High-affinity augmentation of endothelial cell attachment: long-term effects on focal contact and actin filament formation.
Coadsorption of high-affinity avidin with lower affinity cell adhesion protein fibronectin has been shown to significantly augment short-term (1 h) adhesion and spreading of endothelial cells; however, the longer term persistence of avidin binding and its effect on endothelial cell adhesion have not been addressed. In this study, the presence of avidin-biotin bonds 24 h after cell adhesion to the dual ligand surfaces was verified by laser confocal microscopy of a fluorescent avidin analog, streptavidin. Total internal reflection microscopy showed that the focal contact area, focal contact density, and cell spreading all increased significantly at 24 h compared to fibronectin-treated control surfaces. Focal contact area was identical when measured with cells that were labeled with either the fluorescent streptavidin or a carbocyanine dye incorporated in the cell membrane. Confocal images of stress fibers formed in cells adherent to dual ligand surfaces after 24 h were thicker and more numerous compared to cells adherent to fibronectin controls. The results indicate that 24 h after initial attachment avidin-biotin is localized to focal contacts on the basal surface and affects cell spreading, actin filament organization, and focal contact density.
Mathur
Anshu B
AB
Center for Cellular and Biosurface Engineering and Department of Biomedical Engineering, Duke University, Box 90281, Durham, NC 27708-0281, USA.
Chan
Bernard P
BP
Truskey
George A
GA
Reichert
William M
WM
D000199:Actins / Q000378:metabolism*; D002448:Cell Adhesion; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology*; D006801:Humans; D008024:Ligands; D018613:Microscopy, Confocal; D012710:Serum Albumin, Bovine / Q000378:metabolism; D019809:Streptavidin / Q000378:metabolism
D000199:Actins; D008024:Ligands; D012710:Serum Albumin, Bovine; D019809:Streptavidin