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)

Increasing amounts of evidence support the involvement of inflammation and immunity in atherogenesis, but mediators of communication between the major cell types in atherosclerotic plaques are poorly defined. Cells in human atherosclerotic lesions express the immune mediator CD40 and its ligand CD40L (also known as CD154 or gp39). The interaction of CD40 with CD40L figures prominently in both humoral and cell-mediated immune responses. CD40L-positive T cells accumulate in atheroma, and, by virtue of their early appearance, persistence and localization at sites of lesion growth and complication, activated T cells may coordinate important aspects of atherogenesis. Interruption of CD40L-CD40 signalling by administration of an anti-CD40L antibody limits experimental autoimmune diseases such as collagen-induced arthritis, lupus nephritis, acute or chronic graft-versus-host disease, multiple sclerosis and thyroiditis. Ligation of CD40 on atheroma-associated cells in vitro activates functions related to atherogenesis, including induction of proinflammatory cytokines, matrix metalloproteinases, adhesion molecules and tissue factor. However, the role of CD40 signalling in atherogenesis in vivo remains unknown. Here we determine whether interruption of CD40 signalling influences atherogenesis in vivo in hyperlipidaemic mice. Treatment with antibody against mouse CD40L limited atherosclerosis in mice lacking the receptor for low-density lipoprotein that had been fed a high-cholesterol diet for 12 weeks. This antibody reduces the size of aortic atherosclerotic lesions by 59% and their lipid content by 79%. Furthermore, atheroma of mice treated with anti-CD40L antibody contained significantly fewer macrophages (64%) and T lymphocytes (70%), and exhibited decreased expression of vascular cell adhesion molecule-1. These data support the involvement of inflammatory pathways in atherosclerosis and indicate a role for CD40 signalling during atherogenesis in hyperlipidaemic mice.
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PMID:Reduction of atherosclerosis in mice by inhibition of CD40 signalling. 967 6

Atherosclerosis is one of the most prevalent fatal diseases in Western societies, and results from an intricate interplay between diverse factors such as lipid metabolism, blood coagulation elements, cytokines, hemodynamic stress, and behavioral risk factors. Atherosclerotic lesions are characterized by the infiltration of immune competent cells such as macrophages and T-lymphocytes, the proliferation of intimal cells of the arterial wall, the accumulation of lipids and the deposition of extracellular matrix components. For some years, endothelial cells, smooth muscle cells, and macrophages have been accorded crucial roles in the process of atherosclerosis. The mechanisms by which these cells contribute to atherosclerosis include augmented expression of adhesion molecules, as well as secretion of proinflammatory cytokines, matrix metalloproteinases, and tissue factor within human and experimental atheroma. Much evidence supports the role of tissue factor in inciting the thrombosis that causes most acute coronary syndromes. Macrophage content and expression of tissue factor correlate with rupture and instability of the atherosclerotic plaque. Matrix metalloproteinases can digest the plaque's extracellular matrix, and thus impair its stability. Plaque rupture exposes circulating blood components to the tissue factor-rich lipid-core, inciting thrombosis. Despite the increasing appreciation that atherogenesis involves participation of inflammatory pathways within cellular interactions, mediators of local communication between the major cell types within atherosclerotic plaques remain incompletely defined. By early appearance, activated T-cells may act as the orchestrator of atherogenesis. Both soluble and contact-dependent mediators from T-cells may be crucial in the development of this prevalent disease. Recent reports have helped explain some of these questions by pointing to a role of contact dependent interaction between CD40 and CD40 ligand (CD40L, renamed CD154) as a stimulus for atheroma-associated cells. We and others have recently showed that activated T-lymphocytes within the atherosclerotic vessel wall express the CD40 ligand surface molecule, known to play a major role in several immunological pathways. In addition to activated T-lymphocytes, functional CD40 and CD40L are coexpressed by human vascular endothelial cells, smooth muscle cells and human macrophages in vitro as well as in situ in human atherosclerotic lesions. Recent studies indicate that CD40L activates atheroma-associated cells by promoting the expression of molecules thought to be involved in atherosclerosis, such as adhesion molecules, cytokines, matrix metalloproteinases, and tissue factor. Thus, CD40 ligation on these vascular wall cells may promote mononuclear cell recruitment, participate in the weakening of the plaque and set the stage for thrombosis, mechanisms of crucial importance in the process of atherosclerosis. The involvement of the CD40 signaling pathway may play major roles during atherogenesis by regulating antigen-specific T-cell responses to yield activation instead of tolerance, and the presence of functional CD40L on non-leukocytic cells associated with atherosclerotic lesion indicates a novel T-cell-independent route of inflammatory activation, a now well recognized component of atherogenesis. These findings establish a possible crucial role for CD40-CD40L interactions in a prevalent human disease.
Atherosclerosis 1998 Apr
PMID:CD40 signaling in vascular cells: a key role in atherosclerosis? 969 47

Tissue factor is the primary cellular initiator of blood coagulation via interaction with coagulation factor VII. Aberrant expression of tissue factor is responsible for thrombosis during septic shock, atherosclerosis and cancer. However, recent evidence has accumulated that tissue factor may have functions beyond controlling fibrin-dependent hemostasis. It is expressed as an immediate early gene by growth factors and cytokines, it transduces intracellular signals via its cytosolic domain, triggers production of growth factors and has been implicated in immune function, smooth muscle migration and metastasis, the latter via mechanisms requiring intracellular signaling as well as the proteolytic activity of the tissue factor-factor VIIa complex. Further evidence for a possible alternative role of tissue factor has been provided from tissue factor gene inactivation studies, indicating that tissue factor controls vascular integrity by affecting the maturation of the muscular wall around endothelial cell lined channels. Surprisingly, however, deficiency of factor VII does not affect vascular integrity and tissue factor may act independently of fibrin formation during embryogenesis. Elucidation of the mechanism of its action may provide insights for selective interference with the hemostatic versus morphogenic properties of tissue factor.
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PMID:Tissue factor. 969 23

Tissue factor (TF) protein was overexpressed by macrophages and smooth muscle cells (SMCs) and deposited in the extracellular matrix of atherosclerotic intimas, probably resulting in enhanced procoagulant activity and the intimate participation in either thrombus formation or intimal fibrin deposition after the exposure of flowing blood and permeated fibrinogen to TF in atherosclerotic lesions. On the other hand, APO(a) was localized both in the stroma and within some macrophages. Fibrin deposition, which was more frequently detected in the matrix of advanced lesions than in that of early lesions, occasionally colocated with cell- and matrix-associated TF and APO(a) deposited in the matrix. These findings further support the hypothesis that the coagulation and fibrinolysis systems can play an essential role in the initiation and progression of atherosclerosis through fibrin deposition both in atherosclerotic plaques and on the arterial surface by neointimal hypercoagulability and a hypofibrinolytic state, which can also participate in SMC proliferation due to the decreased activation of TGF-beta by embedded and deposited APO(a). The clinical implications of these phenomena may thus contribute to future investigations in the prevention and treatment of atherosclerotic diseases.
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PMID:Atherosclerosis: coagulation and fibrinolysis. 970 57

Tissue factor (TF) is a primary initiator of the extrinsic pathway of blood coagulation. Recently TF has been shown to be overexpressed in atherosclerotic lesions and it is thought to contribute to the thrombogenicity of the plaques. We studied TF expression in the media and the neointima of rabbit aortas at various intervals after balloon injury. TF protein was immunohistochemically detected in smooth muscle cells (SMCs) of the inner layer of the media at 2 h after injury and was subsequently detected in SMCs in the neointima, whereas no TF expression was detected in the uninjured aortas except for the adventitia. Immunohistochemical and immunoelectron microscopic studies revealed that TF-positive SMCs were of an immature or synthetic phenotype and TF protein was detected in the rough endoplasmic reticulum in SMCs. TF mRNA in the intima and media increased at 2 h after injury and returned to near baseline levels at 12-24 h, whereas TF activity also increased at 2 h and continued at similar levels over the next 72 h. TF mRNA and activity increased markedly at 2-8 weeks after injury. These data suggest that TF is rapidly induced in the medial SMCs and hereafter is constitutively expressed in the neointima. TF expressed in the neointima may contribute to hypercoagulable properties of injured arteries.
Atherosclerosis 1998 Aug
PMID:Expression of tissue factor in the rabbit aorta after balloon injury. 971 32

Coagulation/fibrinolytic system and platelet function play roles not only in the onset of acute coronary syndrome (ACS) but also in the development of atherosclerosis, which is a major underlying condition of ACS. In this paper we reviewed the involvement of coagulation/fibrinolytic system and platelet in coronary atherosclerosis and ACS. It is well known that hyperchoresterolemia and diabetes mellitus (DM) are the important risk factor for coronary atherosclerosis and ACS. Both oxidized LDL and advanced glycation endproduct (AGE) activate endothelial cells with down-regulating thrombomodulin and tissue plasminogen activator(t-PA) expression. Moreover the oxidized LDL and AGE up-regulate the expression of tissue factor, and t-PA inhibitor, PAI-1. Thus Ox-LDL and AGE impair the endothelial antithrombotic function and result ACS. These may explain the pathomechanism of coronary sclerosis and ACS. In the atherosclerotic lesion with narrowing the lumen, high shear stress may be occurred. Recent observations suggested that high shear stress induces platelets aggregation named as shear stress induced platelet aggregation (SIPA), which may also have very important role for the pathogenesis in ACS.
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PMID:[Coagulation/fibrinolytic system and platelet in acute coronary syndrome]. 979 7

A review of the most important findings published during 1997 in cardiovascular papers is presented: Chlamydia pneumoniae was recognised as a potential risk factor for coronary artery disease (CAD) and possible pathogenic agent for valvular aortic stenosis. Valvular changes similar to the valvular disease reported after ergotamine and methylsergide were also detected in obese women treated with a combination of phentermine and fenfluramine. In CAD, several new laboratory methods were introduced for early diagnosis, such as serum troponin levels, and arbutamine and adenosine stress echocardiography. Laser transmyocardial revascularisation can be performed in patients unsuitable for PTCA and CABG. In patients with end-stage heart failure, implantable ventricular-assist devices can be used, and dynamic cardiomyoplasty or partial ventriculectomy may be useful temporary measures until a suitable heart donor is available. In pharmacotherapy, fluvastatin was registered as an antiatherosclerotic agent, and mibefradil and moxonidin in hypertension and angina. Digoxin was shown to reduce the number of hospitalisations in patients with CHF but still in sinus rhythm. In the future, several improvements in anti-thrombotic therapy are expected: antithrombins, platelet glycoprotein IIb/IIIa receptor blockers and tissue factor inhibitors are all potentially more potent than presently available drugs. Also, efforts are under way to introduce genes directly into the cells of the vascular wall to prevent atherosclerosis and restenosis, as well as to transform cardiac mesenchymal cells into the cardiac myocytes of hearts that have suffered large infarctions.
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PMID:[Cardiology in 1997]. 981 70

The expression of tissue factor (TF) by monocytes/macrophages leads to thrombin generation and contributes to their physiological and pathophysiological roles in wound repair, disseminated intravascular coagulation linked to sepsis, postoperative thrombosis, unstable angina, atherosclerosis, chronic inflammation and cancer. Regulation of TF expression in monocytes is controlled by the transcription factors NF-kappaB and AP-1. In whole blood, the activation of the transcription factors is mediated through the phospholipase A2 pathway. Platelets play a crucial role in the expression of TF activity in monocytes, and granulocytes are mandatory in provoking the platelet effect in a P-selectin-dependent reaction. Although all induced or constitutive TF is expressed on the surface of monocytes, its catalytic activity is only about 10% compared to the activity of lysed cells. This phenomenon has been attributed to the increased availability of anionic phospholipid (phosphatidylserine) after cell lysis. At the surface of viable cells, the transmembrane phospholipid distribution and its regulation may be important for the expression of the catalytic activity of the complex of TF and activated factor VII. Phosphatidylserine pathophysiologically exposed at the outer surface of monocytes may, similar to that for platelet membranes, provide a strong stimulus for thrombin generation.
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PMID:Tissue factor expression by monocytes: regulation and pathophysiological roles. 981 23

An in vitro model consisting of endothelium grown on collagen was used to investigate how mononuclear phagocytes traverse endothelium in the basal-to-apical direction (reverse transmigration), a process that mimics their migration across vascular and/or lymphatic endothelium during atherosclerosis and resolution of inflammation, respectively. Monoclonal antibody (MoAb) VIC7 against tissue factor (TF) inhibited reverse transmigration by 77%. Recombinant tissue factor fragments containing at least six amino acids C-terminal to residue 202 also strongly inhibited reverse transmigration. TF was absent on resting monocytes but was induced on these cells after initial apical-to-basal transendothelial migration. Two additional observations suggest that TF is involved in adhesion between mononuclear phagocytes and endothelium: (1) when monocytes were incubated with lipopolysaccharide (LPS) to stimulate expression of TF before they were added to endothelium, VIC7 or soluble TF modestly inhibited their adhesion to the apical endothelial surface, each by about 35%; and (2) endothelial cells specifically bound to surfaces coated with TF fragments containing amino acids 202-219. This binding was blocked by anti-TF MoAb, suggesting that endothelial cells bear a receptor for TF. These data suggest that mononuclear phagocytes use TF, perhaps as an adhesive protein, to exit sites of inflammation.
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PMID:Role of tissue factor in adhesion of mononuclear phagocytes to and trafficking through endothelium in vitro. 983 21

Atherosclerotic plaque rupture and erosions precipitate thrombus formation and may lead to an acute ischemic syndrome. Lipids and lipoproteins modulate the expression and/or function of thrombotic, fibrinolytic and rheologic factors, and thereby influence hemostasis and potential tissue damage resulting from vascular injury. Triglyceride-enriched lipoproteins are accompanied by elevations in factor VII clotting activity, plasminogen activator inhibitor (PAI-1) and viscosity of blood and plasma. Low density lipoprotein (LDL) promotes platelet activation and tissue factor expression and LDL levels correlate with levels of vitamin K dependent coagulation factors and fibrinogen. Conversely, LDL inhibits tissue factor pathway inhibitor (TFPI) which limits activation of the extrinsic coagulation pathway. High density lipoprotein (HDL) has anti-atherothrombotic properties that result from inhibition of platelet and erythrocyte aggregation, reduced blood viscosity and suppression of tissue factor activity and PAI-1 activity and antigen levels. The effects of lipids and lipoproteins on hemostasis and rheology may have important implications for the clinical sequelae following plaque disruption and erosion.
Atherosclerosis 1998 Oct
PMID:Effects of lipids and lipoproteins on thrombosis and rheology. 986 70


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