scholarly journals Human Endothelial Cells in Culture and In Vivo Express on Their Surface All Four Components of the Glycoprotein Ib/IX/V Complex

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2660-2669 ◽  
Author(s):  
Guoxin Wu ◽  
David W. Essex ◽  
Frank J. Meloni ◽  
Toshiro Takafuta ◽  
Kingo Fujimura ◽  
...  

The platelet glycoprotein Ib (GpIb) complex is composed of four polypeptides: the disulfide-linked GpIbα and GpIbβ and the noncovalently associated GpIX and GpV. GpIbα contains binding sites for von Willebrand factor and for thrombin and mediates platelet adhesion to the subendothelium under conditions of high shear stress. We have previously shown the presence of GpIbα and GpIbβ mRNA and protein in cultured human umbilical vein endothelial cells (HUVECs) as well as the presence of GpIbα mRNA and protein in tonsillar endothelium. We, therefore, probed ECs for the presence of the other components of the GpIb/IX/V complex. We have identified the presence of GpIX and GpV mRNA in cultured HUVEC monolayers. The sequence of HUVEC GpIX cDNA was identical to the previously published human erythroleukemia (HEL) cell GpIX cDNA sequence. Two species of GpV mRNA, one of 3 kb and one of 4.4 kb, were found in HUVECs, whereas HEL cells displayed only the 4.4-kb species and the megakaryocytic cell line CHRF-288 contained only the 3-kb species. We previously showed that EC GpIbα protein is identical in molecular weight to platelet GpIbα. HUVEC GpIbβ, in contrast to its platelet counterpart, has a molecular weight of 50 kD and forms a correspondingly larger disulfide-bonded complex with EC GpIbα. The molecular weights of GpIX and GpV were 22 and 88 kD, respectively, identical to the corresponding platelet polypeptides. Furthermore, we have identified all four components of the complex in tonsillar vessels. Using flow cytometry, we have established that all four polypeptides of the GpIb/IX/V complex are expressed on the surface membranes of cultured HUVECs and adult aortic ECs. Furthermore, using two-color fluorescence, we have shown that all ECs expressing GpIbα also express GpIX and GpV on their surface. The ratio of GpIbα:GpIX:GpV is 1:1:0.5, which is identical to the ratio present in platelets. None of the polypeptides of the GpIb complex could be identified on the surface of human smooth muscle cells or lymphocytes. The presence of all members of the GpIb complex in the EC membrane suggests that this complex may play a role in endothelial function in vivo.

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2660-2669 ◽  
Author(s):  
Guoxin Wu ◽  
David W. Essex ◽  
Frank J. Meloni ◽  
Toshiro Takafuta ◽  
Kingo Fujimura ◽  
...  

AbstractThe platelet glycoprotein Ib (GpIb) complex is composed of four polypeptides: the disulfide-linked GpIbα and GpIbβ and the noncovalently associated GpIX and GpV. GpIbα contains binding sites for von Willebrand factor and for thrombin and mediates platelet adhesion to the subendothelium under conditions of high shear stress. We have previously shown the presence of GpIbα and GpIbβ mRNA and protein in cultured human umbilical vein endothelial cells (HUVECs) as well as the presence of GpIbα mRNA and protein in tonsillar endothelium. We, therefore, probed ECs for the presence of the other components of the GpIb/IX/V complex. We have identified the presence of GpIX and GpV mRNA in cultured HUVEC monolayers. The sequence of HUVEC GpIX cDNA was identical to the previously published human erythroleukemia (HEL) cell GpIX cDNA sequence. Two species of GpV mRNA, one of 3 kb and one of 4.4 kb, were found in HUVECs, whereas HEL cells displayed only the 4.4-kb species and the megakaryocytic cell line CHRF-288 contained only the 3-kb species. We previously showed that EC GpIbα protein is identical in molecular weight to platelet GpIbα. HUVEC GpIbβ, in contrast to its platelet counterpart, has a molecular weight of 50 kD and forms a correspondingly larger disulfide-bonded complex with EC GpIbα. The molecular weights of GpIX and GpV were 22 and 88 kD, respectively, identical to the corresponding platelet polypeptides. Furthermore, we have identified all four components of the complex in tonsillar vessels. Using flow cytometry, we have established that all four polypeptides of the GpIb/IX/V complex are expressed on the surface membranes of cultured HUVECs and adult aortic ECs. Furthermore, using two-color fluorescence, we have shown that all ECs expressing GpIbα also express GpIX and GpV on their surface. The ratio of GpIbα:GpIX:GpV is 1:1:0.5, which is identical to the ratio present in platelets. None of the polypeptides of the GpIb complex could be identified on the surface of human smooth muscle cells or lymphocytes. The presence of all members of the GpIb complex in the EC membrane suggests that this complex may play a role in endothelial function in vivo.


Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 234-237 ◽  
Author(s):  
JD Sprandio ◽  
SS Shapiro ◽  
P Thiagarajan ◽  
S McCord

Using a platelet glycoprotein Ib (GpIb)-specific monoclonal antibody, AP-1, we have studied cultured human umbilical vein endothelial cells (HUVEC) for the presence of GpIb. Radiolabeled AP-1 bound specifically and saturably to HUVEC in suspension and detected a single class of binding sites (100,000/cell). When Triton X-100 extracts of HUVEC were chromatographed on wheat germ agglutinin (WGA)-Sepharose, radioiodinated, precipitated with AP-1, and subjected to reduced sodium dodecyl sulfate-polyacrylamide electrophoresis (SDS-PAGE), major radioactive bands of 228,000, 145,000, and 130,000 were seen. The latter two bands correspond to the 156,000 and 140,000 bands, representing GpIb alpha and glycocalicin, respectively, which are seen when platelets are subjected to the same procedure. The 228,000 band corresponds to a band previously noted in immunoprecipitates of platelet GpIb but not fully explained. When HUVEC were grown in the presence of 35S-methionine, extracted with Triton X-100, chromatographed on WGA-Sepharose, immunoprecipitated with AP-1, and subjected to reduced SDS-PAGE, radioactive bands of 210,000, 156,000, and 90,000 were seen. We conclude that cultured HUVEC synthesize and express on their surface a glycoprotein immunologically related to platelet GpIb.


1987 ◽  
Vol 104 (5) ◽  
pp. 1423-1433 ◽  
Author(s):  
B M Ewenstein ◽  
M J Warhol ◽  
R I Handin ◽  
J S Pober

von Willebrand factor (VWF) is a large, adhesive glycoprotein that is biosynthesized and secreted by cultured endothelial cells (EC). Although these cells constitutively release VWF, they also contain a storage pool of this protein that can be rapidly mobilized. In this study, a dense organelle fraction was isolated from cultured umbilical vein endothelial cells by centrifugation on a self-generated Percoll gradient. Stimulation of EC by 4-phorbol 12-myristate 13-acetate (PMA) resulted in the disappearance of this organelle fraction and the synchronous loss of Weibel-Palade bodies as judged by immunoelectron microscopy. Electrophoretic and serologic analyses of biosynthetically labeled dense organelle fraction revealed that it is comprised almost exclusively of VWF and its cleaved pro sequence. These two polypeptides were similarly localized exclusively to Weibel-Palade bodies by ultrastructural immunocytochemistry. The identity of the dense organelle as the Weibel-Palade body was further established by direct morphological examination of the dense organelle fraction. The VWF derived from this organelle is distributed among unusually high molecular weight multimers composed of fully processed monomeric subunits and is rapidly and quantitatively secreted in unmodified form after PMA stimulation. These studies: establish that the Weibel-Palade body is the endothelial-specific storage organelle for regulated VWF secretion; demonstrate that in cultured EC, the VWF concentrated in secretory organelles is of unusually high molecular weight and that this material may be rapidly mobilized in unmodified form; imply that proteolytic processing of VWF involved in regulated secretion takes place after translocation to the secretory organelle; provide a basis for further studies of intracellular protein trafficking in EC.


Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 234-237 ◽  
Author(s):  
JD Sprandio ◽  
SS Shapiro ◽  
P Thiagarajan ◽  
S McCord

Abstract Using a platelet glycoprotein Ib (GpIb)-specific monoclonal antibody, AP-1, we have studied cultured human umbilical vein endothelial cells (HUVEC) for the presence of GpIb. Radiolabeled AP-1 bound specifically and saturably to HUVEC in suspension and detected a single class of binding sites (100,000/cell). When Triton X-100 extracts of HUVEC were chromatographed on wheat germ agglutinin (WGA)-Sepharose, radioiodinated, precipitated with AP-1, and subjected to reduced sodium dodecyl sulfate-polyacrylamide electrophoresis (SDS-PAGE), major radioactive bands of 228,000, 145,000, and 130,000 were seen. The latter two bands correspond to the 156,000 and 140,000 bands, representing GpIb alpha and glycocalicin, respectively, which are seen when platelets are subjected to the same procedure. The 228,000 band corresponds to a band previously noted in immunoprecipitates of platelet GpIb but not fully explained. When HUVEC were grown in the presence of 35S-methionine, extracted with Triton X-100, chromatographed on WGA-Sepharose, immunoprecipitated with AP-1, and subjected to reduced SDS-PAGE, radioactive bands of 210,000, 156,000, and 90,000 were seen. We conclude that cultured HUVEC synthesize and express on their surface a glycoprotein immunologically related to platelet GpIb.


1987 ◽  
Vol 105 (4) ◽  
pp. 1885-1892 ◽  
Author(s):  
C S Chen ◽  
P Thiagarajan ◽  
S M Schwartz ◽  
J M Harlan ◽  
R L Heimark

On platelets the membrane glycoprotein IIb/IIIa complex (GPIIb/IIIa) functions in adhesive interactions with fibrinogen, von Willebrand factor, and fibronectin. However, the function of GPIIb/IIIa-like proteins on endothelial cells, as well as the ligand(s) the complex binds, is unknown. Using a highly specific polyclonal antibody we have explored the function of GPIIb/IIIa-like proteins on human umbilical vein endothelial cells (HUVE). Analysis by immunoblotting shows that this antiserum recognizes the endothelial GPIIIa-like protein of the complex. The IgG fraction of the polyclonal antiserum and its Fab' fragments detach confluent and subconfluent HUVE from extracellular substrata. The effect of the anti-GPIIb/IIIa IgG is not toxic as the detached cells maintain their viability after trypsinization and replating. Anti-GPIIb/IIIa IgG does not inhibit HUVE binding to extracellular matrix or purified fibronectin in an attachment assay despite the presence of intact GPIIb/IIIa on HUVE detached from substrate by various methods. Apparently, the GPIIb/IIIa-like protein on HUVE is important in normal HUVE adhesion to the extracellular matrix, but it is not required in the initial attachment of HUVE to extracellular matrix.


1989 ◽  
Vol 61 (01) ◽  
pp. 101-105 ◽  
Author(s):  
Bonnie J Warn-Cramer ◽  
Fanny E Almus ◽  
Samuel I Rapaport

SummaryCultured human umbilical vein endothelial cells (HUVEC) have been reported to produce extrinsic pathway inhibitor (EPI), the factor Xa-dependent inhibitor of factor VHa/tissue factor (TF). We examined the release of this inhibitor from HUVEC as a function of their growth state and in response to the induction of endothelial cell TF activity. HUVEC constitutively produced significant amounts of EPI at all stages of their growth in culture including the post-confluent state. Rate of release varied over a 3-fold range for primary cultures from 12 different batches of pooled umbilical cord cells. Constitutive EPI release was unaltered during a 6 hour period of induction of TF activity with thrombin or phorbol ester but slowed during longer incubation of the cells with phorbol ester. Whereas plasma contains two molecular weight forms of EPI, only the higher of these two molecular weight forms was demonstrable by Western analysis of HUVEC supernatants with 125I-factor Xa as the ligand.


1995 ◽  
Vol 73 (02) ◽  
pp. 309-317 ◽  
Author(s):  
Dorothy A Beacham ◽  
Miguel A Cruz ◽  
Robert I Handin

SummaryIntroduction of single amino acid substitutions into the C-terminal Arg-Gly-Asp-Ser (RGDS) site of von Willebrand Factor, referred to as RGD mutant vWF, selectively abrogated vWF binding to platelet glycoprotein IIb/IIIa (GpIIb/IIIa, αIIbβ3 and abolished human umbilical vein endothelial cell (HUVEC) spreading, but not attachment, to RGD mutant vWF (Beacham, D. A., Wise, R. J., Turci, S. M. and Handin, R. I. 1992. J. Biol. Chem. 167, 3409-3415). These results suggested that in addition to the vitronectin receptor (VNR, αvβ3), a second endothelial membrane glycoprotein can mediate HUVEC adhesion to vWF. HUVEC attachment to wild-type (WT) and RGD-mutant vWF was reduced by two proteins known to block the vWF-platelet glycoprotein Ib/IX (GpIb/IX) interaction, the monoclonal antibody AS-7 and the recombinant polypeptide, vWF-A1. The addition of cytochalasin B or DNase I to disrupt potential GPIbα-cytoskeletal interactions enhanced the immunoprecipitation of endothelial GPIbα, caused HUVEC to round up, and increased HUVEC adhesion to RGD mutant vWF. These results indicate that while the VNR is the primary adhesion receptor for vWF, endothelial GPIbα can mediate HUVEC attachment to vWF. GpIb-dependent attachment could contribute to HUVEC adhesion under conditions when cell surface expression of the VNR is downregulated, and VNR-dependent adhesion is reduced.


1997 ◽  
Vol 77 (06) ◽  
pp. 1182-1188 ◽  
Author(s):  
Ulrich M Vischer ◽  
Claes B Wollheinn

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.


Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

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.


2005 ◽  
Vol 289 (4) ◽  
pp. H1669-H1675 ◽  
Author(s):  
John P. Cullen ◽  
Shariq Sayeed ◽  
Ying Jin ◽  
Nicholas G. Theodorakis ◽  
James V. Sitzmann ◽  
...  

The aim of this study was to determine the effect of ethanol (EtOH) on endothelial monocyte chemotactic protein-1 (MCP-1) expression. IL-1β increased the production of MCP-1 by human umbilical vein endothelial cells from undetectable levels to ∼900 pg/ml at 24 h. EtOH dose-dependently inhibited IL-1β-stimulated MCP-1 secretion as determined by ELISA: 25 ± 1%, 35 ± 7%, and 65 ± 5% inhibition for 1, 10, and 100 mM EtOH, respectively, concomitant with inhibition of monocyte adhesion to activated endothelial cells. Similarly, EtOH dose-dependently inhibited IL-1β-stimulated MCP-1 mRNA expression. Experiments with actinomycin D demonstrated that EtOH decreased the stability of MCP-1 mRNA. In addition, EtOH significantly reduced NF-κB and AP-1 binding activity induced by IL-1β and inhibited MCP-1 gene transcription. Binding of 125I-labeled MCP-1 to its receptor (CCR2) on THP-1 human monocytic cells was not affected by EtOH treatment. Modulation of the expression of MCP-1 represents a mechanism whereby EtOH could inhibit atherogenesis by blocking the crucial early step of monocyte adhesion and subsequent recruitment to the subendothelial space. These actions of EtOH may underlie, in part, its cardiovascular protective effects in vivo.


Sign in / Sign up

Export Citation Format

Share Document