Prostacyclin synthesis in irradiated endothelial cells cultured from bovine aorta

1985 ◽  
Vol 58 (2) ◽  
pp. 592-597 ◽  
Author(s):  
D. B. Rubin ◽  
E. A. Drab ◽  
C. H. Ts'ao ◽  
D. Gardner ◽  
W. F. Ward
Keyword(s):  
Endothelial Cells ◽  
Culture Media ◽  
Cell Detachment ◽  
Aortic Endothelial Cells ◽  
Endothelial Cell Surface ◽  
Ldh Activity ◽  
Platelet Adherence ◽  
Subendothelial Matrix ◽  
60Co Gamma Rays ◽  
And Control

Confluent monolayers of bovine aortic endothelial cells were examined 2–72 h after exposure to 0.5–5.0 Gy of 60Co gamma-rays. Accumulation of prostacyclin [PGI2, measured as 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha)] in the culture media and PGI2 production stimulated by exogenous arachidonate were correlated with cell detachment and release of lactate dehydrogenase (LDH) activity. Platelet adherence to irradiated and control monolayers also was studied. There were simultaneous time- and dose-dependent increases in cell detachment and in the titers of 6-keto-PGF1 alpha and LDH activity in the culture medium. These changes were evident between 4 and 8 h after 5 Gy or at 24 h after 0.5 Gy. Four hours after 5 Gy, both adherent and detached endothelial cells showed a twofold increase in PGI2 production during a 15-min incubation with arachidonate (10 microM). However, by 72 h this increase was less significant. The accumulation of 6-keto-PGF1 alpha appeared to be related to cell destruction, but radiation also stimulated PGI2 synthesis independent of cell detachment. There was an increased platelet interaction with irradiated monolayers, as a result of platelet adherence to subendothelial matrix exposed after cell detachment. However, irradiation did not alter the nonadherent property of the endothelial cell surface toward platelets.

CYCLOSPORIN A (CyA) INDUCED ENDOTHELIAL CELL INJURY

1987 ◽  
Author(s):  
C Zoja ◽  
L Furci ◽  
F Ghilardi ◽  
P Zilio ◽  
A Benigni ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Injury ◽  
Cell Damage ◽  
Chronic Administration ◽  
Endothelial Damage ◽  
Vascular Damage ◽  
Cell Detachment ◽  
Aortic Endothelial Cells ◽  
Specific Increase ◽  
Marked Cell

The chronic administration of CyA to animals and humans to prevent graft rejection may induce renal arteriolar damage resembling hemolytic uremic syndrome (HUS). This is a syndrome of vascular damage with thrombotic occlusions of the microcirculation. Endothelial damage is considered the first event in the pathogenetic cascade leading to HUS. We have used bovine aortic endothelial cells in culture to address the issue of CyA-induced arteriolar damage. CyA-induced a time (1-24 hours) and dose (1-50 μM) dependent cell damage. CyA-induced injury was characterized by an early cell detachment followed by lysis as documented by the increase in LDH and Cr release. 1 μM CyA did not induce cell detachment and lysis was evident only after prolonged incubations. 10 and 50 μM CyA both induced marked cell detachment and lysis: lysis started 3 hours after incubation of endothelial cells with CyA and was maximal at the end of 24 hour incubation (LDH release, percent specific increase over control values: 10 μM CyA, 47%; 50 μM CyA, 70%; 51 Cr release, percent specific increase over control values: 10 μM CyA, 28%; 50 μM CyA, 34%). CyA-induced injury was associated with dose- and time-depedent increase in prostacyclin (PGI2) and thromboxane A2 (TxA2) release by endothelial cells exposed to 10 and 50 μM CyA. CyA-induced generation of PGI2 and TxA2 was inhibited when the incubations were carried-on in the presence of acetyl salicilic acid (500 μM). These studies indicate that CyA exerts a direct toxic effect on endothelial cells and might help to understand the pathogenesis of CyA-induced vascular damage.

Regulation of protein l-isoaspartyl methyltransferase by cell–matrix interactions: involvement of integrin αvβ3, PI 3-kinase, and the proteasome

2006 ◽  
Vol 84 (5) ◽  
pp. 684-694 ◽  
Author(s):  
Julie Lanthier ◽  
Richard R. Desrosiers
Keyword(s):  
Endothelial Cells ◽  
Molecular Mechanisms ◽  
Cell Attachment ◽  
Proteasome Inhibitors ◽  
Integrin Αvβ3 ◽  
Pi3k Pathway ◽  
Cell Aging ◽  
Cell Detachment ◽  
Aortic Endothelial Cells ◽  
Isoaspartyl Methyltransferase

The enzyme l-isoaspartyl methyltransferase (PIMT) is known to repair damaged proteins that have accumulated abnormal aspartyl residues during cell aging. However, little is known about the mechanisms involved in the regulation of PIMT expression. Here we report that PIMT expression in bovine aortic endothelial cells is regulated by cell detachment and readhesion to a substratum. During cell detachment, the PIMT level was rapidly and strongly increased and correlated with a stimulation of protein synthesis. Aside from endothelial cells, PIMT levels were also regulated by cell adhesion in various cancer cell lines. The upregulation of PIMT expression could be prevented by an anti-αvβ3 antibody (LM609) or by a cyclic RGD peptide (XJ735) specific to integrin αvβ3, indicating that this integrin was likely involved in PIMT regulation. Moreover, we found that PIMT expression returned to the basal level when cells were replated on a substratum after detachment, though downregulation of PIMT expression could be partly prevented by the PI3K inhibitors LY294002 and wortmannin, as well as by the proteasome inhibitors MG-132, lactacystin, and β-lactone. These findings support the assumption that the PIMT level was downregulated by proteasomal degradation, involving the PI3K pathway, during cell attachment. This study reports new insights on the molecular mechanisms responsible for the regulation of PIMT expression in cells. The regulation of PIMT level upon cell-substratum contact suggests a potential role for PIMT in biological processes such as wound healing, cell migration, and tumor metastasis dissemination.

scholarly journals Histidine-rich glycoprotein does not interfere with interactions between antithrombin III and heparin-like compounds on vascular endothelial cells

Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 191-193 ◽  
Author(s):  
K Shimada ◽  
A Kawamoto ◽  
K Matsubayashi ◽  
T Ozawa
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Antithrombin Iii ◽  
Vascular Endothelial Cells ◽  
Anticoagulant Activity ◽  
Molar Ratio ◽  
Vascular Endothelial ◽  
Aortic Endothelial Cells ◽  
Endothelial Cell Surface

Abstract The role of histidine-rich glycoprotein in controlling heparin-like compounds on the endothelial cell surface is still unclear. The effects of this heparin-neutralizing protein on the interaction between antithrombin III and cultured porcine aortic endothelial cells were examined. Displacement of 125I-labeled antithrombin III specifically bound to endothelial cells by unlabeled histidine-rich glycoprotein was much less potent than that by unlabeled antithrombin III. One hundred- fold molar excess of histidine-rich glycoprotein displaced specific 125I-antithrombin III binding only by 20%. Furthermore, the endothelial cell-mediated acceleration of thrombin inactivation by antithrombin III was diminished by protamine sulfate, but was not affected by histidine- rich glycoprotein even at a histidine-rich glycoprotein/antithrombin III molar ratio of approximately 7:1. These data indicate that histidine-rich glycoprotein does not interfere with the interaction of endothelial cell heparin-like compounds with antithrombin III. Thus, it may not play an important role in the modulation of anticoagulant activity of endothelial cells in vivo, suggesting that the commonly accepted view of the probable function of this protein is erroneous.

scholarly journals Histidine-rich glycoprotein does not interfere with interactions between antithrombin III and heparin-like compounds on vascular endothelial cells

Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 191-193
Author(s):  
K Shimada ◽  
A Kawamoto ◽  
K Matsubayashi ◽  
T Ozawa
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Antithrombin Iii ◽  
Vascular Endothelial Cells ◽  
Anticoagulant Activity ◽  
Molar Ratio ◽  
Vascular Endothelial ◽  
Aortic Endothelial Cells ◽  
Endothelial Cell Surface

The role of histidine-rich glycoprotein in controlling heparin-like compounds on the endothelial cell surface is still unclear. The effects of this heparin-neutralizing protein on the interaction between antithrombin III and cultured porcine aortic endothelial cells were examined. Displacement of 125I-labeled antithrombin III specifically bound to endothelial cells by unlabeled histidine-rich glycoprotein was much less potent than that by unlabeled antithrombin III. One hundred- fold molar excess of histidine-rich glycoprotein displaced specific 125I-antithrombin III binding only by 20%. Furthermore, the endothelial cell-mediated acceleration of thrombin inactivation by antithrombin III was diminished by protamine sulfate, but was not affected by histidine- rich glycoprotein even at a histidine-rich glycoprotein/antithrombin III molar ratio of approximately 7:1. These data indicate that histidine-rich glycoprotein does not interfere with the interaction of endothelial cell heparin-like compounds with antithrombin III. Thus, it may not play an important role in the modulation of anticoagulant activity of endothelial cells in vivo, suggesting that the commonly accepted view of the probable function of this protein is erroneous.

Presence and secretion of atrial natriuretic peptide from cultured human aortic endothelial cells

1995 ◽  
Vol 268 (2) ◽  
pp. H921-H925 ◽  
Author(s):  
R. R. Brandt ◽  
D. M. Heublein ◽  
M. T. Mattingly ◽  
M. R. Pittelkow ◽  
J. C. Burnett
Keyword(s):  
Endothelial Cells ◽  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Vascular Tone ◽  
Culture Media ◽  
Aortic Endothelial Cells ◽  
Cell Extracts ◽  
Human Aortic Endothelial Cells ◽  
Atrial Natriuretic ◽  
Aortic Endothelial

The endothelium is the production site of several potent vasoactive substances that modulate vascular tone and growth. The present study was undertaken to investigate the presence and secretion of atrial natriuretic peptide (ANP) immunoreactivity from vascular endothelial cells. ANP immunoreactivity was present in cultured human aortic endothelial cells by both immunohistochemical staining and radioimmunoassay. ANP immunoreactivity was also detectable in culture medium from human aortic endothelial cells in low picogram concentrations. These findings suggest that vascular endothelium is a site of ANP production and secretion of ANP. There was a differential distribution of ANP and endothelin-1 (ET-1), with a higher ANP concentration in cell extracts and a higher ET-1 concentration in cell culture media. Although ANP has been conceived as a circulating endocrine hormone, these findings are consistent with ANP functioning also as an autocrine and paracrine modulator in the regulation of vascular tone and growth.

Convective Mass Transfer Effects on the Intracellular Calcium Response of Endothelial Cells

1992 ◽  
Vol 114 (3) ◽  
pp. 321-326 ◽  
Author(s):  
M. U. Nollert ◽  
L. V. McIntire
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Flow Rate ◽  
Parallel Plate ◽  
Cytosolic Calcium ◽  
Local Concentration ◽  
Aortic Endothelial Cells ◽  
Endothelial Cell Surface ◽  
Governing Differential Equation

Endothelial cells, which line the vasculature, respond to specific agonists such as adenosine triphosphate (ATP) by elevating cytosolic calcium levels and increasing production of the vasoactive compounds, prostacyclin and endothelial derived relaxing factor (EDRF). Endothelial cells express ecto-enzymes which metabolize ATP. If the activity of these enzymes is sufficiently high, then the concentration of ATP near the endothelial cell surface can be substantially lower than the bulk concentration. The ATP concentration is determined by a balance between the convection of fresh ATP from upstream and the degradation of ATP by the endothelial cells. In this report, we present a parallel plate flow system for measurement of cytosolic calcium levels ([Ca2+]i) of individual bovine aortic endothelial cells with the calcium sensitive fluorescent dye, fura-2. The cells respond to increases in the flow rate by increasing [Ca2+]i if there is ATP present in the perfusing buffer, but not in the absence of ATP. The amount of agonist in the perfusing fluid near the endothelial cell surface is estimated by solving the governing differential equation for the concentration profile of ATP in the parallel plate flow geometry. The solution indicates that one mechanism endothelial cells may use to detect changes in the flow rate is to respond to the change in the local concentration of agonist.

Characterization of a coronary vasoconstrictor produced by cultured endothelial cells

1985 ◽  
Vol 248 (5) ◽  
pp. C550-C556 ◽  
Author(s):  
K. A. Hickey ◽  
G. Rubanyi ◽  
R. J. Paul ◽  
R. F. Highsmith
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Culture Media ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Cholinergic Receptor ◽  
Isometric Tension ◽  
Smooth Muscle Contractility ◽  
Aortic Endothelial Cells

The vasoactive effects of media obtained from bovine aortic endothelial cells (EC) in culture were directly tested on isolated rings of the porcine left anterior descending coronary artery. Increasing concentrations of EC-conditioned culture media resulted in progressive dose-dependent increments in isometric tension in porcine, bovine, and canine coronary arteries; the response did not require an intact endothelium. Control (nonconditioned) media and that conditioned by fibroblasts or vascular smooth muscle cells in culture had negligible effects on vessel tone. The vasoconstriction required extracellular Ca2+ and was unaffected by inhibitors of cyclooxygenase and lipoxygenase or by antagonists to the alpha- or beta-adrenergic, serotonergic, histaminergic, or cholinergic receptor systems. Calibrated gel filtration of the media indicated a molecular weight of 8,500 for the vasoactive factor; treatment of the EC-conditioned media with either sodium dodecyl sulfate, trypsin, alkali, or with acid hydrolysis completely abolished the vasoconstrictive effect. These findings and others now provide evidence for the existence of an EC-derived polypeptide vasoconstrictor that may be important in the regulation of vascular smooth muscle contractility.

scholarly journals Binding of human xanthine oxidase to sulphated glycosaminoglycans on the endothelial-cell surface

1993 ◽  
Vol 289 (2) ◽  
pp. 523-527 ◽  
Author(s):  
T Adachi ◽  
T Fukushima ◽  
Y Usami ◽  
K Hirano
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Membrane ◽  
Xanthine Oxidase ◽  
Aortic Endothelial Cells ◽  
Endothelial Cell Surface ◽  
Arginine Residues ◽  
Sulphated Glycosaminoglycans ◽  
Porcine Aortic Endothelial Cells ◽  
Specific Reagent

Much evidence has suggested that the superoxide generated by xanthine oxidase (XOD) within the endothelial cell triggers characteristic free-radical-mediated tissue injuries. Although it has been reported that XOD exists not only in the cytoplasm, but also on the outside surface of the endothelial cell membrane, it is not clear how XOD localizes on the outside of the plasma membrane. Purified human xanthine oxidase (h-XOD) had an affinity for heparin-Sepharose. The binding was largely independent of the pH over the physiological range, whereas it tended to increase at lower pH and to decrease at higher pH. Exposure of h-XOD to the lysine-specific reagent trinitrobenzenesulphonic acid or the arginine-specific reagent phenylglyoxal caused it to lose its affinity for heparin-Sepharose. The binding of h-XOD to heparin is apparently of electrostatic nature, and both lysine and arginine residues are involved in the binding. h-XOD was found to bind to cultured porcine aortic endothelial cells, and this binding was inhibited by the addition of heparin or pretreatment of the cells with heparinase and/or heparitinase. Intravenous injection of heparin into two healthy persons led to a prompt increase in plasma h-XOD concentration. These results suggest that XOD localizes on the outside surface of endothelial cells by association with polysaccharide chains of heparin-like proteoglycans on the endothelial-cell membranes. Superoxide extracellularly generated by XOD may injure the source-endothelial-cell membrane and also attract and activate closely appositional neutrophils, which themselves actually cause progressive oxidative damage.

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