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Daikohara K, Akanuma SI, Kubo Y, Hosoya KI. Lipopolysaccharide-Induced Functional Alteration of P-glycoprotein in the Ex Vivo Rat Inner Blood-Retinal Barrier. Int J Mol Sci 2022; 23:ijms232415504. [PMID: 36555148 PMCID: PMC9779076 DOI: 10.3390/ijms232415504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/02/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022] Open
Abstract
At the inner blood-retinal barrier (BRB), P-glycoprotein (P-gp) contributes to maintaining the homeostasis of substance concentration in the retina by transporting drugs and exogenous toxins from the retina to the circulating blood. Under inflammatory conditions, P-gp activities have been reported to be altered in various tissues. The purpose of this study was to clarify the alterations in P-gp activity at the inner BRB due to lipopolysaccharide (LPS), an inflammatory agent, and the molecular mechanisms of the alterations induced by LPS. Ex vivo P-gp activity was evaluated as luminal accumulation of 7-nitro-2,1,3-benzoxadiazole-cyclosporin A (NBD-CSA), a fluorescent P-gp substrate, in freshly prepared rat retinal capillaries. The luminal NBD-CSA accumulation was significantly decreased in the presence of LPS, indicating that P-gp activity at the inner BRB is reduced by LPS. This LPS-induced attenuation of the luminal NBD-CSA accumulation was abolished by inhibiting toll-like receptor 4 (TLR4), a receptor for LPS. Furthermore, an inhibitor/antagonist of tumor necrosis factor receptor 1, endothelin B receptor, nitric oxide synthase, or protein kinase C (PKC) significantly restored the LPS-induced decrease in the luminal NBD-CSA accumulation. Consequently, it is suggested that the TLR4/PKC pathway is involved in the reduction in P-gp function in the inner BRB by LPS.
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Affiliation(s)
- Kiyotaka Daikohara
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Shin-ichi Akanuma
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
- Correspondence: ; Tel.: +81-76-434-7508
| | - Yoshiyuki Kubo
- Laboratory of Drug Disposition and Pharmacokinetics, Faculty of Pharma-Sciences, Teikyo University, Kaga 2-11-1, Tokyo 173-8605, Japan
| | - Ken-ichi Hosoya
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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2
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Juif PE, Dingemanse J, Ufer M. Clinical Pharmacology of Clazosentan, a Selective Endothelin A Receptor Antagonist for the Prevention and Treatment of aSAH-Related Cerebral Vasospasm. Front Pharmacol 2021; 11:628956. [PMID: 33613288 PMCID: PMC7890197 DOI: 10.3389/fphar.2020.628956] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 12/30/2020] [Indexed: 11/16/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage (aSAH) may lead to cerebral vasospasm and is associated with significant morbidity and mortality. It represents a major unmet medical need due to few treatment options with limited efficacy. The role of endothelin-1 (ET-1) and its receptor ETA in the pathogenesis of aSAH-induced vasospasm suggests antagonism of this receptor as promising asset for pharmacological treatment. Clazosentan is a potent ETA receptor antagonist for intravenous use currently under development for the prevention of aSAH-induced cerebral vasospasm. The pharmacokinetics of clazosentan are characterized by an intermediate clearance, a volume of distribution similar to that of the extracellular fluid volume, dose-proportional exposure, an elimination independent of drug-metabolizing enzymes, and a disposition mainly dependent on the hepatic uptake transporter organic anion transport polypeptide 1B1/1B3. In healthy subjects, clazosentan leads to an increase in ET-1 concentration and prevents the cardiac and renal effects mediated by infusion of ET-1. In patients, it significantly reduced the incidence of moderate or severe vasospasm as well as post-aSAH vasospasm-related morbidity and mortality. Clazosentan is well tolerated up to the expected therapeutic dose of 15 mg/h and, in aSAH patients, lung complications, hypotension, and anemia were adverse events more commonly reported following clazosentan than placebo. In summary, clazosentan has a pharmacokinetic, pharmacodynamic, and safety profile suitable to become a valuable asset in the armamentarium of therapeutic modalities to prevent aSAH-induced cerebral vasospasm.
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Affiliation(s)
- Pierre-Eric Juif
- Department of Clinical Pharmacology, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
| | - Jasper Dingemanse
- Department of Clinical Pharmacology, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
| | - Mike Ufer
- Department of Clinical Pharmacology, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
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3
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Douma LG, Crislip GR, Cheng KY, Barral D, Masten S, Holzworth M, Roig E, Glasford K, Beguiristain K, Li W, Bratanatawira P, Lynch IJ, Cain BD, Wingo CS, Gumz ML. Knockout of the circadian clock protein PER1 results in sex-dependent alterations of ET-1 production in mice in response to a high-salt diet plus mineralocorticoid treatment. Can J Physiol Pharmacol 2020; 98:579-586. [PMID: 32437627 DOI: 10.1139/cjpp-2019-0688] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Previously, we showed that global knockout (KO) of the circadian clock transcription factor PER1 in male, but not female, mice fed a high-salt diet plus mineralocorticoid treatment (HS/DOCP) resulted in nondipping hypertension and decreased night/day ratio of sodium (Na) excretion. Additionally, we have shown that the endothelin-1 (ET-1) gene is targeted by both PER1 and aldosterone. We hypothesized that ET-1 would exhibit a sex-specific response to HS/DOCP treatment in PER1 KO. Here we show that male, but not female, global PER1 KO mice exhibit a decreased night/day ratio of urinary ET-1. Gene expression analysis revealed significant genotype differences in ET-1 and endothelin A receptor (ETA) expression in male, but not female, mice in response to HS/DOCP. Additionally, both wild-type and global PER1 KO male mice significantly increase endothelin B receptor (ETB) expression in response to HS/DOCP, but female mice do not. Finally, siRNA-mediated knockdown of PER1 in mouse cortical collecting duct cells (mpkCCDc14) resulted in increased ET-1 mRNA expression and peptide secretion in response to aldosterone treatment. These data suggest that PER1 is a negative regulator of ET-1 expression in response to HS/DOCP, revealing a novel mechanism for the regulation of renal Na handling in response to HS/DOCP treatment.
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Affiliation(s)
- Lauren G Douma
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - G Ryan Crislip
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Kit-Yan Cheng
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Dominique Barral
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Sarah Masten
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Meaghan Holzworth
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Emilio Roig
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Krystal Glasford
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Kevin Beguiristain
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Wendy Li
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - Phillip Bratanatawira
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
| | - I Jeanette Lynch
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA.,North Florida/South Georgia Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32611, USA
| | - Brian D Cain
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
| | - Charles S Wingo
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA.,North Florida/South Georgia Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32611, USA
| | - Michelle L Gumz
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA.,Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA.,North Florida/South Georgia Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32611, USA
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4
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Adams KL, Riparini G, Banerjee P, Breur M, Bugiani M, Gallo V. Endothelin-1 signaling maintains glial progenitor proliferation in the postnatal subventricular zone. Nat Commun 2020; 11:2138. [PMID: 32358570 PMCID: PMC7195367 DOI: 10.1038/s41467-020-16028-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 04/06/2020] [Indexed: 12/18/2022] Open
Abstract
Signaling molecules that regulate neurodevelopmental processes in the early postnatal subventricular zone (SVZ) are critical for proper brain development yet remain poorly characterized. Here, we report that Endothelin-1 (ET-1), a molecular component of the postnatal SVZ, promotes radial glial cell maintenance and proliferation in an autocrine manner via Notch signaling. Loss of ET-1 signaling increases neurogenesis and reduces oligodendrocyte progenitor cell proliferation (OPC) in the developing SVZ, thereby altering cellular output of the stem cell niche. We also show that ET-1 is required for increased neural stem cell and OPC proliferation in the adult mouse SVZ following demyelination. Lastly, high levels of ET-1 in the SVZ of patients with Cathepsin A-related arteriopathy with strokes and leukoencephalopathy correlate with an increased number of SVZ OPCs, suggesting ET-1's role as a regulator of glial progenitor proliferation may be conserved in humans. ET-1 signaling therefore presents a potential new therapeutic target for promoting SVZ-mediated cellular repair.
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Affiliation(s)
- Katrina L Adams
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC, 20010, USA
| | - Giulia Riparini
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC, 20010, USA
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
| | - Payal Banerjee
- Children's National Research Institute Bioinformatics Unit, Children's National Hospital, Washington, DC, 20010, USA
| | - Marjolein Breur
- Department of Child Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Marianna Bugiani
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC, 20010, USA.
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5
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Huang X, Chen C, Zhu X, Zheng X, Li S, Gong X, Xiao Z, Jiang N, Yu C, Yi C. Transdermal BQ-788/EA@ZnO quantum dots as targeting and smart tyrosinase inhibitors in melanocytes. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 102:45-52. [PMID: 31147016 DOI: 10.1016/j.msec.2019.04.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/24/2019] [Accepted: 04/12/2019] [Indexed: 02/02/2023]
Abstract
Tyrosinase inhibitors could effectively limit the activity of tyrosinase in melanocytes to reduce the excessive synthesis and deposition of melanin. However, low skin permeability and lacking in targeting greatly restricted their application. Herein, ZnO quantum dots were synthesized by gel-sol method and grafted with BQ-788, which have been employed as transdermal and targeting carrier to delivery ellagic acid to melanocytes. Ellagic acid loaded ZnO quantum dots with the size distribution of around 9 nm could targetedly bind to melanocytes and enter the melanocytes by endocytosis within 1 h. The ellagic acid release behavior was controlled by the decreasing of pH via the rapid dissolution of ZnO. When the concentration of BQ-788/EA@ZnO was 12.5 μg/mL, the inhibition rate on tyrosinase activity and melanin deposition were up to 44.23 ± 4.97% and 37.50 ± 5.23%, respectively. In view of their good biocompatibility, they were of great potential in clinically external application for tyrosinase inhibition.
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Affiliation(s)
- Xiao Huang
- School of Sports and Health Science, Tongren University, Tongren 554300, China; School of Sports and Physical Education, Nanjing Normal University, Nanjing 210046, China; Institute of Cultural and Technological Industry Innovation of Tongren, Tongren 554300, China.
| | - Chun Chen
- College of Material and Chemical Engineering, Tongren University, Tongren 554300, China
| | - Xinting Zhu
- Basic Medical College, Zunyi Medical University, Zunyi 563000, China; Guizhou Provincial College-based Key Lab for Tumor Prevention and Treatment with Distinctive Medicines, Zunyi Medical University, Zunyi 563000, China
| | - Xi Zheng
- School of Sports and Health Science, Tongren University, Tongren 554300, China
| | - Sanhua Li
- Guizhou Provincial College-based Key Lab for Tumor Prevention and Treatment with Distinctive Medicines, Zunyi Medical University, Zunyi 563000, China
| | - Xingquan Gong
- College of Material and Chemical Engineering, Tongren University, Tongren 554300, China
| | - Zuli Xiao
- College of Material and Chemical Engineering, Tongren University, Tongren 554300, China
| | - Nian Jiang
- Guizhou Provincial College-based Key Lab for Tumor Prevention and Treatment with Distinctive Medicines, Zunyi Medical University, Zunyi 563000, China
| | - Cangyan Yu
- Guizhou Provincial College-based Key Lab for Tumor Prevention and Treatment with Distinctive Medicines, Zunyi Medical University, Zunyi 563000, China
| | - Caixia Yi
- School of Sports and Health Science, Tongren University, Tongren 554300, China.
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6
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Palygin O, Miller BS, Nishijima Y, Zhang DX, Staruschenko A, Sorokin A. Endothelin receptor A and p66Shc regulate spontaneous Ca 2+ oscillations in smooth muscle cells controlling renal arterial spontaneous motion. FASEB J 2018; 33:2636-2645. [PMID: 30303741 DOI: 10.1096/fj.201800776rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Adaptor protein p66Shc is overexpressed in smooth muscle cells of renal resistance vessels of hypertensive salt-sensitive rats and is involved in the regulation of renal vascular tone. We applied 2-photon laser scanning fluorescence microscopy to analyze spontaneous dynamic fluctuations in intracellular calcium concentrations ([Ca2+]i) in smooth muscle cells embedded in the walls of freshly isolated renal resistance arteries. The amplitude, number of events, and frequency of spontaneous [Ca2+]i oscillations triggered by endogenously released endothelin-1 were recorded in smooth muscle cells of the renal arteries. Endothelin receptor A antagonist BQ123 dramatically reduced the amplitude and frequency of spontaneous Ca2+ events, producing marked inhibition of renal vessels spontaneous motion. Spontaneous Ca2+ fluctuations in smooth muscle cells of p66Shc knockout (p66ShcKO) rats had significantly higher amplitude than in control rats. The frequency of spontaneous [Ca2+]i oscillations did not change in p66ShcKO rats, suggesting that p66Shc expression did not affect endothelin-1 release from resident endothelial cells. Acute application of endothelin-1 revealed significantly elevated production of the total [Ca2+]i in p66ShcKO rats. Spontaneous cytosolic Ca2+ oscillations in smooth muscle cells of renal vessels mediate their spontaneous motion via the endothelin-1/endothelin receptor A pathway. p66Shc decreases the amplitude of individual changes in [Ca2+]i, which mitigates the spontaneous motion of renal vessels.-Palygin, O., Miller, B. S., Nishijima, Y., Zhang, D. X., Staruschenko, A., Sorokin, A. Endothelin receptor A and p66Shc regulate spontaneous Ca2+ oscillations in smooth muscle cells controlling renal arterial spontaneous motion.
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Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Bradley S Miller
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Yoshinori Nishijima
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Division of Cardiology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; and.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David X Zhang
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Division of Cardiology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; and.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Andrey Sorokin
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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7
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Mella RM, Kortazar D, Roura-Ferrer M, Salado C, Valcárcel M, Castilla A, Villacé P. Nomad Biosensors: A New Multiplexed Technology for the Screening of GPCR Ligands. SLAS Technol 2018; 23:207-216. [PMID: 29412765 DOI: 10.1177/2472630318754828] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Nomad Technology (Innoprot [Innovative Technologies in Biological Systems], Derio, Spain), a novel tool for multiplexing high-throughput cell-based G protein-coupled receptor (GPCR) assays, is described in this work. This new technology comprises a family of fluorescent biosensors called Nomad Biosensors that allow for the measurement of responses mediated by G proteins through their interactions with second-messenger transduction proteins. GPCRs are one of the largest protein families of receptors in eukaryotes, and their signaling mediates important physiological processes within cells. Thus, GPCRs are associated with a wide variety of diseases, and considered major targets in therapeutic research. Nomad constitutes a novel tool for unraveling the mechanism of GPCR signal transduction by simultaneously tracing different pathways. GPCR activation changes the structural folding of the biosensor and promotes its vesicularization, as well as an increase in the fluorescence intensity. Based on this technology, the MPXNomad cellular model was developed to discriminate between the Ca2+-mediated pathway and the cyclic adenosine monophosphate (cAMP)-mediated pathway. To validate this model, endothelin receptor B (ETBR) was coexpressed into the MPXNomad cell line and assessed with a specific agonist, an antagonist, and a chemical library of compounds. Nomad Technology optimizes the identification of novel GPCR ligands and enables the testing of large numbers of compounds.
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Affiliation(s)
- Rosa M Mella
- 1 Innoprot (Innovative Technologies in Biological Systems), Derio, Spain
| | - Danel Kortazar
- 1 Innoprot (Innovative Technologies in Biological Systems), Derio, Spain
| | | | - Clarisa Salado
- 1 Innoprot (Innovative Technologies in Biological Systems), Derio, Spain
| | - María Valcárcel
- 1 Innoprot (Innovative Technologies in Biological Systems), Derio, Spain
| | - Amaia Castilla
- 1 Innoprot (Innovative Technologies in Biological Systems), Derio, Spain
| | - Patricia Villacé
- 1 Innoprot (Innovative Technologies in Biological Systems), Derio, Spain
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8
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Smith MP, Rowling EJ, Miskolczi Z, Ferguson J, Spoerri L, Haass NK, Sloss O, McEntegart S, Arozarena I, von Kriegsheim A, Rodriguez J, Brunton H, Kmarashev J, Levesque MP, Dummer R, Frederick DT, Andrews MC, Cooper ZA, Flaherty KT, Wargo JA, Wellbrock C. Targeting endothelin receptor signalling overcomes heterogeneity driven therapy failure. EMBO Mol Med 2017; 9:1011-1029. [PMID: 28606996 PMCID: PMC5538298 DOI: 10.15252/emmm.201607156] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 05/04/2017] [Accepted: 05/05/2017] [Indexed: 11/17/2022] Open
Abstract
Approaches to prolong responses to BRAF targeting drugs in melanoma patients are challenged by phenotype heterogeneity. Melanomas of a "MITF-high" phenotype usually respond well to BRAF inhibitor therapy, but these melanomas also contain subpopulations of the de novo resistance "AXL-high" phenotype. > 50% of melanomas progress with enriched "AXL-high" populations, and because AXL is linked to de-differentiation and invasiveness avoiding an "AXL-high relapse" is desirable. We discovered that phenotype heterogeneity is supported during the response phase of BRAF inhibitor therapy due to MITF-induced expression of endothelin 1 (EDN1). EDN1 expression is enhanced in tumours of patients on treatment and confers drug resistance through ERK re-activation in a paracrine manner. Most importantly, EDN1 not only supports MITF-high populations through the endothelin receptor B (EDNRB), but also AXL-high populations through EDNRA, making it a master regulator of phenotype heterogeneity. Endothelin receptor antagonists suppress AXL-high-expressing cells and sensitize to BRAF inhibition, suggesting that targeting EDN1 signalling could improve BRAF inhibitor responses without selecting for AXL-high cells.
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Affiliation(s)
- Michael P Smith
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Emily J Rowling
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Zsofia Miskolczi
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Jennifer Ferguson
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Loredana Spoerri
- Translational Research Institute, The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, Qld, Australia
| | - Nikolas K Haass
- Translational Research Institute, The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, Qld, Australia
- Discipline of Dermatology, University of Sydney, Sydney, NSW, Australia
| | - Olivia Sloss
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Sophie McEntegart
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Imanol Arozarena
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
- Navarrabiomed-Fundación Miguel Servet-Idisna, Pamplona, Spain
| | | | - Javier Rodriguez
- Systems Biology Ireland, School of Medicine, UCD, Dublin 4, Ireland
| | - Holly Brunton
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Jivko Kmarashev
- Department of Dermatology, Universitätsspital Zürich, University of Zurich, Zurich, Switzerland
| | - Mitchell P Levesque
- Department of Dermatology, Universitätsspital Zürich, University of Zurich, Zurich, Switzerland
| | - Reinhard Dummer
- Department of Dermatology, Universitätsspital Zürich, University of Zurich, Zurich, Switzerland
| | - Dennie T Frederick
- Department of Medicine, Massachusetts General Hospital Cancer Center, Boston, MA, USA
| | - Miles C Andrews
- Division of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Zachary A Cooper
- Division of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Keith T Flaherty
- Department of Medicine, Massachusetts General Hospital Cancer Center, Boston, MA, USA
| | - Jennifer A Wargo
- Division of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Claudia Wellbrock
- Manchester Cancer Research Centre, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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9
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Vercauteren M, Trensz F, Pasquali A, Cattaneo C, Strasser DS, Hess P, Iglarz M, Clozel M. Endothelin ETA Receptor Blockade, by Activating ETB Receptors, Increases Vascular Permeability and Induces Exaggerated Fluid Retention. J Pharmacol Exp Ther 2017; 361:322-333. [DOI: 10.1124/jpet.116.234930] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/17/2017] [Indexed: 11/22/2022] Open
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10
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Endothelin-1: Biosynthesis, Signaling and Vasoreactivity. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 77:143-75. [PMID: 27451097 DOI: 10.1016/bs.apha.2016.05.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Endothelin-1 (ET-1) is an extremely potent vasoconstrictor peptide originally isolated from endothelial cells. Its synthesis, mainly regulated at the gene transcription level, involves processing of a precursor by a furin-type proprotein convertase to an inactive intermediate, big ET-1. The latter peptide can then be cleaved directly by an endothelin-converting enzyme (ECE) into ET-1 or reach the active metabolite through a two-step process involving chymase hydrolyzing big ET-1 to ET-1 (1-31), itself needing conversion to ET-1 by neprilysin (NEP) to exert physiological activity. ET-1 signals through two G protein-coupled receptors, endothelin receptor A (ETA) and endothelin receptor B (ETB). Both receptors induce an increase in intracellular Ca(2+), mainly from the extracellular space through voltage-independent mechanisms, the receptor-operated channels and store-operated channels. ET-1 also induces signaling through epidermal growth factor receptor transactivation, oxidative stress induction, rho-kinase, and the activation (ETA) or inhibition (ETB) of the adenylate cyclase/cyclic adenosine monophosphate pathway. Arterial vasoconstriction is mediated mainly by the ETA receptor. ET-1, via endothelium-located ETB, relaxes arteries or constricts vessels following activation of the same receptor type on the smooth muscle, where it can interact with ETA. In addition, ETB-dependent vasoconstriction seems more prominent in the venous vasculature. A better understanding of how ET-1 is synthesized and how ETA and ETB receptors interact could help design better pharmacological agents in the treatment of cardiovascular diseases where targeting the ET-1 system is indicated.
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11
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Boratkó A, Veréb Z, Petrovski G, Csortos C. TIMAP-protein phosphatase 1-complex controls endothelin-1 production via ECE-1 dephosphorylation. Int J Biochem Cell Biol 2016; 73:11-18. [DOI: 10.1016/j.biocel.2016.01.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 01/16/2016] [Accepted: 01/20/2016] [Indexed: 01/13/2023]
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12
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Discovery of Dual ETA/ETB Receptor Antagonists from Traditional Chinese Herbs through in Silico and in Vitro Screening. Int J Mol Sci 2016; 17:389. [PMID: 26999111 PMCID: PMC4813245 DOI: 10.3390/ijms17030389] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 02/25/2016] [Accepted: 03/04/2016] [Indexed: 11/30/2022] Open
Abstract
Endothelin-1 receptors (ETAR and ETBR) act as a pivotal regulator in the biological effects of ET-1 and represent a potential drug target for the treatment of multiple cardiovascular diseases. The purpose of the study is to discover dual ETA/ETB receptor antagonists from traditional Chinese herbs. Ligand- and structure-based virtual screening was performed to screen an in-house database of traditional Chinese herbs, followed by a series of in vitro bioassay evaluation. Aristolochic acid A (AAA) was first confirmed to be a dual ETA/ETB receptor antagonist based intracellular calcium influx assay and impedance-based assay. Dose-response curves showed that AAA can block both ETAR and ETBR with IC50 of 7.91 and 7.40 μM, respectively. Target specificity and cytotoxicity bioassay proved that AAA is a selective dual ETA/ETB receptor antagonist and has no significant cytotoxicity on HEK293/ETAR and HEK293/ETBR cells within 24 h. It is a feasible and effective approach to discover bioactive compounds from traditional Chinese herbs using in silico screening combined with in vitro bioassay evaluation. The structural characteristic of AAA for its activity was especially interpreted, which could provide valuable reference for the further structural modification of AAA.
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Kim JY, Ko AR, Hyun HW, Kang TC. ETB receptor-mediated MMP-9 activation induces vasogenic edema via ZO-1 protein degradation following status epilepticus. Neuroscience 2015; 304:355-67. [PMID: 26232046 DOI: 10.1016/j.neuroscience.2015.07.065] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/08/2015] [Accepted: 07/24/2015] [Indexed: 01/08/2023]
Abstract
The blood-brain barrier (BBB) is formed by the endothelial cells with specialized tight junctions (TJs) lining the blood vessels and astroglial endfeet surrounding the blood vessels. Although BBB disruption during brain insults leads to vasogenic edema as one of the primary steps in the epileptogenic process, little is known about the molecular and physiological events concerning vasogenic edema formation. In the present study, status epilepticus (SE) changed the expressions and subcellular localizations of TJ proteins (claudin-5, occludin and zonula occludens-1 (ZO-1)) in endothelial cells of the rat piriform cortex. Among TJ proteins, the alteration in ZO-1 expression was relevant to endothelin B (ETB) receptor-mediated endothelial nitric oxide synthase (eNOS) activation, which increased matrix metalloproteinase-9 (MMP-9) activity. Indeed, BQ788 (an ETB receptor antagonist) effectively attenuated SE-induced vasogenic edema by inhibiting eNOS-mediated MMP-9 activation and ZO-1 protein degradation in endothelial cells, although astroglial endfeet were detached from endothelial cells. Therefore, we suggest that SE-induced ETB receptor/eNOS-mediated MMP-9 activation may lead to impairments of endothelial cell function via TJ protein degradation, which are involved in vasogenic edema formation independent of perivascular astroglial functions.
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Affiliation(s)
- J Y Kim
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon 200-702, South Korea
| | - A-R Ko
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon 200-702, South Korea
| | - H-W Hyun
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon 200-702, South Korea
| | - T-C Kang
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon 200-702, South Korea.
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Guo J, Li Y, Chen Z, He Z, Zhang B, Li Y, Hu J, Han M, Xu Y, Li Y. N-acetylcysteine treatment following spinal cord trauma reduces neural tissue damage and improves locomotor function in mice. Mol Med Rep 2015; 12:37-44. [PMID: 25738883 PMCID: PMC4438879 DOI: 10.3892/mmr.2015.3390] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 11/12/2014] [Indexed: 01/11/2023] Open
Abstract
Following spinal cord trauma, mitochondrial dysfunction associated with increased oxidative stress is a critical event leading to leukocyte inflammatory responses, neuronal cell death and demyelination, contributing to permanent locomotor and neurological disability. The present study demonstrated that the mitochondrial enhancer N-acetylcysteine (NAC) may restore redox balance via enhancement of mitochondrial respiratory activity following traumatic spinal cord injury (SCI). In addition, NAC ameliorates oxidative stress-induced neuronal loss, demyelination, leukocyte infiltration and inflammatory mediator expression and improves long-term locomotor function. Furthermore, neuronal survival and neurological recovery are significantly correlated with increased mitochondrial bioenergetics in SCI following treatment with NAC. Therefore, NAC may represent a potential therapeutic agent for preserving mitochondrial dynamics and integrity following traumatic SCI.
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Affiliation(s)
- Jian Guo
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yiqiao Li
- Central Laboratory, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Zhong Chen
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Zhennian He
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Bin Zhang
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yonghuan Li
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Jianghua Hu
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Mingyuan Han
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yuanlin Xu
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yongfu Li
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
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Protective effects of endothelin receptor A and B inhibitors against doxorubicin-induced cardiomyopathy. Biochem Pharmacol 2015; 94:109-29. [PMID: 25660617 DOI: 10.1016/j.bcp.2015.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/27/2015] [Accepted: 01/27/2015] [Indexed: 11/21/2022]
Abstract
The clinical efficiency of the highly potent antitumor agent doxorubicin is limited by cardiotoxic effects. In a murine doxorubicin cardiotoxicity model, increased endothelin-1 (ET-1) expression and cardioprotective effects of the dual ET-1 blocker bosentan were demonstrated. To date it is unclear if combined blocking of endothelin A/B receptors is necessary or whether selective inhibition of one of the ET-1 receptors is sufficient for the observed cardioprotection. Therefore, we investigated the impact of dual (bosentan) and single endothelin receptor antagonism through sitaxentan (receptor A blocker) or BQ788 (receptor B blocker) in a murine doxorubicin cardiotoxicity model (C57BL/6N). Simultaneous administration of each endothelin receptor antagonist (ERA) with doxorubicin resulted in a significantly improved hemodynamic performance in comparison to the impaired cardiac function in control mice with bosentan being most effective but closely followed by sitaxentan and also BQ788. This cardioprotection was not caused by diminished doxorubicin levels in heart since the doxorubicin content in cardiac tissue was not altered by ERAs significantly. However, whole transcript expression profiling showed partly different effects of the ERAs on doxorubicin-modulated cardiac gene expression of genes involved in signal transduction (e.g. Stat3, Pim1, Akt1, Plcb2), fibrosis (e.g. Myl4), energy production (e.g. Ant1) or oxidative stress (e.g. Aox1). Furthermore, doxorubicin-mediated gene regulations were verified in the murine cardiomyocyte model HL-1 showing partly reversed expression patterns after co-administration of the ERAs. In summary, our results demonstrate strong cardioprotective effects of blocking ET-1 receptors against the doxorubicin-related cardiomyopathy and provide evidence to potential underlying signaling pathways.
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Guo J, Li Y, He Z, Zhang B, Li Y, Hu J, Han M, Xu Y, Li Y, Gu J, Dai B, Chen Z. Targeting endothelin receptors A and B attenuates the inflammatory response and improves locomotor function following spinal cord injury in mice. Int J Mol Med 2014; 34:74-82. [PMID: 24756152 PMCID: PMC4072339 DOI: 10.3892/ijmm.2014.1751] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 04/01/2014] [Indexed: 11/06/2022] Open
Abstract
After spinal cord injury (SCI), the disruption of blood-spinal cord barrier by activation of the endothelin (ET) system is a critical event leading to leukocyte infiltration, inflammatory response and oxidative stress, contributing to neurological disability. In the present study, we showed that blockade of ET receptor A (ETAR) and/or ET receptor B (ETBR) prevented early inflammatory responses directly via the inhibition of neutrophil and monocyte diapedesis and inflammatory mediator production following traumatic SCI in mice. Long-term neurological improvement, based on a series of tests of locomotor performance, occurred only in the spinal cord‑injured mice following blockade of ETAR and ETBR. We also examined the post‑traumatic changes of the micro-environment within the injured spinal cord of mice following blockade of ET receptors. Oxidative stress reflects an imbalance between malondialdehyde and superoxide dismutase in spinal cord‑injured mice treated with vehicle, whereas blockade of ETAR and ETBR reversed the oxidation state imbalance. In addition, hemeoxygenase-1, a protective protease involved in early SCI, was increased in spinal cord‑injured mice following the blockade of ETAR and ETBR, or only ETBR. Matrix metalloproteinase-9, a tissue-destructive protease involved in early damage, was decreased in the injured spinal cord of mice following blockade of ETAR, ETBR or a combination thereof. The findings of the present study therefore suggested an association between ETAR and ETBR in regulating early pathogenesis of SCI and determining the outcomes of long‑term neurological recovery.
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Affiliation(s)
- Jian Guo
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yiqiao Li
- Central Laboratory, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Zhennian He
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Bin Zhang
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yonghuan Li
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Jianghua Hu
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Mingyuan Han
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yuanlin Xu
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Yongfu Li
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Jie Gu
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Bo Dai
- Department of Orthopaedic Surgery, Ningbo Beilun People Hospital, Ningbo, Zhejiang 315800, P.R. China
| | - Zhong Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310000, P.R. China
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Ou M, Dang Y, Mazzuca MQ, Basile R, Khalil RA. Adaptive regulation of endothelin receptor type-A and type-B in vascular smooth muscle cells during pregnancy in rats. J Cell Physiol 2014; 229:489-501. [PMID: 24105843 DOI: 10.1002/jcp.24469] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 09/06/2013] [Indexed: 12/26/2022]
Abstract
Normal pregnancy is associated with systemic vasodilation and decreased vascular contraction, partly due to increased release of endothelium-derived vasodilator substances. Endothelin-1 (ET-1) is an endothelium-derived vasoconstrictor acting via endothelin receptor type A (ETA R) and possibly type B (ETB R) in vascular smooth muscle cells (VSMCs), with additional vasodilator effects via endothelial ETB R. However, the role of ET-1 receptor subtypes in the regulation of vascular function during pregnancy is unclear. We investigated whether the decreased vascular contraction during pregnancy reflects changes in the expression/activity of ETAR and ETBR. Contraction was measured in single aortic VSMCs isolated from virgin, mid-pregnant (mid-Preg, day 12), and late-Preg (day 19) Sprague-Dawley rats, and the mRNA expression, protein amount, tissue and cellular distribution of ETAR and ETBR were examined using RT-PCR, Western blots, immunohistochemistry, and immunofluorescence. Phenylephrine (Phe, 10(-5) M), KCl (51 mM), and ET-1 (10(-6) M) caused VSMC contraction that was in late-Preg < mid-Preg and virgin rats. In VSMCs treated with ETB R antagonist BQ788, ET-1 caused significant contraction that was still in late-Preg < mid-Preg and virgin rats. In VSMCs treated with the ETAR antagonist BQ123, ET-1 caused a small contraction; and the ETBR agonists IRL-1620 and sarafotoxin 6c (S6c) caused similar contraction that was in late-Preg < mid-Preg and virgin rats. RT-PCR revealed similar ETAR, but greater ETBR mRNA expression in pregnant versus virgin rats. Western blots revealed similar ETAR, and greater protein amount of ETBR in endothelium-intact vessels, but reduced ETBR in endothelium-denuded vessels of pregnant versus virgin rats. Immunohistochemistry revealed prominent ETBR staining in the intima, but reduced ETAR and ETBR in the aortic media of pregnant rats. Immunofluorescence signal for ETAR and ETBR was less in VSMCs of pregnant versus virgin rats. The pregnancy-associated decrease in ETAR- and ETBR-mediated VSMC contraction appears to involve downregulation of ETAR and ETBR expression/activity in VSM, and may play a role in the adaptive vasodilation during pregnancy.
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Affiliation(s)
- Minghui Ou
- Vascular Surgery Research Laboratory, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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Vascular endothelial cells mediate mechanical stimulation-induced enhancement of endothelin hyperalgesia via activation of P2X2/3 receptors on nociceptors. J Neurosci 2013; 33:2849-59. [PMID: 23407944 DOI: 10.1523/jneurosci.3229-12.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Endothelin-1 (ET-1) is unique among a broad range of hyperalgesic agents in that it induces hyperalgesia in rats that is markedly enhanced by repeated mechanical stimulation at the site of administration. Antagonists to the ET-1 receptors, ET(A) and ET(B), attenuated both initial as well as stimulation-induced enhancement of hyperalgesia (SIEH) by endothelin. However, administering antisense oligodeoxynucleotide to attenuate ET(A) receptor expression on nociceptors attenuated ET-1 hyperalgesia but had no effect on SIEH, suggesting that this is mediated via a non-neuronal cell. Because vascular endothelial cells are both stretch sensitive and express ET(A) and ET(B) receptors, we tested the hypothesis that SIEH is dependent on endothelial cells by impairing vascular endothelial function with octoxynol-9 administration; this procedure eliminated SIEH without attenuating ET-1 hyperalgesia. A role for protein kinase Cε (PKCε), a second messenger implicated in the induction and maintenance of chronic pain, was explored. Intrathecal antisense for PKCε did not inhibit either ET-1 hyperalgesia or SIEH, suggesting no role for neuronal PKCε; however, administration of a PKCε inhibitor at the site of testing selectively attenuated SIEH. Compatible with endothelial cells releasing ATP in response to mechanical stimulation, P2X(2/3) receptor antagonists eliminated SIEH. The endothelium also appears to contribute to hyperalgesia in two ergonomic pain models (eccentric exercise and hindlimb vibration) and in a model of endometriosis. We propose that SIEH is produced by an effect of ET-1 on vascular endothelial cells, sensitizing its release of ATP in response to mechanical stimulation; ATP in turn acts at the nociceptor P2X(2/3) receptor.
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Moldes O, Sobrino T, Blanco M, Agulla J, Barral D, Ramos-Cabrer P, Castillo J. Neuroprotection afforded by antagonists of endothelin-1 receptors in experimental stroke. Neuropharmacology 2012; 63:1279-85. [PMID: 22975409 DOI: 10.1016/j.neuropharm.2012.08.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 07/28/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
Abstract
Endothelin-1 (ET-1) is involved on the development of cerebral edema in acute ischemic stroke. As edema is a therapeutic target in cerebral ischemia, our aim was to study the effect of antagonists for ET-1 receptors (Clazosentan® and BQ-788, specific antagonists for receptors A and B, respectively) on the development of edema, infarct volume and sensorial-motor deficits in rats subjected to ischemia by occlusion of the middle cerebral artery (MCAO). We used Wistar rats (280-320 g) submitted to ischemia by intraluminal transient (90 min) MCAO. After ischemia, rats were randomized into 4 groups (n = 6) treated with; 1) control group (saline), 2) Clazosentan® group (10 mg/kg iv), 3) BQ-788 group (3 mg/kg iv), and 4) combined treatment (Clazosentan® 10 mg/kg plus BQ-788 3 mg/kg iv). We observed that rats treated with Clazosentan® showed a reduction of edema, measured by MRI, at 72 h (hours) and at day 7 (both p < 0.0001), and a decrease in the serum levels of ET-1 at 72 h (p < 0.0001) and at day 7 (p = 0.009). The combined treatment also induced a reduction of edema at 24 h (p = 0.004), 72 h (p < 0.0001) and at day 7 (p < 0.0001), a reduction on infarct volume, measured by MRI, at 24 and 72 h, and at day 7 (all p < 0.01), and a better sensorimotor recovery at 24 and 72 h, and at day 7 (all p < 0.01). Moreover, Clazosentan® induced a decrease in AQP4 expression, while BQ-788 induced an increase in AQP9 expression. These results suggest that antagonists for ET-1 receptors may be a good therapeutic target for cerebral ischemia.
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Affiliation(s)
- Octavio Moldes
- Clinical Neurosciences Research Laboratory, Neurovascular Area, Department of Neurology, Hospital Clínico Universitario, IDIS, University of Santiago de Compostela, Santiago de Compostela, Spain
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Baltatu OC, Iliescu R, Zaugg CE, Reckelhoff JF, Louie P, Schumacher C, Campos LA. Antidiuretic effects of the endothelin receptor antagonist avosentan. Front Physiol 2012; 3:103. [PMID: 22529820 PMCID: PMC3328756 DOI: 10.3389/fphys.2012.00103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 04/02/2012] [Indexed: 01/08/2023] Open
Abstract
Several clinical studies have investigated the potential benefits of endothelin receptor antagonism in chronic pathologies such as diabetic kidney disease. However, fluid retention and edema have been identified as major side effects of endothelin receptor antagonists. In the present study we hypothesized that avosentan which was described as a predominant ETA receptor antagonist would produce fluid retention at high concentrations where non-specific blockade of ETB receptors may occur. Incremental doses of the predominant ETA receptor antagonist SPP301 (0.003; 0.03; 3 mg/kg) were administered intravenously to anesthetized Sprague-Dawley rats undergoing saline diuresis. Diuresis, glomerular filtration rate, and blood pressure (BP) were monitored. SPP301 decreased urine output (5.6; 34.8; 58.8% decrease from vehicle) and fractional excretion of water (5.7; 31.7; 56.4% decrease from vehicle) in a concentration-dependent manner. Glomerular filtration rate was unchanged while BP was reduced by 10 mmHg only by the highest dose of SPP301. Administration of the ETB selective receptor antagonist BQ-788 (3 mg/kg) following SPP301 3 mg/kg did not further decrease urine output or water excretion and was without effect on glomerular filtration rate. These data indicate that increasing concentrations of SPP301 may also block ETB receptors and cause antidiuresis. This effect could explain why fluid retention and edema occur during treatment with predominant ETA receptor blockers.
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Olave N, Nicola T, Zhang W, Bulger A, James M, Oparil S, Chen YF, Ambalavanan N. Transforming growth factor-β regulates endothelin-1 signaling in the newborn mouse lung during hypoxia exposure. Am J Physiol Lung Cell Mol Physiol 2012; 302:L857-65. [PMID: 22287612 DOI: 10.1152/ajplung.00258.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously shown that inhibition of transforming growth factor-β (TGF-β) signaling attenuates hypoxia-induced inhibition of alveolar development and abnormal pulmonary vascular remodeling in the newborn mice and that endothelin-A receptor (ETAR) antagonists prevent and reverse the vascular remodeling. The current study tested the hypothesis that inhibition of TGF-β signaling attenuates endothelin-1 (ET-1) expression and thereby reduces effects of hypoxia on the newborn lung. C57BL/6 mice were exposed from birth to 2 wk of age to either air or hypoxia (12% O(2)) while being given either BQ610 (ETAR antagonist), BQ788 (ETBR antagonist), 1D11 (TGF-β neutralizing antibody), or vehicle. Lung function and development and TGF-β and ET-1 synthesis were assessed. Hypoxia inhibited alveolar development, decreased lung compliance, and increased lung resistance. These effects were associated with increased TGF-β synthesis and signaling and increased ET-1 synthesis. BQ610 (but not BQ788) improved lung function, without altering alveolar development or increased TGF-β signaling in hypoxia-exposed animals. Inhibition of TGF-β signaling reduced ET-1 in vivo, which was confirmed in vitro in mouse pulmonary endothelial, fibroblast, and epithelial cells. ETAR blockade improves function but not development of the hypoxic newborn lung. Reduction of ET-1 via inhibition of TGF-β signaling indicates that TGF-β is upstream of ET-1 during hypoxia-induced signaling in the newborn lung.
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Affiliation(s)
- Nelida Olave
- Department of Pediatrics, Univ. of Alabama at Birmingham, Birmingham, AL 35249, USA
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Bagnato A, Loizidou M, Pflug BR, Curwen J, Growcott J. Role of the endothelin axis and its antagonists in the treatment of cancer. Br J Pharmacol 2011; 163:220-33. [PMID: 21232046 DOI: 10.1111/j.1476-5381.2011.01217.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The endothelins (ET) are a group of proteins that act through G-protein coupled receptors. Endothelin-1 (ET-1) was initially identified as a potent vasoconstrictor and dysregulation of the ET axis contributes to pathological processes responsible for cardiovascular disease states. More recently, the ET axis, in particular ET-1 acting through the endothelin A receptor (ET(A) ), has been implicated in the development of several cancers through activation of pathways involved in cell proliferation, migration, invasion, epithelial-mesenchymal transition, osteogenesis and angiogenesis. The endothelin B receptor (ET(B) ) may counter tumour progression by promoting apoptosis and clearing ET-1; however, it has recently been implicated in the development of some tumour types including melanomas and oligodendrogliomas. Here, we review emerging preclinical and clinical data outlining the role of the ET axis in cancer, and its antagonism as an attractive and challenging approach to improve clinical cancer management. Clinical data of ET(A) antagonists in patients with prostate cancer are encouraging and provide promise for new ET(A) antagonist-based treatment strategies. Given the unexpected opportunities to affect pleiotrophic tumorigenic signals by targeting ET(A)-mediated pathways in a number of cancers, the evaluation of ET-targeted therapy in cancer warrants further investigation.
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Affiliation(s)
- A Bagnato
- Molecular Pathology Laboratory 'A', Regina Elena National Cancer Institute, Rome, Italy
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Sharif NA, Crider JY. Human choroidal melanocyte signal transduction responses to various pharmacological agents: focus on endothelin receptors. Curr Eye Res 2011; 36:462-8. [PMID: 21501081 DOI: 10.3109/02713683.2011.560410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The receptor-coupled signal transduction systems present in isolated human choroidal melanocytes (HCOMs) were investigated. METHODS [(3)H]-inositol phosphates ([(3)H]-IPs) generated in the cells were measured by ion-exchange chromatography. cAMP generated in the cells was quantified using an enzyme immunoassay. RESULTS Initially, HCOM cells were challenged with a relatively high concentration (e.g., 1 µM-1 mM) of a variety of pharmacological agents in order to determine which functional receptors were present in these cells. Full concentration-response pharmacological studies were subsequently conducted on endothelin receptors. While a number of prostaglandins (PGs) (e.g., PGD(2), PGE(2), PGF(2α), cloprostenol, latanoprost acid, U-46619), histamine, carbachol, bombesin, and arginine-vasopressin were essentially inactive at stimulating the phosphoinositide (PI) hydrolysis response, endothelin-1 (ET-1) potently and efficaciously generated [(3)H]-IPs. Concentration-response studies yielded the following potency (EC(50)) and efficacy (E(max) relative to ET-1) data: ET-1 EC(50) = 3.4 ± 1.4 nM, E(max) = 100%, n = 3; BQ-3020 (ET(B) receptor-selective agonist) EC(50) = 13 ± 4 nM, E(max) = 73 ± 2%, n = 3). The effects of ET-1 on [(3)H]-IPs production were blocked by the ET(B) receptor-selective antagonist, BQ-788 (IC(50) = 10 ± 5 nM, n = 3), while the ET(A) receptor-selective antagonist (BQ-610) was essentially inactive. In the adenylyl cyclase (AC) assay, while isoproterenol (10 µM), ET-1 (1 µM) and PGE(2) (10 µM) stimulated cAMP production, numerous other PGs (e.g., PGD(2), PGF(2α), PGI(2), latanoprost, latanoprost acid, U-46619 and BW245C [all at > 10 µM]) were inactive. CONCLUSIONS It is concluded that HCOMs express functionally active ET(B) receptors that mediate the production of [(3)H]-IPs. Additionally, HCOMs generate cAMP in response to ET-1, PGE(2), and isoproterenol. These data may have relevance to the melanogenic activity of HCOM cells.
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Affiliation(s)
- Najam A Sharif
- Pharmaceutical Research, Alcon Research, Ltd., Fort Worth, Texas, USA
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Funke C, Farr M, Werner B, Dittmann S, Überla K, Piper C, Niehaus K, Horstkotte D. Antiviral effect of Bosentan and Valsartan during coxsackievirus B3 infection of human endothelial cells. J Gen Virol 2010; 91:1959-1970. [DOI: 10.1099/vir.0.020065-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In viral myocarditis, adeno- and enteroviruses have most commonly been implicated as causes of infection. Both viruses require the human coxsackie-adenovirus receptor (CAR) to infect the myocardium. Due to its crucial role for viral entry, CAR-downregulation may lead to novel approaches for treatment for viral myocarditis. In this study, we report on pharmaceutical drug influences on CAR levels in human umbilical vein endothelial cells (HUVEC) and cervical carcinoma cells (HeLa) detected by immunoblotting, quantitative real time-PCR and cellular susceptibility to the cardiotropic coxsackie-B3 virus strain Nancy (CVB3). Our results indicate, for the first time, a dose-dependent CAR mRNA and protein downregulation upon Valsartan and Bosentan treatment. Most interestingly, drug-induced CAR diminution significantly reduced the viral load in CVB3-infected HUVEC. In order to assess the regulatory effects of both drugs in detail, we knocked down their protein targets, the G-protein coupled receptors angiotensin-II type-1 receptor (AT1R) and endothelin-1 type-A and -B receptors (ETAR/ETBR) in HUVEC. Receptor-specific gene silencing indicates that CAR gene expression is regulated by agonistic and antagonistic binding to ETBR, but not ETAR. In addition, neither stimulation nor inhibition of AT1R seemed to be involved in CAR gene regulatory processes. Our study indicates that Valsartan and Bosentan protected human endothelial cells from CVB3-infection. Therefore, besides their well-known anti-hypertensive effects these drugs may also protect the myocardium and other tissues from coxsackie- and adenoviral infection.
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Affiliation(s)
- Carsten Funke
- Department of Cardiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Georgstr. 11, 32545 Bad Oeynhausen, NRW, Germany
| | - Martin Farr
- Department of Cardiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Georgstr. 11, 32545 Bad Oeynhausen, NRW, Germany
| | - Bianca Werner
- Department of Cardiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Georgstr. 11, 32545 Bad Oeynhausen, NRW, Germany
| | - Sven Dittmann
- Department of Cardiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Georgstr. 11, 32545 Bad Oeynhausen, NRW, Germany
| | - Klaus Überla
- Department of Molecular and Medical Virology, Ruhr University of Bochum, Universitätsstr. 150, 44801 Bochum, NRW, Germany
| | - Cornelia Piper
- Department of Cardiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Georgstr. 11, 32545 Bad Oeynhausen, NRW, Germany
| | - Karsten Niehaus
- Center for Biotechnology (CeBiTec), Bielefeld University, Universitätsstr. 27, 33615 Bielefeld, NRW, Germany
| | - Dieter Horstkotte
- Department of Cardiology, Heart and Diabetes Center NRW, Ruhr University of Bochum, Georgstr. 11, 32545 Bad Oeynhausen, NRW, Germany
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Scriabine A, Rabin DU. New Developments in the Therapy of Pulmonary Fibrosis. ADVANCES IN PHARMACOLOGY 2009; 57:419-64. [DOI: 10.1016/s1054-3589(08)57011-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Nitescu N, Grimberg E, Herlitz H, Guron G. ROLE OF ENDOTHELIN ETAAND ETBRECEPTOR SUBTYPES IN THE REGULATION OF INTRARENAL BLOOD FLOW AND OXYGEN TENSION IN RATS. Clin Exp Pharmacol Physiol 2008; 35:1227-32. [DOI: 10.1111/j.1440-1681.2008.04977.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nitescu N, Grimberg E, Ricksten SE, Herlitz H, Guron G. Endothelin B receptors preserve renal blood flow in a normotensive model of endotoxin-induced acute kidney dysfunction. Shock 2008; 29:402-9. [PMID: 17693943 DOI: 10.1097/shk.0b013e3181454118] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim was to investigate the role of endothelin 1 receptor subtypes in the early renal response to lipopolysaccharide (LPS) during normotensive endotoxemia with acute kidney dysfunction. Endotoxemia was induced in thiobutabarbital-anesthetized rats (n = 9 per group) by infusion of LPS (dosage, 1 mg/kg per hour i.v.). The study groups (1) sham-saline, (2) LPS-saline, (3) LPS-BQ123, (4) LPS-BQ788 and (5) LPS-BQ123 + BQ788 received isotonic saline, the ETA receptor antagonist BQ-123 (dosage, 30 nmol/kg per minute i.v.), and/or the ETB receptor antagonist BQ-788 (dosage, 30 nmol/kg per minute i.v.) before and during 2 h of LPS infusion. Renal clearance measurements, renal blood flow (RBF), and cortical and outer medullary perfusion (laser-Doppler flowmetry) and oxygen tension (Clark-type microelectrodes) were analyzed throughout. Before LPS administration, there were no significant differences between groups in glomerular filtration rate (GFR), RBF, or in cortical (CLDF) and outer medullary perfusion. However, mean arterial pressure (MAP) was elevated in LPS-BQ788 group compared with LPS-BQ123 + BQ788 group (P < 0.05). In saline-treated rats, endotoxin induced an approximate 35% reduction in GFR (P < 0.05), without significant effects on MAP, RBF, or on CLDF and cortical PO2. In addition, LPS increased outer medullary perfusion and PO2 (P < 0.05). The fractional urinary excretion rates of sodium, potassium, and water were not significantly different in LPS-saline group compared with sham-saline group. Neither selective nor combined ETA and ETB receptor blockade improved GFR. In BQ-788-infused rats, endotoxin produced marked reductions in RBF (-18% +/- 4% [P < 0.05]) and CLDF (-18% +/- 2% [P < 0.05]). Similarly, endotoxin decreased RBF (-14% +/- 3% [P < 0.05]) and CLDF (-10% +/- 2% [P < 0.05]) in LPS-BQ123 + BQ788 group. Endotoxin reduced MAP (-22% +/- 4% [P < 0.05]) in BQ-123-treated rats but did not significantly influence MAP in other groups. We conclude that in early normotensive endotoxemia, ETB receptors exert a renal vasodilator influence and contribute to maintain normal RBF.
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Affiliation(s)
- Nicoletta Nitescu
- Department of Anesthesiology and Intensive Care, Institute of Clinical Sciences, The Sahlgrenska Academy at Göteborg University, Sweden.
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Rajeshkumar NV, Matwyshyn G, Gulati A. IRL-1620, a tumor selective vasodilator, augments the uptake and efficacy of chemotherapeutic agents in prostate tumor rats. Prostate 2007; 67:701-13. [PMID: 17342753 DOI: 10.1002/pros.20556] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND IRL-1620, a potent endothelin B receptor agonist, enhanced the efficacy of paclitaxel in a breast tumor model, but its effect in prostate cancer is not known. The present study was conducted to evaluate the effect of IRL-1620 on tumor perfusion, uptake of [(14)C]-doxorubicin in the tumor and efficacy of doxorubicin (DOX), and 5-flurouracil (5-FU) in a rat prostate tumor model. METHODS JHU-4 (Mat-Lu) cells inoculated prostate tumor model in Copenhagen rats was used for the study. RESULTS Administration of IRL-1620 (3 nmol/kg, i.v) significantly increased (102.8%) prostate tumor perfusion and tumor uptake of [(14)C]-doxorubicin (115%) compared to vehicle treated rats. Results of the efficacy study demonstrate that IRL-1620 administration 15 min prior to DOX (5 mg/kg) or 5-FU (50 mg/kg) on every third day for a total of four doses significantly reduced tumor volume compared to vehicle treated rats. CONCLUSIONS IRL-1620 significantly enhanced the uptake and efficacy of anticancer agents in prostate cancer.
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Affiliation(s)
- N V Rajeshkumar
- Department of Biopharmaceutical Sciences, University of Illinois, Chicago, Illinois, USA
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Rajeshkumar NV, Rai A, Gulati A. Endothelin B receptor agonist, IRL 1620, enhances the anti-tumor efficacy of paclitaxel in breast tumor rats. Breast Cancer Res Treat 2005; 94:237-47. [PMID: 16244791 DOI: 10.1007/s10549-005-9000-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Pharmacological agents that increase tumor blood flow could be utilized to promote the delivery of anti-cancer drugs. We have demonstrated that administration of endothelin-1 (ET-1) to breast tumor bearing rats transiently increased tumor blood flow by stimulating endothelin B (ET(B)) receptors. The present study evaluated the effect of ET(B) receptor agonist, IRL 1620, on breast tumor perfusion, concentration of [3H]paclitaxel in tumor and tissues, and efficacy of paclitaxel in N-methyl nitrosourea induced breast tumor bearing rats. Administration of IRL 1620 (3 and 9 nmol/kg) significantly increased (203 and 140%, respectively) breast tumor perfusion. BQ 788, an ET(B) receptor antagonist, pretreatment completely abolished IRL 1620 induced increase in tumor perfusion. Tumor [3H]paclitaxel concentration was increased by 308% when [3H]paclitaxel was administered 15 min after IRL 1620 (3 nmol/kg) compared to vehicle treated rats. However, IRL 1620 did not increase [3H]paclitaxel concentrations in other organs. Efficacy study showed that paclitaxel (5 mg/kg) administration on every third day for a total of five doses produced 60.0, 4.5 and 0% reduction in tumor volume, tumor progression and complete tumor remission, respectively, compared to saline treated rats. However, paclitaxel (5 mg/kg) when administered 15 min after IRL 1620 (3 nmol/kg) produced 268.9, 210.3 and 20% reduction in tumor volume, tumor progression and complete remission of tumors, respectively, compared to saline treated rats. In conclusion, IRL 1620 significantly enhanced delivery and effectiveness of paclitaxel in an animal model of breast cancer.
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Affiliation(s)
- N V Rajeshkumar
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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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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Brosseau JP, D'Orléans-Juste P, Neugebauer WA. Development of an efficient strategy for the synthesis of the ETB receptor antagonist BQ-788 and some related analogues. Peptides 2005; 26:1441-53. [PMID: 16042984 DOI: 10.1016/j.peptides.2005.03.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BQ-788 [N-cis-2,6-dimethylpiperidine-1-carbonyl-L-gamma-methylleucyl-D-1-methoxycarbonyltryptophanyl-D-norleucine sodium salt] is a very potent and selective ETB receptor antagonist. The formation of the highly hindered trisubstituted urea functionality in the peptide chain and the carbamination on the indole nitrogen of the tryptophan side chain are major challenges in the synthesis of this particular antagonist. Furthermore, the high cost of the unnatural amino acids in the sequence of BQ-788 and its reported synthesis render this pseudopeptide very expensive to produce. In order to improve the yield and to reduce the number of steps compared to previous reported syntheses, we developed an efficient strategy involving a novel one-pot procedure for the synthesis of a highly hindered trisubstituted urea. Under very mild conditions, the urea was obtained by using triphosgene and sodium iodide. This strategy allowed us to synthesize BQ-788 in seven steps with an overall yield of 53%. We also generalized the use of this powerful methodology by creating some new structural analogues of the cis-2,6-dimethylpiperidine moiety by replacing it with other bulky secondary amines. We evaluated the antagonist properties of those three new analogues of BQ-788 in two bioassays in vitro. These new antagonists were less potent than BQ-788 in an ETB rich preparation and inactive in an ETA rich preparation.
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Affiliation(s)
- Jean-Philippe Brosseau
- Department of Pharmacology, IPS, Medical School, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4
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Hardwick JS, Yang Y, Zhang C, Shi B, McFall R, Koury EJ, Hill SL, Dai H, Wasserman R, Phillips RL, Weinstein EJ, Kohl NE, Severino ME, Lamb JR, Sepp-Lorenzino L. Identification of biomarkers for tumor endothelial cell proliferation through gene expression profiling. Mol Cancer Ther 2005; 4:413-25. [PMID: 15767550 DOI: 10.1158/1535-7163.mct-04-0209] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Extensive efforts are under way to identify antiangiogenic therapies for the treatment of human cancers. Many proposed therapeutics target vascular endothelial growth factor (VEGF) or the kinase insert domain receptor (KDR/VEGF receptor-2/FLK-1), the mitogenic VEGF receptor tyrosine kinase expressed by endothelial cells. Inhibition of KDR catalytic activity blocks tumor neoangiogenesis, reduces vascular permeability, and, in animal models, inhibits tumor growth and metastasis. Using a gene expression profiling strategy in rat tumor models, we identified a set of six genes that are selectively overexpressed in tumor endothelial cells relative to tumor cells and whose pattern of expression correlates with the rate of tumor endothelial cell proliferation. In addition to being potential targets for antiangiogenesis tumor therapy, the expression patterns of these genes or their protein products may aid the development of pharmacodynamic assays for small molecule inhibitors of the KDR kinase in human tumors.
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Affiliation(s)
- James S Hardwick
- Merck & Co., Inc., 770 Sumneytown Pike, WP26-462, West Point, PA 19486, USA.
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Katz LM, Marr CM, Elliott J. Characterization and comparison of the responses of equine digital arteries and veins to endothelin-1. Am J Vet Res 2003; 64:1438-43. [PMID: 14620782 DOI: 10.2460/ajvr.2003.64.1438] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare the responses of equine digital arteries (EDAs) and equine digital veins (EDVs) to endothelin-1 (ET-1) and determine the role of the endothelium and type of receptors involved in the modulation and mediation of those responses, respectively. SAMPLE POPULATION 5 to 9 palmar digital vessels/experiment from 28 healthy horses. PROCEDURE Rings of dissected vessels were mounted under tension between force transducer wires in organ baths containing Krebs-Henseleit solution at 30 degrees C. Responses of EDAs and EDVs (with intact [+e] or denuded [-e] endothelium) to cumulative concentrations of ET-1 (10(-10) to 3 X 10(-7) M) were compared. For (+e)EDAs and (+e)EDVs precontracted with a thromboxane-mimetic (U44069; 10(-8) M) and (-e)EDAs and (-e)EDVs, responses to an ETB receptor agonist (S6c; 10(-10) to 3 X 10(-7) M) were evaluated. Responses to ET-1 (10(-7) M) in (-e)EDAs and (-e)EDVs were evaluated after incubation with an ETA receptor antagonist (BQ-123; 3 X 10(-7) M), an ETB receptor antagonist (BQ-788; 3 X 10(-7) M), or vehicle solution. RESULTS Endothelin-1 induced a concentration-dependent contraction of endothelium-intact and -denuded EDAs and EDVs; EDVs were more sensitive. Neither vessel type relaxed in response to S6c, although 2 of the (-e)EDAs contracted mildly. Whereas BQ-123 inhibited the (-e)EDA and (-e)EDV responses to ET-1, BQ-788 had no effect. CONCLUSIONS AND CLINICAL RELEVANCE Endothelin-1 induced digital vasoconstriction (marked constriction in veins). This action was unaffected by endothelium and mediated predominantly by ETA receptors. These findings suggest ET-1 can induce selective digital venoconstriction.
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Affiliation(s)
- Lisa M Katz
- Department of Veterinary Clinical Sciences, University of London, The Royal Veterinary College, North Mymms, Hertfordshire AL9 7TA, United Kingdom
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Ding KH, Zhong Q, Isales CM. Glucose-dependent insulinotropic peptide stimulates thymidine incorporation in endothelial cells: role of endothelin-1. Am J Physiol Endocrinol Metab 2003; 285:E390-6. [PMID: 12721154 DOI: 10.1152/ajpendo.00509.2002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously characterized the receptor for glucose-dependent insulinotropic polypeptide (GIPR) in vascular endothelial cells (EC). Different EC types were found to contain distinct GIPR splice variants. To determine whether activation of the GIPR splice variants resulted in different cellular responses, we examined GIP effects on human umbilical vein endothelial cells (HUVEC), which contain two GIPR splice variants, and compared them with a spontaneously transformed human umbilical vein EC line, ECV 304, which contains four GIPR splice variants. GIP dose-dependently stimulated HUVEC and ECV 304 proliferation as measured by [3H]thymidine incorporation. GIP increased endothelin-1 (ET-1) secretion from HUVEC but not from ECV 304. Use of the endothelin B receptor blocker BQ-788 resulted in an inhibition of [3H]thymidine incorporation in HUVEC but not in ECV 304. These findings suggest that, although GIP increases [3H]thymidine incorporation in both HUVEC and ECV 304, this proliferative response is mediated by ET-1 only in HUVEC. These differences in cellular response to GIP may be related to differences in activation of GIPR splice variants.
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Affiliation(s)
- Ke-Hong Ding
- Institute of Molecular Medicine and Genetics, Dept. of Medicine, Medical College of Georgia, 120 15th St., Augusta, GA 30912, USA
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