Faculty Opinions recommendation of Plasminogen activator inhibitor-1 supports IL-8-mediated neutrophil transendothelial migration by inhibition of the constitutive shedding of endothelial IL-8/heparan sulfate/syndecan-1 complexes.

Author(s):  
Anne Woods Couchman
Endocrinology ◽  
1997 ◽  
Vol 138 (7) ◽  
pp. 2972-2978 ◽  
Author(s):  
Taek Jeong Nam ◽  
Walker Busby ◽  
David R. Clemmons

Abstract Insulin-like growth factor binding protein-5 (IGFBP-5) has been shown to bind to the extracellular matrix (ECM) of both fibroblasts and smooth muscle cells. The ECM-IGFBP-5 interaction is mediated in part by binding to heparan sulfate containing proteoglycans. Because proteoglycans may not be the only components of ECM that bind to IGFBP-5, we have determined its ability to bind to other ECM proteins. When a partially purified mixture of the proteins that were present in fibroblast conditioned medium was purified by IGFBP-5 affinity chromatography, a 55-kDa protein was eluted. Amino acid sequencing of the amino terminal 28 amino acids showed that it was human plasminogen activator inhibitor-1 (PAI-1). To determine if this interaction was specific, purified human PAI-1 was incubated with IGFBP-5 and the IGFBP-5/PAI-1 complex immunoprecipitated with anti-PAI-1 antiserum. When the precipitate was analyzed by immunoblotting using anti-IGFBP-5 antiserum, the intensity of the IGFBP-5 band was substantially increased compared with controls that did not contain human PAI-1. A synthetic IGFBP-5 peptide that contained the amino acid sequence between positions 201 and 218 inhibited IGFBP-5/PAI-1 interaction. Coincubation of IGFBP-5 mutants that contained substitutions for specific basic residues located between positions 201 and 218 with PAI-1 indicated that some of these amino acids were important for binding. Two mutants that contained neutral substitutions for specific basic amino acids within the glycosaminoglycan binding domain had reduced binding to PAI-1. In contrast, three other mutants that also had substitutions for charged residues in the same region had no reduction in binding. Heparin and heparan sulfate inhibited the IGFBP-5/PAI-1 interaction; however, several other glycosaminoglycans had no effect. PAI-1 was determined to be an important ECM component for binding because approximately 27% of total ECM binding could be inhibited with anti-PAI-1 antiserum. Competitive binding studies with unlabeled IGFBP-5 showed that the dissociation constant of PAI-1 for IGFBP-5 was 9.1 × 10−8m. In summary, IGFBP-5 binds specifically to plasminogen activator inhibitor-1. Because this is present in the extracellular matrix of several cell types, it may be one of the important binding components of ECM. PAI-1 binding partially protects IGFBP-5 from proteolysis, suggesting that it is one of the ECM components that is involved in mediating this effect.


2005 ◽  
Vol 173 (4S) ◽  
pp. 255-255 ◽  
Author(s):  
Hugo H. Davila ◽  
Thomas R. Magee ◽  
Freddy Zuniga ◽  
Jacob Rajfer ◽  
Nestor F. GonzalezCadavid

1999 ◽  
Vol 82 (07) ◽  
pp. 104-108 ◽  
Author(s):  
Franck Paganelli ◽  
Marie Christine Alessi ◽  
Pierre Morange ◽  
Jean Michel Maixent ◽  
Samuel Lévy ◽  
...  

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.


1988 ◽  
Vol 59 (02) ◽  
pp. 299-303 ◽  
Author(s):  
Grazia Nicoloso ◽  
Jacques Hauert ◽  
Egbert K O Kruithof ◽  
Guy Van Melle ◽  
Fedor Bachmann

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.


1992 ◽  
Vol 68 (05) ◽  
pp. 486-494 ◽  
Author(s):  
Malou Philips ◽  
Anne-Grethe Juul ◽  
Johan Selmer ◽  
Bent Lind ◽  
Sixtus Thorsen

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.


1994 ◽  
Vol 72 (03) ◽  
pp. 434-437 ◽  
Author(s):  
E Bruckert ◽  
A Ankri ◽  
P Glral ◽  
G Turpin

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.


1993 ◽  
Vol 70 (02) ◽  
pp. 301-306 ◽  
Author(s):  
Linda A Robbie ◽  
Nuala A Booth ◽  
Alison M Croll ◽  
Bruce Bennett

SummaryThe relative importance of the two major inhibitors of fibrinolysis, α2-antiplasmin (α2-AP) and plasminogen activator inhibitor (PAI-1), were investigated using a simple microtitre plate system to study fibrin clot lysis in vitro. Cross-linked fibrin clots contained plasminogen and tissue plasminogen activator (t-PA) at concentrations close to physiological. Purified α2-AP and PAI-1 caused dose-dependent inhibition. All the inhibition due to normal plasma, either platelet-rich or poor, was neutralised only by antibodies to α2-AP. Isolated platelets, at a final concentration similar to that in blood, 2.5 × 108/ml, markedly inhibited clot lysis. This inhibition was neutralised only by antibodies to PAI-1. At the normal circulating ratio of plasma to platelets, α2-AP was the dominant inhibitor. When the platelet:plasma ratio was raised some 20-fold, platelet PAI-1 provided a significant contribution. High local concentrations of PAI-1 do occur in thrombi in vivo, indicating a role for PAI-1, complementary to that of α2-AP, in such situations.


1995 ◽  
Vol 73 (02) ◽  
pp. 261-267 ◽  
Author(s):  
Rosaire P Gray ◽  
Vidya Mohamed-Ali ◽  
David L H Patterson ◽  
John S Yudkin

SummaryA significant relationship has been described between plasminogen activator inhibitor-1 (PAI-1) and plasma insulin concentrations. However, most radioimmunoassays (RIA) substantially overestimate plasma insulin concentrations because of cross reaction with proinsulin-like molecules and it has been proposed that proinsulin-like molecules may be important determinants of PAI-1 activity. We measured fasting plasma immunoreactive insulin by conventional RIA, fasting plasma insulin (EIMA) by specific two site immuno-enzymometric assay, and intact proinsulin and des-31,32-proinsulin by two site immunoradiometric assay (IRMA) in 74 (50 nondiabetic and 24 diabetic) subjects who had survived a myocardial infarction between 6 and 24 months previously. In univariate analysis, PAI-1 activity correlated with serum triglycerides (rs=0.43; p <0.0001), insulin sensitivity (rs = -0.30; p = 0.004), and immunoreactive insulin (rs = 0.45; p <0.0001). However, the relationship between PAI-1 activity and plasma specific insulin (IEMA) was weaker (rs = 0.24; p = 0.019) than those with intact proinsulin (rs = 0.53; p <0.0001) and des-31,32-proinsulin (rs = 0.54; p <0.0001) despite the low concentrations of these proinsulin-like molecules. In multiple regression analysis, only des-31,32-proinsulin (p = 0.001) and serum triglycerides (p = 0.013) were significant determinants of PAI-1 activity. In conclusion, these results suggest that proinsulin-like molecules and serum triglycerides are important determinants of PAI-1 activity in survivors of myocardial infarction.


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