Urokinase production by embryonic endocardial-derived cells: regulation by substrate composition.
Early events in cardiovascular morphogenesis are characterized by cell migrations and extensive tissue remodeling. We are interested in the role played by the extracellular serine protease urokinase in these events. Elevated urokinase activity and mRNA levels have been shown to be associated with the onset of ventricular trabeculation and mesenchymal cell migration in the endocardial cushion tissues of the atrioventricular canal and the outflow tract of the quail embryo. In this study, urokinase production by isolated endocardial-derived cells was found to be affected by the composition of the matrix to which the cells were exposed. Interaction of cells with a 45-kDa gelatin-binding fragment of fibronectin upregulated the production of urokinase by nearly threefold. This increase in urokinase activity had profound influences on cell motility and spreading.
McGuire
P G
PG
Department of Anatomy, University of New Mexico School of Medicine, Albuquerque 87131.
Alexander
S M
SM
D000818:Animals; D002465:Cell Movement; D002478:Cells, Cultured; D046508:Culture Techniques; D004591:Electrophoresis, Polyacrylamide Gel; D004699:Endocardium / Q000166:cytology / Q000196:embryology / Q000201:enzymology*; D005353:Fibronectins / Q000378:metabolism; D011784:Quail; D013379:Substrate Specificity; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D005353:Fibronectins; D014568:Urokinase-Type Plasminogen Activator