scholarly journals Intracellular ascorbate tightens the endothelial permeability barrier through Epac1 and the tubulin cytoskeleton

2016 ◽  
Vol 311 (4) ◽  
pp. C652-C662 ◽  
Author(s):  
William H. Parker ◽  
Elizabeth Meredith Rhea ◽  
Zhi-Chao Qu ◽  
Morgan R. Hecker ◽  
James M. May
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Cyclic Amp ◽  
Umbilical Vein ◽  
Endothelial Permeability ◽  
Cell Contact ◽  
Permeability Barrier ◽  
Basal Cells ◽  
Microtubule Stabilization ◽  
Umbilical Vein Endothelial Cells

Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species.

Hypoxia-induced pulmonary endothelin-1 expression is unaltered by nitric oxide

2002 ◽  
Vol 92 (3) ◽  
pp. 1152-1158 ◽  
Author(s):  
Scott Earley ◽  
Leif D. Nelin ◽  
Louis G. Chicoine ◽  
Benjimen R. Walker
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Promoter Activity ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Exposure ◽  
Mrna Levels ◽  
Protective Effects ◽  
No Donor ◽  
Umbilical Vein Endothelial Cells

Nitric oxide (NO) attenuates hypoxia-induced endothelin (ET)-1 expression in cultured umbilical vein endothelial cells. We hypothesized that NO similarly attenuates hypoxia-induced increases in ET-1 expression in the lungs of intact animals and reasoned that potentially reduced ET-1 levels may contribute to the protective effects of NO against the development of pulmonary hypertension during chronic hypoxia. As expected, hypoxic exposure (24 h, 10% O2) increased rat lung ET-1 peptide and prepro-ET-1 mRNA levels. Contrary to our hypothesis, inhaled NO (iNO) did not attenuate hypoxia-induced increases in pulmonary ET-1 peptide or prepro-ET-1 mRNA levels. Because of this surprising finding, we also examined the effects of NO on hypoxia-induced increases in ET peptide levels in cultured cell experiments. Consistent with the results of iNO experiments, administration of the NO donor S-nitroso- N-acetyl-penicillamine to cultured bovine pulmonary endothelial cells did not attenuate increases in ET peptide levels resulting from hypoxic (24 h, 3% O2) exposure. In additional experiments, we examined the effects of NO on the activity of a cloned ET-1 promoter fragment containing a functional hypoxia inducible factor-1 binding site in reporter gene experiments. Whereas moderate hypoxia (24 h, 3% O2) had no effect on ET-1 promoter activity, activity was increased by severe hypoxic (24 h, 0.5% O2) exposure. ET-1 promoter activity after S-nitroso- N-acetyl-penicillamine administration during severe hypoxia was greater than that in normoxic controls, although activity was reduced compared with that in hypoxic controls. These findings suggest that hypoxia-induced pulmonary ET-1 expression is unaffected by NO.

scholarly journals Effect of aminaphtone on in vitro vascular permeability and capillary-like maintenance

2017 ◽  
Vol 33 (9) ◽  
pp. 592-599 ◽  
Author(s):  
Francesca Felice ◽  
Ester Belardinelli ◽  
Alessandro Frullini ◽  
Tatiana Santoni ◽  
Egidio Imbalzano ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Chronic Venous Insufficiency ◽  
Venous Insufficiency ◽  
Umbilical Vein ◽  
Three Dimensional ◽  
Endothelial Permeability ◽  
Human Umbilical Vein ◽  
Pre Treatment ◽  
Umbilical Vein Endothelial Cells

Objectives Aminaphtone, a naphtohydrochinone used in the treatment of capillary disorders, may affect oedema in chronic venous insufficiency. Aim of study is to investigate the effect of aminaphtone on vascular endothelial permeability in vitro and its effects on three-dimensional capillary-like structures formed by human umbilical vein endothelial cells. Method Human umbilical vein endothelial cells were treated with 50 ng/ml VEGF for 2 h and aminaphtone for 6 h. Permeability assay, VE-cadherin expression and Matrigel assay were performed. Results VEGF-induced permeability was significantly decreased by aminaphtone in a range concentration of 1–20 µg/ml. Aminaphtone restored VE-cadherin expression. Finally, 6 h pre-treatment with aminaphtone significantly preserved capillary-like structures formed by human umbilical vein endothelial cells on Matrigel up to 48 h compared to untreated cells. Conclusions Aminaphtone significantly protects endothelium permeability and stabilises endothelial cells organised in capillary-like structures, modulating VE-cadherin expression. These data might explain the clinical benefit of aminaphtone on chronic venous insufficiency.

scholarly journals Cilostazol Induces eNOS and TM Expression via Activation with Sirtuin 1/Krüppel-like Factor 2 Pathway in Endothelial Cells

2021 ◽  
Vol 22 (19) ◽  
pp. 10287
Author(s):  
Chih-Hsien Wu ◽  
Yi-Lin Chiu ◽  
Chung-Yueh Hsieh ◽  
Guo-Shiang Tsung ◽  
Lian-Shan Wu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Umbilical Vein ◽  
Sirtuin 1 ◽  
No Production ◽  
Beneficial Effects ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Cilostazol was suggested to be beneficial to retard in-stent atherosclerosis and prevent stent thrombosis. However, the mechanisms responsible for the beneficial effects of cilostazol are not fully understood. In this study, we attempted to verify the mechanism of the antithrombotic effect of cilostazol. Human umbilical vein endothelial cells (HUVECs) were cultured with various concentrations of cilostazol to verify its impact on endothelial cells. KLF2, silent information regulator transcript-1 (SIRT1), endothelial nitric oxide synthase (eNOS), and endothelial thrombomodulin (TM) expression levels were examined. We found cilostazol significantly activated KLF2 expression and KLF2-related endothelial function, including eNOS activation, Nitric oxide (NO) production, and TM secretion. The activation was regulated by SIRT1, which was also stimulated by cilostazol. These findings suggest that cilostazol may be capable of an antithrombotic and vasculoprotective effect in endothelial cells.

scholarly journals Effects of Propofol on Cyclic Strain-induced Endothelin-1 Expression in Human Umbilical Vein Endothelial Cells

2009 ◽  
Vol 110 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Tzu-Hurng Cheng ◽  
Jin-Jer Chen ◽  
Cheng-Hsien Chen ◽  
Kar-Lok Wong
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Protein Kinase ◽  
Umbilical Vein ◽  
Cyclic Strain ◽  
Nitric Oxide Production ◽  
Human Umbilical Vein ◽  
Oxide Production ◽  
Extracellular Signal ◽  
Umbilical Vein Endothelial Cells

Background Propofol is one of the most popular intravenous induction agents of general anesthesia. Experimental results revealed that propofol exerted hypotensive and antioxidative effects. However, the intracellular mechanism of propofol remains to be delineated. The aims of this study were to test the hypothesis that propofol may alter strain-induced endothelin-1 (ET-1) secretion and nitric oxide production, and to identify the putative underlying signaling pathways in human umbilical vein endothelial cells. Methods Cultured human umbilical vein endothelial cells were exposed to cyclic strain in the presence of propofol, and ET-1 expression was examined by Northern blotting and enzyme-linked immunosorbent assay kit. Activation of extracellular signal-regulated protein kinase, endothelial nitric oxide synthase, and protein kinase B were assessed by Western blot analysis. Results The authors show that propofol inhibits strain-induced ET-1 expression, strain-increased reactive oxygen species formation, and extracellular signal-regulated protein kinase phosphorylation. On the contrary, nitric oxide production, endothelial nitric oxide synthase activity, and protein kinase B phosphorylation were enhanced by propofol treatment. Furthermore, in the presence of PTIO, a nitric oxide scavenger, and KT5823, a specific inhibitor of cyclic guanosine monophosphate-dependent protein kinase, the inhibitory effect of propofol on strain-induced extracellular signal-regulated protein kinase phosphorylation and ET-1 release was reversed. Conclusions The authors demonstrate for the first time that propofol inhibits strain-induced ET-1 secretion and enhances strain-increased nitric oxide production in human umbilical vein endothelial cells. Thus, this study delivers important new insight into the molecular pathways that may contribute to the proposed hypotensive effects of propofol in the cardiovascular system.

Paradoxical overexpression and translocation of connexin43 in homocysteine-treated endothelial cells

2002 ◽  
Vol 282 (6) ◽  
pp. H2124-H2133 ◽  
Author(s):  
Hong Li ◽  
Sergey Brodsky ◽  
Sindu Kumari ◽  
Virginijus Valiunas ◽  
Peter Brink ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Fluorescent Protein ◽  
Lucifer Yellow ◽  
Umbilical Vein ◽  
Expression Screening ◽  
Fluorescent Markers ◽  
Junctional Communication ◽  
Green Fluorescent ◽  
Umbilical Vein Endothelial Cells

Hyperhomocysteinemia is an established cause of defective vasorelaxation. Gene expression screening of human umbilical vein endothelial cells (HUVEC) treated with homocysteine (Hcy) revealed that connexin43 (Cx43) was upregulated. Expression of Cx43 was increased more than twofold in Hcy-treated HUVEC. Gap junctional communication (Lucifer yellow and whole cell patch clamp) was not enhanced in Hcy-treated HUVEC. HUVEC expressing chimeric Cx43-green fluorescent protein exhibited it at cell-cell contacts in control but showed redistribution to the intracellular compartment(s) in Hcy-treated cells. Confocal microscopy of HUVEC stained with anti-Cx43, mitochondrial, and endoplasmic reticulum fluorescent markers showed the localization of Cx43 to the plasma membrane of control cells and its colocalization with the mitochondrial marker in Hcy-treated HUVEC. Studies of isolated mitochondria confirmed overexpression of Cx43 in the mitochondria of Hcy-treated HUVEC. Microdissected renal interlobar arteries, which normally exhibit endothelium-derived hyperpolarizing factor-induced vasorelaxation, showed reduced nitric oxide synthase- and cyclooxygenase-independent vasorelaxation to acetylcholine after pretreatment with Hcy. In summary, Hcy-induced upregulation of Cx43 transcript and protein expression are associated with unaltered intercellular communication, redistribution of Cx43 in HUVEC, and reduced nitric oxide- and prostanoid-independent vascular responses to acetylcholine in Hcy-treated arteries.

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