Plasma Plasminogen Activator Inhibitor-1 Activity Levels Research Articles

PAI-1 level and the PAI-1 4G/5G polymorphism in relation to risk of non-fatal myocardial infarction: results from the Stockholm Heart Epidemiology Program (SHEEP).

This study examines the relationship between plasma Plasminogen Activator Inhibitor-1 (PAI-1) activity and the PAI-1 4G/5G polymorphism, and their association with the risk of myocardial infarction (MI). Furthermore, this study explores whether a high level of PAI-1 or whether the PAI-1 4G/5G polymorphism synergistically interacts with any established environmental risk factor for MI. This case-referent study of subjects aged 45-70 and living in Stockholm includes 851 men and 361 women with first-time MI and 1051 men and 505 women who were randomly chosen as referents from a population register. The adjusted odds ratio (OR) of MI was 1.9 (95% confidence interval [CI] 1.4-2.8) for men with a plasma PAI-1 activity level greater than the 90 th percentile value of referents. The corresponding OR for women was 1.5 (95% CI 0.9-2.5). A strong indication of synergistic interaction was found in men for the co-exposure to high plasma PAI-1 activity and current smoking, an adjusted synergy index score of 3.9 (95% CI 1.2-13.2). In women, the 4G allele was associated slightly with an increased risk of MI, OR 1.4 (95% CI 1.0-1.9). This association was not found in men. There were no clear indications of synergistic interaction effects involving the PAI-1 4G/5G polymorphism and the environmental exposures considered (cigarette smoking, physical inactivity, overweight, diabetes mellitus, hypercholesterolaemia, hypertension, high C-reactive protein and hypertriglyceridaemia).

The impact of the PAI-1 4G/5G polymorphism on the outcome of patients with ALI/ARDS

Intoduction Increased levels of plasminogen activator inhibitor-1 (PAI-1) have been associated with worse outcome in ALI/ARDS. A single guanosine insertion/deletion (4G/5G) polymorphism in the promoter region of the PAI-1 gene, may play an important role in the regulation of PAI-1 expression. The objective of the study was to evaluate the effect of this polymorphism on the outcome of critically ill patients with ALI/ARDS. Materials and Methods 52 consecutive ventilated patients with ALI/ARDS were studied. Bronchoalveolar lavage was performed within 48 hours from diagnosis. Measurement of plasma and BALF PAI-1 activity and D-dimers levels, and 4G/5G genotyping of PAI-1 were carried out. The primary outcome was 28-day mortality, and secondary outcomes included organ dysfunction and ventilator-free days. Results 17 patients were homozygotes for the 4G allele. Severity scores were not different between subgroups upon study enrollment. 28-day mortality was 70.6% and 42.9% for the 4G-4G and the non-4G-4G patients, respectively (p = 0.06). PAI-1 activity levels and D-dimer in plasma and BALF were not significantly different between the 4G-4G and the non-4G-4G subgroups. In the multivariate analysis, genotype 4G/4G was the only variable independently associated with 28-day mortality (Odds Ratio = 9.95, 95% CI: 1.79-55.28, p = 0.009). Furthermore, genotype 4G/4G and plasma PAI-1 activity levels were independently negatively associated with ventilator free days (p = 0.033 and p = 0.008, respectively). Conclusions ALI/ARDS patients, homozygous for the 4G allele of the PAI-1 gene, experienced higher 28-day mortality. This genotype was associated with a reduction in the number of days of unassisted ventilation and was inversely associated with the number of days without organ failure.

Study on effect of different dosages of ligustrazine on level of plasminogen activator inhibitor-1 activity in type 2 diabetes mellitus patients

Objective: To observe the effect of different dosages of ligustrazine (LG) on the level of plasminogen activator inhibitor-1 (PAI-1) activity in patients with type 2 diabetes mellitus.Methods: Ninety cases of type 2 diabetes mellitus inpatients were selected, and randomly divided into LG small dosage group (SDG), LG large dosage group (LDG) and control group. The 120 mg LG, 400 mg LG and normal saline 250 ml were given through intravenous dripping respectively, once daily, 20 days as one treatment course. Before and after treatment, all the patients had their fasting blood taken for PAI-1 and tissue plasminogen activator (t-PA) assessment test to perform the comparative study.Results: Seventythree out of the 90 patients completed the observation course, the PAI-1 activity of three groups after treatment all lowered compared with that before treatment, and the difference between groups was also significant (allP < 0.01). After treatment the PAI-1 level of SDG and LDG of LG were all markedly lowered (allP < 0.01), the LDG’s lowering was more evident than that of SDG, and comparison between these two groups of patients showed significant difference (P < 0.01). Although in the control group there was some difference between before and after treatment, it was not so significant like the above-mentioned two groups (P = 0. 0140). No adverse reaction occurred in the 3 groups during the observation period.Conclusion: LG could safely and effectively lower type 2 diabetes mellitus patient’s plasma PAI-1 activity level, and LDG of LG proved to be particularly effective.

Increased expression of plasminogen activator inhibitor-1 by mediators of the acute phase response: a potential progenitor of vasculopathy in hypertensives.

Hypertension is an important risk factor for coronary atherosclerosis, which is accelerated by inflammation and diminished fibrinolysis. We have previously shown that levels of plasminogen activator inhibitor-1 (PAI-1), the major physiologic inhibitor of fibrinolysis, are increased with atherogenic metabolic derangement. Because the liver is one of the major sources of circulating PAI-1, we here examined the effects of two proinflammatory cytokines, interleukin (IL)-1beta, and IL-6, on PAI-1 production in a human hepatoma cell line, HepG2. IL-1beta (1 ng/ml) and IL-6 (1 ng/ml) increased the accumulation of PAI-1 in the conditioned media over 24 h (IL-1beta: 2.1 +/- 0.2 (mean +/- SD) fold over the control; IL-6:1.4 +/- 0.2 fold; Western blot, p < 0.05). The increase in PAI-1 protein accumulation correlated with the increased expression of PAI-1 mRNA (Northern blot). An HMG-CoA reductase inhibitor (mevastatin, 10 micromol/l) attenuated the PAI-1 production induced by IL-1beta and IL-6. The plasma PAI-1 activity level was higher in hypertensives than in normotensives (10.0 +/- 9.8 AU/ml vs. 6.2 +/- 4.5 AU/ml, p < 0.05). The plasma PAI-1 antigen level was also higher in hypertensives than in normotensives (30.9 +/- 22.4 ng/ml vs. 24.4 +/- 13.3 ng/ml, p < 0.05). Thus, 1) IL-1beta and IL-6 can increase PAI-1 production in hepatic cells and 2) mevastatin may exert anti-thrombotic effects by decreasing the PAI-1 protein production induced by these proinflammatory cytokines. These results provide further insights into how inflammation is involved in the atherothrombotic complications observed in hypertensives, which may be ameliorated by HMG-CoA reductase inhibitors.

PAI-1 level and the PAI-1 4G/5G polymorphism in relation to risk of non-fatal myocardial infarction

SummaryThis study examines the relationship between plasma Plasminogen Activator Inhibitor-1 (PAI-1) activity and the PAI-1 4G/5G polymorphism, and their association with the risk of myocardial infarction (MI). Furthermore, this study explores whether a high level of PAI-1 or whether the PAI-1 4G/5G polymorphism synergistically interacts with any established environmental risk factor for MI. This case-referent study of subjects aged 45-70 and living in Stockholm includes 851 men and 361 women with first-time MI and 1051 men and 505 women who were randomly chosen as referents from a population register. The adjusted odds ratio (OR) of MI was 1.9 (95% confidence interval [CI] 1.4-2.8) for men with a plasma PAI-1 activity level greater than the 90th percentile value of referents. The corresponding OR for women was 1.5 (95% CI 0.9-2.5). A strong indication of synergistic interaction was found in men for the co-exposure to high plasma PAI-1 activity and current smoking, an adjusted synergy index score of 3.9 (95% CI 1.2-13.2). In women, the 4G allele was associated slightly with an increased risk of MI, OR 1.4 (95% CI 1.0-1.9). This association was not found in men. There were no clear indications of synergistic interaction effects involving the PAI-1 4G/5G polymorphism and the environmental exposures considered (cigarette smoking, physical inactivity, overweight, diabetes mellitus, hypercholesterolaemia, hypertension, high C-reactive protein and hypertriglyceridaemia).

Fibrinolytic Proteins and Progression of Coronary Artery Disease in Relation to Gemfibrozil Therapy

Impaired fibrinolytic function, mainly due to increased plasma plasminogen activator inhibitor-1 (PAI-1) activity, is common in patients with manifest coronary artery disease (CAD) and a predictor of recurrent cardiovascular events. We investigated the relationships of plasma tissue-type plasminogen activator (tPA) and PAI-1 antigen levels, plasma PAI-1 activity and PAI 4/5-guanosine (4G/5G) genotype to CAD progression in 203 middle-aged men participating in the Lopid Coronary Angiography Trial (LOCAT). A higher tPA antigen concentration, whether baseline or on-trial, was associated with a more severe global angiographic response (p < 0.05), an association mainly accounted for by progression of diffuse lesions in graft-affected segments (change in per-patient means of average diameters of segments haemodynamically related to bypass grafts). Plasma PAI-1 activity and mass concentration and 4G/5G PAI-1 genotype were unrelated to angiographic outcome measurements. tPA and PAI-1 antigen increased significantly in the gemfibrozil group (+11.3% and + 16.4%, respectively, p < 0.001), whereas there was no treatment effect on PAI-1 activity (median change 0.0%). It is concluded that fibrinolytic function does not substantially influence progression of CAD as assessed by angiography in middle-aged men. Furthermore, pronounced long-term lowering of serum triglycerides by gemfibrozil treatment does not significantly affect the plasma PAI-1 activity level but increases the plasma tPA and PAI-1 antigen concentrations.

An Insertion/Deletion polymorphism in the promoter region of the plasminogen activator inhibitor-1 gene is associated with plasma levels but not with stroke risk in the elderly

The purpose of the present study was to examine the effects of an insertion/deletion (ins/del) polymorphism in the promoter region of the plasminogen activator inhibitor-1 (PAI-1) gene on plasma PAI-1 antigen and activity levels and on stroke risk in the elderly. The ins/del genotype and PAI-1 antigen and activity plasma levels were determined in 177 patients with ischemic stroke (mean age, 75 years) and 93 healthy elderly subjects (mean age, 74 years). There was no difference in the frequencies of the ins and del alleles between stroke patients and healthy elderly subjects. The del/del genotype was associated with the highest plasma PAI-1 antigen levels in the healthy subjects: those with the ins/ins genotype had 36% lower plasma PAI-1 antigen levels than those with the del/del genotype (effect of genotype, P=0.3). In contrast, the ins/del genotype was not associated with plasma PAI-1 antigen and activity levels in 89 patients who had a stroke less than 10 days before blood sampling. However, an association of ins/del genotype with plasma PAI-1 activity levels could be demonstrated in 88 other patients more than 5 months after the stroke. This may suggest that PAI-1 metabolism is temporarily perturbed after a stroke. The present data suggest that an ins/del polymorphism in the PAI-1 promoter region affects plasma PAI-1 levels but has little or no effect on stroke risk in the elderly.

Proneness to Formation of Tight and Rigid Fibrin Gel Structures in Men with Myocardial Infarction at a Young Age

The native fibrin gel structure formed in vitro from plasma samples was examined by liquid permeation of hydrated fibrin gel networks in 38 unselected men who had suffered a myocardial infarction before the age of 45 years and in 88 age-matched population-based control men. Both the fibrin gel porosity (permeability coefficient, Ks) and the calculated fiber mass-length ratio varied considerably within the two groups, but were generally lower in the patients. Ks was 8.3 +/- 5.2 cm2 x 10(9) (mean +/- SD) in the patient group and 12.5 +/- 5.7 cm2 x 10(9) among controls (p < 0.001). The corresponding figures for fiber mass-length ratio were 13.1 +/- 7.7 and 16.5 +/- 7.5 Dalton/ cm x 10(-13), respectively (p < 0.01). Around 50% of the patients had Ks values below the 10th percentile of the control group. A strong inverse correlation was seen between plasma plasminogen activator inhibitor-1 (PAI-1) activity and Ks (r = -0.603, p < 0.001) or fiber mass-length ratio (r = -0.565, p < 0.001) in the patient group. Corresponding weaker associations of PAI-1 with fibrin gel properties were also present in the control group. In addition, inverse relationships of very low density lipoprotein (VLDL) triglyceride concentrations to Ks (r = -0.362, p < 0.001) and fiber mass-length ratio (r = -0.283, p < 0.01) were found among the controls. Proneness to formation of tight and rigid fibrin gel networks with abnormal architecture in vitro is in vivo associated with myocardial infarction at a young age. Impaired fibrinolytic function secondary to a raised plasma PAI-1 activity level is associated with abnormal fibrin gel structure.