Abstract
We have previously reported that tissue inhibitor of metalloproteinases-2 (TIMP-2), an endogenous inhibitor of matrix metalloproteinase, modulates angiogenic responses through the MMP inhibition-independent activity. In this study, we investigate the molecular mechanisms of TIMP-2-mediated growth inhibition in response to fibroblast growth factor-2 (FGF-2). Pre-treatment with a protein tyrosine phosphatase inhibitor orthovanadate or expression of a dominant negative Shp-1 mutant fails to induce TIMP-2 inactivation of FGF-2 signaling pathways in human microvascular endothelial cells. We also show that TIMP-2 inhibition of FGF-2-induced p42/44(MAPK) activation and cell proliferation is associated with TIMP-2 binding to integrin alpha3beta1 on endothelial cell surfaces, as demonstrated by use of anti-integrin alpha3 or beta1 blocking antibodies, or disruption of integrin alpha3 expression by siRNA. Collectively, our results indicate that TIMP-2 inhibits FGF-2 signaling pathways through association with integrin alpha3beta1 and Shp-1-dependent inhibition of p42/44(MAPK) signaling, which in turn, results in suppression of FGF-2-stimulated endothelial cell mitogenesis.
Publication types
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Research Support, N.I.H., Intramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Base Sequence
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Cell Line, Tumor
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Cell Proliferation / drug effects
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Cells, Cultured
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Endothelial Cells / cytology
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Endothelial Cells / drug effects*
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Endothelial Cells / physiology
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Fibroblast Growth Factor 2 / pharmacology*
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Fibroblast Growth Factor 2 / physiology
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Humans
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Integrin alpha3beta1 / antagonists & inhibitors
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Integrin alpha3beta1 / genetics
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Integrin alpha3beta1 / physiology
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MAP Kinase Signaling System / drug effects
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MAP Kinase Signaling System / physiology
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Matrix Metalloproteinases / physiology
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Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 1 / metabolism
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Mitogen-Activated Protein Kinase 3 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 3 / metabolism
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Neovascularization, Physiologic
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Protein Tyrosine Phosphatase, Non-Receptor Type 6 / physiology
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RNA, Small Interfering / genetics
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Receptor, Fibroblast Growth Factor, Type 1 / physiology
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Recombinant Proteins / pharmacology
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Signal Transduction / drug effects*
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Signal Transduction / physiology
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Tissue Inhibitor of Metalloproteinase-2 / pharmacology*
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Tissue Inhibitor of Metalloproteinase-2 / physiology
Substances
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Integrin alpha3beta1
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RNA, Small Interfering
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Recombinant Proteins
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Fibroblast Growth Factor 2
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Tissue Inhibitor of Metalloproteinase-2
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FGFR1 protein, human
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Receptor, Fibroblast Growth Factor, Type 1
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3
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PTPN6 protein, human
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Matrix Metalloproteinases