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.

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.

scholarly journals Dietary fat and the diabetic state alter insulin binding and the fatty acyl composition of the adipocyte plasma membrane

1988 ◽  
Vol 253 (2) ◽  
pp. 417-424 ◽  
Author(s):  
C J Field ◽  
E A Ryan ◽  
A B Thomson ◽  
M T Clandinin
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Insulin Binding ◽  
Fatty Acyl ◽  
Membrane Composition ◽  
Membrane Phospholipids ◽  
Diabetic State

Control and diabetic rats were fed on semi-purified high-fat diets providing a polyunsaturated/saturated fatty acid ratio (P/S) of 1.0 or 0.25, to examine the effect of diet on the fatty acid composition of major phospholipids of the adipocyte plasma membrane. Feeding the high-P/S diet (P/S = 1.0) compared with the low-P/S diet (P/S = 0.25) increased the content of polyunsaturated fatty acids in membrane phospholipids in both control and diabetic animals. The diabetic state decreased the content of polyunsaturated fatty acids, particularly arachidonic acid, in adipocyte membrane phospholipids. The decrease in arachidonic acid in membrane phospholipids of diabetic animals tended to be normalized to within the control values when high-P/S diets were given. For control animals, altered plasma-membrane composition was associated with change in insulin binding, suggesting that change in plasma-membrane composition may have physiological consequences for insulin-stimulated functions in the adipocyte.

scholarly journals Arsenic trioxide induces dose- and time-dependent apoptosis of endothelium and may exert an antileukemic effect via inhibition of angiogenesis

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1525-1530 ◽  
Author(s):  
Gail J. Roboz ◽  
Sergio Dias ◽  
George Lam ◽  
William J. Lane ◽  
Steven L. Soignet ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Arsenic Trioxide ◽  
Leukemic Cell ◽  
Cell Types ◽  
Time Dependent ◽  
Leukemic Cells ◽  
Sequence Of Events ◽  
Antileukemic Effect

Arsenic trioxide (As2O3) has recently been used successfully in the treatment of acute promyelocytic leukemia and has been shown to induce partial differentiation and apoptosis of leukemic cells in vitro. However, the mechanism by which As2O3 exerts its antileukemic effect remains uncertain. Emerging data suggest that the endothelium and angiogenesis play a seminal role in the proliferation of liquid tumors, such as leukemia. We have shown that activated endothelial cells release cytokines that may stimulate leukemic cell growth. Leukemic cells, in turn, can release endothelial growth factors, such as vascular endothelial growth factor (VEGF). On the basis of these observations, we hypothesized that As2O3 may interrupt a reciprocal loop between leukemic cells and the endothelium by direct action on both cell types. We have shown that treatment of proliferating layers of human umbilical vein endothelial cells (HUVECs) with a variety of concentrations of As2O3results in a reproducible dose- and time-dependent sequence of events marked by change to an activated morphology, up-regulation of endothelial cell adhesion markers, and apoptosis. Also, treatment with As2O3 caused inhibition of VEGF production in the leukemic cell line HEL. Finally, incubation of HUVECs with As2O3 prevented capillary tubule and branch formation in an in vitro endothelial cell–differentiation assay. In conclusion, we believe that As2O3 interrupts a reciprocal stimulatory loop between leukemic cells and endothelial cells by causing apoptosis of both cell types and by inhibiting leukemic cell VEGF production.

13-HYDROXY-9,11-OCTADECADIENOIC ACID (13-HOD) INCREASES PROSTACYCLIN PRODUCTION IN ENDOTHELIAL CELLS

1987 ◽  
Author(s):  
B N Y Setty ◽  
M Berger ◽  
M J Stuart
Keyword(s):  
Fatty Acids ◽  
Endothelial Cells ◽  
Time Course ◽  
Octadecadienoic Acid ◽  
Time Dependent ◽  
Membrane Phospholipids ◽  
Metabolic Products ◽  
Subsequent Conversion ◽  
Fetal Bovine ◽  
Prostacyclin Production

Recently, endothelial cells (ECs) have been shown to generate a potent vascular chemorepellant factor. This metabolite, 13-HOD is reported to be the major lipoxygenase product produced in microgram amounts in ECs (JBC 260:16056, 1985). We have studied the effect of 13-HOD on EC arachidonic acid (AA) metabolism, and report modulation of both AA release and conversion to prostacyclin. Using fetal bovine aortic ECs, 13-HOD stimulated prostacyclin production (RIA for 6KPGF1α ) by 40±13% (1SE), and 51±09% at 10 and 30μM (P<0.05; n=5). When the time-course of this effect was evaluated, 13-HOD (30μM) significantly enhanced the time-dependent release of 6KPGF1α by 31 to 51% between 5 and 120 min. (P<0.05 to 0.01; n=5). In [14C]AA labeled cells, this compound modulated both AA release and its subsequent conversion. In 5 paired experiments, 13-HOD (30μM) enhanced the release of AA from membrane phospholipids (9065±0553 cpm/well in controls vs 10738±1725 in 13-HOD treated cells; PC0.01). Analysis of cellular phospholipids revealed a significant decrease in [14C]phosphatidylethanolamine (62312±3963 cpm/well in controls vs 56959±4104 in 13-HOD treated cells; P<0.02). No significant changes were seen in the levels of phosphatidyl-choline, -serine, -inositol, or phosphatidic acid. Production of [14C]prostacyclin was stimulated by 56±16% (P<0.01 ), while total cyclooxygenase metabolites increased by 28±8% (P<0.01), suggesting effects on both cyclooxygenase and prostacyclin synthetase. 13-HOD, the major vascular product of linoleic acid enhances both AA release and metabolism, thus demonstrating an intimate hemostatic interaction between the metabolic products of these two polyunsaturated fatty acids in endothelial cells.

scholarly journals Arsenic trioxide induces dose- and time-dependent apoptosis of endothelium and may exert an antileukemic effect via inhibition of angiogenesis

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1525-1530 ◽  
Author(s):  
Gail J. Roboz ◽  
Sergio Dias ◽  
George Lam ◽  
William J. Lane ◽  
Steven L. Soignet ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Arsenic Trioxide ◽  
Leukemic Cell ◽  
Cell Types ◽  
Time Dependent ◽  
Leukemic Cells ◽  
Sequence Of Events ◽  
Antileukemic Effect

Abstract Arsenic trioxide (As2O3) has recently been used successfully in the treatment of acute promyelocytic leukemia and has been shown to induce partial differentiation and apoptosis of leukemic cells in vitro. However, the mechanism by which As2O3 exerts its antileukemic effect remains uncertain. Emerging data suggest that the endothelium and angiogenesis play a seminal role in the proliferation of liquid tumors, such as leukemia. We have shown that activated endothelial cells release cytokines that may stimulate leukemic cell growth. Leukemic cells, in turn, can release endothelial growth factors, such as vascular endothelial growth factor (VEGF). On the basis of these observations, we hypothesized that As2O3 may interrupt a reciprocal loop between leukemic cells and the endothelium by direct action on both cell types. We have shown that treatment of proliferating layers of human umbilical vein endothelial cells (HUVECs) with a variety of concentrations of As2O3results in a reproducible dose- and time-dependent sequence of events marked by change to an activated morphology, up-regulation of endothelial cell adhesion markers, and apoptosis. Also, treatment with As2O3 caused inhibition of VEGF production in the leukemic cell line HEL. Finally, incubation of HUVECs with As2O3 prevented capillary tubule and branch formation in an in vitro endothelial cell–differentiation assay. In conclusion, we believe that As2O3 interrupts a reciprocal stimulatory loop between leukemic cells and endothelial cells by causing apoptosis of both cell types and by inhibiting leukemic cell VEGF production.

Endothelium-dependent vasodilation by melittin: are lipoxygenase products involved?

1985 ◽  
Vol 249 (1) ◽  
pp. H14-H19 ◽  
Author(s):  
U. Forstermann ◽  
B. Neufang
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Polyunsaturated Fatty Acids ◽  
Rabbit Aorta ◽  
Membrane Phospholipids ◽  
Endothelium Derived Relaxing Factor ◽  
Potential Inhibitors ◽  
Endothelium Dependent Relaxation ◽  
Acid Compound

Vascular relaxation in response to acetylcholine and other vasodilator compounds has been shown to depend on intact endothelial cells. These dilator compounds obviously induce the formation of an unstable endothelium-derived relaxing factor or factors (EDRF) from the intima which relax the subjacent smooth muscle cells. The chemical identity of this factor (these factors) is still unclear. In the present study we demonstrate that endothelium-dependent relaxation of rabbit aorta was induced by melittin, a polypeptide toxin that activates phospholipase A2 to liberate polyunsaturated fatty acids (especially arachidonic acid) from membrane phospholipids. The relaxation induced by melittin had several properties similar to the acetylcholine relaxation. It was inhibited by potential inhibitors of phospholipase (mepacrine and p-bromophenacylbromide), by inhibitors of lipoxygenase (nordi-hydroguaiaretic acid, compound BW 755C, and 5,8,11,14-eicosatetraynoic acid) but not by the cyclooxygenase inhibitor indomethacin. An exogenous preparation of phospholipase C also induced endothelium-dependent relaxations. These findings support the hypothesis that oxidized metabolites of polyunsaturated fatty acids (e.g., arachidonic acid) may be involved directly (as mediators) or indirectly in the process of endothelium-dependent relaxation. On the other hand, exogenous arachidonic acid was a comparatively weak endothelium-dependent relaxant. However, this does not exclude an important role of endogenous arachidonic acid since the exogenous acid may not sufficiently reach its site of metabolism.

Inhibition of inwardly rectifying K+ channels by cGMP in pulmonary vascular endothelial cells

2002 ◽  
Vol 283 (2) ◽  
pp. L297-L304 ◽  
Author(s):  
Larissa A. Shimoda ◽  
Laura E. Welsh ◽  
David B. Pearse
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Cell Types ◽  
Protective Mechanism ◽  
Cell Integrity ◽  
Barrier Dysfunction ◽  
Whole Cell Patch Clamp ◽  
Inward Currents ◽  
Inwardly Rectifying

Endothelial barrier dysfunction is typically triggered by increased intracellular Ca2+concentration. Membrane-permeable analogs of guanosine 3′,5′-cyclic monophosphate (cGMP) prevent disruption of endothelial cell integrity. Because membrane potential ( E m), which influences the electrochemical gradient for Ca2+ influx, is regulated by K+ channels, we investigated the effect of 8-bromo-cGMP on E m and inwardly rectifying K+ (KIR) currents in bovine pulmonary artery and microvascular endothelial cells (BPAEC and BMVEC), using whole cell patch-clamp techniques. Both cell types exhibited inward currents at potentials negative to −50 mV that were abolished by application of 10 μM Ba2+, consistent with KIR current. Ba2+ also depolarized both cell types. 8-Bromo-cGMP (10−3 M) depolarized BPAEC and BMVEC and inhibited KIR current. Pretreatment with Rp-8-cPCT-cGMPS or KT-5823, protein kinase G (PKG) antagonists, did not prevent current inhibition by 8-bromo-cGMP. These data suggest that 8-bromo-cGMP induces depolarization in BPAEC and BMVEC due, in part, to PKG-independent inhibition of KIR current. The depolarization could be a protective mechanism that prevents endothelial cell barrier dysfunction by reducing the driving force for Ca2+ entry.

scholarly journals Adrenaline Stimulation of Phospholipid Metabolism in Adipocyte Ghosts

1987 ◽  
Vol 40 (4) ◽  
pp. 405
Author(s):  
David Mann ◽  
Audrey M Bersten
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Linoleic Acid ◽  
Adenylate Cyclase ◽  
Phospholipid Metabolism ◽  
Dependent Manner ◽  
Long Chain Fatty Acids ◽  
Membrane Phospholipids ◽  
Dose Dependent ◽  
Stimulation Of

The incorporation of long-chain fatty acids into phospholipids has been detected in adipocyte ghosts that were incubated with [1_14 C] stearic, [1_14 C] linoleic or [l_14C] arachidonic acid. Adrenaline and adenosine activated this incorporation within 15 s of exposure of the ghosts to the hormones and the response was dose dependent. Maximum incorporation of labelled linoleic acid occurred at 10-5 M adrenaline and 10-7 M adenosine. The a-agonist phenylephrine and the ~-agonist isoproterenol were also shown to stimulate the incorporation of fatty acid in a dose dependent manner. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were each labelled preferentially with linoleic or arachidonic acid. p-Bromophenacylbromide, quinacrine and centrophenoxine inhibited the adrenaline-stimulated incorporation of fatty acids into ghost membrane phospholipids, and p-bromophenacylbromide also reduced the activation of adenylate cyclase by adrenaline. NaF, an activator of adenylate cyclase, like adrenaline, stimulated the incorporation of linoleic acid into ghost membrane phospholipids.

scholarly journals HiPS-Endothelial Cells Acquire Cardiac Endothelial Phenotype in Co-culture With hiPS-Cardiomyocytes

2021 ◽  
Vol 9 ◽  
Author(s):  
Emmi Helle ◽  
Minna Ampuja ◽  
Alexandra Dainis ◽  
Laura Antola ◽  
Elina Temmes ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Animal Studies ◽  
Cardiac Development ◽  
Cell Types ◽  
Human Endothelial Cells ◽  
Bidirectional Communication ◽  
Induced Pluripotent ◽  
And Function ◽  
Cell Crosstalk

Cell-cell interactions are crucial for organ development and function. In the heart, endothelial cells engage in bidirectional communication with cardiomyocytes regulating cardiac development and growth. We aimed to elucidate the organotypic development of cardiac endothelial cells and cardiomyocyte and endothelial cell crosstalk using human induced pluripotent stem cells (hiPSC). Single-cell RNA sequencing was performed with hiPSC-derived cardiomyocytes (hiPS-CMs) and endothelial cells (hiPS-ECs) in mono- and co-culture. The presence of hiPS-CMs led to increased expression of transcripts related to vascular development and maturation, cardiac development, as well as cardiac endothelial cell and endocardium-specific genes in hiPS-ECs. Interestingly, co-culture induced the expression of cardiomyocyte myofibrillar genes and MYL7 and MYL4 protein expression was detected in hiPS-ECs. Major regulators of BMP- and Notch-signaling pathways were induced in both cell types in co-culture. These results reflect the findings from animal studies and extend them to human endothelial cells, demonstrating the importance of EC-CM interactions during development.

scholarly journals Modulation of human type II secretory phospholipase A2 by sphingomyelin and annexin VI

1997 ◽  
Vol 326 (1) ◽  
pp. 227-233 ◽  
Author(s):  
Kamen KOUMANOV ◽  
Claude WOLF ◽  
Gilbert BÉREZIAT
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Phospholipase A2 ◽  
Cell Membranes ◽  
Red Cell ◽  
Type Ii ◽  
Membrane Phospholipids ◽  
Human Type ◽  
Annexin Vi ◽  
Hydrolysis Of

Conjectural results have been reported on the capacity of inflammatory secreted phospholipase A2 (sPLA2) to hydrolyse mammalian membrane phospholipids. Development of an assay based on the release of non-esterified fatty acids by the enzyme acting on the organized phospholipid mixture constituting the membrane matrix has led to the identification of two prominent effectors, sphingomyelin (SPH) and annexin. Recombinant human type II sPLA2 hydrolyses red-cell membrane phospholipids with a marked preference for the inner leaflet. This preference is apparently related to the high content of SPH in the outer leaflet, which inhibits sPLA2. This inhibition by SPH is specific for sPLA2. Cholesterol counteracts the inhibition of sPLA2 by SPH, suggesting that the SPH-to-cholesterol ratio accounts in vivo for the variable susceptibility of cell membranes to sPLA2. Different effects were observed of the presence of the non-hydrolysable D-α-dipalmitoyl phosphatidylcholine (D-DPPC), which renders the membranes rigid but does not inhibit sPLA2. Annexin VI was shown, along with other annexins, to inhibit sPLA2 activity by sequestering the phospholipid substrate. The present study has provided the first evidence that annexin VI, in concentrations that inhibit hydrolysis of purified phospholipid substrates, stimulated the hydrolysis of membrane phospholipids by sPLA2. The activation requires the presence of membrane proteins. The effect is specific for type II sPLA2 and is not reproducible with type I PLA2. The activation by annexin VI of sPLA2 acting on red cell membranes results in the preferential release of polyunsaturated fatty acids. It suggests that type II sPLA2, in conjunction with annexin VI, might be involved in the final step of endocytosis and/or exocytosis providing the free polyunsaturated fatty acids acting synergistically to cause membrane fusion.

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