Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During cardiopulmonary bypass (CPB) mechanical stress and the contact of blood with artificial surfaces lead to the activation of pro- and anticoagulant systems and the complement cascade, and to changes in cellular components. This phenomenon causes the "postperfusion-syndrome", with leukocytosis, increased capillary permeability, accumulation of interstitial fluid, and organ dysfunction. In this study, we focused on the influence of the extracorporeal circulation, sternotomy, and heparin administration on the activation of coagulation and fibrinolysis. In 15 patients we investigated coagulation parameters before, during and post CPB, i.e., fibrinogen, antithrombin (AT) III, thrombin-antithrombin complex (TAT), prothrombin fragments F1 + 2 (F1 + 2), factor (F) XIIa, tissue factor (TF), and parameters of the fibrinolytic system, i.e., plasmin-antiplasmin-complex (PAP), D-dimer, tissue-plasminogen-activator (tPA), urokinase-type plasminogen activator (uPA), and plasminogen-activator inhibitor type 1 (PAI 1). The results demonstrate distinct alterations in the above mentioned parameters. Despite administration of a high dose of heparin (activated clotting time [ACT] > 450s) combined with a low dose of aprotinin, activation of the coagulation and fibrinolytic pathways was observed. We found this activation was mainly caused by CPB and not by sternotomy. The activation of coagulation was due to foreign surface contact (F XII => F XIIa) as well as to an effect of tissue factor release in the late phase of CPB. The enhanced fibrinolytic activity during CPB was, at least in part, caused by tPA and was followed by PAI 1 release.
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PMID:Changes in coagulation and fibrinolytic parameters caused by extracorporeal circulation. 924 50

On the basis of an array of preclinical experimental results, it has been widely assumed that endothelin-1 (ET-1) may affect blood coagulation, fibrinolysis, and endothelial cell function, thereby playing a pathophysiological role in various cardiovascular diseases in humans. However, confirmation of this assumption is still lacking. ET-1 or placebo was administered intravenously to 12 healthy volunteers in a prospective, randomized, double-blind, crossover trial. Pathophysiologically relevant concentrations of ET-1 (an approximate threefold increase of normal blood levels) causing hemodynamic effects were reached by continuous intravenous infusion for 6 hours. Components of the coagulation (thrombin-antithrombin complexes, prothrombin fragment F1 + 2, activated factor VII, and factor VII antigen) and fibrinolytic (fibrin split product D-dimer, plasmin-plasmin inhibitor complex, tissue-type plasminogen activator, urokinase-type plasminogen activator, and plasminogen activator inhibitor-1) systems and markers of endothelial cell perturbation/dysfunction (von Willebrand factor and thrombomodulin) were measured before the start of infusion and after 2, 6, 12, and 24 hours. Comparing changes in the plasma concentrations of these parameters during and after infusion of ET-1 and placebo, we found no specific effects of ET-1. In contrast to previous reports from preclinical experiments, ET-1 does not appear to affect coagulation or fibrinolysis, nor does this peptide induce relevant endothelial cell perturbations in humans.
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PMID:Evidence against an effect of endothelin-1 on blood coagulation, fibrinolysis, and endothelial cell integrity in healthy men. 940 67

Activation and inhibition of coagulation and fibrinolysis was analyzed in bronchoalveolar lavage (BAL) fluids obtained from endotoxin-challenged chimpanzees. The mediatory role of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) on endotoxin-induced changes in bronchoalveolar coagulation and fibrinolysis was investigated in experiments in which the infusion of endotoxin was combined with the administration of monoclonal anti-TNF-alpha or anti-IL-6 antibodies. Endotoxin infusion elicited a marked increase in bronchoalveolar thrombin generation as measured by levels of prothrombin activation fragment F1+2 and thrombin-antithrombin complexes. Markers for intrinsic pathway activation were not detectable, suggesting that the thrombin generation was mediated by the tissue factor-dependent route. Levels of antithrombin were low before the injection of endotoxin and not detectable hereafter. The administration of anti-IL-6 antibody completely abolished the endotoxin-induced activation of bronchoalveolar coagulation, whereas treatment with anti-TNF-alpha antibody only partly inhibited this effect. Bronchoalveolar fibrinolytic activity, due to urokinase-type plasminogen activator (u-PA), was significantly depressed after endotoxin injection, mainly due to a striking increase in plasminogen activator inhibitor-2 levels in BAL fluid. The endotoxin-induced effects on bronchoalveolar fibrinolysis could be blocked by the simultaneous administration of anti- TNF-alpha antibodies. We conclude that endotoxemia results in the activation of bronchoalveolar coagulation, which is apparently mediated by the tissue factor route of coagulation activation and which may be amplified by consumption of antithrombin III. Bronchoalveolar fibrinolytic activity is significantly abolished by increased levels of mainly PAI-2 after the injection of endotoxin. The endotoxin-induced effects on bronchoalveolar coagulation appears to be mediated by IL-6, whereas TNF-alpha seems to be the pivotal mediator of the endotoxin-induced depression of bronchoalveolar fibrinolysis.
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PMID:Differential effects of anti-cytokine treatment on bronchoalveolar hemostasis in endotoxemic chimpanzees. 965 12

A total of 71 pregnant women diagnosed by ultrasound to have viable fetus in late mid- trimester pregnancies of normal, IUGR, hydrops fetalis and chromosomal anomalies were studied for their coagulation, fibrinolytic and inhibitor levels with association on eventual obstetrics outcome. A hypercoagulable state was observed in all the pregnancies studied. However, higher hypercoagulation evidenced by significantly raised prothrombin formation and clot elasticity together with higher levels of D-dimer, uPA antigen and PAI-1 than observed in normal pregnancy suggests a hyperfibrinolytic/inhibitor state in hydrops fetalis pregnancy associated with bad obstetric outcome. In IUGR pregnancy associated with good outcome further enhanced clot elasticity was seen whilst no significant differences were observed in pregnancy with chromosomal anomalies when compared to uncomplicated normal pregnancy. Our study suggests that in hydrops fetalis pregnancy, further enhanced prothrombin formation and hyperfibrinolysis/inhibitor at late mid-trimester is associated with a poor obstetric outcome.
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PMID:Coagulation and fibrinolysis in viable mid-trimester pregnancies of normal, intrauterine growth retardation, chromosomal anomalies and hydrops fetalis and their eventual obstetric outcome. 1073 4

Fibrinolytic and coagulation properties of capybara (Hydrochaeris hydrochaeris, LINNAEUS, 1766) plasma were analysed and the results compared to the guinea-pig (Cavia porcellus), a close relative. Capybara fibrinogen was isolated and fibrinolysis of its plasma was carried out in a homologous system and with bovine fibrin. Undiluted plasma did not have fibrinolytic activity on fibrin plates; euglobulins gave a dose-related response. Zymography of capybara and guinea-pig plasma gave the same patterns of activity as human or bovine plasma. Human urokinase (UK) and tissue plasminogen activator (t-PA) produced lysis in capybara fibrin plates. Streptokinase (SK) (500 IU/ml) did not activate capybara or guinea-pig plasma. In this system, human plasma was extensively activated. Coagulation tests for both species of rodent were prolonged. The capybara showed values for prothrombin time (PT) shorter than activated thromboplastin time (APTT). The guinea-pig, as already shown, had longer PT values. Factors X and VII were very low for capybara and guinea-pig when tested using reference curves and diagnostic kits for human plasma. It is suggested that the capybara could be a valuable laboratory animal considering its size and closeness to the guinea-pig, and this could allow for the provision of materials from one single animal when convenient or necessary.
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PMID:Coagulation and fibrinolysis in capybara (Hydrochaeris hydrochaeris), a close relative of the guinea-pig (Cavia porcellus). 1077 37

In 1967 we reported for the first time five cases of an acquired bleeding disorder in humans which developed after contact with saturnidae caterpillars. Since that time, other cases have been reported in Brazil, French Guyana, Peru, Paraguay and Argentina. The caterpillars have been identified as Lonomia achelous (LA) in Venezuela and northern Brazil and as Lonomia obliqua (LO) in southern Brazil. All patients present pain and a burning sensation at the site of contact. Within a few hours hematomas and hematuria are seen in combination with intracerebral and intraperitoneal hemorrhage (in some cases also renal failure). Hematological tests show: mild anemia with leucocytosis; prolonged PT, PTT and ThT; decreased fibrinogen, factor V, factor XIII, plasminogen and alpha2-antiplasmin levels; increased factor VIII:c, von Willebrand factor, and FDPs/D-dimers levels with normal ATIII and platelets. Factor VII, factor II and PC levels varied. Several activities similar to or directed against blood clotting factors have been identified in LA: fibrinolytic enzymes, which degrade fibrinogen producing abnormal FDPs; prothrombin activators: one direct and one factor Xa-like; a thermostable factor V activator; a thermolabile factor V inhibitor; a factor XIII proteolytic/urokinase-like activity; and a kallikrein-like activitiy. In LO three activities have been described: a prothrombin activator called 'Lonomia obliqua prothrombin activator protease' (LOPAP); a factor X activator; and a phospholipase A(2)-like activity called Lonomiatoxin. No fibrinolytic activity has been described in LO. Subcutaneous injection of crude hemolymph and some chromatographic fractions of LA induce a decrease in fibrinogen, plasminogen and factor XIII. Intravenous injection of factor XIII proteolytic/urokinase-like activity induce a dose-dependent thrombolysis with a decrease in plasmatic factor XIII without hemorrhagic manifestations. Intradermal injection of LO bristle extracts in rats and rabbits produce incoagulability whereas intravenous injection of LOPAP induced DIC in mice.
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PMID:Lonomia genus caterpillar toxins: biochemical aspects. 1108 23

The incomplete penetrance of thrombosis in familial protein C deficiency suggests disease occurs when this deficit is combined with additional abnormalities in the hemostatic system. The pattern of inherited thrombophilia in the Vermont II kindred, which is affected by a clinically dominant type I protein C deficiency, provides strong evidence for a second unidentified gene that segregates independently of protein C deficiency and increases susceptibility to thrombosis. To test the second gene hypothesis, thirty-four candidate genes for proteins involved in hemostasis or inflammation were tested as the unknown defect, using highly polymorphic short tandem repeat (STR) markers in an informative subset (n = 31) of the kindred. The genes considered are; alpha-fibrinogen, beta-fibrinogen, gamma-fibrinogen, prothrombin, tissue factor, factor V, protein S, complement component 4 binding protein, factor XI, factor XII, factor XIIIa, factor XIIIb, histidine rich glycoprotein, high molecular weight kininogen, kallikrein, von Willebrands factor, platelet factor 4, thrombospondin, antithrombin III, alpha-1-antitrypsin, thrombomodulin, plasminogen, tissue plasminogen activator, urokinase plasminogen activator, plasminogen activator inhibitor-1, plasminogen activator inhibitor-2, protein C inhibitor, alpha-2-plasmin inhibitor, kallistatin, lipoprotein a, interleukin 6, interleukin 1, cystathionine-beta-synthase, and methylenetetrahydrofolate reductase. Mutations in many of these genes have been previously established as independent risk factors for thrombosis. However, linkage analysis provided no evidence to implicate any of the candidate genes as the second inherited factor that promotes thrombophilia in this kindred.
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PMID:Genetic screening of candidate genes for a prothrombotic interaction with type I protein C deficiency in a large kindred. 1120 93

Plasma hyaluronan biding protein (PHBP) is a novel serine protease, which has an amino acid sequence homology to that of hepatocyte growth factor activator (HGFA), and has a similar domain structure to that of urinary plasminogen activator (u-PA), found in human plasma. We searched the PHBP substrate in human plasma by measuring the digested protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that fibrinogen and fibronectin were the major substrates of PHBP. PHBP cleaved the alpha-chain at multiple sites and the beta-chain between lysine53 and lysine54 but not the gamma-chain of fibrinogen. Therefore, PHBP did not initiate the formation of the fibrin clot and did not cause the fibrinolysis directly. PHBP did not cleave (activate) prothrombin and plasminogen, but it converted the inactive single chain urinary plasminogen activator to the active two chain form.
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PMID:Identification of the substrates for plasma hyaluronan binding protein. 1121 80

Sepimostat mesilate (FUT-187: 6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl) amino] benzoate dimethane sulfonate) is a newly synthesized serine protease inhibitor. In the present study, the oral administration of FUT-187 inhibited stasis-induced venous thrombosis in rats. We supposed that such effect of this compound was caused by its inhibitory effect on coagulation. However, the dose of FUT-187 that was effective at inhibiting thrombosis (10 and 30 mg/kg, po) had no effect on the plasma recalcification time (PRCT), activated partial thromboplastin time (APTT) and prothrombin time (PT) in rats. Therefore, we investigated the fibrinolytic activity of FUT-187 in rat plasma. The results revealed that rat plasma after FUT-187 administration exhibited increased amidolytic activity for a plasmin-, tissue-type plasminogen activator (t-PA)-, urokinase-type plasminogen activator (u-PA)-, factor Xa-, factor XIa- and factor XIIa-sensitive synthetic peptide substrate. On the other hand, the inhibitory effect of FUT-187 in the thrombosis model was not affected by additional treatment with epsilon-amino-n-caproic acid (EACA), a plasmin-mediated fibrinolysis inhibitor. These results suggest that even if FUT-187 enhanced fibrinolysis, it would be independent of a plasmin-mediated fibrinolytic pathway. To characterize the fibrinolytic activity, which might reduce the thrombus weight in the thrombosis model administered FUT-187, we carried out fibrinogen zymography, and clarified that FUT-187 enhanced the formation of a 20-kDa fibrinolytic fragment. Interestingly, this fragment was not affected by t-PA. Consequently, we consider that the inhibitory effect of FUT-187 on venous thrombosis model is caused by fibrinolysis, which is attributable to the 20-kDa fragment, rather than by inhibition of thrombus formation.
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PMID:Effect of sepimostat mesilate on experimental venous thrombosis in rats. 1122 42

Structural and biological characteristics of a recently described plasma serine protease, which displayed factor VII as well as pro-urokinase-activating properties in vitro, indicated a dual role for this factor VII-activating protease (FSAP) in hemostasis. Only the active protease (two-chain FSAP) has been isolated from plasma and from a prothrombin complex concentrate, whereas activators of the proenzyme have not been identified so far. After purification of the FSAP proenzyme from cryo-poor plasma by adsorption to an immobilized mAb and subsequent ion-exchange chromatography, activation to generate two-chain FSAP was followed by a direct chromogenic assay as well as by the ability of two-chain FSAP to activate pro-urokinase. Purified single-chain FSAP underwent autoactivation leading to the typical protease two-chain pattern and subsequent degradation products, as demonstrated by Western-blotting analysis using a site-specific mAb. This autoactivation was significantly enhanced in the presence of heparin, whereas Ca2+ ions stabilized single-chain FSAP (the proenzyme) resulting in slower autoactivation kinetics. Correspondingly, the heparin-augmented reaction, which was associated with autodegradation particularly of the protease domain, was slowed down by co-incubation with Ca2+. Of the other proteases and cofactors tested, only urokinase (uPA) was able to generate the typical two-chain FSAP pattern. Studies with different forms of uPA suggest that the catalytic activity of pro-urokinase/uPA is needed to activate single-chain FSAP, indicating that it is the only hemostatic protease that can act as a physiological activator of FSAP.
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PMID:Factor VII and single-chain plasminogen activator-activating protease: activation and autoactivation of the proenzyme. 1143 47


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