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Xu N, Ayers L, Pastukh V, Alexeyev M, Stevens T, Tambe DT. Impact of Na+ permeation on collective migration of pulmonary arterial endothelial cells. PLoS One 2021; 16:e0250095. [PMID: 33891591 PMCID: PMC8064576 DOI: 10.1371/journal.pone.0250095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/30/2021] [Indexed: 11/19/2022] Open
Abstract
Collective migration of endothelial cells is important for wound healing and angiogenesis. During such migration, each constituent endothelial cell coordinates its magnitude and direction of migration with its neighbors while retaining intercellular adhesion. Ensuring coordination and cohesion involves a variety of intra- and inter-cellular signaling processes. However, the role of permeation of extracellular Na+ in collective cell migration remains unclear. Here, we examined the effect of Na+ permeation in collective migration of pulmonary artery endothelial cell (PAEC) monolayers triggered by either a scratch injury or a barrier removal over 24 hours. In the scratch assay, PAEC monolayers migrated in two approximately linear phases. In the first phase, wound closure started with fast speed which then rapidly reduced within 5 hours after scratching. In the second phase, wound closure maintained at slow and stable speed from 6 to 24 hours. In the absence of extracellular Na+, the wound closure distance was reduced by >50%. Fewer cells at the leading edge protruded prominent lamellipodia. Beside transient gaps, some sustained interendothelial gaps also formed and progressively increased in size over time, and some fused with adjacent gaps. In the absence of both Na+ and scratch injury, PAEC monolayer migrated even more slowly, and interendothelial gaps obviously increased in size towards the end. Pharmacological inhibition of the epithelial Na+ channel (ENaC) using amiloride reduced wound closure distance by 30%. Inhibition of both the ENaC and the Na+/Ca2+ exchanger (NCX) using benzamil further reduced wound closure distance in the second phase and caused accumulation of floating particles in the media. Surprisingly, pharmacological inhibition of the Ca2+ release-activated Ca2+ (CRAC) channel protein 1 (Orai1) using GSK-7975A, the transient receptor potential channel protein 1 and 4 (TRPC1/4) using Pico145, or both Orai1 and TRPC1/4 using combined GSK-7975A and Pico145 treatment did not affect wound closure distance dramatically. Nevertheless, the combined treatment appeared to cause accumulation of floating particles. Note that GSK-7975A also inhibits small inward Ca2+ currents via Orai2 and Orai3 channels, whereas Pico145 also blocks TRPC4, TRPC5, and TRPC1/5 channels. By contrast, gene silence of Orai1 by shRNAs led to a 25% reduction of wound closure in the first 6 hours but had no effect afterwards. However, in the absence of extracellular Na+ or cellular injury, Orai1 did not affect PAEC collective migration. Overall, the data reveal that Na+ permeation into cells contributes to PAEC monolayer collective migration by increasing lamellipodial formation, reducing accumulation of floating particles, and improving intercellular adhesion.
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Affiliation(s)
- Ningyong Xu
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
| | - Linn Ayers
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
| | - Viktoriya Pastukh
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
| | - Mikhail Alexeyev
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Departments of Internal Medicine, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
| | - Troy Stevens
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Departments of Internal Medicine, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail: (DTT); (TS)
| | - Dhananjay T. Tambe
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Departments of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Department of Mechanical, Aerospace, and Biomedical Engineering, College of Engineering, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail: (DTT); (TS)
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Abstract
PURPOSE OF REVIEW The main goal of this article is to discuss the role of the epithelial sodium channel (ENaC) in extracellular fluid and blood pressure regulation. RECENT FINDINGS Besides its role in sodium handling in the kidney, recent studies have found that ENaC expressed in other cells including immune cells can influence blood pressure via extra-renal mechanisms. Dendritic cells (DCs) are activated and contribute to salt-sensitive hypertension in an ENaC-dependent manner. We discuss recent studies on how ENaC is regulated in both the kidney and other sites including the vascular smooth muscles, endothelial cells, and immune cells. We also discuss how this extra-renal ENaC can play a role in salt-sensitive hypertension and its promise as a novel therapeutic target. The role of ENaC in blood pressure regulation in the kidney has been well studied. Recent human gene sequencing efforts have identified thousands of variants among the genes encoding ENaC, and research efforts to determine if these variants and their expression in extra-renal tissue play a role in hypertension will advance our understanding of the pathogenesis of ENaC-mediated cardiovascular disease and lead to novel therapeutic targets.
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Affiliation(s)
- Ashley L Pitzer
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, 2215 Garland Avenue, P415C Medical Research Building IV, Nashville, TN, 37232, USA
| | - Justin P Van Beusecum
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, 2215 Garland Avenue, P415C Medical Research Building IV, Nashville, TN, 37232, USA
| | - Thomas R Kleyman
- Departments of Medicine, Cell Biology, Pharmacology, and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, 2215 Garland Avenue, P415C Medical Research Building IV, Nashville, TN, 37232, USA. .,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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Mutchler SM, Kleyman TR. New insights regarding epithelial Na+ channel regulation and its role in the kidney, immune system and vasculature. Curr Opin Nephrol Hypertens 2019; 28:113-119. [PMID: 30585851 PMCID: PMC6349474 DOI: 10.1097/mnh.0000000000000479] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW This review describes recent findings regarding the epithelial Na channel (ENaC) and its roles in physiologic and pathophysiologic states. We discuss new insights regarding ENaC's structure, its regulation by various factors, its potential role in hypertension and nephrotic syndrome, and its roles in the immune system and vasculature. RECENT FINDINGS A recently resolved structure of ENaC provides clues regarding mechanisms of ENaC activation by proteases. The use of amiloride in nephrotic syndrome, and associated complications are discussed. ENaC is expressed in dendritic cells and contributes to immune system activation and increases in blood pressure in response to NaCl. ENaC is expressed in endothelial ENaC and has a role in regulating vascular tone. SUMMARY New findings have emerged regarding ENaC and its role in the kidney, immune system, and vasculature.
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Affiliation(s)
- Stephanie M. Mutchler
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA
| | - Thomas R. Kleyman
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA
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Ydegaard R, Andersen H, Oxlund CS, Jacobsen IA, Hansen PBL, Jürgensen JF, Peluso AA, Vanhoutte PM, Staehr M, Svenningsen P, Jensen BL. The acute blood pressure-lowering effect of amiloride is independent of endothelial ENaC and eNOS in humans and mice. Acta Physiol (Oxf) 2019; 225:e13189. [PMID: 30240139 DOI: 10.1111/apha.13189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 09/11/2018] [Accepted: 09/17/2018] [Indexed: 01/15/2023]
Abstract
AIMS The epithelial sodium channel (ENaC) is expressed in cultured endothelial cells and inhibitory coupling to eNOS activity has been proposed. The present study tested the hypothesis that ENaC blockers increase systemic NO-products and lower blood pressure in patients and mice, depending on eNOS. METHODS NO-products and cGMP were measured in diabetes patient urine and plasma samples before and after amiloride treatment (20-40 mg for two days, plasma n = 22, urine n = 12 and 5-10 mg for eight weeks, plasma n = 52, urine n = 55). Indwelling catheters were implanted in the femoral artery and vein in mice for continuous arterial blood pressure and heart rate recordings and infusion. RESULTS Treatment with amiloride for two days increased plasma and urine NO-products, while plasma cGMP decreased and urinary cGMP was unchanged in patient samples. Eight weeks of treatment with amiloride did not alter NO-products and cGMP. In mice, amiloride boli of 5, 50, and 500 µg/kg lowered heart rate and arterial blood pressure significantly and acutely. Benzamil had no effect on pressure and raised heart rate. In hypertensive eNOS-/- and L-NAME-treated mice, amiloride lowered blood pressure significantly. L-NAME infusion significantly decreased NO-products in plasma; amiloride and eNOS-deletion had no effect. An acetylcholine bolus resulted in acute blood pressure drop that was attenuated in eNOS-/- and L-NAME mice. ENaC subunit expressions were not detected consistently in human and mouse arteries and endothelial cells. CONCLUSION Amiloride has an acute hypotensive action not dependent on ENaC and eNOS and likely related to the heart.
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Affiliation(s)
- Rikke Ydegaard
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Henrik Andersen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | | | - Ib A. Jacobsen
- Department of Endocrinology; Odense University Hospital; Odense Denmark
| | - Pernille B. L. Hansen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
- Cardiovascular and Metabolic Disease, IMED Biotech Unit; AstraZeneca; Gothenburg Sweden
| | - Jonathan F. Jürgensen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Antonio Augusto Peluso
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Paul M. Vanhoutte
- Department of Pharmacology and Pharmacy; Hong Kong University; China
| | - Mette Staehr
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Per Svenningsen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Boye L. Jensen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
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Ashley Z, Mugloo S, McDonald FJ, Fronius M. Epithelial Na + channel differentially contributes to shear stress-mediated vascular responsiveness in carotid and mesenteric arteries from mice. Am J Physiol Heart Circ Physiol 2018; 314:H1022-H1032. [PMID: 29373035 DOI: 10.1152/ajpheart.00506.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A potential "new player" in arteries for mediating shear stress responses is the epithelial Na+ channel (ENaC). The contribution of ENaC as shear sensor in intact arteries, and particularly different types of arteries (conduit and resistance), is unknown. We investigated the role of ENaC in both conduit (carotid) and resistance (third-order mesenteric) arteries isolated from C57Bl/6J mice. Vessel characteristics were determined at baseline (60 mmHg, no flow) and in response to increased intraluminal pressure and shear stress using a pressure myograph. These protocols were performed in the absence and presence of the ENaC inhibitor amiloride (10 µM) and after inhibition of endothelial nitric oxide synthase (eNOS) by Nω-nitro-l-arginine methyl ester (l-NAME; 100 µM). Under no-flow conditions, amiloride increased internal and external diameters of carotid (13 ± 2%, P < 0.05) but not mesenteric (0.5 ± 0.9%, P > 0.05) arteries. In response to increased intraluminal pressure, amiloride had no effect on the internal diameter of either type of artery. However, amiloride affected the stress-strain curves of mesenteric arteries. With increased shear stress, ENaC-dependent effects were observed in both arteries. In carotid arteries, amiloride augmented flow-mediated dilation (9.2 ± 5.3%) compared with control (no amiloride, 6.2 ± 3.3%, P < 0.05). In mesenteric arteries, amiloride induced a flow-mediated constriction (-11.5 ± 6.6%) compared with control (-2.2 ± 4.5%, P < 0.05). l-NAME mimicked the effect of ENaC inhibition and prevented further amiloride effects in both types of arteries. These observations indicate that ENaC contributes to shear sensing in conduit and resistance arteries. ENaC-mediated effects were associated with NO production but may involve different (artery-dependent) downstream signaling pathways. NEW & NOTEWORTHY The epithelial Na+ channel (ENaC) contributes to shear sensing in conduit and resistance arteries. In conduit arteries ENaC has a role as a vasoconstrictor, whereas in resistance arteries ENaC contributes to vasodilation. Interaction of ENaC with endothelial nitric oxide synthase/nitric oxide signaling to mediate the effects is supported; however, cross talk with other shear stress-dependent signaling pathways cannot be excluded.
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Affiliation(s)
- Zoe Ashley
- Department of Physiology, University of Otago , Dunedin , New Zealand.,HeartOtago, University of Otago , Dunedin , New Zealand
| | - Sama Mugloo
- Department of Physiology, University of Otago , Dunedin , New Zealand.,HeartOtago, University of Otago , Dunedin , New Zealand
| | - Fiona J McDonald
- Department of Physiology, University of Otago , Dunedin , New Zealand
| | - Martin Fronius
- Department of Physiology, University of Otago , Dunedin , New Zealand.,HeartOtago, University of Otago , Dunedin , New Zealand
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陈 珺, 谢 芳, 林 鑫, 林 思, 杨 国, 卢 丽, 陆 幸, 李 青. [Effects of aldosterone on osteoblast proliferation, differentiation and osteogenic gene expressions in vitro]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2017; 37:1489-1493. [PMID: 29180329 PMCID: PMC6779641 DOI: 10.3969/j.issn.1673-4254.2017.11.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To study the effect of aldosterone on cell proliferation, alkaline phosphatase (AKP) activity and osteogenic gene expression in rat osteoblasts and explore the mechanisms. METHODS Osteoblasts isolated from the skull of neonatal SD rats by enzyme digestion were cultured and treated with different concentrations of aldosterone. The cell proliferation and AKP activity were evaluated using CCK-8 assay kit and AKP assay kit, respectively. The effects of aldosterone on mRNA and protein expressions of the osteogenic genes and epithelial sodium channel (ENaC) gene were investigated using semi-quantitative PCR and Western blotting. RESULTS Compared with the control cells, the cells treated with 0.01-1.0 µmol/L aldosterone showed obviously enhanced proliferation while lower (1×10-3 µmol/L) or higher (10 µmol/L) concentrations of aldosterone did not significantly affect the cell proliferation. Aldosterone within the concentration range of 1×10-3 to 10 µmol/L did not cause significant changes in AKP activity in the osteoblasts. Treatment with 0.01 to 1.0 µmol/L aldosterone significantly upregulated the expressions of the osteogenic genes and α-ENaC gene at both the mRNA and protein levels. CONCLUSION Aldosterone within the concentration range of 0.01-1.0 µmol/L stimulates the proliferation and osteogenic gene expressions and enhances α-ENaC gene expression in rat osteoblasts in vitro, suggesting the possibility that ENaC participates in aldosterone-mediated regulation of osteoblast functions.
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Affiliation(s)
- 珺 陈
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
- 广东药科大学 生物资源与创新药物研究中心,广东 广州 510006Center for Bioresources and Drug Discovery, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 芳梅 谢
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 鑫 林
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 思慧 林
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 国柱 杨
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 丽 卢
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 幸妍 陆
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - 青南 李
- 广东药科大学 生命科学与生物制药学院,广东 广州 510006School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
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Liu HB, Zhang J, Sun YY, Li XY, Jiang S, Liu MY, Shi J, Song BL, Zhao D, Ma HP, Zhang ZR. Dietary salt regulates epithelial sodium channels in rat endothelial cells: adaptation of vasculature to salt. Br J Pharmacol 2015; 172:5634-46. [PMID: 25953733 DOI: 10.1111/bph.13185] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 04/03/2015] [Accepted: 04/26/2015] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE The epithelial sodium channel (ENaC) is expressed in vascular endothelial cells and is a negative modulator of vasodilation. However, the role of endothelial ENaCs in salt-sensitive hypertension remains unclear. Here, we have investigated how endothelial ENaCs in Sprague-Dawley (SD) rats respond to high-salt (HS) challenge. EXPERIMENTAL APPROACH BP and plasma aldosterone levels were measured. We used patch-clamp technique to record ENaC activity in split-open mesenteric arteries (MAs). Western blot and Griess assay were used to detect expression of α-ENaCs, eNOS and NO. Vasorelaxation in second-order MAs was measured with wire myograph assays. KEY RESULTS Functional ENaCs were observed in endothelial cells and their activity was significantly decreased after 1 week of HS diet. After 3 weeks of HS diet, ENaC expression was also reduced. When either ENaC activity or expression was reduced, endothelium-dependent relaxation (EDR) of MAs, in response to ACh, was enhanced. This enhancement of EDR was mimicked by amiloride, a blocker of ENaCs. By contrast, HS diet significantly increased contractility of MAs, accompanied by decreased eNOS activity and NO levels. However, ACh-induced release of NO was much higher in MAs isolated from HS rats than those from NS rats. CONCLUSIONS AND IMPLICATIONS HS intake increased the BP of SD rats, but simultaneously enhanced EDR by reducing ENaC activity and expression due to feedback inhibition. Therefore, ENaCs may play an important role in endothelial cells allowing the vasculature to adapt to HS conditions.
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Affiliation(s)
- Hui-Bin Liu
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jun Zhang
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ying-Ying Sun
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xin-Yuan Li
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Shuai Jiang
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Yu Liu
- Department of Pharmacology, Harbin Medical University, Harbin, China
| | - Jing Shi
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bin-Lin Song
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Dan Zhao
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Zhi-Ren Zhang
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
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Deliyanti D, Armani R, Casely D, Figgett WA, Agrotis A, Wilkinson-Berka JL. Retinal vasculopathy is reduced by dietary salt restriction: involvement of Glia, ENaCα, and the renin-angiotensin-aldosterone system. Arterioscler Thromb Vasc Biol 2014; 34:2033-41. [PMID: 25012132 DOI: 10.1161/atvbaha.114.303792] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Neovascularization and vaso-obliteration are vision-threatening events that develop by interactions between retinal vascular and glial cells. A high-salt diet is causal in cardiovascular and renal disease, which is linked to modulation of the renin-angiotensin-aldosterone system. However, it is not known whether dietary salt influences retinal vasculopathy and if the renin-angiotensin-aldosterone system is involved. We examined whether a low-salt (LS) diet influenced vascular and glial cell injury and the renin-angiotensin-aldosterone system in ischemic retinopathy. APPROACH AND RESULTS Pregnant Sprague Dawley rats were fed LS (0.03% NaCl) or normal salt (0.3% NaCl) diets, and ischemic retinopathy was induced in the offspring. An LS diet reduced retinal neovascularization and vaso-obliteration, the mRNA and protein levels of the angiogenic factors, vascular endothelial growth factor, and erythropoietin. Microglia, which influence vascular remodeling in ischemic retinopathy, were reduced by LS as was tumor necrosis factor-α. Macroglial Müller cells maintain the integrity of the blood-retinal barrier, and in ischemic retinopathy, LS reduced their gliosis and also vascular leakage. In retina, LS reduced mineralocorticoid receptor, angiotensin type 1 receptor, and renin mRNA levels, whereas, as expected, plasma levels of aldosterone and renin were increased. The aldosterone/mineralocorticoid receptor-sensitive epithelial sodium channel alpha (ENaCα), which is expressed in Müller cells, was increased in ischemic retinopathy and reduced by LS. In cultured Müller cells, high salt increased ENaCα, which was prevented by mineralocorticoid receptor and angiotensin type 1 receptor blockade. Conversely, LS reduced ENaCα, angiotensin type 1 receptor, and mineralocorticoid receptor expression. CONCLUSIONS An LS diet reduced retinal vasculopathy, by modulating glial cell function and the retinal renin-angiotensin-aldosterone system.
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Affiliation(s)
- Devy Deliyanti
- From the Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia (D.D., R.A., W.A.F., A.A., J.L.W.-B.); and Prosearch International, Malvern, Victoria, Australia (D.C.)
| | - Roksana Armani
- From the Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia (D.D., R.A., W.A.F., A.A., J.L.W.-B.); and Prosearch International, Malvern, Victoria, Australia (D.C.)
| | - David Casely
- From the Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia (D.D., R.A., W.A.F., A.A., J.L.W.-B.); and Prosearch International, Malvern, Victoria, Australia (D.C.)
| | - William A Figgett
- From the Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia (D.D., R.A., W.A.F., A.A., J.L.W.-B.); and Prosearch International, Malvern, Victoria, Australia (D.C.)
| | - Alex Agrotis
- From the Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia (D.D., R.A., W.A.F., A.A., J.L.W.-B.); and Prosearch International, Malvern, Victoria, Australia (D.C.)
| | - Jennifer L Wilkinson-Berka
- From the Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia (D.D., R.A., W.A.F., A.A., J.L.W.-B.); and Prosearch International, Malvern, Victoria, Australia (D.C.).
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Warnock DG, Kusche-Vihrog K, Tarjus A, Sheng S, Oberleithner H, Kleyman TR, Jaisser F. Blood pressure and amiloride-sensitive sodium channels in vascular and renal cells. Nat Rev Nephrol 2014; 10:146-57. [PMID: 24419567 DOI: 10.1038/nrneph.2013.275] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sodium transport in the distal nephron is mediated by epithelial sodium channel activity. Proteolytic processing of external domains and inhibition with increased sodium concentrations are important regulatory features of epithelial sodium channel complexes expressed in the distal nephron. By contrast, sodium channels expressed in the vascular system are activated by increased external sodium concentrations, which results in changes in the mechanical properties and function of endothelial cells. Mechanosensitivity and shear stress affect both epithelial and vascular sodium channel activity. Guyton's hypothesis stated that blood pressure control is critically dependent on vascular tone and fluid handling by the kidney. The synergistic effects, and complementary regulation, of the epithelial and vascular systems are consistent with the Guytonian model of volume and blood pressure regulation, and probably reflect sequential evolution of the two systems. The integration of vascular tone, renal perfusion and regulation of renal sodium reabsorption is the central underpinning of the Guytonian model. In this Review, we focus on the expression and regulation of sodium channels, and we outline the emerging evidence that describes the central role of amiloride-sensitive sodium channels in the efferent (vascular) and afferent (epithelial) arms of this homeostatic system.
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Affiliation(s)
- David G Warnock
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, AL 34294-0007, USA
| | - Kristina Kusche-Vihrog
- Institut für Physiologie II, Westfälische Wilhelms Universität, Robert-Koch-Straße 27, 48149 Münster, Germany
| | - Antoine Tarjus
- INSERM U872 Team 1, Centre de Recherche des Cordeliers, Université René Descartes, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Shaohu Sheng
- Renal and Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Hans Oberleithner
- Institut für Physiologie II, Westfälische Wilhelms Universität, Robert-Koch-Straße 27, 48149 Münster, Germany
| | - Thomas R Kleyman
- Renal and Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Frederic Jaisser
- INSERM U872 Team 1, Centre de Recherche des Cordeliers, Université René Descartes, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75006 Paris, France
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11
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Oberleithner H. Vascular endothelium: a vulnerable transit zone for merciless sodium. Nephrol Dial Transplant 2013; 29:240-6. [PMID: 24335504 DOI: 10.1093/ndt/gft461] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In humans, when plasma sodium concentration rises slightly beyond 140 mM, vascular endothelium sharply stiffens and nitric oxide release declines. In search of a vascular sodium sensor, the endothelial glycocalyx was identified as being a negatively charged biopolymer capable of selectively buffering sodium ions. Sodium excess damages the glycocalyx and renders vascular endothelium increasingly permeable for sodium. In the long term, sodium accumulates in the interstitium and gradually damages the organism. It was discovered that circulating red blood cells (RBC) 'report' surface properties of the vascular endothelium. To some extent, the RBC glycocalyx mirrors the endothelial glycocalyx. A poor (charge-deprived) endothelial glycocalyx causes a poor RBC glycocalyx and vice versa. This observation led to the assumption that the current state of an individual's vascular endothelium in terms of electrical surface charges and sodium-buffering capabilities could be read simply from a blood sample. Recently, a so-called salt blood test was introduced that quantifies the RBC sodium buffer capacity and thus characterizes the endothelial function. The arguments are outlined in this article spanning a bridge from cellular nano-mechanics to clinical application.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II, Medical Faculty, University of Münster, Münster 48149, Germany
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Kusche-Vihrog K, Jeggle P, Oberleithner H. The role of ENaC in vascular endothelium. Pflugers Arch 2013; 466:851-9. [PMID: 24046153 DOI: 10.1007/s00424-013-1356-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/09/2013] [Accepted: 09/09/2013] [Indexed: 12/31/2022]
Abstract
Once upon a time, the expression of the epithelial sodium channel (ENaC) was mainly assigned to the kidneys, colon and sweat glands where it was considered to be the main determinant of sodium homeostasis. Recent, though indirect, evidence for the possible existence of ENaC in a non-epithelial tissue was derived from the observation that the vascular endothelium is a target for aldosterone. Inhibitory actions of the intracellular aldosterone receptors by spironolactone and, more directly, by ENaC blockers such as amiloride supported this view. Shortly after, direct data on the expression of ENaC in vascular endothelium could be demonstrated. There, endothelial ENaC (EnNaC) could be defined as a major regulator of cellular mechanics which is a critical parameter in differentiating between vascular function and dysfunction. Foremost, the mechanical stiffness of the endothelial cell cortex, a layer 50-200 nm beneath the plasma membrane, has been shown to play a crucial role as it controls the production of the endothelium-derived vasodilator nitric oxide (NO) which directly affects the tone of the vascular smooth muscle cells. In contrast to soft endothelial cells, stiff endothelial cells release reduced amounts of NO, the hallmark of endothelial dysfunction. Thus, the combination of endothelial stiffness and myogenic tone might increase the peripheral vascular resistance. An elevation of arterial blood pressure is supposed to be the consequence of such functional changes. In this review, EnNaC is discussed as an aldosterone-regulated plasma membrane protein of the vascular endothelium that could significantly contribute to maintaining of an appropriate arterial blood pressure but, if overexpressed, could participate in the pathogenesis of arterial hypertension.
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Affiliation(s)
- Kristina Kusche-Vihrog
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany,
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Abstract
Vascular endothelium plays a key role in blood pressure regulation. Recently, it has been shown that a 5% increase of plasma sodium concentration (sodium excess) stiffens endothelial cells by about 25%, leading to cellular dysfunction. Surface measurements demonstrated that the endothelial glycocalyx (eGC), an anionic biopolymer, deteriorates when sodium is elevated. In view of these results, a two-barrier model for sodium exiting the circulation across the endothelium is suggested. The first sodium barrier is the eGC which selectively buffers sodium ions with its negatively charged proteoglycans. The second sodium barrier is the endothelial plasma membrane which contains sodium channels. Sodium excess, in the presence of aldosterone, leads to eGC break-down and, in parallel, to an up-regulation of plasma membrane sodium channels. The following hypothesis is postulated: Sodium excess increases vascular sodium permeability. Under such conditions (e.g. high-sodium diet), day-by-day ingested sodium, instead of being readily buffered by the eGC and then rapidly excreted by the kidneys, is distributed in the whole body before being finally excreted. Gradually, the sodium overload damages the organism.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II, University of Münster, Münster, Germany.
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14
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Oberleithner H, Peters W, Kusche-Vihrog K, Korte S, Schillers H, Kliche K, Oberleithner K. Salt overload damages the glycocalyx sodium barrier of vascular endothelium. Pflugers Arch 2011; 462:519-28. [PMID: 21796337 PMCID: PMC3170475 DOI: 10.1007/s00424-011-0999-1] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2011] [Accepted: 07/16/2011] [Indexed: 01/05/2023]
Abstract
Sodium overload stiffens vascular endothelial cells in vitro and promotes arterial hypertension in vivo. The hypothesis was tested that the endothelial glycocalyx (eGC), a mesh of anionic biopolymers covering the surface of the endothelium, participates in the stiffening process. By using a mechanical nanosensor, mounted on an atomic force microscope, height (∼400 nm) and stiffness (∼0.25 pN/nm) of the eGC on the luminal endothelial surface of split-open human umbilical arteries were quantified. In presence of aldosterone, the increase of extracellular sodium concentration from 135 to 150 mM over 5 days (sodium overload) led the eGC shrink by ∼50% and stiffening by ∼130%. Quantitative eGC analyses reveal that sodium overload caused a reduction of heparan sulphate residues by 68% which lead to destabilization and collapse of the eGC. Sodium overload transformed the endothelial cells from a sodium release into a sodium-absorbing state. Spironolactone, a specific aldosterone antagonist, prevented these changes. We conclude that the endothelial glycocalyx serves as an effective buffer barrier for sodium. Damaged eGC facilitates sodium entry into the endothelial cells. This could explain endothelial dysfunction and arterial hypertension observed in sodium abuse.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany.
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15
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Büssemaker E, Hillebrand U, Hausberg M, Pavenstädt H, Oberleithner H. Pathogenesis of Hypertension: Interactions Among Sodium, Potassium, and Aldosterone. Am J Kidney Dis 2010; 55:1111-20. [DOI: 10.1053/j.ajkd.2009.12.022] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 12/03/2009] [Indexed: 01/11/2023]
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16
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Fels J, Oberleithner H, Kusche-Vihrog K. Ménage à trois: aldosterone, sodium and nitric oxide in vascular endothelium. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1193-202. [PMID: 20302930 DOI: 10.1016/j.bbadis.2010.03.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 12/16/2022]
Abstract
Aldosterone, a mineralocorticoid hormone mainly synthesized in the adrenal cortex, has been recognized to be a regulator of cell mechanics. Recent data from a number of laboratories implicate that, besides kidney, the cardiovascular system is an important target for aldosterone. In the endothelium, it promotes the expression of epithelial sodium channels (ENaC) and modifies the morphology of cells in terms of mechanical stiffness, surface area and volume. Additionally, it renders the cells highly sensitive to small changes in extracellular sodium and potassium. In this context, the time course of aldosterone action is pivotal. In the fast (seconds to minutes), non-genomic signalling pathway vascular endothelial cells respond to aldosterone with transient swelling, softening and insertion of ENaC in the apical plasma membrane. In parallel, nitric oxide (NO) is released from the cells. In the long-term (hours), aldosterone has opposite effects: The mechanical stiffness increases, the cells shrink and NO production decreases. This leads to the conclusion that both the physiology and pathophysiology of aldosterone action in the vascular endothelium are closely related. Aldosterone, at concentrations in the physiological range and over limited time periods can stabilize blood pressure and regulate tissue perfusion while chronically high concentrations of this hormone over extended time periods impair sodium homeostasis promoting endothelial dysfunction and the development of tissue fibrosis.
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Affiliation(s)
- Johannes Fels
- Institute of Physiology II, University of Münster, Germany
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17
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Sakly N, Mirshahi P, Ducros E, Soria J, Ghedira I, Mirshahi M. Angiogenic activity in sera of patients with systemic lupus erythematosus. Lupus 2009; 18:705-12. [DOI: 10.1177/0961203309103087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Angiogenesis plays a critical role in the pathogenesis of several connective tissue diseases. There is, however, relatively little information available on the role of angiogenesis in systemic lupus erythematosus (SLE). The aim of this study was to investigate the angiogenic activity in sera of patients with SLE and to determine the association between angiogenic activity and clinical complications. Sera from 66 Tunisian females with SLE and from 32 healthy blood donors were studied for their angiogenic activity using the in-vitro tube formation test on Matrigel. Samples were divided into five groups according to their angiogenic activity, which was scored from 0 (no angiogenesis) to 4 (high angiogenic activity). Samples from each group were then tested randomly to assess serum concentration of vascular endothelial growth factor (VEGF). No correlation was found between angiogenic activity scores and serum VEGF levels. Considering angiogenesis assessment in-vitro, sera of patients with SLE showed a much higher angiogenic activity than healthy controls since a high angiogenic score (score 4) is present in 43.9% of patients and in 6.3% of controls ( P < 0.0002). This high angiogenic activity is not correlated with disease activity; however, SLE patients with anti-dsDNA antibodies and those with nephritis showed higher angiogenic activity compared with patients without these complications since score 4 is found in 50.9% and 67.9% versus 9.1% ( P = 0.017) and 26.3% ( P < 0.001), respectively. In conclusion, our study showed that high serum angiogenic activity in SLE was not correlated with the VEGF levels. We suggest the use of the ‘in-vitro’ tube formation test as a better tool to study the angiogenic potential of sera. We found that in patients with SLE, serum angiogenic activity is increased compared with healthy controls. This high angiogenic activity is associated with renal complications and with the presence of anti-dsDNA antibodies. These findings suggest an involvement of angiogenesis disturbance in the pathogenesis of SLE.
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Affiliation(s)
- N Sakly
- Faculty of Pharmacy, Research Unit 03/UR/07-2, Monastir 5000, Tunisia; Faculty of Medicine, UMRS 872, CRC, Paris VI 15 rue de l’Ecole de Médecine, 75006 Paris, France
| | - P Mirshahi
- Faculty of Medicine, UMRS 872, CRC, Paris VI 15 rue de l’Ecole de Médecine, 75006 Paris, France
| | - E Ducros
- Faculty of Medicine, UMRS 872, CRC, Paris VI 15 rue de l’Ecole de Médecine, 75006 Paris, France
| | - J Soria
- Faculty of Medicine, UMRS 872, CRC, Paris VI 15 rue de l’Ecole de Médecine, 75006 Paris, France
| | - I Ghedira
- Faculty of Pharmacy, Research Unit 03/UR/07-2, Monastir 5000, Tunisia; Laboratory of Immunology, Farhat Hached Hospital, Sousse 4000, Tunisia
| | - M Mirshahi
- Faculty of Medicine, UMRS 872, CRC, Paris VI 15 rue de l’Ecole de Médecine, 75006 Paris, France
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18
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19
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Ducros E, Berthaut A, Mirshahi SS, Faussat AM, Soria J, Agarwal MK, Mirshahi M. Aldosterone modifies hemostasis via upregulation of the protein-C receptor in human vascular endothelium. Biochem Biophys Res Commun 2008; 373:192-6. [PMID: 18555797 DOI: 10.1016/j.bbrc.2008.05.185] [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] [Received: 05/14/2008] [Accepted: 05/30/2008] [Indexed: 01/05/2023]
Abstract
In human bone marrow endothelial cell (HBMEC) exposed for 8 h to aldosterone, the microarray screening revealed an upregulation of the mRNAs for six genes and downregulation of mRNAs for four genes, all implicated in hemostasis. In HBMEC, immunocytochemistry revealed the presence of the membrane-bound endothelial protein C receptor (EPCR) whereas the mineralocorticoid receptor (MCR) was present as a nucleo-cytoplasmic. In HBMEC treated with aldosterone the induction of EPCR protein was evident by both FACS analysis and dot blot procedure. When aldosterone-treated HBMEC were incubated with the activated protein C (APC), the partial thromboplastin clotting time (aPTT) increased 2.5-fold over control, from 10 to 25 s. The MCR antagonists aldactone and eplerenone reduced the basal coagulation time in untreated cells to 33.5% and 42% of the control, respectively. These data add an entirely new dimension to delineating the receptor-mediated action of mineralocorticoid hormones.
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MESH Headings
- Aldosterone/pharmacology
- Aldosterone/physiology
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Blood Coagulation/drug effects
- Blood Coagulation/genetics
- Cell Membrane/metabolism
- Cells, Cultured
- Cytoplasm/metabolism
- Endothelial Protein C Receptor
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Gene Expression/drug effects
- Gene Expression Profiling
- Gene Expression Regulation
- Hemostasis/drug effects
- Hemostasis/genetics
- Humans
- Partial Thromboplastin Time
- RNA, Messenger/metabolism
- Receptors, Cell Surface/agonists
- Receptors, Cell Surface/biosynthesis
- Receptors, Cell Surface/genetics
- Receptors, Mineralocorticoid/genetics
- Receptors, Mineralocorticoid/metabolism
- Up-Regulation
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Affiliation(s)
- Elodie Ducros
- UMRS 872, Centre de Recherche des Cordeliers, Faculté de Médecine Paris VI, 15 rue de l'Ecole de Médecine, 75006 Paris, France
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20
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Di Fabio F, Alvarado C, Majdan A, Gologan A, Voda L, Mitmaker E, Beitel LK, Gordon PH, Trifiro M. Underexpression of mineralocorticoid receptor in colorectal carcinomas and association with VEGFR-2 overexpression. J Gastrointest Surg 2007; 11:1521-8. [PMID: 17703341 DOI: 10.1007/s11605-007-0234-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 06/30/2007] [Indexed: 01/31/2023]
Abstract
BACKGROUND The human mineralocorticoid receptor (MR) is a steroid receptor widely expressed in colorectal mucosa. A significant role for the MR in the reduction of vascular endothelial growth factor receptor-2 (VEGFR-2) mRNA levels has been demonstrated in vitro. To evaluate a potential contribution of MR to colorectal carcinoma progression, we analyzed the expression of MR in relation to VEGFR-2. METHODS Fresh human colorectal cancer tissue and adjacent normal mucosa were harvested from 48 consecutive patients. MR and VEGFR-2 mRNA expression levels were determined by real-time reverse transcriptase-polymerase chain reaction and correlated with clinicopathological parameters. RESULTS A decline of MR expression was observed in all carcinomas compared to normal mucosa. Expression of MR was a median of 11-fold lower in carcinoma compared to the normal mucosa, irrespective of the location, size, stage, and differentiation. MR was a median of 20-fold underexpressed in carcinomas with VEGFR-2 overexpression vs only 9-fold in carcinomas with VEGFR-2 underexpression (p = 0.035, Mann-Whitney test). CONCLUSIONS These findings support the hypothesis that reduction of MR expression may be one of the early events involved in colorectal carcinoma progression. The inverse association between MR and VEGFR-2 expression in carcinoma suggests a potential tumor-suppressive function for MR.
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Affiliation(s)
- Francesco Di Fabio
- Department of Colon and Rectal Surgery, Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, Canada.
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21
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Oberleithner H, Riethmüller C, Schillers H, MacGregor GA, de Wardener HE, Hausberg M. Plasma sodium stiffens vascular endothelium and reduces nitric oxide release. Proc Natl Acad Sci U S A 2007; 104:16281-6. [PMID: 17911245 PMCID: PMC1999397 DOI: 10.1073/pnas.0707791104] [Citation(s) in RCA: 338] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Dietary salt plays a major role in the regulation of blood pressure, and the mineralocorticoid hormone aldosterone controls salt homeostasis and extracellular volume. Recent observations suggest that a small increase in plasma sodium concentration may contribute to the pressor response of dietary salt. Because endothelial cells are (i) sensitive to aldosterone, (ii) in physical contact with plasma sodium, and (iii) crucial regulators of vascular tone, we tested whether acute changes in plasma sodium concentration, within the physiological range, can alter the physical properties of endothelial cells. The tip of an atomic force microscope was used as a nanosensor to measure stiffness of living endothelial cells incubated for 3 days in a culture medium containing aldosterone at a physiological concentration (0.45 nM). Endothelial cell stiffness was unaffected by acute changes in sodium concentration <135 mM but rose steeply between 135 and 145 mM. The increase in stiffness occurred within minutes. Lack of aldosterone in the culture medium or treatment with the epithelial sodium channel inhibitor amiloride prevented this response. Nitric oxide formation was found down-regulated in cells cultured in aldosterone-containing high sodium medium. The results suggest that changes in plasma sodium concentration per se may affect endothelial function and thus control vascular tone.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II and Department of Internal Medicine D, University of Münster, 48149 Münster, Germany.
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22
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Kusche-Vihrog K, Sobczak K, Bangel N, Wilhelmi M, Nechyporuk-Zloy V, Schwab A, Schillers H, Oberleithner H. Aldosterone and amiloride alter ENaC abundance in vascular endothelium. Pflugers Arch 2007; 455:849-57. [PMID: 17891415 DOI: 10.1007/s00424-007-0341-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 08/29/2007] [Accepted: 08/30/2007] [Indexed: 10/22/2022]
Abstract
The amiloride-sensitive epithelial sodium channel (ENaC) is usually found in the apical membrane of epithelial cells but has also recently been described in vascular endothelium. Because little is known about the regulation and cell surface density of ENaC, we studied the influence of aldosterone, spironolactone, and amiloride on its abundance in the plasma membrane of human endothelial cells. Three different methods were applied, single ENaC molecule detection in the plasma membrane, quantification by Western blotting, and cell surface imaging using atomic force microscopy. We found that aldosterone increases the surface expression of ENaC molecules by 36% and the total cellular amount by 91%. The aldosterone receptor antagonist spironolactone prevents these effects completely. Acute application of amiloride to aldosterone-pretreated cells led to a decline of intracellular ENaC by 84%. We conclude that, in vascular endothelium, aldosterone induces ENaC expression and insertion into the plasma membrane. Upon functional blocking with amiloride, the channel disappears from the cell surface and from intracellular pools, indicating either rapid degradation and/or membrane pinch-off. This opens new perspectives in the regulation of ENaC expressed in the vascular endothelium.
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Affiliation(s)
- Kristina Kusche-Vihrog
- Institute of Animal Physiology, University of Muenster, Hindenburgplatz 55, 48143 Muenster, Germany.
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23
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Oberleithner H. Is the vascular endothelium under the control of aldosterone? Facts and hypothesis. Pflugers Arch 2007; 454:187-93. [PMID: 17285301 DOI: 10.1007/s00424-007-0205-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Accepted: 12/28/2006] [Indexed: 11/28/2022]
Abstract
Fluid and electrolyte balance in the human organism is controlled by aldosterone, a mineralocorticoid hormone of the suprarenal glands. The major target cells are localized in the kidney where the hormone controls transepithelial salt transport. Over the past few years, evidence has been accumulated that cells of the cardiovascular system are also targeted by the hormone. As an example, endothelial cells resemble similar mechanisms triggered by aldosterone as shown for the kidney. Although the pathological alterations induced by aldosterone excess are obvious, the physiological changes are largely unknown. On the basis of recent experiments, using atomic force microscopy as an imaging tool and a mechanical sensor, I present a hypothesis on the physiological role of aldosterone in endothelial function and its potential implications in the control of blood pressure.
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Affiliation(s)
- Hans Oberleithner
- Institut für Physiologie II, University of Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany.
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24
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Miternique-Grosse A, Griffon C, Siegel L, Neuville A, Weltin D, Stephan D. Antiangiogenic effects of spironolactone and other potassium-sparing diuretics in human umbilical vein endothelial cells and in fibrin gel chambers implanted in rats. J Hypertens 2006; 24:2207-13. [PMID: 17053542 DOI: 10.1097/01.hjh.0000249698.26983.4e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Potassium-sparing diuretics have different effects on angiogenesis that may mediate some abilities to treat cardiovascular diseases. The aim of the current study was to compare the effects of spironolactone and an active metabolite, canrenone, or a derivative, eplerenone, and amiloride, a diuretic without affecting mineralocorticoid activity, on the proliferation of human umbilical vein endothelial cells (HUVEC) and on angiogenesis in fibrin gel chambers implanted in rats. MATERIALS AND METHODS We measured the effects of spironolactone, canrenone, eplerenone, and amiloride on the proliferation of HUVEC in the presence or absence of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). We also examined the effects of these compounds on migration and capillary tube formation by HUVEC. Finally, the effects of the compounds on neovessel formation in vivo were investigated by implanting Wistar rats for 14 days with perforated Plexiglas chambers containing rat fibrin. RESULTS Spironolactone and amiloride inhibited the proliferation of HUVEC, but canrenone and eplerenone had no effect. The inhibitory effect of spironolactone was not prevented by VEGF or bFGF. Aldosterone had no effect on spironolactone-induced inhibition of HUVEC proliferation. Spironolactone induced a dose-dependent reduction of both cell chemotaxis and capillary tube formation. In fibrin gel chambers, spironolactone and amiloride significantly reduced the numbers of both peripheral and central neovessels. Canrenone and eplerenone, in contrast, had no antiangiogenic effect. CONCLUSION Spironolactone and amiloride significantly inhibited angiogenesis in vitro and in the fibrin gel chamber in vivo. Spironolactone antiangiogenic effects are unrelated to antimineralocorticoid activity.
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Affiliation(s)
- Anne Miternique-Grosse
- Laboratoire de Recherche sur l'Angiogenèse, Université Louis Pasteur, Faculté de Médecine, Strasbourg F-67085, France
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25
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Oberleithner H, Riethmüller C, Ludwig T, Shahin V, Stock C, Schwab A, Hausberg M, Kusche K, Schillers H. Differential action of steroid hormones on human endothelium. J Cell Sci 2006; 119:1926-32. [PMID: 16636077 DOI: 10.1242/jcs.02886] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The action of glucocorticoids on vascular permeability is well established. However, little is known about the action of mineralocorticoids on the structure and function of blood vessels. As endothelial cells are targets for both glucocorticoids and mineralocorticoids, we exposed human umbilical vein endothelial cells to both types of steroids. Aldosterone (mineralocorticoid) and dexamethasone (glucocorticoid) were applied for 3 days in culture before measurements of transendothelial ion and macromolecule permeability, apical cell surface and cell stiffness were taken. Transendothelial ion permeability was measured with electrical cell impedance sensing, macromolecule permeability with fluorescence-labeled dextran and apical cell membrane surface by three-dimensional AFM imaging. Cell stiffness was measured using the AFM scanning tip as a mechanical nanosensor. We found that aldosterone increased both apical cell surface and apical cell stiffness significantly, while transendothelial permeability remained unaffected. By contrast, dexamethasone significantly decreased ion and macromolecule permeability, while apical cell surface and cell stiffness did not change. Specific receptor antagonists for dexamethasone (RU486) and aldosterone (spironolactone) prevented the observed responses. We conclude that glucocorticoids strengthen cell-to-cell contacts (`peripheral action'), whereas mineralocorticoids enlarge and stiffen cells (`central action'). This could explain the dexamethasone-mediated retention of fluid in the vascular system, and endothelial dysfunction in states of hyperaldosteronism.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II, University Münster, 48149 Münster, Germany.
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26
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Quiney C, Billard C, Mirshahi P, Fourneron JD, Kolb JP. Hyperforin inhibits MMP-9 secretion by B-CLL cells and microtubule formation by endothelial cells. Leukemia 2006; 20:583-9. [PMID: 16467866 DOI: 10.1038/sj.leu.2404134] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We previously reported that hyperforin (HF), a natural phloroglucinol purified from Saint John's wort, can induce the apoptosis of leukemic cells from patients with B-cell lymphocytic leukemia (B-CLL) ex vivo. We show here that treatment of cultured B-CLL patients' cells with HF results in a marked inhibition of their capacity to secrete matrix metalloproteinase-9, an essential component in neo-angiogenesis through degradation of the extracellular matrix process. The phloroglucinol acts by decreasing the production of the latent 92 kDa pro-enzyme. The inhibitory effect of HF is associated with a decrease in VEGF release by the leukemic cells. Moreover, HF is found to prevent the formation of microtubules by human bone marrow endothelial cells cultured on Matrigel, evidencing its capacity to inhibit vessel formation. Our results show the antiangiogenesis activity of HF and strengthen its potential interest in the therapy of B-CLL.
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Affiliation(s)
- C Quiney
- UMRS 736 INSERM and Université Pierre et Marie Curie-Paris 6, Centre de Recherches Biomédicales des Cordeliers, Paris, France
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