摘要:

The regulation of the fibrinolytic system is of critical importance during hemostasis, wound repair, neoplasia, inflammation, and a variety of other biologic processes. This control is achieved in a large part through the action of specific plasminogen activator inhibitors (PAIs). Cultured endothelial cells (ECs) produce type 1 PAI (PAI-1), the physiologic inhibitor of tissue-type plasminogen activator. PAI-1 is one of the most highly regulated of the fibrinolytic components produced by ECs. Its synthesis is modulated by a variety of compounds including endotoxin, thrombin, transforming growth factor β, interleukin 1 and tumor necrosis factor α. Recent studies suggest that PAI-1 is synthesized by ECs as an active molecule, but that it spontaneously decays into a latent form in solution. Specific components present in the extracellular matrix of ECs and in plasma bind to PAI-1 and prevent this inactivation. The unexpected finding that cultured ECs also produce type 2 PAI (PAI-2) introduces a previously unsuspected level of complexity to our understanding of this system and raises the possibility that the altered fibrinolytic activity of ECs following various treatments, or of blood in certain individuals, may reflect changes in either one of these inhibitor

ISSN:1424-8832    

DOI:10.1159/000215815

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

This review summarizes current insights in the importance of endothelium in the interaction of platelets with the subendothelium. A greater part of the results described are obtained with the use of cultured vessel wall cells. The following subjects are discussed: (1) the pro- and antithrombotic properties of the endothelial cells; (2) the synthesis of subendothelium by the endothelial cells and the influence of the composition of the subendothelium on its reactivity towards blood platelets; (3) the effect of (purified) matrix and plasma proteins on the adhesion process, and (4) various abnormalities of platelet adhesion are discussed that lead to enhanced bleeding tendency or to increased thrombus formation.

ISSN:1424-8832    

DOI:10.1159/000215816

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215817

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

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 very active and rapidly turn over triglycerides and synthesize 13-hydroxyoctadecadienoic acid from linoleic acid via the cytosolic enzyme, hω6-lipoxygenase. When endothelial cells are stimulated (or injured), these pathways are turned off, and, instead, arachidonic acid is liberated from the membrane phospholipids and metabolized into prostacyclin via the cyclooxygenase enzyme. The biological relevance of these two fatty acid metabolites is discussed in respect to the regulation of cell/cell interactions during both ‘homeostasis’ and ‘i

ISSN:1424-8832    

DOI:10.1159/000215818

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Studies on the identification of molecules involved in the interaction of endothelial cells with their environment have led to the discovery of membrane receptors that are similar or identical to previously characterized platelet membrane glycoproteins. Some of these surface molecules belong to a family of widely distributed cell adhesion receptors, termed integrins. One of the integrins, the vitronectin receptor, a platelet glycoprotein (GP) IIb-IIIa related molecule, has now been characterized in some detail. It is a heterodimeric molecule consisting of a subunit similar, but not identical, to GP IIb and a subunit (almost) identical to GP IlIa. Alloantigens (Zwa, Zwb, and Yukb) expressed by platelet GP IlIa are also expressed by endothelial GP IlIa. The vitronectin receptor is involved in the adhesion of endothelial cells to Arg-Gly-Asp-containing immobilized proteins such as vitronectin, fibrin-ogen, and von Willebrand factor. Endothelial cells also express a molecule indistinguishable from the platelet VLA-2 or GP Ia-IIa complex which is another member of the integrin family. This molecule functions as a platelet collagen receptor, and perhaps it also functions as a collagen receptor on endothelial cells. By mediating cell-matrix contact, the vitronectin receptor, VLA-2 and other similar receptors might be involved in the anchorage of endothelial cells to their extracellular matrix.

ISSN:1424-8832    

DOI:10.1159/000215819

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215820

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215821

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215822

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215804

出版商:S. Karger AG    

年代:1988

数据来源: Karger