FGF-2 and VEGF are potent angiogenesis inducers in vivo vitro. Here we show that induces expression vascular endothelial cells through autocrine paracrine mechanisms. Addition of recombinant to cultured or upregulation endogenous results increased expression. Neutralizing monoclonal antibody inhibits FGF-2–induced cell proliferation. Endogenous 18-kD production upregulates extracellular interaction with membrane receptors; high-Mr (22–24-kD) acts via intracellular mechanism(s). During...

Basic fibroblast growth factor (bFGF) modulates functions of a variety cell types. Whereas bFGF is known to act extracellularly, the protein lacks transient signal peptide. No defined mechanism for secretion has been characterized besides release from dead or injured cells. To study this problem we devised an experimental system examine bFGF-mediated migration isolated single Under these conditions individual cells are not affected by derived other By method have previously shown that...

The role of basic fibroblast growth factor-(bFGF) induced proteinases in basement membrane (BM) invasion by bovine capillary endothelial (BCE) cells was studied using a quantitative vitro assay previously described (Mignatti et al., 1986). 125I-iododeoxyuridine-labeled BCE were grown for 72 h on the human amnion BM, and cell determined measuring radioactivity associated with tissue after removal noninvasive layer. under normal conditions. Addition bFGF to either BM or stromal aspect...

Abstract VEGF and TGF‐β1 induce angiogenesis but have opposing effects on endothelial cells. protects cells from apoptosis; induces apoptosis. We previously shown that VEGF/VEGF receptor‐2 (VEGFR2) signaling mediates induction of This finding raised an important question: Does this mechanism stimulate or inhibit angiogenesis? Here we report VEGF‐mediated apoptosis is required for angiogenesis. In vitro the apoptotic effect rapid followed by a long period in which are refractory to TGF‐β1....

Abstract Gelatinase A (MMP‐2), a matrix metalloproteinase (MMP) involved in tumor invasion and angiogenesis, is secreted as an inactive zymogen (proMMP‐2) activated by proteolytic cleavage. Here we report that polymorphonuclear neutrophil (PMN)‐derived elastase, cathepsin G, proteinase‐3 activate proMMP‐2 through mechanism requires membrane‐type 1 (MT1‐MMP) expression. Immunoprecipitation of human PMN‐conditioned medium with mixture antibodies to abolished activation, whereas individual were...

Vascular endothelial growth factor (VEGF) is a potent angiogenic and cell-specific mitogen that stimulates urokinase-type plasminogen activator (uPA) activity in vascular cells. Here, we report VEGF increases the high affinity binding of uPA to same cells this prevented by peptide corresponding receptor (uPAR) factor-like domain uPA. Ligand cross-linking, ligand blotting, uPA-Sepharose chromatography revealed an increase cell surface protein corresponds uPAR on basis its for uPA, Mrof...

Basic fibroblast growth factor (bFGF), a protein with angiogenic, mitogenic, and chemotactic properties, lacks signal sequence is not secreted via the classical secretory pathway. However, known to act extracellularly. Since no defined mechanism for bFGF release has been described, it suggested that this released from dead or damaged cells. To test hypothesis we characterized effect of exogenously added neutralizing antibody on migration single, isolated NIH 3T3 cells transfected cDNA. Under...

To study possible functional differences of the 18-kD and high molecular weight forms basic fibroblast growth factor (bFGF), we have examined effect endogenous production different bFGF on phenotype NIH 3T3 cells. Cells transfected with cDNAs coding for either (18-kD bFGF) or all four (18, 22, 22.5, 24 kD; wild type [WT] exhibit increased migration decreased FGF receptor number compared to parental However, cells a cDNA only (22, HMW were similar that vector alone. expressing HMW, 18 kD, WT...

Exposure of bovine aortic or capillary endothelial cells to basic FGF (bFGF) for 1 h resulted in an approximately sixfold increase plasminogen activator (PA) activity by 18 that returned nearly basal levels 36 h. We hypothesized the decrease PA following bFGF stimulation was mediated transforming growth factor beta (TGF-beta) formed from its inactive precursor. Conditioned medium collected after a 1-h exposure bFGF, but not control medium, inhibited when transferred confluent monolayers...

Basic fibroblast growth factor, a potent angiogenesis inducer, stimulates urokinase (uPA) production by vascular endothelial cells. In both basic factor-stimulated and -nonstimulated bovine capillary human umbilical vein cells single-chain uPA binding is mediated membrane protein with Mr of 42,000. Exposure or to pmolar concentrations factor results in dose-dependent, synthesis-dependent increase the number receptors for (19,500-187,000) parallel decrease their affinity (KD = 0.144-0.790...

Membrane vesicles are shed by tumor cells both in vivo and vitro. Although their functions not well understood, it has been proposed that they may play multiple roles progression. We characterized membrane from human HT1080 fibrosarcoma cell cultures for the presence of proteinases involved invasion. By gelatin zymography Western blotting, these showed major bands corresponding to zymogen active forms gelatinase B (MMP-9) A (MMP-2) MMP-9. tissue inhibitor metalloproteinase 1 complex. Both...

von Willebrand factor (vWF), a glycoprotein produced uniquely by endothelial cells and megakaryocytes, is routinely used to identify vessels in tissue sections. Vessel density tumor specimens, as determined immuno-histochemical staining for vWF or other cell markers, negative prognostic many solid tumors. heterogeneously distributed throughout the vasculature, transcriptional control response microenvironment being responsible local variations levels of vWF. Here, we report that fibroblast...

Abstract Membrane‐type 1 matrix metalloproteinase (MT1‐MMP) has been implicated as a physiological activator of progelatinase A (MMP‐2). We previously reported that plasmin treatment cells results in proMMP‐2 activation and increased type IV collagen degradation. Here, we analyzed the role MT1‐MMP MMP‐2 using HT‐1080 transfected with sense or antisense cDNA. Control, vector‐transfected expressed endogenous MT1‐MMP, cDNA transfectants very low levels did not activate proMMP‐2. Conversely,...

VEGF and TGF-beta1 are potent angiogenesis inducers with opposing effects on endothelial cells. induces apoptosis; protects cells from apoptosis. We found that promotes cell expression of FGF-2, which up-regulates synthesis. Inhibition signaling through receptor 2 (flk-1) abrogates TGF-beta1-induced apoptosis p38(MAPK) activation. blocks apoptosis, showing VEGF/flk-1-mediated activation is required for induction In the absence TGF-beta1, activates survival. However, in context results Thus,...

Abstract Recently, a novel class of angiostatic steroids which block angiogenesis in several systems has been described. Since the elaboration proteases is believed to be an important component angiogenesis, we tested whether these blocked fibrinolytic response endothelial cells angiogenic protein, basic fibroblast growth factor [bFGF]). Cultured bovine aortic (BAE) were incubated with bFGF and/or medroxyprogesterone acetate (MPA), angio‐static steroid shown inhibit vascularization,...

Membrane-type 1 matrix metalloproteinase (MT1-MMP), a transmembrane proteinase with short cytoplasmic domain and an extracellular catalytic domain, controls variety of physiological pathological processes through the proteolytic degradation or proteins. MT1-MMP forms complex on cell membrane its protein inhibitor, tissue inhibitor metalloproteinases-2 (TIMP-2). Here we show that, in addition to proteolysis, TIMP-2 control proliferation migration non-proteolytic mechanism. binding induces...

We investigated the role of periostin, an extracellular matrix protein, in pathophysiology osteoarthritis (OA). In OA, dysregulated gene expression and phenotypic changes articular chondrocytes culminate progressive loss cartilage from joint surface. The molecular mechanisms underlying this process are poorly understood. examined periostin by immunohistochemical analysis lesional nonlesional human rodent OA knee cartilage. addition, we used small interfering (si) RNA adenovirus transduction...

von Willebrand factor (vWF), a glycoprotein produced uniquely by endothelial cells and megakaryocytes, is routinely used to identify vessels in tissue sections. Vessel density tumor specimens, as determined immuno-histochemical staining for vWF or other cell markers, negative prognostic many solid tumors. heterogeneously distributed throughout the vasculature, transcriptional control response microenvironment being responsible local variations levels of vWF. Here, we report that fibroblast...