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Chen J, Zhang H, Li L, Zhang X, Zhao D, Wang L, Wang J, Yang P, Sun H, Liu K, Chen W, Li L, Lin F, Li Z, Chen YE, Zhang J, Pang D, Ouyang H, He Y, Fan J, Tang X. Lp-PLA 2 (Lipoprotein-Associated Phospholipase A 2) Deficiency Lowers Cholesterol Levels and Protects Against Atherosclerosis in Rabbits. Arterioscler Thromb Vasc Biol 2023; 43:e11-e28. [PMID: 36412196 DOI: 10.1161/atvbaha.122.317898] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Elevated plasma Lp-PLA2 (lipoprotein-associated phospholipase A2) activity is closely associated with an increased risk of cardiovascular events. However, whether and how Lp-PLA2 is directly involved in the pathogenesis of atherosclerosis is still unclear. To examine the hypothesis that Lp-PLA2 could be a potential preventative target of atherosclerosis, we generated Lp-PLA2 knockout rabbits and investigated the pathophysiological functions of Lp-PLA2. METHODS Lp-PLA2 knockout rabbits were generated using CRISPR/Cas9 system to assess the role of Lp-PLA2 in plasma lipids regulation and identify its underlying molecular mechanisms. Homozygous knockout rabbits along with wild-type rabbits were fed a cholesterol-rich diet for up to 14 weeks and their atherosclerotic lesions were compared. Moreover, the effects of Lp-PLA2 deficiency on the key cellular behaviors in atherosclerosis were assessed in vitro. RESULTS When rabbits were fed a standard diet, Lp-PLA2 deficiency led to a significant reduction in plasma lipids. The decreased protein levels of SREBP2 (sterol regulatory element-binding protein 2) and HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase) in livers of homozygous knockout rabbits indicated that the cholesterol biosynthetic pathway was impaired with Lp-PLA2 deficiency. In vitro experiments further demonstrated that intracellular Lp-PLA2 efficiently enhanced SREBP2-related cholesterol biosynthesis signaling independently of INSIGs (insulin-induced genes). When fed a cholesterol-rich diet, homozygous knockout rabbits exhibited consistently lower level of hypercholesterolemia, and their aortic atherosclerosis lesions were significantly reduced by 60.2% compared with those of wild-type rabbits. The lesions of homozygous knockout rabbits were characterized by reduced macrophages and the expression of inflammatory cytokines. Macrophages of homozygous knockout rabbits were insensitive to M1 polarization and showed reduced DiI-labeled lipoprotein uptake capacity compared with wild-type macrophages. Lp-PLA2 deficiency also inhibited the adhesion between monocytes and endothelial cells. CONCLUSIONS These results demonstrate that Lp-PLA2 plays a causal role in regulating blood lipid homeostasis and Lp-PLA2 deficiency protects against dietary cholesterol-induced atherosclerosis in rabbits. Lp-PLA2 could be a potential target for the prevention of atherosclerosis.
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Affiliation(s)
- Jiahuan Chen
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Huanyu Zhang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Linquan Li
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Xinwei Zhang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Dazhong Zhao
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Lingyu Wang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Jiaqi Wang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Ping Yang
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China (P.Y., H.S., K.L., W.C., Y.H.)
| | - Huan Sun
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China (P.Y., H.S., K.L., W.C., Y.H.)
| | - Kun Liu
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China (P.Y., H.S., K.L., W.C., Y.H.)
| | - Weiwei Chen
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China (P.Y., H.S., K.L., W.C., Y.H.)
| | - Lin Li
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Feng Lin
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Zhanjun Li
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.)
| | - Y Eugene Chen
- Department of Internal Medicine, Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (Y.E.C., J.Z.)
| | - Jifeng Zhang
- Department of Internal Medicine, Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (Y.E.C., J.Z.)
| | - Daxin Pang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.).,Chongqing Research Institute, Jilin University, Chongqing, China (D.P., H.O., X.T.)
| | - Hongsheng Ouyang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.).,Chongqing Research Institute, Jilin University, Chongqing, China (D.P., H.O., X.T.)
| | - Yuquan He
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China (P.Y., H.S., K.L., W.C., Y.H.)
| | - Jianglin Fan
- Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (J.F.)
| | - Xiaochun Tang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China (J.C., H.Z., Linquan Li, X.Z., D.Z., L.W., J.W., Lin Li, F.L., Z.L., D.P., H.O., X.T.).,Chongqing Research Institute, Jilin University, Chongqing, China (D.P., H.O., X.T.)
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Yeo A, Li L, Warren L, Aponte J, Fraser D, King K, Johansson K, Barnes A, MacPhee C, Davies R, Chissoe S, Tarka E, O’Donoghue ML, White HD, Wallentin L, Waterworth D. Pharmacogenetic meta-analysis of baseline risk factors, pharmacodynamic, efficacy and tolerability endpoints from two large global cardiovascular outcomes trials for darapladib. PLoS One 2017; 12:e0182115. [PMID: 28753643 PMCID: PMC5533343 DOI: 10.1371/journal.pone.0182115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 07/11/2017] [Indexed: 01/27/2023] Open
Abstract
Darapladib, a lipoprotein-associated phospholipase A2 (Lp-PLA2) inhibitor, failed to demonstrate efficacy for the primary endpoints in two large phase III cardiovascular outcomes trials, one in stable coronary heart disease patients (STABILITY) and one in acute coronary syndrome (SOLID-TIMI 52). No major safety signals were observed but tolerability issues of diarrhea and odor were common (up to 13%). We hypothesized that genetic variants associated with Lp-PLA2 activity may influence efficacy and tolerability and therefore performed a comprehensive pharmacogenetic analysis of both trials. We genotyped patients within the STABILITY and SOLID-TIMI 52 trials who provided a DNA sample and consent (n = 13,577 and 10,404 respectively, representing 86% and 82% of the trial participants) using genome-wide arrays with exome content and performed imputation using a 1000 Genomes reference panel. We investigated baseline and change from baseline in Lp-PLA2 activity, two efficacy endpoints (major coronary events and myocardial infarction) as well as tolerability parameters at genome-wide and candidate gene level using a meta-analytic approach. We replicated associations of published loci on baseline Lp-PLA2 activity (APOE, CELSR2, LPA, PLA2G7, LDLR and SCARB1) and identified three novel loci (TOMM5, FRMD5 and LPL) using the GWAS-significance threshold P≤5E-08. Review of the PLA2G7 gene (encoding Lp-PLA2) within these datasets identified V279F null allele carriers as well as three other rare exonic null alleles within various ethnic groups, however none of these variants nor any other loci associated with Lp-PLA2 activity at baseline were associated with any of the drug response endpoints. The analysis of darapladib efficacy endpoints, despite low power, identified six low frequency loci with main genotype effect (though with borderline imputation scores) and one common locus (minor allele frequency 0.24) with genotype by treatment interaction effect passing the GWAS-significance threshold. This locus conferred risk in placebo subjects, hazard ratio (HR) 1.22 with 95% confidence interval (CI) 1.11–1.33, but was protective in darapladib subjects, HR 0.79 (95% CI 0.71–0.88). No major loci for tolerability were found. Thus, genetic analysis confirmed and extended the influence of lipoprotein loci on Lp-PLA2 levels, identified some novel null alleles in the PLA2G7 gene, and only identified one potentially efficacious subgroup within these two large clinical trials.
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Affiliation(s)
- Astrid Yeo
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Stevenage, Hertfordshire, United Kingdom
| | - Li Li
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Liling Warren
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Jennifer Aponte
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Dana Fraser
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Karen King
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Kelley Johansson
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Allison Barnes
- Clinical Statistics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Colin MacPhee
- Department of Vascular Biology & Thrombosis, GlaxoSmithKline Medicines Research Centre, King of Prussia, Pennsylvania, United States of America
| | - Richard Davies
- Metabolic Pathways and Cardiovascular Therapeutic Area, GlaxoSmithKline Medicines Research Centre, King of Prussia, Pennsylvania, United States of America
| | - Stephanie Chissoe
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Research Triangle Park, North Carolina, United States of America
| | - Elizabeth Tarka
- Metabolic Pathways and Cardiovascular Therapeutic Area, GlaxoSmithKline Medicines Research Centre, King of Prussia, Pennsylvania, United States of America
| | - Michelle L. O’Donoghue
- TIMI Study Group, Cardiovascular Division, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | - Harvey D. White
- Green Lane Cardiovascular Service, Auckland City Hospital and University of Auckland, Auckland, New Zealand
| | - Lars Wallentin
- Department of Medical Sciences, Cardiology & Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden
| | - Dawn Waterworth
- Department of Genetics, GlaxoSmithKline Medicines Research Centre, Upper Merion, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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A previously unreported impact of a PLA2G7 gene polymorphism on the plasma levels of lipoprotein-associated phospholipase A2 activity and mass. Sci Rep 2016; 6:37465. [PMID: 27905470 PMCID: PMC5131362 DOI: 10.1038/srep37465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 10/27/2016] [Indexed: 12/30/2022] Open
Abstract
Lipoprotein-associated phospholipase A2 (Lp-PLA2) levels are associated with the development of atherosclerosis. We aimed to assess the genetic determinants of Lp-PLA2 activity and mass by genotyping multiple polymorphisms in PLA2G7, the gene encoding Lp-PLA2, among 1258 participants from the Chinese Multi-provincial Cohort Study-Beijing Project. The Sequenom MassARRAY system, Taqman assay and direct sequencing were adopted. For the first time, the rs13218408 polymorphism was found to be significantly associated with reduced Lp-PLA2 levels. We also confirmed the significant association of previously validated polymorphisms (rs1421378, rs1805018, rs16874954 and rs2216465), even after adjusting for traditional cardiovascular risk factors and for Bonferroni correction. Percentages of variance attributable to rs13218408 were 7.2% for activity and 13.3% for mass, and were secondary to those of rs16874954 (8.1% for activity and 16.9% for mass). A significant joint effect of rs13218408 and rs16874954 was observed on Lp-PLA2 activity (P = 0.058) and mass (P = 0.003), with their minor alleles together linking to the largest reduction in Lp-PLA2 levels (37.8% reduction in activity and 41.6% reduction in mass). Taken together, our findings show a significant association of a PLA2G7 polymorphism with Lp-PLA2 levels, which was previously unreported in any population. The functionality of this genetic variation deserves further investigations.
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Millwood IY, Bennett DA, Walters RG, Clarke R, Waterworth D, Johnson T, Chen Y, Yang L, Guo Y, Bian Z, Hacker A, Yeo A, Parish S, Hill MR, Chissoe S, Peto R, Cardon L, Collins R, Li L, Chen Z. A phenome-wide association study of a lipoprotein-associated phospholipase A2 loss-of-function variant in 90 000 Chinese adults. Int J Epidemiol 2016; 45:1588-1599. [PMID: 27301456 PMCID: PMC5100610 DOI: 10.1093/ije/dyw087] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2016] [Indexed: 12/20/2022] Open
Abstract
Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been implicated in development of atherosclerosis; however, recent randomized trials of Lp-PLA2 inhibition reported no beneficial effects on vascular diseases. In East Asians, a loss-of-function variant in the PLA2G7 gene can be used to assess the effects of genetically determined lower Lp-PLA2. Methods:PLA2G7 V279F (rs76863441) was genotyped in 91 428 individuals randomly selected from the China Kadoorie Biobank of 0.5 M participants recruited in 2004–08 from 10 regions of China, with 7 years’ follow-up. Linear regression was used to assess effects of V279F on baseline traits. Logistic regression was conducted for a range of vascular and non-vascular diseases, including 41 ICD-10 coded disease categories. Results:PLA2G7 V279F frequency was 5% overall (range 3–7% by region), and 9691 (11%) participants had at least one loss-of-function variant. V279F was not associated with baseline blood pressure, adiposity, blood glucose or lung function. V279F was not associated with major vascular events [7141 events; odds ratio (OR) = 0.98 per F variant, 95% confidence interval (CI) 0.90-1.06] or other vascular outcomes, including major coronary events (922 events; 0.96, 0.79-1.18) and stroke (5967 events; 1.00, 0.92-1.09). Individuals with V279F had lower risks of diabetes (7031 events; 0.91, 0.84-0.98) and asthma (182 events; 0.53, 0.28-0.98), but there was no association after adjustment for multiple testing. Conclusions: Lifelong lower Lp-PLA2 activity was not associated with major risks of vascular or non-vascular diseases in Chinese adults. Using functional genetic variants in large-scale prospective studies with linkage to a range of health outcomes is a valuable approach to inform drug development and repositioning.
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Affiliation(s)
- Iona Y Millwood
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Derrick A Bennett
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Robin G Walters
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Robert Clarke
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Dawn Waterworth
- GlaxoSmithKline (GSK) Medicines Research Centre, GSK, Stevenage, UK, Research Triangle Park, NC, USA and King of Prussia, PA, USA
| | - Toby Johnson
- GlaxoSmithKline (GSK) Medicines Research Centre, GSK, Stevenage, UK, Research Triangle Park, NC, USA and King of Prussia, PA, USA
| | - Yiping Chen
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Ling Yang
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Yu Guo
- Chinese Academy of Medical Sciences, Dong Cheng District, Beijing, China and
| | - Zheng Bian
- Chinese Academy of Medical Sciences, Dong Cheng District, Beijing, China and
| | - Alex Hacker
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Astrid Yeo
- GlaxoSmithKline (GSK) Medicines Research Centre, GSK, Stevenage, UK, Research Triangle Park, NC, USA and King of Prussia, PA, USA
| | - Sarah Parish
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Michael R Hill
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Stephanie Chissoe
- GlaxoSmithKline (GSK) Medicines Research Centre, GSK, Stevenage, UK, Research Triangle Park, NC, USA and King of Prussia, PA, USA
| | - Richard Peto
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Lon Cardon
- GlaxoSmithKline (GSK) Medicines Research Centre, GSK, Stevenage, UK, Research Triangle Park, NC, USA and King of Prussia, PA, USA
| | - Rory Collins
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
| | - Liming Li
- Chinese Academy of Medical Sciences, Dong Cheng District, Beijing, China and.,Department of Epidemiology & Biostatistics, Peking University Health Science Centre, Beijing, China
| | - Zhengming Chen
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, UK
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Karasawa K. Naturally Occurring Missense Mutation in Plasma PAF-AH Among the Japanese Population. Enzymes 2015; 38:117-43. [PMID: 26612650 DOI: 10.1016/bs.enz.2015.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A single nucleotide polymorphism in the plasma PAF-AH enzyme, i.e., G994T, which causes the substitution of Val at amino acid 279 with Phe (V279F), has been found in the Japanese population. This enzyme preferentially degrades oxidatively modulated or truncated phospholipids; therefore, it has been suggested that this enzyme may prevent the accumulation of proinflammatory and proatherogenic oxidized phospholipids. This hypothesis is supported by the higher prevalence of the V279F mutation in patients with asthmatic and atherosclerotic diseases, as compared with healthy controls. This mutation is rare in the Caucasian population. The plasma PAF-AH mass and enzyme activity are distributed over a wide range in the plasma and they are positively correlated with low-density lipoprotein (LDL) cholesterol. However, several clinical studies in the Caucasian population have suggested that this enzyme has the opposite role. This enzyme plays an active role in the development and progression of atherosclerosis via proinflammatory and proatherogenic lysophosphatidylcholine and oxidized fatty acids produced through the oxidation of LDL by this enzyme. Thus, plasma PAF-AH is a unique enzyme with dual roles in human inflammatory diseases. In this chapter, on the basis of recent findings we describe the association between a naturally occurring missense mutation in plasma PAF-AH and human diseases especially including atherosclerosis and asthma.
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Affiliation(s)
- Ken Karasawa
- Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo, Japan.
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Rosenson RS, Stafforini DM. Modulation of oxidative stress, inflammation, and atherosclerosis by lipoprotein-associated phospholipase A2. J Lipid Res 2012; 53:1767-82. [PMID: 22665167 DOI: 10.1194/jlr.r024190] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), also known as platelet-activating factor acetylhydrolase (PAF-AH), is a unique member of the phospholipase A(2) superfamily. This enzyme is characterized by its ability to specifically hydrolyze PAF as well as glycerophospholipids containing short, truncated, and/or oxidized fatty acyl groups at the sn-2 position of the glycerol backbone. In humans, Lp-PLA(2) circulates in active form as a complex with low- and high-density lipoproteins. Clinical studies have reported that plasma Lp-PLA(2) activity and mass are strongly associated with atherogenic lipids and vascular risk. These observations led to the hypothesis that Lp-PLA(2) activity and/or mass levels could be used as biomarkers of cardiovascular disease and that inhibition of the activity could offer an attractive therapeutic strategy. Darapladib, a compound that inhibits Lp-PLA(2) activity, is anti-atherogenic in mice and other animals, and it decreases atherosclerotic plaque expansion in humans. However, disagreement continues to exist regarding the validity of Lp-PLA(2) as an independent marker of atherosclerosis and a scientifically justified target for intervention. Circulating Lp-PLA(2) mass and activity are associated with vascular risk, but the strength of the association is reduced after adjustment for basal concentrations of the lipoprotein carriers with which the enzyme associates. Genetic studies in humans harboring an inactivating mutation at this locus indicate that loss of Lp-PLA(2) function is a risk factor for inflammatory and vascular conditions in Japanese cohorts. Consistently, overexpression of Lp-PLA(2) has anti-inflammatory and anti-atherogenic properties in animal models. This thematic review critically discusses results from laboratory and animal studies, analyzes genetic evidence, reviews clinical work demonstrating associations between Lp-PLA(2) and vascular disease, and summarizes results from animal and human clinical trials in which administration of darapladib was tested as a strategy for the management of atherosclerosis.
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Lee KK, Fortmann SP, Varady A, Fair JM, Go AS, Quertermous T, Hlatky MA, Iribarren C. Racial variation in lipoprotein-associated phospholipase A₂ in older adults. BMC Cardiovasc Disord 2011; 11:38. [PMID: 21714927 PMCID: PMC3146402 DOI: 10.1186/1471-2261-11-38] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Accepted: 06/29/2011] [Indexed: 01/27/2023] Open
Abstract
Background Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a predictor of cardiovascular events that has been shown to vary with race. The objective of this study was to examine factors associated with this racial variation. Methods We measured Lp-PLA2 mass and activity in 714 healthy older adults with no clinical coronary heart disease and not taking dyslipidemia medication. We evaluated the association between race and Lp-PLA2 mass and activity levels after adjustment for various covariates using multivariable linear regression. These covariates included age, sex, diabetes, hypertension, body mass index, lipid measurements, C-reactive protein, smoking status, physical activity, diet, income, and education level. We further examined genetic covariates that included three single nucleotide polymorphisms shown to be associated with Lp-PLA2 activity levels. Results The mean age was 66 years. Whites had the highest Lp-PLA2 mass and activity levels, followed by Hispanics and Asians, and then African-Americans; in age and sex adjusted analyses, these differences were significant for each non-White race as compared to Whites (p < 0.0001). For example, African-Americans were predicted to have a 55.0 ng/ml lower Lp-PLA2 mass and 24.7 nmol/ml-min lower activity, compared with Whites, independent of age and sex (p < 0.0001). After adjustment for all covariates, race remained significantly correlated with Lp-PLA2 mass and activity levels (p < 0.001) with African-Americans having 44.8 ng/ml lower Lp-PLA2 mass and 17.3 nmol/ml-min lower activity compared with Whites (p < 0.0001). Conclusion Biological, lifestyle, demographic, and select genetic factors do not appear to explain variations in Lp-PLA2 mass and activity levels between Whites and non-Whites, suggesting that Lp-PLA2 mass and activity levels may need to be interpreted differently for various races.
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Affiliation(s)
- Keane K Lee
- Department of Health Research and Policy, Stanford University School of Medicine, HRP Redwood Building, Stanford, CA 94305-5405, USA.
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Jang Y, Waterworth D, Lee JE, Song K, Kim S, Kim HS, Park KW, Cho HJ, Oh IY, Park JE, Lee BS, Ku HJ, Shin DJ, Lee JH, Jee SH, Han BG, Jang HY, Cho EY, Vallance P, Whittaker J, Cardon L, Mooser V. Carriage of the V279F null allele within the gene encoding Lp-PLA₂ is protective from coronary artery disease in South Korean males. PLoS One 2011; 6:e18208. [PMID: 21490708 PMCID: PMC3071750 DOI: 10.1371/journal.pone.0018208] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 02/22/2011] [Indexed: 01/28/2023] Open
Abstract
Background The Asia-specific PLA2G7 994G-T transversion leads to V279F substitution within the lipoprotein-associated phospholipase-A2 (Lp-PLA2) and to absence of enzyme activity in plasma. This variant offers a unique natural experiment to assess the role of Lp-PLA2 in the pathogenesis of coronary artery disease (CAD) in humans. Given conflicting results from mostly small studies, a large two-stage case-control study was warranted. Methodology/Principal Findings PLA2G7 V279F genotypes were initially compared in 2890 male cases diagnosed with CAD before age 60 with 3128 male controls without CAD at age 50 and above and subsequently in a second independent male dataset of 877 CAD cases and 1230 controls. In the first dataset, the prevalence of the 279F null allele was 11.5% in cases and 12.8% in controls. After adjustment for age, body mass index, diabetes, smoking, glucose and lipid levels, the OR (95% CI) for CAD for this allele was 0.80 (0.66–0.97, p = 0.02). The results were very similar in the second dataset, despite lower power, with an allele frequency of 11.2% in cases and 12.5% in controls, leading to a combined OR of 0.80 (0.69–0.92), p = 0.002. The magnitude and direction of this genetic effect were fully consistent with large epidemiological studies on plasma Lp-PLA2 activity and CAD risk. Conclusions Natural deficiency in Lp-PLA2 activity due to carriage of PLA2G7 279F allele protects from CAD in Korean men. These results provide evidence for a causal relationship between Lp-PLA2 and CAD, and support pharmacological inhibition of this enzyme as an innovative way to prevent CAD.
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Affiliation(s)
- Yangsoo Jang
- Division of Cardiology, Cardiovascular Genome Center, Yonsei University College of Medicine, Yonsei, South Korea
| | - Dawn Waterworth
- Genetics Division, Medicine Discovery and Development, Research and Development, GlaxoSmithKline, Philadelphia, Pennsylvania, United States of America and Greenford, United Kingdom
- * E-mail:
| | | | - Kijoung Song
- Genetics Division, Medicine Discovery and Development, Research and Development, GlaxoSmithKline, Philadelphia, Pennsylvania, United States of America and Greenford, United Kingdom
| | | | - Hyo-Soo Kim
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea
| | - Kyung Woo Park
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea
| | - Hyun-Jai Cho
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea
| | - Il-Young Oh
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea
| | - Jeong Euy Park
- Division of Cardiovascular Disease, Samsung Medical Center, Sung Kyun Kwan University, Seoul, South Korea
| | - Bok-Soo Lee
- Division of Cardiovascular Disease, Samsung Medical Center, Sung Kyun Kwan University, Seoul, South Korea
| | - Hyo Jeong Ku
- Division of Cardiovascular Disease, Samsung Medical Center, Sung Kyun Kwan University, Seoul, South Korea
| | - Dong-Jik Shin
- Division of Cardiology, Cardiovascular Genome Center, Yonsei University College of Medicine, Yonsei, South Korea
| | - Jong Ho Lee
- Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, South Korea
| | - Sun Ha Jee
- Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, South Korea
| | - Bok-Ghee Han
- Center for Genome Science, National Institute of Health, Seoul, South Korea
| | | | | | - Patrick Vallance
- Medicine Discovery and Development, Research and Development, GlaxoSmithKline Philadelphia, Pennsylvania, United States of America and Greenford, United Kingdom
| | - John Whittaker
- Genetics Division, Medicine Discovery and Development, Research and Development, GlaxoSmithKline, Philadelphia, Pennsylvania, United States of America and Greenford, United Kingdom
| | - Lon Cardon
- Genetics Division, Medicine Discovery and Development, Research and Development, GlaxoSmithKline, Philadelphia, Pennsylvania, United States of America and Greenford, United Kingdom
| | - Vincent Mooser
- Genetics Division, Medicine Discovery and Development, Research and Development, GlaxoSmithKline, Philadelphia, Pennsylvania, United States of America and Greenford, United Kingdom
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Stewart RAH, White HD. The Role of Lipoprotein-Associated Phospholipase A2 as a Marker and Potential Therapeutic Target in Atherosclerosis. Curr Atheroscler Rep 2011; 13:132-7. [DOI: 10.1007/s11883-010-0158-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hatoum IJ, Nelson JJ, Cook NR, Hu FB, Rimm EB. Dietary, lifestyle, and clinical predictors of lipoprotein-associated phospholipase A2 activity in individuals without coronary artery disease. Am J Clin Nutr 2010; 91:786-93. [PMID: 20107195 PMCID: PMC2824159 DOI: 10.3945/ajcn.2009.28870] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Elevated lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) may be positively associated with risk of coronary artery disease, yet little is known about potentially modifiable factors related to Lp-PLA(2). OBJECTIVE The aim of this study was to determine dietary, lifestyle, and clinical measures associated with Lp-PLA(2) activity. DESIGN We measured Lp-PLA(2) activity in 853 female participants of the Nurses' Health Study and 878 male participants of the Health Professionals Follow-Up Study who were free of cancer and cardiovascular disease. Multivariable linear regression models were used to assess the relation between potentially modifiable factors and Lp-PLA(2). RESULTS The replacement of 5% of energy from carbohydrates with energy from protein was associated with 2.2 nmol . min(-1) . mL(-1) lower levels of Lp-PLA(2) (95% CI: -3.1, -0.4) activity, and every 15-g/d increase in alcohol consumption was associated with 4.4 nmol . min(-1) . mL(-1) lower levels of Lp-PLA(2) activity (95% CI: -6.4, -2.4). Smoking (beta = 10.2; 95% CI: 4.8, 15.5), being overweight (beta = 7.5; 95% CI: 3.6, 11.3), aspirin use (beta = 6.0; 95% CI: 2.1, 10.0), hypercholesterolemia (beta = 15.0; 95% CI: 11.3, 18.8), and age (beta = 2.5; 95% CI: 1.34, 3.74) were associated with elevated Lp-PLA(2) activity, whereas postmenopausal hormone use (beta = -15.8; 95% CI: -19.4, -12.1) and cholesterol medication use (beta = -9.6; 95% CI: -18.2, -1.1) were inversely associated. CONCLUSION We found that not smoking, use of postmenopausal hormones, having a body mass index (in kg/m(2)) < or =25, increased alcohol consumption, and increased protein consumption all represent potential modifiable factors that may favorably influence Lp-PLA(2) activity.
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Affiliation(s)
- Ida J Hatoum
- Department of Nutrition and Epidemiology, Harvard School of Public Health, Boston MA, USA
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Effects of G994T in the Lp-PLA2 gene on the plasma oxidized LDL level and carotid intima-media thickness in Japanese: the Shimane study. Am J Hypertens 2009; 22:742-7. [PMID: 19373214 DOI: 10.1038/ajh.2009.70] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND A single-nucleotide polymorphism (SNP), G994T, in the lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) gene is known to have a potent influence on the activity of the enzyme. As this enzyme hydrolyzes oxidized low-density lipoprotein (oxLDL), which is an important player in atherogenesis, the present study evaluated effects of the G994T genotype on the oxLDL level as well as on intima media thickness (IMT) in vivo. METHODS Participants of a health examination (1,307 in total) were recruited from two rural communities in Shimane, Japan. Genotyping was performed by an allele-specific PCR and the TaqMan method. The oxLDL level was determined by an enzyme immunoassay. RESULTS The minor allele (994T) frequency (0.19) in the studied populations was consistent with previous reports on Japanese. The 994T allele increased the plasma oxLDL/LDL ratio in a recessive manner, whereas 994T had a codominant effect on the Lp-PLA(2) activity. A multivariate analysis revealed that age and the G994T genotype had independent effects on the oxLDL/LDL level. By contrast, the G994T genotype was not associated with IMT. All of these results were reproducible in the two independent populations studied. CONCLUSIONS G994T influenced plasma LDL oxidation. Further studies on the effect of this polymorphism in cardiovascular diseases are warranted.
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Hou L, Chen S, Yu H, Lu X, Chen J, Wang L, Huang J, Fan Z, Gu D. Associations of PLA2G7 gene polymorphisms with plasma lipoprotein-associated phospholipase A2 activity and coronary heart disease in a Chinese Han population: the Beijing atherosclerosis study. Hum Genet 2008; 125:11-20. [PMID: 19034521 DOI: 10.1007/s00439-008-0587-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Accepted: 11/06/2008] [Indexed: 12/31/2022]
Abstract
The human PLA2G7 gene encodes lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), an emerging risk factor for cardiovascular diseases. In the present study, seven single nucleotide polymorphisms (SNPs) in the PLA2G7 gene were genotyped in 827 patients with coronary heart disease (CHD), of which 512 were patients with myocardial infarction (MI), and 947 age- and gender-matched controls in a Chinese Han population. Plasma Lp-PLA(2) activity was measured in 416 randomly selected controls and 689 randomly selected CHD patients, including 423 MI patients. Lp-PLA(2) activity in CHD and MI cases was significantly higher (233.42+/-57.66 and 234.27+/-59.51 nmol ml(-1) min(-1), respectively) than in controls (211.47+/-58.61 nmol ml(-1) min(-1)). After adjusting for traditional risk factors by logistic regression, the odds ratios for CHD and MI per 1 standard deviation increment of Lp-PLA(2) activity were 1.27 (95% CI, 1.07-1.50) and 1.27 (95% CI, 1.05-1.54), respectively. Both single SNP analysis and haplotype analysis showed that the V279F and I198T polymorphisms were significantly associated with the reduced Lp-PLA(2) activity, but neither was associated with increased CHD risk. Both univariate and multivariate analyses, adjusting effects of conventional factors, indicated that the rs13210554 T allele increased the risk of MI in this Chinese Han population. In summary, an independent association of increased plasma Lp-PLA(2) activity with CHD and MI existed in this Chinese Han Population. Although V279F and I198T mutations significantly decreased the activity of Lp-PLA(2), only the promoter rs13210554 polymorphism was associated with MI. Lp-PLA(2) activity appears to influence the CHD and MI risk in Chinese Han population.
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Affiliation(s)
- Liping Hou
- Department of Evidence Based Medicine and Division of Population Genetics, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 167 Beilishi Road, 100037 Beijing, China
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Schnabel R, Dupuis J, Larson MG, Lunetta KL, Robins SJ, Zhu Y, Rong J, Yin X, Stirnadel HA, Nelson JJ, Wilson PWF, Keaney JF, Vasan RS, Benjamin EJ. Clinical and genetic factors associated with lipoprotein-associated phospholipase A2 in the Framingham Heart Study. Atherosclerosis 2008; 204:601-7. [PMID: 19135199 DOI: 10.1016/j.atherosclerosis.2008.10.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 10/15/2008] [Accepted: 10/16/2008] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To conduct an investigation of clinical and genetic correlates of lipoprotein-associated phospholipase (Lp-PLA(2)) activity and mass in a large community-based cohort. Higher circulating Lp-PLA(2) predicts cardiovascular disease risk, but sources of inter-individual variability are incompletely understood. METHODS We conducted stepwise regression of clinical correlates of Lp-PLA(2) in four Framingham Heart Study cohorts (n=8185; mean age 50+/-14 years, 53.8% women, 9.8% ethnic/racial minority cohort). We also conducted heritability and linkage analyses in Offspring and Generation 3 cohorts (n=6945). In Offspring cohort participants we performed association analyses (n=1535 unrelated) with 1943 common tagging SNPs in 233 inflammatory candidate genes. RESULTS Sixteen clinical variables explained 57% of the variability in Lp-PLA(2) activity; covariates associated with Lp-PLA(2) mass were similar but only explained 27% of the variability. Multivariable-adjusted heritability estimates for Lp-PLA(2) activity and mass were 41% and 25%, respectively. A linkage peak was observed for Lp-PLA(2) activity (chromosome 6, LOD score 2.4). None of the SNPs achieved experiment-wide statistical significance, though 12 had q values <0.50, and hence we expect at least 50% of these associations to be true positives. The strongest multivariable-association with Lp-PLA(2) activity was found for MEF2A (rs2033547; nominal p=3.20 x 10(-4)); SNP rs1051931 in PLA2G7 was nominally associated (p=1.26 x 10(-3)). The most significant association to Lp-PLA(2) mass was in VEGFC (rs10520358, p=9.14 x 10(-4)). CONCLUSIONS Cardiovascular risk factors and genetic variation contribute to variability in Lp-PLA(2) activity and mass. Our genetic association analyses need replication, which will be facilitated by web posting of our genetic association results.
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Affiliation(s)
- Renate Schnabel
- The NHLBI's Framingham Heart Study, Framingham, MA 01702-5827, USA
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Vinson A, Mahaney MC, Diego VP, Cox LA, Rogers J, VandeBerg JL, Rainwater DL. Genotype-by-diet effects on co-variation in Lp-PLA2 activity and LDL-cholesterol concentration in baboons fed an atherogenic diet. J Lipid Res 2008; 49:1295-302. [PMID: 18334716 DOI: 10.1194/jlr.m800020-jlr200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Both lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) activity, a biomarker of inflammation, and concentration of its primary associated lipoprotein, LDL, are correlated with adverse coronary outcomes. We previously reported a quantitative trait locus (QTL) corresponding to HSA2p24.3-p23.2 with pleiotropic effects on Lp-PLA(2) activity and LDL-cholesterol (LDL-C) concentration in baboons fed a basal diet. Here, our goal was to locate pleiotropic QTLs influencing both traits in the same baboons fed a high-cholesterol, high-fat (HCHF) diet, and to assess whether shared genetic effects on these traits differ between diets. We assayed Lp-PLA(2) activity and LDL-C concentration in 683 baboons fed the HCHF diet. We used a bivariate maximum likelihood-based variance components approach in whole-genome linkage screens to locate a QTL [logarithm of odds (LOD) = 3.13, genome-wide P = 0.019] corresponding to HSA19q12-q13.2 with pleiotropic effects on Lp-PLA(2) activity and LDL-C levels in the HCHF diet. We additionally found significant evidence of genetic variance in response to diet for Lp-PLA(2) activity (P = 0.0017) and for LDL-C concentration (P = 0.00001), revealing a contribution of genotype-by-diet interaction to covariation in these two traits. We conclude that the pleiotropic QTLs detected at 2p24.3-p23.2 and 19q12-q13.2 on the basal and HCHF diets, respectively, exert diet-specific effects on covariation in Lp-PLA(2) activity and LDL-C concentration.
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Affiliation(s)
- Amanda Vinson
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, TX, USA.
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