A Specific Immunologic Assay for Functional Plasminogen Activator Inhibitor 1 in Plasma – Standardized Measurements of the Inhibitor and Related Parameters in Patients with Venous Thromboembolic Disease

1992 ◽  
Vol 68 (05) ◽  
pp. 486-494 ◽  
Author(s):  
Malou Philips ◽  
Anne-Grethe Juul ◽  
Johan Selmer ◽  
Bent Lind ◽  
Sixtus Thorsen
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Normal Subjects ◽  
Tissue Type ◽  
Blood Collection ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type Plasminogen Activator ◽  
Significant Difference ◽  
Activator Inhibitor ◽  
Pai 1

SummaryA new assay for functional plasminogen activator inhibitor 1 (PAI-1) in plasma was developed. The assay is based on the quantitative conversion of PAI-1 to urokinase-type plasminogen activator (u-PA)-PAI-l complex the concentration of which is then determined by an ELISA employing monoclonal anti-PAI-1 as catching antibody and monoclonal anti-u-PA as detecting antibody. The assay exhibits high sensitivity, specificity, accuracy, and precision. The level of functional PAI-1, tissue-type plasminogen activator (t-PA) activity and t-PA-PAI-1 complex was measured in normal subjects and in patients with venous thromboembolism in a silent phase. Blood collection procedures and calibration of the respective assays were rigorously standardized. It was found that the patients had a decreased fibrinolytic capacity. This could be ascribed to high plasma levels of PAI-1. The release of t-PA during venous occlusion of an arm for 10 min expressed as the increase in t-PA + t-PA-PAI-1 complex exhibited great variation and no significant difference could be demonstrated between the patients with a thrombotic tendency and the normal subjects.

Abstract T P75: Temporal Profiles of Plasminogen Activator Inhibitor-1 Concentration and Activity Changes in Circulation after Focal Stroke and Tissue Type Plasminogen Activator Administration in Rats

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Qi Liu ◽  
Xiang Fan ◽  
Helen Brogren ◽  
Ming-Ming Ning ◽  
Eng H Lo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type Plasminogen Activator ◽  
Temporal Profiles ◽  
Activator Inhibitor ◽  
Pai 1

Aims: Plasminogen activator inhibitor-1 (PAI-1) is the main and potent endogenous tissue-type plasminogen activator (tPA) inhibitor, but an important question on whether PAI-1 in blood stream responds and interferes with the exogenously administered tPA remains unexplored. We for the first time investigated temporal profiles of PAI-1 concentration and activity in circulation after stroke and tPA administration in rats. Methods: Permanent MCAO focal stroke of rats were treated with saline or 10mg/kg tPA at 3 hours after stroke (n=10 per group). Plasma (platelet free) PAI-1 antigen and activity levels were measured by ELISA at before stroke, 3, 4.5 (1.5 hours after saline or tPA treatments) and 24 hours after stroke. Since vascular endothelial cells and platelets are two major cellular sources for PAI-1 in circulation, we measured releases of PAI-1 from cultured endothelial cells and isolated platelets after direct tPA (4 μg/ml) exposures for 60 min in vitro by ELISA (n=4 per group). Results: At 3 hours after stroke, both plasma PAI-1 antigen and activity were significantly increased (3.09±0.67, and 3.42±0.57 fold of before stroke baseline, respectively, all data are expressed as mean±SE). At 4.5 hours after stroke, intravenous tPA administration significantly further elevated PAI-1 antigen levels (5.26±1.24), while as expected that tPA neutralized most elevated PAI-1 activity (0.33±0.05). At 24 hours after stroke, PAI-1 antigen levels returned to the before baseline level, however, there was a significantly higher PAI-1 activity (2.51±0.53) in tPA treated rats. In vitro tPA exposures significantly increased PAI-1 releases into culture medium in cultured endothelial cells (1.65±0.08) and platelets (2.02±0.17). Conclution: Our experimental results suggest that tPA administration may further elevate stroke-increased blood PAI-1 concentration, but also increase PAI-1 activity at late 24 hours after stroke. The increased PAI-1 releases after tPA exposures in vitro suggest tPA may directly stimulate PAI-1 secretions from vascular walls and circulation platelets, which partially contributes to the PAI-1 elevation observed in focal stroke rats. The underlying regulation mechanisms and pathological consequence need further investigation.

Plasminogen activator inhibitor-1 rises after hemorrhage in rats

1995 ◽  
Vol 268 (6) ◽  
pp. E1065-E1069 ◽  
Author(s):  
M. Yamashita ◽  
D. N. Darlington ◽  
E. J. Weeks ◽  
R. O. Jones ◽  
D. S. Gann
Keyword(s):  
Plasminogen Activator ◽  
High Performance ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Sprague Dawley ◽  
Plasminogen Activator Inhibitor 1 ◽  
Sprague Dawley Rats ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor ◽  
Pai 1

Large hemorrhage leads to hypercoagulability, a phenomenon that has never been well explained. Because an elevation of plasminogen activator inhibitor (PAI)-1 increases procoagulant activity, we have determined whether plasma PAI activity and tissue PAI-1 mRNA are elevated after hemorrhage. Sprague-Dawley rats were bled (20 or 15 ml/kg) 4 days after cannulation. Plasma PAI activity was determined by the capacity of plasma to inhibit tissue-type plasminogen activator activity. Changes of PAI-1 mRNA in various tissues were detected by high-performance liquid chromatography after reverse transcription and polymerase chain reaction. Hemorrhage (20 ml/kg) significantly elevated plasma PAI activity at 0.5, 1, 2, 4, 6, and 8 h after hemorrhage and PAI-1 mRNA in liver at 1, 2, 4, and 6 h after hemorrhage. The PAI-1 message was also significantly elevated in lung, heart, and kidney at 4 h after hemorrhage. The increases of PAI-1 mRNA after 20 ml/kg hemorrhage were significantly greater than those after 15 ml/kg hemorrhage. These findings indicate that large hemorrhage can induce the increases in PAI activity and PAI-1 message and suggest that induction of PAI-1 may be involved in the thrombogenic responses observed after large hemorrhage.

scholarly journals Spironolactone Abolishes the Relationship between Aldosterone and Plasminogen Activator Inhibitor-1 in Humans

2002 ◽  
Vol 87 (2) ◽  
pp. 448-452 ◽  
Author(s):  
Pairunyar Sawathiparnich ◽  
Sandeep Kumar ◽  
Douglas E. Vaughan ◽  
Nancy J. Brown
Keyword(s):  
Angiotensin Ii ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type Plasminogen Activator ◽  
Serum Aldosterone ◽  
The Relationship ◽  
Activator Inhibitor ◽  
Pai 1

Recent studies have defined a link between the renin-angiotensin-aldosterone system and fibrinolysis. The present study tests the hypothesis that endogenous aldosterone regulates plasminogen activator inhibitor-1 (PAI-1) production in humans. Hemodynamic parameters, PAI-1 and tissue-type plasminogen activator (t-PA) antigen, potassium, PRA, angiotensin II, and aldosterone were measured in nine male hypertensive subjects after a 3-wk washout, after 2 wk of hydrochlorothiazide (HCTZ; 25 mg plus 20 mmol KCl/d), and after 2 wk of spironolactone (100 mg/d plus KCl placebo). Spironolactone (P = 0.04), but not HCTZ (P = 0.57 vs. baseline; P = 0.1 vs. spironolactone), significantly lowered systolic blood pressure. Angiotensin II increased from baseline during both HCTZ (P = 0.02) and spironolactone (P = 0.02 vs. baseline; P = 0.19 vs. HCTZ) treatments. Although both HCTZ (P = 0.004) and spironolactone (P < 0.001 vs. baseline) increased aldosterone, the effect was greater with spironolactone (P < 0.001 vs. HCTZ). HCTZ increased PAI-1 antigen (P = 0.02), but did not alter t-PA antigen. In contrast, there was no effect of spironolactone on PAI-1 antigen (P = 0.28), whereas t-PA antigen was increased (P = 0.01). There was a significant correlation between PAI-1 antigen and serum aldosterone during both baseline and HCTZ study days (r2 = 0.57; P = 0.0003); however, treatment with spironolactone abolished this correlation (r2 = 0.13; P = 0.33). This study provides evidence that endogenous aldosterone influences PAI-1 production in humans.

scholarly journals Cell-Free mRNA Concentrations of Plasminogen Activator Inhibitor-1 and Tissue-Type Plasminogen Activator Are Increased in the Plasma of Pregnant Women with Preeclampsia

2007 ◽  
Vol 53 (3) ◽  
pp. 399-404 ◽  
Author(s):  
Yuditiya Purwosunu ◽  
Akihiko Sekizawa ◽  
Keiko Koide ◽  
Antonio Farina ◽  
Noroyono Wibowo ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Maternal Plasma ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Background: Detection of placental mRNA in maternal plasma has been reported in high-risk pregnancies. We attempted to investigate the concentrations of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) mRNA in maternal plasma in preeclampsia. Methods: Peripheral blood samples were obtained from healthy pregnant women before and after delivery and also from women with or without preeclampsia. Plasma was isolated from these samples, and RNA was extracted. Plasma PAI-1 and tPA mRNA concentrations were then measured by use of reverse transcription PCR assays. The concentrations were converted into multiples of the median (MoM) of the controls adjusted for gestational age. Data were stratified and analyzed according to the clinical severity of preeclampsia and quantitative distribution of blood pressure and proteinuria. Results: The median (minimum–maximum) PAI-1 mRNA MoM values for women with preeclampsia and controls were 2.48 (0.82–8.53) and 1.00 (0.41–2.33), respectively, whereas the median (minimum–maximum) tPA mRNA MoM values were 3.33 (1.01–10.58) and 1.00 (0.95–1.20), respectively. The concentrations of both PAI-1 and tPA mRNA were significantly increased in cases of preeclampsia, compared with controls (P <0.0001). The MoM values of both mRNA species were directly correlated with the severity of preeclampsia and were greatest among a subgroup of hemolysis, increased liver enzymes, and low platelets pregnancies. Conclusion: Maternal plasma PAI-1 and tPA mRNAs are significantly increased in patients with preeclampsia and are positively correlated with the severity of preeclampsia.

The Role of the Finger Domain of Tissue-type Plasminogen Activator (t-PA) and Plasminogen Activator Inhibitor 1 (PAI-1) in Initiation and Progression of Thrombolysis

1994 ◽  
Vol 72 (06) ◽  
pp. 900-905 ◽  
Author(s):  
Harold A R Stringer ◽  
Peter van Swieten ◽  
Anton J G Horrevoets ◽  
Annelies Smilde ◽  
Hans Pannekoek
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Clot Lysis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor ◽  
Pai 1

SummaryWe further investigated the role of the finger (F) and the kringle-2 (K2) domains of tissue-type plasminogen activator (t-PA) in fibrin-stimulated plasminogen activation. To that end, the action of purified (wt) t-PA or of variants lacking F (del.F) or K2 (del.K2) was assessed either in a static, human whole blood clot-lysis system or in whole blood thrombi generated in the “Chandler loop”. In both clot-lysis systems, significant differences were observed for the initiation of thrombolysis with equimolar concentrations of the t-PA variants. A relatively minor “lag phase” occurred in thrombolysis mediated by wt t-PA, whereas a 6.4-fold and 1.6-fold extension is found for del.F and del.K2, respectively. We observed identical lag-times, characteristic for each t-PA variant, in platelet-rich heads and in platelet-poor tails of thrombi. Since plasminogen activator inhibitor 1 (PAI-1) is preferentially retained in the platelet-rich heads, we conclude that the inhibitor does not interfere with the initial stage of thrombolysis but exerts its action in later stages, resulting in a reduction of the rate of clot lysis. A complementation clot-lysis assay was devised to study a potential interplay of del.F and del.K2. Accordingly, clot lysis was determined with combinations of del.F and del.K2 that were inversely varied in relation to equipotent dosage to distinguish between additive, antagonistic or synergistic effects of these variants. The isobole for combinations of del.F and del.K2 shows an independent, additive action of del.F and del.K2 in clot lysis. Under the conditions employed, namely a relatively high concentration of fibrin and Glu-plasminogen and a low concentration of t-PA variant, our data show: i) the crucial role of the F domain and the lack of effect of PAI-1 in initiation of thrombolysis, ii) the lack of importance of the fibrimbinding domains of t-PA and the regulatory role of PAI-1 in advanced stages of thrombolysis.

scholarly journals Functional Stability of Plasminogen Activator Inhibitor-1

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Songul Yasar Yildiz ◽  
Pinar Kuru ◽  
Ebru Toksoy Oner ◽  
Mehmet Agirbasli
Keyword(s):  
Plasminogen Activator ◽  
Biological Effects ◽  
Critical Role ◽  
Plasma Concentrations ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor ◽  
Pai 1

Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), and a major regulator of the fibrinolytic system. PAI-1 plays a pivotal role in acute thrombotic events such as deep vein thrombosis (DVT) and myocardial infarction (MI). The biological effects of PAI-1 extend far beyond thrombosis including its critical role in fibrotic disorders, atherosclerosis, renal and pulmonary fibrosis, type-2 diabetes, and cancer. The conversion of PAI-1 from the active to the latent conformation appears to be unique among serpins in that it occurs spontaneously at a relatively rapid rate. Latency transition is believed to represent a regulatory mechanism, reducing the risk of thrombosis from a prolonged antifibrinolytic action of PAI-1. Thus, relying solely on plasma concentrations of PAI-1 without assessing its function may be misleading in interpreting the role of PAI-1 in many complex diseases. Environmental conditions, interaction with other proteins, mutations, and glycosylation are the main factors that have a significant impact on the stability of the PAI-1 structure. This review provides an overview on the current knowledge on PAI-1 especially importance of PAI-1 level and stability and highlights the potential use of PAI-1 inhibitors for treating cardiovascular disease.

Role of viral receptors TLR3, RIG-I and MDA5 in mesothelial tissue-type plasminogen activator and plasminogen activator inhibitor-1 synthesis

2009 ◽  
Vol 101 (06) ◽  
pp. 1128-1137 ◽  
Author(s):  
Matthias Sauter ◽  
Kathrin Kastenmüller ◽  
Andrea Ribeiro ◽  
Thomas Mussack ◽  
Roland Ladurner ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Viral Infections ◽  
Plasminogen Activator Inhibitor ◽  
Poly I:C ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type Plasminogen Activator ◽  
Viral Receptors ◽  
Activator Inhibitor ◽  
Pai 1

SummaryTissue-type plasminogen activator (t-PA) and its specific inhibitor plasminogen activator inhibitor-1 (PAI-1) are key mediators in the regulation of fibrin generation and fibrinolysis. Mesothelial cells (MC) line the inner surface of serosal cavities and are a source of procoagulant and fibrinolytic system components. Viral inflammation and infection of MC are a major problem in several organ systems including pleura, pericardium and peritoneum. MC express the viral receptors Toll-like receptor 3 (TLR3), RIG-I and MDA5. TLRs recognise molecular patterns associated with microbial pathogens and induce an immune response. TLR3 recognises dsRNA of viral origin as exemplified by poly (I:C) RNA, a synthetic analogue of viral dsRNA. The helicases RIG-I and MDA5 may also act as sensors of viral infections. Activation of these receptors by poly (I:C) RNA leads to an time- and dose-dependent increase of mesothelial PAI-1 synthesis and a decrease of t-PA expression. To show the specific effect of viral receptors knockdown experiments with siRNA specific for TLR3, RIG-I and MDA5 were performed. This finding of viral induced changes of t-PA and PAI-1 synthesis may indicate a novel link between viral infections and formation of mesothelial fibrin deposits and progression of viral associated disease of the pleura, peritoneum and pericardium.

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