scholarly journals Composition of the von Willebrand factor storage organelle (Weibel-Palade body) isolated from cultured human umbilical vein endothelial cells.

1987 ◽  
Vol 104 (5) ◽  
pp. 1423-1433 ◽  
Author(s):  
B M Ewenstein ◽  
M J Warhol ◽  
R I Handin ◽  
J S Pober
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
High Molecular Weight ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Proteolytic Processing ◽  
Storage Organelle ◽  
Umbilical Vein Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

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.

Hydrogen peroxide stimulates exocytosis of von Willebrand factor in human umbilical vein endothelial cells

2017 ◽  
Vol 44 (5) ◽  
pp. 531-537 ◽  
Author(s):  
P. V. Avdonin ◽  
A. A. Tsitrina ◽  
G. Y. Mironova ◽  
P. P. Avdonin ◽  
I. L. Zharkikh ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Gamma-interferon modulates von Willebrand factor release by cultured human endothelial cells

Blood ◽  
1990 ◽  
Vol 75 (11) ◽  
pp. 2177-2184 ◽  
Author(s):  
SH Tannenbaum ◽  
HR Gralnick
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
High Molecular Weight ◽  
Von Willebrand Factor ◽  
Inflammatory Mediators ◽  
Interleukin 1 ◽  
Gamma Interferon ◽  
Human Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Endothelial cells (EC) synthesize and secrete von Willebrand factor (vWF), a multimeric glycoprotein required for normal hemostasis. Within human endothelial cells, vWF multimers of extremely high molecular weight are stored in rod-shaped organelles known as Weibel-Palade bodies. Inflammatory mediators, such as interleukin-1, induce in vitro a variety of procoagulant responses by EC, including the secretion of stored vWF. We postulated that other inflammatory mediators might act to balance this procoagulant reaction, thereby assisting in the maintenance of blood fluidity during immune activation. Both gamma- interferon (gamma-IFN) and tumor necrosis factor (TNF) were found to act independently and cooperatively to depress the stimulated release of vWF from EC. Analysis of stored vWF in either gamma-IFN and/or TNF- treated EC demonstrated a loss of high molecular weight multimers while immunofluorescent studies documented a loss of visible Weibel-Palade bodies. This suggests that gamma-IFN and TNF interfere with normal vWF storage. gamma-IFN acted in a dose-, time-, and RNA-dependent fashion, and its inhibition of vWF release was reversible with time. No effect of gamma-IFN on EC was noted when anti-serum to gamma-IFN was added. Unlike gamma-IFN, alpha-interferon did not effect EC vWF. Therefore, gamma-IFN and TNF may be important in decreasing vWF release during inflammatory or immunologic episodes.

THE EFFECT OF PHORBOL DIESTERS AND INTERLEUKINS ON THE SECRETION OF VON WILLEBRAND FACTOR BY HUMAN ENDOTHELIAL CELLS IN CULTURE

1987 ◽  
Author(s):  
J C Giddings ◽  
L Shall
Keyword(s):  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Interleukin 2 ◽  
Morphological Evidence ◽  
Adhesive Properties ◽  
Umbilical Vein Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

Human umbilical vein endothelial cells (EC) were cultured in the presence of 4p-phorbol 12-myristate 13-acetate (PMA, 10ug/l), interleukin 1 (IL-1, 1 unit/ml) and interleukin 2 (IL-2, 1 unit/ml), and secretion of von Willebrand factor activity (vWF, Ristocetin co-factor) and von Willebrand factor antigen (vWFAG, ELISA Technique) measured at intervals. Confluent control EC were treated with PMA, IL-1 and IL-2, and the supernatant medium assayed for release of vWF and vWFAg. Treated cells were also examined for vWFAg by immuno-fluorescence. The levels of both vWF and vWFAg in cultures containing IL-1 were significantly higher than those in control cultures after 5-6 days growth. Moreover, vWF and vWFAg increased significantly in the supernatant of confluent control EC incubated further in the presence of IL-1. Furthermore, the characteristic fluorescence pattern of endothelial vWFAg was markedly reduced in EC treated with IL-1. The levels of vWF and vWFAg in cultures containing PMA were also significantly higher than those of control cultures. In these conditions, however, the growth of cells appeared to be enhanced, and confluence was observed after about 6 days in the presence of PMA compared to 9 - 10 days in control cultures. The mean levels of vWF and vWFAg in the supernatant of EC incubated with PMA were higher than the control values but the differences were not statistically significant. Immunofluorescence of PMA-treated cells suggested that vWFAg might be less granular than in control cells but the differences were not as marked as those seen with IL-1. The results of all assays in the presence of IL-2 were not significantly different from those of control cells. In all instances no morphological evidence of endothelial injury was observed and more than 90% of cells remained viable at the termination of cultures. The results indicated that the synthesis and release of vWF were increased in the presence of PMA, and secretion of vWF was stimulated by IL-1. The data suggest that secreted vWF might contribute to the previously reported enhanced procoagulant and adhesive properties of EC treated with these substances.

scholarly journals Molecular studies of von Willebrand disease: reduced von Willebrand factor biosynthesis, storage, and release in endothelial cells derived from patients with type I von Willebrand disease [published erratum appears in Blood 1990 Nov 1;76(9):1901]

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1466-1472 ◽  
Author(s):  
BM Ewenstein ◽  
A Inbal ◽  
JS Pober ◽  
RI Handin
Keyword(s):  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
Messenger Rna ◽  
Umbilical Vein ◽  
Von Willebrand Disease ◽  
Type I ◽  
Molecular Defects ◽  
Umbilical Vein Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Endothelial cells were cultured from the umbilical veins of two neonates with type I von Willebrand disease (vWD) and compared with cells cultured in parallel from normal control umbilical veins. In both cases, cultured vWD endothelial cells contained less messenger RNA (mRNA) encoding von Willebrand factor (vWF), and constitutively secreted two- to fourfold less vWF protein than their matched controls. Regulated secretion of stored vWF induced by thrombin or phorbol-12- myristate-13-acetate (PMA) was also diminished in vWD cells. Both the mRNA and protein produced by each of these type I vWD cells appeared to be of normal size. However, despite the diminished size of the vWF storage pool, electron microscopy of endothelial cells in situ showed normal appearing vWF storage organelles (Weibel-Palade bodies). These studies show that cultured umbilical vein endothelial cells can be used to explore the molecular defects in type I and perhaps other forms of vWD, and suggest that at least some forms of type I vWD are caused by diminished mRNA transcription or subsequent translation due to a defective vWF allele.

scholarly journals Gamma-interferon modulates von Willebrand factor release by cultured human endothelial cells

Blood ◽  
1990 ◽  
Vol 75 (11) ◽  
pp. 2177-2184
Author(s):  
SH Tannenbaum ◽  
HR Gralnick
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
High Molecular Weight ◽  
Von Willebrand Factor ◽  
Inflammatory Mediators ◽  
Interleukin 1 ◽  
Gamma Interferon ◽  
Human Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

Endothelial cells (EC) synthesize and secrete von Willebrand factor (vWF), a multimeric glycoprotein required for normal hemostasis. Within human endothelial cells, vWF multimers of extremely high molecular weight are stored in rod-shaped organelles known as Weibel-Palade bodies. Inflammatory mediators, such as interleukin-1, induce in vitro a variety of procoagulant responses by EC, including the secretion of stored vWF. We postulated that other inflammatory mediators might act to balance this procoagulant reaction, thereby assisting in the maintenance of blood fluidity during immune activation. Both gamma- interferon (gamma-IFN) and tumor necrosis factor (TNF) were found to act independently and cooperatively to depress the stimulated release of vWF from EC. Analysis of stored vWF in either gamma-IFN and/or TNF- treated EC demonstrated a loss of high molecular weight multimers while immunofluorescent studies documented a loss of visible Weibel-Palade bodies. This suggests that gamma-IFN and TNF interfere with normal vWF storage. gamma-IFN acted in a dose-, time-, and RNA-dependent fashion, and its inhibition of vWF release was reversible with time. No effect of gamma-IFN on EC was noted when anti-serum to gamma-IFN was added. Unlike gamma-IFN, alpha-interferon did not effect EC vWF. Therefore, gamma-IFN and TNF may be important in decreasing vWF release during inflammatory or immunologic episodes.

INTACT MICROTUBULES ARE NECESSARY FOR COMPLETE PROCESSING, STORAGE AND REGULATED SECRETION OF VON WILLEBRAND FACTOR BY ENDOTHELIAL CELLS

1987 ◽  
Author(s):  
S Sinha ◽  
D D Wagner
Keyword(s):  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Regulated Secretion ◽  
Microtubular Cytoskeleton ◽  
Full Capacity ◽  
Umbilical Vein Endothelial Cells ◽  
Von Willebrand ◽  
Willebrand Factor

The importance of intact microtubules in the processing, storage and regulated secretion of von Willebrand factor (vWf) from Weibel-Palade bodies in endothelial cells was investigated. Human umbilical vein endothelial cells treated for one hour with colchicine (10-6M) or nocodozole (10-6M) lost their organized microtubular network. Stimulation of these cells with secretagogues (A23187, thrombin) produced only 30% release of vWf in comparison to control cells containing intact microtubules. The nocodazole treatment was reversible. One hour incubation in the absence of the drug was sufficient for microtubules to reform and to restore the full capacity of the cells to release vWf.Long-term incubation (24 hours) of endothelial cells with microtubule destabilizing agents had a profound effect on vWf distribution. In control cells vWf was localized to organelles in the perinuclear region (i.e. endoplasmic reticulum and Golgi apparatus) and to Weibel-Palade bodies. In drug-treated cells vWf staining was dispersed throughout the cytoplasm and Weibel-Palade bodies were absent. The vWf synthesized in the absence of microtubules contained significantly less large multimers than that produced by control cells. This was not due to possible side effects of the drugs on the cells because the presence of lumicolchicine, an inactive analogue of colchicine, had no effect on vWf processing. Since Weibel-Palade bodies specifically contain the large multimers (Sporn et al, Cell 46:185-190, 1986), we hypothesize that the structural defect in vWf secreted by cells in the absence of microtubules is due to the lack of Weibel-Palade bodies in these cultures.In summary, the intact microtubular cytoskeleton in the endothelial cells in culture, appeared to be crucial for normal release of Weibel-Palade bodies after stimulation with secretagogues, for reformation of new Weibel-Palade bodies and for the efficient intracellular multimerization of vWf dimeric molecules.

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