Showing papers on "Vascular endothelial growth factor A published in 1990"

Vascular permeability factor: a tumor-derived polypeptide that induces endothelial cell and monocyte procoagulant activity, and promotes monocyte migration.

Abstract: Systemic infusion of low concentrations of tumor necrosis factor/cachectin (TNF) into mice that bear TNF-sensitive tumors leads to activation of coagulation, fibrin formation, and occlusive thrombosis exclusively within the tumor vascular bed. To identify mechanisms underlying the localization of this vascular procoagulant response, a tumor-derived polypeptide has been purified to homogeneity from supernatants of murine methylcholanthrene A-induced fibrosarcomas that induces endothelial tissue factor synthesis and expression (half-maximal response at approximately 300 pM), and augments the procoagulant response to TNF in a synergistic fashion. This tumor-derived polypeptide was identified as the murine homologue of vascular permeability factor (VPF) based on similar mobility on SDS-PAGE, an homologous NH2-terminal amino acid sequence, and recognition by a monospecific antibody to guinea pig VPF. In addition, VPF was shown to induce monocyte activation, as evidenced by expression of tissue factor. Finally, VPF was shown to induce monocyte chemotaxis across collagen membranes and endothelial cell monolayers. Taken together, these results indicate that VPF can modulate the coagulant properties of endothelium and monocytes, and can promote monocyte migration into the tumor bed. This suggests one mechanism through which tumor-derived mediators can alter properties of the vessel wall.

Production of vascular endothelial cell growth factor

Abstract: There is described an isolated vascular endothelial cell growth factor selected from the group consisting of bovine vascular endothelial cell growth factor of 120 amino acids and human vascular endothelial cell growth factor of 121 amino acids. The vascular endothelial cell growth factor is useful in the treatment of wounds in which neovascularization or reendothelialization is required for healing.

Amino acid and cDNA sequences of a vascular endothelial cell mitogen that is homologous to platelet-derived growth factor.

Abstract: Glioma-derived vascular endothelial cell growth factor (GD-VEGF) is a 46-kDa dimeric glycoprotein mitogen with apparently greater specificity for vascular endothelial cells than the well-characterized fibroblast growth factors. The GD-VEGF cDNA sequence encodes a 190-amino acid residue subunit that is converted, by removal of an amino-terminal hydrophobic secretory leader sequence, to the mature 164-residue subunit characterized by direct amino acid sequencing. The GD-VEGF homodimeric subunit is homologous to the platelet-derived growth factor A and B chains and its oncogene homologue v-sis.

Vascular endothelial growth factor is expressed in rat corpus luteum

Abstract: In the course of the development of the ovarian follicle and differentiation of granulosa cells into corpus luteum (CL), extensive changes in the microvasculature of these structures take place. This suggests the local release of angiogenic factors. In the present work we examined whether a newly described secreted vascular endothelial growth factor (VEGF) is expressed in normal rat ovary by in situ hybridization. Our results demonstrate the expression of VEGF in the CL but not in mural granulosa cells, suggesting a temporal relation between VEGF expression and growth of capillary vessels. The hybridization pattern in the CL was consistent with localization of VEGF message to luteal cells. Expression of VEGF was detected also in cumulus oophorus cells. These findings suggest that VEGF is involved in the process of CL angiogenesis.

Purification of a glycoprotein vascular endothelial cell mitogen from a rat glioma-derived cell line.

Abstract: A growth factor that is mitogenic for vascular endothelial cells, with an ED50 of approximately 1 ng/ml, has been purified 170,000-fold to apparent homogeneity from tissue culture medium conditioned by a rat glioma-derived cell line The pure protein is a 46-kDa dimer composed of two subunits of equivalent mass as established by comparison of migration in SDS/polyacrylamide gels with and without prior reduction This glioma-derived growth factor is a glycoprotein and is not mitogenic for BALB/c 3T3 fibroblasts, properties that further distinguish it from other well-characterized vascular endothelial cell mitogens In contrast to acidic and basic fibroblast growth factors and to platelet-derived endothelial cell growth factor, which have no secretory leader sequences and might only be released by leakage from damaged cells, the glycoprotein nature of this mitogen implies that it is processed through the glycosylating secretory pathway This secretable growth factor could, therefore, be readily available in the extracellular space under normal physiological conditions in vivo to promote vascular endothelial cell proliferation associated with blood-vessel growth and maintenance

Interleukin 1 is an autocrine regulator of human endothelial cell growth.

Abstract: Proliferation of endothelial cells is regulated through the autocrine production of growth factors and the expression of cognate surface receptors. In this study, we demonstrate that interleukin 1 (IL-1) is an inhibitor of endothelial growth in vitro and in vivo. IL-1 arrested growing, cultured endothelial cells in G1 phase; inhibition of proliferation was dose dependent and occurred in parallel with occupancy of endothelial surface IL-1 receptors. In an angiogenesis model, IL-1 could inhibit fibroblast growth factor-induced vessel formation. The autocrine nature of the IL-1 effect on endothelial proliferation was demonstrated by the observation that occupancy of cell-surface receptors by endogenous IL-1 depressed cell growth. The potential significance of this finding was emphasized by the detection of IL-1 in the native endothelium of human umbilical veins. A mechanism by which IL-1 may exert its inhibitory effect on endothelial cell growth was suggested by studies showing that IL-1 decreased the expression of high-affinity fibroblast growth factor binding sites on endothelium. These results point to a potentially important role of IL-1 in regulating blood vessel growth and suggest that autocrine production of inhibitory factors may be a mechanism controlling proliferation of normal cells.

DNA sequences encoding bVEGF120 and hVEGF121 and methods for the production of bovine and human vascular endothelial cell growth factors, bVEGF120 and hVEGF121

Abstract: Isolated DNA sequences, expression vectors and transformant cells are provided which allow for the large scale production of vascular endothelial cell growth factor. The vascular endothelial cell growth factor is useful in the treatment of wounds in which neovascularization or reendothelialization is required for healing.

Conditioned Medium from Mouse Sarcoma 180 Cells Contains Vascular Endothelial Growth Factor

Abstract: Medium conditioned by mouse sarcoma 180 cells stimulates the growth of capillary endothelial cells. The growth factor produced by mouse sarcoma 180 cells is heparin-binding, dithiothreitol-sensitive, endothelial cell specific, and secreted into the medium. The characteristics of this mouse sarcoma-derived growth factor are very similar to those of vascular endothelial growth factor (VEGF) first described by Ferrara and Henzel (1989). The N-terminal amino acid sequences of the two growth factors are similar. Since the amino acid sequence of vascular permeability factor (VPF) is essentially identical to that of VEGF, a Western blot of mouse sarcoma 180-derived endothelial growth factor was probed with a polyclonal antibody raised against human VPF. This antibody reacted with several proteins of approximately 23 kDa, suggesting the presence of multiple forms of a VEGF-like protein. A full length cDNA probe for bovine VEGF reacted strongly with RNA isolated from mouse sarcoma 180 cells. We conclude that an endothelial growth factor found in conditioned medium from mouse sarcoma 180 cells is VEGF.

Purified scatter factor stimulates epithelial and vascular endothelial cell migration.

Abstract: Fibroblasts and smooth muscle cells release a protein activity which causes epithelial sheets to "scatter" into isolated cells. Purification of scatter factor (SF) activity from ras-transformed 3T3 cells was reported recently. We purified ras-3T3 SF by a slightly different method with essentially similar findings. Purified factor showed a single band at 77 +/- 3 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions. Scatter activity was eluted from gel slices at this molecular size. Reduction with mercaptoethanol caused the loss of activity and the appearance of two bands (58 and 31 kDa). We report the amino acid composition of ras-3T3 SF and sequences of several tryptic peptides. These sequences were not similar to the known proteins in the Protein Database. We have shown previously that partially purified ras-3T3 scatter activity stimulates migration of epithelial and vascular endothelial cells in a new migration assay utilizing microcarrier beads. We now demonstrate that the same purified ras-3T3 protein scatters epithelial cells and stimulates epithelial and endothelial migration in microcarrier bead and Boyden chamber assays. Partially purified human smooth muscle scatter activity shares these activities, but the protein(s) responsible has not been isolated. Migration-stimulating activity was maximal at ras-3T3 protein concentrations less than 10 ng/ml (0.13 nM). ras-3T3 SF had no collagenolytic activity and did not stimulate DNA synthesis in fibroblast growth factor-responsive human melanocytes. ras-3T3 SF appears to be a new protein which regulates endothelial and epithelial mobility; and, therefore, it may be involved in vascular repair and wound healing.

The control of vascular endothelial cell injury.

Abstract: The mechanism by which MCI-186 showed a potent cytoprotective effect on the in vitro endothelial cell injury due to 15-HPETE was studied Stimulation of human leukocytes with various chemical mediators such as TPA, f-Met-Leu-Phe, LTB4, etc elicited the production of active oxygens, which could be detected by luminol-dependent chemiluminescence Among the chemical mediators tested, TPA elicited the chemiluminescence the most, and f-Met-Leu-Phe and LTB4 came next When the leukocytes were directly placed on a monolayer of cultured endothelial cells, followed by stimulating the leukocytes with TPA, severe endothelial cell injury was observed The effect of TPA was dose dependent There was good correlation between the active oxygen releasing activity and the cytotoxic activity When the leukocytes were placed on a filter which was set apart from the monolayer of endothelial cell in a culture dish, and stimulated the leukocytes with TPA, no cytotoxicity was observed These data strongly suggest that the substance responsible for the cytotoxicity must be a very labile and short-lived substance, presumably active oxygens On the other hand, MCI-186 was found to have a complete quenching activity to the chemiluminescence due to active oxygens in the TPA-leukocyte system Taken together, these factors indicate that the potent cytoprotective effect of MCI-186 may be due to its specific radical scavenging activity

Modulation of Endothelial Hemostatic Properties: An Active Role in the Host Response

Abstract: As the cells forming the luminal vascular surface, endothelium regulates both barrier function, and pro- and anticoagulant reactions. Endothelial cells can do this by controlling the expression of cell surface molecules, such as receptors that regulate the hemostatic balance and those that affect permeability across the endothelial monolayer. This regulation occurs in response to environmental stimuli, such as cytokines, which have a central role in inflammation, or glucose-modified proteins, which accumulate in the vasculature in aging and diabetes and are associated with vascular complications. The endothelial cell emerges as a dynamic regulator maintaining homeostasis in the quiescent state and contributing to the pathogenesis of vascular lesions in the stimulated state.

The role of platelet-activating factor in endothelial cells.

Abstract: Endothelial cells activated by receptor-mediated agonists, particularly those involved in inflammation and thrombosis, synthesize platelet-activating factor and express it on their surfaces. This PAF serves as a signal for neutrophils, and perhaps other blood cells, to bind to the endothelium. In some cases, the PAF produced by endothelial cells appears to be a sufficient stimulus for this binding, but in other circumstances it appears to act in concert with a glycoprotein, GMP-140. The synthesis and expression of PAF are tightly regulated under normal conditions, but can be induced by bacterial toxins and oxidants, which in vivo might result in vascular damage and thrombosis.

Activation of protein kinase C is crucial in the regulation of ICAM-1 expression on endothelial cells by interferon-γ

Abstract: ICAM-1 (CD54) is expressed on endothelial cells and serves as an important ligand for the white cell adhesion molecule CD11a/CD18 (LFA-1). Many studies have demonstrated that increased numbers of white cells binding to endothelial cells correlate with the level of ICAM-1 expression on endothelial cells. Several cytokines, including IFN-gamma, increase ICAM-1 expression in cultured human endothelial cells. We have analysed the second intracellular messenger pathways involved in IFN-gamma-induced up-regulation of ICAM-1 expression in endothelial cells. IFN-gamma induced a rapid activation of phospholipase C, leading to a breakdown of phosphoinositoldiphosphate (PIP2) into diacyglycerol (DAG) and inositoltriphosphate (IP3). DAG is a natural activator of the protein kinase C pathway. We were able to show that the effect induced by IFN-gamma could be inhibited by a protein kinase C inhibitor, H7, in a dose-dependent manner and mimicked by PMA, which stimulates protein kinase C. IFN-gamma induced a 5-fold translocation (activation) of protein kinase C from the cytosol into the endothelial cell membrane. Elevation of the IP3 levels led to activation of the calcium-dependent pathway. An inhibitor of calcium calmodulin, W7, decreased the IFN-gamma induced ICAM-1 expression, and addition of calcium ionophore to endothelial cells could replace IFN-gamma in the up-regulation of ICAM-1. Finally, IFN-gamma caused a significant increase in the calcium flux of endothelial cells. cAMP and cGMP had no effect on the regulation of ICAM-1 expression on cultured human endothelial cells.

Intrinsic Bioactivity of Insulin-Like Growth Factor-Binding Proteins from Vascular Endothelial Cells*

Abstract: Conditioned medium from cultured vascular endothelial cells contains material capable of stimulating acute metabolic processes in endothelial cells. The bioactivity of the conditioned medium is not caused by the copurification of known growth factors produced by the cells, in particular platelet-derived growth factor, basic fibroblast growth factor, or insulin-like growth factor (IGF)-I/II. We now demonstrate that the bioactivity is directly due to an IGF-binding protein(s) (ECBP) and, further, that the bioactive domain of the binding protein differs from the IGF-binding domain. Binding proteins (BPs) from cultured pulmonary artery endothelial cells were purified by sequential passage over sizing, multiplication-stimulating activity affinity, and hydrophobic columns. BP fractions were separated into those with and those without biological activity. The bioactive binding protein(s) was cross-linked with disuccinimidyl suberate to IGF-I or the recombinant IGF analog [1-27,Gly4,38-70]IGF-I (Analog). The IGF-I Analog, by itself, had minimal interaction with the type I IGF receptor in cultured microvessel endothelial cells and no intrinsic bioactivity, but did bind with high affinity to ECBP. All free BP and free IGF-I/Analog were removed from the cross-linked mixture by passage over gel filtration and IGF affinity columns. The cross-linked BP-IGF-I complex did not bind to the type I receptor of cultured endothelial cells, but did stimulate glucose and alpha-aminoisobutyric acid uptake in endothelial cells (approximately 2-fold increase); the magnitude of the response was nearly equal to the effect of ECBP or IGF-I alone. The BP-Analog complex also stimulated glucose and alpha-aminoisobutyric acid uptake, with the magnitude of the response approaching the effect of ECBP alone. The BP-Analog complex also did not react with type I IGF receptors on the cultured endothelial cells. We conclude 1) IGF-BP produced by endothelial cells possess intrinsic biological activity; 2) bioactivity of the BP(s) is retained when the IGF-binding domain of the BP is occupied by IGF-I or an inactive IGF-I analog; and 3) IGF-I bound to the bioactive BP does not react with its receptor and possesses minimal, if any, bioactivity in vitro.

Endothelial Control of Vascular Tone and Growth

Abstract: Endothelial cells play an important regulatory role in the circulation as a physical barrier and as a source of a variety of regulatory substances. Endothelium-derived nitric oxide and prostacyclin are released in response to physical stimuli, hormones and platelet-derived substances and induce vascular relaxation and inhibition of platelet function. Certain substances can evoke a hyperpolarization of smooth muscle cells. In addition, endothelial cells can release several contracting factors (i.e. endothelin, thromboxane A2, angiotensin II, superoxide and unidentified endothelium-derived contracting factors), at least under certain conditions. Endothelial cells are also a source of growth inhibitors and promoters, such as heparin and heparin sulphates, platelet-derived growth factor and thrombospondin. Several vasoactive substances produced by the endothelium, such as nitric oxide, endothelin and angiotensin II may also play a role in the regulation of vascular growth. Thus, the endothelial layer can regu...

Heparin-endothelial cell interactions.

Abstract: Recent observations have revealed that heparin influences endothelial cell proliferation in a number of ways unrelated to its anticoagulant properties. A majority of the nonanticoagulant actions of he

cAMP mediates IL-1-induced lymphocyte penetration through endothelial monolayers.

Abstract: Endothelial cell incubated with IL-1 have been shown adhere more lymphocytes than nontreated endothelial cells. Here we demonstrate that IL-1 can also increase lymphocyte penetration through endothelial monolayers in vitro. IL-1 induced a transient increase in the number of lymphocytes penetrated through the endothelial monolayer into a filter in a time- and dose-dependent manner. This effect could be mimicked by increasing the cytosolic cAMP levels in the endothelial cells either by forskolin or dibutyryl-cAMP. Concomitantly we were able to show that IL-1 increased the cytosolic cAMP levels in endothelial cells. An inhibitor of adenylate cyclase, ddAdo, decreased both the IL-1-induced cAMP elevation and lymphocyte penetration. A protein kinase A inhibitor HA 1004 could inhibit the IL-1-induced lymphocyte penetration, where as protein kinase C (N-(2-guamidino-ethyl)-5-isoquinolinesyl foamide hydrocloride) and calcium-calmodulin (N-(6-aminohexyl)-5-chloro-1-naphthalensulfanamide) inhibitors had no effect. Adding dibutyryl-cGMP or calcium ionophore to the endothelial cells could not mimic IL-1-induced penetration and finally IL-1 did not induce PKC translocation in endothelial cells. These data support the view that IL-1 acts via cAMP as a second messenger in regard to lymphocyte penetration through endothelial cells. The above data demonstrate that IL-1-induced lymphocyte penetration through endothelial cells and that this IL-1-induced signal is transduced via cAMP in endothelial cells.

Scatter factor regulates vascular endothelial cell motility.

Abstract: Scatter factors (SFs) are mesenchymal cellderived cytokines which stimulate epithelial motility. SF purified from ras-transformed 3T3 cell supernatants markedly stimulated vascular endothelial cell migration at < 100 pM. Preliminary studies suggest endothelial lines with cobblestone (epithelioid) morphology respond to SF, while those lines with elongated cells do not respond. SFs may play roles in development and tissue repair.

Platelet-derived Endothelial Cell Growth Factor

Abstract: Platelet-derived endothelial cell growth factor (PD-ECGF) is a 45 kDa single chain polypeptide, which stimulates the DNA synthesis and chemotaxis of endothelial cells in vitro and angiogenesis in vivo. Purification from human platelets and cDNA cloning from a human placental cDNA library, revealed that PD-ECGF is a novel type of peptide without sequence similarity to hitherto known proteins. PD-ECGF is present in human platelets and placenta, and is produced by certain normal and transformed cultured cells; it lacks a hydrophobic leader sequence and most of the protein remains inside the producer cells. Analysis of PD-ECGF produced by cultured cells, revealed that it contains nucleotide(s) covalently bound to serine residues. The in vivo function of PD-ECGF is not known; its target cell specificity and tissue distribution suggest roles in angiogenesis of the placenta and in the maintenance of the integrity of the endothelial cell layer of blood vessels. PD-ECGF may have a clinical utility in the stimulation of wound healing and re-endothelialization of vessels.