Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The composition of atherosclerotic plaques is a crucial factor in determining rupture, thrombosis and clinical events. In this study, we analyzed gene expression in coronary plaques from patients with stable or unstable angina using gene arrays. Total RNA was extracted from eight plaques collected by therapeutic directional coronary atherectomy. cDNA probes, generated by amplification, were hybridized to nylon arrays containing 482 genes. Here we report the results for the inflammation, adhesion and hemostasis subsets. Many genes not previously associated with atherosclerosis, such as the lymphocyte adhesion molecule MadCAM, were expressed in the plaques. anova analysis showed higher tissue factor (TF) expression in unstable angina samples. Five genes were expressed at lower levels in unstable angina samples: anticoagulant protein S, cyclooxygenase (COX)-1, interleukin (IL)-7 and chemokines monocyte chemotactic protein (MCP)-1 and -2. Gene arrays provide a new approach to study plaque composition and identify candidate markers of plaque instability.
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PMID:Identification of differentially expressed genes in coronary atherosclerotic plaques from patients with stable or unstable angina by cDNA array analysis. 1287 22

Abnormal endothelium-dependent vasodilatation is well documented in coronary artery disease (CAD), as are significant increases of acute phase inflammatory proteins and other soluble hepatic and endothelium derived proteins. In the current study we investigated whether there is a relationship between endothelium-dependent vasodilatation and the plasma levels of such proteins. Further we examined the association between these proteins, together with age, cholesterol and endothelium function, and participant status (i.e. healthy, smoker, coronary artery disease). Three groups of participants were recruited: healthy controls (n = 20), cigarette smokers (n = 20) and patients with coronary artery disease (n = 20). Forearm vascular dilatation responses to the endothelium-dependent agonist acetylcholine were obtained using venous occlusion plethysmography. Blood was sampled at the time of study for the measurement of the serological proteins described above. Responses to acetylcholine were significantly dampened in patients with CAD when compared with control and smoker groups (forearm blood flow at acetylcholine 37 microg/min): control, smokers, CAD, 12.14 +/- 2.14, 12.35 +/- 09.4, 5.12 +/- 0.81, ANOVA, P < 0.05). Responses to acetylcholine were not different between controls and smokers. C-reactive protein (C-RP) levels (controls, smokers, CAD, 1.40 +/- 0.19, 2.27 +/- 0.71, 4.73 +/- 1.09, P < 0.05) and protein S levels were significantly higher in the CAD group compared with the other two groups. There was a significant inverse correlation between forearm blood flow responses to acetylcholine and C-reactive proteins. Both responses to acetylcholine and C-RP levels demonstrated a significant association with participant status with the r value increasing from 0.405 for responses to acetylcholine to 0.491 for the combination of responses to acetylcholine and C-RP. We conclude that there is an inverse correlation between C-reactive protein, but not protein S, VCAM-1, P-selectin nor von Willebrand factor, levels and abnormal endothelium-dependent vasodilation and further that responses to acetylcholine together with C-RP protein have a strong association with cardiovascular risk and disease.
Atherosclerosis 2004 Feb
PMID:Plasma C-reactive protein, but not protein S, VCAM-1, von Willebrand factor or P-selectin, is associated with endothelium dysfunction in coronary artery disease. 1538 Apr 69

Tissue factor (TF) plays an important role in hemostasis, inflammation, angiogenesis, and the pathophysiology of atherosclerosis and cancer. In this article we uncover a mechanism in which protein S, which is well known as the cofactor of activated protein C, specifically inhibits TF activity by promoting the interaction between full-length TF pathway inhibitor (TFPI) and factor Xa (FXa). The stimulatory effect of protein S on FXa inhibition by TFPI is caused by a 10-fold reduction of the K(i) of the FXa/TFPI complex, which decreased from 4.4 nM in the absence of protein S to 0.5 nM in the presence of protein S. This decrease in K(i) not only results in an acceleration of the feedback inhibition of the TF-mediated coagulation pathway, but it also brings the TFPI concentration necessary for effective FXa inhibition well within range of the concentration of TFPI in plasma. This mechanism changes the concept of regulation of TF-induced thrombin formation in plasma and demonstrates that protein S and TFPI act in concert in the inhibition of TF activity. Our data suggest that protein S deficiency not only increases the risk of thrombosis by impairing the protein C system but also by reducing the ability of TFPI to down-regulate the extrinsic coagulation pathway.
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PMID:Protein S stimulates inhibition of the tissue factor pathway by tissue factor pathway inhibitor. 1648 80

Systemic lupus erythematosus (SLE) is a chronic inflammatory disorder with a high prevalence of cardiovascular disease due to accelerated atherosclerosis, as well as an increased risk of venous thromboembolism. Many of these clinical features have been attributed to the high prevalence of autoantibodies that are directed against phospholipid-bound antigens and that induce prothrombotic effects and disturb endothelial cell function. We conducted a case-control study in a cohort of female patients with SLE and in age-matched and sex-matched normal individuals. Patients had significantly higher levels of plasma inflammatory markers, but their overall coagulation status assessed by prothrombin fragment 1 + 2 and D-dimer plasma levels was not different from controls. Resistance against activated protein C (APC), assessed by a thrombin generation-based as well as an activated partial thromboplastin time-based method, however, was increased in patients. This defect was neither due to factor V Leiden carriership or to the use of oral contraceptives. This acquired form of APC resistance was due to proinflammatory changes associated with lower plasma levels of free protein S. In conclusion, acquired APC resistance may be an important determinant of the risk of thrombosis in patients with SLE, probably due to an active cross-talk between inflammation and coagulation systems.
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PMID:The inflammation and coagulation cross-talk in patients with systemic lupus erythematosus. 1717 22

GAS6, the product of growth arrest specific (GAS) gene 6 is a ligand for the tyrosine protein kinase receptors Axl, Tyro3 and Mer whose signaling has been implicated in cell growth, survival, adhesion and migration. Although a secreted human vitamin K-dependent protein with close structural similarity with protein S, GAS6 does not exhibit anticoagulant properties but rather may be an important regulator of vascular homeostasis and platelet signaling. GAS6 signals via its receptor tyrosine kinases and appears to modulate platelet outside-in signaling via GP alpha(IIb)beta(III), playing a key role in the perpetuation of platelet aggregates and clot retraction. GAS6 is also implicated in foam cell formation and neointimal proliferation in response to vascular injury. Thus GAS6 acts at key points in the pathophysiology of atherosclerosis and thrombosis; two processes implicated in most acute cardiovascular pathology. Inhibition of GAS6 or its receptors may provide antithrombotic activity in the absence of increased bleeding and thus presents an attractive drug target. GAS6 signaling may be modulated through direct antibody inhibition, blockade of its receptors or GAS6 trapping. However, ubiquitous expression of GAS6 and its receptors and the diverse biological effects of the pathway may make selective drug targeting difficult.
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PMID:Growth arrest specific gene (GAS) 6 modulates platelet thrombus formation and vascular wall homeostasis and represents an attractive drug target. 1789 8

Anti-phospholipid syndrome (APS) is defined based on both clinical findings (recurrent arterial and/or venous thrombosis and recurrent fetal loss) and laboratory evidence of persistent anti-phospholipid antibodies (anti-cardiolipin antibodies, anti-beta2 glycoprotein I antibodies, or LA activity). However, the precise mechanism responsible for arterial and/or venous thromboembolic complications in APS patients remains unclear. To clarify the association between the various types of anti phospholipid antibodies (aPLs) and thrombotic complications, we examined the prevalence of seven types of aPLs [anti-cardiolipin/beta2-glycoprotein I antibodies(anti-CL/beta2-GPI), anti-phosphatidylserine/prothrombin antibodies(anti-PS/PT), anti-beta2-glycoprotein I antibodies (anti-beta2-GPI), anti prothrombin antibodies (anti-PT), anti-protein C antibodies (anti-PC), anti-protein S antibodies(anti-PS), and annexin V antibodies(anti-AN)] in 168 patients with systemic lupus erythematosus (SLE). We confirmed that the presence of anti-CL/beta2-GPI, anti-PS/PT, and anti-beta2-GPI is closely related to arterial thrombosis, and that the presence of anti-protein S is closely related to venous thromboembolism. Furthermore, our in-vitro experiment suggests that anti-CL/beta2-GPI and anti-PS/PT may cooperate to promote platelet activation, and may be involved in the pathogenesis of arterial thrombosis. On the other hand, anti-protein S led to APC resistance, which may represent an important mechanism responsible for the development of venous thrombosis. Furthermore, our study showed that anti-CL/beta2-GPI causes a persistently high-level expression of tissue factor on monocytes, and this may increase the risk of atherosclerosis.
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PMID:[Advanced clinical laboratory studies in the graduate school of medicine--studies on pathogenic mechanisms of anti-phospholipid syndrome]. 1976 14

This is a review of less well-known aspects of thrombophilia and hypercoagulability as they relate to thrombosis. Thrombosis is an abnormal fibrin clot that develops in circulating blood with clinical symptoms of one or more arterial and/or venous obstructions exclusively identified by imaging techniques. The terms thrombophilia and hypercoagulability are often used indiscriminately when they are in fact separate entities. Thrombophilia is an inherited or acquired clinical phenotype manifesting in selected individuals as a greater risk to develop recurrent thrombosis at a younger age than the general population, with considerable differences in the magnitude of risks among individuals in the same family with the same thrombophilic gene defect. Hypercoagulability is a laboratory phenotype whereby in vivo activation of clotting, fibrinolysis, endothelial cells and platelets is identified in vitro by specialized clotting techniques and by specific antibodies directed at biomarkers of clotting activation and damaged vasculature. Hypercoagulability may be provoked by drugs to treat bleeding in hemophilia, by sepsis, inflammation, surgery, blood stasis, atherosclerosis, and it manifests selectively in inherited and acquired thrombophilia. A chronology of the discovery of acquired and inherited thrombophilia puts in perspective the data analyzed in two representative large family studies that address whether venous and arterial thrombosis are a necessary outcome in thrombophilia, and the question, whether patients with inherited antithrombin, protein C and protein S deficiencies need to be treated after a first episode of thrombosis. The liberal use of case vignettes emphasizes a close relationship and the distinction between thrombosis, thrombophilia and hypercoagulability.
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PMID:Thrombophilia and hypercoagulability. 1979 18

Bicuspid aortic valve is one of the most common congenital heart valve disorders. We present the development of acute myocardial infarction (AMI) in an 18-year-old male patient with unrecognized bicuspid aortic valve and moderate aortic regurgitation. He presented with chest pain. The electrocardiogram showed ST-segment elevation in leads V2 to V6. Creatine kinase-MB level was elevated to 97 U/l and troponin I was very high (45,000 ng/ml). The diagnosis was made as anterior wall AMI. Following treatment with intravenous rt-PA, ST-segment elevation completely returned to normal. Transthoracic echocardiography showed a bicuspid aortic valve, moderate aortic regurgitation, and apical wall hypokinesia; left ventricular global systolic function was normal. The patient had no risk factors for coronary atherosclerosis, nor a history of substance addiction or a family history of coronary artery disease. Protein C, protein S and homocysteine levels were normal. He refused any further intervention. Two weeks after discharge, he presented again with chest pain. Electrocardiography, cardiac markers, and coronary arteriography were normal. He was discharged on appropriate medical treatment. The presented case is the first report of AMI in a patient with bicuspid aortic valve.
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PMID:Acute myocardial infarction in a young patient with bicuspid aortic valve. 2120 14

High-density lipoprotein (HDL) is classified as a negative risk factor due to the inverse relationship between elevated levels of HDL cholesterol and atherosclerosis. The mechanism by which HDL can mediate protection from atherosclerosis is complex and multifactorial. The primary role of reverse cholesterol transport in the reduction of risk for coronary artery disease is supported by a considerable amount of experimental data. HDL is able to interact with and remove cholesterol from the lipid-laden foam cells in the peripheral vasculature with subsequent transportation to the liver for excretion. However, HDL has multiple other physiologic effects that may play a significant role in protection from atherosclerosis. HDL has been demonstrated to exhibit multiple beneficial effects on the coagulation system. Platelet function is improved by both direct and indirect mechanisms. HDL has a complex interaction with the protein C and protein S system. Thrombolytic balance is also improved by HDL. HDL has been demonstrated to have a significant natural antioxidant effect that inhibits the oxidative step required for low-density lipoprotein uptake by the macrophage. Additionally, HDL has also been demonstrated to exert multiple beneficial effects on endothelial function, including decreased apoptosis and endothelial repair.
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PMID:Evolving concepts of the role of high-density lipoprotein in protection from atherosclerosis. 2138 Sep 38

The GAS6/ProS-TAM system is composed of two vitamin K-dependent ligands (GAS6 and protein S) and their three protein tyrosine kinase receptors TYRO3, AXL and MERTK, known as the TAM receptors. The system plays a prominent role in conditions of injury, inflammation and repair. In murine models of atherosclerotic plaque formation, mutations in its components affect atherosclerosis severity. Here we used Taqman low-density arrays and immunoblotting to study mRNA and protein expression of GAS6, ProS and the TAM receptors in human carotid arteries with different degrees of atherosclerosis. The results show a clear down-regulation of the expression of AXL in atheroma plaques with respect to normal carotids that is matched by decreased abundance of AXL in protein extracts detected by immunoblotting. A similar decrease was observed in PROS1 mRNA expression in atherosclerotic carotids compared to the normal ones, but in this case protein S (ProS) was clearly increased in protein extracts of carotid arteries with increasing grade of atherosclerosis, suggesting that ProS is carried into the plaque. MERTK was also increased in atherosclerotic carotid arteries with respect to the normal ones, suggesting that the ProS-MERTK axis is functional in advanced human atherosclerotic plaques. MERTK was expressed in macrophages, frequently in association with ProS, while ProS was abundant also in the necrotic core. Our data suggest that the ProS-MERTK ligand-receptor pair was active in advanced stages of atherosclerosis, while AXL signalling is probably down-regulated.
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PMID:Expression of the vitamin K-dependent proteins GAS6 and protein S and the TAM receptor tyrosine kinases in human atherosclerotic carotid plaques. 2138 80


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