Showing papers on "Vascular endothelial growth factor B published in 1988"

Tumor necrosis factor suppresses transcription of the thrombomodulin gene in endothelial cells.

Abstract: Tumor necrosis factor (TNF) dramatically alters the levels of various surface components of the blood vessel wall, such as blood coagulation enzyme receptors, leukocyte-adhesive receptors, and class 1 major histocompatibility complex antigens, which may have relevance to its effects in septic shock, angiogenesis, and tumor growth. However, the precise mechanism by which the cytokine is able to accomplish this remodeling of the endothelial cell surface has not been defined. We have demonstrated that exposure of bovine and human endothelial cells to TNF leads to suppression of the functional cell surface thrombin receptor, thrombomodulin (TM), and TM mRNA of virtually identical magnitude. The cytokine has no significant effect on the stability of TM mRNA or endothelial receptor turnover. Nuclear run-on studies reveal that the treatment of endothelial cells with TNF for short periods reduces TM gene transcription to as little as 3% of control values and that this inhibition does not require new protein synthesis.

Comparative endocrinology-paracrinology-autocrinology of human adult large vessel endothelial and smooth muscle cells.

Abstract: Endothelial and smooth muscle cells were isolated from human adult large blood vessels to compare their proliferative response to hormones and growth factors. Neural extracts and the medium from differentiated hepatoma cells were used as concentrated sources of required hormones and growth factors that supported both cell types. Active hormones and growth factors were identified from the neural extracts and hepatoma medium by substitution or direct isolation and biochemical characterization. Epidermal growth factor, lipoproteins, and heparin-binding growth factors elicited growth-stimulatory effects on both endothelial and smooth muscle cells. Both types of human vascular cells displayed 7600 to 8600 specific heparin-binding growth factor receptors per cell with a similar apparent dissociation constant (Kd) of 200 to 250 pM. Heparin modified the response of both endothelial and smooth muscle cells to heparin-binding growth factors dependent on the type of heparin-binding growth factor and amount of heparinlike material present. In addition, heparin exerted a growth factor-independent inhibition of smooth muscle cell proliferation. Platelet-derived growth factor, insulinlike growth factors, and glucocorticoid specifically supported proliferation of smooth muscle cells with no apparent effect on endothelial cell proliferation. Growth-factorlike proteinase inhibitors had an impact specifically on endothelial cell proliferation. Transforming growth factor beta was a specific inhibitor of endothelial cells, but had a positive effect on smooth muscle cell proliferation. The results provide a framework for differential control of the two vascular cell types at normal and atherosclerotic blood vessel sites by the balance among positive and negative effectors of endocrine, paracrine and autocrine origin.

Regulation of the Coagulation System by Vascular Endothelial Cells

Abstract: The endothelium plays an active role in the regulation of the coagulation mechanism. Multiple anticoagulant properties are operative on the cell surface in homeostasis. In the protein C/protein S path

Lipoprotein receptors and endothelial cells.

Abstract: The interaction of lipoproteins with endothelial receptors can result in alterations in macromolecular transport, in changes in monocyte adherence to the endothelium, and in the production of monocyte chemotactic factor by the endothelium. Monocyte migration in response to such factors can further alter lipoprotein transport into the subendothelial space, and all of these factors may play a role in the development of the atherosclerotic lesion.

P2-purinergic receptors in vascular endothelial cells: from concept to reality.

Abstract: ATP exerts at least 2 actions on arterial endothelial cells: it stimulates the release of endothelium-derived relaxing factor, a still unidentified vasodilator, and of prostacyclin, a potent inhibitor of platelet aggregation. A study of agonist specificity indicates that these responses are mediated by P2-purinergic receptors. We have now demonstrated that in these cells, the P2-receptors are coupled to a phospholipase C hydrolysing phosphatidylinositol-bisphosphate and that this coupling involves a pertussis toxin-sensitive GTP-binding regulatory protein.

Epidermal growth factor stimulates prostacyclin production by cultured human vascular endothelial cells.

Abstract: Epidermal growth factor (EGF) stimulated prostacyclin (PGI2) production by cultured human umbilical vein endothelial cells, as measured by radioimmunoassay of its stable metabolite 6-keto-prostaglandin F1 alpha. This effect of EGF was dose-dependent, the lowest stimulatory concentration of EGF was 1.0 ng/ml and 100 ng/ml caused a 2.7 +/- 0.3 (mean +/- SEM) fold increase in the PGI2 synthesis. The stimulation appeared at 3-6 h of incubation and lasted at least 24 h. It was suppressed by EGF antibodies and blocked by protein synthesis inhibitor cycloheximide. Cells preincubated 12 h with EGF released also higher amounts of PGI2 when incubated with thrombin for 5 min. It is concluded that EGF liberated from platelets during aggregation may prevent local thrombogenesis and atherogenesis by stimulating the release of the antiaggregatory, vasodilatory PGI2 from vascular endothelial cells.

Vascular endothelial cells and hematopoietic regulation.

Abstract: Vascular endothelial cells elaborate growth factors which support the proliferation and differentiation of hematopoietic progenitor cells. Both the regulation and potential biological significance of growth factor production by endothelial cells are reviewed.

Fatty acid metabolism and the vascular endothelial cell. New thoughts about old data.

Abstract: Fatty acid metabolism by vascular endothelial cells occurs both under basal conditions and following endothelial cell stimulation or injury. Under basal conditions, endothelial cells are metabolically

Agonist-induced polyphosphoinositide breakdown in cultured human endothelial and vascular smooth muscle cells.

Abstract: Human aortic endothelial cells and smooth cells (SMC) from human aorta and coronary arteries were grown in culture. Subcultured vascular SMC retained several important features of human vascular SMC in situ, for example, vimentin-type intermediate filaments, smooth muscle myosin, a well-developed microfilament system, and expression of caldesmon protein involved in the regulation of contraction in smooth muscle. Aortic endothelial cells were shown to possess functional receptors to histamine, thrombin, serotonin, acetylcholine, bradykinin, platelet activating factor (PAF), angiotensin II, vasopressin, prostaglandin E2 (PGE2), and U46619, a stable analog of thromboxane A2. All these substances stimulated polyphosphoinositide (PPI) breakdown in endothelium. Thrombin, histamine, and PAF were the most potent activators. The response of aortic SMC to the same panel of agonists were different. Serotonin, histamine, and angiotensin II produced higher levels of inositol phosphates (IP, IP2, IP3) in SMC than in endothelium. Responses to acetylcholine, bradykinin, and PGE2 were weak and inferior to those of endothelial cells. Other agents evoked approximately equivalent responses in both cell types. Coronary artery SMC resembled aortic SMC in the high extent of PPI hydrolysis after stimulation with serotonin and histamine. The complete inability of angiotensin II and vasopressin to cause accumulation of inositol phosphates in coronary SMC contrasted with the presence of functional receptors to these hormones on aortic SMC. We conclude that the effect of vasoactive agents on human vascular cells may be realized via activation of PPI hydrolysis. Agonists with reported strong vasoconstrictor action seem to stimulate preferential PPI hydrolysis in SMC, whereas endothelium-dependent relaxers cause more pronounced PPI breakdown in endothelial cells. Peculiarities of angiotensin II and vasopressin receptor expression and/or coupling in human aorta and coronary artery SMC may be relevant for understanding the selective action of agonists on human vessels.

Current concepts of vascular occlusive disease. The significance of endothelial trauma and smooth muscle cell proliferation.

Abstract: It is accepted that vascular smooth muscle cell proliferation is the central event in occlusive vascular disease. Why this occurs in the lesion of atherosclerosis is not yet known for certain but it is probably related in some way to chronic minor endothelial trauma. Intimai hyperplasia, on the other hand, is related to mechanical trauma of the endothelium.