Ex vivo Pulsatile Perfusion of Human Saphenous Veins Induces Intimal Hyperplasia and Increased Levels of the Plasminogen Activator Inhibitor 1

AbstractPatients with coronavirus disease-19 (COVID-19) are at high risk for thrombotic arterial and venous occlusions. However, bleeding complications have also been observed in some patients. Understanding the balance between coagulation and fibrinolysis will help inform optimal approaches to thrombosis prophylaxis and potential utility of fibrinolytic-targeted therapies. 118 hospitalized COVID-19 patients and 30 healthy controls were included in the study. We measured plasma antigen levels of tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) and performed spontaneous clot-lysis assays. We found markedly elevated tPA and PAI-1 levels in patients hospitalized with COVID-19. Both factors demonstrated strong correlations with neutrophil counts and markers of neutrophil activation. High levels of tPA and PAI-1 were associated with worse respiratory status. High levels of tPA, in particular, were strongly correlated with mortality and a significant enhancement in spontaneous ex vivo clot-lysis. While both tPA and PAI-1 are elevated among COVID-19 patients, extremely high levels of tPA enhance spontaneous fibrinolysis and are significantly associated with mortality in some patients. These data indicate that fibrinolytic homeostasis in COVID-19 is complex with a subset of patients expressing a balance of factors that may favor fibrinolysis. Further study of tPA as a biomarker is warranted.

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Abstract 188: Selective Inhibition of Vascular Smooth Muscle Cell Migration by Targeting Plasminogen Activator Inhibitor-1

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.35.suppl_1.188 ◽

2015 ◽

Vol 35 (suppl_1) ◽

Author(s):

Neha Goyal ◽

Zhen Weng ◽

Philip Fish ◽

Tammy Strawn ◽

Samantha Myears ◽

...

Keyword(s):

Smooth Muscle ◽

Cell Migration ◽

Plasminogen Activator ◽

Intimal Hyperplasia ◽

Differential Effect ◽

Plasminogen Activator Inhibitor ◽

Dependent Manner ◽

Plasminogen Activator Inhibitor 1 ◽

Activator Inhibitor ◽

Pai 1

Introduction: Plasminogen activator inhibitor-1 (PAI-1) is the primary inhibitor of mammalian plasminogen activators and an important regulator of cell migration. We have shown that tiplaxtinin, a small molecule, specific inhibitor of PAI-1, inhibits intimal hyperplasia in a murine vein graft model. However, little is known about the effects of pharmacological inhibition of PAI-1 on vascular cell migration under physiologically relevant conditions. Methods: We studied the effects of tiplaxtinin on migration of smooth muscle cells (SMCs) and endothelial cells (ECs). Results: Tiplaxtinin significantly inhibited migration of murine SMCs through 3-dimensional (3-D) collagen matrix in a concentration-dependent manner. Tiplaxtinin did not inhibit SMC proliferation, and it did not inhibit migration of PAI-1-deficient SMCs, suggesting that tiplaxtinin’s effect on SMCs was non-toxic and PAI-1-dependent. The anti-migratory effect of tiplaxtinin on SMCs was preserved in collagen 3-D matrix containing vitronectin and other extracellular matrix molecules, further supporting the physiological significance of the effect. In contrast to SMCs, tiplaxtinin did not inhibit migration of human aortic ECs in vitro or murine ECs in vivo, the latter assessed in a murine carotid injury model. To study the basis for the differential effect of tiplaxtinin on SMCs vs. ECs, we compared expression of LDL receptor-related protein 1 (LRP1), a motogenic receptor for PAI-1, between cell types by RT-PCR and found that LRP1 gene expression was significantly lower in ECs than in SMCs. Furthermore, recombinant PAI-1 stimulated the migration of wild-type mouse embryonic fibroblasts (MEFs), but not LRP1-deficient MEFs. Conclusions: Tiplaxtinin, a pharmacological inhibitor of PAI-1, inhibits SMC migration under physiological conditions, while having no inhibitory effect on EC migration. The differential effect of PAI-1 inhibition on SMCs vs. ECs appears to be mediated by LRP1 and may be of clinical significance, as it is advantageous to prevent intimal hyperplasia by inhibiting SMC migration without inhibiting EC migration, which is key to preserving an intact, anti-thrombotic vascular endothelium.

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The Amount of Plasminogen, Tissue-Type Plasminogen Activator and Plasminogen Activator Inhibitor Type 1 in Human Thrombi and the Relation to IVVO-TNO Lysibility

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648388 ◽

1992 ◽

Vol 67 (01) ◽

pp. 101-105 ◽

Cited By ~ 71

Author(s):

B J Potter van Loon ◽

D C Rijken ◽

E J P Brommer ◽

A P C van der Maas

Keyword(s):

Plasminogen Activator ◽

Ex Vivo ◽

Plasminogen Activator Inhibitor ◽

Tissue Type ◽

Plasminogen Activator Inhibitor 1 ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator ◽

Activator Inhibitor ◽

Pai 1

SummaryThrombolytic therapy successfully reopens obstructed blood vessels in the majority of cases. However, it is not known why a substantial amount of thrombi are resistant to lysis by a fibrinolytic agent. In vitro studies have demonstrated that tissue-type plasminogen activator (t-PA) and plasminogen incorporated in the clot (during formation) increase lysibility. To test whether lysibility of in vivo formed human thrombi is related to their composition, we studied 25 venous thrombi obtained at autopsy and 21 arterial thrombi obtained during embolectomy.Plasminogen activator inhibitor-1 (PAI-1) antigen was measured in a phosphate-buffered saline (PBS) extract of each thrombus; t-PA antigen and plasminogen antigen were determined in a 6 M urea extract of the thrombus, representing bound proteins. Lysibility was measured as weight reduction during 8 h of incubation in PBS containing streptokinase (SK) 100 U/ml, corrected for spontaneous lysis, reflected by weight loss in PBS without SK. In addition, lysibility in SK was compared with lysibility in urokinase (UK) 100 U/ml and in t-PA 200 U/ml.Spontaneous lysis amounted to 29 ± 5% (mean ± SEM) and 33 ± 5% in venous and arterial thrombi, respectively, and inversely correlated with the PAI-1 content of thrombi (r = —0.43, p <0.01). Lysibility amounted to 76 ± 6% in venous and 90 ± 4% in arterial thrombi (venous vs. arterial: p = 0.051). PAI-1-, plasminogen- and t-PA-content of venous thrombi were 902 ± 129 ng, 34.3 ± 4.8 pg and 26.7 ± 3.0 ng per gram of wet thrombus respectively; for arterial thrombi these values were 2,031 ± 401 ng/g (p = 0.011), 64.1 ± 11.4 pg/g (p = 0.088) and 62.2 ± 8.3 ng/g (p = 0.0001), respectively. A correlation was found between t-PA and plasminogen (r = 0.74, p <0.001). Lysibility by SK related to plasminogen content in both venous (r = 0.60, p <0.002) and arterial (r = 0.44, p <0.05) thrombi; PAI-1 and t-PA did not correlate with lysibility. Lysibility in the chosen concentrations of SK, UK and t-PA were similar.We conclude that spontaneous lysis of thrombi in saline is dependent on PAI-1 content and that susceptibility of thrombibi to lysis by SK ex vivo is dependent on the plasminogen content

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Plasma tissue plasminogen activator and plasminogen activator inhibitor-1 in hospitalized COVID-19 patients

10.1101/2020.08.29.20184358 ◽

2020 ◽

Author(s):

Yu Zuo ◽

Mark Warnock ◽

Alyssa Harbaugh ◽

Srilakshmi Yalavarthi ◽

Kelsey Gockman ◽

...

Keyword(s):

Plasminogen Activator ◽

Ex Vivo ◽

Plasminogen Activator Inhibitor ◽

Tissue Type ◽

Bleeding Complications ◽

Clot Lysis ◽

Thrombosis Prophylaxis ◽

Plasminogen Activator Inhibitor 1 ◽

Activator Inhibitor ◽

Pai 1

ABSTRACTPatients with coronavirus disease-19 (COVID-19) are at high risk for thrombotic arterial and venous occlusions. However, bleeding complications have also been observed in some patients. Understanding the balance between coagulation and fibrinolysis will help inform optimal approaches to thrombosis prophylaxis and potential utility of fibrinolytic-targeted therapies. 118 hospitalized COVID-19 patients and 30 healthy controls were included in the study. We measured plasma antigen levels of tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) and performed spontaneous clot-lysis assays. We found markedly elevated tPA and PAI-1 levels in patients hospitalized with COVID-19. Both factors demonstrated strong correlations with neutrophil counts and markers of neutrophil activation. High levels of tPA and PAI-1 were associated with worse respiratory status. High levels of tPA, in particular, were strongly correlated with mortality and a significant enhancement in spontaneous ex vivo clot-lysis. While both tPA and PAI-1 are elevated among COVID-19 patients, extremely high levels of tPA enhance spontaneous fibrinolysis and are significantly associated with mortality in some patients. These data indicate that fibrinolytic homeostasis in COVID-19 is complex with a subset of patients expressing a balance of factors that may favor fibrinolysis. Further study of tPA as a biomarker is warranted.

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Recombinant Plasminogen Activator Inhibitor-1 Inhibits Intimal Hyperplasia

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.109.189514 ◽

2009 ◽

Vol 29 (10) ◽

pp. 1565-1570 ◽

Cited By ~ 20

Author(s):

Jianbo Wu ◽

Lin Peng ◽

Grainne A. McMahon ◽

Daniel A. Lawrence ◽

William P. Fay

Keyword(s):

Plasminogen Activator ◽

Intimal Hyperplasia ◽

Plasminogen Activator Inhibitor ◽

Plasminogen Activator Inhibitor 1 ◽

Activator Inhibitor

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943: Plasminogen Activator Inhibitor 1 (PAI-1) is Increased in Human Peyronie's Disease

The Journal of Urology ◽

10.1016/s0022-5347(18)35099-7 ◽

2005 ◽

Vol 173 (4S) ◽

pp. 255-255 ◽

Cited By ~ 1

Author(s):

Hugo H. Davila ◽

Thomas R. Magee ◽

Freddy Zuniga ◽

Jacob Rajfer ◽

Nestor F. GonzalezCadavid

Keyword(s):

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Peyronie’S Disease ◽

Plasminogen Activator Inhibitor 1 ◽

Peyronie's Disease ◽

Activator Inhibitor ◽

Pai 1

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Relationship of Plasminogen Activator Inhibitor-1 Levels following Thrombolytic Therapy with rt-PA as Compared to Streptokinase and Patency of Infarct Related Coronary Artery

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614637 ◽

1999 ◽

Vol 82 (07) ◽

pp. 104-108 ◽

Cited By ~ 13

Author(s):

Franck Paganelli ◽

Marie Christine Alessi ◽

Pierre Morange ◽

Jean Michel Maixent ◽

Samuel Lévy ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Thrombolytic Therapy ◽

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Control Group ◽

Plasminogen Activator Inhibitor 1 ◽

Vessel Patency ◽

Activator Inhibitor ◽

Pai 1

Summary Background: Type 1 plasminogen activator inhibitor (PAI-1) is considered to be risk factor for acute myocardial infarction (AMI). A rebound of circulating PAI-1 has been reported after rt-PA administration. We investigated the relationships between PAI-1 levels before and after thrombolytic therapy with streptokinase (SK) as compared to rt-PA and the patency of infarct-related arteries. Methods and Results: Fifty five consecutive patients with acute MI were randomized to strep-tokinase or rt-PA. The plasma PAI-1 levels were studied before and serially within 24 h after thrombolytic administration. Vessel patency was assessed by an angiogram at 5 ± 1days. The PAI-1 levels increased significantly with both rt-PA and SK as shown by the levels obtained from a control group of 10 patients treated with coronary angioplasty alone. However, the area under the PAI-1 curve was significantly higher with SK than with rt-PA (p <0.01) and the plasma PAI-1 levels peaked later with SK than with rt-PA (18 h versus 3 h respectively). Conversely to PAI-1 levels on admission, the PAI-1 levels after thrombolysis were related to vessel patency. Plasma PAI-1 levels 6 and 18 h after SK therapy and the area under the PAI-1 curve were significantly higher in patients with occluded arteries (p <0.002, p <0.04 and p <0.05 respectively).The same tendency was observed in the t-PA group without reaching significance. Conclusions: This study showed that the PAI-1 level increase is more pronounced after SK treatment than after t-PA treatment. There is a relationship between increased PAI-1 levels after thrombolytic therapy and poor patency. Therapeutic approaches aimed at quenching PAI-1 activity after thrombolysis might be of interest to improve the efficacy of thrombolytic therapy for acute myocardial infarction.

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Fibrinolysis in Normal Subjects - Comparison Between Plasminogen Activator Inhibitor and Other Components of the Fibrinolytic System

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642775 ◽

1988 ◽

Vol 59 (02) ◽

pp. 299-303 ◽

Cited By ~ 40

Author(s):

Grazia Nicoloso ◽

Jacques Hauert ◽

Egbert K O Kruithof ◽

Guy Van Melle ◽

Fedor Bachmann

Keyword(s):

Plasminogen Activator ◽

Fibrinolytic Activity ◽

Plasminogen Activator Inhibitor ◽

Venous Occlusion ◽

Venous Stasis ◽

Plasminogen Activator Inhibitor 1 ◽

Plate Assay ◽

Fibrin Plate ◽

Activator Inhibitor ◽

Pai 1

SummaryWe analyzed fibrinolytic parameters in 20 healthy men and 20 healthy women, aged from 25 to 59, before and after 10 and 20 min venous occlusion. The 10 min post-occlusion fibrinolytic activity measured directly in diluted unfractionated plasma by a highly sensitive 125I-fibrin plate assay correlated well with the activity of euglobulins determined by the classical fibrin plate assay (r = 0.729), but pre-stasis activities determined with these two methods did not correlate (r = 0.084). The enhancement of fibrinolytic activity after venous occlusion was mainly due to an increase of t-PA in the occluded vessels (4-fold increase t-PA antigen after 10 min and 8-fold after 20 min venous occlusion). Plasminogen activator inhibitor (PAI) activity and plasminogen activator inhibitor 1 (PAI-1)1 antigen levels at rest showed considerable dispersion ranging from 1.9 to 12.4 U/ml, respectively 6.9 to 77 ng/ml. A significant increase of PAI-1 antigen levels was observed after 10 and 20 min venous occlusion. At rest no correlation was found between PAI activity or PAI-1 antigen levels and the fibrinolytic activity measured by 125I-FPA. However, a high level of PAI-1 at rest was associated with a high prestasis antigen level of t-PA and a low fibrinolytic response after 10 min of venous stasis. Since the fibrinolytic response inversely correlated with PAI activity at rest, we conclude that its degree depends mainly on the presence of free PAI.

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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

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646305 ◽

1992 ◽

Vol 68 (05) ◽

pp. 486-494 ◽

Cited By ~ 15

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.

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Relation between Plasminogen Activator Inhibitor-1 and Hepatic Enzyme Concentrations in Hyperlipidemic Patients

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648885 ◽

1994 ◽

Vol 72 (03) ◽

pp. 434-437 ◽

Cited By ~ 10

Author(s):

E Bruckert ◽

A Ankri ◽

P Glral ◽

G Turpin

Keyword(s):

Blood Pressure ◽

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Tolerance Test ◽

High Plasma ◽

Oral Glucose ◽

Plasminogen Activator Inhibitor 1 ◽

Glutamyl Transferase ◽

Activator Inhibitor ◽

Pai 1

SummaryPlasminogen activator inhibitor type-1 (PAI-1) is a key determinant of the fibrinolytic capacity. Its activity correlates with most of the characteristic features of insulin resistance syndrome, i. e. obesity, high blood pressure and hyperlipidemia.We measured plasma PAI-1 antigen levels in 131 asymptomatic men (aged 44.2 ± 11 years) who had been referred for hyperlipidemia. Those taking medication and those with a secondary hyperlipidemia were excluded.We confirmed the correlation between PAI-1 levels and the following variables: body mass index, blood pressure, triglyceride concentration, and blood glucose and insulin levels before and after an oral glucose tolerance test. We also found a significant and independent correlation between PAI-1 and the concentration of the hepatic enzymes glutamyl transferase, alanine aminotransferase and aspartate aminotransferase.Mild liver abnormalities (presumably steatosis) may thus be one of the factors accounting for high plasma PAI-1 levels in hyperlipidemic patients.

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