Time Course and Quantification of Extracellular Matrix Maturation in the Chick Chorioallantoic Membrane and in Cultured Endothelial Cells

Endothelium ◽  
1993 ◽  
Vol 1 (3) ◽  
pp. 207-219 ◽  
Author(s):  
E. Papadimitriou ◽  
B. R. Unsworth ◽  
M. E. Maragoudakis ◽  
P. I. Lelkes
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Time Course ◽  
Chorioallantoic Membrane ◽  
Chick Chorioallantoic Membrane ◽  
Cultured Endothelial Cells ◽  
Matrix Maturation

scholarly journals von Willebrand factor released from Weibel-Palade bodies binds more avidly to extracellular matrix than that secreted constitutively

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1531-1534 ◽  
Author(s):  
LA Sporn ◽  
VJ Marder ◽  
DD Wagner
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
Immunofluorescent Staining ◽  
Cultured Endothelial Cells ◽  
Human Foreskin Fibroblasts ◽  
Platelet Binding ◽  
The Matrix ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Large multimers of von Willebrand factor (vWf) are released from the Weibel-Palade bodies of cultured endothelial cells following treatment with a secretagogue (Sporn et al, Cell 46:185, 1986). These multimers were shown by immunofluorescent staining to bind more extensively to the extracellular matrix of human foreskin fibroblasts than constitutively secreted vWf, which is composed predominantly of dimeric molecules. Increased binding of A23187-released vWf was not due to another component present in the releasate, since releasate from which vWf was adsorbed, when added together with constitutively secreted vWf, did not promote binding. When iodinated plasma vWf was overlaid onto the fibroblasts, the large forms bound preferentially to the matrix. These results indicated that the enhanced binding of the vWf released from the Weibel-Palade bodies was likely due to its large multimeric size. It appears that multivalency is an important component of vWf interaction with the extracellular matrix, just as has been shown for vWf interaction with platelets. The pool of vWf contained within the Weibel-Palade bodies, therefore, is not only especially suited for platelet binding, but also for interaction with the extracellular matrix.

scholarly journals Evidence that tenascin and thrombospondin-1 modulate sprouting of endothelial cells

1995 ◽  
Vol 108 (2) ◽  
pp. 797-809 ◽  
Author(s):  
A.E. Canfield ◽  
A.M. Schor
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Cell Growth ◽  
Aortic Endothelial Cells ◽  
Specific Antibodies ◽  
Reversible Transition ◽  
Bovine Aortic Endothelial Cells ◽  
Cultured Endothelial Cells ◽  
Thrombospondin 1 ◽  
Aortic Endothelial

Cultured endothelial cells undergo a reversible transition from a resting (cobblestone) phenotype to an angiogenic (sprouting) phenotype. This transition mimics the early events of angiogenesis. We have previously reported that the addition of exogenous xylosides inhibits endothelial cel sprouting and modifies the extracellular matrix (ECM) synthesised by the cells. We have now investigated whether endothelial sprouting is mediated by the nature of the extracellular matrix in contact with the cells. Accordingly, cell-free matrices deposited by bovine aortic endothelial cells (BAEC) were isolated. These matrices were produced under conditions in which the formation of the sprouting phenotype was permitted (controls) or inhibited (by the addition of exogenous xylosides). BAEC were then plated on these matrices and grown under conditions which promote sprouting. Sprouting proceeded normally on control matrices, whereas it was inhibited when the cells were grown on matrices deposited in the presence of xylosides. The composition of the permissive and inhibitory matrices was then analysed. Inhibitory matrices contained reduced levels of tenascin and increased levels of thrombospondin-1 by comparison to the permissive matrices. In contrast, no differences were detected in the relative levels of laminin. The roles of tenascin and thrombospondin-1 in endothelial sprouting were confirmed using specific antibodies. Immunolocalisation studies revealed the presence of both proteins in sprouting cells. Antibodies to tenascin inhibited the formation of sprouting cells on permissive matrices and on gelatin-coated dishes without affecting cell growth. Tenascin synthesis was increased when sprouting cells were present in the cultures. Antibodies to thrombospondin-1 stimulated sprouting on inhibitory matrices. These results suggest that the transition from a resting to a sprouting phenotype is promoted by tenascin and inhibited by thrombospondin-1.

scholarly journals Procoagulant activity of endotoxin-treated human endothelial cells exposed to native human flowing blood

Blood ◽  
1989 ◽  
Vol 73 (3) ◽  
pp. 729-733 ◽  
Author(s):  
M Clozel ◽  
H Kuhn ◽  
HR Baumgartner
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Shear Rate ◽  
Fibrin Deposition ◽  
Human Endothelial Cells ◽  
Cellular Activation ◽  
Shear Rates ◽  
Fibrin Formation ◽  
Cultured Endothelial Cells ◽  
Flowing Blood

Abstract It has been reported that cultured endothelial cells become procoagulant when exposed to endotoxin. This prompted us to investigate whether human endothelial cells treated with endotoxin could promote the generation of fibrin when exposed to human flowing blood. For this purpose we used a parallel-plate perfusion chamber in which confluent cultured endothelial cells from human umbilical veins were exposed for five minutes to directly drawn human nonanticoagulated blood, at wall shear rates of 100, 650, and 2600 sec-1. Fibrin deposition was assessed by morphometry. No fibrin deposition occurred on normal endothelial cells. In contrast, cells incubated with endotoxin for 4 or 18 hours induced fibrin deposition, but only at a shear rate of 100 sec-1. Since some extracellular matrix was exposed between the cells, we investigated whether extracellular matrix played a role in fibrin formation. When the endothelial cells incubated or not with endotoxin were removed by EDTA, the exposed extracellular matrix perfused with blood at 100 sec-1 supported platelet and fibrin deposition in both cases. This suggests that the effect of endotoxin on endothelial cells was not due to extracellular matrix alteration but only to cellular activation or secretion of procoagulant substances. We conclude that human endothelial cells treated with endotoxin can trigger fibrin formation and deposition at their surface when exposed to flowing blood at low shear rate.

von Willebrand factor released from Weibel-Palade bodies binds more avidly to extracellular matrix than that secreted constitutively

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1531-1534 ◽  
Author(s):  
LA Sporn ◽  
VJ Marder ◽  
DD Wagner
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
Immunofluorescent Staining ◽  
Cultured Endothelial Cells ◽  
Human Foreskin Fibroblasts ◽  
Platelet Binding ◽  
The Matrix ◽  
Von Willebrand ◽  
Willebrand Factor

Large multimers of von Willebrand factor (vWf) are released from the Weibel-Palade bodies of cultured endothelial cells following treatment with a secretagogue (Sporn et al, Cell 46:185, 1986). These multimers were shown by immunofluorescent staining to bind more extensively to the extracellular matrix of human foreskin fibroblasts than constitutively secreted vWf, which is composed predominantly of dimeric molecules. Increased binding of A23187-released vWf was not due to another component present in the releasate, since releasate from which vWf was adsorbed, when added together with constitutively secreted vWf, did not promote binding. When iodinated plasma vWf was overlaid onto the fibroblasts, the large forms bound preferentially to the matrix. These results indicated that the enhanced binding of the vWf released from the Weibel-Palade bodies was likely due to its large multimeric size. It appears that multivalency is an important component of vWf interaction with the extracellular matrix, just as has been shown for vWf interaction with platelets. The pool of vWf contained within the Weibel-Palade bodies, therefore, is not only especially suited for platelet binding, but also for interaction with the extracellular matrix.

On the mechanism of thrombin-induced angiogenesis: involvement of αvβ3-integrin

2002 ◽  
Vol 283 (5) ◽  
pp. C1501-C1510 ◽  
Author(s):  
Nikos E. Tsopanoglou ◽  
Paraskevi Andriopoulou ◽  
Michael E. Maragoudakis
Keyword(s):  
Endothelial Cells ◽  
Vascular Tissue ◽  
Chorioallantoic Membrane ◽  
Membrane System ◽  
Angiogenic Factor ◽  
Αvβ3 Integrin ◽  
Cellular Effects ◽  
Chick Chorioallantoic Membrane

Thrombin has been reported to be a potent angiogenic factor both in vitro and in vivo, and many of the cellular effects of thrombin may contribute to activation of angiogenesis. In this report we show that thrombin-treatment of human endothelial cells increases mRNA and protein levels of αvβ3-integrin. This thrombin-mediated effect is specific, dose dependent, and requires the catalytic site of thrombin. In addition, thrombin interacts with αvβ3as demonstrated by direct binding of αvβ3protein to immobilized thrombin. This interaction of thrombin with αvβ3-integrin, which is an angiogenic marker in vascular tissue, is of functional significance. Immobilized thrombin promotes endothelial cells attachment, migration, and survival. Antibody to αvβ3or a specific peptide antagonist to αvβ3can abolish all these αvβ3-mediated effects. Furthermore, in the chick chorioallantoic membrane system, the antagonist peptide to αvβ3diminishes both basal and the thrombin-induced angiogenesis. These results support the pivotal role of thrombin in activation of endothelial cells and angiogenesis and may be related to the clinical observation of neovascularization within thrombi.

scholarly journals Synthesis of fibronectin by cultured human endothelial cells.

1978 ◽  
Vol 147 (6) ◽  
pp. 1779-1791 ◽  
Author(s):  
E A Jaffe ◽  
D F Mosher
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Human Plasma ◽  
Culture Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Basement Membranes ◽  
Plasma Fibronectin ◽  
Human Endothelial Cells ◽  
Cultured Endothelial Cells

Plasma fibronectin is probably the major nonimmune particulate opsonin in blood and is cross-linked to fibrin during the final stage of blood coagulation. Fibronectin also occurs in an insoluble form in basement membranes especially those underlying endothelial cells and in loose connective tissue. Fibronectin was demonstrated in cultured human endothelial cells and in the surrounding extracellular matrix by immunofluorescence microscopy by using antibody to human plasma fibronectin. Cultured human endothelial cells released fibronectin into the culture medium which was immunologically identical to the fibronectin in human plasma. Cultured human endothelial cells were labeled with [3H] leucine. The radioactive fibronectin present in the endothelial postculture medium and in urea extracts of cellular monolayers was isolated with either anti-fibronectin coupled to Protein A-Sepharose or double antibody immunoprecipitation and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. When reduced, the [3H] fibronectin synthesized by cultured endothelial cells had the same mol wt (approximately 200,000) as plasma fibronectin. Unreduced, the [3H] fibronectin synthesized by endothelial cells migrated as a dimer, as did plasma fibronectin. Fibronectin accounted for approximately 15% of the protein synthesized and released by endothelial cells into the culture medium. Thus, cultured endothelial cells synthesize fibronectin, secrete it into the culture medium, and incorporate it into extracellular matrix. The results suggest that the endothelial cell is potentially a major site of synthesis of circulating plasma fibronectin. In addition, fibronectin derived from endothelial cells may be an important structural component of the subendothelium.

scholarly journals Angiogenic and invasive properties of neurofibroma Schwann cells.

1990 ◽  
Vol 111 (2) ◽  
pp. 645-653 ◽  
Author(s):  
S Sheela ◽  
V M Riccardi ◽  
N Ratner
Keyword(s):  
Extracellular Matrix ◽  
Schwann Cells ◽  
Chorioallantoic Membrane ◽  
Model System ◽  
Basement Membranes ◽  
Benign Tumors ◽  
Epigenetic Changes ◽  
Normal Cells ◽  
Chick Chorioallantoic Membrane ◽  
Von Recklinghausen

Neurofibromas are benign tumors from patients with von Recklinghausen Neurofibromatosis (NF1) that are comprised primarily of Schwann cells. These Schwann cells are found both in association with axons and in the extracellular matrix that is prevalent in neurofibromas, and in which fibroblasts are also abundant. An unresolved question has been whether cells in neurofibromas are normal cells or are intrinsically abnormal. We have tested the hypothesis that cells in neurofibromas are abnormal and have shown that neurofibroma Schwann cells, unlike normal Schwann cells, promote angiogenesis in the chick chorioallantoic membrane model system, and invade basement membranes in this system. In contrast, neurofibroma fibroblasts neither promote angiogenic reactions nor invade basement membranes. When injected into nude mice, neurofibroma Schwann cells do not form progressive tumors. These results suggest that NF1 Schwann cells differ from normal Schwann cells, that they are preneoplastic, and that genetic and/or epigenetic changes in Schwann cells may be required for development of peripheral nerve tumors in NF1.

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