Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipoprotein(a) (Lp[a]), a highly atherogenic lipoprotein particle, is the prominent apolipoprotein B-containing lipoprotein in the hedgehog (Laplaud PM et al, J Lipid Res 1988;29:1157-1170). In the present work, we studied the consequences of the structural homology between the specific Lp(a) glycoprotein, apoprotein(a), and plasminogen on the generation of plasmin by fibrin-bound tissue-type plasminogen activator. The activation of plasminogen was initiated by adding either native plasma or Lp(a)-free plasma supplemented with the equivalent of 0.25 mg/ml of either purified Lp(a) or albumin to a surface of fibrin prepared on micortitration plates and to which human tissue-type plasminogen activator was specifically bound. With the Lp(a)-free plasma, an increase in the binding and activation of plasminogen as a function of time was observed. In contrast, in the presence of Lp(a) (i.e., native plasma or the reconstituted system), a significant decrease in the binding of plasmin(ogen) (approximately 60%) was obtained. These data indicate that hedgehog Lp(a) interferes with the binding and activation of plasminogen at the fibrin surface and may thereby behave as a factor regulating the extent of fibrin deposition. These results support our previous data indicating that high levels of Lp(a) may have antifibrinolytic effects in humans (Rouy D et al, Arterioscler Thromb 1991;11:629-638), are in agreement with the observation that Lp(a) is a risk factor for atherosclerotic disease, and provide further support to the view of Lp(a) as a link between atherosclerosis and thrombosis.
 ...
PMID:Hedgehog lipoprotein(a) is a modulator of activation of plasminogen at the fibrin surface. An in vitro study. 153 29

Elevated levels of lipoprotein(a) [Lp(a)] are associated with an increased risk of atherothrombotic disease, but the mechanism(s) by which Lp(a) potentiates atherogenesis is unknown. The extensive homology of apolipoprotein(a) [apo(a)] to plasminogen has led us and others to postulate that Lp(a) may impair fibrinolysis. We have previously shown that Lp(a) inhibits fibrin stimulation of plasminogen activation by tissue-type plasminogen activator (t-PA); however, we and other investigators have been unable to demonstrate direct inhibition of t-PA by Lp(a) in solution. We now report that t-PA binds reversibly and saturably to surface-bound Lp(a) and to low-density lipoprotein (LDL) and that as a result of this binding activation of plasminogen by t-PA is inhibited. The catalytic efficiency (kcat/Km) of t-PA when bound to polystyrene surface-bound fibrinogen increased 2.9-fold compared to t-PA bound to control wells. When bound to surface-bound Lp(a), however, the catalytic efficiency of t-PA was reduced 9.5-fold compared to t-PA bound to control wells; likewise, by binding to surface-bound LDL, the catalytic efficiency of t-PA was reduced 16-fold compared to the control. Studies with defined monoclonal antibodies suggest that major determinants of t-PA binding are its active site, the LDL receptor binding domain of apolipoprotein B-100 (apoB-100), and apo(a). These data suggest a unique mechanism by which Lp(a) and LDL incorporated in an atheroma can inhibit endogenous fibrinolysis and thereby contribute to the genesis of atherothrombotic disease.
 ...
PMID:Tissue-type plasminogen activator binds to and is inhibited by surface-bound lipoprotein(a) and low-density lipoprotein. 182 35

Human plasma contains an inhibitor of tissue factor-initiated coagulation known as the lipoprotein-associated coagulation inhibitor (LACI) or also known as the extrinsic pathway inhibitor (EPI). A competitive fluorescent immunoassay was developed to measure the plasma concentration of LACI in samples from normal individuals and patients with a variety of diseases. The LACI concentration in an adult control population varied from 60% to 160% of the mean with a mean value corresponding to 89 ng/mL or 2.25 nmol/L. Plasma LACI levels were not decreased in patients with severe chronic hepatic failure, warfarin therapy, primary pulmonary hypertension, thrombosis, or the lupus anticoagulant. Plasma LACI antigen was decreased in some, but not all patients with gram-negative bacteremia and evidence for disseminated intravascular coagulation. Plasma LACI levels were elevated in women undergoing the early stages of labor (29%), in patients receiving intravenous tissue-type plasminogen activator (45%), and in patients receiving intravenous heparin (375%). A radioligand blot of the pre- and post-heparin plasma samples shows the increase to be in a 40-Kd form of LACI. Very low levels of plasma LACI antigen were found in patients with homozygous abetalipoproteinemia and hypobetalipoproteinemia, diseases associated with low plasma levels of apolipoprotein B containing lipoproteins. Following the injection of heparin into one patient with homozygous abetalipoproteinemia, the plasma LACI antigen level increased to a level comparable with that in normal individuals after heparin treatment.
 ...
PMID:Plasma antigen levels of the lipoprotein-associated coagulation inhibitor in patient samples. 207 76

The aim of the present study was to evaluate some metabolic, coagulation and fibrinolytic parameters in 35 patients (24 males and 11 females, mean age 57 +/- 4 years) suffering from myocardial infarction more than 6 months before with or without carotid atherosclerotic lesions. After evaluation by B-mode duplex scanning system of extracranial carotid arteries, the patients were subdivided into two groups: Group 1 (n = 16, with carotid plaques or intima-media thickening) and Group 2 (n = 19, without carotid plaques or intima-media thickening). Eighteen age- and sex-matched subjects were recruited as controls (Group 3). Groups 1 and 2 displayed significantly higher levels of total cholesterol and apolipoprotein B and significantly lower levels of HDL-cholesterol and apolipoprotein A1 than Group 3, while serum triglyceride and lipoprotein (a)-Lp (a) levels were significantly higher in Group 1 as compared to the control group. Moreover, Group 1 and 2 displayed significantly higher levels of factor VII, fibrinogen, F1+2, thrombin-antithrombin complex and plasminogen activator inhibitor (PAI) post venous occlusion and significantly lower levels of tissue plasminogen activator (t-PA) post venous occlusion than Group 3. Significantly higher levels of t-PA and PAI pre venous occlusion and significantly lower levels of antithrombin III, C-protein and S-protein were observed in Group 1 as compared to controls. In patients with highest Lp(a) level, the lowest t-PA level post venous occlusion and the highest PAI level post venous occlusion were observed. Our data show an activation of coagulation and a deficient fibrinolysis in survivors of myocardial infarction, particularly in those with associated carotid atherosclerotic lesions. We speculate that this thrombophilic state may play a key role in the pathogenesis of atherosclerotic vascular disease and thromboembolic complications.
 ...
PMID:[Thrombophilic state inpatients suffering from myocardial infarction with or without carotid atherosclerotic lesions]. 870 61

To assess whether plasminogen activator inhibitor 1 (PAI-1) activity is elevated in the progeny of young coronary men, 193 young subjects were recruited and divided into two groups. Group A consisted of 104 children whose fathers had suffered a myocardial infarction before the age of 55 ("cases"). Eighty-nine young subjects matched for age, sex, body mass index (BMI) and smoking habits without familial history of coronary artery disease (CAD) served as controls (group B). Children with a family history of diabetes mellitus or hypertension were excluded from both groups. We measured PAI-1 activity, tissue-type plasminogen activator (t-PA) antigen, a2-antiplasmin, fibrinogen, lipids and apolipoproteins in both groups. PAI-1 activity levels were also determined in the men who suffered a premature myocardial infarction 4 months after their discharge. PAI-1 activity levels were higher in cases compared to controls (3.13 +/- 1.9 vs 2.17 +/- 1.9 U/ml, p = 0.0014). t-PA antigen and a2-antiplasmin did not differ significantly between the two groups, while fibrinogen, total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B and lipoprotein(a) were significantly higher in group A. PAI-1 was positively correlated with triglycerides (r = 0.22, p = 0.024), apolipoprotein B (r = 0.21, p = 0.039) and fibrinogen (r = 0.22, p = 0.029) in cases and with BMI in both cases (r = 0.37, p = 0.0003) and controls (r = 0.23, p = 0.044). In stepwise multiple regression analysis, only apolipoprotein B (p = 0.008) and BMI (p = 0.0014) were significant determinants of PAI-1 activity in cases. There was also a positive correlation between PAI-1 activity levels of the affected fathers and their children (r = 0.30, p = 0.01). The present data support the hypothesis that elevated PAI-1 levels in the offspring of men with premature myocardial infarction impair their fibrinolytic capacity contributing to their familial predisposition to CAD.
 ...
PMID:Plasminogen activator inhibitor 1 is elevated in the children of men with premature myocardial infarction. 888 80

Oestrogen replacement therapy is associated with a decreased risk of cardiovascular disease in postmenopausal women. Patients with non-insulin-dependent diabetes mellitus (NIDDM) have an increased cardiovascular risk. However, oestrogen replacement therapy is only reluctantly prescribed for patients with NIDDM. In a double blind randomized placebo controlled trial we assessed the effect of oral 17 beta-estradiol during 6 weeks in 40 postmenopausal women with NIDDM. Glycated haemoglobin (HbA1c), insulin sensitivity, suppressibility of hepatic glucose production, lipoprotein profile and parameters of fibrinolysis were determined. The oestrogen treated group demonstrated a significant decrease of HbA1c and in the normotriglyceridaemic group a significantly increased suppression of hepatic glucose production by insulin. Whole body glucose uptake and concentrations of non-esterified fatty acids did not change. LDL-cholesterol- and apolipoprotein B levels decreased, and HDL-cholesterol, its subfraction HDL2-cholesterol and apolipotrotein A1 increased. The plasma triglyceride level remained similar in both groups. Both the concentration of plasminogen activator inhibitor-1 antigen and its active subfraction decreased. Tissue type plasminogen activator activity increased significantly only in the normotriglyceridaemic group. Oestrogen replacement therapy improves insulin sensitivity in liver, glycaemic control, lipoprotein profile and fibrinolysis in postmenopausal women with NIDDM. For a definite answer as to whether oestrogens can be more liberally used in NIDDM patients, long term studies including the effect of progestogens are necessary.
 ...
PMID:Short-term oestrogen replacement therapy improves insulin resistance, lipids and fibrinolysis in postmenopausal women with NIDDM. 924 7

The aim of the present study was to evaluate metabolic, coagulation and fibrinolytic parameters in 45 patients [31 men, 14 women, aged 56.5 +/- 3.5 years (mean +/- SD)] who had suffered myocardial infarction more than 6 months earlier, with or without carotid atherosclerotic lesions. After the extracranial carotid arteries had been evaluated using a B-mode Duplex scanning system, patients were subdivided into two groups: group 1 (n = 20) with carotid plaques or measurable intima-media thickness; and group 2 (n = 25) without carotid plaques or measurable intima-media thickness. Twenty-two age- and sex-matched subjects were recruited as controls (group 3). Groups 1 and 2 displayed significantly higher levels of total cholesterol, apolipoprotein B, human autoantibodies against oxidised low-density lipoprotein and the c fraction of the third component system, and significantly lower levels of high-density lipoprotein cholesterol and apolipoprotein A1 than group 3. However, serum levels of triglyceride and lipoprotein (a) were significantly higher in group 1 than in the control group. Moreover, groups 1 and 2 displayed significantly higher levels of factor VII, fibrinogen, fragment 1+2, thrombin-antithrombin complex and plasminogen activator inhibitor after venous occlusion, and significantly lower levels of tissue-type plasminogen activator after venous occlusion than group 3. Significantly higher levels of tissue-type plasminogen activator and plasminogen activator inhibitor before venous occlusion were observed in groups 1 and 2 and significantly lower levels of antithrombin III, protein C and protein S were observed in group 1 compared with the controls. Patients were also analysed according to levels of lipoprotein (a). The lowest levels of tissue-type plasminogen activator after venous occlusion and the highest levels fragment 1 + 2, the c fraction of the third component system, and plasminogen activator inhibitor after venous occlusion were observed in patients with the highest levels of lipoprotein (a). Our data demonstrate an activation of coagulation and deficient fibrinolysis in survivors of myocardial infarction, particularly in those with associated carotid atherosclerotic lesions. We speculate that this thrombophilic state may play a key role in the pathogenesis of atherosclerotic vascular disease and thromboembolic complications.
 ...
PMID:Elevated levels of lipoprotein (a) in patients suffering from myocardial infarction with carotid atherosclerotic lesions. 1049 14

Several prospective studies have demonstrated a direct association between C-reactive protein (CRP) levels and the risks of developing cardiovascular disease. Few studies, however, have explored the interrelations between CRP levels and other risk factors for cardiovascular disease. We evaluated the relation of CRP with several cardiovascular risk factors in a cross-sectional survey of 1,172 apparently healthy men. There were significant positive associations between CRP levels and age, number of cigarettes smoked per day, body mass index, systolic and diastolic blood pressure, total cholesterol, triglycerides, lipoprotein(a), apolipoprotein B, tissue-type plasminogen activator antigen, D-dimers, total homocysteine, and fibrinogen (all p values <0.05). Significant inverse associations were observed for exercise frequency, high-density lipoprotein cholesterol, and apolipoprotein A-I and A-II (all p values <0.02). In multivariate analysis, age, smoking status, and serum levels of tissue-type plasminogen activator antigen, fibrinogen, lipoprotein(a), and total homocysteine were independent correlates of CRP levels. Finally, in an analysis controlled either for all the independent correlates or for several usual risk factors, we observed progressive increases in levels of CRP with increasing prevalence of risk factors (p for trend <0.001 for independent correlates and <0.01 for usual risk factors). In conclusion, in a large cohort of apparently healthy men, CRP levels were associated with several cardiovascular risk factors. These data are compatible with the hypothesis that CRP levels may be a marker for preclinical cardiovascular disease.
 ...
PMID:Survey of C-reactive protein and cardiovascular risk factors in apparently healthy men. 1056 56

We compared the effects of oral estradiol (2 mg), transdermal estradiol (50 microg), and placebo on measures of coagulation, fibrinolysis, inflammation and serum lipids and lipoproteins in 27 postmenopausal women at baseline and after 2 and 12 weeks of treatment. Oral and transdermal estradiol induced similar increases in serum free estradiol concentrations. Oral therapy increased the plasma concentrations of factor VII antigen (FVIIag) and activated factor VII (FVIIa), and the plasma concentration of the prothrombin activation marker prothrombin fragment 1+2 (F1+2). Oral but not transdermal estradiol therapy significantly lowered plasma plasminogen activator inhibitor-1 (PAI-1) antigen and tissue-type plasminogen activator (tPA) antigen concentrations and PAI-1 activity, and increased D-dimer concentrations, suggesting increased fibrinolysis. The concentration of soluble E-selectin decreased and serum C-reactive protein (CRP) increased significantly in the oral but not in the transdermal or placebo groups. In the oral but not in the transdermal or placebo estradiol groups low-density-lipoprotein (LDL) cholesterol, apolipoprotein B and lipoprotein (a) concentrations decreased while high-density-lipoprotein (HDL) cholesterol, apolipoprotein AI and apolipoprotein All concentrations increased significantly. LDL particle size remained unchanged. In summary, oral estradiol increased markers of fibrinolytic activity, decreased serum soluble E-selectin levels and induced potentially antiatherogenic changes in lipids and lipoproteins. In contrast to these beneficial effects, oral estradiol changed markers of coagulation towards hypercoagulability, and increased serum CRP concentrations. Transdermal estradiol or placebo had no effects on any of these parameters. These data demonstrate that oral estradiol does not have uniformly beneficial effects on cardiovascular risk markers and that the oral route of estradiol administration rather than the circulating free estradiol concentration is critical for any changes to be observed.
 ...
PMID:Effects of oral and transdermal estrogen replacement therapy on markers of coagulation, fibrinolysis, inflammation and serum lipids and lipoproteins in postmenopausal women. 1134 95

The study was carried out in a group of 285 children and adolescents aged 4-20 yrs. Children were divided according to their main disease: group with obesity, obesity and coexisting hypertension, hypertension and diabetes. Each group was divided into children with positive or negative family history of cardiovascular diseases. We assessed routine lipid parameters, body mass index and new atherosclerosis risk factors: lipoprotein (a), apolipoproteins A-I and B, homocysteine, fibrinogen, t-PA and PAI-1. Positive family history of cardiovascular diseases was found in 28% families, and in 8% families it was premature cardiovascular disease. In 48% children we found hypertension in family. Children with positive family history had significantly higher body mass index (25.4 vs 23.8 kg/m2). In the group with obesity and hypertension we found significantly higher cholesterol (182 vs 160 mg/dl) and LDL-cholesterol level (114 vs 93 mg/dl). Lipoprotein(a) level was significantly higher in children with positive family history (38 vs 28 mg/dl). Significant differencies were also found in apolipoprotein B level (90 vs 84 mg/dl). In logistic regression analysis only BMI and lipoprotein(a) were significant in predicting future cardiovascular events in children. Obese, hypertensive and diabetic children often come from families with cardiovascular diseases. Hypertension is the most often prevalent atherosclerosis risk factor in families. Children with positive family history of cardiovascular diseases have significantly higher body mass index. Out of new atherosclerosis risk factors lipoprotein(a) and apolipoprotein B may have real value in predicting future cardiovascular disease in the child. The aim of the study was to compare obese, hypertensive and diabetic children with positive and negative family history of cardiovascular diseases. In the work we have tried to find which of the new atherosclerosis risk factors may have the real value in predicting future cardiovascular events in children already predisposed to atherosclerosis.
 ...
PMID:[Correlation between body mass index, lipoprotein (a) level and positive family history of cardiovascular diseases in children and adolescents with obesity, hypertension and diabetes]. 1199 45


1 2 Next >>