Incorporation of Some Eicosaenoic Acids into Endothelial Cells – Effect on Platelet Inhibitory Activity and Prostacyclin Production

1985 ◽  
Vol 53 (02) ◽  
pp. 264-267 ◽  
Author(s):  
Béatrice Sicard ◽  
Michel Lagarde
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Beneficial Effect ◽  
Primary Cultures ◽  
Eicosatrienoic Acid ◽  
Dihomogammalinolenic Acid ◽  
Prostacyclin Production ◽  
Prostacyclin Synthesis ◽  
Platelet Functions

SummaryPrimary cultures of endothelial cells from human umbilical veins were grown until confluency. Then, dihomogammalinolenic acid (DHLA or 20:3n-6) and eicosapentaenoic acid (EPA or 20:5n-3), precursors of monoenoic and trienoic prostanoids, respectively, as well as 5,8,11-eicosatrienoic acid (20:3n-9), and isomer of DHLA, were incorporated into endothelial lipids. DHLA-rich endothelial cells had a decreased capacity of prostacyclin production. By contrast EPA- or 20:3n-9-rich endothelial cells were comparable to controls in this respect. DHLA and EPA were efficiently acylated into cell phospholipids and triglycerides at the opposite of 20:3n-9. It is suggested that both DHLA and EPA could alter the liberation of endogenous arachidonic acid for prostacyclin synthesis but this might be counterbalanced in EPA-rich endothelial cells by PGI3 production. We conclude that DHLA enrichment of endothelial cell lipids may impair the possible beneficial effect of the acid upon platelet functions whereas that of EPA would not be modified.

The Effect of Polyunsaturated Fatty Acids on Endothelial Cells and Their Production of Prostacyclin, Thromboxane and Platelet Inhibitory Activity

1983 ◽  
Vol 50 (04) ◽  
pp. 762-767 ◽  
Author(s):  
Jan H Brox ◽  
Arne Nordøy
Keyword(s):  
Fatty Acids ◽  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Polyunsaturated Fatty Acids ◽  
Linolenic Acid ◽  
Inhibitory Activity ◽  
Primary Cultures ◽  
Cell Monolayers ◽  
Docosahexaenoic Acids

SummaryPrimary cultures of human endothelial cell monolayers were incubated with albumin-bound fatty acids of the ω-3 and ω-6 families for a maximum of 24 hrs, to investigate the production of 6-keto-PGF1α, TXB2 and platelet inhibitory activity (PIA). Arachidonic acid was a potent stimulator of all parameters. The release of 6-keto-PGF1α was significantly reduced by equimolar concentrations of linoleic, dihomogamma linolenic and eicosapentaenoic acids, but not by linolenic acid. PIA was not similarity affected.Dihomogamma linolenic add was also a weak stimulator of 6- keto-PGF1α and PIA, but reduced the content of both in the cells after 24 hrs. Eicosapentaenoic and docosahexaenoic acids both depressed 6-keto-PGF1α production but PIA was maintained after 24 hrs. Indomethacin always blocked 6-keto-PGF1α and PIA production. None of the effects correlated to release of 51CR from prelabelled cells.

Effect of Tranylcypromine on Platelet Aggregation Induced by Thrombin, ADP, Adrenaline, Collagen and Arachidonic ACID

1979 ◽  
Author(s):  
C. Busch ◽  
C. Ljungman ◽  
L. Birgersson
Keyword(s):  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Platelet Aggregation ◽  
Thromboxane A2 ◽  
Inhibitory Effect ◽  
Selective Inhibitor ◽  
The Other ◽  
Common Pathway ◽  
Prostacyclin Synthesis ◽  
Platelet Functions

The monoaminooxidase inhibitor tranylcypromine has been suggested to be a selective inhibitor of prostacyclin synthetase with no inhibitory effect on thromboxane A2 formation in platelets. The substance would then be a suitable tool for discrimination between prostacyclin synthesis and release on one hand and other possible thrombocytophobic properties of the endothelial cell particularly its surface on the other. This study, however, shows that tranylcypromine interferes with platelet aggregation induced by thrombin, ADP, adrenaline and collagen whereas that of arachidonic acid is not affected. The results indicate an inhibition at an earlier common pathway of platelet aggregation than the metabolism of arachidonic acid. It is also suggested that the search for a selective inhibitor of prostacyclin synthesis which does not interfere with platelet functions should continue.

scholarly journals Selective internalization of arachidonic acid by endothelial cells

1987 ◽  
Vol 245 (1) ◽  
pp. 151-157 ◽  
Author(s):  
E R Hall ◽  
C E Manner ◽  
J Carinhas ◽  
R Snopko ◽  
M Rafelson
Keyword(s):  
Fatty Acids ◽  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Polyunsaturated Fatty Acids ◽  
Cell Types ◽  
Time Dependent ◽  
Asymmetric Distribution ◽  
Membrane Phospholipids ◽  
Bovine Endothelial Cell

The asymmetric distribution of phospholipids in bovine endothelial-cell membranes was probed with 2,4,6-trinitrobenzenesulphonate and purified phospholipase A2. The data suggest that phosphotidylethanolamine is primarily located in the inner lipid bilayer, as reported for other cell types. Stearic acid is taken up by the endothelial cells and is randomly distributed among the membrane phospholipids. In contrast, the polyunsaturated fatty acids (arachidonic, eicosatrienoic and eicosapentaenoic acids) have initial incorporation into the phosphatidylcholine fraction. These fatty acids then undergo a time-dependent transfer from phosphatidylcholine to phosphatidylethanolamine. Thus we propose that endothelial cells possess a mechanism for the selective internalization of polyunsaturated fatty acids.

Plasticity of endothelial cells: rapid dedifferentiation of freshly isolated high endothelial venule endothelial cells outside the lymphoid tissue microenvironment

Blood ◽  
2004 ◽  
Vol 103 (11) ◽  
pp. 4164-4172 ◽  
Author(s):  
Delphine-Armelle Lacorre ◽  
Espen S. Baekkevold ◽  
Ignacio Garrido ◽  
Per Brandtzaeg ◽  
Guttorm Haraldsen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Lymphoid Tissue ◽  
Ex Vivo ◽  
Primary Cultures ◽  
High Endothelial Venule ◽  
Tissue Specific ◽  
Tissue Microenvironment ◽  
Cell Phenotypes

Abstract Endothelial cells display remarkable heterogeneity in different organs and vascular beds. Although many studies suggest that tissues “speak” to endothelial cells, endothelial cell diversity remains poorly characterized at the molecular level. Here, we describe a novel strategy to characterize tissue-specific endothelial cell phenotypes and to identify endothelial cell genes that are under the control of the local microenvironment. By comparing post-capillary high endothelial venule endothelial cells (HEVECs), freshly isolated from human tonsils without any cell culture step, with HEVECs cultured for 2 days, we found that HEVECs rapidly lost their specialized characteristics when isolated from the lymphoid tissue microenvironment. Striking changes occurred as early as after 48 hours, with complete loss of the postcapillary venule–specific Duffy antigen receptor for chemokines (DARCs) and the HEV-specific fucosyltransferase Fuc-TVII. DNA microarray analysis identified several other candidate HEV genes that were rapidly down-regulated ex vivo, including type XV collagen, which we characterized as a novel, abundant HEV transcript in situ. Together, our results demonstrate that blood vessel type–specific and tissue-specific characteristics of endothelial cells are under the control of their microenvironment. Therefore, even short-term primary cultures of human endothelial cells may not adequately mimic the differentiated endothelial cell phenotypes existing in vivo.

scholarly journals Perturbations in the fibrinolytic pathway abolish cyst formation but not capillary-like organization of cultured murine endothelial cells

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3206-3217 ◽  
Author(s):  
N Dubois-Stringfellow ◽  
A Jonczyk ◽  
VL Bautch
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Basement Membrane ◽  
Organizational Behavior ◽  
Cell Lines ◽  
Primary Cultures ◽  
Cyst Formation ◽  
Fibrin Gels

Abstract Fibrinolytic activity and its relation to morphogenesis was investigated in several transformed murine endothelial cell lines and primary cultures of endothelial cells. Two in vitro systems, fibrin gels and Matrigel (Collaborative Research, Bedford, MA), were used. Fibrin gels model a fibrin-rich extracellular matrix that frequently supports neovascularization in vivo, and Matrigel models the basement membrane surrounding quiescent endothelial cells in vivo. The transformed endothelial cell lines have higher levels of plasminogen activator (PA) mRNA than primary cultures of endothelial cells, and an increased PA-mediated proteolytic activity was correlated with formation of cysts in fibrin gels. Addition of neutralizing anti- urokinase antibodies, plasminogen depletion, or addition of a plasmin inhibitor prevented cyst formation. Addition of plasminogen restored the ability to form cysts in the plasminogen-depleted system. Normal endothelial cells organized into capillary-like structures in fibrin gels regardless of manipulations affecting the fibrinolytic pathway. In Matrigel, both transformed and primary cultures of endothelial cells rapidly formed a capillary-like network that was not affected by plasminogen depletion or addition of plasmin inhibitors. Thus, elements of the fibrinolytic pathway necessary for cyst formation are not critical in capillary-like structure formation on a reconstituted basement membrane. These results suggest that plasmin is essential for hemangioma formation but is not critical to the organizational behavior of normal endothelial cells.

Ibuprofen protects human endothelial cell prostaglandin H synthase from hydrogen peroxide

1996 ◽  
Vol 271 (6) ◽  
pp. C1879-C1886 ◽  
Author(s):  
D. A. Wessels ◽  
S. L. Hempel
Keyword(s):  
Hydrogen Peroxide ◽  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Arachidonic Acid Release ◽  
Human Endothelial Cells ◽  
Prostaglandin H Synthase ◽  
Cyclooxygenase Activity ◽  
Acid Release ◽  
Prostaglandin H

Human endothelial cells exposed to H2O2 demonstrate decreased prostacyclin (PGI2) synthesis due to decreased prostaglandin H synthase (PGH synthase) activity. We tested the hypothesis that PGH synthase activity could be protected from H2O2 by a reversible nonsteroidal anti-inflammatory drug. Experiments demonstrate that ibuprofen if present during H2O2 exposure, protects endothelial cell PGH synthase against the decrease in prostaglandin formation caused by H2O2. Additional studies demonstrated that decreasing arachidonic acid release from cell phospholipids during H2O2 exposure did not protect PGI2 synthesis following H2O2 exposure. In other experiments, ibuprofen did not chelate Fe2+ in a conformation that inhibited the reactivity of Fe2+. In addition, ibuprofen did not scavenge HO. However, we demonstrate that ibuprofen significantly protects purified PGH synthase cyclooxygenase activity from the effects of H2O2. The results confirm the hypothesis. These findings suggest that ibuprofen displaces oxidant species from the cyclooxygenase site of PGH synthase, thereby preventing oxidation of the functional groups important for PGH synthase activity.

Stimulation Of Prostacyclin Production In Aortic Endothelial Cells By A Non-Dialysable Serum Factor

1981 ◽  
Author(s):  
E R Hall ◽  
M Rafelson ◽  
K Wu
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Calf Serum ◽  
Dependent Manner ◽  
Freezing And Thawing ◽  
Concentration Dependent Manner ◽  
Aortic Endothelial Cells ◽  
Prostacyclin Production ◽  
Aortic Endothelial

The production of prostacyclin (PGI2) by vascular endothelial cells is thought to be of primary importance in maintaining normal hemostasis. We have investigated the production of prostacyclin in bovine arterial endothelial cells maintained in Dulbecco’s modified Eagle’s medium (DMEM) containing 30% fetal calf serum. Intact, confluent monolayers of endothelial cells (3x106 cells) in passages 2 through 6 were used. The growth medium was removed and the cells were washed in DMEM that did not contain serum. 3 mls of medium alone or containing normal plasma or serum was then added and incubated at 37°C for 15 min. Then, 1 mg of arachidonic acid was added and the cells incubated for an additional hour. The test medium was removed, centrifuged to remove any loose cells and stored at -70°C. To determine the production of PGI2 by the endothelial cells, the medium was assayed for 6-keto-PGF1α, the stable metabolite of PGI2, by radioimmunoassay. The synthesis of prostacyclin by bovine aortic endothelial cells was significantly increased in a concentration dependent manner by both normal platelet poor plasma and normal serum. This increase in prostacyclin production was inhibited by both aspirin and indomethacin, indicating an increase in synthesis rather than the release of PGI2. Furthermore, this increase could be demonstrated in the presence or absence of added arachidonic acid. The active component in plasma and serum was non-dialysable, eliminating the possibility of a small compound such as bradykinin or angiotensin II. This active factor was present after freezing and thawing the plasma and serum and was heat stable (60°C, 5 min). The presence of an endogenous prostacyclin stimulating factor may be significant in the in vivo regulation of prostacyclin production.

Endotoxin enhances arachidonic acid metabolism by cultured rabbit microvascular endothelial cells

1992 ◽  
Vol 263 (4) ◽  
pp. H1213-H1221 ◽  
Author(s):  
P. M. Renzi ◽  
J. T. Flynn
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Time Course ◽  
Lipid A ◽  
Primary Cultures ◽  
Microvascular Endothelial Cells ◽  
Prostaglandin Endoperoxide ◽  
Eicosanoid Production ◽  
Prostaglandin Endoperoxide Synthase ◽  
Microvascular Endothelial

This study demonstrates that bacterial lipopolysaccharide and lipid A exert a significant effect on eicosanoid formation by primary cultures of microvascular endothelial cells (MECs). Qualitative studies using [14C]-arachidonic acid demonstrated that prostaglandin E2 was the primary eicosanoid formed by MECs after 20 h of treatment with either vehicle or lipopolysaccharide. Significant, dose-dependent productions of PGE2 and prostacyclin, beginning at an endotoxin dose of 0.01 ng/ml, were quantified by radioimmunoassay in supernatants of cells treated for 20 h with lipopolysaccharide or lipid A. This eicosanoid production was inhibited by meclofenamate and cycloheximide and occurred without cellular injury. The time course and kinetics of eicosanoid production in response to endotoxin demonstrate a significant, time-related enhancement. Endotoxin-treated MECs responded to exogenous substrate with augmented PGE2 production, suggesting enhanced prostaglandin endoperoxide synthase activity. These results demonstrate a significant interaction of endotoxin with endothelial cells of microvascular origin that results in an enhanced potential for eicosanoid metabolism. This effect may be mediated in part through induction of prostaglandin endoperoxide synthase.

Prostacyclin: Production by Vascular Endothelium and Effects on Platelet Aggregation

1979 ◽  
Author(s):  
S. Moncada ◽  
S. Bunting
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Vascular Endothelium ◽  
Vascular Endothelial Cells ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
Vascular Endothelial ◽  
Prostacyclin Production

The inhibitory effect of vascular endothelial cells on platelet aggregation is due to their ability to release prostacyclin. The existence of an ADPase has been confirmed in endothelial cells but this enzymes does not seem to be related to the anti-aggregating properties of vascular endothelium. In vitro, the release of prostacyclin by humand and rabbit endothelial cells persists after several subcultures. The production of PGI2 can be demonstrated by its inhibition by aspirin-like drugs or 15-hydroperoxy arachidonic acid (a specific inhibitor of PGI2 synthesis). Moreover, the antiaggregating activity is antagonised by an antibody to 5,6 dihydro prostacyclin which cross reacts and neutralises prostacyclin.

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