Abstract 267: A Single Dose of Reconstituted High Density Lipoprotein Reduces Expression of Tissue-Factor In Human Carotid Atherosclerotic Plaques

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hosaam H Nasr ◽  
Ian M Loftus ◽  
Saiqa Sayed ◽  
Alun Jones ◽  
Evelyn Torsney ◽  
...  

Background: Multiple infusions of HDLs have been shown to mediate approximately 4% reduction in plaque volume. This may relate to removal of intra-plaque lipid, but the precise mechanism is unknown. To test the hypothesis that HDLs may influence plaque stabilisation through modulating transcription, we examined the effects of a single dose of rHDL on expression of thrombomodulatory genes in carotid plaques. Materials and Methods: Forty patients undergoing carotid endarterectomy (CEA) were stratified to three groups: early symptomatics ( n =12, stroke/transient ischemic attack (TIA) 1month before CEA)late symptomatics ( n =14, stroke/TIA > 1month before CEA); and asymptomatics ( n =12). RNA was isolated from plaques following CEA, and expression of the thrombomodulatory genes, tissue factor (TF); tissue factor pathway inhibitor (TFPI); thrombomodulin (TM); tissue type plasminogen activator (tPA); urokinase plasminogen activator (uPA); plasminogen activator inhibitor-1 (PAI-1), measured using QRT-RT-PCR. Nine patients with early symptomatic carotid disease, undergoing CEA, were then randomised to infusion of reconstituted HDL (rHDL) 80mg/kg Apo A-I ( n =4) or a similar volume of phosphate buffered saline ( n =5). Plaque specimens were collected 24 hrs later and RNA isolated for QRT-RT- PCR measurement of thrombomodulatory gene expression. Results: A significant difference in TF, TM, tPA and PAI-1 genes were observed in the 3 patient groups (see Table 1 ). In the rHDL group, a single dose of rHDL reduced the expression of TF (0.71 (0.65–0.75) vs 0.98 (0.81–1.14), P=0.05). No significant difference was observed in other thrombomodulatory factors between the 2 groups. Conclusions: Plaque stabilisation, which occurs within one month of a clinical event may be facilitated, at the transcriptional level, following rHDL infusion. We hope to report a larger double blind placebo controlled trial which will determine the full effects of rHDLs on plaque stability. Table 1

1999 ◽  
Vol 82 (11) ◽  
pp. 1497-1503 ◽  
Author(s):  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Haruchika Masuda ◽  
Yasushi Kunieda ◽  
Hidehiko Kawano ◽  
...  

SummaryIn the present study, we demonstrate that brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) interact with angiotensin II (Ang II) in regulative blood coagulation and fibrinolysis by suppressing the expressions of both tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) induced by Ang II. The expressions of TF and PAI-1 mRNA were analyzed by northern blotting methods, and the activities of TF on the surface of rat aortic endothelial cells (RAECs) and PAI-1 in the culture media were respectively measured by chromogenic assay.Both BNP and CNP suppressed the expressions of TF and PAI-1 mRNA induced by Ang II in a time- and concentration-dependent manner via cGMP cascade, which suppressions were accompanied by respective decrease in activities of TF and PAI-1. However, neither the expression of tissue factor pathway inhibitor (TFPI) nor tissue-type plasminogen activator (TPA) mRNA was affected by the treatment of BNP and CNP.


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.


1998 ◽  
Vol 79 (03) ◽  
pp. 587-590 ◽  
Author(s):  
J. A. Cooper ◽  
D. J. Howarth ◽  
T. W. Meade ◽  
G. J. Miller ◽  
P. K. MacCallum

SummaryImpaired whole blood fibrinolytic activity (FA), measured by the dilute clot lysis time (DCLT), is associated with first episodes of ischaemic heart disease (IHD) in the Northwick Park Heart Study in men, especially under 55 years, and in women. In a community-based study to investigate possible determinants of the DCLT, and therefore to assess which fibrinolytic components might be predictors of first IHD events, we measured fibrinolytic variables in a sub-sample of 150 healthy adults (73 males, 77 females) randomly selected from a single general practice.Most of the variance in DCLT (68% in men, 63% in women) was explained by tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) activities. In multiple regression analysis there was a significant difference in the strength of the association of t-PA activity with DCLT in men compared to women (test for interaction p = 0.05), the association of t-PA activity with DCLT being significant in males but not in females. Plasma PAI-1 activity was strongly associated with DCLT in both sexes. There was no independent association of DCLT with plasma fibrinogen, t-PA antigen, other fibrinolytic inhibitors, body mass index, serum lipids or C-reactive protein.Plasma PAI-1 activity in females and both t-PA and PAI-1 activities in males are the main determinants of whole blood FA measured by DCLT. It is therefore likely that these modulators of the plasma fibrinolytic system are associated with the onset of first clinical episodes of IHD. Elevated levels of t-PA antigen were positively associated with DCLT after adjustment for age and sex and therefore indicate impaired rather than enhanced FA. Further studies of the association of FA with risk of IHD should include not only “global” measures but also assessment of t-PA and PAI-1 activities, particularly as our results suggest that their associations with IHD may differ in men and women.


2016 ◽  
Vol 8 (02) ◽  
pp. 101-105 ◽  
Author(s):  
Suheyla Gorar ◽  
Bulent Alioglu ◽  
Esranur Ademoglu ◽  
Seyit Uyar ◽  
Handan Bekdemir ◽  
...  

ABSTRACT Context: Impact of gestational diabetes mellitus (GDM) on the coagulation system, dynamics involved at a pathophysiological level and the exact mechanism remain unclear. Aims: To evaluate the association between diabetes-related parameters and hemostatic factors to search for a tendency of thrombosis in GDM. Settings and Design: Nineteen pregnant women who had GDM, 16 healthy pregnant and 13 healthy nonpregnant controls admitted to the Endocrinology outpatient clinics were enrolled in the study. Subjects and Methods: Fasting and postprandial glucose, hemoglobin A1c and insulin levels, and insulin resistance; fructosamine, thrombin activatable fibrinolysis inhibitor (TAFI), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor Type-1 (PAI-1), tissue-type plasminogen activator (t-PA), fibrinogen, plasminogen and hemoglobin levels, platelet counts, prothrombin time (PT), and activated partial thromboplastin time (aPTT) were studied. Statistical Analysis Used: One-way analysis of variance, Kruskal–Wallis, and post hoc Tukey honestly significant difference or Conover’s nonparametric multiple comparison tests for comparison of the study groups. Results: PT and aPTT were significantly lower in GDM patients compared to controls (P < 0.05), whereas fibrinogen and plasminogen levels were significantly higher in this group compared to both nonpregnant and healthy pregnant controls (P < 0.05 for each). TAFI, TFPI, PAI-1, and tissue t-PA levels were not significantly different among groups. Conclusions: Our findings indicate tendency to develop thrombosis in GDM similar to diabetes mellitus; but more comprehensive studies with larger sample size are needed to determine the relationship between GDM and hemostasis.


2007 ◽  
Vol 98 (10) ◽  
pp. 871-882 ◽  
Author(s):  
Kun Zhu ◽  
Mika Skeppholm ◽  
Jenny Vedin ◽  
Jan Svensson ◽  
Nils Egberg ◽  
...  

SummaryThe global assay of Overall Haemostasis Potential we previously described has been refined. The coagulation cascade in plateletpoor plasma is triggered by adding a minimal dose of recombinant tissue factor together with purified phospholipids and calcium; fibrinolysis is initiated by adding recombinant tissue type-plasminogen activator in a concentration similar to what can be obtained during thrombolysis. Numerical differentials of optical densities reflecting rates of fibrin formation and degradation are calculated by a new software, and the Coagulation Profile (Cp) and the Fibrinolysis Profile (Fp) are determined. The combined effect of these counteractive systems is expressed as a ratio of Cp to Fp, called the Overall Haemostasis Index. Commercially available coagulant-deficient patient plasma samples and plasma with various amounts of added PAI-1 are examined; changes of fibrin turbidity demonstrate that this assay can determine Cp and Fp in a physiologically relevant way. Increased Cp and decreased Fp in prothrombotic patients, as well as expected effects of heparin or a thrombin inhibitor on Cp and Fp, suggest that our method can detect hypercoagulability and assist in monitoring antithrombotic treatment. Ongoing studies will show whether this simple assay can be of value in clinical routine.


1997 ◽  
Vol 77 (06) ◽  
pp. 1189-1195 ◽  
Author(s):  
Hiromi Nishimura ◽  
Hajime Tsuji ◽  
Haruchika Masuda ◽  
Katsumi Nakagawa ◽  
Yoshihumi Nakahara ◽  
...  

SummaryAngiotensin converting enzyme inhibitors (ACE-I) have been reported to prevent the recurrence of cardiovascular events. The mechanism of this decrease, however, can not be completely explained by anti-hypertensive and anti-hypertrophic effects of ACE-I. To investigate the mechanism of this decrease, we studied the regulation of plasminogen activator inhibitor-1 (PAI-1), tissue type plasminogen activator (TPA), tissue factor (TF), and tissue factor pathway inhibitor (TFPI) by angiotensin II (Ang II) in cultured rat aortic endothelial cells. Ang II increased PAI-1 and TF mRNA expression without affecting that of TPA or TFPI. These inductions were accompanied by increases in PAI-1 and TF activities and were inhibited by a type 1 Ang II receptor antagonist. The results suggest that Ang II decreases the antithrombotic properties of endothelial cells which increases the chance of thrombosis. Thus, inhibition of the renin-angiotensin system may be beneficial to prevent thrombus formation in treatment of ischemic heart disease.


2009 ◽  
Vol 101 (04) ◽  
pp. 734-740 ◽  
Author(s):  
Nadine Ajzenberg ◽  
Laurent Feldman ◽  
Marie-Claude Guillin ◽  
Philippe Gabriel Steg ◽  
Marie-Geneviève Huisse

SummaryFibrinolysis for acute ST-segment elevation MI achieves early recanalisation of the infarct artery in approximately 60% of cases. The aim of the study was to determine whether failure to achieve recanalisation was associated with differences in haemostasis biomarkers compared to patients with successful fibrinolysis. Fourty-three patients were prospectively enrolled in a case-control study. All patients had received tenecteplase (TNKtPA) together with aspirin (500 mg) and heparin (5,000 IU). Emergency angiography within 90 minutes of bolus TNK-tPA identified 13 TIMI 0–2 patients (cases) and 30 TIMI 3 patients (controls). Blood samples were collected before angiography to determine tissue factor activity associated with microparticles (TF-MP); soluble platelet glycoprotein V (sGPV) and thrombinantithrombin complexes (TAT) as markers of thrombin generation; tissue plasminogen activator (endogenous tPA+ TNKtPA), plasminogen activator inhibitor (PAI-1) and plasmin-anti-plasmin complexes (PAP) as markers of plasmin generation. The baseline characteristics of the two patients’ groups were similar with respect to sex, age, and risks factors. Cases differed from controls by higher TF-MP levels (1.9 [1–13] vs. 1 [0.6–1.3] pM), sGPV (67 [51–126] vs. (48 [39–72] ng/ml), p=0.039 and TAT (10 [4–37.5] vs. 4 [2.9–7.2] ng/ml), p=0.035. TAT correlated with TF-MP (r=0.51, p=0.0064) and sGPV (r=0.51, p=0.0018). No significant difference was observed in tPA or PAI-1 levels. PAP were lower in cases (18.83 [14.83–40.43] μg/ml) than in controls (35.83 [27.9–43.94] μg/ml), p=0.045. In conclusion, fibrinolysis failure in AMI is characterised by a higher procoagulant state associated with TF-MP and a lower plasmin generation.


1994 ◽  
Vol 72 (01) ◽  
pp. 054-057 ◽  
Author(s):  
N Semeraro ◽  
P Montemurro ◽  
P Giordano ◽  
N Santoro ◽  
D De Mattia ◽  
...  

SummaryBlood clotting activation and fibrin deposition are common findings in lymphoma patients. We evaluated the capacity of peripheral blood mononuclear cells to produce procoagulant activity (PCA) and plasminogen activator inhibitor (PAI) in 12 children with newly diagnosed lymphoma (8 non-Hodgkin’s, 4 Hodgkin’s) and in 12 matched healthy donors. In the same subjects we also measured plasma antigen levels of tissue-type PA (t-PA), urokinase-type PA (u-PA), PAI-1, PAI-2, and D-dimer. PCA generated by mononuclear cells after incubation for 20 h at 37° C was significantly higher in patients than in controls (p = 0.027). In all samples it was identified as tissue factor by functional criteria (dependence on factor VII). Moreover, culture medium obtained from patients’ mononuclear cells after incubation for 20 h at 37° C contained significantly higher amounts of PAI activity and PAI-2 antigen than control samples (p <0.001). Plasma PAI-1 and t-PA antigens were significantly augmented in patients (p <0.005), the mean increase of PAI-I being about 5 times higher than that of t-PA. Plasma levels of D-dimer wete markedly increased in the patients’ group (p <0.001), whereas u-PA and PAI-2 antigens did not differ from controls. It is suggested that monocytes from lymphoma patients are endowed with functional abnormalities leading to the simultaneous expression of tissue factor and antifibrinolytic activity. These abnormalities, coupled with a reduced plasma fibrinolytic potential, could play an important pathogenetic role in blood clotting activation and fibrin deposition associated with lymphoma.


1999 ◽  
Vol 82 (11) ◽  
pp. 1516-1521 ◽  
Author(s):  
Hajime Tsuji ◽  
Haruchika Masuda ◽  
Teruhisa Kasahara ◽  
Masami Yoshizumi ◽  
Tatsuya Sugano ◽  
...  

SummaryNot only angiotensin II (Ang II) but also other angiotensin metabolites such as angiotensin I (Ang I), angiotensin III (Ang III), angiotensin IV, or angiotensin 1-7 have recently been reported to have various activities. Few data, however, are available on the regulation of thrombus formation. In this study, we investigated the effects of angiotensin metabolites on the mRNA expression of tissue factor (TF), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1), and tissue type plasminogen activator (TPA) in cultured rat aortic endothelial cells. None of the used angiotensin metabolites altered TFPI or TPA mRNA expression levels. Ang I, Ang II, and Ang III made TF and PAI-1 mRNA inductions which were inhibited by an selective antagonist of angiotensin II type 1 receptors. These metabolites made TF predominant to TFPI or PAI-1 to TPA, and could render endothelial cells thrombogenic.


1999 ◽  
Vol 81 (04) ◽  
pp. 601-604 ◽  
Author(s):  
Hiroyuki Matsuno ◽  
Osamu Kozawa ◽  
Masayuki Niwa ◽  
Shigeru Ueshima ◽  
Osamu Matsuo ◽  
...  

SummaryThe role of fibrinolytic system components in thrombus formation and removal in vivo was investigated in groups of six mice deficient in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), or plasminogen activator inhibitor-1 (PAI-1) (u-PA-/-, t-PA-/- or PAI-1-/-, respectively) or of their wild type controls (u-PA+/+, t-PA+/+ or PAI-1+/+). Thrombus was induced in the murine carotid artery by endothelial injury using the photochemical reaction between rose bengal and green light (540 nm). Blood flow was continuously monitored for 90 min on day 0 and for 20 min on days 1, 2 and 3. The times to occlusion after the initiation of endothelial injury in u-PA+/+, t-PA+/+ or PAI-1+/+ mice were 9.4 ± 1.3, 9.8 ± 1.1 or 9.7 ± 1.6 min, respectively. u-PA-/- and t-PA-/- mice were indistinguishable from controls, whereas that of PAI-1-/- mice were significantly prolonged (18.4 ± 3.7 min). Occlusion persisted for the initial 90 min observation period in 10 of 18 wild type mice and was followed by cyclic reflow and reocclusion in the remaining 8 mice. At day 1, persistent occlusion was observed in 1 wild type mouse, 8 mice had cyclic reflow and reocclusion and 9 mice had persistent reflow. At day 2, all injured arteries had persistent reflow. Persistent occlusion for 90 min on day 0 was observed in 3 u-PA-/-, in all t-PA-/- mice at day 1 and in 2 of the t-PA-/-mice at day 2 (p <0.01 versus wild type mice). Persistent patency was observed in all PAI-1-/- mice at day 1 and in 5 of the 6 u-PA-/- mice at day 2 (both p <0.05 versus wild type mice). In conclusion, t-PA increases the rate of clot lysis after endothelial injury, PAI-1 reduces the time to occlusion and delays clot lysis, whereas u-PA has little effect on thrombus formation and spontaneous lysis.


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