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Schiffrin EL, Pollock DM. Endothelin System in Hypertension and Chronic Kidney Disease. Hypertension 2024; 81:691-701. [PMID: 38059359 PMCID: PMC10954415 DOI: 10.1161/hypertensionaha.123.21716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
ET (endothelin) is a powerful vasoconstrictor 21-amino acid peptide present in many tissues, which exerts many physiological functions across the body and participates as a mediator in many pathological conditions. ETs exert their effects through ETA and ETB receptors, which can be blocked by selective receptor antagonists. ETs were shown to play important roles among others, in systemic hypertension, particularly when resistant or difficult to control, and in pulmonary hypertension, atherosclerosis, cardiac hypertrophy, subarachnoid hemorrhage, chronic kidney disease, diabetic cardiovascular disease, scleroderma, some cancers, etc. To date, ET antagonists are only approved for the treatment of primary pulmonary hypertension and recently for IgA nephropathy and used in the treatment of digital ulcers in scleroderma. However, they may soon be approved for the treatment of patients with resistant hypertension and different types of nephropathy. Here, the role of ETs is reviewed with a special emphasis on participation in and treatment of hypertension and chronic kidney disease.
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Affiliation(s)
- Ernesto L. Schiffrin
- Lady Davis Institute for Medical Research, and Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University
| | - David M. Pollock
- Section of Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL
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Martínez-Díaz I, Martos N, Llorens-Cebrià C, Álvarez FJ, Bedard PW, Vergara A, Jacobs-Cachá C, Soler MJ. Endothelin Receptor Antagonists in Kidney Disease. Int J Mol Sci 2023; 24:ijms24043427. [PMID: 36834836 PMCID: PMC9965540 DOI: 10.3390/ijms24043427] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/25/2023] [Accepted: 01/28/2023] [Indexed: 02/11/2023] Open
Abstract
Endothelin (ET) is found to be increased in kidney disease secondary to hyperglycaemia, hypertension, acidosis, and the presence of insulin or proinflammatory cytokines. In this context, ET, via the endothelin receptor type A (ETA) activation, causes sustained vasoconstriction of the afferent arterioles that produces deleterious effects such as hyperfiltration, podocyte damage, proteinuria and, eventually, GFR decline. Therefore, endothelin receptor antagonists (ERAs) have been proposed as a therapeutic strategy to reduce proteinuria and slow the progression of kidney disease. Preclinical and clinical evidence has revealed that the administration of ERAs reduces kidney fibrosis, inflammation and proteinuria. Currently, the efficacy of many ERAs to treat kidney disease is being tested in randomized controlled trials; however, some of these, such as avosentan and atrasentan, were not commercialized due to the adverse events related to their use. Therefore, to take advantage of the protective properties of the ERAs, the use of ETA receptor-specific antagonists and/or combining them with sodium-glucose cotransporter 2 inhibitors (SGLT2i) has been proposed to prevent oedemas, the main ERAs-related deleterious effect. The use of a dual angiotensin-II type 1/endothelin receptor blocker (sparsentan) is also being evaluated to treat kidney disease. Here, we reviewed the main ERAs developed and the preclinical and clinical evidence of their kidney-protective effects. Additionally, we provided an overview of new strategies that have been proposed to integrate ERAs in kidney disease treatment.
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Affiliation(s)
- Irene Martínez-Díaz
- Nephrology and Transplantation Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Nerea Martos
- Nephrology and Transplantation Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Carmen Llorens-Cebrià
- Nephrology and Transplantation Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | | | | | - Ander Vergara
- Nephrology and Transplantation Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- Correspondence: (A.V.); (C.J.-C.)
| | - Conxita Jacobs-Cachá
- Nephrology and Transplantation Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- Correspondence: (A.V.); (C.J.-C.)
| | - Maria José Soler
- Nephrology and Transplantation Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
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de Oliveira AA, Nunes KP. Hypertension and Erectile Dysfunction: Breaking Down the Challenges. Am J Hypertens 2021; 34:134-142. [PMID: 32866225 DOI: 10.1093/ajh/hpaa143] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/15/2020] [Accepted: 08/29/2020] [Indexed: 02/07/2023] Open
Abstract
A diagnostic of hypertension increases the risk of erectile dysfunction (ED); likewise, ED can be an early sign of hypertension. In both cases, there is evidence that endothelial dysfunction is a common link between the 2 conditions. During hypertension, the sustained and widespread release of procontractile factors (e.g., angiotensin II, endothelin 1, and aldosterone) impairs the balance between vasoconstrictors and vasodilators and, in turn, detrimentally impacts vascular and erectile structures. This prohypertensive state associates with an enhancement in the generation of reactive oxygen species, which is not compensated by internal antioxidant mechanisms. Recently, the innate immune system, mainly via Toll-like receptor 4, has also been shown to actively contribute to the pathophysiology of hypertension and ED not only by inducing oxidative stress but also by sustaining a low-grade inflammatory state. Furthermore, some drugs used to treat hypertension can cause ED and, consequently, reduce compliance with the prescribed pharmacotherapy. To break down these challenges, in this review, we focus on discussing the well-established as well as the emerging mechanisms linking hypertension and ED with an emphasis on the signaling network of the vasculature and corpora cavernosa, the vascular-like structure of the penis.
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Affiliation(s)
- Amanda Almeida de Oliveira
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, Florida, USA
| | - Kenia Pedrosa Nunes
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, Florida, USA
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Czopek A, Moorhouse R, Guyonnet L, Farrah T, Lenoir O, Owen E, van Bragt J, Costello HM, Menolascina F, Baudrie V, Webb DJ, Kluth DC, Bailey MA, Tharaux PL, Dhaun N. A novel role for myeloid endothelin-B receptors in hypertension. Eur Heart J 2020; 40:768-784. [PMID: 30657897 PMCID: PMC6396028 DOI: 10.1093/eurheartj/ehy881] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 09/04/2018] [Accepted: 12/10/2018] [Indexed: 12/11/2022] Open
Abstract
AIMS Hypertension is common. Recent data suggest that macrophages (Mφ) contribute to, and protect from, hypertension. Endothelin-1 (ET-1) is the most potent endogenous vasoconstrictor with additional pro-inflammatory properties. We investigated the role of the ET system in experimental and clinical hypertension by modifying Mφ number and phenotype. METHODS AND RESULTS In vitro, Mφ ET receptor function was explored using pharmacological, gene silencing, and knockout approaches. Using the CD11b-DTR mouse and novel mice with myeloid cell-specific endothelin-B (ETB) receptor deficiency (LysMETB-/-), we explored the effects of modifying Mφ number and phenotype on the hypertensive effects of ET-1, angiotensin II (ANG II), a model that is ET-1 dependent, and salt. In patients with small vessel vasculitis, the impacts of Mφ depleting and non-depleting therapies on blood pressure (BP) and endothelial function were examined. Mouse and human Mφ expressed both endothelin-A and ETB receptors and displayed chemokinesis to ET-1. However, stimulation of Mφ with exogenous ET-1 did not polarize Mφ phenotype. Interestingly, both mouse and human Mφ cleared ET-1 through ETB receptor mediated, and dynamin-dependent, endocytosis. Mφ depletion resulted in an augmented chronic hypertensive response to both ET-1 and salt. LysMETB-/- mice displayed an exaggerated hypertensive response to both ET-1 and ANG II. Finally, in patients who received Mφ depleting immunotherapy BP was higher and endothelial function worse than in those receiving non-depleting therapies. CONCLUSION Mφ and ET-1 may play an important role in BP control and potentially have a critical role as a therapeutic target in hypertension.
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Affiliation(s)
- Alicja Czopek
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Rebecca Moorhouse
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Léa Guyonnet
- Paris Cardiovascular Research Centre - PARCC, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
| | - Tariq Farrah
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Olivia Lenoir
- Paris Cardiovascular Research Centre - PARCC, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
| | - Elizabeth Owen
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Job van Bragt
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Hannah M Costello
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Filippo Menolascina
- School of Engineering & SynthSys, Institute for Bioengineering, Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, UK.,MRC Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Véronique Baudrie
- Paris Cardiovascular Research Centre - PARCC, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
| | - David J Webb
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - David C Kluth
- MRC Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Matthew A Bailey
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK
| | - Pierre-Louis Tharaux
- Paris Cardiovascular Research Centre - PARCC, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France.,Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Neeraj Dhaun
- BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK.,Paris Cardiovascular Research Centre - PARCC, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
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Schiffrin EL. How Structure, Mechanics, and Function of the Vasculature Contribute to Blood Pressure Elevation in Hypertension. Can J Cardiol 2020; 36:648-658. [PMID: 32389338 DOI: 10.1016/j.cjca.2020.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/02/2020] [Accepted: 02/03/2020] [Indexed: 01/11/2023] Open
Abstract
Large conduit arteries and the microcirculation participate in the mechanisms of elevation of blood pressure (BP). Large vessels play roles predominantly in older subjects, with stiffening progressing after middle age leading to increases in systolic BP found in most humans with aging. Systolic BP elevation and increased pulsatility penetrate deeper into the distal vasculature, leading to microcirculatory injury, remodelling, and associated endothelial dysfunction. The result is target organ damage in the heart, brain, and kidney. In younger individuals genetically predisposed to high BP, increased salt intake or other exogenous or endogenous risk factors for hypertension, including overweight and excess alcohol intake, lead to enhanced sympathetic activity and vasoconstriction. Enhanced vasoconstrictor responses and myogenic tone become persistent when embedded in an increased extracellular matrix, resulting in remodelling of resistance arteries with a narrowed lumen and increased media-lumen ratio. Stimulation of the renin-angiotensin-aldosterone and endothelin systems and inflammatory and immune activation, to which gut microbiome dysbiosis may contribute as a result of salt intake, also participate in the injury and remodelling of the microcirculation and endothelial dysfunction. Inflammation of perivascular fat and loss of anticontractile factors play roles as well in microvessel remodelling. Exaggerated myogenic tone leads to closure of terminal arterioles, collapse of capillaries and venules, functional rarefaction, and eventually to anatomic rarefaction, compromising tissue perfusion. The remodelling of the microcirculation raises resistance to flow, and accordingly raises BP in a feedback process that over years results in stiffening of conduit arteries and systo-diastolic or predominantly systolic hypertension and, more rarely, predominantly diastolic hypertension. Thus, at different stages of life and the evolution of hypertension, large vessels and the microcirculation interact to contribute to BP elevation.
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Affiliation(s)
- Ernesto L Schiffrin
- Lady Davis Institute for Medical Research and Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montréal, Québec, Canada.
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Culshaw GJ, MacIntyre IM, Dhaun N, Webb DJ. Endothelin in nondiabetic chronic kidney disease: preclinical and clinical studies. Semin Nephrol 2016; 35:176-87. [PMID: 25966349 DOI: 10.1016/j.semnephrol.2015.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The incidence and prevalence of chronic kidney disease (CKD) is increasing. Despite current therapies, many patients with CKD have suboptimal blood pressure, ongoing proteinuria, and develop progressive renal dysfunction. Further therapeutic options therefore are required. Over the past 20 years the endothelin (ET) system has become a prime target. Experimental models have shown that ET-1, acting primarily via the endothelin-A receptor, plays an important role in the development of proteinuria, glomerular injury, fibrosis, and inflammation. Subsequent animal and early clinical studies using ET-receptor antagonists have suggested that theses therapies may slow renal disease progression primarily through blood pressure and proteinuria reduction. This review examines the current literature regarding the ET system in nondiabetic CKD.
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Affiliation(s)
- Geoff J Culshaw
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
| | - Iain M MacIntyre
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - Neeraj Dhaun
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - David J Webb
- University/British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
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Abstract
The steroid hormone aldosterone regulates sodium and potassium homeostasis. Aldosterone and activation of the mineralocorticoid receptor also causes inflammation and fibrosis of the heart, fibrosis and remodelling of blood vessels and tubulointerstitial fibrosis and glomerular injury in the kidney. Aldosterone and mineralocorticoid-receptor activation initiate an inflammatory response by increasing the generation of reactive oxygen species by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondria. High salt intake potentiates these effects, in part by activating the Rho family member Rac1, a regulatory subunit of reduced NADPH oxidase that activates the mineralocorticoid receptor. Studies in mice in which the mineralocorticoid receptor has been deleted from specific cell types suggest a key role for macrophages in promoting inflammation and fibrosis. Aldosterone can exert mineralocorticoid-receptor-independent effects via the angiotensin II receptor and via G-protein-coupled receptor 30. Mineralocorticoid-receptor antagonists are associated with decreased mortality in patients with heart disease and show promise in patients with kidney injury, but can elevate serum potassium concentration. Studies in rodents genetically deficient in aldosterone synthase or treated with a pharmacological aldosterone-synthase inhibitor are providing insight into the relative contribution of aldosterone compared with the contribution of mineralocorticoid-receptor activation in inflammation, fibrosis, and injury. Aldosterone-synthase inhibitors are under development in humans.
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Schmid-Schönbein GW. An emerging role of degrading proteinases in hypertension and the metabolic syndrome: autodigestion and receptor cleavage. Curr Hypertens Rep 2012; 14:88-96. [PMID: 22081429 DOI: 10.1007/s11906-011-0240-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
One of the major challenges for hypertension research is to identify the mechanisms that cause the comorbidities encountered in many hypertensive patients, as seen in the metabolic syndrome. An emerging body of evidence suggests that human and experimental hypertensives may exhibit uncontrolled activity of proteinases, including the family of matrix metalloproteinases, recognized for their ability to restructure the extracellular matrix proteins and to play a role in hypertrophy. We propose a new hypothesis that provides a molecular framework for the comorbidities of hypertension, diabetes, capillary rarefaction, immune suppression, and other cell and organ dysfunctions due to early and uncontrolled extracellular receptor cleavage by active proteinases. The proteinase and signaling activity in hypertensives requires further detailed analysis of the proteinase expression, the mechanisms causing proenzyme activation, and identification of the proteinase substrate. This work may open the opportunity for reassessment of old interventions and development of new interventions to manage hypertension and its comorbidities.
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Affiliation(s)
- Geert W Schmid-Schönbein
- Department of Bioengineering, Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA 92093-0412, USA.
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Horowitz JC, Ajayi IO, Kulasekaran P, Rogers DS, White JB, Townsend SK, White ES, Nho RS, Higgins PDR, Huang SK, Sisson TH. Survivin expression induced by endothelin-1 promotes myofibroblast resistance to apoptosis. Int J Biochem Cell Biol 2011; 44:158-69. [PMID: 22041029 DOI: 10.1016/j.biocel.2011.10.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 10/12/2011] [Accepted: 10/18/2011] [Indexed: 12/22/2022]
Abstract
Fibrosis of the lungs and other organs is characterized by the accumulation of myofibroblasts, effectors of wound-repair that are responsible for the deposition and organization of new extracellular matrix (ECM) in response to tissue injury. During the resolution phase of normal wound repair, myofibroblast apoptosis limits the continued deposition of ECM. Mounting evidence suggests that myofibroblasts from fibrotic wounds acquire resistance to apoptosis, but the mechanisms regulating this resistance have not been fully elucidated. Endothelin-1 (ET-1), a soluble peptide strongly associated with fibrogenesis, decreases myofibroblast susceptibility to apoptosis through activation of phosphatidylinositol 3'-OH kinase (PI3K)/AKT. Focal adhesion kinase (FAK) also promotes myofibroblast resistance to apoptosis through PI3K/AKT-dependent and -independent mechanisms, although the role of FAK in ET-1 mediated resistance to apoptosis has not been explored. The goal of this study was to investigate whether FAK contributes to ET-1 mediated myofibroblast resistance to apoptosis and to examine potential mechanisms downstream of FAK and PI3K/AKT by which ET-1 regulates myofibroblast survival. Here, we show that ET-1 regulates myofibroblast survival by Rho/ROCK-dependent activation of FAK. The anti-apoptotic actions of FAK are, in turn, dependent on activation of PI3K/AKT and the subsequent increased expression of Survivin, a member of the inhibitor of apoptosis protein (IAP) family. Collectively, these studies define a novel mechanism by which ET-1 promotes myofibroblast resistance to apoptosis through upregulation of Survivin.
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Affiliation(s)
- Jeffrey C Horowitz
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, United States.
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Delano FA, Chen AY, Wu KIS, Tran ED, Rodrigues SF, Schmid-Schönbein GW. THE AUTODIGESTION HYPOTHESIS AND RECEPTOR CLEAVAGE IN DIABETES AND HYPERTENSION. ACTA ACUST UNITED AC 2011; 8:37-46. [PMID: 22081770 DOI: 10.1016/j.ddmod.2011.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
One of the key features of cardiovascular complications, such as hypertension or diabetes, is that they often appear at the same time in the same individual together with other forms of co-morbidities. While clinically a recognized phenomenon, no molecular mechanism for such co-morbidities has received universal acceptance. We propose a new hypothesis that provides a molecular basis for co-morbidities in hypertension due to unchecked proteolytic activity and receptor destruction. Testing of the hypothesis in the spontaneously hypertensive rat reveals an unchecked matrix metalloproteinase and serine protease activity in plasma and on several cardiovascular and parenchymal cells. The elevated proteolytic activity causes extracellular cleavage of multiple receptor types, such that cleavage of one receptor type leads to loss of the function carried out by this receptor. Proteolytic cleavage of the extracellular domain of the β(2) adrenergic receptor in arteries and arterioles causes vasoconstriction and elevation of the central blood pressure while cleavage of the extracellular domain of the insulin receptor leads to insulin resistance and lack of transmembrane glucose transport. A diverse set of cell dysfunctions in the spontaneously hypertensive rat are accompanied by cleavage of the membrane receptors that are involved in these functions. Chronic inhibition of the unchecked protease activity in the spontaneously hypertensive rat serves to restore the extracellular receptor density and alleviates the corresponding cell dysfunctions. The mild unchecked proteolytic activity in the spontaneously hypertensive rat points towards a chronic autodigestion process as a contributor to the end organ injury encountered in this rat strain. The presence of various soluble receptors, which consist of extracellular fragments of membrane receptors, in the plasma of hypertensive and diabetic patients suggest that the autodigestion process may also be present in man.
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Affiliation(s)
- F A Delano
- Department of Bioengineering, Institute for Engineering in Medicine, University of California San Diego, La Jolla, CA 92093 - 0412
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Stauffer BL, Westby CM, Greiner JJ, Van Guilder GP, Desouza CA. Sex differences in endothelin-1-mediated vasoconstrictor tone in middle-aged and older adults. Am J Physiol Regul Integr Comp Physiol 2009; 298:R261-5. [PMID: 19939973 DOI: 10.1152/ajpregu.00626.2009] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The prevalence of cardiovascular disease is lower in middle-aged and older women than men. Increased endothelin-1-mediated vasoconstriction has been linked to the etiology of a number of cardiovascular diseases, including atherosclerosis, heart failure, and hypertension. It is unknown whether a sex difference in endothelin-1-mediated vasoconstrictor tone exists in middle-aged and older adults. Therefore, we tested the hypothesis that middle-aged and older men would demonstrate greater ET-1-mediated vasoconstrictor tone than age-matched women. Forearm blood flow in response to intra-arterial infusions of endothelin (ET)-1, BQ-123 (a selective ET(A) receptor antagonist), and BQ-788 (a selective ET(B) receptor antagonist) was assessed by venous occlusion plethysmography in 21 women (age: 58 + or - 1 yr; body mass index: 26.0 + or - 1.0 kg/m(2)) and 25 men (age: 57 + or - 2 yr; body mass index: 26.8 + or - 0.7 kg/m(2)). In response to BQ-123, the increase in forearm blood flow from baseline was significantly higher in the men than the women (24 + or - 5% vs. 9 + or - 5%; P < 0.05). In contrast, the increase in forearm blood flow in response to BQ-123 coinfused with BQ-788 was greater in the women than the men, such that the maximum vasodilation to dual endothelin receptor blockade was similar between men and women (approximately 25%). There was no difference in the vasoconstrictor response to ET-1 between the sexes. These results indicate that middle-aged and older men are under greater ET(A) receptor-mediated vasoconstrictor tone than age-matched women. Since the ET(A) receptor is the predominant receptor subtype in the coronary vasculature, this sex difference in vasoconstrictor tone may be a mechanism contributing to the sex difference in the prevalence of coronary heart disease in middle-aged and older adults.
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Affiliation(s)
- Brian L Stauffer
- Integrative Vascular Biology Laboratory, Dept. of Integrative Physiology, Univ. of Colorado, 354 UCB, Boulder, CO 80309, USA.
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13
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Endothelin-1 mediated regulation of extracellular matrix collagens in cells of human lamina cribrosa. Exp Eye Res 2008; 86:886-94. [PMID: 18420197 DOI: 10.1016/j.exer.2008.03.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 01/11/2008] [Accepted: 03/05/2008] [Indexed: 11/21/2022]
Abstract
Endothelin-1 (ET-1), a potent vaso-active peptide, mediates extracellular matrix regulation resulting in an increase in collagen deposition in various cell types and tissues and has been proposed to play a key role in glaucoma pathology. The role of ET-1 in the regulation of extracellular matrix collagens at the level of optic nerve head is not known. In this study we have examined the role of ET-1 in extracellular matrix collagen regulation in primary cultures of human lamina cribrosa cells. Our hypothesis is that ET-1 increases remodeling of the ECM of cells of the lamina cribrosa. Such actions could contribute to the development of optic neuropathy. QPCR analysis revealed that ET-1 mediated an increase in mRNA levels of collagen type I alpha1 and collagen type VI alpha1 chains at all doses of ET-1 with a significant increase at 1nM and 10nM concentration in LC cells. A dose-dependent increase in collagen type I and type VI protein deposition and secretion was also observed by Western blot in response to ET-1 and was significant at 10nM and 100nM concentrations of ET-1. ET-1 increased the [3H] proline uptake in LC cells suggesting that ET-1 contributed to an increase in total collagen synthesis in LC cells. ET-1-mediated increase in collagen type I, type VI and total collagen synthesis was significantly blocked by the ET(A) receptor antagonist, BQ610, as well as with the ET(B) receptor antagonist, BQ788, suggesting the involvement of both receptor subtypes in ET-1 mediated collagen synthesis in LC cells. These results suggest that ET-1 regulates extracellular matrix collagen synthesis in LC cells and may contribute to ECM remodeling at the level of LC of POAG subjects who have elevated plasma and aqueous humor levels of endothelin-1.
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Abstract
The ETs (endothelins) comprise a family of three 21-amino-acid peptides (ET-1, ET-2 and ET-3) and 31-amino-acid ETs (ET-1(1-31), ET-2(1-31) and ET-3(1-31)). ET-1 is synthesized from a biologically inactive precursor, big ET-1, by ECEs (ET-converting enzymes). The actions of ET-1 are mediated through activation of the G-protein-coupled ET(A) and ET(B) receptors, which are found in a variety of cells in the cardiovascular and renal systems. ET-1 has potent vasoconstrictor, mitogenic, pro-inflammatory and antinatriuretic properties, which have been implicated in the pathophysiology of a number of cardiovascular diseases. Overexpression of ET-1 has been consistently described in salt-sensitive models of hypertension and in models of renal failure, and has been associated with disease progression. Sex differences are observed in many aspects of mammalian cardiovascular function and pathology. Hypertension, as well as other cardiovascular diseases, is more common in men than in women of similar age. In experimental models of hypertension, males develop an earlier and more severe form of hypertension than do females. Although the reasons for these differences are not well established, the effects of gonadal hormones on arterial, neural and renal mechanisms that control blood pressure are considered contributing factors. Sex differences in the ET-1 pathway, with males displaying higher ET-1 levels, greater ET-1-mediated vasoconstrictor and enhanced pressor responses in comparison with females, are addressed in the present review. Sex-associated differences in the number and function of ET(B) receptors appear to be particularly important in the specific characteristics of hypertension between females and males. Although the gonadal hormones modulate some of the differences in the ET pathway in the cardiovascular system, a better understanding of the exact mechanisms involved in sex-related differences in this peptidergic system is needed. With further insights into these differences, we may learn that men and women could require different antihypertensive regimens.
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Carey RM. Pathophysiology of Primary Hypertension. Microcirculation 2008. [DOI: 10.1016/b978-0-12-374530-9.00020-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Abstract
Aldosterone concentrations are inappropriately high in many patients with hypertension, as well as in an increasing number of individuals with metabolic syndrome and sleep apnoea. A growing body of evidence suggests that aldosterone and/or activation of the MR (mineralocorticoid receptor) contributes to cardiovascular remodelling and renal injury in these conditions. In addition to causing sodium retention and increased blood pressure, MR activation induces oxidative stress, endothelial dysfunction, inflammation and subsequent fibrosis. The MR may be activated by aldosterone and cortisol or via transactivation by the AT(1) (angiotenin II type 1) receptor through a mechanism involving the EGFR (epidermal growth factor receptor) and MAPK (mitogen-activated protein kinase) pathway. In addition, aldosterone can generate rapid non-genomic effects in the heart and vasculature. MR antagonism reduces mortality in patients with CHF (congestive heart failure) and following myocardial infarction. MR antagonism improves endothelial function in patients with CHF, reduces circulating biomarkers of cardiac fibrosis in CHF or following myocardial infarction, reduces blood pressure in resistant hypertension and decreases albuminuria in hypertensive and diabetic patients. In contrast, whereas adrenalectomy improves glucose homoeostasis in hyperaldosteronism, MR antagonism may worsen glucose homoeostasis and impairs endothelial function in diabetes, suggesting a possible detrimental effect of aldosterone via non-genomic pathways.
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Affiliation(s)
- Annis M Marney
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232-6602, USA
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17
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Callera G, Tostes R, Savoia C, Muscara MN, Touyz RM. Vasoactive peptides in cardiovascular (patho)physiology. Expert Rev Cardiovasc Ther 2007; 5:531-52. [PMID: 17489676 DOI: 10.1586/14779072.5.3.531] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Numerous vasoactive agents play an important physiological role in regulating vascular tone, reactivity and structure. In pathological conditions, alterations in the regulation of vasoactive peptides result in endothelial dysfunction, vascular remodeling and vascular inflammation, which are important processes underlying vascular damage in cardiovascular disease. Among the many vasoactive agents implicated in vascular (patho)biology, angiotensin II (Ang II), endothelin (ET), serotonin and natriuretic peptides appear to be particularly important because of their many pleiotropic actions and because they have been identified as potential therapeutic targets in cardiovascular disease. Ang II, ET-1, serotonin and natriuretic peptides mediate effects via specific receptors, which belong to the group of G-protein-coupled receptors. ET, serotonin and Ang II are primarily vasoconstrictors with growth-promoting actions, whereas natriuretic peptides, specifically atrial, brain and C-type natriuretic peptides, are vasodilators with natriuretic effects. Inhibition of vasoconstrictor actions with drugs that block peptide receptors, compounds that inhibit enzymes that generate vasoactive peptides or agents that increase levels of natriuretic peptides are potentially valuable therapeutic tools in the management of cardiovascular diseases. This review focuses on ET, natriuretic peptides and serotonin. The properties and distribution of these vasoactive agents and their receptors, mechanisms of action and implications in cardiovascular (patho)physiology will be discussed.
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Affiliation(s)
- Glaucia Callera
- University of Ottawa/Ottawa Health Research Institute, Kidney Research Centre, Ottawa, ON, Canada
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18
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Saka M, Obata K, Ichihara S, Cheng XW, Kimata H, Nishizawa T, Noda A, Izawa H, Nagata K, Murohara T, Yokota M. Pitavastatin improves cardiac function and survival in association with suppression of the myocardial endothelin system in a rat model of hypertensive heart failure. J Cardiovasc Pharmacol 2006; 47:770-9. [PMID: 16810078 DOI: 10.1097/01.fjc.0000211791.22411.0d] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Statin therapy may be associated with lower mortality in patients with heart failure, but the underlying mechanism of such an association is unknown. We have evaluated the effects of pitavastatin on cardiac function and survival in a rat model of hypertensive heart failure and investigated the molecular mechanism of the observed effects. Dahl salt-sensitive rats fed with high-salt diet from 7 weeks of age developed compensatory left ventricular hypertrophy at 12 weeks and heart failure at 19 weeks. Dahl salt-sensitive rats were treated with either vehicle or pitavastatin (0.3 mg/kg per day) from 7 or 12 weeks. Both early-onset and late-onset pitavastatin treatment reduced left ventricular fibrosis, improved cardiac function, and increased the survival rate apparent at 19 weeks. The increases in the expression levels of hypertrophic, profibrotic, and metalloproteinase genes as well as in gelatinase activities in the heart induced by the high-salt diet were suppressed by pitavastatin treatment. Furthermore, the level of cardiac endothelin-1 was increased in association with the development of heart failure in a manner sensitive to treatment with pitavastatin. Both early and late pitavastatin treatment thus improved cardiac function and survival, with modulation of extracellular matrix remodeling and endothelin-1 signaling possibly contributing to these beneficial effects.
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Affiliation(s)
- Masako Saka
- Department of Cardiovascular Genome Science, Nagoya University School of Medicine, Japan
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19
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Chade AR, Krier JD, Textor SC, Lerman A, Lerman LO. Endothelin-a receptor blockade improves renal microvascular architecture and function in experimental hypercholesterolemia. J Am Soc Nephrol 2006; 17:3394-403. [PMID: 17082239 DOI: 10.1681/asn.2006060635] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hypercholesterolemia (HC) may trigger early renal injury, partly by impairing the function or the structure of renal microvessels (MV). The endothelin (ET) system is upregulated in HC and can have an impact on the renal microcirculation by regulating MV tone, growth factors, and remodeling. It was hypothesized that ET-A blockade would protect the HC kidney by improving the function and attenuating the damage of intrarenal MV. Single-kidney function and hemodynamic responses to endothelium-dependent challenge were assessed in pigs after 12 wk of experimental HC, HC and chronic supplementation with the ET receptor A blocker ABT-627 (HC+ET-A, 0.75 mg/kg per d), and normal controls. Renal MV architecture then was studied ex vivo using three-dimensional microcomputed tomography imaging, and growth factors and remodeling pathways were explored in renal tissue. The HC kidney showed increased MV density compared with normal (77.68 +/- 5.1 versus 62.9 +/- 4.8 vessels/cm(2); P = 0.04) but blunted endothelial function. Chronic ET-A blockade in HC upregulated renal vascular growth factors, further increased renal MV density (139.9 +/- 8.4 vessels/cm(2); P = 0.001 versus normal and HC), and decreased renal tissue and MV remodeling. Furthermore, ET-A blockade in HC decreased MV tortuosity and improved MV endothelial function, suggesting accelerated stabilization and maturation of neo-vessels. Modulation of renal MV architecture and function in HC is mediated partly by the endogenous ET system. Notably, ET-A blockade enhanced the proliferation and facilitated the maturation of renal MV in the HC kidney and improved renal MV remodeling and function. This study suggests novel renoprotective effects of ET-A blockers and supports further exploration of strategies that target the ET pathway in HC and atherosclerosis.
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Affiliation(s)
- Alejandro R Chade
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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20
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Horstmeyer A, Licht C, Scherr G, Eckes B, Krieg T. Signalling and regulation of collagen I synthesis by ET-1 and TGF-beta1. FEBS J 2006; 272:6297-309. [PMID: 16336267 DOI: 10.1111/j.1742-4658.2005.05016.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Endothelin-1 (ET-1) plays an important role in tissue remodelling and fibrogenesis by inducing synthesis of collagen I via protein kinase C (PKC). ET-1 signals are transduced by two receptor subtypes, the ETA- and ETB-receptors which activate different Galpha proteins. Here, we investigated the expression of both ET-receptor subtypes in human primary dermal fibroblasts and demonstrated that the ETA-receptor is the major ET-receptor subtype expressed. To determine further signalling intermediates, we inhibited Galphai and three phospholipases. Pharmacologic inhibition of Galphai, phosphatidylcholine-phospholipase C (PC-PLC) and phospholipase D (PLD), but not of phospholipase Cbeta, abolished the increase in collagen I by ET-1. Inhibition of all phospholipases revealed similar effects on TGF-beta1 induced collagen I synthesis, demonstrating involvement of PC-PLC and PLD in the signalling pathways elicited by ET-1 and TGF-beta1. ET-1 and TGF-beta1 each stimulated collagen I production and in an additive manner. ET-1 further induced connective tissue growth factor (CTGF), as did TGF-beta1, however, to lower levels. While rapid and sustained CTGF induction was seen following TGF-beta1 treatment, ET-1 increased CTGF in a biphasic manner with lower induction at 3 h and a delayed and higher induction after 5 days of permanent ET-1 treatment. Coincidentally at 5 days of permanent ET-1 stimulation, a switch in ET-receptor subtype expression to the ETB-receptor was observed. We conclude that the signalling pathways induced by ET-1 and TGF-beta1 leading to augmented collagen I production by fibroblasts converge on a similar signalling pathway. Thereby, long-time stimulation by ET-1 resulted in a changed ET-receptor subtype ratio and in a biphasic CTGF induction.
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21
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Cordaillat M, Rugale C, Casellas D, Mimran A, Jover B. Cardiorenal abnormalities associated with high sodium intake: correction by spironolactone in rats. Am J Physiol Regul Integr Comp Physiol 2005; 289:R1137-43. [PMID: 15919735 DOI: 10.1152/ajpregu.00154.2005] [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: 11/22/2022]
Abstract
Reversal by the mineralocorticoid receptor antagonist spironolactone on cardiac and renal abnormalities, associated with long-term (since weaning) administration of a high (2 and 8% NaCl chow, HS2 and HS8) sodium diet, was assessed in Sprague-Dawley rats. At the age of 5 mo, spironolactone (20 or 100 mg/kg, gavage) or placebo were given for 14 days to HS2 and HS8 rats. A group fed a regular diet (0.8% NaCl, NS) remained untreated. High sodium intake had no detectable effect on blood pressure; however, cardiac mass index and cross-sectional area of the carotid artery, as well as albuminuria, were increased only in the HS8 group compared with the control group on NS diet. In addition, a marked reduction in glomerular filtration rate (by 40%), associated with a nonproportional fall in renal plasma flow (thus resulting in a decrease in filtration fraction), was observed only in the HS8 group. No change in cardiac and renal fibrosis was detected. Production of the reactive oxygen species (ROS) by aortic tissue was increased in HS8 rats, whereas ROS production by the heart was unaffected. Only the high dose of spironolactone was effective, as it markedly reversed the cardiac hypertrophy and renal hypofiltration associated with the HS8 feeding. The changes were observed in the absence of any effect on systemic blood pressure and production of ROS. These observations favor aldosterone’s role in the deleterious effects of marked and prolonged increases in sodium intake.
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Affiliation(s)
- Magali Cordaillat
- Groupe Rein et Hypertension, Université Montpellier I, Montpellier, France
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22
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Harris AK, Hutchinson JR, Sachidanandam K, Johnson MH, Dorrance AM, Stepp DW, Fagan SC, Ergul A. Type 2 diabetes causes remodeling of cerebrovasculature via differential regulation of matrix metalloproteinases and collagen synthesis: role of endothelin-1. Diabetes 2005; 54:2638-44. [PMID: 16123352 DOI: 10.2337/diabetes.54.9.2638] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The risk of cerebrovascular disease is four- to sixfold higher in patients with diabetes. Vascular remodeling, characterized by extracellular matrix deposition and an increased media-to-lumen ratio, occurs in diabetes and contributes to the development of complications. However, diabetes-induced changes in the cerebrovascular structure remain unknown. Endothelin-1 (ET-1), a potent vasoconstrictor with profibrotic properties, is chronically elevated in diabetes. To determine diabetes-mediated changes in the cerebrovasculature and the role of ET-1 in this process, type 2 diabetic Goto-Kakizaki (GK) rats were administered an ET(A) receptor antagonist for 4 weeks. Middle cerebral arteries were harvested and studies were performed to determine vascular structure. Tissue and plasma ET-1 levels were increased in GK rats compared with controls. Significant medial hypertrophy and collagen deposition resulted in an increased wall-to-lumen ratio in diabetic rats that was reduced by ET(A) receptor antagonism. Vascular matrix metalloproteinase (MMP)-2 activity was higher, but MMP-1 levels were significantly reduced in GK rats, and MMP levels were restored to control levels by ET(A) receptor antagonism. We conclude that ET-1 promotes cerebrovascular remodeling in type 2 diabetes through differential regulation of MMPs. Augmented cerebrovascular remodeling may contribute to an increased risk of stroke in diabetes, and ET(A) receptor antagonism may offer a novel therapeutic target.
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Affiliation(s)
- Alex K Harris
- Medical College of Georgia, Clinical Pharmacy CJ-1020, Augusta, GA 30912, USA
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23
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Spiers JP, Kelso EJ, Siah WF, Edge G, Song G, McDermott BJ, Hennessy M. Alterations in vascular matrix metalloproteinase due to ageing and chronic hypertension: effects of endothelin receptor blockade. J Hypertens 2005; 23:1717-24. [PMID: 16093917 DOI: 10.1097/01.hjh.0000176787.04753.ee] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the effects of age and dual endothelin (ET)A/ETB receptor antagonism (bosentan) on aortic matrix metalloproteinase (MMP) abundance and tissue inhibitor of metalloproteinase (TIMP) expression in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). METHODS Male SHR and control WKY rats were randomly assigned to receive placebo or bosentan (100 mg/kg per day) for 3 months. Animals were killed under terminal anaesthesia at either 20 weeks (adult) or 17-20 months (senescent). Aortic gelatinase activity was determined by zymography, whereas MT-1 MMP and TIMP-1 expression were assessed by immunoblotting. RESULTS In WKY rats, aortic MMP-2 but not proMMP-2 activity was 3.6-fold higher (P < 0.02) in the senescent compared with the adult group. TIMP-1 (twofold) and MT-1 MMP (3.8-fold) expression increased (P < 0.05) with age in the WKY groups. Short-term hypertension (adult SHR versus adult WKY) increased MMP-2 to 74.7 +/- 14.1 from 18.9 +/- 3.5 arbitrary units (AU) (P = 0.0012), but did not alter proMMP-2 activity. This increased further on progression to chronic hypertension (117.4 +/- 12.2 versus 74.7 +/- 14.1 AU; P < 0.02). Bosentan decreased MMP-2 (78.9 +/- 3.8 versus 117.4 +/- 12.2 AU; P = 0.014) and proMMP-2 activity (P < 0.006) in the senescent SHR group. CONCLUSION Ageing and the development/progression of hypertension are associated with increased MMP-2 activity in the aorta, which is consistent with ongoing remodelling of the vasculature. However, the underlying mechanisms regulating MMP-2 abundance in ageing and hypertension appear to be divergent, as MT-1 MMP expression is differentially altered. Dual ETA/ETB receptor antagonism did not alter the age-dependent increase in aortic MMP activity in normotensive rats. However, bosentan decreased pro and active MMP-2 activity in senescent SHR rats, indicating that ET modulates late events in vascular remodelling in hypertension.
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MESH Headings
- Aging
- Animals
- Antihypertensive Agents/pharmacology
- Aorta, Thoracic/enzymology
- Blotting, Western
- Bosentan
- Endothelin A Receptor Antagonists
- Endothelin B Receptor Antagonists
- Endothelin Receptor Antagonists
- Endothelium, Vascular/enzymology
- Enzyme Precursors/metabolism
- Gelatinases/metabolism
- Hypertension/metabolism
- Male
- Matrix Metalloproteinase 2/metabolism
- Matrix Metalloproteinases/metabolism
- Metalloendopeptidases/metabolism
- Microscopy, Fluorescence
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Receptor, Endothelin A/genetics
- Receptor, Endothelin A/metabolism
- Receptor, Endothelin B/genetics
- Receptor, Endothelin B/metabolism
- Receptors, Endothelin/genetics
- Receptors, Endothelin/metabolism
- Reference Standards
- Sulfonamides/pharmacology
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Affiliation(s)
- James P Spiers
- Department of Pharmacology and Therapeutics, Trinity Centre for Health Sciences, Trinity College Dublin, St. James's Hospital, James's Street, Dublin 8, Ireland.
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24
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Schiffrin EL. Vascular endothelin in hypertension. Vascul Pharmacol 2005; 43:19-29. [PMID: 15955745 DOI: 10.1016/j.vph.2005.03.004] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 01/17/2005] [Accepted: 03/01/2005] [Indexed: 12/31/2022]
Abstract
Endothelins are powerful vasoconstrictor peptides that also play numerous other functions in many different organs. Endothelin-1 (ET-1) is the most abundant and important of this family of peptides in blood vessels. Production of ET-1 is increased in the endothelium and the kidney in salt-dependent models of hypertension (e.g.: DOCA-salt rats and Dahl salt-sensitive rats, in salt-loaded SHR-SP, in angiotensin II-infused and in diabetic rats). ET-1 elicits an inflammatory response by increasing oxidant stress in the vascular wall, which induces vascular remodeling and endothelial dysfunction found in the hypertensive models that exhibit an endothelin-mediated component. Endothelin receptor antagonism reduces blood pressure and vascular hypertrophic remodeling present in these hypertensive models. Patients with stage 2 hypertension have enhanced vascular expression of ET-1. Endothelin receptor antagonists lower blood pressure in hypertensive patients. They could become therapeutic agents for prevention of target organ damage in hypertension and in type 2 diabetes, chronic renal failure and congestive heart failure. Side effects of endothelin receptor blockers have prevented up to the present their development for these indications. New endothelin antagonists devoid of these side effects, or alternatively inhibitors of the endothelin converting enzymes that generate ET-1 may in the future become available to block the endothelin system. However, to date endothelin antagonists have been approved only for the treatment of primary pulmonary hypertension, a rapidly fatal condition in which the endothelin system plays an important role and endothelin antagonists exert favorable effects.
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Affiliation(s)
- Ernesto L Schiffrin
- CIHR Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada.
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25
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Kadoglou NP, Daskalopoulou SS, Perrea D, Liapis CD. Matrix metalloproteinases and diabetic vascular complications. Angiology 2005; 56:173-89. [PMID: 15793607 DOI: 10.1177/000331970505600208] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Diabetes mellitus (DM) is associated with an increased incidence of cardiovascular events and microvascular complications. These complications contribute to the morbidity and mortality associated with DM. There is increasing evidence supporting a role for matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of matrix metalloproteinases - TIMPs) in the atherosclerotic process. However, the relationship between MMPs/TIMPs and diabetic angiopathy is less well defined. Hyperglycemia directly or indirectly (eg, via oxidative stress or advanced glycation products) increases MMP expression and activity. These changes are associated with histologic alterations in large vessels. On the other hand, low proteolytic activity of MMPs contributes to diabetic nephropathy. Within atherosclerotic plaques an imbalance between MMPs and TIMPs may induce matrix degradation, resulting in an increased risk of plaque rupture. Furthermore, because MMPs enhance blood coagulability, MMPs and TIMPs may play a role in acute thrombotic occlusion of vessels and consequent cardiovascular events. Some drugs can inhibit MMP activity. However, the precise mechanisms involved are still not defined. Further research is required to demonstrate the causative relationship between MMPs/TIMPs and diabetic atherosclerosis. It also remains to be established if the long-term administration of MMP inhibitors can prevent acute cardiovascular events.
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Affiliation(s)
- Nikolaos P Kadoglou
- Department of Vascular Surgery, Athens University Medical School, Athens, Greece.
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26
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Rajnoch J, Lodererova A, Szabo A, Honsova E, Vannay A, Bloudickova S, Matl I, Viklicky O. Regulators of angiogenesis in renal ischemia/reperfusion injury in normotensive and hypertensive rats: Effect of tacrolimus. Transplant Proc 2005; 37:352-4. [PMID: 15808641 DOI: 10.1016/j.transproceed.2004.12.154] [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: 11/19/2022]
Abstract
The aim of this study was to evaluate the role of proangiogenic growth factors in an experimental model of ischemia/reperfusion injury (I/R) in both normotensive and hypertensive rats. Renal ischemic injury was induced in transgenic rats rendered hypertensive due to renin overproduction [TGR (mREN-2)-27] and in normotensive Hannover Sprague-Dawley rats (HanSD). Animals were treated for 12 weeks with either tacrolimus (TAC, 0.1 mg/kg per day, intramuscularly [IM]) or placebo. After 12 weeks, kidneys were harvested for morphologic, immunohistochemical, and RT-PCR analysis. Both normotensive and hypertensive untreated rats developed significantly greater proteinuria and glomerulosclerosis compared with TAC-treated rats. Immunohistologically, TGR showed higher basic fibroblast growth factor (bFGF) protein expression compared with normotensive HanSD. TAC-treated rats had higher bFGF protein expression than untreated rats. Vascular endothelial growth factor (VEGF) protein expression in glomeruli was more increased in TGR after I/R than in sham-operated animals. TAC-treated TGR hosts developed higher VEGF mRNA expression compared with both untreated and sham groups; however, there were no differences between treated and untreated normotensive HanSD animals. bFGF is involved in the fibrogenesis induced by hypertension and I/R injury. The nature of the increase in proangiogeneic growth factor expression among tacrolimus-treated animals remains to be elucidated.
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Affiliation(s)
- J Rajnoch
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
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27
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Goddard J, Johnston NR, Hand MF, Cumming AD, Rabelink TJ, Rankin AJ, Webb DJ. Endothelin-A receptor antagonism reduces blood pressure and increases renal blood flow in hypertensive patients with chronic renal failure: a comparison of selective and combined endothelin receptor blockade. Circulation 2004; 109:1186-93. [PMID: 14981006 DOI: 10.1161/01.cir.0000118499.69469.51] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Endothelin (ET) is implicated in the pathophysiology of chronic renal failure (CRF). We therefore studied the systemic and renal hemodynamic effects of ET receptor antagonists in CRF and examined differences between selective ETA, selective ETB, and combined ETA/B receptor blockade. METHODS AND RESULTS We conducted a randomized, placebo-controlled, double-blind, 4-way crossover study comparing selective ET receptor antagonists BQ-123 (ETA) and BQ-788 (ETB), given alone and in combination, in acute studies in 8 hypertensive CRF patients and 8 matched healthy controls. BQ-123, alone and in combination with BQ-788, reduced blood pressure in CRF, particularly with BQ-123 alone (mean arterial pressure: controls -4+/-2%, CRF -13+/-2%, P<0.01 versus placebo). In CRF, in the face of this fall in blood pressure, BQ-123 substantially increased renal blood flow (38.8+/-23.9%, P<0.01 versus placebo) and reduced renal vascular resistance (-44.5+/-11.3%, P<0.01 versus placebo) when given alone but not when combined with BQ-788. These changes were accompanied by a reduction in effective filtration fraction. BQ-123, alone or in combination with BQ-788, had minimal effects on the renal circulation in healthy controls, and BQ-788 alone produced both systemic and renal vasoconstriction in CRF and healthy controls. CONCLUSIONS ETA receptor antagonism was highly effective in lowering blood pressure in CRF patients currently treated for hypertension. In addition, there were effects consistent with a renoprotective action. However, because the ETB receptor appears to play a key role in the maintenance of tonic renal vasodilation, combined ETA/B receptor antagonism, although it lowered blood pressure, did not confer these renal benefits.
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Affiliation(s)
- Jane Goddard
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
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28
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Savoia C, Schiffrin EL. Significance of recently identified peptides in hypertension: endothelin, natriuretic peptides, adrenomedullin, leptin. Med Clin North Am 2004; 88:39-62. [PMID: 14871050 DOI: 10.1016/s0025-7125(03)00122-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Arterial hypertension is one of the major risk factors in cardiovascular and renal disease. Advances in the study of pathophysiologic mechanisms and the relationship between several regulatory systems provide the basis for development of more selective therapeutic strategies. The increasing understanding of the role played by ETs, natriuretic peptides, AM, and leptin opens new frontiers in the care of hypertension and its complications, coronary artery disease and heart failure and other forms of cardiovascular disease.
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Affiliation(s)
- Carmine Savoia
- Experimental Hypertension Laboratory of the CIHR Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, West Montreal, QC, Canada
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29
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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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Ergul A, Portik-Dobos V, Giulumian AD, Molero MM, Fuchs LC. Stress upregulates arterial matrix metalloproteinase expression and activity via endothelin A receptor activation. Am J Physiol Heart Circ Physiol 2003; 285:H2225-32. [PMID: 12842810 DOI: 10.1152/ajpheart.00133.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Degradation of the extracellular matrix proteins by matrix metalloproteinases (MMP) is an important regulatory step in the vascular remodeling process. Recent studies demonstrated that ETA receptors regulate cardiac MMP activity and fibrosis in DOCA-salt hypertension. However, little is known about endothelin (ET)-1 regulation of vascular MMP activity in hypertension. Thus early changes in ET-1-mediated regulation of MMP activity were measured in borderline hypertensive rats that develop impaired vasorelaxation and hypertension with chronic exposure to stress. Experiments were performed after 10 days of exposure to the behavioral stressor, air-jet stress, but before the onset of stress-induced hypertension. Study groups were 1) control (n = 8); 2) air-jet stress for 10 days (n = 8); 3) control plus ETA antagonist ABT-627 (n = 4), and 4) air-jet stress plus ETA antagonist (n = 4). MMP activity in the thoracic aorta was assessed by gelatin zymography. MMP protein and tissue ET-1 levels were evaluated by immunohistochemistry, and ET receptor density was determined by immunoblotting. Exposure to stress caused a twofold increase in plasma ET-1 levels (P < 0.05), and there was increased ET-1 staining at the tissue level. Total MMP activity and expression of MMP-2 and MMP-9 were increased in the stress group. ETA receptor antagonism prevented the increase in MMP expression and activation in the stress group. These results provide evidence that the MMP system is activated before the development of hypertension and ET-1 mediates these early events in vascular remodeling.
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Affiliation(s)
- Adviye Ergul
- Clinical Pharmacy CJ-1020, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912, USA.
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Chade AR, Best PJ, Rodriguez-Porcel M, Herrmann J, Zhu X, Sawamura T, Napoli C, Lerman A, Lerman LO. Endothelin-1 receptor blockade prevents renal injury in experimental hypercholesterolemia. Kidney Int 2003; 64:962-9. [PMID: 12911546 DOI: 10.1046/j.1523-1755.2003.00170.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The potent vasoconstrictor endothelin-1 is involved in regulation of renal function, and is up-regulated in hypercholesterolemia (HC), a risk factor for renal disease that increases oxidative stress and impairs renal hemodynamic responses. However, the involvement of endothelin (ET) in this disease process is yet unknown. METHODS Regional renal hemodynamics and function in vivo were quantified in pigs at baseline and during infusion of acetylcholine using electron beam computed tomography after a 12-week normal diet (N = 6), HC diet (N = 6), and HC diet orally supplemented (4 mg/kg/day) with the selective ET receptor-A (ET-A) blocker ABT-627 (HC+ET-A, N = 6). Plasma levels of 8-epi-PGF2-alpha-isoprostanes, markers of oxidative stress, were measured using enzyme immunoassay, and renal tissue was studied ex vivo using Western blotting, electrophoretic mobility shift assay, and immunohistochemistry. RESULTS Total and low-density lipoprotein (LDL) cholesterol were similarly increased, but isoprostanes were decreased in HC+ET-A compared to HC alone. Basal renal perfusion was similar among the groups, while glomerular filtration rate (GFR) increased in HC+ET-A compared to HC. Stimulated perfusion and GFR were blunted in HC, but normalized in HC+ET-A. Moreover, ET blockade increased expression of endothelial nitric oxide synthase, and decreased endothelial expression of the oxidized-LDL receptor LOX-1, as well as tubular immunoreactivity of inducible nitric oxide synthase, nitrotyrosine, nuclear factor-kappaB, transforming growth factor-beta, and tubulointerstitial and perivascular trichrome staining. CONCLUSION ET-A blockade improves renal hemodynamic and function in HC, and decreases oxidative stress, and renal vascular and tubulointerstitial inflammation and fibrosis. These findings support a role for the endogenous ET system in renal injury in HC and atherosclerosis.
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Affiliation(s)
- Alejandro R Chade
- Department of Internal Medicine, Division of Hypertension, Mayo Clinic, Rochester, Minnesota, USA
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Donnelly R, Collinson DJ, Manning G. Hypertension, matrix metalloproteinases and target organ damage. J Hypertens 2003; 21:1627-30. [PMID: 12923392 DOI: 10.1097/00004872-200309000-00009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
Endothelin-1 (ET-1) was first characterized as a potent vasoconstrictor and is overexpressed in the vasculature in different models of hypertension, such as deoxycorticosterone acetate-salt rats, Dahl salt-sensitive rats, and stroke-prone spontaneously hypertensive rats. Moreover, patients with moderate to severe hypertension present increased vascular levels of prepro-ET-1 mRNA. In addition to their blood pressure-lowering effects, ET receptor antagonists are able to reduce vascular growth. Recent data suggest the involvement of an inflammatory response in the effects of ET-1, which contributes to vascular remodeling and endothelial dysfunction. Increasing evidence underscores the potential therapeutic benefit of ET receptor antagonists in different hypertension-related complications, not only in essential hypertension, but also in patients with type 2 diabetes.
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Affiliation(s)
- Marc Iglarz
- Clinical Research Institute of Montreal, 110 Pine Avenue West, Quebec H2W 1R7, Canada
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Goto K, Miyauchi T. [New expansion of endothelin research: perspectives for clinical application of endothelin-receptor antagonists]. Nihon Yakurigaku Zasshi 2003; 121:91-101. [PMID: 12616854 DOI: 10.1254/fpj.121.91] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Three isopeptides of endothelin (ET-1, -2, and -3) exert various actions through stimulation of two sub-types of receptor (ETA and ETB). Vascular endothelial cells produce only ET-1. In addition to its powerful vasoconstrictor action, ET-1 has direct mitogenic actions on cardiovascular tissues, as well as comitogennic actions with a wide variety of growth factors and vasoactive substances. ET-1 also promotes the synthesis and secretion of growth factors and various substances, including extracellular constituents. These effects of endogenous ET-1 would naturally be thought to be concerned with the development and/or aggravation of chronic cardiovascular diseases; e.g., hypertension, pulmonary hypertension, vascular remodeling (stenosis, atherosclerosis), renal failure, and heart failure. A large number of peptide and orally active non-peptide endothelin receptor antagonists have been developed, and utilized to analyze physiological and pathophysiological roles of endogenous ET-1. These antagonists have been shown to exert excellent therapeutic effects in animal models of various kinds of diseases by either acute or chronic treatment. Therapeutic treatment of patients suffering from the above-mentioned cardiovascular diseases with ET-receptor antagonists have also been taking place, and bosentan (ETA/ETB antagonist) was recently approved by the FDA as a formal therapeutic drug for pulmonary hypertension. In this review, perspectives for therapeutic applicability of ET-receptor antagonists will be explored.
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Affiliation(s)
- Katsutoshi Goto
- Department of Pharmacology, Institute of Basic Medical Sciences, University of Tsukuba, 1-1-1, Tennnoudai, Tsukuba, Ibaraki 305-8575, Japan.
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