Regulation of motility in bovine brain endothelial cells.
Scatter factor (SF) is a fibroblast-derived cytokine which stimulates motility of epithelial and vascular endothelial cells. We used a quantitative assay based on migration of cells from microcarrier beads to flat surfaces to study the regulation of motility in bovine brain endothelial cells (BBEC). Peptide growth factors (EGF, ECGF, basic FGF) did not stimulate migration. Tumor promoting phorbol esters (PMA, PDD) markedly stimulated migration, while inactive phorbol esters (4a-PDD, phorbol-13,20-diacetate) did not affect migration. Both SF- and PMA-stimulated migration were inhibited by 1) TGF-beta; 2) protein kinase inhibitors (e.g., staurosporine, K-252a); 3) activators of the adenylate cyclase signaling pathway (e.g., dibutyryl cyclic AMP, theophylline); 4) cycloheximide; and 5) anti-cytoskeleton agents (e.g., cytochalasin B, colcemid). However, PMA and SF pathways were distinguishable: 1) PMA induced additional migration at saturating SF concentrations; 2) the onset of migration-stimulation was immediate for PMA and delayed for SF; and 3) down-modulation of protein kinase C (PKC) ablated PMA but not SF responsiveness. Assessment of PKC by (3H)-phorbol ester (PDBu) binding and by immunoblot showed 1) scatter factor does not cause significant redistribution or down-modulation of PDBu binding or alpha-PKC; and 2) PDBu mediates redistribution and down-modulation of both binding and alpha-PKC. These findings suggest two pathways for BBEC motility: a PKC-dependent pathway and an SF-stimulated/PKC-independent pathway.
Rosen
E M
EM
Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06510.
Jaken
S
S
Carley
W
W
Luckett
P M
PM
Setter
E
E
Bhargava
M
M
Goldberg
I D
ID
D000818:Animals; D001921:Brain / Q000098:blood supply*; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D003599:Cytoskeleton / Q000187:drug effects; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006133:Growth Substances / Q000502:physiology; D017228:Hepatocyte Growth Factor; D066298:In Vitro Techniques; D009712:Nucleotides, Cyclic / Q000502:physiology; D010703:Phorbol Esters / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011506:Proteins / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D013997:Time Factors
D006133:Growth Substances; D009712:Nucleotides, Cyclic; D010703:Phorbol Esters; D047428:Protein Kinase Inhibitors; D011506:Proteins; D017228:Hepatocyte Growth Factor