Mechanism of the stimulatory effect of native fucoidan, highly sulfated fucoidan and heparin on plasminogen activation by tissue plasminogen activator: The role of chloride

2004 ◽  
Vol 29 (4) ◽  
pp. 269-275 ◽  
Author(s):  
DeShawn Lang ◽  
Talya Williams ◽  
Altovise Phillips ◽  
V. M. Doctor
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Plasminogen Activation ◽  
Tissue Plasminogen

Tissue Plasminogen Activator in Human Megakaryocytes and Platelets: Immunocytochemical Localization, Immunoblotting and Zymographic Analysis

1988 ◽  
Vol 59 (03) ◽  
pp. 529-534 ◽  
Author(s):  
C Jeanneau ◽  
Y Sultan
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Blood Platelets ◽  
Fibrinolytic System ◽  
Plasminogen Activation ◽  
Sds Page ◽  
Tissue Plasminogen ◽  
Zymographic Analysis

SummaryTwo approaches were used to identify and characterize the presence of tissue plasminogen activator (t-PA) in megakaryocytes and platelets. We investigated the fibrinolytic activity of human megakaryocytes (MK) and platelets. The presence of t-PA antigen in megakaryocytes and platelets was demonstrated using immunocytochemical techniques and polyclonal or monoclonal antibodies specific for t-PA. When cells were applied to fibrin plates, lysis zones developed around isolated human megakaryocytes, whereas no fibrinolytic activity appeared when either intact washed platelets or platelet lysate were deposited. After SDS-PAGE of platelet and MK extracts (Triton X-100) immunoblotting and peroxidase staining identified t-PA antigen in several bands. Zymographic analysis of SDS-PAGE carried out on fibrin film overlays identified one or two zones corresponding to free or complexed t-PA. These results indicate that t-PA is present in platelets as well as in the precursor cells, however, in platelets, t-PA may not be immediately available for plasminogen activation and fibrin degradation. From our findings and from previous work of others, it appears that platelets may either activate or inhibit the fibrinolytic system. Therefore the conditions of plasminogen activation by platelet t-PA and plasmin inhibition by platelet α2-antiplasmin or other inhibitors have to be precised before the role of platelets in clot dissolution is understood.The physiological role of platelets in fibrinolysis and clot dissolution remains unclear. In 1953, the antifibrinolytic activity of blood platelets was demonstrated (1) and in the early 1960’s a fibrinolytic activity, increasing with platelet concentration in the experimental system, was shown (2, 3). In 1979, it was demonstrated that metabolically active platelets were necessary for platelets to play a role in the fibrinolytic system (4). More recently it was established by Plow and Collen (5) that the specific plasmin inhibitor, α2-antiplasmin is a constituent of platelet α-granules.In the present study, we investigated the fibrinolytic components and activity of human megakaryocytes and platelets, using zymographic and immunochemical techniques. We report here our observations that human megakaryocytes and platelets contain tissue plasminogen (t-PA) which possesses fibrinolytic activity.

scholarly journals Tissue plasminogen activator is a ligand of cation-independent mannose 6-phosphate receptor and consists of glycoforms that contain mannose 6-phosphate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
James J. Miller ◽  
Richard N. Bohnsack ◽  
Linda J. Olson ◽  
Mayumi Ishihara ◽  
Kazuhiro Aoki ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Dependent Manner ◽  
Plasminogen Activation ◽  
Urokinase Plasminogen Activator Receptor ◽  
Plasminogen Activation System ◽  
Extracellular Region ◽  
Glycosylation Sites ◽  
Tissue Plasminogen ◽  
Mannose 6 Phosphate

AbstractPlasmin is the key enzyme in fibrinolysis. Upon interaction with plasminogen activators, the zymogen plasminogen is converted to active plasmin. Some studies indicate plasminogen activation is regulated by cation-independent mannose 6-phosphate receptor (CI-MPR), a protein that facilitates lysosomal enzyme trafficking and insulin-like growth factor 2 downregulation. Plasminogen regulation may be accomplished by CI-MPR binding to plasminogen or urokinase plasminogen activator receptor. We asked whether other members of the plasminogen activation system, such as tissue plasminogen activator (tPA), also interact with CI-MPR. Because tPA is a glycoprotein with three N-linked glycosylation sites, we hypothesized that tPA contains mannose 6-phosphate (M6P) and binds CI-MPR in a M6P-dependent manner. Using surface plasmon resonance, we found that two sources of tPA bound the extracellular region of human and bovine CI-MPR with low-mid nanomolar affinities. Binding was partially inhibited with phosphatase treatment or M6P. Subsequent studies revealed that the five N-terminal domains of CI-MPR were sufficient for tPA binding, and this interaction was also partially mediated by M6P. The three glycosylation sites of tPA were analyzed by mass spectrometry, and glycoforms containing M6P and M6P-N-acetylglucosamine were identified at position N448 of tPA. In summary, we found that tPA contains M6P and is a CI-MPR ligand.

The potentiating effect of platelet on plasminogen activation by tissue plasminogen activator

1985 ◽  
Vol 40 (6) ◽  
pp. 853-861 ◽  
Author(s):  
K. Deguchi ◽  
S. Murashima ◽  
S. Shirakawa ◽  
C. Soria ◽  
J. Soria ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Plasminogen Activation ◽  
Tissue Plasminogen

scholarly journals β2-glycoprotein i is a cofactor for tissue plasminogen activator-mediated plasminogen activation

2009 ◽  
Vol 60 (2) ◽  
pp. 559-568 ◽  
Author(s):  
Chunya Bu ◽  
Lei Gao ◽  
Weidong Xie ◽  
Jainwei Zhang ◽  
Yuhong He ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Plasminogen Activation ◽  
Glycoprotein I ◽  
Tissue Plasminogen

scholarly journals Role of residue Y99 in tissue plasminogen activator

2008 ◽  
Vol 9 (3) ◽  
pp. 619-622 ◽  
Author(s):  
Alessandro Vindigni ◽  
Mollie Winfield ◽  
Youhna M. Ayala ◽  
Enrico Di Cera
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Tissue Plasminogen

In vivo clearance of tissue plasminogen activator: The complex role of sites of glycosylation and level of sialylation

1993 ◽  
Vol 7 (1) ◽  
pp. 15-22 ◽  
Author(s):  
E.S. Cole ◽  
E.H. Nichols ◽  
L. Poisson ◽  
M.L. Harnois ◽  
D.J. Livingston
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Tissue Plasminogen
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