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)

Metabolic syndrome (MS) is characterized by the presence of at least three of the following alterations: enlargement of the waist diameter, higher levels of arterial pressure, low density lipoprotein cholesterol and glycemia, and reduction of high density lipoprotein cholesterol. The prevalence of MS reaches 23% in young adults, a percentage that increases with age. People with MS have a greater risk of suffering from cardiovascular disease (CVD). The physiopathologic alterations now found to exist in MS are diverse; among them is endothelial dysfunction, which triggers atherogenic lesions and hypercoagulability characterized by alterations of the coagulation factors and the regulatory proteins of fibrinolysis such as the plasminogen activator inhibitor (PAI-1). The increase in oxidative stress and/or the reactive oxygen species in patients with MS is partially related to the oxidation state of the lipoproteins, especially of the low density lipoproteins. This fact favors atherogenesis. Moreover, the oxidative stress produces alterations in the production of adipokines, cytokines secreted by the adipose tissues. The abnormality in the transport of lipoprotein diminishes the catabolism of the very low density lipoprotein (VLDL) and increases the catabolism of the high density lipoprotein (HDL), which creates insulin resistance. This process is associated with a lower concentration of adiponectin that in turn regulates the catabolism of VLDL and HDL; consequently increasing the flow of fatty acids from the adipose tissue to the liver and muscles. The proinflammatory cytokines, among them tumor necrosis factor alpha (TNF-alpha), are of great importance in MS regulating different processes and molecules such as PAI-1. PAI-1 is controlled by the group of transcription factors peroxisome proliferator-activated receptor (PPAR), especially by PPAR gamma and alpha ligands. In summary, MS includes multiple alterations related to insulin resistance at several levels: hepatic, muscular, adipose and vascular tissue (endothelium). The exact mechanism that underlies the relationship between MS and CVD are not sufficiently known yet; pathogenic explanations are lacking for the mechanisms relating metabolic factors to insulin resistance and the association with the development of atherosclerosis and thrombosis. MS alterations and the main aspects related to homeostasis alterations are examined in this report.
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PMID:Hemostasis alterations in metabolic syndrome (review). 1701 29

Monocytes and macrophages play a key role in the progression of atheromatous changes. The peroxisome proliferator-activated receptor gamma (PPAR gamma) can limit macroangiopathy through the control of cytokine transcription. The objectives of this study were to examine the influence of PPAR gamma and its agonist (rosiglitazone) on the TNFalpha, IL-6, IL-8 and IL-10 gene expression in monocytes of patients with diabetic macroangiopathy and to analyse obtained results in context of selected atherogenic factors ant direct indicators of endothelial lesion. TNFalpha, IL-6, IL-8, IL-10 and PPAR gamma gene expression was assessed in peripheral blood monocytes in 45 patients with type 2 diabetes before and following 22 weeks of rosiglitazone therapy (real-time PCR [Applied Biosystems]). As indicators of endothelial lesion, concentration of thrombomodulin (immunoassay [Diagnostica Stago]) and amount of circulating blood endothelial cells (immunofluorescence method with MoAb CLB-HEC19) were determined. Following rosiglitazone therapy, a statistically significant downward tendency of TNFalpha (p=0.026) and IL-8 (p=0.008) gene expression was noted. Before and following rosiglitazone treatment, PPAR gamma, IL-6 and IL-10 gene expression was undetectable in studied monocytes in vivo. In conclusion, TNFalpha and IL-8 play an important role in monocyte atherogenic activity. Rosiglitazone reduces monocyte proinflammatory readiness by influencing the expression of selected atherogenic cytokines (PPAR gamma-independent pathway).
Atherosclerosis 2007 Oct
PMID:Stimulation of the peroxisome proliferator-activated receptor gamma (PPAR gamma) and the expression of selected blood monocyte cytokine genes in diabetic macroangiopathy. 1714 Dec 46

Obesity is a low grade inflammatory state associated with premature cardiovascular morbidity and mortality. Along with traditional risk factors the measurement of endothelial function, insulin resistance, inflammation and arterial stiffness may contribute to the assessment of cardiovascular risk. We conducted a randomised placebo controlled trial to assess the effects of 12 weeks treatment with a PPAR alpha agonist (fenofibrate) and a PPAR gamma agonist (pioglitazone) on these parameters in obese glucose tolerant men. Arterial stiffness was measured using augmentation index and pulse wave velocity (PWV). E-selectin, VCAM-1 and ICAM-1 were used as markers of endothelial function. Insulin sensitivity improved with pioglitazone treatment (p=0.001) and, in keeping with this, adiponectin increased by 85.2% (p<0.001). Pro-inflammatory cytokine levels (TNFalpha, IL-6 and IL-1 beta) fell with both treatments (p<0.01 for TNFalpha and IL-1 beta, p<0.001 for IL-6). VCAM-1 and ICAM-1 were reduced with both treatments (p<0.001 for VCAM-1, p<0.05 for ICAM-1) and E-selectin improved with pioglitazone treatment (p=0.05). Both treatments resulted in a fall in augmentation index. PWV fell by 17.4% with fenofibrate treatment (p<0.001) and 16.3% with pioglitazone treatment (p<0.001). Pioglitazone and fenofibrate treatment of obese, glucose tolerant men reduces inflammation, improves markers of endothelial function and reduces arterial stiffness. These results suggest that treatment with PPAR agonists has potential to reduce the incidence of premature cardiovascular disease associated with obesity.
Atherosclerosis 2007 Oct
PMID:Fenofibrate and pioglitazone improve endothelial function and reduce arterial stiffness in obese glucose tolerant men. 1714 61

Paraoxonase 2 (PON2), a member of the paraoxonase gene family, was shown to protect macrophages against oxidative stress. Pomegranate juice (PJ), which contains potent polyphenol anti-oxidants, exhibits similar effects. We questioned possible association between PJ polyphenolics, macrophage oxidative stress, and cellular PON2 expression, in relation to the activation of specific PON2 transcription factors. Incubation of J774A.1 macrophages with PJ (0-50 microM of total polyphenols) dose-dependently increased expression (mRNA, protein) and activity and reduced macrophage oxidative status. These effects could be attributed to the PJ unique polyphenols, punicalagin and gallic acid. PJ polyphenol-induced up-regulation of PON2 was inhibited by 40% upon using the PPAR gamma inhibitor GW9662 (50 microM). Accordingly, the PPAR gamma ligand, rosiglitazone, dose-dependently stimulated macrophage PON2 expression, by up to 80%. Inhibition of AP-1 activation with SP600125, attenuated PJ-induced up-regulation of PON2 by 40%. Similarly, incubation of macrophages with PJ polyphenols in the presence of GW9662 or SP600125, significantly reduced their capacity to protect the cells against oxidative stress. We conclude that the anti-oxidative characteristics of PJ unique phenolics punicalagin and gallic acid could be related, at least in part, to their stimulatory effect on macrophage PON2 expression, a phenomenon which was shown to be associated with activation of the transcription factors PAPR gamma and AP-1.
Atherosclerosis 2007 Dec
PMID:Macrophage paraoxonase 2 (PON2) expression is up-regulated by pomegranate juice phenolic anti-oxidants via PPAR gamma and AP-1 pathway activation. 1729 3

The ATP-binding cassette transporters, ABCA1 and ABCG1, are LXR-target genes that participate in the removal of cholesterol from lipid-laden macrophages, a crucial anti-atherogenic mechanism. Statins are currently the most efficacious therapy for the treatment of hypercholesterolemia and cardiovascular disease. We and others have shown that statins decrease ABCA1 and ABCG1 expression as well as cholesterol efflux from human macrophages. However, other studies have reported that statins produce no change, or even a modest increase in these variables. In an attempt to reconcile these conflicting reports, we investigated how the effect of statins on transcription of ABCA1 and ABCG1 is modulated by cellular cholesterol status and the extent of macrophage differentiation. We showed that supplementing human macrophages with cholesterol reversed the statin-mediated down-regulation of ABC transporter expression whereas depletion of cellular cholesterol tended to accentuate the statin effect. Down-regulation of ABC transporter expression was more pronounced with increased macrophage differentiation status and already evident at statin concentrations equivalent to those present in plasma. Addition of LXR agonists, which are currently on trial as anti-atherogenic agents, reversed the effects on ABC transporter expression while PPAR alpha and PPAR gamma agonists did not. The significance of these results in light of current and future combination therapies is discussed.
Atherosclerosis 2008 Jan
PMID:The effect of statins on ABCA1 and ABCG1 expression in human macrophages is influenced by cellular cholesterol levels and extent of differentiation. 1746 10

Peroxisome proliferator-activated receptor gamma (PPAR gamma) are members of the largest nuclear hormone receptor family of transcription factors (1). PPAR gamma (PPARgamma) plays an important role in adipogenesis, control of sensitivity to insulin, inflammation and atherosclerosis but recent studies also suggest that PPARgamma is involved in cell cycle withdrawal. PPARgamma can promote cell differentiation, exert an antiproliferative action and inhibit angiogenesis (2, 3). However, there are studies showing that activation of PPARgamma promotes the development of colon cancer (4). These data are in sharp contrast with studies that attribute anticancer effects to PPARgamma in gastrointestinal malignancies. Probably, the action of PPARgamma on cell cycle and proliferation depends on the cell type and presence of other stimuli that predispose cells to cancer development. Amidated and non-amidated gastrins may play an important role in the proliferation and carcinogenesis of GI cancers. It is known that gastrin peptides activate phosphorylation of Protein Kinase B (PKB/Akt) and anti-apoptotic signalling but there is little known about the link between gastrins and PPARgamma receptors in relation to apoptosis.
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PMID:Transcriptional upregulation of gastrin in response to peroxisome proliferator-activated receptor gamma agonist triggers cell survival pathways. 1819 88

In Western culture, excess visceral fat accumulation or obesity has reached epidemic proportions, resulting in metabolic syndrome. However, more than 10 years of research has shown that adipocytes also function as endocrine cells that release various bioactive substances, so called "adipocytokines or adipokines", that play a major role in the regulation of food intake, insulin sensitivity, energy metabolism, and the vascular microenvironment. Adiponectin, an adipocytokine, is considered to improve insulin sensitivity. Recently, monocyte chemoattractant protein (MCP)-1 has been reported to be a novel adipocytokine involved in the development of obesity-associated insulin resistance and atherosclerosis. Nuclear receptors, especially peroxisome proliferator-activated receptor-alpha (PPAR alpha) and PPAR gamma are ligand-activated transcription factors that regulate the metabolism of glucose and lipids. PPAR gamma is strongly expressed in adipocytes and plays a significant role in the transcriptional activation of adipocytokines including adiponectin. PPAR alpha, another PPAR isoform, is involved in the control of lipid metabolism in the liver and skeletal muscle. PPAR alpha activation causes lipid clearance via beta-oxidation enhancement. We showed that various dietary terpenoids and other natural ingredients regulate the transcription of PPAR target genes, induces the expression and secretion of adiponectin, and inhibits those of MCP-1 in adipocytes and beta-oxidation in liver. These findings indicate that dietary factor acts as an agonist of PPARs and is a valuable medical and food component for the gradual improvement of metabolic syndrome.
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PMID:Dietary regulation of nuclear receptors in obesity-related metabolic syndrome. 1829 19

Peroxisome proliferator-activated receptor gamma (PPAR gamma) is a nuclear receptor that has been suggested to play protective roles in the pathogenesis of diseases that are characterized by chronic inflammation, such as atherosclerosis. The study of nuclear receptors, including PPAR gamma, has led to the discovery of anti-inflammatory processes that are collectively known as transrepression. In this review, we will highlight some of the mechanisms of PPAR gamma-mediated transrepression that have surfaced throughout the past decade. We will also discuss the existing evidence for an atheroprotective role of PPAR gamma as a repressor of inflammatory genes and as a key determinant of distinct monocyte-derived subpopulations that may serve an anti-inflammatory, homeostatic role in atherogenesis.
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PMID:Narrowing in on cardiovascular disease: the atheroprotective role of peroxisome proliferator-activated receptor gamma. 1830 93

The peroxisome proliferator-activated receptor (PPAR) family of nuclear hormone receptors consists of three subtypes (alpha, beta/delta, and gamma). PPAR delta is ubiquitously expressed and involved in lipid and glucose metabolism. However, the effect of PPAR delta on vascular smooth muscle cell (VSMC) proliferation and migration has not been fully elucidated yet. Here, we investigated the effect of L-165041, a selective ligand for PPAR delta, on PDGF-induced rat VSMC proliferation. Our data show that L-165041 inhibited rat VSMC proliferation in a dose dependent manner by blocking G(1) to S phase progression and repressing the phosphorylation of retinoblastoma protein (Rb). Furthermore, L-165041 inhibited PDGF-induced expression of cyclin D1 and CDK4. These effects less likely involve PPAR gamma pathway because PPAR gamma antagonist GW9662 pretreatment failed to reverse the inhibitory effect of L-165041 on rVSMC proliferation and migration. For in vivo studies, L-165041 was administered to Sprague-Dawley rats using osmotic pumps before and after the carotid balloon injury, and L-165041 decreased neointima formation after the carotid injury. In conclusion, our results suggest that PPAR delta ligand L-165041 can be a therapeutic agent to control pathologic cardiovascular conditions such as restenosis and atherosclerosis.
Atherosclerosis 2009 Feb
PMID:PPAR delta agonist L-165041 inhibits rat vascular smooth muscle cell proliferation and migration via inhibition of cell cycle. 1858 19

Exposure to lipids has a major effect on mammalian cells. Naturally, it has a profound impact on their metabolism, but it can also significantly alter their cellular and molecular phenotypes and responses. This latter is via specific signalling pathways leading to alterations in the expression of genes and gene networks. Multicellular organisms utilize a specialized group of proteins to detect and transduce lipid signals to the level of the expression of the genome. These proteins, termed nuclear hormone receptors, are lipid-activated transcription factors regulating gene expression upon binding of small fatty ligands. In this review, we discuss the role and contribution of peroxisome proliferator-activated receptor gamma (PPAR gamma) to macrophage and dendritic cell biology and also to gut epithelial cell function. We discuss how using different experimental systems and approaches the pathways activating the receptor and its target genes can be identified and complex biological processes unravelled. It appears that PPAR gamma is part of the macrophage's response to pathogenic lipoproteins and it coordinately regulates lipid uptake and efflux. Intriguingly, in another cell type of the immune system, dendritic cells, the receptor has overlapping, but distinct functions. In these cells, activation of PPAR gamma leads to altered immune phenotype characterized by increased phagocytic capacity, antigen processing and lipid antigen presenting capacity. This nuclear hormone receptor links lipid metabolism and immune cell function and these links provide unique insights into the regulatory logic of normal physiological responses and certain pathologies, such as atherosclerosis, chronic inflammatory diseases and autoimmunity.
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PMID:Nuclear receptors, transcription factors linking lipid metabolism and immunity: the case of peroxisome proliferator-activated receptor gamma. 1883 94


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