Angiostatin diminishes activation of the mitogen-activated protein kinases ERK-1 and ERK-2 in human dermal microvascular endothelial cells.
Angiostatin is an endogenous inhibitor of angiogenesis that was isolated from tumor-bearing mice. It has been established that angiostatin inhibits endothelial cell proliferation; however, the underlying mechanisms remain to be elucidated. Here we report that angiostatin reduces transiently the phosphorylation of the mitogen-activated protein kinases ERK-1 and ERK-2 in human dermal microvascular cells, but not in human vascular smooth muscle cells or human dermal fibroblasts. We demonstrate that angiostatin diminishes ERK activation by basic fibroblast growth factor and vascular endothelial growth factor. Dephosphorylation of ERK and other tyrosine-phosphorylated proteins was blocked by pretreatment of the cells with sodium meta-vanadate, an inhibitor of protein tyrosine phosphatases, indicating that angiostatin signaling may require the activity of a tyrosine phosphatase. Concentrations of angiostatin that inhibited ERK activation also inhibited basic fibroblast growth factor-stimulated collagen gel invasion by endothelial cells, but did not affect endothelial cell proliferation. We thus show that angiostatin inhibits primarily the invasion of endothelial cells and exerts minimal (if any) effects on their proliferation. Invasion is a process that involves proteolysis, adhesion and migration, all of which have been linked to ERK signaling.
Departments of Biological Structure and Surgery, University of Washington, Seattle, Wash., USA.
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Redlitz
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Daum
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Sage
D043168:Angiostatins; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D008222:Lymphokines / Q000494:pharmacology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D018919:Neovascularization, Physiologic; D010446:Peptide Fragments / Q000494:pharmacology*; D010766:Phosphorylation; D010958:Plasminogen / Q000494:pharmacology*; D012867:Skin / Q000098:blood supply*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D010446:Peptide Fragments; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2; D043168:Angiostatins; D010958:Plasminogen; D003094:Collagen; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases