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)

Cardiovascular disease is the leading cause of death in most industrialized countries. However, the diagnosis and management of coronary heart disease is far from optimal. Lipoprotein-associated phospholipase A2 (Lp-PLA2), also known as platelet-activating factor acetylhydrolase, is an enzyme that hydrolyses oxidized phospholipids and is primarily associated with low-density lipoprotein. Discussed in this review is the accumulating evidence supporting the view that Lp-PLA2 is a potential biomarker of coronary heart disease and plays and an important proinflammatory role in the progression of atherosclerosis. A new ELISA method for the quantitative measurement of Lp-PLA2 mass in human plasma developed by diaDexus, Inc. is presented. Furthermore, potential clinical applications of Lp-PLA2 mass measurements are proposed.
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PMID:Lp-PLA2: an emerging biomarker of coronary heart disease. 1196 98

Angiotensin II (Ang II) is a multifunctional hormone that influences the function of cardiovascular cells through a complex series of intracellular signaling events initiated by the interaction of Ang II with AT1 and AT2 receptors. AT1 receptor activation leads to cell growth, vascular contraction, inflammatory responses and salt and water retention, whereas AT2 receptors induce apoptosis, vasodilation and natriuresis. These effects are mediated via complex, interacting signaling pathways involving stimulation of PLC and Ca2+ mobilization; activation of PLD, PLA2, PKC, MAP kinases and NAD(P)H oxidase, and stimulation of gene transcription. In addition, Ang II activates many intracellular tyrosine kinases that play a role in growth signaling and inflammation, such as Src, Pyk2, p130Cas, FAK and JAK/STAT. These events may be direct or indirect via transactivation of tyrosine kinase receptors, including PDGFR, EGFR and IGFR. Ang II induces a multitude of actions in various tissues, and the signaling events following occupancy and activation of Ang receptors are tightly controlled and extremely complex. Alterations of these highly regulated signaling pathways may be pivotal in structural and functional abnormalities that underlie pathological processes in cardiovascular diseases such as cardiac hypertrophy, hypertension and atherosclerosis.
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PMID:Recent advances in angiotensin II signaling. 1221 72

Platelet membrane glycoprotein IIb/IIIa plays an important role in platelet aggregation. A polymorphism of the gene encoding the IIIa subunit, with the two allele forms PLA1 and PLA2, has been identified. Some, but not all, studies suggest that the PLA2 allele confers an increased risk of suffering a myocardial infarction. Conversely, a recent study suggests that the PLA1 allele may contribute to early atherosclerosis and more rapid progression of stable coronary artery disease. To test whether these associations could be reproduced in a well-characterized sample of survivors of premature myocardial infarction, we examined 369 patients admitted to coronary care units in the Stockholm area who suffered a first myocardial infarction before the age of 60 years. There were no significant differences in extent of coronary artery disease according to PLA genotype group (based on quantitative coronary angiography). In addition, the frequencies of PLA1 and PLA2 alleles did not differ from those of 388 well-matched control subjects without coronary artery disease. These results suggest that the PLA1/PLA2 polymorphism of the platelet glycoprotein IIIa gene does not substantially contribute to the development of coronary atherosclerosis or the genetic susceptibility to premature myocardial infarction.
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PMID:No evidence that the PLA1/PLA2 polymorphism of platelet glycoprotein IIIa is implicated in angiographically characterized coronary atherosclerosis and premature myocardial infarction. 1461 55

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a member of the phospholipase A2 superfamily, a family of enzymes that hydrolyze phospholipids. Circulating Lp-PLA2 is a marker of inflammation that plays a critical role in atherogenesis; its inhibition may have antiatherogenic effects. Epidemiological data have consistently demonstrated the association of increased levels of Lp-PLA2 with increased risk of coronary heart disease (CHD). In general, studies from the West of Scotland Coronary Prevention Study, Monitoring Trends and Determinants in Cardiovascular Diseases, and Rotterdam cohorts have shown that the association of Lp-PLA2 with CHD is not attenuated upon multivariate analysis with traditional risk factors and other inflammatory markers. In addition, in the Atherosclerosis Risk in Communities cohort, Lp-PLA2 was particularly useful in identifying CHD risk among patients with a baseline low-density lipoprotein less than 130 mg/dl. Studies in subjects with coronary artery disease have also shown associations between Lp-PLA2 and cardiovascular risk. Polymorphisms of the Lp-PLA2 gene have been reported, with varying significance, in Japanese and Caucasian populations. Overall, epidemiological studies suggest that measurement of Lp-PLA2 in plasma may be useful in identifying individuals at high risk for cardiac events.
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PMID:Clinical review: Lipoprotein-associated phospholipase A2, a novel inflammatory biomarker and independent risk predictor for cardiovascular disease. 1571 11

The development of atherosclerotic vascular disease is invariably linked to the formation of bioactive lipid mediators and accompanying vascular inflammation. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme that is produced by inflammatory cells, co-travels with circulating low-density lipoprotein (LDL), and hydrolyzes oxidized phospholipids in LDL. Its biological role has been controversial with initial reports purporting atheroprotective effects of Lp-PLA2 thought to be a consequence of degrading platelet-activating factor and removing polar phospholipids in modified LDL. Recent studies, however, focused on pro-inflammatory role of Lp-PLA2 mediated by products of the Lp-PLA2 reaction (lysophosphatidylcholine and oxidized nonesterified fatty acids). These bioactive lipid mediators, which are generated in lesion-prone vasculature and to a lesser extent in the circulation (eg, in electronegative LDL), are known to elicit several inflammatory responses. The proinflammatory action of Lp-PLA2 is also supported by a number of epidemiology studies suggesting that the circulating level of the enzyme is an independent predictor of cardiovascular events, despite some attenuation of the effect by inclusion of LDL, the primary carrier of Lp-PLA2, in the analysis. These observations provide a rationale to explore whether inhibiting Lp-PLA2 activity and consequent interference with the formation of bioactive lipid mediators will abrogate inflammation associated with atherosclerosis, produce favorable changes in intermediate cardiovascular end points (eg, biomarkers, imaging, and endothelial function), and ultimately reduce cardiovascular events in high-risk patients.
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PMID:Role of lipoprotein-associated phospholipase A2 in atherosclerosis: biology, epidemiology, and possible therapeutic target. 1573 92

Lipoprotein associated phospholipase A2 (Lp-PLA2), a biomarker of oxidation and inflammation, has been associated with increased coronary heart disease (CHD) risk. To date, data examining the effect of HMG CoA reductase inhibitors on Lp-PLA2 are few. We evaluated the effect of pravastatin 40 mg daily versus placebo on Lp-PLA2 levels among 481 subjects free of cardiovascular disease (pravastatin N=246 and placebo N=235) who participated in the Pravastatin Inflammation/CRP Study (PRINCE). After 12 weeks, Lp-PLA2 levels decreased by 22.1% among pravastatin treated participants and by 7.8% among those randomized to placebo (p<0.001). These results were similar in all subgroups evaluated according to age, blood pressure, lipid parameters, diabetic status, smoking status, aspirin use, body mass index and gender. There were correlations between change in Lp-PLA2 levels and baseline Lp-PLA2 levels (r=-0.63, p<0.001), total cholesterol change (r=-0.26, p<0.001), LDL-C change (r=-0.32, p<0.001) and C-reactive protein (CRP) change (r=-0.13, p=0.05). Multivariate linear regression models that assessed the relationship between the log difference in Lp-PLA2 at 12 weeks and treatment revealed a beta-coefficient of 0.15 for the treatment variable (p<0.01). However, adjustment for change in LDL-C substantially attenuated the beta-coefficient associated with treatment to 0.07 (P<0.005) and after additional control for other potential confounders, the effect of treatment was no longer significant. Thus, Lp-PLA2 levels were significantly reduced at 12 weeks by pravastatin, an effect that was significantly related to LDL cholesterol reduction accounting for about 6% of the variability in this response. Moreover, pravastatin induced reduction in Lp-PLA2 was no longer significant after taking the latter into account.
Atherosclerosis 2005 Sep
PMID:The effect of statin therapy on lipoprotein associated phospholipase A2 levels. 1598 58

Lipoprotein-associated phospholipase A2 (Lp-PLA2) generates pro-inflammatory molecules from oxidized LDL. We examined the association between Lp-PLA2 plasma concentrations and risk of stable coronary artery disease (CAD) in a large case-control study and further assessed the relationship between Lp-PLA2 and various lipid, inflammatory and hemostatic parameters. Lp-PLA2 concentrations were measured in 312 patients with CAD and in 479 age- and gender-matched blood donors. Various sensitive inflammatory and hemostatic markers and a complete lipoprotein profile were obtained. Lp-PLA2 concentrations were significantly higher in cases than in controls (296.1 ng/mL versus 266.0 ng/mL, p<0.0001). In multivariable logistic regression, the age- and gender-adjusted OR for the presence of CAD was 1.61 (95% CI, 1.07-2.44) if the top quartile of the Lp-PLA2 distribution was compared to the bottom quartile. Adjustment for traditional cardiovascular risk factors and statin use resulted in an OR of 2.04 (95% CI, 1.19-3.48). After additional controlling for vWF, the OR was slightly attenuated but still remained statistically significant (OR 1.91; 95% CI, 1.12-3.28). Thus, elevated Lp-PLA2 concentrations were associated with the presence of stable CAD, independent of various biochemical markers. Our results support the hypothesis that Lp-PLA2 may be a novel, independent risk marker for CAD.
Atherosclerosis 2005 Sep
PMID:Association between Lp-PLA2 and coronary artery disease: focus on its relationship with lipoproteins and markers of inflammation and hemostasis. 1611 90

Lipoprotein associated phospholipase A2 (Lp-PLA2) modulates low-density lipoprotein (LDL) oxidation by hydrolysing oxidised phospholipids present on particle surfaces. We investigated whether Lp-PLA2 activity and PLA2G7 A379V genotype were related to mediators of atherosclerosis in a diabetic study. Plasma Lp-PLA2 activity (taken in men only) and A379V genotype were investigated with regards to metabolic syndrome (MS), UKPDS risk score, and oxidised LDL (oxLDL/LDL), in a cohort of Caucasian men and women (n=783, age 62.5+/-13.7 years). After adjustment for type of diabetes, CHD status, and statin use, those individuals with features defining the MS (WHO guidelines) had higher Lp-PLA2 activity (35.6+/-11.9 nmol/min/ml) compared to those without (33.0+/-10.8 nmol/min/ml) (p=0.02). Quartiles of UKPDS coronary heart disease (CHD) risk score were also positively associated with Lp-PLA2 activity (p=0.006, p=0.004 linear trend). Those men in the highest quartile of oxLDL/LDL level had the lowest Lp-PLA2 activity (31.3+/-10.5 nmol/min/ml) when compared to the middle two (32.3+/-9.8 and 35.9+/-10.9 nmol/min/ml, respectively) and lowest quartile (35.6 +/-12.5 nmol/min/ml; p=0.03, p=0.004 linear trend). There was no significant association between A379V genotype and Lp-PLA2 enzyme activity (p=0.34) or oxLDL/LDL (p=0.32). Lp-PLA2 activity is an independent predictor of CHD risk and MS in a sample of subjects with diabetes mellitus. The association of Lp-PLA2 activity with oxLDL/LDL suggests that Lp-PLA2 may be a modulating factor in the process of atherosclerosis.
Atherosclerosis 2006 Nov
PMID:Lp-PLA2 activity and PLA2G7 A379V genotype in patients with diabetes mellitus. 1643 75

Despite substantial progress in preventing adverse cardiovascular events with current therapeutic strategies, there remains an extensive residual risk of clinical events, particularly in high-risk patients. Because of the evidence implicating inflammation in the pathogenesis of atherosclerosis, identifying and targeting inflammatory pathways could help further reduce cardiovascular risk. There has been controversy regarding the role of lipoprotein-associated phospholipase A2 (Lp-PLA2) in atherosclerosis, partly because of the lack of simple animal models with a human-like pattern of Lp-PLA2 lipoprotein distribution. However, accumulating evidence from pathology, biology and epidemiology studies favors a pro-atherogenic rather than an atheroprotective role for the enzyme. In particular, Lp-PLA2 might play an important role in plaque vulnerability. As a result, additional studies are warranted to determine whether Lp-PLA2 inhibition improves plaque stability and ultimately clinical outcomes for high-risk patients.
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PMID:Role of lipoprotein-associated phospholipase A2 in atherosclerosis and its potential as a therapeutic target. 1649 53

Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) has been shown to play a crucial role in atherosclerosis, and has been proposed as a promising target for drug discovery. Here, we cloned the Lp-PLA(2) gene from differentiated THP-1 cells, and inserted a carboxy-terminal His(6)-tagged version of the gene into the pPIC9 Pichia expression vector. The Lp-PLA(2) fusion protein was successfully expressed in Pichia pastoris expression system and could be rapidly purified to apparent homogeneity using a single-step purification method. The activity of our recombinant Lp-PLA(2) was strong when [3H] PAF was used as a substrate, and the Lp-PLA(2) inhibitor SB435495 exhibited an inhibitory curve against the recombinant Lp-PLA2 (IC50 = 15.93 +/- 1 microM). This novel recombinant Lp-PLA(2) could prove useful as a screening model for Lp-PLA(2) inhibitors, and may facilitate further investigation of this protein in atherosclerosis.
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PMID:Cloning, expression, and purification of lipoprotein-associated phospholipase A(2) in Pichia pastoris. 1669 Oct 4


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