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)

Vascular smooth muscle cell (VSMC) migration from media to intima and its multiplication in intima is a contributing factor in the pathogenesis of atherosclerosis and restenosis after angioplasty. Previously, we have demonstrated that STAT-3-dependent cytosolic phospholipase A(2) (cPLA(2)) expression is needed for VSMC motility induced by platelet-derived growth factor-BB, a receptor tyrosine kinase agonist (Neeli et al. (2005) J. Biol. Chem. 279, 46122-46128). In order to learn more about the STAT-3-cPLA(2) axis in motogenic signaling, here we have studied its role in VSMC motility in response to a G protein-coupled receptor (GPCR) agonist, thrombin. Thrombin induced VSMC motility in a dose-dependent manner with a maximum effect at 0.5 units/ml. Thrombin activated STAT-3 as measured by its tyrosine phosphorylation and translocation from the cytoplasm to the nucleus. Forced expression of a dominant negative mutant of STAT-3 reduced thrombin-induced STAT-3 tyrosine phosphorylation and its translocation from the cytoplasm to the nucleus. Thrombin stimulated STAT-3-DNA binding and reporter gene activities in VSMC, and these responses were blocked by FS3DM, a dominant negative mutant of STAT-3. FS3DM also attenuated thrombin-induced VSMC motility. Thrombin induced the expression of cPLA(2) in a time- and STAT-3-dependent manner. In addition, pharmacological inhibition of cPLA(2) blocked thrombin-induced VSMC motility. Furthermore, exogenous addition of arachidonic acid rescued thrombin-induced VSMC motility from inhibition by blockade of STAT-3 activation. Forced expression of cPLA(2) also surpassed the inhibitory effect of dominant negative STAT-3 on thrombin-induced VSMC motility. Together, these results show that thrombin-induced VSMC motility requires STAT-3-dependent induction of expression of cPLA(2).
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PMID:STAT-3-dependent cytosolic phospholipase A2 expression is required for thrombin-induced vascular smooth muscle cell motility. 1554 19

Serine proteases are attractive targets for the design of enzyme inhibitors since they are involved in the etiology of several diseases. Within the class of serine proteases, HLE is one of the most destructive enzymes in the body. It is implicated in the promotion or exacerbation of a number of diseases including pancreatitis, acute respiratory syndrome, rheumatoid arthritis, atherosclerosis, pulmonary emphysema, and cystic fibrosis. Thrombin, a trypsin-like serine protease, plays a dual role in thrombogenesis, including fibrin formation and platelet activation. As a result, thrombin constitutes one of the most widely studied targets for antithrombotic strategy. Numerous inhibitors of serine proteases have been reported during the past three decades. Among them, coumarin-type molecules displayed a high inhibitory potency towards various serine proteases. At that time, halomethyl dihydrocoumarins have been shown to behave as the first general suicide inhibitors of serine protease. These molecules inhibit several proteases such as human leucocyte elastase, porcine pancreatic elastase, thrombin, urokinase and human plasmin. Isocoumarins are very effective as mechanism-based inhibitors of serine proteases. Pharmacomodulation on the 3-alkoxy-4-chloroisocoumarins and the 3-alkoxy-7-amino-4-chloroisocoumarins led to strong inhibitors of numerous serine proteases such as HLE, human factor XIa and XIIa, thrombin, urokinase and kallikrein. Recently, a series of coumarins characterised by an alkyl, aryl ester, amide, thioester or ketone in the position 3 and an electrophilic chloromethyl moiety in the position 6 have been developed. These compounds were found to be high inhibitors of alpha-chymotrypin, HLE and human thrombin.
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PMID:Coumarin and isocoumarin as serine protease inhibitors. 1557 71

Thrombospondin-1 (THBS1) is a large extracellular matrix glycoprotein that affects vasculature systems such as platelet activation, angiogenesis, and wound healing. Increases in THBS1 expression have been liked to disease states including tumor progression, atherosclerosis, and arthritis. The present study focuses on the effects of thrombin activation of the G-protein-coupled, protease-activated receptor-1 (PAR-1) on THBS1 gene expression in the microvascular endothelium. Thrombin-induced changes in gene expression were characterized by microarray analysis of approximately 11,000 different human genes in human microvascular endothelial cells (HMEC-1). Thrombin induced the expression of a set of at least 65 genes including THBS1. Changes in THBS1 mRNA correlated with an increase in the extracellular THBS1 protein concentration. The PAR-1-specific agonist peptide (TFLLRNK-PDK) mimicked thrombin stimulation of THBS1 expression, suggesting that thrombin signaling is through PAR-1. Further studies showed THBS1 expression was sensitive to pertussis toxin and protein kinase C inhibition indicating G(i/o)- and G(q)-mediated pathways. THBS1 up-regulation was also confirmed in human umbilical vein endothelial cells stimulated with thrombin. Analysis of the promoter region of THBS1 and other genes of similar expression profile identified from the microarray predicted an EBOX/EGRF transcription model. Expression of members of each family, MYC and EGR1, respectively, correlated with THBS1 expression. These results suggest thrombin formed at sites of vascular injury increases THBS1 expression into the extracellular matrix via activation of a PAR-1, G(i/o), G(q), EBOX/EGRF-signaling cascade, elucidating regulatory points that may play a role in increased THBS1 expression in disease states.
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PMID:Thrombin modulates the expression of a set of genes including thrombospondin-1 in human microvascular endothelial cells. 1581 47

Thrombin is a mitogen for vascular smooth muscle cells (VSMC) and has been implicated in the development in atherosclerosis. However, little is known about the role of thrombin in glucose transport in VSMC. In this study, we examined the effect of thrombin on glucose uptake in rat A10 VSMC. We found that thrombin induced glucose uptake in a dose-dependent manner while hirudin, a potent thrombin inhibitor, prevented glucose uptake in the cells. PP2, a selective inhibitor of Src, prevented the thrombin-induced glucose uptake, but did not affect insulin-induced uptake. We also examined whether mitogen-activated protein kinase (MAPK) inhibitors influenced thrombin-induced glucose uptake. The p38 MAPK inhibitor (SB203580) inhibited thrombin-induced glucose uptake, but the MEK inhibitor (PD98059) did not. In contrast to thrombin, SB203580 did not affect insulin-induced glucose uptake. Furthermore, thrombin failed to translocate the insulin-sensitive glucose transporter GLUT4. These findings suggest that thrombin stimulates glucose transport via Src and subsequent p38 MAPK activation in VSMC.
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PMID:Thrombin-induced glucose transport via Src-p38 MAPK pathway in vascular smooth muscle cells. 1595 27

Endothelial membrane-bound thrombomodulin is a high affinity receptor for thrombin to inhibit coagulation. We previously demonstrated that the thrombin-thrombomodulin complex restrains cell proliferation mediated through protease-activated receptor (PAR)-1. We have now tested the hypothesis that thrombomodulin transduces a signal to activate the endothelial nitric-oxide synthase (NOS3) and to modulate G protein-coupled receptor signaling. Cultured human umbilical vein endothelial cells were stimulated with thrombin or a mutant of thrombin that binds to thrombomodulin and has no catalytic activity on PAR-1. Thrombin and its mutant dose dependently activated NO release at cell surface. Pretreatment with anti-thrombomodulin antibody suppressed NO response to the mutant and to low thrombin concentration and reduced by half response to high concentration. Thrombin receptor-activating peptide that only activates PAR-1 and high thrombin concentration induced marked biphasic Ca2+ signals with rapid phosphorylation of PLC(beta3) and NOS3 at both serine 1177 and threonine 495. The mutant thrombin evoked a Ca2+ spark and progressive phosphorylation of Src family kinases at tyrosine 416 and NOS3 only at threonine 495. It activated rapid phosphatidylinositol-3 kinase-dependent NO synthesis and phosphorylation of epidermal growth factor receptor and calmodulin kinase II. Complete epidermal growth factor receptor inhibition only partly reduced the activation of phospholipase Cgamma1 and NOS3. Prestimulation of thrombomodulin did not affect NO release but reduced Ca2+ responses to thrombin and histamine, suggesting cross-talks between thrombomodulin and G protein-coupled receptors. This is the first demonstration of an outside-in signal mediated by the cell surface thrombomodulin receptor to activate NOS3 through tyrosine kinase-dependent pathway. This signaling may contribute to thrombomodulin function in thrombosis, inflammation, and atherosclerosis.
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PMID:Endothelial thrombomodulin induces Ca2+ signals and nitric oxide synthesis through epidermal growth factor receptor kinase and calmodulin kinase II. 1612 27

Kidney transplant recipients are prone to hypertension, dyslipidemia, and cardiovascular death. Hypertension is associated with hemostatic abnormalities. Thrombin activatable fibrinolysis inhibitor (TAFI) is a glycoprotein that links coagulation and fibrinolysis. The purpose of this study was to assess TAFI concentrations in renal transplant recipients in relation to blood pressure. Additionally, we evaluated thrombin activity (thrombin-antithrombin complex [TAT], prothrombin fragments 1+2 [F1+2]), thrombomodulin (TM), and the degree of plasmin generation (plasmin-antiplasmin complex [PAP]) using commercially available kits. The studies were performed on 86 renal allograft recipients (48 women, 38 men) at age range 26 to 73 years. The immunosuppressive regimen consisted of cyclosporine (CsA), prednisone, and azathioprine (n = 58) or mycophenolate mofetil (MMF; n = 28). All patients maintained sufficient and stable graft function, showing no clinical signs of rejection. In patients with hypertension (n = 68), we observed significantly higher concentrations of TAFI and of markers of thrombin generation (F1+2, TAT), and of thrombomodulin with significantly prolonged euglobulin clot lysis time (ECLT), which reflects overall fibrinolytic activity and lower fibrinolytic activity index (FAI). Both groups did not differ with respect to age, creatinine clearance, body mass index, time after transplantation, albumin, fibrinogen, and PAP. Diastolic blood pressure correlated significantly with TAFI concentrations, uric acid, and prednisone dose, whereas systolic blood pressure correlated with urea, uric acid, creatinine clearance, and MCV. Elevated TAFI concentrations and enhanced thrombin generation in hypertensive kidney transplant recipients may contribute to the hypofibrinolysis and progressive atherosclerosis in this population. Blood pressure was related to kidney function, maintenance prednisone dose, and TAFI concentration.
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PMID:Thrombin activatable fibrinolysis inhibitor in hypertensive kidney transplant recipients. 1650 76

Thrombin is a crucial enzyme in blood coagulation cascade having both pro- and antithrombotic properties. Disorders of hemostatic balance increase possibility of clot formation and play significant role in the development of atherosclerosis. Statins applied in prevention of cardiovascular diseases, have not only hypolipemic activity but also many pleiotropic effects. The aim of this study was to evaluate the level of thrombin generation and clot bound thrombin in patients with hyperlipidemia type II (hlpII) before and after statins treatment. 81 patients were involved in this study: 59 patients with hlp II and 22 healthy. Patients with hlp II were treated with pravastatin (20 mg/day; n=10), simvastatin (20 mg/day; n=22), atorvastatin (10 mg/day; n=27). The treatment in each of groups lasted 8 weeks. Thrombin generation and clot bound thrombin level were estimated before and after therapy by means of spectrophotometric method with usage of chromogenic substrate S-2238. Our results demonstrate that therapy with atorva- simva- and pravastatin improves lipid levels in plasma and investigated hemostasis parameters. All three statins statistically significantly decrease total generated thrombin. Atorva- and simvastatin also significantly decrease activity both free generated thrombin and clot bound thrombin. No correlation between lipidogram and hemostatic parameters after treatment with statins suggests that observed changes are pleiotropic effect of statins treatment.
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PMID:[Evaluation of thrombin generation and clot bound thrombin in plasma of hyperlipidemic patients treated with statins]. 1652 18

Thrombin stimulation of human coronary artery endothelial cells (HCAEC) results in activation of a membrane-associated, calcium-independent phospholipase A(2) (iPLA(2)) that selectively hydrolyzes membrane plasmalogen phospholipids. Rupture of an atherosclerotic plaque and occlusion of the coronary vasculature results in a coronary ischemic event in which HCAEC in the ischemic area would be exposed to dramatic decreases in oxygen tension in addition to thrombin exposure. We exposed HCAEC to hypoxia in the presence or absence of thrombin stimulation and measured iPLA(2) activation, membrane phospholipid hydrolysis, and the accumulation of biologically active phospholipid metabolites. HCAEC exposed to hypoxia, thrombin stimulation, or a combination of the two conditions demonstrated an increase in iPLA(2) activity and an increase in arachidonic acid release from plasmenylcholine. Thrombin stimulation of normoxic HCAEC did not result in an accumulation of choline lysophospholipids, but hypoxia alone and in combination with thrombin stimulation led to a significant accumulation of lysoplasmenylcholine (LPlsCho). We propose that the presence of hypoxia inhibits LPlsCho catabolism, at least in part, as a result of the accumulation of long-chain acylcarnitines. The combination of increased production and decreased catabolism of LPlsCho is necessary for its accumulation. Pretreatment with bromoenol lactone to inhibit iPLA(2) blocked membrane phospholipid hydrolysis and production of membrane phospholipid-derived metabolites. The increase in iPLA(2) activity and the subsequent accumulation of membrane phospholipid-derived metabolites in HCAEC exposed to hypoxia or thrombin stimulation alone, and particularly in combination, have important implications in inflammation and arrhythmogenesis in atherosclerosis/thrombosis and subsequent myocardial ischemia.
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PMID:Calcium-independent phospholipase A2-catalyzed plasmalogen hydrolysis in hypoxic human coronary artery endothelial cells. 1694 48

To assess the existence of endothelial dysfunction and the possibility of the early onset of atherosclerosis in the chronic stage of Kawasaki disease (KD), we examined endothelial function in adult patients late after the onset of KD. We evaluated two age-matched groups: 35 adult KD patients (KD group) (mean age, 27.0 years; mean interval time, 24.1 years), and 36 healthy adults (control group). To assess vascular endothelial function, flow-mediated dilatation (%FMD) of the brachial artery and urinary nitrites and nitrates (NOx) were examined. We also measured adhesion molecules and several coagulation-fibrinolysis markers. In addition, we measured high-sensitive C-reactive protein (hs-CRP) as a chronic inflammatory marker, and brachial-ankle pulse wave velocity (baPWV) as a marker for arterial stiffness. %FMD was significantly reduced in the KD group when compared with that of the control group (KD group, 10.4 +/- 2.6%; control group, 14.4 +/- 3.2%, p<0.05), particularly in patients with coronary artery lesions. Thrombin-antithrombin III complex values were higher in the KD group, although no significant differences were observed in the other markers for endothelial function. Hs-CRP was significantly elevated only in the patients with coronary aneurysms. Furthermore, in the male KD patients, the baPWV values were significantly higher than those in the control subjects. This study revealed that the adult patients with a history of KD had systemic vascular endothelial dysfunction, and also suggested that a history of KD was possibly one of the risk factors for early onset of atherosclerosis.
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PMID:Endothelial dysfunction in adult patients with a history of Kawasaki disease. 1734 94

Adverse cardiovascular events are the consequence of a molecular chain reaction at the site of vulnerable plaques. Key players are platelets and coagulation factors that are activated following plaque rupture and often cause arterial obstruction. Thrombin, a plasma serine protease, plays a role in hemostasis of coagulation as well as in thrombosis and cell growth, leading to restenosis and atherosclerosis. Interesting and promising new molecules, the direct thrombin inhibitors, have been shown to be as effective as the combination of glycoprotein IIb-IIIa inhibitors and heparin for the prevention of arterial thrombosis. Until recently, direct thrombin inhibitors could be applied only parenterally; therefore, therapy was limited to hospitalized patients. As a result of recent drug development, orally active direct thrombin inhibitors are now available and have been evaluated for the long-term treatment of venous thrombosis and arterial fibrillation. Due to their specific pharmacodynamic characteristics by binding directly to thrombin--and thus inhibiting platelet aggregation and fibrin generation--these novel drugs may also have therapeutic potential for the treatment of atherothrombotic disease and its complications such as myocardial infarction, stroke or limb ischemia.
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PMID:Therapeutical potential of direct thrombin inhibitors for atherosclerotic vascular disease. 1746 31


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