Interaction of tissue plasminogen activator with a human endothelial cell 45-kilodalton plasminogen receptor

1994 ◽  
Vol 72 (3-4) ◽  
pp. 126-131 ◽  
Author(s):  
Anil K. Dudani ◽  
Agatha Pluskota ◽  
Peter R. Ganz
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Receptor Binding ◽  
Umbilical Vein ◽  
Annexin Ii ◽  
Cell Protein ◽  
Specific Manner ◽  
Tissue Plasminogen

We have investigated the interaction of tissue plasminogen activator (tPA) with endothelial cell proteins of the human umbilical vein using the technique of ligand blotting. It was observed that tPA interacted with a 45-kilodalton (kDa) endothelial cell protein which appeared to be similar to the 45-kDa plasminogen receptor. Binding of tPA to the 45-kDa protein could be inhibited by excess cold tPA. Morever, excess lysine could inhibit the binding of tPA to the 45-kDa protein in both coincubation and reversibility experiments. These studies indicated that like plasminogen, tPA interacts with the 45-kDa protein in a kringle-dependent and specific manner. To confirm that tPA and plasminogen are interacting with the same protein, we investigated the effect of excess cold plasminogen on tPA binding and excess cold tPA on plasminogen binding in reversibility experiments. It was observed that binding of tPA to the 45-kDa protein was reduced by plasminogen and vice versa. In addition, the 45-kDa protein did not cross-react with antibodies to annexin II, a 40-kDa protein that binds plasminogen and tPA. These latter properties distinguish the 45-kDa receptor from plasminogen/tPA-binding proteins described by others. Therefore, the above studies suggest that the 45-kDa protein represents a unique plasminogen/tPA receptor on human venous endothelial cells.Key words: plasminogen, tissue plasminogen activator, endothelial cells, receptors.

Effect of Lipoprotein(a) and LDL on Plasminogen Binding to Extracellular Matrix and on Matrix-dependent Plasminogen Activation by Tissue Plasminogen Activator

1996 ◽  
Vol 75 (03) ◽  
pp. 497-502 ◽  
Author(s):  
Hadewijch L M Pekelharing ◽  
Henne A Kleinveld ◽  
Pieter F C.C.M Duif ◽  
Bonno N Bouma ◽  
Herman J M van Rijn
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Single Step ◽  
Plasminogen Activation ◽  
Structural Homology ◽  
Tissue Plasminogen ◽  
Umbilical Vein Endothelial Cells

SummaryLp(a) is an LDL-like lipoprotein plus an additional apolipoprotein apo(a). Based on the structural homology of apo(a) with plasminogen, it is hypothesized that Lp(a) interferes with fibrinolysis. Extracellular matrix (ECM) produced by human umbilical vein endothelial cells was used to study the effect of Lp(a) and LDL on plasminogen binding and activation. Both lipoproteins were isolated from the same plasma in a single step. Plasminogen bound to ECM via its lysine binding sites. Lp(a) as well as LDL were capable of competing with plasminogen binding. The degree of inhibition was dependent on the lipoprotein donor as well as the ECM donor. When Lp(a) and LDL obtained from one donor were compared, Lp(a) was always a much more potent competitor. The effect of both lipoproteins on plasminogen binding was reflected in their effect on plasminogen activation. It is speculated that Lp(a) interacts with ECM via its LDL-like lipoprotein moiety as well as via its apo(a) moiety.

Herpes Simplex Virus Decreases Endothelial Cell Plasminogen Activator Inhibitor

1993 ◽  
Vol 69 (03) ◽  
pp. 253-258 ◽  
Author(s):  
Robert A Bok ◽  
Harry S Jacob ◽  
Jozsef Balla ◽  
Margaret Juckett ◽  
Theresa Stelle ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Umbilical Vein ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Plasminogen ◽  
Simplex Virus ◽  
Activator Inhibitor ◽  
Pai 1

SummaryHerpes simplex virus (HSV) infection is histopathologically associated with vascular injury, fibrinoid necrosis and inflammatory cell infiltrates. We have previously shown in vitro that HSV infection of human umbilical vein endothelial cells (HUVEC) promotes a procoagulant phenotype manifest by the induction of tissue factor, the loss of thrombomodulin, and an increase in platelet adhesion. In these studies we examined the effects of HSV infection on HUVEC plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (t-PA). HSV infection caused the loss of PAI-1 in the extracellular matrix (ECM) and that released into the supernatant of HUVEC. Both activity and antigen levels of the Serpin inhibitor are diminished as a result of HSV infection. The loss of inhibitor is not secondary to diminished vitronectin (Vn), the primary binding protein of PAI-1 in the ECM, but appears to be secondary to decreased synthesis at the RNA level. Tissue plasminogen activator (t-PA). synthesis is also decreased in endothelial HSV infection. PAI-1 loss may further promote a procoagulant phenotype in HSV infection in vivo.

Specificity of the Thrombin-Induced Release of Tissue Plasminogen Activator from Cultured Human Endothelial Cells

1986 ◽  
Vol 56 (02) ◽  
pp. 115-119 ◽  
Author(s):  
Eugene G Levin ◽  
David M Stern ◽  
Peter P Nawroth ◽  
Richard A Marlar ◽  
Daryl S Fair ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Protein C ◽  
Primary Cultures ◽  
Activated Protein C ◽  
Specific Inhibitor ◽  
Factor Xa ◽  
Human Endothelial Cells ◽  
Tissue Plasminogen

SummaryThe addition of thrombin (9 nM) to primary cultures of human endothelial cells induces a 6- to 7-fold increase in the rate of release of tissue plasminogen activator (tPA). Several other serine proteases which specifically interact with endothelial cells were also analyzed for their effect on tPA release. Gamma-thrombin, an autocatalytic product of α-thrombin, promoted tPA release but was less effective than α-thrombin. A maximum increase of 5.5-fold was observed, although a concentration of γ-thrombin 20 times greater than α-thrombin was required. The response to Factor Xa was similar to α-thrombin, although the stimulation was significantly reduced by the addition of hirudin or DAPA suggesting that prothrombin activation was occurring. The simultaneous addition of prothrombin with Factor Xa resulted in enhanced tPA release equal to that observed with an equimolar concentration of active α-thrombin. Thus, under these conditions, Factor Xa-cell surface mediated activation of prothrombin can lead to a secondary effect resulting from cell-thrombin interaction. Activated protein C, which has been implicated as a profibrinolytic agent, was also tested. No change in tPA release occurred after the addition of up to 325 nM activated protein C in the presence or absence of proteins. Factor IXa and plasmin were also ineffective. The effect of thrombin on the endothelial cell derived plasminogen activator specific inhibitor was also studied. Thrombin produced a small but variable release of the inhibitor with an increase of less than twice that of non-thrombin treated controls.

Sign in / Sign up

Export Citation Format

Share Document