the non-pregnant population.
Collapse
Affiliation(s)
- Kirk P Conrad
- Department of Physiology and Functional Genomics and Department of Obstetrics and Gynecology, D.H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, 1600 SW Archer Road, PO Box 100274 M522, Gainesville, FL 32610, USA
| |
Collapse
|
21
|
|
22
|
Endothelin-1: Biosynthesis, Signaling and Vasoreactivity. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 77:143-75. [PMID: 27451097 DOI: 10.1016/bs.apha.2016.05.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Endothelin-1 (ET-1) is an extremely potent vasoconstrictor peptide originally isolated from endothelial cells. Its synthesis, mainly regulated at the gene transcription level, involves processing of a precursor by a furin-type proprotein convertase to an inactive intermediate, big ET-1. The latter peptide can then be cleaved directly by an endothelin-converting enzyme (ECE) into ET-1 or reach the active metabolite through a two-step process involving chymase hydrolyzing big ET-1 to ET-1 (1-31), itself needing conversion to ET-1 by neprilysin (NEP) to exert physiological activity. ET-1 signals through two G protein-coupled receptors, endothelin receptor A (ETA) and endothelin receptor B (ETB). Both receptors induce an increase in intracellular Ca(2+), mainly from the extracellular space through voltage-independent mechanisms, the receptor-operated channels and store-operated channels. ET-1 also induces signaling through epidermal growth factor receptor transactivation, oxidative stress induction, rho-kinase, and the activation (ETA) or inhibition (ETB) of the adenylate cyclase/cyclic adenosine monophosphate pathway. Arterial vasoconstriction is mediated mainly by the ETA receptor. ET-1, via endothelium-located ETB, relaxes arteries or constricts vessels following activation of the same receptor type on the smooth muscle, where it can interact with ETA. In addition, ETB-dependent vasoconstriction seems more prominent in the venous vasculature. A better understanding of how ET-1 is synthesized and how ETA and ETB receptors interact could help design better pharmacological agents in the treatment of cardiovascular diseases where targeting the ET-1 system is indicated.
Collapse
|
23
|
Serelaxin: A Novel Therapeutic for Vascular Diseases. Trends Pharmacol Sci 2016; 37:498-507. [PMID: 27130518 DOI: 10.1016/j.tips.2016.04.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/31/2016] [Accepted: 04/04/2016] [Indexed: 12/19/2022]
Abstract
Vascular dysfunction is an important hallmark of cardiovascular disease. It is characterized by increased sensitivity to vasoconstrictors, decreases in the endothelium-derived vasodilators nitric oxide (NO) and prostacyclin (PGI2), and endothelium-derived hyperpolarization (EDH). Serelaxin (recombinant human relaxin) has gained considerable attention as a new vasoactive drug, largely through its beneficial therapeutic effects in acute heart failure. In this review we first describe the contribution of endogenous relaxin to vascular homeostasis. We then provide a comprehensive overview of the novel mechanisms of serelaxin action in blood vessels that differentiate it from other vasodilator drugs and explain how this peptide could be used more widely as a therapeutic to alleviate vascular dysfunction in several cardiovascular diseases.
Collapse
|
24
|
Gillis EE, Sasser JM, Sullivan JC. Endothelin, sex, and pregnancy: unique considerations for blood pressure control in females. Am J Physiol Regul Integr Comp Physiol 2016; 310:R691-6. [PMID: 26936781 DOI: 10.1152/ajpregu.00427.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/24/2016] [Indexed: 12/31/2022]
Abstract
Endothelin-1 (ET-1) is a potent vasoconstrictor, and dysregulation of the endothelin (ET) system has been implicated in the development of hypertension. Sex differences in the ET system have been identified in ET receptor expression and activation, levels of ET-1, and downstream mediators of the ET system. More specifically, males have greater ET-1/ETA receptor activation, whereas females exhibit greater ETB receptor activation. These differences have been suggested to contribute to the sex differences observed in blood pressure control, with greater ETB receptor activation in females potentially acting as an important pathway contributing to the lower prevalence of hypertension in young females compared with age-matched males. This hypothesis is further supported by studies in pregnancy; the role of the ET system is enhanced during pregnancy, with dysregulation of the ET system resulting in preeclampsia. Further research is necessary to elucidate the relative roles of the ET system in blood pressure control in both sexes and to further explore the potential benefits of pharmacological ET blockade in women.
Collapse
Affiliation(s)
- Ellen E Gillis
- Department of Physiology, Georgia Regents University, Augusta, Georgia; and
| | - Jennifer M Sasser
- Department of Pharmacology, University of Mississippi Medical Center, Jackson, Mississippi
| | | |
Collapse
|
25
|
Leo CH, Jelinic M, Ng HH, Tare M, Parry LJ. Time-dependent activation of prostacyclin and nitric oxide pathways during continuous i.v. infusion of serelaxin (recombinant human H2 relaxin). Br J Pharmacol 2016; 173:1005-17. [PMID: 26660642 DOI: 10.1111/bph.13404] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 12/02/2015] [Accepted: 12/04/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE In the RELAX-AHF trial, a 48 h i.v. serelaxin infusion reduced systemic vascular resistance in patients with acute heart failure. Consistent with preclinical studies, serelaxin augments endothelial vasodilator function in rat mesenteric arteries. Little is known about the contribution of endothelium-derived relaxing factors after a longer duration of continuous serelaxin treatment. Here we have assessed vascular reactivity and mechanistic pathways in mesenteric arteries and veins and the aorta after 48 or 72 h continuous i.v. infusion of serelaxin. EXPERIMENTAL APPROACH Male rats were infused with either placebo or serelaxin (13.3 μg·kg(-1) ·h(-1) ) via the jugular vein using osmotic minipumps. Vascular function was assessed using wire myography. Changes in gene and protein expression and 6-keto PGF1α levels were determined by quantitative PCR, Western blot and ELISA respectively. KEY RESULTS Continuous i.v. serelaxin infusion augmented endothelium-dependent relaxation in arteries (mesenteric and aorta) but not in mesenteric veins. In mesenteric arteries, 48 h i.v. serelaxin infusion increased basal NOS activity, associated with increased endothelial NOS (eNOS) expression. Interestingly, phosphorylated-eNOS(Ser1177) , eNOS and basal NOS activity were reduced in mesenteric arteries following 72 h serelaxin treatment. At 72 h, serelaxin treatment improved bradykinin-mediated relaxation through COX2-derived PGI2 production. CONCLUSIONS AND IMPLICATIONS Continuous i.v. serelaxin infusion enhanced endothelial vasodilator function in arteries but not in veins. The underlying mediator at 48 h was NO but there was a transition to PGI2 by 72 h. Activation of the PGI2 -dependent pathway is key to the prolonged vascular response to serelaxin treatment.
Collapse
Affiliation(s)
- C H Leo
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - M Jelinic
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - H H Ng
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - M Tare
- Department of Physiology and School of Rural Health, Monash University, Parkville, Vic, Australia
| | - L J Parry
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| |
Collapse
|
26
|
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
|
27
|
Sarwar M, Samuel CS, Bathgate RA, Stewart DR, Summers RJ. Enhanced serelaxin signalling in co-cultures of human primary endothelial and smooth muscle cells. Br J Pharmacol 2016; 173:484-96. [PMID: 26493539 DOI: 10.1111/bph.13371] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 10/06/2015] [Accepted: 10/10/2015] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND AND PURPOSE In the phase III clinical trial, RELAX-AHF, serelaxin caused rapid and long-lasting haemodynamic changes. However, the cellular mechanisms involved are unclear in humans. EXPERIMENTAL APPROACH This study examined the effects of serelaxin in co-cultures of human primary endothelial cells (ECs) and smooth muscle cells (SMCs) on cAMP and cGMP signalling. KEY RESULTS Stimulation of HUVECs or human coronary artery endothelial cells (HCAECs) with serelaxin, concentration-dependently increased cGMP accumulation in co-cultured SMCs to a greater extent than in monocultures of either cell type. This was not observed in human umbilical artery endothelial cells (HUAECs) that do not express the relaxin receptor, RXFP1. Treatment of ECs with l-N(G) -nitro arginine (NOARG; 30 μM, 30 min) inhibited serelaxin-mediated (30 nM) cGMP accumulation in HUVECs, HCAECs and co-cultured SMCs. In HCAECs, but not HUVECs, pre-incubation with indomethacin (30 μM, 30 min) also inhibited cGMP accumulation in SMCs. Pre-incubation of SMCs with the guanylate cyclase inhibitor ODQ (1 μM, 30 min) had no effect on serelaxin-mediated (30 nM) cGMP accumulation in HUVECs and HCAECs but inhibited cGMP accumulation in SMCs. Serelaxin stimulation of HCAECs, but not HUVECs, increased cAMP accumulation concentration-dependently in SMCs. Pre-incubation of HCAECs with indomethacin, but not l-NOARG, abolished cAMP accumulation in co-cultured SMCs, suggesting involvement of prostanoids. CONCLUSIONS AND IMPLICATIONS In co-cultures, treatment of ECs with serelaxin caused marked cGMP accumulation in SMCs and with HCAEC also cAMP accumulation. Responses involved EC-derived NO and with HCAEC prostanoid production. Thus, serelaxin differentially modulates vascular tone in different vascular beds.
Collapse
Affiliation(s)
- M Sarwar
- Drug Discovery Biology, Monash Institute of Pharmacology, Monash University, Australia
| | - C S Samuel
- Department of Pharmacology, Monash University, Australia
| | - R A Bathgate
- The Florey Institute of Neuroscience and Mental Health and the Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
| | | | - R J Summers
- Drug Discovery Biology, Monash Institute of Pharmacology, Monash University, Australia
| |
Collapse
|
28
|
Abstract
With the total cases and economic burden of heart failure continuing to rise, there is an overwhelming need for novel therapies. Several drugs for heart failure have succeeded in preclinical and early-phase clinical trials, but most of them failed to show the real benefit in pivotal clinical trials. Meanwhile, the US Food and Drug Administration recently approved two promising new drugs to treat heart failure: ivabradine and sacubitril/valsartan. Furthermore, some of the newer agents in testing offer the potential for significant progress in addition to these drugs. Patiromer and zirconium cyclosilicate are attractive agents that are expected to prevent hyperkalemia during renin-angiotensin-aldosterone system inhibition, and serelaxin and urodilatin are promising drugs in the treatment of acute heart failure. Future clinical trials with more appropriate study designs, optimal clinical endpoints, and proper patient selection are mandatory to assess the true efficacy of these attractive compounds in clinical practice.
Collapse
Affiliation(s)
- Takeshi Kitai
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Wh Wilson Tang
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Clinical Genomics, Cleveland Clinic, Cleveland, OH, USA
| |
Collapse
|
29
|
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
|
30
|
Fernandez-Patron C, Leung D. Emergence of a metalloproteinase / phospholipase A2 axis of systemic inflammation. ACTA ACUST UNITED AC 2015; 2:29-38. [PMID: 26491703 DOI: 10.2147/mnm.s48748] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We review select aspects of the biology of matrix metalloproteinases (MMPs) with a focus on the modulation of inflammatory responses by MMP-2. MMP-2 is a zinc- and calcium-dependent endoprotease with substrates including extracellular matrix proteins, vasoactive peptides and chemokines. Humans and mice with MMP-2 deficiency exhibit a predominantly inflammatory phenotype. Recent research shows that MMP-2 deficient mice display elevated activity of a secreted phospholipase A2 in the heart. Additionally, MMP-2 deficient mice exhibit abnormally high prostaglandin E2 levels in various organs (i.e., the heart, brain and liver), signs of inflammation and exacerbated lipopolysaccharide-induced fever. We briefly review the biology of sPLA2 enzymes to propose the existence of a heart-centric MMP-2/sPLA2 axis of systemic inflammation. Moreover, we postulate that PLA2 activation is induced by chemokines, whose ability to signal inflammation is regulated in a tissue-specific fashion by MMPs. Thus, genetic and pharmacologically induced MMP-deficiencies can be expected to perturb PLA2-mediated inflammatory mechanisms.
Collapse
Affiliation(s)
- Carlos Fernandez-Patron
- Department of Biochemistry, Cardiovascular Research Group and Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Dickson Leung
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
31
|
Ng HH, Jelinic M, Parry LJ, Leo CH. Increased superoxide production and altered nitric oxide-mediated relaxation in the aorta of young but not old male relaxin-deficient mice. Am J Physiol Heart Circ Physiol 2015; 309:H285-96. [DOI: 10.1152/ajpheart.00786.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 05/06/2015] [Indexed: 11/22/2022]
Abstract
The vascular effects of exogenous relaxin (Rln) treatment are well established and include decreased myogenic reactivity and enhanced relaxation responses to vasodilators in small resistance arteries. These vascular responses are reduced in older animals, suggesting that Rln is less effective in mediating arterial function with aging. The present study investigated the role of endogenous Rln in the aorta and the possibility that vascular dysfunction occurs more rapidly with aging in Rln-deficient ( Rln−/−) mice. We compared vascular function and underlying vasodilatory pathways in the aorta of male wild-type ( Rln+/+) and Rln−/− mice at 4 and 16 mo of age using wire myography. Superoxide production, but not nitrotyrosine or NADPH oxidase expression, was significantly increased in the aorta of young Rln−/− mice, whereas endothelial nitric oxide (NO) synthase and basal NO availability were both significantly decreased compared with Rln+/+ mice. In the presence of the cyclooxygenase inhibitor indomethacin, sensitivity to ACh was significantly decreased in young Rln−/− mice, demonstrating altered NO-mediated relaxation that was normalized in the presence of a membrane-permeable SOD or ROS scavenger. These vascular phenotypes were not exacerbated in old Rln−/− mice and, in most cases, did not differ significantly from old Rln+/+ mice. Despite the vascular phenotypes in Rln−/− mice, endothelium-dependent and -independent vasodilation were not adversely affected. Our data show a role for endogenous Rln in reducing superoxide production and maintaining NO availability in the aorta but also demonstrate that Rln deficiency does not compromise vascular function in this artery or exacerbate endothelial dysfunction associated with aging.
Collapse
Affiliation(s)
- Hooi H. Ng
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Maria Jelinic
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Laura J. Parry
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Chen-Huei Leo
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
32
|
Sarwar M, Samuel CS, Bathgate RA, Stewart DR, Summers RJ. Serelaxin-mediated signal transduction in human vascular cells: bell-shaped concentration-response curves reflect differential coupling to G proteins. Br J Pharmacol 2014; 172:1005-19. [PMID: 25297987 DOI: 10.1111/bph.12964] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 09/16/2014] [Accepted: 09/24/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE In a recently conducted phase III clinical trial, RELAX-AHF, serelaxin infusion over 48 h improved short- and long-term clinical outcomes in patients with acute heart failure. In this study we used human primary cells from the umbilical vasculature to better understand the signalling mechanisms activated by serelaxin. EXPERIMENTAL APPROACH We examined the acute effects of serelaxin on signal transduction mechanisms in primary human umbilical vascular cells and its chronic actions on markers of cardiovascular function and disease. KEY RESULTS The RXFP1 receptor, the cognate serelaxin receptor, was expressed at the cell surface in HUVECs and human umbilical vein smooth muscle cells (HUVSMCs), human umbilical artery smooth muscle cells (HUASMCs) and human cardiac fibroblasts (HCFs), but not human umbilical artery endothelial cells. In HUVECs and HUVSMCs, serelaxin increased cAMP, cGMP accumulation and pERK1/2, and the concentration-response curves (CRCs) were bell-shaped. Similar bell-shaped CRCs for cGMP and pERK1/2 were observed in HCFs, whereas in HUASMCs, serelaxin increased cAMP, cGMP and pERK1/2 with sigmoidal CRCs. Gαi/o and lipid raft disruption, but not Gαs inhibition, altered the serelaxin CRC for cAMP and cGMP accumulation in HUVSMC but not HUASMC. Longer term serelaxin exposure increased the expression of neuronal NOS, VEGF, ETβ receptors and MMPs (gelatinases) in RXFP1 receptor-expressing cells. CONCLUSIONS AND IMPLICATIONS Serelaxin caused acute and chronic changes in human umbilical vascular cells that were cell background dependent. Bell-shaped CRCs that were observed only in venous cells and fibroblasts involved Gαi/o located within membrane lipid rafts.
Collapse
Affiliation(s)
- M Sarwar
- Drug Discovery Biology, Monash Institute of Pharmacology, Monash University, Melbourne, Vic., Australia
| | | | | | | | | |
Collapse
|
33
|
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
|
34
|
Duarte C, Kobayashi Y, Kawamoto T, Moriyama K. RELAXIN enhances differentiation and matrix mineralization through Relaxin/insulin-like family peptide receptor 2 (Rxfp2) in MC3T3-E1 cells in vitro. Bone 2014; 65:92-101. [PMID: 24857857 DOI: 10.1016/j.bone.2014.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 04/18/2014] [Accepted: 05/05/2014] [Indexed: 01/19/2023]
Abstract
RELAXIN (RLN) is a polypeptide hormone of the insulin-like hormone family; it facilitates birth by softening and widening the pubic symphysis and cervix in many mammals, including humans. The role of RLN in bone metabolism was recently suggested by its ability to induce osteoclastogenesis and activate osteoclast function. RLN binds to RELAXIN/INSULIN-LIKE FAMILY PEPTIDE 1 (RXFP1) and 2 (RXFP2), with varying species-specific affinities. Young men with mutated RXFP2 are at high risk for osteoporosis, as RXFP2 influences osteoblast metabolism by binding to INSULIN-LIKE PEPTIDE 3 (INSL3). However, there have been no reports on RLN function in osteoblast differentiation and mineralization or on the functionally dominant receptors for RLN in osteoblasts. We previously described Rxfp1 and 2 expression patterns in developing mouse oral components, including the maxillary and mandibular bones, Meckel's cartilage, tongue, and tooth primordia. We hypothesized that Rln/Rxfp signaling is a key mediator of skeletal development and metabolism. Here, we present the gene expression patterns of Rxfp1 and 2 in developing mouse calvarial frontal bones as determined by in situ hybridization. In addition, RLN enhanced osteoblastic differentiation and caused abnormal mineralization and extracellular matrix metabolism through Rxfp2, which was predominant over Rxfp1 in MC3T3-E1 mouse calvarial osteoblasts. Our data suggest a novel role for Rln in craniofacial skeletal development and metabolism through Rxfp2.
Collapse
Affiliation(s)
- Carolina Duarte
- Maxillofacial Orthognathics, Department of Maxillofacial Reconstruction and Function, Division of Maxillofacial/Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Yukiho Kobayashi
- Maxillofacial Orthognathics, Department of Maxillofacial Reconstruction and Function, Division of Maxillofacial/Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Hard Tissue Genome Research Center, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510 Japan.
| | - Tatsuo Kawamoto
- Maxillofacial Orthognathics, Department of Maxillofacial Reconstruction and Function, Division of Maxillofacial/Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Keiji Moriyama
- Maxillofacial Orthognathics, Department of Maxillofacial Reconstruction and Function, Division of Maxillofacial/Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Hard Tissue Genome Research Center, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510 Japan.
| |
Collapse
|
35
|
Abstract
PURPOSE OF REVIEW Renal dysfunction during pregnancy is a common and serious complication. Understanding normal physiology during pregnancy provides a context to further describe changes in pregnancy that lead to renal dysfunction and may provide clues to better management. RECENT FINDINGS Hormonal changes during pregnancy allow for increased blood flow to the kidneys and altered autoregulation such that glomerular filtration rate (GFR) increases significantly through reductions in net glomerular oncotic pressure and increased renal size. The mechanisms for maintenance of increased GFR change through the trimesters of pregnancy, continuing into the postpartum period. Important causes of pregnancy-specific renal dysfunction have been further studied, but much needs to be learned. Pre-eclampsia is due to abnormal placentation, with shifts in angiogenic proteins and the renin-angiotensin-aldosterone system leading to endothelial injury and clinical manifestations of hypertension and organ dysfunction. Other thrombotic microangiopathies occurring during pregnancy have been better defined as well, with new work focusing on the contribution of the complement system to these disorders. SUMMARY Advances have been made in understanding the physiology of the kidney in normal pregnancy. Diseases that affect the kidney during pregnancy alter this physiology in various ways that inform clinicians on pathogenesis and may lead to improved therapeutic approaches and better outcomes of pregnancy.
Collapse
|
36
|
Paradis A, Zhang L. Role of endothelin in uteroplacental circulation and fetal vascular function. Curr Vasc Pharmacol 2014; 11:594-605. [PMID: 24063378 DOI: 10.2174/1570161111311050004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/10/2012] [Accepted: 07/12/2012] [Indexed: 01/01/2023]
Abstract
Endothelins are 21-amino acid peptides involved in vascular homeostasis. Three types of peptide have been identified, with endothelin-1 (ET-1) being the most potent vasoconstrictor currently known. Two endothelin receptor subtypes are found in various tissues, including the brain, heart, blood vessel, lung, and placenta. The ETA-receptor is associated with vasoconstriction in vascular smooth muscle. Conversely, the ETB-receptor can elicit a vasoconstrictor effect in vascular smooth muscle and a vasodilator effect via its action in endothelial cells. Both receptors play a key role in maintaining circulatory homeostasis and vascular function. Changes in ET-1 expression are found in various disease states, and overexpression of ET-1 is observed in hypertension and preeclampsia in pregnancy. Placental localization of ET-1 implies a key role in regulating the uteroplacental circulation. Additionally, ET-1 is important in the fetal circulation and is involved in the pulmonary circulation and closure of the ductus arteriosus after birth, as well as fetal growth constriction in utero. ET receptor antagonists and nitric oxide donors may provide therapeutic potential in treating conditions associated with overexpression of ET and hypertension.
Collapse
Affiliation(s)
- Alexandra Paradis
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA.
| | | |
Collapse
|
37
|
Tkachenko O, Shchekochikhin D, Schrier RW. Hormones and hemodynamics in pregnancy. Int J Endocrinol Metab 2014; 12:e14098. [PMID: 24803942 PMCID: PMC4005978 DOI: 10.5812/ijem.14098] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 10/15/2013] [Accepted: 12/10/2013] [Indexed: 11/16/2022] Open
Abstract
CONTEXT Normal pregnancy is associated with sodium and water retention, which results in plasma volume expansion prior to placental implantation. The explanation offered for these events is that pregnancy 'resets' both volume and osmoreceptors. EVIDENCE ACQUISITION The mechanisms for such an enigmatic 'resetting' in pregnancy have not previously been explained. However, recent human pregnancy studies have demonstrated that the earliest hemodynamic change in pregnancy is primary systemic arterial vasodilation. This arterial underfilling is associated with a secondary increase in cardiac output and activation of the neurohumoral axis, including stimulation of the renin-angiotensin-aldosterone, sympathetic, and non-osmotic vasopressin systems. Resistance to the pressor effects of angiotensin and sympathetic stimulation in pregnancy is compatible with an increase in endothelial nitric oxide synthase activity. RESULTS In contrast to the sodium and water retention which occur secondary to the primary arterial vasodilation in cirrhosis, glomerular filtration and renal blood flow are significantly increased in normal pregnancy. A possible explanation for this difference in arterial vasodilation states is that relaxin, an arterial vasodilator which increases during pregnancy, has a potent effect on both systemic and renal circulation. Endothelial damage in pregnancy is pivotal in the pathogenesis of preeclampsia in pregnancy. CONCLUSIONS Against a background of the primary arterial vasodilation hypothesis, it is obvious that reversal of the systemic vasodilatation in pregnancy, without subsequent activation of the renin-angiotensin-aldosterone system (78), will evoke a reversal of all the links in the chain of events in normal pregnancy adaptation, thus, it may cause preeclampsia. Namely, a decrease of renal vasodilation will decrease glomerular filtration rate.
Collapse
Affiliation(s)
- Oleksandra Tkachenko
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Denver, Colorado, USA
| | - Dmitry Shchekochikhin
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Denver, Colorado, USA
| | - Robert W. Schrier
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Denver, Colorado, USA
- Corresponding author: Robert W. Schrier, Department of Medicine, University of Colorado, 12700 East 19th Avenue C281, Aurora, CO 80045, USA. Tel: +1-3037244837, Fax: +1-3037244868, E-mail:
| |
Collapse
|
38
|
Conrad KP, Davison JM. The renal circulation in normal pregnancy and preeclampsia: is there a place for relaxin? Am J Physiol Renal Physiol 2014; 306:F1121-35. [PMID: 24647709 DOI: 10.1152/ajprenal.00042.2014] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
During the first trimester of human pregnancy, the maternal systemic circulation undergoes remarkable vasodilation. The kidneys participate in this vasodilatory response resulting in marked increases in renal plasma flow (RPF) and glomerular filtration rate (GFR). Comparable circulatory adaptations are observed in conscious gravid rats. Administration of the corpus luteal hormone relaxin (RLN) to nonpregnant rats and humans elicits vasodilatory changes like those of pregnancy. Systemic and renal vasodilation are compromised in midterm pregnant rats by neutralization or elimination of circulating RLN and in women conceiving with donor eggs who lack a corpus luteum and circulating RLN. Although RLN exerts both rapid (minutes) and sustained (hours to days) vasodilatory actions through different molecular mechanisms, a final common pathway is endothelial nitric oxide. In preeclampsia (PE), maternal systemic and renal vasoconstriction leads to hypertension and modest reduction in GFR exceeding that of RPF. Elevated level of circulating soluble vascular endothelial growth factor receptor-1 arising from the placenta is implicated in the hypertension and disruption of glomerular fenestrae and barrier function, the former causing reduced Kf and the latter proteinuria. Additional pathogenic factors are discussed. Last, potential clinical ramifications include RLN replacement in women conceiving with donor eggs and its therapeutic use in PE. Another goal has been to apply knowledge gained from investigating circulatory adaptations in pregnancy toward identifying and developing novel therapeutic strategies for renal and cardiovascular disease in the nonpregnant population. So far, one candidate to emerge is RLN and its potential therapeutic use in heart failure.
Collapse
Affiliation(s)
- Kirk P Conrad
- Departments of Physiology and Functional Genomics and Obstetrics and Gynecology, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida College of Medicine, Gainesville, Florida; and
| | - John M Davison
- Institute of Cellular Medicine and Royal Victoria Infirmary, Newcastle University and Newcastle Hospitals National Health Service Foundation Trust, Newcastle Upon Tyne, United Kingdom
| |
Collapse
|
39
|
Leo CH, Jelinic M, Parkington HC, Tare M, Parry LJ. Acute intravenous injection of serelaxin (recombinant human relaxin-2) causes rapid and sustained bradykinin-mediated vasorelaxation. J Am Heart Assoc 2014; 3:e000493. [PMID: 24584737 PMCID: PMC3959707 DOI: 10.1161/jaha.113.000493] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background A recent clinical trial (RELAXin in Acute Heart Failure [RELAX‐AHF]) demonstrated that 48 hours of continuous intravenous infusion of the vasorelaxant peptide serelaxin (recombinant human relaxin‐2) to patients with acute heart failure reduced cardiovascular mortality at 180 days. The persistence of a vasorelaxant response as a potential mechanism for this long‐term benefit and the vascular effects of a bolus intravenous injection of serelaxin have not been examined. This study investigates changes in resistance artery reactivity and passive mechanical wall properties following an intravenous serelaxin injection and whether these vascular effects persist in the absence of detectable circulating serelaxin. Methods and Results Male rats were injected with 13.3 μg/kg serelaxin into the tail vein; mesenteric arteries were assessed 3 and 24 hours after treatment by using wire‐myography. Serelaxin increased basal nitric oxide synthase activity and reduced maximal contraction to endothelin‐1 at 3 hours after administration. Serelaxin treatment also selectively enhanced bradykinin‐mediated endothelium‐dependent relaxation. This effect was sustained for 24 hours in the absence of circulating serelaxin. Serelaxin‐mediated augmentation of bradykinin‐evoked relaxation involved endothelium‐derived hyperpolarization after 3 hours and prostacyclin‐mediated relaxation after 24 hours. Furthermore, upregulation of inducible nitric oxide synthase, phosphorylation of protein kinase B at Ser473 and endothelial nitric oxide synthase at Ser1177 was observed at 24 hours after serelaxin injection. There were no effects of serelaxin on passive arterial wall stiffness. Conclusion Our data show that a bolus intravenous injection of serelaxin modulates endothelial vasodilator function 3 hours after administration, an effect that was sustained for 24 hours. The prolonged bradykinin‐mediated vasorelaxation is principally mediated through prostacyclin.
Collapse
Affiliation(s)
- Chen Huei Leo
- Department of Zoology, The University of Melbourne, Parkville, VIC, Australia
| | | | | | | | | |
Collapse
|
40
|
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
|
41
|
Sasser JM. The emerging role of relaxin as a novel therapeutic pathway in the treatment of chronic kidney disease. Am J Physiol Regul Integr Comp Physiol 2013; 305:R559-65. [PMID: 23883673 DOI: 10.1152/ajpregu.00528.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Emerging evidence supports a potential therapeutic role of relaxin in fibrotic diseases, including chronic kidney disease. Relaxin is a pleiotropic hormone, best characterized for its role in the reproductive system; however, recent studies have demonstrated a role of relaxin in the cardiorenal system. Both relaxin and its receptor, RXFP1, are expressed in the kidney, and relaxin has been shown to play a role in renal vasodilation, in sodium excretion, and as an antifibrotic agent. Together, these findings suggest that the kidney is a target organ of relaxin. Therefore, the purpose of this review is to describe the functional and structural impacts of relaxin treatment on the kidney and to discuss evidence that relaxin prevents disease progression in several experimental models of kidney disease. In addition, this review will present potential mechanisms that are involved in the therapeutic actions of relaxin.
Collapse
Affiliation(s)
- Jennifer M Sasser
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| |
Collapse
|
42
|
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
|
43
|
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
|
44
|
Wang X, Bosonea AM, Fernandez-Patron C. Metalloproteinases: key and common mediators of multiple GPCRs and candidate therapeutic targets in models of hypertensive cardiac disease. ACTA ACUST UNITED AC 2012; 9:e103-e108. [PMID: 24976848 DOI: 10.1016/j.ddmod.2012.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hypertensive cardiac disease remains a major cause of death worldwide because its typically complex etiology renders current treatments ineffective. Primary causative factors include environmental stressors, genetic predisposition and metabolic morbidities such as obesity and diabetes. These factors all trigger a systemic pathological production of agonists of G-protein-coupled receptors (GPCRs). When produced in excess, GPCR agonists transactivate many metalloproteinases, which relay agonist signaling. Here we review evidence supporting a global therapeutic concept for treatment of hypertensive cardiac disease with complex or unknown etiology by targeting common mediators of multiple GPCRs such as metalloproteinases and their downstream effectors.
Collapse
Affiliation(s)
- Xiang Wang
- Department of Biochemistry, School of Translational Medicine and the Cardiovascular Research Group, University of Alberta, Edmonton, AB, Canada
| | - Ana-Maria Bosonea
- Department of Biochemistry, School of Translational Medicine and the Cardiovascular Research Group, University of Alberta, Edmonton, AB, Canada
| | - Carlos Fernandez-Patron
- Department of Biochemistry, School of Translational Medicine and the Cardiovascular Research Group, University of Alberta, Edmonton, AB, Canada ; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
45
|
Odutayo A, Hladunewich M. Obstetric Nephrology: Renal Hemodynamic and Metabolic Physiology in Normal Pregnancy. Clin J Am Soc Nephrol 2012; 7:2073-80. [DOI: 10.2215/cjn.00470112] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
46
|
Abstract
Preeclampsia is an important obstetric complication that arises in 5% of women after the 20(th) week of gestation, for which there is no specific therapy and no cure. Although much of the recent investigation in this field has focused on soluble forms of the angiogenic membrane receptor tyrosine kinase Flt1 and the transforming growth factor β co-receptor Endoglin, there is significant clinical potential for several GPCR targets and their agonists or antagonists in preeclampsia. In this review, we discuss several of the most promising candidates in this category, including calcitonin receptor-like receptor / receptor activity modifying protein 1 complexes, the angiotensin AT1, 2 and Mas receptors, and the relaxin receptor RXFP1. We also address some of the controversies surrounding the roles and therapeutic potential of these GPCRs and their (ant)agonists in preeclampsia.
Collapse
Affiliation(s)
- Jt McGuane
- D.H. Barron Reproductive and Perinatal Biology Outcomes Research Program, and Department of Physiology and Functional Genomics, and of Obstetrics and Gynecology, University of Florida College of Medicine, Gainesville, FL 32610
| | | |
Collapse
|
47
|
Yu WH, Huang PT, Lou KL, Yu SSC, Lin C. A smallest 6 kda metalloprotease, mini-matrilysin, in living world: a revolutionary conserved zinc-dependent proteolytic domain- helix-loop-helix catalytic zinc binding domain (ZBD). J Biomed Sci 2012; 19:54. [PMID: 22642296 PMCID: PMC3406945 DOI: 10.1186/1423-0127-19-54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 05/29/2012] [Indexed: 12/12/2022] Open
Abstract
Background The Aim of this study is to study the minimum zinc dependent metalloprotease catalytic folding motif, helix B Met loop-helix C, with proteolytic catalytic activities in metzincin super family. The metzincin super family share a catalytic domain consisting of a twisted five-stranded β sheet and three long α helices (A, B and C). The catalytic zinc is at the bottom of the cleft and is ligated by three His residues in the consensus sequence motif, HEXXHXXGXXH, which is located in helix B and part of the adjacent Met turn region. An interesting question is - what is the minimum portion of the enzyme that still possesses catalytic and inhibitor recognition?” Methods We have expressed a 60-residue truncated form of matrilysin which retains only the helix B-Met turn-helix C region and deletes helix A and the five-stranded β sheet which form the upper portion of the active cleft. This is only 1/4 of the full catalytic domain. The E. coli derived 6 kDa MMP-7 ZBD fragments were purified and refolded. The proteolytic activities were analyzed by Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 peptide assay and CM-transferrin zymography analysis. SC44463, BB94 and Phosphoramidon were computationally docked into the 3day structure of the human MMP7 ZBD and TAD and thermolysin using the docking program GOLD. Results This minimal 6 kDa matrilysin has been refolded and shown to have proteolytic activity in the Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 peptide assay. Triton X-100 and heparin are important factors in the refolding environment for this mini-enzyme matrilysin. This minienzyme has the proteolytic activity towards peptide substrate, but the hexamer and octamer of the mini MMP-7 complex demonstrates the CM-transferrin proteolytic activities in zymographic analysis. Peptide digestion is inhibited by SC44463, specific MMP7 inhibitors, but not phosphorimadon. Interestingly, the mini MMP-7 can be processed by autolysis and producing ~ 6 ~ 7 kDa fragments. Thus, many of the functions of the enzyme are retained indicating that the helix B-Met loop-helix C is the minimal functional “domain” found to date for the matrixin family. Conclusions The helix B-Met loop-helix C folding conserved in metalloprotease metzincin super family is able to facilitate proteolytic catalysis for specific substrate and inhibitor recognition. The autolysis processing and producing 6 kDa mini MMP-7 is the smallest metalloprotease in living world.
Collapse
Affiliation(s)
- Wei-Hsuan Yu
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | | | | | | | | |
Collapse
|
48
|
Abstract
Administering relaxin to conscious rats and humans elicits systemic and renal vasodilation. The molecular mechanisms vary according to the duration of relaxin exposure-so-called "rapid" (within minutes) or "sustained" (hours to days) vasodilatory responses-both being endothelium-dependent. Rapid responses are mediated by G(αi/o) protein coupling to phosphoinositol-3 kinase/Akt (protein kinase B)-dependent phosphorylation and activation of nitric oxide synthase. Sustained responses are mediated by vascular endothelial and placental growth factors, as well as increases in arterial gelatinase activity. Thus, after hours or days of relaxin treatment, respectively, arterial MMP-9 or MMP-2 hydrolyze "big" endothelin (ET) at a gly-leu bond to form ET(1-32), which in turn activates the endothelial ET(B) receptor/nitric oxide vasodilatory pathway. Administration of relaxin to conscious rats also increases global systemic arterial compliance and passive compliance of select isolated blood vessels such as small renal arteries (SRA). The increase in SRA passive compliance is mediated by both geometric remodeling (outward) and compositional remodeling (decreased collagen). Relaxin-induced geometric remodeling has also been observed in brain parenchymal arteries, and this remodeling appears to be via the activation of peroxisome proliferator-activated receptor-γ. Given the vasodilatory and arterial remodeling properties of relaxin, the hormone may have therapeutic potential in the settings of abnormal pregnancies, heart failure, and pathologies associated with stiffening of arteries.
Collapse
|
49
|
Abstract
Preeclampsia is one of the leading causes of maternal morbidity/mortality. The pathogenesis of preeclampsia is still under investigation. The aim of this paper is to present the molecular mechanisms implicating in the pathway leading to preeclampsia.
Collapse
|
50
|
McGuane JT, Debrah JE, Sautina L, Jarajapu YPR, Novak J, Rubin JP, Grant MB, Segal M, Conrad KP. Relaxin induces rapid dilation of rodent small renal and human subcutaneous arteries via PI3 kinase and nitric oxide. Endocrinology 2011; 152:2786-96. [PMID: 21558316 PMCID: PMC3115605 DOI: 10.1210/en.2010-1126] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The peptide hormone relaxin is a potent vasodilator with therapeutic potential in diseases complicated by vasoconstriction, including heart failure. However, the molecular mediators and magnitude of vasodilation may vary according to duration of exposure and artery type. The objective of these studies was to determine mechanisms of rapid (within minutes) relaxin-induced vasodilation and to examine whether relaxin dilates arteries from different animal species and vascular beds. Rat and mouse small renal, rat mesenteric, and human sc arteries were isolated, mounted in a pressure arteriograph, and treated with recombinant human relaxin (rhRLX; 1-100 ng/ml) after preconstriction with phenylephrine. Rat and mouse small renal as well as human sc arteries dilated in response to rhRLX, whereas rat mesenteric arteries did not. Endothelial removal or pretreatment with l-N(G)-monomethyl arginine (L-NMMA) abolished rapid relaxin-induced vasodilation; phosphatidylinositol-3-kinase (PI3K) inhibitors also prevented it. In cultured human endothelial cells, rhRLX stimulated nitric oxide (assessed using 4-amino-5-methylamino-2'7'-difluorofluorescein) as well as Akt and endothelial NO synthase (eNOS) phosphorylation by Western blotting but not increases in intracellular calcium (evaluated by fura-2). NO production was attenuated by inhibition of Gα(i/o) and Akt (using pertussis toxin and the allosteric inhibitor MK-2206, respectively), PI3K, and NOS. Finally, the dilatory effect of rhRLX in rat small renal arteries was unexpectedly potentiated, rather than inhibited, by pretreatment with the vascular endothelial growth factor receptor inhibitor SU5416. We conclude that relaxin rapidly dilates select arteries across a range of species. The mechanism appears to involve endothelial Gα(i/o) protein coupling to PI3K, Akt, and eNOS but not vascular endothelial growth factor receptor transactivation or increased calcium.
Collapse
MESH Headings
- Adult
- Angiogenesis Inhibitors/pharmacology
- Animals
- Cells, Cultured
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiology
- Enzyme Inhibitors/pharmacology
- Female
- Humans
- In Vitro Techniques
- Kidney/blood supply
- Male
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/metabolism
- Mice
- Mice, Inbred C57BL
- Middle Aged
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nitric Oxide/metabolism
- Organ Specificity
- Phosphatidylinositol 3-Kinase/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Rats
- Rats, Long-Evans
- Recombinant Proteins/metabolism
- Relaxin/physiology
- Signal Transduction/drug effects
- Species Specificity
- Subcutaneous Tissue/blood supply
- Vasodilation/drug effects
Collapse
Affiliation(s)
- Jonathan T McGuane
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida 32610, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|