Von Willebrand factor promotes endothelial cell adhesion via an Arg-Gly-Asp-dependent mechanism.

Abstract

Abstract, Von Willebrand factor (vWF) is a constitutive and specific component of endothelial cell (EC) matrix. In this paper we show that, in vitro, vWF can induce EC adhesion and promote organization of microfilaments and adhesion plaques. In contrast, human vascular smooth muscle cells and MG63 osteosarcoma cells did not adhere and spread on vWE Using antibodies to the/3 chains of fibronectin (~) and vitronectin (~3) receptors it was found that ECs adherent to vWF show clustering of both receptors. The/3, receptor antibodies are arranged along stress fibers at sites of extraceUular matrix contact while the /33 receptor antibodies were sharply confined at adhesion plaques. ECs release and organize endogenous fibronectin early during adhesion to vWE Upon blocking protein synthesis and secretion, ECs can equally adhere and spread on vWF but, while the ~3 receptors are regularly organized, the ~, receptors remain diffuse. This suggests that the organization of the/31 receptors depend on the release of fibronectin and/or other matrix proteins operated by the same cell. Antibodies to the ~3 receptors fully block EC adhesion to vWF and detach ECs seeded on this substratum. In contrast, antibodies to the ~ receptors are poorly active. Overall these results fit with an accessory role of ~ receptors and indicate a leading role for the ~3 receptors in EC interaction with vWF. To identify the EC binding domain on vWF we used monoclonal antibodies produced against a peptide representing the residues Glu1737-Ser175° of the mature vWF and thought to be important in mediating its binding to the platelet receptor glycoprotein IIb-IIIa. We found that the antibody that recognizes the residues 1,744-1,746, containing the Arg-Gly-Asp sequence, completely inhibit EC adhesion to vWF whereas a second antibody recognizing the adjacent residues 1,740-1,742 (Arg-GlyAsp-free) is inactive. Both antibodies do not interfere with EC adhesion to vitronectin. This defines the molecular domain on vWF that is specifically recognized by ECs and reaffirms the direct role of the Arg-GlyAsp sequence as the integrin receptor recognition site also in the vWF molecule.

β1‐integrin‐mediated adhesion of melanoma cells to the propolypeptide of von Willebrand factor

“…It is well known that the mature vWF promotes the adhesion of endothelial cells in an RGD-dependent fashion [7]. As clearly shown in Fig.…”

“…Although these three proteins are abundant in ECM and thought to be primarily important in tissue organization under physiological conditions, there are a number of other proteins that have cell-adhesion activity in vitro and are thought to play a crucial role in more specialized stages of cellular events. [7]. A large amount of evidence is accumulating that these adhesive glycoproteins play dynamic roles in embryo-…”

Notch promotes vascular maturation by inducing integrin-mediated smooth muscle cell adhesion to the endothelial basement membrane

“…Importantly, VWF is an RGD-containing adhesion protein that is unique to the vascular basement membrane. 34,35 Previous studies have revealed that endothelial cells and VSMCs share a common basement membrane in mature arteries. 36,37 Because endothelial cells and VSMCs both up-regulate integrin ␣␤3, a receptor for their shared basement membrane, during angiogenesis, we considered whether VWF might regulate VSMC-dependent arterial maturation.…”

Decreased adhesion to endothelial cells and matrix proteins of H-2Kb gene transfected tumour cells

“…In the present study, H-2-negative B78H1 and four control clones were compared to five H-2Kb transfectants, one of which (Kb-G56) showed a poor, even though interferoninducible, (Dejana et al, 1987), were routinely characterised by immunofluorescence techniques using rabbit anti-human factor VIII antigen (Behringwerke, AG, Marburg, Germany) (Balconi & Dejana, 1986;Dejana et al, 1989). The cells were cultured in medium 199 (M 199) supplemented with 20% FCS, 50 jig ml-' endothelial cell growth supplement (prepaed from bovine brain), 100 tg ml-' heparin (Sigma Chemical Co., St. Louis, MO, USA), 50 U ml-1 penicillin, 50 tg ml-' streptomycin, 2.5 tLg ml-' fungizone at 37°C.…”