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Gutiérrez A, Gómez Del Val A, Contreras C, Olmos L, Sánchez A, Prieto D. Calcium handling coupled to the endothelin ET A and ET B receptor-mediated vasoconstriction in resistance arteries: Differential regulation by PI3K, PKC and RhoK. Eur J Pharmacol 2023; 956:175948. [PMID: 37541372 DOI: 10.1016/j.ejphar.2023.175948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/14/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Abnormal endothelin-1 (ET-1) activity is involved in the pathogenesis of vascular diseases such as essential and pulmonary arterial hypertension, coronary artery disease, and cerebrovascular disease, blockade of ET receptors having shown efficacy in clinical assays and experimental models of hypertension. Augmented Ca2+ influx and changes in Ca2+ sensitization associated with arterial vasoconstriction underlie increased systemic vascular resistance in hypertension. Since peripheral resistance arteries play a key role in blood pressure regulation, we aimed to determine here the specific Ca2+ signaling mechanisms linked to the ET receptor-mediated vasoconstriction in resistance arteries and their selective regulation by protein kinase C (PKC), Rho kinase (RhoK), the phosphatidylinositol 3-kinase (PI3K) and the mitogen-activated protein kinase (MAPK). ET-1-induced contraction was mediated by the endothelin ETA receptor with a minor contribution of vascular smooth muscle (VSM) endothelin ETB receptors. ET receptor activation elicited Ca2+ mobilization from intracellular stores, extracellular Ca2+ influx and Ca2+ sensitization associated with contraction in resistance arteries. Vasoconstriction induced by ET-1 was largely dependent on activation of canonical transient receptor potential channel 3 (TRPC3) and extracellular Ca2+ influx through nifedipine-sensitive voltage-dependent Ca2+ channels. PI3K inhibition reduced intracellular Ca2+ mobilization and Ca2+ entry without altering vasoconstriction elicited by ET-1, while PKC has dual opposite actions by enhancing Ca2+ influx associated with contraction, and by inhibiting Ca2+ release from intracellular stores. RhoK was a major determinant of the enhanced sensitivity of the contractile filaments underlying ET-1 vasoconstriction, with also a modulatory positive action on Ca2+ influx and intracellular Ca2+ release. Augmented RhoK and PKC activities are involved in vascular dysfunction in hypertension and vascular complications of insulin-resistant states, and these kinases are thus potential pharmacological targets in vascular diseases in which the ET pathway is impaired.
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Affiliation(s)
- Alejandro Gutiérrez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Alfonso Gómez Del Val
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Cristina Contreras
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Lucia Olmos
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Ana Sánchez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain.
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2
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Abstract
The development of pulmonary hypertension (PH) is common and has adverse prognostic implications in patients with heart failure due to left heart disease (LHD), and thus far, there are no known treatments specifically for PH-LHD, also known as group 2 PH. Diagnostic thresholds for PH-LHD, and clinical classification of PH-LHD phenotypes, continue to evolve and, therefore, present a challenge for basic and translational scientists actively investigating PH-LHD in the preclinical setting. Furthermore, the pathobiology of PH-LHD is not well understood, although pulmonary vascular remodeling is thought to result from (1) increased wall stress due to increased left atrial pressures; (2) hemodynamic congestion-induced decreased shear stress in the pulmonary vascular bed; (3) comorbidity-induced endothelial dysfunction with direct injury to the pulmonary microvasculature; and (4) superimposed pulmonary arterial hypertension risk factors. To ultimately be able to modify disease, either by prevention or treatment, a better understanding of the various drivers of PH-LHD, including endothelial dysfunction, abnormalities in vascular tone, platelet aggregation, inflammation, adipocytokines, and systemic complications (including splanchnic congestion and lymphatic dysfunction) must be further investigated. Here, we review the diagnostic criteria and various hemodynamic phenotypes of PH-LHD, the potential biological mechanisms underlying this disorder, and pressing questions yet to be answered about the pathobiology of PH-LHD.
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Affiliation(s)
- Jessica H Huston
- Division of Cardiology, Department of Internal Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA (J.H.H.)
| | - Sanjiv J Shah
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL (S.J.S.)
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Young AP, Zhu J, Bagher AM, Denovan-Wright EM, Howlett SE, Kelly MEM. Endothelin B receptor dysfunction mediates elevated myogenic tone in cerebral arteries from aged male Fischer 344 rats. GeroScience 2021; 43:1447-1463. [PMID: 33403617 DOI: 10.1007/s11357-020-00309-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 12/01/2020] [Indexed: 02/08/2023] Open
Abstract
The human brain requires adequate cerebral blood flow to meet the high demand for nutrients and to clear waste products. With age, there is a chronic reduction in cerebral blood flow in small resistance arteries that can eventually limit proper brain function. The endothelin system is a key mediator in the regulation of cerebral blood flow, but the contributions of its constituent receptors in the endothelial and vascular smooth muscle layers of cerebral arteries have not been well defined in the context of aging. We isolated posterior cerebral arteries from young and aged Fischer 344 rats, as well as ETB receptor knock-out rats and mounted the vessels in plexiglass pressure myograph chambers to measure myogenic tone in response to increasing pressure and targeted pharmacological treatments. We used an ETA receptor antagonist (BQ-123), an ETB receptor antagonist (BQ-788), endothelin-1, an endothelin-1 synthesis inhibitor (phosphoramidon), and vessel denudation to dissect the roles of each receptor in aging vasculature. Aged rats exhibited a higher myogenic tone than young rats, and the tone was sensitive to the ETA antagonist, BQ-123, but insensitive to the ETB antagonist, BQ-788. By contrast, the tone in the vessels from young rats was raised by BQ-788 but unaffected by BQ-123. When the endothelial layer that is normally enriched with ETB1 receptors was removed from young vessels, myogenic tone increased. However, denudation of the endothelial layer did not influence vessels from aged animals. This indicated that endothelial ETB1 receptors were not functional in the vessels from aged rats. There was also an increase in ETA receptor expression with age, whereas ETB receptor expression remained constant between young and aged animals. These results demonstrate that in young vessels, ETB1 receptors maintain a lower myogenic tone, but in aged vessels, a loss of ETB receptor activity allows ETA receptors in vascular smooth muscle cells to raise myogenic tone. Our findings have potentially important clinical implications for treatments to improve cerebral perfusion in older adults with diseases characterized by reduced cerebral blood flow.
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Affiliation(s)
- Alexander P Young
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Jiequan Zhu
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Amina M Bagher
- Department of Pharmacology and Toxicology, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Susan E Howlett
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.,Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, NS, Canada
| | - Melanie E M Kelly
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 4R2, Canada. .,Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada.
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Chronic real-time particulate matter exposure causes rat pulmonary arteriole hyperresponsiveness and remodeling: The role of ET BR-ERK1/2 signaling. Toxicol Appl Pharmacol 2020; 403:115154. [PMID: 32710959 DOI: 10.1016/j.taap.2020.115154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/17/2020] [Accepted: 07/18/2020] [Indexed: 01/03/2023]
Abstract
Exposure to air pollution is associated with the incidence of respiratory diseases. The present study evaluated the pulmonary vascular system injury by chronic real-time particulate matter (PM10) exposure and investigated the underlying mechanisms. Rats were exposed to PM10 or filtered air for 2 to 4 months using a whole body exposure system, and intraperitoneally injected with the MEK1/2 inhibitor U0126. Right heart catheterization and myography were performed to detect lung function and pulmonary vascular reactivity, respectively. Western blotting, qRT-PCR, enzyme-linked immunosorbent assay and histological analyses were used to detect the effects and mechanisms by which PM10 exposure-induced pulmonary vascular dysfunction. Functional experiment results showed that PM10 exposure increased the pulmonary artery pressure of rats and caused endothelin B receptor (ETBR)-mediated pulmonary arteriole hyperreactivity. U0126 significantly rescued these pathological changes. PM10 exposure upregulated the contractile ETBR of pulmonary arteriolar smooth muscle, and damaged pulmonary artery endothelial cells to induce the release of more endothelin 1 (ET-1). The upregulated ETBR bound to increased ET-1 induced pulmonary arteriolar hyperresponsiveness and remodeling. U0126 inhibited the PM10 exposure-induced upregulation of ETBR in pulmonary arteriole, ETBR-mediated pulmonary arterial hyperresponsiveness and vascular remodeling. In conclusion, chronic real-time particulate matter exposure can activate the ERK1/2 signaling, thereby inducing the upregulation of contractile ETBR in pulmonary arteriole, which may be involved in pulmonary arteriole hyperresponsiveness and remodeling in rats. These findings provide new mechanistic evidence of PM10 exposure-induced respiratory diseases, and a new possible target for treatment.
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Ozen G, Benyahia C, Amgoud Y, Patel J, Abdelazeem H, Bouhadoun A, Yung S, Li F, Mahieddine Y, Silverstein AM, Castier Y, Cazes A, Longrois D, Clapp LH, Norel X. Interaction between PGI2 and ET-1 pathways in vascular smooth muscle from Group-III pulmonary hypertension patients. Prostaglandins Other Lipid Mediat 2020; 146:106388. [DOI: 10.1016/j.prostaglandins.2019.106388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/08/2019] [Accepted: 10/24/2019] [Indexed: 12/16/2022]
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Docherty CK, Harvey KY, Mair KM, Griffin S, Denver N, MacLean MR. The Role of Sex in the Pathophysiology of Pulmonary Hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1065:511-528. [PMID: 30051404 DOI: 10.1007/978-3-319-77932-4_31] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a progressive disease characterised by increased pulmonary vascular resistance and pulmonary artery remodelling as result of increased vascular tone and vascular cell proliferation, respectively. Eventually, this leads to right heart failure. Heritable PAH is caused by a mutation in the bone morphogenetic protein receptor-II (BMPR-II). Female susceptibility to PAH has been known for some time, and most recent figures show a female-to-male ratio of 4:1. Variations in the female sex hormone estrogen and estrogen metabolism modify FPAH risk, and penetrance of the disease in BMPR-II mutation carriers is increased in females. Several lines of evidence point towards estrogen being pathogenic in the pulmonary circulation, and thus increasing the risk of females developing PAH. Recent studies have also suggested that estrogen metabolism may be crucial in the development and progression of PAH with studies indicating that downstream metabolites such as 16α-hydroxyestrone are upregulated in several forms of experimental pulmonary hypertension (PH) and can cause pulmonary artery smooth muscle cell proliferation and subsequent vascular remodelling. Conversely, other estrogen metabolites such as 2-methoxyestradiol have been shown to be protective in the context of PAH. Estrogen may also upregulate the signalling pathways of other key mediators of PAH such as serotonin.
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Affiliation(s)
- Craig K Docherty
- Research Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Katie Yates Harvey
- Research Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Kirsty M Mair
- Research Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sinead Griffin
- Research Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Nina Denver
- Research Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Margaret R MacLean
- Research Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Angus JA, Hughes RJA, Wright CE. Distortion of K B estimates of endothelin-1 ET A and ET B receptor antagonists in pulmonary arteries: Possible role of an endothelin-1 clearance mechanism. Pharmacol Res Perspect 2018; 5. [PMID: 29226623 PMCID: PMC5723704 DOI: 10.1002/prp2.374] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 10/23/2017] [Indexed: 11/08/2022] Open
Abstract
Dual endothelin ETA and ETB receptor antagonists are approved therapy for pulmonary artery hypertension (PAH). We hypothesized that ETB receptor‐mediated clearance of endothelin‐1 at specific vascular sites may compromise this targeted therapy. Concentration‐response curves (CRC) to endothelin‐1 or the ETB agonist sarafotoxin S6c were constructed, with endothelin receptor antagonists, in various rat and mouse isolated arteries using wire myography or in rat isolated trachea. In rat small mesenteric arteries, bosentan displaced endothelin‐1 CRC competitively indicative of ETA receptor antagonism. In rat small pulmonary arteries, bosentan 10 μmol L−1 left‐shifted the endothelin‐1 CRC, demonstrating potentiation consistent with antagonism of an ETB receptor‐mediated endothelin‐1 clearance mechanism. Removal of endothelium or L‐NAME did not alter the EC50 or Emax of endothelin‐1 nor increase the antagonism by BQ788. In the presence of BQ788 and L‐NAME, bosentan displayed ETA receptor antagonism. In rat trachea (ETB), bosentan was a competitive ETB antagonist against endothelin‐1 or sarafotoxin S6c. Modeling showed the importance of dual receptor antagonism where the potency ratio of ETA to ETB antagonism is close to unity. In conclusion, the rat pulmonary artery is an example of a special vascular bed where the resistance to antagonism of endothelin‐1 constriction by ET dual antagonists, such as bosentan or the ETB antagonist BQ788, is possibly due to the competition of potentiation of endothelin‐1 by blockade of ETB‐mediated endothelin‐1 clearance located on smooth muscle and antagonism of ETA‐ and ETB‐mediated contraction. This conclusion may have direct application for the efficacy of endothelin‐1 antagonists for treating PAH.
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Affiliation(s)
- James A Angus
- Cardiovascular Therapeutics Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Vic., Australia
| | - Richard J A Hughes
- Cardiovascular Therapeutics Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Vic., Australia
| | - Christine E Wright
- Cardiovascular Therapeutics Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Vic., Australia
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8
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Chies AB, de Oliveira PB, Rossignoli PDS, Baptista RDFF, de Lábio RW, Payão SLM. Prostanoids counterbalance the synergism between endothelin-1 and angiotensin II in mesenteric veins of trained rats. Peptides 2017; 88:67-73. [PMID: 28012855 DOI: 10.1016/j.peptides.2016.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/15/2016] [Accepted: 12/20/2016] [Indexed: 11/30/2022]
Abstract
Exercise-induced adaptations of the modulating mechanisms that influence the angiotensin (Ang II) responses assume different features depending on the venous bed. In femoral veins, exercise mobilizes vasodilator prostanoids to cooperate with NO in order to maintain reduced Ang II responses. On the other hand, exercise's influence on the Ang II responses in veins that drain blood from the mesenteric region has been poorly described. Therefore, the present study aimed to identify the effects of a single bout of exercise, as well as exercise training, on the Ang II responses in mesenteric veins. The present study also aimed to investigate the involvement of prostanoids, NO and ET-1 in eventual exercise-induced modifications in these veins. To this end, mesenteric veins taken from resting-sedentary, exercised-sedentary, resting-trained and exercised-trained animals were studied in organ baths. In addition, the mRNA expression of prepro-endothelin-1 (ppET-1), as well as that of the ETA and ETB receptors, were quantified by real-time PCR in these veins. The results show that, either in absence or in presence of L-NAME, the Ang II responses were not different between groups. In the presence of indomethacin, higher Ang II responses were observed in the resting-trained animals than in the resting-sedentary animals. This difference, however, disappeared when L-NAME, BQ-123 or BQ-788 were added during incubation. In addition, no differences in ppET-1, ETA or ETB mRNA expression were observed between groups. Furthermore, in the presence of PD123,319, the Ang II responses in the exercised-sedentary animals were higher than those in the resting-sedentary animals. In conclusion, exercise training mobilizes endothelin-1 (ET-1) to reinforce the Ang II-induced responses mainly through ETA activation. On the other hand, vasodilator prostanoids are mobilized to act in parallel with NO in order to counterbalance the Ang II responses that have been potentiated by ET-1 in these trained animals.
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Lohsiriwat V, Scholefield JH, Wilson VG, Dashwood MR. Endothelin-1 and its receptors on haemorrhoidal tissue: a potential site for therapeutic intervention. Br J Pharmacol 2017; 174:569-579. [PMID: 28095606 DOI: 10.1111/bph.13719] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/15/2016] [Accepted: 07/10/2016] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Haemorrhoids is a common anorectal condition affecting millions worldwide. We have studied the effect of endothelin-1 (ET-1) and the role of endothelin ETA and ETB receptors in haemorrhoid tissue. EXPERIMENTAL APPROACH Protein expression of ET-1, ETA and ETB receptors were compared between haemorrhoids and normal rectal submucosa using Western blot analysis, with the localization of proteins determined by autoradiography and immunohistochemistry. Effects of ET-1 and sarafotoxin 6a on human colonic and rectal arteries and veins was assessed by wire myography and the involvement of receptor subtypes established by selective antagonists. KEY RESULTS Dense binding of [125 I]-ET-1 to haemorrhoidal sections was reduced by selective receptor antagonists. A higher density of ETB than ETA receptors was found in haemorrhoidal, than in control rectal tissue and confirmed by Western blot analysis. ETA and ETB receptors were localized to smooth muscle of haemorrhoidal arteries and veins, with ETB receptors on the endothelium. Human colonic and rectal arteries and veins were similarly sensitive to ET-1 and affected by the ETA selective antagonist, but sarafotoxin S6a-induced contractions were more pronounced in veins and antagonized by a selective ETB receptor antagonist. CONCLUSIONS AND IMPLICATIONS ETA and ETB receptors are present in human haemorrhoids with ETB receptors predominating. ETA receptors are activated by ET-1 to mediate a contraction in arteries and veins, but the latter are selectively activated by sarafotoxin S6a - a response that involves ETB receptors at low concentrations. Selective ETB agonists may have therapeutic potential to reduce congestion of the haemorrhoidal venous sinusoids.
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Affiliation(s)
- Varut Lohsiriwat
- Division of Gastrointestinal Surgery, Queen's Medical Centre, University of Nottingham, Nottingham, UK
| | - John H Scholefield
- Division of Gastrointestinal Surgery, Queen's Medical Centre, University of Nottingham, Nottingham, UK
| | - Vincent G Wilson
- School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Michael R Dashwood
- Royal Free Hospital Campus, University College Medical School, London, UK
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Miller E, Czopek A, Duthie KM, Kirkby NS, van de Putte EEF, Christen S, Kimmitt RA, Moorhouse R, Castellan RFP, Kotelevtsev YV, Kuc RE, Davenport AP, Dhaun N, Webb DJ, Hadoke PWF. Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling. Hypertension 2016; 69:275-285. [PMID: 28028193 PMCID: PMC5222555 DOI: 10.1161/hypertensionaha.115.07031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 01/02/2016] [Accepted: 11/30/2016] [Indexed: 01/06/2023]
Abstract
Supplemental Digital Content is available in the text. The role of smooth muscle endothelinB (ETB) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ETB receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ETB receptors were selectively deleted from smooth muscle by crossing floxed ETB mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ETB deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ETB was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ETB-mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ETB-mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ETB knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ETB blockade–mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ETB-mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ETB knockout mice. In the absence of other pathology, ETB receptors in vascular smooth muscle make a small but significant contribution to ETB-dependent regulation of BP. These ETB receptors have no effect on vascular contraction or neointimal remodeling.
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Affiliation(s)
- Eileen Miller
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Alicja Czopek
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Karolina M Duthie
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Nicholas S Kirkby
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Elisabeth E Fransen van de Putte
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Sibylle Christen
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Robert A Kimmitt
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Rebecca Moorhouse
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Raphael F P Castellan
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Yuri V Kotelevtsev
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Rhoda E Kuc
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Anthony P Davenport
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Neeraj Dhaun
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - David J Webb
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Patrick W F Hadoke
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.).
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11
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Singh J, Shah R, Singh D. Inundation of asthma target research: Untangling asthma riddles. Pulm Pharmacol Ther 2016; 41:60-85. [PMID: 27667568 DOI: 10.1016/j.pupt.2016.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/11/2016] [Accepted: 09/20/2016] [Indexed: 12/31/2022]
Abstract
Asthma is an inveterate inflammatory disorder, delineated by the airway inflammation, bronchial hyperresponsiveness (BHR) and airway wall remodeling. Although, asthma is a vague term, and is recognized as heterogenous entity encompassing different phenotypes. Targeting single mediator or receptor did not prove much clinical significant, as asthma is complex disease involving myriad inflammatory mediators. Asthma may probably involve a large number of different types of molecular and cellular components interacting through complex pathophysiological pathways. This review covers the past, present, and future therapeutic approaches and pathophysiological mechanisms of asthma. Furthermore, review describe importance of targeting several mediators/modulators and receptor antagonists involved in the physiopathology of asthma. Novel targets for asthma research include Galectins, Immunological targets, K + Channels, Kinases and Transcription Factors, Toll-like receptors, Selectins and Transient receptor potential channels. But recent developments in asthma research are very promising, these include Bitter taste receptors (TAS2R) abated airway obstruction in mouse model of asthma and Calcium-sensing receptor obliterate inflammation and in bronchial hyperresponsiveness allergic asthma. All these progresses in asthma targets, and asthma phenotypes exploration are auspicious in untangling of asthma riddles.
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Affiliation(s)
- Jatinder Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, 147002, Punjab, India
| | - Ramanpreet Shah
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, 147002, Punjab, India
| | - Dhandeep Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, 147002, Punjab, India.
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12
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Gao Y, Chen T, Raj JU. Endothelial and Smooth Muscle Cell Interactions in the Pathobiology of Pulmonary Hypertension. Am J Respir Cell Mol Biol 2016; 54:451-60. [PMID: 26744837 DOI: 10.1165/rcmb.2015-0323tr] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In the pulmonary vasculature, the endothelial and smooth muscle cells are two key cell types that play a major role in the pathobiology of pulmonary vascular disease and pulmonary hypertension. The normal interactions between these two cell types are important for the homeostasis of the pulmonary circulation, and any aberrant interaction between them may lead to various disease states including pulmonary vascular remodeling and pulmonary hypertension. It is well recognized that the endothelial cell can regulate the function of the underlying smooth muscle cell by releasing various bioactive agents such as nitric oxide and endothelin-1. In addition to such paracrine regulation, other mechanisms exist by which there is cross-talk between these two cell types, including communication via the myoendothelial injunctions and information transfer via extracellular vesicles. Emerging evidence suggests that these nonparacrine mechanisms play an important role in the regulation of pulmonary vascular tone and the determination of cell phenotype and that they are critically involved in the pathobiology of pulmonary hypertension.
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Affiliation(s)
- Yuansheng Gao
- 1 Department of Physiology and Pathophysiology, Health Science Center, Peking University, Beijing, China; and
| | - Tianji Chen
- 2 Department of Pediatrics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - J Usha Raj
- 2 Department of Pediatrics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
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13
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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: 489] [Impact Index Per Article: 61.1] [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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14
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Duthie KM, Hadoke PWF, Kirkby NS, Miller E, Ivy JR, McShane JF, Lim WG, Webb DJ. Selective endothelin A receptor antagonism with sitaxentan reduces neointimal lesion size in a mouse model of intraluminal injury. Br J Pharmacol 2015; 172:2827-37. [PMID: 25598351 DOI: 10.1111/bph.13086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 12/08/2014] [Accepted: 01/03/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Endothelin (ET) receptor antagonism reduces neointimal lesion formation in animal models. This investigation addressed the hypothesis that the selective ETA receptor antagonist sitaxentan would be more effective than mixed ETA / B receptor antagonism at inhibiting neointimal proliferation in a mouse model of intraluminal injury. EXPERIMENTAL APPROACH Antagonism of ETA receptors by sitaxentan (1-100 nM) was assessed in femoral arteries isolated from adult, male C57Bl6 mice using isometric wire myography. Neointimal lesion development was induced by intraluminal injury in mice receiving sitaxentan (ETA antagonist; 15 mg·kg(-1) ·day(-1) ), A192621 (ETB antagonist; 30 mg·kg(-1) ·day(-1) ), the combination of both antagonists or vehicle. Treatment began 1 week before, and continued for 28 days after, surgery. Femoral arteries were then harvested for analysis of lesion size and composition. KEY RESULTS Sitaxentan produced a selective, concentration-dependent parallel rightward shift of ET-1-mediated contraction in isolated femoral arteries. Sitaxentan reduced neointimal lesion size, whereas ETB and combined ETA / B receptor antagonism did not. Macrophage and α-smooth muscle actin content were unaltered by ET receptor antagonism but sitaxentan reduced the amount of collagen in lesions. CONCLUSIONS AND IMPLICATIONS These results suggest that ETA receptor antagonism would be more effective than combined ETA /ETB receptor antagonism at reducing neointimal lesion formation.
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Affiliation(s)
- Karolina M Duthie
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Patrick W F Hadoke
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Nicholas S Kirkby
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Eileen Miller
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Jessica R Ivy
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - John F McShane
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Win Gel Lim
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - David J Webb
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
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15
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Abstract
Hypoxic pulmonary hypertension of the newborn is characterized by elevated pulmonary vascular resistance and pressure due to vascular remodeling and increased vessel tension secondary to chronic hypoxia during the fetal and newborn period. In comparison to the adult, the pulmonary vasculature of the fetus and the newborn undergoes tremendous developmental changes that increase susceptibility to a hypoxic insult. Substantial evidence indicates that chronic hypoxia alters the production and responsiveness of various vasoactive agents such as endothelium-derived nitric oxide, endothelin-1, prostanoids, platelet-activating factor, and reactive oxygen species, resulting in sustained vasoconstriction and vascular remodeling. These changes occur in most cell types within the vascular wall, particularly endothelial and smooth muscle cells. At the cellular level, suppressed nitric oxide-cGMP signaling and augmented RhoA-Rho kinase signaling appear to be critical to the development of hypoxic pulmonary hypertension of the newborn.
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Affiliation(s)
- Yuansheng Gao
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China
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16
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Role of κ—Opioid Receptor in Hypoxic Pulmonary Artery Hypertension and Its Underlying Mechanism. Am J Ther 2013; 20:329-36. [DOI: 10.1097/mjt.0b013e318249a08c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Endothelin(A)-endothelin(B) receptor cross talk in endothelin-1-induced contraction of smooth muscle. J Cardiovasc Pharmacol 2013; 60:483-94. [PMID: 22987051 DOI: 10.1097/fjc.0b013e31826f32c1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The efficacy of selective endothelin (ET) receptor antagonists may be limited by a functional interaction between the ET(A) and ET(B) receptors. This interaction, also termed "cross talk", is characterized by the dependency of the inhibition of an ET-1 response due to antagonism of one ET receptor subtype upon concomitant antagonism of the other ET receptor subtype. Although a reduction in ET(A)-ET(B) receptor cross talk would presumably increase the efficacy of selective ET receptor antagonists, an approach that accomplishes this aim is largely absent due to a lack of mechanistic understanding. Toward this goal, we evaluated the characteristics and potential dependencies of cross talk in smooth muscle. Smooth muscle was adopted as an exemplar not only because cross talk is widely reported in this tissue type, thereby allowing numerous comparisons, but also significant controversy surrounds the use of selective versus nonselective ET receptor antagonists in ET-1-related pathophysiologies involving smooth muscle. Based on this evaluation, we suggest that ET(A)-ET(B) receptor cross talk is a dynamic process directed by either or both ET receptor subtypes and expressed to varying magnitudes depending on the ET-1 and selective ET receptor antagonist concentrations, tone due to intraluminal pressure/stretch, agonists acting at receptors other than the ET(A)/ET(B) receptors, and endothelial/epithelial function. It is speculated that ET(A)-ET(B) receptor cross talk occurs through signal transduction pathways along with changes at the receptor level. Pharmacologic intervention of the signaling pathways could increase the therapeutic efficacy of ET receptor antagonists.
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18
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Rafikova O, Rafikov R, Kumar S, Sharma S, Aggarwal S, Schneider F, Jonigk D, Black SM, Tofovic SP. Bosentan inhibits oxidative and nitrosative stress and rescues occlusive pulmonary hypertension. Free Radic Biol Med 2013; 56:28-43. [PMID: 23200808 PMCID: PMC3749888 DOI: 10.1016/j.freeradbiomed.2012.09.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 08/17/2012] [Accepted: 09/13/2012] [Indexed: 02/07/2023]
Abstract
Pulmonary arterial hypertension (PH) is a fatal disease marked by excessive pulmonary vascular cell proliferation. Patients with idiopathic PH express endothelin-1 (ET-1) at high levels in their lungs. As the activation of both types of ET-1 receptor (ETA and ETB) leads to increased generation of superoxide and hydrogen peroxide, this may contribute to the severe oxidative stress found in PH patients. As a number of pathways may induce oxidative stress, the particular role of ET-1 remains unclear. The aim of this study was to determine whether inhibition of ET-1 signaling could reduce pulmonary oxidative stress and attenuate the progression of disease in rats with occlusive-angioproliferative PH induced by a single dose of SU5416 (200 mg/kg) and subsequent exposure to hypoxia for 21 days. Using this regimen, animals developed severe PH as evidenced by a progressive increase in right-ventricle (RV) peak systolic pressure (RVPSP), severe RV hypertrophy, and pulmonary endothelial and smooth muscle cell proliferation, resulting in plexiform vasculopathy. PH rats also had increased oxidative stress, correlating with endothelial nitric oxide synthase uncoupling and NADPH oxidase activation, leading to enhanced protein nitration and increases in markers of vascular remodeling. Treatment with the combined ET receptor antagonist bosentan (250 mg/kg/day; day 10 to 21) prevented further increase in RVPSP and RV hypertrophy, decreased ETA/ETB protein levels, reduced oxidative stress and protein nitration, and resulted in marked attenuation of pulmonary vascular cell proliferation. We conclude that inhibition of ET-1 signaling significantly attenuates the oxidative and nitrosative stress associated with PH and prevents its progression.
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Affiliation(s)
- Olga Rafikova
- Center for Clinical Pharmacology and Vascular Medicine Institute, Department of Medicine, Pittsburgh, PA 15260, USA
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Ruslan Rafikov
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Sanjiv Kumar
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Shruti Sharma
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Saurabh Aggarwal
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Frank Schneider
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Danny Jonigk
- Institute of Pathology, Hannover Medical School, 30625 Hannover, Germany
| | - Stephen M. Black
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Stevan P. Tofovic
- Center for Clinical Pharmacology and Vascular Medicine Institute, Department of Medicine, Pittsburgh, PA 15260, USA
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19
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Abstract
It has been known for more than 60 years, and suspected for over 100, that alveolar hypoxia causes pulmonary vasoconstriction by means of mechanisms local to the lung. For the last 20 years, it has been clear that the essential sensor, transduction, and effector mechanisms responsible for hypoxic pulmonary vasoconstriction (HPV) reside in the pulmonary arterial smooth muscle cell. The main focus of this review is the cellular and molecular work performed to clarify these intrinsic mechanisms and to determine how they are facilitated and inhibited by the extrinsic influences of other cells. Because the interaction of intrinsic and extrinsic mechanisms is likely to shape expression of HPV in vivo, we relate results obtained in cells to HPV in more intact preparations, such as intact and isolated lungs and isolated pulmonary vessels. Finally, we evaluate evidence regarding the contribution of HPV to the physiological and pathophysiological processes involved in the transition from fetal to neonatal life, pulmonary gas exchange, high-altitude pulmonary edema, and pulmonary hypertension. Although understanding of HPV has advanced significantly, major areas of ignorance and uncertainty await resolution.
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Affiliation(s)
- J. T. Sylvester
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
| | - Larissa A. Shimoda
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
| | - Philip I. Aaronson
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
| | - Jeremy P. T. Ward
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
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20
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Henno P, Boitiaux JF, Douvry B, Cazes A, Lévy M, Devillier P, Delclaux C, Israël-Biet D. Tobacco-associated pulmonary vascular dysfunction in smokers: role of the ET-1 pathway. Am J Physiol Lung Cell Mol Physiol 2011; 300:L831-9. [PMID: 21378026 DOI: 10.1152/ajplung.00251.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pulmonary vascular remodeling and dysfunction associated to tobacco smoking might pave the way for the subsequent development of pulmonary hypertension. Its prognosis is dreadful and its underlying mechanisms are so far largely unknown in humans. To assess the potential role of endothelin-1 and its receptors in smokers' pulmonary artery vasoactive properties. Endothelium-dependent vasodilation to ACh was assessed in pulmonary vascular rings from 34 smokers and compared with that of 10 nonsmokers. The effects of ET-A (BQ 123) or ET-B (BQ 788) blockers and that of an ET-B activator (sarafotoxin) were evaluated. Endothelin-1 was quantitated by ELISA. Expression of its receptors was quantitated by Western blotting. Smokers exhibited an impaired pulmonary endothelium-dependent vasodilation compared with nonsmokers (P < 0.01). In the former group, 8 of 34 subjects exhibited a marked endothelial dysfunction (ED(+)) whereas 26 (ED(-)) (P < 10(-4)) displayed a vasorelaxation to ACh that was comparable to that of nonsmokers. In ED(+) subjects, ET-A was overexpressed (P < 0.05) and inversely correlated (P < 10(-2)) with the response to ACh. Sarafotoxin significantly improved vasodilation in all subjects (P < 10(-2)). In conclusion, tobacco smoking is associated to an impaired pulmonary vasorelaxation at least partly mediated by an ET-1/ET-A-dependent dysfunction.
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Affiliation(s)
- Priscilla Henno
- Unité Propre de Recherche de l’Enseignement Supérieur EA, UFR Biomédicale des Saints Pères, Paris, France
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21
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Abstract
During the development of the pulmonary vasculature in the fetus, many structural and functional changes occur to prepare the lung for the transition to air breathing. The development of the pulmonary circulation is genetically controlled by an array of mitogenic factors in a temporo-spatial order. With advancing gestation, pulmonary vessels acquire increased vasoreactivity. The fetal pulmonary vasculature is exposed to a low oxygen tension environment that promotes high intrinsic myogenic tone and high vasocontractility. At birth, a dramatic reduction in pulmonary arterial pressure and resistance occurs with an increase in oxygen tension and blood flow. The striking hemodynamic differences in the pulmonary circulation of the fetus and newborn are regulated by various factors and vasoactive agents. Among them, nitric oxide, endothelin-1, and prostaglandin I2 are mainly derived from endothelial cells and exert their effects via cGMP, cAMP, and Rho kinase signaling pathways. Alterations in these signaling pathways may lead to vascular remodeling, high vasocontractility, and persistent pulmonary hypertension of the newborn.
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Affiliation(s)
- Yuansheng Gao
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China; and Department of Pediatrics, University of Illinois, College of Medicine at Chicago, Chicago, Illinois
| | - J. Usha Raj
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China; and Department of Pediatrics, University of Illinois, College of Medicine at Chicago, Chicago, Illinois
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MacIntyre IM, Dhaun N, Lilitkarntakul P, Melville V, Goddard J, Webb DJ. Greater Functional ET
B
Receptor Antagonism With Bosentan Than Sitaxsentan in Healthy Men. Hypertension 2010; 55:1406-11. [DOI: 10.1161/hypertensionaha.109.148569] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Iain M. MacIntyre
- From the Clinical Pharmacology Unit (I.M.M., N.D., P.L., V.M., D.J.W.), Centre for Cardiovascular Science, University of Edinburgh, The Queen’s Medical Research Institute, Edinburgh, United Kingdom; Department of Renal Medicine (J.G.), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Neeraj Dhaun
- From the Clinical Pharmacology Unit (I.M.M., N.D., P.L., V.M., D.J.W.), Centre for Cardiovascular Science, University of Edinburgh, The Queen’s Medical Research Institute, Edinburgh, United Kingdom; Department of Renal Medicine (J.G.), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Pajaree Lilitkarntakul
- From the Clinical Pharmacology Unit (I.M.M., N.D., P.L., V.M., D.J.W.), Centre for Cardiovascular Science, University of Edinburgh, The Queen’s Medical Research Institute, Edinburgh, United Kingdom; Department of Renal Medicine (J.G.), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Vanessa Melville
- From the Clinical Pharmacology Unit (I.M.M., N.D., P.L., V.M., D.J.W.), Centre for Cardiovascular Science, University of Edinburgh, The Queen’s Medical Research Institute, Edinburgh, United Kingdom; Department of Renal Medicine (J.G.), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Jane Goddard
- From the Clinical Pharmacology Unit (I.M.M., N.D., P.L., V.M., D.J.W.), Centre for Cardiovascular Science, University of Edinburgh, The Queen’s Medical Research Institute, Edinburgh, United Kingdom; Department of Renal Medicine (J.G.), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - David J. Webb
- From the Clinical Pharmacology Unit (I.M.M., N.D., P.L., V.M., D.J.W.), Centre for Cardiovascular Science, University of Edinburgh, The Queen’s Medical Research Institute, Edinburgh, United Kingdom; Department of Renal Medicine (J.G.), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
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23
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Reesink HJ, Surie S, Kloek JJ, Tan HL, Tepaske R, Fedullo PF, Bresser P. Bosentan as a bridge to pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. J Thorac Cardiovasc Surg 2010; 139:85-91. [PMID: 19660388 DOI: 10.1016/j.jtcvs.2009.03.053] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Revised: 03/23/2009] [Accepted: 03/29/2009] [Indexed: 11/26/2022]
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24
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Pullamsetti SS, Schermuly RT. Endothelin receptor antagonists in preclinical models of pulmonary hypertension. Eur J Clin Invest 2009; 39 Suppl 2:3-13. [PMID: 19335741 DOI: 10.1111/j.1365-2362.2009.02115.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Pulmonary hypertension (PH), a chronic disorder of the pulmonary vasculature, is characterized by progressive elevation in pulmonary artery pressure and the ultimate development of right-sided heart failure and death. Being a rapidly progressive disease with limited therapeutic options, the pathogenesis of PH is complex and multifactorial. The pathogenesis may result from a combination of vasoconstriction, inward vascular wall remodelling and in situ thrombosis that involves dysfunction of underlying cellular pathways and mediators. Among these, the activation of endothelin (ET) system has been shown to be important in the development and perpetuation of PH. Endothelin-1 (ET-1), a potent vasoconstrictor and mitogen, exerts its biological effects by binding to two G-protein-coupled receptor isoforms, endothelin A (ETA) receptor and endothelin B (ETB) receptor. These two receptors are nonredundant and unique because of distinct localization, unique binding locations and affinities for the endothelin peptide and activation of distinct signalling pathways. Importantly, there is now substantial evidence that direct antagonism of ET receptors that can block either ETA- or ETA- and ETB receptors can be beneficial for the treatment of PH in both preclinical and clinical setting. This review provides an overview of endothelin biology, various preclinical models that have been widely used to investigate the pathophysiology of PH as well as the individual roles of the ET receptors (ETA and ETB) and their regulation in disease pathogenesis. We also review current data on the use of selective and nonselective ET receptor antagonism in the preclinical PH models.
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25
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Steiner MK, Preston IR. Optimizing endothelin receptor antagonist use in the management of pulmonary arterial hypertension. Vasc Health Risk Manag 2009; 4:943-52. [PMID: 19183742 PMCID: PMC2605321 DOI: 10.2147/vhrm.s2270] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Endothelin receptor antagonism has emerged as an important therapeutic approach in pulmonary arterial hypertension (PAH). Bench to bedside scientific research has shown that endothelin-1 (ET-1) is overexpressed in several forms of pulmonary vascular disease and may play an important pathogenetic role in the development and progression of PAH. Oral endothelin receptor antagonists (ERAs) improved exercise capacity, functional status, pulmonary hemodymanics, and delayed the time to clinical worsening in several randomized placebo-controlled trials. Two ERAs are currently approved by the US Food and Drug Administration: bosentan, a dual ERA for patients with class III and IV PAH, and ambrisentan, a selective ERA for patients with class II and III PAH. Sitaxsentan, another selective ERA, has been approved in Europe, Canada, and Australia. The objective of this review is to evaluate the available evidence describing the pharmacology, efficacy, safety, and tolerability, and patient-focused perspectives regarding the different types of endothelin receptor antagonists. Ongoing and forthcoming randomized trials are also highlighted including the approach of combining this class of drugs with other drugs that target different cellular pathways believed to be etiologically important in PAH.
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Affiliation(s)
- M Kathryn Steiner
- Pulmonary Critical Care Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
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26
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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: 31] [Impact Index Per Article: 1.8] [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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27
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Chester AH, Azam R, Felkin LE, George R, Brand N. Correlation between vascular responsivensss and expression of novel transcripts of the ETA-receptor in human vascular tissue. Vascul Pharmacol 2007; 46:181-7. [PMID: 17126612 DOI: 10.1016/j.vph.2006.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2006] [Revised: 09/01/2006] [Accepted: 09/26/2006] [Indexed: 11/26/2022]
Abstract
Alternatively spliced endothelin (ET-1) receptor transcripts have been identified, but their significance to the functional effects of ET-1 has not been established. We have investigated the presence and influence of alternatively spliced ET(A) receptor transcripts on ET-1 mediated contraction of segments of human saphenous vein. The expression of ET(A) receptor transcripts was examined with quantitative reverse transcription-polymerase chain reaction (qPCR) studies, while the response of veins to ET-1 was tested with in vitro organ bath techniques. The expression of four different transcripts for the ET(A) receptor, in which either exon 3 is spliced out (Delta3), exon 4 is spliced out (Delta4), both 3 and 4 spliced out (Delta3,4) and when both exons 2 and 4 (Delta2,4) are spliced out were identified. Functional studies showed that a lack of efficacy and potency of ET-1 is associated with a significantly lower expression of the Delta3,4 transcript. ET(A) receptor antagonism was insurmountable in samples that had lower levels of the Delta3,4 transcript, while samples from patients with higher expression of the Delta3,4 showed surmountable antagonism with BQ123. These results suggest that there is a genetic basis for the variability between individuals for the contractile effect of ET-1 at ET(A) receptors.
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Affiliation(s)
- Adrian H Chester
- Imperial College London, Heart Science Centre, Harefield Hospital, Harefield, Middlesex, UB9 6JH, United Kingdom.
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28
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Rondelet B, Kerbaul F, Vivian GF, Hubloue I, Huez S, Fesler P, Remmelink M, Brimiouille S, Salmon I, Naeije R. Sitaxsentan for the prevention of experimental shunt-induced pulmonary hypertension. Pediatr Res 2007; 61:284-8. [PMID: 17314684 DOI: 10.1203/pdr.0b013e318030d169] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We previously reported on the partial prevention of experimental shunt-induced pulmonary arterial hypertension (PAH) by the nonselective endothelin (ET) ET-A/ET-B receptor antagonist bosentan. As the respective roles of the ET-A and ET-B receptor signaling in the pathobiology of the disease remain undefined, we investigated the effects of selective ET-A receptor blockade by sitaxsentan in the same early stage PAH model. Twenty-one 3-wk-old piglets were randomized to placebo or sitaxsentan therapy (1.5 mg/kg/d), after anastomosis of the left subclavian artery to the pulmonary arterial trunk or after a sham operation. Three months later, the animals underwent a hemodynamic evaluation, followed by pulmonary tissue sampling for morphometry and real-time-quantitative-PCR for ET-1, angiopoietin-1, and bone morphogenetic receptor (BMPR) signaling molecules. Three months of left to right shunting induced an increase in pulmonary vascular resistance (PVR) and medial thickness, an overexpression of ET-1, ET-B receptor, and angiopoietin-1, and a decreased expression of BMPR-2 and BMPR-1A. Pretreatment with sitaxsentan prevented shunt-induced increase in PVR and decreased medial thickness by 64%. Sitaxsentan therapy completely prevented the decreased expression of BMPR-2 and limited the overexpression of ET-1, ET-B and angiopoietin-1, and the decreased expression of BMPR-1A. In conclusion, selective ET-A receptor blockade partially prevents shunt-induced PAH.
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Affiliation(s)
- Benoit Rondelet
- Laboratory of Physiology, Department of Cardiac Surgery, Hôpital Erasme, Université Libre de B-1070 Bruxelles, Belgium.
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29
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Abstract
In humans, the endothelins (ETs) comprise a family of three 21-amino-acid peptides, ET-1, ET-2 and ET-3. ET-1 is synthesised from a biologically inactive precursor, Big ET-1, by an unusual hydrolysis of the Trp21 -Val22 bond by the endothelin converting enzyme (ECE-1). In humans, there are four isoforms (ECE-1a-d) derived from a single gene by the action of alternative promoters. Structurally, they differ only in the amino acid sequence of the extreme N-terminus. A second enzyme, ECE-2, also exists as four isoforms and differs from ECE-1 in requiring an acidic pH for optimal activity. Human chymase can also cleave Big ET-1 to ET-1, which is cleaved, in turn, to the mature peptide as an alternative pathway. ET-1 is the principal isoform in the human cardiovascular system and remains one of the most potent constrictors of human vessels discovered. ET-1 is unusual in being released from a dual secretory pathway. The peptide is continuously released from vascular endothelial cells by the constitutive pathway, producing intense constriction of the underlying smooth muscle and contributing to the maintenance of endogenous vascular tone. ET-1 is also released from endothelial cell-specific storage granules (Weibel-Palade bodies) in response to external stimuli. ETs mediate their action by activating two G protein-coupled receptor sub-types, ETA and ET(B). Two therapeutic strategies have emerged to oppose the actions of ET-1, namely inhibition of the synthetic enzyme by combined ECE/neutral endopeptidase inhibitors such as SLV306, and receptor antagonists such as bosentan. The ET system is up-regulated in atherosclerosis, and ET antagonists may be of benefit in reducing blood pressure in essential hypertension. Bosentan, the first ET antagonist approved for clinical use, represents a significant new therapeutic strategy in the treatment of pulmonary arterial hypertension (PAH).
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Affiliation(s)
- A P Davenport
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK.
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30
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Opitz CF, Ewert R. Dual ET(A)/ET(B) vs. selective ET(A) endothelin receptor antagonism in patients with pulmonary hypertension. Eur J Clin Invest 2006; 36 Suppl 3:1-9. [PMID: 16919004 DOI: 10.1111/j.1365-2362.2006.01691.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Since the identification of endothelin as a key mediator in the pathogenesis of several diseases, including pulmonary arterial hypertension (PAH), the pharmacologic control of the activated endothelin system with endothelin receptor antagonists (ETRA) has been a major therapeutic achievement for the treatment of patients with PAH. To date, dual ET(A)/ET(B) and selective ET(A) receptor antagonists have clinically been evaluated. To answer the question of whether selective or dual ETRA is preferable in patients with PAH, experimental and clinical data with relevance to the pulmonary circulation are reviewed in this article. Whereas experimental and clinical data provide unambiguous evidence that ET(A) receptors mediate the detrimental effects of ET-1, such as vasoconstriction and cell proliferation, the elucidation of the role of ET(B) receptors has been more complex. It has been shown that there is a subpopulation of ET(B) receptors on smooth muscle cells and fibroblasts mediating vasoconstriction and proliferation. On the contrary, there is clear evidence that endothelial ET(B) receptors continue to mediate vasodilation, vasoprotection and ET-1 clearance despite the pathology associated with pulmonary hypertension. More difficult to assess is the net effect of these mechanisms in patients to be treated with ETRA. When considering the available data from controlled clinical trials, nonselectivity does not appear to carry a relevant clinical benefit for the treatment of patients with PAH when compared with selective ET(A) receptor antagonism.
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Affiliation(s)
- C F Opitz
- Medizinische Klinik II, DRK-Kliniken Berlin, Westend, Berlin, Germany.
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31
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Reesink HJ, Kloek JJ, Bresser P. Chronic thromboembolic pulmonary hypertension. Neth Heart J 2006; 14:219-224. [PMID: 25696637 PMCID: PMC2557259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
Chronic thromboembolic pulmonary hypertension (CTEPH) is a rapidly progressive and deadly disease, resulting from incomplete resolution of acute pulmonary embolism. Historically, the incidence of CTEPH was significantly underestimated but it may be as high as 3.8% following acute pulmonary embolism. Although the medical management of CTEPH may be supportive, the only curative treatment is pulmonary endarterectomy (PEA). However, a careful screening programme is mandatory to select CTEPH patients who are likely to benefit from PEA. In this review we discuss the pathophysiology, clinical and diagnostic pitfalls, surgical treatment, outcome after surgery, and the potential benefit of medical treatment in inoperable CTEPH patients.
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32
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Dandel M, Lehmkuhl HB, Hetzer R. Advances in the Medical Treatment of Pulmonary Hypertension. Kidney Blood Press Res 2006; 28:311-24. [PMID: 16534227 DOI: 10.1159/000090186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Increased pulmonary precapillary vascular resistance due to vasoconstriction and vasoproliferative processes is the basic pathophysiological mechanism in the development of pulmonary hypertension (PH). With the exception of pulmonary venous hypertension, where the primary cause of PH is left ventricular failure or mitral valvular disease, all the other PH categories will benefit to a greater or lesser extent from pulmonary vasodilator and antivasoproliferative therapy. Today, for this purpose, in addition to intravenous prostacyclin (epoprostenol), which is restricted to severe pulmonary arterial hypertension (NYHA class IV and late class III), other therapeutic options such as treatment with more stable prostacyclin analogs (oral beraprost, aerosolized iloprost), endothelin-receptor antagonists (bosentan) or phosphodiesterase inhibitors (sildenafil) are also available and these are especially useful for the treatment of the early stages of the disease. The recent progress in medical therapy has markedly increased the life expectancy in patients with pulmonary arterial hypertension and substantially improved their quality of life. Chronic hemodialysis (HD) patients show higher endothelin-1 (ET-1) activity in comparison to healthy individuals and there is evidence that the increase of pulmonary vascular resistance in these patients is at least in part mediated by ET-1. Recent data show good results after PH therapy with the endothelin-receptor antagonist bosentan in HD patients. Also prostacyclin and its analogs, as well as phosphodiesterase inhibitors, can be useful for the treatment of pulmonary hypertension in patients with chronic renal failure.
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Affiliation(s)
- Michael Dandel
- Deutsches Herzzentrum Berlin, Department of Cardiothoracic and Vascular Surgery, Berlin, Germany.
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33
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Reesink HJ, Meijer RC, Lutter R, Boomsma F, Jansen HM, Kloek JJ, Bresser P. Hemodynamic and Clinical Correlates of Endothelin-1 in Chronic Thromboembolic Pulmonary Hypertension. Circ J 2006; 70:1058-63. [PMID: 16864942 DOI: 10.1253/circj.70.1058] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND In non-thromboembolic pulmonary hypertension, endothelin (ET)-1 levels are increased and correlate with the hemodynamic severity of the disease. Whether such correlations exist in chronic thromboembolic pulmonary hypertension (CTEPH) is unknown, nor whether ET-1 levels correlate with hemodynamic outcome after pulmonary endarterectomy (PEA). METHODS AND RESULTS ET-1 levels were determined by ELISA. ET-levels were increased in 35 CTEPH patients (1.62+/-0.21 pg/ml) compared with healthy controls (n=11: 0.75+/-0.06 pg/ml, p<0.02). ET-1 levels correlated (all p<0.0001) with mean pulmonary artery pressure (mPAP) (r=0.70), cardiac index (r=-0.76), total pulmonary resistance (r=0.72), mixed venous oxygen saturation (r=-0.87), and the distance walked in the 6-min walk test (r=-0.59; p<0.005; n=23). Three months after PEA, ET-1 levels had decreased (p<0.002), and were similar between patients with and without residual pulmonary hypertension (p=0.4). Preoperative ET-1 levels, however, were higher in patients with bad postoperative outcome; that is, patients who either died because of persistent pulmonary hypertension or had residual pulmonary hypertension after PEA (2.68+/-0.48 pg/ml, and 1.13+/-0.15 pg/ml, respectively; p<0.002). The levels also correlated with hemodynamic outcome after PEA (mPAP: r=0.67, p<0.0001). By receiver-operator characteristic curve analysis, ET-1>1.77 pg/ml detected a bad postoperative outcome with a sensitivity and specificity of 79% and 85%, respectively, and a likelihood ratio of 5.2. CONCLUSION ET-1 levels in CTEPH closely correlated with the hemodynamic and clinical severity of disease in a large cohort of patients. Preoperative ET-1 levels may be useful for better identification of patients at risk for persistent pulmonary hypertension after PEA.
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Affiliation(s)
- Herre J Reesink
- Department of Pulmonology, University of Amsterdam, The Netherlands
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34
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Fujimoto K, Ikenoya S. [Pharmacological characteristics and clinical efficacy of bosentan]. Nihon Yakurigaku Zasshi 2005; 126:407-18. [PMID: 16462092 DOI: 10.1254/fpj.126.407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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35
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Wang X, Tong M, Chinta S, Raj JU, Gao Y. Hypoxia-induced reactive oxygen species downregulate ETB receptor-mediated contraction of rat pulmonary arteries. Am J Physiol Lung Cell Mol Physiol 2005; 290:L570-8. [PMID: 16227321 DOI: 10.1152/ajplung.00262.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Production of reactive oxygen species (ROS) may be increased during hypoxia in pulmonary arteries. In this study, the role of ROS in the effect of hypoxia on endothelin (ET) type B (ETB) receptor-mediated vasocontraction in lungs was determined. In rat intrapulmonary (approximately 0.63 mm ID) arteries, contraction induced by IRL-1620 (a selective ETB receptor agonist) was significantly attenuated after 4 h of hypoxia (30 mmHg Po2) compared with normoxic control (140 mmHg Po2). The effect was abolished by tiron, a scavenger of superoxide anions, but not by polyethylene glycol (PEG)-conjugated catalase, which scavenges H2O2. The hypoxic effect on ETB receptor-mediated vasoconstriction was also abolished by endothelium denudation but not by nitro-L-arginine and indomethacin. Exposure for 4 h to exogenous superoxide anions, but not H2O2, attenuated the vasoconstriction induced by IRL-1620. Confocal study showed that hypoxia increased ROS production in pulmonary arteries that were scavenged by PEG-conjugated SOD. In endothelium-intact pulmonary arteries, the ETB receptor protein was reduced after 4 h of exposure to hypoxia, exogenous superoxide anions, or ET-1. BQ-788, a selective ETB receptor antagonist, prevented these effects. ET-1 production was stimulated in endothelium-intact arteries after 4 h of exposure to hypoxia or exogenous superoxide anions. This effect was blunted by PEG-conjugated SOD. These results demonstrate that exposure to hypoxia attenuates ETB receptor-mediated contraction of rat pulmonary arteries. A hypoxia-induced production of superoxide anions may increase ET-1 release from the endothelium and result in downregulation of ETB receptors on smooth muscle.
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Affiliation(s)
- Xiaohua Wang
- Dept. of Physiology and Pathophysiology, Peking Univ. Health Science Center, 38 Xue Yuan Rd., Beijing 100083, China
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36
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Maguire JJ, Davenport AP. The therapeutic potential of PD156707 and related butenolide endothelin antagonists. Expert Opin Investig Drugs 2005; 8:71-8. [PMID: 15992060 DOI: 10.1517/13543784.8.1.71] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Plasma concentrations of the peptide endothelin (ET) are elevated in several cardiovascular diseases. Animal studies suggest that activation of ET receptors may contribute to the increase in vascular resistance and remodelling of cardiovascular tissues that are characteristic of these pathologies. Antagonists of these receptors may therefore have important clinical potential. PD156707 (Parke-Davis) is one of a series of novel, orally-active butenolide endothelin antagonists and is highly selective for the ETA receptor. In man, this subtype mediates the profound vasoconstrictor effects of the ET peptides, and blockade of the ETA receptor may therefore produce beneficial vasodilatation. The advantage of selective ETA receptor antagonism is that it leaves unaffected vascular ETB receptors, which mediate vasorelaxation, and non-vascular ETB receptors, particularly in the lung and kidneys, which act to clear ET from the plasma. PD156707 exhibits subnanomolar affinity and greater than 1000-fold selectivity for human ETA receptors and potently inhibits ET-1-mediated vasoconstriction in human isolated blood vessels. In rats, PD156707 has good oral bioavailability (41%) and a relatively short terminal t1/2 of approximately 1 h. Structural analogues of PD156707 that have comparable selectivity and potency for the ETA receptor are reported to have even better oral bioavailability and longer plasma t1/2 values. Preclinical studies with PD156707 indicate efficacy in animal models of congestive heart failure (CHF), pulmonary hypertension (PH) and cerebral ischaemia. We await data from clinical trials to confirm the therapeutic potential of the ETA-selective butenolide antagonists in man.
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Affiliation(s)
- J J Maguire
- Clinical Pharmacology Unit, Level 6, Centre for Clinical Investigation, Addenbrooke's Hospital, Box 110, Cambridge, CB2 2QQ, UK.
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37
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de Lagausie P, de Buys-Roessingh A, Ferkdadji L, Saada J, Aisenfisz S, Martinez-Vinson C, Fund X, Cayuela JM, Peuchmaur M, Mercier JC, Berrebi D. Endothelin receptor expression in human lungs of newborns with congenital diaphragmatic hernia. J Pathol 2005; 205:112-8. [PMID: 15546126 DOI: 10.1002/path.1677] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Congenital diaphragmatic hernia (CDH) is a major cause of refractory respiratory failure in the neonatal period and is characterized by persistent pulmonary hypertension of the newborn (PPHN) and pulmonary hypoplasia. Endothelin-1 (ET-1) dysregulation may play a significant role in the pathophysiology of PPHN and ET-1 acts through binding to type A (ETA) and type B (ETB) receptors. Therefore, ETA and ETB receptor protein expression was studied using immunohistochemistry in 10 lung specimens obtained from newborns with CDH, and 4 normal lung specimens, in order to explore whether dysregulation of ETA and ETB expression contributes to PPHN. ETA and ETB mRNAs were then quantified using real-time RT-PCR in laser-microdissected pulmonary resistive arteries. In the lungs of newborns with CDH, immunohistochemistry of both ETA and ETB receptors demonstrated over-expression in the thickened media of pulmonary arteries. Using laser microdissection and real-time RT-PCR, higher levels of ETA and ETB mRNA were found in CDH pulmonary arteries than in controls: this increase was more pronounced for ETA mRNA. This study provides the first demonstration of ET-1 receptor dysregulation in association with structural alteration of pulmonary arteries in newborns with CDH and PPHN. This dysregulation preferentially affects the ETA receptor. These results suggest that dysregulation of ET-1 receptors may contribute to PPHN associated with CDH.
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MESH Headings
- Body Weight
- Female
- Gene Expression
- Hernia, Diaphragmatic/complications
- Hernia, Diaphragmatic/metabolism
- Hernia, Diaphragmatic/pathology
- Hernias, Diaphragmatic, Congenital
- Humans
- Infant, Newborn
- Lung/metabolism
- Lung/pathology
- Male
- Microdissection/methods
- Organ Size
- Persistent Fetal Circulation Syndrome/etiology
- Persistent Fetal Circulation Syndrome/metabolism
- Persistent Fetal Circulation Syndrome/pathology
- Pulmonary Artery/metabolism
- RNA, Messenger/genetics
- Receptor, Endothelin A/genetics
- Receptor, Endothelin A/metabolism
- Receptor, Endothelin B/genetics
- Receptor, Endothelin B/metabolism
- Receptors, Endothelin/metabolism
- Retrospective Studies
- Reverse Transcriptase Polymerase Chain Reaction
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38
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Staniloae C, Dupuis J, White M, Gosselin G, Dyrda I, Bois M, Crépeau J, Bonan R, Caron A, Lavoie J. Reduced pulmonary clearance of endothelin in congestive heart failure: a marker of secondary pulmonary hypertension. J Card Fail 2004; 10:427-32. [PMID: 15470654 DOI: 10.1016/j.cardfail.2004.01.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Endothelin-1 (ET-1) levels are elevated in congestive heart failure (CHF) in relation with the severity of pulmonary hypertension. We evaluated whether a reduced pulmonary ET-1 clearance could contribute to this elevation. METHODS AND RESULTS We determined pulmonary ET-1 clearance in 24 patients with CHF in relation with hemodynamics, plasma ET-1, and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Pulmonary ET-1 extraction, measured by the single bolus indicator-dilution technique, was reduced to 32 +/- 14% in comparison to historic controls (47 +/- 7%). Plasma ET-1 clearance by the lungs (924 +/- 588 mL/min) was also much lower than in controls (1424 +/- 79 mL/min). Clearance correlated inversely with mean pulmonary artery pressure (PAP, r = -.47, P = .017) and pulmonary capillary wedge pressure (r = -.47, P = .017) and positively with the rate of left ventricular (LV) relaxation LV -dP/dt (r = .593, P = .004). After multivariate analysis, only mean PAP and LV -dP/dt were independently correlated with ET-1 clearance (r = -.40, P = .03, and r = .55, P = .005, respectively). Plasma ET-1 levels did not correlate with clearance (r = .038, P = .86), and there was no significant arteriovenous ET-1 gradient. There was a mild nonsignificant correlation between plasma ET-1 and pulmonary artery systolic pressure (r = .38, P = .06), but a strong correlation with right atrial pressure (r = .696, P < .0001) and NT-proBNP levels (r = .51, P = .001), which were maintained after multivariate linear regression (r = .60, P = .001, and r = .32, P = .04, respectively). CONCLUSION Pulmonary ET-1 clearance is reduced in CHF in relation with the severity of pulmonary hypertension. This reduced clearance does not significantly modulate plasma ET-1 levels. Whether this is only a marker of secondary pulmonary hypertension or could modulate pulmonary vascular tone will require further studies.
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Affiliation(s)
- Cezar Staniloae
- Department of Medicine, Montreal Heart Institute, Quebec, Canada
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39
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Nishida M, Okada Y, Akiyoshi K, Eshiro K, Takoaka M, Gariepy CE, Yanagisawa M, Matsumura Y. Role of endothelin ETB receptor in the pathogenesis of monocrotaline-induced pulmonary hypertension in rats. Eur J Pharmacol 2004; 496:159-65. [PMID: 15359489 DOI: 10.1016/j.ejphar.2004.06.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We investigated the role of endothelin ETB receptor in the development of monocrotaline-induced pulmonary hypertension, by using the spotting-lethal (sl) rat, which carries a naturally occurring deletion in the endothelin ETB receptor gene. Three weeks after injection of saline or monocrotaline (60 mg/kg, s.c.), hemodynamics, cardiac hypertrophy and endothelin-1 levels in right ventricle were determined. Monocrotaline produced a marked pulmonary hypertension associated with increases in right ventricular pressure and hypertrophy, pulmonary arterial medial thickening and the endothelin-1 levels. The monocrotaline-induced alterations tended to be enhanced in ETB-deficient homozygous rats, compared with cases in wild-type rats. The treatment with selective ETA receptor antagonist ABT-627 [2R-(4-methoxyphenyl)-4S-(1,3-benzodioxol-5-yl)-1-(N,N-di(n-butyl)aminocarbonyl-methyl)-pyrrolidine-3R-carboxylic acid] for 3 weeks (10 mg/kg/day, twice daily) almost completely suppressed the monocrotaline-induced pulmonary hypertension and related organ damage both in ETB-deficient and wild-type animals to the same levels. Thus, we suggest that the antagonism of the ETA receptor is essential for the protection from monocrotaline-induced pulmonary hypertension, irrespective of the presence of the ETB receptors, although a protective role of ETB receptor-mediated action in the pathogenesis of this disease model cannot be ruled out.
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Affiliation(s)
- Masahiro Nishida
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Tatasuki, Japan
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40
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Nishida M, Eshiro K, Okada Y, Takaoka M, Matsumura Y. Roles of Endothelin ETA and ETB Receptors in the Pathogenesis of Monocrotaline-Induced Pulmonary Hypertension. J Cardiovasc Pharmacol 2004; 44:187-91. [PMID: 15243299 DOI: 10.1097/00005344-200408000-00007] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The functional roles of endothelin ETA and ETB receptors in the development of monocrotaline (MCT)-induced pulmonary hypertension were investigated using MCT-treated rats in the absence or presence of a daily administration of A-192621, a selective ETB receptor antagonist, ABT-627, a selective ETA receptor antagonist, or a combination of both drugs. Four weeks after the injection of saline or MCT (60 mg/kg, s.c.), cardiac hypertrophy, right ventricular systolic pressure and morphologic changes of pulmonary arteries were evaluated. Compared with the control animals, MCT produced marked pulmonary hypertension associated with increases in right ventricular pressure and hypertrophy, and pulmonary arterial medial thickening. These MCT-induced alterations were markedly suppressed by daily treatment with ABT-627 for 4 weeks (10 mg/kg/d, twice daily), whereas treatment with A-192621 significantly aggravated the above MCT-induced pathologic changes. The blockade of both receptor subtypes by a combination of A-192621 and ABT-627 also significantly improved the MCT-induced pathologic changes, to the same extent as with ABT-627 administration. Thus, an exaggerated response to MCT during ETB receptor blockade also seems to be mediated by ETA receptor activation, thereby suggesting that ETA receptor-mediated action is exclusively contributive to the pathogenesis of MCT-induced pulmonary hypertension, although we cannot rule out a protective role of ETB receptor-mediated action.
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MESH Headings
- Administration, Oral
- Animals
- Atrasentan
- Blood Pressure/drug effects
- Body Mass Index
- Body Weight/drug effects
- Cardiomegaly/chemically induced
- Cardiomegaly/complications
- Cardiomegaly/physiopathology
- Drug Administration Schedule
- Drug Therapy, Combination
- Heart/anatomy & histology
- Heart/drug effects
- Hypertension, Pulmonary/etiology
- Hypertrophy, Right Ventricular/chemically induced
- Hypertrophy, Right Ventricular/drug therapy
- Injections, Subcutaneous
- Intubation, Gastrointestinal
- Lung/anatomy & histology
- Lung/blood supply
- Male
- Monocrotaline/administration & dosage
- Monocrotaline/adverse effects
- Organ Size/drug effects
- Pulmonary Artery/anatomy & histology
- Pulmonary Artery/drug effects
- Pulmonary Artery/pathology
- Pyrrolidines/administration & dosage
- Pyrrolidines/adverse effects
- Pyrrolidines/pharmacokinetics
- Pyrrolidines/therapeutic use
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin A/physiology
- Receptor, Endothelin B/physiology
- Time Factors
- Tunica Media/drug effects
- Tunica Media/pathology
- Ventricular Pressure/drug effects
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Affiliation(s)
- Masahiro Nishida
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan
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41
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Abstract
The endothelin (ET) system is comprised of 4 active ETs, with ET-1 being the predominant isoform in the cardiovascular system. Because of the potent vasoconstricting and mitogenic effects of ET-1 and its involvement in various cardiovascular diseases, blockade of the ET receptor has received considerable attention. ET receptor antagonism has been demonstrated to be beneficial in patients with pulmonary hypertension. The nonselective ET receptor antagonist bosentan improves exercise capacity and increases time to clinical worsening in patients with pulmonary arterial hypertension. The selective ET A receptor antagonist sitaxsentan also improves hemodynamics and exercise capacity in patients with pulmonary arterial hypertension. Results with ET receptor antagonists in congestive heart failure have been disappointing. Although some studies have suggested benefit, larger studies have been neutral. The use of ET receptor antagonists for other conditions has not been fully explored. Future studies with the use of ET receptor antagonists as part of a multidrug regimen are also needed.
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Affiliation(s)
- Stuart Rich
- Rush Heart Institute Center for Pulmonary Heart Disease, Rush Medical College, Chicago, Ill, USA.
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42
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Black SM, Mata-Greenwood E, Dettman RW, Ovadia B, Fitzgerald RK, Reinhartz O, Thelitz S, Steinhorn RH, Gerrets R, Hendricks-Munoz K, Ross GA, Bekker JM, Johengen MJ, Fineman JR. Emergence of smooth muscle cell endothelin B-mediated vasoconstriction in lambs with experimental congenital heart disease and increased pulmonary blood flow. Circulation 2003; 108:1646-54. [PMID: 12963646 DOI: 10.1161/01.cir.0000087596.01416.2f] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Endothelin-1 (ET-1) has been implicated in the pathophysiology of pulmonary hypertension. In 1-month-old lambs with increased pulmonary blood flow, we have demonstrated early alterations in the ET-1 cascade. The objective of this study was to investigate the role of potential later alterations of the ET cascade in the pathophysiology of pulmonary hypertension secondary to increased pulmonary blood flow. METHODS AND RESULTS Eighteen fetal lambs underwent in utero placement of an aortopulmonary vascular graft (shunt) and were studied 8 weeks after spontaneous delivery. Compared with age-matched control lambs, lung tissue ET-1 levels were increased in shunt lambs (317.2+/-113.8 versus 209.8+/-61.8 pg/g, P<0.05). In shunt lambs (n=9), exogenous ET-1 induced potent pulmonary vasoconstriction, which was blocked by the ETA receptor antagonist PD 156707 (n=3). This pulmonary vasoconstriction was mimicked by exogenous Ala1,3,11,15 ET-1 (4 Ala ET-1), the ETB receptor agonist, and was blocked by the ETB receptor antagonist BQ 788 (n=3). However, in control lambs (n=7), ET-1 and 4 Ala ET-1 did not change pulmonary vascular tone. In contrast to 4-week-old shunt lambs, immunohistochemistry revealed the emergence of ETB receptors on smooth muscle cells in the vasculature of 8-week-old shunt lambs. CONCLUSIONS Over time, increased pulmonary blood flow and/or pressure results in the emergence of ETB-mediated vasoconstriction, which coincides with the emergence of ETB receptors on smooth muscle cells. These data suggest an important role for ETB receptors in the pathophysiology of pulmonary hypertension in this animal model of increased pulmonary blood flow.
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MESH Headings
- Animals
- Dioxoles/pharmacology
- Endothelin Receptor Antagonists
- Endothelin-1/metabolism
- Endothelin-1/pharmacology
- Endothelins/pharmacology
- Heart Defects, Congenital/complications
- Hemodynamics
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/physiopathology
- Lung/metabolism
- Muscle, Smooth, Vascular/chemistry
- Oligopeptides/pharmacology
- Piperidines/pharmacology
- Pulmonary Circulation
- Receptor, Endothelin A
- Receptor, Endothelin B
- Receptors, Endothelin/agonists
- Receptors, Endothelin/analysis
- Receptors, Endothelin/metabolism
- Receptors, Endothelin/physiology
- Sheep
- Vasoconstriction
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Affiliation(s)
- Stephen M Black
- Department of Pediatrics, Northwestern University, Chicago, Ill, USA
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43
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Michel RP, Langleben D, Dupuis J. The endothelin system in pulmonary hypertension. Can J Physiol Pharmacol 2003; 81:542-54. [PMID: 12839266 DOI: 10.1139/y03-008] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pulmonary hypertension (PH) may result from numerous clinical entities affecting the pulmonary circulation primarily or secondarily. It is recognized that vascular endothelial dysfunction contributes to the development and perpetuation of PH by creating an imbalance between vasodilating and antiproliferative forces and between vasoconstrictive and proliferative forces. In that context, endothelin-1 (ET-1) overproduction was rapidly targeted as a plausible contributor to the pathogenesis of PH. The lung is recognized as the major site for ET production and clearance. In all animal models of PH studied, circulating plasma ET-1 levels are elevated, accompanied by an increase in lung tissue expression of the peptide. The use of selective ETA and dual ETA-ETB receptor antagonists in these models both in prevention and in therapeutic studies have confirmed the contribution of ET-1 to the rise in pulmonary vascular tone, pulmonary medial hypertrophy, and right ventricular hypertrophy. This is found consistently in models affecting the pulmonary circulation primarily or producing PH secondarily. Recent clinical trials in patients with pulmonary arterial hypertension have confirmed the therapeutic effectiveness of ET-receptor antagonists in humans. We offer a systematic review of the pathogenic role of the ET system in the development of PH as well as the rationale behind the preclinical and ongoing clinical trials with this new class of agents.
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Affiliation(s)
- René P Michel
- Department of Pathology, McGill University Health Center, Montreal, QC, Canada
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44
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Mayes MD. Endothelin and endothelin receptor antagonists in systemic rheumatic disease. ARTHRITIS AND RHEUMATISM 2003; 48:1190-9. [PMID: 12746891 DOI: 10.1002/art.10895] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Maureen D Mayes
- University of Texas Health Science Center at Houston, TX, USA.
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45
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Abstract
The peptide endothelin plays a significant role in a wide array of pathological conditions, including primary pulmonary hypertension and pulmonary arterial hypertension associated with collagen vascular disease. These are life-threatening conditions that can severely compromise the function of the lungs and heart. Inhibiting the actions of endothelin by blockade of its receptors provides a new and effective approach to therapy for patients with these conditions. Bosentan (Tracleer ) is the first orally-active dual endothelin receptor antagonist and has recently been approved in the US, Canada, Switzerland and the EU for the treatment of pulmonary arterial hypertension. Bosentan significantly improves exercise capacity, symptoms and functional status in patients with this disease and also slows clinical deterioration, which may be indicative of a delay of disease progression. Results from large-scale studies of bosentan in patients with pulmonary arterial hypertension and chronic heart failure have established its long-term safety and tolerability profiles. The introduction of the dual endothelin receptor antagonist bosentan has provided an essential treatment for pulmonary arterial hypertension and ongoing trials are evaluating its potential role in the management of other endothelin-mediated disease states.
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Affiliation(s)
- Lewis J Rubin
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of California at San Diego, School of Medicine, 9300 Campus Point Drive, 7372, La Jolla, CA 92037, USA.
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46
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Badesch DB, Bodin F, Channick RN, Frost A, Rainisio M, Robbins IM, Roux S, Rubin LJ, Simonneau G, Sitbon O, Tapson VF. Complete results of the first randomized, placebo-controlled study of bosentan, a dual endothelin receptor antagonist, in pulmonary arterial hypertension. Curr Ther Res Clin Exp 2002. [DOI: 10.1016/s0011-393x(02)80029-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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47
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Davie N, Haleen SJ, Upton PD, Polak JM, Yacoub MH, Morrell NW, Wharton J. ET(A) and ET(B) receptors modulate the proliferation of human pulmonary artery smooth muscle cells. Am J Respir Crit Care Med 2002; 165:398-405. [PMID: 11818328 DOI: 10.1164/ajrccm.165.3.2104059] [Citation(s) in RCA: 234] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We determined the distribution of ET(A) and ET(B) receptors in pulmonary arteries from pulmonary hypertensive patients and control subjects, using in vitro autoradiography, and investigated their role in mediating the proliferative effects of endothelin-1 (ET-1) on distal human pulmonary artery smooth muscle cells (PASMCs). Distal arteries possessed more medial [(125)I]-ET-1 binding sites (105 +/- 10 versus 45 +/- 6 amol/mm(2); p < 0.001) and a greater proportion of ET(B) receptors than proximal arteries (36 +/- 3% versus 3 +/- 1%; p < 0.001). Receptor density in distal arteries and lung parenchyma was twofold greater (p < 0.05) in pulmonary hypertensive patients than in control subjects. ET-1 (10(-9)-10(-7) mol/L) stimulated DNA synthesis (147 +/- 10% of control subjects; p < 0.05) and attenuated the antiproliferative action of cicaprost and forskolin on PASMCs, these effects being mediated via ET(A) and ET(B) receptors. Serum-stimulated proliferation was attenuated by inhibiting either endogenous ET-1 release with phosphoramidon (10(-5) mol/L) or its action with PD145065 (10(-5) mol/L). Cicaprost (10(-10)-10(-7) mol/L) inhibited ET-1 release from PASMCs (49 +/- 16% of control after 24 h; p < 0.001) and increased intracellular cAMP levels, whereas ET(B) receptor stimulation selectively reduced cAMP levels. In conclusion, ET(A) and ET(B) receptors are differentially distributed in human pulmonary arteries. Both receptors promote the proliferation of PASMCs in vitro and may contribute to vascular remodeling in pulmonary hypertension.
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Affiliation(s)
- Neil Davie
- Section on Clinical Pharmacology, Department of Histochemistry, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
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48
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Deuchar GA, Docherty A, MacLean MR, Hicks MN. Pulmonary hypertension secondary to left ventricular dysfunction: the role of nitric oxide and endothelin-1 in the control of pulmonary vascular tone. Br J Pharmacol 2002; 135:1060-8. [PMID: 11861335 PMCID: PMC1573195 DOI: 10.1038/sj.bjp.0704529] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
1. Using an in vivo model of pulmonary hypertension (PHT) secondary to left ventricular dysfunction (LVD), the pulmonary arterial response to the nitric oxide synthase (NOS) blocker L-NAME (30 micromol.min(-1) i.v.) and the subsequent responses to cumulatively administered endothelin-1 (ET-1) (0.001 -- 4 nmol.kg(-1) i.v.) or big ET-1 (0.1 -- 2.0 nmol.kg(-1) i.v.) were studied. Additionally, the effect of the non-selective ET-1 receptor antagonist, SB209670, was investigated. 2. Eight weeks after coronary artery ligation or sham operation, rabbits demonstrated increased mean pulmonary arterial pressure (PAP) accompanied by right ventricular hypertrophy. 3. Blockade of NOS caused a greater increase in basal PAP (increased by 7.7 +/- 1.1 mmHg c.f. 3.8 +/- 1.0 mmHg in controls, P<0.05) and uncovered a greater pulmonary pressor response to exogenous ET-1 in rabbits with PHT (increased by 10.2 +/- 2.3 mmHg c.f. 4.9 +/- 1.0 mmHg in controls, P<0.05). 4. Big ET-1 evoked a pulmonary pressor effect, in both groups of rabbits, that was increased following blockade of NOS and was more potent in rabbits with PHT. 5. The non-selective ET-1 receptor antagonist, SB209670, reduced basal PAP (from 16.9 mmHg to 15.9 mmHg, P < 0.05) in rabbits with PHT and blocked the response to ET-1 in the presence of L-NAME. 6. In conclusion, the results demonstrate that basal NO activity masks a pulmonary pressor response to exogenously administered ET-1. An increased responsiveness to ET-1 was shown in the pulmonary arterial bed of rabbits with PHT secondary to LVD, implicating a pathophysiological role for ET-1 in this model.
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Affiliation(s)
- Graeme A Deuchar
- Department of Medical Cardiology, University of Glasgow, Royal Infirmary, Glasgow G31 2ER
| | - Andrew Docherty
- Department of Medical Cardiology, University of Glasgow, Royal Infirmary, Glasgow G31 2ER
| | - Margaret R MacLean
- Division of Neuroscience and Biomedical Systems, IBLS, West Medical Building, University of Glasgow, Glasgow G12 8QQ
| | - Martin N Hicks
- Department of Medical Cardiology, University of Glasgow, Royal Infirmary, Glasgow G31 2ER
- Author for correspondence:
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49
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Conant AR, Oo AY, Dashwood MR, Collard K, Chester MR, Dihmis WC, Simpson AWM. Endothelin receptors in cultured and native human radial artery smooth muscle. J Cardiovasc Pharmacol 2002; 39:130-41. [PMID: 11743235 DOI: 10.1097/00005344-200201000-00014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In human vascular smooth muscle cells endothelin-1, acting at both endothelin A and endothelin B receptors, has been demonstrated to be both a potent vasoconstrictor and mitogen. Our aim was to study the functional expression of endothelin receptors in human radial artery smooth muscle using both native tissue and cultured cells (RASMCs). Radial artery smooth muscle cells were cultured from arterial explants and loaded with the calcium fluorescent dye fura-2. Cells responded to endothelin-1 and a variety of other vasoconstrictors with rises in cytoplasmic calcium ([Ca2+]c). Arterial rings responded to endothelin-1 with an increase in tension. The response of both cells and arterial rings to endothelin-1 was characterized using the selective endothelin A receptor antagonist BQ123 and the endothelin B receptor antagonist BQ788. The RASMCs were found to express [Ca2+]c responses consistent with the expression of only the endothelin A receptor. Endothelin-1-mediated vasoconstriction in radial artery rings was unaffected by BQ788 but was completely blocked by BQ123. Using the selective radioligands [125I]-PD151242 and [125I]-BQ3020 and a combination of in vitro receptor autoradiography and isolated cell preparations, endothelin A receptors were confirmed to be present on RASMCs and on arterial sections, whereas endothelin B binding was barely detectable on native smooth muscle and on RASMCs.
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Affiliation(s)
- Alan R Conant
- Cardiothoracic Center, Liverpool NHS Trust, Liverpool, UK.
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50
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Kim NHS, Rubin LJ. Endothelin in health and disease: endothelin receptor antagonists in the management of pulmonary artery hypertension. J Cardiovasc Pharmacol Ther 2002; 7:9-19. [PMID: 12000973 DOI: 10.1177/107424840200700i102] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Endothelin (ET) has been identified as playing a fundamental role in many disease processes. Therapeutic efforts at interrupting ET's pathologic effects have focused on endothelin receptor antagonists (ERAs), of which two, bosentan and sitaxsentan, have been evaluated for the treatment of both primary and secondary pulmonary arterial hypertension (PAH). We discuss the multiple actions of ET, its role in various disease states, and the effects of ET receptor stimulation and blockade. Current classification and management of PAH are reviewed, along with the promise of greatly improved treatment generated by recent and ongoing clinical trials using ERAs.
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Affiliation(s)
- Nick H S Kim
- Division of Pulmonary and Critical Care Medicine, University of California, San Diego, La Jolla, CA 92037-1300, USA
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