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

Atherosclerosis being considered as an inflammatory disorder, the present study was undertaken to investigate the effectiveness of anti-inflammatory drugs (ibuprofen, aspirin, and celecoxib) in hypercholesterolemia. Ibuprofen is a cyclooxygenase (COX-1 and COX-2) inhibitor known to reduce the production of prostaglandins that play prominent role in inflammation. Beside the anti-inflammatory effects that make ibuprofen interesting for the treatment of condition associated with hypercholesterolemic atherosclerosis. Various other properties of ibuprofen were investigated, ibuprofen showed better reduction in total cholesterol, triglycerides, very low density lipo-protein, low density lipo-protein and atherogenic index than aspirin and celecoxib in hypercholesterolemic animals. These properties of ibuprofen may be due to inhibition of acetyl-CoA carboxylase initiating the synthesis of fatty acids. Ibuprofen significantly elevated antioxidant (super oxide dismutase; catalase) levels and reduced lipid peroxidation. Ibuprofen inhibits COX enzymes and thereby inhibits generation of free radicals during prostaglandins synthesis, which may be responsible for reduction in lipid peroxidation, super oxide dismutase levels and for high catalase levels. Interestingly, ibuprofen decreased total leukocyte count, monocyte count, erythrocyte sedimentation rate and C-reactive protein levels. From the results of present study, it can be concluded that ibuprofen (non-selective COX inhibitor) showed promising antihyperlipidemic, antiatherosclerotic, antioxidant, antiinflammatory and non-ulcerogenic activity in atherosclerotic animals as compared to aspirin (preferential COX-1 inhibitor) and celecoxib (selective COX-2 inhibitors, suggesting the inducible role of COX in atherosclerosis.
 ...
PMID:Antiatherosclerotic activity of ibuprofen, a non-selective COX inhibitor--an animal study. 1869 8

Hyaluronan (HA) is a key molecule of the extracellular matrix that is thought to be critically involved in both atherosclerosis and restenosis. Recently, it has been demonstrated that the cyclooxygenase (COX) products, prostacyclin and prostaglandin E(2), induce HA synthesis in vitro by transcriptional up-regulation of HA-synthase 2 (HAS2) and HAS1. The relative roles in atherosclerotic and restenotic artery disease of tissue specifically expressed COX-1 and COX-2 are still under debate. Thus, the present study aimed to investigate the effect of COX isoform inhibition on HA-accumulation and regulation of HAS isoform expression in two models of pathologic artery remodelling in vivo. Firstly, ApoE-deficient mice were treated with a prototypic isoform non-selective inhibitor, indomethacin or with a prototypic COX-2 selective inhibitor, rofecoxib, for 8 weeks. Aortic HAS mRNA expression and HA-accumulation in atherosclerotic aortic root lesions were analyzed. Secondly, neointimal hyperplasia was induced by carotid artery ligation in ApoE-deficient mice on a high fat diet and the effects of the COX inhibitors were determined after 4 weeks of treatment. Intimal HA-accumulation was markedly reduced in both models by indomethacin and rofecoxib. This coincided with a strong inhibition of HAS1 mRNA expression in both models and with decreased HAS2 mRNA in the aorta of ApoE-deficient mice. HAS3 was not affected. The repression of HA-accumulation by both COX-2 selective and non-selective COX inhibition implicates COX-2 in the regulation of HA synthesis via stimulation of HAS1 and HAS2 expression in vivo. Modulation of vascular HA-accumulation might play a role in chronic effects of COX inhibitors on the progression of atherosclerosis.
 ...
PMID:Cyclooxygenase inhibitors repress vascular hyaluronan-synthesis in murine atherosclerosis and neointimal thickening. 1932 Jul 76

Fenofibrate, a lipid-lowering drug, inhibits hydroxyl-methylglutaryl coenzyme A (HMG-CoA)-reductase activity, thus reducing cholesterol synthesis and increasing the clearance of circulating LDL-cholesterol via the high affinity receptor system. In addition, fenofibrate has beneficial effects such as the inhibition of tissue factor expression, antithrombotic effect and anti-inflammatory effect. The aim of this study was to investigate the effects of fenofibrate on thrombus formation in vivo and platelet activation in vitro and ex vivo. The carotid arteries of male Sprague-Dawley rats were subjected to chemical injury by FeCl(3), and then blood flow was measured with a blood flowmeter. Fenofibrate (200 and 400mg/kg/day for 1 week) delayed the time to occlusion by 61.3% (p<0.05, n=10) and 90.7% (p<0.01, n=10), respectively. Fenofibrate also significantly inhibited ex vivo platelet aggregations induced by collagen (7.5microg/ml) (p<0.01, n=11) and ADP (10microM) (p<0.01, n=11), respectively, but did not affect coagulation times following activated partial thromboplastin and prothrombin activation, indicating the antithrombotic effect was mediated by its inhibition on platelet activation rather than coagulation system. This antiplatelet activity was revealed to be mediated by the suppression of thromboxane A(2) receptor, cytosolic calcium mobilization, and cyclooxygenase (COX)-1 activity. Taken together, we demonstrate that fenofibrate can significantly inhibit artery thrombus formation in vivo, which may be due to antiplatelet activity via the inhibition of thromboxane A(2) receptor, cytosolic calcium mobilization and COX-1 activity, and the beneficial effect of fenofibrate on cardiovascular system may be also due to its modulation of platelet activation.
Atherosclerosis 2009 Oct
PMID:Antithrombotic and antiplatelet activities of fenofibrate, a lipid-lowering drug. 1934 49

Lipoxygenase (LO) enzymes catalyze the conversion of arachidonic acid (AA) into biologically active lipid mediators. Two members, 12/15-LO and 5-LO, regulate inflammatory responses and have been studied for their roles in atherogenesis. Both 12/15-LO and 5-LO inhibitors have been suggested as potential therapy to limit the development of atherosclerotic lesions. Here we used a genetic strategy to disrupt both 12/15-LO and 5-LO on an apolipoprotein E (apoE) atherosclerosis-susceptible background to study the impact of dual LO blockade in atherosclerosis and inflammation. Resident peritoneal macrophages are the major cell type that expresses both LO enzymes, and we verified their absence in dual LO-deficient mice. Examination of AA conversion by phorbol myristate acetate-primed and A23187-challenged macrophages from dual LO-deficient mice revealed extensive accumulation of AA with virtually no diversion into the most common cyclooxygenase (COX) products measured (prostaglandin E2 and thromboxane B2). Instead the COX-1 by-products 11-hydroxy-eicosatetraenoic acid (HETE) and 15-HETE were elevated. The interrelationship between the two LO pathways in combination with COX-1 inhibition (SC-560) also revealed striking patterns of unique substrate utilization. 5-LO- and dual LO-deficient mice exhibited an attenuated response to zymosan-induced peritoneal inflammation, emphasizing roles for 5-LO in regulating vascular permeability. We observed gender-specific attenuation of atheroma formation at 6 months of age at both the aortic root and throughout the entire aorta in chow-fed female dual LO-deficient mice. We propose that some of the inconsistent data obtained with single LO-deficient mice could be attributable to macrophage-specific patterns of altered AA metabolism.
 ...
PMID:Dual 12/15- and 5-lipoxygenase deficiency in macrophages alters arachidonic acid metabolism and attenuates peritonitis and atherosclerosis in ApoE knock-out mice. 1950 98

Dissolved organic matter (DOM) in seawater can be defined as the fraction of organic matter that passes through a filter of sub micron pore size. In this study, we have examined the effect of DOM of deep seawater (DSW) from Pacific Ocean on platelet aggregation and atherosclerosis progression. DSW was passed through a series of filters and then through an Octadecyl C18 filter; the retained substance in ethanol was designated as C18 extractable DOM (C18-DOM). Our studies showed that C18-DOM treatment inhibited platelet aggregation, P-selectin expression and activity of COX-1 significantly. C18-DOM increased the expression of anti-atherogenic molecule namely heme oxygenase-1 in endothelial cells and all these data showed that C18-DOM is exhibiting aspirin-like effects. Moreover our in vivo studies showed that C18-DOM feeding slowed remarkably the progression of atherosclerosis. Our study demonstrated a novel biological effect of oceanic DOM, which has several important implications, including a possible therapeutic strategy for atherosclerosis.
 ...
PMID:Intake of dissolved organic matter from deep seawater inhibits atherosclerosis progression. 1954 Jan 94

The 12/15-lipoxygenase (LO) cascade governs the generation of 12-hydroperoxy-eicosatetraenoic acid (HPETE) and 15-HPETE from arachidonic acid. The 5-LO pathway plays a fundamental role in the biosynthesis of leukotrienes, essential inflammatory lipid mediators. Cyclooxygenase (COX)-1 and -2 biosynthetic pathways are responsible for prostaglandin and thromboxane formation. Experimental investigations in animal models using 12/15-LO deficient mice, 12/15-LO or 15-LO transgenic mice, or pharmacological 15-LO inhibition have all demonstrated the essential role of 12/15-LO in atherogenesis. The underlying mechanisms are linked to low-density lipoprotein oxidation, pro-inflammatory Th1 cytokine production and enhanced monocyte-endothelial cell interaction. Human genetic studies as well as disruption of the 5-LO gene in mouse models of hyperlipidemia revealed that 5-LO and 5-LO-activating protein are associated with risks of human cardiovascular disease, and that this cascade plays an important role in aortic aneurysm pathogenesis through leukotriene-mediated inflammatory chemokine production. COX-1 plays an active role in atherogenesis via thromboxane A(2), while COX-2-derived prostaglandin (PGI(2)) protects against atherosclerosis in murine models. Recent data demonstrated that selective inhibition of COX-2 augments the risk of cardiovascular events in patients. Selective inhibition or blockade of selective components in these two enzymatic pathways through systemic drug delivery or medical device approaches (e.g., drug-eluting stents) may have therapeutic benefit against certain cardiovascular diseases.
 ...
PMID:Lipoxygenase and prostaglandin G/H synthase cascades in cardiovascular disease. 2047 20

Chronic smoking is associated with functional and structural vascular changes underlying inflammatory processes responsible for plaque formation and rupture. Cyclooxygenase (COX) is the key enzyme linking smoking action to inflammatory damages: it is responsible for the conversion of arachidonic acid to prostanoids, and lipid mediators involved in most of pathological processes. Two COX isoenzymes have been characterized, COX-1 and COX-2, that differ in terms of regulatory mechanisms of expression, tissue distribution, substrate specificity, and preferential coupling to upstream and downstream enzymes. The aim of this review is to highlight the pathogenetic role of chronic smoking in vasomotor dysfunction, inflammation, and modification of lipids underlying the initiation and the progression of atherosclerosis and to remark the hypothesis that plaque composition rather than plaque size is the real determinant of the plaque evolution toward rupture and the major responsible for acute ischemic syndromes. The concomitantly higher expression of EP4, COX-2, mPGES-1, MMP-2 and MMP-9 in unstable plaques is focused and the role of PGE(2) as pathophysiological link between smoking, COX-2 and MMP activity is stressed. Indeed, the intracellular pathways regulating COX-2 and the mechanisms suggested to clarify the role of COX-2 and downstream synthases in atherothrombosis are summarized.
 ...
PMID:Cyclooxygenase and atherosclerosis: a smoking area. 2055 May

Atherosclerosis and its clinical manifestations (i.e. myocardial infarction, stroke) are major causes of mortality and morbidity in Western countries. Endothelial dysfunction is considered the first step in the cascade leading up to coronary events. Increasing evidence suggests that direct inhibition of thromboxane A2/prostaglandin (TP)-receptors may not only have anti-platelet effects but also impact endothelial dysfunction as well as inflammatory component of atherosclerosis. While TP-receptor involvement in platelet function has received the greatest attention, more recent findings support the critical role of TP-receptor in other pathophysiological aspects of atherothrombosis. Prostanoids (i.e. TxA2, F2-isoprostanes, prostaglandins endoperoxides PGG2/PGH2) are known to promote the initiation and progression of atherosclerosis, not only via platelet activation, but through leukocyte-endothelial interactions and vasoconstriction. Dysfunctional endothelium, characterised by increased COX-activity, releases prostanoids that promote endothelial exposure to adhesion molecules and induce smooth muscle cell contraction. Plaque macrophages synthesise PGH2/PGG2 via COX-2; these potent prostanoids can trigger platelet activation and aggregation despite COX-1 inhibition by aspirin. TP-receptor inhibition has been reported to exert anti-atherosclerotic effects in pre-clinical model of disease. Reduction of plaque burden was associated with plaque stabilisation documented by the reduction in the content of macrophages, apoptotic cells, MMPs and endothelin-1, and the increase in smooth muscle cells content. TP-receptor blockade might have an anti-atherosclerotic and plaque stabilisation effect. The possibility of combining anti-platelet activity with an anti-atherosclerotic effect via selective TP-receptor inhibitors could have important implications especially in clinical conditions associated with increased production of prostanoids, such as diabetes.
 ...
PMID:Prostanoid and TP-receptors in atherothrombosis: is there a role for their antagonism? 2088 80

Obesity and metabolic syndrome increase the risk of coronary heart disease and lead to a proinflammatory state of the vascular wall. Endothelial dysfunction is associated with up-regulation of cyclooxygenase-2 (COX-2) and enhanced synthesis of constrictor prostaglandins in systemic arteries in diabetes. The present study assessed whether changes in the arachidonic acid (AA) metabolism via COX-1 and COX-2 may affect endothelial function of coronary arteries in obesity. Intramyocardial arteries from obese Zucker rats (OZR) and from lean Zucker rats (LZR) were mounted in microvascular myographs to assess vascular function and COX expression was determined by both immunohistochemistry and Western blot. AA elicited relaxations of similar magnitude in arteries from LZR and OZR which were abolished by endothelial cell removal. Selective inhibition of COX-1 enhanced the AA relaxant responses and inhibited the 5-hydroxytryptamine (5-HT)-induced vasoconstriction in arteries from both LZR and OZR. Antagonism of the TXA(2)/PGH(2) (TP) receptor mimicked the effects of COX-1 blockade in arteries from LZR but not OZR. Selective inhibition of COX-2 markedly reduced the vasodilatation induced by AA in OZR, but not in LZR, without altering 5-HT or ACh responses. COX-1 was widely distributed throughout the endothelial layer of coronary arteries from both LZR and OZR, while COX-2 protein, which was predominantly expressed in the endothelium, was significantly increased in arteries from OZR. Whereas AA is mainly metabolised to vasoconstrictor prostanoids via COX-1 in coronary arteries from healthy animals, endothelial COX-2 is up-regulated to produce vasodilator prostaglandins thus protecting coronary arteries in insulin resistant obese rats.
Atherosclerosis 2010 Dec
PMID:Enhanced cyclooxygenase 2-mediated vasorelaxation in coronary arteries from insulin-resistant obese Zucker rats. 2095 3

Cardiovascular disease is the foremost cause of morbidity and mortality in the Western world. Atherosclerosis followed by thrombosis (atherothrombosis) is the pathological process underlying most myocardial, cerebral, and peripheral vascular events. Atherothrombosis is a complex and heterogeneous inflammatory process that involves interactions between many cell types (including vascular smooth muscle cells, endothelial cells, macrophages, and platelets) and processes (including migration, proliferation, and activation). Despite a wealth of knowledge from many recent studies using knockout mouse and human genetic studies (GWAS and candidate approach) identifying genes and proteins directly involved in these processes, traditional cardiovascular risk factors (hyperlipidemia, hypertension, smoking, diabetes mellitus, sex, and age) remain the most useful predictor of disease. Eicosanoids (20 carbon polyunsaturated fatty acid derivatives of arachidonic acid and other essential fatty acids) are emerging as important regulators of cardiovascular disease processes. Drugs indirectly modulating these signals, including COX-1/COX-2 inhibitors, have proven to play major roles in the atherothrombotic process. However, the complexity of their roles and regulation by opposing eicosanoid signaling, have contributed to the lack of therapies directed at the eicosanoid receptors themselves. This is likely to change, as our understanding of the structure, signaling, and function of the eicosanoid receptors improves. Indeed, a major advance is emerging from the characterization of dysfunctional naturally occurring mutations of the eicosanoid receptors. In light of the proven and continuing importance of risk factors, we have elected to focus on the relationship between eicosanoids and cardiovascular risk factors.
 ...
PMID:An eicosanoid-centric view of atherothrombotic risk factors. 2249 20


<< Previous 1 2 3 4 5 6 7 Next >>