Endothelial cells internalize monoclonal antibody to angiotensin-converting enzyme

1996 ◽  
Vol 270 (5) ◽  
pp. L704-L713 ◽  
Author(s):  
V. R. Muzykantov ◽  
E. N. Atochina ◽  
A. Kuo ◽  
E. S. Barnathan ◽  
K. Notarfrancesco ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Umbilical Vein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Affinity Constant ◽  
Converting Enzyme

We investigated the fate of MAb 9B9, a monoclonal antibody to angiotensin-converting enzyme (ACE), which binds to endothelium both in vitro and in vivo. Using cultured human umbilical vein endothelial cells (HUVEC) and isolated perfused rat lungs (IPL), we demonstrated specific and saturable binding of 125I-labeled MAb 9B9 at 4 degrees C [affinity constant (Kd) = 20-50 nM, maximal number of binding sites (Bmax) = 1.5-3.0 x 10(5) sites/cell]. When 125I-MAb 9B9 was bound to HUVEC at 37 degrees C, only 40% of cell-associated radioactivity was acid elutable, suggesting antibody internalization. This was confirmed by finding that 1) the amount of MAb 9B9 uptake at 37 degrees C was higher than at 4 degrees C both in HUVEC and IPL; 2) binding of 125I-labeled streptavidin with HUVEC and IPL pretreated with biotinylated MAb 9B9 (b-MAb 9B9) was diminished in a temperature- and time-dependent fashion at 37 degrees C; and 3) b-MAb 9B9 bound to HUVEC at 37 degrees C was found intracellularly by ultrastructural analysis using streptavidin gold. Intracellular 125I-MAb 9B9 was found in microsomal fractions of lung homogenate from IPL and after intravenous (iv) injections in rats. Degradation of internalized MAb 9B9 was minimal, since > 90% of cell-associated 125I label remained precipitable by trichloracetic acid in HUVEC, IPL, and in vivo. Autoradiography of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of lung homogenates made as late as several days after iv injections of 125I-MAb 9B9 in rats demonstrated a predominant band above 140 kDa. These data indicate that endothelial cells either in vitro or in vivo internalize the ACE ligand MAb 9B9 without significant intracellular degradation. Therefore MAb 9B9 may be useful for selective intracellular delivery of drugs to the pulmonary vascular endothelium after systemic administration.

Endothelial cells from human umbilical vein secrete functional transcobalamin II

1989 ◽  
Vol 256 (2) ◽  
pp. C296-C303 ◽  
Author(s):  
E. V. Quadros ◽  
S. P. Rothenberg ◽  
E. A. Jaffe
Keyword(s):  
Endothelial Cells ◽  
Mammalian Cells ◽  
Umbilical Vein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells ◽  
Transcobalamin Ii

Transcobalamin II (TCII) is a cobalamin (Cbl) binding protein in the plasma that mediates the cellular uptake of Cbl. Although the synthesis of TCII by a variety of cultured mammalian cells and by some isolated perfused organs has been reported, no single tissue has been identified as the source of TCII in vivo. In this study, we demonstrate that cultured human umbilical vein endothelial cells secrete a protein that binds CN[57Co]Cbl, elutes from a Sephacryl S-200 column in the same position as TCII, and precipitates with an antiserum to purified human TCII. The biosynthesis of TCII by these cells was confirmed by demonstrating the incorporation of [35S]methionine into a nascent protein that immunoprecipitated with anti-TCII and which, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) had an Mr of 43,000, the same as human TCII. This secreted protein also had the functional properties of TCII because it facilitated the uptake of CN[57Co]Cbl by the same endothelial cells that secreted it as well as other cell lines that express the membrane receptor for TCII. We also present evidence that the venous endothelium could be the source of TCII in vivo by showing that an intact umbilical vein in an isolated umbilical cord, when perfused with medium containing [35S]methionine, secretes a radiolabeled nascent protein with the same immunoreactive and electrophoretic properties as human TCII. These studies demonstrate that the endothelial cell, which has been shown to secrete a number of plasma proteins, also synthesizes and secretes TCII both in vitro and as an intact endothelium in situ, and therefore, could be the source of circulating TCII in vivo.

scholarly journals Human endothelial cells synthesize, process, and secrete fibronectin molecules bearing an alternatively spliced type III homology (ED1)

Blood ◽  
1990 ◽  
Vol 75 (9) ◽  
pp. 1801-1808
Author(s):  
JH Peters ◽  
LA Sporn ◽  
MH Ginsberg ◽  
DD Wagner
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Primary Cultures ◽  
Sodium Dodecyl ◽  
Similar Rate ◽  
Soluble Form ◽  
Type Iii ◽  
Alternatively Spliced

Cellular fibronectin (Fn) bearing an alternatively spliced extra type III structural repeat (ED1) is normally present at low concentrations in blood plasma. The source of this material remains uncertain. In this study, primary cultures of human umbilical vein endothelial cells (HUVEC) labeled with 35S-methionine were observed to synthesize Fn monomers both with and without this segment. Monomers isolated from cell lysates with antibodies to the ED1 sequence comigrated in nonreduced sodium dodecyl sulfate polyacrylamide gel electrophoresis with the slower (designated M1), but not the faster (designated M2), of two major monomeric populations that were recognized by antibodies raised to plasma-derived Fn. The differences between M1 and M2 were not due to glycosylation, since they were also observed between species of Fn monomer purified from cells grown in the presence of tunicamycin. M1 and M2 were both observed to incorporate with a similar rate into dimeric Fn, indicating that Fn monomers with and without the ED1 site can dimerize with similar efficiency. Analysis of reduced samples of Fn isolated from cells with anti-ED1 antibodies indicated the presence of both M1-M1 and M1-M2 dimers. In addition to being incorporated into extracellular matrix, ED1 + Fn was observed to be secreted in soluble form into the medium, potentially reflecting intravascular release of this protein by endothelial cells in vivo.

Effect of Ginsenoside Rgl on the Release of Enzymes by Cultured Endothelial Cells

1992 ◽  
Vol 20 (01) ◽  
pp. 91-101 ◽  
Author(s):  
Yumiko Ushio
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Plasminogen Activator ◽  
Umbilical Vein ◽  
Surface Membrane ◽  
Morphological Alteration ◽  
Converting Enzyme ◽  
Promoting Effect ◽  
Umbilical Vein Endothelial Cells

The effects of ginsenoside Rgl, isolated from Ginseng Radix, on the secretion of plasminogen activator and angiotensin-converting enzyme from cultured human umbilical vein endothelial cells were investigated in vitro. Ginsenoside Rgl significantly increased the secretion of plasminogen activator from the cells both with and without stimulation of the cells by thrombin. Ginsenoside Rgl also remarkably induced the secretion of angiotensin-converting enzyme from the cells. Furthermore, ginsensoside Rgl showed some morphological alteration in the surface membrane of the cells. In addition, survival-promoting effect of CPAE cell line by ginsenoside Rgl was observed.

scholarly journals Angiotensin-converting enzyme inhibitors attenuate propofol-induced pro-oxidative and antifibrinolytic effect in human endothelial cells

2017 ◽  
Vol 18 (1) ◽  
pp. 147032031668719 ◽  
Author(s):  
Marzena Wojewodzka-Zelezniakowicz ◽  
Anna Gromotowicz-Poplawska ◽  
Wioleta Kisiel ◽  
Emilia Konarzewska ◽  
Janusz Szemraj ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Enzyme Inhibitors ◽  
Umbilical Vein ◽  
Angiotensin Converting Enzyme Inhibitors ◽  
Mrna Levels ◽  
Converting Enzyme ◽  
Converting Enzyme Inhibitors

Introduction: The aim of this study was to investigate the effects of plasma and tissue angiotensin-converting enzyme inhibitors (ACE-Is) against propofol-induced endothelial dysfunction and to elucidate the involved mechanisms in vitro. Materials and methods: We examined the effects of propofol (50 μM), quinaprilat and enalaprilat (10−5 M) on fibrinolysis (t-PA, PAI-1, TAFI antigen levels), oxidative stress parameters (H2O2 and MDA antigen levels and SOD and NADPH oxidase mRNA levels) and nitric oxide bioavailability (NO2/NO3 concentration and NOS expression at the level of mRNA) in human umbilical vein endothelial cells (HUVECs). Results: We found that both ACE-Is promoted similar endothelial fibrinolytic properties and decreased oxidative stress in vitro. Propofol alone increased the release of antifibrinolytic and pro-oxidative factors from the endothelium and increased mRNA iNOS expression. We also found that the incubation of HUVECs in the presence of propofol following ACE-Is pre-incubation caused weakness of the antifibrinolytic and pro-oxidative potential of propofol and this effect was similar after both ACE-Is. Conclusions: This observation suggests that the studied ACE-Is exerted protective effects against endothelial cell dysfunction caused by propofol, independently of hemodynamics.

Rat intestinal angiotensin-converting enzyme: purification, properties, expression, and function

1992 ◽  
Vol 263 (4) ◽  
pp. G466-G473 ◽  
Author(s):  
R. H. Erickson ◽  
Y. Suzuki ◽  
A. Sedlmayer ◽  
I. S. Song ◽  
Y. S. Kim
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Maximal Velocity ◽  
Converting Enzyme ◽  
And Function

Angiotensin-converting enzyme [ACE (peptidyl-dipeptidase A, EC 3.4.15.1)] was purified from a total cell membrane fraction of rat intestinal mucosa. A 4,500-fold purification was achieved after affinity chromatography with lisinopril-Sepharose and gel filtration. The final preparation was judged to be homogenous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 160,000. The purified protein is a glycoenzyme containing 12% N-linked carbohydrate. Purified ACE had a specific activity of 65 U/mg protein with benzoyl-Gly-His-Leu as substrate. A kinetic analysis showed that the enzyme had the maximal velocity with substrates containing proline at the COOH-terminal end. Inhibitor studies indicated that the enzyme is a metalloprotein. Along the proximal-distal axis of the small intestine, ACE activity is most predominant in the proximal to middle portions, decreasing toward the distal end. This pattern was also observed for ACE mRNA and protein, suggesting that ACE expression is controlled at the level of mRNA. Perfusion of benzoyl-Gly-His-Leu in vivo through a segment of intestinal jejunum demonstrated that ACE is an important intestinal dipeptidyl carboxypeptidase, participating in the digestion and assimilation of dietary peptides.

scholarly journals Human endothelial cells synthesize, process, and secrete fibronectin molecules bearing an alternatively spliced type III homology (ED1)

Blood ◽  
1990 ◽  
Vol 75 (9) ◽  
pp. 1801-1808 ◽  
Author(s):  
JH Peters ◽  
LA Sporn ◽  
MH Ginsberg ◽  
DD Wagner
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Primary Cultures ◽  
Sodium Dodecyl ◽  
Similar Rate ◽  
Soluble Form ◽  
Type Iii ◽  
Alternatively Spliced

Abstract Cellular fibronectin (Fn) bearing an alternatively spliced extra type III structural repeat (ED1) is normally present at low concentrations in blood plasma. The source of this material remains uncertain. In this study, primary cultures of human umbilical vein endothelial cells (HUVEC) labeled with 35S-methionine were observed to synthesize Fn monomers both with and without this segment. Monomers isolated from cell lysates with antibodies to the ED1 sequence comigrated in nonreduced sodium dodecyl sulfate polyacrylamide gel electrophoresis with the slower (designated M1), but not the faster (designated M2), of two major monomeric populations that were recognized by antibodies raised to plasma-derived Fn. The differences between M1 and M2 were not due to glycosylation, since they were also observed between species of Fn monomer purified from cells grown in the presence of tunicamycin. M1 and M2 were both observed to incorporate with a similar rate into dimeric Fn, indicating that Fn monomers with and without the ED1 site can dimerize with similar efficiency. Analysis of reduced samples of Fn isolated from cells with anti-ED1 antibodies indicated the presence of both M1-M1 and M1-M2 dimers. In addition to being incorporated into extracellular matrix, ED1 + Fn was observed to be secreted in soluble form into the medium, potentially reflecting intravascular release of this protein by endothelial cells in vivo.

Production of a Monoclonal Antibody against Canine GMP-140 (P-Selectin) and Studies of Its Vascular Distribution in Canine Tissues

1993 ◽  
Vol 30 (3) ◽  
pp. 213-222 ◽  
Author(s):  
M. Doré ◽  
H. K. Hawkins ◽  
M. L. Entman ◽  
C. W. Smith
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Adhesion Molecule ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Flow Cytometric Analysis ◽  
Coagulation System ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Beings

Rapid upregulation of the adhesion molecule GMP-140 (P-selectin) on endothelial cells is believed to play an important role in the initial binding of leukocytes to endothelium, a very early step in the inflammatory response. Activated platelets that are involved in the coagulation system and in inflammatory processes also express GMP-140 on their surfaces. The objectives of the present study were to develop a monoclonal antibody against this adhesion molecule in the dog and to use this antibody to study platelet–neutrophil interactions in whole blood and to characterize the in vivo localization of GMP-140 in canine tissues. Five Balb/c mice were immunized with thrombin-stimulated dog platelets, and clones were screened using an enzyme-linked immunosorbent assay. The clone MD3 (IgG1) showed preferential binding to activated as compared with resting platelets. Flow cytometric analysis using MD3 revealed that 27% of circulating neutrophils in unstimulated blood had platelets bound to their surfaces; stimulation with platelet activating factor increased this percentage to 85%. Immunoblot analysis of solubilized dog platelets resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that the antibody MD3 recognized an approximately 140-kd protein. Immunohistochemical study of normal dog tissues with MD3 revealed that the antigen was present in endothelial cells of arteries, capillaries, and veins, depending on the specific tissue examined. Blood vessels staining positively with MD3 were most abundant in the digestive system (liver, stomach, small and large intestines), moderate in the lungs, kidneys, spleen, lymph nodes, and endocrine glands, and minimal in the brain, myocardium, skeletal system, and skin. Based on its presence on stimulated but not resting platelets, its molecular weight, and its vascular distribution, the antigen recognized by MD3 appears to be the selectin GMP-140 of the dog. This study documents that the cellular and tissue distribution of GMP-140 in dogs is very similar to that in human beings.

Desmopressin (DDAVP) Enhances Platelet Adhesion to the Extracellular Matrix of Cultured Human Endothelial Cells through Increased Expression of Tissue Factor

1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Platelet Adhesion ◽  
Umbilical Vein ◽  
Procoagulant Activity ◽  
Experimental Conditions ◽  
Chromogenic Assay

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.

Epinephrine Induces von Willebrand Factor Release from Cultured Endothelial Cells: Involvement of Cyclic AMP-dependent Signalling in Exocytosis

1997 ◽  
Vol 77 (06) ◽  
pp. 1182-1188 ◽  
Author(s):  
Ulrich M Vischer ◽  
Claes B Wollheinn
Keyword(s):  
Endothelial Cells ◽  
Adenylate Cyclase ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Free Calcium ◽  
Camp Content ◽  
Von Willebrand ◽  
Willebrand Factor

Summaryvon Willebrand factor (vWf) is released from endothelial cell storage granules after stimulation with thrombin, histamine and several other agents that induce an increase in cytosolic free calcium ([Ca2+]i). In vivo, epinephrine and the vasopressin analog DDAVP increase vWf plasma levels, although they are thought not to induce vWf release from endothelial cells in vitro. Since these agents act via a cAMP-dependent pathway in responsive cells, we examined the role of cAMP in vWf secretion from cultured human umbilical vein endothelial cells. vWf release increased by 50% in response to forskolin, which activates adenylate cyclase. The response to forskolin was much stronger when cAMP degradation was blocked with IBMX, an inhibitor of phosphodiesterases (+200%), whereas IBMX alone had no effect. vWf release could also be induced by the cAMP analogs dibutyryl-cAMP (+40%) and 8-bromo-cAMP (+25%); although their effect was weak, they clearly potentiated the response to thrombin. Epinephrine (together with IBMX) caused a small, dose-dependent increase in vWf release, maximal at 10-6 M (+50%), and also potentiated the response to thrombin. This effect is mediated by adenylate cyclase-coupled β-adrenergic receptors, since it is inhibited by propranolol and mimicked by isoproterenol. In contrast to thrombin, neither forskolin nor epinephrine caused an increase in [Ca2+]j as measured by fura-2 fluorescence. In addition, the effects of forskolin and thrombin were additive, suggesting that they act through distinct signaling pathways. We found a close correlation between cellular cAMP content and vWf release after stimulation with epinephrine and forskolin. These results demonstrate that cAMP-dependent signaling events are involved in the control of exocytosis from endothelial cells (an effect not mediated by an increase in [Ca2+]i) and provide an explanation for epinephrine-induced vWf release.

scholarly journals Generation of a Novel In Vitro Model to Study Endothelial Dysfunction from Atherothrombotic Specimens

2021 ◽  
Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
In Vitro Model ◽  
Umbilical Vein ◽  
Coronary Syndrome ◽  
Coronary Endothelial Cells ◽  
Vitro Model ◽  
Umbilical Vein Endothelial Cells

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.

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