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)

Stroke is the second-leading cause of death worldwide and is a disabling disease of both older and younger adults. Stroke is also among the most highly preventable disorders because there are well-defined risk factors and preventatives. The establishment of new risk markers or factors for stroke risk assessment provides a new avenue for stroke prevention. Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an enzyme that hydrolyzes oxidized phospholipids, releasing lysophosphatidylcholine, which has proinflammatory properties thought to be involved in the development of atherosclerosis and plaque rupture. In 2005, the Lp-PLA(2) blood test was approved by the US Food and Drug Administration (FDA) for assessing the risk of ischemic stroke and coronary artery disease. In epidemiologic studies, low-density lipoprotein cholesterol and other lipid factors have not been shown to be consistent predictors of stroke risk. Lp-PLA(2) measures, on the other hand, have shown a consistent association with stroke risk, conferring about a 2-fold increase in stroke occurrence. This relation has been studied in both first and recurrent stroke and is reviewed in this article. Importantly, a recent study has now shown that Lp-PLA(2) may increase the area under the curve beyond that of traditional cardiovascular risk factors and C-reactive protein. Therefore, Lp-PLA(2) determination may provide a pivotal opportunity to appropriately classify previously misclassified persons who are actually at high risk of stroke and in need of aggressive stroke intervention.
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PMID:Lipoprotein-associated phospholipase A2 and risk of stroke. 1854 70

Accurate imaging of atherosclerosis is a growing necessity for timely treatment of the disease. Magnetic resonance imaging (MRI) is a promising technique for plaque imaging. The goal of this study was to create polymeric particles of a small size with high loading of diethylenetriaminepentaacetic acid gadolinium (III) (Gd-DTPA) and demonstrate their usefulness for MRI. A water-in-oil-in-oil double emulsion solvent evaporation technique was used to encapsulate the MRI agent in a poly(lactide-co-glycolide) (PLGA) or polylactide-poly(ethylene glycol) (PLA-PEG) particle for the purpose of concentrating the agent at an imaging site. PLGA particles with two separate average sizes of 1.83 microm and 920 nm, and PLA-PEG particles with a mean diameter of 952 nm were created. Loading of up to 30 wt % Gd-DTPA was achieved, and in vitro release occurred over 5 h. PLGA particles had highly negative zeta potentials, whereas the particles incorporating PEG had zeta potentials closer to neutral. Cytotoxicity of the particles on human umbilical vein endothelial cells (HUVEC) was shown to be minimal. The ability of the polymeric contrast agent formulation to create contrast was similar to that of Gd-DTPA alone. These results demonstrate the possible utility of the contrast agent-loaded polymeric particles for plaque detection with MRI.
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PMID:Preparation and initial characterization of biodegradable particles containing gadolinium-DTPA contrast agent for enhanced MRI. 1879 5

Increased lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) activity is associated with increased risk of cardiac events, but it is not known whether Lp-PLA(2) is a causative agent. Here we show that selective inhibition of Lp-PLA(2) with darapladib reduced development of advanced coronary atherosclerosis in diabetic and hypercholesterolemic swine. Darapladib markedly inhibited plasma and lesion Lp-PLA(2) activity and reduced lesion lysophosphatidylcholine content. Analysis of coronary gene expression showed that darapladib exerted a general anti-inflammatory action, substantially reducing the expression of 24 genes associated with macrophage and T lymphocyte functioning. Darapladib treatment resulted in a considerable decrease in plaque area and, notably, a markedly reduced necrotic core area and reduced medial destruction, resulting in fewer lesions with an unstable phenotype. These data show that selective inhibition of Lp-PLA(2) inhibits progression to advanced coronary atherosclerotic lesions and confirms a crucial role of vascular inflammation independent from hypercholesterolemia in the development of lesions implicated in the pathogenesis of myocardial infarction and stroke.
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PMID:Inhibition of lipoprotein-associated phospholipase A2 reduces complex coronary atherosclerotic plaque development. 1884 Nov 34

Lipid accumulation in arteries induces vascular inflammation and atherosclerosis, the major cause of heart attack and stroke in humans. Extreme hyperlipidemia induced in mice and rabbits enables modeling many aspects of human atherosclerosis, but microscopic examination of plaques is possible only postmortem. Here we report that feeding adult zebrafish (Danio rerio) a high-cholesterol diet (HCD) resulted in hypercholesterolemia, remarkable lipoprotein oxidation, and fatty streak formation in the arteries. Feeding an HCD supplemented with a fluorescent cholesteryl ester to optically transparent fli1:EGFP zebrafish larvae in which endothelial cells express green fluorescent protein (GFP), and using confocal microscopy enabled monitoring vascular lipid accumulation and the endothelial cell layer disorganization and thickening in a live animal. The HCD feeding also increased leakage of a fluorescent dextran from the blood vessels. Administering ezetimibe significantly diminished the HCD-induced endothelial cell layer thickening and improved its barrier function. Feeding HCD to lyz:DsRed2 larvae in which macrophages and granulocytes express DsRed resulted in the accumulation of fluorescent myeloid cells in the vascular wall. Using a fluorogenic substrate for phospholipase A(2) (PLA(2)), we observed an increased vascular PLA(2) activity in live HCD-fed larvae compared to control larvae. Furthermore, by transplanting genetically modified murine cells into HCD-fed larvae, we demonstrated that toll-like receptor-4 was required for efficient in vivo lipid uptake by macrophages. These results suggest that the novel zebrafish model is suitable for studying temporal characteristics of certain inflammatory processes of early atherogenesis and the in vivo function of vascular cells.
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PMID:Vascular lipid accumulation, lipoprotein oxidation, and macrophage lipid uptake in hypercholesterolemic zebrafish. 1926 37

Among mammalian secreted phospholipases A2 (sPLA(2)s), the group X enzyme has the most potent hydrolyzing capacity toward phosphatidylcholine, the major phospholipid of cell membrane and lipoproteins. This enzyme has recently been implicated in chronic inflammatory diseases such as atherosclerosis and asthma and may also play a role in colon tumorigenesis. We show here that group X sPLA(2) [mouse (m)GX] is one of the most highly expressed PLA(2) in the mouse colon and that recombinant mouse and human enzymes stimulate proliferation and mitogen-activated protein kinase activation of various colon cell lines, including Colon-26 cancer cells. Among various recombinant sPLA(2)s, mGX is the most potent enzyme to stimulate cell proliferation. Based on the use of sPLA(2) inhibitors, catalytic site mutants, and small interfering RNA silencing of cytosolic PLA(2)alpha and M-type sPLA(2) receptor, we demonstrate that mGX promotes cell proliferation independently of the receptor and via its intrinsic catalytic activity and production of free arachidonic acid and lysophospholipids, which are mitogenic by themselves. mGX can also elicit the production of large amounts of prostaglandin E2 and other eicosanoids from Colon-26 cells, but these lipid mediators do not play a role in mGX-induced cell proliferation because inhibitors of cyclooxygenases and lipoxygenases do not prevent sPLA(2) mitogenic effects. Together, our results indicate that group X sPLA(2) may play an important role in colon tumorigenesis by promoting cancer cell proliferation and releasing various lipid mediators involved in other key events in cancer progression.
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PMID:Group X phospholipase A2 stimulates the proliferation of colon cancer cells by producing various lipid mediators. 1960 73

Low density lipoprotein modified by secretory phospholipase A(2) (PLA-LDL) protects monocytes against oxidative stress. In this study we investigated possible direct effects of PLA-LDL on mitochondrial membrane potential and reactive oxygen species generation. Mitochondrial membrane potential in human monocytic THP-1 cells or primary human monocytes was monitored by flow cytometry using the fluorescent dye 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide or respirometry. Formation of reactive oxygen species was determined by flow cytometric measuring 2',7'-dichlorofluorescin oxidation. Cell death was assessed using Annexin V/propidium iodide staining. We observed that PLA-LDL caused mitochondrial uncoupling in monocyte/macrophage cell lines as well as in primary human monocytes. PLA-LDL-associated non-esterified fatty acids provoked uncoupling. Uncoupling attenuated reactive oxygen species formation induced by hydrogen peroxide, 2,3-dimethoxy-1,4-naphthoquinone or oxidized LDL. Knock-down of uncoupling protein UCP2 affected neither PLA-LDL-induced uncoupling, nor reactive oxygen species generation. Furthermore, we observed that the chemical uncoupler carbonyl cyanide m-chlorophenylhydrazone increased THP-1 cell survival after hydrogen peroxide treatment. Thus, PLA-LDL-induced uncoupling attenuates reactive oxygen species generation, which may contribute to increased monocyte survival in atherosclerotic plaques and support pro-atherogenic effects of LDL modified by PLA(2).
Atherosclerosis 2010 Jan
PMID:Phospholipase A2-modified low density lipoprotein induces mitochondrial uncoupling and lowers reactive oxygen species in phagocytes. 1964 53

The growing knowledge about genetic influence on cardiovascular diseases (CVD) combined with the recently generated amounts of genomic data hold promise to the identification of new markers for atherosclerotic CVD. Cardiovascular pharmacogenomics and pharmacogenetics have now the potential for leading to identification of genetic contributors and therefore to the development of predictive genetic tests that could optimize drugs efficacy and minimize toxicity. Clinical studies have shown that genetic variations within cytochromes P450 (CYPs), 3-Hydroxyl-3-Methylglutaryl Coenzyme A Reductase (HMGCR) and apolipoprotein E (APOE) genes influence individual's response to lipid lowering statins. Furthermore, development of antagonists or inhibitors of molecules such as peroxisome proliferator-activated receptors (PPARs), lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), angiotensin-converting enzyme (ACE), angiotensin receptors and tumor necrosis factor (TNF)-alpha could be another alternative to prevent atherosclerosis. In addition, novel molecules under the name of biologics including family of peptides such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), urocortin, apelin and antimicrobial peptides (AMPs) could be considered as new targets for the prevention and treatment of CVD. In this article, we will focus mainly on recent genomic advances in the development of new markers and therapeutic agents for CVD. We present an array of molecules that could have pharmacological benefit for the treatment of heart disease. We also discuss in details new strategies including biologics, which are actually the focus of companies for clinical development of therapeutic drugs. All these efforts provide optimism and attractive promise to cure CVD.
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PMID:Genomics and the prospects of existing and emerging therapeutics for cardiovascular diseases. 1975 91

Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) contributes to atherosclerotic plaque instability and subsequent sudden coronary death. Statins are associated with decreased stroke risk and may improve stability of atherosclerotic plaques. The present study investigated the effect of simvastatin on expression of Lp-PLA(2) levels in atherosclerotic plaques and on Lp-PLA(2) activity in atherosclerotic aortas. Rabbits were a fed chow (control group) or a high-cholesterol diet (atherosclerosis group) for 12 weeks. An additional group on the high-cholesterol diet received simvastatin (5 mg/kg per day) for the last 4 weeks (simvastatin group). Lp-PLA(2) activity in plasma and atherosclerotic aortas was significantly higher in the atherosclerosis group than in the control group and, consistent with this, abundant Lp-PLA(2) protein was detected in plaques in the atherosclerosis group. Simvastatin significantly reduced Lp-PLA(2) activity in plasma and aorta tissue, and reduced Lp-PLA(2) protein level in atherosclerotic plaques. Whereas there was no significant difference in total atherosclerotic lesion area between simvastatin and atherosclerosis groups, simvastatin significantly reduced macrophage content, lipid retention and the intima/media ratio but increased the content of smooth muscle cells in atherosclerotic lesions. Thus, statin treatment markedly reduced Lp-PLA(2) in both plasma and atherosclerotic plaques. This was associated with attenuation of the local inflammatory response and improved plaque stability.
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PMID:Simvastatin reduces expression and activity of lipoprotein-associated phospholipase A(2) in the aorta of hypercholesterolaemic atherosclerotic rabbits. 1976 85

Atherosclerosis is an inflammatory disease that can be assessed by circulating biomarkers. Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an enzyme produced in atherosclerotic plaque and is bound to low density lipoprotein and high-density lipoprotein cholesterol. It has a role in the pathogenesis of atherosclerosis by promoting vascular inflammation. It is emerging as a vascular-specific marker and predictor of risk for cardiovascular disease (CVD) events. Increasing evidence from many prospective epidemiologic studies have shown that elevated levels of Lp-PLA(2) are associated with future CVD events. Measurement of Lp-PLA(2) in individuals may provide clinically relevant information about their future risk of CVD events. Pharmacologic therapies and/or risk factor modification could be initiated after identification of individuals at risk for CVD. This review provides an overview of the pathophysiology, epidemiologic evidence, and clinical utility of Lp-PLA(2).
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PMID:Lipoprotein-associated phospholipase A(2): a promising vascular-specific marker for screening cardiovascular risk? 2000 43

Atherosclerosis and its clinical manifestations are widely prevalent throughout the world. Atherogenesis is highly complex and is modulated by numerous genetic and environmental risk factors. A large body of basic scientific and clinical research supports the conclusion that inflammation plays a significant role in atherogenesis along the entire continuum of its progression. Inflammation adversely impacts intravascular lipid handling and metabolism, resulting in the development of macrophage foam cells, fatty streaks and atheromatous plaque formation. Given the enormous human and economic cost of myocardial infarction, ischemic stroke, peripheral arterial disease and amputation, and premature death and disability, considerable effort is being committed to refining our ability to correctly identify patients at heightened risk for atherosclerotic vascular disease and acute cardiovascular events so that they can be treated earlier and more aggressively. Serum markers of inflammation have emerged as an important component of risk factor burden. Serum lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) potentiates intravascular inflammation and atherosclerosis. A variety of epidemiologic studies support the utility of Lp-PLA(2) measurements for estimating and further refining cardiovascular disease risk. Drug therapies to inhibit Lp-PLA(2) are in development and show considerable promise. In addition to substantially inhibiting Lp-PLA(2), darapladib reduces the progression of the necrotic core volume of coronary artery atheromatous plaque.
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PMID:Lipoprotein-associated phospholipase A2: role in atherosclerosis and utility as a cardiovascular biomarker. 2022 20


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