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Endothelin and the Cardiovascular System: The Long Journey and Where We Are Going. BIOLOGY 2022; 11:biology11050759. [PMID: 35625487 PMCID: PMC9138590 DOI: 10.3390/biology11050759] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 12/12/2022]
Abstract
Simple Summary In this review, we describe the basic functions of endothelin and related molecules, including their receptors and enzymes. Furthermore, we discuss the important role of endothelin in several cardiovascular diseases, the relevant clinical evidence for targeting the endothelin pathway, and the scope of endothelin-targeting treatments in the future. We highlight the present uses of endothelin receptor antagonists and the advancements in the development of future treatment options, thereby providing an overview of endothelin research over the years and its future scope. Abstract Endothelin was first discovered more than 30 years ago as a potent vasoconstrictor. In subsequent years, three isoforms, two canonical receptors, and two converting enzymes were identified, and their basic functions were elucidated by numerous preclinical and clinical studies. Over the years, the endothelin system has been found to be critical in the pathogenesis of several cardiovascular diseases, including hypertension, pulmonary arterial hypertension, heart failure, and coronary artery disease. In this review, we summarize the current knowledge on endothelin and its role in cardiovascular diseases. Furthermore, we discuss how endothelin-targeting therapies, such as endothelin receptor antagonists, have been employed to treat cardiovascular diseases with varying degrees of success. Lastly, we provide a glimpse of what could be in store for endothelin-targeting treatment options for cardiovascular diseases in the future.
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Mullins LJ, Conway BR, Menzies RI, Denby L, Mullins JJ. Renal disease pathophysiology and treatment: contributions from the rat. Dis Model Mech 2017; 9:1419-1433. [PMID: 27935823 PMCID: PMC5200898 DOI: 10.1242/dmm.027276] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The rat has classically been the species of choice for pharmacological studies and disease modeling, providing a source of high-quality physiological data on cardiovascular and renal pathophysiology over many decades. Recent developments in genome engineering now allow us to capitalize on the wealth of knowledge acquired over the last century. Here, we review rat models of hypertension, diabetic nephropathy, and acute and chronic kidney disease. These models have made important contributions to our understanding of renal diseases and have revealed key genes, such as Ace and P2rx7, involved in renal pathogenic processes. By targeting these genes of interest, researchers are gaining a better understanding of the etiology of renal pathologies, with the promised potential of slowing disease progression or even reversing the damage caused. Some, but not all, of these target genes have proved to be of clinical relevance. However, it is now possible to generate more sophisticated and appropriate disease models in the rat, which can recapitulate key aspects of human renal pathology. These advances will ultimately be used to identify new treatments and therapeutic targets of much greater clinical relevance. Summary: This Review highlights the key role that the rat continues to play in improving our understanding of the etiologies of renal pathologies, and how these insights have opened up new therapeutic avenues.
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Affiliation(s)
- Linda J Mullins
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Bryan R Conway
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Robert I Menzies
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Laura Denby
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - John J Mullins
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
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Lu YP, Hasan AA, Zeng S, Hocher B. Plasma ET-1 Concentrations Are Elevated in Pregnant Women with Hypertension -Meta-Analysis of Clinical Studies. Kidney Blood Press Res 2017; 42:654-663. [PMID: 29212079 DOI: 10.1159/000482004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 09/04/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The ET system might be involved in the pathogenesis of hypertensive disorders during pregnancy. The objective is to analyse the impact of ET-1 in hypertensive pregnant women by a strict meta-analysis of published human clinical studies. METHODS Based on the principle of Cochrane systematic reviews, Cohort studies in PubMed (Medline), Google Scholar and China Biological Medicine Database (CBM-disc) designed to identify the role of endothelin-1 (ET-1) in the pathophysiology of gestational hypertension and preeclampsia were screened. Review Manager Version 5.0 (Rev-Man 5.0) was applied for statistical analysis. Mean difference and 95% confidence interval (CI) were shown in inverse variance (IV) fixed-effects model or IV random-effects model. RESULTS Sixteen published cohort studies including 1739 hypertensive cases and 409 controls were used in the meta-analysis. ET-1 plasma concentrations were higher in hypertensive pregnant women as compared to the controls (mean difference between groups: 19.02 [15.60~22.44], P < 0.00001,). These finding were driven by severity of hypertension and/or degree of proteinuria. CONCLUSION Plasma ET-1 concentrations are elevated in hypertensive disorders during human pregnancy. In particular women with preeclampsia (hypertensive pregnant women with proteinuria) have substantially elevated plasma ET-1 concentration as compared to pregnant women with normal blood pressure.
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Affiliation(s)
- Yong-Ping Lu
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany.,Department of Nephrology, Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Ahmed Abdallah Hasan
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany.,Department of Biochemistry, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Shufei Zeng
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany.,Department of Nephrology, Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.,Department of Embryology, Medical School of the Jinan University, Guangzhou, China
| | - Berthold Hocher
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany.,Department of Embryology, Medical School of the Jinan University, Guangzhou, China
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Geraldes V, Goncalves-Rosa N, Tavares C, Paton JFR, Rocha I. Reversing gene expression in cardiovascular target organs following chronic depression of the paraventricular nucleus of hypothalamus and rostral ventrolateral medulla in spontaneous hypertensive rats. Brain Res 2016; 1646:109-115. [PMID: 27238462 DOI: 10.1016/j.brainres.2016.05.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Chronic overexpression of an inwardly rectifying potassium channel (hKir2.1) in the paraventricular nucleus of the hypothalamus (PVN) and in the rostral ventrolateral medulla (RVLM) to suppress neuronal excitability, resulted in a long term decrease of blood pressure and sympathetic output in spontaneously hypertensive rats (SHR). OBJECTIVE Evaluate gene expression in end-organs of SHR after a chronic overexpression of hKir2.1 channels in either the PVN or RVLM. METHODS mRNA levels of 16 genes known to be involved with blood pressure regulation were evaluated using RT-PCR in tissues from the heart, common carotid artery and kidney of SHR submitted to chronic depression of PVN and RVLM excitability using a lentiviral vector (LVhKir2.1). RESULTS In SHR hearts in which either the PVN or RVLM were injected with LVhKir2.1, there was a downregulation of angiotensin II receptor 1b (AT1), ATPase, Ca(2+)-transporter, troponin T2 and tropomyosin2 (only in RVLM) relative to the sham group. In the kidney of SHR with LVhKir2.1 injections in PVN and RVLM, angiotensinogen, angiotensin II receptor2 (AT2) and endothelin1 were all upregulated compared to sham. In the carotid artery, endothelin2, endothelin receptor A and B were up-regulated following LVhKir2.1 in to either the PVN or RVLM relative to sham. CONCLUSION Chronic overexpression of hKir2.1 channels in PVN and RVLM, promoted a BP decrease with up-regulation of angiotensinogen and AT2 genes expression in the kidney and down-regulation of AT1 in the heart of SHR. Thus, we demonstrate the potential efficacy of central manipulation to protect against end-organ damage in essential hypertension.
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Affiliation(s)
- Vera Geraldes
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal
| | - Nataniel Goncalves-Rosa
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal
| | - Cristiano Tavares
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal
| | - Julian F R Paton
- School of Physiology & Pharmacology, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Isabel Rocha
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal.
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Davenport AP, Hyndman KA, Dhaun N, Southan C, Kohan DE, Pollock JS, Pollock DM, Webb DJ, Maguire JJ. Endothelin. Pharmacol Rev 2016; 68:357-418. [PMID: 26956245 PMCID: PMC4815360 DOI: 10.1124/pr.115.011833] [Citation(s) in RCA: 462] [Impact Index Per Article: 57.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The endothelins comprise three structurally similar 21-amino acid peptides. Endothelin-1 and -2 activate two G-protein coupled receptors, ETA and ETB, with equal affinity, whereas endothelin-3 has a lower affinity for the ETA subtype. Genes encoding the peptides are present only among vertebrates. The ligand-receptor signaling pathway is a vertebrate innovation and may reflect the evolution of endothelin-1 as the most potent vasoconstrictor in the human cardiovascular system with remarkably long lasting action. Highly selective peptide ETA and ETB antagonists and ETB agonists together with radiolabeled analogs have accurately delineated endothelin pharmacology in humans and animal models, although surprisingly no ETA agonist has been discovered. ET antagonists (bosentan, ambrisentan) have revolutionized the treatment of pulmonary arterial hypertension, with the next generation of antagonists exhibiting improved efficacy (macitentan). Clinical trials continue to explore new applications, particularly in renal failure and for reducing proteinuria in diabetic nephropathy. Translational studies suggest a potential benefit of ETB agonists in chemotherapy and neuroprotection. However, demonstrating clinical efficacy of combined inhibitors of the endothelin converting enzyme and neutral endopeptidase has proved elusive. Over 28 genetic modifications have been made to the ET system in mice through global or cell-specific knockouts, knock ins, or alterations in gene expression of endothelin ligands or their target receptors. These studies have identified key roles for the endothelin isoforms and new therapeutic targets in development, fluid-electrolyte homeostasis, and cardiovascular and neuronal function. For the future, novel pharmacological strategies are emerging via small molecule epigenetic modulators, biologicals such as ETB monoclonal antibodies and the potential of signaling pathway biased agonists and antagonists.
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Affiliation(s)
- Anthony P Davenport
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Kelly A Hyndman
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Neeraj Dhaun
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Christopher Southan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Donald E Kohan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Jennifer S Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David M Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David J Webb
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Janet J Maguire
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
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Czopek A, Moorhouse R, Webb DJ, Dhaun N. Therapeutic potential of endothelin receptor antagonism in kidney disease. Am J Physiol Regul Integr Comp Physiol 2016; 310:R388-97. [DOI: 10.1152/ajpregu.00478.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/20/2015] [Indexed: 11/22/2022]
Abstract
Our growing understanding of the role of the endothelin (ET) system in renal physiology and pathophysiology is from emerging studies of renal disease in animal models and humans. ET receptor antagonists reduce blood pressure and proteinuria in chronic kidney disease and cause regression of renal injury in animals. However, the therapeutic potential of ET receptor antagonism has not been fully explored and clinical studies have been largely limited to patients with diabetic nephropathy. There remains a need for more work in nondiabetic chronic kidney disease, end-stage renal disease (patients requiring maintenance dialysis and those with a functioning kidney transplant), ischemia reperfusion injury, and sickle cell disease. The current review summarizes the most recent advances in both preclinical and clinical studies of ET receptor antagonists in the field of kidney disease.
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Affiliation(s)
- Alicja Czopek
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
| | - Rebecca Moorhouse
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
| | - David J. Webb
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
| | - Neeraj Dhaun
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
- Department of Renal Medicine, Royal Infirmary of Edinburgh, United Kingdom
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Cacioppo JA, Koo Y, Lin PCP, Gal A, Ko C. Generation and characterization of an endothelin-2 iCre mouse. Genesis 2015; 53:245-56. [PMID: 25604013 DOI: 10.1002/dvg.22845] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/14/2015] [Accepted: 01/15/2015] [Indexed: 12/16/2022]
Abstract
A novel transgenic mouse line that expresses codon-improved Cre recombinase (iCre) under regulation of the Endothelin-2 gene (edn2) promoter was developed for the conditional deletion of genes in Endothelin-2 lineage cells and for the spatial and temporal localization of Endothelin-2 expression. Endothelin-2 (EDN2, ET-2, previously VIC) is a transcriptionally regulated 21 amino acid peptide implicated in vascular homeostasis, and more recently in female reproduction, gastrointestinal function, immunology, and cancer pathogenesis that acts through membrane receptors and G-protein signaling. A cassette (edn2-iCre) was constructed that contained iCre, a polyadenylation sequence, and a neomycin selection marker in front of the endogenous start codon of the edn2 gene in a mouse genome BAC clone. The cassette was introduced into the C57BL/6 genome by pronuclear injection, and two lines of edn2-iCre positive mice were produced. The edn2-iCre mice were bred with ROSA26-lacZ and Ai9 reporter mice to visualize areas of functional iCre expression. Strong expression was seen in the periovulatory ovary, stomach and small intestine, and colon. Uniquely, we report punctate expression in the corneal epithelium, the liver, the lung, the pituitary, the uterus, and the heart. In the embryo, expression is localized in developing hair follicles and the dermis. Therefore, edn2-iCre mice will serve as a novel line for conditional gene deletion in these tissues.
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Affiliation(s)
- Joseph A Cacioppo
- Comparative Biosciences, College of Veterinary Medicine, University of Illinois, Urbana-Campaign, Illinois
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Reichetzeder C, Tsuprykov O, Hocher B. Endothelin receptor antagonists in clinical research — Lessons learned from preclinical and clinical kidney studies. Life Sci 2014; 118:141-8. [DOI: 10.1016/j.lfs.2014.02.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 01/18/2014] [Accepted: 02/19/2014] [Indexed: 11/25/2022]
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Association of endothelin-1 gene polymorphisms with the clinical phenotype in primary nephrotic syndrome of children. Life Sci 2014; 118:446-50. [DOI: 10.1016/j.lfs.2014.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/09/2014] [Accepted: 04/07/2014] [Indexed: 12/19/2022]
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10
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De Mey JGR, Vanhoutte PM. End o' the line revisited: moving on from nitric oxide to CGRP. Life Sci 2014; 118:120-8. [PMID: 24747136 DOI: 10.1016/j.lfs.2014.04.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 04/04/2014] [Accepted: 04/05/2014] [Indexed: 12/24/2022]
Abstract
When endothelin-1(ET-1) was discovered it was hailed as the prototypical endothelium-derived contracting factor (EDCF). However, over the years little evidence emerged convincingly demonstrating that the peptide actually contributes to moment-to-moment changes in vascular tone elicited by endothelial cells. This has been attributed to the profound inhibitory effect of nitric oxide (NO) on both the production (by the endothelium) and the action (on vascular smooth muscle) of ET-1. Hence, the peptide is likely to initiate acute changes in vascular diameter only under extreme conditions of endothelial dysfunction when the NO bioavailability is considerably reduced if not absent. The present essay discusses whether or not this concept should be revised, in particular in view of the potent inhibitory effect exerted by calcitonin gene related peptide (CGRP) released from sensorimotor nerves on vasoconstrictor responses to ET-1.
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Affiliation(s)
- Jo G R De Mey
- Institute of Molecular Medicine, University of South Denmark, Odense, Denmark; Cardiovascular Research Institute Maastricht, Maastricht, the Netherlands
| | - Paul M Vanhoutte
- Institute of Molecular Medicine, University of South Denmark, Odense, Denmark; Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, University of Hong Kong, Hong Kong, China.
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Baretella O, Chung SK, Barton M, Xu A, Vanhoutte PM. Obesity and heterozygous endothelial overexpression of prepro-endothelin-1 modulate responsiveness of mouse main and segmental renal arteries to vasoconstrictor agents. Life Sci 2014; 118:206-12. [PMID: 24412387 DOI: 10.1016/j.lfs.2013.12.214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 12/11/2013] [Accepted: 12/27/2013] [Indexed: 11/19/2022]
Abstract
AIMS Levels of the endothelium-derived peptide endothelin-1 (ET-1) are elevated in obese humans, and ET-1 mediated vascular tone is increased. Renal arterial smooth muscle is highly responsive to ET-1. Whether or not endothelium-derived ET-1 affects contractions of the renal artery under normal conditions or in obesity is unknown. The present study was designed to investigate whether or not overexpression of endogenous ET-1 in the endothelium affects the responsiveness of the main and segmental renal arteries differently in obesity. MAIN METHODS Mice with tie-1 promoter-driven endothelium-restricted heterozygous overexpression of preproendothelin-1 were used (TET(het)). Obesity was induced in TET(het) mice and wild-type (WT) littermates by feeding a high fat diet for 30 weeks; lean controls were kept on standard chow. The renal arteries were studied in wire myographs testing contractions (in the presence of l-NAME) to ET-1, serotonin, and U46619. KEY FINDINGS Contractions to ET-1 were comparable between groups in main renal arteries, but augmented in segmental preparations from obese mice. Serotonin-induced responses were enhanced in obese TET(het) mice renal arteries compared to lean controls. Concentration-contraction curves to U46619 were shifted significantly to the left in main renal arteries of obese animals, and the maximal response was significantly increased between lean and obese TET(het) mice. SIGNIFICANCE These results indicate an augmented responsiveness of main renal arteries in obesity particularly to TP receptor activation. When combined with endothelial ET-1 overexpression this effect is even more pronounced, which may help to gain further insights into the mechanisms of hypertension in obesity.
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Affiliation(s)
- Oliver Baretella
- Department of Pharmacology & Pharmacy, and State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong,China
| | - Sookja K Chung
- Department of Anatomy, The University of Hong Kong, Hong Kong,China; Research Centre of Heart, Brain, Hormone & Healthy Aging, The University of Hong Kong, Hong Kong,China
| | - Matthias Barton
- Molecular Internal Medicine, University of Zürich, 8057 Zürich, Switzerland
| | - Aimin Xu
- Department of Pharmacology & Pharmacy, and State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong,China; Research Centre of Heart, Brain, Hormone & Healthy Aging, The University of Hong Kong, Hong Kong,China; Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Paul M Vanhoutte
- Department of Pharmacology & Pharmacy, and State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong,China; Research Centre of Heart, Brain, Hormone & Healthy Aging, The University of Hong Kong, Hong Kong,China.
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Herrera VLM, Pasion KA, Moran AM, Ruiz-Opazo N. Worse renal disease in postmenopausal F2[Dahl S x R]-intercross rats: detection of novel QTLs affecting hypertensive kidney disease. PLoS One 2013; 8:e56096. [PMID: 23393608 PMCID: PMC3564915 DOI: 10.1371/journal.pone.0056096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 01/09/2013] [Indexed: 11/29/2022] Open
Abstract
The prevalence of hypertension increases after menopause with 75% of postmenopausal women developing hypertension in the United States, along with hypertensive end organ diseases. While human and animal model studies have indicated a protective role for estrogen against cardiovascular disease and glomerulosclerosis, clinical studies of hormone replacement therapy in postmenopausal women have shown polar results with some improvement in hypertension but worsening of hypertensive kidney disease, or no effect at all. These observations suggest that the pathogenesis of postmenopausal hypertension and its target organ complications is more complex than projected, and that loss of endogenous estrogens induces epigenetic changes that alter genetic susceptibility to end-organ complications per se resulting in pathogenetic mechanisms beyond correction by hormone replacement. We studied postmenopausal-induced changes in renal disease and performed a total genome scan for quantitative trait loci (QTLs) affecting kidney disease in postmenopausal 16m-old F2[Dahl S x R]-intercross female rats. We used glomerular injury score (GIS) as quantitative trait. We compared QTLs amongst premenopausal, ovariectomized and postmenopausal F2[Dahl S x R]-intercross rats using identical phenotype characterization. Postmenopausal F2[Dahl S x R]-intercross rats exhibited increased hypertensive glomerulosclerosis (P<0.01) and equivalent levels of kidney disease when compared to premenopausal and ovariectomized F2[Dahl S x R]-intercross rats respectively. We detected three significant to highly significant GIS-QTLs (GIS-pm1 on chromosome 4, LOD 3.54; GIS-pm2 on chromosome 3, LOD 2.72; GIS-pm3 on chromosome 5, LOD 2.37) and two suggestive GIS-QTLs (GIS-pm4 on chromosome 2, LOD 1.70; GIS-pm5 on chromosome 7, LOD 1.28), all of which were unique to this postmenopausal population. Detection of increased renal disease phenotype in postmenopausal and ovariectomized subjects suggests a protective role of ovarian hormones. Furthermore, the detection of distinct GIS-QTLs in postmenopausal intercross female rats suggests that distinct genetic mechanisms underlie hypertensive glomerulosclerosis in premenopausal and postmenopausal states.
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Affiliation(s)
- Victoria L. M. Herrera
- Section of Cardiovascular Medicine, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Khristine A. Pasion
- Section of Cardiovascular Medicine, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Ann Marie Moran
- Section of Cardiovascular Medicine, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Nelson Ruiz-Opazo
- Section of Cardiovascular Medicine, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Ling L, Maguire JJ, Davenport AP. Endothelin-2, the forgotten isoform: emerging role in the cardiovascular system, ovarian development, immunology and cancer. Br J Pharmacol 2013; 168:283-95. [PMID: 22118774 PMCID: PMC3572556 DOI: 10.1111/j.1476-5381.2011.01786.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 10/14/2011] [Accepted: 10/31/2011] [Indexed: 12/11/2022] Open
Abstract
Endothelin-2 [ET-2; also known as vasoactive intestinal contractor (VIC), in rodents] differs from endothelin-1 (ET-1) by only two amino acids, and unlike the third isoform, endothelin-3 (ET-3), it has the same affinity as ET-1 for both ET(A) and ET(B) receptors. It is often assumed that ET-2 would mimic the actions of the more abundant ET-1 and current pharmacological interventions used to inhibit the ET system would also block the actions of ET-2. These assumptions have focused research on ET-1 with ET-2 studied in much less detail. Recent research suggests that our understanding of the ET family requires re-evaluation. Although ET-2 is very similar in structure as well as pharmacology to ET-1, and may co-exist in the same tissue compartments, there is converging evidence for an important and distinct ET-2 pathway. Specifically is has been demonstrated that ET-2 has a key role in ovarian physiology, with ET-2-mediated contraction proposed as a final signal facilitating ovulation. Furthermore, ET-2 may also have a pathophysiological role in heart failure, immunology and cancer. Comparison of ET-2 versus ET-1 mRNA expression suggests this may be accomplished at the level of gene expression but differences may also exist in peptide synthesis by enzymes such as endothelin converting enzymes (ECEs) and chymase, which may allow the two pathways to be distinguished pharmacologically and become separate drug targets. LINKED ARTICLES This article is part of a themed section on Endothelin. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.168.issue-1.
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Affiliation(s)
- Lowell Ling
- Clinical Pharmacology Unit, University of Cambridge, Cambridge, UK
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14
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Saleh MA, Boesen EI, Pollock JS, Savin VJ, Pollock DM. Endothelin-1 increases glomerular permeability and inflammation independent of blood pressure in the rat. Hypertension 2010; 56:942-9. [PMID: 20823379 DOI: 10.1161/hypertensionaha.110.156570] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Endothelin (ET) 1 is a potent vasoactive peptide implicated in the pathogenesis of hypertension and renal disease. The aim of the current study was to test the hypotheses that ET-1 increases albumin permeability of glomeruli isolated from normal rats and that chronic ET-1 infusion will increase glomerular permeability and inflammation independent of blood pressure. Glomerular permeability to albumin was determined from the change in glomerular volume induced by exposing isolated glomeruli to oncotic gradients. Incubation of glomeruli taken from normal rats with ET-1 at a concentration that did not produce direct glomerular contraction (1 nmol/L) significantly increased glomerular permeability to albumin, reaching a maximum after 4 hours. Chronic ET-1 infusion for 2 weeks in Sprague-Dawley rats significantly increased glomerular permeability to albumin and nephrin excretion rate, effects that were attenuated in rats given an ET(A) receptor antagonist (ABT-627, 5 mg/kg per day). Urinary protein and albumin excretion and mean arterial pressure (telemetry) were not changed by ET-1 infusion. Acute incubation of glomeruli isolated from ET-1-infused rats with the selective ET(A) antagonist significantly reduced glomerular permeability to albumin, an effect not observed with acute treatment with a selective ET(B) antagonist. Chronic ET-1 infusion increased glomerular and plasma soluble intercellular adhesion molecule 1 and monocyte chemoattractant protein 1 and elevated the number of macrophages and lymphocytes in renal cortices (ED-1 and CD3-positive staining, respectively). These effects were all attenuated in rats given an ET(A) selective antagonist. These data support the hypothesis that ET-1 directly increases glomerular permeability to albumin and renal inflammation via ET(A) receptor activation independent of changes in arterial pressure.
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Affiliation(s)
- Mohamed A Saleh
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912-2500, USA
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15
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Liefeldt L, Rylski B, Walcher F, Manhart J, Kron S, Rosenke YW, Paul M, Neumayer HH, Amann K, Peters H. Effects of transgenic endothelin-2 overexpression on diabetic cardiomyopathy in rats. Eur J Clin Invest 2010; 40:203-10. [PMID: 20100233 DOI: 10.1111/j.1365-2362.2009.02251.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Transgenic overexpression of human endothelin-2 in rats was used to characterize the contribution of endothelin to diabetic cardiomyopathy. MATERIALS AND METHODS Diabetes mellitus was induced by streptozotocin in transgenic rats and transgene-negative controls. Nondiabetic animals were included as well to form a 4-group study design. Heart morphological and molecular alterations were analysed following 6 months of hyperglycaemia. RESULTS Plasma endothelin concentrations were significantly higher in both transgenic groups than in wild-type groups (nondiabetic: 3.5 +/- 0.4 vs. 2.1 +/- 0.2, P < 0.05; diabetic: 4.5 +/- 0.4 vs. 2.5 +/- 0.4 fmol mL(-1), P < 0.01). Diabetes induced cardiac hypertrophy in both wild-type and transgenic rats and showed the highest myocardial interstitial tissue volume density in diabetic transgenic rats (1.5 +/- 0.07%) as compared with nondiabetic transgenic (1.1 +/- 0.03%), nondiabetic wild-type (0.8 +/- 0.01%) and diabetic wild-type rats (1.1 +/- 0.03%; P < 0.01 for all comparisons). A similar pattern with the most severe changes in the enothelin-2 transgenic, diabetic animals was observed for hypertrophy of the large coronary arteries and the small intramyocardial arterioles respectively. Cardiac mRNA expression of endothelin-1, endothelin receptors type A and B were altered in some degree by diabetes or transgenic overexpression of endothelin-2, but not in a uniform manner. Blood pressure did not differ between any of the four groups. CONCLUSIONS Overexpression of the human endothelin-2 gene in rats aggravates diabetic cardiomyopathy by more severe coronary and intramyocardial vessel hypertrophy and myocardial interstitial fibrosis. This transgenic intervention provides further and independent support for a detrimental, blood pressure-independent role of endothelins in diabetic cardiac changes.
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Affiliation(s)
- L Liefeldt
- Department of Nephrology, Charité- Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
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16
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von Websky K, Heiden S, Pfab T, Hocher B. Pathophysiology of the endothelin system - lessons from genetically manipulated animal models. Eur J Med Res 2009; 14:1-6. [PMID: 19258203 PMCID: PMC3352198 DOI: 10.1186/2047-783x-14-1-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Shortly after discovery of ET-1 in 1988, the entire endothelin system was characterized. The endothelin system consists of the three peptides ET-1, ET-2 and ET-3, their G-protein-coupled receptors endothelin receptor A and B (ETRA and ETRB) and the two endothelin-converting enzymes (ECE-1 and ECE-2). Genetically modified animal models are an important tool in biomedical research. Here we describe the key findings obtained from genetically modified animal models either over-expressing compounds of the ET system or lacking these compounds (knockout mice). Results from the different transgenic and knockout models disclose that the ET system plays a major role in embryonic development. Two ET system-dependent neural crest-driven developmental pathways become obvious: one of them being an ET-1/ETAR axis, responsible for cardio-renal function and development as well as cranial development; the other seems to be an ET-3/ETBR mediated signalling pathway. Mutations within this axis are associated with disruptions in epidermal melanocytes and enteric neurons. These findings led to the discovery of similar findings in humans with Hirschsprung disease. In adult life the ET system is most important in the cardiovascular system and plays a role in fibrotic remodelling of the heart, lung and kidney as well as in the regulation of water and salt excretion.
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Affiliation(s)
- K von Websky
- Center for Cardiovascular Research/Department of Pharmacology and Toxicology, Charité, Hessische Str. 3-4, 10115 Berlin, Germany
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18
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Quaschning T, Voss F, Herzfeld S, Relle K, Kalk P, Godes M, Pfab T, Kraemer-Guth A, Bonz AW, Theuring F, Galle J, Hocher B. Lack of iNOS Impairs Endothelial Function in Endothelin-1 Transgenic Mice. Kidney Blood Press Res 2008; 31:127-34. [DOI: 10.1159/000124285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Accepted: 02/11/2008] [Indexed: 11/19/2022] Open
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Quaschning T, Voss F, Relle K, Kalk P, Vignon-Zellweger N, Pfab T, Bauer C, Theilig F, Bachmann S, Kraemer-Guth A, Wanner C, Theuring F, Galle J, Hocher B. Lack of Endothelial Nitric Oxide Synthase Promotes Endothelin-Induced Hypertension: Lessons from Endothelin-1 Transgenic/Endothelial Nitric Oxide Synthase Knockout Mice. J Am Soc Nephrol 2007; 18:730-40. [PMID: 17287431 DOI: 10.1681/asn.2006050541] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Endothelin-1 (ET-1) is one of the most potent biologic vasoconstrictors. Nevertheless, transgenic mice that overexpress ET-1 exhibit normal BP. It was hypothesized that vascular effects of ET-1 may be antagonized by an increase of the endothelial counterpart of ET-1, nitric oxide (NO), which is produced by the endothelial NO synthase (eNOS). Therefore, cross-bred animals of ET transgenic mice (ET+/+) and eNOS knockout (eNOS-/-) mice and were generated, and BP and endothelial function were evaluated in these animals. Endothelium-dependent and -independent vascular function was assessed as relaxation/contraction of isolated preconstricted aortic rings. The tissue ET and NO system was determined in aortic rings by quantitative real-time PCR and Western blotting. Systolic BP was similar in ET+/+ and wild-type (WT) mice but was significantly elevated in eNOS-/- mice (117 +/- 4 mmHg versus 94 +/- 6 mmHg in WT mice; P < 0.001) and even more elevated in ET+/+ eNOS-/- cross-bred mice (130 +/- 4 mmHg; P < 0.05 versus eNOS-/-). Maximum endothelium-dependent relaxation was enhanced in ET+/+ mice (103 +/- 6 versus 87 +/- 4% of preconstriction in WT littermates; P < 0.05) and was completely blunted in eNOS-/- (-3 +/- 4%) and ET+/+ eNOS-/- mice (-4 +/- 4%), respectively. Endothelium-independent relaxation was comparable among all groups. Quantitative real-time PCR as well as Western blotting revealed an upregulation of the aortic ET(A) and ET(B) receptors in ET+/+ eNOS-/-, whereas eNOS was absent in aortic rings of eNOS-/- and ET+/+ eNOS-/- mice. ET-1 aortic tissue concentrations were similar in WT mice and ET+/+ eNOS-/- mice most probably as a result of an enhanced clearance of ET-1 by the upregulated ET(B) receptor. These data show for the first time that in transgenic mice that overexpress human ET-1, additional knockout of eNOS results in a further enhancement of BP as compared with eNOS-/- mice. The human ET+/+ eNOS-/- mice therefore represent a novel model of hypertension as a result of an imbalance between the vascular ET-1 and NO systems.
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Affiliation(s)
- Thomas Quaschning
- Department of Nephrology, University Hospital of Freiburg, Freiburg, Germany
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20
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Reiterová J, Merta M, Stekrová J, Cabartová Z, Cibulka R, Maixnerová D, Rysavá R, Ríhová Z, Tesar V, Motán J. Influence of endothelin-1 gene polymorphisms on the progression of autosomal dominant polycystic kidney disease. Kidney Blood Press Res 2006; 29:182-8. [PMID: 16943682 DOI: 10.1159/000095504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Accepted: 07/18/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIM A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). The variability cannot be fully explained by the genetic heterogeneity of the disease. Endothelin-1 (ET-1) has been suggested to be a major promoting factor in renal diseases. The role of the ET-1 gene locus (EDN1) in the renal function in the general nondiabetic population was evaluated. We examined the influence of three single-nucleotide polymorphisms of the ET-1 gene (EDN1)--K198N, 3A/4A, and T-1370G--on the progression of ADPKD towards end-stage renal disease (ESRD). METHODS Two hundred and five ADPKD patients (113 males and 92 females) who had reached ESRD were analyzed. The patients were divided into three groups: (1) 48 patients (23 males and 25 females) with ESRD later than 63 years of age (slow progressors), (2) 74 patients (41 males and 33 females) with ESRD before 45 years of age (rapid progressors), and (3) 83 patients (49 males and 34 females) with ESRD between 45 and 63 years old. DNA samples from collected blood were genotyped for three single-nucleotide polymorphisms of EDN1: K198N, 3A/4A, and T-1370G. Haplotype analysis was also done in 200 healthy individuals. We compared the frequencies of the different genotypes between the groups of slow and rapid progressors and the ages at the time of ESRD regarding the EDN1 genotypes. RESULTS The EDN1 genotype distribution showed no differences among the groups of slow progressors, rapid progressors, the ADPKD group with ESRD between 45 and 63 years old, and the control group. Comparing the ages of ESRD of all patients, we did not find significant differences with regard to the different genotypes. Furthermore, we compared the combinations of the different haplotypes and the ages at the time of ESRD. We found no differences in ages at the time of ESRD in patients with different haplotypes in the endothelin promoter (T-1370G) in combination with 3A/4A or K198N polymorphisms. Comparing the ages at the time of ESRD in patients with different 3A/4A and K198N haplotypes, we found a significantly lower age at the time of ESRD (47.1 +/- 8.7 years) in the carriers of the 4A allele in combination with the 198N allele (4A/4A, 3A/4A + 198KN,NN) than in the carriers of the 4A allele homozygous for the K198 allele (52.9 +/- 10.9 years; 4A/4A, 3A/4A + 198KK; t test: p < 0.01) and in the carriers of the 198N allele homozygous for the 3A allele (53 +/- 11.2 years; 3A/3A + 198KN,NN; t test: p < 0.05). CONCLUSIONS We excluded an effect of K198N, 3A/4A, and T-1370G polymorphisms of EDN1 on the progression of ADPKD. However, a deleterious effect of the combination of 4A and 198N alleles of EDN1 was observed in APKDK individuals.
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Affiliation(s)
- J Reiterová
- Department of Nephrology, 1st Medical Faculty, Charles University, Prague, Czech Republic.
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Pfab T, Thöne-Reineke C, Theilig F, Lange I, Witt H, Maser-Gluth C, Bader M, Stasch JP, Ruiz P, Bachmann S, Yanagisawa M, Hocher B. Diabetic Endothelin B Receptor–Deficient Rats Develop Severe Hypertension and Progressive Renal Failure. J Am Soc Nephrol 2006; 17:1082-9. [PMID: 16495378 DOI: 10.1681/asn.2005080833] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The endothelin (ET) system has been implicated in the pathogenesis of diabetic nephropathy. The role of the ET-B receptor (ETBR) is still unclear. The effect of ETBR deficiency on the progression of diabetic nephropathy in a streptozotocin model was analyzed in four groups: (1) Homozygous ETBR-deficient (ETBRd) diabetic rats, (2) ETBRd rats, (3) diabetic controls, and (4) wild-type controls. BP and kidney function were measured for 10 wk, followed by biochemical and histologic analysis of the kidneys. The study demonstrates that ETBRd diabetic rats on a normal-sodium diet develop severe hypertension, albuminuria, and a mild reduction of creatinine clearance. The strong BP rise seems not to be caused by activation of the renin-angiotensin-aldosterone system or by suppression of the nitric oxide system. Elevated plasma ET-1, possibly reflecting a reduced ETBR-dependent clearance, seems to cause the severe hypertension via the ETA receptor. The results do not support the hypothesis that a reduction of ETBR activity inhibits the progression of diabetic nephropathy. The study demonstrates for the first time that the combination of diabetes and ETBR deficiency causes severe low-renin hypertension with progressive renal failure.
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MESH Headings
- Animals
- Blood Pressure
- Creatinine/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Experimental/physiopathology
- Diabetic Nephropathies/etiology
- Disease Models, Animal
- Endothelin-1/blood
- Hypertension/etiology
- Hypertension/pathology
- Hypertension/physiopathology
- Kidney/pathology
- Kidney/physiopathology
- Kidney Failure, Chronic/etiology
- Kidney Failure, Chronic/pathology
- Kidney Failure, Chronic/physiopathology
- Myocardium/pathology
- Rats
- Rats, Mutant Strains
- Receptor, Endothelin A/physiology
- Receptor, Endothelin B/deficiency
- Receptor, Endothelin B/genetics
- Receptor, Endothelin B/physiology
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Affiliation(s)
- Thiemo Pfab
- Center for Cardiovascular Research/Institute of Pharmacology, Charité Mitte, Hessische Strasse 3-4, 10115 Berlin, Germany
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Abstract
The need to translate genes to function has positioned the rat as an invaluable animal model for genomic research. The significant increase in genomic resources in recent years has had an immediate functional application in the rat. Many of the resources for translational research are already in place and are ready to be combined with the years of physiological knowledge accumulated in numerous rat models, which is the subject of this perspective. Based on the successes to date and the research projects under way to further enhance the infrastructure of the rat, we also project where research in the rat will be in the near future. The impact of the rat genome project has just started, but it is an exciting time with tremendous progress.
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Affiliation(s)
- Jozef Lazar
- Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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23
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Schrijvers BF, De Vriese AS, Flyvbjerg A. From hyperglycemia to diabetic kidney disease: the role of metabolic, hemodynamic, intracellular factors and growth factors/cytokines. Endocr Rev 2004; 25:971-1010. [PMID: 15583025 DOI: 10.1210/er.2003-0018] [Citation(s) in RCA: 242] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
At present, diabetic kidney disease affects about 15-25% of type 1 and 30-40% of type 2 diabetic patients. Several decades of extensive research has elucidated various pathways to be implicated in the development of diabetic kidney disease. This review focuses on the metabolic factors beyond blood glucose that are involved in the pathogenesis of diabetic kidney disease, i.e., advanced glycation end-products and the aldose reductase system. Furthermore, the contribution of hemodynamic factors, the renin-angiotensin system, the endothelin system, and the nitric oxide system, as well as the prominent role of the intracellular signaling molecule protein kinase C are discussed. Finally, the respective roles of TGF-beta, GH and IGFs, vascular endothelial growth factor, and platelet-derived growth factor are covered. The complex interplay between these different pathways will be highlighted. A brief introduction to each system and description of its expression in the normal kidney is followed by in vitro, experimental, and clinical evidence addressing the role of the system in diabetic kidney disease. Finally, well-known and potential therapeutic strategies targeting each system are discussed, ending with an overall conclusion.
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Affiliation(s)
- Bieke F Schrijvers
- Medical Department M/Medical Research Laboratories, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, DK-8000 Aarhus C, Denmark
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Reply. J Hypertens 2004. [DOI: 10.1097/00004872-200409000-00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Maki S, Miyauchi T, Kakinuma Y, Sakai S, Kobayashi T, Sugiyama F, Fukamizu A, Goto K, Yamaguchi I. The endothelin receptor antagonist ameliorates the hypertensive phenotypes of transgenic hypertensive mice with renin-angiotensin genes and discloses roles of organ specific activation of endothelin system in transgenic mice. Life Sci 2004; 74:1105-18. [PMID: 14687651 DOI: 10.1016/j.lfs.2003.07.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelin (ET)-1 and ET-2 are potent vasoconstrictor peptides with mitogenic activity. In this study, we investigated roles of ET system in renin-angiotensin system (RAS)-mediated hypertension, using transgenic hypertensive mice (THM) with over-expression of both human renin and angiotensinogen genes. In the first step, it was revealed that expression of ET system was locally enhanced, i.e. increases in cardiac preproET-1 mRNA and renal preproET-2 mRNA in THM, compared with the control (wild type) mice. In the next step, we studied the chronic effects of an ET antagonist (SB209670) on THM. Blood pressure (BP) in THM was significantly higher than that in the normal mice during the investigation. However, in the later phase of the study, from 12 to 20 weeks of treatment, THM receiving SB 209670 showed significantly lower BP than that in THM receiving saline. SB 209670 treatment for 20 weeks significantly attenuated phenotypes of cardiac hypertrophy, vascular wall thickening and hypertensive nephropathy observed in THM, suggesting that the ETA/B receptor antagonist is also effective even in the extraordinarily activated RAS condition. These findings suggest that organ specifically activated ET system in THM develops the phenotypes, hypertension, cardiac hypertrophy, and hypertensive nephropathy.
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Affiliation(s)
- Shinichi Maki
- Cardiovascular Division, Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
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Rothermund L, Kossmehl P, Neumayer HH, Paul M, Kreutz R. Renal damage is not improved by blockade of endothelin receptors in primary renin-dependent hypertension. J Hypertens 2003; 21:2389-97. [PMID: 14654760 DOI: 10.1097/00004872-200312000-00028] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Secondary activation of the renin-angiotensin system plays a major role in the progression of chronic nephropathies, and blockade of endothelin (ET) receptors has been shown to confer nephroprotection in experimental models of proteinuric renal disease. We tested the nephroprotective potential of selective endothelin A receptor (ETA) and non-selective ETA and endothelin B (ETA/B) receptor blockade in the TGR(mRen2)27 transgenic rat model with renin-dependent hypertension (Ren2). DESIGN Ren2 animals were treated between 10 and 30 weeks of age with the selective ETA receptor antagonist darusentan (Ren2-ETA) and the ETA/B receptor antagonist Lu420627 (Ren2-ETA/B), and compared with transgene negative Sprague-Dawley (SD) controls. Since the elevated systolic blood pressure in Ren2 was not affected in either Ren2-ETA or Ren2-ETA/ETB, an additional Ren-2 group was treated with a non-antihypertensive dose of the angiotensin II type 1 receptor blocker eprosartan (Ren2-AT1). RESULTS During the 20-week observation period 35% of untreated Ren2, 30% of Ren2-ETA/B, 50% of Ren2-ETA, and 83% of Ren2-AT1 animals survived compared with 100% of SD rats. Renal endothelin-1 mRNA expression and proteinuria (4.1-fold) were significantly elevated in Ren2 compared with SD rats (P < 0.05, respectively). Proteinuria was normalized to SD control levels in Ren2-AT1 (P < 0.05) but increased further in Ren2-ETA (7.7-fold) and Ren2-ETA/B (15-fold) (P < 0.05, respectively). Glomerulosclerosis, tubulointerstitial damage and renal osteopontin mRNA expression were reduced in Ren2-AT1 (P < 0.05, respectively) but remained unchanged or increased further in Ren2-ETA and Ren2-ETA/B compared with Ren2. CONCLUSION ET receptor blockade fails to improve renal damage and mortality in primary renin-dependent hypertension.
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MESH Headings
- Acrylates/therapeutic use
- Animals
- Antihypertensive Agents/pharmacology
- Aspartic Acid Endopeptidases/biosynthesis
- Aspartic Acid Endopeptidases/drug effects
- Blood Pressure/drug effects
- Disease Models, Animal
- Endothelin A Receptor Antagonists
- Endothelin B Receptor Antagonists
- Endothelin-1/biosynthesis
- Endothelin-1/drug effects
- Endothelin-Converting Enzymes
- Glomerulosclerosis, Focal Segmental/metabolism
- Glomerulosclerosis, Focal Segmental/physiopathology
- Glomerulosclerosis, Focal Segmental/prevention & control
- Hypertension, Renal/metabolism
- Hypertension, Renal/physiopathology
- Imidazoles/therapeutic use
- Kidney/metabolism
- Kidney/pathology
- Male
- Metalloendopeptidases
- Models, Cardiovascular
- Nephritis, Interstitial/metabolism
- Nephritis, Interstitial/physiopathology
- Nephritis, Interstitial/prevention & control
- Organ Size/drug effects
- Osteopontin
- Proteinuria/urine
- RNA, Messenger/biosynthesis
- RNA, Messenger/drug effects
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin A/metabolism
- Receptor, Endothelin B/metabolism
- Renin/metabolism
- Renin-Angiotensin System/drug effects
- Sialoglycoproteins/biosynthesis
- Sialoglycoproteins/drug effects
- Systole/drug effects
- Thiophenes
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Affiliation(s)
- Lars Rothermund
- Institut für Klinische Pharmakologie und Toxikologie and Medizinische Klinik IV Nephrologie, Campus Benjamin Franklin, Charité Universitätsmedizin Berlin, Freie Universität Berlin, Germany
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27
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Morgera S, Schlenstedt J, Hambach P, Giessing M, Deger S, Hocher B, Neumayer HH. Combined ETA/ETB receptor blockade of human peritoneal mesothelial cells inhibits collagen I RNA synthesis. Kidney Int 2003; 64:2033-40. [PMID: 14633125 DOI: 10.1046/j.1523-1755.2003.00320.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Peritoneal fibrosis is a serious complication of peritoneal dialysis; however, the mechanisms are poorly understood. We studied osmolarity and physical stress-induced effects on collagen I RNA synthesis in human peritoneal mesothelial cells (HPMCs) and focused on endothelin as a possible mediator. METHODS HPMCs were grown in a medium containing either d-glucose or glycerol to analyze the impact of osmolarity on mesothelial endothelin-1 (ET-1) release and on collagen I RNA synthesis [reverse transcription-polymerase chain reaction (RT-PCR)]. A cellular model of nonlaminar fluid shear stress and cellular stretch was used to analyze the effects of physical forces. To neutralize the endothelin effects, a combined ETA/ETB receptor antagonist (LU 302 872) was chosen. RESULTS Glucose, but not glycerol, increased mesothelial ET-1 release in a concentration and time-dependent manner (P < 0.05 vs. controls). Collagen I RNA synthesis was significantly higher in glucose-challenged cell cultures (P < 0.05 vs. controls). The glucose-mediated collagen I RNA synthesis was completely inhibited by adding the combined ETA/ETB receptor antagonist to the medium. Fluid shear stress, but not cellular stretch, led to a significant increase in the mesothelial ET-1 release (P < 0.005 vs. controls) and collagen I RNA synthesis (P < 0.05 vs. controls). LU 302 872 completely inhibited these effects. CONCLUSION We found that glucose and fluid shear stress are potent stimuli for ET-1 release and collagen I RNA synthesis in a model cellular system. Although our system is highly artificial, our findings raise the hypothesis that similar effects may occur in the peritoneal membranes of peritoneal dialysis patients and suggest that endothelin might be involved.
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Affiliation(s)
- Stanislao Morgera
- Department of Nephrology, Charité, Humboldt University of Berlin, Berlin, Germany.
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28
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Pinto-Sietsma SJ, Herrmann SM, Schmidt-Petersen K, Niu T, Hillege HL, Janssen WMT, de Zeeuw D, de Jong P, Kreutz R. Role of the Endothelin-1 Gene Locus for Renal Impairment in the General Nondiabetic Population. J Am Soc Nephrol 2003; 14:2596-602. [PMID: 14514737 DOI: 10.1097/01.asn.0000089827.03201.8e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
ABSTRACT. A decreased GFR in the range of mild renal insufficiency and an increased urinary albumin excretion (UAE) rate in the range of microalbuminuria are important cardiovascular risk factors. Endothelin-1 (ET-1) has been suggested to be a major disease promoting factor in renal disease. The role of theET-1gene locus (EDN1) for renal function in the general nondiabetic population was evaluated. To explore the overall relevance of EDN1, two suitable single-nucleotide polymorphisms, EDN1 K198N and EDN1 T-1370G, were selected, and haplotype analysis was performed. Determined were genotypes in 7291 nondiabetic subjects from the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study. Genetic analysis was related to UAE and GFR as continuous variables and to microalbuminuria and diminished filtration as dichotomous traits. In a logistic regression analysis, no significant higher risk for increased UAE, microalbuminuria, decreased GFR, or diminished filtration could be observed for either single-nucleotide polymorphism separately. Haplotype analysis revealed that individuals with the homozygous G-N haplotype (compound EDN1 −1370GG/198NN genotype) have a lower GFR than the remaining subjects (P< 0.05) and exhibit a significant higher risk for the presence of a diminished filtration (relative risk, 2.4; 95% confidence interval, 1.07 to 5.33;P< 0.05). Further analysis demonstrated no association between this haplotype and UAE or plasma ET-1 levels. Although a functional relevance of the EDN1 G-N haplotype itself remains unclear, the data demonstrate that genetic variation at the EDN1 locus has a significant effect on glomerular filtration but not on UAE in the general nondiabetic population. E-mail: Kreutz@medizin.fu-berlin.de
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Affiliation(s)
- Sara-Joan Pinto-Sietsma
- Department of Internal Medicine, Division of Nephrology, Academic Hospital Groningen, University Groningen, Groningen, The Netherlands
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29
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Moreau P, Schiffrin EL. Role of endothelins in animal models of hypertension: focus on cardiovascular protection. Can J Physiol Pharmacol 2003; 81:511-21. [PMID: 12839263 DOI: 10.1139/y03-015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Investigation of the regulation of vascular function by endothelium-derived factors has been a prominent topic of research in the field of hypertension during the last decade. Of the different endothelial factors, endothelins, which play an important role in vasodilatation-vasoconstriction balance, have been the subject of great interest and an impressive number of publications. This peptide, a very potent vasoconstrictor, triggers as well events involved in growth, proliferation, matrix production and local inflammation. In parallel, its role in hypertension has evolved from a simple vasoconstrictor to a central local regulator of vascular homeostasis contributing not only to the elevation of blood pressure, but also to the complications of hypertension. This review summarizes research on endothelins and its receptor antagonists in experimental hypertension, with special emphasis on vascular remodeling and target-organ protection.
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Affiliation(s)
- Pierre Moreau
- Laboratory of Vascular Pharmacology, Faculty of Pharmacy, Université de Montréal, PO Box 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada.
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30
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Brantley JG, Sharma M, Alcalay NI, Heuvel GBV. Cux-1 transgenic mice develop glomerulosclerosis and interstitial fibrosis. Kidney Int 2003; 63:1240-8. [PMID: 12631340 DOI: 10.1046/j.1523-1755.2003.00889.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Cux-1 is a murine homeobox gene that is highly expressed in the nephrogenic zone of the developing kidney. Transgenic mice ectopically expressing Cux-1 develop renal hyperplasia associated with down-regulation of the cyclin kinase inhibitor p27. Because the reduction of p27 has been associated with mesangial cell proliferation and glomerular disease, we evaluated glomerular changes in Cux-1 transgenic mice. METHODS Adult kidneys from Cux-1 transgenic mice were analyzed morphologically for changes in glomerular cell number and for changes in mesangial and interstitial extracellular matrix deposition. Mesangial matrix expansion was identified by light microscopy. Glomerular cell number was performed following immunohistochemistry. Type IV collagen deposition was analyzed by immunofluoresence and Western blotting. Renal function was evaluated by serum protein, blood urea nitrogen (BUN), creatinine, and electrolyte analysis, and by urine protein and creatinine analysis. RESULTS In adult transgenic glomeruli, Cux-1 was ectopically expressed in mesangial cells, and this was associated with an increase in mesangial cell number, resulting from an increase in proliferation. There was a marked increase in mesangial matrix area in transgenic mice compared to non-transgenic littermates, related to an increase in type IV collagen. Podocyte foot process effacement was observed in transgenic mice, and this was related to an increase in urinary albumin. Interstitial fibrosis was also observed in transgenic kidneys. CONCLUSION These observations indicate that increased expression of Cux-1 in mesangial cells results in cell proliferation and mesangial expansion. In addition, these changes are potentially related to disruption of podocyte architecture leading to loss of filtration. These results suggest that expression of Cux-1 is sufficient to induce the early events of mesangioproliferative glomerulonephritis.
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MESH Headings
- Animals
- Cell Division
- Disease Models, Animal
- Female
- Fibrosis
- Glomerulonephritis, Membranoproliferative/genetics
- Glomerulonephritis, Membranoproliferative/pathology
- Glomerulonephritis, Membranoproliferative/physiopathology
- Glomerulosclerosis, Focal Segmental/genetics
- Glomerulosclerosis, Focal Segmental/pathology
- Glomerulosclerosis, Focal Segmental/physiopathology
- Homeodomain Proteins
- Kidney Glomerulus/pathology
- Kidney Glomerulus/physiopathology
- Male
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Transgenic
- Nuclear Proteins/genetics
- Proteinuria/genetics
- Proteinuria/pathology
- Proteinuria/physiopathology
- Repressor Proteins/genetics
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Affiliation(s)
- Jennifer G Brantley
- Department of Anatomy and Cell Biology and University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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31
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Moreau P, Dao HH. An update on the status of endothelin receptor antagonists for hypertension. Expert Opin Investig Drugs 2001; 10:1937-46. [PMID: 11772297 DOI: 10.1517/13543784.10.11.1937] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Endothelin receptor antagonists (ETRA) are actively developed by the pharmaceutical industry for several cardiovascular indications. In the context of hypertension, preclinical studies are increasingly focused on prevention or regression of end-organ damage and drug combination than on control of arterial pressure in monotherapy, as most experimental models have already been studied. In general, the antihypertensive effect of ETRA is limited but the overwhelming efficacy of this class of drugs to prevent several end-organ damages warrants judicious combination. However, the few studies looking at regression of hypertension-induced cardiovascular alterations proved less successful, suggesting that ETRA should be used early in the treatment of hypertension to obtain full benefit. Judging from the progression of ongoing trials and the development of new trials patients suffering from pulmonary hypertension and heart failure may be the first to benefit from this new class of drugs. However, it is expected that once on the market, responsive subsets of hypertensive patients will be identified and will benefit from end-organ protection.
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Affiliation(s)
- P Moreau
- Laboratory of Vascualar Pharmacology, Faculty of Pharmacy, Université de Montréal, P.O. Box 6128, Stn 'Centre-ville,' Montréal, Quebec, H3C 3J7, Canada.
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32
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Spiers JP, Dorman A, Allen JD, Kelso EJ, Silke B, McDermott BJ. Myocardial expression of the endothelin system in endotoxin-treated rats. J Cardiovasc Pharmacol 2001; 38:259-67. [PMID: 11483876 DOI: 10.1097/00005344-200108000-00012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although circulating plasma levels of endothelin (ET)-1 are elevated in endotoxemia, little is known about the myocardial expression of the ET system in endotoxic shock. We assessed the temporal mRNA expression pattern of key components of the ET system (pre-pro ET (ppET) -1, -2, ET-converting enzyme-1, ET(A) and ET(B) receptors) by reverse transcription polymerase chain reaction in a rat model of early endotoxic shock. Lipopolysaccharide (5 mg/kg, i.p.) caused a transient increase (p < 0.05) in inducible nitric oxide synthase mRNA expression. ppET-1 mRNA expression was increased at 2 h (approximately 12-fold increase; p < 0.05) in the lipopolysaccharide compared with the saline group and ppET-2 mRNA expression was unaltered. ET-converting enzyme-1, ET(A), and ET(B) receptor mRNA expression was unaltered in the lipopolysaccharide compared with the saline group. While ppET-1 mRNA expression is selectively upregulated in ventricular myocardium of lipopolysaccharide-treated rats, an absence of alteration in ET-converting enzyme-1 mRNA expression suggests an excess capacity of ET-converting enzyme-1 to cope with the increased expression of ET-1. At the level of the receptor, endotoxic shock did not affect the expression of either ET(A) or ET(B) receptor mRNA. These data are consistent with the increased expression of myocardial ET-1 as an acute-phase response due to hemodynamic instability associated with the early stages of endotoxic shock.
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Affiliation(s)
- J P Spiers
- Department of Physiology, The Queen's University of Belfast, Northern Ireland.
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33
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Schmidt-Ott KM, Xu AD, Tuschick S, Liefeldt L, Kresse W, Verkhratsky A, Kettenmann H, Paul M. Hypoxia reverses dibutyryl-cAMP-induced stellation of cultured astrocytes via activation of the endothelin system. FASEB J 2001; 15:1227-9. [PMID: 11344096 DOI: 10.1096/fj.00-0625fje] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- K M Schmidt-Ott
- Institute of Clinical Pharmacology and Toxicology, Freie Universität Berlin, Benjamin Franklin Medical Center, Berlin, Germany
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34
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Foitzik T, Faulhaber J, Hotz HG, Kirchengast M, Buhr HJ. Endothelin mediates local and systemic disease sequelae in severe experimental pancreatitis. Pancreas 2001; 22:248-54. [PMID: 11291925 DOI: 10.1097/00006676-200104000-00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endothelin-1 has been shown to reduce pancreatic blood flow and cause focal acinar cell necrosis similar to those seen in acute pancreatitis (AP), whereas therapy with endothelin receptor antagonists enhanced pancreatic capillary blood flow (PCBF) and decreased mortality rates. The current study evaluated the role of endothelin in the development of severe AP. Trypsinogen activation peptides, acinar cell necrosis, and PCBF were used as local indicators of disease severity, fluid sequestration, cardiorespiratory and renal parameters, and colonic capillary blood flow as systemic disease indicators. The following groups of animals were examined: 1) rats with mild edematous AP and 2) severe necrotizing AP treated with and without endothelin, 3) transgenic rats overexpressing endothelin with severe AP, and 4) rats with severe AP prophylactically treated with endothelin receptor antagonists. The following observations were made: endothelin superimposed on mild AP caused hemoconcentration, a decrease in PCBF, and necrosis and ascites not seen in this model without endothelin exposure. Endothelin superimposed on severe AP had no significant effects. After induction of severe AP, less PCBF and more acinar cell necrosis were observed in transgenic rats than in their normal littermates. Prophylactic endothelin receptor antagonists improved local (acinar necrosis, PCBF) and systemic parameters (ascites, urine production, colonic capillary blood flow) of disease severity in animals with severe AP. These observations underscore the role of endothelin as a mediator of disease severity in AP and suggest that endothelin receptor blockade may become a promising therapeutic tool in this disease.
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Affiliation(s)
- T Foitzik
- Department of Surgery, Benjamin Franklin Medical Center, Freie Universität Berlin, Germany.
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35
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Abstract
Cardiovascular diseases are a major cause of mortality in our society. The development of a new successful treatment strategy requires a deeper understanding of cardiovascular physiology and pathophysiology. This can be achieved by using classical pharmacological and molecular biological approaches as well as by the investigation of specific animal models. In this context novel transgenic methods can be used to dissect pathophysiological factors influencing the development of cardiovascular disease. Because there is direct and indirect evidence for an important role of the endothelin system in the pathogenesis of cardiovascular diseases, several transgenic models with gain of function or loss of function strategies have been established for selected components of the endothelin system. This paper summarizes existing models and outlines recent developments in the transgenic field of endothelin research.
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Affiliation(s)
- F S Zollmann
- Institute of Clinical Pharmacology and Toxicology, Free University Berlin, Germany
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36
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Benigni A, Perico N, Remuzzi G. Research on renal endothelin in proteinuric nephropathies dictates novel strategies to prevent progression. Curr Opin Nephrol Hypertens 2001; 10:1-6. [PMID: 11195041 DOI: 10.1097/00041552-200101000-00001] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Proteinuria is one of the major risk factors for renal disease progression in patients with chronic nephropathies. Studies in disease models have helped to delineate mechanisms leading to renal structural damage as a result of persistent dysfunction of the glomerular barrier to proteins, even when the primary immune or non-immune insult to the kidney has ceased. From these preclinical studies, a role for endothelin in proteinuric chronic renal diseases has been suggested, thus providing the rationale for novel therapeutic approaches with endothelin receptor antagonists to maximize renoprotection so far achieved with blockade of the renin-angiotensin system by angiotensin-converting enzyme inhibition or angiotensin II receptor antagonism. Trials are needed to explore this potential area of clinical interest.
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Affiliation(s)
- A Benigni
- Mario Negri Institute for Pharmacological Research, Ospedali Riuniti di Bergamo, Italy.
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37
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DUSSAULE JEANCLAUDE, THARAUX PIERRELOUIS, BOFFA JEANJACQUES, FAKHOURI FADI, ARDAILLOU RAYMOND, CHATZIANTONIOU CHRISTOS. Mechanisms Mediating the Renal Profibrotic Actions of Vasoactive Peptides in Transgenic Mice. J Am Soc Nephrol 2000. [DOI: 10.1681/asn.v11suppl_2s124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Abstract. Transgenic mice are useful tools to investigate the mechanisms of the renal profibrotic actions of endothelin and angiotensin II. The overexpression of angiotensinogen and renin genes induces renal sclerosis independently of changes in systemic hemodynamics. The same results are observed when the endothelin-1 gene is overexpressed. Transgenic mice harboring the luciferase gene, under the control of the collagen I α2 chain promoter, and made hypertensive by induction of a nitric oxide (NO) deficiency have been studied. In this strain of mice, luciferase activity is an early index of renal and vascular fibrosis. Luciferase activity was increased in preglomerular arterioles and glomeruli when mice were treated with Nω-nitro-L-arginine methyl ester, an inhibitor of NO synthases. Bosentan (an endothelin receptor antagonist) was as efficient as losartan (an AT1 receptor antagonist) in preventing renal fibrosis, although it did not decrease BP. In short-term experiments, angiotensin II produced an increase in luciferase activity that was entirely prevented by losartan but also by bosentan. It can be concluded that, during chronic inhibition of NO, the collagen I gene is activated, which contributes to the development of nephroangiosclerosis and glomerulosclerosis. Angiotensin II plays a major role in this fibrogenic process, and its effect is at least partly independent of systemic hemodynamics and mediated by the profibrotic action of endothelin-1.
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38
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Abstract
More than 50 million Americans display blood pressures outside the safe physiological range. Unfortunately for most individuals, the molecular basis of hypertension is unknown, in part because pathological elevations of blood pressure are the result of abnormal expression of multiple genes. This review identifies a number of important blood pressure regulatory genes including their loci in the human, mouse, and rat genome. Phenotypes of gene deletions and overexpression in mice are summarized. More detailed discussion of selected gene products follows, beginning with proteins involved in ion transport, specifically the epithelial sodium channel and sodium proton exchangers. Next, proteins involved in vasodilation/natriuresis are discussed with emphasis on natriuretic peptides, guanylin/uroguanylin, and nitric oxide. The renin angiotensin aldosterone system has an important role antagonizing the vasodilatory cyclic GMP system.
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Affiliation(s)
- D L Garbers
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas 75235-9050, USA.
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39
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Hocher B, Paul M. Transgenic animal models for the analysis of the renal endothelin system. Nephrol Dial Transplant 2000; 15:935-7. [PMID: 10862624 DOI: 10.1093/ndt/15.7.935] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- B Hocher
- Department of Nephrology, University Hospital Charité, Humboldt Universität zu Berlin, Germany
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40
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Abstract
The present review focuses on recent data regarding the role of endothelin as a mediator of renal vascular fibrosis. Following a brief description of the endothelin system, the question of whether endothelin is involved in hypertensive mechanisms is examined in experimental, genetic and transgenic animal models. Evidence is provided that implicates endothelin as an important factor of the development of tissue fibrosis and end-organ damage associated with hypertension, with particular emphasis on renal vascular fibrosis. Data indicating that endothelin interacts with other vasoconstrictor systems, such as angiotensin II, are also considered. Finally, results from preliminary clinical studies using endothelin receptor antagonists to treat cardiac and renal pathologies are briefly discussed.
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Affiliation(s)
- C Chatziantoniou
- INSERM U.489, Hòpital Tenon, and AP-HP, Laboratoire de Physiologie, Facultè de Mèdecine St Antoine, Paris, France.
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41
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Morgera S, Kuchinke S, Budde K, Lun A, Hocher B, Neumayer HH. Volume stress-induced peritoneal endothelin-1 release in continuous ambulatory peritoneal dialysis. J Am Soc Nephrol 1999; 10:2585-90. [PMID: 10589698 DOI: 10.1681/asn.v10122585] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
In long-term peritoneal dialysis, functional deterioration of the peritoneal membrane is often associated with proliferative processes of the involved tissues leading to peritoneal fibrosis. In continuous ambulatory peritoneal dialysis (CAPD), failure to achieve target values for adequacy of dialysis is commonly corrected by increasing dwell volume; in case of ultrafiltration failure, osmolarity of the dialysate gets increased. In a prospective study, the impact of increasing dwell volume from 1500 ml to 2500 ml per dwell (volume trial) or changing the osmolarity of the dialysate from 1.36 to 3.86% glucose (hyperosmolarity trial) on the peritoneal endothelin-1 (ET-1) release was analyzed. ET-1 is known to exert significant proliferative activities on a variety of cell types leading to an accumulation of extracellular matrix. A highly significant difference in the cumulative peritoneal ET-1 synthesis was found between the low- and high-volume exchange, whereas differences in the hyperosmolarity setting were only moderate. Sixty minutes after initiating dialysis, the cumulative ET-1 synthesis was 2367 +/- 1023 fmol for the 1500 ml versus 6062 +/- 1419 fmol for the 2500 dwell (P < 0.0001) and 4572 +/- 969 fmol versus 6124 +/- 1473 fmol for the 1.36 and 3.86% glucose dwell (P < 0.05), respectively. In conclusion, increasing dwell volume leads to a strong activation of the peritoneal paracrine endothelin system. Because ET-1, apart from being a potent vasoactive peptide, contributes to fibrotic remodeling, this study indicates that volume stress-induced ET-1 release might contribute to structural alteration of the peritoneal membrane in long-term peritoneal dialysis.
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Affiliation(s)
- S Morgera
- Department of Nephrology, Humboldt University of Berlin, Germany.
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42
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Kakinuma Y, Miyauchi T, Kobayashi T, Yuki K, Maeda S, Sakai S, Goto K, Yamaguchi I. Myocardial expression of endothelin-2 is altered reciprocally to that of endothelin-1 during ischemia of cardiomyocytes in vitro and during heart failure in vivo. Life Sci 1999; 65:1671-83. [PMID: 10573185 DOI: 10.1016/s0024-3205(99)00416-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We and other groups have reported that endothelin (ET)-1 expression in the heart is altered in the setting of heart diseases. We have also reported that myocardial ET-1 is involved in the progression of heart failure, and that an ET receptor antagonist improves long-term survival in heart failure (Nature 384: 353-355, 1996). However, the role of myocardial ET-2 in disease states are not known. To characterize the role of ET-2, we used a) the failing hearts of rats with heart failure caused by myocardial infarction, and b) primary cultured cardiomyocytes subjected to hypoxia. In the failing heart in vivo, ET-1 mRNA increased by 390% compared with that in the non-failing heart, while ET-2 mRNA drastically decreased by 88%. Thus, gene expression of ET-1 and ET-2 was reciprocally altered in the failing heart in vivo. In in vitro studies, reciprocal alterations in ET-1 and ET-2 gene expression were also observed in isolated primary cultured cardiomyocytes, subjected to hypoxia. Specifically, acute hypoxic stress induced a significant increase (360% of the basal level) in ET-2 mRNA expression compared with that in normoxic cells, whereas it decreased ET-1 mRNA expression by 62% in primary cultured cardiomyocytes. Although these two crucial conditions, i.e., heart failure in vivo and acute hypoxic stress in vitro, are pathophysiologically distinct from each other, reciprocal alteration of ET-1 and ET-2 gene expression was observed in both cases. To further investigate the regulatory mechanism of the altered gene expression, luciferase analysis was performed using primary cultured cardiomyocytes. ET-2 promoter, which is the 5'-flanking region of preproET-2 gene (5'ET-2), showed a marked increase in luciferase activity during acute hypoxia. In contrast, the luciferase activity of 5'ET-1 (ET-1 promoter) did not change in response to hypoxic stress. The present study suggests that there are transcriptionally distinct regulatory mechanisms for ET-1 and ET-2 expression in cardiomyocytes, and therefore this study may provide a new aspect of cardiac ET system that not only ET-1 but also ET-2 can be participated in the pathophysiological conditions.
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Affiliation(s)
- Y Kakinuma
- Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
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43
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Sharma P, Hingorani A, Jia H, Hopper R, Brown MJ. Quantitative association between a newly identified molecular variant in the endothelin-2 gene and human essential hypertension. J Hypertens 1999; 17:1281-7. [PMID: 10489105 DOI: 10.1097/00004872-199917090-00007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Essential hypertension is a multifactorial disease in which the genetic contribution is probably the result of a number of genes acting in combination. Recent work has incriminated endothelin-2 (ET2) as a candidate gene for human essential hypertension. This study sought to (i) determine the existence of any molecular variants in the ET2 gene; (ii) undertake an allelic-association study of any such variants found in a large group of well characterized hypertensive and control populations; and (iii) assess any quantitative relationship between the molecular variant and pretreatment blood presure. METHODS The ET2 gene was subjected to single strand conformation polymorphism (SSCP) analysis in order to identify novel molecular variants. Well-characterized subjects recruited from our local population were used in our association study. Two hundred and forty-four hypertensive patients with pre-treatment blood pressure (range 139/94-237/133 mmHg) were well matched with 228 controls from our local population of 30000 healthy subjects (range 96/62-160/85 mmHg). All subjects were Caucasian. RESULTS Polymerase chain reaction-SSCP identified a single A985G base change in 3'-UTR of the ET2 gene which was confirmed by direct sequencing. A restriction site for the enzyme BsmA1 was either created (+) or removed (-) with this polymorphism. Analysis of variance showed that the ET2 genotype was an independent predictor of pre-treatment diastolic blood pressure (DBP) in the hypertensive (P< 0.001) but not normotensive group with higher pressures tracking with the (-) allele. Other covariates such as age, sex, alcohol, cigarette smoking, body mass index and cholesterol showed no significant relationship with this genotype. The genotype frequencies for the hypertensive and control population were (-/-: -/+: +/+) 178 :58:8 and 168:55: 5, respectively (not significant). Subjects from the top and tail quartiles of measurement of blood pressure in both groups were selected for genotype and allele frequency comparison. Both genotype and allele differences were highly significant between the two extreme groups for DBP (genotype P< 0.001, alleles P< 0.01) distribution. A search for potential functional variants in linkage disequilibrium with A985G found one further variant in the 5'-UTR, C44T. Conditional haplotype probabilities in 214 chromosomes show that this polymorphism is not in linkage disequilibrium with the 3'-UTR. No other variants were found on a molecular screen of the transcribed portion of the ET2 gene. CONCLUSION This newly identified polymorphism of the ET2 gene tracked significantly in hypertensives when blood pressure was assessed as a quantitative trait. The difference in genotype and allele frequencies between the extremes of blood pressure suggest that the ET2 locus influences the severity rather than the initial development of hypertension.
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Affiliation(s)
- P Sharma
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital, UK.
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Ruschitzka F, Noll G, Lüscher TF. Angiotensin converting enzyme inhibitors and vascular protection in hypertension. J Cardiovasc Pharmacol 1999; 34 Suppl 1:S3-12. [PMID: 10499558 DOI: 10.1097/00005344-199908001-00002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Strategically located between the circulating blood and the vascular smooth muscle, endothelial cells release numerous vasoactive substances regulating the function of vascular smooth muscle and circulating blood cells. Endothelium-derived vasodilators include prostacyclin, nitric oxide and endothelium-derived hyperpolarizing factor. In particular, nitric oxide inhibits cellular growth and migration. In concert with prostacyclin, nitric oxide exerts potent antiatherogenic and thromboresistant properties by preventing platelet aggregation and cell adhesion. These effects are counterbalanced by vasoconstrictors, such as angiotensin II and endothelin (ET)-1, both of which exert prothrombotic and growth-promoting properties. In hypertension, elevated blood pressure causes vascular disease by inducing endothelial dysfunction. Hence, modern therapeutic strategies in human hypertension focus on preserving or restoring endothelial integrity. Beyond inhibiting the renin-angiotensin system, angiotensin-converting enzyme (ACE) inhibitors diminish the inactivation of bradykinin, thus leading to an augmentation of nitric oxide release. In addition, the compounds stabilize the B2-receptor, and reduce oxidative stress and tissue ET-1 levels. In patients with coronary artery disease, chronic ACE inhibition improves endothelial function. Further clinical studies are already under way which will prove whether these beneficial vascular effects of ACE inhibitors on endothelial dysfunction result in a clinical benefit for patients with hypertension.
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Affiliation(s)
- F Ruschitzka
- Department of Cardiology, University Hospital Zürich, Switzerland
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Abstract
The endothelins are 21-amino-acid peptides which may play a role in the pathogenesis of hypertension. There is increasing evidence that the endothelins have a central function in mediating end-organ damage in hypertension, and that important effects of endothelin in the pathogenesis of hypertension may be based on the interactions of the endothelins and the renin-angiotensin and the nitric oxide systems.
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Affiliation(s)
- L Rothermund
- Department of Clinical Pharmacology and Toxicology, Freie Universität Berlin, Germany
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Hocher B, Zart R, Braun N, Schwarz A, van der Woude F, Rohmeiss P, Koppenhagen K. The Endothelin system in polycystic kidneys of Han:SPRD rats. J Cardiovasc Pharmacol 1998; 31 Suppl 1:S342-4. [PMID: 9595476 DOI: 10.1097/00005344-199800001-00095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Polycystic kidney disease (PKD) is characterized by structural alterations such as thickening of the tubule basement membrane, interstitial fibrosis, and formation of cysts. Han:SPRD rats are a well-known rat model of human PKD. Interestingly, interstitial fibrosis, glomerulosclerosis, and cyst formation were also seen in human endothelin-1 (ET-1) transgenic mice. We therefore analyzed the tissue concentrations of ET-1 and the expression of ET receptor subtypes in the kidneys of young homozygous (cy/cy), heterozygous (cy/+) 6 week-old male Han:SPRD, and corresponding control rats. The kidneys of affected rats showed significantly elevated tissue levels of ET-1 compared to age-matched controls. Scatchard analysis, on the other hand, revealed markedly decreased ETA and ETB receptor density in all groups of affected rats. The binding affinity of both ET receptor subtypes was slightly decreased in Han:SPRD rats. These data show that the renal paracrine ET system is activated in PKD and might contribute to renal cyst formation and development of end-stage kidney disease.
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Affiliation(s)
- B Hocher
- Department of Nephrology, Humboldt University of Berlin, Germany
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Hocher B, Rohmeiss P, Thöne-Reineke C, Schwarz A, Burst V, van der Woude F, Bauer C, Theuring F. Apoptosis in kidneys of endothelin-1 transgenic mice. J Cardiovasc Pharmacol 1998; 31 Suppl 1:S554-6. [PMID: 9595541 DOI: 10.1097/00005344-199800001-00160] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endothelin-1 (ET-1) transgenic mice are characterized by age-dependent development of renal cysts and renal fibrosis (interstitial fibrosis and glomerulosclerosis), leading to a progressive decrease in glomerular filtration rate. The mechanism causing the loss of functionally and morphologically normal renal tissue is unknown. An imbalance between cell proliferation and apoptosis in the kidneys of ET-1 transgenic mice might contribute to this process. We identified apoptotic cells in kidney sections by in situ end-labeling and by the typical nuclear chromatin morphology after propidium iodide (PI) staining. Cell proliferation was measured by estimating the proliferating cell nuclear antigen (PCNA)-positive cells. The numbers of apoptotic cells were significantly increased (p < 0.001) in the kidneys of 14-month-old ET-1 transgenic mice, whereas cell proliferation was not enhanced. Apoptotic cells were detected in the glomeruli, tubular cells, and renal interstitial cells in ET-1 transgenic mice. In conclusion, apoptotic loss of functional renal tissue appears to be associated with the progression of cyst formation and renal fibrosis. Therefore, an imbalance between cell proliferation and apoptosis could be an important cellular mechanism in ET-1 transgenic mice leading to end-stage kidney disease.
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Affiliation(s)
- B Hocher
- Department of Nephrology, Charité, Humboldt University of Berlin, Germany
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Hocher B, Lun A, Priem F, Neumayer HH, Raschack M. Renal endothelin system in diabetes: comparison of angiotensin-converting enzyme inhibition and endothelin-A antagonism. J Cardiovasc Pharmacol 1998; 31 Suppl 1:S492-5. [PMID: 9595522 DOI: 10.1097/00005344-199800001-00141] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An activated renal endothelin (ET) system is implicated in the pathogenesis of renal fibrosis, as recently shown in ET-1 transgenic mice. Because progressive renal fibrosis is also a major finding in diabetic nephropathy, we analyzed the activity of the renal ET system in rats with streptozotocin-induced diabetes mellitus and the effect of blocking the ETA receptor, using the orally active ETA antagonist LU 135252. The effects of long-term treatment with LU 135252 were compared with those of an ACE inhibitor. Plasma and urinary ET-1 concentrations were measured. Progression of diabetic nephropathy was analyzed by measuring urinary albumin and protein excretion. Urinary ET-1 excretion was significantly elevated as early as 7 days after induction of diabetes and increased further. The daily urine volume was significantly correlated with urine ET-1 excretion. Treatment with LU 135252 significantly decreased the ET-1 excretion by more than 50%, whereas ACE inhibition resulted only in a mild decrease. Albumin excretion was significantly decreased after ACE inhibition, whereas ETA inhibition resulted in a nonsignificant decrease. Urinary ET and albumin excretion probably reflect independent mechanisms of renal damage in diabetes.
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Affiliation(s)
- B Hocher
- Department of Nephrology, University Charité Clinic, Humboldt University, Berlin, Germany
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Schiffrin EL, Intengan HD, Thibault G, Touyz RM. Clinical significance of endothelin in cardiovascular disease. Curr Opin Cardiol 1997. [DOI: 10.1097/00001573-199707000-00003] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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