Spatiotemporal segregation of endothelial cell integrin and nonintegrin extracellular matrix-binding proteins during adhesion events.

Abstract

Abstract. Bovine aortic endothelial cell (BAEC) attachments to laminin, fibronectin, and fibrinogen are inhibited by soluble arginine-glycine-aspartate (RGD)-containing peptides, and YGRGDSP activity is responsive to titration of either soluble peptide or matrix protein. To assess the presence of RGD-dependent receptors, immunoprecipitation and immunoblotting studies were conducted and demonstrated integrin/~1, /33, and associated t~ subunits as well as a/31 precursor. Immunofluorescence of BAECs plated on laminin, fibronectin, and fibrinogen reveals different matrixbinding specificities of each of these integrin subclasses. By 1 h after plating, organization of/~1 integrin into fibrillar streaks is influenced by laminin and fibronectin, whereas/~3 integrin punctate organization is influenced by fibrinogen and the integrin spatial distribution changes with time in culture. In contrast, the nonintegrin laminin-binding protein LB69 only organizes after cell-substrate contact is well established several hours after plating. Migration of BAECs is also mediated by both integrin and nonintegrin matrixbinding proteins. Specifically, BAEC migration on laminin is remarkably sensitive to RGD peptide inhibition, and, in its presence,/~1 integrin organization dissipates and reorganizes into perinuclear vesicles. However, RGD peptides do not alter LB69 linear organization during migration. Similarly, agents that block LB69-e.g., antibodies to LB69 as well as YIGSR-NH2 peptide-do not inhibit attachment of nonmotile BAECs to laminin. However, both anti-LB69 and YIGSR-NH2 inhibit late adhesive events such as spreading. Accordingly, we propose that integrin and nonintegrin extracellular matrix-binding protein organizations in BAECs are both temporally and spatially segregated during attachment processes. High affinity nonintegrin interaction with matrix may create necessary stable contacts for longterm attachment, while lower affinity integrins may be important for initial cell adhesion as well as for transient contacts of motile BAECs.

Melanoma Cell Invasive and Metastatic Potential Correlates with Endothelial Cell Reorganization and Tenascin Expression

“…These events appear to be dependent both on cell-cell and cell-matrix interactions. Previous studies have revealed that interaction of endothelial cells with components of extracellular matrix results in modulation of shape and behavior including cytoskeletal reorganization, cell spreading and migration (Madri et al 1988;Basson et al, 1990;Albelda et al, 1989;Lampugnani et al, 1991). Since significant differences in the monolayer behavior of endothelial cells on the different A375-derived cell lines were observed, we compared the expression of immobilized TN, FN and LN by the A375P, M and SM cell lines.…”

“…Changes in the extracellular matrix components of metastatic melanoma appear to correlate with alterations in the adhesion of endothelial cells to these matrices. The interaction of endothelial cells in vitro with components of the extracellular matrix such as laminin (LN), fibronectin (FN), collagen (Col) and proteoglycans (Madri et al, 1980) results in the modulation of shape and behavior of these cells (Madri et al, 1988) resulting in changes which include cytoskeletal reorganization, cell spreading and migration (Basson et al, 1990;Albelda et al, 1989;Lampugnani et al, 1991).…”

Migration of bovine aortic smooth muscle cells after wounding injury. The role of hyaluronan and RHAMM.

“…Although many of the mechanisms regulating endothelial cell migration have been defined, those that regulate smooth muscle cell migration are not as well understood. Growth factors such as TGF-f31 (33) and PDGF (34), protease-protease inhibitor cascades (35), extracellular matrix composition (36), cell surface adhesion molecules (37), and hormones (38) regulate endothelial locomotion. Although the same factors appear to regulate smooth muscle cell migration, most of the effects observed are opposite to those seen in endothelial cells (39).…”

Engineering of vascular ingrowth matrices: Are protein domains an alternative to peptides?

“…Within the various stages of migration, cell spreading has been shown to correlate more closely with the migration rate than cell attachment (Basson et al, 1990). While cell attachment is likely to be primarily integrin mediated, cell spreading appears to involve nonintegrin matrix-binding proteins as well (Basson et al, 1990). A heterogenous ligand-treated surface, for instance, containing both integrin-dependent adhesion systems and integrin-independent adhesion systems resulted in a significantly higher EC spreading than either of the two systems alone (Bhat et al, 1998).…”

“…However, the interplay between attachment and migration demonstrates once more how complex signalling is. Within the various stages of migration, cell spreading has been shown to correlate more closely with the migration rate than cell attachment (Basson et al, 1990). While cell attachment is likely to be primarily integrin mediated, cell spreading appears to involve nonintegrin matrix-binding proteins as well (Basson et al, 1990).…”